Patents Assigned to Hitachi Softwear Engineering Co., Ltd.
  • Patent number: 6850470
    Abstract: An optical disc apparatus and method for recording and reproducing information to/from an optical disc, including discrimination of the optical disc, reading control information in an un-recordable area formed in an inner periphery of the optical disc, conducting focus control based on a focus error signal in a recordable area formed outside of the un-recordable area, and determining an optimum offset value of the focus error signal in the recordable area. Further, adjustment in amplitude of a reproduced signal from an inner periphery of the recordable area is conducted, test-writing in the inner periphery of the recordable area is conducted, test-writing in an outer periphery of the recordable area is conducted, and adjustment in amplitude of a reproduced signal from the outer periphery of the recordable area is conducted. The respective operations are conducted sequentially so as to make the optical disc in a reproducible and recordable condition.
    Type: Grant
    Filed: August 8, 2002
    Date of Patent: February 1, 2005
    Assignees: Hitachi, Ltd., Hitachi Softwear Engineering Co., Ltd.
    Inventors: Shigeki Yamazaki, Hiroyuki Minamura, Hisataka Sugiyama, Tetsuya Fushimi, Makoto Itagaki
  • Patent number: 6438078
    Abstract: An optical disc apparatus and method for recording and reproducing information to/from an optical disc, including discrimination of the optical disc, reading control information in an un-recordable area formed in an inner periphery of the optical disc, conducting focus control based on a focus error signal in a recordable area formed outside of the un-recordable area, and determining an optimum offset value of the focus error signal in the recordable area. Further, adjustment in amplitude of a reproduced signal from an inner periphery of the recordable area is conducted, test-writing in the inner periphery of the recordable area is conducted, test-writing in an outer periphery of the recordable area is conducted, and adjustment in amplitude of a reproduced signal from the outer periphery of the recordable area is conducted. The respective operations are conducted sequentially so as to make the optical disc in a reproducible and recordable condition.
    Type: Grant
    Filed: October 3, 2001
    Date of Patent: August 20, 2002
    Assignees: Hitachi, Ltd., Hitachi Softwear Engineering Co., Ltd.
    Inventors: Shigeki Yamazaki, Hiroyuki Minamura, Hisataka Sugiyama, Tetsuya Fushimi, Makoto Itagaki