JPS62219786A - Television channel selection system - Google Patents

Abstract

PURPOSE:To respond to various kinds of equipments only by changing the form of a channel selection data, by varying the oscillation signal frequency dividing ratio of a phase-locked loop supplying the channel selection data to the phase-locked loop, and performing a channel selection. CONSTITUTION:A local oscillation signal outputted from a VCO22 is devided with a prescribed frequency-dividing ratio at a prescaler 26, and is supplied to a programmable counter 27 in a PLL part 14, and is divided with an optional frequency-dividing ratio instructed by a personal computer. A phase comparator 28 performs the phase comparison between the output of the programmable counter 27, and a reference frequency signal from a reference oscillator 29, and obtains an error signal having a level corresponding to a frequency difference, and supplies it to the VCO22 as a tuning voltage through a low-pass filter 30. Therefore, the frequency of the local oscillation signal outputted from the VCO 22 is varied according to the frequency-dividing ratio of the programmable counter 27. In this way, it is possible to easily respond even when the kinds of television receivers are different only by changing the form of the channel selection data.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a television channel selection method, and more particularly to a method for selecting television signals in a television receiver or an up-down converter.

2. Description of the Related Art Conventionally, channel selection of a television receiver has been remotely controlled using a remote controller.

Remote controllers usually have a limited number of channels that can be selected, or are complicated to operate even if a large number of channels can be selected. In addition, the remote controller and television receiver I
The communication method with the iI machine varies depending on the model.

Recently, 0ATV (cable television).

In systems such as the IN5 (Advanced Information and Communication System), multichannel video transmission has been put into practical use via a cable network.Also, personal computers can be connected to other computers through data communication, and Systems that combine personal computers with telephones and televisions are also being put into practical use.

Problems to be Solved by the Invention Systems such as ATV (cable television) have a large number of channels, and conventional remote controllers have a limited number of keys and can only select a small number of channels, or cannot select multiple channels. Even if it were possible, there was a problem that the operation was complicated.

Furthermore, if the model of the television receiver is different, a remote controller corresponding to the model must be prepared, resulting in a problem of low versatility. Furthermore, there was a problem in that the remote controller could not be operated using a communication line.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a television channel selection system that solves the above-mentioned problems by converting a channel selection operation signal by keyboard operation or data communication into channel selection data.

SUMMARY OF THE INVENTION In the present invention, an up-down converter for television receiver or cable television reception uses a phase-locked loop.

A tuning operation signal inputted by keyboard operation or data communication is converted into tuning data, and this tuning data is supplied to the phase-locked loop to vary the oscillation signal frequency division ratio of the phase-locked loop. Select a station.

Operation In the present invention, the channel selection operation signal is supplied by the keyboard or data communication, and more stations can be selected than with a remote controller with a limited number of keys. It can also be compatible with various models.

Embodiment FIG. 1 shows a block system diagram of a first embodiment of the system of the present invention. In the figure, a television broadcast signal enters a terminal 10 and is supplied to a channel selection circuit section 11.

The television receiver has this channel selection circuit section 11 and monitor section 1.
2, the tuning circuit section 11 is divided into a tuner section 13, P
It is composed of an LL (phase locked loop) section 14, an intermediate frequency amplification section 15, and a detection section 16.

The television broadcast signal is amplified by the RF amplifier 20 of the tuner section 13, and then mixed with the local oscillation signal from the voltage-controlled oscillator (hereinafter referred to as rVcOJ) 22 by the mixer 21 to form an intermediate frequency signal. . After this intermediate frequency signal is band-limited by a bandpass filter 23, the intermediate frequency amplification section 1
5 and is amplified and supplied to the detection section 16. The video detection circuit 24 and the audio detection circuit 25 each obtain a video signal and a 2-channel audio signal from the intermediate frequency signal and supply them to the monitor unit 12, where the video and audio are reproduced.

The local oscillation signal output from the VCO 22 is frequency-divided by a prescaler 26 at a predetermined frequency division ratio and supplied to the programmable counter 27 of the PLL section 14, where it is divided at an arbitrary frequency division ratio instructed by a personal computer to be described later. It is surrounded. The phase comparator 28 compares the phase of the output of the programmable counter 27 with the reference frequency signal from the reference oscillator 29, obtains an error signal with a level corresponding to the frequency difference, and passes this through the low-pass filter 3o. te■c02
2 as a tuning voltage. Therefore, the VCO
The frequency of the output local oscillation signal 22 is varied according to the frequency division ratio of the programmable counter 27.

The programmable counter 27 described above is connected to a personal computer 41 via an interface circuit 40. Further, the personal computer 41 has a keyboard 42 and performs data communication with other personal computers etc. via an interface circuit 43 and a modem 44.

By the way, the personal computer 41 transmits channel selection data including 12-bit channel data shown in FIG. 2 (A>) and 12-bit status data shown in FIG. 2 (B) to the programmable counter 27 via the interface 40. do.

Channel data is the upper 4 pits I) u”-Do specifies the band, and depending on this value the frequency is 90 to 108M.
Hz low band, frequency 108 to 170 MHz mid band, frequency 170 to 222 MHz high band,
Each superband with a frequency of 222 MHz or higher is designated. Channel high of the next four bits D7-D4 and channel low of the lower four bits 1-D3-Do specify the 11 channels in each band. For example, when channel high is "1111" and channel low is "0101", the first channel is designated.

In the status data, bit D3 instructs the power on/off of the television receiver, bit D2 instructs switching between the television broadcast signal and the playback signal of the video tape recorder, and bit Do instructs the on/off of AFC. All other bits are set to 0''.

Furthermore, the programmable counter 27 transmits a 1-bit data reception confirmation signal ACK to the personal computer 41 via the interface circuit 40.

FIG. 3 shows a flowchart of one embodiment of the channel selection process of the personal computer 41. After the power is turned on, the personal computer 41 connects the interface circuits 40 and 43.
and perform initial settings for the modem 44, etc. (step 50).
. Thereafter, 12-bit channel data for initial setting is set in a predetermined register (step 51). This initial channel tp channel data is, for example, data instructing reception of one low band channel.

Next, it is determined whether it is a reset time such as power-on or system reset (step 52);
At the time of resetting, the level of the confirmation signal ACK is determined in step 53, and if this is the torque level and the programmable counter 27 has data, step 54 is performed.
The channel data set in the register is transmitted to the programmable counter 27. Similar processing is performed in steps 55 and 56 even when it is not the time of reset.

However, at the time of reset, status data is set in a predetermined register following step 54 (step 57).
), after the confirmation signal ACK is determined to be true (step 58), this status data is transmitted to the programmable counter 27 (step 59). That is, at the time of reset, the television receiver's power on/off, AFC on/off, etc. are switched.

After the execution of steps 56 and 59, the confirmation signal ΔCK is determined (step 60), where the confirmation signal AC
If K is a trubel and data reception by the programmable counter 27 has not been completed, the process moves to step 52, and if K is a trubel indicating completion of data reception, the process moves to step 61.

In step 61, it is determined whether or not a television receiver tuning operation signal has been received via the keyboard 42 or modem 44 and interface circuit 43. If this has been received, the process moves to step 62. In step 62, it is determined whether the above-mentioned channel selection operation signal instructs to select a channel or to end the reception, and in the case of the end of reception, the execution of the above processing is stopped; converts the operation signal into channel data (step 63),
After this, the process moves to step 52.

In this way, a channel selection operation signal can be obtained by keyboard operation or communication data via the modem 44, and a channel can be selected according to this operation signal. In this case, of the 12 bits of channel data, 256 combinations are possible with only 8 bits of channel high and channel low.

Furthermore, even if the model of the television receiver changes, this can be handled by changing the formats of the channel data and status data to match the model.

FIG. 4 shows a block system diagram of a second embodiment of the present invention.

In the figure, the same parts as in FIG. 1 are designated by the same reference numerals, and their explanations will be omitted. In FIG. 4, a CATV signal having a frequency of 50 to 450 M1-1z, for example, coming into a terminal 70 is supplied to a channel selection circuit section 71.

The tuning circuit section 71 includes an up/down converter 72 and P
It is roughly divided into LL section 73. This P L 1 circuit section 73
is the 1st r'1. Since the configuration is the same as that of the PLL circuit section 14, the same parts are given the same reference numerals and the explanation thereof will be omitted.

After the CΔTV signal is band-limited by the input filter circuit 74 of the up-down converter 72, it is passed to the first mixer 75.
It is mixed with the first station 2gS'fe oscillation signal from the VCO 76 to form an intermediate frequency signal having a predetermined frequency of 450M1-12 or higher.

After this intermediate frequency signal is amplified by the IF amplifier 77, the second mixing! 7B, the signal is mixed with the second local oscillation signal from the local oscillator 79 to generate, for example, the first oscillation signal of the television broadcast signal.
The frequency is converted to a signal with the same frequency as the channel (or second channel), and the television is received! 183.

The first local signal output from the VCO 76 is divided by a predetermined frequency division ratio by a prescaler 81 and supplied to the programmable counter 27, and the error signal output from the low-pass filter 30 is supplied to the VCO 76.

In this embodiment as well, many channels can be selected using a keyboard operation or a channel selection operation signal based on communication data. You can select the channel,
As in the first embodiment, if the model of the channel selection circuit section 71 is different, this can be handled by simply changing the formats of the channel data and status data.

Effects of the Invention As described above, the television channel selection method according to the present invention allows channel selection operations to be performed not only by keyboard operation but also by data communication, and the number of channels that can be selected is greater than that of the conventional method.
It also has the advantage that even if the model of television receiver WA is different, it can be easily handled by simply changing the format of the channel selection data.

[Brief explanation of drawings]

1 and 4 are block system diagrams of each embodiment of the system of the present invention, FIG. 2 is a diagram for explaining data output by a personal computer, and FIG. 3 is an illustration of processing executed by the personal computer. Example Flow Chee! -1-. 11.71...Tuning selection circuit section, 12...Monitor section, 1
3...Tuner section, 14.73...PLL section, 27
...Programmable counter, 40...Interface circuit, 41...Personal computer, 42
...Keyboard, 44...Modem, 50-63...
・Step, 83... Television receiver.

Claims (1)

[Claims] A television tuning method for a television receiver or up-down converter for cable television reception using a phase-locked loop, in which a tuning operation signal input by keyboard operation or data communication is converted into tuning data. A television channel selection method characterized in that the channel selection data is converted and the channel selection data is supplied to the phase-locked loop to vary the frequency division ratio of the oscillation signal of the phase-locked loop to perform channel selection.