JPH01287695A - Picture display control system - Google Patents

Abstract

PURPOSE:To increase commonly used parts so as to make the title system economically efficient by causing a selector to select one picture out of plural pictures having different picture constitutions and, at the same time, displaying the selected picture by switching the readout clock signal of a line memory by a clock switching section. CONSTITUTION:The selector 2 selects memories 1-1-1-n for graphic and text having different picture constitutions and supplies read-out displaying data to the line memory 3. At the time of displaying the read-out displaying data, the clock switching section 4 switches readout clock signals so that a high-speed readout clock signal can be used even if the picture constitutions are different from each other, when the horizontal scanning line of the picture constitution is rich in dots, with the writing clock signals and displaying sizes being respectively the same. In addition, a D/A conversion section is commonly used by supplying the displaying data to a display section 5 through the line memory 3. Thus commonly used parts are increased and the economical efficiency of this system can be improved.

Description

[Detailed Description of the Invention] [Summary] Regarding a screen display control method for selectively displaying the screens of Videotex and a personal computer, which have different screen configurations such as the number of dots, an objective is to achieve economy by increasing the number of shared parts. A memory for respectively storing a plurality of pieces of display data having different screen configurations, a selector for adding selected display data from the memory to a line memory, a clock switching section for switching a read clock signal of the line memory; a display section to which display data read out from the line memory is added; the selector selects a plurality of screens having different screen configurations; and the clock switching section switches the read clock signal of the line memory; It was configured to be displayed.

[Industrial application field]

The present invention relates to a screen display control method for selectively displaying Videotex and personal computer screens having different screen configurations such as the number of dots.

Videotex (V1deotex) is capable of displaying information corresponding to user requests, and is known as CAPTAIN in Japan.

Since the contents displayed on the screen in this videotex are not rich, there are multimedia devices that provide a variety of visual options and are controlled in the same way as a personal computer (hereinafter referred to as a "personal computer"). There is a desire to provide such devices economically.

[Conventional technology]

Videotex and PC screen configurations are different, for example, 496x40 as shown by the dotted line in Figure 3.
The screen configuration of 8 dots is Videotex, and the screen configuration of 640 x 400 dots shown by the solid line is that of a normal personal computer.

Therefore, the conventional multimedia device was constructed using a personal computer display board 21 and a videotex display board 22, as shown in FIG. In the figure, 23 is a display section, 24 is a text memory, 25 is a graphic memory, 26 is a synthesis section, 27 is a D/A conversion section, 2
8 is text memory, 29 is graphic memory, 30
31 is a combining section and a D/A converting section.

Display data received by a receiving section (not shown) is stored in a text memory 28 and a graphic memory 29 in the videotex display board 22, and display data read from the text memory 28 by a synthesizing section 30 and a graphic memory 29 are stored. The synthesizer 30 synthesizes the display data read from the display data, and the D/A converter 31 converts the signal into an analog image signal, which is then added to the display 23 .

Also, in the personal computer display board 21, the display data read from the text memory 24 and the graphic memory 25 are synthesized by the synthesis section 26, converted into an analog image signal by the D/A conversion section 27, and then sent to the display section 23. added to. Then, by applying a screen switching signal to the display section 23, the computer screen and the Videotex screen are switched.

The aforementioned personal computer display board 21 has already matured as a program development environment, and the Videotex display board 22 has already been put into practical use exclusively for Videotex. Therefore, by using the image display boards 21 and 22 and inputting a screen switching signal from a keyboard (not shown) or the like, the screen of the display section 23 can be switched. In this case, in order to share the display section 23,
The dot clock signal on the personal computer display board 21 is 23 MHz, and the dot clock signal on the videotex display board 22 is 27 MHz, and the dot clock signal has a speed corresponding to the screen configuration.

[Problem to be solved by the invention]

Conventionally, when displaying the Videotex screen and the computer screen on the same display unit 23, it was necessary to prepare separate display boards 21 and 22 as described above, and almost all of them including memory etc. Since the circuit size is twice as large, it has the disadvantage of being expensive.

The purpose of the present invention is to increase the number of shared parts to achieve economical efficiency.

[Means to solve the problem]

The screen display control method of the present invention is an economical structure by increasing the number of common parts when the screen configurations of Videotex and a personal computer etc. are different.
This will be explained with reference to the figures.

Memories 1-1 to 1-n each storing a plurality of display data with different screen configurations and selected memo+71-1 to 1
-'n includes a selector 2 that adds display data from the line memory 3 to the line memory 3, a clock switching section 4 that switches the read clock signal of the line memory 3, and a display section 5 that adds the display data read from the line memory 3. A selector 2 selects a plurality of screens having different configurations, and a clock switching section 4 switches the read clock signal to be applied to the line memory 3, so that a desired screen is displayed on a display section 5.

[Effect]

The plurality of memories 1-1 to 1-n can be shared even in the case of different screen configurations in the case of bitmap images for graphics, but it is necessary to prepare them for different screen configurations for text. The selector 2 selects graphics and text memories corresponding to different screen configurations and adds the read display data to the line memory 3. In this case, even if the screen configurations are different, if the write clock signal is the same and the display size is the same, a high-speed read clock signal is used if the screen configuration has a large number of dots per horizontal scanning line. As shown, the clock switching unit 4 switches the read clock signal. Also, by adding display data to the display section 5 via the line memory 3,
It is possible to share the D/A converter.

〔Example〕

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

FIG. 2 is a block diagram of an embodiment of the present invention, and 11-1
is a text memory for the personal computer, 11-2 is a graph ink memory shared between the personal computer and Videotex, 11-3 is a text memory for Videotex, and 12
13 is a selector, 13 is a line memory, 14 is a clock switching section, 15 is a display section, 16 is a D/A conversion section, 17 is a switching control section, and except for the display section 15, it is composed of one display board. be able to.

The text memory 11-1, 11-3 and the graphic memory 11-2 each consist of a video random access memory (VRAM) that stores R (red), G (green), and B (blue) display data. , the display data selected by the selector 12 is added to the line memory 13 and written in accordance with a write clock signal from a configuration not shown. Further, display data is read out from the line memory 13 in accordance with a read clock signal applied via the clock switching section 14 and applied to the D/A conversion section 16, where it is converted into an analog image signal and applied to the display section 15.

Since the graphic memory is controlled by a bitmap image, display control can be easily changed. Therefore, even if the screen configurations for personal computers and for Videotex are different, they can be shared. However, since display control of the text memory is performed in units of character font sizes, it cannot be shared if the screen configurations for personal computers and Videotex are different. Therefore, as shown in the figure, only the graphic memory 11-2 is shared by the personal computer and the videotex.

When developing a program, a control signal is applied from the switching control unit 17 to the selector 12 and the clock switching unit 14, and this control signal causes the selector 12 to
and graphic memory 11-2, and read R and G from each.

The display data of B is synthesized and added to the line memory 13.

Further, the clock switching section 14 applies a 27 MHz read clock signal to the line memory 13 and the D/A converting section 16.

Therefore, the R, G, and B display data are read out from the line memory 13 in accordance with the 27 MHz read clock signal, and the D
The signal is converted into R, G, and B analog signals by the /A conversion section 16 and added to the display section 15, where a program development screen is displayed at a predetermined display size.

In addition, when displaying videotex, the switching control section 17
In response to a control signal from
-3, the R, G, and B display data read from each are combined and added to the line memory 13, and the clock switching unit 14 switches to a 23 MHz read clock signal and performs D/A conversion with the line memory 13. Add to section 16. Therefore, R, G, and B display data are read from the line memory 13 according to the 23 MHz read clock signal, and the D/A
The conversion unit 16 converts the signal into R, G, and B analog signals and adds them to the display unit 15, where the videotex screen is displayed at the same display size as in the case of program development. In this case, unless the readout clock signal is switched, the videotex screen will be displayed on the display section 15 at a reduced display size.

Although the above-mentioned embodiments are shown for cases in which the screen configurations for a personal computer and for Videotex are different, the present invention can also be applied to cases in which screens having different screen configurations are switched and displayed.

〔Effect of the invention〕

As explained above, in the present invention, the selector 2 selects the memories 1-1 to 1-n that respectively store a plurality of display data with different screen configurations such as those for personal computers and Videotex, and displays the display data on a line. In addition to the display unit 5 via the memory 3, the readout clock signal of the line memory 3 is switched by the clock switching unit 4 according to the screen configuration, and a plurality of memories 1-1 to 1-n are selected by the selector 2. By doing so, it is possible to include the line memory 3 on one display board, and by adding display data to the display unit 5 via the line memory 3, it is possible to convert the display data into an analog signal. It is possible to share the D/A conversion section of the display section 5 and to simplify the connection configuration between the display section 5 and the display section 5. Furthermore, by switching the readout clock signal of the line memory 3, it is possible to display the image on the display section 5 at a predetermined display speed. Also, like a graphic memory, the memory for dot map images can be shared, so the memory configuration can be simplified. Therefore, there is an advantage that the structure can be made economical.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the principle of the present invention, FIG. 2 is a block diagram of an embodiment of the present invention, FIG. 3 is an explanatory diagram of a screen, and FIG. 4 is a block diagram of main parts of a conventional example. 1-1 to 1-n are memories, 2 is one selector, 3 is a line memory, 4 is a clock switching section, 5 is a display section, 11-1 is a text memory, 11-2 is a graphic memory, 11
-3 is a videotex text memory, 12 is a selector, 13 is a line memory, 14 is a clock switching unit, 15
16 is a display section, 16 is a D/A conversion section, and 17 is a switching control section.

Claims (1)

[Scope of Claims] Memories (1-1 to 1-n) each storing a plurality of display data having different screen configurations, and a line memory for storing display data from the selected memories (1-1 to 1-n). (3); a clock switching section (4) for switching the read clock signal of the line memory (3); and a display section (5) for adding the display data read from the line memory (3). The selector (2) selects the plurality of screens having different screen configurations.
and switching the read clock signal of the line memory (3) by the clock switching unit (4),
A screen display control method characterized by displaying on the display section (5).