Optical recording medium

Abstract

Provided is an optical information recording medium having excellent C / N and reproduction durability and having no inhibition to high density recording. Moreover, the recording and reproducing of high volume and high density information can be done by a blue laser light of short wavelength, and the recording property may have excellent sensitivity and reflectivity. The optical information recording media carry out the recording and reproducing by a laser light of 450 nm or less, wherein grooves having a track pitch of 200 to 400 nm, a groove depth of 50 to 150 nm and a groove half width of 90 to 200 nm are form on the substrate, and a reflective layer, a recording layer and a covering layer are provided thereon. The recording layer comprises an organic substance having maximum absorption at 600 to 800 nm and 300 to 400 nm of more than 1. When a laser light of 380 to 500 nm wavelength is irradiated through a lens with a numerical aperture (NA) of 0.7 or more to a substrate, the recording layer of the optical information media carry out the recording of information. The recording layer contains organic substance and the substrate has a groove depth of 15 to 45 nm, a track pith of 250 to 400 nm and a half width of groove of 60 to 200 nm an oblique angle of the groove of 40 to 80 DEG.

Description

[0001] This application is a divisional application of the application number 02118520.4 filed by the applicant on April 26, 2002, and the title of the invention is Optical Information Recording Medium. technical field [0002] The present invention relates to an optical information recording medium, and more particularly, to an optical information recording medium capable of recording and reproducing information by laser irradiation. Background technique [0003] There is an increasing demand for high-density optical information recording media (DVDs) for recording and reproducing a large amount of character information, image information, audio information, and the like. Especially recently, in order to correspond to video broadcasted by digital high-definition television, studies on further high-density recording on optical recording media have been actively conducted. As a method for high-density recording, it can be performed by further shortening the laser wavelength u...

AI Technical Summary

Problems solved by technology

[0013] However, studies by the present inventors have shown that when information is recorded by irradiating short-wavelength laser light with a wavelength of 380 to 500 nm with the optical disc described in the above publication, the practically necessary sensitivity cannot be obtained. The recording characteristics are also not at a satisfactory level, so further improvements are necessary

In particular, when the optical disc described in the above-mentioned gazette is irradiated with laser light having a wavelength of 380 to 500 nm, the recording characteristics deteriorate.

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