Surface light source device
First Claim
1. A surface light source device comprising:
- a light source; and
a light guide plate introducing light of the light source from a light incidence surface and emitting the light from a light exit surface to outside,wherein the light source is provided at a position facing the light incidence surface of the light guide plate,wherein the light guide plate comprises a light introducing part for enclosing the light from the light source entering from the light incidence surface and a light guide plate main body having a thickness smaller than a maximum thickness of the light introducing part, provided so as to be continued to the light introducing part, and emitting the enclosed light from the light exit surface by a light emitting portion to outside,wherein the light introducing part comprises an inclined surface inclined from a surface of a portion having a thickness larger than a thickness of the light guide plate main body toward an end of a surface of the light guide plate main body, the inclined surface being provided on at least one of a surface of the light guide plate on a light emission side and a surface opposite thereto,wherein the light guide plate comprises a directional conversion pattern for converting a directional spread of the light entering the light introducing part in a thickness direction of the light guide plate into a directional characteristic inclined to a direction parallel to a surface direction of the light guide plate, the directional conversion pattern being provided on at least one of the surface of the light guide plate on the light emission side and the surface opposite thereto,wherein the directional conversion pattern is configured so that ridge lines and valley lines are alternately repeated along a width direction of the light guide plate, andwherein, of a cross-section of the directional conversion pattern obtained by cutting in parallel to the light incidence surface, in a portion positioned in front of the light source and in a region having a width equal to a width of the light source;
an inclined surface connecting any ridge line of the ridge lines of the directional conversion pattern and one valley line adjacent to the ridge line and an inclined surface connecting the ridge line and another valley line adjacent to the ridge line being asymmetrical with respect to a straight line passing though the ridge line and perpendicular to the light exit surface, and at least one set of the asymmetrically-shaped portions of different shapes being present on both sides of a light source center, andin each of both sides of the light source center, when a normal is set on an inclined surface connecting adjacent ridge line and valley line of the directional conversion pattern from inside to outside of the light guide plate, a total sum of breadths of inclined surfaces each with the normal inclined to a light source center side is larger than a total sum of breadths of inclined surfaces each with the normal inclined to a side opposite to the light source center.
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0 Petitions
Accused Products
Abstract
A surface light source device has a light source, and a light guide plate introducing light of the light source from a light incidence surface and emitting the light from a light exit surface to outside. The light source being is provided at a position facing the light incidence surface of the light guide plate. The light guide plate includes a light introducing part for enclosing the light from the light source entering from the light incidence surface and a light guide plate main body having a thickness smaller than a maximum thickness of the light introducing part, provided so as to be continued to the light introducing part, and emitting the enclosed light from the light exit surface by light emitting portion to outside.
20 Citations
24 Claims
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1. A surface light source device comprising:
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a light source; and a light guide plate introducing light of the light source from a light incidence surface and emitting the light from a light exit surface to outside, wherein the light source is provided at a position facing the light incidence surface of the light guide plate, wherein the light guide plate comprises a light introducing part for enclosing the light from the light source entering from the light incidence surface and a light guide plate main body having a thickness smaller than a maximum thickness of the light introducing part, provided so as to be continued to the light introducing part, and emitting the enclosed light from the light exit surface by a light emitting portion to outside, wherein the light introducing part comprises an inclined surface inclined from a surface of a portion having a thickness larger than a thickness of the light guide plate main body toward an end of a surface of the light guide plate main body, the inclined surface being provided on at least one of a surface of the light guide plate on a light emission side and a surface opposite thereto, wherein the light guide plate comprises a directional conversion pattern for converting a directional spread of the light entering the light introducing part in a thickness direction of the light guide plate into a directional characteristic inclined to a direction parallel to a surface direction of the light guide plate, the directional conversion pattern being provided on at least one of the surface of the light guide plate on the light emission side and the surface opposite thereto, wherein the directional conversion pattern is configured so that ridge lines and valley lines are alternately repeated along a width direction of the light guide plate, and wherein, of a cross-section of the directional conversion pattern obtained by cutting in parallel to the light incidence surface, in a portion positioned in front of the light source and in a region having a width equal to a width of the light source; an inclined surface connecting any ridge line of the ridge lines of the directional conversion pattern and one valley line adjacent to the ridge line and an inclined surface connecting the ridge line and another valley line adjacent to the ridge line being asymmetrical with respect to a straight line passing though the ridge line and perpendicular to the light exit surface, and at least one set of the asymmetrically-shaped portions of different shapes being present on both sides of a light source center, and in each of both sides of the light source center, when a normal is set on an inclined surface connecting adjacent ridge line and valley line of the directional conversion pattern from inside to outside of the light guide plate, a total sum of breadths of inclined surfaces each with the normal inclined to a light source center side is larger than a total sum of breadths of inclined surfaces each with the normal inclined to a side opposite to the light source center. - View Dependent Claims (2, 3, 4, 10, 11, 12, 13, 14, 16, 17, 18, 19)
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5. A surface light source device comprising:
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a light source; and a light guide plate introducing light of the light source from a light incidence surface and emitting the light from a light exit surface to outside, wherein the light source is provided at a position facing the light incidence surface of the light guide plate, wherein the light guide plate comprises a light introducing part for enclosing the light from the light source entering from the light incidence surface and a light guide plate main body having a thickness smaller than a maximum thickness of the light introducing provided so as to be continued to the light introducing part, and emitting the enclosed light from the light exit surface by a light emitting portion to outside, wherein the light introducing part comprises an inclined surface inclined from a surface of a portion having a thickness larger than a thickness of the light guide late main body toward an end of a surface of the light guide plate main body, the inclined surface being provided on at least one of a surface of the light guide plate on a light emission side and a surface opposite thereto, wherein the light guide plate comprises a directional conversion pattern for converting a directional spread of the light entering the light introducing part in a thickness direction of the light guide plate into a directional characteristic inclined to a direction parallel to a surface direction of the light guide plate, the directional conversion pattern being provided on at least one of the surface of the light guide plate on the light emission side and the surface opposite thereto, wherein the directional conversion pattern is configured so that ridge lines and valley lines are alternately repeated along a width direction of the light guide plate, and wherein, of a cross-section of the directional conversion pattern obtained by cutting in parallel to the light incidence surface, in a portion positioned in front of the light source and in a region having a width equal to a width of the light source, an inclined surface connecting any ridge line of the ridge lines of the directional conversion pattern and one valley line adjacent to the ridge line and an inclined surface connecting the ridge line and another valley line adjacent to the ridge line being asymmetrical with respect to a straight line passing though the ridge line and perpendicular to the light exit surface, and at least one set of the asymmetrically-shaped portions of different shapes being present on both sides of a light source center, and in each of both sides of the light source center, when a normal is set on an inclined surface connecting adjacent ridge line and valley line of the directional conversion pattern from inside to outside of the light guide plate, an average angle of angles each formed by the normal inclined to the light source center side and a direction perpendicular to the light exit surface is smaller than an average angle of angles each formed by the normal inclined to the side opposite to the light source center and a direction perpendicular to the light exit surface. - View Dependent Claims (6, 7, 8, 9, 20, 21, 22, 23, 24)
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15. The surface light source device according to claim PE 1,
wherein a plurality of the light sources are placed at positions facing the light incidence surface, and wherein the directional conversion pattern is cyclically configured with an approximately center between adjacent ones of the light sources being taken as a boundary.
Specification