JPS585088A - Video reproducer - Google Patents

Abstract

PURPOSE:To avoid the care for electric shock, by separating a control signal supply part which controls a switch device for the switching connection with various signal supplies in a television receiver, in DC circuitry. CONSTITUTION:A signal from a tuner 12 is applied to a cathode ray tube 31 via a video intermediate frequency amplifier 14, a Y amplification chroma demodulation circuit 21, an RGB output circuit 23 and a video output circuit 30. Control terminals 48, 49, 50, 51 and 52 to switchingly control the 1st -4th switching devices 15, 24, 32 and 40 and a channel selection circuit 13 are provided so that this television receiver can be used for various display devices. The terminals 48-52 are controlled with a DC from a signal supply device 53 and a control signal is transmitted with a means with DC isolation and signal coupling, e.g., a photocoupler.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an fC video reproducing apparatus that allows a general television receiver to be used more easily as a display for a magnetic recording/reproducing apparatus, a video disk, or a personal computer.

Currently, television receivers not only play back original TV broadcasts, but also magnetic recording and reproducing devices (hereinafter simply referred to as VTRs).
It is also used as a display for video disc players. In addition, it is also used as a display for video games, audio cassette players, personal computers, etc. In order to connect these various devices to a television receiver and use the television receiver itself as a dice display, if the television receiver itself is used as a display for both video and audio, it is necessary to connect the television signal once with a signal supply device such as a VTR. This converted good signal is connected to the input terminal of the tuner, received using the empty channel of the tuner, frequency converted, converted to an intermediate frequency signal, and supplied to subsequent circuits for processing. .

Also, when using only the audio circuit system, input the audio signal from IFM reception, audio cassette player, record player, etc. to the audio output stage, shut off the power to other circuits unrelated to the audio output circuit system, and then use the TV receiver. The audio output circuit and speaker of the machine are used as the amplification stage and speaker of the signal supply device. Furthermore, it is also conceivable to utilize cathode ray tubes primarily for display purposes as display devices for teletext broadcasting and captain systems, which are currently being tested.

That is, in this case, it is sufficient to use the line image signal processing stage and subsequent stages, but by inputting the signal from the signal supply device to the color output circuit in the bone, it can be used as a display. In this way, television receivers can be used as displays for various devices, but at present there is no uniformity between the receiver and the signal supply device, and specifications are determined individually. The reality is that they are manufactured and sold individually.

For this reason, general television receivers employ hot chassis in view of cost and other factors. In the case of this hot chassis, the power supply ground and the chassis ground are common, so if a person touches the live part of the ground, they may receive an electric shock.

For this reason, the knobs that are accessible to general viewers from the outside are covered with an insulating wall with a wide or long space to prevent people from directly touching the live parts, with an insulating sheet interposed between them. Measures have been taken to prevent direct contact between the human body and the chassis. However, signal supply devices other than television receivers employ a cold chassis method in which the power supply and chassis ground are cut off in a DC manner. Therefore, even if the signal supply device is a cold chassis, when connected to a television receiver, the signal supply device may be exposed to hot chassis stains, for example, via the control signal line. In order to avoid this problem, this problem can be solved by adopting an AC coupling method and transmitting the control signal using AC, but this has the drawbacks of complicating the circuit and generating spurious signals.

The present invention has been made in consideration of these points, and is a device that separates the control signal supply part for controlling a switching device that performs switching connections with various signal supply devices in a television receiver and performs signal coupling. To provide a video reproducing device which does not have to worry about electric shock or the like even if the receiver side is a hot chassis by combining the two.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a circuit configuration diagram showing a video reproducing apparatus of the present invention. Voltage is supplied from the shim C power supply terminal 9 to a power supply circuit 10, and this circuit 10 obtains a DC voltage and supplies it to each circuit described below. A high frequency television signal from the high frequency signal input terminal 11 is supplied to a tuner 12. A channel selection circuit 13 is connected to this tuner 2, and a predetermined channel is selected by the 9-channel selection circuit 13, and the video intermediate frequency signal that has been selected and frequency-converted is transmitted to the Eirin intermediate frequency amplification circuit 14 (hereinafter referred to as 111 circuit)) and the first switching device 15
is supplied to the first terminal 16 of. This first switching device 1lt
The second terminal 1 of the first switching device 15 is connected to an external input input terminal 18, and the switching terminal 19 of the first switching device 15 is connected to an input amplifier and color demodulation circuit 21 constituting the first part of the video signal processing stage.

For convenience, it is assumed that the Shimano Eirin detection circuit (not shown) is included in the amplifier circuit. Therefore, if the switching terminal 19 and the first terminal 16 are now connected, the P-circuit 14
The output is supplied to the video amplification and color demodulation circuit 21. The video and color signals demodulated by this circuit 21 have their amplitude, phase, etc. controlled by the road signal in the ixm times, and are sent to the %jGB output circuit 23.
supplied to The output of this output circuit 23 is supplied to the Ml terminal 25 of the second switching device*24, and
Adjustment - External RGB input terminal AYA28 via wI2'F
It is connected to the. The switching terminal 29 is connected to one of the terminals 2526, but if it is now connected to the first terminal 25, the output from the RGB output circuit 23 is connected to the switching device 2.
4 to the video output circuit 3o. The video output circuit 3o amplifies the video signal and supplies it to the cathode ray tube 31. On the other hand, a synchronizing signal is separated from the video amplification and color demodulation circuit 21 and supplied to the first terminal 33 of the third switching device 32 . A second terminal 34 of this device 32 is connected to an external synchronizing signal input layer 35, and a switching terminal 36 is connected to the synchronizing circuit 3. Therefore, if the first terminal 33 and the switching terminal 36 are now connected, a synchronizing signal is supplied to the synchronizing circuit 3'/, and the necessary synchronizing process is performed in this synchronizing circuit 3'/ It is used to drive the deflection system and generate various gate signals.

On the other hand, regarding the audio system, the audio signal components are separated in the P circuit 14 and the audio intermediate frequency intensifier circuit 38 (hereinafter referred to as %81F
The signal is amplified by the audio multiplex demodulation circuit 39 and supplied to the first terminal 41 of the fourth switching device 4o. A second terminal 42 of this switching device 4o is connected to an external audio flight number input terminal 43. And the switching terminal 44 is 1111
It is connected to an audio output circuit 46 via a control device 45, and is further connected to a speaker 4. When the switching terminal 44 of this fourth switching device 4° is connected to the first terminal number 1, the audio signal for the stereophonic reception is demodulated and a reproduced output is obtained from the speaker number N.

・With this configuration, the television receiver can be used as a display device with six virtues.
, and the first to fourth switching devices 152432i 40
And if necessary, control terminals 48495051 and 52 are provided for switching and controlling the channel selection circuit 13, respectively. The switching terminals 48 to 52 are controlled by direct current from the signal supply device [53] described above, and the control o4 signal is transmitted by means of direct current separation and signal coupling, which will be described later.

The overall overview of the image 4#4+Nyu apparatus configured in this manner is shown in FIG. 2. First, as the decoding supply device 53 for supplying the video *m number, in addition to the television receiving circuit wI 54, the VTR 55, the video disc player 56, and the 8Ii? The terminals 59 to 62 of the changeover switch 58 are led out from the respective devices 64 to 5 of the television adapter 5), and by switching these with the changeover terminal 63 of the changeover switch 58, a desired signal source can be selected. can. Then, an off terminal 64 is set to this terminal 620, and when the video signal supply is not required, the switching terminal 6
3 is connected to this off terminal 64. In addition, a magnifying camera 65 is connected to the VTR55 and the VTR is connected through the signal conversion circuit 66.
It may also be configured in such a way that it is connected to R55. On the other hand, as an audio signal supply device, M/1'M! ! 16'7
, an audio cassette recorder 68 and an audio player 69, and a switch 70 is provided for selecting each of these devices 6-69.
-69 outputs are connected to terminals 11-3, respectively.

Furthermore, the television receiver circuits 54 to 8H'? An audio signal from the television adapter 57 is supplied to terminal No. 1, and a switching terminal 16 switches between these terminals 11 to M.
is selectively connected to one of the terminals. It should be noted that each of the devices 67 to 69 can be configured so that the signal from the microphone 16 is supplied via the amplification circuit F1.
Furthermore, in order to record the audio signal from the television receiver circuit 54 directly onto the cassette recorder 68, the terminal '14 and the cassette recorder 68 may be connected via the selection switch 1B. On the other hand, as an RGB signal supply device, a teletext multiplex broadcasting adapter 9 and a personal adapter 81 are connected to a telephone line connection terminal 82. The outputs of these devices are also connected to terminals 84 to 86 of a changeover switch 83, respectively, and by selecting the changeover terminal 8f of the switch 83, one of the outputs can be selected for damming. The signals are supplied to various signal supply devices 55565 and 6843 other than the television receiver circuit. These devices and external signal input terminal 1828
The connection relationship with the circuits after 3a 43 is shown in FIG. For selection and mode designation of each of these devices, switching from device to device [11524324o 6 devices for K wLl
A control signal is supplied from 111, and this control signal is supplied to control terminals 48 to 51 to switch terminal 1 of switching device 1524324o so as to select the circuit corresponding to the use of each device.
Switch and connect 9293644. Further, terminals 88 to 91 are provided with control signals between the respective devices and circuits.

It shows. The control of this switching device d (1524324o) is performed, for example, as shown in Figure !@3.

That is, in FIG. 3, a voltage is applied from the power supply +vB to one end of the changeover switch 101 in the signal supply device 53 that interlocks with the changeover switch (not shown) of the signal supply device @53, and the other end is applied to the changeover switch 101 of the signal supply device @53. The terminal 103 is connected to the television receiver main body 10 via a connection cord 104.
5 terminal 106. A lamp of a photocoupler 10 or a light emitting diode 108 is connected to this terminal 106, and the other end of the light emitting diode 108 is connected to a terminal 109 of the television receiver body 105. This terminal 109 is connected to a terminal 111 of a signal supply device 1153 via a connection cord 110, and this terminal 111 is grounded. On the other hand, the light receiving element \112 of the photocoupler 10, such as CD8, photocoupler, transistor, etc.
A bias voltage is supplied from a terminal 113 to one end thereof, and the other end is grounded via a resistor 114. A plurality of buffer amplifiers 115 are connected to one end of this resistor 114, respectively.
115/... are connected in parallel. Relay 1:16116' is connected to the output side of this % amplifier 115.
One end of the parallel circuit of the coil ll'F and the diode 11B is connected, and the other end of the parallel circuit is connected to the Hiro terminal 113.
It is connected to the. This relay has 116 relay terminals 1191s! O @ It is connected to the power supply circuit (not shown) of the television receiver aircraft main body 105. Also, the terminal wire of the relay terminal 121122123 of the relay 116I, for example, considering a VTR as the signal supply device 53, the terminal 121 is not shown in Figure 1! The relay 116' corresponds to the first terminal 16 of the switching device 15 of s1, the relay terminal 123 corresponds to the second terminal 1, and the relay terminal 122 corresponds to the switching terminal 19. 15, and the control terminal, that is, the control signal is transmitted by the photocoupler 10''/ to control the relay 116'.This relay \116 has a number corresponding to one point to be controlled. The terminals of the relays are connected to circuits corresponding to the respective terminals of the switching device according to the respective signal transmissions.Such a configuration is provided corresponding to each signal supply device. However, for convenience, only a part of the configuration is illustrated, and details of each configuration are omitted.

With this configuration, for example, when you press the bookstore button on the VTR55, the switch 'lo' is activated in conjunction with this operation.
g is turned on. According to this, connection cord 10 from the power supply
A direct current flows through the path 4→light emitting diode to 108→connection cord 110→ground, and the light emitting diode XOS lights up. By lighting the light emitting diode 10B, the resistance value of the light receiving element 112 decreases, and a large voltage is generated across the resistor 114.

This voltage change is amplified by the amplifier 115 and the relay 11
6 to short-circuit the terminals 11912i0.

As a result, the power to the image receptor main body 105 is turned on and the image receptor main body 105 is brought into operation.

The voltage across resistor 114 is similarly amplified in amplifier 115' to drive relay 116'.
In the non-operating state, terminals 121122 were connected, but terminals 122123 are now connected.

The operation of this relay is the same for each control terminal 49505152.
Similarly, when playing V4R65, the receiver main body 105 is required! Sonodokoro switching device $! 4324o and switches the channel selection circuit 13 to a predetermined state as necessary. Therefore, the signal supply device 53 and the receiver body 105
The signal supply device d53 and the receiver main body 105 can be separated from each other in terms of direct current, even though they are controlled by direct current. For this reason, even if the receiver 91 main body 105 is a hot chassis, it is separated from the No. 16 supply device [55 in terms of DC current, so even if a human body comes into contact with the chassis bottom on the signal supply device 1i53 side, the hot There is no possibility of receiving electric shock from the chassis. In the above description, the signal supply device and the receiver main body are coupled by a photocoupler, and although the circuit is complicated due to the provision of a wave circuit, it can be operated in the same manner as in the above embodiment.

Further, the RGa output circuit and Eirin output circuit portions shown in FIG. 2 may be configured as shown in FIG. 4. That is, R
The output of the GB output circuit 23 is inputted to the signal supply devices 19 to 81[, the outputs of these devices 9 to 81 are inputted to the video output circuit 3° via the control device 2), and the synchronization signal is inputted to the RGB output circuit 23. The same parts as those in the above embodiment are given the same reference numerals, and detailed explanation thereof will be omitted. With such a configuration, it is possible to configure and operate in the same manner, but if a signal supply device is not present, it is necessary to short-circuit between the KGB output circuit 23 and the control device 127 or the signal output circuit 3o. In each of the above embodiments, explanations have been made on the assumption that there are multiple signal supply devices, but the number of signal supply devices may be one or more, and if there is no signal supply device at all, it can be used as a frost-free television receiver. For example, when a VTR signal is added to a tuner using an empty channel, the channel selection circuit can be controlled by automatically setting an empty channel. On the receiver main body side, relay circuits are assembled according to each signal supply device, but common parts can also be made common. Needless to say, various other design changes and combinations are possible.

Having said the above, I would like to say to my friends that according to the present invention, the television receiver may be configured with a hot chassis, combined with a signal supply device, and the receiver body may be controlled in accordance with the control signal from the signal product supply device. When operating the signal supply device itH, even if the human body touches the chassis, it is safe and will not receive an electric shock, and since control from the signal supply device can be performed using direct current, the circuit can be configured easily. It has a number of advantages, such as less risk of malfunction than a scale, and the ability to eliminate problems caused by spurious signals.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing the main body of a television receiver constituting a Bō4II playback device according to the present invention, FIG. 2 is a circuit diagram schematically showing a video playback device according to the present invention, and FIG. Similarly, FIG. 4 is a circuit diagram showing a modification of the connection between the television receiver body and the signal supply device, and FIG. 4 is a circuit configuration diagram showing a modification of the video reproducing device shown in FIG. 2. 10--Power supply circuit 12--Tuner 14--211 circuit 15--First switching device first--Video signal processing stage 24... -Second switching device 31...Cathode ray tube 32-...Third switching device 38...817 Circuit 40--Fourth switching device 49,50,51 ,52-...Yuden-Akita63-
...-Signal supply device 10'F--Photocoupler

Claims (1)

[Claims] 1) A tuner that converts the received high-frequency television signal into an intermediate frequency signal, an amplifier circuit that amplifies this intermediate frequency signal, and a detector that demodulates a video signal from the output signal from this amplifier circuit. a video signal processing stage having a wave stage, a cathode ray tube for reproducing the output of this processing stage on a screen, an audio signal demodulating means for demodulating an audio signal from the video signal or intermediate frequency signal, and an audio signal for amplifying the demodulated output. a television receiver body equipped with an output circuit; a switching device interposed in at least ten thousand video signal systems or audio signal systems of the main body;
a signal supply device that supplies a reproduction signal from outside the receiver main body to an external input terminal of the switching device;
means for supplying a DC control signal for controlling the switching device from the signal supply device so as to select a signal from the television;・This is a video playback device that has 0% mold since the receiver itself is constructed of a hot chassis. g) The video reproducing apparatus according to claim 881, wherein the coupling means is constituted by a seven-point coupler.