JP2009199204A - Electro-optical device, control method thereof, and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely detect a touch without degrading display quantity. <P>SOLUTION: An electro-optical device 1 is provided. The device 1 includes a plurality of pixel circuits P1; a plurality of light detection circuits O1 with photodiodes 11; and a display detection control circuit 50. The circuit 50 reads detection signals from the plurality of circuits O1, detects, as an adjacent area, an area located within a predetermined distance from a screen and located behind an object approaching the screen among a plurality of unit detection areas one-to-one corresponding to the circuits O1 on the basis of the levels of the read detection signals and a threshold, and controls electronic energy to be supplied to the plurality of circuits P1 so as to display a monochrome image in the pixel area corresponding to the detected adjacent area. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electro-optical device that detects that an object such as a finger or a pen has touched a screen, a control method thereof, and an electronic apparatus including the electro-optical device.

  Patent Document 1 describes a liquid crystal display device that detects a coordinate position on a screen designated by an object. This liquid crystal display device includes a backlight, and has one optical sensor (image reading sensor 33) that captures the light of the backlight reflected by the object, one for each pixel or plurality of pixels. The coordinate position is detected based on the change in the imaging data when the is brought close to or in contact with the screen.

Japanese Patent Laid-Open No. 2004-228561 detects the coordinate position in consideration of surrounding light and dark, and determines the luminance of a predetermined part or all of the screen between the highest luminance (white raster) and the lowest luminance (black raster). The difference of the imaging data when changing every frame between frames, or displaying a special pattern such as black and white checkered pattern on a predetermined part or all of the screen, and searching for the special pattern in the image of the imaging data Thus, it is described that the influence of noise light (environmental light) is eliminated.
JP 2004-318819 A

  By the way, in order to detect the touch of the target object on the screen, that is, the touch with high accuracy, it is necessary to sufficiently eliminate the influence of the noise light. Of course, as described in Patent Document 1, a predetermined part or all of the color (luminance) of the screen is changed for each frame between white (maximum luminance) and black (minimum luminance), or a black and white checkered pattern. If a special pattern such as a pattern is displayed on a predetermined part or all of the screen, the influence of noise light can be sufficiently eliminated. However, since an image to be shown to a person is usually displayed on the screen, the above-described method may cause the image to flicker in a wide area visible on the screen, or a special pattern may overlap the image in the area. As a result, the screen becomes difficult to see. That is, display quality is impaired.

  The present invention has been made in view of the above-described circumstances, and an electro-optical device that can accurately detect a touch without impairing display quality, a control method thereof, and an electron including the electro-optical device Providing equipment is a problem to be solved.

First, terms will be explained.
An “electro-optical element” is an element whose light emission characteristics or light transmission characteristics change depending on applied electric energy. Light emission such as a light valve element such as a liquid crystal element or an OLED (Organic Light Emitting Diode). Including elements. An “optical sensor” is a sensor that converts light energy into electrical energy, and generates an electric current corresponding to the amount of light received (incident) or changes in electric resistance value depending on the intensity of light received (incident). Including things. As an optical sensor that generates a current corresponding to the amount of light, a photodiode can be exemplified. As an optical sensor whose electric resistance value changes according to the light intensity, a photoresistor can be exemplified.
The “target object” is an object that reflects light, and includes an object that indicates a coordinate position on the screen, such as a finger or a pen.

Next, means provided by the present invention for solving the above-described problems will be described.
The present invention is arranged in a unit circuit region extending along a planar screen having a plurality of pixel regions and a plurality of detection unit regions corresponding to the plurality of pixel regions in a fixed number of one-to-one, and the plurality of pixel regions A plurality of electro-optical elements each having a light emission characteristic or a light transmission characteristic that change according to applied electric energy, and emits light from the electro-optical element from the corresponding pixel region. Each of the pixel circuits and the unit circuit area, and has a one-to-one correspondence with the plurality of detection unit areas, each of which includes a photosensor, and outputs a detection signal at a level corresponding to the incident light to the detection unit area A plurality of photodetection circuits to be generated and a display control process for controlling the electric energy applied to the plurality of pixel circuits to display an image on the screen are repeatedly performed, and before the plurality of photodetection circuits A detection signal is read out, and based on the level and threshold value of the read detection signal, one of the plurality of unit detection areas that falls behind a target whose distance from the screen is within a predetermined distance range A display detection control circuit that repeatedly performs a detection process for detecting a proximity area, and the display detection control circuit uses the given image data when the proximity area is not detected in the display control process. When the displayed image is displayed on the screen and the adjacent area is detected, a monochrome image is displayed in the pixel area corresponding to the adjacent area among the plurality of pixel areas, and the remaining pixels The control is performed so that an image obtained by excluding a portion corresponding to the adjacent region from the image represented by the image data is displayed in the region. In the detection processing, the previous detection processing is performed. When the proximity region is detected, contact between the object and the screen is detected based on the level of the detection signal read from the plurality of light detection circuits. An optical device is provided.
According to this electro-optical device, a monochrome image is displayed only in a region that falls behind the object whose distance from the screen is within a predetermined distance range among the plurality of detection unit regions. It is possible to detect the touch with high accuracy without impairing the touch.

  In the above electro-optical device, the object may be only the object approaching the screen among the objects within the distance range. According to the electro-optical device of this aspect, when the object moves away from the screen, a monochrome image is not displayed. Therefore, useless display of black and white images can be eliminated.

  In each of the electro-optical devices, the black and white image may be an image having a white area and a black area. The black and white image may be a white image or white area or The entire area is a black black image, and the display detection control circuit converts the black and white image between the white image and the black image after the proximity area is detected until the proximity area is not detected. The switching process in which the switching process is performed at the repetition cycle of the detection process may be continued. In the former mode, it is possible to detect contact with a single detection, and in the latter mode, it is possible to detect contact by eliminating the influence of noise light (environmental light).

  In each of the electro-optical devices described above, the proximity region may include the plurality of unit detection regions that include all of the unit detection regions that are included in the shade and not include those that do not enter the shadow. . According to this aspect, the possibility that a black and white image is visually recognized can be reduced. Further, in each of the electro-optical devices described above, the certain number may be plural. According to this aspect, implementation becomes easy and the accuracy of contact detection improves.

  The present invention also provides an electronic apparatus including each of the electro-optical devices described above. According to this electronic apparatus, it is possible to accurately detect a touch without impairing display quality.

  Further, the present invention is arranged in a unit circuit region extending along a planar screen having a plurality of pixel regions and a plurality of detection unit regions corresponding to the plurality of pixel regions in a certain number of one-to-one, One-to-one correspondence with the pixel region, each having an electro-optical element whose light emission characteristic or light transmission characteristic changes according to the applied electric energy, and emits light from the electro-optical element from the corresponding pixel area A plurality of pixel circuits, arranged in the unit circuit region, corresponding to the plurality of detection unit regions on a one-to-one basis, each having a photosensor, and detecting a level according to light incident on the detection unit region An electro-optical device control method comprising a plurality of light detection circuits for generating a signal, wherein a display control process for controlling an electric energy applied to the plurality of pixel circuits to display an image on the screen is repeated. The detection signal is read out from the plurality of light detection circuits, and the distance from the screen among the plurality of unit detection areas is determined in advance based on the level and threshold value of the read detection signal. In the display control process, when the proximity area is not detected, the detection process of detecting the object behind the target object within the distance range is repeatedly performed, and is represented by the given image data. A black and white image is displayed in the pixel area corresponding to the proximity area, and the remaining pixel areas are displayed in the pixel area of the plurality of pixel areas. The control is performed so that an image obtained by removing a portion corresponding to the proximity region from the image represented by the image data is displayed. An electro-optic that detects contact between an object and the screen based on a level of the detection signal read from the plurality of light detection circuits when a proximity region is detected. An apparatus control method is provided. According to this control method, it is possible to accurately detect a touch without impairing display quality.

<1. First Embodiment>
FIG. 1 is a block diagram showing a configuration of an electro-optical device 1 according to the first embodiment of the present invention. The electro-optical device 1 is a transmissive liquid crystal display device having a touch input function, and includes a liquid crystal panel AA, a control circuit 300, and an image processing circuit 400. In the liquid crystal panel AA, an element substrate on which a thin film transistor is formed as a switching element and a counter substrate are attached to each other with the electrode forming surfaces facing each other and maintaining a certain gap. It is pinched. The liquid crystal panel AA includes a unit circuit region A, a scanning line driving circuit 100, a data line driving circuit 200, a sensor scanning circuit 500, and a detection signal reading circuit 600 on the element substrate. The above circuits 100 to 600 function as a display detection control circuit 50 that controls display and detection for touch input in cooperation.

  FIG. 2 is a conceptual diagram showing a functional configuration of the display detection control circuit 50. The display detection control circuit 50 is divided into a display control unit 51 that controls display and a detection control unit 52 that controls detection. The display control unit 51 is realized by the scanning line driving circuit 100, the data line driving circuit 200, the control circuit 300, and the image processing circuit 400, and the detection control unit 52 is the control circuit 300, the sensor scanning circuit 500, and the detection signal readout circuit. 600. The control circuit 300 controls display using the scanning line driving circuit 100, the data line driving circuit 200, and the image processing circuit 400, while controlling detection using the sensor scanning circuit 500 and the detection signal readout circuit 600. Based on the result of the process in the control unit 52, the content of the process performed by the display control unit 51 is determined.

  The unit circuit area A in FIG. 1 is an area that overlaps the screen and extends along the screen. In the unit circuit region A, m scanning lines extending in the X direction and n data lines extending in the Y direction are formed, and m corresponding to the intersection of the scanning lines and the data lines. (Row) × n (column) pixel circuits (display unit circuits) P1 are arranged. The pixel circuit P1 includes a liquid crystal element whose light transmission characteristics are changed by applied electric energy.

  The control circuit 300 supplies a clock signal and various control signals to the scanning line driving circuit 100 and the data line driving circuit 200. Further, the control circuit 300 supplies input image data Din supplied from an upper unit such as a CPU (Central Processing Unit) (not shown) to the image processing circuit 400. The image processing circuit 400 performs image processing on the input image data Din to generate output image data Dout, and outputs this to the data line driving circuit 200. The scanning line driving circuit 100 sequentially and cyclically selects the pixel circuits P1 arranged in a matrix along the screen in units of rows using the scanning signals Y1, Y2,. In addition, the data line driving circuit 200 supplies data signals X1, X2, X3,..., Xn to one row (n) of pixel circuits P1 sequentially selected by the scanning line driving circuit 100. Although not shown, a backlight is provided on the back surface of the liquid crystal panel AA, and light from the backlight is emitted from the planar screen to the outside via the unit circuit region A.

  The unit circuit area A overlaps the screen in the normal direction of the screen. The screen includes m (rows) × n (columns) pixel regions and m (rows) × n (columns) photodetection regions. The pixel circuit P1 has a one-to-one correspondence with the pixel region, and emits light from the liquid crystal element from the corresponding pixel region. On the other hand, the light transmittance (transmission characteristics) of the liquid crystal element is controlled for each pixel circuit P 1 according to the voltage level of the data signal supplied from the data line driving circuit 200. Thereby, gradation display by light modulation, that is, display of an image on the screen is possible. That is, the display control unit 51 repeatedly performs a display control process for controlling the electrical energy applied to the m × n pixel circuits P1 and displaying an image on the screen.

  Further, in the unit circuit area A, a photodetection circuit O1 is provided for each pixel circuit P1 for touch input, and a total of m (row) × n (column) photodetection circuits O1 are arranged in a matrix. Has been. The photodetection circuit O1 includes a photodiode (photosensor) that outputs a light reception signal at a level corresponding to the amount of incident light, has a one-to-one correspondence with the detection unit region, and the light from the outside of the electro-optical device 1 A detection signal having a signal level corresponding to light incident on the detection unit region corresponding to the detection circuit O1 (light reception light of the photodiode of the light detection circuit O1) is generated. The photodetection circuit O1 is electrically connected to the sensor scanning circuit 500 and the detection signal readout circuit 600.

  The control circuit 300 supplies a clock signal and a scanning control signal to the sensor scanning circuit 500, and supplies a clock signal and a detection signal processing control signal to the detection signal reading circuit 600. The control signal for detection signal processing includes a sampling signal SHG described later. The sensor scanning circuit 500 sequentially and cyclically selects the light detection circuits O1 arranged in a matrix along the screen in units of rows using the sensor scanning signals W1, W2,. Further, the detection signal readout circuit 600 reads out the detection signals Z1, Z2, Z3,..., Zn from one row (n) of photodetection circuits O1 sequentially selected by the sensor scanning circuit 500, and the control circuit 300 To supply.

  The control circuit 300 includes a memory (not shown), and sequentially stores the supplied detection signals in the memory. In addition, when the detection signal for one screen is accumulated, the control circuit 300 determines the distance from the screen among the m × n detection unit areas each time a new detection signal for one screen is accumulated. A region that falls within the proximity range and falls behind the finger approaching the screen is detected as an approach region. Hereinafter, this detection is referred to as “approach area detection”. The proximity range is a range of the distance between the screen and the finger when the finger can be regarded as being close to or in contact with the screen, and is determined in advance. That is, the display control unit 52 repeatedly performs the detection process of reading the detection signals from the plurality of light detection circuits O1 and performing the approach area detection. In summary, the display detection control circuit 50 repeatedly performs the above-described display control process and the above-described detection process.

  Further, the display detection control circuit 50 displays an image represented by the input image data Din on the screen when the approaching area is not detected in the immediately preceding detection process in each display control process. When an approaching area is detected, a black-and-white image is displayed in the pixel area corresponding to these approaching areas among the m × n pixel areas, and is represented by the input image data Din in the remaining pixel areas. The electric energy applied to the m × n pixel circuits P1 is controlled so that an image excluding a portion corresponding to these approach regions is displayed from the image to be displayed. Note that the image data of the monochrome image (hereinafter referred to as “monochrome image data”) is stored in the memory of the control circuit 300.

  In addition, the display detection control circuit 50 detects p × q detection signals read from the p × q light detection circuits O1 only when an approach region is detected in the previous detection process in each detection process. Is used to detect the contact and position of the finger on the screen. Hereinafter, this detection is referred to as “contact detection”. Next, specific contents of the detection process and the display control process will be described in order. First, the configuration and operation of the photodetection circuit O1 will be described.

[Configuration and Operation of Photodetection Circuit O1]
FIG. 3 is a circuit diagram illustrating a configuration of the light detection circuit O1 in the electro-optical device 1. The photodetection circuit O1 is arranged in the i (i is an integer satisfying 1 ≦ i ≦ m) row j (j is an integer satisfying 1 ≦ j ≦ n), but the other photodetection circuits O1 are similarly arranged. It is configured. The photodetection circuit O1 includes a photodiode 11. The photodiode 11 outputs a current having a magnitude corresponding to the amount of incident light, and functions as an optical sensor that converts light energy into electrical energy. The anode (first terminal) of the photodiode 11 is connected to a fixed potential, and its cathode is connected to the gate of the amplification transistor 12. Further, a capacitive element 14 is provided between the gate of the amplification transistor 12 and the first power supply line 13 to which the first power supply potential Vss is supplied. Charges output from the photodiode 11 are accumulated in the capacitive element 14. A reset transistor 16 is provided between the gate of the amplification transistor 12 and the second power supply line 15 to which the second power supply potential Vdd is supplied. Vdd> Vss. The reset transistor 16 functions as a switching element, and supplies the potential of the second power supply line 15 to the gate of the amplification transistor 12 when the sensor scanning signal Wi becomes active. Further, the drain of the amplification transistor 12 is electrically connected to the first power supply line 13, while its source is electrically connected to the detection line 17. Note that the relationship between the drain and the source in the amplification transistor 12 is defined as the drain having the higher potential and the source having the lower potential, so that the drain and the source may be reversed depending on the bias.

  FIG. 4 is a timing chart showing waveforms of the sensor scanning signals W1 to Wm and the sampling signal SHG. 5 and 6 are diagrams showing the state of the photodetection circuit O1 at a certain point in time. As shown in FIG. 4, the sensor scanning signals W1 to Wm sequentially become high level during a part of each horizontal scanning period (1H). The i-th horizontal scanning period includes an initialization period Tini, a detection period Tdet, and a reading period Tread.

  In the initialization period Tini, the second power supply potential Vdd is supplied to the n detection lines 17. Further, during this period, since the sensor scanning signal Wi is at a high level, the reset transistor 16 is turned on in the n photodetection circuits O1, and the second power supply potential Vdd is set to the second level as shown in FIG. The power is supplied to the gate of the amplification transistor 12 through the power line 15 and the reset transistor 16. That is, the voltage Vss−Vdd is stored in the capacitor 14 in the n light detection circuits O1.

  In the detection period Tdet, the second power supply potential Vdd is not supplied to the n detection lines 17. Further, during this period, since the sensor scanning signal Wi is at a low level, the reset transistor 16 is turned off in the n light detection circuits O1. Among the n photodetection circuits O1, the bias in the photodetection circuit O1 in the j-th column is as shown in FIG. That is, the gate potential Vg of the amplifying transistor 12 is Vg = Vdd−Vpd when the voltage of the photodiode 11 is Vpd. The voltage Vpd is determined according to the amount of light incident on the photodiode 11, and a current determined according to the gate potential is output to the detection line 17. When the potential of the detection line 17 is Vsense, the potential Vsense rises until the amplification transistor 12 is turned off, that is, until Vsense = Vg−Vth. Thus, the detection signal Zj is generated. Such an operation is performed by the n light detection circuits O1, and n detection signals Z1 to Zn are generated.

  In the reading period Tread, since the sampling signal SHG is at a low level, the detection signal reading circuit 600 reads n detection signals from the n detection lines 17. The read detection signal is supplied to the control circuit 300. In this way, a detection signal for one screen is supplied to the control circuit 300 every vertical scanning period (1 V). Next, the concept of approach area detection and contact detection will be described. In this description, one detection unit area to be noted is referred to as “attention area”.

[Approach area detection concept]
In the electro-optical device 1, the amount of incident light (total incident light amount) to the attention area includes the amount of ambient light incident on the attention area (incident environment light amount) and the backlight reflected to the finger and incident on the attention area. It is the sum of the light quantity (incident reflected light quantity). However, when the finger is close to or in contact with the region of interest, the total incident light amount is equal to the incident reflected light amount. If the finger is not in contact with or close to the screen, the total incident light amount is equal to the incident environment light amount, or the total incident light amount is equal to the incident environment light amount.

  On the other hand, when the finger approaches the region of interest while casting a shadow, the amount of incident environment light decreases while the amount of incident reflected light increases. As described above, when the finger is not in contact with or close to the region of interest, the total incident light amount is approximately equal to the incident environmental light amount. Therefore, the total incident light amount is reduced by the approach of the finger unless the ambient light is extremely weak. . In addition, as described above, when the finger is close to or in contact with the screen, the total incident light amount is equal to the incident reflected light amount. Incident light quantity increases.

  On the other hand, when the finger moves away from the region of interest while casting a shadow on the region of interest, the incident environment light amount increases while the incident reflected light amount decreases. That is, the change is opposite to that in the approach. Therefore, when the finger is close to or in contact with the region of interest, the total incident light amount is reduced by moving the finger away from the screen unless the light emitted from the region of interest is extremely weak. If the ambient light is not extremely weak, the total incident light amount increases as the finger moves away from the screen.

  When the finger is close to or in contact with the screen, the vicinity of the center of the screen where the shadow of the finger is dropped becomes bright and the vicinity of the periphery becomes dark. This is because the amount of incident reflected light near the center is large and the amount of incident reflected light near the periphery is small. As described above, when the number of detection unit areas where the total incident light quantity is sufficiently large and the increase rate of the total incident light quantity is sufficiently large is within the predetermined area number range, these detection unit areas are defined as the approach areas. You can see that.

[Concept of contact detection]
By the way, if contact is detected even though it is not in contact, or if a position different from the contacted position is detected as the contact position, the reliability of the electro-optical device 1 is significantly impaired. Therefore, contact detection requires higher accuracy than approach region detection. For example, even when the ambient light is extremely weak, it is necessary to accurately detect the contact of the finger on the screen and the contact position. As described above, a black and white image with a special pattern in which the entire area is white (maximum luminance) and the entire area is black (minimum luminance), such as a black and white checkerboard pattern, is displayed on the screen for image processing. If the contact detection is performed by this, the influence of noise light can be sufficiently eliminated. However, it is not preferable that display quality is deteriorated by displaying a monochrome image.

  On the other hand, the approach area is a detection unit area where the shadow of the finger approaching the screen is dropped at a position close to the screen, so the image displayed in the pixel area corresponding to the approach area is a blind spot. There is a high possibility of entering. That is, even if a black and white image is displayed in the pixel area corresponding to the approach area, the possibility that this image is visually recognized is low. In addition, it is considered that the finger approaches the screen along the normal direction of the screen. In view of this, the present embodiment adopts a policy of increasing the accuracy of contact detection by displaying a black and white image in the pixel area corresponding to the approaching area. Next, the flow of display control processing and detection processing based on these concepts will be described.

[Flow of display control processing and detection processing]
FIG. 7 is a flowchart showing the flow of the display control process. In the display control process, if the value of the approach flag is not “true” (S11: NO), the display detection control circuit 50 generates output image data Dout based on the input image data Din (S12), and this output image. Using the data Dout, electric energy applied to the m × n pixel circuits P1 is controlled so that an image represented by the output image data Dout is displayed on the screen (S13).

  The approach flag indicates whether or not an approach area exists, and is held in the memory of the control circuit 300. The value of the approach flag is “true” when an approach region exists, and “false” in other cases. Note that the initial value of the approach flag is “false”. Therefore, the image displayed on the screen immediately after the electro-optical device 1 starts operating is an image represented by the input image data Din.

  FIG. 8 is a flowchart showing the flow of the detection process. In the detection process, the display detection control circuit 50 first reads and stores m × n detection signals from the light detection circuit O1 for one screen (S21), and then the value of the approach flag must be “true”. If the approach area is detected (S23: NO), the approach flag value is set to “false” (S25).

  In the approach area detection in step S23, the display detection control circuit 50 first compares the level of each detection signal read in the current detection process with the first threshold value, and detects the detection unit area having a sufficiently large total incident light amount. Try to identify. Hereinafter, this trial is referred to as a “first trial”. The first threshold is a value corresponding to the proximity range and is determined in advance. The result of the comparison in the first trial is shown in FIG. In this figure, the photodetection circuit O1 corresponding to the detection unit region where the total incident light quantity is sufficiently large is represented by “1”, and the other photodetection circuits O1 are represented by “0”. If no detection unit area is specified in the first trial, the approach area is not detected.

  When the detection unit region is specified in the first trial, the display detection control circuit 50 determines the level of the detection signal compared with the first threshold value in the previous detection process and the current detection for each specified detection unit region. A detection unit in which the difference between the level of the detection signal compared with the first threshold value in the processing is compared with a predetermined second threshold value and the total incident light amount is sufficiently large and the rate of increase in the total incident light amount is sufficiently large Try to identify the region. Hereinafter, this trial is referred to as a “second trial”. The result of this comparison is shown in FIG. In this figure, the photodetection circuit O1 corresponding to the detection unit region where the total incident light amount is sufficiently large and the increase rate of the total incident light amount is sufficiently large is represented by “1”, and the other photodetection circuits O1 are represented by “0”. Has been. If no detection unit area is specified in the second trial, the approach area is not detected.

  The first threshold value and the second threshold value are detection unit areas in which the total incident light amount is sufficiently large and the increase rate of the total incident light amount is sufficiently large, and the distance from the screen is within the proximity range and the screen is approaching the screen. The detection unit area that covers the whole area behind the finger of the finger is specified, while the detection unit area that is part of the shadow behind the finger that is close to the screen and within the proximity of the screen is not specified It has been established. This is to reduce the possibility that a black and white image displayed in the proximity area is visually recognized.

  When the detection unit area is specified in the second trial, the display detection control circuit 50 compares the number of the specified detection unit areas with the predetermined third threshold value and the fourth threshold value to determine the total incidence. It is determined whether or not the number of detection unit regions having a sufficiently large amount of light and a sufficiently large increase rate of the total incident light amount is within a predetermined region number range. The third threshold value is a lower limit value of the area number range, and the fourth threshold value is an upper limit value of the area number range. If this determination result is negative, the approach region is not detected. If the determination result is affirmative, these detection unit areas are detected as approach areas.

  As apparent from FIG. 8, in the detection process, the value of the approach flag does not change from “false” to “true” unless an approach region is detected. Accordingly, an image represented by the input image data Din is displayed on the screen immediately after the electro-optical device 1 starts operating until the approaching area is detected. An example of the display at this time is shown in FIG. In this display example, an OK button image B1, a cancel button image B2, and an image B3 surrounding both images are displayed on the screen S.

  Eventually, when the finger approaches the screen within the proximity range and the proximity region is detected in the detection process (S24: YES), the display detection control circuit 50 sets the value of the proximity flag to “true” (S26). . As a result, the display detection control circuit 50 determines that the value of the approach flag is “true” in the display control process (S11: YES), so that the output image data is based on the input image data Din, the approach region, and the monochrome image data. Dout is generated (S14), and an image is displayed on the screen using the output image data Dout (S13).

  An example of the display at this time is shown in FIG. In this display example, the finger F approaches the screen S within the proximity range when the image of FIG. 11 is displayed. However, the portion hidden by the finger F is drawn by a perspective method. As shown in this figure, the screen S has a predetermined black and white image (specifically, a black and white checkerboard pattern image) in a pixel region corresponding to the approach region among the m × n pixel regions. In the remaining pixel area, an image (hereinafter referred to as a residual image) obtained by removing portions corresponding to these approach areas from the image represented by the input image data Din (see FIG. 11) is displayed. Is done. In the example of FIG. 12, the residual image includes an image B1, a part of the image B2, and a partial image B3.

  In the next detection process after the detection process in which the approach area is detected, the value of the approach flag is “true” (S22: YES), so the display detection control circuit 50 is for one screen read in step S21. Contact detection is performed by image processing using the detection signal (S27). More specifically, the display detection control circuit 50 performs contact detection by searching for a sufficiently clear checkerboard pattern from an image represented by the detection signal for one screen.

  The detection signal used for image processing in this contact detection includes a signal corresponding to the approach area where the total incident light quantity ≈ incident reflected light quantity, and the color of the pixel area corresponding to the approach area is white (maximum luminance) or Since it is black (minimum luminance), the level difference between a plurality of detection signals corresponding to the approaching region becomes large. Accordingly, the checkerboard detection accuracy in this image processing is higher than that in the case of displaying checkered images of other colors.

  If contact is not detected by contact detection (S28: NO), approach area detection is performed (S23). After that, if the finger keeps approaching without touching the screen, the approaching area is continuously detected, so the value of the approaching flag continues to be “true”, and the pixel corresponding to the approaching area detected immediately before is displayed on the screen. A black and white image is displayed in the area, and a residual image is displayed in the remaining pixel area. When the finger no longer approaches the screen and the approach region is no longer detected (S24: NO), the value of the approach flag changes from “true” to “false” (S25), and the screen displays the input image data Din. The image to be displayed is displayed (S11: NO, S12, S13).

  Conversely, when the finger touches the screen and this contact is detected (S28: YES), the display detection control circuit 50 performs a contact process. In the contact process, the display detection control circuit 50 supplies a signal indicating the contact position to a higher-level device (for example, CPU). Thereafter, until the contact is not detected, the approach area detection is not performed, and the value of the approach flag continues to be “true”. Then, when the finger leaves the screen, no contact is detected (S28: NO), and the approach area detection is performed (S23). Since the approach area is not detected in this approach area detection (S24: NO), the value of the approach flag changes from “true” to “false” (S25), and an image represented by the input image data Din is displayed on the screen. (S11: NO, S12, S13).

<2. Second Embodiment>
FIG. 1 is also a block diagram showing a configuration of an electro-optical device 2 according to a second embodiment of the present invention. In the electro-optical device 1, a black and white checkered pattern image is displayed in the approach region, but in the electro-optical device 2, a white image that is entirely white and a black image that is all black are alternately displayed in the approach region. . This difference is realized by including a control circuit 700 in place of the control circuit 300. FIG. 2 is also a conceptual diagram showing a functional configuration of the display detection control circuit 60. The display detection control circuit 60 differs from the display detection control circuit 50 in that the display control unit 61 and the detection control unit realized by the control circuit 700 are not the display control unit 51 and the detection control unit 52 realized by the control circuit 300. 62 points.

  The display control process and the detection process performed by the display detection control circuit 60 are the same as the display control process and the detection process performed by the display detection control circuit 50. However, the black and white image data used by the display detection control circuit 60 to generate the output image data in step S14 is not data representing a black and white checkerboard pattern, but data representing a white image (hereinafter referred to as “white image data”). ) And data representing a black image (hereinafter referred to as “black image data”). Further, due to this difference, the contents of the contact detection in step S27 are also different.

  Whether white image data or black image data is used in step S14 is periodically switched. FIG. 13 is a flowchart showing the flow of switching processing performed by the display detection control circuit 60. As shown in this figure, the display detection control circuit 60 switches the black and white image data used in step S14 between the white image data and the black image data at every repetition period of the detection process (S31, S32). Note that the present embodiment may be modified so that the above switching is performed only while the value of the proximity flag is “true”.

  According to the present embodiment, when the proximity region is detected (S24: YES) and the value of the proximity flag becomes “true” (S26), the display detection control circuit 50 has the value of the proximity flag “true”. (S11: YES), output image data Dout is generated based on the input image data Din, the approaching area, and the monochrome image data (S14), and an image is displayed on the screen using the output image data Dout (S13). . An example of the display at this time is shown in FIG. In this display example, the finger F approaches the screen S within the proximity range when the image of FIG. 11 is displayed. The display shown in this figure is different from the display shown in FIG. 12 only in that a black image is displayed instead of a black and white checkered pattern image.

  Hereinafter, it is assumed that the finger keeps approaching without touching the screen. In this case, in the next detection process after the detection process in which the approaching area is detected for the first time, the memory has one screen portion when the black image is displayed as the detection signal when the black and white image is displayed. Therefore, the display detection control circuit 50 skips the contact detection in step S27. Therefore, no contact is detected in this detection process.

  In the next detection process, the black and white image data is switched from the black image data to the white image data by the switching process, and the white image is displayed in the pixel area corresponding to the approaching area by the display control process (see FIG. 15), in the memory, as a detection signal when a black and white image is displayed, a detection signal for one screen read previously (detection signal when a black image is displayed) and one screen read this time Minute detection signals (detection signals when a white image is displayed) are accumulated, the display detection control circuit 50 detects in order to eliminate the influence of noise light (environment light) in step S27. For each unit region, the difference between the level of the detection signal read last time and the level of the detection signal read this time is calculated and stored in the memory. No contact is detected in this detection process.

  In the next detection process, the black and white image data is switched from the white image data to the black image data by the switching process, and the black image is displayed in the pixel area corresponding to the approaching area by the display control process (see FIG. 14), in the memory, as a detection signal when a monochrome image is displayed, the detection signal for one screen read previously (detection signal when a white image is displayed) and one screen read this time Minute detection signal (detection signal when a black image is displayed) is accumulated, and the difference calculated for one screen calculated last time is accumulated. In order to eliminate the influence of noise light (environmental light), the difference between the level of the detection signal read last time and the level of the detection signal read this time is calculated for each detection unit area. Accumulate in re, by performing the same process as proximity area detecting step S23, a contact detection performed by using the difference of the accumulated double screens. However, the threshold value used in this contact detection is determined more strictly than the threshold value used in the approach region detection.

<3. Modification>
The present invention may include various forms obtained by modifying or applying each of the above-described embodiments within the scope thereof. Such a form is illustrated below.
Each embodiment may be modified such that an area that falls behind the finger whose distance from the screen is within the proximity range is detected as the proximity area, and a monochrome image is displayed in the proximity area instead of the proximity area. In this form, even when the finger moves away from the screen, a monochrome image is displayed if the distance between the finger and the screen is within the proximity range.

  Each embodiment is modified so that the first threshold value and the second threshold value are detected unit areas in which the total incident light amount is sufficiently large and the increase rate of the total incident light amount is sufficiently large. In addition to the detection unit area where the whole area falls behind the finger approaching the screen, the detection unit area where the distance from the screen is within the proximity range and a part of the shadow behind the finger approaching the screen is specified. You may decide to be.

  In each embodiment, the pixel region (pixel circuit P1) and the detection unit region (detection circuit O1) have a one-to-one correspondence. However, the pixel region (pixel circuit P1) and the detection unit region ( The detection circuit O1) may correspond to a plurality of one-to-one correspondences. For example, 2 (rows) × 2 (columns) = one detection unit region (photodetection circuit O1) may be provided for every four pixel regions (pixel circuit P1). A display example of this form is shown in FIG. Furthermore, this form is modified, and the first threshold value and the second threshold value are set as a detection unit region in which the total incident light amount is sufficiently large and the increase rate of the total incident light amount is sufficiently large, and the distance from the screen is within the proximity range. In addition to the detection unit area where the whole area falls behind the finger approaching the screen, the detection unit area where the distance from the screen is within the proximity range and a part of the shadow behind the finger approaching the screen is specified. You may decide to be. A display example of this form is shown in FIG. These forms have the advantages that they are easy to implement and can further improve the accuracy of contact detection.

  The first embodiment may be modified such that a monochrome image having a special pattern different from the monochrome checkerboard pattern is displayed in the approach area. Such special patterns include white and black stripes. In addition, each embodiment may be modified to determine the intensity of ambient light by any known method, and the contents and threshold values of approaching area detection and contact detection may be switched according to the result. In addition, each embodiment may be modified so that the arrangement pattern of the pixel circuit P1 and the photodetection circuit O1 is an arrangement pattern other than a matrix. In addition, each embodiment may be modified so that an arbitrary electro-optical element such as a light valve element other than a liquid crystal element or a light emitting element such as an OLED is used. In addition, each embodiment may be modified to use a photosensor other than a photodiode, such as a photoresistor. Further, each embodiment may be modified to be a device that inputs a touch with an arbitrary object other than a finger (for example, a pen).

Each embodiment may be applied to various electronic devices.
FIG. 18 shows a configuration of a mobile personal computer to which the electro-optical device 1 or 2 is applied. The personal computer 2000 includes the electro-optical device 1 as a display unit and a touch input unit, and a main body 2010. Further, the main body 2010 is provided with a power switch 2001 and a keyboard 2002.
FIG. 19 shows a configuration of a mobile phone to which the electro-optical device 1 or 2 is applied. The cellular phone 3000 includes the electro-optical device 1 as a display unit and a touch input unit, a plurality of operation buttons 3001, and a scroll button 3002. By operating the scroll button 3002, the screen displayed on the electro-optical device 1 is scrolled.
FIG. 20 shows the configuration of a personal digital assistant (PDA) to which the electro-optical device 1 or 2 is applied. The portable information terminal 4000 includes the electro-optical device 1 as a display unit and a touch input unit, a plurality of operation buttons 4001, and a power switch 4002. When the operation button 4001 is operated, various types of information such as an address book and a schedule book are displayed on the electro-optical device 1.
Electronic devices to which the electro-optical device 1 is applied include a digital still camera, a car navigation device, an electronic notebook, a word processor, a workstation, a video phone, a POS terminal, an ATM (Automated) in addition to those shown in FIGS. Teller Machine: automatic teller machine) and vending machines. The electro-optical device 1 or 2 described above can be applied as a display unit and a touch input unit of these various electronic devices.

2 is a block diagram showing a configuration of an electro-optical device 1 or 2 according to the first or second embodiment of the present invention. FIG. 3 is a conceptual diagram showing a functional configuration of a display detection control circuit 50 or 60 of the electro-optical device 1 or 2. FIG. 3 is a circuit diagram illustrating a configuration of a light detection circuit O1 of the electro-optical device 1 or 2. FIG. 6 is a timing chart showing waveforms of sensor scanning signals W1 to Wm and a sampling signal SHG in the electro-optical device 1 or 2; It is a figure which shows the state of the photon detection circuit O1. It is a figure which shows the state of the photon detection circuit O1. It is a flowchart which shows the flow of the display control process which the display detection control circuit 50 or 60 performs. It is a flowchart which shows the flow of the detection process which the display detection control circuit 50 or 60 performs. It is a conceptual diagram for demonstrating the content of the approach area | region detection in a detection process. It is a conceptual diagram for demonstrating the content of the approach area | region detection in a detection process. 6 is a diagram illustrating an example of a display of the electro-optical device 1. FIG. 6 is a diagram illustrating another example of display of the electro-optical device 1. FIG. 4 is a flowchart showing a flow of switching processing performed by a display detection control circuit 60. 6 is a diagram illustrating an example of a display on the electro-optical device 2. FIG. 10 is a diagram illustrating another example of display of the electro-optical device 2. FIG. It is a figure which shows an example of the display which concerns on one modification of this invention. It is a figure which shows an example of the display which concerns on the other modification of this invention. It is a perspective view which shows an example of the electronic device which concerns on this invention. It is a perspective view which shows another example of the electronic device which concerns on this invention. It is a perspective view which shows another example of the electronic device which concerns on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 2 ... Electro-optical device, 100 ... Scanning line drive circuit, 200 ... Data line drive circuit, 300 ... Control circuit, 400 ... Image processing circuit, 500 ... Scanning circuit for sensors, 600 ... Detection signal reading circuit, 50, 60 Display detection control circuit, 11 Photodiode (photosensor), P1 Pixel circuit, O1 Photodetection circuit, 2000 Personal computer, 3000 Mobile phone, 4000 Mobile information terminal

Claims (8)

Arranged in a unit circuit region extending along a planar screen having a plurality of pixel regions and a plurality of detection unit regions corresponding to the plurality of pixel regions in a certain number of one-to-one, one-to-one with the plurality of pixel regions And a plurality of pixel circuits each including an electro-optic element whose light emission characteristics or light transmission characteristics are changed by given electric energy, and that emits light from the electro-optic element from the corresponding pixel region; ,
A plurality of detection unit regions arranged in the unit circuit region, corresponding to the plurality of detection unit regions on a one-to-one basis, each of which includes a photosensor and generates a detection signal having a level corresponding to light incident on the detection unit region. A light detection circuit;
The display control process for controlling the electrical energy applied to the plurality of pixel circuits to display an image on the screen is repeatedly performed, the detection signals are read from the plurality of light detection circuits, and the levels of the read detection signals are Based on a threshold value, display detection is performed by repeatedly performing a detection process for detecting, as a proximity area, an object behind a target whose distance from the screen is within a predetermined distance range among the plurality of unit detection areas. A control circuit,
The display detection control circuit includes:
In the display control process, when the proximity area is not detected, an image represented by the given image data is displayed on the screen, and when the proximity area is detected, the plurality of proximity areas are detected. Of the pixel area, a black and white image is displayed in the pixel area corresponding to the adjacent area, and an image obtained by removing a part corresponding to the adjacent area from the image represented by the image data is displayed in the remaining pixel area. So that the control is performed,
In the detection process, when the proximity region has been detected in the previous detection process, based on the level of the detection signal read from the plurality of light detection circuits, the object and the screen Detect contact,
An electro-optical device. Among the objects within the distance range, the object is only the one that is approaching the screen.
The electro-optical device according to claim 1. The black and white image is an image having a white area and a black area.
The electro-optical device according to claim 1 or 2. The black and white image is a white image where the entire area is white or a black image where the entire area is black,
The display detection control circuit performs a process of switching the black and white image between the white image and the black image after the proximity area is detected until the proximity area is no longer detected. To continue the switching process
The electro-optical device according to claim 1 or 2. The proximity region includes, among the plurality of unit detection regions, the entire region that enters the shade, does not include the portion that does not enter the shade,
The electro-optical device according to claim 1, wherein The certain number is plural.
The electro-optical device according to claim 1, wherein   An electronic apparatus comprising the electro-optical device according to claim 1. Arranged in a unit circuit region extending along a planar screen having a plurality of pixel regions and a plurality of detection unit regions corresponding to the plurality of pixel regions in a certain number of one-to-one, one-to-one with the plurality of pixel regions And a plurality of pixel circuits each including an electro-optic element whose light emission characteristics or light transmission characteristics are changed by given electric energy, and that emits light from the electro-optic element from the corresponding pixel region; A plurality of detection circuit units that are arranged in the unit circuit region and have a one-to-one correspondence with the plurality of detection unit regions, each of which includes a photosensor and generates a detection signal having a level corresponding to light incident on the detection unit region. A method for controlling an electro-optical device comprising:
The display control process for controlling the electrical energy applied to the plurality of pixel circuits to display an image on the screen is repeatedly performed, the detection signals are read from the plurality of light detection circuits, and the levels of the read detection signals are Based on a threshold value, among the plurality of unit detection areas, a detection process is repeatedly performed to detect, as a proximity area, an object that falls behind a target whose distance from the screen is within a predetermined distance range,
In the display control process, when the proximity area is not detected, an image represented by the given image data is displayed on the screen, and when the proximity area is detected, the plurality of proximity areas are detected. Of the pixel area, a black and white image is displayed in the pixel area corresponding to the adjacent area, and an image obtained by removing a part corresponding to the adjacent area from the image represented by the image data is displayed in the remaining pixel area. So that the control is performed,
In the detection process, when the proximity region has been detected in the previous detection process, based on the level of the detection signal read from the plurality of light detection circuits, the object and the screen Detect contact,
A control method for an electro-optical device.

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