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. 02, 1993
Filed:
Oct. 30, 1991
William F Stephens, Badminton, GB;
Stephen E Lummes, Stroud, GB;
Renishaw plc, Gloucestershire, GB;
Abstract
An opto-electronic scale reading apparatus comprises a light source (20) which projects light via an index grating (22) onto a reflective scale (10). Light is reflected from the scale (10), passes through an auxiliary grating (36) and is incident upon an analyser grating (28), at which a plurality of periodic light patterns are formed. Light from the light source (20) travels initially parallel to the scale plane, and is subsequently deflected through 90.degree. by a beam splitter cube (26); the light is thus incident upon and reflected and off the scale (10) at 90.degree. to the scale plane. This arrangement enables large movements of the readhead in a direction perpendicular to the scale.