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. 05, 1994
Filed:
Apr. 21, 1993
Jurgen Zobel, Bretten, DE;
Richard Wolf GmbH, Knittlingen, DE;
Abstract
The endoscope optical system has an objective with an object-side negative lens cluster, the constructional design of which should minimise or exclude image scale defects, such as distortion and field curvature. The object-side negative lens cluster comprises two menisci each having negative refractive power. The individual defects of distortion occurring at the surfaces are reduced as a result of the meniscus-like design, and a flattened image field, that is prevention of field curvature, is achieved as a result of splitting the lens cluster into two menisci. The object-side meniscus may be designed as a single lens or as a cemented component comprising an outer lens and an inner lens. Since the distortion defect at the cement surface has a negative sign, the defects are thus partially compensated at the outer surfaces of the meniscus.