Edwards Wildman Palmer LLP
Optical information recording medium reproducing apparatus, method for reproducing optical information recording medium, program for reproducing optical information recording medium, and computer readable recording medium
An optical information recording medium reproducing apparatus 1 includes: a signal detecting/extracting section 15 extracting, from reproduction signal data, extracted reproduction signal data corresponding to a predetermined data pattern; a calculating circuit 10 calculating, from the extracted reproduction signal data, a reproducing power control value for controlling laser light reproducing power; and a reproducing power control section 16 controlling the reproducing power based on the reproducing power control value. The predetermined data pattern is obtained from a space which is sandwiched between marks of λ/2NA or longer and is shorter than λ/4NA and/or a mark which is sandwiched between spaces of λ/2NA or longer and is shorter than λ/4NA. Therefore, even when environmental temperature changes in reproduction, the optical information recording medium reproducing apparatus capable of reproducing a super resolution medium including marks each shorter than λ/4NA optimally controls laser light reproducing power and prevents degradation of reproduction signal quality.
Sharp Kabushiki Kaisha
G G
G11B G11B
inventional additional
Hideharu Masaki Hirohisa Yasuhiro Jun
Tajima Yamamoto Yamada Harada Akiyama