Solid state white light emitter and display using same

• US 8,963,182 B2
• Filed: 01/08/2013
• Issued: 02/24/2015
• Est. Priority Date: 03/26/1996
• Status: Expired due to Fees

• Current Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Baretz, Bruce H., Tischler, Michael A.
• Primary Examiner(s): Luu, Chuong A
• Assistant Examiner(s): FORTICH, RODOLFO D
• Application Number:
  US13/736,789
• Publication Number:
  US 20130120968A1
• Time in Patent Office: 777 Days
• Field of Search: 257/98, 257/79, 257/88, 257/E33.06, 257/40
• US Class Current: 257/98
• CPC Class Codes: G09F 13/04 Signs, boards or panels, illuminated from behind the insignia
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/48139 with an intermediate bond, e.g. continuous wire daisy chain
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: Y02E 10/52 PV systems with concentrators

Abstract

A light emitting assembly comprising a solid state device coupleable with a power supply constructed and arranged to power the solid state device to emit from the solid state device a first, relatively shorter wavelength radiation, and a down-converting luminophoric medium arranged in receiving relationship to said first, relatively shorter wavelength radiation, and which in exposure to said first, relatively shorter wavelength radiation, is excited to responsively emit second, relatively longer wavelength radiation. In a specific embodiment, monochromatic blue or UV light output from a light-emitting diode is down-converted to white light by packaging the diode with fluorescent organic and/or inorganic fluorescers and phosphors in a polymeric matrix.

Claims

1. A light emitting device, comprising:

an array of LEDs, wherein each LED is configured to emit blue light; and

luminophoric medium configured to interact with emitted blue light from the LEDs in said array to produce down-converted light,

wherein the luminophoric medium includes red emissive and yellow emissive species and the emitted blue light from the LEDs in said array and the down-converted light produce a white light output, wherein the array of LEDs is in a housing, and wherein one of said emissive species is in contact with the array of LEDs, and the other of said emissive species is in spaced relation to said array of LEDs, and

wherein said red emissive species of said luminophoric medium is in contact with the array of LEDs, and the yellow emissive species of the luminophoric medium is in spaced relation to said array of LEDs.

2. The light emitting device of claim 1, further comprising a light-transmissive wall comprised in said housing.

3. A light emitting device, comprising:

multiple LEDs each configured to emit blue light; and

a same luminophoric medium configured to interact with emitted blue light from the multiple LEDs to produce down-converted light,

wherein the emitted blue light from the multiple LEDs and said down-converted light produce a white light output,

wherein the luminophoric medium comprises an inorganic luminophor, and

wherein each of the multiple LEDs is electrically connected with electrical circuitry and a controller arranged to control illumination of the device, and

wherein the controller is arranged to control illumination from the device through control of individual LEDs in response to user input.

4. The light emitting device of claim 3, wherein the controller controls the intensity of the LEDs.

5. The light emitting device of claim 3, in a display.

6. The light emitting device of claim 5, arranged for back lighting of the display.

7. The light emitting device of claim 3, arranged for backlighting of a display.

8. The light emitting device of claim 3, wherein the controller is arranged to control illumination from the device through control of all LEDs simultaneously in response to user input.

9. The light emitting device of claim 8, wherein the device is arranged for back lighting of a display.