This sub-class deals with the recording and 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.
This sub-class includes
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 sub-class:
The term "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.
A record carrier is understood to be 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.
This sub-class deals with 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.
In this sub-class, a storage element is provided with means for writing-in and reading-out at least one item of information. Elements not adapted for storage and not provided with such means are classified in the appropriate sub-class, e.g. of Fulltext... Hierarchy... Expanded...H01, Fulltext... Hierarchy... Expanded...H03K.