Citizen Watch Company, Ltd.

Mitsuo Onda

Takashi Toida

Fumio Nakajima

Akira Nikaido

Takayasu Machida

Singo Ichikawa

An electronic timepiece having a voltage conversion circuit for providing a different supply voltage from the timepiece battery voltage, detection means for detecting a condition in which a drive signal of relatively high voltage must be applied to an electromagnetic transducer of the timepiece, which is driven intermittently, switching means controlled by the detection means for selecting either the battery voltage or the converted voltage, and a circuit containing a capacitor which is charged by the output voltage of the switching means while the electromagnetic transducer is not being driven, and is discharged by supplying power to the transducer when the latter is driven, so that drive power is supplied to the transducer from, in effect, a low impedance source.

Electronic timepiece having a voltage conversion circuit

A rotor assembly for an electro-mechanical transducer, which comprises a rotor pinion including a pinion and a shaft concentric with the pinion, the shaft having a first portion integral with the pinion and a second portion integral with the first portion, an annular body of a permanent magnet, and a protecting support member formed as a unitary structure with the annular body by injection molding, the protecting support member having an axially extending ring portion on which the annular body is mounted, end face portions radially extending from both ends of the ring portion and retaining both faces of the annular body, and an axial projection axially extending from one of the ends of the ring portion and press fitted to the second portion of the rotor pinion at a position beyond the one of the ends of the ring portion.

Permanent magnet rotor assembly for electro-mechanical transducer

A pulse motor for clockworks and the like in which the rotor comprises two spaced-apart permanent magnetic disks mounted upon a common shaft and rotatable with respect to a stator. The stator comprises a respective pair of magnetic poles in the plane of each disk, the poles of the pair being interconnected by a shank and a coil wound upon the respective shanks, the coils lying on opposite sides of the rotor. The coils can be excited independently to cause the respective pair of poles to magnetically cooperate with the respective disk and rotate the motor in the forward or the reverse sense.

Pulse motor

A reversible pulse-motor driving circuit comprising a steady driving circuit composed of an oscillator circuit, a frequency divider circuit, a waveform conversion circuit, and a driving circuit, and a fast correction driving-circuit composed of a fast correction set-circuit, a first gate circuit, a detector circuit, a normal and reverse discrimination circuit, a conversion change-over circuit, a pulse selector circuit, a first memory circuit, a second gate circuit and a second memory circuit, whereby a user can hear a time signal delivered from a calculation circuit and only push a pushbutton to rotate the pulse motor in a reverse direction when the second hand is ahead of the correct time, and rotate the pulse motor in a forward direction when the second hand is lagging with respect to the correct time, and the use of a frequency higher than the steady driving frequency permits a fast setting of the second, minute or hour hand to the correct time. A reversible pulse motor for use in timepiece and more particularly in wrist watch is disclosed which can be rotated in forward and reverse directions by the driving circuit, which is small in size and which can operate with a minimal consumption of the electtric power.

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Oomiya, Japan

Mitsuo Onda