KR20000003782A - Method of tuning a different type of broadcasting signal - Google Patents

Abstract

PURPOSE: A method of tuning a different type of broadcasting signal is provided to enhance a user's convenience. CONSTITUTION: The method comprises steps of: detecting a frequency(S201); determining whether a synchronization signal exits or not(S202); determining whether the current signal is PAL mode or not(S203); sequentially storing the input signal at a first memory(S204) in case that the current signal is PAL mode; determining whether the current signal is SECAM in case that the current signal is not PAL mode; storing the input signal at a second memory in case that the current signal is SECAM mode; and repeating above described steps for all of frequency bands. Thereby, it is possible to provide the user's convenience.

Description

Division tuning method of difference broadcasting formula

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tuning method in a television capable of receiving broadcast signals according to a plurality of broadcast methods. In particular, when automatic tuning is performed in a television capable of receiving television broadcast signals according to a plurality of broadcast methods, The present invention relates to a method for distinguishing and tuning heterogeneous broadcasting schemes for storing only tuning frequencies for broadcasting channels.

A typical television receives and demodulates a broadcast signal transmitted from a broadcasting station and outputs the demodulated signal as a video signal and an audio signal through a CRT and a speaker. The approximate components of a typical television that perform these functions are the microcomputer, which manages the overall operation of the system, the intermediate frequency processing module for processing video and audio intermediate frequencies (VIF, SIF), and the received video signals. A video demodulation module for reconstructing an image signal and a deflection module for deflection are separately configured to each module (meaning each chip) to receive and process broadcast signals.

A brief description of a part of the configuration for processing a video signal received in the conventional television system composed of each of the modules as shown in Figure 1, the oscillator 1 for generating an oscillation clock, and The microcomputer 2 which sets the driving timing with the oscillation clock obtained from the oscillator 1 and controls the output control and deflection of the OSD image according to the input synchronization signal and performs the overall control operation for the output of the video and audio. And an intermediate frequency processing module 3 for processing audio and video intermediate frequencies, and a level matching circuit 4 for level matching or automatic fine adjustment between the intermediate frequency processing module 3 and the microcomputer 2. ), A crystal oscillator 5 for oscillating to generate an arbitrary oscillation frequency, a video demodulation module 6 for demodulating the received video signal into an original video signal, and the video A synchronous separation circuit 7 for separating the vertical and horizontal syncs from the signal CVBS demodulated by the error demodulation module 6, a buffer / filter circuit 8 for buffering and filtering the caption signal or the CVBS, and And a deflection module 9 which performs horizontal deflection.

In a conventional TV having a configuration for processing a video signal configured as described above, when a viewer selects a TV / AV mode or an arbitrary channel by using a remote controller, each circuit operates under the control of the microcomputer. By processing the video and audio signal of the channel to be started and tuned, the video is displayed on the CRT, and the audio is transmitted to the speaker so that the viewer can watch the video and audio.

However, the television broadcast signal is different from country to country. For example, France and Eastern European countries (Russia and neighboring countries) use the SECAM method, and Western European countries except France use the PAL method. In addition, the Pacific Rim countries, mainly in the United States, use NTSC-based television broadcasting. In Latin America, PAL-N, PAL-M, and NTSC are mixed.

In addition, the vertical synchronization signal is also different according to the various broadcasting methods. The PAL-N method uses 50 Hz, and the PAl-M and NTSC use 60 Hz as the vertical synchronization frequency, and the difference between the PAL and SECAM methods is based on the center frequency. 2A and 2B, the positions of the video signal and the audio signal are reversed.

That is, in the PAL method, the sound S exists on the left side and the image P exists on the right side based on the center frequency. In addition, in the SECAM method, the image P exists on the left side and the sound S exists on the right side based on the center frequency.

In this case, the portion indicated by S in FIG. 2A and the portion indicated by P in FIG. 2B are located at the same position with respect to the center frequency, which is the same as the portion indicated by P in FIG. 2A and the portion indicated by S in FIG. 2B.

Therefore, in the conventional television broadcast receivers, video signals are processed only in the broadcasting method of the country of use. In Europe, PAL and SECAM are often mixed, and moreover, in terms of economic and industrial aspects, Europe is a culture. In recent years, a TV broadcast receiver (hereinafter, referred to as a TV for receiving a multi-broadcast method) capable of receiving broadcast signals according to different heterogeneous broadcast methods has been provided.

Referring to FIG. 3 to which the broadcasting channel automatic tuning method for the PAL method and the SECAM method is attached in the multi-broadcast reception TV as described above, in step S101, it is determined whether the user selects the negative type modulation mode and the negative type. If it is determined that the modulation mode (PAL mode) is selected, the flow advances to step S102.

In step S102, a frequency is searched, and in step S103, it is determined whether a synchronization signal of a video signal exists in the frequency band currently being searched, and frequency scanning is performed until it is determined that a synchronization signal of a video signal exists. If it is detected, the process proceeds to step S104 and stored in the memory.

Subsequently, in step S105, it is determined whether frequency scanning has been completed over the entire frequency band, and if it is determined that frequency scanning over the entire band has not been completed, the process proceeds to step S102 again. If it is determined in step S105 that the frequency scanning over the entire band has been completed, the process proceeds to step S106 to determine whether the user requests to tune in to another broadcasting scheme. At this time, if there is no channel selection request for another broadcast method, the automatic channel selection mode ends.

On the other hand, it is determined in step S101 that the user selects the negative modulation mode and thus the positive modulation mode (SECAM mode) is selected without selecting the negative modulation mode (PAL mode) or another broadcast in step S106. If it is determined that there is a channel selection request for the method, the flow proceeds to step S107.

The operation from step S107 to step S111 is the same as the operation from step S102 to step S106, and if it is determined in step S111 that a tune-in request for another broadcasting method exists, the flow proceeds to step S102.

According to the above-described automatic channel selection method, the conventional multi-broadcast reception TV stores the frequency of the PAL broadcast channel and the SECAM broadcast channel over the entire region.

However, the above-described automatic tuning method in the conventional multi-broadcast reception TV stores the frequency of the tuning channel based on the presence or absence of a synchronization signal after setting the broadcasting method to be tuned in advance. Since the synchronization signal of the video is also detected in the channel of the broadcasting method different from that of the broadcasting method, the SECAM broadcasting channel is detected in the process of searching for the PAL broadcasting channel, and vice versa.

Accordingly, the frequency information of the channel selected through the process of step S104 and step S109 in FIG. 3 includes frequency information of PAL and SECAM broadcast channels existing in the entire frequency band.

Therefore, for example, when a user requests to watch a PAL broadcast channel, the user may mistake the SECAM broadcast channel when the selected channel is up / down and is displayed in the form of a miscellaneous signal. In particular, the inconvenience of having to perform this reset was presented as a problem.

In addition, a problem of low signal-to-noise ratio and longer tuning time has been proposed.

SUMMARY OF THE INVENTION An object of the present invention for solving the above problems is to store only the tuning frequencies for broadcasting channels of a specific broadcasting method when performing automatic tuning in a television that can receive television broadcasting signals according to a plurality of broadcasting methods. The present invention provides a method for classifying and selecting heterogeneous broadcasting methods.

1 is a schematic structural diagram of a portion for image processing in a conventional television system

2A and 2B are exemplary diagrams for explaining the positional relationship between sound and image of PAL and SECAM.

3 is an exemplary operation sequence for explaining a conventional automatic tuning method.

4 is an exemplary operation sequence for explaining the automatic tuning method according to the present invention.

A feature of the present invention for achieving the above object is a method of automatically tuning a channel in a television that is capable of receiving a broadcast according to a heterogeneous broadcast method, and searching whether or not a synchronization signal exists by searching for a receivable frequency band. A first step of judging, a second step of judging whether a sound system according to negative modulation is applicable when the synchronization signal is detected in the first step, and a sound system according to negative modulation in the second step is determined to be applicable A third step of storing in the first memory area, and a fourth step of storing in the second memory area if it is determined in the second step that the acoustic system according to the negative modulation is not applicable.

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

4 is an exemplary operation sequence for explaining the automatic channel selection method according to the present invention.

If the user requests automatic tuning, step S201 performs frequency scanning from the minimum frequency band of the entire frequency range that can be received. While performing such a frequency search, in step S202 it is determined whether there is a synchronization signal of the video signal in the frequency band currently being searched, frequency scanning is performed until it is determined that the synchronization signal of the video signal exists and the synchronization signal is If it is detected, the process proceeds to step S203.

In step S203, it is determined whether the sound signal exists on the left side or the right side of the synchronization signal detected in step S202. At this time, if it is determined that there is an acoustic signal on the left side (see FIG. 2A attached) with respect to the synchronization signal detected in step S203, the flow advances to step S204 to store the frequency region in which the currently detected synchronization signal exists in the first memory. .

Thereafter, in step S205, it is determined whether frequency scanning has been completed over the entire frequency band, and if it is determined that frequency scanning over the entire band has not been completed, the process proceeds to step S201 again. If it is determined in step S205 that frequency scanning over the entire band has been completed, the automatic tuning mode ends.

On the other hand, if it is determined that there is no sound signal on the left side for the synchronization signal detected in step S203, the flow advances to step S206. In step S206, the sound signal exists on the right side for the synchronization signal detected in step S202 ( 2B).

If it is determined that there is an acoustic signal on the right side with respect to the synchronization signal detected in step S206, the flow advances to step S207 to store the frequency region in which the currently detected synchronization signal exists in the second memory, and then proceeds to step S205.

If it is determined that the acoustic signal does not exist on the right side with respect to the synchronization signal detected in step S206, the automatic tuning mode ends.

By providing a method of discriminating and tuning the heterogeneous broadcasting schemes according to the present invention operating as described above, for example, the PAL scheme may be used when the synchronization signal of the SECAM scheme is tuned during automatic tuning of the PAL broadcast. In the case of requesting viewing of a broadcasting channel, a user can mistake it as a SECAM type broadcasting channel is displayed and displayed in the form of a miscellaneous signal when the tuning channel is up / down, and prior art has to perform resetting separately. Can solve the inconvenience.

Claims (1)

In the method of automatically receiving a channel in a television that can receive a broadcast according to a heterogeneous broadcast method, A first step of searching for a receivable frequency band to determine whether a synchronization signal exists; A second step of determining whether a sound system according to negative modulation is applicable when detecting a synchronization signal in the first step; A third step of storing a sound system according to negative modulation in the second step in a first memory area; And And in the second step, if it is determined that the acoustic system according to the negative modulation is not applicable, storing the second broadcasting method in a second memory area.