Optical recording medium and recording/reading method therefor
In a single-sided incident type optical recording medium having a plurality of dye containing recording layers, sufficient reflectance and excellent recording characteristics necessary to record or read information in or from a dye containing recording layer positioning farther from a side from which a light beam comes in can be obtained. The optical recording medium has a first substrate ( 21 ) having a guide groove, a first dye containing recording layer ( 22 ), a semitransparent reflective layer ( 23 ), an intermediate layer ( 24 ), a second dye containing recording layer ( 25 ), a reflective layer ( 26 ) and a second substrate ( 27 ) having a guide groove. Information is recorded or read in or from the first dye containing recording layer ( 22 ) and the second dye containing recording layer ( 25 ) by irradiating the light beam from the first substrate's side. The depth of the guide groove on the second substrate is within a range from 1/100×λ to ⅙×λ where λ represents the recording/reading wavelength.
1. A recording/reading method for an optical recording medium comprising a first dye containing recording layer and a second dye containing recording layer, in which information is recorded in or read from said first dye containing recording layer and said second dye containing recording layer, which has a thick film portion and a thin film portion, by irradiating a light beam from one side thereof, said recording/reading method comprising the steps of:
irradiating said light beam to said thin film portion of said second dye containing recording layer through said first dye containing recording layer to record or read information in or from said second dye containing recording layer.
2. The recording/reading method for an optical recording medium according to claim 1 , wherein said thick film portion and said thin film portion of said second dye containing recording layer are formed correspondingly to a concave portion and a convex portion, respectively, on a substrate formed on an opposite side to said side, from which said light beam is irradiated.
3. The recording/reading method for an optical recording medium according to claim 1 comprising the steps of:
irradiating said light beam to a thick film portion of said first dye containing recording layer to record or read information in or from said first dye containing recording layer.
4. The recording/reading method for an optical recording medium according to claim 3 , wherein said thick film portion and said thin film portion of said first dye containing recording layer are formed correspondingly to a concave portion and a convex portion, respectively, on a substrate formed on said side, from which said light beam is irradiated.