JPS60144790A - Graphic display unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a graphic display device equipped with a video memory, and more particularly to a raster scanning type graphic display device that sequentially reads out the contents of the memory and displays an image. .

Prior Art In a conventional rask scanning type graphic display device with a video memory, a clock signal is input to a counter serving as an address control section, the X address is sequentially increased by this clock signal, and the Y address is increased by a carry signal of the X address. The number of responses is increased sequentially and the image is displayed on the entire display screen.

In other words, the order in which raster data is read from the video memory is fixed, and therefore it is possible to rotate an image on the display screen by 90°, 7g0°, 270°, etc. ．． ? When inverting the image around a straight line at θ°, /330, the entire contents of the video memory had to be rewritten, which had the disadvantage of requiring a long time to rewrite. .

OBJECTS OF THE INVENTION Accordingly, it is an object of the present invention to provide a graphic display device that allows images to be rotated or reversed without requiring a long period of time.

SUMMARY OF THE INVENTION In order to achieve the above object, the graphic display device according to the present invention includes means for selecting the progression of the X address between successive increases and successive decreases, and means for selecting the progression of the Y address successively. Means for selecting either increase or sequential decrease, and means for exchanging the X address and the X address are provided.

Effect of the Invention With this configuration, it is possible to sequentially decrease the X address and
The image can be rotated or reversed by decreasing the address, exchanging the X address and the X address, or by a combination of these.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings. FIG. 1 shows a block diagram of a graphic display device according to the invention, which device has an address control 1, an X address and an It is equipped with a memory 2 and a task scanning type display screen 3 for displaying graphics such as a CRT.
A clock signal is input to the address control section 1, and the X address is sequentially advanced by the clock signal, and the X address is sequentially advanced every predetermined X address by 1, and data is sent from the video memory to the display screen by raster scanning. The image is displayed.

Next, on the input side of the address control unit 10, an X address reverse command signal generator 4 and an X address reverse command signal generator 5 are provided.
and an X-X address advance replacement command signal generator 6 are connected, and the address control unit 1 receives an X address reverse command signal, an X address reverse command signal, and an X-Y address advance replacement command signal. is input. These command signals are 0
If ゛, then the address control unit 5 also
Addresses also increase normally, that is, sequentially in the forward direction, in accordance with the clock signal. Now, the X address reverse command signal is °゛/″
, the X address is sequentially decreased and moves in the opposite direction. Therefore, the image on the display screen 3 becomes an inverted image (that is, an image that is reversed with respect to the straight line (that is, the Y axis) with the inclination angle θ0). When the Y-address reverse command signal "/" is reached, the X-address decreases sequentially and moves in the opposite direction, so that the image on the screen 3 is inverted with respect to the X-axis.

When the XX address progress switching signal becomes "/", the X address progress and the X address progress are switched, and the X address progresses sequentially every time the X address progress reaches a predetermined value. On the other hand, the display screen 3 is raster scanned, and the read data is sequentially displayed in the horizontal direction. Therefore, in normal address progression, data that is visualized in sequence according to the X address will be displayed in sequence according to the progression of the X address by the XX address progression exchange signal.
An image inverted with respect to a straight line with an inclination of 5° is obtained. Furthermore, by combining these command signals, qOo,
7g00. ．． It is possible to obtain a rotation of 270° or a reversal with respect to a straight line with an inclination of 733°. Table 1 below shows each command signal and the state of the image when the figure "2" is projected on the front screen 3.

The configuration of the address control unit 1 is that the address control unit 1 normally uses a clock signal to advance the X address in the forward direction to create a normal image, and reverse the X address. The command signal causes the X address to advance in the reverse direction, the X address reverse command signal causes the X address to advance in the reverse direction, and the
Any type may be used as long as the progression of the X address and the X address can be switched by the X address progression exchange signal.

FIG. 2 shows an example of this address control section 1. As shown in FIG.

In Figure 1, β Ω-/data selectors 11.1
2 and two up/down counters 13 and 14 constitute an address control section, and the code/data selectors 11 and 12 select A and B under the control input of S for λ data inputs of A and B. The signal input to B is selectively output to Y.

In this example, when the control terminal S is "o", the input A is output to the output Y, and the signal to the input B is not output.

Further, in the up/down counters 13 and 14, clock pulses are input to terminals CK, and count outputs are input to the video memory. The D/U terminal is a terminal that allows you to select whether the counter 12 operates to decrease or increase the count, and when O''' is input to the terminal, it increases, that is, it functions as an amplifier counter. When "/" is input, the counter 12 decrements, or functions as a down counter.The RC terminal of the counter 12 outputs a carry (skip or carry down) signal.

As shown, the clock signal is transmitted to the first data selector 1
1 and input B of the first data selector. The X address reverse command signal is input to the up/down terminal D/U of the first up/down counter 13. The X address reverse command signal is sent to the first up/down counter 14
The signal is input to the up/down end D/U. The x-y address advance replacement command signal is input to the first and first data selector 11.degree. 120 control terminals S. 1st data selector I
The output Y of J is input to the clock terminal CK of the first Atsuzo down counter 13, and its output 15 is sent to the X address of the video memory 2.

The output Y of the first data selector 12 is input to the clock terminal CK of the first up/down counter 14, and its output 1
6 is input to the X address of the video memory 2. Further, the carry terminal RC of the seventh Atsuzo down counter 13 is connected to the input A of the first data selector 12, and the carry terminal RC of the first up/down counter 14 is connected to the input B of the first data selector 11. .

In operation, when each command signal is °°0'', when a clock signal is input, the clock signal is input to the first amplifier down counter 13 via the first selector 11 and counts up.Input B of the first data selector 12 and output Y are off, so the first up/down counter 14
is counted up by the carry signal of the first up-down counter. Therefore, video memory 2 contains normal
,X addressing is performed.

When only the X address reverse command signal is '/'', both data selectors 11 and 12 remain unchanged, but the first Atsuzo down counter 13 counts down and advances the X address in the reverse direction. The signal from the terminal RC of 13 (digit down signal) is sent to the first down counter 13.
count up. Therefore, the fifth state in Table 1 is displayed.

When only the Y address reverse command signal is /'', both data selectors 11 and 12 do not change, the first Atsuzo down counter 13 counts up, and the first down counter 13 counts up by that digit down signal.
The updown counter 13 counts down. This causes the third state of the pyrotechnic to be displayed.

When only the X-Y address progress switching command signal is "/", the seventh and first up-down counters 13 and 14
is in a state of up-counting, but the first and second data selectors 11.12 differ from the normal state in that the input B is connected to the output Y and the input A is turned off. Therefore, the clock signal is passed through the λ-th data selector 12 to the λ-th down count 1. /I is sent to this counter 14
count up. 1st updown counter 1
3, it does not operate according to the clock signal, but counts up according to the carry signal (RC terminal) of the λ-th undercounter 14. As a result, the progression of the Y address is made sequential by the clock signal, and the X address advances by one each time the Y address advances by a predetermined number, thereby achieving the display of the λ-th state in Table 1. From the above explanation, it is clear that
Each command signal 7; 111 is of course 1, and by the combination of these signals, each state in Table 1 is realized by the circuit shown in FIG.

Effects of the Invention According to the present invention, in a rask-scan type graphic display device, a figure can be rotated or reversed without changing the contents of the video memory, and therefore the side view or top view can be easily drawn in an orientation. This is extremely advantageous for drafters.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a graphic display device according to the present invention, and FIG. 2 is a circuit diagram showing an example of address control tτIS. 1...Address control unit, 2...Video memory, 3...
・Display screen, 11, 12...Data selector, ], 3
, 14... Up/down counter. Written amendment (method) 1. Name of the case Patent Application No. 180 of 1980 2, Title of the invention Graphic display device: (, Relationship with the Nell Stopper case) Name of applicant (549) Fuji Xerox Co., Ltd. 4, Agent 5, Assistant i1 - Date of order March 27, 1980, engraving of page 7 of the specification (no change in content).

Claims (1)

[Claims] A display screen, a video memory that stores raster data and outputs predetermined data in response to an address signal to form an image on the display screen, and a clock signal is input to provide an X address signal and an X address signal to the video memory. In the graph ink display device comprising an address control unit, the address control unit includes means for selecting the progression of the X address between successive increase and successive decrease; 1. A graphic display device comprising: means for selecting one of the above, and means for switching the progression of the X address and the progression of the X address.