JPS6341079B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for driving a discharge display panel, so-called a plasma display panel.

In this type of plasma display panel (hereinafter abbreviated as display panel), a plurality of generally transparent row electrode groups parallel to each other and a plurality of generally opaque column electrode groups parallel to each other are arranged in a matrix, and both electrodes are arranged in a matrix. A method is generally known in which an ionizable gas is interposed between the groups and the intersection of a selected row electrode and a selected column electrode is displayed by discharge light emission.

In the display panel, an optical image corresponding to the input signal can be displayed by controlling the electrode selection method of the row electrode group and the column electrode group in accordance with the input signal. For example, one of the row electrode groups and the column electrode group, for example, each electrode in the column electrode group, is selected and scanned sequentially in a time-division manner, and each electrode in the other electrode group, for example, the row electrode group, is selected and scanned in sequence. By selectively controlling the electrodes according to the input signal while maintaining synchronization with scanning, an optical image corresponding to the input signal can be displayed on the display panel surface. External electrode type display panels must be driven with alternating current voltage, and the drive signals applied to row electrode groups and column electrode groups include high-frequency pulses called toggle pulses.

The display panel can be driven by applying a drive signal to both the row and column electrode groups as described above, or by applying a drive signal to one of the row and column electrode groups while the other is at ground potential, etc. There is a method in which an intersection point between an electrode to which a drive signal is applied and an electrode clamped to a fixed potential is displayed by light emission by clamping to a fixed potential.

In the above display panel, after being left unlit for a long period of time without discharging and emitting light,
When lighting this, the gas in the display panel is hardly ionized, so it is difficult to be excited, and it takes time to start the discharge after the signal is applied, which has the disadvantage that the so-called turn-on time becomes long.

The present invention is intended to improve the above-mentioned drawbacks, and when the power switch is turned off and the drive signal including toggle pulses supplied to the display panel stops, AC voltage from a commercial AC power source is applied to the display panel to display the display panel. The entire display surface of the panel is dimly lit to shorten the turn-on time when the power is turned on again.

The details of the present invention will be explained below with reference to Examples.

FIG. 1 is a diagram for explaining the operation of row and column drivers of a display panel according to the present invention, and FIG. 2 is a block diagram showing an embodiment of the display panel driving method according to the present invention.

In FIG. 1, display data 1 is input to the base of a first transistor 2, turning the first transistor 2 on and off. When the first transistor 2 is on, the base of the second transistor 3 connected to the collector of the first transistor 2 is pulled down to the ground level via the diode 4.
The second transistor 3 is turned off, the toggle pulse 6 input from the collector does not appear at the emitter, and the drive signal output 7 is connected to the diode 8 and the diode 4.
and is pulled down to the ground level through the collector and emitter of the first transistor 2.

Next, when the first transistor 2 is off,
The toggle pulse 6 appears at the drive signal output 7 via the collector-emitter of the second transistor 3 when it is positive, and via the collector-base of the second transistor 3 and the diode 8 when it is negative.

That is, a drive signal including the toggle pulse 6 is obtained at the drive signal output 7 in accordance with the display data.

In FIG. 2, the input signal 30 is
, the output is controlled by the control pulse 25 obtained from the pulse control section 15 and then input to the row driver 10. The row driver 10 controls the toggle pulse from the toggle pulse generator 14 inputted through the terminals S ₁ ′, S ₀ ′ of the first changeover switch 22 in accordance with the input signal, and outputs a row electrode drive signal to the output thereof. 28 is generated. Row electrode drive signal 28
are applied to corresponding electrodes of the row electrode group 12.

On the other hand, clock pulse 2 from pulse generator 16
6 is converted into a binary number corresponding to the number of electrodes in the column electrode group 13 in the encoder 17. The binary number from the encoder 17 is decoded in the decoder 18, and pulses equal to the number of electrodes in the column electrode group 13 are sequentially generated. , further subjected to output control in the scan control section 19 and then input to the column driver 20.
The column driver 20 controls the toggle pulses from the toggle pulse generator 16 inputted via the terminals S ₁ ″ and S ₀ ″ of the second changeover switch 23 in accordance with the output of the scan control unit 19 , and applies the output to the output. Column drive signal 2
Generates 9. The column drive signal 29 sequentially selectively scans each electrode of the column electrode group 13. Since the selection of the row electrode group 12 corresponds to the input signal 30 and the scanning of the column electrode group 13, an optical image corresponding to the input signal 30 can be displayed on the display panel 11.

The commercial AC power supply 27 is a terminal of the power switch 21.
It is used as a power source for this display device via S ₀ and S ₁ . On the other hand, when the power switch 21 is switched to turn off the display device, the commercial AC power source 27 is input to the primary side of the transformer 24 via the terminals S ₀ and S ₂ , and the display panel is connected to the secondary side of the transformer 24 . A display drive signal 31 is generated which is converted to a suitable voltage for lighting 11.

The first changeover switch 22 and the second changeover switch 23 are both structured to be switched in conjunction with the power switch 21, and the terminals of the power switch 21
When S ₀ and S ₂ are connected, the first switch 2
A display drive signal 31 is input to the row driver 10 via two terminals S ₀ ', S ₂ '. When the power is off, the display data 1 input to the first transistor 2 in FIG. 1 is at a low level, so that the toggle pulse 6 appears on the drive signal output 7. At this time, in FIG. 2, instead of the toggle pulse 6, a display drive signal 31 is applied to the row electrode group 12, while the column electrode group 13 is connected to the ground potential. That is, the display drive signal 31 is always applied to the row electrode group 12 through the row driver 10, and the column electrode group 13 is clamped to the ground potential through the column driver 20.

As described above, the display drive signal 31 is applied between all the row and column electrode groups 12 and 13, and the entire display surface of the display panel 11 is lit.

Normally, the frequency of the pulses included in the row and column electrode drive signals 28 and 29 used to light up the display surface of the display panel 11 is approximately 3KHz to 10KHz per electrode in order to obtain appropriate brightness. Apply 300V. On the other hand, the frequency of the commercial AC power supply 27 applied when the display device is turned off is 50 to 60 Hz, and the luminance of the display panel is approximately proportional to the frequency, so the brightness of the display panel when the display device is turned off is very low. The light emitted from the display panel is practically invisible. Furthermore, since the life of the display panel is approximately proportional to the frequency of the drive signal pulse, the effect of implementing the present invention on the life of the display panel can be ignored.

When the display device is off, the power supplied to the display panel is almost proportional to the frequency of the drive signal pulse and is very small, so the transformer 2
4, a small and inexpensive one can be used.

As described above, according to the present invention, it is possible to very easily and effectively improve the turn-on time of a display panel by simply adding a switch and a small-capacity transformer to a conventional plasma display device. can.

In this explanation, a transformer is used to generate the display drive signal, but if the commercial AC power supply has an appropriate voltage to light the display panel, a capacitor or the like can be used directly to generate the display drive signal.
Of course, the same effect can be obtained by applying a display drive signal to the display panel via a column driver.

[Brief explanation of the drawing]

FIG. 1 is an equivalent circuit diagram for explaining the operation of the display panel, row and column drivers. FIG. 2 is a block circuit diagram showing an embodiment of a plasma display panel driving circuit according to the present invention. 1... Display data, 2... First transistor, 3... Second transistor, 4... Diode, 5... Resistor, 6... Toggle pulse, 7... Drive signal output, 8... Diode, 9 ...Data control unit, 10...Row driver, 11...Display panel, 12...Row electrode group, 13...Column electrode group, 14...Toggle pulse generator, 15...Pulse control unit, 16...Pulse Generator, 17...Encoder, 18...Decoder, 19...Scanning control section, 20...Column driver, 21...Power switch, 22...First changeover switch, 23...Second
changeover switch, 24...Transformer, 25...Control pulse, 26...Clock pulse, 27...Commercial AC power supply, 28...Row electrode drive signal, 29...
Column electrode drive signal, 30...input signal, 31...display drive signal.

Claims (1)

[Claims] 1. In a discharge display panel drive method in which a plurality of electrode groups are arranged facing each other, ionizable gas is interposed between both electrode groups, and a selected intersection of the opposing electrodes is caused to discharge and emit light, all electrodes of the discharge display panel During the period when the common power supply to the control circuit is turned off and the high-frequency drive pulse applied to the input of the discharge display board drive circuit is stopped, an AC voltage from an AC commercial power supply is applied to the input of the drive circuit to lower the discharge display board. A drive method for a discharge display panel that is characterized by emitting light with brightness.