发明名称 DTMF Generating assistant
摘要 A DTMF generating device for automatically generating DTMF tones corresponding to a predefined phone number comprises a processor, a memory, and a speaker enveloped in a credit card sized casing. The memory has stored therein DTMF tone samples corresponding to the predefined phone number. When a user presses on a portion of the casing, the DTMF tone samples are played by the speaker.
申请公布号 US7409055(B2) 申请公布日期 2008.08.05
申请号 US20070691881 申请日期 2007.03.27
申请人 AT&T DELAWARE INTELLECTUAL PROPERTY, INC. 发明人 RUCKART JOHN P.
分类号 H04M3/00 主分类号 H04M3/00
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