Intra-optical light beam sighting system for an infrared thermometer
Patent 4494881 Issued on January 22, 1985. Estimated Expiration Date: March 10, 2002. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
374/124, With scanning or temperature distribution display250/353, With beam deflector or focussing means356/72, WITH PLURAL DIVERSE TEST OR ART374/120, In spaced noncontact relationship to specimen374/130, Optical system structure (e.g., lens)374/141Combined with diverse art device
A sighting system primarily for use with infrared thermometers and that provides a visible light beam, the geometry of which is congruent with the field of view of the infrared optics of the thermometer to provide the user with an accurate representation of the intersection of the field of view cross-section of the object of which the temperature is being measured by the thermometer. Two novel embodiments are disclosed, one of which utilizes Fresnel lenses and one of which utilizes a Cassegrainian lens system. Both embodiments provide means for accommodating an isolated visible light source and passage of the visible light generated therefrom through the identical lens system used by the infrared detector to develop the signal indicative of the infrared energy and therefore temperature generated by the object to which the infrared thermometer is directed.