(19)
(11) EP 1 434 210 A8

(12) CORRECTED EUROPEAN PATENT APPLICATION

(48) Corrigendum issued on:
06.10.2004 Bulletin 2004/41

(43) Date of publication:
30.06.2004 Bulletin 2004/27

(21) Application number: 03258010.2

(22) Date of filing: 18.12.2003
(51) International Patent Classification (IPC)7: G11B 7/24, G11B 23/40, G11B 7/26, G11B 7/007
(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 PT RO SE SI SK TR
Designated Extension States:
AL LT LV MK

(30) Priority: 18.12.2002 JP 2002366195
04.06.2003 JP 2003159288

(71) Applicant: Ricoh Company, Ltd.
Tokyo 143-8555 (JP)

(72) Inventor:
  • Shimofuku, Akira
    Atsugi-shi Kanagawa (JP)

(74) Representative: Mounteney, Simon James 
MARKS & CLERK, 57-60 Lincoln's Inn Fields
London WC2A 3LS
London WC2A 3LS (GB)

   


(54) Optical recording medium with visible pattern formed in ROM area


(57) A disk-type optical recording medium that has a visible pattern in its read-only area. The visible pattern is produced making use of change in reflectance of the disk, which is caused by change in product W*L of a width (W) and a length (L) of an nT pit formed in the read-only area, where n denotes a natural number, and T denotes clock time.
The fabrication process for the stamper and for the medium are also described.