Abstract: An active matrix display device comprises an array of display elements (12), e.g. liquid crystal display elements, connected between sets of row and column address conductors (22,24). A display element electrode (20) is connected to an associated address conductor (22) of one set via two, parallel, switch means each of which comprises at least two, two-terminal, bi-directional, non-linear devices (30), for example, MIM type thin film diode devices, connected in series. A bidirectional, non-linear device (e.g. 30b) of each switch means (e.g. 30a, 30b) is shared by, and comprises a part of, a switch means (e.g. 30b, 30e) associated with a respective adjacent display element, there being in each switch means at least one non-linear device (e.g. 30a) between the shared device (30b) and the display element electrode (20).

Abstract: A reflecting image projection screen (1) is described, as well as an image projection system (17) in which such a projection screen (1) is used. Viewed from the front side (3) of the projection screen (1), the image projection screen comprises, in this order, a linear polarizer (9), a .lambda./4 plate (11), a reflecting polarizer (13) in the form of a cholesteric filter and a reflecting layer (15) which is also active as a depolarizing diffuser layer. By combining a cholesteric filter (13) with a depolarizing reflecting layer (15), an image projection screen is obtained which is highly reflective to the direction of polarization supplied by the image projector (19) and substantially absorbs the other direction of polarization.

Abstract: A low-power cathode can be obtained by arranging it on a substrate (1), preferably of silicon, which is entirely or partly removed at the location of the emissive structure (11) by means of, for example, anisotropic etching. Because of its low power, the cathode is particularly suitable for multi-beam applications.

Abstract: A thin-film magnetic head is situated on a carrier (2) on which an electrically conducting plating-base (2) is provided on which by electroplating flux conductors and a magnetically insulating layer (8) are grown. This provides a planar structure on which an electrically insulating layer and a magneto-resistance element are provided. The plating-base also constitutes the gap layer.

Abstract: A novel type of lead-free glass for use in glass components of electric lamps, such as stems (1) for incandescent lamps and fluorescent lamps and lamp envelopes for compact fluorescent lamps. The glass does not contain PbO, F and B.sub.2 O.sub.3. The glass has favorable physical properties as regards meltability, softening, expansion, electric resistance, transparency, strength and chemical resistance.

Abstract: A rechargeable electrochemical cell having a negative electrode, whose electrochemically active material comprises an intermetallic compound having the CaCu.sub.5 -structure which forms a hydride with hydrogen, obtains a high loadability and a long life cycle by virtue of the fact that the intermetallic compound comprises a non-stoichiometric metastable phase. The intermetallic compound is, preferably, of the type having the composition AB.sub.m, where m exceeds 5.4.

Abstract: A method for making an optically readable medium containing a relief information track comprising the sequential steps of(a) laminating a dry photohardenable film to a surface of a transparent dimensionally stable substrate;(b) embossing the exposed surface of the photohardenable film with the relief information track by applying thereto under pressure a stamper die containing a reverse relief image of the information track;(c) passing actinic radiation through the transparent substrate and the photohardenable film to effect hardening of the photohardenable film while it is contact with the stamper die; and(d) separating the stamper die from the embossed photohardened film;The embossed film of the medium is made reflective by applying a reflective layer to either the photohardenable film prior to embossing or to the photohardened film subsequent to embossing.

Abstract: A semiconductor structure useful in blue light emitting diodes and diode lasers is disclosed. The structure is formed of a substrate of p- type GaAs, a layer of a p- type II-VI compound of the formula Zn.sub.x Q.sub.1-x S.sub.y Se.sub.1-x where Q=Mg, Cd or Mn, 0.5.ltoreq.x.ltoreq.1 and 0.ltoreq.y.ltoreq.1, separated from the substrate by a series of thin epitaxial undoped or p-doped layers including a layer of In.sub.0.5 Al.sub.0.5 P in contact with the layer of the II-VI compound, a layer of In.sub.0.5 Ga.sub.0.5 P or of Al.sub.x Ga.sub.1-x As where x=0.1-0.3 contacting the substrate, a layer of In.sub.0.5 Ga.sub.0.5 P contacting the layer of Al.sub.x Ga.sub.1-x P and at least one layer of In.sub.0.5 Al.sub.2 Ga.sub.0.5-z P where 0<z<0.5 and the value of z decreases in the direction of the layer of In.sub.0.5 Ga.sub.0.5 P provided between and contacting the layer of In.sub.0.5 Al.sub.0.5 P and the layer of In.sub.0.5 Ga.sub.0.5 P.

Abstract: A polycarbonate copolymer of a spirobisindan (6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spirobisindan) and bisphenol-A in which the mole fraction of the spirobisindan .alpha. ranges between 0.844 and 0.887 is provided. Such a copolymer has a stress-optical coefficient C.sub.m in the melt which is equal to zero or substantially equal to zero, so that the sensitivity of the polymer to orientation birefringence is very small. Such a copolymer can be rendered optically isotropic and is very suitable for use in optical components in which birefringence is undesirable. Examples of such optical components are lenses and substrates for optical information media.

Abstract: A magnetic-tape-cassette apparatus, with a detection mechanism in order to handle magnetic-tape cassette types (3, 13) with different tape-recording standards and housing configurations, which detection mechanism senses the cassette side wail (8, 17) having the access openings (8, 17) and comprises a sensing element which upon insertion of a cassette, depending on the cassette type, either moves past this cassette wall (8, 17) or engages a guide profile in order to be positioned before a sliding cover of this cassette type and move said cover so far that the access openings are exposed, the detection mechanism (41) being activated upon insertion of a magnetic-tape cassette in a longitudinal direction in which the tape spools are juxtaposed in that the short side wall which faces forward during insertion moves the sensing pin without the sliding cover at this instant already being urged towards the position in which it exposes the access openings, and as insertion proceeds the sensing pin moves to the long cas

Abstract: A photomultiplier tube in which a photoelectron beam (42) is divided in N independent paths by means of an electron-optical device. The optical device includes a first cup-shaped focusing electrode (25) having a flat bottom portion of polygonal or circular shape, in which N apertures (30a), (30b) are formed, and having raised side faces (28a), (28b) which extend towards the photocathode (12), viewed in the radial directions corresponding to the elementary photomultipliers, and side faces having V-shaped recesses between these directions. The optical device is completed by a deflection electrode (35) which is brought to approximately the same potential as the photocathode and which is centrally arranged close to the bottom portion of the focusing electrode (25). The assembly is followed by a multiplier (16) of the perforated sheet-type whose focusing electrode (161) has projecting portions (41a), (41b), the multiplier being followed by N anode plates (20a), (20b).

Abstract: In a flat display device, for example, a luminescent display a spacer structure (5) is provided between two substrates (1, 3). To this end a mask (9, 15) consisting, if necessary, of a plurality of layers is incorporated in a photosensitive material (8, 13). After exposure, development and removal of the mask, the desired spacer structure is obtained.

Abstract: The invention provides a ceramic body and a method of manufacturing such a body. The body is characterized by its composition, which comprises 20-30 at. % of magnesium, 20-30 at. % of silicon, 40-60 at. % of nitrogen and maximally 15 at. % of oxygen. A preferred composition corresponds to the formula MgSiN.sub.2-x O.sub.x, where x is smaller than 0.5. The manufacture of the ceramic body in accordance with the invention is simpler and cheaper than that of aluminium nitride, and a number of properties of said ceramic material are better than those of the known aluminium oxide.

Abstract: Method of manufacturing a dispenser cathode, in which method tungsten and a scandium-containing material are mechanically alloyed and the product thus formed is pressed into a cathode body. The cathode body is further provided with a barium-containing component. In the mechanical alloying process the tungsten is highly deformed and the scandium-containing material is mixed with the tungsten so as to be very finely distributed therein, so that an improved dispensation of scandium and hence an improved recovery after ion bombardment of the final cathode is attained.

Abstract: The invention relates to a magnetic-tape-cassette apparatus having a deck for playing magnetic-tape cassettes, which comprises a loading mechanism including a cassette holder (23) adapted to receive a magnetic-tape cassette (2) and having a holder wall (23e) which guides a cassette wall and which carries laterally projecting pins (23a/b), which pins are guided in lift slots (22b) in a lift slide (22), which slots are inclined relative to the vertical, to lower the cassette holder (23) into a play position and to lift the holder into an eject position, the lift slots (22b) being formed in a lift wall of the lift slide (22), which is movable between a forward and a backward end position, which carries along the cassette holder (23) over a part of its path of movement, and which is movably guided in a parallel first and a second rail (1f, 1n) on the deck plate of the apparatus, in whichthe first rail (1f) is arranged at the location of the lift wall provided with the lift slots (22b) through which the pins (23a/

Abstract: In an image pick-up and display apparatus comprising a liquid crystal display device (34), an image pick-up device (24) and a partially transparent mirror (36), the display device is arranged at the front side of the apparatus (30), the partially transparent mirror is disposed behind this device (32) in light paths respectively between the display device and the light source (38) for illuminating this display device and between the image pick-up device (24) and the display device (32), so that the received image can be displayed in a natural way and the optical information of a subject in front of the apparatus is not disturbed by light from the light source.

Abstract: A vertical double diffused metal-on-semiconductor device is produced by a method involving the formation of horizontally separated bodies of heavily doped Si and sources by a self-aligned process and a lift-off process along with the formation of trenches having negatively-sloped side-walls.

Abstract: An electro-optic display device with grey scale set by areas of crossing electrodes. In one embodiment, there are 3 strip-shaped sub electrodes with a width relationship of 4:2:1, and two strip shaped column electrodes with a relationship of 8:1. In a second embodiment, there are 4 strip-shaped sub electrodes with a width relationship of 8:4:2:1, and two strip shaped column electrodes with a relationship of 16:1.

Abstract: The method serves for the electroless deposition of a metal layer (7) from a metallization liquid on a top side of a flat article to be metallized, more in particular a flat disc, for example, a master disc (1) which is used for the reproduction of optical discs. According to the method the top side of the article is first made hydrophilic, if so necessary, after which, with the article supported in a horizontal position, a quantity of metallization liquid is provided on the top side which was previously made hydrophilic as a stable liquid layer (16) bounded by the edges of the article, after which the deposition of the metal from the liquid on the article takes place and the liquid layer is the removed entirely from the surface.

Abstract: A conference system comprises speaker units (12) coupled to a central unit (14). The speaker unit (12) comprises an echo canceller (20) with an adaptive filter (38) having an impulse response of comparatively short duration. In a speech pause of the user of the speaker unit (12) the common listening signal (LS) of the conference system is applied to the loudspeaker (18). Of the sounds then picked up by the microphone (16) only those sounds are compensated which are produced by the loudspeaker (18) and which reach the microphone (16) directly and which reach the microphone (16) indirectly via reflections from nearby objects. These sounds have a comparatively short impulse response time and enable a comparatively simple adaptive filter (38) to be used. The other sounds picked up by the microphone (16) reach the microphone (16) via reflections from the walls of the conference space (10) in which the conference system is situated. The other sounds have a comparatively long impulse response time.