JPH04365284A - Video reproducing device - Google Patents

Abstract

PURPOSE:To prevent sounds from being muted by a television receiver in the state of reproducing no image. CONSTITUTION:When a video head does not execute reproduction and a reproducing video circuit 17 does not output the video signal, a pseudo vertical synchronizing signal (i), similar to a vertical synchronizing signal at a video signal (d) is prepared by a pseudo vertical synchronizing signal generation circuit 51, led out to a video signal output terminal 18 and led out to an RF module 15. Since a vertical synchronizing signal detection circuit 33 detects the synchronizing signal from sounds from a tuner 32 and from pseudo vertical synchronizing signals f2-i2, a mute circuit does not output a mute signal (h). Thus, an audio video circuit 34 selects either an audio signal f2 from the tuner 32 or an audio signal (b) from a voice output terminal 16 and makes a loudspeaker outputs it as a voice.

Description

[Detailed description of the invention]

[Object of the invention]

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video reproducing apparatus that reproduces video and audio signals recorded on a recording medium and superimposes an audio signal from a microphone on the reproduced audio signal.

0003

2. Description of the Related Art Conventionally, a video playback device for playing back a videotape includes an amplifier that amplifies the audio signal of a microphone, and a circuit that mixes the audio signal from the amplifier with the playback sound from the videotape. , sends the sound from the microphone and the videotape playback sound to the television receiver,
Some TVs have a function (so-called karaoke function) in which the reproduced video, the reproduced sound, and the sound from the microphone can be viewed simultaneously on a television receiver.

On the other hand, some television receivers detect the presence or absence of a video signal among video and audio signals input from the outside based on the presence or absence of a synchronization signal, and mute the video if there is no synchronization signal. Furthermore, there are some that mute not only the video but also the audio.

FIG. 2 is a block diagram showing such a video playback device and a television receiver connected thereto.

In FIG. 2, a video reproducing apparatus 1 has a microphone 2 connected to its input side, and a television receiver 3 connected to its output side.

First, the video playback device 1 will be explained. The audio signal a from the microphone 2 is supplied to the microphone amplifier 12 via the microphone connection terminal 11. The microphone amplifier 12 amplifies the audio signal a and supplies it to the first input terminal of the adder 13. On the other hand, the audio circuit 14 constitutes an audio head (not shown) and audio reproduction means, de-emphasizes the audio signal reproduced by the audio head, and supplies the de-emphasis signal to the second input terminal of the adder 13. The adder 14 functions as a mixer, and mixes the audio signal b from the microphone amplifier 12 with the audio circuit 14.
The audio signal c is mixed with the audio signal c from the output terminal and outputted from the output terminal to the RF module 15 and the audio output terminal 16 as an audio signal b+c. The video circuit 17 constitutes a video head (not shown) and video reproduction means, and demodulates the FM video signal reproduced by the video head, converts the reproduced color signal to its original frequency, and converts the reproduced color signal to the video signal d. The video signal is output to the video signal output terminal 18 as well as to the RF module 15.

[0008] The RF module 15 includes the audio circuit 1
The audio signal b+c from 4 and the video signal d from the video circuit 17 are converted into an RF signal e of a predetermined channel.
It leads to the signal output terminal 19.

Next, the television receiver 3 will be explained.

The RF signal e from the RF signal output terminal 19 is supplied to the tuner 32 via the RF signal input terminal 31. The tuner 32 performs channel selection, intermediate frequency amplification, and detection on the input RF signal e, converts it into a composite video signal f, outputs it to the first input terminal of the vertical synchronization signal detection circuit 33, and outputs the audio signal. The signal is led out to the first input terminal of the video circuit 34. On the other hand, the audio signal b+c from the audio output terminal 16 is supplied to the second input terminal of the audio/video circuit 34 via the audio signal input terminal 35. Video output terminal 18
The video signal d from is supplied to the second input terminal of the vertical synchronization signal detection circuit 33 via the video input terminal 36, and is also supplied to the third input terminal of the audio/video circuit 34. The vertical synchronization signal detection circuit 33 selects one of the composite video signal f from the tuner 32 and the video signal d from the video output terminal 18 by operating a switch (not shown), detects a synchronization signal, and detects the detection result. A control signal g is supplied to the mute circuit 37.

The mute circuit 37 outputs a mute signal h when the vertical synchronization signal detection circuit 33 detects a synchronization signal.

The audio/video circuit 34 selects the first composite video signal f from the tuner 32 and selects the video signal d from the video output terminal 18 and the audio signal b+c from the audio output terminal 16 by operating the switch. Select one of the second selections in combination with and display video and audio on the cathode ray tube and speaker, and when the mute signal h is input, display another screen such as full white on the cathode ray tube. At the same time, the signal supply to the speaker is cut off so that no sound is output.

When such a video playback device is used for karaoke, during normal playback of a karaoke program, the vertical synchronization signal detection circuit 33 detects the composite video signal f from the tuner 32 and the video output terminal 18. One of the video signals d is selected and a synchronization signal is detected. In this case, since the synchronization signal is detected, the mute circuit 37
Does not output mute signal h. As a result, the audio/video circuit 34 selects the first composite video signal f from the tuner 32 and the second selection based on the combination of the video signal d from the video output terminal 18 and the audio signal b+c from the audio output terminal 18.
Select one of these options to display video and audio on the cathode ray tube and speakers.

On the other hand, when the video head reads a no-signal part such as a joint between programs on a magnetic tape or a part where the magnetic material has peeled off when the tape is used for karaoke,
The vertical synchronization signal detection circuit 33 selects one of the composite video signal f from the tuner 32 and the video signal d from the video output terminal 18 to detect the synchronization signal, but in this case,
Since the synchronization signal is no longer detected, the mute circuit 37
outputs a mute signal h, displays another screen such as full white on the cathode ray tube, and cuts off the signal supply to the speaker so that no sound is output.

Now, with reference to FIG. 3, a case will be considered in which the video playback device 1 and the television receiver 3 are used as a loudspeaker.

FIG. 3 is an explanatory diagram showing an equivalent circuit when the video playback device 1 and the television receiver 3 are used as a loudspeaker without playing back a magnetic tape, and the wiring that causes no signal is removed. are doing.

In FIG. 3, since no signal is output from the audio circuit 14 and the video circuit 17, the audio signal a from the microphone 2 is amplified by the microphone amplifier 12 and is output as the audio signal b without being mixed with the audio signal. It directly passes through the adder 13 and is output to the audio/video circuit 34, and the RF module 15 converts only the audio signal b into the RF signal e1, which is then guided to the tuner 32, where it is converted into the audio signal f1, and then sent to the audio/video circuit. 34. The vertical synchronization signal detection circuit 33 is connected to the tuner 32
A synchronization signal is detected from the audio signal f1 from the mute circuit 3, but in this case, since no synchronization signal is detected, the mute circuit
7 outputs a mute signal h, displays another screen such as full white on the cathode ray tube, and cuts off the signal supply to the speaker so that no sound is output.

As described above, the video reproducing apparatus 1 shown in FIG. 2 cannot be used as a loudspeaker depending on the model of the television receiver.

[0019]

[Problems to be Solved by the Invention] In the conventional video playback device described above, the presence or absence of a video signal is detected using a synchronization signal, and if there is no video signal, the audio is muted. The sound from the microphone cannot be output to the television receiver without playback.

SUMMARY OF THE INVENTION An object of the present invention is to provide a video playback device that eliminates the above-mentioned problems and can prevent a television receiver from muting audio even when no video is being played back.

[Configuration of the invention]

[0022]

[Means for Solving the Problems] A video reproducing apparatus according to the present invention includes an audio reproducing means for reproducing a first audio signal stored on a recording medium, and a microphone amplifier for amplifying a second audio signal from a microphone. an adder that mixes the second audio signal from the microphone amplifier and the first audio signal from the audio reproduction means and supplies the mixture to the television receiver; and a video image stored on the recording medium. a video reproducing means for reproducing the signal; and a pseudo synchronizing signal generator for generating a pseudo synchronizing signal equivalent to a synchronizing signal in the video signal and supplying it to a television receiver when the video reproducing means does not reproduce the video signal. It is characterized by comprising a circuit.

[0023]

[Operation] According to such a configuration, when the video reproduction means does not reproduce the video signal, the pseudo synchronization signal generation circuit creates a pseudo video signal equivalent to the video signal and supplies it to the television receiver. Therefore, it is possible to prevent the television receiver from muting the audio even if the video is not being played back.

[0024]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a video reproducing apparatus according to the present invention, and the same components as in the conventional example shown in FIG. 2 are given the same reference numerals.

In FIG. 1, a video playback device 5 has a microphone 2 connected to its input side and a television receiver 3 connected to its output side. Among the components of the video playback device 5, a microphone connection terminal 11, a microphone amplifier 12, an adder 13, an audio circuit 14, an RF module 15,
The audio output terminal 16, video circuit 17, video signal output terminal 18, and RF signal output terminal 19 have the same configuration as the conventional one.

The difference in this embodiment is that the video playback device 5
A pseudo vertical synchronization signal generation circuit 51 is provided to generate a pseudo vertical synchronization signal i.

More specifically, when the video head does not perform playback and the playback video circuit 17 does not output a video signal, the pseudo vertical synchronization signal generation circuit 51 generates a pseudo vertical synchronization signal equivalent to the vertical synchronization signal in the video signal d. Creating a vertical synchronization signal i and deriving it to the video signal output terminal 18,
The signal is derived to the RF module 15.

The operation of such an embodiment will be explained below.

When the video playback device 1 and the television receiver 3 are used as a loudspeaker, the pseudo vertical synchronization signal generation circuit 51 creates a pseudo vertical synchronization signal i and outputs it to the video signal output terminal 18. , to the RF module 15. On the other hand, the audio circuit 14 and the video circuit 1
Since no signal is output from microphone 7, the audio signal a from microphone 2 is amplified by microphone amplifier 12,
It passes directly through the adder 13 as the audio signal b without being mixed with other audio signals, is output to the audio/video circuit 34, and is also outputted by the RF module 15 to the pseudo vertical synchronization signal i from the pseudo vertical synchronization signal generation circuit 51. It is converted into an RF signal e2 of a predetermined channel and sent to the tuner 3.
Guided by 2. Then, the RF signal e2 is transmitted to the tuner 32.
, the signal is converted into an audio and pseudo vertical synchronizing signal f2+i2, and is delivered to the first input terminal of the audio/video circuit 34. Further, the vertical synchronization signal detection circuit 33 is connected to the tuner 32.
Since the mute circuit does not output the mute signal h, the mute circuit detects the synchronization signal by selecting one of the audio and pseudo vertical synchronization signal f2+i2 from the video signal output terminal 18 and the pseudo vertical synchronization signal i from the video signal output terminal 18. As a result, the audio/video circuit 34 selects one of the audio signal f2 from the tuner 32 and the audio signal b from the audio output terminal 16 and outputs it as audio to the speaker, and also outputs the pseudo vertical synchronization signal from the tuner 32. Screen with only signal i2 and video output terminal 1
One of the screens of the pseudo vertical synchronization signal i from 6 is selected and displayed on the cathode ray tube.

Video playback device 1 and television receiver 3
When used for karaoke, the pseudo vertical synchronization signal generation circuit 51 does not output the pseudo vertical synchronization signal i, and therefore operates in the same way as the conventional example shown in FIG.

According to this embodiment, even if the video playback device 1 does not play back video, the television receiver 3
Since it is possible to prevent the microphone from muting the audio and output the sound from the microphone to the television receiver without playing back the video, the video playback device 5 and the television receiver 3 can be amplified. Can be used on machines.

Although the video reproducing apparatus of the embodiment shown in FIG. 1 is provided with a pseudo vertical synchronizing signal generating circuit 51 as a synchronizing signal generating circuit, it is compatible with a television receiver that detects a horizontal synchronizing signal and performs muting. A pseudo-horizontal synchronization signal generation circuit that generates a pseudo-horizontal synchronization signal may be provided, or a pseudo-horizontal synchronization signal generation circuit that generates both horizontal and vertical synchronization signals may be provided. Further, although the video reproducing device 5 in the embodiment shown in FIG. 1 is a video reproducing device using a magnetic tape as a recording medium, it may be an optical video reproducing device.

[0034]

[Effects of the Invention] According to the present invention, it is possible to prevent the television receiver from muting the audio even if the video playback device does not play back the video, and it is possible to prevent the television receiver from muting the audio without playing back the video. Since the sound can be output to the television receiver, the video playback device and the television receiver can be used as a loudspeaker.

[0035]

[Brief explanation of drawings]

[0036]

FIG. 1 is a block diagram showing an embodiment of a video playback device according to the present invention.

[0037]

FIG. 2 is a block diagram showing a conventional video playback device.

[0038]

FIG. 3 is an explanatory diagram showing an equivalent circuit when a conventional video playback device is used as a loudspeaker.

[0039]

[Explanation of symbols]

2. Microphone 3 Television receiver 5 Video playback device 12 Mic amplifier 13 Adder 14 Audio circuit 15 RF module

Claims (1)

[Claims] Claim 1: Audio reproducing means for reproducing a first audio signal stored in a recording medium; and a second audio signal from a microphone.
a microphone amplifier that amplifies the audio signal; an adder that mixes the second audio signal from the microphone amplifier and the first audio signal from the audio reproduction means and supplies the mixture to a television receiver; video reproducing means for reproducing the video signal stored in the recording medium; and when the video reproducing means does not reproduce the video signal, creating a pseudo synchronization signal equivalent to the synchronization signal in the video signal for television reception. 1. A video playback device comprising: a pseudo synchronization signal generation circuit for supplying a pseudo synchronization signal to a video playback device.