(19)
(11) EP 1 465 172 A8

(12) CORRECTED EUROPEAN PATENT APPLICATION

(48) Corrigendum issued on:
30.03.2005 Bulletin 2005/13

(43) Date of publication:
06.10.2004 Bulletin 2004/41

(21) Application number: 04005001.5

(22) Date of filing: 03.03.2004
(51) International Patent Classification (IPC)7: G11B 7/24, G11B 7/00
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR
Designated Extension States:
AL LT LV MK

(30) Priority: 04.04.2003 JP 2003102153

(71) Applicant: Kabushiki Kaisha Toshiba
Tokyo (JP)

(72) Inventors:
  • Yoshida, Nobuhisa, c/o Toshiba Corporation
    Minato-ku Tokyo 105-8001 (JP)
  • Takazawa, Koji, c/o Toshiba Corporation
    Minato-ku Tokyo 105-8001 (JP)

(74) Representative: Henkel, Feiler & Hänzel 
Möhlstrasse 37
81675 München
81675 München (DE)

   


(54) Optical disk and optical disk apparatus


(57) In an optical disk (1) of the invention composed of two substrates (1a, 1b) bonded to each other, the level of double refraction is set to 60 nm or less in a read-only disk, to 60 nm or less in a write-once type disk, and to 40 nm or less in a rewritable type disk, respectively.