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:
Feb. 22, 2005
Filed:
Apr. 11, 2003
Applicant:
Stephen K. Eckhardt, White Bear Lake, MN (US);
Inventor:
Stephen K. Eckhardt, White Bear Lake, MN (US);
Assignee:
3M Innovative Properties Company, St. Paul, MN (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G03B021/14 ;
U.S. Cl.
CPC ...
Abstract
A projector illumination system includes a tunnel integrator incorporated with a field lens at its output end. One advantage of using the field lens is to form an image of the entrance end of the tunnel integrator at the secondary stop of the illumination system when combined with other relay and/or imager field lenses in the illumination system. This reduces vignetting, resulting in an increased uniformity of illumination, and increased light throughput.