JP5540926B2 - Analog electronic clock - Google Patents

Description

  The present invention relates to an analog electronic timepiece that displays time by rotating a pointer using a step motor.

  In general, an analog electronic timepiece that displays a time by rotating a plurality of hands using a step motor is known. In such an analog electronic timepiece, the step motor is driven by applying a drive pulse having a predetermined pulse width to the step motor. Then, the movement of the step motor is transmitted to the pointer, and the pointer rotates.

  In an analog electronic timepiece, when strong acceleration is applied, accurate rotation of the hands may be hindered. Conventionally, when an acceleration sensor is mounted on an analog electronic watch and acceleration is detected above a predetermined value, the hand stops and only the time is measured, and when the acceleration decreases, the pointer is fast-forwarded to correct the display time. After that, a technique for resuming the movement is disclosed (for example, Patent Document 1).

JP 2002-62380 A

  However, if the hand movement is stopped, there is a problem that the time cannot be obtained while acceleration is applied to the analog electronic timepiece.

  An object of the present invention is to provide an analog electronic timepiece capable of stably moving a hand even when acceleration is applied.

In order to achieve the above object, the present invention provides:
In an analog electronic timepiece that moves the hands with a step motor and displays the time,
An acceleration detecting means for detecting acceleration of two axes orthogonal to each other in the plane of rotation of the pointer;
Acceleration direction calculating means for obtaining the direction of acceleration based on the output of the acceleration detecting means;
The effective value of the drive pulse supplied to the step motor is changed according to the magnitude of the acceleration detected by the acceleration detecting means and the direction of the acceleration calculated by the acceleration direction calculating means and the position of the pointer. Drive pulse control means for causing
It is characterized by having.

  According to the present invention, in an analog electronic timepiece, it is possible to measure the biaxial acceleration in the rotation plane of the hands. And since the effective value of the drive pulse supplied to the step motor that rotates the pointer according to the direction of the measured acceleration can be changed, the pointer can be driven stably even in a situation where acceleration is applied. effective.

It is a block diagram which shows the internal structure of the analog electronic timepiece of 1st Embodiment of this invention. It is a figure explaining the relationship between the direction of acceleration and the movement of a pointer. It is a flowchart which shows the control procedure which drives the second hand of the analog electronic timepiece of 1st Embodiment. It is a flowchart which shows the control procedure which drives the hand of the analog electronic timepiece of 2nd Embodiment. It is a block diagram which shows the internal structure of the analog electronic timepiece of 3rd Embodiment. It is a flowchart which shows the control procedure which drives the second hand of the analog electronic timepiece of 3rd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a block diagram showing the internal structure of the analog electronic timepiece according to the first embodiment of the present invention.

  This analog electronic timepiece 1 includes an hour hand 2, a minute hand 3, a step motor 23 that rotates the hour hand 2 and the minute hand 3 in conjunction with each other via a train wheel mechanism 32, 33, a second hand 4, and a second hand 4. And a control unit 80 (acceleration direction calculation means, drive pulse control means) that incorporates a step motor 24 that rotates via a central processing unit 34 and performs overall control of the analog electronic timepiece 1 by incorporating a CPU (central processing unit) and the like. A RAM (Random Access Memory) 81 that provides a working memory space to the CPU of the control unit 80 and a ROM (Read Only Memory) that stores various programs executed by the CPU of the control unit 80, initial setting data, and the like 82, an oscillation circuit 88 that generates and outputs an oscillation signal having a constant frequency, and a frequency signal that is used as a reference for hand movement such as time display by dividing the oscillation signal input from the oscillation circuit 88. A frequency dividing circuit 89, a switch unit 90 that converts a user operation into a signal and outputs the signal to the control unit 80, a biaxial acceleration sensor 91 as an acceleration detection unit that measures acceleration, and measurement data of the acceleration sensor. An A / D conversion circuit 92 that converts to a digital signal, and drive circuits 83 and 84 that output a drive pulse to the step motors 23 and 24 based on a control signal from the control unit 80 to perform step driving are provided.

  The control unit 80 is set based on a time counting process for counting time, time data obtained by the time measuring process, acceleration data input from the A / D conversion circuit 92, an input signal from the switch unit 90, and the like. A process of outputting a drive pulse having a pulse width or voltage value from the drive circuits 83 and 84 to the step motors 23 and 24 is performed.

  The drive circuits 83 and 84 output drive pulses for step driving the step motor 23 for rotating the hour hand 2 and the minute hand 3 and the step motor 24 for rotating the second hand 4, respectively. The drive pulse output from the drive circuit 84 to the step motor 24 can change the length of the signal and the voltage value, that is, the amount of current flowing through the step motors 23 and 24, based on a command from the control unit 80. It is configured.

  For example, the hour hand 2, the minute hand 3, and the second hand 4 (hereinafter also referred to as hands 2 to 4) rotate around the same axis passing near the center of the analog electronic timepiece 1, for example. The second hand 4 is configured to rotate 6 degrees per second via the train wheel mechanism 34 and make one round in 60 steps for 60 seconds. The minute hand 3 is configured to rotate once every 10 seconds via the train wheel mechanism 33 and make one round in 360 steps per hour. The hour hand 2 rotates every 10 seconds via a train wheel mechanism 32 that operates in conjunction with the train wheel mechanism 33, and makes one turn in 12 hours.

  The biaxial acceleration sensor 91 is a sensor capable of measuring the acceleration in the biaxial directions orthogonal to each other in the plane in which the hands 2 to 4 rotate. The two axes are not particularly limited. For example, the 3 o'clock direction from the rotation center of the hands 2 to 4 is set as the X axis, and the 12 o'clock direction from the rotation center of the hands 2 to 4 is set as the Y axis. The The acceleration data measured by the biaxial acceleration sensor 91 is converted into a digital signal by the A / D conversion circuit 92 and sent to the control unit 80.

  Next, the principle of setting the drive pulse width output from the drive circuit 84 will be described.

  FIG. 2 is a diagram for explaining the relationship between the acceleration and the movement of the pointer.

  FIG. 2A is a diagram illustrating an output result of the biaxial acceleration sensor 91. FIG. 2B shows the dial and the hands 2 to 4 of the analog electronic timepiece 1. In the example shown in FIG. 2A, as indicated by the point f, the output of the biaxial acceleration sensor 91 indicates a certain value in the minus side (9 o'clock) direction of the X axis. That is, the analog electronic timepiece 1 has an inertial force (including centrifugal force) in the 3 o'clock direction in the direction opposite to the acceleration. At this time, in the region (3 o'clock to 9 o'clock) indicated by diagonal lines in FIG. I need it. On the other hand, in the area (9 o'clock to 3 o'clock) where the display by hatching is not made in FIG. 2B, the minute hand 3 is moved in the direction in which the inertial force acts. Therefore, the minute hand 3 can be sufficiently moved by the driving force at rest.

  Therefore, in the analog electronic timepiece 1 of the present embodiment, when acceleration occurs in the analog electronic timepiece 1, a torque of a level or more that may hinder the rotation of the hands 2 to 4 is generated by the inertial force acting on the hands 2 to 4. The presence / absence of acceleration and the relationship between the pointer position and the acceleration direction are detected. Then, if necessary, for example, by increasing the pulse width of the drive pulse, the effective value of the drive pulse supplied by the drive circuits 83 and 84 is increased from that at rest, and the pointers 2 to 4 are stopped. It has a structure to prevent.

  Next, an operation procedure for driving the hands of the analog electronic timepiece 1 will be described.

  FIG. 3 is a flowchart showing the procedure of the control process of the pointer driving operation executed by the CPU of the control unit 80.

  This control process is an interrupt process started by the CPU of the control unit 80 based on a 1 Hz signal input from the frequency divider 89 to the control unit 80.

  When this interrupt process is called and started at the drive timing of the second hand 4, the CPU first performs a process of detecting acceleration in the X-axis and Y-axis directions (step S101). In this detection processing, the CPU acquires acceleration data input to the control unit 80 after being measured by the biaxial acceleration sensor 91 and converted to a digital signal by the A / D conversion circuit 92.

  Next, the CPU calculates the direction and magnitude of acceleration in the rotation plane of the hands 2 to 4 based on the acquired acceleration data (step S102). Then, the CPU determines whether or not the calculated acceleration magnitude is larger than a predetermined reference value (step S103). This predetermined reference value is an acceleration value within a range in which the hands 2 to 4 can operate without any fear of stopping by the inertial force.

  If it is determined that the magnitude of the acceleration is equal to or less than the predetermined reference value, the processing of the CPU proceeds to step S106. On the other hand, if it is determined that the magnitude of the acceleration is larger than a predetermined reference value, the process proceeds to step S104.

  In the determination processing in step S104, the CPU determines whether or not the position of the second hand 4 is within a range of −180 degrees (30 seconds ago) to 0 degrees with respect to the direction of acceleration measured in the rotation plane. To do. When it is determined that the position of the second hand 4 is within the range of 0 seconds from 30 seconds before the measured acceleration direction, the CPU steps the drive pulse having a pulse width larger than normal from the drive circuit 84. The motor 24 is supplied (step S105). On the other hand, if it is determined that the position of the second hand 4 is not within the range of the direction of 0 seconds from 30 seconds before the measured acceleration direction, the processing of the CPU proceeds to step S106.

  When the processing of the CPU proceeds to step S106, the CPU sends a command to the drive circuit 84 to supply a normal drive pulse having a small pulse width to the step motor 24.

  If the drive pulse is supplied to the drive circuit 84 in the processes of steps S105 and S106, the CPU ends the interrupt process.

  As described above, according to the analog electronic timepiece 1 of the present embodiment, the biaxial acceleration sensor 91 that measures the acceleration in the rotation plane of the hands 2 to 4 is provided, and an acceleration larger than a predetermined reference value is detected. In this case, while the second hand 4 moves in the acceleration direction, a drive pulse having a pulse width larger than usual is supplied from the drive circuit 84 to the step motor 24, so that the analog electronic timepiece 1 is stable even when acceleration is applied. The second hand 4 can be driven.

  Also, by changing the drive pulse width according to the magnitude of acceleration and the positional relationship with the pointers 2 to 4, the pulse width can be increased more than necessary in a stationary state or in a state where the acceleration direction and the direction of movement of the pointer are opposite. It is not necessary to generate a large drive pulse, and therefore power consumption can be kept low.

  In addition, by appropriately controlling the drive pulse width based on the measurement data of the biaxial acceleration sensor 91, rotation of the hands 2 to 4 when acceleration is generated without improvement of other operation parts or change of configuration. The certainty can be improved.

  In particular, by setting the change of the drive pulse width as described above for the second hand 4 that is most susceptible to the acceleration due to the longest hand among the hands 2 to 4 and the high rotation frequency, it is efficient. Accurate time can be displayed continuously.

[Second Embodiment]
FIG. 4 is a flowchart illustrating a procedure of a control process of the pointer driving operation executed by the CPU of the control unit 80 in the analog electronic timepiece 1 of the second embodiment.

  The analog electronic timepiece 1 of the second embodiment has the same configuration as that of the analog electronic timepiece 1 of the first embodiment, and therefore the description of the configuration is omitted.

  In the pointer driving operation of the second embodiment, a pulse width control process corresponding to the acceleration is performed for the minute hand 3 and the hour hand 2 as well. In the flowchart of FIG. 4, the control processing of the drive pulse for driving the second hand 4 shown in steps S101 to S106 is the same as the processing of steps S101 to S106 in the flowchart in the first embodiment of FIG. To do.

  When the process of supplying the drive pulse with the set pulse width from the drive circuit 84 to the step motor 24 is completed (steps S105 and S106), the CPU of the control unit 80 subsequently determines whether or not the timing is every 10 seconds. It discriminate | determines (step S110). Specifically, for example, the CPU determines whether or not the value of the first digit of the second of the current time is “0”. If it is determined that the timing is not every 10 seconds, the CPU ends the interrupt processing as it is.

  On the other hand, if it is determined that the timing is every 10 seconds, the CPU then determines in advance the magnitude of acceleration in the rotation plane of the hands 2 to 4 measured by the biaxial acceleration sensor 91. It is determined whether or not it is larger than the reference value (step S113). If it is determined that the magnitude of the acceleration is not greater than a predetermined reference value, the processing of the CPU proceeds to step S116. This reference value may be the same as the reference value used in the determination processing in step S103, or may be a different value in accordance with the length and mass of the hands 2 and 3.

  If it is determined that the magnitude of the acceleration is greater than a predetermined reference value, the CPU then continues from 30 seconds before the direction of acceleration in which the positions of the hour hand 2 and the minute hand 3 are measured to the direction of acceleration. It is determined whether or not it is between (step S114). If it is determined that the position of either the hour hand 2 or the minute hand 3 is not between 30 seconds before the measured acceleration direction and the acceleration direction, the processing of the CPU proceeds to step S116. Then, the CPU supplies a drive pulse having a small pulse width to the step motor 23 from the drive circuit 83, and ends the interrupt process. On the other hand, if it is determined that the positions of the hour hand 2 and the minute hand 3 are both between 30 seconds before the measured acceleration direction and the acceleration direction, the CPU drives a driving pulse having a large pulse width. The circuit 83 is supplied to the step motor 23 (step S115). Then, the interrupt process ends.

  As described above, according to the analog electronic timepiece 1 of the second embodiment, the width of the drive pulse output from the drive circuit 83 can be changed based on the magnitude and direction of the acceleration measured by the biaxial acceleration sensor 91. By doing so, not only the second hand 4 but also the minute hand 3 and the hour hand 2 can be stably rotated.

  In this embodiment, the pulse width of the drive pulse is set large only when both the hour hand 2 and the minute hand 3 move in the direction of acceleration. However, at least one of the hands 2 and 3 moves in the direction of acceleration. In this case, the pulse width can be set large.

[Third Embodiment]
FIG. 5 is a block diagram showing an internal configuration of the analog electronic timepiece 1a according to the third embodiment. FIG. 6 is a flowchart showing the procedure of the control process of the pointer driving operation executed by the CPU of the control unit 80 in the analog electronic timepiece 1a of the third embodiment.

  In addition to the configuration of the analog electronic timepiece 1 of the first embodiment, the analog electronic timepiece 1a of the third embodiment includes a uniaxial acceleration sensor 93 that detects acceleration in a direction perpendicular to the rotation plane of the hands 2 to 4, and A / D conversion circuit 94 is provided. Other configurations are the same as those of the first embodiment, and the same reference numerals are given and description thereof is omitted.

  Further, in the analog electronic timepiece 1a of the third embodiment, setting of the pulse width of the pulse signal supplied by the drive circuit 84 based on the measurement data of the uniaxial acceleration sensor 93 in addition to the measurement data of the biaxial acceleration sensor 91. I do. The processes in steps S102a to S104a, S105, and S106 in FIG. 6 are the same as the processes in steps S102 to S104, S105, and S106 shown in FIG.

  The uniaxial acceleration sensor 93 is a sensor that measures the acceleration in the direction perpendicular to the rotation plane of the hands 2 to 4, and the A / D conversion circuit 94 uses the measurement data of the uniaxial acceleration sensor 93 as a predetermined sampling rate. Are converted into digital signals and output to the control unit 80. In the present embodiment, for example, the Z axis is set in the direction from the back side to the front side of the analog electronic timepiece 1a, and acceleration data in the Z axis direction is acquired from the A / D conversion circuit 94. The two-axis acceleration sensor 91 and the one-axis acceleration sensor 93 may be provided in the analog electronic timepiece 1a as a single three-axis acceleration sensor.

  In the control process in the analog electronic timepiece 1a of the third embodiment, the CPU of the control unit 80 first measures the measurement data of the 2-axis acceleration sensor 91 and the 1-axis acceleration sensor 93 digitized from the A / D conversion circuits 92, 94. Is acquired (step S120). Then, the CPU determines whether or not the acquired acceleration in the Z-axis direction is larger than a predetermined reference value (step S121).

  If it is determined in the determination process in step S121 that the magnitude of the acceleration in the Z-axis direction is larger than a predetermined vertical reference value, the CPU causes the drive circuit 84 to execute regardless of the magnitude or direction of the acceleration in the XY plane. A drive pulse having a large pulse width is output (step S105). On the other hand, if it is determined that the magnitude of the Z-axis direction acceleration is not larger than the vertical reference value, the CPU proceeds to step S102a, and then the CPU performs the XY in-plane acceleration direction, And the size is calculated.

  As described above, according to the analog electronic timepiece 1a of the third embodiment, the 2-axis acceleration sensor 91 and the 1-axis acceleration sensor 93 are provided, and the acceleration in the 3-axis direction can be measured. The width of the driving pulse of the second hand 4 is controlled by separately considering the influence of the acceleration in the rotation plane of 4 to 4 and the influence of the acceleration in the direction perpendicular to the rotation plane of the hands 2 to 4 independent of the pointer position. Therefore, the second hand 4 can be stably rotated regardless of the direction and magnitude of the acceleration.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, in the above embodiment, when acceleration is applied to the analog electronic timepiece and the hand movement is likely to stop, the effective value of the drive pulse is increased by increasing the width of the drive pulse supplied to the step motors 23 and 24. Although the pointer is operated, the effective value of the drive pulse can also be increased by increasing the voltage (current) of the drive pulse.

  Further, in the above embodiment, after the interrupting operation of the hand movement operation is started, the acceleration data is read and determined in this interrupt processing, and the drive pulse width is set. It is also possible to read the acceleration data and set the drive pulse width, and to output a command to the drive circuits 83 and 84 based on the result of this setting process during the hand movement operation.

  In the above embodiment, two types of drive pulse widths are set based on a constant reference value and a pointer position with respect to the acceleration direction. However, the present invention is not limited to this setting method. For example, the width of the drive pulse may be set in finer steps based on the magnitude of acceleration, or the drive pulse may be set in finer steps based on the angle between the acceleration direction and the pointer position. It is also possible to set the width.

  In the above embodiment, the analog electronic timepiece in which the hour hand 2 rotates in conjunction with the minute hand 3 has been described. However, in the timepiece in which the hour hand 2 and the minute hand 3 are driven independently, the hands 2 The drive pulse width of ˜4 may be controlled. Alternatively, it can be used for an analog electronic timepiece further provided with other function hands. In addition, the configurations and numerical values shown in the details of the embodiments can be appropriately changed without departing from the gist of the present invention.

1, 1a Analog electronic timepiece 2 Hour hand 3 Minute hand 4 Second hand 23, 24 Step motor 32, 33, 34 Wheel train mechanism 80 Control unit 81 RAM
82 ROM
83, 84 Drive circuit 88 Oscillation circuit 89 Dividing circuit 90 Switch unit 91 2-axis acceleration sensor 92, 94 A / D conversion circuit 93 1-axis acceleration sensor

Claims (5)

In an analog electronic timepiece that moves the hands with a step motor and displays the time,
An acceleration detecting means for detecting acceleration of two axes orthogonal to each other in the plane of rotation of the pointer;
Acceleration direction calculating means for obtaining the direction of acceleration based on the output of the acceleration detecting means;
The effective value of the drive pulse supplied to the step motor is changed according to the magnitude of the acceleration detected by the acceleration detecting means and the direction of the acceleration calculated by the acceleration direction calculating means and the position of the pointer. Drive pulse control means for causing
Analog electronic watch with The drive pulse control means includes
The effective value of the drive pulse supplied to the step motor is increased when a component in the acceleration direction detected by the acceleration direction calculation means is included in the hand movement direction of the pointer. The analog electronic watch described. The drive pulse control means includes
The effective value of the drive pulse supplied to the step motor is not increased when the magnitude of acceleration in the rotation plane of the pointer is equal to or smaller than a predetermined second reference value. Analog electronic clock. The effective value of the driving pulse, the expansion and contraction of the pulse width, or an analog electronic timepiece according to claim 1, wherein the change by the pulse voltage. The analog electronic timepiece according to claim 1, wherein the pointer is a second hand.

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