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:
Apr. 03, 2018
Filed:
Mar. 06, 2017
Lc-tec Displays Ab, Borlänge, SE;
Jesper Osterman, Falun, SE;
Terry J. Scheffer, Hilo, HI (US);
LC-TEC Displays AB, Borlange, SE;
Abstract
A variable transmission filter combines in optical series first and second guest-host liquid crystal devices arranged such that one of them is rotated 180° about its normal axis with respect to the other one. The reverse arrangement of the liquid crystal directors of the first and second guest-host liquid crystal devices improves the viewing angle range of the variable transmission filter but, without compensation, introduces a diminution of contrast ratio. A polarization state-changing device positioned between the first and second guest-host liquid crystal devices changes the polarization states of light exiting the first guest-host_liquid crystal device such that transmittance of light in first and second orthogonal polarization states incident on the first guest-host liquid crystal device responds to electric fields applied to the first and second liquid crystal devices and thereby counteracts the diminution of contrast ratio while maintaining the improved viewing angle range.