Patent ID: 6661769
Filing Date: 2003-12-09
Classification: G11B

Abstract:
An optical storage medium having guide grooves with a pitch of Gp1 between adjacent grooves, comprising:groove Gnâˆ’1 and groove Gn+1 adjacent to opposite sides of an n-th groove Gn, said groove Gnâˆ’1 and groove Gn+1 being both intermittent grooves with non-groove spaces formed therein, providing an area where pitch Gp2 of groove Gn is equivalent to twice pitch Gp1; and satisfying &lgr;/NA&gE;Gp1&gE;&lgr;/(2Â·NA) where &lgr; is a wavelength of a beam emitted for recording or reproducing data, and NA is the numerical aperture of the convergent system for converging the beam on the optical storage medium.