Thomson-csf

Michel Favreau

Jean Bajon

Serge Soca

Claude Puech

Luigi d'Auria

Jean Pierre Huignard

Jean Pierre Lacotte

Serge Vidal

Michel Cattoen

Guy Chevalier

Andre Marguinaud

Christian Delattre

Maurice Longuet

In an embodiment, the device comprises ten rows of ten cathode-ray tubes, each tube being associated with a convergent lens. Each cathode-ray tube reproduces a picture portion and the lens enlarges this picture portion in such a ratio that the joints between the cathode-ray tubes no longer appear. The cathode-ray tubes incorporate a single electron gun, two pairs of electrostatic deflection plates and a screen incorporating red, green and blue phosphors abnd ultraviolet indexing phosphors. The display device is connected to an electronic device which supplies scan signals for each cathode-ray tube and which supplies color signals. The horizontal-scan frequency and vertical-scan frequency are ten times higher than for a conventional television display. The electronic device possesses memories which store the color information corresponding to each of the picture portions.

Large screen video display comprising a matrix array of cathode-ray

The correction consists in correcting the overall luminance, while retaining the original chromaticity of the analyzed picture. For this purpose, the device according to the invention comprises a correcting circuit receiving the color signals V.sub.e1, V.sub.e2 and V.sub.e3 and supplying corrected color signals, a matrixing circuit supplying the overall luminance signal V.sub.e, and a control circuit calculating eight transfer parameters defining the transfer function F, which transforms the signal V.sub.e into a signal F(V.sub.e) covering the scale of luminances in accordance with an equal distribution in order to satisfy the optimum vision conditions. The control circuit processes the signal (F(V.sub.e)/V.sub.e) and the correcting circuit supplies corrected color signals respectively corresponding to the products V.sub.e1 .multidot.(F(V.sub.e)/V.sub.e), V.sub.e2 .multidot.(F(V.sub.e)/V.sub.e) and V.sub.e3 .multidot.(F(V.sub.e)/V.sub.e).

Device for correcting color information supplied by a television camera

The demodulator combines a conventional frequency discriminator with a bandpass filter for removing the noise which is present from the band occupied at a given instant by the modulated signal. The center frequency of the bandpass filter is controlled in dependence on the instantaneous frequency of the modulated signal and its bandwidth b.sub.u is controlled in dependence on the instantaneous width of the band occupied by the modulated signal.

FM Demodulator with variable bandpass filter

The present invention relates to a television system using a pickup tube performing an oscillatory scan. On reception the picture restoration device uses a receiving tube which performs a linear restoration, but with a line frequency which is double the scan frequency. In addition, the signal supplied for the pickup tube is processed on reception by two separate processing channels. The two channels respectively supply first and second signals respectively corresponding to the low part and the high part of the receiving tube input signal spectrum. This input signal is then reconstituted by means of an analog mixer. This leads to a much better definition than that obtained with existing television systems.

High definition television system

The device comprises a variable-characteristic nonlinear four-terminal network having one input for receiving a video signal V.sub.e and eight inputs for controlling transfer parameters. Statistical analysis of the amplitude of the signal V.sub.e permits acquisition of the luminance distribution function of said signal. On the basis of this distribution function, computing means determine the values of the transfer parameters to be applied to the control inputs of the four-terminal network in order to deliver at the output of the network a video signal V.sub.s which extends over the entire luminance scale and has the desired distribution for satisfying optimum conditions of vision.

Device for automatically controlling the transfer function of a video

The present invention relates to an apparatus for the digitization of videofrequency television signals making it possible to improve the subjective definition of known systems using a non-orthogonal structure of points and to obviate the disadvantages of said system structure. This apparatus comprises on reception an analog-digital converter by high speed sampling corresponding to the full definition of the processed spectrum followed by an inhibitor of one sample out of every two and on reception, a conventional decoder, whose analog output signal is added to the other part of the spectrum resulting from a logic processing of the original binary train or stream.

Apparatus for the digitization of videofrequency television signals

In a telecine equipment of the flying spot cathode-ray tube type with an oscillatory mirror, markers associated with the frames of a film are illuminated with a light spot of small dimensions, which substantially follows the motion of the marker associated with the frame being scanned. This is obtained by means of a small fixed light source, which is used for scanning the path followed by the marker associated with the film frame being scanned, using the same optical channel as for the frame scanning. This same optical channel, used in the reverse direction by means of a fixed mirror located behind the film, forms the image of the illuminated marker.

Arrangement for projecting images of markers on to a photosensitive

In the luminance signal channel, the notch filter 40 which considerably attenuates the subcarrier is a variable filter whose tuning is controlled by a signal which is a function of the instantaneous frequency of the subcarrier.

Secam color television receivers employing tunable notch filter in

The top part of the band occupied by the complete video signal is split into two adjacent channels I and II respectively utilized for the alternate transmission of the first subcarrier S.sub.B and the second subcarrier S.sub. R, the luminance signal components being eliminated from the channel utilized for the particular subcarrier which is in the course of transmission. On reception, that part of the luminance signal, Y.sub.h1 or Y.sub.h2, transmitted through said top part, is repeated in the same delay line as the subcarriers.

Transmitter and receiver circuits for the sequential storage color

A cinematographic film to be reproduced by television is driven at constant speed in synchronism with the sweep cycle of one or more camera tubes each positioned to pick up images projected upon a receiving surface thereof whose luminous persistence equals at least a sweep cycle. The film is periodically transluminated, during the retrace phase of the scanning beam, by a light pulse emitted by an electroluminescent diode -- or by a cluster of such diodes operating on different wavelengths -- defining a quasi-pinpoint light source, the diode being excited by an energizing pulse whose length does not exceed the duration of a line scan of the camera tube.

Growing community of inventors

Paris, France

Michel Favreau