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:
Oct. 23, 1979
Filed:
Jun. 29, 1977
Applicant:
Inventor:
James G Baker, Winchester, MA (US);
Assignee:
Polaroid Corporation, Cambridge, MA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
350212 ; 350189 ; 350232 ;
Abstract
A compact substantially afocal lens comprising two components each including two elements adapted for use as a magnifying attachment for an objective with an internal stop. Compactness in an afocal lens of good performance is obtained by the use of a strongly curved first surface followed by other strongly curved surfaces, by the choice of alternating high and low indices of refraction for the successive negative and positive elements, respectively, and by correcting the lens less well for longitudinal color and distortion than for the other aberrations.