JP2021040448A - Electronic watch - Google Patents

Abstract

To provide an electronic watch capable of preventing a position deviation of an indicator and suppressing power consumption.SOLUTION: An electronic watch 1 includes: a hand 11; a step motor containing a coil C and a rotor 41 and driving the hand 11 in accordance with rotation of the rotor 41; a needle deviation prevention circuit 30 that detects an impact on the basis of a counter electromotive current that is generated in the coil C in response to motion of the rotor 41, and outputs a lock pulse for braking the rotor 41 when the impact is detected; and a control circuit 3 that performs needle position correction processing in accordance with a deviation of the hand 11 from a reference position, and controls the needle deviation prevention circuit 30 on the basis of the occurrence of the needle position correction processing and the detected impact.SELECTED DRAWING: Figure 1

Description

The present invention relates to an electronic clock.

Patent Document 1 discloses an electronic clock having a circuit that detects an impact based on a counter electromotive current generated by an external impact and outputs a lock pulse for braking the rotation of the rotor due to the external impact.

Japanese Unexamined Patent Publication No. 2012-2533

Patent Document 1 employs a configuration in which the size and shape of the output lock pulse are changed according to the magnitude of the impact, but the detected counter electromotive current is affected by the temperature environment and the like. It is difficult to accurately determine the magnitude of the impact. If the magnitude of the impact is erroneously determined, an appropriate lock pulse cannot be output, and the pointer may be misaligned. In addition, if the magnitude of the impact is erroneously determined, a lock pulse that consumes more power than necessary may be output.

An object of the present invention is to provide an electronic timepiece that suppresses power consumption and prevents the position of a pointer from being displaced.

The invention disclosed in the present application in order to solve the above problems has various aspects, and the outline of typical ones of these aspects is as follows.

(1) An impact is detected based on a pointer, a step motor including a coil and a rotor, and driving the pointer with the rotation of the rotor, and a counter electromotive current generated in the coil with the movement of the rotor. When the impact is detected, a needle misalignment prevention circuit that outputs a lock pulse that brakes the rotor and a needle position correction process according to the misalignment of the pointer from the reference position are performed to generate the needle position correction process. An electronic clock having a control circuit for controlling the hand misalignment prevention circuit based on the detected impact.

(2) In (1), the control circuit controls the intensity of the lock pulse, an electronic clock.

(3) In (1) or (2), the impact detection counter that counts the number of occurrences of the impact is further provided, and the control circuit includes the occurrence of the needle position correction process and the count value of the impact detection counter. An electronic clock that controls the intensity of the lock pulse based on.

(4) In (3), when the needle position correction process is generated in the first period and the count value of the impact detection counter is larger than the first threshold value, the control circuit is described. An electronic clock that increases the strength of the lock pulse.

(5) In (4), the first period is an electronic clock during which the pointer makes one revolution.

(6) In any of (3) to (5), in the second period, the needle position correction process has not occurred in the control circuit, and the count value of the impact detection counter is the second. An electronic clock that reduces the intensity of the lock pulse when it is greater than the threshold value of.

(7) In (1) to (6), the control circuit is an electronic clock that controls the impact detection sensitivity.

(8) In (7), the impact detection counter that counts the number of times the impact is generated is further provided, and the control circuit is based on the occurrence of the needle position correction process and the count value of the impact detection counter. An electronic clock that controls the impact detection sensitivity.

(9) In (8), when the needle position correction process is generated in the first period and the count value of the impact detection counter is smaller than the third threshold value, the control circuit is described. An electronic clock that increases the impact detection sensitivity.

(10) In (8) or (9), in the control circuit, the needle position correction process has not occurred in the second period, and the count value of the impact detection counter is from the fourth threshold value. An electronic watch that lowers the impact detection sensitivity if it is also large.

(11) In any one of (7) to (10), the control circuit includes a detection resistor which is a variable resistance used for detecting the counter electromotive force, and the control circuit changes the resistance value of the detection resistor. An electronic clock that controls the impact detection sensitivity.

(12) In any of (7) to (11), the needle misalignment prevention circuit includes an impact detection circuit that outputs an impact signal when the current value of the counter electromotive current is equal to or higher than a predetermined current value. The control circuit is an electronic clock that controls the impact detection sensitivity by changing the predetermined current value.

According to the aspects (1) to (12) of the present invention, it is possible to provide an electronic clock that suppresses power consumption and prevents the position of the pointer from being displaced.

It is a block diagram which shows the outline of the structure of the electronic clock which concerns on 1st Embodiment. It is a figure which shows an example of the waveform of the back electromotive force generated in the coil of a step motor. It is a figure which shows typically the structure for determining the position deviation of the second hand in 1st Embodiment. It is a flowchart which shows the process performed by the control circuit of 1st Embodiment. It is a flowchart which shows each second processing performed by the control circuit of 1st Embodiment. It is a flowchart which shows each minute processing performed by the control circuit of 1st Embodiment. It is a figure which shows the example of the waveform of the lock pulse output in 1st Embodiment. It is a flowchart which shows the process performed by the control circuit of the 1st modification. It is a flowchart which shows each minute processing performed by the control circuit of the 1st modification. It is a flowchart which shows each time processing performed by the control circuit of the 1st modification. It is a flowchart which shows the process performed by the control circuit of the 2nd modification. It is a flowchart which shows each second processing performed by the control circuit of the 2nd modification. It is a flowchart which shows each minute processing performed by the control circuit of the 2nd modification. It is a flowchart which shows the process which the control circuit of the 2nd modification performs when a predetermined time has elapsed from the impact detection. It is a flowchart which shows each minute processing performed by the control circuit of 2nd Embodiment. It is a circuit diagram which shows the outline of the detection circuit in 2nd Embodiment.

Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an outline of the configuration of the electronic clock according to the first embodiment. The electronic clock 1 is an analog clock that displays the time by the pointer 11.

The electronic clock 1 includes an oscillation circuit 2 that outputs a predetermined reference signal by a crystal oscillator (not shown), a control circuit 3 that inputs a reference signal to control each circuit and advance the time, and a drive pulse generation circuit. 4. It has a needle position determination circuit 6, a driver circuit 20, a needle misalignment prevention circuit 30, and a step motor 40.

The step motor 40 includes a coil C and a rotor 41. The rotor 41 is a disk-shaped rotating body magnetized in two poles, and the pointer 11 is driven by the rotation of the rotor 41. The coil C has terminals O1 and O2. The drive waveform output from the driver circuit 20 is input to the terminals O1 and O2.

The drive pulse generation circuit 4 is controlled by the control circuit 3 and outputs a drive pulse for driving the step motor 40 to the pulse selection circuit 33. Although not shown, the electronic clock 1 may further have a correction pulse generation circuit that outputs a correction pulse having a driving force larger than that of the driving pulse.

The needle misalignment prevention circuit 30 includes a detection circuit 31, a lock pulse generation circuit 32, and a pulse selection circuit 33.

The detection circuit 31 detects the movement of the rotor 41 based on the counter electromotive current generated in the coil C of the step motor 40. Further, the detection circuit 31 includes an impact detection circuit 311. The shock detection circuit 311 detects the shock generated in the electronic clock 1 based on the counter electromotive current generated in the coil C of the step motor 40, and when the shock is detected, outputs a shock signal to the control circuit 3. The impact detection circuit 311 includes a comparator, compares the current value of the counter electromotive force with a predetermined threshold value th, and when the maximum value of the current value of the counter electromotive force is equal to or greater than the predetermined threshold value th, the impact is impacted. It is good to output a signal. Further, the electronic clock 1 has an impact detection counter 7 that counts the number of times an impact signal is output by the impact detection circuit 311.

The lock pulse generation circuit 32 outputs a lock pulse for braking the rotor 41 to the pulse selection circuit 33 when an impact is detected by the impact detection circuit 311.

The pulse selection circuit 33 inputs the drive pulse output by the drive pulse generation circuit 4, and selects the waveform of the drive pulse to be output to the driver circuit 20 from among a plurality of types of drive pulses. The selected drive pulse is output to the driver circuit 20. The step motor 40 drives the pointer 11 based on the drive pulse output from the pulse selection circuit 33. The electronic clock 1 may have at least a second hand 11a, a minute hand, and an hour hand for displaying the time as the pointer 11.

Further, the pulse selection circuit 33 inputs the lock pulse generated by the lock pulse generation circuit 32 and selects the lock pulse to be output to the driver circuit 20 from among a plurality of types of lock pulses. The selected lock pulse is output to the driver circuit 20. The rotor 41 is braked based on the lock pulse output from the pulse selection circuit 33.

Since the drive pulse is output every second, the second hand 11a moves with the movement of the rotor 41. If an impact is generated on the electronic clock 1 during the period when the drive pulse is not output, the rotor 41 cannot maintain the stationary state, and the second hand 11a is displaced. The lock pulse is output in order to suppress the positional deviation of the second hand 11a.

FIG. 2 is a diagram showing an example of a waveform of a counter electromotive current generated in a coil of a step motor. The horizontal axis of FIG. 2 shows the time [t], and the vertical axis shows the current value [A] of the counter electromotive force. The waveform shown in FIG. 2 is an example of a counter electromotive force detected by the detection circuit 31 when an impact is generated while the hand movement of the second hand 11a is stopped.

In FIG. 2, the impact waveform W1 shows the counter electromotive force when a relatively large impact is generated, and the impact waveform W2 shows the counter electromotive current when a relatively small impact is generated. Further, the threshold value th shown in FIG. 2 is a current value that serves as a reference for the impact detection circuit 311 to output an impact signal to the control circuit 3. When the detection circuit 31 detects the counter electromotive force of the impact waveform W1 shown in FIG. 2, the impact detection circuit 311 outputs an impact signal to the control circuit 3. On the other hand, when the detection circuit 31 detects the counter electromotive force of the impact waveform W2 shown in FIG. 2, the impact detection circuit 311 does not output an impact signal to the control circuit 3.

Next, the determination of the positional deviation of the second hand 11a will be described with reference to FIG. FIG. 3A is a cross-sectional view schematically showing a structure for determining the position deviation of the second hand in the first embodiment. FIG. 3B is a plan view schematically showing a structure for determining the position deviation of the second hand in the first embodiment.

The hand position determination circuit 6 determines whether or not the pointer indicating the time provided by the electronic clock 1 deviates from the reference position. In the first embodiment, it is determined whether or not the second hand 11a deviates from the reference position indicating 0 seconds every minute, that is, every time the second hand 11a makes one rotation.

The second hand 11a is driven by transmitting the rotation of the rotor 41 via the train wheel. The train wheel may include the gear 61 shown in FIGS. 3 (a) and 3 (b). The gear 61 rotates about the central shaft 61a and has a through hole 61b. The gear 61 makes one rotation as the second hand 11a operates 60 times (for 60 seconds).

Further, the electronic clock 1 may have a light emitting unit 62 and a light receiving unit 63 provided on the opposite side via the through hole 61b. When the second hand 11a is present at the reference position indicating 0 seconds, the hand position determination circuit 6 receives the light L emitted from the light emitting unit 62 through the through hole 61b by the light receiving unit 63, and detects the light to the control circuit 3. Output a signal. On the other hand, when the second hand 11a does not exist at the reference position indicating 0 seconds, the hand position determination circuit 6 does not receive the light L emitted from the light emitting unit 62 (the detected light amount exceeds a predetermined threshold value). (Small), no light detection signal is output.

When the second hand 11a is not misaligned, the light receiving unit 63 is emitted from the light emitting unit 62 once a minute when the second digit of the stepping time in the control circuit 3 is 0 seconds, that is, at the reference position. The light L will be received. On the other hand, when the second hand 11a is misaligned, the light L emitted from the light emitting unit 62 does not pass through the through hole 61b of the gear 61. Therefore, the light receiving unit 63 does not receive the light L emitted from the light emitting unit 62. When the light L is not received at the reference position, the light L is emitted from the light emitting unit 62 every second until the light L is received. The amount of time lag can be determined from the elapsed seconds when the light receiving unit 63 receives the light L that has passed through the through hole 61b. Then, the needle is moved based on the amount of deviation.

When the light detection signal from the hand position determination circuit 6 is not input at the reference position, the control circuit 3 determines that the second hand 11a is displaced. Then, when the control circuit 3 determines that the second hand 11a is displaced, the control circuit 3 performs a hand position correction process. Specifically, the control circuit 3 controls the drive pulse input to the driver circuit 20 so as to correct the positional deviation of the second hand 11a.

Note that FIG. 3 is an example of a method for determining the position deviation of the second hand, and the present invention is not limited to this, and another structure is adopted as long as it can be determined whether or not the second hand 11a is displaced from the reference position. It doesn't matter.

Here, in a timepiece, it is the most important basic function to accurately display the time by the pointer 11, and it is preferable that the pointer 11 does not shift in position. However, when the electronic clock 1 has fallen, or when the user wearing the electronic clock 1 travels on an uneven road, an external impact is generated on the electronic clock 1 and the position of the pointer 11 is displaced. It may end up. Therefore, as described above, a configuration is adopted in which a lock pulse for braking the rotor 41 is output, but if the strength of the lock pulse is insufficient, the pointer 11 will be displaced. Further, when the strength of the lock pulse is larger than necessary, the power consumption becomes unnecessarily large.

Therefore, in the first embodiment, the duty ratio of the output lock pulse is changed based on the occurrence of the needle position correction process and the detected impact, and the lock pulse of the optimum intensity is output. Adopted.

Specifically, an impact is detected during an arbitrary period (first period), for example, while the second hand 11a rotates once, and a lock pulse is output, but a hand position correction process occurs. If so, it was decided to increase the duty ratio of the output lock pulse in order to increase the strength of the lock pulse. This is because the strength of the current lock pulse is not sufficient, the rotor 41 cannot be maintained in a stationary state, and it is considered that the position of the rotor 41 has been displaced due to the impact.

Further, an impact more than a predetermined threshold value (second threshold value) (count value of the impact detection counter) is detected during an arbitrary period (second period), for example, while the second hand 11a rotates once. Despite this, if the needle position correction process did not occur, the duty ratio of the output lock pulse was reduced in order to reduce the strength of the lock pulse. This is because the current lock pulse intensity is considered to be unnecessarily large and the power consumption is considered to be unnecessarily large.

The processing of the control circuit of the first embodiment will be described with reference to FIGS. 4 to 6. FIG. 4 is a flowchart showing a process performed by the control circuit of the first embodiment. FIG. 5 is a flowchart showing each second processing performed by the control circuit of the first embodiment. FIG. 6 is a flowchart showing each minute processing performed by the control circuit of the first embodiment.

The control circuit 3 performs various processes other than the processes such as needle movement, impact detection, and needle position correction of the pointer 11 (other processes shown in FIG. 4, step S1). Other processes include various processes such as radio wave reception process by the receiving circuit and detection process of the amount of power generation in the solar panel, but detailed description thereof will be omitted here.

The control circuit 3 performs each second process shown in FIG. 5 at the timing when the seconds are positive (YES in step S2) (step S3). The positive second is N.I. It is a time indicating 00 seconds (N is an integer of 0 to 59), and is a time to visit every second. That is, the control circuit 3 performs each second processing every second.

Further, the control circuit 3 performs each minute processing shown in FIG. 6 at the timing when M minutes 00 seconds (M is an integer of 0 to 59) (YES in step S4) (step S5). That is, the control circuit 3 performs each minute processing every minute.

Next, each second process in step S3 shown in FIG. 4 will be described with reference to FIG. The control circuit 3 outputs a drive pulse by controlling the drive pulse generation circuit 4 and the pulse selection circuit 33 after prohibiting the impact detection process (step S51) (step S52). As a result, the rotor 41 rotates and the second hand 11a moves for one second.

After that, the control circuit 3 starts the impact detection process (step S53). When the impact signal detected by the impact detection circuit 311 is input (YES in step S54), the control circuit 3 outputs a lock pulse by controlling the lock pulse generation circuit 32 and the pulse selection circuit 33 (step S55). .. Further, the control circuit 3 increases the count value A in the impact detection counter 7 by +1 after the lock pulse is output (step S56).

Next, with reference to FIG. 6, each minute processing in step S5 shown in FIG. 4 will be described. The control circuit 3 starts a hand position determination process for determining whether or not the second hand 11a is deviated from the reference position (step S61). When the control circuit 3 does not input the light detection signal from the hand position determination circuit 6, that is, when it is determined that the second hand 11a is deviated from the reference position (YES in step S62), the drive pulse generation circuit 4 and By controlling the pulse selection circuit 33, the needle position correction process is performed (step S63). Further, the control circuit 3 sets a hand position correction flag _{F B} indicating that the hand position correction process is generated _(F B = 1) _(step S64).

The control circuit 3 may, in any of the first period, have generated hand position correction flag _{F B (F B = 1)} (YES in step S65), and the count value A of the shock detection counter 7 is 0 ( When it is larger than the first threshold value (YES in step S66), the duty ratio of the lock pulse output when the next impact occurs is increased by controlling the lock pulse generation circuit 32 and the pulse selection circuit 33 (YES in step S66). DUTY_UP!) (Step S67). That is, it is determined that the strength of the current lock pulse is not sufficient, and the strength of the lock pulse is increased. The first threshold value may be an integer larger than 0.

The control circuit 3, at any given second period, no standing hand position correction flag _{F B (F B = 0)} (NO in step S65), and the count value A of the shock detection counter 7 is predetermined When (A> Ath1) is larger than the threshold value Ath1 (second threshold value) of (YES in step S68), the lock pulse generation circuit 32 and the pulse selection circuit 33 are controlled to be output when an impact occurs next time. The duty ratio of the lock pulse is reduced (DUTY_DOWN!) (Step S69). That is, it is determined that the strength of the current lock pulse is larger than necessary, and the strength of the lock pulse is lowered.

Further, the control circuit 3, a hand position correction flag _{F B} is not standing _(F B = 0) _(NO in step S65), and the count value A of the shock detection counter 7 predetermined threshold Ath1 (second If it is less than or equal to (threshold value) (A> not Ath1) (NO in step S68), it is determined that the current lock pulse intensity is appropriate, and the process proceeds to S610. Further, the control circuit 3 is standing hand position correction flag FB _(F B = 1) (YES in step S65), and the count value A of the shock detection counter 7 0 (first threshold value) or less (A If it is (not> 0) (NO in step S66), it is determined that the current lock pulse intensity is appropriate, and the process proceeds to S610.

Also, the end of each minute treatment, hand position correction flag _{F B,} and clears the count value A of the shock detection counter _{7 (F B = 0, A} = 0) (step S610). Thus, for each minute treatment, hand position correction flag F _B, and by clearing the count value A of the shock detection counter 7, appropriate locking pulse in the last one minute (while the second hand 1a rotates one round) It is possible to determine whether or not the strength is high.

FIG. 7 is a diagram showing an example of the waveform of the lock pulse output in the first embodiment. 7 (a) to 7 (e) show lock pulses having the same output period and different duty ratios.

FIG. 7A shows a lock pulse having a duty ratio of 8/32. FIG. 7B shows a lock pulse with a duty ratio of 24/32. FIG. 7 (c) shows a lock pulse having a duty ratio of 28/32. Further, FIG. 7D shows a lock pulse in which the first half is a full pulse (duty ratio is 32/32) and the second half is a duty ratio of 28/32. FIG. 7 (e) shows a full pulse lock pulse.

In the electronic clock 1 according to the first embodiment, as shown in FIG. 7, a plurality of types of lock pulses having different waveforms can be output to the driver circuit 20. Which waveform of the lock pulse is to be output may be selected by the pulse selection circuit 33.

The larger the duty ratio, the stronger the lock pulse and the higher the power consumption. That is, the intensity of the lock pulse of the waveform shown in FIG. 7 (e) is the largest, and the power consumption is the largest. The intensity of the lock pulse of the waveform shown in FIG. 7A is the smallest, and the power consumption is the smallest.

For example, in the control circuit 3, when the current lock pulse has the waveform shown in FIG. 7 (b) and the duty ratio is increased in step S67 of FIG. 6, the lock pulse to be output next time is determined in FIG. 7 (c). It is recommended to switch to the waveform shown in. Further, for example, in the control circuit 3, when the current lock pulse has the waveform shown in FIG. 7 (b) and the duty ratio is lowered in step S69 of FIG. 6, the lock pulse to be output next time is shown in FIG. 7 (b). It is advisable to switch to the waveform shown in a).

The waveform of the lock pulse shown in FIG. 7 is an example, and is not limited to this. Further, although five waveform patterns are shown in FIG. 7, the present invention is not limited to this, and the number of waveform patterns may be larger than this.

Next, a first modification of the first embodiment will be described with reference to FIGS. 8 to 10. FIG. 8 is a flowchart showing a process performed by the control circuit of the first modification. FIG. 9 is a flowchart showing each minute processing performed by the control circuit of the first modification. FIG. 10 is a flowchart showing each time processing performed by the control circuit of the first modification. Since each second processing in the first modification is the same as that shown in FIG. 5, description and illustration thereof are omitted here. Further, the same processing as that shown in FIGS. 4 and 6 will be appropriately described by using the same reference numerals.

The electronic clock 1 of the first modification may have a duty ratio down counter (not shown) in addition to the configuration shown in FIG.

The control circuit 3 performs each minute processing shown in FIG. 9 at the timing when M minutes 00 seconds (M is an integer of 0 to 59) (YES in step S4) (step S85). That is, the control circuit 3 performs each minute processing every minute.

Further, the control circuit 3 performs each time process shown in FIG. 10 at the timing when P: 00: 00 (P is an integer of 0 to 23) (step S86) (step S87). That is, the control circuit 3 performs each hour processing every hour.

Next, with reference to FIG. 9, each minute processing in step S85 shown in FIG. 8 will be described. The control circuit 3 starts a hand position determination process for determining whether or not the second hand 11a deviates from the reference position (step S61). The control circuit 3 drives when the light detection signal from the hand position determination circuit 6 is not input, that is, when it is determined that the second hand 11a is deviated from the reference position (there is a hand deviation) (YES in step S62). By controlling the pulse generation circuit 4 and the pulse selection circuit 33, the needle position correction process is performed (step S63). Further, the control circuit 3 sets a hand position correction flag _{F B} indicating that the hand position correction process is generated _(F B = 1) _(step S64).

The control circuit 3 is standing hand position correction flag _{F B (F B = 1)} (YES in step S65), and the count value A of the shock detection counter 7 is larger than 0 (A> 0) if ( YES in step S66), by controlling the lock pulse generation circuit 32 and the pulse selection circuit 33, the duty ratio of the lock pulse output when an impact occurs next time is increased (DUTY_UP!) (Step S67). That is, it is determined that the strength of the current lock pulse is not sufficient, and the strength of the lock pulse is increased.

The control circuit 3 is not standing hand position correction flag _{F B} (NO in step _{S65) (F B = 0)} , and the count value A of the shock detection counter 7 is greater than a predetermined threshold Ath2 (A> In the case of Ath2) (YES in step S98), the count value n of the duty ratio down counter is increased (n = n + 1) (step S99). On the other hand, the control circuit 3, a hand position correction flag _{F B} is not standing (FB = 0) (NO in step S65), and the count value A of the shock detection counter 7 predetermined threshold Ath2 following (A> Ath2 In the case of (NO in step S98), the count value n of the duty ratio down counter is not increased. Further, the control circuit 3, when the hand position correction flag _{F B} is raised (FB = 1) (YES in step S65) is not up-count value n of the duty ratio down counter.

Also, the end of each minute treatment, hand position correction flag _{F B,} and clears the count value A of the shock detection counter _{7 (F B = 0, A} = 0) (step S610).

Further, each time process in step S87 shown in FIG. 8 will be described with reference to FIG.

When the count value n of the duty ratio down counter is larger than the predetermined threshold value nth (n> nth) (YES in step S101), the control circuit 3 controls the lock pulse generation circuit 32 and the pulse selection circuit 33. , The duty ratio of the lock pulse output when an impact occurs next time is reduced (DUTY_DOWN!) (Step S102). On the other hand, when the count value n of the duty ratio down counter is equal to or less than a predetermined threshold value nth (n> nth) (NO in step S101), the control circuit 3 maintains the current duty ratio of the lock pulse.

Further, at the end of each time processing, the count value n of the duty ratio down counter is cleared (n = 0) (step S103).

In the first modification, when the duty ratio of the lock pulse seems to be larger than necessary, the result is not immediately reduced in each minute processing, but 60 times in each minute processing in the most recent hour. Therefore, we decided to bring it down. This reduces the possibility that the rotor 41 cannot be kept stationary by lowering the duty ratio of the lock pulse in a state where the duty ratio of the lock pulse should not be lowered due to false detection of impact or the like. can do. As a result, it is possible to reduce the possibility that the second hand 11a will be displaced.

Next, a second modification of the first embodiment will be described with reference to FIGS. 11 to 14. FIG. 11 is a flowchart showing a process performed by the control circuit of the second modification. FIG. 12 is a flowchart showing each second processing performed by the control circuit of the second modification. FIG. 13 is a flowchart showing each minute processing performed by the control circuit of the second modification. FIG. 14 is a flowchart showing a process performed by the control circuit of the second modification when a predetermined time has elapsed from the impact detection. Note that the same processing as that shown in FIGS. 4 to 6 will be appropriately described by using the same reference numerals.

In addition to the configuration shown in FIG. 1, the electronic clock 1 of the second modification may have a time counter for measuring the elapsed time after detecting an impact (not shown).

The control circuit 3 performs each second process shown in FIG. 12 at the timing when the seconds are positive (positive seconds (00 msec)) (YES in step S2) (step S113). That is, the control circuit 3 performs each second processing every second.

Further, the control circuit 3 performs each minute processing shown in FIG. 13 at the timing (YES in step S4) when the time reaches M minutes 00 seconds (M is an integer of 0 to 59) (step S115). That is, the control circuit 3 performs each minute processing every minute.

Further, the control circuit 3 performs the process shown in FIG. 14 at the timing when the count value T of the time counter becomes equal to or higher than a predetermined threshold value Tth (T ≧ Tth) (step S116) (step S117). The time counter counts the time every second, and the threshold value Tth may be, for example, 30 minutes 00 seconds, 2 hours 00 minutes 00 seconds, or the like.

Next, with reference to FIG. 12, each second process in step S113 shown in FIG. 11 will be described.

When the impact signal detected by the impact detection circuit 311 is input (with impact detection) (YES in step S54), the control circuit 3 outputs a lock pulse by controlling the lock pulse generation circuit 32 and the pulse selection circuit 33. (Step S55). Further, the control circuit 3 raises the counter in the impact detection counter 7 (A = A + 1) after the lock pulse is output (step S56).

Further, when the count value T of the time counter is 0 (not T> 0) (NO in step S127), the control circuit 3 starts the time count by the time counter (step S128). Further, the control circuit 3 ends this process when there is no input of the impact signal detected by the impact detection circuit 311 (no impact detection) (NO in step S54).

Next, with reference to FIG. 13, each minute processing in step S115 shown in FIG. 11 will be described.

The control circuit 3 is standing hand position correction flag _{F B (F B = 1)} (YES in step S135), and the count value A of the shock detection counter 7 is larger than 0 (A> 0) if ( By controlling the lock pulse generation circuit 32 and the pulse selection circuit 33 in YES) of step S136, the duty ratio of the lock pulse output when the next impact occurs is increased (DUTY_UP!) (Step S137). That is, it is determined that the strength of the current lock pulse is not sufficient, and the strength of the lock pulse is increased. Further, the control circuit 3 is not set hand position correction flag _{F B (F} is not a B = 1) case (NO in step S135), and proceeds to step S138, the hand position correction flag _{F B,} and impact clears the count value a of the detection counter _{7 (F B = 0, a} = 0) is. Further, the control circuit 3, a hand position correction flag _{F B} are standing _(F B = 1) _(YES in step S135), and, when the count value A of the shock detection counter 7 is 0 (NO in step S136 ), The process proceeds to step S138.

At the end of each minute treatment, hand position correction flag F _B, and clears the count value A of the shock detection counter 7 (step S138).

Next, the process shown in FIG. 14 will be described. The process shown in FIG. 14 is the process of step S117 of FIG. 11 performed when a predetermined time (threshold value Tth) has elapsed (T ≧ Tth) from the occurrence of the impact (YES in S116 of FIG. 11).

The control circuit 3 is larger count value A of the shock detection counter 7 than a predetermined threshold value Ath3, and, if the hand position correction flag _{F B} is not set (A> Ath3 and _F B = 0) (YES in step S141 ), The duty ratio of the lock pulse output when an impact occurs next time is reduced (DUTY_DOWN!) (Step S142). That is, the intensity of the lock pulse is lowered. Thereafter, the count value T of the elapsed time counter, the hand position correction flag _{F B,} and clears the count value A of the shock detection counter _{7 (T = 0, F B} = 0, A = 0) (step S143).

In the second modification, after a predetermined time has elapsed since the latest impact was generated, more impacts than the predetermined threshold value Ath3 were detected during one rotation of the second hand 11a. Regardless, if the needle position correction process did not occur, the duty ratio of the output lock pulse was reduced. This is because the current lock pulse strength is larger than necessary and power consumption is not required because the hands are not displaced even though the user wearing the electronic watch 1 is in an environment where shocks are likely to occur. This is because it is considered to be in a large state.

In the first embodiment and its modification, an example of changing the duty ratio of the lock pulse has been described, but the present invention is not limited to this, and the holding force with respect to the rotor 41, that is, the strength of the lock pulse is changed. Anything that does. For example, instead of increasing the duty ratio of the lock pulse, it is preferable to increase the holding force with respect to the rotor 41 by lengthening the output period of the lock pulse or increasing the absolute value of the voltage of each chopper of the lock pulse.

Next, the second embodiment will be described with reference to FIGS. 15 and 16. FIG. 15 is a flowchart showing each minute processing performed by the control circuit of the second embodiment. Since the processing other than each minute processing in the second embodiment is the same as that shown in FIGS. 4 and 5 of the first embodiment, description and illustration thereof are omitted here. Further, the same processing as that shown in FIG. 6 of the first embodiment will be appropriately described by using the same reference numerals.

The control circuit 3, a hand position correction flag _{F B} are standing (FB = 1) (YES in step S65), and also the count value A of the shock detection counter 7 is above a predetermined threshold Ath4 (third threshold) If it is small (YES in step S156), the sensitivity of impact detection is increased (S157). That is, the condition for outputting the impact signal by the impact detection circuit 311 is relaxed. This is because if the needle position correction process is performed in the last minute and the occurrence of impact is relatively small, the condition for outputting the lock pulse may be severe.

Control circuit 3 in the second period of an arbitrary period of time, (not the F B ₌ 1) hand position correction flag F _B is not standing (NO in step S65), and the count value of the impact detecting counter 7 When A is larger than a predetermined threshold value Ath5 (fourth threshold value) (A> Ath5) (YES in step S158), the sensitivity of impact detection is lowered (sensitivity_DOWN!) (Step S159). That is, the condition for outputting the impact signal by the impact detection circuit 311 is strict. This is because if the needle position correction process has not been performed in the last minute and the impact is relatively large, the condition for outputting the lock pulse may be loose. Further, the control circuit 3, a hand position correction flag _{F B} are standing _(F B = 1) _(YES in step S65), and the threshold count value A is predetermined impact detection counter 7 Ath4 (third threshold If) greater than (not a <Ath4) (nO in step S156), the hand position correction flag _{F B} in step S610, the and clears the count value a of the shock detection counter _{7 (F B = 0, a} = 0) Move to the process of Further, the control circuit 3, a hand position correction flag _{F B} is not set _{(not F} B = 1) (NO in step S65), and the threshold count value A is predetermined impact detection counter 7 Ath5 (No. 4 threshold) or less (a> not Ath5 case) (nO in step S158), the hand position correction of the step S610 the flag _{F B,} and clears the count value a of the shock detection counter _{7 (F B = 0, a} = 0) Move to the process to be performed.

In the second embodiment, by appropriately setting the conditions for outputting the lock pulse, it is possible to suppress the power consumption and prevent the position deviation of the pointer.

FIG. 16 is a circuit diagram showing an outline of the detection circuit according to the second embodiment. In the second embodiment, a configuration is adopted in which the detection sensitivity is changed by adopting a configuration in which the resistance value of the detection resistor in the detection circuit 31 is variable. In the second embodiment, the detection circuit 31 includes transistors TR1 and TR2 for switching ON and OFF of impact detection. Further, the detection circuit 31 includes a detection resistor including resistors R1 to R3 and transistors TR3 to TR6 for switching the resistance value of the detection resistor when detecting the counter electromotive force generated by the impact.

The detection circuit 31 acquires the waveform of the counter electromotive force corresponding to the resistance value of the detection resistor. By increasing the resistance value of the detection resistor, the counter electromotive voltage generated by the acquired counter electromotive force increases, so that the detection sensitivity increases. That is, the lock pulse is easily output. On the other hand, by reducing the resistance value of the detection resistor, the counter electromotive voltage generated by the acquired counter electromotive force is reduced, so that the detection sensitivity is lowered. That is, the lock pulse is less likely to be output.

The circuit diagram shown in FIG. 16 is an example, and the number and arrangement of resistors are not limited to this, and any circuit configuration may be used as long as the resistance value of the detection resistor can be changed.

The detection sensitivity is not limited to the one changed by changing the resistance value of the detection resistor, and may be changed by changing the threshold value th shown in FIG. Increasing the threshold th decreases the detection sensitivity. That is, the lock pulse is easily output. When the threshold value th is lowered, the detection sensitivity is increased. That is, the lock pulse is less likely to be output.

In the first embodiment and its modification, a counter for counting the number of times the needle position correction process has occurred is further provided, and the control circuit 3 supplies the count value of the counter and the count value of the impact detection counter 7. The needle misalignment prevention circuit may be controlled or the detection sensitivity may be controlled based on the above.
Further, the second embodiment may be used together in the first embodiment and its modifications.

Further, the impact detection circuit 311 may change the output impact signal depending on the magnitude of the generated impact (current value of the counter electromotive force). In this case, the impact detection counter 7 increases the count value based on the impact signal output when a large impact occurs and the impact signal output when a small impact occurs. It may include a counter. Then, the control circuit 3 may control the needle misalignment prevention circuit 30 based on each count value.

Although the embodiment according to the present invention has been described above, the specific configuration shown in this embodiment is shown as an example, and it is not intended to limit the technical scope of the present invention to this. Those skilled in the art may appropriately modify these disclosed embodiments, and it should be understood that the technical scope of the invention disclosed herein also includes such modifications.

1 Electronic clock, 2 Oscillator circuit, 3 Control circuit, 4 Drive pulse generation circuit, 6-needle position determination circuit, 61 gear, 61a central axis, 61b through hole, 62 light emitting part, 63 light receiving part, 7 impact detection counter, 11 pointer , 11a second hand, 20 driver circuit, 30 hand misalignment prevention circuit, 31 detection circuit, 311 impact detection circuit, 32 lock pulse generation circuit, 33 pulse selection circuit, 40 step motor, 41 rotor, C coil.

Claims (12)

Guidelines and
A step motor that includes a coil and a rotor and drives the pointer as the rotor rotates.
A needle misalignment prevention circuit that detects an impact based on the counter electromotive current generated in the coil with the movement of the rotor and outputs a lock pulse that brakes the rotor when the impact is detected.
A control circuit that performs needle position correction processing according to the deviation of the pointer from the reference position and controls the needle deviation prevention circuit based on the occurrence of the needle position correction processing and the detected impact.
Have,
Electronic clock. The control circuit controls the intensity of the lock pulse.
The electronic clock according to claim 1. It also has an impact detection counter that counts the number of times the impact has occurred.
The control circuit controls the strength of the lock pulse based on the occurrence of the needle position correction process and the count value of the impact detection counter.
The electronic clock according to claim 1 or 2. The control circuit increases the strength of the lock pulse when the needle position correction process is generated in the first period and the count value of the impact detection counter is larger than the first threshold value.
The electronic clock according to claim 3. The first period is during one rotation of the pointer.
The electronic clock according to claim 4. The control circuit lowers the strength of the lock pulse when the needle position correction process has not occurred and the count value of the impact detection counter is larger than the second threshold value in the second period.
The electronic clock according to any one of claims 3 to 5. The control circuit controls the impact detection sensitivity.
The electronic clock according to claims 1 to 6. It also has an impact detection counter that counts the number of times the impact has occurred.
The control circuit controls the impact detection sensitivity based on the occurrence of the needle position correction process and the count value of the impact detection counter.
The electronic clock according to claim 7. When the needle position correction process is generated in the first period and the count value of the impact detection counter is smaller than the third threshold value, the control circuit increases the impact detection sensitivity.
The electronic clock according to claim 8. In the second period, when the needle position correction process has not occurred and the count value of the impact detection counter is larger than the fourth threshold value, the control circuit lowers the impact detection sensitivity.
The electronic clock according to claim 8 or 9. Includes a detection resistor, which is a variable resistor used to detect the counter electromotive force.
The control circuit controls the impact detection sensitivity by changing the resistance value of the detection resistor.
The electronic clock according to any one of claims 7 to 10. The needle misalignment prevention circuit includes an impact detection circuit that outputs an impact signal when the current value of the counter electromotive current is equal to or higher than a predetermined current value.
The control circuit controls the impact detection sensitivity by changing the predetermined current value.
The electronic clock according to any one of claims 7 to 11.

Images