Abstract: A mount for optical lens elements or the like, with a retaining ring arranged in a mount body and holding a lens element in the mount. To obtain uniform contact pressure in the lens element and avoid exertion of a torque during mounting of the retaining ring in the mount body, openings are provided along an outer peripheral zone of the retaining ring, with the openings penetrating in the preferably cylindrical peripheral surface of the retaining ring. Setscrews oriented parallel to the element axis are located in the openings to be rotatable and held toward the lens element. The setscrews enter into the mount body with their thread zone projecting out of the peripheral surface of the retaining ring.

Abstract: A device for deviating a bundle of light rays into a plane comprises a deflecting prism of constant deviation rotatable about an axis. The deflecting prism is a Wollaston type quadrangular prism having two prism faces forming a right angle therebeween and having an axis of rotation oriented substantially perpendicularly to one of the two prism faces having the right angle therebetween.

Abstract: A mount for an optical element such as a lens element wherein the optical element has a cylindrical circumferential rim and at least three ribs formed of a material having a highly elastic property. The ribs have a predetermined length and are disposed at a predetermined distance from one another along the cylindrical circumferential rim of the optical element with each rib having an inner periphery in continuous contact with an outer periphery of the cylindrical circumferential rim of the optical element. The ribs are compressed on assembly of the optical element into the mount so that centration of an optical system, e.g., the lens, is substantially improved.

Abstract: A phototropic multilayered glass sheet incorporating at least two interfacially laminated layers, one layer consisting of a nonphototropic carrier glass, and at least one other layer consisting of a phototropic glass. In manufacture, at least one of the glass streams is characterized by having a viscosity of less than 10.sup.7.6 d PAS at the location where the streams are brought together.