Patent ID: 7782718
Filing Date: 2010-08-24
Classification: G04C,G04G,G04R

Abstract:
1. An electronic watch including: (a) analogue display means formed of at least one hand driven by a stepping motor, wherein said stepping motor includes a magnetised rotor including at least two stable magnetic positions relative to a stator, and a defined number of intermediate positions corresponding to a number of microsteps of said stepping motor over a complete rotation of said magnetised rotor, wherein said number of microsteps is higher in number than the number of stable magnetic positions; (b) at least one time base for providing first time data to means for controlling and driving said stepping motor; (c) a main power source; (d) means for detecting a lack of sufficient power from said main power source; and (e) non-volatile storage means, wherein the electronic watch operates in a normal operation mode when said main power source provides sufficient power and the electronic watch enters into a low power mode upon detection of the lack of sufficient power, wherein in the low power mode said stepping motor is stopped, and wherein when the electronic watch enters into the low power mode, the electronic watch stores the first time data and a first intermediate position of the rotor in the non-volatile storage means, and when the electronic watch is again sufficiently supplied with power from the main power source, the electronic watch again enters into the normal operation mode and the at least one hand is again synchronized with the first time data by taking into account the first intermediate position stored in said non-volatile storage means and a first stable magnetic position in which said rotor had gone when the electronic watch last entered into the low power mode.