Vehicle-mounted sensor, vehicle lamp, vehicle, and road surface state sensor

Patent metadata

Field	Value
Publication number	US-2017124402-A1
Application number	US-201615187796-A
Country	US
Kind code	A1
Filing date	Jun 21, 2016
Priority date	Oct 29, 2015
Publication date	May 4, 2017
Grant date	—

Abstract

A vehicle-mounted sensor to be mounted on a vehicle includes: a light emission unit that emits infrared light of a first wavelength range and infrared light of a second wavelength range into space outside the vehicle, a water molecule having respective different light absorption factors to the infrared light of the first wavelength range and the infrared light of the second wavelength range; a light detection unit that detects the infrared light of the first wavelength range and the infrared light of the second wavelength range separately; and a water detection unit that detects water in the space outside the vehicle on the basis of a difference between a light amount of the infrared light of the first wavelength range and that of the infrared light of the second wavelength range detected by the light detection unit.

First claim

1 . A vehicle-mounted sensor to be mounted on a vehicle, comprising:
a light emission unit for emitting infrared light of a first wavelength range and infrared light of a second wavelength range into space outside the vehicle, a water molecule having respective different light absorption factors to the infrared light of the first wavelength range and the infrared light of the second wavelength range; a light detection unit for separately detecting the infrared light of the first wavelength range and the infrared light of the second wavelength range; and a water detection unit for detecting water in the space outside the vehicle on a basis of a difference between a light amount of the infrared light of the first wavelength range and a light amount of the infrared light of the second wavelength range detected by the light detection unit.

2 . The vehicle-mounted sensor according to claim 1 , wherein
the light detection unit is an imaging apparatus for capturing an image of the infrared light of the first wavelength range and an image of the infrared light of the second wavelength range, and the water detection unit detects the water on a basis of a difference between the image of the infrared light of the first wavelength range and the image of the infrared light of the second wavelength range.

3 . The vehicle-mounted sensor according to claim 2 , wherein
the water detection unit detects an amount of water in each region in the space outside the vehicle to be imaged by the imaging apparatus, on a basis of a difference in a luminance value of each region between the image of the infrared light of the first wavelength range and the image of the infrared light of the second wavelength range.

4 . The vehicle-mounted sensor according to claim 2 , wherein
the water detection unit detects an amount of water droplets in each region in the space outside the vehicle to be imaged by the imaging apparatus, on a basis of a difference in the luminance value of each region between the image of the infrared light of the first wavelength range and the image of the infrared light of the second wavelength range, and the vehicle-mounted sensor further comprises an image processing unit for applying haze removal processing to each region of an image obtained by imaging the space outside the vehicle, on a basis of the amount of water droplets in each region detected by the water detection unit.

5 . The vehicle-mounted sensor according to claim 2 , wherein
the light emission unit emits the infrared light of the first wavelength range and the infrared light of the second wavelength range in a time division manner, and the imaging apparatus captures images in a time division manner in synchronization with the emission of the infrared light of the first wavelength range and the emission of the infrared light of the second wavelength range from the light emission unit, thereby capturing the image of the infrared light of the first wavelength range and the image of the infrared light of the second wavelength range in a time division manner.

6 . The vehicle-mounted sensor according to claim 2 , wherein
the imaging apparatus includes:
a light separation unit for separating light incident on the imaging apparatus into the infrared light of the first wavelength range and the infrared light of the second wavelength range;
a first imaging unit for capturing an image by using the infrared light of the first wavelength range separated by the light separation unit; and
a second imaging unit for capturing an image by using the infrared light of the second wavelength range separated by the light separation unit.

7 . The vehicle-mounted sensor according to claim 1 , wherein
the water detection unit detects whether a state of the water in the space outside the vehicle is a liquid phase or a solid phase on a basis of a difference between the light amounts, a difference between an absorption factor of water in the liquid phase to the infrared light of the first wavelength range and an absorption factor of the water to the infrared light of the second wavelength range, and a difference between an absorption factor of water in the solid phase to the infrared light of the first wavelength range and an absorption factor of the water to the infrared light of the second wavelength range.

8 . The vehicle-mounted sensor according to claim 1 , wherein
the light emission unit emits infrared light of the first wavelength range including a first circular polarization component and infrared light of the second wavelength range including the first circular polarization component to outside the vehicle, the vehicle-mounted sensor further comprises a circular polarization filter for transmitting a second circular polarization component of light from the space outside the vehicle, the second circular polarization component rotating in a direction opposite to a rotation direction of the first circular polarization component, and the light detection unit detects the infrared light of the first wavelength range and the infrared light of the second wavelength range transmitted through the circular polarization filter.

9 . A vehicle lamp comprising:
the vehicle-mounted sensor according to claim 1 ; and an illumination light source for emitting visible illumination light for illuminating outside the vehicle.

10 . A vehicle comprising the vehicle-mounted sensor according to claim 1 .

11 . A road surface state sensor for detecting a state of water on a road surface, comprising:
a light emission unit for emitting infrared light of a first wavelength range and infrared light of a second wavelength range into the road surface, a water molecule having respective different light absorption factors to the infrared light of the first wavelength range and the infrared light of the second wavelength range; a light detection unit for separately detecting the infrared light of the first wavelength range and the infrared light of the second wavelength range; and a water detection unit for detecting whether a state of water on the road surface is a liquid phase or a solid phase on a basis of a difference between a light amount of the infrared light of the first wavelength range and a light amount of the infrared light of the second wavelength detected by the light detection unit, a difference between an absorption factor of water in the liquid phase to the infrared light of the first wavelength range and an absorption factor of the water to the infrared light of the second wavelength range, and a difference between an absorption factor of water in the solid phase to the infrared light of the first wavelength range and an absorption factor of the water to the infrared light of the second wavelength range.

Assignees

• Smk Kk

Inventors

• Tanaka Tsubasa
• Kondo Haruhiko
• Ito Natsumi

Classifications

• G06V20/56

  exterior to a vehicle by using sensors mounted on the vehicle · CPC title

• B60Q1/0023 Primary

  the element being a sensor, e.g. distance sensor, camera · CPC title

• H04N23/56

  provided with illuminating means · CPC title

• G06F18/24

  Classification techniques · CPC title

• G06V10/143

  Sensing or illuminating at different wavelengths · CPC title