KR19990033457A - Automatic channel search method of composite broadcast receiver - Google Patents

Abstract

The present invention provides a composite broadcast receiver capable of detecting all terrestrial broadcasts, CATV broadcasts, and satellite broadcasts using a single channel auto search key. The present invention relates to a channel automatic search method, wherein when the receiver is powered on, each channel information for the satellite broadcast is automatically stored, and a key signal for automatically searching for a plurality of valid channels included in each broadcast mode is input. A first step of sequentially tuning each channel of the receiver; A second step of checking whether the tuned channel is an effective channel included in the pre-stored satellite broadcasting channel information; If the tuned channel is an effective channel of the satellite broadcast, the next channel of the receiver is tuned to repeat the process after the second step. As a result of the check, the tuned channel is a valid channel. If not, switching the operation of the receiver to the terrestrial broadcasting mode, and then determining whether the tuned channel is an effective channel of the terrestrial broadcasting mode; A fourth step of storing the tuned channel number if the tuned channel is an effective channel and tuning the next channel of the receiver to repeat the process after the second step as a result of the determination of the third step; A fifth step of determining whether the tuned channel is an effective channel of the cable broadcasting mode after switching the operation of the receiver to a cable broadcasting mode if the tuned channel is not an effective channel as a result of the determination in the third step; step; As a result of the determination of the fifth step, when the tuned channel is an effective channel, the tuned channel number is stored, and the operation of the receiver is tuned to the next channel of the receiver to repeat the process after the second step. A sixth step; If the tuned channel is not an effective channel as a result of the determination in the fifth step, the next channel of the receiver is tuned to repeat the process after the second step until the automatic search process for each channel is completed. It includes a seventh step.

Description

Automatic channel search method of composite broadcast receiver

The present invention relates to a composite broadcast receiver, and more particularly, to a channel broadcast of a composite broadcast receiver suitable for automatically searching for an effective channel for each mode in a composite broadcast receiver capable of receiving satellite broadcast signals, CATV broadcast signals, and terrestrial broadcast signals. It is about a search method.

Recently, the broadcast method using satellites, which is rapidly expanding its 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 several tens to hundreds of kilometers from 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, which is a high frequency RF signal. Is converted into an IF (intermediate frequency) signal in the hundreds to thousands of MHz bands (for example, 950 MHz to 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. When 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, it would be necessary to have a satellite tuner and a cable tuner separately.

Therefore, in order to accommodate various types of broadcasts as described above, various types of internal or external tuners may be provided, or two types of broadcasts may be provided in separate signal processing paths (that is, satellite broadcast signal processing paths and cable broadcasts). It may be considered that the receiver employs an integrated complex tuner for processing through a signal processing path, but this causes not only a problem of unnecessarily increasing hardware of the receiver itself, but also an excessive increase in the cost of the receiver. Problems arise.

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.

On the other hand, each conventional broadcast receiver is provided with a channel automatic search function that detects only a channel to which a broadcast signal is input by determining whether there is an actual broadcast signal for each channel provided to the receiver.

Therefore, such a channel automatic search function is also provided in a composite broadcast receiver capable of receiving each broadcast mode as described above. When a user performs a channel automatic search through key manipulation in a conventional composite broadcast receiver, The channel will be searched automatically only for the currently running mode.

That is, when the user inputs the channel auto search key signal while the composite broadcast receiver is operating in the CATV broadcast mode and is receiving a specific channel of the CATV broadcast signal, the CATV broadcast is received among the broadcast signals received by the composite broadcast receiver. Only the search for each channel of is performed.

Therefore, when the channel automatic search process for CATV broadcasting is completed, the user should switch the receiver operation to the satellite broadcasting mode and perform channel automatic search again, and if the channel automatic search process for the satellite broadcasting mode is finished, In addition, the user must switch the operation of the receiver to the terrestrial broadcasting mode and repeat the channel automatic search process.

As a result, in order to perform channel automatic search for each broadcasting mode, there is an inconvenience in that the user has to switch the operation of the receiver by hand operation each time, that is, to switch modes.

Accordingly, the present invention has been made in view of the above, and when the channel automatic search key signal is input from the composite broadcast receiver, channel search for each broadcast (satellite broadcast, CATV broadcast, terrestrial broadcast) is automatically performed at once. An object of the present invention is to provide a channel automatic search method of a composite broadcast receiver.

In order to achieve the above object, the present invention provides a broadcast signal processing path for processing a terrestrial broadcast mode channel and a cable broadcast mode channel tuned through a composite tuner, and a broadcast signal processing path for processing a satellite broadcast channel tuned through the composite tuner. A method for automatically searching for an effective channel in a composite broadcasting receiver including: When the receiver is powered on, each channel information about the satellite broadcasting is automatically stored, and a plurality of valid channels included in each broadcasting mode. A first step of sequentially tuning each channel of the receiver when a key signal for automatically searching for a channel is input; A second step of checking whether the tuned channel is an effective channel included in the pre-stored satellite broadcasting channel information; If the tuned channel is an effective channel of the satellite broadcast, the next channel of the receiver is tuned to repeat the process after the second step. As a result of the check, the tuned channel is a valid channel. If not, switching the operation of the receiver to the terrestrial broadcasting mode, and then determining whether the tuned channel is an effective channel of the terrestrial broadcasting mode; A fourth step of storing the tuned channel number if the tuned channel is an effective channel and tuning the next channel of the receiver to repeat the process after the second step as a result of the determination of the third step; A fifth step of determining whether the tuned channel is an effective channel of the cable broadcasting mode after switching the operation of the receiver to a cable broadcasting mode if the tuned channel is not an effective channel as a result of the determination in the third step; step; As a result of the determination of the fifth step, when the tuned channel is an effective channel, the tuned channel number is stored, and the operation of the receiver is tuned to the next channel of the receiver to repeat the process after the second step. A sixth step; If the tuned channel is not an effective channel as a result of the determination in the fifth step, the next channel of the receiver is tuned to repeat the process after the second step until the automatic search process for each channel is completed. It provides a channel automatic search method of a composite broadcast receiver comprising a seventh step.

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

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

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

102: tuner block 104: MPEG decoding block

106: video encoding block 108: video processing block

110: sync extraction block 112: control block

114: memory block 116: OSD processing block

118: mixer 120: switching block

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 automatic search method of a composite broadcast receiver according to a preferred embodiment of the present invention. The composite reception system includes a tuner block 102, an MPEG decoding block 104, Video encoding block 106, video processing block 108, sync extraction block 110, control block 112, memory block 114, OSD processing block 116, mixer 118 and switching block 120 It includes.

Referring to FIG. 1, the tuner block 102 is based on a tuning control signal provided from a control block 112 to be described later via a line L11, and a broadcast signal receiver (i.e., a satellite reception antenna and a terrestrial reception antenna) is omitted. Tunes the broadcast channel selected by the user from the broadcast signal received through a cable, and the like, and demodulates the tuned broadcast channel signal into an original signal before transmission. When the satellite broadcast signal is tuned, the demodulated satellite channel signal is The demodulated terrestrial or cable broadcast channel signal is provided to the video processing block 108 via the line L14 when the terrestrial broadcast signal or the cable broadcast signal is tuned through the line L12.

That is, the tuner block 102 is composed of a satellite tuner, a terrestrial broadcast, and a CATV broadcast signal provided through an antenna or transmission line (not shown) and a composite tuner capable of mode-receiving and tuning a CATV broadcast signal.

In the MPEG decoder block 104, the compressed and encoded video signal of the tuned satellite broadcast channel provided by the tuner block 102 through the line L12 is compressed in consideration of the spatiotemporal and spatial correlation of the video signal. The encoded video signal is restored to the original signal before encoding using a decoding technique such as variable length decoding, inverse DCT, inverse quantization, and motion compensation, and the recovered digital video signal is transferred to the next video encoding block 106. Is provided.

Next, the video encoding block 106 converts the tuned digital video signal provided in the MPEG decoding block 104 described above into an NTSC or PAL analog video signal and then to the contact b of the switching block 114 via the line L13. to provide.

In addition, the video processing block 108 processes the tuned analog video signal (i.e., terrestrial broadcast channel signal or cable broadcast channel signal) provided by the tuner block 102 via line L14, for example, level amplification, Various signal processing such as noise cancellation and gain control is performed and provided to the contact point c of the sync extraction block 110 and the switching block 114 through the line L15.

Meanwhile, the sync extraction block 110 extracts a sync signal included in the tuned channel signal provided by the video processing block 108, that is, a horizontal sync signal, through the line L15, and the horizontal sync signal extracted in this way is a line. It is provided to the control block 110 through L16. In this case, the horizontal synchronization signal extracted here is used to determine whether the tuned broadcast signal is an effective channel. The existence of the horizontal synchronization signal is checked for each channel so that only a channel with good viewing can be automatically tuned. It will be performed for a predetermined time.

On the other hand, the control block 112 is, for example, a microprocessor that performs overall operation control of the receiving system, and when the user broadcast channel selection signal (ie, operation signal) is input from the outside, the corresponding tuning control signal Is generated and provided to the above-described tuning block 102 through the line L11, and based on the horizontal synchronization signal provided from the sync extraction block 110 through the line L16 in the automatic tuning mode of the specific broadcast mode (i.e., And a channel carrying a viewable broadcast signal) and stores the corresponding channel number in the area A of the memory block 114 when the channel being tuned is an effective channel. That is, in the area A of the memory block 114, number information of valid channels automatically tuned for each broadcasting mode is stored.

In addition, the control block 112, based on a user operation signal from the outside, the switching control signal on the line L17 for switching the output of the broadcast signal corresponding to the broadcast mode currently being viewed or the broadcast mode that the user wants to switch To the switching block 120 to be described later.

In addition, various areas of OSD data, for example, a message for guiding a broadcast mode and a guide message for automatic tuning, are stored in the area B of the memory block 114. In the control block 112, a monitor not shown is shown. When a message is required to be sent, for example, when a message is sent for guiding the broadcast mode, a corresponding message is fetched from the area B of the memory block 114 and provided to the OSD processing block 116 through the line L18.

The OSD processing block 116 then uses the OSD based on self-generated vertical and horizontal sync signals for positioning the OSD message to be sent when the message data is provided from the control block 112 described above via line L18. Configure screen data, wherein the configured OSD screen data is provided to mixer 118 via line L19. At this time, the generated vertical and horizontal synchronization signals are signals for positioning the OSD data in a predetermined fixed position (for example, a portion of the upper side of the screen, a portion of the lower side of the screen, etc.) or the OSD at a variable position according to the user's request. It may be a signal for locating data.

Thus, mixer 118 properly mixes the image data on line L15 with the OSD screen data via line L20 when OSD screen data including messages (ie, guidance message, inquiry message, etc.) is provided on line L19. The contact c of the switching block 120 is provided. Also, the mixer 118 bypasses the image data on the line L15 to the contact c of the switching block 120 as it is when there is no OSD screen data on the line L19.

Meanwhile, the switching block 120 selectively selects a video signal output (or a mixed video signal mixed with OSD data) of the tuned general broadcast channel (ie, terrestrial broadcast or cable broadcast) and a video signal output of the tuned satellite broadcast channel. Based on the switching, i.e., the switching control signal provided from the above-described control block 112 via the line L17, when the satellite broadcasting mode is selected by the user, the video of the satellite broadcasting channel provided through the line L13 by connecting the contact ab A video signal (or a mixed video signal mixed with OSD data) provided through the line L20 by providing a signal to a display side (not shown) and connecting the contact ac when a normal broadcast (terrestrial broadcast or cable broadcast) mode is selected by the user. ) To the display side, not shown.

FIG. 2 is a flowchart illustrating an automatic channel search process of a composite broadcast receiver according to an exemplary embodiment of the present invention. Referring to FIG. 2, when the power of the receiver is turned on, each of the above-described operations is performed by the user. Broadcast mode, i.e., a satellite broadcast mode, a CATV broadcast mode, or a broadcast mode selected from one of the terrestrial broadcast modes, and then a general viewing mode in which a broadcast signal for a specific channel is displayed on a monitor (not shown) through a predetermined signal processing process. In this case, information on each channel of the satellite broadcast is automatically stored in the area A of the memory block 114 by the control block 112 (step 201).

That is, when the power of the composite broadcast receiver is turned on, the control block 112 extracts each channel information of the satellite broadcast inserted in the bit stream of the satellite signal regardless of the operation mode of the receiver and stores the channel information of the satellite broadcast in the memory block 114. .

In the normal viewing mode in which the channel information of the satellite broadcast is pre-stored through the above-described process (step 201), if a channel auto search key signal for each broadcast mode of the composite broadcast receiver is input by the user (step 203). ), The control block 112 reads the guide message information stored in the area B of the memory block 114 and displays a certain type of guide message (for example, 'channel auto searching') through the OSD processing block. (Step 205).

Subsequently, the control block 112 generates a tuning control signal to the tuner block 102 to switch to the first channel of each of the 158 channels provided to the receiver (step 207), and then tunes by the current tuner block 102. It is checked if the channel is included in the satellite channel information stored in the area A of the memory block 114 (step 209).

In other words, it is determined whether the currently tuned channel is a satellite broadcast channel. As a result of the determination, the next channel is tuned by generating a control signal to the tuner block 102 again to increase the channel in the case of the satellite broadcast channel. After (step 213), the above-described step 211 is repeated.

On the other hand, when the determination result in step 213 described above, when the channel currently tuned is not a satellite broadcast channel, the control block 112 again generates a mode switching control signal to the tuner block 102 terrestrial wave operation of the receiver The broadcast mode is switched to the broadcast mode (step 215). In detail, a typical composite broadcast receiver uses a frequency band of 1 kHz, so that there are up to 158 channels, and terrestrial wave and CATV are present in any one of the 158 channels. It is unknown whether a broadcast signal and a satellite broadcast signal are received.

Therefore, in step 215, the first mode is switched to a mode in which the terrestrial broadcast signal can be tuned, and then, whether or not the terrestrial broadcast signal is received in the corresponding channel is detected (step 217).

Meanwhile, in the effective channel determination method, the horizontal synchronization signal inserted into the broadcast signal of the channel tuned in step 207 or step 213 is extracted through a sync extraction block and counted, and the counted value is the terrestrial broadcast. When the number of horizontal synchronization signals is equal to, the corresponding channel is determined as a channel for receiving terrestrial broadcasting.

If, as a result of the above-described determination in step 217, if it is not an effective channel, that is, not a terrestrial broadcast channel, the control block 112 again generates a mode switching signal to the tuner block 102, thereby operating the receiver. Is switched to the CATV tuning mode (step 219).

Accordingly, the tuner block 102 generates an oscillation frequency for tuning the broadcast signal of the CATV to tune the corresponding channel to the CATV channel, and detects the horizontal synchronization signal from the tuned channel signal in the same manner as the above-described process. It is determined whether the channel is an effective channel of CATV (step 221).

As a result of the determination, if the tuned broadcast channel is an effective channel for CATV, after storing the channel number of the corresponding channel in the area A of the memory block 114 of FIG. 1 (step 223), the currently tuned channel is stored. It is checked whether or not the channel search process is terminated by checking whether the maximum channel that can be received through the tuner block 102, that is, the last channel (step 225), on the contrary, if the determination result in the above-described step 221, If the channel is not an effective channel of the CATV, it is checked whether the channel search process as described above is terminated without storing channel information for the channel (step 225).

On the other hand, when the channel search process is not finished as a result of the check in step 225 described above, the tuner block 102 generates a tuning control signal to increase the channel number currently tuned to tune the next channel (step 213, the above-described step 211 is repeatedly performed to perform the tuner block 102 on the effective channel determination process for each mode for the next channel.

And, the effective channel for each mode detected through the above-described process is stored in the area A of the memory block 114. When the effective channel detection process for each channel is detected in step 225, the control is performed. Block 112 turns off the currently displayed guidance message via step 205 described above and then switches the operation of the receiver to the normal viewing mode of initial step 201 (step 227).

As a result, each channel is sequentially tuned to determine whether it is a satellite broadcast channel, and then automatically switched to terrestrial broadcast and CATV broadcast modes to automatically search for each channel.

As described above, according to the present invention, a channel broadcast for each broadcast mode can be automatically performed with a single key operation without switching between broadcast modes in a composite broadcast receiver capable of simultaneously receiving terrestrial broadcasts, CATV broadcasts, and satellite broadcasts. There is an effect, and accordingly there is an effect that can greatly enhance the user convenience.

Claims (5)

An effective channel is received in a composite broadcasting receiver having a broadcast signal processing path for processing a terrestrial broadcast mode channel and a cable broadcast mode channel tuned through a composite tuner and a broadcast signal processing path for processing a satellite broadcast channel tuned through the composite tuner. In the automatic search method, When the power of the receiver is turned on, each channel information of the satellite broadcasting is automatically stored, and when a key signal for automatically searching for a plurality of valid channels included in each broadcasting mode is input, each channel of the receiver is stored. A first step of sequentially tuning; A second step of checking whether the tuned channel is an effective channel included in the pre-stored satellite broadcasting channel information; If the tuned channel is an effective channel of the satellite broadcast, the next channel of the receiver is tuned to repeat the process after the second step. As a result of the check, the tuned channel is a valid channel. If not, switching the operation of the receiver to the terrestrial broadcasting mode, and then determining whether the tuned channel is an effective channel of the terrestrial broadcasting mode; A fourth step of storing the tuned channel number if the tuned channel is an effective channel and tuning the next channel of the receiver to repeat the process after the second step as a result of the determination of the third step; A fifth step of determining whether the tuned channel is an effective channel of the cable broadcasting mode after switching the operation of the receiver to a cable broadcasting mode if the tuned channel is not an effective channel as a result of the determination in the third step; step; As a result of the determination of the fifth step, when the tuned channel is an effective channel, the tuned channel number is stored, and the operation of the receiver is tuned to the next channel of the receiver to repeat the process after the second step. A sixth step; If the tuned channel is not an effective channel as a result of the determination in the fifth step, the next channel of the receiver is tuned to repeat the process after the second step until the automatic search process for each channel is completed. A channel automatic search method of a composite broadcast receiver comprising a seventh step. The method of claim 1, wherein the effective channel determination of the tuned channel is performed by extracting and determining a horizontal synchronization signal with respect to the broadcast signal of the tuned channel. The channel of claim 1, wherein the first step further comprises: when a key signal for automatically searching for the effective channel is input, displaying a predetermined guide message informing that the valid channel is being searched. Auto detect method. The method of claim 3, wherein the guide message is automatically turned off when the automatic search process for each channel is completed. 4. The method of claim 3, wherein the guide message is displayed on the monitor in the form of an OSD.