JP4605243B2 - Image display device and driving method of image display device - Google Patents

Description

  The present invention relates to an image display device having a function of detecting the position of an object and the like, and a method for driving the image display device.

  2. Description of the Related Art Conventionally, a technique for detecting the position of an object that touches or approaches a display device is known. Among them, a representative and widely used technique is a display device provided with a touch panel.

  There are various types of touch panels, but a type that detects a capacitance is one of the most popular touch panels. This type captures changes in the surface charge of the panel by touching the touch panel with a finger, thereby detecting the position of the object. Thereby, the user can operate intuitively.

  In recent years, various technologies have been proposed that enable an intuitive operation by detecting the position of an object on a display device without providing these touch panels.

For example, Patent Document 1 discloses an infrared type in which a light emitting element such as infrared light and a light receiving element are arranged at one end of a flat pad on which a finger can move, and pointer control can be performed only by moving the finger. A finger input pointer device is disclosed.
Japanese Patent Laid-Open No. 11-149348

  However, this technology must include an input device separately from the display device, which increases the cost of the product due to an increase in the number of parts, and is intuitively operated compared to a display device having a touch panel. There was a problem that it was not possible.

  In addition, for a display device provided with a touch panel, the number of components increases by providing the touch panel on the display screen, and the cost of the product increases. In addition, there is a problem that the light from the display screen changes when the light passes through the touch panel, causing deterioration in image quality.

  Further, in the case of the touch panel of the above-described type that detects electrostatic capacitance, only one point position on the display screen can be detected at the same time, and it is always convenient for the user. There was a problem that I could not say.

  In other words, these conventional techniques have a problem that it is difficult to detect the position of an object without degrading the image quality with a simple structure while ensuring convenience.

  The present invention has been made in view of such problems, and an object of the present invention is to provide an image display device that can detect the position of an object and the like with a simple structure without degrading image quality while ensuring convenience. An object of the present invention is to provide a method for driving an image display device.

The image display device of the present invention includes a plurality of light emitting / receiving elements each having both a light emitting function and a light receiving function, light emission driving means for driving the light emitting / receiving elements to emit light based on the image data, and light emission based on the image data. Light receiving drive means for receiving and driving other light emitting and receiving elements so that the light emitted from one light emitting and receiving element reflected by the object to be detected is received by the other light emitting and receiving elements; A comparator that performs A / D conversion by comparing the obtained light reception signal with a predetermined threshold value, and a value that increases as the light emission amount increases and the light emission amount decreases according to the content of the image being displayed. as value according to become smaller, be detected with a threshold value generator for changing the threshold value in the comparator, the detection target object based on a light reception signal after a / D conversion is made by the comparator In which and detection means. Further, the light emission drive means and the light reception drive means drive each light emitting / receiving element so that the other one light emitting / receiving element performs the light receiving operation corresponding to the light emitting operation of the plurality of light emitting / receiving elements. ing.

According to the driving method of the image display apparatus of the present invention, a plurality of light emitting / receiving elements each having both a light emitting function and a light receiving function are arranged, the light emitting / receiving element is driven to emit light based on image data, and light is emitted based on the image data. The other light emitting / receiving elements are driven to receive light received from the other light emitting / receiving elements so that the light emitted from one light emitting / receiving element reflected by the object to be detected is received by the other light emitting / receiving elements. A / D conversion is performed by comparing the signal with a predetermined threshold value, and the value increases as the light emission amount increases and decreases as the light emission amount decreases according to the content of the image being displayed. The threshold value is changed so that the detection target object is detected based on the received light signal after the A / D conversion . Further, each light emitting / receiving element is driven so that the other one light emitting / receiving element performs the light receiving operation in response to the light emitting operation of the plurality of light emitting / receiving elements.

In the image display device and the driving method of the image display device of the present invention, the light emitting / receiving element emits light based on the image data. Another light emitting / receiving element receives the light emitted from the light emitting / receiving element and reflected by the object to be detected, and outputs a light receiving signal. A light reception signal obtained from another light emitting / receiving element is compared with a predetermined threshold value, and A / D conversion is performed. At this time, according to the content of the image being displayed, the threshold value is changed so that the value increases as the light emission amount increases and the value decreases as the light emission amount decreases. Then, the detection target object is detected based on the light reception signal after the A / D conversion . Further, by driving each light emitting / receiving element so that the other one light emitting / receiving element performs the light receiving operation corresponding to the light emitting operation of the plurality of light emitting / receiving elements, the data amount of the light receiving signal is reduced.
Note that, even when a plurality of detection target objects are arranged at the same time, the plurality of detection target objects can be detected based on the light reception signal. Here, “disposed at the same time” means, for example, a situation where a plurality of fingers are in contact with or in close proximity to each other on the display unit of the image display device.

  In addition, when a threshold value is set according to the property of the object to be detected or the purpose or accuracy of the detection, the received light signal is compared with the set threshold value to The detection target object is detected in a manner corresponding to the above. Here, “the property of the detection target object” means, for example, the size and surface state (reflectance, color, roughness, etc.) of the object, and “the purpose of detection” means, for example, the object The detection of the position, the detection of the size of the object, the detection of the color of the object, etc. mean the detection accuracy, and the “detection accuracy” means the detection resolution.

Also, the ambient light intensity present in the surroundings is obtained based on the light reception signal obtained when black display is performed in a state where the detection target object is not close to the light emitting / receiving element, and only the amount of the ambient light intensity is obtained. When the detection target object is detected based on the received light signal after A / D conversion is performed using the added threshold value , the detection target object is detected regardless of the influence of the ambient light. Is done. Here, “black display” means a display in a state where all the light emitting and receiving elements included in the image display device emit light at the lowest luminance, and “environment light” means, for example, sunlight or light from an indoor lamp. , Means the light radiated from the surroundings.

  Further, a part of the input image data is replaced with mark data for displaying a predetermined mark, and the image data is synthesized, and light emitted from the light emitting / receiving element according to the mark data is positioned corresponding to the light emitting / receiving element. When light is received by another light emitting / receiving element, it is detected whether the detection target object has approached this mark being displayed. In this case, it is possible to move the mark during image display, and it is also possible to configure the mark to move in accordance with the movement of the pattern, for example. Here, “input image data” means raw image data before being combined as input to the image display device, and “mark data” means, for example, the shape, brightness, and shape of an arbitrary figure or character. A sign represented by color or the like.

  Here, for example, the plurality of light emitting / receiving elements are arranged in a matrix, and the light emitting / receiving elements are driven so as to perform light emission operation in a line-sequential manner. May be configured to be driven so as to perform a light receiving operation in a line sequential manner. Here, “matrix shape” means a state in which a plurality of light emitting and receiving elements are arranged in a matrix in the horizontal line direction and the vertical line direction of the screen over the entire display unit of the image display device. An element is called a pixel. “Line-sequential light-emitting operation” and “line-sequential light-receiving operation” are operations in which light-emitting and light-receiving elements included in each pixel for one horizontal line sequentially perform light-emitting operation and light-receiving operation for each horizontal line. This means that by performing this operation over the entire display section of the image display device, it is possible to display image data for one screen and receive light for each pixel for one screen.

According to the image display device and the driving method of the image display device of the present invention, each includes a plurality of light emitting and receiving elements having both a light emitting function and a light receiving function, and the light emitting and receiving elements are driven to emit light based on the image data. The other light emitting / receiving elements are driven so that the light emitted from the light emitting / receiving element and reflected by the detection target object are received by the other light emitting / receiving elements . A / D conversion is performed in comparison with the threshold value, and the value increases as the light emission amount increases and decreases as the light emission amount decreases according to the content of the image being displayed. Since the detection target object is detected based on the light reception signal after the threshold value is changed and A / D converted , the position of the object can be secured without degrading the image quality with a simple structure while ensuring convenience. Etc. It can be out.
Further, since each light emitting / receiving element is driven so that the other one light emitting / receiving element performs the light receiving operation in response to the light emitting operation of the plurality of light emitting / receiving elements, the data amount of the light receiving signal can be reduced. Thus, the configuration on the light receiving side can be simplified and the power consumption can be reduced.

  Hereinafter, the best mode for carrying out the present invention (hereinafter simply referred to as an embodiment) will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 shows the overall configuration of an image display apparatus according to the first embodiment of the present invention.

  The image display apparatus according to the present embodiment includes a display unit 1, a display signal generation unit 21, a display signal holding control unit 22, a display signal driver 23, a light emission side scanner 24, a light reception signal selection scanner 31, and light reception. A signal receiver 32, a light reception signal holding unit 33, and a position detection unit 34 are provided.

  The display unit 1 includes, for example, an organic or inorganic EL (ElectroLuminescence) display or LCD (Liquid Crystal Display) in which a plurality of pixels 11 are arranged in a matrix over the entire surface, and operates in a line sequential manner as will be described later. While displaying, images such as predetermined figures and characters are displayed. Each pixel 11 is composed of a light emitting / receiving cell CWR including one light emitting / receiving element, and each pixel has both a light emitting operation function and a light receiving operation function as described later.

  The display signal generation unit 21 generates a display signal for display, for example, for each screen (for each display of one field) based on the supplied data generated by a CPU (Central Processing Unit) (not shown). , And outputs it to the display signal holding control unit 22.

  The display signal holding control unit 22 stores the display signal output from the display signal generation unit 21 for each screen (for each display of one field), for example, in a field memory including an SRAM (Static Random Access Memory). And the light emitting side scanner 24 and the display signal driver 23 that drive each light emitting / receiving cell CWR to emit light, and the light receiving signal selection scanner 31 that drives each light emitting / receiving cell CWR to receive light. Have Specifically, the light emission side scanner 24 has a light emission timing control signal 41, the light reception signal selection scanner 31 has a light reception timing control signal 42, the display signal driver 23 has a control signal and a display signal held in the field memory. Based on the above, a display signal for one horizontal line is output. With these control signals and display signals, a line sequential operation is performed as will be described later.

  The light emitting side scanner 24 has a function of selecting the light emitting / receiving cell CWR to be driven for light emission according to the light emission timing control signal 41 output from the display signal holding control unit 22. Specifically, as will be described later, a selection signal is supplied via a light emission gate line connected to each pixel 11 of the display unit 1 to control the first switch. That is, when a voltage that turns on the first switch of a certain pixel is applied by the selection signal, the pixel emits light with a luminance corresponding to the voltage supplied from the display signal driver 23. Yes.

  The display signal driver 23 has a function of supplying display data to the light emitting / receiving cell CWR to be driven for light emission according to the display signal for one horizontal line output from the display signal holding control unit 22. Specifically, as described later, a voltage corresponding to the display data is supplied to the pixel 11 selected by the light emitting side scanner 24 via the data supply line connected to each pixel 11 of the display unit 1. The light-emitting side scanner 24 and the display signal driver 23 operate in a line-sequential manner, whereby an image corresponding to arbitrary display data is displayed on the display unit 1.

  The light reception signal selection scanner 31 switches between the light emission drive and the light reception drive of the light emission light reception cell CWR in accordance with the light reception timing control signal 42 output from the display signal holding control unit 22, thereby changing the light emission light reception cell CWR to be the light reception drive target. Has a function to select. Specifically, as will be described later, a switching signal is supplied via a switching line connected to each pixel 11 of the display unit 1 to control the second switch and the third switch. That is, a voltage that turns off a second switch selected during light emission driving in a pixel by a switching signal is applied, and a voltage that turns on a third switch selected during light reception driving is applied from the pixel. The detected light reception signal is output to the light reception signal receiver 32. Accordingly, for example, light reflected from an object that comes in contact with or close to the light based on light emitted from a certain light emitting / receiving cell CWR can be received and detected by another light emitting / receiving cell CWR. The light reception signal selection scanner 31 outputs a light reception block control signal 43 to the light reception signal receiver 32 and the light reception signal holding unit 33, and has a function of controlling the blocks contributing to the light reception operation.

  The light receiving signal receiver 32 has a function of acquiring a light receiving signal for one horizontal line output from each light emitting light receiving cell CWR in accordance with the light receiving block control signal 43 output from the light receiving signal selection scanner 31. The light reception signal for one horizontal line acquired by the light reception signal receiver 32 is output to the light reception signal holding unit 33.

  The light reception signal holding unit 33 converts the light reception signal output from the light reception signal receiver 32 into a light reception signal for each screen (each field display) in accordance with the light reception block control signal 43 output from the light reception signal selection scanner 31. It has a function of reconfiguring and storing and holding it in a field memory composed of, for example, an SRAM. The received light signal data stored in the received light signal holding unit 33 is output to the position detecting unit 34. The received light signal holding unit 33 may be formed of a storage element other than a memory. For example, the received light signal data may be held as analog data. Hereinafter, in this embodiment, unless otherwise specified, it is assumed that the received light signal is held as analog data.

  The position detection unit 34 has a function of performing signal processing based on data of a light reception signal output from the light reception signal holding unit 33 and specifying a position where an object detected in the light emitting / receiving cell CWR is present. This makes it possible to specify the position of an object that is in contact with or close to it. When the light reception signal holding unit 33 stores the light reception signal data as analog data as described above, the position detection unit 34 performs analog / digital conversion (hereinafter referred to as A / D conversion). Signal processing is performed.

FIG. 2 shows an example of the configuration of the display unit 1 in FIG. It is assumed that the display unit 1 has a configuration in which a total of (m × n) pixels 11 are arranged in a matrix, with m in the horizontal line direction and n in the vertical line direction. Here, for example, XGA (eXtended Graphics) which is a general display standard in a PC (Personal Computer) or the like.
In the case of a display unit of the (Array) standard, a total of 2359296 pixels of m = 1024 × 3 (RGB) and n = 768 are arranged in a matrix.

  As shown in FIG. 2, the display unit 1 includes a total of (m × n) pixels 11, the light emitting / receiving cells CWR 11 to CWRmn included in each pixel, and the number of the pixels 11. The m data supply lines DW (DW1 to DWm) and the data read lines DR (DR1 to DRm), and the n light emission gate lines G (G1 to Gn) and the switching lines S (S1 to Sn) are connected. With.

  The data supply line DW, the data read line DR, the light emission gate line G, and the switching line S are connected to the display signal driver 23, the light reception signal receiver 32, the light emission side scanner 24, and the light reception signal selection scanner 31, respectively. A selection signal and a switching signal are supplied to each light emitting / receiving cell CWR, and a light receiving signal is output from each light emitting / receiving cell CWR. Further, as shown in FIG. 2, one data supply line DW, data read line DR, light emission gate line G, and switching line S are connected to each light emitting / receiving cell CWR. Further, for example, one light supply / receiver cell CWR11, CWR12,..., CWR1n is connected to one data supply line DW1 and one data read line DR1 in common, for example, one horizontal line of light emitting / receiving cell CWR11, One light emitting gate line G and one switching line S are commonly connected to CWR21,..., CWRm1. Note that an arrow X in FIG. 2 indicates the scanning direction of the light emission gate line G and the switching line S as described later.

  FIG. 3 schematically shows an example of the arrangement configuration of the light-emitting / receiving cells CWR in the display unit 1 of FIG. 1 in a cross-sectional view. In the example of FIG. 3, the light emitting / receiving element included in the light emitting / receiving cell CWR is an organic EL element, and an organic EL layer is provided between a pair of transparent substrates. In this figure, i, which is a code representing a position, represents a natural number. As described above, for example, in the case of an XGA standard display unit (m = 1024 × 3 (RGB), n = 768), for example, the center of the display unit I = 1536 when the vertical line is.

  Further, the cross-sectional view shown in FIG. 3 corresponds to the vertical cross-section taken along the line AA in the display unit 1 shown in FIG. The display unit 1 is disposed between a pair of transparent substrates 12A and 12B and the transparent substrates 12A and 12B, and has a plurality of light emitting / receiving cells CWR (CWR21) having a structure separated from each other by the partition wall 13 as described above. , CWR22, CWR23, CWR24, CWR25,. As described above, the light emitting / receiving cell CWR includes an organic EL element as the light emitting / receiving element. Further, in this drawing, the emitted light LW by the light emitting / receiving element included in each light emitting / receiving cell CWR is also shown. The other layers in the general organic EL display unit are not shown and are omitted. The same applies to FIG.

  In addition, the sectional view of the arrangement configuration example of the light emitting and receiving cells CWR in the display unit 1 according to the present embodiment is not limited to these, and other arrangement configurations may be used. In the example of the cross-sectional view shown in FIG. 3, the example in which the light emitting / receiving element EL is composed of an organic EL element has been described. However, if the light emitting / receiving element is an element having a light emitting function and a light receiving function, For example, an LED element or the like may be used.

  FIG. 4 shows a circuit configuration of the light emitting / receiving cell CWR in FIG.

  The light emitting / receiving cell CWR includes one light emitting / receiving element EL, and the light emitting gate line G, the data supply line DW, the switching line S, and the data readout line DR are connected to the light emitting / receiving cell CWR. . In other words, the gate line and the data line are increased by one for receiving light as compared with a cell for one pixel including a normal light emitting element. The light emitting / receiving cell CWR includes one light emitting / receiving element EL, a capacitor C, a resistor R, a data supply line DW and one end of the capacitor C according to a selection signal supplied from the light emitting gate line G. A first switch SW1 that selectively conducts between the second switch and a second switch that selectively conducts between the other end of the capacitor and one end of the light emitting / receiving element EL in accordance with a switching signal supplied from the switching line S. Similarly, the switch SW2 has a third switch SW3 that selectively conducts between one end of the light emitting / receiving element EL and the data read line DR in response to a switching signal supplied from the switching line S. The other end of the element EL is grounded. One end of the resistor R is connected to the data read line DR, and the other end of the resistor R is connected to the ground or a negative bias point (not shown).

  Here, the operation of each component during the light emitting operation and the light receiving operation will be specifically described. First, the light emitting operation and the light receiving operation are performed using the following characteristics of the light emitting / receiving element EL. In other words, for example, an organic EL element or an LED element configured as a light emitting / receiving element in this embodiment emits light when a forward bias voltage is applied, but receives a light and receives a current when a reverse bias voltage is applied. It has the nature to occur. Therefore, as will be described later, the light emitting / receiving element EL cannot perform the light emitting operation and the light receiving operation at the same time, and needs to be operated in a time division manner in order to perform both operations.

  Therefore, at the time of the light emission operation, the first switch SW1 and the second switch SW2 are turned on in response to the selection signal supplied from the light emission gate line G and the switching signal supplied from the switching line S as described above. The third switch SW3 is turned off, and a forward bias voltage is applied to the light emitting / receiving element EL. Here, the capacitor C is charged from the data supply line DW through the path I1 so as to emit light with a luminance corresponding to the display signal, and based on this, a current flows through the light emitting / receiving element EL through the path I2, and the light emission operation is performed. Is supposed to do.

  On the other hand, during the light receiving operation, the second switch SW2 is turned off and the third switch SW3 is turned on according to the switching signal supplied from the switching line S as described above, and the light emitting / receiving element EL is reversely directed. A bias voltage is applied, and a current corresponding to the amount of light received by the light emitting / receiving element EL is supplied to the data read line DR through a path I3 to perform a light receiving operation. When neither the light emission operation nor the light reception operation is performed, all of the first switch SW1, the second switch SW2, and the third switch SW3 are in the off state, and the data supply line DW The data readout line DR is disconnected from the light emitting / receiving element EL. The resistor R connected to the data read line DR generates a potential difference at both ends of the resistor R based on the current supplied to the data read line DR through the path I3 as described above, and this is used as a light reception signal. Has a function to output.

  Next, an operation for detecting an object in contact with or close to the image display apparatus having the above-described configuration will be described.

  First, with reference to FIG. 5, an operation of detecting an object that is in contact with or close to the image display device having the above-described configuration will be described. FIG. 5 shows an example of processing for detecting a detection target object in the image display apparatus of FIG. 3 corresponds to the example of the structure in which the light-emitting / receiving cell CWR including the organic EL element which is a light-emitting / receiving element is separated by the partition wall 13, and has the same components as those shown in FIG. Are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  As shown in FIG. 5, for example, when the detection target object 15 such as a finger is brought into contact with or close to the display unit 1, for example, the emitted light LW1 emitted from the light emitting / receiving cell CWR23 is reflected by the detection target object 15. Here, since the light emitting / receiving element EL needs to perform the light emitting operation and the light receiving operation in a time-sharing manner as described above, the light emitting / receiving element cannot emit reflected light while the light emitting / receiving element emits light. Therefore, it is possible to detect the light emitted from the light emitting / receiving elements on one horizontal line by applying a reverse bias voltage to the light emitting / receiving elements on the other horizontal lines and perform a light receiving operation. For example, the reflected light LR1 is incident on a light emitting / receiving cell in a horizontal line close to the light emitting / receiving cell CWR23, for example, CWR24 or CWR25, but the reflected light is incident on a light emitting / receiving cell in a horizontal line far from the light emitting / receiving cell CWR23. Does not enter. For this reason, a light reception signal is obtained only from the light emitting / receiving cell CWR whose position is close to a certain detection target object 15. For example, the timing is such that light emitted from the light emitting / receiving cell CWR of the horizontal line that is driven to emit light and reflected by the detection target object 15 is detected by the light emitting / receiving element of the horizontal line adjacent to the horizontal line that is emitting light. It shall be driven. While the light receiving signal is detected from the light emitting / receiving elements on the horizontal line in the vicinity of the detection target object 15, the light reception signal is not detected from other areas, so the detection target object 15 exists at any position on the display unit 1. Can be detected. By sequentially performing such light emission drive and light reception drive for each horizontal line (hereinafter referred to as line sequential drive), it becomes possible to detect the detection target object 15 while displaying an image over the entire display unit 1. .

  FIG. 6 shows an example of the line sequential light emitting operation and the line sequential light receiving operation in the image display apparatus of FIG. Here, one square shown in FIG. 6 represents the pixel 11 in the display unit 1.

  In the example of the line-sequential light emission operation shown in FIG. 6A, for example, a situation is shown in which one horizontal line at the position indicated by the arrow P2 sequentially emits light in the direction indicated by the scan direction X. Further, in this example, one horizontal line at the position indicated by the arrow P2 is constant until a certain period of time has elapsed on the screen when the display data is drawn, that is, until the next image data is supplied by the display signal driver 23. The light emission state is maintained only for a period, and the entire display unit 1 is divided into light emitting areas 51A and 51B and a non-light emitting area 52. In this case, one horizontal line at the position indicated by the arrow P2 performs a line-sequential light emission operation, so that the whole or most of the display unit 1 becomes a light-emitting region within a certain time during which the light emission state is maintained, and certain image data Can be displayed over the entire display unit 1. The period during which the light emission state is maintained is determined by, for example, the capacitance value of the capacitor C in the circuit configuration of the light emitting / receiving cell CWR shown in FIG. 4, and can be arbitrarily set. In the example shown in FIG. 6A, the non-light-emitting region 52 exists in the display unit 1, but the non-light-emitting region 52 also moves line-sequentially. Will not be a problem.

  Next, in the example of the line sequential light emitting operation and the line sequential light receiving operation shown in FIGS. 6B and 6C, for example, one horizontal line at the position indicated by the arrows P2 and P5 is sequentially applied in the direction indicated by the scanning direction X. As the light emitting operation proceeds, the light reflected from the detection target object 15 by the light emitted from the light emitting region 51A by the one horizontal line at the positions indicated by the arrows P3 and P6 is received in a line sequential manner in the direction indicated by the scanning direction X. It represents the situation of doing. As described above, one horizontal line performs a line sequential light emission operation, and one horizontal line at the adjacent position always performs a line sequential light reception operation of the reflected light from the emitted light, so that the entire display unit 1 becomes a light emitting region. In addition to displaying a certain image data over the entire display unit 1, whether or not a detection target object 15 exists in the vicinity of the display unit 1 based on a light reception signal detected from the light receiving element. In this case, the position can be detected. Even in this case, the light emission operation is held for a certain period until the drawing of the display data on the screen elapses, that is, before the next light reception operation, and the entire display unit 1 is not emitted from the light emitting areas 51A and 51B. This represents a situation where the area 52 is separated.

  Next, with reference to FIG. 2, FIG. 4, FIG. 5, and FIG. 7, details of processing for detecting the detection target object 15 in the image display apparatus of FIG. 1 will be described. FIG. 7 shows processing for detecting the detection target object 15 in the image display device of FIG. 1, and (D) a light emitting / receiving cell CWRi (CWRi1 to CWRin) for one vertical line, and each of these light emitting / receiving units. Each of (A) data supply line DWi, (B) light emission gate lines G (G1 to Gn), (C) switching lines S (S1 to Sn) and (E) data read lines DRi connected to the cell CWRi. The signal is shown. In FIG. 7, i and j, which are codes representing positions, represent certain natural numbers. As described above, for example, in the case of an XGA standard display unit (m = 1024 × 3 (RGB), n = 768), for example, the display unit I = 1536, j = 384. The same applies to the subsequent timing diagrams.

  In FIG. 7, the horizontal axis represents time, and the vertical periods TH1 and TH2 are the time required for scanning the entire screen of the display unit 1, that is, in this case, the light emitting side scanner 24 and the light receiving signal selection scanner 31 are respectively G1 to It represents the time to scan up to Gn and S1 to Sn. Here, assuming that the detection target object 15 is in the vicinity of the light emitting / receiving cells CWRij, CWRi (j + 1), and CWRi (j + 2) in the display unit 1, the timing in the corresponding period, that is, the vertical period TH1. The light reception signal is detected in the period from t3 to t6 (light reception signal detection period TF1), and the light reception signal is detected in the light reception signal detection period TF2 in the vertical period TH2. The vertical axis represents the voltage at each timing of each signal shown in (A) to (C) and (E) above. Here, it is assumed that the signal of the data supply line DWi shown in (A) is display data corresponding to an arbitrary luminance in each pixel 11 and an arbitrary image is displayed on the display unit 1. Moreover, the light emission period TW and the light reception period TR in each light emission / reception cell CWRi shown to (D) are represented. A period other than the light emission period TW and the light reception period TR is a non-operation period. Note that the first section (thick frame portion) of the light emission period TW is a period during which light emission driving based on image data is performed (period in which the first switch SW1 in FIG. 4 is on). The period other than is a period in which the light emission state is held by the capacitor C in FIG.

  The signal of the data read line DRi shown in (E) is an example stored in the light reception signal holding unit 33 as analog data, but as described above, it is stored in the light reception signal holding unit 33 as digital data. It is also possible to configure.

  First, selection signals are not output in all the light emitting gate lines G and the switching lines S, and any one of the first switch SW1, the second switch SW2, and the third switch SW3 in each light emitting and receiving cell CWR. Also, the data supply line DW and the data read line DR are disconnected from the light emitting / receiving element EL. Therefore, during this period, each light emitting / receiving cell CWR is in a non-operating state.

  At timing t0, (C) a switching signal is output on the switching line S1, and the third switches SW3 in the light emitting and receiving cells CWR11, CWR21,..., CWRm1 to which the switching line is connected are turned on all at once. A light receiving operation is performed in the light receiving cell. Note that the first switch SW1 and the second switch SW2 in these light emitting and receiving cells remain off. At this time, as indicated by the light receiving period TR in FIG. 7, (D) in the light emitting / receiving cell CWRi, the current corresponding to the amount of light received by the light emitting / receiving element EL shown in FIG. A light receiving operation is performed by being supplied to the data read line DRi. Note that, during this period (timing t0 to t1), the light reception signal by the detection target object 15 is not detected, so that no output signal is output from the (E) data read line DRi.

  Next, at timing t1, a selection signal and a switching signal are output from (B) light emission gate line G1 and (C) switching line S2, respectively. Therefore, (B) in the light emitting / receiving cells CWR11, CWR21,..., CWRm1 to which the light emitting gate line G1 is connected, the first switch SW1 and the second switch SW2 are simultaneously turned on and at timings t0 to t1. The third switches SW3 that were in the on state in FIG. 5 are turned off all at once, and the light emitting operation is performed in these light emitting and receiving cells. However, since the light receiving signal by the detection target object 15 is not detected, (E) the data read line DRi Does not output an output signal.

  Similarly, after the timing t2, the light emission operation and light reception are sequentially performed in the order of (B) light emission gate line G2 and (C) switching line S3, (B) light emission gate line G3 and (C) switching line S4,. Although the operation is performed, since the light reception signal by the detection target object 15 is not detected, the output signal is not output from the data read line DRi. Each light emitting / receiving cell CWRi holds the light emission period TW for a certain period as described above.

  At timings t3 to t6, (D) the respective light emitting / receiving cells CWRij, CWRi (j + 1), and CWRi (j + 2) receive the reflected light from the detection target object 15, and receive the light as shown in FIG. The current corresponding to the amount of light is converted into a voltage, and (E) is output to the data read line DRi (light reception signal detection period TF1). In this case, mainly (D) each light emitting / receiving cell CWRij, CWRi (j + 1), CWRi (j + 2) is CWRi (j-1), CWRij, CWRi arranged on the next horizontal line. Since the reflected light from the emitted light by the light emission operation of (j + 1) is received, the signal output to (E) the data read line DRi is a value corresponding to the signal on the (A) data supply line DWi. It has become.

  After timing t6, similarly to timings t1 to t3, (B) light emission gate line Gj + 2 and (C) switching line Sj + 3, (B) light emission gate line Gj + 3 and (C) switching line Sj + 4,... (B) The light emission operation and the light reception operation are sequentially performed with the light emission gate line Gn-1 and (C) the switching line Sn. However, since the light reception signal by the detection target object 15 is not detected, (E ) No output signal is output from the data read line DRi.

  In this way, it is possible to detect that the detection target object 15 exists at a position near the light emitting / receiving cells CWRij, CWRi (j + 1), and CWRi (j + 2) in the vertical period TH1. In the vertical period TH2, for example, in the vertical period TH2, the output signal is output from the data read line DRi in the light reception signal detection period TF2, and the light receiving cells CWRij, CWRi (j + 1), CWRi are output. It is detected that the detection target object 15 exists at a position near (j + 2).

  As described above, according to the image display device and the driving method of the image display device of the present embodiment, the configuration in which the plurality of light emitting / receiving cells CWR including the light emitting / receiving cell CWR including one light emitting / receiving element EL are arranged. The light emitting side scanner 24 and the display signal driver 23 drive these light emitting / receiving elements EL based on the image data generated by the display signal generating section 21 and emit light from the light emitting / receiving elements. The light receiving signal selection scanner 31 drives the other light emitting / receiving element EL so as to receive the light reflected by the detection target object 15, and the position detecting unit based on the light receiving signal obtained by the light receiving signal receiver 32 from the other light receiving element. Since the detection target object 15 is detected in 34, it is not necessary to add a separate component such as a touch panel or an input device, and a simple configuration is possible. While ensuring, furthermore it is possible that the light emitted from the display unit 1 without causing deterioration of the image quality since the need to transmit a separate part eliminated such as a touch panel, for detecting the position or the like of an object.

  Further, according to the image display device and the driving method of the image display device of the present embodiment, each light emitting / receiving cell CWR performs the line sequential light emitting operation and the line sequential light receiving operation. Image data can be displayed and the position of an object can be detected.

  In addition, according to the image display device and the driving method of the image display device of the present embodiment, the position or the like is detected by contacting or bringing a detection target object such as a finger on the display unit 1. The user can operate conveniently with the same operation as the touch panel.

  Further, according to the image display device and the driving method of the image display device of the present embodiment, both the light emitting operation and the light receiving operation are performed in a time division manner in the light emitting / receiving cell CWR including one light emitting / receiving element EL. Therefore, the light emitting operation and the light receiving operation can be performed with a simple element structure without the need to separately install the light emitting element and the light receiving element, and the manufacturing process can be simplified.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.

  In the first embodiment, the image display apparatus having the configuration in which the light emitting operation is held for a certain period until the next light receiving operation has been described. In the present embodiment, the image display device immediately before the next light receiving operation is performed. An image display device configured to emit light until a period will be described.

  FIG. 8 shows the overall configuration of an image display apparatus according to the second embodiment of the present invention. In this figure, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. This image display device includes a display unit 101, a display signal generation unit 21, a display signal holding control unit 22, a display signal driver 23, a light emission side scanner 24, a light reception signal selection scanner 31, and a light reception signal receiver 32. The light receiving signal holding unit 33 and the position detecting unit 34 are provided. That is, the display unit 101 is provided instead of the display unit 1 in the first embodiment shown in FIG.

  Similar to the display unit 1, the display unit 101 includes a plurality of pixels 11 arranged in a matrix over the entire surface, and displays an image such as a predetermined figure or character while performing a line sequential operation. The difference from the display unit 1 is that the light emitting operation is performed until the period immediately before the next light receiving operation as described above. In other words, as described above, the capacitance value of the capacitor C in the circuit configuration of the light emitting / receiving cell CWR is changed to extend the light emission period.

  Next, an operation for detecting an object in contact with or close to the image display apparatus having the above-described configuration will be described.

  FIG. 9 illustrates an example of the line sequential light emitting operation and the line sequential light receiving operation in the image display apparatus of FIG. 8, and corresponds to FIG. 6 in the first embodiment. In this figure, the same components as those shown in FIG. 6 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  In the example of the line-sequential light emission operation shown in FIG. 9A, as in the example of FIG. 6A, for example, one horizontal line at the position indicated by the arrow P2 is sequentially emitted in the direction indicated by the scan direction X. It represents the situation of doing. Also, in this example, unlike the example of FIG. 6A, one horizontal line at the position indicated by the arrow P2 is displayed until the drawing by the display data is completed on the screen, that is, the next image data is the display signal driver 23. The light emitting operation is maintained until the light is supplied by the above-described state, and the entire display unit 1 is the light emitting region 51. In this way, one horizontal line at the position indicated by the arrow P2 performs a line sequential light emission operation, so that the entire display unit 1 becomes a light emitting region except for the light receiving line, and certain image data is displayed over the entire display unit 1. It becomes possible.

  Next, in the example of the line-sequential light emitting operation and the line-sequential light receiving operation shown in FIGS. 9B and 9C, the positions indicated by arrows P2 and P5, for example, as in the examples of FIGS. 9B and 9C. The one horizontal line sequentially emits light in the direction indicated by the scan direction X, and the one horizontal line at the position indicated by arrows P3 and P6 reflects the light reflected from the detection target object 15 by the light emitted from the light emitting region. This represents a situation in which a light-sequential light receiving operation is performed in the direction indicated by the scan direction X. However, the difference from the example of FIGS. 9B and 9C is that one horizontal line at the position indicated by arrows P3 and P6 is not only the light emitting area 51A at the upper position but also the light emitting area at the lower position. This is the point that light reflected from the light emitted from 51B is also received. In this way, by changing the capacitance value of the capacitor C in the circuit configuration of the light emitting / receiving cell CWR and extending the light emission period, one horizontal line always detects the position of the object by the line sequential light receiving operation. Light emitted from one horizontal line at the upper and lower positions can be used as a light source.

  FIG. 10 shows processing for detecting the detection target object 15 in the image display apparatus of FIG. Note that the basic operation of the driving method of the image display device in the present embodiment is the same as the basic operation of the driving method of the image display device in the first embodiment, so that the description thereof is omitted and the light emission period TW is omitted. Only the operation related to extension will be described.

  First, in the vertical period TH1, the operation is the same as that in the case of the first embodiment shown in FIG. In the vertical period TH2, as described above, the light emitting / receiving cell CWR has the light emitting period TW until just before the light receiving period TR. Specifically, for example, in the case of the first embodiment (FIG. 7), the light-emitting / receiving cell CWRi1 is in a non-operation period at timings t7 to t8, but in this embodiment, at the timings t7 to t8. Becomes the light emission period TW. As a result, the light emission period TW is from timing t1 to t8 (that is, until immediately before the light reception period TR). For example, in the case of the light emitting / receiving cell CWRij, at timings t11 to t12, the light emitting / receiving cells CWRi (j-1) and CWRi (j + 1) on the upper and lower horizontal lines are both in the light emitting period TW. That is, the light emitted from the light emitting / receiving elements on the upper and lower two horizontal lines of the light emitting / receiving cell driven to receive light can be used as the light source. In other words, the state of one light-emitting / receiving element transitions repeatedly without going through the extinguishing period, such as “light emission” → “light reception” → “light emission” → “light reception”. Light emitted from the light emitting / receiving elements on the upper and lower horizontal lines sandwiching the horizontal line and reflected by the detection target object 15 is incident on the light emitting / receiving element. Since the total sum of the emitted light used as the light source increases, as shown in FIG. 10E, the signal amount of the received light signal on the data read line DRi increases as compared with the first embodiment (FIG. 7). The light receiving sensitivity is improved. In this case, if there is a difference in display data (video data) between fields, there is a possibility that the received light signal does not correspond to the original display data, but data that is not very different between fields is not displayed. By devising in this way, it is possible to avoid this problem. A normal video signal has such characteristics (there is almost no difference in video data between fields). For example, in the MPEG (Motion Picture Experts Group) method, compression is performed using this characteristic. .

  Thus, according to the image display device and the driving method of the image display device in the present embodiment, the light emission operation is performed until the period immediately before the next light reception operation, so that the emitted light used as the light source increases. In addition to the effects of the first embodiment, it is possible to increase the signal amount of the received light signal to improve the S / N ratio and increase the detection sensitivity.

  The first and second embodiments will be described below with some modifications. These modifications can be applied to any of the first and second embodiments, but in the following description, the description will proceed based on the first embodiment.

[Modification 1]
First, a first modification common to the first and second embodiments will be described. In this modification, in the first embodiment, driving is performed by thinning the light receiving drive with respect to the light emitting drive.

  FIG. 11 illustrates the overall configuration of the image display apparatus according to the first modification, and corresponds to FIG. 1 in the first embodiment. In this figure, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. This image display device includes a display unit 1, a display signal generation unit 21, a display signal holding control unit 22, a display signal driver 23, a light emission side scanner 24, a light reception signal selection scanner 311, and a light reception signal receiver 32. The light receiving signal holding unit 33 and the position detecting unit 34 are provided. That is, instead of the light reception signal selection scanner 31 in the first embodiment shown in FIG. 1, a light reception signal selection scanner 311 is provided.

Similar to the light reception signal selection scanner 31, the light reception signal selection scanner 311 switches between light emission drive and light reception drive of the light emission light reception cell CWR in accordance with the light reception timing control signal 42 output from the display signal holding control unit 22, thereby receiving light. The light emitting / receiving cell CWR to be driven is selected. The difference from the light reception signal selection scanner 31 is that the light reception side scanner 311 is thinned and driven with respect to the light emission side scanner 24 as described above. More specifically, as described later, the light-emitting side scanner 24 scans the light-emitting gate lines G with G1, G2, G3,. The scanner 311 scans the switching lines S every other line as S2, S4, S6,..., Sn, and the remaining switching lines S1, S3, S5,. . As described above, the display unit 1 is assumed to be an even number, for example, in the case of the XGA standard (m = 1024 × 3 (RGB), n = 768). For convenience, j is an odd number.

  FIG. 12 shows a process of detecting the detection target object 15 in the image display apparatus of FIG. 11, and corresponds to FIG. 7 in the first embodiment. The basic operation of the image display apparatus driving method according to the present modification is the same as the basic operation of the image display apparatus driving method according to the first embodiment. Only the operation will be described.

  As described above, (B) the light emission gate line G outputs selection signals G1, G2, G3,..., Gn as in the first embodiment, whereas (C) the switching line S , S2, S4,..., Sj-1, Sj + 1,..., Sn, and outputs switching signals every other line and switches to the remaining switching lines S1, S3, Sj,. No signal is output. Therefore, the output signal of the data read line DR is also thinned out corresponding to the switching line S. For example, the light reception signal is not detected during the period from timing t1 to t2, t3 to t4, t5 to t6, and the timing t4 to t5, for example. During this period, etc., the received light signal is detected, and the data amount of the received light signal can be reduced.

  As described above, according to the image display device and the driving method of the image display device according to the present modification, the light reception signal selection scanner 31 is driven to be thinned out and driven with respect to the light emission side scanner 24. In addition to the effects of the embodiment, the amount of light reception signal data can be reduced, the light reception side circuit (light reception signal selection scanner 311, light reception signal receiver 32, light reception signal holding unit 33) can be simplified, and low power consumption can be achieved. It becomes possible. Therefore, it is particularly effective when it is desired to simplify the circuit configuration and reduce the power consumption rather than the accuracy of the detection position of an object that is in contact with or close to the object.

  In this modification, the example of scanning only even-numbered light receiving gate lines has been described. However, the configuration of this modification is not limited to this, and the circuit on the light receiving side is simplified to reduce power consumption. Other configurations are possible as long as they can be realized. For example, on the contrary, only odd-numbered light receiving gate lines may be scanned, or light receiving gate lines may be scanned every two or three lines, for example. As another method for performing “decimation” as in this modification, a method of reducing the number of light-receiving signal scanners by combining pixel outputs is also conceivable. For example, if the outputs of two vertical pixels are combined, the amount of signal that can be extracted is doubled, and the light receiving sensitivity is improved.

[Modification 2]
Next, a second modification common to the first and second embodiments will be described. In this modification, the comparator 35 is arranged between the light receiving signal receiver 32 and the light receiving signal holding unit 33 in the first embodiment.

  FIG. 13 illustrates an overall configuration of an image display apparatus according to the second modification, and corresponds to FIG. 1 in the first embodiment. In this figure, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. This image display device includes a display unit 1, a display signal generation unit 21, a display signal holding control unit 22, a display signal driver 23, a light emission side scanner 24, a light reception signal selection scanner 31, and a light reception signal receiver 32. , A comparator 35, a received light signal holding unit 33, and a position detection unit 34.

  The comparator 35 has a function of performing A / D conversion by comparing the light reception signal output from the light reception signal receiver 32 with a threshold voltage signal Vt that is a predetermined voltage output from the display signal holding control unit 22. Have. Specifically, as will be described later, the received light signal is converted into digital data such as 1 when the received light signal is higher than the threshold voltage signal Vt and 0 when the received voltage is lower than the threshold voltage signal Vt. . Further, the data (comparator output signal Vc) converted into the digital data is output to the received light signal holding unit 33.

  FIG. 14 shows a process of detecting the detection target object 15 in the image display apparatus of FIG. 13 and corresponds to FIG. 7 in the first embodiment. In this figure, (D) light emitting / receiving cells CWRi (CWRi1 to CWRin) for one vertical line, and (A) data supply lines DWi, (B) connected to these light emitting / receiving cells CWRi. Each of the light emission gate lines G (G1 to Gn) and (C) switching lines S (S1 to Sn), (E) data read line DRi, (F) threshold voltage signal Vt, (G) comparator output signal Vci The signal is shown.

  The basic operation of the driving method of the image display device in the present modification is the same as the basic operation of the driving method of the image display device in the first embodiment, and the difference is that the light receiving signal receiver 32 and the light receiving operation as described above. The comparator 35 is disposed between the signal holding unit 33 and the comparator output signal Vc, that is, the input signal to the light receiving signal holding unit 33 is digital data. Therefore, if (E) the signal amount on the data read line DRi is larger than the predetermined (F) threshold voltage signal Vt, (G) the comparator output signal Vci becomes 1, conversely (E) on the data read line DRi. If the signal amount is smaller than the predetermined (F) threshold voltage signal Vt, (G) the comparator output signal Vci is zero. In this manner, as in the case of the first embodiment shown in FIG. 7, the light receiving signals are obtained in the light receiving signal detection periods TF1 and TF2, so that the light emitting and receiving cells CWRij, CWRi (j + 1), CWRi ( It can be detected that the detection target object 15 exists at a position near j + 2).

  As described above, according to the image display device and the driving method of the image display device in this modification, the comparator 35 is arranged between the light reception signal receiver 32 and the light reception signal holding unit 33. Since the data handled by the unit 33 and the position detection unit 34 is digital data, in addition to the effects of the first embodiment, the processing load is suppressed in these blocks, and the circuit configuration is simplified and the power consumption is reduced. It becomes possible.

  FIG. 15 illustrates another overall configuration example of the image display device according to the second modification. This example has a configuration in which a shift register 36 is further arranged between the light receiving signal receiver 32 and the comparator 35 in the second modification shown in FIG. In this figure, the same components as those shown in FIG. 13 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. This image display device includes a display unit 1, a display signal generation unit 21, a display signal holding control unit 22, a display signal driver 23, a light emission side scanner 24, a light reception signal selection scanner 31, and a light reception signal receiver 32. , A shift register 36, a comparator 351, a light reception signal holding unit 33, and a position detection unit 34.

  The shift register 36 sequentially selects the light reception signal output from the light reception signal receiver 32 by the shift register in accordance with the light reception block control signal 43 output from the light reception signal selection scanner 31, and performs parallel / serial conversion to perform a comparator. 351 has a function of outputting to 351. Specifically, the number of comparators is reduced from m to 1 compared to the configuration of FIG. 13 by outputting the received light signal, which is parallel data for m outputs, to the comparator 351 as serial data for one output. It becomes possible to do.

  The comparator 351 uses the received light signal output from the shift register 36 and subjected to parallel / serial conversion as described above to a predetermined voltage output from the display signal holding control unit 22, as in the comparator 35. Compared with the value voltage signal Vt, it has a function of performing A / D conversion. Further, the data (comparator output signal Vc) converted into the digital data is output to the received light signal holding unit 33.

  As described above, according to the image display device and the driving method of the image display device in FIG. 15, the shift register 36 is further arranged between the light receiving signal receiver 32 and the comparator 351 in the second modification shown in FIG. 13. As a result, in addition to the effects of the second modification, the number of comparators is reduced, the processing load in these blocks can be reduced, and the circuit configuration can be simplified and the power consumption can be reduced. Become.

  Here, the effect when this threshold value is changed will be described.

  FIG. 16 shows an example of the distribution of the signal amount of the received light signal. Each light emitting / receiving cell (CWR (i-4) (j-5) to CWR (i + 4)) with the light emitting / receiving cell CWRij as the center is shown. This shows the area (j + 5)).

  In this example, the light receiving signal 61 in the light emitting / receiving cell CWRij has a light receiving signal level of 9, light emitting / receiving cells CWRi (j-1), CWR (i + 1) j, CWRi (j + 1), CWR (i-1). The light receiving signals 62A to 62D at j have a light receiving signal level of 5, light emitting / receiving cells CWR (i + 1) (j-1), CWR (i + 1) (j + 1), CWR (i-1) (j +1), CWR (i-1) (j-1), the light receiving signals 63A to 63D have a light receiving signal level of 3, light emitting / receiving cells CWR (i + 2) j, CWRi (j + 2), CWR (i -2) The light reception signals 64A to 62C in j and the light reception signals in CWRi (j-2) (not shown) have a light reception signal level of 1, and the light reception signal level increases as the position moves away from the light emitting / receiving cell CWRij. The distribution is such that becomes smaller. As described above, by comparing the signal amount of each received light signal with a certain threshold voltage Vt in the position detection unit 34 or the comparators 35 and 351, it is possible to determine at which position the object that is in contact with or close to is present. Can be detected.

FIG. 17 shows a case where the threshold value is changed in the signal amount distribution of the received light signal in FIG. FIGS. 17A , 17B, and 17C show the cases where the threshold voltage Vt in FIG. 16 is the light reception signal level 2, the light reception signal level 4, and the light reception signal level 6, respectively. The regions indicated by the light receiving signal detection regions 65 to 67 are regions where the signal amount of the light receiving signal in the light emitting / receiving cell CWR at that position is larger than the threshold voltage Vt, and an object is detected at that position. It represents what has been done.

  Thus, as the light reception signal level of the threshold voltage is increased in the order of (A) → (B) → (C), the area of the region where the object is detected is centered on the position of the light emitting / receiving cell CWRij. You can see that it gets smaller. Thus, for example, the user can describe the object properties (size, surface condition (reflectance, color, roughness, etc.)), detection purpose (position detection, size detection, color detection, etc.) By arbitrarily changing the threshold voltage Vt depending on the accuracy or the like, it becomes possible to perform more accurate and convenient position detection.

[Modification 3]
Next, a third modification common to the first and second embodiments will be described. The reflected light when an object is in contact with or close to the object is large if the light emission amount in the light emitting / receiving cell CWR is high, and is small if the light emission amount in the light emitting / receiving cell CWR is low. Therefore, a certain light emitting / receiving cell C
Depending on how much light is emitted from the WR, the signal amount of the light reception signal detected by the other light emitting / receiving cells also varies. Therefore, in this modification, the shift register 36 and the comparator 351 are arranged between the light receiving signal receiver 32 and the light receiving signal holding unit 33 in the first embodiment, and the display output from the display signal holding control unit 22 is further provided. A threshold voltage generation unit 37 that generates a threshold voltage Vt in the comparator 351 based on the signal 45 is arranged. That is, the image display apparatus shown in FIG. 15 has a configuration in which a threshold voltage generation unit 37 that generates the threshold voltage Vt is added.

  FIG. 18 illustrates an overall configuration of an image display device according to the third modification, and corresponds to FIG. 1 in the first embodiment. In this figure, the same components as those shown in FIGS. 1 and 15 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. This image display device includes a display unit 1, a display signal generation unit 21, a display signal holding control unit 22, a display signal driver 23, a light emission side scanner 24, a light reception signal selection scanner 31, and a light reception signal receiver 32. , A shift register 36, a comparator 351, a threshold voltage generation unit 37, a light reception signal holding unit 33, and a position detection unit 34.

  The threshold voltage generation unit 37 has a function of generating a threshold voltage Vt in the comparator 351 based on the display signal 45 in each pixel 11 output from the display signal holding control unit 22 and outputting the threshold voltage Vt to the comparator 351. Therefore, the threshold voltage Vt corresponding to the light emitted from the light emitting / receiving cell CWR in each pixel 11 can be set for each pixel in the comparator 351.

  FIG. 19 shows a process of detecting the detection target object 15 in the image display apparatus of FIG. 18, and corresponds to FIG. 7 in the first embodiment and FIG. 14 in the second modification. Further, in this figure, as in FIG. 14, (D) light emitting / receiving cells CWRi (CWRi1 to CWRin) for one vertical line, and (A) data supply line DWi connected to each of these light emitting / receiving cells CWRi. , (B) light emission gate lines G (G1 to Gn) and (C) switching lines S (S1 to Sn), (E) data read lines DRi, (F) threshold voltage signal Vt, (G) comparator output Each signal of the signal Vci is shown. Note that the basic operation of the driving method of the image display apparatus in the present modification is the same as the operation shown in FIG. 14, and therefore the description thereof is omitted, and only the operations relating to the threshold voltage generator 37 and the comparator 351 are described. To do.

  The basic operation of the driving method of the image display apparatus in this modification is the same as the basic operation of the driving method of the modification 2 shown in FIG. 14, and the difference is that the output from the display signal holding control unit 22 is as described above. The threshold voltage Vt in the comparator 351 is generated based on the display signal 45 in each of the pixels 11. Therefore, in the second modification shown in FIG. 14, the threshold voltage Vt is a constant value, whereas in this modification, the threshold voltage signal Vt corresponds to (A) the data supply line DWi. It is a variable value. Of course, also in this case, if the signal amount of (E) the data read line DRi is larger than the predetermined (F) threshold voltage signal Vt, (G) the comparator output signal Vci becomes 1, conversely (E) the data read If the signal amount of the line DRi is smaller than the predetermined (F) threshold voltage signal Vt, (G) the comparator output signal Vci becomes zero. In this manner, as in the case of the first embodiment shown in FIG. 7, the light receiving signals are obtained in the light receiving signal detection periods TF1 and TF2, so that the light emitting and receiving cells CWRij, CWRi (j + 1), CWRi ( It can be detected that the detection target object 15 exists at a position near j + 2).

  In this way, according to the image display device and the driving method of the image display device in the present modification, the threshold voltage generation unit 37 is further added to the image display device shown in FIG. The threshold voltage Vt of the comparator 351 is changed in accordance with the display signal of each pixel so that the threshold voltage is increased if the threshold is high, and the threshold voltage is decreased if the amount of light emission is low. In addition to the effect of the image display device shown in FIG. 15, it is possible to more accurately detect the position of an object that is in contact with or close to.

[Modification 4]
Next, a fourth modification common to the first and second embodiments will be described. The surface of the display unit 1 of the image display device is irradiated with ambient light in addition to the reflected light from an object in contact with or in close proximity. Therefore, in this modification, the comparator 35 is disposed between the light reception signal receiver 32 and the light reception signal holding unit 33 in the first embodiment, and the comparator is further based on the light reception signal VR output from the light reception signal receiver 32. The threshold voltage generator 371 for generating the threshold voltage Vt at 35 is arranged. In other words, the threshold voltage generation unit 371 is added in the second modification shown in FIG. 13, thereby performing the process of removing the influence of ambient light when detecting the light reception signal by the light emitting / receiving element EL. It is what I did.

  FIG. 20 illustrates an overall configuration of an image display device according to the fourth modification, and corresponds to FIG. 1 in the first embodiment. In this figure, the same components as those shown in FIGS. 1 and 13 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. This image display device includes a display unit 1, a display signal generation unit 21, a display signal holding control unit 22, a display signal driver 23, a light emission side scanner 24, a light reception signal selection scanner 31, and a light reception signal receiver 32. , A comparator 35, a threshold voltage generation unit 371, a light reception signal holding unit 33, and a position detection unit 34.

  The threshold voltage generation unit 371 generates a threshold voltage Vt in the comparator 35 based on the light reception signal VR in each pixel 11 for one horizontal line output from the light reception signal receiver 32 and outputs the threshold voltage Vt to the comparator 35. Have Therefore, the comparator 35 can set the threshold voltage Vt corresponding to the reflected light to the light emitting / receiving cell CWR in each pixel 11 for each pixel.

The comparator 35 has a function of performing A / D conversion by comparing the light reception signal output from the light reception signal receiver 32 with the threshold voltage signal Vt output from the threshold voltage generation unit 371. Further, the data (comparator output signal Vc) converted into the digital data is output to the received light signal holding unit 33.

  FIG. 21 shows an example of processing for removing the influence of ambient light in the image display apparatus of FIG. 20, and includes processing (A) to (D). Here, one square shown in FIG. 21 represents the pixel 11 in the display unit 1 as in FIG.

First, in FIG. 21A, areas other than the light receiving area 53 in the entire display portion 1 are black display areas 54A and 54B in advance, and light emission from the light emitting / receiving cell CWR has the lowest luminance. Therefore, the contact light by the light emission from the light emitting / receiving cell CWR or the reflected light from the adjacent object is hardly detected in the other light emitting / receiving cell CWR. Further, while performing a series of processes for removing the influence of the ambient light, an object that is a reflection target is not placed in the vicinity of the image display device, and the other light emitting / receiving cell CWR It is necessary that only the light detected by the ambient light is detected by the ambient light. Here, as described above, for example, one horizontal line at the position indicated by the arrow P1 performs a line-sequential light emission operation in the direction of the scanning direction X, and one horizontal line at the position indicated by the arrow P2 The line sequential light receiving operation is performed in the X direction.

  Next, as in the case of one horizontal line at the positions indicated by arrows P2, P5 and P3, P6 in FIGS. Receives light. At this time, the light reception signal detected in each light emitting / receiving cell CWR is output to the light reception signal receiver 32, and the light reception signal receiver outputs the light reception signal VR for one horizontal line to the threshold voltage generator 371. As described above, the threshold voltage generation unit 371 generates the threshold voltage Vt in the comparator 35 based on the light reception signal VR and outputs the threshold voltage Vt to the comparator 35.

  When the ambient light detection process for one screen is completed, the normal display operation is started on one horizontal line at the position indicated by the arrow P1 in FIG. As 55 increases, a normal light receiving operation is started on one horizontal line at the position indicated by the arrow P2. At this time, the comparator 35 performs A / D conversion of the light reception signal in each pixel 11 by the threshold voltage Vt generated in consideration of the light reception signal VR by the ambient light obtained in (A) to (C). Since it goes, the influence of ambient light can be removed.

  FIG. 22 shows a process for removing the influence of ambient light, and corresponds to FIG. 7 in the first embodiment and FIG. 14 in the second modification. Further, in this figure, as in FIG. 14, (D) light emitting / receiving cells CWRi (CWRi1 to CWRin) for one vertical line, and (A) data supply line DWi connected to each of these light emitting / receiving cells CWRi. , (B) light emission gate lines G (G1 to Gn) and (C) switching lines S (S1 to Sn), (E) data read lines DRi, (F) threshold voltage signal Vt, (G) comparator output Each signal of the signal Vci is shown. Note that the basic operation of the driving method of the image display apparatus in the present modification is the same as the operation shown in FIG. 14, and thus the description thereof is omitted, and only the operations relating to the threshold voltage generation unit 371 and the comparator 35 are described. To do.

  First, as described above, in the vertical period TH1, the entire display unit 1 is the black display region 54, and (A) the signal amount on the data supply line DWi is the smallest value. Accordingly, the light reception signal output from the data read line DRi at the timings t4 to t7 is considered to be due to ambient light. Next, in the vertical period TH2, the threshold voltage Vt is set by the amount of the light reception signal due to the ambient light detected in the vertical period TH1 at the timings t8 to t9 corresponding to the timings t4 to t7 in the vertical period TH1. It is supposed to be added. In this way, the threshold value is set in consideration of the influence of ambient light.

  As described above, according to the image display device and the driving method of the image display device in the present modification, the threshold voltage generation unit 371 is further added in the modification 2 shown in FIG. Since the process of removing the influence of the ambient light is performed when detecting the light reception signal, in addition to the effect of the modified example 2, the influence of the ambient light is also taken into consideration to detect the object that is in contact with or close to it. The position can be detected more accurately.

  In the present modification, the original threshold voltage Vt has been described as an example of a constant value, but the threshold voltage Vt is generated based on the display signal 45 as in the examples of FIGS. The present invention can also be applied to the case where the value is a variable value. In this case, the threshold voltage Vt is generated based on both the display signal 45 and the light reception signal VR.

[Modification 5]
Next, a fifth modification common to the first and second embodiments will be described. In this modification, a plurality of verification objects that are simultaneously arranged at arbitrary positions in the image display device are detected, and the verification objects are also detected at arbitrarily moving positions.

  FIG. 23 illustrates an overall configuration of an image display apparatus according to the fifth modification, and corresponds to FIG. 1 in the first embodiment. In this figure, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. The image display apparatus includes a display unit 1, a display signal generation unit 212, a display signal holding control unit 222, a display signal driver 232, a light emission side scanner 242, a light reception signal selection scanner 312, and a light reception signal receiver 32. The light receiving signal holding unit 33 and the position detecting unit 34 are provided.

  Here, the basic operations of the display signal generation unit 212, the display signal holding control unit 222, the display signal driver 232, the light emission side scanner 242, and the light reception signal selection scanner 312 are respectively the display signal generation unit 21 and the display signal holding control in FIG. Since this is the same as the unit 22, the display signal driver 23, the light emission side scanner 24, and the light reception signal selection scanner 31, description thereof will be omitted.

  The display signal generation unit 212 further includes a function of synthesizing a display signal by replacing a part of the input image data with mark data for displaying a predetermined mark as will be described later. The signal driver 232, the light emitting side scanner 242 and the light receiving signal selection scanner 312 receive the light emitted from the light emitting / receiving cell CWR according to the mark data by the other light receiving / receiving cell CWR corresponding to the position of the light emitting / receiving cell CWR. The light reception signal is detected. In this way, it is possible to detect an object that is in contact with or close to the area where a predetermined mark is displayed.

  FIG. 24 illustrates a case where a plurality of verification objects that are simultaneously arranged at arbitrary positions are detected in the image display apparatus of FIG. Further, in this figure, arbitrary image data is displayed and a plurality of predetermined marks 71 to 74 are simultaneously displayed on the display unit 1 provided in the image display device 7 corresponding to the image display device shown in FIG. Represents the situation.

  In this modification, the light emitted from the light emitting / receiving cell CWR in the display unit 1 is used as a light source for detecting reflected light. Therefore, it is possible to detect contact from an arbitrary position of the display unit 1 or reflected light of an adjacent object. For example, if a button-like image including predetermined marks 71 to 74 is displayed at an arbitrary position on the display unit 1 and the reflected light of the object is detected from this region, the same effect as that of the touch panel can be obtained. it can. Further, in this modification, the position of the object is detected by the light reception signal reconstructed in the light reception signal holding unit 33, so that it is possible to detect a plurality of positions arranged at the same time. Thus, the user can detect a plurality of contacts or objects that are simultaneously arranged at arbitrary positions in the image display apparatus.

  FIG. 25 shows a case where a predetermined mark moves in the image display apparatus of FIG. 23, and corresponds to the image display apparatus 7 shown in FIG. This figure shows a situation in which the mark 74 moves as indicated by an arrow 741 among a plurality of predetermined marks 71 to 74 displayed on the image display device 7 shown in FIG. Moreover, in this figure, the same code | symbol is attached | subjected to the component same as the component shown in FIG. 24, and description is abbreviate | omitted suitably.

  In the present modification, the display signal generation unit 212 has a function of synthesizing a display signal by replacing a part of the input image data with mark data for displaying a predetermined mark as described above. Here, when the input image data is moving image data composed of a plurality of frames, the display signal generation unit 212 marks a part of the input image data at different positions for each frame according to the moving image data. If it is replaced with data, for example, as shown in FIG. 25, the button-like portion is moved, the button-like portion is displayed in the moving image portion, or the button-like portion is displayed as necessary. Can be displayed or deleted.

  Accordingly, the user can detect an object that is in contact with or close to the object even at a position where the image display device arbitrarily moves. In addition, since what kind of image is displayed is determined by the display signal generation unit 212, when a button-like image consisting of a predetermined mark is not displayed, data obtained as a result of position detection is used. If this is not done, erroneous detection can be prevented.

  The present invention has been described above with some embodiments and modifications. However, the present invention is not limited to these, and various modifications can be made. For example, in the above embodiment, the display operation and the light of the adjacent light emitting pixel are detected by repeating “light reception → light emission → light emission” as the operation of each pixel or by repeating “light reception → light emission”. Although the object detection operation is performed in parallel, the present invention is not limited to this, and it is possible to detect the light of the adjacent light emitting pixel even if, for example, “light emission → light reception → light extinction” is repeated.

1 is a block diagram illustrating an overall configuration of an image display device according to a first embodiment of the present invention. It is a block diagram showing an example of a structure of the display part in FIG. FIG. 2 is a cross-sectional view schematically illustrating an example of an arrangement configuration of light emitting and receiving cells in the display unit of FIG. 1. FIG. 3 is a circuit diagram illustrating a configuration of a light emitting / receiving cell in FIG. 2. FIG. 2 is a schematic diagram illustrating an example of processing for detecting a detection target object in the image display apparatus of FIG. 1. It is a figure showing an example of the line sequential light emission operation | movement and line sequential light reception operation | movement in the image display apparatus of FIG. FIG. 2 is a timing diagram of processing for detecting a detection target object in the image display apparatus of FIG. 1. It is a block diagram showing the whole structure of the image display apparatus which concerns on the 2nd Embodiment of this invention. It is a figure showing an example of the line sequential light emission operation | movement and the line sequential light reception operation | movement in the image display apparatus of FIG. FIG. 9 is a timing diagram of processing for detecting a detection target object in the image display device of FIG. 8. 10 is a block diagram illustrating an overall configuration of an image display device according to Modification Example 1. FIG. FIG. 12 is a timing diagram of processing for detecting a detection target object in the image display apparatus of FIG. 11. FIG. 10 is a block diagram illustrating an overall configuration of an image display device according to Modification 2. It is a timing diagram of the process which detects a detection target object in the image display apparatus of FIG. 10 is a block diagram illustrating another overall configuration example of an image display device according to Modification 2. FIG. It is a distribution figure showing an example of the amount of signals of a received light signal. FIG. 17 is a schematic diagram when the threshold value is changed in the signal amount distribution of the received light signal in FIG. 16. FIG. 10 is a block diagram illustrating an overall configuration of an image display device according to Modification 3. FIG. 19 is a timing diagram of processing for detecting a detection target object in the image display device of FIG. 18. It is a block diagram showing the whole structure of the image display apparatus which concerns on the modification 4. It is a schematic diagram showing an example of the process which removes the influence of environmental light in the image display apparatus of FIG. It is a timing diagram of the process which removes the influence of environmental light. 10 is a block diagram illustrating an overall configuration of an image display device according to Modification Example 5. FIG. 24 is a schematic diagram in the case of detecting a plurality of verification objects simultaneously arranged at arbitrary positions in the image display device of FIG. 23. FIG. 24 is a schematic diagram when a predetermined mark moves in the image display apparatus of FIG. 23.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,101 ... Display part, 11 ... Pixel, 12 ... Transparent substrate, 13 ... Partition, 15 ... Object to be detected, 21, 212 ... Display signal generation part, 22, 222 ... Display signal holding control part, 23, 232 ... Display Signal driver, 24, 242 ... Light emitting side scanner, 31, 311, 312 ... Light receiving signal selection scanner, 32 ... Light receiving signal receiver, 33 ... Light receiving signal holding unit, 34 ... Position detection unit, 35, 351 ... Comparator, 36 ... Shift Registers 37, 371 ... Threshold voltage generator 41 ... Light emission timing control signal 42 ... Light reception timing control signal 43 ... Light reception block control signal 45 ... Display signal 51 ... Light emission region 52 ... Non light emission region 53 ... Light receiving area, 54 ... Black display area, 55 ... Normal display area, 61 to 64 ... Light reception signal detection level, 65 to 67 ... Light reception signal detection area, 7 ... Image display device , 71-74 ... Mark, 741 ... Mark movement status, CWR ... Light emitting / receiving cell, G ... Light emitting gate line, S ... Switching line, DW ... Data supply line, DR ... Data read line, LW, LW1 ... Emission light , LR1 ... reflected light, EL ... light emitting / receiving element, C ... capacitor, R ... resistor, SW1 ... first switch, SW2 ... second switch, SW3 ... third switch, I1 ... display signal current path, I2 ... Light reception signal current path, X: scan direction, P1, P2, P3, P5, P6 ... line position during scanning, TH1, TH2 ... vertical period, TW ... light emission period, TR ... light reception period, TF1, TF2 ... light reception signal Detection period, t0 to t14 ... timing, Vt ... threshold voltage signal, Vc ... comparator output signal, VR ... light reception signal.

Claims (19)

A plurality of light emitting / receiving elements each having both a light emitting function and a light receiving function;
A light emission driving means for driving the light emitting / receiving element to emit light based on image data;
Light receiving drive for receiving and driving the other light emitting / receiving element so that the other light emitting / receiving element receives the light emitted from one light emitting / receiving element emitting light based on the image data and reflected by the object to be detected. Means,
A comparator that performs A / D conversion by comparing a light receiving signal obtained from the other light emitting and receiving element with a predetermined threshold;
Threshold generation for changing the threshold value in the comparator so that the value increases as the light emission amount increases and the value decreases as the light emission amount decreases according to the content of the image being displayed. And
Based on a photodetection signal after A / D conversion is made by said comparator, and a detecting means for detecting the detection target object,
The light emission driving means and the light receiving drive means drive each light emitting / receiving element so that another one light emitting / receiving element performs a light receiving operation corresponding to the light emitting operation of the plurality of light emitting / receiving elements. A shift register that performs parallel / serial conversion on a light reception signal obtained from the other light emitting / receiving element ;
The comparator includes a light receiving signal after parallel / serial conversion has been performed by the shift register, intends row A / D conversion in comparison with the threshold value
The image display apparatus according to 請 Motomeko 1. The detection means includes
Based on the light reception signal obtained from the other light emitting and receiving elements when black display is performed in a state where the detection target object is not approaching the light emitting and receiving element, the intensity of ambient light existing in the surroundings is obtained,
Based on the light reception signal after A / D conversion has been performed using a separatory only plus threshold of intensity of the ambient light, the image display apparatus according to claim 1 for detecting the detection target object. The image display device according to claim 1, wherein the detection unit detects at least one of a position and a size of a detection target object based on the light reception signal. The image display device according to claim 1, wherein the detection unit detects a plurality of detection target objects arranged simultaneously based on the light reception signal. The detection means sets a threshold value according to the property of the detection target object or the purpose or accuracy of the detection, and detects the detection target object by comparing the light reception signal with the threshold value. 2. The image display device according to 1. The plurality of light emitting / receiving elements are arranged in a matrix,
The light emission driving means drives the plurality of light emitting and receiving elements to emit light in a line sequential manner,
The image display device according to claim 1, wherein the light receiving drive unit performs light receiving driving of light emitting / receiving elements other than the light emitting / receiving element that is emitting light in line sequential manner in synchronization with the line sequential light emitting operation of the light emitting / receiving element. The image display apparatus according to claim 7 , wherein the light receiving drive unit receives and drives a light emitting / receiving element at a corresponding position belonging to a line next to a line to which the light emitting / receiving element in a light emitting operation belongs. The image display apparatus according to claim 7 , wherein the light emission driving unit emits light to light emission / reception elements respectively belonging to two lines adjacent to both sides of a line to which a light emission / reception element to which light reception driving is performed by the light reception driving unit. . The image display device according to claim 1, wherein the light emitting and receiving element is an organic EL element. For one light emitting / receiving element,
One light emitting gate line for selecting a light emitting / receiving element as a driving target;
One data supply line for supplying the image data to the light emitting and receiving element;
One data readout line for reading out the light receiving signal from the light emitting / receiving element;
The image display device according to claim 1, wherein a switching line for switching between light emission driving and light reception driving of the light emitting / receiving element is connected. For each light emitting / receiving element,
A capacitor;
A first switch for selectively conducting between the data supply line and one end of the capacitor in response to a selection signal supplied from the light emission gate line;
A second switch for selectively conducting between the other end of the capacitor and the light emitting / receiving element in response to a switching signal supplied from the switching line;
In response to said switching signal, the image display apparatus according to claim 1 1, a third switch for selectively conducting is provided between the data read lines and the light emitting light receiving element. By the capacitor, the image display apparatus according to claim 1 2 to emit the light emitting light receiving element immediately before receiving the drive start. Image synthesizing means for synthesizing the image data by replacing a part of the input image data with mark data for displaying a predetermined mark;
The light emission drive means and the light reception drive means cause the light emitted from the light emission / reception element driven according to the mark data in the image data to be emitted by another light emission / reception element at a position corresponding to the light emission / reception element. Driving the light emitting / receiving element to receive light;
The detection means approaches the detection target object to the mark being displayed based on a light receiving signal obtained from the other light emitting / receiving element that receives light emitted from the light emitting / receiving element driven according to the mark data. The image display apparatus according to claim 1, wherein it is detected whether or not it has been performed. The image composition means replaces a part of the input image data with mark data for displaying the mark at a plurality of positions,
The detection means includes any one of marks displayed at a plurality of positions based on a light reception signal obtained from the other light emission / reception element that has received light emitted from a light emission / reception element driven according to the mark data. the image display apparatus according to claim 1 4, wherein the detection target object to mark the position of detecting whether approached. The input image data is moving image data composed of a plurality of frames,
The image synthesizing means, the image display apparatus according to a portion of the input image data for each frame to claims 1-4 replaced with the mark data. The image display device according to claim 16 , wherein the image synthesizing unit replaces a part of the input image data with the mark data at positions different from each other in each frame. The image display device according to claim 17 , wherein the image synthesizing unit replaces a part of the input image data with the mark data at positions different from each other in accordance with contents of the input image data. A method for driving an image display device, comprising:
A plurality of light emitting / receiving elements each having both a light emitting function and a light receiving function are arranged,
Based on the image data, the light emitting / receiving element is driven to emit light,
The other light emitting / receiving element is driven to receive light so that the other light emitting / receiving element receives the light emitted from one light emitting / receiving element emitting light based on the image data and reflected by the detection target object,
A / D conversion is performed by comparing a light receiving signal obtained from the other light emitting / receiving element with a predetermined threshold value,
According to the content of the image being displayed, the threshold value is changed so that the value increases as the light emission amount increases and the value decreases as the light emission amount decreases,
While detecting the detection target object based on the light reception signal after the A / D conversion ,
A driving method for an image display device, wherein each light emitting / receiving element is driven so that another one light emitting / receiving element performs a light receiving operation in response to a light emitting operation of a plurality of light emitting / receiving elements.

Images