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. 06, 2007
Filed:
Feb. 14, 2006
Kai Chang LU, Birmingham, GB;
Patricia M. Hughes, Round Rock, TX (US);
Kai Chang Lu, Birmingham, GB;
Patricia M. Hughes, Round Rock, TX (US);
3M Innovative Properties Company, St. Paul, MN (US);
Abstract
A wide angle projection lens includes, in sequential order from an image side, a first lens group of negative refractive power, the first lens group having at least one aspheric surface, a second lens group, and a third lens group of positive refractive power. For the wide angle projection lens, the following Conditions (1) to (4) are satisfied: |F/F|≧4.5 (Condition (1)); 2.5≦|F/F|≦6.0 (Condition (2)); 3.8≦|F/F|≦5.0 (Condition (3)); and 0.8≦BFL/F≦1.4 (Condition (4)). An optical engine, including the wide angle projection lens, can be implemented in a projection display device.