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:
Jun. 11, 1991
Filed:
Feb. 05, 1990
Mark Shechterman, Nes-Ziona, IL;
El-Op Electro-Optics Industries, Rehovot, IL;
Abstract
The invention relates to an infra-red objective zoom system providing a high performance over a range of magnifications of from about 0.5 to about 8 times with a correction for temperature changes in a wide range it comprises only five optical groups of a total of seven lense groups (termed herein A to D). These are arranged in the sequence of A, a front singlet lens of positive power with a diameter larger than that of the other lenses abberation, B a negative optical element consisting of lenses B' and B'; B' being a negative lens having a dispersive factor larger than that of the other lenses, resulting in achromatization of the system; B' is a negative lens. Both negative lenses B' and B' have under-corrected spherical abberations, C being a positive lens, D being a positive auxiliary lens, being at a fixed distance respective lens A; E being a movable collimator of positive optical power, lenses B, C and E being movable respective fixed lenses A and D, said lenses transmitting in the 3.mu. to 12.mu. range. Lenses A to D define an objective and E a collimator (eyepiece). The movements of lenses B, C and E are according to a predetermined program which takes into consideration changes of temperature of the system.