Abstract: An optical electronic device such as a photographic camera having an objective optical system for forming two images of the same object laterally offset with respect to each other, and a photoelectric receiving device receiving the offset signals. The photoelectric receiving device includes a pair of individual photoelectric receivers upon each of which one of the images of the object is incident. The individual receivers have approximately equal receiving areas which uniformly increase laterally from one side to the other and each receiver provides electrical output signals to an electronic difference circuit.

Abstract: Disclosed is an amplifier for electrical signals obtained by means of a photoelectric transducer as a function of the intensity of illumination incident upon said transducer, comprising an operational amplifier adapted to be connected in series after the photoelectric transducer and having a feedback branch, wherein the feedback branch of the operational amplifier includes an electrical element having a nonlinear characteristic connected in parallel with a resistance.

Abstract: The invention relates to an optical correlator comprising an optical system for imaging an object space, a spatial frequency filter disposed in or close by the image plane, and at least one photoelectric detector assigned to said spatial frequency filter. According to the invention the spatial frequency filter is a raster, the structures of which extend in the direction of the perspective vanishing lines of the image of the object space and/or perpendicularly to at least one of said vanishing lines. The size of the structure elements and/or the distance between the elements constituting the raster structure are chosen according to the distortion of the perspective image.

Abstract: Disclosed are zirconium-containing borosilicate glass compositions having a refractive index n.sub.e between 1.55 and 1.72, and Abbe number .nu..sub.e between 50 and 34 and a negative anomalous partial dispersion value .DELTA..nu..sub.e between -3.0 and -7.7. Also disclosed is a process for the production of such glass compositions.

Abstract: An apparatus for electrooptically focusing the objective in a single lens reflex camera provided with a focusing screen and a split image wedge rangefinder, where focus detectors are used in which an image segment is scanned in an image plane. The focusing window of the focusing screen provided with a split image wedge rangefinder (5) is followed by a pentaprism (8) having a first plane reflecting surface which is partly reflecting. The scanning grating (14) and the photoelectric detector system (17,18) are mounted in the direction of the light beam behind this plane surface of the pentaprism and along the optical axis deflected by one of the wedges (5a) and an optics (11) is present along the optical axis to image the plane of one of the wedges (5a) into that plane where the scanning takes place.

Abstract: A photographic camera arrangement is disclosed for cameras which are intended to accept only certain interchangeable lens assemblies. For identification purposes, the bayonet segments of the camera housing and the bayonet segments of the lens assembly, respectively, are furnished with depressions, notches or like recesses and with stubs, ridges or like protrusions which will permit attachment of certain lens assemblies to only a given camera or series of cameras.

Abstract: An improved scanning grating useful as an image scanner and spatial frequency filter, for a focusing detector to ascertain the focus of an optical system on deflecting the light incident from the optical system into two different directions for forming two images of the exit pupil or of parts thereof of said optical system. A slit grating is superimposed over the groove grating so that the ledges cover the peaks and the troughs thereof. It is thereby attained that the signals obtained from the peak and trough areas, which normally are more or less undefined, are exempt from evaluation. The ledges have a width ranging from 10 to 100 percent of that of the slit width.

Abstract: System for measuring the relative position and/or velocity of two objects with respect to each other and/or with respect to a common reference system, such as the ground, according to the magnitude and direction thereof, using electro-optical measuring means, the improvement comprising:(1) producing images of the object to be measured in at least two different spatial positions;(2) producing A.C. electrical signals of different frequency proportional to the relative movements of these images to at least one optical correlation system; and(3) evaluating these signals, with the use of the trigonometrical relationships of the perspective imaging, in a computer to determine the measured values.

Abstract: Slide projectors with automatic focusing systems consisting of a scanning auxiliary projecting system and a position control focusing the slide and comprising a light sensor detecting the reflections from the slide are improved by mounting the light sensor outside the scattered light zone generated when the main projection beam passes through the slide. The light source of the auxiliary projecting system is operated at less than rated voltage and silicon cells are used as light detectors. The light course comprises a lens which is mounted in the same manner as the light sensor on holders and the holders are pivotably supported for the purpose of adjustments.

Abstract: A method for separately evaluating the contents of an image in two coordinate directions of motion by splitting and then reflecting the received image so that the images may be separately analyzed.An apparatus for performing the method which comprises a beam splitter, a reflector and a correlating grid.A method of measuring distance by using the apparatus of the invention is also disclosed.

Abstract: A mirror reflex camera having a pentaprism and an electronic rangefinder is improved by displacing the viewer axis by an angle up to 5.degree. downward with respect to the optical axis of the picture taking lens. This is accomplished by modifying the pentaprism to have a fully specular concave mirror (7b) at the lower edge of the exit surface of pentaprism (7) and by selecting the angular dimensions of the pentaprism (7) so that the viewer axis (8a) deviates by an angle beta up to 5.degree. downward with respect to the optical axis (8) which is horizontal in the ordinary operational position of the camera, and by having ocular (6) offset upward and so slanted with respect to its position when the optic axis (8) is horizontal that the ocular axis (6a) subtends an angle alpha up to 5.degree. with the optic axis (8).

Abstract: Disclosed is a two-coordinate measuring device for use in the measuring ocular of a microscopic measuring instrument, comprising at least one reference mark carrier movably mounted in an intermediate image plane of the instrument and having a direction of movement which forms an angle of 45.degree. with axes in the x- and y-direction defined by the object, and means mounted in the measuring ocular for adjusting the position of the mark carrier in order to align the reference mark with the dimensions of an object which is to be measured. The reference mark of the carrier preferably comprises two perpendicular lines which are arranged on the carrier such that the bisector of the angle formed by the lines coincides with the direction of movement of the carrier. Also disclosed is a process for use of this device.

Abstract: Disclosed is a drawing pencil having a magnetic coil scanning element thereon for use with an optical analytic apparatus which scans a grid plate drawing table and converts an image thereon into an electrical signal. The magnetic coil scanning element is juxtaposed to the writing tip of the pencil such that its axis is inclined with respect to the axis of the drawing pencil, preferably such that in the normal writing position of the pencil the axis of the magnetic coil scanning element can be aligned perpendicularly to the surface of a drawing table.

Abstract: Illumination system for photographic enlargers having a chamber mounted between the lamp and the negative aperture and consisting of heat-insulating, non-staining material of high light reflective and scattering power. In addition to the light entry and exit apertures, a further opening has a wall-segment inserted therein for cooling the mixing chamber and this wall segment consists of a material having a greater heat conductivity than the polyalkene foam.

Abstract: In an interchangeable lens assembly for single lens reflex cameras the f-stop preselection ring is provided with a first transmission element for transmitting the preselected f-stop value into the light metering instrument of the camera housing, and with a second transmission element for controlling a device in the camera housing which indicates the preselected f-stop value. Said first and second transmission elements are parts of one common setting member which is in such a manner fixedly mounted on the preselection ring that -- when the preselection ring is in its base position -- said first transmission element assumes the same position in all interchangeable lenses while said second transmission element assumes positions that vary according to the maximum opening of the lens.

Abstract: An optical system for the metering of illumination in photographic cameras, in particular mirror-reflex cameras, which makes use of a photodetector with a light-sensitive surface small in comparison to the image area to be metered and which is mounted in the lower camera space. A honeycomb mirror consisting of a multitude of convex or concave mirror elements is mounted behind the reflex-mirror which is partly transmitting. The honeycomb mirror when it is in the metering position is located in front of the film plane and is moved together with the reflex-mirror out of the way of the beam path before the picture is taken, the mirror elements of the honeycomb mirror being slanted so that the center of every individual element reflects the principal rays toward the photodetector. The curvature of the mirror elements is such that the outermost peripheral rays from the objective are reflected from the rims of the mirror elements toward the photodetector.

Abstract: A scanning accessory for a microscope/photometer, where the photometer system is mounted to or inside an intermediate tube of the microscope and the intermediate tube is provided near or at the one end of its lower side with a coupling system for mounting to the stand and at the opposite side with a coupling system for mounting the ocular, the photometer being inserted into the intermediate tube's beam by means of a beam splitter, a subsequent triple mirror and an ocular. The scanning accessory preferably periodically changes the relative position of the transmitted beam (4a) and of the image (76a) or (76b) of the measuring stop (42) with respect to the microscope image (72) and is located between the photometer system (41-46) and the beam splitter (22) mounted inside the intermediate tube (2) of the microscope for the purpose of enlarging the application possibilities of the microscope/photometer.

Abstract: Photographic camera with through the lens exposure metering where the exposure meter is equipped with a silicon- or gallium-arsenide-phosphorus-diode mounted in the space behind the objective and receiving the light. The exposure meter is switchable between integrating and selective metering mode. Two optical systems (12,13) are mounted in front of the light-sensitive diode (10) and are located in the illumination beam being measured. Either of the optical systems is selectively brought into position into the beam in front of the diode (10). One of the systems, namely (13), guides the light from almost the entire object space onto the diode (10). The other system (12) guides only light from a restricted sector of the object space onto the diode (10).

Abstract: A method of and circuit for monitoring the amplitude of a sine wave-shaped electrical signal in a defined range of a signal period, wherein the signal is derived from scanning an object which is to be measured or controlled. A comparison circuit is provided which compares the signal being monitored to a reference signal and generates a first impulse signal which is applied to a logic gate. A second impulse signal generating network generates a second impulse signal determining the range of the signal period by adding at least one signal derived from additional signals contained in the signal spectrum to the signal being monitored. This impulse is also applied to the logic circuit. The logic circuit produces a switching signal for operating an indicator or control device.

Abstract: Disclosed is a photoelectric incident light distance measuring device, comprising a light source; a reflecting scale grating; a reference grating with a lattice constant differing from that of the scale grating; the reference grating being transparent and displaceable with respect to the scale grating; an air space between the two gratings; and a plurality of photoelectric receivers placed at intervals in the direction of the distance to be measured for scanning the scale grating through the reference grating whereby vernier strips are produced, and wherein at least two of the photoelectric receivers are arranged approximately at a distance "x", measured in the direction of the light, from the grating with the larger optically effective lattice constant, wherein:x=a/vwitha=optically effective air space between the reference and scale gratings;v=d.sub.M /(y+d.sub.M)=distortion factor;y=distance of the vernier strips produced by the two gratings;and withd.sub.