公开(公告)号：EP1764788A4

公开(公告)日：2009-01-21

申请号：EP05752913

申请日：2005-06-23

Applicant: PANASONIC CORP

Inventor： FUJIUNE KENJI ,  KONDO KENJI ,  OKADA YUU

IPC: G11B7/125 ,  G11B7/085

CPC classification number: G11B7/08523 ,  G11B7/13925 ,  G11B2007/0013

Abstract: A search time increases if spherical aberration has to be varied for each radial position owing to the influence of a disk or lens tilt. An optical disk device has spherical aberration search means (spherical aberration setter (52)) for varying the amount of spherical aberration applied to a light beam, focus search means (Fc movement amount calculator (47) and Fc search drive generator (49)) for moving the focus of the light beam from a current information surface to an aimed information surface, track search means (Tk movement amount calculator (48) and Tk search drive generator (50)) for moving the focus of the light beam from a current track to an aimed track, and search procedure instruction means (search procedure instructor (41)) for operating, in a search, the spherical aberration search means, the focus search means, and the track search means, in that order. A search time is reduced by simultaneously performing spherical aberration variation at the time of a movement in a layer direction and that at the time of a movement in a radial direction.

公开(公告)号：EP1710790A4

公开(公告)日：2009-05-06

申请号：EP05709414

申请日：2005-01-27

Applicant: PANASONIC CORP

Inventor： SHOJI MAMORU ,  HINO YASUMORI ,  SATO TAKAHIRO ,  OKADA YUU

IPC: G11B7/0045 ,  G11B7/006 ,  G11B7/125

CPC classification number: G11B7/1267 ,  G11B7/00456 ,  G11B7/0062

Abstract: A recording power determination method for determining a recording power of an optical beam for recording data on an information storage medium includes the steps of recording test data on the information storage medium at a plurality of test recording powers; reading the test data recorded at each test recording power, generating a signal, and measuring a modulation factor of the signal corresponding to each test recording power; calculating a product of an n'th power of each test recording power and the corresponding modulation factor, thereby obtaining a plurality of products corresponding to the plurality of test recording powers, where n is a value of exponent and is a real number other than 1; calculating a first recording power based on the correlation between the plurality of test recording powers and the plurality of products; and calculating the recording power based on the first recording power.

公开(公告)号：EP1746587A4

公开(公告)日：2008-12-10

申请号：EP05734455

申请日：2005-04-19

Applicant: PANASONIC CORP

Inventor： FUJIUNE KENJI ,  OKADA YUU

IPC: G11B7/085 ,  G11B7/09

CPC classification number: G11B7/094 ,  G11B7/0945

Abstract: An optical disc device for regulating the gain and offset of neutral control with high accuracy in a short time. The optical disc device comprises a semiconductor laser (11), a condenser lens (13), a tracking actuator (15), a main TE generator (20), a sub-TE generator (21), an LE generator (40), a neutral filter (42), a circuit offset detector (50), a stray light offset detector (51), an offset corrector (53), a device commander (56), and an offset commander (54). The circuit offset detector (50), the stray light offset detector (51), and the offset corrector (53) correct offset of a signal from the LE generator (40). The device commander (56) outputs a signal indicating the device state by any one of search operation, record operation, reproduction operation, and waiting. The offset commander (54) gives a command to perform offset correction at a time when a signal from the device commander (56) switches to search operation from other state.