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1. (WO1998049680) RECORDING MEDIUM AND OPTICAL PICKUP DEVICE
Latest bibliographic data on file with the International Bureau   

Pub. No.: WO/1998/049680 International Application No.: PCT/JP1998/001894
Publication Date: 05.11.1998 International Filing Date: 23.04.1998
Chapter 2 Demand Filed: 24.08.1998
IPC:
G11B 7/007 (2006.01) ,G11B 7/013 (2006.01) ,G11B 7/12 (2006.01)
[IPC code unknown for G11B 7/07]
G PHYSICS
11
INFORMATION STORAGE
B
INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
7
Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation, reproducing using an optical beam at lower power; Record carriers therefor
007
Arrangement of the information on the record carrier, e.g. form of tracks
013
for discrete information, i.e. where each information unit is stored in a distinct location
G PHYSICS
11
INFORMATION STORAGE
B
INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
7
Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation, reproducing using an optical beam at lower power; Record carriers therefor
12
Heads, e.g. forming of the optical beam spot or modulation of the optical beam
Applicants: TSUCHIYA, Yoichi[JP/JP]; JP (UsOnly)
SANYO ELECTRIC CO., LTD.[JP/JP]; 5-5, Keihanhondori 2-chome Moriguchi-shi Osaka 560-8677, JP (AT, BE, CH, CN, CY, DE, DK, ES, FI, FR, GB, GR, ID, IE, IT, KR, LU, MC, NL, PT, SE)
Inventors: TSUCHIYA, Yoichi; JP
Agent: FUKAMI, Hisao ; Sumitomo Bank Minamimori-machi Building 1-29, Minamimori-machi 2-chome Kita-ku Osaka-shi Osaka 530-0054, JP
Priority Data:
9/10943225.04.1997JP
Title (EN) RECORDING MEDIUM AND OPTICAL PICKUP DEVICE
(FR) SUPPORT D'ENREGISTREMENT ET DISPOSITIF DE LECTURE OPTIQUE
Abstract:
(EN) A double density CD (5) for an optical pickup device (10) which includes a laser (1) which emits a laser beam with a wavelength $g(l)$g(m)m and an objective (4) with a numerical aperture NA has a track pitch TP$g(m)m which satisfies a formula: 0.7 < TP/($g(l)/NA) < 0.8 and/or a shortest pit length L$g(m)m which satisfies a formula: 0.40 < L/($g(l)/NA) < 0.45. Therefore, the jitter is suppressed and the reproducing characteristics can be improved.
(FR) Ce disque compact double densité (5), destiné à un dispositif de lecture optique (10) comportant un laser (1) émettant un faisceau laser d'une longueur $g(l)$g(m)m ainsi qu'un objectif (4) doté d'une ouverture numérique NA, comprend un entre-axes de pistes TP$g(m)m correspondant à la formule 0,7 < TP/($g(l)/NA) < 0,8 et/ou une longueur de micro-cuvettes très courte L$g(m)m correspondant à la formule 0,40 < L/($g(l)/NA) < 0,45. De cette manière, on supprime la gigue et on améliore les caractéristiques de reproduction.
front page image
Designated States: CN, ID, KR, US
European Patent Office (EPO) (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE)
Publication Language: Japanese (JA)
Filing Language: Japanese (JA)