Integrated ambient light sensor and distance sensor

• US 8,705,015 B2
• Filed: 02/27/2012
• Issued: 04/22/2014
• Est. Priority Date: 07/25/2007
• Status: Expired due to Fees

• Current Assignee: Eminence Electronic Technology Pvt. Ltd.
• Original Assignee: Eminence Electronic Technology Pvt. Ltd.
• Inventors: Chang, Tom, Canfield, John
• Primary Examiner(s): RATCLIFFE, LUKE D
• Application Number:
  US13/406,086
• Publication Number:
  US 20120153153A1
• Time in Patent Office: 785 Days
• Field of Search: 356 301- 315, 356 401- 41, 356 501- 515, 356 6- 22, 356/28, 356/28.5
• US Class Current: 356/4.01
• CPC Class Codes: G01C 3/08 Use of electric radiation detectors
• CPC Class Codes: G01S 17/04 Systems determining the presence of a target
• CPC Class Codes: G01S 7/4815 using multiple transmitters
• CPC Class Codes: H03K 17/943 using a plurality of optical emitters or detectors, e.g. keyboard
• CPC Class Codes: H03K 2217/94108 making use of reflection

Abstract

An integrated proximity and light sensor includes a first light-emitting device, a second light-emitting device, and a light sensing circuit configured as a single package. The light sensing circuit is configured to control the first light-emitting device and the second light-emitting device to emit light therefrom. Further, the light sensing circuit is configured to detect an ambient light level and to detect a reflection of the light emitted by the first light-emitting device from a surface for proximity detection. The light sensing circuit is also configured to control the second light-emitting device to stop emitting light therefrom for one or more of the ambient light level detection and the proximity detection.

Claims

1. An integrated proximity and light sensor, comprising:

a first light-emitting device, a second light-emitting device, and a light sensing circuit,

wherein the light sensing circuit is configured to control the first light-emitting device to emit infrared light and the second light-emitting device to emit visible light,

and wherein the light sensing circuit is configured to detect an ambient light level and to detect a reflection of the light emitted by the first light-emitting device from a surface for proximity detection,

further wherein the light sensing circuit is configured to control the second light-emitting device to stop emitting light therefrom for one or more of the ambient light level detection or the proximity detection.

2. The integrated proximity and light sensor of claim 1, further comprising a light isolation housing enclosing the first light-emitting device, the second light-emitting device, and the light sensing circuit.

3. The integrated proximity and light sensor of claim 2, wherein the light isolation housing further includes a light isolation partition that optically isolates the first light-emitting device from the light sensing circuit.

4. The integrated proximity and light sensor of claim 2, wherein the light isolation housing further includes one or more optical ports disposed over the first light-emitting device and the second light-emitting device, wherein light emitted from the first light-emitting device and the second light-emitting device transmits through the one or more optical ports.

5. The integrated proximity and light sensor of claim 1, wherein the light sensing circuit includes one or more sensors that sense visible light for the ambient light level detection and that sense infrared light for the proximity detection.

6. The integrated proximity and light sensor of claim 1, wherein the light sensing circuit is coupled to first and second switches, and wherein the first switch controls a first current passing through the first light-emitting device and the second switch controls a second current passing through the second light-emitting device.

7. The integrated proximity and light sensor of claim 6, wherein the first switch includes a first transistor with a first gate connected to and controlled by the light sensing circuit and the second switch includes a second transistor with a second gate connected to and controlled by the light sensing circuit.

8. The integrated proximity and light sensor of claim 1, wherein the light sensing circuit is configured to control the second light-emitting device to stop emitting light therefrom for a time period shorter than about 30 milliseconds for the ambient light level detection.

9. The integrated proximity and light sensor of claim 1, wherein the light sensing circuit is configured to control the second light-emitting device to stop emitting light therefrom for a time period shorter than 30 milliseconds and to control the first light-emitting device to emit light therefrom for a time period shorter than 30 milliseconds for the proximity detection.

19. The integrated proximity and light sensor of claim 1, wherein the first light-emitting device, the second light-emitting device, and the light sensing circuit are configured as a single package.

10. A sensor, comprising:

a light-emitting device; and

a light sensing circuit coupled to the light-emitting device,

wherein the light sensing circuit is configured to control the light-emitting device to emit visible light therefrom,

and wherein the light sensing circuit is configured to detect an ambient light level,

further wherein the light sensing circuit is configured to control the light-emitting device to stop emitting visible light therefrom for the ambient light level detection.

11. The sensor of claim 10, further comprising a light isolation housing enclosing the light-emitting device and the light sensing circuit.

12. The sensor of claim 11, wherein the light isolation housing further includes a light isolation partition that optically isolates the light-emitting device from the light sensing circuit.

13. The sensor of claim 11, wherein the light isolation housing further includes an optical port disposed over the light-emitting device, wherein visible light emitted from the light-emitting device transmits through the optical port.

14. The sensor of claim 10, wherein the light sensing circuit is configured to control the light-emitting device to stop emitting visible light therefrom for a time period shorter than about 30 milliseconds for the ambient light level detection.

20. The sensor of claim 10, wherein the light sensing circuit is configured as a single package with the light-emitting device.

15. A sensor, comprising:

a first light-emitting device, a second light-emitting device, and a light sensing circuit,

wherein the light sensing circuit is configured to control the first light-emitting device to emit infrared light and the second light-emitting device to emit visible light,

and wherein the light sensing circuit is configured to detect a reflection of the light emitted by the first light-emitting device from a surface for proximity detection,

further wherein the light sensing circuit is configured to control the second light-emitting device to stop emitting light therefrom for the proximity detection.

16. The sensor of claim 15, further comprising a light isolation housing enclosing the first light-emitting device, the second light-emitting device, and the light sensing circuit.

17. The sensor of claim 16, wherein the light isolation housing further includes a light isolation partition that optically isolates the first light-emitting device from the light sensing circuit.

18. The sensor of claim 16, wherein the light isolation housing further includes one or more optical ports disposed over the first light-emitting device and the second light-emitting device, wherein light emitted from the first light-emitting device and the second light-emitting device transmits through the one or more optical ports.

21. The sensor of claim 15, wherein the first light-emitting device, the second light-emitting device, and the light sensing circuit are configured as a single package.