Patent ID: 8094530

Claim:
An optical disc read/write apparatus that performs an alternative write by using an alternative area on an optical disc which includes a plurality of alternative blocks, each of the alternative blocks including a plurality of alternative sectors, if a defect is detected in a write area of the optical disc when an attempt is made to write user data on the optical disc in the unit of a sector, the optical disc read/write apparatus comprising: a spindle motor that rotates the optical disc; a pickup that irradiates the optical disc with laser light to read/write data; a read/write circuit that processes read and write signals for the pickup; a servo circuit that controls the rotation of the spindle motor and the movement of the pickup; and a microprocessor that controls a data read/write process and an alternative write process in the unit of a sector via the read/write circuit and the servo circuit, wherein the microprocessor is configured to: check whether a block containing a write sector can be normally read; determine, if the block is not successfully read, that the read block is a defective area, and performs an alternative write in the alternative area in the unit of a sector; when new data is to be written in a new alternative sector in a situation where user data written in a plurality of alternative sectors corresponding to the same block in the write area are dispersed in different alternative blocks as a result of the alternative write, acquire user data that are dispersed in different alternative blocks; and merge acquired data of the other sectors with the new data and rewrite merged data in the same block.