JPS5925489B2 - television receiver - Google Patents

Description

[Detailed Description of the Invention] Channel selection is performed by touching the selection button (touch type) or lightly pressing the button (button type) on the front panel of the &ζ television receiver using the electronic tuner. However, even with such a tuner, if you want to know the program contents of a plurality of other channels, it is necessary to repeat the channel selection operation of operating the corresponding channel selection button for each channel.

Therefore, it is relatively troublesome to know the program contents of other channels.

The channel selection operation is also troublesome. The present invention eliminates these drawbacks, and by operating the control switch once, channels are automatically selected and switched sequentially at regular intervals.
This simplifies the channel selection operation by automatically switching channels.

FIG. 1 shows an example of the essential parts of a television receiver according to the present invention, in which 1 is an electronic tuning tuner, 2 is a video detection circuit, and the tuner 1 has a desired tuning voltage obtained by the tuning device 10. V.

is supplied. The channel selection device 10 is provided with a plurality of switches (touch switch, push switch f, etc.) Sa-8n corresponding to a plurality of channel selection buttons, and a channel selection voltage V corresponding to the channel selected by these buttons.

a~-VEN is supplied to tuner 1 until the next channel selection.

Tuning voltage V corresponding to the channel.

is a plurality of volumes VRa provided as many as the number of channels.
~vRn.

Control transistors Q a =Q n are connected in series to these volumes vRa-vRn, and the output (logic -1-) of the ring counter 5 is selectively supplied only to the transistor Q corresponding to the selected channel.

The collector output of the control transistor Qa=Qn is supplied to the pulse oscillator 7 via the above-mentioned switch 5a=Sn.

The oscillator 7 starts oscillating when the input is ((l n), and the oscillation output is supplied to the clock terminal of the ring counter 5 through the OR circuit 8.

Therefore, assuming that the channel corresponding to switch Sa is currently selected, the output of terminal a of counter 5 is (
j l hs, all the outputs of other terminals b - n are ((
Q) m.

Next, when a channel related to switch Sn is selected in this tuning state, for example, by turning on switch Sn,
Oscillator 7 starts operating and counter 5 is driven.

As a result, ((l hs counter output changes sequentially, and when the it l ss counter output is obtained at terminal n, the transistor Qn turns on. At this time, the oscillator 70 oscillation operation stops and the transistor Qn turns on. is retained.

With this series of operations, the selected channel is set to switch S.
The channel can be switched to the channel corresponding to n.

Note that this channel selection operation is performed in an extremely short time.

Therefore, the oscillator 70 frequency is high. In addition to such a configuration, the present invention further includes a pulse generation circuit 20,
The ring counter 5 is also driven by this pulse.

Therefore, the pulse output Ps is supplied to the counter 5 through the OR circuit 8.

SW is a switch that controls the pulse generation circuit 20, and is provided, for example, on the front surface of the panel.

As shown in FIG. 2, the pulse generating circuit 21 has an RS flip-flop circuit 21, the output of which is supplied as a drive signal to an oscillator 22 composed of a pair of NAND circuits 22A and 22B.

The oscillation frequency is determined by the values of the resistor 23a and the capacitor 23b, and is selected so that the oscillation period is about 1 second in this example.

The oscillation output is supplied to an n-ary counter 25, and a carry pulse Pc is obtained when n pulses Ps are counted.

For example, if there are 12 selection buttons, the decimal counter 2
5 is used.

In this case, the number of channel selection buttons does not necessarily match the stations that can actually receive broadcasts.

The carry pulse Pc is supplied as a reset pulse to the reset terminal R of the flip-flop circuit 21 via the differentiating circuit 26, and the operation of the oscillator 22 is stopped by obtaining the carry pulse Pc.

Therefore, if the output of the flip-flop circuit 22 is supplied to the ring counter 5, pulses Ps are generated at intervals of approximately 1 second when the switch SW is turned on.
The counter 5 is driven every time .

The terminal output of any one of terminals a-n is it 1
When the time reaches 11, the corresponding channel is dynamically selected and the program content is displayed for one second.

Therefore, the channels change sequentially every second, and when there are 12 selection buttons as described above, the channels go through one cycle with 12 pulses Ps, and then the channel changes to the first selected channel. Stops when

In this way, the switch (start switch if you will)
By turning on the switch once, 12 channels are automatically switched, and the corresponding program content is displayed in sequence.

As explained above, according to the present invention, by simply operating the control switch SW only once, the channels are automatically selected and sequentially switched at regular time intervals, completing a cycle of channel switching; , the channel always returns to the one that was selected before turning on the switch SW.

Therefore, the contents of other programs can be known without touching the channel selection button, and the channel selection operation can be simplified.

Note that the oscillation frequency of the oscillator 22 can be arbitrarily selected.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an example of the present invention, and FIG. 2 is a system diagram of an example of its essential parts. 1 is an electronic tuning tuner, 20 is a pulse generation circuit, 15 is a ring counter, vo is a selected JdE voltage, 21 is an RS flip-flop circuit, 22 is an oscillator, and 25 is an n-ary counter.

Claims (1)

[Claims] 1. In a television receiver equipped with an electronic tuner in which the tuning state is maintained by the output of a ring counter that operates in conjunction with the operation of a plurality of tuning buttons,
A pulse generation circuit is provided that generates as many pulses as the number of channels that can be selected by the channel selection button, and its output drives the ring counter. A television receiver characterized in that the selected channels are cycled by operation.