Fresnel lens barrier rings

• US 10,054,720 B2
• Filed: 06/29/2015
• Issued: 08/21/2018
• Est. Priority Date: 02/02/2015
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Block, Ueyn L., Harrison-Noonan, Tobias J., Nazzaro, David
• Primary Examiner(s): Pasko, Nicholas R
• Application Number:
  US14/754,557
• Publication Number:
  US 20160223720A1
• Time in Patent Office: 1,149 Days
• Field of Search: 359573, 359574, 359575, 359742
• CPC Class Codes: G02B 3/08 with discontinuous faces, e.g. Fresnel lens diffractive Fresnel lenses G02B5/1876
• CPC Class Codes: G02B 5/1876 Diffractive Fresnel lenses; Zone plates; Kinoforms G02B5/1842, G02B5/1847 take precedence; optical systems having diffractive correction means G02B27/0037; Fresnel lenses operating by refraction G02B3/08

Abstract

A Fresnel lens can be adhered to a window in an optical apparatus by liquid optically clear adhesive (LOCA). However, during adhesion the LOCA may spill over into grooves of the Fresnel lens, and the grooves can carry the LOCA into an active area of the lens potentially causing visual artifacts and altering the functional and cosmetic optical qualities of the lens. In examples of the disclosure, one or more grooves along the circumference of a surface of the lens surrounding inner grooves of the Fresnel lens can form a barrier ring that prevents the LOCA from reaching the inner grooves.

Claims

1. A lens having a surface with a circumference, the lens comprising:

a first set of one or more semi-circular grooves in the surface that are not concentric with the circumference of the surface; and

a second set of one or more grooves in the surface that are concentric with the circumference of the surface and that surround the first set of grooves, wherein an end of at least one groove of the first set of grooves intersects with at least one groove of the second set of grooves.

2. The lens of claim 1, wherein the lens is adhered, on an additional surface of the lens opposite the surface that includes the first and second sets of grooves, to a window.

3. The lens of claim 1, wherein the first set includes a first groove having a first cross-sectional shape, and the second set includes a second groove having a second cross-sectional shape different from the first cross-sectional shape.

4. The lens of claim 2, wherein the lens is adhered via a liquid adhesive, and the liquid adhesive is present in at least an outermost groove of the second set of grooves.

5. The lens of claim 3, wherein the first groove is tapered such that it narrows to a v-shaped corner at a deepest portion of the first groove and the second groove includes a flat surface at a deepest portion of the second groove.

6. The lens of claim 3, wherein the second groove is narrower at a surface portion of the second groove than at a portion of the second groove that is deeper than the surface portion.

7. The lens of claim 3, wherein the second groove is deeper than the first groove.

8. The lens of claim 3, wherein the second groove is wider than the first groove.

9. The lens of claim 3, wherein a volume of a cavity formed by the second groove is greater than a volume of a cavity formed by the first groove.

10. The lens of claim 3, wherein the first groove includes two sides that meet at a deepest portion of the first groove, the first groove includes no more than two sides, and the second groove includes more than two sides, including a flat surface at a deepest portion of the second groove.

11. A lens having a surface with a circumference, the lens comprising:

a first set of one or more semi-circular grooves in the surface that are not concentric with the circumference of the surface; and

a second set of one or more grooves in the surface that define an annular portion of the surface surrounding the first set of grooves, wherein an end of at least one groove of the first set of grooves intersects with at least one groove of the second set of grooves,

wherein the grooves of the second set spiral inwards, forming a barrier ring surrounding the first set of grooves.

12. The lens of claim 11, wherein the grooves of the second set are offset with respect to the circumference of the surface such that the grooves of the second set are non-concentric with the circumference, forming form a barrier ring surrounding the first set of grooves.

13. The lens of claim 11, wherein the grooves of the second set form a non-circular path along the annular portion of the surface surrounding the first set of grooves.

14. The lens of claim 11, wherein the first set includes a first groove having a first cross-sectional shape, and the second set includes a second groove having a second cross-sectional shape different from the first cross-sectional shape.

15. The lens of claim 11, wherein the lens is adhered, on an additional surface of the lens opposite the surface that includes the first and second sets of grooves, to a window.

16. The lens of claim 15, wherein the lens is adhered via a liquid adhesive, and the liquid adhesive is present in at least an outermost groove of the second set of grooves.