Optical sensors that reduce specular reflections

• US 8,232,541 B2
• Filed: 07/08/2009
• Issued: 07/31/2012
• Est. Priority Date: 04/14/2009
• Status: Active Grant

• Current Assignee: Intersil Americas LLC (Renesas Electronics Corporation)
• Original Assignee: Intersil Americas LLC (Renesas Electronics Corporation)
• Inventors: Wiese, Lynn K., Kelkar, Nikhil, Patwardhan, Viraj
• Primary Examiner(s): LUU, THANH X
• Application Number:
  US12/499,723
• Publication Number:
  US 20100258712A1
• Time in Patent Office: 1,119 Days
• Field of Search: 250/551, 250/221, 250/239, 257 80- 82, 438/24, 438/25
• US Class Current: 250/551
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

An optical sensor device comprises a light source, a light detector, and an opaque light barrier including a first portion to block light from being transmitted directly from the source to the detector. A second portion of the light barrier extends from the first portion in a direction towards the light source, such that a portion of the second portion covers at least a portion of light emitting element(s) of the source, to reduce an amount of specular reflections, if a light transmissive cover plate were placed over the sensor. Additionally, a third portion of the barrier can extend from the first portion, in a direction towards to the detector, such that a portion of the third portion covers at least a portion of light detecting element(s) of the detector, to reduce an amount of specular reflections that would be detected by the detecting element(s) of the detector, if a light transmissive cover plate were placed over the sensor. Additionally, an off-centered lens can cover a portion of the light source.

Claims

1. An optical sensor device, comprising:

a light source including one or more light emitting elements;

a light detector including one or more light detecting elements;

a light transmissive material molded over and encapsulating the light source and the light detector;

an opaque light barrier including a first portion and a second portion that extends from the first portion;

wherein the first portion of the light barrier is between the light source and the light detector; and

wherein the second portion of the light barrier extends from the first portion of the light barrier a distance greater than an entire gap between the first portion of the light barrier and at least one of the one or more light emitting elements of the light source, in a direction towards the light source, such that a portion of the second portion of the light barrier extends over at least a portion of at least one of the one or more light emitting elements of the light source;

wherein the first portion of the light barrier separates a portion of the light transmissive material molded over and encapsulating the light source from a portion of the light transmissive material molded over and encapsulating the light detector;

wherein the second portion of the light barrier portion covers and is located on a portion of an outermost surface of the portion of the light transmissive material molded over and encapsulating the light source; and

wherein the second portion of the light barrier is configured to reduce an amount of specular reflections, if a light transmissive cover plate were placed over the optical sensor device.

2. The optical sensor device of claim 1, wherein the opaque light barrier is L-shaped.

3. The optical sensor of claim 1, wherein the first portion of the light barrier is configured to block light from being transmitted directly from the light source to the light detector.

4. The optical sensor device of claim 1, wherein the second portion of the light barrier is painted or otherwise deposited in a pattern onto the outermost surface of the portion of the light transmissive material molded over and encapsulating the light source, with portions of the pattern overlapping the outermost surface of the first portion of the light barrier.

5. The optical sensor device of claim 1,

wherein the opaque light barrier includes a third portion that extends from the first portion of the light barrier a distance greater than an entire gap between the first portion of the light barrier and the light detector, in a direction towards the light detector, such that a portion of the third portion of the light barrier extends over at least a portion of at least one of the one or more light detecting elements of the light detector;

wherein the third portion of the light barrier portion covers and is located on a portion of an outermost surface of the portion of the light transmissive material molded over and encapsulating the light detector; and

wherein the third portion of the light barrier is configured to reduce an amount of specular reflections that would be detected by the one or more light detecting elements of the light detector, if a light transmissive cover plate were placed over the optical sensor device.

6. The optical sensor device of claim 5, wherein the opaque light barrier is T-shaped.

7. The optical sensor of claim 5, wherein:

the first portion of the light barrier is configured to block light from being transmitted directly from the light source to the light detector.

8. The optical sensor device of claim 5, further comprising:

a lens covering at least a portion of the light source;

wherein the lens is off-centered relative to a center of the one or more light emitting elements of the light source, such that a center of the lens is offset in a direction away from the first portion of the opaque light barrier;

wherein the lens is laterally located relative to the second portion of the light barrier; and

wherein the lens is located on a portion of an outermost surface of the portion of the light transmissive material molded over and encapsulating the light source, or is part of the light transmissive material molded over and encapsulating the light source.

9. The optical sensor of claim 8, wherein the lens is configured to reduce an amount of specular reflections that would be detected by the light detector, if a light transmissive cover plate were placed over the optical sensor device.

10. The optical sensor of claim 8, wherein the lens comprises a convex lens.

11. An optical sensor device, comprising:

a light source including one or more light emitting elements;

a light detector including one or more light detecting elements;

a light transmissive material molded over and encapsulating the light source and the light detector;

an opaque light barrier including a first portion and a second portion; and

a lens covering at least a portion of the light source;

wherein the first portion of the light barrier is between the light source and the light detector and separates a portion of the light transmissive material molded over and encapsulating the light source from a portion of the light transmissive material molded over and encapsulating the light detector;

wherein the second portion of the light barrier extends from the first portion of the light barrier, in a direction towards the light source, such that a portion of the second portion of the light barrier covers at least a portion of at least one of the one or more light emitting elements of the light source;

wherein the second portion of the light barrier covers and is located on a portion of an outermost surface of the portion of the light transmissive material molded over and encapsulating the light source;

wherein the second portion of the light barrier reduces an amount of specular reflections if a light transmissive cover plate were placed over the optical sensor device;

wherein the lens is off-centered relative to a center of the one or more light emitting elements of the light source, such that a center of the lens is offset in a direction away from the first portion of the opaque light barrier;

wherein the lens is laterally located relative to the second portion of the light barrier; and

wherein the lens is located on a portion of an outermost surface of the portion of the light transmissive material molded over and encapsulating the light source, or is part of the light transmissive material molded over and encapsulating the light source.

12. The optical sensor of claim 11, wherein the lens is configured to reduce an amount of specular reflections that would be detected by the light detector, if a light transmissive cover plate were placed over the optical sensor device.

13. The optical sensor of claim 11, wherein the lens comprises a convex lens.

14. A method for providing an optical sensor device, comprising:

(a) attaching a light detector to a substrate and attaching a light source to the same substrate to which the light detector is attached, or to another substrate, so that there is a space between the light detector and the light source, wherein the light detector includes one or more light detecting elements, and the light source includes one or more light emitting elements;

(b) molding a light transmissive material over the light source and the light detector to thereby encapsulate the light source and the light detector with the light transmissive material;

(c) forming an opaque light barrier having a first portion and a second portion, so that the first portion of the opaque light barrier separates a portion of the light transmissive material molded over and encapsulating the light detector from a portion of the light transmissive material molded over and encapsulating the light source, so that the second portion of the light barrier is located on a portion of an outermost surface of the portion of the light transmissive material molded over and encapsulating the light source and extends from the first portion of the light barrier a distance greater than an entire gap between the first portion of the light barrier and at least one of the one or more light emitting elements of the light source, so that a portion of the second portion of the light barrier extends over at least a portion of at least one of the one or more light emitting elements of the light source.

15. The method of claim 14, wherein step (b) also includes forming a third portion of the opaque light barrier that extends from the first portion of the light barrier a distance greater than an entire gap between the first portion of the light barrier and the light detector, in a direction towards the light detector, so that the third portion of the light barrier is located on a portion of an outermost surface of the portion of the light transmissive material molded over and encapsulating the light detector, and so that a portion of the third portion of the light barrier extends over at least a portion of at least one of the one or more light detecting elements of the light detector.

16. The method of claim 15, further comprising:

(d) covering at least a portion of the light source with a lens that is off-centered relative to a center of the one or more light emitting elements of the light source and laterally located relative to the second portion of the light barrier, such that the center of the lens is offset in a direction away from the first portion of the opaque light barrier, and such that the lens is located on a portion of an outermost surface of the portion of the light transmissive material molded over and encapsulating the light source, or is part of the light transmissive material molded over and encapsulating the light source.

17. The method of claim 14, wherein step (c) includes forming the second portion of the opaque light barrier by painting or otherwise depositing an opaque material in a pattern onto the outermost surface of the portion of the light transmissive material molded over and encapsulating the light source, with portions of the pattern overlapping the outermost surface of the first portion of the light barrier.

18. A method for providing an optical sensor device, comprising:

(a) attaching a light detector to a substrate and attaching a light source to the same substrate to which the light detector is attached, or to another substrate, so that there is a space between the light detector and the light source, wherein the light detector includes one or more light detecting elements, and the light source includes one or more light emitting elements;

(b) molding a light transmissive material over the light source and the light detector to thereby encapsulate the light source and the light detector with the light transmissive material;

(c) forming an opaque light barrier having a first portion and a second portion, so that the first portion of the opaque light barrier separates a portion of the light transmissive material molded over and encapsulating the light detector from a portion of the light transmissive material molded over and encapsulating the light source, so that the second portion of the light barrier is located on a portion of an outermost surface of the portion of the light transmissive material molded over and encapsulating the light source, and so that a portion of the second portion of the light barrier covers at least a portion of at least one of the one or more light emitting elements of the light source; and

(d) covering at least a portion of the light source with a lens that is off-centered relative to a center of the one or more light emitting elements of the light source and laterally located relative to the second portion of the light barrier, such that the center of the lens is offset in a direction away from the first portion of the opaque light barrier, and such that the lens is located on a portion of an outermost surface of the portion of the light transmissive material molded over and encapsulating the light source, or is part of the light transmissive material molded over and encapsulating the light source.

19. A method for use with a light sensor device include a light detector and a light source spaced apart from one another, wherein the light source includes one or more light emitting elements, the method comprising:

(a) molding a light transmissive material over the light source and the light detector to thereby encapsulate the light source and the light detector with the light transmissive material;

(b) providing a first portion of an opaque light barrier so that the first portion separates a portion of the light transmissive material molded over and encapsulating the light detector from a portion of the light transmissive material molded over and encapsulating the light source; and

(c) providing a second portion of the opaque light barrier, which extends from the first portion of the light barrier in a direction toward the light source a distance greater than an entire gap between the first portion of the light barrier and at least one of the one or more light emitting elements of the light source, so that the second portion of the opaque barrier is located on a portion of an outermost surface of the portion of the light transmissive material molded over and encapsulating the light source, and so that a portion of the second portion of the opaque light barrier extends over at least a portion of at least one of the one or more light emitting elements of the light source.

20. The method of claim 19, further comprising:

(d) providing a third portion of the opaque light barrier, which extends from the first portion of the light barrier a distance greater than an entire gap between the first portion of the light barrier and the light detector in a direction towards the light detector, so that the third portion of the light barrier is located on a portion of an outermost surface of the portion of the light transmissive material molded over and encapsulating the light detector, and so that a portion of the third portion of the light barrier extends over at least a portion of the light detector.

21. The method of claim 20, further comprising:

(e) covering at least a portion of the light source with a lens that is off-centered relative to a center of the light source and laterally located relative to the second portion of the opaque light barrier, such that a center of the lens is offset in a direction away from the first portion of the opaque light barrier, and such that the lens is located on a portion of an outermost surface of the portion of the light transmissive material molded over and encapsulating the light source, or is part of the light transmissive material molded over and encapsulating the light source.

22. The method of claim 19, wherein step (c) includes forming the second portion of the opaque light barrier by painting or otherwise depositing an opaque material in a pattern onto the outermost surface of the portion of the light transmissive material molded over and encapsulating the light source, with portions of the pattern overlapping the outermost surface of the first portion of the light barrier.

23. A method for use with a light sensor device including a light detector and a light source spaced apart from one another, comprising:

(a) molding a light transmissive material over the light source and the light detector to thereby encapsulate the light source and the light detector with the light transmissive material;

(b) providing a first portion of an opaque light barrier so that the first portion separates a portion of the light transmissive material molded over and encapsulating the light detector from a portion of the light transmissive material molded over and encapsulating the light source;

(c) providing a second portion of the opaque light barrier, which extends from the first portion of the light barrier in a direction toward the light source, so that the second portion of the opaque barrier is located on a portion of an outermost surface of the portion of the light transmissive material molded over and encapsulating the light source, and so that a portion of the second portion of the opaque light barrier covers at least a portion of the light source; and

(d) covering at least a portion of the light source with a lens that is off-centered relative to a center of the light source and laterally located relative to the second portion of the opaque light barrier, such that a center of the lens is offset in a direction away from the first portion of the opaque light barrier, and such that the lens is located on a portion of an outermost surface of the portion of the light transmissive material molded over and encapsulating the light source, or is part of the light transmissive material molded over and encapsulating the light source.

24. A system, comprising:

an optical sensor;

a driver to selectively drive one or more light emitting elements of the optical sensor;

a processor and/or circuitry to detect proximity of an object, if any, relative to the optical sensor; and

a subsystem that is responsive to proximity of an object, if any, relative to the optical sensor, as detected by the processor and/or circuitry;

wherein the optical sensor includes

a light source including one or more light emitting elements;

a light detector;

an opaque light barrier including a first portion and a second portion that extends from the first portion;

wherein the first portion of the light barrier is between the light source and the light detector; and

wherein the second portion of the light barrier extends from the first portion of the light barrier a distance greater than an entire gap between the first portion of the light barrier and at least one of the one or more light emitting elements of the light source, in a direction towards the light source, such that a portion of the second portion of the light barrier extends over a portion of at least one of the one or more light emitting elements of the light source;

wherein the first portion of the light barrier separates a portion of the light transmissive material molded over and encapsulating the light source from a portion of the light transmissive material molded over and encapsulating the light detector;

wherein the second portion of the light barrier portion covers and is located on a portion of an outermost surface of the portion of the light transmissive material molded over and encapsulating the light source; and

wherein the second portion of the light barrier is configured to reduce an amount of specular reflections, if a light transmissive cover plate were placed over the optical sensor device.

25. The system of claim 24, further comprising:

a lens covering at least a portion of the light source,

wherein the lens is off-centered relative to a center of the light source, such that a center of the lens is offset in a direction away from the first portion of the opaque light barrier;

wherein the lens is laterally located relative to the second portion of the light barrier; and

wherein the lens is located on a portion of an outermost surface of the portion of the light transmissive material molded over and encapsulating the light source, or is part of the light transmissive material molded over and encapsulating the light source.

26. The system of claim 24, wherein the opaque light barrier includes a third portion that extends from the first portion of the light barrier a distance greater than an entire gap between the first portion of the light barrier and the light detector, in a direction towards to the light detector, so that the third portion of the light barrier is located on a portion of an outermost surface of the portion of the light transmissive material molded over and encapsulating the light detector, and so that a portion of the third portion of the light barrier extends over at least a portion of an active area of the light detector.

27. The system of claim 24, wherein the second portion of the light barrier is-painted or otherwise deposited in a pattern onto the outermost surface of the portion of the light transmissive material molded over and encapsulating the light source, with portions of the pattern overlapping the outermost surface of the first portion of the light barrier.

28. An optical sensor device, comprising:

a light source including one or more light emitting elements;

a light detector including one or more light detecting elements;

a light transmissive material molded over and encapsulating the light source and the light detector;

an opaque light barrier including a first portion and a second portion that extends from the first portion;

wherein the first portion of the light barrier is between the light source and the light detector; and

wherein the second portion of the light barrier extends from the first portion of the light barrier, in a direction towards the light source, such that a line normal to a light emitting surface of at least one of the one or more light emitting elements of the light source intersects the second portion of the light barrier;

wherein the first portion of the light barrier separates a portion of the light transmissive material molded over and encapsulating the light source from a portion of the light transmissive material molded over and encapsulating the light detector;

wherein the second portion of the light barrier portion covers and is located on a portion of an outermost surface of the portion of the light transmissive material molded over and encapsulating the light source; and

wherein the second portion of the light barrier is configured to reduce an amount of specular reflections, if a light transmissive cover plate were placed over the optical sensor device.

29. The optical sensor device of claim 28,

wherein the opaque light barrier includes a third portion that extends from the first portion of the light barrier, in a direction towards the light detector, such that a line normal to a light detecting surface of the light detector intersects the third portion of the light barrier;

wherein the third portion of the light barrier portion covers and is located on a portion of an outermost surface of the portion of the light transmissive material molded over and encapsulating the light detector; and

wherein the third portion of the light barrier is configured to reduce an amount of specular reflections that would be detected by the one or more light detecting elements of the light detector, if a light transmissive cover plate were placed over the optical sensor device.