Abstract: Disclosed herein is a reducible volume sun-blind with which, thanks to its simple yet functional means of adjustment, it is possible to constantly regulate the extent to which direct luminous radiation can pass therethrough. The support frame of the sun-blind is in the form of an articulated parallelogram, with a mechanism being provided to stabilize it in any one of the configurations thereof. The frame is provided with a plurality of parallel strips, elastic rods for retaining the latter under tension, a mechanism for synchronously rotating the strips, and a mechanism for stabilizing them in a plurality of positions.