Patent ID: 7973940
Filing Date: 2011-07-05
Classification: G01B

Abstract:
1. An optical object measurement apparatus in which a predetermined area of an object to be measured is irradiated with a light beam from a light source, and optical interference is used to detect light reflected from the object in order to derive therefrom tomographic information of the object, the apparatus comprising: a light source for generating a low-coherent light beam; pinhole means disposed in a plane through which the light beam passes for sweeping the light beam from the light source; a beam splitting element for splitting the light beam that has passed through the pinhole means into a probe light beam directed toward the object and a reference light beam directed toward a reference optical path; light modulating means for modulating the reference light beam such that the phase thereof periodically shifts in the reference optical path; two-dimensional image-capturing means for detecting an interference light beam that is produced by interference between the probe light beam from the object that has been guided via the beam splitting element and the reference light beam that has been modulated by the light modulating means; and signal processing means for processing a video signal from the two-dimensional image-capturing means to extract phase information of the interference light beam dependent on light modulation by the light modulation means and derive therefrom reflection intensity information of an interior of the object, wherein the phase shifting of the reference light beam performed by the light modulating means is periodically performed in accordance with the frame rate of the two-dimensional image-capturing means.