Seiko Epson Corporation

Tatsuo Hara

Joji Kitahara

Masatoshi Moteki

Fumio Takagi

Eiichi Nagasaka

Yoshihiko Momose

Yasuhiro Oshima

Osamu Takahashi

Hiroyuki Kojima

Toshiaki Yanagisawa

Hidenori Makiba

Kenichi Michibata

Yoshiaki Oguchi

A magnetic core portion, a residual base material portion, and a connecting portionare formed by pressing from a base material. NotchesA are formed at a peripheral edge of the magnetic core portion, which is bent in the direction of the plate thickness to form a temporary fixing portion. When base materialsare overlapped to cut the magnetic core portionsfrom the connecting portion, the magnetic core portionsare pressed in directions toward one another so that the temporary fixing portionis filled between notchesA in the other magnetic core portion, to fix temporarily the other magnetic core portions. Since the magnetic core portionsare temporarily and simultaneously fixed by pressing in a cutting step normally carried out, the magnetic core portions can be temporarily fixed with ease.

Method of manufacturing magnetic head

A mainspring used as a power source for a driving mechanism is made of an amorphous metal sheet, and has an S-shaped free-exploded shape. The curvature changing point, where the curving direction of the free-exploded shape changes is formed on the inner end side of a middle point between the inner end on the winding side and the outer end serving as the other end of the inner end. Because of the high tensile stress and a low Young's modulus, the amorphous metal permits increase in mechanical energy stored in the mainspring.

Spring, mainspring, hairspring, and driving mechanism and timepiece based thereon

A mainspring used as a power source for a driving mechanism is made of an amorphous metal sheet, and has an S-shaped free-exploded shape. The curvature changing point where the curving direction of the free-exploded shape changes is formed on the inner end side of a middle point between the inner end on the winding side and the outer end serving as the other end of the inner end. Because of the high tensile stress and a low Young's modulus, the amorphous metal permits increase in mechanical energy stored in the mainspring.

Spring, power spring, hair spring, driving mechanism utilizing them, and timepiece

A timepiece, whose hands move by mechanical energy of a mainspring transmitted through a wheel train, includes a winding-up portion for accumulating energy in the mainspring, an addition and subtraction wheel train driven by addition and subtraction of accumulated energy corresponding to an amount by which the mainspring is wound up and unwound, respectively, an addition and subtraction wheel, disposed in the addition and subtraction wheel train, that rotates in correspondence with an amount by which the mainspring is wound up and unwound, and a lock mechanism actuated in response to the rotation of the addition and subtraction wheel to limit winding up and unwinding of the mainspring to a selected range of windings of the mainspring. This controls the torque output by the mainspring to a fixed range. The addition and subtraction wheel train allows efficient use of space, and can be incorporated in a watch.

Mainspring device and a winding protection structure

Mainspring device, timepiece, and method of controlling the mainspring device and the timepiece

A fourth wheel disposed in a torque transmission path and to which a second hand is mounted includes a pinion and a gear . Therefore, when the gear engages a fifth-wheel first intermediate wheel , the diametrical dimension from a center of rotation of the fourth wheel to a portion where it engages the fifth-wheel first intermediate wheel can be made large, so that, even when the fourth wheel is decentered, the amount by which the second hand gets shifted can be made small by making the effects of the decentering at the center-of-rotation side small. In addition, since the fourth wheel is disposed so as not to overlap a mainspring , the width of the mainspring can be made correspondingly small. Thus, the length of time a timepiece continues operating can be increased by increasing the torque of the mainspring without increasing the thickness of the entire timepiece.

Timepiece

A control device for stepping motor including a driving pulse supplying unit for supplying a plurality of driving pulses to a driving coil for driving a rotor. A rotation detecting pulse supplying unit supplies rotation detection pulses for detecting whether the rotor rotated. A magnetic field pulse supplying unit supplies a plurality of magnetic field detection pulses for detecting the presence of magnetic field external to said stepping motor. A detection unit determines whether the driving rotor rotated and whether a magnetic field is present. An auxiliary pulse supplying unit supplies an auxiliary pulse when either rotor was not detected or when said an external magnetic field was detected. Before the driving pulse, is output, two said magnetic field detecting means magnetic field detecting pulses having different polarities are output.

Control device for stepper motor, control method for the same, and timing device

In an electronic watch including a so-called automatic winding dynamo, structures of parts themselves and layout of the parts are improved to achieve a reduction in thickness of the electronic watch. Bearing portions for a rotational shaft (,) of a dynamo rotor (,) are made up of hole jewels (,) and ring-shaped caps (,). The cap (,) covers, from the outer side, one end surface (,) of the hole jewel (,) which locates on the side facing a dynamo rotor (,), and defines a lubricant holding annular slot (G,) between the cap and an outer circumferential surface of the rotational shaft (,). Accordingly, even with the dynamo rotor (,) rotating at a high speed, a lubricant is prevented from scattering to the surroundings from the annular slot (G,). Spacings between adjacent parts can be narrowed and the thickness of the electronic watch can be reduced.

Electronic watch

In an electronic watch including a so-called automatic winding dynamo, structures of parts themselves and layout of the parts are improved to achieve a reduction in thickness of the electronic watch. Bearing portions for a rotational shaft (211) of a dynamo rotor (21) are made up of hole jewels (212, 214) and ring-shaped caps (213, 215). The cap (215) covers, from the outer side, one end surface (216) of the hole jewel (214) which locates on the side facing a dynamo rotor (21), and defines a lubricant holding annular slot (G3) between the cap and an outer circumferential surface of the rotational shaft (211). Accordingly, even with the dynamo rotor (21) rotating at a high speed, a lubricant is prevented from scattering to the surroundings from the annular slot (G3). Spacings between adjacent parts can be narrowed and the thickness of the electronic watch can be reduced.

A device for controlling a stepping motor including a first drive pulse supply unit for supplying a first drive pulse to a drive coil for rotating a rotor. A rotation detecting pulse supply part supplies a rotation detecting pulse for detecting whether the rotor has rotated. An auxiliary pulse supply part supplies an auxiliary pulse having an effective power that is greater than the first drive pulse. A level adjustment pulse supply part reduces the effective power of the first drive decrements pulse after the rotor has rotated for a predetermined number of times consecutively. A second drive pulse supply part supplies a second drive pulse for a second predetermined number of time after the auxiliary pulse is supplied.

Stepping motor control device and method thereof and timepiece

A generator of an electronically controlled mechanical timepiece comprises a mechanical energy source, a generator, a train wheel and an electronic circuit. The train wheel connects the mechanical energy source and the generator. The generator includes a rotor, a first plate-shaped stator, a second plate-shaped stator, a pair of semi-circular stator holes and at least a first coil.

Electronically controlled mechanical timepiece

An analog indication type electronic timepiece includes a power generation device for transforming kinetic energy produced by motions of a user into electric energy and for causing the electric energy to output from a magnetic coil as an electric charging energy; a secondary power source charged by said electric charging energy; a timepiece circuit driven by a charged energy from said secondary power source to output motor drive pulses; and a drive motor including a drive coil and a drive rotor rotatably driven when the drive coil is energized by said motor drive pulses. This analog indication type electronic timepiece further includes an anti-overcharging device forming a bypass circuit for causing said electric charging energy to bypass relative to said secondary power source when the voltage at said secondary power source reaches a predetermined level, thereby preventing the overcharging to the secondary power source; and a current limiting device for forcedly limiting the bypass current flowing through said bypass circuit when the motor drive pulses are being output from said timepiece circuit, whereby an accurate analog time indication can be made while preventing a malfunction in the drive motor during the anti-overcharging operation to the secondary power source.

Growing community of inventors

Okaya, Japan

Tatsuo Hara