Scanning type laser displacement gauge

TLDR: In this paper, the authors measured the shapes of various kinds including slant faces different in angle of inclination stably by radiating plural lasre lights at different angles of incidence by use of a parabolic mirror and receiving reflected light in the vertical direction and in the direction of regular reflection to selectively measure the height and quantity of light.

Abstract: PURPOSE:To measure the shapes of various kinds including slant faces different in angle of inclination stably by radiating plural lasre lights at different angles of incidence by use of a parabolic mirror, and receiving reflected light in the vertical direction and in the direction of regular reflection to selectively measure the height and the quantity of light CONSTITUTION:Lasers 3, 4, 5 of different wavelengths are composed on the same optical axis through a first dichroic mirror 6 The laser light is scanned 7 in the horizontal direction, the scanned laser light is converged to a required beam diameter by the measuring surface of a measurement stage 1, further dispersed by a second dichroic mirror 10 through a ftheta lens 8 for keeping the scanning speed constant and a mirror 9 for reflecting in the vertical direction, and further reflected by a parabolic mirror 11 to enter the stage 1 at different angles of incidence The reflected light in the direction of regular reflection on a flat surface is received by a photo detecting element 14 through a converging lens 12 and a filter 13 The reflected light in the vertical direction is dispersed by a third dichroic mirror 16 through a second converging lens 15 and received by photoelectric transfer elements, 17, 18 and 19