| US 7,529,175 B2 | ||
| Method for making an optical disc having a track pitch smaller than a recording beam diameter | ||
| Sohmei Endoh, Miyagi (Japan); Noriyuki Saito, Miyagi (Japan); Takahiro Igari, Miyagi (Japan); Takeshi Gouko, Miyagi (Japan); Shinji Minegishi, Shizouka (Japan); and Eijiro Kikuno, Shizuoka (Japan) | ||
| Assigned to Sony Corporation, Tokyo (Japan); and Sony Disc & Digital Solutions, Inc., Tokyo (Japan) | ||
| Filed on Jul. 28, 2006, as Appl. No. 11/495,427. | ||
| Claims priority of application No. 2005-230408 (JP), filed on Aug. 09, 2005. | ||
| Prior Publication US 2007/0036933 A1, Feb. 15, 2007 | ||
| Int. Cl. G11B 7/24 (2006.01) | ||
| U.S. Cl. 369—275.4 [428/64.1] | 2 Claims |
| 1. A recording method whereby an inorganic resist made of an incomplete oxide of a transition metal is formed as a film onto
a substrate and a latent image corresponding to pits is formed onto the inorganic resist by exposure, comprising the steps
of:
feedback controlling an intensity of a laser beam so that a variation in exposure amount is equal to or less than ±1.0%;
performing the exposure by the laser beam whose intensity has been modulated by a pulse signal whose pulse height is first
asserted at first maximum height and then asserted one or more times at intermediate non-zero heights lower than the first
maximum height in a rear portion in a length direction of the pit; and
forming a track pitch smaller than a recording beam diameter by using a high-precision track feeding servo whose track pitch
variation is equal to or less than ±3 nm.
|