Multi-mode rain sensor
First Claim
1. An optical rain sensor for efficiently detecting moisture on a vehicle window having a thickness between 4-12 mm and a corresponding infrared radiation transmission comprising:
- an optical coupler into which optical elements are molded, wherein the optical elements comprise a plurality of lens segments for directing infrared rays, and further wherein, the optical coupler is mechanically and optically coupled to a major surface of the vehicle window having a thickness T, and infrared radiation transmittance Tir;
a housing detachably mounted to the coupler;
a circuit board mounted within the housing and being substantially parallel to the vehicle window; and
electronic components mounted on the circuit board comprising at least two emitters of infrared radiation each producing rays over a 180°
hemisphere substantially normal to the circuit board and at least two detectors of infrared radiation each detecting rays over a 180°
hemisphere substantially normal to the circuit board;
the plurality of lens segments being integrally molded into the optical coupler proximate, and at a height above, each of the at least two emitters and at least two detectors, whereby infrared rays emitted from the at least two emitters are collimated, and then directed, nonsequentially, in one or more of at least four optical paths by the plurality of lens segments through the vehicle window and back to the at least two detectors, wherein the specific optical path followed by the infrared radiation is dependent on T and Tir.
1 Assignment
0 Petitions
Accused Products
Abstract
The present invention relates to a rain sensor that adaptively functions in a variety of different modes when deployed on vehicle windows of different thicknesses and compositions. The arrangement of multiple lens segments and reflecting surfaces in a nonsequential configuration allows utilization of a greater proportion of light rays from the at least two emitters. Further, a greater portion of the light rays emitted by the at least two emitters is captured by the lens segments and reflectors arranged about at least two detectors, and directed to the detectors. Connection to analytical circuitry then allows interpretation of electrical signals, which in turn control, for example, window wiper systems.
20 Citations
19 Claims
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1. An optical rain sensor for efficiently detecting moisture on a vehicle window having a thickness between 4-12 mm and a corresponding infrared radiation transmission comprising:
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an optical coupler into which optical elements are molded, wherein the optical elements comprise a plurality of lens segments for directing infrared rays, and further wherein, the optical coupler is mechanically and optically coupled to a major surface of the vehicle window having a thickness T, and infrared radiation transmittance Tir; a housing detachably mounted to the coupler; a circuit board mounted within the housing and being substantially parallel to the vehicle window; and electronic components mounted on the circuit board comprising at least two emitters of infrared radiation each producing rays over a 180°
hemisphere substantially normal to the circuit board and at least two detectors of infrared radiation each detecting rays over a 180°
hemisphere substantially normal to the circuit board;the plurality of lens segments being integrally molded into the optical coupler proximate, and at a height above, each of the at least two emitters and at least two detectors, whereby infrared rays emitted from the at least two emitters are collimated, and then directed, nonsequentially, in one or more of at least four optical paths by the plurality of lens segments through the vehicle window and back to the at least two detectors, wherein the specific optical path followed by the infrared radiation is dependent on T and Tir. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A moisture sensor for mounting on a first inner surface of a windshield having a thickness T, for detecting water on a plurality of sensing areas on a second outer surface of the windshield, the moisture sensor comprising:
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a) a coupler having a mounting surface and an integrally molded multi-functional optical surface, mountable on the first surface of the windshield; b) a housing detachably secured to the coupler; c) a planar circuit board secured in the housing and having a device surface which is disposed substantially parallel to the first surface of the windshield; d) a first emitter for emitting light rays, the first emitter being mounted on the device surface of the circuit board, disposed at a first corner of a square; e) a second emitter for emitting light rays, the second emitter being mounted on the device surface of the circuit board, disposed at a second corner of the square, opposite the first corner; f) each of the first and second emitters producing rays over a 180°
hemisphere substantially normal to the circuit board having identical emitter groups of optical elements for guiding light rays nonsequentially into the windshield, each emitter group comprising;(i) two collimator lenses for collimating light; and (ii) two folder lens structures for redirecting light; g) a first detector mounted on the device surface of the circuit board and disposed at a third corner of the square, for receiving light rays along a first optical path from the first emitter, and for receiving light along a second optical path from the second emitter; h) a second detector mounted on the device surface of the circuit board and disposed at a fourth corner of the square, for receiving light rays along a third optical path from the first emitter, and for receiving light along a fourth optical path from the second emitter; and i) each of the first and second detectors detecting rays over a 180°
hemisphere substantially normal to the circuit board, comprising identical receiver groups of optical elements adjacently disposed, each receiver group being identical in form to the emitter groups, and comprising;(i) two focuser lenses for focusing light; and (ii) two folder structures for receiving light; wherein, with regard to each of the first, second, third and fourth optical paths, a light beam following one of such paths is dependent on windshield thickness T and the infrared radiation transmittance Tir of the windshield. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19)
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Specification