Patent ID: 7106675

Claim:
A data recorder for writing data to a recording medium, the recorder comprising: a buffer memory for temporarily storing data; an optical head for emitting a laser beam against the recording medium, wherein the laser beam has a write level and a read level, the write level being used when data read from the buffer memory is recorded on the recording medium and the read level being used when data is read from the recording medium; an interrupt control circuit for interrupting the writing of data when detecting a predetermined state; an address memory connected to the buffer memory, wherein the address memory stores at least one of an address of the recording medium and an address of the buffer memory when the writing of data to the recording medium is interrupted, each address indicating a data location where the writing interruption occurred; a synchronizing circuit for reading the data written to the recording medium prior to the writing interruption by emitting the read level laser beam against the recording medium, reading the data stored in the buffer memory, and synchronizing the written data and the stored data; and a restart circuit for restarting the writing of data to the recording medium based on the address stored in the address memory, wherein the optical head switches the laser beam emitted against the recording medium from the read level to the write level a predetermined time before the time at which the restart circuit restarts the writing of data, wherein the predetermined time corresponds to a time required to increase the level of the laser beam from the read level to the write level.