Patent US2303583A successfully refreshed from Google Patents.
EP0973155A2
Expired / Lapsed
EP
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Optical disk and optical disk apparatus employing the same
Assignee: Panasonic Holdings Corp
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Filing: 1999-07-14
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Granted: —
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Expires: 2019-07-14
Abstract
Abstract An optical disk includes tracks and grooves, the grooves being formed with a pitch equal to or greater than about λ/NA. A first array of pits is provided at a position which is shifted by a predetermined amount with respect to each track in one of two directions substantially perpendicular to the tracks, the first array of pits being formed with a predetermined pitch, where the predetermined pitch is a function of a pitch of the grooves taking a value within a range from about 0 to about λ/NA. A second array of pits is provided at a position which is shifted by a predetermined amount with respect to the track in the other one of the two directions substantially perpendicular to the tracks, the second array of pits being formed with a predetermined pitch, where the predetermined pitch is a function of the pitch of the grooves taking a value within the range from about 0 to about λ/NA. λ is a wavelength of a light beam which is radiated on the optical disk, and NA is a numerical aperture of a lens.
Inventors
- 👤 Kouichi Takamine
- 👤 Shin-Ichi Yamada
- 👤 Takashi Ishida
- 👤 Atsushi Nakamura
- 👤 Seiji Nishiwaki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 09:05
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/2407; G11B27/00; G11B27/10; G11B27/19; G11B7/007; G11B7/00718; G11B7/00745; G11B7/08; G11B7/09; G11B7/0938; G11B7/095; G11B27/28; G11B27/30; G11B27/3027; G11B7/0901; G11B7/24085
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
187 words
An optical disk comprising tracks and grooves, the
grooves being formed with a pitch equal to or greater
than about λ/NA, wherein a first array of pits is provided at a position
which is shifted by a predetermined amount with respect to
each track in one of two directions substantially
perpendicular to the tracks, the first array of pits being
formed with a predetermined pitch, where the predetermined
pitch is a function of a pitch of the grooves taking a value
within a range from about 0 to about λ/NA, wherein a second array of pits is provided at a position
which is shifted by a predetermined amount with respect to
the track in the other one of the two directions
substantially perpendicular to the tracks, the second array
of pits being formed with a predetermined pitch, where the
predetermined pitch is a function of the pitch of the grooves
taking a value within the range from about 0 to about λ/NA, wherein λ is a wavelength of a light beam which is
radiated on the optical disk; and NA is a numerical aperture of a lens.
Claim 2
Dependent Claim
55 words
An optical disk according to claim 1, wherein the first
array of pits and the second array of pits are provided
between an address region and a data region, the address
region being used for recording information indicating one
of the tracks on the optical disk, and the data region being
used for recording data.
Claim 3
Dependent Claim
149 words
An optical disk according to claim 1, wherein the optical disk includes: a first address region formed at a position which is
shifted by a predetermined amount with respect to each track
in the one of the two directions substantially perpendicular
to the tracks, location information of one of the tracks
being recorded in the first address region; and a second address region formed at a position which is
shifted by a predetermined amount with respect to each track
in the other one of the two directions substantially
perpendicular to the tracks, the first address region and
the second address region each including a PLL
synchronization region for generating a reproduction clock,
and wherein the first array of pits is provided in the PLL
synchronization region in the first address region; and the second array of pits is provided in the PLL
synchronization region in the second address region.
Claim 4
Dependent Claim
35 words
An optical disk according to claim 1, wherein each pit
in the first array of pits has a shape which is substantially
identical with a shape of each pit in the second array of
pits.
Claim 5
Dependent Claim
113 words
An optical disk according to claim 1, wherein a reproduction time of a pit in the first array
of pits is n times as large as a reproduction clock cycle; wherein a reproduction time of a pit in the second array
of pits is n times as large as the reproduction clock cycle; wherein a reproduction time of a space between adjoining
pits in the first array of pits is m times as large as the
reproduction clock cycle; and wherein a reproduction time of a space between adjoining
pits in the second array of pits is m times as large as the
reproduction clock cycle, where n and m are natural numbers.
Claim 6
Dependent Claim
15 words
An optical disk according to claim 5, wherein n is 3 and
m is 4.
Claim 7
Dependent Claim
15 words
An optical disk according to claim 5, wherein n is 4 and
m is 3.
Claim 8
Dependent Claim
63 words
An optical disk according to claim 1, wherein the predetermined pitch of the first array of
pits is in the range of about 0.96 µm to about 1.035 µm; wherein the predetermined pitch of the second array of
pits is in the range of about 0.96 µm to about 1.035 µm; wherein λ is about 660 nm; and wherein NA is about 0.6.
Claim 9
Dependent Claim
63 words
An optical disk according to claim 1, wherein the predetermined pitch of the first array of
pits is in the range of about 0.61 µm to about 0.667 µm; wherein the predetermined pitch of the second array of
pits is in the range of about 0.61 µm to about 0.667 µm; wherein λ is about 425 nm; and wherein NA is about 0.6.
Claim 10
Dependent Claim
25 words
An optical disk according to claim 1, wherein the pitch
of the grooves is in the range of about λ/NA to
about λ/NA × 1.9.
Claim 11
Dependent Claim
258 words
An optical disk apparatus comprising: a reproduction signal generation section for converging
a light beam on an optical disk to reproduce information
recorded on the optical disk, the optical disk comprising tracks and grooves, the
grooves being formed with a pitch equal to or greater than
about λ/NA, wherein a first array of pits is provided at a
position which is shifted by a predetermined amount with
respect to each track in one of two directions substantially
perpendicular to the tracks, the first array of pits being
formed with a predetermined pitch, where the predetermined
pitch is a function of a pitch of the grooves taking a value
within a range from about 0 to about λ/NA, wherein a second array of pits is provided at a
position which is shifted by a predetermined amount with
respect to the track in the other one of the two directions
substantially perpendicular to the tracks, the second array
of pits being formed with a predetermined pitch, where the
predetermined pitch is a function of the pitch of the grooves
taking a value within the range from about 0 to about λ/NA, and an off-tracking detection section for detecting an
offset between the light beam and a center of the track,
based on, among the information reproduced by the
reproduction signal generation section, information concerning
the first array of pits and the second array of pits; wherein λ is a wavelength of a light beam which is
radiated on the optical disk; and NA is a numerical aperture of a lens.
Claim 12
Dependent Claim
98 words
An optical disk apparatus according to claim 11, wherein the optical disk apparatus further comprises
a tracking servo section for controlling the light beam so
as to follow the track based on a tracking error signal
indicating the offset between the light beam and the center
of the track, and wherein, based on the offset between the light beam and
the center of the track as detected by the off-tracking
detection section, the tracking servo section changes a
target position of the light beam so that the light beam
is located substantially at the center of the track.
Claim 13
Dependent Claim
106 words
An optical disk apparatus according to claim 11, wherein the information concerning the first array of
pits and the second array of pits is an amplitude of a
reproduction signal from the first array of pits and an
amplitude of a reproduction signal from the second array
of pits as detected by the reproduction signal generation
section, and wherein the off-tracking detection section detects the
offset between the light beam and the center of the track
based on a difference between the amplitude of the
reproduction signal from the first array of pits and the
amplitude of the reproduction signal from the second array
of pits.
Claim 14
Dependent Claim
92 words
An optical disk apparatus according to claim 11, wherein the off-tracking detection section calculates
an amplitude based on a difference between a value
representing a peak envelope and a value representing a
bottom envelope of a reproduction signal generated by the
reproduction signal generation section, and wherein the off-tracking detection section calculates
a difference between an amplitude of a reproduction signal
obtained by scanning the first array of pits with the light
beam and an amplitude of a reproduction signal obtained by
scanning the second array of pits with the light beam.
Claim 15
Dependent Claim
164 words
An optical disk apparatus according to claim 11, wherein the off-tracking detection section calculates
a peak envelope detection value difference and a bottom
envelope detection value difference, the peak envelope detection value difference being
defined as a difference between a value representing a peak
envelope of a reproduction signal obtained by scanning the
first array of pits with the light beam and a value
representing a peak envelope of a reproduction signal
obtained by scanning the second array of pits with the light
beam, the bottom envelope detection value difference being
defined as a difference between a value representing a bottom
envelope of a reproduction signal obtained by scanning the
first array of pits with the light beam and a value
representing a bottom envelope of a reproduction signal
obtained by scanning the second array of pits with the light
beam, and wherein the off-tracking detection section calculates
a difference between the peak envelope detection value
difference and the bottom envelope detection value
difference.
Claim 16
Dependent Claim
112 words
An optical disk apparatus according to claim 14, further
comprising an address region detection section for
generating a signal indicating that the light beam is located
on an address region on the optical disk, based on the
reproduction signal produced by the reproduction signal
generation section, wherein, based on the signal indicating that the light
beam is located on the address region on the optical disk,
the address region detection section generates a timing with
which to detect the offset between the light beam and the
center of the track while the light beam is scanning over
a preceding one of the first array of pits and the second
array of pits.
Claim 17
Dependent Claim
112 words
An optical disk apparatus according to claim 14, further
comprising an address region detection section for
generating a signal indicating that the light beam is located
on an address region on the optical disk, based on the
reproduction signal produced by the reproduction signal
generation section, wherein, based on the signal indicating that the light
beam is located on the address region on the optical disk,
the address region detection section generates a timing with
which to detect the offset between the light beam and the
center of the track while the light beam is scanning over
a subsequent one of the first array of pits and the second
array of pits.
Claim 18
Dependent Claim
79 words
An optical disk apparatus according to claim 14, wherein the off-tracking detection section detects the
offset between the light beam and the center of the track
by use of the light beam scanning over the first array of
pits and the second array of pits, and wherein the off-tracking detection section detects the
offset holds a previously detected value until a subsequent
time the light beam scans over the first array of pits and
the second array of pits.
Claim 19
Dependent Claim
112 words
An optical disk apparatus according to claim 15, further
comprising an address region detection section for
generating a signal indicating that the light beam is located
on an address region on the optical disk, based on the
reproduction signal produced by the reproduction signal
generation section, wherein, based on the signal indicating that the light
beam is located on the address region on the optical disk,
the address region detection section generates a timing with
which to detect the offset between the light beam and the
center of the track while the light beam is scanning over
a preceding one of the first array of pits and the second
array of pits.
Claim 20
Dependent Claim
112 words
An optical disk apparatus according to claim 15, further
comprising an address region detection section for
generating a signal indicating that the light beam is located
on an address region on the optical disk, based on the
reproduction signal produced by the reproduction signal
generation section, wherein, based on the signal indicating that the light
beam is located on the address region on the optical disk,
the address region detection section generates a timing with
which to detect the offset between the light beam and the
center of the track while the light beam is scanning over
a subsequent one of the first array of pits and the second
array of pits.
Claim 21
Dependent Claim
79 words
An optical disk apparatus according to claim 15, wherein the off-tracking detection section detects the
offset between the light beam and the center of the track
by use of the light beam scanning over the first array of
pits and the second array of pits, and wherein the off-tracking detection section detects the
offset holds a previously detected value until a subsequent
time the light beam scans over the first array of pits and
the second array of pits.
Claim 22
Dependent Claim
41 words
An optical disk apparatus according to claim 11, further
comprising a tracking servo section for controlling the
light beam so as to be located substantially at the center
of the track, based on the offset detected by the off-tracking
detection section.
References Cited (Backward Citations)
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