Abstract: There is provided a new medium structure to record a bar code for copyright protection or the like in an optical information recording medium capable of recording and reproducing information by a laser with respect to a dye. When a laser beam 30 is irradiated and an optical disc 10 is rotation in the direction of an arrow F, the dye of a recording layer is decomposed, a mark piece MA of a bar code 20 is formed, and a substrate is deformed by heat generated by the dye decomposition. Next, the position of the laser beam 30 is shifted to a position where a part overlaps with the mark piece MA, and when the optical disc is similarly rotated in the direction of the arrow F, a mark piece MB is formed to overlap with the mark piece MA. The above processing is repeated, so that the length of a bar is sequentially lengthened, and the bar code with a length along the standard is formed.

Abstract: An optical information recording medium includes a substrate having a pregroove thereon, an optical recording layer containing a light-absorbing substance composed of a dye absorbing a laser beam, and a light-reflective layer reflecting the laser beam. The ratio of the cross-sectional area of the optical recording layer (i.e., the dye) in the pregroove to the cross-sectional area of the pregroove in the direction of the diameter of the optical information recording medium is about 30% to about 63%. In the optical information recording medium, the phenomenon by which the recording power of the laser beam heats the dye in the optical recording layer and the heat is diffused through the optical recording layer and the light-reflective layer is considered.

Abstract: An optical information recording medium has light interference layers including a recording layer on a substrate. The recording layer includes an organic dye and a photostabilizer which is, for example, the compound of formula 1 wherein at least one of R1 to R8 represents a substituted alkyl group having a terminal cyano group, with the others represent other substituents; Y represents a monovalent or divalent cation; and Xm? represents a monovalent or divalent anion.

Abstract: [Problems] To provide a monomethine dye compound that enables formation of a thin film with high refractive index and excellent optical properties through formation of a homogeneous thin film of dye molecule J-association complex by easy means (spin coating technique) and that has high sensitivity and excels in short mark recording capability so as to be suitable for high speed recording and high density recording, and further to provide an optical information recording medium utilizing the monomethine dye compound and a process for producing the same.

Abstract: An optical information recording medium includes: a substrate having a pre-groove formed thereon; an optical recording layer containing a dye; and a light reflecting layer. The medium has a ratio of a modulation degree at a maximum recording speed to a modulation degree at a minimum recording speed, which is from 1.1 to 1.7.

Abstract: There is provided a new medium structure to record a bar code for copyright protection or the like in an optical information recording medium capable of recording and reproducing information by a laser with respect to a dye. When a laser beam 30 is irradiated and an optical disc 10 is rotation in the direction of an arrow F, the dye of a recording layer is decomposed, a mark piece MA of a bar code 20 is formed, and a substrate is deformed by heat generated by the dye decomposition. Next, the position of the laser beam 30 is shifted to a position where a part overlaps with the mark piece MA, and when the optical disc is similarly rotated in the direction of the arrow F, a mark piece MB is formed to overlap with the mark piece MA. The above processing is repeated, so that the length of a bar is sequentially lengthened, and the bar code with a length along the standard is formed.

Abstract: An optical information recording medium has light interference layers including a recording layer on a substrate. The recording layer includes an organic dye and a photostabilizer which is, for example, the compound of formula 1 wherein at least one of R1 to R8 represents a substituted alkyl group having a terminal cyano group, with the others represent other substituents; Y represents a monovalent or divalent cation; and Xm? represents a monovalent or divalent anion.

Abstract: An optical information recording medium includes a substrate having a pregroove thereon, an optical recording layer containing a light-absorbing substance composed of a dye absorbing a laser beam, and a light-reflective layer reflecting the laser beam. The ratio of the cross-sectional area of the optical recording layer (i.e., the dye) in the pregroove to the cross-sectional area of the pregroove in the direction of the diameter of the optical information recording medium is about 30% to about 63%. In the optical information recording medium, the phenomenon by which the recording power of the laser beam heats the dye in the optical recording layer and the heat is diffused through the optical recording layer and the light-reflective layer is considered.

Abstract: An optical information recording medium comprising a substrate and an overlaying optical interference layer containing a trimethine dibenzoindolenine cyanine dye of a symmetric structure is capable of recording information with a laser beam having a wavelength of 640 nm or longer at a low recording power and the recorded information can be reproduced with the same laser.