|  | H |
SECTION H — ELECTRICITY

|  | H04 |
ELECTRIC COMMUNICATION TECHNIQUE

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

|  | H04R |
Note(s) This sub-class deals with (a) instruments capable of converting sound, ultrasonic, or infrasonic waves, or other mechanical vibrations into variations of electric current or voltage or vice versa, (b) instruments actuated by variations of electric current or voltage for cutting grooves in records, (c) circuits for the instruments of (a) and (b), (d) deaf-aid sets, (e) public address systems, and (f) monitoring or testing the equipment of (a) to (e).

|  | H04R 1/00 |
Details of transducers covered by groups Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...H04R 9/00-H04R 23/00 (diaphragms Fulltext... Hierarchy... Expanded...H04R 7/00; mountings specially adapted for telephone equipment Fulltext... Hierarchy... Expanded...H04M 1/02)

|  | H04R 1/02 |
· | Casings; Cabinets; Mountings therein (Fulltext... Hierarchy... Expanded...H04R 1/28 takes precedence)

|  | H04R 1/04 |
· · | Structural association of microphone with electric circuitry therefor (in deaf-aid sets Fulltext... Hierarchy... Expanded...H04R 25/00)

|  | H04R 1/06 |
· | Arranging circuit leads; Relieving strain on circuit leads

|  | H04R 1/08 |
· | Mouthpieces; Attachments therefor

|  | H04R 1/10 |
· | Earpieces; Attachments therefor

|  | H04R 1/12 |
· | Sanitary or hygienic devices for mouthpieces or earpieces, e.g. for protecting against infection

|  | H04R 1/14 |
· | Throat mountings for microphones

|  | H04R 1/16 |
· | Mounting or connecting stylus to transducer with or without damping means

|  | H04R 1/18 |
· · | Holders for styli; Mounting holders on transducers

|  | H04R 1/20 |
· | Arrangements for obtaining desired frequency or directional characteristics (for stereophonic purposes Fulltext... Hierarchy... Expanded...H04R 5/00)

|  | H04R 1/22 |
· · | for obtaining desired frequency characteristic only (circuits for combining transducers having different responses Fulltext... Hierarchy... Expanded...H04R 3/00)

|  | H04R 1/24 |
· · · | Structural combinations of separate transducers or of parts of the same transducer and responsive respectively to two or more frequency ranges

|  | H04R 1/26 |
· · · | Spatial arrangement of separate transducers responsive to two or more frequency ranges

|  | H04R 1/28 |
· · · | Transducer mountings or enclosures designed for specific frequency response; Transducer enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means

|  | H04R 1/30 |
· · · | Combinations of transducers with horns, e.g. with mechanical matching means (horns in general Fulltext... Hierarchy... Expanded...G10K)

|  | H04R 1/32 |
· · | for obtaining desired directional characteristic only

|  | H04R 1/34 |
· · · | by using a single transducer with sound reflecting, diffracting, directing or guiding means

|  | H04R 1/36 |
· · · · | by using a single aperture of dimensions not greater than the shortest operating wavelength

|  | H04R 1/38 |
· · · · | in which sound waves act upon both sides of a diaphragm and incorporating acoustic phase-shifting means, e.g. pressure-gradient microphone

|  | H04R 1/40 |
· · · | by combining a number of identical transducers

|  | H04R 1/42 |
· | Combinations of transducers with fluid-pressure or other non-electrical amplifying means

|  | H04R 1/44 |
· | Special adaptations for subaqueous use, e.g. for hydrophone

|  | H04R 1/46 |
· | Special adaptations for use as contact microphones, e.g. on musical instrument, on stethoscope (throat mountings Fulltext... Hierarchy... Expanded...H04R 1/14)

|  | H04R 3/00 |
Circuits for transducers (for stereophonic arrangements Fulltext... Hierarchy... Expanded...H04R 5/04; amplifiers Fulltext... Hierarchy... Expanded...H03F)

|  | H04R 3/02 |
· | for preventing acoustic reaction

|  | H04R 3/04 |
· | for correcting frequency response

|  | H04R 3/06 |
· · | of electrostatic transducers

|  | H04R 3/08 |
· · | of electromagnetic transducers

|  | H04R 3/10 |
· · | of variable-resistance microphones

|  | H04R 3/12 |
· | for distributing signals to two or more loud-speakers

|  | H04R 3/14 |
· · | Cross-over networks

|  | H04R 5/00 |
Stereophonic arrangements (stereophonic pick-ups Fulltext... Hierarchy... Expanded...H04R 9/16, Fulltext... Hierarchy... Expanded...H04R 11/12, Fulltext... Hierarchy... Expanded...H04R 17/08, Fulltext... Hierarchy... Expanded...H04R 19/10)

|  | H04R 5/02 |
· | Spatial or constructional arrangements of loud-speakers

|  | H04R 5/04 |
· | Circuit arrangements (combinations of amplifiers Fulltext... Hierarchy... Expanded...H03F 3/68)

|  | H04R 7/00 |
Diaphragms for electromechanical transducers (in general Fulltext... Hierarchy... Expanded...F16J 3/00); Cones (for musical instruments Fulltext... Hierarchy... Expanded...G10)

|  | H04R 7/02 |
· | characterised by the construction

|  | H04R 7/04 |
· · | Plane diaphragms

|  | H04R 7/06 |
· · · | comprising a plurality of sections or layers

|  | H04R 7/08 |
· · · · | comprising superposed layers separated by air or other fluid

|  | H04R 7/10 |
· · · · | comprising superposed layers in contact

|  | H04R 7/12 |
· · | Non-planar diaphragms or cones

|  | H04R 7/14 |
· · · | corrugated, pleated, or ribbed

|  | H04R 7/16 |
· | Mounting or tensioning of diaphragms or cones

|  | H04R 7/18 |
· · | at the periphery

|  | H04R 7/20 |
· · · | Securing diaphragm or cone resiliently to support by flexible material, springs, cords, or strands

|  | H04R 7/22 |
· · · | Clamping rim of diaphragm or cone against seating

|  | H04R 7/24 |
· · | Tensioning by means acting directly on free portion of diaphragm or cone

|  | H04R 7/26 |
· | Damping by means acting directly on free portion of diaphragm or cone (air damping Fulltext... Hierarchy... Expanded...H04R 1/28)

|  | H04R 9/00 |
Transducers of moving-coil, moving-strip, or moving-wire type

|  | H04R 9/02 |
· | Details

|  | H04R 9/04 |
· · | Construction, mounting, or centring of coil

|  | H04R 9/06 |
· | Loud-speakers

|  | H04R 9/08 |
· | Microphones

|  | H04R 9/10 |
· | Telephone receivers

|  | H04R 9/12 |
· | Gramophone pick-ups using a stylus; Recorders using a stylus

|  | H04R 9/14 |
· · | comprising two or more styli or transducers (Fulltext... Hierarchy... Expanded...H04R 9/16 takes precedence)

|  | H04R 9/16 |
· · | signals being recorded or played-back by vibration of a stylus in two orthogonal directions simultaneously

|  | H04R 9/18 |
· | Resonant transducers, i.e. adapted to produce maximum output at a predetermined frequency

|  | H04R 11/00 |
Transducers of moving-armature or moving-core type (acoustic diaphragm of magnetisable material directly co-acting with electromagnet Fulltext... Hierarchy... Expanded...H04R 13/00)

|  | H04R 11/02 |
· | Loud-speakers

|  | H04R 11/04 |
· | Microphones

|  | H04R 11/06 |
· | Telephone receivers

|  | H04R 11/08 |
· | Gramophone pick-ups using a stylus; Recorders using a stylus

|  | H04R 11/10 |
· · | comprising two or more styli or transducers (Fulltext... Hierarchy... Expanded...H04R 11/12 takes precedence)

|  | H04R 11/12 |
· · | signals being recorded or played-back by vibration of a stylus in two orthogonal directions simultaneously

|  | H04R 11/14 |
· | Resonant transducers, i.e. adapted to produce maximum output at a predetermined frequency

|  | H04R 13/00 |
Transducers having an acoustic diaphragm of magnetisable material directly co-acting with electromagnet

|  | H04R 13/02 |
· | Telephone receivers

|  | H04R 15/00 |
Magnetostrictive transducers (selection of magnetostrictive materials Fulltext... Hierarchy... Expanded...H01L 41/00)

|  | H04R 15/02 |
· | Resonant transducers, i.e. adapted to produce maximum output at a predetermined frequency

|  | H04R 17/00 |
Piezo-electric transducers; Electrostrictive transducers (selection of piezo-electric or electrostrictive materials Fulltext... Hierarchy... Expanded...H01L 41/00)

|  | H04R 17/02 |
· | Microphones

|  | H04R 17/04 |
· | Gramophone pick-ups using a stylus; Recorders using a stylus

|  | H04R 17/06 |
· · | comprising two or more styli or transducers (Fulltext... Hierarchy... Expanded...H04R 17/08 takes precedence)

|  | H04R 17/08 |
· · | signals being recorded or played-back by vibration of a stylus in two orthogonal directions simultaneously

|  | H04R 17/10 |
· | Resonant transducers, i.e. adapted to produce maximum output at a predetermined frequency

|  | H04R 19/00 |
Electrostatic transducers

|  | H04R 19/02 |
· | Loud-speakers

|  | H04R 19/04 |
· | Microphones

|  | H04R 19/06 |
· | Gramophone pick-ups using a stylus; Recorders using a stylus

|  | H04R 19/08 |
· · | comprising two or more styli or transducers (Fulltext... Hierarchy... Expanded...H04R 19/10 takes precedence)

|  | H04R 19/10 |
· · | signals being recorded or played-back by vibration of a stylus in two orthogonal directions simultaneously

|  | H04R 21/00 |
Variable-resistance transducers (gaseous-resistance transducers Fulltext... Hierarchy... Expanded...H04R 23/00; magneto-resistive transducers Fulltext... Hierarchy... Expanded...H04R 23/00)

|  | H04R 21/02 |
· | Microphones

|  | H04R 21/04 |
· | Gramophone pick-ups using a stylus; Recorders using a stylus

|  | H04R 23/00 |
Transducers other than those covered by groups Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...H04R 9/00-H04R 21/00

|  | H04R 23/02 |
· | Transducers using more than one principle simultaneously

|  | H04R 25/00 |
Deaf-aid sets (constructions of transducers per se Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...H04R 9/00-H04R 23/00; structural combination with spectacle frames Fulltext... Hierarchy... Expanded...G02C 11/06)

|  | H04R 25/02 |
· | adapted to be supported entirely by ear

|  | H04R 25/04 |
· | comprising pocket amplifiers

|  | H04R 27/00 |
Public address systems (circuits for preventing acoustic reaction Fulltext... Hierarchy... Expanded...H04R 3/02; circuits for distributing signals to loud-speakers Fulltext... Hierarchy... Expanded...H04R 3/12; amplifiers Fulltext... Hierarchy... Expanded...H03F)

|  | H04R 27/02 |
· | Amplifying systems for the deaf

|  | H04R 27/04 |
· | Electric megaphones

|  | H04R 29/00 |
Monitoring arrangements; Testing arrangements

|  | H04R 31/00 |
Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor