Abstract: The invention is directed to a zoom system for at least two stereoscopic viewing beam paths and includes a multi-element pancratic magnification system as well as an afocal inverting system arranged downstream of the pancratic magnification system at the viewing/documentation end. The inverting system images the stereoscopic pupillary plane or the apparatus pupils of the viewing/documentation unit approximately in the center of the pancratic magnification system. The zoom system is especially suitable for a stereomicroscope.

Abstract: A process for the optical spatially resolved determination of density distributions in biological tissues includes as a first step irradiating a biological tissue by directing a locally confined beam of electromagnetic radiation at an incidence position of the tissue; keeping the incidence position fixed; determining the thickness of the tissue being irradiated; and sensing and recording the directly transmitted radiation component and the scattered radiation component in a spatially resolved manner over a defined spatial angle. As a second step, the incidence position is changed and the first step is repeated. As a third step, the second step is repeated a number of times to obtain a reconstructive representation of the tissue through which the radiation has passed, based on the spatially resolved recordings of the transmitted and scattered radiation components and the tissue thickness as determined in each repetition of the first step.

Abstract: The method is used to determine the elastic bending behavior of coordinate measuring machines as a result of the measuring force and the position of measuring slides in the measuring range of the machine. Correction values are determined, which are used to compensate for measuring errors caused by machine bending. The correction values are a function of the position of the measuring slides and on the measuring force between the probe of the coordinate measuring machine and workpieces within the measuring range, and are established and stored for several positions. The method can be combined very advantageously with known methods for the correction of guideway errors, which were developed on the basis of a rigid model, and with methods for the dynamic correction of machine deviations caused by vibration of machine components.

Abstract: A cooling device for a pulsed laser includes a cooling circuit with a cooling medium whose volume is increased in the pulsed excitation process.

Abstract: Measured position data (Px, Py, Pz) are combined with stored correction values (DB) describing the elastic bending behavior of a coordinate measuring machine in that parameters characterizing the bending behavior are determined for several positions of the probe of the machine within the measuring range (30) of the machine, the acceleration-dependent components of these parameters are determined and stored in the form of correction values (c11, c22) which describe the bending behavior of the coordinate measuring machine as a function of the position (Px, Py, Pz) of measuring slides (22, 23, 24), and at least of the acceleration (ax, ay, az) of the measuring slides introduced via the drives, the correction values being combined with measured position data (Px, Py, Pz) of the coordinate measuring machine in subsequent coordinate measurements on workpieces.

Abstract: A prism component group is provided in a pivotable binocular tube assembly for a stereomicroscope. The prism component group is configured as a deflection prism with two roof prisms cemented thereto. The two roof prisms are offset relative to respective ones of the optical axes of the stereoscopic component beam paths.

Abstract: The invention is directed to a backlash-free cam drive which can be subjected to an impact load. The cam drive includes: a housing defining a longitudinal axis; a cam follower assembly mounted in the housing so as to be displaceable along the axis fixed against rotation about the axis; an adjusting member mounted on the housing so as to be rotatable about the axis and relative to the cam follower assembly; and, a cam formed in said adjusting member so as to define two mutually adjacent guide cams extending along a guide path.

Abstract: A photomicroscope includes a port for a still camera (11) and an additional video camera (14). The video image of the video camera (14) serves both for the operation of a passive autofocusing system (23, 24) and for the determination of the exposure time for the still camera (11). The image areas that are used for exposure metering can be selected via a control panel (27). The integration time of the video camera (14) can be varied up to the range of minutes. The selected image areas are superimposed on the object image.

Abstract: For the correction of measurement errors, due to vibration, of coordinate measuring devices, the time course of the interfering vibrations is stored by means of sensors (a.sub.x, a.sub.y, a.sub.z) on a vibrating portion of the coordinate measuring device. The measured values of the sensors are adjusted with previously determined and stored correction parameters, which describe the natural frequency (.nu.) and the damping constants (.delta.) of the vibrations and also the amplitude and phase information of the characteristic modes (G.sub.r) of the vibrations contributing to the interfering vibrations. The measurement errors, due to vibration, of the coordinate measuring device at the instant of probing are then calculated from the time course of the corrected measurement values of the sensors (a.sub.x, a.sub.y, a.sub.z).

Abstract: The invention is directed to an illuminating arrangement for selectively providing a projection microlithographic exposure apparatus with various types of illumination including conventional illumination having an adjustable coherence factor (.sigma.), illumination via an annular aperture and symmetrically inclined illumination from two or four directions.

Abstract: The invention is directed to an intracavity Raman laser with a collimated beam path in the Raman medium 10. The intracavity Raman laser includes a single-mode Stokes resonator, a mode stop 13, a telescope 3 for adapting the laser rod 20, a single mode also for the pump laser and a deflecting mirror system 4 for a more compact arrangement. The mode volumes of the pump laser and the Stokes resonator are matched.

Abstract: An X-ray microscope has the following features: a pulsed x-ray source that delivers an intense line radiation, an annular condenser that focuses the radiation of the X-ray source on the object to be investigated, an X-ray optics constructed as a micro zone plate that images the object with high resolution on an X-ray detector, and a phase ring positioned in the rear focal plane of the micro zone plate and applies to the zero order X-ray radiation coming from the object a phase shift, with respect to the higher order radiation deflected by the object structures, which is determined by the thickness and material of the phase ring. The phase shift amounts, for example, to 90.degree. or 270.degree..

Abstract: A gas laser 1 such as a .sup.13 CO.sub.2 -laser emits at two different wavelengths (.lambda..sub.1, .lambda..sub.2) with a sine-shaped adjustment of a resonator mirror or a grating 13 such as a Littrow grating. The gas laser emits radiation at the two desired wavelengths (.lambda..sub.1, .lambda..sub.2) in two mutually adjacent intervals of the resonator length L because of a suitable dimensioning of the grating 13 with respect to grating structure and angle position, the outcoupling factor of the outcoupling mirror 12, the resonator length L and the composition of the gas of the laser. The laser emission is inhibited at the crossover between the two intervals and the sine-shaped modulation (for example with a piezo element) of the resonator length L is essentially symmetrical about this crossover. The invention is also directed to an arrangement for detecting a substance such as NH.sub.3 in a flue gas.

Abstract: In an insertable accessory module for a stereo microscope, in particular an operation microscope, two optical elements are pivotably arranged in the parallel observation beam paths after the main objective. A continuous variation of the stereo angle is possible by pivoting about two pivot shafts that are oriented perpendicular to the observation beam paths.

Abstract: In a microscope with a laser illumination, the laser beam is coupled in over the reflected light illumination beam path from the rear side of the microscope stand. The reflected light illumination reflectors are received in a slide with several switching positions. In one switching position, the slide is fitted with a fully reflecting mirror. The position of the fully reflecting mirror is monitored by sensors. The sensors are coupled to a shutter, such that the laser beam is only released when the fully reflecting mirror is inserted. The microscope is constructed as a laser scanning microscope of the inverted type. Sensors are also provided on a pivotable arm that supports a housing. The housing holds a transmitted light condensor and folding mirror above the object stage, and protects against inadvertently looking into the laser light.

Abstract: A laser cyclo-photocoagulation in the eye is monitored on-line by means of an ultrasonic biomicroscope, i.e., visual representations of the treated field, inclusive of the effects obtained in the tissue, are provided continuously on a display placed at the disposal of the attending doctor. The doctor decides, by means of the generated ultrasonic images, on the course of the further treatment. The choice is possible between different operating modes of the ultrasonic biomicroscope.

Abstract: The invention is directed to a stereomicroscope having a main objective of variable focal intercept. An optical element is provided in each of the two stereoscopic component beam paths to provide a parallel displacement of the particular beam path. A coupling between each displacement of the two stereoscopic beam paths and the actual adjustment of the focal intercept of the main objective is also provided in such a manner that a preselectable constant stereo angle results even when there is a variation of the focal intercept of the main objective. In this way, a physiologically constant viewing impression results for the viewer.

Abstract: The electronic system (20) of the probe head of a coordinate measuring machine permits the digital setting of parameters which determine the nature and manner of signal processing, such as trigger levels, the characteristic of frequency filters, and time intervals between several coherent probe signal pulses. Different parameter combinations are stored together in data files which can be called up in accordance with the selected measurement task or in accordance with the probe configuration which has been installed in probe head.

Abstract: The invention is directed to an electron-optical imaging system such as for an electron microscope. The imaging system has magnetic lenses, current and voltage sources corresponding thereto, a computer, a permanent memory and a touch panel. The electron microscope is manually calibrated when first taken into use by a discrete sequence of different operating conditions. Polynomes of the second degree are adapted to the experimentally calibrated parameter values for the lens currents. The computer polynome coefficients are stored in a permanent memory. Operating states are adjustable via the touch panel on the operating console of the electron microscope. These operating states lie between the calibrated operating states. The lens currents necessary for these operating states are computed in the computer based on the function coefficients stored in the memory and are subsequently emitted to the current sources by the computer.

Abstract: An applicator for treatment of an elevated internal ocular pressure by means of laser radiation has a handpiece, which releasably surrounds a fiber optic light guide on its exit side end. A sleeve portion is releasably connected to the exit side end of the light guide, a condensing optical element being provided in the sleeve portion, optically dimensioned and arranged in the sleeve portion at a distance from the exit side end of the light guide such that the applied laser radiation can be focused in the ciliary body of the eye on contact of the sleeve portion with the surface of the eye.