JPH01274591A - S-vhs video input changeover circuit - Google Patents

Abstract

PURPOSE:To eliminate need for a changeover switch operation when a video input terminal only is in use by providing an interlocking switch to an S-VHS video input terminal and applying circuit constitution where a video changeover switch is operated only with the connection of device. CONSTITUTION:When no S-VHS color signal input terminal 1 and no luminance signal terminal 2 are connected to a device, an interlocking switch 10 is closed and a changeover switch control terminal 6 is connected to ground. In this case, a color signal changeover switch 4 and a luminance signal changeover switch 5 are fixed to the position B and an input is given to a composite video input terminal 3 only. Even with the video changeover switch 7 turned to the position A or B, the terminal 6 is connected to ground and the input is available for the terminal 3 only. With a device connected to the terminals 1, 2, the switch 10 is opened. With the switch 7 turned to the position B, the terminal 6 is connected to ground, the switches 4, 5 are turned to the position B and only the terminal 3 is available for input. With the switch 7 turned to the position A, the level of the terminal 6 is a power potential via a resistor 9 from the power terminal 8. The switches 4, 5 are turned to the position A and the S-VHS video input gate is obtained, where input is available for the terminals 1, 2.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a 5-VHS video input terminal and a composite video input terminal (
The present invention relates to a video input switching circuit for a television receiver equipped with both a composite video signal input terminal for normal color signals and luminance signals.

2. Description of the Related Art In recent years, the number of television receivers equipped with a 5-VHS video input terminal has been increasing, but composite video input terminals are still often used.

Hereinafter, a conventional 5-VHS video image input twisting circuit will be described with reference to the drawings.

FIG. 2 shows the circuit configuration of a conventional 5-VHS video image input twisting circuit.

In Fig. 2, 21 is a 5-VHS color signal input terminal used for connection with a 5-VH6 device and inputs a color signal, and 22 is a 5-VHS color signal input terminal used when connecting a 5-VHS device and inputs a luminance signal.
This is a VHS brightness signal input terminal. 23 is a composite video input terminal for inputting a normal composite video signal. 24 is 5-
This is a color signal changeover switch that changes the color signal required only when inputting VHS video. 25, a luminance signal from the 5-VHS luminance signal input terminal 22 and a composite video input terminal 23
A brightness signal selection switch that switches the composite video signal from. 26 is a changeover switch control terminal for controlling the color signal changeover switch 24 and the luminance signal changeover switch 25.

27 is a video changeover switch for switching between the brightness signal from the 5-VHS brightness signal input terminal 22 and the composite video signal from the composite video input terminal 23; 28 is a power supply terminal; and 29 is a pull-up resistor.

The operation of the circuit connected as described above will be explained below.

When the user selects the video changeover switch 27 to the A side, what happens to the changeover switch control terminal 26? t[terminal 28
The potential becomes the potential of the power supply terminal 28 via the pull-up resistor 29. At this time, the color signal changeover switch 24 and the luminance signal changeover switch 25 are closed to the A side. Therefore, 5
The -Vl-IS color signal input terminal 21 and the 5-VHS luminance signal input terminal 22 are in a state where they can be operated manually. At this time, the composite video input terminal 23 is open and cannot be manually operated.

Also, when the video changeover switch 27 is closed to the B side,
The changeover switch control terminal 26 is grounded, and the color signal changeover switch 24 and brightness signal changeover switch 25 are connected to B.
Closed to the side. The color signal changeover switch 24 is in an open state, and the luminance signal changeover switch 25 is closed toward the composite video input terminal 23 side. In other words, by operating and selecting the video changeover switch 27 by the user, the 5-VH
SH5 video input This is used to set the combined video input.

Problem to be Solved by the Invention Conventionally, whether to use the 5-VHS video input terminals 21, 22 or the composite video input terminal 23 has been determined by the user operating the video changeover switch 27 and determining the set state. 5-VH6 video input or composite video input is determined.

Here, when used as the frequently used composite video input terminal 23, there is a problem in that the operation of the video changeover switch increases and the operation is complicated compared to a conventional television receiver with only a composite video input terminal. There was a point.

The present invention provides a television receiver having both a 5-VHS video input terminal and a composite video input terminal with the same simple operation as that of a conventional composite video input terminal only.

Means for Solving the Problems The 5-VHS video input switching circuit of the present invention provides a 5-VHS video input switching circuit.
By providing an interlocking switch on the S video input terminal and configuring the circuit so that the video changeover switch operates only when a device is connected to the 5-VHS video input terminal, the video changeover switch can be used when only the composite video input terminal is used. It is characterized by not requiring any operations.

Function The 5-VHS video input switching circuit of the present invention
An interlocking switch is provided on the S video input terminal.

5-When a device is connected to the VHS video input terminal, this interlock switch is opened and 1. By adopting a circuit configuration in which the video changeover switch operates, users who only have a composite video input terminal do not need to operate the video changeover switch, allowing easy operation similar to that of conventional television receivers with only a composite video input terminal. This is what we provide.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows the circuit configuration of a 5-VHS video input switching circuit in an embodiment of the present invention.

In Figure 1, 1 is the 5-VHS color signal input terminal used when connecting to a 5-VHS device and inputs the color signal, and 2 is the 5-VHS color signal input terminal.
-Used when connecting a VHS device and inputting the brightness signal 5-
Vl-13 is a luminance signal input terminal. 3 is a composite video input terminal for inputting a composite video signal, 4 is a color signal changeover switch for switching the color signal, and 5 is a terminal for connecting the luminance signal of the 5-VHS luminance signal nested terminal 2 and the composite video input terminal 3. This is a brightness signal changeover switch that changes the composite video signal. 6 is a changeover switch control terminal for controlling the color signal changeover switch 4 and the luminance signal changeover switch 5. Reference numeral 7 denotes a video changeover switch which the user operates to select between the 5-VHS video input terminals 1 and 2 or the composite video input terminal 3.

8 is a power supply terminal, 9 is a pull-up resistor, 1o is 5-VHS
This is a 5-VHS input terminal interlocking switch with a structure in which the switch is opened when a device is connected to the 5-VHS video input terminals 1 and 2 in conjunction with the connection of the device to the video input terminal.

The operation of the circuit configured as described above will be explained below.

If no device is connected to 5-VHS color signal input terminal 1 and 5-VHS brightness signal input terminal 2, 5-VHS
The input terminal interlocking switch 10 is closed. Therefore, the changeover switch control terminal 6 is in a grounded state, and at this time, the color signal changeover switch 4 and the luminance signal changeover switch 5 are fixed to the B side, and only the composite video input terminal 3 can be operated manually. Here, regardless of whether the video changeover switch 7 is set to the A side or the B side, the changeover switch control terminal 6 remains grounded, and only the composite video input terminal 3 can be input.

When devices are connected to the 5-VHS color signal input terminal 1 and the 5-VHS luminance signal input terminal 2, the 5-VHS input terminal interlocking switch 10 is opened. When the video changeover switch 7 is set to the B side, the changeover switch control terminal 6 is grounded, the color signal changeover switch 4 and the luminance signal changeover switch 5 are closed to the B side, and only the composite video input terminal 3 is input. It becomes possible. Further, when the video changeover switch 7 is set to the A side, the changeover switch control terminal 6 is connected to the power supply terminal 28 via the pull-up resistor 9 and becomes the potential of the power supply terminal 2. and 1
The color signal changeover switch 4 and the brightness signal changeover switch 5 are closed to the A side, and the 5-VHS color signal input terminal 1 and the 5-VHS brightness signal input terminal 2 are in a state where they can be input, which means 5-VHS video input. state.

Effects of the Invention As described above (B), the 5-VHS video manual switching circuit of the present invention is a 5-V video input terminal connected to the 5-VHS video input terminal, the VHS color signal input terminal, and the 5-VHS brightness signal input terminal.
By providing an H6 input terminal interlocking switch, 5-V
The video selection switch becomes operational only when the HS input nested terminal is connected, and if no device is connected, the composite video input terminal will be set regardless of the setting of the video selection switch. . Therefore, when only the composite video input terminal is used, the switching operation of the video changeover switch becomes unnecessary, and the user can be provided with the same operation as a conventional television receiver having only the composite video terminal.

[Brief Description of the Drawings] Fig. 1 is a circuit configuration diagram of a 5-VHS video input switching circuit according to an embodiment of the present invention, and Fig. 2 is a circuit diagram of a conventional 5-VHS video input switching circuit.
FIG. 3 is a circuit configuration diagram of a video input switching circuit. 1...5-VHS color signal input terminal, 2...
・5-VHS brightness signal input terminal, 3... Composite video input terminal, 4... Color signal changeover switch,
5...Brightness signal changeover switch, 7...
...Video changeover switch, 10...5-VH! 5
Input terminal interlocking switch.

Claims (1)

[Claims] It is equipped with both a composite video input terminal and an S-VHS video input terminal, and is provided with a changeover switch to select either one of the terminals, and a changeover switch that is linked to the connection/disconnection of equipment to the S-VHS video input terminal. Provided, S-VHS
An S-VHS video input switching circuit that prioritizes and selects the composite video input terminal when no device is connected to the video input terminal.