WO2014045520A1

WO2014045520A1 - Image display device, image display device driving method and image display system

Info

Publication number: WO2014045520A1
Application number: PCT/JP2013/005010
Authority: WO
Inventors: 貴彦折口; 裕也塩崎; 一朗坂田; 秀彦庄司
Original assignee: パナソニック株式会社
Priority date: 2012-09-18
Filing date: 2013-08-26
Publication date: 2014-03-27
Also published as: JP2015222278A

Abstract

The purpose of the present invention is to enable calculation of position coordinates even with an electronic pen that is at a distance from a plasma display panel. In order to do so, the following are generated: a proximate-use y-coordinate detection subfield that sequentially performs an operation for simultaneously applying y-coordinate detection pulses to a first number of scanning electrodes; a remote-use y-coordinate detection subfield that sequentially performs an operation for simultaneously applying y-coordinate detection pulses to a second number of scanning electrodes; a proximate-use x-coordinate detection subfield that sequentially performs an operation for simultaneously applying x-coordinate detection pulses to a third number of data electrodes; and a remote-use x-coordinate detection subfield that sequentially performs an operation for simultaneously applying x-coordinate detection pulses to a fourth number of data electrodes. Further, the second number of scanning electrodes is made to have a numerical value greater than that of the first, and the fourth number of data electrodes is made to have a numerical value greater than that of the third.

Description

Image display device, image display device driving method, and image display system

The present disclosure relates to an image display device that can input characters and drawings on an image display surface using an electronic pen, a driving method of the image display device, and an image display system.

There is an image display device that has a function of allowing handwriting input of characters and drawings on the image display surface using a pen-type pointing device called “electronic pen”. In such an image display device, a technique for detecting the position of the electronic pen in the image display region is used. Hereinafter, the coordinates representing the position of the electronic pen in the image display area are referred to as “position coordinates”.

For example, in Patent Document 1, a position coordinate detection period is provided in one field, and light emission generated in a plasma display panel (hereinafter referred to as “panel”) in the position coordinate detection period is detected by an optical sensor built in the electronic pen. Thus, an apparatus and a method for detecting the coordinate position of an electronic pen are disclosed.

In an image display device using this technology, an electronic pen is used in contact with or close to the image display surface in order to detect light emission generated on the image display surface with an optical sensor.

JP 2001-318765 A

The driving method of the image display device according to the present disclosure is a driving method of an image display device including a plasma display panel in which discharge cells are formed at intersections of scan electrodes, sustain electrodes, and data electrodes. In this driving method, an image display subfield for displaying an image on the plasma display panel and an operation of simultaneously applying a y-coordinate detection pulse to the first number of scanning electrodes while applying a y-coordinate detection voltage to the data electrodes are sequentially performed. A proximity y-coordinate detection subfield to be performed, and a remote y-coordinate detection subfield to sequentially apply the y-coordinate detection pulse to the second number of scan electrodes while applying the y-coordinate detection voltage to the data electrode. An x coordinate detection subfield for proximity that sequentially applies an x coordinate detection pulse to the third number of data electrodes while applying an x coordinate detection voltage to the scan electrodes, and an x coordinate detection voltage to the scan electrodes. A remote x-coordinate detection subfield for sequentially performing an operation of simultaneously applying an x-coordinate detection pulse to the fourth number of data electrodes while being applied is generated. Then, the second number is set to a numerical value larger than the first number, and the fourth number is set to a numerical value larger than the third number.

An image display apparatus according to the present disclosure drives a plasma display panel in which discharge cells are formed at intersections of scan electrodes, sustain electrodes, and data electrodes, and one field is composed of a plurality of subfields. And a drive circuit. In this image display device, the drive circuit simultaneously applies an y-coordinate detection pulse to the first number of scan electrodes while applying the y-coordinate detection voltage to the data display electrode and the data display subfield for displaying an image on the plasma display panel. Proximity y-coordinate detection subfield for sequentially applying the application, and remote y for sequentially applying the y-coordinate detection pulse to the second number of scanning electrodes while applying the y-coordinate detection voltage to the data electrodes The coordinate detection subfield, the proximity x coordinate detection subfield that sequentially applies the x coordinate detection pulse to the third number of data electrodes while the x coordinate detection voltage is applied to the scan electrodes, and the scan electrode A remote x-coordinate detection sub-field that sequentially applies an x-coordinate detection pulse to the fourth number of data electrodes while applying the x-coordinate detection voltage. To generate and soil. Then, the second number is set to a numerical value larger than the first number, and the fourth number is set to a numerical value larger than the third number.

An image display system according to the present disclosure includes: a plasma display panel in which discharge cells are formed at intersections of scan electrodes, sustain electrodes, and data electrodes; an image display device including a drive circuit that drives the plasma display panel; A pen and a drawing device are provided. The drive circuit sequentially performs an operation of applying a y-coordinate detection pulse to the first number of scanning electrodes simultaneously while applying a y-coordinate detection voltage to the data electrode and an image display subfield for displaying an image on the plasma display panel. A proximity y-coordinate detection subfield, a remote y-coordinate detection subfield that sequentially applies an y-coordinate detection pulse to the second number of scan electrodes while applying a y-coordinate detection voltage to the data electrodes, Proximity x-coordinate detection subfield for sequentially applying an x-coordinate detection pulse to the third number of data electrodes while applying the x-coordinate detection voltage to the scan electrodes, and applying the x-coordinate detection voltage to the scan electrodes And generating a remote x-coordinate detection subfield for sequentially performing an operation of simultaneously applying an x-coordinate detection pulse to the fourth number of data electrodes, and setting the second number to And sets the number greater than the number of 1 to set the fourth number of the number greater than the third number. The electronic pen receives a light emitted from the plasma display panel and outputs a light reception signal, a proximity y coordinate detection subfield, a proximity x coordinate detection subfield, a remote y coordinate detection subfield, and a remote x coordinate A synchronization detection unit that generates a coordinate reference signal synchronized with the detection subfield based on the light reception signal, a coordinate calculation unit that calculates a coordinate on the plasma display panel pointed to by the electronic pen based on the coordinate reference signal and the light reception signal, and a coordinate calculation unit And a transmitter that transmits the calculated coordinates to the drawing apparatus. The drawing apparatus includes a receiving unit that receives coordinates transmitted from the electronic pen, and a drawing unit that generates a drawing signal based on the coordinates received by the receiving unit and outputs the drawing signal to the image display device.

FIG. 1 is an exploded perspective view illustrating an example of a structure of a panel used in the image display device according to the first embodiment of the present disclosure. FIG. 2 is a diagram illustrating an example of the electrode arrangement of the panel used in the image display device according to the first embodiment of the present disclosure. FIG. 3 is a diagram schematically illustrating an example of a drive voltage waveform applied to each electrode of the panel in the image display subfield according to the first embodiment of the present disclosure. FIG. 4 is a diagram schematically illustrating an example of a drive voltage waveform applied to each electrode of the panel in the coordinate detection subfield according to the first embodiment of the present disclosure. FIG. 5 is a diagram schematically illustrating a configuration example of the image display system according to the first embodiment of the present disclosure. FIG. 6 is a circuit diagram schematically illustrating a configuration example of the sustain electrode driving unit of the image display device according to the first embodiment of the present disclosure. FIG. 7 is a circuit diagram schematically illustrating a configuration example of the data electrode driving unit of the image display device according to the first embodiment of the present disclosure. FIG. 8 is a circuit diagram schematically illustrating a configuration example of the scan electrode driving unit of the image display apparatus according to the first embodiment of the present disclosure. FIG. 9 is a diagram schematically illustrating an example of the position coordinate detection operation when the electronic pen is used in the proximity in the image display system according to the first embodiment of the present disclosure. FIG. 10 is a diagram schematically illustrating an example of a position coordinate detection operation when the electronic pen is used remotely in the image display system according to the first embodiment of the present disclosure. FIG. 11 is a diagram schematically illustrating an example of an operation when the electronic pen is used in the proximity in the image display system according to the first embodiment of the present disclosure. FIG. 12 is a diagram schematically illustrating an example of an operation when the electronic pen is used remotely in the image display system according to the first embodiment of the present disclosure. FIG. 13 is a diagram schematically illustrating an example of an operation when performing handwriting input with the electronic pen in the image display system according to the first embodiment of the present disclosure. FIG. 14 is a diagram schematically illustrating an example of a drive voltage waveform applied to each electrode of the panel in the coordinate detection sub-field according to the second embodiment of the present disclosure.

Hereinafter, an image display system according to an embodiment of the present disclosure will be described with reference to the drawings. In the following embodiments, an image display system having an image display device using a plasma display panel as an image display unit will be described as an example.

(Embodiment 1)
FIG. 1 is an exploded perspective view illustrating an example of the structure of the panel 10 used in the image display device according to the first embodiment of the present disclosure.

A plurality of display electrode pairs 14 each including a scanning electrode 12 and a sustain electrode 13 are formed on a glass front substrate 11, a dielectric layer 15 is formed thereon, and a protective layer 16 is further formed thereon. . The front substrate 11 serves as an image display surface on which an image is displayed.

A plurality of data electrodes 22 are formed on the rear substrate 21, a dielectric layer 23 is formed thereon, and a grid-like partition wall 24 is further formed thereon. On the side surface of the partition wall 24 and the surface of the dielectric layer 23, a phosphor layer 25R that emits red (R), a phosphor layer 25G that emits green (G), and a phosphor layer 25B that emits blue (B). Is provided. Hereinafter, the phosphor layer 25R, the phosphor layer 25G, and the phosphor layer 25B are also referred to as a phosphor layer 25.

Then, 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 each other with the discharge space interposed therebetween, and a discharge gas is sealed in the discharge space.

FIG. 2 is a diagram illustrating an example of an electrode arrangement of the panel 10 used in the image display device according to the first embodiment of the present disclosure.

In the 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) extended in the first direction are arranged. The m data electrodes D1 to Dm (data electrode 22 in FIG. 1) extended in the second direction intersecting the first direction are arranged.

Hereinafter, the first direction is referred to as a row direction (or horizontal direction, line direction, or x coordinate direction), and the second direction is referred to as a column direction (or vertical direction or y coordinate direction).

In panel 10, one discharge cell is formed in a region where one pair of scan electrode SCi (i = 1 to n) and sustain electrode SUi intersects with one data electrode Dj (j = 1 to m). A set of three discharge cells emitting red, green, and blue colors adjacent to each other constitutes one pixel. Accordingly, m discharge cells (m / 3 pixels) are formed on one pair of display electrodes 14, and n discharge cells are formed on one data electrode 22. An area where m × n discharge cells are formed becomes an image display area of the panel 10.

Next, driving voltage waveforms generated in the image display apparatus according to the present embodiment will be described with reference to FIGS.

In the present embodiment, a plurality of image display subfields (shown in FIG. 3) for displaying an image on the image display unit and a plurality of coordinate detections for detecting “position coordinates” of the electronic pen in one field. Subfield (shown in FIG. 4).

FIG. 3 is a diagram schematically illustrating an example of a drive voltage waveform applied to each electrode of the panel 10 in the image display subfield according to the first embodiment of the present disclosure.

Each image display subfield has an initialization period, an address period, and a sustain period. Hereinafter, the image display subfield is also simply referred to as a subfield.

For the initialization operation in the initialization period, a “forced initialization operation” that forcibly generates an initialization discharge in the discharge cells and a discharge cell that generates an address discharge in the address period of the immediately preceding subfield are selectively used. There is a “selective initialization operation” that generates an initialization discharge. In the present embodiment, an example in which a forced initialization operation is performed in subfield SF1 and a selective initialization operation is performed in subfields SF2 to SF8 is shown.

The number of image display subfields in one field is, for example, eight (subfields SF1 to SF8), and the luminance weight of each subfield is, for example, (1, 34, 21, 13, 8, 5, 3, 2). is there. However, the number of subfields, the luminance weight, etc. are not limited to the above numerical values.

In the initializing period Pi1 of the subfield SF1 in which the forced initializing operation is performed, the voltage 0 (V) is applied to each of the data electrodes D1 to Dm and the sustain electrodes SU1 to SUn. After applying voltage 0 (V) to scan electrodes SC1 to SCn, an upward ramp waveform voltage that gradually rises from voltage Vi1 lower than the discharge start voltage to voltage Vi2 exceeding the discharge start voltage is applied. Next, positive voltage Ve is applied to sustain electrodes SU1 to SUn, and gradually decreases from voltage 0 (V), which is less than the discharge start voltage, to negative voltage Vi4, which exceeds the discharge start voltage, for scan electrodes SC1 to SCn. Apply a falling ramp waveform voltage.

The initializing discharge is generated in each discharge cell by this forced initializing operation, and the wall voltage on each electrode is adjusted to a voltage suitable for the address operation in the subsequent address period Pw1. Hereinafter, the driving voltage waveform generated in the initialization period Pi1 is referred to as a forced initialization waveform.

Note that the discharge cells to which the forced initializing waveform is applied in the initializing period in which the forced initializing operation is performed may be all the discharge cells in the image display area of the panel 10, but for example, in the image display area Some discharge cells may be used. The same applies to all initialization periods in which the forced initialization operation in the following description is performed.

In the address period Pw1 of the subfield SF1, a negative scan pulse having a negative voltage Va is applied to the scan electrode SC1 in the first row, and data of discharge cells to be emitted in the first row of the data electrodes D1 to Dm. An address operation is performed in which a positive address pulse with a positive voltage Vd is applied to the electrode Dk.

The same addressing operation is sequentially performed in the order of scan electrodes SC2, SC3, SC4,..., SCn up to the discharge cell in the nth row.

In the sustain period Ps1 of the subfield SF1, the number of sustain pulses obtained by multiplying the brightness weight by a predetermined brightness multiple is alternately applied to the scan electrodes SC1 to SCn and the sustain electrodes SU1 to SUn. A discharge cell that has generated an address discharge in the immediately preceding address period Pw1 generates a number of sustain discharges corresponding to the luminance weight, and emits light at a luminance corresponding to the luminance weight.

After the sustain pulse is generated (after the sustain operation is completed in sustain period Ps1), voltage 0 (V) is applied to sustain electrodes SU1 to SUn and data electrodes D1 to Dm while voltage 0 is applied to scan electrodes SC1 to SCn. An erasing operation is performed in which an upward ramp waveform voltage that gradually rises from (V) to the positive voltage Vr is applied.

As a result, a weak discharge (erase discharge) is generated in the discharge cell that has generated the sustain discharge, and unnecessary wall charges in the discharge cell are erased.

In the initialization period Pi2 of the subfield SF2 in which the selective initialization operation is performed, the voltage 0 (V) is applied to the data electrodes D1 to Dm, and the positive voltage Ve is applied to the sustain electrodes SU1 to SUn. A downward ramp waveform voltage falling from voltage 0 (V), which is less than the discharge start voltage, to negative voltage Vi4 is applied to scan electrodes SC1 to SCn.

By this selective initializing operation, a weak initializing discharge is generated in the discharge cell that has generated the sustain discharge in the sustain period Ps1 of the immediately preceding subfield SF1, and the wall voltage on each electrode is changed to the address operation in the subsequent address period Pw2. The wall voltage is adjusted to a suitable level. In the discharge cells that did not generate the sustain discharge in the sustain period Ps1, the initialization discharge does not occur. Hereinafter, the drive voltage waveform generated in the initialization period Pi2 is referred to as a selective initialization waveform.

In the subsequent address period Pw2 and sustain period Ps2, drive voltage waveforms similar to those in the address period Pw1 and sustain period Ps1 are applied to each electrode, except for the number of sustain pulses.

In each subfield after subfield SF3, the same drive voltage waveform as in subfield SF2 is applied to each electrode except for the number of sustain pulses.

Next, the drive voltage waveform generated in the coordinate detection subfield will be described with reference to FIG.

FIG. 4 is a diagram schematically illustrating an example of a drive voltage waveform applied to each electrode of the panel 10 in the coordinate detection subfield according to the first embodiment of the present disclosure. In the present embodiment, the coordinate detection subfield includes a synchronization detection subfield SFo, a proximity y coordinate detection subfield SFy1, a proximity x coordinate detection subfield SFx1, a remote y coordinate detection subfield SFy2, and a remote x. A coordinate detection subfield SFx2 is included.

Hereinafter, the proximity y coordinate detection subfield SFy1 and the remote y coordinate detection subfield SFy2 are collectively referred to as “y coordinate detection subfield SFy”, and the proximity x coordinate detection subfield SFx1 and the remote x coordinate detection are performed. The subfield SFx2 is collectively referred to as “x coordinate detection subfield SFx”.

The position pointed to by the electronic pen in the image display area (hereinafter also referred to as “position of the electronic pen”) is represented by an x coordinate and ay coordinate. In this embodiment, the coordinate in the row direction is the x coordinate, and the coordinate in the column direction is the y coordinate. The x coordinate detection subfield SFx and the y coordinate detection subfield SFy are subfields for detecting the x coordinate and the y coordinate, and display the x coordinate detection pattern and the y coordinate detection pattern on the panel 10.

The proximity y-coordinate detection subfield SFy1 and the proximity x-coordinate detection subfield SFx1 are used when the user directly contacts the front end of the electronic pen with the panel 10 (or at a position relatively close to the panel 10). This is a sub-field used for detecting the position coordinates of the electronic pen at the time of “use near”. The remote y-coordinate detection subfield SFy2 and the remote x-coordinate detection subfield SFx2 are sub-fields used for detecting the position coordinates of the electronic pen when the user uses the electronic pen at a position away from the panel 10 during "remote use". It is a field.

The electronic pen is provided in the image display system of the present embodiment, and is used when a user inputs characters and drawings on the panel 10 by handwriting. Details of the electronic pen will be described later. Further, the position (positional coordinate) pointed to by the electronic pen is a light receiving element of the electronic pen described later displayed by light emission of the x-coordinate detection pattern displayed in the x-coordinate detection subfield SFx and the y-coordinate detection subfield SFy. It is a position in the image display surface that receives light emitted from the y coordinate detection pattern.

Further, in the image display system in the present embodiment, wireless communication is performed between the electronic pen and a drawing apparatus described later. The electronic pen calculates the position coordinates of the electronic pen inside the electronic pen, and transmits data of the calculated position coordinates from the electronic pen to the drawing apparatus by wireless communication.

The synchronization detection subfield SFo is a subfield for the electronic pen to accurately grasp the timing at which the coordinate detection subfield is generated in the image display device. The electronic pen receives light emitted in the synchronization detection subfield SFo to generate a signal (coordinate reference signal) serving as a reference for calculating position coordinates with high accuracy by synchronizing with the image display device. It becomes possible.

Note that the generation order of each subfield is not limited to the order shown in the present embodiment. Further, the coordinate detection subfield is not necessarily provided in each field.

The synchronization detection subfield SFo in FIG. 4 has an initialization period Pio, a writing period Pwo, and a synchronization detection period Po.

In the initialization period Pio, the selection initialization operation similar to the initialization period Pi2 of the subfield SF2 of the image display subfield is performed, and thus the description thereof is omitted.

In the address period Pwo of the synchronization detection subfield SFo, 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.

Next, an address pulse of voltage Vd is applied to data electrodes D1 to Dm, and a scan pulse of voltage Va is applied to scan electrodes SC1 to SCn at time to0 to generate an address discharge in each discharge cell.

In the address period Pwo shown in FIG. 4, a scan pulse is applied simultaneously to all the scan electrodes SC1 to SCn to generate address discharges in all the discharge cells at the same time. For example, the data electrodes D1 to Dm Alternatively, the address pulse may be applied to each electrode from scan electrode SC1 to scan electrode SCn, and the address discharge may be sequentially generated in each discharge cell.

After the write operation is completed, voltage 0 (V) is applied to the data electrodes D1 to Dm. Further, voltage Vc is applied to scan electrodes SC1 to SCn, and then voltage 0 (V) is applied. In this embodiment, this state is maintained until time to1. During this period, after the address discharge is generated in the discharge cell, the state in which no discharge is generated is maintained.

Next, in the synchronization detection period Po of the synchronization detection subfield SFo, the panel 10 is caused to emit a plurality of times of light emission (light emission for synchronization detection) as a reference when calculating the position coordinates in the electronic pen.

In the example shown in FIG. 4, at time to1 after time To0 has elapsed from time to0, voltage 0 (V) is applied to sustain electrodes SU1 to SUn and synchronous detection pulse V1 of voltage Vso is applied to scan electrodes SC1 to SCn. Apply. Next, at time to2 after time To1 has elapsed from time to1, voltage 0 (V) is applied to scan electrodes SC1 to SCn, and synchronous detection pulse V2 of voltage Vso is applied to sustain electrodes SU1 to SUn. Next, at time to3 after time To2 has elapsed from time to2, voltage 0 (V) is applied to sustain electrodes SU1 to SUn, and synchronous detection pulse V3 of voltage Vso is applied to scan electrodes SC1 to SCn. Next, at time to4 after time To3 has elapsed from time to3, voltage 0 (V) is applied to scan electrodes SC1 to SCn, and synchronous detection pulse V4 of voltage Vso is applied to sustain electrodes SU1 to SUn.

As a result, four synchronous detection discharges are generated in all the discharge cells in the image display area of the panel 10, and light emission for synchronous detection is generated four times in the panel 10.

As described above, in the synchronization detection subfield SFo, the synchronization detection discharge is applied to all the discharge cells in the image display area of the panel 10 at predetermined time intervals (for example, time To1, time To2, and time To3). Is generated a plurality of times (for example, four times), and light emission for synchronization detection is generated a plurality of times (for example, four times).

The synchronous detection discharge is a discharge similar to the sustain discharge, and is a stronger discharge than the address discharge, and has higher luminance than the light emission generated in the address period Pwo.

Then, the electronic pen receives a plurality of times (for example, four times) of light emission for synchronization detection generated at predetermined time intervals (for example, time To1, time To2, and time To3) and receives the coordinate reference signal. Create The coordinate reference signal is a signal that serves as a reference when calculating the position coordinate (x, y) of the electronic pen.

In the synchronization detection subfield SFo, the entire surface of the image display surface of the panel 10 shines simultaneously at the same timing, so the electronic pen emits this light regardless of the position of the position of the electronic pen in the image display area of the panel 10. Can be received at the same timing.

In the present embodiment, the time To0 is set to a time longer than any of the time To1, the time To2, and the time To3. This is to prevent the electronic pen from erroneously recognizing the light emission due to the address discharge generated in the address period Pwo of the synchronization detection subfield SFo as the light emission due to another discharge. In the present embodiment, for example, the time To0 is about 50 μsec, the time To1 is about 40 μsec, the time To2 is about 20 μsec, and the time To3 is about 30 μsec. However, each time is not limited to these numerical values, and may be set appropriately according to the specifications of the image display system.

In the synchronization detection period Po of the synchronization detection subfield SFo, after the generation of the synchronization detection pulse V4 (at the end of the synchronization detection period Po), an erase operation similar to the erase operation performed at the end of the sustain period Ps1 of the subfield SF1 is performed. . As a result, a weak erasing discharge is generated in the discharge cell that has generated the synchronous detection discharge immediately before.

Subsequently, the proximity y-coordinate detection subfield SFy1 is generated.

Hereinafter, an aggregate of discharge cells constituting one row is referred to as “discharge cell row”, and an aggregate of pixels constituting one row is referred to as “pixel row”. In the present embodiment, the discharge cell row and the pixel row are substantially the same. A group of discharge cells constituting one column is referred to as a “discharge cell column”, and a group of discharge cells (pixel column) composed of three adjacent discharge cell columns is referred to as a “pixel column”. .

The proximity y-coordinate detection subfield SFy1 has an initialization period Piy, a y-coordinate detection period Py1, and an erasing period Pey.

In the initialization period Piy, the same selective initialization operation as in the initialization period Pi2 of the subfield SF2 of the image display subfield is performed to generate an initialization discharge in each discharge cell. Thus, the wall voltage of each discharge cell is adjusted to a wall voltage suitable for the proximity y coordinate detection pattern display operation in the subsequent y coordinate detection period Py1.

In the subsequent y-coordinate detection period Py1, the operation of simultaneously applying the y-coordinate detection pulse to the “first number” scanning electrodes 12 while applying the y-coordinate detection voltage Vdy to the data electrodes D1 to Dm, This is sequentially performed on scan electrodes SC1 to SCn. In this embodiment, an example in which the “first number” is “1” is shown, but the “first number” may be two or more.

In the y coordinate detection period Py1 starting at time ty01, 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. To do.

After time Ty01 has elapsed from time ty01, positive y-coordinate detection voltage Vdy is applied to data electrodes D1 to Dm, and negative y-coordinate detection pulse of voltage Vay is applied to scan electrode SC1 constituting the first pixel row. Apply. This first pixel row is, for example, a pixel row arranged at the upper end of the image display area.

In the discharge cell at the intersection of the data electrodes D1 to Dm to which the y-coordinate detection voltage Vdy is applied and the scan electrode SC1 to which the y-coordinate detection pulse of the voltage Vay is applied, discharges are generated all at once. In this way, discharge occurs in the first pixel row, and the first pixel row emits light. Hereinafter, this discharge is also referred to as “y-coordinate detection discharge”. The light emission by this y-coordinate detection discharge becomes light emission for y-coordinate detection when the electronic pen is used in proximity.

The same operation is performed until the nth discharge cell row is reached in the order of scan electrode SC2, scan electrode SC3,..., Scan electrode SCn with the y coordinate detection voltage Vdy applied to data electrodes D1 to Dm. Do it sequentially. As a result, the y coordinate detection discharge is sequentially generated in each pixel row from the uppermost pixel row (first pixel row) to the lowermost pixel row (nth pixel row) of the panel 10 one pixel row at a time. .

Thus, in the y-coordinate detection period Py1 of the proximity y-coordinate detection subfield SFy1, one horizontal line that emits light with a width corresponding to the “first number” (for example, one pixel row) is the image display area of the panel 10. A light emission pattern that sequentially moves (for example, one pixel row at a time) from the upper end portion (first pixel row) to the lower end portion (nth pixel row) is displayed on the panel 10.

Hereinafter, this light emission pattern is referred to as “proximity y coordinate detection pattern”. Further, one light emitting line having a width corresponding to the “first number” is referred to as “first light emitting line”. For example, if the “first number” is 2, the “proximity y coordinate detection pattern” is a light emission pattern in which the “first light emission line” having a width of two pixel rows sequentially moves in the y coordinate direction by two pixel rows. It becomes.

In the y-coordinate detection period Py1, by displaying the proximity y-coordinate detection pattern on the panel 10, the timing at which the electronic pen receives light emitted from the first light emission line changes according to the position coordinates of the electronic pen. Therefore, the y coordinate of the position coordinates (x, y) when the electronic pen is used in proximity can be detected by detecting the timing at which the light emission of the first light emission line is received by the electronic pen.

In the present embodiment, as shown in FIG. 4, the time during which the voltage Vay of the y coordinate detection pulse is applied to each of the scan electrodes SC1 to SCn in the y coordinate detection period Py1 (or the pulse width of the y coordinate detection pulse). ) Is Ty11. This Ty11 is, for example, about 1 μsec.

In the erasing period Pey of the proximity y coordinate detection subfield SFy1, an erasing operation similar to the erasing operation performed at the end of the sustain period Ps1 of the subfield SF1 is performed. As a result, a weak erase discharge is generated in the discharge cell that has generated the y-coordinate detection discharge.

The subsequent proximity x-coordinate detection subfield SFx1 has an initialization period Pix, an x-coordinate detection period Px1, and an erasing period Pex.

In the initialization period Pix, while the voltage 0 (V) is applied to the sustain electrodes SU1 to SUn, the selective initialization operation similar to the initialization period Piy of the proximity y coordinate detection subfield SFy1 is performed, and each discharge cell is initialized. Generates a discharge. As a result, the wall voltage of each discharge cell is adjusted to a wall voltage suitable for the proximity x-coordinate detection pattern display operation in the subsequent x-coordinate detection period Px1.

In the subsequent x-coordinate detection period Px1 of the proximity x-coordinate detection subfield SFx1, the x-coordinate detection voltage Vax is applied to the scan electrodes SC1 to SCn, and x is simultaneously applied to the preset “third number” of data electrodes 22. The operation of applying the coordinate detection pulse is sequentially performed on the data electrodes D1 to Dm. In the present embodiment, an example in which the “third number” is “3” is shown, but the “third number” may be a number other than three.

In the x coordinate detection period Px1 starting at time tx01, 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 negative x coordinate is applied to the scan electrodes SC1 to SCn. A detection voltage Vax is applied.

After time Tx01 has elapsed from time tx01, positive x of voltage Vdx is applied to data electrodes D1 to D3 constituting the first pixel column while negative x coordinate detection voltage Vax is applied to scan electrodes SC1 to SCn. Coordinate detection pulses are applied simultaneously. The first pixel column is, for example, a pixel column arranged at the left end of the image display area.

In the discharge cells at the intersections of the data electrodes D1 to D3 to which the x-coordinate detection pulse of the voltage Vdx is applied and the scan electrodes SC1 to SCn to which the x-coordinate detection voltage Vax is applied, discharge is generated all at once. Thus, discharge occurs in the first pixel column, and the first pixel column emits light. Hereinafter, this discharge is also referred to as “x coordinate detection discharge”. The light emission by the x coordinate detection discharge is light emission for x coordinate detection when the electronic pen is used in proximity.

Similar operations are performed adjacent to each other in the order of data electrodes D4 to D6, data electrodes D7 to D9,..., Data electrodes Dm-2 to Dm, with the x coordinate detection voltage Vax applied to scan electrodes SC1 to SCn. The three data electrodes 22 are sequentially performed until reaching the m-th discharge cell column. Thereby, the x coordinate detection discharge is sequentially performed on each pixel column from the leftmost pixel column (first pixel column) to the rightmost pixel column (m / 3 pixel column) of the panel 10 one pixel column at a time. appear.

Thus, in the x-coordinate detection period Px1 of the proximity x-coordinate detection subfield SFx1, one vertical line that emits light with a width corresponding to the “third number” (for example, one pixel column) is displayed on the panel 10. A light emission pattern that sequentially moves (for example, one pixel column at a time) from the left end portion (first pixel column) of the region to the right end portion (m / 3 pixel column) is displayed on the panel 10.

Hereinafter, this light emission pattern is referred to as “proximity x coordinate detection pattern”. In addition, one light emitting line having a width corresponding to the “third number” is referred to as a “second light emitting line”. For example, if the “third number” is 6, the “proximity x coordinate detection pattern” is a light emission pattern in which the “second light emission line” having a width of two pixel columns sequentially moves in the x coordinate direction by two pixel columns. It becomes.

In the x-coordinate detection period Px1, by displaying the proximity x-coordinate detection pattern on the panel 10, the timing at which the electronic pen receives light emitted from the second light emission line changes according to the position coordinates of the electronic pen. Therefore, the x coordinate of the position coordinate (x, y) when the electronic pen is used in proximity can be detected by detecting the timing at which the electronic pen receives the light emitted from the second light emitting line.

In the present embodiment, as shown in FIG. 4, the time (or the pulse width of the x coordinate detection pulse) during which the voltage Vdx of the x coordinate detection pulse is applied to each of the data electrodes D1 to Dm in the x coordinate detection period Px1. ) Is Tx11. This Tx11 is, for example, about 1 μsec.

In the erasing period Pex of the proximity x-coordinate detection subfield SFx1, an erasing operation similar to the erasing operation performed at the end of the sustaining period Ps1 of the subfield SF1 is performed. As a result, a weak erase discharge is generated in the discharge cell that has generated the x-coordinate detection discharge.

Subsequently, the remote y-coordinate detection subfield SFy2 is generated.

The remote y-coordinate detection subfield SFy2 has an initialization period Piy, a y-coordinate detection period Py2, and an erasing period Pey.

In the initializing period Piy, the selective initializing operation similar to the initializing period Piy of the proximity y coordinate detection subfield SFy1 is performed to generate an initializing discharge in each discharge cell. Thereby, the wall voltage of each discharge cell is adjusted to the wall voltage suitable for the remote y coordinate detection pattern display operation in the subsequent y coordinate detection period Py2.

In the subsequent y-coordinate detection period Py2 of the remote y-coordinate detection subfield SFy2, the y-coordinate detection voltage Vdy is applied to the data electrodes D1 to Dm, and y is simultaneously applied to the preset “second number” of scan electrodes 12. The operation of applying the coordinate detection pulse is sequentially performed on scan electrodes SC1 to SCn. The “second number” is a numerical value larger than the “first number” used in the y coordinate detection period Py1 of the proximity y coordinate detection subfield SFy1, and in the present embodiment, the “second number” is “ Although an example of “8” is shown, the “second number” may be a number other than 8.

In the y coordinate detection period Py2 starting at time ty02, 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. To do.

After time Ty02 has elapsed from time ty02, positive y-coordinate detection voltage Vdy is applied to data electrodes D1 to Dm, and negative voltage Vay is applied to scan electrodes SC1 to SC8 constituting the first to eighth pixel rows. A y-coordinate detection pulse is applied simultaneously.

In the discharge cells at the intersections of the data electrodes D1 to Dm to which the y-coordinate detection voltage Vdy is applied and the scan electrodes SC1 to SC8 to which the y-coordinate detection pulse of the voltage Vay is applied, discharge is generated all at once. In this way, discharge is generated simultaneously in the 1st to 8th pixel rows, and 8 pixel rows in the 1st to 8th rows emit light all at once. Hereinafter, this discharge is also referred to as “y-coordinate detection discharge”. The light emission by this y-coordinate detection discharge is light emission for y-coordinate detection when the electronic pen is used remotely.

Similar operations are performed adjacent to each other in the order of scan electrodes SC9 to SC16, scan electrodes SC17 to SC24,..., Scan electrodes SCn-7 to SCn with the y coordinate detection voltage Vdy applied to the data electrodes D1 to Dm. For every eight scanning electrodes 12 to be performed, the steps are sequentially performed until the nth discharge cell row is reached. As a result, the y coordinate detection discharge is sequentially generated in each of the pixel rows from the uppermost pixel row (first pixel row) to the lowermost pixel row (nth pixel row) of the panel 10 by 8 pixel rows. .

Thus, in the y-coordinate detection period Py2 of the remote y-coordinate detection subfield SFy2, one horizontal line that emits light with a width corresponding to the “second number” (for example, 8 pixel rows) is the image display area of the panel 10. A light emission pattern that sequentially moves (for example, every 8 pixel rows) from the upper end portion (first pixel row) to the lower end portion (nth pixel row) is displayed on the panel 10.

Hereinafter, this light emission pattern is referred to as a “remote y coordinate detection pattern”. In addition, one light emitting line having a width corresponding to the “second number” is referred to as a “third light emitting line”. For example, if the “second number” is 16, the “remote y coordinate detection pattern” is a light emission pattern in which the “third light emission line” having a width of 16 pixel rows sequentially moves in the y coordinate direction by 16 pixel rows. It becomes.

The third light emitting line is a light emitting line having a wider width and a larger light emission amount than the first light emitting line for proximity described above. Therefore, the distance to the panel 10 where the electronic pen can receive the light emitted from the third light emitting line is larger than the distance that the light emitted from the first light emitting line can be received.

In the y coordinate detection period Py2, by displaying the remote y coordinate detection pattern on the panel 10, the timing at which the electronic pen receives the light emitted from the third light emission line changes according to the position coordinates of the electronic pen. Therefore, the y coordinate of the position coordinate (x, y) when the electronic pen is used remotely can be detected by detecting the timing at which the electronic pen emits the light emitted from the third light emitting line.

In the present embodiment, as shown in FIG. 4, the time (or the pulse width of the y coordinate detection pulse) during which the voltage Vay of the y coordinate detection pulse is applied to each of the scan electrodes SC1 to SCn in the y coordinate detection period Py2. ) Is Ty12. This Ty12 is, for example, about 1 μsec.

In the erase period Pey of the remote y coordinate detection subfield SFy2, the same erase operation as the erase operation performed in the erase period Pey of the proximity y coordinate detection subfield SFy1 is performed. As a result, a weak erase discharge is generated in the discharge cell that has generated the y-coordinate detection discharge.

The subsequent remote x-coordinate detection subfield SFx2 has an initialization period Pix, an x-coordinate detection period Px2, and an erasing period Pex.

In the initialization period Pix, a selective initialization operation similar to that in the initialization period Pix of the proximity x coordinate detection subfield SFx1 is performed to generate an initialization discharge in each discharge cell. Thereby, the wall voltage of each discharge cell is adjusted to a wall voltage suitable for the remote x-coordinate detection pattern display operation in the subsequent x-coordinate detection period Px2.

In the subsequent x-coordinate detection period Px2 of the remote x-coordinate detection subfield SFx2, the x-coordinate detection voltage Vax is applied to the scan electrodes SC1 to SCn, and x is simultaneously applied to the “fourth” data electrode 22 set in advance. The operation of applying the coordinate detection pulse is sequentially performed on the data electrodes D1 to Dm. The “fourth number” is a numerical value larger than the “third number” used in the x coordinate detection period Px1 of the proximity x coordinate detection subfield SFx1, and in the present embodiment, the “fourth number” is “ Although an example of “24” is shown, the “fourth number” may be a number other than 24.

In the x coordinate detection period Px2 starting at time tx02, 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 negative x coordinate is applied to the scan electrodes SC1 to SCn. A detection voltage Vax is applied.

After the time Tx02 has elapsed from time tx02, the positive polarity of the voltage Vdx is applied to the data electrodes D1 to D24 constituting the first to eighth pixel columns while the negative x coordinate detection voltage Vax is applied to the scan electrodes SC1 to SCn. X-coordinate detection pulses are simultaneously applied.

In the discharge cells at the intersections of the data electrodes D1 to D24 to which the x-coordinate detection pulse of the voltage Vdx is applied and the scan electrodes SC1 to SCn to which the x-coordinate detection voltage Vax is applied, discharge is generated all at once. In this way, discharge is generated simultaneously in the first to eighth pixel columns, and the first to eighth pixel columns emit light all at once. Hereinafter, this discharge is also referred to as “x coordinate detection discharge”. The light emission by the x coordinate detection discharge is light emission for x coordinate detection when the electronic pen is used remotely.

Similar operations are performed adjacent to each other in the order of data electrodes D25 to D48, data electrodes D49 to D72,..., Data electrodes Dm-23 to Dm, with the x coordinate detection voltage Vax applied to scan electrodes SC1 to SCn. For every 24 data electrodes 22, the process is sequentially performed until the mth discharge cell row is reached. As a result, the x coordinate detection discharge is sequentially applied to each pixel column from the leftmost pixel column (first pixel column) to the rightmost pixel column (m / 3 pixel column) of the panel 10 by eight pixel columns. appear.

In this way, in the x-coordinate detection period Px2 of the remote x-coordinate detection subfield SFx2, one vertical line that emits light with a width corresponding to the “fourth number” (for example, 8 pixel columns) is displayed on the panel 10. A light emission pattern that sequentially moves (for example, by 8 pixel columns) from the left end portion (first pixel row) to the right end portion (m / 3 pixel row) of the region is displayed on the panel 10.

Hereinafter, this light emission pattern is referred to as “remote x coordinate detection pattern”. In addition, one light emitting line having a width corresponding to the “fourth number” generated in the y coordinate direction and generated in the x coordinate detection period Px2 is referred to as a “fourth light emitting line”. For example, if the “fourth number” is 48, the “remote x coordinate detection pattern” is a light emission pattern in which the “fourth light emission line” having a width of 16 pixel columns sequentially moves in the x coordinate direction by 16 pixel columns. It becomes.

The fourth light emitting line is a light emitting line having a wider width and a larger amount of light emission than the second light emitting line for proximity described above. Accordingly, the distance to the panel 10 where the electronic pen can receive the light emitted from the fourth light emitting line is larger than the distance that the light emitted from the second light emitting line can be received.

In the x-coordinate detection period Px2, by displaying the remote x-coordinate detection pattern on the panel 10, the timing at which the electronic pen receives the light emitted from the fourth light emission line changes according to the position coordinates of the electronic pen. Therefore, the x coordinate of the position coordinates (x, y) when the electronic pen is used remotely can be detected by detecting the timing at which the light emission of the fourth light emitting line is received by the electronic pen.

In the present embodiment, as shown in FIG. 4, the time for applying the voltage Vdx of the x-coordinate detection pulse to each of the data electrodes D1 to Dm in the x-coordinate detection period Px2 (or the pulse width of the x-coordinate detection pulse) ) Is Tx12. This Tx12 is, for example, about 1 μsec.

In the erase period Pex of the remote x-coordinate detection subfield SFx2, an erase operation similar to the erase operation performed in the erase period Pex of the proximity x-coordinate detection subfield SFx1 is performed. As a result, a weak erase discharge is generated in the discharge cell that has generated the x-coordinate detection discharge.

The above is the outline of the drive voltage waveforms of the synchronization detection subfield SFo, the y coordinate detection subfield SFy, and the x coordinate detection subfield SFx.

As described above, in this embodiment, in the proximity y-coordinate detection subfield SFy1 and the proximity x-coordinate detection subfield SFx1, the light emission luminance is relatively low, but the position coordinate calculation accuracy is relatively high. The coordinate detection pattern and the x coordinate detection pattern are displayed on the panel 10. On the other hand, in the remote y-coordinate detection subfield SFy2 and the remote x-coordinate detection subfield SFx2, the y-coordinate detection pattern and the x-coordinate detection pattern with relatively low emission coordinates and relatively high emission luminance are displayed. 10 is displayed.

Therefore, when the electronic pen is used in contact with or in proximity to the panel 10, the light emission generated in the proximity y-coordinate detection subfield SFy1 and the proximity x-coordinate detection subfield SFx1 is set as a detection target, which is relatively high. The position coordinates can be calculated with accuracy. Further, when the electronic pen is used remotely, the light emission generated in the remote y-coordinate detection subfield SFy2 and the remote x-coordinate detection subfield SFx2 having a relatively high emission luminance is detected, and the electronic pen is separated from the panel 10. It is possible to calculate position coordinates even with an electronic pen located at a position (for example, about several meters).

Note that the voltage values applied to the electrodes in this embodiment are, for example, the voltage Vi1 = 150 (V), the voltage Vi2 = 350 (V), the voltage Vi3 = 200 (V), and the 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).

The gradient of the rising ramp waveform voltage generated in the initialization period Pi1 is about 1.5 (V / μsec), and the gradient of the descending ramp waveform voltage generated in the initialization periods Pi1 to Pi8, Pio, Piy, Pix is It is about −2.5 (V / μsec). Further, the gradient of the rising ramp waveform voltage generated in the sustain periods Ps1 to Ps8, the synchronization detection period Po, the erasure period Pey, and Pex is about 10 (V / μsec).

However, the specific numerical values such as the voltage value and the gradient described above are merely examples, and it is desirable that each voltage value and the gradient is optimally set based on the discharge characteristics of the panel 10 and the specifications of the image display device. .

Next, the image display system 100 in the present embodiment will be described.

FIG. 5 is a diagram schematically illustrating a configuration example of the image display system 100 according to the first embodiment of the present disclosure.

The image display system 100 shown in the present embodiment includes an image display device 30, a drawing device 40, and a plurality of

electronic pens

50a, 50b, 50c, and 50d as components, and drawing with the

electronic pens

50a, 50b, 50c, and 50d. Wireless communication is performed with the device 40.

Since the

electronic pens

50a, 50b, 50c, and 50d have the same configuration, they are collectively referred to as the electronic pen 50 in the following description. The number of electronic pens 50 included in the image display system 100 is not limited to four, and may be five or more, three or less, or one.

The image display device 30 includes an image display unit that displays an image and a drive circuit that drives the image display unit. In the present embodiment, an example in which a plasma display device having a panel 10 as an image display unit is used as the image display device 30 will be described.

The image display device 30 has a power supply for supplying necessary power to the image signal processing unit 31, the data electrode driving unit 32, the scan electrode driving unit 33, the sustain electrode driving unit 34, the control unit 35, and each circuit block as a driving circuit. Part (not shown). These drive circuits generate the drive voltage waveform described with reference to FIGS. 3 and 4 and apply it to the panel 10 to drive the panel 10.

The image signal processing unit 31 receives an image signal input from the outside, a drawing signal output from the drawing device 40, and a control signal supplied from the control unit 35. The image signal processing unit 31 combines the image signal and the drawing signal, and based on the combined signal or one of the signals, each of the discharge cells has red, green, and blue gradation values (one field). (Gradation value expressed by), and each gradation value is image data indicating lighting / non-lighting for each subfield (data in which light emission / non-light emission corresponds to digital signals “1” and “0”) To output.

In addition, the image signal processing unit 31 separates the horizontal synchronization signal and the vertical synchronization signal from the signal transmitted as the image signal, and outputs the horizontal synchronization signal and the vertical synchronization signal to the control unit 35.

The control unit 35 generates various control signals for controlling the operation of each circuit block based on the horizontal synchronization signal and the vertical synchronization signal, and generates the generated control signal in each circuit block (data electrode drive unit 32, scan electrode drive unit). 33, sustain electrode drive unit 34, and image signal processing unit 31).

The data electrode drive unit 32 generates the drive voltage waveforms shown in FIGS. 3 and 4 based on the image data output from the image signal processing unit 31 and the control signal supplied from the control unit 35, and each data electrode D1˜ Apply to Dm.

The sustain electrode driver 34 generates the drive voltage waveform shown in FIGS. 3 and 4 based on the control signal supplied from the controller 35 and applies it to the sustain electrodes SU1 to SUn.

The scan electrode drive unit 33 generates the drive voltage waveforms shown in FIGS. 3 and 4 based on the control signal supplied from the control unit 35 and applies the drive voltage waveforms to the scan electrodes SC1 to SCn.

The electronic pen 50 is placed in the image display area of the image display device 30 when the user directly contacts or approaches the electronic pen 50 to the panel 10 (proximity use) or away from the panel 10 (remote use). Used when inputting characters and drawings.

The electronic pen 50 detects the position coordinates by receiving light emitted from the panel 10 in the coordinate detection subfield. As described above, the position coordinates are detected by the electronic pen 50 receiving light emitted from the y coordinate detection pattern and the x coordinate detection pattern displayed on the panel 10 and calculating the y coordinate and the x coordinate.

The electronic pen 50 includes a light receiving element 52, a contact switch 53, a synchronization detection unit 54, a coordinate calculation unit 56, and a transmission unit 58.

Although not shown in FIG. 5, the electronic pen 50 has a power switch, a pilot lamp, a manual switch, and the like. The power switch is a switch for controlling the power on / off of the electronic pen 50. The pilot lamp is composed of a light emitting element (for example, LED) that can emit light by switching a plurality of light emission colors, and displays the operation state of the electronic pen 50 by switching light emission / non-light emission or light emission color.

The contact switch 53 is provided at the tip of the electronic pen 50 on the side where the light receiving element 52 is attached, and detects whether the tip of the electronic pen 50 is in contact with the image display surface of the panel 10. The contact switch 53 is turned on to output S1 = "1" if the tip of the electronic pen 50 is in contact with the panel 10, and is turned off to output S1 = "0" if not in contact. .

The user can switch S1 by operating a manual switch (not shown) instead of the contact switch 53, and can input characters and drawings on the image display surface when the electronic pen 50 is used remotely. . Further, the electronic pen 50 is configured so that the user can arbitrarily switch the drawing mode (for example, the color of the line used for drawing, the thickness of the line, the type of line, etc.) by operating the manual switch. May be.

The light receiving element 52 receives light emitted on the image display surface of the panel 10 and converts it into an electrical signal (light reception signal), and outputs the light reception signal to the synchronization detection unit 54 and the coordinate calculation unit 56. In the present embodiment, the position coordinate (x, y) of the electronic pen 50 is a position where the light receiving element 52 receives light emitted from the image display surface of the panel 10.

The electronic pen 50 may be configured to include a condensing lens for condensing the light emitted on the image display surface of the panel 10 onto the light receiving element 52.

The synchronization detection unit 54 detects light emission for synchronization detection (light emission generated by the synchronization detection discharge) generated in the synchronization detection period Po of the synchronization detection subfield SFo based on the light reception signal output from the light receiving element 52. Specifically, the synchronization detection unit 54 measures a generation interval of a plurality of (for example, four times) emission using a timer (not shown) included in the synchronization detection unit 54. Then, whether or not the occurrence interval matches a predetermined time interval (for example, time To1, time To2, time To3) is determined based on a plurality of threshold values (for example, time This is determined by comparing the measured time intervals with threshold values corresponding to To1, time To2, and time To3.

The synchronization detection unit 54 compares a light reception threshold value th and a light reception signal set in advance (not shown), and calculates a differential value for a light reception signal equal to or greater than the light reception threshold value th. The time that occurs is detected and each time is detected. The time difference between the time when the voltage for generating the discharge is applied to the discharge cell and the time when the discharge actually occurs and the peak of light emission is detected by the electronic pen 50 is measured in advance. You may use for correction of. The light reception threshold th may be set to the lowest level of the light reception signal that allows the light receiving element 52 to stably detect light emission, for example.

The synchronization detection unit 54 creates a coordinate reference signal based on one of the continuous multiple times (for example, four times) of light emission (for example, light emission generated at time to1). The time to1 is the time when the first synchronization detection pulse V1 is applied to the scan electrodes SC1 to SCn in the synchronization detection period Po of the synchronization detection subfield SFo.

The coordinate calculation unit 56 includes a counter that measures the length of time and an arithmetic circuit that performs an operation on the output of the counter (not shown).

Then, the coordinate calculation unit 56 selectively extracts a signal based on the light emission of the y coordinate detection pattern and a signal based on the light emission of the x coordinate detection pattern from the light reception signal based on the coordinate reference signal and the light reception signal, and outputs an electron in the image display area. The position coordinates (x, y) of the pen 50 are calculated, and the calculated position coordinates are output to the transmission unit 58.

Details of operations of the synchronization detection unit 54 and the coordinate calculation unit 56 will be described later.

The transmission unit 58 outputs a transmission signal based on the light reception signal output from the light receiving element 52. The transmission unit 58 includes a transmission circuit (not shown) that encodes an electrical signal, converts the encoded signal into a wireless signal such as infrared rays, and transmits the signal. A unique identification number (ID) assigned to each electronic pen 50, a signal indicating the position coordinates (x, y) of the electronic pen 50 calculated by the coordinate calculation unit 56, a contact switch 53 (or a manual switch) ) Is encoded and then converted to a radio signal. This radio signal is a transmission signal. The wireless signal is wirelessly transmitted to the receiving unit 42 of the drawing apparatus 40.

The drawing apparatus 40 includes a receiving unit 42 and a drawing unit 46. The drawing device 40 creates a drawing signal based on the position coordinates (x, y) calculated by the coordinate calculation unit 56 of the electronic pen 50 and outputs the drawing signal to the image display device 30. This drawing signal is a signal for displaying on the panel 10 characters, drawings and the like handwritten by the user using the electronic pen 50, and is substantially the same as the image signal.

The receiving unit 42 has a conversion circuit (not shown) that receives a radio signal wirelessly transmitted from the transmission unit 58 of the electronic pen 50, decodes the received signal, and converts it into an electrical signal. Then, the wireless signal wirelessly transmitted from the transmitter 58 is used to indicate the identification number (ID) of the electronic pen 50, the signal indicating the position coordinates (x, y) of the electronic pen 50, and the state of the contact switch 53 (or manual switch). It converts into the signal S1 etc. which represent, and outputs it to the drawing part 46. FIG. When there are a plurality of electronic pens 50, each signal transmitted from each electronic pen 50 is received and decoded.

The drawing unit 46 includes an image memory 47. Then, when the state S1 = 1 (the contact switch 53 or the manual switch is on), a drawing signal is created based on the position coordinates (x, y) output from the receiving unit 42 and stored in the image memory 47. To do. Therefore, the image memory 47 stores a drawing signal indicating a locus of change in the position coordinates (x, y) when the state S1 = 1 (a graphic input by the user using the electronic pen 50). The drawing unit 46 reads out the drawing signal stored in the image memory 47 and outputs the drawing signal to the image display device 30.

If there are a plurality of electronic pens 50 used in the image display system 100, the drawing unit 46 distinguishes the position coordinates (x, y) from each other so that the traces of the electronic pens 50 are not confused with each other. Create

Next, the sustain electrode drive unit 34, the data electrode drive unit 32, and the scan electrode drive unit 33 of the image display device 30 will be described with reference to FIGS. Each circuit block operates based on a control signal supplied from the control unit 35, but details of the path of the control signal are omitted in each drawing.

FIG. 6 is a circuit diagram schematically illustrating a configuration example of the sustain electrode driving unit 34 of the image display device 30 according to the first embodiment of the present disclosure.

The sustain electrode driving unit 34 includes a sustain pulse generation circuit 80 and a constant voltage generation circuit 85. Sustain pulse generation circuit 80 includes a power recovery circuit 81 and switching elements Q83 and Q84. The power recovery circuit 81 includes a power recovery capacitor C20, switching elements Q21 and Q22, backflow prevention diodes Di21 and Di22, and resonance inductors L21 and L22.

The sustain pulse generation circuit 80 generates a sustain pulse of the voltage Vs at the timing shown in FIGS. 3 and 4 and applies it to the sustain electrodes SU1 to SUn. In the synchronization detection period Po of the synchronization detection subfield SFo, the synchronization detection pulses V2 and V4 are applied to the sustain electrodes SU1 to SUn.

The constant voltage generation circuit 85 has switching elements Q86 and Q87, and applies the voltage Ve to the sustain electrodes SU1 to SUn at the timings shown in FIGS.

FIG. 7 is a circuit diagram schematically illustrating a configuration example of the data electrode driving unit 32 of the image display device 30 according to the first embodiment of the present disclosure.

The data electrode driving unit 32 operates based on the image data and control signals supplied from the image signal processing unit 31, but details of the paths of these signals are omitted in FIG.

The data electrode driver 32 includes switching elements Q91H1 to Q91Hm and Q91L1 to Q91Lm. Then, the data electrode driving unit 32 outputs the write pulse of the voltage Vd in each write period, the y-coordinate detection voltage Vdy (= voltage Vd) in the y-coordinate detection period Py, and the timing shown in FIGS. In the coordinate detection period Px, an x-coordinate detection pulse of voltage Vdx (= voltage Vd) is applied to each data electrode D1 to Dm.

FIG. 8 is a circuit diagram schematically illustrating a configuration example of the scan electrode driving unit 33 of the image display device 30 according to the first embodiment of the present disclosure.

The scan electrode driving unit 33 includes a sustain pulse generation circuit 55, a ramp waveform voltage generation circuit 60, and a scan pulse generation circuit 70. Hereinafter, the voltage input to the scan pulse generation circuit 70 is referred to as “reference potential A”.

Sustain pulse generation circuit 55 includes power recovery circuit 51 and switching elements Q55, Q56, and Q59. The power recovery circuit 51 includes a power recovery capacitor C10, switching elements Q11 and Q12, backflow prevention diodes Di11 and Di12, and resonance inductors L11 and L12. The switching element Q59 is a separation switch, and prevents reverse current flow.

Then, sustain pulse generating circuit 55 generates a sustain pulse of voltage Vs at the timing shown in FIGS. 3 and 4 and applies it to scan electrodes SC1 to SCn via scan pulse generating circuit. Further, in the synchronization detection period Po of the synchronization detection subfield SFo, synchronization detection pulses V1 and V3 are generated and applied to the scan electrodes SC1 to SCn via the scan pulse generation circuit 70.

The ramp waveform voltage generation circuit 60 includes

Miller integration circuits

61, 62, and 63, generates the ramp waveform voltage shown in FIGS. 3 and 4, and applies it to the scan electrodes SC1 to SCn via the scan pulse generation circuit. .

Miller integrating circuit 61 includes transistor Q61, capacitor C61, and resistor R61, and generates an upward ramp waveform voltage that gradually rises toward voltage Vt (= voltage Vi2). Alternatively, each voltage may be set so that a voltage obtained by superimposing the voltage Vp on the voltage Vt is equal to the voltage Vi2.

Miller integrating circuit 62 includes transistor Q62, capacitor C62, resistor R62, and backflow preventing diode Di62, and generates an upward ramp waveform voltage that gradually rises toward voltage Vr.

Miller integrating circuit 63 includes transistor Q63, capacitor C63, and resistor R63, and generates a downward ramp waveform voltage that gradually falls toward voltage Vi4.

Switching element Q69 is a separation switch and prevents reverse current flow.

The scan pulse generating circuit 70 includes switching elements QH1 to QHn, QL1 to QLn, Q72, a power source that generates a negative voltage Va, and a power source E71 that generates a voltage Vp. A connection point between the switching element QHi and the switching element QLi (i = 1 to n) is an output terminal of the scan electrode driver 33 and is connected to the scan electrode SCi.

Switching element Q72 clamps reference potential A to negative voltage Va (= voltage Vay = voltage Vax). Switching elements QL1 to QLn apply reference potential A to scan electrodes SC1 to SCn, and switching elements QH1 to QHn apply a voltage obtained by superimposing reference voltage A on voltage Vp to scan electrodes SC1 to SCn.

Then, the scan pulse generation circuit 70 clamps the reference potential A to the voltage Va and superimposes the voltage Vp on the reference potential A to generate the voltage Vc (Vc = Va + Vp), and scans while switching between the voltage Va and the voltage Vc. A pulse is generated and applied to scan electrodes SC1 to SCn.

The scan pulse generation circuit 70 generates a scan pulse at the timing shown in FIG. 3 and sequentially applies it to each of the scan electrodes SC1 to SCn in each address period of the image display subfield.

Further, as shown in FIG. 4, the scan pulse generation circuit 70 generates a y-coordinate detection pulse of voltage Vay (= voltage Va) in the y-coordinate detection period Py, and the x-coordinate detection voltage Vax in the x-coordinate detection period Px. (= Voltage Va) is generated and applied to scan electrodes SC1 to SCn.

A plurality of pairs of switching elements QHi and switching elements QLi (60 pairs in the example shown in FIG. 8) are integrated in one IC (scan driver IC).

Next, operations of the synchronization detection unit 54 and the coordinate calculation unit 56 of the electronic pen 50 shown in FIG. 5 will be described with reference to FIGS.

FIG. 9 is a diagram schematically illustrating an example of a position coordinate detection operation when the electronic pen 50 is used in proximity in the image display system 100 according to the first embodiment of the present disclosure.

FIG. 10 is a diagram schematically illustrating an example of a position coordinate detection operation when the electronic pen 50 is remotely used in the image display system 100 according to the first embodiment of the present disclosure.

9 and 10 show the coordinate reference signal det input to the coordinate calculation unit 56 and the light reception signal output from the light receiving element 52 in addition to the drive voltage waveform. The drive voltage waveforms shown in FIGS. 9 and 10 are the same as the drive voltage waveforms shown in FIG.

In the image display device 30 according to the present embodiment, the time Toy1 (FIG. 9) from the time to1 to the time ty01 (the time when the proximity y coordinate detection period Py1 starts), and the time tx01 (the proximity x coordinate detection period). Time Tox1 (FIG. 9) from time to Px1 (time starting Px1), Time Toy2 (FIG. 10) from time to1 to time ty02 (time starting remote y-coordinate detection period Py2), and Time to1 to time tx02 (remote) Each of the times Tox2 (FIG. 10) up to (the time when the x coordinate detection period Px2 starts) is determined in advance.

Therefore, the synchronization detecting unit 54 detects the four consecutive light emission intervals of the light emission intervals of time To1, time To2, and time To3, specifies time to1, and uses time to1 as a reference to time ty01 and time A coordinate reference signal det having rising edges at each of tx01, time ty02, and time tx02 is generated and output to the subsequent coordinate calculation unit 56.

Note that, as described above, the synchronization detection unit 54 detects the time at which a local peak occurs with respect to a light reception signal equal to or greater than the light reception threshold th, and detects each time and each time.

Note that the coordinate reference signal det is generated based on the time to1 in this embodiment, but may be generated based on any one of the times to2, to3, and to4 without being limited to the time to1.

When the electronic pen 50 is used in proximity, the coordinate calculation unit 56 calculates position coordinates based on the light emission of the proximity y coordinate detection subfield SFy1 and the proximity x coordinate detection subfield SFx1, as shown in FIG. Do.

Specifically, based on the coordinate reference signal det, the coordinate calculation unit 56 first determines a time Tyy1 from time ty01 to time ty1 when the light receiving element 52 first receives light emission equal to or greater than the light reception threshold th after time ty01. Is measured with a counter provided inside. Then, an internal arithmetic circuit subtracts the time Ty01 from the time Tyy1 and divides the subtraction result by Ty11 (pulse width of the y coordinate detection pulse). Then, the division result is multiplied by the first number. That is,
y coordinate = first number × ((Tyy1−Ty01) / Ty11).

Next, based on the coordinate reference signal det, the coordinate calculation unit 56 internally stores a time Txx1 from time tx01 to time txx1 when the light receiving element 52 first receives light emission equal to or greater than the light receiving threshold th after time tx01. Measure with the counter provided. Then, an internal arithmetic circuit subtracts the time Tx01 from the time Txx1, and divides the subtraction result by Tx11 (pulse width of the x coordinate detection pulse). Then, the division result is multiplied by (third number / 3). That is,
x coordinate = (third number / 3) × ((Txx1−Tx01) / Tx11). Note that “3” is the number of discharge cells constituting one pixel.

In this way, the coordinate calculation unit 56 calculates the position coordinates (x, y) of the electronic pen 50 used in proximity.

When the electronic pen 50 is used remotely, the coordinate calculation unit 56 calculates position coordinates based on the light emission of the remote y coordinate detection subfield SFy2 and the remote x coordinate detection subfield SFx2, as shown in FIG. Do.

Specifically, the coordinate calculation unit 56, based on the coordinate reference signal det, time Tyy2 from time ty02 to time tyy2 from when light reception element 52 first receives light emission equal to or greater than light reception threshold th after time ty02. Is measured with a counter provided inside. Then, an internal arithmetic circuit subtracts the time Ty02 from the time Tyy2, and divides the subtraction result by Ty12 (pulse width of the y coordinate detection pulse). Then, the division result is multiplied by the second number. That is,
y coordinate = second number × ((Tyy2−Ty02) / Ty12).

Next, based on the coordinate reference signal det, the coordinate calculation unit 56 internally stores a time Txx2 from time tx02 to time txx2 at which the light receiving element 52 first receives light emission equal to or greater than the light receiving threshold th after time tx02. Measure with the counter provided. Then, an internal arithmetic circuit subtracts the time Txx02 from the time Txx2, and divides the subtraction result by Tx12 (pulse width of the x coordinate detection pulse). Then, the division result is multiplied by (fourth number / 3). That is,
x coordinate = (fourth number / 3) × ((Txx2−Tx02) / Tx12). Note that “3” is the number of discharge cells constituting one pixel.

In this way, the coordinate calculation unit 56 calculates the position coordinates (x, y) of the electronic pen 50 used remotely.

Next, the operation of the image display system 100 in the present embodiment will be described.

FIG. 11 is a diagram schematically illustrating an example of an operation when the electronic pen 50 is used in proximity in the image display system 100 according to the first embodiment of the present disclosure.

FIG. 12 is a diagram schematically illustrating an example of an operation when the electronic pen 50 is remotely used in the image display system 100 according to the first embodiment of the present disclosure.

As shown in FIG. 11, in the y coordinate detection period Py1 of the proximity y coordinate detection subfield SFy1, the first light emission that sequentially moves from the upper end (first row) to the lower end (n row) of the image display area. The line Ly1 is displayed on the panel 10. Further, in the x-coordinate detection period Px1 of the proximity x-coordinate detection subfield SFx1, the image display area sequentially moves from the left end portion (first pixel column) to the right end portion (m / 3 pixel row). Two emission lines Lx1 are displayed on the panel 10.

Therefore, if the light receiving element 52 of the electronic pen 50 used in the proximity receives light emission of “coordinate (x, y)” on the image display surface of the panel 10, the first light emitting line Ly 1 changes the coordinate (x, y). The light receiving element 52 receives light emission at the passing time tyy1 and the time txx1 when the second light emitting line Lx1 passes the coordinates (x, y).

Accordingly, as shown in FIG. 9, the light receiving element 52 outputs a light reception signal indicating that the light emission of the first light emission line Ly1 is received at time tyy1, and receives the light emission of the second light emission line Lx1. A light reception signal indicating this is output at time txx1.

As shown in FIG. 12, in the y-coordinate detection period Py2 of the remote y-coordinate detection subfield SFy2, the third light emission that sequentially moves from the upper end (first row) to the lower end (n-th row) of the image display area. The line Ly2 is displayed on the panel 10. Further, in the x-coordinate detection period Px2 of the remote x-coordinate detection subfield SFx2, the image display area sequentially moves from the left end (first pixel column) to the right end (m / 3 column). Four emission lines Lx2 are displayed on the panel 10.

Therefore, if the light receiving element 52 of the electronic pen 50 used remotely receives light of “coordinate (x, y)” on the image display surface of the panel 10, the third light emitting line Ly 2 changes the coordinate (x, y). The light receiving element 52 receives light emission at the passing time tyy2 and at the time txx2 when the fourth light emitting line Lx2 passes the coordinates (x, y).

Accordingly, as shown in FIG. 10, the light receiving element 52 outputs a light reception signal indicating that the light emission of the third light emission line Ly2 is received at time tyy2, and receives the light emission of the fourth light emission line Lx2. A light reception signal indicating this is output at time txx2.

Note that switching between proximity use and remote use in the electronic pen 50 may be performed by, for example, providing a switch for switching in the electronic pen 50 and turning on / off the switch. Alternatively, the electronic pen 50 may be configured to be switched by attaching a condensing lens. Alternatively, if the light reception signal by the first light emission line Ly1 is equal to or greater than the light reception threshold th, the y coordinate is calculated based on the light reception signal by the first light emission line Ly1, and the light reception signal by the first light emission line Ly1 is received. If it is less than the threshold value th, the coordinate calculation unit 56 may be configured to calculate the y-coordinate based on the light reception signal from the third light-emitting line Ly2. Similarly, if the light reception signal by the second light emission line Lx1 is equal to or greater than the light reception threshold th, the x coordinate is calculated based on the light reception signal by the second light emission line Lx1, and the light reception signal by the second light emission line Lx1 is received. If it is less than the threshold th, the coordinate calculation unit 56 may be configured to calculate the x-coordinate based on the light reception signal from the fourth light emission line Lx2.

FIG. 13 is a diagram schematically illustrating an example of an operation when performing handwriting input with the electronic pen 50 in the image display system 100 according to the first embodiment of the present disclosure.

FIG. 13 shows an example when the electronic pen 50 is used in proximity.

As shown in FIG. 13, the drawing unit 46 draws a drawing pattern (for example, a pattern such as a white circle) having a color and a size corresponding to the drawing mode around the pixel corresponding to the position coordinate (x, y). Generate a drawing signal. This drawing signal is accumulated in the image memory 47 of the drawing unit 46 during the period of the state S1 = 1 (the contact switch 53 or the manual switch is on). Then, the image display device 30 displays an image based on the drawing signal stored in the image memory 47 of the drawing unit 46 on the panel 10.

Therefore, for example, as shown in FIG. 13, when the user moves the position coordinates of the electronic pen 50, a symbol indicating the locus of the movement is displayed on the panel 10. Thus, the panel 10 displays a graphic input by handwriting using the electronic pen 50.

As described above, in the image display device 30 according to the present embodiment, the proximity y-coordinate detection subfield SFy1 that displays the first light-emitting line Ly1 that emits light with a width corresponding to the “first number” on the panel 10. In addition to the proximity x-coordinate detection subfield SFx1 for displaying on the panel 10 the second light emitting line Lx1 that emits light with a width corresponding to the “third number”, the “second number” is larger than the “first number”. The remote y-coordinate detection subfield SFy2 for displaying on the panel 10 the third light-emitting line Ly2 that emits light with a width corresponding to the “number”, and the “fourth number” larger than the “third number” A remote x-coordinate detection subfield SFx2 for displaying on the panel 10 the fourth light-emitting line Lx2 that emits light with a width is generated.

As a result, even in the electronic pen 50 that is located away from the panel 10 and cannot receive light emitted from the first light-emitting line Ly1 and the second light-emitting line Lx1 with sufficient intensity for calculating the position coordinates, the third light-emitting line Ly2 and Since the position coordinates can be calculated by receiving the light emitted from the fourth light emitting line Lx2, the electronic pen 50 can be used remotely.

(Embodiment 2)
FIG. 14 is a diagram schematically illustrating an example of a drive voltage waveform applied to each electrode of the panel 10 in the coordinate detection subfield according to the second embodiment of the present disclosure.

The configuration and operation of the image display system in the second embodiment are the same as those in the first embodiment, and the types and number of subfields included in one field are the same as those in the first embodiment. The drive voltage waveform generated in each subfield is the same as that in the first embodiment except for the initialization period, but the drive voltage waveform generated in the initialization period is different from that in the first embodiment in the second embodiment. Hereinafter, differences from the first embodiment will be described.

In the initialization period Pio of the synchronization detection subfield SFo in the second embodiment, a forced initialization operation is performed. In the initialization period Pio, the voltage Vd is applied to the data electrodes D1 to Dm, and the voltage 0 (V) is applied to the sustain electrodes SU1 to SUn. After applying voltage 0 (V) to scan electrodes SC1 to SCn, an upward ramp waveform voltage rising from voltage Vi1 lower than the discharge start voltage to voltage Vi2 exceeding the discharge start voltage is applied. Next, a voltage 0 (V) is applied to the data electrodes D1 to Dm, and a positive voltage Ve1 lower than the voltage Ve is applied to the sustain electrodes SU1 to SUn. A downward ramp waveform voltage that drops from voltage 0 (V) to negative voltage Vi4 is applied to scan electrodes SC1 to SCn.

The initializing discharge is generated in each discharge cell by this forced initializing operation, and the wall voltage on each electrode is adjusted to a voltage suitable for the address operation in the subsequent address period Pwo.

In the initialization period Piy of the proximity y coordinate detection subfield SFy1 in the second embodiment, first, the voltage 0 (V) is applied to each of the data electrodes D1 to Dm and the sustain electrodes SU1 to SUn, and the scan electrodes SC1 to SCn. Is applied with a downward ramp waveform voltage that drops from the voltage 0 (V) to the negative voltage Vi4. Next, voltage Vs is applied to scan electrodes SC1 to SCn while voltage 0 (V) is applied to data electrodes D1 to Dm and sustain electrodes SU1 to SUn. Next, voltage 0 (V) is applied to scan electrodes SC1 to SCn while voltage 0 (V) is applied to data electrodes D1 to Dm, and voltage Vs is applied to sustain electrodes SU1 to SUn. Next, voltage Ve1 is applied to sustain electrodes SU1 to SUn, and a downward ramp waveform voltage that drops from voltage 0 (V) to negative voltage Vi4 is applied to scan electrodes SC1 to SCn.

Thereby, an initializing discharge is generated in each discharge cell, and the wall voltage of each discharge cell is adjusted to a wall voltage suitable for the proximity y coordinate detection pattern display operation in the subsequent y coordinate detection period Py1.

In the initialization period Pix of the proximity x-coordinate detection subfield SFx1 in the second embodiment, a forced initialization operation is performed. In the initialization period Pix, first, the voltage Vd is applied to the data electrodes D1 to Dm, and the voltage 0 (V) is applied to the sustain electrodes SU1 to SUn. After applying voltage 0 (V) to scan electrodes SC1 to SCn, an upward ramp waveform voltage rising from voltage Vi1 to voltage Vi2 is applied. Next, the voltage 0 (V) is applied to the data electrodes D1 to Dm, and the voltage Ve1 is applied to the sustain electrodes SU1 to SUn. A downward ramp waveform voltage that drops from voltage 0 (V) to negative voltage Va is applied to scan electrodes SC1 to SCn, and then an upward ramp waveform voltage that rises from voltage 0 (V) to positive voltage Vr. Apply. Next, voltage Ve is applied to sustain electrodes SU1 to SUn, and a downward ramp waveform voltage that drops from voltage 0 (V) to negative x coordinate detection voltage Vax is applied to scan electrodes SC1 to SCn.

This initializing operation causes an initializing discharge in each discharge cell, and the wall voltage on each electrode is adjusted to a wall voltage suitable for the proximity x coordinate detection pattern display operation in the subsequent x coordinate detection period Px1.

In the initialization period Py of the remote y-coordinate detection subfield SFy2 in the second embodiment, a drive voltage waveform similar to that in the initialization period Pio of the synchronization detection subfield SFo shown in FIG. 14 is generated and applied to each electrode. This forced initializing operation causes an initializing discharge in each discharge cell, and the wall voltage of each discharge cell is adjusted to a wall voltage suitable for the remote y-coordinate detection pattern display operation in the subsequent y-coordinate detection period Py2.

In the initialization period Pix of the remote x-coordinate detection subfield SFx2 in the second embodiment, a drive voltage waveform similar to that in the initialization period Pix of the proximity x-coordinate detection subfield SFx1 shown in FIG. Apply. This forced initializing operation causes an initializing discharge in each discharge cell, and the wall voltage of each discharge cell is adjusted to a wall voltage suitable for the remote x-coordinate detection pattern display operation in the subsequent x-coordinate detection period Px2.

In the erase period Pex of the remote x-coordinate detection subfield SFx2 in the second embodiment, the erase operation similar to that in the first embodiment may be performed, but the erase operation illustrated in FIG. 14 may be performed. That is, an upward ramp waveform voltage rising from voltage 0 (V) to positive voltage Vr is applied to scan electrodes SC1 to SCn while voltage 0 (V) is applied to sustain electrodes SU1 to SUn and data electrodes D1 to Dm. . Next, the voltage Vd is applied to the data electrodes D1 to Dm while the voltage 0 (V) is applied to the sustain electrodes SU1 to SUn, and the voltage 0 (V) is applied to the scan electrodes SC1 to SCn. An upward ramp waveform voltage rising from the voltage Vi1 to the voltage Vi2 is applied.

This causes a weak erasure discharge in the discharge cell that has generated the x-coordinate detection discharge.

In this embodiment, the initialization operation as described above may be performed in each initialization period of the coordinate detection subfield.

In the first and second embodiments, it is desirable to set the time intervals when the synchronous detection discharge is generated a plurality of times at different times so that the first synchronous detection discharge can be easily specified.

In the first and second embodiments, each coordinate detection subfield may be generated at a rate of once in a plurality of fields, for example.

In the first and second embodiments, when displaying the y-coordinate detection pattern, a pixel row that does not emit light may be provided. Similarly, when displaying the x-coordinate detection pattern, a pixel column that does not emit light may be provided.

In

Embodiments

1 and 2, the order of occurrence of each coordinate detection subfield is not limited to the order of occurrence described above. For example, the x coordinate detection subfield may be generated first, and then the y coordinate detection subfield may be generated.

In the first and second embodiments, when the electronic pen calculates the position coordinates based on the light emission generated in the proximity x coordinate detection subfield SFx1 and the proximity y coordinate detection subfield SFy1, it is referred to as “proximity use”. The case where the position coordinates are calculated based on the light emission generated in the x-coordinate detection subfield SFx2 and the remote y-coordinate detection subfield SFy2 is referred to as “remote use”.

In the first and second embodiments, the configuration in which the drawing device is provided independently of the image display device is shown. As an example of this configuration, for example, a function connected to the computer connected to the image display device is equivalent to the drawing device. And a drawing signal is generated using the computer. However, for example, the drawing device may be provided as a single device, or the drawing device may be provided in the image display device.

Each circuit block shown in the first and second embodiments may be configured as an electric circuit that performs each operation shown in the embodiment, or substantially the same as each operation shown in the embodiment. A microcomputer or a computer programmed to operate may be used.

It should be noted that the specific numerical values shown in the first and second embodiments are merely examples of the embodiment, and the present invention is not limited to these numerical values. It is desirable to set each numerical value to an optimal value according to the specifications of the image display system.

The present disclosure is useful as an image display device, an image display device driving method, and an image display system because the position coordinates can be calculated even with an electronic pen located at a position away from the panel.

DESCRIPTION OF SYMBOLS 10 Panel 11 Front substrate 12 Scan electrode 13 Sustain electrode 14 Display electrode pair 15,23 Dielectric layer 16 Protective layer 21 Back substrate 22 Data electrode 24 Partition 25, 25R, 25G, 25B Phosphor layer 30 Image display device 31 Image signal processing Unit 32 Data electrode drive unit 33 Scan electrode drive unit 34 Sustain electrode drive unit 35 Control unit 40 Drawing device 42 Reception unit 46 Drawing unit 47 Image memory 50, 50a, 50b, 50c, 50d Electronic pen 51, 81 Power recovery circuit 52 Light reception Element 53 Contact switch 54 Synchronization detector 55, 80 Sustain pulse generator 56 Coordinate calculator 58 Transmitter 60 Ramp waveform voltage generator 61, 62, 63 Miller integrator 70 Scan pulse generator 85 Constant voltage generator 100 Image display system Ly1 first departure Line Lx1 Second light emission line Ly2 Third light emission line Lx2 Fourth light emission line Di11, Di12, Di21, Di22, Di62 Diodes L11, L12, L21, L22 Inductors Q11, Q12, Q21, Q22, Q55, Q56, Q59 Q69, Q72, Q83, Q84, Q86, Q87, QH1 to QHn, QL1 to QLn, Q91H1 to Q91Hm, Q91L1 to Q91Lm Switching elements C10, C20, C61, C62, C63 capacitors R61, R62, R63 resistors Q61, Q62, Q63 Transistor IN61, IN62, IN63 Input terminal E71 Power supply SFy1 Proximity y coordinate detection subfield SFx1 Proximity x coordinate detection subfield SFy2 Remote y coordinate detection subfield SFx2 Remote x Coordinate detection subfield SFo Sync detection subfield SF1 to SF8 Image display subfield

Claims

A driving method of an image display device including a plasma display panel in which discharge cells are formed at each of intersections of scan electrodes, sustain electrodes, and data electrodes,
An image display subfield for displaying an image on the plasma display panel;
A proximity y-coordinate detection subfield for sequentially performing an operation of simultaneously applying a y-coordinate detection pulse to the first number of the scan electrodes while applying a y-coordinate detection voltage to the data electrodes;
A remote y-coordinate detection subfield for sequentially performing an operation of simultaneously applying the y-coordinate detection pulses to the second number of the scan electrodes while applying the y-coordinate detection voltage to the data electrodes;
A proximity x-coordinate detection subfield for sequentially performing an operation of simultaneously applying x-coordinate detection pulses to the third number of the data electrodes while applying the x-coordinate detection voltage to the scan electrodes;
Generating a remote x-coordinate detection subfield for sequentially performing an operation of simultaneously applying the x-coordinate detection pulses to the fourth number of the data electrodes while applying the x-coordinate detection voltage to the scan electrodes;
Setting the second number to a value greater than the first number;
The method for driving an image display device, wherein the fourth number is set to a value larger than the third number.
The method for driving an image display device according to claim 1, wherein the first number is 1 and the third number is 1.
A plasma display panel in which a discharge cell is formed at each of the intersection of the scan electrode and the sustain electrode and the data electrode;
An image display device comprising: a drive circuit configured to drive one of a plurality of subfields and drive the plasma display panel;
The drive circuit is
An image display subfield for displaying an image on the plasma display panel;
A proximity y-coordinate detection subfield for sequentially performing an operation of simultaneously applying a y-coordinate detection pulse to the first number of the scan electrodes while applying a y-coordinate detection voltage to the data electrodes;
A remote y-coordinate detection subfield for sequentially performing an operation of simultaneously applying the y-coordinate detection pulses to the second number of the scan electrodes while applying the y-coordinate detection voltage to the data electrodes;
A proximity x-coordinate detection subfield for sequentially performing an operation of simultaneously applying x-coordinate detection pulses to the third number of the data electrodes while applying the x-coordinate detection voltage to the scan electrodes;
Generating a remote x-coordinate detection subfield for sequentially performing an operation of simultaneously applying the x-coordinate detection pulses to the fourth number of the data electrodes while applying the x-coordinate detection voltage to the scan electrodes;
Setting the second number to a value greater than the first number;
The image display device characterized in that the fourth number is set to a larger numerical value than the third number.
The drive circuit is
The image display apparatus according to claim 3, wherein the first number is set to 1 and the third number is set to 1. 5.
A plasma display panel in which a discharge cell is formed at each of the intersections of the scan electrode, the sustain electrode and the data electrode, and an image display device including a drive circuit for driving the plasma display panel;
An image display system including an electronic pen and a drawing device,
The drive circuit is
An image display subfield for displaying an image on the plasma display panel;
A proximity y-coordinate detection subfield for sequentially performing an operation of simultaneously applying a y-coordinate detection pulse to the first number of the scan electrodes while applying a y-coordinate detection voltage to the data electrodes;
A remote y-coordinate detection subfield for sequentially performing an operation of simultaneously applying the y-coordinate detection pulses to the second number of the scan electrodes while applying the y-coordinate detection voltage to the data electrodes;
A proximity x-coordinate detection subfield for sequentially performing an operation of simultaneously applying x-coordinate detection pulses to the third number of the data electrodes while applying the x-coordinate detection voltage to the scan electrodes;
Generating a remote x-coordinate detection subfield for sequentially performing an operation of simultaneously applying the x-coordinate detection pulses to the fourth number of the data electrodes while applying the x-coordinate detection voltage to the scan electrodes;
Setting the second number to a number greater than the first number and the fourth number to a number greater than the third number;
The electronic pen is
A light receiving element that receives light emitted from the plasma display panel and outputs a light reception signal;
Synchronizing to generate a coordinate reference signal synchronized with the proximity y coordinate detection subfield, the proximity x coordinate detection subfield, the remote y coordinate detection subfield, and the remote x coordinate detection subfield based on the received light signal. A detection unit;
A coordinate calculation unit for calculating coordinates on the plasma display panel pointed to by the electronic pen based on the coordinate reference signal and the light reception signal;
A transmission unit that transmits the coordinates calculated by the coordinate calculation unit to the drawing device;
The drawing device includes:
A receiving unit for receiving coordinates transmitted from the electronic pen;
An image display system comprising: a drawing unit that generates a drawing signal based on the coordinates received by the receiving unit and outputs the drawing signal to the image display device.