A screen adjustment device (1) for a motor vehicle has a screen (6) or screen carrier (2) for mounting a screen, and a control cable drive (4) for adjusting the screen or screen carrier between an open (screen-accessible) position (22) and a parked (screen-hidden) position (24). The control cable drive has a control cable (11), which is coupled to the screen or screen carrier by a driver (15) and which at the two ends is guided over two return elements (12, 13) and at least one cable tensioning unit (18, 19) onto a winding reel (14) coupled to a drive motor (21). The control cable drive has a bearing block (30) for supporting the winding reel, the block together with the cable tensioning unit forming a self-contained pre-assembled unit (20) or being capable of pre-assembly to form such a unit.