KR20010000999A - Method and device of setting up comply with channel search speed and search level in a tv - Google Patents

Abstract

PURPOSE: An automatic channel setting device is provided to enable a user to freely set a desired condition by making an automatic channel set mode selected according to the strength of a signal at a standard search mode. CONSTITUTION: The automatic channel setting device comprises an analog to digital converter(10) which converts an AGC voltage of a tuner part(1) into a digital value so that an unwanted channel is stored to a memory at an automatic channel set mode. A microcomputer(20) has a port(Quick) for adjusting an AGC speed of the tuner part(1) and a port for recognizing an AGC level, and recognizes information of each channel according to the converted AGC voltage to provide a condition of selecting channel searching at a standard search mode. Switching elements are turned on/off according to a voltage level of a control signal that is set at the port(Quick) of the microcomputer(20) so as to adjust a wait period of time.

Description

TECHNICAL AND DEVICE OF SETTING UP COMPLY WITH CHANNEL SEARCH SPEED AND SEARCH LEVEL IN A TV}

The present invention relates to an apparatus and method for adjusting a channel search speed and level of a TV for searching by adjusting a search speed and a level when searching for a channel in a TV receiver.

In particular, the quick search mode and the normal search mode can be selected, and in the standard search mode, the user can freely set a desired condition by selecting an automatic channel setting mode according to the signal strength. The present invention relates to a channel search speed and a level adjusting device of a TV.

As shown in FIG. 1, a channel search apparatus used in a conventional TV may include an IF of a channel selected based on an AGC (Auto Gain Control) voltage adjusted according to a reception strength of a TV broadcast signal input to an antenna ANT. A tuner unit 1 for outputting an image frequency) signal,

A SAW filter unit 2 for filtering out a noise signal band other than the IF signal band output by the tuner unit 1;

A video signal detector (3) for detecting a composite video signal (CVBS) from the IF signal from which the noise signal band is filtered by the SAW filter unit (2) and detecting the presence of a synchronization signal;

In order to control each part of the system according to a key signal of a local key or a remote control, a tuner part 1 and an image signal detector 3 are connected to a data line (I ² C bus). A microcomputer (4) for controlling the channel search of the TV by determining the presence / absence of the composite video signal (CVBS) and the synchronization signal detected by the video signal detector (3);

In accordance with the control of the microcomputer (4) is composed of a memory unit 5 for storing the data of the channel in the channel setting mode of the TV.

The video signal detector 3 includes a first amplifier 3a for amplifying an IF signal whose noise signal band has been filtered by the SAW filter unit 2 and adjusting its output gain, and a predetermined local oscillation frequency ( a local oscillator 3b for outputting vco, a predetermined local oscillation frequency vco output from the local oscillator 3b, and an IF signal amplified while the output gain is adjusted by the first amplifier 3a. A mixing section 3c for outputting a video signal, a video output section 3d for outputting a composite video signal CVBS through the video signal output by the mixing section 3c, and the mixing section 3c. The sync signal detecting unit 3e detects the sync signal from the video signal output by the video signal and outputs it to the microcomputer 4, and the AGC of the tuner unit 1 detects the magnitude of the video signal output by the mixing unit 3c. A channel by the RF AGC unit 3f and the IF AGC unit 3g and the tuner unit 1 for automatically adjusting the gain of the IF signal. It includes an AFT detection unit (3h) for outputting the AFT (Auto Fine Tuning) detection signal to the microcomputer (4) to accurately select the station,

The speed of the gain automatically adjusted by the RF AGC section 3f and the IF AGC section 3g was adjusted by the capacitors C1, C2 and C3.

Hereinafter, unexplained reference numeral 3i is a buffer and R1 is a resistor.

3 is a flowchart showing a channel searching method implemented by the channel searching apparatus used in the conventional TV described above.

Setting an arbitrary channel to be searched, calculating a phase lock loop (PLL) of the channel set by the step, and outputting the PLL data calculated by the step to the tuner unit 1; When the PLL data is output to the tuner 1 by the above steps, the video signal detector 3 detects the video signal, determines whether there is a synchronization signal, and outputs the automatic search information of the TV channel to the microcomputer 4. Determining whether the image signal is recognized or not after a predetermined time (eg 300 ms), and if the image signal is recognized, the current PLL data is stored in the memory unit 5 and the image signal is detected. If is not recognized, the process proceeds to the step of completing the automatic search setting mode of the channel by setting the next channel and repeating the above steps to the last channel.

The operation of channel search of a conventional TV configured as described above will be described with reference to FIGS. 1 to 3.

First, when a user outputs an automatic search command of a channel to the microcomputer 4 by using a remote controller or a local key input, the microcomputer 4 automatically controls the channel through a data line (I ² C bus) according to the input key command signal. The search command is outputted to the tuner 1 and the video signal detector 3.

That is, the microcomputer 4 sets the first channel of the corresponding receiving system in the channel table stored in the memory unit 5 and performs the PLL operation of the corresponding channel according to the automatic search command of the input channel. The PLL data is output to the tuner unit 1.

At this time, when the PLL data is input to the tuner 1, the tuner 1 is the IF signal of the channel selected based on the AGC voltage adjusted according to the reception strength of the TV broadcast signal input to the antenna ANT. The SAW filter unit 2 outputs the signal to the SAW filter unit 2, and the SAW filter unit 2 filters the noise signal band from the band of the input IF signal and outputs it to the image signal detector 3.

In addition, the video signal detector 3 detects the composite video signal CVBS from the IF signal from which the noise signal band is filtered by the SAW filter unit 2, and determines whether there is a synchronization signal, and then automatically A waiting time of a predetermined time (for example, 300 ms) is given to output the search information to the microcomputer 4.

That is, the first amplifier 3a included in the image signal detector 3 amplifies an IF signal whose noise signal band is filtered by the SAW filter unit 2 and then adjusts its output gain to adjust the mixing unit 3c. Will be printed)

The mixing section 3c mixes a predetermined local oscillation frequency vco output from the local oscillation section 3b and an IF signal amplified while the output gain is adjusted by the first amplifier 3a to output an image signal. Will be.

At this time, the video signal by the mixing section 3c is outputted as the composite video signal CVBS by the video output section 3d, and the video signal output by the mixing section 3c is output from the synchronization detecting section 3e. After detecting the synchronization signal, the synchronization signal is output to the microcomputer 4.

In addition, the RF AGC unit 3f and the IF AGC unit 3g included in the image signal detector 3 detect the magnitude of the image signal output by the mixing unit 3c, and then tuner unit 1. The AGC and IF signal gains are automatically adjusted by the capacitors (C1, C2, C3) while adjusting their speed.

The AFT detection unit 3h outputs the AFT detection signal to the microcomputer 4 so that channel tuning by the tuner unit 1 is performed accurately.

Therefore, the microcomputer 4 determines whether the video signal is present or not according to the synchronization signal and the AFT detection signal input during the waiting time provided by the video signal detector 3.

When the microcomputer 4 determines that the video signal is recognized, the microcomputer 4 stores the current PLL data in a corresponding program, number, and address of the memory unit 5.

On the other hand, if the video signal is not recognized, the microcomputer 4 completes the automatic search setting mode of the channel by setting the next channel and then performing the above-described process until the last channel.

That is, the AFT detection unit 3h included in the image signal detection unit 3 outputs the AFT detection signal as shown in FIG. 2 to the microcomputer 4 so that channel tuning by the tuner unit 1 is performed accurately. ,

The microcomputer 4 ends the automatic search setting mode of the channel while storing the data value of the corresponding channel in the memory unit 5 according to the input AFT detection signal.

However, in the conventional channel search as described above, not only the channel search time is long (3 minutes to 5 minutes) but also in the case of advanced countries such as Europe, the distance between adjacent cities is relatively short and the effective field strength of the broadcast channel is good. There are inconveniences that a user must delete a channel searched for by unnecessary memory (eg, a broadcast channel having the same content transmitted from a broadcasting station or a relay station in a neighboring city) generated in the memory.

That is, in the conventional standard search mode, the inconvenience exists depending on the user's condition, and the search time is long in the market condition where the number of TV channels is only several, while the signal condition is good and the channel distribution of the cable TV is popularized. There is a problem that a large number of unnecessary channels are stored in market conditions.

Accordingly, the present invention allows to select the quick search mode (normal) and the normal search mode (normal search mode) in order to solve the conventional problems as described above in the standard search mode according to the automatic channel setting mode according to the signal strength By providing a TV channel search speed and level adjusting device and method for selecting and freely setting the conditions desired by the user, the user's selection range in the automatic channel search setting mode of the TV is expanded to provide convenience and the conventional standard. The purpose is to solve the inconvenience caused by the user condition that appeared as a problem in the search mode.

That is, the present invention allows the user to set in advance a condition to exclude unnecessary signals (eg, overlapping of adjacent same channels, channels of weak electric field signals, etc.) in the standard search mode. This is to solve the problem that a large number of unnecessary channels are stored while the channel can be quickly searched even in the market conditions in which good and cable TV channels are popular.

1 is a block circuit diagram showing a configuration of an automatic channel setting apparatus according to a channel search speed and level of a conventional TV.

Fig. 2 is a conventional AFT detection waveform diagram in an automatic channel setting mode.

3 is a flowchart illustrating an automatic channel setting method according to a channel search speed and a search level of a conventional TV.

Figure 4 is a block circuit diagram showing the configuration of the automatic channel setting apparatus according to the channel search speed and search level of the TV applied to the present invention.

5 is an AFT detection waveform diagram in a quick search mode in the present invention.

6 is a flowchart showing an automatic channel setting method according to a channel search speed and a search level of a TV applied to the present invention.

Figure 6a is a flow chart showing the progress of the automatic channel setting method according to the channel search speed in the fast search mode of the TV.

6B and 6C are flowcharts illustrating an automatic channel setting method according to channel search levels in a standard search mode of a TV.

Fig. 6B is a flowchart showing a search level L1 progress step of a condition (strong electric field) to be searched before execution of the automatic channel setting mode;

Fig. 6C is a flowchart showing a search level (L2) progression step of a condition (weak electric field) to execute a search before executing the automatic channel setting mode.

Hereinafter, an embodiment of the TV channel search speed and level adjustment device of the present invention will be described with reference to the accompanying drawings.

FIG. 4 is a block circuit diagram showing a channel search speed and a level adjusting device of a TV applied to the present invention. FIG. 5 is an AFT detection waveform diagram in a quick search mode according to the present invention.

As shown in FIG. 4, a tuner unit for outputting an image frequency (IF) signal of a channel selected based on an AGC (Auto Gain Control) voltage adjusted according to a reception strength of a TV broadcast signal input to an antenna ANT ( 1), an SAW filter unit 2 for filtering out a noise signal band other than the IF signal band output by the tuner unit 1, and an IF signal for which a noise signal band is filtered by the SAW filter unit 2; In a TV system comprising a video signal detector (3) for detecting a composite video signal (CVBS) at and a memory (5) for storing data of the channel in the channel setting mode of the TV,

In order to prevent unwanted channels (channels of weak electric fields in the standard search mode) from being stored in the memory unit 5 in the automatic channel setting mode, the AGC voltage value of the tuner unit 1 is converted to digital to the microcomputer 20. An A / D converter 10 for outputting;

Port for adjusting AGC speed of tuner section 1 ) And a port (ALI: AGC Level Ident) for recognizing the level, and the standard search mode by recognizing the information value of each channel according to the AGC voltage value which is converted into digital output from the A / D converter 10 and output. A microcomputer 20 for granting a selection condition for channel searching in the network;

Port of the microcomputer 20 ( Switching element Q11 which is turned on / off according to the level (high / low) of the control signal set in the control unit 1 and adjusts the AG AG speed of the tuner unit 1 and the IF AGC speed of the video signal and the waiting time for detecting the AFT. (Q12); It was configured to include more.

Hereinafter, reference numerals R2 to R7 denote resistors, C4 denotes capacitors, D1 denotes diodes, and L1 denotes coils. Like reference numerals denote like elements in FIG.

6 is a flowchart showing an automatic channel setting method according to a channel search speed and a search level of a TV implemented by an automatic channel setting apparatus according to a channel search speed and a search level of a TV according to an embodiment of the present invention.

That is, FIG. 6A is a flowchart illustrating a process of automatic channel setting method according to channel search speed in a fast search mode of a TV.

6B and 6C are flowcharts illustrating an automatic channel setting method according to a channel search level in a standard search mode of a TV.

FIG. 6B is a flowchart showing a progression of the search level L1 of the condition (strong electric field) to be searched before the automatic channel setting mode is executed, and FIG. 6C is a search of the condition (weak field) to be searched before the automatic channel setting mode is executed. This is a flowchart showing the level (L2) progression step.

As shown in FIG. 6, the progress of the automatic channel setting method according to the channel search speed and the search level of the TV is performed.

A search mode discrimination step of discriminating whether the automatic channel setting mode is the initial search mode or the standard search mode in an initial state at the time of execution;

As a result of the determination, if the fast search mode is performed, the AGC speed is increased according to the presence or absence of the AFT signal at the same time as the PLL operation of the corresponding channel. Performing a quick search mode for storing the PLL data of the corresponding channel and completing the automatic channel setting mode after shortening the degree);

As a result of the determination, in the standard search mode, the search level (L1), which is a signal condition of the strong electric field, is a condition to be searched before the automatic channel setting mode is executed so as to preclude unnecessary signal conditions (such as overlapping of the same channel or weak field signal channels). A search level setting step of presetting a search level L2 which is a signal condition of the weak electric field;

A first execution step of executing only the first automatic channel setting mode when only the search level L1, which is a signal condition of the strong electric field, is set in the signal condition to be searched by the above steps;

When the search level L1, L2, which is the signal condition of the strong electric field and the weak electric field, is set in the signal condition to be searched by the above steps, the first automatic channel setting mode in the signal condition of the first strong electric field is executed. A second execution step of sequentially executing a second automatic channel setting mode for a channel having a weaker signal condition again; It is going to be.

The quick search mode execution step may include: setting a channel to be searched and calculating a PLL of the set channel;

Outputting the PLL data calculated by the above step to the tuner unit 1;

In this step, when the PLL data is output to the tuner 1, the video signal detector 3 detects the video signal, determines whether there is a synchronization signal, and outputs the automatic search information of the TV channel to the microcomputer 20. Determining whether an image signal is recognized or not after an idle time of 15 ms;

As a result of the determination, if the video signal is recognized, the current PLL data is stored in the memory unit 5, and if the video signal is not recognized, the next channel is set, and the above channels are repeated until the last channel, and the channel according to the quick search is performed. Completing the automatic setting mode; Proceed with more

The first automatic channel setting mode according to the first execution step may include: performing a PLL operation of a channel while setting a channel to be searched and outputting the performed PLL data to the tuner unit 1;

In this step, when the PLL data is output to the tuner 1, the video signal detector 3 detects the video signal, determines whether there is a synchronization signal, and outputs the automatic search information of the TV channel to the microcomputer 20. Determining whether an image signal is recognized or not after an idle time of 300 ms;

As a result of the determination, when the video signal is recognized, the search level L1 which is a strong electric field signal condition of the AGC set before the automatic automatic channel setting mode is executed by the AGC level value A read by the microcomputer 20 through the A / D converter 10. Comparing with);

If the AGC level value A read by the microcomputer 20 is less than or equal to the search level L1, which is a strong electric field signal condition of the AGC set before executing the automatic channel setting mode, the corresponding channel is stored. Repeating the standard search mode after setting; It is going to be.

In addition, the second automatic channel setting mode according to the second execution step is a search level L2 which is a weaker electric field signal condition again after the first automatic channel setting mode in the first strong electric field signal condition is executed. Determining whether a) is set;

If the search level L2, which is a signal condition of the weak electric field, is set, outputting the PLL data to the tuner 1 after performing the PLL operation of the channel while setting the channel to be searched;

In this step, when the PLL data is output to the tuner 1, the video signal detector 3 detects the video signal, determines whether there is a synchronization signal, and outputs the automatic search information of the TV channel to the microcomputer 20. Determining whether an image signal is recognized or not after an idle time of 300 ms;

As a result of the determination, when the video signal is recognized, the AGC level value A read by the microcomputer 20 through the A / D converter 10 is a search level L1 which is a strong electric field signal condition of the AGC set before executing the automatic channel setting mode. Comparing with the search level L2 which is a weak electric field signal condition;

As a result of the comparison, when the AGC level value A read from the microcomputer 20 is located between the strong and weak search levels L1 and L2 (L1≤A≤L2), the corresponding channel is stored, or the next channel is stored. Repeating the standard search mode after setting; It is going to be.

The operation of the automatic channel setting apparatus and method according to the channel search speed and the search level of the TV, which is an embodiment of the present invention configured as described above, will be described with reference to FIGS. 4 to 6.

First, when the automatic channel setting mode is executed, the microcomputer 20 determines whether the automatic channel setting mode is the quick search mode or the standard search mode in the initial state at the time of execution.

Thereafter, if the determination result is the fast search mode, the microcomputer 20 sets the initial channel to be searched and then tunes the PLL operation data of the set channel through the data line I ² C bus. Will output

The tuner unit 1 outputs the IF signal of the selected channel to the SAW filter unit 2 based on the AGC voltage adjusted according to the reception strength of the TV broadcast signal input to the antenna ANT, thereby providing the SAW. The filter unit 2 filters the noise signal band from the band of the input IF signal and outputs the noise signal band to the image signal detector 3.

At this time, the video signal detector 3 detects the composite video signal CVBS from the IF signal from which the noise signal band is filtered by the SAW filter unit 2, and determines whether there is a synchronization signal, and then automatically The search information is output to the microcomputer 20.

That is, the first amplifier 3a included in the image signal detector 3 amplifies an IF signal whose noise signal band is filtered by the SAW filter unit 2 and then adjusts its output gain to adjust the mixing unit 3c. The mixing unit 3c mixes the predetermined local oscillation frequency vco output from the local oscillator 3b and the IF signal amplified while the output gain is adjusted by the first amplifier 3a. The video signal is output.

In this case, the video signal mixed by the mixing unit 3c is output as the composite video signal CVBS through the image output unit 3d, and the image output by the mixing unit 3c in the synchronous detection unit 3e. After detecting the synchronization signal from the signal and outputs it to the microcomputer 20.

Then, the RF AGC unit 3f and the IF AGC unit 3g included in the image signal detector 3 detect the magnitude of the image signal output by the mixing unit 3c and then tuner unit 1. The gains of AGC and IF signals are automatically adjusted, and the AFT detection section 3h detects the AFT signal so that channel tuning by the tuner section 1 is performed accurately.

Here, the microcomputer 20 has a port for adjusting the AGC speed of the tuner unit 1 ( ), The port ( Is set to the low state when the TV is in the fast search mode and to the high state when the TV is in the standard search mode.

Therefore, when the TV selects the fast search mode, the port of the microcomputer 20 ( ) Becomes low, and the switching elements Q1 and Q2 are turned off.

At this time, the RF AGC of the tuner unit 1 and the capacitor for adjusting the IF AGC speed of the image signal according to the off operation of the switching elements Q1 and Q2 are composed of only capacitors C1 and C3 having small capacitance values.

The AGC speed of the tuner unit 1 is made faster by the condensers C1 and C3 configured as described above. And shortening the waiting time (eg, 15 ms) for detecting the AFT signal, and determining only the presence or absence of the AFT signal as shown in FIG. 5 and storing the PLL data of the corresponding channel in the memory unit 5. Automatic channel setting mode is executed.

On the other hand, when the standard search mode is selected, the microcomputer 20 presets the signal condition to be searched before executing the automatic channel setting mode so as to preclude unnecessary signal conditions (such as overlapping or weak field signal channels of the same channel) in advance. Will be set.

That is, the microcomputer 20 has a port ALI for recognizing the AGC voltage level of the tuner unit 1,

The A / D converter 10 converts and outputs a digital signal to the port ALI so that a channel that is not desired by the user (a weak electric field channel in the standard search mode) is not stored in the memory unit 5 in the automatic channel setting mode. The AGC voltage value of the tuner section 1 is input.

Accordingly, the microcomputer 20 recognizes the information value of each channel according to the AGC voltage value input to the port ALI, and compares the desired signal level with the signal level set by the user before executing the automatic channel setting mode in the standard search mode. Only the signal components greater than the input signal strength can be stored in the automatic channel setting mode,

By finding a channel with sufficient signal strength and then performing it once again for the lower signal components, the channel search selection conditions in the automatic channel setting mode are given by the user.

This will be described in more detail as follows.

First, the search level (L1), which is the signal condition of the strong electric field, and the signal of the weak electric field as a condition to be searched before executing the automatic channel setting mode so as to preclude unnecessary signal conditions (eg, overlapping of adjacent same channels or weak field signal channels). The search level L2, which is a condition, is set in advance.

At this time, when only the search level L1 which is the signal condition of the strong electric field is set in the signal condition to be searched, the microcomputer 20 executes only the first automatic channel setting mode according to the search level L1 of the set strong electric field. Let's

If the search conditions L1 and L2 which are the signal conditions of the strong electric field are set in the signal condition to be searched, the microcomputer 20 executes the first automatic channel setting mode in the set strong electric field and then again. Secondary automatic channel setting mode is executed sequentially for the channel with weaker signal condition.

Here, the operation description when setting only the search level L1 as the signal condition of the strong electric field is included in the operation description when setting both the search levels L1 and L2 as the signal condition of the strong electric field and the weak electric field. Only this will be explained.

First, when the standard search mode is selected and the search level (L1, L2), which is a signal condition to search, is set before executing the automatic channel setting mode, the PLL operation of the corresponding channel is performed while setting the channel to search. Outputted PLL data to the tuner section 1.

When the PLL data is output to the tuner 1, the video signal detector 3 detects the video signal CVBS, determines whether there is a synchronization signal, and sends the channel automatic search information to the microcomputer 20. To give a certain time (eg 300ms) waiting time to output the bar,

The microcomputer 20 determines whether the video signal is recognized or not while recognizing the channel auto discovery information according to a predetermined time (for example, 300 ms).

At this time, when the video signal is recognized, the microcomputer 20 searches for the AGC level value A read through the A / D converter 10, which is a strong electric field signal condition of the AGC set before executing the automatic channel setting mode (L1). ).

If the AGC level value A read by the microcomputer 20 is less than or equal to the search level L1 which is the strong electric field signal condition of the AGC set before the automatic channel setting mode is executed, the corresponding channel is stored. After setting the next channel, the standard search mode is repeated.

Here, the AGC voltage output of the tuner section 1 shows a low voltage value in the case of a strong electric field with a good signal condition, and a high voltage value in the opposite case.

On the other hand, if the search level (L2), which is the signal condition of the weaker electric field, is set again after the first automatic channel setting mode in the first strong electric field signal condition is executed as described above,

The PLL operation of the channel is performed while setting the channel to be searched, and the PLL data is outputted to the tuner 1.

Thereafter, when the PLL data is output to the tuner 1, the video signal detector 3 detects the video signal CVBS, determines whether there is a synchronization signal, and sends the channel automatic search information to the microcomputer 20. Give a waiting time of a certain time (for example 300ms) to output

The microcomputer 20 determines whether the video signal is recognized or not while recognizing the channel auto discovery information according to a predetermined time (for example, 300 ms).

At this time, when the video signal is recognized, the microcomputer 20 searches for the level L1, which is the AGC level value A read through the A / D converter 10, which is a strong electric field signal condition of the AGC set before the automatic channel setting mode is executed. ) And the search level (L2) which is a weak electric field signal condition.

If the AGC level value A read from the microcomputer 20 is located between the strong and weak search fields L1 and L2 (L1≤A≤L2), the corresponding channel is stored. By repeating the standard search mode after setting the next channel, the user can cope with the selection condition of the channel search in the automatic channel setting mode.

As described above, the present invention allows the user to select a quick search mode and a standard search mode, and then, in the standard search mode, the user can freely set a desired condition by selecting an automatic channel setting mode according to the signal strength. The user can preset conditions to exclude unnecessary signals (duplication of adjacent same channel, weak electric field signal channels, etc.) in advance, and the market conditions or signal conditions of only a few TV channels are good, and the spread of cable TV is common. In the market conditions, it is possible to quickly search for channels and solve the problem of storing a large number of unnecessary channels.

Claims (5)

In the TV system for storing the data of the channel in the channel setting mode while outputting the IF signal of the selected channel based on the AGC voltage adjusted according to the reception strength of the TV broadcast signal input to the antenna, An A / D converter which converts the AGC voltage value of the tuner unit into digital and outputs it to the microcomputer so that a channel which is not desired by the user is not stored in the memory unit in the automatic channel setting mode; It has a port for adjusting the AGC speed of the tuner and a port for recognizing its level, and the channel is searched in the standard search mode by recognizing the information value of each channel according to the AGC voltage value converted and output from the A / D converter to digital. A microcomputer for granting a selection condition of a; A switching element configured to be turned on / off according to a level of a control signal set in the AGC speed adjusting port of the microcomputer to adjust the IF AGC speed of the tuner unit and the IF AGC speed of the image signal and a waiting time for detecting the AFT; Automatic channel setting device according to the channel search speed and search level of the TV, characterized in that the configuration further comprising. Reducing the search speed by speeding up the AGC at the same time as performing the PLL operation of the corresponding channel to be searched in the automatic channel setting mode; Detecting only the presence or absence of an AFT signal while shortening a waiting time for detecting the AFT signal according to the search speed shortened by the above; A quick search mode execution step of completing an automatic setting mode of a channel according to a quick search while storing PLL data of a corresponding channel according to whether the AFT signal is detected by the above step; Automatic channel setting method according to the channel search speed of the TV characterized in that proceeds to. Search to set search level which is signal condition of strong electric field and search level which is signal condition of weak electric field. A level setting step; A first execution step of executing only a first automatic channel setting mode when only a search level that is a signal condition of a strong electric field is set in the signal condition to be searched by the above steps; When the search level, which is the signal condition of the strong electric field and the weak electric field, is set in the signal condition to be searched by the above steps, the weaker signal is executed after executing the first automatic channel setting mode in the signal condition of the first strong electric field. A second execution step of sequentially executing a second automatic channel setting mode for a channel of a condition; Automatic channel setting method according to the channel search level of the TV, characterized in that proceeds to. The method of claim 3, wherein the first automatic channel setting mode according to the first execution step comprises: outputting data by PLL operation of a channel to be searched and determining whether or not the video signal is recognized; Comparing the AGC level read by the microcomputer with the search level which is a strong electric field signal condition of the AGC set before executing the automatic automatic channel setting mode when the image signal is recognized as a result of the determination; If the AGC level value read from the microcomputer is less than or equal to the search level which is the AGC signal condition set before the automatic channel setting mode is executed, the corresponding channel is memorized, or if the next channel is set, the search mode is repeatedly performed. step; Automatic channel setting method according to the channel search level of the TV, characterized in that further comprising. 4. The method of claim 3, wherein the second automatic channel setting mode according to the second execution step is a weaker electric field signal condition again after the first automatic channel setting mode in the first strong electric field signal condition is executed. Determining whether a level is set; Determining whether the image signal is recognized or not by outputting data by PLL operation of a channel to be searched if the search level, which is a signal condition of the weak electric field, is determined as the result of the determination; Comparing the AGC level read by the microcomputer with the search level, which is a strong electric field signal condition of the AGC set before the automatic channel setting mode, and the search level, which is a weak electric field signal condition, when the image signal is recognized as a result of the determination; Storing the corresponding channel when the AGC level value read by the microcomputer is located between the strong field and the weak field of the weak field, or repeating the search mode after setting the next channel; Automatic channel setting method according to the channel search level of the TV, characterized in that further comprising.