JPH0756541Y2 - RF modulator with built-in selector switch - Google Patents

Description

[Detailed description of the device] [Industrial applications]

The present invention is an RF modulator that converts video and audio signals such as VTR into TV signals, and an RF switch that incorporates an RF switch that switches between a TV broadcast signal from a broadcasting station and an RF modulated signal from the RF modulator.
It relates to a modulator.

[Problems to be solved by conventional techniques and devices]

A case where the conventional VTR 21 is used by being connected to the general TV 18 will be described with reference to FIG. In Figure 4, VTR21 is RF modulator 2
2. Built-in power supply 24 of RF modulator 22, video signal source (playback video signal) 25, audio signal source (playback audio signal) 26, VTR / TV mode switch 27, channel switch 28, RF switch 29 Among them, the RF modulator 22, the channel changeover switch 28, and the RF switch 29 are built in the shield case 30. Also, the RF modulator 22 that modulates the carrier with the video signal of the VTR 21 and converts it into a TV signal is
At the time of R reproduction, power is supplied from the power supply 24 at the same time as input is received from the video signal source 25 and the audio signal source 26. Therefore, when playing VTR, VTR / TV mode selector switch
When 27 is turned on, power is supplied from the power supply 24 to the RF modulator 22, and the RF switch 29 is turned off. One end of the RF switch 29 is connected to the VTR tuner 34 and the external antenna 35, and is also connected to the antenna terminal 36 of the external general TV 18. The power supply 24 is turned on when the VTR / TV mode selection switch 27 is turned on. The RF switch 29 is turned off by the power supplied from the antenna terminal 36, and the broadcast signal from the antenna 35 is not input to the antenna terminal 36, but only the TV signal from the RF modulator 22 is input. At this time, the channel changeover switch 28 is selected to be either low or high of an empty channel in the area. Next, when receiving broadcast video, turn off the VTR / TV mode selector switch 27 to stop the power supply from the power supply 24, and
The output of the modulator 22 is stopped, and the RF switch 29 is turned on to input the broadcast signal from the antenna 35 to the antenna terminal 36. The difference between the case where the AV television 33 is connected to the conventional VTR 21 and the case where the general TV 18 is connected to the conventional VTR 21 described above will be described with reference to FIG. The AV television 33 has a video input terminal 31 and an audio input terminal 32, the video input terminal 31 is connected to the video signal source 25 in the VTR 21, and the audio input terminal 32 is also connected to the audio signal source 26. ing.
Furthermore, the AV television 33 has a built-in AV / TV built-in switch 37, which receives an input from the antenna terminal for receiving broadcast signals, and inputs from the video signal source 25 and audio signal source 26 (AV signal) during VTR playback. It is necessary to perform the switching for receiving by the AV / TV built-in switch 37. When connecting the AV television 33, it is necessary to switch the VTR / TV mode switch 27 to switch between VTR playback and broadcast reception, and also switch the AV / TV built-in switch 37. There is a complicatedness that must be given, and accordingly, a technical problem to be solved in order to overcome this deficiency arises, and the present invention aims to solve the problem.

[Means for Solving the Problems]

The present invention has been proposed to achieve the above object, and is an R converter for converting VTR video and audio signals into TV signals.
F modulator, off-through type RF switch for switching between RF signal and antenna input, 2 circuit 3 position selector switch,
The RF modulator, the RF switch, and a shield case for accommodating the two-circuit, three-position changeover switch. The two-circuit, three-position changeover switch is turned on and off by a VTR / TV mode changeover switch of a VTR to make a VTR mode. A power supply circuit for supplying power to the RF modulator and the RF switch is sometimes connected to an RF output channel switching circuit, and the two-circuit / three-position switching switch is connected to the power supply circuit and the RF circuit in the first position and the second position. The modulator and the RF switch are turned on, the power supply circuit is disconnected at the third position, and the RF power is supplied at the first position and the second position.
An RF converter with a built-in switch is formed so that the output channels are switched.

[Action and effect]

When connecting a VTR and a general TV, the power source / channel switching switch is set to the first position or the second position to set the output channel to low or high. In this state, like the conventional RF modulator, VT
When the VTR / TV mode selector switch of R is switched to VTR mode, power is supplied to the RF modulator and the RF switch opens, and the VTR is set to the playback state by matching the general TV channel to the low or high setting channel. The video image is thereby reproduced. Also, when the VTR / TV mode selector switch is switched to TV mode, the RF modulator stops and RF
Since the switch is closed and the antenna line is connected,
Broadcast images are displayed by adjusting the TV channel to an arbitrary broadcast channel. When an AV television is used, the power source / channel switching switch is set to the third position. At this time, the RF switch is turned on, the signal from the antenna is connected to the AV television, and the RF modulator does not operate. Furthermore, since the video signal source and the audio signal source are directly connected to the AV television, the AV television
When watching either the VTR playback signal or the broadcast signal, it is possible to switch by simply operating the AV / TV built-in switch without operating the switch inside the VTR.

【Example】

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. First
In the figure, the VTR 1 has a built-in power source switching / channel switching switch 3 consisting of an RF modulator 2 and 2 circuit 3 position switching switches, a power source 4, a video signal source 5 and an audio signal source 6, and also serves as the above power source switching. Channel selector switch 3 is VTR
Of the off-through type RF switch 9 for switching on / off the power supply of the RF modulator 2 for converting the video and audio signals of the above into the TV signal and switching between the low and high channels and switching between the RF signal and the antenna input. Turn the power on and off.
On the other hand, the RF modulator 2 has a power source 4 outside the shield case 10,
It is connected to the video signal source 5 and the audio signal source 6, and the power supply to the RF modulator 2 and the RF switch 9 can be turned on / off by the power source / channel switching switch 3. Further, the video signal source 5 and the audio signal source 6 are further connected to the AV television 13 via a video input terminal 11 and an audio input terminal 12 provided in the AV television 13. Thus, one end of the RF switch 9 is connected to the VTR tuner 14 outside the shield case 10 and the antenna 15 outside the VTR 1, and the other end of the RF switch 9 is connected to the output side of the RF modulator 2 together with the antenna. AV television 13 via terminal 16
When the RF switch 9 is turned on, the antenna 15 is connected to the AV television 13 via the RF switch 9 and the antenna terminal 16. At this time, the power source switching / channel switching switch 3 is switched to the C position (third position) in FIG. 3 described later so that the RF switch 9 is turned on. When the general TV 18 is connected, the power source switching / channel switching switch 3 is switched to the position a (first position) or position b (second position) in FIG. The power supply / channel changeover switch 3 is a two-circuit three-position changeover switch in which the channel changeover switch 8 and the power supply changeover switch 19 are integrated, and the output frequency of the RF modulator 2 is the low channel at the position a. Switch to high channel at position b. Further, the power source 4 is connected to the RF modulator 2 and the RF switch 9 at the positions A and B, and the power source 4 is disconnected at the position C. The power supply 4 is turned on / off by the VTR / TV mode changeover switch 7 of the VTR 1, turned on in the VTR mode and turned off in the TV mode. Therefore, at the positions of A and B, VTR / TV
When the mode selector switch 7 is switched to the VTR mode, the RF modulator 2 is activated and the RF switch 9 is in the disconnected state. On the other hand, in the TV mode, the power supply 4 is turned off, the power supply is cut off, the RF modulator 2 is stopped, the RF switch 9 is closed, and the input radio wave from the antenna 15 is supplied to the television. Further, in the position of C (the third position), the power source changeover switch 19 is turned off, and the VTR / TV mode changeover switch 7
Since the line of the power source 4 is disconnected regardless of the switching state of the RF power source, the RF modulator 2 is in the stopped state and the RF switch 9 is in the closed state. In addition, in the case of VTR playback using the general TV 18, depending on whether the channel is set to low or high, it is the operation of (a) or (b) respectively, and the VTR / TV mode switch When 7 is switched to the VTR mode, power is supplied to the RF modulator 2 and the RF switch 9 is turned off, and the VTR signal of the low or high channel is output via the antenna terminal 16 and the AV television is turned on. When (13) is used, the operation is (c). At this time, the RF switch 9 is turned on, and the antenna 15 is connected to the AV television 13 via the antenna terminal 16 and the power source is switched as described above. The switch 19 is turned off, and the RF modulator 2
Does not work. When the AV television 13 is used, the power source changeover channel 19 is turned off by initially setting the power source changeover channel changeover switch 3 to the third position, that is, the position of (c), and the RF modulator 2 and The RF switch 9 is disconnected from the power supply 4. Therefore, since the RF switch 9 is normally closed regardless of the state of the VTR / TV mode changeover switch 7 of the VTR 1, unlike the conventional RF modulator, the VTR / T
Even when the V mode selector switch 7 is switched to the VTR mode, it does not hinder general broadcast reception,
VTR1 Whether you are watching the playback signal or the broadcast signal, the VTR1
It is not necessary to operate the VTR / TV mode selector switch 7
・ It can be switched only by operating the TV built-in selector switch 17.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG.
FIG. 3 is a block diagram showing a case where a general TV is connected to a VTR in the embodiment of the present invention shown in FIG.
FIG. 4 is a diagram showing the arrangement and operation relationship of each element constituting the power source / channel switching switch in the embodiment of the present invention shown in FIG. 1, and FIG. 4 is a conventional VTR to which a general TV is connected. Fig. 5 shows the conventional block diagram
It is a block diagram when connecting an AV television to a VTR.

[Explanation of symbols]

 1 …… VTR, 2 …… RF modulator 3 …… Power source / channel changeover switch 4 …… Power source, 5 …… Video signal source 6 …… Sound signal source 7 …… VTR / TV mode changeover switch 8 …… Channel Changeover switch 9 …… RF switch, 10 …… Shield case 11 …… Video input terminal, 12 …… Audio input terminal 13 …… AV television 14 …… VTR tuner 15 …… Antenna, 16 …… Antenna terminal 17 …… AV / TV built-in switch 18 …… General TV, 19 …… Power switch

Claims (1)

[Scope of utility model registration request] 1. An RF modulator for converting a video and audio signal of a VTR into a TV signal, an off-through type RF switch for switching between an RF signal and an antenna input, a 2-circuit 3-position changeover switch, the RF modulator, It is composed of an RF switch and a shield case for accommodating the 2-circuit 3-position changeover switch. The 2-circuit 3-position changeover switch is turned on / off by a VTR / TV mode changeover switch of a VTR, and the R is set in the VTR mode.
Power supply circuit for supplying power to the F modulator and RF switch and R
The F circuit is connected to the F output channel changeover circuit, and the 2 circuit 3 position changeover switch connects the power supply circuit to the RF modulator and the RF switch at the first position and the second position, and the power supply circuit at the third position. Is cut off, and at the first position and the second position
An RF modulator with a built-in changeover switch, which is formed so that the RF output channels are changed over.