JP2008097051A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase position detecting precision, and to suppress the deterioration of display quality, and to reduce a frame region. <P>SOLUTION: A plurality of counter electrodes 35 are longitudinally formed so as to be extended along a signal line 27, and provided with a terminal section formed on an active matrix substrate 21, and electrically connected via a transfer part 37 to a plurality of counter electrodes 35; an input means 41 connected via a switch part 50 to the terminal section for inputting a predetermined signal to the counter electrode 35; and a detection means 42 electrically connected to the terminal section for receiving a signal from the counter electrode 35 showing the position of a contact object. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a display device, and more particularly to a touch panel display device.

  In recent years, display devices (touch panel display devices) equipped with a touch panel for detecting a contact position have been widely used (see, for example, Patent Documents 1 and 2).

  The touch panel is classified into a resistance film method, a capacitance method (for example, Patent Document 2), an infrared method, an ultrasonic method, an electromagnetic induction method, and the like according to the operation principle. Among them, a capacitive touch panel is known to be suitable for a display device because it is relatively difficult to impair the optical characteristics of the display device.

  In general, a capacitive touch panel has a transparent electrode for position detection provided so as to cover the display panel, a plurality of electrode terminals provided at a peripheral portion of the transparent electrode for position detection, and a current flowing through the electrode terminal. And a current detection circuit for detecting. When the touch panel is touched, the transparent electrode for position detection is grounded through the electrostatic capacitance of an insulator interposed between the transparent electrode for position detection and the human body at the touched point. Since a change occurs in the resistance value between each current terminal and the ground point depending on the touched position, the touched position is detected by detecting this change by the current detection circuit. .

  In recent years, there has been a strong demand for thin and light-weight display devices in general including touch panel display devices. Generally, a touch panel is installed on a conventional display panel so as to additionally cover the display panel. Therefore, an increase in thickness is unavoidable as compared with a display panel without a touch panel. On the other hand, as a technique for meeting the demand for reduction in thickness and weight, it has been proposed to share an electrode originally provided on a display panel as a position detection electrode of a touch panel.

For example, in the case of an active matrix liquid crystal display device, a counter electrode is generally provided on the counter substrate side so as to cover all the pixel electrodes with respect to an active matrix substrate having a plurality of pixel electrodes, and between the pixel electrodes and the counter electrodes. Display is performed by driving the liquid crystal intervening, and a configuration in which this counter electrode also serves as a position detection electrode is conceivable. That is, as in a normal liquid crystal display device, a driving voltage necessary for display is supplied to the counter electrode, and a signal for detecting the touch position is applied to the counter electrode in a period that does not contribute to display, such as a vertical blanking period. And a current from the counter electrode is detected to detect the touch position.
JP-A-61-174587 JP 2003-66417 A

  However, since the counter electrode that contributes to display is provided inside the counter substrate, when detecting the touch position, between the contact body that contacts the outside of the counter substrate and the counter electrode inside the counter substrate. The electrostatic capacitance formed in is detected. Usually, since the thickness of the substrate is relatively large, the detected capacitance is extremely small, and the detection signal tends to be weak. That is, there is a problem that it is difficult to obtain sufficiently high position detection accuracy even if the counter electrode originally provided on the display panel is used as the position detection electrode of the capacitive touch panel.

  Furthermore, there is a strong demand to make the frame area that is provided around the display area and does not contribute to the display as narrow as possible while providing the function of the touch panel.

  The present invention has been made in view of such various points, and an object of the present invention is to improve the position detection accuracy as much as possible and improve the display quality of a display device that also serves as a position detection electrode. The purpose is to suppress the decrease and to reduce the frame area.

  As a result of extensive research, the present inventor has found it difficult to achieve both good display quality and high-accuracy position detection when the counter electrode in the conventional display panel is also used as the position detection electrode of the touch panel. As a result, the present invention has been made.

  Hereinafter, the reason why it is difficult to achieve both good display quality and highly accurate position detection, which has been elucidated by the present inventors, will be described in detail.

  Originally, when trying to drive each pixel of a liquid crystal display device, a voltage corresponding to an image signal is written from the signal line to the pixel electrode via the active element, thereby generating a potential difference between the pixel electrode and the counter electrode. Generate and display. While a specific reference potential is supplied to the counter electrode, the potential state of each pixel is generally changed according to the value of the voltage applied to the pixel electrode.

  This reference potential may be a direct current or ground potential, or may be an alternating current to reduce the signal level of the signal line, but in any case, a stable potential is maintained as the reference potential for the entire screen. It is required to do. Therefore, it is necessary to avoid the generation of ripples and noise at the moment of writing to multiple pixels or the moment of polarity reversal of the signal line. Reduce the impedance of the input section or reduce the resistance of the counter electrode itself. Nervous is used.

  If the counter electrode is not sufficiently low in resistance, even if alternating current is applied to the counter electrode, the signal delay is large and the function as the predetermined reference potential is not sufficiently performed. As a result, the voltage charging to the pixel electrode may be hindered, resulting in insufficient charging, leading to a decrease in contrast and unevenness. In addition, at the moment when voltage is written to the pixel column corresponding to a certain scanning line, when ripples appear on the potential of the counter electrode due to the influence of the writing load at a specific location, writing to the left and right pixels of the signal line is performed. Since this is performed under an unstable reference potential, desired charging is not performed. As a result, the display may be in a defective state with its tail on the left and right, and so-called crosstalk may occur.

  On the other hand, the position detection electrode of the touch panel is required to have a high resistance, contrary to the case of the counter electrode for display. This is because the touch position is detected based on the difference in resistance from the plurality of input / output terminals of the position detection electrode to the touch position, and if the resistance of the position detection electrode is low, This is because the influence of the parasitic resistance of the peripheral circuit becomes relatively large and the sensitivity of the position information is lowered.

  That is, it is preferable that the resistance value between the touch position and the input / output unit is several tens to several hundreds times that of the peripheral circuit. This is contrary to the low resistance characteristic required from the viewpoint of the display quality.

  In order to achieve the above object, in the present invention, a plurality of opposing electrodes are formed in a long shape so as to extend along the signal line, and a terminal portion electrically connected to the opposing electrode via a transition portion Are formed on an active matrix substrate.

  Specifically, the display device according to the present invention includes an active matrix substrate having a plurality of scanning lines, a plurality of signal lines, a plurality of pixel electrodes, and a switching element electrically connected to the plurality of pixel electrodes, A counter substrate disposed opposite to the active matrix substrate and having a counter electrode facing the pixel electrode; and a display medium layer provided between the pixel electrode and the counter electrode for controlling display. A display device configured to detect a position of the contact body by detecting a capacitance formed between the contact body in contact with the counter substrate and a part of the counter electrode; The counter electrodes are formed in a plurality of elongated shapes so as to extend along the signal lines, are formed on the active matrix substrate, and are electrically connected to the plurality of counter electrodes via a transition portion. A terminal unit that is connected to the terminal unit via a switch unit, an input unit that inputs a predetermined signal to the counter electrode, and an electrical connection unit that is electrically connected to the terminal unit and indicates the position of the contact body. Detecting means for receiving a signal from the counter electrode.

  According to this configuration, since the counter electrode is formed in an elongated pattern having a long distance and a narrow width along the signal line, even if the surface resistance of the counter electrode is not high resistance but relatively low The resistance between both ends in the direction along the signal line of the counter electrode (hereinafter also referred to as the signal line direction) can be increased. As a result, the accuracy of detection of the contact position of the detected contact body is significantly improved in the signal line direction.

  Further, since it is not necessary to increase the surface resistance of the counter electrode, there is no deterioration in display quality due to a decrease in contrast or display unevenness. That is, since the counter electrode is patterned in a long shape in the signal line direction, not in the scan line direction, when a certain scan line is selectively written, each long counter electrode has, for example, one pixel. Only write load is applied. Therefore, the load applied to all the long counter electrodes can be made uniform, so that the magnitude of the load at any point can be maintained at the same level as that of a normal planar counter electrode. Does not occur.

  In addition, since each counter electrode extends in the signal line direction but is separated from each other in the scanning line direction, even if ripples are applied to the counter electrode, the counter electrode does not propagate in the scanning line direction, and the crossing due to the above-described load during writing is performed. Talk is suppressed.

  Furthermore, when the switch unit is in an on state, a predetermined signal such as a display signal is input from the input unit to the plurality of counter electrodes via the terminal unit and the transfer unit formed on the active matrix substrate. On the other hand, a signal indicating the position of the contact body is output from the plurality of counter electrodes to the detecting means via the transition portion and the terminal portion formed on the active matrix substrate. That is, a signal input / output to / from the counter electrode can be transmitted / received not to the counter substrate side but to the active matrix substrate side.

  Therefore, since the input means and the detection means can be formed on the active matrix substrate, it is not necessary to newly provide a space for arranging these detection means and the like on the counter substrate. As a result, it is possible to suppress an increase in the frame area due to the enlargement of the counter substrate. Further, since the input means and the detection means are not provided on the counter substrate side, the complexity of the mounting process is avoided, and an increase in manufacturing cost is suppressed.

  A plurality of the terminal portions may be formed corresponding to the plurality of counter electrodes, and may be short-circuited to each other by a first short-circuit wiring formed on the active matrix substrate.

  According to this configuration, since the plurality of terminal portions are short-circuited by the first short-circuit wiring, a signal indicating the position of the contact body can be read from both end sides of the first short-circuit wiring. Thus, not only the signal line direction but also the contact position information in the scanning signal direction can be detected.

  A plurality of the terminal portions may be formed corresponding to the plurality of counter electrodes, and each of the terminal portions may be connected to the corresponding counter electrode via the transition portion.

  According to this configuration, signals are input / output between each counter substrate and the corresponding terminal portion via the transition portion.

  The input means includes a selection signal supply unit that supplies a selection signal for switching control of the switch unit to the switch unit, and a display signal supply unit that supplies a display signal to the counter electrode, A plurality of switch units may be provided corresponding to the plurality of terminal units, and one end thereof may be connected to the corresponding terminal unit, while the other end may be connected to the display signal supply unit.

  According to this configuration, the switch unit is switched to the on state or the off state by receiving the selection signal sent from the selection signal supply unit. Thus, when the switch unit is in the ON state, a display signal is input from the display signal supply unit to the counter electrode.

  The input means includes a selection signal supply unit that supplies a selection signal for switching control of the switch unit to the switch unit, and a display signal supply unit that supplies a display signal to the counter electrode, The switch unit may have one end connected to the first short-circuit wiring and the other end connected to the display signal supply unit.

  With this configuration, the display signal is input from the display signal supply unit to each counter electrode via the first short-circuit wiring, each terminal unit, and each transition unit when the switch unit is in the ON state. On the other hand, a signal indicating the contact position is output from the counter electrode to the detection means via the transition portion, the terminal portion, and the first short-circuit wiring.

  In addition, since the number of switch portions can be suppressed to a necessary and sufficient number, it is possible to reduce the formation region of the switch portions and further reduce the frame region. Furthermore, since the number of switch units can be reduced, a decrease in yield due to a failure of the switch unit itself can be suppressed.

  The other end of the switch unit is connected to the display signal supply unit via a common line, and a resistance value between both ends of the common line is lower than a resistance value between both ends of the first short-circuit line. preferable.

  By the way, the wiring for short-circuiting the terminal portions is preferable in that the higher the resistance, the higher the position detection accuracy in the scanning line direction, but when the display signal is transmitted, the display quality is improved as described above. High resistance is not desirable. According to the above configuration, by switching the switch unit, the display signal is input to the counter electrode via the common wiring having a relatively low resistance value, while the signal indicating the contact position has a relatively high resistance value. Output from the counter electrode via the first short-circuit wiring. That is, it is possible to achieve both good display quality and highly accurate contact position detection.

  The plurality of counter electrodes may be short-circuited to each other by a second short-circuit wiring formed on the counter substrate.

  According to this configuration, the number of transition portions can be reduced by forming transition portions in the second short-circuit wiring. Therefore, it is possible to reduce the frame area by reducing the area required to form a large number of transition portions. In addition, since it is not necessary to provide a wiring for short-circuiting the terminal portions on the active matrix substrate, this also reduces the frame area. Moreover, by providing a larger number of transition portions than necessary, it is possible to maintain the conduction state between the terminal portion and the counter electrode even if some transition portions are defective. And lead to improved yield.

  Furthermore, the input means includes a selection signal supply unit that supplies a selection signal for switching control of the switch unit to the switch unit, and a display signal supply unit that supplies a display signal to the counter electrode. The terminal portion includes a first terminal portion disposed opposite to both end portions of the second short-circuit wiring, and a second terminal portion disposed opposite to the intermediate portion of the second short-circuit wiring or the counter electrode. The transition portion connects the first transition portion that connects the first terminal portion and the second short-circuit wiring, and connects the second terminal portion and the second short-circuit wiring or the counter electrode. The switch section may include one end connected to the second terminal section, and the other end connected to the display signal supply section.

  With this configuration, the display signal is input from the display signal supply unit to each counter electrode via the second terminal unit, the second transition unit, and the second short-circuit wiring when the switch unit is in the ON state. The On the other hand, a signal indicating the contact position is output from the counter electrode to the detection means via the second short-circuit wiring, the first transition portion, and the first terminal portion.

  The counter electrode and the second short-circuit wiring are preferably formed integrally with a transparent conductive film.

  With this configuration, it is possible to obtain a high-resistance short-circuit wiring necessary for increasing the detection accuracy of the contact position using the electrode material of the counter substrate.

  The display medium layer is preferably a liquid crystal layer.

  That is, in an active matrix liquid crystal display device, a transparent conductive oxide film is often applied as a counter electrode to a counter substrate facing the active matrix substrate, and the position detection accuracy is also displayed by patterning the counter electrode. A display device with excellent quality can be easily obtained. Moreover, there is no increase in the process required for forming the second short-circuit wiring.

  According to the present invention, a plurality of counter electrodes are formed in a long shape so as to extend along the signal line, and a terminal portion electrically connected to the counter electrode via a transition portion is formed on the active matrix substrate. As a result, the position detection accuracy can be increased, the display quality can be prevented from being lowered, and the frame area can be further reduced.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiment.

Embodiment 1 of the Invention
1 to 3 and FIG. 6 show Embodiment 1 of the present invention. FIG. 1 is a plan view showing a main part of a liquid crystal display device 1 which is an embodiment of a display device according to the present invention. FIG. 2 is an enlarged plan view showing a part of the active matrix substrate 21. FIG. 3 is a cross-sectional view schematically showing the structure of the liquid crystal display device 1. FIG. 6 is a cross-sectional view schematically showing a cross-section of the main part of the liquid crystal display device 1.

  As shown in FIG. 3, the liquid crystal display device 1 includes an active matrix substrate 21, a counter substrate 22, and a liquid crystal layer 23 that is a display medium layer provided between the active matrix substrate 21 and the counter substrate 22. It has a so-called touch panel function.

  As shown in FIG. 2, a plurality of scanning lines 26, a plurality of signal lines 27, a plurality of pixel electrodes 29, and a plurality of switching elements TFTs (thin film transistors) 30 are formed on one surface of the active matrix substrate 21. Has been.

  The active matrix substrate 21 has a rectangular glass substrate 25, and the plurality of scanning lines 26 are formed so as to extend in parallel with each other on one surface (surface on the liquid crystal layer 23 side) of the glass substrate 25. . On the other hand, the plurality of signal lines 27 extend in parallel with each other on one surface of the glass substrate 25 so as to extend perpendicular to the scanning lines 26. Each rectangular area surrounded by the scanning lines 26 and the signal lines 27 constitutes a pixel 28. That is, the pixels 28 are arranged in a matrix. Each pixel 28 is provided with a pixel electrode 29 for driving and controlling the liquid crystal layer 23 for each pixel 28.

  Further, a TFT 30 is formed in each pixel 28 and is electrically connected to the pixel electrode 29. Although not shown, the scanning line 26 is connected to the gate electrode of the TFT 30, while the signal line 27 is connected to the source electrode of the TFT 30. A polarizing plate 31 is laminated on the other surface of the glass substrate 25 (the surface opposite to the liquid crystal layer 23).

  The counter substrate 22 is disposed to face one surface of the active matrix substrate 21. The counter substrate 22 has a rectangular glass substrate 33, and a color filter 32 is formed on one surface (surface on the liquid crystal layer 23 side) of the glass substrate 33, and the counter electrode covers the color filter 32. 35 is formed. The counter electrode 35 is disposed so as to face the pixel electrode 29. On the other hand, a polarizing plate 36 whose absorption axis is substantially orthogonal to the polarizing plate 31 is formed on the other surface of the glass substrate 33 (the surface opposite to the liquid crystal layer 23).

  As shown in FIG. 1, the active matrix substrate 21 has a region in which one side extends outward from the side end portion of the counter substrate 22 when viewed from the direction perpendicular to the substrate. This is a mounting area 34 in which an IC driver (not shown) for driving is mounted. The IC driver includes an input circuit 41 and a detection circuit 42 which will be described later.

  The liquid crystal display device 1 detects the capacitance formed between the counter electrode 35 and the contact body 5 such as a user's fingertip or pen that is in contact with the counter substrate 22. The position (touch position) A is detected.

  That is, as shown in FIG. 3, when the contact body 5 comes into contact with the surface of the counter substrate 22 opposite to the surface on which the counter electrode 35 is formed (that is, the surface of the polarizing plate 36), An electrostatic capacity is formed between 5 and a part of the counter electrode 35. The contact position A of the contact body 5 is detected by detecting this capacitance. That is, each counter electrode 35 also serves as a position detection electrode that detects the contact position A of the contact body 5.

  The counter electrode 35 is formed of ITO, IZO, or the like, and a plurality of long patterns are formed so as to extend along the signal line 27 as shown in FIG. Each counter electrode 35 is disposed between the signal lines 27 and is formed to have, for example, substantially the same width as the pixel electrode 29. That is, the counter electrodes 35 are respectively arranged corresponding to the pixel electrode groups in one row connected to the signal lines 27 via the TFTs 30. In the present embodiment, counter electrodes 35 corresponding to the number of signal lines 27 are formed. Further, both end portions of the counter electrode 35 are input / output portions 38 through which signals are input / output.

  As shown in FIG. 1, a plurality of terminal portions 40 are formed on the active matrix substrate 21 so as to be opposed to the input / output portions 38 of the plurality of counter electrodes 35, as schematically shown in FIG. Has been. Between each terminal part 40 and the input-output part 38, the transfer part 37 which is a conductor is interposed. Accordingly, each terminal unit 40 is electrically connected to the corresponding input / output unit 38 via the transition unit 37.

  The transition portion 37 is made of, for example, gold particles mixed with a sealing material (not shown) that surrounds the periphery of the liquid crystal layer 23 and bonds the active matrix substrate 21 and the counter substrate 22. That is, a sealing material in which a predetermined amount of gold particles is mixed as the transition portion 37 is provided so as to overlap the terminal portion 40. By doing so, the input / output part 38 and the terminal part 40 are anisotropically connected so as not to short-circuit between the adjacent parts.

  In the active matrix substrate 21, first short-circuit wirings 52 extending in the direction intersecting the signal line direction (typically the scanning line direction) are formed in the vicinity of each terminal portion 40. And each terminal part 40 is mutually short-circuited by the 1st short circuit wiring 52 which is a high resistance wiring in the both ends side of the counter electrode 35. As shown in FIG. An end portion of the first short-circuit wiring 52 extends to the mounting region 34 and is connected to a detection circuit 42 described later.

  In addition, an input circuit 41 and a detection circuit 42 provided in the mounting region 34 of the active matrix substrate 21 are electrically connected to the counter electrode 35 so that a predetermined signal is input / output.

  The input circuit 41 is connected to the terminal unit 40 via the switch unit 50 and is configured to input a predetermined signal to the counter electrode 35. The input circuit 41 is connected to each switch unit 50, a selection signal supply unit 54 that supplies a selection signal for switching control of the switch unit 50 to the switch unit 50, and a display that supplies a display signal to the counter electrode 35. Signal supply unit 53. The detection circuit 42 is electrically connected to the terminal portion 40 and is configured to receive a signal (hereinafter also referred to as a position detection signal) from the counter electrode 35 indicating the position A of the contact body 5.

  In FIG. 1, the display signal supply unit 53, the selection signal supply unit 54, and the detection circuit 42 are illustrated outside the mounting region 34 for convenience of explanation. Has been placed. Further, although the detection circuit 42 and the display signal supply unit 53 are illustrated as being divided into two parts, in practice, it is also possible to form them together as one.

  A plurality of switch units 50 are provided corresponding to the plurality of terminal units 40, and one end is connected to the corresponding terminal unit 40, while the other end is connected to the display signal supply unit 53 via the common wiring 51. Has been. The common wiring 51 connects the other ends of the plurality of switch units 50, extends to the mounting region 34, and is connected to the display signal supply unit 53. Further, the common wiring 51 is formed of a metal wiring, and the resistance value between both ends of the common wiring 51 is lower than the resistance value between both ends of the first short-circuit wiring 52. Further, the resistance value between both ends of the first short-circuit wiring 52 in the signal line direction is defined to be 100Ω or more.

  The switch unit 50 is configured by a switching element such as a TFT, and is formed in the same process as the TFT 30 in each pixel 28. Therefore, it is not necessary to separately add a process for forming the switch unit 50, and the cost is not increased due to an increase in man-hours.

  The gates of the TFTs that are the switch portions 50 are connected to the selection control wiring 56 in common. An end portion of the selection control wiring 56 extends to the mounting region 34 and is connected to the selection signal supply unit 54. Thus, the switch units 50 are switched to the on or off state all at once.

  In this way, the selection signal output from the selection signal supply unit 54 is supplied to the switch unit 50 via the selection control wiring 56, whereby the switch unit 50 is controlled to be turned on and off, and the state in which the contact position A is detected and the display The state is switched to a state in which a signal is supplied to the counter electrode 35.

  In the display period during which the liquid crystal display device 1 performs display, a selection signal is input from the selection signal supply unit 54 to the switch unit 50 via the selection control wiring 56, and the switch unit 50 is switched to the on state. As a result, the display signal output from the display signal supply unit 53 passes through the common wiring 51, the switch unit 50, the terminal unit 40, the transition unit 37, and the input / output unit 38 with low impedance. Entered. As a result, a predetermined reference voltage is applied to each counter electrode 35 and display is performed.

  On the other hand, in a vertical blanking period that does not contribute to display, a selection signal is input from the selection signal supply unit 54 to the switch unit 50 via the selection control wiring 56, and the switch unit 50 is switched to an off state. As a result, no display signal is input to the counter electrode 35, and a position detection signal is output from the input / output unit 38 of the counter electrode 35, via the transition unit 37, the terminal unit 40, and the first short-circuit wiring 52. It is detected by the detection circuit 42. Thus, the contact position A is detected.

  Here, the operation principle of a so-called capacitive touch panel employed in the present invention will be described with reference to FIGS.

  FIG. 9 is a schematic plan view schematically showing the configuration of the basic capacitive touch panel 10. 10 is a cross-sectional view taken along line XX in FIG. FIG. 11 is a schematic plan view schematically showing a configuration in the vicinity of the position detection electrode 12.

  As shown in FIGS. 9 and 10, the capacitive touch panel 10 is made of, for example, glass or plastic, and is provided with a substrate body 11 having optical transparency and a planar shape on the substrate body 11 to transmit light. The position detecting electrode 12 having the characteristics and the insulating layer 18 provided on the position detecting electrode 12 are provided.

  A frame portion 17 is provided on the periphery of the position detection electrode 12. In each of the four corners of the frame portion 17, electrode terminals 14 (14 a, 14 b, 14 c, and 14 d) that are electrically connected to the position detection electrode 12 are provided. The electrode terminals 14a, 14b, 14c, and 14d are electrically connected to an AC power supply circuit, respectively, and are configured to be applied with a voltage of the same homologous potential. Each electrode terminal 14 is electrically connected to the current detection circuit 16 via the wiring 15.

  When the fingertip 5 or the like is not touching the capacitive touch panel 10, the same voltage is applied to the position detection electrode 12 from the electrode terminals 14a, 14b, 14c, and 14d connected to the power supply circuit. . For this reason, no current flows through the position detection electrode 12. On the other hand, when the position detection electrode 12 is touched by the fingertip 5 or the like via the surface of the capacitive touch panel 10, that is, the insulating layer 18 provided on the position detection electrode 12, the position detection electrode The twelve contact portions are capacitively coupled to the ground (ground plane) via a person. The electrical resistance between the capacitively coupled contact portion and the electrode terminal 14 electrically connected to the position detection electrode 12 is proportional to the distance between the contact portion and the electrode terminal 14.

  That is, a current proportional to each distance between the contact position A and the electrode terminals 14a, 14b, 14c, and 14d flows through the electrode terminals 14a, 14b, 14c, and 14d. For example, when the distance between the contact portion and the electrode terminal 14a is longer than the distance between the contact position A and the electrode terminal 14b, a larger current flows through the electrode terminal 14a than the electrode terminal 14b. Therefore, the position of the contact portion can be detected by detecting the magnitude of the current flowing through each of the electrode terminals 14a, 14b, 14c, and 14d by the current detection circuit 16.

  Next, the basic principle of the position detection method in the capacitive touch panel will be specifically described with reference to FIG. For convenience of explanation, a case where position detection on a line segment between the electrode terminal 14a and the electrode terminal 14b is performed will be described.

  FIG. 12 shows a circuit diagram including a one-dimensional resistor sandwiched between the electrode terminal 14a and the electrode terminal 14b.

  The electrode terminal 14a and the electrode terminal 14b are grounded via a current-voltage conversion resistor r and an AC power supply circuit 20, respectively. Each of the electrode terminals 14a and 14b is further connected to a current detection circuit.

  The power supply circuit 20 applies a voltage of the same homologous potential (AC e) between the electrode terminal 14a and the ground and between the electrode terminal 14b and the ground. In a state where the fingertip 5 or the like is not in contact with the touch panel, the electrode terminals 14a and 14b are at the same homologous potential, so that no current flows between the electrode terminal 14a and the electrode terminal 14b.

As shown in FIG. 12, for example, a case where the position X is touched with the fingertip 5 will be described. The resistance from the touched contact position A to the electrode terminals 14a and _{R 1} by fingertip 5, the resistance from the contact position A to the electrode terminals 14b and _{R 2,} the sum of _{R 1} and _{R 2} and R. Furthermore, the impedance of the human is Z, the current flowing through the electrode terminals 14a and i _1, when the current flowing through the electrode terminals 14b and i _2, the following formulas 1 and 2 are satisfied.

e = ri ₁ + R ₁ i ₁ + (i ₁ + i ₂ ) Z (Formula 1)
e = ri ₂ + R ₂ i ₂ + (i ₂ + i ₂ ) Z (Formula 2)
From the above formulas 1 and 2, the following formula 3 is obtained. Furthermore, the following formula 4 is obtained by modifying the following formula 3.

i ₁ (r + R ₁ ) = i ₂ (r + R ₂ ) (Formula 3)
i ₂ = i ₁ (r + R ₁ ) / (r + R ₂ ) (Formula 4)
Substituting Equation 4 into Equation 1 yields Equation 5 below.

e = ri ₁ + R ₁ i ₁ + (i ₁ + i ₁ (r + R ₁ ) / (r + R ₂ )) Z
= I ₁ (R (Z + r) + R ₁ R ₂ + 2Zr + r ² ) / (r + R ₂ ) (Formula 5)
From the above equation 5, the following equations 6 and 7 are obtained.

i ₁ = e (r + R ₂ ) / (R (Z + r) + R ₁ R ₂ + 2Zr + r ² ) (Formula 6)
i ₂ = e (r + R ₁ ) / (R (Z + r) + R ₁ R ₂ + 2Zr + r ² ) (Formula 7)
Here, when the ratio of the resistance R ₁ and the resistance R ₂ is expressed using the entire resistance R, the following formula 8 is obtained.

R ₁ / R = (2r / R + 1) i ₂ / (i ₁ + i ₂ ) −r / R (Formula 8)
Since the resistance r and the resistance R are known, the current i ₁ flowing through the electrode terminal 14a and the current i ₂ flowing through the electrode terminal 14b are detected by the current detection circuit, thereby calculating R ₁ / R based on Expression 8. can do. Note that R ₁ / R does not depend on the impedance Z including the person touching with the fingertip 5. Therefore, as long as the impedance Z is not zero or infinite, the above equation 8 is established, and changes, states, and the like due to people and materials can be ignored.

  By the way, it is preferable that the resistance R is large from the viewpoint of realizing high position detection accuracy. That is, it is preferable that the position detection electrode 12 has a high resistance. This is because the influence of the parasitic resistance of the external circuit can be reduced by using the high-resistance position detecting electrode 12. Therefore, the position detection electrode 12 is preferably formed of a transparent conductive oxide having a higher electrical resistance than a metal material such as aluminum. Specific examples of the transparent conductive oxide include indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO), and the like.

  Next, the basic principle of two-dimensional position detection of the so-called capacitive touch panel 10 will be described with reference to FIG.

The electrode terminals 14a, 14b, 14c, and 14d are connected to the ground via a current-voltage conversion resistor r and an AC power supply circuit 20, respectively. The electrode terminals 14a, 14b, 14c, and 14d are each connected to a current detection circuit. The electrode terminals 14a, 14b, 14c, and 14d are each supplied with a voltage of an isotopic potential by a power supply circuit. The currents flowing through the electrode terminals 14a, 14b, 14c, and 14d due to the contact of the pen, the fingertip 5, etc. are assumed to be i ₁ , i ₂ , i _3, and i ₄ , respectively. In this case, the following Expression 9 and Expression 10 are obtained in the same manner as the above calculation.

X = k ₁ + k ₂ · (i ₂ + i ₃ ) / (i ₁ + i ₂ + i ₃ + i ₄ ) (Formula 9)
Y = k ₁ + k ₂ · (i ₁ + i ₂ ) / (i ₁ + i ₂ + i ₃ + i ₄ ) (Formula 10)
Here, X is the X coordinate of the touched contact position A on the position detection electrode 12, and Y is the Y coordinate of the contact position A on the position detection electrode 12. K ₁ is an offset, and k ₂ is a magnification. k ₁ and k ₂ are constants that do not depend on human impedance.

Based on Equation 9 and Equation 10, the contact position A can be calculated from the measured values of i ₁ , i ₂ , i _3, and i ₄ flowing through the electrode terminals 14a, 14b, 14c, and 14d.

  This embodiment is similar to the case of FIG. 13 described above in that the position detection signals are detected from the four corners of the first short-circuit wiring 52 arranged on the upper side and the lower side in FIG.

  By the way, since the common electrode for driving the liquid crystal provided in the liquid crystal display device is usually made of a transparent conductive oxide such as ITO, it is compatible with the electrode for position detection. However, in order to obtain higher detection accuracy of the contact position A, the higher the resistance of the electrode, the better. In particular, when the position detection electrode is also used as a common electrode, the intensity of the signal detected by the position detection electrode becomes extremely weak when touched through the glass substrate. It has been found by the inventor's research that the surface resistance of the electrode is desirably about 1000Ω / □.

  On the other hand, from the viewpoint of display quality, the resistance of the counter electrode (that is, the position detection electrode) is preferably as small as possible. Usually, film forming conditions are selected so as to reduce the specific resistance of ITO as much as possible, and the film thickness is optimized as much as possible while considering the balance with the transmittance. As a result, the surface resistance of the counter electrode is usually set to about 10Ω / □.

If the counter electrode (position detection electrode) is formed with a surface resistance of about 10Ω / □, the variation in the resistance value depending on the contact position A touched through the glass substrate (that is, R in the above equation) ₁ or R ₂ ) is limited to about several Ω at the maximum. Since this resistance value is about the same as the parasitic resistance of the external circuit, there is a possibility that only a single digit value can be secured even if the S / N ratio is maximum. Therefore, even if a common counter electrode is used as it is as a position detection electrode as described above, it is difficult to improve the detection accuracy of the touched contact position A.

  However, according to the first embodiment, the above-described problem is solved, and there is a special effect as described below.

  First, since the counter electrode 35 is shared with the position detection electrode for detecting the contact position A of the contact body 5 as a premise, the entire apparatus is compared with the case where the position detection electrode is provided separately from the counter electrode. Can be made thinner.

  In addition, since a plurality of opposing electrodes 35 are formed so as to extend along the signal lines 27, the surface resistance of the opposing electrodes 35 in the direction of the signal lines 27 is kept relatively low. Since the resistance can be relatively increased, it is possible to suppress the deterioration of display quality and increase the position detection accuracy of the contact body 5.

  That is, even when the counter electrode 35 has a relatively low surface resistance as in the conventional case, as shown in FIG. 1, it is formed in a long pattern with a long distance and a narrow width along the direction of the signal line 27. Therefore, the resistance between both ends of the signal line 27 is increased, and the detection accuracy of the contact position A in the direction of the signal line 27 can be remarkably improved.

  Furthermore, since it is not necessary to increase the surface resistance of the counter electrode 35, it is possible to suppress a decrease in display quality such as a decrease in contrast and occurrence of unevenness. In other words, since the counter electrode 35 is patterned in a long shape in the direction of the signal line 27 instead of in the direction of the scan line 26, when a certain scan line 26 is selectively written, For example, only a writing load for one pixel is applied. Therefore, the load applied to all the long counter electrodes 35 is equalized, so that the magnitude of the load at an arbitrary point can be maintained at the same level as that of the planar counter electrode, and a new display defect occurs. Absent.

  Furthermore, since each counter electrode 35 extends in the direction of the signal line 27 and the scanning line 26 direction is separated from each other, even if a ripple occurs on the counter electrode 35, the counter electrode 35 does not propagate in the direction of the scanning line 26. Crosstalk due to a load during writing can be suppressed.

  Furthermore, since the terminal portion 40 formed on the active matrix substrate 21 is electrically connected to the input / output portion 38 of the counter electrode 35 via the transition portion 37, the signal input / output to / from the counter electrode 35 is transmitted. Therefore, transmission / reception can be performed not with the counter substrate 22 side but with the active matrix substrate 21 side.

  Therefore, since the input circuit 41 and the detection circuit 42 can be formed not on the counter substrate 22 but on the active matrix substrate 21, it is not necessary to newly provide a space for arranging the detection circuits 42 and the like on the counter substrate 22. As a result, since the input circuit 41 and the detection circuit 42 can be arranged using the mounting area 34 originally provided on the active matrix substrate 21, an increase in the frame area due to an increase in the size of the counter substrate 22 is suppressed. be able to. That is, it is possible to reduce the size of the liquid crystal display device 1 while reducing the frame area and maintaining the size of the display area. Further, since the input circuit 41 and the detection circuit 42 are not provided on the counter substrate 22 side but are provided on the active matrix substrate 21 side where the TFTs 30 and the like are formed, the complexity of the mounting process can be avoided and an increase in manufacturing cost can be suppressed. Can do.

  Furthermore, since the plurality of terminal portions 40 are short-circuited by the first short-circuit wiring 52, a position detection signal indicating the contact position A can be read from both ends of the first short-circuit wiring 52. Thus, not only the signal line direction but also the contact position information in the scanning signal direction can be detected.

  By the way, the first short-circuit wiring 52 for short-circuiting the terminal portions 40 is preferable in that the higher the resistance, the higher the position detection accuracy in the scanning line direction, but the display signal is transmitted without delay to maintain the display quality. In this respect, it is not desirable to have a high resistance as described above. According to the first embodiment, by switching the switch unit 50, a display signal can be input to the counter electrode 35 via the common wiring 51 having a relatively low resistance value, and the position detection signal has a relatively high resistance value. It can be detected from the counter electrode 35 via the first short-circuit wiring 52. That is, it is possible to achieve both good display quality and highly accurate contact position detection.

  Furthermore, as described above, in order to accurately detect the contact position A, the resistance value of the conductor in the direction in which position detection is desired needs to be sufficiently larger than the external parasitic resistance. In particular, in the first embodiment, it is difficult to accurately detect the scanning line direction unless the resistance value of the first short-circuit wiring 52 is sufficiently large. Generally, the parasitic resistance between the external circuit and the connection between the external circuit and the display element is about several ohms, and therefore it is necessary to allow about 10 ohms at maximum. On the other hand, no matter how much the position detection accuracy of the touch panel is kept small, it is necessary to allow an error of about ± 10%. Therefore, considering the detection error of 10%, for example, the resistance of the first short-circuit wiring 52 The value should be at least 100Ω, which is 10 times the parasitic resistance of 10Ω.

  In the present embodiment, since the resistance value between both ends of the first short-circuit wiring 52 in the signal line direction is defined to be 100Ω or more, the contact position A can be detected with high accuracy regardless of the influence of the detection error and the parasitic resistance. It can be performed.

  As the material of the first short-circuit wiring 52, ITO, IZO, or the like can be applied as a material having a relatively high resistance, like the material of the counter electrode 35 described above. Further, the use of the material originally used for the active matrix substrate 21 does not increase the number of processes. Further, the silicon film doped with the impurity element appropriately is a promising candidate as a high resistance wiring material for the first short-circuit wiring 52. Moreover, it is preferable that resistance is low about the extraction | drawer wiring part pulled out to the both sides from the wiring part to which the terminal part 40 of the 1st short circuit wiring 52 is connected. Therefore, it is desirable that the lead-out wiring portion of the first short-circuit wiring 52 is formed of a metal wiring film, like the scanning line 26 and the signal line 27.

  Further, the long counter electrode 35 in the first embodiment is patterned corresponding to each line of the signal lines 27. However, if the detection accuracy may be relatively low, the long counter electrodes 35 may be formed on the plurality of signal lines 27. You may form across. For example, it is possible to correspond three lines of RGB to one long counter electrode 35. In this case, the size of the external circuit can be reduced to one third, so that the entire display device can be realized at low cost. Further, regarding the above-described crosstalk problem, when three RGB pixels are used as one constituent unit of dots, the long counter electrode 35 is not shared between adjacent constituent units. Even if they affect each other, they are not visible as crosstalk.

  Further, when there is no possibility of crosstalk as a device characteristic, the long counter electrode 35 may be shared so as to correspond to more lines. In this case, the width of the elongated counter electrode 35 may be determined depending on how much detection resolution is desired in the direction of the scanning line 26. By using the elongated counter electrode 35 having a larger width, the number of external circuits can be reduced, and a simple and inexpensive system can be obtained. However, as described above, the resistance value at both ends of the counter electrode 35 needs to be a certain amount of high resistance. Therefore, the length is long considering the detection resolution, the detection accuracy, and the complexity of the external system. The width of the counter electrode 35 may be determined. Incidentally, control such as dot inversion is also effective to create a case where there is no fear of the crosstalk.

<< Embodiment 2 of the Invention >>
4 and 7 show Embodiment 2 of the present invention. FIG. 4 is a plan view showing the main part of the liquid crystal display device 1. FIG. 7 is a cross-sectional view schematically showing a cross-section of the main part of the liquid crystal display device 1. In the following embodiments, the same portions as those in FIGS. 1 to 3 and 6 are denoted by the same reference numerals, and detailed description thereof is omitted.

In the first embodiment, the switch unit 50 is provided corresponding to each of the plurality of counter electrodes 35, whereas in the second embodiment, the switch unit 50 is provided at a plurality of locations smaller than the number of the counter electrodes 35. It is arranged. As shown in FIG. 4 and FIG. One end is connected to the first short-circuit wiring 52, and the other end is connected to the display signal supply unit 53.
It is desirable that the switch unit 50 is installed at three or more points in total to receive display signals.

  In order to supply the display signal to the counter electrode 35 and drive the long counter electrode 35 corresponding to the signal line 27, the drive capability of the drive circuit of the signal line 27 should be approximately the same. Is considered sufficient.

  For example, in the case of a so-called driver monolithic display device in which signal line drivers are integrally formed on the active matrix substrate 21, or output from an external signal line driving circuit is distributed to a plurality of signal lines by switching elements on the active matrix substrate. In the case of the method, the channel width of the switching element at the final stage to the output to the signal line 27 in the active matrix substrate 21 determines the output impedance. Therefore, it is desirable that the switch unit 50 that should supply a signal to the counter electrode 35 is also provided in each counter electrode 35 with an output capability equivalent to that of the last-stage switching element to the signal line 27.

  However, the plurality of signal lines 27 are not all driven at the same time. For example, the number of outputs of the external drive circuit is reduced to one third, and the signal lines 27 are divided into three parts on the active matrix substrate 21 (that is, supplied) In the case of a method in which one horizontal period is divided into supply periods to the RGB signal lines 27 and time-division supply is performed), the remaining two signals are excluded except for one actually supplied with a signal. Since the line does not generate a load as the counter electrode 35, it is sufficient that the driving capacity of one counter electrode 35 per three counter electrodes 35 is sufficient. That is, when the transistor size of the switch unit 50 is made equal to the switching element at the last stage to the signal line 27, the number of the switch units 50 may be reduced to one third.

  In the case of a dot sequential analog full monolithic display device or the like, the required transistor size is determined according to the number of phase expansions. For example, in the case of 16-phase development, there are only 16 × 3 (RGB) = 48 signal lines 27 written at one time. 48 is sufficient as the capacity of the switching element.

  In addition, whether the output of the drive circuit is divided and input to the signal line 27 or in the case of full monolithic, the transistor size of the switch unit 50 is increased to increase the output capability, thereby further improving the switching element. The number can be reduced. However, when the number of the switch units 50 is extremely reduced, since the first short-circuit wiring 52 has a high resistance, there is a difference in waveform rounding between the vicinity connected to the switch unit 50 and the distant position. This may cause a display defect in accordance with the installation interval of the switch unit 50. For this reason, it is desirable that the number of counter electrodes 35 carried by one switch unit 50 is not excessively increased, and it is desirable to optimize while determining whether there is an influence on display quality.

  In the case of full monolithic, for example, after supplying signals to the signal lines from the 12kth to the 12k + 11th, the next scan is performed for each block such as 12 (k + 1) th to 12 (k + 1) + 11th. It is normal to go. However, in the case of the driving method such as the above-mentioned three divisions, normally, 3k-1 (k = 1, 2,...) Is next to the 3k-2 (k = 1, 2,...) Supply. ..)), And then the 3k (k = 1, 2,...) Supply, the signal lines 27 separated by a certain number are simultaneously selected. Therefore, by arranging the switch units 50 in a distributed manner, the load is not biased toward the specific switch unit 50, and the gradient of the input waveform to the counter electrode 35 is generated even if the first short-circuit wiring 52 has a high resistance. This makes it difficult to prevent display problems. Therefore, it can be said that it is ideal to arrange one switch unit 50 for every n counter electrodes in the n-division driving method.

  As described above, according to the second embodiment, the number of switch units 50 can be reduced to a necessary and sufficient number. Therefore, it is possible to reduce the formation region of the switch unit 50 and further reduce the frame region. Furthermore, since the number of the switch units 50 can be reduced, it is possible to suppress a decrease in yield due to a failure of the switch unit 50 itself.

  Further, by making the number and arrangement positions of the switch sections 50 appropriate in consideration of the resistance value of the first short-circuit wiring 52, even if the number of the switch sections 50 is small, the position detection signal as described above. Both accurate detection and improved display quality can be achieved.

<< Embodiment 3 of the Invention >>
5 and 8 show Embodiment 3 of the present invention. FIG. 5 is a plan view showing a main part of the liquid crystal display device 1. FIG. 8 is a cross-sectional view schematically showing a cross-section of the main part of the liquid crystal display device 1.

  In the first embodiment, the plurality of counter electrodes 35 are separately formed on the counter substrate 22, whereas in the third embodiment, each counter electrode 35 is short-circuited on the counter substrate 22.

  That is, as shown in FIG. 5, the plurality of counter electrodes 35 are short-circuited to each other by the second short-circuit wiring 55 formed on the counter substrate 22 at both ends thereof. The second short-circuit wiring 55 is made of ITO, which is a transparent conductive film, like the counter electrode 35, and is formed integrally with the counter electrode 35. As a result, the second short-circuit wiring 55 is a sufficiently high resistance wiring for obtaining the accuracy of the contact position A.

  As shown in FIG. 8, the terminal portion 40 faces the first terminal portion 61 disposed opposite to both ends of the second short-circuit wiring 55 and the intermediate portion of the second short-circuit wiring 55 or the counter electrode 35. It has the 2nd terminal part 62 arranged.

  Further, as shown in FIGS. 5 and 8, the transition portion 37 includes a first transition portion 63 that connects the first terminal portion 61 and the second short-circuit wiring 55, a second terminal portion 62, and the second short-circuit wiring 55. Or it has the 2nd transition part 64 which connects the counter electrode 35. FIG. Thus, the switch unit 50 has one end connected to the second terminal unit 62 and the other end connected to the display signal supply unit 53.

  In other words, the second short-circuit wiring 55 is provided with the first transition portion 63 and the second transition portion 64 at a plurality of locations at predetermined intervals, and the first transition portion 63 and the second transition portion 64 are arranged in the above-described embodiment. 1, it is composed of gold particles mixed in the sealing material. As shown in FIG. 8, each counter electrode 35 is electrically connected to the detection circuit 42 via the second short-circuit wiring 55, the first transition portion 63, and the first terminal portion 61. Each counter electrode 35 is electrically connected to the display signal supply unit 53 through the second transition portion 64, the second terminal portion 62, the switch portion 50, and the common wiring 51. Further, each counter electrode 35 is electrically connected to the selection signal supply unit 54 via the second transition portion 64, the second terminal portion 62, and the selection control wiring 56. That is, according to the third embodiment, it is possible to connect to an external circuit provided in the mounting region 34 via the wiring pattern on the active matrix substrate 21.

  About the switch part 50, it arrange | positions at several places smaller than the number of the counter electrodes 35 similarly to the said Embodiment 2. FIG. It is desirable that the size and arrangement of the switching elements of the switch unit 50 be defined based on the same idea as in the second embodiment.

  Since the second transition portion 64 is limited to a relatively small number, for example, when the transfer using gold particles is difficult in terms of cost, or due to restrictions on the arrangement of the sealing material, between the substrates 21 and 22 at the seal portion. If it is difficult to make contact, it is possible to apply a carbon paste separately. However, in the case of applying the carbon paste, it is difficult to narrow it to a coating pitch of several millimeters or less, so the configuration of this embodiment is effective.

  In order to input and output position detection signals to and from the counter electrode 35, the four corners of the counter substrate 22 are formed so as to protrude beyond the active matrix substrate 21 (or at least two sides facing the counter substrate 22 are active matrix). The detection circuit 42 may be directly connected to the input / output unit 38 provided on the counter substrate 22, so as to be larger than the substrate 21. However, it is possible to transfer to the active matrix substrate 21 side through a conductive material such as carbon paste and to input / output signals only on the active matrix substrate 21 side in the same way as the display signals. Also preferred.

  Therefore, according to the third embodiment, it is possible to reduce the number of transition portions 37 by forming the transition portions 37 (the first transition portion 63 and the second transition portion 64) in the second short-circuit wiring 55. . Therefore, it is possible to reduce the frame area by reducing the area necessary for forming a large number of transition portions 37. In addition, since it is not necessary to provide a wiring for short-circuiting the terminal portions 40 on the active matrix substrate 21, this also makes it possible to reduce the frame area. In addition, by providing a larger number of transition portions 37 than necessary, even if some of the transition portions 37 are defective, the conduction state between the terminal portion 40 and the counter electrode 35 side is maintained. Thus, the yield can be improved.

  Further, since the counter electrode 35 and the second short-circuit wiring 55 are integrally formed of a transparent conductive film, the second electrode having the high resistance necessary for increasing the detection accuracy of the contact position A using the electrode material of the counter substrate 22. The short circuit wiring 55 can be obtained.

<< Other Embodiments >>
In this specification, the “display medium layer” is a layer for controlling display, and the light transmittance is modulated by a potential difference between electrodes facing each other (between the pixel electrode 29 and the counter electrode 35). A layer or a layer that emits light by current flowing between electrodes facing each other. Specific examples of the display medium layer include the above-described liquid crystal layer, inorganic or organic EL layer, luminescent gas layer, electrophoretic layer, electrochromic layer, and the like.

  In addition to the TFT 30, for example, an MIM (metal-insulator-metal) or the like can be applied as the switching element.

  As described above, the present invention is useful for a display device having a touch panel function, and is particularly suitable for increasing the position detection accuracy, suppressing deterioration in display quality, and reducing the frame area.

FIG. 3 is a plan view illustrating a main part of the liquid crystal display device according to the first embodiment. It is a top view which expands and shows a part of active matrix substrate. It is sectional drawing which shows the structure of a liquid crystal display device typically. FIG. 6 is a plan view illustrating a main part of a liquid crystal display device according to a second embodiment. FIG. 6 is a plan view illustrating a main part of a liquid crystal display device according to a third embodiment. 2 is a cross-sectional view schematically showing an enlarged part of the liquid crystal display device of Embodiment 1. FIG. FIG. 5 is a cross-sectional view schematically showing an enlarged part of the liquid crystal display device of Embodiment 2. FIG. 5 is a cross-sectional view schematically showing an enlarged part of the liquid crystal display device of Embodiment 3. It is the schematic plan view which represented typically the structure of the basic capacitive touch panel. It is the XX sectional view taken on the line in FIG. FIG. 3 is a schematic plan view schematically illustrating a configuration in the vicinity of a position detection electrode. It is a circuit diagram containing the one-dimensional resistor pinched | interposed into the electrode terminal. It is a circuit diagram containing the two-dimensional resistor enclosed by the electrode terminal.

Explanation of symbols

A Contact position 1 Liquid crystal display device 5 Fingertip (contact body)
10 capacitive touch panel 21 active matrix substrate 22 counter substrate 23 liquid crystal layer 26 scanning line 27 signal line 28 pixel 30 TFT
34 mounting area 35 counter electrode 37 transition part 38 input / output part 40 terminal part 41 input circuit (input means)
42 Detection circuit (detection means)
50 switch section 51 common wiring 52 first short-circuit wiring 53 display signal supply section 54 selection signal supply section 55 second short-circuit wiring 56 selection control wiring 61 first terminal section 62 second terminal section 63 first transition section 64 second transition Part

Claims (10)

An active matrix substrate having a plurality of scanning lines, a plurality of signal lines, a plurality of pixel electrodes, and a switching element electrically connected to the plurality of pixel electrodes;
A counter substrate disposed opposite to the active matrix substrate and having a counter electrode facing the pixel electrode;
A display medium layer provided between the pixel electrode and the counter electrode for controlling display;
A display device configured to detect a position of the contact body by detecting a capacitance formed between the contact body in contact with the counter substrate and a part of the counter electrode;
The counter electrode is formed in a plurality of elongated shapes so as to extend along the signal line,
A terminal portion formed on the active matrix substrate and electrically connected to the plurality of counter electrodes via a transition portion;
An input unit connected to the terminal unit via a switch unit and inputting a predetermined signal to the counter electrode;
A display device comprising: a detection unit that is electrically connected to the terminal portion and receives a signal from the counter electrode that indicates the position of the contact body. In claim 1,
The display device is characterized in that a plurality of the terminal portions are formed corresponding to the plurality of counter electrodes, and are short-circuited to each other by a first short-circuit wiring formed on the active matrix substrate. In claim 1,
A plurality of the terminal portions are formed corresponding to the plurality of counter electrodes, and each of the terminal portions is connected to the corresponding counter electrode via the transition portion. In claim 1,
The input means includes a selection signal supply unit that supplies a selection signal for switching control of the switch unit to the switch unit, and a display signal supply unit that supplies a display signal to the counter electrode,
A plurality of the switch units are provided corresponding to the plurality of terminal units, and one end is connected to the corresponding terminal unit, and the other end is connected to the display signal supply unit. Display device. In claim 2,
The input means includes a selection signal supply unit that supplies a selection signal for switching control of the switch unit to the switch unit, and a display signal supply unit that supplies a display signal to the counter electrode,
One end of the switch unit is connected to the first short-circuit wiring, and the other end is connected to the display signal supply unit. In claim 5,
The other end of the switch unit is connected to the display signal supply unit via a common wiring,
A display device, wherein a resistance value between both ends of the common wiring is lower than a resistance value between both ends of the first short-circuit wiring. In claim 1,
The display device, wherein the plurality of counter electrodes are short-circuited to each other by a second short-circuit wiring formed on the counter substrate. In claim 7,
The input means includes a selection signal supply unit that supplies a selection signal for switching control of the switch unit to the switch unit, and a display signal supply unit that supplies a display signal to the counter electrode,
The terminal portion includes a first terminal portion disposed opposite to both ends of the second short-circuit wiring, and a second terminal portion disposed opposite to the intermediate portion of the second short-circuit wiring or the counter electrode. Have
The transition portion includes a first transition portion that connects the first terminal portion and the second short-circuit wiring, and a second transition portion that connects the second terminal portion and the second short-circuit wiring or the counter electrode. Have
One end of the switch unit is connected to the second terminal unit, and the other end is connected to the display signal supply unit. In claim 6,
The display device, wherein the counter electrode and the second short-circuit wiring are integrally formed of a transparent conductive film. In claim 1,
The display device, wherein the display medium layer is a liquid crystal layer.

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