Abstract: A photosensitive detector (1) for detecting luminous flashes (2) is provided with a photosensitive diode (3) which is linked to a positive voltage and to ground via a resistor R1 and which is capable of transforming the luminous flashes into electrical signals and a circuit (4) that processes the electrical signals generated by the photosensitive diode (3). The circuit (4) causes electrical signals which correspond to luminous flashes (2) received by the photosensitive diode (3) and which exhibit a fast rise time to be strengthened, and the circuit (4) causes electrical signals which correspond to luminous flashes (2) received by the photosensitive diode (3) and which vary more slowly in intensity to be attenuated. The circuit (4) is linked directly to the photosensitive diode (3) and includes a differentiator circuit.

Abstract: The present invention relates to a homing head mounted on a flying body, and intended to guide the flying body towards a target. According to the invention, the homing head includes a target detection system (SD1) comprising a system (SI1) for identifying luminous flashes originating from the target, and a target locating system (SL1), which includes a photosensitive detector (D1) mounted fixedly on the flying body and comprising a matrix of photosensitive sensors, and a means of focussing (6) which projects onto said matrix of the photosensitive detector (D1) the image of the scene situated fore of the flying body.

Abstract: The present invention relates to a system for determining the roll angle (.phi.), as well as the position with respect to an axis (OX), of a moving body (2), said system (1) having an optical detector (3). According to the invention, said system (1) includes:three optical elements (8, 9, 10) mounted on said moving body (2) and capable of generating light flashes (7), two of said elements (8, 9) being mounted so as to be diametrically opposed and the third element (10) being arranged so as to be perpendicular to these two elements; anda computer (4) determining the position and roll angle of the moving body (2) from the position of said optical elements in a picture.

Abstract: A device intended to be associated, on the one hand, with a viewfinder, on the eyepiece side thereof, and, on the other hand, with a calculating mechanism, to form a system making it possible to determine at every instant that portion of a field sighted by the eye of an observer through the viewfinder. The device is arranged on the image side of the eyepiece of the viewfinder and includes a splitter element associated with a thick optical plate whose parallel faces are orthogonal to the optical axis of the finder.

Abstract: The present invention relates to a photosensitive element (1) for detecting flashes of light (2).According to the invention, said photosensitive element (1) includes a control device (4) knowing the instant of the emission of the flashes of light (2) and capable of switching said photosensitive element into one or the other of two different states:a positive accumulation state in which the accumulation capacitor (12) is charged by the light energy from said photosensitive element (1); anda negative accumulation state in which the accumulation capacitor (12) is discharged by the light energy from said photosensitive element (1).

Abstract: Device intended to determine the portion of a field seen by the eye (5) of an observer.According to the invention, this device includes:an optical sighting system (2, 3) through which said eye (5) looks at said field, said optical system comprising an exit eyepiece (15) behind which said eye (5) is placed; anda first optical component (22) placed on the side of the object focal plane of said exit eyepiece (15), said first optical component letting through the light rays (16) which come from said field and which pass through said optical sighting system and sending to said eye (5) a light beam (24) emitted by a light source (23) in order to form at least one reflection.

Abstract: A process and apparatus are provided for estimating the movement of a moving object relative to a reference object. A symbol is formed on the moving object, the symbol having a rectilinear contour with at least two parallel straight lines. The symbol is observed from the reference object and the movement is determined by means of successive projections along two axes having a relative rotary movement with respect to the recorded image of the symbol. The rotary motion is preferably at such a rate that it does not interfere with obtaining images of the straight lines.

Abstract: This invention relates to an electro-optical pickup of the type incorporating a charge coupled device. The invention has a sequencer that controls the successive acquisition by the photosensitive zone of a plurality n of images. The sequencer transfers into the intermediate memory zone, after formation of each of the images, a part of this image constituted by a number of lines m less than or at the most equal to the ratio M/n between the number M of lines of the intermediate memory zone and the number n of the images. The sequencer accumulates the partial images in the intermediate memory zone. The sequencer controls, via the readout register, the complete transfer of the partial images from the intermediate memory zone into the outside memory means, as well as the distribution of the partial images in the outside memory means.

Abstract: This invention relates to a system for locating a body in motion with respect to an axis, comprising an optical detector disposed in fixed manner and cooperating with an optical emitter connected to said body in motion, system wherein said optical detector comprises a fixed matrix of controllable photosensitive elements; said optical emitter produces flash signals; and synchronization means are provided for said electronic control means to deliver control pulses synchronized with said flash signals and triggering off the taking of an image. The invention is more particularly applicable to the location and guiding of missiles.

Abstract: Tape drive apparatus having a drive roller 1 and pinch roller 2 including a idler roller 3 around which tape 4 passes. The pinch roller 2 which is rotatable about two normal axes (A2 and A4), is resiliently urged against the drive roller 1 and the idler roller 3, the two rollers being spaced apart from each other. This apparatus is particularly useful for magnetic tape cassettes, the pinch roller 2 being formed as either part of the cassette or as part of a tape recorder/player for using a cassette.

Abstract: In a magnetic tape cassette having an elastic belt for maintaining the tension of the tape, a second, curved roller is provided between the belt and the floating roller which presses the belt against the tape reels. The two rollers are mounted on a common semi-restrained slidable support plate. The pressure exerted on the second curved roller is transferred to the floating roller by the plate, while the second curved roller, which is biconical, maintains the height of the belt even when the tape is repeatedly wound and rewound over a short section of its length.

Abstract: In a tape transport apparatus comprising notably a floating roller (12) tangent to reels (5, 6), and an elastic endless belt (11) extending between the floating roller (12) and the reels (5, 6) to form a first loop (11a) surrounding the floating roller (12) and a second loop (11b) engaging on an arc of the periphery of each of the reels (5, 6) to maintain the tension of the accessible portion of the tape (7), this second loop (11b) extending around at least one return roller (13, 14), the invention provides that at least return roller (14) is directly driven by drive means (18, 19), whereby the peripheral speed of the driven return roller (14) and the peripheral speed of the floating roller (12) are maintained in a ratio slightly greater than 1, so as to ensure better tensioning of the tape on the take-up reel.

Abstract: Chloroprene is polymerized in an alkaline aqueous emulsion, containing a sulfonamide. The presence of the sulfonamide provides polychloroprene latices which are stabilized against aging.

Abstract: Sulfur-modified polychloroprene in alkaline aqueous emulsion is prepared by incorporating one or more organic polysulfides which act as peptizing agents during the polymerization of the chloroprene. The sulfur-modified polychloroprenes obtained have stable viscosities.

Abstract: Homogeneous free-running powders, mixable when dry and with a mean particle size of between 0.1 and 5 mm, are obtained by high-temperature flocculation in the presence of aluminum polyhydroxychloride salts. The temperature is preferably between 70.degree. and 100.degree. C. and the pH is preferably 6 to 13.

Abstract: Polymerization of chloroprene in an alkaline aqueous emulsion provides an improved latex by adding a specific amide to the emulsion, the amide being insoluble in water, soluble in the chloroprene and not being hydrolyzed by NaOH. The presence of an amide of this type makes it possible to obtain polychloroprene latices stabilized against ageing.

Abstract: Sulfur-modified polychloroprene in alkaline aqueous emulsion is prepared by incorporating one or more organic polysulfides which act as peptizing agents during the polymerization of the chloroprene. The sulfur-modified polychloroprenes obtained have stable viscosities.