IPC 2013 : G : SECTION G — PHYSICS.

IPC2013 > G[s] > SECTION G — PHYSICS.
Notes[n] G:
  • 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 G01 and "control" and "regulation" in class 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 (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.
G01 MEASURING; TESTING.
Notes[t] G01 - G12: INSTRUMENTS
Notes[n] G01:
  • This class covers , in addition to "true" measuring instruments, other indicating or recording devices of analogous construction, and also signalling or control devices insofar as they are concerned with measurement (as defined in Note 2 below) and are not specially adapted to the particular purpose of signalling or control.
  • In this class, the following term is used with the meaning indicated:
    • "measuring" is used to cover considerably more than its primary or basic meaning. In this primary sense, it means finding a numerical expression of the value of a variable in relation to a unit or datum or to another variable of the same nature, e.g. expressing a length in terms of another length as in measuring a length with a scale; the value may be obtained directly (as just suggested) or by measuring some other variable of which the value can be related to the value of the required variable, as in measuring a change in temperature by measuring a resultant change in the length of a column of mercury. However, since the same device or instrument may, instead of giving an immediate indication, be used to produce a record or to initiate a signal to produce an indication or control effect, or may be used in combination with other devices or instruments to give a conjoint result from measurement of two or more variables of the same or different kinds, it is necessary to interpret "measuring" as including also any operation that would make it possible to obtain such a numerical expression by the additional use of some way of converting a value into figures. Thus the expression in figures may be actually made by a digital presentation or by reading a scale, or an indication of it may be given without the use of figures, e.g. by some perceptible feature (variable) of the entity (e.g. object, substance, beam of light) of which the variable being measured is a property or condition or by an analogue of such a feature (e.g. the corresponding position of a member without any scale, a corresponding voltage generated in some way). In many cases there is no such value indication but only an indication of difference or equality in relation to a standard or datum (of which the value may or may not be known in figures); the standard or datum may be the value of another variable of the same nature but of a different entity (e.g. a standard measure) or of the same entity at a different time.
      • In its simplest form, measurement may give merely an indication of presence or absence of a certain condition or quality, e.g. movement (in any direction or in a particular direction), or whether a variable exceeds a predetermined value.
  • Attention is drawn to the Notes following the titles of class B81 and subclass B81B relating to "micro-structural devices" and "micro-structural systems" and the Notes following the title of subclass B82B relating to "nano-structures".
  • Attention is drawn to the Notes following the title of section G, especially as regards the definition of the term "variable".
  • In many measuring arrangements, a first variable to be measured is transformed into a second, or further, variables. The second, or further, variables may be (a) a condition related to the first variable and produced in a member, or (b) a displacement of a member. Further transformation may be needed.  
    • When classifying such an arrangement, (i) the transformation step, or each transformation step, that is of interest is classified, or (ii) if interest lies only in the system as a whole, the first variable is classified in the appropriate place.  
    • This is particularly important where two or more conversions take place, for instance where a first variable, for example pressure, is transformed into a second variable, for example an optical property of a sensing body, and that second variable is expressed by means of a third variable, for example an electric effect. In such a case, the following classification places should be considered: the place for the transformation of the first variable, that for sensing the condition caused by that variable, subclass G01D for expression of the measurement, and finally the place for the overall system, if any.  
  • The measurement of change in the value of a physical property is classified in the same subclass as the measurement of that physical property, e.g. measurement of expansion of length is classified in subclass G01B .
G02 OPTICS.
Notes[n] G02:
  • In this class, the following expression is used with the meaning indicated:
    • "optical" applies not only to visible light but also to ultra-violet or infra-red radiations.  
G03 PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY.
Notes[n] G03:
  • This class does not cover reproduction of pictures or patterns by scanning and converting into electrical signals, which is covered by subclass H04N .  
  • In this class, the following terms are used with the meaning indicated:
    • "records" means photographs or any other kind of latent, directly-visible or permanent storage of pictorial information, which consist of an imagewise distribution of a quantity, e.g. an electric charge pattern, recorded on a carrier member;
    • "optical" applies not only to visible light but also to ultra-violet or infra-red radiations.    
G04 HOROLOGY.
G05 CONTROLLING; REGULATING.
Notes[n] G05:
  • This class covers methods, systems, and apparatus for controlling, in general.
  • In this class, the following terms or expressions are used with the meanings indicated:
    • "controlling" means influencing a variable in any way, e.g. changing its direction or its value (including changing it to or from zero), maintaining it constant, limiting its range of variation;
    • "regulation" means maintaining a variable automatically at a desired value or within a desired range of values. The desired value or range may be fixed, or manually varied, or may vary with time according to a predetermined "programme" or according to variation of another variable. Regulation is a form of control;
    • "automatic control" is often used in the art as a synonym for "regulation".
  • Attention is drawn to the Notes following the title of section G, especially as regards the definition of the term "variable".
G06 COMPUTING; CALCULATING; COUNTING.
Notes[n] G06:
  • This class covers :
    • simulators which are concerned with the mathematics of computing the existing or anticipated conditions within the real device or system;
    • simulators which demonstrate, by means involving computing, the function of apparatus or of a system, if no provision exists elsewhere;
    • image data processing or generation.
  • This class does not cover :
    • combinations of writing implements with computing devices, which are covered by group B43K 29/08 ;   
    • control functions derived from simulators, in general, which are covered by class G05, although such functions may be covered by the subclass of this class for the device controlled;
    • measurement or analysis of an individual variable to serve as an input to a simulator, which is covered by class G01;
    • simulators regarded as teaching or training devices which is the case if they give perceptible sensations having a likeness to the sensations a student would experience in reality in response to actions taken by him. Such simulators are covered by class G09;
    • components of simulators, if identical with real devices or machines, which are covered by the relevant subclass for these devices or machines (and not by class G09 ).
  • In this class, the following terms or expressions are used with the meanings indicated:
    • "data" is used as the synonym of "information". Therefore, the term "information" is not used in subclasses G06C, G06F or G06Q;
    • "calculating or computing" includes, inter alia , operations on numerical values and on data expressed in numerical form. Of these terms "computing" is used throughout the class;
    • "computation" is derived from this interpretation of "computing". In the French language the term "calcul" will serve for either term;
    • "simulator" is a device which may use the same time scale as the real device or operate on an expanded or compressed time scale. In interpreting this term models of real devices to reduced or expanded scales are not regarded as simulators;
    • "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 relative to the recorded information.
  • Attention is drawn to the Notes following the title of section G, especially as regards the definition of the term "variable".
G07 CHECKING-DEVICES.
G08 SIGNALLING.
G09 EDUCATING; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS.
G10 MUSICAL INSTRUMENTS; ACOUSTICS.
Notes[n] G10:
  • This class covers all sound-emitting devices, in general, whether or not they may be considered as being musical.
  • In this class, the following expression is used with the meaning indicated:
    • "musical instrument" does not exclude devices emitting a single sound signal.
  • The following Class Index is given in place of subclass indexes, to show the grouping of the elaborations belonging to different subclasses, under the following three fundamental types:
    • wind instruments;
    • string instruments;
    • percussion instruments,
    which relate clearly to the majority of instruments.
  • There are of course some instruments of which the principle of operation belongs less clearly to one of the three types mentioned in Note (3). They correspond to groups G10D 17/00 or G10K 7/00, G10K 9/00 or G10K 15/04, all the other groups normally finding a definite place.
G11 INFORMATION STORAGE.
G12 INSTRUMENT DETAILS.
G21 NUCLEAR PHYSICS; NUCLEAR ENGINEERING.
Notes[t] G21: NUCLEONICS
G99 SUBJECT MATTER NOT OTHERWISE PROVIDED FOR IN THIS SECTION.