Abstract: It is possible to electrophoretically coat cathode shafts with an emissive layer having excellent mechanical properties by means of a device which comprises an electrophoresis bath and a jig which can be dipped therein and in which cathode shafts can be placed, which jig is composed of a plate of insulation material which is provided on the two surfaces with a first and a second electrically conductive layer, said jig having a large number of apertures in each of which a cathode shaft can be provided in a fitting manner such that each cathode shaft electrically contacts the first electrically conductive layer, and the plate is such a thickness that the side of the shaft to be coated is located at a distance from the second conductive layer, which distance is small in relation to the thickness of the jig, which jig is provided at least with a sealing non-electrically conductive layer on the side of the first conductive layer.

Abstract: The haze around the electron beam spot in the corners and at the edge of the display screen is reduced by using in the electron gun a first grid of a construction such that a multipole lens which is mainly a first quadrupole lens is formed in cooperation with the cathode. The first grid in cooperation with the second grid also forms a multipole lens which is also a mainly second quadrupole lens and which is rotated 90.degree. with respect to the first quadrupole lens. Such a system of lenses in the first grid can be formed, for example, by providing in the first grid an aperture with elongated openings both on the side of the cathode and on the side of the second grid. The longitudinal axis of the elongated opening on the side of the cathode is substantially at right angles to the longitudinal axis of the elongated opening on the side of the second grid.

Abstract: An apparatus is described for the pointwise scanning of an information surface. By arranging an observation objective system asymmetrically relative to a zero-order subbeam of the radiation coming from the information surface, and by utilizing a detector whose dimension in the scanning direction is small, the resolution can be increased.

Abstract: An apparatus for reading a disk-shaped record carrier, the radial scanning position being controlled with the aid of a first servo control loop, which controls a positioning member for the read element depending on a control signal which is read from the record carrier. If this control is disturbed a second servo control loop is rendered operative. This second servo control loop comprises a position indicator for supplying a position signal which is representative of the radial position of the positioning member, a memory circuit for storing the value of this position signal at the instant of failure of the first servo control loop, and a differential amplifier for applying a control signal to the positioning member, which signal corresponds to the difference between the instantaneous and the stored value of said position signal. Furthermore, there is provided a control circuit for changing-over between the first and the second servo control loop and vice versa depending on a built-in criterion.

Abstract: A disc-shaped record carrier having an information track which is divided into a plurality of sectors per track circumference. Each sector is divided into a data section, in which the data can be recorded, and a synchronizing section. This synchronizing section consists of an optically detectable relief structure and comprises an indicator portion and an address portion. The address portion contains the information about the track number and the sector number. The indicator portion serves to define the beginning of the address portion unambiguously and for this purpose has such a relief structure that the indicator signal produced after cooperation with the radiation beam has a frequency which is clearly distinguishable from signal components resulting from the address portion.

Abstract: Disclosed is a microwave range measuring system for determing the distance to an object by means of the phase difference between a transmitted frequency-modulated wave and the wave reflected by and received from the object. The frequency of the transmitted microwave signal is varied between two fixed frequencies f.sub.u and f.sub.o and the signal reflected by and received from the object is converted by means of a signal converter into an intermediate frequency signal from whose total phase shift the distance is derived.

Abstract: An apparatus for reading a disc-shaped record carrier on which per track circumference one picture of a color television signal is recorded. The signal being read is converted to a standard PAL color television signal. The apparatus comprising a command device which by applying command signals to control means can produce a jumpwise radial change in the scanning position on the record carrier, so as to enable the scanning sequence of the recorded pictures to be changed. In order to maintain a standard PAL color television signal in the case of a changed scanning sequence, the apparatus comprises a correction device for the chrominance signal. This correction device is controlled by the command device and comprises a mixing circuit for mixing the chrominance signal with a reference signal of twice the chrominance subcarrier frequency during time intervals prescribed by the command device, and phase correction means for introducing a phase shift of 0.degree., 90.degree., 180.degree., or 270.degree.

Abstract: An optical read apparatus for reading a disc-shaped record carrier. A read element is mounted on an adjusting member by means of which the read element is radially movable. Moreover, there is provided a deflection element for correcting the radial position of the scanning spot. In order to enable an arbitrary information unit on the record carrier to be read with a short searching time, the drive of both the adjusting member and the deflection element is controlled. In order to enable the adjusting member to be moved in a rapid and controlled manner there is provided a position indicator, which indicates the instantaneous radial position of the read element. Moreover, there is included a correction circuit which eliminates the adverse effect of inaccuracies in the position indicator on the searching time.

Abstract: In the disclosed system the speed of a vehicle passing over the sensing coils of the detection system is determined by sampling the envelope voltages occurring during the leading edge portion of the disturbance in the envelope of the received signal produced by an approaching vehicle. This is accomplished by sampling the envelope voltage at a first instant at which the slope of the leading edge is at a maximum and at a second instant occurring at a fixed time interval subsequent to the first instant. The voltage sampled at the first instant is then subtracted from the voltage sampled at the second instant and the difference divided by a voltage sampled at a third instant at which the slope of the leading edge first starts to decrease to produce a signal indicative of the vehicle speed.

Abstract: An opto-electronic focussing-error detection arrangement is described for the detection of a deviation between a radiation reflecting surface and the plane of focussing of an objective system. In the path of the beam which is reflected by the surface a beam-splitting element is disposed and behind said element two radiation-sensitive detectors are arranged which are each associated with one of the subbeams formed by the beam-splitting element. The detectors are grating-shaped detectors and are effectively divided into two detector sections by selection devices, the bounding line being adjustable. A focussing error signal is obtained which is highly independent of a positional error of the radiation-sensitive detection system relative to the beam axis.

Abstract: Method of and a device for manufacturing information carriers form a thermoplastic material, where a thin information carrying die is heated by bringing it into contact with a relatively thick, heated surface and is subsequently separated from the heated surface and pneumatically pressed against the thermoplastic material by a layer of air that thermally isolates the die from the heated surface so that the die may rapidly cool.

Abstract: A device for indicating whether a target is approaching or receding from a Doppler radar or the like comprising a length of wave-guide having a reflective termination at the end at which microwave energy is introduced into the guide, and two mixer diodes spaced along the guide. The diodes are spaced apart along the guide axis by an odd number of quarter-wavelengths and spaced from the termination by an odd number of eighth-wavelengths. Suitably, the diodes are positioned so as to be loosely-coupled to signals within the guide, thereby rendering the selection of suitable diodes much less critical.

Abstract: In a color television display tube having an internal resistive layer the getter is connected to the high voltage contact by means of a metal connection strip. In order to reduce the radio interference radiation level of the tube the connection strip has a metal contact spring which contacts the internal magnetic screening cone of the tube.

Abstract: A transmission arrangement provided with at least one adjustable network whose transfer characteristic between input and output as a function of the frequency .omega. within a prescribed frequency band is approximately equal to C exp [kf(.omega.)], where C is a constant and k a continuously variable parameter.A simple design as well as a large practically feasible adjustment range are obtained because the adjustable network comprises a plurality of channels between input and output and the transfer characteristic of a channel is approximately proportional to a term, different for each channel, from the series of terms of the development of exp [kf(.omega.)] to powers of kf(.omega.), the number of terms corresponding with the number of channels.

Abstract: The bridges between apertures located at the edge of the shadow mask of a color display tube are made at least 20% wider than the others. The width of the bridges increases linearly from row to row from the center to the edge of the mask whereby a continuously varying brightness distribution is obtained. The reproduction mask used in the fabrication of such a shadow mask can be made photographically by exposing photosensitive material through a pattern of bridges, rotating the pattern and repeating the exposure.

Abstract: A radio direction finding apparatus comprising an omnidirectional receiving element (21), an array of directional receiving elements (1.1-1.2N), two log video detectors (15, 16) suited for separate connection to two contiguous elements of said array and a subtraction circuit (27) for generating a signal containing the azimuth data of an r.f. transmitter. In order to select echoes received through the main lobes of the two connected receiving elements from those received through the main lobe of the one element and a side lobe of the other element, the radio direction finding apparatus is provided with a threshold circuit (18) and two gate circuits (19, 20) separately inserted between the log video detectors (15, 16) and the subtraction circuit (27). The threshold circuit (18) passes the applied signals through the gate circuits (19, 20) if the strength of the latter signals exceeds that of the echo signal obtained from the omnidirectional receiving element (21) via a third log video detector (22).

Abstract: A method of manufacturing a color display tube of the refocusing type in which supports of insulation material are secured against an apertured metal plate. The supports are provided with a conductor at least on the side remote from the plate, so that the plate constitutes a first set of lens electrodes and the conductors constitute a second set of lens electrodes. The two sets of lens electrodes form a quadrupole lens in each aperture in the metal plate when a voltage difference is applied between the first set and the second set. The defocusing direction of the quadrupole lens is parallel to the phosphor strips of the display screen.

Abstract: An exposure device for the manufacture of cathode-ray tubes for displaying colored pictures comprises an elongate light source shaped so that the amount of light radiated by said light source increases linearly from zero at the ends of the light source to a maximum at the center of the light source, so that a triangular light profile is obtained. The device may be used to manufacture cathode-ray tubes wherein the display screen is composed of triplets of phosphor lines of very constant width.

Abstract: A record carrier is described on which information is stored in an optically readable structure of trackwise arranged areas and intermediate areas. By giving the information tracks periodic excursions towards and away from adjacent tracks, in a direction transverse to the direction of reading, the period of the excursions being substantially greater than the average period of the areas and the amplitude of the excursions being smaller than the width of the tracks, a control signal for centering the read beam of radiation on an information track can be obtained without the use of additional optical means. The excursions of the tracks have such relative phase that the tracks are in nested concentric relation and one component of the stored information represents the phase of the undulations.

Abstract: Disclosed is a glide path lighting system which is provided with a lens, a light source, and a screen whether or not constructed as a color filter disposed in the focal plane of the lens between the lens and the light source. The lens is provided with a diaphragm having an opening which is wider in the horizontal direction than in the vertical direction.