Optical recording medium and entertainment system that employs it

An optical recording medium having a surface on which information is written and/or read by laser light, comprising:

• a first information recording part formed from a first material and a second information recording part formed from a second material,
• said first and second information recording parts being radially divided along the surface of the optical recording medium,
• wherein said first material has a composition that does not change when subjected to a laser light adapted for reading said first material,
• wherein said second material is photosensitive and changes material properties when subjected to one of said laser light adapted for reading said first material and a high-output laser light, and
• wherein information of said second information recording part is erased by one of a uniform reaction and a discoloration of said photosensitive second material due to irradiation of laser light.

An optical recording medium having a surface on which information is written and/or read by laser light comprising:

• a first information recording part formed from a first material and a second information recording part formed from a second material,
• said first and second information recording parts being radially divided alone the surface of the optical recording medium,
• wherein said first material has a composition that does not change when subjected to a laser light adapted for reading said first material,
• wherein said second material is photosensitive and changes material properties when subjected to one of said laser light adapted for reading said first material and a high-output laser light, and
• wherein said second material is photosensitive and chances material properties when subjected to said laser light adapted for reading said first material and when subjected to high-output laser light.

A computer system operable to read a program in combination with an optical recording medium on which program information is written and/or read by laser light, said optical recording medium comprising:

• a first information recording part formed from a first material and a second information recording part formed from a second material,
• said first and second information recording parts being radially divided along the surface of the optical recording medium,
• wherein said first material has a composition that does not change when subjected to a laser light adaptable for reading said first material, and
• wherein said second material is photosensitive and changes material properties when subjected to said laser light adaptable for reading said first material.

A computer system is operable to read a program in combination with an optical recording medium on which program information is written and/or read by laser light, said optical recording medium comprising:

• a first information recording part formed from a first material and a second information recording part formed from a second material,
• said first and second information recording parts being radially divided along the surface of the optical recording medium,
• wherein said first material has a composition that does not change when subjected to a laser light adapted for reading said first material,
• wherein said second material is photosensitive and changes material properties when subjected to one of said laser light adapted for reading said first material and a high-output laser light, and
• wherein said second material is photosensitive and changes material properties when subjected to said laser light adapted for reading said first material and when subjected to high-output laser light.

An optical recording medium having a surface on which information is written and/or read by laser light, comprising:

• a first information recording part formed from a first material and a second information recording part formed from a second material,
• said first and second information recording pans being radially divided along the surface of the optical recording medium,
• wherein said first material has a composition that does not chance when subjected to a laser light adapted for reading said first material,
• wherein said second material is photosensitive and changes material properties when subjected to one of said laser light adapted for reading said first material and a high-output laser light, and
• wherein said first ad second information recording materials include first and second aluminum vapor deposition films formed thereon and wherein said second aluminum vapor deposition film is thinner than said first aluminum vapor deposition film.