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DIFF Subgroup
H04R 1/28

Transducer mountings or enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means

Introduced: September 1968

Title

Titles differ between systems:

IPC: Transducer mountings or enclosures designed for specific frequency response; Transducer enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means

CPC: Transducer mountings or enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means

Full Title

Full titles differ between systems:

IPC:

Details of transducers > Arrangements for obtaining desired frequency or directional characteristics > for obtaining desired frequency characteristic only > Transducer mountings or enclosures designed for specific frequency response; Transducer enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means

CPC:

Details of transducers, > Arrangements for obtaining desired frequency or directional characteristics (for stereophonic purpose H04R5/00) > for obtaining desired frequency characteristic only > Transducer mountings or enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means

Additional Content IPC

Limiting references

Constructional features of telephone transmitters or receivers, e.g. telephone hand-sets

Application references

Adaptations to the transducers itself (e.g. a Helmholtz resonator attached to a through-hole in the magnetic circuit of an electrodynamic loudspeakertransducers) in order to modify the frequency response is classified at the transducer place - , e.g.

Of 3 combined children, 0 exist in both systems.

3 codes are CPC-only extensions.

Child Classifications

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Top Applicants

Top Applicants (IPC)

Class H04,2013–2023, worldwide · Source: EPO PATSTAT

  1. QUALCOMM US 97,396
  2. HUAWEI TECHNOLOGIES COMPANY CN 96,502
  3. SAMSUNG ELECTRONICS COMPANY KR 86,981
  4. TELEFONAKTIEBOLAGET LM ERICSSON (PUBL) SE 55,869
  5. HUAWEI TECHNOLOGIES COMPANY 55,349
  6. LG ELECTRONICS KR 53,649
  7. CANON 33,341
  8. SONY CORPORATION JP 32,761
  9. ZTE CORPORATION CN 32,274
  10. GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORPORATION 28,327

Top Applicants (CPC)

Class H04,2013–2023, worldwide · Source: EPO PATSTAT

  1. HUAWEI TECHNOLOGIES COMPANY CN 101,476
  2. QUALCOMM US 101,139
  3. SAMSUNG ELECTRONICS COMPANY KR 96,655
  4. TELEFONAKTIEBOLAGET LM ERICSSON (PUBL) SE 57,744
  5. LG ELECTRONICS KR 55,253
  6. HUAWEI TECHNOLOGIES COMPANY 54,181
  7. SONY CORPORATION JP 35,309
  8. ZTE CORPORATION CN 32,950
  9. INTEL CORPORATION US 27,533
  10. GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORPORATION CN 27,498