Abstract: An apparatus for the application of controlled combinations of temperature, vacuum, pressure and time to seal capsules is disclosed. Also described are methods to seal capsules and to enhance the bonding of the sealed capsules.

Abstract: An exposure and camera control system comprising a keyboard for providing input information relating to film parameters and camera type, a light to frequency converter for providing signals having a frequency proportional to the intensity of light to be used in exposing the film, and a control operatively connected to the information providing keyboard and to the light to frequency converter for determining the film exposure time and for providing signals for controlling film exposure to light and signals for controlling film transport when the exposure is complete. The control includes a microprocessor, programmable memory, and input/output interface components. A display operatively connected to the control provides visual display of information inputs to the control and of calculated quantitites such as exposure time. A printer operatively connected to the control provides a hard copy record of the displayed information.

Abstract: A microtome, in particular an ultramicrotome, has a drive-control system by which the movement of the specimen arm, relative to the knife, is subdivided into a comparatively slow cutting movement and a more rapid return movement. The drive-control system gradually decelerates the specimen arm at the transition, from the comparatively rapid return movement to the slower cutting movement, so that a jerk, which would generate mechanical vibrations in the drive system, is avoided and the specimen arm is smoothly decelerated from the comparatively high speed to the lower speed.

Abstract: A knife holder having two cylinders journaled for axial and rotatable movement are supported by two spaced-apart clamp blocks. The cylinders are axially and rotatably movable in the clamp blocks. Each cylinder has a continuous longitudinal slot of a cross-sectional shape generally complementary to the cross-sectional shape of the knife clamped therein. The axial movement of one cylinder relative to the other cylinder enables the length of knife edge that is exposed to be varied.

Abstract: Foam capsules with telescopically engaged body and cap portions, also known as hard shell capsules, having a special wall structure, obtained by a microdispersion of a gas in a gelatin solution.The capsule body and cap portions are formed by dipmolding the film-forming mixture obtained by a microdispersion of the gas in a gelatin solution; optionally with the inclusion of a plasticizer and/or coloring agent, and/or flavoring agent, and/or foam stabilizer, and/or gelatin extender.By a suitable choice of the gas proportion in the capsule wall and its micronization level, it is possible, within certain limits, to control the capsule wall disintegration speed and its opacity. In addition, inclusion of gas bubbles into the capsule wall lowers the gelatin content for a foam capsule and provides energy saving during the process due to a faster drying of the wall, thereby providing lower cost prices for the production of pharmaceutically acceptable capsules.

Abstract: A handling device for thin sections, in particular cryosections, which serves as a multifunctional device for transferring, pressing, and holding the thin sections. The device possesses a holder for at least one carrier grid, this holder comprising a base plate and a positively-guided cover plate which can be moved onto the base plate. In addition, means are provided for the purpose of clamping the cover plate against the base plate and hence against a thin section which is present on the carrier grid. A separate holder plate is preferably detachably located in the base plate, the carrier grid being permanently attached to this holder plate, which is matched, in shape and dimensions, to the specimen holder of an electron microscope.

Abstract: A cooling apparatus utilizing liquid nitrogen for cooling specimens to temperatures in the range from -100.degree. C. to -195.degree. C. in propane, halogenated hydrocarbons, isopentane, or other cooling media. Freezing of the cooling media is avoided by means of an arrangement wherein the liquid nitrogen cools the cooling-bath container and/or the liquifier only initially, but after the desired cooling-bath temperature has been reached, the liquid nitrogen level is lowered to below the height of a protective shell which results in further cooling being only indirect, via solid/solid contacts and via the gas phase. A constant cooling-bath temperature is ensured by means of a thermostatic temperature-control system while trouble-free standby operation is ensured by means of an automatic system for replenishing liquid nitrogen, and by a system for controlling the level of liquid nitrogen. Safe disposal of the cooling media which may be combustible and/or toxic is provided for.

Abstract: A microtome, especially an ultramicrotome, is disclosed in which a forward-feed system for the specimen arm and/or knife of the microtome comprises a stepping motor which is controlled by a pulse generator and which shifts the specimen arm, and the knife, relative to each other by an appropriate amount of forward feed in accordance with a forward-feed value which is set at one of a plurality of preselector switches. In order to facilitate quick switching over from one forward-feed amplitude to another, permitting the selection of forward-feed amplitudes which differ by an order of magnitude, for example, if semi-thin sections are to be produced during a run of ultra-thin sections, the forward-feed amplitudes set by the preselector switches can be switched, according to choice, to the pulse generator for the stepping motor by means of a changeover switch. This arrangement enables the operator to alter the forward-feed amplitude by one manual action without disturbing the ongoing operation.

Abstract: A circuit for operating and controlling optical apparatus for viewing an object and making a photographic record thereof and having an illuminating light source and a photoflash light source, the circuit including a pulse width modulator for operating the illuminating light source, a flyback converter circuit and capacitor charging and discharging circuit for operating the photoflash light source, a clock pulse source connected to the pulse width modulator and the flyback converter for operating the same, and a delay circuit for allowing the optics to settle before operation of the photoflash. An energy level control circuit monitors the capacitor voltage and stops application of clock pulses to the flyback converter when the capacitor voltage reaches a desired value. A first visual indicator signals when the desired capacitor voltage is reached, a second visual indicator signals a certain condition in the apparatus, and a circuit gives priority to operation of the second indicator.

Abstract: In apparatus for determining the refractive correction for a patient's eye, a plurality of similar test targets are presented to the patient simultaneously, with these test targets being viewed through different trial refractive corrections for the patient to choose between. Magnification differences produced by the different trial refractive corrections are compensated for by altering the size or shape of the different test targets, such that when magnified by the respective trial refractive correction, each test target appears of normal size and shape to the patient, not interfering with the patient's judgment of best clarity.

Abstract: A four-component microscope objective has a numerical aperture of 0.66. When used with a telescope objective as described in U.S. Pat. No. 3,355,234, the objective provides a magnification of 40X and is well corrected for the usual chromatic image aberrations, spherical aberration, coma and astigmatism.

Abstract: An infinity-corrected, semi-apochromatic microscope objective having an N.A. of 0.85 has five elements and provides a magnification of 50.times. when used with a telescope objective having an effective focal length (efl) of 183 mm.

Abstract: A glass faceplate having a central area of required useful diameter surrounded by a narrow ring of opaque glass and an outer glass mounting flange. Light entering the flange or ring is prevented from reaching the central area as stray light or glare in the system and spurious reflections at the interface of the ring and central area are minimized by a refractive index match of the two innermost glasses.

Abstract: A refractor optical system having a new series of spherical and cylinder lenses substantially eliminates the irregular occurrence of additive errors when lenses spaced from the reference plane are used or more than two lenses are combined and permits correction for the significant additive errors by non-additive lens selection is disclosed.

Abstract: A glass faceplate having a central area of required useful diameter surrounded by a narrow ring of opaque glass and an outer glass mounting flange. Light entering the flange or ring is prevented from reaching the central area as stray light or glare in the system and spurious reflections at the interface of the ring and central area are minimized by a refractive index match of the two innermost glasses.

Abstract: A lens is formed of a section of glass clad glass rod ground and polished to a spherical shape of radius of curvature equal to that desired of a face of the lens. Remaining leachable cladding glass is removed leaving the lens with finished spherically curved opposite ends and an adaptability to modification by transaxial cutting and flat face finishing for plano-convex applications.