KR100681579B1 - Method for searching a channel in a broadcasting receiving - Google Patents

Abstract

A channel tuning method of a broadcasting signal receiver is provided to rapidly and efficiently search channels by providing an interface for selecting whether an AFT(Automatic Fine Tuning) function is activated using an OSD(On Screen Display) image and selectively executing the AFT function to tune a channel. A channel tuning method of a broadcasting signal receiver includes a step of determining whether the broadcasting signal receiver is set in a channel tuning mode, a step of providing an interface through which an AFP function is on or off when the channel tuning mode is set, a step of activating the AFT function to tune a channel when the AFT function is on, a step of receiving a broadcasting signal of each channel and detecting a synchronous signal of the received broadcasting signal when the AFT function is off(S208), and a step of performing channel tuning using the detected synchronous signal.

Description

Channel tuning method of broadcast receiving device {METHOD FOR SEARCHING A CHANNEL IN A BROADCASTING RECEIVING}

1 is a hardware block diagram of a broadcast receiving apparatus for a channel tuning method according to the present invention,

2 is a flowchart illustrating an operation process when a user selects to turn off an AFT function during channel automatic tuning according to an embodiment of the present invention.

3 is a flowchart illustrating an operation process when a user selects an AFT function on channel auto-tuning according to an exemplary embodiment of the present invention.

<Description of the code | symbol about the principal part of drawing>

100: key input unit 102: microcomputer

104: tuner 106: synchronization detection unit

108: signal processor 110: memory

112: OSD unit

The present invention relates to a broadcast receiving apparatus, and more particularly, to a channel tuning method of a broadcast receiving apparatus.

In general, the channel auto-tuning function determines a channel to which a broadcast signal is input among all broadcast channels as a presence or absence of a synchronization signal and stores the channel to which the broadcast signal is input in a memory, so that when a user switches a channel, that is, a channel up / down It is a function that facilitates channel switching by only up / down channels on which broadcasting is performed at a time.

On the other hand, in order to receive signals in these frequency bands in a television or cable broadcasting system in which various frequency bands, ie, multiple channels are broadcast, the tuner must be tuned to the carrier frequency of the channel to be received.

NTSC (National Television System Committe) FS (Frequency Synchronizing) method adopts AFT (Automatic Fine Tunning) voltage to tune the tuner of the receiver to the carrier frequency of each channel. . That is, when the PLL data for tuning the frequency of each channel is stored in the memory inside the microcomputer of the receiving apparatus and the user selects a predetermined channel by dial or the like, the microcomputer applies the PLL data of the selected channel to the tuner.

On the other hand, a phase locked loop is formed in the tuner to control the oscillation frequency of the voltage controlled oscillator according to the PLL data, thereby receiving the frequency signal of the channel selected by the user.

However, since the carrier frequency of the signal transmitted from the broadcasting station varies slightly depending on the region or environment, it is necessary to change the oscillation frequency of the voltage controlled oscillator in order to synchronize the carrier frequency with the tuner.

To this end, in the FS method, the AFT voltage is output according to the frequency of the IF signal output from the tuner, and the microcomputer changes the PLL data according to the AFT voltage.

That is, in the FS method, by changing the PLL data output by the microcomputer, the local oscillation frequency of the tuner is changed slightly to check whether a synchronization signal is detected, and when the synchronization signal is detected, the broadcast signal is recognized and the channel fine adjustment, In other words, the window search is performed.

In the case of the window search, the PLL data is finely changed in predetermined step units and applied to the tuner so that the applied AFT voltage becomes an intermediate voltage within a predetermined window range, for example, 2.8 V to 3.8 V. Accordingly, the frequency of the intermediate frequency (IF) signal output from the tuner was set to 45.75 MHz.

More specifically, first find the AFT high voltage (approximately 2.8V), then find the AFT low voltage (approximately 1.8V), and then find the PLL data applied to the tuner when the AFT high voltage is found and the tuner when the AFT low voltage is found. The channel fine tuning is terminated by applying to the tuner an intermediate value of the PLL data applied to the PLL data, that is, the PLL data value applied to the optimum AFT voltage.

However, as described above, since the carrier frequency of the signal transmitted from the broadcasting station is slightly changed according to the region or environment, and the frequency band in which the synchronization signal is detected per channel can be distributed in several bands, the AFT characteristics, the broadcasting state, and the number of channels As a result, the channel search may not only take a long time but also may not be accurate.

In particular, despite the recent development of broadcasting technology, many areas that do not require channel search using the AFT function have been created. However, since a general broadcast receiving device searches for broadcastable channels using the AFT function, the channel search time is increased. There is a long n problem.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art, and provides an interface for selecting whether to enable or disable the AFT function by using an OSD screen when channel selection is requested, and then selectively perform the AFT function according to a user's selection. The present invention provides a channel tuning method of a broadcast receiving device that tunes a channel by executing.

Another object of the present invention is to pre-set at least one or more channels to perform channel tuning with the AFT function, and then tune the channel using the AFT voltage and the synchronization signal for the set channels, and use only the synchronization signal for the channel. The present invention provides a channel tuning method of a broadcast receiving apparatus that performs channel tuning.

In order to achieve the above object, the present invention provides a channel tuning method of a broadcast receiving apparatus for receiving a broadcast signal, comprising: determining whether the broadcast receiving apparatus is set to a channel tuning mode, and setting the channel tuning mode; Providing an interface for selecting on or off of the AFT function, activating the AFT function when the AFT function is on, and performing channel tuning when the AFT function is turned off; Detecting a synchronization signal of the received broadcast signal after receiving the signal; and performing channel tuning using the detected channel-specific synchronization signal.

In order to achieve another object of the present invention, the present invention provides a channel tuning method of a broadcast receiving apparatus that receives a broadcast signal, and provides a channel for setting whether the AFT function is on or off for each channel, and then sets a channel set to the interface. Storing information on whether the AFT function is applied to each memory in the memory; determining whether the AFT function for the corresponding channel is on or off by searching the memory when the broadcast receiving apparatus is set to the channel tuning mode; Determining whether the corresponding channel is a broadcast-receivable channel by activating the AFT function when the AFT function for the corresponding channel is on; and when the AFT function for the corresponding channel is off, Detects a synchronization signal of the received broadcast signal after receiving the On the basis of the call comprises a step in which the corresponding channel is determined whether or not the received broadcast channels.

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

1 is a hardware block diagram of a broadcast receiving apparatus for a channel tuning method according to the present invention, which includes a key input unit 100, a microcomputer 102, a tuner 104, a synchronization detector 106, a signal processor 108, and a memory. 110 and an OSD unit 112.

In this configuration, the key input unit 100 is provided with a plurality of keys including a tuning key for channel automatic tuning, etc., and inputs a key signal corresponding to a user's key operation to the microcomputer 102 so that an input at a conventional remote location is performed. By using a remote control possible, and detects the key signal carried on the red gangster broadcast wave from the remote control to apply to the microcomputer (102).

The microcomputer 102 is a means for controlling the overall operation of the video device based on the key signal from the key input unit 100. When the tuning key signal is input through the key input unit 100 as can be seen from the description below. The OSD unit 112 is controlled to display an OSD screen on which a AFT function can be turned on or off on a display device (not shown).

When the user selects the AFT function on, the microcomputer 102 sequentially reads the PLL data corresponding to each channel from the lowest channel to the highest channel to the tuner 104, and outputs the tuner 104. After tuning the channel based on the AFT voltage and the frequency band of the synchronization signal from the synchronization detector 106, the tuned channel is stored in the memory 110.

Here, when the user selects to turn off the AFT function, the microcomputer 102 sequentially reads the PLL data corresponding to each channel from the lowest channel to the highest channel from the memory 110, outputs the PLL data to the tuner 104, and then synchronizes the detection unit 106. The channel is tuned based on the frequency band of the synchronization signal from the channel, and the tuned channel is stored in the memory 110. That is, when the user selects to turn off the AFT function, the microcomputer 102 performs channel selection using only the frequency of the synchronization signal output from the synchronization detector 106 without receiving the AFT voltage from the tuner 100.

The tuner 104 is configured to receive a broadcast signal of a channel corresponding to PLL data which is a tuning signal of the microcomputer 102 among a plurality of broadcast frequency signals transmitted from a broadcasting system of a broadcasting station, and under the control of the microcomputer 102. The voltage according to the tuning state is selectively applied to the microcomputer 102.

In addition, the tuner 104 is connected to the sync detector 106, and the sync detector 108 separates and detects a sync signal from the broadcast signal received from the tuner 104 and provides it to the microcomputer 102.

On the other hand, under the control of the microcomputer 102, the signal processor 108 analyzes the video signal and the audio signal based on the broadcast signal from the tuner 104, and processes the video and audio signals into easy-to-display and output signals to monitors and speakers. Each of the outputs allows the user to watch the broadcast of the channel selected by the user.

A process of automatic channel tuning by the broadcast receiving device having the above configuration will be described with reference to FIGS. 2 and 3.

2 is a flowchart illustrating an operation process when a user selects an AFT function off when channel auto tuning is performed according to a preferred embodiment of the present invention. FIG. 3 is a flowchart illustrating an AFT function when a user automatically tunes a channel according to an exemplary embodiment of the present invention. If ON is selected, a flowchart illustrating an operation process is shown.

As shown in FIG. 2, first, when the channel automatic tuning key signal is applied from the key input unit 100 in step S200, the microcomputer 102 may control the OSD unit 112 to turn on or off the AFT function. Is displayed on a predetermined display device (S202).

Thereafter, the microcomputer 102 determines whether a key signal for turning on or off the AFT function is input from the key input unit 100 (S204).

As a result of the determination in step S204, when a key signal for turning off the AFT function from the key input unit 100 is applied to the microcomputer 102, the microcomputer 102 reads the PLL data corresponding to the lowest channel from the memory 110 to tuner ( The tuner 104 outputs the broadcast signal received by being tuned to the channel corresponding to the applied PLL data to the synchronization detector 106 (S206).

Accordingly, the sync detector 106 receives a broadcast signal from the tuner 104, separates the sync signal from the broadcast signal, and outputs the sync signal to the microcomputer 102 (S208).

The microcomputer 102 determines whether the frequency band of the synchronization signal provided from the synchronization detector 106 is between 40 and 60 MHz (S210).

As a result of the determination in step S210, when the frequency band of the synchronization signal is included in 40 to 60 MHz, the microcomputer 102 stores the channel frequency as a broadcastable channel in the memory 110 and then determines whether the channel currently received by the tuner 104 is the highest channel. It is determined (S212, S214).

As a result of the determination in step S210, when the frequency band of the synchronization signal is not included in 40 to 60 MHz, the microcomputer 102 performs step S214.

As a result of the determination in step S214, when the channel is not the highest channel, the microcomputer 102 reads PLL data corresponding to the next channel from the memory 110 (S216), and returns to step S206 to perform a subsequent step.

On the other hand, if the key signal for turning on the AFT function is applied from the key input unit 100 as a result of the determination in step S204, as shown in FIG. 3, the microcomputer 102 stores the PLL data corresponding to the lowest channel in the memory 110. Reads the signal to the tuner 104, and the tuner 104 outputs a broadcast signal received by being tuned to a channel corresponding to the applied PLL data, and outputs an AFT voltage corresponding to a reception state of the broadcast signal. 102) (S300, S302).

Accordingly, the microcomputer 102 determines whether the AFT voltage output from the tuner 104 is 1.8 to 3.2 V (S304).

As a result of the determination in step S304, when the AFT voltage is 1.8 to 3.2V, the microcomputer 102 controls the sync detector 106 to receive the sync signal detected by the sync detector 106 (S306).

The microcomputer 102 determines whether the frequency band of the synchronization signal provided from the synchronization detector 106 is between 40 and 60 MHz (S308).

As a result of the determination in step S308, when the frequency band of the synchronization signal is included in 40 to 60 MHz, the microcomputer 102 stores the channel frequency as a broadcastable channel in the memory 110 and then determines whether the channel currently received by the tuner 104 is the highest channel. Determine (S310, S312).

As a result of the determination in step S308, when the frequency band of the synchronization signal is not included in 40 to 60 MHz, the microcomputer 102 performs step S312.

As a result of the determination in step S312, when the channel is not the highest channel, the microcomputer 102 reads the PLL data corresponding to the next channel from the memory 110 (S314), and returns to step S300 to perform a subsequent step.

In the preferred embodiment of the present invention, the channel is tuned using the AFT function selectively or the channel is tuned using only a synchronization signal without the AFT function according to the on / off of the AFT function from the lowest channel to the highest channel. In another embodiment, at least one channel to perform channel tuning with the AFT function is preset, and the channel is tuned using the AFT voltage and the synchronization signal for the set channels, and the other channels are synchronized. Channel tuning can be performed using only signals.

According to the present invention, by providing an interface for selecting whether to activate the AFT function by using the OSD screen when channel selection is requested, by selectively executing the AFT function according to the user's selection, the channel can be quickly searched. Can be.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

As described above, the present invention provides an interface for selecting whether to activate the AFT function using an OSD screen when channel selection is requested, and then selectively executes the AFT function according to the user's selection to tune the channel quickly. Not only can you search for, but you can also search for channels effectively.

Claims (3)

A channel tuning method of a broadcast receiving device that receives a broadcast signal, Determining whether the broadcast reception device is set to a channel tuning mode; If the channel tuning mode is set, providing an interface for selecting on or off of an AFT function; Activating the AFT function to perform channel tuning when the AFT function is turned on; Detecting a synchronization signal of the received broadcast signal after receiving the broadcast signal for each channel when the AFT function is turned off; Performing channel tuning using the detected channel-specific synchronization signal Channel tuning method of a broadcast receiving device comprising a. The method of claim 1, The interface is a channel selection method of the broadcast receiving device, characterized in that the OSD screen to select the on or off of the AFT function. A channel tuning method of a broadcast receiving device that receives a broadcast signal, Providing an interface for setting whether the AFT function is turned on or off for each channel, and storing information on whether to apply the AFT function for each channel set in the interface in a memory; When the broadcast reception device is set to a channel selection mode, determining whether the AFT function for the corresponding channel is on or off by searching the memory; Determining whether the corresponding channel is a broadcast-receivable channel by activating the AFT function when the AFT function for the corresponding channel is on; When the AFT function for the corresponding channel is off, after receiving a broadcast signal for the corresponding channel, a synchronization signal of the received broadcast signal is detected, and the corresponding channel is broadcast-receivable channel based on the detected synchronization signal. Determining whether or not Channel tuning method of a broadcast receiving device comprising a.

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