JP5046879B2 - Coordinate pattern, coordinate pattern display device and reading device - Google Patents

Description

  The present invention relates to a two-dimensional coordinate pattern displayed on a display surface of a display panel, a display device for the coordinate pattern, and a reading device for the coordinate pattern.

  Currently, various information codes such as a QR (Quick Response) code are used as a two-dimensional code representing n-bit information data in a two-dimensional image pattern. In recent years, a coordinate input system has been proposed in which a light pen is brought into contact with a display screen of a display so that the coordinate position in the display screen touched by the light pen can be detected (see, for example, Patent Document 1). . In such a coordinate input system, a two-dimensional code representing each coordinate position in the display display screen is displayed in a matrix on the corresponding coordinate position. At this time, the light pen captures the coordinate position on the display screen in contact with the light pen by photographing the two-dimensional code pattern displayed on the display screen of the display at the touched position. I am doing so.

  FIG. 1 is a diagram showing a coordinate pattern displayed on a display in the coordinate input system.

  The coordinate pattern shown in FIG. 1 is composed of a plurality of blocks each representing one coordinate position with 6 dots in the horizontal direction and 6 dots in the vertical direction. The 6 dots at the left end and the 6 dots at the upper end of each block are always turned off (shown in black). Other dots are turned on or off in a pattern indicating their coordinate positions.

  FIG. 2 is a schematic diagram showing the configuration of one block in the coordinate pattern shown in FIG.

  In FIG. 2, when the display data corresponding to each dot is 1, the dot is in the off state, and when it is 0, the dot is in the on state. Accordingly, as shown in FIG. 2, the lighting and extinguishing patterns of the dot row for the top two rows, the dot row for the leftmost two rows, and the lowermost right dot are common to all the blocks. As a result, all the dots on the boundary line of each block are fixed in the light-off state, and as shown in FIG. 1, a grid-like image pattern in which the display area is divided for each block is displayed as the entire coordinate pattern. It will be. Note that the dots α2 and β2 shown in FIG. 2 are dots representing the coordinate reference in one block, so-called coordinate reference points.

  In each block, 15 dots other than the dots given the fixed display data as described above are used to display information indicating the relative position of the block in the entire coordinate pattern. The dots X0 to X7 shown in FIG. 2 represent the X coordinate position of the block depending on the lighting state / lighting state. The dots Y0 to Y6 represent the Y coordinate position of the block depending on the respective lighting state / extinguishing state.

Therefore, when acquiring the coordinate information from the coordinate pattern shown in FIG. 1, the light pen first turns off 6 dots continuously in the vertical direction based on the captured image signal obtained by capturing the coordinate pattern. The position of the block boundary dot row where the state continues and the extinguishing state for 6 dots continues in the horizontal direction is detected. At this time, if block boundary dot rows, that is, [β1, α1] to [β1, α6] dot rows and [β2, α1] to [β6, α1] dot rows in FIG. 2 can be detected, X0 to X0 shown in FIG. The positions of X7 and Y0 to Y6 dots can be specified. Therefore, the light pen always includes an area corresponding to nine blocks, that is, a vertical direction (6 dots × 3 times) × horizontal direction (an image signal corresponding to at least one block). An area of 6 dots × 3 times is simultaneously photographed. Then, the light pen extracts image patterns corresponding to X0 to X7 and Y0 to Y6 dots from the captured image signal based on the position of the block boundary dot row detected from the captured image signal. Get the coordinate position represented by the pattern.
Japanese Patent Laid-Open No. 2002-082763

  However, in the conventional coordinate position acquisition method from the coordinate pattern, in order to always include one block in the captured image signal, the captured image signal obtained by capturing an area 9 times that block is used. The signal processing as described above must be performed. Therefore, there is a problem that the processing time spent for reading the coordinate pattern is long.

  Therefore, the problems to be solved by the present invention include the above-mentioned drawbacks as an example, a two-dimensional coordinate pattern that can be read at high speed and with high accuracy, and a display device and reading device for the coordinate pattern. Is the purpose.

The coordinate pattern of the invention according to claim 1 is a two-dimensional coordinate pattern displayed on a display surface composed of a plurality of pixels arranged in a matrix in the row and column directions of the display panel, and the coordinate pattern is: A plurality of first diagonal pixel lines each consisting of a pixel column obliquely continuous with respect to the row and column directions at a predetermined interval; and each of the plurality of pixels is the plurality of pixels. A plurality of second diagonal pixel lines comprising pixel columns that are obliquely continuous with respect to the row and column directions at a predetermined interval in a direction intersecting the first diagonal pixel line; and the plurality of second pixels among the plurality of pixels. A plurality of pixel blocks surrounded by one oblique pixel line and the plurality of second oblique pixel lines and carrying two-dimensional coordinate data of the coordinate position, the plurality of first oblique pixel lines and the plurality of second blocks. Each pixel of the diagonal pixel line is in the same state of either one of the lit state and the unlit state so as to represent the range of each of the plurality of pixel blocks, and each of the plurality of pixel blocks is a two-dimensional image of the individual pixel block. Positional symmetry relationship among the rotation detection pixel portion that is turned on or off in a predetermined display pattern to detect the rotation angle at the time of coordinate data reading, and four regions divided into two regions substantially orthogonal to each other Each of the pixels belonging to one of the two regions is turned on or off according to the X coordinate data of the two-dimensional coordinate data, and the other two of the four regions that are in a position-symmetrical relationship. Each of the pixels belonging to the region includes an information display pixel portion that is turned on or off according to Y coordinate data of the two-dimensional coordinate data.

The coordinate pattern display device of the invention according to claim 8 is a display device for displaying a two-dimensional coordinate pattern on a display surface of a display panel composed of a plurality of pixels arranged in a matrix in the row and column directions, The coordinate pattern includes a plurality of first diagonal pixel lines each consisting of a pixel column obliquely continuous with respect to the row and column directions at a predetermined interval, and each of the plurality of pixels. A plurality of second diagonal pixel lines comprising pixel columns obliquely continuous with respect to the row and column directions at a predetermined interval in a direction intersecting the plurality of first diagonal pixel lines, A plurality of pixel blocks surrounded by the plurality of first oblique pixel lines and the plurality of second oblique pixel lines and carrying two-dimensional coordinate data at the position, and the plurality of first oblique pixel lines and The pixels in each of the plurality of second diagonal pixel lines are in the same state of either one of the lighting state and the non-lighting state so as to represent the range of each of the plurality of pixel blocks. Of the four regions divided into two regions that are substantially orthogonal to the rotation detection pixel portion that is turned on or off in a predetermined display pattern to detect the rotation angle when reading the two-dimensional coordinate data of the pixel block Each of the pixels belonging to one of the two regions that are in a symmetrical relationship is in a lighting state or a light-off state corresponding to the X coordinate data of the two-dimensional coordinate data, and the positional symmetry relationship in the four regions. Each of the pixels belonging to the other two regions is turned on or off according to the Y coordinate data of the two-dimensional coordinate data, and the display It is characterized by having a display drive means for displaying in the display plane of the coordinate pattern by driving the panel.

A coordinate pattern reading device according to a ninth aspect of the invention is a reading device for reading a coordinate pattern displayed on a display surface of a display panel composed of a plurality of pixels arranged in a matrix in the row and column directions, A plurality of first diagonal pixel lines each consisting of a pixel column obliquely continuous with respect to the row and column directions at a predetermined interval, and each of the plurality of pixels is a plurality of the first pixels. A plurality of second diagonal pixel lines comprising pixel columns obliquely continuous with respect to the row and column directions at a predetermined interval in a direction intersecting with one diagonal pixel line; and the plurality of first of the plurality of pixels. A plurality of pixel blocks surrounded by the diagonal pixel lines and the plurality of second diagonal pixel lines and carrying the two-dimensional coordinate data of the coordinate positions, and the plurality of first diagonal pixel lines and the plurality of the second pixel blocks. Each pixel of the diagonal pixel line is in the same state of either one of the lit state and the unlit state so as to represent the range of each of the plurality of pixel blocks, and each of the plurality of pixel blocks is a two-dimensional image of the individual pixel block. Positional symmetry relationship among the rotation detection pixel portion that is turned on or off in a predetermined display pattern to detect the rotation angle at the time of coordinate data reading, and four regions divided into two regions substantially orthogonal to each other Each of the pixels belonging to one of the two regions is turned on or off according to the X coordinate data of the two-dimensional coordinate data, and the other two of the four regions that are in a position-symmetrical relationship. Each of the pixels belonging to the region includes an information display pixel unit that is turned on or off according to the Y coordinate data of the two-dimensional coordinate data, and the plurality of first oblique images An image sensor that obtains a photographed image signal by photographing the display surface in a photographing range including at least one pixel at a position where the line and the plurality of second diagonal pixel lines intersect, and the intersection from the photographed image signal A reference pixel detecting means for detecting a pixel at a position to be used as a reference pixel, and a plurality of read pixels corresponding to the position where the reference pixel exists in the shooting range, and each of the read pixels indicated by the shot image signal Coordinate data detection means for detecting the X coordinate data and the Y coordinate data based on the lighting and extinction states of

  In the coordinate pattern of the invention according to claim 1, a plurality of pixel blocks surrounded by a plurality of first diagonal pixel lines and a plurality of second diagonal pixel lines carry two-dimensional coordinate data of the coordinate position, Each of the plurality of pixel blocks includes a rotation detection pixel unit and an information display pixel unit. In the information display pixel portion, each of the pixels belonging to one of the two regions having a symmetrical relationship among the four regions divided in two directions substantially orthogonal to each other corresponds to the X coordinate data of the two-dimensional coordinate data. Each of the pixels belonging to the other two regions having a symmetrical relationship among the four regions is turned on or turned off according to the Y coordinate data of the two-dimensional coordinate data. .

  In the coordinate pattern display device according to the eighth aspect of the invention, the display driving means displays the coordinate pattern on the display surface of the display panel. In the coordinate pattern, a plurality of pixel blocks surrounded by a plurality of first oblique pixel lines and a plurality of second oblique pixel lines carry two-dimensional coordinate data of the coordinate position, and each of the plurality of pixel blocks is The rotation detection pixel unit and the information display pixel unit are provided. In the information display pixel portion, each of the pixels belonging to one of the two regions having a symmetrical relationship among the four regions divided in two directions substantially orthogonal to each other corresponds to the X coordinate data of the two-dimensional coordinate data. Each of the pixels belonging to the other two regions having a symmetrical relationship among the four regions is turned on or turned off according to the Y coordinate data of the two-dimensional coordinate data. .

  In the coordinate pattern reading device according to the ninth aspect of the present invention, the coordinate pattern is displayed on the display surface of the display panel photographed by the image sensor, and the coordinate pattern includes a plurality of first diagonal pixel lines and a plurality of diagonal pixel lines. A plurality of pixel blocks surrounded by the second diagonal pixel line carry two-dimensional coordinate data of the coordinate position, and each of the plurality of pixel blocks includes a rotation detection pixel unit and an information display pixel unit. Yes. In the information display pixel portion, each of the pixels belonging to one of the two regions having a symmetrical relationship among the four regions divided in two directions substantially orthogonal to each other corresponds to the X coordinate data of the two-dimensional coordinate data. Each of the pixels belonging to the other two regions having a symmetrical relationship among the four regions is turned on or turned off according to the Y coordinate data of the two-dimensional coordinate data. . In the reading device, the display surface is photographed by the image sensor in a photographing range including at least one pixel at a position where the plurality of first oblique pixel lines and the plurality of second oblique pixel lines of the coordinate pattern intersect. A pixel at a crossing position is detected as a reference pixel from the captured image signal obtained from the sensor, and a plurality of read pixels are selected corresponding to the position of the reference pixel in the imaging range, and the pixel indicated by the captured image signal is selected. X-coordinate data and Y-coordinate data are detected based on the lighting and extinguishing states of each reading pixel.

  Therefore, according to the present invention, if the shooting range on the display surface is a relatively small range including pixels at the intersection of the first diagonal pixel line and the second diagonal pixel line, the shooting range on the display surface is The pixel position indicating the X-coordinate data and Y-coordinate data of the pixel block included in the imaging range can be determined regardless of the position of the movement, so the pixel block rotates with respect to the captured image signal from the angle of the rotation detection pixel unit. The X coordinate data and the Y coordinate data corresponding to the on / off state of the pixel to be read in the information display pixel portion after being corrected can be obtained quickly and accurately.

  FIG. 3 shows a configuration of an electronic blackboard to which the present invention is applied. In this electronic blackboard, the movement trajectory when the user moves the tip of an electronic chalk (described later) in contact with the screen of the plasma display panel is displayed on the display screen as it is.

  As shown in FIG. 3, the electronic blackboard includes a blackboard surface image data memory 1, an image superimposing circuit 2, an SF pixel drive data generation circuit 3, a drive control circuit 4, an address driver 5, a coordinate data memory 6, and a two-dimensional code conversion circuit. 7, a row electrode driver 8, an electronic choke 9, a receiving circuit 10, an image data generation circuit 11, and a plasma display panel 100.

The plasma display panel 100 (hereinafter referred to as PDP 100) is an electronic blackboard body, and includes a transparent front substrate (not shown) that bears the blackboard surface and a back substrate (not shown). A discharge space in which a discharge gas is enclosed exists between the front substrate and the rear substrate. A plurality of row electrodes each extending in the horizontal direction (lateral direction) of the display surface are formed on the front substrate. On the other hand, a plurality of column electrodes extending in the vertical direction (longitudinal direction) of the display surface are formed on the rear substrate. A pixel cell is formed at each of the intersections (including the discharge space) of the plurality of row electrodes and the plurality of column electrodes. As shown in FIG. 3, the pixel cell is composed of horizontal M × vertical N, and includes three types of pixel cell P _R that emits red light, pixel cell P _G that emits green light, and pixel cell P _B that emits blue light. Become.

  On the display surface of the PDP 100, a coordinate pattern is displayed in addition to a moving miracle of the electronic chalk 9 and an image corresponding to the external input image data. The coordinate pattern includes a plurality of pixel blocks PB and a plurality of first and second diagonal pixel lines. As shown in FIG. 4, each pixel block PB is composed of 41 pixels surrounded by a plurality of first diagonal pixel lines that are equally spaced at the lower left and a plurality of second oblique pixel lines that are equally spaced at the lower right. It is a block. The first and second oblique pixel lines are continuous lines formed by pixels adjacent to each other at the corners of the pixels. All the pixels forming the first and second diagonal pixel lines are turned on.

  Further, the pixel at the intersection of the first and second diagonal pixel lines becomes the reference pixel (a pixel including “•” in FIG. 4). Each pixel block PB is surrounded by four reference pixels, which are the upper and lower and left and right reference pixels for each pixel block PB. Each pixel block PB is used to display coordinate data indicating the XY coordinate position on the PDP 100.

  FIG. 5A shows one pixel block PB and first and second oblique pixel lines surrounding it. The pixel block PB has a rotation detection pixel portion, an X coordinate pixel portion, and a Y coordinate pixel portion. The X coordinate pixel portion and the Y coordinate pixel portion are information display pixel portions.

  The rotation detection pixel portion is arranged in a cross shape so as to be divided into left and right at the center in the pixel block PB, and is composed of nine pixels that are continuous in the vertical direction and two pixels that are adjacent to both sides of the center pixel. The pixels are turned on or turned off as shown in FIG. 5B to represent a predetermined display pattern.

  The X coordinate pixel portion and the Y coordinate pixel portion are a pixel group that expresses its own XY coordinate position on the display surface of the PDP 100 as a value, and two pixel blocks PB are provided. As shown in FIG. 5 (c), the X coordinate pixel portion is formed of 7 pixels in each of the lower left region and the upper right region divided into the left and right by the rotation detection pixel portion, and the coordinate value (X This is a state corresponding to the bits X1 to X7 (coordinate data) (lighted state or unlit state). As shown in FIG. 5 (d), the Y coordinate pixel portion is formed of 8 pixels in each of the upper left region and the lower right region divided into right and left by the rotation detection pixel portion, and the coordinate value in the Y axis direction based on the coordinate data ( This is a state corresponding to the bits Y1 to Y8 (Y coordinate data) (lighting state or light extinguishing state). In a pixel line in which three pixels of the rotation detection pixel unit are arranged in the horizontal direction in the pixel block, one pixel of the X coordinate pixel unit and one or two pixels of the Y coordinate pixel unit are mixed on both sides of the rotation detection pixel unit.

  As shown in FIG. 4, straight lines connecting the reference pixels at positions where the first and second oblique pixel lines intersect in the X direction (horizontal direction) and the Y direction (vertical direction) are X and Y scale lines. X coordinate pixel portions (pixels X1 to X7) within a range surrounded by two adjacent X scale lines indicate the same X coordinate position, and a Y coordinate pixel portion within a range surrounded by two adjacent Y scale lines (Pixels Y1 to Y8) indicate the same Y coordinate position. In FIG. 4, only the portions of the coordinate positions (x, y) to (x + 5, y + 3) are shown.

  In each pixel block PB, the coordinate data represented by the two X coordinate pixel units are different from each other depending on the coordinate position where the pixel block PB is located, and the coordinate data represented by the two Y coordinate pixel units is also different from each other. That is, even in the same pixel block, the X coordinate value indicated by the pixels X1 to X7 in the upper right region is one larger than that of the pixels X1 to X7 in the lower left region. Similarly, even in the same pixel block, the Y coordinate value indicated by the pixels Y1 to Y8 in the upper left area is one larger than that of the pixels Y1 to Y8 in the lower right area. For example, in the same pixel block PB, the coordinate data indicated by the X coordinate pixel portion in the lower left region indicates x, the coordinate data indicated by the X coordinate pixel portion in the upper right region indicates x + 1, and the Y coordinate pixel portion in the upper left region indicates The coordinate data to be represented represents y + 2, and the coordinate data represented by the Y coordinate pixel portion in the lower right region represents y + 3.

In the blackboard surface image data memory 1, blackboard surface image data representing a blackboard surface (for example, one black color) to be displayed on the entire screen of the PDP 100 is stored in advance. Blackboard surface image data memory 1 sequentially reads the blackboard surface image data, to the image superimposing circuit 2 so as blackboard surface image data D _BB.

Image superimposition circuit 2, the image shown a blackboard surface image shown in blackboard surface image data D _BB, and an image indicated by the external input image data signal D _IN, in the display image data signals D _TR (to be described later) Is generated for each pixel cell P and supplied to each of the SF pixel drive data generation circuit 3 and the drive control circuit 4. When the blackboard display cancellation signal is supplied from the drive control circuit 4 (described later), the image superimposing circuit 2 indicates the image indicated by the external input image data signal _DIN and the display image data signal _DTR . Pixel data PD indicating an image obtained by superimposing an image to be generated for each pixel cell P is supplied to each of the SF pixel drive data generation circuit 3 and the drive control circuit 4.

  For each pixel data PD, the SF pixel drive data generation circuit 3 changes the state of each pixel cell P in each of the subfields SF1 to SF8 (described later) according to the luminance level indicated by the pixel data PD. Pixel drive data GD1 to GD8 to be set to one state in the extinguishing mode are generated and supplied to the address driver 5.

  In the coordinate data memory 6, coordinate data indicating the coordinate position (X, Y) in the screen of the PDP 100 is stored in advance. For each pixel block PB, coordinate data indicating coordinate positions in the X direction (horizontal direction) and the Y direction (vertical direction) in the screen of the PDP 100 in the pixel block PB is associated and stored in the coordinate data memory 6. Yes. The coordinate data memory 6 reads out the coordinate data and supplies it to the two-dimensional code conversion circuit 7.

  The two-dimensional code conversion circuit 7 is associated with each pixel of the PDP 100, and pixel drive data GD0 indicating, for example, a logic level 1 for a pixel that is in a lighting state and a logic level 0 for a pixel that is in a light-off state. Is supplied to the address driver 5.

  The drive control circuit 4 performs a two-dimensional code display drive process and a main image display drive process within a display period of one frame (or one field) based on a light emission drive sequence as shown in FIG. 6 based on the subfield method. And are executed sequentially. In the main image display drive process, the drive control circuit 4 sequentially executes the address process W and the sustain process I in each of the eight subfields SF1 to SF8 as shown in FIG. The drive control circuit 4 executes the reset process R prior to the address process W only in the subfield SF1. In the two-dimensional code display drive process, the drive control circuit 4 sequentially executes the reset process R, the address process W, and the sustain process I in the subfield SF0 as shown in FIG. A blanking period BT having a predetermined period length is provided after the main image display driving process.

  The drive control circuit 4 generates various control signals for driving the PDP 100 as follows by executing the reset process R, the address process W, and the sustain process I, respectively, to the address driver 5 and the row electrode driver 8, respectively. Supply.

  In response to the execution of the reset process R, the row electrode driver 8 applies a reset pulse to initialize all pixel cells P of the PDP 100 to a lighting mode state to all the row electrodes of the PDP 100.

  Next, in response to execution of the address process W, the address driver 5 generates a pixel data pulse having a voltage corresponding to the pixel drive data GD corresponding to the subfield SF to which the address process W belongs. That is, for example, the address driver 5 generates a pixel data pulse corresponding to the pixel drive data GD1 in the address step W of the subfield SF1, and a pixel data pulse corresponding to the pixel drive data GD2 in the address step W of the subfield SF2. Is generated. At this time, for example, when pixel drive data GD indicating that the pixel cell P is set to the lighting mode state is supplied, the address driver 5 generates a high-voltage pixel data pulse, while in the extinction mode. When pixel drive data GD indicating that the state is set is supplied, a low-voltage pixel data pulse is generated.

  During this time, the row electrode driver 8 sequentially applies the scan pulse to each row electrode of the PDP 100 in synchronization with the application timing of the pixel data pulse group for each display line. With this operation, each pixel cell P for one display line belonging to the row electrode to which the scan pulse is applied is set to a state (lighting mode or light-off mode) corresponding to the pixel data pulse.

  Next, in response to the execution of the sustain process I, the row electrode driver 8 repeatedly discharges only the pixel cells P in the lighting mode state over the light emission period assigned to the subfield SF to which the sustain process I belongs. A sustain pulse to be emitted is applied to all the row electrodes of the PDP 100. In the embodiment shown in FIG. 6, the minimum number of sustain pulses in the minimum light emission period is assigned to the subfield SF0.

Here, according to the execution of the main image display driving process (subfields SF1 to SF8) as shown in FIG. 6, each pixel cell emits light with the luminance corresponding to the luminance level indicated by the pixel data PD. Therefore, according to the pixel data PD generated based on the blackboard surface image data D _BB representing the blackboard surface (e.g., black color), on the entire screen of the image PDP100 representing a such board surface shown in example FIGS. 7 (a) Is displayed.

  On the other hand, according to the execution of the two-dimensional code display driving process (subfield SF0) as shown in FIG. 6, according to the pixel driving data GD0 based on the coordinate data, each pixel cell P in the sustaining process I of the subfield SF0. Light is emitted. That is, the lighting and extinguishing pattern by the two-dimensional code indicating the coordinate position of the X coordinate pixel portion and the Y coordinate pixel portion of each pixel block PB as shown in FIG. 4 is the coordinate position of each pixel block PB as shown in FIG. Each is formed above.

  The light emission period assigned to the sustain process I of the subfield SF0 is set in a short period of time so that the lighting and extinguishing patterns based on the two-dimensional code cannot be seen. Further, immediately before the subfield SF0, there is a blanking period BT as shown in FIG. This eliminates the influence of afterglow in the subfield SF8 when the light emitted in the subfield SF0 is captured by the following electronic choke.

  The electronic choke 9 extracts lighting and extinguishing patterns based on the two-dimensional code from the photographed image signal obtained by photographing the display screen of the PDP 100 in a photographing range slightly wider than the pixel block PB. A coordinate signal indicating a coordinate position corresponding to the pattern is wirelessly transmitted.

  FIG. 8 is a diagram showing an example of the internal configuration of the electronic choke 9. The electronic choke 9 includes an objective lens 90, an image sensor 91, a noise sensor 92, a frame synchronization detection circuit 93, an image processing circuit 94, a writing pressure sensor 95, a coordinate information extraction circuit 96, and a wireless transmission circuit 98.

  The objective lens 90 condenses the display light irradiated from the display screen of the PDP 100 and irradiates it on the light receiving surface of the image sensor 91. FIG. 9 shows a pixel group in the reading range of the PDP 100, that is, the photographing range RM, by light reception on the light receiving surface of the image sensor 91. The shooting range RM corresponds to 98 pixels, and each of the pixels is assigned one of the pixel numbers 1 to 50, and the same number of pixels is always the same in the sustain process I of the subfield SF0. A pixel that is turned on / off is shown.

  The noise sensor 92 emits noise generated from the screen of the PDP 100 in accordance with the discharge generated in each pixel cell P of the PDP 100, that is, pulse-shaped noise that becomes a logic level 1 when detecting emission of infrared rays, ultraviolet rays, or electromagnetic waves. A detection signal NZ is generated and supplied to the frame synchronization detection circuit 93. Various discharges are generated during the execution period of the subfields SF0 to SF8 within the display period of one frame (or one field). Therefore, every time this discharge is generated, a pulse-like form having a logic level 1 as shown in FIG. A noise detection signal NZ is generated. Since no discharge is generated in the blanking period BT after the end of the subfield SF8, the noise detection signal NZ becomes a logic level 0 as shown in FIG. In response to the noise detection signal NZ, the frame synchronization detection circuit 93 is an image capture signal CV that becomes a logic level 1 only during the execution period of the sustain process I of the subfield SF0 shown in FIG. Is supplied to the image sensor 91.

  The image sensor 91 captures the display light received by the light receiving surface only while the image capture signal CV of logic level 1 as shown in FIG. 6 is supplied, and the image signal corresponding to the display light is captured image signal. This is supplied to the image processing circuit 94 as SG. That is, the image sensor 91 performs image processing on the photographic image signal SG corresponding to the turn-on / off pattern displayed by the execution of the two-dimensional code display driving process (subfield SF0), that is, the coordinate pattern representing the coordinate position of the pixel block PB. This is supplied to the circuit 94. The writing pressure sensor 95 provided at the tip of the electronic choke 9 generates a drawing execution signal indicating that drawing is being performed on the blackboard surface while the tip is pressed on the screen of the PDP 100. This is supplied to the image processing circuit 94. The image processing circuit 94 captures the captured image signal SG supplied from the image sensor 91 only while the drawing execution signal is supplied. The image processing circuit 94 samples only the signal level obtained for each pixel cell P from the photographed image signal SG, and supplies a data series based on the sample values to the coordinate information extraction circuit 96 as two-dimensional code data CDD. To do. Each sampling position is performed based on the first and second diagonal pixel lines represented by the captured image signal SG.

  By the sampling operation, the image processing circuit 94 generates two-dimensional code data CDD composed of coordinate data indicated by each of the X coordinate pixel portion and the Y coordinate pixel portion in the imaging range RM and supplies the two-dimensional code data CDD to the coordinate information extraction circuit 96. Further, when the luminance level indicated by the photographed image signal SG is biased to a luminance side higher than the predetermined luminance, the image processing circuit 94 determines that the external light is strong and outputs an offset signal that should be suppressed. The sensor 91 is supplied. At this time, the image sensor 91 performs contrast adjustment on the captured image signal SG according to the offset signal.

  The coordinate information extraction circuit 96 extracts coordinate position information on the display screen based on the two-dimensional code data CDD by performing a coordinate information extraction operation every predetermined period, and supplies this to the wireless transmission circuit 98 as coordinate data ZD. .

  In the coordinate information extraction operation, the coordinate information extraction circuit 96 determines whether an image based on the two-dimensional code data CDD has been acquired as shown in FIG. 10 (step S1). When it is determined in step S1 that an image based on the two-dimensional code data CDD has been acquired, the coordinate information extraction circuit 96 uses, for example, an inclination of the electronic choke 9 with respect to the acquired image based on the two-dimensional code data CDD. A distortion correction process for correcting the resulting trapezoidal distortion is performed (step S2). Next, the coordinate information extraction circuit 96 determines whether or not the first and second diagonal pixel lines exist in the acquired image subjected to the distortion correction process (step S3). When it is determined in step S3 that the first and second diagonal pixel lines are present, the coordinate information extraction circuit 96 determines that the rotation angle is 0, 90, 180, based on the first and second diagonal pixel lines. A rotation process to be rotated so as to be any one of 270 degrees is performed on the acquired image (step S4). Next, the coordinate information extraction circuit 96 determines whether or not the rotation detection pixel portion has been detected from the acquired image subjected to the rotation processing (step S5). If it is determined in step S5 that the rotation detection pixel portion has not been detected, or if it is determined in step S3 that the first and second diagonal pixel lines have not been detected, or image acquisition is performed in step S1. If it is determined that it has not been made, the coordinate information extraction circuit 96 executes a predetermined defect process (not described) (step S0). On the other hand, if it is determined in step S5 that the rotation detection pixel unit has been detected, the coordinate information extraction circuit 96 rotates based on the rotation detection pixel unit to rotate the acquired image at the correct angle (0 degrees). Correction processing is performed (step S6). Next, the coordinate information extraction circuit 96 detects a reference pixel position from each of the pixel positions where the first and second oblique pixel lines appear (step S7). The reference pixel position is a pixel position where the first and second diagonal pixel lines intersect each other.

  Next, the coordinate information extraction circuit 96 detects the pixel number in the imaging range RM corresponding to the pixels X1 to X7 of the X coordinate pixel portion to be read based on the detected reference pixel position number (step S8). The X coordinate values are determined by reading out the pixels X1 to X7 of the X coordinate pixel portion from the two-dimensional code data after the rotation correction according to the detected pixel number in the photographing range RM (step S9). Based on the detected reference pixel position number, the pixel number in the shooting range RM corresponding to the pixels Y1 to Y8 of the Y coordinate pixel portion to be read is detected (step S10), and the detected pixel number in the shooting range RM is set. Accordingly, the pixels Y1 to Y8 of the Y coordinate pixel portion are read from the two-dimensional code data after rotation correction, and the Y coordinate value is determined (step S11). Coordinate data ZD representing the X coordinate value and the Y coordinate value determined in steps S9 and S11 is supplied to the wireless transmission circuit 98 (step S12).

  The wireless transmission circuit 98 modulates the coordinate data ZD supplied from the coordinate information extraction circuit 96 and wirelessly transmits it.

The receiving circuit 10 shown in FIG. 3 receives the transmission wave from the electronic choke 9, demodulates it, restores the coordinate data ZD, and supplies it to the image data generation circuit 11. The image data generation circuit 11 generates image data representing a straight line or a curve that sequentially traces each of the coordinate positions indicated by the coordinate data ZD sequentially supplied from the reception circuit 10, and this is used as a display image data signal _DTR. This is supplied to the image superimposing circuit 2. Thus, such display image data signals D _TR in accordance with the pixel data PD obtained by superimposing on the blackboard surface image data D _BB, in the main-image display driving step consisting subfields SF1~SF8 as shown in FIG. 6 Followed drive is made. At this time, when the tip of the electronic choke 9 is brought into contact with the screen of the PDP 100 and the tip is moved, a straight line or curved image along the movement locus becomes the blackboard surface image data as shown in FIG. It is superimposed and displayed in the blackboard surface image shown in D _BB.

  Next, the pixel number detection operation in steps S8 and S10 will be specifically described. Step S8 is executed as shown in FIGS. 11 and 12, and similarly, step S10 is executed as shown in FIGS.

  In the pixel number detection operation of the X coordinate pixel portion in step S8, first, as shown in FIG. 11, the detection reference pixel position is any of the pixel numbers 1, 2, 6, 7, 11, 12, 16, and 17. (Step S21), there are four reference pixels in the shooting range RM. In this case, for example, as illustrated in FIG. 15, a pixel block surrounded by four reference pixels (that is, upper and lower and left and right reference pixels) is included in the imaging range RM. A pixel number in the imaging range RM corresponding to the position of one of the pixels X1 to X7 of the two X coordinate pixel portions (lower left region and upper right region) in the pixel block is detected (step S22). In FIG. 15, the detection reference pixel position is the pixel number 2, and the pixels X1 to X7 of the X coordinate pixel portion in the lower left area and the upper right area that can be read are shown.

  When the detection reference pixel position is any one of pixel numbers 3, 4, 10, 13, 14, 19, and 20 (step S23), there are two reference pixels in the imaging range RM. In this case, for example, as shown in FIG. 16, the pixel X <b> 1 of one of the two X coordinate pixel portions in the pixel block having the two reference pixels as the lower reference pixel and the right reference pixel. Pixel numbers in the imaging range RM corresponding to the positions of ~ X7 are detected (step S24). In FIG. 16, the detection reference pixel position is the pixel number 4, and pixels X1 to X7 of the X coordinate pixel portion in the lower left area and the upper right area that can be read are shown.

  When the detection reference pixel position is any one of the pixel numbers 5, 8, 9, 15, and 18 (step S25), there are two reference pixels in the imaging range RM. In this case, for example, as shown in FIG. 17, the pixel X <b> 1 of one of the two X coordinate pixel portions in the pixel block having the two reference pixels as the upper reference pixel and the left reference pixel. Pixel numbers in the imaging range RM corresponding to the positions of ~ X7 are detected (step S26). In FIG. 17, the detection reference pixel position is the pixel number 4, and the readable pixels X1 to X7 of the X coordinate pixel portion in the lower left area and the upper right area are shown.

  When the detection reference pixel position is one of the pixel numbers 21 and 22 (step S27), there are two reference pixels in the imaging range RM. In this case, an imaging range corresponding to the position of the pixel X1 to X7 of one of the two X coordinate pixel portions in the pixel block in which the two reference pixels are the upper reference pixel and the right reference pixel. A pixel number in the RM is detected (step S28).

  When the detection reference pixel position is one of the pixel numbers 23 and 24 (step S29), one reference pixel exists within the imaging range RM. In this case, the pixel number in the imaging range RM corresponding to the position of the pixel X1 to X7 of one of the two X coordinate pixel portions in the pixel block in which the one reference pixel is the right reference pixel. Is detected (step S30).

  When the detection reference pixel position is the pixel number 25 (step S31), one reference pixel exists within the imaging range RM. In this case, the pixel number in the imaging range RM corresponding to the position of the pixel X1 to X7 of one of the two X coordinate pixel portions in the pixel block having the one reference pixel as the upper reference pixel. Is detected (step S32).

  When the detection reference pixel position is any one of the pixel numbers 26, 27, 31, 32, 36, 37, 41, and 42 (step S33), there are two reference pixels in the imaging range RM. In this case, for example, as shown in FIG. 18, the X coordinate pixel portion in the upper right region in the pixel block having the two reference pixels as the upper reference pixel and the right reference pixel, and the two reference pixels. Pixel number in the imaging range RM corresponding to the position of the pixel X1 to X7 of any one of the X coordinate pixel portion in the lower left region in the pixel block having the pixel as the lower reference pixel and the left reference pixel Is detected (step S34). In FIG. 18, the detection reference pixel position is the pixel number 26, and the readable pixels X1 to X7 of the X coordinate pixel portion in the upper right region and the lower left region are shown.

  As shown in FIG. 12, when the detection reference pixel position is one of the pixel numbers 28 and 29 (step S35), one reference pixel exists within the imaging range RM. In this case, the X coordinate pixel portion in the upper right region in the pixel block having the one reference pixel as the upper reference pixel, and the lower left region in the pixel block having the one reference pixel as the left reference pixel. The pixel number in the imaging range RM corresponding to the position of the pixel X1 to X7 of any one of the X coordinate pixel portions is detected (step S36).

  When the detection reference pixel position is any one of the pixel numbers 30, 33, 34, 40, 43, and 44 (step S37), one reference pixel exists in the imaging range RM. In this case, the X coordinate pixel portion in the upper right area in the pixel block having the one reference pixel as the right reference pixel, and the lower left area in the pixel block having the one reference pixel as the lower reference pixel. The pixel number in the photographing range RM corresponding to the position of the pixel X1 to X7 of any one of the X coordinate pixel portions of the X coordinate pixel portion is detected (step S38).

  When the detection reference pixel position is any one of the pixel numbers 35, 38, 39, and 45 (step S39), one reference pixel exists within the imaging range RM. In this case, the X coordinate pixel portion in the upper right region in the pixel block having the one reference pixel as the upper reference pixel, and the lower left region in the pixel block having the one reference pixel as the left reference pixel. The pixel number in the imaging range RM corresponding to the position of the pixel X1 to X7 of any one of the X coordinate pixel portions is detected (step S40).

  When the detection reference pixel position is one of the pixel numbers 46 and 47 (step S41), there are two reference pixels in the imaging range RM. In this case, the imaging range corresponding to the position of the pixel X1 to X7 of one of the two X coordinate pixel portions in the pixel block in which the two reference pixels are the left reference pixel and the lower reference pixel. A pixel number in the RM is detected (step S42).

  When the detection reference pixel position is one of the pixel numbers 48 and 49 (step S43), one reference pixel exists within the imaging range RM. In this case, the pixel number in the imaging range RM corresponding to the position of the pixel X1 to X7 of one of the two X coordinate pixel portions in the pixel block having the one reference pixel as the left reference pixel. Is detected (step S44).

  When the detection reference pixel position is any one of the pixel numbers 50 (step S45), one reference pixel exists in the imaging range RM. In this case, the pixel number in the imaging range RM corresponding to the position of the pixel X1 to X7 of one of the two X coordinate pixel portions in the pixel block having the one reference pixel as the lower reference pixel. Is detected (step S46).

  In the pixel number detection operation of the Y coordinate pixel portion in step S10, first, as shown in FIG. 13, the detection reference pixel position is any of the pixel numbers 1, 2, 6, 7, 11, 12, 16, and 17. (Step S51), there are four reference pixels in the imaging range RM. In this case, for example, as shown in FIG. 19, a pixel block surrounded by four reference pixels (that is, upper and lower and left and right reference pixels) is included in the imaging range RM. The pixel number in the imaging range RM corresponding to the position of the pixels Y1 to Y8 of one of the two Y coordinate pixel portions (upper left area and lower right area) in the pixel block is detected (step S52). ). In FIG. 19, the detection reference pixel position is the pixel number 2, and the pixels Y1 to Y8 of the Y coordinate pixel portion in the upper left area and the lower right area that can be read are shown.

  When the detection reference pixel position is any one of pixel numbers 3, 4, 5, 8, 9, 10, 13, 14, 15, 18, 19, and 20 (step S53), it is within the imaging range RM. There are two reference pixels. In this case, for example, as shown in FIG. 20, the pixel Y1 of the pattern of either one of the two Y coordinate pixel portions in the pixel block having the two reference pixels as the lower reference pixel and the right reference pixel. Pixel numbers within the imaging range RM corresponding to the positions of ~ Y8 are detected (step S54). In FIG. 20, the detection reference pixel position is the pixel number 3, and pixels Y1 to Y8 of the Y coordinate pixel portion in the upper left area and the lower right area that can be read are shown.

  When the detection reference pixel position is one of the pixel numbers 21 and 22 (step S55), there are two reference pixels in the imaging range RM. In this case, the imaging range corresponding to the position of the pixels Y1 to Y8 of either one of the two Y coordinate pixel portions in the pixel block having the two reference pixels as the upper reference pixel and the right reference pixel. A pixel number in the RM is detected (step S56).

  When the detection reference pixel position is any one of the pixel numbers 23, 24, and 25 (step S57), one reference pixel exists in the shooting range RM. In this case, the Y coordinate pixel portion in the lower right region in the pixel block having the one reference pixel as the right reference pixel, and the upper left in the pixel block having the one reference pixel as the upper reference pixel. A pixel number in the imaging range RM corresponding to the position of the pixel Y1 to Y8 of any one of the patterns in the Y coordinate pixel portion of the region is detected (step S58).

  When the detection reference pixel position is one of the pixel numbers 26, 27, 31, and 32 (step S59), there are two reference pixels in the imaging range RM. In this case, for example, as shown in FIG. 21, the positions of the pixels Y1 to Y8 of the Y coordinate pixel portion in the lower right region in the pixel block having the two reference pixels as the upper reference pixel and the right reference pixel. A pixel number within the imaging range RM corresponding to is detected (step S60). FIG. 21 shows a case where the detection reference pixel position is the pixel number 26, and the pixels Y1 to Y8 of the Y coordinate pixel portion in the lower right area that can be read are shown.

  When the detection reference pixel position is the pixel number 28 (step S61), one reference pixel exists within the imaging range RM. In this case, the Y coordinate pixel portion in the lower right region in the pixel block having the one reference pixel as the right reference pixel, and the right in the pixel block having the one reference pixel as the upper reference pixel. A pixel number in the imaging range RM corresponding to the position of the pixel Y1 to Y8 of any one of the patterns in the Y coordinate pixel portion in the lower region is detected (step S62).

  When the detection reference pixel position is any one of the pixel numbers 29, 30, 33, 34, and 35 (step S63), one reference pixel exists in the imaging range RM. In this case, the pixel number in the imaging range RM corresponding to the position of the pixels Y1 to Y8 in the Y coordinate pixel portion in the lower right region in the pixel block having the one reference pixel as the right reference pixel is detected. (Step S64).

  As shown in FIG. 14, when the detection reference pixel position is any one of the pixel numbers 36, 37, 41, and 42 (step S65), there are two reference pixels in the imaging range RM. The pixel numbers in the imaging range RM corresponding to the positions of the pixels Y1 to Y8 in the Y coordinate pixel portion in the upper left area in the pixel block having the two reference pixels as the left reference pixel and the lower reference pixel are detected ( Step S66).

  When the detection reference pixel position is any one of the pixel numbers 38, 39, 40, 43, 44, and 45 (step S67), one reference pixel exists in the imaging range RM. In this case, the pixel number in the imaging range RM corresponding to the position of the pixels Y1 to Y8 in the Y coordinate pixel portion in the upper left area in the pixel block having the one reference pixel as the left reference pixel is detected ( Step S68).

  When the detection reference pixel position is one of the pixel numbers 46 and 47 (step S69), there are two reference pixels in the shooting range RM. In this case, the imaging range corresponding to the position of the pixels Y1 to Y8 of one of the two Y coordinate pixel portions in the pixel block having the two reference pixels as the left reference pixel and the lower reference pixel. A pixel number in the RM is detected (step S70).

  When the detection reference pixel position is the pixel number 48 (step S71), one reference pixel exists within the imaging range RM. In this case, two Y coordinate pixel portions in the pixel block having the one reference pixel as the left reference pixel, and a lower right region in the pixel block having the one reference pixel as the lower reference pixel. The pixel number in the imaging range RM corresponding to the position of any one pattern of the pixels Y1 to Y8 is detected (step S72).

  When the detection reference pixel positions are pixel numbers 49 and 50 (step S73), one reference pixel exists within the imaging range RM. In this case, the Y coordinate pixel portion in the upper left area in the pixel block having the one reference pixel as the left reference pixel, and the lower right in the pixel block having the one reference pixel as the lower reference pixel. A pixel number in the imaging range RM corresponding to the position of the pixel Y1 to Y8 of any one of the patterns in the Y coordinate pixel portion of the region is detected (step S74).

  In this way, pixel numbers in the imaging range RM corresponding to the X and Y coordinate pixel portions to be read are detected. Therefore, the values indicated by the pixels X1 to X7 of the X coordinate pixel portion and the pixels Y1 to Y8 of the Y coordinate pixel portion determined from the rotation-corrected two-dimensional code data are read, and the contact position of the electronic choke 9 on the display surface of the PDP 100 X and Y coordinate values can be reliably obtained.

  Note that the imaging range RM for reading the X coordinate pixel portion and the Y coordinate pixel portion of FIG. 9 may be a range of 98 pixels (each shown by a square) as shown in FIG. This is obtained by rotating the imaging range RM in FIG. 9 by 90 degrees.

  Regarding the pixel number detection operation in steps S8 and S10, in addition to the specific examples shown in FIGS. 11 to 14 described above, for example, the reference pixel position number and the imaging range RM for the X coordinate pixel portion to be read are included. This may be executed by using a data table indicating the relationship between each pixel number and each pixel number in the imaging range RM for the Y coordinate pixel portion. That is, when the reference pixel position number is detected in step S7, each pixel number of the X coordinate pixel portion and each pixel number of the Y coordinate pixel portion corresponding to the detected reference pixel position number is read from the data table. .

  In the coordinate pattern of the above-described embodiment, the horizontal direction on the display surface of the PDP 100 is the X-axis direction, and the vertical direction is the Y-axis direction, but the X-axis direction is the extension direction of the first diagonal pixel line, The Y-axis direction may be the extending direction of the second diagonal pixel line. FIG. 23 shows a coordinate pattern of an oblique orthogonal coordinate system in which the X-axis direction is the extension direction of the first oblique pixel line and the Y-axis direction is the extension direction of the second oblique pixel line. In the coordinate pattern, pixels X1 to X7 of the X coordinate pixel portion and pixels Y1 to Y8 of the Y coordinate pixel portion are arranged in each pixel block PB. The first diagonal pixel line forms an X scale line, and the second diagonal pixel line forms a Y scale line. Therefore, the X coordinate pixel portions (pixels X1 to X7) in the range surrounded by two adjacent first diagonal pixel lines indicate the same X coordinate position, and the range is surrounded by two adjacent first diagonal pixel lines. Among the Y coordinate pixel portions (pixels Y1 to Y8), the same Y coordinate position is indicated. The X coordinate values indicated by the two X coordinate pixel portions in each pixel block PB are equal to each other. Similarly, the Y coordinate values indicated by the two Y coordinate pixel portions are equal to each other.

  FIG. 24 shows an imaging range RM for reading the coordinate pattern of the oblique orthogonal coordinate system of FIG. 23 by the image sensor 91, and any pixel number from 1 to 50 is assigned to each pixel of the imaging range RM. ing.

  Even in the case of the coordinate pattern of the oblique orthogonal coordinate system, the coordinate information extraction circuit 96 performs the coordinate information extraction operation as shown in FIG. In this coordinate information extraction operation, the pixel number of the X coordinate pixel portion in step S8 is detected as shown in FIGS. 25 to 27, and similarly, the pixel number of the Y coordinate pixel portion in step S10 is shown in FIGS. Detected.

  In the pixel number detection operation of the X coordinate pixel portion, first, as shown in FIG. 25, when the detection reference pixel position is one of the pixel numbers 1 and 2 (step S81), for example, FIG. As shown in FIG. 5, the image corresponding to the position of the pixels X1 to X7 of one of the two X coordinate pixel portions (upper right region and lower left region) in the pixel block having the reference pixel as the right reference pixel. A pixel number within the range RM is detected (step S82). FIG. 31 shows pixels X1 to X7 of the X coordinate pixel portion in the upper right area and the lower left area that can be read when the detection reference pixel position is the pixel number 1.

  When the detected reference pixel position is pixel number 3 (step S83), two X coordinate pixel portions in the pixel block having the reference pixel as the right reference pixel, or the reference pixel as the upper reference pixel. Pixel numbers within the imaging range RM corresponding to the positions of the pixels X1 to X7 of the two X coordinate pixel portions in the pixel block are detected (step S84). In this case, since all the pixels of the two X coordinate pixel portions in the pixel block to be used as the right reference pixel are not within the imaging range RM, the two X coordinate pixel portions indicating the same X coordinate value are The X coordinate value indicated by each X coordinate pixel portion is determined by a combination of some pixels. The same applies to the two X coordinate pixel portions in the pixel block which is the upper reference pixel. The same applies to detection of pixel numbers corresponding to the positions of pixels X1 to X7 in steps S90, S96, and S104, which will be described later.

  When the detection reference pixel position is any one of the pixel numbers 4 and 5 (step S85), one of the two X coordinate pixel portions in the pixel block having the reference pixel as the upper reference pixel is selected. Pixel numbers within the imaging range RM corresponding to the positions of the pixels X1 to X7 of the pattern are detected (step S86).

  When the detection reference pixel position is any one of pixel numbers 6, 7, and 15 (step S87), the pixel in the X coordinate pixel portion in the upper right region in the pixel block having the reference pixel as the upper reference pixel. Pixel numbers in the photographing range RM corresponding to the positions X1 to X7 are detected (step S88).

  When the detection reference pixel position is any one of pixel numbers 8, 9, 13, and 14 (step S89), the X coordinate pixel portion in the upper right region in the pixel block having the reference pixel as the right reference pixel And the pixel number in the imaging range RM corresponding to the position of the pixels X1 to X7, which is a combination of a part of the X pixel part in the upper right area in the pixel block with the reference pixel as the upper reference pixel Is detected (step S90).

  When the detected reference pixel position is any one of the pixel numbers 10, 11, and 12 (step S91), the pixel in the X coordinate pixel portion in the upper right region in the pixel block having the reference pixel as the right reference pixel Pixel numbers in the imaging range RM corresponding to the positions X1 to X7 are detected (step S92).

  When the detection reference pixel position is one of the pixel numbers 16 and 17 (step S93), the X coordinate pixel portion in the lower left region in the pixel block having the reference pixel as the left reference pixel, and the reference The pixel number in the imaging range RM corresponding to the position of the pixel X1 to X7 of any one pattern with the X coordinate pixel portion in the upper right region in the pixel block having the pixel as the upper reference pixel is detected (step S94). ).

  As shown in FIG. 26, when the detection reference pixel position is any one of pixel numbers 18, 19, 23, 24, 28, 29, 33, 34, 48, and 49 (step S95), for example, As shown in FIG. 32, a part of the X coordinate pixel portion in the upper right area in the pixel block having the reference pixel as the right reference pixel, and the upper right area in the pixel block having the reference pixel as the upper reference pixel. The position of the pixels X1 to X7 formed by a combination with a part of the X coordinate pixel part, or a part of the X coordinate pixel part in the lower left region in the pixel block having the reference pixel as the left reference pixel, and the reference pixel A pixel number in the imaging range RM corresponding to the positions of the pixels X1 to X7, which is a combination with a part of the X coordinate pixel portion in the lower left region in the pixel block as the lower reference pixel, is detected (step S96). In FIG. 32, the detection reference pixel position is the pixel number 18, and the pixels X1 to X3 in the X coordinate pixel portion in the upper right region in the pixel block to be read as the right reference pixel, Pixels X4 to X7 in the X coordinate pixel portion in the upper right region in the pixel block to be processed, pixels X1 to X5 in the X coordinate pixel portion in the lower left region in the pixel block serving as the left reference pixel, and the pixel block serving as the lower reference pixel X6 and X7 of the X coordinate pixel portion in the lower left area of FIG.

  When the detection reference pixel position is any one of the pixel numbers 20, 21, 22, 30, 31, and 32 (step S97), the upper right region in the pixel block having the reference pixel as the right reference pixel is displayed. Pixels in the photographing range RM corresponding to the positions of the pixels X1 to X7 of any one of the X coordinate pixel portion and the X coordinate pixel portion in the lower left region in the pixel block having the reference pixel as the lower reference pixel A number is detected (step S98).

  When the detection reference pixel position is any one of the pixel numbers 25, 26, 27, and 35 (step S99), the X coordinate pixel portion of the lower left region in the pixel block having the reference pixel as the left reference pixel And the pixel number in the imaging range RM corresponding to the position of the pixel X1 to X7 of any one pattern of the X coordinate pixel portion in the upper right region in the pixel block having the reference pixel as the upper reference pixel is detected. (Step S100).

  When the detection reference pixel position is any one of the pixel numbers 36, 37, and 45 (step S101), the pixel of the X coordinate pixel portion in the lower left region in the pixel block having the reference pixel as the left reference pixel Pixel numbers in the imaging range RM corresponding to the positions X1 to X7 are detected (step S102).

  When the detection reference pixel position is any one of the pixel numbers 38, 39, 43, and 44 (step S103), the X coordinate pixel portion of the lower left region in the pixel block having the reference pixel as the left reference pixel And a pixel number in the imaging range RM corresponding to the position of the pixels X1 to X7, which is a combination of a part of the X pixel part of the lower left area in the pixel block with the reference pixel as the lower reference pixel Is detected (step S104).

  As shown in FIG. 27, when the detection reference pixel position is one of the pixel numbers 40, 41, and 42 (step S105), the lower left area in the pixel block having the reference pixel as the lower reference pixel. Pixel numbers in the imaging range RM corresponding to the positions of the pixels X1 to X7 in the X coordinate pixel portion are detected (step S106).

  If the detected reference pixel position is one of the pixel numbers 46 and 47 (step S107), one of the two X coordinate pixel portions in the pixel block having the reference pixel as the left reference pixel is selected. Pixel numbers within the imaging range RM corresponding to the positions of the pixels X1 to X7 of the pattern are detected (step S108).

  When the detection reference pixel position is the pixel number 50 (step S109), the pixel X1 to X7 of one of the two X coordinate pixel portions in the pixel block having the reference pixel as the lower reference pixel is selected. A pixel number in the imaging range RM corresponding to the position is detected (step S110).

  In the pixel number detection operation of the Y coordinate pixel portion, first, as shown in FIG. 28, when the detection reference pixel position is the pixel number 1 (step S121), for example, as shown in FIG. The imaging range corresponding to the position of the pixels Y1 to Y8 of one of the two Y coordinate pixel portions (upper left area and lower right area) in the pixel block having the reference pixel as the right reference pixel in the RM A pixel number in the RM is detected (step S122). In FIG. 33, pixels Y1 to Y8 of the X coordinate pixel portion in the lower right region and the upper left region which are readable when the detection reference pixel position is the pixel number 1 are shown.

  When the detected reference pixel position is any one of pixel numbers 2, 7, 8, 9, 10, 11, 12, 13, and 14 (step S123), the pixel having the reference pixel as the right reference pixel Pixel numbers in the imaging range RM corresponding to the positions of the pixels Y1 to Y8 of the Y coordinate pixel portion in the lower right region in the block are detected (step S124).

  When the detection reference pixel position is any one of the pixel numbers 3 and 4 (step S125), the Y coordinate pixel portion in the lower right region in the pixel block having the reference pixel as the right reference pixel, or the A pixel number in the imaging range RM corresponding to the positions of the pixels Y1 to Y8 in the Y coordinate pixel portion in the upper left area in the pixel block having the reference pixel as the upper reference pixel is detected (step S126).

  If the detection reference pixel position is pixel number 5 (step S127), shooting corresponding to the positions of the pixels Y1 to Y8 in the Y coordinate pixel portion of the upper left area in the pixel block having the reference pixel as the upper reference pixel is performed. A pixel number within the range RM is detected (step S128).

  When the detection reference pixel position is pixel number 6 (step S129), it corresponds to the positions of the pixels Y1 to Y8 of the Y coordinate pixel portion in the lower right region in the pixel block having the reference pixel as the right reference pixel. Pixel numbers within the imaging range RM are detected (step S130).

  When the detected reference pixel position is any one of the pixel numbers 15, 16, 17, 25, 27, and 35 (step S131), the upper left region in the pixel block having the reference pixel as the left reference pixel is displayed. An imaging range RM corresponding to the position of pixels Y1 to Y8, which is a combination of a part of the Y coordinate pixel part and a part of the Y coordinate pixel part in the upper left area in the pixel block having the reference pixel as the upper reference pixel. The pixel number is detected (step S132). In this case, all of the pixels in the Y coordinate pixel portion in the pixel block serving as the left reference pixel and the Y coordinate pixel portion in the upper left region in the pixel block serving as the upper reference pixel are all within the imaging range RM. Therefore, the Y coordinate value indicated by each Y coordinate pixel unit is determined by a combination of some of the two Y coordinate pixel units indicating the same Y coordinate value. The same applies to detection of pixel numbers corresponding to the positions of pixels Y1 to Y8 in steps S134, S136, S138, S140, and S142 described later.

  As shown in FIG. 29, when the detection reference pixel position is any one of the pixel numbers 18, 19, 23, 24, 28, 33, and 34 (step S133), for example, as shown in FIG. In the imaging range RM, a part of the Y coordinate pixel portion in the upper left area in the pixel block having the reference pixel as the left reference pixel, and the Y in the upper left area in the pixel block having the reference pixel as the upper reference pixel The position of the pixels Y1 to Y8 formed by a combination with a part of the coordinate pixel part, or a part of the Y coordinate pixel part in the lower right region in the pixel block having the reference pixel as the right reference pixel, and the reference pixel A pixel number in the imaging range RM corresponding to the position of the pixels Y1 to Y8, which is a combination with a part of the Y coordinate pixel portion in the lower right region in the pixel block as the lower reference pixel, is detected (step S134). . In FIG. 34, the detection reference pixel position is the pixel number 19, and the pixels Y1 to Y3 in the Y coordinate pixel portion in the upper left area in the pixel block to be read as the left reference pixel, Pixels Y4 to Y8 in the Y coordinate pixel portion in the upper left region in the pixel block to be processed, pixels Y1 to Y7 in the Y coordinate pixel portion in the lower right region in the pixel block serving as the right reference pixel, and pixel blocks serving as the lower reference pixel Y8 of the Y coordinate pixel portion in the lower right area is shown.

  When the detected reference pixel position is any one of the pixel numbers 20, 22, 30, 32, 40, and 42 (step S135), the lower right region in the pixel block having the reference pixel as the right reference pixel. Shooting corresponding to the positions of the pixels Y1 to Y8, which is a combination of a part of the Y coordinate pixel part and a part of the Y coordinate pixel part in the lower right region in the pixel block having the reference pixel as the lower reference pixel A pixel number within the range RM is detected (step S136).

  When the detection reference pixel position is the pixel number 21 (step S137), a combination of two Y coordinate pixel portions in the pixel block having the reference pixel as the right reference pixel, or the reference pixel as the lower reference pixel A pixel number in the imaging range RM corresponding to the positions of the pixels Y1 to Y8 formed by the combination of two Y coordinate pixel portions in the pixel block is detected (step S138).

  When the detection reference pixel position is the pixel number 26 (step S139), a combination of two Y coordinate pixel portions in the pixel block having the reference pixel as the left reference pixel, or the reference pixel as the upper reference pixel A pixel number in the imaging range RM corresponding to the positions of the pixels Y1 to Y8 formed by the combination of two Y coordinate pixel portions in the pixel block is detected (step S140).

  When the detection reference pixel position is the pixel number 31 (step S141), it corresponds to the positions of the pixels Y1 to Y8 that are combinations of two Y coordinate pixel portions in the pixel block having the reference pixel as the lower reference pixel. The pixel number within the captured range RM is detected (step S142).

  When the detection reference pixel position is any one of the pixel numbers 36, 37, 38, 39, 43, 44, 45, and 47 (step S143), the upper left in the pixel block having the reference pixel as the left reference pixel. Pixel numbers within the imaging range RM corresponding to the positions of the pixels Y1 to Y8 in the Y coordinate pixel portion of the region are detected (step S144).

  When the detected reference pixel position is the pixel number 41 (step S145), shooting corresponding to the positions of the pixels Y1 to Y8 in the Y coordinate pixel portion in the upper left area in the pixel block having the reference pixel as the lower reference pixel. A pixel number within the range RM is detected (step S146).

  As shown in FIG. 30, when the detection reference pixel position is the pixel number 46 (step S147), one of the two Y coordinate pixel portions in the pixel block having the reference pixel as the left reference pixel is displayed. Pixel numbers in the photographing range RM corresponding to the positions of the pixels Y1 to Y8 of the pattern are detected (step S148).

  When the detection reference pixel position is one of the pixel numbers 48 and 49 (step S149), the Y coordinate pixel portion in the upper left area in the pixel block having the reference pixel as the left reference pixel, or the reference A pixel number in the photographing range RM corresponding to the positions of the pixels Y1 to Y8 in the Y coordinate pixel portion in the lower right region in the pixel block having the pixel as a lower reference pixel is detected (step S150).

  When the detection reference pixel position is the pixel number 50 (step S151), it corresponds to the positions of the pixels Y1 to Y8 of the Y coordinate pixel portion in the lower right region in the pixel block having the reference pixel as the lower reference pixel. Pixel numbers within the shooting range RM are detected (step S152).

  In this way, pixel numbers in the imaging range RM corresponding to the X and Y coordinate pixel portions to be read are detected. Therefore, the values indicated by the pixels X1 to X7 of the X coordinate pixel portion and the pixels Y1 to Y8 of the Y coordinate pixel portion determined from the rotation-corrected two-dimensional code data are read, and the contact position of the electronic choke 9 on the display surface of the PDP 100 X and Y coordinate values can be reliably obtained.

  Note that the imaging range RM for reading the X coordinate pixel portion and the Y coordinate pixel portion of the oblique orthogonal coordinate system may be a range of 50 pixels (each shown by a square) as shown in FIG. This is obtained by rotating the imaging range RM in FIG. 24 by 90 degrees.

  FIG. 36 shows coordinate patterns displayed on the display surface of the PDP 100 as another embodiment of the present invention. In this coordinate pattern, similarly to the coordinate pattern of FIG. 4 described above, the X direction is the horizontal direction, the Y direction is the vertical direction, and the plurality of pixel blocks PB and the plurality of first and second pixels. And diagonal pixel lines. In the coordinate pattern, an X coordinate pixel portion (pixels X1 to X7) indicating an X coordinate is provided in each of the upper right region and the lower left region of each pixel block PB, and each of the upper left region and the lower right region of each pixel block PB. Are provided with a Y coordinate pixel portion (pixels Y1 to Y7) indicating the Y coordinate. Each pixel block PB is surrounded by four reference pixels, which are the upper and lower and left and right reference pixels for each pixel block PB. The pixel block PB has a rotation detection pixel unit similar to the coordinate pattern of FIG. 4 in addition to the X coordinate pixel unit and the Y coordinate pixel unit.

  In the coordinate pattern of FIG. 36, the pixel adjacent to the left of the reference pixel is used as a display for separating the XY coordinates. When the coordinate delimiter pixel is in an extinguished state (mesh pixel in FIG. 36), adjacent reference pixels are delimited in the X coordinate and not delimited in the Y coordinate. On the other hand, when in the lighting state (hatched pixels in FIG. 36), adjacent reference pixels are not separated by the X coordinate and separated by the Y coordinate. Therefore, in the case of the coordinate pattern of FIG. 36, the straight line connecting the reference pixels in the vertical direction of the left adjacent coordinate delimiter pixel is the X scale line, and the reference pixel in which the left adjacent coordinate delimiter pixel is lit A straight line connecting the two in the horizontal direction is the Y scale line. X coordinate pixel portions (pixels X1 to X7) within a range surrounded by two adjacent X scale lines indicate the same X coordinate position, and a Y coordinate pixel portion within a range surrounded by two adjacent Y scale lines (Pixels Y1 to Y7) indicate the same Y coordinate position. In FIG. 36, only the coordinate positions (x-1, y-1) to (x + 2, y + 1) are shown.

  In this embodiment, the reference pixel for the X coordinate break is referred to as the X coordinate reference pixel, and the reference pixel for the Y coordinate break is referred to as the Y coordinate reference pixel.

  FIG. 37 shows an imaging range RM for reading the coordinate pattern of FIG. 36 by the image sensor 91, and any pixel number from 1 to 82 is assigned to each pixel of the imaging range RM. Pixel numbers 1, 2, 6 to 9, 13 to 16, 20 to 23, 27, and 28 are used redundantly, and pixels having the same number are in the same lighting or extinguishing state.

  Also in the case of the coordinate pattern of FIG. 36, the coordinate information extraction circuit 96 performs the coordinate information extraction operation as shown in FIG. In this coordinate information extraction operation, the pixel number of the X coordinate pixel portion in step S8 is detected as shown in FIGS. 38 and 39, and similarly, the pixel number of the Y coordinate pixel portion in step S10 is as shown in FIGS. Detected.

  In the pixel number detection operation of the X coordinate pixel portion, first, as shown in FIG. 38, it is determined whether or not there is a coordinate-delimited pixel in an unlit state within the imaging range RM (step S161). Since at least one reference pixel always exists within the imaging range RM, the extinction / lighting state of the pixel adjacent to the left of each reference pixel is determined. First, a description will be given of the case where there is a coordinate-delimited pixel in the extinguished state in the imaging range RM, that is, the case where the detection reference pixel position in step S7 is the X-coordinate reference pixel position that becomes the X-coordinate break.

  When the X coordinate reference pixel position is any one of pixel numbers 1, 2, 13, 14, 15, 16, 27, and 28 (step S162), two X coordinate reference pixels are within the imaging range RM. Exists. In this case, the positions of the pixels X1 to X7 of any one of the two X coordinate pixel portions (lower left region and upper right region) in the pixel block having the X coordinate reference pixel as the right and left reference pixels. A pixel number within the imaging range RM corresponding to is detected (step S163).

  When the X coordinate reference pixel position is any one of the pixel numbers 3, 4, 12, 17, 18, 26, 29, 30, and 31 (step S164), one X coordinate reference is included in the imaging range RM. Pixel exists. In this case, the pixel number in the imaging range RM corresponding to the position of the pixel X1 to X7 of one of the two X coordinate pixel portions in the pixel block having the X coordinate reference pixel as the right reference pixel. Is detected (step S165).

  When the X coordinate reference pixel position is any one of the pixel numbers 5, 19, 24, 25, 33, 34, and 35 (step S166), one X coordinate reference pixel exists in the imaging range RM. . In this case, the pixel number in the imaging range RM corresponding to the position of the pixel X1 to X7 of one of the two X coordinate pixel portions in the pixel block having the X coordinate reference pixel as the upper reference pixel. Is detected (step S167).

  When the X coordinate reference pixel position is any one of the pixel numbers 6, 7, 8, 9, 10, 11, 20, 21, 22, and 23 (step S168), the X coordinate is within the imaging range RM. There are two X-coordinate reference pixels that serve as delimiters. In this case, within the imaging range RM corresponding to the position of the pixel X1 to X7 of one of the two X coordinate pixel portions in the pixel block having the X coordinate reference pixel as the upper and lower reference pixels. A pixel number is detected (step S169).

  When the X coordinate reference pixel position is any one of the pixel numbers 36 to 39, 47 to 53, 61 to 67 (step S170), one X coordinate reference pixel exists in the imaging range RM. In this case, the X coordinate pixel portion in the lower left region in the pixel block having the X coordinate reference pixel as the left reference pixel, or the X coordinate in the upper right region in the pixel block having the X coordinate reference pixel as the upper reference pixel. Pixel numbers within the imaging range RM corresponding to the positions of the pixels X1 to X7 in the coordinate pixel portion are detected (step S171).

  When the X coordinate reference pixel position is any one of the pixel numbers 40 to 46, 54 to 60, 69, and 70 (step S172), one X coordinate reference pixel exists in the imaging range RM. In this case, the X coordinate pixel portion in the upper right area in the pixel block having the X coordinate reference pixel as the right reference pixel, or the X in the lower left area in the pixel block having the X coordinate reference pixel as the lower reference pixel. Pixel numbers within the imaging range RM corresponding to the positions of the pixels X1 to X7 in the coordinate pixel portion are detected (step S173).

  When the X coordinate reference pixel position is any one of the pixel numbers 71, 72, 76, 77, 78, and 82 (step S174), for example, as shown in FIG. There is an X coordinate reference pixel. In this case, the pixel number in the imaging range RM corresponding to the position of the pixel X1 to X7 of one of the two X coordinate pixel portions in the pixel block having the X coordinate reference pixel as the lower reference pixel. Is detected (step S175). In FIG. 43, the reference pixel position is the pixel number 71, and the pixels X1 to X7 of the X coordinate pixel portion in the upper right region and the lower left region in the pixel block to be read as the lower reference pixel are shown. Yes.

  As shown in FIG. 39, when the X coordinate reference pixel position is any one of the pixel numbers 73, 74, 75, 79, 80, and 81 (step S176), one X coordinate is within the imaging range RM. A reference pixel exists. In this case, the pixel number in the imaging range RM corresponding to the position of the pixel X1 to X7 of one of the two X coordinate pixel portions in the pixel block having the X coordinate reference pixel as the left reference pixel. Is detected (step S177).

  Next, a description will be given of a case where the result of determination in step S161 is that there are no extinguished coordinate segmentation pixels in the imaging range RM, that is, only the illuminated coordinate segmentation pixels exist in the imaging range RM. In this case, the detection reference pixel position in step S7 is a Y coordinate reference pixel position that becomes a break of the Y coordinate, and the Y coordinate reference pixel is a pixel number 31 to 33 in the imaging range RM as shown in FIG. The position is any one of positions 38 to 40, 45 to 47, 52 to 54, 59 to 61, and 66 to 68. The range of pixel numbers shown here is a predetermined range in the shooting range RM.

  In the case where the Y coordinate reference pixel position that becomes the break of the Y coordinate is any one of the pixel numbers 31, 32, 40, 45, 46, 54, 59, 60, and 68 (step S178), for example, FIG. As shown in FIG. 5, there is one Y coordinate reference pixel that is not a delimiter of the X coordinate in the imaging range RM. In this case, the X coordinate pixel portion in the upper right area in the pixel block having the Y coordinate reference pixel as the right reference pixel, or the X in the lower left area in the pixel block having the Y coordinate reference pixel as the lower reference pixel. Pixel numbers in the imaging range RM corresponding to the positions of the pixels X1 to X7 in the coordinate pixel portion are detected (step S179). In FIG. 45, the reference pixel position is the pixel number 31, and the pixels X1 to X7 in the X coordinate pixel portion in the upper right region in the pixel block to be read as the right reference pixel and the lower reference pixel are used. Pixels X1 to X7 in the X coordinate pixel portion in the lower left region in the pixel block are shown.

  When the Y coordinate reference pixel position is any one of the pixel numbers 33, 38, 39, 47, 52, 53, 61, 66, and 67 (step S180), the X coordinate delimiter is included in the imaging range RM. There is one Y coordinate reference pixel that is not. In this case, the X coordinate pixel portion in the lower left region in the pixel block having the Y coordinate reference pixel as the left reference pixel, or the X coordinate in the upper right region in the pixel block having the Y coordinate reference pixel as the upper reference pixel. Pixel numbers within the imaging range RM corresponding to the positions of the pixels X1 to X7 in the coordinate pixel portion are detected (step S181).

  In the pixel number detection operation of the Y coordinate pixel portion, first, as shown in FIG. 40, it is determined whether or not there is a coordinate-delimited pixel in an unlit state within the imaging range RM (step S191). First, a case will be described where there are coordinate-delimited pixels that are turned off in the imaging range RM.

  When the X coordinate reference pixel position is any one of pixel numbers 1, 2, 13, 14, 15, 16, 27, and 28 (step S192), there are two X coordinate reference pixels. In this case, the pixels Y1 to Y7 of any one of the two Y coordinate pixel portions (upper left region and lower right region) in the pixel block having the X coordinate reference pixel as the right and left reference pixels. A pixel number in the imaging range RM corresponding to the position is detected (step S193).

  When the X coordinate reference pixel position is any one of the pixel numbers 3, 29, 30, 31, and 42 (step S194), one X coordinate reference pixel position and one Y coordinate reference are within the imaging range RM. Pixels. In this case, the pixels in the imaging range RM corresponding to the positions of the pixels Y1 to Y7 of one of the two Y coordinate pixel portions in the pixel block having the X coordinate reference pixel position as the right reference pixel. A number is detected (step S195).

  When the X coordinate reference pixel position is any one of pixel numbers 4, 5, 10, 11, 12, 17, 18, 19, 24, 25, 26, 32, 33, 34, 39, 40, 41 (Step S196), one X coordinate reference pixel position exists within the imaging range RM. In this case, the Y coordinate pixel portion in the lower right region in the pixel block having the X coordinate reference pixel position as the right reference pixel, or the upper left region in the pixel block having the X coordinate reference pixel as the upper reference pixel Pixel numbers in the imaging range RM corresponding to the positions of the pixels Y1 to Y7 in the Y coordinate pixel portion are detected (step S197).

  When the X coordinate reference pixel position is any one of pixel numbers 6, 7, 8, 20, 21, 22, and 23 (step S198), there are two X coordinate reference pixel positions within the imaging range RM. To do. In this case, within the imaging range RM corresponding to the position of the pixels Y1 to Y7 of one of the two Y coordinate pixel portions in the pixel block having the X coordinate reference pixel as the upper and lower reference pixels. A pixel number is detected (step S199).

  When the X coordinate reference pixel position is any one of the pixel numbers 35, 36, 37, and 38 (step S200), one X coordinate reference pixel position exists within the imaging range RM. In this case, the pixel number in the imaging range RM corresponding to the position of the pixels Y1 to Y7 of either one of the two Y coordinate pixel portions in the pixel block having the X coordinate reference pixel as the upper reference pixel. Is detected (step S201).

  When the X coordinate reference pixel position is any one of the pixel numbers 43, 44, 45, 46, and 47 (step S202), one X coordinate reference pixel position exists within the imaging range RM. In this case, the pixel number in the imaging range RM corresponding to the positions of the pixels Y1 to Y7 in the Y coordinate pixel portion in the lower right region in the pixel block having the X coordinate reference pixel as the right reference pixel is detected. (Step S203).

  When the X coordinate reference pixel position is one of the pixel numbers 48 and 49 (step S204), one X coordinate reference pixel position exists within the imaging range RM. In this case, the pixel number in the imaging range RM corresponding to the positions of the pixels Y1 to Y7 in the Y coordinate pixel portion in the lower right region in the pixel block having the X coordinate reference pixel as the upper reference pixel is detected. (Step S205).

  When the X coordinate reference pixel position is any one of the pixel numbers 50, 51, 52, 53, and 54 (step S206), one X coordinate reference pixel position exists within the imaging range RM. In this case, the pixel number in the imaging range RM corresponding to the positions of the pixels Y1 to Y7 in the Y coordinate pixel portion in the upper left area in the pixel block having the X coordinate reference pixel as the left reference pixel is detected ( Step S207).

  When the X coordinate reference pixel position is one of the pixel numbers 55 and 56 (step S208), one X coordinate reference pixel position exists within the imaging range RM. In this case, the pixel number in the imaging range RM corresponding to the position of the pixels Y1 to Y7 of the Y coordinate pixel portion in the upper left area in the pixel block having the X coordinate reference pixel as the lower reference pixel is detected ( Step S209).

  When the X coordinate reference pixel position is any one of the pixel numbers 57, 58, 59, 69, 70, and 71 (step S210), one X coordinate reference pixel position exists in the imaging range RM. In this case, the pixel number in the imaging range RM corresponding to the position of the pixels Y1 to Y7 of one of the two Y coordinate pixel portions in the pixel block having the X coordinate reference pixel as the lower reference pixel. Is detected (step S211).

  When the X coordinate reference pixel position is any one of the pixel numbers 60 to 62, 67, 68, 72 to 82 (step S212), one X coordinate reference pixel position exists within the imaging range RM. . In this case, the Y coordinate pixel portion in the lower right region in the pixel block having the X coordinate reference pixel as the lower reference pixel, or the upper left region in the pixel block having the X coordinate reference pixel as the left reference pixel. Pixel numbers in the imaging range RM corresponding to the positions of the pixels Y1 to Y7 in the Y coordinate pixel portion are detected (step S213).

  When the X coordinate reference pixel position is any one of the pixel numbers 63, 64, 65, and 66 (step S214), one X coordinate reference pixel position exists within the imaging range RM. In this case, the pixel number in the imaging range RM corresponding to the position of the pixels Y1 to Y7 of one of the two Y coordinate pixel portions in the pixel block having the X coordinate reference pixel as the left reference pixel. Is detected (step S215).

  Next, a description will be given of a case where the result of determination in step S191 is that there are no extinguished coordinate segmentation pixels in the imaging range RM, that is, only the illuminated coordinate segmentation pixels exist in the imaging range RM. In this case, as shown in FIG. 44, the Y coordinate reference pixel on the right side of the lit-up coordinate delimiter pixel has pixel numbers 31 to 33, 38 to 40, 45 to 47, 52 to within the imaging range RM. 54, 59 to 61, and 66 to 68.

  When the Y coordinate reference pixel position is any one of the pixel numbers 31, 32, 33, 39, and 40 (step S216), one Y coordinate reference pixel exists in the imaging range RM. In this case, the Y coordinate pixel portion in the lower right region in the pixel block having the Y coordinate reference pixel as the right reference pixel, or the upper left region in the pixel block having the Y coordinate reference pixel as the upper reference pixel. Pixel numbers in the imaging range RM corresponding to the positions of the pixels Y1 to Y7 in the Y coordinate pixel portion are detected (step S217).

  When the Y coordinate reference pixel position is any one of the pixel numbers 45, 46, and 47 (step S218), one Y coordinate reference pixel exists within the imaging range RM. In this case, the pixel number in the imaging range RM corresponding to the positions of the pixels Y1 to Y7 in the Y coordinate pixel portion in the lower right region in the pixel block having the Y coordinate reference pixel as the right reference pixel is detected. (Step S219).

  When the Y coordinate reference pixel position is any one of the pixel numbers 52, 53, and 54 (step S220), one Y coordinate reference pixel exists within the imaging range RM. In this case, the pixel number in the imaging range RM corresponding to the positions of the pixels Y1 to Y7 in the Y coordinate pixel portion in the upper left region in the pixel block having the Y coordinate reference pixel as the left reference pixel is detected ( Step S221).

  When the Y coordinate reference pixel position is any one of the pixel numbers 59, 60, 61, 66, 67, and 68 (step S222), one Y coordinate reference pixel exists in the imaging range RM. In this case, the Y coordinate pixel portion in the upper left area in the pixel block having the Y coordinate reference pixel as the left reference pixel, or the lower right area in the pixel block having the Y coordinate reference pixel as the lower reference pixel. Pixel numbers within the imaging range RM corresponding to the positions of the pixels Y1 to Y7 in the Y coordinate pixel portion are detected (step S223).

  In this way, it is determined whether the reference pixel is the X or Y coordinate reference pixel according to the extinction state or lighting state of the coordinate separation pixel adjacent to the left of the reference pixel, and X to be read according to the determination result. And the pixel number within the imaging range RM corresponding to the Y coordinate pixel portion is detected. Therefore, the position indicated by each of the pixels X1 to X7 of the X coordinate pixel portion and the pixels Y1 to Y7 of the Y coordinate pixel portion determined from the rotation-corrected two-dimensional code data is read, and the contact position of the electronic choke 9 on the display surface of the PDP 100 X and Y coordinate values can be reliably obtained.

  Note that the imaging range RM for reading the X coordinate pixel portion and the Y coordinate pixel portion in the coordinate pattern of FIG. 36 may be a range of 98 pixels (each indicated by a square) as shown in FIG.

  In the pixel number detection operation of the X coordinate pixel section shown in FIG. 38 and FIG. 39 described above, the pixel number at the X coordinate reference pixel position is determined for the pixel number at the X coordinate reference pixel position when there is an extinguished coordinate segmentation pixel in the shooting range RM. All the numbers 1 to 82 in the RM are determined, and when only the coordinate delimited pixels that are lit exist in the shooting range RM, the pixel numbers of the Y coordinate reference pixel position are 31 to 33 and 38 in the shooting range RM. Although only ˜40, 45 to 47, 52 to 54, 59 to 61, and 66 to 68 are determined, this may be reversed. That is, when there is a coordinate segmentation pixel that is turned off in the imaging range RM, 1 to 82 is determined for the pixel number of the Y coordinate reference pixel position, and the pixels X1 to X1 of the X coordinate pixel unit are determined according to the Y coordinate reference pixel. When the pixel number corresponding to X7 is detected, and only the coordinate delimiter pixels that are lit exist in the imaging range RM, the pixel numbers of the X coordinate reference pixel positions are 31 to 33, 38 to 40, 45 to 47, 52. Only 54 to 59, 59 to 61, 66 to 68 are determined, and pixel numbers corresponding to the pixels Y1 to Y7 of the Y coordinate pixel portion are detected according to the X coordinate reference pixel. The same applies to the pixel number detection operation of the Y coordinate pixel unit shown in FIGS.

  In the coordinate pattern of FIG. 36, the pixel located right next to the reference pixel (the pixel located on the leftmost side) in each pixel block has no particular information, but for example, XY depending on the lighting / light-off state. It can be used to change the coordinate scale unit (unit for each X coordinate reference pixel, unit for each Y coordinate reference pixel) such as 1 and 2 times.

  Further, the coordinate delimiter pixels provided in the coordinate pattern of FIG. 36 are applied to an XY coordinate system such as the coordinate pattern of FIG. 4, but are applied to an oblique XY coordinate system such as the coordinate pattern of FIG. You can also.

  FIG. 46 further shows coordinate patterns displayed on the display surface of the PDP 100 as another embodiment of the present invention. In this coordinate pattern, similarly to the coordinate pattern of FIG. 4 described above, the X direction is the horizontal direction, the Y direction is the vertical direction, and the plurality of pixel blocks PB and the plurality of first and second pixels. And diagonal pixel lines. In the coordinate pattern, an X coordinate pixel portion (pixels X1 to X7) indicating an X coordinate is provided in each of the upper right region and the lower left region of each pixel block PB, and each of the upper left region and the lower right region of each pixel block PB. Are provided with a Y coordinate pixel portion (pixels Y1 to Y7) indicating the Y coordinate. Each pixel block PB is surrounded by four reference pixels, which are the upper and lower and left and right reference pixels for each pixel block PB. The pixel block PB has a rotation detection pixel unit similar to the coordinate pattern of FIG. 4 in addition to the X coordinate pixel unit and the Y coordinate pixel unit.

  In the coordinate pattern of FIG. 46, the pixel adjacent to the left of the reference pixel is used to display the arrangement of the X and Y coordinate pixel portions in the pixel block. That is, the XY arrangement display pixel is the rightmost pixel in the pixel block to which the pixel belongs. When the XY arrangement display pixel is in a light-off state (mesh pixel in FIG. 46), the X coordinate pixel unit is arranged in the upper left region and the lower right region in the pixel block, and the Y coordinate pixel unit is in the upper right region in the pixel block. Located in the lower left area. On the other hand, when in the lighting state (hatched pixels in FIG. 46), the X coordinate pixel portion is disposed in the upper right region and the lower left region in the pixel block, and the Y coordinate pixel portion is disposed in the upper left region and the lower right region in the pixel block. Be placed.

  In the case of the coordinate pattern of FIG. 46, a straight line connecting the reference pixels in the vertical direction of the XY arrangement display pixel adjacent to the left is the X scale line, and a straight line connecting the reference pixels in the horizontal direction is the Y scale line. Become. X coordinate pixel portions (pixels X1 to X7) within a range surrounded by two adjacent X scale lines indicate the same X coordinate position, and a Y coordinate pixel portion within a range surrounded by two adjacent Y scale lines (Pixels Y1 to Y7) indicate the same Y coordinate position. In FIG. 46, only the coordinate positions (x-1, y-1) to (x + 2, y + 1) are shown. As described above, the reference pixel in which the XY arrangement display pixel on the left side is in the off state is a coordinate reference pixel. On the other hand, the reference pixel in which the XY arrangement display pixel adjacent to the left is in a lit state is a non-coordinate reference pixel, and only forms a reference pixel for an adjacent pixel block.

  As the imaging range RM for reading the coordinate pattern of FIG. 46 by the image sensor 91, a range as shown in FIG. 24 can be used. That is, the imaging range RM with pixel numbers 1 to 50 attached thereto.

  Also in the case of the coordinate pattern of FIG. 46, the coordinate information extraction circuit 96 performs the coordinate information extraction operation as shown in FIG. In this coordinate information extraction operation, the pixel number of the X coordinate pixel portion in step S8 is detected as shown in FIGS. 47 to 50, and similarly, the pixel number of the Y coordinate pixel portion in step S10 is shown in FIGS. Detected.

  In the pixel number detection operation of the X coordinate pixel portion, first, as shown in FIG. 47, it is determined whether or not there is an XY-arranged display pixel in the extinguished state within the imaging range RM (step S231). Since there is one reference pixel in the imaging range RM, the extinction / lighting state of the XY arrangement display pixel adjacent to the left of the reference pixel is determined. First, a case will be described in which there are XY arrangement display pixels that are turned off in the imaging range RM. As described above, the reference pixel on the left side of the XY arrangement display pixel in the off state is the coordinate reference pixel.

  When the coordinate reference pixel position is any one of the pixel numbers 1 and 11 (step S232), the X coordinate pixels in the upper left area and the lower right area in the pixel block having the coordinate reference pixel as the right reference pixel. A pixel number in the imaging range RM corresponding to the position of the pixel X1 to X7 of any one of the patterns is detected (step S233).

  When the coordinate reference pixel position is any one of pixel numbers 2, 3, 4, 8, 9, 10, 12, 13, and 14 (step S234), the coordinate reference pixel is set as the right reference pixel. A pixel number in the imaging range RM corresponding to the positions of the pixels X1 to X7 in the X coordinate pixel portion in the lower right region in the pixel block is detected (step S235).

  If the coordinate reference pixel position is pixel number 5 (step S236), the pattern of either the upper right region or the lower left region of the X coordinate pixel portion in the pixel block having the coordinate reference pixel as the upper reference pixel is displayed. Pixel numbers within the imaging range RM corresponding to the positions of the pixels X1 to X7 are detected (step S237).

  When the coordinate reference pixel position is any one of the pixel numbers 6, 7, 15, 16, 17, 25, 26, and 27 (step S238), a pixel block having the coordinate reference pixel as the upper reference pixel. A pixel number in the imaging range RM corresponding to the positions of the pixels X1 to X7 in the X coordinate pixel portion in the upper right area is detected (step S239).

  If the coordinate reference pixel position is any one of pixel numbers 18, 19, 23, and 29 (step S240), the X coordinate of the lower right region in the pixel block having the coordinate reference pixel as the right reference pixel Within the imaging range RM corresponding to the position of the pixels X1 to X7, which is a combination of a part of the pixel part and a part of the X coordinate pixel part in the lower left region in the pixel block having the coordinate reference pixel as the lower reference pixel Are detected (step S241).

  When the coordinate reference pixel position is any one of the pixel numbers 20, 21, 22, 30, 31, 32, 40, 41, and 42 (step S242), the coordinate reference pixel is set as the lower reference pixel. A pixel number in the imaging range RM corresponding to the positions of the pixels X1 to X7 in the X coordinate pixel portion in the lower left region in the pixel block is detected (step S243).

  As shown in FIG. 48, when the coordinate reference pixel position is any one of the pixel numbers 24, 28, 33, 34, and 35 (step S244), the pixel having the coordinate reference pixel as the left reference pixel. Pixels X1 to X7 that are a combination of a part of the X coordinate pixel part in the upper left area in the block and a part of the X coordinate pixel part in the upper right area in the pixel block having the coordinate reference pixel as the upper reference pixel. A pixel number in the imaging range RM corresponding to the position is detected (step S245).

  When the coordinate reference pixel position is one of the pixel numbers 36 and 46 (step S246), the X coordinate pixels in the upper left area and the lower right area in the pixel block having the coordinate reference pixel as the left reference pixel. A pixel number in the imaging range RM corresponding to the position of the pixel X1 to X7 of any one of the patterns is detected (step S247).

  When the coordinate reference pixel position is any one of the pixel numbers 37, 38, 39, 43, 44, 45, 47, 48, and 49 (step S248), the coordinate reference pixel is set as the left reference pixel. A pixel number in the imaging range RM corresponding to the positions of the pixels X1 to X7 in the X coordinate pixel portion in the upper left area in the pixel block is detected (step S249).

  When the coordinate reference pixel position is the pixel number 50 (step S250), either one of the X coordinate pixel portions of the lower left region and the upper right region in the pixel block having the coordinate reference pixel as the lower reference pixel is used. Pixel numbers within the imaging range RM corresponding to the positions of the pixels X1 to X7 are detected (step S251).

  Next, a case will be described in which it is determined in step S231 that there is no XY arrangement display pixel that is turned off in the photographing range RM, that is, a case where there is an XY arrangement display pixel that is lit. As described above, the reference pixel on the left side of the XY arrangement display pixel that is lit is a non-coordinate reference pixel.

  As shown in FIG. 49, when the non-coordinate reference pixel position is pixel number 1 (step S252), the X coordinates of the upper right region and the lower left region in the pixel block having the non-coordinate reference pixel as the right reference pixel. A pixel number in the imaging range RM corresponding to the position of the pixel X1 to X7 of any one pattern of the pixel portion is detected (step S253).

  When the non-coordinate reference pixel position is any one of pixel numbers 2, 10, 11, and 12 (step S254), the X in the upper right area in the pixel block having the non-coordinate reference pixel as the right reference pixel. Pixel numbers in the imaging range RM corresponding to the positions of the pixels X1 to X7 in the coordinate pixel portion are detected (step S255).

  When the non-coordinate reference pixel position is any one of pixel numbers 3, 4, 5, 7, 8, 9, 13, 14, and 15 (step S256), the non-coordinate reference pixel is set as the upper reference pixel. A pixel number in the imaging range RM corresponding to the positions of the pixels X1 to X7 in the X coordinate pixel portion in the upper left area in the pixel block is detected (step S257).

  If the non-coordinate reference pixel position is pixel number 6 (step S258), one of the X coordinate pixel portions of the upper left area and lower right area in the pixel block having the non-coordinate reference pixel as the upper reference pixel. Pixel numbers in the imaging range RM corresponding to the positions of the pixels X1 to X7 of the pattern are detected (step S259).

  When the non-coordinate reference pixel position is one of the pixel numbers 16 and 17 (step S260), the X coordinate pixel portion of the lower left region in the pixel block having the non-coordinate reference pixel as the left reference pixel is set. Pixel numbers within the imaging range RM corresponding to the positions of the pixels X1 to X7 are detected (step S261).

  When the non-coordinate reference pixel position is any one of pixel numbers 18, 19, 23, and 29 (step S262), X in the upper right region in the pixel block having the non-coordinate reference pixel as the right reference pixel An imaging range corresponding to the positions of the pixels X1 to X7 formed by a combination of a part of the coordinate pixel part and a part of the X coordinate pixel part in the upper left region in the pixel block having the non-coordinate reference pixel as the upper reference pixel. A pixel number in the RM is detected (step S263).

  When the non-coordinate reference pixel position is any one of pixel numbers 20, 21, 22, 30, 31, and 32 (step S264), the non-coordinate reference pixel position in the pixel block having the non-coordinate reference pixel as the right reference pixel is set. Pixel numbers within the imaging range RM corresponding to the positions of the pixels X1 to X7 in the X coordinate pixel portion in the upper right region are detected (step S265).

  As shown in FIG. 50, when the non-coordinate reference pixel position is any one of the pixel numbers 24, 28, and 34 (step S266), in the pixel block having the non-coordinate reference pixel as the left reference pixel. Of pixels X1 to X7, each of which is a combination of a part of the X coordinate pixel portion in the lower left region and a part of the X coordinate pixel portion in the lower right region in the pixel block having the non-coordinate reference pixel as the lower reference pixel. A pixel number in the imaging range RM corresponding to the position is detected (step S267).

  When the non-coordinate reference pixel position is any one of the pixel numbers 25, 26, 27, 35, 36, 37, and 45 (step S268), the pixel block having the non-coordinate reference pixel as the left reference pixel. A pixel number in the imaging range RM corresponding to the positions of the pixels X1 to X7 in the X coordinate pixel portion in the lower left region is detected (step S269).

  When the non-coordinate reference pixel position is any one of the pixel numbers 38, 39, 40, 42, 43, 44, 48, 49, and 50 (step S270), the non-coordinate reference pixel is set as the lower reference pixel. A pixel number in the imaging range RM corresponding to the position of the pixels X1 to X7 in the X coordinate pixel portion in the lower right region in the pixel block is detected (step S271).

  When the non-coordinate reference pixel position is the pixel number 41 (step S272), one of the X coordinate pixel portions of the lower right region and the upper left region in the pixel block having the non-coordinate reference pixel as the lower reference pixel. Pixel numbers in the imaging range RM corresponding to the positions of the pixels X1 to X7 of the pattern are detected (step S273).

  When the non-coordinate reference pixel position is one of the pixel numbers 46 and 47 (step S274), the X coordinate pixel portions in the upper right region and the lower left region in the pixel block having the non-coordinate reference pixel as the left reference pixel. The pixel number in the imaging range RM corresponding to the position of the pixel X1 to X7 of any one of the patterns is detected (step S275).

  In the pixel number detection operation of the Y coordinate pixel portion, first, as shown in FIG. 51, it is determined whether or not there is an XY-arranged display pixel in the extinguished state within the imaging range RM (step S281). First, a case will be described in which there are XY arrangement display pixels that are turned off in the imaging range RM. The reference pixel on the left side of the XY arrangement display pixel in the off state is a coordinate reference pixel.

  If the coordinate reference pixel position is pixel number 1 (step S282), the pattern of either the upper right region or the lower left region of the Y coordinate pixel portion in the pixel block having the coordinate reference pixel as the right reference pixel Pixel numbers within the imaging range RM corresponding to the positions of the pixels Y1 to Y7 are detected (step S283).

  If the coordinate reference pixel position is any one of pixel numbers 2, 10, 11, and 12 (step S284), the Y coordinate pixel in the upper right region in the pixel block having the coordinate reference pixel as the right reference pixel. Pixel numbers in the photographing range RM corresponding to the positions of the pixels Y1 to Y7 of the part are detected (step S285).

  If the coordinate reference pixel position is any one of pixel numbers 3, 4, 5, 7, 8, and 9 (step S286), the upper left area in the pixel block having the coordinate reference pixel as the upper reference pixel. Pixel numbers in the imaging range RM corresponding to the positions of the pixels Y1 to Y7 in the Y coordinate pixel portion are detected (step S287).

  When the coordinate reference pixel position is the pixel number 6 (step S288), one of the Y coordinate pixel portions of the upper left area and the lower right area in the pixel block having the coordinate reference pixel as the upper reference pixel. Pixel numbers in the imaging range RM corresponding to the positions of the pixels Y1 to Y7 are detected (step S289).

  When the coordinate reference pixel position is any one of the pixel numbers 13, 14, 15, 18, 24, and 34 (step S290), the lower left region in the pixel block having the coordinate reference pixel as the left reference pixel. Shooting corresponding to the positions of pixels Y1 to Y7, which is a combination of a part of the Y coordinate pixel part of the pixel and a part of the Y coordinate pixel part of the upper left region in the pixel block having the coordinate reference pixel as the upper reference pixel A pixel number within the range RM is detected (step S291).

  When the coordinate reference pixel position is any one of the pixel numbers 16, 17, 25, 26, 27, 35, 36, 37, 45, and 47 (step S292), the coordinate reference pixel is set to the left reference pixel. A pixel number in the shooting range RM corresponding to the positions of the pixels Y1 to Y7 in the Y coordinate pixel portion in the lower left region in the pixel block is detected (step S293).

  As shown in FIG. 52, when the coordinate reference pixel position is any one of pixel numbers 20, 21, 22, 30, 31, and 32 (step S294), the coordinate reference pixel is set as the right reference pixel. A pixel number in the imaging range RM corresponding to the positions of the pixels Y1 to Y7 in the Y coordinate pixel portion in the upper right region in the pixel block to be detected is detected (step S295).

  When the coordinate reference pixel position is any one of the pixel numbers 19, 23, and 28 (step S296), the Y coordinate pixel portion of the lower left region in the pixel block having the coordinate reference pixel as the left reference pixel is used. Positions of pixels Y1 to Y7 that are a combination of a part and a part of the Y coordinate pixel portion in the upper left area in the pixel block having the coordinate reference pixel as the upper reference pixel, or the coordinate reference pixel as the right reference Composed of a combination of a part of the Y coordinate pixel part in the upper right area in the pixel block to be a pixel and a part of the Y coordinate pixel part in the lower right area in the pixel block having the coordinate reference pixel as the lower reference pixel Pixel numbers within the imaging range RM corresponding to the positions of the pixels Y1 to Y7 are detected (step S297).

  When the coordinate reference pixel position is any one of the pixel numbers 29, 33, 38, 39, and 40 (step S298), Y in the upper right area in the pixel block having the coordinate reference pixel as the right reference pixel. An imaging range corresponding to the positions of pixels Y1 to Y7 formed of a combination of a part of the coordinate pixel part and a part of the Y coordinate pixel part in the lower right region in the pixel block having the coordinate reference pixel as the lower reference pixel. A pixel number in the RM is detected (step S299).

  When the coordinate reference pixel position is the pixel number 41 (step S300), one of the Y coordinate pixel portions of the upper left region and the lower right region in the pixel block having the coordinate reference pixel as the lower reference pixel. Pixel numbers in the imaging range RM corresponding to the positions of the pixels Y1 to Y7 are detected (step S301).

  When the coordinate reference pixel position is any one of the pixel numbers 42, 43, 44, 48, 49, and 50 (step S302), the lower right corner in the pixel block having the coordinate reference pixel as the lower reference pixel. Pixel numbers within the imaging range RM corresponding to the positions of the pixels Y1 to Y7 in the Y coordinate pixel portion of the region are detected (step S303).

  When the coordinate reference pixel position is the pixel number 46 (step S304), the pattern of one of the lower left region and the upper right region of the Y coordinate pixel portion in the pixel block having the coordinate reference pixel as the left reference pixel. Pixel numbers within the imaging range RM corresponding to the positions of the pixels Y1 to Y7 are detected (step S305).

  Next, a case will be described in which it is determined in step S281 that there is no XY arrangement display pixel that is turned off in the imaging range RM, that is, there is an XY arrangement display pixel that is lit. The reference pixel on the left side of the XY arrangement display pixel that is lit is a non-coordinate reference pixel.

  As shown in FIG. 53, when the non-coordinate reference pixel position is pixel number 1 (step S306), Y in the upper left area and lower right area in the pixel block having the non-coordinate reference pixel as the right reference pixel. Pixel numbers in the imaging range RM corresponding to the positions of the pixels Y1 to Y7 of any one pattern of the coordinate pixel portion are detected (step S307).

  If the non-coordinate reference pixel position is any one of pixel numbers 2, 3, and 4 (step S308), the Y coordinate of the lower right region in the pixel block having the non-coordinate reference pixel as the right reference pixel Pixel numbers within the imaging range RM corresponding to the positions of the pixels Y1 to Y7 in the pixel portion are detected (step S309).

  When the non-coordinate reference pixel position is the pixel number 5 (step S310), one of the Y coordinate pixel portions in the upper right region and the lower left region in the pixel block having the non-coordinate reference pixel as the upper reference pixel. Pixel numbers within the imaging range RM corresponding to the positions of the pixels Y1 to Y7 of the pattern are detected (step S311).

  When the non-coordinate reference pixel position is the pixel number 6, 15, 16, 25, 26, 35 (step S312), the Y coordinate of the upper right region in the pixel block having the non-coordinate reference pixel as the upper reference pixel. Pixel numbers in the imaging range RM corresponding to the positions of the pixels Y1 to Y7 in the pixel portion are detected (step S313).

  When the non-coordinate reference pixel position is any one of pixel numbers 7, 17, 18, 24, and 27 (step S314), the upper right region in the pixel block having the non-coordinate reference pixel as the upper reference pixel. Corresponds to the positions of pixels Y1 to Y7 that are a combination of a part of the Y coordinate pixel part and a part of the Y coordinate pixel part in the lower right region in the pixel block whose non-coordinate reference pixel is the right reference pixel. The pixel number within the captured range RM is detected (step S315).

  When the non-coordinate reference pixel position is the pixel number 8, 9, 10, 11, 12, 13, 14 (step S316), the lower right area in the pixel block having the non-coordinate reference pixel as the right reference pixel. Pixel numbers in the photographing range RM corresponding to the positions of the pixels Y1 to Y7 in the Y coordinate pixel portion are detected (step S317).

  When the non-coordinate reference pixel position is any one of the pixel numbers 19, 23, 28, and 34 (step S318), the lower-right region in the pixel block having the non-coordinate reference pixel as the upper reference pixel. Positions of pixels Y1 to Y7 formed by a combination of a part of the Y coordinate pixel part and a part of the Y coordinate pixel part in the lower right region in the pixel block whose non-coordinate reference pixel is the right reference pixel, or A part of the Y coordinate pixel portion in the lower left region in the pixel block having the non-coordinate reference pixel as the lower reference pixel, and the Y coordinate pixel portion in the upper left region in the pixel block having the non-coordinate reference pixel as the left reference pixel Pixel numbers in the imaging range RM corresponding to the positions of the pixels Y1 to Y7 that are a combination with a part of the image are detected (step S319).

  As shown in FIG. 54, when the non-coordinate reference pixel position is the pixel number 20, 21, 30, 31 (step S320), the lower left area in the pixel block having the non-coordinate reference pixel as the lower reference pixel. Pixel numbers in the imaging range RM corresponding to the positions of the pixels Y1 to Y7 in the Y coordinate pixel portion are detected (step S321).

  When the non-coordinate reference pixel position is any one of the pixel numbers 22, 29, 32, 33, and 42 (step S322), the lower left region in the pixel block having the non-coordinate reference pixel as the lower reference pixel. Corresponding to the positions of the pixels Y1 to Y7, which are a combination of a part of the Y coordinate pixel part and a part of the Y coordinate pixel part in the upper left area in the pixel block having the non-coordinate reference pixel as the left reference pixel. Pixel numbers within the shooting range RM are detected (step S323).

  When the non-coordinate reference pixel position is the pixel number 36, 37, 38, 39, 43, 44, 45, 47, 48, 49 (step S324), the pixel having the non-coordinate reference pixel as the left reference pixel Pixel numbers in the imaging range RM corresponding to the positions of the pixels Y1 to Y7 of the Y coordinate pixel portion in the upper left area in the block are detected (step S325).

  When the non-coordinate reference pixel positions are pixel numbers 40 and 41 (step S326), the pixels Y1 to Y7 of the Y coordinate pixel portion in the lower left region in the pixel block having the non-coordinate reference pixel as the lower reference pixel are set. A pixel number in the imaging range RM corresponding to the position is detected (step S327).

  When the non-coordinate reference pixel position is the pixel number 46 (step S328), one of the Y coordinate pixel portions of the upper left area and the lower right area in the pixel block having the non-coordinate reference pixel as the left reference pixel. Pixel numbers in the imaging range RM corresponding to the positions of the pixels Y1 to Y7 of the pattern are detected (step S329).

  When the non-coordinate reference pixel position is the pixel number 50 (step S330), one of the Y coordinate pixel portions in the lower left region and the upper right region in the pixel block having the non-coordinate reference pixel as the lower reference pixel. Pixel numbers within the imaging range RM corresponding to the positions of the pixels Y1 to Y7 of the pattern are detected (step S331).

  In this way, it is determined whether the reference pixel is a coordinate reference pixel or a non-coordinate reference pixel according to the extinction state or the lighting state of the XY arrangement display pixel located on the left side of the reference pixel in the imaging range RM, A pixel number in the photographing range RM corresponding to the X and Y coordinate pixel portions to be read is detected according to the determination result. Therefore, the position indicated by each of the pixels X1 to X7 of the X coordinate pixel portion and the pixels Y1 to Y7 of the Y coordinate pixel portion determined from the rotation-corrected two-dimensional code data is read, and the contact position of the electronic choke 9 on the display surface of the PDP 100 X and Y coordinate values can be reliably obtained.

  The imaging range RM for reading the X coordinate pixel portion and the Y coordinate pixel portion in the coordinate pattern of FIG. 46 may be a range of 50 pixels (each indicated by a square) as shown in FIG.

  In the coordinate pattern of FIG. 46, the pixel located right next to the reference pixel in each pixel block (the pixel located on the leftmost side) does not have any information. It can be used to change the coordinate scale unit (unit for each X coordinate reference pixel, unit for each Y coordinate reference pixel) such as 1 and 2 times.

  Further, the XY arrangement display pixels provided in the coordinate pattern of FIG. 46 are applied to an XY coordinate system such as the coordinate pattern of FIG. 4, but are applied to an oblique XY coordinate system such as the coordinate pattern of FIG. You can also

It is a figure which shows the display form of the conventional coordinate pixel part. It is a schematic diagram which shows the structure of one block in the coordinate pixel part shown in FIG. It is a figure which shows schematic structure of the electronic blackboard to which this invention was applied. It is a figure which shows a part of coordinate pattern displayed on PDP shown by FIG. FIG. 5 is a diagram illustrating a first pixel line, a second pixel line, a pixel block, and a rotation detection pixel portion, an X coordinate pixel portion, and a Y coordinate pixel portion in the pixel block that constitute the coordinate pattern of FIG. 4. It is a figure which shows an example of the light emission drive sequence at the time of driving PDP. It is a figure which shows an example of the blackboard image displayed on PDP. It is a figure which shows the internal structure of the electronic chalk shown by FIG. It is a figure which shows an example of imaging | photography range RM by an electronic chalk. It is a flowchart which shows the coordinate information extraction operation | movement performed by the coordinate information extraction circuit in an electronic chalk. 11 is a flowchart specifically illustrating a pixel number detection operation of an X coordinate pixel unit during the coordinate information extraction operation of FIG. 10. 12 is a flowchart showing a continued part of the pixel number detection operation of FIG. 11. 11 is a flowchart specifically illustrating a pixel number detection operation of a Y coordinate pixel unit during the coordinate information extraction operation of FIG. 10. It is a flowchart which shows the continuation part of the pixel number detection operation | movement of FIG. FIG. 5 is a diagram showing each pixel position of a read X coordinate pixel portion when the pixel number of the reference pixel position within the imaging range RM is 2 for the coordinate pattern of FIG. 4. FIG. 5 is a diagram illustrating each pixel position of a read X coordinate pixel unit when the pixel number of the reference pixel position within the imaging range RM is 4 for the coordinate pattern of FIG. 4. FIG. 5 is a diagram showing each pixel position of a read X coordinate pixel portion when the pixel number of the reference pixel position within the imaging range RM is 5 for the coordinate pattern of FIG. 4. FIG. 5 is a diagram illustrating each pixel position of a read X-coordinate pixel portion when the pixel number of a reference pixel position within the imaging range RM is 26 for the coordinate pattern of FIG. 4. FIG. 5 is a diagram showing each pixel position of a read Y coordinate pixel portion when the pixel number of the reference pixel position within the imaging range RM is 2 for the coordinate pattern of FIG. 4. FIG. 5 is a diagram showing each pixel position of a read Y coordinate pixel portion when the pixel number of the reference pixel position within the imaging range RM is 3 for the coordinate pattern of FIG. 4. FIG. 5 is a diagram illustrating each pixel position of a read Y coordinate pixel portion when the pixel number of a reference pixel position within the imaging range RM is 26 for the coordinate pattern of FIG. 4. It is a figure which shows the other example of imaging | photography range RM by an electronic chalk. It is a figure which shows a part of coordinate pattern displayed on PDP shown by FIG. 3 as another Example of this invention. It is a figure which shows an example of the imaging | photography range RM used for the coordinate pattern of FIG. It is a flowchart which shows concretely pixel number detection operation | movement of the X coordinate pixel part about the coordinate pattern of FIG. FIG. 26 is a flowchart showing a continued portion of the pixel number detection operation of FIG. 25. FIG. It is a flowchart which shows the continuation part of the pixel number detection operation | movement of FIG. It is a flowchart which shows concretely the pixel number detection operation | movement of the Y coordinate pixel part about the coordinate pattern of FIG. FIG. 29 is a flowchart showing a continued portion of the pixel number detection operation of FIG. 28. FIG. 30 is a flowchart showing a continued portion of the pixel number detection operation of FIG. 29. It is a figure which shows each pixel position of the reading X coordinate pixel part in case the pixel number of the reference | standard pixel position within the imaging | photography range RM is 1 about the coordinate pattern of FIG. It is a figure which shows each pixel position of the reading X coordinate pixel part in case the pixel number of the reference | standard pixel position in the imaging | photography range RM is 18 about the coordinate pattern of FIG. It is a figure which shows each pixel position of the reading Y coordinate pixel part in case the pixel number of the reference | standard pixel position in the imaging | photography range RM is 1 about the coordinate pattern of FIG. It is a figure which shows each pixel position of the reading Y coordinate pixel part in case the pixel number of the reference | standard pixel position in the imaging | photography range RM is 19 about the coordinate pattern of FIG. It is a figure which shows the other example of the imaging | photography range RM used for the coordinate pattern of FIG. It is a figure which shows a part of coordinate pattern displayed on PDP shown by FIG. 3 as another Example of this invention. It is a figure which shows an example of the imaging | photography range RM used for the coordinate pattern of FIG. FIG. 37 is a flowchart specifically illustrating a pixel number detection operation of an X coordinate pixel unit for the coordinate pattern of FIG. 36. FIG. 39 is a flowchart showing a continued part of the pixel number detection operation of FIG. 38. FIG. FIG. 37 is a flowchart specifically illustrating a pixel number detection operation of a Y coordinate pixel unit for the coordinate pattern of FIG. 36. 41 is a flowchart showing a continued portion of the pixel number detection operation of FIG. 40. It is a flowchart which shows the continuation part of the pixel number detection operation | movement of FIG. FIG. 37 is a diagram illustrating each pixel position of a read X coordinate pixel portion when the pixel number of a reference pixel position within the imaging range RM is 71 for the coordinate pattern of FIG. 36. It is a figure which shows the predetermined range of imaging | photography range RM. FIG. 37 is a diagram showing each pixel position of a read Y coordinate pixel portion when the pixel number of the reference pixel position within the imaging range RM is 31 for the coordinate pattern of FIG. 36. It is a figure which shows a part of coordinate pattern displayed on PDP shown by FIG. 3 as another Example of this invention. 47 is a flowchart specifically illustrating a pixel number detection operation of an X coordinate pixel unit for the coordinate pattern of FIG. 46. 48 is a flowchart showing a continued part of the pixel number detection operation of FIG. 47. 48 is a flowchart showing another continued portion of the pixel number detection operation of FIG. 47. 50 is a flowchart showing a further continued portion of the pixel number detection operation of FIG. 49. 47 is a flowchart specifically illustrating a pixel number detection operation of a Y coordinate pixel unit for the coordinate pattern of FIG. 46. 52 is a flowchart showing a continued portion of the pixel number detection operation of FIG. 51. 52 is a flowchart showing another continued portion of the pixel number detection operation of FIG. 51. 54 is a flowchart showing a further continued portion of the pixel number detection operation of FIG. 53.

Explanation of main part codes

4 Drive control circuit 7 Two-dimensional code conversion circuit 9 Electronic choke 91 Image sensor 96 Coordinate information extraction circuit 100 Plasma display panel

Claims (12)

A two-dimensional coordinate pattern displayed on a display surface composed of a plurality of pixels arranged in a matrix in the row and column directions of the display panel,
A plurality of first oblique pixel lines, each of the plurality of pixels being composed of pixel columns that are obliquely continuous with respect to the row and column directions at a predetermined interval;
A plurality of second diagonal pixel lines comprising pixel columns that are diagonally continuous with respect to the row and column directions at a predetermined interval in a direction in which each of the plurality of pixels intersects the plurality of first diagonal pixel lines; ,
A plurality of pixel blocks surrounded by the plurality of first oblique pixel lines and the plurality of second oblique pixel lines among the plurality of pixels and carrying two-dimensional coordinate data of the coordinate positions;
The pixels of each of the plurality of first diagonal pixel lines and the plurality of second diagonal pixel lines are in the same state of either one of a lighting state and a lighting state so as to represent a range of each of the plurality of pixel blocks.
Each of the plurality of pixel blocks includes a rotation detection pixel unit that is turned on or off in a predetermined display pattern in order to detect a rotation angle when reading the two-dimensional coordinate data of each individual pixel block;
Each of the pixels belonging to one of the two regions having a symmetrical relationship among the four regions divided in two directions orthogonal to each other is turned on or off according to the X coordinate data of the two-dimensional coordinate data. Information display in which each of the pixels belonging to the other two regions in the four regions which are in a symmetrical relationship among the four regions is turned on or off according to the Y coordinate data of the two-dimensional coordinate data. A coordinate pattern including a pixel portion. The display surface of the display panel includes an XY coordinate system in which the column direction is an X-axis direction and the row direction is a Y-axis direction,
The coordinate pattern according to claim 1, wherein the X coordinate data indicates an X coordinate position of the XY coordinate system, and the Y coordinate data indicates a Y coordinate position of the XY coordinate system. The display surface of the display panel includes an oblique orthogonal XY coordinate system in which an extension direction of the first oblique pixel line is an X-axis direction and an extension direction of the second oblique pixel line is a Y-axis direction,
The coordinate pattern according to claim 1, wherein the X coordinate data indicates an X coordinate position of the oblique orthogonal XY coordinate system, and the Y coordinate data indicates a Y coordinate position of the oblique orthogonal XY coordinate system.   A pixel at a position where the plurality of first oblique pixel lines and the plurality of second oblique pixel lines intersect is defined as a reference pixel, and the position of the reference pixel is defined as a division of an XY coordinate system scale on the display surface of the display panel. The coordinate pattern according to any one of claims 1 to 3, wherein:   One pixel adjacent to each other in the predetermined direction with respect to the reference pixel in each of the plurality of pixel blocks is turned on or off so as to indicate whether or not the adjacent reference pixel is valid as the division of the scale. The coordinate pattern according to claim 4, wherein:   One pixel adjacent to the reference pixel in a predetermined direction in each of the plurality of pixel blocks represents an arrangement state of the X coordinate data and the Y coordinate data in the pixel block with respect to the four regions. The coordinate pattern according to claim 4, wherein the coordinate pattern is turned on or off.   In each of the plurality of pixel blocks, the four regions include an upper right region, a lower right region, an upper left region, and a lower left region, and the rotation detection pixel unit is provided between the upper right region, the lower right region, and the upper left region and the lower left region. The coordinate pattern according to claim 1, wherein the coordinate pattern is arranged. A display device that displays a two-dimensional coordinate pattern on a display surface of a display panel composed of a plurality of pixels arranged in a matrix in the row and column directions ,
The coordinate pattern includes a plurality of first oblique pixel lines each including a pixel column in which each of the plurality of pixels continues obliquely with respect to the row and column directions at a predetermined interval;
A plurality of second diagonal pixel lines comprising pixel columns that are diagonally continuous with respect to the row and column directions at a predetermined interval in a direction in which each of the plurality of pixels intersects the plurality of first diagonal pixel lines; ,
A plurality of pixel blocks surrounded by the plurality of first oblique pixel lines and the plurality of second oblique pixel lines among the plurality of pixels and carrying two-dimensional coordinate data at the positions;
The pixels of each of the plurality of first diagonal pixel lines and the plurality of second diagonal pixel lines are in the same state of either one of a lighting state and a lighting state so as to represent a range of each of the plurality of pixel blocks.
Each of the plurality of pixel blocks includes a rotation detection pixel unit that is turned on or off in a predetermined display pattern in order to detect a rotation angle when reading the two-dimensional coordinate data of each individual pixel block;
Each of the pixels belonging to one of the two regions having a symmetrical relationship among the four regions divided in two directions orthogonal to each other is turned on or off according to the X coordinate data of the two-dimensional coordinate data. Information display in which each of the pixels belonging to the other two regions in the four regions which are in a symmetrical relationship among the four regions is turned on or off according to the Y coordinate data of the two-dimensional coordinate data. A pixel portion, and
A display device for coordinate patterns, comprising display drive means for driving the display panel to display the coordinate patterns in the display surface. A reading device for reading a coordinate pattern displayed on a display surface of a display panel composed of a plurality of pixels arranged in a matrix in a row and column direction ,
The coordinate pattern includes a plurality of first oblique pixel lines each including a pixel column in which each of the plurality of pixels continues obliquely with respect to the row and column directions at a predetermined interval;
A plurality of second diagonal pixel lines comprising pixel columns that are diagonally continuous with respect to the row and column directions at a predetermined interval in a direction in which each of the plurality of pixels intersects the plurality of first diagonal pixel lines; ,
A plurality of pixel blocks surrounded by the plurality of first oblique pixel lines and the plurality of second oblique pixel lines among the plurality of pixels and carrying two-dimensional coordinate data of the coordinate positions;
The pixels of each of the plurality of first diagonal pixel lines and the plurality of second diagonal pixel lines are in the same state of either one of a lighting state and a lighting state so as to represent a range of each of the plurality of pixel blocks.
Each of the plurality of pixel blocks includes a rotation detection pixel unit that is turned on or off in a predetermined display pattern in order to detect a rotation angle when reading the two-dimensional coordinate data of each individual pixel block;
Each of the pixels belonging to one of the two regions having a symmetrical relationship among the four regions divided in two directions orthogonal to each other is turned on or off according to the X coordinate data of the two-dimensional coordinate data. Information display in which each of the pixels belonging to the other two regions in the four regions which are in a symmetrical relationship among the four regions is turned on or off according to the Y coordinate data of the two-dimensional coordinate data. A pixel portion, and
An image sensor that obtains a photographed image signal by photographing the display surface in a photographing range including at least one pixel at a position where the plurality of first oblique pixel lines and the plurality of second oblique pixel lines intersect;
Reference pixel detection means for detecting, as a reference pixel, the pixel at the intersecting position from the captured image signal;
A plurality of read pixels are selected corresponding to the position of the reference pixel in the shooting range, and the X coordinate data and the Y coordinate are based on the lighting and extinction states of the read pixels indicated by the shot image signal. And a coordinate data detecting means for detecting each of the data.   The coordinate data detection means selects a plurality of X coordinate read pixels for the X coordinate data corresponding to the position of the reference pixel in the shooting range, and each of the X coordinate read pixels indicated by the shot image signal X-coordinate data detecting means for detecting the X-coordinate data based on the lighting and extinguishing states of the plurality of Y-coordinate reading pixels for the Y-coordinate data corresponding to the position of the reference pixel in the imaging range. 10. A Y-coordinate data detection unit that selects and detects the Y-coordinate data based on the lighting and extinction state of each Y-coordinate reading pixel indicated by the captured image signal. The reading device described. One pixel adjacent to each other in the predetermined direction with respect to the reference pixel in each of the plurality of pixel blocks is in a lit state and an unlit state when the reference pixel is valid as the division of the scale with respect to the X coordinate data. A coordinate separation pixel that is in one state and becomes the other state of the lighting state and the non-lighting state when the Y coordinate data is valid as a division of the scale.
The coordinate data detection unit is configured such that when the division pixel of the scale adjacent to the reference pixel detected by the reference pixel detection unit in the predetermined direction is in the other state, the detected reference pixel is in the imaging range. The X coordinate data and the Y coordinate data are detected based on the lighting and extinguishing states of the read pixels indicated by the captured image signal, respectively, if the reference pixel is within a predetermined range. The reading device according to claim 9. In each of the plurality of pixel blocks, one pixel adjacent in the predetermined direction with respect to the reference pixel has a first arrangement state in which the X coordinate data and the Y coordinate data in the pixel block are arranged in the four regions. An XY arrangement display pixel that is in one of a lighting state and a non-lighting state when it becomes a second arrangement state different from the first arrangement state, and is in the other state of the lighting state and the non-lighting state,
The coordinate data detection means includes the read pixels for the X coordinate data according to the state of the XY arrangement display pixels adjacent in the predetermined direction to the reference pixels detected by the reference pixel detection means, The reading apparatus according to claim 9, wherein selection of the reading pixel for the Y coordinate data is switched.

Images