JPH0241672Y2 - - Google Patents

Description

[Detailed description of the invention] A. Field of industrial application This invention aims to improve the operability of image production for video display devices using CRTs and light pens, especially those having pattern memory, pattern color memory, and background color memory. This invention relates to a video display device.

B. Prior Art Figure 1 shows the configuration of an existing CRT-based video display device. In the figure, 1 is a synchronization signal generation circuit, 2 is a CRT, 3 is an address counter, 4 is an image memory, 5 is a light pen, 6 is a latch circuit, and 7
8 is a coloring control circuit, 8 is an A/D conversion circuit, and 9 is a write data control circuit.

In such a configuration, the clock φc is input to the synchronization signal generation circuit 1, and the synchronization signal generation circuit 1 outputs a horizontal synchronization signal H and a vertical synchronization signal V, respectively.
The horizontal synchronizing signal H and vertical synchronizing signal V drive the CRT2.

The clock φc is input to the address counter 3 and outputs an address signal for the image memory 4.
The address signal is the CRT indicated by the light pen 5.
It is also input to the latch circuit 6 to detect the address corresponding to the coordinates of the two screens.

The data output from the image memory 4 passes through a readout control circuit 7 that controls image coloring.
It is input to the D/A converter 8 and becomes an analog signal.
Displayed on the CRT2 screen.

The light pen 5 outputs a bright line detection signal 1 and a light pen switch signal ls that turns ON when the light pen 5 presses the screen of the CRT 2, and thereby the latch circuit 6 latches the output of the address counter 3. Therefore, the output of the address counter 3 latched by the latch circuit 6 corresponds to the coordinate position on the screen of the CRT 2 indicated by the light pen 5, and is input to the write data control circuit 9.
Image data in the image memory 4 corresponding to the address position (coordinate position) is rewritten, and various commands corresponding to the address position are executed. Here, a microcomputer system using a microprocessor as the CPU is often applied to the write data control circuit 9. Examples of video display devices with such a configuration include Sanyo Electric Technical Report, Vol.
13, No. 1, Feb. 1981, P11-14.

On the other hand, the image memory 4 is composed of a pattern memory 10, a pattern color memory 11, a background color memory 12, and a raster color memory 13, as shown in FIG. The pattern memory 10 is, so to speak, a positive film for monochrome photographs, and is used as volatility information.
Displayed on CRT2. This pattern memory 10
The coloring data of the portion where the image data becomes logic "1" and characters and figures are actually written is stored in the pattern color memory 11. Further, the image data in the pattern memory 10 is a logic "0", that is, the coloring data of the portion where no characters or figures are written is stored in the background color memory 12. If the coloring data of the pattern color memory 11 and the background color memory 12 match for a logic "0" in the pattern memory 10 and that part corresponds to that part, the data of the raster color memory 13 will be displayed on the screen of the CRT 2. The color will be displayed according to the color. pattern memory 1
The number of pixels of 0 matches the capacity of the pattern color memory 11 and the background color memory 12, but as for the raster color, of course, one data (one color) is sufficient for one screen.

The readout control circuit 14 controls the pattern data, pattern color data, background color data, and raster color data from the image memory 4 according to the logic described above. As shown in the figure. A first selection circuit 19 for background color and raster color is formed by AND15, AND16, inverter 17, and OR18. A matching circuit 20 checks whether the data of the pattern color and the background color match/mismatch. If the pattern color and background color match, the raster color is output from the selection circuit 19. Second
The selection circuit 21 is AND3, 22, AND4, 23,
It is formed by inverters 2, 24, OR2, 25, and selects and decides whether to output a pattern color or a background color based on pattern data.

Problems with the above configuration are as described below. For example, consider two cases as shown in FIG. That is, (a) the character "3" is written in the pattern memory 10, the pattern color memory 11 contains color data for all green, and the background color memory 12 contains color data for all white.

(b) The pattern memory 10 contains pattern data inverted from that in (a), the pattern color memory 11 contains color data for all white, and the background color memory 12 contains color data for all green.

These two states are exactly the same on the CRT2 screen and cannot be distinguished. Therefore, when changing the coloring later, the user is confused as to whether the displayed color is the pattern color or the background color.
The only way to determine this was to actually create a color change operation and judge based on the results.

C. Purpose of the invention The present invention provides an image display device with the following features:
The purpose is to add a function to display only pattern data on the CRT2 screen to make it easier to distinguish between pattern color and background color.

D. Structure of the invention The present invention attaches a color data cutoff switch to the pattern color data and background color data input of the readout control circuit 14, cuts off the original pattern color data and background color, and replaces the pattern color data and background color data. It gives the same data to both.

E. Embodiment FIG. 5 shows an embodiment of the present invention. The present invention is applied to a read control circuit, and the other configurations are the same as those shown in FIGS. 1 and 3, so a description thereof will be omitted. The feature of this invention is that color data cutoff switches SW1 and SW2 are provided which are linked to the pattern color data input terminal and the background color data input terminal.
2, constant color data is input to the readout control circuit 14. In other words, these switch SW
Normally, the A side contacts of SW1 and SW2 are closed, and the contents of the pattern color memory 11 and background color memory 12 are input to the readout control circuit 14.

When changing the color of characters and figures displayed on the CRT2 screen, switch SW1 and SW2 to the B contact side. At this time, matching constant data is input as the pattern color data and the background color data. Therefore, on the CRT 2 screen, the part where the content of the pattern memory 10 is logic "1" is B.
Coloring is performed in accordance with certain data input to the contact side, and on the other hand, a raster color is displayed in a portion where the content of the pattern memory 10 is logic "0".
Therefore, the logic "1" and logic "0" portions of the pattern memory 10 can be confirmed, and as a result, it is possible to easily determine whether the color on the CRT 2 screen is a pattern color or a background color.

F. Effect of the invention As is clear from the above explanation, this invention merely adds a simple switch, which was difficult to do in the past.
It becomes extremely easy to distinguish pattern colors and background colors.
The practical effects are significant.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing the configuration of a conventional video display device, Figure 2 is a conceptual diagram showing the configuration of the image memory unit, Figure 3 is a block diagram of the internal configuration of the readout control unit, and Figure 4 is a pattern color diagram. FIG. 5 is a block diagram showing the configuration of the readout control section used in the present invention;
CRT, 4 is image memory, 7 is coloring control circuit, 9
14 is a write data control circuit, 14 is a read control circuit, 19 and 21 are selection circuits, and SW is a color data cutoff switch.

Claims (1)

[Claims for Utility Model Registration] Pattern information storage means, pattern color storage means, background color storage means, raster color storage means, readout control means for reading out the contents of each of these storage means, and said readout control a display means for displaying the contents read out by the means, and a color signal cutoff for blocking the output of each storage means between the pattern color storage means and background color storage means and the readout control means. A video display device characterized by being provided with a means.