JPS61161885A - Video signal sending circuit - Google Patents

Abstract

PURPOSE:To use commonly an A/D converting circuit and to make the whole of the device low-priced and small by selecting plural analog video signals inputted from plural cameras and connecting the selected signal to one unit of video signal sending circuit. CONSTITUTION:A synchronizing signal of a compound video signal is separated from plural cameras 1 by a synchronizing separating circuit which is not shown in the figure, and plural analog video signals are supplied to a selecting circuit 6. By the indication from a control circuit 8, one of the above-mentioned plural analog video signals is selected, sent to an A/D converter 3 and converted to a digital signal. The selected digital signal is sent through a sending circuit 4 to a video bus 5. The selecting signal from the control circuit 8 is also sent through the sending circuit 4 to the video bus 5. Thus, plural cameras can be used by one video signal sending circuit, and the low-priced and small device can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a video signal transmission circuit for processing and transmitting video signals of an image processing device used in a visual system of a robot or the like.

[Conventional technology]

Conventionally, there was a device of this type as shown in Figure 2.
In the figure, 1 is a camera that inputs black and white video, 2 is a synchronization separation circuit, 3 is an A/D conversion circuit, 4 is a sending circuit, and 5 is a video bus.

Next, the operation will be explained. The synchronization separation circuit 2 receives the black and white composite video signal sent from the camera 1, separates the synchronization signal and clock signal 5YNC, sends it to the output circuit 4, and sends the analog video signal after the synchronization separation to the A/D. It is sent to the conversion circuit 3. The A/D conversion circuit 3 digitally converts the analog video signal into a digital video signal.

A clock signal for A/D conversion is sent to the sending circuit 4. The sending circuit 4 is constituted by a drive IC, and outputs input signals from the A/D conversion circuit 3 and the synchronization separation circuit 2 to the external video bus 5.

[Problem that the invention seeks to solve]

Since the conventional video signal sending circuit is configured as described above, only one camera, which is an input section, can be used, and if a plurality of cameras are to be used, the above-mentioned conventional device is required for each camera. For this reason, there were problems such as the equipment being large (and expensive).

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a video signal sending circuit that can be constructed inexpensively and compactly so that a plurality of cameras can be used in one device.

[Means for solving problems]

A video signal transmission circuit according to the present invention includes a selection circuit that selects a plurality of analog video signals input from a plurality of cameras, and a control circuit that outputs a selection signal that determines the selection procedure of the selection circuit. be.

[Operation] In the present invention, the selection circuit selects one of the analog video signals of the plurality of cameras according to the control signal from the control circuit.
Since two analog video signals are selected, A/D conversion circuits and the like can be used in common.

〔Example〕

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

FIG. 1 shows a video signal sending circuit according to an embodiment of the present invention. In the figure, reference numeral 1 indicates a plurality of cameras as input units, reference numeral 6 indicates selection signals 30. Sl, 32.
..., a selection circuit that switches and selects analog video signals from a plurality of cameras 1; 3, an A/D conversion circuit that A/D converts the analog video signal output from the selection circuit 6; 4;
7 is a sending circuit that serially sends the digital video signal from the A/D conversion circuit 3 to the video bus 5, and 7 is a sending circuit that sends a synchronization signal and a clock signal 5Y to the plurality of cameras 1 and a control circuit 8 to be described later.
A synchronization generating circuit 8 provides selection signals SO, Sl, S2 . ... and sends out the synchronization signal from the synchronization generating circuit 7 and the clock signal 5YNC to the sending circuit 4, and this control circuit 8 is a host system that is a higher-level controller that controls it. (Host I/F).

Next, the operation will be explained. The A/D conversion circuit 3 and the sending circuit 4 operate in the same way as conventional circuits. The synchronization generating circuit 7 provides a synchronization signal and a clock signal 5YNC to the plurality of cameras 1, which are input units, for synchronously operating the plurality of cameras 1, and also sends the synchronization signal and the clock signal 5YNC to the control circuit 8. The control circuit 8 connected to the upper host system stores the order in which the plurality of video signals are sent in series in a desired combination procedure according to instructions from the host system, and the switching selection signal is stored for each screen. So, 31. S2. ... is sent to the selection circuit 6.

Here, as the selection signal, jog2 (N) bits are required, assuming that the number of cameras is N. Here, it is not necessary to output the video signals of all the connected cameras; for example, it is possible to output the video signals of two of them alternately, one screen at a time, or to always select one camera. good.

In the circuit of this embodiment including such a circuit, the camera 1 receives the synchronization signal and clock signal 5 from the synchronization generation circuit 7.
Black and white composite video signals are synchronously output from all cameras by YNC.

The synchronization signal and clock signal 5YNC are also input to the control circuit 8, used for timing the image switching signal, and are also sent to the video bus 5 via the sending circuit 4. On the other hand, the composite video signals from the plurality of cameras 1 are each separated into a synchronization signal and a clock signal by a synchronization separation circuit (not shown), and one of the plurality of separated analog video signals is sent to a selection circuit according to an instruction from the control circuit 8. 6 is selected and sent to the A/D conversion circuit 3, where the A/D
The conversion circuit 3 converts the signal into a digital signal, and the signal is sent to the video bus 5 via the sending circuit 4.

Furthermore, selection signals SO, S1 . S2,・
... are also sent to the video bus 5 via the sending circuit 4.

As described above, according to the configuration of this embodiment, multiple analog video signals are switched and sequentially converted into digital signals, so multiple cameras can be used with one video signal transmission circuit, which is inexpensive and compact. It can be a device.

In the above embodiment, the transmission signal is switched in units of one screen.
Alternatively, it may be performed N times in units of one screen.

Furthermore, although the above embodiment describes the case of a monochrome video signal transmission circuit, by providing a color separation circuit and a selection circuit between the selection circuit and the A/D conversion circuit, it is possible to create a color video signal transmission circuit. can.

〔Effect of the invention〕

As described above, the video signal transmission circuit according to the present invention is configured so that a plurality of cameras can be connected to one video signal transmission circuit by selecting analog video signals from a plurality of cameras. This has the advantage that the device can be made inexpensive and compact.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a video signal sending circuit according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional video signal sending circuit. In the figure, 1 is the camera of the input section, 2 is the synchronous separation circuit,
3 is an A/D conversion circuit, 4 is a sending circuit, 5 is a video bus,
6 is a selection circuit, 7 is a synchronization generation circuit, and 8 is a control circuit. In the drawings, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] (1) A selection circuit that receives analog video signals from a plurality of cameras and selects one of the plurality of analog video signals according to a selection signal described later, and a synchronization signal and clock for the plurality of cameras. The analog video output signal from the synchronization generation circuit that provides the signal and the selection circuit described above is
The A/D conversion circuit includes an A/D conversion circuit that performs D conversion, and a control circuit that receives the synchronization signal and the clock signal as input and outputs the selection signal that determines the selection procedure of the selection circuit and the synchronization signal and the clock signal. A video signal sending circuit characterized in that it outputs a digital video output signal from the circuit, a selection signal, a synchronization signal, and a clock signal from the control circuit to an external video bus.