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:
Jul. 09, 1991
Filed:
Nov. 29, 1989
Applicant:
Inventors:
Assignee:
Akzo N.V., Arnhem, NL;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01J / ; G01D / ; G02F / ;
U.S. Cl.
CPC ...
356243 ; 2502521 ; 350330 ;
Abstract
A device and method for optical calibration of an optical instrument that measures optical characteristics along an optical path. A controllable shutter having electrically alterable optical characteristics is placed across the optical path of the instrument. An electrical control is connected to the shutter for selectively providing a variable voltage to the shutter to electrically alter optical characteristics of the shutter in a controlled manner so that the optical characteristics of the shutter correspond to selected optical characteristics.