KR0120404B1 - A method of anti-memory of overlapping channel for automatic channel memory system - Google Patents

Abstract

To provide a interference channel wrong memory prevention method in automatic channel memory device so suitable as to prevent normal broadcast signal from recording a wrong channel, not existing, by interference of adjacent channel in the case of automatic channel setting. The interference channel wrong memory prevention method includes broadcast signal status discriminating step(S1~S5), interference signal discriminating step(S6), wrong memory prevention step(S7~S9), channel memory step(S7~S9), channel searching step(S10~S12). The broadcast signal status discriminating step(S1~S5) discriminates broadcast signal status in selected channel. The interference signal discriminating step(S6) discriminates whether the interference signal is by adjacent channel if broadcast signal exists according to the result of the broadcast signal status discriminating step(S1~S5). The wrong memory prevention step(S7~S9) is to avoid recording associated channel if the interference signal discriminating step(S6) discriminates a interference signal due to adjacent channel. The channel memory step(S7~S9) records current channel if the step(S6) proves that it is not a interference signal. The channel searching step(S10~12) is to search next channel if broadcast signal doesn't exist in the step(S1~S5). Thereby, it is possible to avoid seeing abnormal broadcast program with displeasure and to reduce automatic setting time by discriminating and ignoring the wrongly recorded channel due to a negative return frequency or other signal interference, comparing the auto fine tuned frequency in upper channel and lower channel in the case of automatic channel setting.

Description

Method of preventing interference channel interference of automatic channel memory

1 is a block diagram of a typical television receiver.

2 is a signal flowchart of an automatic channel storage method of a general television receiver.

3 is an audio / video intermediate frequency waveform diagram applied to a television receiver.

4 is a signal flow diagram for an automatic channel storage method of the present invention.

* Explanation of symbols for main parts of the drawings

1: tuner 2: intermediate frequency processing unit

3: key matrix 4: microcomputer

5: chroma unit 6: speaker

7: Citi

The present invention relates to an automatic channel storage method of a television receiver, and more particularly, to an interference channel of an automatic channel storage device, which is suitable for preventing an incorrect recording of a channel in which a normal broadcast signal does not exist due to interference of an adjacent channel during automatic channel setting. It is about prevention method of coming back.

1 is a block of a general television receiver, as shown therein, a tuner 1 for processing a high frequency signal input through an antenna and extracting an audio and video intermediate frequency, and an audio intermediate frequency output from the tuner 1. The tuner 1 according to a control command of a viewer input through an intermediate frequency processor 2 and a key matrix 3 for restoring an original audio signal by processing a signal and processing an image intermediate frequency to restore an original video signal. Microcomputer (4) for storing the broadcasting channel by controlling the control, and a chroma unit for receiving and processing the video signal of the channel selected by the control of the microcomputer (4) from the intermediate frequency processor (2). The conventional channel storage method will be described with reference to FIGS. 2 and 3, which show a general automatic channel storage method applied to the apparatus. Well below.

When the viewer presses the automatic channel setting key provided in the key matrix 3, the microcomputer 4 recognizes this, and then controls the tuner 1 to sequentially increase the channel while channel number in which the broadcast signal exists first. Remember it all.

After that, the number of channels stored in the first step is increased to display broadcast programs of the corresponding channels in sequence, and at this time, the viewer selects the number of the channel to be stored using the memory key and the erase key. Complete the setup process.

Thereafter, when the viewer operates the channel increase / decrease key, only the channel finally stored in the automatic channel setting process is sequentially increased and decreased so that the viewer can easily select a desired channel without outputting the key signal indicating the desired channel number. Will be.

For reference, in the NTSC television receiver, as shown in FIG. 3, the frequency gap between the channels is set to 6 MHZ, and the video and audio carrier frequencies are set to 45.75 MHZ and 41.25 MHZ, respectively. In the process of scanning a channel to store a desired channel, it is recognized as if a damage signal is present in a channel adjacent to the channel where the broadcast signal exists due to the voice signal carrier of the channel where the broadcast signal exists. This is stored unnecessarily.

As described above, in the conventional automatic channel storage method, due to voice carrier or other signal interference of a channel adjacent to a channel without a broadcast signal, it is recognized as if a broadcast signal exists and the channel is stored unnecessarily. When you select a channel that has a broadcast signal in order to view, memorize, or erase the screen, you need to watch a program that is not in good condition because the channel is stored unnecessarily and you feel uncomfortable. There was a lot of trouble.

Accordingly, the present invention compares the frequencies of the scanned upper N-channels and lower N-1 channels to create a method of preventing a broadcast channel that does not actually exist from being stored due to voice carrier frequencies or other signal interference of adjacent channels. One, it will be described in detail by the accompanying drawings.

The method for preventing interference channel interference in an automatic channel storage device includes: determining whether there is a broadcast signal for a tuned channel; An interference signal discrimination step of discriminating whether an interference signal is caused by an adjacent channel if a broadcast signal exists; A back memory prevention step of not storing the corresponding channel if it is determined as an interference signal by an adjacent channel in the interference signal determination process; A channel storage step of storing a current channel if it is determined that the interference signal is not an interference signal; If it is determined that there is no broadcast signal in the process of determining whether there is a broadcast signal, a channel search process for searching for the next channel is included. This will be described in detail with reference to FIGS. 1 and 4.

When the viewer outputs the automatic channel selection key signal using the key matrix 3, the microcomputer 4 recognizes this and performs the automatic channel selection routine. For example, when scanning from the highest channel, the reference frequency is stored. After storing the highest frequency of the channel + 6MHZ in the register (B), it is checked whether a broadcast signal exists from the highest channel (S1-S5).

If it is determined that there is no channel broadcast signal selected above, the controller proceeds to a channel change step. If it is determined that a broadcast signal exists in the selected channel, the AFT (Auto Fine Tuning) frequency is stored in the scan frequency storage register. Stored in (A) (S6).

Then, the difference between the frequencies stored in the registers (A) and (B) is calculated, and the difference value is compared with the reference frequency (4.5MHZ), and if the difference is less than 4.5MHZ, this is the voice signal carrier of the adjacent channel where the broadcast signal exists. It does not memorize the auto-tuned frequency of the selected channel (top channel) because it is deemed to be misidentified due to the effect of However, if the difference between the frequencies is 4.5MHZ or more, it is determined that the normal broadcast signal of the highest channel exists and stores the auto-tuned frequency of the selected channel (S7-S9).

The reference frequency of 4.5MHZ presented above is an example frequency for being mistaken as if there is a preference in the current channel due to the influence of the voice residual wave of the adjacent channel. That is, an example in which 4.5 MHZ, which is a frequency interval between an image carrier and an audio carrier, is set as a reference frequency is shown.

Through this process, after confirming that a normal broadcast signal exists in the selected channel, the frequency stored in the scan frequency storage register (A) to repeat the above process for the next channel is stored in the reference frequency storage register ( B), and subtract one current channel number to check whether the channel is the preset final channel, and terminate if it is the final channel. However, if the subtracted channel number is not the final channel number, the process is repeated again when all channels are scanned (S10-S12).

As described in detail above, the present invention compares the automatic fine-tuned frequency in the upper channel and the lower channel when setting the automatic channel to distinguish the channel that is incorrectly recognized by the voice carrier frequency or other signal interference of the adjacent channel to determine the channel. By ignoring, there is an effect of eliminating the unpleasantness of having to watch a program having a very bad broadcasting condition, and shortening the channel setting time.

Claims (7)

A broadcast signal discrimination process for determining the presence or absence of a broadcast signal of the tuned channel; An interference signal discrimination step of discriminating whether an interference signal is generated by an adjacent channel based on a difference value between an audio carrier and an image carrier when the broadcast signal exists; A back memory prevention step of not storing the corresponding channel if it is determined as an interference signal by an adjacent channel in the interference signal determination process; A channel storage step of storing a current channel if it is determined that the interference signal is not an interference signal; And a channel searching step of searching for a next channel if it is determined that the broadcasting signal does not exist in the broadcasting signal presence / absence process. The method of claim 1, wherein the interference signal determination process compares the frequency value of the previous channel automatic fine tuning (AFT) with the frequency value of the automatic fine tuning (AFT) of the current channel and discriminates the interference signal when the difference is less than a predetermined value. Method for preventing interference channel interference of automatic channel memory, characterized in that the. 3. The method of claim 2, wherein the predetermined value is 4.5 MHZ. The method of claim 1, wherein the channel search process searches for the channel while raising the channel. 2. The method of claim 1, wherein the channel search process searches while the channel is lowered. 2. The method of claim 1, wherein the comeback prevention process stores the current channel without storing the previous channel. 2. The method of claim 1, wherein the back memory prevention process stores a previous channel and does not store a current channel.