Abstract: There is provided a device for dispensing optical fibers into helical grooves of a ring drawn through optical fiber cabling lines. The dispensing device comprises a holder rotating about the ring and including conduits each containing a grooved fiber-guide receiving at least one optical fiber. The fiber-guides are arranged along generating lines of a cone coaxial with the ring and have first fiber-output ends designed to engage in the ring grooves. To disengage the first ends of the fiber-guides from the ring grooves while feeding the ring through the cabling line, the fiber-guides are slidably mounted in the conduits and the device comprises a nut means enclosing a washer in which second ends of the fiber-guides radially, thereby translationally moving the fiber-guides along generating lines of the cone respectively.

Abstract: The invention relates to an immersed type photovoltaic detector comprising a substrate transparent to infrared radiations and a wafer in semiconducting material. A PN junction is formed in the wafer, on the side opposite the substrate, with a zone of conductivity opposite that of the rest of the wafer. The substrate, on the side opposite the wafer, has the form of a hemispherical lens. The substrate and the wafer are welded by a layer of tellurium transparent to infrared radiations after dissolution by the tellurium of the substrate and of the wafer. The detector is advantageously used for the evaluation of lenses.

Abstract: Two optical fibers are connected by a device including a base member having a central groove for aligning and abutting the fiber ends. To connect the fibers quickly without having to dismantle any device members, the device comprises a one piece bent spring fastener having a U-shaped cross-section. Natural flexion of a flexible arm of the spring fastener presses the fiber ends into the groove in the immediate vicinity of a fiber endface connection plane. The other arm is anchored to the base member. To connect the fibers, a tool deflects the flexible arm away from the base member and the fiber ends are slide into the groove. The device is in a very slim-like housing and several can be stacked to create a multifiber connecting rack.

Abstract: The device according to the invention is useful for recognizing binary locking words in a digital train. It comprises six flip flops connected to an AND gate for recognizing the first six bits of the locking words. The first five flip flops are connected to an AND gate for recognizing the last five bits of the locking words. A seventh flip flop makes it possible to confirm and memorize the identification of the first six bits of the locking words and an AND gate, connected between the sixth and the seventh flip flops, ensures erasure of the memorization of the first identification.

Abstract: A drawing wheel is intended for exerting tension on a grooved ring while optical fibers are being laid in helical grooves in the core, in order to stretch the ring in a cabling line. The invention is aimed at defining a radius for the wheel in terms of the dimensional characteristics of the ring so that the fibers are kept longer than the grooves as the ring leaves the cabling line and reverts to an initial tension-free state. The radius of the wheel is such thatR'>(p.sup.2 /(4.pi..sup.2 r))-(r+h)where p and h respectively denotes pitch and depth of the helical grooves, and r denotes radius of a central portion of the core circumscribed by bottoms of the grooves. The wheel radius is preferably on the order of one meter or more.

Abstract: A subscriber television set terminal is linked to a distribution station receiving M television channels in a videocommunication network. The distribution station comprises as many individual channel selectors as there are television channels. A television channel is selected from a terminal by a digital video switching matrix that, for each channel address transmitted in a backward line of a terminal connecting line, connects the addressed channel selector to a forward line in the connecting line.

Abstract: The present invention relates to frequency generation of digital type, said frequencies being able to take values included in the 0.4000 Hz band. The invention consists in using the periodicity of the sine function on (0,2 .pi.), in making samples correspond to each frequency f, each sample being represented by a triplet P, Q, S, P representing the rank, Q being a function of the quadrant to which said sample belongs on (0,2 .pi.) S the sign, in memorizing 1/4T samples of the sine wave of frequency 1 Hz on (0,.pi./2), T being the sampling period, and in causing to correspond to any sample Y.sub.N indicative of the frequency f (Y.sub.N =sin 2.pi.P T) a sample of triplet (P, Q, S) of rank Nf chosen from the 1/4T samples, said correspondence being biunivocal. The invention is applicable to the generation of tones, to inter-exchange signalling in particular.

Abstract: Gain of a photosensitive avalanche member, such as an avalanche photodiode, is stabilized so that a variation in gain of the photosensitive member in terms of temperature is compensated for by applying to the photosensitive member a bias voltage varying with temperature according to a predetermined relationship. The relationship depends on the variation with temperature in the voltage applied to terminals of at least one diode. The gain stabilizing device comprises a temperature-stabilized voltage source, a dc-dc voltage converter having an adjustable gain for applying a bias voltage to the photosensitive member, and at least one diode series-connected between the supply source and an input of the converter.

Abstract: In an optical fiber cabling line where a ring having helical grooves is drawn at a constant translational speed by a main motor, there is provided a system for slaving a rotational speed of an optical fiber feeding and dispensing device driven by motor means to a number of ring groove pitches per second in order to compensate for groove pitch fluctuations resulting from the ring production process. The system comprises roller and cam means coupled to the ring and to the feeding and dispensing device for detecting a difference between the rotational speed and the number of pitches per second thereby converting the speed difference into a voltage variation. The motor means comprises a differential coupled to a gearbox connected to the main motor, and a corrector motor linked to the detecting means so as to drive rotationally the feeding and dispensing means at a rotational speed proportional to a rotational speed set by the gearbox and continuously corrected by the detected speed difference.

Abstract: The elementary memory cells of an image recording and readout apparatus are disposed in a staggered arrangement on a semiconductor substrate 61, each cell comprising a central transparent conducting electrode 66 connected to a column conductor 67 and a peripheral transparent conducting electrode 69 connected to a row conductor 70. Conducting guard electrodes 71 are disposed in subjacent relationship to the row and column conductors.

Abstract: A subscriber station receives and transmits, through two optical fibers, composite signals representative of various services as television signals, videophone signals, hifi sound signals, telephone signals, etc. The station controls exchanges between a switching center and terminals, and separates some signals from composite signals to process specific signals.

Abstract: The present invention relates to echo cancelling techniques and more particularly to an initialization device for an echo cancelling system. The invention comprises means for converting a pseudo-random sequence (u.sub.k) of length N into a sequence of emitted samples (e.sub.k) such that each sample e.sub.k is derived from u.sub.k by e.sub.k =2 u.sub.k -1, multiplying each sample u.sub.(N-M+1+k)mod N with each received sample s.sub.N+k and adding the results k varying between 0 and N-1. The result at instant kT, to within a multiplicative constant, of said additions is then H.sub.M (k), one of the N coefficients at the initial conditions of said echo cancelling device, M being between 0 and N, and k varying from 0 to N-1, with H.sub.M (k)=H.sub.M (k-1)+s.sub.N+k. u.sub.(N+k+1-M)mod N. The invention is applicable to the pulse response of any signal.

Abstract: A 16-quadrature amplitude modulation (QAM) modulator for radio links converts a train of data into signals having a phase selected from sixteen predetermined phase values and an amplitude selected from four values. The modulator divides the data train into two data sub-trains. The two data sub-trains are respectively applied to a pair of four-phase modulators that are fed by a carrier source. The 16-QAM modulator also comprises two phase locked loops each including a voltage controlled microwave oscillator and an associated differential phase detector. The differential phase detector responds to the output of the associated four-phase modulator and the output of the associated voltage controlled microwave oscillator. Predetermined parts of the output signals of the two phase locked loops are added.

Abstract: The present invention relates to a digital frequency recognition device for a receiver of multifrequency PCM signals, and consists essentially in forming characteristic values V(f.sub.i) for each frequency f.sub.i, in forming characteristic values V(f.sub.i.+-.l) for adjacent frequencies of the code in question, in comparing the value V(f.sub.i) with the values V(f.sub.i.+-.l), the result of said comparison making it possible to deduce whether said frequency f.sub.i is effectively recognized. The invention is applicable to the signalling between automatic telephone exchanges or between subscribers and telephone exchanges.

Abstract: Controller for a cooling system utilizing the Joule-Thomson effect for a cryostat, wherein the expansible component consists of a metal rod (20) of very small diameter, inside and coaxial with the tubular envelope (7), one end (21) of this rod (20) is fixed mechanically, and is joined thermally by a transverse bulkhead (22), to the tubular envelope (7) at a point of the latter lying between the warm point and the cold point (10), the other end (23) of this rod is fixed to a fork (16) for operating the needle (13) surrounding the seat (11,12) of the needle and driving the needle (13) through the intermediary of an adjustment component (18), and lastly the said fork (16) incorporates a periphery, preferably cylindrical, which leaves a large annular gap between this periphery and the inside surface of the envelope tube (7).

Abstract: The present invention relates to a line circuit for network line junctor and more particularly to a dialling device. The dialling device according to the invention presents a high impedance for the direct current, the direct current being regulated about a predetermined threshold by means of an electronic choke, the regulation being controlled by a control circuit formed by an RC circuit with large time constant, by a diode and a capacitor. The invention is more particularly applicable to private switching equipment or to subscribers' terminals.

Abstract: The detector of the invention comprises a first semi-conductor wafer of type n, or p, with zones of type p, or n, extending from one to the other of the two faces of the wafer, and a second wafer for processing the signals delivered by the wafer exposed to the infrared radiation. The zones of the first wafer are connected to the face of the second wafer facing the first wafer by studs extending along the face of the first wafer facing the second wafer. The invention makes it possible to obtain an infrared detector for a camera which is quick and economical to manufacture.

Abstract: The system is intended to determine the angular deviation of the missile to direct it into a target. It comprises a laser, a rotating convergent cylindrical lens to convert the laser beam into a flat, elongated, rotating pencil beam. The missile bears one detector scanned by the pencil beam and processing circuits for determining the polar coordinates of the missile and for controlling its rudders.

Abstract: The generator comprises an envelope and two mirrors defining a resonant cavity, in which is maintained a monolithic wave-guide with a capillary. The capillary is formed in a thinned portion of the guide. Two electrodes extend over the thinned portion of the guide. The capillary is circular in cross section, this being obtained by drilling or extrusion of a cylindrical bar made of dielectric material. The circulation of the laser gas is excellent and the laser plasma uniform. The generator has multiple applications, for example in the medical field.