Abstract: A head-worn viewing device for alleviating night blindness includes an image intensifier tube between periscopic reflectors with an objective lens in front of the upper reflector and an eyepiece lens behind the lower reflector. The objective and upper reflector are mounted for rotation together about a pivot so that, for short viewing distances, a continuous adjustment is provided which will refocuss the objective at the front plane of the intensifier tube and compensate for the parallax of the periscopic reflectors.

Abstract: A circuit for processing the a.c. output of a tachogenerator whose frequency is proportional to the speed of a rotor of the tachogenerator, said circuit including voltage level detection means responsive to said a.c. output, key pulse producing means responsive to at least one output of the detection means to produce a key pulse whose duration is inversely proportional to the rotational speed, first gating means responsive to an output of the detection means and an output of the key pulse producing means to produce a reset pulse after a predetermined period in the interval between each key pulse, and a voltage generator responsive to each reset pulse to provide a predetermined output level and responsive to each key pulse to ramp that output level at a predetermined rate for the duration of that key pulse, whereby the output level of the voltage generator during each said predetermined period is a predetermined function of the rotational speed.

Abstract: The invention relates to an image display cell in which a 4,4'-bipyridinium compound is used as a reduceable redox material. According to the invention said redox material is dissolved in a cell medium which contains a mixture of water and an electrochemically inert organic solvent. A suitable organic solvent is, for example, dimethyl sulfoxide. As a result crystallization of the solution takes place only at temperatures far below 0.degree. C so that the picture display cell can also be used at lower temperatures. The 4,4'-bipyridinium compound may be so chosen that the resulting picture can be erased directly electrochemically without the use of an auxiliary couple.

Abstract: A black-white or color television camera comprising a pick-up tube, provided with a signal electrode composed of separated strips. Prior to a line scan to be performed by an electron beam, the signal electrode strips are connected to a reference potential. After a scan the strips are through-connected successively through associated switches for supplying information. The switch outputs are alternatingly, in at least two groups through-connected and connected to at least two output leads. Always two stitches, which are connected to two adjacent strips are closed simultaneously. In this way it is avoided that a capacitive voltage distribution across the strips and switch inputs influence the picture signal obtained in a disturbing manner.

Abstract: A metal vapor discharge lamp includes a discharge tube with main electrodes at each end. A starting electrode extends around at least an axial portion of the tube intermediate the main electrodes, one main electrode is connected to the starting electrode by a first resistance and the other main electrode is connected to the other electrode by a second resistance. At least one of the resistances has a temperature dependent characteristic which is substantially more positive than the other resistance.

Abstract: A system for recording a color television signal. The color information is recorded as an amplitude modulation. This color information consists of a first and a second color-difference signal, which two color-difference signals are transmitted in a line-sequentially alternating exhibiting a 90.degree. phase-shift during consecutive line periods. Third and fourth additional signals are quadrature-modulated with the first and second signals, respectively. Each of these additional signals comprises the difference between one of the color-difference signals during a selected line period and the value of the same signal during the preceding or next line period.

Abstract: A current stabilizing circuit comprises a difference amplifier having a defined offset voltage which provides a current which is independent of the operating voltage applied across the circuit. The offset voltage is obtained by using an emitter-coupled pair of transistors with mutually differently current densities as the input stage of the difference amplifier.

Abstract: A method for aligning a deflection unit on an in line CRT uses a multipole field generated by the deflection unit. The center beam is turned on and the deflection unit aligned until it makes a single dot pattern on the CRT screen.

Abstract: Time division multiplex telecommunication exchange in which each bit group received is compared, in the incoming line circuits, with the preceding bit group. When two successive bit groups are equal, the second group is not supplied to the switching device which serves for the exchange of data between the connected transmission lines. The outgoing line circuits retransmit the bit group when no new bit group is received from the switching device within a predetermined time.

Abstract: A high-pressure discharge lamp having at least one electrode fabricated by an isostatic compression process.

Abstract: A textured continuous filament yarn is obtained by drafting in a wet condition a sliver or a roving, which comprises at least staple fibre material, by combining the thinner fibre strand so obtained with at least one continuous filament to form a filament-fibre blend and by bonding the staple fibres to the continuous filament. The staple fibres may be bonded in a random position to the continuous filament or parallel or substantially parallel to the continuous filament. In the latter case the texture properties become apparent after processing of the yarn into a woven or knitted fabric and finishing such a fabric.This is a division of application Ser. No 695,935, filed June 14, 1976, now abandoned.

Abstract: An arrangement for simultaneous two-way data transmission of data signals with a given symbol frequency over two-wire circuits of a type found in telephone networks or of a comparable type. The arrangement comprises an echo canceler with an adaptive filter for producing from transmit channel signals approximated echo signals which are differentially combined with receive channel signals for forming substantially echo-free residual signals. A special type of code conversion is employed in the transmit channel, whereby p-level data symbols are converted into modified p-level data symbols which are thereafter converted into (2p-1)-level data symbols. The echo canceler comprises a digital adaptive filter to which the modified p-level data symbols and the residual signals with a sampling frequency equal to the symbol frequency are supplied.

Abstract: Sensor for measuring the oxygen concentration in the exhaust gases of combustion engines, in which zirconium oxide is used as active material. The improvement relates to a composite filter so that the response is great and the contamination at the same time low. For practical applications the life is consequently attractive.

Abstract: A hysteresis threshold circuit including two complementary transistors and an output transistor with an injector controlled by the collector of the second complementary transistor. The emitters of the second transistor and of the output transistor are interconnected, while the input of the circuit is constituted by the emitter of the first complementary transistor.

Abstract: In rotary anodes which are journalled on two sides a problem occurs, notably as regards the bearing which is arranged on the side of the anode disc which is remote from the rotor. The problem involves excessive discharge of heat via the shaft and the bearing. A possibility of reducing the quantity of heat applied to the bearing consists in the increasing of the length of the anode shaft to increase the heat resistance. However, the length of the X-ray tube is then also increased. The invention provides a combination of smaller length, substantially free choice of the material of the anode shaft and hence overcritical speeds for the tube during operation by forming the anode shaft as a hollow rotor shaft coupled to the anode disc and a further shaft journalled at both ends to the respective bearings and connected to the hollow shaft.

Abstract: A laundry washing machine which comprises a driven laundry holder rotatably mounted within a separately rotatable driven washing liquid container, the respective axes of rotation of the holder and the container intersecting each other.

Abstract: A peristaltic pump comprises two concentric cylinders at least one of which includes a plurality of piezoelectric elements which are successively electrically energized to produce moving seals in the region between the cylinders.