Inventor
OOHASHI MAKOTO
JP4 patents
Patents
4 patentsUS7532606B2May 12, 2009
DTMF signal transmission method and communication apparatus
HITACHI TELECOMM TECH4 citations72
US7062033B2Jun 13, 2006
DTMF signal transmission method and communication apparatus
HITACHI TELECOMM TECH5 citations72
US6700973B1Mar 2, 2004
System for transmitting DTMF signal and communication equipment thereof
HITACHI TELECOMM TECH4 citations72
US7050570B2May 23, 2006
DTMF signal transmission method and communication apparatus
HITACHI TELECOMM TECH1 citations61