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. 10, 1979
Filed:
Aug. 24, 1977
Arthur H Firester, Skillman, NJ (US);
Macy E Heller, Trenton, NJ (US);
RCA Corporation, New York, NY (US);
Abstract
The light power not occluded during a repetitive, transverse knife-edge scanning of a focused spot is measured by a photodetector while an interferometer measures the displacement of the knife-edge during the scanning operation. The knife-edge is supported on a glass plate carried by the photodetector with a liquid medium being located between the glass plate and the light sensitive surface of the photodetector to enhance light reception by the photodetector. The differentiated output of the photodetector when displayed (e.g., by means of an oscilloscope) provides a graphic representation of the intensity profile of the spot which is dependent on the composite refractive index of the glass plate and the liquid medium. The output of the interferometer when displayed along with the intensity profile of the spot provides a known quantity with reference to which spot diameter as a function of the composite refractive index can be accurately determined to within 1/8 of a wavelength of the light provided for the measurements of the interferometer.