Title:
光ディスク媒体及びトラッキング方法
Document Type and Number:
Japanese Patent JP4903081
Kind Code:
B2
Abstract:
A super-resolution material is formed in only a data pit, in a low temperature state of the super-resolution material, reflectivity of each of a pit portion and a space portion and an optical phase difference therebetween are set to be sufficiently small, in a high temperature state, and at least the optical phase difference between the pit and the space is set to be larger than the aforementioned value in an absolute value. Accordingly, by conducting irradiation with an appropriate read power by which substantially only one data track width can be heated to a high temperature state, a good push-pull signal can be obtained even with a track pitch being less than a diffraction limit. At the same time, by an optical device having functions such as a switching means with a DPP type, an offset correcting means of the push-pull signal due to lens shift, a shaping means of the push-pull signal, a learning means of read power, and the like, there is provided an optical disk device that corresponds to the optical disk medium of the present invention and achieves an increase in capacity.
Inventors:
Hiroyuki Minemura
Shintani
Yumiko Anzai
Sotoichiro Eto
Shintani
Yumiko Anzai
Sotoichiro Eto
Application Number:
JP2007131124A
Publication Date:
March 21, 2012
Filing Date:
May 17, 2007
Export Citation:
Assignee:
株式会社日立製作所
International Classes:
G11B7/007; G11B7/09; G11B7/24062
Domestic Patent References:
| JP7147025A | ||||
| JP10188378A | ||||
| JP2003228859A | ||||
| JP2003331437A | ||||
| JP2004227622A | ||||
| JP2005078782A | ||||
| JP2005100526A | ||||
| JP2006107588A | ||||
| JP4580380B2 | ||||
| JP4685754B2 |
Foreign References:
| US20080159119 |
Attorney, Agent or Firm:
Yusuke Hiraki