LED lamps including LED work lights

• US 8,066,402 B2
• Filed: 12/21/2007
• Issued: 11/29/2011
• Est. Priority Date: 12/24/2006
• Status: Active Grant

• Current Assignee: Alltemp Products Company Limited (DiversiTech Holdings, Inc.)
• Original Assignee: Brasscorp Limited
• Inventors: Klipstein, Donald L.
• Primary Examiner(s): Ton; Anabel
• Assistant Examiner(s): ALLEN, DANIELLE NICOLE
• Application Number:
  US12/003,322
• Publication Number:
  US 20080212319A1
• Time in Patent Office: 1,439 Days
• Field of Search: 362/202, 362/203, 362/205, 362/208, 362/249.01
• US Class Current: 362/205
• CPC Class Codes: B60Q 3/35 Portable lighting devices
• CPC Class Codes: F21L 14/023 having two or more, or different light sources
• CPC Class Codes: F21L 4/06 with the light source coupled to the remainder of the device solely by cable
• CPC Class Codes: F21L 4/08 characterised by means for in situ recharging of the batteries or cells
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• CPC Class Codes: F21V 29/75 with fins or blades having different shapes, thicknesses or spacing
• CPC Class Codes: F21V 29/76 with essentially identical parallel planar fins or blades, e.g. with comb-like cross-section
• CPC Class Codes: F21V 29/83 the elements having apertures, ducts or channels, e.g. heat radiation holes
• CPC Class Codes: F21V 7/0091 using total internal reflection
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

Work light has LEDs that may require heatsink. Desired radiation pattern achieved by using optical components designed to produce beam or LEDs may have beams in different directions. Radiation pattern of LEDs may be changed by refractive-reflective optics or by convex lenses. Convex lenses may be hemispheres, other planoconvex shapes, concavo-convex shapes, or other shapes. Curved surfaces on any lenses may be spherical or aspheric. Ballast to operate the LEDs from line voltage AC or low voltage DC. Work light may contain batteries. The work light may be mounted on a stand. May have accessory mount. May have charging station. May have a paging transmitter to activate a paging receiver in work light. May have openings for heat transfer from heatsink to ambient air external to light.

Claims

1. A light emitting diode work light, comprising:

a handle section and a head section, and a plurality of light emitting diodes mounted in the head section, and means for the plurality of light emitting diodes to receive electrical power, wherein;

each light emitting diode within the plurality of light emitting diodes is associated with a lens that is located forward of its associated light emitting diode,

the lens associated with each light emitting diode in the plurality of light emitting diodes forms a beam by projecting an image of the forward region of its associated light emitting diode, and

wherein all of the said lenses associated with light emitting diodes in the plurality of light emitting diodes form beams that merge together to form a useful combined beam substantially between 40 and 90 degrees, and

wherein the plurality of light emitting diodes comprise;

one or more red light emitting diodes,

one or more green light emitting diodes,

one or more white light emitting diodes,

and wherein the plurality of light emitting diodes produces light that is mixed to produce a combined light output that has color approximating that of a blackbody radiator and having a correlated color temperature of 3,800 to 5,400 Kelvin, and wherein the photometric output from the one or more green light emitting diodes exceeds the photometric output of the one or more red light emitting diodes.

2. The light emitting diode work light of claim 1, wherein the lenses have focal length not greater than 1.4 times the width of the forward regions of their associated light emitting diodes.

3. The light emitting diode work light of claim 2, wherein the lenses have thickness at least half their diameters.

4. The light emitting diode work light of claim 2, wherein each lens has thickness greater than the distance between each lens and its associated light emitting diode.

5. The light emitting diode work light of claim 4, wherein each lens has thickness at least twice the distance between each lens and its associated light emitting diode.

6. The light emitting diode work light of claim 2, wherein each lens has a thickness equal to or greater than half the diameter of each lens.

7. The light emitting diode work light of claim 1, wherein the lenses are used to produce a beam having a higher percentage of the total light output being within the beam than would be the case if the lenses are omitted.

8. The light emitting diode work light of claim 7, wherein the lenses project a beam of light that is not narrower than that produced by the light emitting diodes.

9. The light emitting diode work light of claim 1, with the ratio of the photometric output from the one or more green light emitting diodes to the photometric output from the one or more red light emitting diodes exceeding 1.5.

10. The light emitting diode work light of claim 9, with the photometric output from the one or more green light emitting diodes being essentially approximating 1.8 times that from the red light emitting diodes.

11. The light emitting diode work light of claim 9, with the photometric content from the one or more green light emitting diodes being at least twice that of the red light emitting diodes.

12. The light emitting diode work light of claim 11, with the photometric content from the one or more green light emitting diodes being at least 3 times that from the one or more red light emitting diodes.

13. The light emitting diode work light of claim 1 where the red light emitting diodes contribute 3.5 to 18.5 percent of the total photometric output.

14. The light emitting diode work light of claim 1, wherein the white light emitting diodes contribute at least half of the photometric output.

15. A method of producing an light emitting diode work light, comprising:

a handle section and a head section, and a plurality of light emitting diodes mounted in the head section, and means for the plurality of light emitting diodes to receive electrical power, wherein;

each light emitting diode within the plurality of light emitting diodes is associated with a lens that is located forward of its associated light emitting diode,

the lens associated with each light emitting diode in the plurality of light emitting diodes forms a beam by projecting an image of the forward region of its associated light emitting diode, and

wherein all of the said lenses associated with light emitting diodes in the plurality of light emitting diodes form beams that merge together to form a useful combined beam substantially between 40 and 90 degrees,

wherein the plurality of light emitting diodes comprise;

one or more red light emitting diodes,

one or more green light emitting diodes,

one or more white light emitting diodes,

and wherein the plurality of light emitting diodes produces light that is mixed to produce a combined light output that has color approximating that of a blackbody radiator and having a correlated color temperature of 3,800 to 5,400 Kelvin,

the method comprising;

setting the percentage of photometric output contributed by each of the light emitting diode types needed to achieve white light of desirable chromaticity and color rendering properties as determined on the basis of the chromaticity of the light emitting diodes, the chromaticity of the combined white light to be achieved, percentage of photometric content of each light emitting diode type passing through a red filter, and desired percentage of the combined white light passing through a red filter.

16. A method of producing a light emitting diode work light, comprising:

a handle section and a head section, and a plurality of light emitting diodes mounted in the head section, and means for the plurality of light emitting diodes to receive electrical power, wherein;

each light emitting diode within the plurality of light emitting diodes is associated with a lens that is located forward of its associated light emitting diode,

the lens associated with each light emitting diode in the plurality of light emitting diodes forms a beam by projecting an image of the forward region of its associated light emitting diode, and

wherein all of the said lenses associated with light emitting diodes in the plurality of light emitting diodes form beams that merge together to form a useful combined beam substantially between 40 and 90 degrees,

wherein the plurality of light emitting diodes comprise;

one or more red light emitting diodes,

one or more green light emitting diodes,

one or more white light emitting diodes,

and wherein the plurality of light emitting diodes produces light that is mixed to produce a combined light output that has color approximating that of a blackbody radiator and having a correlated color temperature of 3,800 to 5,400,

the method comprising;

setting the percentage of photometric output from each of the light emitting diode types of the work light to achieve a desirable combined white color and desirable color rendering properties as determined by the percentage of the combined white light passing through a colored filter.

17. The method of claim 16, wherein the achieved percentage of combined light passing through the colored filter is essentially the same as that of sunlight.

18. The method of claim 16, wherein the achieved percentage of combined light passing through the colored filter is essentially the same as that of an incandescent lamp.

19. The method of claim 16, wherein the colored filter is a red filter.

20. The method of claim 19, wherein the method further comprises:

further adjusting the percentage of photometric content of the combined light from the green light emitting diodes in order to adjust the overall color to a desired shade of white.

21. The method of claim 16, wherein the percentage of light passing through the colored filter is considered on a photometric basis.

22. The method of claim 21, wherein the percentage of light passing through the colored filter is determined by using a light meter.