Patent EP0176755A2 successfully refreshed from Google Patents.
EP0176755A2
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Optical disk and method for reproducing reference signal therefrom
Assignee: Panasonic Holdings Corp
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Filing: 1985-08-26
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Granted: —
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Expires: 2005-08-26
Abstract
Abstract In an optical disk. pits of the reference signals in header regions are disposed to be apart each other in longitudinal direction of the groove, and thereby undesirable interference or crosstalk of the reference signals in neighboring V-grooves are eliminated; and in reproducing of such reference signals, two laser beam spots are irradiated on a pair of oblique surface tracks in a groove, and two electric signals made by detecting two reflection lights are examined whether they have coincidence, and when the coincidence is confirmed the signals are used as valid reference signals.
Inventors
- 👤 Yoshinari Takemura
- 👤 Kazuaki Obara
- 👤 Michiyoshi Nagashima
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 16:33
CPC Classifications
G; G11; G11B; G11B19/00; G11B19/20; G11B19/24; G11B27/00; G11B27/10; G11B27/19; G11B27/24; G11B7/00; G11B7/004; G11B7/005; G11B7/0053; G11B7/007; G11B7/00745; G11B7/24; G11B7/2407; G11B7/24073; G11B7/24076; G11B7/24085; G11B2220/00; G11B2220/20; G11B27/28; G11B27/30; G11B27/3027
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
87 words
An optical dish comprising: a disk having grooves of helical or circular circular pattern and of V-shaped cross-section thereon, header regions on at least one of said helical and circular grooves, having reference signals recorded in form of pits that are parts with changed depth across width of said helical or circular grooves, charactrereized in that said parts with changed depth are disposed in a manner that parts which has said reference signals of each-other-neighboring grooves are apart from each other in longitudinal direction of said groove.
Claim 2
Dependent Claim
87 words
An optical dish comprising: a disk having grooves of helical or circular circular pattern and of V-shaped cross-section thereon, header regions on at least one of said helical and circular grooves, having reference signals recorded in form of pits that are parts with changed depth across width of said helical or circular grooves, charactrereized in that said parts with changed depth are disposed in a manner that parts which has said reference signals of each-other-neighboring grooves are apart from each other in longitudinal direction of said groove.
Claim 3
Dependent Claim
96 words
An optical disk in accordance wiht claim I comprising header regions in respective one of which said reference signals are recorded and respective one of which has at least twice length necessary for recording one reference signal, is divided into a leading region and a following region and is recorded with said recording signals in such a staggered manner that recording in each-other neighboring grooves are made alternately with respect to said leading region and said following region, thereby to dispose vacant parts in both neighboring grooves to parts which are recorded with the reference signals.
Claim 4
Dependent Claim
48 words
An optical disk in accordance with claim 2, wherein each of said header regions has at least twice length necessary for recording one reference signal plus a length 2n times width of one of said groove, and said disk is to be drived in a constant linear velocity.
Claim 5
Dependent Claim
16 words
An optical disk in accordance with claim 1, wherein reference signals are recorded in alternate grooves.
Claim 6
Dependent Claim
24 words
An optical disk in accordance with claim 1, wherein address values in reference signals are recorded in a manner to vary by even number.
Claim 7
Dependent Claim
24 words
An optical disk in accordance with claim 1, wherein address values in reference signals are recorded in a manner to vary by odd number.
Claim 8
Dependent Claim
139 words
Method for reproducing reference signal from a recording disk which has grooves of helical or circular pattern and of V-shaped cross section thereon, each of said groove having two recording tracks on oblique surface therein, the method comprising the steps of irradiating two light beams on pits of reference signals in a header region on two neighboring tracks of oblique surface on helical or circular grooves of V shaped section wherein said pits are disposed in a manner that the parts of each other neighboring grooves are apart from each other in longitudinal direction of said groove, detecting reflection light from said tracks and producing two electric signals corresponding to data on respective two tracks and detecting coincidence between said two electric signals thereby to produce a valid reference signals only when said two electric signals coincide each other.
Claim 9
Dependent Claim
139 words
Method for reproducing reference signal from a recording disk which has grooves of helical or circular pattern and of V-shaped cross section thereon, each of said groove having two recording tracks on oblique surface therein, the method comprising the steps of irradiating two light beams on pits of reference signals in a header region on two neighboring tracks of oblique surface on helical or circular grooves of V shaped section wherein said pits are disposed in a manner that the parts of each other neighboring grooves are apart from each other in longitudinal direction of said groove, detecting reflection light from said tracks and producing two electric signals corresponding to data on respective two tracks and detecting coincidence between said two electric signals thereby to produce a valid reference signals only when said two electric signals coincide each other.
Claim 10
Dependent Claim
92 words
Method for reproducing address values in reference signals from a recording disk in accordance with claim 7, wherein in reproducing in a non-reference-signal-recorded groove which is other than grooves having reference signals recorded therein, comprising the steps of: after said detecting of reflection light from said tracks and producing two electric signals corresponding to data on respective two tracks, reproducing two address values from the components of reference signals of two neighboring grooves, and producing an address value of said non-reference-signal-recorded groove by carrying out an interpolation to said two address values.
Claim 11
Dependent Claim
104 words
Method for reproducing address values in reference signals from a recording disk in accordance with claim 8, wherein in reproducing in a now reference signal recorded groove which is other than grooves having reference signals recorded therein, comprising the steps of: after said detecting of reflection light from said tracks and producing two electric signals s corresponding to data on respective two tracks, reproducing two address values from the components of reference signals of two neighboring grooves, adding said two address values together, to produce a sum of them and dividing said sum by 2, to produce an address value of said non-reference-signal-recorded groove.
References Cited (Backward Citations)
No citation records indexed.
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