Abstract: A method and apparatus for scanning a plurality of concentric or spiral tracks on the surface of a rotating disc-shaped record carrier with a beam of radiation which may be modulated with information to be recorded on such surface. The beam is produced by an optical head and is directed at a target point on the record carrier by a positioning device and a deflection device, the positioning device radially displacing the optical head and the deflection device radially deflecting the radiation beam produced by the optical head. The composite resultant motion of the target point on the carrier is in a radial direction and includes a non-reversing component produced by the positioning device and a reciprocating component produced by the deflection device.

Abstract: A high definition television signal having 525 lines per frame, a sequential scan, and 59.94 frames per second is encoded into a time multiplex signal for transmission. The encoder drops alternate line, but creates line difference signals which allow reconstruction of the dropped lines at the receiver. The line difference signals are time compressed, while the luminance signals of the alternate, transmitted lines are time expanded. The encoder can accept programs from any one of a plurality of program originators, as long as the frame and line rates are multiples of one another. The time multiplex signal carries luminance and chrominance components in each line, but update signals such as high frequency luminance, high frequency chrominance and the line difference signals in a predetermined pattern in sequential frames.

Abstract: The invention relates to a circuit arrangement for a low-frequency amplifier having volume control, particularly in car radios, for noise reduction when the volume control means (10) is set at minimum. The noise reduction is achieved in that the signal path following the last amplifier stage (23) incorporates an electrically controlled switch (26) by means of which the signal path can be opened when the volume control means (10) is set at minimum.

Abstract: Television receiver including a switched-mode power supply which is regulated and capable of functioning both in self-oscillating mode and under the control of a line frequency synchronization. During normal operation there is synchronization, and the line time base supplies most of the supply voltages to the circuits of the receiver. To change to the stand-by state the drive of the line transistor is stopped, which stops most of the circuits depending thereon. The switched-mode power supply continues to function but then in the self-oscillating mode, and supplies the stand-by device via a secondary winding of its storage inductor.

Abstract: In magnetic resonance imaging apparatus in which bird-cage coils are used in combination with other coils, a capacitance is bridged by means of an inductive element. Substantial detuning and hence adequate uncoupling of the bird-cage coil from the other (receiving) coil is achieved. Use can be made of the already present coaxial transmission line via which the RF energy is applied to the bird-cage coil. Connecting the core and the jacket of the coaxial transmission line there is arranged a diode switch so that the bird-cage coil circuit can be electronically detuned, thus enabling fast switching on and off of the bird-cage coil.

Abstract: The disclosed circuit determines whether a video signal is from a video tape player or a broadcast signal source by measuring jitter of the vertical synchronization pulses. In one embodiment, every other time interval between the vertical synchronization pulses is measured and saved as a count, and each count is compared to the preceding count to determine whether sufficient jitter is present to indicate that the video signal is from a local tape player. In another embodiment all intervals between the vertical synchronization pulses are measured and a predetermined number thereof are saved as counts. The even and odd counts are then analyzed separately, and the extreme count (the most deviant count) of each group is eliminated.

Abstract: An optical scanning unit with an objective for the focussing a beam of radiation along an optical axis into a scanning spot on the surface of an information carrier. The scanning unit also has an electromagnetic drive for correcting the position of the objective with respect to the information carrier. The drive has an objective mount supported in an annular, moving magnetic member which is axially magnetized and is arranged coaxially about the optical axis. The drive is further provided with fixed coils which interact with the magnetic member via an air gap. The fixed coils are arranged along at least three radial planes which are normal to the optical axis. Two planes lie in the area of the axial ends of the centrally positioned magnetic member and the third central plane which extends between the two outer radial planes.

Abstract: A differential amplifier circuit for regenerating complementary analog signals of low amplitude includes a differential pair of field effect transistors whose common sources are connected to a first supply voltage V.sub.SS via a load, a pair of loads which are connected to the drain of each transistor of the differential pair and to a second supply voltage, respectively, and a level regenerating circuit having a pair of diodes for deriving the signals from the drain of each transistor of the differential pair. The signals transported by the diodes are applied to the lower transistor of a pair of push-pull stages whose upper transistor directly receives the signal derived from the drain of the other transistor of the differential pair, while the source of the lower transistors of the push-pull stages is connected to ground and the drain of the upper transistor of these stages is connected to the second supply voltage V.sub.

Abstract: The invention relates to a logic MOS gate of the domino type, having a precharging transistor, a validation transistor and logic transistors. To prevent unwanted discharging of a precharged high level, which may be induced by at least one input data being stabilized too slowly, that is to say not before a clock signal has risen to the high level, a p-MOS sub-network is arranged in parallel with the source-drain path of the precharging transistor and receives at least the input data which was too slowly stabilized in such a manner as to establish a conductor path which reestablishes the precharged high level.

Abstract: An electronic information display system which is organized as a reference information display system. The system comprises a reference source in the form of a compact disc CD ROM, which constitutes a mass read-only memory for the system. The disc contains text, graphics and/or sound data portions for a plurality of items of information. The disc also contains a list of these items together with addresses for their respective data portions. The system is processor-controlled such that the list and addresses are read from the disc into a programme memory. Using scrolling and/or selection techniques, the list can then be displayed a part at a time until a required item is found. Selection of this item will result in its data portions being transferred from the CD ROM to the programme memory where they can be accessed for use (i.e. visual or audible).

Abstract: A select buffer circuit includes a first inverter circuit, a second inverter circuit connected to the first, and a circuit for charging and discharging the base of an inverter transistor in the second inverter circuit from a node in the first inverter circuit. The charging and discharging circuit includes a Schottky diode connected to the inverter transistor, a Schottky transistor connected in series with the diode, and a resistor for coupling the base of the Schottky transistor to the node in the first inverter circuit. A bipolar multiplexer including the select buffer circuit offers the advantage of an improved output waveform.

Abstract: The invention relates to a blown lamp bulb having a parabolically curved wall portion, a neck-shaped wall portion near the apex of the parabolically curved wall portion. The bulb has a an axis of symmetry and a largest diameter. A curved wall portion is opposite the parabolic wall portion and has a focus which is located near the neck-shaped wall portion. The curved wall portion has a spherically curved portion having a center of curvature on the largest diameter or above it and a flattened portion proximate the axis of symmetry. The lamp bulb renders it possible to manufacture, by the choice of the finish of the lamp bulb, a large number of lamp types.

Abstract: In a magnetic resonance imaging apparatus an RF rotating field is generated by applying RF energy to two mutually perpendicular coil systems, a 1/4.lambda. lead being provided between the connection points of the systems. In that case the drive points and the detection signal output points are not the same, so that in the case of a change-over from transmission to reception, the connection between the transmitter and the receiver must be switched over. In the magnetic resonance imaging apparatus in accordance with the invention, a phase difference of 180.degree. is created between two junctions by means of 1/4.lambda. leads so that an intermediate junction will actually not carry a voltage. This point (for transmission and reception, two different points) is connected to ground by means of a PIN diode. A simplification enables connection of the transmitter as well as the receiver to the transmitter/receiver coil system via a single coaxial cable.

Abstract: A high voltage semiconductor device includes a two-dimensional array of polygonal regions in a higher resistivity body portion of the opposite conductivity type. The p-n junction between these regions and the body portion may be, for example, a drain junction of a D-MOS transistor or a collector junction of a bipolar transistor and is reverse-biased in at least a high voltage mode of operation. In order to relieve the high electric field at the corners of the polygonal regions, a plurality of further regions is distributed in each area of the body portion between facing corners of three or more of the polygonal regions. These further regions of the same conductivity type as the polygonal regions are located on at least one line from each of these corners in a symmetrical arrangement of the further regions within each area.

Abstract: In integrated circuits the delay of the signal transitions has to lie within specified limits. This delay is partly determined by variations in the manufacturing process (process scatter). To compensate for the effect of this scatter a load capacitance is connected via a switching element to a node which is to be influenced in the integrated circuit. The switching element receives a reference voltage which is dependent on the manufacturing process and is generated by reference source, so that the node capacitance 26 is connected to the node for a longer or shorter time, depending on the process scatter.

Abstract: A method and apparatus are described for recording a binary information signal on a record carrier having an information layer whose optical properties are modified upon heating. An information pattern corresponding to the information signal is obtained by moving the record carrier relative to an optical system which focuses a radiation beam onto the information layer. A recording mark is written on the information layer is selected time intervals by locally heating the information layer with the focussed radiation beam. The amount of radiation energy applied during a selected time interval depends on the position of the selected time interval in the sequence of consecutive selected time intervals. This provides compensation for the increase in the temperature at the location where the mark is to be recorded due to heating of the layer during recording of a mark in the preceding time interval.

Abstract: The remote control unit has a selection mechanism for selecting any one of a number of categories of equipment to be controlled. The commands available for keyboard input in any given category are automatically displayed to the user upon selection of the category. Switches are provided for user selection of the model number of any one of a number of manufacturers of the equipment within the category to be controlled. Operation of the switches allows program controlled read-outs of formats stored in memory. An infra-red LED is then energized in accordance with the format to transmit the signal to the unit to be controlled.

Abstract: An electro-optical apparatus comprising an objective (7) scans an optical disc (3) having a transparent protective layer (5) by means of a radiation beam (10) which, through the transparent layer, is focussed on a reflecting recording surface (4). The objective moves along the optical axis (19) for focussing the radiation beam on the recording layer and moreover performs limited pivotal movements. The position of the optical axis of the objective is corrected for obliquity of the surface of the optical disc, correction means (22A, B) being provided to tilt the objective through a correction angle, so that the angle between the optical axis and the normal to the disc surface is reduced.

Abstract: In a magnetic resonance imaging apparatus having a comparatively large measurement region, such as used for medical diagnosis, high-order contributions to the magnetic field are compensated for by the addition of pairs of rings made of a soft-magnetic material, so that the homogeneity of the magnetic field is locally increased to a high degree. This makes possible to use a substantially shorter coil while the field homogeneity in the measurement zone is still improved.

Abstract: The invention relates to a CCD having a so-called diode cut-off input, in which the input diode is applied to a reference voltage and the input signal is supplied to the input gate located in front of the first clock electrode. More particularly, if the electrodes are composed of a transfer part and a storage part with an incorporated potential difference, it is possible that, when charge is transported from the input gate to the first clock electrode, a large amount of charge is left behind. In order to avoid this and/or to be able to enlarge the dynamic range of the input signal, a MOST switch controlled by the same clock voltage as the first clock electrode is arranged between the input gate and a reference voltage, for example ground. This switch becomes conducting when the charge is transferred, as a result of which the potential level below the input gate can be adjusted above the surface potential below the transfer part of the first clock electrode.