Wenderoth, Lind & Ponack, LLP
Optical recording medium with transmissivity controlling layer
 Disclosed is a novel optical recording medium which is a multi-layered body comprising: (a) a substrate disk of a transparent material; (b) a first protective layer formed on one surface of the substrate disk; (c) a recording layer formed on the first protective layer, which is made from a material capable of causing a change in the optical properties in response to light or heat; (d) a second protective layer formed on the recording layer; (e) a transmissivity-controlling layer formed on the second protective layer, which is made from a material capable of reversibly and continuously causing a change in the optical properties in response to light or heat at a speed higher than the speed of changes in the recording layer; and, optionally, (f) a third protective layer formed on the transmissivity-controlling layer. Method and apparatus for recording of signals and reproduction of recorded signals by using the above defined optical recording medium are also disclosed. 
Japan as represented by Director General of Agency of Industrial Science and Technology
G G G G G G G G G G G G
G11B G11B G11B G11B G11B G11B G11B G11B G11B G11B G11B G11B
additional inventional additional additional additional additional additional additional inventional additional additional inventional
Nobufumi Junji Takashi
Atoda Tominaga Nakano