An optical disc device records data on an optical disc by projecting a laser
beam
on the optical disc such that a linear density of the data becomes substantially
constant. The optical disc device comprises velocity judging means, velocity changing
means, recording velocity detecting means, and recording velocity transmitting
means. The velocity judging means is for judging a recordable velocity for an optical
recording medium inserted into the optical disc device. The velocity changing means
is for changing a recording velocity designated from a host. The recording velocity
detecting means is for detecting the recording velocity during a recording. The
recording velocity transmitting means is for transmitting information concerning
the detected recording velocity to the host.