Abstract: An optical data bus with a statistical access method for the transmission of data between transmitters and receivers in the form of NRZ data provides that every transmitter of a subscriber contains a Manchester encoder which Manchester encodes the NRZ data and deposits such data onto the bus in a Manchester-encoded form. The receiver of every subscriber contains a Manchester decoder for the reacquisition of the NRZ data from the Manchester encoded data and contains a clock recovery device which recovers the clock contained in the Manchester-encoded data. Such a Manchester decoder with the clock recovery device can be constructed in a very simple manner and such a simple structure is disclosed. A very simply-constructed bus state recognition device is also included.

Abstract: A method for correcting a measuring signal which has been generated by an apparatus measuring in contact-free fashion. The apparatus scans a surface to be measured with a light beam, measures the light reflected by the surface by means of an opto-electric detector installation, and generates the measuring signal in dependence upon one or more electrical signals emitted by the detector. In the case of the above-described apparatus, distortions of the electrical signal emitted by the detector, which distortions occur for example through non-uniform scattering ability of the surface to be measured, can result. These distortions lead to measurement errors. Such measurement errors are corrected in the simplest manner possible. For this purpose, the measuring signal is corrected in dependence upon a distortion of an electrical signal.

Abstract: A device is disclosed for contact-free thickness or interval measurement wherein a light source generates a light ray beam which is periodically deflected. A beam divider divides out a light ray beam for reception by first and second light-sensitive detectors which receive light only along a specific optical axis. At least one third light-sensitive detector is provided whose optical axis intersects the light ray beam at a reference plane. Electronic evaluation means are provided for generating from signals of the first, second, and third detectors a control voltage corresponding to a deflection time of the light ray beam and also at least one voltage impulse which is a measure of an interval of a surface of a measured object from the reference plane. A reference voltage is provided and means are provided for generating a corrected reference voltage by changing the reference voltage in a direction opposite to a deviation of the control voltage from a normal operating voltage.

Abstract: A method and apparatus is disclosed for contact-free interval or thickness measurement. A sharply concentrated light beam is periodically deflected over a measuring space having a measuring plane and reference plane situated therein. A beam divider is positioned after the beam deflector and deflects the beam towards first, second and third light detectors. A fourth light detector is also provided to receive reflected light from the measuring plane and reference plane. A first time difference is utilized to control deflection frequency of the light beam; a second time difference controls deflection amplitude of the light beam; a third time difference determines a spacing of the measuring plane from the reference plane; and a fourth time difference corrects for changes in a direction of the light beam such as when a new light source is positioned in the system or when other directional errors occur.

Abstract: A device for contact-free measuring of the distance of an object surface from a reference plane by deflecting a beam of light in a path and detecting a beam reflected along a given line of sight by a detector characterized by providing means for measuring the interval of time for travel of the deflected light beam between at least two specific directions of the beam and between at least one of the two directions and a direction at which the photo detector responds and utilizes the time intervals to determine the speed of deflection and determine the distance of the surface from the reference plane.

Abstract: A system is disclosed for non-contact distance or thickness measurements. A deflectable laser beam scans the object and produces a measuring impulse during a forward and reverse motion when the laser beam hits a point on an object along a sighting line of a measuring detector. A rectangular pulse is produced from each measuring pulse and rising or falling edges of the rectangular pulse are used for measurement. The impulse widths and possible store times of the evaluation circuitry do not influence the measuring result in the system disclosed.

Abstract: A device is disclosed for the contact free thickness measurement of an object. A light source produces a sharply bundled light ray which is divided into two light rays and simultaneously and periodically deflected so as to scan over opposite surfaces of the object. A reference detector determines a time t.sub.O at which two rays corresponding to a zero position of the light deflector strike the object. A first detector picks up light only along a first sighting line which intersects the object at a first point on one surface thereof. This first detector detects a time t.sub.A when one of the two light rays scans across the first point. A second detector picks up light only along a second sighting line which intersects the object at a second point on the one surface thereof. The second detector detects a time t.sub.B when the one light ray scans across the second point.

Abstract: A method and apparatus for the rapid measurement of the distance of an object from a reference point and the speed component of an object traveling vertical to a reference plane is disclosed. A laser beam from a transmitter is periodically sent by a beam deflector through the space in which the object is situated. The laser beam is diffusely reflected from the object and is registered as a measurement pulse on a detector placed near the transmitter. The distance of the object is determined from the time difference between one starting point of a deflected beam segment selected for the measurement and the detector signal. A reference pulse is created in an additional reference detector at a reference time by positioning a swing mirror so that a portion of the laser beam is reflected on a transparent body situated on the reference plane, the reflection then impinging upon the reference detector. The time difference is measured from the reference time to the middle of the measurement pulse.

Abstract: A method and device for the contact-free measurement of the thickness of a workpiece having first and second surfaces which are opposite and plane-parallel to each other characterized by providing a single laser beam, deflecting the laser beam, splitting the deflected laser beam into two sub-beams which are directed to opposite sides of a reference plane, reflecting at least a portion of each of the sub-beams towards the reference plane so that each portion is moved on one of the first and second surfaces of the workpiece from an initial position to a position in which the surface reflects the beam along a given path to a sensing device associated with each of the portions of the sub-beams. By calculating the angle of movement based on a lapse time for the portion to move from an initial position to the position causing the detection of a reflected beam, the distance of the deflecting point on one of the surfaces of the workpiece can be determined.

Abstract: A method and apparatus for measuring the height of a blade of a turbine rotor as the rotor is being rotated characterized by deflecting a laser beam at a given deflection frequency across the path of the moving blade so that a portion of the deflected beam will be reflected by the end of the blade, sensing the reflected portion to produce a reflected signal, synchronizing the speed of rotation of the rotor with the frequency of deflection so that the end of the blade and the deflected beam reach the same point simultaneously and applying the reflected laser signal and a reference signal from the laser beam to an electronic analysis system to determine the height of the individual blade. Preferably, the synchronizing is accomplished by sensing the blade frequency, converting it to a converted blade frequency, comparing the converted blade frequency with the frequency of deflection to obtain an error signal and using the error signal to control the speed of rotation of the rotor.

Abstract: A ranging and velocity measuring system in which a laser beam is periodically deflected through an angular scan by a reference periodic wave and energy reflected from an object is detected and compared with the reference wave to determine range to the object. By measuring the range to the object at two different times, the velocity of the object toward or away from the detector can be determined.