JPH0648427B2 - Driving method for plasma display - Google Patents

Description

The present invention relates to a method of driving a plasma display, and more particularly, to an AC refresh type plasma display (PD).
This is related to the driving method of P).

Conventionally, as a method of driving an AC refresh type plasma display (PDP) of this type, a voltage waveform applied to either one of an insulator and an external electrode group facing each other via a discharge space is time-divided. Applied to the other electrode group, a pulse voltage of opposite phase is applied to the other electrode group when lighting the voltage waveform applied to the one electrode group, and a DC voltage is applied to the other electrode group when not lighting. It is generally known that stable operation is exhibited by doing.

In the conventional driving method described above, the power consumption of the driving circuit is maximized when a pulse voltage having an opposite phase corresponding to lighting is applied to all the data-side electrode groups. Further, the brightness of the AC refresh PDP is determined by the number of pulses included in a unit time, but if the number of pulses is increased, the power consumption of the drive circuit increases, so that the drive frequency is limited and sufficient brightness is obtained. There was a drawback that was difficult.

On the other hand, if there is a temporal shift between the high frequency pulses applied to the scan electrode group and the data electrode group, there is a drawback that the drive voltage range is narrowed.

Furthermore, when a transparent electrode is used for 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 formed. , And the voltage are different, there is a drawback that uneven brightness occurs.

The present invention provides a driving method which eliminates the above-mentioned drawbacks of the conventional AC refresh type plasma display driving method. That is, the waveform of the voltage applied to the row electrodes and the waveform of the voltage applied to the row electrodes are opposite to the waveform of the voltage applied to the row electrodes depending on the presence / absence of the display. One scanning period includes a period in which a DC voltage having no relation to the column electrodes is applied, and the power consumed during the period in which a voltage similar to that in the conventional driving method is applied is the same as that in the conventional driving method. The power that is the same, but has nothing to do with the waveform of the voltage applied to the row electrodes, that is, the power consumed during the period when the DC voltage is applied to the column electrodes, is the power consumed between the column electrodes. Because it is possible, it is significantly reduced.

Further, by lowering the driving frequency during the same driving as the conventional driving method and increasing the frequency during the period when the DC voltage is applied to the row electrodes, the driving can be stabilized and the power consumption can be further reduced. .

According to the driving method of the AC refresh type plasma display of the present invention, an electrode group is formed on a glass plate, and two glass plates each having an electrode group covered with a dielectric electrode are opposed to each other with dielectrics kept at appropriate intervals. When a panel-shaped voltage is applied between the electrodes of a plasma display panel that has a structure in which the glass frit is hermetically sealed and neon gas is sealed inside the panel, only one of the electrodes is driven. When a panel voltage is applied and the other electrode is kept at 0 potential to cause a discharge between the electrodes, the discharge voltage of one discharge cell in the plasma display panel is the minimum unilateral discharge start voltage (VDmin), When the discharge voltage of all cells of the plasma display panel is defined as the maximum discharge start voltage (VDmax), one electrode of the plasma display has a voltage lower than VDmin. Applying a scan-like voltage (V0) advance, the other electrode, at the same time applying a pulse voltage of opposite phase (V1), VDmax <| V0 | + | V1
This is an improved method of driving by utilizing the fact that the discharge is started when the condition of | is satisfied.

When a pulsed voltage that is higher than the maximum single discharge start voltage is applied to one electrode and a DC voltage is applied to the other electrode, all cells in the panel start to discharge, but the discharge is started after the voltage is applied. It takes a long time to start, and the discharge delay time in the AC refresh method is generally 5 microseconds or more, though it depends on the applied voltage. On the other hand, the response of the discharge after the discharge is started is very fast and is 100 nanoseconds or less.

The driving method of the AC refresh type plasma display of the present invention utilizes this discharge delay phenomenon. A pulsed voltage higher than the one-sided discharge starting voltage is applied to one of the electrodes, and a display method similar to the conventional driving method is used. Depending on the presence or absence, a DC voltage or a pulsed voltage of opposite phase is applied to the other electrode to discharge the discharge cells to be discharged, and then the pulsed voltage of the other electrode is removed and applied to only one electrode. The pulse-shaped voltage that keeps that state is maintained, and before the non-lighted cell is lit by the pulse-shaped voltage of one electrode, the state similar to that of the conventional driving method is repeated to obtain P
This is a method of driving the DP.

That is, if the state driven by the conventional phase select method is defined as the address state, and the state in which the address state is maintained by the application of the pulsed voltage to one electrode is defined as the hold, the driving method of the present invention is It is characterized by alternately repeating the state and the hold state.

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 the pulsed voltage applied to the scan electrodes.

The plasma display panel used in the driving method of the present invention comprises two glass plates each having an electrode group coated with a dielectric, the electrode groups being opposed to each other, the respective electrode groups being orthogonal to each other, and the intersection being a light emitting point of the display. Is designed to be.
In order to drive this plasma display panel, generally, the first electrode is selected only during the H period by the horizontal synchronizing signal shown in 2-E of FIG. 2 and the wave shown in 2-A of FIG. 2 is selected. A pulsed voltage with a high value V0 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 with respect to the first horizontal electrode.

Next, after a certain period (blanking period), the second
Electrode is selected, and V0 is applied only during the H period like the first electrode.
A pulsed voltage having a peak value of is applied to the second electrode. (See FIG. 2B) The pulsed voltage is applied to the third electrode after the pulsed voltage is applied to the second electrode, and thereafter, this operation is sequentially repeated, and the vertical synchronization signal is transmitted. Time until entering (V)
Continue. The vertical synchronization signal shown in FIG. 2D returns the state in which the first electrode can be selected.

That is, the scanning of the method is sequentially scanned by the horizontal synchronizing signal, and is returned to the original state by the vertical synchronizing signal input after all the horizontal electrodes are scanned. The vertical sync signal matches the refresh frequency of the display, typically 60
Selected over cycles. On the other hand, the number of horizontal synchronizing signals included in one period of the vertical synchronizing signal matches the number of scanning lines,
Generally, the number of scan lines does not match the number of scan electrodes of the panel, and the number of scan lines is larger than the number of scan electrodes of the panel.

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

1-C and 1-D in FIG. 1 are the first row electrode and the m-th electrode, respectively.
7 shows voltage waveforms applied to discharge light emitting point (1 row, m column) cells and (1 row, n column) cells formed at the intersections of the column electrodes and the nth column electrode.

Since the voltage waveform applied to the m-th column electrode has an opposite phase to the voltage waveform applied to the first-row electrode, (1 row, m
The cells in the (column) are in the lighting mode.

On the other hand, since the voltage applied to the n-th column electrode is a DC voltage (1 row, n column), the cell is in the non-lighting mode, that is, the light-off mode.

(1 row, m column) The pulse voltage applied to the cell is the first
It is represented by the potential difference between the pulsed voltages applied to the row electrode and the m-th column electrode, and has the waveform 1-D in FIG.

The pulse-like voltage applied to the cell (1 row, n columns) is also represented by the potential difference as shown in FIG. 1-E.

According to the driving method of the present invention, during the H period in which the row electrodes are selected, the pulse voltage or the DC voltage is applied to the column electrodes according to the presence or absence of the display, and the DC voltage is applied regardless of the display. It is different from the conventional driving method that the period b is set.

The operation in the period a during the H period is exactly the same as the conventional driving method, and this period is defined as an address state in the present invention.
On the other hand, the voltage applied to the lighted cells and the light-off cells in the period b during the H period is exactly the same regardless of whether it is turned on or off, as shown in FIGS. 1-D and 1-E in FIG. Defined as a hold state.

In the hold mode, a pulse voltage having an amplitude (V0) is applied regardless of whether the light is turned on or off as shown by the voltage waveforms in the period (a) of FIGS. 1-D and 1-E. In this state, the state created by the address state applied prior to the above is maintained for this period, and the display is performed. That is, in the address state, in the lighting state (1 row, m
The cells in the (column) are discharged during the period (a), and the cells are filled with charged particles generated by the discharge, so discharge can be easily started even in the hold state where a voltage lower than that in the address state is applied. To do.

On the other hand, in the non-lighted state (1 row, n column) cells in the address state, it takes a certain time before the discharge is started by the voltage applied in the period a + b, and the period (a + b) is appropriately selected. Then, the voltage at which discharge does not start in the hold state can be determined.

FIG. 3 is a layout diagram of the pulse voltage of the second embodiment.

FIG. 3A shows a pulsed voltage applied to the N-row electrodes of the plasma display.

FIG. 3B shows a pulsed voltage applied to the m-row electrodes, and FIG. 3C shows a pulsed voltage applied to the n-row electrodes.

FIG. 3D shows a pulsed voltage applied to a cell (N rows, m columns) formed at the intersection of the N-row electrode and the m-column electrode,
FIG. 3E shows a pulsed voltage applied to a cell (N rows, n columns) formed at the intersection of the N row electrode and the n column electrode.

In FIG. 3, the period indicated by c indicates the blanking time, and the period indicated by a is the time for displaying in the address state. The period indicated by b is the time during which the display is performed in the hold state. The period of a + b + c is one scanning time.

As described above, the present invention provides an effect that a high frequency voltage is not applied to the data side electrode during one scanning period, and the power consumed between the data side electrodes during this period can be reduced and the scanning is performed during that period. There is an effect that the frequency of the pulse voltage applied to the side electrode is increased and the number of discharges in one scanning period is increased to increase the brightness.

Furthermore, in the panel where the NESA electrode is used for the data side electrode, by lowering the frequency of the address period below the time constant formed by the stray between the NESA electrode and the electrode, a waveform that is almost the same as the circuit output waveform can be obtained. There is also an effect that it can be given and the operation becomes stable.

[Brief description of drawings]

FIG. 1 shows an applied voltage waveform according to an embodiment of the present invention. FIG. 1-A shows the pulse voltage applied to the scan electrode of the first row, FIG. 1-B shows the m-th column data side electrode, and FIG. 1-C shows the n-th column data side electrode. The pulse voltage waveforms applied are shown respectively. 1-D and 1-E are (1 row, m column) (1
(Row, n column) shows the state of voltage applied to the cell. FIG. 2 shows the state of the pulsed voltage applied to the scan electrodes. FIG. 3 shows the state of the pulse-like voltage applied to the row and column electrodes of the second embodiment.

Claims (1)

[Claims] 1. A voltage is sequentially applied to a scanning electrode group of a plasma display panel whose electrodes are covered with a dielectric material in a time-division manner and scanning is performed in synchronization with the voltage applied to each scanning electrode. In a refresh driving method of a plasma display in which a voltage is applied to other data side electrode groups according to the presence / absence of data, a display is performed in a hold state and a period in which display is performed in an address state during one scanning period. And a frequency of the pulsed voltage applied to the scan electrodes in the hold state at least higher than the frequency in the address state. The address state and the hold state referred to here are defined as follows. That is, the data-side electrode corresponding to the cell to be displayed during one scanning period in which one scan electrode is selected is displayed with a pulse voltage of the opposite phase synchronized with the pulse voltage applied to the scan electrode. A DC voltage is applied to the data-side electrode corresponding to a cell that should not be displayed in the address state, and the pulse-shaped voltage applied to the data-side electrode is stopped to charge the data The state of a period in which only the pulse voltage applied to the particles and the scan electrode is driven is defined as the hold state.