JPS596032Y2 - Channel center couch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a channel selection device for a signal transmission device having a plurality of channels, such as a television receiver.

For example, when switching and selecting channels on a television receiver using a remote control, a system has been proposed in which channels with no broadcast waves (transmission signals) are skipped in order to make the selection quickly and easily.

There is a conventional channel selection device as shown in FIG. 1 which skips over channels where there is no broadcast wave.

That is, in FIG. 1, 1 is the video signal system of the television receiver.

This video signal system 1 is constructed in exactly the same way as the conventional one, with 1a being an antenna, 1b being a tuner, and 1C being a tuner.
is a video intermediate frequency amplifier, 1d is a video detector, 1e is a video amplifier, and 1f is a cathode ray tube.

Moreover, between the terminals 2a and 2b, for example, 50Hz, 100Hz
A commercial power source (2) is supplied, and this terminal 2a is connected to one input terminal of the stabilized power supply circuit 3, and the terminal 2b is connected to the stabilized power supply circuit 3 via a switch 4 that is turned on and off by a plunger 15d, which will be described later. Connect to the other input terminal.

The output terminal of this stabilized power supply circuit 3 is connected to the respective power supply terminals of the tuner 1b, the video amplifier 1C, the video detector 1d, and the video amplifier 1e.

Further, 5 is a motor for rotating the channel shaft of the tuner 1b and switching channels.

One end of this motor 5 is grounded, and the other end is connected to the output terminal of the stabilized power supply circuit 3 via a switch 6 that is turned on and off by a plunger 14, which will be described later.

Furthermore, the output signal of the video detector 1d is supplied to the synchronization separation circuit 7.

The power supply terminal of this synchronous separation circuit 7 is connected to the output terminal of the stabilized power supply circuit 3.

Here, this synchronization separation circuit 7 separates a synchronization signal from the broadcast wave of the selected channel and outputs it.

The output signal of this synchronization separation circuit 7 is supplied to a broadcast wave discrimination circuit 8.

Here, the broadcast discrimination circuit 8 has an input terminal connected to the anode of the diode 8a, and the cathode of the diode 8a is grounded through a parallel circuit of a capacitor 8b and a resistor 8C, and an output terminal is derived from the cathode of the diode 8a. There is.

In this broadcast wave discrimination circuit 8, the synchronization signal from the synchronization separation circuit 7 is rectified by a diode 8a, and the rectified output is smoothed by a capacitor 8b and a resistor 8C.

Therefore, in this broadcast wave discriminating circuit 8, the output terminal becomes high potential only when the synchronizing signal is supplied, that is, at a certain point in time of the broadcast wave.

The output terminal of this broadcast wave discriminating circuit 8 is connected to the base of an npn type transistor 9, the emitter of the transistor 9 is grounded, and the collector is connected to the output terminal of the stabilized power supply circuit 3 via a resistor 10.

Therefore, this transistor 9 is conductive only when the output terminal of the broadcast wave discrimination circuit 8 is at a high potential, that is, at a certain point in time of the broadcast wave.

The collector of this transistor 9 is connected to the reset terminal 11a of the memory circuit 11.

Further, 12 is a remote control signal receiving circuit.

This is a crystal microphone 12a that receives ultrasonic waves from a remote control ultrasonic generator (not shown).One end of the crystal microphone 12a is grounded, and the other end is connected to an output terminal via an ultrasonic amplifier 12b and a detection circuit 12C. It is connected.

Further, the power terminals of the ultrasonic amplifier 12b and the detection circuit 12C are connected to the output terminal of the stabilized power supply circuit 3.

Therefore, in this remote control signal receiving circuit 12, when ultrasonic waves are supplied to the crystal microphone 12a, a high potential output signal is obtained at the output terminal.

The output terminal of this remote control signal receiving circuit 12 is connected to the set terminal 10b of the memory circuit 11.

Here, the memory circuit 11 connects the reset terminal 11a and the set terminal 11b to diodes 11C and 11B, respectively.
The cathodes of diodes 11C and 11d are connected to each other, the connection point is connected to the base of transistor 11e, the emitter of transistor 11e is grounded, and the collector of It is connected to the output terminal of the stabilized power supply circuit 3 via the resistor 11f, and the collector of the transistor 11e is connected to the base of the transistor 11h via the resistor 11g, and the emitter of the transistor 11h is grounded. , the collector of the transistor 11h is connected to the output terminal of the stabilized power supply circuit 3 via the resistor 11i, and the anode of the diode 11k is connected via the collector resistor 11j of the transistor 11h, and the cathode of the diode 11k is connected to the output terminal of the stabilized power supply circuit 3 via the resistor 11i. 1
1 C, and an output terminal 11 l is led out from the collector of the transistor 11 h via a resistor 11 m.

In this memory circuit 11, when the set terminal 1lb becomes a high potential, this voltage is supplied to the base of the transistor 11e via the diode 11d,
e becomes conductive.

Therefore, the base of transistor 11h is transistor 1
1e to ground, the transistor 11h becomes non-conductive, and the output terminal 11l becomes a high potential.

Also, at this time, the voltage at the output terminal 11l is supplied to the base of the transistor 11e through a series circuit of a resistor 11j and diodes 11k and 11C.

Therefore, even if the set terminal 11b is at a low potential, the base of the transistor 11e remains at a high potential.

That is, the signal supplied to the set terminal 11b is stored.

Also, the above-mentioned transistor 9 becomes conductive, and the reset terminal 11
When a becomes a low potential, the anode of the diode 11C becomes a low potential, the base of the transistor 11e becomes a low potential, the transistor 11e becomes non-conductive, the transistor 11h becomes conductive, and the output terminal 111 becomes low. potential, and the memory in the memory circuit 11 is canceled.

Furthermore, the output terminal 111 of the memory circuit 11 is connected to the base of the transistor 13, the emitter of the transistor 13 is grounded, and the collector of the transistor 13 is connected to the plunger 14.
It is connected to the output terminal of the stabilized power supply circuit 3 via.

Therefore, when the output terminal 11l of the memory circuit 11 is at a high potential, the transistor 13 becomes conductive and current flows through the plunger 14.

This plunger 14 turns the switch 6 on and off, and during the period when current is flowing through the plunger 14, the switch 6
Turn on.

That is, the output of the memory circuit 11 becomes a control signal for switching the channel of the tuner 1b.

Further, 15 is a switch circuit, and 16 is a power supply circuit for supplying power to the switch circuit 15.

Here, the switch circuit 15 is an npn type transistor 1
Ground the emitter of 5a and connect the collector with resistor 15b
The emitter of an npn transistor 15C is grounded, the collector is connected to the output terminal of the power supply circuit 16 via a plunger 15d, and the collector of the transistor 15a is connected to a resistor. The collector of transistor 15C is connected to the base of transistor 15C through resistor 15e, and the collector of transistor 15C is connected to resistor 15f.
connected to the base of the transistor 15a via
The output terminal of the power supply circuit 16 is grounded through a parallel circuit with a series circuit of a capacitor 15g, a resistor 15h, a capacitor 15i, and a resistor 15j, and the bases of the transistors 15a and 15C are connected to a diode 1.
The anodes of diodes 15k and 15l are connected to each other, and the connection point is connected to the capacitor 15i and the resistor 15j.
Connect to the connection point with
The connection point with 5i is grounded via an automatic reset type switch 15m.

Here, transistors 15a and 15C constitute a flip-flop circuit.

In this switch circuit 15, when one of the transistors 15a and 15C is conductive, the other becomes non-conductive, and by turning on the switch 15m, the capacitor 15i
discharges and generates a trigger pulse, this state is reversed,
Further, when the transistor 15C is conductive, a current flows through the plunger 15d and the switch 4 is turned on.

In addition, the power supply circuit 16 connects the primary winding 16 b of the transformer 16 a between the connection point between the terminal 2 a and the stabilized power supply circuit 3 and the connection point between the terminal 2 b and the switch 4 .
One end of the secondary winding 16C of a is grounded, the other end is connected to the anode of a diode 16d, the cathode of the diode 16d is grounded via a capacitor 16e, and the output terminal is led out from this cathode. be.

This power supply circuit 16 outputs a DC voltage regardless of the state of the switch 4.

Furthermore, although not shown, the structure of other television receivers is the same as the conventional one.

According to the example in FIG. 1, for example, the transistor 15
When a is conductive and transistor 15C is non-conductive, and switch 4 is off, by turning on switch 15m, the states of transistors 15a and 15C are reversed, transistor 15C is conductive, and the plunger is turned off. 15h, a current flows, switch 4 is turned on, commercial power is supplied between terminals 2a and 2b to stabilized power supply circuit 3, and stabilized DC voltage is supplied to video signal system 1.
A television image is received.

Next, ultrasonic waves for remote control are supplied, and when the remote control signal receiving circuit 12 outputs, the output terminal 11l of the memory circuit 11 becomes high potential, and the transistor 13 becomes conductive, so a current flows through the plunger 14 and the switch is switched on. 6 turns on, motor 5 rotates, and tuner 1
b channel is switched.

Here, if there is no broadcast wave in the switched channel, the transistor 9 is non-conductive, and the memory circuit 11 stores the output signal from the remote control signal receiving circuit 12, so this memory The signal from circuit 11 causes transistor 13 to remain conductive, and motor 5 continues to rotate.

Furthermore, if there is a broadcast wave on the switched channel, the transistor 9 becomes conductive, the memory of the memory circuit 11 is canceled, and the output terminal 111 becomes a low potential, so the transistor 13 becomes non-conductive, and the plunger No current flows through the motor 14, the switch 6 is turned off, and the rotation of the motor 5 is stopped.

As described above, according to the example shown in FIG. The channel automatically switches to the next channel, and this operation is repeated until a channel with broadcast waves is selected.

Therefore, when selecting stations by remote control,
It skips over channels where there are no broadcast waves, and this skip is done by detecting the presence or absence of broadcast waves, so for example, when only some broadcast stations are broadcasting, such as early in the morning or late at night, it is possible to jump over channels that do not have broadcast waves. Since the channel is also skipped after the broadcast ends, it is possible to always select a channel quickly and easily.

However, in the case of the example shown in Figure 1, for example, when all the broadcast stations are not broadcasting early in the morning or late at night, when the antenna wire is disconnected, or when the video signal system 1 breaks down, the broadcast waves cannot be transmitted to all channels. If this cannot be obtained, all channels are skipped, and the motor 5 continues to rotate without stopping, which is undesirable.

In view of this, the present invention provides a channel selection device that eliminates the above-mentioned conventional drawbacks.

Hereinafter, an embodiment of the channel selection device according to the present invention will be described with reference to FIG. 2. Parts corresponding to those in the example shown in FIG.

In FIG. 2, a time measuring circuit 17 is inserted between transistor 9 and memory circuit 11. In FIG.

Here, the time measurement circuit 17 grounds the output terminal of the stabilized power supply circuit 3 through a series circuit of a resistor 17a and a capacitor 17b, and connects the connection point between the resistor 17a and the capacitor 17b to the ground through the diodes 17C and 17d. The cathode of the diode 17C is connected to the collector of the transistor 9, the cathode of the diode 17d is connected to the base of the transistor 17e, the emitter of the transistor 17e is grounded, and the cathode of the diode 17C is connected to the collector of the transistor 9.
The collector of 7e is connected to the diode 11C of the memory circuit 11.
It is connected to the anode of the

Here, the resistor 17a and the capacitor 17b form a time constant circuit, and the motor 5 connects the tuner 1b.
After an arbitrary period of time longer than it takes for the channel to complete one cycle, the charging potential of capacitor 17b reaches
7d and the forward direction drop voltage of transistor 17e.

Therefore, in this time measuring device 17, when the transistor 9 is non-conducting, the diode 17C is also non-conducting, the capacitor 17b is charged, and while the channel of the tuner 1b goes around, the transistor 9 is non-conducting. If the charging potential remains unchanged, the charging potential is the same as that of diode 17d and transistor
7e becomes larger than the sum of the forward voltage drops, and the transistor 17e becomes conductive.

Further, the collector of the transistor 11 h of the memory circuit 11 is connected to the anode of the diode 11 C via the resistor 11 j, and also connected to the anode of the diode 18, and the cathode of the diode 18 is connected to the collector of the transistor 9. Furthermore, the collector of the transistor 17e is connected to the cathode of the diode 15H, and the collector of the transistor 17e is connected to the cathode of the diode 15H.
The anode of the transistor 15C of the switch circuit 15
Connect to the base of

Note that the diode 11k of the memory circuit 11 in the example of FIG. 1 may be omitted.

The rest of the structure is the same as the example in FIG.

According to the present invention, when the remote control signal receiving circuit 12 outputs the same as in the example of FIG. 1, the transistor 13 becomes conductive and the motor 5 rotates, and when there is no broadcast wave on the channel, this state is maintained, and when there is a broadcast wave in the channel, the transistor 9 becomes conductive, and the collector potential of the transistor 11k is grounded via the resistor 11j, the diode 18, and the transistor 9, and the memory circuit 1
1 is cleared, the transistor 13 becomes non-conductive, and the rotation of the motor 5 is stopped.

In addition, if broadcast waves cannot be obtained on all channels due to a failure or the like, the transistor 17e of the time measuring circuit 17 becomes conductive when the channels complete one cycle, so that the collector potential of the transistor 11h changes to the resistor 11j and the transistor 17e. It is grounded via the transistor 17e, the memory of the memory circuit 11 is canceled, the transistor 13 becomes non-conductive, and the rotation of the motor 5 is stopped.

Furthermore, as the transistor 17e becomes conductive, the base of the transistor 15C of the switch circuit 15 is grounded via the diode 15n and the transistor 17e, and the transistor 15C becomes non-conductive, turning off the switch 4 and cutting off the power supply. .

Note that when there is a broadcast wave on the channel and the transistor 9 becomes conductive, the charge charged in the capacitor 17b is quickly discharged via the diode 17C and the transistor 9, so that the capacitor 17b is not charged in advance. Because of this, the time constant does not change.

As described above, according to the channel selection device of the present invention, it is possible to quickly and easily select a channel by skipping over channels that do not have broadcast waves, and it is also possible to skip channels when broadcast waves cannot be obtained on all channels due to a malfunction or the like. Since the motor 5 can be stopped and then the power can be cut off, there is no problem such as the motor 5 continuing to rotate.

In the above example, the present invention was applied to a television receiver, but it goes without saying that the present invention can be applied to various signal transmission devices having a plurality of channels.

Further, the channel selection device according to the present invention is not limited to the above-described embodiments, and may take various other configurations without departing from the spirit of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a conventional example, and FIG. 2 is a diagram showing an embodiment of a channel selection device according to the present invention. 1 is a video signal system of a television receiver, 2a and 2b are terminals, 4 and 6 are switches, 5 is a motor, 7 is a synchronization separation circuit, 8 is a broadcast wave discrimination circuit, 9 and 13 are transistors, and 11 is a storage circuit. , 12 is a remote control signal receiving circuit, 14 is a plunger, 15 is a switch circuit, 17
is a time measurement circuit, and 18 is a diode.

Claims (1)

[Scope of utility model registration request] A tuner that sequentially switches and selects a plurality of channels while a control signal is being supplied, a remote control signal receiving circuit, a television signal discriminating circuit that determines the presence or absence of a received television signal, and a flip-flop structure. a storage circuit that is set by the output from the remote control signal receiving circuit and reset by the output from the television signal discriminating circuit, the output of which is used as the control signal; and a storage circuit that is controlled by the output of the television signal discriminating circuit. A channel selection device comprising: a time measurement circuit that resets the storage circuit after a predetermined time period longer than the time required to cycle through the plurality of channels after a received television signal ceases to exist.