Detector of stains on a transparent plate surface
First Claim
1. A detector of stains for the surface of a transparent plate that has two parallel, opposite faces, an internal face and an external face, the detector, arranged on the internal face of the plate, and including emitting means for emitting a modulated light signal in the direction of the interior of the plate and a receiving means for receiving the signal after the signal has been reflected on the external face of the plate, characterized by also containing an optical unit, made of a material with an index higher than one and transparent to the modulated light signal, the optical unit placed on the internal face of the plate and including at least two deflection faces for the light signal in order to form a trajectory included between the emitting means and the receiving means, and a bottom interface with the internal face of the plate across from a optical coupling means and by deviation means from the signal of the emitting means, so that the signal reflects a first time on the external face of the plate according to a direction included in an initial incidence plane and the deviation means of the signal towards the receiving means, the deflection faces successively orienting the signal towards the external face in at least one incidence plane non-parallel to the initial incidence plane so that the trajectory of the light signal between the emitting means and the receiving means creates at least two reflections on the external face of the plate across from the optical coupling means without reflection on the internal face of the plate.
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Accused Products
Abstract
A detector of stains on a transparent plate surface is arranged on an internal surface of the plate and includes an emitter for emitting a modulated light signal towards the inside of the plate and a receiver for receiving the signal after it has been reflected on an external surface of the plate. An optical unit made with a material having an index substantially higher than the plate, is arranged on the internal surface of the plate. The optical unit is made up of at least three faces returning the light signal and an interface with the internal surface of the plate through an optical coupler. A deflector deflects the signal from the emitter toward the plate and from the optical unit towards the receiver. At least two reflections on the external surface of the plate are produced through the optical coupler without reflection on the internal surface of the plate.
17 Citations
22 Claims
- 1. A detector of stains for the surface of a transparent plate that has two parallel, opposite faces, an internal face and an external face, the detector, arranged on the internal face of the plate, and including emitting means for emitting a modulated light signal in the direction of the interior of the plate and a receiving means for receiving the signal after the signal has been reflected on the external face of the plate, characterized by also containing an optical unit, made of a material with an index higher than one and transparent to the modulated light signal, the optical unit placed on the internal face of the plate and including at least two deflection faces for the light signal in order to form a trajectory included between the emitting means and the receiving means, and a bottom interface with the internal face of the plate across from a optical coupling means and by deviation means from the signal of the emitting means, so that the signal reflects a first time on the external face of the plate according to a direction included in an initial incidence plane and the deviation means of the signal towards the receiving means, the deflection faces successively orienting the signal towards the external face in at least one incidence plane non-parallel to the initial incidence plane so that the trajectory of the light signal between the emitting means and the receiving means creates at least two reflections on the external face of the plate across from the optical coupling means without reflection on the internal face of the plate.
Specification