Optical information recording medium
AssigneeNikon Corporation
InventorsHiroshi Konishi, Seiji Morita
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AssigneeNikon Corporation
InventorsHiroshi Konishi, Seiji Morita
Estimating the term…
In a DVD-R, lands 1 and grooves 2 are alternately formed in a spiral configuration; the lands 1 form projecting parts, and the grooves 2 form recessed parts 2. Recorded information is written into the grooves 2, while land pre-pits 3 are formed in some portions of the lands 1. The land pre-pits 3 form recessed parts, and the respective land pre-pits 3 cover the entire width of the corresponding land 1 as shown in the figures. These land pre-pits 3 are arranged so that a a a a>b>0.5×a, where a is the maximum length of the land pre-pits, and b is the minimum length (ordinarily, the minimum length is the shorter of the lengths b1 and b2 of the land pre-pits in the circumferential edge portions of the lands (i.e., the boundary portions with the grooves)). Furthermore, the value of a is set at 0.2 μm to 0.4 μm.
A disc-form optical information recording medium which has meandering grooves and lands and in which the recording and playback of information are performed by means of a light beam which tracks on the above-mentioned grooves, this optical information recording medium further having embossed pits (land pre-pits) that are formed in the lands beforehand, wherein the maximum length a in a above-mentioned land pre-pit is 0.4 μm or less for all above-mentioned land pre-pits, and the relationship between this maximum length a and the minimum length b of the same land pre-pit is such that a>b>0.5×a for all land pre pits.
Dependencies are inferred from the claim text.