PHOTOSENSOR WITH CUSTOMIZABLE ANGULAR-RESPONSE CHARACTERISTICS

• US 20080185507A1
• Filed: 02/07/2008
• Published: 08/07/2008
• 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: Siminovitch, Michael, Page, Erik, Graeber, Keith, Papamichael, Konstantinos
• Granted Patent: US 7,592,583 B2
• Time in Patent Office: Days
• US Class Current: 250/237R
• 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.

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 variable shape, wherein the variable shape can be varied 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.

17. The lighting fixture of claim 16, wherein the light-modifier is configured to provide 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.

18. 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.

19. 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.

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