| 摘要 |
PURPOSE:To obtain a miniaturized device and high resolution, by detecting the change of the intensity of reflected light or transmitted light due to the irregular pattern of a rotary disk. CONSTITUTION:A light projecting/receiving part 20 is constituted of a light emitting element 21, a lens system 22, a beam splitter 23, and a light receiving element 25. The light emitting element 21 is, for example, a laser diode, and outputted light from the element is condensed on the irregular pattern 2 of the rotary disk 11, and the reflected light from the disk is condensed on the light re ceiving element 25 through the lens system 22 and the beam splitter 23. And by waveform-arranging an electrical signal outputted from the light receiving element 25, a series of pulses can be obtained according to the rotation of the rotary disk 11.
|
