Thomson-csf

Yves Cojan

Georges Couderc

Robert Pressiat

Bernard Guerin

Denis Bargues

Jean-Louis Beck

R&eacute;my Fertala

Gilbert Coateval

Method and system for protecting optoelectronic search and tracking equipment from an illumination

The system allows homing on a useful target to be obtained in the presence of considerable parasite sources, such as the sun, in the field of observation. It includes elements for the spatial and spectral discrimination of the infrared light sources, formed with a detector strip preceded by a fixed modulation grid, the uniaxial field scanning device, switchable electronic filtering, one band pass and the other low pass, and switching optical filtering, one with very narrow band and the other with wide band. The grid is preferably formed by herringbone patterned tracks. The narrow band filter may be centered towards 4.4 microns and the wide band filter covers 3 to 5 microns for providing homing of a missile by optical deviation heading measurement in a ground/air or sea/air defense system.

Optronic heading deviation measurement system providing spatial and

An airborne system for the electrooptical detection, location and omnidirectional tracking of a target has an input objective lens carried by a universal joint, whereof one frame is rotated circularly in azimuth and the second frame moves the optic in elevation. An image offsetting optical section integral with the universal joint maintains the image centering through the detection plane, the detector being fixed. The image offsetting optical section is catadioptric and has an input mirror integral with the objective lens, and an output mirror integral with the first frame and which reflects the radiation along the circular rotation axis. The input objective lens focuses the radiation in an image plane located on the optical path between two mirrors, and a second optical objective lens, re-forms the field image in the detection plane.

Airborne system for the electrooptical detection, location and

A direction finder including downstream the reticle an intermediate objective and a four quadrant detector, the reticle providing a modulation at a given frequency and in which the intermediate objective comprises preferably a half-ball lens whose center of curvature coincides substantially with the detector center to allow a relative movement of the reticle with respect to the detector, such as a rotation round this center controlled by a driving device.

Photoelectric direction finder

A photoelectric direction finder in which the modulating and spatial filtering functions produced by the reticles are separated from the deviation measurement function resulting from a four quadrant detection, provided with a view to permitting a passive or semi-active bimodal operation. The reticles are determined transparent for the radiation emmited by an auxiliary laser illuminator modulated according to a modulation different from that provided by the reticles in the passive mode, while the processing and deviation measurement circuits have additional laser signal demodulation circuits and automatic or priority mode selection and switching circuits.

A display instrument using optical collimation for projecting data into the line of sight of an observer, comprising an optical lens which projects images of luminous objects focused at infinity onto a transparent combining glass. The projected images of the luminous objects corresponding to data are reflected by the glass into the observer's line of sight. A semi-transparent optical mirror is arranged parallel to the glass at a greater distance from the optical lens, to provide an enlargement in elevation of the original pupil as defined by the outline of the image of the lens through the glass.

Display instrument using optical collimation

A display collimator system comprising a cathode-ray tube for displaying electronically generated data and a standby reticle arrangement to be operated in case of failure of the tube. The standby reticle arrangement comprises at least a movable reticle produced statically by means of a plurality of n elements juxtaposed according the intended direction of shift, each element comprising a light source to represent, when supplied, a one and same common shape, and a supply control circuit having n switching positions to supply the n elements separately.

Display collimator system including a standby reticle arrangement

A display instrument using optical collimation for projecting data into the line of sight of an observer, comprising an optical lens which projects images of luminous objects focused at infinity onto a transparent combining glass. The luminous objects corresponding to data be displayed are positioned in the focal zone of the lens. The images are reflected by the glass into the observer's line of sight. A reflective optical element is arranged parallel to the glass, in the space contained between the optical lens and the field of vision of the observer, to provide an additional optical pupil which forms in conjunction with the original pupil of the instrument an enlarged pupil.

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Paris, France

Yves Cojan