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:
Nov. 20, 1990
Filed:
Dec. 23, 1988
Yasuyuki Koyagi, Tenjinkitamachi, JP;
Abstract
A method of and an apparatus for optically detecting the position of an object having a surface including first and second reflecting regions each having a different reflectance coefficient. First a ratio of reflectance of the first reflecting region to that of the second reflecting region is obtained. Incident optical beams are projected onto the measured surface of the object, and first and second reflected optical beams reflected by the first and second reflecting regions of the measured surface are received at a photoelectric conversion element to obtain first and second light receiving signals, respectively. Thereafter, the second light receiving signal is multiplied by the reflectance ratio to produce a correction light receiving signal. Further, the central position of the reflected optical beams is obtained on the basis of the first light receiving signal and the correction light receiving signal. Thus, the central position of the reflected optical beams can be obtained with very high accuracy.