Near-infrared sensor cover

Patent metadata

Field	Value
Publication number	US-11624658-B2
Application number	US-202017096204-A
Country	US
Kind code	B2
Filing date	Nov 12, 2020
Priority date	Nov 18, 2019
Publication date	Apr 11, 2023
Grant date	Apr 11, 2023

Abstract

A near-infrared sensor cover includes a cover body having transmissiveness to near-infrared rays. The cover body includes a base and a heater unit. The heater unit is arranged rearward of the base in a transmission direction of the near-infrared rays and includes a wire-like heating element. The heating element is configured to generate heat when energized. The base includes a rear portion that includes a rear surface of the base in the transmission direction. In the rear portion of the base, at least part of a section that is different from a section in which the heater unit is provided is formed by a reflection suppression structure including asperities. The asperities include a reflection suppression surface that is inclined relative to the transmission direction and reduces reflection of the near-infrared rays.

First claim

What is claimed is:

1. A near-infrared sensor cover configured to cover a transmitting unit and a receiving unit for near-infrared rays in a near-infrared sensor, the near-infrared sensor cover comprising:
a cover body having transmissiveness to near-infrared rays, wherein
the cover body includes:
a base made of a plastic, and
a heater unit that is arranged rearward of the base in a transmission direction of the near-infrared rays and includes a wire-like heating element, the heating element configured to generate heat when energized,

the base includes a rear portion that includes a rear surface of the base in the transmission direction,
in the rear portion of the base, at least part of a section that is different from a section in which the heater unit is provided is formed by a reflection suppression structure including asperities, and
the asperities include a reflection suppression surface that is inclined relative to the transmission direction and reduces reflection of the near-infrared rays.

2. The near-infrared sensor cover according to claim 1 , wherein
the reflection suppression structure includes protrusions,
the protrusions each include the reflection suppression surface and are adjacent to and parallel with each other, and
each protrusion has a triangular cross section.

3. The near-infrared sensor cover according to claim 2 , wherein
a height of each protrusion from a base to a vertex is constant in a direction in which the protrusion extends,
the height of each protrusion is set to be in a range from 150 nm to 400 nm, and
a measurement of the base of each protrusion in an arrangement direction of the protrusions is set to be in a range from 170 nm to 200 nm.

4. The near-infrared sensor cover according to claim 2 , wherein
each protrusion includes concavities that are connected together in a direction in which the protrusion extends,
each concavity is arcuately recessed from a vertex toward a base of the protrusion, and a depth of the concavity varies in the direction in which the protrusion extends,
a height of each protrusion from the base to a highest position in the vertex is set to be in a range from 150 nm to 400 nm,
a measurement of the base of each protrusion in an arrangement direction of the protrusions is set to be in a range from 150 nm to 400 nm,
a radius of each concavity is set to be in a range from 1 mm to 10 mm,
a pick feed, which is a measurement of each concavity in a direction in which the protrusions extend, is set to be in a range from 30 μm to 90 μm, and
a scallop, which is a depth of each concavity, is set to be in a range from 0.01 μm to 0.1 μm.

5. The near-infrared sensor cover according to claim 1 , wherein
the reflection suppression structure includes projections each having a shape of a polygonal pyramid and the reflection suppression surface, and
the projections are arranged in two intersecting directions, while being adjacent to each other.

6. The near-infrared sensor cover according to claim 5 , wherein
each projection has a shape of a quadrangular pyramid and includes first and second base edges that are adjacent to each other,
a length of the first base edge is set to be in a range from 170 nm to 200 nm,
a length of the second base edge is set to be in a range from 170 nm to 200 nm,
the projections are arranged such that the first base edges are arranged linearly and the second base edges are arranged linearly, and
a height of each projection is set to be in a range from 150 nm to 400 nm.

7. The near-infrared sensor cover according to claim 1 , comprising:
a hydrophilization film that is provided rearward in the transmission direction of the reflection suppression structure,
wherein the reflection suppression structure is covered with the hydrophilization film.

Assignees

• Toyoda Gosei Kk
• Imuzak Corp

Inventors

• Okumura Koji
• Fukagawa Koji
• Sawamura Kazumi

Classifications

• G01J1/0271

  Housings; Attachments or accessories for photometers · CPC title

• H05B3/845

  specially adapted for reflecting surfaces, e.g. bathroom - or rearview mirrors · CPC title

• G01J5/04 Primary

  Casings · CPC title

• G01S17/931

  of land vehicles · CPC title

• G01J2005/063

  Heating; Thermostating · CPC title