JPH04270B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a driving method for an external electrode type discharge display panel, so-called plasma display panel.

In this type of plasma display panel (hereinafter abbreviated as PDP), a plurality of generally transparent column electrode groups parallel to each other and a plurality of generally opaque row electrode groups parallel to each other are arranged in a matrix, and both A method is generally known in which an ionizable gas is interposed between electrode groups and the intersection of a selected row electrode and a selected column electrode is displayed by discharging and emitting light.

In the above-mentioned PDP, by controlling electrode selection of the row electrode group and the column electrode group in accordance with the input signal, an optical image corresponding to the input signal can be displayed. For example, one of the row electrode groups and the column electrode group, for example, each electrode of the row electrode group, is selectively scanned in a time-division manner, and the other electrode group, for example, the column electrode group, is scanned in synchronization with the scanning. By controlling the selection according to the input signal while maintaining the same, an optical image corresponding to the input signal can be displayed on the PDP surface. In an external electrode type PDP, it is necessary to drive it with an alternating current voltage, and the drive signal applied to the row electrode group and the column electrode group includes a high frequency pulse called a doggle pulse. FIG. 1 is a diagram showing a conventional embodiment. 4MHz crystal oscillator (O.
The signal generated from SC) 7 is counted down by a read counter (RC) 6 to generate an 8-bit read address signal a and an address signal b for a character generator (CG) 9, and further scan the PDP row electrodes. data and clock signal c are generated and input to the shift register (SR) 4. The shift register (SR) 4 has 8 rows x 8 lines = 64 parallel signal output terminals, and each of these has 64 row electrode drivers (RD).
2, and its output is connected to the row electrode of PDP1. Therefore, the signal input to the shift register (SR) 4 is transferred to the PDP1 by the row electrode driver (RD) 2.
The voltage is converted into a voltage sufficient to drive the PDP 1, and the 64 row electrodes for 8 rows of the PDP 1 are sequentially time-divisionally scanned at a period of approximately 200 μs. Therefore, one screen is displayed at a cycle of approximately 12.5 mS (80 Hz). Also,
Data d consisting of 7 bits for displaying an optical image on the PDP 1 in response to the above-mentioned scanning is written into the RAM 10 through the control circuit 11.
The write address of the RAM 10 is designated by a cursor counter (CC) 14 that designates the cursor position and an 8-bit address e. RAM1
The data written to 0 is read out by the read address signal a, converted into a character signal by a character generator (CG) 9, and input to a shift register (SR) 5. The shift register (SR) 5 has 32 digits x 5 = 160 parallel signal output terminals, each of which is connected to a column electrode driver (CD) 3, whose output is connected to the column electrode of the PDP 1. Therefore, the data signal input to the shift register (SR) 5 is converted into a voltage sufficient to drive the PDP 1 by the column electrode driver (CD) 3, and is input to the PDP 1, and is sent to the PDP 1 at the timing of scanning each row electrode to generate 160 signals for 32 digits. Apply the data signal.
On the other hand, on the display screen of this PDP display device consisting of 32 digits and 8 lines, the underline cursor that indicates the position where data will be written next is a comparator that is generated when the logic of read address signal a and write address signal e matches. (C) By inputting the output signal of 12 to the cursor display control circuit 8, the cursor is turned on.

Therefore, the underline cursor is displayed at a frequency of approximately 80Hz per screen, just like other character displays.
No flicker is perceptible to the human eye.

However, in such a PDP display device, 32
Part of the display capacity of 8 rows of digits, for example, all 32 digits of the 8th row, is used for key input, and the 32 digits of the 1st to 7th rows are used for key input.
When using the digits for displaying data from a machine such as a computer, press 32 on the 8th line for key input.
Lights up the underline cursor only for the digits.
Therefore, if data is input from the machine while an address is specified to any digit on the 8th line and the cursor is lit, the adder line cursor will be turned off, and any digit on the machine data display section 1 to 7 will be displayed. After writing data without address designation to the digit and displaying the character, it was necessary to designate the address again at the original 8th line position and light up the underline cursor. Therefore, in that case, the frequency of the underline cursor lit on one screen will be
When the frequency becomes lower than 80Hz, and when it becomes about 50Hz or lower, the underline cursor has the disadvantage of flickering.

The present invention eliminates these drawbacks and includes a counter for specifying the display position of characters such as numbers, letters, symbols, etc., and a latch for storing display position data of the cursor, and a counter for specifying the display position of the character. The present invention provides a display method for a discharge display panel, which is characterized in that the cursor can be displayed even during a period in which the cursor is displayed.

FIG. 2 is a block diagram showing an embodiment of the PDP driving method according to the present invention, which drives a PDP 1 having a display capacity of 32 digits and 8 lines as in FIG. 1 to display characters and an underline cursor. It is a device. The row electrode group of PDP1 is the same as in Figure 1: 4MHz crystal oscillator (OSC) 7, read counter (RC) 6, and shift register (SR).
4. The row electrode driver (RD) 2 scans sequentially and time-divisionally at a period of about 200 μs using a signal generated by a circuit formed of the driver (RD) 2.

In addition, the data for displaying the optical image corresponding to the above scanning is also stored in the control circuit (C) 1 as shown in Fig. 1.
1. Random access memory (RAM) 10.
A character generator (CG) 9, a read counter (RC) 6, a write counter (WC) 15 corresponding to the cursor counter in Figure 1, and an address switching circuit (AS) that switches the address signal between writing and reading. 13, shift register (SR) 5, and digit electrode driver (CD) 3
This circuit applies 160 data signals for 32 digits at the timing of scanning each row electrode of PDP1.

On the other hand, the underline cursor is created by adding a 5-bit address signal i that specifies digits 1 to 32 of an 8-bit address signal e to a latch (L) 16 that stores an arbitrary digit position on the 8th line, and Only when the 8th row is specified by the signal g obtained by ANDing the 3-bit address signal h that specifies the 1st to 8th rows of the 8-bit address signal e and the load signal f, any arbitrary digit is specified. The position is specified by latching the 5-bit signal that specifies the position.

The 5-bit address signal i latched in this way
is the signal obtained by comparing 5 bits a of the 8-bit read address signal of the read counter (RC) 6 with the comparator (C) 12 and ANDing the 3-bit address signal h, and the same logic. The signals are compared by a comparator (C) 12, and when they match, an output signal j is input to the cursor display control circuit 8. Therefore, according to the PDP display device of this embodiment, part of the display capacity of 8 lines of 32 digits, that is, all 32 digits of the 8th line, is used for key input, and 1
When using the 32 digits from line 7 to 7 to display data from a machine such as a computer, the underline cursor for key input can be controlled to light up automatically, and even if data is input from the machine, The underline cursor remains fixedly displayed at its original position until the next key input signal is input.

In other words, the frequency of the underline cursor that is lit on one screen is the same as the display frequency of characters such as numbers, text, symbols, etc., so the underline cursor does not flicker and the display quality is good.
A PDP display device is obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a conventional embodiment, and FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention. 1...PDP, 2...Row electrode driver, 3...
Digit electrode driver, 4, 5...Shift register, 6
...Reading counter, 7...Crystal oscillator,
8... Cursor display control circuit, 9... Character generator, 10... Random access memory, 11... Control circuit, 12... Comparator, 13... Address switching circuit, 14...
Cursor counter, 15...Writing counter, 16...Latch circuit.

Claims (1)

[Claims] 1. One electrode of the row and column electrode groups of a discharge display panel, in which the column electrode group and the row electrode group are provided so as to face each other at a predetermined interval and are substantially perpendicular to each other, and are filled with a gas that can be ionized during the interval. A display method for a discharge display board in which a group of electrodes is sequentially scanned in a time-division manner, and the other electrode group is selectively controlled by an input signal in response to the scanning to display a character and a cursor for specifying a display position at an arbitrary position. , comprising a counter for specifying the display position of the character and a latch for storing display position data of the cursor,
A display method for a discharge display board, characterized in that the cursor can be displayed even during a period when the display position of the character is specified.