JPS594716B2 - Display element drive method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an external electrode type discharge 5 in which an intersection of selected row and row electrodes among a group of electrodes arranged in a matrix in the row and row direction and facing each other emits light. Regarding.

Conventionally, as a driving method for this type of display element, the Unidrive method as shown in FIG.
A patent application has been filed as 535)10.

That is, the display element 1 shown in FIG. 1 has row electrodes 2 parallel to each other (hereinafter, suffixes will be omitted unless a specific one is shown).

), and a display cell 4 is formed at the intersection of each matrix 15 .
Further, each electrode of the row electrodes 2 is connected correspondingly to each output terminal of the row driver 5, and each electrode of the column electrodes 3 is connected correspondingly to each output terminal of the column driver 6.
Input data 907 is connected to the input of each column driver 6. Further, the output of a clock pulse generator 9 for controlling the timing at which row and column electrodes are selected is connected to the input of a counter 10, and the output thereof is connected to the input of a decoder 11. The output of the high frequency pulse generator 58 necessary for alternating current discharge of the display element is input to the decoder 11. Furthermore, the configuration is such that the output of the decoder 11 is connected to the input of the row driver 5. Next, this first
The operating principle of the display method shown in the figure and the defects associated with its operation will be described.

The 10 clock pulses are counted down in a counter 10 by an amount equal to the number of row electrodes to be driven, for example n, and then decoded again in a decoder 11, producing at its output a scanning pulse 12 with a pulse width and a period nt.

Each scanning pulse 12,,ζ5122,...12n
produces outputs sequentially. The scanning pulse 12 is mixed with the output of the high-frequency pulse generator 8, inputted to the row driver 5, and stepped up to a voltage higher than the discharge start voltage of 1q to become a high-frequency discharge pulse, which sequentially moves the corresponding row electrodes 2. , drive selection.

On the other hand, the input data 7 is input to the column driver 6.

The column driver 6 is composed of a switching element such as a transistor, and its output is either short-circuited to a fixed potential such as ground, or open, depending on the presence or absence of input data 7. Each of the outputs of the column drivers 6 is correspondingly connected to each of the column electrodes 3. Assume that 21 of the row electrodes 2 are currently selected and only 31 of the column electrodes 3 are selected.

A high frequency pulsed voltage higher than the discharge start voltage is applied to the intersection of the row electrode 21 and the column electrode 31, that is, the display cell 411, causing discharge and light emission. The column electrodes 32, 33, . . . are in an open state because they are not selected, and the row electrodes 21
An induced pulse due to the high-frequency discharge pulse applied to the electrode is induced via the capacitance between the matrix and electrodes. In the end, the voltage between the electrode 21 and the column electrodes 32, 33, .
・It is the value obtained by subtracting the induced pulse voltage induced by 3n, and by making it lower than the discharge starting voltage, no discharge is caused. Therefore, by controlling the scanning of the row electrodes 2 and the timing of data input to the column electrodes 3, any part of the display element 1 can be turned on. In the display system described above, since the capacitance between the row and column electrodes is generally small, the amplitude of the induced pulse induced from the row electrode to the column electrode is very small, usually about 5% of the high frequency discharge pulse.

Therefore, if the amplitude of the high-frequency discharge pulse applied to the row electrode 2 is made 5% or more higher than the discharge starting voltage, a voltage higher than the firing voltage will be applied between the selected row electrode 2 and the unselected column electrode 3, and the intersection will be It has the disadvantage that it discharges and emits light and has a small operating margin. The present invention improves the above-mentioned drawbacks by applying a high-frequency pulse voltage in phase with the high-frequency discharge pulse applied to the row electrodes through a capacitor externally connected to each of the column electrodes. The present invention will be described in detail below with reference to the drawings.

FIG. 2 is a block diagram showing an embodiment of the present invention.

The driving method for the row electrodes 2 of the display element 1 is the same as the conventional method shown in FIG. On the other hand, one terminal of a capacitor 22 is connected to each column electrode 3, and the other terminal is connected to a discharge pulse driver 2 that amplifies the output of a high-frequency pulse generator.
0 output is connected. An example of a method for driving the column electrodes 3 will be described below with reference to FIGS. 3a to 3e. The output of the high frequency pulse generator 8 (FIG. 3a) is amplified by the discharge pulse driver 20, and the output has a sufficiently large amplitude and phase and is applied to the row electrodes.

A pick-up pulse 21 (FIG. 3b) is obtained as a high-frequency pulsed electric current equal to the high-frequency discharge pulse (FIG. 3c).
If the column electrode 3 is currently in a non-selected state and the output of the column driver 6 is in an open state, a capacitor 22 is connected to the column electrode 3.
An induced pulse (FIG. 3d) is applied via. By adjusting the amplitude of the pickup pulse 21 and the capacitance of the capacitor 22 and setting the amplitude of the induced pulse applied to the column electrode 3 to, for example, 20% of the discharge starting voltage of the display element 1, the row electrode 2
The amplitude of the high-frequency discharge pulse applied to
The display cell 4 does not emit light until it is raised to 0% (non-selected area in FIG. 3e). On the other hand, when the column electrode 3 is in the selected state and the output of the column driver 6 is in the short state and connected to a fixed potential terminal such as ground, the induced pulse is not applied to the column electrode 3 and the amplitude is lower than the discharge starting voltage to the row electrode 2. When a high-frequency discharge pulse with a large value is applied, the display cell 4 emits light (selected region in FIG. 3e). After all, it is possible to control whether or not the display cells 4 emit light by selecting or non-selecting the column electrodes 3 until the high-frequency discharge pulse applied to the row electrodes 2 reaches a voltage 20% higher than the discharge starting voltage. Therefore, the so-called operating margin can be made sufficiently large.

As described above, according to the present invention, since the amplitude of the pick-up pulse applied to the column electrodes can be freely controlled, the operating margin of the drive voltage can be made sufficiently large, and a stable display device without display errors etc. can be provided. can. In addition, in the present invention, the amplitude of the induced pulse is always increased compared to the conventional example regardless of the capacitance of the capacitor 22, so the effect of the present invention that the operating margin is larger than that of the conventional example is always obtained. There is no necessity to particularly limit the amplitude of the pulse. However, considering that the discharge starting voltage increases due to changes in the display element over time, it can be said that it is desirable that the amplitude of the induced pulse be at least 10% or more of the discharge starting voltage. In the embodiments of the present invention, a method in which row electrodes are scanned and input data is added to column electrodes is explained, but the present invention can also be applied to a method in which column electrodes are scanned and input data is added to row electrodes. Of course, the effect remains unchanged.

[Brief explanation of the drawing]

Figure 1 is a block diagram of a conventional display element and drive method;
The figures each show a block diagram of an improved display element driving system according to the present invention.

Claims (1)

[Claims] 1 A row electrode group including a plurality of row electrodes and a column electrode group including a plurality of column electrodes are arranged in a matrix, and the intersection of the row electrode and column electrode selected from the row electrode group and the column electrode group is arranged. In the driving method of an external electrode type discharge display element which discharges and emits light, a first means for applying a high frequency discharge pulse higher than a discharge starting voltage to a selected row electrode in a group of row electrodes of the discharge display element; a second means for applying a high frequency pulsed voltage having the same phase as the high frequency discharge pulse to each column electrode via a capacitor connected to each electrode of the group; A switching element connected to a fixed potential such as ground is turned on and off depending on whether each column electrode is selected or not.
and third means for not applying an induced pulse induced via the capacitor to a selected column electrode.