JPS5947890B2 - Channel selection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a channel selection device that uses a counter to select a channel, and is capable of performing both sequential channel selection and direct channel selection using common circuit elements. The purpose is to provide a device that can do this.

As a method for selecting a channel in a television receiver, there is a method in which a pulse is applied to a counter at the time of channel selection, the pulse is counted, and a variable resistor is selected based on the counted output to switch the channel selection voltage.

In such a device, the mode of channel selection operation is sequential tuning, in which channels are switched up or down one channel at a time, starting from the currently tuned channel, and channel selection is performed in a sequential manner, in which channels are switched up or down one channel at a time, starting from the currently tuned channel. There are two possible methods: direct channel selection, in which you directly specify and select the channel you want to tune next, and it is necessary to selectively use one of them depending on the purpose.

However, since these two channel selection operations require different counter control methods, it is usually necessary to configure separate circuits for each operation, which increases the number of types of circuit elements and increases costs. It was thought that it would become

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems and provide a channel selection device that can perform both direct channel selection and sequential channel selection using common circuit elements in most parts. be.

Therefore, in the present invention, when the channel selection switch is operated during channel selection, one pulse is first generated from the first output terminal, and then one pulse is generated from the second output terminal to the channel to be selected. A control pulse generation circuit that generates the corresponding number of pulses is created using a microcomputer, etc., and for direct channel selection, the standard counter for channel selection is reset with the pulse from the first output terminal, and then The pulses from the second output terminal are counted to enable direct selection of the desired channel, and for sequential tuning, the pulses from the first and second output terminals are input to the reversible counter's up-count input terminal. 1 in addition to the down-count input terminal
This system is characterized in that the selected channels can be switched channel by channel.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram when wires are connected for direct channel selection, and FIG. 2 is a block diagram when wires are wired for sequential channel selection.

The same parts in both will be described with the same reference numerals.

Further, although an embodiment in which channel selection is controlled by remote control will be described here, the same applies to a case where a channel selection switch is provided on the receiver body.

First, in the figure, 1 is a counter type channel selection circuit, which includes a binary chibit reversible counter 2 that can count in both the up and down directions, and the count output of this reversible counter 2 is converted from binary to n-ary. The decoder 3 is equipped with a decoder 3 to perform tuning, and a tuning voltage presetting circuit 4 consisting of a group of variable resistors etc. in which tuning voltages corresponding to the number of channels desired to be tuned are preset. In response, one channel selection voltage is selectively taken out from the channel selection voltage preset circuit 4 and applied to a variable capacitance diode of an electronic tuner (not shown) to perform channel selection.

If a ring counter is used as the reversible counter 2, the decoder 3 can be omitted.

A publicly known channel selection circuit 1 can be used as the channel selection circuit 1 itself.

On the other hand, 5 is controlled by remote control.

This is a transmitter for commanding channel selection, and is equipped with a switch group 6 for command, and emits a remote control signal such as pulse-coded modulated infrared light or ultrasonic waves depending on which switch is operated. do.

This remote control signal is received by a receiving element 7 such as a PIN photodiode or a microphone, extracted and amplified only in a predetermined modulation band by a tuned amplifier circuit 8, and then detected and sliced by a waveform shaping circuit 9. The waveform is shaped into a predetermined pulse code.

This pulse code signal is input to the control pulse signal generation circuit 10 as a control signal.

The control pulse signal generation circuit 10 includes a code identification circuit 11 that identifies an input pulse code signal, and an R circuit in which a program for executing a predetermined format is written.
It is constituted by a microcomputer (for example, MN1404 manufactured by Kyoshita Denshi Kogyo Co., Ltd., manufactured by Kyoiku Co., Ltd.), which incorporates an OM 12 and an arithmetic processing circuit 13 that performs arithmetic processing according to a predetermined format.

Here, as the control pulse generation circuit 10, when one of the channel selection switches 6 for channel command is operated and a pulse code signal is generated, the control pulse generation circuit 10 first outputs the signal from the first output terminal 14 as shown in FIG. 3A. Generates one pulse like
Next, from the second output terminal 15, the number of channels corresponding to the channel to be selected is outputted from the second output terminal 15 as shown in FIG.
A program written in the ROM 12 is set so as to generate a pulse like B2.

Here, B1 is the channel selection switch 6□ for channel 1 command.
0 output pulses when is operated, B12 is 1 output pulse when the channel selection switch 61□ for channel 12 command is operated, B2 is channel 2
It is determined that 11 output pulses are generated when the command selection switch 62 is operated.

Of course, the channel at this time...1
2 indicates the arrangement order of the selected channels in the selected channel voltage preset circuit 4, and does not have to correspond to the first channel of the broadcast channel.

In addition, here, the pulse widths and intervals of pulses A, B1□...B2 are made different, but this is done so as to satisfy both the operability in sequential channel selection and the speed in direct channel selection. Moreover, it is designed to ensure reliable operation, and the pulse width and interval may be the same.

Such an operation format is achieved by writing in advance in the ROM 12 a program in which the code identification circuit 11 identifies the pulse code of the remote control signal and the arithmetic processing circuit 13 generates different pulses accordingly. This can be easily achieved.

In the device for direct tuning shown in FIG. 1, the first output terminal 14 of the control pulse generation circuit 10 is connected to the reset terminal 16 of the tuning circuit 2, and the second output terminal is connected to the countdown input terminal 17 at one of the count input terminals 22.

And reversible counter 2 is channel 1 in the reset state.
Set it to tune in.

In this way, when tuning channel 5, for example, when the tuning switch 65 is operated, the reversible counter 2 is first reset by the output pulse A from the first output terminal 14 of the control pulse generation circuit 10, and then the reversible counter 2 is reset. channel 5 by counting down by 8 channels using 8 pulses B5 from the second output terminal 14.
is selected.

The same applies to other channels.

FIG. 4 shows a flowchart of the processing procedure performed by the microcomputer in the control signal generation circuit 10 of FIG.

When the power is turned on, the flow starts (20) and initial values of the microcomputer's RAM are set (21).

The purpose is to determine the presence or absence of a signal from the waveform shaping circuit 9 in FIG. Therefore, the explanation will be omitted) and return to the input detection program (25).

If it is a channel selection signal, a channel reset signal, that is, signal A shown in FIG. 3 is output (24).

Then that input is set to channel selection "Channel 1"
(hereinafter referred to as CHl) (26); if so, jump directly to the input detection program (22); if not, rCH2; , if it is an instruction signal, N for outputting N channel down pulses is set to "11".
” and output N down pulses (30).
4).

If it is not an rcH2J instruction signal, it is determined whether it is an rcH3J instruction signal (28), and if it is an rcH3J instruction signal, N is set to "10" (31).

Similarly, if it is an rcH4J instruction signal, set N to "9".
If it is the rcH5J instruction signal, set N to "8", rcH
6. If it is an instruction signal, set N to "7", rCH7, if it is an instruction signal, set N to "6", rCH8, if it is an instruction signal, set N to "5", if it is an rcH9J instruction signal, set N to "5". "4"
If it is a “CHlo” instruction signal, set N to “3” and “C
If it is a "CHll" instruction signal, set N to "2", respectively (30) to (32), and if it is not rcHllJ in the setting of whether it is a "CHll" instruction signal, only rcH12 and the instruction signal remain. to set N to "1" (33).

Based on these outputs, channel down pulses are outputted by N channel down output means, and a jump is made to input detection (34).

That is, in this way, channel down pulses B2 to B1□ in FIG. 3 are output.

On the other hand, in the device for sequential channel selection shown in Fig. 2,
Tuning circuit 1 and control pulse generation circuit 10 exactly the same as in Fig. 1
Although other circuit elements are used, only the tuning switch 61゜6□1 is used as the tuning switch group 6 for the tuning command, and the first output terminal 14 of the control pulse generation circuit 10 is used for tuning. Only the connections are partially changed so that the count-down input terminal 17 of the reversible counter 2 of the circuit 1 is connected, and the second output terminal 15 is connected to the count-up input terminal 18.

In this way, when the tuning switch 1 is operated during tuning, the reversible counter 2 counts down one channel by one pulse A from the first output terminal 14 (at this time, the second Pulse B from output terminal 15 of
1 is 0 (You can select the channel one below.

Conversely, when the tuning switch 6□1 is turned off, the reversible counter 2 counts down by one channel by one pulse from the first output terminal 14, but then the second
By means of two pulses Bll from the output terminal 15 of , it is possible to count up by two channels, and eventually select a channel up by one channel.

Therefore, in this case, sequential tuning in the up direction and down direction can be realized using the two tuning switches 61.degree. 6.1.

Of course, if the connections between the first and second output terminals 14 and 15 and the count-up input terminal 17 and count-down input terminal 18 are reversed, the direction of channel selection will be reversed.

In this way, in this device, almost all of the circuit elements used are common, and by simply changing some of the connections, it is possible to freely select between direct tuning and sequential tuning. can be connected to.

Since the circuit elements can be shared by both, it is possible to reduce the number of these types, improve the mass production effect, and significantly reduce costs.

Particularly, when creating the control pulse generation circuit 10 using a microcomputer, the cost reduction effect of being able to use one program in common is greater than creating two types of programs.

In addition, since the remote control transmitter 5 and other parts can be shared, the printed circuit board itself can also be used, and the connection between the output terminals 14 and 15 and the counter 2 can be changed using jumper wires, etc. Another advantage is that you can switch between the two functions just by leaving it on.

Furthermore, even if the two functions of direct tuning and sequential tuning are achieved in this way, only two common output terminals are required from the control pulse generation circuit 10, so if this is configured with an IC element. Also, there is no need to increase the number of terminal pins, which is extremely effective in terms of design.

As detailed above, in the present invention, when the channel selection switch is operated, one pulse is first generated from the first output terminal, and then one pulse is generated from the second output terminal to the channel to be selected. When using a control pulse generation circuit that generates a corresponding number of pulses, when used for direct tuning, the reversible counter of the tuning circuit is reset by the pulse of the first output terminal, and the reversible counter of the tuning circuit is reset by the pulse of the second output terminal. When pulses are counted and used for sequential tuning, the pulses from the first and second output terminals are used to count the reversible counter in the countdown and up directions, making it easy to use the tuning circuit and control pulse generation. You can select one of the two tuning functions while keeping almost all the circuit elements and connections the same, such as the circuit and the input parts such as the remote control part.
It is possible to obtain an excellent channel selection device that can significantly reduce costs by reducing the variety of products by standardizing the circuit elements used.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIGS. 1 and 2 are block diagrams of a channel selection device in an embodiment of the present invention, FIG. 3 is a waveform diagram for explaining the operation of the device, and FIG. 4 is a waveform diagram for explaining the operation of the device. 1 is a flowchart showing the processing procedure of the microcomputer in FIG. 1...Tuning selection circuit, 2...Counter, 3
... Decoder, 4 ... Tuning voltage preset circuit, 5 ... Transmitter, 6 ... Tuning switch group, 7 ... Receiving element, 8...
Tuned amplifier circuit, 9... Waveform shaping circuit, 10...
... Control pulse generation circuit, 11 ... Code identification circuit, 12 ... ROM, 13 ...
・Elimination calculation processing circuit, 14.15...First and second output terminals, 16...Reset terminal, 17...
...Countdown input terminal, 18...Countdown input terminal.

Claims (1)

[Claims] 1. A reversible counter that counts count pulses is provided, and channel selection is performed by selecting a channel selection voltage according to the count output of the reversible counter and applying it to an electronic tuner. When a channel selection circuit is operated and a channel selection switch is operated, one pulse is first generated from the first output terminal, and then the number of pulses corresponding to the channel to be selected is generated from the second output terminal. and a control pulse generation circuit that generates the reversible counter, the first output terminal of the control pulse generation circuit is connected to the reset terminal of the reversible counter, and the second output terminal is connected to one of the count input terminals of the reversible counter. or the first output terminal of the control pulse generation circuit is connected to one count input terminal of the reversible counter, and the second output terminal is connected to the other count input terminal of the reversible counter. A channel selection device featuring: 2. The channel selection device according to claim 1, wherein the control pulse generation circuit is configured by a microcomputer.