JPS6114517B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the scanning method of cursor display electrodes in a character display device.

Conventionally, in a character display device using a discharge display element in which selected intersections of row and column electrodes emit light, each row electrode is sequentially scanned in a time-division manner, and each column electrode displays character data and a cursor in response to the scanning of the row electrode. A display method in which display data is input is generally known. In such display systems, the character format is usually 5 x 7 dots or 7 x 9 dots.
The cursor is made up of dots, and is displayed as a 5-dot or 7-dot underline below the character at the access position in accordance with the character format.

Therefore, the row electrodes of the discharge display element consist of 7 or 9 character display electrodes and one cursor display electrode for each character row, and these electrodes are repeatedly and sequentially scanned over all character rows. has been done. Assuming that the character format of the display device is 5.times.7 dots and the row direction display capacity is 10 character lines, 70 character display electrodes and 10 cursor display electrodes in the row electrodes are repeatedly scanned. Such display is usually only one specific character, and in reality only one cursor display electrode is selected, and the remaining nine
Since the cursor display electrodes are scanned uselessly in a non-selected state, the brightness of the displayed characters is reduced.

An object of the present invention is to improve the display method of the discharge display element in order to address the above-mentioned drawbacks. That is, among the cursor display electrodes, only selected electrodes corresponding to the actual cursor display position are scanned, and the number of scanning electrodes of the row electrodes is reduced, thereby improving the above-mentioned drawbacks.

Next, the present invention will be explained in detail with reference to the drawings. The figure is a block diagram showing one embodiment of the present invention. In the figure, 1 is a discharge display element, 2 is a row electrode, 3 is a column electrode, 4 is a display cell, 5 is a row electrode drive circuit, 6 is a column electrode drive circuit, and 7 is a device for sequentially refreshing the row electrodes. A scanning control section, 8 a cursor address control section for specifying the cursor position, 9 a cursor address detection circuit, 10 a clock pulse generation circuit, 11 a character data generation circuit, and 12 a scanning pulse.

Scan pulses 12 ₁ , 12 ₂ , 12 ₃ . . . are output from the scan control section 7 every time a clock pulse from the clock pulse generation circuit 10 is input.
12 m, and further scan pulses 12
is stepped up to a voltage necessary for discharging the display element in the row electrode drive circuit 5, and then the corresponding row electrodes 2 ₁ , 2 ₂ , 2 _{3 . .} . 2 m are successively scan-driven. On the other hand, character data generation circuit 11
The character data outputted from the column electrodes 2 is input to the column electrode drive circuit 6 in correspondence with the scanning of the row electrodes 2, and is stepped up to a voltage necessary for discharging the display elements, thereby selectively driving the corresponding column electrodes 3. Eventually, the display cells 4 at the intersections of the selectively driven row and column electrodes light up, and characters corresponding to the character data can be displayed on the display element 1 .

As mentioned above, the character format is 5x7.
It is assumed that the dot and line direction display capacity is 10 character lines, and the cursor display device is at the position of the first character line and first character string. The address of the cursor address control unit 8 is fixed to the first character line and the first character string.
During the period when the row electrode 2 of the character line is being scanned, among the address values of the scan control unit 7, the character line address value becomes the first character line and matches the character line address value of the cursor address control unit 8. A signal is generated at the output of the cursor address detection circuit 9. When a signal is generated at the output of the cursor address detection circuit 9, the scan control unit 7 is set so that eight scan pulses 12 ₁ , 12 ₂ , 12 ₃ ..... 12 ₈ are generated sequentially for the first character line. , 12 ₁ , 12 ₂ ......
. . 12 ₇ sequentially scans the character display row electrodes 2 _{1 , 2} 2 . The characters to be displayed on the first character line are displayed. Next, a scanning pulse ₁₂₈ is driven. At this time, the address value of the first character string among the address values of the cursor address control section 8 is input to the column electrode drive circuit 6, and the corresponding column electrodes 3 ₁ , 3 ₂ , 3 ₅ are controlled by the output thereof. driven, first
Five display cells 4 below the characters of the first character string in the character line are lit to display a cursor.

Next, when the row electrode 2 of the second character line starts to be scanned, the character line address value of the scan control unit 7 becomes the second character line and differs from the address value of the cursor address control unit 8. No signal is produced at the output. Therefore, the scan controller 7 applies seven scan pulses 12 to the second character line.
₉ , 12 ₁₀ ...... 12 ₁₅ are set so that character display row electrodes 2 ₉ , 2 in row electrode 2 are generated.
₁₀ ......2 ₁₅ are sequentially scanned. In other words, the row electrode ₂₁₆ for cursor display is not scanned because no corresponding scan pulse is generated. Similarly, the 3rd character line, the 4th character line, etc.
The row electrodes 2 corresponding to the 10 character rows are sequentially scanned one after another, and the row electrodes 2 ₂₄ , 2 ₃₂ , . . . are used for cursor display.
......2 ₈₀ is not scanned. In the display system according to the present invention, the number of row electrodes scanned in one scanning period from the first character line to the tenth character line is 71. In other words, compared to the conventional method in which all row electrodes for displaying a cursor on each character line are scanned, 80 row electrodes are scanned in one scanning period.
It has the excellent feature that the number of scanning electrodes can be reduced and the display can be correspondingly brightened by about 10%.

In the description of the present invention, the scanning order of the character display row electrodes and the cursor display row electrodes is described as alternating for each character row, but after all character display row electrodes have been scanned, Of course, the effect of the present invention does not change at all even if the scanning order is changed, such as scanning the cursor display row electrode.

[Brief explanation of the drawing]

The drawings show block diagrams illustrating embodiments of the invention. In the figure, 1: discharge display element, 2: row electrode,
3: Column electrode, 4: Display cell, 5: Row electrode drive circuit, 6: Column electrode drive circuit, 7: Scan control section, 8:
11 shows a cursor control section, 9: cursor address detection circuit, 10: clock pulse generation circuit, and 11: character data generation circuit.

Claims (1)

[Claims] 1. Each row electrode of a display element having a plurality of row and column electrodes arranged opposite to each other is sequentially scanned in a time-division manner, and each column electrode displays character data and a cursor in response to the scanning of the row electrode. In a method for driving a display element having a cursor display electrode such that display data is input, the row electrode to be scanned has a character display row electrode and a cursor display row electrode, and each of the character display row electrodes is 1. A method for driving a display element having a cursor display electrode, characterized in that the electrodes are sequentially scanned, and only a selected specific row electrode for the cursor display row electrode is scanned.