JPS61290890A - Character signal multiple adaptor - Google Patents

Abstract

PURPOSE:To color a superposed character signal by an optional color by providing a character generator adaptor with a subcarrier frequency oscillator which has locked in phase to a color burst signal of a composite video signal supplied from a video signal source, and a phase shifting circuit. CONSTITUTION:A continuous color subcarrier signal is shifted in phase by a control signal from a character color selecting circuit 16 in a phase shifting circuit 15, and the character color selecting circuit 16 designates a color of a character signal. The continuous color subcarrier which is shifted in a phase is gated by a character signal 130 from a character signal generating circuit 18, in a gate circuit 17. Accordingly, as for the output of the gate circuit 17, a character signal part goes to a color character signal 140 which is formed by the color subcarrier signal. This color character signal 140 is inputted to a replacing circuit 19, and replaced with a character superposed part of the original composite video signal 110 from a buffer amplifier 12. The output 150 of the replacing circuit 19 goes to a video signal superposed with a terminal 20, and the picture is recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a character signal multiplexing adapter for superimposing a color character signal onto a video signal.

[Background of the invention]

When recording with a video camera or recording video signals from a television receiver, etc., if information such as the date, title, or channel number can be recorded simultaneously on a recording device such as a VTR (hereinafter simply referred to as "VTR"), It becomes very easy to save recordings (hereinafter referred to as programs) and understand the contents of the programs.

In particular, when recording with a video camera, in order to insert characters such as the date and title into the program when producing the program, a board with these characters written on it must be photographed at the beginning of the recording, or a special device called a video captioner is used. Equipment was available or had to be.

In addition, recently, multi-functional video cameras with text/display recording functions have been developed, but incorporating these functions makes the video cameras larger and less mobile as a video camera for general users. There is a problem of loss.

In order to deal with these problems, for example,
As described in Publication No. 7503, a character signal multiplexing adapter (Character, Generator, Adapter 20GA) is inserted between the video signal source and the VTR, and the necessary character signals are added to the video signal of the program. Overlapping has been proposed.

When applying this to a video camera, the video camera 1 is coupled to a VTR 3 via a CGA 2, as shown in FIG.

The use of CGA in this way allows the necessary text signals to be superimposed on the video signal regardless of the functionality of the video camera, and the video insert function can be used to insert text signals into the program after filming. Although this type of CGA has advantages, it has the disadvantage that the video signal is replaced with a white signal in the superimposed character signal portion, and the superimposed characters cannot be colored.

[Object of the Invention] The object of the present invention is to eliminate the drawbacks of the above-mentioned prior art and to improve the CGA
To provide a character signal multiplexing adapter capable of superimposing a colored character signal (color character signal) on a video signal using the above.

[Summary of the invention]

In order to achieve this object, the present invention provides a CGA with a subcarrier frequency oscillator and a phase shift circuit that are phase-locked to the color burst signal of the composite video signal from the video signal source. [Embodiments of the Invention] Hereinafter, embodiments of the present invention will be explained with reference to the drawings.0 Figure 1 shows an embodiment of the character signal multiplexing adapter according to the present invention. It is a block diagram showing an example, and 11 is a composite video signal input terminal from a video signal source such as a video camera, 12 is a buffer amplifier, 13 is a color burst signal extraction corridor, and 14 is a block diagram showing an example.
15 is a phase lock oscillator, 15 is a phase shift circuit, 16 is a character color selection circuit, 17 is a gate circuit, 18 is a character signal generation circuit 119 is a replacement circuit.

Further, FIG. 2 is a signal waveform diagram of each part of FIG. 1, and 11
0 to 150 are shown in FIG. 1, respectively [this is the signal waveform of the corresponding number part].

In FIGS. 1 and 2, a composite video signal (120) from an input terminal 11 passes through a buffer amplifier 12 and is supported by a color burst signal extraction circuit 13, from which a color burst signal f0 is extracted. The extracted color burst signal fa (120) is applied to the phase lock oscillator 14.

The phase-locked oscillator 14 generates a color burst signal (120)
oscillates a continuous color subcarrier signal locked to the phase of In addition, this part includes 7A's, Locked, /
Preferably, a PLL is used. The continuous color subcarrier signal is phase-shifted in a phase shift circuit 15 by a control signal from a character color selection circuit 16. A character color selection circuit 16 specifies the color of the character signal. The phase-shifted continuous color subcarriers are gated in a gate circuit 17 by a character signal (1sO) from a character signal generating circuit 18.

Therefore, the output of the gate circuit 17 is a color character signal (1
40). This color character signal (140) is input to a replacement circuit 190 and is replaced with the character superimposed portion of the original composite video signal (110) from the buffer amplifier 12. The output (150) of the replacement circuit 19 is a video signal with colored characters superimposed on it, and is supplied to the VTR from the output terminal 20 and recorded.

〔Effect of the invention〕

As explained above, according to the present invention, a color character signal can be superimposed on a video signal with a simple circuit configuration, and a character signal multiplexing adapter with excellent functions can be provided without the drawbacks of the above-mentioned conventional technology. can.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the character signal multiplexing adapter according to the present invention, FIG. 2 is a signal waveform diagram of each part of FIG. 1,
FIG. 3 is a conceptual diagram for explaining the combination of character signal multiplex adapters. 12... Buffer amplifier 13... Color burst signal extraction circuit 14... Phase lock oscillator 15... Phase shift circuit 16... Character color selection circuit 176. , gate circuit 18...Character signal generation circuit 19...Replacement circuit

Claims (1)

[Claims] A character signal multiplexing adapter that superimposes a color character signal on a composite video signal from a video signal source includes a color burst signal extraction circuit that extracts a color burst signal from the composite video signal, and a color burst signal extraction circuit that is phase-locked to the extracted color burst signal. A phase lock oscillator that oscillates a color subcarrier signal, a phase shift circuit that shifts the phase of the color subcarrier signal, and a character signal generation circuit. A character signal multiplexing adapter characterized in that a color subcarrier signal is gated and the gated color subcarrier signal is superimposed on the composite video signal.