JPH02164123A - Video switching device - Google Patents

Abstract

PURPOSE:To make the device compact and by adopting a matrix circuit for a video switching device and applying switching control to selector switches of the matrix circuit and to obtain an output picture with the best quality by weighting a termination resistor and connecting only an optimum termination resistor electrically to a selected output. CONSTITUTION:Input devices 1-11 and output devices 12-15 are connected to the matrix circuit 9 having lots of selector switches 18. Each selector switch 18 is subject to switching control by a controller 20. The controller 20 closes a selector switch 18 of a matrix circuit 19 corresponding to an input/output device by a console device 21, the selected input device and output device are connected electrically and a video image of the selected input device is sent to the selected output device. Moreover, the controller 20 weights a termination resistor 17 in response to the selected input and output device and every time the number of the selected input and output devices is changed by the console device 21, an optimum termination resistor 17 is calculated to clock the corresponding switch 16.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a video switching device that transmits video from a number of input devices to one or more arbitrary output devices.

(Prior Art) Conventionally, when transmitting images from a plurality of input devices such as a personal computer or a video device to a plurality of arbitrary output devices such as a television or a large display device, a video switching device, so-called a switcher, is used.

(Comments to be solved by the invention) However, according to the conventional method described above, when the number of input/output devices connected to a switcher increases, the size increases and the switching operation becomes complicated, making it difficult to always switch. There is an inconvenience that the process is not performed smoothly, and furthermore, there is an inconvenience that noise, synchronization disturbance, ringing, etc. are likely to occur on the screen of each output device due to interference between input devices and cables.

(Means for Solving the Problems) The present invention seeks to provide a device that eliminates the above-mentioned disadvantages, and the device of claim 1 has a large number of input/output devices connected to it in order to smoothly perform switching. In addition, it shall consist of a matrix circuit having a large number of selection switches, selection means for selecting the number of input/output devices, and control means for closing the selection switch of the matrix circuit according to the number of the selected input/output device. The apparatus of claim 2 is the apparatus of claim 1, in which each output device is connected to a terminating resistor via a switch in order to eliminate noise, and the control means selects one of the terminating resistors of the output device selected by the selection means. Characterized by closing the switch of the optimal termination resistor.

(Function) According to the device of claim 1 having the above configuration, the input device and the output device selected by the selection means are connected through the matrix circuit by closing the selection switch of the corresponding matrix circuit. The selected input device is electrically connected to the selected output device, and the video is transmitted from the selected input device to the selected output device.

Further, according to the device of claim 2 having the above configuration, in the device of claim 1, the switch of the optimum terminating resistor among the terminating resistors of the selected output device is closed by the control means, and the output device whose switch is closed Only the terminating resistor and the terminating resistor are electrically connected.

(Example) Next, embodiments of the present invention will be described based on the drawings.

In FIG. 1, reference numerals 1 to 10 are personal computers or terminals as input devices equipped with a CRT display device, and signals from these are composed of R-G-B separate signals and H-V synchronizing signals.

Reference numeral 11 denotes a video device as an input device, and the signals from it are composed of NTSC signals from a video camera, television, etc.

12 to 15 are large display devices that are output devices, specifically a 3-inch television equipped with an auto scan function,
This is a video projector with a multi-sync function. Each output device is connected to a termination resistor 17 via a switch 16.

Input devices 1 to 11 and output devices 12 to 15 are connected to a matrix circuit 19 having a large number of selection switches 18.

Each selection switch 18 is connected to a control device 2 serving as a control means.
Opening/closing is controlled by 0.

The control device 20 closes the selection switch 18 of the matrix circuit 19 corresponding to the input/output device selected by the console device 21 serving as the selection means, and electrically connects the selected input device and output device via the matrix circuit 19. and transmit the video of the selected input device to the selected output device. Furthermore, the control device 20 weights the terminating resistor 17 according to the selected input/output device, and calculates the optimal terminating resistor 17 each time the number of the person/output device selected by the console device 21 is changed. , closes the corresponding switch 16.

Here, the functions of the control device 20 will be further explained based on FIG. 2.

Reference numeral 204 denotes an input boat, which is configured by USART, is controlled by a control line 207, receives the number of the input/output device transmitted from the console device 21 in the preceding stage, and transfers it to the CPU 201 in the succeeding stage.

The control device 20 is a well-known microcomputer, and basically includes a CPU 201, a RAM 202, and a ROM 20.
Consists of 3.

A program for controlling the CPO 201 is written in the ROM 203. According to this program, the CPO 201 sorts the data taken in from the input boat 204 into input device numbers and output device numbers, and stores them in the RAM.
The data is stored in the output boat 202, or the data is transferred and processed, and the processed data is sent to the output boat 202.
Output to 05.208.

The output boats 205 and 20B each have a signal line 20.
It consists of several output device ports controlled by g. Each boat except one boat is connected to a matrix circuit 19 to switch input/output devices. The remaining one port is for connecting the terminating resistor 17, and one bit opens and closes the switch 16 of each terminating resistor 17.

Next, the program of the control device 20 will be explained based on FIG.

First, after receiving the input/output device number transmitted from the console device 21, it is checked whether it is an input device number or an output device number (step 1.2). When it is an input device number, I? Write zero in the input number memory of AM202 (step 3), and similarly, when it is the output device number,
After writing zero to the output number memory of the RAM 202 (step 4), write the input device number and output device number to RA.
Write to M202 (step 5.6).

Next, if it is a human-powered device, check the output number memory (step 7.8); if it is an output device, check the input number memory (steps 9-10); if it is zero, write the input device number to the output device boat. is output (step 11).

Next, compare all the input device numbers up to the previous time with the current input device number (step 12), and if there are identical numbers (step 13), set the largest number among the output device numbers. (ffi discovery step 14
) If the same number does not exist, set the current output device number (step 15). Finally, it outputs an open/close signal for the switch 16 of the terminating resistor 17 (step 1B) and waits for reception again.

Next, the specific operation of this embodiment will be explained.

■, For example, input device number 1 is sent to the control device 20 by the console device 21 (consisting of a changeover switch).
and transmits output device number 2.

2. The control device 20 receives these number data (card addresses) and selects the designated selection switch 1B (S
V40) is closed, and the image of the first input device is projected onto the second output device.

3. Next, the control device 2o selects the optimal terminating resistor 1.
7, close switch 1B (ESV2). At this time, since only the second output device is used, there is no need to perform calculations.

4. Control device 2 again by console device 21
0, for example, the input device number 1 and the output device number 4 are transmitted.

5. Upon receiving these number data, the control device 20 closes the designated selection switch 1g (8v14), and
The image of the No. 4 input device is projected onto the No. 4 output device.

6. Next, the control device 20 compares the addresses of the No. 2 output device and the No. 4 output device, which are electrically connected to the No. 1 input device, and of course the address of the No. 4 output device has weight, so , ESν2 is opened and ESI/4 is closed, and the termination resistor 17 is electrically connected to the No. 4 output device. In other words, only one terminal resistor 17 on the same source line with a larger address is electrically connected.

Although the specific operation of this embodiment has been described above, in some combinations of input devices and output devices (for example, a combination of four input devices and two output devices), the selection circuit of the termination resistor 17 can be implemented only by hardware. Although it is possible to configure several dozen combinations (for example, a combination of 16 input devices and 8 output devices)
However, if it were to be constructed only from hardware, it would be enormous and difficult, so a matrix circuit 19 having a selection switch 17 whose opening/closing is controlled by a control means as in the present invention is indispensable.

Note that the source line of the video device serving as the input device is a separate line when only a video signal is received, and may be ignored.

Note that when switching the video signal by opening and closing the selection switch 18, or when opening and closing the switch 16 to electrically connect only the optimum terminating resistor 17, flickering of the image, disturbance of synchronization, etc. may occur. To prevent this, blanking the video signal (reducing the level of the video signal to below Ov)
to prevent the image from being displayed during this time. A series of switching operations are performed during this blanking, and the timing can be easily determined by software.

(Effects of the Invention) As described above, according to the device of claim 1, the video switching device is formed into a matrix, and the selection switches of this matrix circuit are controlled to open and close by the control means, so that a large number of input/output devices are required. However, the video switching device can be made more compact, and the video of a specific input device can be easily transmitted to a target output device.

Furthermore, according to the apparatus of claim 2, the control means weights the terminating resistors, closes the switch of the optimal terminating resistor, and electrically connects only the optimal terminating resistor to the corresponding selected output device. Therefore, there is no noise in the image of the output device, no change in color tone due to a change in phase, no disturbance of synchronization, etc., and it is possible to obtain an output image of high quality.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing one example of implementation of the device of the present invention, and FIG.
The figure is a diagram explaining the function of the control means, and FIG. 3 is a flowchart explaining its operation. 1 to 11... Input device 12 to 15... Output device 1
6...Switch 17...Terminal resistor 18...
Selection, switch 19... Matrix circuit 20...
・Control device (control means) 21...Console device (selection means) patent Applicant Toei Kogyo Co., Ltd. Procedural Amendment 9th February 1999

Claims (1)

[Claims] 1. A matrix circuit to which a large number of input/output devices are connected and has a large number of selection switches, a selection means for selecting the number of the input/output device, and a number of the selected input/output device. and a control means for closing a selection switch of a matrix circuit in accordance with the above. 2. Each output device is connected to a terminating resistor via a switch, and the control means closes the switch of the optimum terminating resistor among the terminating resistors of the output device selected by the selecting means. Video switching device.