JPS6143090A - Transmitting circuit of video signal - Google Patents

Abstract

PURPOSE:To simplify the circuit constitution, to reduce cost and to miniaturize a circuit by A/D-converting sequentially plural analog signals separated from a video signal in the prescribed order, and transmitting serially the digital output signals to a video bus. CONSTITUTION:A synchronizing signal, clock signal SYNC, color signals R, G and B and a luminance signal Y are separated from a color composite video signal 7 inputted to a synchronization/color separation circuit 1. The synchronizing and clock signals are inputted to a control circuit 5, and used for timing the switching signal of a picture. Besides, they are transmitted to a video bus 6 through a transmitting circuit 3. On the other hand, one of the color and luminance signals is selected in a selecting circuit 4 through the specification from the circuit 5, transmitting to an A/D converter 2, converted into a digital signal and transmitted to the bus 6 through the circuit 3. When the color and luminance signals are digitally converted one by one with use of one converter 2 in such a way, the number of A/D converters and that of video buses can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a video signal transmission circuit that processes and transmits video signals of an image processing device used in a visual system of a robot or the like.

[Prior art]

A conventional device of this type is shown in FIG. 1. In FIG.
/D conversion circuit, 3 is a sending circuit, and 6 is a video bus.

Next, the operation will be explained. The synchronization/color separation circuit l inputs the color composite video signal 7 sent from an external camera, separates the synchronization signal and clock signal 5YNC,
When this is sent to the sending circuit 3, the video signal is converted into a color signal and a luminance signal (R, G).

B, Y) and sent to A/D conversion circuits 21 to 24, respectively.

The A/D conversion circuits 21 to 24 convert analog signals into digital signals, and output the digital signals and A/D* converted clock signals to the sending circuit 3. The sending circuit 3 is composed of a drive IC, and outputs input signals from the A/D conversion circuits 21 to 24 and the synchronization/color separation circuit 1 to the external video bus 6.

Since the conventional video signal transmission circuit was configured as described above, four A/D conversion circuits were required, and the number of signal lines for the external video bus increased, making these six complicated circuits expensive. , there were drawbacks such as complexity.

[Summary of the invention]

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and it sequentially A/D converts a plurality of analog signals separated from a video signal in a desired order, and serially converts the digital output signals. The object of the present invention is to provide a video signal transmission circuit that can be configured at low cost and in a small size by transmitting video signals to a video bus.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows a video signal sending circuit according to an embodiment of the present invention. In the figure, l is a synchronization/color separation circuit, 2 is an A/D conversion circuit, 3 is a sending circuit, and 4 is a color signal (R, G, B) or a luminance signal (Y) according to instructions from a control circuit described later. A selection circuit for switching selection, 5 is the above A/D
This is a control path that outputs a 2-bit selection signal for selecting the color signal and brightness signal input to the conversion circuit 2, and is connected to the host system (host I/F) which is the upper Φ controller that controls this control circuit 5. ) is connected to. Further, this control circuit 5 receives input of a synchronization signal and a clock signal separated from the color signal and luminance signal, and outputs these to the sending circuit 3.

Next, the operation will be explained. The synchronization/color separation circuit 1 and the sending circuit 3 operate in the same manner as conventional ones. and,
In the control circuit 5 connected to the upper host system, the order in which color signals and luminance signals are sent in series is stored in a desired combination procedure according to instructions from the host system, and the switching is performed for each screen. Send the selection signal to the selection circuit 4^. Here, the selection signal only needs to be 2 bits (SQ, 31), and this signal allows RlG,
It is possible to switch between the B and Y signals. Here, it is not necessary to send all four signals R, G, B, and Y, and depending on the case, only the Y signal or Y, R.

Only two types of Hayabusa, Y, R, . . . may be transmitted.

In this embodiment device equipped with such a circuit, synchronization and
Color minute 1 Illia road! The color composite video signal 7 input to the synchronous □ signal and the clock signal 5YNC
, color signals (R, G, B), and luminance signals (Y). The synchronization signal, signal and clock signal are input to the control circuit 5, used for timing the image switching signal, and are also sent to the video bus 6 via the sending circuit 3. On the other hand, the color signal and brightness signal are selected by the control circuit 5 according to the instructions from the control circuit 5! 4, one of them is selected and sent to the A/D conversion circuit 2, where it is converted into a digital signal. is sent to.Furthermore,
A 2-bit selection signal from the control circuit 5 is also sent to the video bus 6 via the sending circuit 3.

As described above, according to the configuration of this embodiment, one A/D converter 2 is used to sequentially convert the color signal and the luminance signal into digital signals, so that the signals of the A/D converter and video bus are The number of wires can be reduced, resulting in an inexpensive and compact device.

Note that in the above embodiment, a synchronization/color separation circuit is provided.
However, if this function is provided on the camera side, the color signal, brightness signal, and synchronization signal may be input directly from the camera. In addition, the switching of the sending signal is -, l1iJI
Although the description has been given of the method performed in units of A, it may also be performed in N4I times of one horizontal scanning time or in units of one image.

Furthermore, in the above embodiment, the video signal of the color composite video signal is separated into R, G, B, and Y signals, but it may be separated into multiple analog signals other than this. , similar effects to those of the above embodiment are achieved. .

〔Effect of the invention〕

As described above, according to the video signal sending circuit according to the present invention, a plurality of analog signals separated from the video signal are A/D converted in a time division manner, and the digital output signals are sent out in series to the video bus. Since the circuit is constructed in such a manner that the circuit can be made at low cost and the wiring of the video bus can be simplified.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional video signal sending circuit, and FIG. 2 is a block diagram showing a video signal sending circuit according to an embodiment of the present invention. 2... A/D conversion circuit, 3... Sending circuit, 4...
Selection circuit, 5...control circuit, 6...video bus. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) A selection circuit that inputs a plurality of analog signals separated from a video signal and selects one of the plurality of analog signals according to a selection signal described later, and an analog output signal from the selection circuit. control for inputting one A/D conversion circuit that performs /D conversion, a synchronization signal and a clock signal separated from the video signal, and outputting a selection signal, a synchronization signal, and a clock signal that determine the selection procedure of the selection circuit; a circuit, and a digital output signal from the A/D conversion circuit,
A video signal sending circuit comprising: a sending circuit that outputs a selection signal from the control circuit, the synchronization signal, and a clock signal to an external video bus.