Light collimating device

• US 7,345,824 B2
• Filed: 08/01/2005
• Issued: 03/18/2008
• Est. Priority Date: 03/26/2002
• Status: Expired due to Fees

• Current Assignee: Rambus Delaware LLC (Rambus Inc.)
• Original Assignee: Trinium Technologies
• Inventors: Wojciechowski, Timothy J., Lubart, Neil D., Lash, Thomas E.
• Primary Examiner(s): Harrington; Alicia M
• Application Number:
  US11/194,360
• Publication Number:
  US 20050259198A1
• Time in Patent Office: 960 Days
• Field of Search: 359/641, 359/712, 359/708, 359/718, 362/559, 362/268, 362/335, 362/338, 349/95, 349/61, 349/62
• US Class Current: 359/641
• CPC Class Codes: G02B 17/002 Arrays of reflective systems
• CPC Class Codes: G02B 27/0972 Prisms prisms per se G02B5/04
• CPC Class Codes: G02B 27/0983 being curved
• CPC Class Codes: G02B 27/30 Collimators
• CPC Class Codes: G02F 1/133524 Light-guides, e.g. fibre-optic bundles, louvered or jalousie light-guides
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/133607 the light controlling member including light directing or refracting elements, e.g. prisms or lenses

Abstract

A collimating device and a transflector for use in a system having a backlight is disclosed herein. In one embodiment of the application, the collimating device and the transflector each include an immersing layer, a reflecting layer, and an optical element layer formed from a plurality of three-dimensional, optical elements. Each optical element is tapered such that a small area end has a horizontal plane cross-sectional area that is less than that of a wide area end. The optical elements of the collimating device are tapered towards the backlight and the optical elements of the transflector are tapered away from the backlight. The reflecting layer has apertures which correspond to the position and shape of the light input ends of the optical elements.

Claims

1. An optical layer having a light input side and a light output side, the optical layer comprising:

a plurality of three-dimensional, light collimating elements,

wherein each optical element has a light input end, a light output end, and a polygonal horizontal plane cross-section, and

wherein each optical element is tapered, such that a vertical plane cross-section of the optical element 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 element as a substantially uniform sheet, 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.

2. A single, discrete element in an optical element layer for transmitting light, the single, discrete element comprising:

a light input end having a polygonal shape;

a light output end having a polygonal shape;

a plurality of sides, tapered from the light output end to the light input end and configured to focus light such that substantially all light entering the light input end emerges fully collimated from the light output end, wherein each of the plurality of sides include at least one region that is a circular approximation of a compound parabolic concentrator and at least a first linear section and a second linear section, wherein the first linear section is adjacent the light output end, the second linear section is adjacent the light input end, and the circular approximation of a compound parabolic concentrator is located between the first and second linear sections.

3. An optical element layer for transmitting light, comprising:

a plurality of light collimating elements, each having

a light input end,

a light output end, and

a plurality of sides, tapered from the light output end to the light input end, each side including at least one section defined by an arc of a circle and at least one linear section, wherein the at least one section defined by an arc of a circle matches the slope of the at least one linear section at an intersection point of the at least one section defined by an arc of a circle and the at least one linear section, wherein each of the plurality of light collimating elements is configured to fully collimate light entering through the light input end and emerging from the light output end.