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:
May. 13, 2003
Filed:
Apr. 12, 2001
Chungte W. Chen, Irvine, CA (US);
Ronald G. Hegg, Vista, CA (US);
William B. King, Rancho Palos Verdes, CA (US);
Raytheon Company, Lexington, MA (US);
Abstract
An external pupil lens system ( ) with an entrance pupil distance at least three times that of the effective focal length. The lens system is comprised of several conventional lenses and a diffractive optical element (DOE) for secondary chromatic aberration correction. In the illustrative embodiment, the system includes an entrance pupil ( ), followed by a lens group ( ) containing two refractive elements for primary color correction. Next along the optical axis is lens group ( ), which contains two refractive elements for astigmatism and higher order coma correction, followed by lens group ( ), which contains one refractive element ( ) and one DOE ( ) for secondary color correction.