KR101194662B1 - Method and device for detecting touch input - Google Patents

Abstract

The present invention relates to a touch input detection method and apparatus for providing a high writing resolution compared to the resolution of a touch cell, the touch input detection method of the present invention comprises the steps of (a) detecting the touch cell 50, the touch input ; (b) generating an input signal corresponding to the coordinate value of the touch cell when the touch cell 50 detected in the step (a) is isolated from the surroundings; And (c) generating an input signal corresponding to boundary point coordinate values of the detected touch cells 50 when two or more neighboring touch cells 50 are detected in step (a). The horizontal and vertical resolutions at the point where the touch input can be recognized are nearly doubled compared to the resolution of the touch cell, and the area capable of recognizing touch input is increased by almost 4 times and supports high handwriting resolution. It is easy to record text or draw an image.

Touch input device, touch cell, boundary point, resolution, pressure type, capacitive type

Description

Method and device for detecting touch input

The present invention relates to a method and apparatus for detecting a touch input, and more particularly, a horizontal resolution and a vertical resolution of a point where a touch input can be recognized are nearly doubled compared to the resolution of a touch cell in a cellular touch panel. The present invention relates to a touch input detection method and apparatus for easily writing a text or drawing an image with a touch input by supporting a high writing resolution.

Touch input detection devices (or “touch input devices”) are added on top of display devices such as liquid crystal displays (LCDs), plasma display panels (PDPs), organic light emitting diodes (OLEDs), and active matrix organic light emitting diodes (AMOLEDs). Or an input device designed to be embedded in a display device, and recognizes an input signal when an object such as a finger or a touch pen touches a screen. 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), It is used in all kinds of industries such as desktop computers using touch input operating systems, IPTV (Internet Protocol TV), 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 large number of missing signals, difficulty in recognizing an accurate touch point, and difficulty in detecting a multi-touch input. 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, recently, a cell type touch input device has been developed in which an active area in which touch input is made is divided into a matrix and a touch cell is configured for each divided area. The cell type touch input device configures the touch cell in various ways such as pressure type, capacitive type (or capacitive type), and optical type according to a detection method. For example, the pressure type configures the upper and lower electrodes for each unit touch cell, and generates an input signal corresponding to the coordinate value of the touch cell when the upper and lower electrodes are contacted by the touch pressure.

Such a cell-type touch input device has an advantage that fewer signals are missing and the coordinate value of the touch point can be detected accurately. In addition, the size of the touch panel can be designed relatively freely.

However, in the conventional cell type touch input device, it is technically difficult to narrow the cell width, and accordingly, there is a problem that the coordinates capable of recognizing the touch input are very small. Since the coordinates for recognizing the touch input are small, the writing resolution is also lowered, and it is difficult to write a text or draw an image through the touch input.

For example, the most recently released touch input device in a 3.5-inch full touch phone has a cell width of about 5 mm and a cell width under development of about 3 mm. For example, up to seven touch cells in a horizontal direction and eleven or less touch cells are disposed on a 3.5-inch touch screen. This means that the touch cell has a resolution of 7 * 11 and the handwriting resolution is also 7 * 11. In such a touch screen, it is not a big problem to select an icon or the like displayed by a GUI (Graphic User Interface) as a touch input. However, since the distance between the points for detecting the touch input is 3mm or more, it is very inconvenient to input a character such as letters, numbers, symbols, or draw an image.

1 illustrates an example of inputting a character in a conventional cell-type touch input detecting apparatus, and illustrates that the touch cell 10 is disposed at a resolution of 4 * 4. A circled portion in FIG. 1 is a contact portion 14 in which a touch means (or an end of a finger) such as a stylus pen or the like touches the touch cell 10. In FIG. 2, the right box is a screen display 15 of the display device when a character is input through the touch input device.

As shown in the figure, in the method of recognizing coordinate values for each touch cell 10, at least 4 * 3 matrix touch cells 10 are required in order to input “ga”. If the cell width is 3mm, space for 12mm in the horizontal direction and 9mm in the vertical direction will be required to enter "ga". As described above, the conventional cell-type touch input device requires a lot of space for inputting a character, and it is extremely difficult to record a character or draw an image with the touch input due to the small number of coordinates for recognizing the touch input.

The present invention has been proposed to solve the above problems, and when two or more neighboring touch cells are input at the same time or are input at a very short time difference, the touch signal is generated by generating an input signal corresponding to the boundary point coordinate value of the touch cells. Compared to the resolution of the cell, the resolution of the point where the touch input can be recognized is greatly increased, and the high handwriting resolution can be realized without physically reducing the cell width of the touch cell. It is an object of the present invention to provide a method and apparatus for detecting a touch input of a new method that can provide convenience.

In the touch input detection method of the present invention for achieving the above object, in the touch input detection method for detecting the touch input of the touch means from a touch panel having a plurality of touch cells 50, (a) touch input is Detecting the generated touch cell 50; (b) generating an input signal corresponding to the coordinate value of the touch cell when the touch cell 50 detected in the step (a) is isolated from the periphery; And (c) when two or more neighboring touch cells 50 are detected in the step (a), generating an input signal corresponding to the boundary point coordinate values of the detected touch cells 50.

According to an embodiment, the step (c) generates an input signal corresponding to the horizontal boundary point coordinate values of the two touch cells 50 when two touch cells 50 neighboring in the horizontal direction are detected. .

According to an embodiment, the step (c) generates an input signal corresponding to the vertical boundary point coordinate values of the two touch cells 50 when two touch cells 50 neighboring in the vertical direction are detected. .

According to one embodiment, the step (c) is a case where the touch cell 50 neighboring in the horizontal direction and the touch cell 50 neighboring in the vertical direction together with respect to any one touch cell 50, An input signal corresponding to the coordinate value of the point where the horizontal boundary line and the vertical boundary line intersect is generated.

According to one embodiment, the touch cell 50 is the conductive pad 45 of one substrate and the conductive layer 62 of the other substrate is energized when the two substrates (40, 60) facing each other. It is a pressure type touch cell to detect.

In the present embodiment, the touch cell 50 further includes a switching element 35 for switching the energization of the conductive pad 45.

In the present embodiment, the conductive pad 45 is composed of a pair of first conductive pads 46 and a second conductive pad 48 that are spaced apart from each other, and are in contact with the conductive layer 62. The pair of first conductive pads 46 and the second conductive pads 48 are energized with each other.

In the present embodiment, the touch cell 50 further includes a switching element 35 installed at the front end of the first conductive pad 46 or the rear end of the second conductive pad 48 to switch the connection of signals.

In the present embodiment, the touch cell 50 is provided at the front end of the first conductive pad 46 and the rear end of the second conductive pad 48, respectively, to switch the signal connection between the first switching element 35a and the first switch. It further comprises two switching elements 35b.

According to one embodiment, the touch cell 50 is a touch means made of a conductor 29 or a conductor having similar electrical characteristics to the touch pad 55 formed on one surface of the substrate 30 is a predetermined distance (d) ), A capacitive touch cell that detects a touch input by using a capacitance formed between the touch pad 55 and the touch means.

In the present embodiment, the touch cell 50 further includes a switching element 35 for switching the charging and discharging of the touch pad 55.

In the present embodiment, the touch cell 50 is an on / off control terminal is connected to the touch pad 55, a three-terminal switching device having a different output signal according to the potential of the touch pad 55 (35) is further included.

In the present embodiment, the touch cell 50 has an output terminal connected to the touch pad 55, and is turned on / off according to a control signal applied to an on / off control terminal to charge the touch pad 55 with a charging voltage. A three-terminal first switching element 35a for supplying the first and second terminals; And an on / off control terminal connected to the touch pad 55 and having a three-terminal second switching element 35b having different output signals according to the potential of the touch pad 55.

The touch input detection device of the present invention for achieving the above object, the touch input detection device for implementing the above-described touch input detection method, a panel in which a plurality of touch cells 50 are arranged in a matrix form; A drive IC (71) for transmitting and receiving a position detection signal to each of the touch cells (50); And a signal processor 73 generating an input signal corresponding to the boundary point coordinate value of the touch cell 50 or the touch cell 50 from the position detection signal detected by the drive IC 71.

According to the touch input detection method and apparatus of the present invention, when a touch input is detected in a single touch cell, the coordinate value of the corresponding touch cell is obtained, and when the touch input is detected from two or more neighboring touch cells, By generating the input signal by acquiring the boundary point coordinate value, the resolution of the point where the touch input can be recognized can be nearly doubled in the horizontal and vertical directions, respectively, compared to the resolution of the actual touch cell, and thus the cell width of the touch cell. It is possible to implement high touch input point resolution and handwriting resolution without narrowing the size, and to easily write texts and draw images on a cellular touch screen, and to enhance user convenience.

In addition, the present invention enables to recognize multi-touch inputs, and is not only suitable for applications that support multi-touch inputs, but also facilitates the development of such applications, and in particular, multi-board simultaneous writing on an electronic blackboard or on a single touch screen. Many users can run an application or play a game at the same time.

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

First, the present invention relates to a touch input detection method and apparatus installed in addition to the upper surface of a display device such as LCD, PDP, OLED, AMOLED, or embedded in the display device, wherein the touch cells formed by dividing the active area into a matrix form. A cell type touch input device is arranged. The present invention utilizes a boundary point of touch cells as a region capable of recognizing touch input in a cell-type touch input device, thereby greatly increasing the resolution of a point at which a touch input can be recognized compared to the resolution of a touch cell, and providing a high writing resolution. to provide.

Hereinafter, some embodiments of the cellular touch panel will be first described in order to facilitate understanding of the present invention, and then the touch input detection method of the present invention will be described. Although the embodiments mentioned below relate to a touch panel having a pressure touch cell structure and a capacitive touch cell structure, the technical idea of the present invention is not limited to these embodiments, and may be optically or otherwise touched. It will be apparent to those skilled in the art that the present invention can be applied to all of the cellular touch input devices that detect the.

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. Conversely, when a part is "directly over" another part, it means that there is no other part in the middle.

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.

2 is an exploded perspective view showing the configuration of a pressure type touch input device. As illustrated, a touch panel is installed on the upper surface of the display device 20. Here, 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.

The touch panel includes a first substrate 40 and a second substrate 60 which are disposed to face each other, and a drive IC 71 is mounted on an edge of one of the substrates. 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.

In the example of FIG. 2, the touch panel is installed in addition to the upper surface of the display device 20, but the touch panel may be installed in the display device 20. Further, the first substrate 40 or the second substrate 60 is the same substrate as the substrate constituting the display device 30 (for example, a TFT substrate or a color filter substrate of a liquid crystal panel, or a TFT substrate or an encapsulation substrate of an AMOLED). Can be. In this case, the TFT substrate or the color filter substrate may be provided with components for screen display and components for touch input detection.

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 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. Although not shown, a spacer such as a ball spacer or a pattern spacer is provided between the two substrates.

3 illustrates a circuit configuration of a pressure type touch cell. In FIG. 3, 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 formed in a row or column direction, or is divided into unit touch cells 50 as shown in FIG. 3. Is formed. As shown in FIG. 3, when the conductive layer 62 is partitioned for each unit touch cell 50, each touch cell 50 is connected to a pad to pad, and is adjacent to a neighboring touch cell 50. Can be electrically disconnected. That is, by separating only the signals transmitted to each touch cell 50, it is possible to prevent the signal from flowing back to the other touch cell 50 and to recognize the multi-touch input.

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. The wiring directions of the first signal line 42 and the second signal line 44 are not limited to the examples shown and do not necessarily have to cross each other. 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. On the other hand, the lower layer is made of a material having excellent contact characteristics with ITO (Indium Tion Oxide) and IZO (Indium Zinc Oxide), 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.

4 is a block diagram illustrating a system configuration of a touch input detection device of the present invention, and FIG. 5 is a waveform diagram illustrating an example of recognizing a touch input in the embodiment of FIG. 3. Referring to FIG. 4, 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 detection device itself. Although not shown, the system configuration further includes a power supply for generating a low or low voltage of signals for touch input detection.

The timing controller 74 generates a time division signal of several tens of ms or less, and 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 the signal processor 73 is in a "Busy" state in the course of processing many 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. 5, 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. 3, the signal S3 may be obtained through the second right signal line 44 at the rightmost time at t3 to t4 time. In this case, the signal processor 73 generates an input signal corresponding to the coordinate values "D3 and S3" of the touch cell 50.

6 shows another embodiment of a pressure touch cell. Referring to FIG. 6, in contrast to the embodiment of FIG. 3, 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 at predetermined intervals. 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.

7 and 8 illustrate another circuit configuration of the pressure type touch cell, and show an example of switching a signal in each touch cell 50 using a switching element.

Referring to FIG. 7, 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 without loss of voltage or current applied to input terminal when current is applied to control terminal, and BJT applies voltage higher than threshold voltage of base to base. When current flows to the base terminal in a state, 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, a current flowing through the input terminal to the output terminal while conducting is applied to the gate terminal. 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.

Referring to FIG. 7, a plurality of gate signal lines 38 are further disposed on an upper surface of the first substrate 40. The drive IC 71 applies a gate signal Gn to each of the gate signal lines 38. In each touch cell 50, the gate terminal of the TFT 35 is connected to the gate signal line 38, the drain terminal as the input terminal is connected to the second conductive pad 48 and the source terminal as the output terminal is the second signal line. It is connected to 44.

In the embodiment of FIG. 7, the gate signal Gn is sequentially applied to selectively activate only the touch cells 50 for detecting the touch input, and deactivate other touch cells 50. For example, G2 and G3 apply an off signal when G1 applies an on 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.

On the other hand, although Fig. 7 refers to the connection relationship of the TFTs 35, 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.

8 shows another circuit configuration of the touch cell 50. Referring to FIG. 8, 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 of FIG. 7, and the circuit configuration of the first TFT 35a is configured to connect the gate terminal 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. Therefore, 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.

The touch input device constituting the touch cell 50 in a pressure manner has been described above. Next, a touch input device constituting the touch cell 50 in a capacitive manner 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 device 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. 9, the capacitive touch input device may configure a panel using a single substrate. In FIG. 9, a configuration in which the substrate 30 is installed on the upper surface of the display device 20 such as an LCD or an AMOLED is illustrated. However, the substrate 30 may be embedded in the display device 20. In addition, any substrate constituting the display device 20 may be configured as a touch panel. For example, components for detecting touch input may be mounted on an upper surface of a color filter substrate of an LCD or an encapsulation substrate of an AMOLED.

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. 10. Referring to FIG. 10, 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. 10. 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.

11 is a circuit diagram illustrating an 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. 11, 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.

12 is a circuit diagram illustrating another embodiment of the capacitive touch cell. Referring to FIG. 12, 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. .

FIG. 13 is a waveform diagram illustrating an example of obtaining a touch signal in the embodiment of FIG. 12. 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. 13, 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 in FIG. 12 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. 13, if a touch occurs in a section in which G3 is at the Hi level, the charging voltage may be changed 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. 13, 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".

11 and 12 illustrate embodiments in which each touch cell 50 may be electrically disconnected from other touch cells 50 by a TFT, thereby recognizing a multi-touch input. 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.

14 is a flowchart illustrating a process of detecting a touch input according to the present invention, and FIG. 15 is a diagram illustrating an example of character input according to the touch input detection method of the present invention. With reference to this, an embodiment of increasing the resolution of the point that can recognize the touch input compared to the resolution of the touch cell 50 will be described. In FIG. 15, the left box conceptually depicts a touch input device in which the touch cell 50 is disposed at a resolution of 4 * 4, and the right box is a screen on which characters are displayed on the screen of the display device 20 by touch input. The display 25 is illustrated. Reference numeral 39 denotes a contact portion 39 of the touch means.

The embodiments described below correspond to both the case of not supporting the multi-touch input (or deactivating the multi-touch input in the handwriting input mode even if the multi-touch input is supported) and the case of supporting the multi-touch input. In the following description, that the touch cell 50 is “isolated from the periphery” means that the other touch cell 50 adjacent to the touch cell 50 where the touch input is detected is not detected. In addition, "when two or more neighboring touch cells 50 are detected" means that the touch cells 50 adjacent to each other in the horizontal or vertical direction are detected with a very short time difference (when the multi-touch input is not supported). , Refers to a state detected simultaneously (when multi-touch input is supported).

If the touch input device does not support multi-touch input, only one touch cell 50 will be recognized even when two or more touch cells 50 are touched at the same time. In this case, the detected touch cell 50 is always in an isolated state from the surroundings. In a handwriting input state such as writing a character or drawing an image, the touch input moves from one touch cell 50 to another adjacent touch cell 50. At this time, in the present invention, if the touch input stays in any one of the touch cells 50, the touch cell 50 is recognized as the touch cell 50 isolated from the surroundings. When a touch input moves from one touch cell 50 to another neighboring touch cell 50 in the process of writing, a very short time difference (for example, a difference in time taken to detect one touch input) is measured. The two neighboring touch cells 50 will be continuously detected. In this case, it is recognized that two or more neighboring touch cells 50 are detected.

If the touch input device supports multi-touch input as in the above-described exemplary embodiments, all of the two or more touch cells 50 may be recognized at the same time. Therefore, in an environment supporting multi-touch input, it is easy to identify whether the touch cell 50 is isolated from the surroundings and whether two or more neighboring touch cells 50 are detected at the same time. However, even in the case of supporting multi-touch input, in the situation where the iron writing device having a very small cross-sectional area is in contact with the capacitive touch cell, the touch means and the touch pad 55 when the steel writing device contacts the boundary points of the two touch cells 50. ), An opposing area of two) may not be detected at the same time. In this case, as described above, when the two touch cells 50 are continuously detected with a very short time difference, it is recognized that two neighboring touch cells 50 are detected together.

Referring to FIG. 14, the step begins by detecting the touch cell 50 in which the touch input has occurred (ST110). As mentioned above, the signal processing unit 73 applies a position detection signal to the first signal line 42 and receives a detection signal such as a voltage or a current to the second signal line 44 to generate a touch cell. (50) is detected. 3, 6 and 11, by scanning Dn applied through the first signal line 42, each touch cell 50 is sequentially activated (such as making a touch input detectable). 7, 8, and 12, each touch cell 50 is sequentially activated by scanning Gn applied through the gate signal line 38. Referring to FIG. Then, Sn is obtained from the activated touch cells 50 to detect the touch cell 50 in which the touch input has occurred.

As a next step, it is determined whether the detected touch cell 50 is isolated from the surrounding (ST120). If the detected touch cell 50 is isolated from the surroundings, an input signal corresponding to the coordinate value of the corresponding touch cell 50 is generated (ST130). For example, if the upper left touch cell 50 is detected in FIG. 15 (hereinafter, the position of the touch cell will be described using coordinates of Hn in the row direction and Vn in the column direction). It is determined whether the touch cell 50 is isolated, and in step ST130, an input signal corresponding to the coordinate values of "H1, V1" is generated.

As a next step, it is determined whether two or more neighboring touch cells 50 are detected (ST140). If two or more neighboring touch cells 50 are detected, an input signal corresponding to boundary point coordinate values of the touch cells 50 is generated (ST150). For example, in FIG. 15, the contact portion 39 of the second touch input for inputting the letter “ga” is a boundary between the touch cell 50 having the “H1, V1” coordinates and the touch cell 50 having the “H1, V3” coordinates. Located at the point. Accordingly, it is determined that two neighboring touch cells 50 are detected in step ST140, and generates an input signal corresponding to the coordinate values of "H1, V2" which are boundary points of the two touch cells 50 in step ST150. .

In step ST140, when two touch cells 50 neighboring in the horizontal direction are detected, an input signal corresponding to the horizontal boundary point coordinate values of the two touch cells 50 is generated. For example, in FIG. 15, the second touch input for inputting the letter "ga" is recognized as an input signal of the coordinate values "H1, V2". In addition, when two touch cells 50 adjacent to each other in the vertical direction are detected, an input signal corresponding to the vertical boundary point coordinate values of the two touch cells 50 is generated. For example, in FIG. 15, the sixth touch input for inputting the letter "ga" is recognized as an input signal having the coordinate values "H2, V3". In addition, when the touch cell 50 neighboring in the horizontal direction and the touch cell 50 neighboring in the vertical direction are detected together with respect to any one touch cell 50 (that is, three points centered around the intersection point in FIG. 15). (Eg, when two touch cells 50 are detected together or four touch cells 50 are detected together), an input signal corresponding to a coordinate value of a point where a horizontal boundary line and a vertical boundary line intersect is generated. For example, in FIG. 15, the seventh touch input for inputting the letter "ga" is recognized as an input signal having the coordinate values "H2, V4".

Meanwhile, the touch input detection method illustrated in FIG. 14 may be applied to a case where a remote multi-touch input occurs. If a multi-touch input occurs at a remote point, a plurality of remote touch cells 50 will be detected simultaneously in step ST110. In this case, steps ST120 to ST150 proceed with respect to each of the detected touch cells 50.

For example, suppose that the first touch input for inputting the letter "a" and the fifth touch input for inputting the letter "d" occur simultaneously in FIG. 15. In this case, an input signal having the coordinate values "H1, V1" is generated through steps ST120 and ST130 for the first touch input of the letter "A", and steps ST140 and ST150 for the fifth touch input of the letter "D". The input signal of coordinate value "H6, V6" is produced | generated.

Referring to the screen display 25 of FIG. 15, four characters are input through a touch screen in which the touch cell 50 is disposed at a resolution of 4 * 4. That is, in the arrangement of the conventional 4 * 4 resolution touch cell 50 as in the example shown in FIG. 1, it can be seen that the handwriting resolution is greatly increased by the touch input detection method of the present invention, compared to only one character can be input. have. This is because although the touch cell 50 is disposed at a resolution of 4 * 4, when the touch input detection method of the present invention is applied, the resolution of the point where the touch input can be recognized is increased to 7 * 7.

Here, the example illustrated in FIG. 15 illustrates that the touch cell 50 is disposed at a resolution of 4 * 4 to help the understanding of the present invention. However, the touch input device will actually have a touch cell 50 of higher resolution. For example, if the touch cell 50 is disposed at a cell width of 3 mm on the touch screen of the 3.5-inch mobile terminal, the touch cell 50 may be disposed at a resolution of 13 * 29. In a monitor of a notebook or desktop computer, even if the cell width is 5 mm or more, dozens of touch cells 50 may be arranged in rows and columns, respectively.

Predict that the touch input detection method of the present invention is applied to a touch input device in which a touch cell 50 having a cell width of 3 mm is disposed at a resolution of 13 * 29. The resolution of the point where the touch input can be recognized is increased to 25 * 57. That is, the resolution is nearly doubled in the horizontal and vertical directions, respectively, and effectively reduces the cell width by half without physically reducing the cell width.

If the resolution of the touch input point is increased, the GUI supporting the touch input may also be implemented at a higher resolution. Above all, the handwriting resolution is increased in the cellular touch input device, and it is very easy to record characters such as letters, numbers, and symbols, or draw images such as figures and drawings, Convenience will be enhanced.

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 a view showing an example of character input in a conventional cell-type touch input detection device

2 is an exploded perspective view showing an example of a pressure type touch input detection device;

Figure 3 is a circuit diagram showing an embodiment of a pressure type touch cell

4 is a block diagram illustrating a system configuration of a touch input detection device of the present invention.

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

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

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

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

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

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

11 is a circuit diagram illustrating an embodiment of a capacitive touch cell.

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

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

14 is a flowchart illustrating a process of detecting a touch input according to the present invention.

15 is a view showing a character input example in the present invention

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

20: display device 25: screen display

29: finger 30: substrate

35 switching element 35a first switching element

35b: second switching element 37: auxiliary signal line

38 gate signal line 39 contact portion

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 55: touch pad

60: second substrate 62: conductive layer

70: touch position detector 71: drive IC

73: signal processor 74: timing controller

75: memory means 80: CPU

Claims (14)

delete delete delete delete delete delete delete delete delete In the touch input detection method for detecting a touch input of the touch means from a touch panel having a plurality of touch cells 50, (a) detecting a touch cell 50 in which a touch input has occurred; (b) generating an input signal corresponding to the coordinate value of the touch cell when the touch cell 50 detected in the step (a) is isolated from the surroundings; And (c) when two or more neighboring touch cells 50 are detected in the step (a), generating an input signal corresponding to the boundary point coordinate values of the detected touch cells 50; The touch cell 50 is a touch means made of a finger 29 of the body or a conductor having similar electrical characteristics to the touch pad 55 formed on one surface of the substrate 30 approaches a predetermined distance (d), Touch input detection method which is a capacitive touch cell for detecting a touch input by using the capacitance formed between the touch pad (55) and the touch means. The method of claim 10, The touch cell (50) is a touch input detection method comprising a three-terminal switching device for switching the charge and discharge of the touch pad (55). The method of claim 10, The touch cell 50 includes an on / off control terminal connected to the touch pad 55 and a three-terminal switching element 35 having different output signals according to the potential of the touch pad 55. Touch input detection method. The method of claim 10, The touch cell 50, An output terminal is connected to the touch pad 55, and is turned on / off according to a control signal applied to an on / off control terminal to supply a charging voltage to the touch pad 55. 35a); And And a third terminal type switching device 35b having an output signal different from each other according to the potential of the touch pad 55 connected to an on / off control terminal of the touch pad 55. Input detection method. A touch input detection device for implementing the touch input detection method of any one of claims 10 to 13, A panel in which the plurality of touch cells 50 are arranged in a matrix form; A drive IC (71) for transmitting and receiving a position detection signal to each of the touch cells (50); And And a signal processor 73 for generating an input signal corresponding to the boundary point coordinate value of the touch cell 50 or the touch cell 50 from the position detection signal detected by the drive IC 71. Touch input detection device.

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