Optical recording medium, and optical information device

Abstract

An optical recording medium and an optical information device that improve the quality of a servo signal and a reproduction signal. In the optical recording medium, when shape-wise thicknesses tr, tr, tr, and trof a cover layer (), a first intermediate layer (), a second intermediate layer (), and a third intermediate layer () are respectively converted into thicknesses t, t, t, and tof the respective corresponding layers each having a predetermined refractive index 'no', a defocus amount with respect to a layer having a refractive index nrα and a thickness trα (satisfying: 1≦α≦n (where α is a positive integer and n is an integer of 4 or more)), and a defocus amount with respect to a layer having the refractive index 'no' and a thickness tα (satisfying: 1≦α≦n (where α is a positive integer and n is an integer of 4 or more)) are equal to each other. Further, the thicknesses t, t, t, and tsatisfy |t−(t+t+t)|≧1 μm, a difference between any two values of the thicknesses t, t, t, and tis set to 1 μm or more, and |(t+t)−(t+t)|≧1 μm.