G
SECTION G — PHYSICS
 G

Note(s)

  1. In this section, the following term is used with the meaning indicated:
    • "variable" (as a noun) means a feature or property (e.g., a dimension, a physical condition such as temperature, a quality such as density or colour) which, in respect of a particular entity (e.g., an object, a quantity of a substance, a beam of light) and at a particular instant, is capable of being measured; the variable may change, so that its numerical expression may assume different values at different times, in different conditions or in individual cases, but may be constant in respect of a particular entity in certain conditions or for practical purposes (e.g., the length of a bar may be regarded as constant for many purposes).
  2. Attention is drawn to the definitions of terms or expressions used, appearing in the notes of several of the classes in this section, in particular those of "measuring" in class G01 and "control" and "regulation" in class G05.
  3. Classification in this section may present more difficulty than in other sections, because the distinction between different fields of use rests to a considerable extent on differences in the intention of the user rather than on any constructional differences or differences in the manner of use, and because the subjects dealt with are often in effect systems or combinations, which have features or parts in common, rather than "things", which are readily distinguishable as a whole. For example, information (e.g., a set of figures) may be displayed for the purpose of education or advertising (G09), for enabling the result of a measurement to be known (G01), for signalling the information to a distant point or for giving information which has been signalled from a distant point (G08). The words used to describe the purpose depend on features that may be irrelevant to the form of the apparatus concerned, for example, such features as the desired effect on the person who sees the display, or whether the display is controlled from a remote point. Again, a device which responds to some change in a condition, e.g., in the pressure of a fluid, may be used, without modification of the device itself, to give information about the pressure (G01L) or about some other condition linked to the pressure (another subclass of class G01, e.g., G01K for temperature), to make a record of the pressure or of its occurrence (G07C), to give an alarm (G08B), or to control another apparatus (G05).

    The classification scheme is intended to enable things of a similar nature (as indicated above) to be classified together. It is therefore particularly necessary for the real nature of any technical subject to be decided before it can be properly classified.

  
INSTRUMENTS
 G11
INFORMATION STORAGE
 G11B
INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D; photosensitive materials or processes for photographic purposes G03C; electrography, electrophotography, magnetography G03G; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards, G06K; transferring data from one type of record carrier to another G06K 1/00; printing of data from record carriers G06K 3/00; arrangements for producing a permanent visual presentation of the output data G06K 15/00; arrangements or circuits for control of indicating devices using static means to present variable information G09G; details of scanning-probe apparatus, in general G12B 21/00; coding, decoding or code conversion, in general H03M; circuits for coupling output of reproducer to radio receiver H04B 1/20; television signal recording H04N 5/76, H04N 9/79; loudspeakers, microphones, gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)
 G11B

Note(s)

  1. This subclass covers:
    • recording or playback of information by relative movement between a record track and a transducer, the transducer directly producing, or being directly actuated by, modulation in the track being recorded or played-back, and the extent of modulation corresponding to the signal being recorded or played-back;
    • apparatus and machines for recording or playback, and parts thereof, such as heads;
    • record carriers for use with such apparatus and machines;
    • associated working of other apparatus with such apparatus and machines.
  2. In this subclass, the following terms or expressions are used with the meanings indicated:
    • "record carrier" means a body, such as a cylinder, disc, card, tape, or wire, capable of permanently holding information, which can be read-off by a sensing element movable relatively to the record carrier; [7]
    • "head" includes any means for converting sinusoidal or non-sinusoidal electric wave-forms into variations of the physical condition of at least the adjacent surface of the record carrier, or vice versa;
    • "near-field interaction" means a very short distance interaction using scanning-probe techniques, e.g. quasi- contact or evanescent contact between head and record carrier. [7]
  3. Attention is drawn to the Notes following the titles of class B81 and subclass B81B relating to "micro-structural devices" and "micro-structural systems". [7]
 G11B
Subclass index
RECORDING OF ONE TYPE ASSOCIATED WITH REPRODUCING MEANS OF THE SAME TYPE
Of mechanical type 3/00
Of magnetical type 5/00
Of optical type 7/00
Of another type 9/00
RECORDING OF ONE TYPE AND ASSOCIATED REPRODUCING MEANS OF DIFFERENT TYPE 11/00
SIMULTANEOUS OR SELECTIVE RECORDING OF DIFFERENT TYPES; ASSOCIATED SIMULTANEOUS OR SELECTIVE REPRODUCING MEANS 13/00
SIGNAL PROCESSING NOT SPECIFIC TO THE METHOD OF RECORDING OR REPRODUCING 20/00
APPARATUS CHARACTERISED BY THE SHAPE OF THE RECORD CARRIER 25/00
DETAILS; GENERAL FEATURES
Starting, stopping, driving 15/00, 19/00
Guiding 17/00
HEADS; RECORD CARRIERS 21/00; 23/00
ASSOCIATED WORKING WITH OTHER APPARATUS 31/00
EDITING, INDEXING, SYNCHRONISING, MONITORING 27/00
MANUFACTURING 3/00, 5/84, 7/26
OTHER CONSTRUCTIONAL PARTS, DETAILS OR ACCESSORIES 33/00
P:50 G11B 3/00
Recording by mechanical cutting, deforming or pressing, e.g. of grooves or pits; Reproducing by mechanical sensing; Record carriers therefor (G11B 11/00 takes precedence; recording by cutting or deforming using laser beam G11B 7/00, using electron beam G11B 9/00; processes involving a single technical art, in general, and for which provision exists elsewhere, see the relevant places, e.g. B29D 17/00)
P:40 G11B 5/00
Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor (G11B 11/00 takes precedence)  [4]
 G11B 5/004 - 
G11B 5/012

Note(s)

Groups G11B 5/02-G11B 5/86 take precedence over groups G11B 5/004-G11B 5/012[2]

 G11B 5/004
·  Recording on, or reproducing or erasing from, magnetic drums (G11B 19/00 takes precedence)  [2]
 G11B 5/008
·  Recording on, or reproducing or erasing from, magnetic tapes or wires (G11B 15/00 takes precedence)  [2]
 G11B 5/012
·  Recording on, or reproducing or erasing from, magnetic discs (G11B 17/00, G11B 19/00 take precedence)  [2]
 G11B 5/02
·  Recording, reproducing, or erasing methods; Read, write, or erase circuits therefor (timing or synchronising arrangements G11B 27/10)  [2]
 G11B 5/024
·  ·  Erasing  [4]
 G11B 5/027
·  ·  Analogue recording  [2]
 G11B 5/03
·  ·  ·  Biasing  [4]
 G11B 5/035
·  ·  ·  Equalising  [4]
 G11B 5/09
·  ·  Digital recording  [2]
 G11B 5/10
·  Structure or manufacture of housings or shields for heads  [4]
 G11B 5/127
·  Structure or manufacture of heads, e.g. inductive  [4]
 G11B 5/133
·  ·  with cores composed of particles, e.g. with dust cores, with ferrite cores  [4]
 G11B 5/147
·  ·  with cores being composed of metal sheets, i.e. laminated cores  [4]
 G11B 5/17
·  ·  Construction or disposition of windings  [4]
 G11B 5/187
·  ·  Structure or manufacture of the surface of the head in physical contact with, or immediately adjacent to, the recording medium; Pole pieces; Gap features (G11B 5/265, G11B 5/31 take precedence)  [4]
 G11B 5/193
·  ·  ·  the pole pieces being ferrite  [4]
 G11B 5/21
·  ·  ·  the pole pieces being of ferrous sheet metal  [4]
 G11B 5/23
·  ·  ·  Gap features  [4]
 G11B 5/235
·  ·  ·  ·  Selection of material for gap filler  [4]
 G11B 5/245
·  ·  ·  comprising means for controlling the reluctance of the magnetic circuit (G11B 5/255 takes precedence)  [4]
 G11B 5/255
·  ·  ·  comprising means for protection against wear  [4]
 G11B 5/265
·  ·  Structure or manufacture of a head with more than one gap for erasing, recording or reproducing on the same track (G11B 5/33 takes precedence)  [4]
 G11B 5/29
·  ·  Structure or manufacture of unitary devices formed of plural heads for more than one track  [4]
 G11B 5/31
·  ·  using thin film (G11B 5/33 takes precedence)  [4]
 G11B 5/325
·  ·  Erasing heads using permanent magnets (general details therefor G11B 5/133-G11B 5/255)  [4]
 G11B 5/33
·  ·  Structure or manufacture of flux-sensitive heads (general details therefor G11B 5/133-G11B 5/255)  [4]
 G11B 5/39
·  ·  ·  using magneto-resistive devices  [4]
 G11B 5/40
·  Protective measures on heads, e.g. against excessive temperature (G11B 5/31 takes precedence; protection against wear G11B 5/255)  [4]
 G11B 5/41
·  Cleaning of heads  [2]
 G11B 5/455
·  Arrangements for functional testing of heads; Measuring arrangements for heads (measuring electric or magnetic properties G01R)  [4]
 G11B 5/465
·  Arrangements for demagnetisation of heads (demagnetisation in general H01F 13/00)  [4]
 G11B 5/48
·  Disposition or mounting of heads relative to record carriers
 G11B 5/49
·  ·  Fixed mountings  [2]
 G11B 5/50
·  ·  Interchangeable mountings, e.g. for replacement of head without readjustment
 G11B 5/52
·  ·  with simultaneous movement of head and record carrier, e.g. rotation of head (G11B 5/588 takes precedence)  [4]
 G11B 5/53
·  ·  ·  Disposition or mounting of heads on rotating support  [4]
 G11B 5/54
·  ·  with provision for moving the head into, or out of, its operative position or across tracks  [2]
 G11B 5/55
·  ·  ·  Track change, selection, or acquisition by displacement of the head  [2]
 G11B 5/56
·  ·  with provision for moving the head for the purpose of adjusting the position of the head relative to the record carrier, e.g. manual adjustment for azimuth correction or track centering (G11B 5/54, G11B 5/58 take precedence)  [2]
 G11B 5/58
·  ·  with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following  [2]
 G11B 5/584
·  ·  ·  for track following on tapes  [4]
 G11B 5/588
·  ·  ·  ·  by controlling the position of the rotating heads (by controlling the speed of the record carrier G11B 15/467; by controlling the speed of the rotating heads G11B 15/473)  [4]
 G11B 5/592
·  ·  ·  ·  ·  using bimorph elements supporting the heads  [4]
 G11B 5/596
·  ·  ·  for track following on discs  [4]
 G11B 5/60
·  ·  ·  Fluid-dynamic spacing of heads from record carriers
 G11B 5/62
·  Record carriers characterised by the selection of the material (selection of magnetic materials in general H01F 1/00; thin magnetic films H01F 10/00)
 G11B 5/62

Note(s)

This group does not cover compositions, materials or processes, per se, which are covered by the relevant subclasses of section B or C.  [4]

 G11B 5/64
·  ·  comprising only the magnetic material without bonding agent
 G11B 5/66
·  ·  ·  the record carriers consisting of several layers
 G11B 5/68
·  ·  comprising one or more layers of magnetisable particles homogeneously mixed with a bonding agent (layered products in general B32B)
 G11B 5/70
·  ·  ·  on a base layer (base layers per se G11B 5/62)  [1,7]
 G11B 5/702
·  ·  ·  ·  characterised by the bonding agent  [4]
 G11B 5/706
·  ·  ·  ·  characterised by the composition of the magnetic material  [4]
 G11B 5/708
·  ·  ·  ·  characterised by the addition of non-magnetic particles to the magnetic layer  [4]
 G11B 5/71
·  ·  ·  ·  characterised by the lubricant  [4]
 G11B 5/712
·  ·  ·  ·  characterised by the surface treatment or coating of magnetic particles  [4]
 G11B 5/716
·  ·  ·  ·  characterised by two or more magnetic layers  [4]
 G11B 5/72
·  ·  Protective coatings, e.g. anti-static
 G11B 5/74
·  Record carriers characterised by the form, e.g. sheet shaped to wrap around a drum
 G11B 5/80
·  ·  Card carriers
 G11B 5/82
·  ·  Disc carriers
 G11B 5/84
·  Processes or apparatus specially adapted for manufacturing record carriers (processes involving a single technical art, in general, and for which provision exists elsewhere, see the relevant places, e.g. B29, C23, C25D; apparatus or processes for applying homogeneous magnetic films to substrates in general H01F 41/14)
 G11B 5/842
·  ·  Coating a support with a liquid magnetic dispersion  [4]
 G11B 5/845
·  ·  ·  in a magnetic field  [4]
 G11B 5/848
·  ·  Coating a support with a magnetic layer by extrusion  [4]
 G11B 5/85
·  ·  Coating a support with a magnetic layer by vapour deposition  [4]
 G11B 5/852
·  ·  Orientation in a magnetic field (G11B 5/845 takes precedence)  [4]
 G11B 5/855
·  ·  Coating only part of a support with a magnetic layer  [4]
 G11B 5/858
·  ·  Producing a magnetic layer by electro-plating or electroless plating  [4]
 G11B 5/86
·  Re-recording, i.e. transcribing information from one magnetisable record carrier on to one or more similar or dissimilar record carriers
P:30 G11B 7/00
Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation, reproducing using an optical beam at lower power; Record carriers therefor (G11B 11/00, G11B 13/00 take precedence)  [4,7]
 G11B 7/007
·  Arrangement of the information on the record carrier, e.g. form of tracks  [4]
 G11B 7/013
·  ·  for discrete information, i.e. where each information unit is stored in a distinct location  [4]
 G11B 7/08
·  Disposition or mounting of heads or light sources relatively to record carriers
 G11B 7/085
·  ·  with provision for moving the light beam into, or out of, its operative position (modulating by information signals G11B 7/12; controlling the position or direction of light beams, i.e. deflection, G02F 1/29)  [4]
 G11B 7/09
·  ·  with 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, e.g. to compensate for surface irregularities of the latter or for track following  [4]
 G11B 7/095
·  ·  ·  specially adapted for discs, e.g. for compensation of eccentricity or wobble  [4]
 G11B 7/10
·  ·  Interchangeable mountings, e.g. for replacement of head without readjustment
 G11B 7/12
·  Heads
 G11B 7/125
·  ·  Optical beam sources therefor (light-emitting diodes H01L 33/00; semiconductor lasers H01S 5/00); Modulators, e.g. means for controlling the size or intensity of the optical spot or of the optical trace (electro-, magneto-, or acousto-optical modulators G02F 1/00; optical diaphragms G03B 9/02)  [4]
 G11B 7/13
·  ·  Optical detectors therefor (optical detectors in general G01J; demodulating light, transferring the modulation of modulated light, frequency changing of light G02F 2/00)  [4]
 G11B 7/135
·  ·  Means for guiding the beam from source to record carrier or from record carrier to detector  [4]
 G11B 7/14
·  ·  adapted to record on, or to reproduce from, more than one track simultaneously (G11B 7/20 takes precedence)
 G11B 7/16
·  ·  using filters, e.g. colour filter
 G11B 7/18
·  ·  using optical slits
 G11B 7/20
·  ·  Dual-recording arrangements, i.e. in which the information is recorded in two different forms simultaneously on the same or related tracks, e.g. recording instantaneous and mean values (sound-recording combined with cinematography G03C)
 G11B 7/22
·  ·  Apparatus or processes specially adapted for the manufacture of heads, e.g. assembly
 G11B 7/24
·  Record carriers characterised by the selection of the material or by the structure or form (characterised by the arrangement of information on the carrier G11B 7/007; photosensitive materials per se G03C)  [4]
 G11B 7/26
·  ·  Apparatus or processes specially adapted for the manufacture of record carriers (processes involving a single technical art and for which provision exists elsewhere, see the relevant class, e.g. B29, G03)
 G11B 7/28
·  Re-recording, i.e. transcribing information from one optical record carrier on to one or more similar or dissimilar record carriers using optical sensing means
P:60 G11B 9/00
Recording or reproducing using a method or means not covered by one of the main groups G11B 3/00-G11B 7/00; Record carriers therefor (G11B 11/00 takes precedence)  [4]
P:20 G11B 11/00
Recording on, or reproducing from, the same record carrier wherein for these two operations the methods or means are covered by different main groups of groups G11B 3/00-G11B 7/00 or by different subgroups of group G11B 9/00; Record carriers therefor
P:10 G11B 13/00
Recording simultaneously or selectively by methods or means covered by different main groups; Record carriers therefor; Reproducing simultaneously or selectively therefrom  [1,7]
 G11B 13/00

Note(s)

  1. This group covers arrangements in which there are at least two recordings of information involving two different methods or means or two different physical properties, at the same or different locations, on the same record carrier, the recordings being made or reproduced simultaneously or selectively. [7]
  2. Where such combinations of means are used for changing only one main property, classification is only made in one of the relevant main groups G11B 3/00, G11B 5/00, G11B 7/00, G11B 9/00 or G11B 11/00[7]
P:70 G11B 15/00
Driving, starting or stopping record carriers of filamentary or web form; Driving both such record carriers and heads; Guiding such record carriers or containers therefor; Control thereof; Control of operating function (driving or guiding heads G11B 3/00-G11B 7/00, G11B 21/00)  [2]
 G11B 15/02
·  Control of operating function, e.g. switching from recording to reproducing
 G11B 15/03
·  ·  by using counters  [4]
 G11B 15/04
·  ·  Preventing, inhibiting, or warning against accidental erasing or double recording (G11B 15/05 takes precedence)  [4]
 G11B 15/05
·  ·  by sensing features present on, or derived from, record carrier or container (G11B 15/16 takes precedence)  [4]
 G11B 15/087
·  ·  ·  by sensing recorded signals  [4]
 G11B 15/10
·  ·  Manually-operated control; Solenoid-operated control
 G11B 15/12
·  ·  Masking of heads; Selecting or switching of heads between operative and inoperative functions; Masking of beams, e.g. of light beams
 G11B 15/16
·  ·  by sensing presence, absence or position of record carrier or container
 G11B 15/18
·  Driving; Starting; Stopping; Arrangements for control or regulation thereof
 G11B 15/26
·  ·  Driving record carriers by members acting directly or indirectly thereon
 G11B 15/28
·  ·  ·  through rollers driving by frictional contact with the record carrier, e.g. capstan; Multiple arrangements of capstans or drums coupled to means for controlling the speed of the drive; Multiple capstan systems alternately engageable with record carrier to provide reversal
 G11B 15/43
·  ·  Control or regulation of mechanical tension of record carrier, e.g. tape tension
 G11B 15/44
·  ·  Speed-changing arrangements; Reversing arrangements; Drive-transfer means therefor
 G11B 15/46
·  ·  Controlling, regulating, or indicating speed
 G11B 15/467
·  ·  ·  in arrangements for recording or reproducing wherein both record carriers and heads are driven  [4]
 G11B 15/473
·  ·  ·  ·  by controlling the speed of the heads  [4]
 G11B 15/48
·  ·  ·  Starting; Accelerating; Decelerating; Arrangements preventing malfunction during drive change
 G11B 15/60
·  Guiding record carriers (guiding devices structurally associated with magazines or cassettes G11B 23/04)  [4]
 G11B 15/61
·  ·  on drum, e.g. on drum containing rotating heads  [4]
 G11B 15/62
·  ·  Maintaining desired spacing between record carrier and head
 G11B 15/66
·  ·  Threading; Loading; Automatic self-loading
 G11B 15/665
·  ·  ·  by extracting loop of record carrier from container  [4]
 G11B 15/675
·  Guiding containers  [4]
 G11B 15/68
·  ·  Automatic cassette-changing arrangements  [2]
P:90 G11B 17/00
Guiding record carriers not specifically of filamentary or web form, or of supports therefor (guiding cards or sheets G06K 13/00)
 G11B 17/02
·  Details
 G11B 17/022
·  ·  Positioning or locking of single discs  [4]
 G11B 17/028
·  ·  ·  of discs rotating during transducing operation  [4]
 G11B 17/03
·  ·  ·  ·  in containers or trays  [4]
 G11B 17/032
·  ·  ·  ·  Positioning by moving the door or the cover  [4]
 G11B 17/035
·  ·  ·  ·  Positioning by moving the loading station  [4]
 G11B 17/04
·  ·  Feeding or guiding single record carrier to or from transducing unit
 G11B 17/22
·  from random-access magazine of disc records
 G11B 17/24 - 
G11B 17/28

Note(s)

Group G11B 17/30 takes precedence over groups G11B 17/24-G11B 17/28.

 G11B 17/24
·  ·  the magazine having a toroidal or part-toroidal shape
 G11B 17/26
·  ·  the magazine having a cylindrical shape with vertical axis
 G11B 17/28
·  ·  the magazine having a cylindrical shape with horizontal axis
 G11B 17/30
·  ·  wherein the playing unit is moved accordingly to the location of the selected record
 G11B 17/32
·  Maintaining desired spacing between record carrier and head, e.g. by fluid-dynamic spacing  [2]
P:80 G11B 19/00
Driving, starting, stopping record carriers not specifically of filamentary or web form, or of supports therefor; Control thereof; Control of operating function (guiding such record carriers G11B 17/00)
 G11B 19/02
·  Control of operating function, e.g. switching from recording to reproducing  [4]
 G11B 19/04
·  ·  Arrangements for preventing, inhibiting, or warning against, double recording on the same blank, or against other recording or reproducing malfunctions
 G11B 19/06
·  ·  by counting or timing of machine operations
 G11B 19/08
·  ·  by using devices external to the driving mechanisms, e.g. coin-freed switch (coin actuated mechanisms G07F 5/00)  [4]
 G11B 19/10
·  ·  by sensing presence or absence of record in accessible stored position or on turntable
 G11B 19/12
·  ·  by sensing distinguishing features of records, e.g. diameter
 G11B 19/14
·  ·  by sensing movement or position of head, e.g. means moving in correspondence with head movements
 G11B 19/16
·  ·  Manual control
 G11B 19/20
·  Driving; Starting; Stopping; Control thereof  [4]
 G11B 19/22
·  ·  Brakes other than speed-regulating brakes (brake constructions in general F16D)
 G11B 19/24
·  ·  Arrangements for providing constant relative speed between record carrier and head
 G11B 19/26
·  ·  Speed-changing arrangements; Reversing arrangements; Drive-transfer means therefor  [4]
 G11B 19/28
·  ·  Speed controlling, regulating, or indicating (G11B 19/24 takes precedence; speedometers or tachometers G01P)
P:100 G11B 20/00
Signal processing not specific to the method of recording or reproducing; Circuits therefor  [4]
 G11B 20/02
·  Analogue recording or reproducing  [4]
 G11B 20/04
·  ·  Direct recording or reproducing  [4]
 G11B 20/06
·  ·  Angle-modulation recording or reproducing (angle-modulation H03C; demodulation of angle-modulated oscillations H03D)  [4]
 G11B 20/08
·  ·  Pulse-modulation recording or reproducing (pulse-code-modulation recording G11B 20/10; pulse modulation or pulse demodulation H03K)  [4]
 G11B 20/10
·  Digital recording or reproducing (electrical digital data processing G06F; speech analysis-synthesis techniques for redundancy reduction G10L 19/00; transmission of digital information H04L)  [4]
 G11B 20/12
·  ·  Formatting, e.g. arrangement of data block or words on the record carriers  [4]
 G11B 20/14
·  ·  using self-clocking codes  [4]
 G11B 20/16
·  ·  using non self-clocking codes, i.e. the clock signals being either recorded in a separate clocking track or in a combination of several information tracks  [4]
 G11B 20/18
·  ·  Error detection or correction; Testing  [4]
 G11B 20/20
·  for correction of skew for multitrack recording  [4]
 G11B 20/22
·  for reducing distortions  [4]
 G11B 20/24
·  for reducing noise  [4]
P:110 G11B 21/00
Head arrangements not specific to the method of recording or reproducing
 G11B 21/02
·  Driving or moving of heads
 G11B 21/03
·  ·  for correcting time base error  [4]
 G11B 21/04
·  ·  Automatic feed mechanism producing a transducing traverse of the head in a direction which cuts across the direction of travel of the recording medium, e.g. helical scan
 G11B 21/08
·  ·  Track changing or selecting (G11B 21/12 takes precedence)
 G11B 21/10
·  ·  Track finding or aligning by moving the head
 G11B 21/12
·  ·  Raising and lowering; Back-spacing or forward-spacing along track; Returning to starting position
 G11B 21/16
·  Supporting the heads; Supporting the sockets for plug-in heads
 G11B 21/20
·  ·  while the head is in operative position but stationary or permitting minor movements to follow irregularities in surface of record carrier
 G11B 21/21
·  ·  ·  with provision for maintaining desired spacing of head from record carrier, e.g. fluid-dynamic spacing, slider  [4]
 G11B 21/22
·  ·  while the head is out of operative position
P:130 G11B 23/00
Record carriers not specific to the method of recording or reproducing; Accessories, e.g. containers, specially adapted for co-operation with the recording or reproducing apparatus  [4]
 G11B 23/00

Note(s)

In group G11B 23/00, recording or reproducing apparatus does not include the record carriers.  [5]

 G11B 23/02
·  Containers; Storing means (cabinets, cases, stands, modified to store record carriers G11B 33/04; storing webs, tapes or filamentary material in general B65H 75/00)  [4]
 G11B 23/023
·  ·  Containers for magazines or cassettes  [4]
 G11B 23/03
·  ·  Containers for flat record carriers  [4]
 G11B 23/033
·  ·  ·  for flexible discs  [4]
 G11B 23/04
·  ·  Magazines; Cassettes (G11B 23/12 takes precedence)
 G11B 23/08
·  ·  ·  for housing webs or filaments having two distinct ends
 G11B 23/087
·  ·  ·  ·  using two different reels or cores  [4]
 G11B 23/093
·  ·  ·  ·  ·  the reels or cores being coaxial  [4]
 G11B 23/113
·  ·  Apparatus or processes specially adapted for the manufacture of magazines or cassettes  [4]
 G11B 23/12
·  ·  Bins for random storage of webs or filaments
 G11B 23/14
·  providing ability to repeat location, e.g. using sprocket holes
 G11B 23/16
·  Record carriers with single track for recording at spaced intervals along the track thereof, e.g. for speech or language training
 G11B 23/18
·  Record carriers with multiple tracks, e.g. with complementary and partial tracks such as paired "stereo" tracks
 G11B 23/20
·  with provision for splicing to provide permanent or temporary connections
 G11B 23/28
·  indicating prior or unauthorised use
 G11B 23/30
·  with provision for auxiliary signals (sensing such signals G11B 15/05)
 G11B 23/38
·  Visual features other than those contained in record tracks or represented by sprocket holes
 G11B 23/50
·  Reconditioning of record carriers; Cleaning of record carriers (G11B 3/00 takes precedence)  [2]
P:120 G11B 25/00
Apparatus characterised by the shape of record carrier employed but not specific to the method of recording or reproducing (individual parts of apparatus G11B 3/00-G11B 23/00, G11B 33/00)  [4]
 G11B 25/04
·  using flat record carriers, e.g. disc, card
P:140 G11B 27/00
Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel  [2,4]
 G11B 27/02
·  Editing, e.g. varying the order of information signals recorded on, or reproduced from, record carriers (arrangements for sorting or merging computer data on continuous record carriers G06F 7/22; mixing of video signals H04N 5/265)  [5]
 G11B 27/022
·  ·  Electronic editing of analogue information signals, e.g. audio or video signals  [5]
 G11B 27/031
·  ·  Electronic editing of digitised analogue information signals, e.g. audio or video signals  [5]
 G11B 27/10
·  Indexing; Addressing; Timing or synchronising; Measuring tape travel  [2]
 G11B 27/11
·  ·  by using information not detectable on the record carrier  [4]
 G11B 27/19
·  ·  by using information detectable on the record carrier  [4]
 G11B 27/28
·  ·  ·  by using information signals recorded by the same method as the main recording
 G11B 27/30
·  ·  ·  ·  on the same track as the main recording
 G11B 27/32
·  ·  ·  ·  on separate auxiliary tracks of the same or an auxiliary record carrier
 G11B 27/34
·  ·  Indicating arrangements
 G11B 27/36
·  Monitoring, i.e. supervising the progress of recording or reproducing
P:0 G11B 31/00
Arrangements for the associated working of recording or reproducing apparatus with related apparatus (with cameras or projectors G03B 31/00; substation equipment for recording telephonic conversations or messages for absent subscribers H04M 1/65)  [1,7]
 G11B 31/02
·  with automatic musical instruments
P:150 G11B 33/00
Constructional parts, details or accessories not provided for in the other groups of this subclass (containers, packaging elements or packages specially adapted for record carriers B65D 85/00)  [4]
 G11B 33/02
·  Cabinets; Cases; Stands; Disposition of apparatus therein or thereon (furniture aspects A47B, e.g. A47B 81/00)  [4]
 G11B 33/04
·  ·  modified to store record carriers  [4]
 G11B 33/06
·  ·  combined with other apparatus having a different main function  [4]
 G11B 33/08
·  ·  Insulation or absorption of undesired vibrations or sounds  [4]
 G11B 33/12
·  Disposition of constructional parts in the apparatus, e.g. of power supply, of modules  [4]
 G11B 33/14
·  Reducing influence of physical parameters, e.g. temperature change, moisture, dust  [4]