Abstract: A combination of a monochrome cathode-ray tube with a deflection unit for applications which require high resolution. The deflection unit produces a magnetic field having a six-pole component which is positive on the screen side to minimize raster distortion and which, in the deflection center, has a strength and polarity sufficient to minimize spot distortion. Preferably the effective length 1 of the deflection field satisfies the conditon1.gtoreq.(0.2.tau..sup.2 +0.25)L,where L represents the distance between the deflection center and the display screen and .tau. is the tangent of the deflection angle of the electron beam for maximum deflection.

Abstract: A brushless d.c. motor comprises a commutation device by means of which the stator coils are connected to and disconnected from a direct-voltage source in a cyclic switching pattern for energizing said stator coils. In order to reduce torque variations as a result of transient effects in the energizing currents during commutation, the commutation device comprises means which cause the instants of disconnection and connection to be shifted by a fixed time interval relative to one another.

Abstract: The invention relates to an optical branching device which may be used as an optical isolator, circulator or switch. The device comprises two polarization-sensitive beam splitters. Each beam splitter comprises a prism and a rhombohedral plate between which a liquid crystal film is interposed. An optical device for rotating the plane of polarization of linearly polarized light is arranged between the two beam splitters. The polarization rotation device may comprise a Faraday rotator with a constant or a switchable direction of magnetization and a half-wave plate. Alternatively, the polarization rotation device may comprise a liquid crystal film interposed between two electrodes.

Abstract: A color printer for printing a color image of sequential lines of three different base colors, with a drum having a length of sheet-like information carrier wrapped around it and secured thereto. A transmission means having a gear ratio is connected between a motor shaft and the drum for rotating the drum. The gear ratio of the transmission means, the drum radius and the thickness of the information carrier are so selected that for a whole number of revolutions of the motor shaft the drum moves a location on the information carrier a distance equal to 2(.pi.R)+x from the position at which the location was when the motor started revolving wherein R is equal to the sum of the radius of the drum and the thickness of the information carrier and x is equal to the distance between two successive lines of different base colors in the printed color image.

Abstract: The combined modality device comprises an ultrasound transducer (10) which is suitable for transmission as well as reception and which is connected to a transmitter stage (20) as well as to a receiver stage (30). The transducer (10) has a bandwidth which at least equals approximately one octave. The transmitter stage (20) comprises a generator for generating activation signals for the transducer (10) with a frequency f.sub.o near the lower limit of said bandwidth, the spectrum of these activation signals excluding the frequency f.sub.1 =2f.sub.o. The receiver stage (30) comprises a B-scan channel and also a B/A processing channel (200) which itself includes a bandpass filter (210) which is centered around said frequency f.sub.1, an envelope detector (220, 230), a comparison circuit (240), a differentiation circuit (250) and a display device (260) whereby measured results in both modalities may be displayed.

Abstract: The support for a magnetic head rotating about an axis is relatively movable with respect to a circular cylindrical guide surface which guides the tape past the path of the rotating magnetic head. In the playing mode, the rotation axis is coaxial with the cylindrical guide surface axis. In a stand-by mode either the bearing support for the rotating head assembly, or the cylindrical guide surface, is moved radially a small distance away from the other such that the head remains in contact with the guide surface, but is clear of the path swept by the rotating magnetic head. When the two portions of the device are moved back into coaxial alignment for the playing mode, a position device locates them accurately so that the two axes coincide.

Abstract: The method and arrangement according to the invention utilize an adhesive tape (1) covered with a protective layer (2) provided with openings (4).This tape is glued on a film (5) carrying contact metallizations (8) and integrated circuit chips (6) electrically connected to the said metallizations. The tape is glued on the film in such a manner that its openings (4) correspond to the positions of the integrated circuit chips (6). Subsequently, a coating varnish is applied by pulverization to the film and then the protective layer is removed with the varnish covering it. Vignettes slightly larger than the said openings are then cut in the film in such a manner that an adhesive ring is left around the integrated circuit chips. Each vignette is finally arranged in a recess ad hoc (12) of a card (10).

Abstract: A television receiver which is suitable for displaying teletext pages comprises a control system including a microcomputer. The microcomputer is coupled to a volatile memory which comprises a plurality of page number registers. A page number can be temporarily stored in each of these registers. With the aid of a keyboard the user makes known which page numbers he wants to have stored in the different registers and the stored page numbers represent a first series of pages. One single read key (RCL) is provided for the display of such a page. Each time this key is depressed once, a different page belonging to the first series appears on the picture screen. The sequence in which the pages appear is the same as the sequence in which the user has keyed-in the relevant page numbers. This sequence can be interrupted by the occurrence of a preselected operating instruction in response to which a number of teletext pages not associated with said first series can be displayed on the picture screen.

Abstract: Method of automatic focussing of a video pickup device having an objective and producing a digital image. According to the invention, this method comprises analyzing the image, within a window, with the aid of at least one digital operator. The digital operator takes the derivatives, in a given direction, of the contours of the image. Thereafter, the absolute values of these derivatives are computed. Finally, a quality parameter defined by the sum, in the window, of the absolute values of the derivatives is calculated. The position of the objective of the pickup device is controlled so as to maximize the value of the quality parameter.

Abstract: A method is set forth of manufacturing a three-layer electrode system, more particularly for use in CCD image sensors. A group of first electrodes (4A,B,C) is formed on a gate oxide layer (3) by a first silicon layer (4). After etching away the exposed gate oxide, a first thermal oxidation is carried out. Subsequently, an anti-oxidation layer (6) of, for example, silicon nitride is provided, on which a second silicon layer (7) is provided, from which a group of second electrodes (7A,B) is formed. The second electrode overlap the first electrodes in part, whereupon they are subjected to a second thermal oxidation. The exposed part of the anti-oxidation layer (6) is removed by anisotropic plasma etching which maintains parts (6A) on the edge of the first electrodes and under projecting oxide edges. After a third thermal oxidation, a third silicon layer (9) is provided, from which a third group of electrodes (9A,B) is formed, which partially overlap first and second electrodes.

Abstract: An arrangement for indicating the refilling level of a collapsible ink container (1,2) comprising a measuring circuit having an alternating voltage source (U.about.) to form an electric control signal which depends on the capacitance (8) between the liquid ink and an electrically conductive coating (5) which is insulated with respect to the ink by the wall of the ink container wherein the electrically conductive coating (5) is provided on the outside of the lower part (1) of the ink container.

Abstract: A mask for X-ray lithography is formed of a multilayer diaphragm with a patterned absorber layer on the diaphragm. The diaphragm includes a layer of magnesium and at least one intermediate layer.

Abstract: A control device having a reciprocable drive element connected to a record command disc, a pick-up arm set down position selection member, and a guide element pivotally connected to the drive element for engaging a coupling element on a pick-up arm base to guide the pick-up arm pivoting toward the turntable. The guide element is pivotable with respect to the drive element between two stable positions. In the first stable position during forward movement of the drive element, the guide element passes an abutment on the pick-up arm base, and is then pivoted to the second stable position. During a turn movement of the drive element, the guide element first pivots the pick-up arm into abutment with a set-down position selection surface, and the guide element then pivots out of engagement with the abutment. Upon completion of the drive element return movement, the guide element is pivoted into the first stable position.

Abstract: An apparatus, such as an electron beam column (1), with high-speed deflection capability comprises a gun (2) which directs a beam (3) of charged particles by several magnetic lenses (9,11,13a,13b) towards a target (4). Magnetic deflection coils (12a,12b) produce a variable magnetic field for controllably deflecting the beam. The beam is surrounded by an electrically conductive surface (16a,16b,22) which in the vicinity of the deflection coils is constituted by a tube (22) comprising a single wire of, for example, nichrome preferably coated by an oxide film formed naturally and comprising a close-wound helix. This tube construction has a longitudinal resistance which significantly impedes the flow of undesirable eddy currents therein. On the other hand the tube can readily conduct along a helical path so that charge accumulation on the tube walls is avoided.

Abstract: An electroacoustic calling device comprising a piezoelectric transducer contained in a housing with an aperture therein through which sound is emitted. A closure member for controlling the size of the aperture, and hence the volume of emitted sound, is located in a recess in an arm pivotally mounted on the housing and is urged against the exterior surface of the housing by a projection at the bottom of the recess. The resulting essentially point contact between the closure member and the recess allows the surface of the closure member to align accurately with the surface of the housing, thereby minimizing leakage of sound between such surfaces.

Abstract: The invention relates to an electrochemical cell having a negative electrode of a stable hydride-forming material, in which a high power density at a low temperature and a rapid activation (as a function of the number of charge and discharge cycles) are obtained by adding to the electrochemically active material one or more metals selected from the group formed by Ni, Pd, Pt, Ir and Rh.The activating metal may be added to the bulk of the hydride-forming material or may be provided by substituting it for less noble metals at the surface of the powdered material.

Abstract: An apparatus for filling a cassette (34) with a length of magnetic tape (4) comprises a cassette holder (32) which is movable between at least two positions, a splicing table (68) which is provided with three rectangular mutually parallel vacuum pads, of which a first vacuum pad (71) is arranged on a stationary first block (69) of the splicing table and a second (72) and a third vacuum pad (73) are arranged on a second block (70) of the splicing table which block is pivotable about a pivotal axis (74), an extraction member (67) for withdrawing the leader tape (111) from the cassette and positioning it on the splicing table, a cutting member (77) for cutting the leader tape and severing a length of magnetic tape, a splicing member (25) for splicing the magnetic tape to the leader tape, a winding member (86) for winding the length of magnetic tape and leader tape into the cassette.

Abstract: An image enhancement circuit for eliminating noise from a series of image signals g.sub.i (t) representing images of a quasi-stationary object in a noisy environment. The image enhancement circuit is provided with an accumulator circuit and a weighting circuit. The weighting circuit receives a difference signal indicating the difference between the actual image signal g.sub.i (n) and the output signal h.sub.i (n) of the accumulator circuit. In the weighting circuit, the difference signal is multiplied by a weighting factor k(i) which is dependent on the ordinal number i of the actual image signal g.sub.i (n). For example, k(i)=1/i. The weighted difference signal is then added to the accumulator.

Abstract: A lens system is provided which is suitable for back-projecting an enlarged image of a TV cathode ray tube (CRT). To achieve a compact cabinet design 1 for such a projection television set, a short projection throw and a wide projection angle are required, together with a wide aperture (F/1) for a bright projected picture and with a definition which may need to be good enough to resolve 1249 line television pictures. The lens system comprises a CRT face plate FP which is either flat or has a relatively shallow curavature on one or both sides and four lens elements L1, L2, L3 and L4. L1 is a weak lens, L2 and L3 are each of positive power and L4 is a negative element close to the CRT. At least two of the element surfaces are aspheric. The powers of the elements are chosen so that-0.20K<K.sub.1 <+0.10K+0.60K<K.sub.2 <+0.85K+0.35K<K.sub.3 <+0.55Kand-1.20K<K.sub.4 <-0.90Kwhere K.sub.1 is the power of the first low power element remote from the object surface, K.sub.

Abstract: Method of recognizing pauses in a speech signal when a slowly varying noise signal is superposed on the speech signal. For the purpose of pause recognition so-called short-time mean values connected with a clock pulse are continuously determined from the samples of the disturbed speech signal, which short time mean values are a measure of the average power of approximately 100 ms long sections of the disturbed speech signals. The sequence of these short-time mean values is then smoothed by linear filtration or by means of a median filter. In parallel with the smoothing operation an estimate for the noise signal power averaged over a few seconds is taken from the sequence of short-time mean values. If the smoothed short-time mean value is once or several times less than a threshold which is proportional to the above-mentioned estimate, then it is decided that there is a speech pause.