Patent Number: 6,252,828

Title: Electronically controlled mechanical timepiece and control method therefor

Abstract: An electronically controlled mechanical timepiece includes: a voltage-controlled oscillator (25) including a generator that uses a rotor (12) driven by a spring (1a) to rotate, and a brake circuit (23) for controlling the rotation cycle of the generator (20); and a rotation control means (50) for controlling the rotation cycle of (50) includes a phase-comparison circuit (54) for comparing the phases of rectangular-wave pulses fr output from a VCO (25) and time standard signal fs, and a brake control circuit (56) for inputting, based on an output from the phase-comparison circuit (54), a signal for controlling the brake circuit (23) to a voltage-controlled oscillator (25). By providing the VCO (25) and the phase-comparison circuit (54), PLL control is realized to enable a rapidly responsive system.

Inventors: Shinkawa; Osamu (Suwa, JP), Koike; Kunio (Matsumoto, JP)

Assignee: Seiko Epson Corporation

International Classification: G04C 10/00 (20060101); G04C 11/00 (20060101); H02P 3/00 (20060101); H02P 3/04 (20060101); G04B 001/00 ()

Expiration Date: 06/26/2018