Patent ID: 7050387
Filing Date: 2006-05-23
Classification: G11B,Y10T

Abstract:
1. An optical storage medium comprising: a first substrate; a recording layer formed on the first substrate to store first information as being reproducible with irradiation of a laser beam; a reflective layer formed on the recording layer; a second transparent substrate, the laser beam being incident to the second substrate in reproduction; and a bonding layer provided between the first and the second substrates, the first and second substrates being bonded to each other by the bonding layer via the reflective layer, the bonding layer being made of ultraviolet-hardened resin including at least one type of photochromic dye, to store second information on the bonding layer, the second information being visible through the second transparent substrate when the photochromic dye is colored by being exposed to light of a first specific wavelength different from a wavelength of the laser beam, the photochromic dye thus colored remaining unchanged against the laser beam.