IPC Main Group
H04S 1/00 Two-channel systems
Introduced: January 1980
Last revised: January 2006
Classification Context
- Section:
- ELECTRICITY
- Class:
- ELECTRIC COMMUNICATION TECHNIQUE
- Subclass:
- STEREOPHONIC SYSTEMS
Additional Content
Pseudo-stereophonic systems Indicating arrangements of stereophonic systems; Control arrangements, e.g. balance control of stereophonic systems
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