JP2506867C - - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk capable of recording, reproducing and erasing digital signals such as a video disk, a digital audio disk (for example, a compact disk), a still image, and a document file. is there. 2. Description of the Related Art In general, optical disks are regarded as promising as information media because of their high information density and low noise, and have been commercialized as video disks and digital audio disks. FIG. 3 shows an outline of a compact disk which is a conventional general digital audio disk. This is because the PCM-converted digital signal is recorded in a bit sequence on the resin substrate,
It is reproduced by a semiconductor laser beam. In FIG. 3, 1 is a disk, 2 is a resin substrate, 3 is a digital signal portion in the form of a bit string engraved on the resin substrate 2, 4 is a reflection film formed on the surface thereof, and 5 is a reflection film 4
Is a label printing film provided on the protection film 5, and 7 is a semiconductor laser beam for reproduction. The reflection film 4 is required for reproducing digital signals, the protective film 5 is required for protecting the reflection film, and the label printing film 6 is required for disc identification. Conventionally, a read-only optical disk in which information is formed in advance as a bit-sequence digital signal and which is read and reproduced by a semiconductor laser beam has been the mainstream. In recent years, studies have been made on write-once optical disks for recording and reproducing information and erasable optical disks for recording and erasing information. The general structure is shown in FIG. In FIG. 2, a recording film 9 is formed on a resin or glass substrate 8 and a protective film 10 is formed thereon, and there is no insulating film and no reflective film. SUMMARY OF THE INVENTION Problems to be Solved by the Invention However, in the above-described configuration, since the optical change such as the transmittance or the reflectance of the recording film itself with respect to light is small, the C / N is small and the reliability is poor. And incompatibilities with compact discs. The present invention has been made in view of the above problems, and provides an optical disk having high stability and reliability with good mass productivity. Means for Solving the Problems In order to solve the above problems, the present invention provides a guide groove, or an insulating film formed on a resin substrate provided with guide grooves and sector information, on the insulating film A recording film containing a cyanine dye is formed, a reflection film is formed on the recording film, and a protective film is formed on the reflection film. According to the present invention, an insulating film is formed on a resin substrate provided with guide grooves, or guide grooves and sector information, and a recording film containing a cyanine dye is formed on the insulating film. By forming a reflective film on the recording film and forming a protective film on the reflective film, the optical change of the small-contrast recording film is covered by a reflective film having a high reflectivity, whereby stability is improved. It is an object of the present invention to provide a highly reliable optical disk with good mass productivity and to provide an erasable optical disk which is compatible with a compact disk. Embodiment An optical disc according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an enlarged view of a main part of a cross section without showing an optical disk of the present invention. Reference numeral 11 denotes a resin substrate made of polycarbonate PC, and reference numeral 12 denotes a spiral guide groove provided on the resin substrate 11 to facilitate tracing. Reference numeral 13 denotes an insulating film provided on the resin substrate 11 and made of about 1000% silicon oxide SiO. Reference numeral 14 denotes a recording film of a cyanine dye of about 1000 ° formed on the insulating film 13, which is applied by a spinner method. Reference numeral 15 denotes an aluminum Al reflection film of about 1000 ° provided on the recording film 14. Reference numeral 16 denotes a protective film of an ultraviolet curable resin of about 10 μm provided on the aluminum Al reflective film 15. When a recording or erasing laser beam (not shown) is applied to the recording film 14 from the direction of the reading surface of the resin substrate 11, a signal is recorded or erased due to a change in the transmittance of the recording film 14. . In this case, it is necessary to raise the temperature of the recording film 14 to a temperature equal to or higher than the transition temperature Tc in order to cause a change in the optical transmittance of the recording film 14. For this reason, the temperature of the resin substrate 11 rises and thermal degradation occurs. Prevent this,
Insulating film 13 is required for thermal isolation. By reproducing the signal recorded in this way with a reproducing laser beam (not shown), an optical change can be read. In addition, the provision of the aluminum Al reflection film makes it possible to increase the reflectance and to be compatible with a compact disk. As information provided on the resin substrate 11, it is also effective to provide concentric guide grooves and sectors indicating position information instead of spiral guide grooves for facilitating tracing. As the insulating film, in addition to silicon oxide SiO, a transparent heat-resistant inorganic oxide such as titanium oxide TiO, or an inorganic thin film such as artificial diamond is effective. As the recording film, a film containing a cyanine dye, whose transmittance or the like changes optically by irradiation with a writing or erasing laser beam, is used. As the reflection film, a metal thin film having a reflectance of 80% or more, such as titanium Al, is effective in addition to aluminum Al. As the protective film, in addition to the ultraviolet curing resin, silicon oxide SiO, titanium oxide Ti
An inorganic oxide such as O is effective. Effect of the Invention As described above, the present invention forms an insulating film on a resin substrate provided with guide grooves, or guide grooves and sector information, and forms a recording film containing a cyanine dye on the insulating film. By forming a reflective film on the recording film and forming a protective film on the reflective film, the properties of the cyanine dye to the light of the recording film itself are not good, but due to the presence of the aluminum Al reflective film, In order to improve optical contrast, C /
N is increased, and an optical disk with high reliability and stability can be provided. In addition, by providing a reflective film and an insulating film, it has a high reflectivity and can prevent thermal degradation of the resin substrate when erasing signals, so erasing is possible with compatibility with compact discs It is possible to provide a simple optical disk.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged cross-sectional view of a main part showing an optical disk of the present invention, FIG. 2 is an enlarged cross-sectional view of a main part showing a conventional optical disk, and FIGS. FIG. 1 is a plan view, a cross-sectional view, and an enlarged view of a main part of a compact disk of the present invention. 11 ... resin substrate, 12 ... guide groove, 13 ... insulating film, 14 ... recording film, 15 ... reflective film, 16 ... protective film.

Claims (1)

Claims: (1) An insulating film is formed on a resin substrate provided with a guide groove or a guide groove and sector information, and a recording film containing a cyanine dye is formed on the insulating film. An optical disc, comprising: a reflective film formed on a recording film; and a protective film formed on the reflective film. (2) The optical disc according to claim 1, wherein the insulating film is a transparent heat-resistant inorganic oxide such as silicon oxide SiO or titanium oxide or an inorganic thin film such as artificial diamond. (3) The optical disc according to claim 1, wherein the transmittance of the recording film changes when the recording film is irradiated with a laser beam for writing and erasing. (4) The reflection film is a metal thin film such as aluminum Al, titanium Ti, etc.
2. The optical disk according to claim 1, wherein said optical disk has the above-mentioned reflectance. (5) The optical disc according to claim 1, wherein the protective film is made of an inorganic oxide such as silicon oxide SiO or titanium oxide or an organic film such as an ultraviolet curable resin.