JPS58173479A - Electronic watch - Google Patents

Abstract

PURPOSE:To obtain a miniaturized and thin electronic wrist watch having high reliability, by AND-processing two different kinds of rotation detecting outputs, and controlling the driving of a step motor. CONSTITUTION:When driving voltage from a driving circuit 18 is applied, a rotation detecting circuit A21 detects rotation or nonrotation of a motor 19 from induced voltage of a step motor 19. On the other hand, a rotation detecting circuit B22 detects rotation or nonrotation of the motor by detecting a rotating position from a static position of a rotor of the motor 19 in accordance with the driving voltage. outputs of these circuits 21, 22 are AND-processed by a controlling circuit 17, rotation or nonrotation of the motor 19 is decided safely and exactly, and driving pulse width applied to the motor through the driving circuit 18 is varied. According to this system for detecting a rotation of the step motor without using magnetomotive force, inertia moment, etc., the rotation is detected exactly without making the constitution large-sized, driving of the step motor is controlled as to feedback, and a miniaturized and thin electronic wrist watch having high reliability can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a hand display type electronic timepiece KWR equipped with a plurality of rotation detection means.

In recent years, with the aim of reducing the power consumption of step motors, a method has been put into practical use in which the rotation of the rotor is detected by some means and fed back to the drive circuit.

One method for detecting the rotation of the rotor is a method that utilizes the fact that the waveform of the induced voltage generated in the coil differs between rotation and non-rotation due to the free movement of the rotor after application of a drive pulse to the step motor.

FIG. 1 is a perspective view of a conventional step motor for a timepiece. FIG. 2 shows a conventional step motor drive circuit and rotation detection circuit.

After controlling the gate and driving the step motor on path 10, a closed loop is formed on path 11, and the voltage waveform induced at the terminal 11 of the detection resistor is shown in FIG. Here waveform a
is the case when the rotor rotates normally, and the waveform is when the rotor does not rotate. Both can be easily distinguished by electrically detecting whether or not a certain voltage value has been reached.

FIG. 4 shows the drive voltage waveform of a conventional correction drive system that has been put into practical use.The outline of this correction drive system is to prepare a normal drive pulse P1 and a correction drive pulse P. The normal driving pulse Plij is a pulse that drives the step motor every 1 second, and the driving pulse width is automatically changed to Kt according to the motor load condition. The correction drive pulse P is output when the rotor cannot rotate with the normal drive pulse PI and is holed.
This is a six-section DTd rotation detection section in which the pulse width is large enough to obtain a sufficiently large motor output torque.

From fg5 to figure 7, 12 [! FIG. 4 is a diagram for explaining another conventional rotation detection method that has already been put into practical use and is different from the rotation detection means described in FIGS. FIG. 5 is an example of a drive voltage waveform diagram of this conventional correction drive method. Pa
, Pb are rotation detection pulses having a pulse width so short that the step motor cannot rotate. The 6th prisoner is P1 in Figure 5.
The magnetic flux from the rotor 1 and the magnetic flux of the coil magnetomotive force after being driven by the rotor 1 are shown. The stator 2 is integral and has a rotating shaft, and contains parts 2a and 2b with small cross-sectional areas. Since the magnetic fluxes of the coil and the coil are in the same direction, the diagram shows the coil magnetic flux and rotor magnetic flux that would occur if the direction of the current flowing through the melting coil 3 was completely opposite.

In this case, the magnetic flux will be in the opposite direction.

FIG. 7 shows a drive current waveform diagram in the state shown in FIG.
The curve a in Figure 7 corresponds to Figure 6 (a), and is the current waveform that occurs when the curve bFi in Figure 7 is (1) in Figure 6. In order to identify the current waveform difference at time t, after driving at %Pl, calculate the Pa, Pb ratio output, and from that signal find out the position of the rotor's magnetic poles.If the rotor rotates at 1P-? You can know whether or not. However, both detection methods have the risk of erroneously detecting non-rotation and rotation of the rotor.

In the method of detecting the induced voltage of the rotor's free vibration, the difference in the induced voltage is determined by the characteristics of the step motor (e.g., the electromotive force of the coil, the moment of inertia of the rotor, the index torque, the viscous resistance of the oil on the rotor's rotating shaft, etc.). ). Recently, watches have become thinner and smaller, and step motors are also thinner! , the magnetomotive force, moment of inertia, etc., and K, which makes a difference in detection, have changed in a disadvantageous direction.

In addition, in the latter method, if the rotor comes to rest in an unstable position after the P1 drive (for example, the magnetic poles come to rest in the recessed part of the inner circumference of the stator), one or more of the following errors occur:
Neither angular rotation detection method is perfect, and a method that can safely and reliably detect rotation has not yet been perfected.

When using the corrective drive method, erroneous detection in motor rotation detection results in a delay in immediate operation, which becomes a fatal defect.

The present invention is constructed on a ladder that eliminates the above-mentioned drawbacks, and provides an electronic timepiece equipped with a step motor for a timepiece that is thin, small, highly reliable, and consumes low gravity.

FIG. 8 is a block diagram of the electronic timepiece of the present invention. The oscillation circuit 14 includes a crystal resonator and oscillates at 32768 Hi. This fF! The number is input to branch station-1 tsK,
The output is input to the waveform synthesis circuit 16. In the waveform synthesis circuit 16, the control circuit 17. Pulses necessary for the drive circuit 18, rotation detection circuit B21, and rotation detection circuit B22 are combined in waveform. Control circuit 1
7 outputs a signal to the drive circuit 18 in accordance with the output of the rotation detection circuit B of the rotation detection circuit 11. Drive circuit 18F
The rotation detection circuit A supplies drive pulses to the i-motor 19 and receives signals from the drive circuit.

Rotation detection circuit B is activated. The output of the motor 19 is the gear train,
The information is transmitted to the instruction section 20.

FIG. 9 is a diagram showing an example of a motor drive pulse according to the present invention. Pl is a normal drive pulse, which is a short pulse width for driving the motor with low power. DT is the section where the rotation of the induced voltage is detected, and Pa
, Pb is a rotation detection pulse M' based on the rotor position
S is a correction drive pulse, which is a normal drive pulse PI and is output when the rotor is not rotating.

FIG. 10 shows a flow chart of the present invention. To explain the flow of this flowchart, the initial value setting is n.
=o, N=O, and calculate the pulse width of the normal drive pulse. Set PO-2-2111sec and nFil~
Available up to 7. Since ΔPti is 124 mgHg, F1=P・+n・ΔP In this case, “12”l
It becomes l1g. Therefore, Pl is output, and then rotation detection is performed using the induced voltage of the rotor, and then rotation detection B from the stationary position is performed. Take the logical product of both. Result #:t! Shown in l.

In other words, in order to avoid erroneously detecting non-rotation as rotation, a correction drive pulse P is output when 0 rotation is erroneously detected as non-rotation, but since the rotor ti is not rotated, the actual The clock does not lag or advance by 1, but at this time,
Motor power consumption increases.

According to llK, if non-rotation is detected, the correction drive nozzle PI is output, n: 1 (-plus. If rotation is mistakenly detected)
Add i=1'li and repeat until 1=44. N
= 64, mKOt is inserted, nti is forcibly decremented by minus 1, and the normal drive nose Fttj is shortened. When this operation is repeated, the pulse width of the normal drive pulse P1 changes depending on the load fluctuation trap, and the pulse width becomes the minimum pulse width at which the motor can rotate by itself.

FIG. 11 shows an embodiment of the drive circuit 9 rotation detection circuit A9 rotation detection circuit B of the present invention. FIG. 912 shows a timing chart of signals applied to the input gate of FIG.

The 7M08FWT1000 source in Figure 11 is PM08
ν connected to the source of T101 and with voltage mw 'VD
Connected to D. PMOB'FICT100 10
Each number of the timing chart shown in FIG. 12 is connected to the gate human power Vt of No. 1. The drain of PMO8FKT100 is the drain of tiMO87KTE102,
One end of the coil 104 is connected to the drain of the MMO8FIT 109 via the negative input 9 of the coniprator 119 and the same rotation detection resistor 106 . PM08F! l1T101
The drain of NMO8FKT103, the negative input of comparator 118 at the other end of coil 104, and NMO8FICT1
Connected to the drain of 10. NMO8FIT 1
02, the gate 105 receives signals 121 and 12 in FIG.
4 is connected.

NMO8FKT 102, I Q S (D source Id
The power supply voltage ovss, the negative input of the comparator 114, the transmitter "iy gate 111, lJMO8FI!i' are connected to each other through the rotation detection resistor 105.
Connected to the drain of r108. 8M087I7
A signal 130 in FIG. 12 is connected to the gate input of 108. The role of this FET is to allow current to flow through the rotation detection resistor 105 when detecting the rotor stationary position.
01FF. NMO8Fl! ! T 108
The source of is connected to the power supply voltage ys-. N.M.O.
Signals 125 and 126 in FIG. 12 are input to the gate inputs of the 8FETs 109 and 110, and the rotation detection voltage due to free vibration of the rotor is amplified. , 8M08F
The sources of ET109 and 110 are connected to each other by Vcl,
It is connected to the W weight voltage vl. Resistance 115, 116
#'i, the reference pressure input to the positive inputs of comparators 11B and 119 is created by resistance division. NMOFIPE
T117 limits the rotation detection time and resistors 115, 11
FC is provided to reduce the power consumption flowing through 6.
It is an FET. The signal 12B is inputted to the gate 91. A charge is stored in a capacitor 113 and connected to the positive input of a comparator 114.

- Differences in current waveforms depending on the evening stationary position fIL are detected. When the signals output from these two rotation detection methods are input into an AND gate, a table is obtained. Based on the output signals in this table, it is extremely easy to operate the control circuit and output appropriate pulses to the motor through the drive circuit.

As described above, according to the present invention, the logical product of the two types of ship-ship detection methods is taken and the flaw signal is fed back to the drive circuit, so it is thin, small, highly reliable, and low in consumption. This makes it possible to drive a step motor using electric power, which has a great effect on making wristwatches more reliable, thinner, and smaller.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a conventional step motor for a watch, Fig. 2 is a conventional step motor drive circuit diagram and rotation detection circuit diagram, and Fig. 3 is a diagram showing an example of rotation detection using a conventional coil induced voltage. Figure 4 is the drive voltage waveform diagram of the conventional correction drive method, and the fifth
The figure is a drive voltage waveform diagram of another conventional correction drive method. Figures 6 (a) and (b) are plan views showing the magnetic flux of the step motor, respectively. Figure 7 is rotation detection using motor drive current waveform detection. . A diagram showing an example of fI! Fig. 48 is a block diagram of the electronic timepiece of the present invention, Fig. 9 is a diagram of the drive side voltage ts and shape of the present invention, Fig. 10 is a flowchart of the present invention, and Fig. 11 is a drive circuit one rotation detection circuit according to the present invention. FIG. 12 is a timing chart of the input waveform according to FIG. 11. FIG. 1... Rotor 2... Stator 3...
・Coil 14... Common, swing circuit 15... Branch circuit 16... Waveform synthesis circuit 17... Control circuit 18... Section side circuit 19... Motor
20. #...-Column designator 21... Rotation detection circuit A 22... Interval detection circuit 5 or more Applicant Daini Seiko Co., Ltd. Agent Patent attorney Mogami Tsutomu Figure 1 Figure 2 Figure 1 o Figure l1 figure

Claims (2)

[Claims] (1) A multi-column clock consisting of at least an oscillation circuit 1 frequency dividing circuit, a waveform synthesis circuit, a drive circuit, a step motor, and a wheel train from an indicating section, is equipped with a rotation detection circuit using a plurality of means, and according to its output. Drive circuit wJ control signal f
The electronic clock is designed with a long-lasting control circuit and is a reliable indicator. (2) The multi-column timepiece according to claim 1, characterized in that the electric means of the step motor differs depending on the logical product of the outputs of the plurality of rotation detection means. ``(3) In claim 2, the Shigeko clock is a car in which the pulse width of the step motor changes.