Patent ID: 7466483

Claim:
A masking device for a cinema screen comprising: at least two masks disposed in front of said screen, and placed in pairs symmetrically along at least two sides, left and right and/or top and bottom, of the screen, each mask comprising a rolling shaft and a cloth rolled up around said shaft, each rolling shaft protruding either side of the cloth and each cloth comprising a rolled edge and a free edge, wherein at least the lower mask and/or the pair of left and right masks comprise(s): a tensioner for holding the free edge of the cloth of each mask, a length of the tensioner being greater than a length of the cloth, and means of controlling a positioning of the tensioner in a plane substantially parallel to a plane of the screen and in a direction perpendicular to an unrolling direction of the cloth, said means comprising, on the one hand, ropes each attached to one end of the tensioner protruding from the cloth and each connecting, in a direction substantially parallel to the unrolling direction of the cloth, said ends to the rolling shaft of the mask to which said tensioner is attached by means of angle transmission pulleys each placed facing a corresponding protruding end and at a distance from the rolling shaft, and, on the other hand, means of rotating the rolling shaft, so that each cloth can be unrolled from its shaft toward a center of the screen to adapt the masking area of said mask.