Abstract: A differential amplifier contains first and second differential portions (20 and 22) that operate together to achieve rail-to-rail input amplification capability. A main current supply (6) provides a main supply conduit (I.sub.L) for the two differential portions. The circuit transconductance is controlled in a desired manner with a control amplifier (AN) suitably coupled to the differential portions and main current supply. A current-steering circuit typically formed with a pair of voltage clamps (30 and 32) enables a pair of level-shift current supplies (16 and 18) in the second differential portion to remain conductive as the input common-mode voltage traverses the entire supply voltage range. Consequently, the differential amplifier achieves a very fast response to changes in the input voltage difference irrespective of the value of the input commond-mode voltage.

Abstract: A D-type flip-flop arrangement includes first and second latches .Circuitry interposed between the latches blocks any metastable condition that may occur in the first latch from propagating into the second latch. Additionally, the arrangement minimizes the likelihood that the first latch will enter a metastable condition and, if it does, resolves the condition extremely rapidly.

Abstract: Apparatus is described for pre-forming a relief structure of optically detectable servo-track portions and sector addresses on the recording layer of a record-carrier body, the maximum transverse width of the servo-track portions and sector addresses being the same and exceeding approximately 1/2 the track period P.sub.r but being less than approximately 3/4 P.sub.r. This enables the servo-track portions to be tracked in an optimum manner by a radiation beam and the sector-addresses and the information recorded by the user produce a read-out signal of high amplitude.

Abstract: A Schottky-type diode is fabricated by a process that enables the diodes conductor-to-semiconductor barrier height .phi..sub.B to be controlled by adjusting the thickness of a metal silicide layer (22) which forms a rectifying junction (20) with an N-type semiconductor (24). In fabricating one version of the diode, a metallic layer (70) consisting of two or more metals such as platinum and nickel is deposited on an N-type silicon semiconductor (68) and heated to create a metal silicide layer (72) consisting of a lower layer (62) and an upper layer (74) of different average composition. A portion of the upper layer is then removed, allowing .phi..sub.B to be adjusted suitably.

Abstract: An optical scanning device which includes a radiation source, a mirror objective an a radiation-sensitive detection system, the mirror objective being a transparent body having a radiation window and a reflector symmetrical therewith on each of two opposed surfaces of such body. First diffraction elements are respectively arranged on the first and second radiation window and the second reflector, whereby radiation directed through the first window is focussed to a scanning spot on an information plane and radiation from such plane after a second passage through the mirror objective includes a number of diffracted beams directed on the radiation detection system. The diffracted beams enable detection of tracking errors and focussing errors of the scanning spot relative to tracks on the information plane.

Abstract: A semiconductor PROM contains a group of PROM cells (12) each consisting of a pair of opposing diodes oriented vertically with their common intermediate region (22) fully adjoining a recessed oxide insulating region (16). A composite buried layer consisting of buried regions (32) which adjoin the insulating region below the lower cell regions (20) and an opposite-conductivity buried web (44) which laterally surrounds each buried region is employed to improve programming efficiency. Connective regions (46) extend from the buried web to the upper semiconductor surface to contact electrical leads (54) typically arranged in a parallel pattern. The maximum dopant concentration in the intermediate cell regions occurs vertically within 20% of their mid-points.

Abstract: A method of longitudinally severing a longitudinally symmetrical annular core of ferromagnetic material into two parts. By means of a laser, two lines of recesses are inscribed in the surface of the annular core substantially in the longitudinal direction. The recesses are shaped so that the resulting weakening of the annular core along the lines of recesses causes it to spontaneously fracture into two parts along such lines.

Abstract: A record carrier is described having an optically readable information structure comprising information areas arranged in information tracks and spaced from each other by intermediate areas. The information areas have a first, comparatively large, phase depth and the intermediate areas have a second, comparatively small, phase depth thereby providing an optimum information signal and an optimal tracking signal during reading.

Abstract: A method of, and a device for, reducing the magnetic stray field generated in the vicinity of the faceplate of a cathode ray tube by the deflection current in the deflection coils of the tube. A current loop (4) is arranged at a distance from the deflection coils and is supplied with current having a time function substantially coinciding with the time function of the deflection current. The stray field is thereby neutralized to a large extent in a region extending beyond the position of the current conductor (4) in a direction away from the faceplate.

Abstract: A telecommunication exchange which provides secure access by only authorized terminals to a computer connected to the exchange. The control processor in the central control unit of the exchange is programmed to provide a "call-back" procedure in respone to a request from a terminal for access to the computer. The calling terminal enters by tone or pulse dialing, the address (such as a telephone number) of the computer together with an identification code. The control processor compares such identification code with a list stored therein of authorized identification codes and authorized terminals addresses corresponding thereto. If the identification code is authorized, the control processor causes a confirm signal to be transmitted from the exchange to the requesting terminal signifying to the user of such terminal to release its line, after which a ringing signal is transmitted to the authorized terminal address corresponding to the authorized code.

Abstract: Optical record carrier scanning apparatus including a source of radiation which is tunable to produce different wavelengths of a radiation beam and an optical assembly for forming the radiation beam into a spot for scanning information tracks on the record carrier. The optical assembly includes a diffraction grating which diffracts the beam so that only a selected diffraction order sub-beam thereof is formed into the scanning spot, the diffraction angle of such sub-beam and consequently the position of the scanning spot relative to the track being scanned being variable by variation of the wavelength of the radiation beam. A periodic transverse variation of spot position can thus be produced entirely optoelectronically, for producing a tracking error signal to control the scanning spot to remain centered on the information track.

Abstract: A differential amplifier coupled between sources of a high supply voltage (V.sub.HH) and a low supply voltage (V.sub.LL) contains a pair of differential portions (30 and 32) that are used to amplify a differential input signal (V.sub.11 and V.sub.12). One of the differential portions is turned on when the common-mode voltage of the input signal is in a portion of the supply range extending up to the high supply voltage. The other is turned on when the input common-mode voltage is in a portion of the supply range extending down to the low supply voltage. A level-shift circuit (38, 40, 42, 44, and 46) selectively raises or loweres the voltages at input points (P1, P2, P3, and P4) to the differential portions. The level shifts extend the conductive ranges of the differential portions. This enables the amplifier to achieve rail-to-rail input capability down to 1 volt or slightly less for the power supply voltage.

Abstract: Either one of the fields of an interlaced television signal is designated as top field as indicated by a first selector signal. The presence of a second selector signal indicates bottom field. A regenerated vertical synchronization signal is furnished for the first horizontal synchronization signal following vertical synchronization in top field. This regenerated vertical synchronization signal resets a counter which counts horizontal synchronization signals repetitively to a count of five. A second regenerated vertical synchronization signal is furnished when the count of five is reached following the vertical synchronization signal of bottom field. The counter is reset by each first regenerated vertical synchronization signal. When a synchronization signal which would normally be designated top field occurs within a predetermined window around horizontal synchronization, the subsequent field is designated top field, i.e. a field switch takes place.

Abstract: A method and apparatus are described for recording a binary information signal (FIG. 2a) on a record carrier (1) having an information layer (2) whose optical properties are modified upon heating. An information pattern corresponding to this information signal (FIG. 2a) is obtained in that the record carrier 1 is moved relative to an optical system (3) for focussing a radiation beam (4) on the information layer (2), a subsequent recording mark (5) being written on the information layer (2) in selected time intervals (.tau.) by locally heating the information layer by means of the radiation beam (4). The amount of radiation energy (E) applied in a selected time interval depends on the position of the selected time interval (.tau.) in the sequence of consecutive selected time intervals (.tau.). This provides compensation for the influence of the radiation energy (E) applied in the preceding time interval (.tau.) on the temperature at the location of the recording mark (5) to be written in the time interval (.

Abstract: Finite audio and video signals are subjected to some digitalizing encoding format and converted into blocks of audio and video words, respectively. For transmission of these blocks via a compact disc, the words are arranged in packets. Each packet has a packet header and a data field. Such a data field comprises either only audio words or only video words. The packet heater indicates whether the associated data field comprises audio or video words. In order to transmit only changes in the picture in the case of, inter alia, quasi-stationary pictures, each block of video words is divided into a number of sub-blocks and an operational code is added to the beginning of each sub-block. This defines, inter alia, picture elements and the sub-block itself gives video words for these pictures elements.

Abstract: Optical scanning apparatus which includes a diode laser producing a radiation beam which is focussed by a lens system on a reflecting information plane to be scanned thereby. The reflected radiation is diffracted by a composite diffraction grating which includes a pair of sub-gratings, forming respective radiation spots on respective pairs of radiation detectors. The detectors in each pair are separated by a separating strip, the separating strips being substantially parallel to or co-linear with the bonding line between the sub-gratings. Such arrangement achieves correction for wavelength variations of the radiation beam, as well as fairly wide tolerances in the relative positioning of the various optical elements of the apparatus.

Abstract: A system for recording and/or reading an information signal (V.sub.i) on an elongated track (4) of an optically readable record carrier (1). A position-identifying signal (V.sub.p) which is synchronous with a clock signal is recorded on the track 4 by modulating the transverse excursion of the track, the signal V.sub.p indicating the instantaneous position along the track at which the information signal V.sub.i is located. The frequency band of the position-identifying signal V.sub.p is situated substantially outside the frequency band of the information signal V.sub.i. In manufacturing such a record carrier, the deflection of a recording beam of radiation in a direction substantially transverse to the track is modulated by the position-information signal V.sub.p.

Abstract: A mobile radio facility for installation in a motor vehicle which already includes a junction cable extending from a location in the trunk to a location in the passenger compartment, terminating at each end in a plug connector. The facility includes a radio unit which can be installed in the trunk and plug connected to the vehicular cable, and one or more peripheral units in the passenger compartment such as a micro-telephone, control panel and/or portable telephone. Each peripheral unit has at least a pair of identical plug-in terminals providing identical connections thereto. The facility also includes a plurality of additional junction cables, one of which is plug-connected at one end to the vehicular cable and at the other end to a plug-in terminal of one of the peripheral units. Each of the remaining cables is plug-connected at each end to a plug-in terminal of different peripheral units so as to establish a sequential order of interconnection of all such units to the vehicular cable.

Abstract: Page-mode-organized ROMs and associated circuitry are connected only to data and control buses in an information processing system. Addressing and reading of the ROMs are controlled by a processor without connecting the ROMs to an address bus. Selection of a particular ROM and of a particular page in the selected ROM is accomplished by applying a first control signal to the control bus and a first data word to the data bus. This first data word thus serves as the address of the selected page in the selected ROM. Then a particular byte of the selected page is selected by applying a second control signal to the control bus and a second data word to the data bus. This second data word serves as the address of the selected byte. Subsequently, in response to a third control signal, the selected byte is read out of the selected ROM and applied to the data bus.

Abstract: Upon receipt of an interlaced television signal, the field generator generates a first selector signal arbitrarily selecting one of the fields as top field and a second field selector signal selecting the other as bottom field. The received television signal is entered into memory under control of the field selector signals. When readout from the memory occurs on the same line that is currently being recorded, the same field selector signal is maintained for another field, effectively switching the top and bottom assignments.