JP2007200039A - Touch panel mechanism and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a touch panel mechanism capable of preventing generation of sounding even when using a touch panel. <P>SOLUTION: A position detection signal inputted to the touch panel 1 from a touch panel controller 4, and fed back to the touch panel controller 4 is a signal in-phase to and synchronizing with a VCOM signal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a touch panel mechanism and a display device, and more particularly to a liquid crystal display device in which a touch panel and a liquid crystal panel are opposed to each other.

  Conventionally, in a liquid crystal display device that performs line inversion driving, for example, in the case of a liquid crystal display device in which a touch panel is installed on the display surface side of the liquid crystal panel, there has been a problem that a sound that causes discomfort to humans occurs. . The present inventors paid attention to this problem, and as a result of intensive studies, the cause thereof was considered as follows. That is, since the surface of the liquid crystal panel (more precisely, the surface of the polarizing plate) and the back surface of the touch panel facing the liquid crystal panel are charged for some reason, an electric field generated by the electrode of the liquid crystal panel causes a gap between the liquid crystal panel and the touch panel. It was thought to be caused by the vibration of the space.

This principle will be described in detail. For example, paying attention to a point a on the back surface of the touch panel 101 as shown in FIG. 7 and a point b on the surface of the liquid crystal panel 102 facing the point a, the charge charged at the point a of the touch panel 101 is qa, the liquid crystal panel If the electric charge charged at the point b of 102 is qb, the forces Fa and Fb acting on these electric charges qa and qb, respectively, can be obtained from the following equations. For convenience, a component only in the stacking direction of the liquid crystal panel 102 and the touch panel 101 is considered as a force component (and an electric field component).
Fa = qa × Ea
Fb = qb × Eb
Ea is the electric field intensity at point a, and Eb is the electric field intensity at point b.

Here, the electric field strength Ea is obtained by the following equation. Strictly speaking, the electric field strength Ea includes electric field components due to signals applied to the upper and lower electrodes of the touch panel 101 and the pixel electrodes or segment electrodes of the liquid crystal panel 102, but they are constant so as to cause noise. Since there is almost no variation in frequency, it is omitted here.
Ea = Ecoma (t) + Eqa + Eqb
Note that Ecoma (t) is due to driving of the liquid crystal panel (counter electrode) among electric field components at point a (function of time), and Eqa is due to electric charge qa among electric field components at point a. , Eqb is due to the electric charge qb among the electric field components at the point b.

  Here, Ecoma (t) is an electric field generated by a counter electrode signal (common electrode signal, VCOM signal) applied to the counter electrode. Since the potential of this VCOM signal changes depending on the driving frequency, the value of Ea is It is not constant but fluctuates with the driving frequency component, so Fa also fluctuates with the driving frequency. The same applies to the force Fb acting on the point b of the liquid crystal panel 102.

  Further, considering the entire back surface of the touch panel 101, if the total charge on the back surface of the touch panel 101 is Qtp, it is considered that Qtp, that is, the force Ftp acting on the entire back surface of the touch panel 101 also varies. Similarly, when the total charge on the entire surface of the liquid crystal panel 102 is Qlc, the force Flc acting on the entire surface of the liquid crystal panel 102 is also considered to vary.

  That is, if Ea and Eb are constant, the forces acting on Qtp and Qlc are constant, so that vibration of the liquid crystal panel 102 and the touch panel 101 does not occur, but Ea and Eb fluctuate with the driving frequency as described above. It is considered that the front surface of the panel 102 or the back surface of the touch panel 101 vibrates at the same frequency as the driving frequency, which vibrates the space between the liquid crystal panel 102 and the touch panel 101 and generates sound.

  On the other hand, the following methods can be considered as a method of reducing and reducing such a sound.

  First, there is a method of increasing or decreasing the driving frequency of the liquid crystal panel, which causes a sound, to be out of the human audible frequency range or to make it difficult to hear. However, increasing the drive frequency leads to an increase in power consumption, and in the case of a liquid crystal display device, increasing the drive frequency shortens the charging time for the liquid crystal. Problems such as the occurrence of Further, when the drive frequency is lowered, there is a problem of occurrence of flicker.

  Further, a method of preventing the fluctuation component itself of the Coulomb force on the panel surface from being generated by using the drive signal as DC drive is also conceivable. However, in order to set the drive signal to DC drive, the output voltage of the source becomes higher by that amount, so it is necessary to use a high-voltage product for the source driver, which causes a problem of increased power consumption.

  In addition, a method of preventing noise by eliminating the air layer between the liquid crystal panel and the touch panel by sticking the surface of the touch panel to the surface of the liquid crystal panel with glue or the like is also considered. It is done. However, when a touch panel or the like is directly attached to the panel surface, there are display quality problems due to peeling on the adhesive surface and a problem that the attaching operation is difficult.

  Another possible method is to suppress the charging of the liquid crystal panel surface and the back surface of the touch panel as much as possible so that vibration due to Coulomb force does not occur. However, in order to prevent electrification, it is necessary to carry out static elimination work while managing the charge amount with a static elimination blower or the like, which reduces productivity due to time spent on static elimination work, and manages the charge amount. There is a problem of capital investment.

  Furthermore, it is possible to reduce the distance between the liquid crystal panel and the touch panel that faces it and reduce the Coulomb force to suppress the generation of vibrations, or even make a level that prevents the sound of air vibrations from being heard even if it vibrates. . However, in order to increase the distance in this way, there is a problem that the dimension in the thickness direction of the display device must be increased.

  In addition, as what solves the influence on the position detection precision by the noise around a touch panel (resistive film tablet device), in Patent Document 1, a transparent electrode layer is formed on the outer surface of the touch panel, and the transparent electrode layer is grounded. It is disclosed. Thereby, since charging is suppressed on the back surface (surface on which the transparent electrode layer is formed) of the touch panel, it is considered that it is effective against noise caused by vibration on the back surface of the touch panel. However, when another member is further added to the back surface of the transparent electrode, it is considered that the above-described sounding occurs due to charging of the member.

  In addition, as in Patent Document 2, in order to prevent vibration of the optical sheet disposed in the gap portion between the liquid crystal panel and the backlight, the transparent electrode sheet is provided on the gap portion between the liquid crystal panel and the backlight or on the back side of the backlight. Is known, and a voltage that changes the driving frequency of the liquid crystal panel in synchronization with the opposite phase is applied to the transparent electrode sheet. According to this Patent Document 2, the periodic fluctuation of the electric field in the optical sheet generated based on the periodic potential change of the common electrode layer of the liquid crystal panel can be reduced by the voltage supplied to the transparent electrode sheet. Therefore, it is considered that a certain effect can be expected in preventing the vibration of the optical sheet. However, such a transparent sheet is disposed on the back surface side of the liquid crystal panel, and it is considered that the effect of preventing the sounding phenomenon in the touch panel located on the display surface side of the liquid crystal panel as described above is poor. . Further, when this transparent electrode sheet is disposed in the gap between the backlight and the liquid crystal panel, there is a problem that the light use efficiency is lowered due to the presence of an air layer between the transparent electrode sheet and the backlight.

  In view of the problem of the sound generation phenomenon in the liquid crystal display device having the touch panel and the liquid crystal panel as described above, the inventor has a period generated based on the driving signal of the common electrode layer of the liquid crystal panel as in Patent Document 3. A means to apply a sound improvement signal that generates an electric field that changes the period of the electric field to the electrode layer of the touch panel has been proposed.

  The touch panel of the liquid crystal display device detects a position where the user touches by detecting an electrical change generated between the pair of electrode layers facing each other with a predetermined gap and the touch panel touching the user. And a touch panel controller for detection. The sound improvement signal is applied to at least one of the pair of electrode layers of the touch panel. Here, the liquid crystal display device includes a sound generation improvement signal generation unit that generates a sound generation improvement signal, a switch unit that switches electrical connection between the sound generation improvement signal generation unit and the electrode layer between a conductive state and a disconnected state, and a switch unit The first signal line that electrically connects the sound generation improvement signal generator, the second signal line that electrically connects the switch means and the electrode layer, and the switch means and the touch panel controller electrically And a third signal line to be connected.

Then, the switch means makes the first signal line and the second signal line conductive, and disconnects the second signal line and the third signal line, so that the sound generation improvement signal generation unit The generated sound improvement signal is supplied to the touch panel, and the first signal line and the second signal line are disconnected, and the second signal line and the third signal line are conductive. Thus, the touch panel controller can input and output the touch panel position detection signal to the touch panel, and the touch panel controller can detect the position touched by the user. Further, the switching between the conduction state and the disconnection state by the switch means is made based on the switching signal generated by the switching signal generation unit.
Japanese Utility Model Publication No. 7-20623 (published on April 11, 1995) JP 2004-184885 A (published July 2, 2004) JP 2005-164709 A (published June 23, 2005)

  However, in the above configuration, while the sound generation improvement signal is supplied to the touch panel, that is, the first signal line and the second signal line are in a conductive state, and the second signal line and the third signal line are connected. While in the disconnected state, the sound is improved, but the position touched by the user cannot be detected. On the other hand, while the touch panel controller detects the position touched by the user, that is, the second signal line and the third signal line are brought into conduction, and the first signal line and the second signal line are disconnected. While it is in a state, it is possible to detect the position touched by the user, but it is not possible to prevent sounding.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a touch panel disposed on a panel having a common electrode driven at a predetermined frequency, such as a display panel, with a certain gap from the panel. A touch panel mechanism including a control unit for detecting a position touched by a user on the touch panel, and a touch panel mechanism capable of preventing the generation of sound even when the touch panel is used, and a display device including the touch panel mechanism It is to be.

  In order to solve the above problems, the touch panel mechanism according to the present invention is arranged with a predetermined distance from a display panel having a common electrode layer to which a voltage signal changing at a predetermined frequency is applied, and is a pair of opposed panels. In a touch panel mechanism including a touch panel having an electrode layer and a control unit that detects a position touched by a user on the touch panel, a position detection signal that is input from the control unit to the touch panel and fed back to the control unit. The signal is in phase with and synchronized with the voltage signal.

  According to the above configuration, the position detection signal that is input to the touch panel to detect the position touched by the user from the control unit and fed back to the control unit is a voltage signal applied to the common electrode layer. The signal is in phase and synchronized with the signal. According to this, sounding can be improved without providing an analog switch as in Patent Document 3. In addition, since such an analog switch is not provided, sounding can be improved even when the touch panel is used. In other words, a signal that is in phase and synchronized with the voltage signal is always input from the control unit to the touch panel regardless of whether the touch panel is used or not. Can be improved. In addition, the touch panel can be used while improving sound generation (the position touched by the user can be detected).

  In addition, when applying a signal that is in phase and synchronized with the voltage signal applied to the common electrode phase to the touch panel, the reason for improving sound generation is the temporal change in the force acting on the back surface of the touch panel and the surface of the display panel. This is because it can be reduced.

  In the display device of the present invention, it is preferable that the touch panel mechanism further includes a display panel.

  According to the above configuration, as described above, it is possible to provide a display device that can improve sound generation even when the touch panel is used.

  In the display device of the present invention, it is preferable that the position touched by the user on the touch panel is detected by the set of electrode layers contacting each other.

  Here, in the display device of the present invention, as described above, the electrode layers at positions touched by the user are in contact with each other, and the control unit detects the position touched by the user on the touch panel.

  The display device of the present invention preferably further includes a signal generation unit that generates the voltage signal.

  As described above, the touch panel mechanism of the present invention is a signal in which the position detection signal input from the control unit to the touch panel and fed back to the control unit is in phase with and synchronized with the voltage signal.

  Therefore, there is an effect that it is possible to provide a touch panel mechanism that can prevent the generation of sound even when the touch panel is used.

  An embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the display device of the present invention supplies a touch panel 1, a liquid crystal panel (display panel described in claims) 2 provided opposite to the touch panel 1, and the liquid crystal panel 2. A signal generation unit 3 that generates various liquid crystal drive signals to be performed, and a touch panel controller (TPC; patent) that inputs a position detection signal to the touch panel 1 and applies feedback in order to detect a position touched by the user on the touch panel 1 The control unit 4 described in the claims is provided. A configuration in which the touch panel 1 and the liquid crystal panel 2 face each other will be described later with reference to FIG. The display device is a device in which the touch panel 1 is arranged at a predetermined interval on the display surface side of the liquid crystal panel 2. Here, the display device includes not only a liquid crystal display device but also a CRT (Cathode Ray Tube), an organic EL display device, or a plasma display. A mechanism constituted by the touch panel 1 and the TPC 4 is referred to as a touch panel mechanism.

  As shown in FIG. 2, the touch panel 1 includes a transparent plate 5, a first sheet member 6 in which the transparent plate 5 is disposed on the back surface, and a first layer formed by laminating on the surface of the first sheet member 6. An electrode layer 7, a second electrode layer 8 disposed so as to face the first electrode layer 7 with a predetermined interval, and a second sheet member 9 in which the second electrode layer 8 is laminated on the back surface I have. The first electrode layer 7 and the second electrode layer 8 (a set of electrode layers recited in the claims) are adhesive members disposed at both ends of these members as shown in FIG. 10 is connected.

  The second sheet member 9 is composed of a flexible member. Therefore, when the user touches the second sheet member 9, the second sheet member is bent, and the first electrode layer 7 and the second electrode layer 8 come into contact with each other. .

  On the other hand, the liquid crystal panel 2 includes, in order from the touch panel 1 side, a first polarizing plate 11, a first transparent substrate 12, a counter electrode layer (common electrode layer described in claims) 13, a liquid crystal layer 14, and a pixel electrode. A layer 15, a second transparent substrate 16, and a second polarizing plate 17 are provided. That is, a pair of the first transparent substrate 12 and the second transparent substrate 16 arranged to face each other sandwich the liquid crystal layer 14, and the counter electrode layer 13 is disposed on the liquid crystal layer 14 side of the first transparent substrate 12. The pixel electrode layer 15 is disposed on the liquid crystal layer 14 side of the second transparent substrate 16. Further, the pixel electrode layer 15 and the counter electrode layer 13 are bonded together by a sealing material 18 as shown in FIG.

  The signal generator 3 generates a drive signal for the display device. One of the drive signals is a common electrode signal (VCOM signal; a voltage signal described in claims) whose voltage changes at a predetermined frequency. The signal generation unit 3 outputs the VCOM signal to the counter electrode layer 13. Is applied.

  The TPC 4 is connected to the pair of electrode layers 7 and 8 of the touch panel 1, and detects an electrical change that occurs between the pair of electrode layers 7 and 8 of the touch panel 1 that contacts the touch panel 1 when the user touches the touch panel 1. Thus, it has a role of detecting the position touched by the user. In this way, the TPC 4 inputs a position detection signal to the touch panel 1 and applies feedback in order to detect the position touched by the user. The position detection signal is input to the touch panel 1 regardless of whether or not the user is using the touch panel 1.

[The most important part of the present invention]
Here, it should be particularly noted that in this embodiment, the signal cycle of the position detection signal is a signal that is in phase and synchronized with the VCOM signal.

  FIG. 3A is a waveform diagram schematically showing a VCOM signal, and FIG. 3B is a waveform diagram schematically showing a position detection signal of the touch panel 1. In these waveform diagrams, the horizontal axis indicates time, and the vertical axis indicates voltage. In both waveform diagrams, GND (potential 0) is indicated by a broken line.

  As shown in these drawings, the VCOM signal becomes H at time t1, and the position detection signal also becomes H in synchronization with this timing. At time t2 (t> 1), the VCOM signal becomes L, and the position detection signal becomes L in synchronization with this timing. Further, the waveform changes at time t3 (> t2) as well as at time t1. As shown in these figures, the voltage range of the VCOM signal is −A [V] to + B [V], and the voltage range of the position detection signal is 0 [V] to + C [V]. Here, A, B, and C are arbitrary numerical values that are different for each liquid crystal panel and each display device.

  Thus, the position detection signal is a signal that is in phase and synchronized with the VCOM signal, and this signal is applied to the first electrode layer 7 or the second electrode layer 8 of the touch panel 1. More specifically, a signal is input to one of the first electrode layer 7 and the second electrode layer 8, and voltage detection (position detection) is performed on the other (the one where no signal is input). That is, when a signal is input to the first electrode layer 7, a voltage is detected at the second electrode layer 8, while when a signal is input at the second electrode layer 8, A voltage is detected by the first electrode layer 7. Further, the signal input side and the voltage detection side are usually switched at a predetermined cycle. By performing this switching, position detection in the vertical and horizontal directions (X direction / Y direction) of the touch panel can be performed alternately.

  Therefore, the electric field due to the voltage of the VCOM signal can be canceled out. For this reason, for example, even when the front surface of the liquid crystal panel 2 or the back surface of the touch panel 1 is charged, the Coulomb force acting on the charged charges can be suppressed. Therefore, vibrations of the liquid crystal panel 2 and the touch panel 2 can be suppressed, and a sounding phenomenon can be avoided. The details of the avoidance theory for this sounding phenomenon will be described later.

  4A is a pulse waveform diagram of a conventional position detection signal as a comparative example, and FIG. 4B is a pulse waveform diagram of the position detection signal of the present embodiment. As shown in these drawings, the position detection signal of the present embodiment is in phase and synchronized with the VCOM signal, unlike the conventional position detection signal as a comparative example. The position detection signal is a signal that differs depending on the VCOM signal. As described above, since the VCOM signal is different for each liquid crystal panel, the position detection signal is naturally different for each liquid crystal panel. Therefore, the voltage on the vertical axis is set to + D [V].

  Furthermore, in the present embodiment, the VCOM signal generated by the signal generation unit 3 is not input to the touch panel 1 but is input from the TPC 4 to the touch panel 1 and fed back as described above. Are in phase and synchronized with the VCOM signal. Therefore, it is possible to avoid the sounding phenomenon while using the user touch panel. This point will be described in contrast to the following [Reference Example], in which the sounding phenomenon cannot be avoided while the user is using the touch panel.

[Reference example]
In order to clarify the configuration and effects of the present invention, Patent Document 3 described above will be described as a reference example, and then compared with this reference example, an embodiment of the present invention, and more specifically, this embodiment will be described. Next, an effect that the sound generation phenomenon can be avoided while the user is using the touch panel will be described.

  As shown in FIG. 5, the display device as the reference example includes a touch panel 51, a liquid crystal panel 52, a signal generation unit 53, a touch panel controller (TPC) 54, and an analog switch 55.

  This display device is provided with an analog switch 55, which is a structural difference from the display device of the present embodiment. The analog switch 55 has a role of switching between a case where the signal generation unit 53 and the touch panel 51 are connected to each other and a case where the TPC 54 and the touch panel 51 are connected to each other.

  By connecting the signal generator 53 and the touch panel 51 to each other, the VCOM signal itself generated by the signal generator 53 is input to the touch panel 51 from the analog signal 55. Thereby, sounding can be prevented. The reason why the sounding can be prevented in this way is the same as the reason (sounding phenomenon avoidance theory) that can prevent the sounding described later in this embodiment.

  However, this reference example has a problem that sound cannot be prevented while the user is using the touch panel. That is, while the user is using the touch panel, that is, while the TPC 54 inputs the position detection signal to the touch panel 51 and receives the feedback, the touch panel 51 is connected to the TPC 54 and the signal generation unit. The connection with 53 is cut off. Therefore, the VCOM signal is not input from the signal generation unit 53 to the touch panel 51, and sounding cannot be prevented.

  On the other hand, there is a problem that the user cannot use the touch panel while sound generation is prevented. That is, while the sound generation is prevented, that is, while the signal generation unit 53 is inputting the VCOM signal to the touch panel 51, the touch panel 51 is connected to the signal generation unit 53 and connected to the TPC 54. Is blocked. Therefore, the position detection signal is not input from the TPC 54 to the touch panel 51 and cannot be used as a touch panel.

  On the other hand, according to the configuration of the present embodiment, the analog switch 55 as in the display device shown in the reference example is not provided, so the VCOM signal is always used regardless of whether the touch panel is used or not. Since in-phase and synchronized signals are input to the touch panel, the same effect as in the reference example can be obtained, and the sound can be prevented from being generated both when the touch panel is used and when it is not used.

[Sounding phenomenon avoidance theory]
The theory of avoiding the sounding phenomenon, that is, the reason why the sounding can be avoided when a signal in phase and synchronization with the VCOM signal is input to the touch panel 1 as described above will be described with reference to FIG. Explained.

First, paying attention to an arbitrary point c on the back surface (of the transparent plate 5) of the touch panel 1 and a point d on the surface (of the polarizing plate 11) of the liquid crystal panel 2 opposite thereto, the charge charged at the point c is qc, If the charge charged at the point d is qd, the forces Fc and Fd acting on qc and qd can be obtained by the following equations. (In the description, the component only in the stacking direction of the liquid crystal panel 2 and the touch panel 1 is considered as the force component (and the electric field component).)
Fc = qc × Ec
Fd = qd × Ed
Note that Ec is the electric field strength at point c, and Ed is the electric field strength at point d.

Here, the electric field intensity Ec at the point c is obtained by the following equation. (Strictly speaking, the electric field strength includes electric field components due to the voltage of a signal applied to the pair of electrode layers of the touch panel 1 and the pixel electrode or segment electrode of the liquid crystal panel 2, but these cause noise. (Since there is almost no change at a certain frequency, it is omitted here.)
Ec = Ecomc (t) + Eqc + Eqd-Etpd (t)
Ecomc (t) is due to driving of the liquid crystal panel 2 (counter electrode layer 23) among electric field components at the point c and is a function of time, and Eqc is due to electric charge qc among electric field components at the point c. Eqd is due to the electric charge qd among the electric field components at the point c, and Etpc (t) is due to the voltage of the back surface side electrode layer 7 of the touch panel 1 among the electric field components at the point c. .

  Here, when no voltage is applied to the back surface side electrode layer 7 of the touch panel 1, Etpd becomes 0, so that the Ecomc (t) changes with the drive frequency component by the COM signal that changes with the drive frequency as in the prior art. , Fc also changes at this driving frequency, but in Example 1, since a voltage synchronized with the change in the voltage of the common electrode signal is applied to the back surface side electrode layer 13 of the touch panel 1, the point c Since the component in which the electric field strength Ec changes with time decreases, the change in Fc with time decreases. The level of the signal amplitude (AC voltage value) applied to the transparent electrode 5 of the touch panel 1 is determined based on the positional relationship among the back surface of the touch panel 1, the counter electrode layer 13, and the back surface side electrode layer 7 of the touch panel 1. It is also possible to eliminate the temporal change of the intensity Ec. This can be considered similarly for the force Fd acting on the charge at the point d.

  Since the same change in electric field strength occurs at other points on the back surface of the touch panel 1 (transparent plate material 5), if the total charge on the back surface of the touch panel 1 (transparent plate material 5) is Qtp, then Qtp That is, it is considered that the force Ftp acting on the entire surface is also unlikely to change, and similarly, when the total charge amount on the entire surface of the liquid crystal panel 2 is Qlc, the force Flc acting on the entire panel surface is also unlikely to change.

  As described above, since the temporal changes in the forces Ftp and Flc acting on the back surface of the touch panel 1 and the surface of the liquid crystal panel 2 can be reduced, the vibration of the space between the touch panel 1 and the liquid crystal panel 2 is eliminated. The phenomenon of sounding can be avoided.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. That is, embodiments obtained by combining technical means appropriately changed within the scope of the claims are also included in the technical scope of the present invention.

  The touch panel mechanism and the display device of the present invention can be used for a liquid crystal display device, and can be particularly preferably used for a mobile phone, a liquid crystal television, a PDA, and the like.

It is a block diagram which shows the display apparatus of embodiment of this invention. It is sectional drawing which shows the structure of the touch panel and liquid crystal panel which are shown in FIG. (A) is a signal waveform diagram showing a VCOM signal, and (b) is a signal waveform diagram showing a position detection signal. (A) is a pulse waveform diagram showing a conventional position detection signal as a comparative example, and (b) is a pulse waveform diagram showing a position detection signal of the present invention. It is a block which shows the display apparatus as a reference example. It is a figure for demonstrating the sound improvement theory of this invention. It is a figure for demonstrating generation | occurrence | production of a sound.

Explanation of symbols

1 Touch panel 2 Liquid crystal panel (display panel)
3 Signal generator 4 Touch panel controller (control unit)
8 First electrode layer (electrode layer)
9 Second electrode layer (electrode layer)
13 Counter electrode layer (common electrode layer)

Claims (4)

A display panel having a common electrode layer to which a voltage signal changing at a predetermined frequency is applied, a touch panel having a pair of electrode layers arranged at a predetermined interval and facing each other, and a position touched by a user on the touch panel is detected. In a touch panel mechanism comprising a control unit,
A touch panel mechanism, wherein a position detection signal that is input from the control unit to the touch panel and fed back to the control unit is a signal that is in phase and synchronized with the voltage signal.   2. A display device comprising the touch panel mechanism according to claim 1, further comprising a display panel.   The display device according to claim 2, wherein a position touched by a user on the touch panel is detected by contacting the set of electrode layers with each other.   The display device according to claim 2, further comprising a signal generation unit configured to generate the voltage signal.

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