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. 16, 2016
Filed:
May. 13, 2013
Hsienhui Cheng, Kent, OH (US);
Achintya Bhowmik, Santa Clara, CA (US);
Philip J. Bos, Hudson, OH (US);
Hsienhui Cheng, Kent, OH (US);
Achintya Bhowmik, Santa Clara, CA (US);
Philip J. Bos, Hudson, OH (US);
Kent State University, Kent, OH (US);
Abstract
A phase retarder comprises first and second π-cells or other tunable birefringent devices arranged optically in series. The phase retardation value of the phase retarder is a difference between the phase retardation values of the first and second π-cells. Driving circuitry drives the phase retarder to generate a target phase retardation value by: (1) prior to a relaxation period, biasing the π-cells to produce the target phase retardation value; (2) during the relaxation period, biasing the first π-cell at a constant bias value; and (3) during the relaxation period, lowering the bias value of the second π-cell continuously or stepwise to maintain the target phase retardation value for the phase retarder throughout the relaxation period. In some embodiments the operation (2) comprises applying zero bias to the first π-cell throughout the relaxation period. In some embodiments the operation (1) comprises applying a maximum operational bias to the second π-cell.