|  | G |
SECTION G — PHYSICS

|  | G |
Note(s) 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). 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 Fulltext... Hierarchy... Expanded...G01 and "control" and "regulation" in class Fulltext... Hierarchy... Expanded...G05. 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 (Fulltext... Hierarchy... Expanded...G09), for enabling the result of a measurement to be known (Fulltext... Hierarchy... Expanded...G01), for signalling the information to a distant point or for giving information which has been signalled from a distant point (Fulltext... Hierarchy... Expanded...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 (Fulltext... Hierarchy... Expanded...G01L) or about some other condition linked to the pressure (another subclass of class Fulltext... Hierarchy... Expanded...G01, e.g., Fulltext... Hierarchy... Expanded...G01K for temperature), to make a record of the pressure or of its occurrence (Fulltext... Hierarchy... Expanded...G07C), to give an alarm (Fulltext... Hierarchy... Expanded...G08B), or to control another apparatus (Fulltext... Hierarchy... Expanded...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 Fulltext... Hierarchy... Expanded...G01D; photosensitive materials or processes for photographic purposes Fulltext... Hierarchy... Expanded...G03C; electrography, electrophotography, magnetography Fulltext... Hierarchy... Expanded...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, Fulltext... Hierarchy... Expanded...G06K; transferring data from one type of record carrier to another Fulltext... Hierarchy... Expanded...G06K 1/18; printing of data from record carriers Fulltext... Hierarchy... Expanded...G06K 3/00; arrangements for producing a permanent visual presentation of the output data Fulltext... Hierarchy... Expanded...G06K 15/00; arrangements or circuits for control of indicating devices using static means to present variable information Fulltext... Hierarchy... Expanded...G09G; details of scanning-probe apparatus, in general Fulltext... Hierarchy... Expanded...G12B 21/00; coding, decoding or code conversion, in general Fulltext... Hierarchy... Expanded...H03M; circuits for coupling output of reproducer to radio receiver Fulltext... Hierarchy... Expanded...H04B 1/20; television signal recording Fulltext... Hierarchy... Expanded...H04N 5/76, Fulltext... Hierarchy... Expanded...H04N 9/79; loudspeakers, microphones, gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor Fulltext... Hierarchy... Expanded...H04R)

|  | G11B |
Note(s) 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. 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] Attention is drawn to the Notes following the titles of class Fulltext... Hierarchy... Expanded...B81 and subclass Fulltext... Hierarchy... Expanded...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 | 3/70, 5/84, 7/26
OTHER CONSTRUCTIONAL PARTS, DETAILS OR ACCESSORIES | 33/00

|  | G11C |
STATIC STORES (information storage based on relative movement between record carrier and transducer Fulltext... Hierarchy... Expanded...G11B; semiconductor devices for storage Fulltext... Hierarchy... Expanded...H01L, e.g. Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...H01L 27/108-H01L 27/115; pulse technique in general Fulltext... Hierarchy... Expanded...H03K, e.g. electronic switches Fulltext... Hierarchy... Expanded...H03K 17/00)

|  | G11C |
Note(s) This subclass covers devices or arrangements for storage of digital or analogue information: in which no relative movement takes place between an information storage element and a transducer; which incorporate a selecting-device for writing-in or reading-out the information into or from the store. This subclass does not cover elements not adapted for storage and not provided with such means as referred to in Note (3) below, which elements are classified in the appropriate subclass, e.g. of Fulltext... Hierarchy... Expanded...H01, Fulltext... Hierarchy... Expanded...H03K. In this subclass, the following terms are used with the meaning indicated: [8] "storage element" is an element which can hold at least one item of information and is provided with means for writing-in or reading-out this information; [8] "memory" is a device, including storage elements, which can hold information to be extracted when desired. [8]

|  | G11C |
Subclass index
WRITING OR READING INFORMATION | 7/00
ADDRESS SELECTING | 8/00
DIGITAL STORES CHARACTERISED BY THE TYPE OF ELEMENT |
Electric, magnetic types; details thereof | 11/00; 5/00
Mechanical types | 23/00
Fluidic types | 25/00
Other types | 13/00
DIGITAL STORES CHARACTERISED BY BACK-UP MEANS | 14/00
ERASABLE PROGRAMMABLE READ-ONLY MEMORIES | 16/00
DIGITAL STORES CHARACTERISED BY INFORMATION DISPLACEMENT |
Shift; circulation | 19/00; 21/00
STORES CHARACTERISED BY FUNCTION |
Associative; analogue; for reading-out only | 15/00; 27/00; 17/00
CHECKING OF STORES | 29/00
SUBJECT MATTER NOT PROVIDED FOR IN OTHER GROUPS OF THIS SUBCLASS | 99/00