Skip to content
Search Classifications
Search for IPC and CPC classification codes or keywords
IPC Subgroup
H04S 3/02

of the matrix type, i.e. in which input signals are combined algebraically, e.g. after having been phase shifted with respect to each other

Introduced: January 1980

Last revised: January 2006

Full Title

Systems employing more than two channels, e.g. quadraphonic > of the matrix type, i.e. in which input signals are combined algebraically, e.g. after having been phase shifted with respect to each other

Classification Context

Section:
ELECTRICITY
Class:
ELECTRIC COMMUNICATION TECHNIQUE
Subclass:
STEREOPHONIC SYSTEMS

Top Applicants

Top 10 applicants by patent filingsfor 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