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:
Dec. 08, 1992
Filed:
Jun. 11, 1991
Keiji Matsui, Niwa, JP;
Atsushi Ieki, Niwa, JP;
Okuma Corp., Aichi, JP;
Abstract
A parallel light ray measuring apparatus invention measures the parallelism of a light beam by: receiving a light beam which has passed through two gratings having the same grating period by means of at least two photoelectric converting elements, and by detecting the light intensity obtained from those aforementioned photoelectric converting elements and the phase difference between the periodic signals obtained when either of the gratings is moved, using the at least photoelectric converting elements. Further, the parallel light ray measuring apparatus includes: a first grating; a second grating having the same grating period as that of the first grating, and being disposed such that the grating lines of the second grating are in parallel with those of the first grating; a light pick-up screen for receiving a light beam which has passed through both gratings, whereby the light intensity distribution appearing on the light pick-up screen is detected so as to measure the parallelism of the light beam.