KR20160107792A - Touch detecting three dimensional display apparatus and method using sinusoidal voltage - Google Patents

Abstract

The present invention relates to a three-dimensional image display apparatus having a touch detecting device using a sinusoidal voltage, and a touch detecting method, for detecting a touch based on voltage fluctuation depending on a touch capacitance by using the sinusoidal voltage. According to one embodiment of the present invention, in a three-dimensional image display apparatus including a display panel for outputting a three-dimensional image having a left-eye image and a right-eye image and a parallax barrier formed thereon with a light-transmitting area and a light-blocking area when the three-dimensional image is zoomed in, wherein elements configuring the parallax barrier are formed with at least two layers, the three-dimensional image display apparatus having the touch detecting device is provided, in which the touch detecting device includes: a plurality of sensor pads for forming a touch capacitance; a driving unit for applying a sinusoidal voltage to each of the sensor pads; an amplifying unit having a first input end connected to an output of the sensor pad and a second input end for connecting a preset reference voltage; a first switch for connecting the output of the sensor pad and the first input end of the amplifying unit, and a second switch for controlling an electric potential between the first end and an output end of the amplifying unit; and a touch detecting unit for detecting a touch based on based on voltage fluctuation depending on the touch capacitance in the output end of the amplifying unit, wherein the first switch and the second switch are alternately switched on or off.

Description

TECHNICAL FIELD [0001] The present invention relates to a stereoscopic image display device and a touch detection method using a touch detection device using a sine wave voltage,

The present invention relates to a touch detection apparatus and method in a stereoscopic image display apparatus that detects a touch using a sine wave voltage, and more particularly, to a touch detection apparatus and method in a stereoscopic image display apparatus that detects touch by applying a sine wave voltage to a sensor pad Apparatus and method.

Recently, 3D technology has been developed to enable viewers to feel as if they are in a scene due to the development of display technology. In other words, the paradigm shifts with the development of 3D display with emphasis on high image quality in 2D display.

Currently developed 3D display methods can be divided into glasses type and non-glasses type. Passive Glasses Type and Shutter Glasses Type are typical glasses type. The polarizing glasses system is a system in which the display device outputs the left eye image and the right eye image at the same time, and the user uses the polarizing glasses to view the left eye image through the left eye and the right eye image through the right eye. This method is advantageous in that the display does not flicker and can reduce fatigue in the eye, but it has a disadvantage in that the image quality deteriorates due to the use of polarizing glasses. On the other hand, the shutter glass system sequentially reproduces the left-eye image and the right-eye image, and allows the user to view the reproduced image through the glasses which are alternately opened and closed by the left and right shutters. This method has a merit that the problem of lowering the image quality is relatively less, but it has a disadvantage that the display is flickering, which can give a lot of eye fatigue.

Lenticular lens method and parallax barrier method are typical examples of a method of realizing a non-eyeglass 3D display. 1 is a view for explaining the principle of a lenticular lens system. 1, in the lenticular lens system, a screen 12 having lenses arranged in a semicircular shape in cross section is disposed on the entire surface of the display panel 11, and a left-eye image and a right- Are respectively refracted through the screen 12 and directed toward the left and right eyes of the viewer. However, the lenticular lens system is disadvantageous in that it is difficult to manufacture, its price is high, and the wave pattern is felt in view of viewers due to the arrangement of the lenses. Therefore, the parallax barriers are relatively utilized in the non-eyeglass type 3D display.

2A is a view for explaining a 3D display device of a parallax barrier type. Referring to FIG. 2A, a parallax barrier 22 is disposed on the front surface of the display panel 21. The parallax barrier 22 has a plurality of line patterns. For example, the odd line (a) serves as a slit for blocking light emitted from the display panel 21, and the even line (b) serves to transmit light emitted from the display panel 21 as it is And can function as a slit. The display panel 21 displays a frame in which the left eye image L and the right eye image R are alternately arranged in the column direction. At this time, the left-eye image L and the right-eye image R are incident on the left and right eyes of the viewer by the parallax barrier 22, respectively. Accordingly, the viewer can feel a stereoscopic effect from the image. Thus, the parallax barrier system provides stereoscopic effect by the binocular parallax.

However, in such a parallax barrier system, since the gap between the slits constituting the barrier is fixed, a stereoscopic effect can be realized only for an image having a fixed resolution. That is, if the same image is enlarged or reduced, the left eye image and the right eye image are not properly blocked by the barrier, thereby causing no stereoscopic effect.

For example, a problem arises when the image frame emitted from the display panel 21 zooms in. In the present specification, the zoom-in means enlarging the information expressed by the unit pixel in the original image so that a plurality of pixels express the information.

2B shows a case where an image outputted from the display panel 21 is zoomed in 2 times.

The original image is composed of a left eye image and a right eye image alternately one pixel at a time. Referring to FIG. 2B, in the case of zooming in 2 times, a left eye image is displayed in two successive pixels, The right eye image is displayed on the pixel. However, since the width of the light shielding region and the light shielding region in the parallax barrier 22 does not change, some of the images for the left eye can not be blocked or transmitted properly and are incident on the right eye of the viewer. A part of the images can not be properly intercepted or transmitted, and the image is incident on the left eye of the viewer. As a result, the user can not feel a proper stereoscopic effect.

On the other hand, a touch screen panel is a device for inputting a command of a user by touching characters or graphics displayed on a screen of a video display device with a finger or other contact means, and is attached and used on a video display device. The touch screen panel converts a contact position that is touched by a human finger or the like into an electrical signal, and the converted electrical signal is used as an input signal.

As a method of implementing a touch screen panel, a resistive film type, a light sensing type, and a capacitive type are known. Among them, the capacitive touch panel converts the contact position into an electrical signal by sensing a change in the capacitance that the conductive sensing pattern forms with other peripheral sensing patterns or the ground electrode when a human hand or an object touches.

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

8, the touch screen panel 10 includes a transparent substrate 12 and a first sensor pattern layer 13, a first insulating layer 14, and a second sensor pattern layer 15, a second insulating film layer 16, and a metal wiring 17.

The first sensor pattern layer 13 may be connected on the transparent substrate 12 along the lateral direction and connected to the metal wiring 17 on a row-by-row basis.

The second sensor pattern layer 15 may be connected to the first insulating layer 14 along the column direction and alternately arranged with the first sensor pattern layer 13 so as not to overlap the first sensor pattern layer 13 . In addition, the second sensor pattern layer 15 is connected to the metal wiring 17 on a row basis.

When a human finger or a contact means is brought into contact with the touch screen panel 10, a change in capacitance according to the contact position is transmitted to the drive circuit side through the first and second sensor pattern layers 13 and 15 and the metal wiring 17 do. Then, the contact position is determined as the change in capacitance transferred is converted into an electrical signal.

However, the touch screen panel 10 must have a separate pattern of a transparent conductive material such as indium tin oxide (ITO) on each of the sensor pattern layers 13 and 15. The sensor pattern layers 13, 15, the thickness of the insulating layer 14 is increased.

In addition, since the touch detection can be performed by accumulating the changes of capacitance slightly generated by the touch several times, it is necessary to detect the capacitance change at a high frequency. In order to sufficiently accumulate the capacitance change within a predetermined time, a metal wiring is required to maintain a low resistance, which thickens the bezel at the edge of the touch screen and generates an additional mask process.

To solve this problem, a touch detection apparatus as shown in Fig. 9 has been proposed.

9 includes a touch panel 20, a driving device 30, and a circuit board 40 connecting the two.

The touch panel 20 includes a plurality of sensor pads 22 formed on a substrate 21 and arranged in the form of a polygonal matrix and a plurality of signal wirings 23 connected to the sensor pads 22.

Each signal wiring 23 has one end connected to the sensor pad 22 and the other end extending to the lower edge of the substrate 21. The sensor pad 22 and the signal wiring 23 can be patterned on the cover glass 50. [

The driving device 30 sequentially selects a plurality of sensor pads 22 one by one to measure the electrostatic capacitance of the corresponding sensor pad 22, thereby detecting whether or not a touch is generated.

In order to quickly and accurately respond to the touch operation in the touch detection apparatus shown in FIG. 9, it is necessary to control the noise generated at the touch and the parasitic capacitance generated between each sensor pad 22. The noise generated in the electrostatic capacitive touch-sensing device occurs when noise due to an external environment (e.g., LCD power supply noise), a sensor pad, a circuit board, a touch IC, etc. affect the adjacent sensor pad 22 do. In addition, the parasitic capacitance is caused by the capacitive coupling between the sensor pads 22, the manufacturing process, and the like, which adversely affects touch detection.

Such noise and parasitic capacitance may cause errors in touch recognition, resulting in a reduction in signal-to-noise (SNR) that determines the touch detection performance.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems of the prior art.

It is also an object of the present invention to detect whether or not a touch is detected based on a voltage variation according to a touch capacitance by using a sine wave voltage in a touch detection apparatus and a touch detection method in a stereoscopic image display apparatus.

According to an aspect of the present invention, there is provided a stereoscopic image display device including a display panel for outputting a stereoscopic image composed of a left eye image and a right eye image, Wherein the parallax barrier comprises two or more layers, and the plurality of sensor pads forming the touch capacitance include: A driver for applying a sinusoidal voltage to each sensor pad; An amplifier having a first input connected to an output of the sensor pad and a second input connected to a preset reference voltage; A first switch for connecting an output of the sensor pad and a first input terminal of the amplification unit; a second switch for controlling a potential between a first input terminal and an output terminal of the amplification unit; And a touch detection unit for detecting whether or not a touch is made based on a voltage variation at an output terminal of the amplification unit according to the touch capacitance, wherein the first switch and the second switch are alternately turned on or off, The stereoscopic image display device according to claim 1,

The first switch may be turned off when the instantaneous value of the sine wave voltage applied to each sensor pad reaches a maximum value.

The touch detection unit may detect the touch by measuring a maximum value of the voltage variation at a moment when the instantaneous value of the sine wave voltage applied to the sensor pad becomes a maximum value.

And a blocking unit for removing a frequency component that is not included in a predetermined threshold range based on the frequency of the sine wave voltage among the voltage levels at the output terminal of the amplifying unit.

The driving unit may apply the sinusoidal voltage to a conductive object disposed adjacent to the sensor pad.

The second switch may be turned on for a predetermined time at a time point when the instantaneous value of the sine wave voltage applied to each of the sensor pads becomes a minimum value, thereby setting a reference value for detecting whether or not the touch is detected.

According to another embodiment of the present invention, there is provided a method of driving a plasma display panel, comprising: applying a sinusoidal voltage to a sensor pad connected to a first input terminal of an amplifier; Blocking the connection between the output of the sensor pad and the first input of the amplifier when the instantaneous value of the sinusoidal voltage has a maximum value; And detecting whether or not the touch is detected on the basis of an output terminal voltage of the amplifier relative to a reference voltage applied to a second input terminal of the amplifier.

The step of applying the sinusoidal voltage may include applying the sinusoidal voltage to a conductive object disposed adjacent to the sensor pad.

Wherein the control unit disconnects the connection between the sensor pad and the first input terminal before the sine wave voltage application step and connects the first input terminal and the output terminal of the amplification unit to each other for a predetermined time, The step of initializing the amount of charge of the capacitance may be further included.

According to the touch detection apparatus and method in a stereoscopic image display apparatus implementing the stereoscopic image of the parallax barrier system of the present invention, not only the sine wave voltage is applied to the sensor pad, but also the frequency components of the sine wave voltage applied to the sensor pad It is possible to minimize influence of noise and parasitic capacitance caused by driving the touch screen panel by blocking other frequency components.

It should be understood that the effects of the present invention are not limited to the above effects and include all effects that can be deduced from the detailed description of the present invention or the configuration of the invention described in the claims.

1 is a view for explaining a 3D display method using a lenticular lens system.
2A and 2B are views for explaining a 3D display method of a parallax barrier system.
3A and 3B are views for explaining a stereoscopic image realization method according to an embodiment.
4A, 4B, 5A and 5B are views for explaining a stereoscopic image realizing method according to an embodiment.
6A and 6B are views showing the configuration of a parallax barrier in one embodiment.
7 is a diagram for explaining a method of enlarging a stereoscopic image output from a display panel according to an exemplary embodiment.
8 is an exploded plan view of an example of an electrostatic touch screen panel.
9 is an exploded plan view of a conventional touch detection device.
10 is a diagram illustrating a structure of a touch detection apparatus according to an embodiment of the present invention.
11 is a circuit diagram illustrating a touch detection unit according to an embodiment of the present invention.
12 is an exemplary waveform diagram of a touch detection unit according to an embodiment of the present invention.
13 is a waveform diagram illustrating a change in the output terminal voltage of the amplifying part according to a sinusoidal voltage when a touch is generated.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the accompanying drawings. 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.

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 term used in the present invention should be defined based on the meaning of the term, not on the name of a simple term, but on the entire contents of the present invention.

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 as well, without departing from the spirit or scope of the present invention. Also, the terms "part," " module, "and the like described in the specification mean units 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.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out 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.

3A and 3B are views for explaining a stereoscopic image display apparatus according to an embodiment of the present invention, and FIG. 3A is a sectional view of a stereoscopic image display apparatus.

3A and 3B, a stereoscopic image display apparatus according to an exemplary embodiment of the present invention includes a display panel 310 and a parallax barrier 320 disposed on one side (e.g., a front surface) thereof.

The display panel 310 outputs a multi-view image for a stereoscopic image. The multi-view image is an image of an object acquired from various viewpoints to display the image in three dimensions. Specifically, the display panel 310 outputs a frame in which the left-eye image L and the right-eye image R are alternately arranged in the first column direction (for example, in the column direction). The display panel 310 may include a liquid crystal display (LCD), a field emission display, a plasma display panel, or an electroluminescent display .

The parallax barrier 320 is configured to transmit light in one direction of the multi-view image output from the display panel 310 while blocking light in the other direction. Specifically, light in a direction that can be viewed in the left eye among lights projected on pixels constituting a stereoscopic image is transmitted, while light in a direction that can be viewed with the right eye is blocked. On the other hand, it is possible to transmit light in a direction that can be viewed with the right eye, while blocking light in a direction that can be viewed in the left eye. As a result, for one pixel, the viewer can view only one of the left eye or the right eye.

To do this, the parallax barrier 320 includes a plurality of electrodes 321 arranged in parallel with each other. Each of the electrodes 321 may be disposed in parallel with the longitudinal direction of the left eye image L and the right eye image R in the display panel 310, The width W1 of each electrode 321 may be equal to the width W2 of the left eye image L and the right eye image R that are basically outputted from the display panel 310, But it may not. Also, in the figure, there is no gap between the electrodes 321, but a minute gap may be formed between the electrodes 321.

A region corresponding to each electrode 321 may be implemented as a liquid crystal cell. That is, the parallax barrier 320 according to one embodiment includes a plurality of upper electrodes 321, a lower electrode (not shown) facing the upper electrodes 321, a lower electrode And a liquid crystal layer. Signals from the control circuit 330 may be input to the upper electrode 321 and the lower electrode. The control circuit 330 selectively applies or grounds the driving signal to the upper electrode 321. When a driving signal is inputted to the upper electrode 321, a potential difference is formed in relation to the opposing lower electrode, and the liquid crystal layer in the region is turned on to form a light transmitting region. Conversely, when the upper electrode 321 is grounded, the liquid crystal layer in the region is turned off to form a light shielding region. The electrodes 321 may be formed of a transparent electrode (for example, ITO or the like).

The image frame emitted from the display panel 310 is configured by alternately arranging the left eye image L and the right eye image R by pixels as shown in FIG. 3A. At this time, when the odd-numbered electrode 321a of the parallax barrier 320 is grounded, a region corresponding to the odd-numbered electrode 321a becomes a light blocking region, and a region corresponding to an even- All become light transmitting regions. The left eye image L and the right eye image R are transmitted or blocked by the parallax barrier 320, respectively, and are incident only on the left and right eyes of the viewer.

 According to the present invention, the light intercepting area and the light transmitting area of the parallax barrier are also changed by zooming in or out of the original image.

4A and 4B are views for explaining the operation of the stereoscopic image display apparatus according to the embodiment of the present invention.

FIG. 4A shows a state in which the original image of FIG. 3A is zoomed in two times, and FIG. 4B shows a state of the parallax barrier at this time.

Referring to FIG. 4A, the width of the left eye image L and the right eye image R is doubled as the original image displayed on the display panel 310 is zoomed in. For example, if the width of the left eye image (L) and the right eye image (R) in the original image are the same as the width of one pixel, the width of each image (L, R) Lt; / RTI > For example, when an image of 800 × 480 pixels size is zoomed in twice, the size of the image is 1600 × 960 pixels.

At this time, the signal applied to the electrode 321 of the parallax barrier 320 is changed. Specifically, the period in which the driving signal and the ground signal are applied to the respective electrodes 321 varies depending on the degree of zooming of the image. When the image is zoomed in N times, a drive signal or a ground signal is applied to the N electrodes 321 continuously. That is, a driving signal is continuously applied to the N electrodes 321, a ground signal is applied to the N electrodes 321, and the N electrodes 321 alternate to form the light transmitting region and the light blocking region . 4A, when the image is zoomed 2 times as much as the original image, a ground signal is input to the first electrode 321a and the second electrode 321b of the parallax barrier 320, And a driving signal is inputted to the third electrode 321c and the fourth electrode 321d to form a light transmitting region.

That is, as the image outputted from the display panel 310 is zoomed in N times, the width of the light transmitting area and the light blocking area of the parallax barrier 320 is N times as well, Is blocked or transmitted by the parallax barrier 320 and enters the left eye of the viewer. The N-fold magnified right eye image is correctly intercepted or transmitted by the parallax barrier 320 to enter the right eye of the viewer.

For this operation, it should be noted that the image has been zoomed N times the original image, which may be done by the control circuit 330 or another controller (not shown).

For example, if the original image having a resolution of 1024 x 768 pixels is displayed in an enlarged size of 2048 x 1536 pixels, it is recognized that the image has been enlarged twice, and then the electrode 321 of the parallax barrier 320 is driven The signal or ground signal is applied appropriately.

5A and 5B are diagrams showing a parallax barrier state in a state in which the original image shown in FIG. 3A is zoomed in four times. The width of the left eye image (L) and the right eye image (R) are respectively increased four times as long as the original image is zoomed by four times. Thus, in the electrode 321 of the parallax barrier 320, the ground signal and the driving signal are alternately applied to the four electrodes 321. For example, as shown in Figs. 5A and 5B, a ground signal is supplied from the first electrode 321a to the fourth electrode 321d, and from the fifth electrode 321e to the eighth electrode 321h A driving signal can be supplied.

That is, when the image is zoomed in four times, the respective light transmission areas and the light blocking areas are also adaptively enlarged four times, thereby preventing deterioration of the stereoscopic effect.

4 and 5 show only the case where the electrode 321 of the parallax barrier 320 is formed as one layer. However, in order to minimize the distance between the electrodes 321, each electrode is formed into two or more layers Or may be formed in a laminated form.

6A and 6B are views showing an example in which the electrode 321 of the parallax barrier 320 is implemented as two layers. FIG. 6A is a view showing an electrode state when the original image of FIG. 3A is zoomed in 2 times, and FIG. 6B is a view showing an electrode state when the original image of FIG.

6A and 6B, some of the electrodes 321, for example, odd-numbered electrodes 321a and 321c are formed in the first layer, and the even-numbered electrodes 321b and 321d are formed in the second layer . Although FIGS. 6A and 6B illustrate only two layers, they may be formed of three or more layers. Even when the electrodes 321 are formed in multiple layers, the signal application to the electrodes 321 according to the image zooming operation is the same. When the image is zoomed in 2 times, the ground signal and the driving signal can be alternately applied to the two electrodes as shown in FIG. 6A. In addition, when the image is zoomed in 4 times, the ground signal and the driving signal can be alternately applied to four electrodes successively as shown in FIG. 6B. This is the same as described with reference to Figs. According to the signal application, even when the electrodes 321 are formed in a laminated structure, the entire parallax barrier 320 can form a light blocking region and a light transmitting region similarly to the case of forming a single layer.

On the other hand, when the original image is zoomed in, the reference electrode 321 may be specified in the parallax barrier 320 according to the position of the reference point.

7 shows that the reference points may be different even if the original image is zoomed in at the same magnification.

For example, assume that the original image is enlarged and the upper left corner of the display panel 310 is enlarged to a reference point, as shown in FIG. 7 (a). If the leftmost image of the panel is the left eye image when the original image is displayed on the display panel 310, the image outputted from the leftmost of the display panel 310 in the enlarged image may be the left eye image. Therefore, in the parallax barrier, the leftmost electrode should be the reference electrode, and the signal applied to the electrode should not change with enlargement. For example, when the image is zoomed N times, either the drive signal or the ground signal should be applied to the electrodes constituting the parallax barrier N consecutively. The signal applied to the reference electrode is N It should not change before and after zooming in. It is preferable that the reference electrode is an electrode at an intermediate point among the group of consecutive electrodes including the corresponding electrode and the same signal being applied thereto or an electrode existing at a nearest position thereof.

With this operation, the reference point at which the image output from the display panel 310 is enlarged coincides with the reference point at which the width of the light transmitting area and the light blocking area formed by the parallax barrier is enlarged.

Similarly, as shown in FIG. 6B, when the image is enlarged with the reference point at the right upper end of the display panel 310, it is a starting point for specifying the Nth electrode among the electrodes constituting the parallax barrier The electrode should be the rightmost electrode.

In the case shown in FIGS. 6 (c) and 6 (d), the leftmost electrode and the rightmost electrode should be reference electrodes serving as starting points for specifying the Nth electrode, respectively, for the same reason.

6E shows a case where the original image is enlarged with reference to a specific point (for example, a center point) of the display panel 310. At this time, It will be the reference electrode.

Hereinafter, a touch detection apparatus and method in a stereoscopic image display using a sine wave voltage according to an embodiment of the present invention will be described.

10 is a diagram illustrating a structure of a touch detection apparatus according to an embodiment of the present invention.

Referring to FIG. 10, the touch detection apparatus includes a touch screen panel 100 and a driving apparatus 200.

The touch screen panel 100 includes a plurality of signal pads 110 connected to a plurality of sensor pads 110 and a plurality of signal pads 120 connected to the sensor pads 110.

Each sensor pad 110 forms a touch capacitance Ct with a touch input tool, such as a finger or a conductor, as a patterned electrode on a substrate to detect a touch input. In addition, each sensor pad 110 outputs a sensing signal according to the touch state of the touch input tool in response to the sine wave voltage Vg1. Here, the sensing signal may be a voltage change amount of the output voltage of the touch detection unit 210 due to the touch capacitance Ct or predetermined data used for touch detection, touch coordinate calculation, .

For example, the plurality of sensor pads 110 may be rectangular or rhombic, but may be other shapes, or may be polygonal shapes of uniform shape. The plurality of sensor pads 110 may be arranged in the form of a matrix of adjacent polygons.

Each sensor pad 110 may be formed of a transparent conductor. For example, each sensor pad 110 may be formed of a transparent material such as ITO (Indium Tin Oxide), ATO (Antimony Tin Oxide), CNT (Carbon Nano Tube), IZO (Indium Zinc Oxide) However, in another example, each sensor pad 110 may be formed of a metallic material.

The driving device 200 may include a touch detection unit 210, a touch information processing unit 220, a memory 230, and a control unit 240, and may be implemented as one or more integrated circuit (IC) chips.

The touch detection unit 210, the touch information processing unit 220, the memory 230, and the control unit 240 may be separated, or two or more components may be integrated.

The touch detection unit 210 may include a plurality of switches connected to each of the plurality of sensor pads 110 and the plurality of signal lines 120 and a plurality of capacitances. The touch detection unit 210 receives the drive control signal from the control unit 240 and drives circuits for touch detection (e.g., a plurality of switches, a plurality of capacitances, etc.) And outputs a voltage. The touch detection unit 210 may further include an amplifier and an analog-to-digital converter. The touch sensing unit 210 may convert, amplify, or digitize the voltage variation of each sensor pad 110 and store the same in the memory 230.

The touch information processing unit 220 processes the digital voltage stored in the memory 230 to generate necessary information such as touch state, touch area, and touch coordinates. For example, the touch information processing unit 220 may output a result of comparing the output value output from the touch detection unit 210 with the digital voltage stored in the memory 230 in response to the drive control signal of the control unit 240 .

The memory 230 stores the digital voltage based on the difference in the voltage change detected from the touch detection unit 210, predetermined data used for touch detection, area calculation, touch coordinate calculation, or data received in real time.

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

The operation of the touch screen panel and the touch detection unit shown in FIG. 3 will be described in detail with reference to FIGS. 11 and 12. FIG.

FIG. 11 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.

11, the touch detection unit 210 is connected to each sensor pad 110 through each signal line 120 and includes a first switch 211 and a second switch 212 for performing a switching operation, A capacitance C_FB, an amplification section 213, and a blocking section 214.

The first switch 211 and the second switch 212 for switching operation, the feedback capacitance C_FB, the amplification unit 213 and the blocking unit 214 are connected to the sensor pads 110 and the signal lines 120, Groups can be formed one by one.

The first switch 211 is connected between each sensor pad 110 and the first input terminal P of the amplifier 213. The first switch 211 may be a field effect transistor, for example, a gate may be supplied with a drive control signal FDRV_S and a source may be supplied with a sinusoidal signal Vg1 The drain may be connected to the first input of the amplifier 213. Of course, the source of the first switch 211 may be connected to the first input terminal of the amplifier 213, and the sine wave signal Vg1 may be applied to the drain. Here, the drive control signal FDRV_S and the sinusoidal signal Vg1 may be controlled by the control unit 240. [

The second switch 212 can control the potential between the first input terminal P and the output terminal Q of the amplifier 213. The second switch 212 may comprise at least two field effect transistors 212-1 and 212-2 as shown in Figure 4 and two field effect transistors 212-1 and 212-2 And may be connected to each other in series. In this case, the first transistor 212-1 may be connected between the first input terminal P of the amplifier 213 and the second transistor 212-2, and the second transistor 212-2 may be coupled between the first And may be connected between the transistor 212-1 and the output terminal Q of the amplification unit 213. [ Both the first transistor 212-1 and the second transistor 212-2 are controlled in synchronization with the control signal FB_S. Meanwhile, a reference voltage Vref may be applied between the first transistor 212-1 and the second transistor 212-2.

The control signal FB_S and the reference signal Vref may be controlled by the control unit 240 such that the first transistor 212-1 and the second transistor 212-1 are turned on The voltage of the first input terminal P and the output terminal Q of the amplifying unit 213 are applied to the reference voltage Vref.

On the other hand, although the second switch 212 includes two transistors in Fig. 11, the second switch 212 is not limited to this and may be formed of a single transistor.

For example, the second switch 212 may be connected in parallel with the feedback capacitance C_FB and may be controlled by the control signal FB_S. In this case, when the second switch 212 is turned on, the reference voltage Vref connected to the second input terminal of the amplifier 213 is fed back to the first input terminal P and the output terminal Q of the amplifier 213, The voltage may be the reference voltage Vref.

That is, it can be seen that the operation of the second switch 212 is the same in the case of the two transistors 212-1 and 212-2 and in the case of the single transistor. Hereinafter, the case where the second switch 212 is composed of two transistors 212-1 and 212-2 will be described.

Meanwhile, although the first switch 211 and the second switch 212 are illustrated as transistors, other elements capable of performing a switching operation can be used instead of the transistor. For example, a relay, a MOS (Metal Oxide Semiconductor) switch, a BJT (Bipolar Junction Transistor), a MOSTET (Metal Oxide Semiconductor Field Effect Transistor), an IGBT (Insulated Gate Bipolar Transistor), a TFT (Thin Film Transistor) (Operational Amplifier), and they may be formed by the homologous or interspecific combination of the two. The relay may be a 4-terminal type device in addition to the 3-terminal type device.

Hereinafter, for convenience of explanation, the first switch 211 and the second switch 212 are turned on or off according to the supplied control signals FDRV_S and FB_S, .

The reference voltage Vref is a voltage that is set in advance to compare the voltage variation? V at the output terminal Q of the amplifier 213 depending on whether or not the touch is generated. It can be adjusted to the reference voltage Vref, whereby the touch can be detected according to the voltage difference with the reference voltage Vref.

In FIG. 11, the touch capacitance Ct represents a 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.

The amplifying unit 213 has a second input terminal for connecting the first input terminal P connected to the output of the sensor pad 110 to the reference voltage Vref. The feedback capacitance C_FB may be included between the first input terminal P and the output terminal Q of the amplifier 213. The output terminal Q of the amplification unit 213 may be connected to the blocking unit 214.

The blocking unit 214 can remove a frequency component that is not included in a preset threshold range based on the frequency of the sinusoidal voltage Vg1 in the voltage level at the output terminal of the amplifier 213. [ The blocking unit 214 removes the parasitic capacitance and the noise signal that may occur in the vicinity of the touch detection. For example, the blocking unit 214 may set a certain range including the frequency of the sinusoidal signal Vg1 to a threshold range, and remove other frequencies except for the set frequency, thereby reducing the influence of noise and parasitic capacitance Eg, touch recognition errors, etc.) can be minimized. At this time, the blocking unit 214 may include any one of a low-pass filter, a high-pass filter, and a band-pass filter.

Here, the noise may include noise due to the external environment (such as LCD power supply noise), noise due to the sensor pad, circuit board, touch IC, etc., and parasitic capacitance may occur in the sensor pad 110, And may include any parasitic capacitance generated by the touch detection unit 210, the touch screen panel, and the image display device.

The driving unit 215 applies the sine wave voltage Vg1 to the sensor pad 110. [ At this time, the driving unit 215 may apply a sinusoidal voltage Vg1 to a conductive object disposed adjacent to the sensor pad 110 instead of the sensor pad 110, so that a signal may be induced to the sensor pad 110. [ The sinusoidal voltage Vg1 may be a signal that maintains a predetermined period and a single frequency, such as an AC sine signal.

Hereinafter, the operation of the circuit shown in Fig. 11 will be described with reference to Fig. At this time, the sine wave voltage Vg1 is a sine wave signal having a minimum value of 0V and a maximum value of 1.8V, and the reference voltage Vref is assumed to be 0.9V. Here, when the control signal FB_S is a low voltage (0V), the second switch 212 is turned off. When the control signal FB_S is a high voltage (1.8V), the second switch 212 is turned on and the control signal FDRV_S becomes a low voltage , The first switch 211 is turned off and the first switch 211 is turned on when the voltage is high (1.8 V).

In the meantime, for convenience of explanation, the case where a touch occurs in the sensor pad 110 (Full Touch and 1/2 Touch) will be described first before a description of the case where no touch occurs (No Touch) .

12, the minimum value of the voltage value V (Q) of the output terminal Q of the amplifier 213 when the entire area of the sensor pad 110 is touched is 0.2 V and the area of the sensor pad 110 It is assumed that the voltage value V (Q) of the output terminal Q of the amplifying unit 213 when half is touched is 0.6V. The voltage value V (Q) of the output terminal Q of the amplifier 213 is different according to the touch area where the touch input tool is touched to the sensor pad 110. Therefore, The voltage value V (Q) of the output terminal Q of the amplifier 213 can be measured or set in advance for each area.

First, a case where the touch input tool touches the entire area of the sensor pad 110 (full touch) will be described with reference to FIG. When a touch is generated, a touch capacitance Ct is formed between the sensor pad 110 and the touch input tool.

)은 초기화된다. 또한, 증폭부(213)의 출력단(Q)의 전압(V(Q))은 기준 전압(Vref)인 상태로서, 터치 여부를 검출하기 위한 기준 값이 된다. T1 구간에서의 피드백 정전용량(C_FB) 전하량(

)을 수학식으로 나타내면 다음과 같다.In the T1 interval, when the second switch 212 is turned on while the first switch 211 is turned off, the reference voltage Vref is connected through the second switch 212, The voltage V (Q) of the first input terminal P and the output terminal Q of the reference voltage generator 213 is 0.9 V which is the reference voltage Vref. At this time, both ends of the feedback capacitance are applied with the reference voltage (Vref) and there is no potential difference. Therefore, the amount of charge (C_FB) of the feedback capacitance

Is initialized. The voltage V (Q) of the output terminal Q of the amplifier 213 is a reference voltage Vref and is a reference value for detecting whether or not a touch is made. The feedback capacitance (C_FB) charge amount in the T1 section (

) Can be expressed by the following equation.

[Equation 1]

The sensor pad 110 is connected to the first input terminal P of the amplifier 213 when the first switch 211 is turned on after the second switch 212 is turned off, The voltage Vout of the output terminal Q of the amplifier 213 is gradually reduced. That is, the amount of charge in the feedback capacitance of the amplifier 213 due to the change in the amount of charge of the sinusoidal voltage Vg1 and the touch capacitance Ct applied to the sensor pad 110 is expressed by the following equation (2) (3) is summarized by the voltage variation (? V) in the feedback capacitance.

&Quot; (2) "

&Quot; (3) "

Here, Vref is the reference voltage, Ct is the touch capacitance, C_FB is the feedback capacitance, Vg1 is the instantaneous value of the sine wave voltage, and DELTA V is the voltage variation in the feedback capacitance C_FB.

According to Equation (3), DELTA V maintains the reference voltage Vref in the T1 interval, and gradually changes in accordance with the magnitude of the touch capacitance Ct and the instantaneous value Vg1 of the sinusoidal voltage in the T2 interval. Particularly, the voltage V (Q) of the output terminal Q of the amplifier 213 becomes the minimum value of 0.2 V at the instant when the instantaneous value Vg1 of the sinusoidal voltage becomes the maximum value (1.8 V).

In the T3 period, the first switch 211 is turned off. When the first switch 211 is turned off, the sensor pad 110 to which the sine wave voltage Vg1 is applied is not connected to the first input terminal P of the amplification unit 213. The first switch 211 is turned off and the sine wave voltage Vg1 is applied to the first input terminal P of the amplification unit 213 at the time when the sine wave voltage Vg1 reaches the maximum value (1.8 V) The voltage difference between the reference voltage Vref and the reference voltage Vref is maintained at 0.7 V (0.9 V - 0.2 V) in the state where the maximum value of ΔV is not satisfied.

That is, when the instantaneous value of the sinusoidal voltage Vg1 applied to the sensor pad 110 reaches a maximum value, the touch detection unit 210 detects the voltage difference of the output terminal Q of the amplification unit 213, The maximum value of the voltage variation? V of the output terminal Q of the switch 213 can be measured.

5, the voltage V (Q) of the output Q of the amplifying unit 213 is 0.2V, which is the minimum value, and the maximum value of the voltage variation becomes 0.7V. That is, the voltage V (Q) of the output terminal Q of the amplifier 213 is measured as the lowest value, so that not only a touch occurs in the sensor pad 110 but also the total area of the sensor pad 110 Touch).

Thereafter, when the second switch 212 is turned on, the voltage of the output terminal Q of the amplifier 213 may become the reference voltage Vref in the initial state.

Meanwhile, a case where the touch input tool touches a half area (1/2 touch) of the sensor pad 110 will be described.

When the first switch 211 is turned off and the second switch 212 is turned on in the period T4, the voltages of the first input terminal P and the output terminal Q of the amplifier 213 are set to 0.9 V.

The first switch 211 is turned on after the second switch 212 is turned off so that the voltage V (Q) of the output terminal Q of the amplifying unit 213 is changed according to the following equation . Here, the voltage V (Q) of the output terminal Q of the amplifier 213 is 0.6 V at the instant when the instantaneous value Vg1 of the sinusoidal voltage becomes the maximum value (1.8 V).

The first switch 211 is turned off and the sensor pad 110 to which the sine wave voltage Vg1 is applied is not connected to the first input terminal P of the amplification unit 213. [ That is, at the time when the sine wave voltage Vg1 reaches the maximum value (1.8 V), the first switch 211 is turned off and the sine wave voltage Vg1 is applied to the first input terminal P of the amplification unit 213 The voltage variation of the output terminal Q of the amplifier 213 is maintained at 0.3 V (0.9 V - 0.6 V).

The voltage V (Q) of the output terminal Q of the amplifier 213 is 0.6 V and the maximum value of the voltage variation becomes 0.3 V, as shown in Fig. That is, since the voltage V (Q) of the output terminal Q of the amplifier 213 is measured as the lowest value, it can be seen that half of the area of the sensor pad 110 is touched.

That is, when half of the area of the sensor pad 110 is touched, the voltage variation of the output terminal Q of the amplification part 213 is 0.3 V, and 0.7 V when the entire area of the sensor pad 110 is touched The voltage difference is smaller.

This is because the voltage of the output terminal Q of the amplifier 213 varies according to the value of the touch capacitance Ct according to Equation (3). As the area of the touch pad 110 touching the touch pad 110 increases, the value of DELTA V decreases as the value of the touch capacitance Ct increases, and the value of V (Q) becomes larger . That is, the voltage variation (? V) of the output terminal (Q) of the amplifier 213 differs according to the area of the sensor pad 110 where the touch input tool is touched.

Accordingly, when the voltage detection unit 210 measures the voltage variation? V of the output terminal Q of the amplification unit 213 according to the touch capacitance Ct, the touch detection unit 210 can calculate the touch area have.

Next, a case where the touch input tool is not touched to the sensor pad 110 (No touch) will be described.

When the first switch 211 is turned off and the second switch 212 is turned on, the voltage of the first input terminal P and the output terminal Q of the amplifier 213 becomes 0.9 V which is the reference voltage Vref.

When the first switch 211 is turned on after the second switch 212 is turned off, the voltage V (Q) of the output terminal Q of the amplifier 213 is calculated according to the following equation (3). The sensor pad 110 is connected to the first input terminal P of the amplifying unit 213 so that the sine wave voltage Vg1 is applied but the touch capacitance Ct is 0, The voltage V (Q) of the transistor Q is maintained at 0.9V.

Thereafter, when the sine wave voltage Vg1 reaches the maximum value (1.8 V), that is, when the first switch 211 is turned off and the sine wave voltage Vg1 is applied to the first input terminal P of the amplification unit 213 The voltage V (Q) of the output terminal Q of the amplifier 213 remains the reference voltage Vref even when the pad 110 is not connected, and there is no voltage difference.

5, the first switch 211 and the second switch 212 are turned on or off regardless of whether the touch input tool is touched to the sensor pad 110 (No Touch) The output terminal Q of the unit 213 maintains the reference voltage Vref constantly.

Therefore, the touch detection unit 210 can detect whether or not the touch is detected based on the voltage variation at the output terminal of the amplification unit 213 according to the touch capacitance. At this time, the touch detection unit 210 applies a sinusoidal voltage to the sensor pad 110, controls a plurality of switches, and outputs the voltage of the sensor pad 110 through a variation of the output voltage V (Q) of the amplification unit 213 based on the reference voltage and the sine- Touch detection and touch area can be calculated. As an example, the voltage at the output terminal (Q) of the amplification unit 213 when it is not touched (No Touch) may be a reference value of a voltage variation serving as a basis of touch detection.

13 is a waveform diagram illustrating a change in the output terminal voltage of the amplifying part according to a sinusoidal voltage when a touch is generated. 13 is a graph showing the relationship between the voltage of the output terminal of the amplifying part and the output voltage of the amplifying part according to the variation of the sinusoidal voltage Vg1 when a touch occurs (full touch and 1/2 touch) FIG. Here, the horizontal axis represents time (Time) and the vertical axis represents the output terminal voltage value (Vout) of the amplification section. The full touch is a waveform showing the change of the output terminal voltage of the amplifying part when the entire area of the sensor pad 110 is touched and the Half Touch is a waveform showing the change of the output terminal voltage of the amplifying part when the entire area of the sensor pad 110 is touched. ) Is touched to half of the area of the amplifying part.

For convenience of explanation, FIG. 13 shows a sinusoidal voltage Vg1 at the time of touch generation and an output terminal voltage of the amplification unit when a touch occurs in the waveform diagram shown in FIG. 12 in one drawing.

First, a case where the touch input tool is touched to the entire area (full touch) of the sensor pad 110 will be described.

When the second switch 212 is turned on in the state that the first switch 211 is off, the reference voltage is connected through the second switch, and the output terminal voltage Vout of the amplification unit is initially V (Q) .max .

Next, when the first switch 211 is turned on after the second switch 212 is turned off, the sensor pad 110 to which the sinusoidal voltage Vg1 is applied is connected so that the output terminal voltage Vout of the amplification part gradually decreases When the instantaneous value Vg1 of the sinusoidal voltage is the maximum value Vg1.max, the output terminal voltage Vout of the amplifier becomes the minimum value V (Q) .min.

Thereafter, when the instantaneous value Vg1 of the sine-wave voltage is the lowest value (Vg1.min) while the first switch 211 is turned off and the second switch 212 is turned on, The state V (Q) .max. 12, when the first switch 211 is turned off, the sensor pad to which the sinusoidal voltage Vg1 is applied is not connected and the voltage Vout of the output terminal is at the minimum value V (Q) min1 The output terminal voltage Vout of the amplifying part may become V (Q) .max value immediately after the second switch 212 is turned on after the second switch 212 is turned on.

Similarly, in the case where the touch input tool touches half the area (1/2 touch) of the sensor pad 110, when the whole area (full touch) of the sensor pad 110 is touched, When the instantaneous value Vg1 is the maximum value Vg1.max, the output terminal voltage Vout of the amplification section becomes the minimum value V (Q) .min2 and the instantaneous value Vg1 of the sine wave voltage becomes the minimum value Vg1.min, , The output terminal voltage Vout of the amplifying part becomes the initial value V (Q) .max again.

The minimum value V (Q) .min2 of the output terminal voltage Vout of the amplifying part has a larger value than the case where the entire area of the sensor pad 110 is touched (V (Q) .min1) . In other words, when the half area (1/2 touch) of the sensor pad 110 is touched, the voltage variation? V? Of the output terminal of the amplification part is smaller than the voltage variation? Is smaller by about 1/2 than the voltage variation? V?

Accordingly, it is understood that the output terminal voltage changes in accordance with the change of the sinusoidal voltage Vg1 when the touch is generated, but it is understood that the voltage variation? V varies depending on the touch area.

The present invention is not limited to this. However, the present invention is not limited to this, and the sine wave voltage Vg1 may be applied to the conductive object disposed adjacent to the sensor pad 110 It is possible. Accordingly, an electric field may be formed between the conductive object and the sensor pad 110, and a signal may be induced to the sensor pad 110 by the electric field. That is, the present invention is also applicable to a touch detection by a mutual method.

In the above description, the sine wave voltage Vg1 is 0 to 1.8 V and the reference voltage Vref is 0.9. However, it should be understood that the scope of the present invention is not limited to the above values.

The touch detection apparatus according to an embodiment of the present invention uses a sine wave signal (e.g., Sine type AC signal) instead of a rectangular wave type signal (e.g., a rectangular wave type signal) By eliminating frequencies other than the frequency, it is possible to minimize the influence of noise and parasitic capacitance generated when the touch screen panel is driven.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. 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.

The scope of the present invention is defined by the appended claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

100: Touch panel
110: Sensor pad
120: Signal wiring
200: Driving device
310: display panel
320: Parallax Barrier
321: Electrode

Claims (9)

A stereoscopic image display device comprising: a display panel for outputting a stereoscopic image composed of a left eye image and a right eye image; and a parallax barrier forming a light transmission area and a light shielding area when the stereoscopic image is zoomed in, Wherein the elements are formed of two or more layers,
A plurality of sensor pads forming a touch capacitance;
A driver for applying a sinusoidal voltage to each sensor pad;
An amplifier having a first input connected to an output of the sensor pad and a second input connected to a preset reference voltage;
A first switch for connecting an output of the sensor pad and a first input terminal of the amplification unit; a second switch for controlling a potential between a first input terminal and an output terminal of the amplification unit; And
And a touch detection unit for detecting whether or not a touch is generated based on a voltage variation at an output terminal of the amplification unit according to the touch capacitance,
Wherein the first switch and the second switch are alternately turned on or off.
The method according to claim 1,
Wherein the first switch is turned off when the instantaneous value of the sine wave voltage applied to each sensor pad reaches a maximum value.
3. The method of claim 2,
Wherein the touch detection unit detects a touch state by measuring a maximum value of the voltage variation at a moment when an instantaneous value of the sine wave voltage applied to the sensor pad becomes a maximum value.
The method according to claim 1,
And a blocking unit for removing a frequency component that is not included in a predetermined threshold range based on the frequency of the sine wave voltage among the voltage levels at the output terminal of the amplifying unit.
The method according to claim 1,
Wherein the driving unit applies the sine wave voltage to a conductive object disposed adjacent to the sensor pad.
The method according to claim 1,
Wherein the second switch is turned on for a predetermined time at a time point when the instantaneous value of the sine wave voltage applied to each of the sensor pads becomes a minimum value to set a reference value for detecting whether or not the touch is detected.
A stereoscopic image display device comprising: a display panel for outputting a stereoscopic image composed of a left eye image and a right eye image; and a parallax barrier forming a light transmission area and a light shielding area when the stereoscopic image is zoomed in, Wherein the elements are formed of two or more layers,
Applying a sinusoidal voltage to a sensor pad connected to a first input of the amplification unit;
Blocking the connection between the output of the sensor pad and the first input of the amplifier when the instantaneous value of the sinusoidal voltage has a maximum value; And
Detecting whether or not a touch is made based on an output terminal voltage of the amplifying part with respect to a reference voltage applied to a second input terminal of the amplifying part.
8. The method of claim 7,
Wherein the step of applying the sinusoidal voltage comprises:
And applying the sinusoidal voltage to a conductive object disposed adjacent the sensor pad.
8. The method of claim 7,
Before the step of applying the sinusoidal voltage,
The step of disconnecting the connection between the sensor pad and the first input terminal and connecting the first input terminal and the output terminal of the amplification section to each other for a predetermined time to initialize the amount of charge of the feedback capacitance connected between the first input terminal and the output terminal ≪ / RTI >

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