Abstract: An infrared detector element (20) comprises a flexible continuous film (10) of polymer material which has pyroelectric or other temperature-dependent characteristics and which is also piezoelectric so also generating microphony when it vibrates. In accordance with the invention the mounting arrangement (30,31,32) for the film (10) comprises mutually-spaced supports (32), e.g. tapered ridges (32) of a moulded-plastics substrate (30); the spacing (x) between neighboring supports (32) adjacent to the detector element (20) is sufficiently small and the tension (P) of the film (10) is sufficiently large that the natural frequency of vibration of the parts of the polymer film (10) between these neighboring supports (32) is higher than the frequency bandwidth of the detector, e.g. as determined by the highest operating frequency of a read-out circuit to which the detector element (20) is connected.

Abstract: An addressable memory cell (10) which is composed of an interrupt transistor (20) of the field-effect type whose source (S) is connected to the input terminal (I) of the cell (10) and whose gate (G) is connected to a clock (H, H) and a loop (30) which includes a first inverter (31) which is connected in series with the drain (D) of the interrupt transistor (20) and whose output is connected to the output terminal (0) of the cell (10), and a second inverter (32) which is connected in series, in the loop (30), with the first inverter (31). In accordance with the invention; the cell (10) is made of gallium arsenide and the loop (30) also includes a diode (33) which is connected in the forward direction between the output of the first inventer (31) and the input of the second inverter (32), and a resistance (34) which is connected between the output of the second inverter (32) and the input of the first inverter (31).

Abstract: A focus control system for a camera is described having the possibilities of automatic and manual control, wherein a front lens group and a master lens group are movable. By moving the master lens group both in the automatic control mode and in one of the two manipulation ranges of the manual control mode focus control over a broad range is possible. Thereby maintaining a natured feeling for the user.

Abstract: A control circuit (10) controls a voltage controlled oscillator (15) to cause the signal at the output of the oscillator to have slopes of frequency variation in accordance with biphase encoded data to be transmitted. The control circuit (10) limits abrupt frequency shifts in the oscillator output signal by inverting a sign multiplying the slope of frequency variation, utilizing an amplifier (50) with a controllable inversion state, in response to whether the state of the data to be transmitted, and a state, indicative of whether a frequency control voltage exceeds a zero threshold at sampling instants synchronous with the biphase data, are the same or different.

Abstract: A d.c. blocking amplifier circuit which has a fast start-up time and can be d.c. coupled to other similar circuits or cascaded with differential amplifiers comprising first and second differential amplifiers (40,42 and 44,46) and first and second balanced input lines (52,56), the first input line (52) being connected to the first differential amplifier which in operation amplifies an a.c. signal applied by way of the first input line (52), and the second input line (56) being connected to the second differential amplifier (44,46) which in operation amplifies an a.c. signal applied by way of the second input line (56). Outputs of the first and second differential amplifiers (40,42 and 44,46) are combined to produce an amplified signal which is independent of the d.c. conditions on each of the first and second balanced signal input lines. The circuit is suitable for use in digital paging receivers which operate a battery economizing regime.

Abstract: In a system comprising a collection of signal processing apparatuses and a switching device, each apparatus is connected, by means of a universal connector which is identical for each apparatus, to an arbitrary connection of the said switching device. The signal path between two or more connected apparatuses is established in that a first apparatus supplies a report command for the switching device in a least one further apparatus, after which the switching device finds out to which connector a further apparatus is connected in that said further apparatus in reaction to the report command has supplies an identification signal as a result of which the switching signal recognises the connector to which said further apparatus is connected. Once it has been found out to which connector the first and the further apparatuses have been connected, the switching signal establishes a signal path herebetween.

Abstract: An epilation apparatus is provided having at least one pair of rotatably mounted epilation rollers (3, 4), which are arranged in the region of an opening (2) provided in the housing (1) of the apparatus, are rotatingly drivable in opposite directions and cooperate with one another at their periphery. Associated with the epilation apparatus is a skin protection device, which is arranged in the region of the opening (2), partially covering the epilation rollers (3, 4) and through which the hairs reach the epilation rollers (3, 4) the skin protection device is a strip-shaped web (11) of wave-shaped design in relation to the longitudinal extension of the epilation rollers, (3, 4) the web, has wave troughs (9) and wave crests (10) alternately on both sides and is comb-like on both sides.

Abstract: A zoom lens is described for an electronic camera for still pictures, comprising a front group (G.sub.1), a variator group (G.sub.2) and a main group (G.sub.4). The lens is designed in such a manner that the sum of the spherical aberrations of the front group and the variator group is constant throughout the zoom range and is adapted to that of the main group.

Abstract: An rf generator for magnetic resonance imaging apparatus including a modulator in which a carrier is modulated with an envelope signal, and a transmitter stage which is connected subsequent to the modulator generator in which the implementation of the modulating signal enables the expenditure for the transmitter stage be substantially reduced in that the modulator comprises a first modulator section in which the envelope signal is converted into a series of equally long digital pulses whose density corresponds to the amplitude of the envelope signal, in that k different kinds of pulses are provided, in that during each pulse of a given kind the carrier is always switched on with a given phase position which deviates from the phase positions of the carrier which are associated with the pulses of the other kinds by 360.degree./k or an integer multiple thereof, and in that the resultant pulse-wise switched, preferably square-wave carrier acts as a switching signal for the transmitter stage.

Abstract: The invention relates to a semiconductor device having a semiconductor substrate, on which a semiconductor layer is provided, which includes sunken or buried strip-shaped conducting regions, which have strip-shaped subregions, in which doping elements are present. Semiconductor devices having such so-called quasi unidimensional conductors constitute potentially important parts of electronic circuits or components. According to the invention, the strip-shaped conducting regions and the strip-shaped subregions are located with a side facing the substrate substantially in one plane, which is a vicinal plane of a major crystal surface of the semiconductor body, of which the semiconductor device forms part. The subregions can also have a very small width and thickness of about 0.3 to 2 nm and can be manufactured in a comparatively simple manner.

Abstract: A smart card (1) which includes a random access memory RAM (10) and a read-only memory PROM (7) incorporating a production key (PK), a distributor key (MK), a bearer code (CP) and a serial number (NS) generates a unique number (NU) which is stored in the memory RAM (10) in the card after execution of the following steps of a program which is specific of the card:a - modulo-2 addition and storage in the RAM (10) of the result:PK.sym.MK=KMP,b - the encryption of a unique input message ME, generated by the card, by means of a reversible algorithm (ALG, ALB.sup.-1) using the key KMP:NU=ALG.sub.KMP (ME).

Abstract: An arrangement (100) for determining the position of the energy center (o') of the image (S') of a luminous object by barycentric calculation within a window (122) surrounding said image (S') and covering p.sub.l .times.p.sub.c elements of a charge-transfer matrix (120). According to the invention, the arrangement has:a first mode of operation, during which on the one hand said matrix (120) is read by grouping the N.sub.l lines m-by-m (m<p.sub.l) in the output register (121), whereas on the other hand, the output register (121) is emptied by grouping, in the read arrangement (123) of the matrix (120), l (l<p.sub.c) consecutive elements from the output register (121), so as to determine the brightest zone m.times.l (124) of the matrix defining the approximate position of the image (S') on the matrix,a second mode of operation, during which the matrix (120) is first read, by grouping the lines n-by-n (n>p.sub.l), thereafter, line by line in a zone (125) of k lines (k>p.sub.

Abstract: A device and a method of generating blue laser light having a wavelength of approximately 450 nm by means of an upconversion process, said device comprising a single semiconductor laser which emits light having a wavelength of 640 to 700 nm, and a resonator cavity which comprises a glass composition of heavy metal fluorides, which glass composition contains trivalent thulium ions. The resonator cavity preferably consists of a glass fibre having a core of a glass composition which consists of heavy-metal fluorides containing 0.01 to 1 mol% of thulium fluoride and a cladding with a lower refractive index than the core. The device suitable for generating continuous blue laser light.

Abstract: An integrated semiconductor device including a directional optoelectronic coupler, which coupler comprises two parallel single-mode rectilinear optical waveguides over a total length D, separated by a small distance d, which coupler also comprises four electrodes of the same conductivity type, two on each waveguide, and at least one other electrode of the opposite conductivity type, characterized in that the coupler has an operation which is independent of the transverse electrical and transverse magnetic radiation components, TE and TM, respectively, present in random proportions in the incoming signal, under the condition in which the structural parameters of the coupler render it possible to ensure that the following relations are true: ##EQU1## In which relations: Z is the dimension of each electrode on the waveguides,.phi.TM and .phi.TE are the phase mismatches provoked by the refractive-index changes in the waveguides under the influence of an electric field,L.sub.CTE and L.sub.

Abstract: An input signal (Vin) is applied to a first amplifier (A1) and a second amplifier (A2) via a circuit (M), which amplifiers are both coupled to an output terminal (U) to supply an output voltage (Vuit). For this purpose the circuit (M) generates two mutually complementary signals which are related to the output signal (Vuit) and the maximum signal values corresponding to the individual output signals of the first amplifier (A1) and the second amplifier (A2). The output signal to be supplied (Vuit) consequently dictates which amplifier (A1, A2) is driven into full conduction.

Abstract: A ceramic body of a dielectric material on the basis of barium titanate comprises 0.2 to 0.5 atom % of antimony and/or cerium as the donor material. The grain size of the dielectric material is less than 2 .mu.m. The dielectric constant of the material exceeds 3500 and the material has a high electric resistance which is maintained at a high temperature and for a long period of time. The ceramic material is suitable for use in capacitors, in particular ultilayer capacitors.

Abstract: A laser diode module includes a rectangular box-shaped metal casing having a bottom (B), an even number of guide pins (1-14) being led through the bottom (B) in a standardized DIL order. In addition to the laser diode itself (LD) the laser diode module further includes a metal base carrier (BC) on which the laser diode (LD), a photo diode (PD) and a support (S) for the glass fiber (F) are installed. The laser diode module further includes a guide pin (9) which is inserted in the bottom (B) by means of a feedthrough insulator for electrically connecting the laser diode module to an external transmission line (MT).

Abstract: A description is given of a hard magnetic material whose composition corresponds to the formula RE.sub.2 Fe.sub.17 C.sub.x, RE consisting of at least 70 at. % of Sm. This material has a relatively large uniaxial magnetic anisotropy and a relatively high T.sub.c and is very suitable for use in permanent magnets.

Abstract: A detection device for measuring force and pressure is disclosed which includes a monomode optical fiber (1) into which polarized light is fed and, at the output of the fiber, is detected by a detection arrangement (4, 80, 81, 30, 40, 31, 41), which is sensitive to the polarization of the light. The detection arrangement is provided with means (30A, 31A) for analyzing the light according to at least two different polarization directions, forming an angle comprised between 30.degree. and 60.degree. between them. According to the invention, the device is provided with means (70, 71, 2) for feeding several non-correlated light signals, each polarized differently, into the input of the fiber, and with means (4) for distinguishing between the light signals in the said detection arrangement at the output of the fiber, which light signals have been fed into the input of the fiber. The invention is applied in intrusion detection, monitoring and security systems.

Abstract: Test equipment for a Multi Channel Access (MCA) wireless apparatus includes a Read/Write memory section which operationally replaces an ID.ROM of the apparatus for the purpose of the testing. A personal computer writes area, channel, system, tone group and user code data into the memory section which is read by the operating section in order to configure its channel setting. A measuring device receives code data for a channel setting at which operation is to be checked, sends a corresponding channel designating signal to the wireless apparatus, receives a response signal from the wireless, and forms and sends to the personal computer a result signal indicative of whether the response signal is accepted or rejected. The personal computer operates to send the code data to the measuring device under program control in response to keyboard operation by the user.