Optical data medium for information recording, has cover layer and adhesive layer having preset total thickness, and recorded and readout with focussing objective lens setup having preset numerical aperture

摘要

An optical data medium has an optional barrier layer (2), an information layer (3) containing at least one dye as a light-absorbing compound, optional barrier layer (4) and a cover layer (6), formed sequentially on a substrate (1). Total thickness of layers (5,6) is 10-177 micro m, and medium is recorded and readout with focussing objective lens setup with numerical aperture of 0.8 or more. An optical data medium has an optional barrier layer (2), an information layer (3) containing at least one dye as a light-absorbing compound, an optional barrier layer (4) and a cover layer (6), formed sequentially on a substrate (1). Total thickness of layers (5,6) is 10-177 micro m, and medium is recorded and readout with focussing objective lens setup with numerical aperture of 0.8 or more. The information layer can be recorded using light, and the data medium can be recorded on and read using focussed blue light through the cover layer on the information layer. Preferably a laser light of 360-460 nm is used. The information layer optionally contains a binder. An Independent claim is included for production of optical data media which involves coating a transparent substrate optionally coated with a barrier layer, with a dye optionally in combination with suitable binders and additives and solvents. An intermediate layer and a cover layer are further applied by an adhesive layer.