DIFF Main Group
H04K 1/00 Secret communication
Introduced: September 1968
Of 7 combined children, 5 exist in both systems.
2 codes are CPC-only extensions.
Child Classifications
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- H04K 1/02 by adding a second signal to make the desired signal unintelligible +1 CPC IPC+CPC Available in IPC and CPC
- H04K 1/04 by frequency scrambling, i.e. by transposing or inverting parts of the frequency band or by inverting the whole band IPC+CPC Available in IPC and CPC
- H04K 1/06 by transmitting the information or elements thereof at unnatural speeds or in jumbled order or backwards IPC+CPC Available in IPC and CPC
- H04K 1/10 by using two signals transmitted simultaneously or successively 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