Abstract: An optical unit for optically scanning a surface, particularly an information surface of a recording medium. The unit may include a frame, a radiation source unit, a rotatable mirror unit, and an objective system for forming a scanning spot on the information surface. The objective system has an entrance pupil and an optical axis. From an optical point of view, the rotatable mirror unit is situated between the radiation source unit and the objective system, suspension means being provided for movably supporting the objective system relative to the frame. The suspension means allow a longitudinal movement of the objective system along the optical axis and a pivotal movement of the objective system about a pivot which coincides with the point of intersection of the optical axis and the entrance pupil. Actuating means drive the objective system in accordance with these movements. Alternatively, the optical unit may include an optical beam deflection unit.