JPS5827583Y2 - television receiver - Google Patents

Description

[Detailed description of the invention] The invention switches between a general television broadcast signal and an external signal from a video tape recorder, television camera, etc.
This invention relates to a television receiver having a switching device for transmitting signals to a picture tube (CRT), and in particular includes a plurality of tuning switches and a band selection switch for switching the tuning band for each of these tuning switches. Regarding television receivers.

The operating section of a conventional television (hereinafter abbreviated as TV) receiver of this type has an appearance as shown in FIG. 1, for example.

In this FIG. 1, an operation button 10 for channel selection is shown.
1,102゜103,... are ON when pressed, for example.
This is a pushbutton switch that turns on, or a touch switch that turns on when touched by a human hand, etc., and the display section 1
11.112,113. ... displays a number or symbol indicating the selected channel by emitting light or changing color.

Here, each operation button 101, 102, 103. ...
Channel settings corresponding to channel settings are made using the channel setting preset knobs 121, 122, 123, . . . and band selection switches 131, 132, 133, . It is carried out by...

These band changeover switches 131, 132, 133.・・・
・VHF low channel band V from 1ch to 3ch
It is used to switch to one of the high channel bands of 4ch to 12ch of HF and the three bands of UHF band, and the desired channel within these switched bands is selected using the preset knobs □121, 122, 12.
3. It is configured so that settings can be made by operating...

In this case, the channel to be set is a channel of a broadcast station that can be received in the area where the TV receiver is used, and once set, there is almost no need to change it.

Therefore, during normal use, these preset knobs 1
21,122,123. ..., band selection switches 131, 132, 133 . ... is hidden with a lid etc.

On the other hand, the operation button 101 for selecting the channel
, 102, 103. ... etc. are used frequently, so T
It is placed exposed on the front panel of the V receiver.

In addition to the above preset knobs 5121, 122, 123
, . . . may be separately arranged on the side or back of the TV receiver.

By the way, a video tape recorder (hereinafter referred to as VTR)
For TV receivers that can be connected to VTR playback, the above T
It is necessary to switch between the V broadcast reception mode and the VTR playback mode using some kind of mode changeover switch.

For this reason, in the past, for example, a sliding mode changeover switch 15 was arranged at the position shown in FIG. By switching to the side, signals from the connected VTR were played back.

In this case, when the camera is switched to the VTR side, it is not possible to obtain a received image of the TV broadcast even if any of the operation buttons 101, 102, 103, . . . are operated.

Therefore, if you suddenly want to obtain a TV broadcast image during VTR playback, you must first switch the mode selector switch 25 to the TV side and then operate the operation button for the desired channel. It's a hassle.

Furthermore, for models that do not require VTR connection,
For models that require connection, the shape of the panel surface of the operating section is different, and one additional part of the mode changeover switch 25 is required, making the assembly work that much more troublesome and making it difficult to change models. .

The purpose of the present invention is to eliminate these conventional drawbacks, to easily switch to VTR playback mode with the same operation as channel selection, and to easily change from a model that does not require VTR connection. To provide a television receiver that can be connected to a VTR and does not require additional mechanical parts such as a mode changeover switch.

In other words, the TV (television) receiver according to the present invention is
In a TV receiver having a switch corresponding to a plurality of channel selection operation buttons and a band changeover switch connected to each of these switches, at least one of the plurality of band changeover switches is connected to a VTR.
A terminal for mode switching is provided as a switching terminal, and when the band switching switch is switched to the VTR mode switching terminal and the switch connected to this band switching switch is turned on, the VTR basic mode is switched on. It is characterized by a configuration that allows switching.

Therefore, with the exact same operation as channel selection, VT
It is possible to switch to the R playback mode, improving operability, and the appearance of the operation section is similar to models that do not require VTR connection, and the mode selection switch 2 described above
It is possible to change the model without the need for mechanical parts such as 5.

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

FIG. 2 is a circuit diagram showing a first embodiment of the present invention.

In FIG. 2, a TV broadcast signal is received by an antenna 1, tuned by a tuner 2 and a channel selection device 20, amplified by an intermediate frequency amplifier 3, and then detected by four video detectors.

Here, the antenna 1 and tuner 2 each have V
HF is shown as 1v=2v, and UHF is shown as 1u and 2u.

The detected output from the video detector 4 is sent to the video amplifier 6 via the gate circuit 51 of the TV/VTR mode switching circuit 5.

Further, the detected output is sent to an external output terminal a, and a VTR 80 input terminal is connected to this external output terminal a.

The output terminal of this VTR 8 is connected to the external input terminal of the TV receiver, and the VTR playback signal supplied to this external input terminal is passed through the gate circuit 52 of the TV/VTR mode switching circuit 5 to the video receiver. The signal is configured to be sent to an amplifier 6.

The amplified output of the TV or VTR signal from the video amplifier 6 is supplied to a picture tube (hereinafter referred to as CRT) 7.

Next, the tuner 22, the channel selection device 20, which is the main part of the present invention,
The and TV/VTR mode switching circuit 5 will be further explained.

The tuners 2 & 9 are so-called electronic tuners, and the tuning frequency, that is, the channel to be tuned changes in response to a control signal from the tuning device 20.

This uses, for example, a voltage-controlled varicap or the like as the actance element of the LC resonant circuit inside the tuner 2.
This is done by changing the resonant frequency by changing the voltage applied to this varicap.

The applied voltage signal in this case corresponds to the control signal from the channel selection device 20.

The channel selection device 20 shown in FIG. 2 is configured to correspond to the external appearance of the operation section as shown in FIG. 3, and includes operation buttons 101, 102, 103, . Switch 2 corresponding to...
01°202.203. ...2 display sections 111, 112
Neon lamps 211, 212, 213, . . . are arranged behind the panels of ゜113, . . . . variable resistors 221.2 for control voltage presetting corresponding to the preset knobs 121, 122, 123° . . . for channel setting.
22,223. ..., and band selection switch 13
1,132,133. Selector switch 2 corresponding to...
31,232,233. It is equipped with...

The above switch 20L 202, 203°... has the following:
Switching transistor 241, 242゜243,・
The respective connectors of the switching transistors 241, 242, 243, . . . are connected, and the bases of the switching transistors 241, 242, 243, .

In addition, the switches 201, 202, 203. The other terminals of the counters are commonly connected and connected to the input terminal of the ring counter 250 via the pulse generator 26.

The variable resistors 221, 222, 223. The output terminals of ... are diodes 271, 272, 27 for backflow prevention.
3°... and then commonly connected to the control voltage output terminal C of the channel selection device 200.

This control voltage output terminal C is connected to the control voltage input terminals of the tuners 2u and 2v, respectively.

Since the above configuration is similar to that of a conventional channel selection device, the operation will be briefly described.

That is, in the initial state, the transistors 241 and 24
2,243. When any one of them, for example, the transistor 243, is in the ON state, only the neon lamp 213 lights up to display the numbers or symbols on the display section 113, and the 10B power supply voltage is connected to the variable resistor. The voltage is divided only in the circuit 223 and appears at the output terminal.

Since the transistors 241, 242, etc. connected to the other variable resistors 221, 222, etc. are OFF, the respective output terminal voltages are approximately equal to the 10B power supply voltage.

Therefore, diodes 271, 272, 273 .・・・
Therefore, the voltage appearing at the control voltage output terminal C of the tail selection device becomes the output voltage of the variable resistor 223, which is the lowest voltage.

This variable resistor 223 is preset to a divided voltage according to the channel to be selected, and as will be described later, the band changeover switch 233 is also preset to the band that includes the channel to be selected. , tuner 2u, 2v
One of them, for example, the VHF tuner 2v, is operated, and the above-mentioned divided voltage is applied as a control voltage to the resonant circuit of the VHF tuner 2v, for example, to select the set channel, for example, 4ch.

At this time, switches 201, 202, 203. . This is expressed as “1”)
All other output terminals are at low potential (Low, hereinafter expressed as "0").

Next, if an operation button other than the operation button 103 of the selected channel, for example operation button 101, is operated, the corresponding switch 201 will be set to 0N- for the above operation time (for example, about 1 second). J”ru.

At this time, a signal "1" is applied to the input terminal of the pulse generator 26 via the switch 201 by a 10B power supply or the like,
The pulse generator 26 generates a pulse with a very short cycle (for example, 0.7 ms la degree) compared to the operation time, and the output "1" of the ring counter 25 changes in accordance with this pulse cycle.

That is, each transistor 241°242.243.・・・
While only one of the plurality of output terminals connected to the base of the terminal satisfies the condition that the output is "1", this output "1" transits to the other output terminals one after another.

Due to this transition, the switch 2 in the ON state
The transistor 2410 base connected to 01 is “l”
When transistor 241 turns on, switch 2
Since 01 is grounded through the transistor 241, the input terminal of the pulse generator 26 becomes rOJ.

Therefore, at this time, the operations of pulse generator 26 and ring counter 25 are stopped, and the base of transistor 2410 is fixed at "1".

In addition, the neon lamp 211 lights up, and the variable resistor 221
The 0 minute voltage is supplied to the tuner 2 via the diode 271 as a control voltage.

Next, the changeover switch 231, 232, 233°...
・Explain about.

These changeover switches 231°232.233. ... have three switching terminals each, and these three
These switching terminals are normally used as a UHF band switching terminal U, a VHF low channel band switching terminal vL, and a VHF high channel band switching terminal vH.

However, in the present invention, for at least one changeover switch, one of the three changeover terminals is connected to V
Used as a terminal for switching TR mode.

That is, in Section 2 and FIG. 3, as an example, a case is shown in which the central switching terminal of the n-th changeover switch 23n is used as a VTR mode switching terminal.

That is, operate the band changeover switch 13n in FIG. 3 to change the changeover switch 23n to the VTR mode changeover terminal, and then press operation button 1 when you desire VTR playback.
0n to turn switch 20n ON-j.

Then, the pulse generator 26 starts operating, the output of the ring counter 25 changes to "1", and the transistor 24n is turned on.
At this point, the operation of the pulse generator 26 and the ring counter 25 is stopped, and only the transistor 24n is fixed in the ON state.

At this time, the neon lamp 21n emits light, the characters "VTR" on the display section 11n are displayed, and the VTR mode switching terminal of the changeover switch 23n is connected to the transistor 24n.
grounded via.

Since this VTR mode switching terminal is connected to the base of the switching transistor 530, this switching transistor 53 is ONL, and output rlJ from the collector.
occurs.

This collector output "1" is sent to the TV/VTR mode switching circuit 5 and controls gate circuits 51 and 52.

At this time, the gate circuit 51 cuts off the TV signal, and the gate circuit 52 passes the VTR signal from the VTR 8, so this VTR signal is amplified by the video amplifier 6, and the CB
It is reproduced by r4.

When the collector output is "0", the gate circuit 51
Of course, only the TV signal can pass through.

Note that various configurations are possible for band switching between UHF and VHF; for example, changeover switches 231, 232
, 233. The switching transistors 9u have their respective U terminals connected in common and perform mutually complementary operations.

Connected to each pace of 9V.

That is, the switching transistor 9u operates the UHF tuner 2u, and the switching transistor 9v operates the VHF tuner 2v, and when one of them is ON, the other is OFF.

Therefore, when the channel switched to the U terminal is selected, since the U terminal is grounded, the switching transistor 9u is turned on and only the UHF tuner 2u can be operated.

The above was an example of a TV receiver that can select channels in all the VL and VHlH bands, but in areas where there are no vL band broadcasting stations, such as the Republic of South Africa, the required band is the vH band. and U band, all of the vL band switching terminals of the changeover switch can be used as VTR mode switching terminals.

That is, FIG. 5 shows the second embodiment of the present invention, which shows a TV receiver for areas where only two bands, the vH band and the U band, are required as described above.

In this Fig. 5, the number of selectable channels is 6, and 6
changeover switches 231, 232. ... 236 are commonly connected as VTR mode switching terminals, and are connected to the base of a switching circuit 530 and a human power stage switching transistor 540.

, this switching circuit 53 has a switching transistor 51' which becomes the gate of the TV/VTR mode switching circuit 5.
, 52' is turned on.

Two switching transistors 55 are used for OFF operation and perform complementary operation with each other.
．． It has 56.

That is, each changeover switch 231, 232 . ..., 2
When none of the central VTR mode switching terminals 36 is grounded, the base input of the transistor 54 is "1" and the collector output is "0".

Therefore, the transistor 55 is OFF and the collector output is rOJ, and the transistor 56 is ON and the collector output is "l".

At this time, in the TV/VTR mode switching circuit 5, the transistor 51 is turned on and the transistor 52' is turned off, so that only the TV signal is sent to the video amplifier 6 through the transistor 51.

Next, when you want to switch to the VTR mode, at least one of the changeover switches 231, 232°, . . . , 236
For example, the sixth switch 236 is switched to the VTR mode switching terminal, and the sixth switch 236 is switched to the VTR mode switching terminal.
If you turn on 06, the transistor 540 base power will turn on.
O'', so the collector output of the transistor 54 is r
lJ,) The emitter output of transistor 55 is "1", the collector output of transistor 56 is "0", TV/
VTR-E-)" transistor 51' of switching circuit 5 is O.
The FF transistor 52' is turned on.

Therefore, the TV signal is cut off and only the VTR signal is sent to the video amplifier 6 via the transistor 52'.

That is, transistors 51' and 52' correspond to gate circuits 51 and 52 in FIG. 2, respectively.

Band switching between UHF and VHF is the same as shown in FIGS. 2 and 3 above, but for the transistors 9us and 9v that perform the combinatorial operation shown in FIG. The transistor 911'+9V' of the switching circuit 9 can be configured as shown in FIG.

The other configurations and operations are the same as those of the first embodiment shown in FIGS. 2 and 4 described above, so their explanations will be omitted.

As is clear from the above explanation, the TV/VTR mode can be switched using exactly the same operation as the channel selection operation, which is extremely convenient when using a connected VTR, and eliminates the risk of erroneous operation. .

In addition, in terms of the number of mechanical parts, there is no need to provide extra switches such as switches for TV/VTR mode switching, and assembly is easy and it is easy to change conventional models, and the external panel surface is unified and simple. It becomes a good thing, and the design is also good.

In addition, since the display is clearer than conventional mode changeover switches, there is no chance of misidentification.

Note that the present invention is not limited to the above-mentioned embodiment, and for example, at least one of the band changeover switches 231, etc. may be provided with four changeover terminals, and one of them may be used as a VTR mode changeover terminal. .

Also, regarding 2 or more band switching switches,
A configuration may also be adopted in which a switching terminal is provided.

Furthermore, when using a TV receiver without connecting a VTR, you can select as many channels as there are channel selection operation buttons by switching all band selection switches to terminals other than the VTR selection terminal. Of course.

[Brief explanation of the drawing]

Fig. 1 is a front view showing the appearance of the operating section of a conventional TV receiver, Fig. 2 is a circuit diagram showing a first embodiment of the present invention, and Fig. 3 is a TV receiver of the first embodiment. FIG. 4 is a front view showing the appearance of the operating section of the second embodiment, and FIG. 4 is a circuit diagram showing the main parts of the second embodiment.

Claims (1)

[Scope of utility model registration request] It has a plurality of channel selection switches and a band changeover switch connected to each of these channel selection switches, and at least one of the plurality of hand changeover switches is configured to change the playback mode of the video tape recorder. A terminal is provided as a switching terminal, and the band switching switch is switched to the video tape recorder playback mode switching terminal, and the playback mode of the video tape recorder is changed according to the ON operation of the channel selection switch connected to the band switching switch. A television receiver characterized in that it is configured to perform switching.