Optical fault monitoring

• US 9,063,001 B2
• Filed: 11/02/2012
• Issued: 06/23/2015
• Est. Priority Date: 09/14/2009
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Yee, Dawson
• Primary Examiner(s): Epps, Georgia Y
• Assistant Examiner(s): Wyatt, Kevin
• Application Number:
  US13/667,915
• Publication Number:
  US 20130056615A1
• Time in Patent Office: 963 Days
• Field of Search: 250/201.1, 250/559.39, 250/559.4, 250/559.41, 250/559.42, 250/559.43, 250/559.45, 250/559.46, 356/243.8, 359/15
• US Class Current: 1/1
• CPC Class Codes: G01J 1/02 Details
• CPC Class Codes: G01J 1/0228 Control of working procedures; Failure detection; Spectral bandwidth calculation
• CPC Class Codes: G01J 1/32 adapted for automatic variation of the measured or reference value regulation of light intensity G05D25/00

Abstract

Various embodiments related to monitoring for optical faults in an optical system are disclosed. For example, one disclosed embodiment provides, in an optical system comprising a light source, a light outlet, and an optical element disposed between the light source and the light outlet, a method of monitoring for optical system faults. The method includes detecting, via a light sensor directed toward an interface surface of the optical element closest to the light source, an intensity of light traveling from the interface surface of the optical element to the light sensor, and comparing an intensity of light detected to one or more threshold intensity values. The method further includes identifying an optical system fault condition based on comparing the intensity of light detected to one or more threshold values, and modifying operation of the optical system.

Claims

1. In an optical system comprising a light source, a light outlet, and an optical element disposed between the light source and the light outlet, a method of monitoring for optical system faults, the method comprising:

detecting, via a light sensor configured to receive light from an interface surface of the optical element closest to the light source, an intensity of light traveling from the interface surface of the optical element to the light sensor;

if a first optical system fault condition, due to a change in location of the optical element, is identified based upon the intensity of light, then modifying operation of the optical system in a first manner; and

if a second optical system fault condition, due to a physical object blocking an optical path, is identified based upon the intensity of light, then modifying operation of the optical system in a second manner that is different than the first manner.

2. The method of claim 1, further comprising identifying the first optical system fault condition by determining that the intensity of light detected, due to the change in location of the optical element, is less than a threshold value.

3. The method of claim 2, wherein modifying operation of the optical system in the first manner includes performing a shutdown operation to the optical system.

4. The method of claim 1, wherein identifying the second optical system fault condition includes determining that the intensity of light detected, based upon the physical object blocking the optical path, is greater than a threshold value.

5. The method of claim 4, wherein modifying operation of the optical system in the second manner includes providing a warning message for display on a display device.

6. The method of claim 5, further comprising detecting no response to the warning message, and performing a shutdown operation to the optical system.

7. The method of claim 6, further comprising, after performing the shutdown operation, detecting a response to the warning message and in response, returning the optical system to a normal operating state.

8. An optical device, comprising:

a light source configured to output a beam of light;

a diffractive optical element configured to receive the beam of light on a light-source side of the diffractive optical element and to diffract the beam of light to form a structured pattern;

a photodetector directed toward the light-source side of the diffractive optical element, the photodetector configured to measure an intensity of light traveling from the light-source side of the diffractive optical element; and

a controller configured to distinguish one or more optical fault conditions from proper optical device operation by monitoring the intensity of light as measured by the photodetector, and to take action corresponding to the one or more optical fault conditions.

9. The optical device of claim 8, wherein the controller is further configured to change a power state of the optical device if a first optical fault condition is detected.

10. The optical device of claim 9, wherein the controller is configured to detect the first optical fault condition by comparing the intensity of light to a first threshold.

11. The optical device of claim 8, wherein the controller is further configured to provide a warning message for display if a second optical fault condition is detected.

12. The optical device of claim 11, wherein the controller is configured to detect the second optical fault condition by comparing the intensity of light to a second threshold that is different from a first threshold used to detect the first optical fault condition.

13. The optical device of claim 11, wherein the controller is further configured to perform a shutdown operation if no response to the warning message is detected.

14. The optical device of claim 13, wherein the controller is further configured to, after performing the shutdown operation, detect a response to the warning message and in response, return the optical system to a normal operating state.

15. The optical device of claim 8, wherein the optical device is a depth-sensing camera.

16. An optical system, comprising:

a light source;

a light outlet;

one or more optical elements;

a light sensor configured to receive light from an interface surface of an optical element closest to the light source; and

a controller configured to;

control the light source to project a beam of light through the one or more optical elements;

detect, via the light sensor, an intensity of light transmitted through the optical element to the light sensor;

compare the intensity of light detected to one or more threshold intensity values;

identify an optical system fault condition based on comparing the intensity of light detected to the one or more threshold intensity values; and

take one or more actions based upon the optical system fault condition.

17. The method of claim 16, wherein identifying the optical system fault condition includes determining that the intensity of light detected is less than a threshold value.

18. The method of claim 17, wherein modifying operation of the optical system includes performing a shutdown operation to the optical system.

19. The method of claim 16, wherein identifying the optical system fault condition includes determining that the intensity of light detected is greater than a threshold value.

20. The method of claim 19, wherein modifying operation of the optical system includes displaying a warning message.