Patent Leaderboard

USPTO Patent Rankings Data through Dec 31, 2025

Search Companies Inventors Cities States

Home › Telephone

Telephone

US Patent D278904 · Granted May 21, 1985

Assignee

No assignee recorded.

Inventors

Donald R. White (8 patents)

View full patent text on Google Patents →

More Patents by These Inventors

Audio headset2006

Full duplex communication circuits with bilateral T hybrid and balanced impedanc2002

Full duplex communication circuit with a transducer for simultaneously generatin1999

Duplex transducer for simultaneous voice broadcast and reception1993

Electrical connector1989

Method and apparatus for duplex communications1987

Operation of microbial fuel cells1987

Data from USPTO via PatentsView — © 2026 Patent Leaderboard

Last updated: Dec 31, 2025 · Updated quarterly