JPH04326274A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To hear voices, which are inputted from an outside microphone, from the loudspeaker of a TV receiver without operating the voice mute circuit of the TV receiver even when a video signal is not transmitted to the TV receiver simultaneously with an audio signal inputted from the outside microphone at the magnetic recording and reproducing device which can transmit this audio signal to the TV receiver. CONSTITUTION:A signal detection circuit 20 detects the presence/absence of the video signal. When no video signal is detected, the test signal of a pseudo video signal is generated by a test signal generating circuit 16 and inputted through a switch 17 to a modulation circuit 18. This modulation circuit 18 simultaneously inputs the audio signal as well. The test signal and the audio signal are modulated at the modulation circuit 18 and inputted to a TV receiver 2 after mixing at a mixer 19. Thus, since a voice mute circuit 22 of the TV receiver 2 is not operated, the voices are outputted from the loudspeaker.

Description

[Detailed description of the invention]

[Object of the invention]

0002

[Industrial Application Field] The present invention relates to television (hereinafter referred to as TV).
The present invention relates to a magnetic recording/reproducing device having a built-in test signal generation circuit that generates a test signal used for channel adjustment on the receiver side.

0003

2. Description of the Related Art Today, video tape recorders (hereinafter referred to as VTRs) are being shipped which have a built-in test signal generation circuit for generating test signals used for channel adjustment on the TV receiver side. The structure of this VTR will be explained with reference to the drawings. FIG. 2 is a block diagram showing the structure of a VTR incorporating a conventional test signal generation circuit.

[0004] In FIG. 2, a television signal received by an antenna 10 is input to a distribution circuit 11 inside the VTR 1. This distribution circuit 11 divides the input television signal into two signals having the same amplitude and the same phase, and outputs the two signals. The distributed signals are input to the receiving circuit 12 and the mixer 19.

[0005] The receiving circuit 12 selects a signal of a desired channel from the input signals and outputs it to a video processing circuit 13 and an audio processing circuit 14. The video processing circuit 13 generates a video signal from the input signal and outputs it. Similarly, the audio processing circuit 14 generates an audio signal from the input signal,
Output. These video signals and audio signals are recorded by the recording and reproducing circuit 1.
5 is input. The recording/reproducing circuit 15 records the input signal on a recording medium such as a magnetic tape.

The recording and reproducing circuit 15 also has the function of reproducing already stored video and audio signals and outputting them to the video processing circuit 13 and the audio processing circuit 14, respectively. The audio signal generated by the microphone 24 is also input to the audio processing circuit 14 . The video processing circuit 13 and the audio processing circuit 14 perform various processing on the input signals and then output the signals. The video signal output from the video processing circuit 13 is input to the switch 17. Also, the audio processing circuit 1
The audio signal output from 4 is input to modulation circuit 18.

The switch 17 includes a test signal generating circuit 16.
The test signal output from is also input. This test signal is a signal used for channel adjustment on the TV receiver 2 side. Switching of the switch 17 is performed by a manual switch 23 attached to the wall of the VTR 1. Specifically, when the manual switch 23 is turned on, the test signal generation circuit 16 generates a test signal. At the same time, switch 17 selects the test signal. On the other hand, when the manual switch 23 is off, the test signal generation circuit 16 is in a rest state, and the switch 17 selects and outputs the video signal.

The output signal of switch 17 is input to modulation circuit 18 . The modulation circuit 18 modulates the output signal of the switch 17 together with the aforementioned audio signal, and outputs the modulated signal to the mixer 19. In addition to the output signal of the modulation circuit 18, the mixer 19 also receives the output signal of the distribution circuit 11 described above. The mixer 19 mixes these two signals and sends the mixed signal to the TV receiver 2.

The TV receiver 2 includes a video detection circuit 21 and an audio mute circuit 22. Video detection circuit 2
1 outputs a control signal for controlling the audio mute circuit 22 when no video signal is detected from the input signal. When this control signal is input, the mute circuit 22 cuts off the audio.

By the way, the above-mentioned modulation circuit 18 outputs an unmodulated signal when no video signal is input. At this time, V
When an audio signal is input from the microphone 24, which is an external device of the TR1, the modulation circuit 18 outputs a signal in which only the audio signal is modulated. This signal is sent to the TV via mixer 19.
When the video signal is input to the receiver 2, the video detection circuit 21 outputs a control signal to the mute circuit 22 since the video signal is not detected. Therefore, no sound is output from the TV receiver 2.

[0011] Based on the above, I decided to use a karaoke compatible VTR.
When connected to the TV receiver 2, the audio input from the microphone 24 can be heard from the speakers of the TV receiver 2 if there is a video signal. However, when the video disappeared, the audio input from the microphone 24 could not be heard from the speakers of the TV receiver 2.

0012

[Problem to be Solved by the Invention] As mentioned above, when a karaoke-compatible VTR is connected to a TV receiver equipped with a built-in video detection circuit and an audio mute circuit, if there is a video signal, the audio input from the external microphone will be detected. could be heard through the TV receiver's speakers. However, when the video disappears, the audio mute circuit is activated and the audio signal is muted, so there is a problem that the audio input from the microphone cannot be heard from the speakers of the TV receiver.

The present invention has been made in view of the above-mentioned problems, and it allows audio signals input from an external microphone to be
In a magnetic recording/reproducing device that can be sent to a TV receiver, even if the video signal is not sent to the TV receiver at the same time as the audio signal, the TV receiver's audio mute circuit will not operate and the audio input from the external microphone will not be activated. An object of the present invention is to provide a magnetic recording/reproducing device that can be heard through the speakers of a TV receiver.

[Configuration of the invention]

[0015]

[Means for Solving the Problems] The means of the present invention includes a reproducing means for reproducing video signals and audio signals from a recording medium on which the video signals and audio signals are recorded, a video signal generating means for generating the video signals, A selection means for selecting and outputting either the reproduced video signal or the video signal from the video signal generation means, and the video signal outputted from the selection means together with the audio signal are supplied, and the video signal is supplied with a broadcast frequency television signal. an RF modulator that outputs a video signal from the video signal generating means, which determines the presence or absence of the reproduced video signal, and when it is determined that the video signal is not being reproduced, the video signal is input to the RF modulator as a video signal. and video signal detection means for outputting a detection signal that controls the selection means so that the signal is selected, and the television receiver outputs audio even if the reproduction means does not reproduce the video signal. .

[0016]

[Operation] When there is a video signal, the selection means selects the video signal, and when there is no video signal, the selection means selects the test video signal. As a result, a test video signal, which is either a video signal or a pseudo video signal, is input to the television receiver, so the audio mute circuit inside the television receiver does not operate. Therefore, the audio signal output from the external audio signal generator is always output from the speakers of the television receiver.

[0017]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an embodiment.

In FIG. 1, a television signal received by an antenna 10 is input to a distribution circuit 11 inside a VTR 1. This distribution circuit 11 divides the input television signal into two signals having the same amplitude and the same phase, and outputs the two signals. The distributed signals are input to the receiving circuit 12 and the mixer 19.

The receiving circuit 12 selects a signal of a desired channel from the input signals and outputs it to the video processing circuit 13 and the audio processing circuit 14. The video processing circuit 13 generates a video signal from the input signal and outputs it. Similarly, the audio processing circuit 14 generates an audio signal from the input signal,
Output. These video signals and audio signals are recorded by the recording and reproducing circuit 1.
5 is input. The recording/reproducing circuit 15 records the input signal on a recording medium such as a magnetic tape.

The recording and reproducing circuit 15 also reproduces the already stored video signal and audio signal and outputs them to the video processing circuit 13 and the audio processing circuit 14, respectively. Audio processing circuit 1
4 also receives an audio signal generated by the microphone 24. The video processing circuit 13 and the audio processing circuit 14 perform various processing on the input signals and then output the signals. The video signal output from the video processing circuit 13 is sent to switch 1.
7 and the signal detection circuit 20. Further, the audio signal output from the audio processing circuit 14 is input to the modulation circuit 18.

The test signal generating circuit 16 is connected to the switch 17.
The test signal output from is also input. This test signal is a signal used for channel adjustment on the TV receiver 2 side. Switching of the switch 17 is performed by the output signal of the signal detection circuit 20. Specifically, when the signal detection circuit 20 does not detect a video signal, the switch 17 selects the test signal. At the same time, the test signal generation circuit 16 generates a test signal. On the other hand, if the signal detection circuit 20 detects a video signal, the switch 17
selects and outputs the video signal. The test signal generation circuit 16 then enters a rest state. Although various circuits are well known as circuits for detecting video signals, for example, a circuit that includes a synchronization signal detector and determines whether or not a synchronization signal is present in an input signal is common.

The output signal of switch 17 is input to modulation circuit 18 . The modulation circuit 18 modulates the output signal of the switch 17 together with the aforementioned audio signal, and outputs the modulated signal to the mixer 19. In addition to the output signal of the modulation circuit 18, the mixer 19 also receives the output signal of the distribution circuit 11 described above. The mixer 19 mixes these two signals and sends the mixed signal to the TV receiver 2.

The TV receiver 2 has a built-in video detection circuit 21 and an audio mute circuit 22. Video detection circuit 2
1 outputs a control signal for controlling the audio mute circuit 22 when no video signal is detected from the input signal. When this control signal is input, the audio mute circuit 22
cuts off the audio.

However, if the signal detection circuit 20 does not detect a video signal, the test signal is modulated as a pseudo video signal and sent to the TV receiver 2, so the audio mute circuit 22 does not operate. . As a result, even if no video signal is sent out from the video processing circuit 13, audio is output from the speakers of the TV receiver 2.

As described above, when the signal detection circuit 20 inside the VTR 1 does not detect a video signal, the test signal generation circuit 16 generates a test signal. This test signal is modulated together with the audio signal by the modulation circuit 18, and the mixer 19
The mixed signals are mixed and output to the TV receiver 2. The TV receiver 2 incorporates a video detection circuit 21 for detecting video signals and an audio mute circuit 22. And video detection circuit 21
If no video signal is detected, the audio mute circuit 22 mutes the audio. However, when there is no video signal, the VTR 1 outputs a test signal that is a pseudo video signal. As a result, the audio mute circuit 22 of the TV receiver 2 does not operate, and audio is always output from the speakers of the TV receiver 2.

[0026] From these things, a VTR compatible with karaoke,
In a TV receiver connected to this VTR, audio input from a microphone can be heard from a speaker of the TV receiver regardless of the presence or absence of an image.

In the embodiment described above, the output of the distribution circuit 11 and the output of the modulation circuit 18 are added together in the mixer 19 and supplied to the TV receiver 2, but the mixer 1
Distribution circuit 1 by changeover switch circuit instead of 9
1 and the output of the modulation circuit 18 may be alternatively selected and derived.

[0028]

As described above, when the signal detection circuit 20 inside the VTR 1 does not detect a video signal, the test signal generation circuit 16 generates a test signal. This test signal is modulated together with the audio signal by the modulation circuit 18, and the mixer 19
The mixed signals are mixed and output to the TV receiver 2. The TV receiver 2 incorporates a video detection circuit 21 for detecting video signals and an audio mute circuit 22. And video detection circuit 21
If no video signal is detected, the audio mute circuit 22 mutes the audio. However, when there is no video signal, the VTR 1 outputs a test signal that is a pseudo video signal. As a result, the audio mute circuit 22 of the TV receiver 2 does not operate, and audio can always be output from the speakers of the TV receiver 2.

[Brief explanation of drawings]

[Fig. 1] Block diagram showing the configuration of the present invention

[Figure 2] Block diagram showing the conventional configuration

[Explanation of symbols]

1...VTR 2...TV receiver 10...Antenna 11...Distribution circuit 12...Receiving circuit 13...Video processing circuit 14...Audio processing circuit 15...Recording/reproducing circuit 16...Test signal generation circuit 17...Switch 18...Modulation circuit 19...Mixer 20...Signal detection circuit 21...Video detection circuit 22...Audio mute circuit 24...Microphone

Claims (2)

[Claims] 1. Reproducing means for reproducing video signals and audio signals from a recording medium on which the video signals and audio signals are recorded, video signal generating means for generating video signals, and a reproduced video signal or from the video signal generating means. a selection means for selecting and outputting one of the video signals; an RF modulator to which the video signal output from the selection means is supplied together with the audio signal and outputting a television signal at a broadcast frequency; and an RF modulator for outputting a television signal at a broadcast frequency; The selection means determines the presence or absence of a video signal, and when it is determined that the video signal is not being reproduced, the video signal from the video signal generation means is selected as the video signal input to the RF modulator. 1. A magnetic recording and reproducing apparatus comprising: video signal detection means for outputting a detection signal for controlling. 2. The magnetic recording and reproducing apparatus according to claim 1, wherein the video signal generating means is a signal generating means for generating a video signal for channel adjustment of a television receiver.