Path light feedback compensation

• US 9,332,616 B1
• Filed: 12/30/2014
• Issued: 05/03/2016
• Est. Priority Date: 12/30/2014
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Fadell, Anthony Michael, Malhotra, Mark Rajan, Modi, Yash, Ma, Shao-Po
• Primary Examiner(s): Le, Don
• Application Number:
  US14/585,225
• Time in Patent Office: 490 Days
• Field of Search: 315/151, 315/152, 315/291
• US Class Current: 1/1
• CPC Class Codes: G01J 1/4204 with determination of ambient light solar light G01J2001/4266
• CPC Class Codes: G01J 1/44 Electric circuits for command of an exposure part G03B7/02
• CPC Class Codes: G01J 2001/444 Compensating; Calibrating, e.g. dark current, temperature drift, noise reduction or baseline correction; Adjusting
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 47/11 by determining the brightness or colour temperature of ambient light
• CPC Class Codes: H05B 47/115 by determining the presence or movement of objects or living beings
• CPC Class Codes: H05B 47/13 by using passive infrared detectors
• CPC Class Codes: H05B 47/16 by timing means
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

A path light that utilizes an ambient light sensor to determine the lighting conditions may experience feedback from its light source if it determines that the lighting conditions are appropriate to illuminate the path light'"'"'s light source. The path light, as disclosed herein, may compute an offset value to ascertain the amount of feedback from the light source. Upon learning the offset value, the path light may subtract the offset value from a detected amount of light to determine whether the lighting conditions of its surroundings still meet a threshold level of darkness for the path light to illuminate.

Claims

1. A computer-implemented method, comprising:

determining a first ambient light value based on a first amount of light detected by an ambient light sensor;

illuminating a light source integrated into a device with the ambient light sensor;

determining a second ambient light value based on a second amount of light detected by the ambient light sensor when the light source is illuminated at an intensity;

computing an offset value representing a difference between the first ambient light value and the second ambient light value;

detecting a motion;

computing a third ambient light value based on a third amount of light detected by the ambient light sensor and the offset value; and

determining an illumination level of the light source based on the third ambient light value and the motion.

2. The method of claim 1, wherein the offset value is dynamically adjusted based on data generated by the ambient light sensor over a period of time.

3. The method of claim 1, wherein the first ambient light value and the second ambient light value are determined in a dark environment.

4. The method of claim 3, wherein the dark environment comprises an ambient light intensity of not more than 60 lux.

5. The method of claim 1, wherein the intensity of the light source is not more than 150 lux.

6. The method of claim 1, wherein the intensity of the light source is not more than 500 lux.

7. The method of claim 1, wherein the intensity of the light source is in a range from 125 lux to 550 lux inclusive.

8. The method of claim 1, wherein the device comprises a single device.

9. The method of claim 1, further comprising determining the illumination level of the light source based on a time of day.

10. The method of claim 1, wherein the motion is detected within a field of view of a different device and not within the field of view of the device that contains the light source and the ambient light sensor.

11. The method of claim 1, further comprising transmitting, from the device, a signal indicating the motion.

12. A path light device, comprising:

an ambient light sensor;

a light source;

a processor communicatively coupled to the light source and the ambient light sensor, the processor configured to;

determine a first ambient light value based on a first amount of light detected by the ambient light sensor;

illuminating the light source;

determine a second ambient light value based on a second amount of light detected by the ambient light sensor when the light source is illuminated at an intensity;

compute an offset value representing a difference between the first ambient light value and the second ambient light value;

detect a motion;

compute a third ambient light value based on a third amount of light detected by the ambient light sensor and the offset value; and

determine an illumination level of the light source based on the third ambient light value and the motion.

13. The path light device of claim 12, wherein the offset value is dynamically adjusted based on data generated by the ambient light sensor over a period of time.

14. The path light device of claim 12, wherein the first ambient light value and the second ambient light value are determined in a dark environment.

15. The path light device of claim 14, wherein the dark environment comprises an ambient light intensity of not more than 60 lux.

16. The path light device of claim 12, wherein the intensity of the light source is not more than 150 lux.

17. The path light device of claim 12, wherein the intensity of the light source is not more than 500 lux.

18. The path light device of claim 12, wherein the intensity of the light source is in a range from 125 lux to 550 lux inclusive.

19. The path light device of claim 12, the processor further configured to determine the illumination level of the light source based on a time of day.

20. The path light device of claim 12, wherein the processor is configured to detect the motion within a field of view of a different device and not within the field of view of the path light device.

21. The system of claim 12, the processor further configured to transmit, from the path light device, a signal indicating the motion.

22. A computer-implemented method, comprising:

obtaining an offset value for a path light corresponding to a difference between a first amount of light detected by an ambient light sensor of the path light when a light source of the path light is illuminated at an intensity and a second amount of light detected by the ambient light sensor when the light source is inactive;

receiving, by the path light, an activation signal;

activating the light source at the intensity;

detecting a third amount of light by the ambient light sensor;

subtracting the offset value from the third amount of light to produce an adjusted light level; and

determining if the adjusted light level is below a threshold.

23. The method of claim 22, further comprising illuminating the light source of the path light in response to a determination that the adjusted light level is below the threshold.

24. A computer-implemented method, comprising:

determining a first offset value for a path light corresponding to a difference between a first amount of light detected by an ambient light sensor of the path light when a light source of the path light is illuminated at an intensity and a second amount of light detected by the ambient light sensor when the light source is inactive;

determining a first environmental light amount by the ambient light sensor;

applying the first offset value to the environmental light amount;

receiving a re-test signal;

responsive to the re-test signal, determining a second offset value for the path light corresponding to a difference between a third amount of light detected by the ambient light sensor of the path light when the light source of the path light is illuminated at the intensity and a fourth amount of light detected by the ambient light sensor when the light source is inactive;

determining a second environmental light amount by the ambient light sensor; and

applying the second offset value to the second environmental light amount.

25. The method of claim 24, further comprising:

determining that the second environmental light amount is below a threshold; and

illuminating the light source of the path light in response to a determination that the second environmental light amount is below the threshold.