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US 2008/0304285 A1Published application
Planar lighting device
AssigneeFUJIFILM Corporation
InventorOsamu IWASAKI
Life of this patent
Estimating the term…
Abstract
A thinner and larger planar lighting device is achieved without increasing the number of light sources and holding the power consumption to a minimum. The LED chips on the light sources are arrayed at an array density varying according to the position of each of the light entrance planes of the light guide plate such that the illuminance distribution as measured on along the middle of the light guide plate in a direction parallel to longitudinal direction of the light entrance planes represents a high-in-the-middle, bell-curve distribution.
Claims15
A planar lighting device comprising:
- a light guide plate including
- a light exit plane being flat for emitting planar light,
- a pair of light entrance planes, each for admitting light traveling parallel to said light exit plane, and each being formed along each of a pair of opposite sides of said light exit plane, and
- rear planes formed on a side opposite from said light exit plane and inclined such that a thickness of said light guide plate in a direction perpendicular to said light exit plane grows thicker with an increasing distance from each of said pair of light entrance planes and joining each other in a middle between said pair of light entrance planes, and
- a pair of light sources, each for emitting the light to each of said pair of light entrance planes and for admitting the emitted light through each of said pair of light entrance planes, and each being disposed opposite each of said pair of light entrance planes of said light guide plate,
- wherein each of said pair of light sources has LED chips and a support for supporting said LED chips, and
- wherein said LED chips of each of said pair of light sources are arrayed on a plane of said support facing each of said pair of light entrance planes at a varying array density in a longitudinal direction of each of said pair of light entrance planes.
4 more elements
A planar lighting device comprising:
- a light guide plate including
- a light exit plane being flat for emitting planar light,
- a pair of light entrance planes, each for admitting light traveling parallel to said light exit plane, and each being formed along each of a pair of opposite sides of said light exit plane, and
- rear planes formed on a side opposite from said light exit plane and inclined such that a thickness of said light guide plate in a direction perpendicular to said light exit plane grows thicker with an increasing distance from each of said pair of light entrance planes and joining each other in a middle between said pair of light entrance planes, and
- a pair of light sources, each for emitting the light to each of said pair of light entrance planes and for admitting the emitted light through each of said pair of light entrance planes, and each being disposed opposite each of said pair of light entrance planes of said light guide plate,
- wherein each of said pair of light sources has LED chips and a support for supporting said LED chips, and
- wherein said LED chips of each of said pair of light sources are arrayed on a plane of said support facing each of said pair of light entrance planes in a longitudinal direction of each of said pair of light entrance planes and comprise LEDs for emitting light having different amounts of light, respectively.
4 more elements
A planar lighting device comprising:
- a light guide plate including
- a light exit plane being flat for emitting planar light,
- a pair of light entrance planes, each for admitting light traveling parallel to said light exit plane, and each being formed along each of a pair of opposite sides of said light exit plane, and
- rear planes formed on a side opposite from said light exit plane and inclined such that a thickness of said light guide plate in a direction perpendicular to said light exit plane grows thicker with an increasing distance from each of said pair of light entrance planes and joining each other in a middle between said pair of light entrance planes, and
- a pair of light sources, each for emitting the light to each of said pair of light entrance planes and for admitting the emitted light through each of said pair of light entrance planes, and each being disposed opposite each of said pair of light entrance planes of said light guide plate,
- wherein each of said pair of light sources has LED chips and a support for supporting said LED chips,
- wherein said LED chips of each of said pair of light sources are arrayed on a plane of said support facing each of said pair of light entrance planes in a longitudinal direction of each of said pair of light entrance planes, and
- wherein said light emitted from each of said pair of light sources and admitted through each of said pair of light entrance planes has an amount distribution of light that is different in said longitudinal direction of each of said pair of light entrance planes.
5 more elements
Dependencies are inferred from the claim text.