| US 7,494,259 B2 | ||
| Lighting unit | ||
| Keiji Hayashi, Kawasaki (Japan); Takeshi Gotoh, Kawasaki (Japan); Toshihiro Suzuki, Kawasaki (Japan); Hisashi Yamaguchi, Kawasaki (Japan); Tetsuya Kobayashi, Kawasaki (Japan); Tetsuya Hamada, Kawasaki (Japan); and Mari Sugawara, Kawasaki (Japan) | ||
| Assigned to Sharp Kabushiki Kaisha, Osaka (Japan) | ||
| Filed on Oct. 01, 2003, as Appl. No. 10/676,315. | ||
| Application 10/676315 is a division of application No. 09/821976, filed on Mar. 30, 2001, granted, now 6,655,810. | ||
| Claims priority of application No. 2000-187026 (JP), filed on Jun. 21, 2000; and application No. 2000-378352 (JP), filed on Dec. 13, 2000. | ||
| Prior Publication US 2005/0276072 A1, Dec. 15, 2005 | ||
| Int. Cl. F21V 8/00 (2006.01) | ||
| U.S. Cl. 362—609 [362/610; 362/614; 362/616] | 7 Claims |
| 1. A lighting unit comprising:
a light-reflecting reflector;
a plurality of cold-cathode tubes disposed inside the reflector; and
an optical waveguide connected with an open end of the reflector to guide the light emitted by the cold-cathode tubes;
wherein the reflector has a reflective surface that reflects the light having been emitted by the cold-cathode tubes in the
direction nearly perpendicular to the wall of each tube, and only in a direction in which the light thus reflected does not
re-enter the cold-cathode tubes; and
further wherein the reflective surface includes at least three adjacent concaved curve segments, with each of the adjacent
concaved curve segments having a curvature center and a constant radius, with the constant radius of at least one of the concaved
curve segments being different from the constant radius of at least one other concaved curve segment.
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