JP2014203426A - Electronic pen and image display system including the electronic pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a user-friendly electronic pen capable of inputting on an image display device from a position separated away from an image display plane.SOLUTION: An electronic pen 50 includes: light receiving elements 52 and 54 each of which generates a light-receiving signal of a magnitude proportional to amount of received light; a synchronization detection section 56 that generates a coordinate reference signal based on the light-receiving signal output from the light receiving elements 52 and 54; a coordinate calculation section 57 that calculates positional coordinates based on the light-receiving signal and the coordinate reference signal; and a distance determination section 91 that determines the distance to an image display device 30 based on the light-receiving signal. The light-receiving signal used by the synchronization detection section 56, the light-receiving signal used for calculating of positional coordinates by the coordinate calculation section 57 and the light-receiving signal used for determining the distance by the distance determination section 91 are different from each other.

Description

  The present disclosure relates to an electronic pen that inputs characters and drawings to an image display device and an image display system including the electronic pen.

  Some image display devices have a function of allowing handwriting input of characters and drawings using a pen-type pointing device called “electronic pen” or “light pen”.

  For example, Patent Document 1 discloses a technique related to an electronic blackboard that directly fills a display screen with a light pen and displays the screen.

  Patent Document 2 discloses a coordinate position detection apparatus and a coordinate position detection method for a plasma display panel that detect a coordinate position on the plasma display panel using an optical sensor.

JP-A-4-141498 JP 2001-318765 A

  An object of the present disclosure is to provide an electronic pen that can improve usability in an electronic pen that allows input to an image display device from a position away from an image display surface, and an image display system including the electronic pen. .

  An electronic pen according to the present disclosure includes a light receiving element that generates a light reception signal having a magnitude corresponding to the amount of light received, a synchronization detection unit that generates a coordinate reference signal based on the light reception signal output from the light reception element, a light reception signal, and a coordinate A coordinate calculation unit that calculates position coordinates based on the reference signal, and a distance determination unit that determines a distance to the image display device based on the light reception signal. The light reception signal used in the synchronization detection unit, the light reception signal used for calculating the position coordinates in the coordinate calculation unit, and the light reception signal used for distance determination in the distance determination unit are different from each other.

  In addition, the synchronization detection unit of the electronic pen according to the present disclosure may generate a distance detection signal that allows the distance determination unit to accept the received light signal, and may generate the coordinate reference signal and the distance detection signal at different timings. .

  The distance determination unit of the electronic pen according to the present disclosure may determine the distance by comparing the received light signal received based on the distance detection signal with a preset distance threshold value.

  In addition, the electronic pen according to the present disclosure is detachably mounted with an attachment having a condensing lens for receiving light emitted from the image display device at a position away from the image display device, and the distance is determined only when the attachment is mounted. The part may operate.

  In the electronic pen according to the present disclosure, the determination result output from the distance determination unit may be maintained until it is reset.

  In addition, the synchronization detection unit of the electronic pen according to the present disclosure is configured to detect light emission of a predetermined pattern, and the synchronization detection unit generates a reset when the light emission of the predetermined pattern cannot be detected for a predetermined time. May be.

  An image display system according to the present disclosure includes a synchronization detection subfield, a proximity y coordinate detection subfield, a proximity x coordinate detection subfield, a remote y coordinate detection subfield, and a remote x coordinate detection subfield. And an electronic pen having a light receiving element that generates a light receiving signal having a magnitude corresponding to the amount of light received, and drawing is performed in the image display area of the image display device at a position based on the position coordinates of the electronic pen. The electronic pen emits light generated in the image display device in the proximity y-coordinate detection subfield and the proximity x-coordinate detection subfield, or is transmitted to the image display device in the remote y-coordinate detection subfield and the remote x-coordinate detection subfield. A coordinate calculation unit that calculates position coordinates based on any of the generated light emissions, and a distance determination unit that determines a distance from the electronic pen to the image display device based on the light emission generated in the image display device. Then, the distance determination unit, when the coordinate calculation unit calculates the position coordinates based on the light emission of the remote y coordinate detection subfield and the remote x coordinate detection subfield, the proximity y coordinate detection subfield and the proximity x A distance from the electronic pen to the image display device is determined based on at least one light emission of the coordinate detection subfield.

  In addition, the synchronization detection unit of the image display system according to the present disclosure includes a coordinate reference signal serving as a reference for calculating position coordinates based on light emission generated in the image display device in the synchronization detection subfield, and a light reception signal to the distance determination unit. May be generated at different timings, and the coordinate reference signal and the distance detection signal may be generated at different timings.

  The distance determination unit of the image display system according to the present disclosure may determine the distance by comparing the received light signal received based on the distance detection signal with a preset distance threshold value.

  Further, in the image display system according to the present disclosure, an attachment having a condensing lens for receiving light emission at a position away from the image display device is detachably attached, and the distance determination unit operates only when the attachment is attached. It may be a configuration.

  In addition, the image display system according to the present disclosure includes a detection effective region and a non-detection region in the image display region. In the detection effective region, the detected position coordinates are used for drawing in the image display device. A configuration may be employed in which the coordinates are not detected or the detected position coordinates are not used for drawing, and the size of the non-detection region is changed based on the determination result in the distance determination unit.

  Further, in the image display system according to the present disclosure, the size of the non-detection area may be maintained until reset.

  In the image display system according to the present disclosure, the synchronization detection unit may generate a reset when the light emission of the synchronization detection subfield cannot be detected for a predetermined time.

  The image display system including the electronic pen and the electronic pen according to the present disclosure is effective for improving the usability of the electronic pen when performing input to the image display device from a position away from the image display surface.

It is a figure which shows roughly the example of 1 structure of the image display system in Embodiment 1 of this invention. It is a disassembled perspective view which shows an example of the structure of the panel used for the image display apparatus in Embodiment 1 of this invention. It is a figure which shows an example of the electrode arrangement | sequence of the panel used for the image display apparatus in Embodiment 1 of this invention. It is a figure which shows roughly an example of the drive voltage waveform applied to each electrode of a panel in the image display subfield in Embodiment 1 of this invention. It is a figure which shows roughly an example of the drive voltage waveform applied to each electrode of a panel in the coordinate detection subfield in Embodiment 1 of this invention. It is a figure which shows roughly an example of the position coordinate detection operation | movement when using an electronic pen near in the image display system in Embodiment 1 of this invention. It is a figure which shows roughly an example of the position coordinate detection operation | movement when using an electronic pen remotely in the image display system in Embodiment 1 of this invention. It is a perspective view which shows the external appearance of the electronic pen and the attachment for electronic pens in Embodiment 1 of this invention. It is a figure which shows schematically an example of an operation | movement when using an electronic pen near in the image display system in Embodiment 1 of this invention. It is a figure which shows schematically an example of operation | movement when using an electronic pen remotely in the image display system in Embodiment 1 of this invention. It is a figure which shows roughly an example of operation | movement when performing handwritten input with an electronic pen in the image display system in Embodiment 1 of this invention. It is a figure which shows roughly an example of operation | movement when using an electronic pen as a pointer in the image display system in Embodiment 1 of this invention. It is a figure which shows roughly an example of the light reception range of an electronic pen when using the electronic pen in Embodiment 2 of this invention remotely. It is a figure which shows roughly another example of the light reception range of an electronic pen when using the electronic pen in Embodiment 2 of this invention remotely. It is a figure which shows roughly the example of 1 setting of the detection effective area | region and non-detection area | region in a panel when the electronic pen in Embodiment 2 of this invention is used remotely. It is a figure which shows roughly the other example of a setting of the detection effective area | region and non-detection area | region in a panel when the electronic pen in Embodiment 2 of this invention is used remotely. It is a figure which shows roughly the relationship between the detection coordinate and display coordinate in Embodiment 2 of this invention. It is a figure which shows roughly the example of 1 structure of the image display system in Embodiment 2 of this invention.

  Hereinafter, an electronic pen according to an embodiment of the present invention will be described with reference to the drawings. In the following embodiments, as an example, a configuration in which the electronic pen according to the embodiments of the present invention is used in an image display system including a plasma display device as a component will be described.

(Embodiment 1)
FIG. 1 is a diagram schematically showing a configuration example of an image display system 100 according to Embodiment 1 of the present invention.

  The image display system 100 shown in the present embodiment includes an image display device 30, a drawing device 40, and an electronic pen 50 as components, and performs wireless communication between the electronic pen 50 and the drawing device 40. Although one electronic pen 50 is shown in FIG. 1, the image display system 100 may include a plurality of electronic pens 50.

  The image display device 30 includes a display device that displays an image and a drive circuit that drives the display device. Hereinafter, an example in which a plasma display device having a plasma display panel (hereinafter abbreviated as “panel”) 10 as a display device is used as the image display device 30 will be described. The image display device 30 is, for example, a liquid crystal panel or an organic EL device. Other display devices such as a panel and an LED panel may be used.

  The drawing device 40 includes a receiving unit 42 and a drawing unit 46.

  The electronic pen 50 includes a first light receiving element 52, a second light receiving element 54, a contact switch 53, a plurality of (or a single) manual switch 83, a synchronization detection unit 56, a coordinate calculation unit 57, a transmission unit 58, and an attachment detection switch. 86, and a distance determination unit 91. Although two manual switches 83 are shown in FIG. 1, the number of manual switches 83 provided in the electronic pen 50 is not limited to two. Hereinafter, the first light receiving element and the second light receiving element are also simply referred to as “light receiving elements”, respectively.

  In addition, the electronic pen 50 according to the present embodiment can be detachably mounted with an electronic pen attachment (hereinafter simply referred to as “attachment”) 80 including a condenser lens 84.

  Hereinafter, first, the image display device 30 will be described with reference to FIGS. 1, 2, and 3. Next, drive voltage waveforms generated in the image display device 30 will be described with reference to FIGS. The pen 50 and the drawing device 40 will be described.

  As shown in FIG. 1, the image display device 30 includes an image signal processing circuit 31, a data electrode drive circuit 32, a scan electrode drive circuit 33, a sustain electrode drive circuit 34, a timing generation circuit 35, and each circuit block as drive circuits. Is provided with a power supply circuit (not shown) for supplying the necessary power. The panel 10 is driven by these drive circuits.

  FIG. 2 is an exploded perspective view showing an example of the structure of panel 10 used in image display device 30 according to Embodiment 1 of the present invention.

  On the front substrate 11 made of glass, a plurality of display electrode pairs 14 composed of the scanning electrodes 12 and the sustain electrodes 13 are formed, and a dielectric layer 15 is formed so as to cover the display electrode pairs 14, and the dielectric layer 15 A protective layer 16 is 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 so as to cover the data electrodes 22, and a grid-like partition wall 24 is formed thereon. The phosphor layer 25 (phosphor layer 25R that emits red (R), phosphor layer 25G that emits green (G), and blue (B) emits light on the side surfaces of the barrier ribs 24 and the surface of the dielectric layer 23. A phosphor layer 25B) is provided.

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

  FIG. 3 is a diagram showing an example of an electrode arrangement of panel 10 used in image display device 30 according to the first embodiment of the present invention.

  In panel 10, n scan electrodes SC1 to SCn (scan electrode 12 in FIG. 2) and n sustain electrodes SU1 to SUn (sustain electrode 13 in FIG. 2) extended in the first direction are arranged. M data electrodes D1 to Dm (data electrode 22 in FIG. 2) extended in a second direction orthogonal to 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).

  One discharge cell is formed in a region where a 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 red, green, and blue discharge cells adjacent to each other constitutes one pixel.

  As shown in FIG. 1, the image signal processing circuit 31 receives an image signal input from the outside, a drawing signal output from the drawing apparatus 40, and a timing signal supplied from the timing generation circuit 35. The image signal processing circuit 31 synthesizes the image signal and the drawing signal, and sets the red, green, and blue tone values (tone values expressed in one field) to each discharge cell based on the synthesized signal. Each gradation value is converted into image data indicating lighting / non-lighting for each subfield (data corresponding to light emission / non-light emission corresponding to digital signals “1” and “0”) and output.

  The timing generation circuit 35 separates a horizontal synchronizing signal and a vertical synchronizing signal from a signal transmitted as an image signal, and generates various timing signals for controlling the operation of each circuit block based on the horizontal synchronizing signal and the vertical synchronizing signal. Occur. The generated timing signal is supplied to each circuit block (data electrode drive circuit 32, scan electrode drive circuit 33, sustain electrode drive circuit 34, image signal processing circuit 31, etc.).

  The data electrode drive circuit 32 generates a drive voltage waveform based on the image data output from the image signal processing circuit 31 and the timing signal supplied from the timing generation circuit 35, and applies it to the data electrodes D1 to Dm.

  Sustain electrode drive circuit 34 includes a sustain pulse generation circuit and a circuit (not shown) for generating voltage Ve, generates a drive voltage waveform based on a timing signal supplied from timing generation circuit 35, and generates each sustain electrode SU1. Apply to ~ SUn.

  Scan electrode drive circuit 33 includes a ramp waveform voltage generation circuit, a sustain pulse generation circuit, and a scan pulse generation circuit (not shown), and generates a drive voltage waveform based on a timing signal supplied from timing generation circuit 35. It applies to each scan electrode SC1-SCn.

  Next, driving voltage waveforms generated in the image display device 30 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. 4) for displaying an image on panel 10 and a plurality of coordinates for detecting “position coordinates” of electronic pen 50 in one field. And a detection subfield (shown in FIG. 5). The “position coordinates” are the coordinates of the position indicated by the electronic pen 50 in the image display area of the panel 10 (the coordinates indicating the position of the electronic pen 50).

  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.

  The initialization operation in the initialization period is selectively performed only in the “forced initialization operation” in which the discharge discharge is forcibly generated in the discharge cell, and only in the discharge cell in which the address discharge is generated in the address period of the immediately preceding subfield. There is a “selective initialization operation” that generates an initialization discharge.

  The number of image display subfields in one field is eight (subfields SF1 to SF8), for example, and the luminance weight of each subfield is (1, 34, 21, 13, 8, 5, 3, 2), for example. It is.

  FIG. 4 schematically shows an example of a drive voltage waveform applied to each electrode of panel 10 in subfields SF1 to SF3 of the image display subfield according to Embodiment 1 of the present invention.

  In the first half of the initialization period Pi1 of the subfield SF1 in which the forced initialization 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 to voltage Vi2 is applied.

  In the second half of the initialization period Pi1, 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 that gently falls from voltage 0 (V) to negative voltage Vi4 is applied to scan electrodes SC1 to SCn.

  This forced initializing operation causes an initializing discharge in each discharge cell, 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.

  The initialization discharge generated by the ramp waveform voltage is weaker than the address discharge or the sustain discharge, and the light emission due to the initialization discharge has a lower luminance than the light emission due to the address discharge or the sustain discharge.

  Note that the discharge cells to which the forced initializing waveform is applied in the forced initializing operation may be all the discharge cells in the image display area of the panel 10, but, for example, some discharges in the image display area It may be a cell. The same applies to all subfields that perform the forced initialization operation in the following description.

  In the address period Pw1 of the subfield SF1, a negative scan pulse with 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. A positive address pulse having a positive voltage Vd is applied to the electrode Dk.

  A similar address operation is sequentially performed in the order of scan electrodes SC2, SC3, SC4,..., SCn until reaching the discharge cell in the nth row.

  Each voltage of the scan pulse and the address pulse is adjusted so that the address discharge is weaker than the sustain discharge. This is because the light emission due to the address discharge is made lower in luminance than the light emission due to the sustain discharge so as not to hinder the display of an image on the panel 10.

  In sustain period Ps1 of subfield SF1, sustain pulses of the number obtained by multiplying the luminance weight by a predetermined luminance multiple are alternately applied to scan electrodes SC1 to SCn and 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.

  Note that the sustain discharge is a strong discharge and has high emission luminance as compared with the initialization discharge and the address discharge.

  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, and scan electrodes SC1 to SCn are applied. An erasing operation is performed in which an upward ramp waveform voltage that gradually rises from the voltage 0 (V) to the positive voltage Vr is applied.

  As a result, a weak discharge (erase discharge) occurs 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 that falls from a voltage (for example, voltage 0 (V)) that is lower than the discharge start voltage to a 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. An initializing discharge does not occur in a discharge cell in which no sustain discharge has occurred in the sustain period Ps1 of the immediately preceding subfield SF1. 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, the same drive voltage waveform as that in the address period Pw1 and sustain period Ps1 is 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, driving voltage waveforms generated in the coordinate detection subfield will be described with reference to FIG. The coordinate detection subfield is a generic name of the synchronization detection subfield SFo, the proximity y coordinate detection subfield SFy1, the proximity x coordinate detection subfield SFx1, the remote y coordinate detection subfield SFy2, and the remote x coordinate detection subfield SFx2. It is.

  Hereinafter, “y-coordinate detection subfield SFy” is used as a generic term for the proximity y-coordinate detection subfield SFy1 and the remote y-coordinate detection subfield SFy2, and the proximity x-coordinate detection subfield SFx1 and the remote x-coordinate detection subfield are used. “X coordinate detection subfield SFx” is used as a general term for the field SFx2.

  A position indicated by the electronic pen 50 in the image display area (hereinafter also referred to as “position of the electronic pen 50”) is represented by an x coordinate and ay coordinate. The x-coordinate detection subfield SFx and the y-coordinate detection subfield SFy are subfields for detecting the x-coordinate and y-coordinate of the position (positional coordinate) of the electronic pen 50 in the image display area. 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 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 50 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 50 during “proximity use”. The remote y-coordinate detection subfield SFy2 and the remote x-coordinate detection subfield SFx2 are used to detect the position coordinate of the electronic pen 50 when the user uses the electronic pen 50 at a position away from the panel 10. Subfield to use.

  The position indicated by the electronic pen 50 means that the light receiving element 52 or the light receiving element 54 of the electronic pen 50 emits light of an x coordinate detection pattern displayed in the x coordinate detection subfield SFx and is displayed in the y coordinate detection subfield SFy. This is the position in the image display surface where the light emission of the y coordinate detection pattern is detected.

  In the image display system 100 according to the present embodiment, wireless communication is performed between the electronic pen 50 and the drawing device 40. The electronic pen 50 calculates the position coordinates of the electronic pen 50 inside the electronic pen 50 and transmits data of the calculated position coordinates from the electronic pen 50 to the drawing device 40 by wireless communication.

  The synchronization detection subfield SFo is a subfield for the electronic pen 50 to accurately grasp the timing at which the coordinate detection subfield is generated in the image display device 30. The electronic pen 50 receives the light emitted in the synchronization detection subfield SFo, thereby synchronizing with the image display device 30 and generating a signal (coordinate reference signal) serving as a reference for calculating position coordinates with high accuracy. It becomes possible.

  Note that the coordinate detection subfield is not necessarily provided in each field.

  FIG. 5 is a diagram schematically showing an example of a drive voltage waveform applied to each electrode of panel 10 in the coordinate detection sub-field in Embodiment 1 of the present invention.

  The synchronization detection subfield SFo has an initialization period Pio, a write period Pwo, and a synchronization detection period Po.

  In the initialization period Pio, the drive voltage waveform similar to that in the initialization period Pi2 of the subfield SF2 of the image display subfield is applied to each electrode to perform the same selective initialization operation, and thus 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 to generate an address discharge in each discharge cell.

  In the write period Pwo of the present embodiment, as shown in FIG. 5, the scan pulse is applied to all the scan electrodes SC1 to SCn at a time while the write pulse is applied to all the data electrodes D1 to Dm. The address discharge is simultaneously generated in all the discharge cells in the ten image display areas. For example, even in the address operation in which the scan pulse is sequentially applied to each electrode from the scan electrode SC1 to the scan electrode SCn. Good.

  Note that the address discharge generated in the address period Pwo is similar to the address discharge generated in the address period Pw1 and is weaker than the sustain discharge. However, all the discharge cells in the image display area are simultaneously discharged. Since the address discharge occurs at the time, the light emission luminance is higher than the light emission generated in the address period Pw1.

  After address discharge has been generated in all the discharge cells in the image display area of panel 10, voltage 0 (V) is applied to 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 from time to0 to time To0. During this period, after the last address discharge has occurred in the discharge cells, a state in which no discharge occurs is maintained. Time to0 is the time when the scan pulse for generating the last address discharge is applied to scan electrode SCn.

  In this embodiment, the time To0 is set to a time longer than any of the time To1, the time To2, and the time To3 described later. In the present embodiment, the time To0 is about 50 μsec, for example.

  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 50.

  In the example shown in FIG. 5, 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 synchronization detection discharges are generated in all the discharge cells in the image display area of the panel 10, and the entire image display surface of the panel 10 emits light four times (emission for synchronization detection).

  As described above, in the synchronization detection period Po, a plurality of synchronization detection discharges are 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). Times (for example, four times), and light emission for synchronization detection is caused a plurality of times.

  This 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.

  The electronic pen 50 receives a plurality of times (for example, four times) of sync detection light emission generated at predetermined time intervals (for example, the time To1, the time To2, and the time To3). A signal (a signal serving as a reference when calculating the position coordinates (x coordinate, y coordinate) of the electronic pen 50) is created.

  In the synchronization detection subfield SFo, the entire image display surface of the panel 10 emits light all at the same timing, so the electronic pen 50 has the same timing no matter where it is received in the image display area of the panel 10. Can receive light.

  In the present embodiment, for example, the time To1 is about 40 μsec, the time To2 is about 20 μsec, and the time To3 is about 30 μsec. However, the present invention is not limited to the above-described numerical values at times To0 to To3. Each time may be appropriately set according to the specifications of the image display system 100 or the like.

  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. . Thereby, a weak erasure discharge is generated in all the discharge cells in the image display area of the panel 10.

  Subsequently, a proximity y-coordinate detection subfield SFy1 and a proximity x-coordinate detection subfield SFx1 are generated.

  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.

  In the synchronization detection period Po, synchronization detection discharges are generated in all the discharge cells in the image display area of the panel 10, and in the initialization period Piy, weak initialization discharges are generated in all the discharge cells, and all of them are generated. The wall voltage of the discharge cells 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 y-coordinate detection period Py1 of the proximity y-coordinate detection subfield SFy1, the y-coordinate is simultaneously applied to the preset “first number” of scanning electrodes 12 while the y-coordinate detection voltage Vdy is applied to the data electrodes D1 to Dm. The operation of applying the detection pulse is sequentially performed on scan electrodes SC1 to SCn. In the present embodiment, the “first number” is, for example, “1”, but the “first number” may be two or more.

  In the y coordinate detection period Py1 starting at time ty01, the voltage Ve is applied to the sustain electrodes SU1 to SUn, the voltage 0 (V) is applied to the data electrodes D1 to Dm, and the voltage Vc is applied to the scan electrodes SC1 to SCn.

  Next, after a period Ty01 from time ty01, a positive y-coordinate detection voltage Vdy is applied to the data electrodes D1 to Dm, and a negative y-coordinate detection pulse of the voltage Vay is applied to the scan electrode SC1 in the first row. . In FIG. 5, the pulse width of this y coordinate detection pulse is shown as Ty11.

  Discharge occurs in the discharge cells in the first row at the intersections 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. Hereinafter, this discharge is also referred to as “y-coordinate detection discharge”.

  This y-coordinate detection discharge is the same discharge as the address discharge, is weaker than the sustain discharge, and has low emission luminance.

  In this way, discharge occurs in all the discharge cells constituting the first row, and these discharge cells emit light all at once. This light emission is a light emission for y-coordinate detection when the electronic pen 50 is used in proximity.

  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 this embodiment, the discharge cell row and the pixel row are substantially the same, and in the above-described operation, the first pixel row (first discharge cell row) emits light all at once.

  The same operation is performed in the order of scan electrode SC2, scan electrode SC3,..., Scan electrode SCn with the y coordinate detection voltage Vdy being applied to the data electrodes D1 to Dm until the discharge cell in the nth row is reached. Then, light emission for y coordinate detection is sequentially generated in each pixel row (discharge cell row) from the second row to the nth row (for example, 1080th row).

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

  Hereinafter, one light emission line having a “first number” width extended in the x coordinate direction and generated in the y coordinate detection period Py1 is also referred to as a “first light emission line”. That is, in the proximity y-coordinate detection pattern generated in the y-coordinate detection period Py1, the first emission line extended in the x-coordinate direction sequentially moves in the y-coordinate direction (from the first line to the nth line of the image display area). Each pixel row sequentially emits light, for example, every row).

  When the proximity y-coordinate detection pattern is displayed on the panel 10 in the y-coordinate detection period Py1, each pixel row from the first row to the n-th row in the image display area sequentially emits light, for example, for each row. The timing at which the electronic pen 50 receives this light emission varies depending on where in the image display area of the panel 10 the front end of the electronic pen 50 is in contact. Therefore, when the electronic pen 50 is used in proximity, the y coordinate of the position coordinate (x, y) of the electronic pen 50 in the image display area is detected by detecting the timing at which the electronic pen 50 receives the first light emission line. can do.

  In the present embodiment, the time during which the y coordinate detection pulse is applied to each of scan electrodes SC1 to SCn in y coordinate detection period Py1 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 sustaining period Ps1 of the subfield SF1 is performed. Thereby, a weak erasure discharge is generated in all the discharge cells in the image display area of the panel 10.

  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, the selection initialization operation similar to the initialization period Piy of the proximity y coordinate detection subfield SFy1 is performed while the voltage 0 (V) is applied to the sustain electrodes SU1 to SUn.

  In the y coordinate detection period Py1, since y coordinate detection discharge is generated in all the discharge cells in the image display area of the panel 10, initialization discharge is generated in all the discharge cells in the initialization period Pix. The wall voltage of the 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 x-coordinate detection period Px1 of the proximity x-coordinate detection subfield SFx1, the x-coordinate is simultaneously applied to the “second number” of data electrodes 22 set in advance while the x-coordinate detection voltage Vax is applied to the scan electrodes SC1 to SCn. The operation of applying the detection pulse is sequentially performed on the data electrodes D1 to Dm. In the present embodiment, the “second number” is, for example, “3”, but the “second number” may be a number other than three.

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

  Next, after a period Tx01 from time tx01, a positive x coordinate detection pulse of voltage Vdx of the voltage Vdx is applied to the data electrodes D1 to D3 in the first to third columns while the x coordinate detection voltage Vax is applied to the scan electrodes SC1 to SCn. Apply. In FIG. 5, the pulse width of this x coordinate detection pulse is shown as Tx11.

  The data electrodes D1 to D3 correspond to a red discharge cell, a green discharge cell, and a blue discharge cell constituting one pixel, and this pixel is, for example, a pixel arranged at the left end of the image display area. It is.

  Discharge occurs in the discharge cells in the first to third columns at the intersections between 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. . Hereinafter, this discharge is also referred to as “x coordinate detection discharge”.

  The x-coordinate detection discharge is the same discharge as the address discharge, is weaker than the sustain discharge, and has low emission luminance.

  In this way, discharge occurs in all the pixels constituting the first column, and these pixels emit light all at once. This light emission becomes light emission for x-coordinate detection when the electronic pen 50 is used in proximity.

  Hereinafter, an aggregate of discharge cells constituting one column is referred to as a “discharge cell column”. Further, an assembly of discharge cells (pixel column) composed of three adjacent discharge cell columns is referred to as a “pixel column”. In the above-described operation, the first pixel column (that is, the first, second, and third discharge cell columns) emits light all at once.

  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 being applied to scan electrodes SC1 to SCn. Each of the three data electrodes 22 is sequentially performed until reaching the m-th discharge cell, and light emission for x coordinate detection is performed on each pixel column from the second column to the last column (for example, 1920 column). Generate sequentially.

  Thus, in the x coordinate detection period Px1 of the proximity x coordinate detection subfield SFx1, one vertical line that emits light (that is, one pixel column that emits light) is the left end (one column) of the image display area of the panel 10. A pattern (proximity x coordinate detection pattern) that sequentially moves one column at a time from the pixel column of the eye) to the right end (m / 3 pixel column) is displayed. In other words, this proximity x-coordinate detection pattern is a pattern in which each pixel column from the first column to the last column of the image display region sequentially emits light for each column. In other words, in this proximity x-coordinate detection pattern, the three discharge cell columns adjacent to each other emit light sequentially in three columns from the left end (first column) to the right end (m column) of the image display area. It is a pattern.

  Hereinafter, one light emission line having a width of “second number” extended in the y coordinate direction and generated in the x coordinate detection period Px1 is also referred to as “second light emission line”. That is, in the proximity x-coordinate detection pattern generated in the x-coordinate detection period Px1, the second light emission line extended in the y-coordinate direction sequentially moves in the x-coordinate direction (m / 3 columns from the first column of the image display area). For example, each pixel column up to the eye sequentially emits light for each column).

  When the proximity x-coordinate detection pattern is displayed on the panel 10 in the x-coordinate detection period Px1, each pixel column from the first column to the last column in the image display area sequentially emits light, for example, for each column. The timing at which the electronic pen 50 receives this light emission varies depending on where in the image display area of the panel 10 the front end of the electronic pen 50 is in contact. Therefore, when the electronic pen 50 is used in proximity, the x coordinate of the position coordinate (x, y) of the electronic pen 50 in the image display area is detected by detecting the timing at which the electronic pen 50 receives the second light emission line. Detected.

  In the present embodiment, the time during which 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 in the erasing period Pey of the proximity y coordinate detection subfield SFy1 is performed. Thereby, a weak erasure discharge is generated in all the discharge cells in the image display area of the panel 10.

  Subsequently, a remote y coordinate detection subfield SFy2 and a remote x coordinate detection subfield SFx2 are 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 initialization period Piy, the same selective initialization operation as in the initialization period Piy of the proximity y coordinate detection subfield SFy1 is performed. Thereby, the wall voltage of all the discharge cells in the image display area of the panel 10 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 y-coordinate detection period Py2 of the remote y-coordinate detection subfield SFy2, the y-coordinate is simultaneously applied to the preset “third number” of scanning electrodes 12 while the y-coordinate detection voltage Vdy is applied to the data electrodes D1 to Dm. The operation of applying the detection pulse is sequentially performed on scan electrodes SC1 to SCn. The “third number” is a numerical value larger than the “first number” in the y coordinate detection period Py1 of the proximity y coordinate detection subfield SFy1, and in the present embodiment, the “third number” is, for example, “ “8” is eight times the “first number”, but the “third number” may be a number other than eight.

  In the y coordinate detection period Py2 starting at time ty02, the voltage Ve is applied to the sustain electrodes SU1 to SUn, the voltage 0 (V) is applied to the data electrodes D1 to Dm, and the voltage Vc is applied to the scan electrodes SC1 to SCn.

  Next, after a period Ty02 from time ty02, positive y-coordinate detection voltage Vdy is applied to data electrodes D1 to Dm, and negative y-coordinate detection of voltage Vay is applied to scan electrodes SC1 to SC8 in the first to eighth rows. Apply pulses simultaneously. In FIG. 5, the pulse width of this y coordinate detection pulse is indicated as Ty12.

  In the discharge cells in the first to eighth rows 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, the y coordinate detection discharge is performed. Occurs.

  In this way, discharge occurs in the eight discharge cell rows (eight pixel rows) constituting the first to eighth rows, and these discharge cell rows (pixel rows) emit light all at once. And this light emission becomes light emission for y coordinate detection when the electronic pen 50 is used remotely.

  This y-coordinate detection discharge is the same discharge as the address discharge, is weaker than the sustain discharge, and has low emission luminance. However, since y-coordinate detection discharges are generated simultaneously in the eight discharge cell rows (pixel rows), the light emission is caused by the y-coordinate detection discharge generated in the y-coordinate detection period Py1 of the proximity y-coordinate detection subfield SFy1. Brightness is higher than light emission.

  The same operation is performed with n rows 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. Sequentially performed until reaching the discharge cell of the eye.

  As a result, in the y coordinate detection period Py2 of the remote y coordinate detection subfield SFy2, one horizontal line that emits light (that is, eight pixel rows that emit light) corresponds to the upper end (one row) of the image display area of the panel 10. A pattern (remote y-coordinate detection pattern) that sequentially moves by 8 lines from the lower pixel (the nth pixel line) to the lower end (nth pixel line) is displayed.

  Hereinafter, one light emission line having a width of “third number” extended in the x coordinate direction and generated in the y coordinate detection period Py2 is also referred to as “third light emission line”. That is, in the remote y-coordinate detection pattern generated in the y-coordinate detection period Py2, the third emission line extended in the x-coordinate direction sequentially moves in the y-coordinate direction (from the first line to the nth line of the image display area). Each pixel row sequentially emits light, for example, every 8 rows).

  The third light emitting line is a light emitting line having a wider width and higher luminance than the first light emitting line for proximity described above. Therefore, the distance to the panel 10 where the electronic pen 50 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.

  When the remote y-coordinate detection pattern is displayed on the panel 10 in the y-coordinate detection period Py2, each pixel row from the first row to the n-th row in the image display area sequentially emits light, for example, every eight rows. The timing at which the electronic pen 50 receives this light emission varies depending on where in the image display area of the panel 10 the position coordinate is. Therefore, when the electronic pen 50 is used remotely, the y coordinate of the position coordinate (x, y) of the electronic pen 50 in the image display area is detected by detecting the timing at which the electronic pen 50 receives the third light emission line. can do.

  In the present embodiment, the time for applying the y coordinate detection pulse to each of 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. Thereby, a weak erasure discharge is generated in all the discharge cells in the image display area of the panel 10.

  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, the same selective initialization operation as the initialization period Pix of the proximity x coordinate detection subfield SFx1 is performed. Thereby, the wall voltage of all the discharge cells in the image display area of panel 10 is adjusted to the wall voltage suitable for the remote x-coordinate detection pattern display operation in the subsequent x-coordinate detection period Px2.

  In the x-coordinate detection period Px2 of the remote x-coordinate detection subfield SFx2, the x-coordinate is simultaneously applied to the preset “fourth number” of data electrodes 22 while the x-coordinate detection voltage Vax is applied to the scan electrodes SC1 to SCn. The operation of applying the detection pulse is sequentially performed on the data electrodes D1 to Dm. The “fourth number” is a numerical value larger than the “second number” in the x-coordinate detection period Px1 of the proximity x-coordinate detection subfield SFx1, and in the present embodiment, the “fourth number” is, for example, “ “24” is eight times the “second number”, but the “fourth number” may be a number other than 24.

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

  Next, after a period Tx02 from time tx02, a positive x coordinate detection pulse of voltage Vdx is applied to the data electrodes D1 to D24 in the 1st to 24th columns while the x coordinate detection voltage Vax is applied to the scan electrodes SC1 to SCn. Apply. In FIG. 5, the pulse width of this x coordinate detection pulse is shown as Tx12.

  In the discharge cells in the 1st to 24th columns 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, the x coordinate detection discharge is performed. Occurs.

  In this way, discharge occurs in the eight pixel columns (24 discharge cell columns) constituting the first to eighth columns, and these pixel columns emit light all at once. This light emission becomes light emission for x-coordinate detection when the electronic pen 50 is used remotely.

  The x-coordinate detection discharge is the same discharge as the address discharge, is weaker than the sustain discharge, and has low emission luminance. However, since the x-coordinate detection discharge is generated all at once in the eight pixel columns (24 discharge cell columns), the light emission is generated in the x-coordinate detection period Px1 of the proximity x-coordinate detection subfield SFx1. The brightness is higher than the emission of the detection discharge.

  The same operation is performed in the order of the data electrodes D25 to D48, the data electrodes D49 to D72,..., The data electrodes Dm-23 to Dm, with the x coordinate detection voltage Vax being applied to the scan electrodes SC1 to SCn. The process is sequentially performed until the discharge cell reaches the eye.

  Thereby, in the x-coordinate detection period Px2 of the remote x-coordinate detection subfield SFx2, one vertical line that emits light (that is, eight pixel columns that emit light) corresponds to the left end portion (1 of the image display area of the panel 10). A pattern (remote x-coordinate detection pattern) is displayed that sequentially moves by 8 columns from the pixel column of the column to the right end (m / 3 pixel column). That is, this remote x-coordinate detection pattern is a pattern in which each pixel column from the first column to the last column in the image display area sequentially emits light every eight columns. In other words, in this remote x coordinate detection pattern, 24 discharge cell columns adjacent to each other emit light sequentially 24 columns from the left end (first column) to the right end (m column) of the image display area. Pattern.

  Hereinafter, one light emission line having a “fourth number” width extending in the y coordinate direction and generated in the x coordinate detection period Px2 is also referred to as a “fourth light emission line”. That is, in the remote x-coordinate detection pattern generated in the x-coordinate detection period Px2, the fourth emission line extended in the y-coordinate direction sequentially moves in the x-coordinate direction (m / 3 columns from the first column of the image display area). Each pixel column up to the eye sequentially emits light every 8 columns, for example).

  The fourth light emitting line is a light emitting line having a wider width and higher luminance than the above-described second light emitting line for proximity. Therefore, the distance to the panel 10 where the electronic pen 50 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.

  When the remote x-coordinate detection pattern is displayed on the panel 10 in the x-coordinate detection period Px2, each pixel column from the first column to the last column in the image display area sequentially emits light, for example, every eight columns. The timing at which the electronic pen 50 receives this light emission varies depending on where in the image display area of the panel 10 the position coordinate is. Therefore, when the electronic pen 50 is used remotely, the x coordinate of the position coordinate (x, y) of the electronic pen 50 in the image display area is detected by detecting the timing at which the electronic pen 50 receives the fourth light emission line. Is done.

  In the present embodiment, the time during which the x-coordinate detection pulse is applied to each of the data electrodes D1 to Dm in the x-coordinate detection period Px2 is Tx12. This Tx12 is, for example, about 1 μsec.

  In the erasing period Pex of the remote x-coordinate detection subfield SFx2, the same erasing operation as that performed in the erasing period Pex of the proximity x-coordinate detection subfield SFx1 is performed. Thereby, a weak erasure discharge is generated in all the discharge cells in the image display area of the panel 10.

  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 the present embodiment, in the proximity y coordinate detection subfield SFy1, the y coordinate detection pattern with relatively low emission luminance but relatively high position coordinate calculation accuracy is displayed on the panel 10. In the remote y-coordinate detection subfield SFy2, the y-coordinate detection pattern with relatively high positional coordinate calculation accuracy but relatively high emission luminance is displayed on the panel 10. Similarly, in the proximity x-coordinate detection subfield SFx1, an x-coordinate detection pattern with relatively low emission luminance but relatively high position coordinate calculation accuracy is displayed on the panel 10, and the remote x-coordinate detection subfield SFx2 is displayed. Then, the x-coordinate detection pattern with relatively high position coordinate calculation accuracy but relatively high light emission luminance is displayed on the panel 10.

  When the electronic pen 50 is used remotely, the position coordinates can be calculated even in the electronic pen 50 located away from the panel 10 by detecting the third light emission line and the fourth light emission line. Is possible.

  Accordingly, when the electronic pen 50 is used in contact with the panel 10 (or used at a short distance just before contact), the light emission generated in the proximity y coordinate detection subfield SFy1 and the proximity x coordinate detection subfield SFx1. As a detection target, the position coordinates can be calculated with relatively high accuracy. Further, when the electronic pen 50 is used remotely, the light emitted from the remote y-coordinate detection subfield SFy2 and the remote x-coordinate detection subfield SFx2 having a relatively high light emission luminance is detected, thereby separating from the panel 10. It is possible to calculate the position coordinates even in the electronic pen 50 located at the position (for example, about 8 m).

  Note that three or more y-coordinate detection subfields SFy and three or more x-coordinate detection subfields SFx having different emission luminances may be generated based on the same idea as described above.

  In this embodiment, the voltage values applied to the electrodes 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). 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 values such as the voltage value and the gradient described above are merely examples, and the voltage value and the gradient can be optimally set based on the discharge characteristics of the panel 10 and the specifications of the image display device 30. desirable.

  The time To0 is set to a time longer than any of the times To1, To2 and To3 because the electronic pen 50 synchronizes the light emission due to the address discharge generated in the address period Pwo of the synchronization detection subfield SFo. This is to prevent erroneous recognition of light emission due to the detected discharge.

  Next, the electronic pen 50 will be described.

  The electronic pen 50 is formed in a rod shape, and the user brings the tip of the electronic pen 50 into direct contact with the panel 10 (proximity use) or from a position away from the panel 10 (remote use). It is used for inputting characters or drawings by handwriting (pen function) or displaying a cursor (pointer function) in the image display area of the display device 30. The electronic pen 50 detects the position coordinates by receiving light emitted from the panel 10 by the coordinate detection subfield. As described above, the position coordinate is detected by the electronic pen 50 receiving the light emission of the y coordinate detection pattern displayed on the panel 10 to calculate the y coordinate, and the light emission of the x coordinate detection pattern displayed on the panel 10. Is received and the x coordinate is calculated.

  As shown in FIG. 1, the electronic pen 50 includes light receiving elements 52 and 54, a contact switch 53, a plurality of (or a single) manual switch 83, a synchronization detection unit 56, a coordinate calculation unit 57, a transmission unit 58, and an attachment detection switch. 86, and a distance determination unit 91.

  Although not shown in FIG. 1, the electronic pen 50 also has a power switch, a pilot lamp, 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 light emission / non-light emission or switching of the light emission color.

  The first light receiving element 52 is provided at one end of the electronic pen 50 in the longitudinal direction (hereinafter referred to as “proximity side end”), and the second light receiving element 54 is disposed in the longitudinal direction of the electronic pen 50. It is provided at the other end (hereinafter referred to as “remote side end”). The light receiving elements 52 and 54 receive light emitted on the image display surface of the image display device 30 and convert it into an electrical signal (light reception signal). This light reception signal changes according to the amount of light received, and the light reception signal increases as the light amount increases. These received light signals are output to the synchronization detection unit 56 and the coordinate calculation unit 57. The light reception signal output from the light receiving element 54 is input to the distance determination unit 91. In the present embodiment, the position coordinate (x, y) of the electronic pen 50 is a position where the light receiving element 52 or the light receiving element 54 receives light emitted on the image display surface of the image display device 30.

  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 (close side), and whether the close side end of the electronic pen 50 is in contact with the image display surface of the image display device 30. Is detected. The contact switch 53 is turned on and outputs S1 = "1" if the near end of the electronic pen 50 is in contact with the panel 10, and is turned off if it is not in contact with S1 = "0". Output.

  One of the manual switches 83 is used as a drawing switch for remote use. The manual switch 83 is turned on and off by the user. When the manual switch 83 is on, S1 '= "1" is output, and when it is off, S1' = "0" is output. The other one of the manual switches 83 can arbitrarily switch the drawing mode S0 (for example, the color of the line used for drawing, the thickness of the line, the type of line, etc.) by the user's operation. Other manual switches 83 include, for example, one having a function as a selection button and one having a function of enlarging / reducing a display image.

  The electronic pen 50 can attach the attachment 80 provided with the condensing lens 84 to a remote side end part so that attachment or detachment is possible. By attaching the attachment 80, the light receiving element 54 of the electronic pen 50 can receive light emitted from the coordinate detection subfield displayed on the panel 10 even at a position several meters away from the image display device 30. . Accordingly, the electronic pen 50 can be used (remotely used) even from a position several meters (for example, about 8 m) away from the image display device 30.

  The attachment detection switch 86 is turned on when the attachment 80 is attached to the electronic pen 50 and outputs S2 = “1”, and if not attached, the attachment detection switch 86 is turned off and S2 = “0”. Is output.

  Note that instead of the attachment detection switch 86, one of the manual switches 83 may be used to switch S2 = “1” or “0”.

  As described above, the electronic pen 50 according to the present embodiment is used in such a manner that the close end provided with the light receiving element 52 is in direct contact with the image display surface of the image display device 30 (or at a position relatively close to the panel 10). Use “proximity use” and attach the attachment 80 to the remote end provided with the light receiving element 54, and direct the condenser lens 84 toward the panel 10, and use it at a position away from the image display surface of the image display device 30. It is possible to use two types of “remote use”.

  When the electronic pen 50 is used in proximity, the light emission of the proximity y coordinate detection subfield SFy1 and the proximity x coordinate detection subfield SFx1 received by the light receiving element 52 is used for calculating the position coordinates, and the electronic pen 50 is used. When using remotely, the light emission of the remote y coordinate detection subfield SFy2 and the remote x coordinate detection subfield SFx2 received by the light receiving element 54 through the condenser lens 84 of the attachment 80 is used for calculating the position coordinates.

  When the attachment 80 is not attached to the electronic pen 50, the remote side end provided with the light receiving element 54 may be used for, for example, an “erase function” for erasing characters and drawings.

  The synchronization detection unit 56 detects light emission for synchronization detection (light emission caused by synchronization detection discharge) generated in the synchronization detection period Po of the synchronization detection subfield SFo based on the light receiving signal output from the light receiving element 52 or the light receiving element 54. To do. Specifically, the synchronization detection unit 56 uses a timer (not shown) included in the synchronization detection unit 56 to measure the occurrence intervals of a plurality of (for example, five times) light emission. Then, whether or not the occurrence interval matches a predetermined time interval (for example, time To0, To1, To2, To3) is determined based on a plurality of threshold values (for example, time It is determined by comparing the measured time intervals with threshold values corresponding to To0, To1, To2, and To3.

  Then, the synchronization detection unit 56 creates a coordinate reference signal based on one of the continuous multiple times (for example, five times) of light emission. For example, the coordinate reference signal is generated based on the light emission generated at the time to1 in the synchronization detection period Po of the synchronization detection subfield SFo. The time to1 is a time at which 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 operation of the synchronization detection unit 56 will be described with reference to FIGS.

  FIG. 6 is a diagram schematically showing 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 Embodiment 1 of the present invention.

  FIG. 6 shows an example of the position coordinate calculation operation of the electronic pen 50 when the electronic pen 50 is used while being brought into contact with (or in close proximity to) the panel 10 at the proximity end (tip on the side where the light receiving element 52 is provided). Indicates.

  FIG. 7 is a diagram schematically showing an example of a position coordinate detection operation when the electronic pen 50 is used remotely in the image display system 100 according to Embodiment 1 of the present invention.

  In FIG. 7, the electronic pen 50 is used when the attachment 80 is attached to the remote side end of the electronic pen 50 (the tip on the side where the light receiving element 54 is provided) and the electronic pen 50 is used at a position away from the panel 10. An example of the position coordinate calculation operation is shown.

  6 and 7, the drive voltage waveform applied to each of the scan electrodes SC1 and SCn and the data electrodes D1 and Dm, the coordinate reference signal input to the coordinate calculation unit 57, and the distance detection input to the distance determination unit 91 are shown. The signal and the light reception signal output from the light receiving element 52 (or the light receiving element 54) are shown. The drive voltage waveforms shown in FIGS. 6 and 7 are the same as the drive voltage waveforms shown in FIGS.

  In the image display device 30 according to the present embodiment, time Toy1 from time to1 to time ty01, time Tox1 from time to1 to time tx01, time Toy2 from time to1 to time ty02, time Tox2 from time to1 to time tx02 Each of these is predetermined.

  Therefore, if the synchronization detection unit 56 can specify the time to1, the coordinate reference signal having rising edges at the time ty01 and the time tx01 shown in FIG. 6 and the rising at the time ty02 and the time tx02 shown in FIG. A coordinate reference signal with an edge can be generated and output to the coordinate calculation unit 57.

  At time to1, as described above, the synchronization detecting unit 56 emits five consecutive light emission intervals in which the light emission intervals are time To0, time To1, time To2, and time To3 (output from the light receiving element 52 based on these light emission). Is detected by detecting the received light signal).

  The synchronization detection unit 56 compares the light reception signal with a preset light reception threshold th1 and calculates a differential value for the light reception signal equal to or greater than the light reception threshold th1 to generate a local peak. Is detected. Thus, each time and each time is detected.

  In addition, there is a time difference due to the discharge characteristics between the time when the voltage for generating 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. The time difference may be measured in advance and used as an offset value for correcting each time.

  When the attachment 80 is not attached to the electronic pen 50 and the attachment detection switch 86 outputs S2 = “0”, the synchronization detection unit 56 and the proximity y coordinate detection subfield SFy1 and the proximity A coordinate reference signal is generated so that the position coordinates can be calculated based on the light emission of the x-coordinate detection subfield SFx1. That is, as shown in FIG. 6, time ty01 (start time of the y coordinate detection period Py1 of the proximity y coordinate detection subfield SFy1) and time tx01 (start of the x coordinate detection period Px1 of the proximity x coordinate detection subfield SFx1) A coordinate reference signal having a rising edge at each time) is generated and output to the subsequent coordinate calculation unit 57.

  When the attachment 80 is attached to the electronic pen 50 and the attachment detection switch 86 outputs S2 = “1”, the synchronization detection unit 56 detects the remote y coordinate detection subfield SFy2 and the remote x A coordinate reference signal is generated so that the position coordinates can be calculated based on the light emission of the coordinate detection subfield SFx2. That is, as shown in FIG. 7, time ty02 (start time of the y coordinate detection period Py2 of the remote y coordinate detection subfield SFy2) and time tx02 (start of the x coordinate detection period Px2 of the remote x coordinate detection subfield SFx2) A coordinate reference signal having a rising edge at each time) is generated and output to the subsequent coordinate calculation unit 57.

  As described above, the synchronization detection unit 56 identifies the time to1 based on the light emission for synchronization detection, and the coordinate reference signal having the rising edges at each of the time ty01 and the time tx01 with respect to the time to1, or the time ty02. And a coordinate reference signal having rising edges at time tx02.

  Further, in the synchronization detection unit 56 in the present embodiment, when the attachment 80 is attached to the electronic pen 50 and the attachment detection switch 86 outputs S2 = “1”, as shown in FIG. “Distance detection signal” for detecting the light emission of the proximity y coordinate detection pattern generated in the proximity y coordinate detection subfield SFy1 and the light emission of the proximity x coordinate detection pattern generated in the proximity x coordinate detection subfield SFx1 Is generated based on the time to1 and is output to the distance determination unit 91 in the subsequent stage. This distance detection signal is a signal that permits the distance determination unit 91 to accept the received light signal, and is, for example, a signal that becomes Hi during the y coordinate detection period Py1 and the coordinate detection period Px1, and becomes Lo.

  However, when the attachment 80 is not attached to the electronic pen 50 and the attachment detection switch 86 outputs S2 = "0", the synchronization detection unit 56 outputs a distance detection signal as shown in FIG. Keep it at Lo. Therefore, when S2 = “0”, the distance determination unit 91 does not accept a light reception signal.

  In addition, the synchronization detection unit 56 generates a reset signal (not shown) if it does not detect the light emission for synchronization detection generated in the synchronization detection period Po for a predetermined time (for example, 0.25 seconds) or longer. Specifically, the synchronization detection unit 56 measures a time during which a light reception signal that matches a predetermined time interval (for example, times To0, To1, To2, To3) whose generation interval is determined in advance cannot be detected, and the measurement time Is compared to a reset time threshold (eg, 0.25 seconds). And if the measurement time becomes more than a reset time threshold value, the synchronous detection part 56 will generate and output a reset signal. However, if the sync detection unit 56 receives the sync detection light emission, it immediately cancels the reset signal.

  Note that in this embodiment, an example in which the coordinate reference signal and the distance detection signal are generated based on the time to1 is described. However, the coordinate reference signal and the distance detection signal are generated at the time to2, the time to3, or the time It may be generated based on to4.

  Note that the coordinate reference signal is not limited to the above-mentioned signal. When the light receiving element 52 or the light receiving element 54 receives light emission by the y coordinate detection pattern and light emission by the x coordinate detection pattern, the time is specified. Any signal can be used as long as the signal can be used as a reference.

  The coordinate calculation unit 57 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).

  Based on the coordinate reference signal and the light reception signal, the coordinate calculation unit 57 selectively extracts, from the light reception signal, a signal indicating the light emission of the y coordinate detection pattern and a signal indicating the light emission of the x coordinate detection pattern. The position coordinates (x, y) of the pen 50 are calculated.

  Specifically, when the attachment 80 is not attached to the electronic pen 50 and the attachment detection switch 86 outputs S2 = “0”, the coordinate calculation unit 57, as shown in FIG. Based on the signal, a time Tyy1 from time ty01 to time ty1 when light emission is first received by the light receiving element 52 after time ty01 is measured with a counter. Then, the time Ty01 (time from the time ty01 until the first proximity y coordinate detection pulse is generated) is subtracted from the time Tyy1 in the arithmetic circuit, and the subtraction result is the time Ty11 (pulse width of the proximity y coordinate detection pulse). Divide by. In this way, the y coordinate of the position of the electronic pen 50 in the image display area when used in proximity is calculated.

  Next, based on the coordinate reference signal, the coordinate calculation unit 57 measures a time Txx1 from time tx01 to time txx1 at which light is first received by the light receiving element 52 after time tx01. Then, the time Tx01 (time from the time tx01 until the first proximity x-coordinate detection pulse is generated) is subtracted from the time Txx1 in the arithmetic circuit, and the subtraction result is time Tx11 (pulse width of the proximity x-coordinate detection pulse). Divide by. In this way, the x coordinate of the position of the electronic pen 50 in the image display area when used in proximity is calculated.

  When the attachment 80 is attached to the electronic pen 50 and the attachment detection switch 86 outputs S2 = “1”, the coordinate calculation unit 57 starts from time ty02 based on the coordinate reference signal as shown in FIG. After the time ty02, the time Tyy2 until the time ty2 at which light emission is first received by the light receiving element 54 is measured by the counter. Then, the time Ty02 (time from the time ty02 until the first remote y-coordinate detection pulse is generated) is subtracted from the time Tyy2 in the arithmetic circuit, and the subtraction result is time Ty12 (pulse width of the remote y-coordinate detection pulse). Divide by. In this way, the y coordinate of the position of the electronic pen 50 in the image display area during remote use is calculated.

  Next, based on the coordinate reference signal, the coordinate calculation unit 57 measures, with a counter, a time Txx2 from time tx02 to time txx2 when light is first received by the light receiving element 54 after time tx02. Then, the time Tx02 (time from the time tx02 until the first remote x coordinate detection pulse is generated) is subtracted from the time Txx2 in the arithmetic circuit, and the subtraction result is time Tx12 (pulse width of the remote x coordinate detection pulse). Divide by. In this way, the x coordinate of the position of the electronic pen 50 in the image display area during remote use is calculated.

  The time tyy1 or the time tyy2 is a time when the light receiving element 52 or the light receiving element 54 of the electronic pen 50 receives light emitted from the panel 10 by the y coordinate detection pattern, and the time txx1 or the time txx2 is a light reception of the electronic pen 50. This is the time when the element 52 or the light receiving element 54 receives the light emitted from the panel 10 by the x coordinate detection pattern.

  The coordinate calculation unit 57 outputs the position coordinates (x, y) of the electronic pen 50 calculated in this way to the transmission unit 58.

  Note that the method of calculating the position coordinates (x, y) of the electronic pen 50 in the coordinate calculation unit 57 is not limited to the calculation method described above. For example, a timer that operates at a time interval corresponding to the pulse width of the y coordinate detection pulse and the pulse width of the x coordinate detection pulse is used, and the count value of the timer is configured to be the y coordinate and the x coordinate as they are. The position coordinates may be calculated by a technique.

  The distance determination unit 91 outputs the distance detection signal output from the synchronization detection unit 56 and the light receiving element 54 when the attachment 80 is attached to the electronic pen 50 and the attachment detection switch 86 outputs S2 = “1”. The distance from the electronic pen 50 to the panel 10 is determined based on the received light signal.

  Specifically, as shown in FIG. 7, the distance determination unit 91 accepts a light reception signal output from the light receiving element 54 during a period when the distance detection signal is Hi, and sets the light reception signal to a distance threshold Th2 set in advance. Compare with If the light reception signal is greater than or equal to the distance threshold Th2, it is determined that the distance from the electronic pen 50 to the panel 10 is relatively close, and S3 = "1" is output, and the light reception signal is less than the distance threshold Th2. If so, it is determined that the distance from the electronic pen 50 to the panel 10 is relatively long, and S3 = "0" is output.

  As described above, the light reception signal output from the light receiving element 54 during the period when the distance detection signal is Hi is used to emit the proximity y coordinate detection pattern generated in the y coordinate detection period Py1 of the proximity y coordinate detection subfield SFy1. This is a light reception signal based on the light emission of the proximity x coordinate detection pattern generated in the x coordinate detection period Px1 of the proximity x coordinate detection subfield SFx1.

  The light emission of the proximity y coordinate detection pattern has lower luminance than the light emission of the remote y coordinate detection pattern, and the light emission of the proximity x coordinate detection pattern has a lower luminance than the light emission of the remote x coordinate detection pattern. Therefore, the distance between the panel 10 and the electronic pen 50 within the distance range in which the light reception signal of the remote y coordinate detection pattern and the light reception signal of the remote x coordinate detection pattern can be received by the light reception threshold th1 or more is used. There is a distance at which the received light signal by the light emission of the y coordinate detection pattern and the light emission of the proximity x coordinate detection pattern is less than the distance threshold Th2. Using this fact, it is determined whether the distance between the electronic pen 50 and the panel 10 is a distance at which the light reception signal is greater than or equal to the distance threshold Th2 or a distance at which the light reception signal is less than the distance threshold Th2. be able to.

  The distance determination unit 91 according to the present embodiment performs S3 = "0" when both the light reception signal due to the light emission of the proximity y coordinate detection pattern and the light reception signal due to the light emission of the proximity x coordinate detection pattern are less than the distance threshold Th2. In other cases, S3 = "1" is output. For example, S3 = "0" is output when at least one is less than the distance threshold Th2, and S3 = "1" is output otherwise. You may comprise.

  In the present embodiment, the light receiving threshold th1 is set so that the position coordinates can be calculated even when the electronic pen 50 is about 8 m away from the panel 10 when the electronic pen 50 is used remotely. The threshold value Th2 is set so that S3 = “0” when the electronic pen 50 is separated from the panel 10 by 2 m or more. However, in the present invention, each threshold value is not limited to these numerical values, and each numerical value may be appropriately set according to the specification of the image display system 100 or the like.

  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. Then, a unique identification number (ID) individually assigned to the electronic pen 50, a drawing mode S0 of the electronic pen 50 (for example, a line color used for drawing, a line thickness, a line type, etc.), a contact switch 53, state S1 of the manual switch 83, state S2 of the attachment detection switch 86, determination result S3 of the distance from the electronic pen 50 to the panel 10, reset signal, position of the electronic pen 50 calculated by the coordinate calculation unit 57 Each of the signals representing the coordinates (x, y) is encoded, converted into a wireless signal, and wirelessly transmitted to the receiving unit 42 of the drawing apparatus 40.

  Next, the drawing device 40 will be described.

  The drawing device 40 creates a drawing signal based on the position coordinates (x, y) calculated by the coordinate calculation unit 57 of the electronic pen 50 and the drawing mode S0, and outputs the drawing signal to the image display device 30. This drawing signal is a signal for displaying on the panel 10 an image handwritten by the user or a cursor used as a pointer, and is substantially the same as the image signal.

  As shown in FIG. 1, the drawing apparatus 40 includes a receiving unit 42 and a drawing unit 46.

  The receiving unit 42 includes a conversion circuit that receives a wireless signal wirelessly transmitted from the transmitting unit 58 of the electronic pen 50, decodes the received signal, and converts it into an electrical signal (not shown in FIG. 1). Then, the wireless signal wirelessly transmitted from the transmitter 58 is converted into the identification number (ID) of the electronic pen 50, the drawing mode S0, the states S1, S1 ′, S2, the determination result S3, the reset signal, and the position coordinates (x, y). Is output to the drawing unit 46. When there are a plurality of electronic pens 50, each signal transmitted from each electronic pen 50 is received and decoded.

  Note that signals representing the drawing mode S0, the states S1, S1 ′, S2, the determination result S3, and the position coordinates (x, y) of the electronic pen 50 are variables that change with time t. Each of the signals is represented by drawing mode S0 (t), state S1 (t), state S1 ′ (t), state S2 (t), determination result S3 (t), position coordinates (x (t), y (t )).

  The drawing unit 46 includes an image memory 47. Then, the drawing unit 46 draws a color and size corresponding to the drawing mode S0 (t) with the pixel corresponding to the position coordinates (x (t), y (t)) calculated by the coordinate calculation unit 57 as the center. A drawing signal of a pattern (for example, a pattern such as a white circle) is created and written into the image memory 47.

  The drawing unit 46 is in a state S1 (t) = 1 (a state where the contact switch 53 is on), or a state S2 (t) = 1 and a state S1 ′ (t) = 1 (the attachment 80 is attached to the electronic pen 50, When the drawing manual switch 83 is on), the created drawing signal is stored in the image memory 47. Therefore, during the period in which these states are maintained, a drawing signal obtained by adding the current position coordinates of the electronic pen 50 to the past position coordinates of the electronic pen 50 is accumulated in the image memory 47.

  Further, the drawing unit 46 is in a state S1 (t) = 0 (a state where the contact switch 53 is off), or a state S2 (t) = 1 and a state S1 ′ (t) = 0 (the attachment 80 is attached to the electronic pen 50) When the drawing manual switch 83 is off), the drawing signal corresponding to the position coordinate (x (t-1), y (t-1)) one field before is erased from the image memory 47. . Therefore, the drawing signal stored in the image memory 47 during the period in which these states are maintained is the drawing signal when the contact switch 53 is on or the attachment 80 is attached to the electronic pen 50 and the drawing signal is used. This is a signal (pointer function) representing the past locus of the position coordinates of the electronic pen 50 and the current position coordinates of the electronic pen 50 when the manual switch 83 is on.

  In addition, the drawing unit 46 is in a state S1 (t) = 0 and a state S2 (t) = 0 (the contact switch 53 is in an off state and the attachment 80 is not attached to the electronic pen 50), and for drawing erasure. When the switch (not shown) is on, the drawing signal stored in the image memory 47 is based on the position coordinates (x (t), y (t)) calculated from the light reception signal of the light receiving element 54. Erase from the image memory 47 (erase function).

  If there are a plurality of electronic pens 50 used in the image display system 100, the drawing unit 46 determines the position coordinates (x (t), y (t)) so that the trajectories of the electronic pens 50 are not confused with each other. Are distinguished from each other, and the above-described operation is performed on each electronic pen 50.

  Then, the drawing unit 46 outputs the drawing signal accumulated in the image memory 47 to the image display device 30.

  Next, the electronic pen 50 and the attachment 80 will be described with reference to FIG.

  FIG. 8 is a perspective view showing the external appearance of the electronic pen 50 and the electronic pen attachment 80 according to Embodiment 1 of the present invention.

  As shown in FIG. 8, the electronic pen 50 includes a cylindrical main body case 60, a proximity pen tip cover 61, a remote pen tip cover 62, a proximity pen tip portion 64, and a remote pen tip portion 65.

  As shown in FIG. 8, the remote pen tip cover 62 is provided with a rim 63 for fixing the attachment 80.

  The attachment 80 has a cylindrical shape, and has a condensing lens 84 at one end, and a flange that fits the rim 63 is provided in the other end. Then, by attaching the attachment 80 to the electronic pen 50 so that the flange and the rim 63 are fitted, the attachment 80 is fixed to the end of the electronic pen 50 on the remote side.

  When the attachment 80 is attached to the electronic pen 50, the length of the main body of the attachment 80 and the installation position of the condenser lens 84 so that the light receiving element 54 is located at the focal length on the optical axis of the condenser lens 84. , And the focal length of the condenser lens 84 is set.

  Then, by directing the remote end (remote optical axis) of the electronic pen 50 attached with the attachment 80 toward the panel 10, the light emitted from the panel 10 is emitted from the condenser lens 84 and the light receiving hole 68 of the attachment 80. And reaches the light receiving element 54.

  Although not shown in FIG. 8, the electronic pen 50 is turned on when the attachment 80 is attached to the electronic pen 50 and outputs S2 = “1”, and the attachment 80 is attached to the electronic pen 50. If not, an attachment detection switch that turns off and outputs S2 = "0" is provided.

  As shown in FIG. 8, the main body case 60 is provided with a power switch 81, a pilot lamp 82 provided integrally with the power switch 81, and a plurality of push-type manual switches 83 on the upper surface side of the main body case 60. . Further, a push-in type attachment detection switch and a rolling prevention rib are provided in the vicinity of the remote side end on the back side of the main body case 60.

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

  FIG. 9 is a diagram schematically showing an example of an operation when the electronic pen 50 is used in proximity in the image display system 100 according to Embodiment 1 of the present invention.

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

  As shown in FIG. 9, 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 line) to the lower end (n-th line) 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 near end of the electronic pen 50 is in contact (or close) with the “coordinate (x, y)” of the image display surface of the panel 10, the first light emitting line Ly <b> 1 has the coordinate (x, y). The light receiving element 52 receives light emission at the time tyy1 that passes through and the time txx1 when the second light emitting line Lx1 passes through the coordinates (x, y).

  As a result, as shown in FIG. 6, the electronic pen 50 outputs a light reception signal indicating that the light receiving element 52 has received the light emitted from the first light emitting line Ly1, at time tyy1, and the light receiving element 52 is in the second state. A light reception signal indicating that the light emission of the light emission line Lx1 has been received is output at time txx1.

  As shown in FIG. 10, 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 optical axis of the attachment 80 attached to the remote side end of the electronic pen 50 is directed to the “coordinate (x, y)” of the image display surface of the panel 10, the third light emitting line Ly2 is the coordinate (x , Y), and at time txx2 when the fourth light emitting line Lx2 passes the coordinates (x, y), the light receiving element 54 receives light.

  As a result, as shown in FIG. 7, the electronic pen 50 outputs a light reception signal indicating that the light receiving element 54 has received light emitted from the third light emitting line Ly2, at time tyy2, and the light receiving element 54 is in the fourth state. A light reception signal indicating that the light emission of the light emission line Lx2 has been received is output at time txx2.

  Then, the coordinate calculation unit 57 calculates the position coordinates (x, y) of the electronic pen 50 in the image display area by the method described above.

  FIG. 11 is a diagram schematically showing an example of an operation when performing handwriting input with the electronic pen 50 in the image display system 100 according to Embodiment 1 of the present invention.

  FIG. 11 shows an example when the electronic pen 50 is used in the vicinity, but the operation when the electronic pen 50 is used remotely by attaching the attachment 80 is a manual switch 83 for drawing instead of the contact switch 53. Since it is the same as that in proximity use except that is used, the description with reference to the drawings is omitted.

  The drawing unit 46 draws a drawing pattern (with a color and size corresponding to the drawing mode S0 (t) around the pixel corresponding to the position coordinates (x (t), y (t)) calculated by the coordinate calculation unit 57. For example, a drawing signal of a pattern such as a white circle (hereinafter referred to as “cursor 101”) is generated. The drawing signals are sequentially written in the image memory 47 of the drawing unit 46, and the state S1 (t) = 1 (the contact switch 53 is on), or the state S2 (t) = 1 and the state S1 ′ (t) = The drawing signal during the period of 1 (the attachment 80 is attached to the electronic pen 50 and the drawing manual switch 83 is on) is stored in the image memory 47. 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. 11, when the user moves the proximal end of the electronic pen 50 in contact with the image display surface of the panel 10 (at the time of remote use, the manual switch 83 for drawing is turned on. If the position coordinate of the electronic pen 50 is moved while the electronic pen 50 is moved), 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.

  FIG. 12 is a diagram schematically showing an example of an operation when the electronic pen 50 is used as a pointer in the image display system 100 according to Embodiment 1 of the present invention.

  FIG. 12 shows an example when the electronic pen 50 is used remotely. The operation when using the electronic pen 50 in the vicinity is performed remotely except that the contact switch 53 is used instead of the manual switch 83 for drawing. Since it is the same as the time, description using drawings is omitted.

  In the present embodiment, the electronic pen 50 is attached unless the manual switch 83 for drawing is turned on when the attachment 80 is attached to the electronic pen 50 and used remotely (or the contact switch 53 is not turned on when used in proximity). Can be used as a pointer.

  The light receiving element 54 emits light from the panel 10 during the period of the state S2 (t) = 1 and the state S1 ′ (t) = 0 (the attachment 80 is attached to the electronic pen 50 and the drawing manual switch 83 is off). If the light receiving element 52 can receive light (or if the light receiving element 52 can receive the light emission of the panel 10 during the period of the state S1 (t) = 0 (the contact switch 53 is OFF)), the drawing unit 46 draws the current drawing of the electronic pen 50. Signals (position coordinates (x (t), y (t)) and drawing signals based on the drawing mode S0 (t)) are written into the image memory 47, and the drawing signal (position coordinates (x (t) -1) and y (t-1))) are deleted from the image memory 47.

  Therefore, for example, when the user moves the position coordinate of the electronic pen 50 while the drawing manual switch 83 is turned off during remote use (or moves without touching the near end on the panel 10 during close use) ) Is not displayed on the panel 10, and the cursor 101 indicating the current position coordinates of the electronic pen 50 is displayed on the panel 10.

  In this way, the electronic pen 50 can be used as a pointer.

  When the light receiving elements 52 and 54 of the electronic pen 50 cannot receive the light emission of the panel 10, the cursor 101 is not displayed on the panel 10, or when the light receiving element 52 or the light receiving element 54 last receives the light emission of the panel 10. For example, the cursor 101 may be displayed at the coordinate position.

  As described above, the electronic pen 50 according to the present embodiment uses the light emission of the proximity y coordinate detection pattern and the light emission of the proximity x coordinate detection pattern when the electronic pen 50 is used remotely. The distance from 50 to panel 10 can be determined.

  In the present embodiment, the distance detection signal is a signal that becomes Hi only during the y-coordinate detection period Py1, and only light emission by the proximity y-coordinate detection pattern is used to determine the distance from the electronic pen 50 to the panel 10. It is good also as a structure. Alternatively, the distance detection signal may be a signal that becomes Hi only during the x-coordinate detection period Px1, and only light emission by the proximity x-coordinate detection pattern may be used to determine the distance from the electronic pen 50 to the panel 10.

  In the present embodiment, the configuration in which the contact switch 53 is attached to the tip of the electronic pen 50 has been described. However, for example, a manual switch corresponding to the contact switch 53 is provided on the side surface of the electronic pen 50 and the like. Alternatively, the user may be able to perform drawing by turning on / off a manual switch.

  As another example of the operation performed by the image display system using the determination result S3 of the distance from the electronic pen 50 to the panel 10, for example, the state of the determination result S3 is turned on / off in the electronic pen 50, or There is a configuration in which a display unit (for example, an LED or the like) for displaying by the emission color or the like is provided and the state of the determination result S3 is displayed on the display unit.

  As still another example of the operation performed by the image display system using the determination result S3 of the distance from the electronic pen 50 to the panel 10, for example, the state of the determination result S3 is turned on / off on the image display device. Or the structure which displays the state of determination result S3 on the display part (for example, LED etc.) displayed by luminescent color etc. is mentioned. Or the structure which displays the state of determination result S3 with a character and a symbol in an image display area can also be mentioned.

  As described above, by displaying the determination result of the distance from the electronic pen 50 to the panel 10 on the electronic pen 50 or the image display device, the user of the electronic pen 50 knows the distance from the electronic pen 50 to the panel 10. be able to. Accordingly, the user can consciously adjust the distance from the electronic pen 50 to the panel 10 and can appropriately write to the image display device.

(Embodiment 2)
In the present embodiment, an example of an operation performed by the image display system using the determination result S3 of the distance from the electronic pen 50 to the panel 10 when the electronic pen 50 is used remotely will be described.

  When the electronic pen 50 is used remotely, the range (light receiving range) on the panel 10 in which the light receiving element 54 of the electronic pen 50 can receive light changes according to the distance from the electronic pen 50 to the panel 10.

  FIG. 13 is a diagram schematically illustrating an example of a light receiving range of the electronic pen 50 when the electronic pen 50 according to Embodiment 2 of the present invention is used remotely.

  FIG. 14 is a diagram schematically illustrating another example of the light receiving range of the electronic pen 50 when the electronic pen 50 according to Embodiment 2 of the present invention is used remotely.

  As shown in FIG. 13, the light receiving range of the electronic pen 50 becomes narrower as the distance from the electronic pen 50 to the panel 10 becomes shorter, and becomes wider as the distance becomes longer.

  On the other hand, as shown in FIG. 14, if the position coordinate of the electronic pen 50 is near the end of the panel 10, the light receiving range of the electronic pen 50 may protrude outside the image display area of the panel 10. In such a case, the amount of light received by the electronic pen 50 is lower than when the entire light receiving range is within the image display area of the panel 10. For this reason, the electronic pen 50 cannot sufficiently receive the light emission generated in the coordinate detection subfield, and the position coordinate detection operation may become unstable.

  Therefore, in the present embodiment, when the electronic pen 50 is used remotely, a “detection effective area” and a “non-detection area” are provided in the image display area of the panel 10, and the position coordinates detected in the “detection effective area” are provided. Is used for drawing, and position coordinates are not detected in the “non-detection area”, or position coordinates detected in the “non-detection area” are not used for drawing. In this way, by restricting the position coordinate detection range, the position coordinate detection operation is prevented from becoming unstable near the end of the panel 10.

  FIG. 15 is a diagram schematically showing a setting example of the detection effective area and the non-detection area on the panel 10 when the electronic pen 50 according to Embodiment 2 of the present invention is used remotely.

  FIG. 16 is a diagram schematically showing another setting example of the detection effective area and the non-detection area on the panel 10 when the electronic pen 50 according to the second embodiment of the present invention is used remotely.

  In FIG. 15 and FIG. 16, for convenience, the “detection effective area” is shown in black and the “non-detection area” is shown in gray. However, such a luminance difference does not occur in the actual panel 10.

  In the following description, the size of the image display area of the panel 10 in the x coordinate direction and the y coordinate direction is assumed to be 100%.

  In the present embodiment, when the distance from the electronic pen 50 to the panel 10 is relatively long (when the distance determination unit 91 outputs S3 = “0”), the distance from the electronic pen 50 to the panel 10. The detection effective area is reduced and the non-detection area is enlarged compared to when the distance is relatively close (when S3 = “1” is output from the distance determination unit 91).

  When the distance from the electronic pen 50 to the panel 10 is relatively short and S3 = "1" is output from the distance determination unit 91, for example, as shown in FIG. A peripheral area of 5% at each of the upper and lower ends with respect to the x coordinate direction is set as a non-detection area, and an area with 90% of the y coordinate direction and 90% of the x coordinate direction excluding the non-detection area is set as a detection effective area.

  When the distance from the electronic pen 50 to the panel 10 is relatively long and S3 = “0” is output from the distance determination unit 91, for example, as shown in FIG. , A peripheral area of 10% each of the upper and lower ends with respect to the x coordinate direction is set as a non-detection area, and an area of 80% y coordinate direction and 80% in the x coordinate direction excluding the non-detection area is set as a detection effective area.

  As described above, in the present embodiment, when the distance from the electronic pen 50 to the panel 10 is relatively short (S3 = “1”) and the light receiving range of the electronic pen 50 is relatively narrow, the non-detection region is set to a relatively narrow range. When the distance from the electronic pen 50 to the panel 10 is relatively long (S3 = “0”) and the light receiving range of the electronic pen 50 is relatively wide, the non-detection area is set to a relatively wide range. Thus, the light receiving range of the electronic pen 50 is prevented from protruding outside the image display area of the panel 10, and the position coordinate detection operation of the electronic pen 50 is prevented from becoming unstable.

  Note that if drawing is performed in accordance with the position coordinates of the electronic pen 50 in this state, drawing or cursor display can be performed at an arbitrary position within the detection effective area, but drawing or cursor is performed in the non-detection area of the panel 10. It cannot be displayed. Therefore, in this embodiment, it is assumed that the position coordinates are corrected according to the ratio between the detection effective area and the non-detection area, and drawing is performed based on the corrected position coordinates.

  Hereinafter, the position coordinates detected by the electronic pen 50 are referred to as “detected coordinates”, and the corrected position coordinates are referred to as “display coordinates”.

  FIG. 17 is a diagram schematically showing a relationship between detected coordinates and display coordinates in the second embodiment of the present invention.

  In FIG. 17, as an example, the peripheral areas 10% left and right with respect to the y coordinate direction and 10% upper and lower ends with respect to the x coordinate direction shown in FIG. An example of correction of position coordinates when an area of 80% in the y coordinate direction and 80% in the x coordinate direction is set as a detection effective area will be described.

  In the present embodiment, in order to facilitate the calculation of the display coordinates, the center of the image display area of panel 10 is set as the origin (0, 0) for convenience.

  In the example shown in FIG. 17, the distance from the origin (0,0) to the end (x2,0) or (−x2,0) of the non-detection region in the x coordinate direction, and the x coordinate direction from the origin (0,0). The ratio of the distance to the end (x1,0) or (-x1,0) of the effective detection area is 5: 4. Similarly, the distance from the origin (0, 0) to the end (0, y2) or (0, -y2) of the non-detection area in the y coordinate direction, and the effective detection area in the y coordinate direction from the origin (0, 0) The ratio of the distance to the end (0, y1) or (0, -y1) is 5: 4.

Therefore, in the example shown in FIG. 17, the display coordinates are calculated by correction that multiplies the distance from the origin to the detected coordinates by 5/4. Specifically, if the detected coordinates are (x, y),
Display coordinates (X, Y) = (5/4 × x, 5/4 × y)
And

  In this way, the detection coordinates are corrected according to the ratio of the distance from the origin (0, 0) to the end of the non-detection area and the distance from the origin (0, 0) to the end of the detection effective area. Use display coordinates. By doing so, the drawing and cursor display based on the position coordinates detected in the effective detection area are enlarged over the entire image display area of the panel 10, so that it is possible to perform drawing and cursor display with the electronic pen 50 in the non-detection area. Become.

Although not shown, in the example shown in FIG. 15, the ratio of the distance from the origin (0, 0) to the end of the non-detection area and the distance from the origin (0, 0) to the end of the detection effective area is Since the x coordinate direction and the y coordinate direction are both 10: 9, if the detected coordinates are (x, y), the display coordinates (X, Y) = (10/9 × x, 10/9 × y)
And

  FIG. 18 is a diagram schematically showing a configuration example of the image display system 110 according to the second embodiment of the present invention.

  An image display system 110 illustrated in FIG. 18 includes an image display device 30, a drawing device 140, and an electronic pen 50 as components, and performs wireless communication between the electronic pen 50 and the drawing device 140. Although one electronic pen 50 is shown in FIG. 18, the image display system 110 may include a plurality of electronic pens 50.

  Since the image display device 30 and the electronic pen 50 shown in FIG. 18 have the same configuration and operation as the image display device 30 and the electronic pen 50 described in the first embodiment, the description thereof is omitted.

  The drawing device 140 includes a receiving unit 42 and a drawing unit 146, and the drawing unit 146 includes an image memory 47 and a coordinate conversion unit 48.

  The drawing device 140 has the same configuration and operation as the drawing device 40 described in the first embodiment except that the drawing unit 146 includes the coordinate conversion unit 48. Hereinafter, the operation of the coordinate conversion unit 48 will be described. It will be described and other detailed description will be omitted.

  The coordinate converter 48 receives the state S2 of the attachment detection switch 86, the determination result S3, the detected coordinates (x, y), and the reset signal, and outputs the display coordinates (X, Y).

  The coordinate conversion unit 48 determines the distance from the origin (0, 0) to the end of the non-detection area and the detection effective area from the origin (0, 0) in each of the determination results S3 = “1” and “0”. The ratio of the distance to the end is stored in advance as a correction coefficient.

  For example, in the example shown in FIGS. 15 and 16, the correction coefficient when the determination result S3 = “1” is “10/9”, and the correction coefficient when the determination result S3 = “0” is “5/9”. 4 ".

  If the state S2 = 0, the coordinate conversion unit 48 determines that the attachment 80 is not attached to the electronic pen 50 and the electronic pen 50 is being used in proximity, and there is nothing in the detected coordinates (x, y). Without correction, the detected coordinates (x, y) are output as display coordinates (X, Y) as they are. If the state S2 = 1, it is determined that the attachment 80 is attached to the electronic pen 50 and the electronic pen 50 is used remotely, and the correction coefficient based on the determination result S3 is detected coordinates (x, y) as described above. ) To calculate the display coordinates (X, Y).

  The drawing unit 146 generates a drawing signal based on the display coordinates (X, Y) output from the coordinate conversion unit 48 and outputs the drawing signal to the image display device 30.

  In the coordinate converter 48, a limiter corresponding to the size of the image display area of the panel 10 is set. Accordingly, when correction is made to the detected coordinates included in the “non-detection area” range, the corrected value is limited by this limiter, so that the display coordinates do not become values outside the image display area of the panel 10. . Thus, in the present embodiment, the position coordinates detected in the “non-detection area” are not used for drawing. This can be paraphrased as “the drawing apparatus 140 can set the“ non-detection region ”by the correction coefficient”. That is, in the present embodiment, the “non-detection area” is changed by changing the correction coefficient based on the determination result S3 in the coordinate conversion unit 48.

  Alternatively, when the position coordinate calculated by the coordinate calculation unit 57 of the electronic pen 50 is included in the range of the “non-detection region”, the electronic control unit 57 outputs the position coordinate calculated last in the detection effective region from the coordinate calculation unit 57. The pen 50 may be configured. By doing so, it is also possible to prevent the position coordinates corresponding to the “non-detection region” from being transmitted from the electronic pen 50 to the drawing device 140.

  As described above, in the present embodiment, by setting the non-detection area according to the distance from the electronic pen 50 to the panel 10, the light receiving range of the electronic pen 50 protrudes outside the image display area of the panel 10. It is possible to prevent the position coordinate detection operation of the electronic pen 50 from becoming unstable.

  In order to avoid unintentional switching of the non-detection area while the user is using the electronic pen 50, for example, the non-detection area may be changed using a reset signal as a trigger.

  For example, the distance determination unit 91 may be configured so that the determination made first is maintained until a reset signal is input from the synchronization detection unit 56. For example, if the initial determination is S3 = “1”, then S3 = “1” until the reset signal is input from the synchronization detection unit 56 even if both the received light signals are less than the distance threshold Th2. ”. Alternatively, if the initial determination is S3 = “0”, then S3 = “0” until the reset signal is input from the synchronization detection unit 56 even if the received light signal becomes equal to or greater than the distance threshold Th2. To maintain. The distance determination unit 91 may be configured to perform such an operation. The “determination to be performed first” is a determination immediately after the reset is released or immediately after the electronic pen 50 is turned on.

  Alternatively, the coordinate conversion unit 48 may be configured such that the initially set correction coefficient is maintained until a reset signal is input. For example, if the first correction coefficient is S3 = “1”, even if S3 = “0” thereafter, the correction coefficient of S3 = “1” is maintained until a reset signal is input. To do. Alternatively, if the first correction coefficient is the correction coefficient of S3 = “0”, the correction coefficient of S3 = “0” is maintained until the reset signal is input even if the S3 = “1” is changed thereafter. To do. The coordinate conversion unit 48 may be configured to perform such an operation. The “first correction coefficient” is a correction coefficient that is set immediately after the reset signal is released or immediately after the electronic pen 50 is turned on.

  By configuring the distance determination unit 91 or the coordinate conversion unit 48 in this way, it is possible to prevent the undetected region from being unintentionally switched while the user is using the electronic pen 50.

  However, the coordinate conversion unit 48 in the present embodiment is not limited to the above-described operation, and may be configured to appropriately change the correction coefficient according to the determination result S3, for example.

  In the present embodiment, the synchronization detection unit 56 generates a reset signal if it does not detect the light emission for synchronization detection generated in the synchronization detection period Po for a predetermined time (for example, 0.25 seconds) or more. The reset signal may be generated by a manual switch.

  In the present embodiment, the order of occurrence of each coordinate detection subfield is not limited to the order of occurrence described above. For example, the proximity coordinate detection subfield may be generated after the remote coordinate detection subfield, or the x coordinate detection subfield is generated first, and then the y coordinate detection subfield is generated. May be.

  Note that although an example in which wireless communication is performed between the drawing apparatus and the electronic pen has been described in this embodiment, the present invention is not limited to this configuration. For example, the drawing device and the electronic pen may be electrically connected by an electric cable or the like, and a signal may be transmitted and received between the electronic pen and the drawing device via the electric cable.

  In the present embodiment, a configuration in which the drawing device is provided independently of the image display device has been described. As an example of this configuration, for example, a computer connected to the image display device has a function corresponding to the drawing device. The 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 embodiment of the present invention 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. You may comprise using the microcomputer etc. which were programmed to operate | move.

  The specific numerical values shown in the embodiments of the present invention are merely examples of the embodiments, and the present invention is not limited to these numerical values. It is desirable to set each numerical value optimally according to the specifications of the electronic pen charging system.

  The present disclosure is useful as an image display system including an electronic pen and an electronic pen that can improve usability in an electronic pen that can be input to an image display device from a position away from an image display surface.

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 Circuit 32 Data electrode drive circuit 33 Scan electrode drive circuit 34 Sustain electrode drive circuit 35 Timing generation circuit 40,140 Drawing device 42 Reception unit 46,146 Drawing unit 47 Image memory 48 Coordinate conversion unit 50 Electronic pen 52, 54 Light receiving element 53 Contact Switch 56 Synchronization detector 57 Coordinate calculator 58 Transmitter 60 Body case 61 Proximity pen tip cover 62 Remote pen tip cover 63 Rim 64 Proximity pen tip 65 Remote pen tip 68 Light receiving hole 80 Electronic pen attachment 81 Power switch 82 Pilot lamp 8 3 Manual switch 84 Condensing lens 86 Attachment detection switch 91 Distance determination unit 100, 110 Image display system 101 Cursor Ly1 First light emission line Lx1 Second light emission line Ly2 Third light emission line Lx2 Fourth light emission line SF1 to SF8 Image display subfield SFo Synchronization detection subfield SFy1 Proximity y coordinate detection subfield SFx1 Proximity x coordinate detection subfield SFy2 Remote y coordinate detection subfield SFx2 Remote x coordinate detection subfield

Claims (13)

A light receiving element that generates a light receiving signal having a magnitude corresponding to the amount of light received;
A synchronization detection unit that generates a coordinate reference signal based on a light reception signal output from the light receiving element;
A coordinate calculation unit for calculating position coordinates based on the light reception signal and the coordinate reference signal;
A distance determination unit that determines a distance to the image display device based on the light reception signal;
With
The received light signal used in the synchronization detecting unit, the received light signal used for calculating the position coordinate in the coordinate calculating unit, and the received light signal used for determining the distance in the distance determining unit are different from each other. Electronic pen to do. The synchronization detector
While generating a distance detection signal that permits the distance determination unit to accept the light reception signal,
The electronic pen according to claim 1, wherein the coordinate reference signal and the distance detection signal are generated at different timings. 3. The electronic pen according to claim 2, wherein the distance determination unit determines the distance by comparing a received light signal received based on the distance detection signal with a preset distance threshold value. Attaching a detachable attachment having a condenser lens for receiving light emitted from the image display device at a position away from the image display device,
The electronic pen according to claim 1, wherein the distance determination unit operates only when the attachment is attached. The electronic pen according to claim 1, wherein the determination result output from the distance determination unit is maintained until reset. The synchronization detection unit is configured to detect light emission of a predetermined pattern,
The electronic pen according to claim 5, wherein the synchronization detection unit generates the reset when light emission of a predetermined pattern cannot be detected for a predetermined time. An image display device for generating a synchronization detection subfield, a proximity y coordinate detection subfield, a proximity x coordinate detection subfield, a remote y coordinate detection subfield, and a remote x coordinate detection subfield;
An electronic pen having a light receiving element that generates a light reception signal having a magnitude corresponding to the amount of light received;
An image display system that performs drawing at a position based on the position coordinates of the electronic pen in the image display area of the image display device,
The electronic pen is
Light emission generated in the image display device in the proximity y coordinate detection subfield and the proximity x coordinate detection subfield, or the image display in the remote y coordinate detection subfield and the remote x coordinate detection subfield A coordinate calculation unit for calculating position coordinates based on any of the light emission generated in the apparatus;
A distance determination unit that determines a distance from the electronic pen to the image display device based on light emission generated in the image display device;
The distance determination unit
When the coordinate calculation unit calculates the position coordinates based on light emission of the remote y coordinate detection subfield and the remote x coordinate detection subfield,
An image display system for determining a distance from the electronic pen to the image display device based on light emission of at least one of the proximity y coordinate detection subfield and the proximity x coordinate detection subfield. The synchronization detector
Based on light emission generated in the image display device in the synchronization detection subfield, a coordinate reference signal serving as a reference when calculating position coordinates, and a distance detection signal that permits the distance determination unit to accept the received light signal. The image display system according to claim 7, wherein the coordinate reference signal and the distance detection signal are generated at different timings. 9. The image display system according to claim 8, wherein the distance determination unit determines the distance by comparing the received light signal received based on the distance detection signal with a preset distance threshold value. . Attaching a detachable attachment having a condenser lens for receiving the emitted light at a position away from the image display device,
The image display system according to claim 7 or 9, wherein the distance determination unit operates only when the attachment is attached. In the image display area, a detection effective area and a non-detection area are provided,
In the detection effective area, the detected position coordinates are used for drawing in the image display device,
In the non-detection area, the position coordinates are not detected, or the detected position coordinates are not used for the drawing,
The image display system according to claim 7 or 9, wherein the size of the non-detection region is changed based on a determination result in the distance determination unit. The image display system according to claim 11, wherein the size of the non-detection area is maintained until reset. The image display system according to claim 12, wherein the synchronization detection unit generates the reset when light emission of the synchronization detection subfield cannot be detected for a predetermined time.