Rain sensor

• US 7,236,249 B1
• Filed: 01/08/1999
• Issued: 06/26/2007
• Est. Priority Date: 04/08/1998
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Michenfelder, Gebhard, Roth, Klaus, Riehl, Guenther, Burkart, Manfred
• Primary Examiner(s): STAFIRA, MICHAEL PATRICK
• Application Number:
  US09/673,063
• Time in Patent Office: 3,091 Days
• Field of Search: 356/445, 356/239.1, 356/239.2, 356/239.7, 356/239.8, 3562371-2373, 356/338, 250/345.8, 250/574, 250/577, 250/227.25, 250/239, 250/216, 250/222.1, 250/222.2, 318/444, 318/480, 318/483, 318/487
• US Class Current: 356/445
• CPC Class Codes: B60S 1/0822 characterized by the arrangement or type of detection means
• CPC Class Codes: B60S 1/0833 Optical rain sensor
• CPC Class Codes: B60S 1/0888 characterized by the attachment of the elements in a unit

Abstract

A rain sensor, for motor vehicles in particular, having one measuring distance with at least one transmitter and at least one receiver for electromagnetic waves (light waves), a windshield being arranged in the measuring distance, and the measuring distance influencing the wave propagation between the at least one transmitter and the at least one receiver in such a way that when a coating forms on the windshield, in particular as the result of wetting by precipitation, an output signal sensed by the receiver is changed. It is provided that the optical and electronic components of the rain sensor are mounted in a housing, a light conducting element forming a cover of the housing.

Claims

1. A rain sensor arranged with respect to a measuring distance in which is arranged a windshield, comprising:

a housing;

a light conducting element for joining to the housing, wherein the light conducting element includes a first region having a first color and a second region having a second color that is different than the first color; and

a plurality of optical and electronic components mounted in the housing and including;

at least one transmitter for transmitting an electromagnetic wave, and

at least one receiver for receiving the electromagnetic wave, the measuring distance influencing a wave propagation between the at least one transmitter and the at least one receiver such that when a coating forms on the windshield, an output signal sensed by the at least one receiver is changed.

2. The rain sensor according to claim 1, wherein the rain sensor is used in a motor vehicle.

3. The rain sensor according to claim 1, wherein the coating is a result of wetting by precipitation.

4. The rain sensor according to claim 1, wherein:

the light conducting element forms a base plate of the housing and includes a broad area of connection with the windshield.

5. The rain sensor according to claim 4, further comprising:

a common printed circuit board on which is mounted the plurality of optical and electronic components in accordance with SMD technology.

6. The rain sensor according to claim 5, further comprising:

an integrated connector for an electrical connection to a downstream analysis unit, wherein;

the housing corresponds to a rectangular-shaped sensor housing.

7. The rain sensor according to claim 6, further comprising:

contact pins through which the common printed circuit board is connected to the integrated connector.

8. The rain sensor according to claim 1, wherein:

the rain sensor is cemented to an inside of the windshield.

9. The rain sensor according to claim 8, further comprising:

a transparent film that is self-adhesive on each side thereof and corresponds to a connection between the windshield and the light conducting element.

10. The rain sensor according to claim 1, wherein:

the output signal is provided to a downstream analysis circuit and includes information with respect to an instantaneous degree of wetting of the windshield.

11. The rain sensor according to claim 10, wherein:

at least one of a windshield wiper mechanism and a vehicle lighting system is activated as a function of the output signal.

12. The rain sensor according to claim 1, wherein:

the at least one transmitter includes at least one LED.

13. The rain sensor according to claim 12, wherein:

a first one of the at least one receiver that detects an optical signal emitted by the at least one LED includes a photodiode.

14. The rain sensor according to claim 1, wherein:

the plurality of optical and electronic components includes at least one ambient light sensor.

15. The rain sensor according to claim 14, wherein:

the at least one ambient light sensor includes an aperture angle of approximately 40°

inclined upward with an aperture direction in a direction of travel.

16. The rain sensor according to claim 15, wherein:

the at least one ambient light sensor is sensitive to an ultraviolet light.

17. The rain sensor according to claim 16, wherein:

the ultraviolet light corresponds to sunlight.

18. The rain sensor according to claim 1, wherein:

the first region includes a black plastic.

19. The rain sensor according to claim 1, wherein:

the second region includes a transparent plastic.

20. The rain sensor according to claim 1, wherein:

the first region and the second region are formed according to a two-color injection molding process.

21. The rain sensor according claim 1, wherein:

the first region and the second region correspond to two single-color plastics, and

the light conducting element is formed by combining the two single-color plastics.

22. The rain sensor according to claim 1, wherein:

the light conducting element includes integrated lens structures for light bundling.

23. The rain sensor according to claim 14, wherein:

the at least one ambient light sensor is sensitive to visible light.

24. The rain sensor according to claim 1, wherein:

the light conducting element forms a cover of the housing.

45. The rain sensor according to claim 1, wherein:

the first region includes a black plastic, and

the second region includes a transparent plastic.

25. A rain sensor arranged with respect to a measuring distance in which is arranged a windshield, comprising:

a housing;

a light conducting element for joining to the housing; and

a plurality of optical and electronic components mounted in the housing and including;

at least one transmitter for transmitting an electromagnetic wave,

at least one ambient light sensor that is sensitive to visible light, and

at least one receiver for receiving the electromagnetic wave, the measuring distance influencing a wave propagation between the at least one transmitter and the at least one receiver such that when a coating forms on the windshield, wherein;

an output signal sensed by the at least one receiver is changed the output signal is provided to a downstream analysis circuit and includes information with respect to an instantaneous degree of wetting of the windshield, and at least one of a windshield wiper mechanism and a vehicle lighting system is activated as a function of the output signal.

26. The rain sensor according to claim 25, wherein:

the rain sensor is used in a motor vehicle.

27. The rain sensor according to claim 25, wherein:

the coating is a result of wetting by precipitation.

28. The rain sensor according to claim 25, wherein:

the light conducting element forms a base plate of the housing and

includes a broad area of connection with the windshield.

29. The rain sensor according to claim 28, further comprising:

a common printed circuit board on which is mounted the plurality of optical and electronic components in accordance with SMD technology.

30. The rain sensor according to claim 29, further comprising:

an integrated connector for an electrical connection to a downstream analysis unit, wherein;

the housing corresponds to a rectangular-shaped sensor housing.

31. The rain sensor according to claim 30, further comprising:

contact pins through which the common printed circuit board is connected to the integrated connector.

32. The rain sensor according to claim 25, wherein:

the rain sensor is cemented to an inside of the windshield.

33. The rain sensor according to claim 32, further comprising:

a transparent film that is self-adhesive on each side thereof and corresponds to a connection between the windshield and the light conducting element.

34. The rain sensor according to claim 25, wherein:

the at least one transmitter includes at least one LED.

35. The rain sensor according to claim 34, wherein:

a first one of the at least one receiver that detects an optical signal emitted by the at least one LED includes a photodiode.

36. The rain sensor according to claim 25, wherein:

the at least one ambient light sensor includes an aperture angle of approximately 40°

inclined upward with an aperture direction in a direction of travel.

37. The rain sensor according to claim 25, wherein:

the at least one ambient light sensor is sensitive to an ultraviolet light.

38. The rain sensor according to claim 37, wherein:

the ultraviolet light corresponds to sunlight.

39. The rain sensor according to claim 25, wherein:

where an infrared light is used, the light conducting element is formed of a black plastic.

40. The rain sensor according to claim 25, wherein:

the light conducting element includes optical areas formed from transparent plastic for the at least one receiver.

41. The rain sensor according to claim 25, wherein:

the light conducting element includes a plastic part formed according to a two-color injection molding process.

42. The rain sensor according claim 25, wherein:

the light conducting element is formed by combining two single-color plastics.

43. The rain sensor according to claim 25, wherein:

the light conducting element includes integrated lens structures for light bundling.

44. The rain sensor according to claim 25, wherein:

the light conducting element forms a cover of the housing.