Abstract: A self-winding watch includes a movement connected to a winding device of a barrel spring including an oscillating weight pivoting around an axis A, a reduction wheel train cooperating with the oscillating weight to transmit the torque to the barrel, a storage unit for electrical energy, a photovoltaic cell arranged to receive the ambient light and charge the electrical energy storage unit, a control circuit connected to the terminals of the electrical energy storage unit and a driver connected to the circuit and coupled to the oscillating weight to displace it. The electrical energy storage unit, the control circuit an d the driver are integrated to the oscillating weight.

Abstract: A timing device utilizes hybrid power to drive a movement of the timing device, the hybrid power supply functioning as an auxiliary unit to deliver power to an electro-magnetically driving unit through an automatic control unit manipulated by a mechanical energy storage status detection unit to produce mechanical energy in time to prevent the movement from stopping; a main spring barrel or a potential difference weight of the kinetic energy storage unit being driven to further drive a wheel chain of the timing device and automatically suspend driving upon the completion of winding the wheel train.

Abstract: 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.

Abstract: A timepiece includes a hairspring for storing the energy provided by a step motor driving circuit and a rotor immersed in a viscous fluid controls the energy released by the hairspring to provide a constant driving force for turning the display hands of the timepiece. A frequency divider circuit counts the number of clock signals produced by an oscillator. During time correction when the hands are prevented from being driven by the energy stored in the hairspring the frequency divider retains at least a portion of the count. A recoil torque provided by the hairspring and a load torque provided by the rotor are substantially balanced at all times including immediately after the time correction activities. Time delay especially immediately following the time correction activities is avoided.

Abstract: A barrel spring winding device comprises a solar cell (3) arranged to receive ambient light, a capacitor (4) connected to the terminals of the cell, a stepping motor (6) and a control circuit (5). The input of the circuit is connected to the terminals of the capacitor and its output to the terminals of the motor. The rotor of the motor is operatively connected to wind a barrel spring, for example of a watch. The cell (3) charges the capacitor (4) and when the voltage thereof, measured by a differential amplifier (23), reaches a reference voltage (V.sub.r), the capacitor is connected to the terminals of the motor by a switching transistor (27). Discharge of the capacitor supplies to the motor a drive pulse whose duration is determined by a one-shot flip-flop (25). After the pulse, the capacitor is once again charged by the cell. To prevent the motor from receiving a drive pulse before it has stopped, i.e.