Optical sensor systems

Patent metadata

Field	Value
Publication number	US-11354880-B2
Application number	US-201816758769-A
Country	US
Kind code	B2
Filing date	Oct 25, 2018
Priority date	Oct 27, 2017
Publication date	Jun 7, 2022
Grant date	Jun 7, 2022

Abstract

Systems, assemblies, and methods for detecting changes in polarization states are described. Example systems may include a light receiving unit including a sensor and a receiving polarizer. The sensor is configured to sense light from a polarized light source deflected through the receiving polarizer by a light directing article. The sensor is configured to generate a signal indicative a received polarization state of light deflected by the light directing articles. Such systems may be coupled to vehicles and may be useful for sensor-detectable signs, indicia, and markings to facilitate automated or assisted vehicular transport.

First claim

The invention claimed is:

1. A system comprising:
a light directing article comprising a plurality of polarization change features arranged in a predetermined spatial pattern on the light directing article and configured to change polarization of incident light into a plurality of predetermined different polarization states of reflected light, each polarization state of the predetermined different polarization states being associated with a relative location of a polarization change feature of the plurality of polarization change features along the light directing article; and
a light receiving unit comprising a sensor and a receiving polarizer, wherein the sensor is configured to sense light from a polarized light source deflected through the receiving polarizer by the light directing article, and wherein the sensor is configured to generate a signal indicative of a received polarization state of the light deflected by the light directing article.

2. The system of claim 1 , wherein the light directing article is configured to change polarization of light emitted by the polarized light source.

3. The system of claim 1 , further comprising the polarized light source.

4. The system of claim 1 , wherein the polarized light source comprises a diffuse light source and a source polarizer.

5. The system of claim 1 , wherein the light directing article comprises a retroreflective article.

6. A method comprising:
receiving, by a light receiving unit, light from a polarized light source deflected by a light directing article, the light receiving unit comprising a plurality of sensor elements and a plurality of receiving polarizers, each receiving polarizer configured to transmit a predetermined polarization state to a sensor element corresponding to the receiving polarizer, at least two different receiving polarizers transmitting at least two different predetermined polarization states to at least two different corresponding sensor elements; and
generating, by the light receiving unit, a signal indicative of a received polarization state of the light deflected by the light directing article.

7. The method of claim 6 , further comprising:
transmitting, by the polarized light source, light having a predetermined source polarization state towards the light directing article.

8. An assembly comprising:
a polarized light source; and
a light receiving unit comprising a plurality of sensor elements and a plurality of receiving polarizers, each receiving polarizer configured to transmit a predetermined polarization state to a sensor element corresponding to the receiving polarizer, at least two different receiving polarizers transmitting at least two different predetermined polarization states to at least two different corresponding sensor elements, the light receiving unit configured to generate a signal indicative of a received polarization state of light received by the light receiving unit.

9. The assembly of claim 8 , wherein the polarized light source is oriented to emit polarized light along a predetermined path, and wherein the light receiving unit is oriented to receive light substantially within a predetermined light cone about the predetermined path or along a direction substantially parallel to the predetermined path.

10. The assembly of claim 8 , further comprising a housing, wherein the polarized light source and the light receiving unit secured adjacent to each other in the housing.

11. The assembly of claim 8 , wherein the at least two different predetermined polarization states comprise a linear polarization state and a circular polarization state.

12. The method of claim 6 , wherein the at least two different predetermined polarization states comprise a linear polarization state and a circular polarization state.

Assignees

• 3M Innovative Properties Co

Inventors

• Shaver Jonah
• Clear Susannah C
• Wheatley John A
• Chen-Ho Kui

Classifications

• H04B10/1125 Primary

  using a single common optical path · CPC title

• G06V10/147 Primary

  Details of sensors, e.g. sensor lenses (fingerprint or palmprint sensors G06V40/13; vascular sensors G06V40/145; eye sensors G06V40/19) · CPC title

• H04B10/116

  Visible light communication · CPC title

• H04B10/614

  comprising one or more polarization beam splitters, e.g. polarization multiplexed [PolMux] X-PSK coherent receivers, polarization diversity heterodyne coherent receivers (H04J14/06 takes precedence) · CPC title