JP2008294865A - Digital broadcast receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital broadcast receiver capable of accurately correcting time information of a clock section. <P>SOLUTION: When the time, preset by a user, to perform time information correction comes, all receivable channels are tuned in by a tuner section 6, and time information contained in a TS (transport stream) signal obtained by tuning is scrutinized by a time information scrutiny section 16 and then verified by a time information verification section 17. Thus, time information of highest certainty is derived and based on the derived time information, time information of a clock section 3 is corrected. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a digital broadcast receiver that has a clock unit that manages time information and corrects the time information of the clock unit by using information included in data added to a broadcast signal of a digital broadcast. is there.

  With the recent development of digital technology, digitalization is also progressing in the broadcasting field, and terrestrial digital television broadcasting / BS (Broadcasting Satellite) digital broadcasting / CS (Communications Satellite) digital broadcasting and the like have been put into practical use.

With the widespread use of digital broadcasting, terrestrial analog television broadcasting that has been conducted in Japan is scheduled to be completed by the end of July 2011. / It is planned to make a complete transition to digital terrestrial television broadcasting that can realize high functionality (for example, provision of interactive services).
In addition, although this digital broadcasting is somewhat different in terms of broadcasting technology standards and the like, it is a global trend and has been put to practical use in various countries such as European countries.

  In digital broadcasting such as terrestrial digital television broadcasting, a transport stream (hereinafter abbreviated as TS) composed of video / audio / data (for example, time information and program information) is digital compression technology. It is converted into a digital signal and transmitted to a digital broadcast receiver.

  Here, many digital broadcast receivers are provided with a clock unit for managing current time information inside the receiver, and in particular, have a recording function represented by a DVD (Digital Versatile Disk) recorder. In the digital broadcasting receiver provided, the start and end times of the recording reservation set by the user are based on the time information of the clock unit provided in the receiver, so accurate time information management is indispensable It is.

Conventionally, the time setting related to the time information management of the clock unit has been manually performed by the user. However, it is extremely difficult to set accurate time information by synchronizing with the time information that changes every moment.
Even when the time information can be set accurately, the subsequent time information management is performed by a microprocessor that controls the entire digital broadcast receiver. Since the accuracy varies due to various other factors, the time information to be managed is slightly shifted every day.

In order to solve this problem, Patent Document 1 described later describes a receiver capable of receiving a plurality of digital broadcasts, and this receiver has a dedicated time management for each transmission source. A plurality of clock parts are provided.
Accordingly, one of the plurality of transmission sources is selected as a transmission source to receive, and the digital broadcasting TS signal transmitted from the selected transmission source is received by the receiver, and is included in the received TS signal. After the time information is extracted by the receiver, the time information of the clock unit provided exclusively for the selected transmission source is set or corrected based on the extracted time information.

Further, in Patent Document 2 described later, a transmitter for transmitting a broadcast signal and a receiver for receiving a broadcast signal transmitted from the transmitter are described, and the time set for the transmitter is described. Schedule information including information is created, the created schedule information is included in the broadcast signal, and then the broadcast signal is transmitted to the receiver.
Thereby, the receiver that has received the broadcast signal extracts time information from the schedule information included in the received broadcast signal, and based on the extracted time information, the time of the clock unit provided in the receiver Correct information.

Further, Patent Document 3 described later describes a time correction method for a peripheral device connected to a satellite digital broadcast receiver and having a clock unit. The TS signal of the satellite digital broadcast transmitted from the satellite is described above. The satellite digital broadcast receiver extracts time information contained in the received TS signal.
Here, when the extracted time information is transmitted to a peripheral device connected to the satellite digital broadcast receiver, a transmission delay amount (transmission time) is generated. Therefore, extraction is performed in consideration of this transmission delay amount (transmission time). The corrected time information is corrected, and the corrected time information is transmitted to the peripheral device.
If the difference between the time information transmitted to the peripheral device and the time information held by the clock unit of the peripheral device is 1 minute or more, the clock unit of the peripheral device holds based on the transmitted time information. If the time information is corrected and the deviation is less than 1 minute, the time information held by the clock function of the peripheral device is not corrected.

Japanese Patent Laid-Open No. 10-234013 JP 2000-353970 A JP 2002-228780 A

  In the above Patent Document 1 or 3, the time information of the clock unit provided in the receiver is corrected based on the time information included in the TS signal received by the receiver. The time information is different depending on the transmission source or broadcast source specifications, broadcast editing specifications, and other circumstances. Then, it is difficult to say that the time information can be accurately corrected in terms of the accuracy of the time information.

  Further, in the above-mentioned Patent Document 2, since the time information on the receiver side is set based on the time information set on the transmitter, the time information on the transmitter side is not correctly set. It is not possible to correct the time information accurately.

  In view of the above-described problems, an object of the present invention is to provide a digital broadcast receiver capable of accurately correcting time information of a clock unit.

In the present invention, a channel selection unit for selecting a digital broadcast received from a plurality of transmission sources, a tuner for receiving a broadcast signal of the digital broadcast selected by the channel selection unit, and a broadcast signal received by the tuner In a digital broadcast receiver comprising: a demodulator for demodulating a signal; and a broadcast signal processor for extracting a video signal, an audio signal and a data signal included in the broadcast signal demodulated by the demodulator A time information scrutinizing unit for scrutinizing time information included in the data signal extracted by the signal processing unit, a time information verifying unit for verifying the accuracy of the time information scrutinized by the time information scrutinizing unit, and a time And a clock unit for managing information.
Based on the time information of the clock unit, when the time for correcting the time information of the clock unit has arrived, a plurality of digital broadcasts that can be received by the channel selection unit are selected, and the broadcast signal processing unit performs channel selection. Time information is extracted from the obtained plurality of broadcast signals.
The time information extracted by the broadcast signal processing unit is verified by the time information verification unit, and based on the time information with the highest accuracy among the plurality of time information verified by the time information verification unit, the time of the clock unit Information is corrected.

  Thus, by verifying a plurality of time information extracted from the broadcast signal and correcting the time information of the clock unit using the time information with the highest accuracy, it is included in the broadcast signal transmitted from one transmission source. Compared to the case where the time information is corrected based on the single time information, the time information can be corrected with higher accuracy.

  Further, in the present invention, the time information review unit calculates a tuning time difference between each tuning time after the tuning time when the first tuning is performed, and is included in each broadcast signal. By subtracting the channel selection time difference from the time information, time information included in each broadcast signal at the channel selection time when the first channel selection is performed is generated.

  By doing in this way, the time information according to each transmission source in a specific same time can be generated.

  Further, in the present invention, the time information verification unit verifies whether or not there is time information having the largest number of information among the time information examined by the time information examination unit. If it is not the most accurate time information, if not clearly different time information is excluded from the verification target, the average value of the time information of the verification target is calculated, the time information is close to this average value, and the time information The time information with the largest number is derived as the time information with the highest accuracy.

  By doing in this way, even when there is no time information with the largest number of information in the time information examined by the time information examination unit, it is possible to derive the time information with the highest accuracy.

  According to the present invention, by extracting a plurality of time information included in a broadcast signal received by a digital broadcast receiver, time information with the highest accuracy is derived from the extracted time information, and the derived time information is included in the derived time information. Based on this, the time information of the clock unit provided in the receiver can be accurately corrected.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing an example of a system configured using a digital broadcast receiver according to the present invention.
In the figure, 5 is an antenna for receiving radio waves of digital broadcasting, 100 is a video signal, an audio signal, and a data signal extracted from a broadcast signal included in the radio wave received by the antenna 5, and for each extracted signal A digital broadcast receiver 11 that performs signal processing is connected to the digital broadcast receiver 100, receives a video signal that has undergone image processing or a data signal that has undergone data processing in the digital broadcast receiver 100, and receives video or data LCD (Liquid Crystal Display) 13 is a speaker that is connected to the digital broadcast receiver 100, receives an audio signal processed by the digital broadcast receiver 100, and outputs audio.

FIG. 2 is a diagram illustrating a configuration of a broadcast signal received by the digital broadcast receiver 100.
In the figure, reference numeral 21 denotes a broadcast signal received by the digital broadcast receiver 100, which handles individual streams such as video, audio, and data in a common signal format and is a multiplexed signal (hereinafter referred to as TS and TS). (Abbreviated), 22 is a transport packet (hereinafter abbreviated as TS packet) constituting TS21, 23 to 25 are individual streams included in each TS packet 22, 23 is a video stream, 24 is an audio stream, 25 Is a data stream.

The video stream 23 is composed of a packet header 26 and video information 27, and the packet header 26 includes a packet identifier (not shown) indicating the type of each packet.
Similarly, the audio stream 24 includes a packet header 26 and audio information 28, and the data stream 25 includes a packet header 26 and data information 29.
The data information 29 includes various information 30 such as time information and program information.

FIG. 3 is a block diagram showing an example of a digital broadcast receiver according to the present invention.
In FIG. 3, the same or corresponding parts as those in FIG.
In the figure, 1 is a microprocessor that controls the entire digital broadcast receiver 100, 2 is a power supply unit that supplies power to each unit in the digital broadcast receiver 100, and 3 is time information management in the digital broadcast receiver 100. Clock unit 4 is a timer that outputs the arrival fact in the form of a signal when the set time arrives based on the time information of clock unit 3, and 6 is a digital broadcast to be received selected from a plurality of transmission sources. A tuning unit for stationing, a tuner for receiving a digital broadcast broadcast signal selected by the channel selection unit via an antenna 5, 8 for a demodulating unit for demodulating the broadcast signal received by the tuner 7, and 9 for demodulation A TS signal processing unit for extracting a video signal, an audio signal, and a data signal from the transport stream signal (hereinafter abbreviated as a TS signal) demodulated by the unit 8.

In the video signal processing unit 10, image processing is performed on the video signal extracted from the TS signal by the TS signal processing unit 9, and the video signal subjected to the image processing is displayed on the LCD 11 connected to the digital broadcast receiver 100. Is output.
Similarly, the audio signal processing unit 12 performs audio processing on the audio signal extracted from the TS signal by the TS signal processing unit 9, and the audio signal subjected to the audio processing is sent to the digital broadcast receiver 100. It is output to the connected speaker 13.
The data signal processing unit 14 extracts time information and other information from the data signal extracted from the TS signal by the TS signal processing unit 9.

The time information extracted by the data signal processing unit 14 is scrutinized by the time information scrutiny unit 16, and time information after scrutiny is generated based on the scrutiny result.
Then, the time information after the scrutiny is verified by the verification means in the time information verification unit 17, and the accuracy of the time information is verified, and the time information with the highest accuracy is derived.
Furthermore, the time information required to derive the time information is added to the derived time information to generate correction time information. Based on the generated correction time information, the time information of the clock unit 3 Make corrections.
Details of the examination and verification will be described later.

  FIG. 4 is a flowchart showing a time information correction procedure in the digital broadcast receiver 100 described above.

In step S1, the time for correcting the time information of the clock unit 3 is set.
Each setting item at the time of setting is displayed on the LCD 11, for example, as shown in FIG.
Here, in order to correct time information using the present invention, it is necessary to receive a plurality of TS signals by selecting a plurality of channels and extract time information contained in each TS signal. .
For this reason, it is better to select a time zone (for example, 3:30 am) where the possibility of viewing is low as the time zone to be set.

  In step S2, a signal indicating the arrival fact is output from the timer 4 when the time set in step S1 arrives.

  In step S3, the channel selection unit 6 is activated along with the signal output in step S2, and the channel selection unit 6 performs channel selection for all receivable channels.

  In step S4, extraction processing is performed on each TS signal obtained by channel selection in step S3, and thereby a video signal, an audio signal, and a data signal are extracted from each TS signal in step S5.

  In step S6, further extraction processing is performed on all of the data signals extracted in step S5, whereby time information and other information are extracted from all data signals in step S7.

  In step S8, the time information review unit 16 examines the time information for all the time information extracted in step S7, and generates time information after the examination.

  In step S9, the accuracy of the time information is verified by the time information verification unit 17 for all the time information after the scrutiny generated in step S8, and the time information with the highest accuracy is derived.

In step S10, the time information of the clock unit 3 is corrected based on the most accurate time information obtained by the time information verification unit 17.
Specifically, first, the verification time from the start of channel selection by the channel selection unit 6 to the end of all verifications by the time verification unit 17 is calculated, and then, at the calculated verification time, in step S9. The corrected time information is generated by adding the derived time information with the highest accuracy, and finally, the generated correction time information is set as time information (current time) of the clock unit 3. That is, the current time is corrected by rewriting the time information of the clock unit 3 to the correction time information.

FIG. 6 is a diagram for explaining the detailed examination of time information in the present invention. As an example, a detailed examination example when channel selection of 15 different channels is performed.
In the figure, 31 is a selected channel, 32 is a channel selection time when channel selection is performed for each of 15 channels, and 33 is a channel selection after the channel selection time 32 when the first channel selection is performed. Channel selection time difference between time 32, 34 is each TS obtained by channel selection, 35 is time information included in each TS obtained by channel selection, and is examined Previous time information before scrutiny 36 is time information after scrutiny generated by performing scrutiny on the time information 35 before scrutiny.

  Here, the scrutiny in this embodiment refers to tuning of 15 different channels simultaneously (at the same time) by subtracting each tuning time difference 33 from the time information 35 before scrutiny included in each TS signal. In this case, the time information included in each TS signal is generated.

For example, in FIG. 6, the channel selection time 32 when channel 1 channel selection is started is based on the time information standard of the clock unit 3 provided in the digital broadcast receiver as “February 3, 2007, 4:05:54. The time information 35 before scrutiny included in the reference destination TS34 “TS01” is “February 3, 2007, 4: 5: 55”.
In this case, the channel selection time difference 33 does not exist because it is the channel selection start time, and the post-scrutiny time information 36 is “February 3, 2007, 4: 5: 55”.
In the same manner, for example, the reference TS34 in the channel selection time 32 “February 3, 2007, 4: 6: 12” when the channel 10 is selected is included in “TS10” and “TS10”. The time information 35 before scrutiny is “February 3, 2007, 4: 6: 15”.
At this time, the channel selection time difference 33 from the start of channel selection is “18 seconds”, so the post-scrutiny time information 36 is “February 3, 2007, 4: 5: 57”.

FIG. 7A is a diagram for explaining the verification of time information in the present invention in detail.
In the figure, 51 is the time information after scrutiny in which the post-scrutiny time information 36 in FIG. 6 is itemized by time information, and 52 is the number of time information corresponding to each item of each scrutiny time information 51.

In the case of FIG. 7A, the most time information after the scrutiny is “February 3, 2007, 4: 5: 55”, which has five pieces of time information.
As a result, it can be said that the time information with the highest accuracy in the time information after scrutiny is “February 3, 2007, 4: 5: 55”. Based on this time information, the time information of the clock unit 3 Perform the correction.

  However, in the case of FIG. 7B, since there are a total of six items of post-scrutiny time information 53 that holds two pieces of time information number 54, time information with the highest accuracy is immediately derived as in the case of FIG. 7A described above. It is not possible.

In this case, firstly, clearly different time information, in FIG. 7B, “February 3, 2007, 16: 5: 55” and “February 4, 2007, 4: 5: 55” Are excluded from the verification target, and an average value is calculated for the remaining time information of the verification target.
By this calculation, the average value in FIG. 7B becomes “February 3, 2007, 4: 5: 55”.

Next, the time information of the item having the largest number of time information, which is the time information of the item close to the calculated average value, is verified.
The time information that satisfies this condition is “February 3, 2007, 4: 5: 55” in FIG. 7B.

  Based on the above calculation and verification, the time information with the highest accuracy is “February 3, 2007, 4: 5: 55”, and the time information of the clock unit 3 is corrected based on this time information. .

  Therefore, the verification in the present embodiment first verifies whether or not there is an item with the largest number of time information items in the post-scrutiny time information item, and if there is one (FIG. 7A), If the time information is the most accurate time information and there is no time information (FIG. 7B), first, the time information that is clearly different is first excluded from the verification target, and then the average value of the time information to be verified is calculated. Finally, it is to derive the time information of the item that is close to the average value and has the largest number of pieces of time information as the time information with the highest accuracy.

As described above, in the above-described embodiment of the present invention, when the time information correction time set in advance by the user arrives, the channel selection unit 6 performs channel selection and selection. It is possible to derive the time information with the highest accuracy by verifying the time information verifying unit 17 after verifying the plurality of time information included in the TS signal obtained by the station by the time information verifying unit 16. it can.
For this reason, it is possible to accurately correct the time information of the clock unit 3 with accurate time information.

  In the present invention, various embodiments other than those described above can be adopted. For example, in the above embodiment, the average value of the time information is calculated as an example of the verification method, but a calculation method such as standard deviation may be used.

  Further, in the above-described embodiment, all the time information obtained by channel selection has been scrutinized and verified. However, a predetermined number of time information may be scrutinized and verified.

  In the above embodiment, the digital broadcast receiver 100 is taken up as a single unit, but the digital broadcast receiver of the present invention is incorporated in a main video device or sub-video device such as a television receiver or STB (Set Top Box). It is also possible.

  Further, in the present invention, correction time information for correcting time information of the clock unit is simultaneously transmitted to a device connected to the digital broadcast receiver and provided with the clock unit. Even time information of all connected devices can be corrected.

It is the figure which showed an example of the system comprised using the digital broadcast receiver which concerns on this invention. It is a figure which shows the structure of the broadcast signal in digital broadcasting. It is the block diagram which showed an example of the digital broadcast receiver which concerns on this invention. It is the flowchart which showed the correction | amendment procedure of time information. It is the figure which showed an example of the setting screen displayed at the time of the setting of time information correction. It is a figure for explaining the detailed examination of time information in detail. It is a figure for explaining verification of time information in detail. It is a figure for explaining verification of time information in detail.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Clock part 4 Timer 6 Channel selection part 9 TS signal processing part 14 Data signal processing part 16 Time information examination part 17 Time information verification part 21 Transport stream 29 Data information 100 Digital broadcast receiver

Claims (3)

A channel selection unit for selecting a digital broadcast received from a plurality of transmission sources;
A tuner for receiving a broadcast signal of a digital broadcast selected by the channel selection unit;
A demodulator for demodulating the broadcast signal received by the tuner;
A broadcast signal processing unit for extracting a video signal, an audio signal, and a data signal included in the broadcast signal demodulated by the demodulation unit;
In a digital broadcast receiver equipped with
A time information scrutinizing unit for scrutinizing time information included in the data signal extracted by the broadcast signal processing unit;
A time information verification unit for verifying the accuracy of the time information scrutinized by the time information review unit;
And a clock unit for managing time information,
Based on the time information of the clock unit, when a time for correcting the time information of the clock unit arrives, a plurality of digital broadcasts that can be received by the channel selection unit are selected, and the broadcast signal processing unit selects the digital broadcast. Extract time information from multiple broadcast signals obtained by the station,
The time information of the clock unit is corrected based on time information having the highest accuracy among a plurality of time information extracted by the broadcast signal processing unit and verified by the time information verification unit. Broadcast receiver. The digital broadcast receiver according to claim 1, wherein
The time information scrutiny unit calculates a channel selection time difference between each channel selection time after the channel selection time when the first channel selection is performed, and subtracts the channel selection time difference from the time information. A digital broadcast receiver characterized in that time information included in each of the broadcast signals is generated at a channel selection time when the first channel selection is performed. The digital broadcast receiver according to claim 1 or 2,
The time information verification unit verifies whether or not there is time information having the largest number of information among the time information examined by the time information examination unit. If there is, the time information verification unit has the highest accuracy. If it is not time information, if the time information that is clearly different is excluded from the verification target, the average value of the time information to be verified is calculated, the time information is close to this average value, and the number of time information is the largest A digital broadcast receiver characterized by deriving time information as time information having the highest accuracy.

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