CN100406254C - Inkjet recording device - Google Patents

Abstract

The present invention provides an inkjet recording device for forming an image on a recording medium with an inkjet recording head. The inkjet recording device is provided with a conveyance section and a switchback section. One face of the recording medium is adhered to the conveyance section and the conveyance section transports the recording medium to the inkjet recording head. An image is formed on the other face of the recording medium, and the recording medium is transferred to the switchback section from the conveyance section, with the one face of the recording medium being adhered to the switchback section. The switchback section feeds the recording medium back to the conveyance section such that the other face of the recording medium can be adhered to the conveyance section.

Description

Ink-jet recording apparatus

Technical field

The present invention relates to a kind of ink-jet recording apparatus, it sprays ink droplet to carry out the image record from ink jet print head to recording medium.

Background technology

Up to now, known such ink-jet recording apparatus, it is gone up and sprays ink droplet with document image at recording medium (for example, paper etc.) from the nozzle of ink jet print head.This ink-jet recording apparatus from the nozzle ejection ink droplet to be printed directly on the paper.Therefore, under the situation of duplex printing, be dried to a certain degree, print otherwise can not go up at another side (back side) up to a printing surface (front).Therefore, proposed to be used for the method for a dry described printing surface, for example temporarily paper has been discharged to (for example referring to Japanese Patent Application Laid-Open (JP-A) No.2000-1010) such as device outsides.

Yet, adopting the structure that temporarily paper is discharged to the device outside, paper transport path is longer, thereby makes efficient at duplex printing on single paper reduce (except ink setting the time, also being useful on the extra delivery time of duplex printing) inevitably.As a result, exist the problem that productivity ratio descends when a large amount of duplex printing.And in the paper turning path that is used for duplex printing, the previous face of printing is subjected to CONTACT WITH FRICTION, thereby may make the picture quality variation on this face.

Summary of the invention

Therefore, in view of said circumstances, the invention provides a kind of ink-jet recording apparatus, it can be avoided causing the picture quality variation owing to the friction of printing surface in duplex printing, and can prevent that productivity ratio from descending.

The ink-jet recording apparatus of first aspect present invention is the ink-jet recording apparatus that is used for forming on recording medium by ink jet print head image, and comprise: translator unit, the one side of recording medium is attached thereto, described translator unit is sent to ink jet print head with this recording medium, and described translator unit comprises the conveyer belt that twines around at least two rollers; And loopback part, another side has formed the record images medium and has been delivered to this loopback part from described translator unit, the described one side of described recording medium is attached on this loopback part, and this loopback part supplies to described translator unit with this recording medium once more, thereby make the another side of this recording medium can be attached on the translator unit, described loopback partly comprises the reverse band that twines around at least two rollers, described reverse band along with rotate in the direction of the direction of rotation of recording medium when conveyer belt transmits so that recording medium is sent to described conveyer belt.

According to first aspect, in duplex printing, still unprinted one side is partly adhered to and is kept in described loopback.Therefore, can prevent to cause the picture quality variation owing to the friction of printing surface.And, because can fast recording medium be supplied with translator unit once more, so can avoid the decline of productivity ratio when duplex printing by the loopback part.

The ink-jet recording apparatus of second aspect present invention is the ink-jet recording apparatus that is used for forming on recording medium by ink jet print head image, and comprise: translator unit, the one side of described recording medium is attached to it, this translator unit is sent to described ink jet print head with recording medium, and described translator unit comprises the conveyer belt that twines around at least two rollers; And loopback part, being formed with the record images medium on the another side is transmitted on this loopback part from described translator unit, the described one side of recording medium is attached on the described loopback part, and described loopback part supplies to described translator unit once more with recording medium, thereby make the described another side of recording medium can be attached on the translator unit, described loopback comprises that partly one oppositely rouses, and described ink-jet recording apparatus also comprises: first separating part, it separates recording medium from described conveyer belt, be used for recording medium is sent to reverse drum from conveyer belt; Second separating part, it separates recording medium from described reverse drum, be used for recording medium is sent to conveyer belt from reverse drum; And the 3rd separating part, it separates recording medium from described conveyer belt, so that discharge.

Description of drawings

To be elaborated to embodiments of the invention based on following accompanying drawing below, in the accompanying drawings:

Fig. 1 is the schematic side elevation that is presented at the structure of ink-jet recording apparatus in the print procedure;

Fig. 2 is the schematic side elevation that is presented at the structure of this ink-jet recording apparatus in the maintenance process;

Fig. 3 is for showing the schematic side elevation of first embodiment loopback structure partly, and it is provided with reverse band;

The schematic side elevation of the structure of first embodiment loopback part when Fig. 4 prints for being presented at single channel (single-pass) single face;

Fig. 5 is the schematic side elevation of the structure of first embodiment loopback part when being presented at the single channel duplex printing;

Fig. 6 A and 6B are the schematic side elevation of the structure of first embodiment loopback part when being presented at the single channel duplex printing;

Fig. 7 A, 7B, 7C and 7D are the schematic side elevation that is presented under the situation that transmits plurality of sheets of paper simultaneously the structure of first embodiment loopback part when the single channel duplex printing;

Fig. 8 A, 8B, 8C and 8D are the schematic side elevation of the loopback structure partly of first embodiment when being presented at the multichannel duplex printing;

Fig. 9 is for showing the schematic side elevation of second embodiment loopback structure partly, and it is provided with reverse band;

Figure 10 A, 10B and 10C are the schematic side elevation of the structure of second embodiment loopback part when being presented at the single channel duplex printing;

Figure 11 A, 11B and 11C are the schematic side elevation of the structure of second embodiment loopback part when being presented at the single channel duplex printing;

Figure 12 A, 12B and 12C are the schematic side elevation that is presented under the situation that transmits plurality of sheets of paper simultaneously the structure of second embodiment loopback part when the single channel duplex printing;

Figure 13 A, 13B and 13C are the schematic side elevation that is presented under the situation that transmits plurality of sheets of paper simultaneously the structure of second embodiment loopback part when the single channel duplex printing;

Figure 14 is for showing the schematic side elevation of the 3rd embodiment loopback structure partly, and it is provided with reverse band;

Figure 15 A, 15B and 15C are the schematic side elevation that is presented under the situation that transmits plurality of sheets of paper simultaneously the structure of the 3rd embodiment loopback part when the single channel duplex printing;

Figure 16 A, 16B and 16C are the schematic side elevation that is presented under the situation that transmits plurality of sheets of paper simultaneously the structure of the 3rd embodiment loopback part when the single channel duplex printing; And

Figure 17 A and 17B are for showing the schematic side elevation of the 4th embodiment loopback structure partly, and it is provided with reverse drum.

The specific embodiment

Below, will be that the basis describes the present invention with embodiment shown in the accompanying drawing.At first first embodiment will be described.The general structure that relates to ink-jet recording apparatus 10 of the present invention has been shown in Fig. 1 and 2.As illustrated in fig. 1 and 2, being characterized as of this ink-jet recording apparatus 10 comprisessheet feed stacker 12,recording section 14,translator unit 16 and paper discharge tray 18.Sheet feed stacker 12 is held paper P, and this paper is an example of recordingmedium.Recording section 14 is document image on the paper P that supplies with from sheet feed stacker 12.Translator unit 16 is delivered to recordingsection 14 with this paper P.Paper discharge tray 18 holds the paper P that has been write down image byrecording section 14 thereon.

Recording section 14 be characterized as ink jet print head 20.This inkjet print head 20 be characterized as a posting field, this posting field approximate match or surpass the possible Breadth Maximum of paper P by ink-jet recording apparatus 10 document images.In other words, this inkjet print head 20 has constituted " full width array " can single channel printed (FWA).

In inkjet print head 20, the order of black (K), cyan (C), carmetta (M) and yellow (Y) is swum side from it along the direction of transfer of paper P and is arranged, and is configured to spray ink droplet by known technology (for example, hot system, piezoelectric system etc.).For its printing ink, can adopt various printing ink, for example water-soluble China ink, oil-based ink, solvent based ink etc.Print cartridge 58K, 58C, 58M and 58Y are arranged in the ink-jet recording apparatus 10, are used for to inkjet print head 20K, 20C, 20M and 20Y supply printing ink.

Maintenance unit 22K to 22Y is located at inkjet print head 20K to 20Y and locates.Thismaintenance unit 22K to 22Y is divided into two groups: black (K) and cyan (C) and carmetta (M) and yellow (Y).Maintenance unit 22K to 22Y is configured to retracted position that can be when being used to print and is used for moving between the position of maintaining ink-jet record head 20K to 20Y.

Maintenance unit 22K to 22Y comprises pseudo-nozzle holder (dummy jet holder), erased element, cap or the like.When wanting maintaining ink-jet record head 20K to 20Y, 20K to 20Y is promoted to predetermined altitude with ink jet print head, and nozzle surface (not shown) with inkjet print head 20K to 20Y is relative respectivelymaintenance unit 22K to 22Y to be arranged to make then it.

Paper P in thesheet feed stacker 12 extracts one by pick-up roller 24 at every turn, and is supplied to recordingsection 14 by translator unit 16.Translator unit 16 comprises theconveyer belt 30 that the printing surface that is used to make paper P and inkjet print head 20 are relative.Thisconveyer belt 30 twines around driven roller 26 (it is arranged in the downstream of paper conveyance direction) and driven roll 28 (it is arranged in the upstream side of paper conveyance direction).Direction (clockwise direction) circulation thatconveyer belt 30 is configured to arrow A in the figure drives (rotation).

As shown in Figure 3, compression roller (nipping roller) 32 is arranged in the top of driven roll 28.Thiscompression roller 32 is driven byconveyer belt 30 by the front face side of conveyer belt 30.Charging roller 34 is arranged in the below of driven roll 28.Thischarging roller 34 is driven byconveyer belt 30 by the described front face side ofconveyer belt 30.

Conveyerbelt 30 is bycharging roller 34 chargings (applying electric charge thereon), so paper P is transmitted onconveyer belt 30 and by thisconveyer belt 30 by electrostatic adherence.Here, can be provided with such structure, whereincharging roller 34 contacts withconveyer belt 30 all the time and is driven byconveyer belt 30, also can be provided with such structure, wherein makescharging roller 34 move apartconveyer belt 30 when paper P passes throughcharging roller 34 at every turn.

At the place, bottom ofconveyer belt 30, promptly arrange the opposite side place of side at itself and inkjet print head 20,idler roller 36 is driven byconveyer belt 30 by the back side of conveyer belt 30.A pair of clearer 38 is arranged betweenidler roller 36 and the driven roller 26.This is made ofstationary roll 38A and oscillatingroller 38B clearer 38.Stationary roll 38A is driven byconveyer belt 30 by the back side of conveyer belt 30.Oscillatingroller 38B is driven byconveyer belt 30 by the front face side ofconveyer belt 30, and is configured to and can suitably separates fromconveyer belt 30.

Be arranged in the downstream ofidler roller 36 along the rotation direction ofconveyer belt 30 as first disengagingpawl 40 of first separating part.First disengagingpawl 40 can pivot on rotatingshaft 40A, and is configured to and can be used for the position ofconveyer belt 30 sliding-contacts with from rotating (swing) between the position thatconveyer belt 30 separates.

Be arranged in the downstream of drivenroller 26 along the rotation direction ofconveyer belt 30 as the 3rd disengagingpawl 42 of the 3rd separating part.Similar with first disengagingpawl 40, the 3rd disengagingpawl 42 can pivot on rotatingshaft 42A, and is configured to and can be used for the position ofconveyer belt 30 sliding-contacts with from rotating (swing) between the position thatconveyer belt 30 separates.After a while second separating part will be described.

Loopback part 17 be arranged intranslator unit 16 below.Loopback part 17 comprises oppositely is with 50, and this reverse band is used for temporarily keeping paper P and when duplex printing paper P is turned.Oppositely be with 50 around drivenroller 44, drivenroll 46 andidler roller 48 windings.Oppositely be configured to and drive (rotation) along the direction of arrow F among the figure and direction (fore-and-aft direction) circulation of arrow R with 50.

Oppositely be with 50 by chargingroller 54 charging (applying electric charge thereon), this chargingroller 54 drivenroller 44 near by oppositely with 50 front face side driving.Paper P electrostatic adherence oppositely is being with on 50 and by its transmission.Here,charging roller 54 has as paper P and moves apart oppositely structure with 50 when thecharging roller 54, rather than wherein chargingroller 54 all the time with oppositely contact and by the structure of its driving with 50, like this,charging roller 54 just can not rub attached to oppositely with the print surface of the paper P on 50.That is,charging roller 54 be configured to can (by swing) near oppositely be with 50 and with oppositely be with 50 to separate.

Idlerroller 48 is configured to and can moves back and forth along the direction (being the direction of arrow B shown in Fig. 3) that is basically parallel to across theconveyer belt 30 between drivenroll 28 and idler roller 36.When paper P treats that when oppositely being with 50 to be sent toconveyer belt 30,idler roller 48 is arranged near first disengagingpawl 40, as shown in Figure 3.

Whenidler roller 48 is arranged in this position, can make oppositely with the radius of curvature of 50 the part of twining aroundidler roller 48 less.Therefore, paper P can peel off automatically from this part.Like this, in first embodiment,idler roller 48 has constituted and has been used for paper P from oppositely with 50 second separating parts that separate.Therefore, this structure has simple advantage.

Simultaneously,spur gear 52 is arranged in the top of the 3rd disengagingpawl 42, and transfer roller is arranged in appropriate position on the transfer path of paper P to 56 in how right mode (in the structure in the drawings being seven pairs).For with respect to the transfer roller in the downstream of inkjet print head 20 to 56 (in the structure in the drawings being four pairs), preferably the driven roll of every centering is a spur gear.

Below, will the operation of ink-jet recording apparatus 10 with said structure be described.At first, will the situation that the single channel single face is printed be described.In this case, as shown in Figure 4, first disengagingpawl 40 moves apartconveyer belt 30, the three disengagingpawls 42 andconveyer belt 30 sliding-contacts, and this is driven byconveyer belt 30 clearer 38 (that is oscillatingroller 38B).Therefore, in this state, paper P supplies toconveyer belt 30 by pick-up roller 24 and transfer roller to 56.

The paper P that has supplied on theconveyer belt 30 and remained on theconveyer belt 30 with adhering to is fed into the record position of inkjet print head 20, and writes down (printing) image on the one side (front) of paper P.Then, after finishing this image record, paper P peels off fromconveyer belt 30 by the 3rd disengagingpawl 42, and is sent topaper discharge tray 18 by transfer roller to 56.Like this, just having finished the single channel single face prints.

Below, will the single channel duplex printing be described at the situation of each one of paper P, indexing transfer.In this case, as shown in Figure 5, at first first disengagingpawl 40 andconveyer belt 30 sliding-contacts, and the 3rd disengagingpawl 42 moves apart conveyer belt 30.This moves apartconveyer belt 30 to clearer 38 (oscillatingroller 38B), andcharging roller 54 is by oppositely being with 50 to drive.Therefore, in this state, paper P supplies toconveyer belt 30 by pick-up roller 24 and transfer roller to 56.

The paper P that has supplied on theconveyer belt 30 and remained on theconveyer belt 30 with adhering to is supplied to the record position of inkjet print head 20, and writes down (printing) image on the one side (front) of paper P.Then, further transmission remains on the paper P on theconveyer belt 30 with still adhering to, and by first disengagingpawl 40 it is peeled off (see figure 5) fromconveyer belt 30.

The paper P that peels off fromconveyer belt 30 remains on with adhering to and keeps and oppositely being with on 50 ofconveyer belt 30 identical speed (linear velocity), and the direction transmission of arrow F in the figure.Here,charging roller 54 is sent to fromconveyer belt 30 to move apart before oppositely being with 50 at paper P and oppositely is with 50 (seeing Fig. 6 A).

Subsequently, remain on when oppositely being with on 50 with adhering to fully, oppositely rotate (going back to) with the speed identical along the direction of arrow R, shown in Fig. 6 B withconveyer belt 30 with 50 at paper P.Because it is less oppositely to be furnished with the radius of curvature of part ofidler roller 48 with 50, thus paper P (by second separating part) in a position of this part from oppositely being with 50 to peel off automatically, and paper P is kept byconveyer belt 30 once more with adhering to.

At this moment, the face side that paper P writes down (printing) image is carried out face withconveyer belt 30 and is contacted, and electrostatic adherence thereon.Yet, becauseconveyer belt 30 with oppositely keep identical speed with 50, so the image of record (printings) can not rub withconveyer belt 30 on the front.Therefore, can not cause the picture quality defective.And when paper P turned back toconveyer belt 30,charging roller 34 can move apartconveyer belt 30.

Therefore, the paper P that has remained on theconveyer belt 30 supplies to the record position of inkjet print head 20 with having adhered to again once more, and writes down (printing) image on the another side (back side) of paper P.Paper P recover to adhere to remain on finishing overleaf, print on theconveyer belt 30 during, the 3rd disengagingpawl 42 andconveyer belt 30 sliding-contacts.

Therefore, the paper P that has write down image on its back side peels off fromconveyer belt 30 by the 3rd disengagingpawl 42, and is sent topaper discharge tray 18 by transfer roller to 56.Therefore, finished the single channel duplex printing.Here, when the 3rd disengagingpawl 42 slided with respect toconveyer belt 30, first disengagingpawl 40 moved apartconveyer belt 30, and as shown in Figure 3 and Figure 4, this is driven byconveyer belt 30 clearer 38 (oscillatingroller 38B).

Below, will at paper P once many situations that transmit continuously the single channel duplex printing is described.In this case, at first, first disengagingpawl 40 andconveyer belt 30 sliding-contacts, and the 3rd disengagingpawl 42 moves apart conveyer belt 30.This moves apart conveyer belt 30 (see figure 5)s to clearer 38 (oscillatingroller 38B), andcharging roller 54 is by oppositely being with 50 to drive, andidler roller 48 along the direction of arrow B towards drivenroller 44 move (seeing Fig. 7 A).

That is,idler roller 48 moves to and approachesconveyer belt 30 and in the drivenroller 44 basic position in the middle (that is, oppositely with 50 the radius of curvature position bigger than the radius of curvature of the initial position of idler roller 48) with driven roll 46.Therefore, in this state, many (for example, two) paper P1 and P2 just supply toconveyer belt 30 by pick-up roller 24 and transfer roller to 56 continuously.

Shown in Fig. 7 A, supplied on theconveyer belt 30 and remained on two pieces of paper P1 on theconveyer belt 30 and record position that P2 supplies to inkjet print head 20 successively with adhering to, thereby gone up record (printing) image in the one side (front) of paper.Then, further transmission remains on two pieces of paper P1 and the P2 on theconveyer belt 30 with still adhering to, and by first disengagingpawl 40 it is peeled off (seeing Fig. 7 B) successively fromconveyer belt 30.

Shown in Fig. 7 B, the two pieces of paper P1 that peels off fromconveyer belt 30 and P2 remain on with adhering to successively and keep and oppositely being with on 50 ofconveyer belt 30 identical speed, and by the direction transmission of arrow F in figure.Here,charging roller 54 is sent to fromconveyer belt 30 to move apart before oppositely being with 50 at a piece of paper P1 and oppositely is with 50.

Then, shown in Fig. 7 C, remain at second paper P2 with adhering to fully and oppositely to be with after 50, when the end of a piece of paper P1 byidler roller 48 but the front end of second paper P2 near (contiguous or arrive)idler roller 48 before the time,idler roller 48 is shifted to its initial position.Whenidler roller 48 is disposed in initial position, oppositely rotate (going back to) (seeing Fig. 7 D) with the speed identical along the direction of arrow R withconveyer belt 30 with 50.

Therefore, shown in Fig. 7 D, because it is less oppositely to be furnished with the radius of curvature of part ofidler roller 48 with 50,, and keep once more byconveyer belt 30 so a piece of paper P1 peels off from oppositely being with on 50 automatically in a position of this part (by second separating part) with adhering to.Subsequently, second paper P2 be similarly from oppositely being with 50 to peel off, and remain on theconveyer belt 30 with adhering to once more.

Like this, oppositely be with 50, also can adopt simple structure to make a piece of paper P1 and second paper P2 be recycled toconveyer belt 30, and can not make its reversed order even in duplex printing, be sent to two pieces of paper P1 and P2 one-time continuous.Like this, the data of complexity that just can not need to be used for the print data exchange of the print data of a piece of paper P1 for example and second paper P2 are handled, thereby increase extra burden can not for the processing of print data.

Here, such structure can be set, wherein detect the end of a piece of paper P1 and the front end of second paper P2 etc. by the paper detecting sensor (not shown), this sensor is as identification division.Also such structure can be set, wherein the size of unusable paper P1 and P2, oppositely calculate with velocity of rotation of 50 etc.And when a piece of paper P1 had been sent back toconveyer belt 30, as previously mentioned,charging roller 34 can move apartconveyer belt 30.

When two pieces of paper P1 and P2 supplied toconveyer belt 30 once more, its front of writing down (printing) image was carried out face withconveyer belt 30 and is contacted, and by electrostatic adherence thereon.Yet, becauseconveyer belt 30 with oppositely keep identical speed with 50, so record (printing) image on the front can friction transmission belt 30.Therefore, can not make picture quality produce defective.

Therefore, remained on the record position that two pieces of paper P1 on theconveyer belt 30 and P2 supply to inkjet print head 20 once more successively with having adhered to again, and gone up record (printing) image at its other face (back side).Recover to adhere to from a piece of paper P1 remain on theconveyer belt 30 until finish overleaf printing during, the 3rd disengagingpawl 42 andconveyer belt 30 sliding-contacts.

Therefore, the two pieces of paper P1 and the P2 that have write down image on the back side peel off fromconveyer belt 30 successively by the 3rd disengagingpawl 42, and are sent topaper discharge tray 18 by transfer roller to 56.Like this, just finished the continuous single channel duplex printing of plurality of sheets of paper.Here, when the 3rd disengagingpawl 42 slided with respect toconveyer belt 30, first disengagingpawl 40 moved apartconveyer belt 30, and as shown in Figure 3 and Figure 4, this is driven byconveyer belt 30 clearer 38 (oscillatingroller 38B).

Below, the multichannel duplex printing will be described.In this case, at first, first disengagingpawl 40 and the 3rd disengagingpawl 42 all move apart conveyer belt 30.And this moves apart conveyer belt 30 (see figure 5)s to clearer 38 (oscillatingroller 38B), and makes chargingroller 54 by oppositely being with 50 to drive.Therefore, in this state, paper P supplies toconveyer belt 30 by pick-uproller 24 and transfer roller to 56.

Supplied toconveyer belt 30 and remained on the record position that paper P on theconveyer belt 30 is fed into inkjet print head 20 with adhering to, shown in Fig. 8 A, and gone up record (printing) image in the one side (front) of paper P.Then, further transmission remains on the paper P on theconveyer belt 30 with still adhering to, and it is repeatedly supplied to the record position of ink jet print head 20.At this moment, chargingroller 34 can move apartconveyer belt 30 when paper P is through chargingroller 34 at every turn.

When on the front, finally printing, when paper P through when zone of first disengagingpawl 40, first disengagingpawl 40 final print finish before withconveyer belt 30 sliding-contacts, shown in Fig. 8 B.Therefore, on the front after final the printing, keep and the paper P that transmits peels off fromconveyer belt 30 by first disengagingpawl 40 byconveyer belt 30 with adhering to.The paper P that separates fromconveyer belt 30 remains on with being attached and keeps and oppositely being with on 50 ofconveyer belt 30 identical speed, and the direction of arrow F is transmitted in the figure.

Here, chargingroller 54 is sent to fromconveyer belt 30 to move apart before oppositely being with 50 at paper P and oppositely is with 50.Then, remain on when oppositely being with on 50 with adhering to fully, oppositely rotate (going back to) with the speed identical along the direction of arrow R, shown in Fig. 8 C withconveyer belt 30 with 50 at paper P.Because it is less oppositely to be furnished with the radius of curvature of part ofidler roller 48 with 50, thus paper P in a position of this part (by second separating part) from oppositely being with 50 to peel off automatically, and paper P remains on theconveyer belt 30 with adhering to once more.

At this moment, the paper P that its front face side writes down (printing) image carries out face withconveyer belt 30 and contacts, and by electrostatic adherence thereon.Yet, becauseconveyer belt 30 with oppositely keep identical speed with 50, so record (printing) image on the front can friction transmission belt 30.Therefore, can not make picture quality produce defective.

Therefore, the paper P that has remained on theconveyer belt 30 is supplied to the record position of inkjet print head 20 with having adhered to again once more, and writes down (printing) image on its another side (back side).Then, shown in Fig. 8 A, paper P keeps remaining on theconveyer belt 30 with adhering to, and is further transmitted and repeatedly be supplied to the record position of ink jet print head 20.Similar during with printing on the front, chargingroller 34 all can move apartconveyer belt 30 when paper P is through chargingroller 34 at every turn.

When finally printing overleaf, as paper P during by the 3rd disengagingpawl 42 regional, the 3rd disengagingpawl 42 before finishing final printing withconveyer belt 30 sliding-contacts, shown in Fig. 8 D.Therefore, go up overleaf after final the printing, remained on theconveyer belt 30 and the paper P that is transmitted byconveyer belt 30 peels off fromconveyer belt 30 by the 3rd disengagingpawl 42 with having adhered to.The paper P that separates fromconveyer belt 30 is sent topaper discharge tray 18 by transfer roller to 56.

Like this, just finished the multichannel duplex printing.Here, when the 3rd disengagingpawl 42friction transmission belts 30, first disengagingpawl 40 moves apartconveyer belt 30, and as shown in Figure 3 and Figure 4, this is driven byconveyer belt 30 clearer 38 (oscillatingroller 38B).

Below, second embodiment will be described.As shown in Figure 9, the difference of second embodiment and above-mentioned first embodiment only is, is provided with a pair of idler roller 60 (replacing idler roller 48) towards driven roller 44 a little atloopback part 17 places, and second disengagingpawl 62 is set as second separating part.Therefore, the part identical with above-mentioned first embodiment used same Reference numeral, and suitably omitted the description to it.Not shown clearer 38 in Fig. 9.

Described twoidler rollers 60 are arranged apart from each other with preset space length, oppositely are with 50 thereby widen along vertical direction, and be configured to can be along movement in vertical direction when remaining the state that wherein keeps this predetermined space.That is, this is supported on a unshowned framework place to idlerroller 60A and 60B, thereby with the preset space length vertical separation, and be supported on the surperficial vertical direction with accompanying drawing.Therefore, this toidler roller 60 be configured to by this framework along vertical direction move can towards with move away fromconveyer belt 30.

Second disengagingpawl 62 be fixedly arranged to become when this is raised to idler roller 60 (, whenidler roller 60 shifts near conveyer belt 30) can with oppositely with the 50 part sliding-contacts that are furnished with idler roller 60A.Second idler roller 62 is configured to auxiliary paper P from oppositely being with 50 to peel off, and guiding paper P is to supply with (transmission) toconveyer belt 30 with paper P.

Below, description is had the operation of second embodiment of said structure.In the description of this operation, mass part is identical with first embodiment.Therefore, will only be described in wherein single channel duplex printing under the situation that at every turn transmits a piece of paper P off and on, transmit single channel duplex printing under the situation of plurality of sheets of paper P and multichannel duplex printing continuously therein at every turn.With the description of omitting to other printing model.

At first, with the single channel duplex printing that is described under the situation that transmits a piece of paper P off and at every turn.In this case, first disengagingpawl 40 andconveyer belt 30 sliding-contacts, and the 3rd disengagingpawl 42 moves apart conveyer belt 30.This moves apart conveyer belt 30 (see figure 5)s to clearer 38 (oscillatingroller 38B), and makes chargingroller 54 by oppositely being with 50 to drive.And this remains on lower position (seeing Figure 10 A) toidler roller 60, and it separates with second disengaging pawl 62 (with conveyer belt 30).

Therefore, in this state, to 56 paper P is supplied toconveyer belt 30 by pick-uproller 24 and transfer roller.Shown in Figure 10 A, supplied toconveyer belt 30 and remained on the record position that paper P on theconveyer belt 30 is fed into inkjet print head 20 with adhering to, and gone up record (printing) image in the one side (front) of paper P.Then, further transmission remains on the paper P on theconveyer belt 30 with still adhering to, and by first disengagingpawl 40 it is peeled off (seeing Figure 10 B) fromconveyer belt 30.

The paper P that peels off fromconveyer belt 30 remains on shown in Figure 10 B with adhering to and keeps and oppositely being with on 50 ofconveyer belt 30 identical speed, and the direction shown in the arrow F is transmitted in the figure.Here, chargingroller 54 is sent to fromconveyer belt 30 to move apart before oppositely being with 50 at paper P and oppositely is with 50.Then, remain on when oppositely being with on 50 at paper P, oppositely band rotates (going back to) with the speed identical withconveyer belt 30 along the direction of arrow R, shown in Figure 10 C with adhering to fully.

Then, shown in Figure 11 A, with this backward rotation is carried out simultaneously be, this is raised withnear conveyer belt 30idler roller 60, and makes oppositely the part and 62 sliding-contacts of second disengaging pawl that is furnished withidler roller 60A with 50.Here, treat atconveyer belt 30 and transmit between oppositely with 50 and return at every turn under one the situation that this can just remain on this upper position from beginning toidler roller 60 at paper P, and oppositely be with 50 to slide with respect tosecond disengaging pawl 62.

Like this, when this remains on this upper position place toidler roller 60, make oppositely less with the radius of curvature of 50 (second disengagingpawl 62 oppositely slides with 50 with respect to this) bylast idler roller 60A, thereby make paper P in this position (that is, than being sent to fromconveyer belt 30 oppositely with 50 position) more near the position of drivenroll 28 peel off automatically from oppositely being with 50.Assist paper P to peel off by second disengagingpawl 62, and guide paper P and it is remained on theconveyer belt 30 with adhering to once more by second disengaging pawl 62.Here, can be provided with such structure, wherein descendidler roller 60B this moment not with oppositely be with 50 to contact.

When paper P was supplied toconveyer belt 30 once more, the front face side of record (printing) image of paper P was carried out face withconveyer belt 30 and is contacted, and by electrostatic adherence thereon.Yet, regulate the rotating speed of drivenroller 44, thereby do not change when 62 frictions of second disengaging pawl oppositely make oppositely the speed with 50 with 50 the time, andconveyer belt 30 with oppositely with the identical speed of 50 maintenances.Therefore, record (printing) image on the front does not rub with conveyer belt 30.So, can not cause the picture qualitydefective.Charging roller 34 can move apartconveyer belt 30 whenconveyer belt 30 is got back in paper P supply.

Therefore, remained on the record position that paper P on theconveyer belt 30 supplies to inkjet print head 20 once more with having adhered to again, shown in Figure 11 B, and gone up record (printing) image at its another side (back side).Recovering to remain on theconveyer belt 30 during finishing that the back side prints the 3rd disengagingpawl 42 andconveyer belt 30 sliding-contacts from paper P with adhering to.

Therefore, the paper P that has recorded image on its back side peels off fromconveyer belt 30 by the 3rd disengagingpawl 42, shown in Figure 11 C, and is sent topaper discharge tray 18 by transfer roller to 56.Like this, just finished and supplied with a piece of paper at every turn off and on and open single channel duplex printing under the situation of P.

Here, when the 3rd disengagingpawl 42 andconveyer belt 30 sliding-contacts, first disengagingpawl 40 separates withconveyer belt 30, and as shown in Figure 3 and Figure 4, this is driven byconveyer belt 30 clearer 38 (oscillatingroller 38B).And shown in Figure 11 C, this moves to lower position toidler roller 60.

Below, transmit plurality of sheets of paper continuously at every turn and open single channel duplex printing under the situation of P being described in.In this case, at first, first disengagingpawl 40 andconveyer belt 30 sliding-contacts, and the 3rd disengagingpawl 42 moves apart conveyer belt 30.This moves apart conveyer belt 30 (see figure 5)s to clearer 38 (oscillatingroller 38B), and chargingroller 54 is by oppositely being with 50 to drive, and this moves to lower position (seeing Figure 12 A) toidler roller 60 away from second disengaging pawl 62 (with conveyer belt 30).

Therefore, in this state, many (for example, two) paper P1 and P2 just are supplied toconveyer belt 30 by pick-uproller 24 and transfer roller to 56 continuously.Shown in Figure 12 A, supplied toconveyer belt 30 and remained on two pieces of paper P1 on theconveyer belt 30 and record position that P2 supplies to inkjet print head 20 successively with adhering to, and gone up record (printing) image in the one side (front) of paper.Then, further transmission remains on two pieces of paper P1 and the P2 on theconveyer belt 30 with still adhering to, and peels off (seeing Figure 12 B) fromconveyer belt 30 successively by first disengagingpawl 40.

Shown in Figure 12 B, the two pieces of paper P1 that separates fromconveyer belt 30 and P2 remain on with adhering to successively and keep and oppositely being with on 50 ofconveyer belt 30 identical speed, and the direction transmission of arrow F in the figure.At this moment, chargingroller 54 is transported to fromconveyer belt 30 to move apart before oppositely being with 50 at a piece of paper P1 and oppositely is with 50.

Then, shown in Figure 12 C, second paper P2 remained on with having adhered to fully oppositely be with on 50 after, when the end of a piece of paper P1 by second disengaging pawl 62 (withlast idler roller 60A) and front end no show stillsecond disengaging pawl 62 of second paper P2 when (withlast idler roller 60A), oppositely rotate (going back to) with the speed identical along the direction of arrow R withconveyer belt 30 with 50.

Then, as shown in FIG. 13A, be, this is raise withnear conveyer belt 30 toidler roller 60, and make oppositely part sliding-contact second disengagingpawl 62 that is furnished withidler roller 60A with 50 with this backward rotation is carried out simultaneously.Here, as mentioned above, can be provided with such structure, wherein descendidler roller 60B this moment not with oppositely be with 50 to contact.

Like this, when this remains on the upper position place toidler roller 60, make oppositely less with the curvature of 50 (second disengagingpawl 62 slides with respect to this reverse band) bylast idler roller 60A, thereby make a piece of paper P1 in this position (that is, than being sent to fromconveyer belt 30 oppositely with 50 position) more near the position of drivenroll 28 peel off automatically from oppositely being with 50.Assist peeling off of a piece of paper P1 by second disengagingpawl 62, and guide a piece of paper P1 and it is remained on theconveyer belt 30 with adhering to once more by second disengaging pawl 62.Subsequently, shown in Figure 13 B, second paper P2 be equally from oppositely being with 50 to peel off, and remain on theconveyer belt 30 with adhering to once more.

Like this,, adopt simple structure, also a piece of paper P1 and second paper P2 can be recycled on theconveyer belt 30, and can not make its reversed order although each two pieces of paper P1 and P2 are sent to continuously and oppositely are with 50 in duplex printing.Like this, just can not need to be used for for example to make the data of complexity of the print data exchange of the print data of a piece of paper P1 and second paper P2 to handle, thereby increase extra burden can not for the processing of print data.

Here, such structure be can be provided with, wherein the end of a piece of paper P1 and the front end of second paper P2 etc. detected by paper detecting sensor (, not shown) as identification division.Also can be provided with such structure, wherein utilize the size of paper P1 and P2, oppositely wait with 50 rotating speed and calculate.And chargingroller 34 can move apartconveyer belt 30 when a piece of paper P1 supplies toconveyer belt 30 again, as mentioned above.

When two pieces of paper P1 and P2 supplied toconveyer belt 30 again, it writes down (printing) had the front of image to carry out face withconveyer belt 30 to contact, and by electrostatic adherence thereon.Yet, regulate the rotating speed of drivenroller 44, thereby do not change when 62 frictions of second disengaging pawl oppositely make oppositely the speed with 50 with 50 the time, andconveyer belt 30 and oppositely be with the same speed of 50 maintenances.Therefore, record (printing) image on the front can not rub with conveyer belt 30.Therefore, can not cause the picture quality defective.

Thereby, remained on the record position that two pieces of paper P1 on theconveyer belt 30 and P2 sequentially supply to inkjet print head 20 once more with having adhered to again, and gone up record (printing) image at its another side (back side).Recovering to remain on theconveyer belt 30 during finishing that the back side prints the 3rd disengagingpawl 42 andconveyer belt 30 sliding-contacts from paper P1 with adhering to.

Therefore, the two pieces of paper P that has recorded image on its back side peels off fromconveyer belt 30 successively by the 3rd disengagingpawl 42, shown in Figure 13 C, and is sent topaper discharge tray 18 by transfer roller to 56.Like this, just finished the continuous single channel duplex printing of plurality of sheets of paper.

Here, when the 3rd disengagingpawl 42 slided with respect toconveyer belt 30, first disengagingpawl 40 moved apartconveyer belt 30, and as shown in Figure 3 and Figure 4, this is driven byconveyer belt 30 clearer 38 (oscillatingroller 38B).And shown in Figure 13 C, this moves to lower position toidler roller 60.

Below, the multichannel duplex printing will be described.This printing model and above-mentioned single channel duplex printing difference only are that paper P supplies to the record position place of inkjet print head 20 for many times, and therefore do not illustrate.

At first, first disengagingpawl 40 and the 3rd disengagingpawl 42 all move apart conveyer belt 30.And this moves apart conveyer belt 30 (see figure 5)s to clearer 38 (oscillatingroller 38B), and chargingroller 54 is by oppositely being with 50 to drive.Like this, under this state, paper P supplies toconveyer belt 30 by pick-uproller 24 and transfer roller to 56.

The paper P that has supplied toconveyer belt 30 and remained on theconveyer belt 30 with adhering to is fed into the record position of inkjet print head 20, and writes down (printing) image on the one side (front) of this paper P.Then, further transmission remains on the paper P on theconveyer belt 30 with still adhering to, and repeatedly supplies to the record position of ink jet print head 20.At this moment, chargingroller 34 all moves apartconveyer belt 30 when paper P is through chargingroller 34 at every turn.

When on the front, finally printing, as paper P during by first disengagingpawl 40 regional, first disengagingpawl 40 final print finish before sliding-contact conveyer belt 30.Therefore, on the front after final the printing, remained on theconveyer belt 30 with having adhered to and peeled off fromconveyer belt 30 by first disengagingpawl 40 by the paper P of its transmission.The paper P that peels off fromconveyer belt 30 remains on with adhering to and keeps and oppositely being with on 50 ofconveyer belt 30 identical speed, and along the direction transmission of arrow F.

Here, chargingroller 54 is sent to fromconveyer belt 30 to move apart before oppositely being with 50 at paper P and oppositely is with 50.Then, remain on when oppositely being with on 50 with adhering to fully, oppositely rotate (going back to) with the speed identical along the direction of arrow R withconveyer belt 30 with 50 at paper P.

Then, be, this is raise withnear conveyer belt 30 toidler roller 60, and make oppositely part sliding-contact second disengagingpawl 62 that is furnished withidler roller 60A with 50 with this backward rotation is carried out simultaneously.Here, when paper P each one transmitted atconveyer belt 30 with between oppositely being with 50, this can just remain on this upper position from beginning toidler roller 60, and oppositely was with 50 with respect to 62 slips of second disengaging pawl, as mentioned above.

Like this, when this remains on the upper position place toidler roller 60, less by feasible 50 (second disengagingpawl 62 slides with respect to this reverse band) radius of curvature of oppositely being with of lastidler roller 60A, thereby paper P in this position (that is, than being sent to fromconveyer belt 30 oppositely with 50 position) more near the position of drivenroll 28 peel off automatically from oppositely being with 50.Assist peeling off of paper P by second disengagingpawl 62, and guide paper P and it is remained on theconveyer belt 30 with adhering to once more by second disengaging pawl 62.Here, can be provided with such structure, wherein descendidler roller 60B this moment not with oppositely be with 50 to contact, as mentioned above.

When paper P supplies toconveyer belt 30 again, paper P thereon record (printing) have the front of image to carry out face to contact withconveyer belt 30, and thereon by electrostatic adherence.Yet, regulate the rotating speed of drivenroller 44, thereby do not change when 62 frictions of second disengaging pawl oppositely make oppositely the speed with 50 with 50 the time, andconveyer belt 30 and oppositely be with the same speed of 50 maintenances.Therefore, record (printing) image on the front does not rub with conveyer belt 30.Therefore, can not cause the picture quality defective.

Therefore, the paper P that has remained on theconveyer belt 30 is fed into the record position of inkjet print head 20 with having adhered to again once more, and writes down (printing) image on its another side (back side).Then, paper P keeps remaining on theconveyer belt 30 with adhering to, and is further transmitted and repeatedly be supplied to the record position of ink jet print head 20.Identical during with printing on the front, chargingroller 34 all can move apartconveyer belt 30 when paper P is by chargingroller 34 at every turn.

When finally printing on overleaf, as paper P during by the 3rd disengagingpawl 42 regional, the 3rd disengagingpawl 42 final print finish before sliding-contact conveyer belt 30.Therefore, go up overleaf after final the printing, remained on theconveyer belt 30 with having adhered to and peeled off fromconveyer belt 30 by the 3rd disengagingpawl 42, and be sent topaper discharge tray 18 to 56 by transfer roller by the paper P of its transmission.

Like this, just finished the multichannel duplex printing.Here, when the 3rd disengagingpawl 42 slided with respect toconveyer belt 30, first disengagingpawl 40 moved apartconveyer belt 30, and as shown in Figure 3 and Figure 4, this is driven byconveyer belt 30 clearer 38 (oscillatingroller 38B).And this moves to lower position toidler roller 60.

Below the 3rd embodiment will be described.As shown in figure 14, the 3rd embodiment and the above-mentioned first embodiment difference only are, second disengaging pawl 64 (it is as second separating part) can be rotatably set inloopback part 17 places towards driven roll 28 a little, and idler roller 66 (replacing idler roller 48) is fixedly placed on the vicinity of second disengaging pawl 64.Therefore, the part identical with above-mentioned first embodiment represent with identical Reference numeral, and suitably omitted the description to it.Clearer 38 is not shown in Figure 14.

Similar with the 3rd disengagingpawl 42 to first disengagingpawl 40, second disengagingpawl 64 can pivot onrotating shaft 64A, and be configured to can be used for oppositely with the position of 50 sliding-contacts and with oppositely with 50 positions of separating between rotation (swing).Idler roller 66 is fixedly placed on the vicinity ofsecond disengaging pawl 64, promptly, oppositely be with 50 sliding-contacts thereby makesecond disengaging pawl 64 be rotated down Shi Keyu at second disengagingpawl 64 in the pre-position that makes thisidler roller 66 near conveyer belt 30 (near the position of driven roll 28).

Below, description is had the operation of the 3rd embodiment of said structure.In the description of this operation, a plurality of parts are identical with the part of first embodiment and/or second embodiment.Therefore, only be described in and transmit plurality of sheets of paper continuously at every turn and open single channel duplex printing and multichannel duplex printing under the situation of P.With the description of omitting to other printing model.

At first, transmit plurality of sheets of paper at every turn continuously and open single channel duplex printing under the situation of P describing.In this case, at first, first disengagingpawl 40 andconveyer belt 30 sliding-contacts, and the 3rd disengagingpawl 42 moves apart conveyer belt 30.This moves apart conveyer belt 30 (see figure 5)s to clearer 38 (oscillatingroller 38B), and chargingroller 54 is by oppositely being with 50 to drive, and second disengagingpawl 64 with oppositely be with 50 to separate (seeing Figure 15 A).

Therefore, in this state, many (for example, two) paper P1 and P2 supply toconveyer belt 30 by pick-uproller 24 and transfer roller continuously to 56.Shown in Figure 15 A, be supplied toconveyer belt 30 and remained on two pieces of paper P1 on theconveyer belt 30 and record position that P2 supplies to inkjet print head 20 successively with adhering to, and gone up record (printing) image in the one side (front) of paper.Then, further transmission remains on two pieces of paper P1 and the P2 on theconveyer belt 30 with still adhering to, and peels off (seeing Figure 15 B) by first disengagingpawl 40 successively fromconveyer belt 30.

Shown in Figure 15 B, the two pieces of paper P1 that peels off fromconveyer belt 30 and P2 remain on with adhering to successively and keep and oppositely being with on 50 ofconveyer belt 30 identical speed, and the direction of arrow F is transmitted in the figure.At this moment, chargingroller 54 is sent to fromconveyer belt 30 to move apart before oppositely being with 50 at a piece of paper P1 and oppositely is with 50.

Then, shown in Figure 15 C, second paper P2 remained on with having adhered to fully oppositely be with on 50 after, when the end of a piece of paper P1 by second disengaging pawl 64 (with idler roller 66) but front end no show stillsecond disengaging pawl 64 of second paper P2 when (with idler roller 66), oppositely rotate (going back to) with the speed identical along the direction of arrow R withconveyer belt 30 with 50.

Then, shown in Figure 16 A, with this backward rotation is carried out simultaneously be, described second disengagingpawl 64 is rotated down (towards oppositely being with 50), and oppositely with 50 part sliding-contact second disengagingpawls 64 that are furnished withidler roller 66.

Therefore, a piece of paper P1 by second disengaging pawl 64 (second separating part) than be sent to fromconveyer belt 30 oppositely with 50 more near the position of drivenroll 28 from oppositely being with 50 to peel off, and remain on theconveyer belt 30 with adhering to once more.Subsequently, shown in Figure 16 B, second paper P2 be equally from oppositely being with 50 to peel off, and remain on theconveyer belt 30 with adhering to once more.

Like this, oppositely be with on 50, also can adopt simple structure to make a piece of paper P1 and second paper P2 be recycled toconveyer belt 30, and can not make its reversed order even in duplex printing, be sent to two pieces of paper P1 and P2 one-time continuous.Like this, just can not need to be used for for example to make the data of complexity of the print data exchange of the print data of a piece of paper P1 and second paper P2 to handle, thereby increase extra burden can not for the processing of print data.

Here, such structure be can be provided with, wherein the end of a piece of paper P1 and the front end of the second paper P2 etc. detected by paper detecting sensor (, not shown) as identification division.Also can be provided with such structure, wherein utilize the size of paper P1 and P2, oppositely wait with 50 rotating speed and calculate.And when a piece of paper P1 was supplied toconveyer belt 30 again, chargingroller 34 can move apartconveyer belt 30, as previously mentioned.

When two pieces of paper P1 and P2 supplied toconveyer belt 30 again, it writes down (printing) had the front of image to carry out face withconveyer belt 30 to contact, and by electrostatic adherence thereon.Yet, regulate the rotating speed of drivenroller 44, thereby do not change when 64 frictions of second disengaging pawl oppositely make oppositely the speed with 50 with 50 the time, andconveyer belt 30 and oppositely be with the same speed of 50 maintenances.Therefore, record (printing) image on the front can not rub with conveyer belt 30.Therefore, can not cause the picture quality defective.

Like this, remained on the record position that two pieces of paper P1 on theconveyer belt 30 and P2 supply to inkjet print head 20 once more successively with having adhered to again, and gone up record (printing) image at its another side (back side).Recover to remain on from a piece of paper P1 on theconveyer belt 30 with adhering to up to finish print overleaf during, the 3rd disengagingpawl 42 andconveyer belt 30 sliding-contacts.

Therefore, the two pieces of paper P1 and the P2 that have write down image on its back side peel off fromconveyer belt 30 successively by the 3rd disengagingpawl 42, shown in Figure 16 C, and are sent topaper discharge tray 18 by transfer roller to 56.Like this, just finished the single channel duplex printing of many continuous forms.

Here, when the 3rd disengagingpawl 42 slided with respect toconveyer belt 30, first disengagingpawl 40 moved apartconveyer belt 30, and as shown in Figure 3 and Figure 4, this is driven byconveyer belt 30 clearer 38 (oscillatingroller 38B).And shown in Figure 16 C,second disengaging pawl 64 with oppositely be with 50 to separate.

Below the multichannel duplex printing will be described.This printing model and above-mentioned single channel duplex printing difference only are that paper P supplies to the record position of inkjet print head 20 for many times, and be therefore not shown.

At first, first disengagingpawl 40 and the 3rd disengagingpawl 42 all move apart conveyer belt 30.And this moves apart conveyer belt 30 (see figure 5)s to clearer 38 (oscillatingroller 38B), and chargingroller 54 is by oppositely being with 50 to drive.Therefore, in this state, paper P supplies toconveyer belt 30 by pick-uproller 24 and transfer roller to 56.

The paper P that has supplied toconveyer belt 30 and remained on theconveyer belt 30 with adhering to is fed into the record position of inkjet print head 20, and writes down (printing) image on the one side (front) of paper P.Then, further transmission remains on the paper P on theconveyer belt 30 with still adhering to, and it is repeatedly supplied to the record position of ink jet print head 20.At this moment, chargingroller 34 all can move apartconveyer belt 30 when paper P is through chargingroller 34 at every turn.

When on the front, finally printing, as paper P during through first disengagingpawl 40 regional, first disengagingpawl 40 final print finish before withconveyer belt 30 sliding-contacts.Therefore, after the final printing on the front, keep and the paper P that transmits peels off fromconveyer belt 30 by first disengagingpawl 40 byconveyer belt 30 with adhering to.The paper P that separates fromconveyer belt 30 remains on with being attached and keeps and oppositely being with on 50 ofconveyer belt 30 identical speed, and is transmitted along the direction of arrow F.

At this moment, chargingroller 54 is sent to fromconveyer belt 30 to move apart before oppositely being with 50 at paper P and oppositely is with 50.Then, remain on when oppositely being with on 50 with adhering to fully, oppositely rotate (going back to) with the speed identical along the direction of arrow R withconveyer belt 30 with 50 at paper P.

Then, with this backward rotation is carried out simultaneously be,second disengaging pawl 64 is rotated down (towards oppositely being with 50), and oppositely with 50 part sliding-contact second disengagingpawls 64 that are furnished with idler roller 66.As a result, paper P is more being peeled off from oppositely being with 50 by second disengaging pawl 64 (second separating part) near the position of drivenroll 28 with 50 than being sent to fromconveyer belt 30 oppositely, and remains on theconveyer belt 30 with adhering to once more.

At this moment, the record (printing) of paper P has the front of image to carry out face withconveyer belt 30 to contact, and electrostatic adherence thereon.Yet, regulate the rotating speed of drivenroller 44, thereby making oppositely oppositely to be with in 64 frictions of second disengaging pawl with 50 rotating speed did not change at 50 o'clock, andconveyer belt 30 and oppositely with the identical speed of 50 maintenances.Therefore, record (printing) image on the front can not rub with conveyer belt 30.Therefore, can not cause the picture quality defective.

Therefore, the paper P that has remained on theconveyer belt 30 is fed into the record position of inkjet print head 20 with having adhered to again once more, and writes down (printing) image on its another side (back side).Then, paper P keeps remaining on theconveyer belt 30 with adhering to, and is repeatedly further transmitted and supply to the record position of ink jet print head 20.Identical during with printing on the front, chargingroller 34 all moves apartconveyer belt 30 when paper P is through chargingroller 34 at every turn.

When finally printing on overleaf, as paper P during by the 3rd disengagingpawl 42 regional, the 3rd disengagingpawl 42 final print finish before sliding-contact conveyer belt 30.Therefore, after finally printing overleaf, kept and the paper P that transmits peels off fromconveyer belt 30 by the 3rd disengagingpawl 42 with adhering to, and be sent topaper discharge tray 18 to 56 by transfer roller byconveyer belt 30.

So just finished the multichannel duplex printing.Here, when the 3rd disengagingpawl 42friction transmission belts 30, first disengagingpawl 40 moves apartconveyer belt 30, and as shown in Figure 3 and Figure 4, this is driven byconveyer belt 30 clearer 38 (oscillatingroller 38B).And,second disengaging pawl 64 with oppositely be with 50 to separate.

At last, the 4th embodiment will be described.Shown in Figure 17 A and 17B, the 4th embodiment is formed withreverse drum 70, rather than oppositely is with 50 around what drivenroller 44, drivenroll 46 and idler roller 48 (perhaps 60 or 66)twined.Oppositely drum 70 is constructed to be permeable to drive along the fore-and-aft direction rotation, and is constructed to be permeable to electrostatic adherence paper P.In this case, needsecond disengaging pawl 68 as being used for from second separating part ofreverse drum 70 release papers P.

Particularly, under the situation ofreverse drum 70, can not the less zone of a radius of curvature be set with above-mentioned to be used for oppositely being with of first embodiment andsecond embodiment 50 the same.Therefore, (whenreverse drum 70 goes back to) paper P can not peel off automatically oppositely the time.So, must locate to be provided withsecond disengaging pawl 68 in the position (position of the most close conveyer belt 30) that paper P supply may be got back toconveyer belt 30, and the paper P that utilizes thissecond disengaging pawl 68 will remain on thereverse drum 70 forces to peel off with adhering to fromreverse drum 70.

Second disengagingpawl 68 can be configured to all the time and reversedrum 70 sliding-contacts, only can also be configured to when paper P peels off andoppositely drum 70 sliding-contacts.Forreverse drum 70, print at the single channel single face, supply with off and at every turn in the single channel duplex printing, single channel duplex printing and multichannel duplex printing under many supply situations continuously under the situation, the 3rd embodiment oppositely is with 50 just to be substituted by thisreverse drum 70 simply.Therefore, for the description of these operations, will only describe the multichannel duplex printing, and omit other printing model.

Under multichannel duplex printing situation, at first, first disengagingpawl 40 and the 3rd disengagingpawl 42 all move apartconveyer belt 30, and this moves apart conveyer belt 30 (see figure 5)s to clearer 38 (oscillatingroller 38B).Therefore, in this state, paper P supplies toconveyer belt 30 by pick-uproller 24 and transfer roller to 56.

The paper P that has supplied toconveyer belt 30 and remained on theconveyer belt 30 with adhering to is supplied to the record position of inkjet print head 20, and writes down (printing) image on the one side (front) of paper P.Then, further transmission remains on the paper P on theconveyer belt 30 with still adhering to, and repeatedly supplies to the record position of ink jet print head 20.At this moment, chargingroller 34 all moves apartconveyer belt 30 when paper P passes through chargingroller 34 at every turn.

When on the front, finally printing, the zone by first disengagingpawl 40 as paper P, first disengagingpawl 40 final print finish before sliding-contact conveyer belt 30.Therefore, after the final printing on the front, kept and the paper P that transmits peels off fromconveyer belt 30 by first disengagingpawl 40 byconveyer belt 30 with adhering to.The paper P that peels off fromconveyer belt 30 remains on thereverse drum 70 that keeps withconveyer belt 30 identical speed with adhering to, and is transmitted (seeing Figure 17 A) along the direction of arrow F.

Then, when paper P remained on thereverse drum 70 with adhering to fully,oppositely drum 70 rotated (going back to) with the speed identical withconveyer belt 30 along the direction of arrow R.Therefore, paper P peels off fromreverse drum 70 by second disengagingpawl 68 that slides with respect to reversedrum 70, and remains on theconveyer belt 30 with adhering to once more and (see Figure 17 B).

At this moment, the record (printing) of paper P has the front face side of image to carry out face withconveyer belt 30 to contact, and electrostatic adherence thereon.Yet becauseoppositely drum 70 keeps identical speed withconveyer belt 30, record (printing) image on the front can not rub with conveyer belt 30.Therefore, can not cause mass defect.

Therefore, the paper P that has remained on theconveyer belt 30 supplies to the record position of inkjet print head 20 with having adhered to again once more, and writes down (printing) image on its another side (back side).Then, paper P remains on theconveyer belt 30 with still adhering to and is further transmitted, and repeatedly supplies to the record position of ink jet print head 20.Identical when printing on the front, chargingroller 34 all moves apartconveyer belt 30 during through chargingroller 34 at each paper P.

When finally printing on overleaf, as paper P during by the 3rd disengagingpawl 42 regional, the 3rd disengagingpawl 42 final print finish before sliding-contact conveyer belt 30.Therefore, after the final printing of going up overleaf, remained on theconveyer belt 30 with having adhered to and peeled off fromconveyer belt 30 by the 3rd disengagingpawl 42, and be sent topaper discharge tray 18 to 56 by transfer roller by the paper P of its transmission.

Like this, just finished the multichannel duplex printing.Here, when the 3rd disengagingpawl 42 slided with respect toconveyer belt 30, first disengagingpawl 40 moved apartconveyer belt 30, and as shown in Figure 3 and Figure 4, this is driven byconveyer belt 30 clearer 38 (oscillatingroller 38B).

The as above description that first to the 4th embodiment is done for the paper P that has printed one side, is used to make 50 (the perhaps reverse drums 70) of oppositely being with of paper P upset to keep the still unprinted one side of paper P with adhering to.Therefore, can avoid owing to the scraping printing surface causes the picture quality variation.In addition, by being remained on with adhering to, paper P oppositely is with 50 (or reverse drums 70) to go up certain hour, the duration that can guarantee ink setting.(that is, can carry out face and provide a certain amount of time before contacting at printing surface andconveyer belt 30.)

And, (or oppositely drums 70) drives (rotation) with the speed rotation identical withconveyer belt 30 because oppositely with 50, so, can not slide between paper P and theconveyer belt 30 when paper P supplies withback conveyer belt 30 and printing surface when keeping thereon (carrying out face with it contacts) with adhering to.Therefore, even at this moment, also avoided owing to the scraping printing surface causes the picture quality variation.

In addition, because oppositely with 50 (or oppositely drums 70) be arranged onconveyer belt 30 under, and with paper P from the set positions that oppositely (or oppositely drums 70) is sent toconveyer belt 30 with 50 become than with paper P from position thatconveyer belt 30 is sent to oppositely with 50 (or oppositely drums 70) more near drivenroll 28, so the path of paper P is not made than long such shortcoming, thereby can once more paper P be supplied toconveyer belt 30 fast from oppositely being with 50 (orreverse drums 70).Therefore, the reduction of productivity ratio when duplex printing can be avoided, thereby the efficient of duplex printing can be improved.

In addition, under the duplex printing situation that plurality of sheets of paper P supplies with together continuously, can be simply by adopting such simple structure to overturn and supplying with a piece of paper P1 and second paper P2 once more, and can not make its reversed order, this structure during front end no show still second separating part of second paper P2 etc., makes oppositely reverse with 50 rotation by second separating part at the end of a piece of paper P1.

Therefore, do not need for example to be used on computers with the complex process of the print data exchange of the print data of a piece of paper P1 and second paper P2 etc., thereby can avoid added burden that print data is handled.As a result, can avoid taking place the problem that causes such as reduction owing to the increase of data processing time and data-handling capacity.

It should be noted that by drive the structure that (rotation) transmits theconveyer belt 30 of paper P and oppositely be not limited to keep by Electrostatic Absorption paper P with 50 (or reverse drums 70) along the predetermined direction rotation.Also can adopt such structure,, for example wait to keep paper P with friction, the suction of paper P or the paper P that adheres wherein by non-electrostatic methods.

The position of drivenroller 26 and drivenroll 28 can exchange, and the position of drivenroller 44 and drivenroll 46 can exchange.Drivenroller 26 is connected with the drive motors (not shown) by unshowned transmission device (perhaps direct) with driven roller 44.Drive motors is not particularly limited its type.

And although not shown, described ink-jet recording apparatus 10 is equipped with record head control section and systems control division branch.This record head control section is determined the nozzle that ink droplet jet time and needs use according to picture signal, and applies the driving signal to these nozzles.Systems control division divides the integrated operation of control ink-jet recording apparatus 10.

Ink-jet recording apparatus involved in the present invention is not limited to be applied to the device of recording text and image on paper, for example facsimile machine, copying machines, printer, multi-function device, as the tape deck of work station output device etc.For example, also can be applicable on polymeric membrane, glass etc. to spray colored ink is used for display etc. with manufacturing filter.

That is, " recording medium " of the present invention is not limited to paper P, but comprises OHP sheet material for example, the substrate etc. of wiring pattern to be formed etc. thereon.And " image " of the present invention also needs not to be general pattern (text, picture, photo etc.), but comprise can be by impacting the dot pattern (wiring pattern) that ink droplet obtains on recording medium etc.

And fluid to be sprayed is not limited to printing ink especially.For example, ink-jet recording apparatus involved in the present invention can be applied in the common spray apparatus that is used for various commercial Application, for example spray slicken solder to be formed for the projection of installation elements in substrate, spraying in substrate has dynamo-electric glimmering luminous solution to form electrolumnescent display panel etc.

In a word, in possible ink-jet recording apparatus of the present invention, translator unit comprises the conveyer belt that twines around at least two rollers, loopback partly comprises the reverse band that twines around at least two rollers, and ink-jet recording apparatus also comprises: first separating part, it separates recording medium from conveyer belt, be used for recording medium is sent to reverse band from conveyer belt; Second separating part, it separates recording medium from reverse band, be used for recording medium is sent to conveyer belt from reverse band; And the 3rd separating part, it separates recording medium from conveyer belt, so that discharging.

In another possible ink-jet recording apparatus of the present invention, translator unit comprises the conveyer belt that twines around at least two rollers, loopback partly comprises reverse drum, and ink-jet recording apparatus also comprises: first separating part, it separates recording medium from conveyer belt, be used for recording medium is sent to reverse drum from conveyer belt; Second separating part, it separates recording medium from reverse drum, be used for recording medium is sent to conveyer belt from reverse drum; And the 3rd separating part, it separates recording medium from conveyer belt, so that discharging.

According to said structure, because be provided with first separating part, second separating part and the 3rd separating part, so can fast recording medium be separated with reverse band or reverse drum from conveyer belt.Therefore, can avoid the decline of productivity ratio when duplex printing.

In ink-jet recording apparatus of the present invention, oppositely band can rotate with the speed identical with conveyer belt, and oppositely band along with the direction rotation of the direction of rotation of recording medium when conveyer belt transmits, so that recording medium is sent to conveyer belt.

Perhaps, in ink-jet recording apparatus of the present invention, oppositely drum can rotate with the speed identical with conveyer belt, and oppositely drum along with the direction rotation of the direction of rotation of recording medium when conveyer belt is carried, so that recording medium is sent to conveyer belt.

According to said structure because conveyer belt and oppositely band or oppositely drum rotate with identical speed, so when transferring recording medium print image can with conveyer belt or oppositely band or oppositely drum friction.Therefore, can not cause the picture quality defective.

In ink-jet recording apparatus of the present invention, second separating part can comprise the idler roller that changes reverse band curvature.

According to said structure, recording medium separates from reverse band by the position that changes idler roller.Therefore, can make the simple in structure of second separating part.

In ink-jet recording apparatus of the present invention, second separating part can comprise disengaging pawl.

According to said structure, because recording medium separates from reverse band or reverse drum by disengaging pawl, so can separate reliably.

In ink-jet recording apparatus of the present invention, recording medium is sent to the position of reverse band from conveyer belt can be different from the position that reverse band is sent to conveyer belt with recording medium.

In ink-jet recording apparatus of the present invention, recording medium is sent to the position of reverse drum from conveyer belt can be different from the position that reverse drum is sent to conveyer belt with recording medium.

According to said structure, because recording medium hands over to the position of reverse band or reverse drum from conveyer belt different from reverse band or the reverse position that hands over to conveyer belt of rousing with recording medium, so can not have the longer problem of path that makes recording medium, and recording medium can be transmitted back to conveyer belt fast.Therefore, can avoid the loss of productivity ratio when duplex printing.

In ink-jet recording apparatus of the present invention, when many recording mediums when oppositely being with, oppositely the rotation direction of band can be after the end of first recording medium be by second separating part but the front end of second recording medium changes to rightabout before near second separating part.

According to said structure, many recording mediums can be overturn rapidly, and not change its order.Therefore, the loss of productivity ratio in the time of can avoiding duplex printing.

Ink-jet recording apparatus of the present invention can comprise can the identification record medium oppositely with on the identification division of position.

According to said structure, can control the upset cycle of being undertaken reliably by reverse band.Therefore, can avoid the loss of productivity ratio when duplex printing reliably.

According to the present invention with above-mentioned any form, a kind of ink-jet recording apparatus can be provided, the picture quality variation that it can avoid when duplex printing the friction owing to print image to cause, and can avoid productivity ratio to reduce.

Claims (11)

1. ink-jet recording apparatus, it forms image by ink jet print head on recording medium, and this ink-jet recording apparatus comprises:

Translator unit, the one side of described recording medium is attached to it, and this translator unit is sent to described ink jet print head with recording medium, and described translator unit comprises the conveyer belt that twines around at least two rollers; And

The loopback part, being formed with the record images medium on the another side is transmitted on this loopback part from described translator unit, the described one side of recording medium is attached on the described loopback part, and described loopback part supplies to described translator unit once more with recording medium, thereby make the described another side of recording medium can be attached on the translator unit, described loopback partly comprises the reverse band that twines around at least two rollers

Described reverse band along with rotate in the direction of the direction of rotation of recording medium when conveyer belt transmits so that recording medium is sent to described conveyer belt.

2. ink-jet recording apparatus according to claim 1 is characterized in that, described ink-jet recording apparatus also comprises:

First separating part, it separates recording medium from described conveyer belt, be used for recording medium is sent to described reverse band from conveyer belt;

Second separating part, it separates recording medium from described reverse band, be used for recording medium is sent to described conveyer belt from reverse band; And

The 3rd separating part, it separates recording medium from described conveyer belt, so that discharge.

3. ink-jet recording apparatus according to claim 2 is characterized in that, described second separating part comprises the idler roller that changes described reverse band curvature.

4. ink-jet recording apparatus according to claim 2 is characterized in that, described second separating part comprises disengaging pawl.

5. according to each described ink-jet recording apparatus in the claim 2 to 4, it is characterized in that recording medium is sent to the position of described reverse band from described conveyer belt different from the position that described reverse band is sent to described conveyer belt with recording medium.

6. ink-jet recording apparatus according to claim 2, it is characterized in that, attached to described when oppositely being with, the rotation direction of described reverse band is after the end of first recording medium is by described second separating part and the front end of second recording medium is changed into rightabout before near this second separating part at many recording mediums.

7. ink-jet recording apparatus according to claim 6 is characterized in that, also comprise can discern described oppositely with on many recording mediums at least one the identification division of position.

8. ink-jet recording apparatus, it forms image by ink jet print head on recording medium, and this ink-jet recording apparatus comprises:

Translator unit, the one side of described recording medium is attached to it, and this translator unit is sent to described ink jet print head with recording medium, and described translator unit comprises the conveyer belt that twines around at least two rollers; And

The loopback part, being formed with the record images medium on the another side is transmitted on this loopback part from described translator unit, the described one side of recording medium is attached on the described loopback part, and described loopback part supplies to described translator unit once more with recording medium, thereby make the described another side of recording medium can be attached on the translator unit, described loopback comprises that partly one oppositely rouses, and described ink-jet recording apparatus also comprises:

First separating part, it separates recording medium from described conveyer belt, be used for recording medium is sent to reverse drum from conveyer belt;

Second separating part, it separates recording medium from described reverse drum, be used for recording medium is sent to conveyer belt from reverse drum; And

The 3rd separating part, it separates recording medium from described conveyer belt, so that discharge.

9. ink-jet recording apparatus according to claim 8, it is characterized in that, described reverse drum rotates with the speed identical with described conveyer belt, and described reverse drum along with rotate in the direction of the direction of rotation of recording medium when conveyer belt transmits so that recording medium is sent to described conveyer belt.

10. ink-jet recording apparatus according to claim 8 is characterized in that, described second separating part comprises disengaging pawl.

11. each described ink-jet recording apparatus in 10 is characterized in that recording medium is sent to the position of described reverse drum from described conveyer belt different from the position that described reverse drum is sent to described conveyer belt with recording medium according to Claim 8.

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