Patent ID: 8164998

Claim:
An optical disc apparatus having the ability to read and/or write data from/on an optical disc with having multiple information layers that are stacked one upon the other and an internal defect, the apparatus comprising: an optical pickup, which irradiates the optical disc with a light beam and which generates a light detection signal based on the light beam that has been reflected from the optical disc; a surface checking section comprising a search section, a defect decision section and a defect size measuring section; and a recording range control section, wherein the surface checking section detects a defective area and produces a defect information list indicating that there is the defective area in the area of the reference layer before data is written on the optical disc, the search section controls the optical pickup before data is written on a storage area of the optical disc, thereby adjusting the location of the light beam on the optical disc and searches a reference one of the multiple information layers stacked for the defective area in the storage area of the optical disc, the defective area being produced due to the internal defect; the defect decision section detects an error based on the light detection signal and determines a portion of the storage area, where the error has occurred, as the defective area; the defect size measuring section measures the size of the defective area in an area of the reference layer and generates the defect information list; and the recording range control section measures, by reference to the defect information list, the storage area such that no data will be written on a perpendicularly projected area, which is defined by projecting the defective area of the reference layer perpendicularly to another information layer.