Patent ID: 8879370

Claim:
An optical disk apparatus which conducts write-once recording of data on a write-once optical disk, the optical disk apparatus comprising: an optical disk drive having a control unit configured to receive a reproduction command which specifies a reproduction area and orders reproduction, a recording command which specifies a recording area and orders recording, and transfer data; and a host having an instruction issue unit configured to issue the reproduction command and the recording command, a buffer configured to store the transfer data, and a collation unit configured to collate existing data on the optical disk with the transfer data; wherein a command for ordering reproduction is transferred from the instruction issue unit in the host to the control unit in the optical disk drive, to cause the existing data to be transferred from the control unit to the buffer in the host, and the collation unit collates the existing data with the transfer data; wherein the optical disk drive records different data in the transfer data onto a unrecorded area of the optical disk based upon the recording command from the host, the different data being different from the existing data on the optical disk; and wherein the optical disk drive records short data having a predetermined length in the transfer data, or less, onto an unrecorded area of the optical disk based upon the recording command from the host, the short data being sandwiched between the different data in the transfer data or between the different data and an end of the transfer data.