JPH04127194A - Gas discharge display driving device and its driving method - Google Patents

Abstract

PURPOSE:To prevent a flicker from being generated owing to fluctuations of brightness between nearby lines by providing a means which divides a field large in time rate and separates the divided fields mutually at constant time intervals on the input side of a display period setting means. CONSTITUTION:The field dividing and separating means 4 which divides the field large in time rate and separates the divided fields mutually at the constant time intervals is provided on the input side of the display period setting means 2. Then when one frame is divided into the fields and a gradational display of data is made, the field which is large in time rate is further divided to increase the display inversion frequency in the field apparently. Consequently, even when a combination of gradations where nearby lines of a display panel are inverted in display period is obtained, a flicker is prevented from being generated at the border between those lines.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a gas discharge display driving device and its driving method for driving a gas discharge display panel such as a plasma display panel that utilizes light emission from gas discharge to display data in gradations. The purpose of this method is to divide one frame into multiple fields in order to prevent flicker from occurring due to brightness fluctuations between adjacent lines when one frame is divided into multiple fields to display data in gradations. field forming means for forming a plurality of fields having a predetermined copper content ratio; display period setting means for setting a data display period for each field in response to an external data signal;
and a driver for displaying the data in gradation by driving the gas discharge display panel by the set display power, and divides the field with a large presnoring time ratio, and divides the divided field into a constant field. Field division/separation means for separating each other at time intervals is provided on the input side of the display period setting means, or the one frame is divided to form a plurality of fields having a predetermined time ratio. , in a gas discharge display method for displaying data in gradation by driving a gas discharge display panel for a display period set for each field according to an external data signal, the field having a large time ratio; is further divided, and the divided fields are separated from each other at regular time intervals.

[Industrial Application Field] The present invention relates to a gas discharge display driving device and a driving method thereof for driving a gas discharge display panel such as a plasma display panel that utilizes light emission from gas discharge to display data in gradations.

Among the peripheral equipment in the combinatorial system, CRT
Display devices such as the above (hereinafter referred to as displays) have the function of visually displaying various data input from a keyboard or the like, and play an important role as an interface between humans and machines. Furthermore, in recent years, with the diversification of application fields for computer systems, there has been a demand for higher performance, smaller size, and lighter weight for the above-mentioned displays, and for this reason, the development of flat displays to replace CRTs is progressing rapidly. It is being

Among gas discharge display panels, which are a type of flat display, there are AC-type plasma display panels (hereinafter abbreviated as AC-FDP) that have a self-memory display function, and those that have a memory and display function using a pulse memory drive method. It is known that a direct current type plasma display panel (hereinafter abbreviated as DC-FDP) can display data at each display position on a display screen at an arbitrary level II (brightness). The present invention refers to a gas discharge display driving device for driving a gas discharge display spring panel, such as an AC-FDP, equipped with this gradation display function, and a gas discharge display driving method therefor.

[Conventional technology]

FIG. 8 is a diagram showing a conventional gas discharge display driving device.

However, here, as a representative example of the gas discharge display panel 7, an FDP (for example, AC-FDP) 8 with a gradation display function is used.

In FIG. 8, the FDP 8 has a plurality of X electrodes 6-1 and Y electrodes (also called lines) 6-2 arranged in a matrix. Furthermore, these X electrodes 6-
X-side driver 3-1 and Y-side driver 3-2 (in Fig. 8, X- (abbreviated as DRV and Y-DRV) are provided. Furthermore, a scan controller 5 is provided on the input side of the Y-side driver 3-2. The scan controller 5 divides the data of each line into frames based on a vertical synchronizing signal VSY)Ic and horizontal synchronizing signals H8Y and c from an external control circuit. On the other hand, at the input end of the X-side driver 3-2, there is field forming means consisting of a delay circuit 10 for arranging a plurality of fields obtained by dividing the frame in a predetermined order, and data from an external control circuit. Display period setting means comprising a line selector 20 is provided for setting the data display (lighting) period for each field in accordance with the signal DATA.

More specifically, as shown in FIG. 9, the delay circuit 1o delays input data DO to D4 of each bit (bit "O" to pit "4") of the data signal DAT^ by different delay times. Delay line selector 2
It is composed of a plurality of delay lines 10-1 to 10-4 for inputting to 0. However, in this case, the input data DO corresponding to bit "0" is directly input to the line selector 20 without passing through the delay element. Furthermore, if the selection signal output from this line selector 20 is input to the X-side driver 3-1, the X-side driver 3-1 operates only for the period selected by the selection signal within one frame, and one line lights up. Therefore, in this case, the lighting time ratio within one frame changes from the 32 combinations expressed in the five fields, making it possible to display data in 32 gradations.

FIG. 10 is a time chart for explaining the above gradation display operation. In this case, 5
The time ratio of the two fields is set in advance to be 1:2:4:8:16, and the data display in each field is changed according to the value (“1” or “0”) of the input data DO to D5. Whether it is necessary (on or off) is specified.

For example, when the input data is "1", the light is turned on (indicated by a thick solid line), and when the input data is "0", the light is turned off (indicated by a broken line). By combining the above lighting states, 32 brightness levels from 0th to 32nd gradation are expressed in a geometric gradation format. For example, input data DO of bit "0" and bit "2".

When D2 is "1" and other input data are "0", the fifth brightness level is expressed. After the gradation display in one frame is completed, the frames move one after another and the gradation display is performed continuously. As this frame moves, data having a desired brightness level can be displayed on each line on the display screen.

[Problem to be solved by the invention]

As mentioned above, in the conventional gas discharge display drive circuit, one frame is divided into multiple fields, and the display (lighting) period is changed by specifying whether or not to display data for each field. It was displaying gradations.

However, in this case, there are combinations of gradations in which the lighting periods are inverted within one field and are located between adjacent lines (for example, the 15th and 16th in FIG. 10).
), a problem arises in that flicker occurs due to brightness fluctuations at the boundaries of those lines, making it difficult to see the displayed data. This flicker problem is
This is particularly noticeable when the difference in brightness levels is small, as shown by the combinations of adjacent gradations circled in FIG. 10.

The present invention has been made in view of the above problems, and is intended to prevent flicker from occurring due to fluctuations in brightness between adjacent lines when one frame is divided into a plurality of fields and data is displayed in gradation. It is an object of the present invention to provide a gas discharge display driving device and a driving method thereof that are capable of driving the gas discharge display.

[Means to solve the problem]

FIG. 1 is a block diagram showing the basic configuration of the present invention. However, here, of the two types of drivers (FIG. 8), only the X-side driver 3-1 is illustrated as the drive section 3. Regarding the components similar to those mentioned above,
They are indicated by the same reference numbers.

As shown in FIG. 1, the present invention includes field forming means 1 that divides one predetermined frame to form a plurality of fields having a predetermined time ratio, A display period setting means 2 for setting the data display period for each field, and a driver 3 for driving the gas discharge display panel 7 for the set display period to display the data in gradation. In the gas discharge display driving device, the field dividing/separating means 4 divides the field having a large time ratio and separates the divided fields from each other at regular time intervals.
is provided on the input side of the display period setting means 20.

Alternatively, in order to solve the above problem, one predetermined frame is divided into multiple fields having a predetermined time ratio, and each field is set according to an external data signal. In the gas discharge display method for displaying data in gradation by driving the gas discharge display panel 7 for a display period, the field having a large time ratio is further divided, and the divided fields are divided at regular time intervals. I try to separate them from each other.

[For production]

In the present invention, focusing on the fact that flicker is less likely to occur if the speed at which the data display period is reversed between adjacent lines (display reversal frequency) is high, at least two fields with a large time ratio are set for one frame. By dividing the data into multiple parts and dispersing them in time, the display period for data with a large lighting ratio will be shortened, and the display inversion frequency will be large (for example, doubled when split into two). , there is no possibility of flicker occurring even in the case of a combination of gradations in which display periods are reversed between adjacent lines.

Thus, the present invention provides a gas discharge display pulsating device and its drive that does not cause flicker to occur between adjacent lines and make it difficult to see displayed data when one frame is divided into a plurality of fields to display data in gradations. It becomes possible to provide a method.

〔Example〕

FIG. 2 is a circuit diagram showing one embodiment of the present invention.

However, in this case as well, a PDP 8 with a gradation display function will be exemplified as the gas discharge display panel 7.

In this PDP 8, for example, '640X 400 lines (7
)XYi poles 6-1, 6-2 are arranged in a matrix,
In addition, data is displayed in gradations using frame control.

Furthermore, as field forming means 1, a first buffer memory 11 is provided. This first buffer memory 1
1 is input data DO- of multiple bits (5 bits in FIG. 2) sent from an external control circuit (e.g. CPU).
Each of D5 is temporarily held and delayed by a fixed delay time. Furthermore, a second buffer memory 14 is provided as field division/separation means 2. This second buffer memory 14 further delays a part of the delayed data output from the first buffer memory 11 by a certain period of time and inputs the delayed data to the line selector 12 (corresponding to the display period setting means 2 in FIG. 1). It is something to do.

This line selector 12 is also called a decoder, and after the binary delayed data is decoded in this decoder, it is input to the X-side driver 3-1. The X-side driver 3-1 latches a portion of the data after the decoding process, and then supplies the data as parallel data signals to the plurality of X electrodes 6-1 of the PDP 8 almost simultaneously. On the other hand,
Vertical synchronization signal Vsywc and horizontal synchronization signal Hsv
) For each frame divided by the scan controller 5 based on 1, a predetermined voltage is supplied from the Y-side driver 3-2 to a specific selected line, and data is displayed.

FIG. 3 is a diagram showing voltage waveforms at various parts in FIG. 2. Third
As is clear from the figure, the horizontal synchronization signal Hs Y N C
Multiple bits of data are output from the line selector 12 and the X-side driver 3-1 based on the latch signal generated within one cycle. Further, voltage pulses necessary for various display operations such as writing data and erasing stored display data are applied to each electrode of the X-side driver 3-1 and the Y-side driver 3-2.

FIG. 4 is a diagram showing details of the main part of FIG. 2.

Here, the first buffer memory 11 includes a plurality (for example, four) of delay lines 11-1 to 11-4 such as semiconductor memories. In this case, input data D1 to D4 corresponding to bits "1" to "4" are transferred to the delay line 11.
-1 to 11-4 respectively, and bit “O”
It is assumed that the input data DO corresponding to is not passed through the delay line. Furthermore, if one frame is 167, input data D1, D2 . Delay times T, 3T, 15T and 7T are added to D3 and D4, respectively. That is, the configuration is such that the conventional arrangement of the delay lines shown in FIG. 9 is partially changed. On the other hand, the second buffer memory 14 is constituted by a delay line 14-1 with a delay time of 16T. This delay line 14-1 further delays the delay data output from the delay line 11-4 by 16T to generate sixth delay data d5. Therefore, the four delayed data dO~ generated by the first buffer memo 'Jll-1
In addition to d4, the delay data d5 is newly input to the line selector 12. Therefore, data gradation is displayed using these six delay data dO to d5.

FIG. 5 is a time chart for explaining the second gradation display operation. In Fig. 5, the time ratio and lighting order of fields within one frame are changed from the conventional (Fig. 10).
Instead of setting it to 1:2:4:8:16 like
:2:4:8 (16/2):8:8 (16/
2) is set. However, here, 8. (16/
2') indicates each of two fields obtained by dividing a field with a time ratio of 16.

That is, in this case, is the input data D4 corresponding to the field with the largest time ratio different delay times? T,
23T is added to divide the above field into two, and the two are separated by a fixed time interval of 8T. In this way, the time ratio of fields within one frame is suppressed to a maximum of 8, and the order of the fields is rearranged to appropriately distribute the display data, so the display inversion frequency within the field appears to be high. (approximately twice as much) flicker can be prevented.

FIG. 6 is a circuit diagram showing a modification of this embodiment.

However, here, the main parts of the drive device are shown in an enlarged manner.

In FIG. 6, delay times T.15T, 3T and 7T are added to input data Di, D2, D3 and D4, respectively. That is, the configuration is such that a part of the arrangement of the delay lines in FIG. 4 is further changed. Furthermore, the second buffer memory 14 is constituted by two delay lines 14'=1·14'-2 with a delay time of 16T. Of these, the delay lines 14'-1 are the delay lines 11'-3.
and a delay time of 1 to the input data D3.
Delay data d5 to which 9T is added is generated. On the other hand, delay data 14'-2 is connected to delay line 7T, and generates delay data d6 by adding delay time 23T to input data D4. Therefore, seven delay data d[1-d5 are input to the line selector 22.

FIG. 7 is a time chart for explaining the gradation display operation of FIG. 6. In Figure 7, the field time ratio and lighting order are 1 = 2:4 (8/2).
: 8 (16/2) : 4 : 4 (8/2
) :8 (16/2). However, here, 4 (8/2) indicates two fields obtained by dividing a field with a time ratio of 8. That is, in this case, each of two fields having a relatively large time ratio is divided into two and then separated at different time intervals. If you do this,
In the combinations of ■ to ■ and [Yes] and ■ in Figure 5, the display data is dispersed and the display inversion frequency within the field becomes higher, so flicker can be prevented more reliably than in the case of Figure 5. can.

〔Effect of the invention〕

As explained above, according to the present invention, when one frame is divided into a plurality of fields to display gradation of data in a gas discharge display driving device or the like, a field having a large time ratio is further divided and the fields are divided into the fields. By making the display inversion frequency appear higher, even when there is a combination of gradations where the display period is inverted between adjacent lines on the display panel, flickering is prevented from occurring at the boundaries of those lines. It becomes possible to do so.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the principle configuration of the present invention, FIG. 2 is a circuit diagram showing an embodiment of the present invention, FIG. 3 is a diagram showing voltage waveforms at each part of FIG. 2, and FIG. 2, FIG. 5 is a time chart for explaining the gradation display operation in FIG. 2, FIG. 6 is a circuit diagram showing a modification of this embodiment, and FIG. 7 is a diagram showing details of the main parts of FIG. 6th
8 is a diagram showing a conventional gas discharge display driving device, FIG. 9 is a diagram showing details of the main parts of FIG. 8, and FIG. FIG. 9 is a diagram for explaining the gradation display operation of FIG. 8; In the figure, 1... Field forming means, 2... Display period setting means, 3... Driver, 4... Field division/separation means, 7... Gas discharge display panel.

Claims (1)

[Claims] 1. Field forming means (1) for dividing one predetermined frame to form a plurality of fields having a predetermined time ratio; a display period setting means (2) for setting a data display period for each data display period; and a driver (2) for driving the gas discharge display panel (7) for the set display period to display the data in gradation.
3) In the gas discharge display driving device, field division/separation means (4) for dividing the field having a large time ratio and separating the divided fields from each other at regular time intervals is provided in the display period. A gas discharge display driving device characterized in that it is provided on the input side of a setting means (2). 2. Divide one predetermined frame to form a plurality of fields having a predetermined time ratio, and display the gas discharge display panel ( 7) A gas discharge display method for displaying data in gradation by driving the field, characterized in that the field having a large time ratio is further divided, and the divided fields are separated from each other at regular time intervals. Gas discharge display driving method.