Optical disc of write once type, method, and apparatus for managing defect information on the optical disc

An apparatus for managing an optical recording medium having at least one defective area in a user data area, comprising:

• an optical pickup;
• and
• a controller configured to control the optical pickup to
• record a defect management information unit having at least one recording unit, and manage the at least one defective area in a defect management area of the recording medium with the defect management information unit,
• wherein the defect management information unit includes a defect list part and a position information part, the defect list part including one or more defect entries and occupying a front portion of the defect management information unit, the position information part including a defect list pointer indicating a start position of each of the at least one recording unit of the defect management information unit and occupying an end portion of the defect management information unit.

A computer readable optical recording medium, comprising:

• a user data area within a data area;
• and
• a defect management area for recording defect management information unit for managing replacement data of at least one defective area within the user data area of the recording medium,
• wherein the defect management information unit includes a defect list part and a position information part, the defect list part including one or more defect entries and occupying a front portion of the defect management information unit, the position information part including a defect list pointer indicating a start position of each of the at least one recording unit of the defect management information unit and occupying an end portion of the defect management information unit.