JP3288788B2 - clock - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a timepiece which receives a time signal and corrects the time.

[0002]

2. Description of the Related Art A conventional clock which receives a time signal of a radio broadcast and corrects the time, for example, once a month at the end of a month.
In a timepiece that receives a time signal at 3:00 and corrects the time, the time range for receiving the time signal is fixed so that the time measured by the internal clock is 2:30, that is, ± 30 seconds.

[0003]

However, in the above-mentioned apparatus, since the time signal reception time range is fixed, for example, when the accuracy of the clock is poor and the time signal cannot be received continuously due to noise or the like, The error of the internal clock accumulates, and the measured time deviates from the actual time by 30 seconds or more.
There is a problem that the time signal cannot be received within the reception time.

[0004] It is an object of the present invention to reliably receive a time signal and perform timing.

[0005]

According to the present invention, there is provided a receiving means for receiving a time signal at a desired time, a time clock unit which is timed by inputting the time signal, and measures time. Time measuring means for measuring the time elapsed since the time adjustment, and the receiving start time and the receiving end time of the receiving means based on the value of the time measuring means and the timing accuracy of the time clock unit.
The above object is achieved by providing a control means for deciding and operating the receiving means when the time counted by the time measuring unit corresponds to the reception start time.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to one embodiment shown in the drawings.

In FIG. 1, reference numeral 1 denotes a receiving means, which comprises an antenna 2 and a receiving circuit 3, and receives and outputs, for example, a time signal of the first NHK broadcast. AM2: 0 on the 5th of every month
It is set to receive a time signal of 0. Reference numeral 4 denotes a time display unit which displays the current time with hands 5 and is timed at 2:00 by a time signal output from the receiving circuit 3. Reference numeral 6 denotes an integrating counter which constitutes a time measuring means, and measures the elapsed time from the last time adjustment of the time display unit 4. Reference numeral 7 denotes a control circuit which constitutes control means, and includes a CPU, a ROM, a RAM,
It comprises a crystal oscillator, a frequency divider and the like, has an internal clock (time clock section) having calendar information, and controls various operations. Reference numerals 8 and 9 denote batteries. The battery 8 is attached in the manufacturing process of the timepiece and supplies power to the integrating counter 6 and the control circuit 7. The battery 9 is inserted by the user when using the timepiece, and supplies power to the receiving circuit 3, the time display unit 4, the integrating counter 6, and the control circuit 7. Reference numeral 10 denotes a voltage detection circuit that detects the insertion of the battery 9. 11 and 12 are diodes.

Next, the operation when the battery 9 is inserted will be described with reference to FIG.

At the time of shipment from the factory, a time adjustment signal output from a time setting circuit (not shown) on the production line is input to a terminal A of the main clock in which the battery 8 is inserted, thereby controlling the time. The internal clock of the circuit 7 is timed, and the internal clock starts measuring the current time, and resets the integrating counter 6 to “0” to start counting. At this time, since the control circuit 7 does not output the drive signal to the time display unit 4, the time display unit 4 does not display the current time.

As described above, since the internal battery 8 is inserted at the time of shipment from the factory and the internal clock is adjusted to the current time, a troublesome time adjustment operation is not required when the user purchases the main clock.

When the user purchases the timepiece and inserts the battery 9 (step 2a), the voltage detection circuit 10 generates a detection output to the control circuit 7.

The control circuit 7 outputs a fast-forward drive signal for the hands 5 in response to the input of the detection output from the voltage detection circuit 10, and matches the display time of the time display section 4 with the clock time of the internal clock of the control circuit 7. (Step 2b). After the time displayed on the time display unit 4 and the time measured by the internal clock of the control circuit 7 match, normal hand movement is performed.

After the time coincidence is detected, the control circuit 7 reads the count value of the integrating counter 6 (elapsed time since the time was adjusted at the time of factory shipment) (step 2c).
According to the read count value and the accuracy of the crystal oscillator in the control circuit 7, the read count value is proportional to the read count value.
Next, a reception start time and a reception end time for a time signal to be received are set, and the set reception start time and reception end time are stored in the RAM in the control circuit 7 (step 2d).

As an example of setting the reception start time and the reception end time, for example, when the accuracy of the internal clock by the crystal oscillator in the control circuit 7 is about ± 20 seconds per month, the count value of the integrating counter 6 is set to x (Day), the reception start time and the reception end time are “AM 2.00-20 seconds × x / 3
0 "," AM 2: 00 + 20 seconds × x / 30 ", and if the count value of the integrating counter 6 is one month (x = 30 days), the reception start time and the reception end time become" AM 2.00-
20 seconds "and" AM 2: 00 + 20 seconds. "Thereafter, as the count value of the integrating counter 6 becomes two months, three months,..., The reception start time and the reception end time become" AM2:
00 ± 40 seconds ”,“ AM 2: 00 ± 60 seconds ”, and so on.

Then, five days are counted by the internal clock of the control circuit 7, and when the counted time reaches the reception start time stored in the RAM of the control circuit 7 (step 2e), the control circuit 7 resets the reception circuit 3 Operate (step 2f).

When the receiving circuit 3 receives the time signal of 2:00 AM (step 2g), the internal clock of the control circuit 7 is set to A.
M: 2:00 (step 2h), the accumulation counter 6 is cleared (step 2i), and the display time of the time display unit 4 is corrected to 2:00 (step 2j).

When the correction of the display time on the time display section 4 is completed, the operation of the receiving circuit 3 is stopped (step 2k), and the operation is ended.

When the reception circuit 3 does not receive the time signal by the reception end time (steps 2g and 2m), the operation of the reception circuit 3 is stopped as described above. In this case, the count of the integrating counter 6 continues without being reset.

Next, the operation during normal hand movement will be described with reference to FIG.

The internal clock of the control circuit 7 is AM2: 0 on the 5th.
One hour before 0, that is, at 1:00 AM (step 3a), the control circuit 7 reads the count value of the integrating counter 6 (step 3b), and the read count value and the crystal oscillator in the control circuit 7 as described above. Depending on the accuracy of
Next, the reception start time and the reception end time for the time signal to be received are set, and the set reception start time and reception end time are stored in the RAM in the control circuit 7 (step 3c). When the time counted by the internal clock of the control circuit 7 reaches the reception start time stored in the RAM of the control circuit 7 (step 3d), the control circuit 7 operates the reception circuit 3 (step 3e).

Hereinafter, the same operation as described above is performed.

As described above, since the receiving time for receiving the time signal is changed in proportion to the accuracy of the crystal oscillator in the control circuit 7 and the count value of the integrating counter 6, the time signal can be reliably received. Time can be adjusted accurately.

For example, when the time signal cannot be received, the count value of the integrating counter 6 becomes large and the receiving time becomes long, so that the accumulated error can be covered and the time signal can be reliably received. be able to.

In the above description, the reception start time and the reception end time are extended by 20 seconds each time the count value of the integrating counter 6 elapses one month. However, the accuracy of the crystal oscillator in the control circuit 7 is increased. It can be changed as needed. For example, when the accuracy of the crystal oscillator in the control circuit 7 is about ± 30 seconds per month, when the integration counter 6 has counted one month, the reception start time is “AM 2: 00-30 seconds” and the reception end time is Is set to “AM 2: 00 + 30 seconds”, and as the count value of the integrating counter 6 becomes 2 months, 3 months,.
0 ± 60 seconds ”,“ AM 2: 00 ± 90 seconds ”,...

In the above description, the time signal of AM 2:00 on the 5th of each month is received. However, the present invention is not limited to the above, and the scheduled reception time, the reception interval, and the like can be appropriately changed.

In the above description, the count value of the integrating counter is read out one hour before the time signal to be received is generated. However, the present invention is not limited to this, and can be changed as appropriate.

[0027]

According to the present invention, the reception start time and the reception end time of the receiving means are determined based on the elapsed time from the previous time adjustment of the time counting unit and the timing accuracy of the time counting unit. Since the receiving means is operated when the time counted by the time counting unit corresponds to the reception start time, the time signal can be reliably received and the timing can be reliably performed. Therefore, accurate time measurement can be performed. Further, it is possible to reduce the receiving operation of the receiving means that is less necessary.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram showing one embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of FIG. 1;

FIG. 3 is a flowchart for explaining the operation of FIG. 1;

[Explanation of symbols]

 1 receiving means 6 timekeeping means 7 control means (time keeping unit)

Claims (1)

(57) [Claims] 1. A receiving means for receiving a time signal at a desired time, a time clock unit which is timed by inputting the time signal and measures time, and an elapsed time from a previous time adjustment of the time clock unit. a counting means for counting, based on the timekeeping accuracy values and the time point measurement of the time measuring means
Hazuki determined <br/> the reception start time and reception end time of said receiving means, the measured time of the time counting portion is equipped with a control means for operating said receiving means upon corresponding to the reception start time A clock characterized by the following.