Abstract: An infrared thermographic optical scanner is comprised of a first optomechanical device fitted with an entrance objective, at least a raster scan element, and a plane of infrared detectors on which the infrared radiation is focused in the form of lines. Further, there is provided a second optomechanical device made up of an orientable tilted periscope-head mirror and a derotator. The derotator is maintained clamped with respect to the head mirror coupling means for operation in the panoramic mode in a predetermined first angular position such that all lines scanned are parallel to each other, the raster scanning movement being obtained by maintaining the position of the raster element fixed, and by simultaneously causing the rotation of the head mirror, and at half-speed, causing the rotation of the derotator.

Abstract: Opto-mechanical analyzer using a single polygon (P) comprising n reflective faces which are arranged parallel to the axis (2) of the cylinder in which the polygon is cut and are determined in such a way that their distribution on the periphery is sinusoidal. The polygon rotates about an axis (1) extending at an angle .theta. to the axis (2) and situated in the plane formed by the axis (2) and the axis (X X') on which the diameter of the cylinder extends. On either side of this diameter the reflective faces have been distributed pairwise parallel. The n faces of the polygon thus have n different inclinations with respect to the axis of rotation and the angular pitch is constant.

Abstract: Device for correcting the differential distortion resulting from simultaneous observation of a field of view at two distinct locations through a shield transparent in a given spectral band, which shield has a shape generating the distortion when a receiver which is sensitive in the spectral band is arranged at each of the locations. The correction is effected by an optical system arranged between the shield and one or the other receiver and comprising an anamorphic assembly (11, 12) producing an anamorphosis in a first direction associated with an element (13) introducing a curvature in a second direction, while the distortion produced by this system has a direction opposite to the differential distortion.

Abstract: Optical axes of the day path and of the night path extend in a sagittal plane (5,9) of the carrying vehicle and the passage from the night path to the day path or conversely is effected by means for displacing a first reflector parallel to the plane in order that the input light beams are directed to the optical axis of the day path or of the night path. A second output reflector along the optical axis for the day path is simultaneously displaced from an active position, for viewing by day, to a concealed position, for viewing by night, when said first reflector is displaced to deflect said beams along said night path.

Abstract: Device for stabilizing the axis (11) of a variable field guidance system with respect to the axis (2) of a sighting device (1) in which the sight axis (2) is adjusted until it is perpendicular to a plane-parallel plate (3) forming an optical reference element. An angular movement of the guidance axis (11) is registered by an error measuring device having an aperture (13) which is arranged symmetrically to the optical center (9) of the guidance system with respect to a further plane-parallel plate (15) and a detector (14) which receives the flux from the guidance beam transmitter after successive reflections from the plane-parallel plates (3 and 15). The detector (14) is connected to the input of an error measuring receiver (16) which supplies an error signal which is applied to a correction element (17) in the guidance beam path.

Abstract: The apparatus contained in a single housing (1) comprises a first movable input reflector (4) and a second input reflector (5) for causing the input light beams to deviate along the optical axis (11) of the night path and optical axis (7) of the day path, respectively. The night path is constituted by an objective (12), a light intensifier tube (13) and a bent ocular (14) and the day path is constituted by an optical system having a second output reflector (9). The optical axes of the night path and of the day path extend in a sagittal plane (7, 11) of the carrying vehicle; on the other hand, the first input reflector and the second output reflector are alternately concealable by manipulation of the second output reflector. For viewing by night the first input reflector in the active position is situated before the second input reflector, the second output reflector being in the concealed position.

Abstract: In an opto-mechanical scanner with associated scanning and ranging functions the scanning beam, obtained by line-scanning means and frame-scanning means, and the ranging beam converge on a scanning detector array and on a ranging detector, respectively. According the invention, the scanning and ranging beams traverse an arrangement of fixed optical elements which are arranged to ensure that the beams follow two different optical paths in such a way that the ranging beam traverses the line-scanning means two times. This ensures that the ranging beam has a fixed orientation which is independent of the line-scanning means.

Abstract: In an opto-mechanical scanner combining scanning and ranging functions the scanning beam, obtained from line-scanning means and frame-scanning means, and the ranging beam converge on a scanning detector array and a ranging detector, respectively. In accordance with the invention, the scanning beams and the ranging beams traverse an arrangement of fixed optical elements which are arranged to ensure that the beam each follow two different optical paths such that the ranging beam bypasses the line-scanning means. This ensures that the ranging beam has a fixed spatial orientation which is independent of the line-scanning means.

Abstract: An optical and mechanical scanner including a device for scanning a field of vision to detect and recognize with high resolution distant objects in the field of vision. Scanning is accomplished in two directions including a direction x for line scanning and a direction y for raster or image scanning. One embodiment of the scanning device includes, in order along the direction of a path of a mean incident beam from the field of vision, an objective, a raster scanning mirror for scanning in the y direction, a field mirror which delimits the field of the objective in the x direction, a rotating drum and an image transport system for line scanning in the x direction, the field mirror deflecting the beams towards the drum, and a detector sensitive to the radiation contained in the beams, the scanning device ensuring convergence of the beams at the detector.

Abstract: A wide-field binocular eyepiece preferably for use with a flat image display system. The eyepiece includes a biconvex thick lens having concentric spherical lens surfaces whose radii are selected to satisfy the aplanatic condition. To minimize chromatic aberration, the biconvex thick lens may be formed of a plurality of cemented elements having indices which are close to each other but having respective different dispersions.

Abstract: The invention relates to a device for optically scanning a field of vision divided into different regions and for displaying the field, scanning being done in two perpendicular directions, i.e. "line" scanning in a direction x and "raster" or "image" scanning in a direction y, the device scanning along beams coming from different regions of the field and causing the beams to converge on to an element sensitive to the radiation in the beams, the present invention being concerned particularly with the line-scanning means, which is designed so that the device can operate with smaller apertures without affecting its resolution. The line-scanning system comprises a rotating drum having reflecting surfaces but the detector image is conveyed outside the drum axis.

Abstract: A semiactive night viewing system utilizing light intensification forms an image of a scene on an intensifier tube by using an objective lens. The intensified image is picked up by a television camera and is displayed by a display apparatus. The display is observed through an eyepiece. If an observer wishes to identify a target, he switches over to semiative operation by producing a flash of light having a wavelength outside the visible spectrum, having a very short duration, and having lower power. The flash illuminates the central area of the field. At the same time, an image storage device stores the image signal. Subsequently, the image is read out and displayed.

Abstract: The invention relates to a dual magnification telescope such as, for example, an intensifier telescope. Telescope compriser an objective, an intensifier tube with an optical fiber input, and an eyepiece. According to the invention, the dual magnification is obtained by an optical fiber array comprising straight fiber having unity magnification and tapered fibers having a magnification G<1.

Abstract: A collimator for coordinating two optical devices which operate in different wavelength. The collimator regions comprises a source hole formed in a plane mirror. The source hole is illuminated by a source which emits light in two wavelength regions. The source is arranged in the focus of a mirror collimator. The beam which emerges from the collimator after reflection from the mirror forms a first parallel radiation beam having wavelengths in one of the wavelength regions. After passing through a plate with substantially parallel surfaces and a wedge compensator, the beam forms a second parallel radiation beam having wavelengths in the other region. The beams have the same axial spacing as the two optical devices and are made exactly parallel to each other by the wedge compensator.

Abstract: An optical system comprises a number of optical elements arranged in a housing. The housing may be fixed to the underside of an airship. The system corrects for picture tilt. The housing comprises a first fixed portion, a second portion rotatable relative to the first portion around an axis XX', and a third portion rotatable relative to the second portion around an axis YY' orthogonal to XX'. The combination of the rotating motions of the portions B and C of the housing render it possible to rotate the line of sight of the optical system through more than one half-circle.

Abstract: A device for projecting the image of a reticle in an optical system whose line of sight is represented by the reticle. The collimator is situated at the edge of the pupil of an objective of the optical system. The optical axes of the objective coincides with the line of sight. According to the invention, the collimator comprises two subcollimators arranged along respective orthogonal axes perpendicular to the optical axis. Each collimator forms an image of a radial slit in such a way that the intersection of the two slit images is situated on the line of sight. In this way, focussing error does not give rise to an angular displacement of the line of sight.