CN1027147C - Ink jet recording method and apparatus using thermal energy - Google Patents

Abstract

A recording method in which ink is ejected by a thermal energy generating element of a recording head in response to thermal energy generated by a drive signal applied thereto, the method comprising the steps of varying a waveform of the drive signal in accordance with a temperature of the recording head; and selecting a fixed waveform of the drive signal when the temperature of the recording head exceeds a predetermined level.

Description

Ink jet recording method and apparatus using thermal energy

The present invention relates to a kind of ink jet recording method, equipment and record head thereof that utilizes heat energy.

In the ink jet recording device of routine, need to adopt various control methods to stablize ink jet direction (degree of accuracy of measuring point) and emitted dose (Vd(Pl/dot)) so that the density of image that reduces on recording picture and the analog changes or heterogeneity.

These control modes comprise control prepared Chinese ink temperature (temperature control) ink viscosity relevant with the ink jet amount with control.Form in prepared Chinese ink by heat energy in bubble and the recording equipment this, factors such as bubble formation condition are controlled, can stablize emitted dose by air bubble expansion injection prepared Chinese ink.With regard to being used for the temperature controlled ad hoc structure of prepared Chinese ink, it can comprise a heater that is used to heat the record head that contains prepared Chinese ink (be exclusively used in this purpose or be generally used for the jet heater of this purpose) and a temperature sensor that is used to detect the temperature relevant with this record head.To feed back to heater by the detected temperature of temperature sensor.Scheme also can not carried out this temperature feedback, and just be heated record head with heater simply as a comparison.

Heater and temperature sensor can be installed on a certain element that constitutes record head, also can be installed in the outside of record head.

The method that is used to control the another kind of method of emitted dose or similar parameters or can be used in combination with said method is, the pulse width (thermal pulse) that will be used for producing the individual pulse of heat energy is supplied with the electrothermal transducer (jet heater) that is used for producing in the injection of the above-mentioned type heat energy, thereby control quantity of heat production, and then stable emitted dose.

Various control modes can be divided into following four classes:

(1) near All Time (outside /), carry out the control of record head temperature with the temperature feedback system,

(2) when needed (outside/near) carry out the control of record head temperature with the temperature feedback system,

(3) carry out high temperature record head control (being higher than environment temperature) with the temperature feedback system,

(4) pulse width modulation of single thermal pulse.

For the first kind, owing to all the time the temperature of record head is being controlled, thereby can be owing to the evaporation of quickening moisture content in the prepared Chinese ink.Therefore, increasing or solidifying and to cause departing from even can causing spray losing efficacy of injection direction at record head jet exit place prepared Chinese ink.And, because the dyestuff composition in the prepared Chinese ink is higher relatively, may cause variable density or heterogeneity.This will greatly reduce image quality.Be that the change of the material of the change of recording head structure and formation record head is bad will to cause the reliability of record head and service life to be reduced owing to heater heats another influence that produces continuously.In general, this control is subjected to variation of ambient temperature and self temperature raises because printing caused influence easily.More precisely, the variation of this emitted dose will cause variable density or heterogeneity.

In second type systematic, be just to carry out the temperature control operation when needed, thereby it is the modified of the first kind.Yet, because this temperature control is carried out, need in the quite short time, reach predetermined temperature after print command produces, thereby need bigger heat energy (quantity of heat production of heater (W)).This will cause, and temperature fluctuation increases when temperature is controlled, thereby makes that can not carry out correct temperature controls.If this thing happens, emitted dose will change owing to temperature fluctuation, and then density of image be changed or the generation heterogeneity.If attempt to carry out suitably and effectively temperature control, just need to reduce energy and supply with.Reach the required time increase of target temperature if can make so again, and increase the stand-by period before beginning to print thus.

For the 3rd class control system, make target temperature be higher than environment temperature, so can avoid because variation of ambient temperature or because the influence of temperature variation that self temperature rising that printing causes is produced.Thus, can also be reduced in low-power and print during the variation of ink ejection amount.But when the high power printing, for example when uninterrupted black was printed, because it is quite high to print the temperature that is produced, the influence that this temperature rises can't be got rid of.

With regard to temperature control, also can control the temperature of record head outside.This will help to reduce the influence of environment temperature.Yet this is not satisfactory to response that himself temperature rises, thereby its influence of risen by self temperature.

If the temperature around the record head is controlled, for example on the aluminium sheet of the heater plates that has jet heater as substrate supporting, heater or temperature sensor are set, then above-mentioned response will improve, and can overcome the temperature rising that produces because of printing effectively.Yet, because the thermal capacity of aluminum base plate is quite big, so can cause temperature fluctuation.Because the temperature fluctuation meeting changes emitted dose.

In the 4th class control system, utilize individual pulse to come modulating pulse width.Yet, can regulate the emitted dose controlled range that emitted dose changes owing to what the bubble variation of temperature in the system that forms ink-jet determined, with owing to be difficult to obtain the linear relationship of emitted dose and corresponding pulse width increment, so be necessary further this system to be improved, to improve its repeatability, thereby can finish accurate emitted dose control from improving the angle of image quality.

Except emitted dose changes this problem, also there is the problem that raises and produced because of record head self temperature, the i.e. variation of the nozzle parameter that in print procedure, is produced and because of the variation of the control parameter that variation produced in the recording head structure because of the prepared Chinese ink variations in temperature.The change that this may cause injection direction makes and sprays failure, and can reduce the frequency of filling once more.If these situations will reduce image quality greatly.

Because black head cartridge produces in enormous quantities, in the zone of size that is formed on heating plate resistance on the silicone chip, membrane structure, jet exit by semiconductor production process or like, it is inevitable that some variations take place.So these variations may be present in the emitted dose of each ink jet mouth in the record head, also may occur in the parameter of each record head.

The variation of record head nozzle parameter can cause the variation of control parameter in the print procedure, and the variation of prepared Chinese ink initial injection quantity.In each record head nozzle parameter, image is formed the particularly importantly variation of each record head ink ejection amount and the variation of control parameter.

Another problem is to produce heterogeneity and the similar problem that non-homogeneous Temperature Distribution causes because of number of nozzle.

More precisely, in fact be not that all nozzles all obtain effective use in printing.For example, in printing, only use wherein half nozzle probably.In other words, print area is not the integral multiple of record head print span, therefore, is printing on the bottom line, and only some nozzle is used for printing.

When the operation ink jet recording device make its response by external equipment for example reading device provide control signal the time, need on the basis of common printing, change the number of record head top nozzle.For example, in continuous printing type ink jet recording device, need appropriate design, so that can be with paper feed stable accuracy (record head width) in the standard feeding, therefore, if paper feed speed changes because of reducing to print, then can influence its precision (jamming pattern) owing to connect the effect of colour band.In view of this, to print be more effective to the two pass that carries out twice printing during a paper supply.To this situation, when printing operation, need change the number of nozzle.

If the printing nozzle number on the record head changes, then can produce the non-uniform Distribution of temperature owing to the starting jet heater.This non-homogeneous Temperature Distribution causes the change of emitted dose.In the driving of record head ink jet recording device by temperature sensor control, unless consider the distribution of temperature during control, otherwise will produce print density heterogeneous.

In modern ink jet recording device, the gap between record head and recording materials is that material or the register system (single channel or binary channels) according to recording materials (common paper, art paper, OHP paper etc.) changes.This can cause the reduction of prepared Chinese ink deposition position precision.

This problem directly has influence on the image quality of printing.Particularly, when using four look prepared Chinese ink materials such as navy blue, magneta colour, yellow and black prepared Chinese ink material to carry out panchromatic printing, if nozzle parameter is different with the canonical parameter of record head, then the variation of nozzle parameter will cause the change of emitted dose.Consequently, upset color balance so that reduced the reproducing characteristic (aberration increase) of color and color.When adopting mass colour, redness, blueness or green to carry out monochrome record, owing to ink-jet failure in whole image can make variable density for example the generation of colour band become more obvious.In addition, because injection direction departs from, will the repeatability and the character code quality of fine rule be descended.

The advantage of ink jet recording device is to carry out record in the wide region of recording medium.For example, quite Chang Yong medium comprises common record-paper, envelope class ground paper, on look the cellophane paper or the analog of projecting apparatus (OHP) usefulness.In these recording materials or medium, OHP paper needs highdensity printing, with box lunch it by on when looking the projecting apparatus projection, can clearly provide the character code and the image of printing.

Therefore need control the variation of emitted dose, and particularly to OHP paper, the printing of the high density of image that expect.

A main purpose of the present invention just provides a kind of ink jet recording method and equipment, the stability of its ink ejection amount with because of variation of ambient temperature (printing variations in temperature that cause and that self temperature rises and causes) irrelevant.

Another object of the present invention provides a kind of self temperature the rise ink jet recording method and equipment of the influence that produced of reducing.

Further purpose of the present invention provides a kind of ink jet recording device, this equipment uses with removably and is installed in record head on the equipment, for record head, the variation of the initial ink ejection amount that is caused by production process can be proofreaied and correct so that suitable ink ejection amount to be provided.

Further purpose of the present invention is to make to make because of thereby suitable more or less emitted dose can increase record head output to become possibility with the record head that reduces the record head cost.

Another object of the present invention provides a kind of ink jet recording method and equipment, and wherein the ink ejection amount that produces because of the temperature non-uniform Distribution relevant with each jet exit changes and can be reduced.

Further purpose of the present invention provides a kind of ink jet recording method and equipment, has both made because of environment temperature and self temperature rise to cause the variations in temperature of record head, and its jet speed and prepared Chinese ink recharge frequency and also can correctly be controlled.

Further purpose of the present invention provides a kind of ink jet recording method and equipment, and the packing density that can increase it when at the enterprising line item of OHP paper is to provide suitable emitted dose.

Further purpose of the present invention provide a kind of China ink amount of ejection can be in relative broad range the ink jet recording method and the equipment of smooth change.

One aspect of the present invention provides a kind of recording method, this method is to come ink-jet by the heat energy that the driving signal that the heat generating element response of record head is imported produces, the step that comprises is: drive the waveform of signal according to the temperature change of record head, select a definite drive signal waveform when the temperature of record head surpasses predetermined value.

Another aspect of the present invention provides a kind of ink jet recording device that sprays prepared Chinese ink, comprising: one has heat generating element so that spray the record head of prepared Chinese ink by the heat energy that drives the signal generation by this heat generating element response; The temperature-detecting device that is used for a detection record temperature; Be used for changing the driving chromacoder of drive signal waveform according to the output signal of described checkout gear; Be used for that output signal when described checkout gear reaches or block described conversion equipment and the control device that drives the predetermined waveform of signal is provided when being higher than predetermined temperature value.

Another aspect of the present invention provides and a kind ofly can be installed in record head on the recording equipment main body, can heat operation with removably, comprise: be used to receive comprise and have the device that first of different in width drives the pumping signal of signal, be used to store the information-storing device that when information is imposed on main body, changes the first driving deration of signal information with recording equipment.

Another aspect of the present invention provides a kind of recording equipment, it comprises: have the record head that pumping signal that first of variable-width drives signal drives and be used for reading the information of determining width and changing from the information-storing device of described record head supplying with the driving chromacoder that first of record head drives the deration of signal by comprising.

Another aspect of the present invention provides a kind of ink jet recording device that ejects prepared Chinese ink, and it comprises: the ink jet outlet; Export corresponding jet heater with described ink jet; Temp sensor device; Ink jet print head with described prepared Chinese ink exit wound of bullet, described jet heater and described temp sensor device; Be used under the different driving condition, driving the drive unit of described record head according to the output signal of described temp sensor device; Be used for according to the conversion equipment that changes its drive condition at the employed jet exit of record operation.

Another aspect of the present invention provides a kind of ink jet recording device that sprays prepared Chinese ink, and it comprises: a plurality of prepared Chinese ink exits wound of bullet; Export corresponding jet heater with described ink jet; A plurality of temperature control heaters; With a plurality of temperature sensors; An ink jet record head that includes described jet exit, jet heater, the described temperature sensor of Temperature controlled heater; Be used under the different driving condition, driving the drive unit of described record head according to the output signal of described temperature sensor; With the conversion equipment that changes its drive condition according to employed described jet exit in the record operation.

Another aspect of the present invention provides a kind of jetting recorder that ejects prepared Chinese ink, and it comprises: be used for producing bubble to eject the ink jet print head of prepared Chinese ink by the expansion of bubble with the heat energy that heat generating element response driving signal produces at prepared Chinese ink; Be used to control the control device of air bubble expansion speed, wherein drive signal and comprise that pulse width is P₁, interval width is P₂First pulse and pulse width be P₃Second pulse, its pass is P₁≤ P₂＜P₃, and the control of its speed of expansion is to realize by the waveform that changes first pulse.

Another aspect of the present invention provides a kind of spraying equipment that sprays prepared Chinese ink, it comprises: one has and is used for the record head of produce power to help the energy generating device that sprays prepared Chinese ink, is used to provide drive the head driver of signal to described energy generating device; Be used to detect the temperature-detecting device of the temperature relevant with described record head; Be used for changing the conversion equipment of drive signal waveform according to the output signal of described checkout gear; Be used for when employed recording materials are OHP paper, waveform being defined as the driving control device of a certain predetermined waveform.

Another aspect of the present invention provides the ink jet recording device that a kind of use has the record head of electrothermal transducer, for different recording materials, it can be operated under different logging modes, and comprises: can operate under first logging mode and second logging mode of tape deck can operate under to(for) the recording materials of routine for each recording materials with transparent part; Be used for changing the conversion equipment of the driving signal that adds to electrothermal transducer according to the temperature detection result relevant with record head; Wherein, the variable range that drives signal differs from one another to first logging mode and second logging mode, includes the maximum drive signal in the second logging mode scope in the scope of first logging mode.

Another aspect of the present invention provide a kind of comprise can by the heat energy that produces according to the driving signal that is added on the heater in prepared Chinese ink, form bubble and by air bubble expansion with the ink jet recording device of ink jet to the recording materials, comprise the drive unit that is used for when first ink droplet jet, providing a plurality of driving signals to described heater, described a plurality of driving signal comprises and is used to improve near the prepared Chinese ink temperature the heater but do not produce that first of bubble drives signal and after first drives signal and first drive and spacedly between signal be used to spray second of prepared Chinese ink and drive signal, and drives the prepared Chinese ink that heat energy that signal produces will pass to close heater in this interim by first; Be used for driving the conversion equipment that the deration of signal changes ink ejection amount by changing first, wherein, even when first width that drives signal during near its maximum, described interval is not shorter than the width of the first driving signal yet.

Another aspect of the present invention provides a kind of ink jet recording method, this method is to form bubble by the heat energy that produces according to the driving signal that imposes on heater in prepared Chinese ink, by air bubble expansion China ink is ejected on the recording materials, and provide a plurality of driving signals to heater when each ink droplet jet, the step that this method comprises is: provide first to drive signal to increase near the prepared Chinese ink temperature the heater effectively; After first drives the signal effect, provide an off period, answer described off period long enough to guarantee driving signal is given close heater by the thermal energy transfer of heater generation prepared Chinese ink according to first; Provide second to drive signal in prepared Chinese ink, to produce bubble effectively and to eject prepared Chinese ink; With change first width that drives signal to regulate ink ejection amount, wherein, even, still be not shorter than the width of the first driving signal described off period when first width that drives signal during near its maximum.

Above-mentioned purpose of the present invention and other purpose, characteristic and advantage, the description by the following most preferred embodiment of the present invention that provides in conjunction with the accompanying drawings will become more apparent.

Fig. 1 represents according to one embodiment of the present of invention, is used for the impulse waveform of each minute pulse in the pulse width modulation driving method.

Fig. 2 is the profile and the front view of the record head that uses in this embodiment of the invention.

Fig. 3 and Fig. 4 represent in the one embodiment of the invention curve map that concerns between relation and ink ejection amount and record head temperature between ink ejection amount and pulse width respectively.

The principle of the branch pulse width modulated driving method in Fig. 5,6, the 7 expression one embodiment of the invention.

Fig. 8 illustrates the control method of emitted dose in the one embodiment of the invention.

Fig. 9 represents the impulse waveform in the chart inserted of one embodiment of the invention.

Figure 10 represents employed record head temperature of one embodiment of the invention and corresponding preheat pulse modulation control form.

Figure 11 is the flow chart of the pulse width modulated sequential operation in the one embodiment of the invention.

Figure 12 is the top view of the employed heater plates of one embodiment of the invention.

Figure 13 is the perspective view of the color printer relevant with one embodiment of the invention.

Figure 14 is illustrated in the time-write interval of each color in the panchromatic printing.

Figure 15 is the part section view of describing the block diagram of the printer control system structure relevant with one embodiment of the invention and being used for the record head print cartridge of this equipment with Figure 16.

Figure 17 is a conventional equipment and according to the tone rendering linearity curve figure of the equipment of one embodiment of the present of invention.

Figure 18 and Figure 19 be preheat pulse width in the equipment of expression according to one embodiment of the invention structure with self temperature of record head and raise with printing state parameter between the curve map of relation, and the curve map that concerns between expression printing interval and the rising of self temperature.

Figure 20 and be used to relevant with another embodiment of the present invention of 21 expressions preheat the modulation of pulse and control the curve map that concerns between form and expression time-write interval and the rising of record head self temperature.

Figure 22 represents the modulation control form that be used for preheat pulse relevant with another embodiment of the present invention.

Figure 23,24, the 25th, the main control operational flowchart of the ink jet recording device that constitutes according to one embodiment of the present of invention.

Figure 26 A, 26B, 26C are the temperature control that is used for initial 20 degree, the temperature control of 20 degree and the temperature controlled operational flowchart of 25 degree.

Figure 27 represents step S₄Initial mounting board trace routine in operational flowchart.

Figure 28 is expression step S₅Detailed flow chart of recording head information fetch program.

Figure 29 is illustrated in form point TA1 and the main heating pulse width P that is obtained by a TA1₃Between relation.

Figure 30 represents form point TA3 and preheats pulse width P₁Between relation.

Figure 31 A, 31B, 31C represent record head temperature T H and preheat pulse width P₁Between relation.

Figure 32 A, 32B represent the Inkjet Cartridge relevant with one embodiment of the invention.

Figure 33 represents the circuit structure oftype plate 851 major parts.

Figure 34 is the time flow that drives theheat generating element 857 of each group section with the time sharing mode.

Figure 35 A, 35B represent the record head according to another embodiment of the present invention.

Figure 36 represents the relation between temperature sensor, master's (injection) heater and the secondary heater in the employed record head of one embodiment of the invention.

Figure 37 is the record head temperature distributing curve diagram.

Figure 38 illustrates the relation between prepared Chinese ink temperature and jet velocity.

Figure 39 is the curve map of bubble evolution in the explanation prepared Chinese ink.

Figure 40 is the relation curve between description heat generating element temperature and bubble volume variation and the driving pulse that is added in heat generating element.

Figure 41 and Figure 42 are the block diagrams of record head driving control system and according to the time plot of one embodiment of the invention each signal in control system.

Figure 43,44, the 45th, the block diagram of record head driving control system, the time plot of this control system and the flow chart of operation in tandem.

With reference to the accompanying drawings, explain various embodiments of the present invention.

Fig. 1 is the curve map of pulse in employed minute in the equipment of width of cloth description according to one embodiment of the invention.

In Fig. 1, Vop is a driving voltage; P₁Pulse width for first heating pulse (preheating pulse) in minute pulse; P₂Be cycle interpulse period; P₃It is the pulse width of second pulse (main heating pulse).T in addition₁, T₂And T₃Be to determine pulse width P₁, P₂, P₃Time.Driving voltage Vop is that power supply can be so that produce heat energy in the prepared Chinese ink in the prepared Chinese ink path that is made of heater plates and top board to electrothermal transducer.The amount of this electric energy is determined by the rigidity access structure or the similar structures of the area of electrothermal transducer, resistance value, membrane structure, record head.In minute pulse width modulated driving method, the pulse width that is applied is followed successively by P₁, P₂, P₃Preheat the prepared Chinese ink temperature in the pulse major control fluid passage, it is playing an important role aspect the emitted dose control of the present invention.The width that preheats pulse should be chosen as, and makes the heat energy that is produced when device is carried in the electric heating conversion for this preheat pulse be not enough to produce bubble in prepared Chinese ink.

The interval pulse time is set, is in order to prevent to preheat the interference between pulse and main heating pulse, and makes the prepared Chinese ink uniformity of temperature profile in the prepared Chinese ink path.Main heating pulse is used for forming bubble in the prepared Chinese ink of prepared Chinese ink path, to spray prepared Chinese ink by jet exit.Therefore, width P₃Should determine according to the structure of electrothermal transducer area, resistance, membrane structure and the prepared Chinese ink path of record head.

The effect of preheat pulse will be described in conjunction with the record head with structure shown in Fig. 2 A, the 2B.Fig. 2 A, 2B are according to the longitudinal sectional drawing of the record head of one embodiment of the present of invention and front view.

In Fig. 2 A, 2B, setreference number 1 is for applying the electrothermal transducer (jet heater) that the branch pulse produces heat, and this converter is contained on theheater plates 9 with electrode cable that the branch pulse is provided oranalog.Heater plates 9 is made by silicon (Si), and is bearing on thealuminium sheet 11 that constitutes the record head substrate.Thetop board 12 of a with groove is set, so that prepared Chinese ink path or analog to be provided.When this top board and heater plates 9(aluminium sheet 11) when being connected, can constitute preparedChinese ink path 3 and the normalstream body cavity 5 that is used for providing prepared Chinese ink to prepared Chinese ink path 3.Be provided withjet exit 7 on thetop board 12, preparedChinese ink path 3 communicates withjet exit 7.

In record head as shown in Figure 2, driving voltage Vop=18.0V, main heating pulse width P₃Be 4.114 microseconds, preheat pulse width P₁Excursion be the 0-3.000 microsecond.And can obtain as shown in Figure 3, ink ejection amount Vd(ng/dot) and preheat pulse width P₁Relation between (microsecond).

Fig. 3 is the graph of relation of emitted dose and preheat pulse.In the drawings, Vo is P₁=0(microsecond) emitted dose the time, and this emitted dose is relevant with the structure of record head shown in Figure 2.In this embodiment, if environment temperature TR=25 ℃, emitted dose Vo=18.0(nanogram/drip then).

Shown in the curve a among Fig. 3, in 0 to PILMT pulse width variation scope, emitted dose Vd is with preheat pulse width P₁Increase and linear increasing.When overstepping the extreme limit a some PILMT, this variation is non-linear, and reaches capacity at maximum pulse PIMAX place.

At emitted dose Vd with pulse width P₁Change and in the scope of linear change, promptly in the scope that reaches pulse width PILMT,, can control emitted dose effectively by changing the mode of pulse width PI.On curve a, PILMT is 1.87 microseconds, this moment emitted dose (VLMT) be the 24.0(nanogram/droplet).Pulse width PIMA when emitted dose Vd is saturated is the PIMAX=2.1(microsecond), the emitted dose VMAX=25.5(nanogram of this moment/drip).

When pulse width greater than PIMAX, emitted dose Vd will be less than VMAX.Its reason is as follows.When applying preheat pulse, on electrothermal transducer, will generate minute bubbles (momentary status before the film boiling), and will before bubble extinguishes, apply next main heating pulse with so big pulse width.These minute bubbles have disturbed the bubble that produces by main heating pulse, have reduced emitted dose therefrom.This zone is called as bubble and generates the zone in advance, in this zone, is quite difficult with preheating pulse control emitted dose.

In Fig. 3, emitted dose as pulse width at P₁The straightway slope of function in the=0-PILM zone in curve map is defined as the preheating coefficient correlation, and the expression formula of this coefficient is

Kp=Δ Vdp/ Δ P₁(nanogram/microsecond is dripped)

P is temperature independent for this COEFFICIENT K, but relevant with recording head structure, drive condition, prepared Chinese ink characteristic or similar parameters.In Fig. 3, curve b, c are used for other record head.This shows, if the record head difference, spray characteristic also is different.If therefore record head difference, heating pulse P₁Upper limit PILMT also be different.Can control emitted dose by the upper limit PILMT that determines each record head.Also will be illustrated below this.In this embodiment, when using by record head shown in the curve a and prepared Chinese ink, its Kp is that 3.209(nanogram/millisecond drips).

Another factor that influences the ink jet print head emitted dose is the temperature of record head (temperature of China ink).

Fig. 4 represents the temperature variant relation of emitted dose.

Shown in curve a among Fig. 4, emitted dose Vd is with the environment temperature TR(=record head temperature T H of record head) rising and linear increasing.The frequency of this linearity range is defined as temperature correlation coefficient, and can be expressed as

KT=Δ V_DT/ Δ TH(nanogram/degree drips)

This coefficient is relevant with drive condition, and relevant with recording head structure and black characteristic juice etc.In Fig. 4, curve b, c represent the situation of other record head.In the record head of this embodiment, KT=0.3(nanogram/degree drips)

Utilize Fig. 3 and relation shown in Figure 4, can control emitted dose in an embodiment of the present invention.

The following describes the emitted dose control method of utilizing dipulse.

Fig. 5 represents prepared Chinese ink temperature T ink(degree) and ink viscosity η (centipoise) between relation.This relation curve shows that ink viscosity reduces with the rising of prepared Chinese ink temperature.Therefore, if the prepared Chinese ink temperature is Ta＜Tb, η a＞η b then.

Fig. 6 represents as main pulse P₃The generation situation of bubble when providing bubble to generate needed predetermined power.As shown in the figure, when the prepared Chinese ink temperature not simultaneously, promptly when ink viscosity not simultaneously, the interface of air bubble expansion also is different, for the situation of Fig. 6 (A), temperature T a is lower, thereby prepared Chinese ink density η a is higher.Because the resistance Ra(η of the resistance expanding bubble pressure P o that ink viscosity produces) bigger, therefore the air bubble expansion interface shown in chain-dotted line is also less relatively.For the situation shown in Fig. 6 (B), b is higher for the prepared Chinese ink temperature T, thereby prepared Chinese ink density η b is lower.Like this, because the resistance Rb(η of the resistance expanding bubble pressure P o that ink viscosity produces) less, then the air bubble expansion interface of being represented by chain-dotted line is enlarged.In the record head of reality, the flow passage resistance is different at upstream and downstream, can stablize spray characteristic thus and recharge characteristic, so bubble is asymmetric.

In order to increase the emitted dose of prepared Chinese ink, increase the prepared Chinese ink temperature that air bubble expansion zone and bubble volume not only need to consider close heater, also to consider prepared Chinese ink temperature away from heater.This embodiment just is based upon on this consideration.

Fig. 7 (A) expression utilizes near the ink jet print head profile that utilizes heat energy the nozzle, and Fig. 7 (B) is an expression prepared Chinese ink Temperature Distribution time history plot.Applying preheat pulse P₁Afterwards.Fig. 7 (C) expression preheats pulse P₁With main heating pulse P₃Between relation curve.

Shown in the solid line among Fig. 7 (B), applying pulse energy P₁After moment t₁(microsecond), higher from the prepared Chinese ink temperature of heater very near (a, b, b '), but from the rapid step-down of prepared Chinese ink temperature of heater (c, c ') far away slightly.

Shown in a little line, applying pulse P₁The moment t of about 1 microsecond in back₂(microsecond) reduces near prepared Chinese ink (a, b, the b ') temperature of heater, and from the heater prepared Chinese ink t constantly of (c, c ') far away slightly₁The time temperature increase to some extent, from the prepared Chinese ink temperature of heater more farther (d, d ') rising is arranged slightly also.

Shown in two dot dot dash, applying pulse P₁After several microseconds after and applying main heating pulse P₃Moment before is t constantly₃Further reduce near the prepared Chinese ink temperature on the heater locations (a, b, b '), from heater slightly at a distance the prepared Chinese ink temperature of (c, c ') further raise, the prepared Chinese ink temperature of (d, d ') has approached the prepared Chinese ink temperature near the heater place from the heater farther place.

By as can be known aforementioned,, after applying pulse energy, need cycle regular hour (blanking time P in order on heater position suitably far away, to improve the prepared Chinese ink temperature₂).Carrying out hot the conduction in the time dependent process of prepared Chinese ink Temperature Distribution that is produced, it is constant that the gross energy in adiabatic system keeps.

Because at moment t₂The time, the prepared Chinese ink temperature of locating near heater locations (c, c ') is not enough height, and higher near the temperature of heater locations (a, b, b '), thereby at moment t₂Apply main heating pulse P₃The time air bubble expansion zone that produced than at moment t₃It is little to apply the air bubble expansion zone that main heating pulse produces.Therefore, the ink jet amount is little.Be understood that, blanking time P₂Should be long enough to make preheat pulse P₁Energy spread, otherwise, help the temperature of adjacent prepared Chinese ink of air bubble expansion not high enough, will cause less air bubble expansion.In other words, blanking time t₂Should be enough to make and preheat pulse P₁The air bubble expansion interface of energy spread around the heater, that is to say the prepared Chinese ink Temperature Distribution that is enough to around heater, provide expection.This shows, blanking time P₂And preheat pulse P₁Length aspect the emitted dose control be an important parameter.

By as can be known aforementioned, the injection control principle of this embodiment is, by variable thermal pulse P₁Be provided for improving the variable energy of prepared Chinese ink temperature, and blanking time the energy that is provided be delivered to the air bubble expansion interface zone so that required prepared Chinese ink Temperature Distribution to be provided, then, apply main heating pulse P by being provided with₃To spray required prepared Chinese ink.

In other words, utilize the preheat pulse P of dipulse₁With prior to main heating pulse P₃P blanking time₂Can be used to prepared Chinese ink Temperature Distribution T(X, Y, the Z that expection is provided to the zone at bubble interface around the heater with the energy that provided with at elapsed time after it effectively), with for the zone to its interface around the heater provides ink viscosity distribution η (X, Y, Z), can control emitted dose by the control air bubble expansion thus.

As will in conjunction with Fig. 9 (1), (2), (3) describe in detail, for effectively with preheat pulse P₁Power conversion for spraying energy, both made when ink ejection amount near maximum, i.e. preheat pulse P₁Length when being maximum, blanking time P₂Length also should be than preheat pulse P₁Width much bigger.Use the longest preheat pulse P₁The time, the energy that applies is also maximum, and the prepared Chinese ink temperature of close heater is for the highest.Yet, unless blanking time P₂Long enough, otherwise the expansion of bubble can not reach maximum.

By improving the prepared Chinese ink temperature of approaching and close heater, can improve air bubble expansion speed, and can increase the evaporation capacity of prepared Chinese ink.The expansion acting in conjunction in this air bubble expansion zone can increase the emitted dose of prepared Chinese ink.

Fig. 8 is the curve map that is used to explain according to the emitted dose control of one embodiment of the present of invention.Principle below with reference to this emitted dose control of this description of drawings.

As shown in Figure 8, emitted dose control comprises following three aspects:

Temperature according to record head:

(1) TH＜TO: control emitted dose with temperature-controlled process

(2) TO＜TH≤TL: with dividing pulse width modulated control emitted dose

(3) TL＜TH＜TC: do not control (PI=O).

At this, when TH 〉=TC, will generate the limit above the bubble of ink jet print head.

Be understood that, when record head temperature T H be not higher than relatively low temperature T O(such as, 25 ℃) time, available preceding method is controlled its emitted dose by the record head temperature, and it is higher relatively to work as TH, such as when being higher than temperature T O, the change described in conjunction with Figure 3 of available front preheats the method for the pulse width of pulse, controls its emitted dose.

The reason that changes the emitted dose control model according to the record head temperature is, in the relatively low zone of temperature, for bubble generates the heat of supplying with prepared Chinese ink is unsettled sometimes, so, thereby make that controlling emitted dose with pulse-width modulation method becomes quite difficult owing to ink viscosity causes the ink jet instability.Therefore, when the record head temperature was low, the usable temp control mode controlled to predetermined temperature (TO) with the record head temperature, so that constant ink jet amount to be provided.When the record head temperature is enough high, can modulates and preheat the emitted dose of pulse with control prepared Chinese ink.

Temperature T O is the target temperature of temperature control record head.When the record head temperature is TO, can in the control of the emitted dose of this embodiment, obtain target emitted dose Vdo(such as, 30 nanograms/drip).Consider the relation curve between temperature shown in Figure 4 and the emitted dose, the temperature T L that emitted dose reaches capacity shown in Fig. 8 can select under the temperature corresponding to control limit emitted dose VLMT shown in Figure 3.

The pattern that exemplifies above (1) is corresponding to the temperature-controlled area territory among Fig. 8, and main carrying out under low temperature environment to keep predetermined emitted dose, and the temperature (temperature of prepared Chinese ink) that will write down by temperature control controls to target temperature TO.Like this, just, can provide emitted dose Vdo in the moment of TH=TO.

In this embodiment,, get TO=25 ℃ in order to reduce temperature controlled relevant issues (ink viscosity increases, and the prepared Chinese ink that produces because of water evaporates in the prepared Chinese ink solidifies and temperature control fluctuation).Such as under the environmental condition of routine, room temperature can remain 20-25 ℃.If the record head temperature remains this temperature, then above-mentioned each problem can easily achieve a solution.Selection preheats the pulse width P of pulse₁Be PILMT, so that at t₁Can provide maximum injection quantity VLMT in the time of=25 ℃.Shown in Figure 9 as what below will illustrate, in the control model (1) of this embodiment, P₁=1.87(microsecond), P₂=2.618(microsecond), P₃=4.114(microsecond).They are corresponding to 1 in the form among Figure 10.

The control model that exemplifies above (2) is corresponding to the pulse width modulation zone among Fig. 8.In this zone, the record head temperature is higher relatively, promptly raises owing to carrying out spraying or environment temperature self temperature cause that rises, and makes the temperature of record head be not less than for example 26 ℃-44 ℃ of TO().Use the temperature sensor detected temperatures, and, change preheat pulse width P1 according to form shown in Figure 10.Fig. 9 represents the pulse width corresponding to each numeral in the form of Figure 10.Figure 11 is the continued operation flow chart of this pulse width modulation.For the record head of this embodiment, the upper limit PILMT of pulse width P1 gets the value shown in thelabel 1 among Fig. 9, i.e. value OA(Hex shown in theform number 1 among Figure 10).As described below, can set this upper limit by the positional information in the form.

Utilize pulse width modulation shown in Figure 8 to implement the emitted dose control mode below with reference to Figure 11 explanation.For example can respond per 20 milliseconds of intervals once and begin to carry out operation in tandem shown in Figure 11.At step S401, the temperature of detection record head.At step S402, obtain mean temperature, to eliminate the detection error that heat flux changes and/or electronic noise was produced because of entering temperature sensor in the record head temperature of detected first three time of step S401.At step S403, average temperature tm and last average temperature tm-1 are compared) to obtain its difference T=Tm-(Tm-1.Judge that then whether this temperature gap T is less than predetermined temperature level width Δ T, be whether this difference T is less than a temperature range, even pulse width P1 changes with unit pulse width (0.187 microsecond) and also can not change its emitted dose in this scope, the unit pulse width corresponding to table 10 in each corresponding position of numeral pulse width variation (± Δ T corresponding among Figure 10 ± temperature range of 1 ℃ (2 ℃)).If then in step S405, keep pulse width P1.If difference T then changes program step S406 over to greater than+Δ T, the numeral in the form shown in the figure 0 is improved one grade, so that pulse width P1 is reduced by one grade to reduce its emitted dose.If difference then changes program step S404 over to, with the digital slow astern shelves in the form shown in the figure 0, so that with pulse width P less than-Δ T₁Increase by one grade to increase its emitted dose.Control by this way to keep stable ink ejection amount Vdo.Pulse width P1 varies with temperature and the reason that changes a unit pulse width is, can eliminate like this because of for example because sensor provides the feedback operation of the mistake that wrong temperature detection causes, thereby can avoid beating of density of image.In this embodiment, the record head temperature is set to the mean value of the right side, a left side (2) temperature sensor output signal.

Consider the temperature detection of the mistake that causes because of sensor noise or similar factor, can get the mean value that detects for four times as detected temperatures, to realize FEEDBACK CONTROL stably.And, reduce by the variable density that produced of control, to prevent or to be suppressed at the generation of the connection colour band that causes because of variable density in the continuous printing.

Adopt above-mentioned control, for target emitted dose Vdo be ± Δ V by table-driven temperature range among Figure 10.The variation of this emitted dose is shown in the arrow a among Fig. 8.

If changing, emitted dose is within this scope, then both made in 100% continuous printing, also the variable density that produces in once printing can be suppressed to ± Δ 0.2, therefore, both having made is in continuous print system, and the heterogeneity of density of image or connection colour band phenomenon also are unconspicuous.If increase the quantity obtain average data, by can reducing noise effect, and make variation milder, yet when control in real time, accuracy of detection may reduce, thereby hinder correct control.If reduce this quantity, noise effect will become clearly, and take place sharply to change.But when control in real time,, just can control accurately as long as improve accuracy of detection.

Control model (3) is corresponding to territory, noncontrolled area shown in Figure 8.This zone is in outside the normal print area of record head usually, thereby it seldom is used.But for example when record head carried out 100% continuous printing continuously, its temperature just may fall into this zone.For this situation, only be provided for main heating pulse (the individual pulse) (P that prints₁=0), to reduce the rising of self temperature.Temperature T C is the adaptable range limit of record head.

In this embodiment, use form shown in Figure 10, carry out operation in tandem shown in Figure 11, can before the record head temperature reaches TH=46 ℃, control, and can be with respect to central-injection amount Vdo=30(nanogram/drip) emitted dose is controlled at Δ V=± 0.3(nanogram/drip) scope in.

Figure 12 represents to be adapted to the heater plates of the record head in the previous embodiment.This heater plates is provided with temperature sensor, temperature control heater and jet heater.

In the top view of heater plates shown in Figure 12,temperature sensor 20A and 20B are arranged on right side and the left side of thejet heater row 1 on the silicon substrate 9.Be arranged onjet heater 1,temperature sensor 20A and 20B andtemperature control heater 30A, the 30B in heater plates right side and left side, all make a plate and moulding by production process of semiconductor.In this embodiment, detected temperature value is the output signal mean value oftemperature sensor 20A and 20B.

Figure 13 represents to be equipped with according to embodiments of the invention the ink jet recording device of injection of the control system.This printer is panchromatic continuous type printer, and it is applicable to the record head with the black (BK) of removably installation, navy blue (C), magneta colour (M), yellow (M).The operating characteristics that is used for each record head of this printer is: resolution ratio 400dpi, 4 kilo hertzs of driving frequencies and be provided with 128 jet exits.

In Figure 13, be provided with four record head print cartridge C that are respectively applied for Huang, deep red red, dark blue and black prepared Chinese ink material, each print cartridge comprises a record head and the accumulator of prepared Chinese ink is provided to this record head.Each record head print cartridge C is contained on the printer carriage by unshowned mechanism withremovably.Balladeur train 2 can slide along the axis ofguide 11, and links to each other with a part by the motor-driven rotatingband 52 of unshowned main scanning.Therefore, record head print cartridge C can scan mobile along the axis of guide 11.Paper feeding cylinder 15,16 and 17,18 is located at the rear side and the front side of sweep record head cartridge C posting field respectively, and parallels with the axis ofguide 11 basically.Paper feeding cylinder 15,16 and 17,18 is by paying the sweep record motor-driven to carry recording materials P.The surface of recording materials P record-oriented head cartridge C ejection side is to provide recording surface.

Figure 14 represents to be used for the time-write interval relation of four kinds of colors of panchromatic spraying.The record head print cartridge that is respectively applied for different colours is located on the balladeur train by predetermined space, and in the moving process of balladeur train, writes down operation.Therefore, each record head printing needs to carry out constantly in difference, to compensate the interval between each record head.

In a part recovery system unit is set in the face of print cartridge C moving area.This recovery unit comprises the lidlinear element 30 that is provided with respect to each the print cartridge C with record head.It can be with balladeurtrain 2 smoothly to the right or be moved to the left, and can vertically move.When balladeurtrain 2 was in zero position, the lid linear element contacted with record head to cover record head.Resetter also comprises wiping examination element that is made of first and second blades 401,402 and theblade cleaner 403 that is made of the prepared Chinese ink absorbing material, to cleanfirst blade 401.

Recovery unit also comprise one by means of lidlinear element 300 from record head jet exit and the suction and pumping prepared Chinese ink or the pump unit 500 of thing seemingly near it.

Figure 15 is the control system block diagram of ink jet recording device.

Control system comprises thecontroller 800 as main control unit, this controller comprises the CPU CPU801 of the microcomputer form that is used to carry out operation in tandem shown in Figure 8, be used to store the read onlymemory ROM 803 of current potential amplitude, pulse width and other fixed data supervisor of the operation in tandem program of finishing, form shown in Figure 10, heating pulse, have the randomaccess memory ram 805 in the local register district that is used to handle pictorialdata.Reference number 810 is as the main process equipment in pictorial data source (for example, figure image reader).By interface (I/F) 812 transmission diagram image data, command signal, status signal or similar signal between controller.

Reference number 820 expression bymain switch 822, be used to instruct thereproduction switch 824 that duplicates or write down the operation beginning, be used to instruct the large scale of carrying out the large scale recovery operation to recover one group of switch that switch 826 constitutes.These switches are operated by theoperator.Reference number 830 is one group of sensor, it comprise be used to detect balladeurtrain 2 zero positions, it the original position or thesensor 832 of similar position, be used to detect the pump position that comprises valve 530sensor 834, be used for other sensor of checkout equipment state.

Recording head driver 840 is according to the electrothermal transducer (heater) (driver that illustrates only is monochromatic driver) of record data or similar data-driven record head.The part of recording head driver is used foractuation temperature heater 30A, 30B.Send intocontroller 800 by the detected temperature signal oftemperature sensor 20A, 20B.Main scanning motor 850 is along themobile balladeur train 2 of main scanning record direction (right side-left among Figure 10 to).Motor 850 is driven by driver 852.Subscan motor 860 is used for carrying recording materials along sub scanning direction.

The following describes the record head that is applicable to Figure 13 and Figure 15.

Figure 16 represents to be installed in removably an example of the record head print cartridge on the balladeur train of ink jet recording device shown in Figure 13.In this embodiment, print cartridge comprises whole Chu Mo unit IT and head unit IJU.Install with removably between them.Conductor jointer 102 is used to receive the signal or the similar signal of the ink sprayer 101 of activation record head, and is used to export prepared Chinese ink maintenance dose detection signal.This connector and head unit IJU and ink container unit IT linearly are provided with.Like this, when being installed in print cartridge on the balladeur train in the following manner, can reducing its height H, thereby can reduce the thickness of print cartridge.As shown in Figure 13, when each print cartridge is set up in parallel, can also reduce the size of balladeur train.

Utilize the mounting board spare 201 on the ink container unit IT, the record head print cartridge can be installed in jet 101 mode down.Mounting board spare 201 is meshed with a platform on the following balladeur train that will illustrate.When record head was installed, one or several pin on the balladeur train will be meshed with the pin mate 103 on the head unit IJU, so that head unit IJU is correctly located.

Record head print cartridge among this embodiment is provided with in its ink jet side 101 and is used to wipe examination ink-jet side 101 with the absorbing material 104 with its cleaning.Form air hole 203 at the middle place that is positioned at ink container unit 200 substantially, in order to import air according to the prepared Chinese ink consumption.

When using Figure 13 or device shown in Figure 15, utilize said PWM control can print various print patterns, and confirmed that the variable density in the peculiar sweep record line of continuous type printer is inhibited, on one page paper or the density of image between several pages of paper change and also can be inhibited.Special needs to be pointed out is that it can be eliminated the emitted dose that is caused by variation of ambient temperature and change.When by preheating pulse width modulation when operation shown in Figure 17 A, although because of environment or print continuously and produced variations in temperature, its tone intensity repeatability (gamma curves) still remains unchanged.Therefore, be stable by the formed tone balance of navy blue, magneta colour, yellow and black, can produce the full-colour image that keeps constant color reprodubility.

Figure 17 B represents not preheat the situation of pulse width modulation.Just as shown in FIG., its repeatability varies with temperature and changes.

In Figure 17, density data 0-255 is corresponding to the 1-16 of 17 grades of tone datas.

In this embodiment, can be by the emitted dose scope of pulse width modulation control, the temperature range of often using during corresponding to actual printing, and,, and, use individual pulse to reduce the rising of temperature in the high-temperature region by heater control temperature at low-temperature space.Can in the variation of ambient temperature scope of broad, make emitted dose keep stable like this and make density of image keep stable.

Monochromatic continuous printer (only lifting black) below in conjunction with said PWM control explanation HC hard copy head.

The performance indications of this record head are: resolution ratio 360dpi, 3 kilo hertzs of driving frequencies are provided with 64 jet exits.In this case, only use a temperature sensor, for the sake of simplicity, do not comprise temperature control in its emitted dose control method.For this pulse width modulated sequential operation, be in single pass, to detect mean temperature, and change the pulse width P1 of each scan line.

Because printer is the black monochrome printers, thus although it is very simple, also can suppress the generation that each connects colour band in the ranks, or the generation of density of image difference in each row, therefore, this simple operations remains effectively.

The following describes a kind of capable full multiinjector record head of permanent type that satisfies flying print.This also is a monochrome printers that is used in combination with PWM control.

The record head performance parameter is: resolution ratio is 200dpi, 2 kilo hertzs of driving frequencies.1600 jet exits are set.Per 16 of jet exit is one group of section, forms 100 group sections altogether.Need corresponding temperature sensor be set at each group section jet exit by drive system.The temperature signal of using the temperature sensor by each group section jet exit to obtain is controlled the pulse width modulation of this group section, and has nothing to do with control of other group section.Like this, both made because of peculiar jet exit of line item head and non-jet exit exist the temperature heterogeneity that causes record head to distribute entirely, also can control the emitted dose of the jet exit of each separate group of section, thereby can carry out high-quality and high-speed printing, density of image inhomogeneities phenomenon can not appear.

To illustrate that below the PWM control that utilizes this embodiment reduces record head because of printing produced effect that self temperature rises.

Figure 18 represents because record head self temperature rising TUP that printing produced and preheat relation between pulse width P1.Printing effect is increased to 100% with 25% growth rate from 75%.The value PUT that self temperature rises is the value of delegation when connecing a line printing.Be understood that record head will raise with the increase that preheats pulse width P1 because of self temperature that printing causes rises, and will raise along with the increase of printing effect (number of nozzle in the unit interval or spray quantity).Be understood that thus when printing effect improved, preheat pulse width P1 should suitably shorten to suppress the rising of self temperature.From the viewpoint that the record head temperature raises with the increase of printing effect and time-write interval, this embodiment of the present invention is the record head temperature that detects near the record head jet heater, and according to detected temperature, controls and preheat pulse width.Carry out PWM control by this way, can suppress self temperature rising effectively.

Figure 19 represents that the record head temperature is followed successively by 25%(1 with various printing effects), 50%(2), 75%(3), 100%(4) the curve map that changes of printing interval.In Figure 19, a represents the situation of fixed pulse width pattern, the situation when b represents with the PWM control method preheat pulse width P1 to be become suitable width corresponding to the record head temperature.By being not difficult to find out among the figure, PWM control can reduce record head self temperature effectively and rise, during high efficiency is printed or all the more so under hot conditions.

Be exactly more precisely, when printing operation by printing effect shown in Figure 180, its preheat pulse width P1 will be by the PWM control mode according to operated self the temperature rising situation that is produced by this record, reduce along the direction shown in a among Fig. 8, reduce to supply with per unit thus and print the heat energy of symbol, rise thereby can reduce because of printing self temperature that is produced.

The following describes and use the HC hard copy head particularly to use the rise color printer of control of self temperature.

In this embodiment, the pulse change table does not resemble among first embodiment and divides by the stationary temperature scope shown in Figure 10, but this pulses switch becomes faster along with the rising of record head temperature.When the temperature of record head was low, the unit temperature level was ± Δ T, and promptly the temperature width that preheats among Fig. 7 in the form is bigger, and along with the rising of the temperature of record head, this width level ± Δ T reduces.Can further reduce effectively like this under hot conditions because of printing self temperature that is produced and rise.

This control can be in PWM zone shown in Figure 8, and record head temperature T H carries out in 26.0 ℃-44.0 ℃ the scope.Here, self temperature that is produced because of printing and variation of ambient temperature rises, be called as the record head temperature and detected, and on the basis of this temperature detection, with temperature width level or growth rate be ± Δ T=4 ℃-1 ℃ of change preheat pulse width P1 by form shown in Figure 20.

Its operation in tandem is same as shown in Figure 11.

Because the characteristic of record head, in cryogenic conditions (from about room temperature to 40 ℃) rare problem down.But owing to, make record head under hot conditions, become to responsive to temperature such as bubble unstability that generates and the heat problems such as reduction that recharge frequency, all the more so for the hot type ink jet recording device.Therefore, should avoid as far as possible under the condition of high temperature, operating.Hence one can see that, should control to avoid entering high temperature side.

Utilize control form shown in Figure 20, preheat pulse width P1 is along with the rising of record head temperature changes sooner, thereby at high temperature side, can suppress more to rise because of printing self temperature that is produced.This is as shown in Figure 21, and in the figure, curve a is to use self temperature rising curve when of the present invention, and curve b is self temperature rising curve when being used to change the temperature width that preheats pulse width P1 and being constant.

By being not difficult to find out among the figure, when the record head temperature is low (being lower than 40 ℃), self temperature that produces because of printing rises bigger, but at crosspoint C place, this trend is reversed, when the record head temperature further raises, (be not less than 40 ℃), carry out preheat pulse width P1 quickly and change to suppress self temperature rising.

In this embodiment, temperature width changes by shown in Figure 10, but the degree of this variation can be selected according to operating condition.

Describing below rises with this self temperature suppresses the monochrome printers that control combines.

Printer among this embodiment is suitable for the exchangeable record head.To this situation, need be when changing record head each, emitted dose control (control temperature width/or control impuls width) is located at suitable emitted dose state.Therefore in this embodiment, printer is monochromatic, allows thicker emitted dose control, and the speed that reduces of preheat pulse width P1 is reduced with the rising of temperature, thereby self temperature that suppresses record head rises.

By control form shown in Figure 22 as can be seen, the variable quantity of the preheat pulse width P1 that forms by impulse transfer increases with the rising of record head temperature, thereby self temperature that can further suppress to produce because of printing raises, and this is similar to variation tendency shown in Figure 21.

As from the foregoing, according to the present invention, when the heat generating element of record head during also by a plurality of pulse excitation for example, the pulse energy of first pulse changes by the pulse width modulation of for example carrying out according to the record head temperature, the emitted dose of prepared Chinese ink can be controlled like this, and the temperature rising of record head can be suppressed.

Consequently, make the energy of supplying with heat generating element drop to minimum of a value and rise, and can control ink ejection amount with self temperature of the record head that reduces to be produced because of printing.Can avoid density of image to change thus, and can stablize color balance.

This embodiment of the present invention can eliminate effectively or be suppressed at during the printing that characteristics of inkjet that the variation owing to emitted dose causes changes and prepared Chinese ink variations in temperature, the injection direction that is caused changes, sprays failure, refills that frequency reduces or the recording head structure that is caused changes the unfavorable factors such as control characteristic variation that produce because record head self temperature rises because record head self temperature rises.

Second advantage is that because the temperature of record head reduces, can prolong greatly the service life of record head.

The following describes the record head temperature-detecting device.It can be the form of a direct detection record temperature.Can be contact or contactless.It preferably forms as one with the substrate with record head heat generating element.As the indirect temperature checkout gear, it should be according to the temperature of control device (CPU, capacitor or like) etc., dopes the temperature that relevant record head drives.This forecasting type sensor is effectively reducing aspect the temperature detection fluctuation, and same temperature sensor can be set on printer main body, to realize control stably.

Can adopt following manner to the waveform selection (changing or distortion) that is used to drive signal.Can be as shown in Figure 9 for its basic waveform.The selection of this waveform, distortion and change can be undertaken by following mode, according to its pulse width of temperature change previous section P1 in (supply cycle), according to temperature change its off period of P2, in the cycle ia of a predetermined driving signal or similar signal, change its leading part P1 and deadline part P2 ratio.

In this embodiment of the present invention, preferably use constant main driving pulse P₃, and in the zero-sum predetermined period, change leading part P1.But the present invention also comprises the main driving pulse P of change₃

As previously mentioned, at P off period₂Middle voltage is preferably zero.But at quiescent period P₂In, also can apply the predetermined voltage that is lower than P1 and P3 voltage constantly.Can make pulse P1 and P3 to be sine-shaped form service voltage by converted-wave.

For electronic loop, can be the assembly of preamble pulse generator and main drive-pulse generator.In a kind of modification loop, a part of output signal that can select the isopulse generator is as the strobe pulse that provides to heat generating element or electrothermal transducer.In another kind of modification loop, can select and design preamble pulse P₁With main driving pulse P₃Service time, and electrothermal transducer is supplied with in the pulse that will select or design.Other distortion can suitably be selected by those skilled in the art.

Drive signal and be meant the signal integral body that in electrothermal transducer, causes bubble to generate according to instruction.When the driving signal comprised a plurality of pulsed quantity, preamble pulse was called as " main pulse ".Preamble pulse can comprise a plurality of pulses.When a plurality of preamble pulse, it is multistage driving signal that the driving signal can be described as.When using a plurality of preamble pulse, be meant the interval between last preamble pulse and the main pulse quiescent time.

Embodiment 2

In this embodiment, will revise the variation of each record head emitted dose of producing in the record head production process.

Figure 23,24, the 25th is according to the main control flow chart of the ink jet recording device of one embodiment of the invention.At first with reference to flowchart text main control mode.When main switch started, equipment carried out the initial inspection operation of step S1.In the initial inspection operation, should check ROM and RAM, to guarantee that program and data adapting are in proper operation.At step S2, the correction value in reading temperature sensor loop.At step S3, carry out the detecting operation of initial mounting board then.In this embodiment, it is closed both having made the Qianmen, also will carry out initial mounting board detecting operation at step S3.Being used in the required project of next step reading and recording header at step S4 detects equipment.From the ROM of record head, read data at step S5.S6 is provided with primary data in step.

At step S7, begin to carry out initial temperature and be 20 ℃ temperature control, when step S8 connects main switch, whether need to carry out recovery operation and discern (1) (whether discern needs to carry out the suction and pumping recovery operation).

Figure 26 represents that initial temperature is 20 ℃ temperature control flow figure.In this flow chart,, time counter will be inserted in 30 seconds at step S2001.Subsequently, if temperature is higher than 20 ℃, then finish the operation of this flow process by step S2002.If temperature is lower than 20 ℃ then at the heater of step S2003 activated head.Whether finish in step S2004 identification timing in 30 seconds.If finish this starting by step S2005 then; If not, then operation is returned step S2002.

Below with the operation in tandem of declare record wait state.

Operation in tandem when the following describes SBR.Carry out 20 ℃ of temperature controls at step S9.Carry out standby invalid spraying at step S10.At step S11, detect the paper that occurs.If there is not paper, then operation changes step S21 over to, and whether identification cleaning button is pressed.If then carry out clean operation by step S13.If be pressed at step S14 RHS button, then insert the RHS mode flag by step S15.Here, " RHS " expression is used for the record head of effective density heterogeneity coloring process.Read the density heterogeneity of print pattern by reader, and revise this heterogeneity.

If by artificial paper supply, then insert artificial paper supply sign at step S17 at step S16, its operation changes step S22(over to and duplicates the beginning sequence).If start the OHP button at step S18, then insert the OHP mode flags) at step S19.If opposite, then remove the OHP mode flags at step S20.If S21 presses reproduction button in step, then operation changes over to and duplicates beginning sequence (step S22).If reproduction button is not pressed, then operation is back to step S9.If finish at step S13 judgement clean operation, then operation turning back to step S9.

The following describes the operation of replication sequence.In of the rising of step S22 drive fan with the inhibition internal temperature.At step S23, begin 25 ℃ of temperature controls.At step S24, judge whether to provide paper.If no, then carry out invalid spraying (1) (N=100) at step S25.Then operation is changed over to step S29.Wherein, N is invalid emitted dose.At step S26, judge whether to carry out recovery operation (2) (whether judge needs to carry out the suction and pumping recovery operation before paper supply).Then, at step S27 paper supply.Width and material in step S28 test paper.Judge whether to need to move image at step S29.If then carry out subscan and move (mobile paper) by step S30.If image does not need to move, then operation changes step S31 over to, whether is not less than 25 ℃ in this step detection record temperature.If then judge whether to carry out the necessity (carrying out recovery operation) of recovery operation (3), and carry out a line item by step S33 and operate according to non-covering cycle prepared Chinese ink evaporating capacity.Judge whether to carry out recovery operation (6) (judging whether to carry out recovery operation) by S34 then, and supply with paper by step S35 according to wiping the examination time.

At step S36, judge whether the record operation finishes.If the data that then will indicate number of copies etc. write ROM, and change operation over to step S37.If not, then operation changes step S31 over to.At step S37, whether judgment device should be transformed into SBR.If operation changes step S38 over to.

Operation after the step S38 is the program as the paper discharging operation, carries out the necessity (remove bubble after printing, remove the bubble in the chamber, the unallowed condition of high temperature is cooled off, recover) of recovery operation (4) after judgement a piece of paper has been printed.At step S38, judge whether to discharge the operation of paper.If not, then temperature is reduced to 45 ℃ or lower by step S39, S40, S41, if temperature reduces quantity not sufficient in two minutes, then stop excitation by step S42.When temperature is reduced to 45 ℃ or when lower, wipe the examination operation by step S50, and carry out invalid spraying (N=50) by step S43.At step S48, cover jet exit.Carry out the paper discharging operation if desired, then paper is discharged by step S44.At step S45, judge whether that indication continues to print.If then carry out the necessity of recovery operation (4), and make operation return step S24 by step identification.If not, then carry out recovery operation (4) by step S46.After identification, similar with the situation that need not discharge paper, cover jet exit at step S48.S49 closes fan in step.Then, step S9 is returned in operation, and copy operation finishes.

Figure 26 B, 26C are used for 20 ℃, 25 ℃ temperature controlled operation in tandem flow charts.Judge at step S2101 whether the record head temperature is higher or lower than 20 ℃.If be higher than, then make the record head heater remove excitation at step S2102, if be lower than 20 ℃, then encourage this heater, and finish 20 ℃ of temperature control flow by step S2103.The step S2104-S2106 that the operation of 25 ℃ of temperature control flow comprises is identical with step S2101-S2103 during 20 ℃ of temperature control flow are operated.Introduce so omit in detail.

Figure 27 is the detail flowchart that the initial mounting board of above-mentioned steps S3 detects.This flow process is carried out after main switch starts immediately to detect the mounting board state.At step S201-S204, respectively by feed in sensor, grate paper-arranaging sensor, rise whether paper direction sensor and paper width sensor detection record paper or analog appear in the paper supply path or near balladeur train.If, then detect the mounting board situation with the generation alarm signal, if not, then make operation turn back to main flow.

Figure 28 is the detail flowchart that recording head information is read flow process among the above-mentioned steps S5.At step S301, read the sequence number of specific record head, at step S302, judge whether the sequence number that reads is FFFFH.If sequence number FFFFH, the then record head that lacks by step S304 identification.If sequence number is not FFFFH, then by step S303 reading and recording first prize in a lottery look information.At step S305,, judge whether record head is positioned on the determined tram of a certain color according to the colour information of reading.If record head is positioned at the tram, then operation changes step S306 over to; If be positioned at errors present, then operation changes step S307 over to.

At step S306, remaining recording head information, for example print pulse width, temperature sensor correction, number of copies, wiping examination operand etc. and data are stored.Judge according to the sequence number of record head whether mounted record head is new at step S308.The sequence number of record head is stored among the reserve RAM all the time, thereby it can compare with new data.If two sequence number differences, then decidable is the new record head, if identical, thinks that then record head does not have to change.In this embodiment, above-mentioned judgement is that each color in black, navy blue, magneta colour and the yellow is carried out.If record head is not new, then the record head signal fetch program finishes.If record head is new, then step S309 will count out such as sequence number, colouring information, print pulse width, PWM, recording head information such as temperature sensor correction term, number of copies, wiping operation number deposits in the memory of equipment.In addition, the sign (or data) of indication having been installed the new record head deposits memory in.The HS data (weight information) of reading record head at step S310, at step S311, the time of utilizing the clock of equipment that the new record head is brought into use writes nonvolatile storage, and the end record header fetch program.

The following describes using method as the ROM of recording head information storage device.

In equipment of the present invention, use be replaceable record head (print cartridge type).Therefore it helps the user to change record head at any time.Because record head is mass-producted, each record head can be because of inevitably production error or deviation are different.Therefore, for high quality image stably is provided, just need revise this deviation.

With regard to the method for under drive condition, revising this deviation, the drive condition that is stored among each ROM can be write, and revise based on this, or control the variation of emitted dose in the record head that is produced because of record head jet exit Size Distribution and the heterogeneity of gross density.This is called record head weight modulation (HS).

If each record head is not carried out this correction, just can not guarantee to finish the particularly control of the stability (recharging frequency, heterogeneity, moisture state) of jet velocity, injection direction (precision of print point), emitted dose (density of image).This makes and to be difficult to the high quality image that provides stable, and causes spraying failure when printing, or since departing from of drop location produce tangible image interference.

Particularly for the situation of full-colour image, image is by four record heads, being that navy blue record head, magneta colour record head, yellow record head and black recording head are common forms, if the emitted dose of a record head or control characteristic are different with other record head, image quality will seriously descend.Wherein, the variation of emitted dose will cause the imbalance of whole color balance, thereby color and colorrendering quality are degenerated (aberration increase), and then reduce the grade of image quality.And, density of image is changed for the monochrome image of other colors such as black, redness, blueness or green.The variation of control characteristic has changed the repeatability of semi-tone image.Consider above-mentioned situation, this embodiment revises nozzle parameter.

In this embodiment, realize that with described minute pulse width modulated of first embodiment driving method record head drives.Recording head structure is identical with the record head that is used for first embodiment.The record head of this embodiment is provided with the ROM(EEPROM of each record head parameter of storage).This information is read by the printer main body assembly, to compensate the deviation of each record head.

The following describes and be used to revise each record head nozzle parameter variation so that the method for high-quality and exact image to be provided.As previously mentioned, when starting the main switch of the body assembly that record head has been housed, the information (ROM information) that is stored in the record head production process among the ROM is read by the printer main body assembly.More precisely, be to write such as the drive condition form indication of record head ID number, colouring information, TAI(record head corresponding to the print pulse width), TA₃(indication of pulse width modulation form), temperature sense degree of correction, number of copies, wiping examination operand etc.According to the form indication TA that reads₁, the branch pulse width modulated that will describe afterwards drives in the control, and body assembly has been determined main heating pulse width P3.Following each section seen in detailed description.

(1) determining of TA1:

In the record head manufacture process, the jet performance of each record head is under common drive condition, that is, record head temperature T H is 25 ℃, driving voltage VOP is 18.0V, and pulse width P1 is that 1.87 microseconds and pulse width P3 measure under the condition of 4.114 microseconds.Subsequently each record head is determined its optimum driving conditions, and this drive condition is write in the read-only storage (ROM) of record head.

(2) drive condition setting:

Body assembly allows in minute pulse width driving process, preheat pulse width P1 is set in this body assembly, blanking time width P2 and main heating pulse width P3, as shown in Figure 1, the rise time of preheat pulse is set to T1, T2 and T3, and in the present embodiment, the T3 that determines on the body assembly is 8.602 microseconds.Pulse width T of determining on the basis according to being designated as of reading ofrecord head 2 and TA1(be 4.488 microseconds for example), pulse width P3 is defined as for example P3=T3-T2=4.114 microsecond.

Figure 29 represents form indication TA1 and the relation between the main heating pulse width P3 that determines on the basis of indication TA1.

Proofread and correct by pulsewidth modulation (PWM):

This process is described to a kind of method and promptly utilizes the PWM control method to proofread and correct the variation of emitted dose of single record head to form correct image.PWM controlled condition is the part as record head ROM signal, when starting the main switch of body assembly, by body assembly, reads with ID number, color, drive condition and HS data.

In the present embodiment, form indication TA3 is as the controlled condition of PWM control.As described in later general, digital TA3 is represented as the numeral of a respective record emitted dose (VDM).According to reading TA3, the upper limit of the heating pulse width in the PWM control that the main body set of pieces is determined.This description is proofreaied and correct with reference to PWM.

(1) determining of form indication TA3:

In the manufacture process of record head, the emitted dose of each record head is under common drive condition, that is, record head temperature T H is 25.0 ℃, driving voltage VOP is 18.0V, and pulse width P1 is that 1.87 microseconds and pulse width P3 detect under the condition of 4.114 microseconds.The amount of measuring is VDM.Subsequently, determine with reference injection quantity VDO=30.0(nanogram/droplet) between poor (Δ V=VDO-VDM).According to Δ V, determine the relation between (as shown in figure 30) Δ V and the form indication TA3.This shows,, can determine the arrangement of record head, and in ROM, store the data TA3 of each record head according to emitted dose.

Because emitted dose is proofreaied and correct by changing preheat pulse width P1, when utilizing Δ V tabulation, wish that Δ V equals Δ VP, Δ VP is the variable quantity of preheat pulse width P1 in a form, and P1 can be by the branch pulse width modulated driving method control that will describe.

(2) reading of form indication:

As described at paragraph (1), influence that the recording of information head is installed in the body assembly of ink jet recording equipment among the ROM.Along with the startup of main switch, according to operation in tandem shown in Figure 22, information stored is deposited among the SRAM of body assembly among the record head ROM.

(3) determining of PWM control form:

1. under the situation of record head height emitted dose (for example VDM=31.2(nanogram/drip)), in environment temperature (record head temperature) when being 25.0 ℃, should make the pulse width P1 of preheat pulse (for example be shorter than standard drive condition (P1=1.867 microsecond), the P1=1.496 microsecond) to reduce emitted dose, make emitted dose approach standard emitted dose VDO=30.0(nanogram/drip).

Under the situation of the low emitted dose of record head (for example, VDM=28.8(nanogram/drip), in environment temperature (record head temperature) when being 25.0 ℃, make the pulse width P1 of preheat pulse (for example be longer than standard drive condition (P1=1.867 microsecond), the P1=2.244 microsecond) to increase emitted dose, make emitted dose approach standard emitted dose VDO.

3. as shown in figure 30, in aforesaid operations, the relation between form indication TA3 and the preheat pulse width P1 is to determine according to the emitted dose of each record head, thus the emitted dose VDO of total energy pay standard.

4. in the method, body assembly can have be used for standard emitted dose VDO(30.0 nanogram/drip) 16 PWM forms.Therefore, the emitted dose increment by an indication shown in Figure 21 is 0.6 nanogram/drip, and all the theoretic recoverable scopes of emitted dose are ± 4.8 nanograms/drip.Yet in fact, in order effectively to utilize above-mentioned emitted dose control method, the excursion of the correcting value of emitted dose is preferably ± 1.8 nanograms/drip.

This be because, as shown in Figure 3,, will produce pre-angry bubble if preheat pulse width P1 is too big, if preheat pulse width P1 is too little, the Controllable Temperature scope of PWM emitted dose control will be too little.

In the present embodiment, from the good density of image design and the viewpoint of color rendering scope, changing pulse width needs five steps.Usually, from enough ink jet amounts and the generation that prevents the white band and the angle of other image quality problem, has only the emitted dose that allows record head that standard is provided: VDO=30.0 ± 2.0(nanogram/drip).Utilize bearing calibration, record head supply VDO '=30.0 ± 3.8(nanogram/drip) be suitable.As previously described, body assembly is read ROM information as PWM control form indication TA3, and the body assembly drive condition of this information of response is set, so that can proofread and correct the variation of the emitted dose of each record head.Thus, use the detachable body assembly that record head is installed to stablize the quality of chromatic image not difficultly.In addition, also can increase the yield rate that record head is made, and therefore reduce the total cost of print cartridge.

As shown in figure 31, preheat pulse width P1 can change in the proper range of a corresponding record temperature T H.Or finish this variation according to operation in tandem shown in Figure 11.

Figure 31 A has represented that the reference value of pulse width P1 is OA, and the per 2.0 ℃ of situations that change one-level (1H) of preheat pulse width P1.Figure 31 B and 31C have represented that reference value is respectively the situation of OB and 09.Reference value can be stored among the ROM of record head, and can be read to produce a form or a plurality of form by body assembly.And the form of different reference values is stored in the body assembly, and wherein suitable one is selected according to ROM information.

Figure 32 A has represented the outward appearance according to the ink jet print cartridge of present embodiment.Figure 32 B has represented the printed circuit board (PCB) 85 of the print cartridge of Figure 32 A, in Figure 32 B, provided a printedsubstrate base 851, aluminothermyradiant panel 852, theheating plate 853 that comprises heat generating element and diode matrix, an EEPROM(non-volatility memory) storage density non-uniform information or similar information in advance are used for the contact electrode 855 that is electrically connected with body assembly.Omitted the jet exit that is located on the straight line for the sake of simplicity.

In order to store visual non-uniform information or the similar information at each record head, EEPROM854 is arranged on theprinting substrate 851 of ink jet record head 86, and 86 also comprise heat energy generating device and driving governor.Thus, when record head 86 was contained on the body assembly, body assembly was read from record head 86 about information such as the parameter of record head and density heterogeneities, and body assembly is finished pre-control to improve record performance according to sense information.Therefore, can guarantee high picture quality.

Figure 33 A and 33B have represented the major part of the circuit on the printedsubstrate base 851 among Figure 32.To be located on theheating plate 853 by the element in a little framework of determining of ruling.It is 16 * 8 in this example thatheating plate 853 has NXM() matrix structure, each point all has heater and thediode 856 that is used to prevent that series that unexpected electric current passes through from connecting.Heat generating element 857 is to drive with the method that the time that is used for each group divides equally.To supply with to drive can control be to realize by the pulse width (T) that control puts on section side.

The example of the EEPROM854 of Figure 33 B presentation graphs 32B.It has been stored and intensity heterogeneity or the relevant information of similar characteristics.This information is by providing corresponding to getting in touch from the serial of a command signal (address signal) D1 of body assembly.

Be used for each in the information storage of record head at ROM, and the variation of the jet performance of each record head proofreaied and correct.Needed is the device that is used for the information of transmitting to body assembly.

Figure 35 A and 35B represent the record head according to another enforcement.In these record heads, replace and the information-related ROM that passes to body assembly, on the integrated circuit block of record head, formed a plurality of pits or projection.Combination by projection or pit provides information.In Figure 35 A, information is the form of the combination of projection, and in Figure 35 B, information is the form of the combination of pit.In the middle of these examples, can hang down expense and simple structure transmission information.When record head is installed on the body assembly, body assembly mechanically, electricity ground or read optically by pit and become the projection representative, with form indication or form or the relevant information of analog, and change the control parameter, correspondingly in this printing, record head is removable, and ideal situation is that optimization control parameter is set when changing record head.Provide the method for information to be not limited to shown in Figure 35 A or the 35B these,, also can adopt part cutting or similar approach to transmit information if finish identical functions.

Shown in Fig. 3 and 4, because the tolerance of making, each record head has different parameters.Under record head temperature (TH) was constant condition, the relation between preheat pulse width P1 and the emitted dose VD was as curve b(or c among Fig. 3) shown in, that is, when being lower than the PILMT of pulse width, slope is big (less), and increment is linear; When surpassing PILMT, the bubble that is produced by main heating pulse P3 is disturbed by pre-gassing; Surpass PIMAXb(PIMAXc) time, emitted dose reduces.Under preheat pulse width P1 was constant condition, the relation between record head temperature T H and the emitted dose VD was as Fig. 4 curve b(or c) shown in, that is, with respect to the increase of record head temperature T H, its pass is big slope linear growth.The coefficient of the range of linearity is as follows:

The coefficient correlation of preheat pulse and emitted dose:

KP=Δ VDP/ Δ PI(nanogram/microsecond is dripped)

The coefficient correlation of record head temperature and emitted dose;

KTH=Δ VDT/ Δ TH(nanogram/drip)

When record head had structure as shown in Figure 2 and have characteristic shown in Fig. 4 curve b, KP=3.53(nanogram/microsecond was dripped), and KTH=0.35(nanogram/microsecond is dripped).When record head had the characteristic of curve C as shown in Figure 4, KP=3.01(nanogram/microsecond was dripped), and KTH=0.25(nanogram/microsecond is dripped).

By these two kinds of relations, in order more effectively to control the emitted dose in the said method, because relation shown in Figure 8 is different with curve b and c, so desired temperature scope and/or pulse width are optimum.As previously mentioned, optimization control parameter is read by body assembly, and after record head was changed thus, the initial injection quantity before the printing phase was proofreaied and correct and control operation changes.So, even the record head temperature changes owing to the variation of environment temperature and self temperature owing to printing is risen, the ink jet amount of record head also can be controlled to be constant.In the present embodiment, the head IC piece has recognition capability, but same or analogous structure also can be arranged in the print cartridge.

When a HC hard copy head was used for color printer, debugging work was finished before the delivery in factory, so all debugging are all wished to finish in short time.In order to eliminate the packing density that changes corresponding to input signal, respectively dark blue, deep red red, yellow and black recording head are carried out Gamma correction usually, so that suppress to worsen because of emitted dose changes the color reprodubility that causes by adjusting color balance.The color balance of the halftoning that crossing deenergizes provides, but be impossible for the correction of the basic emitted dose of continuous whole image.If so do by changing Gamma correction, then can produce density increases or other problem.

According to this embodiment of the present invention, can proofread and correct emitted dose according to the correction data of reading from record head.This process can be finished during assembly manipulation automatically.Therefore, can save the correction of not wishing the change gamma that carries out.Under the situation of HC hard copy head, be equal to the body assembly of ink jet recording equipment its service life.So,, to change a record head or a plurality of record head usually if emitted dose changes during use.Adjust again according to this embodiment of the present invention and to be easy to finish.

As previously mentioned, according to this embodiment of the present invention, in being applicable to the ink jet recording equipment of replaceable record head, record head is provided with the information transfer device of a kind of form or another kind of form.The body assembly of tape deck receives information and according to this information, changes the indication or the form that are used for branch pulse width modulated driving method from the information transfer device of record head, thereby changes preheat pulse width P1.Thus, it is even from the emitted dose that makes record head to change the emitted dose of record head.So, can avoid because the variation of the emitted dose of inevitable each record head that is produced in the manufacture process.In addition, can eliminate the variation of the emitted dose of each record head, can avoid thus in the full-colour image forming process, owing to aberration or color reprodubility decline that the interference of color balance produces, therefore, image quality is improved.In addition, the change of control performance can improve the repeatability of chromatic image halftoning effectively.For monochrome image such as black, redness, blueness, green or the like, variable density can be eliminated.Utilize the method for present embodiment, usually because of the too big or too little discarded record head of emitted dose also can use, the output of record head can significantly improve thus, so the cost of record head can reduce.

Embodiment 3

What will describe here is, reduces on the jet exit that uses in record the method owing to the variation of the ink jet amount that caused by Effect on Temperature Distribution.The main control of the ink jet recording equipment of present embodiment and initial mounting board inspection are identical with embodiment's 2, and operational flowchart such as Figure 23, shown in 24,25,26 and 27.Main control is identical withsecond embodiment 2 basically, therefore here for just no longer having described for simplicity.

The recording equipment of present embodiment is applicable to the detachable record head (print cartridge type) in the previous embodiment.Similarly, record head drives by dividing pulse width modulated (PWM) driving method.Similar to previous embodiment, because the emitted dose that variations in temperature causes changes, outlet is provided with a plurality of jet heaters and temperature sensor to the ink jet record head that present embodiment adopts corresponding to ink jet in order to proofread and correct.Figure 36 has represented the heater plates HB of the record head that uses in the present embodiment.Dispose temperature sensor 8e on the plate base in the relation of illustrated position, auxiliary heater 8d has jet 8g and the driving element 8h of injection (mainly) heater 8c.By these elements are set, can detect and control the temperature of record head effectively on same substrate.In addition, can also reduce the size and the simplification production stage of record head.In this figure, represented in the zone that prepared Chinese ink is housed and the position relation of being unkitted the outward flange sidewall profile 8f of dividing top board between the zone of prepared Chinese ink.As shown in the drawing, temperature sensor 8e is arranged on the outside of outward flange sidewall 8f and towards jet exit on one side,, is arranged on zone that prepared Chinese ink is housed and near jet exit that is.By this layout, can detect the record head temperature adjacent effectively with jet exit.Similar with 2 to embodiment 1, temperature detection is to get the mean value of temperature sensor.That is, the temperature T H that records is (THL+THR)/2, and wherein THL and THR are by a left side and right two temperature that temperature sensor is measured.

When the left-half of the outlet of service recorder head nozzle ejection only, Temperature Distribution is shown in (2) among Figure 37.Along with this trend of raising of printing effect becomes more obvious.During printing, the temperature sensor in left side shows high temperature always, and the temperature sensor on right side shows low temperature always.When driving on the basis of the record head temperature T H that record head is so recording, its control is to realize on the temperature basis of the temperature T HL(THL of the nozzle that is lower than real work＞TH).Therefore, control operation has increased emitted dose, that is, control will make preheat pulse width P1 elongated.It would be desirable by control and reduce emitted dose, so control is unsettled.In addition, owing to, raise, the temperature on left side and right side is increased thereby produce temperature because of the increase of emitted dose with the preheat pulse width increases.

In order to eliminate vicious circle, the control in the present embodiment is to realize on the basis of Tc TH '=(XTHL+YTHR)/(X+Y), that is, and and with the temperature weighted on left side and right side.In the present embodiment, X=4 and Y=1 are in that half side nozzle carries out being placed into body assembly before the spraying by a left side.For example, if be THLMAX=40 ℃ and THRMAX=30 ℃ in the detected temperature of first row of the printing of 50% printing effect:

(1) under the situation of general control:

TH＝（40+30）/2＝35℃

Used as the basic point of control preheat pulse width P1, therefore the difference with THLMAX equals 5 ℃.

(2) in the present embodiment:

TH′＝（160+30）/5＝38℃

Used as the basic point of control preheat pulse width P1, therefore the difference with THLMAX is 2 ℃, has reduced the difference with actual temperature thus, has realized that more accurate record head drives control.

Another example of present embodiment is described below.In this example, the correction of record head temperature is implemented in record head driving process.This example is described in conjunction with monochrome printers.

In this routine equipment, left side and the right side temperature of using the mean value (THL=[THLM-2+THLN-1+THLN]/3) of three left side temperature sensors outputs and three right side temperature sensor outputs to control record head during print job are controlled auxiliary heater.Detect owing to use the temperature difference that the quantity of nozzle and position cause and that detected by left side and right side temperature sensor, and carry out energy control to eliminate the Temperature Distribution that produces waiting for during the auxiliary heater energize.

When only using the left side nozzle, the record head Temperature Distribution is shown in curve among Figure 37 (2).Along with the raising of printing effect, this trend becomes more obvious.The left side temperature sensor always shows high temperature during printing, and the right side temperature sensor then always shows low temperature.Consider the record head temperature difference TH that record detects, can drive auxiliary heater.Discern so exactly consider the record head temperature T HL that record head temperature difference TH reply detects in the left side of nozzle ink jet, and select a low target temperature to reduce the energy of auxiliary heater.On the other hand, consider that record head temperature difference TH reply discerns at the right side of not ink-jet of nozzle record head temperature T HR, and select a high target temperature to improve energy.Thus, can reduce the temperature difference in right side and left side.

In the method, considered the temperature difference between left side and the right side temperature sensor output signal, in energy control, with the energy weighting of left side and the supply of right side auxiliary heater.Only suppose to carry out at the left half side nozzle of record head and spray, the temperature of record head is 35 ℃ before beginning to print, and printing effect is 50%.Further temperature T HLMAX=45 ℃ and THRMAX=35 ℃ of hypothesis first print line detection.So, Δ TH=THLMAX-THRMAX=10 ℃.

(1) in general control,

THL=35 ℃ of left side target temperature

Right side target temperature THL=35 ℃

So the control system degree does not change target temperature.

(2) in the present embodiment,

TH/2=30 ℃ of left side target temperature THL=TH-Δ

TH/2=40 ℃ of right side target temperature THR=TH-Δ

Target temperature changes being different under the situation of actual temperature, therefore, control to reduce the temperature difference between right side and the left part.Still in the method, for temperature difference TH, body assembly has a form or a plurality of form of used nozzle quantity and position.

A kind of color copy machine of present embodiment is described below.

Under the situation of color copy machine, the picture intelligence of supplying with according to visual reader drives printer, and therefore, the relation between print range and the record head print span is the integral multiple of print span always not.Correspondingly, on the bottom line of printing, only used a part of nozzle.In a continuous printing type ink jet recording equipment, adopt standard paper supply (record head width) to stablize the paper supply precision.Therefore, if change paper feeding, just the paper feeding precision can reduce because of the appearance that connects colour band (image disturbs) for reducing to print.Based on this point, it is highly effective taking two-way to print, and promptly transmits on the paper at one and finishes twice printing.In this case, need to change the quantity of main jet.For example, reduce by 50% main jet, 64 nozzles on left side and right side are used by turns to realize the two-way printing.

In this example, based on the temperature difference Δ TH between left side and the right side temperature sensor, for example, for each group, can in control procedure, change driving pulse.In this equipment, the mean value of three left side sensor output signals and three right sensor output signals (THL=[THLM-2+THLN-1+THLN]/3) be used as and control the record head temperature T H that record head drives.Detect owing to the position of the nozzle that uses and the temperature difference that number causes, and make the driving pulse weighting that puts on the record head to reduce the temperature difference.

Only when using left half side nozzle, the Temperature Distribution of record head is shown in Figure 37 curve (2) (printing).Along with this trend of the raising of printing effect is more obvious.During printing, a total high-temperature, the low temperature of the total demonstration of right side temperature sensor of showing of left side temperature sensor.Record head drives according to record head temperature difference TH.More particularly, the pulse of supplying with the record head driving pulse PIL of injection nozzle (left side) is that short pulse is to reduce emitted dose, and the driving pulse PIR that supplies with non-injection nozzle (right-hand part) has very big width with increase emitted dose (raising temperature), thereby the emitted dose of making (temperature) is more evenly distributed.When only starting right half side nozzle, carry out similar operating process.

In the method, be weighted when controlling energy by the temperature gap of left side and the detection of right side temperature sensor and the driving pulse of each group.Suppose to start left half side nozzle with the driving pulse of P1=1.87 microsecond, and temperature be begin under TH=25 ℃ the operation.Further the hypothesis printing effect is that the temperature that 50%, the first row records is THLMAX=45 ° and THRMAX=35 °.So, Δ TH=(THLMAX-THRMAX)=10 °.

(1) under the general control situation,

Left side preheat pulse width PIL=P1 microsecond,

Right side preheat pulse width PIL=P1 microsecond,

Therefore, control system is not worked, that is, control system provides pulse width PI.

(2) in the present embodiment,

ΔP1＝P1·ΔTH/20℃，

Left side preheat pulse width PIL=(P1-Δ P1) microsecond, and right side preheat pulse width PIR=(P1+ Δ P1) microsecond, thus differently like this reduced the poor of emitted dose with the driving parameter on right side.In other words, control is finished with (P1 ± Δ P1).

When temperature difference TH was equal to or greater than 20 ℃, control operation can't be carried out, thereby produced rub-out signal.In the present embodiment, provide preheat pulse to improve its temperature to non-injection nozzle, still, in control and do not require preheat pulse is supplied with non-injection nozzle.

According to present embodiment, in using the ink jet recording device of heat energy, drive parameter or condition (temperature-controlled process, driving pulse etc.) and be according to the number change of nozzle, therefore, the Temperature Distribution of record head is more even, so emitted dose is more evenly distributed.Thereby can avoid the even or connection colour band of density unevenness.Even in end line printing or dwindle in the printing, also can keep the stable of density of image and/or color balance.

Embodiment 4

The fourth embodiment of the present invention adopts divides pulse width modulated (PWM) driving method.

In the present embodiment, the waveform that constitutes led signal quantity in a plurality of signals that drive signal by modulation is controlled at the speed of expansion of the bubble that produces in the prepared Chinese ink, can control jet speed thus, in addition, can carry out best prepared Chinese ink and recharge.The ink jet recording equipment of Shi Yonging is identical with first embodiment shown in Fig. 1-5 with the PWM driving method in the present embodiment.Briefly, first pulse of a minute pulse (the driving signal that is used for heat generating element) is modulated to stablize emitted dose as described in above-mentioned Fig. 1-5.On the other hand, the temperature of record head is controlled effectively.The controlled range of record head temperature is bigger, TO-TC as shown in Figure 8.

Relation between ink jet speed and the prepared Chinese ink temperature usually as shown in figure 38.More precisely, jet velocity increases with the increase of temperature.After reaching a certain temperature, jet velocity is linear increasing with the increase of prepared Chinese ink temperature.Relation between prepared Chinese ink temperature and the jet velocity is as described below.

Jet velocity V_{Prepared Chinese ink}, emitted dose M_{Prepared Chinese ink}Bubble volume Vb with the heat energy that provides by heat generating element produces in prepared Chinese ink, satisfy:

V prepared Chinese ink=K(2Vb/2t)/M prepared Chinese ink

Wherein K is a constant, and 2/2t is the director of time.

As previously described, jet velocity is directly proportional with air bubble expansion speed, is inversely proportional to emitted dose.So if for example emitted dose reduces and/or the gas vacuole speed of expansion increases, jet velocity then increases.Because can produce density of image heterogeneity or analogue, emitted dose (variation) minimizing is disadvantageous, as described in conjunction with Fig. 1-11, therefore, will control to stablize emitted dose usually.For these reasons, ink jet speed is determined by air bubble expansion speed continually.And air bubble expansion speed depends on prepared Chinese ink temperature (record head temperature).

Figure 39 represents the relation between bubble generation time t and the bubble volume Vb.On behalf of the record head temperature, curve a and b be respectively 25 ℃ respectively is non-situation when separating individual pulse with 40 ℃, driving pulse.Can know that thus when the volume Vb of bubble increased (expansion), because curve b has higher record head temperature, so slope of a curve, promptly speed of expansion was higher.

As previously mentioned, omitted relation shown in Figure 38, that is, jet velocity increases with the record head temperature, and the record head temperature refers to the prepared Chinese ink temperature in prepared Chinese ink path or shared print cartridge.

Though jet velocity can increase by improving the record head temperature, the bubble volume Vb of underspeed (contraction speed) is then less relatively, and therefore, the bubble collapse time in having the curve b of higher jet velocity is longer relatively.Consequently, cause the frequency that recharges of the problems referred to above to reduce.

These phenomenons can explain that promptly owing to the temperature of prepared Chinese ink around the bubble is higher, curve b has the long bubble collapse time by this factor.

Therefore, in the present embodiment, improve the prepared Chinese ink temperature be included in the injection, make record head remain on low temperature simultaneously, i.e. the prepared Chinese ink temperature around the bubble during bubble shrinkage to improve jet velocity.

Figure 40 has represented to drive the pulse of heat generating element and the bubble volume relation between changing in time.In this figure, when individual pulse A put on heat generating element, heat generating element temperature and bubble volume t in time changed.More particularly, driving pulse begins in time point tp rising and in the boiling of tas ' upper film, thereby makes bubble begin to expand.At time t₂The time, driving pulse descends, but bubble volume continues to increase to the tamax(maximum volume).Subsequently, bubble begins to shrink until disappearing at time taf.When applying dipulse B, bubble volume changes in a similar manner.

Competitive list pulse A is in bubble collapse cycle under the situation at dipulse B place (from the largest air bubbles volume to disappearing) and expansion period (from beginning to be expanded to maximum volume).Suppose that the bubble collapse time is basic identical, the expansion period under the dipulse B situation is shorter.That is, speed of expansion is higher.Can understand this point by curve a among the comparison diagram B and c.

Therefore, even the bubble collapse time is identical, jet velocity also can increase by applying dipulse.This is because the prepared Chinese ink temperature is that first by dipulse strengthens to the influence of spraying.Thus, reduce the resistance that the viscosity because of prepared Chinese ink causes, can improve air bubble expansion speed ink jet.Thereby raising jet velocity.In addition, by modulating the first pulse width P1, jet velocity is controlled.

When heat generating element was driven by dipulse, as described in conjunction with Fig. 1-15, the record head temperature was more easy to control relatively.Therefore, can reduce the record head temperature, thereby shorten the bubble collapse time, simultaneously, make the ink jet amount stable.

To be described in below under the situation of dipulse (branch pulse), consider the visual formation condition on record head drive condition and the recording materials, to the best setting of bubble width.

1) at first, processing signals P1, P2 and P3.Usually, think that simply dipulse is the combination of pulse P1 and P3.And do not consider interpulse interval P1.Know that by P1 at interval suitably is set, the heat by pulse P1 supplies with can fully influence bubble by pulse P3 and generate in the variation of heat P1.

In the present embodiment, considered this point, and made interval P2 apply cycle P1, made pulse apply near the colourity of cycle P1 thus and enlarge more than or equal to pulse, thus the condition of satisfying the demand effectively.In addition, cycle P2 preferably satisfies P2＜P3, thereby obtains effective ink droplet under the driving frequency of equipment.

In view of the above, in the equipment of control preheat pulse P1, need satisfy P1≤P2≤P3.Under the situation of dipulse, when utilizing heat energy to produce bubble, the people who knows specialty knows that laser intensity and its impedance of heat generation resistance more or less are restricted.More particularly, voltage is 15-30V.Above-mentioned condition P1≤P2＜P3 is effective especially in this scope.At a high-frequency region, for example be not less than 5KHz, preferably be not more than 8KHz and the maximum drive frequency preferably is no less than 10KHz, this condition is effective especially.

For pulsewidth P3, generate this angle from stable bubble, 1 microsecond≤P3≤5 microseconds are more suitable.In this scope, above-mentioned condition P1≤P2＜P3 is highly effective.

2) below will the emitted dose on the recording materials be described.

Ink jet amount Vd(PL/dpt) determine to be based on (consideration area factor) on the recording materials, PEL density and prepared Chinese ink fly out speed.For example, in order to make the PEL density record of whole image, need about 8nl/mm with 400dpi²Ink jet.For by spraying once or several times this amount of acquisition, emitted dose Vd is 5-50(Pt/dot).

In axial equipment, pulse width P1 changes, and provides above-mentioned emitted dose Vd when satisfying above-mentioned condition P1≤P2＜P3 with box lunch, can select drive condition to satisfy the needs of recording materials and recording method thus at an easy rate.

3) maximum magnitude of driving frequency is described below.Driving frequency f(KHz) according to writing speed with recharge feature and determine.But, if emitted dose is according to above-mentioned paragraph 1) select, correspondingly, driving frequency is also determined thus.More particularly, if emitted dose is little, driving frequency is higher, and on the contrary, if emitted dose is big, driving frequency is then high, and the result is that if consider scope Vd=5-50 is provided, then driving frequency f is 2-20KHz.

4) below with description group section drive system, wherein the jet exit quantity of record head is n_N, and jet exit is divided into n_BIndividual successively with some group section N_SectionThe group section that (quantity of the quantity of jet exit/group section) drives.

Here, the pulse width Pd of dipulse is defined as Pd=P1+P2+P3.So, the maximum Pd of pulse width is T/n in theory_B, wherein T is a drive cycle.But, if pulse Pd is chosen as T/n_B, owing to may produce unnecessary bubble in prepared Chinese ink, electrical interference may take place.Or need transistor cycle conversion time that is used to the conversion of the section of group.Therefore, need an off period in the intersegmental pulse of group.If the time cycle is α, the time that then is used to apply the dipulse needs is Pn=pd+ α.

Therefore, in condition 1)-5) situation under, width Pn maximum (Pn) max is (Pn) max=Tn_B=1/(n_BAnd Pd＜1/(n f),_BF).For example, in condition 3) situation under, 2≤5≤20, and therefore as driving frequency Pd＜(2n during in this scope_B).Suppose that a group section comprises 8 jet exits, so, if jet exit n_NQuantity be respectively 64,128 or 256, number n then_BBe respectively 8,16 or 32.If divide to drive and not carry out, so no matter the quantity of jet exit how, n_B=1.Thus, for example, if n_B=8, Pd＜1/(2 * 8 so) millisecond, that is, and 6.25 microseconds＜Pd in above-mentioned driving frequency scope＜62.5 microseconds.

If 5≤f(≤20 similarly), Pd＜1/(5n so_B); If 8＜f(≤20), Pd＜1(8n so_B); And if 10≤f(≤20), Pd＜1/(10n so_B).

Satisfy Pd=P1+P2+P3＜1/(n_BF) pulse or interval width P1, P2 is relevant with following condition with P3:

1) no matter how little pulse width P1 is, width P3 needs enough greatly to produce bubble;

2) rely on pulse P1 separately, the maximum of width P1 is not enough to produce bubble; And

3) P2 should be long as much as possible at interval, but be no more than (Pn) max.

To describe an example of ink jet recording equipment below, and wherein introduce the control of aforementioned jet velocity, in this control, the distance between record head and the recording materials is that the material with recording materials changes.

For example, when using art paper, the distance between record head and the recording materials can shorten relatively.But common paper or OHP paper for the ink absorption ability difference then need a bigger distance, because can be because wrinkling or bubble than being easier to take place direct contact between record head and the recording medium.Based on this point, for art paper, be set to 0.7 millimeter, and jet velocity is set to 12 meter per seconds; For common paper or similar paper, paper be set to 1.2 millimeters, and jet velocity is set to 16 meter per seconds.

By the record head temperature is set, and the first of modulation dipulse can finish the control of this jet velocity in conjunction with the control of the described record head temperature of Fig. 1-15 in utilization.

As previously mentioned, when the distance between record head and the recording materials is big,, can avoid the deviation of droplet deposition position, avoid the deterioration of accuracy of spray thus by increasing jet velocity.

To an example of the monochrome printers relevant with present embodiment be described below.

In this printer, use a kind of replaceable record head that is removably mounted on this printer.Therefore, the record head that need be suitable for installing according to settings such as printer service condition that record head is housed on it recharges frequency.In monochrome printers, relatively low recharge the printer (low speed printer) that frequency will satisfy relatively low driving frequency.Therefore, the record head temperature no longer reduces, and jet velocity can be controlled by the pulse width modulation in the dipulse.

Can know that from noted earlier according to this embodiment of the present invention, the leading part waveform of a plurality of signals is modulated, the speed of expansion of bubble can be controlled in the prepared Chinese ink thus, thereby has controlled the jet velocity of prepared Chinese ink.In addition, by the modulation of leading part, can the injected prepared Chinese ink temperature of local control.Thus, when bubble shrinkage, the temperature of prepared Chinese ink around the bubble, irrelevant, optionally lower with jet velocity and emitted dose or other factors control.Consequently, can increase the contraction speed of bubble, recharge frequency thereby improve.

Embodiment 5

The 5th embodiment is described below, and it uses above-mentioned branch pulse width modulated (PWM) driving method.In the PWM driving method, constitute the driving signal by a plurality of component of signals, and the waveform of preceding component is modulated with the control emitted dose.

In the present embodiment, use PWM driving method is controlled at the packing density on elevated projecting (OHP) paper.Under the situation of using OHP paper record, image can be perfectly clear when carrying out projection, therefore, wishes to use high density recording.By controlling emitted dose according to record head temperature simple modulation pulse width, can not provide the packing density of desirable relative higher density, particularly on OHP paper.

Describe below with reference to accompanying drawing.The structure of employed in the present embodiment ink jet recording equipment and PWM driving method, similar to described in first embodiment shown in Fig. 1-15.In brief, can stablize the first pulse component that the driving signal that is used for heat energy generating device and emitted dose divides pulse.On the other hand, can also effectively control the temperature of record head.In addition, as shown in Figure 8, record head temperature controlling scope bigger (TO-TL).

When on OHP paper, implementing to print, need to proofread and correct the variation of emitted dose, but also need record to have high density usually.Therefore, when on OHP paper, implementing to print, and carry out PWM not according to the record head temperature and control, and pulse width P1 is fixed on the maximum possible level, realize high density recording thereby increased emitted dose thus.

Figure 41 is the calcspar of explanation according to the record head driving control of one embodiment of the present of invention, and Figure 42 is the various signal time-base diagram shapes that are used for this structure.

The figure of record head drive signal waveform is stored among the ROM805 in advance.Drive the signal output time at record head, clock pulses is supplied to the counter 800C in the controller shown in Figure 15 800.When providing pulse signal, the output of counter increases by 1 at every turn.Thus, the internal memory among the ROM803 follows the counter output as address signal to be output as record head driving signal.

It is to export on the basis of selecting from the PWM control table of the pulse width of storing each temperature prepulsing P1 that record head drives signal.As shown in figure 42, produced the record head driving signal that has according to the waveform of select table.The selection that record head drives the signal form is decided by that the PWM that supplies with ROM803 controls form selection signal.When OHP paper selects signal be " H ", all input ROM803's, the input signal of selecting signal as the PWM form all becomes " H " by the operation of OR-gate 800A, so that the selection of form AN+X-1 has nothing to do with PWM form selection signal.Thus, prepulsing width P1 is fixed on its maximum as shown in figure 42, specifically, and P1=2.618 microsecond, and P3=4.114 microsecond.

Figure 42 has represented the driving signal of record head when printing ON signal is printed for the execution of " H ".When printing ON signal was " L ", the record head among Figure 42 drove signal relevant with pulse P3 " L " level.

In the present embodiment, only when preheat pulse P1 is arranged on its maximum level emitted dose be only increase.Can further increase emitted dose by increasing the record head temperature.More particularly, the target temperature of record head control increases to 40 ℃ from common 25 ℃.Because because of the temperature rising that printing causes may be near 15 ℃.If further increasing the record head temperature, temperature can reach capacity temperature T LIMIT=60 ℃.

When the material according to recording materials detects identification OHP pattern, by mode transitions is finished above-mentioned driving control to the OHP pattern.In the present embodiment, by the agency of the PWM control of prepulsing of pulse in relevant minute.Under the PWM of individual pulse control situation, in the OHP pattern, can use fixed pulse to increase emitted dose.In addition, can add said temperature control changes.

With reference to Figure 43 and 44, will another embodiment that record head drives control be described.In Figure 43, the picture intelligence of print data form is stored among the RAM805.Be stored at picture intelligence on the time point of RAM805,CPU 800 is sent pictorial data intoshift register 800R, and produces record head driving item.Flow chart with reference to Figure 44 describes in detail below.

In Figure 44, at step S1,CPU 800 is read the one or more pictorial data that are used for a pixel fromrandom access machine 805, and operation sequence goes to step S2, discern in these one or more data that action is printed in expression, i.e. whether identification has ink jet.If prepared Chinese ink is injected, operating procedure proceeds to step S3.If prepared Chinese ink is not injected, execution in step S9 then.In step S3, theregister 12 ofCPU 800 is stored main pulse P₃Cycle " H ", and operating procedure proceeds to step S4.In step S4, read in PWM and select signal, " H " level width of prepulsing P1 is stored in theregister 12 ofCPU 800, and operating procedure proceeds to S5, reads in OHP at this and selects signal.If this signal indication OHP paper printing model, operating procedure enters step S6, if S7 is then carried out in not indication.

In step S6, the H level width of the preheat pulse P1 that determines in step S4 change to selectable Breadth Maximum, and is stored in the register of CPU 800.Subsequently, step S7 is carried out in operation, utilize the information of prepulsing P1 and the information of main pulse P3 to produce record head driving signal in this step, and this signal is stored among the shift register 800R.Subsequently, execution in step S8, the record head driving signal and the clock that wherein are stored among theshift register 800R produce fromtranslation register 800R synchronously.

In step S8, will for be stored among the RAM805 pictorial data whether all output discern.If, EO.If not, step S1 is then got back in operation.Fig. 9 has represented the driving pulse the selected fluctuation in the said PWM control.

When the recording materials that use were common recording materials rather than transparent recording materials such as OHP paper, PWM control was selected waveform 1-11 among Fig. 9 according to detected temperatures etc.

When at the enterprising line item of OHP paper, only with the pulse shown in 1 among Fig. 9.

When using OHP paper, modification as these embodiment, a kind of driving pulse can be fixed in employed pulse, and can select to have in the preheat pulse among Fig. 9 the pulse of relatively large width, and PWM is controlled at interior enforcement of scope of selected relatively large pulse.Thus, particularly when the record full-colour image, can produce high density of image and follow high picture quality.

For example,, the pulse shown in the 1-4 among Fig. 9 is arranged, the pulse among Fig. 9 shown in the 1-2, and the pulse shown in 1 and have the combination of one or more pulses of big preheat pulse width P1 among Fig. 9 for the selectable range of pulse.

Can know by aforementioned, according to the present invention, the recording materials that have a transparent part when use (for example, OHP paper) time, can produce a kind of signal and select a kind of logging mode with indication, in this pattern waveform modulated be one with finish in common recording materials are compared the scope with higher temperature region.Corresponding, for example, driving control device is with dividing the modulation of pulse driving method control preheat pulse, so that finish modulation in the bigger predetermined scope of pulse width, described pulse width is the same with the mode select signal that is produced long.Record head drives signal can have the width that is fixed on the preheat pulse in this scope.

The result is, the ink jet amount can increase emitted dose by pulsewidth being fixed in the higher drive condition scope with big pulsewidth and it being fixed on certain point of this scope.Therefore, the high density of image that can be implemented in OHP paper or the similar paper is printed.

In the above-described embodiments, according to the output of temperature sensor control with stablize emitted dose.But the present invention is not limited to this a kind of situation, and it also can be used for another kind of situation, and wherein emitted dose is that the carrier chrominance signal of measuring point tone as indicated changes.According to the variations in temperature that sensor detects, emitted dose can change to obtain stablizing in the wide region according to tonal signaling.

The present invention is specially adapted to ink jet record head and recording equipment, and wherein by electrothermal transducer, thereby the heat energy of generations such as laser beam is used to make the state of prepared Chinese ink to change to be sprayed or drain prepared Chinese ink.This is because the present invention can realize the high density of pixel and the high-resolution of record.

Typical structure and operating principle are preferably disclosed referring to No. 4723129, United States Patent (USP) and No. 4740796.Principle and structure can adopt so-called demand type register system and continuous type register system.But demand type is more suitable, because principle is such, promptly, drive signal to one of major general and supply with an electrothermal transducer that is arranged on liquid (prepared Chinese ink) washer or the fluid path, this driving signal is enough to produce a rapid warm raising that surpasses the nuclear boiling point, provide heat energy so that produce film boiling by electrothermal transducer at the heating part of record head, thus in liquid (prepared Chinese ink) corresponding each drive signal and form bubble.By the generation of bubble, development and contraction, liquid (prepared Chinese ink) sprays to produce at least one drop by jet exit.Drive signal and be preferably impulse form, finish because it can make the development of bubble and be contracted in moment, thus, liquid (prepared Chinese ink) is by response is injected fast.The driving signal of pulse shaping is the sort of disclosed in the United States Patent (USP) No. 4463359 and No. 4345262 preferably.In addition, the specific temperature rise of the area of heating surface preferably adopts disclosed in No. the 4313124th, the United States Patent (USP).

The structure of record head can adopt shown in the United States Patent (USP) No. 4558333 and No. 4459600, and wherein heater block is arranged on the combining structure of the described bending part of above-mentioned patent and jet exit fluid path and electrothermal transducer.In addition, the present invention also can adopt the structure disclosed in No. the 123670/1984th, the Japanese Laid-Open Patent Application, and one of them common recess is used as the jet exit of a plurality of electrothermal transducers; With adopt the structure disclosed in No. the 138461/1984th, the Japanese Laid-Open Patent Application, wherein form an opening in order to absorb the pressure wave of heat energy corresponding to injection component.This is because why the present invention still can be natch regardless of the type of record head and finished record efficiently and operate.

The present invention is applicable to so-called complete capable type record head, and this record head has the length corresponding to the dominant record width.This kind record head comprises that the combination of a unirecord head and a plurality of record heads is to cover Breadth Maximum.

In addition, the present invention is also applicable to the continuous type record head, and wherein record head is fixed on the body assembly, also is applicable to replaceable chip-shaped record head, and this record head is electrically connected with main equipment and can supplies prepared Chinese ink to it when it is contained on the body assembly; Or adopting print cartridge type record head, it has the prepared Chinese ink reservoir of an integral body.

Preferably be equipped with return mechanism and/or the servicing unit that is used for initial operation, because they can further stablize effect of the present invention, in these devices, be useful on the lid shape device and the cleaning device of record head, press or the suction device, can be used as the preheating apparatus of electrothermal transducer, additional heating element heater or their assembly.In addition, be used to carry out the device energy stable recording operation of pilot injection (being not used in the record operation).

For the variation of installable record head, it can be the single record head with respect to monochromatic prepared Chinese ink, or with respect to a plurality of record heads of the multiple prepared Chinese ink material with different recording color or density.The present invention is specially adapted to have at least a monochromatic mode, is mainly black; With the polychrome pattern with different colours prepared Chinese ink material and/or use the equipment of the panchromatic mode of blend color, it can be the assembly of integrally formed record cell or a plurality of record heads.

In addition, in the aforementioned embodiment, prepared Chinese ink is liquid.Yet it also can be a kind of curing when being lower than room temperature and the prepared Chinese ink material that liquefies when room temperature.Because being controlled in, prepared Chinese ink is not less than 30 ℃ and be not higher than in 70 ℃ the temperature range to stablize the viscosity of prepared Chinese ink, thereby for the common recording equipment of the type provides a kind of stable injection, like this, when tracer signal of the present invention is applicable to other prepared Chinese ink type, in this temperature range, prepared Chinese ink is liquid.A kind of in these prepared Chinese ink is because of it is transformed into temperature that the liquid heat energy that state variation consumed causes and raises and should definitely avoid from solid-state.Another kind of prepared Chinese ink material is solid-state when it remains, to prevent the prepared Chinese ink evaporation.No matter the sort of situation all produces heat energy when tracer signal is provided, make prepared Chinese ink liquefaction, the prepared Chinese ink of liquefaction can be injected, and another kind of prepared Chinese ink material begins to solidify when it arrives on the recording materials.The present invention is also applicable to a kind of like this prepared Chinese ink material, and is liquefied by applying heat energy.This prepared Chinese ink material can the liquid or solid material be kept at the nearly hole or the indent of porous plate, disclosed in Japanese Laid-Open Patent Application No. 56847/1979 and No. 71260/1985.This plate is towards electrothermal transducer.For above-mentioned prepared Chinese ink material film boiling system the most effectively.

The ink jet recording equipment can be used as the outlet terminal of messaging device such as computer etc., also can with combination such as visual reader as a kind of copier, or as having information sends and the facsimile machine of receiving function.

When present invention is described with reference to disclosed structure here, be not limited in aforesaid these details, and the application will comprise such some changes or variation, its objective is in order to improve or satisfy the scope of following claim.

Claims (29)

1, a kind of ink jet recording device wherein puts on the heat energy that the driving signal on the heater produces by response and produce bubble in prepared Chinese ink, and the expansion by bubble with ink jet to recording materials, this equipment comprises:

Drive unit, it applies a plurality of driving signals for each ink droplet jet to described heater, wherein drive signal and comprise that one first driving signal is used near the prepared Chinese ink temperature raising heater under the situation that does not produce bubble, with the second driving signal, this signal is after first drives signal and an interval is arranged with it, is used to spray prepared Chinese ink;

It is characterized in that providing conversion equipment to be used to change first width that drives signal, wherein, be not shorter than 2.6 microseconds at interval, and second width that drives signal keeps constant to regulate ink ejection amount.

2,, it is characterized in that the wherein said first and second driving signals have identical amplitude according to the equipment of claim 1.

3,, it is characterized in that wherein first width that drives signal is shorter than second width that drives signal according to the equipment of claim 1.

4, according to the equipment of claim 1, it is characterized in that also comprising the checkout gear of a detection record temperature, wherein first width that drives signal is that output according to described checkout gear changes.

5, according to the equipment of claim 1, it is characterized in that also comprising that the user produces the device of tonal gradation signal, wherein first width that drives signal is the tonal gradation signal controlling that produces by described tonal gradation signal generation apparatus.

6, a kind of ink jet recording method, wherein put on heat energy that the driving signal of heater produces at prepared Chinese ink water generates bubble by response, and the expansion by bubble makes ink jet to recording materials, wherein each drop for prepared Chinese ink sprays, a plurality of driving signals are put on the heater, and the step that this method comprises has:

The first driving signal that can improve near the prepared Chinese ink temperature of heater effectively is provided;

Off period after providing one to apply the first driving signal;

Provide and in prepared Chinese ink, to produce bubble effectively to spray the second driving signal of prepared Chinese ink; With

It is characterized in that providing first change that drives the deration of signal to regulate ink ejection amount, wherein be shorter than 2.6 microseconds off period, and second width that drives signal keeps constant.

7,, it is characterized in that the described first and second driving signals have identical amplitude according to the method for claim 6.

8,, it is characterized in that its first width that drives signal is shorter than the width of the second driving signal according to the method for claim 6.

9, according to the method for claim 6, it is characterized in that also comprising the temperature that detects described record head, wherein first drive the width of signal by in described switch process, changing by the temperature that detects the step detection.

10,, it is characterized in that also comprising producing the tonal gradation signal that wherein said switch process changes the width of the first driving signal according to the tonal gradation signal according to the method for claim 6.

11, a kind of ink jet recording device wherein puts on the heat energy that the driving signal on the heater produces by response and produce bubble in prepared Chinese ink, and by the expansion of bubble prepared Chinese ink is sprayed onto on the recording materials, and this equipment comprises:

Drive unit, it applies the driving signal of a plurality of drive cycles to described heater for each ink droplet jet, wherein drive cycle comprises one first drive cycle, temperature with near predefined voltage prepared Chinese ink raising heater under the situation that does not produce bubble, comprise that also one second drive cycle is used for setting in advance the voltage ink-jet with same, this second drive cycle is after first drive cycle and have one with it at interval;

It is characterized in that providing first change that drives the deration of signal to regulate ink ejection amount, it is not shorter than 2.6 microseconds at interval, and the second drive cycle width keeps constant.

12,, it is characterized in that the width of its first drive cycle is shorter than the width of the second driving signal according to the equipment of claim 11.

13, according to the equipment of claim 11, it is characterized in that also comprising the checkout gear of a detection record temperature, wherein the width of first drive cycle changes by the output of described checkout gear.

14, according to the equipment of claim 11, it is characterized in that also comprising the device that produces the tonal gradation signal, wherein the width of first drive cycle is according to the tonal gradation signal controlling of described tonal gradation signal generation apparatus generation.

15, a kind of spray put equipment wherein puts on the heat energy that the driving signal on the heater produces by response and produce bubble in prepared Chinese ink, and by the expansion of bubble prepared Chinese ink is sprayed onto on the recording materials, and this equipment comprises:

Drive unit, it applies a plurality of driving signals for each ink droplet jet to described heater, wherein drive signal and comprise that one first driving signal is used in the temperature that does not have near the prepared Chinese ink the raising heater under the situation of bubble, comprise that also one second driving signal is used for ink-jet, this second drives signal after first drives signal and have one with it at interval, and wherein the heat energy of the first driving signal is sent in the interval near the heater the prepared Chinese ink;

It is characterized in that providing conversion equipment to be used to change first and drive the width of signal to regulate ink ejection amount, wherein be not shorter than the width of the first driving signal at interval, even first width that drives signal also is so when being its maximum, and the second driving deration of signal is constant.

16,, it is characterized in that the wherein said first and second driving signals have identical amplitude according to the equipment of claim 15.

17,, it is characterized in that wherein first width that drives signal is shorter than second width that drives signal according to the equipment of claim 15.

18, according to the equipment of claim 15, it is characterized in that also comprising the checkout gear of a detection record temperature, wherein first width that drives signal changes by the output of described checkout gear.

19, according to the equipment of claim 15, it is characterized in that also comprising the device of tonal gradation signal, wherein first drive the width of signal by the tonal gradation signal controlling that produces by described tonal gradation signal generation apparatus.

20,, it is characterized in that its described second driving signal has the width that single record head is determined according to the equipment of claim 15.

21, a kind of ink jet recording method, wherein put on the heat energy that the driving signal on the heater produces and in prepared Chinese ink, produce bubble by response, and China ink is sprayed onto on the recording materials by the expansion of bubble, wherein each drop for prepared Chinese ink sprays, a plurality of driving signals are put on the heater, and the step that this method comprises has:

The first driving signal that can improve near the prepared Chinese ink temperature of heater effectively is provided;

Off period after providing one to apply the first driving signal, wherein first drive near the prepared Chinese ink of heat energy being sent to heater off period of signal;

Provide and in prepared Chinese ink, to produce bubble effectively to spray the second driving signal of prepared Chinese ink; With

It is characterized in that providing first change that drives the deration of signal regulating ink ejection amount, even also be not shorter than first width that drives signal when wherein first width that drives signal is its maximum at interval, and second to drive the deration of signal constant.

22,, it is characterized in that its described first and second driving signals have identical amplitude according to the method for claim 21.

23,, it is characterized in that its first width that drives signal is shorter than the width of the second driving signal according to the method for claim 21.

24, according to the method for claim 21, it is characterized in that also comprising the temperature that detects described record head, wherein first width that drives signal changes in described switch process by the temperature that detects the step detection.

25,, it is characterized in that also comprising and send the tonal gradation signal that wherein said switch process changes the width of the first driving signal by the tonal gradation signal according to the method for claim 21.

26,, it is characterized in that its described second driving signal has the width that single record head is determined according to the method for claim 21.

27,, it is characterized in that its described second driving signal has the width that single record head is determined according to the equipment of claim 1.

28,, it is characterized in that its described second driving signal has the width that single record head is determined according to the method for claim 6.

29,, it is characterized in that its described second drive cycle has the width that single record head is determined according to the equipment of claim 11.

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