JPH01130192A - Driving of plasma display device - Google Patents

Abstract

PURPOSE: To extend the range of driving voltage and to boost the voltage by impressing the same pulselike voltage as that of a nondata period in the initial partial period of an address state and setting up the frequency of pulselike voltage impressed to scanning electrodes in a hold state to a level higher than the frequency of an address state. CONSTITUTION: One scanning period H includes a period (a) for executing display in an address state and a period (b) for executing display in a hold state and the same pulselike voltage as that of a nondata period is impressed in the initial partial period (c) of the address state independently of the existence of data. The frequency of pulselike voltage impressed to scanning electrodes in the hold state is set up to a level higher than the frequency of the address state. Consequently the driving voltage can be extended at its range and boosted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for driving a plasma display, and particularly relates to a method for driving a plasma display (AC refresh type plasma display).
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[Conventional technology]

Conventionally, as a driving method for this type of AC refresh type plasma display (FDP), 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.
5-48318.

In addition, a pulsed voltage higher than the power discharge starting voltage is applied to one scanning electrode, and in-phase and opposite-phase pulses are applied to the other electrode depending on whether or not to display, similar to the conventional phase selection method (Japanese Patent Publication No. 55-48318). A voltage is applied to the discharge cells that should be discharged, and discharge cells that are not to be discharged are not discharged. Then, the pulse voltage of the other electrode is removed, and the pulse voltage is applied only to one electrode. This method reduces power consumption by sustaining that state with a pulsed voltage of one electrode, and returning to the state similar to the conventional phase selection method before turning on non-lit cells with a pulsed voltage of one electrode. A method has also been proposed.

[Problem that the invention seeks to solve]

In the conventional driving method 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. Electrically, the drive circuit is coupled through the stray capacitance between the respective electrodes, and the power consumption of the drive circuit is maximized when a lighting or non-lighting state occurs between adjacent electrodes. Furthermore, the brightness of A(l fresh FDP is determined by the number of pulses included in a unit time, but if the drive frequency is increased to increase the number of pulses, the power consumption of the drive circuit will increase. When a transparent electrode is used as the data side electrode, a distributed constant circuit is formed by the stray capacitance between the transparent electrode and the electrode, and the output of the drive circuit and the waveform at the tip of the transparent electrode, and voltage are different, there is a time lag and voltage change between the scanning side pulse voltage and the data side pulse voltage.
48318,
There was a drawback that the driving voltage range was narrow.

That is, the upper limit of the driving frequency is fixed, and there is also the drawback that it is difficult to obtain sufficient brightness.

[Differences between the invention and the prior art]

In contrast to the conventional driving method described above, the present invention includes a period in which display is performed in an address state and a period in which display is performed in a hold state during one scanning period, and furthermore, the address state is set during an initial part of the period. is a period in which the same pulse-like voltage is applied regardless of the presence or absence of data as when there is no data, and the frequency of the pulse-like voltage applied to the scan electrode in the hold state is at least higher than the frequency in the address state. It has original content.

[Means for solving problems]

The present invention provides a driving method that eliminates the drawbacks of the conventional AC refresh type plasma display driving method described above. In other words, one scanning period includes a period in which the display is performed in the address state and a period in which the display is performed in the hold state, and in addition, the address state includes a period in which the display is performed in the hold state. This is a period in which the same pulsed voltage as in the hold state is applied, and is characterized in that the frequency of the pulsed voltage applied to the scan electrode in the hold state is at least higher than the frequency in the address state.

〔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 driving method of the present invention consists of two glass plates each having electrode groups covered with a dielectric, the electrode groups facing each other, each electrode group intersecting at right angles, and the intersection point being the light emitting point for display. It is designed to be. To drive this plasma display panel, generally the horizontal synchronizing signal shown in FIG.
The first electrode is selected only for a period of time, and the peak value ■ is shown in 2-A in FIG. A pulsed voltage having a value of 0 is applied to the first electrode. In the case of a panel having m horizontal electrodes and n vertical electrodes, n vertical electrodes are selected and driven relative to the first horizontal electrode.

Next, after a certain period (blanking period), the second
The electrode is selected and, like the first electrode, V is applied for the H period.

A pulsed voltage having a peak value of is applied to the second electrode. (See Figure 2 2-B) The third electrode is pulsed to the second electrode. After the pulse-like voltage is applied, a pulse-like voltage is applied, and this operation is sequentially repeated thereafter for a period (V) until the vertical synchronizing signal is input. The state in which the first electrode can be selected is returned by the vertical synchronizing signal shown in FIG. 2 2-D.

That is, in the scanning method of this method, the horizontal synchronizing signal is used to scan sequentially, and after all the horizontal electrodes have been scanned, the original state is restored by the input vertical synchronizing signal. The vertical synchronization signal matches the refresh frequency of the display and is generally chosen to be 60 cycles or more. On the other hand, although the number of horizontal synchronization signals included in one period of the vertical synchronization signal matches the number of scan lines, generally the number of scan lines does not match the number of scan electrodes of the panel.
The number of scanning lines is greater than the number of scanning electrodes on the panel.

1-A in FIG. 1 shows a pulsed voltage applied to the first row electrode, and 1-B and 1-C in FIG. 1 indicate the m-th column and n-th column, respectively.
It shows the pulsed voltage applied to the column electrodes.

1-D and 1-E in FIG. 1 are the first row electrode and the mth row electrode, respectively.
A discharge light emitting point (
The voltage waveforms applied to the cell (row 1, column n) and the cell (row 1, column n) are shown.

The voltage waveform applied to the m-th column electrode is in opposite phase to the voltage waveform applied to the first-row electrode, except for the first two shots, so the cell (1st row, 2nd column) is lit. mode.

On the other hand, since the pulsed voltage applied to the n-th column electrode is in phase with the pulsed voltage stiffened to the first row electrode (1st row, nth column), the cell is in the non-lighting mode, that is, it is turned off. mode. The pulsed voltage applied to the cell (row 1 and column 2m) is expressed by the potential difference between the pulsed voltage applied to the first row electrode and the mth column electrode, and has a waveform of 1-D in FIG. (
Similarly, the pulsed voltage applied to the cell (row 1, column n) is expressed as a potential difference as shown in FIG. 1-E.

The operation in period a during period H is exactly the same as in Japanese Patent Publication No. 55-48318, and this period is defined as the address state in the present invention. On the other hand, the voltages applied to the lit cells and unlit cells during the b period of the H period are turned on, as shown in FIG. 1-D and 1-E.

This is exactly the same regardless of whether the light is turned off, and this period is defined as a hold state.

First, the operation in the address state is to apply a pulsed voltage between the electrodes of the plasma display panel to make it move. When causing a discharge, one discharge cell in the plasma display panel sets the discharge voltage to the minimum discharge starting voltage
), if the voltage at which all cells of the plasma display panel discharge is defined as the maximum discharge starting voltage (VDmax), one electrode of the plasma display has VDmi
A pulsed voltage higher than n and lower than VDmax (,
VDmi) is applied, and a pulsed voltage (vl) of the opposite phase and the same phase is applied to the other electrode.
n>1Vol lV+117) When the conditions are met, the discharge stops and VDmax<l VOl + l V, l
Discharge starts when the following conditions are met.

In the hold mode, as shown in the voltage waveforms of periods (b) in FIGS. 1-D and 1-E, a pulsed voltage having an amplitude of (V o ) is applied regardless of whether the light is on or off. The state created by the address state applied prior to the hold state is maintained during this period for display.

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

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

Next, according to the present invention, C in FIG. 1 is newly provided.
The period will be explained. During this period, Figure 1 1-B,
As in 1-C, a pulse for the light-off mode is applied regardless of the presence or absence of data.

At this time, since the same pulse is applied to all data-side electrodes, the influence of stray capacitance between data-side electrodes can be ignored, and the output of the drive circuit and
The difference in waveform and voltage at the tip of the electrode is reduced.

Furthermore, during this period, all the discharge cells stop discharging, so there is no spread of discharge from adjacent cells. In the end, in the address state of the C and C periods, compared to the conventional drive method, cells that should be discharged are a little more difficult to discharge due to the pulse of the turn-off mode in the C period, but cells that should not be discharged are Since the discharge completely stops during this period, there is no spread from adjacent cells. In other words, by increasing the voltage that causes erroneous lighting on display, the drive voltage can be widened and increased.

Additionally, in general, when the pulse frequency is increased, it becomes difficult to eliminate the time lag between the scan-side pulse voltage and the data-side pulse voltage due to the speed of the switching operation that creates the output state of the drive voltage, resulting in erroneous lighting. The voltage becomes low.

However, according to the present invention, even if the frequency of the address state is increased and the false lighting voltage is low, the false lighting voltage can be further increased by inserting an erase pulse in the C period. Brightness can be increased. On the other hand, according to the present invention, brightness can be increased by increasing the frequency of the hold state during period b. At this time, by further lowering the frequency of the C and C periods, it is possible to lower the time constant formed by the data-side electrode and the stray between the electrodes, thereby giving the entire panel a waveform that is almost the same as the output waveform of the circuit. This also has the effect of making the operation more stable. Although a narrow pulse is drawn next to the erase pulse in FIG. I got a range result.

〔Effect of the invention〕

As explained above, the present invention includes a period in which display is performed in an address state and a period in which display is performed in a hold state during one scanning period, and furthermore, in the address state, during the first part of the period, data is not displayed. This is the period in which the same pulsed voltage as when there is no data is applied regardless of the presence or absence of data, and by making the frequency of the pulsed voltage applied to the scan electrode in the hold state at least higher than the frequency in the address state,
The driving voltage range can be widened and increased. Additionally, it is possible to increase brightness and improve production yield.

[Brief explanation of the drawing]

FIG. 1 shows applied voltage waveforms in a first embodiment of the present invention. FIG. 2 shows the state of the pulsed voltage applied to the scanning electrodes. 1-A, 2-A... Pulse voltage applied to the scan electrode of the first row, 1-B... Pulse voltage applied to the data electrode of the m-th column, 1-C... Pulse voltage applied to the n-th column data electrode, 1-D.
...(1st row, 1m column) State of the voltage applied to the cell, 1-E...(1st row, nth column) State of the voltage applied to the cell, 2-B... ... Pulse voltage applied to the second row scan electrode, 2-C... Pulse voltage applied to the third row scan electrode, 2-D...
Vertical synchronization signal, 2-E...Horizontal synchronization signal. Agent: Susumu Uchihara, Patent Attorney, Figure 1, Ward 2

Claims (1)

[Claims] A voltage is sequentially applied in a time-division manner to one scanning electrode group of a plasma display panel whose electrodes are covered with a dielectric material to perform scanning, and the voltage applied to each scanning electrode is In a plasma display refresh drive method in which a voltage is applied to other data-side electrode groups in synchronization according to the presence or absence of data to drive the display, there is a period in which display is performed in an address state during one scanning period and a period in which a display is performed in a hold state. In addition, in the address state, the first part of the period is a period in which the same pulsed voltage as when no data is applied regardless of the presence or absence of data, and the period in which the pulse voltage is applied to the scanning electrode in the hold state. A method for driving a plasma display, characterized in that the frequency of the applied pulsed voltage is higher than at least the frequency of an address state. Note that the address state and hold state referred to here are defined as follows. That is, in synchronization with the pulsed voltage applied to the scan electrode during one scan period when one scan electrode is selected, and in addition, the data side electrode corresponding to the cell to be displayed has an opposite phase, and the cell that should not be displayed is synchronized with the pulse voltage applied to the scan electrode. The state during which a pulsed voltage of the same phase is applied to the data-side electrode corresponding to the display is called the address state, and the pulsed voltage that had been applied to the data-side electrode is stopped, and the charge created in the address state is called the address state. A state during a period in which the particles are driven only by pulsed voltages applied to the scanning electrodes is defined as a hold state.