JPH03116091A - Video switch device - Google Patents

Abstract

PURPOSE:To display an image of a desired image size on all CRT displays by compounding image size control information to a back porch part of an input video signal and separating it on an input side of a selected CRT display. CONSTITUTION:A first interface circuit 5 is provided on each input part of a video switch matrix circuit 1, and image size control signals corresponding to inputted video signals S1 - Sn are readout of a storage circuit 5a in which they are stored in advance and compounded to the video signals S1 - Sn, and thereafter, inputted as a composite image signal to the circuit 1. Subsequently, the composite image signal is switched and sent out to CRT displays 3 to be displayed, respectively in plural CRT displays 3D1 - Dm by a selecting signal by operating a keyboard 4, and inputted to a second interface circuit 6 provided on the respective input sides of the CRT displays. The composite image signal inputted to a second interface circuit is separated into the video signals S1 - Sn and the image size control signal, and simultaneously, inputted to the CRT display 3. In such a way, an image of a desired image size can be displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical field to which the invention pertains) The present invention relates to a video switch device that arbitrarily switches a large number of input video signals in which video signals of different modes are mixed and displays each on a plurality of CRT displays. It is.

(Prior art and its problems) FIG. 3 is a schematic diagram showing an example of the circuit configuration of a video switch device of a stock price information display system used in trading operations and the like. Reference numeral 1 denotes a video switch matrix circuit, which selects an arbitrary video signal from video signals S, to S7 having various information contents sent from a plurality of information sources by a selection signal from a control device 2. This is a switching circuit that respectively switches and sends signals to D1 to D1 of a plurality of CRT displays 3 provided in a workstation or the like. These video signals S, -S1 may differ in operating frequency, number of scanning lines, retrace time (blank time), mode of synchronization signal, etc., or image size, depending on the information source.

Reference numeral 2 denotes a control device, which controls the video switch matrix circuit 1 from the control circuit 2a by inputting instructions from the keyboard 4.
A selection signal is sent to select the CRT display to be displayed. At the same time, the video signal S1. which is stored in advance in the storage circuit 2b. The selection circuit 2c selectively reads out the image size control information corresponding to steps S7 to S7 from the storage circuit 20, and sends them to the CRT display 3 through the transmission path 8 as image size control signals corresponding to the video signals to be displayed.

3 is a CRT display (D, ~D,), which is an automatic display that can display input video signals of different image sizes (modes) in a predetermined range at the appropriate image size according to the image size control signal input simultaneously. It is a scan quib (automatic scanning line adjustment type) CRT display.

4 is a keyboard, CRT display 3 glue, ~
A key operation is performed to select and designate an arbitrary video signal from among the plurality of input video signals 51 to S7 for each of the input video signals 51 to S7. By this key operation, the image size control information corresponding to the input video signal of the designated channel is simultaneously read out from the storage circuit 2b and input to the designated CRT display via the transmission line 8 from the selection circuit 2c. Ru.

FIG. 4 is a time chart showing an example of a conventional video signal. S4 is an image signal, H is a horizontal synchronizing signal, vl is a vertical synchronizing signal, and ■ is a vertical back porch period. The input video signals S, ~S may have time charts with different modes (image sizes) depending on their information sources.

As mentioned above, the conventional device requires a transmission path 8 to transmit the image size control signal from the control device 2 to the CRT display 3 as shown in FIG. Since it is necessary to previously store predetermined image size control information for each image size in the storage circuit 2b, the video signals S and -S are added.

When a change or the like occurs, it becomes necessary to add or change the control device 2 and also add or change the transmission line 8, which poses economical and installation space problems.

(Object of the invention) The present invention was made to solve the above-mentioned problems.
Multiple CRTs can be created by arbitrarily switching multiple input video signals containing a mixture of image signals with different modes (screen sizes).
To display an image of a desired image size on all CRT displays without providing a dedicated transmission path for an image size control signal of a display screen in a video switch device that displays images on each CRT display selected and designated from among the displays. Our objective is to provide a video switch device that can

(Structure and operation of the invention) A video switch device according to the present invention includes a first interface circuit provided in each input section of a video switch matrix circuit that inputs a plurality of video signals to a plurality of input terminals, and a first interface circuit that inputs a plurality of video signals to a plurality of input terminals. An image size control signal corresponding to the image size control signal is read out from a storage circuit in which it is stored in advance, composited into a video signal, and then inputted to a video switch matrix circuit as a composite image signal. The composite image signal input to the video switch matrix circuit is switched and sent to the CRT display to be displayed among the plurality of CRT displays according to a selection signal from a keyboard operation, and then sent to a second interface provided on the input side of each CRT display. input to the circuit. The composite image signal input to the second interface circuit is separated into a video signal and an image size control signal, and are simultaneously input to a CRT display to display an image of a desired image size.

The present invention will be explained in detail below with reference to the drawings.

FIG. 1 is a block diagram showing the circuit configuration of a video switch device showing an embodiment of the present invention. In the figure, video switch matrix circuit 1. CRT display 3. The keyboard 4 performs the same function as the conventional device shown in FIG.

5 is a first interface circuit, and 5a is a storage circuit that stores in advance image size control information corresponding to each of the input video signals S, -S. 5b is a composite circuit that encodes the output read from the storage circuit 5a and combines it during the back porch period of the video signal. This composite image signal is input to the video switch matrix circuit 1, and is switched and outputted to the second interface 6 provided on the input side of the CRT display 3 specified by the keyboard.

6 is a second one provided on the input side of each CRT display 3.
6a is a separation circuit that separates the composite image signal into a video signal and an image size control signal, and 6b is a storage circuit that stores the separated and extracted image size control information.

Reference numeral 7 denotes a control device which sends a CRT display selection signal to the video switch matrix circuit 1 in response to instructions from the keyboard 4. When the composite image signal input to the video switch matrix circuit 1 is switched according to this selection signal and input to the second interface circuit 6 of the respectively designated CRT display 3, the video signal and the image corresponding to the video signal are switched. The size control information is separated, and the timing of the image size control information and video signal temporarily stored in the storage circuit 6b is adjusted, and the CRT
The image is input to the display and an image of the desired image size is displayed.

Although the above operations are not shown in the drawings, it goes without saying that a control section controlled by a computer is provided.

FIG. 2 is a time chart showing an example of a composite image signal obtained by combining a video signal with an image size control signal according to the present invention. The image signal Sd+horizontal synchronization signal H1+vertical synchronization signal Vll vertical back porch period (2) is the same as the video signal in FIG. Dl is image size control information inserted by the present invention. Since the circuit for combining and separating the image size control information into the video signal is a well-known technique, a detailed explanation will be omitted.

(Effects of the Invention) As described above in detail, according to the present invention, image size control information is combined with the back porch portion of an input video signal and separated on the input side of a selected CRT display. This eliminates the need for a dedicated signal transmission path, and is particularly effective when the video switch matrix circuit 1 and the CRT display 3 are installed far apart.

In addition, the control device 7 includes a conventional memory circuit 2a+control circuit 2.
b is unnecessary, and the image size control signal sending function is no longer necessary, so the video signals S1 to S7 are changed.

There is no impact from expansion, etc., and the effect of making system changes easier is remarkable.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a time chart showing an example of a composite image signal obtained by combining the image size control signal according to the present invention, and FIG. 3 is a configuration example of a conventional device. The block diagram and FIG. 4 are time charts showing an example of the video signal. l...Video switch matrix circuit, 2.7...
・Control device, 3... CRT display, 4...
Keyboard, 5, 6...interface circuit,
8...Transmission path, 2a...Control circuit, 2b+5
a. 6b... Memory circuit, 2c... Selection circuit, 5b.
...Composite circuit, 6a...Separate circuit.

Claims (1)

[Scope of Claims] A plurality of automatic scanning lines are connected to a plurality of video signals input to a plurality of input terminals of a video switch matrix circuit according to a selection signal from a keyboard and connected to a plurality of output terminals of the video switch matrix circuit. Specify each adjustable CRT display arbitrarily and switch output.
In order to control the RT display to display the video signal at a predetermined image size, each of the plurality of input terminals of the video switch matrix circuit is provided with a signal corresponding to each of the plurality of video signals and a predetermined image size on the CRT display. a storage circuit that stores in advance image size control information for displaying at an image size of a first interface circuit comprising: the video switch matrix circuit and the plurality of CRs;
The composite image signal from the video switch matrix circuit is separated into a video signal and image size control information, and is connected to each input of the T display.
a second interface circuit for providing a T-display; and controlling the plurality of video signals inputted to the video switch matrix circuit to be arbitrarily selected and displayed on a desired CRT display according to a selection signal from the keyboard. A video switch device equipped with a control device.