Optical sensor systems

{
  "publication_number": "US11354880B2",
  "country": "US",
  "kind": "B2",
  "title": "Optical sensor systems",
  "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.",
  "claims": [
    "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."
  ],
  "description_excerpt": "The disclosure describes optical sensor systems, in particular, optical sensor systems for vehicles.\n\nAutomated driving technology makes use of optical sensor systems to detect roadway objects which can include infrastructure, other vehicles, or pedestrians. Increasing the range of detectability, improving signal to noise, and improving the recognition of objects continue to be fields of development. Systems that can provide at a distance, conspicuity, identification, and data via optical sensor systems, while being substantially visually imperceptible, may be advantageous. For example, signs may serve a dual purpose, where the sign may be visually read in the traditional way, and simultaneously the optical system can sense an invisible code that assists an onboard driving system with automated driving.\n\nOther industry problems regarding optical sensors include the need to improve detection in adverse conditions that may affect light path and quality, which can cause signal to noise problems for the detection of infrastructure, vehicles, or pedestrians.\n\nThe disclosure describes example systems, methods, and computer program products that may be useful for sensor-detectable signs, indicia, and markings to facilitate automated or assisted automobile transport.\n\nThe disclosure describes an example system including a light receiving unit. The light receiving unit includes 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.",
  "cpc": [
    "H04B 10/1125",
    "G06V 10/147",
    "H04B 10/116",
    "H04B 10/614"
  ],
  "ipc": [
    "G06V 10/147",
    "H04B 10/116",
    "H04B 10/61"
  ],
  "assignees": [
    "3M Innovative Properties Co"
  ],
  "inventors": [
    "Jonah Shaver",
    "Susannah C. Clear",
    "John A. Wheatley",
    "Kui Chen-Ho"
  ],
  "filing_date": "2018-10-25",
  "publication_date": "2022-06-07",
  "grant_date": "2022-06-07",
  "priority_date": "2017-10-27",
  "application_number": "US-201816758769-A",
  "family_id": "64332140",
  "cited_by_count": 2,
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