Leica Camera Ag

Leica Camera Gmbh

Bellicon Ag

Rolf Crema

Gerhard Kranz

Peter Karbe

Bernd Harand

Joachim K&uuml;hn

Peter Schmidt

Christian Mehr

A lens testing device comprises a holder, fitted on a stand, for mounting a lens specimen, a test object illuminated from the rear, an imaging objective and a detector for evaluating the image of the test object. The imaging objective can be combined with the detector to form a unit. The lens specimen is an objective specimen and the test object is arranged in the focal plane of the objective specimen inside the holder. The imaging objective is a collimator objective and the detector is arranged in the focal plane of the collimator objective. Either the holder or the unit is pivotably supported on the stand and the holder and the unit can be pivoted relative to one another.

Lens testing device

Screw mechanism having a spindle (,) which is secured in the axial direction and has a spindle axis (,&prime;), and a spindle nut (,) which is connected to a slide (,) which can be driven and is guided in the axial direction, a joint being provided between the spindle nut (,) and the slide (,) in order to compensate for relative transverse movements and tilting between the spindle nut (,) and slide (,), said joint being formed symmetrically to the spindle axis (,&prime;) and having two joint axes which are perpendicular to each other, intersect on the spindle axis (,&prime;) and are assigned at one end to the transverse movement of a bearing plate (,), which is connected to the spindle nut (,), and at the other end to the transverse movement of a bearing plate (,), which is connected to the slide (,), and said joint containing an intermediate plate (,) via which the bearing plates (,) are connected pivotably to each other in order to compensate for any tilting of their joint axes. The joint axes are each formed by two balls (,&prime;) which are arranged aligned with one another on opposite sides of the spindle axis (,&prime;), are mounted in mutually opposite prism grooves (,&prime;) in the bearing plates (,) and the intermediate plate (,), and bear against one another under spring pressure (,&prime;).

Helical gear

A one-piece lens hood possesses a frontal surface having an approximately rectangular opening, is axially displaceable via a guide from a position of rest into a working position, and is indissolubly connected to the lens. In the position of rest, the frontal surface of the lens hood terminates flush with the front edge of an accessory mount so that the threaded portion of the accessory mount is readily accessible for screwing in accessories such as filters. A format stop is additionally provided as an integral part of the lens in order to mask out stray light. This can, for example, be formed from a blackened metal foil which is mounted on a front terminal ring of the lens.

Lens hood for a photographic lens

Growing community of inventors

Ehringshausen, Germany

Rolf Crema