Kabushiki Kaisha Daini Seikosha

Seiko Instruments & Electronics Ltd.

Masaharu Shida

Makoto Ueda

Akira Torisawa

Masaaki Mandai

Katsuhiko Sato

Kazuhiro Asano

Shuji Otawa

Katsuhiko Satoh

Masataka Ikenishi

Shozo Kushida

Joichi Miyazaki

Hiromasa Nakanishi

Shuji Owada

Kenichi Ono

Takashi Ishida

Jun Ueda

Disclosed is an analogue alarm electronic timepiece having a time hand. The time hand is used as both alarm setting time hand and time display hand. The analogue alarm electronic timepiece comprises a reversible motor, an electronic circuit including a driving circuit for the reversible motor and means for counting and storing at least two kinds of relative time differences selected from the group consisting of the relative time difference between the present time and alarm time, the relative time difference between the alarm time and the display time, and the relative time differences between the alarm time and the display time, and an electronic acoustic transducer.

Analogue alarm electronic timepiece

An analog electronic timepiece comprises a stepping motor having a stator, rotor and drive coil, and electronic circuitry for periodically energizing the drive coil in two distinct excitation states to rotationally drive the rotor in a stepwise manner. The electronic circuitry effects sequential energization of the drive coil in first a full excitation state which is effective to at least initiate driving of the rotor from an initial position through a predetermined angle of rotation to a new position, and then in an intermediate excitation state which is effective to ensure completion of the driving of the rotor through the predetermined angle of rotation by preventing return rotation of the rotor after the rotor has advanced through a certain angular extent towards its new position. A method of operating a stepping motor of an analog electronic timepiece comprises periodically energizing the drive coil of the stepping motor by first energizing the drive coil in a discrete full excitation state to initiate driving of the rotor through one rotational step, and then energizing the drive coil in a discrete intermediate excitation state to complete the driving of the rotor through the rotational step.

Analog electronic timepiece drive circuitry for energizing stepping

A driver circuit for a stepping motor having a coil, a stator and a rotor receives pulse signals from a pulse signal generator to rotationally drive the rotor. A rotation detection circuit comprises switching circuitry switchable between a high impedance loop formed of the coil and a high impedance element and a low impedance loop formed of the coil and a low impedance element, and means for detecting the voltage induced in the coil. After a pulse signal is applied to the stepping motor, the switching circuitry forms the high impedance loop and the detecting means compares the voltage developed across the high impedance element with a predetermined voltage to thereby detect the rotation and non-rotation states of the rotor.

Electronic timepiece

An electronic timepiece having a stepping motor includes a power source, an oscillating circuit, a dividing circuit connected to the oscillating circuit, and a wave shaping circuit receptive of a plurality of output signals produced from the dividing circuit to produce a plurality of controlling signals. A controlling circuit receives the controlling signals and controls a driving circuit. The power source is connected to a detecting voltage circuit by which the variation of the supply voltage of the power source is detected, and a normal waveform or an intermittent waveform is selectively applied to the stepping motor according to the variation of the supply voltage. As a result, the power consumption of the steppng motor is controlled at a constant level, even if the supply voltage of the power source is higher than the optimum voltage of the stepping motor and even if the supply voltage varies.

An electronic timepiece comprising a power source, an electronic circuit, a stepping motor, and a detecting device for detecting a rotor movement after the stepping motor is driven. The electronic circuit includes a power source voltage detecting circuit and driving power controlling device which intermits driving pulses of the stepping motor according to an output of the voltage detecting circuit so that the driving force is substantially constant and the power consumption is decreased.

Electronic timepiece having a stepping motor and driving circuit

In an analog electronic watch having a calendar display the power required during change of the calendar display, about 6 hours out of 24, is greater than at other times. In order to effect economy in power consumption, the pulse for driving the watch motor during the time other than the period in which the calendar display is being changed is only sufficient to drive the time indicating means. In case the motor fails to step when such pulse is applied, this is detected by a detecting circuit and a corrective drive pulse is applied to the motor so as to drive it.

Electronic watch

An analog electronic timepiece has a stepping motor for rotationally driving the timepiece hands. The motor is driven by normal driving pulses during normal load conditions and in the event the normal driving pulses are unable to effect rotation of the motor, correction driving pulses of longer pulse width than the normal driving pulses are used. A detection circuit detects whether or not the motor has rotated by switching a resistance element in series with the motor drive coil after the application of each normal driving pulse. Rotation and non-rotation of the motor is determined by measuring the voltage across the resistance element and comparing the measured voltage with a reference voltage.

An analogue alarm electronic timepiece has electronic circuitry for controlling the drive of the time-indicating hands by a reversible stepping motor to selectively position the hands at desired alarm time and display time settings. Externally operable switches control the operation of the electronic circuitry and enable re-positioning of the hands by the motor to the previously set alarm time so that the user of the timepiece may confirm the alarm time setting. The electronic circuit includes a first settable memory means for storing the time difference between the alarm time and the present time, and a second settable memory means for storing the time difference between the present time and the display time. First means are provided for detecting coincidences between the alarm time and the present time. Second means are provided for detecting coincidence between the present time and the display time.

An electronic timepiece has a stepping motor comprised of a stator, rotor and coil, and circuitry for producing and applying driving pulses to the coil to effect stepwise rotation of the rotor. The presence of an external alternating magnetic field is detected by switching the coil from an open-circuit condition to a low impedance loop comprised of the coil and a low impedance element. The rotation of the rotor is detected by alternately switching the coil between the low impedance loop and a high impedance loop comprised of the coil and a high impedance element. Control circuitry controls the switching operations to ensure that the magnetic field detection and the rotor rotation detection are carried out at different times.

Detection device of electronic timepiece

An electronic timepiece having a stepping motor including a stator, rotor and coil, a driving circuit for applying driving pulses to the coil, an oscillating circuit for generating a time standard signal and a dividing circuit for dividing the time standard signal, is provided with a pulse combining circuit receptive of the output of the dividing circuit for producing a correction driving pulse having sufficient effective power to drive the motor under worst case conditions, a detector for detecting the rotation or non-rotation condition of the rotor after the application to the coil by the driving circuit of a normal driving pulse having less effective power than the correction driving pulse, and a controller for the driving circuit to apply normal driving pulses to the coil and responsive to the output of the detector to apply a correction driving pulse when a non-rotation condition is detected. The power consumption due to the pulse driving of the motor is minimized by incrementally decreasing the effective power of successive normal driving pulses and by incrementally increasing the effective power of successive normal driving pulses in response to the detection of a non-rotation condition by the detector.

An electronic timepiece has a stepping motor comprised of a stator, rotor and driving coil. A wave shaping circuit produces normal driving pulses and correction driving pulses having a longer pulse width than the normal driving pulses. A rotor rotation detection device detects rotation and non-rotation of the rotor after normal driving pulses are applied to the driving coil and in response to detection of a non-rotation condition, a correction driving pulse is applied to the driving coil. A magnetic field detection device detects the presence and absence of an external alternating magnetic field and in response to detection of a magnetic field, a driving pulse of longer pulse width than the correction driving pulses is applied to the driving coil to effect rotor rotation. The magnetic field detection device operates before the normal driving pulses are applied to the driving coil so that in the event of detection of a magnetic field, a driving pulse of sufficiently long pulse width will be applied to the driving coil to effect rotor rotation. In response to detection of an external alternating magnetic field by the magnetic field detection device, operation of the rotor rotation detection device is inhibited thereby conserving power and preventing mis-operation of the stepping motor.

An electronic timepiece includes a stepping motor having a stator, a drive coil and a rotor which is driven in one of at least two different states. The state of the driving motor is changed in response to a change in the load of the motor or in response to the locating of the motor in an external magnetic field.

An electronic timepiece of the type having a frequency dividing circuit, and a drive circuit for driving a motor having a rotor, a stator and a driving coil, is provided with a magnetic field detection device comprised of a low impedance closed loop including a low resistance element and the driving coil and a high impedance closed loop including a high resistance element and the driving coil. The driving coil develops an induced voltage when placed in an external alternating magnetic field and also functions to drive the rotor. The strength of the alternating magnetic field is measured by the voltage level developed across the high resistance element and the measuring sensitivity is improved by alternately switching between the low impedance closed loop and the high impedance closed loop. In response to the detection output of the magnetic field detection device, the effective power applied to the driving coil is increased so that the motor performance is not adversely affected by the external alternating magnetic field.

Magnetic field detection device for electronic timepiece

A load measuring device for a stepping motor of an analogue electronic timepiece having a stator, a rotor and a coil includes a pulse generator for producing a range of different pulse width normal driving pulses and a driving circuit for successively applying the driving pulses to the motor. A detector detects the rotation and non-rotation state of the rotor in response to the application of each driving pulse and a control circuit is responsive to the detection by the detector for controlling the application by the driving circuit of the minimum pulse width normal driving pulse capable of driving the motor. Each minimum pulse width driving pulse corresponds to the load on the motor at that time and an analyzer analyzes the pulse width of the driving pulses to thereby indicate the load on the motor.

Load measuring device for the gear train of a timepiece

In an electronic timepiece, a motor is driven by a pulse having a shorter pulse width than the conventional driving pulse and afterwards, a detection pulse is applied to the motor coil so as to determine rotation of the rotor. If the rotor fails to rotate a correction is effected by driving the motor by a pulse having a pulse width greater than the normal driving pulse.

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Tokyo, Japan

Masaharu Shida