KR100925730B1 - How to Scan Channels on Digital Television - Google Patents

Abstract

The present invention relates to a channel scan method of a digital television. In the related art, a channel scan operation scans an analog broadcast channel and then sequentially scans an entire digital broadcast channel, thereby increasing the time required to scan the entire channel. there was. In view of the above problems, the present invention provides a method comprising: a first step of performing respective channel scans on an air channel of an ATSC and an air channel of an NTSC using a first and a second tuner; And a second step of performing a channel scan on the cable channel of the NTSC using the first and second tuners, thereby performing a channel scan using a built-in tuner at the same time, thereby reducing the time required to scan the entire channel. It works.

Description

Channel scanning method of digital television {CHANNEL SCAN METHOD FOR DIGITAL TELEVISION}

1 is a block diagram showing the configuration of a broadcast receiving apparatus of a conventional digital television;

2 is an operation flowchart showing a channel scanning method of a conventional digital television;

3 is a flowchart illustrating a method of simultaneously scanning digital AT broadcast and analog NT broadcast using an AT tuner and an AT tuner in a channel scan method of a digital television according to the present invention.

4 is a flowchart illustrating a method of simultaneously scanning an analog NTS broadcast by using two NTC tuners in a channel scan method of a digital television according to the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a channel scan method of a digital television, and more particularly, to a channel scan method of a digital television which makes it possible to shorten the time taken to scan a plurality of broadcast channels.

In general, in order to use a television for the first time, a user scans a channel that is currently being broadcast and stores it in an internal memory. Then, the user moves to a channel that is stored when watching a television and watches a broadcast program that appears on the screen.

The channel scan operation is called an automatic channel scan. The scan of the broadcast channel is performed over all channels. Typically, analog television will scan approximately 180 channels, and digital television will scan 250 to 290 channels, including digital broadcasts.

Recently, commercially available digital televisions are equipped with two tuners as shown in FIG. 1 to support the PIP function. In the case of a normal analog television, one tuner shows the main picture, and the other tuner scans the entire channel on the PIP screen. That is, all 180 channels are scanned using only one tuner.

In addition, in digital television, analog channel and digital channel are scanned twice. In this case, the scan time is long because only one tuner is scanned.

The analog NTSC channel is divided into an air channel and a cable channel, and the digital ATSC channel is also divided into an air channel and a cable channel. In general, in the case of the air channel in the AT / C channel, 2 to 69 channels are used, and in the case of cable channels, 1 to 14 to 125 channels are used.

In digital television, channel scans also perform digital broadcast channel scans in addition to analog broadcast channel scans.

FIG. 2, which is an exemplary embodiment of the related art, is a flowchart of a method of scanning a channel of a conventional digital television. As shown in FIG. (S11-S15); Storing channel information on the channel where the signal is detected while increasing the channel by tuning to the NC cable channel when the channel scan of the NC air channel is finished (S16 to S20); When the channel scan of the NC cable channel is completed, tuning to a digital air channel is performed to store channel information on a channel where a signal is caught while increasing the channel (S21 to S26).

In the last step (S21 ~ S26) it may be operated in the step (S27 ~ S31) for storing the channel information for the channel is caught while increasing the channel by tuning to the cable channel without tuning to the digital air channel.

In the case of analog channels, both channel scans are performed because both air and cable broadcasts exist, but in the case of digital channels, only the air channels are available in Korea.

That is, in digital television, channel scanning is performed three times: analog air channel and analog cable channel, digital air channel or digital cable channel.

However, in the prior art as described above, as the channel scan operation scans the analog broadcast channel and then sequentially scans the digital broadcast channel, the time required to scan the entire channel increases.

Accordingly, the present invention has been made in view of the above problems, and in the digital television equipped with two or more tuners in order to support PIP, scanning is performed simultaneously using the built-in tuner to increase the channel scan speed. It is an object of the present invention to provide a channel scanning method of a digital television.

The present invention for achieving the above object, the first step using the first and second tuner to perform the respective channel scan for the air channel of the ATSC and the air channel of NTSC; And a second step of performing a channel scan on the cable channel of the NTSC using the first and second tuners.
In addition, the present invention for achieving the above object, the first step using the first and second tuner to perform the respective channel scan for the cable channel of the ATSC and the cable channel of the NTSC; And a second step of performing a channel scan on the air channel of the NTSC by using the first and second tuners.
In addition, the present invention for achieving the above object, by using a first tuner to set the frequency corresponding to the first channel included in the channel of the NTSC, using a second tuner included in the channel of the NTSC Setting a frequency corresponding to a second channel; Determining whether a channel is valid based on a channel lock signal output through the first tuner and the second tuner, and storing corresponding channel information when the channel is valid; And a third step of repeating the first and second steps with respect to all channels included in the channel of the NTSC.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Analog and digital have different methods for determining the presence of a channel through a tuner.

In the case of analog NTS broadcast, it is determined that the channel is valid by setting the channel frequency to the tuner and reading the AFT voltage value or determining the synchronization.

At this time, the time required to determine the presence or absence of the channel frequency after setting up most of the time and the time to set the actual channel frequency to the tuner is relatively small.

In the case of digital AT broadcast, the channel frequency is set in the tuner, and the digital data output through the VSB decoder is analyzed to determine the validity of the channel.

The time required is relatively longer than analog broadcasting, and it takes a lot of time to determine the channel presence by analyzing digital data.

3 is a flowchart illustrating a method of simultaneously scanning digital AT broadcast and analog NT broadcast using an AT tuner and an AT tuner in a channel scan method of a digital television according to the present invention. Setting a frequency corresponding to the air channel in the AT tuner and setting a frequency corresponding to the air channel in the AT tuner when the channel scan is started for the air channel during digital broadcasting (ST11 to ST13); In the case of the NTS channel, the validity of the channel is determined and stored as a channel lock (or presence or absence) signal, and in the case of the AT channel, after receiving the channel lock signal, the digital data inputted through the VSB decoder is analyzed and the channel is present. Determining and storing the information (ST14, ST15); Determining whether the channel value is the last after increasing the channel value or repeating the above process (ST16, ST17); Setting a frequency corresponding to an air channel in the AT tuner when the channel scan is started for the cable channel during the digital broadcasting, and setting a frequency corresponding to the air channel in the AT tuner (ST18, ST19); In the case of the NTS channel, the validity of the channel is determined and stored as a channel lock (or presence or absence) signal, and in the case of the AT channel, after receiving the channel lock signal, the digital data inputted through the VSB decoder is analyzed and the channel is present. Determining and storing the data (ST20, ST21); After increasing the channel value, it is determined whether the channel value is the last, or the above steps are repeated (ST22, ST23).

The above method is applied to a digital television having an AT / NT C combined tuner and an NTS tuner or an AT / T tuner and an NTS tuner, which will be described below.

Digital AT broadcasts and analog NT broadcasts use the same band, so two broadcasts can be scanned with just one scan time.

Prior to the channel scan, it is determined whether to perform a channel scan on an air channel or a cable channel among digital broadcasting channels (ST11). Here, assume that a channel scan is performed on the air channel.                     

First, a frequency corresponding to an air channel is set in the AT tuner (ST12). Then, the frequency corresponding to the air channel is set in the NTC tuner (ST13).

The channel lock signal is then waited from the two tuners.

In case of NTS channel, channel lock (or sync) is used to determine the validity of the channel, and in case of AT channel, after receiving the channel lock signal, it analyzes the digital data input through VSB to determine the presence of the channel. Save it (ST14, ST15).

After increasing the channel value, it is determined whether the channel value is the last, or the above process is repeated (ST16, ST17).

On the contrary, if the channel scan is performed on the cable channel among the digital channels, the frequencies corresponding to the cable channel are set in the AT tuner and the AT tuner (ST18, ST19). And the subsequent process is the same as described above.

FIG. 4 is a flowchart illustrating a method of simultaneously scanning an analog NTS broadcast by using two NTS tuners in a channel scan method of a digital television according to the present invention. As shown in FIG. Setting a frequency corresponding to the cable channel to the AT / C CC tuner and setting a frequency corresponding to the cable channel +1 to the AT tuner if the channel scan is performed on the channel (ST24 and ST25); Waiting for a channel lock signal from the two tuners and determining and storing validity of two NTS channels using the channel lock (or presence of sync) signal (ST26, ST27); Increasing the cable channel value corresponding to the frequencies set in the two tuners by 2, determining whether the channel value is the last channel, or repeating the above process (ST28, ST29); If the channel scan is performed on the cable channel during the digital channel scan, setting a frequency corresponding to an air channel on an AT / C tuner and setting a frequency corresponding to an air channel + 1 on an AT tuner. (ST30, ST31); Waiting for a channel lock signal from the two tuners and determining and storing validity of two NTS channels using the channel lock (or presence or absence of sync) signal (ST32, ST33); After increasing the cable channel values corresponding to the frequencies set in the two tuners by 2, it is determined whether the channel value is the last channel or repeating the above steps (ST34 and ST35).

The above method is applied to a digital television having an AT / C combined tuner and an NTS tuner or an analog television having two or more NT tuners, which will be described below.

Suppose that the method is applied to a digital television with an AT / NC tuner and an NT tuner.

If a channel scan is performed on the air channel in the digital channel scan shown in FIG. 3, the frequency corresponding to the cable channel is set in the AT / C tuner (ST24).

In addition, the frequency corresponding to the cable channel + 1 is set to the NTC tuner (ST25).

Waiting for a channel lock signal from the two tuners, the channel lock (or presence / absence) signal is used to determine and store the validity of the two NC channels (ST26 and ST27).                     

After the channel value is increased by 2, it is determined whether the channel value is the last channel or the above process is repeated (ST28, ST29).

On the contrary, if the channel scan is performed on the cable channel during the digital channel scan, the channel scan is performed on the NC air channel.

To this end, as described above, the frequency corresponding to the air channel is set in the AT / C CC tuner, and the frequency corresponding to the air channel +1 is set in the AT dedicated tuner (ST30 and ST31). And the subsequent process is the same as the process described above.

As another example, when applied to an analog television having two or more NTS tuners, two tuners complete a channel scan on the cable channel and then perform a channel scan on the air channel.

As described in detail above, the present invention can reduce the channel scan time by performing the channel scan operation using two tuners. In the case of a general analog television, the two NT tuners are used simultaneously to adjust the scan time. In the case of digital television, AT & C scans at the same time, and the other NT broadcast is also scanned using two tuners, thereby reducing the channel scan time.

In addition, if the user does not have the knowledge about the broadcast signal coming into his home, and there is a difficulty in scanning the channel, the television itself needs to scan all cases to find the broadcast. It feels good.

Claims (11)

A first step of performing respective channel scans on the air channel of the ATSC and the air channel of the NTSC using the first and second tuners; And And a second step of performing a channel scan on a cable channel of an NTSC using the first and second tuners. The method of claim 1, wherein the first step is A first step of setting a frequency corresponding to an air channel of the ATSC by using the first tuner, and setting a frequency corresponding to an air channel of the NTSC by using the second tuner; A second process of determining whether a channel is valid based on signals output through the first tuner and the second tuner, and storing corresponding channel information when the channel is valid; And And a third process of repeating the first and second processes with respect to all channels included in the air channel of the ATSC and the air channel of the NTSC. The method of claim 1, wherein the second step, A fourth step of setting a frequency corresponding to a cable channel of the NTSC by using the first tuner and the second tuner, respectively; A fifth process of determining whether a channel is valid based on signals output through the first tuner and the second tuner, and storing corresponding channel information when the channel is valid; And And a sixth process of repeating the fourth and fifth processes for all channels included in the cable channel of the NTSC. A first step of performing respective channel scans of the cable channel of the ATSC and the cable channel of the NTSC using the first and second tuners; And And a second step of performing a channel scan on an air channel of an NTSC by using the first and second tuners. The method of claim 4, wherein the first step, A first step of setting a frequency corresponding to the cable channel of the ATSC by using the first tuner and setting a frequency corresponding to the cable channel of the NTSC by using the second tuner; A second process of determining whether a channel is valid based on signals output through the first tuner and the second tuner, and storing corresponding channel information when the channel is valid; And And a third process of repeating the first and second processes for all channels included in the cable channel of the ATSC and the cable channel of the NTSC. The method of claim 4, wherein the second step, A fourth step of setting a frequency corresponding to an air channel of the NTSC by using the first tuner and the second tuner, respectively; A fifth process of determining whether a channel is valid based on signals output through the first tuner and the second tuner, and storing corresponding channel information when the channel is valid; And And a sixth process of repeating the fourth and fifth processes for all channels included in the air channels of the NTSC. The method of claim 2 or 5, wherein the second process, In the case of an NTSC channel, determining whether the channel is valid based on a channel lock signal and storing corresponding channel information in the case of a valid channel; And determining the validity of the channel based on the digital data input through the VSB decoder, and storing the corresponding channel information in the case of the ATSC channel. According to claim 3 or 6, wherein the fifth process, And determining the validity of the channel based on the channel lock signal and storing corresponding channel information when the channel is valid. Setting a frequency corresponding to a first channel included in a channel of the NTSC using a first tuner, and setting a frequency corresponding to a second channel included in the channel of the NTSC using a second tuner; Determining whether a channel is valid based on a channel lock signal output through the first tuner and the second tuner, and storing corresponding channel information when the channel is valid; And And a third step of repeating the first and second steps with respect to all channels included in the channels of the NTSC. The method of claim 9, wherein the channel, A channel scanning method for digital television, characterized in that it is an air channel or a cable channel. The method of claim 9, wherein the second channel, And a channel value obtained by adding one channel value to the channel value of the first channel.

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