KR20130027651A - Touch pannel and driving thereof - Google Patents

Abstract

PURPOSE: A touch panel and a driving device are provided to be strong from external noise without affecting a resistance value by comprising a sensing pattern and a wiring pattern with a single layer by using transparent conductive wiring. CONSTITUTION: A transparent conductive pattern is formed on a substrate. A touch panel driving unit(200) includes a signal input/output unit, a signal processing unit, and a timing control unit. The touch panel driving unit is formed on the substrate. The touch panel driving unit is connected to the transparent conductive pattern. The touch panel driving unit is formed in parallel with the transparent conductive pattern on the substrate.

Description

Touch panel and its driving device {TOUCH PANNEL AND DRIVING THEREOF}

The present invention relates to a touch panel and a device for driving the same. More particularly, the present invention relates to a touch panel for sensing a DC component drop and a device for driving the same.

The touch panel is an input device that allows a user's command to be input by selecting instructions displayed on a screen such as an image display device by a human hand or an object.

To this end, the touch panel is provided on the front face of the image display device to convert a contact position in direct contact with a human hand or an object into an electrical signal. Accordingly, the instruction content selected at the contact position is received as an input signal.

Since the touch panel can replace a separate input device connected to an image display device such as a keyboard and a mouse, its use range is gradually expanding.

As a method of implementing a touch panel, a resistive film type, a light sensing type, and a capacitive type are known. The capacitive touch panel converts the contact position into an electrical signal by detecting a change in capacitance formed by the conductive sensing pattern when the human hand or an object comes into contact with another sensing pattern or ground electrode. .

Here, in order to clearly determine the contact position on the contact surface, the sensing pattern may include first sensing patterns (X patterns) formed to be connected in a first direction and second sensing patterns formed to be connected in a second direction ( Y patterns).

1 is an exploded plan view of a conventional touch panel.

The touch panel 10 includes a transparent substrate 11, first sensing patterns 12, first insulating layers 13, and second sensing patterns 14 sequentially formed on the transparent substrate 11. The metal patterns 15 and the second insulating layer 16 are included.

The first sensing patterns 12 are formed to be connected in a first direction on one surface of the transparent substrate 11. For example, the first sensing patterns 12 may be formed on the upper surface of the transparent substrate 11 to be closely arranged in a regular pattern such as a diamond pattern.

The first sensing patterns 12 may be configured of a plurality of X patterns formed such that the first sensing patterns 12 positioned in one column having the same X coordinate are connected to each other.

In addition, the first sensing patterns 12 may include a pad 12a to be electrically connected to the metal patterns 15 in units of columns. The pads 12a of the first sensing patterns 12 may be alternately provided on the upper side and the lower side in units of columns, or may be provided on both the upper side and the lower side.

The second sensing patterns 14 are formed on the first insulating layer 13 to be connected in a second direction, and cross the first sensing patterns 12 so as not to overlap the first sensing patterns 12. It is arranged as a family register. For example, the second sensing patterns 14 are formed to be in close contact with the first sensing patterns 12 in the same diamond pattern, and the second sensing patterns 14 positioned in one row having the same Y coordinate are connected to each other. It may be composed of a plurality of Y patterns formed to be.

In addition, the second sensing patterns 14 may include pads 14a to be electrically connected to the metal patterns 15 in units of rows. The pads 14a of the second sensing patterns 14 may be alternately provided at the left and right sides in rows, or may be provided at both the left and right sides.

Meanwhile, the first and second sensing patterns 12 and 14 and the first insulating layer 13 are formed of a transparent material. That is, the first and second sensing patterns 12 and 14 are formed of a transparent electrode material such as indium tin oxide (hereinafter referred to as ITO), and the first insulating layer 13 is formed of a transparent insulating material.

Each of the sensing patterns 12 and 14 of the unit is electrically connected to a position detection line (not shown) so that the contact position detection signal is supplied to a driving circuit not shown.

When the hand or the object of the touch panel 10 shown in FIG. 1 contacts, the contact position toward the driving circuit via the first and second sensing patterns 12 and 14, the metal patterns 15, and the position detecting line. The change in capacitance is delivered. Then, the contact position is grasped by the change of the capacitance converted into an electrical signal by the X and Y input processing circuit (not shown) or the like.

However, the conventional touch panel must have respective ITO patterns for X and Y, thereby increasing the thickness of the touch panel. In addition, since capacitive changes generated by a touch such as a hand are accumulated several times, touch detection is possible, and thus, capacitive changes should be detected as a high number of frequencies. To this end, complex computational and statistical processing is required.

In addition, since the difference between the electrical signals before and after the touch is extremely minute, the wiring resistance is affected, and therefore, a metal wiring such as the metal pattern 15 is required to maintain the low resistance. An additional mask process is needed to form this metal pattern 15.

In addition, the touch detection of the conventional touch panel is highly dependent on the resistance value, and there are many difficulties in increasing the touch recognition sensitivity because it is sensitive to noise.

In the conventional touch panel, a separate substrate is prepared, the touch panel IC is mounted on the substrate, and then attached to the touch panel by a method such as thermocompression bonding. Such a mounting structure of the touch panel IC has a problem of being vulnerable to noise because the wiring length between the touch panel IC and the sensing patterns is long.

The present invention uses a transparent conductor wiring to form a sensing pattern and a wiring pattern in a single layer, which is not affected by resistance values, is robust against external noise, and provides a high recognition sensitivity and a driving device thereof. To provide.

In addition, the present invention integrates the touch panel into the display device in the In cell / On cell method to implement an integrated, and by enabling the integrated control of the touch panel integrated display device from one drive IC, It provides a way to improve the degree of freedom and reduce the size.

The present invention also provides a method that can simplify the manufacturing process for the touch panel and reduce the manufacturing cost.

The present invention also provides a touch panel and a driving device thereof capable of minimizing noise generation in the touch panel.

A touch panel and a driving apparatus thereof according to an embodiment of the present invention include a substrate, a transparent conductive pattern formed on the substrate, and a touch panel driver formed on the substrate and connected to the transparent conductive pattern.

The touch panel and its driving apparatus according to the present invention are not affected by the resistance value, are robust to external noise, and can provide high recognition sensitivity.

In addition, by implementing the sensing pattern and the wiring pattern on the substrate as a single layer using transparent conductor wiring, the manufacturing process can be reduced, the manufacturing cost can be greatly reduced, and the yield in the manufacturing process can be greatly improved. Can be.

In addition, by integrating the touch panel into the display device in an in cell / on cell manner, the integrated touch panel can be integrated into the display device and the integrated control of the touch panel can be controlled from a single driving IC, thereby increasing the degree of freedom in designing the instrument. And the size can be reduced.

In addition, the length of the wiring connecting the touch panel driver and the transparent conductive pad may be minimized to minimize noise generated by the wiring.

1 is a view showing a touch panel according to the related art.
2 is a schematic diagram illustrating a touch panel and a driving device according to an embodiment of the present invention.
3 is a schematic diagram illustrating a touch panel and a driving device according to an embodiment of the present invention.
4 is a diagram illustrating a touch detection circuit according to an embodiment of the present invention.
5 is a diagram illustrating input and output signal waveforms of a touch detection circuit according to an exemplary embodiment of the present invention.
6 is a cross-sectional view for describing a touch panel according to an exemplary embodiment of the present invention.
7 is a cross-sectional view for describing a touch panel according to another exemplary embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, except to exclude other components unless otherwise stated.

Also, the terms " part, "" module, " and " module" in the specification mean units for processing at least one function or operation, Can be.

Throughout the specification, when a part is "connected" to another part, this includes not only a case where the part is directly connected, but also a case where another system is connected in the middle.

2 and 3 are views illustrating a touch panel and a touch panel driver for controlling driving of the touch panel and sensing contact of a contact means according to an embodiment of the present invention.

The touch panel 100 includes a substrate 160, a plurality of transparent conductive pads 110, and a touch panel driver 200.

The substrate 160 is not particularly limited as long as it is transparent. Specifically, transparent inorganic substrates such as glass and quartz may be used, or flexible transparent substrates such as plastic may be used. Examples of the flexible transparent substrate include a transparent substrate such as polyethylene terephthalate, polyethylene naphthalate, polyethylene sulfone, polycarbonate, polystyrene, polypropylene, polyester, polyimide, polyetheretherketone, , Polyetherimide, acrylic resin, olefin maleimide copolymer, norbornene resin, etc. may be used alone or in combination of two or more.

The plurality of transparent conductive pads 110 are disposed in a matrix form on the substrate 160. The transparent conductive pad 110 is implemented by a transparent conductor such as ITO, and each transparent conductive pad 110 is also connected to the touch panel driver 200 through a transparent conductor wire such as ITO. One side of the transparent conductor wire is connected to the transparent conductive pad 110 and extends in the direction in which the touch panel driver 200 is located, and the other side thereof is connected to the touch panel driver 200. The transparent conductor wiring may be formed to pass between the transparent conductive pads 110 so that the length connecting the transparent conductive pad 110 and the touch panel driver 200 is minimized.

The touch panel driver 220 is positioned on the same surface as the transparent conductive pad 110. For example, in FIG. 2, the touch panel driver 220 is formed on the substrate 160 in parallel with the transparent conductive pad 110. The touch panel driver 200 includes a signal input / output unit 130, a signal processor 140, and a timing controller 150. Although not shown in FIG. 2, the touch panel driver 200 may further include memory means for temporarily storing touch positions. The touch panel driver 200 may be implemented in the form of an integrated circuit (IC) chip.

The signal input / output unit 130 may include a plurality of sensing switches 120 corresponding to the transparent conductive pads 110 having a matrix form. Although not shown in the drawings all connection relationships, each of the transparent conductive pad 110 may be connected to the sensing switch (SW1 ~ SW16), respectively, through a transparent conductor wiring such as ITO. For example, the conductive pads 110 positioned in one row and one column of the touch panel 100 are electrically connected to each other through the sensing switch SW1 and the transparent conductor wiring, and the conductive pads 11 positioned in the two rows and two columns are sensed. It is electrically connected to the switch SW6 via a transparent conductor wiring.

2 and 3 do not need to implement a wiring pattern with metal wiring because it senses a touch at a time by monitoring a DC component drop irrespective of a resistance value, and provides high signal-to-noise ratio (SNR) performance. This provides a simple structure and high sensitivity compared to the prior art. In addition, as the metal wiring pattern may be removed on the touch panel, the bezel regions located at both sides of the terminal may be removed or minimized. Therefore, there is an effect that the size of the display screen can be further expanded in the terminal having the same size.

The signal processor 140 controls a signal input through the signal input / output unit 130 and processes a signal output from the signal input / output unit 130 to sense a touch.

The timing controller 150 provides timing information to the signal processor 140 to control data input timing and monitoring timing of the sensing switch 120.

4 is a diagram illustrating a touch detection circuit according to an embodiment of the present invention.

The touch detection circuit may be implemented by the sensing switch 120 corresponding to each of the transparent conductive pads 110.

The sensing switch 120 includes a first switch 121, a second switch 122, a first capacitor C1, and a second capacitor C2. Here, C1 and C2 are reference numerals referring to capacitors and capacitances. On the other hand, a virtual capacitor "Ct" is formed between the touch means A, such as a finger to contact, and the transparent conductive pad 110.

The first switch 121 and the second switch 122 may be implemented as TFTs, but may also be implemented as any three-terminal switches connected as shown in FIG. 3. Hereinafter, the TFT will be described by way of example.

An input signal is applied to the input terminal In1 to the first switch 121, and a gate signal is sequentially applied to the gate terminal G1 in a pulse form. At this time, the potential at the transparent conductive pad 110 is determined by the action of the capacitances C1 and C2. Here, C1 and C2 are designed to about 10fF to 300fF, Ct can be freely designed by adjusting the distance, the opposing area, etc. of the touch means and the conductive pad 50. Preferably, Ct is selected from a value of 2 to several hundred times larger than C1 to C, and may be designed, for example, from tens of fF (femto F) to several tens of pF (pico F).

C1 and C2 may be separately installed outside the TFT, and may be implemented with internal capacities naturally occurring during the TFT production process.

When the gate signal of the first switch 121 is a pulse signal provided alternately between VH and VL, the signal output to the first output node Out1 corresponding thereto is applied as the gate signal of the second switch 122. . The second switch 122 outputs the second output signal to the second output node Out2 by reflecting the C1 and C2 capacities.

At this time, when the contact means A is in contact with the transparent conductive pad 110 to generate the virtual capacitance Ct, the second output signal Out2 outputs the second output signal in which the capacitance Ct is reflected. do.

Specifically, when the polarity of the gate signal of the gate terminal G1 is changed by the capacitance component formed between the source and the drain of the TFT, the output signal causes a drop in the direct current component. In an embodiment of the present invention, the touch of the contact means A is sensed by using the DC component drop value at this time.

The drop in direct current components before and after touch is not affected by resistance and other noise because there are no variables related to resistance. In addition, touch sensing is possible through at least one monitoring, and C1, C2, and Ct can be designed appropriately to increase the difference between DC component drop values before and after touch, thereby providing high sensitivity and signal-to-noise ratio.

4 illustrates an embodiment in which two capacitances C1 and C2 are installed, but an additional capacitance may be further installed to control the touch sensitivity and the DC component drop value. In addition, an additional TFT may be added, and it is also possible to remove the TFT corresponding to the second switch 122.

5 is a diagram illustrating input and output signal waveforms of a touch detection circuit according to an exemplary embodiment of the present invention.

When the on voltage applied to the gate G1 of the first switch 121 is referred to as "VH" and the off voltage is referred to as "VL", the voltage difference resulting from the on / off is the value obtained by subtracting VL from VH. When the first switch 121 is turned on by applying a voltage having a size of “V1” to the input terminal In1 of the first switch 121 and applying a VH to the gate terminal G1, the transparent conductive material is turned on. When no touch occurs on the pad 110, the voltage measured at the output terminal Out1 is "V2" as in the waveform of "Out1-A".

When the charge signal TFT 42 is turned off by applying "VL" to the gate terminal G1 after a predetermined time, the DC component of the voltage measured at the output terminal Out1 of the first switch drops. At this time, the DC component drop generated by C1 and C2 on the condition that the charge amount charged before and after the DC component drop is the same as Equation (1).

 [Equation 1]

Vdrop1 = (VH-VL) C1 / (C1 + C2) (DC voltage drop before touch)

On the other hand, the waveform labeled "Out1-B" is a waveform of the voltage measured at the output terminal Out1 when a touch input approaching the finger 25 with respect to the transparent conductive pad 110 occurs. Other conditions are the same as above, but in this case, since the capacitance Ct is formed between the finger A and the transparent conductive pad 110, the DC component drop when the touch input is generated in the waveform of Out1-B is expressed by Equation 2 same.

&Quot; (2) "

Vdrop2 = (VH-VL) C1 / (C1 + C2 + Ct) (DC voltage drop after touch)

Referring to FIG. 5 and Equations 1 and 2, the DC component drop value after the touch is small, and thus the generation of the touch can be easily understood.

As described above, the drop of the DC component appearing before and after the touch is not affected by resistance and other noise since there is no variable related to resistance. In addition, touch sensing is possible through at least one monitoring, and C1, C2, and Ct can be designed appropriately to increase the difference in DC component drop value, thereby providing high sensitivity and signal-to-noise ratio.

Referring to Equations 1 and 2, since the difference in the DC component drop voltage value is proportional to the difference between VH and VL, it is also possible to adjust the sensitivity by adjusting the pulse of the gate signal.

Out2-A and Out2-B are examples of the current value of the output terminal Out2 of the second switch 122, and it can be seen that they have a waveform similar to that of Out1-A and Out1-B, respectively.

The first output voltages Out1-A and Out1-B applied to the gate of the second switch 122 are greatly amplified into current signals by the transistor characteristics to generate the second output signals Out2-A and Out2-B. Such operation of the second switch 122 improves the touch recognition sensitivity.

Since the DC component drop is monitored, touch recognition of each of the matrix-type transparent conductive pads 110 is possible, so that the touch panel according to the exemplary embodiment of the present invention does not separate the X and Y layers and transparently touches one layer. It can be implemented by forming a pattern directly.

In addition, since the sensing switch 120 corresponding to each transparent conductive pad 110 independently performs touch sensing, it is possible to provide so-called multi-touch recognition for touching several points at the same time through a simple operation.

6 is a cross-sectional view for describing a touch panel according to an exemplary embodiment of the present invention. In more detail, FIG. 6 is a diagram illustrating that the substrate constituting the touch panel is attached to the upper substrate of the display device.

The display device generally has a structure in which the lower substrate 310 and the upper substrate 330 are stacked. In the case of LCD, the lower substrate 310 is an array substrate in which pixel electrodes and TFTs are arranged, and the upper substrate 330 is a color filter substrate for imparting R, G, and B colors. As shown in the figure, the liquid crystal is sealed between the lower substrate 310 and the upper substrate 330 to form the liquid crystal layer 340. Although not shown in the drawings, the LCD may further include a backlight, an upper and lower polarizers, an optical sheet, a protective sheet, and the like. In addition, when the display device is an LCD, the touch panel driver may be positioned above the transparent conductive pattern. In this case, a transparent conductive pattern is formed on the substrate, and an upper polarizer and a touch panel driver are formed above the transparent conductive pattern.

In the case of AMOLED, the lower substrate 310 is an array substrate, and the upper substrate 330 is an encapsulation substrate. In addition, an organic material is encapsulated between the lower substrate 310 and the upper substrate 330.

The touch panel according to an embodiment of the present invention is made of a light transmissive material, protects the substrate 350 and the touch panel on which the sensing pattern 322 and the wiring pattern 324 are formed, which are transparent conductors, from external impact, For example, a protective layer 320 and a tempered glass substrate 305 for printing characters may be provided.

The touch panel may be attached to the upper substrate 330 of the display device by using a transparent adhesive film (OCA). According to this, since the display device and the touch panel are integrated through a single bonding process, the process for manufacturing the touch screen can be simplified, and the overall thickness of the terminal can be made slimmer.

7 is a cross-sectional view for describing a touch panel according to another exemplary embodiment of the present invention. More specifically, it is a diagram showing that the touch panel according to another embodiment of the present invention is integrally formed with the display device.

The substrate 350 constituting the touch panel may be formed by being merged with the upper substrate 330 of the display device. That is, if the sensing pattern 322 and the wiring pattern 324 according to the present invention are directly formed on the upper surface or the lower surface of the color filter substrate of the LCD or the encapsulation substrate of the AMOLED, there is no need to manufacture the touch panel in a separate process. The manufacturing process can be simplified. In addition, the overall thickness of the terminal can be implemented more slim.

When the patterns 322 and 324 are formed on the lower surface of the upper substrate 330, the patterns 322 and 324 may be protected by the protection means (ie, the upper substrate and the protective sheet) of the display device in the case of non-mobile devices. Therefore, the use of the protective layer 320 and the tempered glass substrate 305 can be eliminated.

As described above, when the touch panel is embedded in the display device, the display device capable of touch input can be manufactured at a very low manufacturing cost. Furthermore, as described above, since the touch panel of the present invention detects the touch input in a manner that is not affected by the resistance value, the touch panel is resistant to noise generated in the display device and does not malfunction even in an electric field caused by a backlight or the like. Accordingly, the touch panel integrated display device as illustrated in FIGS. 6 and 7 may be more easily implemented.

In addition, the touch panel driver may be formed on the same surface as the transparent conductive pattern, thereby minimizing noise depending on the wire length, thereby improving touch recognition sensitivity. In addition, in the related art, a separate substrate such as FCB is used to mount the touch panel driver, but in the present invention, since it may be omitted, the structure may be simplified and the manufacturing cost may be reduced.

It is to be understood that the foregoing description of the disclosure is for the purpose of illustration and that those skilled in the art will readily appreciate that other embodiments may be readily devised without departing from the spirit or essential characteristics of the disclosure will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

It is to be understood that the scope of the present invention is defined by the appended claims rather than the foregoing description and that all changes or modifications derived from the meaning and scope of the claims and equivalents thereof are included in the scope of the present invention .

100: touch panel 110: transparent conductive pad
160: substrate 200: touch panel driver

Claims (1)

Board;
A transparent conductive pattern formed on the substrate; And
A touch panel driver formed on the substrate and connected to the transparent conductive pattern.
Touch panel and its driving device comprising a.

Images