Kabushiki Kaisha Daini Seikosha

Seiko Instruments & Electronics Ltd.

Yukio Ikehata

Hideyuki Nakao

Masataka Ikenishi

Shozo Kushida

Isamu Nishida

Shigeyuki Masuda

Tadahiro Kikuchi

Kenichi Ono

Nobuo Obara

Yasuhiro Kasai

Nobuo Ohara

Yasuhiro Kawanishi

An electronic timepiece having a step motor is driven by a drive circuit which selectively produces either continuous hand-carrying pulses or stepwise hand-carrying pulses. The continuous hand-carrying pulses are produced by a continuous hand-carrying waveform shaping circuit connected to a frequency divider, and the stepwise hand-carrying pulses are produced by a stepwise hand-carrying waveform shaping circuit connected to the frequency divider. The selection of either the continuous hand-carrying pulses or the stepwise hand-carrying pulses is executed by a hand-carrying mode selection circuit in response to the operation of a reset switch for resetting the frequency divider.

Electronic timepiece operable in continuous and stepwise modes

An electronic timepiece has a timepiece standard generator, a frequency divider having a resettable terminal, a circuit for controlling an optically displaying device connected to the frequency divider, a circuit for controlling a hand displaying device connected to the frequency divider, a below second linking control circuit for detecting first the content of the frequency divider in response to the operation of either first switch for resetting to zero the digit of second of the optically displaying device or second switch for initiating to act the hand displaying device and for resetting next to zero the digit of second of the optically displaying device and initiating to act the hand displaying device after the time adjustment of the hand displaying device respectively. At the time of detection of a below second linking control circuit, the below second linking control circuit controls to advance by one second on the hand displaying device if the content of the frequency divider is 0.5 seconds and over at the resetting state of second-digit of the optically displaying device and controls to advance by one second on the optically displaying device if the content of the frequency divider is 0.5 seconds and over at the stepping state of the hand displaying device, whereby after the adjustment of either the optically displaying device or the hand displaying device, the time indication of the optically displaying device is linked to the time indication of the hand displaying device within 0.5 seconds.

Electronic timepiece

In an electronic timepiece, a baseplate having a pair of opposed major surfaces, a magnetic shield plate disposed in continuous contact with one of the major surfaces and a stator disposed on the other of the major surfaces. A pin is inserted through the magnetic shield plate, baseplate and stator and includes a head portion bearing against the magnetic shield plate, and is engaged by a screw having a head bearing against the stator for fixing the shield plate, baseplate and stator between the head portion and the screw head. The shield plate includes an inwardly sloped aperture for receiving the head portion of the pin, and the head portion has a tapered peripheral surface complementary to the inwardly sloped surface of the aperture. The head portion is thinner than the shield plate and does not protrude beyond a surface of the shield plate, and because the shield plate is in continuous contact with the base plate it is not deformed by the head portion of the pin bearing thereagainst.

Magnetic shield plate mounting structure for an electronic timepiece

Second adjustment system in an electronic watch employing a quartz oscillator as a time base. The watch comprises a standard oscillating circuit including the quartz oscillator, a divider, a driving circuit, and a converter. The divider produces several oscillatory output signals of different frequency so as to produce diverse time signals. A time signal selection switch selects output among these outputs. The selected output time signal corresponds to the signal required for adjusting a time delay or a time advance of the seconds indicated by the watch. An incorrect time is corrected during normal watch operation by this second adjustment system.

Second adjustment system in an electronic watch

A switching mechanism in an electronic watch including a clicking mechanism comprising a clicking cam which is mounted for rotation on an operative rod and a spring which is fixed to a base plate. The clicking cam is provided with a peripheral projecting portion. The spring is provided with a convex portion. In a switching operation, the projecting portion of the cam engages with the convex portion of the spring during the rotation of the cam which is rotated together with the operative rod. After passing through a dead point where the cam disengages with the spring, the cam continues to rotate due to the restoring force of the spring. Then, a click sound is produced at the engagement and the disengagement therebetween.

Switching mechanism in an electronic watch

The switching mechanism for setting the time in an electronic wrist watch comprises a switch blade actuated by a double-lobe cam which is connected by a lost-motion coupling with a coaxial transmission wheel having at its periphery gear teeth meshing with a winding pinion on a round part of the winding stem which is perpendicular to the axis of the transmission wheel and cam. The winding pinion and a clutch wheel which is rotatable with the winding stem have rectangular teeth which are engageable with each other to connect the winding pinion with the winding stem. A protuberance of a cam spring is engageable with one lobe of the cam to restrain rotation of the cam until the lost-motion coupling reaches the end of its travel. The construction permits its use in a thin watch.

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Tokyo, Japan

Yukio Ikehata