JPH06186928A - Method for driving dc gas discharge light emission device - Google Patents

Abstract

PURPOSE:To provide a method for driving a DC gas discharge light emission device capable of stably performing the discharge generation and the discharge maintaining operation also compared with conventional manner and attaining the long life, the improvement of display quality, the reduction of power consumption and the driving with low voltage of a light emission device. CONSTITUTION:The discharge is generated by line-sequentially impressing first driving pulses Vw and Vsc on a cell for discharge light emission made a write object among the cell group for discharge light emission belonging to scanning signal lines Y1-Yk by (k) lines scannable within the time Tb when a priming effect in the cell for discharge light emission is continued in a par of the time Tw in the time Tb. The discharge maintaining operation is performed by simultaneously impressing the second driving pulses VSUS and Vk on all cells of the cell group for discharge emission in the remaining time TSUS within the time Tb. The second driving pulses are impressed on all cells on the scanning signal lines Yl-Yk as well when the second driving pulses are impressed in the processing of the cells on the scanning signal lines by (k) lines from Yk+l.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for driving a direct current type gas discharge light emitting device (hereinafter, also referred to as "DC-PDP" or "light emitting device").

[0002]

2. Description of the Related Art A DC-PDP, as shown in FIG.
Many data signal lines X _i (i = 1, 2, ..., M)
And a large number of scanning signal lines Y _j (j = 1, 2, ..., N)
And m × n discharge-emission cells A (i, j) which are respectively formed at the intersections of these signal lines. In FIG. 2, 11 is the light emitting device, 13 is a data signal line drive circuit, and 15 is a scanning signal line drive circuit. An example of such a DC-PDP is, for example, Document I (Technical Research Report EID92 of the Institute of Electronics, Information and Communication Engineers).
-8 (1992.8), pp. 41-48).

In the DC-PDP, the discharge voltage-current characteristic shows a hysteresis characteristic. FIG. 3 is a diagram for explaining this characteristic. When the voltage applied between the scanning signal line and the data signal line is gradually increased, a discharge light-emission cell (hereinafter, may be abbreviated as “cell”) is discharged at a certain voltage V _S to generate a current. Flows (see the path (a) in FIG. 3), and after the discharge occurs, the discharge is maintained up to the voltage V ₀ and the discharge is not stopped even if the voltage applied between both signal lines is V _S or less. (See path (b) in FIG. 3). Here, the voltage V _S is referred to as a discharge start voltage V _S, and the voltage V ₀ is referred to as a discharge sustaining voltage V ₀ .

In order to put the DC-PDP into practical use, it is important to improve brightness and reduce power consumption. In order to improve these, a driving method, that is, a memory driving method utilizing the above-mentioned hysteresis characteristic has been developed (for example, the above-mentioned document I). FIG. 4 is a drive signal waveform diagram (time chart) for explaining the conventional memory drive method. However,
The time indicated by T in FIG. 4 is the sequential scanning cycle of the scanning signal line Y _j (time during which one scanning signal line is in the selected state), and the portion indicated by 21 (hatched portion) is high. The part which becomes an impedance state is shown.

In this conventional driving method, when discharge light emission is generated in the discharge light emission cell A (i, j), the discharge start voltage V _{S is} applied between the data signal line X _i and the scan signal line Y _j.
The above-mentioned first drive pulse is applied. Specifically, as shown in FIG. 4, the write pulse V _W is applied to the data signal line X _i and the scan pulse V _SC is applied to the scan signal line Y _j , so that V _W −V V is applied between the signal lines. _A first drive pulse of _SC ≧ V _S is applied. Further, in order to maintain the discharge generated in this way, within the time after the discharge emission is performed and until the charged particles, ions, etc. generated by the discharge emission disappear (the time when the plumbing effect lasts). Data signal line X _i and scan signal line Y _j
In the meantime, the second drive pulse having the discharge sustaining voltage V ₀ or higher is applied. Specifically, as shown in FIG. 4, the sustain pulse V _SUS is applied to the data signal line X _i and the sustain bias voltage V _k is applied to the scan signal line Y _j , so that V _SUS is applied between the signal lines. The second drive pulse satisfying −V _k ≧ V ₀ is applied. Then, the scanning signal line Y _j is sequentially scanned from j = 1 to n, and the data signal line X is synchronized with this.
Write pulse V _W and sustain pulse V for _i (i = 1 to m)
By applying _SUS , any of the m × n discharge light emitting cells can be discharged and emitted, and the discharge sustaining operation can be performed. Further, when the discharge sustaining operation is stopped, that is, the discharge light emission is stopped, the second drive pulse is not applied between the data signal line X _i and the scanning signal line Y _j . Specifically, as shown in FIG. 4, after a predetermined discharge sustaining time T × P (where P is an arbitrary integer) has elapsed, V _E (the ground potential of the scanning signal line) is sequentially applied to the scanning signal line Y _j. It can be said that V _E > V _k ) is applied. It should be noted that this P is determined by the gradation of an image or the like when the light emitting device is used as a display device for a television, for example.

In order to carry out the driving method as described above, the data signal line driving circuit 13 (see FIG. 2) is connected to the data signal line X _i .
Drive pulse in which the write pulse V _w and the sustain pulse V _SUS are superimposed, and the scanning signal line is
The scanning signal line driving circuit 15 applies a driving pulse in which the scanning pulse V _SC , the sustain bias voltage V _k, and the (erasing pulse V _E ) are superimposed. The pulse widths of the write pulse V _W and the sustain pulse V _SUS are set to arbitrary optimal times, but in general, each of the sequential scanning cycle T of the scanning signal line Y _j is about 4 minutes. 1 time (T
/ 4). For example, when T = 4 μsec, the pulse width of each of V _W and V _SUS is 1 μsec. It is empirically understood that if these pulse widths are made longer than T / 4, the priming effect becomes too large and erroneous light emission easily occurs in the non-written cells.

[0007]

However, in the conventional memory driving method, the following problems are inherent.

(1) The width of the first drive pulse for discharge light emission (the pulse width defined by the write pulse V _w and the scan pulse V _SC in the above example) is set to prevent erroneous light emission in non-write cells. Therefore, if it is too short, the discharge start voltage V _S
Therefore, it becomes necessary to increase the discharge voltage to secure the discharge, and this increase in the drive voltage leads to an increase in the discharge current, resulting in an increase in power consumption.

(2) If the second drive pulse width for sustaining the discharge (the pulse width of the sustain pulse V _{SUS in} the above example) is too short, the discharge sustaining operation cannot be performed, or even if it is possible, the discharge sustaining operation is not performed. The brightness of the cell decreases.

(3) Since each data signal line and scanning signal line has a capacitance component, when the drive pulse is turned on / off, reactive power is generated for charging and discharging the capacitance component. In the conventional driving method, the sustain pulse V _SUS needs to be applied once to the data signal line X _i every time the scanning signal line Y _j is scanned. Since the V _SUS pulse is applied to the signal line at least n times, this causes an increase in reactive power, particularly an increase in power consumption in the data signal line drive circuit.

(4) Since the pulse width of each pulse of V _W and V _SUS is restricted as described above, the drive circuit for supplying these pulses has a high slew rate (rise,
Pulse supply capability with a fast fall time is required.
For this reason, these drive circuits are naturally complicated, resulting in an increase in power consumption and cost of the drive circuits.

(5) When the drive circuit is integrated (made into an IC), since the target is the circuit as described in (4) above, it is difficult to perform, for example, designing and heat generation countermeasures.
It is difficult to convert to C.

(6) Since each data signal line and scanning signal line has a coil component (L component) and a capacitance component (C component), the waveform of the drive pulse is easily distorted due to reflection and resonance. With the conventional driving method, the pulse width cannot be increased so much that the waveform distortion of the pulse easily occurs. For this reason,
An abnormal voltage is likely to be applied to a specific cell in the light emitting device, and as a result, the life of the light emitting device and the display quality are degraded. This becomes more obvious as the size of the light emitting device increases.

(7) When the reflection or resonance as described in (6) above occurs, the variation in the discharge start voltage for each cell tends to increase. In addition, when the pulse width of the V _W or V _SUS pulse is short, the variation in the discharge start voltage for each cell is likely to be large. Therefore, the operation margin of the drive voltage cannot be secured, and it becomes difficult to stably operate the light emitting device.

The present invention has been made in view of the above points, and an object of the present invention is to provide a driving method of a direct current type gas discharge light emitting device which can solve the above problems.

[0016]

In order to achieve this object, according to the present invention, a large number of data signal lines, a large number of scanning signal lines, and discharge light emitting cells respectively formed at intersections of these signal lines are provided. A discharge gas emission is generated by applying a first drive pulse through the above-mentioned both signal lines to a discharge light emission cell to be written in the DC type gas discharge light emission device having the above, and a second drive pulse is applied. In the driving method of the DC type gas discharge light emitting device in which the discharge sustaining operation is performed and the discharge is stopped by stopping the application of the second driving pulse described above, the priming effect in the discharge light emitting cell is improved. Among the discharge light emitting cell groups belonging to the plurality of scan signal lines that can be scanned within the sustainable time, the discharge drive light emitting cells to be written to have the first drive for a part of the aforementioned time. Pulse line sequentially applied, in the remaining time in the above-mentioned time, characterized by simultaneously applying a second driving pulse to all the discharge light emission cells of a discharge light emitting cell group described above.

In implementing the present invention, when the above-mentioned first and second drive pulses are sequentially applied to the remaining discharge light-emitting cells of the light-emitting device using the above-mentioned plurality of scanning signal lines as a processing unit, At the time of simultaneously applying the second drive pulse to each discharge light emitting cell of the discharge light emitting cell group belonging to the new plurality of scanning signal lines, at least the discharge light emitting cell group processed so far It is preferable to simultaneously apply the second drive pulse to each discharge light emitting cell of the discharge light emitting cell group that continues the discharge maintaining operation.

[0018]

According to the structure of the present invention, after the discharge light emission is generated in the discharge light emission cells belonging to the predetermined plural scanning signal lines, all the cells belonging to the plural scanning signal lines are generated. Since the sustaining pulses are applied in parallel, there is a margin in the pulse application time as compared with the conventional method in which the sustaining pulses are applied in synchronization with the sequential scanning cycle of each scanning line (details of the embodiment described later. (See Section 2). Therefore, it is possible to extend the pulse widths of the write pulse and the sustaining pulse as compared with the conventional one, and to reduce the rising and falling times of these pulses as compared with the conventional one. Further, the number of times of applying the second drive pulse for sustaining the discharge can be reduced as compared with the conventional case (for details, refer to the second item of the embodiment described later).

Further, when the second drive pulse is simultaneously applied to the respective discharge light emitting cells of the discharge light emitting cell group belonging to the new plurality of scanning signal lines, the discharge light emitting cell group processed so far. In the configuration in which the second drive pulse is simultaneously applied to each of the discharge light emitting cells of the discharge light emitting cell group that continues the discharge sustaining operation among the above, the discharge sustaining of the cells is performed by the above-described processing. It is also possible to maintain the discharge of cells that require

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for driving a direct current type gas discharge light emitting device according to the present invention will be described below with reference to the drawings. In this embodiment, the driven DC type gas discharge light emitting device is the DC-PDP 11 described with reference to FIG.

1. Description of Driving Method of Embodiment FIG. 1 is a drive signal waveform diagram (time chart) used for describing an embodiment of the driving method of the present invention. Specifically, D
Plurality of discharge light emitting cell A (i, j) arranged in a matrix included in the C-PDP 11 shows the case where the discharge is stopped after sequentially discharge light emission and discharge sustain operation in the time of the T _b × Q It is a time chart. However,
FIG. 1 schematically shows pulse timings and the like so that the present invention can be understood. In addition, in FIG.
T _b is a predetermined time determined within a time period during which the priming effect in the discharge light emitting cell A (X _i , Y ₁ ) can be maintained, and Q is an arbitrary integer. It should be noted that this T _b may be determined by, for example, an experiment according to the design of the light emitting device. When the light emitting device is used as, for example, a television display device, Q is determined by the gradation of the image or the like.

In the driving method of this embodiment, the time T _b
A plurality of scanning signal lines that can be scanned in the inside, Y _{1 in the} illustrated example
Discharge light emission cells to be written in the discharge light emission cell group belonging to k scanning signal lines of Y _k (k = 4 in the example of FIG. 1), this discharge in the illustrated example All cells (X _i , Y ₁ ) of the light emitting cell group, (X _i ,
Y ₂ ), ..., (X _i , Y _k ) with respect to the time T _b
At part of the time T _w , the first drive pulse for generating discharge is line-sequentially applied to cause discharge in each cell. The first drive pulse in this embodiment is the write pulse V _W applied to the data signal line X ₁ and the scan signal line Y _j.
And a scanning pulse V _SC applied to. And
Cells The first driving pulse in the T _W Time (X _i,
Y ₁ ), (X _i , Y ₂ ), ..., (X _i , Y _k ) are sequentially applied to cause discharge in each cell.

Further, in the driving method of this embodiment, during the remaining time T _SUS within the time T _b , all discharge light emission cells (X _i , Y ₁ ) of the discharge light emission cell group (X _i ,
A _second drive pulse for maintaining discharge is simultaneously applied to Y ₂ ), ..., (X _i , Y _k ). The discharge of the cell which has started to be discharged within the time T _W is maintained by this second drive pulse. The second drive pulse in this embodiment is
It is composed of a sustain pulse V _SUS applied to the data signal line X _i and a sustain bias voltage V _k applied to the scan signal line Y _j .

In the driving method of the present invention, Y _{k + 1}
For the discharge generation and discharge sustaining of the write pair cells of the discharge light emission cells belonging to the subsequent scan signal lines, the discharge light emission cell group belonging to the k scan signal lines is set as a processing unit and the above Y ₁ The same method as in the case of cells belonging to the scanning signal lines of ~ Y _k is used. However, when applying the second drive pulse which is the sustaining pulse to all the cells of the discharge light emitting cell group belonging to the _k scan signal lines of the scan signal lines Y _{k + 1 to} Y _{K + k} , The second drive pulse is simultaneously applied to at least each discharge light emitting cell of the discharge light emitting cell group that continues the discharge sustaining operation of the processed discharge light emitting cell group. In the example of FIG. 1, the scanning signal line Y
_When a second drive pulse which is a sustaining pulse is applied to all the cells of the discharge light emitting cell group belonging to the k scanning signal lines of _{k + 1 to} Y _{K + k} (at the timing of the region R in FIG. 1). ), The second driving pulse is simultaneously applied to all cells of the discharge light emitting cell group belonging to the k scanning signal lines of the scanning signal lines Y _{1 to} Y _K. By doing so, it is possible to maintain the discharge (in units of k scanning signal lines) of the cells that need to be maintained in the discharge by the above processing.

When the discharge is stopped, the supply of the second drive pulse may be stopped. Specifically, as shown in FIG. 1, after a predetermined discharge sustaining time (T _b × Q) has elapsed, the sustain bias V _K is not sequentially applied to the scanning signal line Y _j in units of k signal lines. (The potential of the scanning signal line is, for example, a potential V _E (V
_The discharge is stopped by setting _E > V _k ).

2. Description of Difference between Embodiment and Conventional Method A difference between the conventional memory driving method described with reference to FIG. 4 and the driving method of the above-described embodiment will be described.

Assuming that the time for selecting one scanning signal is T, this T and a predetermined time T _b determined within a time period during which the priming effect described in the above embodiment can be maintained have a relationship of T _b = kT. become.

Here, k = 4 and T = 4 μsec.
And

Then, in the driving method of the embodiment, T _b = k
Since T = 4 × 4 = 16 μsec, and since the sustaining pulse V _SUS is simultaneously applied to the k scanning signal lines, for example, the pulse width of the sustaining pulse V _SUS is T _b / 4 = 4 μm.
Even if it is set to sec, the time that can be used for writing the k scanning signal lines into each cell is (16-4) = 12.
Therefore, the maximum time that can be used for writing one scanning signal line into a cell can be 12/4 = 3 μsec. In the conventional driving method described with reference to FIG. 4, T =
If the pulse width is 4 μsec, the pulse widths of the write pulse V _W and the sustaining pulse V _SUS within the time T are 1 μsec, respectively. Compared with the driving method of the present invention, the write pulse W _W and the sustaining pulse are V _sus
It can be understood that each pulse width of can be widened as compared with the conventional one.

Further, in the conventional driving method described with reference to FIG. 4, the time T is set between the data signal line X _i and the scanning signal line Y _j.
The second drive pulse (V _SUS and V
_k ) has to be applied and therefore the second drive pulse has to be applied four times within the time period of 4T. On the other hand, in the driving method of this embodiment, the second driving pulse need only be applied once within the time period of 4T. From this, it is understood that the driving method of the present invention can reduce the number of times the pulse is applied to the light emitting device as compared with the conventional case.

In the above-mentioned embodiment, an example in which k is set to 4 has been described, but k may be an appropriate number of 2 or more in consideration of T and T _b . Even in that case, it is obvious that the same effect as the embodiment can be obtained.

[0032]

As is apparent from the above description, according to the driving method of the DC type gas discharge light emitting device of the present invention,
A discharge light emitting cell group belonging to a predetermined plurality of scanning signal lines is used as a processing unit, and a writing operation is first performed on these cells, and then a discharge sustaining operation is simultaneously performed on all the cells. Therefore, as compared with the conventional method in which the sustaining pulse is applied in synchronization with the sequential scanning cycle of each scanning line, there is a margin in the pulse application time, so the pulse width of the write pulse and the sustaining pulse should be extended. , And the rise and fall times of these pulses can be relaxed. Further, the number of times of applying the second drive pulse for sustaining the discharge can be reduced as compared with the conventional case. Therefore, the following effects can be expected.

(1) Since the first drive pulse width for generating the discharge can be widened as compared with the conventional one, the discharge starting voltage and the current can be reduced as compared with the conventional one, and the low voltage and the low current of the drive circuit and the conventional one can be reduced. It is possible to reduce power consumption.

(2) Since the second drive pulse width for sustaining the discharge can be made wider than before, the discharge sustaining operation can be made more stable than before, and the brightness in sustaining the discharge can be improved.

(3) Since the number of drive pulses applied can be reduced as compared with the conventional case, the reactive power in the signal line of the light emitting device can be reduced as compared with the conventional case, so that the power consumption of the drive circuit can be reduced.

(4) Since the pulse width can be widened, a drive circuit having a high slew rate is not required, so that the power consumption and cost of the drive circuit can be reduced.

(5) Since the drive circuit can be simple and has low power consumption, the drive circuit can be easily integrated into an IC.

(6) Since the drive pulse width can be widened, the rise time and the fall time of the drive pulse can be relaxed, so that the distortion of the waveform of the drive pulse due to reflection or resonance can be made less likely to occur than before. For this reason, it is possible to prevent an abnormal voltage from being applied to the cell,
The life of the light emitting device can be extended and the display quality can be improved.

(7) Since the drive pulse width can be widened, the operation margin relating to the drive voltage of the light emitting device is widened, so that the operation of the light emitting device can be stabilized.

[Brief description of drawings]

FIG. 1 is a time chart used for explaining a driving method according to an embodiment.

FIG. 2 is a diagram for explaining the configuration of a DC gas discharge light emitting device.

FIG. 3 is an explanatory diagram of discharge characteristics of a DC gas discharge light emitting device.

FIG. 4 is a time chart used for explaining a conventional driving method.

[Explanation of symbols]

11: Light emitting device 13: Data signal line drive circuit 15: Scan signal line drive circuit Xi: Data signal line Y _j : Scan signal line A (i, j): Discharge light emitting cell

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Terauchi 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd.

Claims (2)

[Claims] 1. A discharge light emission cell to be written in a direct current gas discharge light emitting device comprising a large number of data signal lines, a large number of scan signal lines, and discharge light emission cells respectively formed at the intersections of these signal lines. , Applying discharge of the first drive pulse through both of the signal lines causes discharge light emission,
In the driving method of the DC type gas discharge light emitting device, the discharge sustaining operation is performed by applying the driving pulse and the discharge is stopped by stopping the application of the second driving pulse. Of the discharge light emission cells targeted for writing of the discharge light emission cell groups belonging to the plurality of scanning signal lines that can be scanned within a time period during which the priming effect of A direct-current gas, wherein the first drive pulse is applied line-sequentially, and the second drive pulse is simultaneously applied to all discharge light-emission cells of the discharge light-emission cell group in the remaining time within the time period. Driving method for discharge light emitting device. 2. The method of driving a gas discharge light emitting device according to claim 1, wherein the plurality of scanning signal lines are used as a processing unit for the remaining discharge light emitting cells of the light emitting device. When the drive pulses are applied one after another, the processing so far is performed when simultaneously applying the second drive pulse to each discharge light emitting cell of the discharge light emitting cell group belonging to the new plurality of scanning signal lines. A direct current type gas discharge light emitting device characterized in that the second drive pulse is simultaneously applied to each discharge light emitting cell of at least the discharge light emitting cell group of the discharge light emitting cell group which continues the discharge maintaining operation. Driving method.