Patent ID: 9316536
Filing Date: 2016-04-19
CPC Classification: G01B,G01J,G02B

Claim Text:
1. A spatial frequency reproducing apparatus, comprising: a light source emitting a coherent light; a first means for modulating the light emitted from the light source into two lights which have frequencies different from each other and are irradiated separately adjacent to each other; a second means for one-dimensionally or two-dimensionally scanning the two lights; a third means for irradiating an object under measurement with the two lights which are scanned; a fourth means for receiving and converting into an electrical signal at least two or more divided lights from the object under measurement with a boundary line being interposed therebetween in a direction substantially perpendicular to the direction in which the two lights are separated; a fifth means for amplifying respective electrical signals photoelectrically converted by the fourth means with respect to respective areas with the boundary line being interposed therebetween while varying a degree of amplification according to frequencies of the electrical signals and generating a difference signal or a summation signal of the amplified signals; and a sixth means for obtaining a phase difference or an intensity difference of the difference signal or the summation signal to obtain a measurement value.