KR20140010788A - Touch detecting apparatus for minimizing deadzone and method - Google Patents

Abstract

The present invention relates to a touch detection device. A touch panel includes a plurality of sensor pads which are made of transparent materials and arranged in a matrix form and arranges signal lines which electrically connect the sensor pads and a touch IC alternately from different sensor pad rows, thereby expanding the available touch area and minimizing the dead zone.

Description

TOUCH DETECTING APPARATUS FOR MINIMIZING DEADZONE AND METHOD}

The present invention relates to a device and a method for detecting a touch, and more particularly, to a touch detection device and a method for minimizing a dead zone.

The touch screen panel is an input device for inputting a user's command by touching with a human hand or other contact means based on the content displayed by the image display device.

To this end, the touch screen panel is provided on the front face of the image display device to convert a contact position directly contacted by a human hand or other contact means into an electrical signal. Accordingly, the instruction selected at the contact position is received as an input signal.

1 is an exploded top view of an example of a conventional capacitive touch screen panel.

The conventional touch screen panel 1 includes a transparent substrate 2, a first sensor pattern layer 3, a first insulating layer layer 4, a second sensor pattern layer 5, and a first layer formed sequentially on the transparent substrate 2. 2, the insulating film layer 6 and the metal wiring 7 are included.

The first sensor pattern 3 is formed to be connected in a transverse direction on one surface of the transparent substrate 2. For example, the first sensor pattern 3 may be formed in a regular pattern in which a plurality of diamond shapes are lined up on the transparent substrate 2.

The first sensor pattern 3 may be formed of a plurality of Y patterns formed so that the first sensor patterns 3 positioned in one row having the same Y coordinate are connected to each other, and the position detection line 7 is provided in units of rows. Connected with

The second sensor pattern 5 is formed to be connected in the column direction on the first insulating film 4, and is alternately disposed with the first sensor pattern 3 so as not to overlap the first sensor pattern 3. For example, the second sensor pattern 5 may be formed in the same diamond pattern as the first sensor pattern 3, and the second sensor patterns 5 positioned in one column having the same X coordinate are connected to each other. In addition, the second sensor pattern 5 is connected to the position detection line 7 in units of columns.

Meanwhile, the first and second sensor patterns 3 and 5 are made of a transparent conductive material such as indium tin oxide (ITO), and the first insulating film 4 is made of a transparent insulating material.

The sensor patterns 3 and 5 of the unit are respectively electrically connected to the position detection line 7 to supply a contact position signal to a driving circuit (not shown) or the like.

When a hand or an object comes into contact with the touch screen panel 1 illustrated in FIG. 1, the capacitance of the capacitance according to the contact position is moved to the driving circuit side via the first and second sensor patterns 3 and 5 and the position detection line 7. Change is communicated. And the contact position is grasped | ascertained as the change of capacitance is converted into an electrical signal by X and Y input processing circuits (not shown) etc.

However, the conventional touch screen panel 1 must have an ITO pattern in each layer for X and Y, and an insulating layer must be provided between the X layer and the Y layer, thereby increasing thickness. In addition, since capacitive changes generated by touch are accumulated several times, touch detection is required to detect capacitive changes at a high frequency. This requires complex computational and statistical processing.

In addition, since the difference between the electrical signals before and after the touch is extremely minute, it is affected by the wiring resistance, which requires metal wiring to maintain low resistance. This metal wiring thickens the bezel at the edges of the touch screen and creates an additional mask process.

The problem to be solved by the present invention is to provide a touch detection device and a touch detection method that can detect the correct touch area and touch coordinates.

In addition, since a plurality of signal wires connecting the plurality of sensor pads and the touch driver (touch IC) are disposed only in one direction, the dead zone is expanded on one side of the touch panel.

According to an aspect of the present invention, there is provided a touch detection apparatus, including: a touch panel including a plurality of sensor pads of a transparent material disposed in a matrix form; And a switch and a driving capacitor electrically connected to the plurality of sensor pads through a signal wire, and outputs a voltage change in response to an alternating voltage applied to the driving capacitor after charging and floating the sensor pad using the switch. A driving unit; A level shift detector for outputting a level shift value based on a difference between the output voltage changes before and after the touch; And a touch information processor configured to calculate a touch area using the level shift value, and calculate touch coordinates using the touch area, wherein the sensor pads positioned in a specific column of the touch panel are one or more sensor pads. Grouping is grouped into a plurality of pad groups to include, and the direction of the signal wiring arrangement between the pad groups are alternately alternately formed.

Thus, according to the touch detection apparatus according to the embodiment of the present invention, there is an effect that can extend the touchable area and minimize the dead zone in the touch panel of the same size.

1 is an exploded plan view of a conventional touch screen panel.
2 is an exploded plan view of a touch detection apparatus according to an embodiment of the present invention.
3 is a block diagram illustrating a configuration of a touch detection apparatus according to an embodiment of the present invention.
4 is a circuit diagram illustrating a touch detector according to an exemplary embodiment of the present invention.
5 is an exemplary waveform diagram of a touch detection unit according to an embodiment of the present invention.
6 is a block diagram of a level shift detection unit according to an embodiment of the present invention.
7 is a block diagram of a touch information processing unit according to an embodiment of the present invention.
8 is a schematic view for explaining a structure of a memory in which information on a sensor pad according to an embodiment of the present invention is stored.
9 is a flowchart illustrating a touch detection method according to an embodiment of the present invention.
10 is a plan view illustrating a configuration of a touch panel according to another exemplary embodiment of the present invention.
11 is a plan view illustrating a configuration of a touch panel according to still another embodiment of the present invention.

The terms used in this specification will be briefly described and the present invention will be described in detail.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. Also, in certain cases, there may be a term selected arbitrarily by the applicant, in which case the meaning thereof will be described in detail in the description of the corresponding invention. Therefore, the terms used in the present invention should be defined based on the meanings of the terms and the contents throughout the present invention, rather than the names of the simple terms.

When an element is referred to as "including" an element throughout the specification, it is to be understood that the element may include other elements, without departing from the spirit or scope of the present invention. In addition, the terms "... unit", "module", etc. described in the specification mean a unit for processing at least one function or operation, which may be implemented in hardware or software or a combination of hardware and software. . When a part is "connected" to another part, it includes not only a direct connection but also a connection with another system in the middle.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. 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 order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, a touch detection apparatus according to an embodiment of the present invention will be described in detail with reference to FIGS. 2 and 3. FIG.

2 is an exploded plan view of a touch detection apparatus according to an embodiment of the present invention, and FIG. 3 is a block diagram illustrating a configuration of a touch detection apparatus according to an embodiment of the present invention.

2 and 3, the touch detection apparatus according to the present embodiment includes a touch panel 100, a driving device 200, and a circuit board 20 connecting the two.

The touch panel 100 includes a plurality of sensor pads 110 formed on a substrate 15 such as glass or plastic film of transparent material and a plurality of signal wires 120 connected thereto.

The plurality of sensor pads 110 may be, for example, rectangular or rhombic, but is not limited thereto. The sensor pad 110 may be implemented in a polygonal shape of a uniform shape. The sensor pads 110 may be arranged in a matrix form of substantially adjacent polygons.

Each signal wire 120 has one end connected to the sensor pad 110 and the other end extending to the bottom edge of the substrate 15. The line width of the signal wire 120 may be designed to be quite narrow, on the order of several tens to several tens of micrometers.

The sensor pad 110 and the signal wire 120 may be formed of indium-tin-oxide (ITO), antimony tin oxide (ATO), indium-zinc-oxide (IZO), carbon nanotube (CNT), and graphene. It can be made of a transparent conductive material.

The sensor pad 110 and the signal wiring 120 can be formed simultaneously by, for example, laminating an ITO film on the substrate 15 by a sputtering method or the like and then patterning the same using an etching method such as photolithography.

The sensor pad 110 and the signal wire 120 may be covered with a transparent insulating film 10.

The driving device 200 for driving the touch panel 100 may be formed on a circuit board 20 such as a printed circuit board or a flexible circuit film, but is not limited thereto and may be directly mounted on a part of the substrate 15. have. The driving device 200 may include a touch detector 210, a touch information processor 220, a memory 230, a controller 240, and the like, and may be implemented as one or more integrated circuit (IC) chips.

The touch detector 210 is connected to the signal wire 120, receives a signal from the controller 240, drives circuits for touch detection, and outputs a voltage corresponding to the determination result of the touch detection. The touch detector 210 may include a plurality of switches and capacitors connected to the sensor pad 110.

In addition, the touch detector 210 converts, amplifies, or digitizes the difference in the voltage change of the sensor pad 110 and stores the difference in the memory 230, and may include an amplifier and an analog-digital converter.

The touch information processor 220 processes the digital voltage stored in the memory 230 to generate necessary information such as whether or not it is touched, a touch area, and touch coordinates.

The control unit 240 controls the touch detection unit 210 and the touch information processing unit 220 and may include a micro control unit (MCU), and may perform predetermined signal processing through the firmware.

The memory 240 stores the digital voltage based on the difference in the voltage change detected by the touch detector 210 and predetermined data used for touch detection, area calculation, and touch calculation or data received in real time.

As described above, the touch detector 210, the touch information processor 220, the memory 230, and the controller 240 may be separated from each other, or two or more components may be integrated and implemented.

A detailed embodiment of the touch panel and the touch detector and its operation will be described in detail with reference to FIGS. 4 and 5.

FIG. 4 is a circuit diagram illustrating a touch detection unit according to an embodiment of the present invention, and FIG. 5 is an exemplary waveform diagram of a touch detection unit according to an embodiment of the present invention.

Referring to FIG. 4, the touch detector 210 includes a plurality of transistors 211, a plurality of parasitic capacitors Cp, a plurality of driving capacitors Cdrv, a plurality of common voltage capacitors Cvcom, and a plurality of switching operations. The level shift detector 212 is connected to the sensor pad 110 through the signal line 120. The transistor 211, the parasitic capacitor Cp, the driving capacitor Cdrv, the common voltage capacitor Cvcom, and the level shift detection unit 212 may be grouped one per sensor pad 110 and the signal wire 120. The sensor pad 110, the signal wire 120, the transistor 211, the parasitic capacitor Cp, the driving capacitor Cdrv, and the common voltage capacitor Cvcom are collectively referred to as a “touch cell”. The touch cell is a concept including a case where each component is electrically connected to the level shift detector 212 by a multiplexer. For convenience, the same reference numerals are used for capacitors and their capacitances.

The transistor 211 is a field effect transistor, for example, a control signal Vg may be applied to a gate, a charging signal Vb may be applied to a source (or drain), and a drain (or source) may be a signal wire ( 120). The control signal Vg and the charging signal Vb may be applied by the control of the controller 240. Instead of the transistor 211, other devices capable of switching may be used.

The parasitic capacitance Cp refers to the capacitance accompanying the sensor pad 110 and is a kind of parasitic capacitance formed by the sensor pad 110, the signal wire 120, and the like. The parasitic capacitance Cp may include any parasitic capacitance generated by the touch detector 210, the touch panel, and the image display device.

The common voltage capacitance Cvcom is a capacitance formed between the common electrode (not shown) and the touch panel 100 of the display device when the touch panel 100 is mounted on the display device (not shown). A common voltage Vcom such as a square wave is applied to the common electrode by the display device. The common voltage capacitance (Cvcom) may also be included in the parasitic capacitance (Cp) as a parasitic capacitance, and the common voltage capacitance (Cvcom) is included in the parasitic capacitance (Cp) unless otherwise mentioned for CVcom. Will be explained.

The driving capacitance Cdrv is a capacitance formed in a path for supplying an alternating voltage Vdrv alternately at a predetermined frequency for each sensor pad 110. The alternating voltage Vdrv applied to the driving capacitor Cdrv is preferably a square wave signal. The alternating voltage Vdrv may be a clock signal having the same duty ratio, but different duty ratios. The alternating voltage Vdrv may be provided by a separate alternating voltage generating means, but may also use the common voltage Vcom.

Meanwhile, in FIG. 4, the touch capacitance Ct represents the capacitance formed between the sensor pad 110 and a touch input tool such as a user's finger when the user touches the sensor pad 110.

In the future, the cell may be disposed at a position where the user cannot touch or may have a cell having electrical characteristics that are not always touched. The "reference cell" may exist physically, but may be a virtual channel having only data values.

Referring to FIG. 5, the controller 240 may apply the charging signal Vb and the control signal Vg to the source and gate of the transistor 211, respectively.

First, the case in which the touch input tool is not touched to the sensor pad 110 will be described. After the charge signal Vb rises to 5V, for example, the control signal Vg applied to the gate of the transistor 211 rises from the low voltage VL to the high voltage VH, and when the charge section T1 starts, the transistor (211) is turned on. Accordingly, the sensor pad 110 is charged with the charging signal Vb, and the output voltage Vo becomes the charging voltage Vb. The parasitic capacitor Cp, the driving capacitor Cdrv, and the common voltage capacitor Cvcom are also charged with the charge voltage Vb. In the charging period T1, since the transistor 211 is turned on, the alternate voltage Vdrv does not affect the output voltage Vo.

Next, when the sensing period T2 starts while the control signal Vg goes from the high voltage VH to the low voltage VL, the transistor 211 is turned off, the touch capacitor Ct, the parasitic capacitor Cp, and the driving. The capacitor Cdrv and the common voltage capacitor Cvcom are isolated in a charged state. In this case, in order to stably isolate the charged signal, the input terminal of the level shift detector 212 may have a high impedance.

The state in which the charges charged in the sensor pad 110 and the like are isolated is called a floating state. At this time, when the alternating voltage Vdrv applied to the driving capacitor Cdrv increases from 0 V to 5 V, for example, the voltage level of the output voltage Vo of the sensor pad 110 is instantaneously raised, The level of the output voltage Vo drops instantaneously. This rise or fall in voltage levels is sometimes called "kick-back."

When there is no touch on the sensor pad 110, that is, when only the driving capacitor Cdrv and the parasitic capacitor Cp are connected to the sensor pad 110, the output voltage Vo by these capacitors Cdrv and Cp is applied. The voltage variation of ΔVo is

. Where VdrvH and VdrvL are the high level voltage and the low level voltage of the alternating voltage Vdrv, respectively.

Next, a case in which the touch input tool is touched on the sensor pad 110 will be described. When a touch occurs, a touch capacitor Ct is formed between the sensor pad 110 and the touch input tool. Accordingly, the capacitor connected to the sensor pad 110 may include a touch capacitor (in addition to the driving capacitor Cdrv and the parasitic capacitor Cp). Ct) is added. As in the above-described method, the voltage variation ΔVo of the sensor pad 110 due to these three capacitors Cdrv, Cp, and Ct in the sensing period T4 through the charging period T3 is expressed by Equation 2 below. Lose.

Comparing [Equation 1] and [Equation 2], since the touch capacitance (Ct) is added to the molecular item of [Equation 2], the voltage fluctuation (ΔVo) when there is a touch is the touch is It is small compared to the voltage fluctuation ΔVo in the absence, and the difference depends on the touch capacitance Ct. Thus, the difference of the voltage fluctuation (DELTA) Vo before and behind a touch is called "level shift."

In general, the capacitance C of the capacitor is proportional to the area A of the electrode and proportional to the distance d between the electrodes, that is, C = εA / d (ε is the dielectric constant). Therefore, as the touch area increases, the touch capacitance Ct increases. 5, when the variation of the alternating voltage Vdrv applied to the driving capacitor Cdrv occurs in the sensing periods T2 and T4 during which the transistor 211 is turned off, A voltage change occurs. By using such a relationship, whether or not the touch and the touch area may be calculated using the difference in the voltage variation ΔVo of the output voltage Vo before and after the touch.

Referring back to FIG. 4, the level shift detector 212 detects a level shift generated by an alternating voltage Vdrv in a floating state. In detail, the level shift detection unit 212 may include a change ΔVo of the output voltage Vo at the sensor pad 110 when no touch occurs and a change variance of the output voltage Vo at the sensor pad 110 when the touch occurs. [Delta] Vo) can be measured to detect whether a level shift has occurred. That is, the potential of the sensor pad 110 is raised or lowered by the applied alternating voltage Vdrv. The voltage level variation in the case of a touch is smaller than the voltage level variation in the case of no touch. Therefore, the level shift detector 212 detects the level shift by comparing the output voltage Vo levels before and after the touch. In addition, the level shift detector 212 may acquire a touch signal based on the difference between the voltage variations.

The level shift detection unit 212 will now be described in more detail.

6 is a block diagram of a level shift detection unit according to an embodiment of the present invention.

6, the level shift detector 212 according to the present embodiment includes an amplifier 2121, a buffer 2122, a reference value provider 2123, an analog-to-digital converter (ADC) 2124, A shift output section 2125 and a correction section 2126. [ The level shift detector 212 may omit at least one of these elements as necessary. In addition, the level shift detection unit 212 may include a voltage to frequency converter (VFC), a flip-flop, a latch, and a transistor. (Transistor), a thin film transistor (Thin Film Transistor), it may be configured by combining at least one of a comparator.

The amplifier 2121 amplifies the output voltage Vo of the touch cell. The amplifier 2121 may be a single input amplifier or a differential amplifier. In the case of a differential amplifier, the two inputs of the differential amplifier may be the output voltage Vo of the touch cell and the reference voltage Vr of the reference cell, and the amplifier 2121 amplifies the difference between the two voltages Vo and Vr. To print.

The buffer unit 2122 buffers the output voltage Vo. The buffer unit 2122 may perform an amplification operation of the amplifier 2121.

As mentioned above, the touch cell includes the sensor pad 110, the signal wiring 120, the transistor 212, the driving capacitor Cdrv, and the parasitic capacitor Cp shown in FIG. 4, and when there is a touch. Refers to a conventional touch cell further including a touch capacitor Ct, and the reference cell refers to a touch cell that does not include a touch capacitor Ct because a user's touch does not occur.

The voltage difference (ΔV = Vr-Vo) between the output voltage Vo of the touch cell and the reference voltage Vr of the reference cell refers to the voltage difference when the alternating voltage Vdrv is the high voltage VdrvH. (ΔV) is equal to the difference (level shift) of the voltage variation ΔVo before and after the touch, and may be expressed as Equation 3 below.

Where ΔVr = Vr-Vb and ΔVo = Vo-Vb.

When the touch capacitance Ct is zero, that is, the voltage difference ΔV at the metric is 0, and as the touch capacitance Ct increases, the voltage difference ΔV also increases. Since the touch capacitance Ct is proportional to the touch area A and inversely proportional to the distance d between the touch means and the sensor pad 110, that is, since Ct = εA / d (ε is the dielectric constant), the distance d Is constant, the touch area A and the touch capacitance Ct are linearly proportional. Therefore, it can be understood that the larger the voltage difference? V, the larger the touch area A is.

The reference value provider 2123 may provide the reference voltage Vr to the amplifier 2121 in place of the reference cell. The reference value provider 2123 stores the digital value of the reference voltage Vr in the memory 230 for each sensor pad 110, reads the digital value, and provides an analog reference voltage Vr to the differential amplifier through digital-to-analog conversion. can do. When the amplifying unit 2121 is a single input amplifier, the reference value providing unit 2123 may include a subtracting circuit and may output a value obtained by subtracting the output value of the amplifying unit 2121 from the reference voltage Vr . Alternatively, the reference value provider 2123 may provide the reference voltage Vr directly to the analog-digital converter 2124.

The analog-to-digital conversion section 2124 can convert the analog output values of the buffer section 2122 or the amplification section 2121 into digital signals and output them. For example, the analog-to-digital converter 2124 divides the output voltage of the buffer unit 2122 into four sections, and assigns two bits of digital values in order of magnitude to each section. However, setting the digital value to 2 bits is just one example, and other bits such as 4 bits, 8 bits, and 10 bits may be possible.

The level shift output section 2125 outputs a level shift value corresponding to a voltage difference (? V) before and after the touch based on the digital value received from the analog-digital conversion section 2124. When the analog-to-digital conversion section 2124 directly outputs the level shift value, the analog-to-digital conversion section 2124 performs the same function as the level shift output section 2125.

On the other hand, since the value of the touch capacitance (Ct) is located in the denominator in [Equation 3], the level shift value, which is the voltage difference (ΔV) before and after the touch, increases as the value of the touch capacitance (Ct) increases but does not have perfect linearity. Do not. The corrector 2126 corrects the non-linearity of the touch cell to correct the output value of the analog-to-digital converter 2124 or the output value of the level shift output unit 2125 so that the area according to the touch and the output value may be linearly related. do.

As an example, the compensator 2126 may include a table in which the level shift value and the touch capacitance Ct value correspond one-to-one, and extract and export the touch capacitance value Ct corresponding to the level shift value. Can be.

As another example, the correction unit 2126 may divide the level shift value by intervals, generate a linear function in each interval, and may match the output value of the generated linear function with respect to each voltage difference? V.

As another method, linearity can be imparted between the voltage difference ΔV and the touch area A by applying a predetermined weight to the output of each voltage difference ΔV.

On the other hand, even if the relationship between the voltage difference ΔV and the touch area A is not a perfectly linear proportion, if the slope is sufficiently gentle to provide sufficient accuracy for calculating the area, it is treated as being substantially linear proportional, and the voltage is not treated without special correction. The difference ΔV can be used to calculate the touch area A. In this case, the corrector 2126 may be omitted from the level shift detector 212. [

The level shift value or its correction value is stored in the memory 230.

As described above, according to the level shift detection unit 212 according to the embodiment of the present invention, since the level shift before and after the touch is in linear relation with the touch area A, using this linear proportional relationship, The detection device can detect a very accurate touch area and touch coordinates.

7 to 9, the operation of detecting the touch area and the touch coordinates by the touch detection apparatus according to the embodiment of the present invention will be described in detail.

FIG. 7 is a block diagram of a touch information processing unit according to an embodiment of the present invention, FIG. 8 is a schematic view for explaining a structure of a memory in which information about a sensor pad according to an embodiment of the present invention is stored, FIG. 4 is a flowchart illustrating a touch detection method according to an embodiment of the present invention. FIG.

As illustrated in FIG. 7, the touch information processor 220 according to an exemplary embodiment of the present invention may include a touch cell detector 221 for detecting a touch cell in which a touch occurs, and a touch area for calculating a touch area of a touch cell in which a touch occurs. The calculator 222 includes a touch coordinate calculator 223 that calculates touch coordinates using the calculated touch area. The touch information processor 220 may be implemented in software or firmware to operate in conjunction with an MCU.

The memory 230 illustrated in FIG. 8 may include, for example, a plurality of memory cells having addresses corresponding to touch cells, and each memory cell is amplified, digitized, and corrected by the level shift detector 212. The shift value ΔVD can be stored.

As described above, the level shift value DELTA VD stored in the memory 230 is linearly proportional to the touch area occupied by the sensor pad 110. [ Therefore, this level shift value [Delta] VD is treated the same as the touched digital area value. The level shift value ΔVD may have four values of 00, 01, 10, and 11, for example, when digitized to 2 bits. Here, 00 means no touch, and 11 means that the entire sensor pad 110 is touched and covered. As described above, the magnitude of the level shift value ΔVD corresponds to the magnitude of the touch area for one sensor pad 110.

8 shows memory cells of M11 to M54, which correspond to touch cells C11 to C54, respectively. If a touch occurs in the touch cells C11, C12, C21, C22, C34, and C44, memory cells M13, M14, M23, M24, M31, M32, M33, M41, and M42 corresponding to touch cells that have little or no touch. 00 is stored in M43, M51, M52, M53, and M54, and memory cells M11, M12, M21, M22, corresponding to touch cells C11, C12, C21, C22, C34, and C44 where touch is generated. In M34 and M44, digital values according to the contact area will be stored.

The touch information processor 220 may read the digital area values of the touch cells C11 to C54 from the memory 230 to determine the contact area and the contact location. For example, the center of gravity of the entire touch area of the touch cell other than 00 may be calculated as touch coordinates.

Also, when the touch information processor 220 groups non-00 touch cells into a plurality of groups, the touch information processor 220 may also detect areas and coordinates of the multi-touch. For example, as shown in FIG. 8, the first touch is generated over M11, M12, M21, and M22, and the second touch may be detected over M34 and M44.

Referring to FIG. 9, the touch detection method according to the present embodiment first detects the common voltage (Vcom) period of the display device on which the touch detection device is mounted (S100). The touch detection apparatus may include a separate circuit for detecting the common voltage Vcom period. Alternatively, the touch detection apparatus may provide information about the common voltage Vcom such as the period and the rising (or falling) edge point of the common voltage Vcom. It may be provided from a display device.

The touch detection apparatus avoids the rising edge and the falling edge of the common voltage Vcom and controls the timing of the alternate voltage Vdrv so that the rising edge and the falling edge of the alternating voltage Vdrv are generated in the high voltage state . In this way, it is possible to prevent the level shift caused by the alternating voltage Vdrv from being distorted by the common voltage Vcom.

As described above, the common voltage Vcom can be used as the alternating voltage Vdrv for touch detection. In this case, the rising edge and the falling edge of the common voltage Vcom are set to the turn-off state VL) state, the timing of the control signal Vg can be controlled. The touch detection apparatus raises the control signal Vg from the low voltage VL to the high voltage VH while the charge signal Vb is raised, thereby turning on the transistor 211 to charge the sensor pad 110 with the charge signal Vb. Charge to (S110).

Then, the touch detection apparatus lowers the control signal Vg from the high voltage VH to the low voltage VL for each touch cell to make the sensor pad 110 in a floating state. Thereafter, when the common voltage Vcom or the alternating voltage Vdrv rises from the low voltage VdrvL to the high voltage VdrvH, the output voltage Vo of the sensor pad 110 is measured to determine each sensor pad 110 in advance. Scan in order (S120).

The touch detection apparatus detects the level shift value DELTA VD by amplifying the output voltage Vo and analog-to-digital converting the variation (? Vo) of the output voltage (S130). The level shift value ΔVD corresponds to a difference in the voltage variation ΔVo before and after the touch. The detected level shift value ΔVD is recorded in the memory 230 corresponding to each touch cell.

It is determined whether the level shift value ΔVD is 0 (S140), and when it is 0, steps S110 to S130 are repeated (S140). That is, when the level shift value ΔVD is 0, the touch cell does not generate a touch and thus detects the level shift value ΔVD until a touch occurs.

If the level shift value ΔVD is not 0, the touch cell group including adjacent touch cells whose level shift value ΔVD is not 0 is extracted (S150). According to an embodiment of the present invention, since the sensor pads 110 are each implemented in an isolated matrix form, the sensor pads 110 provide a multi-touch sensing function. Therefore, when multi-touch occurs, it is necessary to group touch cells in which touch occurs in order to calculate respective touch areas and coordinates.

Next, the area of the touch area is calculated based on the level shift value ΔVD of the touch cell group (S160). As described above, since the level shift value ΔVD and the touch area are proportional to each other, the touch area may be calculated by summing the level shift value ΔVD in the touch cell group.

Next, the coordinates of the touch area are calculated from the calculated area of the touch area (S170). In the touch panel 100 according to the exemplary embodiment of the present invention, the sensor pad 110 has a polygonal shape with a uniform size, and is arranged in a matrix form. Therefore, each of the sensor pads 110 covers the display device in a state having a predetermined area and address. Therefore, the occupation area of the sensor pad 110 may be matched with the coordinates of the image display device.

If information on the touch occupancy area is calculated for each sensor pad 110 from the touch area calculated in step S170, the touch area distribution of the X-axis and Y-axis of the sensor pad matrix may be obtained. When the area center points of the X and Y axes are obtained based on the area distribution, touch coordinates corresponding to the center points of the entire touch area may be calculated. By using the structure of the touch panel 100 and the calculated touch area, touch coordinates can be calculated very accurately.

By repeating these steps (S110 to S170), it is possible to continuously detect whether the touch is made, the touch area and the touch coordinates.

Hereinafter, with reference to FIG. 10 and FIG. 11, the structure of the touch panel applicable to the touch detection apparatus of this invention is demonstrated in detail.

10 is a plan view for explaining the configuration of a touch panel according to another embodiment of the present invention, Figure 11 is a plan view for explaining the configuration of a touch panel according to another embodiment of the present invention.

10 and 11, the touch panel 100 includes a plurality of sensor pads 110 formed on a substrate such as glass or plastic film made of transparent material and a plurality of signal wires 120 connected thereto. do.

The plurality of sensor pads 110 may be, for example, rectangular or rhombic, but is not limited thereto. The sensor pad 110 may be implemented in a polygonal shape of a uniform shape. The sensor pads 110 may be arranged in a matrix form of substantially adjacent polygons.

Each signal wire 120 has one end connected to the sensor pad 110 and the other end extended to the bottom edge of the substrate 15 to be connected to the touch detection unit (not shown) of the driving device. The line width of 120) can be designed to be quite narrow, on the order of tens to tens of micrometers.

In this case, as shown in FIG. 2, when the signal wires 120 connected to the sensor pads 110 are all arranged in one direction (for example, right direction with respect to the sensor pads), the right edge or the left side The area where the touch sensing is not possible at the edge portion (ie, the dead zone) increases.

That is, the aforementioned dead zone increases when signal wirings are arranged in only one direction centering on a specific sensor pad column, and as the width of the dead zone increases, the bezel on the touch panel for covering the dead zone ( Bezel) also increases in size.

Accordingly, in the touch panel according to the present invention, a plurality of sensor pads included in a specific sensor pad column is grouped into a plurality of pad groups to include one or more sensor pads, and signal wiring arrangement directions between pad groups are provided. Are alternately formed, and the signal wiring arrangement directions of the sensor pads belonging to the same pad group are all the same.

For example, the sensor pads belonging to the first pad group arrange the signal wires 120 in the first direction (eg, to the right of the sensor pads), and the sensor pads belonging to the second pad group include the same. The signal wires 120 are disposed in the same direction in the second direction (for example, the left direction based on the sensor pad). Similarly, the sensor pads belonging to the third pad group arrange the signal wires 120 in the first direction. In this way, the signal wiring arrangement directions of the respective pad groups are alternately formed.

At this time, in order to minimize the dead zone of the left or right edge portion, it is preferable to equalize the number of signal wires arranged in the first direction and the second direction around the specific sensor pad row.

For example, suppose that there is a touch panel configured with a plurality of sensor pads in a 10 x 5 matrix form (see FIG. 10), 5 located at the top of the 10 sensor pads included in the first column is shown. The signal wires connected to the two sensor pads are arranged in the right direction with respect to the first row, and the signal wires connected to the other five sensor pads are arranged in the left direction.

FIG. 11 illustrates a case in which one sensor pad forms one pad group. As illustrated, the pad groups are alternately formed while alternately arranging signal wires.

The sensor pad 110 and the signal wire 120 may be formed of indium-tin-oxide (ITO), antimony tin oxide (ATO), indium-zinc-oxide (IZO), carbon nanotube (CNT), and graphene. It can be made of a transparent conductive material.

The sensor pad 110 and the signal wiring 120 can be formed simultaneously by, for example, laminating an ITO film on the substrate 15 by a sputtering method or the like and then patterning the same using an etching method such as photolithography.

The sensor pad 110 and the signal wire 120 may be covered with a transparent insulating film 10.

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 .

10: insulating film, 15: substrate,
20: circuit board, 100: touch panel,
110: sensor pad, 120: signal wiring,
200: drive unit, 210: touch detection unit,
212: transistor, 212: level shift detector,
2121: amplification unit, 2122: buffer unit,
2123: reference value providing unit, 2124: analog-to-digital conversion unit,
2125: level shift output unit, 2126:
220: touch information processor, 221: touch cell detector,
222: Touch Area Calculation Unit, 223: Touch Coordinate Calculation Unit,
230: memory, 240: control unit,

Claims (1)

A touch panel including a plurality of sensor pads of a transparent material disposed in a matrix form;
And a switch and a driving capacitor electrically connected to the plurality of sensor pads through a signal wire, and outputs a voltage change in response to an alternating voltage applied to the driving capacitor after charging and floating the sensor pad using the switch. A driving unit;
A level shift detector for outputting a level shift value based on a difference between the output voltage changes before and after the touch; And
A touch information processor configured to calculate a touch area using the level shift value, and calculate touch coordinates using the touch area;
The sensor pads positioned in a specific column of the touch panel are grouped into a plurality of pad groups to include one or more sensor pads, and the direction of arranging signal lines between the pad groups is alternately alternately formed. Touch detection device.

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