JPS6250925A - Graphic displaying device - Google Patents

Abstract

PURPOSE:To obtain the graphic displaying device having the control means to be able to cope with the contents of the frame memory by the hardware by providing the means to rewrite the contents of the color look-up table from the higher order and outputting the information of the table to the hard copy. CONSTITUTION:When the back color of the displaying screen is displayed by the blue color, A and B are displayed by the red and C and D are displayed by the green color, the output of a frame memory 10 is executed while a blue dot is 4 (sexadecimal), a red dot is 2 (sexadecimal) and a green dot is 3 (sexadecimal). At such a time, at color look-up tables 41, 42 and 43, the data for red, green and blue and the pattern are respectively written. When the output of the memory 10 is 4 (sexadecimal), red '0000', green '0000', and blue '1111' are outputted, the blue dot is displayed through a D/A converting device 50, and at the time of 2 (sexadecimal), the red dot is displayed and at the time of 3 (sexadecimal), green is displayed. On the other hand, at color hard copy 90 the information of A-D is printed. By the control from the higher order, the color can be changed.

Description

Detailed Description of the Invention [Field of Application of the Invention] The present invention has a frame memory for storing display information in units of dots on a display screen, a color lookup table for determining the display color of the screen, and a notebook copying system. The present invention relates to a graphic display device provided with a drive circuit for use in a computer.

[Background of the invention]

Recently, graphic displays have been frequently used in word processors, personal computers, workstations, etc. (Nikkei Electronics 1982.12.6 issue) FIG. 4 shows a graphic display. The application specifies space-shaped data and a range to be displayed on the display in a logical space segment buffer that the user can directly write to. This content is sequentially read out and subjected to coordinate transformation and clipping processing by a graphics processor. The cut data is then converted into dot information on the screen by a linear generator and written into the frame memory. The contents of this frame memory are passed through a color lookup table that determines the displayed colors on the screen.
Force 2- is displayed on the display. FIG. 5 explains the principle of color display using a frame memory.

Screen information corresponding to the display screen is written as a pit image into the frame memory with codes ``ro'' and ``rlJ''.

Since one frame memory stores the data of one dot hit, four frame memories can display 16 colors using 4 bits and 4 bits, and this combination. Here, it is the color lookup table that determines the actual display color on the screen, and based on this information, the D/A
A converter converts it into an analog signal and sends it to the display as a video signal. FIG. 6 shows a method of connecting 71-tocopies. LBP (laser beam printer)
The signals to a monochrome hard copy are rOJ and rlJ digital signals indicating whether to print or not, and color hard copies are normally sent in seven colors (red, green, spine, yellow, cyan,
For printing (magenta, black), there are three signals for red, green, and spine, and digital signals of "O" and "1" are output from the color lookup table, respectively. This connection method is a video interface that can send data at high speed without imposing a load on software processing, and has therefore become the mainstream hard copy interface for graphic display devices.

By the way, as shown in Fig. 7, recent screen displays have been changed from the conventional one in Fig.
) Instead of displaying figures or characters on a black cathode ray tube surface, as shown in Figure 7(b), positive display, in which information is displayed on a colored background, has become mainstream. . In addition, as shown in FIG. 7(C), multi-windows that control multiple processes on one screen by splitting the screen or controlling multiple displays are becoming popular; in this case, Most of the time, the above-mentioned positive display is used. If this positive display is copied using the conventional method, the background of the monochrome hard copy will also be colored, so the information will be indistinguishable and the result will be pitch black. In addition, in the case of color hard copies, the background color is also copied, making it difficult to see, or if the background color and information color are displayed with different densities of the same color, color... The same problem as black and white may occur.

In order to solve this problem, up until now, when copying, the content of the frame memory has been rewritten using software to erase the background color.

However, in this method, the software processing is time consuming and the overhead is large.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a graphic display device having control means that can control the contents of a frame memory using 71-ware.

[Summary of the invention]

As shown in FIG. 8, the present invention adds a color lookup table for note copying that receives signals from the conventional frame memory, and allows the host to rewrite the contents of this color lookup table. It is characterized by having a control means and outputting the output of this color lookup table as a monochrome hard copy or a color hard copy. This allows the necessary information to be copied correctly by setting the contents on the hard copy color lookup table so that the background color on the CRT is not copied. be able to.

In addition, it is also possible to delete information that does not need to be copied, such as menus, and it is also possible to display the information in a different color from that on the screen, creating a highly flexible graphic display system. can do.

[Embodiments of the invention]

Next, a specific embodiment shown in FIG. 1 will be explained using the display screen and printing example shown in FIG. 2, and the content data example of the color lookup table shown in the M3 diagram. First, the components shown in FIG. 1 will be explained. Reference numeral 10 is a frame memory that stores screen information corresponding to a display screen in the form of a bit image, and is usually constituted by a RAM.

41 is a memory (RAM) that determines the actual display color on the cathode ray tube based on the image information in the frame memory.
It is called an ocal lookup table.

21H is an address changeover switch that normally supplies the frame memory output data to the address input of 41. On the other hand, when rewriting the contents of the color lookup table, it is a switch that switches to the address from the upper host. 1 to perform switching. The rewritten data at this time is supplied to the color lookup table as signal 4. Reference numeral 42 is a memory for determining the printing color of a color hard copy.Similar to 41, an address based on frame memory data is normally called and printing is performed in the color of the content. Further, 22 is an address switch similar to 21 for supplying an address to 42.

Similarly, 43 is a color look-up table for monochrome hard copies, and 23 is its address switch, which has the same function as 42.22. 30 is a timing generation circuit for supplying various overall timings. 5
0 is a D/A converter that creates an analog video signal from the output data of the display color lookup table 41, and also mixes the synchronization timing of the color display 20. Reference numeral 60 denotes a video signal drive circuit for the color hard copy, which mixes the output signal of 42 with the synchronization signal of the color hard copy 90 to create a video signal. 70 is a circuit for the monochrome hard copy 100 similar to 60.

For example, when the display screen shows rAJ rBJ in blue as the background color as shown in Figure 2(a), rCJ in red.
Consider a case where rDJ is displayed in green.

In this case, the output from the frame memory is assumed to be that blue dots are output in (4)□ hexadecimal, red dots in (2)□ hexadecimal, and green dots in (3)□ hexadecimal. At this time, the display color lookup table 41 includes red,
If you write data for green and blue separately, when the frame memory output is (4) and 6, red will be "0000J".
, green 1'-0000J, blue 1'-1111J are output, and when they are D/A converted, a blue dot is displayed and (
2) A red dot is displayed when the number is 16, and (3) a green dot is displayed when the number is 16. Next, a pattern as shown in FIG. 3(b) is written in the hard copy color lookup tables 42 and 43. As a result, when the frame memory output is (2) and 6, the red signal becomes "1", and when the frame memory output is (3) 16, the green signal becomes "1", and each signal is output (
4) When 16, red, green, and blue are all "0", so nothing is output. As a result, A
, B, C, and D information can be printed, and the background color can be omitted. Similarly, the content of 43 is input as (2) 15
and (3) outputs "1" when it is 16, but (4),
When the number is 6, "0" is used, and information can be printed as shown in FIG. 2 (C).

2.3.5 in the figure is a signal.

〔Effect of the invention〕

According to the present invention, the system 1, which does not require any software processing,
Moreover, the image on the screen does not change.

Furthermore, by changing the bit information of the frame memory so that the color used to display information that does not need to be printed, such as a menu, is different from the information that needs to be printed, it is possible to avoid copying the information. Furthermore, the color of the copy can be changed from the display color, making it possible to configure a flexible graphic system.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is a screen and an example of printing, Fig. 3 is a content diagram of a color lookup table, Fig. 4 is a diagram of the display principle of a graphic display, and Fig. 5 60 is a diagram showing the principle of color display using a frame memory, 60th is a conventional hard copy connection configuration diagram, FIG. 7 is a screen display example diagram, and FIG. 8 is a schematic configuration diagram of the present invention. ``'\ v11 Garden 1θ Fig. 2 ((2,) (b) Fig. 3 (gradient (b)) 42 Genfu 4 eyes color 51 blur f 舅5 Nagi SA6 Fig. 70 ￥S8 layer

Claims (1)

[Claims] 1. Using a raster scan type CRT, this CRT
A graphic display device equipped with a frame memory that stores the screen image on the RT in dot units, a color lookup table that determines the display color of each dot based on the output of this frame memory, and a video interface for hard copy output. The color lookup table for determining the print color of the hard copy, a control means for rewriting the contents from a higher level, and outputting the information of the color lookup table to the hard copy. Graphic display device.