Thomson-csf

Serge Vidal

Michel Favreau

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 a telecine system using a flying spot tube, the latter is used for scanning, at the same time as the film, marker zones delivering, upon being scanned, marker signals characteristic of the vertical position of the horizontal line on which they are located. The marker signals are converted into electrical signals for comparison with a reference signal; the resultant output signal is used for correcting the vertical deflection of the flying spot. The marker zones may be scanned either by an image of the flying spot distinct from that which scan the film, or by the same image.

Scanning control arrangement for a telecine system using a flying spot

In the course of each horizontal blanking interval, the spot of the flying spot tube is deflected in the vertical direction causing an image of the spot to meet a perforation of the film in fixed space relationship with the film frame being scanned. A pulse signal, generated when the image of the spot reaches the concerned perforation, is used as an input signal for the circuit delivering an error signal for controlling the vertical deflection of the tube.

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Paris, France

Serge Vidal