OPTICAL DISK DEVICE AND OPTICAL DISK REPRODUCING METHOD

• Main Author: FUJITA SHINJI
• Format: Patent
• Language: English
• Published: 19.01.2012
• Subjects: INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; PHYSICS

PROBLEM TO BE SOLVED: To strike a balance between guarantee of reproduction light resistance with respect to a recording type multilayer optical disk, and suppression of return light noise with respect to a read-only optical disk.SOLUTION: A laser driver 13 for supplying a driving current to a laser light source 1 includes a reproduction light emitting current supply part 14 for supplying a reproduction light emitting current, a high-frequency superimposition part 15 for superimposing a high-frequency current onto the reproduction light emitting current, and a current clip part 18 for limiting the maximum value of the driving current supplied to the laser light source. If an optical disk 30 is a recordable disk, the current clip part 18 is set to be a first clip level in order to limit the driving current. If the optical disk is a read-only disk, the current clip part 18 is set to be a second clip level larger than the first clip level.