H04R LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
Introduced: September 1968
Last revised: January 1995
Classification Context
- Section:
- ELECTRICITY
- Class:
- ELECTRIC COMMUNICATION TECHNIQUE
- Subclass:
- LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
Description
H04R encompasses devices that convert between acoustic signals and electrical signals for sound reception, reproduction, or amplification. This subclass covers loudspeakers and related output transducers, microphones and input transducers, gramophone pick-ups, and acoustic-electromechanical transducers of similar type. It also includes electric hearing aids designed to amplify sound for hearing-impaired individuals and public address systems that project audio to large audiences. Excluded are purely mechanical sound reproduction devices and non-acoustic applications of electromagnetic transducers.
Additional Content
Acoustic Sound sounds cover the technical field dealing with ultrasonic, sonic or infrasonic waves Deaf aid hearing aid Loudspeaker Loudspeakers transducer generally mounted in a casing for producing sound Microphone microphones transducer generally mounted in a casing for collecting sound Stereophonic system stereophonic systems two- or more channel system, e.g. quadraphonic, ambisonic or similar system Transducer Transducers a device that converts an electrical signal to an acoustic signal with a frequency which is determined by the frequency of the electrical signal applied to the transducer, or vice versa
Related Keywords
16 direct subcodes
Child Classifications
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- H04R 1/00 Details of transducers
- H04R 11/00 Transducers of moving-armature or moving-core type
- H04R 13/00 Transducers having an acoustic diaphragm of magnetisable material directly co-acting with electromagnet
- H04R 15/00 Magnetostrictive transducers
- H04R 17/00 Piezoelectric transducers; Electrostrictive transducers
- H04R 19/00 Electrostatic transducers
- H04R 21/00 Variable-resistance transducers
- H04R 23/00 Transducers other than those covered by groups
- H04R 25/00 Electric hearing aids
- H04R 27/00 Public address systems
- H04R 29/00 Monitoring arrangements; Testing arrangements
- H04R 3/00 Circuits for transducers
- H04R 31/00 Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor
- H04R 5/00 Stereophonic arrangements
- H04R 7/00 Diaphragms for electromechanical transducers; Cones
- H04R 9/00 Transducers of moving-coil, moving-strip, or moving-wire type
Top Applicants
Top 10 applicants by patent filingsfor class H04, 2013–2023, worldwide · Source: EPO PATSTAT
- QUALCOMM US 97,396
- HUAWEI TECHNOLOGIES COMPANY CN 96,502
- SAMSUNG ELECTRONICS COMPANY KR 86,981
- TELEFONAKTIEBOLAGET LM ERICSSON (PUBL) SE 55,869
- HUAWEI TECHNOLOGIES COMPANY 55,349
- LG ELECTRONICS KR 53,649
- CANON 33,341
- SONY CORPORATION JP 32,761
- ZTE CORPORATION CN 32,274
- GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORPORATION 28,327