U.S. patents available from 1976 to present.
U.S. patent applications available from 2005 to present.

Low-feedback compact wireless telephone

Patent 5819183 Issued on October 6, 1998. Estimated Expiration Date: Icon_subject October 6, 2015. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Patent References

D210462

D249508

D273307

D293097

D293671

D297946

D309306

D313243

D318865

D326450

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Inventors

Assignee

Application

No. 262735 filed on 06/20/1994

US Classes:

455/570, Noise suppression or echo cancellation368/13Telephone

Examiners

Primary: Cumming, William
Assistant: Trost, William

Attorney, Agent or Firm

Foreign Patent References

  • 1 132 201 DE. 06/13/1962

International Class

H04Q 007/32

Abstract

The present invention is directed to apparatus and methods for reducing sidetone feedback in a portable wireless telephone system by positioning the speaker and the microphone to reduce acoustic feedback and by controlling the amplifier gain in the transmitter section of the wireless telephone to reduce amplification of sidetone which has been acoustically coupled from the speaker to the microphone. The wireless telephone may be configured as a watch with a wrist strap for retaining it to the user, as a piece of jewelry such as a brooch or pendant, as a voice capable pager/intercom, or as an identification badge for an employee. In one embodiment, the base station includes circuitry for further reducing sidetone feedback. In additional embodiments, the wireless telephone may include a quick-release outboard battery, a retractable earpiece, and an ergonomic keypad.

Other References

  • Battery pack for Sonab hand transceivers Pu 38 and Pu 45 (Jun. 1975
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