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US 6,685,330 B2Granted
Backlight apparatus that can assure uniform brightness
AssigneeFujitsu Limited
InventorShingo Miyazaki
Life of this patent
Estimating the term…
Abstract
A backlight apparatus includes a point light source, a linear light guide, a plane light guide, and a light shield unit. Rays of light radiated by the point light source travel through the linear light guide and the plane light guide, and are output to an illuminated object. The light shield unit shuts out a leaking fraction of rays of light that travels directly from the point light source to the plane light guide, thereby assuring uniform brightness of the output light.
Claims7
A backlight apparatus, comprising:
- a point light source that emits light;
- a linear light guide that is provided by said point light source with said light through an incident side face, diffuses said light therein, and radiates said light through an outgoing side face, said light radiating through said outgoing side face being linearized;
- a plane light guide that is provided by said linear light guide with said light through an incident side face, diffuses said light therein, and radiates said light through an outgoing face facing an illuminated object;
- and
- a light shield unit that prevents a leaking fraction of said light from going directly into said plane light guide.
2 more elements
Dependencies are inferred from the claim text.