JPS5836915B2 - Writing method of self-shifting gas discharge panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a self-shifting gas discharge panel that includes:
This invention relates to a new writing method with increased operating margin.

Self-shifting gas discharge panels are capable of sequentially shifting discharge spots generated from one end of the panel according to written information toward the other end, and displaying the written content statically when the writing operation is completed. type has been proposed.

Recently, however, in this type of gas discharge panel, a so-called double spot method, in which two adjacent discharge points are simultaneously lit, has been adopted for the purpose of ensuring a reliable shift operation and increasing a shift margin.

In such a double spot method, in the writing step of writing information, a discharge spot is generated in a writing discharge cell provided at one end according to the information, and
This is done in such a way that a discharge spot is simultaneously generated in a shift discharge cell adjacent to the write discharge cell by utilizing the pilot effect of the spot.

To describe this information writing system in a little more detail, FIG. 1a shows the driving voltage waveforms Vw and VA applied to the write discharge cell W in FIG. 1b and the shift discharge cell A adjacent thereto in the information writing step. Give an example.

In the case of the figure, the write step consists of four cycles, and in each cycle, write voltage pulses and shift voltage pulses of the same waveform are applied to write discharge cells W and shift discharge cells A, respectively.

As shown in the figure, during the write step, a write pulse Pw is sequentially applied to the write discharge cell (discharge point) W at the l end according to the input information, so that the write discharge cell is placed at the first discharge spot. is occurring repeatedly.

At this time, shift pulses Ps are sequentially applied to the shift discharge cells A adjacent to the write discharge cell, and therefore a discharge spot is simultaneously generated in the discharge cell A due to the pilot effect of the write discharge spot. It turns out.

As is well known, as the application of the shift pulse train is sequentially switched in the next shift step, the discharge spot generated in the shift discharge cell A is distributed along the shift discharge cell array in a manner that shares two adjacent discharge cells. Shifts sequentially toward the ends.

During this time, an erase pulse is applied to the write discharge cell W to erase the discharge spot.

The self-shifting gas discharge panel that enables double spot operation as described above and its driving method are disclosed in Japanese Patent Application No. 51-824 assigned to the same assignee as the present application.
It is described in detail in the specification of No. 10.

By the way, the voltage level of the write pulse Pw for generating a discharge spot at the write discharge point W is the minimum voltage value that can generate a discharge spot large enough to enable a shift operation at the write discharge point. V wmjR and
It is selected to be between the maximum voltage value Vwmax that can generate a discharge spot of a size that does not cause unnecessary discharge at the write discharge point of an adjacent line.

Here, the difference between these voltage levels (Vwmax − V
wmijL) is defined as the write operation margin.

Furthermore, the pilot effect that contributes to the shift operation is, as is already well known, when a discharge spot exists at a certain discharge point, electrons, ions, and metastable atoms generated at the discharge point diffuse to adjacent discharge points. This is a phenomenon in which the ignition voltage at the adjacent discharge point is lower than normal.

Therefore, the pulse voltage level for such a shift operation is reduced by the ignition voltage Vsmi! of the adjacent discharge point due to the pilot effect. ignition voltage Vsma of a remote discharge cell higher than t and simultaneously energized through a common conductor
is chosen lower than x.

Here, the difference between these voltages (VsmaxV s mvt)
is defined as the margin of the shift operation.

As is already well known, the larger the shift margin and write margin described above are, the more stable the gas discharge panel can be driven against fluctuations in the power supply voltage, and the lower the pulse voltage, the more stable the drive circuit will be. Since voltage can be applied, it can be made smaller and less expensive by integrating circuits or the like.

In the driving method that adopts the double spot method described above, in the information writing step, the range where these two margins overlap becomes the actual operable area, and according to the conventional panel using the driving waveform shown in FIG. The margin characteristics shown in the figure are obtained.

In other words, in FIG. 2, the horizontal axis shows the voltage value Vw of the write pulse, and the vertical axis shows the voltage value Vs of the shift pulse. Since chipping occurs and the discharge spot becomes difficult to shift, it was necessary to increase the write voltage level.

For this reason, the write margin becomes extremely small, making it impossible to obtain a stable and reliable write operation in practical use, and also making it difficult to integrate the write drive circuit.

If the shift voltage level is increased, the write voltage can be lowered and the write margin can be increased, but in this case, the shift margin becomes smaller and a reliable shift operation cannot be obtained. It becomes difficult to integrate the shift drive circuit into an integrated circuit.

The present invention was made in view of the above points, and based on the experimental result that the pulse width of the write pulse applied to the write discharge point has a large effect on the shift operation, the waveform of the write pulse is improved to perform write and The present invention provides a new writing method that increases the shift margin and allows the pulse voltages to be set low.

Briefly stated, the present invention provides that, when writing information, the pulse width of the write pulse 0 of at least the final cycle of the write pulse train applied to the write electrode during the write step is greater than the pulse width of the shift pulse applied to the adjacent shift electrode. It is also characterized by making it smaller.

By applying such a narrow write pulse, a sufficient amount of the space charge generated based on the discharge spot generated at the write discharge point is supplied to the adjacent shift discharge point, and the shift discharge This makes it easier for discharge to occur at the point.

Incidentally, when the pulse width is the same as or longer than that of the shift pulse, as in the case of the conventional write pulse shown in Figure 1, the charged particles generated by the discharge can reach the dielectric layer (coating layer of the electrode). This makes it impossible to supply a sufficient amount of space charge to adjacent discharge points.

Therefore, it was necessary to compensate for the lack of pilot effect by increasing the write voltage to increase the amount of charged particles generated at the write discharge point, or by applying a large shift voltage.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.

FIG. 3 shows the waveform Vw of the write voltage pulse and the shift voltage pulse VA of the embodiment of the present invention applied in the information writing step. τ
It is smaller than S.

When such a writing pulse was applied to the gas discharge panel, we measured how the minimum writing voltage Vwmm and minimum shift voltage Vsmm changed due to this narrow pulse, and the results shown in Figure 4 were obtained. .

In addition, the test panel had a discharge gap length d of 80 to 120μ,
Neon (Ne) + xenon (used as filler gas)
The Xe concentration of
-α (I'm getting used to it.

Further, the pulse width of the shift pulse Ps applied to the shift electrode of the panel is selected to be 9 μS.

As is clear from FIG. 4, the write voltage Vw in the region where the shift voltage Vs is low changes significantly depending on the pulse width τW of the write pulse Pw.

That is, in the conventional case where τw = 9 μs, the minimum write voltage Vw11li1l is about 143V, but the optimal τ
When w=3 μs, V wml! l= 1 2 3
Therefore, the write margin corresponding to the difference from the maximum write voltage Vwmax increases.

As the write margin increases, the minimum shift voltage VsmVL also decreases by about 4 V at the lower left of the margin characteristic diagram, so the shift margin also increases.

From this point of view, τw=3 to 4.5 μS is suitable.

Note that when the pulse width τW of the write pulse Pw is set to 3 μS or less, the discharge probability decreases in relation to the discharge formation delay time, and the margin tends to decrease.

Note that when the pulse width τW of the write pulse Pw is made smaller than the pulse width τS of the shift pulse Ps, the minimum write voltage Vw771m becomes somewhat larger in the rightward upward direction at the intermediate level or higher of the shift voltage range compared to the conventional case. Become.

FIG. 5 shows the write voltage pulse of an embodiment for further lowering the minimum write voltage Vwmvt in the region above the intermediate level. This shows the waveform of

In other words, in the case of the figure, the pulse width of the first cycle pulse in the write pulse train in the write step is set to be larger than the pulse width of the shift pulse, and its falling edge is applied to the write electrode following the write panorez train. The voltage level of the remaining write pulses is made equal to that of the wide pulse, and the pulse width is made the narrow write pulse.

As is well known, by using a large pulse, a discharge spot can be generated at a discharge point with a low voltage level. Therefore, by applying the write pulse train to the write electrode, the minimum write voltage V wmVl can be set as shown in FIG. It can be significantly lower than the corresponding voltage value.

As a result, the write margin can also be significantly increased.

The reason why the fall of the large write pulse is made to coincide with the rise of the next shift pulse is to prevent the discharge once generated at the write discharge point from self-erasing at the fall of the pulse.

FIG. 6 uses the same test panel as described in FIG.
The write voltage-shift voltage characteristics are shown in μs.

As can be seen from the figure, the minimum write voltage V wml! l
is significantly lower than in FIG. 4 over the entire range of shift voltage levels.

That is, for example, when the shift voltage Vs = 73V, the minimum write voltage V W77X is about 114V, which is about 8V lower than that of about 122V in Fig. 4, and the write margin increases by this decrease. It turns out.

FIG. 7 shows an example configuration of a write drive circuit for generating write pulses Pw shown in FIGS. 3 and 5 for the write electrodes, in which write pulses are selectively supplied to seven write electrodes. It is shown as being done.

In this figure, Q1 is a power supply control transistor, Q2
~Q8 is a selection transistor, D1 ~ D8 are diodes, R1 ~ R1 are resistors, C1 is a capacitor, ■1
~■8 is an inverter, Vcc is an operating power supply, and Vw is a write power supply.

Further, a write timing signal (logical value XX1") is applied to the input terminal inl, a signal representing information (logical value XX1") is applied to the input terminals In2 to 1n8, and the above-mentioned signal is applied to the output terminals outl to out7. A write electrode (not shown) is connected.

For example, at time t1, a timing signal is input to input terminal 1n1, and input terminal 1n2 + ln4 H ln
7 are applied with information signals, transistor Q1 is turned on, transistors Q2 and Q4 -
Q7 is off and transistors Q3, Q5, Q6,
Since Q8 is turned on, the output terminals Ou i1 and Ou
*3 The write voltage Vw is applied to the write electrode connected to yOut6, that is, the write pulse rises.

During this time, the remaining write electrodes are grounded by their corresponding transistors.

When the generation of the write timing signal is stopped at the next time t2, the transistor Q is turned off, so that the supply of the write voltage is stopped.

At this time, since there is no information signal, all transistors Q2 to Q8 are turned on, and the write electrode is grounded, that is, the write pulse falls.

Thus, a write pulse having a predetermined pulse width is generated depending on the output time of the timing signal.

Although preferred embodiments of the present invention have been described above, the essence of the present invention is not limited to these embodiments, but can be modified in various ways, and the modified examples are listed below.

1) The information writing step does not need to be performed in four cycles; it may be less than or more than four cycles.

2) It is not necessary to make all the pulses of the write pulse train in the write step narrow pulses, and only the final cycle pulse in the pulse train may be made narrow pulses.

3) A narrow write pulse following a large write pulse may be clamped to the shift voltage level and replaced by a narrow or regular shift pulse.

4) The generation time of the narrow write pulse does not need to be synchronized with the generation time of the shift pulse applied to the shift discharge point adjacent to the write discharge point, and can be provided before or after the shift pulse generation time. .

As is clear from the above explanation, according to the write method of the present invention, at least the last pulse in the write pulse train applied to the write discharge point has a pulse width smaller than the pulse width of the shift pulse. When a discharge spot is generated at a write discharge point, the discharge spot can be easily shifted to an adjacent shift discharge point, so that the minimum voltage level of the write pulse can be lowered and the write margin can be significantly increased. be able to.

At the same time, as mentioned above, the shift margin can also be significantly increased.

Further, the drive circuit can be easily integrated into an integrated circuit.

Sixth, since the pulse width of the write pulse is small, the current consumption of the write power supply can be made smaller than in the past.

Therefore, if this invention is applied to a double-spot type self-shifting gas discharge panel, the effects will be extremely effective.

[Brief explanation of the drawing]

FIG. 1 shows an example waveform of a conventional write pulse train and shift pulse train applied during the information writing step, FIG. 2 shows a curve diagram for explaining the conventional write margin and shift margin, and FIG. 3 shows a write pulse train according to the present invention. and shift pulse train 1
Example waveforms, FIG. 4 is an explanatory diagram of the effect of the write pulse train in FIG. 3, FIG. 5 is a write pulse train waveform according to another embodiment of the present invention, and FIG. FIG. 7 is a schematic diagram of an example of a drive circuit for generating write pulses according to the present invention. Pw: write pulse, ■w: write voltage, Ps: shift pulse, ■s: shift voltage, τW and τ'w: pulse width of write pulse, τS: pulse width of shift pulse.

Claims (1)

[Claims] 1 includes a periodic arrangement of a plurality of groups of shift discharge cells defined by regularly arranged electrodes, and a write discharge cell defined by a write electrode provided adjacent to one end of the discharge cell array, and which stores input information. In the writing step, a write pulse train for generating a discharge spot in the write discharge cell is applied at a predetermined cycle according to the information, and the discharge spot generated by this write pulse train is transferred to a shift discharge adjacent to the write cell. A writing method for a cell-shifting gas discharge panel in which a cell is shifted to a cell, wherein a pulse width of at least a final period of a write pulse of a write pulse train applied to the write electrode during the information writing step is applied to the shift electrode. A writing method for a self-shifting gas discharge panel characterized in that the pulse width of the shift pulse is made smaller than the pulse width of the shift pulse.