JPH04252678A - Signal line connection structure for signal recording/ reproducing device - Google Patents

Abstract

PURPOSE:To obviate troublesome mode switching by detecting automatically a fact that a video signal is connected to a video signal output terminal, by a detecting means, and selecting an antenna input in response to a connection detecting signal. CONSTITUTION:In the case a video signal line 20 is connected to a video output terminal 7, a signal of a low level is always outputted from a switching circuit 22. Also, switches 9a, 9b of a selecting circuit 9 always connect a recording/ reproducing circuit 4, the terminal 7, and an audio signal output terminal 8, and a switch 9c always connects a receiving antenna 10 and a television set 11. In such a way, in the case the signal line 20 is connected to the terminal 7, a through-path extending from the antenna 10 to the television set 11 can always be formed, and accordingly, it becomes unnecessary to execute a troublesome operation for switching a reproducing mode to an antenna input mode by an RF converter.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to a signal line connection structure for signal recording and reproducing devices such as video tape recorders (hereinafter referred to as VTRs) and CD players, and in particular, the present invention relates to signal line connection structures for signal recording and reproducing devices such as video tape recorders (hereinafter referred to as VTRs) and CD players. This invention relates to a circuit that controls switching to video.

0002

2. Description of the Related Art When the VTR was first developed, video and audio signals reproduced from a signal recording medium were converted to the same frequency as broadcast radio waves and then applied to the antenna input terminal of a television receiver. And recently, VT
Television receivers to which video signals reproduced by R (R, G, B signals) and audio signals can be directly input have become commercially available. For this reason, VT
R also has an RF converter, video signal and An audio signal output terminal is provided.

FIG. 2 is a block diagram showing a state in which such a VTR and a television receiver are connected.

Referring to the figure, a VTR includes a mechanism section 2 for running/stopping a cassette tape 1, a control circuit 3 for controlling the mechanism section 2, and recording and reproducing video signals and audio signals. It includes a recording/reproducing circuit 4, an RF converter 5, a switch 6, a video signal output terminal 7, an audio signal output terminal 8, and a selection circuit 9.

The audio reproduction circuit 4 reproduces the video signal recorded on the cassette tape 1 and supplies the reproduced video signal to the selection circuit 9.

The selection circuit 9 includes switches 9a, 9b, 9c.
including. The switch 9a has an input side connected to the video signal output of the recording/reproducing circuit 4, and an output side connected to the video signal output terminal 7. The switch 9b has an input side connected to the audio signal output of the recording/reproducing circuit 4, and an output side connected to the audio signal output terminal 8. The switch 9c is
The input side is connected to the receiving antenna 10 and the RF converter 5, respectively, and the output side is connected to the television receiver 11. Each of the switches 9a and 9b connects the recording/reproducing circuit 4 and the RF converter 5 in response to turning on the switch 6. Further, the switch 9c connects the RF converter 5 and the television receiver 11 in response to the ON of the switch 6. Note that FIG. 2 shows the connection state when the switch 6 is in the ON state.

[0007] The RF converter 5 converts the video signal and audio signal input from the recording/reproducing circuit 4 through the selection circuit 9 into the frequency of broadcast radio waves, and supplies the frequency to the television receiver 11.

The television receiver 11 has an antenna input terminal 12, a video signal input terminal 13, and an audio signal input terminal 14. The antenna input terminal 12 is
It is connected to the RF output of the selection circuit 9, the video signal input terminal 13 is connected to the video signal output terminal 7 of the VTR, and the audio signal input terminal 14 is connected to the audio signal output terminal 8 of the VTR. Therefore, this television receiver 11 can form a screen using the RF signal frequency-converted by the RF converter 5 or the signals input from the video input terminal 13 and the audio input terminal 14.

Next, the operation in the case of the connection configuration shown in FIG. 2 will be explained. When the VTR is set to playback mode, the switch 6 is turned on, the RF converter 5 is activated, and the switch 9c of the selection circuit 9 is turned on.
The contact point is turned to the RF converter 5 side. In this way, the RF converter 5 and the television receiver 11 are connected. Then, the video signal and the audio signal are converted into RF signals by the RF converter 5, and the converted R
The F signal is applied to the television receiver 11 through the antenna input terminal 12. When the switch 6 is turned on, the recording/reproducing circuit 4 is not connected to the output terminals 7 and 8 by the selection circuit 9, so that the frequency is converted by the RF converter 5 to the television receiver 11. Only the signals that are input are input. Note that selecting the output of the RF converter and not selecting the signals of output terminals 7 and 8 is as follows.
This is because the output of the RF converter can be used in either of the two types of TV receivers mentioned above.

As explained above, when the RF converter 5 is used in the reproduction mode, the receiving antenna 10
Since there is no connection between the receiver and the television receiver 11, it is not possible to obtain images using broadcast radio waves. To obtain an image using broadcast radio waves, turn off the switch 6 provided on the VTR, move the switch 9c of the selection circuit 9 to the antenna 5 side, and connect the receiving antenna 10 and the antenna input terminal 12 of the television receiver 11. , and then change the channel on the television receiver 11. Note that the switch 6 and channel switching operations can also be performed by remote control.

[0011]

[Problem to be solved by the invention] However, VTR
To view broadcast images during playback, press switch 6 or the remote control switch to R.
It is necessary to perform the troublesome operation of switching from the output mode of the F converter 5 to the mode for selecting the antenna input.

Therefore, the present invention provides a signal line for a signal recording and reproducing apparatus that can eliminate the trouble of switching from the output mode of an RF converter to the antenna input mode in order to view images by broadcast radio waves when playing back a video. The purpose is to provide a connection structure.

[0013]

[Means for Solving the Problems] To achieve the above object, the present invention provides a reproduction circuit for reproducing video signals and audio signals recorded on a signal recording medium, and a video signal and audio signals reproduced by the reproduction circuit. A signal recording and reproducing device comprising an RF converter that converts a signal to the same frequency as a broadcast radio wave, and an output terminal for directly providing the video signal and audio signal reproduced by the reproducing circuit to a television receiver, It has the following characteristics. That is, a detection means for automatically detecting a connection between the output terminal and a television receiver, a signal line connected to the RF converter and a receiving antenna for receiving broadcast radio waves, and a signal line to the output terminal. and means for selecting the output of the receiving antenna from the output of the RF converter and the output of the receiving antenna in response to the detection signal and providing the selected output to the television receiver.

[0014]

[Operation] According to the present invention, when a signal line is connected to the output terminal, the connection detection means automatically detects the connection to the output terminal. Then, in response to the automatically detected signal, a path for receiving broadcast radio waves from the receiving antenna is formed. By doing this, when the output terminal is connected to a television receiver, a signal path from the receiving antenna to the television receiver is automatically formed, so the output from the antenna input and the RF converter can be switched. You can eliminate the hassle.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing an embodiment of the present invention. Referring to the same figure, the difference from the above-mentioned FIG. The switching circuit 22 generates a control signal for stopping the operation of the selection circuit 5 and turning on the switch 9c of the selection circuit 9. Note that circuits similar to those in FIG. 2 are denoted by the same reference numerals, and explanations thereof will be omitted as appropriate.

The switch 21 is attached to the video signal output terminal 7 via an insulator so that when the video signal line 20 is connected to the video signal output terminal 7, the switch 21 is electrically connected to the ground. The switching circuit 22 includes a transistor Tr1
, Tr2, and resistors R1 to R4. The switching circuit 22 is configured such that even if the switch 6 is in the ON state, when the switch 21 is turned on, the transistor Tr1 and the transistor Tr2 are turned off in sequence.

The operation of the VTR signal line connection structure shown in FIG. 1 will be described below. When the video signal line 20 is connected to the video output terminal 7, the switching circuit 22
A low level signal is always output from. As a result, R
The F converter 5 does not perform any frequency conversion operation. Further, switches 9a and 9b of the selection circuit 9 always connect the recording/reproducing circuit 4 to the video signal output terminal 7 and the audio signal output terminal 8, and the switch 9c always connects the receiving antenna 10 and the television receiver 11. Connecting.

In this way, when the video signal line 20 is connected to the video output terminal 7, the receiving antenna 10
A through path from the TV receiver 11 to the TV receiver 11 can be formed at all times. Therefore, in playback mode,
There is no need to perform the troublesome operation of switching from the output mode of the RF converter to the input mode of the receiving antenna when it is desired to view images by broadcast radio waves.

[0019]

[Effects of the Invention] With the present invention as described above, the detection means automatically detects that the signal line is connected to the output terminal,
By selecting the antenna input in response to automatically detected signals, a through path is created from the receiving antenna to the television receiver. Therefore, the unique effect of eliminating the trouble of switching from the reproduction mode to the antenna input mode using the RF converter can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a block diagram showing a connection between a conventional VTR and a television receiver.

[Explanation of symbols]

4 Recording/playback circuit 5 RF converter 6 Switch 7 Video signal output terminal 8 Audio signal output terminal 9 Selection circuit 10 Receiving antenna 11 Television receiver 12 Antenna input terminal 13 Video input terminal 14 Audio input terminal 20 Video signal line 21 Switch 22 Switching circuit

Claims (1)

[Claims] 1. A reproduction circuit that reproduces video and audio signals recorded on a signal recording medium; an RF converter that converts the video and audio signals reproduced by the reproduction circuit to the same frequency as broadcast radio waves; In a signal recording and reproducing device equipped with an output terminal for directly giving a video signal and an audio signal reproduced by a reproduction circuit to a television receiver, a connection between the output terminal and the television receiver is automatically detected. a detection means, connected to the RF converter and a receiving antenna for receiving broadcast radio waves, and in response to a connection detection signal of a signal line to the output terminal, an output of the RF converter and an output of the receiving antenna. A signal line connection structure for a signal recording and reproducing apparatus, characterized in that the signal line connection structure includes means for selecting an output of a receiving antenna among the receiving antennas and providing the selected output to the television receiver.