| 摘要 |
PURPOSE:To obtain high resolution and high accuracy in the detection of the number of rotations, by a method wherein laser beams are projected against a film, whose coefficient of reflection is changed by the projection of the laser beams, to write bits for detecting the position of rotation as well as the number of rotation. CONSTITUTION:A rotor 11 is provided with a driving magnet unit 13 and a signal recording unit 14 for controlling the position of rotation as well as the number of rotations. A stator 12 is provided with a driving coil 15 and a signal detector 16 for detecting a signal recorded in the signal recording unit 14. The signal recording unit 14 is formed by a method wherein laser beams are projected against a film, whose coefficient of reflection is changed by projecting the laser beams, to write bits for detecting the position of rotation as well as the number of rotations. |
