Lighting Device Utilizing a Double Fresnel Lens

• US 20150204491A1
• Filed: 10/29/2014
• Published: 07/23/2015
• Est. Priority Date: 01/21/2014
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Yuan, Zongjie, Wilcox, Kurt S., Patkus, Steven, Beck, Benjamin P., Barglind, Lisa Marie, Couch, William Herschel
• Granted Patent: US 9,464,778 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F21V 5/007 Array of lenses or refractors for a cluster of light sources, e.g. for arrangement of multiple light sources in one plane combination of two or more refractors F21V5/008
• CPC Class Codes: F21V 5/045 the lens having discontinuous faces, e.g. Fresnel lenses

Abstract

According to one aspect, an optical lens includes a substrate having a first side and a second side opposite the first side. The optical lens includes a first pattern of Fresnel features having a first focal length disposed on the first side and a second pattern of Fresnel features having a second focal length disposed on the second side. The first pattern of Fresnel features is disposed perpendicular to the second pattern of Fresnel features, and the first focal length is different from the second focal length.

Claims

1. An optical lens comprising:

a substrate having a first side and a second side opposite the first side;

a first pattern of Fresnel features having a first focal length disposed on the first side; and

a second pattern of Fresnel features having a second focal length disposed on the second side;

wherein the first pattern of Fresnel features is disposed perpendicular to the second pattern of Fresnel features, and

wherein the first focal length is different from the second focal length.

2. The optical lens of claim 1, wherein the first and second patterns of Fresnel features are linear.

3. The optical lens of claim 2, wherein the first and second patterns of Fresnel features create a grid-like array of lenslets.

4. The optical lens of claim 3, wherein at least one lenslet is configured to align with the light of an LED.

5. The optical lens of claim 1, wherein the first and second focal lengths range from 0.5 to 2.0 times the spacing distance between LEDs of an LED array.

6. The optical lens of claim 1, wherein the first and second focal lengths are based on the distance from a light source to respective first and second patterns of Fresnel features.

7. The optical lens of claim 1, wherein the first and second patterns of Fresnel features are separated by a thickness of the substrate.

8. The optical lens of claim 1, wherein the substrate is formed from a translucent material.

9. The optical lens of claim 1, wherein the substrate is comprised of one of acrylic, air, molded silicone, polycarbonate, glass, cyclic olefin copolyments, and combinations thereof.

10. The optical lens of claim 1, wherein the first pattern of Fresnel features and the second pattern of Fresnel features are formed and disposed on the substrate by one of the following methods:

embossing;

molding;

screen printing;

machining;

laser-forming; and

laminating.

11. The optical lens of claim 1, wherein the first pattern of Fresnel features includes repeating units of Fresnel features extending along the substrate in a first direction, and the second pattern of Fresnel features includes repeating units of Fresnel features extending along the substrate in a second direction, perpendicular to the first direction.

12. The optical lens of claim 1, wherein each unit of Fresnel features of the first and second patterns include a convex lens and shifting cut sections of convex lenses, which are disposed on opposite sides of the convex lens.

13. A lighting device comprising:

a housing;

an LED array disposed in the housing; and

an optical lens disposed adjacent to the LED array comprising a substrate having a first pattern of Fresnel features disposed on a first side of the substrate, and a second pattern of Fresnel features disposed on a second side of the substrate opposite the first side,

wherein the first pattern of Fresnel features is perpendicular to and different from the second pattern of Fresnel features.

14. The lighting device of claim 13, wherein the first and second patterns of Fresnel features create a grid-like array of lenslets.

15. The lighting device of claim 14, wherein the LED array is a linear matrix of individual LEDs with equal spacing to and in alignment with the lenslets

16. The lighting device of claim 14, wherein the distance between the LED array and the optical lens ranges from 0.5 to 2.0 times the spacing distance between individual LEDs of the LED array.

17. The lighting device of claim 14, wherein the first pattern of Fresnel features has a first focal length and the second pattern of Fresnel features has a second focal length,

wherein the first focal length is different from the second focal lengths.

18. The lighting device of claim 15, wherein the size and number of lenslets of the optical lens correspond to and align with the size and number of individual LEDs disposed on the LED array.

19. The lighting device of claim 15, further comprising a distributed lens, wherein the distributed lens includes a plurality of lenses that extend from a base plate and receive the individual LEDs of the LED array.

20. The lighting device of claim 19, wherein the distributed lens is disposed adjacent the LED array such that an air gap is not formed between the distributed lens and the LED array.

21. The lighting device of claim 19, wherein the lenses of the distributed lens are curved in shape and have a diameter between 0.2 and 1.0 times the LED spacing of LEDs in the array.

22. A lighting device module comprising:

a housing module;

an LED array having an array of individual LEDs;

an optical lens; and

a distributed lens disposed between the LED array and the optical lens,

wherein the LED array, the optical lens and the distributed lens are self-contained within the housing module

23. The lighting device module of claim 22, wherein the optical lens has a first pattern of Fresnel features disposed on a first side of a substrate, and a second pattern of Fresnel features disposed on a second side of the substrate opposite the first side, wherein the second pattern of Fresnel features is perpendicular to and different from the first pattern of Fresnel features.

24. The lighting device module of claim 23, wherein the first pattern of Fresnel features has a first focal length and the second pattern of Fresnel features has a second focal length,

wherein the first focal length is different from the second focal length.

25. The lighting device module of claim 22, wherein the housing module includes a shelf and a plurality of retainer members such that the optical lens is disposed between the shelf and the retainer members to retain the optical lens within the housing module.

26. The lighting device module of claim 22, wherein the optical lens has at least one cut-out portion and wherein the housing module has at least one alignment tab, and wherein the alignment tab is configured to align with the cut-out portion upon insertion of the optical lens to the housing module.

27. The lighting device module of claim 22, wherein the LEDs are disposed on a printed circuit board (PCB) and wherein the printed circuit board is fastened to a wall of the housing module.

28. The lighting device module of claim 27, further comprising a conduit and an aperture formed in a sidewall of the housing module, wherein the conduit engages the aperture such that wires extend through the conduit and aperture for connection with the printed circuit board.

29. The lighting device module of claim 22, further comprising a housing cover having a plurality of snap members, wherein the snap members are configured to snap fit into engagement with a rim member of the housing module.

30. The lighting device module of claim 29, the housing cover has a plurality of protrusions extending from the surface of the cover, wherein a trim member of the lighting device is aligned relative to the housing cover by the plurality of protrusions.

31. The lighting device module of claim 22, wherein the distributed lens has a base plate and a plurality of hemispherical lenses, the hemispherical lenses extend from the base plate and receive respective individual LEDs of the LED array in a one-to-one correspondence.

32. The lighting device module of claim 31, wherein the distributed lens having at least one resilient engagement member, the resilient engagement member being insertable through the printed circuit board to a recess area of the housing module for snap fit engagement of the distributed lens within the housing module.