JP2009128044A - Electronic timepiece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic timepiece having a display means having a memory property and capable of enabling users to understand the cause of halt of display and verify the absence of failure. <P>SOLUTION: The electronic timepiece 1 is provided with an EPD display device 3; a solar cell 20; a power generation detection circuit 21 for detecting the state of power generation of the solar cell 20; a timer 22 for measuring a non-power-generation duration during which the power generation detection circuit 21 can not detect the state of power generation; and a display control circuit 14 for controlling the EPD display device 3. The display control circuit 14 displays the status as being in the middle of power saving on the EPD display device 3 in the case that the non-power-generation duration measured by the timer 22 has exceeded a preset set period. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electronic timepiece.

  In recent years, a display panel having a memory property (nonvolatile) such as an EPD (Electrophoretic Display) has been developed, and a time display device that displays time on the memory display panel is known (see Patent Document 1). ).

  In the time display device of Patent Document 1, when displaying the time on the memory-type display panel, the time display is retained even when the battery voltage decreases, but the display cannot be updated. In order to solve the problem of grasping an incorrect time, the time display is not displayed when the battery voltage decreases.

Japanese Patent Laid-Open No. 2007-40888

However, if the time display is not displayed when the battery voltage drops, the user may not easily understand why the time is not displayed and may misunderstand that the clock is out of order. There was a problem.
In addition, when digital display means such as a digital quartz clock (DQ) or a combination clock (CQ) is provided, the display panel may be renewed for reasons other than a decrease in battery voltage. When the time display is not displayed, there is a problem that the user cannot know why the time is not displayed and the user cannot appropriately respond.

  An object of the present invention is to provide an electronic timepiece having a memory-type display means that can understand the reason for stopping the display and can confirm that the user is not out of order.

  The electronic timepiece of the present invention is an electronic timepiece having a memory-type display means and a control means for controlling the display means, and the control means corresponds to a condition in which the state of the electronic timepiece is set in advance. In this case, the display mode of the display unit is controlled by switching from the normal display mode to the update stop mode, and the reason for the transition to the update stop mode is displayed on the display unit in the update stop mode. .

In the electronic timepiece of the invention, when the time state of the timepiece, for example, the power generation state, the power supply voltage state, and the temperature state corresponds to a predetermined condition, the control means sets the display mode of the memory-type display means to the normal display mode Switch to update stop mode.
When the control means shifts to the update stop mode, the control means displays the reason for the shift on the display means. Since the display means has a memory property, it is possible to continue displaying the reason for stopping the display without supplying power. For this reason, it is possible to notify the user of the state of the electronic timepiece without consuming power even if the reason for stopping the display is continuously displayed. Therefore, the user can easily understand that the clock is not broken and stopped, and can take an appropriate action to eliminate the reason for stopping the display.
As a result of this appropriate response, when the condition for shifting to the update stop mode is resolved, the control means returns to the normal display mode, and the display means performs normal display such as time display.

  In the present invention, the electronic timepiece includes a power generation unit, a power generation detection unit that detects a power generation state of the power generation unit, and a non-power generation duration measurement unit that measures a non-power generation duration in which the power generation state cannot be detected by the power generation detection unit. And when the non-power generation continuation time measured by the non-power generation continuation time measuring means becomes equal to or longer than a preset set time and shifts to a power save mode, the control means displays the display mode of the display means Is preferably switched from the normal display mode to the update stop mode, and the display means displays that power saving is in progress.

In the present invention, as a condition for switching to the update stop mode, a condition for determining whether or not a power generation state can be detected by the power generation detection means, that is, whether or not a non-power generation continuation time is a set time (for example, 24 hours) or more is set. Yes. When the electronic timepiece satisfies the condition, the control means shifts the electronic timepiece to the power save mode and switches the display mode of the display means to the update stop mode.
At this time, the control means displays on the memory display means that power saving is in progress. Since the display means has a memory property, it is possible to continue displaying that the power is being saved without supplying power. For this reason, even when the power supply voltage is lowered without power generation for a long time, the display means does not consume power and can inform the user of the state of the electronic timepiece. Therefore, the user can easily grasp that the power is currently being saved, and can take appropriate measures such as performing a power generation operation to cancel the state.
When power generation is performed in the power generation device, the control unit determines that the condition for shifting to the update stop mode has been resolved, returns the display mode to the normal display mode, and the display unit displays a normal display such as a time display. Etc.

  In the present invention, the electronic timepiece includes a power supply and power supply voltage detection means for detecting the voltage of the power supply, and the control means has a power supply voltage that is lower than a preset voltage preset by the power supply voltage detection means. When it is detected, it is preferable to control the display mode of the display unit by switching from the normal display mode to the update stop mode, and to display that the display unit is in a power supply voltage drop state.

In the present invention, as a condition for switching to the update stop mode, a condition for determining whether the power supply voltage has dropped below the set voltage is set. When the electronic timepiece satisfies the condition, the control unit switches the display mode of the display unit to the update stop mode, and displays on the display unit that the power supply voltage is in a lowered state. Since the display means has a memory property, it is possible to continue displaying that the power supply voltage is in a lowered state without supplying power. For this reason, even when the voltage of the power source composed of the primary battery or the secondary battery decreases, the display means does not consume power, and the user can be notified of the state of the electronic timepiece. Therefore, the user can easily grasp that the power supply voltage is currently decreasing, and can take appropriate measures such as charging to cancel the state.
When the power supply voltage becomes equal to or higher than the set voltage due to charging or the like, the control means determines that the condition for shifting to the update stop mode has been resolved, and returns the display mode to the normal display mode. Display, such as time display.

  In the present invention, the electronic timepiece includes a power source and temperature detection means for detecting a temperature of the timepiece, and the control means is in a low temperature state lower than a preset temperature preset by the temperature detection means. When detected, it is preferable that the display mode of the display means is controlled by switching from the normal display mode to the update stop mode, and that the low temperature state is displayed on the display means.

In the present invention, as a condition for switching to the update stop mode, a condition is set for determining whether or not the timepiece temperature has dropped below the set temperature. When the electronic timepiece satisfies the condition, the control unit switches the display mode of the display unit to the update stop mode, and displays the low temperature state on the display unit. Since the display means has a memory property, it can continue to display that the temperature is low without supplying power. For this reason, for example, when the timepiece becomes low temperature such as being placed in the outside air below the freezing point, it is possible to notify the user of the state of the electronic timepiece without consuming power in the display means. Therefore, the user can easily grasp that the timepiece is currently at a low temperature, and can take an appropriate action to cancel the state.
When the temperature of the timepiece becomes equal to or higher than the set temperature, the control unit determines that the condition for shifting to the update stop mode has been resolved, returns the display mode to the normal display mode, and displays the normal display, for example, the time on the display unit. Display and so on.

Here, it is preferable that the control means displays the time on the display device when the display mode of the display means is a normal display mode.
For example, the current hour and minute may be digitally displayed on a memory display device such as an electrophoretic display.

  In the present invention, in the normal display mode, the time can be displayed on the memory-type display device, so that power consumption for displaying the time can be reduced. That is, in a memory-type display device, for example, “hour” information may be updated every hour, and “minute” information may be updated every minute. For this reason, the display device can be operated only when each time information (hour and minute) is updated, and the display can be maintained without supplying power until the next update. Therefore, the power consumption can be significantly reduced by using a memory-type display device as compared with the case of using a display device that requires power supply even when maintaining a display, such as a general liquid crystal display.

In the present invention, it is preferable that the control means does not perform a display update operation or a refresh operation of the display device when the display mode of the display means is an update stop mode.
If the display update operation or the refresh operation of the display device is not performed in the update stop mode, power consumption can be reduced compared to the normal display mode. Note that a memory-type display device can maintain display for several days without performing display update or refresh operations. Therefore, the reason for shifting to the update stop mode can be continuously displayed for several days.

In the present invention, it is preferable that when the display mode of the display unit is the update stop mode, the control unit makes the display refresh operation interval of the display device longer than that in the normal display mode.
In the update stop mode, if the display refresh operation interval of the display device is made longer than that in the normal display mode, power consumption can be reduced as compared with the normal display mode. That is, if the refresh operation is performed, for example, at an interval of 1 hour in the normal display mode, and the refresh operation is performed at an interval of 24 hours in the update stop mode, the number of times the display device is driven can be greatly reduced, and the power consumption can be reduced. .

In the present invention, it is preferable that the electronic timepiece includes a pointer that indicates time, and the control unit stops moving the pointer when the display mode of the display unit is an update stop mode.
That is, the electronic timepiece is a combination timepiece having hands, and when the hand movement of the hands is stopped when the display mode of the display means is the update stop mode, the power consumption can be further reduced. For this reason, the display of the reason for shifting to the update stop mode can be continued for a longer time, and the user can be surely notified.

  In the present invention, the electronic timepiece is provided with a pointer for indicating time, and the control means is configured to display the display mode of the display means when the power supply voltage becomes lower than the set voltage or the temperature of the timepiece becomes lower than the set temperature. The needle movement may be continued even when is in the update stop mode.

In general, the voltage value at which the updating operation or the refreshing operation of the memory display means must be stopped is higher than the voltage value at which the stepping motor that moves the pointer must be stopped. Therefore, even when the power supply voltage is lowered and the display unit is set to the update stop mode, the hand movement of the pointer can be continued. In this case, the time indication by the hands can be continued, and the convenience of the watch can be improved.
In addition, when the temperature of the watch decreases, the temperature that affects the operation of the memory-type display means such as the electrophoretic display is higher than the temperature that affects the movement of the pointer by the stepping motor. Therefore, even when the temperature drops and the display means is set to the update stop mode, the hand movement of the pointer can be continued. In this case, the time indication by the hands can be continued, and the convenience of the watch can be improved.

  According to the present invention, in the electronic timepiece having the memory-type display means, the reason for stopping the display can be understood, and the user can confirm that there is no failure.

Embodiments of the present invention will be described below with reference to the drawings.
In addition, regarding the description after the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified.

[First Embodiment]
A first embodiment of the present invention will be described with reference to FIGS.
[1. overall structure]
FIG. 1 is a front view of an electronic timepiece 1 of the present embodiment. The electronic timepiece 1 is a combination timepiece (CQ) including a rectangular annular case 2, an EPD display device (electrophoretic display device) 3, and a pointer 4 including an hour hand 4A, a minute hand 4B, and a second hand 4C.
The case 2 is provided with a crown 5 and buttons 6 and 7. A solar cell 20 is provided on the dial portion of the pointer 4.

[2. System configuration of electronic watch]
As shown in FIG. 2, the electronic timepiece 1 includes an oscillation circuit 11, a frequency dividing circuit 12, a timepiece counter 13, a display control circuit 14, an EPD display device 3, switches 15 and 16 input by buttons 6 and 7, and time correction. A circuit 17, a motor drive control circuit 18, a step motor 19 that drives the pointer 4, a solar battery (power generation device) 20, a power generation detection circuit 21, a timer 22, a stop time counter 23, a charge control circuit 24, and a secondary battery 25 are provided. ing.

The oscillation circuit 11 oscillates a reference oscillation source such as a crystal resonator or a ceramic resonator at a high frequency to generate a reference oscillation signal.
The frequency dividing circuit 12 divides the reference oscillation signal generated by the oscillation circuit 11 to generate a predetermined reference signal (for example, a signal of 1 Hz).

The clock counter 13 counts the reference signal generated by the frequency dividing circuit 12 and measures the current time. The clock counter 13 corrects the counter value, that is, the current time information, based on the time adjustment signal input from the time adjustment circuit 17.
The display control circuit 14 controls the display of the EPD display device 3 based on the current time information measured by the clock counter 13. The configuration of the EPD display device 3 will be described later.

The switches 15 and 16 are input when the buttons 6 and 7 are pressed. That is, the switches 15 and 16 are input detection means for detecting the input of the buttons 6 and 7.
The time adjustment circuit 17 outputs a time adjustment signal to the clock counter 13 and the motor drive control circuit 18 based on input signals from the switches 15 and 16, that is, input operations of the buttons 6 and 7.

  The motor drive control circuit 18 is configured to output a motor drive pulse to the step motor 19 based on the reference signal generated by the frequency divider circuit 12 and to step the pointer 4. When the time adjustment signal from the time adjustment circuit 17 is input, the motor drive control circuit 18 outputs a motor drive pulse to the step motor 19 and corrects the indication of the pointer 4.

The power generation detection circuit 21 detects a power generation state in the solar cell 20 and outputs a power generation detection signal to the timer 22 when the solar cell 20 is in a power generation state. Therefore, the power generation detection circuit 21 constitutes the power generation detection means of the present invention.
The timer 22 measures the elapsed time based on the time signal output from the clock counter 13. Specifically, the timer 22 is configured to receive a signal output from the clock counter 13 every minute, that is, when there is a minute carry, and to count up and measure the elapsed time up to 24 hours. ing.
The timer 22 is reset when a power generation detection signal is output from the power generation detection circuit 21. For this reason, the timer 22 counts the period when power generation is not performed. Accordingly, the timer 22 constitutes the non-power generation measurement time measuring means of the present invention.
The timer 22 outputs a power save transition signal for shifting the electronic timepiece 1 to the power save mode (update stop mode) when the measured time reaches a preset time, which is 24 hours in the present embodiment. When a power generation detection signal is input from the power generation detection circuit 21 and reset, a normal mode return signal for returning to the normal display mode is output.

When the power save transition signal is output from the timer 22, the stop time counter 23 counts the reference signal from the frequency dividing circuit 12 and counts the stop time.
Further, when the power save transition signal is input, the display control circuit 14 displays on the EPD display device 3 that power saving is in progress. Specifically, the display control circuit 14 displays “POWER SAVE” on the EPD display device 3 as shown by the electronic timepiece 1 on the right side of FIG.
Further, when the power save transition signal is input, the motor drive control circuit 18 stops the output of the motor drive signal, and stops the driving of the step motor 19, that is, the movement of the pointer 4.

Further, when the normal mode return signal is input from the timer 22, the stop time counter 23 stops counting the stop time and outputs the counted stop time information to the motor drive control circuit 18.
When the normal mode return signal is input, the motor drive control circuit 18 fast-forwards the step motor 19 based on the stop time information input from the stop time counter 23, and sets the pointer 4 that has stopped moving to the current time. Correct it.
Further, when the normal mode return signal is input, the display control circuit 14 changes the display of the EPD display device 3 from the power save display to the current time display, as shown by the electronic timepiece 1 on the left side of FIG. Change to the current hour and minute display.
Therefore, the control means of the present invention comprises the display control circuit 14, the motor drive control circuit 18, and the stop time counter 23.

The charge control circuit 24 performs control for charging the secondary battery 25 with the electric power generated by the solar battery 20.
Note that the EPD display device 3 is an electrophoretic display device that has been conventionally known, and a description thereof will be omitted. For example, an EPD display device 3 using a two-color powder fluid type electrophoretic layer in which an electrophoretic particle dispersion liquid in which black electrophoretic particles and white electrophoretic particles are dispersed is enclosed in a microcapsule may be employed. That's fine.
The display method of the EPD display device 3 may be a dot matrix method using a TFT circuit or a segment method.

[3. Electronic watch operation control method]
Next, an operation control method of the electronic timepiece 1 will be described based on the flowchart of FIG.
The electronic timepiece 1 first resets and initializes the timer 22 immediately after the start of driving (S10). Next, it is detected by the power generation detection circuit 21 whether the solar cell 20 is generating power (S11). When the solar battery 20 is generating power, the secondary battery 25 is charged via the charge control circuit 24.

When power generation is detected in S 11, the power generation detection circuit 21 outputs a power generation detection signal to the timer 22.
Then, the timer 22 determines whether or not the time measured by the timer 22 is 24 hours (S12).
When the timer 22 has not reached 24 hours, the normal display mode is continuously executed. Specifically, the display control circuit 14 displays the current time on the EPD display device 3 based on the information from the clock counter 13 (S13). When the stop time is counted in the stop time counter 23, that is, immediately after returning from the power save mode to the normal display mode, the motor drive control circuit 18 stops based on the information from the stop time counter 23. The step motor 19 is driven for the amount of time, and the pointer 4 that has stopped moving is moved to a position that indicates the current time (S14). The stop time counter 23 is reset when the process of S14 is performed.

In addition, when power generation is detected in S11, the timer 22 resets the timer in both cases of “Yes” and “No” in S12 (S15).
Next, the clock counter 13 determines whether or not the reference signal (1 Hz) is input from the frequency divider circuit 12, that is, whether there is a second count (S16).
If no power generation is detected in S11, S12 to S15 are not processed, and a second count determination process S16 is performed.
If there is no second count in S16, the process returns to S11 and the process is continued.

On the other hand, if there is a second count in S16, that is, if a reference signal is input, the clock counter 13 counts up (S17).
Next, the timer 22 confirms whether the current count time is 24 hours (S18).
Here, when the timer 22 is 24 hours, the power save mode signal is output, so the stop time counter 23 counts up based on the reference signal from the frequency divider circuit 12 (S19). Therefore, the stop time counter 23 counts the duration time after the power save mode is set.

  If the timer 22 has not reached 24 hours in S18, the motor drive control circuit 18 drives the step motor 19 by one step and moves the pointer 4 (S20) because it is the normal mode. Accordingly, the second hand 4C of the pointer 4 is driven by step operation every second.

Next, the clock counter 13 determines whether or not a minute carry has been performed (S21). That is, when the second counter of the clock counter 13 reaches 60 seconds and the minute counter is counted up, it is determined that the minute carry has been performed.
Here, if the minute carry has not been performed, the process returns to S11 and the above processing is repeated.
On the other hand, when the minute carry is performed in S <b> 21, the clock counter 13 outputs a minute count signal to the timer 22. The timer 22 counts up based on the minute count signal (S22). That is, the timer 22 counts up every minute and counts the elapsed time when power generation is not performed.

  Next, the timer 22 confirms whether it has reached 24 hours (S23). When the timer 22 has reached 24 hours, it outputs a power save transition signal to the display control circuit 14. For this reason, the display control circuit 14 displays on the EPD display device 3 that “power saving is in progress” (S24).

On the other hand, if 24 hours has not been reached in S23, the timer 22 outputs a normal mode return signal to the display control circuit 14, and the display control circuit 14 updates the display of the current time on the EPD display device 3 (S25). That is, the display control circuit 14 displays the current hour and minute on the EPD display device 3 and updates the display.
Thereafter, the electronic timepiece 1 repeats the processing from S11.

Therefore, the electronic timepiece 1 measures the elapsed time after the power generation in the solar cell 20 is stopped by the timer 22, and continues the normal mode until the elapsed time reaches 24 hours. In the normal mode, the current time display update by the hands 4 and the current hour / minute display update in the EPD display device 3 are continued.
Then, when the elapsed time reaches 24 hours, the mode shifts to the power save mode (update stop mode), the operation of the pointer 4 is stopped, and at the same time, “POWER SAVE” is displayed to indicate that the EPD display device 3 is in the power save state. indicate. Here, since the EPD display device 3 has a memory property, the display is maintained even when the voltage application is stopped. Therefore, the display can be maintained while suppressing power consumption, and the hand movement is stopped for the user. The reason can be shown.

According to the above embodiment, the following effects are obtained.
(1) By providing the power generation detection circuit 21 and the timer 22, it can be detected that power generation is not performed for 24 hours. In this case, since the mode is shifted to the power save mode and the movement of the pointer 4 is stopped, the power consumption can be reduced.
And in this embodiment, since it can display on the EPD display device 3 that it has shifted to power save mode at the time of power save mode, the user can grasp | ascertain the reason why hand movement has stopped reliably.
Therefore, when the hand movement is stopped in the power save mode, there is no misunderstanding that the user is out of order, and an operation for canceling the power save mode, for example, power generation by the solar cell 20 is given to the user. The power save mode can be easily canceled.

(2) In addition, since the EPD display device 3 having a memory property is used and the reason for stopping the hand movement is displayed on the EPD display device 3, even if the power supply to the EPD display device 3 is stopped, the reason The display can be continued. Therefore, it is possible to prevent power from being consumed for driving the EPD display device 3 in the power save mode, and it is possible to maintain the power save mode for a long time even when power generation is not performed. For this reason, it can suppress that a power supply voltage falls until the electronic timepiece 1 is system-down, and the drive of the timepiece counter 13 and the stop time counter 23 can be continued also in a power save mode. Therefore, it is possible to automatically return to the current time when power generation in the solar battery 20 is performed, and to provide a highly convenient electronic timepiece 1.

[Second Embodiment]
Next, a timepiece according to a second embodiment of the invention will be described.
As shown in FIG. 4, the electronic timepiece 1B of the second embodiment is the same as the first embodiment in that it is a combination timepiece including the hands 4 and the EPD display device 3.
However, in the first embodiment, the power generation detection circuit 21 and the timer 22 are provided and controlled to shift to the power save mode according to a period during which power generation is not performed.
In contrast, in the second embodiment, as shown in FIG. 5, the power generation detection circuit 21 and the timer 22 are not provided, but the battery voltage detection circuit 31 and the display stop mode control circuit 32 are provided instead. This is different from the first embodiment.
Accordingly, in the following description, the description of the same or similar configuration as that of the first embodiment will be omitted or simplified, and different parts will be mainly described.

  As with the electronic timepiece 1, the electronic timepiece 1 </ b> B according to the second embodiment includes an oscillation circuit 11, a frequency dividing circuit 12, a timepiece counter 13, a display control circuit 14, an EPD display device 3, and switches input by buttons 6 and 7. 15, 16, a time adjustment circuit 17, a motor drive control circuit 18, a step motor 19 for driving the hands 4, a solar battery (power generation device) 20, a stop time counter 23, a charge control circuit 24, and a secondary battery 25. .

Further, unlike the electronic timepiece 1, the electronic timepiece 1 </ b> B includes a battery voltage detection circuit 31 and a display stop mode control circuit 32.
The battery voltage detection circuit 31 detects the voltage of the secondary battery 25, determines whether or not the voltage of the secondary battery 25 exceeds a preset threshold value, and outputs a determination signal. Therefore, the battery voltage detection circuit 31 constitutes the power supply voltage detection means of the present invention.

The display stop mode control circuit 32 displays the display stop mode (update stop mode) for each display control circuit 14, motor drive control circuit 18, and stop time counter 23 based on the determination signal output from the battery voltage detection circuit 31. A display stop mode transition signal for instructing the transition to the normal display mode and a normal display mode return signal for instructing the return to the normal display mode are output.
Therefore, in the second embodiment, the control means includes the display control circuit 14, the motor drive control circuit 18, the stop time counter 23, and the display stop mode control circuit 32.
The battery voltage detection circuit 31 and the display stop mode control circuit 32 are driven each time the reference signal (1 Hz) from the frequency divider circuit 12 is input. Therefore, the battery voltage detection process and the display mode determination and setting process are sampled at intervals of one second.

A control method of the electronic timepiece 1B having such a configuration will be described with reference to the flowchart of FIG.
The electronic timepiece 1B first determines whether or not the reference signal (1 Hz) is input from the frequency divider circuit 12, that is, whether there is a second count (S31). If there is no second count in S31, the process returns to S31 and the process is continued.
On the other hand, if there is a second count in S31, that is, if a reference signal is input, the clock counter 13 counts up (S32).

Next, the electronic timepiece 1B determines whether or not the display stop mode is set (S33).
When it is determined in S33 that the display stop mode is not set (in the case of No), the motor drive control circuit 18 drives the step motor 19 by one step and moves the pointer 4 by one second (S34).

Next, the time counter 13 determines whether or not the second counter of the time counter 13 has reached 60 seconds and a minute carry for counting up the minute counter has been performed (S35). Here, when the minute carry is not performed, the process returns to S31 and the above processing is repeated.
On the other hand, when the minute carry is performed in S35, the clock counter 13 sends a signal to the display control circuit 14, and the display control circuit 14 updates the time display on the EPD display device 3 (S36). That is, since the EPD display device 3 displays only the hour and minute as shown in FIG. 4, the display only needs to be updated every minute. For this reason, the EPD display device 3 is controlled so as to update the display when the minute carry is performed.

Next, the battery voltage detection circuit 31 determines whether the power supply voltage VDD of the secondary battery 25 is less than the threshold value V1 (S37). If the power supply voltage VDD is greater than or equal to the threshold value V1, the process returns to S31 and continues.
On the other hand, if the power supply voltage VDD is less than the threshold value V1, the battery voltage detection circuit 31 outputs a determination signal to the display stop mode control circuit 32. When the display stop mode control circuit 32 receives the determination signal that the power supply voltage VDD is less than the threshold value V1, it outputs a display stop mode transition signal and sets the electronic timepiece 1B to the display stop mode.
The display control circuit 14 that has received the display stop mode transition signal displays “BATT LOW” indicating a decrease in battery voltage on the EPD display device 3 as shown in the electronic timepiece 1B on the right side of FIG. 4 (S39). Then, the process returns to S31.

When S31 and S32 are processed after the display stop mode is set, “Yes” is determined in S33.
Therefore, the driving of the step motor 19 by the motor drive control circuit 18 (S34) is not executed, and the stop time counter 23 is incremented (S40). That is, while the display stop mode is set, the hand 4 is not moved, and the time during which the hand is stopped is measured by the stop time counter 23.

Next, the battery voltage detection circuit 31 determines whether the power supply voltage VDD of the secondary battery 25 is equal to or higher than the threshold value V1 (S41). If the power supply voltage VDD is less than the threshold value V1, the process returns to S31 and continues.
On the other hand, if the power supply voltage VDD is equal to or higher than the threshold value V1, the battery voltage detection circuit 31 outputs a determination signal to the display stop mode control circuit 32. When the display stop mode control circuit 32 receives the determination signal whose power supply voltage VDD is equal to or higher than the threshold value V1, it outputs a normal mode return signal, cancels the setting of the display stop mode, and returns to the normal display mode (S42).

The display control circuit 14 that has received the normal mode return signal displays the current time counted by the time counter 13 on the EPD display device 3 as shown in the electronic timepiece 1B on the left side of FIG. 4 (S43).
Also, the motor drive control circuit 18 that has received the normal mode return signal sends the step motor 19 for the stop time counted by the stop time counter 23 and drives it to indicate the current time of the pointer 4 that has stopped moving. It moves to the position to do (S44).
The stop time counter 23 is reset when the process of S44 is performed.
Thereafter, the electronic timepiece 1B returns to S31 and continues the processing.

Therefore, when the voltage at the secondary battery 25 drops below the threshold value, the electronic timepiece 1B shifts to the display stop mode and stops the hand movement by the pointer 4. At the same time, “BATT LOW” indicating “battery voltage drop” is displayed on the EPD display device 3. Here, since the EPD display device 3 has a memory property, the display is maintained even when the voltage application is stopped. Therefore, the display can be maintained while suppressing power consumption, and the hand movement is stopped for the user. The reason can be shown.
On the other hand, when power is generated by the solar battery 20 in the display stop mode and the voltage of the secondary battery 25 returns to the threshold value or more, the display stop mode is canceled, the current time is displayed on the EPD display device 3, and the pointer 4 is After being fed to the current time, it shifts to normal hand movement.

According to the above embodiment, the following effects are obtained.
(3) By providing the battery voltage detection circuit 31 and the display stop mode control circuit 32, it is possible to detect that the power supply voltage VDD has decreased below the threshold value V1 and shift to the display stop mode. In the display stop mode, since the hand movement of the pointer 4 is stopped, power consumption can be reduced.
In the present embodiment, the display indicating that the battery voltage has decreased on the EPD display device 3 in the display stop mode, and in this embodiment, “BATT LOW” is displayed. That is, it is possible to reliably grasp that the battery voltage has dropped and the hand movement has stopped.
Therefore, when the hand movement is stopped in the display stop mode, there is no misunderstanding that the user is out of order, and an operation for canceling the display stop mode, for example, power generation by the solar cell 20 is performed. Thus, the user can be prompted to increase the power supply voltage, and the display stop mode can be easily released.

(4) In addition, since the EPD display device 3 having a memory property is used and the reason for stopping the hand movement is displayed on the EPD display device 3, even if the power supply to the EPD display device 3 is stopped, the reason The display can be continued. Therefore, it is possible to prevent power from being consumed for driving the EPD display device 3 when the battery voltage is lowered to enter the display stop mode, and the display stop mode can be maintained for a long time even when power generation is not performed. For this reason, it is possible to prevent the power supply voltage from being lowered until the electronic timepiece 1 is brought down, and the driving of the timepiece counter 13 and the stop time counter 23 can be continued even in the display stop mode. Therefore, it is possible to automatically return to the current time when power generation in the solar battery 20 is performed, and to provide a highly convenient electronic timepiece 1.

[Third Embodiment]
Next, an electronic timepiece according to a third embodiment of the invention will be described.
As shown in FIG. 7, the electronic timepiece 1 </ b> C of the third embodiment is the same as the first and second embodiments in that it is a combination timepiece including the hands 4 and the EPD display device 3.
However, the electronic timepiece 1C does not include the solar battery 20, the charge control circuit 24, the secondary battery 25, etc., and uses a primary battery (not shown) as a power source and detects the temperature of the electronic timepiece 1C. The point which performs display control of EPD display device 3 is different from the above-mentioned embodiments.
Accordingly, in the following description, the description of the same or similar configurations as those in the first and second embodiments will be omitted or simplified, and different parts will be mainly described.

  The electronic timepiece 1C of the third embodiment is inputted by the oscillation circuit 11, the frequency dividing circuit 12, the timepiece counter 13, the display control circuit 14, the EPD display device 3, and the buttons 6 and 7, similarly to the electronic timepieces 1 and 1B. Switches 15 and 16, a time correction circuit 17, a motor drive control circuit 18, and a step motor 19 for driving the hands 4.

Further, unlike the electronic timepieces 1 and 1B, the electronic timepiece 1C includes a temperature sensor 41 and a temperature detection circuit 42.
The temperature sensor 41 is a sensor that detects the temperature of the electronic timepiece 1 </ b> C, in particular, the EPD display device 3. Therefore, the temperature sensor 41 constitutes the temperature detection means of the present invention.

The temperature detection circuit 42 determines whether or not the temperature detected by the temperature sensor 41 exceeds a predetermined threshold, and outputs a display stop mode transition signal and a normal mode return signal to the display control circuit 14.
Therefore, in the third embodiment, the control means includes the display control circuit 14, the motor drive control circuit 18, and the temperature detection circuit 42.
The temperature detection circuit 42 is driven every time the reference signal (1 Hz) from the frequency dividing circuit 12 is input. Accordingly, the temperature detection process is sampled at intervals of 1 second.

A control method of the electronic timepiece 1C having such a configuration will be described with reference to the flowchart of FIG.
The electronic timepiece 1C first determines whether or not the reference signal (1 Hz) is input from the frequency divider circuit 12, that is, whether there is a second count (S51). If there is no second count in S51, the process returns to S51 and the process is continued.
On the other hand, when there is a second count in S51, that is, when a reference signal is input, the clock counter 13 counts up (S52).
The reference signal is also input to the motor drive control circuit 18, and the motor drive control circuit 18 drives the step motor 19 by one step to move the pointer 4 by one second (S53).

Next, the electronic timepiece 1C determines whether or not the EPD display device 3 is in the update stop mode (EPD display stop mode) (S54).
If it is determined in S54 that the mode is not the EPD display stop mode (in the case of No), the clock counter 13 determines whether or not a minute carry has been performed (S55). Here, when the minute carry is not performed, the process returns to S51 and the above processing is repeated.

  On the other hand, when the minute carry is performed in S55, the clock counter 13 sends a signal to the display control circuit 14, and the display control circuit 14 updates the time display on the EPD display device 3 (S56). That is, since the EPD display device 3 displays only hours and minutes as shown in FIG. 7, the display only needs to be updated every minute. For this reason, the EPD display device 3 is controlled so as to update the display when the minute carry is performed.

Next, the temperature detection circuit 42 determines whether the temperature t measured by the temperature sensor 41 is less than the threshold value t1 (S57). If the temperature t is less than the threshold value t1, the process returns to S51 and continues.
On the other hand, if the temperature t is equal to or higher than the threshold t1, the temperature detection circuit 42 outputs a display stop mode transition signal to the display control circuit 14, and sets the electronic timepiece 1C to the EPD display stop mode (S58).
The display control circuit 14 that has received the display stop mode transition signal displays “COLD” meaning “low temperature” on the EPD display device 3 as shown in the electronic timepiece 1C on the right side of FIG. 7 (S59). Then, the process returns to S51.

If S51 to S53 are processed after the EPD display stop mode is set, “Yes” is determined in S54.
Therefore, the drive of the step motor 19 by the motor drive control circuit 18 (S53) is executed even in the EPD display stop mode, and the hand movement of the pointer 4 is continued.

Next, the temperature detection circuit 42 determines whether the temperature t measured by the temperature sensor 41 is equal to or higher than the threshold value t1 (S60). If the temperature t is less than the threshold value t1, the process returns to S51 and continues.
On the other hand, if the temperature t is equal to or higher than the threshold t1, the temperature detection circuit 42 outputs a normal mode return signal to the display control circuit 14, cancels the setting of the EPD display stop mode, and returns to the normal display mode (S61).

The display control circuit 14 that has received the normal mode return signal displays the current time counted by the time counter 13 on the EPD display device 3 as shown in the electronic timepiece 1C on the left side of FIG. 7 (S62).
Thereafter, the electronic timepiece 1C returns to S51 and continues the processing.

Accordingly, when the temperature measured by the temperature sensor 41 falls below the threshold value, the electronic timepiece 1C shifts to the EPD display stop mode, continues the hand movement by the pointer 4, and “COLD” indicating “low temperature” to the EPD display device 3. Is displayed. Here, since the EPD display device 3 has a memory property, the display is maintained even when the voltage application is stopped. Therefore, the display can be maintained while suppressing power consumption, and the hand movement is stopped for the user. The reason can be shown.
On the other hand, when the temperature of the electronic timepiece 1C rises and returns to the threshold value or more, the EPD display stop mode is canceled and the current time is displayed on the EPD display device 3.

According to the above embodiment, the following effects are obtained.
(5) By providing the temperature sensor 41 and the temperature detection circuit 42, it is possible to detect that the temperature t has decreased below the threshold value t1, and to shift to the EPD display stop mode. In this EPD display stop mode, the display update of the EPD display device 3 is stopped, so that power consumption can be reduced.
In the present embodiment, in the EPD display stop mode, the EPD display device 3 displays a display indicating that the temperature has decreased. In the present embodiment, “COLD” is displayed, so that the user can update the EPD display device 3. It is possible to reliably grasp the reason that the display has stopped, that is, the display update has stopped due to a decrease in temperature.
Therefore, when updating of the display on the EPD display device 3 is stopped, an operation for canceling the EPD display stop mode, for example, an electronic timepiece 1C, without misunderstanding that the user is out of order, is not necessary. The user can be urged to increase the temperature, and the EPD display stop mode can be easily released.

(6) Further, since the EPD display device 3 having a memory property is used and the reason for stopping the display update is displayed on the EPD display device 3, even if the power supply to the EPD display device 3 is stopped, the reason Can continue to be displayed. Therefore, when the temperature of the electronic timepiece 1C is lowered to enter the EPD display stop mode, it is possible to prevent power from being consumed for driving the EPD display device 3, and the EPD display stop mode can be maintained for a long period of time.

(7) Further, in the present embodiment, when the temperature of the electronic timepiece 1C is lowered, the characteristics of the electrophoretic display element are lowered and the display quality is also deteriorated. Therefore, the display update of the EPD display device 3 is stopped. On the other hand, since the hand movement of the pointer 4 by the step motor 19 is possible even at a low temperature, the finger movement of the pointer 4 is continued. For this reason, even when the user shifts to the EPD display stop mode, the user can grasp the current time and can prevent the convenience from being lowered.

[Modification of the present invention]
Although the embodiment of the present invention has been specifically described above, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be made without departing from the scope of the present invention.

  In each of the embodiments described above, the reason for stopping the display on the EPD display device 3 is displayed in characters, but may be displayed in an icon or a flag instead of characters. That is, it is only necessary to display contents that allow the user to grasp the reason why the display is stopped or the hand movement is stopped.

  In the first embodiment, the display update operation and the refresh operation of the EPD display device 3 are stopped during the power save mode. However, the refresh operation interval of the EPD display device 3 may be controlled to be longer. In this case, there is an advantage that the display quality of the EPD display device 3 can be maintained.

  In the second embodiment, the hand movement of the pointer 4 is also stopped during the display stop mode, but the hand movement may be continued. That is, normally, since the stop voltage of the EPD display device 3 is higher than the stop voltage of the pointer 4, when the battery voltage decreases, the display update of the EPD display device 3 is stopped first, and the battery voltage is further reduced. It may be set so that the hand movement of the pointer 4 is stopped when the pressure drops. There is an advantage that the time can be grasped by the hands 4 if the hands of the hands 4 are continued even in the display stop mode.

  In each of the above embodiments, the combination timepiece is provided with the hands 4 and the EPD display device 3, but the digital timepiece may be provided with only the EPD display device 3 without the hands 4. In the digital timepiece, when the mode is changed to the update stop mode, the time may be displayed without being updated together with the reason for the update stop. However, since the user may misrecognize the time, it is preferable not to display the time but to display only the reason for the update stop.

In each of the above embodiments, the conditions for shifting to the update stop mode have been described in the case where the power generation is not longer than the set time, the power supply voltage is less than the set value, or the temperature is less than the set value, but other conditions are set. May be. For example, in the case of an electronic timepiece used by being worn by a user such as a wristwatch or a pocket watch, an acceleration sensor is provided inside the watch, and the movement of the watch, that is, being worn by the user is detected by the acceleration sensor. In such a case, the normal display mode may be set, and the update stop mode such as the power save mode may be set when the movement of the clock is not detected, that is, when it is detected that the watch is removed from the user.
Furthermore, the plurality of conditions may be determined and set to shift to the update stop mode. For example, information regarding both the duration of the non-power generation state and the power supply voltage may be determined so as to shift to the update stop mode. In this case, a plurality of reasons may be displayed on the EPD display device 3, or one of the reasons may be displayed.

In each of the embodiments described above, the present invention is applied to the dot matrix type EPD display device 3 using a TFT circuit, but the present invention may be applied to a segment type EPD display device 3.
The EPD display device 3 may perform black-and-white two-particle electrophoresis using black particles and white particles, may perform one-particle electrophoresis such as blue and white, or may be a combination other than black and white. Absent.
Further, the memory-type display means is not limited to the EPD display device 3, and may be a display having another memory type. For example, ECD (Electrochromic Display), ferroelectric liquid crystal display, cholesteric liquid crystal display, and the like can be used.
Furthermore, the electronic timepiece of the present invention is not limited to a wristwatch and can be widely applied to devices having a clock function such as a table clock, a wall clock, and a pocket watch.

The best configuration, method and the like for carrying out the present invention have been disclosed in the above description, but the present invention is not limited to this. That is, the invention has been illustrated and described primarily with respect to particular embodiments, but may be configured for the above-described embodiments without departing from the scope and spirit of the invention. Various modifications can be made by those skilled in the art in terms of materials, quantity, and other detailed configurations.
Therefore, the description limited to the shape, material, etc. disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such restrictions is included in this invention.

The schematic diagram which shows the timepiece in 1st Embodiment of this invention. The block diagram which shows the circuit structure of the timepiece of the said embodiment. The flowchart which shows the operation | movement control method of the said embodiment. The schematic diagram which shows the timepiece in 2nd Embodiment of this invention. The block diagram which shows the circuit structure of the timepiece of the said embodiment. The flowchart which shows the operation | movement control method of the said embodiment. The schematic diagram which shows the timepiece in 3rd Embodiment of this invention. The block diagram which shows the circuit structure of the timepiece of the said embodiment. The flowchart which shows the operation | movement control method of the said embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 1B, 1C ... Electronic timepiece, 2 ... Case, 3 ... EPD display device (electrophoretic display device), 4 ... Pointer, 13 ... Clock counter, 14 ... Display control circuit, 17 ... Time adjustment circuit, 18 ... Motor drive Control circuit 19 ... Step motor 20 ... Solar cell 21 ... Power generation detection circuit 22 ... Timer 23 ... Stop time counter 24 ... Charge control circuit 25 ... Secondary battery 31 ... Battery voltage detection circuit 32 ... Display stop mode control circuit, 41... Temperature sensor, 42.

Claims (9)

An electronic timepiece comprising a memory display means and a control means for controlling the display means,
The control means controls the display mode of the display means by switching from the normal display mode to the update stop mode when the state of the electronic timepiece satisfies a preset condition, and at the time of the update stop mode, the control means An electronic timepiece characterized in that the reason for shifting to the update stop mode is displayed on the display means. The electronic timepiece according to claim 1,
A power generation means, a power generation detection means for detecting a power generation state of the power generation means, and a non-power generation duration measurement means for measuring a non-power generation duration time in which the power generation state cannot be detected by the power generation detection means,
The control means normally displays the display mode of the display means when the non-power generation continuation time measured by the non-power generation continuation time measurement means exceeds the preset set time and shifts to the power save mode. An electronic timepiece that is controlled by switching from a mode to an update stop mode, and that the display means displays that power saving is in progress. The electronic timepiece according to claim 1,
A power supply, and a power supply voltage detection means for detecting the voltage of the power supply,
The control means switches the display mode of the display means from the normal display mode to the update stop mode when the power supply voltage detecting means detects that the power supply voltage is lower than a preset voltage. An electronic timepiece that controls and displays on the display means that the power supply voltage is low. The electronic timepiece according to claim 1,
A power source and temperature detecting means for detecting the temperature of the watch;
The control means controls the display mode of the display means by switching from the normal display mode to the update stop mode when the temperature detecting means detects that the temperature is lower than a preset temperature set in advance. And an electronic timepiece displaying a low temperature state on the display means. The electronic timepiece according to any one of claims 1 to 4,
When the display mode of the display means is a normal display mode, the control means displays time on the display device. The electronic timepiece according to any one of claims 1 to 5,
The electronic timepiece according to claim 1, wherein when the display mode of the display means is an update stop mode, the control means does not perform a display update operation or a refresh operation of the display device. The electronic timepiece according to any one of claims 1 to 5,
When the display mode of the display means is the update stop mode, the control means makes the display refresh operation interval of the display device longer than that in the normal display mode. The electronic timepiece according to any one of claims 1 to 7,
It has a guide to indicate the time
The electronic timepiece characterized in that the control means stops the movement of the pointer when the display mode of the display means is an update stop mode. The electronic timepiece according to claim 3 or 4,
It has a guide to indicate the time,
The electronic timepiece characterized in that the control means continues to move the hands even when the display mode of the display means is an update stop mode.

Images