Abstract: It is highly precisely determined as to whether or not a laser-irradiated position on an optical disk is positioned within an identification area (BCA) in which identification information is recorded, and the position of the identification information area is efficiently determined. An optical disk apparatus includes an optical pickup for detecting reflected light from an optical disk and generating a light amount signal, and a detecting section for outputting a detection signal which is in accordance with a change in the signal level of the light amount signal, the detection signal indicating that the change has continued for a first predetermined time or longer.

Abstract: An optical disk reproduction apparatus according to the present invention is an optical disk reproduction apparatus capable of reading information from the NBCA of an optical disk 101 having an NBCA, and includes: an optical pickup 103 having an objective lens 120 for converging a light beam onto the optical disk 101, a lens actuator 170 for controlling a position of the objective lens 120, and a photodetector for generating an electrical signal from at least a portion of the light beam having been reflected by the optical disk 101; a transport mechanism 106 for moving the optical pickup 103 along a radial direction of the optical disk; and an NBCA in/out determination section 104 for, based on electrical signal, determining whether an irradiated position of the light beam on the optical disk 101 is located within the NBCA or not.

Abstract: It is highly precisely determined as to whether or not a laser-irradiated position on an optical disk is positioned within an identification area (BCA) in which identification information is recorded, and the position of the identification information area is efficiently determined. An optical disk apparatus includes an optical pickup for detecting reflected light from an optical disk and generating a light amount signal, and a detecting section for outputting a detection signal which is in accordance with a change in the signal level of the light amount signal, the detection signal indicating that the change has continued for a first predetermined time or longer.