Arrangement for centering an information disc

Claim 1

An arrangement for centering, and writing and/or reading information on, interchangeable information discs comprising a carrier having a central opening defined by an inner wall, said arrangement comprising: a drive unit including a turntable rotatable about an axis of rotation, said turntable having a supporting surface on one end for an information disc, said supporting surface having a recess formed therein defined by an inner wall which is coaxial with the axis of rotation; at least one said information disc; a centering element arranged for rotation with said information disc when said disc is placed into the drive unit, said element including a central portion, elastic portions extending at least substantially radially and, near the ends of said elastic portions, transverse portions adapted for engagement both with the inner wall of the central opening of the information disc and the inner wall of the recess in the turntable, for centering the disc on the turntable upon elastic axial displacement of said central portion; and displacement means in the drive unit for axially displacing said central portion; characterized in that said carrier is substantially rigid, said inner wall of the carrier has an accurate finish, and said arrangement includes integrally constructed elastically deformable compensation means for compensating for differences in diameter between said inner walls, said elastically deformable compensating means being biased radially outwardly to exert substantially uniform pressure throughout said inner walls in response to axial displacement of said central portion, said centering element engaging at least one of said inner walls via said elastically deformable means.