JPH1026957A - Method for driving gas discharge display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress pseudo outline disturbance in a moving image due to sub-field division and to obtain a high quality video by changing a whole period once or more in one field in sub-field when a cathode is scanned at high speed with continuous write-in. SOLUTION: A cathode drive part is divided to plural drive parts. In the case of being divided into two systems, the part is divided to an odd row cathode drive part 2a for driving an odd row cathode group 5a and an even row cathode drive part 2b for driving an even row cathode group 5b. Then, the number of scan pulses applied to the cathode in the period subtracting an upkeep pulse width from an upkeep pulse period are decided to a fixed number beforehand at every sub-field, and all pulse periods applied to the cathode and an anode are revised at least once or more in one field in sub-field. Further, the start points of the scan pulses started at every sub-field are made start from plural ends of plural cathode groups to be scanned respectively successively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a matrix type display device and, more particularly, to a method of driving a gas discharge display panel for displaying images by using a pulse memory driving method.

[0002]

2. Description of the Related Art A conventional general gas discharge display panel includes:
Electrodes and barriers are formed by thick-film printing on two glass plates on the front and back sides, and a mixed gas such as He (helium) or Xe (xenon) is placed in spaces (display cells and auxiliary cells) separated by the barriers. Enclosed. Then, a discharge is caused between the display anode and the cathode in the display cell, and the phosphors are excited by the ultraviolet light generated at this time, thereby obtaining light emission of three primary colors. For this, various documents (for example, Broadcasting Technology, November 1993)
Monthly publications such as "Plasma Display Aiming at Large HDTV Wall-Mounted TV"), a detailed description is omitted here.

FIG. 12 shows a DC type gas discharge display device D.
It is a block diagram which shows the drive circuit part of C type gas discharge display panels. In FIG. 12, the DC-type gas discharge display device includes a gas discharge display panel 1, a cathode drive unit 2, a display anode drive unit 3, and an auxiliary anode drive unit 4. The scanning / sustaining control information is input to the cathode driving unit 2 to drive the cathodes 5 (CA1 to CA8) of the gas discharge display panel 1. The write control information is input to the display anode drive unit 3 to drive the display anodes 6 (DA1 to DA6) of the gas discharge display panel 1. In addition, auxiliary discharge control information is input to the auxiliary anode drive unit 4, and the auxiliary anode 7 (AA1 to AA1) of the gas discharge display panel 1 is input.
AA3) is driven. Here, for simplicity, the gas discharge display panel 1 has eight cathodes CA1 to CA8, six display anodes DA1 to DA6 and six auxiliary anodes AA1.
, To AA3.

[0004] The display cell 8 is where the cathode 5 and the display anode 6 of the gas discharge display panel 1 intersect.
The intersection of the cathode 5 and the auxiliary anode 7 is the auxiliary cell 9. A pulse having the same phase is applied to each of the cathode 5 and the auxiliary anode 7, and each of the auxiliary cells 9 is sequentially discharged in the row direction. The display cell 8 is written and discharged. Then, the cathode 5 is provided only for a period required for display.
A sustain pulse having a phase different from that of the write pulse is applied to sustain the discharge, and each display cell 8 is discharged to obtain a required light emission luminance. As described above, the gas discharge display panel 1 itself does not have a memory function, but a driving method in which the driving circuit has a memory function is called a pulse memory driving method.

FIG. 13 is a waveform chart showing an example of driving waveforms for explaining the operation of the gas discharge display device shown in FIG. FIG. 13 shows display anodes 6 of DA1 to DA6 and C6.
The drive waveforms of the cathodes A1 to CA8 (here, only CA1 to CA3 are shown) and the auxiliary anodes 7 of AA1 to AA3 (collectively AA) are shown. CA1 to CA8 of cathode 5
Are applied with a scan pulse and a sustain pulse. The sustain pulse is the number of pulses for maintaining the number of discharges corresponding to the desired light emission luminance. Here, for the sake of simplicity, a part of a scanning pulse and a sustain pulse following the scanning pulse are shown. DA1 to DA6 of display anode 6 intersecting CA1 to CA8 of cathode 5
Takes a low (L) or high (H) value based on the display data at the same phase as the scanning pulse applied to CA1 to CA8 of the cathode 5.

When a scanning pulse is input to the cathode 5 and the display anode 6 is at H (write pulse), a voltage necessary for starting discharge is applied to the cathode 5 and the display anode 6 to start discharging. Once the discharge starts, the discharge is maintained by a sustain pulse having a different pulse phase and the same pulse period from the scan pulse. The voltage applied between the cathode 5 and the display anode 6 by the sustain pulse is a voltage that does not start the discharge by itself, and is set to a voltage that can sustain the discharge written by the scan pulse and the write pulse. Scan pulse to the cathode 5, the writing pulse to the sustain pulse and the display anode 6, phase, pulse width different from each other, but the period is constant, here, the T _H. Writing for each line is performed for the display cell 8 at a period of T _H by the scanning pulse. Therefore, the time required for writing becomes T _H the period per line, time is 8T _H required for the eight cathode.

FIG. 14 is a diagram showing an example of the operation in the case of displaying a halftone by subfield division. Here, the number of cathodes is extended to N lines, and the operation is modeled and illustrated. FIG. 14 shows an example of 8 subfields to obtain 256 gradations (8 bits).
Each subfield is composed of writing by a scan pulse and the number of sustain pulses corresponding to binary weighting. FIG. 14 is drawn so that eight bits are sequentially displayed from the MSB (most significant bit) side of the binary value of the signal data.

[0008] As described above, the scanning pulse takes a time of 1 cathode per T _H, takes time for N × T _H The N line. Accordingly, the N-th cathode CA1
The Nth cathode CAN is after N × _TH time, and the envelope of the writing operation by the scanning pulse is as shown in FIG. The number of sustain pulses proportional to the bit weight is basically 128, 64, 32,..., 1 from the MSB, and is n times larger (n is a positive integer) in order to obtain emission luminance. ) The number of pulses is struck.

[0009]

[SUMMARY OF THE INVENTION In the conventional DC type gas-discharge display device described above, N × T _H × 8 needs to fall within the period of one field (16.6 ms). The scanning cycle T _H has a limit depending on the discharge characteristics and the driving capability of the circuit. The pilot discharge by DC scheme auxiliary cell, has the advantage that it is capable of high-speed control, the current T _H is a cathode number (number of lines) N is 512 approximately at 4 .mu.s. The gradation expression using an 8-bit digital signal required for image expression takes one field period as shown in FIG. The display method of the subfield does not particularly cause a serious problem in the case of a still image, but in the case of a moving image, the image is distorted, and a problem that a pseudo contour appears visually occurs.

The present invention has been made in view of such a problem. When the cathode is scanned at high speed by continuous writing, the entire period is changed at least once in one field in subfield units, and the An object of the present invention is to provide a method of driving a gas discharge display panel capable of suppressing a false contour disturbance in a moving image due to field division and obtaining a high-quality image.

[0011]

In order to achieve the above object, a method of driving a gas discharge display panel according to the present invention is a method of driving a gas discharge display panel in which a plurality of cathodes and anodes are arranged orthogonally to form a plurality of discharge cells in a matrix. A discharge pulse is applied to the discharge cells by sequentially applying a scan pulse to the cathode of the discharge display panel and applying a write pulse corresponding to the display data to the anode, and a subfield obtained by dividing one field into a plurality of fields is applied to the cathode. A method of driving a gas discharge display panel in which a sustaining pulse is applied by the number of times corresponding to the number of discharges corresponding to a desired light emission luminance to sustain the discharge to obtain a necessary light emission luminance for each discharge cell, The number of scanning pulses applied to the cathode during a period obtained by subtracting the sustain pulse width from the sustain pulse period is fixed in advance for each subfield. Defined number, is characterized in that to change at least once in one field period all the pulses applied to the cathode and the anode in each subfield.

In addition, a plurality of scanning pulses are continuously applied to the cathode, and a write pulse corresponding to the scanning pulse is applied to the anode in synchronization with the application of the scanning pulses. When continuously writing data, a plurality of scan pulses applied continuously within the sustain pulse period are assigned to a plurality of cathode groups obtained by dividing the cathode, and the starting point of the scan pulse started for each subfield is set to the start point. It is characterized in that scanning is performed in order starting from a plurality of ends of a plurality of cathode groups.

Further, the starting point of the scanning pulse in each of the plurality of cathode groups is changed at least once in one field in subfield units.

Further, when display data corresponding to a plurality of rows of cathodes are continuously written from the plurality of cathode groups within the sustain pulse period, the order of bits to be written in a subfield for each of the cathode groups is set to 1 It is characterized in that at least one or more different combinations are displayed in a field.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for driving a DC type gas discharge display panel according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing a driving circuit of a DC type gas discharge display panel according to the present invention. In FIG. 1, the same parts as those in the conventional example shown in FIG. The drive circuit of the DC type gas discharge display panel of this embodiment is different from the conventional example shown in FIG. 10 in that the cathode drive unit 2 is divided into a plurality of drive units, and the other blocks have the same configuration. . Here, in order to facilitate the explanation, the two systems are divided into an odd-numbered cathode drive unit 2a for driving the odd-numbered cathode group 5a and an even-numbered cathode drive unit 2b for driving the even-numbered cathode group 5b.

That is, the driving circuit of the DC-type gas discharge display panel of this embodiment shown in FIG. 1 includes a gas discharge display panel 1, an odd-numbered cathode drive unit 2a, an even-numbered cathode drive unit 2b, a display anode drive unit 3, An auxiliary anode drive unit 4 is provided. Scanning / sustaining control information is input to the odd-row cathode driving unit 2a, and the odd-row cathode group 5a of the gas discharge display panel 1 is input.
(CA1, CA3, CA5, CA7) are driven. Scanning / maintenance control information is also input to the even-numbered cathode drive unit 2b,
Even-numbered row cathode group 5b (CA2, C
A4, CA6, CA8). Display anode drive unit 3
Is supplied with write control information, and drives the display anodes 6 (DA1 to DA6) of the gas discharge display panel 1. Also,
The auxiliary-discharge control information is input to the auxiliary-anode driving unit 4 to drive the auxiliary anodes 7 (AA1 to AA3) of the gas discharge display panel 1. Here, for simplicity, the gas discharge display panel 1 is illustrated with eight cathodes of CA1 to CA8, six display anodes of DA1 to DA6, and three auxiliary anodes of AA1 to AA3. ing.

Cathode group 5 in gas discharge display panel 1
The display cell 8 is where the a and 5b cross the display anode 6, and the auxiliary cell 9 where the cathode groups 5a and 5b cross the auxiliary anode 7. A pulse having the same phase is applied to each of the cathode groups 5a and 5b and the auxiliary anode 7, and each auxiliary cell 9 is sequentially discharged in the row direction. Along with this discharge, a write pulse having the same phase is selectively applied to the display anode 6. Then, each display cell 8 is written and discharged. Then, a sustain pulse having a phase different from that of the write pulse is applied to the cathode groups 5a and 5b for a period required for display to sustain the discharge, and the respective display cells 8 are discharged to obtain a required emission luminance. Thus, the gas discharge display panel 1
A driving method that does not have a memory function but has a memory function by a driving circuit is called a pulse memory driving method.

[First Embodiment] A first embodiment of a driving method in a driving circuit of a DC-type gas discharge display panel according to the present invention configured as described above will be described with reference to FIG. FIG. 2 shows DA1 to DA1 as examples of driving waveforms when the gas discharge display panel having the configuration shown in FIG.
A display anode 6 of DA6 and a cathode group 5 of CA1 to CA8
a, 5b (here, only CA1 to CA4 are shown), AA
1 shows driving waveforms of the auxiliary anode 7 which are 1 to AA3 (collectively, AA).

A scan pulse and a sustain pulse are applied to CA1 to CA8 of the cathode groups 5a and 5b. The sustain pulse is the number of pulses for maintaining the number of discharges corresponding to the desired light emission luminance. Here, for the sake of simplicity, a part of a scanning pulse and a sustain pulse following the scanning pulse are shown. Cathode group 5a, 5
DA1 of the display anode 6 that intersects CA1 to CA8 of b
DA6 takes a value of either low (L) or high (H) based on display data at the same phase as the scanning pulse.

When a scanning pulse is inputted to any one of the cathodes CA1 to CA8 and the display anode 6 is at H (write pulse), the voltage required for starting discharge is a negative voltage.
The discharge starts because the voltage is applied between the display anodes. Once the discharge starts, the discharge is maintained by a sustain pulse having a different pulse phase and the same pulse period from the scan pulse. The sustain pulse voltage is a voltage that does not start the discharge by itself, and is set to a voltage that can sustain the discharge written by the scan pulse and the write pulse.

In the present invention, the period of the sustain pulse is T _H as in the prior art. The scanning pulse period, the scanning pulse period between an odd row group of cathodes 5a is T _H, likewise, the scan pulse period between an even row group of cathodes 5b are also T _H. The writing operation is performed when a scanning pulse is applied to one of the cathodes in the odd-numbered row cathode group 5a and a corresponding writing pulse is applied to DA1 to DA6 of the display anode 6, and When a scan pulse is applied to one cathode of the cathode group 5b, a corresponding write pulse is applied to DA1 to DA6 of the display anode 6 to write data.

In the present invention, the cathodes are divided into a plurality of cathode groups such as an odd-numbered cathode group 5a and an even-numbered cathode group 5b, and the writing by the scanning pulse applied to each cathode is performed by the odd-numbered cathode driving unit 2a. From one of the odd row cathodes
A scanning pulse is applied to the book, a writing discharge starts, and a scanning pulse is applied to one of the even-numbered cathodes from the even-numbered cathode driving unit 2b until a sustaining pulse for maintaining the discharge is input. Immediately after the scanning pulse is applied to one of them, the scanning pulse is continuously applied, and the odd-numbered cathode and the even-numbered cathode are continuously written within the sustain pulse period. That is, in a period in which the sustain pulse width is subtracted from the sustain pulse period, a scan pulse is assigned to each of the plurality of cathode groups with a different phase and continuously applied, and the write corresponding to the scan pulse is applied to the anode in synchronization with the scan pulse. By applying a pulse, display data corresponding to a plurality of rows of cathodes is continuously written within the sustain pulse period.

[0023] In the example of FIG. 2, can be written simultaneously cathode two lines of the odd rows adjacent to each other cathode and the even rows cathode within the period of T _H, the cathode 8 lines in half the period of the conventional example shown in FIG. 12 Can be scanned. Therefore, the slope of the envelope of the scanning pulse is doubled as in the conventional example shown in FIG. 13 in which the number of driving cathodes is reduced to half. Pulses applied to the auxiliary anode 7, the scanning pulse period of the scanning period T _H, since added 2 times in the first embodiment as depicted in FIG. 2, the auxiliary anode in accordance with the scan pulse phase A pulse is applied to perform an auxiliary discharge.

FIGS. 3 to 5 show examples of driving waveforms when the gas discharge display panel 1 having the structure shown in FIG. 1 is driven by continuous writing in two rows. FIG. 3 shows a subfield of the first embodiment. Drive waveforms in SF1 and SF2, FIG.
Is a driving waveform in the subfields SF3 and SF4 of the first embodiment, and FIG. 5 is a subfield SF5 of the first embodiment.
7 shows the driving waveforms in SF8.

[0025] In this first embodiment, the scanning pulse period and the sustain pulse cycle in the subfield SF1 and SF2 to write bit8 and bit7, subfield SF3 to the 2T _H as shown in FIG. 3, writes bit6 and bit5 When in SF4, a T _H as shown in FIG. 4, in the to subfields SF5 writing to no bit4 bit1 SF8, as referred to T _H / 2 as shown in FIG. 5, and continuously in the sustain pulse cycle With the number of lines to be written constant (in this first embodiment, 2
Row), only the entire period is changed in sub-field units. That is, the number of scan pulses applied to the cathode in a period obtained by subtracting the width of the sustain pulse from the cycle of the sustain pulse is previously set to a constant number for each subfield, and the cycle of the scan pulse and the sustain pulse applied to the cathode and the anode is determined. Subfields are changed three times in one field.
In this case, the entire cycle may be an integral multiple of T _H ,
Other periods may be used as long as the effects of the present invention are not impaired. FIG. 6 shows a halftone display method by subfield division according to the present invention when the cathode is an N line. FIG.
As can be seen from the above, in the first embodiment, the period required to finish eight subfields can be completed in about (1/2) field, and the remaining period is assigned to the sustain pulse to increase the number of sustain pulses. It is possible to further increase the luminance.

As described above, according to the first embodiment, the number of scanning pulses to be applied during a period obtained by subtracting the sustain pulse width from the sustain pulse period is determined in advance for each subfield, and the number of scan pulses By changing the period of the scanning pulse and the sustaining pulse applied to the anode at least once in one field in subfield units, it is possible to complete all subfields in less than half of the conventional case. Thus, it is possible to provide a high-quality image in which pseudo contour interference in a moving image caused by subfield division is suppressed.

[Second Embodiment] FIGS. 7 to 9 show examples of driving waveforms when the gas discharge display panel 1 having the structure shown in FIG. 1 is driven by continuous writing in two rows. FIG. 8 shows driving waveforms in subfields SF1 and SF2 of the second embodiment, FIG. 8 shows driving waveforms in subfields SF3 and SF4 of the second embodiment, and FIG. 9 shows driving waveforms in subfields SF5 to SF8 of the second embodiment. I have. Also in the second embodiment, as in the first embodiment, the number of rows to be continuously written within the sustain pulse cycle is fixed (two rows in the second embodiment), and only the entire cycle is set in subfield units. Has changed.

Therefore, the scan pulse period and the sustain pulse period are 2T in the subfields SF1 and SF2 in which bit8 and bit7 are written, as shown in FIG.
To _H, in the subfield SF3 and SF4 to write bit6 and bit5, the T _H as shown in FIG. 8,
Subfield SF for writing bit4 to bit1
5 In to SF8, T _H / 2 as shown in FIG. 9
It is. In this case, the entire cycle may be set to an integral multiple of T _H , or another cycle as long as the effect of the present invention is not impaired.

The difference between the second embodiment and the first embodiment is that in the first embodiment, bits 8 to
While the start point of the scanning pulse is up to the first row of the uppermost end of the cathode up to 1, in the second embodiment, the display data (pixels) corresponding to the two rows of cathodes of even and odd rows within the sustain pulse period. This is the point where the start point of the scanning pulse is a plurality of ends on the even-numbered row side when writing the signal continuously. As shown in FIG. 10, which shows a halftone display method by subfield division of the second embodiment when the cathode is an N line, as shown in FIG.
8 and bit7 are written in subfields SF1 and SF
7, in the sustain pulse period, two adjacent lines of the odd-numbered cathode and the even-numbered cathode are sequentially written sequentially from the first row at the uppermost end of the cathode within the sustain pulse period.

In subfields SF3 and SF4 in which bit6 and bit5 are written, as shown in FIG. 8, the first writing is performed on the first row (CA1) at the uppermost end of the cathode.
And the lowest row (CAN) at the lowermost end of the cathode (N is an even number; N = 8 in FIG. 8) is continuously scanned and written within the sustain pulse period. In the next write, CA3 and CA are written. (N
Scanning is performed every other row from the uppermost end of the odd-numbered cathodes and from the lowermost end of the even-numbered cathodes, such as by continuously scanning and writing the data in -2). Furthermore, from bit4 to bit1
In the subfields SF5 to SF8 for writing the first, as shown in FIG. 9, the first writing is performed on the first row (CA1) at the uppermost end of the cathode and the lowest row (CA1) at the lowermost end of the cathode.
N) (where N is an even number, N = 8 in FIG. 9) is continuously scanned and written in the sustain pulse period, and in the next write, CA3 and CA (N-2) are continuously scanned. As in the case of writing data, scanning is performed every other row from the odd-numbered cathode from the uppermost end and from the even-numbered cathode from the lowermost end. This second
In the embodiment, as in the first embodiment, as described above, the period required to finish eight subfields is about (1 /
2) It can be completed in the field, and the remaining period is assigned to the sustain pulse to increase the number of the sustain pulses, thereby further increasing the luminance.

As described above, according to the second embodiment, a plurality of scanning pulses are continuously applied to the cathode during a period obtained by subtracting the sustain pulse width from the period of the sustain pulse, and the scanning pulse is applied to the anode in synchronization with the period. When the display pulse corresponding to a plurality of rows is continuously written in the sustain pulse cycle by applying the write pulse corresponding to Allocated to a plurality of divided cathode groups, by starting the scanning pulse starting for each subfield from a plurality of ends of the plurality of cathode groups and sequentially scanning them, and in particular, a plurality of cathode groups Of the remote cathode by changing the starting point of the scanning pulse in each of the By performing continuous writing, the vertical direction is coarsely scanned. However, it can be considered that the vertical direction is visually averaged at an appropriate viewing distance from the gas discharge display panel, and scanning is performed twice in a subfield. When this is considered in the time direction, as shown in FIG. 10, scanning is performed more densely, and interference due to subfield division is visually reduced.

[Third Embodiment] FIG. 11 is a diagram showing a third embodiment of a halftone display method by subfield division according to the present invention, which is an application of the second embodiment shown in FIG. The third embodiment differs from the second embodiment in that, when display data (pixel signals) corresponding to a plurality of rows of cathodes are continuously written within a sustain pulse period, as shown in FIG. This means that the order of bits to be written in the field is changed and displayed. Generally, when a cathode is divided into a plurality of cathode groups and pixel signals corresponding to a plurality of rows of cathodes are continuously written within a sustain pulse period, the order of bits to be written in a subfield for each of the cathode groups is determined. And 1
It is easily conceivable that at least one different combination can be displayed in the field. As described above, in principle, by allocating a period in which the sustain pulse is omitted in the sustain pulse period to a plurality of continuous scan pulses, it is possible to write to a plurality of cathode lines. As described above, the order of the fields may be a plurality of combinations.

As described above, in the third embodiment, as in the second embodiment, the scanning of the distant cathodes is continuously performed, so that the vertical direction is roughly scanned. The visual distance is considered to be visually averaged in the vertical direction, which is equivalent to two scans performed in the subfield.
As shown in FIG. 1, the scanning is performed more densely, and the disturbance due to the subfield division is visually reduced. Also,
As in the third embodiment, by combining subfields of different bits for even-numbered cathodes and odd-numbered cathodes, pseudo contour interference in a moving image due to subfield division is suppressed, and higher image quality can be achieved. . In addition, since all sub-fields can be completed in 1/2 or less, the remaining period can be allocated to sustain pulses and the number of sustain pulses can be increased to further increase the luminance. Further, by scanning the cathode at a higher speed than before, it is possible to increase the number of driving cathode lines in the subfield period and the number of subfields in one field, thereby achieving improvement in image quality and higher brightness.

[0034]

As described above in detail, the method of driving a gas discharge display panel according to the present invention is directed to a gas discharge display panel in which a plurality of cathodes and anodes are arranged orthogonally to form a plurality of discharge cells in a matrix. By sequentially applying a scanning pulse to the negative electrode and applying a write pulse corresponding to the display data to the positive electrode, the discharge cell is started to discharge, and a desired field is set in the subfield obtained by dividing one field into a plurality of fields by the negative electrode. In the driving method of the gas discharge display panel, the sustaining discharge is applied by applying a number of sustain pulses corresponding to the number of discharges corresponding to the emission luminance to maintain the discharge and obtain the required emission luminance for each discharge cell. The number of scanning pulses applied to the cathode during a period obtained by subtracting the sustain pulse width from the pulse period is previously set to a constant number for each subfield. Since the period of all the pulses applied to the cathode and the anode is changed at least once in one field in sub-field units, all sub-fields are completed when the cathode is scanned at high speed by continuous writing. However, it is possible to reduce the number of sustain pulses by allocating the remaining period to a sustain pulse to increase the number of sustain pulses. It is possible to provide a high-quality image in which pseudo contour disturbance in an image is suppressed.

Further, by applying a plurality of scanning pulses to the cathode successively and applying a write pulse corresponding to the scanning pulse to the anode in synchronization with the scanning pulse, a plurality of rows of cathodes can be accommodated within the sustain pulse period. When continuously writing display data, a plurality of continuously applied scanning pulses within the sustain pulse period are assigned to a plurality of cathode groups obtained by dividing the cathode, and the starting point of the scanning pulse started for each subfield is determined. By starting from a plurality of ends of the plurality of cathode groups and sequentially scanning each,
It is possible to continuously write the scanning of the distant cathode, and the vertical direction is coarsely scanned, but it is considered that the vertical direction is visually averaged at a moderate viewing distance from the gas discharge display panel. This is equivalent to two scans performed in the field, and when considered in the time direction, the scan is performed more densely, and the interference due to the subfield division is visually reduced.

Further, the starting point of the scanning pulse in each of the plurality of cathode groups is changed at least once in one field in subfield units.
It is possible to perform continuous writing of the scanning of the distant cathode, and the vertical direction is coarsely scanned, but it is considered that the vertical direction is visually averaged at a moderate viewing distance from the gas discharge display panel, This is equivalent to two scans performed in the field, and when considered in the time direction, the scan is performed more densely, and the interference due to the subfield division is visually reduced.

Further, when display data corresponding to a plurality of rows of cathodes is continuously written from the plurality of cathode groups within the sustain pulse period, the order of bits to be written in a subfield for each of the cathode groups is set to 1 Since the display is made in at least one or more different combinations in the field, higher image quality can be achieved by combining subfields of different bits for the even cathode and the odd cathode. In addition, since all sub-fields can be completed in 1/2 or less, the remaining period can be allocated to sustain pulses and the number of sustain pulses can be increased to further increase the luminance. Further, by scanning the cathode at a higher speed than before, it is possible to increase the number of driving cathode lines in the subfield period and the number of subfields in one field, thereby achieving improvement in image quality and higher brightness.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a driving circuit of a gas discharge display panel of the present invention.

FIG. 2 is a waveform diagram illustrating an example of a driving waveform during two-row continuous writing driving.

FIG. 3 shows subfields SF1 and SF2 of the first embodiment.
FIG. 4 is a waveform chart showing an example of a drive waveform in FIG.

FIG. 4 shows subfields SF3 and SF4 of the first embodiment.
FIG. 4 is a waveform chart showing an example of a drive waveform in FIG.

FIG. 5 shows subfields SF5 to SF of the first embodiment.
FIG. 8 is a waveform chart showing an example of a drive waveform in FIG.

FIG. 6 is a diagram showing a first embodiment of a halftone display method by subfield division.

FIG. 7 shows subfields SF1 and SF2 of the second embodiment.
FIG. 4 is a waveform chart showing an example of a drive waveform in FIG.

FIG. 8 shows subfields SF3 and SF4 of the second embodiment.
FIG. 4 is a waveform chart showing an example of a drive waveform in FIG.

FIG. 9 shows subfields SF5 to SF of the second embodiment.
FIG. 8 is a waveform chart showing an example of a drive waveform in FIG.

FIG. 10 is a diagram showing a second embodiment of the halftone display method by subfield division.

FIG. 11 is a diagram showing a third embodiment of a halftone display method by subfield division.

FIG. 12 is a block diagram showing a drive circuit of a DC type gas discharge display panel.

13 is a waveform chart showing an example of a drive waveform in the drive circuit shown in FIG.

FIG. 14 is a diagram illustrating an example of an operation when halftone display is performed by subfield division.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gas discharge display panel 2 Cathode drive part 2a Odd line cathode drive part 2b Even line cathode drive part 3 Display anode drive part 4 Anode drive part 5 Cathode 5a Odd line cathode group 5b Even line cathode group 6 Display anode 7 Anode 8 Display cell 9 Auxiliary cell

Claims (4)

[Claims] 1. A scan pulse is sequentially applied to a cathode of a gas discharge display panel in which a plurality of cathodes and an anode are arranged orthogonally and a plurality of discharge cells are formed in a matrix, and a write pulse corresponding to display data is applied to the anode. The discharge is started by causing the discharge cells to start discharging, and by applying a sustain pulse to the cathode in a number that maintains the number of discharges corresponding to a desired emission luminance in a subfield obtained by dividing one field into a plurality of fields. In the method of driving a gas discharge display panel in which the required emission luminance is obtained for each discharge cell by maintaining the number of scan pulses applied to the cathode during a period obtained by subtracting the sustain pulse width from the period of the sustain pulse, Set a fixed number in advance for each subfield,
A method of driving a gas discharge display panel, wherein a cycle of all pulses applied to the cathode and the anode is changed at least once in one field in subfield units. 2. A method in which a plurality of scan pulses are continuously applied to the cathode during a period obtained by subtracting the sustain pulse width from the cycle of the sustain pulse, and a write pulse corresponding to the scan pulse is applied to the anode in synchronization with the scan pulse. When continuously writing display data corresponding to a plurality of rows of cathodes in a sustain pulse cycle, a plurality of scan pulses applied continuously in the sustain pulse cycle are assigned to a plurality of cathode groups obtained by dividing the cathode, 2. The driving method for a gas discharge display panel according to claim 1, wherein a starting point of a scanning pulse started for each subfield is started from a plurality of ends of the plurality of cathode groups and scanned sequentially. 3. The method of driving a gas discharge display panel according to claim 2, wherein the starting point of the scanning pulse in each of the plurality of cathode groups is changed at least once in one field in subfield units. 4. When continuously writing display data corresponding to a plurality of rows of cathodes within a sustain pulse period from the plurality of cathode groups, the order of bits to be written in a subfield for each of the cathode groups is changed by one field. At least one within
The method for driving a gas discharge display panel according to claim 2, wherein the display is performed in a combination different in types or more.