JPH0673064B2 - Discharge display device - Google Patents

Description

The present invention relates to a discharge display device (plasma display panel).
Regarding

Background art and its problems An XY matrix type discharge display panel is known as one of the means for displaying characters and images. X electrode group (information electrode)
Is provided with a high voltage and a low voltage corresponding to the display information at the anode, for example. The Y electrode group (scanning electrode) is line-sequentially scanned by the cathode (application of a negative voltage pulse).

The applicant of the present invention has proposed a discharge display device in which a trigger electrode is added in addition to the XY electrode in Japanese Patent Application No. 56-128470. This trigger electrode is arranged, for example, in the vicinity of the cathode electrode via an insulating layer, and by applying a high voltage in accordance with the cathode scan, a pilot discharge (induced discharge) is generated between the trigger electrode and the cathode electrode. I am letting you. As a result, the discharge between the anode and the cathode is facilitated to reduce the drive voltage, and the variation in the discharge delay of each discharge cell is made uniform to improve the flickers. A trigger electrode may be provided near the anode electrode via an insulating layer.

In such a discharge display panel of the trigger discharge type, since the pilot discharge is caused between the surface of the insulating layer on the trigger electrode and the cathode electrode (or the anode electrode) to induce the main discharge, There is a problem that the surface of the insulating layer and the surface of the discharge electrode are contaminated by the sputtering and the stable discharge characteristics cannot be obtained for a long period of time. Further, if the linear density (display resolution) of the discharge electrode is increased, the surface area of the insulating layer exposed in the discharge space on the trigger electrode is reduced. Therefore, in order to ensure the induced discharge, the trigger voltage must be increased. There is a problem that does not become

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and can reduce discharge driving voltage, uniform discharge delay (improvement of flickers), and discharge characteristics due to dirt on electrodes or insulating layer surface. It is an object of the present invention to provide a discharge display device which does not change with time and operates with a low trigger voltage even if the linear density of the discharge electrode is increased.

SUMMARY OF THE INVENTION A discharge display device according to the present invention includes a discharge electrode pair (anode electrode 3 and cathode electrode 4) arranged with a discharge space therebetween, and a dielectric layer in the vicinity of one discharge electrode (for example, the anode electrode 3).
By applying a pulse having the same polarity as the drive voltage of the above-mentioned one discharge electrode and the trigger electrode 6 arranged via 10 to the trigger electrode in synchronization with the selection of the discharge cell, a pulse differential to the above-mentioned drive voltage is obtained. And a trigger means (trigger circuit 9) for superimposing With this configuration, the discharge driving voltage is reduced, flicker is improved, and stable operation for a long time is obtained.

Examples The present invention will be described below based on examples.

FIG. 1 shows a discharge display device (plasma.
This is a schematic plan view of a display panel (PDP). This discharge panel is an XY matrix-shaped anode electrode 3 (information electrode) and cathode electrode 4 (scanning electrode) separated by a minute discharge space.
Is equipped with.

Every other anode electrode 3 is connected to the upper and lower anode drive circuits 7A and 7B, and display data input (serial)
Based on the drive circuit 7A, 7B through the shift register (parallel output) and the switching output element, the high-voltage "1" or low-voltage "0" information voltage (V _{A in} FIG. 3) corresponding to the display information of the cathode It is given in synchronization with scanning.

A negative voltage (V _{K in} FIG. 3) is applied to the cathode electrode 4 line by line from top to bottom by the cathode scanning circuit 8, and the selected cathode electrode 4 and the anode electrode 3 to which a high voltage is applied.
Discharge light emission is generated between and.

FIG. 2 is a partial cross-sectional view of a conventional discharge display panel,
Below the cathode electrode 4, a plurality of phases (8
The trigger electrodes 6 separated into phases are arranged along (parallel to) the cathode electrodes 4. In addition, 1 is a front glass and 2 is a back glass, and the anode electrode 3, the cathode electrode 4, and the trigger electrode 6 are enclosed between these front and back glasses 1, 2.

The trigger electrodes 6 are phase-sequentially driven by a trigger circuit 9, and a high-voltage pulsed trigger voltage shown by V _T in FIG. 3 is applied to the trigger electrodes 6 of the selected phase together with the cathode scanning timing. Then, a pilot discharge (induction discharge) is generated between the trigger electrode 6 and the facing cathode electrode 4, and the discharge start voltage between the cathode and the anode is lowered by the space ions generated by this discharge, so that the main discharge between the anode and the cathode is generated. Be attracted.

As described above, conventionally, the trigger electrode 6 is applied with a pulse voltage having a polarity opposite to that of the applied voltage of the discharge electrode (cathode electrode 4 in FIG. 2) in the vicinity of the trigger electrode 6, and the voltage is applied between the surface of the insulating layer 5 and the discharge electrode. A pilot fire discharge was generated to induce the main discharge. For this reason, the discharge characteristics are deteriorated with time due to dirt on the surface of the insulating layer 5 and the discharge electrode, and when the linear density of the discharge electrode is increased to obtain a high resolution display, a high trigger voltage must be used. There was a problem.

In the present invention, the differential pulse is superimposed on the discharge electrode by utilizing the capacitive coupling between the trigger electrode and the discharge electrode (anode or cathode) which is in close proximity to the trigger electrode to make the discharge delay time of each cell uniform, -To reduce the drive voltage between the cathodes.

FIG. 4 is a partial cross-sectional view of the discharge display panel according to the embodiment of the present invention, in which the trigger electrode 6 is provided on the back side of the anode electrode 3 via the dielectric layer 10. The trigger electrode 6 may be divided into a plurality of phases as shown in FIG.
It may be a surface electrode that covers the entire display surface. Further, it may be a parallel electrode along each anode electrode 3. Further, the anode electrode 3 side may be the rear glass 2 and the cathode electrode 4 side may be the front glass 1 (display surface), but the anode electrode 3 side may be the front glass. In the latter case, the trigger electrode 6 is a transparent electrode.

Each anode electrode 3 is driven by an anode drive circuit 7 including transistors Q1 and Q2, a diode D and a resistor R shown in FIG. That is, as shown in the waveform diagram V _A of FIG. 5, in the selected discharge cell, the transistor is supplied by the information input.
When Q1 is turned on, the drive voltage V _A is applied to the anode electrode through the diode D and the resistor R. In the non-selected discharge cell, the transistor Q2 turns on and the bias voltage V _B
Is given.

A pulse having the same polarity as the anode drive pulse as shown in _VT in FIG. 5 is applied to the trigger electrode 6 from the trigger circuit 9 in synchronization with cell selection. Then, the potential of the anode electrode 3 is differentially pushed up through the capacitive coupling between the trigger electrode 6 and the anode electrode 3 as shown by V _A + V _T in FIG. As a result, the discharge start between the anode and the cathode in the selected cell is forced, the discharge delay time is speeded up, and high-quality display free of flickering interference is obtained.

_A differential waveform is also applied to the non-selected cells as shown in FIG. 5 V _A , but since it is only superposed on the bias voltage V _B , there is no delay until the discharge start voltage and the addition time Since it is short, it does not cause a false discharge.

According to this configuration, since the pilot fire discharge is not used, there is no deterioration in discharge characteristics over time due to stains on the electrode surface or the insulating layer surface, and stable display performance can be obtained over a long period of time. Further, since the capacitive coupling between the anode electrode 3 and the trigger electrode 6 is utilized, even if the linear density of the discharge electrode is increased, the trigger characteristic is not affected, and therefore even a low trigger voltage is ensured. It is possible to perform triggering.

In the structure in which the trigger electrode 6 is arranged below the cathode electrode 4 as shown in FIG.
An information voltage such as V _K is applied, while the anode electrode 3
In the case where the high pressure pulse is applied line-sequentially as the scanning electrode, a negative trigger pulse may be applied in synchronous with the information voltage, such as FIG. 6 V _T to the trigger electrode 6. In this case, a negative differential pulse like V _K + V _{T in} FIG. 6 is superposed on the cathode electrode 4 by capacitive coupling via the insulating layer 5. Therefore, this also makes the discharge delay time uniform,
A flicker-free discharge display can be obtained.

Although the differential pulse is superimposed on the information electrode in the above-described embodiment, the trigger electrode is provided below the scan electrode (anode or cathode) via the insulating layer and differentiated into the scan voltage waveform via capacitive coupling. Similar effects can be obtained by superimposing pulses.

As described above, according to the present invention, a trigger electrode is provided in the vicinity of an anode electrode or a cathode electrode via a dielectric layer, and a pulse (differentiation) is applied to an anode drive voltage or a cathode drive voltage by utilizing capacitive coupling with the trigger electrode. Since the pulse) is superposed, the superposed pulse forces the discharge start, the discharge delay time of each cell is made uniform, and a high-quality display without flickers can be obtained. Further, the discharge driving voltage between the anode and the cathode can be substantially reduced, and the circuit cost can be reduced. Further, in the conventional type in which the trigger electrode is driven by a pulse of opposite polarity to cause a pilot discharge, deterioration of the discharge characteristics with time due to contamination of the electrodes in the tube and the surface of the insulating layer occurred, but the present invention uses capacitive coupling. Since all pulse superposition methods are used, stable performance can be obtained over a long period without deterioration of characteristics.

[Brief description of drawings]

FIG. 1 is a schematic plan view of a discharge display device to which the present invention is applied,
FIG. 2 is a partial sectional view of a discharge display device showing a conventional arrangement position of a trigger electrode, FIG. 3 is a drive waveform diagram of each electrode of a conventional anode, cathode and trigger, and FIG. 4 is an embodiment of the present invention. FIG. 5 is a partial sectional view of the discharge display device, FIG. 5 is a drive waveform diagram of the anode and the trigger electrode of FIG. 4, and FIG. 6 is a drive waveform of the cathode and the trigger electrode when the trigger electrode is provided near the cathode electrode. It is a figure. In the reference numerals used in the drawings, 3 ... Anode electrode 4 ... Cathode electrode 6 ... Trigger electrode 10 ... Dielectric layer.

Claims (1)

[Claims] 1. A pair of discharge electrodes arranged with a discharge space therebetween, a trigger electrode arranged in the vicinity of one discharge electrode via a dielectric layer, and a pulse having the same polarity as the drive voltage of the one discharge electrode. And a trigger means for superimposing a differential pulse on the drive voltage by applying to the trigger electrode in synchronization with the selection of the discharge cell.