Back to results
US 6,057,550 AGranted
Infrared objective
AssigneeSteinheil Optronik GmbH
InventorsChristoph Thoma, Matthias Erdmann, Johann Schweiger, Karl Pietzsch
Life of this patent
Estimating the term…
Abstract
An infrared radiation detector device has a cooled detector element (3) within a first optical device (internal cold shield (1.sub.i)). The first optical device includes a first diaphragm (6.sub.i) in front of said detector element. The infrared radiation detector device has a second optical device (external cold shield (1.sub.a)) which is thermally separated from the first optical device. The second optical device includes a second diaphragm (6.sub.a). The aperture (7.sub.a) of the diaphragm forms the pupil of the infrared optic which produces an infrared image on the surface of said detector element (3).
Claims14
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 ", of
- k.sub.i =z.sub.i /2h.sub.i
- wherein "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 " of
- k.sub.a =z.sub.a /2h.sub.a
- wherein "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 and
- 1/2k.sub.i =1/2k.sub.a +(1/z.sub.1 -1/z.sub.a)d
- wherein "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).
12 more elements
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 separately arranged from said detector element (3) which forms an image plane on which an image is generated;
- a second optical device (1.sub.i) 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 " of
- k.sub.i =z.sub.i /2h.sub.i
- wherein "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 " of
- k.sub.a =z.sub.a /2h.sub.a
- wherein "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:
- 1/k.sub.opt =2d/z.sub.a +1/k.sub.a and
- 1/2k.sub.i =1/2k.sub.a +(1/z.sub.i -1/z.sub.a)d
- wherein "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);
- and that
- said second optical device (1.sub.a) is arranged asymmetrically with respect to the optic axis (X) of said detector device.
15 more elements
Dependencies are inferred from the claim text.