JP2009116224A - Touch panel integrated type liquid crystal display device, touch detecting method and portable terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make the touch panel integrated type liquid crystal display device thin, and to lower the cost of a touch panel integrated type liquid crystal display device by simplifying the circuit constitution. <P>SOLUTION: A segment electrode SEG1 is selected and a signal for touch detection for detecting a touch position of a finger 24 of a person is applied. The signal for touch detection appears as a touch signal at a segment electrode SEG2 and a segment electrode SEG3 through the finger 24 of the person (through a coupling electrostatic capacitor C). The touch signal is detected to detect the touch position of the finger of the person. Consequently, the touch position of the finger of the person can be detected using the segment electrodes that the liquid crystal display device has as they are. Consequently, the need for a conventional touch panel is eliminated and then the touch panel integrated type liquid crystal display device is made thin and has its circuit constitution simplified to lower the cost. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device integrated with a touch panel, and in particular, can directly detect a position where a human finger or the like touches (contacts) a display screen by using an electrode included in a conventional liquid crystal display device as it is. The present invention relates to a touch panel integrated liquid crystal display device, a touch detection method, and a portable terminal.

  In recent years, a liquid crystal display device integrated with a touch panel in which a liquid crystal display device and a touch panel are integrated is often used. In this touch panel integrated liquid crystal display device, an input operation to a computer can be performed by touching the screen with a finger or the like, and it is actively used in bank ATMs, station ticket machines and the like.

  By the way, the conventional touch panel integrated liquid crystal display device has a structure in which a separate touch panel is arranged on the liquid crystal display screen, and the touch panel is superimposed on the liquid crystal display panel. there were. In addition, a circuit for a liquid crystal display device and an output circuit for a touch panel are required individually, which increases the cost. For this reason, as the liquid crystal display device is reduced in size and weight, the touch panel integrated liquid crystal display device is also required to be thinner and lighter.

A conventional touch panel integrated liquid crystal display device for solving such a problem has been disclosed (see Patent Document 1). The touch panel integrated liquid crystal display device of Patent Document 1 aims to simplify the structure while ensuring the visibility as a display by integrating a display panel and a touch panel. For this purpose, a PDLC layer is formed by dispersing a liquid crystal phase in a transparent resin phase sandwiched between two glass substrates. Further, transparent electrodes are formed inside the glass substrate, and leakage current detecting means is provided on these transparent electrodes. When the glass substrate is pressed, the steady current of the transparent electrode increases, and the value is detected. Thus, the liquid crystal display panel itself has a touch panel function.
JP 2000-172437 A

  As described above, the conventional touch panel integrated liquid crystal display device has a structure in which the touch panel is overlaid on the liquid crystal display panel, which increases the thickness and weight. In addition, a circuit for a liquid crystal display device and an output circuit for a touch panel are required separately, which increases the cost.

  Further, in the liquid crystal display device integrated with the touch panel of Patent Document 1, since a change in the current value when the glass substrate is pressed is detected, a circuit for detecting the change in the current value is obtained, and the circuit becomes complicated. There was a problem. In addition, in order to change the current value, it is necessary to press the crow substrate strongly to some extent. When the glass substrate is strongly pressed, the display color of the pressed portion changes. It was.

  The present invention has been made in view of such circumstances, and an object of the present invention is to eliminate the need for a conventional touch panel, to reduce the thickness of the touch panel integrated liquid crystal display device, and to reduce the cost by simplifying the circuit. A touch panel integrated liquid crystal display device, a touch detection method, and a portable terminal capable of performing an input operation with a light touch on a display screen.

The present invention has been made to solve the above problems, and the touch panel integrated liquid crystal display device of the present invention displays the liquid crystal phase by a plurality of planar electrodes arranged in parallel on the surface of the liquid crystal phase. A touch panel integrated liquid crystal display device in which a touch panel function is added to the liquid crystal display device to be driven, and when an object such as a dielectric or conductor including a human finger touches the display screen of the liquid crystal display device, The touch position is detected by detecting a change in capacitance between the planar electrodes at a position corresponding to a portion of the display screen touched by the object.
In the touch panel integrated liquid crystal display device of the present invention having the above-described configuration, the electrodes included in the conventional liquid crystal display device are used as they are, and a change in capacitance between the electrodes when a human finger touches the display screen is detected. To detect the touch position.
This eliminates the need for a conventional touch panel, thereby reducing the thickness of the touch panel integrated liquid crystal display device and reducing the cost by simplifying the circuit. Further, an input operation can be performed with a light touch on the display screen.

In the touch panel integrated liquid crystal display device of the present invention, the liquid crystal display device is composed of an STN liquid crystal display device, and a plurality of transparent electrodes serving as segment electrodes are arranged on the surface of the liquid crystal phase. When the object touches on the display screen, the touch position is detected by detecting a change in capacitance between the segment electrodes corresponding to the position touched by the object. It is characterized by.
In the touch panel integrated liquid crystal display device of the present invention configured as described above, when an object touches the display screen in the STN liquid crystal display device, a change in capacitance between segment electrodes corresponding to the touched position is detected. To detect the touch position.
Thereby, in the STN liquid crystal display device, the touch position can be detected using the segment electrode as it is. For this reason, the conventional touch panel becomes unnecessary, and the touch panel integrated liquid crystal display device can be thinned and the cost can be reduced by simplifying the circuit. Further, an input operation can be performed with a light touch on the display screen.

In the touch panel integrated liquid crystal display device of the present invention, a plurality of transparent electrodes serving as segment electrodes are arranged on one surface side of the liquid crystal phase, and a transparent electrode serving as a common electrode is disposed on the other surface side. A plurality of segment electrodes are arranged in a direction perpendicular to the segment electrodes.
The touch panel integrated liquid crystal display device of the present invention having the above-described configuration is an STN liquid crystal display device, wherein a plurality of segment electrodes are arranged on one surface side of the liquid crystal phase, and a common electrode is a segment electrode on the other surface side. Are arranged in a direction orthogonal to each other.
Thus, in the STN liquid crystal display device, the touch position can be detected using the segment electrode as it is, and the touch position can be detected using the common electrode if desired. For example, the touch position is detected by arranging the common electrode on the display screen side.

The touch panel integrated liquid crystal display device according to the present invention includes an LCD driving unit that applies a liquid crystal driving voltage for driving a liquid crystal phase to each segment electrode, and one or more segment electrodes selected from the segment electrodes. , A touch detection signal output unit for applying a touch detection signal for detecting a touch position of the object, and one or a plurality of segment electrodes are selected from the segment electrodes, and the touch detection signal is A touch signal detection unit that detects a touch signal through the touched object, and a touch position determination unit that determines a touch position of the object based on the touch signal detected by the touch signal detection unit. Features.
In the touch panel integrated liquid crystal display device of the present invention configured as described above, the LCD driving unit applies a liquid crystal driving voltage to each segment electrode. The touch detection signal output unit selects a segment electrode and applies a touch detection signal for detecting the touch position of the object to the segment electrode. Then, the touch signal detection unit detects the touch signal from the selected segment electrode (for example, the electrode adjacent to the segment electrode to which the touch detection signal is applied), and determines the touch position of the object.
Thereby, in the STN liquid crystal display device, the touch position can be detected using the segment electrode as it is. For this reason, the conventional touch panel becomes unnecessary, and the cost can be reduced by thinning the touch panel integrated liquid crystal display device and simplifying the circuit. Further, an input operation can be performed with a light touch on the display screen.

Also, the touch panel integrated liquid crystal display device of the present invention alternately provides an LCD display period in which a liquid crystal driving voltage is applied to the segment electrode from the LCD driving unit and a position detection period in which the application of the liquid crystal driving voltage is suspended. During the position detection period, the touch detection signal output unit selects one or a plurality of segment electrodes from the segment electrodes and applies a touch detection signal for detecting the touch position of the object. The touch signal detection unit transmits the touch detection signal from one or more segment electrodes located adjacent to or in the vicinity of the segment electrode selected by the touch detection signal output unit via the touched object. It is configured to detect as a touch signal.
In the touch panel integrated liquid crystal display device of the present invention having the above-described configuration, the LCD display period in which the liquid crystal driving voltage is applied to the segment electrodes from the LCD driving unit and the position detection period in which the liquid crystal driving voltage is stopped are alternately applied. And a touch position is detected in this position detection period.
Thereby, the touch position can be detected without being affected by the liquid crystal driving voltage.

The touch panel integrated liquid crystal display device of the present invention constantly applies a liquid crystal driving voltage from the LCD driving unit to the segment electrodes, and the touch detection signal output unit receives one or more of the segment electrodes from the segment electrodes. A touch detection signal for selecting a segment electrode and detecting a touch position of the object is superimposed on the liquid crystal driving voltage, and the touch signal detection unit is selected by the touch detection signal output unit. The touch detection signal is detected as a touch signal via the touched object from one or a plurality of segment electrodes located adjacent to or near the segment electrode.
In the touch panel integrated liquid crystal display device of the present invention having the above-described configuration, a liquid crystal driving voltage is constantly applied to the segment electrode from the LCD driving unit, and the touch detection signal output unit applies touch detection to the selected segment electrode. A signal is applied while being superimposed on the liquid crystal driving voltage.
As a result, the touch position can be detected without affecting the display state of the liquid crystal display screen (for example, display flicker).

In the touch panel integrated liquid crystal display device of the present invention, the touch signal detection unit is configured to detect a touch signal from all the electrodes of the segment electrode, and the touch position determination unit is configured to detect the touch detection signal. The touch position is determined based on touch signals detected by other segment electrodes excluding the segment electrode to which is applied.
In the touch panel integrated liquid crystal display device of the present invention having the above-described configuration, the touch signal detection unit detects touch signals of all the segment electrodes. In this case, for the segment electrode to which the touch detection signal is applied, the touch signal detected from the segment electrode is excluded, and the touch position is determined based on the touch signal detected by the other segment electrode.
Thereby, the circuit configuration of the touch signal detection unit can be simplified.

The touch panel integrated liquid crystal display device of the present invention is characterized in that a touch position is detected by the common electrode instead of the segment electrode.
Thereby, a touch position in a direction perpendicular to the segment electrode can be detected.

In the touch panel integrated liquid crystal display device of the present invention, the liquid crystal display device is configured by a TFT liquid crystal display device, and is configured by using the source line of the TFT liquid crystal display device instead of the segment electrode. , Feature.
Thereby, the technical idea of the present invention can also be applied to a TFT liquid crystal display device.

The touch detection method of the present invention is a liquid crystal display device in which a touch panel function is added to a liquid crystal display device that displays and drives the liquid crystal phase by a plurality of planar electrodes arranged in parallel on the surface of the liquid crystal phase. A touch detection method in an apparatus, wherein when an object such as a dielectric or a conductor including a human finger touches a display screen of the liquid crystal display device, a position corresponding to a portion of the display screen touched by the object The touch position is detected by detecting a change in capacitance between the planar electrodes.
In the touch detection method of the present invention including the above-described procedure, the electrodes included in the conventional liquid crystal display device are used as they are, and a change in capacitance between the electrodes when a human finger touches the display screen is detected to perform the touch. Detect position.
This eliminates the need for a conventional touch panel, thereby reducing the thickness of the touch panel integrated liquid crystal display device and reducing the cost by simplifying the circuit. Further, an input operation can be performed with a light touch on the display screen.

In the touch detection method of the present invention, a plurality of transparent electrodes to be segment electrodes are arranged on one surface side of the liquid crystal phase, and a transparent electrode to be a common electrode is orthogonal to the segment electrodes on the other surface side. When a plurality of STN liquid crystal display devices arranged in the direction are used and the object touches the display screen of the liquid crystal display device, the capacitance between the segment electrodes corresponding to the position touched by the object is determined. The touch position is detected by detecting a change.
In the touch detection method of the present invention including the above procedure, when an object touches the display screen in the STN liquid crystal display device, a change in capacitance between segment electrodes corresponding to the touched position is detected, and the touch is performed. Detect position.
Thereby, in the STN liquid crystal display device, the touch position can be detected using the segment electrode as it is. For this reason, the conventional touch panel becomes unnecessary, and the touch panel integrated liquid crystal display device can be thinned and the cost can be reduced by simplifying the circuit. Further, an input operation can be performed with a light touch on the display screen.

In the touch detection method of the present invention, an LCD driving procedure for applying a liquid crystal driving voltage for displaying and driving a liquid crystal phase to each segment electrode, and one or a plurality of segment electrodes are selected from the segment electrodes, and the object is selected. A touch detection signal output procedure for applying a touch detection signal for detecting the touch position of the touch panel, and one or a plurality of segment electrodes are selected from the segment electrodes, and the touch detection signal is used as the touched object. A touch signal detection procedure for detecting the touch position of the object based on the touch signal detected by the touch signal detection procedure. .
In the touch detection method of the present invention including the above procedure, a liquid crystal driving voltage is applied to each segment electrode by the LCD driving procedure. Further, according to the touch detection signal output procedure, a segment electrode is selected, and a touch detection signal for detecting the touch position of the object is applied to the segment electrode. Then, by the touch signal detection procedure, the touch signal is detected from the selected segment electrode (for example, the electrode adjacent to the segment electrode to which the touch detection signal is applied), and the touch position of the object is determined.
Thereby, in the STN liquid crystal display device, the touch position can be detected using the segment electrode as it is. For this reason, the conventional touch panel becomes unnecessary, and the cost can be reduced by thinning the touch panel integrated liquid crystal display device and simplifying the circuit. Further, an input operation can be performed with a light touch on the display screen.

Moreover, the portable terminal of this invention is equipped with the touchscreen integrated liquid crystal display device in any one of said.
Thereby, thickness reduction and weight reduction of a portable terminal can be achieved.

  In the touch panel integrated liquid crystal display device of the present invention, the touch position can be detected by using the electrodes of the conventional liquid crystal display device as they are, so that the conventional touch panel becomes unnecessary, and the touch panel integrated liquid crystal display is provided. Cost reduction can be achieved by thinning the device and simplifying the circuit. Further, an input operation can be performed with a light touch on the display screen.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

[Description of Structure of Touch Panel Integrated Liquid Crystal Display]
FIG. 1 is a diagram showing the structure of a touch panel integrated liquid crystal display device according to an embodiment of the present invention. The configuration itself shown in FIG. 1 is the same as that of a conventional simple matrix system. The present invention is characterized in that hardware such as an ITO electrode provided in a conventional liquid crystal display device is used as it is, and a touch panel function is integrated into the liquid crystal display device.

The configuration shown in FIG. 1 is the same as that of a general liquid crystal display device and is well known, but will be described only briefly.
FIG. 1A shows a front view of a touch panel integrated liquid crystal display device, and FIG. 1B shows a cross-sectional view.

  As shown in FIG. 1 (B), the touch panel integrated liquid crystal display device has a lower light shielding plate 11, a B glass 12, a lower transparent electrode 13, a liquid crystal phase 14, an upper transparent electrode 15, and an A glass 16 in order from the lower side. The upper light shielding plate 17 is laminated. The lower transparent electrode 13 is formed on the upper side of the B glass 12, and the upper transparent electrode 15 is formed on the lower side of the B glass 12. The liquid crystal phase 14 is filled in a space formed by the B glass 12, the A glass 16, and the sealing agent 18.

  In addition, as shown in FIG. 1A, a plurality of lower transparent electrodes (common electrodes) COM1 to COM6 serving as common electrodes and a plurality of upper transparent electrodes (segment electrodes) SEG1 to SEG5 serving as segment electrodes are orthogonal to each other. The structure is arranged in a matrix.

  In the example shown in FIG. 1A, an example in which there are six common electrodes and five segment electrodes is shown, but in reality, a large number of electrodes are arranged at a minute interval (for example, several hundreds of microns). .

  Hereinafter, the lower transparent electrode is referred to as a common electrode, and the upper transparent electrode is referred to as a segment electrode. The common electrodes COM1 to COM6 are collectively referred to as the common electrode 13, and the segment electrodes SEG1 to SEG5 are collectively referred to as the segment electrode 15.

  In FIG. 1A, the driver IC 21 is connected to each common electrode 13 by a common wiring 22 and is connected to each segment electrode 15 by a segment wiring 23. The driver IC 21 applies a liquid crystal driving voltage to the selected common electrode 13 and also applies a liquid crystal driving voltage to the selected segment electrode 15. As a result, the portion of the intersection of the selected common electrode 13 and the selected segment electrode 15, for example, the portion indicated by symbol a is lit. A signal waveform applied to the segment electrode 15 and the common electrode 13 is shown in FIG.

[Description of Touch Detection Principle in Touch Panel Integrated Liquid Crystal Display Device of the Present Invention]
Next, the principle of touch detection in the touch panel integrated liquid crystal display device of the present invention will be described. FIG. 2 is a diagram for explaining the principle of touch detection in the touch panel integrated liquid crystal display device of the present invention.

  As shown in FIG. 2A, when a potential difference is generated between the segment electrodes SEG1, SEG2, and SEG3, an electric field E is generated between the segment electrodes. That is, electrostatic induction occurs between the segment electrodes, but there are almost no opposing surfaces between the segment electrodes SEG1, SEG2, and SEG3, and the coupling capacitance between the segment electrodes is extremely small. For this reason, the influence which the adjacent segment electrode receives by the voltage applied to one segment electrode is very small.

  However, as shown in FIG. 2B, when the upper light shielding plate 17 is touched with the finger 24 or the like, a coupling capacitance C is generated between the segment electrodes SEG1, SEG2, and SEG3 and the finger 24. Due to the combined capacitance C, the segment electrodes SEG1, SEG2, and SEG3 located in the vicinity of the finger 24 are mutually affected by the combined capacitance C. (Note that the object of touch detection is not limited to a human finger, and may be a dielectric or a conductor.)

  Therefore, for example, a touch detection signal (for example, a high-frequency signal having a predetermined frequency) for detecting the position of the finger touch is applied to one segment electrode SEG1. The touch signal is detected through the coupling capacitance C at the adjacent segment electrode SEG2 or the adjacent segment electrode SEG3. Thereby, when the human finger 24 touches the upper part of the segment electrode SEG1 to which the touch detection signal is applied or the vicinity thereof, the touch signal can be detected at the adjacent segment electrode SEG2 or the adjacent segment electrode SEG3. .

  Further, in the detection method described above, a touch detection signal is detected between the segment electrodes, so that the touch position can be detected only in the X direction shown in FIG. Therefore, the touch position in the Y direction can be detected by changing the vertical positional relationship between the segment electrode 15 and the common electrode 13.

  Furthermore, if the touch position is detected by both the segment electrode 15 and the common electrode 13, the touch position can be detected in both the X and Y directions.

  However, in the structure shown in FIG. 1, when the touch position in the X direction is detected by the segment electrode 15 and the Y position is detected by the common electrode 13, the distance between the common electrode 13 and the finger 24 is the distance between the segment electrode 15 and the finger 24. Longer than the distance. For this reason, since the level of the touch signal at the common electrode 13 is smaller than the level of the touch signal at the segment electrode 15, sensitivity adjustment and noise countermeasures can be performed as necessary to perform position detection.

  In the example shown in FIG. 2, the touch detection method in the STN liquid crystal display device (Super-twisted nematic display) has been described. However, the touch detection method of the present invention is a TFT (Thin Film) composed of a source electrode and a gate. Transistor) liquid crystal display devices can also be applied. That is, the touch position can be detected by applying the touch detection signal and detecting the touch signal between the source electrodes of the TFT liquid crystal display device.

[Description of circuit configuration of liquid crystal display device with integrated touch panel]
(First circuit configuration example)
Next, a circuit configuration example of the touch panel integrated liquid crystal display device of the present invention will be described.
FIG. 3 is a diagram showing a first circuit configuration example of the touch panel integrated liquid crystal display device of the present invention, and shows a part directly related to the present invention.

  As shown in FIG. 3, in the touch panel integrated liquid crystal display device of the present invention, an LCD (liquid crystal) drive unit 40, a touch detection signal output unit 50, a touch signal detection unit 60, a control unit 31, and a control unit 31. And an internal touch position determination unit 32. The LCD drive unit 40, the touch detection signal output unit 50, and the touch signal detection unit 60 are provided in the driver IC 21 shown in FIG.

  The control unit 31 includes a CPU (Central Processing Unit) and the like, and controls the operations of the LCD drive unit 40, the touch detection signal output unit 50, and the touch signal detection unit 60 to perform touch position detection processing.

  The LCD drive unit 40 includes a plurality of output buffer circuits 41 corresponding to the electrodes of the segment electrode 15. The output side of the output buffer circuit 41 is connected to the electrode terminal portion 19 of the segment electrode 15 via a corresponding switch in the switch block S1. The output buffer circuit 41 is a circuit for applying a liquid crystal driving voltage to the segment electrode 15. The switches in the switch block S1 are turned on as a whole when the liquid crystal display device performs display, and are turned off as a whole when display is not performed in the liquid crystal display device.

  The touch detection signal output unit 50 includes a plurality of output buffer circuits 51 corresponding to the electrodes of the segment electrode 15. The output side of the output buffer circuit 51 is connected to the electrode terminal portion 19 of the segment electrode 15 through a corresponding switch in the switch block S2. The output buffer circuit 51 outputs a touch detection signal (for example, a high-frequency signal having a predetermined frequency) applied to the segment electrode 15. By turning on the switch of the switch block S2, a touch detection signal is applied to the segment electrode connected to the switch.

  The touch signal detection unit 60 includes a plurality of input buffer circuits 61 corresponding to the electrodes of the segment electrode 15. The input side of the input buffer circuit 61 in the touch signal detection unit 60 is connected to the electrode terminal unit 19 of the segment electrode 15 via a corresponding switch in the switch block S3. The switch block S3 is an ON / OFF switch for inputting a touch signal from the selected segment electrode 15 to the input buffer circuit 61. Further, the touch signal detection unit 60 transmits the detected touch signal to the touch position determination unit 32, and the touch position determination unit 32 uses a touch signal detected by the touch signal detection unit 60 as a human finger or the like. The touch position is determined.

  Note that the switch blocks S1, S2, and S3 are indicated by mechanical switch symbols for easy understanding of the circuit operation, but actually, the switch function can be realized by an analog switch or the like. Further, as shown in an example described later, the switch itself may be omitted.

  In the above configuration, when the switches in the switch block S1 connected to the LCD driving unit 40 are alternately turned ON and OFF (ON and OFF as a whole switch), and the liquid crystal display driving and the touch position detection are intermittently performed. An example will be described.

  When the liquid crystal display drive is intermittently performed, all the switches in the switch block S1 are turned off, and the touch position is detected during the position detection period in which the liquid crystal display drive is not performed. In this case, the touch detection signal is applied to the segment electrode 15 by selecting and turning on the switch in the switch block S2. And the touch signal output from the segment electrode 15 to which the touch detection signal is not applied is detected by selecting the switch in the switch block S3 and turning it ON.

  For example, as shown in FIG. 4A, during the period when the switch in the switch block S1 is OFF (position detection period), the switch S2a in the switch block S2 is turned ON and the touch detection signal is applied to the segment electrode SEG3. To do. In addition, the switches S3a and S3c (switches adjacent to the switch S3b connected to the switch S2a) in the switch block S3 are turned on, and the other switches are turned off. As a result, when a finger touches the portion of the display screen on which the segment electrodes SEG2, SEG3, and SEG4 are arranged, the touch signal can be detected via S3a and S3c.

  FIG. 4B schematically shows the signal voltage waveform applied to the segment electrode SEG3 of the circuit shown in FIG. As shown in the figure, the liquid crystal drive voltage Ve is applied in the LCD display section Tdsp, and the touch detection signal St output from the touch detection signal output unit 50 is applied in the position detection period Tdet.

  FIG. 5 more specifically shows signal voltage waveforms applied to the segment electrode 15 and the common electrode 13. FIG. 5A shows the waveform of the liquid crystal drive voltage at the normal time, and FIG. 5B shows the waveform of the liquid crystal drive voltage at the time of touch position detection.

  As shown in FIG. 5A, in the case of normal liquid crystal driving, the liquid crystal driving voltage applied to the segment electrodes SEG1 to SEG5 and the common electrodes COM1 to COM4 is repeated in units of one frame (period T1f).

  Further, as shown in FIG. 5B, when the touch position is detected, the segment electrodes SEG1 to SEG5 and the common electrodes COM1 to COM4 are touched on the liquid crystal display section Tdsp in which the liquid crystal driving voltage is applied and the segment electrodes SEG1 to SEG5. The position detection period Tdet to which the detection signal a is applied is alternately repeated. In the position detection period Tdet, the common electrodes COM1 to COM4 side is a signal indefinite period Tus in which no signal is applied.

  In the position detection period Tdet, the application of the liquid crystal driving voltage output from the LCD driving unit 40 to the segment electrodes SEG1 to SEG5 is stopped, and the touch detection signal a is sequentially applied to the segment electrodes SEG1 to SEG5. That is, the touch signal is detected while sequentially applying the touch detection signal a to the segment electrodes SEG1 to SEG5.

  When the touch detection signal a is applied to the SEG 4 and a finger is touched on or near the portion of the display screen on which the SEG 4 is arranged, the touch signal b is generated on the adjacent segment electrode SEG 5 via the finger. Thereby, it is possible to detect that a finger is touched on or near the top of the SEG 4.

  Although the first circuit configuration example of the touch panel integrated liquid crystal display device of the present invention has been described above, there are various methods for the switch block S2 and the switch selection and input order methods (scan methods) in the switch block S3. Can be used.

  For example, the switches in the switch block S2 are turned ON in order from the top, and in the switch block S3, the switch in S3 connected to the switch turned ON in S2 is turned OFF and is adjacent to the switch turned OFF. Turn on the switch or nearby switch.

  Further, the distance between the segment electrodes 15 (for example, several 100 μm) is significantly smaller than the size of the finger. For this reason, one segment electrode may be selected for each of the plurality of segment electrodes, and a touch detection signal may be applied to the selected segment electrode. The touch signal is detected from the segment electrode adjacent to the segment electrode to which the touch detection signal is applied or the segment electrode located in the vicinity.

  In addition, as shown in FIG. 6, the switches in a predetermined number of groups such as turning on the two switches S2a and S2b in the switch block S2 and turning on the two switches S3a and S3b in the switch block S3. May be turned on and off.

(Second circuit configuration example)
FIG. 7 is a diagram showing a second circuit configuration example of the touch panel integrated liquid crystal display device of the present invention. The touch panel integrated liquid crystal display device shown in FIG. 7 is an example in which the switch block S3 is omitted in the first circuit configuration shown in FIG. 3, and the other configurations are the same. For this reason, the same code | symbol is attached | subjected to the same component and the overlapping description is abbreviate | omitted.

  In the circuit configuration shown in FIG. 7, since there is no switch block S3, the touch detection signal output from the switch block S2 is directly input to the touch signal detection unit 60. For this reason, the touch signal detection unit 60 ignores the touch signals detected from the segment electrode SEG3 connected to the switch S2a (ON switch) of the switch block S2 among the touch signals detected by the segment electrode 15. To work.

  This is because it is known in advance that the switch S2a in the switch block S2 is ON on the control unit 31 side, and the touch position determination unit 32 outputs the touch signal detected from the segment electrode SEG3 based on this information. Exclude the touch position determination.

  In the configuration example shown in FIG. 7, the switch block S3 can be omitted, and the hardware configuration can be simplified accordingly.

(Third circuit configuration example)
FIG. 8 is a diagram showing a third circuit configuration example of the touch panel integrated liquid crystal display device of the present invention. The touch panel integrated liquid crystal display device shown in FIG. 8 is an example in which the switch block S1 is omitted from the first circuit configuration shown in FIG. 3, and the other configurations are the same. For this reason, the same code | symbol is attached | subjected to the same component and the overlapping description is abbreviate | omitted.

  In the circuit configuration shown in FIG. 8, since there is no switch block S1, a liquid crystal driving voltage is always applied to each segment electrode 15.

  Further, since the switch S2a in the switch block S2 is ON, the liquid crystal drive voltage output from the LCD drive unit 40 and the touch detection signal output from the touch signal detection unit 60 are simultaneously applied to the segment electrode SEG3. Will be applied.

  For example, FIG. 9 is a diagram schematically showing a touch detection signal applied to the segment electrode SEG3. As shown in the figure, in the position detection period Tdet, the signal is superimposed on the liquid crystal drive voltage Ve. A touch detection signal St is applied.

  In the configuration example shown in FIG. 8, the switch block S1 can be omitted, and the hardware configuration can be simplified accordingly.

[Example of equipment using the touch panel integrated liquid crystal display device of the present invention]
Next, an example of a device using the touch panel integrated liquid crystal display device of the present invention will be described.

  FIG. 10 is a diagram illustrating an example of a portable terminal including the touch panel integrated liquid crystal display device of the present invention. For example, a mobile phone or a PDA.

  A mobile terminal 71 shown in FIG. 10A has push button display portions 73, 74, 75, and 76 arranged in the X direction on the liquid crystal display screen 72 (the arrangement direction of the segment electrodes shown in FIG. 1). . When a desired push button of the push button display units 73, 74, 75, and 76 is touched with a finger, the touched push button position is determined by the finger position detected by the segment electrode and the coordinates of the corresponding button. From this, it is determined which button has been pressed.

  Thereby, the touched button can be identified and processing corresponding to the button can be performed.

  A mobile terminal 81 shown in FIG. 10B has a volume adjustment volume display section 83 for adjusting the volume in the X direction (the cement electrode arrangement direction shown in FIG. 1) on the liquid crystal display screen 82. is there. By touching a desired position (position in the X direction) of the volume adjustment volume display unit 83 with a finger, the touched position can be detected by the segment electrode.

  As a result, the touched position on the volume adjustment volume display unit 83 can be detected to adjust the volume.

  Thus, by using the touch panel integrated liquid crystal display device of the present invention for a mobile terminal, the mobile terminal can be made thinner and lighter.

  Although the embodiments of the present invention have been described above, the touch panel integrated liquid crystal display device of the present invention is not limited to the above illustrated examples, and various modifications can be made without departing from the gist of the present invention. Can be added.

It is a figure which shows the structure of the liquid crystal display device integrated with a touch panel concerning embodiment of this invention. It is a figure for demonstrating the touch position detection principle in the touchscreen integrated liquid crystal display device of this invention. It is a figure which shows the 1st circuit structural example of the touchscreen integrated liquid crystal display device of this invention. FIG. 4 is a diagram showing a first example of a switch-on operation in the circuit shown in FIG. 3. It is the figure which showed more concretely the signal waveform applied to a segment electrode and a common electrode. It is a figure which shows the 2nd example of the switch activation operation | movement in the circuit shown in FIG. It is a figure which shows the 2nd circuit structural example of the touchscreen integrated liquid crystal display device of this invention. It is a figure which shows the 3rd circuit structural example of the touchscreen integrated liquid crystal display device of this invention. It is a figure which shows the voltage waveform applied to the segment electrode in the circuit shown in FIG. It is a figure which shows the example of the portable terminal which uses the touchscreen integrated liquid crystal display device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Lower light-shielding plate, 12 ... B glass, 13 ... Lower transparent electrode (common electrode), 14 ... Liquid crystal phase, 15 ... Upper transparent electrode (segment electrode), 16 ... A glass, 17 ... upper light shielding plate, 18 ... sealant, 19 ... electrode terminal portion, 21 ... driver IC, 22 ... common wiring, 23 ... segment wiring, 24 ..Human finger, 31... Control unit, 32... Touch position determination unit, 40... LCD drive unit, 41... Output buffer circuit, 50. ... Output buffer circuit, 60 ... Touch signal detector, 61 ... Input buffer circuit, 71 ... Portable terminal, 73 ... Liquid crystal display screen, 73, 74, 75, 76 ... Button Display unit, 81 ... mobile terminal, 82 ... liquid crystal display screen, 83 ... sound Adjust the volume display unit

Claims (13)

A touch panel integrated liquid crystal display device in which a touch panel function is added to a liquid crystal display device that displays and drives the liquid crystal phase by a plurality of planar electrodes arranged in parallel on the surface of the liquid crystal phase,
When an object such as a dielectric or conductor including a human finger touches the display screen of the liquid crystal display device,
It is configured to detect a touch position by detecting a change in capacitance between the planar electrodes at a position corresponding to a portion of the display screen touched by the object,
A liquid crystal display device integrated with a touch panel. The liquid crystal display device is composed of an STN liquid crystal display device,
A plurality of transparent electrodes serving as segment electrodes are arranged on the surface of the liquid crystal phase,
When the object touches the display screen of the liquid crystal display device, the touch position is detected by detecting a change in capacitance between the segment electrodes corresponding to the position touched by the object. Has been done,
The touch panel integrated liquid crystal display device according to claim 1. A plurality of transparent electrodes serving as segment electrodes are arranged on one surface side of the liquid crystal phase, and a plurality of transparent electrodes serving as common electrodes are arranged on the other surface side in a direction perpendicular to the segment electrodes. Has been done,
The touch panel integrated liquid crystal display device according to claim 2. An LCD driving unit for applying a liquid crystal driving voltage for displaying and driving a liquid crystal phase to each of the segment electrodes;
A touch detection signal output unit that selects one or a plurality of segment electrodes from each of the segment electrodes and applies a touch detection signal for detecting a touch position of the object;
A touch signal detection unit that selects one or a plurality of segment electrodes from each of the segment electrodes and detects the touch detection signal as a touch signal via the touched object;
A touch position determination unit that determines a touch position of the object based on the touch signal detected by the touch signal detection unit;
The touch panel integrated liquid crystal display device according to claim 2, wherein the touch panel integrated liquid crystal display device is provided. An LCD display period in which a liquid crystal driving voltage is applied to the segment electrodes from the LCD driving unit and a position detection period in which the application of the liquid crystal driving voltage is stopped are alternately provided
During the position detection period,
The touch detection signal output unit selects one or a plurality of segment electrodes from the segment electrodes, and applies a touch detection signal for detecting the touch position of the object,
The touch signal detection unit receives the touch detection signal from one or a plurality of segment electrodes located adjacent to or near the segment electrode selected by the touch detection signal output unit via the touched object. To detect as a touch signal,
The touch panel integrated liquid crystal display device according to claim 4, which is configured. While constantly applying a liquid crystal driving voltage to the segment electrode from the LCD driving unit,
The touch detection signal output unit selects one or a plurality of segment electrodes from each of the segment electrodes, and applies a touch detection signal for detecting the touch position of the object superimposed on the liquid crystal driving voltage,
The touch signal detection unit receives the touch detection signal from one or a plurality of segment electrodes located adjacent to or near the segment electrode selected by the touch detection signal output unit via the touched object. To detect as a touch signal,
The touch panel integrated liquid crystal display device according to claim 4, which is configured. The touch signal detection unit is configured to detect a touch signal from all the electrodes of the segment electrode,
The touch position determination unit is configured to determine a touch position based on a touch signal detected by other segment electrodes excluding the segment electrode to which the touch detection signal is applied;
The touch panel integrated liquid crystal display device according to claim 5, wherein: In place of the segment electrode, detecting the touch position by the common electrode,
8. The touch panel integrated liquid crystal display device according to claim 3, wherein the touch panel integrated liquid crystal display device is provided. The liquid crystal display device comprises a TFT liquid crystal display device,
Instead of the segment electrode, it was configured using the source line of the TFT liquid crystal display device,
8. A touch panel integrated liquid crystal display device according to claim 4, wherein the liquid crystal display device is a touch panel integrated liquid crystal display device. A touch detection method in a touch panel integrated liquid crystal display device in which a touch panel function is added to a liquid crystal display device that displays and drives the liquid crystal phase by a plurality of planar electrodes arranged in parallel on the surface of the liquid crystal phase,
When an object such as a dielectric or conductor including a human finger touches the display screen of the liquid crystal display device,
Detecting a touch position by detecting a change in capacitance between the planar electrodes at a position corresponding to a portion of the display screen touched by the object;
A touch detection method characterized by the above. A STN liquid crystal display device in which a plurality of transparent electrodes serving as segment electrodes are arranged on one surface side of the liquid crystal phase, and a plurality of transparent electrodes serving as common electrodes are arranged on the other surface side in a direction perpendicular to the segment electrodes. And use
Detecting the touch position by detecting a change in capacitance between the segment electrodes corresponding to the position touched by the object when the object touches the display screen of the liquid crystal display device;
The touch detection method according to claim 10. LCD driving procedure for applying a liquid crystal driving voltage for displaying and driving a liquid crystal phase to each segment electrode;
A touch detection signal output procedure for selecting one or a plurality of segment electrodes from each of the segment electrodes and applying a touch detection signal for detecting a touch position of the object;
A touch signal detection procedure for selecting one or a plurality of segment electrodes from each of the segment electrodes and detecting the touch detection signal as a touch signal via the touched object;
A touch position determination procedure for determining a touch position of the object based on the touch signal detected by the touch signal detection procedure;
The touch detection method according to claim 11, further comprising:   A portable terminal comprising the touch panel integrated liquid crystal display device according to any one of claims 1 to 9.

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