JPS6328309B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display device, and more particularly to a display device that is compatible with print formats and cannot display everything in the line direction (hereinafter referred to as a partial line display device).

A display device is an input/output device that displays output data from a computer on a CRT, for example, and can monitor input data from an operator's key operations on the CRT, edit it, and input it to the computer. .

Data sent from the electronic computer is received by the interface section, once stored in the refresh memory, read out by the control section at a fixed timing, and sent to the display section through the character generator. The data in the refresh memory is stored in character codes, but since the characters on the display need to be displayed as patterns, the character codes are converted into character patterns in the character generator.

Conventionally, display devices used for general-purpose input/output devices, terminal devices, system consoles, word processors, etc. have been display devices that are compatible with print formats and can display all line directions (hereinafter referred to as full-line display devices). Ta.

However, in recent years, partial line display devices have come into use mainly for economical reasons. In the case of full line display, the character capacity of the display buffer and the number of displayable digits are the same, so the characters can be displayed sequentially from the left end, but in the case of partial line display, the number of displayable digits is the same in the row direction. Since the number of digits is smaller than the number of digits, it is not possible to display everything in the row direction, and the displayed characters move every time there is a new input, which has a negative effect on the operator's eyes.

On the other hand, in a full-line display, input characters are displayed in a fixed manner, so there is no adverse effect on the operator's eyes, and the operation is easy, but it is more expensive than a partial-line display.

SUMMARY OF THE INVENTION In order to solve these conventional problems, it is an object of the present invention to provide a partial line display device that can realize character fixation and cursor movement methods and ease of operation in a full line display device.

In order to achieve the above object, the display device of the present invention includes a display capable of displaying a predetermined number of character digits in the row direction, a display buffer device capable of holding character data greater than the number of character digits that can be displayed on the display, means for instructing the cursor display position on the display; displayable digit number holding means for holding the number of displayable digits on the display; and update shifting for holding the number of updated shifts when updating the screen in the row direction. information holding means, and when the number of characters to be displayed exceeds the number of displayable digits, after updating the plurality of characters before the cursor display digit, which is calculated from the number of displayable digits and the number of updated digits to be sent, over the entire display screen; It is characterized in that it is equipped with a display control means for displaying on the screen in front of the cursor digit.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of main parts of a display device showing one embodiment of the present invention, and FIG. 2 is an explanatory diagram of the operation in FIG. 1.

In FIG. 1, the refresh memory, character generator, etc. are the same circuits as in the prior art, so their storage is omitted.

Cursor address register A that indicates the cursor display position for full-line display, encoder B that determines the number of displayable digits, 1-line data buffer M that stores display characters, and buffer address that counts the address of that buffer. - A counter H, a control circuit N for controlling the display, and gate groups O, P, Q, and R for separating display inputs of cursor address and data are provided.

In addition to these, the present invention is new, and includes an encoder C that determines the number of overlapping characters to be displayed immediately before the cursor, a cursor address register G that indicates the actual cursor position on the display, and a cursor address a and the number of displayable digits. a comparison circuit I that compares cursor address a and the output of encoder C, a subtraction circuit J that subtracts the output of encoder C from cursor address a, an addition circuit K that adds the contents of buffer address counter H and the output of encoder C, and encoder B. A preset counter L is provided which decrements the output one by one and sends a counter output j to the control circuit N when it reaches zero.

The present invention, as shown in FIG.
By using a display method similar to partial-page and full-page display devices, when the character at the cursor position cannot be displayed on the display, several characters before the cursor are overlapped before and after the screen is updated. This improves operability for the operator and does not adversely affect the eyes.

In the following, the process of inputting data to the 1-line data buffer M and the process of setting data to the cursor address register A indicating the cursor position in the 1-line data buffer M will be omitted, and the above two circuits will be explained. The explanation will start from the point in time when proper data is set in the control circuit N and the display start signal STA is input to the control circuit N.

The display unit DPL is connected to the display interface I/F, and first, cursor address data x is input to AND gate O.
Subsequently, display character data y is input from one line data buffer M to AND gate P.

In Figure 2, the initial state (INL) when N=10 and Nl=7, when 9 characters are input (9CH), when 10 characters are input (10CH), when 16 characters are input (16CH), and when 17 characters are input (17CH), cursor address register A (CAR1), cursor address register
The contents of register G (CAR2), buffer address counter H, 1-line data buffer (1LNBUF), and display section (DPL) are shown.

In Fig. 1, first, strobe CL, (1)=
When 1, the contents of cursor address register A are sent to cursor address register G,
Buffer address counter H is reset to 0, and preset counter L is preset to N.

Next, the input i indicating a≧b is tested in the control circuit N.

If the value of the cursor address register G becomes larger than the number of displayable digits N and a≧b, then i=
1, so strobe(2)=1, strobe(1)
= 1, and the cursor address register G
The value N1 of encoder C is subtracted from the value of , and the result is set in cursor address register G through AND gate D and OR gate F.

Further, the value of buffer address counter H and the value N1 of encoder C are added, and the result is set in buffer address counter H again.

For example, in the case of FIG. 2, the value N of encoder B is 10, and the value N1 of encoder C is 7, so
If you enter 10 or more characters, i=1, for example
When 10 characters, 16 characters, and 17 characters are input, the cursor address register G is 3, (10-
7), 9, (16-7), 3, and (17-7-7) are set, and buffer address counter H is incremented to N1 = 7 only when strobe (1) = 1. 7, 7, and 14 are set respectively.

In this way, subtraction and addition are repeated, i=0
Run this until

Next, when i=0, strobe(3)=1 and strobe(4)=1, so the cursor address
The value x of register G passes through AND gate 0, OR gate Q, and interface I/F to the display section.
Transferred to DPL.

For example, in the case of FIG. 2, i=0 in the initial state and when nine characters are input, and the cursor address x is sent to the display unit DPL and displayed.

Next, input j is tested in control circuit N.

When j=0, strobe (4)=1, and the content y of the 1-line data buffer M addressed by the buffer address counter H is input to the AND gate P, the OR gate Q, and the interface I. /F and is transferred to the display unit DPL and displayed.

When strobe (5) = 1, the contents of buffer address counter H are incremented by 1, and the contents of preset counter L are incremented by 1.
be done.

This operation is repeated until j=1.

When j=1, the strobe (6) becomes 1, and the control circuit N notifies the display unit DPL of the end of data transfer.

In the above explanation, when the characters that should be displayed cannot be displayed, the characters before the cursor are displayed from the left side, overlapping with the characters before the update.
The value N1 of encoder C was set to 7, and the number of characters to be displayed in overlap at the time of update was fixed at 3.

In another embodiment of the present invention, the number of characters displayed simultaneously can be made variable.

FIG. 3a is an explanatory diagram of the operation at the time of data input in the case of N=10 and N1=7, and FIG. 3b is an explanatory diagram of the cursor shift operation in the case of N=N1=10.

In a word processor or the like having a partial line display device, it is often convenient to use different display methods during data input and editing operations. For example, when inputting data, the number of characters in the overlap display is displayed in front of the cursor, and when operating the character shift or word shift keys during editing, the number of characters in the overlap display in front of the cursor is set to 0. This will improve operability.

Therefore, as shown in FIG.
Provide multiple switch SWs, and set the value of N1 to 0,
Change it to 1, 2...9, 10, etc.

In Figure 3a, N=10 and N1=7 are set, so as explained in Figure 2, the input character is 0 in the initial state INL, so the cursor display stops at the left edge. There is. When 9 characters are input, since i=0 and j=0, 1 line data
The output y of the buffer M is displayed as is, and the cursor display stops at the right end. Next, when 10 characters are input, i=1 and j=0, so the value x of the cursor address register G becomes 3, the value of the buffer address counter H becomes 7, and the display section
In DPL, after all displayed characters disappear, one line
8 corresponding to address 7 of data buffer M;
9 and 0 are displayed overlappingly at the position corresponding to display address 3 from the left end, and the cursor indicates the next position.

Next, when 16 characters are input, the display DPL becomes full again. When 17 characters are entered, they disappear, and then the 3 characters in front of the cursor are displayed overlapping from the left edge, just like when 10 characters were entered.

In FIG. 3b, for character or word shift, the operator switches the switch SW using a dial or the like and sets N1=10. As a result, although it is a partial line display device, the display method is the same as in the case of a full line. That is, in the initial state, a predetermined number of characters are already stored in one line data buffer M, and 10 characters are displayed from the beginning. At this time, the cursor display indicates the value 0 of the cursor address register G.

Next, if you want to shift 9 characters, the cursor
By setting the value of address register G to 9, it is possible to shift only the cursor position and display it at the right end while leaving the displayed characters unchanged. In addition, in the case of a 10-character shift, all characters are erased once in order to update the display characters, and then the buffer address counter H indicates buffer M positions a to j, and the cursor address register Point the cursor at the value of G, 0.

As explained above, according to the present invention, it is possible to improve economical efficiency by using a partial line display device, and also to use the method of character fixation and cursor movement in a full line display device, and when updating the screen, the cursor Since the previous multiple characters are redisplayed on the updated screen, operability can be improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of main parts of a display system showing an embodiment of the present invention, FIG. 2 is an explanatory diagram of the operation of FIG. 1, and FIG.
The figure is an explanatory diagram of the operation of a display method showing another embodiment of the present invention. A, G: Cursor address register, B,
C: Encoder, D, E, O, P: AND gate, F, Q: OR gate, H: Buffer address counter, I: Comparison circuit, J: Subtraction circuit,
K: Adder circuit, L: Preset counter, M:
1 line data buffer, N: control circuit,
CL: clear signal, STA: start signal, x: cursor address, y: character data, DPL: display section, I/F: interface.

Claims (1)

[Claims] 1. A display capable of displaying a predetermined number of character digits in the row direction, a display buffer device capable of holding character data greater than the number of character digits that can be displayed on the display, and means for indicating a cursor display position on the display; Displayable digit number holding means for holding the number of displayable digits of the display, update shift information holding means for holding the updated shift number when updating the screen in the row direction, and displayable digits for the number of characters to be displayed. display control means for displaying a plurality of characters before the cursor display digit, which is determined from the number of displayable digits and the update number of digits, on the screen in front of the updated cursor digit over the entire display screen; A display device comprising: