| 摘要 |
PURPOSE:To know an absolute position, etc. by a simple structure, and to raise a resolution by constituting an absolute value code of a code of each train in a prescribed circumferential angle of a code disk having plural concentrical code trains, reading it, and sending it out successively as a detecting signal. CONSTITUTION:Codes of each train of each absolute value code 380-38n are constituted of 2-bit shown by either existence or absence of a slit 39, respectively, a code train 371 of the outside circumferential side corresponds to one light emitting element and photodetector 331, 341, and a code train 372 of the inside circumferential side corresponds to the other light emitting element and photodetector 332, 342. A code disk 31 is rotated, for instance, in the direction as indicated with an arrow (a) by a revolving shaft 32, and also a light from the light emitting elements 331, 332 is photodetected by the photodetectors 341, 342. Since the absolute value codes 381-3815 are constituted of two concentrical code trains 371, 372, an absolute value is derived by only using a pair of light emitting elements 331, 332 and photodetectors 341, 342, also a rotating direction, etc. can be discriminated, and this rotary encoder can cope with conversion to a small size, and can be manufactured at a low cost. |
