LASER SPECKLE SPEEDOMETER

摘要

PURPOSE:To obtain a speedometer capable of performing measurement under various conditions in a wide measurable range, by utilizing the mutual relation present between a speckle pattern obtained by irradiating an object with laser beam and the moving speed of the object. CONSTITUTION:Coherent beam from a laser diode 10 propagates through an optical fiber 18 and irradiates the surface of an object to be measured during movement from the emitting terminal surface of the optical fiber 18 directed to the object 15 to be measured. The diffused reflected beam generated from the surface of the object 15 to be measured forms a speckle pattern and a part thereof is incident to an optical fiber 19 to be guided to a photodiode 16. The beam intensity distribution of the speckle pattern is converted to an electric signal by the photodiode 16 and inputted to a signal processing part 17. This signal processing part 17 calculates a speed from the mutual relation of the above mentioned beam intensity distribution and the speed of the object to be measured.