| US 7,544,428 B2 | ||
| Information recording medium, and apparatuses for reproducing, recording, and recording and reproducing thereof, and methods for reproducing, recording, and recording and reproducing thereof | ||
| Tetsuya Kondo, Kanagawa-ken (Japan); and Kenji Oishi, Yokohama (Japan) | ||
| Assigned to Victor Company of Japan, Limited, Yokohama (Japan) | ||
| Filed on Oct. 13, 2005, as Appl. No. 11/163,289. | ||
| Application 11/163289 is a continuation of application No. 10/453653, filed on Jun. 04, 2003, granted, now 6,982,127. | ||
| Claims priority of application No. 2002-162591 (JP), filed on Jun. 04, 2002. | ||
| Prior Publication US 2006/0028969 A1, Feb. 09, 2006 | ||
| This patent is subject to a terminal disclaimer. | ||
| Int. Cl. G11B 11/105 (2006.01) | ||
| U.S. Cl. 428—836 [428/848.3; 428/64.2; 428/64.4; 369/13.55] | 12 Claims |
| 1. An information recording medium at least comprising:
a substrate;
a second recording layer formed on the substrate for recording information;
a second light transmitting layer formed on the second recording layer;
a first recording layer formed on the second light transmitting layer for recording different information from that recorded
in the second recording layer; and
a first light transmitting layer formed on the first recording layer;
the second recording layer being formed with a second continuous microscopic pattern of a plurality of raised portions and
recessed portions formed alternately viewed from the first light transmitting layer side; and
the first recording layer being formed with a first continuous microscopic pattern of a plurality of raised portions and recessed
portions formed alternately viewed from the first light transmitting layer side and different from the second microscopic
pattern;
both the first microscopic pattern and the second microscopic pattern satisfying a relation of P≤λ/NA, wherein P is a pitch
of the raised portion, λ is a wavelength of reproducing light for reproducing the first recording layer and the second recording
layer, and NA is a numerical aperture of an objective lens; and
a sidewall of the raised portion of the first microscopic pattern and the raised portion of the second microscopic pattern
being continuously wobbled in alternating sections corresponding to auxiliary information and a reference clock, wherein the
auxiliary information is a phase-shift keying modulation wave having two different phases and the reference clock is a sinusoidal
wave having a single frequency respectively, and
wherein both sidewalls of the raised portion are parallel with each other.
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