Direct type back light
AssigneeLG Display Co., Ltd.
InventorsJong Hyun Choi, Dae San Lim
Life of this patent
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Abstract
A direct type back light includes a case holding a plurality of lamps. The lamps may be “U” shaped and have curves arranged at a centerline of the case to face each other with a gap there between. A reflecting plate is positioned below the plurality of lamps. A luminance control sheet is provided above the reflecting plate and below the lamps in several of, or all of, the gaps. The luminance control sheet may have a lower reflectivity or a higher reflectivity than the reflecting plate to remove a bright line or a dark line in the center of the display, respectively.
Claims18
A direct type back light comprising:
- a case;
- a plurality of lamps fixed inside said case, including at least two pairs of said lamps, wherein a first lamp of each pair of said lamps extends part away from proximate one side of said case toward an opposite side of said case and, after a gap, a second lamp of each pair of said lamps extends on toward the opposite side of said case;
- a reflecting plate arranged below said plurality of lamps;
- and
- a luminance control sheet located above said reflecting plate and below said plurality of lamps in an area of said gap,
- wherein said luminance control sheet has a reflective property which is different than a reflective property of said reflecting plate,
- wherein said luminance control sheet is separated from an adjacent luminance control sheet and is formed beneath each of curved portions of said lamps,
- wherein said at least one luminance control sheet has a width W and a length L to respectively fulfill the formulas of W=2x+2d and L=y where x is an outer curvature radius of a curve of a lamp of said plurality of lamps, y is a shortest distance between straight segments of said lamp, and d is a distance between curves of facing lamps, and
- wherein said at least one luminance control sheet is suspended from the lamp curve by a hanger.
A direct type back light comprising:
- a case;
- a plurality of curved lamps fixed inside said case including at least two pairs of said curved lamps, wherein ends of said curved lamps of each pair reside proximate a side of said case and the curved portions of said lamps face to each other, with a gap residing between the facing curved portions of pairs of said lamps;
- a reflecting plate arranged below said plurality of lamps;
- and
- at least one luminance control sheet located above said reflecting plate and below said plurality of lamps in respective areas of said gap,
- wherein said luminance control sheet has a reflective property which is different than a reflective property of said reflecting plate,
- wherein said luminance control sheet is separated from an adjacent luminance control sheet and is formed beneath each of the curved portions of said lamps,
- wherein said at least one luminance control sheet has a width W and a length L to respectively fulfill the formulas of W=2x+2d and L=y, where x is an outer curvature radius of a curve of a lamp of said plurality of lamps, y is a shortest distance between straight segments of said lamp, and d is a distance between curves of facing lamps, and
- wherein said at least one luminance control sheet is suspended from the lamp curve by a hanger.
Dependencies are inferred from the claim text.