Device for monitoring the state of a window pane
First Claim
1. A device for monitoring the state of a window pane comprising a first optical transmitter which emits a first light beam onto a pane to illuminate a first region of the pane, a second optical transmitter which emits a second light beam onto a pane to illuminate a second region of the pane, at least one optical receiver which receives the light of the first and second light beams modulated by the first and second regions of the pane, respectively, and subsequently generates a reception signal, and an evaluation circuit that evaluates the reception signal to determine the state of the pane at the first and second regions of the pane, characterized in that the transmitters and the receiver are located at a distance from the pane and the evaluation circuit is composed of a discriminator stage which uses the reception signal to derive a first and a second reception signal according to the detected modulated light from at least one first optical transmitter and at least one second optical transmitter, respectively.
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Accused Products
Abstract
A device for monitoring the state of a window pane includes an optical emitter which emits a light beam on to the window pane. The device also contains an optical receiver which detects light of the light beam modulated by the window pane and, as a result, generates a received signal. The emitter and the receiver are arranged at a distance from the window pane. An evaluation circuit evaluates the received signal in order to determine the state of the window pane.
15 Citations
20 Claims
- 1. A device for monitoring the state of a window pane comprising a first optical transmitter which emits a first light beam onto a pane to illuminate a first region of the pane, a second optical transmitter which emits a second light beam onto a pane to illuminate a second region of the pane, at least one optical receiver which receives the light of the first and second light beams modulated by the first and second regions of the pane, respectively, and subsequently generates a reception signal, and an evaluation circuit that evaluates the reception signal to determine the state of the pane at the first and second regions of the pane, characterized in that the transmitters and the receiver are located at a distance from the pane and the evaluation circuit is composed of a discriminator stage which uses the reception signal to derive a first and a second reception signal according to the detected modulated light from at least one first optical transmitter and at least one second optical transmitter, respectively.
- 8. A device for monitoring the state of a window pane including at least one optical transmitter which emits a light beam onto a pane, at least one optical receiver which receives the light of the light beam modulated by the pane and subsequently generates a reception signal, and an evaluation circuit that evaluates the reception signal to determine the state of the pane, characterized in that the at least one optical transmitter and the receiver are located at a distance from the pane, and the device is composed of a plurality of optical transmitters, and the evaluation circuit is composed of a discriminator stage which uses the reception signal to derive a first and a second reception signal according to the detected modulated light from at least one first optical transmitter and at least one second optical transmitter, wherein the first optical transmitters and second optical transmitters are controlled by a pulse signal of a different phase and the discriminator stage is formed of a phase-synchronous demodulator.
Specification