Patent ID: 8233375

Claim:
An optical information recording medium, comprising: a first area in which a content is recorded by forming recording marks, one or more of the recording marks being shorter than a length of a resolution limit of an optical system in a reproducing device; and a second area in which medium identification information for specifying a type of the medium is recorded by use of concave portions and/or protrusions formed during production of the optical information recording medium, the concave portions and/or protrusions which form the medium identification information being not shorter than the resolution limit of the optical system, in the second area, (i) unique number presence/absence information for determining whether a medium unique number is present or absent and (ii) information each being further recorded, by use of the concave portions and/or protrusions that are not shorter than the resolution limit of the optical system in the reproducing device, the information (ii) being information for determining a linear velocity in reproduction of the content recorded in the first area so that digital processing is carried out with respect to the content by use of a reproduction clock which is identical to a reproduction clock that is used to carry out digital processing with respect to the second area.