JPH1011048A - Image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily switch displays before and after composition by altering data of a color conversion table, and making an OR display or sprite display and putting together and displaying >=2 kinds of color data. SOLUTION: When a display state is changed to a composite screen, the contents of a look-up table(LUT) 5 are altered. This alteration is made with an instruction of a CPU 1, which constitutes a means for altering the data of the color conversion data table. Namely, the CPU 1 alters color data of the LUT 5 corresponding to color codes drawn in respective areas. Consequently, a circular area and a beltlike area are displayed in different colors and the state of the composite screen is entered. Thus, the contents of a frame memory 4 are not changed and the color data of the LUT 5 are altered to make what is called the sprite display wherein the image in an area inside the external edge of an image is hidden when an image is superimposed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image display control device for reading out image data stored in a frame memory and displaying the image data on a display device such as a CRT or LCD in multiple colors and multiple gradations.

[0002]

2. Description of the Related Art As a display device for performing color display and multi-gradation display, image data is read from a frame memory of a parallel data input / output system, and characters are displayed on a display unit such as a CRT (cathode ray tube) or LCD (liquid crystal display device). There is a graphic display device (hereinafter, simply referred to as “display device”) for displaying image information such as images and patterns. One example of such a display device is shown in FIG. The display device according to the conventional example includes a CPU 1 that controls the entire device and between components, an LCD (liquid crystal display device) 2 that displays an image, and an LC that executes display control of the LCD 2.
DC (LCD controller) 3, frame memory 4 for storing image information, LUT (look-up table) 5 for performing image conversion, ROM 6 storing fixed information such as programs for CPU 1, and work area for CPU 1. , And is basically composed of elements of the RAM 7 in which data to be processed and the like are stored.

[0003] In the display device composed of such elements, the LCDC 4 operates as follows.

First, the CPU 1 stores in each register in the LCDC 4 a display start address (start address) on the frame memory 4, the number of characters to be displayed on the LCD screen in the horizontal direction (horizontal display screen width), and the number of characters to be written in the frame memory 4 in the horizontal direction. (Horizontal virtual screen width) etc. are set. The CPU 1 draws display data on the frame memory 4, and the LCDC 3 sequentially reads out the contents of the frame memory 4 in accordance with the above settings, converts the contents into serial data by the parallel-to-serial conversion circuit 8, and then outputs the data to the LCD via the LUT 5.
Transfer to 2. In FIG. 1, the frame memory 4 is divided into six color planes 4a to 4f. The illustrated state means that one pixel can be simply represented by 6 bits, and here, these 6 bits are called a color code.
In this example, LUT5 for a 6-bit color code
Is converted to 18-bit color data. LUT5
LUT for 6-bit color code input to
The color data set to 5 is transferred to the LCD 2.
Here, although the pixels are represented by a 6-bit color code, it goes without saying that gradation may be introduced instead of color.

As described above, the six color planes 4a to 4a
FIG. 5 (C),
In the case where the display is changed (combined) as shown in (D), a method of simply rewriting data as disclosed in JP-A-3-188572, a method disclosed in JP-A-4-156496, JP-A-4-1564
No. 97 and Japanese Unexamined Patent Application Publication No. 2-2855397, a method of providing a plane for overlay and mask data, and fixing a vertical relationship as disclosed in Japanese Unexamined Patent Application Publication No. 2-293792. There are known a method of erasing a background, a method of alternately displaying two image data for each frame as disclosed in Japanese Patent Application Laid-Open No. 3-45994, and the like.

[0006]

By the way, in the above-mentioned method, since the data before the synthesis is lost, the process becomes enormous when the display is restored. Moreover,
Since all the processing is performed by software, the processing time becomes longer. In addition, the display is difficult to see when performing blink display.

In the above method, since mask data needs to be set in addition to display data, an extra memory capacity is required and the cost is increased.

In the method described above, different display data is sprite-displayed on the background, so that the vertical relationship of the display data cannot be freely changed.

In the method shown in FIG. 5,
(D) can be displayed, but (C) cannot be displayed. That is, only the OR display can be supported.

This is because, for example, in the composite display as shown in FIG. 5, when (A) and (C) are alternately blink-displayed, the display is switched to another area in the frame memory in advance in view of the speed at which the display is switched. It is desirable that the image shown in FIG. 5A and the image shown in FIG. 5B be drawn and turned on / off by hardware sprite processing.

The present invention has been made in view of such a conventional situation, and a first object of the present invention is to provide an image display control device capable of easily switching between display before and after combination. Is to do.

It is a second object of the present invention to easily change the display mode by instantaneously switching the display between before and after the synthesis and improve the software development efficiency.

[0013]

In order to achieve the first object, the first means is capable of multi-color display, in which bits constituting a color code of each pixel are constituted by a plurality of color planes. In an image display device that performs color conversion using a color conversion table, two or more types of display are performed by changing the data of the color conversion table and performing OR display or sprite display without changing the written contents of the color plane. It is characterized in that color data is synthesized and displayed.

In order to achieve the second object, the second means is capable of multicolor display, wherein a bit constituting a color code of each pixel is composed of a plurality of color planes, and a color conversion table In the image display device for performing conversion, a plurality of the color conversion tables are provided, and by switching the plurality of color conversion tables, the OR of the written contents of the color plane and the data written in the color conversion table are not changed. Display or sprite display is performed to synthesize and display two or more types of color data.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

The image display device itself has the same configuration as the image display device shown in FIG. 1 described above, and a description thereof will be omitted.

FIG. 2 is an explanatory view showing a state when the composite data is drawn on the logical space of the frame memory 4, and FIG.
It is an example of data stored in the UT.

First, the aforementioned color code is drawn in each of the divided areas (a) to (f) as shown in FIG. The content of the color code is as shown in FIG. For example, when only the square shown in FIG. 5A is displayed as the display before the synthesis, the converted data in the LUT 5 is drawn in the areas of (a), (b), and (e) as shown in FIG. The same color data is set for the color code 01 (hereinafter, the color code and the color data are represented by hexadecimal numbers), 02, and 05. Similarly, (c),
Color code 0 drawn in areas (d) and (f)
The color data corresponding to 3, 04, 06 is set to the same setting. With such settings, (a), (b),
The rectangle combining the areas of (e) is color data 00,
30, 0F, and other colors (c),
Areas (d) and (f) are color data F0, F0, F
It is displayed in the color 0.

When changing from such a display state to the composite screen (C) of FIG. 5, the contents of the LUT 5 are changed as shown in FIG. This change is performed according to an instruction from the CPU 1, and in this embodiment, the CPU 1 constitutes means for changing the data of the color conversion data table. That is,
The CPU 1 changes the color data of the LUT 5 corresponding to the color codes 02 and 03 drawn in the areas (b) and (c) to 85, 46 and A0, and is drawn in the areas (d) and (e). The color data corresponding to the color codes 04 and 05 is changed to 00, FF and 00. As a result, the circular areas (b) and (c) and the band-shaped areas (d) and (e) are displayed in different colors, and the state of the composite screen (C) in FIG. 5 is obtained. By changing the color data of the look-up table 5 without changing the contents of the frame memory 4 in this manner, the color image shown in FIG.
When the image of FIG. 5B is superimposed, a so-called sprite display in which an image in an area inside the outer edge of the image of FIG. 5B is hidden can be easily performed.

When changing to the composite screen (D) shown in FIG. 5, the color data corresponding to the color codes 02 and 03 drawn in the areas (b) and (c) are not changed, and (d) and ( Color code 0 drawn in area e)
The color data corresponding to 4, 05 may be changed to 00, FF, 00. Also in this case, by changing the color data of the lookup table 5 without changing the contents of the frame memory 4, when the image of FIG. 5B is superimposed on the image of FIG. The image in the region inside the inner edge of the image in FIG. 5B is displayed, and the so-called OR display in which only the overlapping portion of the image in FIG. 5B is displayed on the image in FIG. I can do it.

FIG. 4 is a block diagram showing another embodiment.
A configuration in which a color conversion mode register 9 is provided and a display mode is changed using the register 9 will be described.

That is, in the above-described embodiment, the data in the LUT 5 is rewritten. However, a plurality of conversion tables such as the data before synthesis and the data after synthesis shown in FIG. The CPU 1 selects a conversion table suitable for the display state to be set by setting the conversion table in the color conversion mode register 9. As a result, the CPU 1 only needs to set the mode in the color conversion mode register 9, so that it is not necessary to rewrite the contents of the LUT 5 by the CPU 1 as in the embodiment (FIG. 1).

Each control in each of the above embodiments is based on a program written in the ROM 6 based on the CP.
U1 executes.

[0024]

As described above, according to the first aspect of the present invention, the OR display or the sprite display is performed by changing the data of the color conversion table without changing the writing contents of the color plane. Since two or more types of color data are combined and displayed, switching between display before and after combination can be easily controlled.

According to the second aspect of the present invention, a plurality of color conversion tables are provided, and the contents written in the color plane and the data written in the color conversion tables are changed by switching the plurality of color conversion tables. No O
Since R display or sprite display is performed and two or more types of color data are synthesized and displayed, switching between the display before and after the synthesis can be instantaneously realized by switching the color conversion table. Changes can be made easily, and the efficiency of software development for image display can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of an image display device according to a conventional example and a first embodiment.

FIG. 2 is an explanatory diagram showing drawing contents of a frame memory in FIG. 1;

FIG. 3 is an explanatory diagram showing an example of setting of data stored in a lookup table.

FIG. 4 is a block diagram illustrating a schematic configuration of an image display device according to a second embodiment.

FIG. 5 is an explanatory diagram showing a display example in which colors are classified for each area.

[Explanation of symbols]

 1 CPU 2 LCD (Liquid Crystal Display) 3 LCDC (LCD Controller) 4 Frame Memory 5 LUT (Look Up Table) 6 ROM 7 RAM 8 Parallel-Serial Conversion Circuit 9 Color Conversion Mode Register

Claims (2)

[Claims] 1. An image display device capable of multicolor display, wherein bits constituting a color code of each pixel are constituted by a plurality of color planes, and perform color conversion by a color conversion table. Means for changing the data by the means to perform an OR display or a sprite display without changing the written contents of the color plane to synthesize and display two or more types of color data. Characteristic image display device. 2. An image display device capable of multicolor display, wherein bits constituting a color code of each pixel are constituted by a plurality of color planes, and perform color conversion by a color conversion table. And a means for switching between the plurality of color conversion tables, and by switching the color conversion tables by the means, an OR display without changing the written content of the color plane and the data written in the color conversion table. Alternatively, an image display apparatus that performs sprite display to synthesize and display two or more types of color data.