Photosensor with customizable angular-response characteristics

• US 7,592,583 B2
• Filed: 02/07/2008
• Issued: 09/22/2009
• Est. Priority Date: 02/07/2007
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Papamichael, Konstantinos, Siminovitch, Michael, Page, Erik, Graeber, Keith
• Primary Examiner(s): Epps; Georgia Y
• Assistant Examiner(s): BENNETT, JENNIFER D
• Application Number:
  US12/027,866
• Publication Number:
  US 20080185507A1
• Time in Patent Office: 593 Days
• Field of Search: 250/216, 250/237.R, 250/227.29, 250/227.3, 250/215, 250/226, 250/239, 250/203.2, 250/221, 356/416, 362611-622
• US Class Current: 250/216
• CPC Class Codes: G01J 1/02 Details
• CPC Class Codes: G01J 1/0242 Control or determination of height or angle information of sensors or receivers; Goniophotometry
• CPC Class Codes: G01J 1/04 Optical or mechanical part supplementary adjustable parts
• CPC Class Codes: G01J 1/0474 Diffusers cavities G01J2001/0481
• CPC Class Codes: G01J 1/06 Restricting the angle of incident light
• CPC Class Codes: G01J 2001/061 Baffles

Abstract

A photosensor with customizable angular-response characteristics is presented. This photosensor includes a light-modifier located between the photosensor and a target area to be monitored by the photosensor, wherein the light-modifier provides a customizable angular response for light received at the photosensor from the target area.

Claims

1. A photosensor with customizable angular-response characteristics, comprising:

the photosensor; and

a light-modifier located between the photosensor and a target area to be monitored by the photosensor;

wherein the light-modifier provides a customizable angular response for light received at the photosensor from the target area, which involves providing an angular response for light received at the photosensor from the target area which substantially matches a specified angular-light-distribution characteristic on the target area illuminated by a light source.

2. The photosensor of claim 1, wherein the light-modifier includes one or more of:

a baffle that defines a field-of-view for the photosensor;

a light filter that filters light received by the photosensor;

a light-diffuser which diffuses light received by the photosensor;

a refractive layer which refracts light received by the photosensor; and

a transmissive lens that operates on light received by the photosensor.

3. The photosensor of claim 1, wherein the light-modifier facilitates measuring customized weights for light levels received from the target area, which involves one or more of the following:

measuring a weighted average of light levels in the target area in a manner that that accounts for distance from the photosensor;

measuring a weighted average of light levels in the target area in a manner that that accounts for angular sensitivity;

measuring a weighted response for light levels in the target area in a manner that accounts for regions with high desired light-sensitivity, regions with low desired light-sensitivity, and/or regions with no desired light-sensitivity;

adjusting angular sensitivity and field-of-view to asymmetrically measure light levels for the target area; and

creating a uniform weighing technique that treats all areas with the target area evenly.

4. The photosensor of claim 1, wherein the light-modifier is configured to be customized and/or changed.

5. The photosensor of claim 4, wherein the light-modifier is configured to be customized to provide application-specific angular sensitivities.

6. The photosensor of claim 1, wherein the light modifier includes a light filter which is manufactured and/or printed on a film as a pattern that selectively filters light to achieve a desired angular distribution of light-sensitivity for the target area.

7. The photosensor of claim 1,

wherein the light modifier includes a baffle which is shaped as a tube;

and

wherein the shape, length, and/or opening of the tube are adjusted to facilitate a specified angular acceptance of light from the target area.

8. The photosensor of claim 7, wherein the interior of the baffle includes of one or more of:

a light-absorbing material; and

a light-reflecting material.

9. The photosensor of claim 8, wherein the light-reflecting material includes one or more of:

a light-diffusing material; and

a specular material.

10. The photosensor of claim 7, wherein one or more surfaces of the baffle are colored and/or coated to prevent light reflection.

11. The photosensor of claim 1, wherein the light modifier includes a lens or a diffuser with a configurable shape, wherein the configurable shape can be configured to achieve a specific customized angular sensitivity.

12. The photosensor of claim 1, wherein the photosensor is:

integrated into a light fixture;

mounted on a ceiling; and

/or

mounted on a wall.

13. The photosensor of claim 1, wherein the light-modifier provides a sharp cut-off angle for light received by the photosensor to eliminate measurement errors associated with bright objects located outside of a field of interest for the photosensor.

14. The photosensor of claim 1, wherein the light-modifier provides a weighted average response which factors a surface brightness directly below the photosensor less strongly than a surface brightness further away from the photosensor.

15. The photosensor of claim 1, wherein the customizable angular response of light-modifier can be preset at a factory and/or adjusted by a user.

16. A lighting fixture, comprising:

a light source which produces a specified angular-light-distribution on a target area to be illuminated by the light source; and

a photosensor with customizable angular-response characteristics, wherein the photosensor includes a light-modifier located between the photosensor and the target area to be illuminated; and

wherein the light-modifier is configured to provide a customizable angular response for light received at the photosensor from the target area, which involves providing an angular response for light received at the photosensor from the target area which substantially matches the specified angular-light-distribution characteristic on the target area illuminated by the light source.

17. The lighting fixture of claim 16, wherein the light-modifier includes one or more of:

a baffle that defines a field-of view for the photosensor;

a light filter that filters light received by the photosensor;

a light-diffuser which diffuses light received by the photosensor;

a refractive layer which refracts light received by the photosensor; and

a transmissive lens that operates on light received by the photosensor.

18. The lighting fixture of claim 16, wherein the light-modifier facilitates measuring customized weights for light levels received from the target area, which involves one or more of the following:

measuring a weighted average of light levels in the target area in a manner that that accounts for distance from the photosensor;

measuring a weighted average of light levels in the target area in a manner that that accounts for angular sensitivity;

measuring a weighted response for light levels in the target area in a manner that accounts for regions with high desired light-sensitivity, regions with low desired light-sensitivity, and/or regions with no desired light-sensitivity;

adjusting angular sensitivity and field-of-view to asymmetrically measure light levels for the target area; and

creating a uniform weighing technique that treats all areas with the target area evenly.

19. The lighting fixture of claim 16, wherein the light-modifier is configured to be customized and/or changed.