Patent ID: 7548498

Claim:
An optical disk unit configured to write information onto an optical disk, comprising: a storage part; a motor configured to rotate the optical disk; an optical pickup configured to write data onto the optical disk during rotation thereof by emitting light onto the optical disk; and an encoding part configured to generate and output the data to the optical pickup, the encoding part including a control part and a clock signal generator part, wherein the data is written as frames onto the optical disk, and upon detecting an abnormality during the writing of the information by the optical pickup, the control part stores identification of a current frame in the storage part and controls the optical pickup to continue writing to an end of the current frame, and when writing to the end of the current frame is completed, suspends the writing of the data by the optical pickup, and upon detecting disappearance of the abnormality, retrieves the identification of the current frame from the storage part and restarts the writing of the data at the end of the current frame as identified by the retrieved identification by joining the data so that the data are continuously readable from the optical disk at a time of reproducing the data, wherein the identification of the current frame stored in the storage part includes information indicating a number of frames written up to then, including the current frame, based on time information at that point and a subcode sync to be written, wherein the clock signal generator part is configured to generate a write-system clock signal based on a wobble signal read from the optical disk and input to the clock signal generator part through an ATIP decoder, and to output the write-system clock signal as a system clock signal inside the encoding part, wherein the motor rotates the optical disk by constant angular velocity control, the write-system clock signal follows a movement of the motor, the write-system clock signal is generated based on a wobble signal read from the optical disk, and the constant angular velocity control is performed so that a PLL is locked to the wobble signal.