JPS6056014B2 - Tuner channel selection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a sequential channel selection device in a television tuner or the like.

[Background of the invention]

Conventionally, channel selection operations on television receivers, etc., have been performed by pressing a channel selection button corresponding to a channel number, by sequentially rotating a channel selection knob, or by sequentially switching channels using a remote control device, etc. Ta.

Of course, this method was sufficient in normal cases, but as the number of channels increases and the program content becomes richer, channel selection becomes quite complicated, and furthermore, when it comes to commercials, When you want to temporarily check the program contents of other channels or search for a necessary program, using the conventional method described above is not only complicated, but also complicated. It is extremely difficult to return to the original channel in a short period of time after checking all the program contents of other channels, and there is a high risk of malfunction due to erroneous operation.

Therefore, a channel selection device has been proposed that can check all the program contents of other channels required in a short time with simple operations, that is, can perform one round selection. This is a block diagram showing an example of a device. In this figure, 1 is a tuner sequential selection device, which can select 12 channels, the selection corresponding to those channels has buttons, and the sequential selection is performed by a sequential control signal. It is configured to allow channel switching.

2 is a control circuit, 3 is a hexadecimal counter, 4 is a clock generator, 5 is a switch for starting operation, and 6 is a forward control signal input terminal.

Next, the operation of this channel selection device will be explained.

Now, when the switch 5 is pressed to perform one-round selection, the control circuit 2 starts operating, sends an operating signal to the clock generator 4, puts the clock generator 4 into the operating state, and receives a clock from the clock generator 4. Be open to the pulse. The control circuit 2 supplies this clock pulse to the hexadecimal counter 3 and the sequential channel selection device 1, whereby the sequential channel selection device 1 starts the sequential channel selection operation from the channel selected at that time. Switching to the next channel one after another.

The time interval at which channels are switched at this time is
It is determined by the period of the clock pulse from the clock generator 4, and is set to the time required for the viewer to confirm the content of the program on the switched channel, for example, from one to several seconds.

On the other hand, the counter 3 also increments according to the clock pulses supplied to the counter 3, and when 12 clock pulses are supplied, the counter 3 outputs an output signal! occurs.

This output signal is sent to the control circuit 2, which accordingly stops accepting clock pulses and
The hexadecimal counter 3 is reset and the supply of clock pulses, ie, forward control signals, to the terminal 6 is stopped. 4. Therefore, each time the switch 5 is pressed, 12 clock pulses are supplied from the terminal 6 to the tuner's sequential tuning device 1 as a sequential control signal.
Starting from the channel selected at that time, it sequentially cycles through other channels, returns to the original channel, and stops tuning.

Therefore, the user of the television receiver can receive all the channels in sequence at predetermined intervals by simply pressing switch 5 when necessary, check the program contents, and then return to the original. You can then switch back to the current channel, allowing you to decide whether to stay on that channel or switch to another channel.

Therefore, it is possible to perform one round of channel selection extremely easily without operating all the channel selection buttons in a short time or operating a remote control at a predetermined timing as in the conventional case.

FIG. 8 shows an example of the control circuit 2 in the conventional example shown in FIG. 13 and 14 are resistors and capacitors forming a differential circuit, 21 and 22 are NAND circuits forming a flip-flop for storing or latching input signals, and 23 and 24 are NAND gates.
circuit, 24a is its output terminal, 25 is an inverter, 32
is an input terminal to which an output signal from the hexadecimal counter 3 is supplied; 33 is an output terminal for supplying clock pulses to the hexadecimal counter 3; 42 is an output terminal for supplying an operating signal to the clock generator 4; 43 is an input terminal for receiving clock pulses from the clock generator 4.

Next, the operation of this circuit will be explained. Figure 9 shows the 8th
The waveforms of signals in each part of the circuit shown in the figure are shown.

First, when the input level of the terminal 11 becomes ゜゜0゛ due to the signal from the switch 5, the output of the NAND circuit 21 becomes ゜“
1, and this output is N. It is latched by AND circuits 21 and 22. Note that at this time, in the initial state, NA
It is assumed that the output of the ND circuit 21 is "0", and the output of the NAND circuit 22 is "01". NAND circuit 2
1 becomes 66r', the output terminal 42
A signal is supplied to the clock generator 4 from , so that an input terminal 43 is supplied with a clock pulse.

At this time, since one input of the NAND circuit 23 is at "1" like the terminal 42, a clock pulse appears at the output of the NAND circuit 23 due to the clock pulse from the terminal 43, and the falling part of the clock pulse appears at the output of the NAND circuit 23. After being differentiated by the well 13 and the capacitor 14 and inverted by the inverter 25, a positive progressive control signal having the same period as the clock pulse supplied to the terminal 43 and having a short width is sequentially sent from the terminal 12 to the tuning device 1. The currently selected channel is sequentially switched to the next channel in a short switching time, and the channel remains on that channel for a predetermined period of time.

Since the control signal appearing at this terminal 12 is simultaneously supplied from the terminal 33 to the input of the hexadecimal counter 3, the 12th control signal is applied to the output terminals 12 and 33 after the signal is applied to the start input terminal 11. When the signal appears, the hexadecimal counter 3 generates an output signal, which is supplied from the input terminal 32 to the NAND circuit 24, and the output terminal 24a of the NAND circuit 24 is connected to the signals at the output terminals 12, 33 and the input terminal 32.
When both of the signals of the
In addition to one of the inputs of the D circuit 22, the latch state is inverted and the output of the NAND circuit 21 is
The output of 2 is held at ゜゜1゛.

As a result, the signal at one input of the NAND circuit 23 and the terminal 42 becomes 0, the clock generator 4 stops operating, and the clock pulse supplied to the terminal 43 also disappears.
The supply of control signals to the output terminals 12 and 33 is also stopped, and the channel switching operation is stopped.

Therefore, according to this conventional example, by pressing the switch 5 for a moment, it is possible to perform one round selection of stations at any time, and decide whether to continue receiving reception on the same channel or to switch to another channel. be able to.

It goes without saying that at this time, switching to another channel is performed by operating a channel selection button, a channel selection knob, a remote control device, etc., as in the conventional case.

However, with this conventional channel selection device, for predetermined channels, one round of channel selection is performed anyway, regardless of the state of each channel. Channels whose broadcasts cannot be received, so-called empty channels, may be faithfully selected due to reasons such as the area is not included in the service area, etc., and the channels are selected at predetermined time intervals. There is a problem in that it requires wasted time for the station, and it is not possible to eliminate the discomfort caused by reception of noise (image noise and audio noise) caused by selecting an empty channel for a predetermined period of time.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a channel selection device that solves the above-mentioned problems of the prior art and allows sufficiently efficient and comfortable channel selection even if there are empty channels. .

[Summary of the invention]

In order to achieve this object, the present invention is characterized in that the received signal of each channel selected one after another in a round selection is checked, and the channel is fast-forwarded depending on the state of the received signal. .

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A tuner selection device according to the present invention will be described in detail below with reference to illustrated embodiments.

FIG. 1 is a block diagram showing an embodiment of the present invention, which differs from the conventional example shown in FIG. 7 in that a reception determination circuit 7 is provided, and the other configurations are the same as in the case of FIG. 7. Similarly,
Therefore, the basic operation of the channel selection device is the same as that of the channel selection device shown in FIG. When the channel is switched to, the reception determination circuit 7 determines whether or not the broadcast can be received on that channel based on the AGC voltage, AFC voltage, horizontal and vertical synchronization coincidence signals of the image receiving circuit, or a combination thereof. If there is no broadcast station on that channel or the electric field strength is insufficient, a fast forward pulse is generated in addition to the normal forward control signal to immediately perform the switching operation and instantly switch to the next one. It is now possible to switch channels.

This operation continues on any channel unless a sufficient signal is received on that channel;
Channels are sequentially switched to perform one-round selection.

Therefore, according to this embodiment, the sequential channel selection device 1 performs one round of channel selection by operating the switch 5, as in the conventional example shown in FIG. 7, and easily selects all other channels. Not only can you check the program, but you can also use the fast-forward operation to instantly switch to the next channel on channels where broadcasts cannot be received, so-called empty channels, and check the programs on other channels by performing a round of tuning in a short time. In addition, it is possible to eliminate the inconvenience of having to tune in to empty channels at predetermined time intervals.

FIG. 2 shows an example of the control circuit 2 in the embodiment of FIG. 1, and parts that are equivalent or the same as those in FIG. 8 are given the same reference numerals. In FIG. 2, 26 is an inverter;
26a is its output conductor, 27 and 28 are NAN for gate
D circuit, 28a is its output conductor, 29a, 29b are falling signal trigger type monostable circuits, 29c, 29d are their output conductors, 71 is a voltage comparison circuit, 71a is its output conductor, 72 is a reference voltage source, 73 is a comparison input terminal to which a signal corresponding to the electric field strength of the received signal from the receiving circuit is applied.

Next, the operation of this circuit will be explained with reference to FIG. As described in FIGS. 8 and 9, when a start signal is applied to the input terminal 11, a sequential control pulse appears at the output of the inverter 25, and the inverter 26, NAND
Control signals are sequentially sent from the output terminals 12 and 33 to the channel selection device 1 and the hexadecimal counter 3 via the circuit 27, and the channels are switched one after another.
A transmission voltage proportional to the electric field strength of the received signal is applied from the comparator circuit 71, and the comparator circuit 71 generates an output "゜0゛" on the output conductor 71a only when this voltage becomes higher than the voltage of the reference voltage source 72. do.

Therefore, by selecting the voltage of the reference voltage source 72 to an appropriate value, the electric field strength to be determined as an empty channel can be arbitrarily set.

Therefore, when the electric field strength of the switched channel has reached a predetermined value or more, the voltage at the terminal 73 only decreases for a very short time at the time of switching.
The voltage of 1a also momentarily becomes ゜゜1゛. At this time, the pulses appearing at the output terminals 12 and 33 are delayed by a predetermined time by the monostable circuits 29a and 29b, as shown in 29d in FIG. Coinciding with the pulse in time, N. AN
The output voltage of the output conductor 28a of the D circuit 28 remains at "1", and therefore, the pulses supplied to the output terminals 12 and 33 by the NAND circuit 27 are generated in the output conductor 26a of the inverter 26. The only pulses produced from the clock pulses supplied to the input terminal 43 are the same.

However, due to the pulse of this conductor 26a, the NAN
When switching to the next channel using the pulses sent from the D circuit 27 to the output terminals 12 and 33, that is, the sequential control signal, if the channel is empty and radio waves with sufficient electric field strength cannot be received. , only a voltage lower than the voltage of the voltage source 72 is supplied to the terminal 73, and even after switching to the output conductor 71a, the output ゛1゛ remains generated, and the monostable circuits 29a and 29b delay the output from the inverter 26. Control signal by pulse and NAN
D circuit 28 generates a matching condition, and a pulse is generated on output conductor 28a, causing N. It is applied to AND circuit 27 to generate additional pulses at output terminals 12, 33, causing immediate switching to the next channel.

In other words, fast forwarding is performed. In this state, there are two channels, the second, third and fifth from the left in Figure 3, where sufficient electric field strength cannot be obtained.
Three channels are shown as being present followed by one channel. At this time, the NAND circuit 28
Of course, the fast-forward control signal additionally supplied from the terminal 33 is also supplied to the hexadecimal counter 3 from the terminal 33, so even if there is an empty channel, the channel always returns to the first one and the one-round selection stops. do.

Therefore, according to this embodiment, it is possible to perform one-round selection in which only receivable channels are sequentially selected, and there is no need to preset depending on the channel status, and it is possible to automatically select channels that have finished broadcasting, etc. You can check the contents of the program even more quickly,
Moreover, it can be done comfortably.

FIG. 4 shows another embodiment of the present invention, in which when a necessary channel is found during one round selection operation, reception is immediately stopped on that channel and reception can be continued. be.

This embodiment differs from the embodiment shown in FIG. Immediately stops supplying the forward control signal to the channel selection device 1, and starts the hexadecimal counter 3.
is configured to reset and return to the initial state regardless of the count state, and other configurations and operations are the same as in the embodiment shown in FIG.

That is, during a commercial or the like, when the switch 5 is pressed to start one-round channel selection operation, the stop input switch 8 is pressed immediately after the channel with the desired program content is selected.

As a result, the control circuit 2 stops the operation signal to the clock generator 4, sends a reset signal to the hexadecimal counter 3, and stops sending out the forward control signal.

Therefore, the first round selection operation stops while the current channel is still selected, so the channel selection is performed again after the first round selection is completed and the original channel is returned to, as in other embodiments. This eliminates the need for selecting a desired broadcasting station, making it easier and faster to select a desired broadcasting station.

Thereafter, a round channel selection operation will be performed starting from this newly selected channel. Fifth
The figure shows an example of the control circuit 2 in the embodiment of FIG. 4, in which the same or similar parts as in the embodiment of FIG. 2 are denoted by the same reference numerals, and parts not particularly necessary for operation are omitted.

In FIG. 5, 82 is an input terminal to which the stop signal from the switch 8 in FIG. It is an output terminal. Note that in this embodiment, one of the N
A three-input one is used as the AND circuit 22, and the output of the monostable circuit 83 is supplied to the increased inputs.

Next, the operation of this circuit will be explained with reference to the waveform diagram in FIG.

Assume that a start signal is applied to the input terminal 11, and the fourth desired broadcasting station channel, including empty channels, is selected.

Therefore, the user of the television receiver incorporating this channel selection device should immediately press the switch 8 to connect the input terminal 82.
A "0" signal is supplied to the terminal 82. The signal at the terminal 82 triggers the monostable circuit 83 to output a pulse of a predetermined width, that is, to generate it at the terminal 34.

As a result, the output of the NAND circuit 22 becomes "1", and as a result, the output of the N.AND circuit 21 returns to "0".

Therefore, the output of the terminal 42 also becomes "0", the clock generator 4 stops, and the one-round tuning operation stops.

At the same time, the ゜゜0゛ signal generated at the terminal 34 is supplied to the reset input of the hexadecimal counter 3, and the hexadecimal counter 3 is reset and returned to its initial state. As a result of the above operations, the station selection operation is stopped when an arbitrary channel is reached, and the subsequent station selection operation is prepared to be performed starting from that channel.

Note that the monostable circuit 83 generates a signal with a necessary time width regardless of the operating state of the switch 8, and the NAND circuit 2
This is to ensure that the flip-flop consisting of 1 and 22 and the hexadecimal counter 3 are reset, and may be replaced with any means that can satisfy this condition. Further, in all of the above embodiments, the sequential channel selection device 1 is described as having a 12-channel selection type, and therefore the counter 3 is also in 12 decimal notation. However, the present invention is not limited to this, and any number of channels can be selected. The number of channels can be as follows.

Furthermore, in the above embodiments, the channel switching operation was explained as being in the forward direction, but the present invention is not limited to this, and the forward direction and reverse direction can be switched or used in combination. , it is easy to control the clock generator 4 to change the period of the clock pulse and change the switching time to add functions such as fast forwarding and slow forwarding, thereby obtaining a tuning device with even better operability. be able to.

Furthermore, even if the sequential channel selection device 1 is not used, an appropriate conversion circuit can be used to convert the sequential control signal or the hexadecimal counter 3 into a direct channel selection signal, and this signal can be used to select a channel in correspondence with the channel selection button. It is also possible to supply the signal to the station equipment and automatically switch channels; for example, a 4-bit 12-line conversion circuit may be used for this purpose.

〔Effect of the invention〕

As explained above, according to the present invention, all the programs of a large number of channels can be checked in a short time with extremely simple operations, eliminating the need for complicated operations and wasted time unlike the conventional technology. .

In addition, even if a remote control device is used, it only requires a simple command signal and simple operation, and since it switches to all channels, it is possible to perform one round of tuning without having to operate for a long time, and it is easy to add a remote control device. It has the advantage of being able to live in

Moreover, if you cannot receive comfortable reception or there is a channel that does not have reception radio waves, you can automatically skip over these channels and switch, further shortening the time required for one round selection. This eliminates the discomfort of selecting empty channels one by one, and allows for more comfortable operation.

Furthermore, when a desired program channel is selected, that channel can be stopped immediately, further shortening the channel selection time.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a channel selection device according to an embodiment of the present invention, FIG. 2 is a wiring diagram showing an example of a control circuit that is the main part of the device, FIG. 3 is a waveform diagram for explaining its operation, and FIG. FIG. 4 is a block diagram of a channel selection device according to another embodiment of the present invention, FIG. 5 is a wiring diagram showing an example of its control circuit, FIG. 6 is a waveform diagram for explaining its operation, and FIG. 7 is a conventional channel selection device. FIG. 8 is a block diagram showing an example of a channel selection device, and FIG. 8 is a wiring diagram showing an example of its control circuit.
FIG. 9 is a waveform diagram for explaining the operation. 1...Sequential tuning device for tuner, 2...
・Control circuit, 3... Decimal counter, 4...
... Clock generator, 5 ... Start switch, 7 ... Reception judgment circuit, 8 ... Stop switch.

Claims (1)

[Scope of Claims] 1. A sequential channel selection circuit that operates sequentially based on a clock signal, etc., a counter having a count equal to the number of selectable channels, and a control circuit that supplies a clock signal to the counter and the sequential channel selection circuit. a memory circuit for supplying an operation signal to the control circuit to start supplying a clock signal; and a switch for supplying a start signal to the memory circuit, and supplying the output of the counter to the reset input of the memory circuit. In a tuner selection device that automatically sequentially selects all selectable channels starting from an arbitrary channel and then stops the selection operation at the starting channel, the tuner receives the means for detecting the detected signal, means for comparing the output of the detecting means with a reference voltage, and means for generating an additional clock signal having a shorter period than the clock signal, the clock signal having a predetermined value on the selected channel. A tuner tuning device characterized in that, when the above received signals cannot be obtained, an additional clock signal is supplied to the sequential tuning circuit and the counter in addition to the clock signal. 2. The tuner channel selection device according to claim 1, characterized in that each reset input of the memory circuit and the counter is provided with a switch for generating a common stop signal.