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:
Aug. 04, 1987
Filed:
Jan. 22, 1985
Hiroshi Hanaoka, Kawasaki, JP;
Sadayuki Matsumiya, Kawasaki, JP;
Mitutoyo Mfg., Tokyo, JP;
Abstract
The disclosure depicts a measuring instrument incorporating in relatively movable portions thereof optical type displacement detecting devices. Each of the optical type displacement detecting devices includes: a main scale having fringes constituted by reflecting portions and non-reflecting portions, both of which are lined up alternately; an index scale having fringes constituted by light transmitting portions and non-light transmitting portions, both of which are lined up alternately; a light emitting element for irradiating an index scale and a main scale; and a light receiving element for receiving light reflected by the main scale through the index scale to emit an electric signal corresponding to a relative displacement value between the both scales. The main scale is provided thereon with a disturbance preventing layer which absorbs light transmitted through the non-reflecting portions of the main scale not to allow the light to be reflected to the index scale.