| 摘要 |
PURPOSE:To obtain an economical and highly accurate dimension measuring apparatus by laser scanning, by using a spherical lens as one on the laser beam irradiating side and assembling a counting pulse correcting circuit in a processing circuit of light-receiving signal. CONSTITUTION:Laser generating apparatus 1, rotary polygonal mirror 3, spherical lens 4' and light-converging lens 5, and laser receiving apparatus 6 are arranged consecutively, and an output signal of this laser receiving apparatus 6 is fed into a signal processing circuit 20. Output signals of laser-light-receiving start sensor 11, laser-light-receiving end sensor 12 and clock-pulse generating apparatus 13 are fed in the signal processing circuit 20 also, and a multi-step binary counter 21 counts a number of pulses for the time of shielding by the specimen P of a laser beam. And, this counted value is corrected by a counted pulse correcting circuit 22 and the dimension of the specimen P is calculated. By this arrangement, high-accuracy measurement becomes available without resorting to an expensive Ftheta lens. |
