| 摘要 |
PROBLEM TO BE SOLVED: To provide a method capable of inexpensively and easily measuring the parallelism or angle of two surfaces facing each other with second-order accuracy without contact in real time and to provide an optical system used for the same. SOLUTION: A first surface to be measured 5 reflects light, and a second surface to be measured 6 reflects light. A mirror 8 is arranged perpendicularly to the second surface to be measured. A semi-transmissive member 10 is arranged in such a way as to form an angle of 45°to both of the second surface to be measured 6 and the mirror 8. An incident light beam 24 passes through the semi-transmissive member 10, is reflected by the mirror 8, and passes through the semi-transmissive member 10 again, and the angle of the return light to the incident direction is measured. The incident light beam 24 passes through the semi-transmissive member 10, is reflected by the mirror 8 to the direction of the second surface to be measured 6 by the semi-transmissive member 10, is reflected by the second surface to be measured 6, passes through the semi-transmissive member 10, is reflected by the first surface to be measured 5, and is reflected by the semi-transmissive member 10, and the angle of the return light to the incident direction is measured. The difference of angles of the surfaces to be measured 5 and 6 is measured on the basis of two acquired angles. COPYRIGHT: (C)2011,JPO&INPIT |
