| 摘要 |
PURPOSE:To enable the measurement of a distance within a shot time, by measuring the average particles size of speckles from the intensity distribution of said speckles. CONSTITUTION:When laser beam 3 is allowed to irradiate an objective body 1 from laser 2, the laser beam 3 diffused on the surface of the objective body 1 forms a speckle pattern. Said diffused laser beam is received by a unidimensional beam detection sensor 101 and accumulated as charge quantity proportional to the intensity of beam. Accumulated charge is successively read by the signal of a drive circuit 102 and outputted as the electric signal corresponding to beam intensity distribution from the circuit 102. In an average particle size operation circuit constituted of differentiators 103, 105, effective value operators 104, 106 and a divider 107, an average particle size is calculated in a real time necessary for measurement. Because the average particle size varies timewise, averaging is performed by an amplitude/frequency converter 108 and a counter 109. Because the average particle size is proportional to a measured distance, the conversion result to the distance is displayed by a display part 110. The greater part of the operation circuit is constituted of an electronic circuit and the miniaturization of the apparatus is enabled and the measurement of distance in a real time necessary for measurement is enabled. |
