JPH0546388Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The invention is applicable to audiovisual devices (hereinafter referred to as AV devices) such as SVHS video tape recorders and video disc players.
The present invention relates to a composite video signal output device used for.

[Conventional technology]

2. Description of the Related Art In recent years, some AV devices such as video tape recorders and video disk players are known to adopt the so-called SVHS method in order to obtain high-quality playback images. This SVHS method AV
In the device, as shown in FIG.
The output signal of transistor Tr ₁ , resistors R ₁ , R ₂ ,
A 4-terminal jack ₃ constituting a so-called S terminal is connected to a luminance signal output circuit 4 consisting of a capacitor C1.
The luminance signal is output independently from the luminance signal output terminal 3a. Similarly, the output signal of the color signal circuit 2 is transmitted through the transistor Tr ₂ , the resistors R ₃ , R ₄ ,
Through the color signal output circuit 5 consisting of capacitor _C2 ,
The color signals are output independently from the color signal output terminal 3b of the four-terminal jack 3. The other two terminals in the four-terminal jack 3 are ground terminals, that is, GND terminals 3c and 3d.

The above-mentioned AV device is connected to a monitor television, which also has a 4-terminal jack, through a connecting cable that has 4-terminal plugs at both ends.

[Problem that the invention attempts to solve]

However, with the above-mentioned conventional structure, it is not possible to connect to an SVHS AV device unless the television serving as a monitor is compatible with the SVHS system. In other words, if the TV only has a pin jack video input terminal and does not have a 4-terminal jack, it will not be able to connect to the AV device and will not be able to play the AV device. There is a problem with this.

[Means for solving problems]

The composite video signal output device of the present invention is
In order to solve the above problem, a connection means having independent output terminals for connection with an external circuit is provided, and each output terminal has a luminance signal and a color signal output from the luminance signal output circuit. In an output device where the color signals from the circuit are separately supplied,
Between the luminance signal output circuit and the chrominance signal output circuit, a signal from either the luminance signal output circuit or the chrominance signal output circuit is supplied to the other output circuit, and the luminance signal and the chrominance signal are mixed. A signal mixing means for producing a composite video signal is provided, and the signal mixing means is provided with a switching means for opening and closing a signal transmission path in the signal mixing means.

[Effect]

According to the above configuration, when the switching means in the signal mixing means is turned off, the luminance signal and the color signal are individually supplied to the corresponding output terminals of the connection means through the luminance signal output circuit and the color signal output circuit. .

On the other hand, turn on the switching means of the signal mixing means.
, the signal from either the luminance signal output circuit or the color signal output circuit is supplied to the other output circuit,
The luminance and chrominance signals are mixed to create a composite video signal. Since this composite video signal is supplied to the output terminal corresponding to one of the output circuits in the connection means,
For example, by using a cable with a connection means mating with the connection means described above at one end and a pin plug at the other end, it is possible to supply a video signal to a TV that only has a video input terminal on the bin jack. be able to.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

As shown in FIG. 1, the AV device includes a luminance signal output circuit 14 consisting of a transistor Tr ₁₁ , resistors R ₁₁ , R ₁₂ and a capacitor C ₁₁ ;
A color signal output circuit 15 consisting of Tr ₁₂ , resistors R ₁₃ , R ₁₄ and a capacitor C ₁₂ , and a mixing circuit 17 which is a signal mixing means consisting of a capacitor C ₁₃ and a switch 16 constitute an S terminal and serve as a connection means. A composite video signal output device consisting of a four terminal jack 13 is provided.

The luminance signal circuit 11 is connected to the base of the transistor Tr ₁₁ in the luminance signal output circuit 14 . The collector of the transistor _Tr11 is supplied with a power supply voltage (+ _Vcc ), and the emitter is grounded via a resistor _R11 . Further, the emitter is connected to the luminance signal output terminal _13a of the four-terminal jack 13 via a resistor _R12 and a capacitor C11.

On the other hand, the transistor Tr ₁₂ in the color signal output circuit 15 has its base connected to the color signal circuit 12, its collector supplied with the power supply voltage (+ _Vcc ), and its emitter grounded via a resistor _R13 . Furthermore, the emitter of transistor Tr ₁₂ is
It is connected to the color signal output terminal 13b of the four-terminal jack ₁₃ via a resistor _R14 and a capacitor C12. The other terminals in the four-terminal jack 13 are GND terminals 13c and 13d.

In addition, the emitter of the transistor Tr ₁₂ has
One end of a capacitor C ₁₃ of the mixing circuit 17 is connected, and the other end of the capacitor C ₁₃ is connected to one fixed terminal 16 of a switch 16 which is a switching means.
connected to b. The other fixed terminal 16a of the switch 16 is an open terminal, and the movable terminal 1
6c is connected to a connecting portion 22 between the resistor _R12 and the capacitor _C11 in the luminance signal output circuit 14.

The luminance signal output circuit 14 and the color signal output circuit 15 are connected to a resistance of 75 Ω by resistors _R12 and _R14 .
There is an imbalance.

A 4-terminal plug/pin plug conversion cable 18 as shown in FIG. 2 is used to connect the 4-terminal jack 13 of this output device to a television having a pin jack video input terminal. This 4
The terminal plug/pin plug conversion cable 18 has a terminal 19a corresponding to the luminance signal output terminal 13a of the four-terminal jack 13 and a color signal output terminal 1 at one end.
Terminal 19b corresponding to 3b, GND terminal 13c,
4 having terminals 19c and 19d corresponding to 13d.
A terminal plug 19 is provided, and a pin plug 21 having a pin terminal 21a and a shield terminal 21b is provided at the other end, and the four-terminal plug 19 and the pin plug 21 are connected by a shield wire 20. There is.

In the above configuration, when outputting the luminance signal and the color signal independently from the 4-terminal jack 13, that is, when connecting an SVHS compatible TV to the 4-terminal jack 13, switch 16 of the mixer circuit 17 is turned on. Leave it OFF. And above 4
The terminal jack 13 and the four-terminal jack of the television are connected by a cable having four-terminal plugs corresponding to the four-terminal jack 13 at both ends.

In this state, the luminance signal output from the luminance signal circuit 11 is impedance-converted by the transistor Tr ₁₁ of the luminance signal output circuit 14, and is sent to the luminance signal output terminal 13a of the four-terminal jack 13 through the resistor R ₁₂ and capacitor C ₁₁ . Supplied.
Furthermore, the color signal output from the color signal circuit 12 is
Similarly, the transistor of the color signal output circuit 15
The impedance is converted by Tr ₁₂ , and the signal is supplied to the color signal output terminal 13b of the four-terminal jack 13 through a resistor R ₁₄ and a capacitor C ₁₂ . The luminance signal and color signal are then supplied to the television via the cable.

On the other hand, when outputting a composite video signal in which a luminance signal and a color signal are mixed from the 4-terminal jack 13, the switch 16 of the mixer circuit 17 is turned on.
Leave it ON. Then, by fitting the 4-terminal plug 19 of the 4-terminal plug/pin plug conversion cable 18 into the 4-terminal jack 13, and fitting the pin plug 21 into the pin jack that is the video input terminal of the TV, the AV device and the TV are connected. Connecting.

In this state, the color signal output from the color signal circuit 12 is impedance-converted by the transistor Tr ₁₂ and then supplied to the color signal output terminal 13b of the four-terminal jack 13, and is also supplied to the capacitor _C13 of the mixer circuit 17. and a switch 16 to a connecting portion 22 between a resistor R ₁₂ and a capacitor C ₁₁ in the luminance signal output circuit 14 . As a result, the color signal and the luminance signal are added in the luminance signal output circuit 14, and a composite video signal is output from the luminance signal output terminal 13a of the four-terminal jack 13. This signal is then supplied to the television via the 4-terminal plug/pin plug conversion cable 18.

[Effect of idea]

The composite video signal output device of the present invention is
As described above, connection means each having independent output terminals for connection to an external circuit is provided, and each output terminal receives a luminance signal from the luminance signal output circuit and a color signal from the color signal output circuit. In the output device to which the luminance signal output circuit and the chrominance signal output circuit are individually supplied, a signal from one of the luminance signal output circuit and the chrominance signal output circuit is supplied to the other output circuit. A signal mixing means is provided for mixing a luminance signal and a color signal to produce a composite video signal, and the signal mixing means is provided with a switching means for opening and closing a signal transmission path in the signal mixing means. It is the composition.

Therefore, for example, a TV serving as a monitor
Even if the device does not have an S terminal jack that supports the SVHS system and only has a pin jack video input terminal, it must be connected to an SVHS system AV device that only has the S terminal described above. This has the effect of improving the versatility of the AV device.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing one embodiment of the present invention;
The figure is a schematic perspective view of a 4-terminal plug/pin plug conversion cable used to connect the composite video signal output device shown in Fig. 1 to a television having a pin jack video input terminal, and Fig. 3 shows a conventional example. It is a circuit diagram. 11... Luminance signal circuit, 12 color signal circuit, 1
3 is a four-terminal jack (connection means), 13a is a luminance signal output terminal (output terminal), 13b is a color signal output terminal (output terminal), 14 is a luminance signal output circuit, 1
5 is a color signal output circuit, 16 is a switch (switching means), 17 is a mixer circuit (signal mixing means), 18 is a 4-terminal plug/pin plug conversion cable, Tr ₁₁ and Tr ₁₂ are transistors, and R ₁₁ to _{R 14} are resistors. , C ₁₁ to C ₁₃ are capacitors.

Claims (1)

[Claims for Utility Model Registration] Connecting means having independent output terminals for connection to an external circuit is provided, and each of the above output terminals receives a luminance signal from the luminance signal output circuit and a color signal from the color signal output circuit. In the output device to which the color signals of 1 and 2 are individually supplied, a signal from one of the luminance signal output circuit and the color signal output circuit is connected to the other output circuit between the luminance signal output circuit and the chrominance signal output circuit. A signal mixing means is provided for producing a composite video signal by mixing the luminance signal and the color signal, and the signal mixing means is provided with a switching means for opening and closing a signal transmission path in the signal mixing means. A composite video signal output device characterized in that: