Emission device
First Claim
1. An emission device comprising:
- a light emitter composed of a point-like light source and a reflection means providing a reflection face arranged on a light outgoing side of said point-like light source as to surround said point-like light source sideways; and
an inner-propagation-medium in which output light of said light emitter inner-propagates,wherein a first intensity profile expressing directivity of output light of said light emitter has a half-intensity-angular-range which is not greater than 20°
with respect to an optical axis direction giving the maximum intensity, and said inner-propagation-medium has an emission face for emitting said output light after inner propagation, said emission face having an inside area extending around a position at which said emission face crosses said optical axis and an outside area extending as to surround said inside area;
said reflection face being inclined as to reflect light, which is emitted from said point-like light source and reaches said reflection face via inner-propagation-medium, mainly toward said outside area;
said inside area providing a lens surface which has a first traveling-direction-expanding-function for expanding traveling directions of light which is emitted from said point-like light source and reaches said inside area via inner-propagation-medium without impinging on said reflection face;
said outside area providing another lens surface which has a second traveling-direction-expanding-function for expanding traveling directions of light which is emitted from said point-like light source and reaches said outside area after being reflected by said reflection face via inner-propagation-medium;
said second traveling-direction-expanding-function is stronger than a traveling-direction-expanding-function which is effected in an imaginary case where said outside area is formed of a flat face perpendicular to said optical axis;
said first traveling-direction-expanding-function is weaker than said second traveling-direction-expanding-function; and
,a second intensity profile expressing directivity of a total output light composed of light emitted from said inside area and light emitted from said outside area has a half-intensity-angular-range which is not smaller than 30° and
not greater than 70°
with respect to said optical axis direction.
1 Assignment
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Accused Products
Abstract
Provided is a light emitting device having an inner-propagation-medium which caused directivity-to-optical-axis-direction to be relaxed. Light of a LED travels in the inner-propagation-medium, being emitted from an inside area of or outside area in a lens surface directly or via an inclined reflection face. A light emitter provides an output light having an intensity profile with a half-intensity-angular-range not greater than 20°, which expresses directivity of the output light. The outside area in the lens surface performs a traveling-direction-expanding-function which is not only relatively intensive as compared that performed by the inside area in the lens surface, and but also relatively intensive as compared that performed in an imaginary case where the outside area gives a planar surface perpendicular to an optical axis. The half-intensity-angular-range of the intensity profile of the light emitting device is not smaller than 30° with respect to the optical axis and not greater than 70°. The lens face may be formed of one or more convex surfaces in the outside area.
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Citations
3 Claims
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1. An emission device comprising:
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a light emitter composed of a point-like light source and a reflection means providing a reflection face arranged on a light outgoing side of said point-like light source as to surround said point-like light source sideways; and an inner-propagation-medium in which output light of said light emitter inner-propagates, wherein a first intensity profile expressing directivity of output light of said light emitter has a half-intensity-angular-range which is not greater than 20°
with respect to an optical axis direction giving the maximum intensity, and said inner-propagation-medium has an emission face for emitting said output light after inner propagation, said emission face having an inside area extending around a position at which said emission face crosses said optical axis and an outside area extending as to surround said inside area;said reflection face being inclined as to reflect light, which is emitted from said point-like light source and reaches said reflection face via inner-propagation-medium, mainly toward said outside area; said inside area providing a lens surface which has a first traveling-direction-expanding-function for expanding traveling directions of light which is emitted from said point-like light source and reaches said inside area via inner-propagation-medium without impinging on said reflection face; said outside area providing another lens surface which has a second traveling-direction-expanding-function for expanding traveling directions of light which is emitted from said point-like light source and reaches said outside area after being reflected by said reflection face via inner-propagation-medium; said second traveling-direction-expanding-function is stronger than a traveling-direction-expanding-function which is effected in an imaginary case where said outside area is formed of a flat face perpendicular to said optical axis; said first traveling-direction-expanding-function is weaker than said second traveling-direction-expanding-function; and
,a second intensity profile expressing directivity of a total output light composed of light emitted from said inside area and light emitted from said outside area has a half-intensity-angular-range which is not smaller than 30° and
not greater than 70°
with respect to said optical axis direction. - View Dependent Claims (2, 3)
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Specification