Title:
TELEPHONE SYSTEM
Document Type and Number:
Japanese Patent JP3473270
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To detect incoming caller information at call waiting without being destroyed by voice signal or the like by muting a transmission circuit in the case of receiving caller information sent from a station exchange after an alert signal.
SOLUTION: A mute control means 5 mutes a transmission circuit 10 after lapse of a prescribed time from the transmission of an ACK signal to a telephone line 1 by an instruction of a control means 8. The mute circuit 10a in the transmission circuit 10 is operated by a signal from the mute control means 5 to decrease a gain of a transmission amplifier. The timing when the mute control means 5 conducts muting is in matching with a timing when an exchange of a telephone station (station exchange) transmits caller information in response to the ACK signal. Since the voice signal or the like from the telephone set is stopped when the station exchange sends the caller information, when the caller information is received, the caller information is not destroyed by the voice signal or the like.
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Inventors:
Koji Yamanishi
Takako Ito
Koichi Kamimoto
Takako Ito
Koichi Kamimoto
Application Number:
JP11986096A
Publication Date:
December 02, 2003
Filing Date:
May 15, 1996
Export Citation:
Assignee:
Matsushita Electric Industrial Co., Ltd
International Classes:
H04M3/42; H04M1/00; H04M1/57; H04M1/72; H04M1/725; (IPC1-7): H04M1/725; H04M1/00; H04M1/57
Domestic Patent References:
| JP5199304A | ||||
| JP685890A | ||||
| JP383436A |
Attorney, Agent or Firm:
Fumio Iwahashi (2 others)