METHOD AND APPARATUS PROVIDING SINGLET WAFER LENS SYSTEM WITH FIELD FLATTENER

• US 20100002313A1
• Filed: 07/02/2008
• Published: 01/07/2010
• Est. Priority Date: 07/02/2008
• Status: Active Grant

• Current Assignee: Aptina Imaging Corporation (ON Semiconductor Corporation)
• Original Assignee: Aptina Imaging Corporation (ON Semiconductor Corporation)
• Inventors: Oliver, Steven D., Duparre, Jacques
• Granted Patent: US 7,920,339 B2
• Time in Patent Office: Days
• US Class Current: 359/742
• CPC Class Codes: G02B 13/001 Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras G02B23/243 takes precedence
• CPC Class Codes: G02B 13/0025 having one lens only
• CPC Class Codes: G02B 13/0055 employing a special optical element
• CPC Class Codes: G02B 13/006 at least one element being a compound optical element, e.g. cemented elements
• CPC Class Codes: G02B 13/0085 employing wafer level optics
• CPC Class Codes: G02B 27/0025 for optical correction, e.g. distorsion, aberration
• CPC Class Codes: G02B 3/08 with discontinuous faces, e.g. Fresnel lens diffractive Fresnel lenses G02B5/1876
• CPC Class Codes: G02B 9/12 having three components only
• CPC Class Codes: G02B 9/34 having four components only
• CPC Class Codes: Y10T 156/1039 Surface deformation only of sandwich or lamina [e.g., embossed panels]

Abstract

Methods and apparatus to correct a curved Petzval focusing surface to a plane using a convex lens, a concave lens, and a space arranged between the curved side of the convex lens and the curved side of the concave lens. The method and apparatus may also include a Fresnel lens arranged between the concave lens and a pixel array.

Claims

1. A lens structure, comprising:

a first convex lens comprising a first curved side and a first flat side; and

a concave lens comprising a second curved side and a second flat side, the second curved side of the concave lens being arranged to face the first curved side of the first convex lens; and

a first space arranged between the first curved side of the first convex lens and the second curved side of the concave lens.

2. The lens structure of claim 1, further comprising a Fresnel lens comprising a third flat side and a side comprising a faceted structure, the third flat side of the Fresnel lens being arranged to face the second flat side of the concave lens.

3. The lens structure of claim 1, further comprising a second convex lens comprising a fourth curved side and a fourth flat side, the fourth flat side of the second convex lens being arranged to face the first flat side of the first convex lens;

4. The lens structure of claim 1, wherein the first space is filled with air.

5. The lens structure of claim 1, wherein the first convex lens and the concave lens have indices of refraction greater than that of the first space.

6. The lens structure of claim 3, further comprising an aperture arranged between the first convex lens and the second convex lens.

7. The lens structure of claim 3, further comprising an infrared filter arranged between the first convex lens and the second convex lens.

8. The lens structure of claim 3, further comprising a first substrate arranged between the first convex lens and the second convex lens.

9. The lens structure of claim 8, further comprising a second substrate arranged between the first substrate and the second convex lens.

10. The lens structure of claim 2, further comprising a third substrate arranged between the concave lens and the Fresnel lens.

11. The lens structure of claim 2, wherein the first convex lens, concave lens, and Fresnel lens have substantially the same index of refraction.

12. The lens structure of claim 2, wherein the first convex lens, concave lens, and Fresnel lens comprise a polymer material.

13. The lens structure of claim 2, wherein the faceted structure of the Fresnel lens comprises a plurality of concentric facets, each of the facets having a first side and a second side.

14. The lens structure of claim 13, wherein facets located closer to a center of the faceted structure are wider than facets located farther from the center of the faceted structure.

15. The lens structure of claim 14, wherein all of the facets have the same depth.

16. The lens structure of claim 13, wherein facets located farther from a center of the faceted structure are deeper than facets located closer to the center of the faceted structure.

17. The lens structure of claim 16, wherein all of the facets have the same period.

18. The lens structure of claim 13, wherein the first side of the facets is arranged to be perpendicular to a light ray having a chief ray angle able to reach a particular facet.

19. The lens structure of claim 13, wherein the second side of the facets is arranged to be parallel to a light ray having a chief ray angle still able to reach a particular facet.

20. The lens structure of claim 13, wherein the first side of the facets comprise a convex curve.

21. An imaging device comprising:

a pixel array for capturing an image, the pixel array being arranged on a first substrate; and

a lens structure for focusing the image onto the pixel array,

the lens structure comprising;

a first convex lens comprising a first curved side and a first flat side;

a second convex lens comprising a second curved side and a second flat side, the second flat side of the second convex lens being arranged to face the first flat side of the first convex lens; and

a field flattener lens comprising a concave side and a third flat side, the third curved side of the concave lens being arranged to face the second curved side of the second convex lens.

22. The imaging device of claim 21, further comprising a Fresnel lens comprising a fourth flat side and a side comprising a faceted structure, the fourth flat side of the Fresnel lens being arranged to face the third flat side of the concave lens and the faceted structure being arranged to face the pixel array.

23. The imaging device of claim 22, further comprising a first space arranged between the second curved side of the second convex lens and the concave side of the field flattener lens.

24. The imaging device of claim 23, further comprising a second space arranged between the Fresnel lens and the pixel array.

25. The imaging device of claim 24, wherein the first space and the second space are filled with air.

26. The imaging device of claim 24, wherein the first convex lens, second convex lens, field flattener lens, and Fresnel lens have indices of refraction greater than that of the first space and the second space.

27. The imaging device of claim 22, wherein the faceted structure of the Fresnel lens comprises a plurality of concentric facets, each of the facets having a first side and a second side.

28. The imaging device of claim 27, wherein facets located closer to a center of the faceted structure are wider than facets located farther from the center of the faceted structure and wherein all of the facets have the same depth.

29. The imaging device of claim 27, wherein facets located farther from a center of the faceted structure are deeper than facets located closer to the center of the faceted structure and wherein all of the facets have the same period.

30. The imaging device of claim 27, wherein the first side of the facets is arranged to be perpendicular to a ray bundle having a chief ray angle able to reach a particular facet.

31. The imaging device of claim 27, wherein the second side of the facets is arranged to be parallel to a ray bundle having a chief ray angle able to reach a particular facet.

32. The imaging device of claim 22, wherein the imaging device is part of an imaging system.

33. The imaging device of claim 32, wherein the imaging system is a digital camera.

34. A method of making an imaging device comprising:

forming a first convex lens comprising a first curved side and a first flat side;

forming a second convex lens comprising a second curved side and a second flat side and arranging the second convex lens so that the second flat side of the second convex lens faces the first flat side of the first convex lens;

forming a concave lens comprising a third curved side and a third flat side, and arranging the concave lens so that the third curved side of the concave lens faces the second curved side of the second convex lens;

forming a Fresnel lens comprising a fourth flat side and a side comprising a faceted structure and arranging the Fresnel lens so that the fourth flat side of the Fresnel lens faces the third flat side of the concave lens; and

forming a pixel array on a first substrate and arranging the first substrate so that the pixel array faces the faceted structure of the Fresnel lens.

35. The method of claim 34, further comprising forming the Fresnel lens by imprinting replication of polymers.

36. The method of claim 34, further comprising forming the Fresnel lens on a second substrate and coupling the second substrate to the first substrate.

37. The method of claim 34, further comprising forming the first convex lens on a third substrate, forming the second convex lens on a fourth substrate, and coupling the third substrate to the fourth substrate.

38. The method of claim 37, further comprising forming an aperture between the third substrate and the fourth substrate.

39. The method of claim 37, further comprising coupling the second convex lens to the concave lens.