JPH09264972A - Electronic timepiece and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic timepiece, which returns to the present time quickly with less electric power when the hand moving is stopped when the charging voltage of a storage device becomes low and the time indication is recovered when the charging voltage becomes high in the electronic timepiece having a generating device such as a solar battery. SOLUTION: In addition to the control for the quick movement of an hour hand 21 or a minute hand 22 to present time, the control for the reverse movement is provided. The electric power consumed when the quick movement is performed and the electric power when the reverse movement is performed are operated. A motor 28 or 29 is driven into the direction, where dissipation power is less. Thus, the reduction of the electric power required for the time indication is achieved, the time required for returning can be shortened and the time indication thereafter can be performed stably.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic timepiece equipped with a power generator such as a solar cell.

[0002]

2. Description of the Related Art A power generation device such as a solar cell and a power storage device charged by the power generation device are provided, and when power is not supplied from the power generation device, the power storage device continuously operates by the power discharged from the power storage device. Electronic watches have been developed. However, if the electronic timepiece provided with the solar cell is left for a long time without being exposed to sunlight, the power storage device is also discharged, and the electronic timepiece stops counting time.
Therefore, the correct time is not displayed even if the time measurement is started by being exposed to sunlight thereafter. In particular, in an electronic timepiece that uses a motor to move hands or drives a display plate to display time, the electric power consumed by the motor is relatively large. Therefore, in order to display the correct time for a long time, a large power storage device having a large capacity is required.
However, in a small and lightweight electronic timepiece suitable for carrying, the capacity of a power storage device that can be mounted is limited. Furthermore, in recent years, electronic timepieces that have multiple functions such as communication functions in addition to the timekeeping function have been developed. As the number of functions installed increases, the power consumption also increases, and the time that can be displayed more and more. Will be limited.

[0003]

In order to extend the time that can be timed using a power storage device having a limited capacity, the motor, which consumes a large amount of power, is stopped when the charging voltage of the power storage device falls below a predetermined value. An electronic timepiece has been developed that can stop time display and keeps time for a long time by utilizing only the timekeeping function. In such an electronic timepiece, when the power generation device resumes power generation and a sufficient voltage is established in the power storage device, the movement of the hands while the display is stopped is changed to high speed by rotating the motor at high speed. It is played back with, and the current time is displayed again.

In such an electronic timepiece, when the electric power charged in the power storage device decreases, the time display by the motor that consumes a large amount of power is stopped so that the timekeeping function that consumes a small amount of power continues to operate for a long time. Can be made. However, it is necessary to reproduce the movement of the needle at high speed while the display is stopped after the voltage is established. Therefore, a very large amount of power is consumed during this period. Reproduction of the time display is performed immediately after the predetermined voltage is established in the power storage device, so it cannot be said that the state of charge of the power storage device is always sufficient, and restoration of the time display reduces the charging voltage. There may be a situation where the hand movement must be stopped again. Furthermore, if a long time has elapsed from when the time display was stopped to when it was restarted, the time required to play the hand movements at high speed and display the current time becomes longer, and the user can set the correct time during this time. I can't confirm.

Therefore, it is an object of the present invention to provide an electronic timepiece capable of returning to the current time in a short time and further reducing the power consumed thereby, and a control method thereof. Then, it is an object of the present invention to provide an electronic timepiece that can reproduce the current time in a short time when the voltage is restored, and can continue to display the time stably thereafter, and a control method thereof.

[0006]

Therefore, according to the present invention, not only the time display motor can be fast-forwarded but also reverse-driven, and the power consumptions required for fast-forwarding and reverse-feeding are compared. However, the motor is rotated in the direction in which the consumed power is small, and the current time is restored. That is, the electronic timepiece of the invention includes a power generation device, a power storage device charged by the power generation device, and at least one motor that displays time with electric power supplied from the power storage device. It has a time display control means for stopping the time display when it decreases and restarting the time display when the charging voltage becomes high, and a time measuring device for measuring the time by at least one of the power from the power storage device and the power of the battery power supply. Further, a first control means for fast-forward controlling the motor in the forward direction and a second control means for controlling the reverse feeding of the motor in the reverse direction are provided, and the display time immediately before the time display control means restarts the time display. Means for supplying power, first power consumption for fast-forwarding from the display time to the current time of the time measuring device, and second power consumption for reverse-feeding from the display time to the current time. A calculating means for calculating the power consumption,
The first control means is selected when the first power consumption is equal to or less than the second power consumption, and the second control means is selected when the first power consumption is larger than the second power consumption. By means of the selecting means, the motor is rotated in the direction in which the power consumption is the smallest, and the current time is quickly restored.

As the display time immediately before restarting the time display, the time when the time display control means stops the display may be stored in the memory and the time display may be adopted. In addition, considering the case where the crown is operated and the display time changes while the time display is stopped, the state of the time display such as the hand position immediately before restarting the time display is detected using a magnetic sensor or the like. Is desirable.

Since the motor that drives the hands and the display plate to display the time mainly rotates in the forward direction, the power consumption when rotating in the forward direction is smaller than the power consumption when rotating in the reverse direction. Often gets smaller. Therefore, the rotation direction is selected by comparing the magnitude of power consumption, rather than simply comparing the rotation angle required to display the current time. If the power consumption is the same for fast-forward and reverse-forward,
I try to select more reliable fast-forward.

Further, the time display control means is provided with a first motor for displaying a time unit and a second motor for displaying a minute unit, and the calculating means provides first and second time units and minute units, respectively. By calculating the power consumption of each and rotating in the direction in which each power consumption decreases
The current time can be restored in a shorter time, and the power consumption can be further reduced.

In such an electronic timepiece, the time display is returned to the present time by the following steps.

1. The time display control means identifies the display time immediately before restarting the time display.

2. The first power consumption for fast-forwarding from the displayed time to the current time of the timer is obtained.

3. Simultaneously with or before or after this, the second power consumption for reverse feeding from the display time to the current time is obtained.

4. The first and second power consumptions are compared.

5. When the first power consumption is equal to or less than the second power consumption, the first control means is selected.

6. When the first power consumption is larger than the second power consumption, the second control means is selected.

When the time display control means is provided with the first motor for displaying the time unit and the second motor for displaying the minute unit, each of the second to sixth steps is performed. It can be done for the motor.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of an electronic timepiece according to the present invention. The electronic timepiece 10 of the present example includes a solar cell 1 as a power generation device, the power storage device 2 is charged by the electric power generated by the solar cell 1, and the time display function and the timekeeping function are activated. There is. The electronic timepiece 10 of this example includes a display unit 20 having an hour hand 21 indicating time and a minute hand 22 indicating minute, a first motor 28 for moving the hour hand 21, and a second motor 29 for moving the minute hand 22. ing. The first motor 28 can be rotated in the forward direction and the reverse direction by the drive pulse supplied from the first motor drive circuit 26, and similarly, the second motor 2 can be rotated.
9 is rotatable in the forward direction and the reverse direction by the drive pulse supplied from the second motor drive circuit 27. The first and second motor drive circuits 27 are connected in parallel to the solar cell 1 and the power storage device 2, and while the solar cell 1 is generating electric power, the motor 28 is driven by the electric power supplied from the solar cell 1. When 29 and 29 are driven and power is not supplied from the solar cell, the motors 28 and 29 are driven by the electric power discharged from the power storage device 2.

The electronic timepiece 10 of this example is provided with a time display control section 3 for controlling these motor drive circuits 26 and 27, and the time display control section 3 converts the time display data supplied from the timekeeping section 7. Based on this, the motor drive circuits 26 and 27 are controlled to display the time. Further, the electronic timepiece 10 of this example supplies the motor drive circuit 26 with a fast-forward control section 4 that supplies a fast-forward pulse for rotating the motor in the forward direction at high speed.
And a reverse feed control section 5 for supplying a reverse feed pulse for rotating the motor in the reverse direction at a high speed. The fast-forwarding control unit 4 and the reverse-feeding control unit 5 are also driven by respective motor drive circuits 26 and 27 according to an instruction from the time display control unit 3.
Drive pulse is supplied to. Further, the time display control unit 3 of the present example monitors the charging voltage of the power storage device 2, and when the charging voltage falls below a predetermined voltage, the motor drive circuits 26 and 27 are stopped and the time display is stopped. Is equipped with. Furthermore, if the charging voltage increases above a certain voltage,
It also has a function of restarting the motor drive circuits 26 and 27 and restarting the time display. In the electronic timepiece 10 of this example, the motor drive circuits 26 and 27 correspond to the circuits with the largest power consumption. Therefore, by stopping the electric power supplied to these motor drive circuits 26 and 27, the discharge rate of power storage device 2 can be reduced and the timekeeping function of timekeeping unit 7 can be utilized for a longer period of time.

The electronic timepiece 10 of this example further includes a display unit 2.
The display time detection unit 6 for detecting the positions of the hour hand 21 and the minute hand 22 at 0 by a magnetic sensor or the like is provided. Therefore, the electronic timepiece 10 of the present example can accurately grasp the current positions of the hour hand 21 and the minute hand 22 on the display unit 20 even when the user moves each hand using the crown 23. . The display time of the display unit 20 detected by the display time detection unit 6 is input to the time display control unit 3, and the motors 28 and 29 are fast forwarded or reversely fed based on this display time.

The timekeeping section 7 of the electronic timepiece 10 according to the present embodiment includes an oscillating section 9 for oscillating a reference frequency such as a crystal oscillator, and a secondary power source 8 having a relatively small capacity as compared with the power storage device 2 such as a backup capacitor or a backup. The solar cell 1 is equipped with a battery, and while the solar cell 1 is generating electric power, the electric power supplied from the solar cell 1 is used to measure the time. When the solar cell 1 stops generating electric power, the electric power discharged from the power storage device 2 is used to measure the time. To do. Furthermore, the timekeeping unit 7 of the present example measures the time by the power of the power storage device 2 even after the charging voltage of the power storage device 2 drops below a predetermined voltage and the time display control unit 3 stops the motor drive circuits 26 and 27. The function can be maintained. And
When the power storage device 2 is further discharged and the operating voltage of the timekeeping unit 7 cannot be maintained, the voltage of the secondary power supply 8 can continue the timekeeping. Therefore, in the electronic timepiece 10 of this example, the timekeeping function continues to operate even if the time display is stopped, and the accurate time should be displayed whenever the voltage is restored and the time can be displayed. You can Note that the power supply to the motor drive circuits 26 and 27 is stopped while sufficient power remains in the power storage device 2, so that the timekeeping function can continue to function for a sufficiently long time. Not necessarily required. Further, the timer unit 7 may of course be operated by a battery power source different from the power storage device. Further, the electronic timepiece 10 of the present example includes a diode 30 that prevents a backflow of charges from the power storage device 2 to the solar cell 1, and a diode 31 that prevents a backflow of charges from the timer 7 to the power storage device 2. .

The operation of returning the time display of the electronic timepiece 10 of this embodiment will be described with reference to the flow chart shown in FIG. Once the charging voltage drops below a predetermined value and the time display is stopped, in step 31, the solar cell 1 resumes power generation and waits for the charging voltage of the power storage device 2 to be established. When the charging voltage is established, in step 32, the time display control unit 3 uses the display time detection unit 6 to set the angle (θ11) of the hour hand 21 and the angle (θ) of the minute hand 22 of the display unit 20.
12) to get. Of course, the following processing can be performed using the position data that changes into an angle. Then, in step 33, it is determined whether or not the display of the hour hand is reset, and first, the resetting of the time display is started. In step 34, the motor 28 for driving the hour hand is selected. Next, in step 36, the time display control unit 3 consumes electric power when the motor 28 is fast-forwarded from the angle θ11 of the display time to the angle (θ01) of the hour hand 21 of the current time supplied from the timekeeping unit 7. Is calculated. For example,
When the display time immediately before restarting the time display is 2:15 and the current time is 12:00, the electric power consumed by the motor drive circuit 26 when the hour hand 21 is rotated in the forward direction is When the power consumption per angle is x, it is expressed by the following formula. In this example, the actual calculation is performed in time units.

ABS ((θ01−θ11) × x) = (12−2) × x = 10x (1) In the next step 37, the motor drive circuit is operated when the hour hand 21 is rotated in the reverse direction. The power consumed at 26 is calculated. In general, when the display motor is rotated in the reverse direction, the power consumption is higher than when it is rotated in the forward direction, and here it is assumed that the power consumption per unit angle is 5x. Therefore, the power consumption when rotating in the reverse direction is calculated by the following formula.

ABS ((θ11 + (360−θ01) × 5x) = (2 + 12−12) × 5x = 10x (2) In this example, the motor drive circuit is used in the case of fast-forwarding and the case of reverse-feeding. The result is that the power consumption is the same in step 26. The calculation results are compared in step 38, and the power consumption in the case of fast-forwarding is the same as the power consumption in the case of reverse-forwarding, so fast-forwarding is selected and the fast-forwarding control unit 4 determines in step 39. As a result, the hour hand 21 is fast-forwarded to the 12 o'clock position in step 41. The motors 28 and 29 for moving the hands and the train wheel connecting these motors with the hour or minute hands are normally rotated in the forward direction. Therefore, the electronic timepiece 10 of the present embodiment is more reliable when the calculated power consumption is equal in the forward direction and the backward direction. And so as to return the time display to select the direction.

When the hour hand 21 returns to the present time, it is judged in step 42 whether or not the setting of the minute hand 22 has been completed. If not set, the process returns to step 33, and then the motor 29 for the minute hand is selected in step 35. To do. Then, the same calculation as above is repeated. The minute hand 22 obtains the display angle (θ02) of the current time of the minute hand, and the power consumption when fast-forwarding and backward-feeding is steps 36 and 37.
Is calculated as follows.

Fast-forward: (12 −3) × x = 9x Reverse-feed: (3 + 12−12) × 5x = 15x (3) Therefore, fast-forward is selected in step 38, and similar to the above, the fast-forward controller. A drive pulse is supplied from 4 to the second motor drive circuit 27. Then, when the minute hand 22 returns to the current time, the motor drive circuit 27 is operated by the time display signal of the timekeeping unit 7 in step 41, and the correct time is continuously displayed.

On the other hand, the hour hand 21 or the minute hand 22
Is at the 1 o'clock position and returns to the 12 o'clock position,
In steps 36 and 37, the power consumption is calculated as follows.

Fast-forward: (12-1) × x = 11x Reverse-feed: (1 + 12-12) × 5x = 5x (4) Therefore, reverse-feed is selected in step 38 and reverse-feed control is performed in step 40. The drive pulse is supplied from the section 5 to the corresponding motor drive circuit, and the hour hand 21 or the minute hand 22 is reversed to return to the current time.

When the time display of the display unit 20 is returned to the current time in this way, the time display control unit 3 proceeds to step 4
The charging voltage is further monitored at 3. Then, when the charging voltage decreases, the time display is stopped in step 44, the electric power of the power storage device 2 is held, only the time counting function is continuously operated, and the process returns to step 31 to wait for the voltage to be restored.

As described above, in the electronic timepiece of this example, the display time immediately before starting the hand movement, the current time when the voltage is restored and the hand movement is restarted, and the motor is rotated in the forward direction. Time and the power consumption when the motor is rotated in the opposite direction are used to achieve the most power saving time adjustment, preventing the power recharged in the power storage device from being wasted. However, the subsequent time display is made stable and reliable. Therefore, the electronic timepiece of the present example can keep accurate time even if the time display is stopped but the timekeeping function continues to operate even when the solar cell stops generating power and runs short of power. . And
Once the time display function is restored, an accurate display time can be obtained, and further stable and reliable hand movement can be expected thereafter.

Further, in the electronic timepiece of this example, a motor is provided for each of the hour hand and the minute hand so that the current time can be restored separately. For this reason, each of the hour and minute hands can return to the current time with the lowest power,
The power consumed by both the hour and minute hands can be minimized. Furthermore, since the hour hand and the minute hand can be separately controlled to be restored, the time from the time display function is restored until the accurate current time is displayed can be greatly shortened.

In this example, the display time is obtained from the hand position immediately before the return, but the time when the time display is stopped is stored, and it is of course possible to use the time to return the hour hand and the minute hand. . Further, even in an electronic timepiece in which the hour hand and the minute hand are driven by a single motor, it is possible to prevent the waste of power consumption by checking the power consumed in the forward direction and the reverse direction as described above and returning to the current time. Also,
The time display is not limited to the type in which the hands are rotated as in this example, and it goes without saying that it may be an electronic timepiece that rotates the side of the display plate.

Further, in the electronic timepiece of this example, a solar cell is used as a power generator, but the present invention can be applied to an electronic timepiece equipped with various power generators such as a device for generating power by moving a weight. Of course.

[0034]

As described above, according to the present invention, when returning from the display time immediately before the start of hand movement to the current time, the power consumption when the motor is rotated in the forward direction and the reverse direction. By calculating the power consumption when the motor is rotated, the time can be adjusted to achieve the most power saving. Therefore, the power consumed to restore the time display can be reduced. Furthermore, since the time display is moved in the opposite direction so that the current time can be restored, the time required to return to the current time can be greatly reduced. Further, by providing a motor for each of the hourly display and the minutely display, these displays can be restored to the current time separately, so that the time and power consumption required for the restoration can be further reduced.

Therefore, according to the present invention, it is possible to prevent the electric power recharged in the power storage device from being wasted. Therefore, even if the electric power generation of the solar cell or the like is stopped and the electric power is insufficient, the time is counted. It is possible to provide an electronic timepiece in which the function can be continuously operated to measure an accurate time, and further, once the time display function is restored, the accurate display time can be stably performed for a long time.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an electronic timepiece according to the invention.

FIG. 2 is a flowchart showing a process of returning the time display in the electronic timepiece shown in FIG.

[Explanation of symbols]

 1 ・ ・ Solar cell 2 ・ ・ Power storage device 3 ・ ・ Time display control unit 4 ・ ・ Fast forward control unit 5 ・ ・ Reverse feed control unit 6 ・ ・ Display time detection unit 7 ・ ・ Timekeeping unit 10 ・ ・ Electronic clock 20 ・ ・Display unit 21..Hour hand 22..Minute hand 23..Ryuzu 26,27..Motor drive circuit 28,29..Motor 30,31..Backflow prevention diode

Claims (4)

[Claims] 1. A power generation device, a power storage device charged by the power generation device, and at least one motor that displays time with electric power supplied from the power storage device, the time being measured when the charging voltage of the power storage device decreases. A time display control unit that stops the display and restarts the time display when the charging voltage becomes high, a time measuring device that measures time by at least one of the electric power from the power storage device or the electric power of the battery power supply, and the motor in the forward direction. A first control means for fast-forwarding control, a second control means for reverse-feeding the motor in a reverse direction, a means for supplying a display time immediately before the time display control means restarts time display, The first power consumption for fast-forwarding from the display time to the current time of the timekeeping device and the reverse feed from the display time to the current time. Calculating means for determining a second power consumption, and whether the first power consumption is equal to the second power consumption,
Or a selection means for selecting the first control means when the power consumption is less than the second power consumption and a selection means for selecting the second control means when the first power consumption is higher than the second power consumption. Electronic clock. 2. The time display control means according to claim 1, wherein the time display control means includes a first motor that displays a time unit and a second motor that displays a minute unit. An electronic timepiece, wherein the first and second power consumptions are obtained for each minute unit. 3. A power generation device, a power storage device charged by the power generation device, and at least one motor that displays time with electric power supplied from the power storage device, the time being measured when the charging voltage of the power storage device decreases. A time display control unit that stops the display and restarts the time display when the charging voltage becomes high, a time measuring device that measures time by at least one of the electric power from the power storage device or the electric power of the battery power supply, and the motor in the forward direction. A method for controlling an electronic timepiece having a first control means for fast-forward control and a second control means for reverse-feeding the motor in a reverse direction, immediately before the time display control means restarts time display. And a second step of determining a first power consumption for fast-forwarding from the display time to the current time of the timing device. A third step of obtaining a second power consumption for the reverse feed from the display time to the current time, a fourth step of comparing the first and second power consumptions, and The power consumption of 1 is equal to the second power consumption,
Alternatively, when the number is small, the fifth control means selects the first control means.
And a sixth step of selecting the second control means when the first power consumption is larger than the second power consumption. 4. The time display control means according to claim 3, further comprising a first motor that displays a time unit and a second motor that displays a minute unit, and A method of controlling an electronic timepiece, wherein step 6 is performed for each of the first motor and the second motor.