KR100400738B1 - Method and apparatus for preventing strong electric field interference of TV - Google Patents

Abstract

An apparatus and method for preventing strong electric field interference of a TV, comprising: a wideband amplifier for amplifying an input RF signal into a wideband signal, a splitter for distributing the signal amplified by the wideband amplifier, and a signal distributed at the splitter First and second tuners which tune to channel signals according to the user's primary and secondary channel selections, and automatically adjust the gain of the internal amplifier according to the electric field magnitude of each tuned signal and output an automatic gain adjustment voltage; First and second intermediate wave detectors for detecting intermediate frequencies of the main and subchannels tuned by the first and second tuners and outputting the main channel and the subchannel CVBS signals, and outputted from the first intermediate wave detector. A noise detector for detecting a noise level of the main channel CVBS signal, and a main channel CVBS detected by the noise detector when the user changes the TV power on or channel It is configured to include a microcomputer for outputting a control signal for turning on / off the wideband amplifier by determining the electric field size of the RF signal currently input according to the noise level value of the signal and the automatic gain adjustment voltage level output from the first tuner. Screen noise can be removed by preventing interference between adjacent channel signals when inputting a system RF signal.

Description

TV's strong electric field interference prevention device and method {Method and apparatus for preventing strong electric field interference of TV}

The present invention relates to a TV, and more particularly, to a strong electric field interference prevention apparatus and method of a TV for preventing interference between two channel signals due to the input of a strong field RF signal when using a main channel and a subchannel tuner in a TV receiver.

Hereinafter, a strong electric field interference prevention apparatus of a TV according to the prior art will be described with reference to the accompanying drawings.

1 is a block diagram showing the configuration of a strong electric field interference prevention device of the TV according to the prior art.

As shown in FIG. 1, the TV's strong electric field interference prevention apparatus according to the prior art includes a wideband amplifier 10 for receiving an RF signal transmitted from a broadcasting station and amplifying the RF signal into a wideband signal and outputting the wideband signal. A main channel tuner for splitting the signal amplified and outputted by the multiplier and a channel input according to the user's main channel and subchannel selection, respectively, A first intermediate wave detector (30) and a first intermediate wave detector (50) for receiving the channel signal tuned by the main channel tuner (30), detecting an intermediate frequency of the input signal, and outputting a main channel CVBS signal ( 40) and a second intermediate wave detector 60 which receives the channel signal selected by the subchannel tuner 50, detects an intermediate frequency of the input signal, and outputs a subchannel CVBS signal.

Referring to the operation of the electric field interference prevention device of the TV according to the prior art configured as described above in detail.

First, the wideband amplification unit 10 receives an RF signal transmitted from a broadcasting station, amplifies a wideband signal and transmits the wideband signal to the divider 20, and the divider 20 amplifies the wideband amplification unit 10. Receives and distributes the received signal.

Subsequently, the main channel tuner 30 receives the signal distributed by the distributor 20 and selects a signal of the corresponding main channel according to the user's main channel selection from the divided input signal, and selects the corresponding channel signal. 1 is transmitted to the intermediate wave detector 40.

At this time, the first intermediate wave detector 40 detects the intermediate frequency of the signal tuned by the main channel tuner 30 and outputs the main channel CVBS.

In addition, the subchannel tuner 50 receives the signal distributed by the distributor 20 and selects the subchannel signal according to the user's subchannel selection from the divided input signal, and selects the corresponding channel signal. The second intermediate wave detector 60 transmits the data.

Subsequently, the second intermediate wave detector 60 detects an intermediate frequency of the signal tuned by the subchannel tuner 50 and outputs a subchannel CVBS signal.

The strong electric field interference preventing apparatus of the TV according to the related art described above has a problem in that screen noise is generated due to interference between adjacent channel signals due to amplification of a corresponding signal when the strong field RF signal is input to the wideband amplifier.

Accordingly, the present invention has been made to solve the above problems, to provide a strong electric field interference prevention apparatus and method of the TV to prevent the interference between adjacent channel signals by turning off the broadband amplification unit when a strong electric field RF signal input. The purpose is.

1 is a block diagram showing a strong electric field interference prevention device of the TV according to the prior art.

Figure 2 is a block diagram showing a strong electric field interference prevention device of the TV according to the present invention

3 is a flow chart showing a strong electric field interference prevention method of the TV according to the present invention.

* Explanation of symbols for main parts of the drawings

100: broadband amplifier 110: distributor

120: first tuner 130: first intermediate wave detector

140: noise detector 150: microcomputer

160: second tuner 170: second intermediate wave detector

180: key input unit

The strong electric field interference prevention device of the TV according to the present invention for achieving the above object is a broadband amplifier for amplifying the input RF signal into a wideband signal, a divider for distributing the signal amplified by the wideband amplification unit, Receive the divided signal and tune the channel signal according to the user's main and sub channel selection and output the automatic gain adjustment voltage by automatically adjusting the gain of the internal amplifier according to the electric field size of each tuned signal. First and second intermediate wave detectors for detecting intermediate frequencies of the main and subchannels tuned by the first and second tuners, and outputting the main and subchannel CVBS signals; Noise detection unit for detecting the noise level of the main channel CVBS signal output from the intermediate wave detection unit, and noise detection when the user changes the TV power on or channel The microcomputer outputs a control signal for turning on / off the wideband amplification unit by determining the electric field magnitude of the RF signal currently input according to the noise level value of the main channel CVBS signal detected from the PSA signal and the automatic gain adjustment voltage level output from the first tuner. It is configured to include its features.

The strong electric field interference prevention method of the TV according to the present invention for achieving the above object is provided with a wideband amplifier, a noise detector, the first and second tuners RF input according to the user's TV power 'on' or channel change In the strong electric field interference prevention method of the TV which prevents the interference between the channel signals of the first and second tuners due to the electric field size of the signal, whether the automatic fine adjustment operation is completed when the user changes the TV power on or channel. Receiving a noise level value of the main channel CVBS signal detected by the noise detector according to the present invention, and adjusting the automatic gain output from the first tuner when the noise level value of the input main channel CVBS signal is greater than or equal to the preset value-1. Determining whether the input voltage is less than or equal to a preset value; and if the input automatic gain adjustment voltage is less than or equal to the preset value, an electric field of the input RF signal. For the first and prevent interference between the channel signal of the second tuner from a group makin comprises the step of "off" portion broadband amplifier has its features.

Hereinafter, an apparatus and method for preventing strong electric field interference of a television according to the present invention will be described with reference to the accompanying drawings.

Figure 2 is a block diagram showing the configuration of a strong electric field interference prevention apparatus of the TV according to the present invention, Figure 3 is a flow chart showing a method of preventing the strong electric field interference of the TV according to the present invention.

As shown in FIG. 2, the apparatus for preventing strong electric field interference of a TV according to the present invention includes a wideband amplifier 100 for amplifying an input RF signal into a wideband signal, and a signal amplified by the wideband amplifier 100. A divider 110 for distributing a signal and a channel signal according to a user's primary and sub-channel selection, respectively receiving the signals distributed by the splitter 110, and at the same time, an internal amplifier according to the electric field size of each tuned signal. The first and second tuners 120 and 160 which automatically adjust the gain of (not shown) and output an automatic gain adjustment (AGC) voltage, and are tuned by the first and second tuners 120 and 160. First and second intermediate wave detectors 130 and 170 for detecting the intermediate frequencies of the main channel and the subchannels and outputting the main channel and subchannel CVBS signals, and outputting the first intermediate wave detector 130. Noise detector for detecting the noise level of the main channel CVBS signal 140, when the user changes the TV power 'on' or the channel, the noise level value of the main channel CVBS signal detected by the noise detector 140 and the automatic gain adjustment output from the first tuner 120 ( AGC) is configured to include a microcomputer 150 for outputting a control signal for turning on / off the wideband amplifier 100 by determining the electric field size of the currently input RF signal according to the voltage level.

Referring to the operation of the strong electric field interference control device of the TV according to the present invention configured as described above are as follows.

First, the wideband amplification unit 100 receives an RF signal transmitted from a broadcasting station, amplifies the wideband signal and transmits the wideband signal to the distributor 110.

Subsequently, the divider 110 receives the signal amplified by the wideband amplifier 100 and distributes it to the first and second tuners 120 and 160, respectively.

The wideband amplification unit 100 amplifies an RF signal transmitted from a broadcasting station into a wideband signal to compensate for insertion loss generated by the distributor 110.

Subsequently, the first tuner 120 receives the signal distributed by the distributor 110 and tunes the broadcast signal of the main channel selected by the user through the key input unit 180 from the corresponding input signal, Automatic gain controller voltage is generated by adjusting the gain of the internal amplifier (not shown) according to the electric field size.

Here, the first tuner 120 has an automatic gain adjustment (AGC) terminal of the RF signal, and the automatic gain adjustment voltage of the automatic gain adjustment terminal has an 'S' curve characteristic, so that the corresponding automatic gain in the electric field of a specific input signal is obtained. The adjustment voltage changes abruptly.

That is, it is biased to the maximum value below 50dB uV and is set to about half of the entire variable range at the standard input electric field (typically 55 to 65dB uV).

At this time, when a signal having an electric field higher than the standard input electric field is input, the automatic gain adjustment (AGC) voltage is rapidly decreased to maintain near the minimum value.

As a result, the magnitude of the electric field of the RF signal input from the change of the automatic gain adjustment (AGC) voltage of the first tuner 120 can be known.

In addition, not only the first tuner 120 but also the second tuner 160, an automatic gain adjustment (AGC) that automatically adjusts the gain of the internal amplifier (not shown) according to the electric field magnitude of the signal input from the divider 110. Terminal is included.

Subsequently, the second tuner 160 receives a signal distributed by the distributor 110 and selects a broadcast signal of a sub-channel selected by the user through the key input unit 180 from the input signal, and selects the selected sub-channel. Transmits the broadcast signal to the second intermediate wave detector 170.

In this case, the second intermediate wave detector 170 detects an intermediate frequency of the subchannel broadcast signal tuned by the second tuner 160 and outputs a subchannel CVBS signal.

The first intermediate wave detector 130 detects an intermediate frequency of the main channel broadcast signal tuned by the first tuner 120 and outputs a main channel CVBS signal.

Next, the noise detector 140 detects a noise level value of the main channel CVBS signal output from the first intermediate wave detector 130 and transmits the detected noise level value to the microcomputer 150.

Here, the noise level has a characteristic of increasing in proportion to the electric field size of the input RF signal.

In this case, when the user wants to change the TV power 'on' or the current viewing channel through the key input unit 180, the microcomputer 150 determines whether the automatic fine tuning is completed. The noise detector 140 receives a noise level value of the main channel CVBS signal detected by the noise detector 140.

That is, when the TV power 'on' or channel change signal is input through the key input unit 180, the microcomputer 150 automatically adjusts the gain of the noise detector 140 and the first tuner 120 (AGC). Determine whether the voltage is stable.

Subsequently, when the noise level detected by the noise detector 140 is less than or equal to the preset value-1, the microcomputer 150 has a good electric field size of the input RF signal, so that the first and second tuners 120 may have a good size. Since no interference occurs between the channel signals at 260, the wideband amplifier 100 outputs an 'off' control signal so that the broadband amplification unit 100 is not operated.

On the other hand, the microcomputer 150 receives an automatic gain adjustment (AGC) voltage of the first tuner 120 when the noise level detected by the noise detector 140 is greater than or equal to the preset value-1. When the automatic gain control (AGC) voltage is less than or equal to a preset value, since an electric field of the input RF signal is a strong electric field, interference occurs between channel signals of the first and second tuners 120 and 160, thereby causing screen noise. Occurs.

As a result, the microcomputer 150 outputs an 'off' control signal for stopping the operation of the broadband amplifier 100 to prevent interference between the channel signals of the first and second tuners 120 and 160. Remove the noise.

Here, when the predetermined noise generated at the output of the first intermediate wave detector 130 is mixed with the main channel CVBS signal and transmitted to the noise detector 140, the main channel CVBS signal detected by the noise detector 140 is detected. The noise level is increased by the noise generated at the output of the first intermediate wave detector 130, not due to the magnitude of the electric field of the input RF signal.

As a result, when the noise level value is greater than or equal to the preset value-1, the microcomputer 150 receives the automatic gain adjustment (AGC) voltage output from the first tuner 120 to the electric field magnitude of the RF signal. Judge.

At this time, since the AGC voltage of the first tuner 120 has a 'S' curve characteristic, the AGC voltage does not change with respect to a signal having an electric field other than a specific input electric field.

The strong electric field interference prevention method of the TV according to the present invention configured as described above will be described with reference to FIG. 3.

First, when the user changes the TV power 'on' or the channel through the key input unit 180 (S100), the microcomputer 150 determines whether the automatic fine tuning operation is completed (S110). ).

That is, when the TV power 'on' or the channel change signal is input through the key input unit 180, the microcomputer 150 automatically adjusts the gain of the noise detector 140 and the first tuner 120 (AGC). Determine whether the voltage is stable.

The product does not perform automatic fine adjustment (AFT) operation immediately in response to the electric field change of the input RF signal, and increases the stability of the product by performing the operation only when the TV power is 'on' or the channel is changed.

Subsequently, when the determination result (S110) and the automatic fine adjustment (AFT) operation is completed, the noise level value of the main channel CVBS signal detected by the noise detector 140 is received (S120).

In operation S130, it is determined whether the detected noise level value of the main channel CVBS signal is equal to or less than the preset value-1.

As a result of the determination (S130), if the detected noise level value of the main channel CVBS signal is less than or equal to the preset value-1, the electric field size of the input RF signal is very good and thus the first and second tuners 120 may be used. Since no interference occurs between the channel signals at 160, a control signal for stopping the broadband amplifier 100, that is, an 'off' signal is output (S170).

On the other hand, if the noise level value of the detected main channel CVBS signal is greater than or equal to the preset value-1, the determination result (S130), receives the automatic gain adjustment (AGC) voltage of the first tuner 120 ( S140).

Subsequently, it is determined whether the automatic gain adjustment (AGC) voltage is greater than or equal to a preset value (S150).

Subsequently, when the determination result (S150), the automatic gain adjustment (AGC) voltage is more than a predetermined value, the process returns to step (S160) for 'turning on' the broadband amplifier 100 to perform the corresponding step.

On the other hand, if the determination result (S150), the automatic gain adjustment (AGC) voltage is less than the predetermined value, since the electric field of the input RF signal is a strong electric field, the channel signals of the first and second tuners 120, 160 In order to prevent interference between the devices, the broadband amplification unit stops the operation (S170).

In this case, the AGC voltage has an 'S' curve characteristic, so if the electric field of the input RF signal is a strong electric field, the AGC voltage falls near the minimum value, thereby decreasing the electric field size of the currently input RF signal. You can judge.

As a result, the present invention determines the electric field magnitude of the RF signal input through the noise level value of the main channel CVBS signal detected by the noise detector and the automatic gain adjustment (AGC) voltage level of the first tuner to prevent interference between adjacent channels. Can be.

As described above, the apparatus and method for preventing strong electric field interference of a TV according to the present invention eliminates screen noise by preventing on / off interference between adjacent channel signals by turning on / off a broadband amplification unit according to the electric field size of an input RF signal. There is an effect that can improve the reliability.

Claims (4)

A wideband amplifier for amplifying the input RF signal into a wideband signal; A divider for distributing the signal amplified by the wideband amplifier; Receives the divided signal from the splitter and tunes the channel signal according to the user's main and sub channel selection, and automatically adjusts the gain of the internal amplifier according to the electric field size of each tuned signal to output the automatic gain adjustment voltage. First and second tuners; First and second intermediate wave detectors for detecting intermediate frequencies of the main channel and the subchannel tuned by the first and second tuners and outputting the main channel and the subchannel CVBS signals; A noise detector for detecting a noise level of the main channel CVBS signal output from the first intermediate wave detector; And, When the user changes the TV power 'on' or the channel, the electric field magnitude of the RF signal currently input according to the noise level value of the main channel CVBS signal detected by the noise detector and the automatic gain adjustment voltage level output from the first tuner. And a microcomputer for outputting a control signal for turning on / off the wideband amplifier by determining the strong electric field interference prevention device of the television. A wideband amplifier, noise detector, and first and second tuners are provided to prevent interference between the channel signals of the first and second tuners due to the electric field magnitude of the RF signal input according to the user's TV power 'on' or channel change. In TV's strong electric field interference prevention method, Receiving a noise level value of the main channel CVBS signal detected by the noise detector according to whether the automatic fine adjustment operation is completed when the user changes the TV power 'on' or the channel; If the noise level value of the input main channel CVBS signal is equal to or greater than 'preset value-1', determining whether or not to receive an automatic gain adjustment voltage output from the first tuner or less than the preset value; And, If the input automatic gain adjustment voltage is less than or equal to a predetermined value, 'off' the broadband amplification unit to prevent interference between channel signals of the first and second tuners due to the magnitude of the electric field of the input RF signal. The strong electric field interference prevention method of the TV, characterized in that made by. The method of claim 2, The determining of whether the automatic fine adjustment operation is completed is a step of determining whether the automatic gain adjustment voltages of the noise detector and the first tuner are stable. The method of claim 2, And if the noise level of the main channel CVBS signal detected by the noise detector is less than or equal to the preset value-1, turning off the wideband amplification unit.