JPS63118787A - Superimposition display system - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to displays on computer displays, and particularly to a method for superimposing digital information and analog information.

[Conventional technology]

In workstations, a so-called multi-window system has been adopted in which multiple terminal images are displayed on one display as if there were multiple terminals. The conventional multi-window is, for example, "Nikkei Electronics J Tao 374 (July 29, 1985)
As discussed on pages 141 to 161 of the Japanese issue, digital information was superimposed and displayed on a display. However, there is a demand for displaying not only digital information but also analog information (moving image information) from video devices such as televisions, video tape recorders, video discs, and video cameras as one window of a multi-window.

FIG. 2 shows an example of a display screen of a workstation. On the display 1, there are a plurality of rectangular areas called windows. The position, size, vertical function, etc. of the window can be changed freely according to the operator's instructions.For example, the window 22 is located below the window 21 and above the window 23 in FIG. 2, but in FIG.
Windows 21.23 are above both.

Now, the first conventional method for zero superimposition in which video information is displayed in the window 22 is to use the level of an analog signal.

In FIG. 4, a video device 2 generates an analog video signal. However, in this example, for the sake of synchronization with digital information, the analog signal is first converted to digital and then passed through the D/A converter 4, which performs digital-to-analog signal conversion, to generate an analog signal. On the other hand, the computer 3 generates a digital signal, which is converted into an analog signal by the D/A converter 5.

A signal from the computer is given to the terminal i of the comparator 8, and a preset threshold is given to the terminal t, so that the level of i is higher than the level of t, that is, 1evel (i) > 1
evel(t), the output of comparator 8 is “1
”, otherwise the output is “0”.

Switches 6 and 7 have an analog human input i and a digital input for control, and when input C is "1", input i is output as is, and when input C is "0".

The output will be open.

When the input i from the computer 3 to the comparator 8 is higher than the threshold t, the input C of the switch 7 becomes "1", and the input from the computer becomes the output of the switch 7 and is given to the display 1. At this time, the output of the comparator 8 is inverted by the inverter 9 and applied to the switch 6. Therefore, the input C of the switch 6 becomes "0", and the video device 2
The output from is not output to the display.

On the other hand, when the input i from the computer 3 to the comparator 8 is lower than the threshold t, the output of the comparator 8 becomes rOJ,
Display 1 is provided with only the output from the video device.

As explained above, according to the first conventional method.

Either the computer output or the video output is selectively displayed depending on the threshold and the output level from the computer6.
For example, in FIG. 2, if the window 22 is displayed in black (lowest signal level), information from the video device will be displayed in the area of the window 22.

As a second conventional method, there is a method in which an area in which video information is to be displayed is indicated by a rectangle, and video information is displayed within the area, and information from a computer is displayed outside the area. That is, selection display is performed based on the address.

[Problem that the invention seeks to solve]

However, the problem with the above-mentioned first conventional method is as follows.

Video information is displayed in places where the output level from the computer is low (places where video information should not be displayed). For example, in FIG. 2, if the frames of windows 21 and 23 correspond to the blackboard area, video information will also be displayed in this area. That is, the colors that can be used on the computer side are severely restricted, and blackish colors cannot be used. The second problem is that the display becomes unstable because analog levels are used.

In places with intermediate levels, video information is displayed in some cases, and information from a computer is displayed in other cases.

On the other hand, according to the second method, there are no restrictions on the colors used by the computer, and the display does not become unstable.However, in this method, the video display area is limited to a rectangle, and the second method
It is difficult to use an overlapping area like the window 22 in the figure as a video display area.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a superimposed display method that has no restrictions on the colors that can be used on the computer side, provides stable display, and can display video information in any shape, not just rectangles. It is about providing.

[Means for solving problems]

In order to achieve the above object, the present invention displays video information if the content of digital information output from a computer has a specific value, and displays information from the computer if the content is other than that.

[Operation] In the present invention, video information/digital information is selectively displayed according to the content of digital information output from a computer. Of the information output from the computer, you can selectively display video information by setting a specific pattern (color) only where you want it to be displayed. In the present invention, since the display content is selected using a digital pattern, the display does not become unstable, and video information can be displayed in any shape by writing a preset location on the computer side.

Also, if one dot is represented by n bits, then 2''
Colors can be displayed at the same time, and only one color is disabled, so restrictions on color usage are loose.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

Video equipment 1 such as video tape recorder, video camera, etc.
The analog information (composite video signal) output from 0 is converted into R (red) and G (green) by a synchronization separation circuit (not shown).

The signal is separated into B (blue) color signals, converted into digital signals by an A/D converter, and then stored in the video memory 12. CRT controller CRTC1 controlled by clock 11
R, G, and B video information is read out separately from the video memory 12 using address signals and timing signals output from the video memory 12.

After supplying this to the D/A converter 4 and converting it into an analog signal, the analog switch 19 (19a).

19b, 19c). On the other hand, on the computer side, one display content is stored in the frame memory 13. A specific pattern is written in the video display area. The content read by the CRTC 15 is the color palette number corresponding to each dot. This number is compared with the number set in the video color register 17 by a comparator 18, and if they match, the comparator output becomes "1", and if they do not match, it becomes "0".

The data read from the memory is converted into RGB color signals using the palette 16. Each of them is converted into analog information by a D/A converter 5, and is converted into analog information by an analog switch 19.
is supplied to the input terminal it.

The analog switch 19 has two analog inputs 11, i
t and control input C, and if control input C is "1", it,
If it is rOJ, it is a switch element that outputs 12 as is. In this manner, video information/digital information is selected and displayed on the display 1 according to the output contents of the computer side, that is, the contents of the frame memory 13. Delay element 2
0 adjusts the time required for the data read from the frame memory 13 to be converted by the palette 16 and the D/A converter 5, and the time required for comparison by the comparator 18, and adjusts the selection timing of 1 display data. Used to match.

In the above embodiment, a method was explained in which video information is A/D converted and then temporarily stored in the video memory. However, if the operating frequency of the video side and the display frequency of the display are the same, the video information is not stored in the memory and the video information is stored in the video memory. It is also possible to operate the computer side in accordance with the timing of .

Furthermore, in the embodiment, a method has been described in which the palette number is stored in the frame memory and converted into an RGB signal via the palette when displayed, but the color information itself may be stored in the memory.

〔Effect of the invention〕

As described above, according to the present invention, video information is displayed only in the part where a specific pattern is stored on the frame memory, so the display is not limited to a rectangular shape.

Video information can be displayed in an arbitrarily shaped area. Furthermore, if one dot is represented by n bits, the only color that cannot be used freely on the computer side is one of the 2'' colors, and there is very little control over color usage, and the determination of the video display area is
It is extremely stable compared to conventional methods that operate at the analog information level.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, FIGS. 2 and 3 are diagrams showing an example of how multi-windows overlap, and FIG. 4 is a diagram showing a conventional example. 1...Display, 2...Video device, 3...
Calculator, 4.5...D/A converter, 6.7...Switch, 8...Comparator, 9...Inverter, 1
0...Video device, 11...Clock, 12...
Video memory, 13... Frame memory, 14, 15
...CRTC116...Palette, 17...Video color register, 18...Comparator, 19...Analog switch, 20...Delay element, 21, 22.2
3...Window. Cheers / Figure 2. ／ Te body spray

Claims (1)

[Claims] 1. In a device that displays a combination of digital information from a computer and analog information from a video device on a single display, the digital information and analog information can be displayed depending on the content of the digital information corresponding to the display position on the display. A superimposed display method characterized by controlling which one is displayed.