Abstract: An apparatus for testing visual acuity, or clearness of vision, particularly when there is impaired refracting medium in an eye, includes a lamp (1) and a pin-hole diaphragm (4) arranged in a light-beam path downstream of the lamp with a single diffraction grating (6), being provided in the light-beam path downstream of the pin-hole diaphragm.

Abstract: A clamp assembly comprises a clamp (12) having two levers (1, 2) linked at middle areas thereof with first ends thereof closing together to form clamping jaws (5, 6) and second, opposite, ends thereof formed as opening grips (3, 4) for separating the clamping jaws, which are spring loaded toward one another. The clamping jaws (5, 6) have forked shapes. The branches of the forks, and the ends thereof, are arranged to be spaced from one another so that they extend across, or extend over, a bridge of a pair of eyeglasses to be placed on inner, upper edges of spectacle glasses (13) or on an eyeglass frame (14). A first lever (2) of the clamp (12) has thereon a clamp coupling element (10, 19, 22, 24) for being selectively attached to, and selectively detached from, an optical-device coupling element (18, 20, 23, 25) on an optical device. The clamp assembly makes possible an easy and quick exchange of optical devices to be attached thereto.

Abstract: A stereoscopic ophthalmoscope for examining an eye including two inner reflection mirrors for guiding light representing the image of the eye toward a pair of external mirrors. Each of the external mirrors serves as an image splitter for dividing the light into two distinct optical observation paths. The first optical observation path is used to produce a stereoscopic image of the eye suitable for binocular viewing. The second optical observation path is used to produce a non-stereoscopic image of the eye suitable for monocular or binocular viewing.

Abstract: A binocular stereoscopic viewing device for examining an eye having a light source and a first light guide for directing light from the light source to the eye to be illuminated. A second light guide redirects light representing the stereoscopic image of the eye. A support mechanism supports both the first light guide and second light guide and is operable for moving in directions towards and away from the eye. A tilting mechanism repositions the first light guide relative to the second light guide for varying the angle at which light from the light source is directed by the first light guide toward the eye to be illuminated.

Abstract: A magnifier for observing a surface includes a housing, a detachable window attachment coupled to a first end of the housing and an eyepiece coupled to a second end of the housing. A light source attachment is coupled to the housing for supplying light to the hollow interior of the housing. The light source attachment and housing each have major axes which extend in different directions and form an angle between approximately 110.degree. and 120.degree.. Photoconductive material serves as a light guide for directing the light from the light source attachment to the window attachment.

Abstract: An opthalmoscope comprises a beam of light projecting along an illumination beam path into the eye of a patient and onto the fundus oculi of the eye, and a condenser system arranged in the illumination beam path. The condenser system includes an element having a nonspherical optically effective surface.

Abstract: A binocular indirect ophthalmoscope is disclosed in which the optical observation axes from the examiner's pupils to the patient's pupil and the optical illumination axis from an illumination source to the patient's pupil are varied simultaneously by a single conveniently located lever. Mirrors reflecting the observation axes and the illumination axis are mounted on a common movable holder in fixed relationship to each other. The lever is coupled to the holder to move the holder in the observation plane upon actuation of the lever and thereby adjust both the observation axes and the illumination axis at the same time.

Abstract: Head-worn apparatus to which an optical device is adjustably coupled is disclosed. The apparatus comprises a headband, a support bow for the optical device rotatably coupled to the headband and a locking mechanism for automatically locking the bow in a viewing position of the optical device and in a rest position of the optical device while permitting the bow to be swivelled between the two positions. An articulated coupling adjustably connects the optical device to the central region of the bow. The locking mechanism always locks the bow in the same viewing position of the optical device so that once the articulated coupling has been adjusted with the optical device in its viewing position, the bow and with it the optical device can be swivelled back and forth between the rest and use positions without having to readjust the optical device.

Abstract: A headband for the mounting of devices carried on the head, in particular medical optical instruments, includes removable cushions which are constructed of an elastic material of stable shape and are located on the headband at regions at which it comes into contact with the head of the user. The cushions include strap profiles with edge strips, which extends along the sides of the cushions and which engage the edges of the headband for securing the cushions thereto.

Abstract: The inventive manual ophthalmoscope is provided with a housing 1 which is closed on all sides and in which the optical components 7, 8, 9, 13, 14 are housed in an entirely dustproof manner. The necessary switching operations for interposing correction lenses 15, 16, lighting field masks, color filters etc. into the illumination and/or observation light path 2, 3 are effected by electomagnetic drives 17, 18, 19, 20 which are adapted to be operated by means of operating elements 21, 22, 23 provided on the outside of housing 1 in optimum positions from an ergonomic point of view. The display of refraction values of correction lenses 15, 16 interposed into the observation light path as well as information deducible therefrom is effected in an optoelectronic manner.

Abstract: What are disclosed are a method for recovering solid matter from a salinomycin culture broth by spray drying a low-fat culture broth in the presence of a physiologically acceptable solid agent preventing agglomeration, and a solid product so prepared.

Abstract: An improved battery handle system which provides for safe use of either a rechargeable storage cell or non-rechargeable batteries. This system comprises a battery handle adapted to hold the storage cell, having a positive pole adapted to interact with the charger to provide recharging of the storage cell as desired. The charger has a biased contact pin which makes electrical contact with the positive pole of a storage cell. However, if a battery handle with non-rechargeable batteries is inadvertently connected to the charger, the pin cannot extend sufficiently into the battery handle so as to contact the non-rechargeable batteries.

Abstract: The invention relates to a process for improving the quality of mixing of liquid especially viscous media in stirred tank reactors, wherein a change in direction of the medium set in motion is brought about at one point or at several points of the inner wall of the reactor at different levels, in a direction vertical to the angle of approaching flow (attack). The process is especially suitable for fermentation reactions.The invention moreover relates to a corresponding stirred tank reactor.

Abstract: An apparatus for charging a rechargeable battery including a comparator element that behaves hysteretically so that the charging apparatus upon switching to maintenance charging after a fast charge, only switches back to the fast charging when the rechargeable battery voltage has depleted sufficiently low.

Abstract: An endoscope includes a light conducting tube having an interior coating of a material having a lower index of refraction than the material of the tube so as to maintain total internal reflection in the light conducting material of the tube, the inner surface of the interior coating being prepared in such a way that unwanted light is prevented from entering the viewing passage.

Abstract: The invention relates to an improved laryngoscope with a mounting for the incandescent lamp which permits its easy removal for replacement purposes. In one embodiment the lamp can be removed upwardly from the handle of the laryngoscope and in other embodiments it can be removed downwardly with a battery housing located in the handle.

Abstract: An endoscope includes a light conducting outer tube and a light absorbing inner tube, with the inner tube being located concentric with the outer tube and being spaced a distance radially inwardly from the outer tube so as to maintain total internal reflection in the light conducting material of the outer tube.

Abstract: The invention discloses an endoscope, and particularly a rectoscope, having an improved means of securing a cover to the head housing of the endoscope using a releasable hinge. In a preferred embodiment a pin removably located in a bore forms the hinge for the cover connection.

Abstract: The present application discloses an examination pattern for use in conjunction with ophthalmoscopes which provides a light transmissive opening at the pattern center to act as a reference point in the examination of the eye.

Abstract: The invention relates to a lighting appliance for generating a light beam for indirect ophthalmoscopy which appliance comprises a housing with a beam outlet aperture through which the beam leaves the housing and first and second means in the housing to respectively modify the color characteristics and the cross-section of the beam leaving the aperture. An externally accessible operating element is provided on the housing which can be independently adjusted to selectively control the first and second means.