JPH01237688A - Interface circuit of personal computer - Google Patents

Abstract

PURPOSE:To enable superimposing with a television receiver by providing an RGB decoder circuit, a selector circuit which selects the horizontal and vertical synchronizing signals of the television receiver and a personal computer and an RGB mixing circuit to the above circuit. CONSTITUTION:The RGB decoder circuit which obtains R, G, B signals from video signals from the television receiver, etc., and obtains the horizontal and vertical synchronizing signals therefrom and the RGB mixing circuit 3 which mixes respectively the R, G, B signals and the R, G, B signals obtd. on the personal computer side and outputs the mixed signals to an analog 15 pin connector of the television receiver are provided to the above circuit. The selector circuit 4 which selects the horizontal and vertical synchronizing signals of the television receiver and the horizontal and vertical synchronizing signals of the personal computer side and outputs the selected signals to the personal computer side is provided thereto. The superposition of the image plane obtd. by the personal computer and the image plane by the video signals and the display of the superposed images on the television receiver are thereby enabled.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides an analog 15-pin connector I built into a television receiver such as an AV (Audio Visual).
/F, it relates to the interface circuit of a personal computer that outputs R, G, B signals, etc., and more specifically, it mixes the video signal etc. from a television receiver and the R, G, B signals obtained by the personal computer. This invention relates to an interface circuit that enables superimposition using the television receiver.

[Conventional example] In recent years, commercially available television receivers such as AV have a built-in analog 15-pin connector I/F. The analog 15-pin connector provided on this television receiver is
Although no official standard has been determined, the terminal arrangements for analog R, G, B signals (video signals), horizontal synchronization signals, and vertical synchronization signals are the same for each manufacturer. Therefore, personal computers can be connected to television receivers from various manufacturers, and personal computer screens can be displayed on these television receivers.

[Problem to be solved by the invention] By the way, through the analog 15 pin connector mentioned above.

When a personal computer and a television receiver are connected, the screen obtained by the personal computer can be displayed, but the screen by the television receiver, for example, the screen by VTR or television broadcast, and the screen by the personal computer. In other words, when trying to perform superimposition, a complicated and large-scale circuit was required.

This invention was made in view of the above problems, and its purpose is to provide an AV device with a built-in analog 15-pin connector I/F.
An object of the present invention is to provide a low-cost interface circuit that can be superimposed on television receivers such as the above.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides R, G
, B signals, etc. to the television receiver, which obtains R, G, and B signals from the video signal from the television receiver, and also performs horizontal and vertical synchronization of the television receiver. a KGB decoder circuit for obtaining a signal; a selector circuit for switching between the horizontal and vertical synchronizing signals of the television receiver and the horizontal and vertical synchronizing signals of the personal computer;
R, G, B signals obtained by the RGB decoder circuit and R, G, B signals obtained by the personal computer side.
The mixed R, G, and B signals are respectively connected to the analog R of the analog 15-pin connector.
It includes a signal terminal, an RGB mixing circuit that outputs to an analog G signal terminal and an analog B signal terminal.

[Function] In the above configuration, a video signal from the television receiver, etc. is input, and the RGB decoder circuit obtains R, G, B signals and vertical and horizontal synchronization signals from the video signal, and the personal computer In accordance with the instruction, the R, G, B signals of the personal computer screen and the R, G, B signals of the input video signal are mixed in the RGB mixing circuit. Analog 1 above
Mixed R and G to the specified terminals of the 5-pin connector, respectively.
, B signals, and horizontal and vertical synchronization signals for synchronizing with the television receiver.

As a result, the screen based on the video signal and the computer screen are displayed in a superimposed manner on the television receiver equipped with the analog 15-pin connector.

[Example] Embodiments of the present invention will be described below based on the drawings.

In the figure, 1 is a connector that is connected to an analog 15-pin connector I/F built in a television receiver such as an AV as in the past, and this connector has a vertical synchronization signal terminal 1a, a horizontal synchronization signal terminal 1b, and an analog R ,G,B
(The R signal terminal 1c, G signal terminal Ld, and B signal terminal 1e from which the i (video signal) is output have the same pin arrangement as the analog 15-pin connector.

A video signal obtained from the above-mentioned television receiver or the like is inputted to the RGB decoder circuit 2 via the video signal output terminal of the above-mentioned analog 15-pin connector, and is decoded by the RGB decoder circuit 2. B signal is RG
Input to B mixing circuit 3, vertical (Vo)/horizontal (H,)
A synchronizing signal is input to the selector circuit 4. In addition to the vertical (VO) and horizontal (HO) synchronization signals, horizontal and vertical synchronization signals from the personal computer are input to the selector circuit 4, and these signals are selected and used as synchronization signals for the personal computer. In addition to the R, G, and B signals obtained from the RGB decoder circuit 2, the RGB mixing circuit 3 also receives R, G, and B signals obtained from the personal computer (signals from the screen of the personal computer).
At the same time, a horizontal (H) synchronization signal based on the synchronization signal obtained by the selector circuit 4 is input.

That is, the vertical (V) synchronization signal for synchronizing with the television receiver is a signal output from the personal computer side and is sent to the vertical (H) synchronization signal terminal 1a of the connector 1.
The synchronization signal is sent to the horizontal synchronization signal terminal 1b, the R signal mixed in the RGB mixing circuit 3 is sent to the R signal terminal 1c, the mixed G signal is sent to the G signal terminal 1d, and the mixed B signal is sent to the B signal terminal 1.
e is input from an analog 15-bin connector built into a television receiver such as an AV receiver. In addition, vertical (V)
The horizontal (H) synchronization signal is based on the synchronization signal when a video signal is input, and when the video signal is not input, it is based on the synchronization signal of the personal computer.

Next, the operation of the interface circuit having the above configuration will be explained.

First, a television receiver such as an AV and a personal computer are connected through an analog 15-bin connector and connector 1, and the R, G, and
A personal computer screen based on the B signal and a screen based on a video signal obtained by a television receiver or the like are superimposed and displayed on the television receiver, that is, superimposed. Note that the timing at which the video signal screen and the personal computer screen are overlapped is determined by instructions from the personal computer.

At this time, on the personal computer side, R, G, and B signals of that screen are obtained, and a video signal of a screen that overlaps that screen is also input. The RGB decoder circuit 2 decodes the video signal, iJR, G, B signals, and vertical (V, )-horizontal (Ho) synchronization signals. A selector circuit 4 obtains a synchronizing signal for obtaining R, G, and B signals of a screen to be displayed in synchronization with the television receiver. That is, from the personal computer side to the television receiver, the R, G, and B signals of the screen obtained by the personal computer and the R, G, and B signals of the screen obtained by the video signal are transmitted from the personal computer side to the television receiver.
A synchronization signal for outputting the B signal in synchronization with the B signal is obtained. Then, on the personal computer side, the R, G, and B signals on the computer screen are converted to R at the timing of the synchronization signal.
Vertical (V) and horizontal (H) synchronization signals are obtained which are output to the GB mixing circuit 3 and also to the television receiver. At the timing of the horizontal (H) synchronization signal, the R, G, and B signals from the ROB decoder circuit 2 and the R, G, and B signals from the personal computer are mixed and output from the RGB mixing circuit 3. . That is, its horizontal (
H) The R, G, B signals of the screen obtained by the personal computer and the R, G, B signals of the screen obtained by the video signal are respectively switched based on the synchronization signal, and the connector 1
The signal is output from the R signal terminal 1c, the G signal terminal 1d, and the B signal terminal 1e.

The R, G, B signals obtained in this way and the vertical (V
)・Horizontal (H) synchronization signals are input to the television receiver via an analog 15-bin connector, so the television receiver has a superimposed screen on which the personal computer screen and the video signal screen are superimposed. The pause screen will be displayed.

[Effects of the Invention] As explained above, according to the interface circuit of the present invention, R, G
, B signal, and an RGB decoder circuit that obtains the horizontal and vertical synchronization signals of the television receiver;
, B signal and R obtained on the personal computer side,
G and B signals are mixed respectively, and the mixed R, G,
An RGB mixing circuit that outputs the B signal to the analog R signal terminal, analog G signal terminal, and analog B signal terminal of the analog 15-bin connector of the television receiver, and the horizontal and vertical synchronization signals of the television receiver and the personal computer side. A selector circuit is provided which selects the horizontal and vertical synchronizing signals and outputs them to the personal computer side.

A screen obtained by a personal computer and a screen obtained by a video signal can be superimposed and displayed on a television receiver, so-called superimposition. Moreover, analog 1
Any type of television receiver, such as an A/V receiver, that has a built-in 5-pin connector I/F can be used, has versatility, and has the advantage of being able to be provided at a low cost.

[Brief explanation of the drawing]

The figure shows an interface circuit for a personal computer showing an embodiment of the present invention. In the figure, 1 is a connector (corresponding to an analog 15-pin connector), 1a is a vertical (V) synchronization signal terminal, and 1b is a horizontal (
H) Synchronous signal terminals, 1c is an R signal terminal, 1d is a G signal terminal, 1e is a B signal terminal, 2 is an RGB decoder circuit, 3 is an RGB mixing circuit, and 4 is a selector circuit.

Claims (1)

[Claims] (1) A personal computer interface circuit that outputs R, G, B signals, etc. to a television receiver through an analog 15-pin connector provided in the television receiver, which outputs video signals from the television receiver, etc. More R
, G, and B signals, and an RGB decoder circuit that obtains horizontal and vertical synchronization signals of the television receiver, and switches between the horizontal and vertical synchronization signals of the television receiver and the horizontal and vertical synchronization signals of the personal computer. R, G, B signals obtained by the selector circuit, the RGB decoder circuit, and the R, G, B signals obtained by the personal computer side.
The mixed R, G, and B signals are respectively mixed with the analog R signal of the analog 15-pin connector.
It is equipped with an RGB mixing circuit that outputs to a signal terminal, an analog G signal terminal, and an analog B signal terminal, into which the video signal, etc. is input, and the R, G, B signals obtained by the personal computer and the input video signal. are mixed, and the mixed R, G, B signals and horizontal and vertical synchronization signals for synchronizing with the television receiver are output to predetermined terminals of the analog 15-pin connector. An interface circuit for a personal computer.