The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 16, 1998
Filed:
Jan. 08, 1997
Georg Ankerhold, Lubeck, DE;
Ralf Buchtal, Lubeck, DE;
Dragerwerk AG, Lubeck, DE;
Abstract
A laser diode gas sensor for the spectroscopic measurement of a gas sample, with a retroreflector and a concave mirror, which define between them an open measuring path with the gas to be analyzed. Laser light passes through the measuring path, is reflected at the retroreflector, and is directed toward a detector via a concave mirror in order to determine the mean concentration of the gas component to be analyzed in the optical measuring path. Optical elements, such as beam splitters, lenses, etc., which lead to losses of intensity, were used before to couple the laser light into the beam path onto the retroreflector, and to decouple the reflected light to the detector. An improved optical imaging array, which minimizes losses, is provided. The concave mirror is provided centrally with an opening transparent to the laser light, through which a weakly divergent bundle of laser light is directed onto the retroreflector, so that the retroreflector is illuminated essentially over its entire surface. The retroreflector is made with a matrix consisting of a plurality of triple mirrors, which reflect the incident, weakly divergent bundle of laser beams as a bundle of laser beams with convergent properties onto the concave mirror. The concave mirror is arranged or shaped such that the laser light reflected by the retroreflector is focused by the concave mirror directly onto the detector, which is arranged outside the principal beam path.