Abstract: A leveling instrument has an image-forming objective, a picture-taking spatial resolution optoelectronic detector, and electronics and a computing unit for driving the detector and evaluating the detector signals. The image-forming objective is subdivided into several zones of field depth designed each as a different aperture plate. Corresponding partial zone of the detector are associated to the aperture plate. The partial zones of the detector may also be designed as individual spatial resolution detectors. Since all level indicators, whatever their distance from the levelling instrument, may be sensed in one of the zones of field depth designed as aperture plates and reproduced by said aperture plate, the image-forming objective need not be manually or automatically refocused nor aligned with respect to the target.

Abstract: A method and apparatus for electro-optical distance measurement. A series of pulses provided by a laser are received as echoes by a receiver. The pulses are each produced within respective intervals having a common predetermined duration. Each pulse is time-shifted relative to the beginning of its corresponding interval. A pulse pattern comprising echo signals for each of a series of pulses is used to determine the distance to an object producing the echoes.

Abstract: The description relates to the measurement of the inclination of boundary areas in an optical system and a device for implementing the process. Starting with an auto-collimation process which determines the inclination of this boundary area in relation to a reference axis from the deviation of a light beam collimated onto the boundary area to be investigated and reflected on a position-sensitive photodetection system, a twin-beam interferometer process with downstream evaluation electronics is provided which permits the separation of the interferogram, intensity-modulated according to the invention, of the boundary area to be investigated from the unmodulated disturbance reflections of those not to be investigated as far as the interferogram intensities in the photon-noise range and thus offers a resolution in the deviation of the center of gravity of the interferogram of the order of 10 nm.

Abstract: A wave front sensor having a focusing optical system (1), a perforated diaphragm (2) with a plurality of perforations (21) situated simultaneously in the beam path (3), in an encoded arrangement, in particular according to and a cyclic Hadamard code, a device (22) for advancing the perforated diaphragm (2), so that a multiplicity of different encoded arrangements of perforations (21) are situated successively in the beam path (3).

Abstract: Process and apparatus for testing optical components (12) or systems which are contained in an apparatus consisting of a focusing optical system (1) and a space-resolving light detector (2) close to the focal plane thereof, it being provided that a source (3), containing a collimator (32), for a narrowly delimited precisely parallel light beam with a plane wavefront is moved rectilinearly in a plane parallel to the wavefront, at a plurality of positions of the source (3) the signal of the light detector (2) is determined, tilting movements of the source (3) perpendicular to the line direction are detected by an apparatus with a second collimator (52) and space-sensitive detector (51), and the aperture of the optical system (1) is scanned twice with line directions rotated relative to one another through approximately 90.degree., and in addition an individual line coming close to the axis of rotation is scanned in a position rotated through approximately 45.degree..

Abstract: The measuring device is used for determining a relative position between a first item and a second item or the image thereof. The items are displaceable or rotatable relative to one another. The first item has a code carrier, which is arranged along a path. The code carrier is provided with a code pattern at right angles to the path. The second item has a code reader oriented on the code carrier path. A computer is connected downstream of the code reader and has means for quantifying the signal supplied by the code reader and for comparing with a stored code image of the code carrier, as well as for calculating the relative position from the comparison result. This measure permits automatic reading of the position, accompanied by a very high measuring accuracy. The measured result can be digitally displayed and, if required, can be directly stored on a data carrier and/or can be further processed in a computer.