| 摘要 |
<P>PROBLEM TO BE SOLVED: To quickly and precisely measure the radial position of a radial end of a recorded BCA code. Ž<P>SOLUTION: A controller 60 moves the irradiated position with a laser beam in the radial direction of an optical disk DK from an initial radial position to the radial end of a burst cutting area (BCA). While moving the irradiated position with the laser beam, the controller 60 extracts an instantaneous value relating to the bar section of the burst cutting area in a signal created on the basis of reflected light from the optical disk DK. Then, when the extracted instantaneous value becomes a set value indicating the radial end of the burst cutting area, the controller 60 calculates the radius value of the burst cutting area. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
|
