US Patent 7505384 Optical recording and reproducing apparatus

Laser power adjustment is performed using a power calibration area (PCA) until the PCA is used up. After the PCA is used up, an additional PCA is reserved at the next recording start position and laser power adjustment is performed using the additional PCA. When an additional PCA is reserved, the additional PCA exists between an information file recorded this time and the last one of information files recorded previously in terms of a physical format. However, information test-written into the additional PCA is not regarded as an information file and PMA information is generated only from the information file recorded this time by excluding the test-written information. As a result, a situation is obtained in which the additional PCA does not logically exist on the disk and there will never occur an inconvenient situation where the additional PCA is erroneously reproduced at the time of reproduction.