Roll-up video-projection screen with a curved fabric

A roll-up video-projection screen (1) comprising a transverse upper casing (2) enclosing a horizontal rotating drum (11) around which rolls up and unrolls a projection fabric (10) provided at a bottom part with a weighting and tensioning element (30), the projection fabric having a front projection face (12), the roll-up video-projection screen further having an assembly of mechanical curving means (20) imposing, when the fabric (10) is unrolled, a transverse curvature to the front projection face (12), said imposed curvature of the front face (12) of the fabric (10) also existing in the unrolled position of use of the screen (1), wherein the curving means (20) comprise two transverse curvature profiles (21, 22) arranged in an upper casing (2), the two transverse curvature profiles (21, 22) including one upstream profile (21) located behind the front projection face (12) of the fabric (10) and one downstream profile (22) located in front of said front projection face (12) of the fabric (10), so that the curvature is imposed on the fabric (10) that is trapped between these two transverse curvature profiles (21, 22) and in that the transverse curvature profiles (21, 22) are curved backwards and arranged in relation to one another so that each point of the fabric (10), whatever its position along the downstream transverse profile (22), follows the same path of travel as the downstream profile (20) on unrolling the fabric (10), so that two points of the screen that are situated on the same transverse line of the screen in the rolled-up position thereof are on the same horizontal line in the unrolled position of said screen, wherein an axis of the upstream transverse profile (21) is located higher than a rotational axis of the rotating drum (11) and an axis of the downstream transverse profile is located lower than the rotational axis of the rotating drum (11).