JPH11261910A - Automatic setting device for output channel of rf converter of television signal receiver, video tuner and vtr - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically set an optimum output channel of an RF converter even in the case of a tuning system for a television signal adopting voltage control. SOLUTION: The television signal receiver is provided with a tuner and intermediate frequency amplifier circuit 4 that automatically selects a channel where a broadcast station signal is present from a received television signal by means of a voltage control system and with an RF converter 6 that converts a video signal and an audio signal of the selected channel where a broadcast station signal is present into an RF signal and outputs the RF signal based on the output of the circuit 4. Then a microcomputer 1 outputs sequentially a pulse width modulation PWM signal with a value corresponding to a voltage to select each channel to allow an automatic channel selector to sequentially select each channel where a broadcast station signal is present and to detect channels where broadcast station signals are not in existence over a prescribed channel number, obtains a value of a PWM signal corresponding to a voltage to select an intermediate channel and sets an output channel of the RF converter 6 based on the value of the obtained PWM signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an RF converter output channel automatic setting device for a television signal receiving device,
That is, in a video tuner device of a television signal receiving device such as a video tape recorder (hereinafter, referred to as a VTR), a device for converting a video signal and an audio signal of a channel being received into an RF signal and outputting the RF signal to a television set. More specifically, the present invention relates to a technique for automatically setting the output channel.

[0002]

2. Description of the Related Art When a video tape recorder (hereinafter, referred to as VTR) is connected to a TV set, a method of directly transmitting a video signal and an audio signal by bypassing a tuner of a TV set called a so-called line connection is used. There is a method in which the output of a VTR is temporarily converted into an RF signal of a certain channel of a television signal by an RF converter and sent to a tuner.

In the latter case, the tuner of the TV set must use a vacant channel because it needs to receive a television signal of another channel normally broadcast in the area. In Japan, NHK General uses either the first channel or the second channel depending on the area and does not use other broadcasting stations, so usually either the first channel or the second channel is used.
What is necessary is just to select it as the output converter of the RF converter, and there is no major problem whether the setting is made manually by the user or automatically by the device.

[0004]

However, in the case where products are exported overseas, it is necessary to set an available channel in each of many export destinations in advance, which leads to an increase in manufacturing costs. Become.

On the other hand, there are a frequency synthesizer method and a voltage control as a tuning method of a television signal. In the former, it is possible to automatically search for the presence or absence of a broadcasting station, set a receivable channel, and find an empty channel. It is possible. In this case, it is possible to set an optimum channel of the RF converter by calculating such that adjacent channels are not disturbed in the found empty channel.

However, in the latter case, it is possible to set a receivable channel, but it is necessary for the user to manually set an output channel of the RF converter by searching for an empty channel.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has an automatic RF converter output channel that can automatically set an optimal RF converter output channel even in a voltage-controlled television signal tuning system. It is an object of the present invention to provide a setting device, a video tuner device and a VTR having such a function.

[0008]

SUMMARY OF THE INVENTION The present invention provides an automatic channel selecting apparatus for automatically selecting a channel from a received television signal by a voltage control method, and an automatic channel selecting apparatus selected by the automatic channel selecting apparatus. An RF converter for converting a video signal and an audio signal of a station channel into an RF signal and outputting the RF signal; Means for successively selecting stationed channels by an automatic channel selection device by sequentially outputting PWM signals of values, means for detecting an area in which no channel is present over a predetermined number of channels, If an area where no channel is present is detected over a Characterized by comprising a means for setting the output channel of the RF converter based means for obtaining a value of the PWM signal, the value of the determined PWM signal to.

In the RF converter output channel automatic setting device of the television signal receiving device of the present invention, the PWM signal having a value corresponding to the voltage for selecting each channel is sequentially output to occupy the station. Channels are sequentially tuned by the automatic channel selection device, and when an area in which no channel is present is detected for a predetermined number of channels, the value of the PWM signal corresponding to the voltage for selecting an intermediate channel is determined. The output channel of the RF converter is automatically set based on the determined and determined value of the PWM signal.

[0010] The video tuner device according to the present invention comprises:
An automatic channel selection device that automatically selects a channel from a received television signal by a voltage control method, and converts a video signal and an audio signal of the channel selected by the automatic channel selection device into an RF signal. RF output
A video tuner device comprising a converter and a PWM having a value corresponding to a voltage for selecting each channel.
Means for sequentially outputting a signal to the automatic channel selecting device to sequentially tune a station, means for detecting an area in which no channel exists for a predetermined number of channels, and means for detecting an area where no channel exists for a predetermined number of channels. Means for determining a value of a PWM signal corresponding to a voltage for selecting an intermediate channel when an area where no channel exists is detected; and determining an output channel of the RF converter based on the determined value of the PWM signal. Setting means.

In such a video tuner of the present invention, the PWM signals having the values corresponding to the voltages for selecting the respective channels are sequentially output, so that the automatic channels are sequentially selected by the automatic channel selecting device. When a channel is tuned and an area in which no channel is present is detected over a predetermined number of channels, a value of a PWM signal corresponding to a voltage for selecting an intermediate channel is obtained, and a value of the obtained PWM signal is obtained. , The output channel of the RF converter is automatically set.

A VTR according to the present invention further comprises an automatic channel selecting device for automatically selecting a channel from a received television signal by a voltage control method, and a local channel selected by the automatic channel selecting device. And a RF converter for converting the video signal and the audio signal into an RF signal and outputting the RF signal, and sequentially outputting a PWM signal having a value corresponding to a voltage for selecting each channel by sequentially outputting the PWM signal. Means for causing the automatic channel selecting device to sequentially tune a station channel; means for detecting an area where no station channel exists for a predetermined number of channels; and means for detecting an area where no station channel exists for a predetermined number of channels. Means for determining the value of the PWM signal corresponding to the voltage for selecting the intermediate channel in the case, and the value of the determined PWM signal Based characterized by comprising a means for setting the output channel of the RF converter.

In such a VTR according to the present invention, a PWM signal having a value corresponding to a voltage for selecting each channel is sequentially output, so that an automatic channel selecting device sequentially selects a stationed channel. When a region in which no channel is present is detected over a predetermined number of channels, a value of a PWM signal corresponding to a voltage for selecting an intermediate channel is determined, and based on the value of the determined PWM signal. Thus, the output channel of the RF converter is automatically set.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings showing the embodiments. FIG. 1 is a block diagram showing a schematic configuration example of a video tuner device and a VTR provided with an RF converter output channel automatic setting device of a television signal receiving device according to the present invention.

In FIG. 1, reference numeral 30 denotes a video tuner device, which is provided with an RF converter output channel automatic setting device of the television signal receiving device of the present invention. The video tuner device 30 is built in the VTR 20.

A microcomputer (hereinafter referred to as a microcomputer) 1 controls a channel selection by operating an operation unit 2, displays a channel selection result on a display unit 3, and displays a VT.
Various controls are performed as the control center of R20. The operation unit 2 can use, for example, a keyboard, a remote control device, or the like.
It is possible to use a display tube (CRT display) of a television set connected via the RF converter 6 to be described later, or to use a dedicated display element such as an LCD.

A tuning instruction given from the operation unit 2 to the microcomputer 1 is given to the tuner and the intermediate frequency amplifier circuit (tuner + IF) 4 as tuning information. The television signal received by the antenna 5 is input to the tuner and the intermediate frequency amplifier circuit 4, and the channel is selected by a voltage control method. Specifically, the tuning voltage output from the microcomputer 1 is converted into a PWM (Pulse Width Modulation) value and input to the tuner and the intermediate frequency amplifying circuit 4, thereby controlling the tuning operation of the tuner and the intermediate frequency amplifying circuit 4. Then, the automatic setting of the output channel of the RF converter 6 which characterizes the present invention is performed.

The television signal selected by the tuner and the intermediate frequency amplifying circuit 4 is converted into an intermediate frequency (for example, a video signal is 58.75 MHz, an audio signal is 4.5 MHz), and is converted into a video signal processing circuit 7 and an audio signal processing circuit. 8 given. On the other hand, a desired wave signal selected by the microcomputer 1 and converted into an IF (intermediate frequency) signal by the microcomputer 1 in accordance with the operation of the operation unit 2 is fed back from the tuner and the intermediate frequency amplifier circuit 4 to the microcomputer 1 as a feedback signal. An AFTS curve signal, which is obtained by converting the frequency difference between the two into a DC voltage signal, is output.

The video signal processing circuit 7 and the audio signal processing circuit 8 process the video signal and the audio signal, respectively, and supply the processed signals to the RF converter 6 and the recording / reproducing unit 10.
The RF converter 6 converts the input video signal and audio signal into a frequency corresponding to the output channel set by the microcomputer 1, and outputs the frequency to the outside. When the external output of the RF converter 6 is input to the tuner of the television set, the signal can be received on the channel set by the microcomputer 1. RF converter 6 and microcomputer 1
Is connected by a serial bus, and the RF output channel determined by the microcomputer 1 is RF
The converter 6 is set.

Reference numeral 9 denotes a synchronization separation circuit.
The synchronization signal is separated from the video signal processed by the video signal processing circuit 7 and supplied to the microcomputer 1.

Next, FIGS. 2 to 4 are flowcharts showing the control procedure of the microcomputer 1 for the operation of the RF converter output channel automatic setting device of the television signal receiving device having the above-described configuration, and the UHF channels 21 to 69 are tuned. This will be described with reference to the schematic diagram of FIG. 5 showing the relationship with the voltage.

As shown in FIG. 5, the PWM value corresponding to the tuning voltage of the channel 30 is the comparison value 1
As P corresponding to the tuning voltage of channel 40
The WM value is set as the comparison value 2, the PWM value corresponding to the tuning voltage of the channel 50 is set as the comparison value 3, and the PWM value corresponding to the tuning voltage of the channel 60 is set as the comparison value 4.
It is assumed that the PWM value corresponding to the tuning voltage of the channel 69 is set in advance as the comparison value 5.

First, when the channel selection search by the microcomputer 1 is started (step S11), the microcomputer 1 performs a PWM output to the tuner and the intermediate frequency amplifier circuit 4 (step S11).
12). However, in this case, the microcomputer 1 first outputs the PWM value corresponding to the channel with the lowest tuning voltage (channel 21). Accordingly, since the station channel (broadcasting channel) is not the largest channel at first for the PWM output from the microcomputer 1 ("NO" in step S13), the microcomputer 1 uses the tuner and the intermediate frequency amplifier 4 Then, it is determined whether or not the PWM value currently output to is a value corresponding to the station channel (step S14).
If it is not a channel ("NO" in step S14),
The microcomputer 1 returns the processing to step S12, increases the PWM output by a predetermined value, and outputs it again to the tuner and the intermediate frequency amplifier circuit 4.

More specifically, as shown in FIG. 5, the microcomputer 1 corresponds to a tuning voltage of 21 channels.
The PWM value is output first, and thereafter, for example, the value of the PWM output is sequentially increased in ascending order according to the tuning voltage of each channel. As described above, when the microcomputer 1 sequentially increases the PWM output value from the minimum value and outputs the PWM output value, the PWM output value corresponding to the station channel is eventually obtained ("YES" in step S14). Here, the microcomputer 1 is the PWM output value (the PWM value corresponding to the currently owned channel) that is being output to the tuner and the intermediate frequency amplifier circuit 4 at that time.
Is smaller than or equal to a preset comparison value 1 (step S15).

As shown in FIG. 5, the comparison value 1 is 30
Since the PWM value corresponding to the tuning voltage of the channel has been set, the result of the determination in step S15 is "YES".
, That is, if a station channel is found in 30 channels or less, the process returns to step S12. However, if the result of the determination in step S15 is "NO",
That is, when no station channel is found in 30 channels or less, it is determined whether the PWM value of the station channel found immediately before is equal to or less than the comparison value 1 (step S16).

More specifically, while the result of the determination in step S15 is "YES", the microcomputer 1 sets the comparison value to 1, that is, the largest channel among the 30 or less channel if there are any. Can be found. If the result of the determination in step S15 is "NO", the microcomputer 1 has found a station channel out of more than 30 channels. Therefore, if the determination result in step S16 is "NO", a station channel is first found in a channel larger than 30 without finding a station channel in 30 or less channels corresponding to the comparison value 1. Means that. In this case, the microcomputer 1 sets the channel of the tuning voltage corresponding to the PWM value approximate to 1/2 of the comparison value 1 as the output channel of the RF converter 6 (step S31). Thereby, for example, 24 channels are set as output channels of the RF converter 6. In this case, since there is no station channel in the range of channels 21 to 30, there is no possibility that the output of the RF converter 6 will be disturbed by the station channel.

On the other hand, if the result of the determination in step S16 is "YES"
In other words, if the channel 1 exists on both sides of the channel 30 which is the tuning voltage corresponding to the comparison value 1, the microcomputer 1 sets the tuning voltage corresponding to the comparison value 1 to 30. A search is made for a local channel that is large and equal to or less than 40 channels, which is the tuning voltage corresponding to the comparison value 2 (step S
17). And. When a local channel is found in a channel larger than the tuning voltage channel 40 corresponding to the comparison value 2 (“NO” in step S17), the microcomputer 1 determines that the immediately preceding local channel is larger than the comparison value 1 and the comparison value It is determined whether it is within the range of 2 or less, that is, the range of more than 30 channels and 40 channels or less.
(Step S18).

If the result of the determination in step S18 is "NO", in other words, if a station channel is found in 41 or more channels, but no station channel is found in channels 31 to 40, The microcomputer 1 outputs the channel of the tuning voltage corresponding to a half of the “comparison value 1 + comparison value 2”, in other words, the PWM value corresponding to the PWM value approximate to the approximate center value between the comparison value 1 and the comparison value 2 from the RF converter 6. It is set as a channel (step S32).
Thereby, for example, 34 channels are set as output channels of the RF converter 6. In this case, since there is no station channel in the range of channels 31 to 40, there is no possibility that the output of the RF converter 6 will be disturbed by the station channel.

In the same manner, if a channel is found in 51 or more channels, but no channel is found in channels 41 to 50, the microcomputer 1 sets “comparison value 2 + comparison value 3” to 1 / 2,
In other words, the channel of the tuning voltage corresponding to the PWM value approximate to the value approximately at the center between the comparison value 2 and the comparison value 3 is set to RF.
It is set as an output channel of the converter 6 (steps S19, S20, S33). Thereby, for example, 44 channels are set as output channels of the RF converter 6. In this case, since there is no station channel in the range of channels 41 to 50, there is no possibility that the output of the RF converter 6 will be disturbed by the station channel.

Similarly, when a channel is found in 61 or more channels but no channel is found in channels 51 to 60, the microcomputer 1 determines 1/1/3 of "comparison value 3 + comparison value 4". 2. In other words, the approximate value of the middle value between the comparative value 3 and the comparative value 4
The channel of the tuning voltage corresponding to the PWM value is set as the output channel of the RF converter 6 (steps S21, S22, S34). Thereby, for example, 54 channels are set as output channels of the RF converter 6. In this case, since there is no station channel in the range of channels 51 to 60, there is no possibility that the output of the RF converter 6 will be disturbed by the station channel.

Finally, if no channel is found from channel 61 to channel 69, the microcomputer 1 determines that "comparison value 4 + comparison value 5" is 1/2, in other words, comparison value 4 and comparison value 5 The channel of the tuning voltage corresponding to the PWM value approximate to the value approximately at the center of the above is set as the output channel of the RF converter 6 (steps S23 and S23).
24, S35). Thereby, for example, 64 channels are set as output channels of the RF converter 6. In this case, since there is no station channel in the range of channels 61 to 69, there is no possibility that the output of the RF converter 6 will be disturbed by the station channel.

When the search is performed up to the maximum 69 channels ("YES" in step S13), if there is no station channel ("YE" in step S41).
In S "), there is no problem even if any channel is used as the output channel of the RF converter 6, so the microcomputer 1 sets a preset initial value as the output channel of the RF converter 6 (step S42). If a station channel exists ("NO" in step S41)
"), Which means that a vacant channel in which the output channel of the RF converter 6 can be set was not found, so that the microcomputer 1 terminates this processing without setting the output channel of the RF converter 6. In this case, it does not mean that the channel has no free space, so that the setting can be made by the user's manual operation.

[0033]

As described in detail above, according to the RF converter output channel automatic setting device of the television signal receiving device of the present invention, the television signal receiving device has an initially set RF converter output channel. Even in the case of overlapping with the station channel or in the case of being interfered by the adjacent channel, the optimal RF converter output channel is automatically set, so that there is no trouble for the user, and The manufacturer does not need to change the initial settings of the RF converter output channels of the various devices in which it is built in accordance with each shipping destination.

Further, according to the video tuner apparatus of the present invention, even when the initially set RF converter output channel overlaps with the station channel, or when it is disturbed by an adjacent channel, the automatic tuner can be used. Since the optimal RF converter output channel is set, there is no need to trouble the user, and the manufacturer does not need to change the initial setting of the RF converter output channel of the device according to each shipping destination .

Further, according to the VTR of the present invention, even when the initially set RF converter output channel overlaps with the station channel or when it is disturbed by an adjacent channel, it is automatically set. Since the optimum RF converter output channel is set, there is no need for user's trouble, and the manufacturer does not need to change the initial setting of the VTR RF converter output channel according to each shipping destination.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration example of an RF converter output channel automatic setting device of a television signal receiving device of the present invention and a VTR incorporating the device.

FIG. 2 is a flowchart showing a control procedure by a microcomputer for explaining an operation of an RF converter output channel automatic setting device of the television signal receiving device of the present invention.

FIG. 3 is a flowchart showing a control procedure by a microcomputer for explaining the operation of the RF converter output channel automatic setting device of the television signal receiving device of the present invention.

FIG. 4 is a flowchart showing a control procedure by a microcomputer for explaining the operation of the RF converter output channel automatic setting device of the television signal receiving device of the present invention.

FIG. 5 is a schematic diagram showing a relationship between UHF channels 21 to 69 and a tuning voltage.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Microcomputer (microcomputer) 4 Tuner and intermediate frequency amplifier circuit 6 RF converter 20 VTR 30 Video tuner device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoshi Amami 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd.

Claims (3)

[Claims] 1. An automatic channel selecting device for automatically selecting a channel from a received television signal by a voltage control method, and a video signal and an audio signal of the local channel selected by the automatic channel selecting device. And an RF converter that converts the signal into an RF signal and outputs the RF signal. In the RF converter output channel automatic setting device of the television signal receiving device, a PW of a value corresponding to a voltage for selecting each channel is provided.
Means for sequentially outputting station M by sequentially outputting M signals; means for detecting an area in which there are no station channels over a predetermined number of channels; Means for determining a value of a PWM signal corresponding to a voltage for selecting an intermediate channel when an area in which a local channel does not exist is detected; and determining the value of the RF converter based on the determined value of the PWM signal. Means for setting an output channel, the RF converter output channel automatic setting device for a television signal receiving device. 2. An automatic channel selecting device for automatically selecting a channel from a received television signal by a voltage control method, and a video signal and an audio signal of the channel selected by the automatic channel selecting device. And a RF converter for converting the signal into an RF signal and outputting the RF signal, a PW of a value corresponding to a voltage for selecting each channel.
Means for sequentially outputting station M by sequentially outputting M signals; means for detecting an area in which there are no station channels over a predetermined number of channels; Means for determining a value of a PWM signal corresponding to a voltage for selecting an intermediate channel when an area in which a local channel does not exist is detected; and determining the value of the RF converter based on the determined value of the PWM signal. Means for setting an output channel. 3. An automatic channel selecting device for automatically selecting a channel from a received television signal by a voltage control method, and a video signal and an audio signal of the local channel selected by the automatic channel selecting device. And a RF converter that converts the signal into an RF signal and outputs the signal.
Means for sequentially outputting station M by sequentially outputting M signals; means for detecting an area in which there are no station channels over a predetermined number of channels; Means for determining a value of a PWM signal corresponding to a voltage for selecting an intermediate channel when an area in which a local channel does not exist is detected; and determining the value of the RF converter based on the determined value of the PWM signal. VTR comprising means for setting an output channel.