JPH02156292A - Display controller - Google Patents

Abstract

PURPOSE:To contrive the improvement of accuracy of a display control by replacing to a combination of easily visible colors by providing a switching circuit for switching a first color register to a second color register at the time of a gradation display, etc., and a designating a color of a character, etc., displayed on a display device. CONSTITUTION:The display controller is provided with a first color register, a second color register 2 and a switching circuit 3. A second color register 2 stores color data of a combination of each color in which a gradation level has a comparatively large difference, by which a color displayed on a display device 9 can be discriminated easily. The switching circuit 3 switches a first color register to a second register 2 at the time of a gradation display, and executes an operation for designating a color of a character, etc. displayed on the display device 9. In such a way, a difference of gradation levels of the display contents can be set large, and the color can be discriminated easily.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a display control device for a scanning display device that displays information such as characters.

[Conventional technology]

FIG. 2 is a block diagram showing the configuration of a conventional display control device. In the figure, 4 is a refresh memory that stores data to be displayed on the scanning display device 9, and is normally connected to a computer (not shown) that controls this display control device through an interface circuit (not shown). The contents can be freely rewritten according to the computer program. Reference numeral 5 denotes a character font memory which receives character codes to be displayed on the display device 9 from among the data from the refresh memory 4 and outputs the character stamp data. This memory 5 may be a fixed memory such as an EPROM, or may be a random access memory such as a refresh memory. 6 is a shift register for outputting the character font data from the character font memory 5 in scanning order. Further, reference numeral 1 denotes a first memory for storing color data for specifying the color of characters to be displayed on the display device 9 based on data from the refresh memory 4.
The color register outputs the color data for each character. 8
is an output circuit that combines the bit output of the shift register 6 and the color data of the color register 1. Further, 7 is a timing control circuit that outputs various timing signals for controlling the circuits within these display control devices.

Next, the operation will be explained. FIG. 3 is a simplified timing diagram for understanding the operation of the second block diagram. The dot data of A shown in the output dot in FIG. 3 corresponds to one character in one scanning line of characters to be displayed, and as shown in FIG.
By appearing n+2+..., n+7, for example, a character of 8 dots x 8 dots is displayed. In order to output this part A, a refresh memory address is output from the timing control circuit 7 in FIG. 2 to the refresh memory 4 in accordance with the output reference clock.

The refresh memory 4 receives this refresh memory address and outputs the character data and character code to be displayed to the character font memory 5 and the color register selection data to the color register 1 as a refresh memory output signal. , refresh memory 40
The timing control circuit 7 receives the character code output signal and also receives the character code output signal.
It receives an address value as scanning line information from and outputs character output data. The shift register 6 receives character output data from the character font memory 5, receives the shift register latch signal shown in FIG. Output. On the other hand, the color register 1 receives color register selection data from the refresh memory 4 and outputs the output signal of the designated color register 1 to the output circuit 8.

The output signal of color register 1 is at least three primary colors red, green,
Three bits of blue are normally present. Output time 1? a8
A simple example of this is shown in Figure 5, where the color register l
If the display device 9 is a color CRT, for example, it receives the display data from the output circuit 8. , a synchronization signal is received from the timing control circuit 7, and a color CRT display is realized.

[Problem to be solved by the invention]

Now, the basic operation of the display control device of a scanning display device has been explained above, but in recent years, the development of software and hardware for small computers has been remarkable, and a large amount of useful software has been developed. A new display device called a display panel, which is used in small computers such as the so-called Tsubu personal computer, is also becoming popular. However, the quality of display panels is still immature compared to CRTs, colorization is still in the development stage, and the cost is high.Currently, it is best to display color data as black and white or in shades of gray in between. There are two methods. The method to express this color in black and white is to use the color data red from color register 1,
Assuming that green and blue are R2O and B, it is conceivable to provide the output circuit 8 with a circuit that converts R, G, and B into gray levels as shown in FIG. 6, for example.

By the way, when running application software with color CRT in mind in such a small computer with black and white gradation display, RG is especially
There are problems in that it is difficult to see (or distinguish between) colors that have similar numerical values in the B bit configuration.

This invention was made in order to solve the above-mentioned problems. The purpose is to provide equipment.

[Means to solve the problem]

The display control device according to the present invention includes a second color register 2 that stores color data of combinations of colors having relatively large differences in gray level to be displayed on the display device 9, and a first color register 2 for storing color data of combinations of colors having relatively large differences in gray level to be displayed on the display device 9; from color register l to second color register 2
The present invention is characterized in that it includes a switching circuit 3 for specifying the color of characters, etc. to be displayed on the display device 9.

[Effect]

In this display control device, the second color register 2 stores color data of a combination of colors that are easily distinguishable and have a relatively large difference in shading level to be displayed on the display device 9, and the switching circuit 3 At the time of shading display, the first color register 1 is switched to the second color register 2, and the operation for specifying the color of characters, etc. to be displayed on the display device 9 is performed, so it is possible to set a large difference in the shading level of the displayed content. .

[Embodiments of the invention]

FIG. 1 is a block diagram showing the configuration of a display control device according to an embodiment of the present invention. In FIG. 1, components corresponding to those shown in FIG. 2 are designated by the same reference numerals, and their explanations will be omitted. In FIG. 1, 2 is a display device 9
Combination color data of colors that are easy to distinguish, that is, combinations of colors whose shading levels are close to each other, versus combinations of colors whose shading levels have a relatively large difference? >A second color register 3 stores the replaced color data, and is used to switch from the first color register 1 to the second color register 2 during gradation display, etc., and specify the color of characters, etc. to be displayed on the display device 9. This is a switching circuit. This switching circuit 3
performs a switching operation in response to a switching signal lO output from a programmable register (not shown).

Now, in an application program running on a display control device as shown in Figures 2 and 1, various characters, their display colors, etc. are set by the program in each register of the display control device, or by the system. These registers are set through a program, and even if the registers are set in advance before running this application program, the registers are generally set newly by the application program and cannot be changed. It is.

Under such circumstances, when an application program for color display is displayed in black and white and a density intermediate between the ratios as shown in FIG. 6, for example, depending on the settings of the program, the level of shading may become difficult to see. In such a case, before running this application program, use another software to enter a combination of easily distinguishable colors into the second color register 2 shown in FIG. Set it to select.

When this application program is executed after that, this application program writes the color output signals of all characters to the first color register 1 and operates as if it had output them, but in reality, The output signal of the refresh memory 4 is manually input to the first color register l and the second color register 2, and each color data is output. is selected, and as a result, the color data in the second color register 2 is output to the output circuit 8.
and finally output to the display device 9.

Here, regarding the second color register 2 and its switching signal source register in the block diagram of FIG.
Since it is not accessed by an application program created for the display control device shown in the block diagram, it is not rewritten by this program and the display does not change midway.

In this way, in the conventional display control device shown in FIG. 2, the application program sets the first color register 1;
In this embodiment, the color data of the second color register 2 set in advance is actually output, and an easy-to-read display is realized.

Although the color of each character has been explained in the embodiment shown in FIG. Even in a display control device in which the color changes dot by dot, the same effect can be obtained as long as the coloring is done through the color register. In addition, in the case of character units, there are some that color both the character part and the back shadow of the character, but even in such cases, it is sufficient to change the color in units of display dots, and the same effect can be obtained in this case as well.

As described above, according to the above embodiment, the second color register 2 is used by the computer software according to the user's will, and the color data of this second color register 2 is also used by the computer software according to the user's will. Changed through. As a result, for application software that makes it difficult to distinguish between colors due to shading of the color display,
Depending on the user's will, the color data can be converted to make it easier to see the distinction between colors.

〔Effect of the invention〕

As described above, according to the present invention, the second color register stores the combination color data of colors with relatively large shading levels, which makes it easy to distinguish between colors displayed on a display device;
Since the configuration includes a switching circuit for switching from the first color register to the second color register to specify the color of characters, etc. to be displayed on the display device when displaying shading, etc., depending on the application software, it may be displayed in shading. It is possible to replace color combinations that are difficult to see with color combinations that are easy to see. There is no need to recreate the display for black and white display, and the effect of improving the accuracy of display control can be obtained.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a block diagram showing the configuration of a display control device according to an embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of a conventional display control device, and FIG. 3 is a block diagram showing the configuration of a conventional display control device. 2 is a timing diagram for explaining the operation of the conventional example, FIG. 4 is a signal waveform diagram for explaining the dot data of scanned characters in this embodiment and the conventional example, and FIG. 5 is a timing diagram for explaining the operation of the conventional example. FIG. 6 is a block diagram showing an example of the output circuit shown in the figure. FIG. 6 is a diagram showing the display ratio of RGB output colors and shading of monochrome intermediate shading colors in this embodiment and the conventional example. l...First color register, 2...Second color register, 3...Linkage circuit, 4...Refresh memory, 7
...Timing control circuit.

Claims (1)

[Claims] a refresh memory for storing data to be displayed on the display device; a first color register for storing color data for specifying the color of characters, etc. to be displayed on the display device according to the data from the refresh memory; In a display control device that includes a display device, the refresh memory, and a timing control circuit that outputs various timing signals for controlling the first color register, etc., a display control device is configured to adjust the gray level for combinations of colors with close gray levels. a second color register that stores color data replaced with a combination of colors having relatively large differences in level;
A display control device comprising: a switching circuit for switching from the first color register to the second color register to designate the color of characters, etc. to be displayed on the display device during grayscale display.