EP0176755B1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
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: 1989-12-06
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Expires: 2005-08-26
Abstract
No abstract record available.
Inventors
- 👤 Yoshinari Takemura
- 👤 Kazuaki Obara
- 👤 Michiyoshi Nagashima
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 12:34
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: 10
Claim 1
Independent Claim
215 words
An optical disk comprising: a disk having grooves (51; I, II, III; 28, 29, 30, 31; V o , V 1 , V 2 ) of helical or circular pattern and of V-shaped cross-section thereon, header regions (8, 9; I(K), I(K+1), ..., I(K+j); 19, 25, 26, 27) on at least two of said helical or circular grooves (51; I, II, III; 28, 29, 30, 31; V 0 , V 1 , V 2 ), having reference signals recorded in form of pits (4) that are parts with changed depth (Ad) across the width of said helical or circular grooves (51; I, II, III; 28, 29, 30, 31; V a , V 1 , V 2 ) partially cutting the ridge (r 1 , r bc , r de ) of neighboring grooves (51; I, II, III; 28, 29, 30, 31; V o , V 1 , V 2 ), characterized in that said parts with changed depth (Ad) are disposed in a manner that reference signals of each- other-neighboring grooves (51; I, II, III; 28, 29, 30, 31; V 0 , V 1 , V 2 ) are apart from each other in longitudinal direction of said grooves (51; I, II, III; 28, 29, 30, 31; V 0 , V 1 , V 2 ).
Claim 2
Dependent Claim
215 words
An optical disk comprising: a disk having grooves (51; I, II, III; 28, 29, 30, 31; V o , V 1 , V 2 ) of helical or circular pattern and of V-shaped cross-section thereon, header regions (8, 9; I(K), I(K+1), ..., I(K+j); 19, 25, 26, 27) on at least two of said helical or circular grooves (51; I, II, III; 28, 29, 30, 31; V 0 , V 1 , V 2 ), having reference signals recorded in form of pits (4) that are parts with changed depth (Ad) across the width of said helical or circular grooves (51; I, II, III; 28, 29, 30, 31; V a , V 1 , V 2 ) partially cutting the ridge (r 1 , r bc , r de ) of neighboring grooves (51; I, II, III; 28, 29, 30, 31; V o , V 1 , V 2 ), characterized in that said parts with changed depth (Ad) are disposed in a manner that reference signals of each- other-neighboring grooves (51; I, II, III; 28, 29, 30, 31; V 0 , V 1 , V 2 ) are apart from each other in longitudinal direction of said grooves (51; I, II, III; 28, 29, 30, 31; V 0 , V 1 , V 2 ).
Claim 3
Dependent Claim
120 words
An optical disk in accordance with claim 1 comprising: header regions ( 19, 25, 26, 27) in respective one of which said reference signals are recorded and respective one of which has at least twice length (AR) 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 (V o , V 1 , V 2 ) are made alternately with respect to said reading region and said following region, thereby to dispose vacant parts in both neighboring grooves (V o , V 1 , V 2 ) to parts which are recorded with the reference signals.
Claim 4
Dependent Claim
62 words
An optical disk in accordance with claim 2, wherein each of said header regions (25, 26, 27) has at least twice length (AR) necessary for recording one reference signal plus a length 2n times width (2P) of one of said grooves (V 0 , V 1 , V 2 ), and said disk is to be driven 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
141 words
Method for reproducing reference signal from an optical disk according to any of the claims 1 to 6 comprising the steps of: irradiating two light beams (1, 2) on pits (4) of reference signals in a header region (8, 9; I(K), I(K+1), ..., I(K+j); 19, 25, 26, 27) on two neighboring tracks of oblique surface (A, B, C, D, E, F) on helical or circular grooves (51; I, II, III; 28, 29, 30, 31; V o , V 1 , V 2 ) of V-shaped section, detecting reflection light from said tracks and producing two electric signals (p, r; P1, P2) corresponding to data on respective two tracks characterized in detecting coincidence between said two electric signals (p, r; P1, P2) thereby to produce a valid reference signals only when said two electric signals (p, r; P1, P2) coincide each other.
Claim 9
Dependent Claim
55 words
Method for reproducing address values in reference signals from a recording disk in accordance with claim 7 comprising the steps of: reproducing two address values (ad1, ad2) from the components of reference signals of two neighboring grooves, and producing an address value (v) by carrying out an interpolation to said two address values (ad1, ad2).
Claim 10
Dependent Claim
47 words
Method for reproducing address values in reference signals from a recording disk in accordance with claim 8 comprising the steps of: adding said two address values (ad1, ad2) together, to produce a sum of them and dividing said sum by 2, to produce an address value (v).
References Cited (Backward Citations)
No citation records indexed.
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