JPH1010245A - Motor control circuit of electronic timepiece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor control circuit structure of an electronic timepiece of high reliability for indication precision and stop of pointers without fluctuation of the pointers since recently the basic performance of the timepiece has begun to be reconsidered and the importance of movement of the pointers as the origin of the basic performance is attached thereto. SOLUTION: The motor control circuit of an electronic timepiece has a first drive pulse P1a, a first detection means for detecting rotation of a motor by the drive pulse, a second drive pulse P2b and a second detection means for detecting the rotation of the motor by the drive pulse. Constitution is performed in that an output interval between the first drive pulse and the second drive pulse is 50ms or lower and a correction drive pulse for the first and second drive pulses is output within 50ms after output of the first and second drive pulse in the case where non-rotation of the step motor is detected with the first and second detection means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a motor control circuit for an electronic timepiece.

[0002]

2. Description of the Related Art A conventional motor control circuit structure has a speed of one second per second.
Times, one drive pulse is output.
Two correction drive pulses are provided.

[0003]

However, the prior art has the following problems.

[0004] In the structure of the reduction gear train from the rotor, the meshing portion of each gear must be engaged from the reference setting state in order to prevent the gear meshing portion from being stained or biting due to factors such as variation in parts and tooth profile accuracy. It is necessary to secure a gap (hereinafter referred to as backlash). For this reason, due to the backlash between the teeth, the second display position shifts, and the shift from the dial graduation occurs.

[0005] This is because the movement of the rotor is normally shown in FIG.
The rotor does not drive every 180 ° as shown in Fig. 1), but the rotor attenuates while repeating vibration to a stable point after rotation. Since the vehicle is stationary, the second indicating vehicle is also stationary while vibrating through the speed reduction train.

However, even if the rotor is accurately stopped at a stable point due to the influence of the backlash of each gear described above, the seconds display wheel has a rotor whose amplitude becomes smaller than the amount of rotation caused by the backlash of the gear when the rotor amplitude is attenuated. Will not follow the movement of

For this reason, the stationary position of the display vehicle varies in the range of the backlash.

In order to increase the torque possessed by the display wheel by the conventional motor control circuit structure, the torque possessed by the rotor is increased, and a coil block in which more coils are wound to rotate the rotor is required. Plane and cross-sectional space will be required.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to make it possible to use a small-space motor to indicate the hands of a hand while the basic performance of a timepiece is recently being reviewed in the market. An object of the present invention is to provide a motor control circuit structure of an electronic timepiece that improves the accuracy and increases the torque possessed by a display vehicle.

[0010]

A motor control circuit for an electronic timepiece according to the present invention has a detecting means for generating first and second drive pulses, each of which detects the rotation of a step motor. When the output interval between the first and second drive pulses is less than or equal to 50 ms and the first and second detectors detect non-rotation of the step motor, the correction drive pulse for the first and second drive pulses is changed to the first and second drive pulses. The timing control circuit and the pulse synthesizing circuit are configured so as to output within 50 ms after the output.

[0011]

FIG. 1 shows a timing chart of an embodiment of the present invention.

O1 and O2 are terminal names of the terminals to which the driving pulses of the step motor are output.

The motor control circuit outputs the following pulses from the O1 terminal and the O2 terminal at the timing shown in FIG.

The pulse P1a is a normal step motor drive pulse output from the O1 terminal.

The pulse SP2a is a pulse output from the terminal O1 for detecting whether or not the stepping motor has rotated based on the pulse P1a.

The pulse P1b is a normal stepping motor drive pulse output from the O2 terminal.

The pulse SP2b is a pulse output from the O2 terminal for detecting whether or not the stepping motor has rotated by the pulse P1b.

From the start of output of pulse P1a to pulse P1b
The motor control circuit is configured so that the time until the start of the output is less than 50 msec.

The pulse P2a is a correction drive pulse that is output from the O1 terminal only when the step motor does not rotate due to the pulse P1a and rotates the step motor.

The pulse P2b is a correction drive pulse that is output from the O2 terminal only when the step motor does not rotate due to the pulse P1b and rotates the step motor.

The step motor includes a coil, a stator and a rotor.

Usually, the analog quartz second hand moves every second.

In order to move the second hand every second without impairing this movement and to increase the torque possessed by the second indicating car, the rotor is rotated 360 ° within one second to reduce the speed reduction ratio from the rotor to the second indicating car. Twice as much.

Pulses P1a and P1b for rotating the rotor
The output timing is set to 50 ms or less at which a human cannot recognize that two pulses are output by the movement of the second hand.

FIG. 3 shows a block diagram of an embodiment of the present invention.

The terminal 321 is connected to O1 in FIG.
1 terminal 321) and the terminal 322
2 (hereinafter referred to as O2 terminal 322).

The original frequency obtained from the oscillation circuit 301 is generated at a predetermined frequency by the frequency dividing circuit 302, and the timing control circuit 303 controls the timing of the entire circuit.

In the P1a + SP2a generation circuit 304, O
A drive pulse P1a output from one terminal 321 and a rotation detection pulse SP2a for detecting by the rotation detection circuit 312 whether or not the step motor 320 has rotated by the drive pulse P1a are created.

In the P1b + SP2b generation circuit 305, O
A drive pulse P1b output from the two terminals 322 and a rotation detection pulse SP2b for the rotation detection circuit 312 to detect whether or not the step motor 320 has rotated by the drive pulse P1b are created.

In the P2a generation circuit, a correction drive pulse P2a output from the O1 terminal 321 shown in FIG. 1 is created.

In the P2b generating circuit, a correction driving pulse P2a output from the O2 terminal 322 shown in FIG. 1 is created.

The polarity switching circuit 313 detects the drive pulse P1
a, rotation detection pulse SP2a, correction drive pulse P2a
Are output from the O1 terminal 321 and the drive pulse P1b, the rotation detection pulse SP2b, and the correction drive pulse P2b are output from the O2 terminal 322, respectively.

In the rotation detecting circuit 312, the driving pulse P1
The rotation detection pulse SP2a or SP2b detects whether the step motor 320 is rotated by a or P1b, and controls the output permission / prohibition of the correction drive pulse P2a or P2b based on the result.

The polarity switching circuit 313 detects the drive pulse P1
a, a rotation detection pulse SP2a, a correction drive pulse P2a,
Are output from the O1 terminal 321 and the respective pulses of the drive pulse P1b, the rotation detection pulse SP2b, and the correction drive pulse P2b are output from the O2 terminal 322.

Next, a method of controlling each pulse will be described.

FIG. 4 is a timing chart showing the operation of each circuit in FIG.

First, the timing control circuit 303 outputs a full correction pulse output permission signal 324 (hereinafter, all correction permission signal 324) and a correction drive pulse P2b permission signal 325 (hereinafter, P2b permission signal) output from the rotation detection circuit 312. 325) is set to Low,
Polarity control signal 326 output from polarity switching circuit 313
Is set to High.

Next, the driving pulse P1a is supplied to the O1 terminal 321.
When the step motor 320 rotates, the all correction permission signal 324 is held at Low.

Then, since the AND gate 309 becomes Low, the correction drive pulse P2a is not output.

Thereafter, within 50 ms immediately before the output of the drive pulse P1a, the polarity control signal 326 becomes Low, and thereafter the drive pulse P2b is output from the O2 terminal 322.

When the stepping motor 320 is rotated by the drive pulse P1b, the P2b permission signal 325 is held at Low, so that the correction drive pulse P2
b is not output.

As described above, when the step motor 320 continues to rotate by the drive pulses P1a and P1b, the correction pulses P2a and P2b are not output.

FIG. 5 is a timing chart of the block diagram 3 when the stepping motor 320 is not rotated by the driving pulse P1a.

When the step motor 320 is not rotated by the driving pulse P1a, the output of the driving pulse P1b is prohibited and the output of the correction driving pulses P2a and P2b is permitted because the all correction pulse permission signal 324 becomes High. Is done.

Accordingly, when the motor is not rotating at the drive pulse P1a, the step motor 320 rotates at the correction drive pulse P2a output from the O1 terminal 321 and then the polarity control signal 326 becomes Low and is output from the O2 terminal 322. The rotation is controlled by the correction driving pulse P2b.

FIG. 6 is a timing chart in the case of rotation at the drive pulse P1a and non-rotation at the drive pulse P1b.

The output of the correction drive pulse P2a is prohibited because the rotation is performed by the drive pulse P1a, and when the rotation is not performed at P1b, the correction drive pulse P2b is output from the O2 terminal 322 because the P2b permission signal 325 becomes High. Is output.

Accordingly, the stepping motor 32 rotates when the driving pulse P1a rotates and the driving pulse P1b does not rotate.
0 is rotated by the drive pulse P1a and the correction pulse P2b.

Although the present invention has been described in detail based on the embodiments, the present invention is not limited to the embodiments.

For example, in the case of non-rotation due to the drive pulse P1a, the drive pulse P1a and the rotation detection pulse SP2b are not inhibited, and 50
The correction drive pulse P2a is output within ms, and then the drive pulse P1b is output within 50ms, and the rotation detection pulse SP2b outputs the correction drive pulse P2b in the case of non-rotation detection in the rotation detection circuit 312. May be.

[0051]

The conventional second hand moves once per second for one second.

In the present invention, the rotor rotates twice as usual.
Since the output timing of the two pulses for rotating the rotor doubles the speed reduction ratio from the rotor to the second indicating car, the movement of the second hand increases the torque possessed by the second wheel as before and the pointing accuracy of the hand. Can be improved.

Except when the stepping motor is not rotated by the normal drive pulse, the power consumption is low because no correction pulse having a longer pulse width is output.

[Brief description of the drawings]

FIG. 1 is a timing chart of an embodiment of the present invention.

FIG. 2 is an explanatory view of the movement of a rotor.

FIG. 3 is a circuit block diagram of an embodiment of the present invention.

FIG. 4 is a timing chart showing the operation of the circuit block diagram of the embodiment of the present invention.

FIG. 5 is a timing chart showing the operation of the circuit block diagram according to the embodiment of the present invention.

FIG. 6 is a timing chart showing the operation of the circuit block diagram of the embodiment of the present invention.

[Explanation of symbols]

P1a: First drive pulse P2b: Second drive pulse SP2a: Step motor rotation detection pulse by first drive pulse SP2b: Step motor rotation detection pulse by second drive pulse P1a: Correction drive pulse of first drive pulse P1b: Second Correction of drive pulse Drive pulse 303: Timing control circuit 304: P1a + SP2a generation circuit 305: P1b + SP2b generation circuit 306: P2a generation circuit 307: P2b generation circuit 312: Rotation detection circuit 313: Polarity switching circuit 320: Step motor 320 321: Terminal O1 322: terminal O2

Claims (1)

[Claims] An oscillation circuit for generating a reference signal; a frequency dividing circuit for dividing the reference signal; a pulse synthesizing circuit for generating a pulse necessary for driving a step motor from an output of the frequency dividing circuit; An electronic timepiece having a step motor drive circuit to generate, a timing control circuit to perform timing control of the whole circuit, and a step motor driven by the drive pulse, wherein a step motor driven by a first drive pulse and the first drive pulse A first detecting means for detecting rotation; a second detecting means for detecting rotation of the stepping motor based on a second driving pulse and the second driving pulse, wherein the first driving pulse and the second Drive pulse output interval is 50ms
When the non-rotation of the step motor is detected by the first and second detection means, a correction drive pulse for the first and second drive pulses is output within 50 ms after the output of the first and second drive pulses. A motor control circuit for an electronic timepiece, wherein the timing control circuit and the pulse synthesizing circuit are configured as described above.