Light Sensors For Electronic Devices

• US 20140167619A1
• Filed: 12/17/2012
• Published: 06/19/2014
• Est. Priority Date: 12/17/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Land, Brian R., Hotelling, Steven P.
• Granted Patent: US 9,046,421 B2
• Time in Patent Office: Days
• US Class Current: 315/152
• CPC Class Codes: G01J 1/0219 Electrical interface; User interface
• CPC Class Codes: G01J 1/0228 Control of working procedures; Failure detection; Spectral bandwidth calculation
• CPC Class Codes: G01J 1/0233 Handheld
• CPC Class Codes: G01J 1/0271 Housings; Attachments or accessories for photometers
• CPC Class Codes: G01J 1/0437 using masks, aperture plates, spatial light modulators, spatial filters, e.g. reflective filters
• CPC Class Codes: G01J 1/0488 with spectral filtering
• CPC Class Codes: G01J 1/4204 with determination of ambient light solar light G01J2001/4266
• CPC Class Codes: G01J 1/4228 arrangements with two or more detectors, e.g. for sensitivity compensation
• CPC Class Codes: G01J 1/44 Electric circuits for command of an exposure part G03B7/02
• CPC Class Codes: G01S 17/04 Systems determining the presence of a target
• CPC Class Codes: G01S 7/4811 common to transmitter and receiver
• CPC Class Codes: G01S 7/4813 Housing arrangements

Abstract

Electronic devices may include light sensors. A light sensor may be an ambient light sensor that is mounted adjacent to an aperture in an opaque structure. An ambient light sensor may include active light sensor elements located adjacent to the aperture and inactive light sensor elements located adjacent to the opaque structure. Signal processing circuitry may be interposed between the light sensor elements and a summing circuit that sums light signals from the light sensor elements to form an ambient light signal. The signal processing circuitry may include a switch and an amplifier associated with each light sensor element. The switch associated with each element may be used to selectively activate or inactivate that element. The amplifier associated with each element may be used to amplify the light signal from that element by a gain factor that depends on the location of that element with respect to the aperture.

Claims

1. An electronic device, comprising:

an enclosure having at least one opaque portion;

an aperture in the opaque portion; and

a light sensor mounted to the enclosure, wherein the light sensor includes a first portion that receives light through the aperture, a second portion that is prevented from receiving light by the opaque portion, active light sensor elements in the first portion, and inactive light sensor elements in the second portion.

2. The electronic device defined in claim 1, further comprising:

signal processing circuitry; and

a summing circuit, wherein the signal processing circuitry comprises circuitry that is interposed between each active light sensor element and the summing circuit and additional circuitry that is interposed between each inactive light sensor element and the summing circuit.

3. The electronic device defined in claim 2 wherein the circuitry that is interposed between each active light sensor element and the summing circuit comprises a plurality of enabled switches, wherein each of the enabled switches is coupled between a selected one of the active light sensor elements and the summing circuit.

4. The electronic device defined in claim 3 wherein the additional circuitry that is interposed between each inactive light sensor element and the summing circuit comprises a plurality of disabled switches, wherein each of the disabled switches is coupled between a selected one of the inactive light sensor elements and the summing circuit.

5. The electronic device defined in claim 1 wherein the aperture has a lateral size and wherein the light sensor comprises a substrate having a lateral size that is larger than the lateral size of the aperture.

6. The electronic device defined in claim 5 wherein the second portion of the light sensor that is prevented from receiving light by the opaque portion comprises a portion of the substrate that extends beyond an edge of the aperture.

7. The electronic device defined in claim 1 wherein the enclosure comprises an opaque housing structure and wherein the aperture comprises an opening in the opaque housing structure.

8. The electronic device defined in claim 1, further comprising a display, wherein the enclosure comprises a cover layer for the display.

9. The electronic device defined in claim 8 wherein the cover layer comprises a transparent material and wherein the opaque portion of the enclosure comprises a portion of the transparent material that is covered by an opaque masking layer.

10. An electronic device, comprising:

an enclosure having at least one opaque portion;

an aperture in the opaque portion that allows at least some light to pass through the aperture; and

a light sensor mounted adjacent to the aperture in the opaque portion, wherein the light sensor comprises a plurality of light sensor elements and a plurality of corresponding amplifiers, wherein each amplifier is coupled to a selected one of the plurality of light sensor elements, wherein each amplifier amplifies light signals from the selected one of the light sensor elements using a gain factor for that light sensor element, and wherein the gain factor for each light sensor element is based on a location of that light sensor element on the light sensor.

11. The electronic device defined in claim 10, further comprising a summing circuit coupled to each of the plurality of corresponding amplifiers.

12. The electronic device defined in claim 11 wherein the aperture has a center and wherein the gain factor for each light sensor element is proportional to a distance between the location of that light sensor element and the center of the aperture.

13. The electronic device defined in claim 10 wherein the light sensor further comprises at least one inactive light sensor element.

14. The electronic device defined in claim 10 wherein the plurality of light sensor elements comprise a plurality of concentric circular light sensor elements each having an effective radius and wherein the gain factor for each concentric circular light sensor element is based on the effective radius of that concentric circular light sensor element.

15. An electronic device, comprising:

a transparent substrate;

an opaque masking layer on the transparent substrate;

an opening in the opaque masking layer; and

a light sensor attached to the transparent substrate, wherein the light sensor includes a first plurality of light sensor elements located adjacent to the opening and a second plurality of light sensor elements located adjacent to the opaque masking layer.

16. The electronic device defined in claim 15 wherein the first plurality of light sensor elements are active light sensor elements and wherein the second plurality of light sensor elements are inactive light sensor elements.

17. The electronic device defined in claim 16, further comprising:

a plurality of amplifiers; and

a summing circuit, wherein each amplifier is interposed between a selected one of the active light sensor elements and the summing circuit.

18. The electronic device defined in claim 17 wherein each amplifier is configured to amplify a light signal from an associated active light sensor based on the location of that active light sensor.

19. The electronic device defined in claim 18 wherein each amplifier is configured to amplify the light signal from the associated active light sensor based on a distance between that active light sensor and a center point of the opening.

20. The electronic device defined in claim 16, further comprising a display, wherein the transparent substrate comprises a cover layer for the display.

21. The electronic device defined in claim 20 wherein the transparent substrate comprises glass.