Optical sensor with light-blocking and light-transmissive surface regions

• US 8,338,774 B2
• Filed: 06/22/2009
• Issued: 12/25/2012
• Est. Priority Date: 07/15/2008
• Status: Expired due to Fees

• Current Assignee: TRW Automotive Electronics & Components GmbH & Co. KG
• Original Assignee: TRW Automotive Electronics & Components GmbH & Co. KG
• Inventors: Backes, Ulrich
• Primary Examiner(s): Legasse, Jr., Francis M
• Application Number:
  US12/488,739
• Publication Number:
  US 20100012824A1
• Time in Patent Office: 1,282 Days
• Field of Search: 250/227.14, 250/227.24, 250/227.29, 250/227.3, 250/222.1, 250/574, 250/227.25, 318/484, 318/444, 340/602
• US Class Current: 250/227.25
• CPC Class Codes: B60S 1/0837 with a particular arrangement of the optical elements
• CPC Class Codes: G02B 3/08 with discontinuous faces, e.g. Fresnel lens diffractive Fresnel lenses G02B5/1876

Abstract

An optical sensor has an optical plate which is adapted to make surface contact on a pane, in particular a windshield of a motor vehicle. It further has one or preferably a plurality of photoreceivers arranged on the side of the optical plate facing away from the pane. An optical mask is arranged in the optical path upstream of each photoreceiver, the optical mask having light-blocking and light-transmissive surface areas. The light-transmissive surface areas each allow an optical path to traverse the optical plate, impinging on the photoreceiver and is delimited by the light-blocking surface areas.

Claims

1. An optical sensor comprising

an optical plate which is adapted to make surface contact on a windshield of a motor vehicle,

a plurality of sensor units having different light directional characteristics being formed by

a plurality of photoreceivers which are all arranged on a side of the optical plate facing away from the windshield and

light-transmissive surface regions of an optical mask which are associated with the photoreceivers and arranged in the optical path upstream of the photoreceivers,

the light-blocking and light-transmissive surface regions being formed in a patterned structure that consists of multiple patterned elements, each having a surface area that is small in comparison with the surface area of the light-sensitive surface of the photoreceivers,

wherein the light-transmissive surface regions expose optical paths delimited by the light-blocking surface regions for ambient light incident on the windshield, traversing the optical plate, and impinging on the photoreceivers, forming two beams of rays each of which is incident on one of the photoreceivers with a smooth curve for the directional characteristic.

2. The optical sensor according to claim 1, wherein the optical plate includes Fresnel lens structures.

3. The optical sensor according to claim 1, wherein the optical mask is arranged between the optical plate and the photoreceivers.

4. The optical sensor according to claim 1, wherein the light-blocking surface regions are formed by an opaque layer from which the light-transmissive surface regions are recessed.

5. The optical sensor according to claim 1, wherein the patterned elements are square.

6. The optical sensor according to claim 1, wherein the optical plate includes first and second surfaces that extend substantially parallel to first and second surfaces of the optical mask, the optical path passing through the first and second surfaces of the optical plate and the first and second surfaces of the optical mask.

7. The optical sensor according to claim 1, wherein the light-blocking surface regions and light-transmissive surface regions of the optical mask are patterned in a grid of squares.

8. The optical sensor according to claim 1, wherein the optical mask has a substantially planar configuration.

9. The optical sensor according to claim 3, wherein the optical mask is applied over an area on a side of the optical plate facing the photoreceivers.

10. The optical sensor according to claim 9, wherein the optical mask is printed on the side of the optical plate facing the photoreceivers.

11. The optical sensor according to claim 9, wherein the photoreceivers are coupled to the optical plate via an optical coupling layer.