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Pub. No.:    WO/2004/029938    International Application No.:    PCT/IB2003/004092
Publication Date: 08.04.2004 International Filing Date: 18.09.2003
G11B 7/135 (2012.01)
Applicants: KONINKLIJKE PHILIPS ELECTRONICS N.V. [NL/NL]; Groenewoudseweg 1, NL-5621 BA Eindhoven (NL) (For All Designated States Except US).
HENDRIKS, Bernardus, H., W. [NL/NL]; (NL) (For US Only).
DE JONGH, Mathijs [NL/NL]; (NL) (For US Only).
COENE, Willem, M., J., M. [BE/NL]; (NL) (For US Only).
LIEDENBAUM, Coen, T., H., F. [NL/NL]; (NL) (For US Only)
Inventors: HENDRIKS, Bernardus, H., W.; (NL).
DE JONGH, Mathijs; (NL).
COENE, Willem, M., J., M.; (NL).
LIEDENBAUM, Coen, T., H., F.; (NL)
Agent: VISSER, Derk; Philips Intellectual Property & Standards, Prof. Holstlaan 6, NL-5656 AA Eindhoven (NL)
Priority Data:
02078957.4 24.09.2002 EP
Abstract: front page image
(EN)An optical scanning device for scanning an optical record carrier comprising an information layer. Crosstalk cancellation is provided using a phase modulating element (40, 140) for generating a non-rotationally-symmetric phase profile in a subsidiary radiation beam. The phase profile varies with an azimuthal angle measured about the optical axis of the beam portion, the phase profile varying such that successively different phases are introduced in at least five locations which are each at successive azimuthal angles (&phgr;1, &phgr;2, &phgr;N) and each at a given radial distance from the optical axis, wherein the phase profile is such that the phases introduced, when taken in modulo 2&pgr; form, successively cycle through 0 to 2&pgr; at least twice, whereby the subsidiary beam spot is provided with an intensity distribution on the information layer which overlaps that of the side-lobe of the main beam spot.
(FR)L'invention porte sur un dispositif de balayage optique permettant de balayer un support d'enregistrement optique comprenant une couche d'informations. Pour annuler la diaphonie, on utilise un élément modulateur de phase (40, 140) destiné à générer un profil de phase symétrique non rotatif dans un faisceau de rayonnement subsidiaire. Le profil de phase varie en fonction d'un angle azimutal mesuré autour de l'axe optique du faisceau, le profil de phase variant de manière à introduire successivement différentes phases dans au moins cinq emplacements qui forment les différents angles azimutaux ($g(f)1, $g(f)2, $g(f)N) et sont à une distance radiale donnée de l'axe optique, le profil de phase étant tel que les phases introduites, prises sous une forme modulo 2$g(p), forment successivement un cycle allant de 0 à 2$g(p) au moins deux fois, le point du faisceau subsidiaire étant pourvu d'une distribution d'intensité sur la couche d'informations qui chevauche celle du lobe latéral du point du faisceau principal.
Designated States: AE, AG, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, BZ, CA, CH, CN, CO, CR, CU, CZ, DE, DK, DM, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MA, MD, MG, MK, MN, MW, MX, MZ, NI, NO, NZ, OM, PG, PH, PL, PT, RO, RU, SC, SD, SE, SG, SK, SL, SY, TJ, TM, TN, TR, TT, TZ, UA, UG, US, UZ, VC, VN, YU, ZA, ZM, ZW.
African Regional Intellectual Property Organization (GH, GM, KE, LS, MW, MZ, SD, SL, SZ, TZ, UG, ZM, ZW)
Eurasian Patent Organization (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM)
European Patent Office (AT, BE, BG, CH, CY, CZ, DE, DK, EE, ES, FI, FR, GB, GR, HU, IE, IT, LU, MC, NL, PT, RO, SE, SI, SK, TR)
African Intellectual Property Organization (BF, BJ, CF, CG, CI, CM, GA, GN, GQ, GW, ML, MR, NE, SN, TD, TG).
Publication Language: English (EN)
Filing Language: English (EN)