Abstract: Method for checking a predetermined monitoring area, wherein at least one distance sensor provided in particular in the edge region of the monitored area, which transmits a scanning beam which sweeps over the monitored area in a predetermined scanning movement and thereby changes its direction, which receives the scanning beam which is reflected at boundaries of the monitored area and/or at objects located in the monitored area, and which determines a distance signal representative of the distance of the point of reflection of the scanning beam from the distance sensor and also a direction signal representing the direction of the scanning beam. The distance signals and the direction signals found during the scanning movement define a distance contour function, and an evaluation unit connected to the distance sensor compares the distance contour function which has been found with at least one stored reference contour function representing an expected object contour.

Abstract: The invention relates to a method for determining the light transit time along a measurement path arranged between a measuring apparatus and a reflecting object, wherein a light transmitter contained in the measuring apparatus sends a modulated light signal s(t) along the measurement path, which is received by a light receiver contained in the measuring apparatus, is converted into a received signal e(t), and is evaluated in the measuring apparatus, wherein the light signal s(t) to be transmitted is stored in the form of digital values in a transmitter memory; wherein the stored digital values are sequentially read out and supplied to a digital/analog converter acted on by a clock signal and controlling the light transmitter; wherein the received signal e(t) is supplied to an analog/digital converter acted on with the identical clock signal; wherein the values delivered by the analog/digital converter are deposited in a receiver memory; wherein a correlation function k(t) is formed between the signals s(t) an

Abstract: A method of determining the time point (t.sub.0) of the start of a high frequency oscillation packet triggered as a result of a corresponding external excitation which is extremely tolerant relative to systematic disturbances from various sources consists of determining the times at at least two points of the envelope curve of the oscillation packet with respect to an arbitrary zero time point. Of these two points one is a characteristic point of the envelope curve and the other has an amplitude equal to a predetermined fraction of the amplitude at the characteristic envelope curve point.

Abstract: A spectrometric gas measurement apparatus for the determination of the presence and/or concentration of gases in a spatial region has a spectrometric measurement head which transmits into the spatial region measurement radiation having the spectral ranges necessary for the determination of the gases. Furthermore, a reflector is provided at the spatial region which reflects the light which is passed through at least a part of the spatial region back to the measurement head where it is split up spectrally in an analyzer and then supplied to a photoreceiver arrangement. A measurement tube extending in the direction of light propagation is provided in the spatial region through which the measurement light passes.

Abstract: A light grid consists of a row (13) of adjacent light transmitters (11.sub.i) and adjacent light receivers (12.sub.i) arranged at a distance opposite to the latter. The light transmitters (11.sub.i) and the associated light receivers (12.sub.i) are individually activated cyclically one after the other. A determination is made at each light receiver (12.sub.i) whether a received light signal is present or not on activation of the associated light transmitter (11.sub.i). By considering, during the evaluation, the light receivers (12.sub.i-1, 12.sub.i+1) adjacent to the associated light receiver (12.sub.i) and the light transmitters (11.sub.i+1, 11.sub.i-1) adjacent to the associated light transmitter (11.sub.i), a differentiation is made between an obstacle introduced into the protective field (26) and a defect light transmitter (11.sub.i) and/or light receiver (12.sub.i).

Abstract: The invention relates to an optical scanning apparatus for the identification of a code (11) consisting of sequential light and dark fields which respectively form modules (16, 17, 18, 19, 20, 21, 22) put together from an upwardly restricted integral multiple number of base running lengths (B1), to a module width (M), with a predetermined number of sequential modules (16, 17, 18, 19, 20) and base running lengths (B1) in the code forming a mark (25). The optical scanning apparatus guides a light bead (13), the extent of which is less than the base running length (B1) and at most only fractionally larger than the base running length (B1) of the code (11), over the modules (16, 17, 18, 19, 20, 21, 22) in sequence. By means of its light receiver (15), the light scattered back from the regions of the code (11) met by the light bead (13) is received, and a corresponding electrical signal is transmitted at the output (24). A sequence of individual pulses is formed by differentiation and rectification.

Abstract: A safety switching arrangement for the switching on and off of the power supply (11) of two actors (12a, 12b) for example relays, which, in dependence on the switching on of the current, and in dependence on a sensor switching signal (13a, 13b) jointly set a working apparatus (22) in operation, the safety switching arrangement comprising two main switches (14a, 14b) arranged between the power supply (11) and each preferably earthed actor (12a, 12b).

Abstract: An apparatus for measuring the transit time of electromagnetic waves operates with pulse frequencies (9, 10), conducted in a feedback loop (12) which are supplied after passing through a measurement path (13) or through a reference path (14) to a resonator (35). As a result of an 180.degree. phase-shift of the last pulse (10) of each pulse sequence (9, 10) the resonator oscillation collapses abruptly at a specific point in time. The directly preceding zero passage of the resonator oscillation defines the time of reception of the pulse sequence.

Abstract: A bar code reader for an article (17) which is moved at least substantially in one direction (26) has a scanner (12) which generates a scanning light beam (11) which scans a surface (18) of the article (17) linewise, a light receiving arrangement (13) which includes an electronic evaluation circuit (14) with which bar codes (16) applied to the surface of the article (17) and scanned by the light beam (11) can be recognized and which is arranged outside of the parth of movement (20) of the article (17) and directed towards the front surface (18) of the article (17) as seen in the direction of movement.

Abstract: A laser radar has a pulsed laser (11) which controllably transmits light pulses (12) into a measurement region (13), a photoreceiver arrangement (22) which receives the light pulses (12') reflected back by an object (14) located in the measurement region (13), and an evaluation circuit which, taking account of the speed of light, determines a distance signal characteristic for the spacing of the object (14) from the time between the transmission and reception of a light pulse. Between the measurement region (13) and the pulsed laser (11) there is arranged a light deflecting device (15) which deflects the sequential light pulses at increasingly changing angles into the measurement region and simultaneously transmits to the evaluation circuit an angular position signal representative for its instantaneous angular position. The evaluation circuit derives the location of the object within the measurement region from the spacing signal and the angular position signal.

Abstract: A comparator circuit having a signal input and at least one signal output having an ON-state and an OFF-state, wherein the ON-state represents an input signal lying above a pre-given switching level V.sub.s and the OFF-state represents an input signal lying below the switching level V.sub.s. The comparator circuit has two comparators, the signal inputs of which are each acted upon by the input signal, wherein both the comparators are wired together in such a way that a switching on of the first comparator produces a signal corresponding to the ON-state of the comparator circuit and the switching off of the second comparator produces a signal corresponding to the OFF-state of the comparator circuit.

Abstract: The invention relates to a method for the supervision of a switch, in which a switch supervision signal (CA1, CA2, CB1, CB2) is generated and transmitted to the switch contact to be supervised, and in which the switch supervision signal (CA1, CA2, CB1, CB2) returning from the switch contact is detected and compared with the emitted signal. A coded signal is used as switch supervision signal (CA1, CA2, CB1, CB2) and this coded signal is transmitted serially to the switch contact to be supervised.

Abstract: An optical sensor device for detecting reflecting objects (11) has a light pulse emitter (12) and a light receiver (13) connected to an evaluation circuit (14) having a pulse generator (17) and a reception signal processing stage (24) which only emits an object detection signal when the light pulses or light pulse sequences received by the light receiver (13) lie above a switching threshold. The evaluation circuit (14) has a pulse emission influencing and triggering stage (15) connected in parallel to the reception signal processing stage (24) which triggers the emission of the following light pulse by the pulse generator (17) only when a detected variable disturbing signal has disappeared.

Abstract: The invention relates to an optical inspection apparatus comprising an illuminating means which has a linear light source (11) and a concave cylindrical mirror (10) which forms an image of the light source (11), with the cylindrical axis of the cylindrical mirror extending essentially parallel to the light source (11) in order to generate an illuminated strip (31) on a web (12) to be monitored, with the illuminated strip preferably extending over the entire width of the web (12). By means of an optical system (24) a light receiving means forms an image of an inspection line (32) extending on the material web (12) at the center of the illuminated strip (31) on a row-like photoreceiver arrangement (25), so that light emerging from the material web (12) is detected. The photoreceiver arrangement (25) is connected to an electronic processing circuit (26).

Abstract: A distance measuring apparatus has a photoelectric light transmitter (11) and a photoelectric light receiver (12) which alternately direct light via a measurement path (14) and a reference path (15) to a single photoreceiver (20). The distance from a target (13) is determined by measurement of the transit time differences via the measurement path (14), on the one hand, and via the reference path (15), on the other hand. The light transmitter (11) contains two laser diodes (18, 19) which can be electronically switched in a complementary manner of which the one sends the light trains to the measurement path (14) and the other sends light trains to the reference path (15). Both light wave trains are alternately received by the same photoreceiver (20) which is connected to an electronic processing circuit.

Abstract: A light barrier grid is described with several light sources (5) arranged alongside one another and light receivers (6) which are each associated with one light source. A light source control (9) and also a receiver control (10) are provided in order to energize the light sources and the light receivers individually and in time sequence for the transmission or reception of light pulses. The light receivers (6) are energizable by the receiver control (10) in dependence on the received light pulses for synchronization with the light sources (5).

Abstract: An optical hole seeking apparatus for webs (17) advanced in their longitudinal direction has two laser scanning devices (12, 15) which are arranged spaced apart along the web with a respective light receiving arrangement (11, 14) operating in reflection being associated with each laser scanning device. The two light receiving arrangements (11, 14) are connected to an electronic processing circuit (18) in which the two received photoelectric signals detected at the same position of the web (17) are correlated and then investigated to see whether they are the same or not.

Abstract: An apparatus is described for generating a light curtain which includes an originally spherical strip-like concave mirror 10 and a light deflecting element 12 arranged in the vicinity of the focal point of the concave mirror. The light deflecting element 12 guides a bundled light beam periodically over the concave mirror 10. The strip-like concave mirror 10 is twisted within itself in such a way that each surface portion of the concave mirror 10 which is illuminated during a complete sweep of the light beam extends at at least substantially the same angle to the beam axis in a plane perpendicular to the scanning direction.

Abstract: The invention relates to an optical scanning apparatus for the seeking of faults on throughmoving material webs (29) and comprises at least one light source, a mirror wheel (12) arranged in a housing (13) which periodically deflects a light beam produced from the light source in order to generate a scanning beam with which the material web (29) can be scanned transverse to its direction of through-movement (B) along a scanning line (21). A light deflecting device (16) is provided in the housing (13), is arranged after the mirror wheel (12) and brings about a multiple folding of the scanning beam path out of the plane of the fan of scanning beams. The mirror wheel (12) is arranged in the housing (13) with its axis of rotation (14) above one end of the scanning line (21'), with the housing with the optical components (25, 16) arranged therein forming a main scanning module (10).

Abstract: An interferometric gas component measurement apparatus has a light source (27), a measurement path (30) which contains the gas components to be measured, a polarizer (11), a double refracting plate arranged with its optical axis at 45.degree. to the polarization direction, two doubly refracting plates (14, 20) arranged with their optical axes at 45.degree. to one another and an analyzer (13). The light which passes through the measurement path is concentrated into an output gap (32) and reflected via a holographic concave grid (33) onto a diode row (22). The thickness of the individual plates is so selected that specific linear combinations of the thicknesses result in phase displacements between the beams polarized perpendicular to one another in the plates, with these phase displacements corresponding to the reciprocal of the quasi-periodic line splitting of selected vibration and/or rotation bands of the gas molecules of the gas components to be measured.