Abstract: In a noise suppression circuit for a video signal the number of elements required can be reduced when a separation circuit (3) for a high-frequency and a low-frequency component is used and the noise suppression is effected in the low-frequency component by means of a comb filter (19) which, in order to realize a still further savings in components, may comprise a delay circuit having a delay (103, 105, 107) which is switchable between a field period plus half a line period and a field period minus half a line period. The noise suppression circuit is therefore particularly suitable for use in television receivers.

Abstract: A method of manufacturing integrated circuits by means of a multilayer mask.Etching of the layers of the mask comprises a lateral etching of the bottom layer so that at the edge of the auxiliary layer edges appear which are removed partly prior to forming an insulating layer and partly after the formation thereof, after which a remainder of a mask portion is also removed as a result of which removal apertures for the formation of zones are determined.

Abstract: In manufacturing a semiconductor device, a semiconductor body (2) is first provided with a first insulating layer (3,4) having a homogeneous dielectric thickness. A first conductor pattern (5) of polycrystalline silicon is then provided on the first insulating layer. A second insulating layer (6) is formed by oxidation of the first conductor pattern in such manner that the dielectric thickness of the first insulating layer remains approximately constant. Insulating paths (8) are then formed in spaces below edges (9) of the second insulating layer by successive deposition and etching steps. During the deposition step, a temporary layer is deposited to a thickness exceeding half the height of the spaces. During the etching step, the temporary layer is removed from the second insulating layer. Finally, a second conductor pattern (7) is provided on and beside the second insulating layer.

Abstract: This closed loop multiplex communication system uses a timing unit to establish a general multiplex format consisting of 1024 frames in a multiframe. Each subscriber station transmits one message bit per frame (i.e. 1024 message bits per multiframe), but transmits only 32 signalling bits per multiframe (i.e. the eight-bit non-message blocks in four corresponding frames).

Abstract: A substantially flat and disc-like shaped sound transducer for sensing sound waves in a fluid transmission medium and having directional and omnidirectional response characteristics to the sound waves. The sound transducer having a circular vibratile plate divided into quadrantal portions and having a surface adapted to be coupled to the transmission medium for providing sound wave motion in the portions dependent upon, and in response to, sound wave travel in the transmission medium and having a plurality of electroacoustic transducer elements coupled to the quadrantal portions of the vibratile plate for providing electrical output signals in response to the wave motions in diametrically opposed quadrantal portions. The sound transducer responding to incident sound waves having wavefront travel directions, in the transmission medium, substantially parallel to the coupled surface.

Abstract: There is provided a single-tank X-ray unit having a closed cooling circuit arranged in a housing for circulating a cooling agent to discharge the heat generated in the anode. The cooling circuit includes a feed duct and a return duct respectively wound helically around the high-voltage generator. A fan is so positioned in the housing as to pass cooling air over the cooling circuit, the housing having openings respectively for the intake of the cooling air and the discharge of the same.

Abstract: In a self-oscillating mixing stage for FM radio receivers, comprising a transistor producing the oscillator signal and to whose emitter circuit the high-frequency signal is coupled and from whose collector circuit the intermediate-frequency signal is coupled out, the transistor being operated in the grounded-collector circuit mode to produce the oscillator signal and in the grounded-base circuit mode to process the high-frequency and intermediate-frequency signals.

Abstract: A shaving apparatus comprising a shear plate and an associated reciprocatory cutting member is provided with cutting elements each having a frusto-conical cross section and being in contact along its base with the shear plate, the opposite sloping sides of a cutting element each forming a guide face. A plurality of individual lead cutters is movable relative to an associated guide face, with such plurality of lead cutters being arranged in side-by-side relationship and engaging the guide face. The lead cutters respectively engaging opposite guide faces are disposed in pairs. Each lead cutter moreover is elastically loaded in the direction of the shear plate.

Abstract: A shaving apparatus has a circular shear plate provided with hair-entry apertures and a cutting unit associated with and rotatable relative to the shear plate. The cutting unit comprises a cutting member having a circular central body provided with circumferentially arranged cutters and lead cutters respectively associated with and movable relative to the cutters. Each lead cutter is secured to the central body of the cutting member by a resilient connecting arm, the inner end portion of which extends substantially radially with respect to the cutting unit axis and undergoes torsion-loading by reason of the movement of the lead cutter away from the shear plate, the lead cutter being connected eccentrically to such inner end portion. The torsion-loading is elastically opposed in each instance.

Abstract: A hair roller holder comprises an elongated hollow handle defining a chamber for successively accommodating a plurality of hair rollers. Associated with the chamber is an arrangement for electrically heating the rollers therein. The chamber has an inlet opening at one end for insertion of the rollers in unheated condition and an outlet opening at the other end for discharge of the rollers in heated condition. Adjacent such outlet opening and externally of the chamber is a support for receiving a heated roller in a manner so that hair can be wrapped onto the roller and the roller can be manipulated by the handle. Provision is made in the chamber for guiding movement of the successive rollers therethrough onto the support. The movement guiding means may comprise guide pins in the chamber upon which the rollers are slidable and which are provided with electric heating elements for heating the rollers.

Abstract: A shaving apparatus has a circular shear plate provided with hair-entrance apertures and a cutting unit associated with and rotatable relative to the shear plate. The cutting unit comprises a cutting member having a circular central body and a hair-pulling member having a circular central portion. Cutters extend from the central body circumference toward the shear plate, with each cutter having a guide wall. A lead cutter is associated with and movable along the guide wall of each cutter, the lead cutter being connected to the central portion circumference by a V-shaped elastically deformable arm. One link of the connecting arm is secured to the central portion and extends tangentially therefrom; and the other limb is connected to the lead cutter. Each connecting arm is elastically deformed so as to urge its lead cutter against the guide wall of the associated cutter.

Abstract: A dry-shaving apparatus comprising a circular shear plate; a circular cutting member associated with and rotatable relative to the shear plate; mechanism to effect rotation of the cutting member; and a rotatable spindle tiltably coupled at one end to said cutting member and tiltably coupled at the other end to said rotating mechanism, each such tiltable coupling including a three-point contact equi-spaced about the axis of rotation of the rotatable spindle between said rotatable spindle and the cutting member on the one hand and between said rotatable spindle and the rotating mechanism on the other hand.

Abstract: A method for coating, etching, or coloring a portion of the surface of small articles wherein a plurality of the small articles are supported mainly by the surface tension of the interface between air and a liquid containing a desirable coating, etching, or coloring solution. The small articles are then removed from the solution with the result being that only the portion of the article in contact with the solution becomes treated. The size of the portion of the surface of the small article to be treated can be controlled by adding surfactants to the solution to vary the surface tension.

Abstract: A surface of an insulating substrate, if not wettable, is made wettable, then moistened with water and brought in intimate contact with a water soluble crystal layer, whereby a strong bond between the crystal and the substrate will result.

Abstract: An X-ray fluoroscopy device comprises a television camera for locating the irradiation field. This camera forms an optical image of the object to be irradiated. This image can be displayed on a television monitor, together with an image of the irradiation field, so that the position of the irradiation field within the object can be directly observed.

Abstract: A switchable synchronizing-signal generator suitable for several television standards, information being supplied from a series arrangement of a clock pulse generator and frequency dividers to a synchronizing signal generator. The generator has a position for the N-standard which is a modified position for the M-standard, because the supply of pulses of double the line frequency to a divide-by-525 dividers is blocked during 50 line periods of each field period.

Abstract: Apparatus for examining objects includes a group of X-ray sources, which are activated group-wise by a generator. A group of sub-images are separately projected onto a photographic film. During a subsequent step, the film is re-imaged with the aid of an optical lens matrix the lenses in the matrix are arranged in a manner similar to the X-ray sources.

Abstract: A detector suitable for use in a recording amplifier of a cassette recorder for limiting the signal which is applied to the write head at a specific average amplitude. The detector comprises a pre-amplifier T1 to T4 having an input (15) and an output (17); a comparator (T6) having a first input (base) coupled to the output of the pre-amplifier, and a second input (emitter) for detecting whether a detection voltage at the second input is exceeded by the voltage on the first input of the comparator circuit; a reference voltage source (V.sub.ref); first means (4) for maintaining the d.c. level at the output of the pre-amplifier (T1 to T4) at the level of the reference voltage source (V.sub.ref); and second means (T10, T11) for raising the detection level of the comparator circuit by the reference voltage.

Abstract: A method of and a device for switching-off a supervision system, e.g. a system for supervising the speed of a train. It must be possible to switch off the supervision system, but only when a predetermined pattern of operations are followed. This is achieved by using a time control activation current loop to briefly operate a contact device by means of first and second operating members in combination with a time independent activation current loop that holds the contact device closed provided the predetermined pattern of operations is followed.

Abstract: A supply circuit for a telephone subscriber's line circuit that includes a voltage source and a supply impedance connected in series with the line to the voltage source for limiting the line current upon short circuit of the line. The supply circuit includes an AC voltage generator, an AC/DC converter, and a circuit for coupling the AC voltage generator to the line via the supply impedance and the AC converter.