Roller blind for a sliding roof system

The roller blind (10) has a flexible material (13) that partially covers a roof opening, and two coil springs (24), which extend in longitudinal direction (11) of the roller blind. A spring-loaded winding shaft (26) is provided, which extends transversely to the longitudinal direction continuously from a longitudinal edge (16) of flexible material to an opposite longitudinal edge. The spring-loaded winding shaft is firmly connected with a transverse edge (28) of the flexible material.