Abstract: Telephone apparatus including a loudspeaker and a microphone, a speech transmission network that on the one side is coupled to the loudspeaker and the microphone and on the other side can be coupled to the telephone lines, and a modem having an input and an output, wherein the modem for AC-currents is directly coupled to the speech transmission network and for DC-currents is isolated from the speech transmission network. By these features it is possible to provide a telephone apparatus having the possibility of data-communication with as little as possible additional components, so that the telephone apparatus can be very low priced.

Abstract: For subband coding of a signal such as a digital stereo signal, the digital signal is split into subbands each comprising at least first and second subband signal components. The subband signal components in a subband m are constituted by blocks of q samples each, represented by a certain number of bits (n.sub.mr, n.sub.m1). The number of bits is the result of allocation based on a determination of bit needs for blocks in each subband. A determination is made whether or not initially bits are to be allocated to a signal block of one component in a subband prior to the bit allocation, and irrespective of the bit need for that signal block. If it is determined that an initial bit allocation is required for a particular signal block in a subband, an initial bit allocation is also applied to at least a second corresponding signal block in that subband.

Abstract: A method of and a circuit arrangement for decoding RS-coded data signals is which data signals may be coded both in accordance with a code generator polynomialG(x)=(x+.alpha..sup.0) (x+.alpha..sup.1) . . . (x+.alpha..sup.15)and in accordance with a code generator polynomialG(x)=(x+.alpha..sup.120)(x+.alpha..sup.121) . . . (x+.alpha..sup.135).Dependent on the relevant code generator polynomial, switching takes place between two different constant multipliers in syndrome generators, and syndromes and erasure locations which have been determined are subjected to a Euclid's algorithm for deriving error location polynomials and error value polynomials. Error locations and error values for a code generator polynomial starting with .alpha..sup.0 are computed by means of a Chien zero search. Parallel thereto, a correction factor for a code generator polynomial starting with .alpha..sup.120 is determined. The computed error values of the code generator polynomial starting with .alpha..sup.

Abstract: The arrangement is formed by the presence in each node of the network of a cellular automaton comprising cells (0 to 8) interconnected by lines, so that the entirety of the cells and of the lines represents the nodes and the links respectively of the network while each cell comprises calculating means for calculating the cost of a path, works asynchronously, and communicates with each of its nearest neighbouring cells and only with them. When the arrangement is simulated in a sequential machine, this machine is programmed to choose the order in which the cells are activated on the basis of the minimum number of links to be passed through to connect two nodes, which nodes are determined by having the cellular automaton turn when the states of the links are mutually equal.

Abstract: An arrangement comprising a controllable clock signal source (1), a decision circuit (8) for determining the polarity of a received biphase signal at two successive sampling instants in a single symbol interval, and a phase detector (35) with a first comparator (16) to compare the polarity samples at the two sampling instants with each other. The phase detector generates a control signal for adjusting the frequency and phase of the adjustable clock signal source (1) in response to the output signal of the first comparator. A second comparator (28) compares polarity samples at the same relative sampling instant in two successive sampling instants with each other. The second comparator (28) inhibits phase detector (35) in response to the output signal of this second detector. In the case of false synchronization, the output of phase detector (35) will continue to present the same signal value, so that automatically an adjustment is made of the instant of correct synchronization.

Abstract: The terminating impedance can be set electrically to eliminate selection and installation of discrete components in order to meet network manager specifications. A control device such as an EEPROM is easily adjusted (programmed) to control circuits presenting a predetermined specified impedance to the communications line. The impedance is preferably formed by a switched capacitor filter in which ratios of capacitance rather than absolute values are easily obtained during manufacture of an IC. The DC termination value may be set separately from the AC impedance.

Abstract: A doubler for a pulsed multimode laser diode. A controllable feedback loop controls the laser output such that one of the output wavelengths, or the average of two of them, fall within the acceptance bandwidth of a non-linear optical medium. Alternatively, radiation emitted from the pulsed laser is reflected over a path length such that reflected energy reenters the laser during the build-up of a following pulse.

Abstract: The availability and location of a multiplicity of multiplexed digital information streams, transmitted over one of a multiplicity of channels, are identified by transmitting a Global Channel Map which includes a version number, one Band Map Table, one Channel Map Table, and at least as many Service Map tables as there are combinations of identical service types transmitted over different channels. The Band Map Table preferably contains an entry for each frequency band used by the system, and a Band Map Table version number. A Global Channel Map Updates file is transmitted in each band. Where a plurality of channels contain similar-types of services, one Service Map Table contains relative service identification numbers for those service types. The entries for relevant channels in the Channel Map Table contain base service identification data which are combined with the relative service identification number to locate a particular service transmitted over that channel.

Abstract: A circuit breaker having an arc chute adjacent the arc path between a fixed and a movable contact. To aid in extinguishing the arc under short circuit conditions, an arc suppressor element is fixed on a movable surface adjacent the movable contact; and preferably on the arm itself facing the fixed contact and arc chute. The arc suppressor is made from a thermoplastic material such as nylon 6/6 which has high temperature resistance and high dissipation factor, and absorbs a relatively large amount of water. During interruption of a high current arc, heat shock liberates gases and water vapor from the suppressor material to neutralize arc ions and blow the arc toward the chute.

Abstract: An optical reader for record carriers of a two types adapted for scanning with radiation beams. The information structures of the respective types are arranged in tracks. The structure of the second type has a phase structure in which effect areas alternate with intermediate areas, and is adapted for scanning with radiation of a wavelength longer than that for the first type. This reader scans both types with radiation of the first wavelength. An analog read signal is detected from radiation received from a scanned track. For reading the second type, first and second comparators supply respective detection signals if the differences between values of the read signals, separated by a given time interval, are greater than a given positive threshold or more negative than a given negative threshold. A signal recovery circuit derives a binary information signal from the first and second detection signals.

Abstract: A device for coding still images, wherein the still images are segmented into homogeneous regions whereto a specific label is attached. The contents and the contours of the regions are coded by circuitry including a sub-assembly (30) for coding contour information which itself includes a contour detector. On the contours of each region the real direction of orientation on the type of contour edge retained for the transmission is detected, and tested by comparing, for each pair of successive image points of each contour segment, the real direction of orientation thus detected and the instantaneous direction of orientation between these two points. The device further includes circuitry for coding segments traversed in the detected real direction of orientation, and for re-initializing the entire procedure for each of the regions.

Abstract: In a code excited linear prediction (CELP) analog signal coding system sequences from a master codebook (40), which may be a one dimensional codebook, are filtered (42) and then stored in slave codebooks (70,72). Input analog siganls (20)are filtered (34,36) and compared orthogonally (66,78,80) with sequences from the slave codebooks and an optimum pair of sequences are selected. Reduced length sequences from the master codebook may be compared with orthogonalized analog signals since orthogonalized siganls contain some redundancy.

Abstract: A magnetic head having a fixed gap length (g.sub.n) can be compensated to simulate a head with a larger gap length. This magnetic head is adapted to read alternate magnetic media recorded with at least a selected one (x) of a plurality of wavelengths, to produce a head signal. A compensator has a transfer circuit and a disabling device. The transfer circuit is coupled to and driven by the magnetic head to produce a compensated signal that is a function of x, for simulating another gap length (g.sub.1) different from the fixed gap length. The disabling device is coupled to the transfer circuit for selectively preventing simulation of a different gap length.

Abstract: An optical information carrier comprising a substrate, an auxiliary layer bounded by dielectric layers, a thin reflection layer, a dielectric layer, a phase-change layer, a dielectric layer, a tight metal reflection layer and a protective layer. The information carrier is recordable and erasable by a laser-light beam and can be played in a conventional CD player. The auxiliary layer consists of selenium or AlGaAs, and has the property that the absorption increases substantially at temperatures above 70.degree. C. An information carrier comprising this auxiliary layer can be recorded with a lower laser power as compared to information carrier which does not comprise the auxiliary layer.

Abstract: Prior-art telecommunication systems include transceiver arrangements structured, for example, as optocouplers for optically transmitting information, that is in a DC isolated manner. These optocouplers, which may transfer relatively high frequency signals are expensive. When the signal, to be transmitted has a low maximum frequency of about 200 Hz, a more cost-effective transceiver arrangement may be used, which comprises a transmitter means arranged for effecting a change of ambient temperature (a power dissipating resister) and comprises a receiver means arranged for detecting the change of ambient temperature (an NTC resister or a semiconductor element). In an advantageous embodiment transmitter means and receiver means are used in integrated form deposited each on either side of a substrate.

Abstract: In a base band conversion receiver, frequency deviation in the base band signal due to tolerances and drift of the transmitter frequency and of the mixing frequencies in the receiver is compensated by an automatic control. The signal converted to the base band is applied to a channel estimator which forms a channel estimation vector as an estimate of the instantaneous channel impulse responses in a complex bag band representation. A frequency deviation estimator evaluates the changes in time these channel estimation vectors.

Abstract: A digital modulator in which symbols representing bits are encoded and assigned to respective points of constellation of points representing the modulation scheme. The quadrature components of a vector representing each of the constellation points are contained in a truth table (14) in which the columns comprise the respective constellation points and the rows comprise the relative in-phase and quadrature component values. In response to the assignment of a symbol to a constellation point the appropriate column in the truth table is read out in parallel as a binary word and the bits of the word are applied to respective first stages (S10) of a plurality of shift registers (SR1 to SR8) which store the histories of the respective component values for the previous (N-1) symbols.

Abstract: An image pick-up and projection apparatus comprising a projection unit (14), a pick-up unit (11) and a projection screen (9) switchable between a transmissive state and a diffusing state. By arranging an array (15) of elongated prismatic elements on the front surface of the screen, the contrast of the projected image is enhanced and it is avoided that a user (12) can simultaneously see the front of the projection unit and the front of the pick-up unit.

Abstract: A disc player comprises an optical scanning device (13) with a turntable (17), which is rotatable about an axis of rotation (17a) and which has a supporting surface (17b) for supporting an information disc, and with a disc-shaped disc carrier (15), which is rotatable about an axis of rotation (15a) and which has carrying surfaces (51) for information discs. The disc player has a driving device comprising a command element (63) which is rotatable about an axis of rotation (63a) and which has first means for cooperation with guide means to guide the turntable between a play position and a rest position and second means for cooperation with the disc carrier to rotate the disc carrier between well-defined disc-carrier positions.

Abstract: A device for the recording and reproduction of signals on a cassette for a medium comprising a sliding cover which in the device can be moved between a closed position and an open position. The device has a receiving space into which the cassette can be inserted, after which by means of a pivotal lever the sliding cover is opened upon further insertion of the cassette, in that the lever moves from the first position to the second position and thereby moves the sliding cover from a closed position to an open position. The lever is arranged on a movable lever support which can be moved between a starting position and an end position. The sliding cover is opened by snap action.