Patent · US Expired

Single lens having one spherical and one aspherical refractive surface

US4415238A · kind A · utility

12Cited by

1References

1Claims

0Family size

Assignee

U.S. Philips Corporation · US

Inventors

Josephus J. M. Braat · Delft, NL
Jan Haisma · Eindhoven, NL
Gijsbert Prast · Eindhoven, NL

Key dates

Filing date	Oct 2, 1981
Grant date	Nov 15, 1983
Priority date	—
Expiry date	Oct 2, 2001

Classification

Technology area (CPC G)Physics
CPC primaryG02B3/04
WIPO fieldOptics
WIPO sectorInstruments

Abstract

A lens having a spherical surface and an aspherical surface curved relative to each other to minimize coma for a large diffraction-limited field and a large numerical aperture.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.