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. 20, 2004
Filed:
Dec. 28, 2001
Jack R. Kelly, Stow, OH (US);
Haiji J. Yuan, Cupertino, CA (US);
Qingyu (Tom) Li, Cupertino, CA (US);
CoAdna Photonics, Inc., San Jose, CA (US);
Abstract
An achromatic half wave plate includes a first twisted nematic liquid crystal layer, a second twisted nematic liquid crystal layer, and a uniaxial half wave plate between the first twisted nematic liquid crystal layer and the second twisted nematic liquid crystal layer. In one embodiment the first twisted nematic liquid crystal layer and the second twisted nematic liquid crystal layer have an identical twist angle of 135 degrees. The optic axis at the entrance of the first twisted nematic liquid crystal layer is substantially orthogonal to the optic axis at the exit of the second twisted nematic liquid crystal layer.