H
SECTION H — ELECTRICITY
 H04
ELECTRIC COMMUNICATION TECHNIQUE
 H04

Note(s)

This class covers electrical communication systems with propagation paths employing light (optical communication), infra-red, ultrasonic, sonic, or infrasonic waves.

 H04B
TRANSMISSION (coding, decoding or code conversion, in general H03M; broadcast communication H04H; multiplex systems H04J; secret communication H04K; transmission of digital information per se H04L)
 H04B

Note(s)

This subclass covers the transmission of information-carrying signals, the transmission being independent of the nature of the information, and includes monitoring and testing arrangements and the suppression and limitation of noise and interference.


 H04H
BROADCAST COMMUNICATION (transmission in general H04B; multiplex communication H04J)
 H04H

Note(s)

This subclass covers:

  • distribution of entertainment or informative matter simultaneously to a number of receiving stations over transmission lines or over radio waves;
  • recording of the use made of the broadcast service.


 H04J
MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L 5/00; systems for transmitting television signals simultaneously or sequentially H04N 7/08; in exchanges H04Q 11/00; stereophonic systems H04S)
 H04J

Note(s)

This subclass covers:

  • circuits or apparatus for combining or dividing signals for the purpose of transmitting them simultaneously or sequentially over the same transmission path;
  • monitoring arrangements therefor.


 H04K
SECRET COMMUNICATION; JAMMING OF COMMUNICATION
 H04K

Note(s)

In this subclass, the following expression is used with the meaning indicated:

  • "secret communication" includes secret line and radiation transmission systems, i.e. those in which apparatus at the transmitting station modifies the signal in such a way that the information cannot be intelligibly received without corresponding modifying apparatus at the receiving station.


 H04L
TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (typewriters B41J; order telegraphs, fire or police telegraphs G08B; visual telegraphy G08B, G08C; teleautographic systems G08C; coding, decoding or code conversion, in general H03M; arrangements common to telegraphic and telephonic communication H04M; selecting H04Q)
 H04L

Note(s)

This subclass covers transmission of signals having been supplied in digital form and includes data transmission, telegraphic communication, or methods or arrangements for monitoring.


 H04M
TELEPHONIC COMMUNICATION (counting mechanisms G06M; circuits for controlling other apparatus via a telephone cable and not involving telephone switching apparatus G08; reels or other take-up devices for cords H02G 11/00; multiplex transmission between switching centres H04J; selecting arrangements H04Q; transducers H04R)
 H04M

Note(s)

  1. This subclass covers:
    • telephonic communication systems combined with other electrical systems;
    • testing arrangements peculiar to telephonic communication systems.
  2. In this subclass, the following terms or expressions are used with the meanings indicated:
    • "subscriber" is a general term for terminal equipment, e.g. telephone for public use;
    • "substation" means a subscriber or monitoring equipment which may connect a single subscriber to a line without choice as to subscriber;
    • "satellite" is a type of exchange the operation of which depends upon control signals received from a supervisory exchange;
    • "switching centres" includes exchanges and satellites.

 H04N
PICTORIAL COMMUNICATION, e.g. TELEVISION (measuring, testing G01; systems for autographic writing, e.g. writing telegraphy, which involve following an outline G08; information storage based on relative movement between record carrier and transducer G11B; coding, decoding or code conversion, in general H03M; broadcast distribution or the recording of use made thereof H04H)
 H04N

Note(s)

  1. This subclass covers:
    • transmission of pictures or their transient or permanent reproduction either locally or remotely, by methods involving both the following steps:

      step (a):
      the scanning of a picture, i.e. resolving the whole picture-containing area into individual picture-elements and the derivation of picture-representative electric signals related thereto, simultaneously or in sequence;

      step (b):
      the reproduction of the whole picture-containing area by the reproduction of individual picture-elements into which the picture is resolved by means of picture-representative electric signals derived therefrom, simultaneously or in sequence;

    • (in group H04N 1/00) systems for the transmission or the reproduction of arbitrarily composed pictures or patterns in which the local light variations composing a picture are not subject to variation with time, e.g. documents (both written and printed), maps, charts, photographs (other than cinematograph films);
    • circuits specially designed for dealing with pictorial communication signals, e.g. television signals, as distinct from merely signals of a particular frequency range.
  2. This subclass does not cover:
  3. In this subclass, the following expression is used with the meaning indicated:
    • "television systems" means those systems for the transmission and reproduction of arbitrarily composed pictures in which the local light variations composing a picture may change with time, e.g. natural "live" scenes, recordings of such scenes such as cinematograph films.

 H04Q
SELECTING (switches, relays, selectors H01H; electronic switches H03K 17/00)
 H04Q

Note(s)

  1. This subclass covers:
    • methods, circuits, or apparatus for establishing selectively a connection between a desired number of stations (normally two), or between a main station and a desired number of substations (normally one) for the purpose of transferring information via this connection after it has been established;
    • selective calling arrangements over connections already established. In either case, the connection may be by means of electric conductors or electromagnetic waves.
  2. In this subclass, the following terms or expressions are used with the meanings indicated:
    • "subscriber" is ageneral term for terminal equipment, e.g. telephone for public use;
    • "substation" means a subscriber or monitoring equipment which may connect a single subscriber to a line without choice as to subscriber;
    • "satellite" is a kind of exchange the operation of which depends upon control signals received from a supervisory exchange;
    • "switching centres" includes exchanges and satellites.

 H04R
ELECTROMECHANICAL TRANSDUCERS (for performing mechanical work B06B; use of transducers as sensing elements for measuring G01, G04; construction or circuits of vibrators whose output is of frequency unrelated to that of the electric supply G10K; recording or reproducing heads incorporating transducers G11B; dynamo-electric machines H02K)
 H04R

Note(s)

This subclass covers:

  • instruments capable of converting sonic, ultrasonic, or infrasonic waves, or other mechanical vibrations into variations of electric current or voltage or vice versa;
  • instruments actuated by variations of electric current or voltage for cutting grooves in records;
  • circuits for the above-mentioned instruments;
  • deaf-aid sets;
  • public address systems;
  • monitoring or testing the above-mentioned equipment.


 H04S
STEREOPHONIC SYSTEMS (information storage on discs or tapes G11B; broadcast systems for the distribution of stereophonic information H04H 5/00; multiplex systems in general H04J)  [3]
 H04S

Note(s)

In this subclass, the following expression is used with the meaning indicated:

  • "stereophonic systems" covers quadraphonic or similar systems. [3]