The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 27, 1990
Filed:
Feb. 07, 1989
Brother Kogyo Kabushiki Kaisha, Aichi, JP;
Abstract
An optical surface roughness measuring device for measuring roughness of a surface of a subject in a non-contacting manner. The apparatus includes a laser device for producing two linearly polarized laser beams which has mutually perpendicular polarization planes and different frequencies, and an optical device adapted to receive the two linearly polarized beams, converge one of the two laser beams so as to irradiate a first reading spot on the surface of the subject, convert the other of the two laser beams into parallel rays of light, and irradiate a second reading spot on the surface with the parallel rays of light of the other laser beam such that the second reading spot is aligned with the first reading spot and has a diameter sufficiently larger than that of the first reading spot. The surface roughness is measured based on a detected change in a beat frequency of the two laser beams reflected by the first and second reading spots. Alternatively, the two beams may be converged by a converging lens device at two spaced-apart points of the subject surface. In this case, an optical device includes an arrangement for establishing an angle of inclination between the directions of incidence of the two beams upon the converging lens device.