JP2009064074A - Input unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an input unit for precisely detecting coordinates positions even in darkness, suppressing an increase in power consumption, and allowing a user to easily confirm contact input. <P>SOLUTION: The input unit comprises: photosensors that are arranged in a matrix in a display region of an image display panel and detect light entering from the front of the image display panel; and a position detection section for detecting a contact position of an indicator in contact with a display region from the output of the photosensor. The input unit further comprises: a contact detection section for detecting the contact betwen the indicator and an image display panel; and a display mode change means for changing the display mode of the image display panel to a second display mode in which the quantity of display light differs from that of a previous first display mode immediately after detecting the contact by the contact detection section. The position detection section detects a contact position from the output of the photosensor outputted during a period displayed in the second display mode. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an input device capable of detecting a touched coordinate position by touching a screen displayed on a display device with a finger or the like.

  As an input device that can detect an input coordinate position in contact with an input screen displayed by the image display device, a method of attaching a pressure detection device made of a transparent member on the surface of the image display device, There is a method in which a light projecting element and a light receiving element are arranged around the image display device, and coordinates are detected by a position where light from the light projecting element to the light receiving element is blocked. On the other hand, in order to further improve the display quality and reduce the size of the device, optical sensors are arranged in a matrix on the image display device, and contact is made from the light intensity distribution when an indicator such as a pen comes into contact. An input device for detecting the coordinate position has also been devised. In an input device in which optical sensors are arranged in a matrix, there is a method using a pen incorporating a light emitting element as an indicator, but a method capable of detecting a position without adding a special device to the outside has been devised.

  For example, Patent Document 1 discloses an input device in which non-visible light emitting elements and light receiving elements are arranged in a matrix on an image display device. A liquid crystal element or an EL (electroluminescence) element is used as the light emitting element. When an indicator such as a finger touches the screen, the light from the light emitting element is reflected by the indicator and received by the light receiving element, so that the contact position is detected.

JP 2006-301864 A

  In Patent Document 1, since the position where the light-emitting elements and the light-receiving elements that are invisible light are arranged in a matrix and contact with the image display device is detected, the coordinate position can be detected even when the surrounding brightness is dark. . However, there is a problem that power consumption increases because detection light needs to be constantly output from the light emitting element in order to detect contact. In addition, when the user inputs coordinates with a finger or a pen, the user cannot easily check whether the input device has detected contact.

  Therefore, the present invention has been made to solve the above-described problems, and can detect the coordinate position accurately even when the surrounding brightness is dark, suppresses an increase in power consumption, and further It is an object of the present invention to provide an input device that allows a user to easily confirm that a contact is input.

  An input device according to the present invention includes an optical sensor that detects light incident from the front surface of an image display panel arranged in a matrix in the display area of the image display panel, and an output of the optical sensor that indicates a contact position of an indicator that has contacted the display area. An input device including a position detection unit that detects from a contact detection unit that detects that an indicator has touched the image display panel, and a display on the image display panel immediately after contact is detected by the contact detection unit Display mode changing means for changing the mode to a second display mode having a different display light amount from the immediately preceding first display mode, wherein the display light amount in the second display mode is larger than the display light amount in the first display mode The position detection unit detects the contact position from the output of the optical sensor output during the period displayed in the second display mode.

  The liquid crystal display panel according to the present invention includes an optical sensor that detects light incident from the front surface of the image display panel arranged in a matrix in the display area of the image display panel, and an optical sensor that detects the contact position of the indicator that has contacted the display area. An input device including a position detection unit that detects from an output of the image display panel, a contact detection unit that detects that an indicator has contacted the image display panel, and an image display panel immediately after contact is detected by the contact detection unit Display mode changing means for changing the display mode to a second display mode having a different display light amount from the immediately preceding first display mode. The display light amount in the second display mode is made larger than the display light amount in the first display mode, and the position detection unit detects the contact position from the output of the optical sensor output during the period displayed in the second display mode. For this reason, even when the surroundings are dark, the amount of display light increases, so that the contact position of the indicator can be detected using the light. Further, the increase in light used for detection is only during the period of display in the second display mode, and an increase in power consumption can be suppressed. Furthermore, since the amount of display light changes immediately after contact, the user can easily confirm that the indicator has touched.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected about the same component and it abbreviate | omits without repeating the description.

Embodiment 1 FIG.
FIG. 1 is a perspective view showing the overall configuration of the input device according to the first embodiment of the present invention. A liquid crystal display panel 1 in which a liquid crystal layer 11 is sandwiched between a transparent color filter substrate (hereinafter abbreviated as CF substrate) 14 and a transparent thin film transistor substrate (hereinafter abbreviated as TFT substrate) 17; The light source 5 which irradiates light from the back side of the display panel 1 toward the front side, and the touch panel 8 which is disposed on the front side surface of the liquid crystal display panel 1 and is configured using a transparent member.

  A signal based on the image data is input to the TFT substrate 17 of the liquid crystal display panel 1, and the transmittance of the liquid crystal of the pixels arranged in a matrix is controlled by the signal. Red, green and blue color filters are provided on the CF substrate 14 of each pixel. The light from the light source 5 arranged on the back side is emitted to the front side while the transmittance and color are controlled by each pixel. The image based on the image data is displayed in the display area 55 as described above.

  Further, as will be described later, the liquid crystal display panel 1 includes a plurality of optical sensors arranged in a matrix in the display area 55 of the TFT substrate 14. This optical sensor receives light incident from the front side of the display panel. Therefore, when the liquid crystal display panel 1 is used, the light intensity distribution in the display region 55 can be detected from the signal intensity of the optical sensor. Furthermore, an indicator such as a pen or a finger that is in contact with the liquid crystal display panel 1 can be detected by the intensity distribution.

  Although the photosensor is fabricated on the TFT substrate 17, if the light intensity distribution in the display region 55 can be detected, for example, the photosensor is arranged in a matrix on another substrate and bonded to the liquid crystal display panel 1. You may produce by the method.

  As the touch panel 8, what is generally known as a resistive film type touch panel is used. In this structure, a spacer made of a flexible transparent resin or the like is sandwiched between two transparent electrodes, and the electrical resistance between the electrodes is output. When a pen or a finger comes into contact with the transparent electrode on the surface side, the spacer is deformed by the pressure and approaches or comes into contact with the transparent electrode on the back side. As a result, the electrical resistance between the two transparent electrodes changes, so that contact can be detected. The transparent electrode is formed so as to cover the entire display area 55 so that the contact can be detected no matter where the display area 55 is touched. Instead of the resistive touch panel, a capacitive touch panel that detects contact based on a change in electrostatic capacity between two transparent electrodes may be used. Further, for example, a device that has a transparent grid electrode on the surface and detects a contact by detecting a change in resistance between the grid electrodes may be used.

  The liquid crystal display panel 1 is connected to the display panel control unit 51. The display panel controller 51 outputs a drive signal to the liquid crystal display panel 1 based on the screen data to be displayed input to the input terminal 52 and the liquid crystal display according to the output signal of the optical sensor of the liquid crystal display panel 1. A detection unit that detects a contact position of the indicator that has contacted the front side of the panel 1 and outputs a position signal from the output terminal 60;

  The light source 5 is connected to the light source control unit 54, and the amount of emitted light is adjusted. The light source control unit 54 is connected to the display panel control unit 51 and performs control such as blinking of the light source 5 in accordance with the output of the image signal from the display panel control unit 51. The light source 5 is a surface light source that illuminates the entire display region from the back surface with substantially the same light density. A light guide plate having a lamp at the end can be used. The light source 5 may be divided into a plurality of areas with respect to the screen area, and each area may be repeatedly turned on and off sequentially within one frame period. In normal screen display, it is desirable that the light density be uniform in the plane when averaged over one frame period.

  The touch panel 8 is connected to the display mode control unit 3. The display mode control unit 3 detects contact from a change in resistance output from the touch panel 8. A timer 59 is connected to the display mode control unit 3. For example, the timer 59 is set to time zero when the display mode control unit 3 detects contact, and outputs a signal to the display mode control unit 3 when the time reaches a predetermined value. The display mode control unit 3 is connected to the display panel control unit 51 and the light source control unit 54, respectively. When it is detected that the touch panel 8 is touched while the image is displayed in the display area 55 in the input display mode in which the input screen is displayed, the display mode control unit 3 causes the liquid crystal display panel 1 to display the detection display mode. Thus, a signal is output to the display panel control unit 51 and the light source control unit 54.

  Here, the display in the detection display mode is a display in which the amount of light emitted is larger than that in the input display mode, and the amount of light emitted to the front surface of the liquid crystal display panel 1 is increased. Further, the display is made uniform in density, for example, the whole is displayed in white. The position of the indicator that has touched the touch panel 8 during the display period of the detection display mode is detected by the optical sensor of the liquid crystal display panel 1. The display period in the detection display mode is set to, for example, about 0.5 seconds immediately after contact is detected. When the timer 59 reaches the set time, a signal is output to the display mode control unit 3. When this signal is input, the display mode control unit 3 reduces the amount of display light on the screen, and again sets the display light amount to be equal to that of the normal input display mode, and the density is the same as in the input display mode. The display period in the detection display mode may be continued until contact is lost after detecting contact, or may be continued for a certain period of time, for example, 0.2 to 1 second after contact is lost.

  FIG. 2 is a front view showing the configuration of the input device according to the first embodiment of the present invention, for explaining the configuration of the liquid crystal display panel 1 and the display panel control unit 51. In the figure, pixels of 5 rows and 5 columns are arranged in the display area 55 for the sake of simplicity, but in reality, a larger number of rows and columns are arranged so that a complicated pattern can be displayed. Further, the liquid crystal display panel 1 of this figure shows the configuration of elements on the TFT substrate 17. Each pixel has a light detection sensor unit Sij (ij = 11,..., 15,... 55) and a liquid crystal drive unit Tij (ij = 11,..., 15,.

  The display panel control unit 51 includes a drive unit including an image data processing unit 56, a drive signal output unit 58, and a scanning signal output unit 57, and a detection unit 65 that detects a contact position using an optical sensor. The drive signal output unit 58 and the scanning signal output unit 57 may be formed on the TFT substrate 17 of the liquid crystal display panel 1. The image data input to the input terminal 52 of the display panel control unit 51 is subjected to signal processing by the image data processing unit 56 so that the image is optimally displayed on the liquid crystal display panel 1, and the processed signal is driven. A signal related to the display timing of the image frame is transmitted to the signal output unit 58 and to the scanning signal output unit 57. For each pixel row arranged in the row direction, the scanning signal output unit 57 is connected to the scanning signal lines Q1,. Further, drive signal lines P1,... P5 are connected from the drive signal output unit 58 to each pixel column arranged in the column direction. The scanning signal output unit 57 sequentially outputs signals to the scanning signal lines Q1,... Q5 within one frame period. When the switch in the liquid crystal drive unit Tij is turned on by the signal of the scanning signal line, the potential in the electrode in the liquid crystal drive unit Tij is given from the drive signal output unit 58 through the drive signals P1,. As a result, a potential suitable for an image to be displayed is applied to the electrodes in the liquid crystal driving unit Tij of each pixel arranged in a matrix.

  Further, the scanning signal output unit 57 connects the scanning signal lines Q1,... Q5 and the sensor driving lines Y1,. Although not shown in the figure, the common line is also connected to the light detection sensor unit Sij of each pixel. Further, in the pixels arranged in the column direction, the photodetection sensor unit Sij is connected to the detection unit 65 through the photodetection lines X1,. When a switch in the photodetection sensor unit Sij of the pixels arranged in a specific row is turned on by the signal of the scanning signal line, a photodetection line in which a signal corresponding to the light intensity received by the photodetection sensor is connected in the column direction It is output to the detector 65 through X1,.

  As described above, a signal corresponding to the light intensity of each pixel arranged in a matrix is sequentially input to the detection unit 65 in one frame period. In the detection unit 65, the contact position of the indicator is detected in the display area 55 from the light intensity distribution, and the position is output from the output terminal 60.

  The contact position is detected as follows. When external light is sufficiently input from the front side of the liquid crystal display panel 1, when a part of the display area 55 is touched with an indicator such as a finger, the light detection sensor unit Sij below the contact part is touched. The amount of incident light decreases, and the value of the output signal changes, for example, to be smaller than that of the peripheral light detection sensor. Further, when the external light from the front side of the liquid crystal display panel 1 is not sufficient, the light from the light source 5 is emitted to the front side of the liquid crystal display panel 1, so that the light is reflected by the indicator and the contact portion. It is detected by the light detection sensor unit Sij located below. Therefore, when the external light is not enough, the light detection sensor unit Sij below the contact portion increases the light amount, and the output signal changes, for example, to be larger than the peripheral portion. Usually, the contact portion is sufficiently small compared to the display area, so if the intensity of the optical signal in a specific small portion is sufficiently large or sufficiently small compared to the peripheral portion of the portion, it is determined that the portion is the contact position. it can. Therefore, the detection unit 3 detects the position where the light intensity in the pixel region 55 is the maximum and the position where the light intensity is the minimum, and determines whether the light intensity at the position is equal to or higher than a predetermined ratio with the light intensity in the peripheral part. Judgment is made and the position where the ratio becomes the largest is outputted as the contact position.

  FIG. 3 is a circuit diagram showing a configuration in a pixel of the liquid crystal display panel of the input device according to the first embodiment of the present invention. In the pixel Gij, there are a light detection sensor unit Sij and a liquid crystal driving unit Tij connected to the scanning signal line Qi and the common line Zi. The light detection sensor unit Sij is further connected to the sensor drive line Yi, and outputs an output signal to the light detection line Xj. The liquid crystal driver Tij is connected to the drive signal line Pj and supplied with the potential of the electrode.

  In the photodetection sensor unit Sij, one end of the photosensor element S is connected to the sensor drive line Yi, and the other end is connected to one end of the reference resistor R. The other end of the reference resistor R is connected to the common line Zi. The other end of the photosensor element S is connected to the gate electrode of the detection transistor T1. The source electrode of the detection transistor T1 is connected to the common line Zi, and the drain electrode is connected to the source electrode of the selection transistor T2. The gate electrode of the selection transistor T2 is connected to the scanning signal line Qi, and the drain electrode is connected to the light detection line Xj.

  As the optical sensor element S, an element whose resistance changes with the intensity of light is used. This element is, for example, a silicon photodiode formed of thin film silicon. This can be easily manufactured by forming the TFT substrate at the same time as the transistor. When amorphous silicon is used as the thin film silicon, an optical sensor having low sensitivity in the infrared region and high sensitivity to visible light can be obtained, and the contact position can be detected using display light. Further, by forming on the light shielding film of the TFT substrate, light from the light source on the back surface is shielded, and light incident from the front side of the display panel is received. Further, the optical sensor element S may be a bolometer whose resistance changes as the temperature rises due to light irradiation.

  A sensor drive voltage is applied between the sensor drive line Yi and the common line Zi. The potential between the optical sensor element S and the reference resistor R connected in series between the sensor drive line Yi and the common line Zi varies depending on the light intensity. Since the potential is applied to the gate electrode of the detection transistor Ti, the current flowing through the detection transistor Ti is determined by the light intensity. If a predetermined voltage difference is set between the common line Zi and the light detection line Xj, the selection transistor T2 is turned on according to the signal from the scanning signal line Qi, and the current of the detection transistor Ti is detected by light. Flows to line Xj. As described above, a signal indicating the light intensity of the pixel Gij connected to the scanning signal line Qi and the light detection line Xj is output to the detection unit 65.

  In the liquid crystal drive unit Tij, there are an electrode E1 and an electrode E2 that are located with a liquid crystal interposed therebetween. E1 is connected to the drive signal line Pj via the selection transistor TD, and the electrode E2 is connected to the common line Zi. In addition, the storage capacitor CS is connected to the drive signal line Pj and the common line Zi via the selection transistor TD. The gate electrode of the selection transistor TD is connected to the scanning signal line Qi. When a signal is applied to the scanning signal line Qi, the electrode E1 is applied with a potential from the drive signal line Pj. The potential of the common line Zi is applied to the electrode E2. The optical characteristics of the liquid crystal change based on the potential difference between the electrode E1 and the electrode E2, and the transmittance of the pixel changes. When there is no signal in the scanning signal line Qi, the drive signal line Pj and the electrode E1 are not connected, but the applied potential is held by the holding capacitor CS until a signal is supplied to the scanning signal line Qi in the next frame. The electrode E2 is configured to be connected to the common line Zi in the pixel Gij, but the electrode E2 is configured as a transparent electrode formed on the entire CF substrate 14 side so that a common potential is applied to the transparent electrode. Also good.

  In a liquid crystal display panel for color display, a color filter and a black matrix surrounding the color filter are formed on the CF substrate 14 for each pixel. The black matrix is formed so that elements such as TFTs on the TFT substrate 17 and wiring do not reflect light to the front side of the display panel. The optical sensor element S may be arranged so that an opening is provided in the black matrix of the CF substrate 14 facing the light sensor element so that light incident from the opening can be received.

  Next, the operation of the input device according to the first embodiment of the present invention will be specifically described. FIG. 4 is a schematic diagram showing an operation on the display screen of the input device according to the first embodiment of the present invention. The input device according to Embodiment 1 has a pause display mode in addition to the input display mode and the detection display mode described above. The pause display mode is a display mode in which the light source 5 is turned off or dimmed to reduce power consumption when the operation is not performed for a long period of time. FIG. 4A shows the screen of the display area 55 in the pause display mode, where the light source 5 is turned off or dimmed and the entire screen is dark. FIG. 4B is a diagram in which the indicator 70 is in contact with the surface of the display area 55 in the pause display mode. Immediately thereafter, the light source 5 is turned on or brightened to change from the pause display mode to the input display mode, and the display shown in FIG. Here, the input display mode shown in FIG. 4C shows a state where there is a reference area 72 in the upper half of the screen and an input area 71 in the lower half of the screen. Based on the graphic and character information displayed in the reference area 72, the user touches the indicator 70 at the selected position displayed in the input area 71. FIG. 4D is a diagram in which the indicator 70 is in contact with the selection position B in the input area 71. Immediately after this, as shown in FIG. 4E, the detection display mode is entered in which the input area 71 is bright and the entire shade is uniform. In the detection display mode, the input area 71 may be displayed in white, and not only the input area 72 but the entire display area 55 may be bright and the shading may be uniform. For example, when about 0.5 seconds elapse after the display of the detection display mode, the display of the input area 71 returns to the normal input display mode again as shown in FIG. At that time, the next input screen may be displayed according to the contact position, or the contact position and the display of the reference area 72 corresponding to the position may be changed. The display in the detection display mode is continued while being in contact with the indicator 70, and is changed to the display equivalent to the input display mode immediately after the indicator 70 is no longer in contact or after 1 second or less immediately thereafter. You may be made to do. If no contact is made for a certain period of time, the input display mode is changed to the pause display mode.

  FIG. 5 is a flowchart for explaining the operation on the display screen of the input device according to the first embodiment of the present invention. After the start of use, first, display is performed on the liquid crystal display panel 1 in the input display mode in step S101. In step S102, T1 is counted by the timer 59 and set to zero. Thereafter, in step S103, the display mode control unit 3 determines whether or not the output signal from the touch panel 8 indicates that there is a touch. If there is no contact, the process proceeds to step S109. If the time of the timer 59 is greater than T3, the process proceeds to step S110, the liquid crystal display panel 1 is set to the pause display mode, and then the process returns to the step of determining contact in step S103. If the time of the timer 59 is equal to or less than T3, the display mode remains unchanged and the process returns to the step of determining contact in step S103. That is, if there is no contact during time T3, the pause display mode is set.

  When contact is detected in step S103, the process proceeds to step S104, and the time of the timer 59 is set to zero again. In step S105, it is determined whether or not the display mode at that time is the pause display mode. If the display mode is the pause display mode, the process returns to the first step S101 to set the input display mode. If the display mode is not the pause display mode, the input display mode is set, and the detection display mode is set in step S106. In the subsequent step S107, the contact position is detected by the detection unit 65 of the display panel control unit 51 during the period displayed in the detection display mode. Thereafter, the position is output from the output terminal 60. In the subsequent step S108, the timer 59 outputs a signal after the time T2. Based on the signal, the display mode control unit 3 returns the display mode of the liquid crystal display panel 1 from the detection display mode to the input display mode. Note that the period necessary for detecting the contact position ≦ T2 <T3. The output from the output terminal 60 may be output after returning to the input display mode.

  Further, in the first embodiment of the present invention, the outputs of all the optical sensors in the display area 55 are output to the detection unit 65 every frame, so in one frame period of the liquid crystal display device, for example, 1/60 second The contact position can be detected from the detection signal. In order to improve detection accuracy, the contact position can also be detected using a signal of several frame periods. Even when the contact position can be detected by the signal output from the touch panel 8 during the period of one frame or several frames as described above, the time is longer than the period necessary for the detection, for example, several tens to several hundred frames. For example, it is preferable to display in the detection display mode for about 0.2 to 2 seconds. It is difficult for the user to notice that a contact has been detected if the display changes within a few frames, but by changing the display for a certain length of time, the user can be surely visually notified that contact has been detected. Can do.

  According to the above procedure, when the touch panel 8 is touched when the display mode is the pause display mode, the display mode returns to the input display mode. Thereafter, the input display mode is displayed at least for the time T1. If contact is made thereafter, the contact position is detected and output in the detection display mode. Since the pause display mode is incorporated in this way, power consumption can be reduced. Further, since the touch display 8 returns to the normal input display mode from the pause display mode, the input device is easy to use.

  In addition, when continuous coordinates on the display area 55 are input, the detection display mode may be changed to the input display mode after the contact of the indicator 70 is lost. Continuous coordinates can be input by scanning the display area 55 while the indicator 70 is in contact. The contact position detected for each frame within the scanning period is continuously output from the output terminal 60. When the input is completed, the indicator 70 is separated from the display panel. Therefore, the time point when the indicator 70 detects that the contact with the display panel is lost from the signal of the touch panel 8 is set as the input completion point. The detection display mode is changed to the input display mode after a predetermined time of 1 second or less immediately after or immediately after the completion of the input. Since the display is changed to the input display mode, the user can know that the input is completed. Further, the display mode may be changed by a control signal of a device that receives a signal from the output terminal 60.

  6A and 6B are cross-sectional views showing the operation of the liquid crystal display panel of the input device according to the first embodiment of the present invention. FIG. 6A is a cross-sectional view of the input display mode, and FIG. A cross-sectional view is shown. The light source 5 is provided with lamps 25 at both ends of the light guide plate 24. Further, one of the electrodes E2 of the liquid crystal pixel is a common electrode on the color filter.

  In the input display mode of FIG. 6 (a), the position to be touched by the indicator is displayed on the screen, so that it is displayed in a pattern having a specific shading. Therefore, the transmittance of each liquid crystal is adjusted so that the transmittance of the liquid crystal has a specific pattern in the plane.

  The display mode with a large amount of display light as shown in FIG. 6B can be realized by a method of increasing the transmittance of the pixels so as to increase the light transmitted through the liquid crystal. It can also be realized by a method of increasing the light output of the light source 5 by increasing the output of the lamp 25. In the detection display mode, the amount of light emitted from the front surface of the liquid crystal display panel 1 is increased by one or both of these methods. At the place where the indicator 70 is in contact with the surface of the touch panel 8, the emitted light 75 emitted from the front surface is reflected by the surface of the indicator 70 and travels toward the photosensor element S in the pixel. On the other hand, since no reflection occurs in the non-contact area, the light is emitted in the front direction, and the light detected without returning to the photosensor element S is weak. Accordingly, the resistance greatly changes in the optical sensor element S in the vicinity of the contacted pixel, and the contact position can be detected.

  Since it operates as described above, even if the periphery of the liquid crystal display panel 1 is a dark place, the amount of light to the front surface of the panel increases at the time of detecting the contact position, so that detection with good sensitivity is possible. Further, detection is possible even if the light receiving area of the photosensor element S in the pixel is reduced, and the area ratio of the liquid crystal drive unit Tij to the photodetection sensor unit Sij can be increased, so that display quality can be improved. In addition, the amount of light to the front of the panel increases in accordance with the period required for detection, and the amount of light is reduced during periods when it is not necessary, so that power consumption can be reduced. In particular, using a method in which the display light amount in the input display mode is different from the display light amount in the detection display mode by changing the transmittance of the pixel, the power required in the detection display mode is hardly increased and the light required for detection is increased. Can do.

  Further, since the display mode is changed at least for a certain period during the detection operation, it is possible to notify the user of the contact simultaneously with the detection operation. After that, the display mode returns to the original display mode, so that it can be notified that the input has been completed. In addition, by uniformizing the display pattern and shading during a certain period to be detected, the amount of light reflected by the surface of the indicator that is in contact is almost constant even at different locations. For this reason, the amount of light detected by the optical sensor S of each pixel of the contact portion is made constant, and the detection accuracy is improved.

  In the first embodiment, the display mode is changed using the display mode control unit 3 and the timer 59, but a signal of the touch panel 8 for detecting contact is input to the input terminal 52 of the display panel control unit 51. The image data connected to the device and input to the input terminal 52 of the display panel control unit 51 by the device based on a signal detected by the touch panel 8 may be changed to image data in the detection display mode.

Embodiment 2. FIG.
FIG. 7 is a perspective view showing the overall configuration of the input device according to the second embodiment of the present invention. The liquid crystal display panel 1 and the light source 5 are fixed to the upper plate 32 of the support base 30, and the upper plate 32 is configured to be biased and held by a spring 37 between the lower plate 33 of the support base 30. Is different from the first embodiment. Further, in place of the touch panel 8 installed in front of the liquid crystal display panel 1 in order to detect contact in the first embodiment, the pressure switch 9 is installed between the upper plate 32 and the lower plate 33 to detect contact. I did it. In addition, an external light detection unit 31 that detects the intensity of external light using a photodiode or the like is installed on the outer periphery of the display area 55, and the detection display mode is changed based on the amount of external light. .

  A signal indicating the intensity of external light detected by the external light detection unit 31 is input to the display mode control unit 3. When it is determined from the signal that ambient ambient light is less than or equal to the predetermined light amount, the display mode control unit 3 is in front of the liquid crystal display panel 1 for a certain period of time immediately after the pressure switch 9 detects contact, as in the first embodiment. The detection display mode is set so that the amount of emitted display light increases. When ambient ambient light is dark below a predetermined light level, the contact position is detected by reflection of the surface of the indicator 70 using the light from the light source 5, and therefore, from the signal of the optical sensor S arranged in the display area 55. The position with the highest light intensity is detected as the contact position.

  On the other hand, if it is determined from the signal from the external light detection unit 31 that the ambient external light is greater than the predetermined light amount, the display mode control unit 3 immediately after the pressure switch 9 detects contact, contrary to the first embodiment. The detection display mode is set so that the amount of display light emitted to the front surface of the liquid crystal display panel 1 is reduced for a certain period. When the ambient light is brighter than the predetermined light amount, the contact position is detected using external light. Therefore, the position where the light intensity is the smallest is detected from the signal of the optical sensor S arranged in the display area 55. Detect as.

  FIG. 8 is a sectional view showing the configuration of the input device according to the second embodiment of the present invention, and shows the arrangement of the liquid crystal display panel 1, the support base 30, and the pressure switch 9 shown in FIG. FIG. 8A shows a cross section when the indicator 70 is not in contact, and FIG. 8B shows a cross section when the indicator 70 is in contact. If there is no contact as in (a), the distance between the upper plate 32 and the lower plate 33 is held by the spring 37, and the pressure switch 9 is not pushed and no output signal is generated. As shown in (b), the indicator 70 comes into contact with the liquid crystal display panel 1 and the liquid crystal display panel 1 is further pushed into the lower plate 33, whereby the distance between the upper plate 32 and the lower plate 33 is reduced, and the pressure switch 9 is pushed between the two plates. To produce an output signal. The distance between the upper plate 32 and the lower plate 33 is about 3 mm at (a), about 1 mm at the time when the contact at (b) is detected. Since this output signal indicates that the indicator 70 has touched the liquid crystal display panel 1, it can be used instead of the signal of the touch panel 8 of the first embodiment. Compared with the case where the touch panel 8 is touched, a stroke to be pushed in is necessary, but it is possible to clearly notify the user that the user has touched the liquid crystal display panel 1 by the touch. Further, the repulsive force may increase as it is pushed in, or sound or vibration may be generated at the time of (b). Moreover, since it detects by pushing in this way, the erroneous input by having touched lightly accidentally can also be prevented.

  Further, the touch panel 8 of the first embodiment can be used instead of the pressure switch 9. In that case, the touch panel 8 shall detect with a pressure. Then, the strength of the spring 37 and the sensitivity of the touch panel 8 are adjusted so that a signal for detecting contact is output from the touch panel 8 when the amount of pressing becomes a predetermined amount or more.

  FIG. 9 is a front view and a sectional view showing a display mode of the input device according to the second embodiment of the present invention. 9A shows a screen display in the input display mode, and FIG. 9C is a cross-sectional view thereof. FIG. 9B shows a screen display in a detection display mode displayed when the surrounding is bright, and FIG. 9D is a cross-sectional view thereof. When it is detected that the indicator 70 pushes in the liquid crystal display panel 1 when the external light detected by the external light detection unit 31 is larger than a predetermined light amount, as shown in (b) and (d), the input is performed immediately thereafter. The detection display mode is set in which the display of the area 71 is darkened. Detection of the contact position of the indicator 70 is detected by the outside light 76 incident on the optical sensor E being blocked by the indicator 70. In this case, the light emitted from the light source 5 to the front side of the liquid crystal display panel 1 lowers the detection accuracy. Therefore, as shown in (b) and (d), in the detection display mode, the lamp 25 of the light source 5 is darkened or turned off, and the light quantity emitted to the front surface is reduced by reducing the transmittance of the liquid crystal. Therefore, the detection accuracy of the contact position is improved.

  In addition, when the surroundings are bright, the amount of light emitted to the front surface is reduced by the detection display mode for a predetermined period immediately after detection of contact, so that power consumption can be further reduced. Further, since the liquid crystal display panel 1 is urged and held by the support base 30, and the pressure sensor 9 detects that the liquid crystal display panel 1 has been pushed in, the user can recognize contact by touching the panel. Can do. Further, the screen display becomes dark for a certain period, so that the contact can be recognized visually. Instead of the pressure sensor 9, a sensor that detects a change in position may be used.

Embodiment 3 FIG.
FIG. 10 is a perspective view showing the overall configuration of the input device according to the third embodiment of the present invention. Instead of the liquid crystal display panel and the light source 5 of the first embodiment, an EL display panel 2 in which EL light emitting elements are arranged in a matrix in the display region 55 is used. The configuration in which the light detection sensor unit Sij is provided in the pixel is the same as that in the first embodiment, but there is an EL drive unit instead of the liquid crystal drive unit Tij.

  Also in this case, when the touch is detected by the touch panel 8 as in the first embodiment, the light amount of the EL element is increased for a certain period from immediately after that, or the detection display mode in which the display density and pattern are made uniform is set. Thereby, even if the surroundings are dark, the detection accuracy is improved, and the amount of light is increased only when detection is necessary, so that an increase in power consumption can be suppressed.

Embodiment 4 FIG.
FIG. 11 is a perspective view showing the overall configuration of the input device according to the fourth embodiment of the present invention. The second embodiment is different from the second embodiment in that an auxiliary light source 6 is arranged around the front side of the liquid crystal display panel 1. Further, the upper plate 32 and the lower plate 33 of the support base 30 are different in that one end is connected by a hinge 38. Further, the external light detection unit is omitted from the second embodiment. In the input device according to the third embodiment of the present invention, when the periphery is dark, the light from the auxiliary light source 6 is used to detect the contact position with a photosensor arranged in a matrix in the display area 55. Although the auxiliary light sources 6 are installed on both sides of the front surface of the panel in the figure, lamps installed at four corners may be used.

  The auxiliary light source 6 may be a front light that illuminates the display surface with a light guide plate or the like from the front side. However, when a front light is used, the matrix of photosensors is prepared separately from the display panel and is arranged in front of the front light. That is, in order from the front side, the matrix of optical sensors, the front light that illuminates the screen, and the display panel are arranged in this order.

  The auxiliary light source 6 is connected to a power source 19 that controls the amount of light and lighting thereof. Further, the power source 19 is connected to the display mode control unit 3. Lighting of the auxiliary light source 6 and the amount of light are controlled by a signal from the display mode control unit 3. When the pressure sensor 31 detects that the liquid crystal display panel 1 has been pushed in, the time required to detect the contact position by the optical sensors arranged in a matrix in the display area 55 based on the signal from the display mode control unit 3 The auxiliary light source 6 is turned on or its light quantity is increased, and thereafter, it is turned off or its light quantity is reduced.

  In the fourth embodiment, the contact position can be detected by the auxiliary light source 6 even when the surroundings are dark. The light emitted from the auxiliary light source 6 to the front surface of the display panel is received by an optical sensor arranged in the display area, but when the indicator comes into contact with the surface, a shadow is generated at that portion. Therefore, as in the contact position detection using external light, the position with the lowest light intensity is detected as the contact position. For this reason, in the detection display mode, the display light amount may be smaller than that in the input display mode.

  Although the transmissive panel is used as the liquid crystal display panel 1 in the fourth embodiment, the light source 5 on the back side may be omitted as a reflective liquid crystal display panel. In this case, the auxiliary light source 6 is used as a light source that brightens the display surface even when the periphery is dark. Even in that case, the accuracy of position detection is improved by increasing the amount of light of the auxiliary light source 6 in the detection display mode as compared with the input display mode. Further, in the detection display mode, if the input area is displayed dark and the display pattern of the area is made uniform and the density is made uniform, the detection accuracy is improved. Since the position is detected by blocking the light incident on the optical sensor from the auxiliary light source 6, the light reflected from the reflective display pixel to the front surface of the panel lowers the detection sensitivity. Therefore, in the detection display mode, the detection accuracy is improved by reducing the reflectance of the input area and reducing the amount of light reflected on the front surface of the display panel. Moreover, since the display mode changes during the period of the detection display mode, it is easy to confirm that the user has made contact input.

  In addition, the optical sensors arranged in a matrix in the display region 55 may be used as sensors that are sensitive to infrared light, and the light source that emits infrared light may be used as the auxiliary light source 6. In this case, the display change in visible light does not occur due to the auxiliary light source 6, but in the detection display mode, the display light amount is reduced as compared with the input display mode as described above, and the shade of the region is made uniform. The position detection accuracy is improved, and the user can be notified of the input.

  Moreover, you may provide an external light detection part similarly to Embodiment 2. FIG. Since the contact position can be detected only with outside light if the surroundings are bright, an increase in power consumption can be suppressed if the auxiliary light source 6 is not turned on when the outside light detecting unit detects outside light with a predetermined brightness. .

Embodiment 5 FIG.
FIG. 12 is a graph showing the change over time in the amount of display light of the input device according to the fifth embodiment of the present invention. The configuration of the input device is basically the same as that in the first embodiment, but the display light quantity is changed with time during the detection display mode. The period of the detection display mode has a period A in which the amount of light is larger than that in the input display mode (a) immediately before contact detection and a period B in which the amount of light is smaller than that in the input display mode (a). The contact position is detected from the output of the photosensor output at B. In order to obtain the detection signal, the period A and the period B may be one frame period, but may be alternately repeated a plurality of times as shown in the figure. The total detection display mode period including the period A and the period B is preferably set to, for example, 0.2 to 1 second so that the user can visually confirm. Thereafter, the display light amount is changed to obtain an input display mode (b) having a display light amount substantially equal to the input display mode (a).

  The contact position is detected by storing the light intensity distribution obtained from the signal output in the period A and the light intensity distribution obtained from the signal output in the period B in a memory, and calculating the difference between the positions. Calculate. When each of the period A and the period B has a plurality of frames, the intensity of the plurality of frames at each position is averaged, and then the difference between the positions is calculated. As a result, the position with the largest difference is detected as the contact position. By detecting the contact position in such a procedure, it is possible to reduce the influence of variations in dark current for each optical sensor, and the position detection accuracy is improved. Alternatively, the ratio of each position may be calculated, and the position with the largest ratio may be detected as the contact position. In this case, it is possible to reduce the influence of variations in sensitivity for each optical sensor, and the position detection accuracy is improved.

  Note that the period A and the period B are preferably uniform in the density of the display area for position detection. Specifically, the display area is white display in period A and black or gray display in period B. In the period B, the light amount is smaller than that in the input display mode (a), but basically the light amount may be smaller than that in the period A.

  As described above, the detection display mode period has the input display mode (a) immediately before the contact detection for at least a certain period as in the period A, so that the contact position can be detected well even when the surroundings are dark. .

  When the light source on the front surface of the display panel is used for detection as in the fourth embodiment, although not shown in the figure, the period C in which the light amount is smaller than the input display mode (a) and the input display mode (a). The contact position may be detected from the output of the optical sensor output during these periods C and D.

  Note that when the contact position is detected using a shadow of an indicator generated by strong external light, such as outdoors in the daytime, the difference in light distribution between these periods A and B or between periods C and D is small. . In this case, as in the second embodiment, an external light detection unit 31 that detects the intensity of external light is installed, and when the light intensity exceeds a certain level, the detection display mode is the input display mode (a ) Display with less light intensity than that of), and the light intensity is not changed during the display period of the detection display mode, and the touch position is detected from the average of the light intensity distribution output during the detection display mode period. Change the mode.

  Although the fifth embodiment is based on the first embodiment as a device configuration, the same detection display mode and detection method may be used by applying to other embodiments.

Embodiment 6 FIG.
FIG. 13 is a cross-sectional view showing a contact detection unit of the input device according to the sixth embodiment of the present invention. FIG. 13 is the same as the cross-sectional view of the liquid crystal display panel of the first embodiment, but the transparent electrode E2 formed on the CF substrate 14 is connected to the AC source 41, and the transparent electrode E2 is an impedance detection unit that detects a change in impedance. 10 is connected. In the fifth embodiment, instead of the touch panel 8 of the first embodiment, the impedance detection unit 10 detects a change in impedance to detect contact, and performs the same contact position detection as in the first embodiment.

  An AC source 41 is connected to the transparent electrode E2 of the liquid crystal display panel of Embodiment 6, and an AC signal of several tens to several hundreds Hz is applied. Since an AC signal is applied, a slight leakage current flows between the transparent electrode E2 and the ground electrode 21. When an indicator of a user's finger or pen having conductivity contacts the display panel, the transparent electrode E2 is close to the CF substrate 14 and slightly between the transparent electrode E2 and the indicator. Leakage current flows. The impedance detector 10 detects a change in impedance between the transparent electrode E2 and the ground electrode 21 caused by the contact of the indicator. By detecting this change, the contact of the indicator can be detected.

  Thus, since contact is detected using the transparent electrode E2 of a liquid crystal display panel, it is not necessary to add members, such as a touch panel, to the surface of a display panel, display quality improves and a structure also becomes simple.

  Further, although the sixth embodiment is based on the first embodiment as a device configuration, it may be applied to other embodiments using a liquid crystal display panel as a display panel.

  As described above, in the present invention, the optical sensor that detects light incident from the front surface of the image display panel that is arranged in a matrix in the display area of the image display panel, and the contact position of the indicator that is in contact with the display area are optical sensors. And a contact detection unit for detecting that the indicator has touched the image display panel. The contact detection unit includes a device that detects changes in pressure, capacitance, and electrical resistance generated when the indicator contacts the panel surface, and an element that detects the pushing of the display panel. Therefore, unlike the optical sensor, these contact detection units are detection means that can detect contact even when the peripheral part is dark or the screen display is dark. In addition, display mode changing means is provided for changing the display mode of the image display panel to a detection display mode having a different display light amount from the previous input display mode immediately after contact is detected by the contact detection unit. The position detection unit detects the contact position from the output of the optical sensor output during the period displayed in the detection display mode. In the detection display mode, the amount of display light is increased so that the amount of light emitted to the front surface of the display panel increases compared to the input display mode immediately before contact. Therefore, in the transmissive liquid crystal display panel, the light amount of the light source on the back side is increased or the transmittance of the liquid crystal is increased. In particular, the latter method of increasing the transmittance is not necessary because the light source does not need to be controlled and the power consumption is hardly increased. Further, the reflectance is increased in the reflective liquid crystal display panel. In a display panel using a light emitting element such as an EL, the light amount of the light emitting element is increased. Since the optical sensor can detect the contact position using the light whose amount of light has been increased as described above, the detection of the contact position can be performed accurately even when the surroundings are dark. Further, the area ratio of the display portion in the pixel can be increased by reducing the size of the photosensor. Furthermore, when the amount of display light changes, the input device can detect contact and visually notify the user that input has started. In addition, a separate light source is not necessary, and the amount of light is not increased until contact is detected, so that an increase in power consumption can be prevented.

  In addition, when an illumination device that emits light from the front side of the display panel is provided and the contact position is detected by a shadow caused by contact of the indicator, immediately after the contact is detected by the contact detection unit by the display mode changing unit In addition, the light amount of the illumination device is increased, and the display mode of the display panel is changed to a detection display mode with a smaller display light amount than the previous input display mode. Since the display light illuminates the indicator, it has an action contrary to the fact that the indicator is shaded by the light incident from the front side. For this reason, in the detection of the contact position using the irradiation device on the front side or outside light, the amount of display light is reduced, so that accurate position detection can be performed. Moreover, a contact can be notified by the change of the light quantity. Further, since the lighting device is turned off or dimmed until contact is detected, an increase in power consumption can be suppressed. Moreover, since the light quantity of an illuminating device is reduced after a contact position detection, the increase in power consumption can be suppressed.

  In addition, an external light detection unit that detects the amount of external light is provided, and when the external light is below a certain light amount, the display light amount in the detection display mode is greater than the display light amount in the input display mode, When the amount of light is greater than a certain amount, the amount of light is made smaller than the display light amount in the input display mode. For this reason, even when the light sensor uses light emitted from the back side of the display panel to the front side or when external light incident from the front side is used, the detection accuracy of the contact position can be improved.

  Further, when the contact input is completed, the light amount in the detection display mode is returned to the display light amount in the input display mode immediately before the contact, so that the user can visually know that the input has been completed.

  In the detection display mode, as compared with the input display mode, the density of the input area in contact with the indicator, the area including the periphery thereof, or the entire display area is reduced. Since the display light of the display panel affects the detection of the contact position as described above, if a part where a character or picture is displayed is touched, the position detection is affected by the shade of the part, and thus erroneous detection is likely to occur. . False detection can be prevented by reducing shading. If the shading is uniform, the amount of light in the region is more constant regardless of the location. To make it uniform, the area is displayed in white display, black display, or gray display. When the entire screen is displayed in black, white, or the like, it can be realized with a simple configuration by providing a switch for blocking the image data input to the input terminal 52. In addition, the shading can be reduced by a process in which the image data processing unit 56 makes the data of each pixel constant.

  Further, the display light amount may be temporally changed during the period of display in the detection display mode. At least the period displayed in the detection display mode includes a period larger or smaller than the display light amount in the input display mode, and if the light detected by the photosensor is used during that period, the same effect as described above can be obtained. . Also, the difference or ratio of the light quantity at each optical sensor position is calculated from the distribution of the light quantity detected during the period when the light quantity is larger or smaller than the display light quantity in the input display mode and the distribution of the light quantity detected during the period when the light quantity is changed. Then, the contact position may be detected. By doing so, it is possible to cancel the variation in sensitivity among the optical sensors, and the detection accuracy of the contact position is improved.

  Further, a transflective liquid crystal display panel may be used instead of the transmissive or reflective liquid crystal display panel described above. Moreover, it is good also as a structure which combined each of the structure of the display panel described in said embodiment, the structure of a contact detection part, and the aspect of a detection display mode in the range which is not contrary to the objective of this invention. In the above embodiment, the period displayed in the detection display mode is set to, for example, 0.2 seconds or longer so that the user can easily recognize the contact. However, the period may be further shortened. For example, even if the display period in the detection display mode is one frame period, it is possible to make the user recognize the contact if the change in the amount of light displayed is sufficiently large, and the contact position can be detected accurately when the surroundings are dark. can do.

1 is a perspective view showing an overall configuration of an input device according to a first embodiment of the present invention. It is a front view which shows the structure of the input device of Embodiment 1 of this invention. It is a circuit diagram which shows the structure in the pixel of the liquid crystal display panel of the input device of Embodiment 1 of this invention. It is a schematic diagram which shows operation | movement on the display screen of the input device of Embodiment 1 of this invention. It is a flowchart explaining operation | movement on the display screen of the input device of Embodiment 1 of this invention. It is sectional drawing which shows operation | movement of the liquid crystal display panel of the input device of Embodiment 1 of this invention. It is a perspective view which shows the whole structure of the input device of Embodiment 2 of this invention. It is sectional drawing which shows the structure of the input device of Embodiment 2 of this invention. It is the front view and sectional drawing which show the display mode of the input device of Embodiment 2 of this invention. It is a perspective view which shows the whole structure of the input device of Embodiment 3 of this invention. It is a perspective view which shows the whole structure of the input device of Embodiment 4 of this invention. It is a graph which shows the time change of the display light quantity of the input device of Embodiment 5 of this invention. It is sectional drawing which shows the contact detection part of the input device of Embodiment 6 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal display panel, 2 EL display panel, 3 Display mode control part, 5 Light source, 6 Auxiliary light source, 8 Touch panel, 9 Pressure switch, 10 Impedance detection part, 11 Liquid crystal layer, 14 CF board, 17 TFT board, 19 Power supply 21 ground electrode, 24 light guide plate, 25 lamp, 30 support base, 31 external light detection unit, 32 upper plate, 33 lower plate, 37 spring, 38 hinge, 41 AC source, 51 display panel control unit, 52 input terminal, 54 Light source control unit, 55 display region, 56 image data processing unit, 57 scanning signal output unit, 58 drive signal output unit, 59 timer, 60 output terminal, 65 detection unit, 70 indicator, 71 input region, 72 reference region, 75 Emitted light, 76 External light, Pj, P1,... P5 Drive signal line, Qi, Q1,... Q5 Scanning signal line, Xj, X ..X5 light detection line, Yi, Y1, ..Y5 sensor drive line, Zi, Z1, ..Z5 common line, E1, E2 electrode, CS holding capacitor, Gij pixel, Sij light detection sensor part, Tij liquid crystal drive part, S Photosensor element, R reference resistance, T1 detection transistor, T2, TD selection transistor

Claims (10)

An optical sensor arranged in a matrix in the display area of the image display panel for detecting light incident from the front surface of the image display panel, and a position for detecting the contact position of the indicator that has contacted the display area from the output of the optical sensor An input device including a detection unit,
A contact detection unit for detecting that the indicator is in contact with the image display panel;
Display mode changing means for changing the display mode of the image display panel to a second display mode different in display light amount from the immediately preceding first display mode immediately after contact is detected by the contact detector;
The amount of display light in the second display mode is greater than the amount of display light in the first display mode,
The input device, wherein the position detection unit detects a contact position from an output of the optical sensor output in a period displayed in the second display mode. An optical sensor arranged in a matrix in the display area of the image display panel for detecting light incident from the front surface of the image display panel, and a position for detecting the contact position of the indicator that has contacted the display area from the output of the optical sensor An input device including a detection unit,
An illumination device for irradiating light on the front surface of the image display panel;
A contact detection unit for detecting that the indicator is in contact with the image display panel;
Display mode changing means for changing the display mode of the image display panel to a second display mode having a different display light amount from the immediately preceding first display mode immediately after contact is detected by the contact detector;
Illumination control means for increasing the irradiation amount of the illumination device immediately after contact is detected by the contact detection unit,
The amount of display light in the second display mode is less than the amount of display light in the first display mode,
The position detection unit detects a contact position from an output of the photosensor output in a period displayed in the second display mode;
The input device, wherein the irradiation amount of the illumination device is reduced after the position detection unit detects the contact position. An optical sensor arranged in a matrix in the display area of the image display panel for detecting light incident from the front surface of the image display panel, and a position for detecting the contact position of the indicator that has contacted the display area from the output of the optical sensor An input device including a detection unit,
A contact detection unit for detecting that the indicator is in contact with the image display panel;
An external light detection unit for detecting the amount of external light around the image display panel;
Display mode changing means for changing the display mode of the image display panel to a second display mode different in display light amount from the immediately preceding first display mode immediately after contact is detected by the contact detector;
The amount of display light in the second display mode is greater than the amount of display light in the input display mode when the external light detected by the external light detection unit is less than or equal to the predetermined light amount, and the external light is greater than the predetermined light amount Less than the amount of light displayed in the first display mode,
The input device, wherein the position detection unit detects a contact position from an output of the photosensor output in a period displayed in the detection display mode. 4. The input according to claim 1, wherein after the position detection unit detects the contact position, the display light amount of the image display panel is changed to a display light amount equivalent to the first display mode. 5. apparatus. The image display panel is a transmissive liquid crystal display panel, and the display light amount in the first display mode and the display light amount in the second display mode differ depending on the transmittance of the liquid crystal. The input device described. The input device according to claim 1, wherein the display area is uniform in light and shade in the second display mode. The position of the optical sensor output in the first period and the second period, the first period and the second period having different display light amounts in the period displayed in the second display mode. The input device according to claim 1, wherein a contact position is detected from the input device. The input device according to claim 1, wherein the contact detection unit includes a touch panel installed on the surface of the image display panel. 9. The input according to claim 1, wherein the image display panel is urged and held by a support base, and the contact detection unit includes an element for detecting that the image display panel is pushed. apparatus. The image display panel is a liquid crystal display panel having a transparent conductive film to which an AC signal is applied, and the contact detection unit has a detection unit for detecting a change in impedance of the transparent conductive film. The input device according to any one of the above.

Images