CN102117158A - Touch screen - Google Patents

Abstract

The invention provides a touch screen, which comprises a working layer, a detection layer, an insulating layer, a substrate and a touch layer. The touch screen is characterized in that: the detection layer is a transparent conductive film; a detection electrode is arranged on the detection layer; and a ribbon resistance wire is arranged on the working layer, extended along one side edge of the working layer, turned back at a certain interval when reaching an edge and repeatedly bent to reach the other side edge of the working layer, and the two endpoints of the ribbon resistance wire form two electrodes. The touch screen is further improved in a way that: the ribbon resistance wire forms a plurality of areas with different touch accuracy values due to interval differences. Compared with the conventional resistive touch screen, the touch screen provided by the invention can meet the requirements of the different touch areas in the touch screen on touch accuracy by regulating the distribution density of the ribbon resistance wire in the touch areas, and reduces the resistance value of the whole ribbon resistance wire and correspondingly reduces the requirements of driving voltages of hand-held consumer terminals because the density of the ribbon resistance wire in a part of the touch areas is relatively lower.

Description

Touch-screen

Technical field

The present invention relates to a kind of touch-screen, relate in particular to a kind of electric resistance touch screen that can support single-point or 2 inputs.

Background technology

Existing touch-screen can be divided into usually according to its principle of work: resistance-type, condenser type, infrared, surface acoustic wave, electromagnetism and pressure sensing etc. are several.In surface acoustic wave technique, in touch screen surface level and vertical transmission, when panel was touched, the acoustic wave energy at place, contact was absorbed ultrasound wave by transducer, and sensor positions to the variation of sound wave and then to the contact.In infrared technique, light beam is by light emitting diode level and vertical transmission on touch screen surface, and when panel was touched, the light beam at place, contact was blocked, and photodetector detects this variation and then the contact is positioned.

In capacitive technologies, the material that touch-screen is coated one deck can stored charge, when panel was touched, a little charge attracted to the place, contact, positions by this electric charge of circuit measuring and then to the contact.

In resistive technologies, electric resistance touch screen is a kind of laminated film of multilayer, one deck glass or organic glass are arranged as basic unit, the surface scribbles one deck ITO (indium oxide) transparency conducting layer, be stamped one deck outside surface cure process, smooth scratch resistant plastics touch layer above again, its inside surface also scribbles one deck conductive layer (ITO or nickel gold), has many tiny transparent isolating points that they are separated insulation between the conductive layer of basic unit and touch layer.When the finger touches touch-screen, the two conductive layers of isolating mutually is just in the contact of place, contact at ordinary times, cause is the even voltage field of a conductive layer connection Y direction wherein, two-layer contact makes the voltage of another side conductive layer (detecting layer) become non-zero by zero, controller carries out the A/D conversion after detecting voltage, and thereby the magnitude of voltage that obtains compared the Y-axis coordinate that obtains the contact with reference voltage value, the even voltage field of in like manner connecting X-direction on the another side conductive layer can obtain the X coordinate of contact, thereby obtains contact position.

Even it is when on the sensing surface a plurality of target being arranged that there is a problem in above-mentioned resistive touch screen technology, touch-screen also only can be reported a point, promptly lacks the ability of following the trail of a plurality of contacts simultaneously.

Chinese patent application " 200810067470.4 " discloses a kind of multi-point electric resistance touch screen, it comprises the transparent medium supporting layer, upside is provided with the transparent medium touch layer, be provided with rectangle ITO conducting film in transparent medium supporting layer upper surface, be provided with isolated area between this rectangle ITO conducting film, the two ends of rectangle ITO conducting film are coated with electrode, draw by electrode outlet line, transparent medium touch layer lower surface is provided with rectangle ITO conducting film perpendicular to supporting layer upper surface rectangle ITO conducting film direction, be distributed with isolated area between rectangle ITO conducting film, the two ends of rectangle ITO conducting film are coated with electrode, are drawn by electrode outlet line.In this scheme two-layer conducting film all is divided into some rectangular conductive bars, each bus on every layer of conducting film is parallel to each other and insulate, be arranged in infall by multirow, multiple row by matrix form and form conduction region, come corresponding a plurality of tangible positions, but this scheme is thrown away and is had following defective: 1. can only identification in each conduction region a bit, only can recognize a bit in the time of in same conduction region is dropped in a plurality of contacts; 2. each root rectangular conductive bar two ends all need be provided with electrode, be connected with control circuit by lead-in wire, the increase of bus number can cause the increase of control circuit element, causes the growth of volume increase and manufacturing cost, the very few resolution that can influence touch-screen again of bus number.

In consumer electronics product, in hand-held products such as mobile phone, MID access terminals, the use of touch-screen is mainly imported by the click and the character of focus, the normal conditions focus is in the screen middle part, the pattern of focus all is bigger, and is lower to the position accuracy demand of clicking, and focus is at two ends up and down that screen is admired, pattern is then less relatively, thereby higher to the click location accuracy requirement; The operation of another aspect focusing has the operational requirements of multiple spot usually, as the amplification of image, rotation, page turning etc.; Character input then needs to gather the movement locus of the stroke of input, its essence also is the set that numerous single-points is operated, as look into touch-screen and support full frame input, because of user's input characters bigger, reduced accordingly the click location accuracy requirement, and some consumer electronics product delimited a character input field in the lower end of entire display screen, owing to the scope of input is dwindled, thereby higher to the click location accuracy requirement.

Existing scheme is the difference that input requires according to screen, and screen is divided into two parts, and as shown in Figure 1, A partly is a multiple point touching district, is made of resistive touch screen; B partly is a single-point touches district, is made of capacitance plate, and touch-screen is provided with two Petting Areas, make the user to select to use corresponding Petting Area according to different demands, realize the mutual supplement with each other's advantages of the touch-screen of two types, both had complete function, also saved cost simultaneously.

Adopt two class touch-screens to constitute the scheme of display screen,,, increased the difficulty that generates assembling, in addition, also brought the last complexity of computing because whole touch screen is made of two parts though certain advantage is arranged.

Therefore, be necessary to provide a kind of novel touch-screen, adopt one type touch-screen, satisfy the requirement that zones of different has the different operating precision.

Summary of the invention

The objective of the invention is to overcome the problem that existing electric resistance touch screen exists, a kind of touch-screen is provided, locate detected resistance value by the contact contact is positioned, and can support 2 touches.

For achieving the above object, the technical solution used in the present invention is as follows: a kind of touch-screen, comprise a working lining, a detection layers, an insulation course, a basic unit and a touch layer, it is characterized in that: described detection layers is a nesa coating, which is provided with a detecting electrode, and described working lining is provided with the ribbon resistance line, described ribbon resistance line extends along working lining one side, turn back with certain interval to the edge, bending arrives another side of working lining repeatedly, and its two-end-point forms two electrodes.

Further improve and be that described ribbon resistance line forms a plurality of different zones that touch precision that have because of the difference at interval.

Touch-screen provided by the invention is by adjusting the distribution density of ribbon resistance line at Petting Area, can realize that touch areas different in the touch-screen is to touching the requirement of precision, while is lower because of the density of the ribbon resistance line of subregion, reduce the resistance value of whole banded resistive conductor, reduced the requirement of the driving voltage of hand-held consumption terminal accordingly.

Description of drawings

Fig. 1 is the one-piece construction synoptic diagram of existing subregional touch-screen;

Fig. 2 is the structural representation of resistor-type touch-screen;

Fig. 3 is the circuit diagram of resistor-type touch screen control circuit;

Fig. 4 is the coordinate synoptic diagram of resistor-type touch-screen;

Fig. 5 a and 5b are be touched equivalent circuit diagrams 2 time of resistor-type touch-screen;

Fig. 6 is be touched a equivalent circuit diagram 3 time of resistor-type touch-screen;

Fig. 7, the 8th, resistance area ribbon resistance line of the present invention is realized the touch screen structure synoptic diagram that density distributes.

Fig. 9 is the touch-screen contact coordinate calculating chart of Fig. 7,8 ribbon resistance line density distributed architectures of the present invention.

Embodiment

In order to make purpose of the present invention, technical scheme and advantage clearer,, the present invention is further elaborated below in conjunction with embodiment.Should be appreciated that specific embodiment described herein only in order to explanation the present invention, and be not used in qualification the present invention.

With reference to figure 2, the resistor-type touch-screen comprises touch-screen and control circuit, described touch-screen comprises a workinglining 12 and adetection layers 14, separate (figure does not show) with a transparent insulating layer therebetween, described workinglining 12 is the rectangle nesa coating, etching has theribbon resistance line 122 of uniform resistivity on it, the electrode data1 of describedribbon resistance line 122 1 ends is located at 12 1 jiaos of working linings,ribbon resistance line 122 extends along workinglining 12 1 sides, turn back to the edge, form a serpentine configuration, form the electrode data2 of the other end to the place, diagonal angle of workinglining 12, describeddetection layers 14 is the rectangle nesa coating of uniform resistivity, is provided with a detecting electrode com.

Consult Fig. 3, the detecting electrode com of the two end electrodes data1 of describedribbon resistance line 122 and data2 and working lining all is connected with control circuit, described control circuit comprises a main control chip 22, one constant current source chip 24, one analog to digital converter AD, one shunt resistance Rt and two K switch 1 and K2, described constant current source chip 24 is respectively by K switch 1 and two end electrodes data1 with data2 corresponding be connected of K2 with theribbon resistance line 122 of described touch-screen, steady current is provided, the detecting electrode com ground connection of described touch-screen, described analog to digital converter AD one end is connected with described main control chip 22, the other end is connected between described constant current source chip 24 and K switch 1 and the K2, to detect to such an extent that voltage signal is passed described main control chip back, described main control chip 22 is connected its closure of control with described K switch 1 respectively with K2, described shunt resistance Rt is connected between described constant current source chip 24 and the detecting electrode com.

Described main control chip 22 difference folding K switch 1 and K2 are once in a sense cycle, thereby make described constant current source chip 24 be respectively theribbon resistance line 122 two end electrodes data1 and the data2 power supply of described touch-screen, the voltage of described analog to digital converter AD senses touch screen is also passed main control chip 22 back, because the resistance value of shunt resistance Rt and the current value that constant current source chip 24 provides are known, main control chip 22 can calculate the resistance value of touch-screen and then draw contact coordinate according to the detected magnitude of voltage of analog to digital converter AD.The effect of described shunt resistance Rt is the change in voltage scope that reduces touch-screen, for example, the electric current of constant current source chip 24 outputs is 5 milliamperes, touch screen electrode data1 is 100 ohm to 100 kilo-ohms to the resistance range between the detecting electrode com, shunt resistance Rt is 1000 ohm, then the detected voltage of analog to digital converter AD is just between 0.45 volt to 4.95 volts, if remove shunt resistance Rt, the detected voltage of analog to digital converter AD just between 0.5 volt to 500 volts, increases the requirement that main control chip 22 is handled.

The positioning principle of described touch-screen is as follows: with reference to figure 4, establishing describedribbon resistance line 122 resistance per unit lengths is M₀(ohm/meter), setting electrode data1 place is the true origin (0,0) of touch-screen, the coordinate position at the residing touch-screen of electrode data2 diagonal angle is (X₀, Y₀), in adjacent two sections of theribbon resistance line 122 bending back in the heart distance and the distance atribbon resistance line 122 and workinglining 12 edges be T₀, when having 2 A and B to be touched on the touch-screen, when electrode data1 place was measured, K switch 1 was closed in the control circuit at this moment, and K switch 2 is opened, and the equivalent circuit diagram of touch-screen is with reference to figure 5a, and establishing electrode data1 is M to the resistance between the electrode com₁, the length L of ribbon resistance line so from the A point to true origin₁Can be according to formula L₁=M₁/ M₀Obtain, with L₁Divided by (Y₀+ T₀), can obtain integral part is X_K1, fraction part is L₁₁, with reference to formula L₁=X_K1* (Y₀+ T₀)+L₁₁, then with L₁₁Divided by M₀, obtain Y_K1If, X_K1Be even number, the A coordinate of ordering is exactly (X so_K1* T₀, Y_K1); If X_K1Be odd number, the A coordinate of ordering is exactly (X so_K1* T₀, Y₀-Y_K1).

At this resistance M₁The resistance that equals resistance R 1 add resistance R 2, Ra1, Ra2 series connection again with resistance after resistance R b1 and Rb2 are in parallel because Ra1+Ra2＜＜R1 and Rb1+Rb2＜＜R1, the resistance after its parallel connection is also much smaller than resistance R 1, so M₁Approximate R1.

When electrode data2 place was measured, K switch 1 was opened in this moment control circuit, K switch 2 closures, and the equivalent electrical circuit of touch-screen is with reference to figure 5b, and establishing the resistance that electrode data2 measures to com is M₂, so from the B point to coordinate (X₀, Y₀) ribbon resistance line length L₂Can be according to formula L₂=M₂/ M₀Obtain, then with L₂Divided by (Y₀+ T₀), can obtain integral part is X_K2, fraction part is L₁₂, with reference to formula L₂=X_K2* (Y₀+ T₀)+L₁₂, then with L₁₂Divided by M₀Obtain Y_K2If X_K2Be even number, the B coordinate of ordering is exactly (X so₀-X_K2* T₀, Y₀-Y_K2), if X_K2Be odd number, the B coordinate of ordering is exactly (X so₀-X_K2* T₀, Y_K2).

At this resistance M₂The resistance that equals resistance R 3 add resistance R 2, Ra1, Ra2 series connection again with resistance after resistance R b1 and Rb2 are in parallel because Ra1+Ra2＜＜R3 and Rb1+Rb2＜＜R3, the resistance after its parallel connection is also much smaller than resistance R 3, so M₁Equal R3.Generally the resistance to electrode com can be controlled in below 300 ohm the square resistance of our ribbon resistance line in more than 300 ohm and contact from present practical application, the width of supposing ourribbon resistance line 122 is 0.5 millimeter, even be that the contact is nearribbon resistance line 122 two ends under limiting case, the conference of contact resistance brings 0.5 millimeter error to us, can ignore.In addition, in order further to reduce the resistance thatdetection layers 14 inserts in the equivalent electrical circuit, can coat the bus of low resistance around detection layers, described detecting electrode com is located on the described bus.

If have only a contact, we can come to measure from electrode data1 and data2 respectively equally as the method for front, obtain corresponding coordinate figure then, and the coordinate that obtains for twice is identical.

If there are three points to contact simultaneously, as shown in Figure 6, can not obtain the coordinate that C is ordered though measure all, yet the existence that C is ordered does not influence the correct measurement of other 2 A and B coordinate yet from electrode data1 and data2.Therefore, even there are more a plurality of points to exist, from the coordinate position of electrode data1 measuring resistance and the contact that calculates be onribbon resistance line 122 length the coordinate of the nearest contact of ionization electrode data1, from the coordinate position of electrode data2 measuring resistance and the contact that calculates be onribbon resistance line 122 length the coordinate of the nearest contact of ionization electrode data2.

If when the contact just in time is positioned at the horizontal connecting line of both sides up and down, certain error will occur with top formula, but owing to generally speaking, Y₀＞＞T₀, and the user can not touch the edge of touch-screen substantially yet, so therefore this error also can be ignored.

Be appreciated that workinglining 12 to be located at the touch layer inside surface of touch-screen anddetection layers 14 is located at substrate surface, as other embodiment, described workinglining 12 also can be located at substrate surface anddetection layers 14 is located at the touch layer inside surface.

In addition, the adjacent two sections Center Gap T inribbon resistance line 122 bending backs₀Fix, those skilled in the art is also clear, according to technical scheme provided by the invention, bends the adjacent two sections Center Gap in back with T asribbon resistance line 122₀, 2T₀, T₀, 2T₀Mode alternately, as long as when calculating the position coordinates of contact, consider this factor, all can use method provided by the invention to calculate the position coordinates of contact.

Please refer to the touch screen structure of Fig. 6, this touch-screen is made up of two parts, and one is the closeer zone ofribbon resistance line 40, is suitable for the higher operation of position accuracy demand, as the character input etc.; Another is thezone 20 that the ribbon resistance line distributes and to dredge, and the distribution of such touch-screen ribbon resistance line and aforementioned difference are that adjacent two sections Center Gap is with T₀Change has taken place, as long as consider this factor when calculating the position coordinates of contact, all can use the method for introducing previously to calculate the position coordinates of contact.Be appreciated that the interval T that the ribbon resistance line distributes₀Be the key factor that touches precision, interval T₀More little, it is high more to touch precision.

Please refer to touch screen structure shown in Figure 7, compare this touch-screen of Fig. 6 and form, comprise two highprecision manipulation districts 30,40 by three parts, and a low precision operational zone 20.The calculating of its position coordinates also only needs to examine the adjacent two ribbon resistance line Center Gap T of filter₀Variation get final product.

For Fig. 7, touch screen structure shown in Figure 8, as long as arranging of the resistive conductor of eachsubregion 20,30,40 is uniformly at interval, the resistance of the unit length of each subregion resistive conductor also is identical simultaneously.The calculating of touch point coordinate position also can be adopted following method except that said method.

See also shown in Figure 9ly, in this manner, handle the relatively simple volume production that also helps simultaneously.We can measure the resistance value that a bit arrives origin position on this screen arbitrarily, and in order to obtain its locus, we need be converted into coordinate figure with resistance value.

The space coordinates that we are defined as follows, its vertical maximum coordinates is Yt, horizontal maximum coordinates is Xt, we can simply obtain the ordinate Y of the horizontal resistive conductor of each root from the relation of physical arrangement, but we need know the resistance value of the end positions of each root lateral resistance line to initial point, in the processing procedure of reality, we can measure the resistance value of every lateral resistance line end positions to initial point one by one.

When calculating the Y coordinate of any one contact point, we only need read the resistance value of this contact point to initial point, such as this resistance value just between a0 and two end points of a1 between the resistance value of initial point, we just can obtain the ordinate of this point so.

The computing method of horizontal ordinate are also fairly simple, for example our contact point T still be in (a0, on line segment a1), its resistance value to initial point is Rt, simultaneously we have known that the resistance value at two ends is Ra0 and Ra1, and horizontal ordinate separately 0 and Xt.So just have following equation to set up:

$\frac{x}{\mathrm{Ra}0-\mathrm{Rt}}=\frac{\mathrm{Xt}-0}{\mathrm{Ra}0-\mathrm{Ra}1}$Formula 1

The horizontal ordinate of contact point T is exactly so:

$x=\frac{\mathrm{Xt}-0}{\mathrm{Ra}0-\mathrm{Ra}1}\×(\mathrm{Ra}0-\mathrm{Rt})$Formula 2

In this example, from distributed architecture: Ra0 is greater than Ra1.But at two resistive conductors of next-door neighbour up and down of this line, the resistance value of left side end points is less than the resistance value of the right end points, the coordinates computed value time, just need do corresponding adjustment so, supposes that Ra0 is less than Ra1.

Then horizontal ordinate x is exactly:

$x=\frac{\mathrm{Xt}-0}{\mathrm{Ra}1-\mathrm{Ra}0}\×(\mathrm{Rt}-\mathrm{Ra}0)$Formula 3

But from the result of formula 3 and formula 2, horizontal ordinate x can represent with formula 2 in fact:

$x=\frac{\mathrm{Xt}-0}{\mathrm{Ra}0-\mathrm{Ra}1}\×(\mathrm{Ra}0-\mathrm{Rt})$

Those skilled in the art are also clear, in resistive touch screen structure provided by the invention, as long as store the form of ribbon resistance wire shaped, resistance and coordinate corresponding relation in the main control chip of system, the ribbon resistance line of arbitrary shape distributes and all can determine the coordinate position of contact by tabling look-up, and obtains contact coordinate by tabling look-up.

In the process of calculating touch-screen, the resistance that control circuit records from first end, main control chip can one obtain corresponding contact coordinate by tabling look-up, the resistance that records from second end, main control chip can two obtain corresponding contact coordinate by tabling look-up, and can finish the location of single-point or 2 touches by this.

Be appreciated that electrode data1 and data2 also can be located at the same side of workinglining 12,ribbon resistance line 122 arrives the electrode data2 that turns back along the edge again behind workinglining 12 opposite sides by the electrode data1 bending of setting out repeatedly.

The present invention is by adjusting the distribution density of ribbon resistance line at Petting Area, can realize that touch areas different in the touch-screen is to touching the requirement of precision, while is lower because of the density of the ribbon resistance line of subregion, reduce the resistance value of whole banded resistive conductor, reduced the requirement of the driving voltage of hand-held consumption terminal accordingly.

The above only is preferred embodiment of the present invention, not in order to restriction the present invention.All any modifications of being done within the spirit and principles in the present invention, be equal to and replace and improvement etc., all should be included within protection scope of the present invention.

Claims (10)

1. touch-screen, comprise a working lining, a detection layers, an insulation course, a basic unit and a touch layer, it is characterized in that: described detection layers is a nesa coating, which is provided with a detecting electrode, described working lining is provided with the ribbon resistance line, and described ribbon resistance line extends along working lining one side, turns back with certain interval to the edge, bending arrives another side of working lining repeatedly, and its two-end-point forms two electrodes.

2. a kind of touch-screen according to claim 1 is characterized in that: described ribbon resistance line is a plurality of zones with different touch precision because of difference at interval forms.

3. touch-screen according to claim 2 is characterized in that: described touch-screen comprises the Petting Area of two high precision Petting Areas and intermediate distribution one low precision thereof.

4. touch-screen according to claim 1 is characterized in that: described working lining is located at the touch layer inside surface, and described detection layers is located at substrate surface.

5. according to the described touch-screen of arbitrary claim in the claim 1, it is characterized in that: described working lining is located at substrate surface, and described detection layers is located at the touch layer inside surface.

6. a touch-screen comprises a touch-screen and a control circuit, and described touch-screen comprises a working lining, a detection layers, an insulation course, a basic unit and a touch layer, and described control circuit comprises one first analog to digital converter and a main control chip, it is characterized in that:

Described detection layers is a nesa coating, which is provided with a detecting electrode;

Described working lining is provided with the ribbon resistance line, and the working lining edge is located at described ribbon resistance line two ends, and the ribbon resistance line is covered with whole working lining with definite shape;

Described main control chip selectivity forms the loop with a power turn-on and when touch-screen is touched by described detecting electrode respectively with the two ends of described ribbon resistance line; And

Described main control chip obtains the resistance value of described touch-screen and determines contact position according to resistance value by described first analog to digital converter.

7. a kind of touch-screen according to claim 6 is characterized in that: the side of working lining is located at the two ends of described ribbon resistance line, and center section is bent into parallel lines repeatedly with certain interval and distributes on working lining.

8. touch-screen according to claim 7 is characterized in that: described ribbon resistance line is a plurality of zones with different touch precision because of difference at interval forms.

9. touch-screen according to claim 6 is characterized in that: the position of the contact ordinate vertical with the ribbon resistance line can be determined according to the interval at the place of the resistance value that records.

10. according to claim 6 and 9 described touch-screens, it is characterized in that: try to achieve with the geometric ratio formula with the resistance of ribbon resistance line two-end-point that the position of the contact abscissa of ribbon resistance line parallel can be by place, contact section.

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