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. 17, 1976
Filed:
Nov. 20, 1974
Wallace Louis Minto, Sarasota, FL (US);
Sarasota Instruments Inc., Sarasota, FL (US);
Abstract
An apparatus for measuring the index of refraction of a specimen includes a stage plate having a small exposure opening behind which are located a point source infra-red light emitting diode and a photoresistor. A first lens focusses the LED point source along a first optical axis at the exposure opening on the plane of the specimen receiving face of the stage plate defining a sensing area and a second lens focusses the image on the sensing area along a second optical axis onto the photoresistor. The optical axes form equal angles to the perpendicular to the exposure plane at the center of the sensing area. The light emitting diode and the photoresistor are connected through a common normally open switch to a battery.