JPH05260399A - Selector externally mount expansion device - Google Patents

Abstract

PURPOSE:To simplify a changeover circuit by providing a selector expansion device including an external multi-input circuit and the changeover circuit. CONSTITUTION:A module circuit 1 acts like a selector externally mount expansion device 5. Video terminals and an S terminal input are provided to both video and audio systems and number of input terminals are increased/decreased as required. The signals inputted from each system enter an audio switching ICE, a luminance/video signal changeover IC3, and a color signal changeover IC4, and they are switched by an input changeover command send from a microcomputer. The signal is selected by a control signal sent through the connector from the set side and a power supply. The audio signal (R, L), the video signal and the color signal are given to a photo pin input terminal and the S terminal on a rear side terminal board of a television receiver of the C module circuit 6 ad an internal signal and an external signal are switched in the inside of the television receiver. The changeover circuit inputs the signals selected in advance by the selector externally mounted expansion device to the photo pin terminal of the set, then the changeover circuit is simplified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a selector external expansion device which simplifies a switching circuit of AV equipment used in electronic equipment circuits such as television receivers.

[0002]

2. Description of the Related Art FIG. 3 shows the configuration of an AV switching circuit used in a television receiver and an electronic device circuit. With the recent diversification of AV equipment, even in the case of television receivers, equipment having a plurality of input / output circuits on its rear surface terminal portion has become mainstream, and the circuits have become complicated. The structure is shown in Figure 3.
There are video 1, video 2, BS / expansion input, monitor output, and S terminal input circuit for both the video and audio systems of the J module circuit, and this printed circuit board is screwed together with the back cover at the rear of the set. As the number of additional functions increases, so does the number of access lines. Furthermore, the front terminal of the G module circuit also has video and audio video 3, and an S terminal input. These signals are connected to the H module circuit for audio switching, luminance / video signal switching, and color signal switching circuits, and the input / output signals are switched by an input switching command voltage sent from the microcomputer and further sent to a predetermined circuit. As described above, since there are many input / output systems to the J module board, the circuit becomes complicated and the board area becomes large.

[0003]

When the above-mentioned conventional television receiver and switching circuit for electronic equipment are used,
There are the following problems. (1) Since there are many video 1, video 2, video 3, and S terminals and input circuits, the printed circuit board area of the rear terminals is large and the circuits are complicated. (2) The structure is complicated because there are many HONO pin input / output terminals.

It is an object of the present invention to provide a selector external expansion device for simplifying a switching circuit.

[0005]

In order to achieve the above object, the present invention is to connect a multi-input expansion circuit and a switching circuit to the outside of a HONO pin input terminal of a rear terminal plate of a television receiver to provide a control signal and a control signal. The power supply is connected by a connector and supplied from the set side.

[0006]

According to the present invention, since the plurality of input systems of the television receiver are switched by the selector external expansion device in advance and the signals are supplied to the set side, the switching circuit is simplified by the above-mentioned structure. .

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIGS.

The A module circuit 1 shown in FIG. 1 is an external selector expansion device 5 according to an embodiment of the present invention. Video system,
For audio systems, video 1, video 2, video 3, and S
There is a terminal input, and the number of inputs can be increased or decreased as necessary. The signal input from each system is voice switching 2, brightness /
It is switched by an input switching command sent from a microcomputer (not shown) into the IC of the video signal switching 3 and the color signal switching 4. This signal is selected by the control signal sent from the set side through the connector and the power supply. The switched signals, that is, the audio signals (R, L), the video signals and the color signals are connected to the HONO pin input terminal and the S terminal of the rear terminal plate of the television receiver of the C module circuit 6, and the television receiver. Internal signals and external signals are switched inside. The feature of this switching circuit is that the switching circuit on the set side can be simplified compared to the current one because the signal preselected by the expansion device external to the selector can be input to the HONO pin input terminal of the set, and the circuit board can be simplified. It is possible to reduce the area. FIG. 2 is an exploded perspective view showing a configuration in which the selector external expansion device is attached to the rear terminal portion of the set.

As described above, according to this embodiment, since the external expansion unit is provided and various external signals are switched there, the portion required for switching in the rear portion of the receiver main body is simplified. And, it can be miniaturized.

[0010]

As is apparent from the above embodiments, by providing the selector external expansion device, it is possible to input a pre-switched signal to the HONO pin terminal of the rear terminal board, so that the switching circuit on the set side can be simplified. It is possible to provide a selector external expansion device capable of performing the above.

[Brief description of drawings]

FIG. 1 is a block diagram of an external circuit of a selector according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing attachment of a selector external expansion device.

FIG. 3 is a block diagram of a conventional AV switching circuit.

[Explanation of symbols]

 1 A module circuit 5 selector expansion device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takuo Otsuki 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Yoichi Ishibashi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] 1. An AV switching circuit used in an electronic device circuit including a television receiver, the unit including an external multi-input expansion circuit for connecting to an input terminal of a rear terminal plate of the device and a switching circuit. External expansion device with selector.