| 摘要 |
PROBLEM TO BE SOLVED: To provide a light-spot diameter measuring device in which measuring time is shortened and automation and accuracy are improved in measuring a scanning optical system. SOLUTION: This device comprises and optical sensor 6 for measurement to receive a laser luminous flux as a light spot capable of scanning by he rotary polygon mirror 4 of a scanning optical system 1, optical sensor displacement means 7 and 12 to displace the light receiving surface 6a of the optical sensor 6 to a desired point of measurement with respect to a surface to be scanned, a light spot location displacement means comprised by rotation-freely connecting the rotary polygon mirror 4 to a stepping motor 9 by a clamp-shaped member 16 capable of sandwiching two corner parts or more of the rotary polygon mirror 4, and a control means 11 to control the optical sensor displacement means 7 and 12 and the light spot location displacement means on the basis of a light reception signal of the optical sensor 6 and to compute the diameter of the light spot, etc. |
