KR101144721B1 - Touch input device - Google Patents

Abstract

The present invention relates to a touch input device installed on an upper portion of the display device 20 and generating an input signal corresponding to a point where a touch occurs by detecting that the touch means is touched or approached on the touch panel. A touch cell 50 formed for each region in which a plurality of active regions in which touch input is made are divided on the touch panel; A plurality of signal lines 15 wired in the longitudinal or transverse direction on the touch panel and transmitting and receiving a position detection signal to the touch cell 50; A drive IC (71) for transmitting and receiving a position detection signal to the signal line (15); And a signal processor 73 generating an input signal from the position detection signal detected by the drive IC 71, wherein at least one signal line of the plurality of signal lines 15 is formed on the screen of the display device 20. It is configured to be disposed in an oblique direction with respect to the signal line 140 for display, and since the signal line 15 is not visually overlapped with the signal line of the display device 20, the effect of preventing the moiré from being viewed by the observer. To have.

Description

Touch input device

The present invention relates to a touch input device, and more particularly, to a touch input device capable of preventing moiré phenomenon caused by optical interference between a signal line of a touch panel and a signal line (or light blocking member) of a display device.

The touch input device is an input device that is added to or embedded in a display device such as a liquid crystal display (LCD), a plasma display panel (PDP), an organic light emitting diode (OLED), an active matrix organic light emitting diode (AMOLED), or the like. As an object, when an object such as a finger or a touch pen comes into contact with the screen, the device recognizes it as an input signal. Touch input devices are recently installed in mobile devices such as mobile phones, personal digital assistants (PDAs), portable multimedia players (PMPs), and the like. In addition, navigation, netbooks, laptops, digital information devices (DIDs), and touches are available. It is used across all industries, such as desktop computers using input-enabled operating systems, Internet Protocol TVs (IPTVs), high-tech fighters, tanks and armored vehicles.

Conventional touch input devices are disclosed in various types according to a method of detecting a touch input, but a resistive touch input device having a simple manufacturing process and a low manufacturing cost is most widely used. However, the resistive method has a problem in that the transmittance of the touch panel is low, a lot of missing signals, and it is difficult to accurately recognize a touch point. In particular, since the resistance method requires uniformity of sheet resistance, it is difficult to keep the sheet resistance uniform as the area of the substrate increases. As a result, it is used only in a small touch screen. On the other hand, as the demand for full touch phones has recently increased and operating systems supporting touch input have been released, the demand for touch screens has arisen in laptops and desktop computers. .

As an alternative, the demand for capacitive and optical touch input devices has recently increased. The capacitive touch input device is a method of detecting a soft touch in which a finger of the body is lightly touched by the touch panel. The capacitive touch input device can bring a high transmittance of the panel, and has a good touch sensitivity, so that there is little signal dropout. However, malfunctions are caused by noise such as static electricity, an expensive detection device is required to detect minute currents, and zero adjustment is required to detect a signal.

SUMMARY OF THE INVENTION The present invention has been proposed to solve the above problems. The present invention provides a cell structure in which a plurality of signal lines are arranged on a panel to form a touch cell by dividing an active area into a plurality of cells, and to operate each touch cell independently. It is an object of the present invention to provide a touch input device capable of preventing moiré from occurring due to optical interference between a signal line of a touch panel and a signal line (or light blocking member) of a display device.

The touch input device of the present invention for achieving the above object, is installed on the upper portion of the display device 20, detects that the touch means is contacted or approached on the touch panel to input an input signal corresponding to the point where the touch occurs A touch input device, comprising: a touch cell (50) formed for each area in which a plurality of active areas for touch input are divided on the touch panel; A plurality of signal lines 15 wired in the longitudinal or transverse direction on the touch panel and transmitting and receiving a position detection signal to the touch cell 50; A drive IC (71) for transmitting and receiving a position detection signal to the signal line (15); And a signal processor 73 generating an input signal from the position detection signal detected by the drive IC 71, wherein at least one signal line of the plurality of signal lines 15 is formed on the screen of the display device 20. It is disposed in an oblique direction with respect to the signal line 140 for display.

According to one embodiment, at least one or more signal lines of the plurality of signal lines 15 are arranged in a zigzag form.

According to the touch input device of the present invention, the signal line of the touch panel is disposed in an oblique direction with respect to the signal line of the display device, thereby blocking a light blocking member (eg, a black matrix) formed between the signal line or the pixel electrode for displaying the screen of the display device. The signal lines arranged vertically and horizontally on the touch panel are not superimposed on the observer, and the moiré interference does not occur, thereby preventing the display quality from being reduced by the moiré.

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

First of all, the present invention relates to a touch input device installed in addition to an upper surface of a display device such as LCD, PDP, OLED, AMOLED, etc., wherein the touch cells formed by dividing an active area are arranged in a matrix form. It is about. The present invention arranges a plurality of signal lines in a longitudinal direction or a transverse direction on a touch panel in order to transmit and receive a position detection signal to each touch cell. As such, in the case where a plurality of signal lines are disposed on the touch panel, the light blocking member (eg, formed between the signal lines (eg, a gate line and a source line of the LCD, etc.) or pixel electrode for displaying the screen of the display device, for example, Black matrix) and light interference to generate moiré, and the present invention is characterized in eliminating such moiré phenomena.

In the following description of the various embodiments, each embodiment will first be described with respect to the configuration of the touch panel and the touch cell, and then an embodiment for removing the moiré phenomenon will be described. Although the embodiments mentioned are some embodiments, the technical idea of the present invention is not only to the embodiments mentioned but also to a touch input having a structure in which a plurality of signal lines are arranged vertically and horizontally on a touch panel to transmit and receive a position detection signal to a touch cell. Applicability to all of the devices will be apparent to those of ordinary skill in the art.

In the drawings, thicknesses or regions are enlarged in order to clearly express various layers and regions. And when a part of a layer, an area | region, a board | substrate, etc. is said to be "on" or "top" another part, this includes not only the case where another part is "right on" but also another part in the middle. On the contrary, when a part is "just above" another part, there is no other part in the middle.

Although both the signal lines provided on the touch panel and the signal lines of the display device are referred to as "signal lines" in the present specification, both of them are clearly different from each other, and the signal lines provided on the touch panel are used for detecting touch input. It is obvious that the signal line is the signal line and the signal line of the display device is a signal line for screen display, and its operation is also clearly different.

The same reference numerals are used for similar parts throughout the specification. In addition, in the embodiments described below, the switching element may be replaced with "TFT", and the same reference numerals will be used for the switching element and the TFT.

1 is an exploded perspective view showing the configuration of a pressure type touch input device according to the present invention. As illustrated, a touch panel is installed on the upper surface of the display device 20. Herein, the term "display device" means a device including a display panel (for example, a liquid crystal panel) and a backlight (as in a non-light emitting panel such as a liquid crystal panel) if necessary.

In the pressure type touch input device as shown in FIG. 1, the touch panel includes a first substrate 40 and a second substrate 60 disposed to face each other. The drive IC 71 is mounted on the edge portion of the first substrate 40 or the second substrate 60. Preferably, the drive IC is mounted on the upper edge portion of the first substrate 40 located below. The drive IC 71 is an IC for transmitting and receiving a position detection signal, and is mounted in the form of a chip on film (COF) or a chip on glass (COG) at an edge portion of the substrate. In the illustrated example, an example in which the drive IC 71 is configured as a single IC is illustrated. However, the drive IC 71 may be separately configured.

The first substrate 40 and the second substrate 60 are both formed of transparent glass, plastic or film. Of course, it may be formed of another material having a light transmittance. Preferably, a glass substrate is used as the first substrate 40, and the touch cell 50 and the signal lines 15 are wired on the glass substrate. A film substrate is used as the second substrate 60, and the film substrate is bent by contact with a touch means such as a finger or a stylus pen to contact the first substrate 40.

2 illustrates a circuit configuration of a pressure touch cell. In FIG. 2, parts indicated by solid lines are components installed on the upper surface of the first substrate 40, and parts indicated by dotted lines are components installed on the lower surface of the second substrate 60. As illustrated, the touch cell 50 is formed on the first substrate 40 for each area in which a plurality of active areas for actual touch input are divided. Substantially, the touch cell 50 may be disposed at a very high resolution. However, in the illustrated embodiments, the touch cell 50 is illustrated with the assumption that the touch cell 50 is disposed at a resolution of 3 * 3 to help understanding of the present invention.

Each unit touch cell 50 includes a conductive pad 45. As shown, the conductive pads 45 are formed to partition an area from the neighboring touch cell 50. A conductive layer 62 is formed on the bottom surface of the second substrate 60 as shown by the dotted lines. The conductive pad 45 and the conductive layer 62 may be formed on a substrate by using a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), antimony tin oxide (ATO), or carbon nanotube (Carbon Nano Tube). It is formed by applying. The conductive layer 62 may be formed over the entire area of the lower surface of the second substrate 60, but is preferably partitioned in a row or column direction, or divided into unit touch cells 50 as shown in FIG. 2. Is formed. As shown in FIG. 2, when the conductive layer 62 is divided into unit touch cells 50, a signal when the conductive layer 62 and the conductive pad 45 are energized may be electrically isolated from each touch cell 50. Can be. That is, by separating only the signals transmitted to the respective touch cells 50, the signal can be prevented from flowing back to the other touch cells 50 and the multi-touch input can be recognized. An example of recognizing a multi-touch input will be described later.

As illustrated, a first signal line 42 and a second signal line 44 are connected to each of the conductive layer 62 and the conductive pad 45. The first signal line 42 and the second signal line 44 are signal lines for transmitting and receiving the position detection signal and are controlled by the drive IC 71. In the illustrated example, the first signal line 42 is wired in the lateral direction and the second signal line 44 is wired in the longitudinal direction, but the wiring direction of each signal line is not limited to the illustrated example and must also cross each other. It is not. For example, the first signal line 42 and the second signal line 44 may be wired in an oblique shape or a zigzag shape, or may be wired in parallel with each other.

The signal lines are, for example, aluminum-based metals such as aluminum and aluminum alloys, silver-based metals such as silver and silver alloys, copper-based metals such as copper and copper alloys, and molybdenum-based metals such as molybdenum and molybdenum alloys, chromium and titanium , Tantalum or the like is preferable. The first signal line 42 and the second signal line 44, and other signal lines not mentioned in the present embodiment but mentioned in the following embodiments, are two films having different physical properties, that is, a lower film (not shown) and the same. It may include an upper layer (not shown). The upper layer is made of a low resistivity metal such as aluminum (Al) or an aluminum alloy to reduce signal delay or voltage drop. In contrast, the lower layer is made of a material having excellent contact properties with ITO or IZO, such as molybdenum (Mo), molybdenum alloy, and chromium (Cr).

The signal lines are preferably formed of a transparent conductor so as to avoid being viewed by the observer. When the signal lines are formed of a transparent conductor, a metal line signal line may be used in part for the purpose of reducing the resistance of the signal line. In addition, a metal line signal line may be used at the intersection of the signal lines to reduce mutual capacitance generated between the signal lines. The signal lines formed in the heterogeneous layers are connected to other components by contact holes 59.

3 is a block diagram illustrating a system configuration of a touch input detection device of the present invention, and FIG. 4 is a waveform diagram showing an example of recognizing a touch input in the embodiment as shown in FIG. 2. Referring to FIG. 3, the touch position detector 70 applies signals for position detection to each touch cell 50 and obtains a coordinate value from the touch cell 50 to generate an input signal. ), A signal processor 73, a timing controller 74, and a memory means 75. The signal detected by the touch position detector 70 is transmitted to the CPU 80. The CPU may be a CPU of the display device 20, a main CPU of a computer device, or a CPU of the touch input device itself. Although not shown, the system configuration further includes a power supply unit for generating a high or low voltage of signals for detecting a touch input.

The timing controller 74 generates a time division signal of several tens of ms or less, the signal processing unit 73 applies a time-divided position detection signal to each of the first signal lines 42 through the drive IC 71, and the second signal line ( 44) to obtain the coordinate value of the point where the touch input occurs by detecting the signal. Preferably, the signal processor 73 maintains the other first signal lines 42 in a high impedance or floating state at the moment of applying a position detection signal to any one first signal line 42. do. A resistor connected to the ground may be installed at the end of the second signal line 44 to set the input signal to the ground level when no touch input occurs.

The memory means 75 is a means for temporarily storing the obtained coordinate values. The signal processor 73 may miss some signals when it is in a "Busy" state in the course of processing a large number of signals. Therefore, the signal processor 73 temporarily stores the obtained signals in the memory means 75, scans the entire signals once, and reads the memory means 75 to determine whether there are any missing signals. If there is a missing signal, the signal is generated as a normal input signal, and the memory means 75 is erased before the next scanning.

Referring to the waveform diagram of Fig. 4, the period of the pulse of the position detection signal is "T". If a touch input is generated in the touch cell 50 at the lower right in FIG. 2, the signal S3 may be obtained through the second right signal line 44 at the rightmost time between t3 and t4 times. In this case, the signal processor 73 generates an input signal corresponding to the coordinate values "D3 and S3" of the touch cell 50.

5 shows another embodiment of a pressure touch cell. Referring to FIG. 5, in contrast to the embodiment of FIG. 2, the conductive pads 45 constituting the touch cell 50 are formed in pairs, and the signal lines are all disposed on the first substrate 40. As shown, the touch cell 50 is composed of a pair of first conductive pads 46 and second conductive pads 48 spaced apart from each other by a predetermined distance. In each touch cell 50, the first conductive pad 46 is connected to the first signal line 42, and the second conductive pad 48 is connected to the second signal line 44.

In this embodiment, a separate signal does not need to be applied to the conductive layer 62 formed on the lower surface of the second substrate 60. The conductive layer 62 may only serve as a current collector for energizing the pair of first conductive pads 46 and the second conductive pads 48. Therefore, the configuration of the second substrate 60 is greatly simplified. In addition, when the conductive layer 62 is partitioned and formed for each touch cell 50, the signal from each touch cell 50 can be electrically blocked, and the transmittance of the panel can be improved.

6 shows another circuit configuration of the pressure type touch cell, and shows an example of switching a signal in each touch cell 50 using a switching element.

Referring to FIG. 6, the switching element 35 is connected between the second conductive pad 48 and the second signal line 44. The switching element 35 is to prevent the signal from flowing back and may be configured by using the breakdown voltage of the diode. Preferably, the switching element 35 is a three-terminal element that is easier to control than the two-terminal element.

The three-terminal switching element 35 is a device for controlling the conduction of the input and output terminals according to a signal applied to the control terminal, and includes a relay, a metal oxide semiconductor (MOS) switch, a bipolar junction transistor (BJT), and a FET ( Field Effect Transistors (MOS), Metal Oxide Semiconductor Field Effect Transistors (MOSFETs), Insulated Gate Bipolar Transistors (IGBTs), and Thin Film Transistors (TFTs). Relay is a device that outputs voltage or current applied to input terminal without loss when current is applied to control terminal, and BJT is applied to base that is higher than threshold voltage of base. When current flows to the base terminal at, a certain amount of amplified current flows from the collector to the emitter. In addition, TFT is a switching element used in the pixel portion of a display device such as LCD or AMOLED. It is composed of a gate terminal as a control terminal, a drain terminal as an input terminal, and a source terminal as an output terminal. When a voltage that is more than a threshold voltage is applied to the gate terminal as a voltage applied to the gate terminal, the current flows from the input terminal to the output terminal while conducting. In the following description, a TFT having already been verified for reliability in LCD or AMOLED is used as the switching element 35, and the same reference numeral as that of the switching element 35 is given to the TFT.

FIG. 7 is a plan view illustrating a configuration of a unit touch cell in the embodiment of FIG. 6, and FIG. 8 is a cross-sectional view illustrating a cross section taken along line I-II of FIG. 7. Referring to FIG. 7, the first signal line 42 and the gate signal line 38 are disposed in the horizontal direction on the upper surface of the first substrate 40, and the second signal line 44 is disposed in the longitudinal direction. As illustrated, when the first signal line 42 and the gate signal line 38 are arranged side by side, the first signal line 42 and the gate signal line 38 can be wired using the same layer.

The first conductive pad 46 is connected to the first signal line 42 via the contact hole 59. The TFT 35 provided between the second conductive pad 48 and the second signal line 44 has the following circuit configuration. The drain electrode 51 of the TFT 35 is connected to the second conductive pad 48 via the contact hole 59. The source electrode 52 of the TFT 35 is connected to the second signal line 44, and the gate electrode 53 is connected to the gate signal line 38.

Referring to the cross-sectional layer structure of FIG. 8, a gate insulating film 66 made of silicon nitride (SiNx) or the like is formed on the gate electrode 53 of the TFT 35, and overlaps with the gate electrode 53 on the gate insulating film 66. An active layer 69 is formed between the drain electrode 51 and the source electrode 52 to form a channel. The active layer 69 is formed of hydrogenated amorphous silicon, poly crystalline silicon, or the like. An ohmic contact layer 68 for ohmic contact between the drain electrode 51 and the source electrode 52 is formed on the active layer 69. The ohmic contact layer 68 is made of a material such as silicide or n + hydrogenated amorphous silicon doped with a high concentration of n-type impurities. The passivation layer 67 is formed on the drain electrode 51 and the source electrode 52, and the first conductive pad 46 and the first conductive pad 46 formed of a transparent conductive material such as ITO, IZO, ATO, CNT, etc. are formed on the upper surface of the passivation layer 67. 2 conductive pads 48 are located.

As described above, a contact hole 59 is used to connect signal lines located on different layers and to connect a pair of conductive pads 46 and 48 with other components, and the contact hole 59 is used. Can be made into various shapes such as polygons or circles.

In addition, although not shown, a light shielding layer for blocking light may be provided on the TFT 35. The light shielding layer may be formed of a source metal used for the manufacture of the drain electrode 51 or the source electrode 52 of the TFT 35, a gate metal used for the manufacture of the gate electrode 53, an impermeable insulating film, or the like. Can be. The impermeable insulating film is formed of an oxide film, a nitride film, an insulating polysilicon film, or the like. The light shielding layer prevents the TFT 35 from malfunctioning in response to light.

In order to maintain the two substrates 40 and 60 at predetermined intervals, a spacer 25 such as a ball spacer 25a or a pattern spacer 25b is disposed between the two substrates 40 and 60 as shown in the figure. ) Is installed.

In the embodiment of FIG. 6, the signal processor 73 sequentially applies the gate signal Gn to each gate signal line 38 to selectively activate only the touch cells 50 for detecting touch input, and the other touch cells 50. ) Can be disabled. For example, when G1 applies an on signal, G2 and G3 apply an off signal. In a state in which the touch cells 50 of the first row are activated by G1, when a touch input is generated in the upper left touch cell 50, the S1 signal is obtained. At this time, since the second signal lines 44 are arranged in the column direction, the signal does not flow back to the other touch cells 50. Therefore, the multi-touch input can be detected.

Meanwhile, although the connection relationship of the TFTs 35 is mentioned in the embodiment with reference to FIG. 6, the TFTs 35 may be connected in other ways. For example, a gate terminal may be connected to the second conductive pad 48. As another example, the TFT 35 may be provided between the first signal line 42 and the first conductive pad 46.

9 shows another circuit configuration of the touch cell 50. Referring to FIG. 9, a first switching element 35a is disposed between the first signal line 42 and the first conductive pad 46, and is provided between the second signal line 44 and the second conductive pad 48. The second switching element 35b is provided. Both switching elements are also preferably TFTs. The circuit configuration of the second TFT 35b is the same as that in FIG. 6, and the circuit configuration of the first TFT 35a is a structure in which a gate terminal is connected to the gate signal line 38 as shown.

According to the configuration of the touch cell 50, the pair of conductive pads 46 and 48 constituting the touch cell 50 may be completely isolated from the signal line. For example, when the gate signal is blocked, even if the pair of conductive pads 46 and 48 are in contact with the conductive layer 62 in the touch cell 50, the position detection signal is not provided through the first signal line 42. The position detection signal is not obtained through the second signal line 44. Accordingly, even if the conductive layer 62 is not formed on the bottom surface of the second substrate 60, the position detection signal can be accurately recognized in synchronization with the gate signal, and the multi-touch can be more stably recognized.

As described above, switching signals in each touch cell using TFTs is similar to a method in which pixels are formed using TFTs for screen display in a similar LCD (or active matrix LCD) or AMOLED. That is, the touch cells 50 mentioned in the present invention detect the touch input by the active matrix method. The technical advantages thereof are good mass productivity, reliability, and the like of the touch panel, and it is possible to prevent backflow of signals to prevent misrecognition of touch inputs and to recognize multi-touch inputs in which a plurality of points are in contact at the same time.

Here, in the structure in which a plurality of touch cells 50 are formed on the touch panel and the signal lines 15 for transmitting and receiving the position detection signal are connected to each touch cell 50 as shown in the present invention, as shown in FIG. As described above, the signal line 15 of the touch panel may cause light interference with the signal line 140 or the light blocking member 340 of the display device 20 to cause a moire phenomenon. Referring to Figure 10 will be briefly described the principle that the moiré phenomenon occurs.

When the observer observes the touch panel as shown in FIG. 10, the touch panel and the display device 20 are visually recognized in the observer's field of view. In this case, the light emitted from the rear of the display device 20 is provided on the light blocking member 340 (eg, a black matrix formed between the pixels) of the display device 20 and the signal line provided on the first substrate 40 of the touch panel. It may be partially blocked at (15). At this time, in some regions, the light is transmitted as it is, but in another region, the light is blocked by any one of the light blocking member 34 of the display device 20 or the signal line 15 of the touch panel. 34 and the signal line 15 overlap to block light. This is admitted to the observer as a repetition of the contrast pattern.

The moiré interference phenomenon is an interference that occurs when overlapping spatial patterns with periodicity are easily recognized by an observer. The moiré pattern perceived by the observer is called a moiré moire or moiré phenomenon. The moire fringes act as a cause of degrading the display quality.

The moiré pattern varies in size and shape depending on the size of the pixel, the position of the observer, the distance between the touch panel and the display device, and the like. For example, in the display device, although the signal line formed on the TFT substrate and the BM (Black Matrix) formed on the color filter substrate are located on the same vertical line, the TFT substrate and the color filter substrate are spaced apart at intervals of several micrometers. For the observer, the signal line and BM always overlap. That is, the moiré as above does not occur.

However, in the case where the touch panel is additionally installed on the upper surface of the display device 20, the display device 20 and the touch panel are spaced apart at intervals of several hundred μm to several mm. Accordingly, as shown in FIG. 10, when the light blocking member 340 of the display device 20 and the signal line 15 of the touch panel are positioned on the same vertical line, in some areas, the light blocking member 340 or the signal line 15 may be disposed. ) Is recognized only, and the moire pattern appears because the light blocking member 340 and the signal line 15 overlap each other.

11 and 12 show an embodiment of removing the moiré phenomenon according to the present invention. In the touch input device of the present invention, as illustrated in FIG. 11, a diffusion sheet 90 is installed between the touch panel and the display device 20. The diffusion sheet 90 is a sheet for diffusing (or dispersing) light and dispersing a path of light emitted from the display device 20 to suppress moiré interference. As one example, the diffusion sheet 90 is composed of a diffusion film and a Brightness Enhancing Film (BEF), it may be formed by overlapping two films in two or more layers.

Referring to the cross-sectional view of FIG. 12, the stacked structure of the display device 20 and the touch panel will be described in more detail. The illustrated display device 20 is a liquid crystal display device. As shown, the display device 20 has a structure in which a backlight, a lower polarizer 400, a lower substrate 100, a liquid crystal layer 200, an upper substrate 300, and an upper polarizer 410 are sequentially stacked. Has

The upper and lower polarizers 400 and 410 determine the transmission and blocking of the backlight light when the TFT of each pixel is turned on / off to change the arrangement of the liquid crystal, thereby enabling various colors to be realized through the color filter.

The lower substrate 100 is a TFT substrate or an array substrate. The lower substrate 100 is a thin film element 120, a pixel electrode 130, and a signal line 140 for supplying an image signal to the pixel electrode 130 on an upper surface of the insulating substrate 110. It has an installed configuration. The thin film device 120 includes a TFT for switching the pixel electrode 130 and a capacitor connected to the TFT. The signal line 140 is a gate line for applying an on / off control signal to the gate of the TFT and a source line for supplying an image signal as in a conventional LCD.

The upper substrate 300 is a color filter substrate, and the light blocking member 340 and the color filter 330 are formed on the lower surface of the insulating substrate 350, and the overcoat 320 and the common electrode 310 are formed thereon. Has The common electrode 310 is an electrode that provides a Vcom voltage for determining dynamic characteristics of the liquid crystal. The color filter 330 provides R, G, and B colors corresponding to each pixel, and an overcoat 32 is used to protect the color filter 330. The light blocking member 340 is a member that blocks the boundary between each pixel from being recognized, and is a black matrix formed by applying black ink or the like.

As illustrated, the liquid crystal is sealed between the lower substrate 100 and the upper substrate 300 to form the liquid crystal layer 200.

When the touch panel of the present invention is installed on the upper surface of the display device 20 as described above, the diffusion sheet 90 is interposed between the display device 20 and the touch panel as shown. The diffusion sheet 90 diffuses light from the upper portion of the light blocking member 340 so that the light blocking member 340 and the signal line 15 of the touch panel do not cause mutual interference.

Furthermore, as shown in FIG. 12, a diffusion sheet 95 may be further installed on the touch panel. In such a structure, the diffusion sheet 90 between the display device 20 and the touch panel diffuses the light on the light blocking member 340, and the diffusion sheet 95 on the touch panel is the signal line 15 of the touch panel. By spreading light in the upper part, moiré can be suppressed more reliably.

The embodiment of FIG. 12 also shows the wiring structure of the signal line for removing moiré, and FIG. 13 shows an example of avoiding moiré by wiring the signal line 15 of the touch panel. Although the width of the signal line 15 is exaggerated in FIG. 13 to facilitate understanding of the present invention, the actual signal line 15 has a width of several micrometers to several tens of micrometers. In addition, although the signal line 15 of the touch panel is illustrated to be wired at the same pitch as the light blocking member 340 of the display device 20, the light blocking member 340 of the display device 20 is actually pitched in pixel units. While formed, the signal lines 15 of the touch panel may be wired with a wider pitch.

As illustrated, the signal line 15 of the touch panel is disposed on a vertical line different from the light blocking member 340 of the display device 20. As such, when the signal line 15 of the touch panel is disposed to be perpendicular to the light blocking member 340, as illustrated in FIG. 13, the touch panel overlaps the signal line 15 and the light blocking member 340 and is viewed by an observer. Can be avoided. This is because the signal line 15 and the light blocking member 340 are formed to have a very narrow width.

Therefore, in addition to providing the diffusion sheet 90, at least some of the signal lines 15 of the touch panel are arranged on a vertical line different from the light blocking member 340 or the signal line 140 of the display device 20. Can be suppressed more reliably.

In the above, the example of avoiding moiré in the touch input device configuring the touch cell 50 by the pressure type has been described. Next, a touch input device constituting the touch cell 50 in a capacitive manner will be described, and an example of avoiding moiré in the capacitive touch input device will be described.

The capacitive touch input device may be a contactless part of a body such as a finger, an iron writing instrument, an electronic pen for generating a predetermined electrical signal, or other similar touch means in a non-contact manner (the substrate may be in contact with the substrate). ), The charge accumulated in the virtual capacitor formed between the touch means and the touch pad is detected in various ways to obtain a touch signal.

In one embodiment, the switching element is turned on / off by a virtual capacitor formed between the touch means and the touch pad to obtain a touch signal. In addition, the on / off control signal of the switching element may be separately applied, and the touch signal may be obtained by detecting the charge accumulated in the virtual capacitor formed between the touch means and the conductive pad. In addition, when the electronic pen emitting a predetermined electrical signal approaches the conductive pad, the touch signal may be acquired by detecting that the virtual capacitor is charged or discharged. Hereinafter, a method of turning on / off the switching element by using the potential of the touch pad will be described. In the embodiments described below, the switching element is preferably a TFT, and the same reference numerals are used.

As shown in FIG. 14, the capacitive touch input device may configure a touch panel using a single substrate. Referring to FIG. 14, the display device 20 is the same as the display device described above, and the touch panel of the single substrate 30 is provided on the upper surface of the display device 20. As shown, the drive IC 71 is mounted on the edge portion of the substrate 30, and the system configuration for detecting the drive IC 71 and the touch input will be described with reference to the block diagram of FIG.

First, the principle of detecting a non-contact touch input in a capacitive manner will be briefly described with reference to FIG. 15. Referring to FIG. 15, when the finger 29 (or similar conductive touch means) approaches the touch pad 55, the touch pad 55 and the finger 29 are spaced at an interval of “d”, and “A”. Suppose you have an opposing area. Then, the capacitance “C” is formed between the finger 29 and the touch pad 55 as shown in the right equivalent circuit and the equation of FIG. 15. When a charge having a magnitude of charge amount "Q" is accumulated by supplying a signal of voltage or current to touch pad 55 having capacitance "C", a voltage relation equation of V = Q / C is formed. At this time, the body is virtually grounded with respect to the earth.

If the finger 29 applies a signal to the touch pad 55 in a state where the finger 29 faces the touch pad 55 at an interval of d, the charge C is formed between the touch pad 55 and the finger 29. Is charged. At this time, since the gate terminal of the TFT 35 is connected to the touch pad 55 as shown in the drawing, during the time when the charge is charged on the touch pad 55 and the time when the signal accumulated in the capacitance C is discharged. TFT 35 is turned on. The magnitude of the discharged signal gradually decreases with time, and when discharged to some extent, the TFT 35 is turned off. The embodiment of the capacitive touch input device described below detects the non-contact touch input by using the variation of the gate terminal potential of the TFT 35 by the capacitance between the touch means and the touch pad 55 as described above.

16 is a circuit diagram illustrating one embodiment of a capacitive touch cell. Referring to this, a plurality of touch cells 50 are arranged in a matrix form on the top or bottom surface of the substrate 30. In addition, a plurality of first signal lines 42, second signal lines 44, and auxiliary signal lines 37 are disposed on the substrate 30. The first signal line 42 and the second signal line 44 are lines for transmitting and receiving the position detection signal, and the auxiliary signal line 37 is a line for applying the observation auxiliary signal.

As shown in FIG. 16, the touch pads 55 are partitioned in the unit touch cell 50, and the gate terminal of the TFT 35 is connected to the touch pad 55. In addition, in order to apply a charging signal to the touch pad 55, the touch pad 55 is also connected to the first signal line 42. A drain terminal, which is an input terminal of the TFT 35, is connected to the auxiliary preferred line 37, and a source terminal, which is an output terminal, is connected to the second signal line 44.

The drive IC 71 applies the time-detected position detection signal to the first signal line 42. When the finger 29 approaches the touch cell 50 when the position detection signal is applied, the virtual capacitor is charged while electric charge is accumulated between the finger 50 and the touch pad 55. Thereafter, when the application of the position detection signal to the touch cell 50 is completed, the touch pad 55 starts discharging. At this time, the discharge current is gently lowered compared to when the touch input does not occur. Therefore, the turn-off of the TFT 35 is delayed. That is, the signal processor 73 detects the delayed signal from the second signal line 44 and generates an input signal.

17 is a circuit diagram illustrating another embodiment of the capacitive touch cell. Referring to FIG. 17, a first signal line 42, a second signal line 44, a gate signal line 38, and an auxiliary signal line 37 are disposed on one surface of the substrate 30. Each touch cell 50 includes a touch pad 55, a first TFT 35a, and a second TFT 35b. The gate terminal of the first TFT 35a is connected to the gate signal line 38, the input terminal is connected to the first signal line 42, and the output terminal is connected to the touch pad 55. The gate terminal of the second TFT 35b is connected to the touch pad 55, the input terminal is connected to the auxiliary signal line 37, and the output terminal is connected to the second signal line 44.

In the present exemplary embodiment, the touch input detector 70 sequentially applies scan pulses to the gate signal lines 38 to sequentially conduct the first TFTs 35a. Alternatively, the gate signal Gn (n = 1, 2, 3) may be simultaneously turned on to induce charging with the body, and then the observation auxiliary signal may be applied to the auxiliary signal line 37 to detect a location where a touch input occurs. .

18 is a waveform diagram illustrating an example of obtaining a touch signal in the embodiment of FIG. 17. Referring to this, the touch input detector 70 sequentially provides scan pulses to the gate signal lines 38. The gate signal Gn provided by the touch input detector 70 has a voltage level large enough to allow the gate of the first TFT 35a to enter the active region. For example, the gate signal Gn is preferably set to be 3V or more larger than the position detection signal Dn transmitted through the first signal line 42. In a preferred embodiment, the Hi voltage level of Dn is 13V and the Hi voltage level of Gn is 18V. In addition, in order to stably turn off the first TFT 35a, the gate OFF voltage is set to -5 to -7V.

The gate signal Gn has sufficient observation time between each signal. This is for the virtual capacitor formed by the finger 29 and the touch pad 55 of the body to have a sufficient discharge time. As shown, a sufficient period of observation time 1 is given between G1 and G2. The position detection signal Dn applied through the first signal line 42 is provided to necessarily maintain Hi when any one of Gn is Hi, and preferably also has a slight rest when Gn has a rest period.

The touch input detector 70 provides an observation voltage through the auxiliary signal line 37. The auxiliary signal Auxn provides an observation voltage lower than 3V compared to 13V, which is a voltage charged to the touch pad 55 by Dn at the Hi level. For example, the observed voltage of Auxn is about 5V.

Referring to FIG. 18, a waveform obtained through the second signal line 44 and a process of obtaining a touch signal through the same will be described below.

If, as in the case where the gate signals G1 and G2 are applied, if the gate signal is applied and the finger 29 is not accessible even after the observation time has passed, the signal Sn obtained through the second signal line 44 is shown. Has a waveform as shown. This is because the capacitance is not formed in the touch pad 55 because the body is not accessible. The reason why the waveform of Sn has a curve in a section rising to the Hi level and a section falling to the Low level is because the wiring resistance and the parasitic capacitance of the second signal line 44 exist. As shown, the time from the observation time of Gn to the time when the signal Sn falls to the low level completely is "T1". However, the time delay generated in the output signal Sn is ignored in comparison with the input signal Dn in the waveform diagram.

If the finger 29 approaches the lower right touch cell 50 of FIG. 17 at some point, a capacitance is formed between the touch pad 55 and the finger 29 of the touch cell 50. Will be. As shown in the waveform diagram of FIG. 18, if a touch occurs in a section where G3 is at a Hi level, there may be a change in the charging voltage at the initial stage of charging as the waveform of S3 is distorted at the point of touch generation. However, as soon as charging is complete, S3 rises to the Hi level.

However, when the mode is changed to the observation time of the G3 signal, that is, when the G3 is turned off, the voltage of the second TFT 35b is gradually decreased while the voltage charged in the virtual capacitor is discharged, and the second TFT 35b is gradually decreased. The output waveform of the current flowing through) shows inherent output characteristics as shown in the waveform of S3. At this time, suppose that the time taken for the waveform of Sn to fall below 50% is "T2".

Referring to the waveform diagram of FIG. 18, it can be seen that T1 and T2 show a significant time difference. The touch input detection unit 70 may obtain a touch signal by reading the time taken for the waveform of the signal Sn to fall or the magnitude of the voltage or current dropped at a certain point in time after the Gn is turned off. In this example, since the touch signal S3 is acquired at the observation time after the gate signal G3 is OFF, the obtained touch signal is a coordinate value corresponding to "D3, S3".

16 and 17 illustrate embodiments in which each touch cell 50 may be electrically disconnected from the other touch cells 50 by the TFT. Accordingly, multi-touch inputs may be recognized. For example, the touch position detector 70 sequentially scans Gn in the row direction, and the second signal line 44 receives a detection signal from each touch cell 50 in the column direction. One scanning time of Gn is approximately tens of microseconds to several tens of ms. Therefore, even when several tens of touch cells 50 are touched at the same time, since Gn is scanned in the row direction and Sn is obtained in the column direction, all touch points can be recognized within tens of ms.

The method of avoiding moiré in the capacitive touch input device described above is substantially the same as the method of avoiding moiré in the pressure type touch input device. 19 shows an example in which the diffusion sheet 90 is installed in the capacitive touch input device. As shown, a diffusion sheet 90 is disposed between the display device 20 and the substrate 30 of the touch panel. Although not shown, in the capacitive touch input device, the diffusion sheet 90 may be further installed on the upper surface of the substrate 30 of the touch panel. In addition, as shown in FIG. 13, at least some of the signal lines 15 of the touch panel are positioned on a vertical line different from the light blocking member 340 of the display device 20.

Although the above described moiré avoidance structure is applied to pressure and capacitive touch input devices, the technical idea of the present invention may be applied to other touch input devices that are not mentioned as long as the signal lines are wired on the touch panel. In addition, the pressure and capacitive touch input devices may configure the touch cell 50 in a structure different from the above-described embodiment.

FIG. 20 illustrates a complex touch input device in which different touch cells 81 and 82 are combined. The unit touch cell 50 has a configuration in which four pressure-type touch cells 81 and one capacitive touch cell 82 are formed in combination. Each pressure touch cell 81 is composed of a pair of conductive pads 46 and 48 as in the embodiment shown in FIG. 5, and each of the conductive pads 46 and 48 has a pressure-type first signal line 83. And a pressure-type second signal line 84 are connected. Each capacitive touch cell 82 is composed of a touch pad 55 and a TFT 35 as in the embodiment shown in FIG. 16, and the touch pad 55 is connected to the gate terminal of the TFT 35 and is capacitive. The charging signal is applied from the first signal line 86. The input terminal of the TFT 35 is connected to the capacitive second signal line 87 for applying an auxiliary signal for observation, and the output terminal is connected to the capacitive third signal line 88 for transmitting the discharge signal of the touch pad 55. Connected. Since each operation has been described in the above embodiments, a description thereof will be omitted.

Each pressure touch cell 81 and capacitive touch cell 82 may be replaced with the other embodiments described above, and may have a circuit configuration not mentioned. In addition, the configuration of the touch cell 50 may be configured such that one pressure type touch cell 81 and one capacitive touch cell 82 are formed in an overlapping area, and the pressure type touch cell 81 and the capacitance. The touch cell 82 may be formed in different regions. In addition, optical or other types of touch cells may be combined.

Such a composite touch input device can detect various touch inputs of various touch means, input such as clicking an icon with a touch on a GUI (Graphic User Interface), and handwriting such as writing a character or drawing an image with a touch. It is very effective in classifying and detecting inputs.

Here, the same thing as the composite touch input device of FIG. 20 is that the signal lines 15 are wired on the touch panel. Therefore, even in the complex touch input device of FIG. 20, moiré due to optical interference between the signal line 15 of the touch panel and the light blocking member 340 of the display device 20 can be prevented in the same manner as in FIGS. 10 to 13. have.

21 shows another example for avoiding moiré. Here, the embodiment of FIG. 21 has a capacitive touch cell 50 having a structure different from that of the capacitive touch input device mentioned above.

Referring to FIG. 21, each touch cell 50 includes a touch pad 55 and a TFT 35. A plurality of first signal lines 42 and second signal lines 44 are wired to the touch panel. The TFT 35 of each touch cell 50 has a gate terminal connected to the first signal line 42, and an input / output terminal connected to the second signal line 44 and the touch pad 55, respectively. The first signal line 42 applies an on / off control signal to the gate terminal of the TFT 35. The second signal line 44 transmits and receives a position detection signal to each touch cell 50.

The operation in this structure is as follows. First, the drive IC 71 sequentially applies SWn to activate each touch cell 50. Preferably, the drive IC 71 applies the on / off control signal SWn separately from the position detection signal input section and the output section. In the position detection signal input section, the position detection signal is applied through the second signal line 44 and the TFT is turned on to provide the charging signal to the touch pad 55. If the soft touch input occurs or is being generated, the touch pad 55 is charged with a predetermined charge by the position detection signal. After a short period of rest after the position detection signal input section, SWn corresponding to the position detection signal output section is applied. In the position detection signal output section, the electric charge charged in the touch pad 55 is discharged through the second signal line 44, and the drive IC receives a signal received through the second signal line 44. The signal processor 73 generates an input signal by reading a delay time or a voltage or current level of the obtained signal.

Here, as shown in FIG. 21, each signal line 42, 44 is wired in an oblique direction with respect to the signal line 140 for screen display of the display device 20 indicated by a hidden line. Preferably, each of the signal lines 42 and 44 is wired in a zigzag form alternately shifted with respect to the signal line 140 of the display device 20.

According to the wiring structure of the signal line, an area in which the signal line 15 of the touch panel overlaps with the signal line 140 of the display device 20 hardly occurs. Therefore, the signal line 15 of the touch panel and the light blocking member 340 of the display device 20 do not overlap each other and the moiré can be avoided.

Meanwhile, the wiring structure of the signal line 15 as shown in FIG. 21 is not limited to the embodiment of FIG. 21, but may be applied to other embodiments described above. It can be applied to a touch cell circuit.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the technical field of the present invention without departing from the technical spirit of the present invention. It will be clear to those of ordinary knowledge.

1 is an exploded perspective view showing an example of a pressure touch input device

2 is a circuit diagram showing an embodiment of a pressure type touch cell

3 is a block diagram illustrating a system configuration of a touch input device according to the present invention.

4 is a waveform diagram illustrating an example of recognizing a touch input.

5 is a circuit diagram showing another embodiment of the pressure type touch cell

6 is a circuit diagram showing another embodiment of the pressure type touch cell

7 is a plan view showing the structure of a touch cell in the embodiment of FIG.

8 is a cross-sectional view showing a cross-sectional configuration cut along the line I-II in FIG.

9 is a circuit diagram showing another embodiment of the pressure type touch cell

10 conceptually depicts an example of the moiré phenomenon.

Figure 11 is an exploded perspective view showing an example in which the diffusion sheet is installed in accordance with the present invention

12 is a cross-sectional view showing an example in which the present invention is applied to a liquid crystal display device.

Figure 13 conceptually depicts an example in which the moiré phenomenon is solved according to the present invention.

14 is an exploded perspective view showing an example of a capacitive touch input device;

15 illustrates an example in which a capacitance is formed between the body and the touch pad.

16 is a circuit diagram showing an embodiment of a capacitive touch cell;

17 is a circuit diagram illustrating another embodiment of the capacitive touch cell.

18 is a waveform diagram illustrating an example of recognizing a touch input.

19 is an exploded perspective view showing an example in which the diffusion sheet is installed in accordance with the present invention;

20 is a circuit diagram illustrating a complex touch cell structure.

21 is a circuit diagram showing an example of wiring of a signal line according to the present invention;

<Explanation of symbols for the main parts of the drawings>

10 thin film element 15 signal line

20: display device 25: spacer

29: finger 30: substrate

35 switching element 35a first switching element

35b: second switching element 37: auxiliary signal line

38: gate signal line 40: first substrate

42: first signal line 44: second signal line

45: conductive pad 46: first conductive pad

48: second conductive pad 50: touch cell

51 drain electrode 52 source electrode

53: gate electrode 55: touch pad

59: contact hole 60: second substrate

62 conductive layer 66 gate insulating film

67: protective film 68: ohmic contact layer

69: active layer 70: touch position detection unit

71: drive IC 73: signal processor

74: timing controller 75: memory means

80: CPU 81: pressure touch cell

82 capacitive touch cell 83 first pressure signal line

84: pressure-type second signal line 86: capacitance-type first signal line

87: capacitive second signal line 88: capacitive third signal line

90: diffusion sheet 95: diffusion sheet

100: lower substrate 110: insulating substrate

120 thin film element 130 pixel electrode

140: signal line 200: liquid crystal layer

300: upper substrate 310: common electrode

320: overcoat 330: color filter

340: light blocking member 350: insulating substrate

400: lower polarizing plate 410: upper polarizing plate

Claims (2)

In the touch input device is installed on the display device 20, the touch input device for detecting the contact or approach of the touch means on the touch panel to generate an input signal corresponding to the point where the touch occurs, A touch cell 50 formed for each area in which a plurality of active areas in which touch input is made on the touch panel is divided; A plurality of signal lines 15 wired in the longitudinal or transverse direction on the touch panel and transmitting and receiving a position detection signal to the touch cell 50; A drive IC (71) for transmitting and receiving a position detection signal to the signal line (15); And And a signal processor 73 for generating an input signal from the position detection signal detected by the drive IC 71. The touch cell 50 can detect a multi-touch by touching a touch input for each touch cell, At least one signal line of the plurality of signal lines (15) is a touch input device, characterized in that arranged in an oblique direction to prevent optical interference with the signal line (140) for screen display of the display device (20). The method of claim 1, At least one signal line of the plurality of signal lines (15) is a touch input device, characterized in that arranged in a zigzag form.

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