Passively Athermalized Infrared Imaging System And Method Of Manufacturing Same

• US 20120188634A1
• Filed: 01/20/2012
• Published: 07/26/2012
• Est. Priority Date: 01/20/2011
• Status: Active Grant

• Current Assignee: Snap, Inc.
• Original Assignee: Snap, Inc.
• Inventors: Kubala, Kenneth Scott, Baron, Alan E., Bates, Robert Matthew
• Granted Patent: US 9,448,338 B2
• Time in Patent Office: Days
• US Class Current: 359/356
• CPC Class Codes: G02B 3/0062 Stacked lens arrays, i.e. refractive surfaces arranged in at least two planes, without structurally separate optical elements in-between
• CPC Class Codes: G02B 7/003 Alignment of optical elements G02B7/001, G02B7/002 take precedence; for mirrors G02B7/1822
• CPC Class Codes: Y10T 156/1052 with cutting, punching, tearing or severing
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

In an embodiment, a method of aligning elements in a manufacturing process includes placing a middle element onto a base element, the base element forming first alignment features, the middle element forming apertures therethrough corresponding to the first alignment features. The method also includes placing second alignment features of an upper element onto the first alignment features such that the first and second alignment features cooperate, through the apertures, to align the upper element with the base element. An infrared lens assembly includes a lens formed of an infrared transmitting material that is disposed within a carrier of a base material, the lens being molded within the carrier with at least one feature that secures the lens to the carrier.

Claims

1. A method of aligning elements in a manufacturing process, comprising

placing a middle element onto a base element, the base element forming first alignment features, the middle element forming apertures therethrough corresponding to the first alignment features;

and

placing second alignment features of an upper element onto the first alignment features such that the first and second alignment features cooperate, through the apertures, to align the upper element with the base element.

2. The method of claim 1 wherein the steps of placing the middle element and the second alignment features align the middle element to the base element and the upper element with a tolerance corresponding to a clearance of the apertures around the first and second alignment features.

3. The method of claim 1, further comprising

bonding the base, middle and upper elements together while the alignment features cooperate, to form a composite element;

and

dicing the composite element to generate a plurality of subunits that do not include any portion of the first or second alignment features, but in which respective portions of the base and upper elements remain in alignment.

4. The method of claim 3 wherein bonding comprises utilizing an adhesive.

5. A method of aligning elements in a manufacturing process, comprising

placing a middle element onto a base element, the base element forming first alignment features, the middle element forming apertures therethrough corresponding to the first alignment features;

placing intermediate alignment elements upon the first alignment features; and

placing second alignment features of an upper element onto the intermediate alignment features such that the first, intermediate, and second alignment features cooperate to align the upper element with the base element.

6. The method of claim 5 wherein placing the intermediate alignment elements comprises placing substantially spherical elements into recesses in the base element that form the first alignment elements.

7. The method of claim 5 wherein the steps of placing the middle element, the intermediate alignment elements and the second alignment features align the middle element to the base element and the upper element with a tolerance corresponding to a clearance of the apertures around the intermediate alignment elements.

8. A plurality of infrared lens systems, comprising:

at least one first lens wafer comprising a first base material that is opaque to infrared radiation, with infrared transmissive material inset into apertures therein to form first lenses;

bonded with at least one second lens wafer having a plurality of second lenses, such that pluralities of the first and second lenses align to form the lens systems.

9. The infrared lens systems of claim 8, wherein the infrared transmissive material is inset into carriers that are inset into the first base material.

10. The infrared lens systems of claim 8, wherein the first base material transmits at least one of visible and ultraviolet radiation.

11. The infrared lens systems of claim 8, the second lens wafer comprising a second base material that is opaque to infrared radiation, with infrared transmissive material inset into apertures therein to form the second lenses.

12. The infrared lens systems of claim 11, wherein the first base material transmits at least one of visible and ultraviolet radiation.

13. The infrared lens systems of claim 8, the first base material comprising one of metal, plastic, ceramic and composite.

14. The infrared lens systems of claim 8, wherein the first and second wafers are joined to one another.

15. The infrared lens systems of claim 14, the first and second lens wafers being mechanically joined.

16. The infrared lens systems of claim 14, the first and second lens wafers being joined with an adhesive.

17. The infrared lens systems of claim 8, wherein the first and second lens wafers are diced to separate each of the lens systems from one another.

18. The infrared lens systems of claim 17, wherein after dicing, the lens systems do not include alignment features utilized to align the first and second lens wafers.

19. The infrared lens systems of claim 18, further comprising a sensor aligned to at least one of the lens systems.

20. The infrared lens systems of claim 19 wherein the sensor is hermetically sealed to the at least one of the lens systems.

21. The infrared lens systems of claim 8, further comprising a plurality of spacers, each of the spacers being disposed between and bonded with one of the first lenses and one of the second lenses, each of the spacers forming an aperture along an optical axis formed by the ones of the first and second lenses.

22. The infrared lens systems of claim 8, further comprising a spacer layer forming a plurality of apertures between each of the first and second lenses, the spacer layer being disposed between and bonded with the first and second lens wafers.

23. The infrared lens systems of claim 22, the spacer layer being opaque to infrared energy.

24. The infrared lens systems of claim 23, the spacer layer comprising one of metal, plastic, ceramic and composite.

25. The infrared lens systems of claim 8, further comprising a sensor array layer comprising a plurality of sensors, each sensor aligning to a corresponding one of the lens systems.

26. The infrared lens systems of claim 25 wherein each of the sensors is hermetically sealed with the corresponding one of the lens systems.

27. The infrared lens systems of claim 26 wherein each of the sensors is hermetically sealed with the corresponding one of the lens systems without a cover plate over the sensor array.

28. A lens wafer for use in optical manufacturing, comprising:

a substrate forming apertures therein, the substrate being formed of a base material; and

a plurality of lenses, each of the lenses comprising an optical material and disposed within a respective one of the apertures.

29. The lens wafer of claim 28, the base material comprising one of metal, plastic, ceramic and composite.

30. The lens wafer of claim 28, each of the plurality of lenses being at least 200 microns from each other of the plurality of lenses such that the substrate can be diced to singulate portions of the substrate having a single lens therein without damaging any of the plurality of lenses.

31. The lens wafer of claim 28, the optical material being transparent to IR radiation.

32. The lens wafer of claim 31, the optical material comprising one or more of a chalcogenide glass, a crystalline material, a salt, plastic or glass.

33. The lens wafer of claim 28, further comprising mechanical alignment features therein for alignment of the lens wafer to a second lens wafer.

34. The lens wafer of claim 28, each of the lenses being disposed within its respective aperture in a nonfinal form, and being subsequently shaped to a final form while in the aperture.

35. The lens wafer of claim 34, each of the lenses being shaped to the final form by one of polishing, grinding, diamond turning, magnetorheological finishing, compression molding or injection molding.

36. The lens wafer of claim 28, each of the plurality of lenses forming an outwardly facing flange, the substrate comprising plastic that is overmolded about each of the flanges.

37. The lens wafer of claim 36, each of the outwardly facing flanges forming an alignment feature that cooperates with a mold, to align each respective lens within the lens wafer as the plastic is overmolded about each of the flanges using the mold.

38. The lens wafer of claim 36, the substrate comprising alignment features for subsequent alignment of the substrate, the alignment features being formed as the plastic is overmolded about each of the flanges using the mold.

39. The lens wafer of claim 28, each of the plurality of lenses being held by a respective lens carrier.

40. The lens wafer of claim 39, the lens carriers being held within respective apertures of the substrate with an adhesive.

41. The lens wafer of claim 39, each of the lens carriers comprising one or more of metal, plastic and ceramic.

42. The lens wafer of claim 39, each of the lens carriers comprising alignment features for alignment of the lens carriers with the lens wafer.

43. An infrared lens assembly, comprising:

a lens formed of an infrared transmitting material that is disposed within a carrier of a base material, the lens being molded within the carrier with at least one feature that secures the lens to the carrier.

44. The infrared lens assembly of claim 43, the lens comprising one or more of a chalcogenide glass, plastic, glass, a crystalline material, and a salt.

45. The infrared lens assembly of claim 43, the carrier forming one of a recess and a protrusion that engage the at least one feature of the lens.

46. The infrared lens assembly of claim 43, the carrier forming at least one alignment feature for aligning the carrier to another carrier.

47. The infrared lens assembly of claim 43, the base material comprising plastic.

49. The infrared lens assembly of claim 43, the feature comprising an annular groove.

48. The infrared lens assembly of claim 48, wherein the plastic transmits visible radiation and is opaque to infrared radiation.

50. A mold set, comprising:

an upper mold and a lower mold,

at least one of the upper and lower molds having one or more features that are configured to hold an infrared lens in an aligned position, the upper and lower molds configured to provide a cavity for molding a moldable material into one of a lens carrier and a lens wafer about the infrared lens.

51. The mold set of claim 50, at least one of the upper and lower molds comprising a dam for preventing the moldable material from obscuring an optical surface of the infrared lens.

52. An infrared lens assembly, comprising:

a lens formed of an infrared transmitting material that is disposed within a carrier of a base material, the carrier being molded around the lens with at least one feature that secures the lens to the carrier.

53. An infrared lens stack, comprising:

a first lens formed of an infrared transmitting material and disposed within a first carrier, formed of a base material, that forms at least one first alignment feature; and

a second lens formed of an infrared transmitting material and disposed within a second carrier, formed of a base material, that forms at least one second alignment feature configured to cooperate with the first alignment feature;

wherein the stack is formed by placing the first assembly atop the second assembly so that the alignment features cooperate.

54. The infrared lens stack of claim 53, wherein the carriers are bonded together.

55. The infrared lens stack of claim 53, wherein the base material of the first or second carriers comprises plastic.

56. The infrared lens stack of claim 55, wherein the plastic transmits at least one of visible and ultraviolet radiation but is opaque to infrared radiation.