Proximity Sensor with Asymmetric Optical Element

• US 20130075595A1
• Filed: 09/23/2011
• Published: 03/28/2013
• Est. Priority Date: 09/23/2011
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Ruh, Richard
• Granted Patent: US 9,366,752 B2
• Time in Patent Office: Days
• US Class Current: 250/221
• CPC Class Codes: G01S 17/04 Systems determining the presence of a target
• CPC Class Codes: G01S 7/4814 of transmitters alone

Abstract

A proximity sensor may be mounted below a display cover layer in an electronic device. The proximity sensor may have a light source that emits light and a detector configured to detect reflections of the emitted light from nearby external objects. Optical structures may be interposed between the proximity sensor and the window in the display cover layer. The optical structures may include a first portion such as a convex lens that is configured to collimate light from the light source so that the light propagates along a surface normal to the display cover layer. The optical structures may also include a second portion such as a prism structure for deflecting uncollimated light away from the propagation axis of the collimated light.

Claims

1. Apparatus, comprising:

a light-based proximity sensor including a light source and a light detector; and

optical structures through which light from the light source passes, wherein the optical structures include light collimating structures and light deflecting structures.

2. The apparatus defined in claim 1 wherein the light collimating structures include lens structures that collimate the light from the light source to produce collimated light.

3. The apparatus defined in claim 2 wherein the collimated light propagates along a first axis and wherein the light deflecting structures are configured to deflect light from the light source to produce deflected light that propagates along a second axis that is oriented at a non-zero angle with respect to the first axis.

4. The apparatus defined in claim 3 wherein the optical structures are configured such that the deflected light comprises uncollimated light.

5. The apparatus defined in claim 4 wherein the light collimating structures comprise a convex lens.

6. The apparatus defined in claim 5 wherein the light deflecting structures comprise prism structures.

7. The apparatus defined in claim 6 wherein the convex lens and the prism structures are formed from a unitary molded plastic member.

8. The apparatus defined in claim 3 wherein the light source comprises an infrared light-emitting diode and wherein the light deflecting structures comprise prism structures.

9. The apparatus defined in claim 3 wherein the light collimating structures comprise a lens, wherein the light deflecting structures comprise a light reflector, and wherein the deflected light comprises uncollimated light.

10. The apparatus defined in claim 9 wherein the light reflector comprises a prism.

11. The apparatus defined in claim 1 wherein the wherein the light deflecting structures comprise a diffractive optical element.

12. Apparatus, comprising:

a light source;

a display cover layer that lies in a plane perpendicular to an axis;

first optical structures that refract light from the light source along the axis; and

second optical structures that reflect light from the light source away from the axis.

13. The apparatus defined in claim 12 further comprising display structures that are configured to display an image, wherein a first portion of the display cover layer covers the display structures and wherein a second portion of the display cover layer covers the first and second optical structures.

14. The apparatus defined in claim 13 wherein the first optical structures are configured to collimate the light from the light source to produce collimated light that passes through the second portion of the display cover layer and propagates parallel to the axis.

15. The apparatus defined in claim 14 wherein the second optical structures are configured to reflect the light from the light source to produce uncollimated light that passes through the second portion of the display cover layer and propagates at a non-zero angle with respect to the axis.

16. The apparatus defined in claim 12 wherein the light source comprises an infrared light-emitting diode, wherein the first optical structures comprise a convex lens that collimates light from the light source so that collimated light propagates along the axis, and wherein the second optical structures comprise prism structures that reflect the light from the light source to produce uncollimated light propagating at a non-zero angle with respect to the axis.

17. An electronic device, comprising:

a display layer;

a proximity sensor having a light source and a light detector;

a lens structure interposed between the light source and the display layer, wherein the lens structure is configured so that light emitted from the light source passes through the lens structure and the display layer and propagates along an axis; and

a light deflecting structure configured to deflect light from the light source in a direction away from the axis.

18. The electronic device defined in claim 17 wherein the light deflecting structures are configured to deflect the light from the light source to produce uncollimated light and wherein the display layer comprises a layer selected from the group consisting of:

a display cover glass layer and a plastic display cover layer.

19. The electronic device defined in claim 18 wherein the light source comprises a light-emitting diode.

20. The electronic device defined in claim 19 wherein the lens structure comprises a convex lens structure and wherein the light deflecting structure comprises prism.

21. The electronic device defined in claim 20 wherein the prism and the convex lens structure form portions of a common molded plastic structure and wherein the electronic device further comprises an infrared-transparent ink layer on the display layer through which collimated light from the convex lens structure and deflected uncollimated light from the prism pass.