Abstract: Thin-film magnetic head including an inductive transducing element (15) and a face (3) for magnetic flux coupling of the transducing element with a magnetic recording medium. A first magnetically permeable layer (5) and a second similar layer (7) together constitute a transducing gap (11). To improve the transducing function a layer (21) of a superconducting material is provided between the layers (5) and (7).

Abstract: A infra-red receiver for use in applications such as remote control of consumer equipment and receiving audio signals modulated on an IR carrier. The receiver comprises an IR diode (10) which is operated in its forward mode so that it constitutes a current source. The IR diode (10) is connected in an amplifying circuit which includes means (16) for detecting low frequency interference components in the signal and in response to the detection of these interference components temporarily shorts out the IR diode.

Abstract: The invention relates to an optical assembly for a camera comprising a color-separation system 1 having three exit windows 3, 4 and 5. A solid-state image sensor 6, 7 and 8 is fixed in a desired position to each exit window 3, 4 and 5 by means of a holder 9, 10 and 11. Each holder 9, 10 and 11 comprises a first holder plate 12, 13, 14 having an aperture 45, 46, 47 and a second holder plate 15, 16, 17 having an aperture 48, 49, 50 and an elastically deformable element 18, 19, 20 which surrounds the apertures of a holder.

Abstract: An infrared radiation sensor is provided comprising an infrared optical system and a pyroelectric radiation detector for receiving infrared radiation from the optical system and generating an output signal. The optical system has a lens (6) arranged to feed source radiation through an aperture (9) into a reflective radiation cavity (10), the lens and the aperture defining a radiation sensitive angular zone width and direction (2,3,4,5) for the sensor. The pyroelectric radiation detector comprises a film (11) of pyroelectric plastics material within the cavity. The film area can be made large within the cavity without affecting the angular resolution of the sensor which is controlled by the ratio of the optical system focal length to the aperture width.

Abstract: Opto-mechanical analyzer using a single polygon (P) comprising n reflective faces which are arranged parallel to the axis (2) of the cylinder in which the polygon is cut and are determined in such a way that their distribution on the periphery is sinusoidal. The polygon rotates about an axis (1) extending at an angle .theta. to the axis (2) and situated in the plane formed by the axis (2) and the axis (X X') on which the diameter of the cylinder extends. On either side of this diameter the reflective faces have been distributed pairwise parallel. The n faces of the polygon thus have n different inclinations with respect to the axis of rotation and the angular pitch is constant.

Abstract: Grooves are etched in a glass substrate, using a metallic mask, after which the substrate is coated with a layer of glass having a refractive index which is higher than that of the substrate, the groove being filled completely. Excess glass is removed, the metallic mask being used as a stop layer and a protective layer being provided at the location of the filled grooves. Excess glass is removed at the location of the grooves by means of polishing so that a high accuracy as regards depth can be obtained.

Abstract: Thin-film transformer suitable for use in a thin-film magnetic head has two magnetically permeable thin layers 3 and 5 primary turn constituted by an electrically conducting which form a magnetic yoke. A layer 13 and a secondary turn constituted by an electrically conducting layer 15 are located in the yoke. A layer 21 of a superconducting material is provided between the layer 3 and the turns, or the turns are closely fitted together and made of a superconducting material themselves.

Abstract: An optoelectronic arrangement having a coupling between an optical transmission fibre and a semiconductor laser diode and with a holder for the optical transmission fibre, while an intermediate part is arranged between the two holders, the intermediate part and one of the two holders being arranged so that they can be slipped one into the other and one of these parts having an annular connection part of reduced thickness, which after axial adjustment of the end of the optical transmission fibre with respect to the semiconductor laser diode is secured to the surface of the other part by means of a number of laser welds, while the intermediate part and the other holder have a flat surface which is at right angles to the direction of axial adjustment, which surfaces engage each other, one of these surfaces having a flange of reduced thickness which after transversal adjustment of the end of the transmission fibre with respect to the laser element is secured to the other surface by a number of laser welds.

Abstract: A thermal-image sensing device is manufactured with a 2-dimensional array of ferroelectric or pyroelectric infrared detector elements (38) mounted on a circuit substrate (1). The upper surface of the circuit substrate (1) is covered with a thick insulating layer (10) of plastics material in which a corresponding 2-dimensional array of bores (11) is formed. Each of the detector elements (38) is connected to a respective electrode (2) of the circuit substrate (1) by means of a metal coating over the wall of its respective bore (11) and over the respective electrode (2) of the circuit substrate (1). The invention permits a simplification in manufacture while forming a device structure with a high degree of ruggedness and good electrical and thermal insulation between the detector elements (38) and the circuit substrate (1).

Abstract: An optical switching element including two optical guides constituted by linear parallel strips coupled through a distance d and made of semiconductor material having an index n.sub.1 on a semiconductor substrate having an index n.sub.o <n.sub.1 and provided with electrodes E.sub.ii to carry out the switching of the light from one guide to the other, characterized in that the first guide G.sub.ii is connected on the one hand to an input IN.sub.i and on the other hand to a direct output I'.sub.i of the switching element, and in that the second guide H.sub.ii is provided beyond the zone of the electrodes E.sub.ii with a flat mirror M.sub.ii at 45.degree. with respect to its optical axis, which reflects the light into a guide H'.sub.ii perpendicular to H.sub.ii, in that H'.sub.ii is coupled through a distance d to a guide G'.sub.ii, the guides H'.sub.ii and G'.sub.ii being provided with electrodes E'.sub.ii to direct the light towards the output O.sub. i of the guide G'.sub.

Abstract: The invention relates to a polarization scrambler comprising a controllable optical phase retardation element for retarding with respect to one another components of a light beam with a different state of polarization, the light beam propagating through the element, and a control arrangement for controlling the phase retardation element, said control arrangement being adapted to supply a control signal so that as a function of time the phase retardation is controlled in such a way that with a given state of polarization (SOP) of the light entering the polarization scrambler varying states of polarization occur at its output in such a way that, averaged in time, the light intensities emerging in each SOP are at least substantially equal.

Abstract: Arranged downstreams of a camera (1) for the serial or parallel-serial analysis of a field of view, the device comprises a digitizing device A/D (2) which serially supplies samples which are coded in parallel over p bits, a digital-to-analog converter D/A (3) and a monitor TV (4). According to the invention, the device furthermore includes, arranged between the A/D (2) and the D/A (3) a line memory (11) comprising an integral number N of lines, which serves as a buffer memory between the lines entering at the variable rate of the optomechanical analysis lines and the lines outputted at the fixed rate of the TV lines. The number N is chosen to be substantially equal to the instantaneous maximum possible shift of the number of lines between the analysis and their recovery. A picture clock pulse generator supplies the synchronizing signals, of the TV standard, necesssary for the analyser of the camera and for the line memory. Use: picture sensors with optomechanical analysis.

Abstract: A method of and a device for manufacturing an optical fiber with a protective coating. A cooling device cools the fiber after drawing from a preform. The cooling device comprises a forced-cooled double-walled tube. In the space enclosed by the inner tube through which the fiber to be cooled is passed, a gas is present which has good heat-transporting properties. The gas may be, for example, helium. Cooling of the fiber takes place by heat dissipation via the helium to the forced-cooled tube wall.

Abstract: An illumination system for an LCD projection display system to increase the brightness of the system. The system includes a polarizing beam splitter which splits a beam of light from a light source into two orthogonally polarized beams. The beam of the desired polarization direction is directed through a first face of a prism so that it reflects off of a second face of the prism and exists through a third face. The other beam of the non-desired polarization direction is passed through a device for rotating its polarization 90.degree. and towards the underside of the second face of the prism at an angle such that it is refracted into the prism. Both beams then exit the prism through its third face, have the same polarization direction, and are only slightly divergent. The recombined beam may be thereafter directed towards the light modulation system. The illumination system minimizes the number of air-glass interfaces and the number of reflecting surfaces.

Abstract: Anamorphotic optical system transmitting an image while deforming it in one direction and leaving it undeformed in a substantially perpendicular direction. It comprises a main fibre-optical image guide (210) cemented to an exit face (213, 213.sub.2) of at least one beveled supplementary fibre-optical guide (220, 220.sub.2), the axes of the optical fibres of the two guides (210, 213, 213.sub.2) being not parallel to one another. Thus, the magnification of the image is not uniform in the direction of deformation. The transmitted image has either at least two parts each representing a different magnification, or a progressive deformation in the direction of the deformation.

Abstract: In a multilayer capacitor, which is made of alternate layers 1 of a dielectric oxidic ceramic material and an electrode material 2, and which is provided with metallic end contacts 4 which electrically conductively contact a prescribed part of the layers of electrode material via an intermediate layer 3 of a conductive metal oxide, the metallic end contacts containing silver, the diffusion of silver from the end contacts to the layers of electrode material is suppressed effectively in that the intermediate layer is a heterogeneous layer which, apart from the conductive metal oxide, contains glass particles, and in that the heterogeneous layer has a thickness of at least 1 .mu.m. On account of this, the end contacts can readily be manufactured from a paste, and delamination, cracking and the formation of cavities in the viscinity of the end contacts are suppressed.

Abstract: This varifocal optical system is electro-mechanically controlled to vary focal distance, temperature correction focussing and finite distance focussing. It is constituted by four single lenses (L1, L2, L3 and L4) two of which (L2, L3) are movable and are axially translated to vary the magnification, while only one (L3) of these two lenses is adapted for temperature correction focussing and finite distance focussing. It is also consituted by electro-mechanical member (EMM) which are especially adapted to control the movements of the two movable lenses (L2, L3) in a discrete manner.

Abstract: Thin-film magnetic head including a magnetoresistive element (1) and a face (9) for magnetically coupling the element with a magnetic recording medium. A magnetic yoke constituted by three layers (3, 5, 7) of a magnetically permeable material has a gap (13) which is bridged by the magnetoresistive element. A layer (15) of a superconducting material for improving the efficiency of the magnetic head is provided between the layers (3) and (5) and the element (1) on the one hand and the layer (7) on the other hand. For protection from external disturbing magnetic fields and reduction of stray flux a layer (43A, 43B, respectively) of a superconducting material is provided on the layers (3) and (5) and under the layer (7).

Abstract: A damping material (19) is provided on one of the two side faces (7, 8), of a magnetic head having two plate shaped ferrite core limbs (3, 4). The material consists of a synthetic resin filled with less than 30% by volume of filler having a density of more than 10.times.10.sup.3 kg/m.sup.3. The filler is at least 74% by weight of the damping material and the density of the damping material is larger than 4.times.10.sup.3 kg/m.sup.3 and its modulus of elasticity ranges between 10.sup.7 and 10.sup.9 Pa.

Abstract: A method of forming an integrated circuit for the detection of infrared radiation comprising a semi-isolating substrate provided with a buried PIN photodiode, with a junction field effect transistor J-FET, whose gate is connected to the PIN photodiode, and with a resistor R connected to the transistor, this method including the growth of a first structure of epitaxial layers of semiconductor materials, in which the J-FET transistor is formed, the growth of a second structure of epitaxial layers of semiconductor materials, in which the PIN diode is formed, and the step of etching a pit, in which the second structure of layers is formed, characterized in that the step of etching the pit is effected after the growth of the first structure of epitaxial layers and is carried out through this structure down to the substrate, in that the growth of the second structure of epitaxial layers is localized in such a manner that this second structure is limited to the pit and in that its upper surface is copolanar with tha