JPS606995A - Image display - 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 [Technical Field of the Invention] The present invention relates to an image display device. More specifically, the present invention relates to a cathode ray tube (hereinafter referred to as rcRTJ) type image display device equipped with image memories for the three primary colors of red, green, and blue.

[Technical background of the invention and its problems] As a display device that displays images such as text and images to the human sense of sight, CRT is preferred because of its long lifespan, superior image quality, and relatively low cost. Image display devices are widely used. Furthermore, as the amount of information itself increases and becomes more complex, it is becoming more common to display the information in color to make it as easy to read as possible.

That is, a color image display device separates an image to be displayed into red, green, and blue, which are the 3R colors of light, and stores image data corresponding to each color in an image memory for red, an image memory for green, and an image memory for green. The image is displayed by writing each image into the image memory for blue, specifying the intensity of brightness equalization in correspondence with the pixel value in the image memory, and sending the information to the CRT display section.

On the other hand, when displaying monochrome images on the same image display device, the same image data is written into red, green, and blue image memories. In general, recently, instead of simply displaying an image by a combination of three primary colors, it has become possible to make a particular image easier to see by giving each color a gradation or by switching the display colors. It is being said.

However, for example, when switching from a red image to a blue image, it was necessary to rewrite the image data into the image memory mapped to blue and also specify the gradation corresponding to each pixel. . Furthermore, in order to display natural colors, that is, to express a color-displayed image in black and white, it is necessary to write the same value in the corresponding positions of each image memory for red, green, and blue. These things mean that when the number of pixels that make up a display image increases, but when creating a gradation, the data becomes the most fragile and processing requires a lot of I/O.
This requires time between ISs and a rewriting operation.

An example of a device that quickly changes the display color of a display image is to have a rewritable color register, and to rewrite the contents of the color register without rewriting the color code stored in the refresh memory. For example, JP-A-5
No. 0-140228) is publicly known. However, this method requires as many color designating circuits as the number of colors that can be displayed, and cannot be applied when each pixel has a balanced tone.

[Object of the Invention] The present invention provides an image display device that can quickly change the display color of all or part of a display image having gradations with a simple configuration.

[Summary of the invention] In order to achieve the above object, the present invention uses a CRT
a display section, an image memory that stores image data obtained by dividing image information into the three primary colors of red, green, and blue and digitizing it; and an i! ! (ii) first to third data converters respectively inputting and outputting conversion data such as color brightness corresponding to the image data; and a third data converter which converts output values of the respective data converters into D/A and supplies them to the CRT display unit. 1 to 3rd D/Δ converter, each of the data converters and each D/Δ converter,
a first to third display selection section that selectively connects the A conversion section; a display color selection section that controls each of the display selection sections;
ii! for the image memory! (ii) An image display device comprising an image display control section that controls writing of image data, controls writing of converted data to the data conversion section, and issues control commands to a display selection section.

[Embodiment of the Invention] Hereinafter, an embodiment of an image display device according to the present invention will be described with reference to FIG.

The image display control unit (1) receives image information in the form of a digital sheet sent from an electronic converter or a device similar thereto (not shown);
Second and third image memories (201), (202), (2
Writing image data to 03> and display color selection section (6)
The control 611 is carried out.

The size of the image memories (201), (202), and (203) is determined based on the number of pixels constituting the display image and the gradation scale of each pixel (hereinafter referred to as "video cell"). It does not necessarily have to be physically divided into three parts. The image memory (201), (2) in which image data is written
02>, (203) are accessed under the control of the image display system 1311 section (1), and their outputs are
The data is supplied to the data converter of Here, a so-called lookup table is used as a specific example of the data change (J of the line part). Each lookup table (
301), (302), and (303) are for setting conversion data corresponding to the image data of each picture cell. For example, they are composed of a rewritable memory, and the input data itself serves as an address to set each image data. The data in the table in the memory is read out and this data is used as the output data of the processing result. Lookup table (301).

In steps (302) and (303), table data loading control is performed in the image display control section (1) according to the image processing. In other words, if we use 8pix1~ as the image data representation format for each pixel, we have 256 pixel data.
Although it is possible to express very fine tones, for example, by using a candy whose gradation has been compressed as table data in the first lookup table (301), you can make the displayed image more visible. ＜ Therefore, data conversion that keeps the gradation width within a certain range can be easily performed. The first, second, and third lookup tables (301
).

In (302) and (303), the image data outputted by compressing and converting the gradation, for example, is sent to the first, second, and third display selection units (401) and (402).

(403), respectively.

These display selection sections (401), (40'2), (403
) receives a control signal from the image display control section <1) and is selectively controlled by the display color selection section (6). That is, each display selection section (6) controlled by the display color selection section (6)
401), (402).

(4Q3) is configured with an electric circuit to select which of the first, second, and third lookup tables (301), (302), and (303) to output image data. ing. Further, the output terminal of the first display selection section (401) is connected to the first 1')/A conversion section (501).
), the output terminal of the second display selection section (402>171 output i) is connected to the second (7) CI A conversion section (502), and the output end of the third display selection section (403) is connected to the third D/A conversion section. Part (5
03) respectively. And each D/A converter (501).

The image signals D/A converted by steps (502> and (503)) are supplied to the CRT display section (7).

Next, the operation and effect of FIG. 1 will be explained using a specific example.

First, an example is shown in which an image is displayed in natural colors.

The image information converted into a digital signal is sent to the image display control unit (
1), the first image memory (201), the second image memory (201), the second image memory (201), and the second image memory (201) each receive red, green, and blue color signals with gradations of a constant width. , J (202), third image memory (2
03) are written to the addresses corresponding to each of the BIKUJI↑I- cells. On the other hand, the lookup table (301
), (302).

(303), conversion values corresponding to each image data are written as data in a table under the control of the image display control unit (1), and these conversion data are stored in each image memory (201), <202. .

The signal amount of the image data written in (203> is read out as an address. This lookup table (301
), (302), and (303), the conversion data is
Display selection units (401) and (402>) controlled 2I+ by the display color control unit (6).

After making an appropriate selection using the switching function of (403), the D/A converters (501), (502), and (5)
03) and converts it into an analog signal, the CRT display section (
7).

Even in the case of natural color display, it is possible to perform a display with more rough image processing than the original image information. That is, a lookup table (301).

The table data of <302) and (303) can be freely rewritten by the write control from the image display control unit (1), so the table data of the image memories (201), (202>, (203>)
Instead of uniformly changing the color tone of the image data written to the image data in a straight line, the color tone of the image data within a certain range hardly changes, and the color intensity of image data of a specific value is adjusted in particular. By writing the ZERO J-PULL data, it is possible to display image information more easily.

Next, the operation when displaying image data written in a specific image memory in another color will be explained. now,
When the first image memory (201) is allocated for red color,
The image data written in this image memory <201> is converted into data by a first lookup table (301), and the output is sent to each display selection section (401) and (402).
), n.

3) respectively. Therefore, under the control of the display color selection section (6), the display selection section (/101), (40
2), (403) creates a lookup table (301
), (:302), and (303), the image data in the first image memory (201) can be selectively displayed in either blue or green on the CRT display section (7).

Thus, any image memory (201).

(202) and (203) can also be used by switching without being limited to one of the three primary colors, expanding the range of use of the image memory.

Furthermore, the operation when displaying and covering an image in black and white will be explained. Image memory (201), (202).

(203) contains the same image data, lookup tables (3,01), (302>, (303) contain the same table data as HI, and the lookup table (
301), (302), and (303) respectively]
]/A converters (501), (502>, and (503)), it is possible to display black and white on the (ERT display section (7)).

Also, image memories (201) and (202>).

(203) to each D/Δ conversion unit (501), '(502).

The display selection section (401)
), (402), and (403) can also display the contents of any image memory in black and white.

As described above, display color selection section (6), display selection section (7'1O1), (402), (403) and 1. m thus each lookup table (301).

(302), (303) and D/A converter (501), <
502) and (503), each image memory (201), (202>, (203)
) can be displayed on the CRT display section (7) in any color without being particular about the color of the original image information.

Next, lookup tables (301), (302), (303), D/A conversion units (501), (502>, (,503), and display selection unit (401) of the image display device according to the present invention) , (402).

Another embodiment of the portion (403) will be described with reference to FIG.

In the above embodiment, the switching section is electrical display selection section (401), . . . (402).

<403) has been described, but if the display selection means is a mechanical switch (803) as shown in FIG.
01), (802), and (803) may also be used. The configuration and operation of other parts can be configured in the same manner as in the embodiment shown in FIG. 1, so their explanation will be omitted.

1 Advantages of the Invention 1 In the image display device according to the present invention, the connection between each data conversion unit and the D/Δ conversion unit can be switched at will by the display color selection unit and the display selection unit. Therefore, when displaying image information with gradations on a CRT, display colors and tones can be quickly changed without rewriting the image memory, making the image suitable for remote ranging, etc. Processing is possible.

In general, since the image memory in which image data is written for each bikubuya cell can be used without being limited to one of the three primary colors, the image memory itself can have flexibility.

[Brief explanation of the drawing]

FIG. 1 is a block diagram for explaining one embodiment of an image display device according to the present invention, and FIG. 2 is a block diagram for explaining another embodiment of the display selection section shown in FIG. 1. 1... Image 1 to 1 display control unit 201-203... Image memory 301-303
...Lookup tables 401 to 403...
...Display selection section 501-503...D/A
Conversion section 6...Display color selection section 7...CRT display section

Claims (1)

[Claims] A CRT display unit, an image memory that stores image data obtained by dividing image information into three primary colors of red, green, and blue and converting them into digital data, and converting the brightness, etc. of colors corresponding to the 1ζ image data written in the image memory. first to third data converters that write data respectively; first to third D/Δ converters that D/A convert the output values of the respective data converters and supply them to the CRT display unit; Each data conversion section and each D/
a first to third display selection section that selectively connects the A conversion section; a display color selection section that controls each of the display selection sections;
An image display device comprising an image display control section that controls writing of image data to the image memory, controls writing of converted data to the data conversion section, and issues a control command to a display color selection section.