Abstract: A roller blind unit in which the blind may be uncoiled from a spiral coil, the blind being made up of articulated slats and being trained along a generally level structure so that it is not acted upon by gravity to a high enough degree for operation without a power drive, has at least one flexible web-like driver element coiled up interleaved with the blind in the coil and trained at least partly around the outside of the blind coil. One end of the driver element is fixed to the take-up shaft on which the blind is coiled and the other end is anchored on a driving shaft.