| US 7,573,642 B2 | ||
| System for collimating backlight | ||
| Neil D. Lubart, Austin, Tex. (US); Timothy J. Wojciechowski, Westlake, Ohio (US); and Thomas E. Lash, Shaker Heights, Ohio (US) | ||
| Assigned to Brilliant Film LLC, Cleveland, Ohio (US) | ||
| Filed on Feb. 26, 2008, as Appl. No. 12/37,262. | ||
| Application 12/037262 is a division of application No. 11/194360, filed on Aug. 01, 2005, granted, now 7,345,824. | ||
| Application 11/194360 is a continuation in part of application No. 10/108296, filed on Mar. 26, 2002, abandoned. | ||
| Application 10/108296 is a continuation in part of application No. 10/688785, filed on Oct. 17, 2003, granted, now 7,428,367. | ||
| Claims priority of provisional application 60/600272, filed on Aug. 10, 2004. | ||
| Prior Publication US 2008/0144182 A1, Jun. 19, 2008 | ||
| Int. Cl. G02B 27/10 (2006.01); G02B 27/30 (2006.01) | ||
| U.S. Cl. 359—641 [359/619] | 31 Claims |
| 1. A collimating device for use in a system having a backlight, the collimating device comprising:
an immersing layer;
a reflecting layer; and
an optical element layer formed from a plurality of three-dimensional, optical elements,
each optical element having a light input end and a light output end, each optical element being tapered towards the backlight
such that the light input end has a horizontal plane cross-sectional area that is less than that of the light output end,
wherein each optical element has a vertical plane cross-section that includes at least one curved section that is an approximation
of a compound parabolic concentrator and includes at least one linear section, such that uncollimated light entering the light
input end of the optical element from multiple angles emerges from the light output end of the optical end as a substantially
uniform sheet, and wherein the curved section is defined by an arc of a circle, and a slope of the curved section matches
a slope of the at least one linear section at the intersection point of the curved section and the at least one linear section,
and
wherein the reflecting layer has apertures therein which correspond to the position and shape of the light input ends of the
optical elements.
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