| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical encoder more excelling in an S/N ratio. SOLUTION: A lens 724 converts light emitted from an LED 721 into upward parallel light. A first aperture 722 is disposed so that only direct light from a light emitter 7211 of the LED 721 passes therethrough. A second aperture 723 is disposed so that only light components reach the lens 724, the light components effectively converted into parallel light in the lens 724 out of the direct light from the light emitter 7211 of the LED 721. Four square-shaped through holes 71 are provided in a parallel light mask 725. Out of the parallel light with the light components converted thereinto by the lens 724, only light components going toward the light receiving faces of four photodiodes in a photodiode array 732 pass therethrough. The parallel light emitted from a light sender 72 passes through a first slit 5, then passes through a second slit 731, and reaches the receiving faces of the four photodiodes in the photodiode array 732. COPYRIGHT: (C)2011,JPO&INPIT
|
