DIFF Main Group
H04R 21/00 Variable-resistance transducers (gaseous resistance transducers H04R23/00; magneto-resistive transducers H04R23/00)
Introduced: September 1968
Title
Titles differ between systems:
IPC: Variable-resistance transducers
CPC: Variable-resistance transducers (gaseous resistance transducers H04R23/00; magneto-resistive transducers H04R23/00)
Full Title
Full titles differ between systems:
IPC:
Variable-resistance transducers
CPC:
Variable-resistance transducers (gaseous resistance transducers H04R23/00; magneto-resistive transducers H04R23/00)
Additional Content IPC
Gaseous resistance transducers Magneto resistive transducers
IPC and CPC are identically structured here. All 2 subcodes exist in both systems.
Child Classifications
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- H04R 21/04 Gramophone pick-ups using a stylus; Recorders using a stylus IPC+CPC Available in IPC and CPC
Top Applicants
Top Applicants (IPC)
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
Top Applicants (CPC)
Class H04,2013–2023, worldwide · Source: EPO PATSTAT
- HUAWEI TECHNOLOGIES COMPANY CN 101,476
- QUALCOMM US 101,139
- SAMSUNG ELECTRONICS COMPANY KR 96,655
- TELEFONAKTIEBOLAGET LM ERICSSON (PUBL) SE 57,744
- LG ELECTRONICS KR 55,253
- HUAWEI TECHNOLOGIES COMPANY 54,181
- SONY CORPORATION JP 35,309
- ZTE CORPORATION CN 32,950
- INTEL CORPORATION US 27,533
- GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORPORATION CN 27,498