Patent ID: 6930976

Claim:
An optical recording medium, comprising: lands and grooves, said optical recording medium at least being reproducible by either of i) a light beam having a first wavelength λ 1 set in a range of not less than 630 nm to not more than 680 nm, and ii) a light beam having a second wavelength λ 2 set in a range of not less than 390 nm to not more than 430 nm, wherein said groove depth d satisfies the conditions of: λ 1 / n 1 ×(3/64)≦ d≦ λ 1 / n 1 ×(13/64); and λ 2 / n 2 ×(4/64)≦ d≦ λ 2 / n 2 ×(12/64), wherein n 1 and n 2 indicate refractive indexes of said optical recording medium for the first wavelength λ 1 and the second wavelength λ 2 respectively.