Recording or reproducing by optical means

GPHYSICS G11Information storage G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER

G11B7/00Recording or reproducing by optical means

G11B7/002Recording, reproducing or erasing systems characterised by the shape or form of the carrier G11B7/0025with cylinders or cylinder-like carriers or cylindrical sections or flat carriers loaded onto a cylindrical surface G11B7/003with webs , filaments or wires G11B7/0031using a rotating head G11B7/0032for moving-picture soundtracks G11B7/0033with cards or other card-like flat carriers G11B7/0037with discs G11B7/00375arrangements for detection of physical defects G11B7/004Recording, reproducing or erasing methods Read, write or erase circuits therefor G11B7/0045Recording G11B7/00451involving ablation of the recording layer G11B7/00452involving bubble or bump forming G11B7/00453involving spectral or photochemical hole burning G11B7/00454involving phase-change effects G11B7/00455involving reflectivity, absorption or colour changes G11B7/00456Recording strategies G11B7/00458Verification G11B7/005Reproducing G11B7/0051involving phase depth effects G11B7/0052involving reflectivity, absorption or colour changes G11B7/0053Reproducing non-user data G11B7/0055Erasing G11B7/00552involving colour change media G11B7/00555involving liquid crystal media G11B7/00557involving phase-change media G11B7/006Overwriting G11B7/0062Overwriting strategies G11B7/0065Recording, reproducing or erasing by using optical interference patterns G11B7/007Arrangement of the information on the record carrier G11B7/00718Groove and land recording G11B7/00736Auxiliary data G11B7/00745Sectoring or header formats within a track G11B7/00772on record carriers storing information in the form of optical interference patterns G11B7/00781Auxiliary information G11B7/0079Zoned data area G11B7/013for discrete information, i.e. where each information unit is stored at a distinct discrete location G11B7/08Disposition or mounting of heads or light sources relatively to record carriers G11B7/081for time base error correction by moving the light beam G11B7/082Aligning the head or the light source relative to the record carrier otherwise than during transducing G11B7/083relative to record carriers storing information in the form of optical interference patterns G11B7/085with provision for moving the light beam into, or out of, its operative position or across tracks, otherwise than during the transducing operation G11B7/08505Methods for track change, selection or preliminary positioning by moving the head G11B7/08511with focus pull-in only G11B7/08517with tracking pull-in only G11B7/08523with both tracking and focusing pull-in G11B7/08529Methods and circuits to control the velocity of the head as it traverses the tracks G11B7/08535to maintain constant velocity during the traverse G11B7/08541involving track counting to determine position G11B7/08547Arrangements for positioning the light beam only without moving the head G11B7/08552using electro-optical elements G11B7/08558using acousto-optical elements G11B7/08564using galvanomirrors G11B7/0857Arrangements for mechanically moving the whole head G11B7/08576Swinging-arm positioners G11B7/08582Sled-type positioners G11B7/08588with position sensing by means of an auxiliary system using an external scale G11B7/08594to access both sides of the disc with the same head assembly G11B7/09with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation G11B7/0901for track following only G11B7/0903Multi-beam tracking systems G11B7/0904Dithered tracking systems G11B7/0906Differential phase difference systems G11B7/0908for focusing only G11B7/0909by astigmatic methods G11B7/0911by far-field method G11B7/0912by push-pull method G11B7/0914by non-optical methods G11B7/0916Foucault or knife-edge methods G11B7/0917Focus-error methods other than those covered by G11B7/0909 - G11B7/0916 G11B7/0925Electromechanical actuators for lens positioning G11B7/0927for focusing only G11B7/0929for tracking only G11B7/093for focusing and tracking G11B7/0932Details of sprung supports G11B7/0933Details of stationary parts G11B7/0935Details of the moving parts G11B7/0937Piezo-electric actuators G11B7/0938servo format G11B7/094Methods and circuits for servo offset compensation G11B7/0941Methods and circuits for servo gain or phase compensation during operation G11B7/0943Methods and circuits for performing mathematical operations on individual detector segment outputs G11B7/0945Methods for initialising servos, start-up sequences G11B7/0946specially adapted for operation during external perturbations not related to the carrier or servo beam G11B7/0948specially adapted for detection and avoidance or compensation of imperfections on the carrier G11B7/095specially adapted for discs G11B7/0953to compensate for eccentricity of the disc or disc tracks G11B7/0956to compensate for tilt, skew, warp or inclination of the disc G11B7/10Interchangeable mountings G11B7/12Heads G11B7/121Protecting the head G11B7/122Flying-type heads G11B7/123Integrated head arrangements G11B7/124the integrated head arrangements including waveguides G11B7/1245the waveguides including means for electro-optical or acousto-optical deflection G11B7/125Optical beam sources therefor G11B7/126Circuits, methods or arrangements for laser control or stabilisation G11B7/1263Power control during transducing G11B7/1267Power calibration G11B7/127Lasers Multiple laser arrays G11B7/1275Two or more lasers having different wavelengths G11B7/128Modulators G11B7/13Optical detectors therefor G11B7/131Arrangement of detectors in a multiple array G11B7/133Shape of individual detector elements G11B7/135Means for guiding the beam from the source to the record carrier or from the record carrier to the detector G11B7/1353Diffractive elements G11B7/1356Double or multiple prisms G11B7/1359Single prisms G11B7/1362Mirrors G11B7/1365Separate or integrated refractive elements G11B7/1367Stepped phase plates G11B7/1369Active plates G11B7/1372Lenses G11B7/1374Objective lenses G11B7/1376Collimator lenses G11B7/1378Separate aberration correction lenses Cylindrical lenses to generate astigmatism Beam expanders G11B7/1381Non-lens elements for altering the properties of the beam G11B7/1384Fibre optics G11B7/1387using the near-field effect G11B7/139Numerical aperture control means G11B7/1392Means for controlling the beam wavefront G11B7/13922passive G11B7/13925active G11B7/13927during transducing G11B7/1395Beam splitters or combiners G11B7/1398Means for shaping the cross-section of the beam G11B7/14specially adapted to record on, or to reproduce from, more than one track simultaneously G11B7/22Apparatus or processes for the manufacture of optical heads G11B7/24Record carriers characterised by shape, structure or physical properties, or by the selection of the material G11B7/24003Shapes of record carriers other than disk shape G11B7/24006Cylindrical or shaft-shaped G11B7/24009Tapes, long films or long sheets G11B7/24012Optical cards G11B7/24015Air-sandwiched disks G11B7/24018Laminated disks G11B7/24021provided with a special shape or structure for centering or eccentricity prevention G11B7/24024Adhesion or bonding G11B7/24027Layers Shape, structure or physical properties thereof G11B7/2403Layers Shape, structure or physical properties thereof G11B7/24033Electrode layers G11B7/24035Recording layers G11B7/24038Multiple laminated recording layers G11B7/24041with different recording characteristics G11B7/24044for storing optical interference patterns G11B7/24047Substrates G11B7/2405being also used as track layers of pre-formatted layers G11B7/24053Protective topcoat layers lying opposite to the light entrance side G11B7/24056Light transmission layers lying on the light entrance side and being thinner than the substrate G11B7/24059specially adapted for near-field recording or reproduction G11B7/24062Reflective layers G11B7/24065Layers assisting in recording or reproduction below the optical diffraction limit G11B7/24067Combinations of two or more layers with specific interrelation G11B7/2407Tracks or pits Shape, structure or physical properties thereof G11B7/24073Tracks G11B7/24076Cross sectional shape in the radial direction of a disk G11B7/24079Width or depth G11B7/24082Meandering G11B7/24085Pits G11B7/24088for storing more than two values G11B7/24091Combinations of pits and tracks with specific interrelation G11B7/24094Indication parts or information parts for identification G11B7/24097Structures for detection, control, recording operation or replay operation Special shapes or structures for centering or eccentricity prevention Arrangements for testing, inspecting or evaluating Containers, cartridges or cassettes G11B7/241characterised by the selection of the material G11B7/242of recording layers G11B7/243comprising inorganic materials only G11B7/2433Metals or elements of groups 13, 14, 15 or 16 of the Periodic System G11B7/2437Non-metallic elements G11B7/244comprising organic materials only G11B7/245containing a polymeric component G11B7/246containing dyes G11B7/2463azulene G11B7/2467azo-dyes G11B7/247methine or polymethine dyes G11B7/2472cyanine G11B7/2475merocyanine G11B7/2478oxonol G11B7/248porphines azaporphines G11B7/249containing organometallic compounds G11B7/2492neutral compounds G11B7/2495as anions G11B7/2498as cations G11B7/25containing liquid crystals G11B7/251comprising inorganic materials dispersed in an organic matrix G11B7/252of layers other than recording layers G11B7/253of substrates G11B7/2531comprising glass G11B7/2532comprising metals G11B7/2533comprising resins G11B7/2534polycarbonates [PC] G11B7/2535polyesters G11B7/2536polystyrene [PS] G11B7/2537epoxy resins G11B7/2538polycycloolefins [PCO] G11B7/2539biodegradable polymers G11B7/254of protective topcoat layers G11B7/2542consisting essentially of organic resins G11B7/2545containing inorganic fillers G11B7/2548consisting essentially of inorganic materials G11B7/256of layers improving adhesion between layers G11B7/257of layers having properties involved in recording or reproduction G11B7/2572consisting essentially of organic materials G11B7/2575resins G11B7/2578consisting essentially of inorganic materials G11B7/258of reflective layers G11B7/2585based on aluminium G11B7/259based on silver G11B7/2595based on gold G11B7/26Apparatus or processes specially adapted for the manufacture of record carriers G11B7/261Preparing a master G11B7/263Preparing and using a stamper G11B7/265Apparatus for the mass production of optical record carriers G11B7/266Sputtering or spin-coating layers G11B7/268Post-production operations G11B7/28Re-recording