On 0-1 Learning

An optical focussing device for focussing a radiation beam emanating from a radiation source onto a record carrier (1), and more specifically for focussing a light beam onto a video disc or audio disc, comprises a frame (3) in which an objective (10) is movable axially in the direction of its optical axis (15) with the aid of a drive system (4-7, 16). In order to avoid damaging of the record carrier (1) at last one elastic bumper (37) is secured to the free end (11) of the objective (10), which bumper absorbs shocks and prevents marring of the record carrier in the event of contact between the objective and the record carrier.