The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 06, 2002
Filed:
Feb. 09, 1999
Katsuya Suzuki, Tokyo, JP;
Hiroshi Nakagiri, Tokyo, JP;
Oki Electric Industry Co, Ltd., Tokyo, JP;
Abstract
A speech voice input to the microphone is converted into a digital signal by an A/D converter . An encoder in turn spreads the digital signal using a spread spectrum scheme and the spread signal is supplied to the modulator . A modulator modulates a carrier wave (e.g., a frequency of 800 MHz) with the spread signal and the modulated wave is transmitted from an antenna . A high-frequency signal is induced in a paired cable of a headset by the transmitted wave. The high-frequency signal transferred in the direction to the telephone unit through the cable is eliminated by an LPF . On the other hand, the high-frequency signal transferred to a headphone passes through a capacitor to a ground level. Thus, the entry of the transmitted signal into the amplifier and the headphone can be avoided, and an occurrence of noise in the headphone can be prevented.