Abstract: The invention relates to an optical data system comprising an optical disc drive and a host. The optical disc drive is arranged to receive an optical disc and perform read and write actions with respect to the optical disc. The host is arranged to instruct the optical disc drive to perform a read or write action with respect to the optical disc. The optical disc drive may be arranged to a) the optical disc drive is arranged to perform a quality measurement generating a plurality of quality parameters, b) the optical disc drive is arranged to output the plurality of quality parameters to the host, and c) the host is arranged to decide on a further action based on the received plurality of quality parameters.

Abstract: Apparatus and method for discriminating in an optical drive between discs of different formats, in which the optical disc remains substantially stationary or is arranged to rotate at a very low frequency i.e. significantly lower than that required to perform a data readout or record action for the purpose of measuring the reflectivity thereof by ramping, i.e. moving, the actuator toward the optical disc (step 106a) and, during this ramp, observing (step 106b) the total reflection, known as the Central Aperture (CA), off the disc. After scaling of the reflectivity (at step 108), the system tries to catch focus (step 110) i.e. close the focus servo loop). If, at step (112), the measured reflectivity is far out of range, or the focus catch fails, then the sequence is repeated for the next laser, until the disc format has been accurately determined.