APPARATUS AND METHOD FOR MEASURING LIGHT QUANTITY

摘要

PROBLEM TO BE SOLVED: To simplify an optical system and correct the sensitivity drift or linearity of a light reception element. SOLUTION: A light quantity measuring apparatus is provided with an optical chopper 2 for interrupting incident signal light at prescribed periods while rotating; a reference light source 6 for irradiating reference light different from the signal light during the period in which the signal light is interrupted by the optical chopper 2; the light reception element 5 for receiving both the signal light and the reference light and measuring the light quantity of the signal light and the light quantity of the reference light; a correction operation circuit 13 for correcting the light quantity of the signal light on the basis of the light quantity of the reference light; and a correction value computation circuit 12 for computing a correction value by comparing a prescribed reference value with a light quantity value of the prescribed light. The correction operation circuit 13 corrects the light quantity of the signal light on the basis of the correction value. COPYRIGHT: (C)2007,JPO&INPIT