Abstract: A rigid, rod-shaped endoscope for medical applications includes a distal end having a light-permeable distal window and a light outlet disposed adjacent to the distal window, which includes a device configured to prevent the incidence of stray light onto sides of the deflection prism facing the distal window. An endoscope shank includes a plurality of telescoping hollow tubes. An inner fixed optical tube includes a moveable optical deflection prism and an optical system configured to transmit light beams. The optical deflection prism is mounted rotatably on a shaft that is disposed at a right angle to a longitudinal axis of the endoscope. At least one moveable sliding tube is configured to move relative to the inner fixed optical tube in the direction of the longitudinal axis of the endoscope using magnetic forces generated by a plurality of moveable permanent magnets.

Abstract: A rigid, rod-shaped endoscope for medical applications includes a distal end having a light-permeable distal window and a light outlet disposed adjacent to the distal window, which includes a device configured to prevent the incidence of stray light onto sides of the deflection prism facing the distal window. An endoscope shank includes a plurality of telescoping hollow tubes. An inner fixed optical tube includes a moveable optical deflection prism and an optical system configured to transmit light beams. The optical deflection prism is mounted rotatably on a shaft that is disposed at a right angle to a longitudinal axis of the endoscope. At least one moveable sliding tube is configured to move relative to the inner fixed optical tube in the direction of the longitudinal axis of the endoscope using magnetic forces generated by a plurality of moveable permanent magnets.

Abstract: In an electron beam device such as a raster electron microscope, two annular detectors are arranged at a distinct distance along the optical axis between a beam producer and an objective. The distance between the two detectors amounts to at least 25% of the distance between the specimen-side detector and the specimen. The source-side detector serves for detection of back-scattered or secondary electrons which are transmitted through the bore provided through the specimen-side detector for the passage of the primary particle beam. The source-side detector is a conversion diaphragm with an Everhart Thornley detector arranged laterally thereof. The conversion diaphragm produces secondary electrons on impingement of charged particles. By application of two detectors offset in the direction of the optical axis, the yield of the secondary electrons used for image production is increased. The secondary electrons are separated according to their angle of emergence from the specimen.

Abstract: A particle beam apparatus that can be used, in particular in an electron microscope, has a dispersively imaging energy filter in the illumination beam path. A higher energy sharpness of the particles contributing to the further particle-optic imaging, and hence a reduction of the effect of chromatic aberrations, is attained by means of the energy filter. So that voltage fluctuations of the applied high voltage also bring about no drift of the image of the beam producer in spite of the dispersion present after complete passage through the filter, the beam producer is imaged, enlarged, in a plane of the filter that is imaged achromatically by the filter into an output image plane. Because of the high dispersion of the dispersive filter as against non-dispersive filters, the particle beam apparatus can be operated at a higher particle energy within the filter, so that the influence of the Boersch effect is reduced in comparison with non-dispersive filters.

Abstract: The invention relates to a particle beam apparatus, in which very low target energies of the particles focused on the object can be set, with good imaging conditions. For this purpose, the beam guiding tube (5), from the anode (4) to behind the objective (6, 7) is at a high potential, which insures that the particles within the beam guiding tube have a high kinetic energy which is independent of the target energy. A braking electrode (9) arranged after the beam guiding tube, together with the object holder (10) and the object arranged thereon, is at a specimen potential UP which deviates from the ground potential and which has the same sign as the cathode potential UK. The specimen potential UP acts as the decelerating potential, by means of which the particles are braked to energies which can be below the energy value determined by the cathode potential UK.

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: The invention relates to an electron energy filter for electron microscopes as well as to an electron microscope equipped with such a filter. The filter comprises three sector magnets with the deflection field in the first sector magnet being homogeneous. The deflection field in each of the two other sector magnets is an inhomogeneous gradient field. To generate the gradient field, the pole pieces of the two other sector magnets have the form of segments of truncated double cones. The electron beam passes the first homogeneous sector magnet twice. Multipole elements are arranged in front of, behind and between the three sector magnets. The filter has a large dispersion also for high-energy electrons while at the same time providing a compact configuration. All second-order aberrations and the significant second-rank aberrations are corrected by means of the multiple elements.

Abstract: A detector is disclosed which includes an elliptical hollow mirror and a tube having a reflecting inner surface for conducting the light emitted by a specimen under investigation in a scanning electron microscope. A vacuum window is seated at the outer end portion of the tube directly ahead of a receiver.

Abstract: For determining the proper dose of therapy radiation for photocoagulation at the fundus of the eye, the fluorescent radiation excited by the therapy radiation (laser light) in the fundus of the eye is utilized. The fluorescence intensity passes through a characteristic minimum upon the termination of the coagulation process. Apparatus is disclosed for the detection by measurement of this effect. Optical beam splitters are provided to separate the fluorescent radiation from the therapy radiation. An electronically controlled shutter is provided for the passage and blocking off of the therapy radiation. The shutter is closed when the fluorescence intensity reaches a minimum after commencement of coagulation, or when the radiation reaches a predetermined amount, if this occurs before the fluorescence reaches its minimum.

Abstract: Two embodiments of an adjusting device for correcting misalignment in optical ray paths are disclosed. The first embodiment (FIGS. 1 and 3) has two transparent plane plates (21, 22) which are tilted relative to the optical axis and are supported with their mounts (35, 36) for rotation with constant angle of inclination around the optical axis in a tube (37) which is developed as an intermediate structure mountable in a desired location in an optical system. The second embodiment (FIGS. 2 and 5) has two wedge prisms which are displaceable with respect to each other along the optical axis and which can be turned jointly around the optical axis. Both embodiments are useful upon the coupling of a laser beam into a microscope in order to compensate for beam misalignment of the laser, the axis of which is subject to slow drift during operation.