Kabushiki Kaisha Daini Seikosha

Joichi Miyazaki

Masataka Ikenishi

Shozo Kushida

Hiromasa Nakanishi

Makoto Ueda

Masaharu Shida

Yasuo Kusumoto

An electronic timepiece having a stepping motor and a drive circuit responsive to a control signal for applying electrical drive pulses having polarities determined by the control signal for rotating the rotor of the stepping motor. The control circuit normally operates in a mode for applying a control signal to the drive circuit effective to control the drive circuit to apply alternate polarity electrical drive pulses to rotate the stepping motor rotor in a normal direction. Resetting circuitry is operable for correcting the time kept by the timepiece. A detecting circuit detects whether the stepping motor rotor is in a position to be rotated by a forthcoming drive pulse after resetting. If the stepping motor rotor is not in a position for rotation a detection circuit signal is applied to the control circuit so that the control signal controls the drive circuit to apply an electrical pulse effective to rotate the stepping motor rotor after resetting. Consequently, after resetting the immediately forthcoming drive pulse will have a polarity effective to rotate the stepping motor rotor and no time will be lost.

Electronic watch

A calendar mechanism of a motor driven analog timepiece is automatically adjusted, at the end of a 30-day month to the first day of the next month. A month detecting circuit distinguishes between 30-day months and 31-day months, and at the end of the 30th day of a 30-day month it controls the timepiece motor to run backward and then forward at a relatively high speed to change the calendar to the first day of the month. Circuitry is also provided to distinguish between 28 and 29-day months, and to correct the date displayed at the end of February in a similar manner.

Correcting device for calendar in an analog type electronic watch

In an electronic watch a non-operation detecting circuit detects the non-operative condition of the stepping motor of the watch and produces a non-operation signal each time the stepping motor fails to operate in response to the standard pulse which drives the same. A counter counts the number of non-operation signals and stores the count for later use. A rotation detecting circuit detects the resumption of operation of the stepping motor in response to the standard pulse from the non-operative condition and a quick feed control circuit quickly advances the stepping motor in response to an input from the rotation detection circuit by thereafter supplying, instead of the standard pulses, the quick feed pulses to the drive circuit for the motor equal in number to the number of the non-operation signals counted in the counter. In this way the corrected time will be displayed by the watch even after being rendered inoperative as a result of an external condition such as low temperature or a high strength DC magnetic field.

An electronic watch movement including a base plate having a pair of opposite major surfaces. A calendar ring is disposed confronting a first of the major surfaces, and a circuit board is disposed confronting the second major surface. The calendar ring has a narrow central annular portion, a wide peripheral skirt portion circumscribing the narrow central annular portion and a circular step portion extending between the narrow central annular portion and the wide peripheral skirt portion. The skirt portion of the calendar ring is spaced further from the base plate then the central annular portion of the calendar ring. The base plate has openings therethrough opposite the skirt portion of the calendar ring, and electronic watch components are mounted on the major surface of the circuit board and extend through the openings through the base plate beyond the narrow central annular portion of the calendar ring toward the wide peripheral skirt portion of the calendar ring. The electronic watch components are oriented to minimize the thickness of the electronic watch movement.

A stop watch comprising a second hand and a subsecond hand includes manually actuatable switches for producing start, stop and reset instruction signals. A first stepping motor and a first drive controller for the stepping motor drives the second hand, while a second stepping motor and a second drive controller drives the subsecond hand. The second drive controller includes a counter for counting subsecond clock pulses in response to the start signal for effecting the display of the contents of the counter by the subsecond hand in response to the stop signal.

Stop watch

A calender mechanism comprising a cannon wheel having a gear wheel portion and a cylindrical portion extending axially from the gear wheel portion, a day star wheel mounted for rotation on a cylindrical portion of the cannon wheel, and a positioning plate. The day star wheel has an outer diameter less than that of the gear wheel portion of the cannon wheel, and the positioning plate is positioned to partially overlie the outer peripheral portion of the gear wheel portion for preventing the cannon wheel from traveling axially toward the day star wheel. The portion of the positioning plate overlying the outer peripheral portion of the cannon wheel does not extend between the day star wheel and the gear wheel portion of the cannon wheel.

Calendar mechanism of a portable timepiece

In a timepiece, a seconds gear wheel mounted for rotation on a plate, and a battery and a gear train mounted on opposite sides of the seconds gear wheel. The gear train engages the seconds gear wheel and a transducer for rotating the seconds gear wheel. The seconds gear wheel has a radius smaller than a difference between a radius of the plate and a diameter of the battery. The resulting structure is very compact.

Gear train of quartz-crystal timepiece having analogue display

A circuit board assembly for an electronic timepiece comprises a lower substrate having at least two recesses therein, an upper substrate superposed on the lower substrate and having at least two openings lying in registry with respective ones of the recesses, and a cover member superposed on the upper substrate hermetically covering the openings to thereby define at least two hermetically sealed compartments. An oscillator is housed in the one compartment and an IC chip housed in the other, both the oscillator and IC chip being electrically connected to electrodes printed on the upper face of the lower substrate. The compartment housing the oscillator is preferably maintained under vacuum and the compartment housing the IC chip is preferably maintained in an atmosphere of nitrogen gas or filled with resin material.

Growing community of inventors

Tokyo, Japan

Joichi Miyazaki