JPH1114775A - Method for automatically correcting display time of electronic clock - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize the lunar equation to reduce the frequency of time correction by a purchaser by containing a program for periodically correcting the display time on the basis of the hysteresis of the time correction by, a producer or purchaser itself or a correction value calculated by the oscillating frequency measurement of a reference oscillator. SOLUTION: A program for correcting the time is integrated into the control circuit 1 of an electronic clock. The initial manual 0-reset is performed on the basis of a time signal, and measurement of the accumulated time up to the following manual 0-reset is started. The slippage time (error) between the accumulated time in manual O-reset time and the time signal is recorded. The slippage time from the time signal is divided by the accumulated time to calculate the time slippage per unit time, and the result is recorded. A time correction value corresponding to the time slippage per unit time is inputted into the program. The time correction for the time correction value is performed every period on the program. At a result of correction, the correction value becomes smaller than the slippage time, and the error can be minimized to only the accumulated error within the interval of time correction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for improving the accuracy of display time in a so-called electronic timepiece.

[0002]

2. Description of the Related Art The accuracy of a conventional electronic timepiece depends on the oscillation frequency of an oscillator which serves as a time reference. Occurs.

The general average monthly difference of popular electronic watches is ±
Although it is 15 seconds, the monthly difference must be corrected by the purchaser himself, and the fluctuation of the oscillation frequency of each oscillator remains unchanged, so to maintain the accuracy of the displayed time, it is necessary to manually display The time must be adjusted periodically.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electronic timepiece in which the monthly difference is improved and the frequency of time adjustment by the purchaser himself is reduced.

[0005]

Means for solving the problem In the present invention, a means for solving the problem is based on a history in which the producer or the purchaser himself has set the time or a correction value calculated by measuring the oscillation frequency of the reference oscillator. A program for periodically correcting the display time is built in.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS After the electronic timepiece constructed as described above is produced, the time is adjusted, the elapsed time until the next time adjustment and the time shifted therebetween are calculated, and the shifted time is calculated as the elapsed time. The electronic timepiece is divided to calculate a shift time (error) per unit time, and the time of the calculation result is automatically corrected on a regular basis on a program.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for periodically correcting the time manually set arbitrarily will be described with reference to an embodiment. A program for correcting time in FIG. 1 is incorporated in a control circuit 1 of a conventional electronic timepiece. .

Time a for manual time adjustment
The elapsed time t from the (first time) to the next (second time) time adjustment is calculated, then the time shift c at the time of the second time adjustment is calculated, and the time shift per unit time d = c / t, a correction amount f is calculated from the time shift d per unit time and the correction interval e, and a program for periodically correcting the display time based on the calculation result is provided.

The processing program will be described with reference to FIGS. 1 and 2. The first manual reset 0 is performed based on a time signal (such as a broadcast time signal by telephone), and the accumulation is performed until the next manual reset 0. The measurement of the time t is started.

[0010] The accumulated time t at the time of manual 0 reset b and the deviation time (error) c from the time signal are recorded.

The time lag c from the time signal is divided by the cumulative time t to calculate a time lag d per unit time and record the result. A time correction value f corresponding to the time shift d per unit time is input into the control program.

A time correction of a time correction value f is performed in a cycle e on a program.

By performing the above correction, f <c, and the error is only the accumulated error f within the time correction interval e. If the correction interval e is set short, the accuracy is further improved.

In the case where b = 168 hours and c = -84 seconds, d = -84 seconds / 168 hours = -0.5 seconds / hour. .5
Seconds need to be advanced.

If a reset signal is output by a program and reset by a reset signal 0.5 seconds before every hour on the hour, the display portion of the electronic timepiece is advanced by one, The second is set to 00, and the display time is advanced by 0.5 seconds, which is corrected.

The correction value once set is stored in a register until it is updated next time, and is automatically corrected on a program so as to advance by 0.5 second at every hour.

The frequency of automatic correction can be arbitrarily set by an external switch. In the above example, correction is performed every hour, but it is desirable to select an optimum correction interval according to a correction amount.

Referring to FIG. 3, the method of setting the time error will be described. In FIG. 3, (-) displayed on the display panel surface of (3) indicates a time delay. By pressing this button, the display of +-is alternately repeated, and the * mark is a blinking display of an undecided portion.

Next, by pressing the mode changeover switch (4) once, the process shifts to the setting of the actual error time of 10 seconds, and by pressing the adjust switch (5), the value can be set to a numerical value from 0 to 9. . (3-2) is a display of a state where the setting up to now is completed.

The setting of the one second digit of the actual error time and the accumulated time (h) at the time of calculating the error time can also be set by pressing the mode switch (4) and the adjust switch (5).

FIG. 3 (3-4) shows an example in which the setting of the time error has all been completed. In this case, the error of the electronic timepiece after 24 hours is delayed by 1 second. .

FIG. 4 shows automatic display time correction after setting a time error.
The error after the time indicates that the time was delayed by 1 second, and the error was set to 0 before 1 second immediately before the hour on the 24th hour after the setting of the time error.
The reset indicates that the display time of the electronic timepiece has been advanced by 1 second, and is reset to 0 at the same time when the display time of (4-3) becomes 9: 59.59 (9:59:59). And the display time is set to 10: 00.00 (10:00
0 minutes 00 seconds).

FIG. 5 also shows the automatic display time correction after the setting of the time error. In this case, the error of the electronic timepiece after 24 hours is advanced by one second, and the setting of the time error is performed. 0 after 1 second from the hour 24 hours after
The reset indicates that the display time of the electronic timepiece is delayed by 1 second, and is reset to 0 at the same time when the display time of (5-3) becomes 10: 00.01 (10:00:01). And the display time is set to 10: 00.00 (10
(Hours 00 minutes 00 seconds).

In the above embodiment, the correction is performed every 24 hours. However, since the accuracy of time is improved by shortening the correction interval, it is desirable to set the correction interval as short as possible.

FIG. 6 is a flowchart in the case where the display time is automatically corrected every hour. The relational expression between each input value (s) (h) of the time error setting and the display error (z) every hour is z. = S / h, and the automatic display time correction
Is performed by resetting to 0 at the same time as the display time obtained by subtracting.

When the value of z is negative, the display time is reset to 0 before every hour, and when the value of z is positive, the display time is reset to 0 after every hour to advance. This is to correct the delay.

Except for manual time adjustment such as calculation of a correction interval, a correction amount, and a cumulative time, a history of manually resetting 0 (cumulative time and correction amount) is stored, and the operation of the electronic timepiece is calculated. The display error z per unit time is calculated by the device, and a method of resetting to 0 at the same time as the display time obtained by subtracting the calculation result z from every hour can be programmed and incorporated in the electronic timepiece.

Before shipping an electronic timepiece incorporating the display time correction program of the present invention, it is desirable to set a unique correction value for each timepiece. In this case, in order to grasp the correction value in a short time. Then, the actual oscillation frequency of the oscillator built in the electronic timepiece is measured, the error per unit time is calculated from the frequency division ratio, and the correction value f may be set.

An error per unit time is calculated from an actual oscillation frequency of an oscillator built in the electronic timepiece, and a correction value f
The calculation formula for setting is as follows.

The oscillation frequency of a theoretical oscillator that does not cause accumulated errors is f0 (Hz), the oscillation frequency of an oscillator actually incorporated in an electronic timepiece is f1 (Hz), and the total frequency of the frequency divider of the reference signal generation circuit is Assuming that the circumferential ratio is p, the interval for correction is e (second), and the correction value is f (second), the error in the time per second of the reference second signal is p (f0−f1) (second), When the correction interval is set to e (second), the correction value f (second) = e
-It becomes p (f0-f1).

When the oscillation frequency of the oscillator actually incorporated in the electronic timepiece is a theoretical value, that is, the calculated value of the correction value f when f0 = f1 is 0, no correction is necessary in this case.

[0032]

Since the present invention is configured as described above, it has the following effects.

Even with a popular electronic timepiece, the accuracy of the display time can be improved and the troublesome frequency of correcting the display time can be reduced by the automatic display time correction program.

Further, in the present invention, no additional components are required, and even if the accuracy of the reference oscillator is inferior,
Since the cumulative error can be corrected by the program of the present invention, it is possible to use an oscillator whose conventional electronic timepiece could not guarantee the monthly difference, and to improve the yield of the oscillator, thereby reducing the production cost of the electronic timepiece. be able to.

The display time error due to the change in the oscillation frequency of the oscillator due to the temperature difference between the environment and the area where the electronic timepiece is used is also determined by the display time error data per unit time due to the temperature difference between the environment and the area. Since the automatic correction can be performed, an electronic timepiece with high display time accuracy can be provided regardless of the environment and the area.

[Brief description of the drawings]

FIG. 1 is a diagram in which a program of the present invention is incorporated in a control circuit of a conventional electronic timepiece.

FIG. 2 is a diagram for explaining a shift of a display time with respect to an elapsed time between a conventional electronic timepiece and an electronic timepiece of the present invention.

FIG. 3 is a diagram illustrating an example of inputting an error unique to an electronic timepiece;

FIG. 4 is a diagram showing an embodiment of the present invention in a case where an input electronic clock-specific error is a time delay.

FIG. 5 is a diagram showing an embodiment of the present invention in a case where an input electronic clock-specific error is time advance.

FIG. 6 is a flowchart of an automatic display time correction program according to the present invention.

FIG. 7 is a reference signal generation circuit.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Electronic watch control circuit 2 Electronic watch case 3 Display panel 4 Mode switch 5 Adjust switch a 0 reset b 0 reset c Time error at second 0 reset d Time error per unit time e Correction interval f Correction amount f0 Oscillation frequency of the theoretical oscillator f1 Oscillation frequency of the oscillator actually incorporated in the electronic timepiece h Cumulative time for calculating error time p Total division ratio s Error time t Cumulative time z Display error per hour

Claims (3)

[Claims] 1. An error of a time per fixed time is automatically calculated from an accumulated time from a first time adjustment to a next time adjustment and a time error at that time, and based on the calculation result. A so-called electronic timepiece having a method of automatically calculating a correction value of a time error per fixed time and periodically correcting a display time. 2. A so-called electronic timepiece having a method of periodically correcting a display time based on a time error set value manually set arbitrarily. 3. Accumulated timing errors caused by a difference in reference time due to lack of accuracy of the oscillation frequency of the reference oscillator and a change in the oscillation frequency are calculated based on an error (frequency shift) of the oscillation frequency of the reference oscillator or an actual time error (time difference). A method of performing periodic correction using a correction value (time) obtained from the (error).