Fluorescent fiber light sensor

Patent metadata

Field	Value
Publication number	US-9765950-B2
Application number	US-201314391115-A
Country	US
Kind code	B2
Filing date	Apr 5, 2013
Priority date	Apr 12, 2012
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

Generally, the present disclosure provides for a light duct sensor that can monitor an average light flux through light duct useful for architectural lighting. The present disclosure provides for a system that allows a minimally obtrusive sampling of the light in a duct. It samples a small fraction of a cross sectional area of a light duct that is distributed across potentially the entire cross sectional area, without creating a significant disturbance to the light.

First claim

What is claimed is:

1. A light duct sensor, comprising:
a light detecting region comprising a cross-sectional area of a hollow light duct;
an optical fiber disposed within the detecting region capable of intercepting light incident on a longitudinal surface of the optical fiber and guiding the intercepted light within the optical fiber; and
a sensor disposed to accept an emitted light from at least one of a first end and a second end of the optical fiber, the sensor capable of detecting the emitted light intensity.

2. The light duct sensor of claim 1 , wherein the optical fiber is disposed to traverse at least one of a width and a height of the hollow light duct.

3. The light duct sensor of claim 1 , wherein the optical fiber is disposed to traverse a width and a height of the hollow light duct.

4. The light duct sensor of claim 1 , wherein the optical fiber is disposed to traverse the cross-sectional area in a mesh pattern.

5. The light duct sensor of claim 4 , wherein the mesh pattern comprises a triangular mesh, a rectangular mesh, a pentagonal mesh, a hexagonal mesh, or a random mesh.

6. The light duct sensor of claim 1 , wherein the optical fiber comprises an inner core and an outer cladding, the inner core having a higher refractive index than the outer cladding.

7. The light duct sensor of claim 1 , further comprising a fluorescent material dispersed in the optical fiber.

8. The light duct sensor of claim 7 , wherein the fluorescent material is capable of converting a first wavelength of light to a second wavelength of light.

9. The light duct sensor of claim 1 , further comprising a scattering material dispersed in the optical fiber.

10. The light duct sensor of claim 1 , further comprising surface re-directing features on the optical fiber.

11. The light duct sensor of claim 1 , wherein the emitted light intensity can be correlated to an average light flux within a hollow light duct.

12. A light duct sensor, comprising:
a hollow light duct section having a cross-sectional area;
an optical fiber traversing the cross-sectional area to intercept light incident on a longitudinal surface of the optical fiber;
a fluorescent material disposed in the optical fiber to convert a portion of the incident light; and
a sensor disposed to accept an emitted light from at least one of a first end or a second end of the optical fiber, the sensor capable of detecting an intensity of the emitted light.

13. The light duct sensor of claim 12 , wherein the optical fiber comprises an inner core and an outer cladding, the inner core having a higher refractive index than the outer cladding.

14. The light duct sensor of claim 12 , wherein the fluorescent material is capable of converting a first wavelength of light to a second wavelength of light, and the sensor is capable of detecting the second wavelength of light.

15. The light duct sensor of claim 12 , wherein the optical fiber is disposed to traverse the cross-sectional area in a mesh pattern.

16. The light duct sensor of claim 15 , wherein the mesh pattern comprises a triangular mesh, a rectangular mesh, a pentagonal mesh, a hexagonal mesh or a random mesh.

17. The light duct sensor of claim 12 , wherein a portion of the optical fiber is outside of the cross-sectional area.

18. The light duct sensor of claim 12 , wherein the optical fiber is woven through the hollow light duct section.

19. A method for controlling a light distribution system, comprising:
disposing a light duct sensor within a hollow light duct;
monitoring an average light flux within the hollow light duct using the light duct sensor;
detecting a change in the average light flux; and
controlling at least one of a solar collector positioning device, an auxiliary light injector, a diverter baffle, an extractor baffle, or a combination thereof, to control the average light flux.

20. The method of claim 19 , wherein the light duct sensor comprises:
a light detecting region comprising a cross-sectional area of the hollow light duct;
an optical fiber disposed within the detecting region capable of intercepting light incident on a longitudinal surface of the optical fiber and guiding the intercepted light within the optical fiber; and
a sensor disposed to accept an emitted light from at least one of a first end and a second end of the optical fiber, the sensor capable of detecting the emitted light intensity.

Assignees

• 3M Innovative Properties Co

Inventors

• Corrigan Thomas R
• Fleming Patrick R

Classifications

• F21V14/006 Primary

  by means of optical elements, e.g. films, filters or screens, being rolled up around a roller · CPC title

• G02B6/0008

  the light being emitted at the end of the fibre · CPC title

• G01J1/4204

  with determination of ambient light (solar light G01J2001/4266) · CPC title

• G02B6/0006

  Coupling light into the fibre (in general G02B6/4298) · CPC title

• G02B6/0003

  the light guides being doped with fluorescent agents · CPC title