JP3077230B2 - Signal output device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal output device suitable for use in, for example, a television receiver.

[0002]

2. Description of the Related Art Recently, an optical space system using infrared rays has been spreading. In a television receiver, a video tape recorder, or the like, a transmission method using infrared rays is used to transmit a predetermined command from a commander.
The transmission method using infrared rays is used not only for transmitting commands but also for transmitting video signals and audio signals. In this way, for example, the video signal and the audio signal are converted into infrared rays from a video tape recorder integrated with a camera and transmitted to the television receiver, and the television receiver detects this and displays the video signal on the screen. And an audio signal can be output from the speaker.

[0003]

By the way, a television receiver has a built-in VHF tuner or UHF tuner, and selects and outputs one of its output or one of signals supplied from a VTR. Is available. In conventional devices, this selection is made by the user manually operating a switch. As a result, operability was poor and inconvenient.

[0004] The present invention has been made in view of such a situation, and is intended to automatically select a desired signal.

[0005]

A signal output device according to the present invention comprises: an input means for inputting a broadcast signal;
Receiving means for receiving a signal transmitted by the input means, and input means
Broadcast signal input by the
Selecting means for selecting the received signal;
Determine whether the received signal is greater than the first reference signal;
Select according to the judgment means to refuse and the judgment result of the judgment means
Control means for controlling the means, and selecting means by the control means
Selects the signal received by the receiving means,
Signal so as to be a signal of the same level as the second reference signal.
And amplifying means for amplifying the signal.

[0006]

In the signal output device of the present invention , the received signal is
Signal is greater than the first reference signal.
Broadcast signal or received signal
Signal is selected and the received signal is selected
If the signal has a level equal to the second reference signal,
The signal is amplified so that it becomes

[0007]

FIG. 2 is a diagram showing a configuration example of a system to which the signal receiving apparatus of the present invention is applied. Camera integrated VTR1
Has a transmitter 2 built therein. In addition, the television receiver 3 is provided with a receiver 4 (signal receiving device). In the VTR 1, a video signal being captured and an audio signal being collected, or a video signal and an audio signal reproduced from an attached cassette tape (not shown) are converted into infrared rays by the transmitter 2, and are transmitted to the television. It is output to the receiver 4 of the John receiver 3.
The receiver 4 receives the infrared light output from the transmitter 2, demodulates the infrared light, displays an image corresponding to the video signal on the screen 5, and outputs sound corresponding to the audio signal from the speakers 6 and 7. The television receiver 3 also has a built-in VHF tuner and a UHF tuner inside.
The video signal and the audio signal received by the tuner or the UHF tuner can be output from the screen 5 and the speakers 6 and 7.

FIG. 1 is a block diagram showing a more detailed configuration of the television receiver 3 shown in FIG. The receiver 4 includes a photodiode 11, a video signal demodulation circuit 12 that demodulates and outputs a video signal from the output of the photodiode 11, and an audio signal demodulation circuit 13 that demodulates and outputs an audio signal from the output of the photodiode 11. An output terminal 14 is provided as an output terminal for outputting a demodulated video signal, and an output terminal 16 is provided as an output terminal for outputting an audio signal. Further, it has output terminals 15 and 17 as output terminals for outputting a detection signal corresponding to a level detection result described later. That is,
The receiver 4 is unitized in a range indicated by a broken line in the drawing, and can be used in any television receiver by mounting this unit on the television receiver.

The video signal demodulation circuit 12 includes a band pass filter (BPF) 21 for separating an FM video signal component from an output of the photodiode 11 (receiving means), an amplifier 22 for amplifying an output of the band pass filter 21, and an output of the amplifier 22. An AGC circuit 23 for controlling a level, an FM demodulator 24 for demodulating an FM video signal output from the AGC circuit 23,
Amplifies the video signal supplied from the FM demodulator 24 and compares the level of the FM video signal output from the amplifier 25 and the amplifier 22 to the output terminal 14 with the reference value output from the reference value generation circuit 26, The level detection circuit 27 outputs a control signal to the AGC circuit 23 in accordance with the comparison result, the output of the amplifier 22 is compared with the reference value output from the reference value generation circuit 28, and a signal corresponding to the comparison result is output. Terminal 1
5 and a level detection circuit 29 (detection means) for outputting the signal to the control circuit 5.

Although not shown, the audio signal demodulation circuit 13 has the same configuration as the video signal demodulation circuit 12. Then, the demodulated audio signal is output to the output terminal 16.
In addition, a detection signal corresponding to the detection level of the FM audio signal is supplied to the output terminal 17.

The video signal demodulated by the video signal demodulation circuit 12 is supplied from an output terminal 14 to a switch 31 (selection means).
Is supplied to the contact a. The video signal output from the VHF tuner 37 is supplied to the contact b of the switch 31, and the video signal output from the UHF tuner 38 is supplied to the contact c. The switch 31 selects any one of the video signals supplied to the contacts a to c and outputs the selected video signal to the output terminal 33. The output of the output terminal 33 is output and displayed on the screen 5.

The audio signal output from the audio signal demodulation circuit 13 is supplied via an output terminal 16 to a contact a of a switch 32 (selection means). The audio signal output from the VHF tuner 37 is supplied to a contact b of the switch 32, and a UH
The audio signal output from the F tuner 38 is supplied. The switch 32 selects one of the audio signals supplied to the contacts a to c and outputs the selected signal from an output terminal 34. The audio signal output from the output terminal 34 is supplied to the speaker 6 in FIG.

FIG. 1 shows only the left audio signal system as the audio signal channel and omits the right audio signal system. However, the right audio signal system is also the left audio signal system. It is a matter of course that the configuration is the same as that of. The audio signal of the right channel is supplied to the speaker 7.

The level detection circuit 2 of the video signal demodulation circuit 12
9 is output via an output terminal 15
For example, a control circuit 35 composed of a microcomputer or the like
(Control means). A detection signal output from a level detection circuit (not shown) of the audio signal demodulation circuit 13 is supplied to a control circuit 35 via an output terminal 17. The input unit 36 (switch 8 in FIG. 2)
Corresponding to the switches 31 and 3
2 is switched.

Next, the operation will be described. When the input unit 36 is operated to instruct reception of the VHF tuner 37, the control circuit 35 switches the switches 31 and 32 to the contact c side. As a result, the video signal and the audio signal output from the VHF tuner 37 are output to the output terminals 33 and 34 via the switches 31 and 32, respectively. When the input unit 36 is operated to instruct reception of the UHF tuner 38, the control circuit 35 switches the switches 31 and 32 to the contact b side. Thus, the video signal and the audio signal output from the UHF tuner 38 are output from the output terminals 33 and 34.

On the other hand, when the input section 36 is operated to instruct the output of the signal received by the receiver 4, the control circuit 35 switches the switches 31 and 32 to the contact a side. As a result, the video signal and the audio signal output from the output terminals 14 and 16 of the receiver 4
Are output to the output terminals 33 and 34 respectively.

At this time, the photodiode 11 receives the infrared light output from the transmitter 2 and converts it into an electric signal. The band pass filter 21 of the video signal demodulation circuit 12 separates an FM video signal component from a signal output from the photodiode 11. The FM video signal is amplified by the amplifier 22 and then input to the AGC circuit 23. The level detection circuit 27 detects the level of the FM video signal output from the amplifier 22 and compares the level with the reference level output from the reference value generation circuit 26. Then, a control signal corresponding to the comparison result is sent to the AGC circuit 2
Output to 3. As a result, the AGC circuit 23 adjusts the level of the FM video signal supplied from the amplifier 22 to a level corresponding to the control signal input from the level detection circuit 27. The FM video signal whose level has been adjusted in this way is input to the FM demodulator 24 and FM-demodulated.
The video signal output from the FM demodulator 24 is supplied to an amplifier 25
Is input to The video signal amplified by the amplifier 25 is supplied to the output terminal 3 via the output terminal 14 and the contact a of the switch 31.
3 is output.

As described above, the level of the FM video signal input to the FM demodulator 24 is controlled by the AGC circuit 23 so as to be equal to the reference value set in the reference value generation circuit 26. A video signal of a predetermined level can always be output regardless of the distance to the receiver 4.

In the above, the case where the input section 36 is operated to manually switch the switch 31 via the control circuit 35 has been described. In the present invention, the switches 31 and 32 are automatically switched in the following cases. Can be

That is, the output of the amplifier 22 is monitored by the level detection circuit 29, and is compared with the reference level output from the reference value generation circuit 28. The level detection circuit 29 detects the level of the amplifier 22 from the reference level output from the reference value generation circuit 28.
When the level of the signal output from the controller becomes high, the detection signal is supplied to the control circuit 35 via the output terminal 15.
When receiving the detection signal from the level detection circuit 29, the control circuit 35 automatically switches the switches 31 and 32 to the contact a regardless of the operation of the input unit 36. Thus, when infrared light having a predetermined level or more is input from the transmitter 2 to the photodiode 11,
Is automatically selected and output. That is, the fact that the infrared light is output from the transmitter 2 to the receiver 4 means that the user intends to output and display the output of the VTR 1 on the television receiver 3. Therefore, when the receiver 4 detects infrared rays of a predetermined level or more, the signal detected by the receiver 4 is automatically output and displayed on the screen 5 and the speakers 6 and 7. This eliminates the need to manually switch the switches 31 and 32.

In the above, the VTR is
Although the case where the signal output from 1 is received has been described as an example, it goes without saying that the present invention can be applied to the case where not only a video signal and an audio signal but also other signals are received.

[0022]

As described above, according to the signal output device of the present invention, it is determined whether the received signal is larger than the first reference signal.
And a broadcast signal or
Select one of the received signals, and
If a signal is selected, its signal is equal to the second reference signal
I amplified the signal so that it had a new level
This eliminates the need for manual switching, and improves operability and convenience.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a more detailed configuration in the embodiment of FIG. 2;

FIG. 2 is a perspective view showing a configuration of an example of an optical space communication system to which the signal output device of the present invention is applied.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 camera-integrated VTR 2 transmitter 3 television receiver 4 receiver 11 photodiode (receiving means) 12 video signal demodulation circuit 13 audio signal demodulation circuit 14, 16 output terminal 28 reference value generation circuit 29 level detection circuit (detection means) 30 switch (Selection means) 35 Control circuit (Control means)

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 5/44

Claims (1)

(57) [Claims] 1. An input means for inputting a broadcast signal, and a receiving means for receiving a signal wirelessly transmitted from another device.
Means, the broadcast signal input by the input means, or
Which of the signals received by the receiving means
Selecting means for selecting one of the two, and a signal received by the receiving means is a first reference signal.
A judging means for judging whether or not the value is greater than, and controlling the selecting means in accordance with the judgment result of the judging means
Control means, and the control means causes the selection means to communicate with the reception means.
If a more received signal is selected, the signal is
Amplify so that it becomes a signal of the same level as the reference signal of
A signal output device , comprising: amplifying means .