JPH0877764A - Automatic clock correcting method - Google Patents

Abstract

PURPOSE: To automatize the time correcting processing of a clock by storing time difference data with a world standard time and performing a control with a microcomputer based on an EDS signal. CONSTITUTION: Initialization processing of a microcomputer 6, etc., are performed by energizing a receiver. Next, the computer 6 inputs and processes EDS data from an EDS extracting circuit 5. The microcomputer 6 judges the presence or absence of time data including the world standard time in the EDS signal. At the time of only the world standard time, a clock built-in the receiver is corrected by seeing a display part 9 while operating an operation part 8. Consequently, the time difference data are automatically stored in a memory 7. When the time difference data are present in the EDS signal, the time difference information are automatically stored in the memory 7 and then an initialization is completed. Time corrections are automatically performed by periodically generated clock correction requirements. The correction is performed by a processing in which the microcomputer 6 processes the time difference data of the EDS data extracted by the EDS extracting circuit 5 based on the time difference data of the memory 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for automatically correcting an error generated in a clock incorporated in a receiver such as a magnetic recording / reproducing apparatus.

[0002]

2. Description of the Related Art In recent years, VTRs (video tape recorders) have been put on the market in which an error generated in a built-in clock is automatically corrected by a time signal from a broadcasting station.

[0003]

Recently, there are receivers which try to adjust the time by using the time data sent from the broadcasting station, but the time is adjusted considering the regional error. There is nothing to do.

[0004]

SUMMARY OF THE INVENTION According to the present invention, the data of the world standard time, the standard time of the world standard time and the standard time of the receiver installation area receiving the television broadcast are provided within the vertical blanking period of the television signal. In a receiver adapted to perform time adjustment by receiving time difference data, the time difference data is stored in a memory, and when the time error of the built-in clock is corrected, the television signal may be transmitted only in world standard time. An automatic time adjustment method for adjusting the time of the standard time of the area where the receiver is installed by using the time difference data stored in advance in the memory for the data of the world standard time.

[0005]

When the clock is corrected and the signal from the broadcasting station does not have time difference information, the time difference information stored in advance at the time of initialization is used for correction.

[0006]

An embodiment of the present invention will be described below with reference to the drawings.

In the United States, some broadcasting stations use EDS (E
A signal called an "xtened Data Services" signal is transmitted while being superimposed on the 21st line of the vertical blanking period of the second field of the television signal.

In the EDS signal, the name of the broadcasting station that is broadcasting, the current date, the day of the week, the hour, and the minute data (this time data is Greenwich Mean Time, and the second data is specially transmitted). Not sent, but sent a signal indicating the 00 second time point of each minute, that is, the time point when each minute changed),
The time difference data and the like are included, and regarding the time difference data, only one affiliated broadcasting station at present has a transmission service.

FIG. 1 is a block diagram of a main circuit of a VTR embodying the present invention, and FIGS. 2 and 3 are flow charts for explaining a time correction method according to the present invention. A television signal caught by an antenna 1 is shown. Is received and selected by the tuner 2, supplied to the signal processing circuit 3, where the video and audio signals are processed and recorded by the recording / reproducing circuit 4.

On the other hand, the signal output from the tuner 2 is E
It is also supplied to the DS signal extraction circuit 5, but this extraction circuit 5
Is an ED transmitted by being superimposed on the 21st line of the vertical blanking period of the second field of the television signal.
Extract the S signal. The EDS signal extracted by the EDS signal extraction circuit 5 is supplied to the microcomputer (microcomputer) 5 and the signal is decoded. The microcomputer 5 also operates as a tuning microcomputer that also controls the tuner 2. Reference numeral 7 is a memory for storing various data including time difference data, which will be described later, 8 is an operation unit for the user to input necessary information, and 9 is a display unit for displaying time and the like. It is an on-screen display on the screen of a fluorescent display tube or a television receiver.

First, when the user first purchases the VTR or sets the clock when the VTR is newly installed by moving or the like, when the VTR is first operated as shown in the flowchart of FIG. 2 (S1), the microcomputer is activated. After initialization processing such as (S2), E from the EDS extraction circuit 5
The microcomputer 6 receives the DS data and processes it (S3).

When it is determined that the EDS signal includes time data including Greenwich Mean Time (World Standard Time) (S4), it is further determined whether there is time difference data (S5). As mentioned above, except for one broadcasting station, other broadcasting stations transmit time data but not time difference data.If there is no time difference data, only the standard time of Greenwich is known, and the manual operation of the user is not possible. The VTR's built-in clock must be modified accordingly. Therefore, the screen for time adjustment is displayed on-screen (S6). While watching it, the user corrects the current time by inputting the standard time of the area where the user is, by using the telephone time signal service or the like by operating the operation unit (S7). By this correction by the user, the time difference information is automatically stored in the time difference data memory (S8), and the initial setting process ends (S9).

In the process of step 5 (S5), if the EDS data has time difference data, the data is stored in the time difference data memory (S8), and the initialization process ends (S9). In this way, the time difference data is obtained manually or automatically at the time of initial setting, and if the time difference data is present in the EDS signal, the standard time in the area where the VTR is installed is automatically set based on it. . If Greenwich Mean Time and the time difference from that standard time are known, it will be easy to understand that the local standard time is required. For example, Japan time is 9 hours earlier than Greenwich Mean Time.

As described above, after the initial setting of the VTR clock, an error occurs in the VTR clock several days after the initial setting, so that it is necessary to correct it. This correction is automatically performed by a time correction request that occurs regularly (every other week, for example). This automatic correction is performed using the time data of the EDS data, but in the present invention, even if the EDS data does not include the time difference data at the time of the periodic time correction, that is, a broadcasting station having no time difference data is selected. Even when a channel is selected, the current time can be corrected using the time difference data stored at the time of initial setting.

This point will be described with reference to the flowchart of FIG.

First, when this processing is started in step 1 (S11), initialization processing of the microcomputer etc. is first performed (S1).
2) If the time adjustment request is generated, for example, one week after the initial setting of the time (S13), the process proceeds to the next step 14 (S14), but if the time adjustment request is not issued, the process is directly performed. It ends (S20).

If there is a time correction request in step 13, the microcomputer receives the EDS data and processes it (S1).
4). When it is determined that there is time data including Greenwich Mean Time (S15), it is next determined whether there is time difference data (S16). If it is determined in step 16 that there is time difference data, the current time is decoded and corrected in step 18, and the process ends (S1).
9).

On the other hand, if it is determined in step 16 that there is no time difference data, the time difference data stored in the memory at the time of the above initialization is read out, and the current time is calculated based on this time difference data and the currently received Greenwich Mean Time. The process proceeds to step 18 (S18) so as to be decoded, the current time is decoded as in the previous case (S18), and the process ends (S18).
19).

[0019]

As described above, according to the present invention, time adjustment is preferably performed in consideration of the time difference even if the time difference information is not sent from the broadcasting station at the time adjustment.

[Brief description of drawings]

FIG. 1 is a block diagram of an essential part of a video tape recorder embodying the present invention.

FIG. 2 is a diagram showing a flowchart showing a procedure of initial setting of time.

FIG. 3 is a diagram showing a flowchart showing a procedure of time adjustment.

[Explanation of symbols]

 1 Antenna 2 Tuner 3 Signal Processing Circuit 4 Recording / Reproducing Circuit 5 EDS Signal Extraction Circuit 6 Microcomputer 7 Memory 8 Operation Section 9 Display Section

Claims (3)

[Claims] 1. The reception of world standard time data and time difference data between the world standard time and the standard time of a receiver installation area receiving the television signal is possible within a vertical blanking period of the television signal. In the receiver, the time difference data is stored in the memory in advance by the user at the time of initial setting of the time when the receiver is installed, and the television signal is transmitted only in the world standard time when the time error of the built-in clock of the receiver is corrected. Even if it has not been done, an automatic time correction method for adjusting the time of the standard time of the area where the receiver is installed by using the time difference data stored in advance in the memory for the data of the world standard time. 2. The automatic clock correcting method according to claim 1, wherein the receiver is a video tape recorder. 3. The on-screen display screen shifts to a clock correction screen when the user does not have the time difference data at the time of initial setting of the time when the receiver is installed and the time difference data is stored in the memory according to claim 1. Automatic clock correction method characterized by.