VELOCIMETER, DISPLACEMENT METER, VIBROMETER AND ELECTRONIC DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a velocimeter which can be made compact, realize low-power consumption operations, and precisely detect the moving speed and moving direction of an object to be measured.;SOLUTION: A first luminous flux 7, emitted from the front end face of a semiconductor laser 1, is brought to enter a diffraction grating 3a, and a second luminous flux 8, emitted from the rear end face of the semiconductor laser 1, is brought to enter a diffraction grating 3b. A detection point 14a is made up of both positive first-order diffraction light 7a generated by the diffraction grating 3a and positive first-order diffraction light 8a generated by the diffraction grating 3b, and a detection point 14b is made up by both negative first-order diffraction light 7b generated by the diffraction grating 3a and the negative first-order diffraction light 8b generated by the diffraction grating 3b. Scattered light portions from the detection points 14a, 14b are received by photodiodes 2a, 2b. Then, the amount of frequency shift between the scattered light portions is computed by a signal processing circuit section 10, based on outputs Sa, Sb of the photodiodes 2a, 2b.;COPYRIGHT: (C)2005,JPO&NCIPI