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US4858221A Expired / Lapsed US ⏱️ 0.0 years remaining

Preformatted information medium and optical reader device

Assignee: DIT ALCATEL THOMSON GIGADISC SA
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Filing: 1986-05-09
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Granted: 1989-08-15
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Expires: 2006-05-09
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Abstract

Abstract The invention relates to optical memories making use of optical interaction between an incident ray and an information medium (83) capable of having data written thereon and of having data read therefrom, which data is organized in a adjacent track elements which are marked by prerecorded patterns. The invention provides an information medium (83) and a reader device therefor (84, 85, 86, 87, 88) including means (89, 91, 92, 93, 94) for sampled tracking of the track elements on the basis of patterns which are offset from the track scan line, said patterns forming discontinuous periodic wave sequences whose offset edges are symmetrically disposed about the middle of the inter-track gap. The invention is particularly applicable to optical memories using a preformated disk capable of recording, of being read, and where appropriate of being erased, with data in digital form.

Inventors

  • 👤 Rene Romeas

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 23:25
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/2407; G11B7/24085; G11B21/00; G11B21/02; G11B21/10; G11B21/106; G11B23/00; G11B23/30; G11B23/36; G11B27/00; G11B27/10; G11B27/19; G11B7/08; G11B7/09; G11B7/0938; G11B2220/00; G11B2220/20; G11B27/28; G11B27/30; G11B27/3027

Claims Analysis

Total Claims: 15
Claim 1
Independent Claim 54 words
A pre-grooved information medium, comprising: a recording surface; a plurality of pre-recorded patterns in the form of spaced marks which define boundaries for tracking at least two tracks on said surface, wherein said pre-recorded patterns are located to be symmetrical to a midline disposed mid-way between said two tracks for use in tracking control.
Claim 2
Dependent Claim 54 words
A pre-grooved information medium, comprising: a recording surface; a plurality of pre-recorded patterns in the form of spaced marks which define boundaries for tracking at least two tracks on said surface, wherein said pre-recorded patterns are located to be symmetrical to a midline disposed mid-way between said two tracks for use in tracking control.
Claim 3
Dependent Claim 16 words
An information medium as in claim 1 wherein each said pattern consists of one geometric shape.
Claim 4
Dependent Claim 59 words
A medium as in claim 1 wherein there are a plurality of said track elements and said track elements are concentric around an annular area, and further comprising a plurality of orthogonal lines forming intersections with said scanning lines and segmenting said scanning lines into equal portions, said orthogonal straight lines passing through the center of said annular area.
Claim 5
Dependent Claim 16 words
A medium as in claim 3 further comprising an annular ring concentric with said annular area.
Claim 6
Dependent Claim 63 words
A medium as in claim 1 wherein said patterns are located to have equal offsets of opposite sign around said scanning line to form a periodical series along each of said scanning lines, said offsets being successively of one sign then of the opposite sign, and wherein said offsets are uniformed from one end to the other end of each of said patterns.
Claim 7
Dependent Claim 32 words
A medium as in claim 1 wherein each said pattern comprises a central part that is offset with respect to the scanning line, and to terminal portions located on said scanning line.
Claim 8
Dependent Claim 16 words
A medium as in claim 6 wherein said pattern is in the shape of an "X".
Claim 9
Dependent Claim 26 words
A medium as in claim 1 wherein said offsets are constituted by a predetermined gap between the edge of a pattern and a nearest scan line.
Claim 10
Dependent Claim 30 words
A medium as in claim 8 wherein said patterns include at least one centered portion with a half length of said centered portion being different from predetermined gap when negative.
Claim 11
Dependent Claim 22 words
A medium as in claim 1 wherein each said pattern consists of two geometric shapes disposed to be symmetric to said midline.
Claim 12
Dependent Claim 111 words
A pre-grooved information medium, comprising: a recording surface; a plurality of pre-recorded patterns in the form of spaced marks which define at least first, second and third tracks on said surface, wherein at least one of said pre-recorded patterns are located to be symmetrical to a midline disposed midway between said first and second tracks for use in tracking control in both of said first and second tracks, and at least one of said prerecorded patterns are located to be symmetrical to a midline disposed midway between said second and third tracks for use in tracking control of said second and third tracks, said second track defined between said two midlines.
Claim 13
Dependent Claim 111 words
A pre-grooved information medium, comprising: a recording surface; a plurality of pre-recorded patterns in the form of spaced marks which define at least first, second and third tracks on said surface, wherein at least one of said pre-recorded patterns are located to be symmetrical to a midline disposed midway between said first and second tracks for use in tracking control in both of said first and second tracks, and at least one of said prerecorded patterns are located to be symmetrical to a midline disposed midway between said second and third tracks for use in tracking control of said second and third tracks, said second track defined between said two midlines.
Claim 14
Dependent Claim 62 words
A pre-grooved information medium, comprising: a recording surface; a plurality of pre-recorded patterns in the form of spaced marks which define boundaries for tracking at least two tracks on said surface, wherein all of said pre-recorded patterns are located to be symmetrical to a midline disposed mid-way between said two tracks for use in tracking control for both of said two tracks.
Claim 15
Dependent Claim 62 words
A pre-grooved information medium, comprising: a recording surface; a plurality of pre-recorded patterns in the form of spaced marks which define boundaries for tracking at least two tracks on said surface, wherein all of said pre-recorded patterns are located to be symmetrical to a midline disposed mid-way between said two tracks for use in tracking control for both of said two tracks.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-08-14 1993-02-13 1993-08-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-08-14 1997-02-13 1997-08-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-08-14 2001-02-13 2001-08-15 $7700.00 Window Closed / Lapsed

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