JP2005165428A - Coordinate input device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely detect coordinates even when any object other than an instructed member exists on a screen without deteriorating the visibility of a display image even when this coordinate input device is applied to a particle movement/rotation type image display device. <P>SOLUTION: This coordinate input device is provided with a line coordinate signal driving circuit 116 for applying a signal showing line coordinates to one electrode of an image display device for controlling voltage between a pair of electrodes configuring pixels forming a screen to control the color of the pixels, a column coordinate signal driving circuit 117 for applying a signal expressing column coordinates to the other electrode, an electric field detecting device 120 for detecting a pointed position on the screen or the change of its surrounding electric field and a coordinate discrimination circuit 121 for retrieving coordinates based on the detection result of the electric field detection device 120. Also, this coordinate input device is provided with a magnetic field detection device 401 for detecting the pointed position on the screen or its neighboring magnetic field instead of the electric field detection device 120 and the coordinate discrimination circuit 121, and a coordinate discrimination circuit 402 for retrieving the coordinates based on the change detected by the magnetic field detection device 401. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a coordinate input device (digitizer) that detects and inputs coordinates of a designated position on a screen of an image display device.

  Patent Document 1 discloses a particle movement type image display device. This image display apparatus has a configuration in which two types of particles having different colors and charging polarities are enclosed between a pair of substrates, and the voltage between these substrates is controlled for each pixel. One substrate is transparent, and particles adhering to the substrate can be seen through when viewed from the substrate side. When attention is paid to one pixel, the color of particles adhering to one substrate in this pixel becomes the color of this pixel. In the case of changing the color of a pixel, a voltage is applied to the pixel so that particles to be moved are moved between a pair of substrates to a substrate opposite to the substrate to which the particles are attached. Thereby, in this pixel, particles move between a pair of substrates, and particles attached to one substrate are replaced.

  Patent Document 2 discloses a particle rotation type image display device. This image display device has a configuration in which spherical particles having different colors and charged states are supported between two hemispheres so as to be rotatable between a pair of substrates, and a voltage between these substrates is controlled for each pixel. . One substrate is transparent, and when viewed from the substrate side, the color of the hemispherical surface facing the substrate can be seen through the spherical surface of the particles. When attention is paid to one pixel, the color of the hemispherical surface facing one substrate among the spherical surfaces of particles in this pixel is the color of this pixel. When the color of the pixel is changed, a voltage is applied to the pixel so that particles to be rotated rotate between the pair of substrates. Thereby, in this pixel, the particles rotate and the hemispherical surface facing one substrate is replaced.

  When detecting the coordinates of the position indicated on the screen of the above-described particle movement / rotation type image display device, an existing coordinate input device is used. As an existing coordinate input device, there is a coordinate input device that detects coordinates using an optical system disclosed in Patent Document 3, and a coordinate input device that detects coordinates using a touch panel disclosed in Patent Document 4.

  FIG. 23 is a top view illustrating a configuration example of a coordinate input device that detects coordinates using an optical system, and FIG. 24 is a cross-sectional view taken along line AA ′ of FIG. The coordinate input device shown in this figure has a large number of light emitting elements 802 along two adjacent sides of a screen 801 of the image display device, and a light beam irradiated by these light emitting elements 802 is provided along opposing sides. When the light beam covers the screen 801 of the image display device in a sheet shape by being sent out toward the light receiving element array 803, and the light beam is blocked by the pointing member 804 such as a pen that indicates the position on the screen, Two light shielding directions are obtained based on the light intensity sensed by the element array 803, and the coordinates of the intersection of both directions are calculated. With this coordinate input device, even if the applied image display device is a particle movement / rotation type image display device in which colored particles are moved or rotated to form an image, an instruction on the screen is given. The coordinates of the position can be detected.

  If such a coordinate input device is applied to the above-described particle movement / rotation type image display device, it is possible to detect and input the coordinates of the position indicated on the screen. However, if an object (for example, a memo paper) that is not the pointing member 804 is present on the screen of the image display device, the optical path is blocked by the object that is not the pointing member 804, and the coordinates of the pointed position are detected using the pointing member 804. It becomes difficult.

  FIG. 25 is a cross-sectional view illustrating a configuration example of a coordinate input device that detects coordinates using a touch panel. This coordinate input device is applied to an image display device using liquid crystal, and this figure shows a cross section in the thickness direction of the image display device. In this figure, a liquid crystal cell 812 and a reflector 811 provided on the back side of the liquid crystal cell 812 constitute an image display device, and are stacked in order on the front side (image display side) of the liquid crystal cell 812. The two-wavelength plate 813, the transparent conductive film 814, the spacer 815, the transparent conductive film 816, the quarter-wave plate 817, and the polarizing plate 818 constitute a coordinate input device. In this coordinate input device, when the polarizing plate 818 is pressed by an instruction unit such as a finger or a pen, and the transparent conductive film 814 and the transparent conductive film 816 come into contact with each other at the pressed position, the coordinate input device is pressed based on the potential at the contact position. Detect position coordinates.

If such a coordinate input device is applied to the particle movement / rotation type image display device described above, the coordinates of the position indicated on the screen can be detected and input. However, since it is necessary to form a plurality of layers on the screen of the image display device, the visibility of the display image is lowered.
JP 2002-82361 A JP 2001-242804 A JP 2002-116428 A JP 2001-31368 A

  The present invention has been made in view of the above-described circumstances. Even when applied to a particle movement / rotation type image display device, the present invention is not limited to an indication member on the screen without reducing the visibility of the display image. An object of the present invention is to provide a coordinate input device capable of reliably detecting coordinates even when there is an object.

  The present invention provides a coordinate signal representing the coordinates of the pixel to the electrode of the image display device that controls the color of the pixel by controlling the voltage between a pair of electrodes constituting the pixel that forms a screen on which an image is displayed. A coordinate signal driving circuit to be applied, a detection device used to indicate a position on the screen, and detecting a change in an electric field or a magnetic field at or near the specified position, and a change detected by the detection device There is provided a coordinate input device having a coordinate discrimination circuit for detecting the coordinates based thereon.

  The present invention also includes a substantially transparent transparent electrode provided substantially in parallel with the screen at the back of the screen on which an image is displayed, and an electrode provided substantially in parallel with the screen at the back of the transparent electrode. When driving the pixels forming the screen, the pixel driving signal corresponding to the driving contents of the pixel is applied to at least one of the transparent electrode and the electrode constituting the pixel to control the voltage between the electrodes. Accordingly, the particles having the color on the surface enclosed in the gap between the electrodes are moved or stationary between the electrodes, or the particles having a region for each color on the surface are rotated or stationary so that the pixels on the screen are displayed. A coordinate signal drive circuit for applying a coordinate signal representing the coordinates of the pixel constituted by the transparent electrode and the electrode to at least one of the transparent electrode and the electrode of the image display device for controlling the color of the image display device; A detection device that is used to indicate a position on the screen and detects a change in an electric field or a magnetic field at or near the indicated position, and a coordinate determination that detects the coordinates based on the change detected by the detection device A coordinate input device having a circuit is provided.

According to another aspect of the present invention, a coordinate signal driving circuit that outputs a coordinate signal representing coordinates of a pixel that forms a screen on which an image is displayed and a pixel driving signal are applied to a pair of electrodes that form the pixel that forms the screen. Accordingly, the pixel driving signal applied to the electrode of the image display device that controls the voltage of the pixel by controlling the voltage between the electrodes is output from the coordinate signal driving circuit for the pixel corresponding to the pixel driving signal. A signal superimposing circuit that modulates the modulated coordinate signal and applies the modulated signal to the electrode instead of the pixel drive signal;
A detection device for detecting a change in an electric field or a magnetic field at or near the indicated position, and a coordinate for detecting the coordinate based on the change detected by the detection device, which is used for indicating the position on the screen. A coordinate input device having a determination circuit is provided.

  In each of the coordinate input devices described above, the voltage between the pair of electrodes constituting the pixel and the potential of each electrode change according to a coordinate signal representing the coordinates of the pixel. As a result, the electric field or magnetic field in the space near the pixel changes. Such a change in electric or magnetic field extends to the airspace on the screen. If the position near the pixel on the screen is indicated using the detection device and the change in the electric field or magnetic field occurs while the detection device is in the airspace, the change is detected by the detection device. . Since the change detected by the detection device is a change according to the coordinate signal for the pixel, the coordinate determination circuit detects the coordinate of the pixel based on the detected change.

According to the present invention, even when applied to a particle movement / rotation type image display device, the coordinates of the indicated position on the screen can be displayed on the screen other than the indication member without reducing the visibility of the display image. Even if there is an object, it can be reliably detected.
In addition, according to the present invention, since the image display device applies a signal for coordinate detection to the electrode already provided for controlling the color of the pixel, compared to the case where a new electrode for coordinate detection is provided, The configuration of the coordinate input device can be simplified.
Moreover, in the aspect which modulates a pixel drive signal with a coordinate signal, since a coordinate signal and a pixel drive signal can be output in parallel, the scanning time interval of a screen can be shortened, for example.
In addition, if the timing at which the coordinate signal driving circuit outputs the coordinate signal and the length and waveform of the coordinate signal are appropriately determined, a change in the color of the pixel can be prevented from being caused by the use of the coordinate signal. .

  As an embodiment of the present invention, there are a form in which coordinates are obtained by detecting a change in electric field and a form in which coordinates are obtained by detecting a change in magnetic field. Below, 1st Embodiment-3rd Embodiment are mentioned as the former form, and 4th Embodiment-6th Embodiment is mentioned as the latter form. Hereinafter, the first to sixth embodiments will be described in order with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure.

[First Embodiment]
[Constitution]
FIG. 1 is a diagram showing a configuration of the coordinate input device according to the first embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a partial configuration of the coordinate input device. This coordinate input device is configured by effectively using the configuration of the applied image display device. Therefore, FIGS. 1 and 2 also show the configuration of the image display apparatus. In FIG. 2, for a person observing an image displayed by the image display device, the upper side in the figure corresponds to the front and the lower side corresponds to the back.

  An image display device to which the present coordinate input device is applied is a particle movement type image display device as disclosed in Patent Document 1. As shown in FIG. 1, in this image display device, when viewed from the viewing side, a plurality of transparent electrodes 101 extending in the row direction and a plurality of electrodes 102 extending in the column direction intersect in a matrix. It is configured. Pixels of the image display device exist at these intersections. The transparent electrode 101 is formed using substantially transparent ITO (Indium Tin Oxide).

  As shown in FIG. 2, the image forming portion of the image display device protects the electrode 102, the dielectric layer 104 for protecting the electrode 102, the rib 105, and the transparent electrode 101 on the substrate 103. For this purpose, a transparent dielectric layer 106, a transparent electrode 101, and a transparent glass substrate 107 are sequentially laminated. The rib 105 divides the gap between the dielectric layer 104 and the dielectric layer 106 for each pixel, and forms a cavity for each pixel. Each cavity is filled with a dry gas (for example, air or nitrogen), and positive black particles 108 and negative white particles 109 are enclosed. The positive black particles 108 and the negative white particles 109 are preferably spherical with a diameter of 5 to 50 μm. The positive black particles 108 have a positive polarity in charging polarity and a black color. The negative white particles 109 have a negative polarity in charging polarity and a white color. As these particles, toner particles are suitable.

  Since the color of the particles existing on the dielectric layer 106 side in the cavity is observed through the glass substrate 107, the transparent electrode 101, and the dielectric layer 106, it becomes the color of this pixel. For example, if a particle present on the dielectric layer 106 side in a certain pixel is a positive black particle 108, the color of the pixel is black, and if a negative white particle 109 is used, the color of the pixel is white. In addition, it can also be set as the structure which reversed the charge polarity with black particle | grains and white particle | grains, and reversed the positive / negative of the below-mentioned various electric potential. Moreover, when the contrast of the image displayed on a screen may be low, the color of positive polarity particle | grains and negative polarity particle | grains can also be made into arbitrary colors. However, the colors of the positive polarity particles and the negative polarity particles must be different from each other. The screen is a surface on which an image is displayed, and is formed by a plurality of pixels. The glass substrate 107, the transparent electrode 101, the dielectric layer 106, the dielectric layer 104, the electrode 102, and the substrate 103 are provided substantially parallel to this screen.

  As shown in FIGS. 1 and 2, the transparent electrode 101 is connected to a row electrode 110 for applying an electric signal to the transparent electrode 101, and the electrode 102 is connected to a column electrode 111 for applying an electric signal to the electrode 102. Has been. The correspondence between the transparent electrode 101 and the row electrode 110 and the correspondence between the electrode 102 and the column electrode 111 are one to one. Further, this image display device drives pixels by a simple matrix driving method, and as shown in FIG. 1, a row pixel drive circuit 112 that outputs a row pixel drive signal by changing the potential at the output end. The column pixel driving circuit 113 for outputting the column pixel driving signal by changing the potential of the output terminal, and the row electrode 110 to which the row pixel driving signal output from the row pixel driving circuit 112 is applied in order. A row signal scanning circuit 114 for switching and a column signal scanning circuit 115 for sequentially switching the column electrode 111 to which the column pixel driving signal output from the column pixel driving circuit 113 is applied.

  In this image display device, the voltage applied to the positive black particles 108 and the negative white particles 109 can be obtained by subtracting the potential of the electrode 102 from the potential of the transparent electrode 101. If this voltage is a negative value, the positive black particles 108 are drawn to the transparent electrode 101 (dielectric layer 106) side, and the negative white particles 109 are drawn to the electrode 102 side. Conversely, if this voltage is a positive value, the negative white particles 109 are attracted to the transparent electrode 101 side and the positive black particles 108 are attracted to the electrode 102 (dielectric layer 104) side. However, the particles do not start moving immediately upon being pulled. The particles start to move when the relationship between the voltage applied between the transparent electrode 101 and the electrode 102 and the application time becomes a predetermined relationship. The voltage at this time is called a movement start voltage, and the application time is called a movement start time.

  FIG. 3 is a diagram showing the relationship between the movement start voltage and the movement start time of the positive black particles 108 when the pixel color is changed from white to black in this image display device. As shown in this figure, when the movement start voltage is high, the movement start time is short, and when the movement start voltage is low, the movement start time is long. For example, when the movement start time is about 20 [ms], the movement start voltage is about −90 [V], and when the movement start time is about 30 [ms], the movement start voltage is about −75 [V]. is there. Further, no matter how high the movement start voltage is, the movement start time does not become zero, and no matter how long the movement start time is, the movement start voltage does not become zero or less.

  This image display device employs positive black particles 108 and negative white particles 109 in which the relationship between the movement start voltage (absolute value) and the movement start time is the same. Therefore, when the relationship between the voltage applied between the transparent electrode 101 and the electrode 102 and the application time satisfies the movement start condition determined from the relationship between the movement start voltage and the movement start time of the positive black particles 108, While the positive black particles 108 move, the negative white particles 109 move in the opposite direction to the positive black particles 108. Further, when the relationship between the voltage applied between the transparent electrode 101 and the electrode 102 and the application time does not satisfy the movement start condition, the positive black particles 108 and the negative white particles 109 do not start moving, Stay in your current position.

  In this image display device, in order to lower the absolute value of the movement start voltage (in order to shorten the movement start time), particles are adhered between the transparent electrode 101 and the electrode 102 for the pixel whose color is changed. After applying a voltage for attracting the particles to the dielectric layer, a voltage for moving the particles is applied to the dielectric layer opposite to the dielectric layer to which the particles are attached. Thus, by providing a step of applying a voltage that is opposite in polarity to the voltage for movement (hereinafter referred to as reverse voltage), the absolute value of the movement start voltage is reduced (movement start time is shortened). Since the relationship between the voltage applied in this step and the application time is determined so as not to satisfy the movement start condition, the positive black particles 108 and the negative white particles 109 move in this step. There is nothing. This image display device unifies the color of all pixels to white or black at the start of image display, and thereafter maintains or changes the color of each pixel when scanning the screen. At this time, since this image display device knows which particle is attached to which dielectric layer in each pixel prior to scanning, an appropriate voltage is applied between the transparent electrode 101 and the electrode 102. Can be applied.

  The row pixel driving circuit 112, the column pixel driving circuit 113, the row signal scanning circuit 114, and the column signal scanning circuit 115 scan the screen using the row pixel driving signal and the column pixel driving signal. In this scanning, among the row pixel drive signal and the column pixel drive signal, the time portion used for driving the pixel whose color is changed is the voltage between the transparent electrode 101 and the electrode 102, and the particles adhere to this pixel. A voltage that attracts the particles to the dielectric layer, and then a voltage that attracts the particles to the dielectric layer opposite to the dielectric layer to which the particles are attached. The signal between the transparent electrode 101 and the electrode 102 is zero.

  Specifically, when the pixel color is changed from white to black, the potential of the row pixel drive signal for one cycle (100 [ms]) used for driving this pixel is the first 5 [ms]. 50 [V] in the period and −50 [V] in the next 95 [ms] period, and the potential of the column pixel drive signal for one cycle is −50 [V] in the first 5 [ms] period. In the next 95 [ms] period, it becomes 50 [V]. Therefore, when driving this pixel, the voltage between the transparent electrode 101 and the electrode 102 is 100 [V] in the first 5 [ms] period and −100 [V] in the next 95 [ms] period. When a voltage of −100 [V] is continuously applied between the transparent electrode 101 and the electrode 102 for a time of 95 [ms], the relationship between this voltage and the application time satisfies the movement start condition. In the period of [ms], the positive black particles 108 attached to the dielectric layer 104 move and adhere to the dielectric layer 106, and the negative white particles 109 attached to the dielectric layer 106 move. Then, it adheres to the dielectric layer 104.

  On the contrary, when the color of the pixel is changed from black to white, the potential of the row pixel drive signal for one cycle used for driving the pixel is −50 [V] in the first 5 [ms] period, In the next 95 [ms] period, the potential of the column pixel drive signal for one cycle is 50 [V] in the first 5 [ms] period and the next 95 [ms]. In the period, it becomes −50 [V]. Therefore, when this pixel is driven, the voltage between the transparent electrode 101 and the electrode 102 is −100 [V] in the first 5 [ms] period and 100 [V] in the next 95 [ms] period. When a voltage of 100 [V] is continuously applied between the transparent electrode 101 and the electrode 102 for a time of 95 [ms], the relationship between the voltage and the application time satisfies the movement start condition. ms], the negative white particles 109 attached to the dielectric layer 104 move and adhere to the dielectric layer 106, and the positive black particles 108 attached to the dielectric layer 106 move. And adhere to the dielectric layer 104.

  When the color of the pixel is maintained, the potentials of the row pixel drive signal and the column pixel drive signal for one cycle used for driving the pixel are both 0 [V] constant. Therefore, when this pixel is driven, the voltage between the dielectric layer 104 and the dielectric layer 106 is constant at 0 [V]. In this case, neither the positive black particles 108 nor the negative white particles 109 move.

  As shown in FIG. 1, the present coordinate input device applied to the above-described image display device has a row coordinate signal driving circuit 116 that outputs a row coordinate signal by varying the potential at the output end, and the potential at the output end. A column coordinate signal drive circuit 117 that outputs a column coordinate signal by changing the row, and a row that switches an output terminal connected to the row signal scanning circuit 114 between the row pixel drive circuit 112 and the row coordinate signal drive circuit 116. Column signal switching circuit 119, the column signal switching circuit 119 for switching the output terminal connected to the row signal scanning circuit 114 between the column pixel driving circuit 113 and the column coordinate signal driving circuit 117, and the electric field at the designated position. Using the electric field detection device 120 for detecting the change in the current value and the change detected by the electric field detection device 120, a value indicating the coordinates of the pixel at the designated position is obtained and stored, and is determined from the stored value. With coordinates determination circuit 121 outputs the coordinates. Further, the row signal scanning circuit 114 and the column signal scanning circuit 115 are not only components of the image display device described above but also components of the coordinate input device.

  The row signal switching circuit 118 uses the output terminal connected to the row signal scanning circuit 114 as the output terminal of the row pixel drive circuit 112 at the start of the output of the pixel drive signal for one screen, and outputs this pixel drive signal. At the end of the operation, the output terminal of the row coordinate signal driving circuit 116 is used. When the output terminal is connected to the row signal scanning circuit 114, the row coordinate signal driving circuit 116 repeatedly outputs the row coordinate signal at a predetermined time interval. The column signal switching circuit 119 uses the output terminal connected to the column signal scanning circuit 115 as the output terminal of the column pixel driving circuit 113 at the start of the output of the pixel driving signal for one screen. At the end of the output, the output terminal of the column coordinate signal drive circuit 117 is used. When the first output of the row coordinate signal from the row coordinate signal drive circuit 116 is completed, the column coordinate signal drive circuit 117 repeatedly outputs the column coordinate signal at a predetermined time interval.

  FIG. 4 is a diagram illustrating output timings of the row pixel drive signal, the column pixel drive signal, the row coordinate signal, and the column coordinate signal. In this figure, pixel drive signals for changing the colors of all the pixels are illustrated. In this figure, the signal in the section T1 is a pixel drive signal, the signal in the section T2 after the section T1 is the row coordinate signal, and the signal in the section T3 after the section T2 is the column coordinate signal. As described above, the output of the row coordinate signal and the output of the column coordinate signal are alternately and exclusively performed until the output of the pixel drive signal is started next. Therefore, the output order of each signal is as follows: row pixel drive signal, column pixel drive signal, row coordinate signal, column coordinate signal, row coordinate signal, column coordinate signal, ..., row pixel drive signal, column The pixel drive signals are in this order. Note that the number of times the row coordinate signal and the column coordinate signal are repeatedly output in succession is a plurality of times, but the present embodiment may be modified to be one time. Further, the present embodiment may be modified such that the column coordinate signal is output before the row coordinate signal.

The row coordinate signal is a signal obtained by connecting pulse signals (a high level is 40 [V] and a low level is −40 [V]) corresponding to the number of rows of pixels. The first potential change direction in these pulse signals is the minus direction. When expressed using the natural number i, the pulse signal Ri representing the row coordinate of the i-th row is a pulse signal obtained by connecting pulses having a period of 100 [μs] for i + 1 periods. The row signal scanning circuit 114 applies the pulse signal Ri to the i-th row electrode 110 by sequentially switching the row electrodes 110 to which row coordinate signals are applied.
The column coordinate signal is a signal in which pulse signals representing column coordinates (a high level is 40 [V] and a low level is −40 [V]) are connected by the number of columns of pixels. The initial potential change direction in these pulse signals is the plus direction. When expressed using the natural number j, the pulse signal Cj representing the column coordinate of the j-th column is a pulse signal obtained by connecting pulses having a cycle of 100 [μs] for j + 1 cycles. The column signal scanning circuit 115 applies the pulse signal Cj to the column electrode 111 of the j-th column by sequentially switching the column electrode 111 to which the column coordinate signal is applied. In these coordinate signals, the potential between the pulse signals is 0 [V]. The number of pulses in the pulse signal Ri is set to i + 1, and the number of pulses in the pulse signal Cj is set to j + 1 to distinguish the pulse signal for the first row and the pulse signal for the first column from other signals such as noise. This is to make it easier.

  FIG. 5 is a diagram illustrating a state in which the row coordinate signal is applied to the row electrode 110 and the column coordinate signal is applied to the column electrode 111. As shown in this figure, the row coordinate signal includes a pulse signal R1 constituting the row coordinate signal first to the row electrode 110 of the first row, and then a pulse signal R2 to the row electrode 110 of the second row. It is applied like this. During this time, the column signal scanning circuit 115 connects neither the column pixel drive circuit 113 nor the column coordinate signal drive circuit 117 to the column electrode 111. For this reason, the voltage between the transparent electrode 101 to which the row coordinate signal is applied and the electrode 102 facing the same coincides with the potential of the pulse signal applied to the row electrode 110. When the application of the row coordinate signal to the row electrode 110 is completed, the column coordinate signal is applied to the column electrode 111. For the column coordinate signal, first, the pulse signal C1 constituting the column coordinate signal is applied to the first column electrode 111, the pulse signal C2 is then applied to the second column electrode 111, and so on. Is done. During this time, the row signal scanning circuit 114 connects neither the row pixel drive circuit 112 nor the row coordinate signal drive circuit 116 to the row electrode 110. Therefore, the voltage between the electrode 102 to which the column coordinate signal is applied and the transparent electrode 101 facing the electrode 102 is obtained by reversing the positive / negative of the potential of the pulse signal applied to the row electrode 110. Become.

  As described above, the pulse period of the pixel drive signal is 100 [ms], and the pulse period of the coordinate signal is 100 [μs]. Since there is a large difference between the two, in FIG. 4, the pulse of the pixel driving signal and the pulse of the coordinate signal are drawn with different time scales. In this embodiment, the row coordinate signal and the column coordinate signal have the same period, high potential, and negative potential of the pulse signal. However, they may be modified so that they differ. These specific values may also be arbitrarily set within a range where the coordinate detection accuracy does not decrease. However, the waveform of the coordinate signal (the value of the high potential, the value of the negative potential, and the pulse period) is the voltage between the transparent electrode 101 and the electrode 102 when the coordinate signal is applied, and the application time of the voltage. Should be determined not to satisfy This determination ensures that no change in pixel color is caused by the application of coordinate signals.

  As shown in FIG. 1, the electric field detection device 120 is generated by a pen-shaped pickup 1201 that is held by a person who indicates a position and changes an internal current in accordance with a change in the electric field at the specified position. And a signal detection circuit 1202 for detecting an electric current change and sending an electric signal representing the detected current change to the coordinate discrimination circuit 121. For example, the electrical configuration of the pickup 1201 is as shown in FIG. The pickup 1201 in FIG. 2 has a pickup electrode A at the tip, one end of a resistor B is connected to the pickup electrode A, and the potential at the other end of the resistor B is set to a constant reference potential (for example, 0 [V]). The structure is taken. The signal detection circuit 1202 detects a change in the current flowing through the resistor B. When the change is detected, the signal detection circuit 1202 sends an electrical signal representing the detected change as a waveform to the coordinate determination circuit 121. In this configuration, the pickup electrode A functions as one electrode of the capacitor during coordinate detection.

  The coordinate discrimination circuit 121 has a memory (not shown), and stores a waveform pattern in advance for each of all pulse signals representing row coordinates and all pulse signals representing column coordinates used in the coordinate input device. . The coordinate determination circuit 121 compares the waveform of the electrical signal sent from the signal detection circuit 1202 with a waveform pattern stored in advance, identifies a waveform pattern that matches the electrical signal, and identifies the identified waveform pattern. A value corresponding to is obtained and written in a predetermined area of the memory. The value written in the memory takes a positive value representing a row if the value represents a row coordinate, and takes a negative value representing a column if the value represents a column coordinate. For example, “1” represents the first row and “−1” represents the first column.

  Of course, the format of the value representing the row coordinate / column coordinate is arbitrary, and for example, the first row may be represented by a character string “X1” and the first column may be represented by a character string “Y1”. If it is known that the row coordinates are obtained first and the column coordinates are obtained next, it is not necessary to use a code or a character string for identifying the row coordinates / column coordinates. In the form, a position that is not known is taken, and positive / negative values are used to identify row coordinates / column coordinates. A method for obtaining a value from the specified waveform pattern is also arbitrary. For example, the waveform pattern and the row coordinate / column coordinate may be stored in association with each other, and the row coordinate / column coordinate corresponding to the specified waveform pattern may be selected. Based on the number of pulses (for example, two) and the first potential change direction (for example, plus direction) of the signal shown, a value (for example, “1”) representing the row coordinate / column coordinate may be calculated.

  In addition, when the coordinate determination circuit 121 obtains a set of row coordinates and column coordinates, it outputs coordinates represented by these values. In the present embodiment, a computer device (not shown) that inputs coordinates output from the coordinate determination circuit 121 may be a device having the coordinate signal drive circuits 116 and 117, or the coordinate signal drive circuits 116 and 117 may be used. It may be a device that does not have it. For this reason, the coordinate discrimination circuit 121 operates as follows. When determining the row coordinates, if the column coordinates are stored in a predetermined area of the memory, the coordinate determination circuit 121 outputs the row coordinates and the coordinates represented by the column coordinates, and the determined row coordinates are determined in advance. Overwrite the area. If the row coordinates are stored in the predetermined area of the memory when the column coordinates are obtained, the coordinates represented by these row coordinates and column coordinates are output, and the obtained column coordinates are overwritten on the predetermined area. . When the output of the row pixel drive signal and the column pixel drive signal for one screen is completed, the predetermined area is initialized.

  The above memory is composed of only a rewritable memory or a rewritable memory and a non-rewritable memory. In the latter configuration, the predetermined area is secured in a rewritable memory, and the waveform pattern is stored in a non-rewritable memory or a rewritable memory. Of course, if the row coordinates and the column coordinates may be output individually from the coordinate determination circuit 121, the predetermined area is not necessary, and therefore the rewritable memory is unnecessary in the latter configuration.

  In FIG. 1, the pickup 1201 and the signal detection circuit 1202 are depicted as being connected by a signal line. However, in order to improve the operability of the pickup 1201, the signal detection circuit 1202 is actually picked up. The configuration provided in 1201 is adopted. In this embodiment, the signal detection circuit 1202 wirelessly transmits an electrical signal to the coordinate determination circuit 121 in order to improve the operability of the pickup 1201. Of course, the signal detection circuit 1202 and the coordinate determination circuit 121 are provided in the pickup 1201, and the coordinate determination circuit 121 transmits an output signal to a computer device (not shown) by wire or wireless, and the computer device receives the output signal. The coordinates may be input to the computer device. Note that “wireless” in this specification includes radio waves and infrared rays.

[Operation]
The operation of the coordinate input device having the above-described configuration will be described.
First, the image display device scans the screen and displays an image. At this time, in the pixel in which the color is maintained, the potentials of the transparent electrode 101 and the electrode 102 are both 0 [V] constant, and the positive black particles 108 and the negative white particles 109 in the cavity of the pixel do not move. That is, both particles remain stationary. Therefore, the color of the pixel is maintained. By the way, when the pickup electrode A is in contact with the glass substrate 107 constituting the pixel, the current flowing through the resistor R connected to the pickup electrode A corresponds to the change in the potential of the transparent electrode 101 and the electrode 102 of the pixel. Change. However, in the pixel in which the color is maintained, since the potentials of the transparent electrode 101 and the electrode 102 are both 0 [V] constant, the current flowing through the resistor R does not change. Therefore, coordinates are not input to a computer device (not shown).

  On the other hand, in the pixel whose color is changed, the potentials of the transparent electrode 101 and the electrode 102 vary. For example, when the color of this pixel is changed from white to black, the potentials of both electrodes 101 and 102 are both 0 [V] before the driving period of this pixel, and the first 5 [ms] in this driving period. In the period, the potential of the transparent electrode 101 is 50 [V] and the potential of the electrode 102 is −50 [V]. In the next 95 [ms] period in this driving period, the potential of the transparent electrode 101 is −50 [V]. ] And the potential of the electrode 102 becomes 50 [V]. When this driving period ends, the potentials of both the electrodes 101 and 102 both become 0 [V]. The voltage between the transparent electrode 101 and the electrode 102 in the period of 95 [ms] is −100 [V], and the relationship between this voltage and the time is determined by the movement start voltage and the movement start time shown in FIG. Since the condition is satisfied, in the period of 95 [ms], the positive black particles 108 attached to the dielectric layer 104 move and adhere to the dielectric layer 106, and the negative polarity attached to the dielectric layer 106. The white particles 109 move and adhere to the dielectric layer 104. Since the color of the particles existing on the dielectric layer 106 side is observed through the glass substrate 107, the transparent electrode 101, and the dielectric layer 106, the color of this pixel is changed from white to black. .

  When the pickup electrode A is in contact with the pixel during the driving period of the pixel, the current flowing through the resistor R changes according to the potential change of the transparent electrode 101 and the column electrode 111 of the pixel during the driving period of the pixel. . The signal detection circuit 1202 detects this current change, and sends an electric signal representing the detected current change as a waveform to the coordinate determination circuit 121. The waveform of the electrical signal is in accordance with only the pixel drive signal, and does not match any of the waveform patterns stored in advance in the coordinate determination circuit 121, so the coordinate determination circuit 121 does not output coordinates. Therefore, in this case, coordinates are not input to a computer device (not shown).

  As described above, coordinates are not input during screen scanning. The coordinates are entered after the screen scan is completed. When the scanning of the screen is completed, the row signal switching circuit 118 uses the output terminal of the row coordinate signal driving circuit 116 as the row signal scanning circuit 114, and the column signal switching circuit 119 uses the output terminal of the column coordinate signal driving circuit 117. Are connected to the column signal scanning circuit 115. Thereafter, the row coordinate signal drive circuit 116 and the column coordinate signal drive circuit 117 alternately output the row coordinate signal and the column coordinate signal. In the following description, the position near the pixel in the second row and the third column is indicated using the pickup 1201 before the first output of the row coordinate signal, and before the second output of the row coordinate signal is started. Assume that the position near the pixel in the first row and the third column is indicated.

  FIG. 6 is a diagram showing a state of coordinate input by this coordinate input device, and this figure shows a state in the first output period of the row coordinate signal and the column coordinate signal. As is clear from this figure, the pulse signal R1, which represents the row coordinates of the first row, the pulse signal R2, which represents the row coordinates of the second row, and the like constituting the row coordinate signal are generated by the row signal scanning circuit 114. It is cut out from the row coordinate signal and applied to the corresponding row electrode 110. Further, the pulse signal C1, which represents the column coordinates of the first column, the pulse signal C2, which represents the column coordinates of the second column, which constitute the column coordinate signal, is cut out from the column coordinate signal by the column signal scanning circuit 115. And applied to the corresponding column electrode 111. Hereinafter, the operation of the coordinate input apparatus will be described by focusing on the pulse signal R2 and pulse signal in the coordinate signal output for the first time and the pulse signal R1 in the row coordinate signal output for the second time.

  FIG. 7 is a diagram illustrating a state in which the signal detection circuit 1202 outputs an electrical signal representing row coordinates. As shown in this figure, when the pulse signal R2 is applied to the row electrode 110 of the second row at the first output of the row coordinate signal, the potential of the row electrode 110 becomes 0 [V], −40 [ V], 40 [V], −40 [V], 40 [V], −40 [V], 40 [V], and 0 [V]. During this time, the column electrode 111 in the third column is not connected to either the column pixel drive circuit 113 or the column coordinate signal drive circuit 117, and its potential is constant at 0 [V]. The period during which the potential of the row electrode 110 is continuously −40 [V] or 40 [V] is 50 [μs]. That is, the voltage between the transparent electrode 101 and the electrode 102 of the pixel in the second row and third column and the application time do not satisfy the movement start condition. Therefore, the color of this pixel does not change.

  Since the potentials of the transparent electrode 101 and the electrode 102 of the pixel change as described above, the current flowing through the resistor R connected to the pickup electrode A in contact with the pixel changes according to the change. The first principle that is the principle of this change will be described. When the potential of the transparent electrode 101 is not 0 [V], the electric field lines are generated between the electrode 101 and the pickup electrode A through the glass substrate 107, and an electric field is formed. This electric field changes according to the waveform of the signal applied to the transparent electrode 101. A change corresponding to this electric field change occurs in the current flowing through the resistor R.

  When the pulse signal R2 is applied to the row electrode 110 of the second row, the current flowing through the resistor R changes according to the first principle described above, and an electrical signal indicating this change is sent from the signal detection circuit 1202 to the coordinate discrimination circuit 121. Sent to. Since the potential of the column electrode 111 in the third column during the output period of the pulse signal R2 is constant at 0 [V], this electric signal is a signal having a waveform corresponding only to the row coordinate signal. Therefore, the waveform of the electrical signal matches the waveform pattern related to the second row among the waveform patterns stored in advance in the coordinate determination circuit 121. Therefore, the coordinate determination circuit 121 obtains a value “2” representing the row coordinates from this waveform pattern. At this time, since the value (negative value) representing the column coordinates is not stored in the predetermined area of the memory, the coordinate determination circuit 121 does not output the coordinates and the obtained value “2” is stored in the predetermined area of the memory. Write.

  FIG. 8 is a diagram illustrating a state in which the signal detection circuit 1202 outputs an electrical signal representing column coordinates. As shown in this figure, when the pulse signal C3 is applied to the third column electrode 111 at the first output of the column coordinate signal, the potential of the column electrode 111 becomes 0 [V], 40 [V]. ], −40 [V], 40 [V], −40 [V], 40 [V], −40 [V], 40 [V], −40 [V], and 0 [V]. . During this time, the row electrode 110 of the second row is not connected to either the row pixel drive circuit 112 or the row coordinate signal drive circuit 116, and its potential is constant at 0 [V]. The period during which the potential of the column electrode 111 is continuously 40 [V] or −40 [V] is 50 [μs]. That is, the voltage between the transparent electrode 101 and the electrode 102 of the pixel in the second row and third column and the application time do not satisfy the movement start condition. Therefore, the color of this pixel does not change.

  Since the potentials of the transparent electrode 101 and the electrode 102 relating to this pixel change as described above, the current flowing through the resistor R connected to the pickup electrode A in contact with this pixel changes according to this change. The second principle that is the principle of this change will be described. When the potential of the electrode 102 is not 0 [V], the electric force is transmitted between the electrode 102 and the pickup electrode A through the dielectric layer 104, the cavity, the dielectric layer 106, the transparent electrode 101, and the glass substrate 107. Lines are generated and an electric field is formed. This electric field changes according to the waveform of the signal applied to the electrode 102. A change corresponding to this electric field change occurs in the current flowing through the resistor R. When the pulse signal C3 is applied to the column electrode 111 of the third column, the current flowing through the resistor R changes according to the second principle described above, and an electrical signal indicating this change is sent from the signal detection circuit 1202 to the coordinate discrimination circuit 121. Sent to. Since the potential of the row electrode 110 in the second row during the output period of the pulse signal C3 is constant at 0 [V], this electric signal is a signal having a waveform corresponding only to the column coordinate signal. Therefore, the waveform of the electrical signal matches the waveform pattern related to the third column among the waveform patterns stored in advance in the coordinate determination circuit 121. Therefore, the coordinate determination circuit 121 obtains a value “−3” representing the column coordinates from this waveform pattern. At this time, since the value “2” representing the row coordinates is stored in the predetermined area of the memory, the coordinate determination circuit 121 has the coordinates represented by this value “2” and the obtained value “−3”. And the obtained value “−3” is written in a predetermined area of the memory. The coordinates output from the coordinate determination circuit 121 are coordinates indicating the second row and the third column, and are input to a computer device (not shown).

  When the pulse signal R1 is applied to the row electrode 110 of the first row in the second output period of the row coordinate signal, the potential of the row electrode 110 becomes 0 [V], −40 [V], 40 [V]. ], −40 [V], 40 [V], and 0 [V]. During this time, since the potential of the column electrode 111 in the third column is constant at 0 [V], the color of the pixel in the first row and the third column does not change. Since the pickup electrode A is in contact with the pixel during the driving period of the pixel, the signal detection circuit 1202 sends an electric signal having a waveform corresponding only to the row coordinate signal to the coordinate determination circuit 121. Since the waveform of the electrical signal matches the waveform pattern related to the first row among the waveform patterns stored in advance in the coordinate determination circuit 121, the coordinate determination circuit 121 uses the value “1” representing the row coordinate from the waveform pattern. " At this time, since the value “−3” representing the column coordinates is stored in the predetermined area of the memory, the coordinate determination circuit 121 represents the value “−3” and the calculated value “1”. The coordinates are output, and the obtained value “1” is written in a predetermined area of the memory. The coordinates output from the coordinate determination circuit 121 are coordinates indicating the first row and the third column, and are input to a computer device (not shown). As described above, in the present embodiment, even when the row coordinate is detected following the column coordinate in the period in which the row coordinate signal and the column coordinate signal are continuously and alternately output, the coordinate determination circuit 121 can output the coordinates. Since the predetermined area of the memory is initialized when the output of the column pixel driving signal is completed next time, even if the column coordinate value is written in the predetermined area immediately before the second screen scan, this column Coordinates are not output from the coordinate determination circuit 121 based on the coordinates and the line coordinates detected immediately after the second screen scan.

  As described above, according to the present embodiment, the row coordinate signal is applied to the pixel driving row electrode 110 to change the potential of the transparent electrode 101 to cause an electric field change, so that the pickup electrode A is in contact with the pixel electrode. Indirect detection of the electric field change that occurs in the pixel being converted into current change, and the row coordinate is obtained using the detection result, while the column coordinate signal is applied to the pixel electrode 111 for driving the pixel. The potential of the electrode 102 is changed to generate an electric field change, and the electric field change generated in the pixel in contact with the pickup electrode A is converted into a current change to be detected indirectly, and the column coordinates are determined using the detection result. You can ask. Thereby, according to this embodiment, the coordinate of the position instruct | indicated on the screen can be calculated | required. In addition, since the voltage applied between the transparent electrode 101 and the electrode 102 when the coordinate signal is applied and the application time do not satisfy the movement start condition, according to this embodiment, the color of the pixel is obtained when obtaining the coordinates. The coordinates of the designated position on the screen can be obtained without changing the value.

  In addition, according to the present embodiment, the pickup 1201 used for position indication is in direct contact with the screen, and it is necessary to form a layer such as a touch panel on the front surface of the particle movement type image display device. Therefore, the brightness and contrast of the displayed image will not be reduced. That is, according to the present embodiment, the coordinates of the designated position on the screen can be input without reducing the visibility of the display image.

  In addition, according to the present embodiment, a configuration is employed in which a coordinate is obtained by detecting a current change in the pickup 1201, and it is not necessary to secure an optical path parallel to the screen on the screen. Even if there is an object other than, the coordinates of the designated position on the screen can be reliably detected.

  In the present embodiment, means to be newly provided when applying the coordinate input device to the particle movement type image display device are the row coordinate signal drive circuit 116, the column coordinate signal drive circuit 117, and the row signal switching circuit. 118, the column signal switching circuit 119, the electric field detection device 120, and the coordinate discrimination circuit 121. Of these, all except the electric field detection device 120 are circuits, and can be easily downsized and integrated. Further, the function of the electric field detection device 120 is simple, and it is easy to simplify the configuration. Therefore, according to the present embodiment, the configuration of the coordinate input device can be made small and simple.

  Also, compared to a coordinate input device that detects coordinates using a touch panel, it is not necessary to use an analog detection circuit with low accuracy, and according to this embodiment, coordinates can be detected with high accuracy.

  In the present embodiment, the electric field change is detected using the capacitor type pickup 1201, but may be modified so as to be detected using a liquid crystal element. This modification is also possible in the second and third embodiments described later. Hereinafter, this modification will be described.

  FIG. 9 is a diagram for explaining a coordinate input device that detects a change in an electric field using a liquid crystal element. The difference between the coordinate input device shown in this figure and the coordinate input device in the embodiment described above is only that it has an electric field detection device 122 instead of the electric field detection device 120. The electric field detection device 122 has a pen shape, has a plate-like transparent electrode C near the tip thereof, and adopts a configuration in which the transparent electrode C is set to a constant reference potential (for example, 0 [V]). Yes. A liquid crystal shutter D in which liquid crystal cells are arranged in a plate shape is provided at the tip of the electric field detection device 122. One surface of the liquid crystal shutter D is in contact with the transparent electrode C, and the other surface is in contact with the glass substrate 107 when inputting coordinates.

  In addition, the electric field detection device 122 includes a detection unit E. The detection unit E includes a light source that irradiates light, an optical system that guides irradiation light from the light source so that a light beam is perpendicularly incident on the liquid crystal shutter D, an optical pickup that receives reflected light from the glass substrate 107, a reflection The polarizing plate H has a transmittance that changes depending on the polarization direction of the light, and a detection circuit that detects a change in the intensity of the reflected light and sends an electrical signal representing the detected change in a waveform to the coordinate discrimination circuit 121. This detection circuit outputs an electric signal having the same waveform as that of the signal detection circuit 1202 if the row electrode 110 and the column electrode 111 to which the coordinate signal is applied are the same.

  In the coordinate input device having this configuration, the pulse signal R1 is applied to the row electrode 110 in the first row while the liquid crystal shutter D at the tip of the electric field detection device 122 is in contact with the glass substrate 107 of the pixel in the first row. Shall. In this case, the potential of the transparent electrode 101 in the first row changes according to the pulse signal R1. On the other hand, since the potential of the pickup electrode C is a constant reference potential, the electric field applied to the liquid crystal shutter D sandwiched between the transparent electrode 101 and the pickup electrode C depends on the waveform of the pulse signal R1. Change. The liquid crystal shutter D changes the alignment direction of the liquid crystal according to the change of the electric field, and rotates the polarization direction of the reflected light. The reflected light after rotation passes through the polarizing plate H. For this reason, the intensity of the reflected light after transmission changes according to the waveform of the pulse signal R1.

  Therefore, in the above case, in the detection unit E, the electric field change according to the waveform of the pulse signal R1 is indirectly detected as a change in reflectance, and an electric signal representing the detected change in the waveform is sent to the coordinate determination circuit 121. It is done.

[Second Embodiment]
[Constitution]
FIG. 10 is a diagram showing the configuration of the coordinate input device according to the second embodiment of the present invention. In this coordinate input device, the pixel drive signal and the coordinate signal are not switched and applied to the electrode, but the coordinate signal is superimposed on the pixel drive signal and applied to the electrode. The configuration of the image display device to which this coordinate input device is applied is the same as the configuration of the image display device according to the first embodiment. The configuration of the coordinate input device is different from the configuration of the coordinate input device according to the first embodiment in that the row coordinate signal driving circuit 116, the column coordinate signal driving circuit 117, the row signal switching circuit 118, and the column signal switching. Instead of the circuit 119 and the coordinate discriminating circuit 121, only the point having the row coordinate signal driving circuit 201, the column coordinate signal driving circuit 202, the row signal superimposing circuit 203, the column signal superimposing circuit 204, and the coordinate discriminating circuit 205 is used. is there.

  FIG. 11 is a diagram illustrating output timings of the row pixel drive signal, the column pixel drive signal, the row coordinate signal, and the column coordinate signal. In the figure, signal c is a row pixel drive signal, signal d is a column pixel drive signal, signal e is a row coordinate signal, and signal f is a column coordinate signal. In this figure, in order to easily understand the change timing of each signal, a row pixel drive signal and a column pixel drive signal for changing the color of all the pixels from white to black are illustrated.

  As shown in this figure, the row coordinate signal drive circuit 201 outputs a row coordinate signal in parallel with the output of the row pixel drive signal from the row pixel drive circuit 112. The row coordinate signal is a signal in which pulse signals (high level is 0 [V] and low level is −80 [V]) representing the row coordinates are connected by the number of rows of pixels. Each pulse signal constituting the row coordinate signal is output when the row pixel drive signal is first applied to the row electrode 110 of the corresponding row coordinate. For example, the pulse signal representing the row coordinates of the first row is output immediately after the row pixel drive signal for driving the pixels of the first row and first column changes from 50 [V] to −50 [V]. The pulse signal representing the row coordinates of the two rows is output immediately after the row pixel drive signal for driving the pixels in the second row and first column changes from 50 [V] to −50 [V].

  The column coordinate signal drive circuit 202 outputs a column coordinate signal in parallel with the column pixel drive signal output from the column pixel drive circuit 113. The column coordinate signal is a signal in which pulse signals representing column coordinates (low level is 0 [V] and high level is 80 [V]) are connected by the number of columns of pixels. Each pulse signal constituting the column coordinate signal is output every time a column pixel drive signal is applied to the column electrode 111 of the corresponding column coordinate. For example, the pulse signal representing the column coordinates of the first column is being driven from when the column pixel drive signal applied to the column electrode 111 of the first column changes from −50 [V] to 50 [V]. It is output immediately after the time of the length of the pulse signal corresponding to the pixel row coordinate (the pulse signal constituting the row coordinate signal) has elapsed. Of course, the column coordinate signal drive circuit 202 generates a pulse signal representing the column coordinate of the first column, and the column pixel drive signal applied to the column electrode 111 of the first column ranges from −50 [V] to 50 [V]. It may be modified so that it is output immediately after the time corresponding to the maximum value of the length of the pulse signal constituting the row coordinate signal has elapsed since the change to. In the coordinate signal, the potential between the pulse signals is 0 [V], and the pulse period is 100 [μs].

  The row signal superimposing circuit 203 has two input ends, one input end is connected to the output end of the row pixel drive circuit 112, and the other input end is connected to the output end of the row coordinate signal drive circuit 201. ing. The row signal superimposing circuit 203 has one output terminal, and the potential of this output terminal is set to a potential obtained by subtracting the potential of one input terminal from the potential of the other input terminal. However, if the positive and negative potentials of one input terminal and the other input terminal are different, the above subtraction is performed after inverting the positive and negative potentials of the other input terminal. That is, the row signal superimposing circuit 203 outputs a signal obtained by superimposing the row coordinate signal on the row pixel drive signal from the output end, and applies the signal to the row electrode 110 via the row signal scanning circuit 114. The column signal superimposing circuit 204 has the same function as the row signal superimposing circuit 203 for the row pixel drive signal and the row coordinate signal sequence.

  Although the length and the waveform of the pulse signal constituting the coordinate signal are basically arbitrary, in this embodiment, when the voltage is directly applied to the transparent electrode 101 and the electrode 102, the voltage between both electrodes and the application time thereof are When the relationship is superimposed on the pixel drive signal that satisfies the movement start condition, the above relationship satisfies the movement start condition and is directly applied to both electrodes when the superimposed signal is applied to both electrodes. If the above relationship is superimposed on a pixel drive signal that does not satisfy the movement start condition when applied, the above relationship is the movement start condition when the superimposed signal is applied to both electrodes. It is stipulated not to satisfy. By defining the coordinate signal in this way, it is ensured that no change in pixel color is caused by the use of the coordinate signal.

  The difference between the coordinate determination circuit 205 and the coordinate determination circuit 121 is only the waveform pattern stored in advance in the memory. In this embodiment, since the signal applied to the electrode is a signal in which the coordinate signal is superimposed on the pixel drive signal, even if the designated position is the same, depending on the state of the pixel drive signal on which the coordinate signal is superimposed, The waveforms of the electrical signals sent from the electric field detection device 120 are different. For this reason, a plurality of waveform patterns for one row coordinate and a plurality of waveform patterns for one column coordinate are stored in advance in the memory of the coordinate determination circuit 205.

[Operation]
The operation of the coordinate input device having the above-described configuration will be described.
First, the image display device scans the screen and displays an image. At this time, the row pixel drive signal output from the row pixel drive circuit 112 and the column pixel drive signal output from the column pixel drive circuit 113 are both 0 [V] constant for the pixels whose color is maintained. The row signal superimposing circuit 203 superimposes the row coordinate signal output by the row coordinate signal driving circuit 201 for the pixel on the row pixel driving signal, and outputs a signal obtained thereby. The column signal superimposing circuit 204 superimposes the column coordinate signal output by the column coordinate signal driving circuit 202 for the pixel on the column pixel driving signal, and outputs a signal obtained thereby. These signals are applied to the row electrode 110 corresponding to the row coordinate of the pixel and the column electrode 111 corresponding to the column coordinate of the pixel, respectively. Eventually, the signal applied to the row electrode 110 becomes a signal (hereinafter referred to as a row inversion signal) obtained by inverting the positive / negative of the potential of the row coordinate signal, and the signal applied to the column electrode 111 is This is a signal obtained by reversing the polarity of the potential of the column coordinate signal (hereinafter referred to as a column inversion signal).

  When this pixel is the pixel in the first column, the potential of the row electrode 110 of this pixel is first 0 [V] constant, then changes according to the waveform of the row inversion signal, and finally becomes 0 [V] constant. . On the other hand, the potential of the column electrode 111 of this pixel is constant at 0 [V] until the potential change of the row electrode 110 according to the waveform of the row inversion signal is completed. It changes according to the waveform and finally becomes 0 [V] constant. That is, the voltage between the transparent electrode 101 and the electrode 102 of this pixel changes in the order of 0 [V], the potential of the row inversion signal, the potential of the column coordinate signal, and 0 [V]. In the end, the voltage applied between the transparent electrode 101 and the electrode 102 of this pixel is −80 [V] to 80 [V], and the row coordinate signal and the column coordinate signal Both pulse periods are 100 [μs]. Therefore, the relationship between the voltage between the transparent electrode 101 and the electrode 102 of this pixel and the application time does not satisfy the movement start condition. Therefore, the color of this pixel is maintained.

  If the pickup electrode A is in contact with the pixel while such driving is being performed on the pixel, the pixel is first connected to the pickup electrode A by the first principle and then by the second principle. The current flowing through the resistor R changes. The electric field detection device 120 sends an electrical signal representing this change to the coordinate discrimination circuit 205. This electrical signal is a signal obtained by connecting two signals. The previous signal is a signal corresponding to the row inversion signal, and the subsequent signal is a signal corresponding to the column coordinate signal. When receiving the electrical signal from the electric field detection device 120, the coordinate discrimination circuit 205 compares this waveform with a previously stored waveform pattern, identifies a waveform pattern that matches the electrical signal, and identifies the identified waveform pattern. If the row coordinate or column coordinate corresponding to is obtained and the column coordinate or row coordinate is not written in the predetermined area of the memory, the obtained row coordinate or column coordinate is written in the predetermined area. Output the coordinates represented by the obtained column coordinates or row coordinates and the obtained row coordinates or column coordinates, and overwrite the obtained row coordinates or column coordinates in the predetermined area.

  When the pixel to be driven is a pixel in which the color is maintained and the pixel in the first row and the first column, it changes in accordance with the waveform of the row inversion signal and the waveform of the column coordinate signal. The electrical signals are in-phase signals, and the number of pulses of both is equal, but the dielectric constant of the capacitor using the pickup electrode A and the transparent electrode 101 as the capacitor electrode and the capacitor using the pickup electrode A and the electrode 102 as the capacitor electrode Since the dielectric constants are different, the levels of the corresponding parts in both signals are different. Therefore, the coordinate determination circuit 205 can obtain row coordinates for the former electrical signal and column coordinates for the latter electrical signal.

  On the other hand, when the pixels other than the first column are driven so as to maintain the color, the row pixel drive signal, the column pixel drive signal, and the row coordinate signal related to this pixel are constant at 0 [V]. Therefore, in the driving period of this pixel, the potential of the row electrode 110 corresponding to the row coordinate of this pixel is constant at 0 [V]. On the other hand, a column inversion signal is applied to the column electrode 111 corresponding to the column coordinate of the pixel. Therefore, the voltage between the transparent electrode 101 and the electrode 102 of this pixel changes in the order of 0 [V], the potential of the column coordinate signal, and 0 [V]. In addition, since the relationship between the voltage applied between the transparent electrode 101 and the electrode 102 of this pixel and the application time does not satisfy the movement start condition, the color of this pixel is maintained.

  If the pickup electrode A is in contact with the pixel while such driving is performed on the pixel, the electric field detection device 120 changes to the coordinate determination circuit 205 according to the waveform of the column coordinate signal. Send an electrical signal. The coordinate discriminating circuit 205 compares the waveform of the electrical signal with a waveform pattern stored in advance, identifies a waveform pattern that matches the electrical signal, obtains column coordinates corresponding to the identified waveform pattern, and stores the memory Overwrite the specified area. Prior to this overwriting, the coordinate determination circuit 205 outputs coordinates represented by the row coordinates and the obtained column coordinates if the row coordinates are written in a predetermined area of the memory.

FIG. 12 is a diagram showing the waveforms of signals output from the row signal superimposing circuits 203 and 204. This figure assumes that the color of all pixels is changed from white to black.
When the pixel to be driven is a pixel whose color is changed from white to black and a pixel in the first column, as shown in FIG. 12, the potential of the signal output from the row signal superimposing circuit 203 in this driving period. Is roughly 50 [V] in the first 5 [ms] period and −50 [V] in the next 95 [ms] period according to the row pixel drive signal for this pixel. More specifically, in the vicinity of the head of the period of 95 [ms], it fluctuates in a short cycle according to the row coordinate signal for this pixel. The potential near the beginning of the period of 95 [ms] is, for example, −50 [V], 30 [V], −50 [V], 30 [V], −50 when this pixel is the pixel in the first row. When the pixel changes in the order of [V] and this pixel is the pixel in the second row, −50 [V], 30 [V], −50 [V], 30 [V], −50 [V], 30 [ V] and −50 [V].

  On the other hand, the potential of the signal output from the column signal superimposing circuit 204 in this pixel driving period is roughly − in the first 5 [ms] period according to the row pixel driving signal for this pixel. 50 [V] and 50 [V] in the next 95 [ms] period. More specifically, in the vicinity of the head of the period of 95 [ms], it fluctuates in a short cycle according to the column coordinate signal for this pixel. The potential near the beginning of the period of 95 [ms] is, for example, 50 [V], −30 [V], 50 [V], −30 [V], 50 [ V], and when this pixel is a pixel in the second column, 50 [V], −30 [V], 50 [V], −30 [V], 50 [V], −30 [V ] And 50 [V]. In the column fluctuation period in which the potential fluctuates in a short cycle in the signal output from the column signal superposition circuit 204, the row fluctuation period in which the potential fluctuates in a short time in the signal output from the row signal superposition circuit 203 expires. Then it starts.

  The signal output from the row signal superimposing circuit 203 is applied to the row electrode 110 of the pixel, and the signal output from the column signal superimposing circuit 204 is applied to the column electrode 111 of the pixel. Therefore, for example, when the pixel to be driven is a pixel in the first row and first column, the voltage between the transparent electrode 101 and the electrode 102 of this pixel is constant at 100 [V] in a period of 5 [ms], and is 95 [ In the period of ms], in the period from the start to the end of the variable period for use, −100 [V], −20 [V], −100 [V], −20 [V], and −100 [V] -100 [V], -20 [V], -100 [V], -20 [V], -100 in the period from the expiration of the row variation period to the column variation period. It changes in the order of [V], and becomes -100 [V] constant for the remaining period. Since the period in which −100 [V] is constant is sufficiently long, the positive black particles 108 attached to the dielectric layer 104 move and adhere to the dielectric layer 106 in the period in which −100 [V] is constant. The negative white particles 109 attached to the dielectric layer 106 move and adhere to the dielectric layer 104. As a result, the color of this pixel is changed from white to black.

  If the pickup electrode A is in contact with the pixel while such driving is performed on the pixel, the current flowing through the resistor R connected to the pickup electrode A changes according to the third principle. To do. The third principle is a principle that combines the first principle and the second principle. According to the third principle, the combined electric field of the electric field formed by the first principle and the electric field formed by the second principle changes according to the waveform of the signal applied to the transparent electrode 101 and the electrode 102. A change corresponding to the change in the electric field occurs in the current flowing through the resistor R. The electric field detection device 120 sends an electric signal representing this change in current to the coordinate discrimination circuit 205. Of the electrical signals sent to the coordinate discrimination circuit 205, the signal obtained from the start of the 95 [ms] period and the signal output from the row signal superimposing circuit 203 during the row variation period is the row coordinate signal, row The electric signal obtained during the column fluctuation period is a waveform corresponding to the column coordinate signal, the column pixel drive signal, and the row pixel drive signal. Signal. The coordinate discrimination circuit 205 obtains row coordinates and column coordinates using these electric signals.

  Incidentally, in this case, the electrical signal determined by the coordinate discrimination circuit 205 that the waveform matches the waveform pattern is different in waveform from the electrical signal detected by the electric field detection device 120 when the color of the pixel is maintained. In this embodiment, the memory of the coordinate determination circuit 205 stores the waveform pattern for obtaining the row coordinates when the row pixel drive signal is constant at 0 [V] for one row coordinate, and the row pixel drive signal. A waveform pattern for obtaining the row coordinates when -50 [V] is constant, a waveform pattern for obtaining the row coordinates when the row pixel drive signal is 50 [V], and one column A waveform pattern for obtaining the column coordinates when the column pixel drive signal is constant 0 [V] with respect to the coordinates, and a waveform for obtaining the column coordinates when the column pixel drive signal is constant 50 [V]. A pattern and a waveform pattern for obtaining column coordinates when the column pixel drive signal is constant at −50 [V] are stored in advance. Therefore, the coordinate determination circuit 205 can obtain the row coordinate and the column coordinate even when the coordinate signal is superimposed on the pixel drive signal that is not constant at 0 [V].

  Further, for example, when driving the pixels other than the first row so that the color is changed from black to white, the signal output from the row signal superimposing circuit 203 during this pixel driving period is for this pixel. According to the row pixel drive signal, the first 5 [ms] period is −50 [V], and the next 95 [ms] period is 50 [V]. On the other hand, the signal output from the column signal superimposing circuit 204 during the pixel driving period is the same signal as driving the pixels in the first row so that the color is changed from black to white. As a result, the voltage between the transparent electrode 101 and the electrode 102 of this pixel is constant at 100 [V] in the period of 5 [ms] when this pixel is the pixel in the first column, and in the period of 95 [ms], In the period from the start to the end of the column variation period, the sequence changes in the order of −100 [V], −20 [V], −100 [V], −20 [V], −100 [V], and the rest In this period, −100 [V] is constant. Since the period in which −100 [V] is constant is sufficiently long, the color of this pixel is changed from white to black.

  If the pickup electrode A is in contact with the pixel while such driving is performed on the pixel, an electric signal is sent from the electric field detection device 120 to the coordinate determination circuit 205. Of these electrical signals, the electrical signal obtained during the column variation period is a signal having a waveform corresponding to the column coordinate signal, the column pixel drive signal, and the row pixel drive signal. The coordinate discriminating circuit 205 obtains column coordinates using this electrical signal.

As described above, according to this embodiment, the same effect as that obtained by the coordinate input device according to the first embodiment can be obtained. Note that the configuration of the coordinate input device according to the present embodiment can be made small and simple because the means to be newly installed when applying the coordinate input device to the image display device of the particle movement type is the line coordinate signal. This is because only the driving circuit 201, the column coordinate signal driving circuit 202, the row signal superimposing circuit 203, the column signal superimposing circuit 204, the electric field detection device 120, and the coordinate discrimination circuit 205 are provided.
According to the present embodiment, since the coordinate signal is superimposed on the pixel drive signal, it is not necessary to provide a dedicated period for outputting the coordinate signal.

[Third Embodiment]
[Constitution]
FIG. 13 is a diagram showing a configuration of a coordinate input device according to the third embodiment of the present invention, and FIG. 14 is a cross-sectional view showing a partial configuration of the coordinate input device. This coordinate input device is configured by effectively using the configuration of the applied image display device. Therefore, these figures also show the configuration of the image display device.

  An image display device to which the present coordinate input device is applied is a particle rotation type image display device as disclosed in Patent Document 2. This image display device is greatly different from the particle movement type image display device in the configuration of the portion where the image is formed. As shown in FIG. 14, the part where the image of the image display apparatus according to the present embodiment is formed includes the electrode 102, the dielectric layer 104 for protecting the electrode 102, and the spherical cavity 306 on the substrate 103. The transparent dielectric layer 106 for protecting the transparent electrode 101, the transparent electrode 101, and the transparent glass substrate 107 are laminated in that order.

  The sheet material 307 is formed by filling a space with an insulating material. However, the hollow portion 306 is not filled with this insulating material but with two kinds of high resistance liquids having different specific gravities. Further, a display sphere (particle) 308 which is a rotating particle is placed in the hollow portion 306. The material of the display sphere 308 is arbitrary, but its specific gravity is higher than that of one high-resistance liquid and lower than that of the other high-resistance liquid. Accordingly, the display sphere 308 floats in the cavity 306. In addition, the charged state of one hemisphere part constituting the display sphere 308 is different from the charged state of the other hemisphere part. Therefore, by controlling the voltage between the transparent electrode 101 and the electrode 102, the electric field in the space where the display sphere 308 exists is changed, and the orientation of the display sphere 308 floating in the cavity 306 is controlled. Can do. Further, the surface color (for example, black) of one hemispherical portion constituting the display sphere 308 and the surface color (for example, white) of the other hemispherical portion are different. Since the surface of the display sphere 308 facing the transparent electrode 101 is observed through the glass substrate 107, the transparent electrode 101, and the dielectric layer 106, the color of this surface becomes the color of this pixel. . That is, according to this image display device, the color of the pixel can be controlled by controlling the voltage between the transparent electrode 101 and the electrode 102.

  Due to the difference in the configuration of the part where the image is formed, the image display device according to the present embodiment is replaced with the row pixel driving circuit 112 and the column pixel driving circuit 113 in the second embodiment. The pixel driving circuit 301 for rows and the pixel driving circuit 302 for columns are provided. The coordinate input device according to the present embodiment basically has the same configuration as the coordinate input device according to the second embodiment, but due to the above differences, the row coordinate signal drive circuit. Instead of 201, the column coordinate signal drive circuit 202 and the coordinate determination circuit 205, a row coordinate signal drive circuit 303, a column coordinate signal drive circuit 304 and a coordinate determination circuit 305 are provided.

  This image display device drives pixels by a simple matrix driving method. The row pixel drive circuit 301 outputs a row pixel drive signal by changing the potential of the output terminal, and the column pixel drive circuit 302 A column pixel drive signal is output by changing the potential of the output terminal. The row pixel driving signal is applied to the row electrode 110 via the row signal superimposing circuit 203 and the row signal scanning circuit 114, and the column pixel driving signal is applied to the column signal superimposing circuit 204 and the column signal scanning circuit 115. Then, it is applied to the column electrode 111. Since both signals are for applying an electric field having an intensity corresponding to the potential difference between the two signals to the display sphere 308, the potentials of both signals differ depending on the color of the pixel. However, in this image display device, the intensity (absolute value) of the electric field to be applied to the display sphere 308 is the same regardless of the color of the pixel.

  FIG. 15 shows the intensity (absolute value) of the electric field applied to the display sphere 308 from the outside in this image display apparatus, and the response time until the display sphere 308 starts rotating when the electric field of that intensity is applied. It is a figure which shows the relationship. The voltage between the transparent electrode 101 and the electrode 102 and the application time corresponding to the electric field strength and response time satisfying the relationship shown in this figure are referred to as rotation start voltage and rotation start time. As shown in this figure, for example, even when an electric field having an intensity of 5 [KV / cm] or less is applied for a time of 200 [ms] or less, the display sphere 308 does not rotate. The relationship shown in the figure changes according to parameters such as the material and diameter of the display sphere 308 and the distance between the transparent electrode 101 and the electrode 102. However, even if the parameter changes, the response time becomes shorter if the applied electric field becomes stronger. The response time will be longer if it becomes weaker, the response time will not be zero no matter how strong the applied electric field is, and the applied electric field will not be less than zero no matter how long the response time is Is maintained.

  The row pixel drive circuit 301 and the column pixel drive circuit 302, when driving a pixel whose color is to be changed, satisfy a rotation start condition determined from the relationship between the rotation start voltage and the rotation start time. When the pixel driving signal for the column and the pixel for which the color is maintained are driven, the row pixel driving signal and the column pixel driving signal that do not satisfy the rotation start condition are output. Specifically, the row pixel drive circuit 301 and the column pixel drive circuit 302 obtain a voltage between the transparent electrode 101 and the electrode 102 when an electric field of 6 [KV / cm] is applied to the display sphere 308. A column for driving this pixel when the potential of a row pixel drive signal for driving a pixel having a specific color by changing the color is a [V] constant when a [V] is doubled. The potential of the pixel pixel driving signal is -a [V] constant, the potential of the row pixel driving signal for driving a pixel whose color is different from the specific color by changing the color is constant -a [V]. The potentials of the row pixel drive signal and the column pixel drive signal for driving the pixel whose color is maintained so that the potential of the column pixel drive signal for driving the pixel is constant a [V]. And the pixel drive signal for row for one pixel so that both are constant at 0 [V]. The length of and column pixel drive signals are designed together so that 210 [ms]. However, a is a positive value.

  The row coordinate signal drive circuit 303 outputs a row coordinate signal in parallel with the row pixel drive signal output by the row pixel drive circuit 301. The row coordinate signal is a signal obtained by connecting pulse signals (row [b] and 0 [V] sections) representing row coordinates for the number of pixel rows. However, b is a positive value. Each pulse signal constituting the row coordinate signal is output when the row pixel drive signal is first applied to the row electrode 110 of the corresponding row coordinate. For example, the pulse signal representing the row coordinates of the first row is output immediately after the output of the row pixel driving signal for driving the pixels of the first row and the first column is started, and is a pulse representing the row coordinates of the second row. The signal is output immediately after the output of the row pixel driving signal for driving the pixels in the second row and the first column is started.

  The column coordinate signal drive circuit 304 outputs a column coordinate signal in parallel with the column pixel drive signal output from the column pixel drive circuit 302. The column coordinate signal is a signal obtained by connecting pulse signals representing column coordinates (a signal in which a potential is −b [V] and a repetition of 0 [V]) by the number of columns of pixels. Each pulse signal constituting the column coordinate signal is output every time a column pixel drive signal is applied to the column electrode 111 of the corresponding column coordinate. For example, the pulse signal representing the column coordinate of the first column is a pulse corresponding to the row coordinate of the pixel being driven from when the output of the column pixel drive signal applied to the column electrode 111 of the first column is started. It is output immediately after the time of the length of the signal (pulse signal constituting the row coordinate signal) has elapsed. In the coordinate signal, the potential between the pulse signals is 0 [V].

  Although the length and the waveform of the pulse signal constituting the coordinate signal are basically arbitrary, in this embodiment, when the voltage is directly applied to the transparent electrode 101 and the electrode 102, the voltage between both electrodes and the application time thereof are When the relationship is superimposed on the pixel drive signal that satisfies the rotation start condition, the above relationship satisfies the rotation start condition and is directly applied to both electrodes when the superimposed signal is applied to both electrodes. If the above relationship is superimposed on a pixel drive signal that does not satisfy the rotation start condition when applied, the above relationship is the rotation start condition when the superimposed signal is applied to both electrodes. It is stipulated not to satisfy. By defining the coordinate signal in this way, it is ensured that no change in pixel color is caused by the use of the coordinate signal.

  The difference between the coordinate determination circuit 305 and the coordinate determination circuit 205 is only the waveform pattern stored in advance in the memory.

[Operation]
The operation of the coordinate input device having the above-described configuration will be described.
First, the image display device scans the screen and displays an image. At this time, the row pixel driving signal output from the row pixel driving circuit 301 and the column pixel driving signal output from the column pixel driving circuit 302 are both fixed to 0 [V] for the pixels for which the color is maintained. The row signal superimposing circuit 203 outputs a signal obtained by changing the potential of the row pixel driving signal according to the potential of the row coordinate signal, and the column signal superimposing circuit 204 converts the potential of the column pixel driving signal to the column. Since a signal obtained by changing according to the potential of the pixel coordinate signal is output, the row electrode 110 corresponding to the row coordinate of the pixel has the potential of the row coordinate signal for the pixel in the driving period of the pixel. A row inversion signal obtained by inverting the sign is also applied to the column electrode 111 corresponding to the column coordinate of the pixel, and a column inversion signal obtained by inverting the potential of the column coordinate signal for the pixel. Is applied.

  When this pixel is the pixel in the first column, the voltage between the transparent electrode 101 and the electrode 102 of this pixel is 0 [V], the potential of the row inversion signal, the potential of the column coordinate signal, and the order of 0 [V]. It changes with. Since the potentials of the row coordinate signal and the column coordinate signal are b [V] to −b [V] and the pulse period is sufficiently short, the intensity of the electric field applied to the display sphere 308 of this pixel during this period. The application time does not satisfy the rotation start condition. Therefore, the display sphere 308 does not rotate and the color of this pixel is maintained.

  While the drive is performed on the pixel, if the pickup electrode A is in contact with the pixel, the current flowing through the resistor R connected to the pickup electrode A changes. The electric field detection device 120 sends an electric signal representing this change to the coordinate determination circuit 305. This electric signal is a signal obtained by connecting a signal that changes according to the waveform of the row inversion signal and a signal that changes according to the waveform of the column coordinate signal. Subsequent operations are the same as those of the coordinate input device according to the second embodiment, and the coordinate determination circuit 305 obtains row coordinates using the former electrical signal and column coordinates using the latter electrical signal. it can.

  On the other hand, when the pixels other than the first column are driven so as to maintain the color, the row pixel drive signal, the column pixel drive signal, and the row coordinate signal related to this pixel are constant at 0 [V]. As a result, the voltage between the transparent electrode 101 and the electrode 102 of this pixel changes in the order of 0 [V], the potential of the column coordinate signal, and 0 [V]. Thereafter, an operation similar to the operation performed for the pixel in the first column is performed, and the color of this pixel is maintained. On the other hand, if the pickup electrode A is in contact with the glass substrate 107 of the pixel, the coordinate determination circuit 305 is used. To obtain column coordinates.

  When the pixel to be driven is a pixel whose color is changed, the row pixel drive signal output from the row pixel drive circuit 301 is constant a [V] or −a [V], and the column pixel drive circuit The column pixel drive signal output from 302 becomes -a [V] or a [V] constant. As a result, finally, regardless of whether this pixel is a pixel in the first column or another pixel, the voltage applied between the transparent electrode 101 and the electrode 102 of the pixel and the application time thereof are The relationship satisfies the rotation start condition. Therefore, the display sphere 308 rotates and the color of the pixel is changed.

  When this pixel is a pixel in the first column, the potential of the pulse signal for the pixel in the row coordinate signal is 0 [V], −b [V], 0 [V], −b [V],. To change. Therefore, in the signal output from the row signal superimposing circuit 203 for this pixel, the potential in the section corresponding to the length of the pulse signal is −a [V] or a [V], −a + b [V] or a -B [V], -a [V] or a [V], -a + b [V] or a-b [V],..., And the potential in the subsequent section is -a [V] or a [V] Constant.

  On the other hand, the pulse signal for the pixel in the column coordinate signal is output after the output of the pulse signal for the pixel in the row coordinate signal is completed, and the potential is 0 [V], b [V], 0 [ V], b [V],... Therefore, the potential of the signal output from the column signal superimposing circuit 204 for this pixel is constant a [V] or −a [V] in the section synchronized with the pulse signal for the pixel in the row coordinate signal. In a section synchronized with the pulse signal for the pixel in the coordinate signal for use, a [V] or -a [V], ab [V] or -a + b [V], a [V] or -a [V] , A−b [V] or −a + b [V],..., And a [V] or −a [V] is constant in the subsequent section.

  Therefore, the voltage between the transparent electrode 101 and the electrode 102 of this pixel is −2 · a [V] or 2 · a [V], −2 · a + b in the output period of the pulse signal for the pixel in the row coordinate signal. [V] or 2 · a−b [V], −2 · a [V] or 2 · a [V], −2 · a + b [V] or 2 · a−b [V], etc. In the period from the end of this period to the end of the output period of the pulse signal for the pixel in the column coordinate signal, −2 · a [V], 2 · a [V], −2 · a + b [ V] or 2 · a−b [V], −2 · a [V] or 2 · a [V], −2 · a + b [V] or 2 · a−b [V], and so on. Further, in the subsequent period, −2 · a [V] or 2 · a [V] is constant.

  When the pickup electrode A is in contact with this pixel, the current flowing through the resistor R connected to the pickup electrode A changes. The electric field detection device 120 sends an electric signal representing this change to the coordinate determination circuit 305. The first part of the electric signal is a signal having a waveform corresponding to the row coordinate signal, the row pixel drive signal, and the column pixel drive signal, and the latter part is the column coordinate signal, the column pixel drive signal, and the row pixel. The signal has a waveform corresponding to the drive signal.

  The coordinate discrimination circuit 305 stores three types of waveform patterns for one row coordinate and one column coordinate in the memory. The three types of waveform patterns include a waveform pattern for obtaining row coordinates or column coordinates using pixels whose color is maintained, and a line coordinate or column coordinates using pixels whose color is changed to a predetermined color. There are waveform patterns for obtaining row coordinates or column coordinates using pixels whose color is changed to a color other than a predetermined color. Therefore, the coordinate determination circuit 305 can obtain the row coordinates and the column coordinates using the electric signal passed from the electric field detection device 120.

  When this pixel is a pixel other than the first column, the potential of the pulse signal for the pixel in the row coordinate signal is constant at 0 [V]. Therefore, the potential of the signal output from the row signal superimposing circuit 203 for this pixel is constant -a [V] or a [V]. On the other hand, the signal output from the column signal superimposing circuit 204 for this pixel is the same as the signal output in the case of the first column described above.

  Therefore, the voltage between the transparent electrode 101 and the electrode 102 of this pixel is −2 · a [V] or 2 · a [[2] in the period until the output of the pulse signal for the pixel in the column coordinate signal is started. V] is constant, and in the period from the expiration of this period until the output of the pulse signal is completed, −2 · a [V] or 2 · a [V], −2 · a + b [V] or 2 · a −b [V], −2 · a [V] or 2 · a [V], −2 · a + b [V] or 2 · a−b [V],... Becomes -2 · a [V] or 2 · a [V] constant.

  If the pickup electrode A is in contact with this pixel, finally, an electric signal is sent from the electric field detection device 120 to the coordinate determination circuit 305. Among the electrical signals, the signals in the section from the start to the completion of the output of the pulse signal for the pixel in the column coordinate signal are the column coordinate signal, the column pixel drive signal, and the row pixel drive signal. Since the corresponding waveform signal is obtained, the coordinate determination circuit 305 can obtain the column coordinates.

  As described above, according to this embodiment, the same effect as that obtained by the coordinate input device according to the second embodiment can be obtained. Note that the configuration of the coordinate input device according to the present embodiment can be made small and simple because the means to be newly installed when applying the coordinate input device to the image display device of the particle rotation method is the line coordinate signal. This is because only the driving circuit 303, the column coordinate signal driving circuit 304, the row signal superimposing circuit 203, the column signal superimposing circuit 204, the electric field detection device 120, and the coordinate discrimination circuit 305 are provided.

  In each of the above-described embodiments, the pickup electrode A is brought into contact with the glass substrate 107 to indicate the position. However, the coordinates can be detected only by positioning the pickup electrode A in the vicinity of the glass substrate 107. Of course, if the pickup electrode A and the glass substrate 107 are not completely parallel but substantially parallel, coordinate detection is possible.

[Fourth Embodiment]
[Constitution]
FIG. 16 is a diagram showing a configuration of a coordinate input device according to the fourth embodiment of the present invention, and FIG. 17 is a cross-sectional view showing a partial configuration of the coordinate input device. The configuration of the image display device to which this coordinate input device is applied is the same as the configuration of the image display device according to the first embodiment. The configuration of this coordinate input device is different from the configuration of the coordinate input device according to the first embodiment only in that it has a magnetic field detection device 401 and a coordinate determination circuit 402 instead of the electric field detection device 120 and the coordinate determination circuit 121. is there.

  The magnetic field detection device 401 detects a change in the magnetic field in the vicinity of an instructed position, and includes a pen-shaped pickup 4011 and a signal detection circuit 4012. The pickup 4011 is held by a person who indicates a position, and generates an electric signal that changes in accordance with a change in the magnetic field in the vicinity of the specified position. F is built-in. The coil F is fixed so that its axial direction substantially coincides with the longitudinal direction of the pickup 4011. The signal detection circuit 4012 detects a change in the current flowing through the coil F and wirelessly transmits an electric signal representing the detected change to the coordinate determination circuit 402. Thus, since the coil F is for detecting a change in the magnetic field, the material of the tip portion of the pickup 4011 must be a material that transmits the magnetic lines of force. Of course, if the pickup 4011 is configured such that the coil F is exposed, such a restriction is eliminated. Although an example in which the pickup 4011 and the signal detection circuit 4012 are connected by a signal line is illustrated, the signal detection circuit 4012 actually exists in the pickup 4011.

  The difference between the coordinate determination circuit 402 and the coordinate determination circuit 121 is only that the electric signal passed from the magnetic field detection device 401 is used instead of the electric field detection device 120 and the waveform pattern stored in advance in the memory. The waveform pattern stored in advance in the memory of the coordinate discrimination circuit 402 is compared with the waveform of an electric signal representing how the current flowing through the coil F changes according to the change in the leakage magnetic field from the pixels near the coil F. Therefore, it is natural that the waveform pattern is different from the waveform pattern stored in advance in the memory of the electric field detection device 120. Note that the coordinate determination circuit 402 and the signal detection circuit 4012 may be provided in the pickup 4011.

[Operation]
The operation of the coordinate input device having the above-described configuration will be described by focusing on differences from the operation of the coordinate input device according to the first embodiment.
When the tip portion of the pickup 4011 is located in the vicinity of a pixel whose color is maintained, the voltage between the transparent electrode 101 and the electrode 102 of this pixel is constant at 0 [V] during the driving period of this pixel. In addition, virtually no current flows between both electrodes. Therefore, no magnetic field is generated around both electrodes, and no change occurs in the current flowing through the coil F in the tip portion of the pickup 4011. Therefore, the signal detection circuit 4012 does not send an electrical signal to the coordinate determination circuit 402. Therefore, coordinates are not obtained by the coordinate discrimination circuit 402.

  When the tip portion of the pickup 4011 is located in the vicinity of a pixel whose color is to be changed, the voltage between the transparent electrode 101 and the electrode 102 of this pixel is −100 [V] or 100 [V] during the driving period of this pixel. Since it is constant, current virtually flows between both electrodes. This virtually flowing current is called displacement current. In this specification, a current that is not a displacement current is a conduction current. When the displacement current flows, a magnetic field is generated around the transparent electrode 101 and the electrode 102. This magnetic field leaks into the sky above the glass substrate 107, that is, the air space where the tip of the pickup 4011 is located in FIGS. Hereinafter, the magnetic field leaking to the outside of the glass substrate 107 is referred to as a leakage magnetic field. Since the voltage between both electrodes is constant, the displacement current does not change. Therefore, the leakage magnetic field above this pixel does not change, and the current flowing through the coil F located in this leakage magnetic field does not change. Therefore, the signal detection circuit 4012 does not send an electrical signal to the coordinate determination circuit 402. Therefore, coordinates are not obtained by the coordinate discrimination circuit 402.

  FIG. 18 is a diagram showing a state of coordinate input by the coordinate input device. As shown in this figure, the coordinates are determined by the coordinate determination circuit 402 not in the pixel drive signal application period but in the coordinate signal application period. Hereinafter, as shown in this figure, it is assumed that the tip of the pickup 4011 is located in the vicinity of the pixels in the second row and third column.

  When the pulse signal R2 is applied to the row electrode 110 in the second row, the potential of the column electrode 111 in the third column during this period is constant 0 [V], so the transparent electrode 101 of the pixel in the second row and third column is constant. The voltage between the electrode 102 and the electrode 102 is 0 [V], −40 [V], 40 [V], −40 [V], 40 [V], −40 [V], 40 according to only the pulse signal R2. It changes in the order of [V] and 0 [V]. Therefore, the displacement current flowing between the transparent electrode 101 and the electrode 102 of this pixel changes, and the leakage magnetic field above this pixel changes. When the leakage magnetic field changes, the current flowing through the coil F located in the leakage magnetic field changes. The signal detection circuit 4012 detects this current change, and sends an electrical signal representing the detected current change as a waveform to the coordinate determination circuit 402. Since the voltage between the transparent electrode 101 and the electrode 102 of the pixel changes only in accordance with the pulse signal R2, the waveform of this electric signal relates to the second row of the waveform patterns stored in advance in the coordinate determination circuit 402. Match the waveform pattern. In this way, the row coordinates of this pixel are obtained as the coordinates of the position designated by the pickup 4011.

  When the pulse signal C3 is applied to the column electrode 111 of the third column, the voltage between the transparent electrode 101 and the electrode 102 of this pixel is 0 [V], 40 [V], − according to only the pulse signal C3. It changes in the order of 40 [V], 40 [V], −40 [V], 40 [V], −40 [V], 40 [V], −40 [V], and 0 [V]. As a result, the current flowing through the coil F positioned in the leakage magnetic field above the pixel changes eventually, and an electric signal representing the change in current as a waveform is sent from the signal detection circuit 4012 to the coordinate determination circuit 402. It is done. Since the voltage between the transparent electrode 101 and the electrode 102 of this pixel changes only according to the pulse signal C3, the waveform of this electrical signal is related to the third row of the waveform patterns stored in advance in the coordinate discrimination circuit 402. Match the waveform pattern. Thus, the column coordinates of this pixel are obtained as the coordinates of the position designated by the pickup 4011.

As described above, according to this embodiment, the same effect as that obtained by the coordinate input device according to the first embodiment can be obtained. However, the reason why the coordinates of the position on the screen can be obtained by the present embodiment is as follows.
According to the present embodiment, by applying a row coordinate signal to the row electrode 110 for driving the pixel and changing the voltage between the transparent electrode 101 and the electrode 102 in the pixel, the displacement current between both electrodes is changed. Thus, the leakage magnetic field above the pixel can be changed. At this time, if the coil F of the pickup 4011 exists in the leakage magnetic field, the change in the leakage magnetic field is converted into a current change by using the coil F and indirectly detected, and the row coordinate is obtained using the detection result. be able to. On the other hand, according to the present embodiment, a column coordinate signal is applied to the pixel drive column electrode 111, and the voltage between the transparent electrode 101 and the electrode 102 in the pixel is changed, whereby the displacement current between the two electrodes is reduced. It is possible to change the leakage magnetic field above the pixel. At this time, if the coil F of the pickup 4011 is present in the leakage magnetic field, the change in the leakage magnetic field is converted into a current change using the coil F and indirectly detected, and the column coordinate is obtained using the detection result. be able to. Thus, according to the present embodiment, it is possible to obtain the coordinates of the position on the screen indicated by using the pickup 4011 or the position in the vicinity thereof.

  In addition, the configuration of the coordinate input device according to the present embodiment can be made small and simple. This is because only the driving circuit 116, the column coordinate signal driving circuit 117, the row signal switching circuit 118, the column signal switching circuit 119, the magnetic field detection device 401, and the coordinate discrimination circuit 402 are provided.

  In the coordinate input device according to the present embodiment, since the detection target is a change in the leakage magnetic field, the distance between the coil F and the glass substrate 107 is longer than the coordinate input device in which the detection target is an electric field change. There is an advantage that coordinates can be obtained even if they are separated. Of course, according to the coordinate input device according to the present embodiment, even if the coil F and the glass substrate 107 are in contact with each other, even if the axial direction of the coil F and the glass substrate 107 are not perpendicular, the coordinates are obtained. Is possible.

  In the present embodiment, the change in the leakage magnetic field is detected using the coil F, but may be modified so as to be detected using a Hall element. This modification is also possible in the embodiments described later. This modification will be described below.

  FIG. 19 is a diagram for explaining a coordinate input device that detects a change in a leakage magnetic field using a Hall element. The difference between the coordinate input device shown in this figure and the coordinate input device according to the fourth embodiment is only that the magnetic field detection device 401 is provided instead of the magnetic field detection device 401. The magnetic field detection device 403 includes a pickup 4031 and a signal detection circuit 4032. The pickup 4031 is significantly different from the pickup 4011 in that the Hall element G is incorporated in the tip portion instead of the coil F. The Hall element G is provided so that its longitudinal direction is orthogonal to the longitudinal direction of the pickup 4031. The signal detection circuit 4032 is different from the signal detection circuit 4012 only in that a change in the Hall voltage generated in the Hall element G instead of the coil F is detected and a telegraph signal representing the detected change is sent to the coordinate determination circuit 402. However, the signal detection circuit 4032 outputs an electrical signal having the same waveform as that of the signal detection circuit 4012 if the row electrode 110 and the column electrode 111 to which the coordinate signal is applied are the same.

  In the coordinate input device having such a configuration, it is assumed that the position on the screen is instructed using the pickup 4031. In this case, the Hall element G in the pickup 4031 is located near a specific pixel. When a row coordinate signal is applied to the row electrode 110 corresponding to this pixel, the leakage magnetic field above this pixel changes. This change causes a change in the Hall voltage generated in the Hall element G located in the leakage magnetic field. The signal detection circuit 4012 detects this voltage change, and sends an electric signal representing the detected voltage change as a waveform to the coordinate determination circuit 402. Then, the coordinate determination circuit 402 obtains row coordinates. The column coordinates are also obtained by the same operation as described above. As apparent from the above, this coordinate input device detects a change in leakage magnetic field indirectly by converting it into a voltage change, not a current change.

[Fifth Embodiment]
FIG. 20 is a diagram showing the configuration of the coordinate input device according to the fifth embodiment of the present invention. The configuration of the image display device to which this coordinate input device is applied is the same as the configuration of the image display device according to the second embodiment. The only difference of the coordinate input device from the coordinate input device according to the second embodiment is that it has a magnetic field detection device 401 and a coordinate determination circuit 501 instead of the electric field detection device 120 and the coordinate determination circuit 205. . The configuration of the magnetic field detection device 401 is as described in the description of the fourth embodiment. The difference between the coordinate determination circuit 501 and the coordinate determination circuit 205 is only the point of using an electric signal passed from the magnetic field detection device 401 instead of the electric field detection device 120 and the waveform pattern stored in advance in the memory. The waveform pattern stored in advance in the memory of the coordinate discrimination circuit 501 is used for comparison with the waveform of an electric signal representing how the current flowing through the coil F changes according to the change in the leakage magnetic field from the pixels near the coil F. Used.

  The operation of the coordinate input device configured as described above is greatly different from the operation of the coordinate input device according to the second embodiment in that a change in leakage magnetic field is detected instead of an electric field change. Since it is clear from the description of the second embodiment and the description of the fourth embodiment that the change in the leakage magnetic field is detected by the coordinate input device and the coordinates are obtained by the coordinate determination circuit 501. Is omitted.

  According to this embodiment, the same effect as that obtained by the coordinate input device according to the second embodiment can be obtained. However, the configuration of the coordinate input device according to the present embodiment can be made small and simple because the means to be newly installed when applying the coordinate input device to the particle movement type image display device is the line coordinate signal. This is because only the driving circuit 201, the column coordinate signal driving circuit 202, the row signal superimposing circuit 203, the column signal superimposing circuit 204, the magnetic field detecting device 401, and the coordinate determining circuit 501 are provided. Further, according to the present embodiment, it is possible to obtain the same effect as that obtained by detecting the change in the leakage magnetic field instead of the change in the electric field in the fourth embodiment.

[Sixth Embodiment]
FIG. 21 is a diagram showing a configuration of a coordinate input device according to the sixth embodiment of the present invention, and FIG. 22 is a cross-sectional view showing a partial configuration of the coordinate input device. The image display device to which this coordinate input device is applied is a particle rotation type image display device, and the configuration thereof is the same as the configuration of the image display device according to the third embodiment. The only difference between this coordinate input device and the coordinate input device according to the third embodiment is that it has a magnetic field detection device 401 and a coordinate determination circuit 601 instead of the electric field detection device 120 and the coordinate determination circuit 305. . The configuration of the magnetic field detection device 401 is as described in the description of the fourth embodiment. The difference between the coordinate determination circuit 601 and the coordinate determination circuit 305 is only the use of an electric signal passed from the magnetic field detection device 401 instead of the electric field detection device 120 and a waveform pattern stored in advance in the memory. The waveform pattern stored in advance in the memory of the coordinate discrimination circuit 601 is used for comparison with a waveform of an electric signal representing a state in which a current flowing through the coil F changes according to a change in leakage magnetic field from a pixel near the coil F. Used.

  The operation of the coordinate input device configured as described above is significantly different from the operation of the coordinate input device according to the third embodiment in that a change in leakage magnetic field is detected instead of a change in electric field. The manner in which the change in the leakage magnetic field is detected by the coordinate input device and the manner in which the coordinates are obtained by the coordinate discrimination circuit 601 are clear from the description of the third embodiment and the description of the fourth embodiment. Is omitted.

  According to this embodiment, the same effect as that obtained by the coordinate input device according to the third embodiment can be obtained. However, the configuration of the coordinate input device according to the present embodiment can be made small and simple because the means to be newly installed when applying the coordinate input device to the image display device of particle rotation type is the coordinate signal for line This is because only the driving circuit 303, the column coordinate signal driving circuit 304, the row signal superimposing circuit 203, the column signal superimposing circuit 204, the magnetic field detection device 401, and the coordinate discrimination circuit 601 are provided. Further, according to the present embodiment, it is possible to obtain the same effect as that obtained by detecting the change in the leakage magnetic field instead of the change in the electric field in the fourth embodiment.

  In the above description, the coordinate input device according to the third embodiment and the sixth embodiment is exemplified as the coordinate input device applied to the particle rotation type image display device, but the first embodiment and the fourth embodiment are described. A coordinate input device in which the output timing of the pixel drive signal and the output timing of the coordinate signal do not overlap like the coordinate input device may be applied to a particle rotation type image display device.

  By the way, the coordinate input device according to the first embodiment, the second embodiment, the fourth embodiment, and the fifth embodiment inhibits the movement of particles between the transparent electrode 101 and the electrode 102 when driving the pixel whose color is changed. This is applied to an image display device that applies a voltage (for example, −100 [V]) in a direction that promotes movement after applying a voltage (for example, 100 [V]). These coordinate input devices may be modified so as to be applicable to a particle movement type image display device that does not apply a reverse voltage as disclosed in Japanese Patent Application Laid-Open No. 2001-31225.

  Further, in each of the embodiments described above, a pulse signal for the first row is applied to the row electrode 110 of the first row, and then a pulse signal for the second row is applied to the row electrode 110 of the second row,. As described above, a signal is applied to each row electrode 110 in a time-sharing manner. However, even if it is modified so that pulse signals for a plurality of rows can be simultaneously applied to the plurality of row electrodes 110. Good. The same applies to the column electrode 111.

In addition, the coordinate input device according to each of the above-described embodiments may be modified so that the potential and frequency of the row coordinate signal with different row coordinates are different, or the pulse signal representing the row coordinate is a bit representation of the row coordinate. It may be modified so as to be a pulse signal according to the above. The same applies to the column coordinate signal.
Further, the coordinate input device according to each of the embodiments described above may be modified so that the frequency of the row coordinate signal and the frequency of the column coordinate signal are different.

  Further, the coordinate input device according to the second embodiment, the third embodiment, the fifth embodiment, and the sixth embodiment performs only the coordinate signal after the screen scan is completed until the next scan is started. It may be modified so that it is applied to the electrode 110 and the column electrode 111 so that coordinates can be detected even in a period in which the pixel is not driven.

  In the second embodiment and the fifth embodiment, the coordinate signal is superimposed on the pixel drive signal while paying attention to the potential of the signal, but the method of superimposing is arbitrary. In short, in a pixel, a pixel drive signal for driving the pixel is modulated with a coordinate signal specific to the coordinate of the pixel, so that an electric field change or a magnetic field change specific to the coordinate is generated. What is necessary is just to modulate a drive signal with a coordinate signal. When this modulation is applied to a pixel drive signal in which the relationship between the voltage between the two electrodes and the application time satisfies the movement start condition when applied directly to the transparent electrode 101 and the electrode 102. When the modulated signal is applied to both electrodes, the above relationship satisfies the movement start condition, and when applied directly to both electrodes, the above relationship does not satisfy the movement start condition. When modulating the driving signal, if the above relationship is determined not to satisfy the movement start condition when the modulated signal is applied to both electrodes, the color change of the pixel is caused by the use of the coordinate signal. It is guaranteed that nothing will happen. These also apply to the third and sixth embodiments if the “movement start condition” is replaced with the “rotation start condition”.

  By the way, the coordinate input device according to each of the above-described embodiments is applied to an image display device that drives pixels by a simple matrix driving method. These coordinate input devices may be modified so that they can be applied to an image display device driven by another driving method such as an active matrix driving method or a static driving method.

  Further, according to each of the above-described embodiments, it is ensured that the color change of the pixel is not caused by the use of the coordinate signal. The coordinate signal may be determined without considering the conditions.

  The coordinate input device according to each of the embodiments described above is applied to a particle movement / rotation type image display device. These coordinate input devices may be modified so that they can be applied to other image display devices such as a liquid crystal display. However, since the coordinate input device according to each embodiment detects a coordinate by detecting a change in an electric field or a magnetic field, an applicable image display device is preferably a particle movement / rotation type image display device. Thus, an image display device in which a change in electromagnetic field is likely to appear in the airspace on the screen, and at least controls the voltage between a pair of electrodes constituting the pixel forming the screen on which the image is displayed. The image display device must control the color of the pixel.

It is a figure which shows the structure of the coordinate input device which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the structure of a part of the coordinate input device. It is a figure which shows the relationship between the movement start voltage and the movement start time of the positive polarity black particle 108 in the image display apparatus to which the coordinate input device is applied. It is a figure which shows the output timing of the pixel drive signal for rows, the pixel drive signal for columns, the coordinate signal for rows, and the coordinate signal for columns in 1st Embodiment of this invention. It is a figure which shows a mode that a coordinate signal is applied to an electrode in 1st Embodiment of this invention. It is a figure which shows the mode of the coordinate input by the coordinate input device which concerns on 1st Embodiment of this invention. It is a figure which shows a mode in case the signal detection circuit 1202 of the same coordinate input device outputs the electric signal showing a row coordinate. It is a figure which shows a mode in case the signal detection circuit 1202 outputs the electrical signal showing a column coordinate. It is a figure for demonstrating the coordinate input device which detects an electric field change using a liquid crystal element. It is a figure which shows the structure of the coordinate input device which concerns on 2nd Embodiment of this invention. It is a figure which shows the output timing of the pixel drive signal for rows, the pixel drive signal for columns, the coordinate signal for rows, and the coordinate signal for columns in 2nd Embodiment of this invention. It is a figure which shows the waveform of the signal output from the signal superimposing circuits 203 and 204 for rows of the coordinate input device concerning 2nd Embodiment of this invention. It is a figure which shows the structure of the coordinate input device which concerns on 3rd Embodiment of this invention. It is sectional drawing which shows the structure of a part of the coordinate input device. It is a figure which shows the relationship between the intensity | strength of an electric field and response time in the image display apparatus to which the same coordinate input device is applied. It is a figure which shows the structure of the coordinate input device which concerns on 4th Embodiment of this invention. It is sectional drawing which shows the structure of a part of the coordinate input device. It is a figure which shows the mode of the coordinate input by the coordinate input device. It is a figure for demonstrating the coordinate input device which detects the change of a leakage magnetic field using a Hall element. It is a figure which shows the structure of the coordinate input device which concerns on 5th Embodiment of this invention. It is a figure which shows the structure of the coordinate input device which concerns on 6th Embodiment of this invention. It is sectional drawing which shows the structure of a part of the coordinate input device. It is a top view which shows the example of a structure of the conventional coordinate input device which detects a coordinate using an optical system. It is AA 'sectional drawing of FIG. It is sectional drawing which shows the structural example of the conventional coordinate input device which detects a coordinate using a touchscreen.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Transparent electrode, 102 ... Electrode, 110 ... Row electrode, 111 ... Column electrode, 112, 301 ... Row pixel drive circuit, 113, 302 ... Column pixel drive circuit, 116, 201, 303 ... Row coordinate signal drive Circuit, 117, 202, 304 ... Column coordinate signal drive circuit, 118 ... Row signal switching circuit, 119 ... Column signal switching circuit, 120, 122 ... Electric field detection device, 121, 205, 305, 402, 501, 601 ... Coordinate discriminating circuit, 203 ... Row signal superimposing circuit, 204 ... Column signal superimposing circuit, 401, 403 ... Magnetic field detecting device.

Claims (8)

A coordinate signal that applies a coordinate signal representing the coordinates of the pixel to the electrode of the image display device that controls the color of the pixel by controlling the voltage between a pair of electrodes that form a pixel that forms a screen on which an image is displayed A drive circuit;
A detection device that is used to indicate a position on the screen and detects a change in an electric field or a magnetic field at or near the indicated position;
A coordinate input device, comprising: a coordinate determination circuit that detects the coordinates based on a change detected by the detection device. A transparent electrode provided substantially in parallel with the screen at the back of the screen on which an image is displayed and an electrode provided in parallel with the screen at the back of the transparent electrode are formed to form the screen. When driving a pixel, a voltage between the electrodes is controlled by applying a pixel driving signal corresponding to the driving content of the pixel to at least one of the transparent electrode and the electrode constituting the pixel. An image for controlling the color of the pixel on the screen by moving or stationary particles having a color on the surface between the electrodes or rotating or stationary particles having a region for each color on the surface. A coordinate signal drive circuit that applies a coordinate signal representing coordinates of the pixel constituted by the transparent electrode and the electrode to at least one of the transparent electrode and the electrode of the display device;
A detection device that is used to indicate a position on the screen and detects a change in an electric field or a magnetic field at or near the indicated position;
A coordinate input device, comprising: a coordinate determination circuit that detects the coordinates based on a change detected by the detection device. The image display device is a device that moves or stops particles having a color on the surface between the electrodes when driving the pixels,
The coordinate signal drive circuit applies the coordinate signal to the electrode so that a period in which the pixel drive signal is applied to the electrode and a period in which the coordinate signal is applied to the electrode do not overlap each other.
The coordinate signal is based on the relationship between the voltage applied between the electrodes when the coordinate signal is applied to the electrodes and the application time of the movement start voltage and the movement start time at which the particles start moving. The coordinate input device according to claim 2, wherein the signal does not satisfy a movement start condition determined from a relationship. The image display device is a device that rotates or stops particles having an area for each color on the surface when driving the pixels,
The coordinate signal drive circuit applies the coordinate signal to the electrode so that a period in which the pixel drive signal is applied to the electrode and a period in which the coordinate signal is applied to the electrode do not overlap each other.
The coordinate signal is based on the relationship between the voltage applied between the electrodes when the coordinate signal is applied to the electrodes and the application time of the rotation start voltage and the rotation start time at which the particles start rotating. The coordinate input device according to claim 2, wherein the signal does not satisfy a rotation start condition determined from a relationship. A coordinate signal drive circuit that outputs a coordinate signal representing the coordinates of pixels forming a screen on which an image is displayed;
The pixel driving applied to the electrodes of the image display device that controls the voltage between the electrodes by applying a pixel driving signal to a pair of electrodes constituting the pixels forming the screen to control the color of the pixels A signal superimposing circuit for modulating a signal with the coordinate signal output from the coordinate signal driving circuit for the pixel corresponding to the pixel driving signal, and applying the modulated signal to the electrode instead of the pixel driving signal;
A detection device that is used to indicate a position on the screen and detects a change in an electric field or a magnetic field at or near the indicated position;
A coordinate input device, comprising: a coordinate determination circuit that detects the coordinates based on a change detected by the detection device. A coordinate signal drive circuit that outputs a coordinate signal representing the coordinates of pixels forming a screen on which an image is displayed;
A substantially transparent transparent electrode provided substantially parallel to the screen at the back of the screen and an electrode provided substantially parallel to the screen at the back of the transparent electrode, and drives pixels forming the screen Occasionally, a pixel drive signal corresponding to the drive content of the pixel is applied to at least one of the transparent electrode and the electrode constituting the pixel to control the voltage between the electrodes, and enclosed in the gap between the electrodes In the image display apparatus for controlling the color of the pixel on the screen by moving or stationary the particles having a color on the surface between the electrodes or rotating or stationary the particles having a region for each color on the surface. A pixel drive signal is modulated with the coordinate signal output from the coordinate signal drive circuit for the pixel corresponding to the pixel drive signal, and the modulated signal is replaced with the pixel drive signal and the corresponding transparent electrode and A signal superposing circuit for applying to at least one of the fine said electrodes,
A detection device that is used to indicate a position on the screen and detects a change in an electric field or a magnetic field at or near the indicated position;
A coordinate input device, comprising: a coordinate determination circuit that detects the coordinates based on a change detected by the detection device. The image display device is a device that moves or stops particles having a color on the surface between the electrodes when driving the pixels,
When the coordinate signal is applied to at least one of the transparent electrode and the electrode, a pixel drive signal whose relationship between the voltage between the electrodes and the application time satisfies the movement start condition is modulated by the coordinate signal. When applied to at least one of the transparent electrode and the electrode, the relationship between the voltage between the electrodes and the application time satisfies the movement start condition, and is applied to at least one of the transparent electrode and the electrode. Then, when the pixel drive signal whose relationship between the voltage between the electrodes and the application time does not satisfy the movement start condition is modulated by the coordinate signal and applied to at least one of the transparent electrode and the electrode The relationship between the voltage between the electrodes and the application time does not satisfy the movement start condition,
The coordinate input device according to claim 6, wherein the movement start condition is a condition determined from a relationship between a movement start voltage at which the particles start moving and a movement start time. The image display device is a device that rotates or stops particles having an area for each color on the surface when driving the pixels,
When the coordinate signal is applied to at least one of the transparent electrode and the electrode, a pixel drive signal whose relationship between the voltage between the electrodes and the application time satisfies the rotation start condition is modulated by the coordinate signal. When applied to at least one of the transparent electrode and the electrode, the relationship between the voltage between the electrodes and the application time satisfies the rotation start condition, and is applied to at least one of the transparent electrode and the electrode. Then, when a pixel drive signal whose relationship between the voltage between the electrodes and the application time does not satisfy the rotation start condition is modulated by the coordinate signal and applied to at least one of the transparent electrode and the electrode The relationship between the voltage between the electrodes and the application time does not satisfy the rotation start condition,
The coordinate input device according to claim 6, wherein the rotation start condition is a condition determined from a relationship between a rotation start voltage at which the particles start to rotate and a rotation start time.

Images