| 摘要 |
PURPOSE:To remove the effect due to uneven phase with respect to the angle of radiation by moving a reflecting member into and out of the optical path between a light emitting section and an object lens to enable the use of light which is almost the same in the range of radiation angle as correcting light. CONSTITUTION:When a measuring light is selected, a radiation light from a light emitting section 1 passes through a through hole 5 of a shutter 2, then, reflected on the reflecting surface 6a of a light beam splitter 6 and radiated as parallel flux passing through an object lens 7. The radiation light is reflected with a corner cube 8 at the measuring point to be distance measuring information via a light receiving section 9. When a correcting light is selected, a radiation light from the light emitting section 1 passes through the through hole 5, a light with the range of angle of radiation almost the same as the measuring light containing the optical axis of the light emitting section 1 is reflected from a reflecting member 4 to form a parallel flux with a condenser lens 10 for the correcting light. Then, it is focused with a condenser lens 11 via reflecting members 12 and 13 and enters the light receiving section 9 to offer correcting information for measuring errors based on a phase deviation between the optical path length and an electronic circuit section in the apparatus. |
