Solid state light fixtures suitable for high temperature operation having separate blue-shifted-yellow/green and blue-shifted-red emitters

• US 9,786,639 B2
• Filed: 08/03/2016
• Issued: 10/10/2017
• Est. Priority Date: 12/03/2015
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Bergmann, Michael John, Tudorica, Florin, DeSena, Jr., P. Joseph
• Primary Examiner(s): Han, Jonathan
• Application Number:
  US15/226,992
• Publication Number:
  US 20170162547A1
• Time in Patent Office: 433 Days
• Field of Search: 257 81, 257 82, 257 91, 257 98, 257 99, 257100, 257116, 257117, 257432-437, 257749, 257E33056-E33059, 257E25032
• CPC Class Codes: F21K 9/232 specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
• CPC Class Codes: F21K 9/27 Retrofit light sources for lighting devices with two fittings for each light source, e.g. for substitution of fluorescent tubes
• CPC Class Codes: F21K 9/62 using mixing chambers, e.g. housings with reflective walls
• CPC Class Codes: F21K 9/66 Details of globes or covers forming part of the light source
• CPC Class Codes: F21K 9/68 Details of reflectors forming part of the light source
• CPC Class Codes: F21S 8/04 intended only for mounting on a ceiling or the like overhead structures F21S8/02 takes precedence; details of ceiling bases F21V21/03
• CPC Class Codes: F21V 29/74 with fins or blades
• CPC Class Codes: F21V 3/061 the material being glass
• CPC Class Codes: F21V 3/062 the material being plastics
• CPC Class Codes: F21V 3/10 characterised by coatings
• CPC Class Codes: F21Y 2103/10 comprising a linear array of point-like light-generating elements
• CPC Class Codes: F21Y 2105/12 characterised by the geometrical disposition of the light-generating elements, e.g. arranging light-generating elements in differing patterns or densities
• CPC Class Codes: F21Y 2105/16 square or rectangular, e.g. for light panels
• CPC Class Codes: F21Y 2105/18 annular; polygonal other than square or rectangular, e.g. for spotlights or for generating an axially symmetrical light beam
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
• CPC Class Codes: H05B 45/00 : Circuit arrangements for operating light-emitting diodes [LED]
• CPC Class Codes: H05B 45/20 : Controlling the colour of the light
• CPC Class Codes: H05B 45/325 : Pulse-width modulation [PWM]
• CPC Class Codes: H05B 45/3725 : Switched mode power supply [SMPS]

Abstract

Solid state light fixtures include a plurality of blue-shifted-yellow/green light emitting diode (“LED”) packages and a plurality of blue-shifted-red LED packages, where the solid state light fixture emits light having a correlated color temperature of between 1800 K and 5500 K, a CRI value of between 80 and 99, a CRI R9 value of between 15 and 75, and a Qg value of between 90 and 110 when the blue-shifted-yellow/green LED packages and the blue-shifted-red LED packages are operating at steady-state operating temperatures of at least 80° C.

Claims

1. A light emitting diode (LED) based light fixture, comprising:

a plurality of blue-shifted-yellow/green LED packages, the blue-shifted-yellow/green LED packages including low-phosphor LED packages and high phosphor LED packages, the high phosphor LED packages having a higher phosphor conversion ratio than the low phosphor LED packages; and

a plurality of blue-shifted-red LED packages,

wherein the blue-shifted-red LED packages extend in a first row, and

wherein a first subset of the blue-shifted-yellow/green LED packages extend in a second row on a first side of the blue-shifted-red LED packages and a second subset of the blue-shifted-yellow/green LED packages extend in a third row on a second side of the blue-shifted-red LED packages that is opposite the first side.

2. The LED based light fixture of claim 1, wherein the blue-shifted-yellow/green LED packages in the second row include both low phosphor LED packages and high phosphor LED packages.

3. The LED based light fixture of claim 2, wherein the blue-shifted-red LED packages are electrically connected in series to form a first LED string and the low phosphor LED packages are electrically connected in series to form a second LED string, wherein the second LED string crosses the first LED string in at least four locations.

4. The LED based light fixture of claim 3, wherein the high phosphor LED packages are electrically connected in series to form a third LED string, and wherein the third LED string crosses the first LED string in at least four locations.

5. The LED based light fixture of claim 1, wherein a first end of the second row extends beyond a first end of the first row, and a second end of the second row extends beyond a second end of the first row.

6. The LED based light fixture of claim 1, wherein the high phosphor LED packages each include a first amount of a first phosphor and the low phosphor LED packages each include a second amount of the first phosphor, wherein the first amount is between twice and seven times the second amount.

7. The LED based light fixture of claim 1, wherein an average separation between adjacent ones of the blue-shifted-red LED packages in the first row is less than an average separation between adjacent ones of the blue-shifted-yellow/green LED packages in the second row.

8. The LED based light fixture of claim 1, wherein all of the LED packages in the second row are not spaced apart from adjacent LED packages in the second row by a uniform amount, and wherein all of the LED packages in the third row are not spaced apart from adjacent LED packages in the second row by a uniform amount.

9. A tunable light emitting diode (LED) based light fixture, comprising:

a plurality of blue-shifted-yellow/green LED packages, the blue-shifted-yellow/green LED packages including low-phosphor LED packages that each include a first amount of a first phosphor and high phosphor LED packages that each include a second amount of the first phosphor; and

a plurality of blue-shifted-red LED packages;

wherein the second amount is between twice and seven times the first amount.

10. The tunable LED based light fixture of claim 9, wherein the blue-shifted-red LED packages extend in a first row and the blue-shifted-yellow/green LED packages extend in a second row and in a third row, with the second row extending on a first side of the first row and the third row extending on a second side of the first row that is opposite the first side.

11. The tunable LED based light fixture of claim 10, wherein the second row includes both low phosphor LED packages and high phosphor LED packages, and wherein the third row includes both low phosphor LED packages and high phosphor LED packages.

12. The tunable LED based light fixture of claim 9, wherein the blue-shifted-red LED packages are electrically connected in series to form a first LED string and the low phosphor LED packages are electrically connected in series to form a second LED string, and wherein the second LED string crosses the first LED string in at least four locations.

13. The tunable LED based light fixture of claim 10, wherein a second line defined by the second row has respective endpoints that extend beyond respective endpoints of a first line defined by the first row.

14. The tunable LED based light fixture of claim 10, wherein an average separation between adjacent ones of the blue-shifted-red LED packages in the first row is less than an average separation between adjacent ones of the blue-shifted-yellow/green LED packages in the second row.

15. The LED based light fixture of claim 9, wherein a total number of blue-shifted-red LED packages included in the LED based light fixture is greater than 0.75 times a total number of blue-shifted-yellow/green LED packages included in the LED based light fixture.

16. A light emitting diode (LED) based light fixture, comprising:

a plurality of blue-shifted-yellow/green LED packages, the blue-shifted-yellow/green LED packages including low-phosphor LED packages and high phosphor LED packages, the high phosphor LED packages having a higher phosphor conversion ratio than the low phosphor LED packages; and

a plurality of blue-shifted-red LED packages,

wherein the blue-shifted-yellow/green LED packages surround the blue-shifted-red LED packages.

17. The LED based light fixture of claim 16, wherein at least some of the blue-shifted-yellow/green LED packages are arranged in a first circle and the blue-shifted-red LED packages are arranged in a second circle that is within the first circle.

18. The LED based light fixture of claim 17, wherein additional of the blue-shifted-yellow/green LED packages are arranged in a third first circle that is within the second circle.

19. The LED based light fixture of claim 16, wherein the blue-shifted-yellow/green LED packages in the first circle include both low phosphor LED packages and high phosphor LED packages that are arranged in alternating order.

20. The LED based light fixture of claim 16, wherein the high phosphor LED packages each include a first amount of a first phosphor and the low phosphor LED packages each include a second amount of the first phosphor, wherein the first amount is between twice and seven times the second amount.