Abstract:
A digital broadcast receiver includes a receiver circuit that catches a digital broadcast and outputs at least an audio signal and information concerning the digital broadcast on a predetermined channel; numeric keys; a preset table included in a non-volatile memory; and a control circuit. The control circuit scans a frequency band of the digital broadcast, acquires data sets of channel data used for catching the digital broadcast on a channel and the information caught on the channel, sorts the data sets on the basis of at least one item included in the information as a condition, registers the acquired data sets in the preset table, and extracts the data set corresponding to a numeric key that is pressed, in the data sets registered in the preset table, to set the channel data included in the extracted data set in the receiver circuit.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
       [0001]    The present invention contains subject matter related to Japanese Patent Application JP 2006-139744 filed in the Japanese Patent Office on May 19, 2006, the entire contents of which are incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a receiver for digital television (TV) broadcasting. 
         [0004]    2. Description of the Related Art 
         [0005]    Receivers for digital TV broadcasting each have a function of selecting a preset channel (TV station) (hereinafter referred to as a channel preset function) and a channel up-down function. 
         [0006]    When the channel preset function is enabled, pressing any of numeric keys provided on a transmitter of a remote controller allows the channel preset for the pressed key to be selected. When the channel up-down function is enabled, sequential pressing a channel-up key or a channel-down key allows preset channels to be sequentially selected. 
         [0007]    In order to realize such functions, a user of a table-top receiver for terrestrial digital TV broadcasting is prompted to input information, such as a postal code, indicating the location where the receiver is used when the receiver is installed. After the user inputs the information indicating the location, channels that can be tuned in the area including the location are automatically registered in a preset memory. 
         [0008]    Accordingly, it is possible to use the channel preset function and the channel up-down function after the registration. In addition, combination of the channel preset function and the channel up-down function with information about programs allows a program list to be displayed. 
         [0009]    Japanese Unexamined Patent Application Publication No. 2004-343235 discloses a technology relating to the digital broadcast receiver in related art. 
       SUMMARY OF THE INVENTION 
       [0010]    The locations where portable receivers are used are not fixed. The portable receivers include receivers mounted in movable bodies, such as automobiles, and receivers included in mobile computers or mobile phones. Accordingly, in order to use the channel preset function and the channel up-down function in the portable receivers, it is necessary to input information indicating the locations where the receivers are used each time the portable receivers move, thus degrading the usability. 
         [0011]    In order to resolve the above problem, the positions of receivers are detected by using, for example, Global Positioning System (GPS) and tunable channels are set in memories on the basis of the detected positional information. However, structures and processing to determine service areas corresponding to the positional information become complicated in the above method because the service areas do not have simple shapes. In addition, if a receiver is located in a boundary area between two service areas, it often tends to become ambiguous about which service area the boundary area is included in even if the position of the receiver can be identified. 
         [0012]    In order to resolve above problems, according to an embodiment of the present invention, a digital broadcast receiver includes a receiver circuit that catches a digital broadcast and outputs at least an audio signal and information concerning the digital broadcast on a predetermined channel; numeric keys; a preset table included in a non-volatile memory; and a control circuit that scans a frequency band of the digital broadcast, acquires data sets of channel data used for catching the digital broadcast on a channel and the information caught on the channel, if the digital broadcast is caught on the channel during the scanning, sorts the data sets on the basis of at least one item included in the information as a condition, registers the data sets acquired from the sorting in the preset table, and extracts the data set corresponding to a numeric key that is pressed, in the data sets registered in the preset table, to set the channel data included in the extracted data set in the receiver circuit. 
         [0013]    According to another embodiment of the present invention, a preset method in a receiver catching a digital broadcast includes the steps of catching a digital broadcast and outputting at least an audio signal and information concerning the digital broadcast on a predetermined channel; scanning a frequency band of the digital broadcast; acquiring data sets of channel data used for catching the digital broadcast on a channel and the information caught on the channel, if the digital broadcast is caught on the channel during the scanning; sorting the data sets on the basis of at least one item included in the information as a condition; registering the data sets acquired from the sorting in a preset table; and extracting the data set corresponding to a numeric key that is pressed, in the data sets registered in the preset table, to set the channel data included in the extracted data set in a receiver circuit. 
         [0014]    According to the present invention, even if the reception position is varied, it is not necessary to input the reception position and only pressing, for example, a scan key allows a channel to be preset. 
         [0015]    In addition, since it is not necessary to detect the position of the receiver by using, for example, the GPS or to determine the service area corresponding to the detection result, the configuration and processing do not become complicated. Furthermore, it is possible to preset a channel even in a boundary area between two service areas. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a block diagram showing an example of the configuration of a receiver for terrestrial digital TV broadcasting according to an embodiment of the present invention; 
           [0017]      FIG. 2  is a flowchart showing a routine according to an embodiment of the present invention; 
           [0018]      FIG. 3  shows an example of a data table according to an embodiment of the present invention; 
           [0019]      FIG. 4  shows an example of the content of data processing according to an embodiment of the present invention; 
           [0020]      FIG. 5  shows an example of a station name list according to an embodiment of the present invention; and 
           [0021]      FIG. 6  shows an example of the content of digital data. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Transmitted Information Signal and Terms 
       [0022]    In terrestrial digital TV broadcasting, various information signals are transmitted, in addition to video signals, audio signals, and data signals. The information signals and terms concerning embodiments of the present invention will now be simply described. 
       (1) Service ID 
       [0023]    Service identifications (IDs) are uniquely assigned to services available in each region. As shown in  FIG. 6 , each service ID includes a “region ID”, a “duplicate flag”, a “service type”, a “regional broadcaster ID”, and a “service number”. 
         [0024]    The “regional ID” defines each region. The “regional broadcaster ID” defines each TV broadcaster in the region indicated by the “region ID”. The “service type” is used to discriminate TV broadcasting or data broadcasting. The “service number” is used to specify a service in each “service type”. When two transport streams (TSs) are transmitted in the same region, the “duplicate flags” for the respective TSs are added to the original service ID to differentiate the service IDs of the two TSs. 
       (2) Affiliate ID 
       [0025]    An affiliate ID indicates an affiliate station in the TV broadcasting. 
       (3) Broadcaster Information Table (BIT) 
       [0026]    A BIT is a data table of information concerning broadcasters (designated broadcasters or groups of the designated broadcasters). The BIT includes “extensive broadcaster descriptors” including the above affiliate IDs. Accordingly, the BIT can be used to determine an affiliate ID necessary for a portable receiver to continuously catch the broadcast in a fringe area. 
       (4) Event Information Table (EIT) 
       [0027]    An EIT is a data table of information concerning programs and includes a program list, names of the programs, date and times when the programs are broadcast, description of the content of the programs, and so on. The EIT can be used to acquire program information, such as the start and end times of an event that is being broadcast and of events that are to be sequentially broadcast. 
       Configuration 
       [0028]      FIG. 1  is a block diagram showing an example of the configuration of a receiver for the terrestrial digital TV broadcasting according to an embodiment of the present invention. In a receiver circuit  10 , a broadcast wave of the terrestrial digital TV broadcasting is received through an antenna  11 . The received signal is supplied to a tuner circuit  12  in a synthesizer format. The received signal including a target channel (service) is converted into an intermediate-frequency signal by the tuner circuit  12 . 
         [0029]    The intermediate-frequency signal is supplied to a demodulator circuit  14  through an intermediate-frequency (IF) circuit  13  to be demodulated into digital data (a transport stream) in Moving Picture Experts Group phase 2 (MPEG2) format. The digital data is supplied to a transport stream (TS) decoder circuit  15  where video and audio data streams of the target channel are selected and decoded. 
         [0030]    The decoded video data stream is supplied to a video decoder circuit  16  to be decoded into the original digital video signal. The digital video signal is supplied to a display unit, for example, a liquid crystal display (LCD) panel  18  through an on-screen display (OSD) circuit  17  to display a video of the target channel in the LCD panel  18 . 
         [0031]    The OSD circuit  17  controls supply of the video signal from the video decoder circuit  16  to the LCD panel  18  in accordance with a control signal supplied from a system control circuit  30  described below. The OSD circuit  17  also generates a digital video signal used for displaying a predetermined text (including figures and signs) in accordance with display data supplied from the system control circuit  30  and supplies the generated digital video signal to the LCD panel  18 . 
         [0032]    The audio data stream decoded by the TS decoder circuit  15  is supplied to an audio decoder circuit  21 . The audio data stream is decoded into the original digital audio signal and is subjected to digital-to-analog conversion to convert the digital audio signal into an analog signal in the audio decoder circuit  21 . The analog signal is supplied to a speaker  22  to output an audio corresponding to the video displayed in the LCD panel  18  from the speaker  22 . 
         [0033]    The information signals described above in (1) to (4) are extracted from the TS decoder circuit  15  and the extracted information signals are supplied to the system control circuit  30 . Status signals are supplied from the demodulator circuit  14  and the TS decoder circuit  15  to the system control circuit  30 . The system control circuit  30  supplies a channel selection signal to the tuner circuit  12  and supplies a control signal to the TS decoder circuit  15 . 
         [0034]    The system control circuit  30  controls, for example, the reception in the receiver circuit  10  and the display in the LCD panel  18 . The system control circuit  30  is a microcomputer including a central processing unit (CPU)  31 , a read only memory (ROM)  32  in which various programs are written, a random access memory (PAM)  33  functioning as a working area, and a non-volatile memory  34 . 
         [0035]    Various operation keys  41  and a receiver  42  of a remote controller are connected to the system control circuit  30 . The receiver  42  is twinned with a transmitter  50  of the remote controller. The transmitter  50  and the receiver  42  realize the remote control using infrared rays. The transmitter  50  includes, as part of the operation keys  41 , numeric keys  51  from “1” to “12” and a Next key  52 N and a 
         [0036]    Previous key  52 P used for realizing the channel up-down function. The numeric keys  51  are preset keys used for realizing the channel preset function in a manner described below. 
         [0037]    The ROM  32  in the system control circuit  30  includes, for example, a routine  100  shown in  FIG. 2  as part of the programs. The routine  100  is used to register data for the channel preset function. The routine  100  will be described in detail below. Only the part of the routine  100  relating to the embodiments of the present invention is shown in  FIG. 2 . 
         [0038]    The memory  34  in the system control circuit  30  includes, for example, a preset table PTBL shown in  FIG. 3 . The preset table PTBL is used to realize the selection of a channel by using the channel preset function. The routine  100  is executed to register necessary data in the preset table PTBL. 
         [0039]    In the example in  FIG. 3 , the preset table PTBL includes channel data D CH, station name data D NAME, channel number data D NO, and other data Di as a set for every key in the numeric keys  51  on the transmitter  50  of the remote controller. 
         [0040]    The channel data D CH includes data that is supplied to the tuner circuit  12  as the channel selection signal to select a received signal including the target channel and data that is supplied to the TS decoder circuit  15  as the control signal to select video and audio data streams of the target channel. 
         [0041]    The station name data D NAME is used to display, for example, the names and logos of TV stations in the LCD panel  18 . The channel number data D NO is used to display channel numbers in the LCD panel  18 . The data Di corresponds to the above pieces of data (1) to (4) (and data acquired from processing of the above pieces of data (1) to (4)). 
       Operation 
     Presetting of Channel 
       [0042]    In order to preset a channel, a user presses a scan key in the operation keys  41 . The CPU  31  executes the routine  100  in response to the scan key pressed by the user to scan the frequency band of the terrestrial digital TV broadcasting whereby presetting the channel. 
         [0043]    Referring to  FIG. 2 , when the scan key is pressed, in Step S 101 , the CPU  31  starts to execute the routine  100 . In Step S 102 , the CPU  31  sets the number of the channel (reception channel) included in the signal received by the tuner circuit  12  as the lowest channel number in the terrestrial digital TV broadcasting in accordance with the channel selection signal supplied from the system control circuit  30 . In Step S 111 , the CPU  31  checks the status signal supplied from the demodulator circuit  14  to determine whether the digital data (transport stream) can be received on the reception channel that is set. 
         [0044]    If the digital data can be received, then in Step S 112 , the CPU  31  extracts the data Di described above in (1) to (4) from the TS decoder circuit  15 , stores the extracted data Di in the RAM  33 , and goes to Step S 113 . If the digital data cannot be received in Step S 111 , the CPU  31  goes to Step S 113 . 
         [0045]    In Step S 113 , the CPU  31  determines whether the number of the channel set in the tuner circuit  12  is the highest channel number. If the number of the channel set in the tuner circuit  12  is not the highest channel number, the CPU  31  goes to Step S 114  to set the reception channel in the tuner circuit  12  to a channel having a number one higher than that of the reception channel currently set and goes back to Step S 111 . 
         [0046]    Since Steps S 111  to S 114  are repeated, all the channels in the frequency band of the terrestrial digital TV broadcasting are sequentially checked (scanned), from the channel having the lowest number, to determine whether the broadcast can be caught on the channels. In the scanning, the data Di, described above in (1) to (4), concerning the reception channels on which the broadcast can be caught is stored in the RAM  33 . 
         [0047]    After the determination of the channel having the highest number is finished, the CPU  31  goes to Step S 121  to sort the data stored in the RAM  33 . The sorting is performed in, for example, a manner shown in  FIG. 4 .  FIG. 4  shows a case in which the routine  100  is executed for a certain region to store the broadcast data concerning regions AAA and BBB in the RAM  33 . 
         [0048]    In the sorting in Step S 121 , the registered data is sorted for every region and the data is sorted for every affiliate station in the same region, as shown in the example in  FIG. 4 . The sorting for every region can be performed by using the region IDs described above in (1) Service ID. The sorting for every affiliate station is performed by using the affiliate IDs described above in (2) Affiliate ID. 
         [0049]    For example, if only the data concerning the broadcast in the region AAA is stored in the RAM  33 , that is, if all the region IDs are equal to each other, the sorting for every region is not necessary. If any processing is necessary for the data described above in (1) to (4), the processing can be performed in Step S 121 . 
         [0050]    In Step S 122 , the CPU  31  copies the sorting result in Step S 121  in the preset table PTBL in the memory  34 . Since the scanning result in Steps S 111  to S 114  is registered in the preset table PTBL in Step S 122 , the numbers of the channels that can catch the broadcast are preset in the numeric keys  51 . In Step S 123 , the CPU  31  terminates the routine  100 . 
         [0051]    As described above, it is possible to preset the numbers of the channels that can catch the terrestrial digital TV broadcast in the numeric keys  51  by performing the routine  100 . 
       Selection of Channel by Channel Preset Function 
       [0052]    In selection of a channel by the channel preset function, the user presses the numeric key for which a target channel is preset, among the numeric keys  51  on the transmitter  50  of the remote controller. 
         [0053]    Specifically, for example, if the user presses the “3” key in the numeric keys  51 , the pressing of the “3” key is transmitted from the transmitter  50  to the receiver  42  by an infrared ray to indicate to the system control circuit  30  that the “3” key is pressed. In the system control circuit  30 , the channel data D CH 3  is extracted from the set of the “3” key in the preset table PTBL stored in the memory  34 . The extracted channel data D CH 3  is supplied to the tuner circuit  12  and the TS decoder circuit  15   
         [0054]    As a result, the received signal including the channel preset for the “3” key is selected in the tuner circuit  12 , and the video and audio data streams of the channel preset for the “3” key are selected and decoded in the TS decoder circuit  15 . Accordingly, the digital video signal of the channel preset for the “3” key is extracted from the video decoder circuit  16  and the extracted digital video signal is supplied to the LCD panel  18  through the OSD circuit  17 , to display the video of the channel preset for the “3” key in the LCD panel  18 . 
         [0055]    The analog audio signal of the channel preset for the “3” key is supplied from the audio decoder circuit  21  to the speaker  22  to output the audio of the channel preset for the “3” key from the speaker  22 . In addition, the station name data “ZZ TELEVISION” and the channel number data “*4*” are extracted from the set of the “3” key in the preset table PTBL, and the extracted station name data “ZZ TELEVISION” and channel number data “*4*” are supplied to the OSD circuit  17  as the display data. A predetermined digital video signal corresponding to the display data is generated in the OSD circuit  17 , and the generated digital video signal is supplied to the LCD panel  18 . As a result, the station name “ZZ TELEVISION” and the channel number “*4*” of the channel preset for the “3” key are superimposed on the broadcast video, and the broadcast video on which the station name “ZZ TELEVISION” and the channel number “*4*” are superimposed is displayed in the LCD panel  18  for a predetermined period. 
         [0056]    As described above, pressing any key in the numeric keys  51  allows the channel preset for the pressed key to be selected, and the broadcast can be caught on the channel. 
       Selection of Channel by Channel Up-Down Function 
       [0057]    In selection of a channel by the channel up-down function, the user presses the Next key  52 N or the Previous key  52 P on the transmitter  50  of the remoter controller while the broadcast is being caught on any channel in the channels preset in the preset table PTBL. 
         [0058]    The pressing of the Next key  52 N or the Previous key  52 P is indicated to the system control circuit  30  in the same manner as in “Selection of Channel by Channel Preset Function”. The channel data D CH concerning a channel next or previous to the channel on which the broadcast is currently caught, among the pieces of the channel data in the preset table PTBL, is extracted, and the extracted channel data D CH is supplied to the tuner circuit  12  and the TS decoder circuit  15 . As a result, the selection of a channel next or previous to the channel on which the broadcast is currently caught is started in the same manner as in “Selection of Channel by Channel Preset Function”. 
         [0059]    In addition, all the pieces of the station name data D NAME and the channel number data D NO registered in the preset table PTBL are extracted, and the extracted pieces of the data are supplied to the OSD circuit  17  as the display data. Predetermined digital video signals corresponding to the display data are generated in the OSD circuit  17 , and the generated digital video signals are supplied to the LCD panel  18 . As a result, the station names and the channel numbers are displayed in a station name list  18 L in the LCD panel  18 , as in a manner shown in  FIG. 5 . 
         [0060]    A cursor  18 C is displayed as an index on the row where the station name and the channel number of a channel next or previous to the channel on which the broadcast is currently caught are displayed in the station name list  18 L. In the example shown in  FIG. 5 , the cursor  18 C is displayed on the row where the “ZZ TELEVISION” and the “*4*” are displayed. The cursor  18 C may be highlighted. 
         [0061]    After a predetermined short time period elapsed since the video and audio of a channel next or previous to the channel on which the broadcast is currently caught have been yielded, the OSD circuit  17  is controlled so as not to display the station name list  18 L in  FIG. 5 . 
         [0062]    Accordingly, each time the Next key  52 N or the Previous key  52 P is pressed, the next or previous key is selected. The user can watch and listen to the video and audio of a channel next or previous to the channel on which the Next key  52 N or the Previous key  52 P is finally pressed. 
       SUMMARY 
       [0063]    Since the TV receiver described above according to the embodiment of the present invention is installed in, for example, an automobile, it is not necessary to input the position where the broadcast is caught even if the position is varied as the automobile moves and only pressing the scan key allows a channel to be preset, thus improving the usability. 
         [0064]    Since it is not necessary to detect the position of the receiver by using, for example, the GPS or to determine the service area corresponding to the detection result, the configuration and processing do not become complicated. Furthermore, it is possible to preset a channel even in a boundary area between two service areas. 
         [0065]    Since the affiliate station names are sequentially displayed in the station name list  18 L because of the sorting in Step S 121  and the affiliate station names are displayed in the same order in all the regions, it is easy to select the channel even if the automobile moves to any region. In addition, the pieces of the data in the program list in the other data Di are simultaneously sorted in Step S 121 , it becomes easy to view the program list. 
         [0066]    Although the sorting is performed in the manner shown in  FIG. 4  when the data stored in the RAM  33  is sorted in Step S 121 , the data may be sorted in accordance with a condition set by the user in advance. Alternatively, the user may select one condition from multiple sorting conditions set in advance. The data Di may be sorted in the preset table PTBL. 
         [0067]    Although the pressing of the scan key in the operation keys  41  starts the processing of the routine  100  in the embodiment of the present invention described above, the routine  100  may be automatically executed in the background when the TV broadcast is not caught, for example, while a compact disc (CD) is being played back, in the case of the receiver mounted in a car audio device. In addition, the data in the RAM  33  may be cached until the next scanning is performed and the cached data may be used when new data is processed. 
         [0068]    It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.