KR20000040871A - Method for scanning automatically channels of television with pip capability - Google Patents

Abstract

PURPOSE: A method for scanning automatically channels of a television with PIP(picture in picture) capability is provided to increase the scanning speed and to improve scanning fidelity. CONSTITUTION: A method for scanning automatically channels of a television with PIP capability includes first thru third steps. At the first step(S100), whether channel automatic scan key is input is determined. At the second step(S110), the channel is stored when a recognition code is detected while scanning channels sequentially. At the third step(S130), a synchronous signal of the channel with recognition code is detected by another tuner and the final channel information is stored when the best broadcasting signal is received.

Description

Automatically channel searching method for a television with PIP function

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a channel automatic search method of a television, and more particularly, to a channel automatic search method of a television having a two-tuner and having a picture in picture (PIP) function.

In general, the PIP function of a television is provided with two tuners for receiving and tuning a broadcast signal transmitted from a broadcasting station, so that a screen can be divided into a main area and a plurality of sub-areas to simultaneously watch broadcast signals of multiple channels. The user can simultaneously search for or watch other broadcast signals of the sub picture displayed in the sub area while watching the broadcast of the main picture displayed in the main area.

In this case, the PIP process converts two broadcast signals or one broadcast signal (for a sub-screen) into a digital signal, performs image reduction processing for adjusting the screen size, and synthesizes the two broadcast signals to match the desired home screen position. Convert it back to a signal and process it.

Therefore, the PIP function allows the viewer to watch two broadcasts at the same time, so that it is possible for the user to search for another broadcast on the sub-screen while watching the desired broadcast on the main screen.

1 is a schematic block diagram of a television having a conventional general PIP function, and includes a key input unit 100, an EEPROM 110, a microprocessor 200, first and second tuner units 300 and 500, and a first one. And a two image signal processors 400 and 600, a PIP processor 700, an RGB converter 800, and a monitor 900.

In this configuration, the key input unit 100 is provided with a plurality of keys for performing the operation of the television outputs a key signal corresponding to the user's key operation, typically using a remote control that can be input from a remote location of the user A key signal corresponding to a key operation is loaded on a predetermined infrared signal and transmitted, the received infrared signal is received, detected, amplified, and waveform-formed to output the received key signal.

The EEPROM 110 stores a television broadcasting system, color standard, channel information, and the like.

The microprocessor 200 selectively selects the first and second tuner units 300 and 500, the first and second image signal processors 400 and 600, and the PIP processor 700 based on the key signal from the key input unit 100. To control the overall operation of the television.

Meanwhile, the first and second tuner units 300 and 500 output broadcast signals received by tuning to channels corresponding to the control of the microprocessor 200 to the first and second image signal processing units 400 and 600, respectively. .

Next, the first and second video signal processing units 400 and 600 separate the video signals from the broadcast signals from the first and second tuners 300 and 500, respectively, and output the video signals to the PIP processing unit 700.

Then, the PIP processing unit 700 processes the respective video signals from the first and second video signal processing units 400 and 600 into a main / sub picture under one control under the control of the microprocessor 200 and configures them into one screen. As shown in FIG. 2, two image signals applied based on the preset position and size of the housewife screen are converted into digital signals, the two broadcast signals are synthesized to match the size and position of the housewife screen, and converted into analog signals, and then converted into an RGB signal. 800).

Meanwhile, the R.G.B converter 800 converts the R.G.B signal, amplifies, and outputs the video signal from the PIP processing unit 700 on the monitor 900.

Next, the detailed block diagram of FIG. 2 to which the PIP processing unit 700 described above is attached will be described in detail.

As shown in the figure, the PIP processing unit 700 includes first and second A / D converters 710 and 720, first and second storage units 730 and 740, signal processing unit 750 and D / A. The conversion unit 760 is included.

In this configuration, the first and second A / D converters 710 and 720 convert one analog video signal input from the first and second video signal processor 400 and 600 into a digital video signal and perform one horizontal operation. The first and second storage units 730 and 740 are output in line units.

Then, the first and second storage units 730 and 740 temporarily store the digital image signals from the first and second A / D converters 710 and 720, respectively, and output the digital image signals to the signal processor 750.

On the other hand, the signal processing unit 750 is the main screen of the digital image signal for the main screen and the sub-screen digital image signal applied from the first, second storage unit 730, 740 under the control of the microprocessor 200 In response to the position and size of the sub-picture, the digital image signal is synthesized by one horizontal line unit and applied to the D / A converter 760 by the horizontal line unit.

Then, the D / A converter 760 converts the digital video signal obtained by synthesizing the main / sub picture from the signal processor 750 into an analog video signal and outputs the analog video signal to the RGB converter 800. 800 processes this and outputs it to the monitor 900 so that the viewer can simultaneously watch the housewife screen.

On the other hand, there are two methods of tuning and receiving a broadcast signal: an FS (Frequency Synchronizing) method and a VS (Voltage Synchronizing) method.

In the FS system, AFT (Automatic Fine Tunning) voltage is used 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 and the user selects a predetermined channel by key operation or the like, the microprocessor applies the PLL data of the selected channel to the tuner. A phase lock loop is formed in the tuner to control the oscillation frequency of the voltage controlled oscillator according to the PLL data to receive the frequency signal of the channel selected by the user.

In the VS method, the band switching voltage corresponding to the band (VHF LOW, VHF HIGH, UHF) is changed, and the tuning voltage of the channel where the broadcast signal is detected is increased by increasing the tuning voltage from the reference tuning voltage in predetermined steps. The channel tuning is performed while memorizing the serial number gradually increasing, and it can be implemented at a lower cost than the FS method.

In addition, the television provides a channel auto search method, which is performed by using a single tuner when a user operates a key of a key panel provided in the remote control or the television main body to automatically search for a channel through which a television broadcast signal is received. It is to store the information about all the channels for which the synchronization signal is detected while changing the value in the memory (EEPROM), there is a problem that it takes a considerable time to automatically search all channels.

The present invention has been made to solve the above-mentioned problems. When the user requests the automatic discovery of a channel, one tuner searches for and stores only a channel of a broadcast signal with an identification code, and the other tuner recognizes the channel. When the most accurate broadcast signal is received using the synchronization signal for the stored channel that is stored as the final channel information, to provide a channel automatic search method of a television equipped with a PIP function that enables faster and more accurate channel search. have.

1 is a schematic structural block diagram of a television having a general PIP function;

2 is a detailed block diagram of the PIP processing unit of FIG.

3 is a schematic structural block diagram of a television having a PIP function adopted in the present invention;

4 is a flowchart illustrating a channel automatic discovery process according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

100: key input unit 110: EEPROM

200: microprocessor 210: recognition code detection unit

220: synchronization signal detection unit 300: first tuner unit

400: first image signal processor 500: second tuner unit

600: second video signal processor 700: PIP processor

710: first A / D converter 720: first storage unit

730: second A / D conversion unit 740: second storage unit

750: signal processing unit 760: D / A conversion unit

800: R.G.B converter 900: monitor

The channel auto-discovery method of the present invention for achieving the above object comprises the steps of determining the input of the channel auto-discovery key, and when the channel auto-discovery key is input, recognizes from the broadcast signal received while sequentially changing the channel in one tuner If a code is detected, storing the corresponding channel, and if another tuner detects a synchronization signal with respect to the channel where the recognition code is detected, and uses the same, the final channel information is received when the most accurate broadcast signal is received in the same channel. Characterized in that the step of storing as.

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

The television employed in the embodiment of the present invention is a television having the conventional general PIP function shown in Fig. 1, which includes means for decoding information added in a broadcast signal and detecting the most accurate synchronization signal in the same channel. It further comprises a synchronizing signal detecting and comparing means for outputting.

That is, as shown in FIG. 3, a key input unit 100 having a plurality of keys for performing an operation of a television and outputting a key signal corresponding to a user's key operation, and a key signal from the key input unit 100. The microprocessor 200 controls the overall operation of the television by selectively controlling the first and second tuner units 300 and 500, the first and second image signal processing units 400 and 600, and the PIP processing unit 700 according to the present invention. And first and second tuner units 300 and 500 for outputting the broadcast signals received by tuning to channels corresponding to the control of the microprocessor 200 to the first and second image signal processing units 400 and 6, respectively. The first and second video signal processing units 400 and 600 respectively separating and outputting the video signals from the broadcast signals from the first and second tuners 300 and 500 and the first and second devices under the control of the microprocessor 200. Each video signal from the video signal processing units 400 and 600 is processed into a main / sub picture. PIP processing unit 700 configured to output a single screen, RGB conversion unit 800 and monitor for RGB conversion, amplification processing and output in order to display the video signal from the PIP processing unit 700 on the monitor 900 ( In the television having a PIP function comprising a 900, KBPS decoder 210 for detecting and decoding information added to the video signal output from the first video signal processing unit 400, and the second The image signal processor 400 further includes a synchronization signal detector 220 that detects a synchronization signal from the image signal output.

Although not shown, the apparatus includes a voice signal processor and a speaker for detecting a voice signal from the broadcast signal output from the first video signal processor 400 and outputting the voice signal to a speaker through a predetermined process.

Next, a description will be given in detail with reference to the flowchart of FIG. 4 attached to a channel automatic search procedure in a television having a PIP function according to a preferred embodiment of the present invention in a television having the above-described configuration.

When the microprocessor 200 recognizes that the user inputs the channel auto search key by the key input unit 100, the microprocessor 200 controls the first tuner unit 300 and the second tuner unit 500 to perform the channel auto search function. Otherwise, performs another television function (S100, S110).

In the automatic channel search, first, the channel tuner 300 starts the channel search by controlling the first tuner unit 300. Then, the first tuner unit 300 tunes to a channel required by the microprocessor 300, receives a broadcast signal, outputs the broadcast signal to the first image signal processor 400, and processes the image processed by the first image signal processor 400. The signal is output to the KBPS decoder 210. Then, the KBPS decoder 210 detects, decodes, and outputs the information added to the vertical blanking section of the video signal and outputs it to the microprocessor 200.

When the recognition code is detected from the input information, the microprocessor 200 regards the channel as a channel to which a broadcast signal is transmitted and stores the channel information in the internal memory. If the recognition code is not detected, the microprocessor 200 continues the channel search by increasing or decreasing the channel. , Channel search is performed for all channels (S120).

Meanwhile, the microprocessor 200 tunes the second tuner unit 500 to the channel where the recognition code is detected in order to further search the channel in which the recognition code is stored, and is received by the second tuner unit 500. The video signal in the broadcast signal is supplied to the sync signal detector 220 through the second video signal processor 200.

The synchronization signal detector 220 detects the synchronization signal from the received broadcast signal and outputs the synchronization signal to the microprocessor 200. The microprocessor 200 determines whether the synchronization signal is correct, and if it is correct, finalizes the current channel information (tuning voltage). As the channel information, the channel search is precisely performed by adding or subtracting the preset voltage within the same channel range and outputting it to the second tuner 500 again (S130).

While the invention has been shown and described with respect to particular embodiments, it will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the invention as set forth in the claims. Anyone can see it easily.

As described above, according to the present invention, when a user requests automatic discovery of a channel receiving a television broadcast signal, one tuner searches for and stores only a channel of a broadcast signal having a recognition code, and the other tuner stores the recognition code. When the most accurate broadcast signal is received using the synchronization signal for the channel, the channel information is stored as final channel information, thereby enabling faster and more accurate channel search, thereby increasing user convenience.

Claims (1)

It includes two tuners, and determining the input of the channel auto search key, and when the channel auto search key is input, changing the channel in one tuner sequentially and storing the corresponding channel when the recognition code is detected in the received broadcast signal And detecting, by the other tuner, the synchronization signal with respect to the channel where the recognition code is detected, and storing it as final channel information when the most accurate broadcast signal is received in the same channel using the same tuner. A channel automatic search method for a television having a PIP function.