Abstract: A security element for the authentication of a substrate has a pattern comprising optical diffraction elements which are embossed in a carrier material of plastic material and unembossed neutral areas. On the embossing side of the carrier material a reflecting layer covers only surfaces with relief structures of the diffraction elements while the neutral areas which lie between are free of the reflecting layer and are therefore non-reflecting. If the security element is stuck in the form of a stamp onto the substrate and the carrier material is transparent, image portions, which are covered by the stamp, of a feature on the substrate can be discerned through the neutral areas.

Abstract: A security element for the authentication of a substrate has a pattern comprising optical diffraction elements which are embossed in a carrier material of plastic material and unembossed neutral areas. On the embossing side of the carrier material a reflecting layer covers only surfaces with relief structures of the diffraction elements while the neutral areas which lie therebetween are free of the reflecting layer and are therefore non-reflecting. If the security element is stuck in the form of a stamp onto the substrate and the carrier metal is transparent, image portions, which are covered by the stamp, of a feature on the substrate can be discerned through the neutral areas.

Abstract: An apparatus for the optical recognition of documents (1) extends over the entire width of a transfer plane (3). Regularly disposed photoelectric elements (4), whose optical axes create a single sensor plane (5) that is perpendicular to transfer plane (3), receive light (7) as altered by document (1). Photoelectric elements (4) are regularly disposed in a manner in which their optical axes are contained in a sensor plane (5) perpendicular to transfer plane (3). A region (8) of document (1), determined by sensor plane (5), is illuminated by at least one light line (9 or 10) which is inclined with respect to sensor plane (5). The light modified by document (1) is received by photoelectric elements (4). The adjacent light sources in each light line (9,10) are separated by a uniform source distance (A), which is smaller than the sensor distance (B) between two adjacent photoelectric elements (4). The light sources emit light within a narrow spectral width in pulses of short duration.

Abstract: Two signals at different frequencies are optionally amplified or attenuated in an automatic gain control amplifier (1) after their reception, then separated from each other by means of band pass filters (2, 5) and amplitude-modulated by means of envelope curve detectors (3, 6), whereupon the envelope curve signals (z.sub.0 [t], z.sub.1 [t]) are sampled by means of sampling switches (4, 7) once per bit to produce sample values (z.sub.0 [kT.sub.b ], z.sub.1 [kT.sub.b ]) which are passed to a calculator unit (8) whose memory stores values of a decision table which are derived from a probability table. Each table area of the latter contains two probability values of which a first is the probability that the sample values (z.sub.0 [kT.sub.b ], z.sub.1 [kT.sub.b ]) lie in the respective table area if the first signal were sent and a second is the probability that the sample values (z.sub.0 [kT.sub.b ], z.sub.1 [kT.sub.b ]) lie in the respective table area if the second signal were sent.

Abstract: A cartridge for holding flexible bills in first and second stacks, comprises a cuboid housing having first and second openings on oppositely located walls thereof, a mechanism for opening and closing the first and second openings, and pressure plates disposed within the housing which press the first and second stacks against the first and second openings, respectively. The pressure plates are parallel to each other and are movable independently of each other along a common axis. At least one of the pressure plates is movable from its associated opening to the immediate proximity of the other pressure plate, thereby making maximum use of the interior space of the cartridge.

Abstract: A device is disclosed for measuring low-flux magnetic fields with a sensor operating according to the core saturation principle. The sensor is provided with a ferromagnetic core, an excitation coil and a measuring coil. The measuring coil, the excitation coil and the ferromagnetic core are electrically insulated from one another, each being disposed in a single, separate, parallel layer on a support material.

Abstract: A calibration process utilizes two nearly identical sensors. The characteristic output curve of the first sensor is obtained using the measuring outputs of the second sensor. In particular, the first sensor has a characteristic output curve f[x] where x is a physical variable to be measured. The second sensor has an output curve y[x].apprxeq.f[x+a]. Starting from an initially known portion of the curve f[x], outputs of the second sensor are utilized to extend the known portion of the characteristic output curve f[x] of the first sensor into ranges of the variable x where this function is not yet known.

Abstract: A device is disclosed for detecting the presence and/or determining the configuration of a magnetic substance. The device includes a magnetic circuit having a magnetic core and an air gap. Coupled to the magnetic circuit are an excitation coil, for periodically driving the magnetic circuit into saturation, and a measurement coil, for measuring the effective appearing permeability of the magnetic circuit in the presence of the magnetic substance.

Abstract: A circuit is disclosed for measuring reactive energy or reactive power. The circuit comprises a main multiplier, a signal/frequency converter, and a frequency divider all connected in series to form a cascade circuit having an output connected to a display. A 90.degree. phase shifter has an input for receiving a first signal component (e.g., alternating voltage) of the reactive energy or power. A second signal component (e.g., alternating current) is connected to a second input of the main multiplier. The phase shifter has a frequency dependent transfer function K[f]. In order to eliminate the effect of this transfer function on the measurement of reactive power or reactive energy, the arrangement includes a frequency measurement circuit for measuring the frequency of the first signal component and a frequency/signal converter for generating an output signal dependent on K[f].

Abstract: A circuit and method for iteratively estimating Fourier coefficients of one or more Fourier components of a measuring signal utilizes a filter to determine the Fourier coefficients for sampling time k-1. The coefficients are utilized to obtain an estimate of the measuring signal at sampling time k. A subtractor circuit subtracts an actual sample of the measuring signal at sampling time k from the estimate of the measuring signal at sampling time k to obtain a difference signal. The difference signal is inputted back into the filter to determine an estimate of the Fourier coefficients at sampling time k.

Abstract: In an embodiment of the invention, a magnetic sensor comprises an IC magnetic flux sensor and two magnetic flux concentrators (18,19) which are each a section of a ferromagnetic lead frame. A section (18b) of a first magnetic flux concentrator (18), a semiconductor chip (4) and a section (19b) of a second magnetic flux concentrator create a sub-unit (18b;4;19b) having three sandwich like layers (I,II,III). A further section (18a) of first magnetic flux concentrator (18) is a sheet metal object having the shape of a single staircase-like step. The step exhibits a first surface section (22) and a second surface section (23) parallel thereto. One side of first surface section (22) is disposed on top of semiconductor chip (4) in the first layer (I). Second surface section (23) and semiconductor chip (4) are disposed in the second layer (II). A section (17) of a non-ferromagnetic lead frame mounting semiconductor chip (4) and the second magnetic flux concentrator (19) are disposed in the third layer (III).

Abstract: A spectrophotometer useful for measuring absorption or emission bands of a substance irradiated with optical radiation, comprises a light source for producing the optical radiation, a monochromator for isolating light of wavelength (W) from the optical radiation and which modulates the wavelength (W) by a predetermined wavelength amplitude (.delta.W), and a photodetector for detecting the intensity of light passing through the monochromator and for producing a measuring signal in response thereto. The monochromator operates under the control of an electronic control unit which produces a control signal that causes the monochromator to scan across a portion of the spectrum of the optical radiation at a frequency (f.sub.2) to transmit a narrow band of radiation at the wavelength (W). The control unit includes a modulation generator which produces a signal that causes the monochromator to modulate the wavelength (W) by the predetermined wavelength amplitude (.delta.W) at a frequency (f.sub.1).

Abstract: The operation of sticking stamps from a foil in strip form at predetermined locations on a substrate which has motifs printed thereon and which is pulled through at least one sticking station at a predetermined forward feed speed is effected by means of pressing portions, which are raised radially above a pressing cylinder, in the sticking station. The pressing portions have curved pressing surfaces which are parts of a larger cylindrical surface which is concentric with respect to the pressing cylinder and which during each sticking phase roll against a backing cylinder and transfer the stamps onto the substrate. The strip speed of the foil may also be lower than the forward feed speed.

Abstract: A magnetic field sensor, having a charge-coupled device formed in a semiconductor region is disclosed. The magnetic field sensor has first and second contact zones, made of a heavily doped semiconductor material of a first conductivity type, located on an outer surface of the semiconductor region which is made of a semiconductor material of a second conductivity type. The magnetic field sensor also has an insulating layer, located on the outer surface of the semiconductor region, which has passages for sensor connections associated with each contact zone. The charge-coupled device has a plurality of gate electrodes located on the insulating layer which are arranged perpendicularly to the desired direction of charge propagation through the charge-coupled device. One end of at least one centrally located electrode at least partially overlaps the first contact zone while another end at least partially overlaps the second contact zone.

Abstract: A device for measuring or controlling a property of a flow medium comprises a conduit which carries a flow medium. A choke element located in the conduit has a first open operating position and a second closed operating position. A driver drives the choke element from one operating position to the other. A pressure sensor measures the difference in pressure before and after the choke element in said conduit. A processor responsive to the pressure difference calculates a flow or thermal property of the flow medium. The processor comprises an input for receiving a continuous control signal which indicates a desired value of a flow or thermal property of the flow medium and a converter for converting the continuous control signal into a pulse-pause signal for controlling the driver.

Abstract: An apparatus for stacking sheets comprises a belt of predetermined length and an endless belt. The belts pass around fixed axis rollers and three guide rollers which are displaceable for the purpose of varying the belt geometry by means of a carriage. As soon as a sheet passes in one direction of movement into a transportation plane formed by the belts a drive displaces the carriage on a rail into a position above a stack in the same direction of movement, the sheet which is engaged by the belts being conveyed at double the speed of the carriage to one of the guide rollers around which it is rolled for deposit on to the stack.

Abstract: In a sheet feeding device, the local feed of the sheet is measured in the vicinity of respective drive rollers by means of respective sensors for the purpose of aligning rectangular sheets of a preselected set. On the basis of signals from the light sensors, a control device determines an optimum pair of rollers for aligning the sheet. The control device compares the signals of the two associated sensors and adjusts the local feed of the sheet in such a way that the two sensors establish the same local feed, before the sheet leaves one of the selected rollers.

Abstract: A tariff arrangement which is preferably intended for an electricity meter comprises a microprocessor, a data memory and a bidirectional interface for transfer of data with a read-out device. For the duration of a data transfer operation a timing member is activated and by way of a logic circuit inhibits a predetermined memory region to prevent data from being written thereto. The data which are stored in the memory region, for charging purposes, are therefore protected from unintentional alterations during the data transfer operation, even if the software should have corresponding defects. The function of the timing member and the logic circuit can be checked in a simple manner.

Abstract: An ultraviolet-light sensitive photodiode device comprises a first semiconductor photodiode for producing a first current when illuminated by light and a second semiconductor photodiode for producing a second current when illuminated by light. The first and second photodiodes are electrically connected to produce a signal proportional to the difference between the first and second currents. The first and second photodiodes are substantially equal in sensitivity to visible and infrared light, while the first photodiode is more sensitive to ultraviolet light than the second photodiode. Thus, the photosensitive device resulting from connecting the two photodiodes has a spectrally narrow sensitivity to ultraviolet light.

Abstract: A device for optically measuring a pressure difference in a medium by means of a Fabry-Perot interferometer, comprises a transparent plate and a diaphragm block connected to the transparent plate, the diaphragm block comprising a substrate, a measuring diaphragm formed along the inner surface of the substrate, and a spacer separating the inner surface of the transparent plate and the inner surface of the substrate. A first planar mirror is disposed on the inner surface of the plate and a second planar mirror is disposed on the inner surface of the measuring diaphragm so that they constitute the Fabry-Perot interferometer. The measuring diaphragm is shiftable by a distance (H) in response to a pressure difference (.delta.p) exerted on inner and outer surfaces of the measuring diaphragm whereby the optical length (L) of the Fabry-Perot interferometer changes as a function of the pressure difference (.delta.p).