Patents Examined by William A. Krynsks
  • Patent number: 5503888
    Abstract: An optical recording medium is disclosed which comprises a substrate containing a polycarbonate resin and a recording layer. The substrate contains copolycarbonate resin having constitutional units represented by the formulae (x) and (y) ##STR1## wherein Z of the formula (x) is a direct bond, alkylidene, --O--, --S-- or --SO.sub.2 --; X is H, halogen, alkyl, aryl, aralkyl, alkoxy, aryloxy or aralkyloxy; R.sub.1 is H, alkyl or aralkyl; m is an integer of 1 to 3; Y of the formula (y) is alkylidene, aryl-substituted alkylene, aryl, --O--, --S--, --CO-- or --SO.sub.2 --; and each of R.sub.2, R.sub.3, R.sub.4 and R.sub.5 is H, halogen or alkyl!.
    Type: Grant
    Filed: June 16, 1993
    Date of Patent: April 2, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Osamu Kanome, Hirofumi Kamitakahara, Naoki Kushida, Hitoshi Yoshino, Toshiya Yuasa, Takashi Kai