US Patent No: 4,956,876

Number of patents in Portfolio can not be more than 2000

DC decoupled radio communication system

Stats

ATTORNEY / AGENT: (SPONSORED)
 

Importance

Loading Importance Indicators... loading....

Abstract

A radio communication system includes a radio unit, an interface circuit, a microphone and a fascimile unit. The interface unit includes a transformer through which signals are transferred between the radio unit and a seelcted one of the microphone and the facsimile unit so that d.c. components of the signals cannot be transferred. The interface circuit also includes a first relay connected between one winding of the transformer and the microphone and the facsimile unit and a second relay connected between the other winding of the transformer and the radio unit. The system also includes a mode select switch which is operatively coupled to the first and second relays. Thus, mode select signals are also d.c. decoupled signals.

Loading the Abstract Image... loading....

First Claim

Related Publications

Loading Related Publications... loading....

Patent Owner(s)

Patent OwnerAddressTotal Patents
RICOH COMPANY, LTD.TOKYO15816

International Classification(s)

  • [Classification Symbol]
  • [Patents Count]

Inventor(s)

Inventor Name Address # of filed Patents Total Citations
Koshiishi, Takaho Tokyo, JP 17 291

Cited Art

Patent Info (Count) # Cites Year
 
AISIN SEIKI KABUSHIKI KAISHA (1)
4,796,091 Facsimile apparatus 20 1987
 
CANON KABUSHIKI KAISHA (1)
4,773,080 Data communication equipment 39 1985
 
WILLIAMS ELECTRONICS LTD. (1)
4,809,297 Interface device 16 1984

Patent Citation Ranking

Forward Cites

Patent Info (Count) # Cites Year
 
FUJITSU MOBILE COMMUNICATIONS LIMITED (2)
5,590,414 Adapter unit for a portable radio telephone enabling either one of data transmission and hand-free operation 19 1992
5,584,055 Adapter unit for adaptively supplying a portable radio telephone with power 18 1994
 
FUJITSU TOSHIBA MOBILE COMMUNICATIONS LIMITED (2)
5,444,867 Adapter unit for adaptively supplying a portable radio telephone with power 14 1992
5,367,556 Portable radio telephone used with an adaptor unit having a hand-free circuit 33 1992
 
MOTOROLA, INC. (2)
5,237,429 Facsimile interface device for radios 31 1992
5,321,737 Cordless telephone communication system having base stations with memory for quick access to information 42 1993
 
RICOH COMPANY, LTD. (2)
5,452,474 Externally attached handset of an end terminal used for mobile communication systems 13 1994
7,154,534 Image input apparatus, program executed by computer, and method for preparing document with image 14 2001
 
HITACHI, LTD. (1)
5,805,678 Cordless subunit facsimile system 7 1993
 
KABUSHIKI KAISHA TOSHIBA (1)
5,200,991 Image communication system including a mobile telephone set and a facsimile device 49 1991
 
LEXMARK INTERNATIONAL, INC. (1)
7,151,949 Wireless facsimile adapter and system for printer and all-in-one devices and methods using the same 6 2003
 
PETERSON, FRED (1)
5,937,334 Radio communications and telephone network interface system 12 1996
 
SIERRA WIRELESS, INC. (1)
5,629,960 Method for reducing distortion effects on DC off-set voltage and symbol clock tracking in a demodulator 12 1995
 
SONY CORPORATION (1)
5,175,875 Radio communication apparatus with programmable signal modulation 30 1990