Abstract: Two very thick plano-convex lenses with a common axis are positioned with their convex surfaces facing each other, and a radiation source and the input face of a fiber are each disposed on one of these surfaces in the vicinity of the axis.The main feature of the device resides in the considerable thickness of the lenses relative to the radii of curvature of the dioptric faces. As a result, aberrations, in particular spherical aberrations, are reduced while the dimensions of the device are such as to enable easy construction and handling.

Abstract: A television camera tube having a semiconductor target which on the side to be scanned by an electron beam comprises a mosaic of electrically conductive regions each determining a picture element and separated from the semiconductor plate by an electrically insulating layer, and a resistive layer extending over the mosaic and the insulating layer which contacts the semiconductor surface via an aperture in the insulating layer present in each picture element and has a RC time between the scanning time of a picture element and the scanning time of the whole target.

Abstract: A magnet system for compensating the frequency difference between the oscillator frequency f.sub.o of a YIG oscillator and the central filter frequency f.sub.mi of a YIG filter to be independent of the oscillator frequency in which two pole-pieces are provided having opposing surfaces, one which has a raised portion, and one of which has a plate of magnetic material having a saturation magnetization smaller than the smallest field strength desired. The raised surface portion of the pole-piece has a height at which the frequency f.sub.o -f.sub.mi is independent of f.sub.o.

Abstract: A field emission device and method of forming same, comprising a substrate on which at least one conical electrode is provided, which substrate, with the exception of the proximity of the tip of the electrode, is covered with a layer of a dielectric material on which a conductive layer is present at least locally, in which in order to form an integrated accelerating electrode the conductive layer extends in the direction of the punctiform tip of the electrode to beyond the dielectric layer and shows an aperture above the tip so that the conductive layer forms a cap-shaped accelerating electrode surrounding the conical electrode.

Abstract: Glass composition pairs which are suitable for processing into fibers with a gradient refractive index profile for use in telecommunication. They consist of GeO.sub.2 B.sub.2 O.sub.3 /SiO.sub.2, alkali oxide which in one composition consists of Li.sub.2 O and/or Na.sub.2 O and in the other composition of Na.sub.2 O and/or K.sub.2 O and other compatible oxides.

Abstract: A camera tube target formed by a radiation-receiving silicon layer which on a side to be scanned by the electron beam has a chalcogen-containing layer having intrinsic conductivity which forms a hetero junction with the silicon layer, the chalcogen-containing layer comprising at least one element of the fourth group of the periodic table of elements in an atomic ratio to the chalcogen component lying between 1:1 and 1:2.

Abstract: A beam splitting prism assembly in which at least some of the prisms are separated by an air gap, optionally connected at the edges through the beam splitting layers by means of strips of a thermo-plastic material.

Abstract: An x-ray diffraction crystal for the analysis of x-rays having a wave-length of 50 Angstroms or greater comprising at least two insoluble monolayers of fatty acids in the form of metal soaps, separated by monolayer pairs of differing metal cation - metal soap or non-cation soaps.Such crystals are formed by alternately raising and lowering a solid substrate through the monolayer-covered liquid surfaces of a bivalent heavy element cation and a bivalent light element cation or cation deleted monolayer.

Abstract: Ion-selective electrode for selectively measuring the concentration of an ion in a solution of a mixture of ions, consisting of an ion-conducting or mixed ion-conducting - electron-conducting matrix material provided with a thin surface coating of a material which is sparingly soluble and which has one ion in common with the matrix material.

Abstract: A device for coupling optical fibers each of which is secured in a capillary tube by means of a cap such that the end of the fiber is situated in one plane with the end face of the cap.The two capillary tubes are arranged one in the prolongation of the other in the boring of a deformable core which can be deformed such that radial and axial forces are exerted on the capillary tubes, with the result that the latter are simultaneously aligned and secured.

Abstract: A color television camera including a plurality of camera tubes and an image registration system in which information is projected, via the beam path of the viewer, to a beam splitting optical system. A registration image is projected onto each of the camera tubes by providing a suitable end face of one of the prisms of the splitting optical system with a reflective layer or by arranging a mirror or a prism at this area.

Abstract: Photolysis of organic mercury compounds in mercury-containing samples to determine mercury therein by means of irradiation with a light source emitting predominantly below 260 nm.

Abstract: A device operating with the displacement of magnetic domain walls and comprising a layer of a magnetizable material having an easy axis of magnetization perpendicular to the plane of the layer, in which layer magnetic domain walls can be produced, maintained and moved, as well as a device to cause a magnetic propulsive field to act upon magnetic domains present in the layer so as to move them between previously determined positions. In order to obtain maximum speeds, the propulsive field acting upon a domain wall during the movement should at any instant have a value which is below the value for which a drop occurs in the function which characterizes the magnetizable material and which represents the relation between the propulsive field and the speed.

Abstract: A diffractometer for acquiring crystallographic data from single crystal having means to mount the crystal in the path of a beam of x-rays, a moveable detector and means to constrain the detector to move on an arc which rotates about a horizontal axis so that the detector is sequentially positioned along a line of the reciprocal lattice of the crystal.

Abstract: A device for examining a body section by means of x-radiation including a plurality of detectors arranged to intercept radiation passing through the body in straight lines or strips and a calculating circuit which interpolates, on the basis of absorption values measured, absorption values which can be expected along sets of mutually extending strips which cross each other at different angles. The absorption in the section of the body can then be calculated in known manner on the basis of these values.

Abstract: A device for connecting optical fibers, the ends of which are provided with cylindrical envelopes of magnetic material which envelop the ends of the fibers and which are rigidly connected thereto. The connection device comprises a magnet having pole-shoes provided with means for guiding the said envelopes in order to position the end faces of the fibers one opposite the other in the air gap formed by the pole-shoes.

Abstract: A method of manufacturing an infra-red detector in which a printed form of lead-out contact pattern is applied to the surface of each infra-red sensitive element. A detector element of infra-red sensitive material is provided having at one major side at least one active surface area defined between spaced contact layers which extend over oppositely located curved edges of the element at said side. The element is adhered via the opposite major side to an insulating substrate having a contact pattern provided thereon. Electrically conductive material is deposited to forming interconnections between the contact layers on the element and adjacently situated end portions of lead-out conductors of the contact pattern.

Abstract: A portable television camera comprises a rigid housing accommodating the optical components, such as an entrance optical system, a color splitting optical system and the pick-up tubes which are arranged to bear on abutment faces which are strictly localized with respect to each other. The strict positioning of these components with respect to each other enables the use of pick-up tubes and an entrance optical system which are comparatively cheap, and combines low weight with good image quality.

Abstract: The invention relates to a device for magneto-optic memories controlled by light and/or heat in an external magnetic field, in which the magneto-optic material of the memory has a photoconductive layer which can be activated by the control beam and which can be controlled by means of electrodes provided thereon via a current or voltage source.

Abstract: In a color television camera system of the type having camera tubes for the production of red, green and blue color signals, contour signals derived from only one of the color signals are added to all of the color signals.