Abstract: An optical device for measuring the angular position of electromagnetic radiation, such as laser light, incident on the device, includes a lens system defining an input surface for receiving the incident electromagnetic radiation and an output surface towards which the incident radiation within the optical field of vision of the device is deflected by the lens system, a plurality of light guides each having a first end facing and in direct physical and optical contact with the output surface of the lens system, the first ends of the light guides substantially covering the output surface of the lens system, a detector allocated to each respective light guide and connected to its second end, and a calculating unit for determining a present angular position, based on the signal values outputted by the detectors, by calculating ratio between difference signals and sum signals of signal values of the detectors and determining the angular position corresponding to this ratio.

Abstract: A primary mirror and a secondary mirror are arranged on a lens to form an eccentric radiation path through the mirror objective. The optical axis of the mirror objective follows an N-shaped path through the objective and central diaphragming is avoided. The object and consequently the image are situated outside the geometrical axis of the mirror objective, which shows a short distance between the object and the image. In an optical arrangement comprising two such mirror objectives, one is used for illuminating and the other is used for imaging.

Abstract: The present invention relates to an image-forming objective which is capable of forming sharp images of objects at at least two different distances from the objective, there being arranged at one focal plane of the objective a corrective element divided into at least two fields in which the refractive power differs between them.

Abstract: A night vision instrument with an electronic image converter, comprising for example an image intensifier tube or a similar device. This night vision instrument (FIG. 3) may be located beside an ordinary telescope, sight, TV-camera or similar device (6) so that this same device may be used during night time. The combined system (FIG. 3) thus arranged is very compact, with the center of gravity close to the user during handheld operation. The lightgathering objective lens consists moreover of only one mirror (1) and the image emerging on the screen (3) of the electronic image converter is facing the corresponding object being viewed. The image on the screen (3) is finally collimated so that it may pass into the entrance aperture of some other instrument (6) in parallel, and this image transfer is accomplished with three reflections or less and without any intermediate real image.

Abstract: This invention relates to a device for use when evaluating optical signals by means of a chopper (2, 2'), i.e. a rotating shutter, and a photodetector (6, 6') for detecting the signal transmitted through the chopper (2, 2'). In order to improve the evaluation of the incident signal the opaque part (3, 3') of the chopper is provided with a reflective surface (7) to utilize also the optical signal falling on the opaque part (3, 3'). An additional photodetector (9, 9') has been arranged for detecting this reflected optical signal. In order to reduce the energy losses and in this way increase the amplification of the optical signal the device also comprises an optical element in the form of a glass prism (10, 10') in which one and the same surface is utilized both for transmitting and reflecting the optical signal.

Abstract: The invention relates to a binocular night telescope of the type which comprises a large aperture objective (1), a light amplifier tube (2) for amplifying the image projected by said large aperture objective and a viewing microscope which comprises telescope objectives (9, 10) and oculars (11, 12) as well as a collimating objective (6) for focusing the amplified image at infinity for an observer. The viewing microscope also comprises prisms or mirrors for erecting the image vertically as well as in side. At least a part of the prisms (7, 8) for erecting the image in side are axially displaced so that they are located at the side of, above or below the light amplifier tube (2) depending on the orientation of the microscope. This means that the entire instrument is shorter and the center of gravity is moved forwards.

Abstract: A symbol plate for an artillery collimator and an artillery gun sight has a vertical center line across the plate and symbols arranged in a row symmetrically in relation to the center line. The symbols are formed of digits which are arranged to indicate numeral values proportionally variable with the distance to the center line, the digits being arranged with opposite inclination on opposite sides of the center line.