Surface light source device with half-ellipse reflecting plate
First Claim
1. A surface light source device, comprising a plurality of line light sources positioned immediately under a diffusion plate, and a reflecting plate for reflecting a light from each of said line light sources, wherein:
- a cross-section perpendicular to the line light source of said reflecting plate is arranged to form at least two elliptical sections of two intersecting ellipses where the two ellipses commonly share a focal point and are divided by a straight line, the straight line includes the focal point commonly shared and two other focal points; and
said reflecting plate at least partially encloses the line light source and reflects light from the light source toward the diffusion plate by specular reflection and by diffuse reflection.
1 Assignment
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Accused Products
Abstract
A reflecting plate in form of dual half-ellipses comprises a first ellipse having a first focal point and a second focal point, and a second ellipse having a first focal point and a second focal point. The first ellipse and the second ellipse commonly share the first focal point. A cross-section of the reflecting plate is designed in such a form that the dual half-ellipses are aligned with each other, and that contours of the first ellipse and the second ellipse are divided by a straight line, which includes the commonly shared first focal point and the other focal points. The reflecting plate encloses the line light source by the dual half-ellipses and reflects a light from the line light source toward the diffusion plate arranged above by specular reflection and by diffused reflection. As a result, uneven brightness is eliminated at the boundary of the reflecting plate designed in form of dual half-ellipses.
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Citations
15 Claims
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1. A surface light source device, comprising a plurality of line light sources positioned immediately under a diffusion plate, and a reflecting plate for reflecting a light from each of said line light sources, wherein:
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a cross-section perpendicular to the line light source of said reflecting plate is arranged to form at least two elliptical sections of two intersecting ellipses where the two ellipses commonly share a focal point and are divided by a straight line, the straight line includes the focal point commonly shared and two other focal points; and said reflecting plate at least partially encloses the line light source and reflects light from the light source toward the diffusion plate by specular reflection and by diffuse reflection. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A surface light source device, comprising a plurality of line light sources positioned immediately under a diffusion plate, and a reflecting plate for reflecting a light from each of said line light sources, wherein:
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a cross-section perpendicular to the line light sources of said reflecting plate is arranged to form at least two elliptical sections of two intersecting ellipses where the two ellipses commonly share a focal point and are divided by a straight line parallel to the diffusion plate, the straight line intersects the major axis of the two ellipses sharing the focal point between the commonly shared focal point positioned closer to the reflecting plate and a focal point positioned closer to the diffusion plate; and said reflecting plate at least partially encloses the line light source located at the commonly shared focal point and reflects a light from the line light source toward the diffusion plate by specular reflection and by diffuse reflection. - View Dependent Claims (12, 13)
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14. A surface light source device, comprising a plurality of line light sources positioned immediately under a diffusion plate, and a reflecting plate for reflecting a light from each of said line light sources, wherein:
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a cross-section of said reflecting plate perpendicular to the line light source is arranged to form at least two elliptical sections of two intersecting ellipses where the major axis of the ellipses are positioned to intersect in a proximity of the reflecting plate and the elliptical sections are divided by a straight line parallel to the diffusion plate and including a focal point of each ellipse positioned closer to the reflecting plate; and said reflecting plate at least partially encloses the line light source located at the axis of symmetry of the focal points of each intersecting ellipses, and the reflecting plate reflects a light from the line light source toward the diffusion plate by specular reflection and by diffuse reflection. - View Dependent Claims (15)
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Specification