Light guide member having a curvatured detection face, object detection apparatus, and vehicle

• US 9,470,791 B2
• Filed: 08/25/2014
• Issued: 10/18/2016
• Est. Priority Date: 09/06/2013
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Yoshimura, Kenichi
• Primary Examiner(s): LE, QUE TAN
• Application Number:
  US14/467,206
• Publication Number:
  US 20150069224A1
• Time in Patent Office: 785 Days
• Field of Search: 250/227.25, 250/227.14, 250/221, 250573-577, 250/208.1, 340601-604, 340555-557, 73/290.1
• US Class Current: 1/1
• CPC Class Codes: B60S 1/0833 Optical rain sensor
• CPC Class Codes: B60S 1/0837 with a particular arrangement of the optical elements
• CPC Class Codes: B60S 1/0844 including a camera
• CPC Class Codes: F21S 43/235 Light guides
• CPC Class Codes: G01N 2021/3155 Measuring in two spectral ranges, e.g. UV and visible
• CPC Class Codes: G01N 2021/9586 Windscreens
• CPC Class Codes: G01N 21/3554 for determining moisture content
• CPC Class Codes: G01N 21/43 by measuring critical angle
• CPC Class Codes: G01N 21/4738 Diffuse reflection precedence is given to G01N21/55 - G01N21/57 if specular component is taken into consideration, e.g. also for testing fluids, fibrous materials
• CPC Class Codes: G01N 21/552 Attenuated total reflection
• CPC Class Codes: G01N 2201/0626 Use of several LED's for spatial resolution
• CPC Class Codes: G01N 2201/0631 Homogeneising elements
• CPC Class Codes: G01N 2201/0636 Reflectors
• CPC Class Codes: G01N 2201/064 Stray light conditioning
• CPC Class Codes: G01S 17/04 Systems determining the presence of a target
• CPC Class Codes: G02B 5/04 Prisms
• CPC Class Codes: G06V 20/56 exterior to a vehicle by using sensors mounted on the vehicle

Abstract

A light guide member for an object detection apparatus is devised. The object detection apparatus includes a light source unit, and a detection unit for detecting an object adhered on a surface of a light translucent member based on change of light quantity of reflection light received from the light translucent member. The light guide member includes an incident face where the light exiting from the light source unit enters; a detection face where the exiting light exits to a rear face of the light translucent member and the reflection light reflected from the light translucent member enters; an exiting face where the reflection light exits to the detection unit; and a light guiding portion through which the exiting light and the reflection light proceed. The detection face has curvature corresponding to curvature of the light translucent member.

Claims

1. A light guide member useable for an object detection apparatus, the object detection apparatus including a light source unit, and a detection unit for detecting an object adhered on a surface of a light translucent member, configuring a vehicle, based on change of light quantity of reflection light received from the light translucent member when light exiting from the light source unit is reflected from the light translucent member, the light guide member comprising:

an incident face where the light exiting from the light source unit enters;

a detection face where the exiting light exits to a rear face of the light translucent member and the reflection light reflected from the light translucent member enters;

an exiting face where the reflection light exits to the detection unit; and

a light guiding portion through which the exiting light and the reflection light proceed,

wherein the detection face includes an intervening member and has curvature corresponding to curvature of the light translucent member, and

wherein the detection face includes a region where the reflection light passes through, the region including a center of the curvature.

2. The light guide member of claim 1, wherein the detection face has the curvature along a long side direction at an area of the detection face where the reflection light passes through.

3. The light guide member of claim 1, wherein the light source unit includes a plurality of light emitting points arranged in a direction corresponding to a vehicle width direction of the vehicle, and the detection face has the curvature along a direction corresponding to the vehicle width direction.

4. The light guide member of claim 1, wherein the curvature of the detection face is smaller than the curvature of the light translucent member facing the detection face.

5. The light guide member of claim 1, wherein the curvature of the detection face matches curvature of an inner face of the light translucent member facing the detection face.

6. The light guide member of claim 1, wherein the detection face is attachable to the light translucent member via an intervening member.

7. The light guide member of claim 1, wherein the light translucent member is a windshield, and the object to adhere on a surface of the windshield is raindrop.

8. The light guide member of claim 1, wherein the detection unit is an image capturing element.

9. An object detection apparatus for detecting an object adhered on a surface of a light translucent member configuring a vehicle, comprising:

a light source unit;

the light guide member of claim 1 used for guiding light exiting from the light source unit to the light translucent member; and

a detection unit to detect an object adhered on the surface of the light translucent member based on change of light quantity of reflection light received from the light translucent member when light enters the light translucent member via the light guide member, passes through the light translucent member, and then reflects on the surface of the light translucent member.

10. A vehicle comprising:

the object detection apparatus of claim 9 that detects an object adhered on a surface of a light translucent member of the vehicle.

11. The light guide member of claim 1, wherein the light guide member is tapered, and the tapered light guide member is disposed on the light source unit, and wherein light emitted from the light source unit is directed in a desired direction through the tapered light guide member.

12. The tapered light guide member of claim 11, wherein the tapered light guide member includes a taper rod lens.