Patent ID: 7031230

Claim:
A timepiece, comprising: a mechanical energy source; an electric power generator driven by the mechanical energy source for outputting electrical energy, the electric power generator including a rotor; a rotation controller operated with the electrical energy generated by the electric power generator; hands driven under control of the rotation controller; and a starter for the electric power generator, the starter comprising: a startup member having an engaging portion capable of mechanically engaging with an engaged portion of a rotation target gear of the mechanical energy source, wherein the engaging portion is moved in response to operation of an external operating member to temporarily apply a rotating force to the rotation target gear, while the engaging portion is in engagement with the engaged portion, whereby the rotor is rotated at an increased speed upon start up of the electric power generator, wherein the rotating force temporarily applied to the rotation target gear in response to operation of the external operating member does not vary substantially regardless of the force applied to the external operating member, and is set to such a magnitude as to cause the rotor of the electric power generator to be started up at a reference speed.