# Patent

## Title
Method for controlling channel tuning of digital TV

## Abstract

A method for controlling channel tuning of a digital TV is disclosed, in which a desired channel can easily be tuned in accordance with a user's input in a digital TV having a channel number of a major-minor type. The method for controlling channel tuning of a digital TV includes the steps of tuning a corresponding channel referring to a corresponding channel data depending on whether channel a data of a major number input by a user exists in a previously stored channel map if the user inputs a major number only, controlling an analog channel if the user inputs a major number or a minor number of 0, and controlling tuning of a corresponding channel depending on whether a channel data of the minor number input by the user exists in the previously stored channel map if the user inputs the major number and the minor number not 0. Since the user can recognize the minor channel data of the desired major channel, it is possible to prevent any confusion in selecting a plurality of minor channels from occurring.

## Background
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a TV, and more particularly, to a method for controlling channel tuning of a digital TV.
2. Background of the Related Art
An analog TV receiver has been commercially used in various types from a small sized TV of 14 inches to a projection TV of 60 inches or greater.
However, the analog TV has several problems in accordance with the trend of a large sized screen and high function. First, when a user views a large sized TV in an analog mode such as NTSC, PAL and SECAM, the user suffers deterioration of picture quality. Second, channels assigned for TV broadcasting are limited to 80 including ultra high frequency channel bands. Actually available ground wave channels are no more than half of the broadcasting channels due to interference between adjacent channels. Third, the analog TV has limitation as a unidirectional medium. In other words, TV has had only a function as a receiving medium but will require a bidirectional function in the future with the spread of personal computer and Internet. Finally, the analog TV has a problem in that its market is completely congested. In other words, since almost every family has two or more analog TVs currently, demand of the analog TV is not expected any longer.
Therefore, to solve the problems of the analog TV market, a digital TV has been developed.
A general digital TV will be described with reference to FIG. 1.
As shown in FIG. 1, the digital TV includes a front end unit 10 for inputting a digital radio frequency (RF) signal and a back end unit 20 for signal processing.
The front end unit 10 includes a tuner/link unit 11 for demodulating the RF signal received through an antenna. The back end unit 20 includes a transport protocol (TP) divider 21, a microprocessor 22, a video/audio decoder 23, an NTSC/PAL encoder 24, an on screen display (OSD)/graphic accelerator 25, a peripheral device processor 26, IEEE1394 27, a traffic controller 28, a DRAM 29 for application software data, and an SRAM 30 for OSD data. The TP divider 21 digitally processes the demodulated RF signal and outputting the digitally processed signal through a monitor and a speaker.
The operation of the aforementioned digital TV will now be described.
A transport packet QPSK modulated by a transmitter is input to the tuner/link 11 thorough the antenna.
The transport packet corresponding to a broadcasting program tuned by a user using a remote controller is divided into audio data, video data, and programmable system information (PSI) by the TP divider 21 under the control of the microprocessor 22 through I2C bus.
The audio data are output to the speaker through the video/audio decoder 23 and an amplifier (not shown) while the video data are output to RGB, Y/C, and CVBS through the video/audio decoder 23 and the NTSC/PAL encoder 24, so that the user can view the video data through a cathode ray tube (CRT) or a flat panel display (FPD).
At the same time, the PSI, i.e., user data, caption data, teletext data, broadcasting guide data, and OSD data, are displayed on a screen, together with the audio signal, through the OSD/graphic accelerator 25.
Meanwhile, the peripheral device processor 26 accesses a remote controller, a GPIO, a smart card, and a modem through an external input terminal so as to interface various broadcasting data and user data.
At this time, the traffic controller 26 controls a flow of a digital signal and a memory access operation of the DRAM 29 and the SRAM 30.
The aforementioned digital TV improves a video quality of the analog TV so as to provide clearer picture quality two times than the analog TV. Since the digital TV has no interference between adjacent channels, channel regions not used conventionally can be used.
According to a program service information protocol (PSIP) which is a broadcasting specific information standard for providing detailed information on a broadcasting program from an advanced television service committee (ATSC) which is a US digital TV standard suggested in November, 1997, a high definition (HD) digital broadcasting program or four standard definition (SD) digital broadcasting programs can be transmitted to a physical channel, i.e., a channel of 6 MHz band. Accordingly, the digital TV has an advantage that can provide various services of several hundred types.
Furthermore, since the digital TV provides bidirectional services to enable Internet service, home shopping service, and home banking service, it is likely to replace an analog channel with a digital channel in the near future. Therefore, it is expected that demand of the digital TV will increase in the future.
The PSIP standard will now be described in more detail. For channel allocation, there are a major channel number and a minor channel number. The major channel number represents a channel number allocated to a band of 6 MHz used for a ground wave broadcasting while the minor channel number represents a channel number allocated to a digital service channel transmitted through a band of 6 MHz.
On the other hand, the ATSC gives each broadcasting station a specific value for the major channel but allows each broadcasting station to manage the minor channel so that the minor channel number can be changed at any time.
The related art digital TV has a problem in that the user cannot tune a corresponding channel if the user does not directly request the minor channel because an easy interface for tuning of the major-minor channel is not provided.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a method for controlling channel tuning of a digital TV that substantially obviates one or more problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a method for controlling channel tuning of a digital TV in which a desired channel can easily be tuned in accordance with a user's input in a digital TV having a channel number of a major-minor type.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a method for controlling channel tuning of a digital TV includes the step of tuning a corresponding channel referring to corresponding channel data depending on whether a channel data of a major number input by a user exists in a previously stored channel map if the user inputs a major number.
In another aspect of the present invention, a method for controlling channel tuning of a digital TV includes the step of controlling tuning of an analog channel if a user inputs a major number and a minor number of 0.
In other aspect of the present invention, a method for controlling channel tuning of a digital TV includes the step of controlling tuning of a corresponding channel depending on whether a channel data of a minor number input by a user exists in a previously stored channel map if the user inputs a major number and a minor number not 0.
It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.



BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:
FIG. 1 is a block diagram illustrating a related art digital TV;
FIG. 2 shows an example of an analog channel allocation;
FIG. 3 shows an example of a digital channel allocation;
FIG. 4 is a flow chart illustrating a method for controlling channel tuning of a digital TV according to the present invention;
FIGS. 5A to 5C show a first embodiment of a method for controlling channel tuning of a digital TV according to the present invention;
FIGS. 6A and 6B show a second embodiment of a method for controlling channel tuning of a digital TV according to the present invention; and
FIGS. 7A to 7D show a third embodiment of a method for controlling channel tuning of a digital TV according to the present invention.



DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
An analog TV channel is used by allocating an RF channel band designated by a federal communication committee (FCC) as a channel number. As shown in FIG. 2, tuning of an analog channel is implemented in such a manner that an allocated channel number is pressed to search a center frequency of a corresponding band and then a modulated signal is demodulated to be displayed on a screen.
For example, if buttons ‘1’ and ‘4’ of a remote controller are pressed, an RF channel number 14 is tuned so that a broadcasting signal of a corresponding broadcasting station is displayed on the screen.
On the other hand, a digital TV channel consists of a major channel number which is a unique number allocated to each broadcasting station and a minor channel number generated by each broadcasting station when a corresponding broadcasting station broadcasts one or more multi-channels. In other words, one broadcasting channel or various broadcasting channels can be transmitted to the RF channel at the same time. In case where a broadcasting station has one or more channels, the broadcasting station multiplexes two broadcasting screens and transmits the multiplexed result to one RF channel not two RF channels.
Referring to FIG. 3, a digital TV broadcasting channel of KBS1 exists in an RF channel number 14 and a digital TV broadcasting channel of KBS2 exists in an RF channel number 18. Digital TV channels of MBC1 and MBC2 exist in an RF channel number 16. A digital channel of SBS is respectively allocated to RF channel numbers 15 and 19. An analog channel is allocated to RF channel numbers 17, 20, and 21.
As described above, the digital TV channel includes a major-minor channel type. The digital TV channel receives not an RF channel number as a major channel number but a unique number of a broadcasting station as a major channel number.
For example, if a broadcasting station KBS has a major number 1, MBC 2, and SBS 3, a digital broadcasting channel of KBS1 transmitted to the RF channel number 14 is 1-1 and a digital broadcasting channel of KBS2 transmitted to the RF channel number 18 is 1-2.
In other words, the related art analog channel can be tuned directly with an allocated RF channel number. However, the digital channel of the major-minor type may not directly tune a desired channel without an exact channel number. Accordingly, the exact channel number should be stored in a channel map by searching whole channels by initial setting after installation of a set.
A method for controlling channel tuning of the aforementioned digital TV will now be described with reference to FIG. 4.
First, it is determined whether a user has input a major number only (S1). As a result of the determination (S1), once the user has input the major number only, a previously stored channel map is searched (S2).
It is determined whether a channel data of the major number input by the user exists in the channel map (S3). As a result of the determination (S3), once the channel data of the major number input by the user does not exist in the channel map, an analog RF channel is tuned so that the tuned channel and the channel data are displayed on the screen (S4 and S5).
Meanwhile, as a result of the determination (S3), once the channel data of the major number input by the user exists in the channel map, it is determined whether the channel data is a digital channel or an analog channel (S6). Subsequently, once the channel data is the digital channel, a corresponding RF channel is tuned referring to the RF channel data through the previously stored channel map (S7).
Digital TV streams input through the tuned RF channel are decoded and updated as the decoded channel data (S8 and S9).
It is then determined whether the updated channel data is equal to the channel data input by the user (S10). As a result, once the updated channel data is equal to the channel data input by the user, audio/video streams of a corresponding minor channel are decoded (S11). The decoded channel and the channel data are displayed on the screen (S12).
Meanwhile, as a result of the determination (S10), once the updated channel data is not equal to the channel data input by the user, audio/video streams of a first minor channel are decoded (S13). The decoded channel and the channel data are displayed on the screen (S14).
Furthermore, as a result of the determination (S6), once the channel data is the analog channel, the analog RF channel is tuned so that a corresponding channel and channel data are displayed on the screen (S15 and S16).
Meanwhile, as a result of the determination (S1), once the user has not input the major number, it is determined whether the user has input major-0 (S17).
As a result of the determination (S17), once the user has input major-0, the analog RF channel is tuned so that the tuned channel and the channel data are displayed on the screen (S18 and S19).
Also, as a result of the determination (S17), once the user has not input major-0, it is determined whether the user has input a minor number not major-0 (S20).
Subsequently, as a result of the determination (S20), once the user has input a minor number not major-0, the previously stored channel map is searched (S21).
It is determined whether the channel data of the major number input by the user exists in the previously stored channel map (S22).
Subsequently, as a result of the determination (S22), once the channel data of the major number input by the user exists in the previously stored channel map, the RF channel is tuned with the major number input by the user (S23). Digital streams input through the tuned channel are decoded and the channel data is updated (S24 and S25).
It is determined whether the minor channel exists in the updated channel data (S26). As a result, once the minor channel exists in the updated channel data, audio/video streams of a major-minor number requested by the user are decoded (S27). The decoded channel and the channel data are then displayed on the screen (S28).
Meanwhile, as a result of the determination (S22), once the channel data of the major number input by the user does not exist in the previously stored channel map, the RF channel is tuned referring to the RF channel data of a corresponding major channel (S29). The digital TV streams input through the tuned RF channel are then decoded (S30).
Subsequently, the decoded channel data is updated, and it is determined whether the updated channel data is equal to the minor channel of the user (S31).
As a result of the determination (S31), once the updated channel data is equal to the minor channel, audio/video streams of a corresponding minor channel are decoded so that the decoded channel and the channel data are displayed on the screen (S32 and S33).
Meanwhile, as a result of the determination (S31), once the updated channel data is not equal to the minor channel, it is determined whether the number of the minor channels of the decoded streams is one (S34). As a result, once the number of the minor channels of the decoded streams is one, audio/video streams of the first minor channel are decoded (S35). The decoded channel and the channel data are displayed on the screen (S36).
Meanwhile, as a result of the determination (S34), once the number of the minor channels of the decoded streams is more than one, a list of total minor channels is displayed on the screen in an OSD type and a desired channel of the user is searched referring to the list (S37).
Then, audio/video streams of the minor channel selected by the user are decoded, and the decoded channel and the channel data are displayed on the screen (S38 and S39).
As described above, the method for controlling channel tuning of the digital TV according to the present invention includes a first embodiment that requires tuning by inputting a major number, a second embodiment that requires tuning by inputting a major number and a minor number of 0, and a third embodiment that requires tuning by inputting a major number and a minor number not 0.
First Embodiment
The first embodiment that requires tuning by inputting a major number only will be described with reference to FIGS. 5A to 5C.
In case where a major number has been only input in a current channel, a video like FIG. 5A is displayed on the screen.
At this time, a channel map which stores an input major number as a channel data is searched. Once the channel map includes a digital channel data, the RF channel data of a digital channel is read and tuned and digital streams input through a corresponding RF channel are decoded. Then, the channel data is again updated because the number of digital channels within a corresponding major channel and a minor number may differ from a previous tuning time period after the digital streams are decoded.
In case where an analog channel exists in a major channel requested by the user in the channel map, or no analog/digital channel exists in the channel map, the analog channel is tuned so that a video like FIG. 5B is displayed on the screen.
Furthermore, audio/video streams of a first minor channel of a corresponding major channel are decoded referring to the decoded channel data, so that a video like FIG. 5C is displayed on the screen. Further, a currently tuning major-minor channel is displayed on the screen so as to allow the user to recognize that the first channel of the major channel selected by the user is being tuned.
Second Embodiment
In case where tuning is requested by inputting a major number and a minor number of 0, an analog channel should directly be tuned. Accordingly, an RF channel equal to the major number is tuned so that videos like FIGS. 6A to 6B are displayed on a screen.
Second Embodiment
In case where tuning is requested by inputting a major number and a minor number not 0, a digital channel should directly be tuned. Accordingly, a video like FIG. 7A is displayed on a screen. Then, it is determined whether a digital channel data of a requested major channel exists in a channel map.
Meanwhile, once a minor number requested by a user does not exist in an updated channel data, the minor number will be displayed on the screen through the following procedure.
Once the digital channel data of the major channel exists, a corresponding RF channel is tuned referring to a stored channel data and then input digital streams are decoded to update a decoded channel data. Once the minor channel number input by the user exists, audio/video streams of a major-minor number requested by the user are decoded so that the decoded streams are displayed on the screen.
As a result of decoding the audio/video streams of the major-minor number requested by the user, once one minor channel of the decoded RF channel exists, the audio/video streams of the decoded major-minor channel are decoded so that the decoded streams are displayed on the screen. After the major-minor channel number of the decoded audio/video streams is displayed, a video like FIG. 7B is displayed to recognize that the major-minor number requested by the user does not currently exist.
Furthermore, if digital streams of a corresponding RF channel consist of various channels but no minor channel requested by the user exists, a list of total minor channels of a decoded major channel is displayed as shown in FIG. 7C in an OSD type. In this case, the user selects a desired channel referring to the list. Audio/video streams of the selected minor channel are decoded so that they are displayed on the screen.
If the major-minor channel requested by the user does not exist in the channel map, an RF channel number equal to the major number is tuned, and the digital streams are decoded. As a result, if the minor number requested by the user exists, audio/video streams of a corresponding major-minor channel are decoded so that the decoded streams are displayed on the screen.
Meanwhile, if no minor number exists, one channel exists within the decoded streams. Accordingly, the channel within the decoded streams is decoded and then displayed on the screen to notify that no minor channel exists. If multi channels exist within the decoded streams, a list of total minor channels is displayed on the screen in an OSD type so that the user selects a desired channel.
As aforementioned, the method for controlling channel tuning of a digital TV according to the present invention has the following advantage.
Since the user can recognize the minor channel data of the desired major channel, it is possible to prevent any confusion in selecting a plurality of minor channels from occurring.
The forgoing embodiments are merely exemplary and are not to be construed as limiting the present invention. The present teachings can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art.

## Claims

1. A method for controlling channel tuning of a digital TV comprising:
making a decision to search a previously stored channel map based on whether a user inputs a major number without inputting a minor number or whether a user inputs a major number and a minor number;
determining whether the major number is a digital channel data or an analog channel data if the major number input by the user exists in the searched channel map;
tuning an RF channel referring to a channel data of a corresponding major channel in the channel map if the major number is a digital channel data;
decoding digital streams input through the tuned RE channel and updating the channel data; and
decoding audio/video streams of a corresponding minor channel to be displayed on a screen if the channel data input by the user is equal to the updated channel data.

2. The method of claim 1, further comprising displaying tuning of a first channel of the major channel selected by the user on the screen if the channel data input by the user is not equal to the updated channel data.

3. The method of claim 1, further comprising tuning an analog RF channel and displaying the tuned analog RF channel on the screen if the major number data input by the user does not exist in the searched channel map.

4. The method of claim 1, further comprising tuning an analog RE channel and displaying the tuned channel and channel data on the screen if the major number data input by the user exists in the searched channel map and is an analog channel.

5. A method for controlling channel tuning of a digital TV comprising:
determining whether a major number input by the user exists in the previously stored channel map if the user inputs the major number and a minor number not 0;
tuning an RE channel referring to an RE channel data of a corresponding major channel if the major number input by the user exists in the previously stored channel map;
decoding digital TV streams input through the tuned RE channel and updating the previously stored channel map; and
decoding audio/video streams corresponding to a major-minor channel input by the user if the minor channel number exists in the updated channel map and displaying the decoded audio/video streams on the screen.

6. The method of claim 5, further comprising:
tuning the RE channel referring to the RE channel data of the corresponding major channel if the input channel data does not exist in the previously stored channel map;
decoding the digital TV streams input through the tuned RE channel;
decoding the decoded channel data;
decoding audio/video streams of the major-minor number requested by the user if the minor channel number input by the user exists in the decoded channel data; and
displaying the decoded streams on the screen.

7. The method of claim 5, further comprising tuning channels depending on the number of minor channels of the decoded streams if the channel data input by the user does not exist in the updated channel data or the minor channel data input by the user does not exist in the decoded channel data.

8. The method of claim 7, further comprising:
decoding audio/video streams of a minor channel if the number of minor channels of the decoded streams is one; and
displaying the decoded channel on the screen and notifying the user that the channel requested by the user does not exist.

9. The method of claim 8, further comprising:
displaying a list of total minor channels if the number of minor channels of the decoded streams is more than one;
selecting a desired channel of the user referring to the displayed list of the total minor channels;
decoding audio/video streams of the minor channel selected by the user; and
displaying the decoded channel and the channel data on the screen.

10. The method of claim 9, wherein the list of the total minor channels is displayed on the screen in an OSD type.

11. A method for controlling channel tuning of a digital TV comprising:
tuning a corresponding channel referring to a corresponding channel data depending on whether channel data of a major number input by a user exists in a previously stored channel map if the user inputs a major number only;
tuning an analog channel if the user inputs a major number or a minor number of 0; and
tuning of a corresponding channel depending on whether a channel data of the minor number input by the user exists in the previously stored channel map if the user inputs the major number and the minor number not 0.

12. The method of claim 11, wherein tuning by inputting the major number and the minor number of 0 is to directly tune an analog channel.

13. The method of claim 11, wherein tuning by the major number and the minor number not 0 is to directly tune a digital channel.

14. A method for controlling channel tuning of a digital TV comprising:
determining whether a channel data of a minor number input by a user exists in a previously stored channel map;
detecting minor channel data from received TV streams, if the channel data of the minor number does not exist in the previously stored channel map;
displaying a list of minor channels based on the detected minor channel data; and
selecting the user 's desired minor channel referring to the displayed list of the minor channels.

15. The method of claim 14, further comprising updating the previously stored channel map to add data related to the selected minor channel.

16. The method of claim 14, wherein the list of the minor channels is displayed on the screen in an OSD type.