JPH0679206B2 - Video switch device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a video switch device for arbitrarily switching a large number of input video signals in which video signals of different modes are mixed and displaying them on a plurality of CRT displays. It is a thing.

(Prior Art and its Problems) FIG. 3 is a block diagram showing an example of a circuit configuration of a video switch device of a stock price information display system used for trading business. Reference numeral 1 denotes a video switch matrix circuit, which selects arbitrary video signals from video signals S _{1 to} S _n having various information contents sent from a plurality of information sources by a selection signal from a control device 2. Multiple CRT displays on workstations at 3
Is a switching circuit for switching to each of D _{1 to} D _m for transmission.
These video signals S _{1 to} S _n may have different modes such as operating frequency, number of scanning lines, retrace time (blank time), and sync signal, that is, image size depending on the information source.

Reference numeral 2 denotes a control device, which sends a selection signal for selecting a CRT display to be displayed from the control circuit 2a to the video switch matrix circuit 1 in response to an instruction input from the keyboard 4. At the same time, the image size control information corresponding to each of the video signals S _{1 to} S _n previously stored in the storage circuit 2b is selectively read from the storage circuit 20 by the selection circuit 2c, and the image size control signal corresponding to the video signal to be displayed. As each
It is sent to the CRT display 3 through the transmission line 8.

Reference numeral 3 is a CRT display (D _{1 to} D _m ) that can automatically display input image signals of different image sizes (modes) within a predetermined range in an appropriate image size according to the image size control signal that is input at the same time. It is a scan type (automatic scanning line adjustment type) CRT display.

Reference numeral 4 denotes a keyboard, and a key operation for selecting and designating an arbitrary video signal from a plurality of input video signals S _{1 to} S _n is performed for each of D _{1 to} D _m of the CRT display 3. By this key operation, the image size control information corresponding to the input video signal of the specified channel is simultaneously read from the storage circuit 2b and input from the selection circuit 2c to the specified CRT display via the transmission path 8, respectively. It

FIG. 4 is a time chart showing an example of a conventional video signal. S _d is an image signal, H _s is a horizontal synchronizing signal, V _s is a vertical synchronizing signal, and V _b is a vertical back porch period. Input video signal
S _{1 to} S _n may have time charts of different modes (image sizes) depending on the information source.

As described above, in the conventional device, the control device 2 as shown in FIG. 3 to the CRT display 3 requires a transmission path 8 for transmitting the image size control signal, a video signal S ₁ to S _Since it is necessary to store predetermined image size control information for each _n in the storage circuit 2b in advance, when the video signals S _{1 to} S _n are added or changed, the control device 2 is added and changed and transmitted. Economical because it is necessary to add or change the road 8.
There was a problem with the installation space.

(Object of the Invention) The present invention has been made to solve the above problems,
Image of the display screen in a video switch device that arbitrarily switches between multiple input video signals in which image signals with different modes (screen sizes) coexist and selects from multiple CRT displays. An object of the present invention is to provide a video switch device capable of displaying an image of a desired image size on all CRT displays without providing a dedicated transmission path for size control signals.

(Structure and Operation of the Invention) In the video switch device according to the present invention, a first interface circuit is provided at each input portion of a video switch matrix circuit for inputting a plurality of video signals to a plurality of input terminals, and video signals to be respectively input. The image size control signal corresponding to is read out from a storage circuit that is stored in advance and is combined with a video signal, and then input to the video switch matrix circuit as a composite image signal. The composite image signal input to the video switch matrix circuit is switched to the CRT display to be displayed among the plurality of CRT displays according to the selection signal by the keyboard operation, and is sent out.
It is input to the second interface circuit provided on each input side of the display. The composite image signal input to the second interface circuit is separated into a video signal and an image size control signal and simultaneously input to a CRT display to display an image of a desired image size.

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

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

5 is a first interface circuit, 5a is a storage circuit or preliminarily stored the image size control information corresponding to each of the input video signal S ₁ to S _m. Reference numeral 5b is a composite circuit that encodes the output read from the storage circuit 5a and combines it in the back porch period of the video signal. The combined composite image signal is input to the video switch matrix circuit 1 and is switched and output to the second interface 6 provided on the input side of the CRT display 3 designated by the keyboard.

6 is a second interface circuit provided on the input side of each CRT display 3, and 6a is a separation circuit for separating the composite image signal into a video signal and an image size control signal,
Reference numeral 6b is a storage circuit for storing the separated and extracted image size control information.

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

Although the above operation is omitted in the figure, it goes without saying that a control unit controlled by a computer is provided.

FIG. 2 is a time chart showing an example of a composite image signal in which an image size control signal is combined with a video signal according to the present invention. Image signal S _d , horizontal sync signal H _s , vertical sync signal
V _s and the vertical back porch period V _b are the same as the video signal of FIG. D _s is the image size control information inserted by the present invention. A circuit for combining or separating the image size control information with the video signal is a known technique, and thus its detailed description is omitted.

(Effect of the Invention) As described in detail above, according to the present invention, the image size control is performed by combining the image size control information in the back porch portion of the input video signal and separating the composite on the input side of the selected CRT display. There is no need for a dedicated transmission line for signals,
This is particularly effective when the video switch matrix circuit 1 and the CRT display 3 are installed at different locations.

Further, since the control device 7 does not need the conventional storage circuit 2a and control circuit 2b and does not need the image size control signal sending function, there is no influence due to the change or expansion of the video signals S _{1 to} S _n . The effect such as easy system change is remarkable.

[Brief description 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 in which an image size control signal according to the present invention is combined, 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. 1 ... Video switch matrix circuit, 2, 7 ... Control device, 3 ... CRT display, 4 ... Keyboard, 5,6 ... Interface circuit, 8 ... Transmission path, 2a ... Control circuit, 2b, 5a, 6b
... memory circuit, 2c ... selection circuit, 5b ... composite circuit, 6a ... separation circuit.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location H04N 5/268 2109-5C 5/66 D 9068-5C 7/087 6942-5C

Claims (1)

[Claims] 1. A plurality of automatic scanning line adjustments in which a plurality of video signals input to a plurality of input terminals of a video switch matrix circuit are connected to a plurality of output terminals of the video switch matrix circuit by a selection signal from a keyboard. Type CRT displays, each of which is arbitrarily designated and output to be controlled so as to display the video signal on the CRT display in a predetermined image size, in each of the plurality of input terminals of the video switch matrix circuit, A storage circuit that stores in advance image size control information for displaying a predetermined image size on the CRT display corresponding to each of a plurality of video signals,
A first interface circuit including a composite circuit that combines the stored image size control information with the video signal and inputs the composite image signal to the video switch matrix circuit; the video switch matrix circuit; CRT
A second interface circuit which is respectively connected between the respective inputs of the display and which separates the composite image signal from the video switch matrix circuit into a video signal and image size control information and supplies the CRT display with the second interface circuit; And a control device for arbitrarily selecting the plurality of video signals input to the video switch matrix circuit by the selection signal and controlling the screen display on a desired CRT display.