Patent ID: 6265712
Filing Date: 2001-07-24
Classification: G01J

Abstract:
An Infra Red (IR) sensing device comprising:an IR sensor for detecting IR radiation, wherein the IR sensor generates electrical signals in response to and indicative of any IR radiation detected by the IR sensor;an IR opaque enclosure surrounding the IR sensor, the enclosure having an IR transparent window positioned to allow IR radiation from outside the enclosure to fall on the IR sensor;an IR radiator positioned within the enclosure, wherein the IR radiator emits IR radiation, wherein at least a portion of a first IR radiation signal generated by the IR radiator is absorbed by IR-absorbing material on the window, wherein the IR absorbing material emits a return IR radiation signal that is detected by the IR sensor, and wherein the IR sensor generates a first electric signal proportional to the return IR radiation signal; anda processor coupled to the IR sensor for analyzing the electrical signals generated by the IR sensor, wherein the processor receives and analyzes the first electric signal to determine characteristics of the return signal.