JPH01130194A - Plasma display device - Google Patents

Abstract

PURPOSE: To improve luminance by impressing reverse phase or inphase pulselike voltage to data side electrodes in accordance with the existence/non-existence of a display in synchronism with 1st pulselike voltage impressed to two adjacent scanning electrodes and impressing DC voltage to the data side electrodes in a period for impressing 2nd pulselike voltage to the scanning electrodes. CONSTITUTION: A period (a) for impressing the 1st pulselike voltage to data side electrodes in accordance with the existence of a display in two scanning periods H, H selecting two adjacent scanning electrodes, a period (b) for impressing the 2nd pulselike voltage and a period (c) for impressing DC voltage are prepared. Reverse phase or in-phase pulselike voltage corresponding to the existence/non-existence of a display is impressed to scanning electrodes in the periods (a), (c) in synchronism with the 1st pulselike voltage and the DC voltage is impressed in the period (b). Consequently luminance can be improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a plasma display device, and in particular,
This invention relates to an AC refresh type plasma display (FDP) device.

[Conventional technology]

Conventionally, in this type of AC refresh type plasma display (FDP) device, the voltage waveform applied to either one of the insulator and the external electrode group facing each other through the discharge space is The voltage waveform is divided into divided pulses, and when the voltage waveform applied to the one electrode group is turned on, a pulse voltage of the opposite phase is applied to the other electrode group, and when the voltage waveform is not turned on, a pulse voltage of the same phase is applied to the other electrode group. It was discovered in the 1970s that it demonstrated stable operation by applying voltage.
No. 5-48318.

[Problem that the invention seeks to solve]

In the conventional device described above, pulse voltages of opposite phase and the same phase are applied to each electrode of the electrode group formed on the same insulator in response to lighting and non-lighting, so electrically , the drive circuits are coupled through the stray capacitance between the respective electrodes, and when lighting and non-lighting states occur between adjacent electrodes, the power consumption of the drive circuits of the adjacent electrodes becomes maximum. Furthermore, the brightness of an AC refresh FDP is determined by the number of pulses included in a unit time, but as the number of pulses increases, the power consumption of the drive circuit increases, so the drive frequency is limited and it is difficult to obtain sufficient brightness. The drawback was that it was difficult to do so.

On the other hand, if a time lag occurs between the high-frequency pulses applied to the scanning electrode group and the data electrode group,
This method exhibited a different operation from that disclosed in No. 18, and had the disadvantage that the driving voltage range of the device was narrowed.

Furthermore, when a transparent electrode is used as the data side electrode, a distributed constant circuit is formed by the stray capacitance between this transparent electrode and the electrode, and the output of the drive circuit and the waveform at the tip of the transparent electrode are , and because the voltages are different, there is a drawback that uneven brightness occurs.

[Means for solving problems]

The present invention eliminates the drawbacks of the phase selection drive of the conventional AC refresh type plasma display described above, and provides a plasma display device that has high brightness, low power consumption, and a wide operating range.

In other words, depending on whether the display is displayed or not, the period during which a waveform voltage having the opposite phase or the same phase as the waveform of the voltage applied to the scanning electrode is applied to the data-side electrode and the voltage applied to the scanning electrode are determined as in the conventional phase selection method. The scanning period includes a period in which a voltage completely unrelated to the waveform is applied to the scanning electrode, and the power consumed during the period in which the voltage is applied is the same as in the conventional phase selection method. However, the power consumed during the period when a voltage completely unrelated to the waveform of the voltage applied to the scanning electrode, that is, a DC voltage, is applied to the data side electrode is the power consumed between the data side electrodes. The amount of power consumed becomes negligible, so it is significantly reduced.

Furthermore, by lowering the drive frequency during the period when the same drive as the phase select method is performed and increasing the frequency during the period when DC voltage is applied to the data side electrode, it is possible to stabilize the drive and further reduce power consumption. Can be done. Furthermore, as will be described later, the period in which each scan electrode is selected is set as two scan periods, so that the display period becomes longer and the brightness can be increased. The driving method of the AC refresh type plasma display of the present invention is that an electrode group is formed on a glass plate, and the electrode group connects two glass plates covered with a dielectric material, with the dielectric material facing each other and maintaining an appropriate distance. place,
When driving a plasma display panel by applying a pulsed voltage between the electrodes, the periphery of which is hermetically sealed with a glass frit and neon gas sealed inside, a pulsed voltage is applied only to the negative electrode. When applying voltage and keeping the other electrode at O potential to cause a discharge between the electrodes, one discharge cell in the plasma display panel
The discharge voltage is the minimum vehicle power discharge starting voltage (VDmin)
, if the voltage at which all cells of the plasma display panel discharge is defined as the maximum discharge starting voltage (VDmax), a pulsed voltage (vo) higher than VDmin and lower than VDmax is applied to one electrode of the plasma display.
is applied, and a pulsed voltage (vl) with the opposite phase and the same phase as that is applied to the other electrode, VDmin>IVO
When the conditions of I IVII are met, the discharge stops and VD
This is an improved device that is characterized by being driven by starting discharge when the condition max < l Vol + l V+ l is satisfied.

When a pulsed voltage higher than the maximum discharge starting voltage is applied to one electrode and a DC voltage is applied to the other electrode, all cells in the panel start discharging, but the voltage is not applied. It takes time for the discharge to start, and although it varies depending on the applied voltage, the discharge delay time in the AC refresh method is generally 5 microseconds or more. On the other hand, the discharge response after discharge is started is very fast, taking less than 100 nanoseconds.

The AC refresh type plasma display device of the present invention utilizes this discharge delay phenomenon, and applies a pulsed voltage higher than the gravitational discharge starting voltage to one electrode, and as in the conventional phase selection method, depending on the presence or absence of display, , apply a pulsed voltage of the same phase and opposite phase to the other electrode, create a state in advance so that the discharge cells that should be discharged are discharged, and the discharge cells that are not to be discharged are not discharged, and then the pulsed voltage of the other electrode is removed. Then, by applying a pulsed voltage to only one electrode, that state is maintained, and before the non-lit cells are lit by the pulsed voltage to one electrode, the state is returned to the same state as in the conventional phase selection method. This device is characterized in that the FDP is driven by repeating the following steps.

That is, if the state in which the device is driven by the conventional phase selection method is defined as the address mode, and the state in which the address mode is maintained by applying a pulsed voltage to one electrode as the hold mode, then the device of the present invention can perform the address mode. It is characterized by alternating repetition of mode and hold mode. Furthermore, the present invention is characterized in that by simultaneously selecting two adjacent scan electrodes, two scan periods are created, each of which is a period during which each scan electrode is selected, thereby doubling the display period. When one scan electrode is in address mode, a DC voltage is applied to the other scan electrode,
Therefore, the address mode is not set, and the display is driven so that the previous display state is maintained.

〔Example〕

Next, a detailed description will be given with reference to the drawings.

FIG. 1 is a timing chart of voltage arrangement according to the first embodiment of the present invention.

FIG. 2 is a timing chart for explaining the timing of pulsed voltages applied to the scanning electrodes.

The plasma display panel used in the device of the present invention has two glass plates each having a group of electrodes covered with a dielectric material.
The electrode groups are designed to face each other, intersect perpendicularly, and the intersection becomes a light emitting point for display. In order to drive the plasma display panel, 2- in FIG.
With respect to the period H of the horizontal synchronizing signal shown in D, the scanning electrodes in the first row are selected for a period of 2H as shown in 2-A.

Next, as shown in 2-B, after IH, the horizontal electrodes in the second row are selected for a period of 2H, and this is repeated for each IH, and the scanning electrodes in the first row are selected again by the vertical synchronization signal in 2-C. be done. A desired display is obtained on the plasma display panel by applying a data signal to the data side electrode in correspondence with the scanning of the scanning electrode.

1-A shows the pulsed voltage applied to the scanning electrodes in the first row, and 1-C and 1-D show the pulsed voltages applied to the data-side electrodes in the m-th and n-th columns, respectively. It is something that 1-E and 1-G are discharge light emitting point cells (1st row, 1mth column) formed at the intersections of the scanning electrode in the 1st row and the data-side electrodes in the m-th column and the n-th column, respectively; Column n) shows the voltage waveform applied to the cell. Since the voltage waveform applied to the data-side electrode of the m-th column is in opposite phase to the voltage waveform applied to the scan electrode of the first row, the cell in (1st row, m column) is in the lighting mode. On the other hand, since the pulsed voltage applied to the n-column electrode is in phase with the pulsed voltage applied to the first row electrode (1st row, nth column), the cell is in a non-lighting mode, that is, a light-off mode. .

(1st row, 1m column) The pulsed voltage applied to the cell is the first
It is expressed by the potential difference between the pulsed voltages applied to the scanning electrode of the row and the data-side electrode of the m-th column, and has the waveform 1-E in FIG.

(1st row, nth column) When the pulsed voltage applied to the cell is similarly expressed in terms of potential difference, it becomes as shown in FIG. 1-G.

In the plasma display device according to the present invention, during the 2H period in which the scanning electrode is selected as shown in 1-A, the first pulse-like voltage is applied to the data side electrode according to the presence or absence of display during the C period. , a period b in which a second pulsed voltage is applied, and a period C in which a DC voltage is applied, while a display is displayed on the scanning electrode in periods a and C in synchronization with the first pulsed voltage. A pulsed voltage of opposite phase or the same phase is applied depending on the presence or absence of , and a DC voltage is applied during period b.

The operation in the C period during the 2H period is exactly the same as in Japanese Patent Publication No. 55-48318, and this period is defined as the address mode in the present invention. On the other hand, as shown in FIG.
This period is defined as hold mode.

First, the operation in the address state is as follows: VDmax< I V+ I + i Va I
”・(1) VDmin> l Vo l l
v+ l - (2) If the conditions (1) and (2) are satisfied, cells that should be lit are lit, and cells that should not be lit are turned off.

In the hold mode, as shown in the voltage waveform of period (a) in FIG. 1-E and 1-G, a pulsed voltage with an amplitude of (■.) is applied regardless of whether the light is on or off. The state created in the address mode applied prior to the hold mode is maintained during this period to perform display.

In other words, the cell in the 1st row and 2m column that is lit in the address mode discharges during period (a) and is filled with charged particles generated by the discharge, so the voltage is lower than that in the address mode. Even in the hold mode where the voltage is applied, the discharge starts easily.

On the other hand, in the cell (1st row, n column) that is not lit in the address mode, the voltage applied during the address mode period is lower than the discharge start voltage, and there are no charged particles in the cell (1st row, n column), and the discharge is C It takes a certain amount of time to start discharging at the voltage applied during period b without starting during period b, and if period b is selected appropriately, it is possible to determine the voltage at which discharge will not start in the hold mode. can.

Next, during the 2H selection period of the scanning electrodes in the first row,
The scan electrodes in the second row are selected at the same time.

When the scan electrodes of the second row are in the address mode, that is, during the C period of 1-A, no pulsed voltage is applied to the scan electrodes of the first row, but a DC voltage is applied, and the address mode is not established.

At this time, charged particles generated by the discharge in the previous b period remain in the lit cell portion of the first scan electrode, and in the hold mode of the next b period, the cells are discharged again to maintain lighting.

In addition, there are no charged particles in the unlit cell portion of the first scanning electrode,
The light-off state can be maintained by controlling the hold mode periods before and after the C period to within a certain period.

As described above, the PDP of the present invention has significantly improved brightness, power consumption, and operating voltage range.

Next, the FDP device according to the present invention will be described.

FIG. 5 shows a block diagram of the FDP device according to the present invention, which includes a plasma display 1, a driving circuit 2 for row electrode groups, a driving circuit 3 for driving column electrode groups, a latch 4 for storing data, and - It consists of a shift register 5 for storing data in the row electrodes and a shift register 6 for sequentially shifting the row electrodes.

The pulsed voltage applied to the row electrodes is generated by a combinational circuit at the final stage of the drive circuit 2, and has a peak value v0. The input signal of this circuit is a mixture of the output of the shift register 6 and a high frequency pulse 10 inputted from the outside using an AND gate.

The high-frequency pulse input from the outside and the output circuit of the final stage drive circuit are in opposite phase, but the frequency is the same, and by appropriately selecting this high-frequency pulse, it is possible to apply any pulsed voltage to the panel. It is.

The shift register 6 stores scan data 11. The scanning data 11 is input to the scanning clock 12, and is sequentially transferred using the scanning clock, and is sequentially sent to the AND gate of the driving section 2.

On the other hand, the column electrode drive circuit is also constituted by a fundamental circuit, and the output of the exclusive off circuit is inputted and inverted by the drive circuit.

The data input to the shift register 5 by the dot data input 17 and the data shift clock 18 is the latch pulse 1.
6, it is transferred to latch 4. Each latch output is input to an exclusive off circuit in the drive circuit 3, and mixed with a high frequency pulse 15 input from the outside. When there is no output from the latch 4, the output of the exclusive OR circuit is in opposite phase to the high frequency pulse 15 inputted from the outside, and the pulse voltage of the output circuit is in phase. On the other hand, when there is an output from the latch 4, the output of the exclusive off circuit is in phase with the high frequency pulse 15 input from the outside, and the pulse voltage of the output circuit is in reverse phase.

The C voltage required in the hold mode can be obtained by making the high frequency pulse 15 a direct current.

The frequency conversion required in the hold mode can be realized by switching the frequency of the high frequency pulse 1o input from the outside.

〔Effect of the invention〕

As explained above, the PDP of the present invention is pretentious.

Power consumption and operating voltage range have been significantly improved.

[Brief explanation of the drawing]

FIG. 1 shows applied voltage waveforms in an embodiment of the present invention. 1-A and 1-B show pulse voltages applied to the scanning electrodes of the first and second rows, respectively, and FIG. 1-C shows the m-th column data side electrodes, and FIG. 2-2 respectively show pulse-like waveforms applied to the n-th column data electrodes. Figure 1 1-E, 1-p, 1-G, 1-F are respectively
(-row, column 2m) (row 2, column 2m) (row 1, column n) (row 2,
(n column) shows the state of the voltage applied to the cell. FIG. 2 shows the pulsed voltage applied to the scanning electrodes. FIG. 3 shows a block diagram of the plasma display device of the present invention. Agent Patent Attorney Susumu Uchihara Figure 1 Figure 2 Now--2H-Ichiyu, 2/-/--◆ 1-H-+ Figure 3

Claims (1)

[Claims] 1. A voltage is sequentially applied to a group of scanning electrodes of a plasma display panel whose electrodes are coated with a dielectric material in a time-division manner every scanning period, and scanning is performed on each scanning electrode. In a plasma display that is driven by applying a voltage to the data-side electrode group according to the presence or absence of data in synchronization with the applied voltage, one scan electrode is selected for two adjacent scan periods. Two scan electrodes are selected at the same time, and during the two scan periods during which each scan electrode is selected, a first pulsed voltage,
A second pulsed voltage and a DC voltage are applied to each data side electrode, and the first pulsed voltage is synchronized with the first pulsed voltage during the period when the DC voltage is applied to the scanning electrode. The plasma is driven by means such that a pulsed voltage of opposite phase or the same phase is applied depending on the presence or absence of display, and a DC voltage is applied during a period when a second pulsed voltage is applied to the scanning electrode. display device. 2. The first voltage applied to the scanning electrode according to claim 1
The plasma display device is driven by increasing the frequency of the second pulsed voltage applied to the scanning electrode during a period when a DC voltage unrelated to the pulsed voltage is applied to the data side electrode.