Erwin Sick Gmbh Optik-elektronik

Steinheil Optronik Gmbh

Karl Pietzsch

Matthias Erdmann

Johann Schweiger

Christoph Thoma

Klaus Weber

Klaus Ostertag

Herbert Pettinger

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).

Infrared objective

The invention relates to an infrared objective (IR objective) with a lens arrangement for the production of an infrared image on a detector element of infrared detector equipment. In this respect it may be a question of a focal plane array (FPA) within a Dewar vessel with an internal cold shield for substantially preventing access of thermal radiation from the surroundings (spurious light fractions). The internal cold shield is placed behind an external uncooled cold shield comprising several staggered external cold diaphragms. In this respect the external cold shield is partly arranged in front of and/or partly within the lens arrangement, the external cold shield with the lens arrangement being so designed and so arranged in relation to the internal cold shield that each optical ray, which comes from the lens element and is outside the optical pupil, is reflected back via the external cold shield and the lens arrangement into the or, respectively, on the internal cold shield, one of the cold diaphragms constituting the aperture diaphragm. The infrared objective may be designed telecentrically. The infrared objective may be a component of a complex infrared optical system (for instance as a front afocal).

A method and also an apparatus is described for the direct optical detection of the roughness profile of the material surface (10) in which a light bead (14) is generated on the material surface (10) and the reflected light is passed to a light receiver arrangement (16). The angle of reflection of the reflected light and thus the respective surface inclination value is determined for each scanned point of the material surface (10). To determine the angle of reflection the direction of the center of gravity of the scattered reflected light is formed in each case. The desired roughness profile is subsequently reconstructed from the inclination values that are obtained.

Method and apparatus for the optical detection of the roughness profile

An optical scanning apparatus for transparent, substantially flat material comprises a light source (21) and a mirror wheel (22) illuminated by the light beam. The mirror wheel generates a scanning beam which executes a periodic scanning movement in a scanning plane extending obliquely to the surface of the material. The scanning beam generates a scanning light bead on the surface of the material with the scanning light bead moving along a scanning line. A photoelectric light receiving device is arranged at the angle of reflection. The plane of incidence (11) is arranged at the Brewster angle relative to the normal (12) to the surface of the material (13) The light of the scanning beam (14) which executes the periodic scanning movement in the scanning plane (11) is linearly polarized parallel to the surface of the material or perpendicular to the scanning plane (11).

Optical scanning apparatus for detecting faults in transparent material

A light curtain apparatus is described which does not require a mechanically moving light deflecting element such as a mirror wheel. Instead a number of diodes (11') are arranged in a row (11) and are sequentially energized so that light from each diode in turn passes through an objective lens (12) and an aperture diaphragm and falls on a strip-like concave mirror (14). The diode row is arranged at the focal plane of the objective (12) so that the light emerging from the objective (12) is essentially parallel light. The aperture diaphragm is located in the focal plane of the strip-like concave mirror so that the parallel light emerging from it is reflected at the strip-like concave mirror (14) in a direction parallel to the optical axis (19) and focussed in a plane corresponding to the plane of the aperture diaphragm (20) which is also the focal plane of individual lenses (16') arranged in a row within the image space of the strip-like mirror (14). Thus the light emerging from the individual lenses (16' ) of the lens row (16) is a parallel beam of light (17) which appears to be continuously displaced parallel to itself as a result of the sequential energization of the diodes. At the far end of the monitored region (18) the parallel light can either be detected by a detector (25) located there or returned by a retroreflector (24) back to a photoreceiver (27) located between the strip-like concave mirror (14) and the aperture diaphragm (20).

Light curtain with periodic light transmitter arrangement

In a scanner for the optical checking of objects such as CD-discs there is provided a coherent light source; a light deflecting device which allows a light beam emitted from the light source to sweep over the object in a substantially linear scanning movement, with the optical axis of the light beam subtending a small angle with a normal to the object surface transverse to the scanning direction; and a detector for detecting light which is reflected back from the object. In the present arrangement the optical axis of the light beam also subtends a small angle with the normal to the object surface in the scanning direction. This makes it possible to avoid disturbing modulation of the detector signal due to interference effects.

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Geretsried, Germany

Karl Pietzsch