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. 22, 2025
Filed:
Jan. 10, 2023
Reald Spark, Llc, Beverly Hills, CA (US);
Michael G. Robinson, Boulder, CO (US);
Graham J. Woodgate, Henley-on-Thames, GB;
Jonathan Harrold, Leamington Spa, GB;
Robert A. Ramsey, Boulder, CO (US);
RealD Spark, LLC, Boulder, CO (US);
Abstract
An imaging directional backlight apparatus including a waveguide, a light source array, for providing large area directed illumination from localized light sources. The waveguide may include a stepped structure, in which the steps may further include extraction features optically hidden to guided light, propagating in a first forward direction. Returning light propagating in a second backward direction may be refracted, diffracted, or reflected by the features to provide discrete illumination beams exiting from the top surface of the waveguide. Retarder stack arrangements are provided to reduce the display visibility to snoopers located in polar viewing regions of the display while achieving minimal reduction of head-on luminance. Further visibility of light reflections from automotive windscreens may be reduced.