Particle detector for particulate matter accumulated on a surface

Patent metadata

Field	Value
Publication number	US-9851290-B2
Application number	US-201514746739-A
Country	US
Kind code	B2
Filing date	Jun 22, 2015
Priority date	Jun 22, 2015
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

Particle detectors and methods for detecting particulate matter accumulated on a surface are provided. According to one aspect, the particle detector may comprise a substrate, an optical light source configured to emit light along a light path, a waveguide associated with the substrate, having a surface exposed to a gaseous environment and configured to accumulate on the surface particulate matter from the gaseous environment, a detector configured to receive the emitted light from the waveguide, and a controller configured to determine the intensity of the detected light and output an indication of an opacity of the surface of the waveguide with the accumulated particulate matter.

First claim

The invention claimed is:

1. A particulate matter detector comprising:
a substrate;
an optical light source configured to emit light having an intensity along a light path;
a waveguide associated with the substrate, having a surface exposed to a gaseous environment and the waveguide surface configured to accumulate directly thereon particulate matter from the gaseous environment;
a detector configured to receive the emitted light from the waveguide; and
a controller configured to determine a change in the intensity of the light emitted from the waveguide, and output an indication of an opacity of the surface of the waveguide with the accumulated particulate matter thereon based on a change in intensity of the emitted light; wherein the controller determines an indication of an opacity of the surface of the waveguide with the accumulated particulate matter by comparing the detected intensity with a known intensity at the optical light source.

2. The particulate matter detector of claim 1 , wherein
the light source includes an optical emitter; and
the particulate matter detector includes a first optical grating disposed along the light path and configured to structure the light received from the optical emitter into structured light and pass the structured light into the waveguide.

3. The particulate matter detector of claim 2 , further comprising:
a second optical grating disposed along the light path and configured to receive the structured light and pass the structured light to the detector.

4. The particulate matter detector of claim 1 , wherein the controller is further configured to output an indication of a density of the accumulated particulate matter based on the opacity.

5. The particulate matter detector of claim 4 , wherein the controller outputs the density expressed in terms of average particle size based on the opacity.

6. The particulate matter detector of claim 1 , wherein the substrate, the first optical grating, and the second optical grating consist of a same material.

7. The particulate matter detector of claim 1 , wherein the substrate is a glass panel.

8. The particulate matter detector of claim 7 , wherein the glass panel is incorporated into a window, solar panel, display, or vehicle windshield.

9. The particulate matter detector of claim 1 , wherein the controller is configured to output an alert message based on the opacity, the alert message being a service alert message or pollution alert message.

10. The particulate matter detector of claim 1 , wherein at least the waveguide is formed in a film adhered to the substrate.

11. The particulate matter detector of claim 1 , wherein:
the waveguide is formed in a serpentine pattern; or
the waveguide is one of a plurality of waveguides, the plurality of waveguides formed in a matrix pattern.

12. The particulate matter detector of claim 1 , wherein the waveguide is one of a plurality of waveguides, the plurality of waveguides formed in separate rows.

13. A method for detecting particulate matter accumulated on a surface of a waveguide, the method comprising:
accumulating the particulate matter from a gaseous environment directly on the surface of a waveguide;
emitting light having an intensity along a light path within the waveguide associated with a substrate;
receiving the emitted light from emitted from the waveguide;
determining the intensity of the received light;
outputting an indication of an opacity of the waveguide surface based on a change in the intensity of the emitted light resulting from the particulate matter; wherein the indication of an opacity of the surface of the waveguide with the accumulated particulate matter is calculated by comparing the intensity of the received light with the intensity of the emitted light.

14. The method of claim 13 , further comprising:
receiving the light emitted by a light source;
structuring the light into structured light with a first optical grating; and
passing the structured light into the waveguide.

15. The method of claim 14 , further comprising:
receiving the structured light from the waveguide at a second optical grating; and
passing the structured light to the detector.

16. The method of claim 14 , further comprising outputting an indication of a density of the accumulated particulate matter based on the opacity, wherein the density is expressed in terms of average particle size based on the opacity.

17. The method of claim 13 , wherein the substrate, the first optical grating, and the second optical grating consist of glass, and the substrate is a glass panel.

18. The method of claim 17 , wherein the glass panel is incorporated into a window, solar panel, display, or vehicle windshield.

19. The method of claim 13 , further comprising outputting an alert message based on the opacity, the alert message being a service alert message or pollution alert message.

20. A particle detector incorporated into a solar panel, the particle detector comprising:
a substrate;
an optical light source including at least one optical emitter configured to emit light along a respective light path;
a plurality of waveguides formed in separate rows, each waveguide having a surface exposed to a gaseous environment and configured to accumulate on the surface particulate matter from the gaseous environment, an associated first optical grating disposed along the respective light path configured to structure the light received from the optical emitter into structured light and pass the structured light into the waveguide, and an associated second optical grating disposed along the light path and configured to receive the structured light from the waveguide;
at least one detector configured to receive the emitted light from each waveguide via the respective second optical grating; and
a controller configured to determine an intensity of the detected light for each waveguide, and output an indication of an opacity of the surface of at least one of the plurality of waveguides with the accumulated particulate matter; wherein
the controller is configured to compare the intensity of the detected light for at least two waveguides, and if a difference between the at least two intensities exceeds a predetermined threshold, the controller is configured to output an error message.

Assignees

• Sharp Laboratories America Inc

Inventors

• Zhan Changqing
• Schuele Paul John

Classifications

• G01N2015/1486

  Counting the particles · CPC title

• G01N15/0606 Primary

  by collecting particles on a support · CPC title

• G01N15/1434 Primary

  Optical arrangements · CPC title

• G01N21/59

  Transmissivity (G01N21/25 takes precedence) · CPC title

• G01N2015/0046

  in gas, e.g. smoke · CPC title