Backlight Using High-Powered Corner LED
First Claim
1. A light emitting device comprising:
- a light emitting diode (LED) die;
a reflective cavity housing the LED die, the cavity having an opening for light to exit, the opening having a cross-sectional area of at least 4 mm2; and
a substantially rectangular light guide formed of a solid material having at least a first truncated corner, the truncated corner having a face, the light guide adapted for supplying light as a backlight;
the opening of the reflective cavity opposing the face of the truncated corner such that light exiting the opening of the reflective cavity is coupled into the light guide through the face of the corner,where the LED die is at least 1 mm from the face of the truncated corner.
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Accused Products
Abstract
Various embodiments of corner-coupled backlights are described, where one or more LEDs are optically coupled to a truncated corner of a solid rectangular light guide backlight. In one embodiment, a high-power, white light LED is mounted in a small reflective cavity, which is then coupled to a flattened corner of the light guide. The reflective cavity provides a more uniform light distribution at a wide variety of angles to the face of the truncated corner to better distribute light throughout the entire light guide volume. This creates a more uniform light guide emission into the liquid crystal layers. In other embodiments, an LED is mounted in a small cavity near a corner of the light guide, and a reflector is mounted on the corner of the light guide. Various techniques for removing heat from the LED without adding additional area requirements are also disclosed.
113 Citations
48 Claims
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1. A light emitting device comprising:
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a light emitting diode (LED) die; a reflective cavity housing the LED die, the cavity having an opening for light to exit, the opening having a cross-sectional area of at least 4 mm2; and a substantially rectangular light guide formed of a solid material having at least a first truncated corner, the truncated corner having a face, the light guide adapted for supplying light as a backlight; the opening of the reflective cavity opposing the face of the truncated corner such that light exiting the opening of the reflective cavity is coupled into the light guide through the face of the corner, where the LED die is at least 1 mm from the face of the truncated corner. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
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35. A light emitting device comprising:
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a light emitting diode (LED) die; a substantially rectangular light guide formed of a solid material having at least a first corner; and the light guide having a cavity proximate to the first corner, the light guide adapted for supplying light as a backlight, the LED die being mounted so as to emit light into the cavity formed in the light guide. - View Dependent Claims (36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48)
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Specification