JP2008035316A - Digital broadcast receiving apparatus and digital broadcast receiving method - Google Patents

Abstract

Digital broadcast receiving apparatus and digital which can eliminate the trouble of searching for a viewable channel by performing a full channel scan manually every time viewing is performed, and can automatically cope with a change in reception status accompanying movement between regions Provide a broadcast receiving method.
A digital broadcast receiving apparatus is located by scanning all frequency bands where a receivable broadcast wave may exist or a relatively wide frequency band by cooperation of a system controller and a tuner unit. Scanning operation in full scan mode that detects broadcast waves including broadcast signals that can be viewed at the current location, and broadcasts that can be viewed at the current location by scanning a relatively narrow frequency band that is part of the entire frequency band. And a scanning operation in a local scan mode for detecting a broadcast wave including the above signal.
[Selection] Figure 1

Description

  The present invention relates to a digital broadcast receiving apparatus and a digital broadcast receiving method that are configured to be movable like a digital broadcast receiving apparatus provided in a mobile phone.

In recent years, a digital broadcast receiving apparatus configured to be movable like a digital broadcast receiving apparatus provided in a mobile phone is becoming popular as a so-called “one segment”.
In such a digital broadcast receiving apparatus, the channel to be received (the frequency of the broadcast wave) changes as it moves between regions. For this reason, in order to perform optimal reception at the current location, it is necessary to scan and detect receivable broadcast waves in advance.

  In order to meet such a need, the tuning data is output from the control unit, the broadcast wave is sequentially scanned by the tuner unit, and information on the radio wave reception quality of each broadcast wave received at that time is obtained from the baseband processing unit. A technique has been proposed in which a plurality of pieces of information on the radio wave reception quality are arranged and displayed in advance on a display unit, thereby eliminating the need to search for a viewable channel for viewing.

  In this proposal, when the channel scan button provided in the keyboard of the main body configured as a mobile phone is pressed, the corresponding broadcast wave is selected sequentially from the lower channel (low channel number), and the received signal of the broadcast wave is selected. The RSSI information corresponding to the level is output from the baseband processing unit, and the output information is sequentially stored in the memory together with the channel number. Then, the channel number, broadcasting station name, and RSSI information are read from each storage area of the memory, and a plurality of the channel numbers and broadcasting station names are displayed side by side on the display.

Based on this display, when a desired channel (channel number or broadcast station name) is selected from the keyboard, tuning in the tuner unit is executed, and the radio wave of the broadcast station desired to be viewed is selected. The signal of the selected broadcasting station is displayed on the display unit via the baseband processing unit, and the channel number or broadcasting station name, RSSI information, C / N information, and image information are displayed as necessary. (See Patent Document 1).
JP 2005-328246 A (paragraph 0036 to paragraph 0044, FIG. 1)

In the digital broadcast receiving apparatus (portable device) proposed in Patent Document 1 described above, manual full channel scanning needs to be performed as required. In addition, it cannot automatically respond to changes in reception conditions accompanying movement between regions.
The present invention has been made in view of such circumstances, eliminates the complexity of searching for a viewable channel by performing a manual full channel scan every time it is viewed, and changes in the reception status accompanying movement between regions. It is an object of the present invention to provide a digital broadcast receiving apparatus and a digital broadcast receiving method that can automatically cope with the above.

In order to solve the above problems, the present application proposes the following technologies.
(1) A tuner unit that selectively extracts a signal of a specific frequency from a received high-frequency digital modulation signal of a digital television broadcast and obtains a transport stream based on the extracted signal of the specific frequency; A decoder unit that obtains a video signal based on the transmitted transport stream, a system controller that comprehensively controls each unit including the tuner unit and the decoder unit, and a video display and display related to the reception status of the digital television broadcast. A portable digital broadcast receiving device configured to include a display unit for performing the system controller and the tuner unit, and the system controller and the tuner unit may be capable of receiving broadcast waves that can be received by their cooperation. Scanning a frequency band or a relatively wide frequency band, the digital broadcast receiving apparatus Scanning operation in full scan mode that detects broadcast waves including broadcast signals that can be viewed at the current location and scanning at a relatively narrow frequency band that is a part of the entire frequency band allows viewing at the current location A scanning operation in a local scan mode for detecting a broadcast wave including a broadcast signal is selectively executed, and a reception status detected as a result of the execution is displayed on the display unit. A digital broadcast receiver characterized by the above.

  In the digital broadcast receiving apparatus according to (1), the digital broadcast is scanned by scanning the entire frequency band or the relatively wide frequency band in which a receivable broadcast wave may exist by the cooperation of the system controller and the tuner unit. Scanning operation in full scan mode that detects broadcast waves including broadcast signals that can be viewed at the current location where the receiver is located, and the current location by scanning a relatively narrow frequency band that is part of the entire frequency band In order to selectively execute the scanning operation in the local scan mode for detecting broadcast waves including a broadcast signal that can be viewed in the network, it takes time each time to detect a broadcast wave that includes a broadcast signal that can be viewed. It is not necessary to perform a scanning operation in full scan mode, which consumes a large amount of power. Since the scanning operation of Le scan mode is selected, and power saving time is generally reduced until a detection result according to the reception status can be achieved.

(2) The system controller and the tuner unit further select the scanning operation in the slow scan mode in which the scan in the full scan mode and / or the local scan mode is executed at a lower speed than usual by the cooperation of both. The digital broadcast receiving apparatus according to (1), wherein the digital broadcast receiving apparatus is configured to execute automatically.
In the digital broadcast receiving apparatus of (2), particularly in the digital broadcast receiving apparatus of (1), the scanning operation in the slow scan mode in which scanning in the full scan mode and / or the local scan mode is executed at a lower speed than usual. Because it is selectively executed, useless detection is possible by selecting the slow scan mode even under conditions where it is difficult to detect broadcast waves including broadcast signals that can be viewed at the current location in the normal scan mode. Power saving can be achieved by reducing the frequency of operation.

(3) The system controller and the tuner unit initially perform an operation of detecting a broadcast wave including a broadcast signal that can be viewed in the full scan mode, and any broadcast wave including a broadcast signal that can be viewed (1) The digital broadcast receiving apparatus according to (1), which is configured to shift to the local scan mode thereafter.
In the digital broadcast receiving apparatus of (3) above, in particular, in the digital broadcast receiving apparatus of (1), an operation for detecting a broadcast wave including a broadcast signal that can be viewed in the initial full scan mode is executed, and the viewable broadcast Any one of the broadcast waves including the signal is detected, and then the mode shifts to the local scan mode. For this reason, the time required to automatically shift to the local scan mode from the point in time when conditions suitable for detecting broadcast waves including a broadcast signal that can be viewed are established, and the detection result is generally shortened, and power is saved. Figured.

  (4) The system controller and the tuner unit initially perform an operation of detecting a broadcast wave including a broadcast signal that can be viewed in the full scan mode, and include a broadcast signal that can be viewed in the full scan mode. The digital broadcast receiving apparatus according to (2), wherein the digital broadcast receiving apparatus is configured to shift to the slow scan mode when a broadcast wave is not detected.

  In the digital broadcast receiving apparatus of (4), particularly in the digital broadcast receiving apparatus of (2), an operation for detecting a broadcast wave including a broadcast signal that can be viewed in the initial full scan mode is executed. In some cases, when a broadcast wave including a viewable broadcast signal is not detected, the mode is shifted to the slow scan mode. For this reason, it is possible to detect any broadcast wave including a viewable broadcast signal even under a condition in which a broadcast wave including a viewable broadcast signal is not detected depending on the normal full scan mode. Become.

  (5) The system controller and the tuner unit initially perform an operation of detecting a broadcast wave including a broadcast signal that can be viewed in the local scan mode, and a broadcast signal that can be viewed in the local scan mode. The digital broadcast receiving apparatus according to (1), wherein the digital broadcast receiving apparatus is configured to shift to the slow scan mode when no broadcast wave is detected.

  In the digital broadcast receiving apparatus of (5) above, in particular, in the digital broadcast receiving apparatus of (1), an operation of detecting a broadcast wave including a broadcast signal that can be viewed in the local scan mode is executed initially. In some cases, the mode is shifted to the slow scan mode when a broadcast wave including a viewable broadcast signal is not detected. For this reason, it is possible to detect any broadcast wave including a viewable broadcast signal even under a condition in which a broadcast wave including a viewable broadcast signal is not detected depending on the normal local scan mode. Become.

(6) The system controller and the tuner unit are configured to shift to the full scan mode when any broadcast wave including a viewable broadcast signal is detected by shifting to the slow scan mode. (5) The digital broadcast receiver characterized by the above-mentioned.
In the digital broadcast receiver of (6) above, in particular, when any broadcast wave including a broadcast signal that can be viewed is detected by shifting to the slow scan mode once in the digital broadcast receiver of (5), the digital broadcast receiver is full. A transition to the scan mode is made to quickly return to the channel selection operation, and a characteristic with excellent responsiveness to changes in reception conditions is realized.

  (7) Scanning in a full scan mode for detecting a broadcast wave including a broadcast signal that can be viewed at the current position by scanning a receivable broadcast wave from the entire frequency band where the broadcast wave exists to a relatively wide frequency band. Selectively functioning and scanning operation in a local scan mode that detects a broadcast wave including a broadcast signal that can be viewed at the current location by scanning a relatively narrow frequency band that is a part of the entire frequency band. A digital broadcast receiving method, characterized by:

  According to the digital broadcast receiving method of (7) above, a broadcast including a broadcast signal that can be viewed at the current location by scanning a receivable broadcast wave from the entire frequency band where the broadcast wave exists to a relatively wide frequency band. Scanning operation in full scan mode to detect waves, and local scan mode to detect broadcast waves including broadcast signals that can be viewed at the current location by scanning a relatively narrow frequency band that is part of the entire frequency band Scanning operations in the network function selectively, so it is necessary to execute scanning operations in full scan mode, which takes time and consumes a lot of power each time a broadcast wave including a viewable broadcast signal is detected. However, the scanning operation in the local scan mode is selected under appropriate conditions. Shortened and power saving is achieved.

(8) The digital broadcast receiving method according to (7), wherein the scanning operation in the slow scan mode in which the scan in the full scan mode and / or the local scan mode is executed at a lower speed than usual is selectively functioned. .
In the digital broadcast receiving method of (8), particularly in the digital broadcast receiving method of (7), the scanning operation in the slow scan mode in which the scan in the full scan mode and / or the local scan mode is executed at a lower speed than usual. By performing selectively, it is unnecessary to select the slow scan mode even under conditions in which it is difficult to detect a broadcast wave including a broadcast signal that can be viewed at the current location in the normal scan mode. It is possible to save power by reducing the frequency with which the detection operation is performed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings to be referred to below, for the sake of convenience, the main part that is the subject of the description is exaggerated as appropriate, and other than the main part is appropriately simplified or omitted.
FIG. 1 is a block diagram showing a configuration of a digital broadcast receiving apparatus as an embodiment of the present invention. This digital broadcast receiving apparatus takes the form of a so-called “one-segment” digital television receiver attached to a mobile phone, but the illustration of a portion that functions exclusively as a mobile phone is omitted.

  In FIG. 1, a tuner unit 120 that selectively extracts a signal of a specific frequency from a high frequency digital modulation signal of a digital television broadcast received by an antenna 110 and obtains a transport stream based on the extracted signal of the specific frequency; A decoder unit 130 for obtaining a video signal based on the transport stream obtained by the tuner unit 120 is provided, and the output of the decoder unit 130 includes character data formed by the OSD unit 140 and other various display data. The images are combined and supplied to a display unit 150 including, for example, a liquid crystal display, and an image is displayed.

  A system controller 160 is provided for comprehensively controlling each part of the apparatus including the tuner unit 120, the decoder unit 130, and the OSD unit 140. The system controller 160 is provided by the cooperation of the tuner unit 120 and the system controller 160. Functions as a memory unit 170 for holding data and other data as detection results when a broadcast wave including a broadcast signal that can be viewed at the current location where the digital broadcast receiver is located, and a mobile phone An operation unit 180 that accepts operations for the user who also serves as the operation unit to perform various operations is connected. As described above, the memory unit 170 also functions as a network ID memory.

The configuration of the tuner unit 120 and the decoder unit 130 will be described in more detail. The tuner unit 120 includes a demodulation circuit, a deinterleave circuit, an error correction circuit, and the like, demodulates the selected digital modulation signal, outputs a transport stream, and supplies the output transport stream to the decoder unit 130.
The decoder unit 130 converts the supplied transport stream into an H.264 protocol in IEEE. A demultiplexer that separates video streams such as H.264, audio streams, and PSI / SI (Program Specific Information / Service Information) and broadcast information (region identifier, service type, broadcast station identification, service number, remote control key ID), And an H.264 video decoder that decodes an input encoded signal to obtain a quantization coefficient and a motion vector, and performs video compensation by performing inverse DCT transform, motion compensation control based on the motion vector, and the like. It includes a H.264 decoder and the like.

The OSD unit 140 includes an OSD (on-screen display) circuit and an adder. The OSD circuit outputs video data based on character information and color information instructed to be output from the system controller 160 to the adder. The adder performs processing for incorporating the video data from the system controller 160 into the received video data output from the decoding unit 130. With this OSD circuit, it is possible to display a menu screen and a receivable broadcast wave for channel selection (that is, a display as shown in FIG. 4 to be described later indicating a reception status detected by a scanning operation). .

  The digital broadcast receiving apparatus according to the present embodiment having the above-described configuration is capable of receiving a receivable broadcast wave or a relatively wide frequency band by the cooperation of the system controller 160 and the tuner unit 120. Scanning operation in full scan mode for detecting broadcast waves including broadcast signals that can be viewed at the current location where the digital broadcast receiver is located, and a relatively narrow frequency band that is part of the entire frequency band Scanning operation in a local scan mode for detecting a broadcast wave including a broadcast signal that can be viewed at the current location by scanning the image, can selectively function.

For this reason, it is not necessary to perform a scanning operation in the full scan mode, which takes time and consumes a large amount of power every time a broadcast wave including a viewable broadcast signal is detected. Since the scanning operation in the scan mode is selected, the time until the detection result is obtained is generally shortened and power saving is achieved.
Normally, when a product (this digital broadcast receiver) is purchased, the user performs the scanning operation in the full scan mode when using the product for the first time, and then performs the scanning operation in the local scan mode at regular intervals. The display is performed on the display unit 150 according to the situation at that time.

The digital broadcast receiving apparatus according to the present embodiment is a portable type that is attached to a mobile phone, and the location thereof is not constant and is assumed to be accompanied by movement. It is configured to be able to cope with movement, and this is a technical feature.
FIG. 2 is a flowchart showing the operation of the apparatus of FIG. 1 in the full scan mode.

  When the apparatus is activated in response to an operation of turning on the power from the operation unit 180 in FIG. 1 at the beginning of using the digital broadcast receiving apparatus or after that, the channel number to be scanned is first set. The corresponding variable n is set to 1 (step S201). Next, a channel selection operation is attempted for channel n (ie, initially 1 and corresponding to channel 13 which is the first channel) (step S202). Next, an attempt is made to obtain a network ID for channel n targeted for channel selection in step S202 (step S203). It is determined whether or not the network ID has been acquired as a result of the execution of step S203 (step S204). When the network ID is acquired (step S204: Yes), the channel n (that is, initially 1 and 1) The network ID data is recorded for the channel 13 corresponding to the th channel (if the data has already been obtained, the data is rewritten with the newly acquired data (step S205).

  After step S205, it is determined whether or not the variable n corresponding to the channel number has reached the rank N of the channel corresponding to the end scheduled for scanning (for example, 20 and this corresponds to channel 32). Step S206). As a result, when the variable n corresponding to the channel number has not reached the final channel number N scheduled for scanning (step S206: No), 1 is added to the current value of the variable n (step S207) and step S202. Return to.

On the other hand, when the network ID is not acquired in step S204 (step S204: No), the process skips to step S206 without passing through step S205.
Each time a network ID is acquired, the acquired data is stored in a predetermined form in the memory unit 170 as a network ID memory described with reference to FIG. 1 to create a local scan list. This local scan list is a correspondence table between network IDs and reception channels (physical channels).

When it is determined in step S206 that the variable n corresponding to the channel number has reached the rank N of the channel corresponding to the end scheduled for scanning (for example, 20, which corresponds to channel 32) (step S206: Yes). ) Satisfies the scanning conditions in the full scan mode, such as satisfying the number of repetitions when the condition that the scan in the full scan mode is repeated, for example, for the sake of certainty is set. It is determined whether or not the condition is satisfied (step S208). When the scanning condition is satisfied (step S208: Yes), the scanning operation in the full scan mode is terminated. Here, N is, for example, from 13 channels to a maximum of 62 channels, but may be up to 31 channels depending on circumstances.
On the other hand, when the scan condition is not satisfied (step S208: No), the process returns to step S201, and the operation from the beginning in the full scan mode is repeated.

FIG. 3 is a flowchart showing the operation in the local scan mode of the apparatus of FIG. First, the local scan list formed while acquiring the network ID in the scanning process in the full scan mode described with reference to FIG. 2 is referred to (step S301).
Next, the channel number at the beginning of the local scan list is set as a variable n corresponding to the channel number (step S302).

A channel selection operation is attempted for channel n set in step S302 (that is, the first channel in the local scan list initially) (step S303). Next, an attempt is made to obtain a network ID for channel n targeted for channel selection in step S303 (step S304).
As a result of the execution of step S304, it is determined whether or not a network ID has been acquired (step S305). When the network ID is acquired (step S305: Yes), network ID data is newly acquired for that channel n. The data is rewritten (step S306).

  Next, it is determined whether or not the variable n corresponding to the channel number has reached the last channel number in the local scan list (step S307). As a result, when the variable n corresponding to the channel number has not reached the channel number at the end of the local scan list scheduled for scanning (step S307: No), the value of the variable n is set to the next channel number in the local scan list. (Step S308) and the process returns to step S303.

On the other hand, when the network ID is not acquired in step S305 (step S305: No), the process skips to step S307 without passing through step S306.
Each time a network ID is acquired, the local scan list is updated with the acquired data.
If it is determined in step S307 that the variable n corresponding to the channel number has reached the channel number at the end of the local scan list scheduled for scanning (step S307: Yes), the network is normally scanned by scanning in the local scan. It is determined whether or not the ID has been acquired (step S309). If the ID has not been acquired (step S309: No), the scanning operation in the local scan mode is terminated.

On the other hand, when the network ID is properly acquired (step S309: Yes), the process returns to step S301, and the processing in the local scan mode is repeated from the beginning.
As described above, the scanning operation in the full scan mode described with reference to FIG. 2 is to recognize a broadcast station that can be received at the point. For example, whether the point is the Osaka region or the Nagoya region. This is equivalent to identifying whether it is a Nagano area. In addition, the scanning operation in the local scan mode described with reference to FIG. 3 is to sequentially scan NHK 2 station and 4 commercial broadcast stations in the Nagano area, which should exist in that area. The result (reception status indicating reception quality) is displayed on the display unit 150. In this display, for example, the status of signals from each broadcasting station at a certain time in front of the Suwa station in the Nagano area is displayed.

  In the portable digital broadcast receiving apparatus, the status of the received signal varies greatly depending on the location, so that some stations can be received well, and some stations cannot be received. This situation is particularly noticeable indoors and outdoors with many buildings. Corresponding to such a situation, by scanning at regular time intervals, stations that can be correctly received at the location can be displayed.

FIG. 4 is a diagram illustrating a state in which the channel for which the network ID is properly acquired is displayed on the display unit 150 in FIG. In the illustrated case, the channel B is displayed as a channel for which the network ID has been acquired normally, for example, by turning on or changing the display color.
In the embodiment of the present invention, the system controller 160 and the tuner unit 120 further perform scanning in the above-described full scan mode and local scan mode at a lower speed than usual (that is, more than usual). It is configured to selectively execute a scanning operation in a slow scan mode (which is also performed at a wide scan interval).

  This means that when you are in a place where reception is not possible, such as in a building for a long time, the scanning operation is performed in slow scan mode, reducing the frequency of unnecessary detection operations and saving power (battery saving). This is for the purpose of illustration. If you come to a good reception point such as outdoors in the slow scan state, you can receive the channel that you received at that time, so it is judged that there is no need for scanning operation in slow scan mode, and scanning in full scan mode once After executing the operation, shift to the local scan mode.

  FIG. 5 is a flowchart showing the operation in the slow scan mode of the apparatus of FIG. First, a variable n corresponding to the channel number to be scanned is set to 1 (step S501). Next, a channel selection operation is attempted for channel n (that is, initially 1 and corresponding to channel 13 which is the first channel) (step S502). Next, an attempt is made to acquire a network ID for channel n targeted for channel selection in step S502 (step S503).

  As a result of the execution of step S503, it is determined whether or not a network ID has been acquired (step S504). When a network ID is acquired (step S504: Yes), data of the network ID is recorded for the channel n (already If data is obtained, the data is rewritten with newly acquired data (step S505), and the slow scan is terminated.

On the other hand, when the network ID is not acquired in step S504 (step S504: No), the variable n corresponding to the channel number is the rank N of the channel corresponding to the end scheduled for scanning (for example, 20 and this is the channel 32). Is determined (step S506).
As a result, when the variable n corresponding to the channel number has not reached the final channel number N scheduled for scanning (step S506: No), 1 is added to the current value of the variable n (step S507) and step S502. Return to.

On the other hand, when the variable n corresponding to the channel number reaches the final channel number N scheduled for scanning (step S506: Yes), the slow scan is terminated.
As described above, recording or rewriting of network ID data in the full scan mode, the local scan mode, and the slow scan mode described with reference to FIGS. This is performed when the operation of the broadcast receiving apparatus is started or when the reception is resumed after the slow scan.

  At the start of the operation of the digital broadcast receiving apparatus, the network ID is recorded for the first time. When the full scan mode is executed after the scanning operation in the slow scan mode, for example, after moving from Tokyo to Hokkaido, the Tokyo ID is rewritten to the Hokkaido ID. If you are in a place where you cannot receive, such as in a building, and you go outside, you will write the same ID again.

FIG. 6 is a flowchart showing an example of scan mode switching at the beginning of power-on in the apparatus of FIG.
In this example, at the beginning of power-on, the full scan mode described with reference to the flowchart of FIG. 2 is executed (step S601). It is determined whether or not the network ID is detected by the scanning operation in the full scan mode in step S601 (step S602). When the network ID is detected (step S602: Yes), the flowchart of FIG. The local scan mode described with reference to this is executed (step S603).

It is determined whether or not the network ID is detected by the scanning operation in the local scan mode in step S603 (step S604). When the network ID is detected (step S604: Yes), the local scan mode is repeated thereafter. (Step S603).
When it is determined in step S602 that the network ID has not been detected depending on the full scan mode (step S602: No), and when it is determined in step S604 that the network ID has not been detected depending on the local scan mode ( Step S604: No) In any case, the scanning operation in the slow scan mode described with reference to the flowchart of FIG. 5 is executed (Step S605).

    It is determined whether or not the network ID is detected by the scanning operation in the slow scan mode in step S605 (step S606). When the network ID is detected (step S604: Yes), the process returns to step S601. When it is determined that the ID has not been detected (step S606: No), the slow scan mode is repeated (step S605).

  As described above, in the example described with reference to the flowchart of FIG. 6, initially, an operation of detecting a broadcast wave including a broadcast signal that can be viewed in the full scan mode is performed, After the broadcast wave is detected, the mode shifts to the local scan mode (step S601 → step S602 → step S603). For this reason, the time required to automatically shift to the local scan mode from the point in time when conditions suitable for detecting broadcast waves including a broadcast signal that can be viewed are established, and the detection result is generally shortened, and power is saved. Figured.

In addition, an operation of detecting a broadcast wave including a broadcast signal that can be viewed in the full scan mode is initially performed. When a broadcast wave including a broadcast signal that can be viewed is not detected in the full scan mode, the slow scan mode is selected. (Step S601 → Step S602 → Step S605). For this reason, it is possible to detect any broadcast wave including a viewable broadcast signal even under a condition in which a broadcast wave including a viewable broadcast signal is not detected depending on the normal full scan mode. Become.

  Further, when any broadcast wave including a viewable broadcast signal is detected by shifting to the slow scan mode, the mode shifts to the full scan mode (step S605 → step S606 → step S601), and quick channel selection is performed. A return to operation is performed, and a characteristic excellent in responsiveness to changes in the reception status is realized.

FIG. 7 is a flowchart showing another example of switching of scan modes at the beginning of power-on in the apparatus of FIG. This example is executed when the above-described local scan list is prepared.
In this example, at the beginning of power-on, the local scan mode described with reference to the flowchart of FIG. 3 is executed (step S701). It is determined whether or not the network ID is detected by the scanning operation in the local scan mode in step S701 (step S702). When the network ID is detected (step S702: Yes), the local scan mode is subsequently used. The scanning operation is repeated (step S701).

When it is determined in step S702 that the network ID has not been detected (step S702: No), the process proceeds to the scanning operation in the slow scan mode described with reference to the flowchart of FIG. 5 (step S703).
It is determined whether or not the network ID is detected by the scanning operation in the slow scan mode in step S703 (step S704). When it is determined that the network ID is detected (step S704: Yes), the flowchart of FIG. The process proceeds to the scanning operation in the full scan mode described with reference to step S705.

It is determined whether or not the network ID is detected by the scanning operation in the full scan mode in step S705 (step S706). When it is determined that the network ID is detected (step S706: Yes), the process returns to step S701.
On the other hand, when it is determined in step S704 that the network ID has not been detected depending on the slow scan mode (step S704: No) and when it is determined in step S706 that the network ID has not been detected depending on the full scan mode ( Step S706: No), in any case, the slow scan mode is repeated (step S703).

As described above, in the example described with reference to FIG. 7, initially, an operation of detecting a broadcast wave including a broadcast signal that can be viewed in the local scan mode is executed, and in the local scan mode, a broadcast signal that can be viewed is displayed. When no broadcast wave is detected, the mode shifts to the slow scan mode (step S701 → step S702 → step S703). For this reason, it is possible to detect any broadcast wave including a viewable broadcast signal even under a condition in which a broadcast wave including a viewable broadcast signal is not detected depending on the normal local scan mode. Become.
Further, when any broadcast wave including a viewable broadcast signal is detected by shifting to the slow scan mode, the mode shifts to the full scan mode (step S703 → step S704 → step S705), and quick tuning is performed. A return to operation is performed, and a characteristic excellent in responsiveness to changes in the reception status is realized.

FIG. 8 is a diagram for explaining a scan interval in each scan mode.
In full scan mode, all channels are scanned at intervals of about 1 second. This may be repeated a plurality of times. Thereafter, a scanning operation is performed in the local scan mode after an interval of about 10 seconds. Each channel scan interval in the local scan mode is about 1 second. This is repeated as a normal state. When the slow scan mode is entered, a predetermined channel scan is performed at an interval of about 10 seconds for each channel. This is repeated, but the repetition interval is about 100 seconds. Therefore, in the slow scan mode as compared with the normal scanning mode, the frequency of channel detection is roughly one-tenth, and power saving is achieved according to this time interval.

  In the full scan mode, all channels assigned to terrestrial digital broadcasting, that is, 13 to 62 channels in the UHF band are sequentially scanned. However, in actuality, all of channels 13 to 62 are not used (in each region, about 10 to 15 channels at most and within 32 channels), and appropriate channels (for example, 32 channels) ) Is practically sufficient. The example shown is drawn in the range where all the channels in the Tokyo suburbs and the Kanto area are scanned, and the reason why it jumps to the 20th channel after the 18th channel is because 19th channel is not used in Tokyo. . As described above, in the local scan mode, a part of the frequency band to be scanned in the full scan mode is received.

As described above with reference to the flowchart of FIG. 2, the full scan mode may be repeatedly executed a predetermined number of times in order to surely perform the detection.
In the full scan mode, each channel may be sequentially scanned, and the odd channel and the even channel may be alternately scanned.
In the slow scan mode, it is considered sufficient to scan up to 32 channels. Also in the slow scan mode, each channel may be scanned sequentially, and the odd channel and even channel may be alternately scanned.

  As described above, the technical idea of the present invention described with reference to each figure is that the receivable broadcast wave can be viewed at the current location by scanning the entire frequency band where the broadcast wave exists or a relatively wide frequency band. Scanning operation in full scan mode that detects broadcast waves including signals and scanning a relatively narrow frequency band that is a part of the entire frequency band to detect broadcast waves including broadcast signals that can be viewed at the current location It can be seen as a digital broadcast receiving method characterized by selectively functioning a scanning operation in the local scan mode.

According to this method, when detecting a broadcast wave including a broadcast signal that can be viewed, it is not necessary to perform a scanning operation in the full scan mode that takes time and consumes a large amount of power each time. Since the scanning operation in the local scan mode is selected below, the time until the detection result is obtained is generally shortened and power saving is achieved.
Further, in the above-described method, particularly in the normal scan mode, by selectively performing the scanning operation in the slow scan mode in which the scan in the full scan mode and / or the local scan mode is executed at a lower speed than usual. Even under conditions where it is difficult to detect a broadcast wave including a broadcast signal that can be viewed at the current location, by selecting the slow scan mode, the frequency of useless detection operations is reduced to save power. be able to.

It is a block diagram showing the structure of the digital broadcast receiver as embodiment of this invention. 2 is a flowchart illustrating an operation in a full scan mode of the apparatus of FIG. 1. 2 is a flowchart showing an operation in a local scan mode of the apparatus of FIG. 1. It is a figure showing a mode that the channel from which network ID was acquired normally is displayed on the display part 150 of FIG. It is a flowchart showing the operation | movement in the slow scan mode of the apparatus of FIG. 2 is a flowchart showing an example of switching of scan modes at the beginning of power-on in the apparatus of FIG. 6 is a flowchart illustrating another example of switching of scan modes at the beginning of power-on in the apparatus of FIG. 1. It is a figure for demonstrating the scan interval in each scan mode.

Explanation of symbols

DESCRIPTION OF SYMBOLS 110 ... Antenna 120 ... Tuner part 130 ... Decoder part 140 ... OSD part 150 ... Display part 160 ... System controller 170 ... Memory part 180 ... Operation part

Claims (8)

  A tuner unit that selectively extracts a signal of a specific frequency from the received high-frequency digital modulation signal of the digital television broadcast and obtains a transport stream based on the extracted signal of the specific frequency, and a transformer obtained by the tuner unit Decoder unit for obtaining video signal based on port stream, system controller for comprehensively controlling each unit including the tuner unit and the decoder unit, and a display unit for displaying video display and reception status of the digital television broadcast The system controller and the tuner unit are configured to include all frequency bands in which a receivable broadcast wave may exist due to their cooperation. The digital broadcast receiver is positioned by scanning a relatively wide frequency band. Scanning operation in a full scan mode that detects broadcast waves including broadcast signals that can be viewed at the current location and scanning at a relatively narrow frequency band that is a part of the entire frequency band allows viewing at the current location A scanning operation in a local scan mode for detecting a broadcast wave including a broadcast signal is selectively executed, and a reception status detected as a result of the execution is displayed on the display unit. A digital broadcast receiver characterized by the above.   Further, the system controller and the tuner unit selectively execute a scanning operation in the slow scan mode in which the scan in the full scan mode and / or the local scan mode is executed at a lower speed than usual by the cooperation of both. The digital broadcast receiving apparatus according to claim 1, wherein the digital broadcast receiving apparatus is configured to do so.   The system controller and the tuner unit initially perform an operation to detect a broadcast wave including a viewable broadcast signal in the full scan mode, and any broadcast wave including a viewable broadcast signal is detected. The digital broadcast receiving apparatus according to claim 1, wherein the digital broadcast receiving apparatus is configured to shift to the local scan mode thereafter.   The system controller and the tuner unit initially perform an operation of detecting a broadcast wave including a broadcast signal that can be viewed in the full scan mode, and a broadcast wave including a broadcast signal that can be viewed in the full scan mode. 3. The digital broadcast receiving apparatus according to claim 2, wherein the digital broadcast receiving apparatus is configured to shift to the slow scan mode when it is not detected.   The system controller and the tuner unit initially perform an operation of detecting a broadcast wave including a broadcast signal that can be viewed in the local scan mode, and a broadcast wave including a broadcast signal that can be viewed in the local scan mode. The digital broadcast receiving apparatus according to claim 1, wherein the digital broadcast receiving apparatus is configured to shift to the slow scan mode when no video is detected.   The system controller and the tuner unit are configured to shift to the full scan mode when any broadcast wave including a viewable broadcast signal is detected by shifting to the slow scan mode. The digital broadcast receiver according to claim 5.   Scanning operation in a full scan mode for detecting a broadcast wave including a broadcast signal that can be viewed at a current position by scanning a receivable broadcast wave from an entire frequency band where the broadcast wave exists to a relatively wide frequency band, and the above-described scanning operation Scanning a relatively narrow frequency band that is a part of the entire frequency band to selectively function a scanning operation in a local scan mode that detects a broadcast wave including a broadcast signal that can be viewed at the current location. A digital broadcast receiving method as a feature.   8. The digital broadcast receiving method according to claim 7, wherein a scanning operation in a slow scan mode in which scanning in the full scan mode and / or the local scan mode is executed at a lower speed than usual is selectively executed.

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