JP2015158524A - Driving method of image display device, image display device and image display system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a position pointed by an electronic pen from being deviated from a plot position even when performing wobbling processing.SOLUTION: A driving method of an image display device for which one field period is formed from a plurality of sub fields including an image display sub field and a coordinate detection sub field is disclosed. The coordinate detection sub field includes: a synchronism detection sub field SFo in which light emission for synchronism is generated; a (y) coordinate detection sub field SFy in which (y) coordinate detection light emission is generated for detecting a (y) coordinate on an image display screen; and an (x) coordinate detection sub field SFx in which (x) coordinate detection light emission is generated for detecting an (x) coordinate on the image display screen. An image is displayed in the image display sub field after moving the display position thereof just by a predetermined displacement amount (δX, δY) that is set while depending on a time, and light emission timing of the (y) coordinate detection light emission and the (x) coordinate detection light emission is changed just by times (-δX Tx1) and (-δY Ty1) corresponding to the displacement amount.

Description

  The present invention relates to an image display apparatus driving method using a flat display device, an image display apparatus, and an image display system capable of drawing using an electronic pen.

  A plasma display panel, which is a typical flat display device, has a large number of discharge cells formed between two glass substrates, and generates a gas discharge in the discharge cells to produce red, green, and blue phosphors. Color display is performed by exciting light emission. As a method for driving a plasma display panel, a subfield method in which one field period is constituted by a plurality of subfields and gradation display is performed by a combination of subfields to emit light is generally used.

  In such a flat display device, if the same image is continuously displayed for a long time, an afterimage called “burn-in” may occur. In order to prevent such burn-in, for example, Patent Document 1 proposes a method of slowly moving the image display position with time (hereinafter referred to as “Wobbling”).

  On the other hand, an image display system capable of inputting characters, pictures, and the like from the image display surface, such as a blackboard or a whiteboard, using such a flat display device has been studied. These are so-called interactive boards that can be used for presentations and lectures.

  For example, in Patent Document 2, a position coordinate detection period is provided in one field only at the time of position coordinate detection using a plasma display panel, and light emission for position coordinate detection is generated within this period. Describes a coordinate position detection method for detecting the position coordinates pointed to by the electronic pen according to the timing detected by.

JP 2008-281611 A JP 2001-318765 A

  When a flat display device is used as an interactive board, the same image is often continuously displayed, and burn-in may occur. For this reason, it is desirable to use a burn-in prevention measure as described in Patent Document 1.

  However, if the wobbling process is applied to the drawing signal drawn with the electronic pen, the coordinates pointed to by the electronic pen and the display position of the drawn image will be shifted. This makes the image display system difficult to use.

  The present invention has been made in view of the above problems, and even when performing a wobbling process, it is possible to perform drawing with a natural feeling of use without causing a shift between the position indicated by the electronic pen and the drawing position. An object of the present invention is to provide an image display device driving method, an image display device, and an image display system.

  To achieve the above object, the present invention includes an image display subfield for inputting an image signal to display an image and a coordinate detection subfield for generating light emission for detecting coordinates on the image display surface. A driving method of an image display device in which one field period is constituted by a plurality of subfields, wherein the coordinate detection subfield detects a synchronization detection subfield that generates light emission for synchronization and a y coordinate on the image display surface. Including a y-coordinate detection subfield for generating y-coordinate detection light emission for detecting and an x-coordinate detection subfield for generating x-coordinate detection light emission for detecting an x-coordinate on the image display surface. The display position of the image is moved and displayed by a predetermined amount of displacement set depending on the image, and y-coordinate detection light emission and x-coordinate detection light emission are emitted. And changes by the time corresponding to timing the displacement. By this method, even when a wobbling process is performed, a driving method of an image display device capable of drawing with a natural feeling of use without causing a shift between the position indicated by the electronic pen and the drawing position is provided. Can do.

  The present invention also includes a display device, a plurality of image display subfields for inputting an image signal to display an image, and a coordinate detection subfield for generating light emission for detecting coordinates on the image display surface. An image display apparatus comprising: a drive circuit configured to drive a display device by forming one field period in a subfield, wherein the drive circuit includes a synchronization detection subfield for generating light emission for synchronization and an image display surface A plurality of y-coordinate detection subfields for generating y-coordinate detection light emission for detecting the y-coordinate and a x-coordinate detection subfield for generating x-coordinate detection light emission for detecting the x-coordinate on the image display surface. The coordinate detection subfield is configured with the subfield, and only a predetermined displacement amount set depending on time in the image display subfield is set. And displays by moving the display position of the image, and changes by the time corresponding to the light emission timing of the y-coordinate detection emission and x-coordinate detection light emission amount of displacement. With this configuration, it is possible to provide an image display device capable of drawing with a natural feeling of use without causing a shift between the position pointed to by the electronic pen and the drawing position even when the wobbling process is performed.

  An image display system according to the present invention includes the image display device described above, an electronic pen that calculates coordinates of an image display surface that is indicated based on light emission of a coordinate detection subfield, and a drawing signal based on the coordinates calculated by the electronic pen. And a drawing device that creates and outputs the image to the image display device. With this configuration, it is possible to provide an image display system capable of drawing with a natural feeling of use without causing a shift between the position pointed to by the electronic pen and the drawing position even when the wobbling process is performed.

  According to the present invention, even when a wobbling process is performed, a driving method of an image display device capable of drawing with a natural feeling of use without causing a deviation between the position indicated by the electronic pen and the drawing position, and an image A display device and an image display system can be provided.

1 is a circuit block diagram of an image display system in Embodiment 1 of the present invention. It is a disassembled perspective view of the panel of the image display system. It is an electrode array figure of the panel of the image display system. It is a drive voltage waveform figure applied to the panel of the image display system. It is a drive voltage waveform figure applied to the panel of the image display system. It is a schematic diagram explaining operation | movement of the wobbling part of the image display system. It is a schematic diagram explaining operation | movement of the wobbling part of the image display system. It is a timing chart explaining the position coordinate detection method of the image display system. It is a schematic diagram explaining the position coordinate detection method of the image display system. It is a schematic diagram which shows an example of drawing of the image display system. It is a schematic diagram for demonstrating operation | movement of the image display system. It is a schematic diagram for demonstrating operation | movement of the image display system. It is a schematic diagram for demonstrating operation | movement of the image display system. It is a drive voltage waveform figure applied to the panel of the image display system in Embodiment 2 of this invention.

  Hereinafter, an image display system according to an embodiment of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a circuit block diagram of an image display system 100 according to Embodiment 1 of the present invention. The image display system 100 includes an image display device 30, a drawing device 40, and an electronic pen 50. A plurality of electronic pens 50 may be provided.

  The image display device 30 includes a display device that displays an image and a drive circuit that drives the display device. Hereinafter, an image display apparatus 30 using a plasma display panel (abbreviated as “panel”) 10 as a display device will be described as an example. However, an image display apparatus using a display device such as a liquid crystal or an organic EL may be used. .

  FIG. 2 is an exploded perspective view of panel 10 of image display system 100 according to Embodiment 1 of the present invention. On the glass front substrate 11, a plurality of display electrode pairs 14 made up of scanning electrodes 12 and sustaining electrodes 13 are formed. A dielectric layer 15 is formed so as to cover the display electrode pair 14, and a protective layer 16 is formed on the dielectric layer 15. A plurality of data electrodes 22 are formed on the rear substrate 21, a dielectric layer 23 is formed so as to cover the data electrodes 22, and a grid-like partition wall 24 is formed thereon. A phosphor layer 25 that emits red, green, and blue light is provided on the side surface of the partition wall 24 and on the dielectric layer 23.

  The front substrate 11 and the rear substrate 21 are arranged to face each other so that the display electrode pair 14 and the data electrode 22 intersect with each other with a minute discharge space interposed therebetween, and the outer periphery thereof is sealed with a sealing material such as glass frit. Has been. In the discharge space, for example, a mixed gas of neon and xenon is sealed as a discharge gas. The discharge space is partitioned into a plurality of sections by barrier ribs 24, and discharge cells are formed at portions where display electrode pairs 14 and data electrodes 22 intersect. When these discharge cells discharge and emit light, the phosphor layer 25 emits light and an image is displayed.

  FIG. 3 is an electrode array diagram of panel 10 of image display system 100 according to Embodiment 1 of the present invention. In panel 10, n scan electrodes SC1 to SCn (scan electrode 12 in FIG. 1) and n sustain electrodes SU1 to SUn (sustain electrode 13 in FIG. 1) extending in the row direction are arranged in the column direction. The extended m data electrodes D1 to Dm (data electrode 22 in FIG. 1) are arranged. A discharge cell is formed at a portion where one pair of scan electrode SCi (i = 1 to n) and sustain electrode SUi intersects one data electrode Dj (j = 1 to m), and the discharge cell is in the discharge space. M × n are formed. Here, the three discharge cells formed at the intersection of the three adjacent data electrodes and the pair of display electrodes are a red sub-pixel, a green sub-pixel, and a blue sub-pixel. The red subpixel, the green subpixel, and the blue subpixel constitute one pixel as a set. Therefore, for example, if the panel 10 is a high definition panel having 1080 × 1920 pixels, n = 1080 and m = 1920 × 3 = 5760.

  Next, the drive voltage waveform applied to each electrode of panel 10 will be described. In the present embodiment, a plurality of image display subfields for inputting an image signal to display an image and a coordinate detection subfield for generating light emission for detecting coordinates on the image display surface are provided. One field period is composed of subfields.

  First, details of the image display subfield will be described. The image display subfield includes a plurality of subfields having a predetermined luminance weight, and displays an image by controlling light emission / non-light emission of each image display subfield for each discharge cell.

  In the present embodiment, the image display subfield is eight subfields SF1 to SF8 having an initialization period Pi, an address period Pw, and a sustain period Ps. The luminance weights of the subfields SF1 to SF8 are, for example, ( 1, 34, 21, 13, 8, 5, 3, 2). However, the subfield configuration such as the number of subfields and the luminance weight is not limited to the above.

  FIG. 4 is a drive voltage waveform diagram applied to panel 10 of image display system 100 according to Embodiment 1 of the present invention, and shows drive voltage waveforms applied to each electrode of panel 10 in subfields SF1 to SF3. .

  In the initializing period Pi of subfield SF1, a predetermined voltage is applied to each electrode to generate a weak initializing discharge, and the wall voltages on scan electrodes SC1 to SCn and sustain electrodes SU1 to SUn are weakened. Further, the wall voltage on the data electrodes D1 to Dm is adjusted to a value suitable for the write operation. In the present embodiment, a rising ramp voltage that gently rises and a falling ramp voltage that slowly falls are applied to scan electrodes SC1 to SCn.

  In the subsequent address period Pw, voltage 0 (V) is applied to data electrodes D1 to Dm, voltage Ve is applied to sustain electrodes SU1 to SUn, and voltage Vc is applied to scan electrodes SC1 to SCn.

  Next, a scan pulse of voltage Va is applied to scan electrode SC1 in the first row, and voltage is applied to data electrode Dk (k = 1 to m) of the discharge cell to be emitted in the first row among data electrodes D1 to Dm. Vd write pulse is applied. Then, an address discharge is generated in the discharge cell to which the address pulse is applied, and a wall voltage for generating a sustain discharge is accumulated on scan electrode SC1 and sustain electrode SU1. On the other hand, in the discharge cells to which no address pulse is applied, no address discharge occurs and no wall voltage is accumulated on scan electrode SC1 and sustain electrode SU1.

  Next, a scan pulse is applied to scan electrode SC2 in the second row, and an address pulse is applied to data electrode Dk of the discharge cell to be emitted in the second row among data electrodes D1 to Dm. Then, an address discharge is generated in the discharge cell to which the address pulse is applied, and a wall voltage for generating a sustain discharge is accumulated on scan electrode SC2 and sustain electrode SU2.

  Similarly, scan pulses are sequentially applied to scan electrodes SC3 to SCn, and address pulses are applied to data electrodes Dk of the discharge cells to be lit to sequentially discharge the discharge cells to be emitted in the third to nth rows. An address discharge is generated.

  In the subsequent sustain period Ps, a sustain pulse of voltage Vs is applied to scan electrodes SC1 to SCn, and voltage 0 (V) is applied to sustain electrodes SU1 to SUn. Then, a sustain discharge occurs in the discharge cell in which the address discharge has occurred. Then, the polarities of the wall voltage on scan electrode SCi and the wall voltage on sustain electrode SUi are reversed. On the other hand, in the discharge cells in which no address discharge has occurred in the address period Pw, no sustain discharge occurs, and the wall voltage at the end of the initialization period Pi is maintained.

  Subsequently, voltage 0 (V) is applied to scan electrodes SC1 to SCn, and a sustain pulse is applied to sustain electrodes SU1 to SUn. Then, the sustain discharge occurs again in the discharge cell that has generated the sustain discharge, and the polarity of the wall voltage on scan electrode SCi and the wall voltage on sustain electrode SUi are reversed. Similarly, sustain pulses of the number corresponding to the luminance weight are alternately applied to scan electrodes SC1 to SCn and sustain electrodes SU1 to SUn, and sustain discharge is continuously generated in the discharge cells that have caused address discharge in address period Pw. Let

  At the end of sustain period Ps, a predetermined voltage is applied to each electrode to generate a weak erasure discharge in the discharge cell that has generated the sustain discharge, thereby weakening the wall voltage on scan electrode SCi and sustain electrode SUi. . In the present embodiment, a rising ramp voltage that gradually increases is applied to scan electrodes SC1 to SCn.

  In the initializing period Pi of subfield SF2, a predetermined voltage is applied to each electrode to generate a weak initializing discharge, and the wall voltages on scan electrodes SC1 to SCn and sustain electrodes SU1 to SUn are weakened. Further, the wall voltage on the data electrodes D1 to Dm is adjusted to a value suitable for the write operation. In the present embodiment, a gradually decreasing downward ramp voltage is applied to scan electrodes SC1 to SCn.

  Since the operation in the writing period Pw of the subfield SF2 is the same as the operation in the writing period Pw of the subfield SF1, description thereof is omitted. The operation in subsequent sustain period Ps is similar to the operation in sustain period Ps of subfield SF1 except for the number of sustain pulses. The operations of subfields SF3 to SF8 are the same as those of subfield SF2 except for the number of sustain pulses.

  Next, details of the coordinate detection subfield will be described. The coordinate detection subfield includes a synchronization detection subfield SFo for generating light emission for synchronization, a y coordinate detection subfield SFy for generating y coordinate detection light emission for detecting the y coordinate on the image display surface, and an image. An x-coordinate detection subfield SFx that generates x-coordinate detection light emission for detecting an x-coordinate on the display surface. The synchronization detection subfield SFo is a subfield for establishing synchronization between the electronic pen 50 and the image display device 30. The y coordinate detection subfield SFy is a subfield for detecting the y coordinate on the display screen indicated by the electronic pen 50. The x-coordinate detection subfield SFx is a subfield for detecting the x-coordinate on the display screen indicated by the electronic pen 50.

  In the present embodiment, for the following explanation, the coordinate of the upper left corner on the image display surface of panel 10 is defined as the coordinate origin (0, 0), and the right direction is the direction in which the X coordinate increases, The direction is defined as the direction in which the Y coordinate increases.

  FIG. 5 is a waveform diagram of drive voltages applied to panel 10 of image display system 100 according to Embodiment 1 of the present invention. In the synchronization detection subfield SFo, y-coordinate detection subfield SFy, and x-coordinate detection subfield SFx, FIG. The drive voltage waveform applied to each electrode of 10 is shown.

  In the initialization period Pi of the synchronization detection subfield SFo, a predetermined voltage is applied to each electrode to generate a weak initialization discharge, and the wall voltages on the scan electrodes SC1 to SCn and the sustain electrodes SU1 to SUn are weakened. Further, the wall voltage on the data electrodes D1 to Dm is adjusted to a value suitable for the write operation.

  In the address period Pw of the synchronization detection subfield SFo, first, the voltage 0 (V) is applied to the data electrodes D1 to Dm, the voltage Ve is applied to the sustain electrodes SU1 to SUn, and the voltage Vc is applied to the scan electrodes SC1 to SCn. . Thereafter, an address pulse of voltage Vd is applied to data electrodes D1 to Dm, and a scan pulse of voltage Va is sequentially applied to each of a plurality of scan electrodes SC1 to SCn to generate address discharges in all the discharge cells.

  In the synchronization detection period Po of the synchronization detection subfield SFo, at time to1, a voltage Vso synchronization detection pulse is applied to the scan electrodes SC1 to SCn and a voltage 0 (V) is applied to the sustain electrodes SU1 to SUn. A synchronous detection discharge is generated in the discharge cell. Next, at time to2 after time To1 has elapsed from time to1, voltage 0 (V) is applied to scan electrodes SC1 to SCn and a synchronous detection pulse is applied to sustain electrodes SU1 to SUn to generate synchronous detection discharge again. Let Next, at time to3 after the lapse of time To2 from time to2, a synchronization detection pulse is applied to scan electrodes SC1 to SCn, and voltage 0 (V) is applied to sustain electrodes SU1 to SUn. Is generated. Subsequently, at time to4 after time To3 has elapsed from time to3, voltage 0 (V) is applied to scan electrodes SC1 to SCn and a synchronous detection pulse is applied to sustain electrodes SU1 to SUn, and a fourth synchronous detection discharge is performed. generate. In the present embodiment, the time To1, the time To2, and the time To3 are, for example, 40 μs, 20 μs, and 30 μs, respectively.

  At the end of the synchronization detection period Po, a predetermined voltage is applied to each electrode to generate a weak erasure discharge in the discharge cell that has generated the sustain discharge, and on the scan electrodes SC1 to SCn and the sustain electrodes SU1 to SUn. Reduce the wall voltage.

  In the initialization period Pi of the y-coordinate detection subfield SFy, the voltage 0 (V) is applied to the data electrodes D1 to Dm, the voltage 0 (V) is applied to the sustain electrodes SU1 to SUn, and the scan electrodes SC1 to SCn rise. The ramp voltage is applied to generate a weak initializing discharge, and the wall voltages on scan electrodes SC1 to SCn and sustain electrodes SU1 to SUn are weakened. Further, the wall voltage on the data electrodes D1 to Dm is adjusted to a value suitable for the y coordinate detection discharge.

  In the y coordinate detection period Py of the y coordinate detection subfield SFy, first, the voltage 0 (V) is applied to the data electrodes D1 to Dm, the voltage Ve is applied to the sustain electrodes SU1 to SUn, and the voltage Vc is applied to the scan electrodes SC1 to SCn. Apply. This state is maintained for a predetermined time (Ty0−δY · Ty1). Here, the time Ty0 is a predetermined time, which is 700 μs in the present embodiment. Although details will be described later, δY is the amount of displacement of the image in the y-axis direction (downward) by the wobbling process, and time Ty1 is the time for applying the y-coordinate detection pulse. The displacement amount δY in the y-axis direction is a positive value, a negative value, or “0”.

  Next, the y coordinate detection voltage Vdy is applied to the data electrodes D1 to Dm, and the y coordinate detection pulse of the voltage Vay is applied to the scan electrode SC1 in the first row. Then, discharge occurs in the discharge cells in the first row. In this way, the discharge for detecting the y coordinate is simultaneously generated in the first discharge cell, and the y coordinate is detected in the first discharge cell row composed of the first pixel row, that is, the first discharge cell. Light emission (y coordinate detection light emission) occurs.

  Next, the y coordinate detection pulse is applied to the scan electrode SC2 in the second row while the y coordinate detection voltage Vdy is applied to the data electrodes D1 to Dm. Then, y coordinate detection light emission occurs in the second pixel row, that is, the second discharge cell row. Similarly, the y coordinate detection pulse is sequentially applied to the scan electrodes SC3 to SCn while the y coordinate detection voltage Vdy is applied to the data electrodes D1 to Dm, and the discharge cells in the third to nth rows are sequentially y. Coordinate detection light emission is generated. Here, the time Ty1 for applying the y-coordinate detection pulse is, for example, 1 μs.

  In this way, during the y coordinate detection period Py, it is displayed that one horizontal line moves from the upper end portion to the lower end portion of the image display surface. Therefore, as described later, the y coordinate of the position of the display screen indicated by the electronic pen can be detected by receiving the light emission of the discharge cell row with the electronic pen 50 and knowing the timing of the light emission. However, in this embodiment, the light emission timing of the y-coordinate detection light emission is changed by time (−δY · Ty1) along with the wobbling process. Since the moving speed of the horizontal line is very fast, it looks visually as if the entire display screen is slightly brighter.

  In the erasing period Pe of the y-coordinate detection subfield SFy, the voltage 0 (V) is applied to the data electrodes D1 to Dm, the voltage 0 (V) is applied to the sustain electrodes SU1 to SUn, and the scan electrodes SC1 to SCn are inclined upward. A voltage is applied to generate a weak erasing discharge in each discharge cell, and the wall voltages on scan electrodes SC1 to SCn and sustain electrodes SU1 to SUn are weakened.

  In the present embodiment, the y coordinate detection period Py is shortened by the time (δY · Ty1) depending on the wobbling process, but the erase period is lengthened accordingly, so the time of the y coordinate detection subfield SFy. The typical length is constant without depending on the wobbling process.

  In the initialization period Pi of the x-coordinate detection subfield SFx, a predetermined voltage is applied to each electrode to generate a weak initialization discharge, thereby weakening the wall voltage on the scan electrodes SC1 to SCn and the sustain electrodes SU1 to SUn. . Further, the wall voltage on the data electrodes D1 to Dm is adjusted to a value suitable for the x coordinate detection discharge.

  In the x coordinate detection period Px of the x coordinate detection subfield SFx, the voltage 0 (V) is applied to the data electrodes D1 to Dm, the voltage Ve is applied to the sustain electrodes SU1 to SUn, and the voltage Vc is applied to the scan electrodes SC1 to SCn. Apply. This state is maintained for a predetermined time (Tx0−δX · Tx1). Here, the time Tx0 is a predetermined time, which is 700 μs in the present embodiment. Although details will be described later, δX is the amount of displacement of the image in the x-axis direction (right direction) by the wobbling process, and time Tx1 is the time for applying the x-coordinate detection pulse. The displacement amount δX in the x-axis direction is a positive value, a negative value, or “0”.

  Next, the x-coordinate detection voltage Vax is applied to the scan electrodes SC1 to SCn, and the first to third columns of data corresponding to one pixel, that is, the red subpixel, the green subpixel, and the blue subpixel. An x coordinate detection pulse of voltage Vdx is applied to the electrodes D1 to D3. Then, discharge occurs in the discharge cells in the first to third columns. In this way, discharge for detecting the x coordinate is simultaneously generated in the discharge cells in the first column to the third column, and the first discharge cell configured by the first pixel column, that is, the first column discharge cell. Light emission for x-coordinate detection (light emission for x-coordinate detection) in the second discharge cell line constituted by the second and second discharge cells, and the third discharge cell line constituted by the third discharge cell ) Occurs.

  Next, with the x coordinate detection voltage Vax being applied to the scan electrodes SC1 to SCn, the x coordinate detection pulse of the voltage Vdx is applied to the data electrodes D4 to D6 in the fourth column to the sixth column. Then, x coordinate detection light emission occurs in the second pixel column, that is, the fourth to sixth discharge cell columns.

  Similarly, the x-coordinate detection pulse is sequentially applied to each of the three data electrodes until reaching the data electrode Dm, and the x-coordinate detection light emission is sequentially performed every three discharge cell rows until the m-th discharge cell row. generate. Here, the time Tx1 for applying the x-coordinate detection pulse is, for example, 1 μs.

  Thus, in the x coordinate detection period Px, one vertical line is displayed as moving from the left end to the right end of the image display surface. Therefore, as described later, the x coordinate of the position of the display screen indicated by the electronic pen 50 can be detected by receiving the light emission of the discharge cell array with the electronic pen 50 and knowing the timing of the light emission. However, in the present embodiment, the light emission timing of the x coordinate detection light emission is changed by time (−δX · Tx1) along with the wobbling process. Since the moving speed of the vertical line is very fast, it looks visually as if the entire display screen is slightly brighter.

  In the erase period Pe of the x-coordinate detection subfield SFx, the voltage 0 (V) is applied to the data electrodes D1 to Dm, the voltage 0 (V) is applied to the sustain electrodes SU1 to SUn, and the scan electrodes SC1 to SCn are inclined upward. A voltage is applied to generate a weak erasing discharge in each discharge cell, and the wall voltages on scan electrodes SC1 to SCn and sustain electrodes SU1 to SUn are weakened.

  Thus, the coordinate detection period ends. In this embodiment, the voltage value applied to each electrode is, for example, voltage Va = voltage Vay = voltage Vax = −200 (V), voltage Vc = −50 (V), voltage Vs = voltage Vso = 205 (V ), Voltage Ve = 155 (V), voltage Vd = voltage Vdy = voltage Vdx = 55 (V). However, these voltage values are merely examples, and it is desirable to set them to optimal values as appropriate in accordance with the characteristics of the panel 10 and the specifications of the image display device 30.

  Next, the drive circuit of the image display device 30 will be described. As shown in FIG. 1, the drive circuit of the image display device 30 includes an image signal processing unit 31, a data electrode drive unit 32, a scan electrode drive unit 33, a sustain electrode drive unit 34, a control unit 35, A wobbling section 36 and a power supply section (not shown) for supplying power necessary for each circuit block are provided.

  The wobbling unit 36 performs a wobbling process on the image signal sig1 input from the drawing device 40, and outputs it as an image signal sig2.

  6A and 6B are schematic diagrams for explaining the operation of the wobbling section 36 of the image display system 100 according to Embodiment 1 of the present invention. FIG. 6A shows a character string “ABC” as an example of an image. If such a character string is continuously displayed for a long time, burn-in may occur. Therefore, the wobbling unit 36 moves the image display position of the input image signal sig1 at a very slow speed and outputs it as the image signal sig2. FIG. 6B shows an example of the image signal sig2 obtained by moving the image of the image signal sig1 by the coordinate δX in the X direction (right direction) and by the coordinate δY in the Y direction (downward direction). For example, if the coordinates at the end of writing of the character “C” shown in FIG. 6A are coordinates (X, Y), the coordinates at the end of writing of the character “C” of the image signal sig2 after the wobbling process are as shown in FIG. 6B. , Coordinates (X + δX, Y + δY). Here, coordinates δX and coordinates δY are functions of time that change at a very slow rate with time. Thus, in the present embodiment, image sticking is prevented by moving the image display position by a predetermined displacement amount (δX, δY) set depending on time in the image display subfield.

  Further, the wobbling unit 36 outputs the displacement amount (δX, δY) of the image to the control unit 35.

  The image signal processing unit 31 converts the image signal sig2 output from the wobbling unit 36 into image data indicating light emission / non-light emission for each subfield.

  As shown in FIG. 4, in the image display subfield, the data electrode driver 32 converts the image data into address pulses corresponding to the data electrodes D1 to Dm, and applies them to the data electrodes D1 to Dm. . In the coordinate detection subfield, the drive voltage waveform shown in FIG. 5 is applied to each of the data electrodes D1 to Dm.

  Scan electrode driver 33 applies the drive voltage waveforms shown in FIGS. 4 and 5 to each of scan electrodes SC1 to SCn, and sustain electrode driver 34 maintains the drive voltage waveforms shown in FIGS. Apply to each of the electrodes SU1 to SUn.

  The control unit 35 generates various control signals for generating the drive voltage waveforms shown in FIGS. 4 and 5 in each circuit block of the drive circuit, and supplies them to the respective circuit blocks. In particular, in the coordinate detection subfield, a predetermined time (Ty0−δY · Ty1) of the y coordinate detection period Py of the y coordinate detection subfield SFy is set based on the displacement amounts (δX, δY) output from the wobbling unit 36. , A predetermined time (Tx0−δX · Tx1) of the x coordinate detection period Px of the x coordinate detection subfield SFx is set.

  Next, the electronic pen 50 will be described. The electronic pen 50 is used to input characters and pictures from the image display surface of the panel 10, receives light emitted from the panel 10, and outputs y and x coordinates on the image display surface indicated. The electronic pen 50 includes a drawing switch 51, a light receiving element 52, a synchronization detection unit 53, a coordinate calculation unit 54, and a transmission unit 55.

  The drawing switch 51 is attached near the tip of the electronic pen 50, and is turned on when the electronic pen 50 is in contact with the image display surface of the panel 10, and is turned off when the electronic pen 50 is separated from the image display surface.

  The light receiving element 52 is attached to the tip of the electronic pen 50, receives light emitted from the panel 10, and outputs a light reception signal to each of the synchronization detection unit 53 and the coordinate calculation unit 54.

  The synchronization detection unit 53 detects a plurality of continuous light emissions at predetermined intervals from the received light signal, creates a coordinate reference signal synchronized with the drive of the image display device 30, and sends it to the coordinate calculation unit 54. Output.

  FIG. 7 is a timing chart for explaining a position coordinate detection method of the image display system 100 according to Embodiment 1 of the present invention, and shows a light reception signal and a coordinate reference signal. In the present embodiment, the electronic pen 50 searches the received light signal for four consecutive lights whose light emission intervals are time To1, time To2, and time To3. When the electronic pen 50 detects four consecutive light emissions, the y coordinate is detected based on a predetermined time Toy and a time Tox based on one of the light emissions, for example, the light emission generated at time to1. A coordinate reference signal having rises at the start time ty0 of the period Py and the start time tx0 of the x coordinate detection period Px is generated and output to the coordinate calculation unit 54.

  The electronic pen 50 is not notified of the image displacement (δX, δY) due to the wobbling process.

  The coordinate calculation unit 54 includes a counter for measuring the length of time and an arithmetic circuit that performs an operation on the output of the counter. Then, the x coordinate and the y coordinate of the image display surface pointed to by the electronic pen 50 are calculated based on the coordinate reference signal and the light reception signal.

  FIG. 8 is a schematic diagram for explaining a position coordinate detection method of the image display system 100 according to Embodiment 1 of the present invention. As described above, in the y coordinate detection period Py of the y coordinate detection subfield SFy, the horizontal line Ly moving from the upper end portion to the lower end portion of the image display surface is displayed. Then, at the time tyy when the horizontal line Ly passes through the coordinates of the image display surface pointed to by the electronic pen 50, the light receiving element of the electronic pen 50 receives the light emission of the horizontal line Ly. Therefore, the light receiving element outputs a light receiving signal indicating light reception at time tyy as shown in FIG.

  In the x coordinate detection period Px of the x coordinate detection subfield SFx, a vertical line Lx that moves from the left end portion to the right end portion of the image display surface is displayed. At a time txx when the vertical line Lx passes through the coordinates of the image display surface pointed to by the electronic pen 50, the light receiving element of the electronic pen 50 receives the light emission of the vertical line Lx. Therefore, the light receiving element outputs a light reception signal indicating light reception at time txx.

The coordinate calculation unit 54 measures the time Tyy from the time ty0 to the time tyy based on the coordinate reference signal and the light reception signal in the y coordinate detection subfield SFy. Next, the time Ty0 is subtracted from the time Tyy. Then, the y coordinate Y is obtained by dividing the time (Tyy−Ty0) by the time Ty1. That is,
y coordinate: (Tyy-Ty0) / Ty1
It is.

In the x-coordinate detection subfield SFx, a time Txx from the time tx0 to the time txx is measured based on the coordinate reference signal and the light reception signal. Next, the time Tx0 is subtracted from the time Txx. Then, the time (Txx−Tx0) is divided by the time Tx1 to obtain the x coordinate X. That is,
x coordinate: (Txx−Tx0) / Tx1
It is.

  The coordinates calculated in this way can match the position indicated by the electronic pen and the drawing position even when performing a wobbling process, as will be described later.

  The transmission unit 55 encodes the coordinates calculated by the coordinate calculation unit 54 and transmits them to the drawing apparatus 40 wirelessly.

  Next, the drawing apparatus 40 will be described. The drawing device 40 creates an image signal based on the coordinates of the image display surface pointed to by the electronic pen 50. This image signal is for displaying an image drawn by the user. The drawing device 40 includes a receiving unit 41, a drawing unit 42, and a signal switching unit 43.

  The receiving unit 41 decodes a radio signal transmitted from the transmitting unit 55 of the electronic pen 50, converts the signal into coordinates, and outputs the coordinate to the drawing unit 42.

  The drawing unit 42 includes a frame memory, generates a drawing signal indicating the locus of the electronic pen 50 on the image display surface based on the coordinates calculated by the coordinate calculation unit 54 of the electronic pen 50, and outputs the drawing signal to the image display device 30.

  FIG. 9 is a schematic diagram illustrating an example of drawing of the image display system 100 according to Embodiment 1 of the present invention. The drawing unit 42 writes a pattern such as a circle of a predetermined color and size in the frame memory around the pixel corresponding to the coordinates calculated by the coordinate calculation unit 54. When the user moves the electronic pen 50 in contact with the image display surface of the image display device 30, the coordinates calculated by the coordinate calculation unit 54 also move. Then, the drawing unit 42 sequentially writes a predetermined pattern in the frame memory around the moving coordinates. In this way, the drawing unit 42 creates a drawing signal indicating the locus of the electronic pen 50 on the image display surface as shown in FIG.

  The signal switching unit 43 has an image signal input terminal for inputting a presentation image or the like, and switches or synthesizes the input image signal and the drawing signal output from the drawing unit 42 to display an image. Output to device 30. Thereby, the image written with the electronic pen 50 and the image of the input image signal are switched or superimposed and displayed.

  Next, the operation of the image display system 100 will be described. 10A to 10C are schematic diagrams for explaining the operation of the image display system 100 according to Embodiment 1 of the present invention.

  Here, FIG. 10A shows an image when the drawing signal written in the frame memory of the drawing unit 42 is displayed on the image display device 30 without performing the wobbling process. Note that the coordinates at the end of writing of the character “C” are coordinates (X, Y).

  Actually, since the wobbling process is performed by the image display device 30, the character string “ABC” is displayed at the position shown in FIG. 10B. At this time, the end of writing of the character “C” is displayed at the position of coordinates (X + δX, Y + δY).

  It is assumed that the user brings the electronic pen 50 into contact with the point at which the last character “C” of the character string “ABC” has been written. Here, if it is assumed that the display timing of the moving horizontal line Ly is not changed in the y coordinate detection period Py, the electronic pen 50 outputs the y coordinate (Y + δY). If it is assumed that the display timing of the moving vertical line Lx is not changed in the x coordinate detection period Px, the electronic pen 50 outputs the x coordinate (X + δX). Then, the drawing unit 42 of the drawing device 40 writes a pattern such as a circle of a predetermined color and size in the frame memory with the pixel corresponding to the coordinates (X + δX, Y + δY) calculated by the coordinate calculation unit 54 as the center. Then, the wobbling unit 36 performs a wobbling process on the pattern of coordinates (X + δX, Y + δY), and displays the coordinates of the image display surface pointed to by the electronic pen 50 at the coordinates (X + 2δX, Y + 2δY) (“K1” in FIG. 10C). The position indicated by.

  However, in the present embodiment, the display of the moving horizontal line is changed by time (−δY · Ty1) in the y-coordinate detection period Py, so that the electronic pen 50 corrects the y-coordinate corrected for the displacement amount δY by the wobbling process ( Y) is output. Further, in the x coordinate detection period Px, the display of the moving vertical line is changed by time (−δX · Tx1), so the electronic pen 50 outputs the x coordinate (X) obtained by correcting the displacement amount δX by the wobbling process.

  Then, the drawing unit 42 of the drawing apparatus 40 writes a pattern such as a circle of a predetermined color and size in the frame memory with the pixel corresponding to the coordinates (X, Y) calculated by the coordinate calculation unit 54 as the center. Then, the wobbling unit 36 performs a wobbling process on the coordinate (X, Y) pattern, and displays the coordinates of the image display surface pointed to by the electronic pen 50 at the coordinates (X + δX, Y + δY) (“K0” in FIG. 10C). The position indicated by).

  As described above, in this embodiment, even when the wobbling process is performed in the image display device 30, the light emission timings of the y-coordinate detection light emission and the x-coordinate detection light emission are set to the time corresponding to the displacement amount (−δY · Ty1). ), By changing (−δX · Tx1), the position indicated by the electronic pen 50 and the drawing position are matched without notifying the electronic pen 50 and the drawing device 40 of the displacement amount (δX, δY) of the image. be able to.

  In the present embodiment, it is assumed that the time length of each subfield, in particular, the length of the y-coordinate detection subfield SFy does not depend on the displacement amount of the wobbling image. However, when the length of the y-coordinate detection subfield SFy changes by the time (−δY · Ty0) according to the wobbling process, the time (δY · Ty0) may be corrected in the subsequent x-coordinate detection subfield SFx. . An example of such a drive waveform will be described below as a second embodiment.

(Embodiment 2)
FIG. 11 is a drive voltage waveform diagram applied to panel 10 of image display system 100 according to the second embodiment of the present invention. In the synchronization detection subfield SFo, y-coordinate detection subfield SFy, and x-coordinate detection subfield SFx, FIG. The drive voltage waveform applied to each electrode of 10 is shown. FIG. 11 shows another example of the driving voltage waveform applied to each electrode in the initialization period Pi and the erasing period Pe of each subfield.

  In the initialization period Pi of the synchronization detection subfield SFo, the voltage 0 (V) is applied to the data electrodes D1 to Dm, the voltage 0 (V) is applied to the sustain electrodes SU1 to SUn, and the voltage Vi1 is applied to the scan electrodes SC1 to SCn. To the voltage Vi2 is applied. At this time, as shown in FIG. 11, the data electrodes D1 to Dm may be set to a high impedance state after the voltage is set to 0 (V). Next, the voltage 0 (V) is applied to the data electrodes D1 to Dm, the voltage Ve is applied to the sustain electrodes SU1 to SUn, and the downward ramp voltage descending from the voltage 0 (V) to the voltage Vi4 is applied to the scan electrodes SC1 to SCn. Apply. At this time, as shown in FIG. 11, the voltage Ve may be applied to the sustain electrodes SU1 to SUn, and then the high impedance state may be set.

  Then, a weak initializing discharge occurs in all the discharge cells, the wall voltage on scan electrodes SC1 to SCn and the wall voltage on sustain electrodes SU1 to SUn are weakened, and the wall voltage on data electrodes D1 to Dm is written. It is adjusted to a value suitable for operation.

  The subsequent writing period Pw and synchronization detection period Po of the synchronization detection subfield SFo are the same as those in the first embodiment, and thus the description thereof is omitted. At the end of the synchronization detection period Po, voltage 0 (V) is applied to data electrodes D1 to Dm, voltage 0 (V) is applied to sustain electrodes SU1 to SUn, and voltage 0 (V) is applied to scan electrodes SC1 to SCn. ) To a voltage Vr, and a weak erasing discharge is generated in all the discharge cells.

  In the initialization period Pi of the y-coordinate detection subfield SFy, the voltage 0 (V) is applied to the data electrodes D1 to Dm, the voltage 0 (V) is applied to the sustain electrodes SU1 to SUn, and the voltage is applied to the scan electrodes SC1 to SCn. A downward ramp voltage that falls from 0 (V) to voltage Vi4 is applied. Next, voltage 0 (V) is applied to data electrodes D1 to Dm, voltage 0 (V) is applied to sustain electrodes SU1 to SUn, and voltage Vs is applied to scan electrodes SC1 to SCn. Next, voltage Vs is applied to sustain electrodes SU1 to SUn, and voltage 0 (V) is applied to scan electrodes SC1 to SCn. Next, voltage Ve is applied to sustain electrodes SU1 to SUn, and a downward ramp voltage that drops from voltage 0 (V) to voltage Vi4 is applied to scan electrodes SC1 to SCn. Also at this time, as shown in FIG. 11, the voltage Ve may be applied to the sustain electrodes SU1 to SUn and then the high impedance state may be set.

  Then, a weak initializing discharge occurs in all discharge cells, the wall voltage on scan electrodes SC1 to SCn and the wall voltage on sustain electrodes SU1 to SUn are weakened, and the wall voltage on data electrodes D1 to Dm is detected by the y coordinate. Is adjusted to a value suitable for discharge.

  In the y coordinate detection period Py of the y coordinate detection subfield SFy, as in the first embodiment, first, the voltage 0 (V) is applied to the data electrodes D1 to Dm, and the voltage Ve is applied to the sustain electrodes SU1 to SUn. Voltage Vc is applied to scan electrodes SC1 to SCn. This state is maintained for a predetermined time (Ty0−δY · Ty1). After that, the y-coordinate detection pulse is sequentially applied to the scan electrodes SC1 to SCn while the y-coordinate detection voltage Vdy is applied to the data electrodes D1 to Dm, and the first to nth discharge cell rows are caused to emit light sequentially. .

  In the erasing period Pe of the y-coordinate detection subfield SFy, the voltage 0 (V) is applied to the data electrodes D1 to Dm, the voltage 0 (V) is applied to the sustain electrodes SU1 to SUn, and the voltage 0 is applied to the scan electrodes SC1 to SCn. An upward ramp voltage rising from (V) to the voltage Vr is applied to generate a weak erase discharge in all the discharge cells.

  In the second embodiment, it is assumed that the time length of the erasing period is constant. For this reason, the temporal length of the y-coordinate detection subfield SFy also changes by time (−δY · Ty1) depending on the wobbling process.

  In the initialization period Pi of the x-coordinate detection subfield SFx, the voltage 0 (V) is applied to the data electrodes D1 to Dm, the voltage 0 (V) is applied to the sustain electrodes SU1 to SUn, and the voltage is applied to the scan electrodes SC1 to SCn. An upward ramp voltage that rises from Vi1 to voltage Vi2 is applied. At this time, as shown in FIG. 4, the data electrodes D1 to Dm may be set to a high impedance state after the voltage is set to 0 (V). Next, the voltage 0 (V) is applied to the data electrodes D1 to Dm, the voltage Ve is applied to the sustain electrodes SU1 to SUn, and the downward ramp voltage descending from the voltage 0 (V) to the voltage Va is applied to the scan electrodes SC1 to SCn. Apply. Then, a weak initializing discharge occurs in all the discharge cells, the wall voltage on scan electrodes SC1 to SCn and the wall voltage on sustain electrodes SU1 to SUn are weakened, and the wall voltage on data electrodes D1 to Dm becomes x It is adjusted to a value suitable for discharge for coordinate detection.

  In the x coordinate detection period Px of the x coordinate detection subfield SFx, the voltage 0 (V) is applied to the data electrodes D1 to Dm, the voltage Ve is applied to the sustain electrodes SU1 to SUn, and the voltage 0 (to the scan electrodes SC1 to SCn). V) is applied. This state is maintained for a predetermined time (Tx00 + δY · Ty1−δX · Tx1). Then, an ascending ramp voltage that increases from voltage Vi1 to voltage Vi2 is applied to scan electrodes SC1 to SCn, and a descending ramp voltage that decreases from voltage 0 (V) to voltage Vax is applied to scan electrodes SC1 to SCn. The time between them is set as time Tx01, and the time (Tx00 + Tx01) is set again as time Tx0.

  Thereafter, an x coordinate detection pulse is sequentially applied to each of the three data electrodes until reaching the data electrode Dm, and light is emitted in sequence until the discharge cell row reaches the mth discharge cell row by three discharge cell rows.

  In the erasing period Pe of the x-coordinate detection subfield SFx, the voltage 0 (V) is applied to the data electrodes D1 to Dm, the voltage 0 (V) is applied to the sustain electrodes SU1 to SUn, and the voltage 0 is applied to the scan electrodes SC1 to SCn. An upward ramp voltage rising from (V) to voltage Vi2 is applied. At this time, as shown in FIG. 4, the data electrodes D1 to Dm may be set to a high impedance state after the voltage is set to 0 (V). Thereafter, the voltage 0 (V) is applied to the data electrodes D1 to Dm, the voltage 0 (V) is applied to the sustain electrodes SU1 to SUn, and the scan electrodes SC1 to SCn are descended from the voltage 0 (V) to the voltage Vi4. Apply ramp voltage. Thus, a weak erase discharge is generated in all the discharge cells.

  Even when driven in this way, the coordinate calculation unit 54 can calculate the coordinates (X, Y). Therefore, even when the image display device 30 performs the wobbling process, the displacement amount ( The position indicated by the electronic pen 50 and the drawing position can be matched without notifying the electronic pen 50 and the drawing apparatus 40 of (δX, δY).

  In this embodiment, the voltage value applied to each electrode is, for example, voltage Vi1 = 150 (V), voltage Vi2 = 350 (V), voltage Vi4 = −175 (V), voltage Va = voltage Vay = voltage Vax. = −200 (V), voltage Vc = −50 (V), voltage Vs = voltage Vso = 205 (V), voltage Vr = 205 (V), voltage Ve = 155 (V), voltage Vd = voltage Vdy = voltage Vdx = 55 (V).

  However, these voltage values are only examples, and driving voltage waveforms applied to the respective electrodes of the panel shown in FIG. 11 are also examples. These drive voltage waveforms and voltage values are preferably set to optimal values as appropriate in accordance with the characteristics of the panel 10 and the specifications of the image display device 30.

  In the first embodiment and the second embodiment, horizontal lines are shown in which one discharge cell row is sequentially caused to emit light during the y coordinate detection period Py and is scanned from the upper end portion to the lower end portion of the display screen. However, the present invention is not limited to this. For example, a horizontal line for scanning by emitting the discharge cell rows sequentially by two rows may be displayed, or a horizontal line for scanning by emitting the discharge cell rows every other row may be displayed. Similarly, in the x-coordinate detection period Px, horizontal lines for sequentially emitting and scanning three discharge cell columns are shown. However, any number of discharge cell columns may be sequentially emitted, or a plurality of columns may be emitted. Every other discharge cell row may emit light. Thereby, the time required for the y-coordinate detection subfield SFy and the x-coordinate detection subfield SFx can be shortened.

  Note that each specific numerical value used in the embodiment is merely an example, and it is desirable to set an appropriate value appropriately according to the specifications of the electronic pen, the characteristics of the image display device, and the like.

  Even when a wobbling process is performed, the present invention can perform drawing with a natural feeling of use without causing a deviation between the position indicated by the electronic pen and the drawing position. It is useful as a display device and an image display system capable of drawing using an electronic pen.

DESCRIPTION OF SYMBOLS 10 Panel 12 Scan electrode 13 Sustain electrode 22 Data electrode 30 Image display apparatus 31 Image signal processing part 32 Data electrode drive part 33 Scan electrode drive part 34 Sustain electrode drive part 35 Control part 36 Wobbling part 40 Drawing apparatus 41 Receiving part 42 Drawing part DESCRIPTION OF SYMBOLS 43 Signal switching part 50 Electronic pen 51 Drawing switch 52 Light receiving element 53 Synchronization detection part 54 Coordinate calculation part 55 Transmission part 100 Image display system

Claims (3)

One field period is provided by a plurality of subfields including an image display subfield for inputting an image signal to display an image and a coordinate detection subfield for generating light emission for detecting coordinates on the image display surface. A driving method for a configured image display device, comprising:
The coordinate detection subfield includes a synchronization detection subfield for generating light emission for synchronization, a y-coordinate detection subfield for generating y-coordinate detection light emission for detecting a y-coordinate on the image display surface, and an image display An x-coordinate detection subfield for generating x-coordinate detection light emission for detecting an x-coordinate on the surface,
In the image display subfield, the display position of the image is moved and displayed by a predetermined displacement amount set depending on time, and displayed.
A driving method of an image display device, wherein the light emission timings of the y-coordinate detection light emission and the x-coordinate detection light emission are changed by a time corresponding to the displacement amount. One field in a plurality of subfields including a display device, an image display subfield for inputting an image signal to display an image, and a coordinate detection subfield for generating light emission for detecting coordinates on the image display surface A drive circuit configured to drive the display device by configuring a period,
The drive circuit is
Synchronous detection subfield for generating light emission for synchronization, y-coordinate detection subfield for generating y-coordinate detection light for detecting y-coordinate on the image display surface, and x-coordinate on the image display surface An x-coordinate detection subfield for generating x-coordinate detection light emission to form the coordinate detection subfield,
In the image display subfield, the display position of the image is moved and displayed by a predetermined displacement amount set depending on time, and displayed.
An image display device, wherein the light emission timings of the y-coordinate detection light emission and the x-coordinate detection light emission are changed for a time corresponding to the displacement amount. The image display device according to claim 2, an electronic pen that calculates coordinates of an image display surface indicated based on light emission of the coordinate detection subfield, and a drawing signal that is generated based on the coordinates calculated by the electronic pen to generate the image An image display system comprising: a drawing device that outputs to a display device.

Images