JPH09284665A - Digital broadcasting receiving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adaptively correct the time of an internal clock device in a receiving device at the digital broadcasting reception. SOLUTION: Multiplex digital data of video data, voice data and time information is supplied from an input terminal 102 to a separating device 103 and video data, voice data and time information are separated. Separated time information is decoded in a system decoder 104. A judging device 106 judges whether or not a present time indicated by decoded time information is in the time period of time correction prohibition, whether or not it is largely deviated from the time indicated by the internal clock device 105 or whether or not it is in the time period of clock correction permission and the time indicated by the internal clock device 105 is corrected, based on time information which is decoded in the system decoder 104 in accordance with the judgement result.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital broadcast signal receiving apparatus, and more particularly, to a clock apparatus provided therein and to correct the clock apparatus based on time information multiplexed in the digital broadcast signal. Digital broadcast receiver.

[0002]

2. Description of the Related Art In place of current analog television broadcasting, digital broadcasting is being started in which broadcasting signals such as digitized video signals and audio signals are transmitted to homes by satellites, cables, terrestrial broadcasting, etc. There is. Some satellite broadcasts in the United States have already been broadcast in this form, and preparations are underway for the launch of similar services in Japan as well.

One feature of digital broadcasting is that it can simultaneously transmit various additional information such as time information indicating the current time and an electronic program guide together with a digitized video signal and audio signal. Even in the current analog television broadcasting, the same service is provided by using the vertical blanking period of the video signal.

For example, Japanese Laid-Open Patent Publication No. 7-307931 discloses that time information multiplexed in a vertical blanking period of a video signal is used.
A method for automatically correcting an internal clock device of a television receiver is disclosed.

FIG. 7 is a block diagram showing such a conventional receiving apparatus. Reference numeral 701 is a television broadcast radio wave (hereinafter,
A TV signal) receiving antenna, 702 a TV signal demodulator, 703 a line input terminal, 704 an input selector, 705 a VBID (vertical blanking interval superimposed signal) demodulator,
Reference numeral 706 is a microcomputer, and 707 is an internal clock device.

In the figure, a TV signal received by the receiving antenna 701 is demodulated by a TV signal demodulator 702 into a baseband video signal and an audio signal, and the video signal is supplied to an input selector 704. During the vertical blanking period of this video signal, additional information such as time information is superimposed as a VBID signal. Also, the input selector 704 is supplied with an output video signal of an external device such as a video tape recorder from the line input terminal 703.

Now, assuming that the input selector 704 selects the output video signal of the TV signal demodulator 702, this video signal is supplied to the VBID demodulator 705, and the VBID signal of this video signal is demodulated. The microcomputer 706 uses this V
The VBID signal demodulated by the BID demodulator 705 extracts the time information, and the internal clock device 707 resets the time to the current time represented by this time information. Thus, the time information superimposed on the TV signal causes reception. The time of the internal clock device of the device can be automatically corrected, and the error such as the time difference corresponding to the receiving area of the receiving device can also be corrected. Such time correction is performed every time time information is multiplexed on the TV signal.

[0008]

By the way, the above-mentioned prior art is excellent as means for automatically setting the time of the internal clock device of the receiving device in analog broadcasting.
However, in digital broadcasting, all the additional information such as the time information is transmitted in the same format, so that there can be no dedicated demodulator for the time setting process. Further, since the microcomputer 706 also controls decoding processing of video data and audio data, it is not possible to process time information with the highest priority, and there are many tasks that perform processing using time information. Therefore, there is a problem that the time cannot be corrected without considering other tasks.

An object of the present invention is to provide a digital broadcast receiving apparatus which solves such a problem and is capable of adaptively correcting the time information managed by the internal clock when the digital broadcast is received.

[0010]

To achieve the above object, the present invention provides at least a separating means for separating data such as video data, audio data and additional information from multiplexed digital data, and the separated addition. A system decoding means for decoding time information representing the current time from the information, an internal time management means for managing the time information, and the internal time management means for managing the time information decoded by the system decoding means. Time correction determination means for determining whether or not to correct the time information is provided.

With this configuration, the time information managed by the internal time management means can be corrected without affecting other operations such as task processing.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In the embodiments described below, information data such as time information to be digitally broadcasted even in a standby state in which power is supplied, for example, by inserting a power outlet and the power switch is not turned on. Is received and decoded.

FIG. 1 is a block diagram showing a first embodiment of a digital broadcast receiving apparatus according to the present invention. 101 is a receiving apparatus, 102 is an input terminal, 103 is a separating apparatus, 10
4 is a system decoder, 105 is an internal clock device, 106
Is a determination device, 107 is a video decoder, 108 is an audio decoder, and 109 and 110 are output terminals.

In the figure, the digital data input to the receiving device 101 from the input terminal 102 is digital video data and audio data in which additional information such as time information is multiplexed, and such digital data is also used. The input digital data is data obtained by digitally demodulating a digital broadcast signal from a broadcast station and performing processing such as error correction.

The input digital data from the input terminal 102 is supplied to the separation device 103 and separated into video data, audio data and additional information. The video data is video decoder 107 and the audio data is audio decoder 1.
Each of the signals is decoded at 08 and output from the output terminals 109 and 110.

The additional information separated by the separating device 103 is supplied to the system decoder 104 and decoded. Of the decoded additional information, the time information indicating the current time is supplied to the determination device 106. on the other hand,
The internal clock device 105 manages time information and represents the time corresponding to this time information (need not necessarily be displayed), and the determination device 106 determines the internal clock device from the time information decoded by the system decoder 104. It is determined whether the time information managed by 105, that is, the time of the internal clock device 105 should be corrected. Then, when it should be corrected, the determination device 106 corrects the time represented by the internal clock device 105 based on the time information decoded by the system decoder 104. The correction of the time information is to set the time represented by the time information decoded by the system decoder 104 in the internal clock device 105.

Here, the digital data input from the input terminal 102 is multiplexed with time information representing the time t at every moment, and the system decoder 104 sequentially decodes the time information.

By the way, when the determination processing in the determination device 106 requires time Δt, the system decoder 10
4, the time Δt has elapsed from the time of receiving the time information from 4 until the determination result that the time of the internal clock device 105 should be corrected is obtained. When this is done, this internal clock device 105
An error of time Δt occurs at the time represented by.

When the time error Δt is a non-negligible error, the decision device 106 controls the system decoder 104 when the decision process is completed, and determines the time information to be decoded at that time or immediately thereafter. Based on this, the time represented by the internal clock device 105 is corrected. The determination device 106 does not perform the above determination process on this time information.

FIG. 2 is a flow chart showing the operation of the determination device 106.

First, when the receiving device 101 is powered on (step 201), the time represented by the internal clock device 105 is corrected based on the time information decoded by the system decoder 104 (step 202). Here, turning on the power includes, for example, a state where the power is supplied to the receiving device 101 through an AC outlet even if the power switch is not turned on (that is, the standby state described above). Then, the process waits until the preset predetermined time a elapses from this time correction (step 20).
3). Also, during the operation after the power is turned on (step 20
1), the process waits until the predetermined time a elapses from the previous time correction of the internal clock device 105 (step 203).
The predetermined time a can be arbitrarily set such as one hour or one day.

When this predetermined time a has elapsed (step 2
03), it is determined whether it is a prohibited time zone of the clock correction (that is, the correction of the time indicated by the internal clock device 105) (step 204). If it is not this prohibited time zone, the system decoder 104 operates as described above. Based on the decoded time information, the time of the internal clock device 105 is corrected (step 205). For example, if the power supply is not stopped by pulling out the AC outlet (step 206), the process returns to step 203.

Here, the clock correction prohibition time b and the time c which determines a predetermined clock correction prohibition time zone including the clock correction prohibition time b are set in the determination device 106, and the step 204 is executed.
Given that the current time t is represented by the time information decoded by the system decoder 104, it is determined whether or not the current time t is within this clock correction prohibited time zone, that is, whether bc <t <b + c. It is a thing. When this is satisfied, the time of internal clock device 105 is not corrected. Note that in step 204 of FIG. 2, | t−b |> c is set, but this is the same as the above inequality.

The time b for which the clock correction is prohibited is set to the receiving device 10
1 is a time at which there is a high possibility that the program will be switched, and is, for example, a 30-minute interval such as 7:00 pm, 7:30 pm, and 8:00 pm. The time c is, for example, one minute. Therefore,
For example, the clock correction prohibited time b is 7:00 pm, and the time is c
Is 1 minute, the time zone in which the time correction of the internal clock device 105 is prohibited is from 6:59 pm to 7: 1 pm
Up to the minute, the time correction of the internal clock device 105 is prohibited in this time zone.

In the receiving device 101, the above-mentioned 7:00 pm
At times such as minutes, 7:30 pm, and 8:00 pm, task processing such as displaying a broadcast program guide and selecting programs is frequently performed. Therefore, by setting the clock correction prohibition time b at intervals of 30 minutes such as 7:00 pm, 7:30 pm, and 8:00 pm, it is possible to avoid a time zone in which the task is frequently processed. The internal clock device 105 can be used to correct the time, and the task processing efficiency of the receiving device 101 can be improved.

Therefore, according to this embodiment, the time correction of the internal clock device 105 is automatically performed, and the processing efficiency of the task executed by the receiving device 101 can be improved.

FIG. 3 is a flow chart showing the operation of the second embodiment of the digital broadcast receiving apparatus according to the present invention. The block configuration of the second embodiment is similar to that of FIG.

In the second embodiment, the difference between the time tc currently represented by the time information managed by the internal clock device 105 and the current time t represented by the time information decoded by the system decoder 104 in FIG. When the preset allowable error time d is exceeded, that is, when the time tc largely deviates from the current time t, the time correction of the internal clock device 105 is performed.

In FIG. 3, after performing the operations of steps 201 and 202 as in the flow chart shown in FIG. 2, the judging device 106 has the present time t of the time information decoded by the system decoder 104 and the internal clock device 105. Is monitored and it is determined whether or not the absolute value | tc-t | of the difference between the times t and tc exceeds the preset allowable error time d (step 30).
3) When this is exceeded, as shown in the flowchart of FIG. 2, the time of the internal clock device 105 is corrected (step 205) in a time zone other than the time zone where clock correction is prohibited (step 204).

That is, in the second embodiment, the operation of step 303 is performed instead of step 203 in FIG.

As described above, according to the second embodiment, when the time error represented by the internal timepiece device 105 becomes larger than the allowable error time d, the internal timepiece device 1 is automatically operated.
Time correction of 05 is performed. Therefore, the internal clock device 1
05 can always accurately represent the actual time t within the error tolerance time d. The allowable error time d can be set to, for example, 5 seconds, but it is clear that it is not limited to this.

FIG. 4 is a flow chart showing the operation of the third embodiment of the digital broadcast receiving apparatus according to the present invention. The block configuration of the third embodiment is similar to that of FIG.

Contrary to the case of FIG. 2, the third embodiment is such that the time of the internal clock device 105 is corrected in a certain set time zone, and as shown in FIG. In FIG. 2, the operation of step 404 is performed instead of step 204.

In FIG. 1, the determination device 105 is preset with a clock correction time e and a time correction permissible time f which determine a time zone in which the receiving device 101 is supposed to perform less task.

In FIG. 4, as in the flow chart of FIG. 2, steps 201, 202 and 203 are executed, and when a predetermined time a has elapsed from the previous time correction in the internal clock device 105, the determination device 106 causes the system decoder 104 It is determined whether or not the absolute value | t−e | of the difference between the current time t represented by the time information decoded by the above and the clock correction time e is within the time correction permissible time f (step 40).
4) When the time is within the time correction allowable time f, the time correction of the internal clock device 105 is executed (step 205).

Therefore, assuming that the time when the task processing is small is, for example, 4:00 am, and this is set as the clock correction time e, and the time correction permissible time f is, for example, 5 minutes, The time during which the time correction of the internal clock device 105 can be executed in the above step 404 is 3: 5 am
It will be from 5 minutes to 4:05 am. At this time,
If the predetermined time a in step 203 is one day, 1
The time of the internal clock device 105 is corrected once a day around 4 am.

Therefore, in the third embodiment, the clock correction time e is set to a time when the task processing of the receiving device 101 is small, so that the time of the internal clock device 105 is avoided while avoiding a time zone in which the task is frequently executed. Correction can be performed, and the processing efficiency of the task of the receiving device 101 can be improved.

Although the time correction is performed once a day here, the time correction may be performed a plurality of times a day in the same manner if the time zone in which the processing frequency of the task is high can be avoided. You can also choose to do so.

FIG. 5 is a block diagram showing a fourth embodiment of the digital broadcast receiving apparatus according to the present invention.
1 to 514 are tasks, and 511 is a control device, and the description of the parts corresponding to those in FIG.

In the figure, the control device 511 is, for example, a task 5 for decoding the video decoder 107.
12 and, for example, a task 513 for controlling the synchronization of the video decoder 107 and the audio decoder 108, for example, a task for decoding the audio decoder 108, respectively, and also includes a determination device 106.

FIG. 6 is a flow chart showing the operation of the judgment device 106 in the control device 511 in FIG.

In the fourth embodiment, these tasks 51
2, 513, 514 are not executed, the determination device 106 performs the above processing. As shown in FIG. 6, step 204 in FIG.
Instead of the above, the operation of step 606 is performed.

That is, in FIG. 6, similarly to the flow chart shown in FIG. 2, when the steps 201, 202 and 203 are executed and the predetermined time a has passed from the previous time correction in the internal clock device 105, the determination device 106 Task 512,
It is determined whether 513 and 514 are being executed (step 6).
06). Then, these tasks 512, 513, 514
If any of the tasks 512, 513, and 514 is not executed, the time correction of the internal clock device 105 is executed (step 205).

As described above, in the fourth embodiment, when a task that performs processing using time information is being executed or a task having a high priority is being executed,
The time correction of the internal clock device 105 can be adaptively performed without disturbing the processing.

[0045]

As described above, according to the present invention,
When the digital broadcast is received, the time information managed by the internal clock device can be adaptively corrected according to other control processing situations such as the execution status of the receiving apparatus internal task, so that it has a special effect on other control processing. Since the time information is corrected without giving the time information, the time represented by the time information can always be matched with the current time with extremely high accuracy, and the control efficiency such as task processing can be improved. it can.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a digital broadcast receiving apparatus according to the present invention.

FIG. 2 is a flowchart showing the operation of the determination device in FIG.

FIG. 3 is a flowchart showing the operation of the determination device in the second embodiment of the digital broadcast receiving device according to the present invention.

FIG. 4 is a flowchart showing an operation of a determination device in the third embodiment of the digital broadcast receiving device according to the present invention.

FIG. 5 is a block diagram showing a fourth embodiment of a digital broadcast receiving apparatus according to the present invention.

FIG. 6 is a flowchart showing an operation of the determination device in FIG.

FIG. 7 is a block diagram showing an example of a conventional broadcast receiving apparatus.

[Explanation of symbols]

 101 Receiver 102 Digital Data Input Terminal 103 Separator 104 System Decoder 105 Clock 106 Judgment Device 107 Video Decoder 108 Audio Decoder 109 Video Data Output Terminal 110 Audio Data Output Terminal 511 Controller 512-514 Task C Processing Means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Satoshi Takashimizu Satoshi Takashimizu 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi, Ltd. Multimedia system development headquarters (72) Inventor Masaru Nagiki Totsuka-ku, Yokohama-shi, Kanagawa 292 Yoshidacho, Hitachi, Ltd., Multimedia Systems Development Headquarters (72) Inventor Satoshi Imuro, 292, Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Prefecture Hitachi, Ltd. Multimedia Systems Development Headquarters (72) Inventor, Shigeru Yoneda 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa, Ltd. Hitachi, Ltd. multimedia system development headquarters (72) Inventor Shigeto Ojo 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi, Ltd. multimedia system development headquarters (72) Inventor Yasutoshi Ito Kanagawa Hama City Totsuka-ku, Yoshida-cho, 292 address Co., Ltd., Hitachi video information media business unit

Claims (5)

[Claims] 1. A digital broadcast receiving apparatus for receiving digital data obtained by multiplexing digitalized video data, audio data, information data including at least time information indicating the current time, and the like. Separation means for separating the information data, decoding means for decoding the time information of the separated information data, internal time management means for managing time information, and internal means using the decoded time information. A time correction determination unit that determines whether or not to correct the time information managed by the time management unit, and the time information managed by the internal time management unit according to the determination result of the time correction determination unit. A digital broadcast receiving apparatus characterized by performing correction of. 2. The time correction determination means according to claim 1, wherein the specific time T0, T1 ,.
Tn (n is 0 or a positive integer) and the time ranges ΔT00, ΔT01, ΔT10, ΔT11, ...
Tn0 and ΔTn1 are predetermined, and the current time t represented by the time information is T0−ΔT00 ≦ t ≦ T0 + ΔT01 T1−ΔT10 ≦ t ≦ T1 + ΔT11 …………………………………………… ………………………………………… When the time zone is other than Tn−ΔTn0 ≦ t ≦ Tn + ΔTn1, the time information managed by the internal time management means is corrected. Digital broadcasting receiver. 3. The time correction determination means according to claim 1, wherein a difference between a current time t represented by the time information and a time ts currently represented by the time information managed by the internal time management means is allowed. The value α is predetermined, and when the absolute value of the difference between the times t and ts is larger than the allowable error time α, the time ts of the internal time management means is corrected, and the digital broadcasting is characterized. Receiver. 4. The specific time T and time range Δ according to claim 1,
The number of sets of T0 and ΔT1 is m (where m is an integer of 1 or more), and the current time t represented by the time information is predetermined.
Is a time zone satisfying T-ΔT0 ≦ t ≦ T + ΔT1, the digital broadcast receiving apparatus is characterized in that the time information managed by the internal time management means is corrected. 5. The control means for executing a plurality of tasks according to claim 1, wherein a part of the control means is the time correction determination means, and the time correction determination means makes the determination based on the execution status of each of the tasks. A digital broadcast receiving apparatus characterized by performing.