| 摘要 |
PURPOSE:To reduce the number of components and the cost and to attain compact mounting space by providing lots of slits for light transmission or projections for forming magnetic path at an equal interval to a disc except required angle ranges and detecting discontinuous part of a signal string from each signal period so as to generate an original signal. CONSTITUTION:A rotary shaft 2 is inserted and fixed incorporatedly to a disc 1. Lots of slits 3 are formed on the same circumference of the disc 1 except a prescribed center angle range theta. In this case, the prescribed angle range thetawithout the slits 3 is taken nearly 2-3 slits and the range theta is provided at one part of the disc 1. Then a photodetector 4 and a light emitting source are opposed in a matching way while clipping the disc 1, the light from the light emitting source is intermitted by the rotation of the disc 1, the light is detected by the photodetector 4 to output an electric pulse signal.
|
