OPTICAL INFORMATION RECORDING MEDIUM, OPTICAL INFORMATION REPRODUCING APPARATUS AND OPTICAL INFORMATION RECORDING APPARATUS

• Main Authors: HAYASHI KAZUHIRO, OHNO EIJI, MOHRI MASANARI
• Format: Patent
• Language: English
• Published: 19.11.2007
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; PERFORMING OPERATIONS; PHYSICS; PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCESIN A PLASTIC STATE; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

An optical information recording medium, an optical information reproducing device, and an optical information recording device are provided to apply larger disc clamping force to a recording medium. An optical information recording medium(110) comprises a signal board, a signal recording layer(103), a transparent protection layer(102), and a center hole. The transparent protection layer whose thickness is in a range of 10~200mum is installed on the signal recording layer. An information recording and reproducing operation is performed by irradiating a beam to the signal recording layer through the transparent protection layer. A keeping area is positioned between the center hole and a signal area corresponding to an area with the signal recording layer. A projection unit(100) projected more than the surface of the transparent protection layer is formed at a side of a light incident surface for the area between the center hole and the keeping area.