JPS6041377A - Coupling device of external signal with television receiver - Google Patents

Abstract

PURPOSE:To improve operability by controlling a channel selecting voltage generating circuit with n-number of outputs from an (n+1)-notation counter and controlling a changeover switch with another output. CONSTITUTION:In case of reception of a TV signal, one of changeover switches 11-22 is selected to obtain an output only in the prescribed output terminal of a counter 43 related to the selected changeover switch. Consequently, a channel selecting voltage is generated only from a variable resistance, which is connected to said prescribed output terminal, out of n-number of variable resistances 24-35 connected to the output side of the counter 43, and this channel selecting voltage is sent to an electronic tuning tuner 37. The existence of the (n+1)th input is stored in the counter 43 by the operation of a changeover switch 23 to output ''1'' alternatively, and a changeover switch 38 is switched by this output to reproduce the video output of a VTR1 onto a CRT9 as a picture. Pulses having a prescribed period are supplied to the counter 43 by the operation of a remote control device 44, and output ''1'' is supplied to succeeding channels successively.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an external signal to a television receiver that enables image reproduction of video signals other than the receiving channel of the television by a simple operation similar to a normal channel selection operation. relating to a coupling device.

Generally, when observing a video signal sent from a recording/playback device, such as a VTR (video tape recorder) or a video camera, on a general home television receiver, the video signal sent from the recording/playback device described above is generally used. modulates a high-frequency signal of a frequency corresponding to a specific channel in the frequency band that can be received by the television receiver using the video signal obtained by the television receiver, supplies it to the antenna terminal, and tunes the tuner to the above-mentioned specific channel (for example, an empty channel). I have to.

That is, as shown in FIG. 1, the output from the VTR 1 is modulated with a video signal to a high frequency in a non-broadcast frequency band in a modulator 2, and then input to a mixer 3. On the other hand, a plurality of video signals of predetermined frequencies corresponding to television reception channels are supplied from the antenna 4 to the mixer 3.

Then, the tuner 51C selects the high-frequency video signal of the VTR inputted to the mixer 3 and the other video signals from among the plurality of other television signals, and the VIP circuit 6, the video detection circuit 7, and the video amplifier 8 An image corresponding to the above video signal 1 is reproduced on the CRTQ.

However, according to such conventional connection methods, the frequency band obtained by modulating the above-mentioned modulation frequency band (for example, the frequency band corresponding to channels 2, 5, 7, and 9.11, which are empty channels in Tokyo). The high frequency video signal of the VTR is
Mutual interference occurs with other broadcast television video signals in the mixer (2), both during broadcast reception and VTR playback.
This causes a slight deterioration in image quality.

On the other hand, in order to prevent the deterioration of the image quality, as shown in FIG.
A method has been proposed in which the video amplifier 8 of the television is directly coupled to the video amplifier 8 through the video amplifier 8 of the television. Must. Also, when receiving regular television broadcasts, you must switch the tuner according to the desired channel pressure.
Therefore, it is impossible to avoid poor operability due to selective switching between these two beds.

The present invention enables selective image reproduction of television video signals from such broadcasting stations and other external video signals.
The present invention proposes a device for coupling external signals to a television receiver, which is performed without deterioration of the image and by a simple switching operation.

That is, the feature of the external signal coupling device for a television receiver according to the present invention is that it includes an electronic tuning cheese, and supplies a tuning voltage determined corresponding to each broadcast channel to the electronic tuning cheese. A channel selection voltage generation circuit, an (n+1)-adic counter whose state is sequentially changed by a signal from a remote control device, and a video detector that detects the output from the electronic tuner to obtain a television video signal. circuit, and a changeover switch that selectively switches between the television video signal from the video detection circuit and the external video signal supplied from outside the television receiver and supplies the same to the CRT. ) from the base counter (n+1
) out of the n outputs, and the other outputs control the changeover switch.

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4.

FIG. 3 is a circuit diagram showing one embodiment of the present invention, and the same numbers as in the previous two figures indicate the same components. 11 to 22 are changeover switches corresponding to each broadcast channel of the television receiver, and 23 is a changeover switch of the VTR 1 connected in parallel to the changeover switch.

Further, 24 to 35 are variable resistors that generate a predetermined channel selection voltage corresponding to each broadcast channel, 36 is an OR gate circuit, 37 is an electronic tuning cheese, and 3B is a switching switch provided in the television receiver. It is a switch device.

Therefore, the switches 11 to 23 are non-locking switches, and there are (n+1) in total, for example, 13 switches and n (
For example, 12 channels correspond to the reception channels of the television receiver, and the other one corresponds to the reproduction channel of the VTR 1, as described above. A remote control device 44 is connected to an (n+1)-ary counter 43 to which these switches 11 to 23 are connected, which sequentially generates pulses to select a channel.

Next, the front surface of the television receiver having such a switch is as shown in FIG. The changeover switches 11 to 22 corresponding to channels 1 to 12 and the switch 23 for selecting VTR signals are successively arranged in parallel. Note that 39 to 42 are adjustment knobs for each part of the circuit of the television monitor M, and the changeover switches 11 to 23 are non-mac switches. -My tongue is tongue-tied.

Therefore, in the above circuit configuration, when the television receiver receives a television signal from a broadcasting station, one of the changeover switches 11 to 22 is selected depending on the channel to be received. In particular, an output is available only at the predetermined output of the counter 43 associated with the selectively operated changeover switch. Therefore, among the n (for example, 12) variable resistors 24 to 35 connected to the output side of the counter 43, the channel selection voltage is generated only from the variable resistor connected to the predetermined output terminal. A predetermined broadcast channel is received by sending the local voltage to the electronic tuner 37 via the OR gate circuit 36.

The video signal of the broadcast channel from this electronic tuning team 37 is supplied to the video amplifier 8 via the fixed contact 38b and movable contact 38a of the changeover switch device 38, and
The image is played on RT.

In addition, by operating the remaining 1 changeover switch 23, (n+
1) The counter 43 memorizes that there was the input, does not perform channel selection, and alternatively outputs 1 as the memory output corresponding to the (n+1)th input. To change the output, the five-switch device 38 is switched to display the video output of the VTR 1 on the CRTq via the fixed contact 38C, the movable contact 38a, and the video amplifier 8.

Furthermore, when switching to the predetermined reception channel of the television again, the switch 38 is reset and the television reception state is established. Further, by operating the remote control device 44, pulses of a predetermined period are supplied to the counter 43, and one of the counter outputs is sequentially and selectively supplied to the next channel. By stopping, the reception state of one predetermined reception channel is maintained. According to this configuration, image reproduction based on an external input signal from a VTR or the like is performed by an operation equivalent to the reception channel selection operation on a television receiver, so that operability is improved. Furthermore, if the (n+1) alternative storage circuits are constructed using ICs, the cost can be reduced because simply adding one storage element hardly increases the cost.

[Brief explanation of the drawing]

1 and 2 are circuit diagrams showing a conventional external signal coupling device for a television receiver, FIG. 3 is a circuit diagram showing an embodiment of the coupling device according to the present invention, and FIG. 4 is a circuit diagram showing an embodiment of the coupling device according to the present invention. 1 is a front view of a television receiver using the coupling device of FIG. 1・・・・・・・・・・・・・・・・・・・・・・・・VT
External signal generator 7 for R...
......Video detection circuits 11 to 22...
・Switch 23 for selecting the television reception channel...Switches 24 to 35 for selecting the external signal reproduction channel...Switch for generating channel selection voltage Variable resistance 3γ・
・ ・・・ ・Electronic tuning team 38 ・・・・・
......... Changeover switch device 43...
・・・・・・・・・・・・(+1+1) base counter 4
4・・・・・・・・・・・・・Remote control/
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Claims (1)

[Claims] An electronic tuning tuner, a tuning voltage generation circuit that supplies a tuning voltage determined corresponding to each broadcast channel to this electronic tuning data, and its state is changed sequentially by a signal from a remote control device. a (n+1)-adic counter, a video detection circuit for detecting the output from the electronic tuning tuner to obtain a television video signal, and supplying the television video signal from the video detection circuit to the outside of the television receiver. By selectively switching between the external video signal and
The above (n+1)
Coupling of external signals to a television receiver in which n outputs out of (n+1) outputs from a numeric counter control the channel selection voltage generation circuit, and other outputs control the changeover switch. Device.