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. 10, 2015
Filed:
Mar. 13, 2013
Canon Kabushiki Kaisha, Tokyo, JP;
Takashi Fukuhara, Higashikurume, JP;
Canon Kabushiki Kaisha, , JP;
Abstract
A displacement measuring apparatus includes a light source configured to illuminate light, and a photodetector provided on a structure and configured to detect reflected light from a reflection portion of a scale that alternately and periodically includes a convex portion scattering the light from the light source and the reflection portion reflecting the light, the displacement measuring apparatus measures a relative displacement between the structure and the photodetector based on a detection result from the photodetector, a length of the reflection portion in a period direction of the scale is greater than a half of a sum of lengths of the convex portion and the reflection portion, and the reflection portion includes a curved concave portion that reflects and collects the light illuminated from the light source.