Illumination for the detection of raindrops on a window by means of a camera

• US 9,720,132 B2
• Filed: 12/19/2013
• Issued: 08/01/2017
• Est. Priority Date: 01/11/2013
• Status: Active Grant

• Current Assignee: Conti Temic Microelectronic GmbH (Continental AG)
• Original Assignee: Conti Temic Microelectronic GmbH (Continental AG)
• Inventors: Krkel, Dieter, Randler, Martin, Fey, Wolfgang
• Primary Examiner(s): Sohn, Seung C
• Application Number:
  US14/437,632
• Publication Number:
  US 20150276982A1
• Time in Patent Office: 1,321 Days
• Field of Search: 250227, 250 29, 250 25
• CPC Class Codes: B60S 1/0844 including a camera
• CPC Class Codes: G01N 2021/435 Sensing drops on the contact surface
• CPC Class Codes: G01N 21/17 Systems in which incident light is modified in accordance with the properties of the material investigated where the material investigated is optically excited causing a change in wavelength of the incident light G01N21/63
• CPC Class Codes: G01N 21/43 by measuring critical angle
• CPC Class Codes: G01W 1/14 Rainfall or precipitation gauges measuring volume in general G01F

Abstract

A device for detecting rain includes a camera and a lighting source for emitting visible light onto a window. The camera and the lighting source are configured and arranged in such a way that the camera can detect a signal of the visible light which the lighting source emits onto the window. The signal which is detected by the camera correlates with visible light of the lighting source, which visible light is reflected or scattered at the inner face of the window or outer face of the window and/or at the raindrop. The visible light passes through a shutter device which causes the light to be blocked or highly attenuated in a predefined direction perpendicular to the illumination direction of structures of the shutter device. In contrast, the light in the direction perpendicular to the predefined direction and to the illumination direction can propagate virtually unimpeded through the shutter device.

Claims

1. A device for detecting rain on a window of a vehicle, the device comprising:

a camera;

a lighting source for emitting visible light in an illumination direction onto a window of the vehicle; and

a shutter device having a grille with a plurality of slats between the lighting source and the window, the slats directing the visible light in the illumination direction onto the window while blocking or attenuating the visible light in directions other than the illumination direction,

wherein the camera and the lighting source are configured and arranged in such a way that the camera can detect the visible light which the lighting source emits onto the window.

2. The device according to claim 1, wherein the window is the windshield of a vehicle and wherein the predefined direction is perpendicular to the illumination direction and perpendicular to the longitudinal direction of the vehicle.

3. The device according to claim 1, further comprising a view funnel, wherein the shutter device is arranged on the view funnel or is integrated into the view funnel.

4. The device according to claim 3, wherein the structures of the shutter device are arranged so that they are adapted to the geometry of the surface of the view funnel.

5. The device according to claim 1, wherein the structures of the shutter device are arranged parallel to one another.

6. The device according to claim 1, wherein adjacent structures of the shutter device are arranged at a distance of less than 100 μ

m apart.

7. The device according to claim 1, wherein adjacent structures of the shutter device are arranged at a distance in the range of 0.1 mm to 1 mm apart.

8. The device according to claim 1, wherein the height of the structures is approximately equal to the distance between the structures of the shutter device.

9. The device according to claim 1, wherein the shutter device is configured in such a way that the distance between adjacent structures and/or the width of the structures varies periodically.

10. The device according to claim 1, wherein a light guide is arranged on the lighting source.

11. The device according to claim 10, wherein the shutter device is arranged on the light guide.