KR19990052317A - Channel Search Control Method for Composite Broadcast Receiver - Google Patents

Abstract

The present invention relates to a channel search control method of a composite broadcast receiver that can automatically prevent output of an audio signal by automatically blocking the output of an audio signal when a channel broadcast process for a CATV channel is performed in the composite broadcast receiver. To this end, according to the present invention, if a key signal for searching for an effective channel to which an actual broadcast signal is input among a plurality of channels assigned to the cable broadcast is input during the normal viewing mode of the composite broadcast receiver, the composite broadcast is received. A first step of switching an overall operation of a receiver to the cable broadcasting mode; A second step of blocking an output of an audio signal provided to the composite broadcast receiver; A third step of sequentially tuning the plurality of cable broadcast channels to detect the effective channel and storing the detected valid channel information; When the effective channel search process is finished, a fourth step of releasing the output blocking of the audio signal and switching the operation of the composite broadcast receiver to the normal viewing mode.

Description

Channel Search Control Method for Composite Broadcast Receiver

The present invention relates to a composite broadcast receiver, and more particularly, to a channel search control method of a composite broadcast receiver suitable for controlling an audio signal output during automatic channel search for a CATV broadcast received by the composite broadcast receiver.

In recent years, the broadcast method using satellites, which is rapidly expanding in use, is a method of providing a broadcast signal to a wider area by using a satellite (communication satellite) located at an altitude of about tens to hundreds of kilos on the surface of the earth. In this satellite broadcasting system, for example, an old band RF signal having a frequency band of 11.7 GHz to 12.0 GHz is used.

To this end, the antenna for satellite broadcasting reception is provided with a low noise blockdown converter for converting a radio frequency (RF) signal of a very high frequency into an intermediate frequency (IF) signal, and the low noise converter converts an ultra high frequency RF signal. It converts into an IF (intermediate frequency) signal in the hundreds to thousands of MHz bands (for example, 950 MHz-2050 MHz) that can be received by a satellite broadcasting receiver (receiver).

Therefore, in the satellite broadcasting tuner provided in the satellite broadcasting receiver (receiver), the user selects and tunes a channel selected by inputting an IF signal received through a low noise converter. The satellite broadcasting receiver maximizes channel utilization, video and audio signals. Along with the improvement of quality and the ease of transmitting additional digital service data, the significant improvement of the user interface is a big advantage.

In recent years, as well as satellite broadcasting, CATV broadcasting using cable has been rapidly spreading. If a subscriber (ie, one receiver) wants to receive all of these broadcasting signals, the frequency band of each broadcasting is used. Because of this difference, a satellite tuner, a cable tuner, and a terrestrial tuner will all need to be equipped separately.

Accordingly, in order to accommodate various types of broadcasts as described above, various types of internal or external tuners may be provided, or each type of broadcast may have a separate signal processing path (that is, a satellite broadcast signal processing path and a cable broadcast signal). It may be considered that the receiver employs an integrated complex tuner for processing through a processing path, but this causes not only an unnecessary increase in hardware of the receiver itself, but also an excessive increase in the cost of the receiver. Is caused.

On the other hand, in view of the above, a complex tuner capable of simultaneously receiving a satellite broadcast signal, a cable broadcast signal, and a terrestrial broadcast signal through a single tuning path has been developed. It is also being developed.

The composite broadcast receiver controls the passband of the received signal and tunes the bandpassed signal based on the user selection signal when the satellite broadcast signal or the cable broadcast signal is received at the input side, and in accordance with the tuned signal and the user selection. Tuning the corresponding channel of the desired broadcast signal by mixing the oscillating frequencies generated, and the tuned signals are provided to corresponding demodulators through separate signal processing paths (BS path, DSR path, CATV path) respectively provided It is.

Meanwhile, in a composite broadcast receiver capable of accommodating a general satellite broadcast signal and a cable broadcast signal, an automatic channel search process is performed to search for an effective channel to which an actual broadcast signal is input among a plurality of broadcast channels. Since additional information such as channel information and program information for each channel is inserted into the broadcast signal and transmitted, this channel search process is unnecessary.

Therefore, the automatic channel search process in the composite broadcast receiver is performed only for the CATV channel, which will be described in detail. First, the PLL (phase locked) of each channel allocated to the CATV broadcast among the plurality of channels assigned to the composite broadcast receiver will be described. After sequentially tuning using a loop) value, a synchronization signal is extracted from the tuned signal to determine whether to broadcast on a corresponding channel.

During the channel search process, the A / V (audio / video) of the tuned channel is output through the monitor and the speaker. The audio signal output during the channel search is a noise that has no meaning to the user. It is only. In particular, when tuning a channel to which a broadcast signal is not input, there is a problem in that unpleasant noise is continuously output through a speaker.

Accordingly, the present invention has been made in view of the foregoing, and when an automatic channel search process for CATV broadcasting is performed in the composite broadcast receiver, a channel of the composite broadcast receiver which can automatically temporarily block an audio signal output from each channel. Its purpose is to provide a search control method.

In order to achieve the above object, the present invention provides a broadcast signal processing path for processing a plurality of terrestrial broadcast channels and cable broadcast channels tuned through a composite tuner and a broadcast signal for processing a plurality of satellite broadcast channels tuned through the composite tuner. A method for controlling an automatic search process for a plurality of cable broadcast channels in a composite broadcast receiver having a processing path, wherein the actual broadcast among the plurality of channels assigned to the cable broadcast is performed during the normal viewing mode of the composite broadcast receiver. A first step of switching the overall operation of the composite broadcast receiver to the cable broadcast mode when a key signal for searching for an effective channel to which a signal is input is input; A second step of blocking an output of an audio signal provided to the composite broadcast receiver; A third step of sequentially tuning the plurality of cable broadcast channels to detect the effective channel and storing the detected valid channel information; When the effective channel search process is finished, the method for controlling the channel search of the composite broadcast receiver comprising the step of canceling the output block for the audio signal, and switching the operation of the composite broadcast receiver to the normal viewing mode. do.

1 is a block diagram of a composite broadcast receiver suitable for applying a channel search control method of a composite broadcast receiver according to an embodiment of the present invention;

2 is a flowchart illustrating a channel search control process of a composite broadcast receiver according to an embodiment of the present invention.

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

105: key input unit 110: control unit

115: tuner and demodulator 120: MPEG decoder

125: A / V signal processor 130: NTSC processor

135 synchronization detection unit 140 memory unit

145: audio control unit 150: switching unit

The above and other objects and various advantages of the present invention will become more apparent from the preferred embodiments of the present invention described below with reference to the accompanying drawings.

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

1 is a block diagram of a composite broadcast receiver suitable for applying a channel search control method of a composite broadcast receiver according to an exemplary embodiment of the present invention, and includes a key input unit 105, a controller 110, a tuner, and a demodulator 115. ), An MPEG decoder 120, an A / V signal processor 125, an NTSC processor 130, a synchronization detector 135, a memory 140, an audio controller 145, and a switching unit 150.

The key input unit 105 is composed of key metrics on a remote controller or its own panel to generate a corresponding key signal by a user's operation and provide the corresponding key signal to the controller 110, and the controller 110 controls overall operation of the receiving system. When the microprocessor performs the user broadcast channel selection signal (that is, the operation signal) from the key input unit 105, a corresponding tuning control signal is generated and provided to the tuner and demodulator 115 to be described later.

The tuner and demodulator 115 is a broadcast channel selected by a user in a broadcast signal received through a broadcast signal receiver (i.e., antenna, cable, etc.), not shown, based on a tuning control signal provided from the controller 110. And demodulate the tuned broadcast channel signal into the original signal before transmission. When the satellite broadcast signal is tuned, the demodulated satellite broadcast channel signal is provided to the MPEG decoder 120, and the cable broadcast signal or the terrestrial broadcast signal is When tuned, the demodulated broadcast channel signal is provided to the NTSC processor 130.

That is, the tuner and demodulator 115 is composed of a composite tuner capable of receiving and tuning all satellite broadcast signals, CATV broadcast signals, and terrestrial broadcast signals provided through an antenna or transmission path, not shown.

The MPEG decoder 120 restores the compressed coded video signal and the audio signal of the tuned satellite broadcast channel provided by the tuner and the demodulator 115 to the original signal before encoding, and the A / V signal processing unit ( 125).

Next, the A / V signal processing unit 125 converts the tuned digital video signal provided by the MPEG decoder 120 described above into an NTSC or PAL analog video signal, and also converts the digital audio signal into an analog audio signal, which will be described later. Through the switching unit 150 is output through the monitor and the speaker, respectively.

Meanwhile, the NTSC processor 130 processes the tuned analog video and audio signals (cable broadcast signals) provided by the tuner and demodulator 115, for example, various signals such as level amplification, noise cancellation, and gain control. The video signal is provided to the switching unit 150 through a line L11, and the audio signal is provided to the audio controller 145 through a line L12.

The synchronization detector 135 extracts the synchronization signal from the CATV video signal output from the NTSC processor 130 and provides the synchronization signal to the controller 110 to detect an effective channel for the CATV broadcast, and the audio controller 145 During the CATV automatic channel search, the control of the control unit 110 blocks the output of the CATV audio signal output from the NTSC processing unit 130.

The memory unit 140 receives the effective channel information on the CATV broadcast detected through the synchronization detector 135 from the controller 110 and stores the effective channel information in a predetermined region. The output of the audio signal and the video and audio signal of the satellite broadcasting channel are selectively switched based on the switching control signal provided from the above-described control unit 110 and output to the monitor and the speaker, not shown.

2 is a flowchart illustrating a channel search control process of a composite broadcast receiver according to an exemplary embodiment of the present invention, which will be described in detail with reference to the accompanying drawings.

During the normal viewing mode in which the operation of the composite broadcast receiver configured as described above tunes a broadcast signal of a specific channel selected by the user and displays the signal through a predetermined signal processing process, or in a standby mode for performing a specific command input by the user (step 201), when the automatic channel search key signal for CATV broadcasting is input through the key input unit 105 (step 203), the controller 110 generates a mode switching signal to the tuner and demodulator 115 and the switching unit 150. The overall operation of the composite broadcast receiver is switched to the CATV broadcast mode (step 205).

In addition, after generating an output cutoff signal to the audio controller 145 again to block the output of the audio signal to be provided from the NTSC processor 130 (step 207), tuning the CATV channel to the tuner and the demodulator 115. A tuning control signal is generated to sequentially tune all channels for the CATV broadcast allocated to the composite broadcast receiver (step 209).

At this time, the synchronization detector 135 extracts a synchronization signal from each channel signal of the CATV output from the NTSC processor 130 and provides the synchronization signal to the controller 110, and the controller 110 synchronizes the synchronization signal provided from the synchronization detector 135. It is determined whether the corresponding CATV channel is an effective channel according to the presence or absence of a signal. Each valid channel information detected through this process is stored in a predetermined area of the memory unit 140 (step 211).

Meanwhile, the CATV channel signal output from the tuner and demodulator 115 undergoes a predetermined signal processing process through the NTSC processor 130 while the automatic search process for a plurality of CATV broadcast channels is performed through the above-described process. Then, the video signal and the audio signal are separated and provided to the switching unit 150 and the audio control unit 145, respectively.

In addition, the switching unit 150 displays the video signal of the CATV channel provided from the NTSC processing unit 130 on a monitor (not shown). In this case, the audio control unit 145 receives the control signal from the control unit 110 at step 207. The output of the audio signal provided from the NTSC processor 130 is cut off based on the generated audio output cutoff signal.

That is, while the above-described CATV automatic channel searching process is performed, the video signal of each tuned channel is displayed on the monitor, but the audio signal is muted by the output cutoff control signal of the audio controller 145. do.

On the other hand, when the automatic search process for the CATV channel allocated to the composite broadcast receiver through the above-described process (step 213), the control unit 110 generates an output block release signal to the audio control unit 145 again. The operation of the audio control unit 145 is switched to a normal state, and a mode switching control signal is generated at the tuner, the demodulator 115 and the switching unit 150 to describe the overall operation of the composite broadcast receiver. Switch to the normal viewing mode or the standby mode of (step 217).

As a result, when the automatic channel search process for the CATV is performed, the controller 110 automatically cuts off the audio signal for each tuned channel, and when the automatic channel search process ends, the output of the audio signal is returned to its normal state. Will be converted to.

As described above, according to the present invention, when the automatic search process for the CATV channel is performed in the composite broadcast receiver, noise generated in the automatic channel search process can be prevented by automatically blocking the output of the audio signal.

Claims (1)

In a composite broadcast receiver having a broadcast signal processing path for processing a plurality of terrestrial broadcast channels and cable broadcast channels tuned through a composite tuner and a broadcast signal processing path for processing a plurality of satellite broadcast channels tuned through the composite tuner. In the method for controlling the automatic search process for a plurality of cable broadcasting channels, During the normal viewing mode of the composite broadcast receiver, if a key signal for searching for an effective channel to which an actual broadcast signal is input is input, the overall operation of the composite broadcast receiver is performed. A first step of switching to a mode; A second step of blocking an output of an audio signal provided to the composite broadcast receiver; A third step of sequentially tuning the plurality of cable broadcast channels to detect the effective channel and storing the detected valid channel information; And terminating the output block of the audio signal and switching the operation of the composite broadcast receiver to the normal viewing mode when the effective channel search process is finished.