Patent ID: 7701838

Claim:
An optical information medium comprising: an information bearing surface having projections and depressions and/or capable of forming recorded marks, wherein the information borne by the projections and the depressions and/or by the recorded marks is read based on a change in reflectance, and a functional layer having a function of increasing a spatial resolution, wherein said functional layer includes an element selected from the group consisting of Nb, Mo, W, Mn, Pt, C, Si, Ge, Ti, Zr, V, Cr, Fe, Co, Ni, Pd, Sb, Ta, Al, In, Cu, Sn, Te, Zn, and Bi, and wherein a thickness of the functional layer lies within the following values for Nb up to 100 nm, for Mo up to 70 nm, for W up to 70 nm, for Mn up to 100 nm, for Pt up to 40 nm, for C up to 100 nm, for Si up to 100 nm, for Ge up to 100 nm, for Ti up to 100 nm, for Zr up to 100 nm, for V up to 100 nm, for Cr up to 30 nm, for Fe up to 80 nm, for Co up to 70 nm, for Ni up to 70 nm, for Pd up to 40 nm, for Sb up to 100 nm, for Ta up to 100 nm, for Al up to 20 nm, for In up to 100 nm, for Cu up to 10 nm, for Sn up to 40 nm, for Te up to 70 nm, for Zn between 40 nm to 90 nm, and for Bi between 25 nm to 70 nm.