JPS5832385B2 - Self-shifting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a self-shifting gas discharge display device that enables stable shifting operations.

As is well known, plasma display panels are equipped with electrodes covered with a dielectric layer such as low-melting glass in contact with a discharge gas space filled with ionizable gas such as neon, and between adjacent electrodes or opposing electrodes. Once an alternating sustaining voltage is applied and a writing voltage equal to or higher than the discharge start voltage is applied to cause a discharge, the alternating sustaining voltage will cause a continuous discharge, and the discharge light emission will produce a display. It is something that can be done.

Furthermore, the electrodes are periodically connected to multi-phase busbars such as three-phase busbars, and voltages are sequentially applied to these busbars, thereby utilizing the pilot effect of adjacent cells to sequentially self-shift the discharge spot. A method has already been proposed.

FIG. 1 is a block diagram of an example for performing such self-shift, and the plasma display panel 1 has common electrodes y1 to y7 connected to bus line Y, and common electrodes y1 to y7 orthogonal to these common electrodes y1 to y7. Write electrodes W1 facing each other
~w7 and shift electrodes a1.~w7 and periodically connected to the bus lines A, B, C, D. b1. c1. d1. a2. b2゜...
..., and each electrode is covered with a dielectric layer.

Further, 2 is a character generation circuit, 3 and 4 are shift registers, 5 is an oscillator, 6 is a frequency divider, and 7 is an output phase φA of the oscillator 5.
800 phase shifter to make φB, 8 is write driver,
9 and 10 are AND circuits; 11 is a shift driver that applies a shift voltage to bus lines A-D; and 12 is a driver that applies a voltage to bus line Y.

The output of the oscillator 5 is frequency-divided by a frequency divider 6, and the shift register 4 is driven by the frequency-divided output.

Since this shift register 4 has four bus lines A to D, it is a 4-bit shift register, and the shift driver 11 is driven by the output of each stage, and a voltage consisting of a pulse train is sequentially applied to the bus lines A to D. Application is switched according to the shift speed.

Further, since the driver 12 is driven by the output of the phase shifter 7, a voltage consisting of a pulse train having a phase difference of 1800 degrees from the voltage applied to the bus lines A-D is applied to the bus line Y.

When display information is input to character generation circuit 2, a write signal is generated in response to the output of shift register 3.

When displaying one character with 5.times.7 dots, the shift register 3 can be made, for example, a 7-bit shift register to provide a spacing between characters corresponding to 2 bits.

Write driver 8 according to the write signal from character generation circuit 2
is driven and a write voltage is applied to the write electrodes w1 to w7, a discharge spot is generated between the common electrodes y1 to y7, and the discharge spot is moved to the right by the shift voltage applied to the bus line A-D. shift.

In the self-shifting gas discharge display device described above,
The biggest problem in the past has been the small operating margin.

A major cause of this is local variations in operating voltage within the panel.

Therefore, in order to increase the operating margin, it is necessary to reduce this variation as much as possible.

FIG. 2 is an explanatory diagram of the operating margin in the case of a single cell.

In the graph shown, the horizontal axis is the distance from the cell that is in the ignition state and generates a discharge spot, and 1 is the ignition cell 0.
2 indicates the position of the first electrode, which is 0.6 meters away from the ignition cell O, and 2 indicates the second electrode position, which is 1 or 2 meters away from the ignition cell O.

Also, Vf1 on the vertical axis is the ignition voltage when the pilot flame is next to it,
Vf2 indicates the ignition voltage when two electrode pitches are away from the pilot flame.

The margin for the shift operation is how much lower the ignition voltage f1 of the first electrode is compared to the ignition voltage f1 of the second electrode, and the larger the difference, the larger the margin. .

In other words, the difference between the ignition voltage Vf on the electrode adjacent to the discharge spot serving as the pilot flame and the ignition voltage Vf on the electrode 2 pitches away from the pilot flame - f - vf is the shift margin, and if this margin is exceeded, A misshift of the discharge spot occurs.

However, in an actual panel, variations in the ignition voltage of each cell are unavoidable due to dimensional accuracy, and the shift margin seen from the overall panel becomes significantly smaller.

Regarding the ignition voltage, suppose Vf is 150■, and vf is 1
80■, the theoretical margin for a single cell shown by curve a in FIG. 2 is about 30V.

However, when looking at each cell in different areas on the same panel individually, between the cells in the discharge area shown by the curves in FIG. 2 and the cells in the discharge area shown by curve C, the curve a There is a variation of 2■1 in the ignition voltage of the first electrode above and below the set shift voltage based on , and the variation v1 on one side is assumed to be 15V, and the variation v2 on one side in the ignition voltage of the second electrode is assumed to be 15V. ■If we assume that 5 is the margin in the actual panel.

In this way, with a small margin, there is a good possibility that malfunctions will occur due to variations in power supply voltage or changes in characteristics due to lifetime.

An object of the present invention is to provide a drive section with adaptability to variations in ignition voltage in different discharge regions (cells) within a panel, in order to eliminate the above-mentioned problems in conventional self-shifting gas discharge display devices. The purpose of the present invention is to provide a display device that is durable.

According to the present invention, the shift area of the panel is divided into two or more areas in the shift direction, and a plurality of shift electrodes included in each area are connected to a shift power source specific to each area. This is achieved by driving with a shift voltage set for each region.

The present invention will be described below with reference to the drawings.

FIG. 3 is a block diagram of a panel showing one embodiment of the present invention.

In FIG. 3, the panel is divided into a right side area R and a left side area, and the shift electrode included in the right side area R is connected to the generatrix A1.
~D1, and the shift electrodes included in the left region are periodically connected to bus lines A2~D2.

Therefore, different voltages can be set for the right region R and the left region R according to the characteristics of each part of the panel, so that the shift operation can be performed in an optimal state.

Therefore, when looking only at the right or left side of the panel, the variation in ignition voltage of the cells included in each area is smaller than the variation when looking at the cells throughout the panel.
Even if the operating margin of the entire panel is small, the operating margin of the right and left regions becomes larger, making it easier to drive.

FIG. 4 is an explanatory diagram of the operation of the apparatus shown in FIG. 3.

In the figure, 42 ports indicate the range of variation in ignition voltage across the entire panel, and when this panel is driven by a common power source as in the past, the shift voltage is set to VSN in between.

However, in this case, if the range of variation of 42 ports is 20V
If so, in the case of the above operation example, the margin is IOV
It's nothing more than that.

On the other hand, if we look at the variation in cells in the right region R when the panel is divided into two as shown in Figure 3, this will be, for example, 12V in the range C.2, and the shift voltage will be set to V.
If set to SN+, a margin of 18V will be obtained in this right region.

Further, the variation of cells in the left side region is in the range E and E, and if this is set to 14V, a margin of 16V can be obtained in this left side region.

Note that the set shift voltage in the left side area is indicated by V S N 2.

The operating margin of the individual regions is thus increased.

In this embodiment, the case where the panel is divided into two has been described, but in the present invention, when the panel is thick, it can be further divided into three or more.

The more it is divided, the more the apparent variation decreases.

Further, the present invention is not limited to the four-phase self-shift type.

As explained above, according to the present invention, the drive section can be made adaptable to variations in ignition voltage characteristics in different discharge regions within the panel, which has the effect of apparently reducing variations, and Its advantages are very unique, such as the fact that it can be used even in large panels.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a known self-shift 1 drive system, and FIG. 2 is an explanatory diagram of the operating margin in the case of a single cell.
FIG. 3 is a block diagram of a panel showing an embodiment of the present invention, and FIG. 4 is an explanatory diagram of the operation of the apparatus shown in FIG. 3. In the figure, A, B, C, and D are shift bus bars, al t
b, j cl t dlj a2, "" is a shift electrode, 2 is a character generation circuit, 3 and 4 are shift registers, 5 is an oscillator, 6 is a frequency divider, 7 is a phase shifter, 8 is a write driver , 9 and 10 are AND circuits, 11 is a shift driver, 12 is a driver, A1 to D1 are shift electrodes on the right half of the panel, and A2 to D2 are shift electrodes on the left half of the panel.

Claims (1)

[Claims] 1 Divide the shift area of the panel into two or more areas in the shift direction, connect multiple shift electrodes included in each area to a shift power supply specific to each area, and drive with a shift voltage set for each area. A selfie that is characterized by
Shift type gas discharge display device.