News Column

Researchers Submit Patent Application, "Solid State Lighting Device", for Approval

June 25, 2014



By a News Reporter-Staff News Editor at Electronics Newsweekly -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventors Pickard, Paul Kenneth (Morrisville, NC); Medendorp, JR., Nicholas W. (Raleigh, NC); Harris, Michael James (Cary, NC); Lay, James Michael (Cary, NC), filed on February 10, 2014, was made available online on June 12, 2014.

The patent's assignee is Cree, Inc.

News editors obtained the following quote from the background information supplied by the inventors: "A large proportion (some estimates are as high as twenty-five percent) of the electricity generated in the United States each year goes to lighting. It is well known that incandescent light bulbs are very energy-inefficient light sources--about ninety percent of the electricity they consume is released as heat rather than light. Fluorescent light bulbs are more efficient than incandescent light bulbs (by a factor of about 10) but are still less efficient than solid state light emitters, such as light emitting diodes (LEDs).

"Although the development of light emitting diodes has in many ways revolutionized the lighting industry, some of the characteristics of light emitting diodes have presented challenges, some of which have not yet been fully met. Efforts have been ongoing to develop lighting devices that are improved, e.g., with respect to energy efficiency, color rendering index (CRI Ra), contrast, efficacy (lm/W), and/or duration of service. In addition, efforts have been ongoing to develop lighting devices that include solid state light emitters instead of other forms of light emitters. Ideally, the cost of such lighting devices should be comparable with traditional incandescent lighting to facilitate their acceptance and utilization.

"Many modern lighting applications utilize high power solid state emitters to provide a desired level of brightness, which can draw large currents, thereby generating significant amounts of heat that must be dissipated to maintain the output of the solid state emitters. Many solid state lighting systems utilize heatsinks in thermal communication with the heat-generating solid state light sources, whereas heatsinks of substantial size and/or subject to exposure to a surrounding environment, aluminum is commonly employed by forming in various shapes by casting, extrusion, and/or machining techniques. Leadframe-based solid state emitter packages also utilize chip-scale heatsinks, with such heatsinks and/or leadframes being fabricated by techniques including stamping with such chip-scale heatsinks typically being arranged along a single non-emitting (e.g., lower) package surface to promote thermal conduction to a surface on which the package is mounted. Such chip-scale heatsinks are generally used as intermediate heat spreaders to conduct heat to other device-scale heat dissipation structures, such as cast or machined heatsinks."

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventors' summary information for this patent application: "In a first embodiment, a solid state lighting device is provided. The lighting devices comprises a plurality of solid state emitters; a heat spreader plate of thermally conductive material having a base in thermal communication with the plurality of solid state emitters, and at least one sidewall projecting from the base. The plurality of solid state emitters provides a thermal load upon application of an operating current and voltage, the heat spreader plate dissipating at least a portion of the thermal load to an ambient air environment.

"In a second embodiment, a solid state lighting device is provided. The lighting device comprises a plurality of solid state emitters, the plurality of solid state emitters provides a total luminosity of about 700 lumens to about 800 lumens at about 110 lumens per Watt to about 170 lumens per Watt, about 2500 K to about 2900 K correlated color temperature, and greater than or equal to 90 color rendering index, and generating a thermal load not more than about 5 Watts; a heat spreader plate of thermally conductive material having a base in thermal communication with the plurality of solid state emitters, and at least one sidewall projecting in a direction non-parallel from the longitudinal axis of the base. The plurality of solid state emitters generates a total thermal load of less than about 5 Watts upon application of an operating current and voltage, the heat spreader plate dissipating at least a portion of the thermal load to an ambient air environment.

"In a third embodiment, a solid state lighting device is provided. The lighting device comprises a plurality of chip-scale solid state emitters; the plurality of chip-scale solid state emitters providing a total luminosity of about 700 lumens to about 800 lumens at about 110 lumens per Watt to about 170 lumens per Watt, and generating a thermal load not more than about 5 Watts; a device-scale heat spreader plate in thermal communication with the at least one chip-scale solid state emitter, the device-scale heat spreader having a base and at least one sidewall portion projecting substantially non-parallel from the longitudinal axis of the base, the heat spreader plate dissipating at least a portion of the thermal load to an ambient air environment, the device scale heat spreader plate having a thermal conductivity of at least 10 W/m-K.

"In a fourth embodiment, a lamp or light fixture comprising the lighting device of either the first, second embodiment, and/or third embodiment are provided.

BRIEF DESCRIPTION OF THE DRAWINGS

"FIGS. 1A, 1B, and 1C are a perspective view, a bottom perspective view, and a side perspective view, respectively, of a heat spreader plate embodiment as disclosed and described herein;

"FIG. 2 is a perspective view of alternate embodiment heat spreader plate as disclosed and described herein;

"FIG. 3 is a perspective view of alternate embodiment heat spreader plate as disclosed and described herein;

"FIG. 4 is a top perspective view of alternate embodiment heat spreader plate as disclosed and described herein;

"FIG. 5 is a top perspective view of alternate embodiment heat spreader plate as disclosed and described herein;

"FIG. 6 is a sectional view of a lighting device fixture with the heat spreader plate embodiment similar to that of FIG. 3 as disclosed and described herein;

"FIG. 7 is a sectional view of a lighting device fixture with a heat spreader plate embodiment as disclosed and described herein;

"FIG. 8 is a sectional view of a lighting device fixture with the heat spreader plate embodiment similar to that of FIG. 2 as disclosed and described herein;

"FIG. 9 is a sectional view of a lighting device fixture with a heat spreader plate embodiment similar to that of FIG. 1 as disclosed and described herein;

"FIG. 10 is an exploded perspective view of an exemplary low-cost lighting device having a heat spreader plate embodiment as disclosed and described herein;

"FIG. 11 is a perspective view of an exemplary low-cost lighting device having a heat spreader plate embodiment as disclosed and described herein;

"FIG. 12 is a perspective view of a partially assembled exemplary low-cost lighting device having a heat spreader plate embodiment and non-metallic trim, as disclosed and described herein; and

"FIG. 13 is a perspective view of an exemplary low-cost lighting device having a heat spreader plate embodiment and non-metallic trim, as disclosed and described herein."

For additional information on this patent application, see: Pickard, Paul Kenneth; Medendorp, JR., Nicholas W.; Harris, Michael James; Lay, James Michael. Solid State Lighting Device. Filed February 10, 2014 and posted June 12, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=4239&p=85&f=G&l=50&d=PG01&S1=20140605.PD.&OS=PD/20140605&RS=PD/20140605

Keywords for this news article include: Cree Inc., Light Bulb, Electronics, Light-emitting Diode.

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Source: Electronics Newsweekly