| 摘要 |
PURPOSE:To detect a speed in a wide range with a simple constitution, by constituting a detector with an incidence lens system of an optical image, a polygon mirror, and an optical grating system and moving the optical image independently of the still or moving state of an object to be measured. CONSTITUTION:The first and the second optical grating systems 30 and 40 are arranged on upper and lower arcs of an incidence lens system 10 which face an object 50 to be measured and a polygol mirror 21, which is always rotated by a motor 23, respectively, and light receiving faces 32 and 42 of these systems 30 and 40 are allowed to face the reflective face of the mirror 21, and respective gratings are inclined at + or -45 deg. to a center 22 of the mirror 21 symmetrically. The incident optical image is focused on light receiving faces 32 and 34 while being moved in the rotation direction of the mirror; and in this case, the optical image is moved on light receiving faces 32 and 42 as a new speed vector of the sum of the speed vector due to rotation of the mirror 21 and the speed vector of the object 50. |
