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US 8,008,694 B2Granted
Brightness enhancement method and apparatus of light emitting diodes
AssigneeYLX Incorporated
InventorsLi Xu, Yi Li
Life of this patent
Estimating the term…
Abstract
A light source with enhanced brightness includes an angle-selective optical filter and a light emitting diode (LED) having a high reflective layer. The angle-selective filter is located on the top surface of emitting diode to pass lights at specified angles. According to one embodiment, the angle-selective filter includes index-alternating layers. With a reflective polarizer, the light source can produce polarized light with enhanced brightness.
Claims20
A light emitting diode device comprising:
- a) a light emitting diode (LED) chip with a highly reflective layer;
- b) an angle-selective filter that transmits light with incidence angles smaller than a selective angle and reflects light with incidence angles larger than the selective angle;
- and
- c) an air gap located between the LED chip and the angle-selective filter.
1 more element
A light emitting diode device comprising:
- a) a light emitting diode (LED) chip with a highly reflective layer;
- b) an angle-selective filter that transmits light with incidence angles smaller than a selective angle and reflects light with incidence angles larger than the selective angle;
- and
- c) a polarizer located adjacently to the angle-selective filter in a light exit direction.
1 more element
A device, comprising:
- a light emitting layer which emits light;
- a substrate that transmits the emitted light, the light emitting layer formed over a first side of the substrate;
- a reflective layer formed over the first side of the substrate to reflect the emitted light, the light emitting layer positioned between the reflective layer and the substrate;
- and
- an angle-selective filter formed on a second side of the substrate, the angle-selective filter reflecting a light ray of the emitted light at an incident angle greater than a predefined incident angle and transmitting a light ray of the emitted light at an incident angle less than the predefined incident angle.
2 more elements
A device, comprising:
- a light emitting diode (LED) chip to emit light;
- a reflective layer formed over a first side of the LED chip to reflect the emitted light;
- and
- an angle-selective filter formed on a second side of the LED chip, the angle-selective filter reflecting a light ray of the emitted light at an incident angle greater than a predefined incident angle and transmitting a light ray of the emitted light at an incident angle less than the predefined incident angle.
1 more element
Dependencies are inferred from the claim text.