Abstract: A synchronizing pulse is produced upon detection of a frame codeword or frame-structured binary signal consisting of a first word repeated a plurality of times and at least one second word. A demultiplexer divides the incoming signal into n words which are advanced in parallel through n shift registers of a first memory matrix, followed by the next n words, and so on. A decoder determines whether the first word is stored in each register, and increments a respective one of n counters when the word is found. An addressing logic transforms the output into a binary number which controls a multiplexer which, in turn controls arrangement of bits in a second memory matrix. A synchronizing pulse is produced when the second memory matrix contains predetermined bits of the first and second word.

Abstract: An element for conveying cells which are received on input lines (7a to d) and are destined for an output line 10. The interconnection element includes comparators (9a to d), each coupled to an input line and checking whether path identifications contained in the cells are assigned to the output line. In addition, a multiplexer arrangement (18) is present which by coupling the input lines to buffers (20a to d), uniformly distributes cells arriving during a time frame and destined for the output lines over the buffers in accordance with a predetermined sequence. The system further includes a multiplexer (21) for cyclic reading of the cells from the buffer.

Abstract: A telephone set having a voltage gain and control circuit element in series with the main current path of a line current control transistor, connected between first and second line end portions. The line current control transistor is connected between the first line end portion and the modulation terminal of the voltage gain and control circuit. A line current measuring resistor is connected between the reference terminal of the voltage gain and control circuit element, and the second line end portion. The rise of line current above a threshold is controlled by a second transistor connected between a threshold voltage source and the control electrode of the line current control transistor. The second transistor is also controlled by a compensating diode connected between the control electrode of the second transistor and the line current measuring resistor.

Abstract: A digital transmission system is disclosed having a transmitter (3,6,9) and a receiver (13,16,19) for transmitting a digital signal, such as a digital audio signal, having a given sampling rate F.sub.S. The digital signal is subband coded into M subbands with sampling rate reduction. To that purpose the transmitter includes a first unit (3) for splitting up the digital signal into M signals having a sampling rate F.sub.S /M. These signals are available at the outputs (4.1 to 4.M) of the first unit (3), and are applied to M analysis filters (6.1 to 6.M), each filter (6.m) having one input (5.m) and two outputs (7.ma and 7.mb). The 2M filter outputs are coupled to 2M inputs (8.1 to 8.2M) of a signal processing unit 9 which has M outputs (10.1 to 10M) for supplying the M subband signals (S.sub.1 to S.sub.M). Each filter (6.m) is adapted to apply two different filterings on the signal applied to its input and to supply the two different filtered versions of the input signal to its two outputs.

Abstract: Tripping of the poles of a multi-pole breaker requires less force from current sensing actuators, through use of a lost motion linkage including a trip link which unlatches the linkage holding one pole contact set closed before operating the inter-pole tripping elements. Preferably the breaker has a fast forcing arrangement for forcing a movable contact open under short-circuit conditions, faster than the normal contact opening spring can respond. The lost motion linkage is provided by a trip link which first releases a secondary latch to permit contact opening at normal speed, and then operates an inter-pole tripping element. Under short-circuit conditions the trip link engages the movable contact to force it open, between unlatching and engagement of the inter-pole tripping element.

Abstract: The invention relates to a cassette (3) for the trouble-free storage of an information carrier and for conveniently inserting this information carrier into a scanning device. The cassette comprises a sleeve-shaped housing (301) and a box-shaped holder (303) which can be slid into the housing. The housing has an open first side (309) and, opposite thereto, an at least partly open second side (311). The holder, which extends permanently into the housing through the first side, is movable between a slid-out position, in which the holder together with the housing forms a storage space for the information carrier, and a slid-in position for moving the information carrier out of the cassette via said second side. Latching means (327, 327B) have been provided for latching the information carrier in the slid-out position of the holder.

Abstract: A communications system suitable for use with hand portable radio telephones operating in a cellular mode, the typical cell size being between 500 m and 3 km radius. Each cell comprising at least one primary or base station (10) connected to the PSTN and one or more secondary portable stations (14) which are capable of roaming within the cell. Radio communication between the stations can be initiated by either station. Each primary and secondary station having radio transceiving means for time division duplex communication between the stations, a codec operating at 32 kbits/second or 11.4 kbits/second and means for transmitting digitised speech in accordance with a framed structure comprising 3 full rate or 6 half rate channels per carriers, the carrier being modulated at a carrier bit rate of substantially 270.8333 kbits/second. Provision is made for internal and external handover, if required.

Abstract: An optical recording element comprising a transparent supporting plate, a dye-containing recording layer and a first reflective layer which is applied to a recording layer. The element has a ROM (read only memory) region containing information which can be read optically and a RC (recording) region in which information can be recorded and read optically, the recording layer extending over the ROM and RC regions and a second reflective layer being present in the ROM region between the recording layer and the substrate.

Abstract: A paging receiver having a receiver section for receiving a digital data, and an evaluation section for developing, in response to the received digital data, digital output words including identification codes. A register stores an identification code, and a comparator compares digital output words from the evaluation section with the stored identification code. The receiver has a controlled divided power supply which is controlled according to whether the evaluation section outputs a digital word identical to the stored identification code.

Abstract: A planar optical head is described with a corrected input grating for scanning a surface, for example, a recording surface (2) in an optical record carrier (1). A radiation source (5) supplies a beam (6) which is coupled into a waveguide (9) by an input grating (7) and is formed to a focused scanning beam (11) by an output grating (10). Deficiencies of the radiation beam such as the non-round cross-section of the beam, astigmatism and wavelength variations caused by the radiation source can be corrected by means of an adapted grating structure of the input grating.

Abstract: A scanning device comprises a lens (2) having an optical axis (2a). The lens is movable in a focussing direction (F) to form at least one radiation spot on a surface to be scanned and in a tracking direction (T) oriented transversely of the focussing direction, in order to follow a recording track. The scanning device comprises a stationary section (16) with a magnetic circuit and one air gap (20), and a section (6) which includes the lens and is movable relative to the stationary section. The movable section comprises at least one focussing coil (12) and two tracking coils (14a, 14b) for driving the lens, the focussing coil having a coil axis (12a) extending parallel to the optical axis. The air gap is situated between the optical axis of the lens and the coil axis of the focussing coil. The movable section is secured to the stationary section by a compliant mechanical suspension (22a, 22b), and its mass center is situated in or at least near the air gap.

Abstract: A disc-record player includes a lazy Susan type changer mechanism (5) arranged within a housing, a drawer (7) movable through an opening in the housing, and having a supporting surface for moving information discs into and out of the housing for loading and unloading from the changer; a scanning device (3) for writing and/or reading information discs which have been transferred from a supporting surface on the changer to a turntable (17) of the scanning device; and mechanisms for rotating the lazy Susan and moving the scanning device relative to the lazy Susan for picking up a disc placed on the lazy Susan, and moving it into a scanning position. A positioning device has a drive unit for positioning the scanning device and lazy Susan relative to each other. The scanning device is moved to transfer a disc to the scanning position responsive to rotation of the lazy Susan.

Abstract: A receiver for FSK signals produces quadrature related first and second frequency down-converted difference signals (I and Q), which are amplitude limited to form respectively first and second square wave signals. The first and second square wave signals are sampled at changes in polarity of the second and first square wave signals, combined and fed to a memory, for example a hysteresis circuit, responsive to a change in polarity in the combined signal for producing a first substantially constant dc output until the next following change in polarity is detected whereupon a second substantially constant dc output is produced. By using a memory rather than a filter, reactive components are avoided making it less expensive to integrate. Also, a fixed level bit slicer can be used.

Abstract: The divider of the phase locked loop, which control transmitting or receiving frequency, is set to a selected one of a plurality of pre-set values. The selected channel number is entered into one of a bank of registers. The other registers are too short to store the entire binary number corresponding to the lowest division ratio. The lowest division ratio is obtained by concatenating the binary numbers stored in two or more of the registers, and the channel number is then added by binary addition.

Abstract: An optical system for determining the position and/or orientation of an object (10), for example, a freely suspended rotatable polygon mirror, comprises a convex mirror (24) on the rotation axis (11) of the polygon mirror and a plane mirror (25) perpendicular to the rotation axis. A convergent radiation beam is projected on the convex mirror (24). The reflected radiation is subsequently focused on a detection system (40, 45) via an astigmatic imaging system (75, 78, 51). A substantially parallel radiation beam is incident on the plane mirror (25), which beam, after reflection, is also focused to a radiation spot (34a) on the detection system (40, 46). The position and the shape of the radiation spots (34, 34a) are a measure of the position and the orientation of the polygon mirror (10). After processing, the output signals of the radiation detection system are applied to elements (91), for example electromagnets for stabilizing the polygon mirror (10).

Abstract: A device for inscribing and or reading a magneto-optical disc includes a turntable mounted for rotation about an axis of rotation, and an optical unit and a magnetic unit movably mounted opposite to and spaced from each other in a direction parallel to the axis of rotation. The optical unit and magnetic unit are mounted each to be movable in a plane transverse to the rotation axis. The magnetic unit includes a coil on a support which in turn is movably mounted on a displacement body which is radially moveable with respect to the axis. During operation a measurement and control system determines the radial position of the optical unit and the magnetic unit relative to each other in the radial direction, for controlling at least the radial position of the coil of the magnetic unit relative to an objective of the optical units.

Abstract: Data packets of mutually equal durations are transmitted from a plurality of substations to a main station via one or more transmission channels. The main station transmits on each transmission channel a synchronizing signal which indicates the beginning of a frame. A programmable memory stores maximum link establishment and maximum link disetablishment times which are characteristic of the transmission channel from the substations to the main station. The substations each comprise a programmable memory for storing the maximum establishment times and disestablishment times. On reception of the synchronizing signal on a transmission channel the substation subdivides the frame into a number of consecutive time slots of mutually equal durations at least equal to the sum of the duration of a data packet, and the stored maximum establishment and disestablishment times of that transmission channel.

Abstract: A disc-record player including a device for inscribing and/or reading information on a disc, a loading device for loading a disc into the player, and a disc-pressure device. The loading device includes a frame, a sub-frame and a drawer which is movable in inward and outward directions and has a supporting surface for a disc. The sub-frame carries a turntable, and is movable relative to the frame between rest and operating positions. Elements of a first type having inclined guide surfaces, and elements of a second type engaging the first type elements, guide movement of the sub-frame between the rest and operating positions. Elements of one of these types are arranged on the frame, and the elements of the other type are arranged on the sub-frame. Coupling elements couple the drawer to the sub-frame during a portion of the drawer movement in the inward and outward direction, for moving the sub-frame between its rest and operating positions.

Abstract: A receiver for time-varying distorted data signals, includes an equalizer and a channel estimator which generates a channel information signal with the aid of a training signal sent together with the data signal and with the aid of an image of the training signal stored in the receiver, and applies this signal to the equalizer. The receiver further includes an arrangement for channel tracking which generates correction values for the channel information signal with the aid of data detected by the equalizer. At very high relative velocities between the sender and the receiver (e.g. 200 km/h when using the mobile radio set in a motor vehicle, for example) a degradation of the bit error rate is avoided in that, at least part of or the complete received training signal is applied to the arrangement for channel tracking prior to the data signals to be equalized and detected after the channel information determined on the basis of the training signal has been transmitted.

Abstract: Rapid extinguishing of the arc in a circuit breaker is accelerated by a booster loop which extends parallel to an arc runner, but carries current in a direction opposite to the direction of current flow in the arc runner. The booster loop and arc runner are formed from a single piece of rigid conductor material, preferably stamped to form mounting lugs and bent over into a U-shaped configuration. In a preferred embodiment, the breaker internal connections are arranged such that current flows through a thermal overload sensor when the contacts are closed, but transfers to the booster loop and arc runner after arc current termination transfers from one of the contacts to the arc runner, thus reducing short circuit current duration through the thermal sensor.