Patent ID: 6057550
Filing Date: 2000-05-02
Classification: G01J,G02B,H01L

Abstract:
An infrared radiation detector device comprising:a cooled detector element (3);a first optical device (1.sub.i) for screening off said detector element (3) from infrared radiation;said first optical device having a first radiation entry diaphragm (6.sub.i) with a first aperture (7.sub.i) and a cooled wall opposed to said first aperture and supporting said detector element (3) which forms an image plane on which an image is generated;a second optical device (1.sub.a) placed in front of said first optical device (1.sub.i) in direction of light propagation and thermally separated from said first optical device (1.sub.i);said second optical device having a second radiation entry diaphragm (6.sub.a) with a second aperture (7.sub.a), characterized in that said second aperture (7.sub.a) of said second radiation entry diaphragm (6.sub.a) is an exit pupil of an infrared optic for producing said image;said first optical device (1.sub.i) having a first radiation entry aperture ratio ""k.sub.i "", ofk.sub.i =z.sub.i /2h.sub.iwherein ""z.sub.i "" denotes a first distance of said image plane from said first aperture (7.sub.i) and ""h.sub.i "" denotes a marginal height of said first aperture (7.sub.i);said second optical device (1.sub.a) having a second radiation entry aperture ratio ""k.sub.a "" ofk.sub.a =z.sub.a /2h.sub.awherein ""z.sub.a "" denotes a second distance of said image plane from said second aperture (7.sub.a) and ""h.sub.a "" denotes a marginal height of said second aperture (7.sub.a); and the following conditions are met:1k.sub.opt =2d/z.sub.a +1/k.sub.a and1/2k.sub.i =1/2k.sub.a +(1/z.sub.1 -1/z.sub.a)dwherein ""d"" denotes one half of an overall diameter of said detector element (3), and k.sub.opt denotes the aperture ratio in a case of minimum optical aperture of said second optical device (1.sub.a).