Optical information recording medium and method of marking bca (burst cutting area) into the same

An optical information recording medium comprising:

• a read-only information recording portion;
• and
• a BCA (Burst Cutting Area) portion formed by laser marking, wherein
• a reflective film on an information recording surface of the read-only information recording portion and a reflective film on the BCA portion are formed of the same material,
• composition of the reflective film includes Ag as a main component, and includes at least one of Nd and Gd, at least one of Sn and In, and Cu,
• the composition of the reflective film includes at least one of Nd and Gd of 0.1 atom % or more and 3.0 atom % or less in total,
• the composition of the reflective film includes at least one of Sn and In of 3 atom % or more and 12 atom % or less in total,
• the composition of the reflective film includes Cu of 1.3 atom % or more and 13 atom % or less, and
• recorded information is reproduced from the information recording surface of the read-only information recording portion and a BCA signal is reproduced from the BCA portion, using blue-violet laser reproducing light.

An optical information recording medium comprising:

• an information recording portion including a single-layer or multilayer information recording surface having a reflective film, information being recorded on the information recording surface at least once, and a BCA (Burst Cutting Area) portion formed by laser marking, wherein
• the reflective film on the single-layer information recording surface or the reflective film on the multilayer information recording surface located at the deepest position from a reproducing-light incident surface of the optical information recording medium is formed of the same material as that of the reflective film on the BCA portion,
• composition of the reflective film includes Ag as a main component and includes at least one of Nd and Gd, and at least one of Sn and In,
• the composition of the reflective film includes at least one of Nd and Gd of 0.1 atom % or more and 3.0 atom % or less in total,
• the composition of the reflective film includes at least one of Sn and In of 3 atom % or more and 12 atom % or less in total, and
• recorded information is reproduced from the information recording surface and a BCA signal is reproduced from the BCA portion, using blue-violet laser reproducing light.

An optical information recording medium comprising:

• an information recording portion including a single-layer or multilayer information recording surface having a reflective film, information being recorded on the information recording surface at least once, and a BCA (Burst Cutting Area) portion formed by laser marking, wherein
• the reflective film on the single-layer information recording surface or the reflective film on the multilayer information recording surface located at the deepest position from a reproducing-light incident surface of the optical information recording medium is formed of the same material as that of the reflective film on the BCA portion,
• composition of the reflective film includes Ag as a main component and includes at least one of Nd and Gd, at least one of Sn and In, and Cu,
• the composition of the reflective film includes at least one of Nd and Gd of 0.1 atom % or more and 3.0 atom % or less in total,
• the composition of the reflective film includes at least one of Sn and In of 3 atom % or more and 12 atom % or less in total,
• the composition of the reflective film includes Cu of 1.3 atom % or more and 13 atom % or less, and
• recorded information is reproduced from the information recording surface and a BCA signal is reproduced from the BCA portion, using blue-violet laser reproducing light.

A method of marking a BCA (Burst Cutting Area) with laser light into an optical information recording medium including a read-only information recording portion, and a BCA (Burst Cutting Area) portion formed by laser marking,

• a reflective film on at least one information recording surface of the read-only information recording portion and a reflective film on the BCA portion being formed of the same material,
• composition of the reflective film including Ag as a main component, and including at least one of Nd and Gd, and at least one of Sn and In,
• the composition of the reflective film including at least one of Nd and Gd of 0.1 atom % or more and 3.0 atom % or less in total, and
• the composition of the reflective film including at least one of Sn and In of 3 atom % or more and 12 atom % or less in total,
• the method comprising the step of:
• irradiating the BCA portion with laser light for marking the BCA from the surface opposite to the surface on which blue-violet laser light is incident to reproduce information from the read-only information recording portion and the BCA portion of the optical information recording medium.

A method of marking a BCA (Burst Cutting Area) with laser light into an optical information recording medium including a read-only information recording portion, and a BCA (Burst Cutting Area) portion formed by laser marking,

• a reflective film on at least one information recording surface of the read-only information recording portion and a reflective film on the BCA portion being formed of the same material,
• composition of the reflective film including Ag as a main component, and including at least one of Nd and Gd, at least one of Sn and In, and Cu,
• the composition of the reflective film including at least one of Nd and Gd of 0.1 atom % or more and 3.0 atom % or less in total, and
• the composition of the reflective film including at least one of Sn and In of 3 atom % or more and 12 atom % or less in total,
• the composition of the reflective film including Cu of 1.3 atom % or more and 13 atom % or less
• the method comprising the step of:
• irradiating the BCA portion with laser light for marking the BCA from the surface opposite to the surface on which blue-violet laser light is incident to reproduce information from the read-only information recording portion and the BCA portion of the optical information recording medium.