KR20060097914A - A method for shortening scan time in video display apparatus for use in both analog and digital broadcasting - Google Patents

Abstract

The present invention relates to a method for shortening a channel scan time of an analog / digital broadcast video display device. After scanning a channel for analog broadcast in an analog / digital broadcast video display device, a channel in which an analog broadcast signal exists is skipped. The channel scan time is scanned, and the channel scan time is shortened by scanning the channel as a background task whether the digital broadcast signal exists in the skipped channel.

According to the present invention, a channel scan of an analog broadcast is started, whether or not an analog broadcast signal exists among the broadcast signals received by the antenna is stored, and the channel number of the analog broadcast signal is stored, and the channel scan of the digital broadcast is performed. Start by determining whether the channel to be scanned currently is the same as the channel of analog broadcasting stored in the memory unit, and then determine whether there is a digital broadcasting signal among the broadcasting signals received by the antenna to determine the number of the channel where the digital broadcasting signal exists. Save it. As a result, since the digital broadcast signal may exist in the skipped channel, it is determined whether the digital broadcast signal exists for the analog broadcast channel stored in the memory unit as a background task, thereby reducing the tedious time that the viewer waits for scanning the channel. Can be.

Analog Broadcast, Digital Broadcast, Channel Scan

Description

A method for shortening scan time in video display apparatus for use in both analog and digital broadcasting}

1 is a flowchart illustrating a method of scanning a channel in a conventional analog / digital broadcast image display apparatus.

2 is a block diagram illustrating a system to which a method for shortening a channel scan time of an image display apparatus for analog / digital broadcasting according to the present invention is applied.

Figure 3a is a flow chart showing the main operation in the method for reducing the channel scan time of the analog and digital video display device of the present invention.

3B is a flowchart illustrating a background operation in a method of shortening a channel scan time of an analog / digital broadcast image display device according to the present invention;

The present invention relates to a method for shortening a channel scan time of an analog / digital broadcast video display device. After scanning a channel for analog broadcast in an analog / digital broadcast video display device, a channel in which an analog broadcast signal exists is skipped. Scan channels in digital broadcast to reduce channel scan time. The present invention also relates to a method for shortening a channel scan time of an analog / digital broadcast image display device that scans a digital broadcast signal by scanning a digital broadcast channel only for a channel found in a channel scan of an analog broadcast as a background task for a skipped channel. will be.

In analog broadcasting, a broadcasting signal is converted into an analog signal and transmitted through a satellite or terrestrial channel. In the digital broadcasting, the broadcasting signal is transmitted into a satellite or terrestrial channel using a digital code as used in a computer. The digital broadcasting and analog broadcasting have various differences due to the characteristics of digital and analog.

Digital broadcasting reduces the deterioration factors such as ghost (dual afterimage) and color bleeding that occur while passing through air like analog broadcasting, and thus it is possible to freely transmit a broadcast signal without losing information. In addition, the channels currently allocated to analog broadcasting are microwave and microwave channel bands, and the frequency band of one channel is 6 MHz, which limits the number of channels to 82. Actually, only 47 channels are used to prevent interference with adjacent signals. Do not. In contrast, digital broadcasting can provide a variety of programs because one HD (High Definition) program or four Standard Definition (SD) programs can be implemented in a 6 MHz band. In the current analog broadcasting, the video display device has only a unidirectional function as a reception medium, but in the case of digital broadcasting, it may implement a bidirectional function.

Due to the limitations of analog broadcasting and the advantages of digital broadcasting, viewers have recently used an analog / digital tuner or equipped with an analog tuner and a digital tuner at the same time to receive both analog and digital broadcasts to display images on the screen. There are many video display devices for both analog and digital broadcasting that can be displayed. In recent years, the base station transmitting the broadcast signal is also a trend to transmit not only analog broadcasting but also digital broadcasting.

Recently, the analog / digital video display device scans a channel by receiving a broadcast transmitted by a base station through an antenna for the user's convenience, and then searches and stores a channel containing a program among the scanned broadcast channels, and stores the list. To display to the user.

However, in the conventional method of scanning a channel, a user first determines whether an analog broadcast signal exists for all channels of a broadcast signal transmitted by a base station and received through an antenna, and then determines whether a digital broadcast signal exists. The time to wait for the scan to finish was boring. The analog broadcast signal refers to a broadcast signal carrying an analog broadcast program among broadcast signals received through an antenna, and the digital broadcast signal refers to a broadcast signal carrying a digital broadcast program among broadcast signals received through an antenna. For example, analog broadcasting determines whether an analog broadcasting signal is included in a broadcasting signal received through an antenna, and thus the channel searching time is very short. However, in the case of digital broadcasting, a broadcasting signal received by an antenna is processed and then input to a TPS decoder. The TPS decoder analyzes whether the signal modulation method is correct by inputting several parameters in sequence until the modulation method of the received signal is correctly analyzed, and the received signal from the antenna as the output signal for the analysis result. Whether or not the broadcast signal is a digital broadcast signal is determined. However, in the case of terrestrial broadcasting in Europe, the transmission method is different depending on the region such as 23 kinds of signal transmission methods, so that the TPS decoder has to apply a large number of parameters in order, so the channel search time is long. Therefore, after determining whether or not an analog broadcast signal exists for all channels of the received broadcast signal, it takes considerable time to determine whether a digital broadcast signal exists. In case of DCR (Digital Cable Ready) model, there are 69 NT channels, 69 DTV channels, 135 cable broadcasting channels and 135 digital cable broadcasting channels, so it takes 5 to 8 minutes to scan all channels. .

This conventional technique will be described with reference to FIG. 1.

1 is a flowchart illustrating a method of scanning a channel in a conventional analog / digital broadcast image display apparatus. As shown in step S100, scanning of a channel of an analog broadcast is started. That is, the analog / digital broadcast image display apparatus receives a broadcast signal transmitted from a base station from an antenna and starts scanning from the lowest channel to search for a channel including the analog broadcast signal.

In the next step S102, it is determined whether or not an analog broadcast signal exists in the channel currently being scanned. For example, since the analog broadcast signal includes a horizontal sync signal and a vertical sync signal, it is determined whether a sync signal is detected for the channel currently being scanned to determine whether an analog broadcast signal exists in the channel.

If the analog broadcast signal is present in the channel being scanned as a result of the step S102, the channel number is stored in the memory unit in step S106.

However, if the analog broadcast signal does not exist in the channel currently being scanned as a result of the determination in step S102, it is necessary to search whether the analog broadcast signal exists for the next channel, so that the channel is increased by 1 in step S104. To continue scanning the channel.

After storing the number of the channel in which the analog broadcast signal exists in the memory unit 230 in the step (S106), it is determined whether the channel of the analog broadcast is terminated in the next step (S108). In other words, since analog broadcasting uses microwave and microwave channel bands, the allocated channel is limited. Therefore, it is determined whether or not the presence of the analog broadcast signal is searched for the highest channel allocated to the analog broadcast.

If the channel of the analog broadcast is not terminated as a result of the determination in step S108, the channel is increased by 1 to continue scanning the channel in order to determine whether there is an analog broadcast signal for the next channel in step S104. do.

However, if the analog broadcast channel is terminated as a result of the determination in step S108, the next step (S110) starts scanning the digital broadcast channel. That is, after receiving a broadcast signal transmitted by a base station through an antenna, a scan is started from the lowest channel to search for a channel including a digital broadcast signal.

In the next step S112, whether the digital broadcast signal exists in the channel currently being scanned is searched. For example, in digital broadcasting, the TPS decoder inputs a plurality of parameters and analyzes whether the modulation method of the signal is correct to determine whether the digital broadcasting signal exists in the channel currently being scanned.

If the digital broadcast signal exists in the channel being scanned as a result of the determination in step S112, the channel number is stored in the memory unit in step S116.

However, if the digital broadcast signal does not exist in the channel being scanned as a result of the determination in step S112, the channel is increased by 1 to search whether the digital broadcast signal exists for the next channel in step S114. To continue scanning the channel.

After storing the number of the channel in which the digital broadcast signal exists in step S116, it is determined whether the digital broadcast channel is terminated in the next step S118. In other words, since digital broadcasting has a limited number of assigned channels, it is determined whether the digital broadcasting signal has been searched for the highest channel among digital broadcasting channels.

If the channel of the digital broadcast is not terminated as a result of the determination in step S118, the channel is increased by 1 in step S114 to continue scanning the channel.

However, if the channel of the analog broadcast is terminated as a result of the determination in step S118, scanning of the channel is terminated.

In the conventional analog / digital video display device, a method for scanning a channel is performed by scanning all channels of analog broadcast to search whether or not an analog broadcast signal exists for a broadcast signal received through an antenna, and then In order to determine whether a broadcast signal is present, all channels of digital broadcasting are scanned. In the case of analog broadcast channel scan, much time is not required, but in the case of digital broadcast channel scan, much time is required, so the user feels boring time to scan the channel.

Therefore, an object of the present invention is to skip the channel in which the analog broadcast signal exists after scanning the channel of the analog broadcast, and to search for the existence of the digital broadcast signal by scanning the channel of the digital broadcast, and only for the skipped channel. The present invention relates to a method for shortening a channel scan time of an analog / digital broadcast image display apparatus by scanning a background job to scan whether a channel exists or not, and thereby reducing a time for scanning a channel.

The method for shortening the channel scan time of the analog / digital broadcast video display device having the above object starts the channel scan of the analog broadcast, and if the analog broadcast signal exists in the channel being scanned, stores the channel number. It is determined whether the analog broadcast channel is terminated. When the analog broadcast channel is terminated, the channel scan of the digital broadcast is started. If the channel scanned by the digital broadcast is not the same as the channel of the analog broadcast stored in the memory unit, it is determined whether a digital broadcast signal exists in the corresponding channel. If a digital broadcast signal exists in a channel, the number of the corresponding channel is stored and it is determined whether the digital broadcast channel is terminated.

If the analog broadcast signal does not exist in the channel currently being scanned, the method further comprises increasing the channel by one.

 If the analog broadcast channel is not terminated, further comprising increasing the channel by one.

The method may further include determining whether the digital broadcast channel is terminated when the channel of the analog broadcast stored in the memory unit and the current scanning channel are the same.

If the digital broadcast signal does not exist in the channel currently being scanned, the method further comprises increasing the channel by one.

If the digital broadcast channel is not terminated, the method further comprises increasing the channel by one.

In order to determine whether a digital broadcast signal exists in a channel of an analog broadcast stored in the memory unit, it is determined whether a channel having an analog broadcast signal is stored in the memory unit as a background job, and if so, the digital broadcast Starting the background task of the channel scan, storing the channel number if the digital broadcasting signal exists in the channel being scanned, and then determining whether all channels of the analog broadcasting stored in the memory unit have been scanned. It is characterized by.

If the digital broadcasting signal does not exist in the channel currently being scanned in the background task, the method further includes increasing the channel to the uppermost channel closest to the channel currently being scanned among the channels of the analog broadcasting stored in the memory unit.

The method may further include increasing the channel to the uppermost channel closest to the channel currently being scanned among the channels of the analog broadcast stored in the memory unit when not scanning all the channels of the analog broadcast stored in the memory unit.

Hereinafter, a method of reducing channel scan time of an analog / digital broadcast image display device according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram illustrating a system to which a method for shortening a channel scan time of an image display apparatus for analog / digital broadcasting according to the present invention is applied.

As shown in this figure, a channel number for a specific frequency range is set internally so that the analog tuner unit 200 tunes a specific channel during an analog channel scan, and the first and second digital tuner units during a digital channel scan. The controller 220 controls to tune to a specific channel at 240 and 260, and stores the corresponding channel in the memory unit 230 if an analog broadcast signal or a digital broadcast signal exists in the specific channel, and broadcast signal through an antenna. An analog tuner unit 200 that receives the input and tunes the frequency of a specific channel under the control of the controller 220, and outputs an intermediate wave to the synchronization signal detector 210, and an intermediate received from the analog tuner unit 200. When a synchronization signal is detected in a wave, the synchronization signal detection unit 210 inputs the control signal to the control unit, and receives a broadcast signal through an antenna to control the main channel of the specific channel under the control of the control unit 220. A first digital tuner unit 240 for tuning the numbers and outputting an I signal and a Q signal, and a first signal for analyzing whether the modulation scheme is correct by receiving a signal output from the first digital tuner unit 240; TPS decoder 250, used for the background task of digital channel scan, receives a broadcast signal through an antenna, tunes the frequency of a specific channel under the control of the controller 220, and then I and Q signals for the broadcast signal of the specific channel. A second digital tuner unit 260 for outputting a signal, a second TPS decoder 270 for analyzing whether a modulation scheme is correct by receiving a signal output from the second digital tuner unit 260, and an analog broadcast signal. And a memory unit 230 for storing the number of the channel in which the digital broadcast signal exists.

The control unit 220 is a channel number for each frequency band is set in advance, the analog tuner unit 200, the first digital tuner unit 240 and the second digital tuner unit 260 tunes a specific channel in the channel scan To control it. For example, in the united states National Television Systems Committee (NTSC), channel 2 uses a frequency band of 54 to 60 MHz and channel 3 uses a frequency band of 60 to 66 MHz. The controller may be configured to scan a specific channel because a table of channels corresponding to the frequency band is preset therein, and the analog tuner unit 200, the first digital tuner unit 240, and the second digital tuner unit 260 may be used. Controls the frequency of a specific channel to be tuned in.

In addition, when the controller 220 receives the sync signal from the sync signal detector 210, the controller 220 stores the number of the corresponding channel of the broadcast signal from which the sync signal is detected in the memory 230.

In addition, the controller 220 receives a signal from the first and second TPS decoders 250 and 270 as to whether or not the modulation method is correct for the broadcast signal of a specific channel, and receives the number of the corresponding channel determined that the modulation method is correct. Store it in the memory.

The analog tuner 200 tunes the frequency band of a specific channel under the control of the controller 220 of the broadcast signals received through the antenna. The tuned transmission call of the tuned frequency band is multiplied by a local oscillation frequency generated by a voltage controlled oscillator (VCO) inside the analog tuner unit 200 in a mixer to become an intermediate wave. Therefore, the analog tuner unit 200 outputs an intermediate wave for a broadcast signal of a specific channel. For example, when the analog tuner unit 200 intends to scan whether an analog broadcast signal exists in each channel by sequentially increasing the channels from the lowest channel among the analog broadcasts, the channel is first controlled by the control unit 220. The frequency corresponding to channel 2 is tuned by changing the value of the variable inductance inside so as to resonate the frequency corresponding to 2. The broadcast signal corresponding to the tuned channel 2 is converted into an intermediate wave of an image 45.75 [MHz] and an audio 41.25 [MHz] and output. After the broadcast signal corresponding to channel 2 is converted into an intermediate wave and output, the analog tuner 200 changes the variable inductance value under the control of the controller 220 to tune the frequency corresponding to channel 3. After that, output the intermediate wave. If the above process is repeated up to the highest channel allocated to the analog broadcast, all channels of the broadcast signal received through the antenna can be scanned.

The synchronization signal detector 210 detects the synchronization signal and outputs the synchronization signal to the controller 220 when the synchronization signal exists in the intermediate wave input from the analog tuner 200. This is because the vertical broadcast signal and the horizontal sync signal exist in the analog broadcast signal, and thus it is to determine whether the analog broadcast signal exists or not. For example, since the synchronization signal includes a narrow horizontal synchronization signal and a wide vertical synchronization signal, the synchronization signals are separated again using a difference of frequency components. In other words, the vertical synchronizing signal 60 [Hz] can be separated by the integrating circuit acting as the low pass filter, and the horizontal synchronizing signal 15750 [kV) can be separated into the differential circuit serving as the high pass filtering. The sync signal detector 210 detects the separated sync signal and inputs it to the controller 220.

The first digital tuner unit 240 tunes a frequency band of a specific channel under the control of the controller 220 of the broadcast signals received through the antenna. The first digital tuner unit 240 tunes the frequency band of the specific channel by changing the value of the variable inductance present therein to resonate the frequency of the specific channel. The tuned frequency is input to an intermediate frequency generator and modulated with a low frequency intermediate wave. The intermediate modulated signal is converted into a digital signal by an analog / digital converter, and the digitally converted signal is input to an I & Q demodulator and demodulated into an I signal and a Q signal. A Fast Fourier Transform (FFT) converter receives the demodulated I and Q signals and converts them into frequency components for output.

The first TPS decoder 250 receives I and Q signals converted into frequency components output by the first digital tuner unit 240. The first TPS decoder 250 sequentially inputs several preset parameters to the received signal and analyzes whether the modulation scheme of the broadcast signal of the channel currently being scanned is correct. The first TPS decoder 250 analyzes whether the signal modulation method is correct, and then inputs a signal for the analysis result to the controller 220.

The second digital tuner unit 260 is used for channel scan of digital broadcasting in a background task of channel scan, and tunes a frequency band of a specific channel under the control of the control unit 220 of the broadcast signal received through the antenna. The second digital tuner unit 260 tunes only the frequency band of the channel where the analog broadcast signal stored in the memory unit 230 exists under the control of the control unit 220, and then outputs the I signal and the Q signal converted into frequency components. do.

The second TPS decoder 270 receives I and Q signals converted into frequency components output by the second digital tuner unit 260. The second TPS decoder 270 analyzes whether the modulation method of the input signal is correct and then inputs a signal for the analysis result to the controller 220.

The memory unit 230 stores the channel number where the synchronization signal is detected in the analog broadcast, and stores the channel number analyzed by the signal modulation method in the digital broadcast.

3A is a flowchart illustrating a main operation in a method of shortening a channel scan time of an analog / digital broadcast image display device according to the present invention. As shown in step S300, analog broadcast channel scanning is started. That is, after receiving the broadcast signal transmitted from the base station through the antenna from the antenna, the scan starts from the lowest channel to search for the channel including the analog broadcast signal. This allows the analog tuner 200 to tune the frequency band of the lowest channel of the analog broadcast under the control of the controller 220 so as to search whether the analog broadcast signal exists from the lowest channel.

In the next step S302, it is determined whether or not an analog broadcast signal exists in the channel currently being scanned. The sync signal detector 210 inputs the sync signal to the controller 220 when a sync signal is detected from the broadcast signal of the channel currently being scanned. The controller 220 determines whether a broadcast signal exists in a channel currently being scanned by the presence or absence of a synchronization signal. This is because in the case of analog broadcasting, it is determined whether an analog broadcasting signal exists with or without a synchronization signal.

If the analog broadcast signal exists in the channel currently being scanned as a result of the determination in step S302, the number of the corresponding channel is stored in the memory unit 230 in step S306. When the synchronization signal is input from the synchronization signal detector 210, the controller 220 stores the number of the channel currently being scanned in the memory 230.

However, if the analog broadcast signal does not exist in the channel being scanned as a result of the step S302, the channel is increased by 1 to search for the presence or absence of the analog broadcast signal for the next channel in step S304. Allows you to scan channels. When the synchronization signal is not input from the synchronization signal detector 210, the controller 220 determines that the next channel of the channel currently being scanned is determined by the analog tuner 200 to determine whether a broadcast signal exists in the next channel. Control to be synchronized.

After storing the channel number in which the analog broadcast signal exists in step S306, it is determined whether the channel of the analog broadcast is terminated in the next step S308. That is, since the analog broadcast is limited in the allocated channel, it is determined whether the analog tuner 200 has tuned the frequency band of the highest channel of the analog broadcast.

If the channel of the analog broadcast is not terminated as a result of the determination in step S308, in step S304, the channel is increased by 1 to continue scanning the channel.

However, if the analog broadcast channel is terminated as a result of the determination in step S308, the scanning of the digital broadcast channel is started in the next step S310. That is, after receiving the broadcast signal transmitted by the base station through an antenna or the like, scanning is started from the lowest channel to search for a channel including the digital broadcast signal.

In the next step (S312) it is determined whether the current scanning channel is the same as the channels of the analog broadcast stored in the memory 230. The controller 220 receiving the channel number of the analog broadcast stored in the memory 230 determines whether the channel to be tuned by the first digital tuner 240 is the same as the channel stored in the memory 230. do.

If the channel currently scanned is not the same as the channels of the analog broadcast stored in the memory unit 230 as a result of the determination in step S312, whether the digital broadcast signal exists in the channel currently scanned in step S314. Navigate. The controller 220 controls the first digital tuner unit 240 so that the frequency of a specific channel is tuned, and the broadcast signal of the tuned specific channel is converted into an I signal and a Q signal of a frequency component and thus the first TPS decoder 250. Is entered. The first TPS decoder 250 analyzes whether the modulation method of the broadcast signal of the channel currently being scanned is correct and outputs a signal to the controller 220. The controller 220 determines whether a digital broadcast signal exists in a channel currently being scanned by the signal input from the first TPS decoder 250.

If the digital broadcast signal exists in the channel currently being scanned as a result of the determination in step S314, the number of the corresponding channel is stored in the memory unit 230 in step S318. However, if the digital broadcast signal does not exist in the channel currently being scanned as a result of the determination in step S314, the channel is increased by 1 to search for the presence or absence of the digital broadcast signal in the next channel in step S316 to continue the channel. To be scanned.

As a result of the determination in step S312, if the channel being scanned is the same as the channel stored in the memory unit 230, it is determined whether the digital broadcasting channel is terminated in the next step S320. That is, the control of the controller 220 determines whether the first digital tuner 240 tunes the frequency band of the highest channel in digital broadcasting.

If the channel of the digital broadcast is not terminated as a result of the determination in step S320, the channel is increased by 1 in step S316 to continue scanning the channel. However, if the digital broadcast channel is terminated as a result of the determination in step S320, all scans are terminated.

According to the method illustrated in FIG. 3A, when a digital broadcast signal exists in a skipped channel during a channel scan process of the digital broadcast, since the corresponding channel is not stored in the memory unit 230, the viewer cannot watch the broadcast of the corresponding channel. Occurs. For example, in Seoul, broadcast signals of the first specific analog broadcast are transmitted through channel 6, and in Busan, broadcast signals of the second specific digital broadcast are transmitted through channel 6. Using the channel scanning method shown in FIG. 3A at the center of Seoul and Busan, channel 6 of the analog broadcast is stored in the memory unit 230 in the channel scan of the analog broadcast, but channel 6 of the channel scan of the digital broadcast is Since skipped, the channel of the second specific digital broadcast is not searched. Therefore, the user may not be able to watch the second specific digital broadcast transmitted from Busan.

In order to prevent the inconvenience, the method for shortening the channel scan time of the analog / digital broadcast image display apparatus according to the present invention includes the analog broadcast channel stored in the memory unit 230 when the analog broadcast channel is stored in the memory unit 230. Whether a digital broadcast signal is present in the field is simultaneously performed as a background task.

In the analog / digital video display device, only the channel scan flow shown in FIG. 3A is displayed on the screen and the background job is not displayed on the screen. In this case, the user waits for the channel scan in FIG. 3A. This is the time when the channel scan process is performed. That is, the background task does not increase the waiting time for the user to scan the channel.

3B is a flowchart illustrating a background operation in a method of shortening a channel scan time of an analog / digital broadcast image display device according to the present invention. As shown in step S400, it is determined whether the channel in which the analog broadcast signal exists is stored in the memory unit 230 in the channel scan of the analog broadcast.

As a result of the determination of step S400, if the channel in which the analog broadcast signal exists is stored in the memory unit 230, the background job of the digital broadcast channel scan is started in step S402. This starts scanning from the lowest channel among the channels of the analog broadcast stored in the memory unit 230.

In the next step S404, it is determined whether a digital broadcast signal exists in the channel currently being scanned.

If the digital broadcast signal exists in the channel currently being scanned as a result of the determination in step S404, the number of the corresponding channel is stored in the memory unit 230 in step S406. However, when the digital broadcast signal is not present in the channel being scanned as a result of the determination in step S404, in step S408, the uppermost nearest to the channel currently being scanned among the channels of the analog broadcast stored in the memory unit 230. Increase channel to channel. When the controller 220 determines that the digital broadcast signal does not exist in the channel currently being scanned, the controller 220 causes the second digital tuner unit 260 of the analog broadcast channels stored in the memory 230 to be present. The second digital tuner unit 260 is controlled to scan the upper channel closest to the channel being scanned. For example, if channels 4, 8, and 9 of the analog broadcast are stored in the memory unit, and the digital broadcast signal does not exist as a result of the 4 channel scan, the controller 220 may scan the 8 channel. The digital tuner unit 260 is controlled.

After storing the number of the channel in which the digital broadcast signal is present in the memory unit 230 in step S406, it is determined whether all channels of the analog broadcast stored in the memory unit have been scanned in the next step S410.

If it is determined in step S410 that all channels of the analog broadcast stored in the memory unit 230 have not been scanned, the most current channel of the analog broadcast channel stored in the memory unit 230 is scanned in step S408. Increase the channel to the nearest higher channel.

However, when all the channels of the analog broadcast stored in the memory unit 230 are scanned as a result of the determination in step S410, the channel scan ends as a background job.

On the other hand, while the present invention has been shown and described with respect to specific preferred embodiments, various modifications and changes of the present invention without departing from the spirit or field of the invention provided by the claims below It can be easily understood by those skilled in the art.

As described above, the present invention can reduce the channel scan time of the analog broadcast and the digital broadcast by scanning the channels of the digital broadcast except the channel in which the analog broadcast signal exists in the analog / digital broadcast combined video display device. The digital display combined with the digital broadcasting can reduce the tedious time that the user waits while scanning the channel, so that the user can watch the broadcasting more conveniently.

Claims (11)

Initiating a channel scan of an analog broadcast; Searching whether an analog broadcast signal exists in a channel currently being scanned; If the analog broadcast signal exists in the channel currently being scanned, storing the number of the channel where the analog broadcast signal exists in the memory unit; Determining whether the analog broadcast channel is terminated; Initiating a channel scan of digital broadcast; Determining whether the channel of the digital broadcast is the same as the channel of the analog broadcast stored in the memory unit; And In the step of determining whether the channel of the digital broadcast is the same as the channel of the analog broadcast stored in the memory unit, if the channel of the digital broadcast is not the same as the channel of the analog broadcast stored in the memory unit, the broadcast signal received through the antenna A method for shortening a channel scan time of an image display apparatus for analog / digital broadcasting, comprising determining whether or not a digital broadcasting signal exists. The method of claim 1, further comprising: increasing the channel by one if the analog broadcast signal does not exist in the channel being scanned in the step of searching whether the analog broadcast signal exists in the channel being scanned. A method of reducing channel scan time of an analog / digital broadcast combined video display device. The image display of claim 1, further comprising increasing the channel by one when the analog broadcasting channel is not terminated in determining whether the analog broadcasting channel is terminated. How to reduce channel scan time of device. The method of claim 1, wherein in the step of determining whether the channel of the digital broadcast is the same as the channel of the analog broadcast stored in the memory unit, the digital broadcast channel is determined if the channel of the digital broadcast is the same as the channel of the analog broadcast stored in the memory unit. The method of shortening a channel scan time of an analog / digital broadcast image display apparatus further comprising the step of determining whether or not it has been terminated. The method of claim 1, wherein determining whether a digital broadcast signal is present in the broadcast signal received through the antenna; Searching whether a digital broadcast signal exists in a channel currently being scanned; Storing the number of the channel where the digital broadcast signal exists in the memory unit when the digital broadcast signal exists in the channel being scanned in the step of searching whether the digital broadcast signal exists in the channel being scanned; And And determining whether or not the digital broadcasting channel has been terminated. 6. The method of claim 5, further comprising: increasing the channel by one if the digital broadcast signal is not present in the channel being scanned in the step of searching whether the digital broadcasting signal is present in the channel being scanned. A method for reducing channel scan time of an analog / digital broadcast combined video display device. 6. The method of claim 4 or 5, further comprising: incrementing the channel by one if the digital broadcasting channel is not terminated in determining whether the digital broadcasting channel is terminated. A method of reducing channel scan time of a broadcast video display device. 2. The method of claim 1, wherein the background task is to determine whether a digital broadcast signal exists in a channel skipped in a channel scan of digital broadcast. step; Starting a background task of a digital broadcast channel scan; And And determining whether or not a digital broadcast signal exists in the channels of the analog broadcast stored in the memory unit. The method of claim 8, wherein the step of determining whether the digital broadcast signal is present in the channels of the analog broadcast stored in the memory unit; Searching whether a digital broadcast signal exists in a channel currently being scanned; Storing the channel number where the digital broadcast signal exists if the digital broadcast signal exists in the channel being scanned in the step of searching whether the digital broadcast signal exists in the channel being scanned; And And determining whether or not all channels of the analog broadcast stored in the memory unit have been scanned. 10. The method of claim 9, wherein in the step of searching for whether a digital broadcast signal exists in the channel being scanned, if no digital broadcast signal is present in the channel being scanned, the analog broadcast channel stored in the memory unit. And increasing the channel from the channel currently being scanned to the nearest higher channel. 10. The method of claim 9, wherein in the step of determining whether all channels of the analog broadcast stored in the memory unit have been scanned, if all channels of the analog broadcast stored in the memory unit have not been scanned, And increasing the channel from the channel currently being scanned to the nearest higher channel.

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