Title:
SPEECH COMMUNICATION EQUIPMENT PROVIDED WITH ECHO CANCELLER
Document Type and Number:
Japanese Patent JP3310070
Kind Code:
B2
Abstract:
PURPOSE: To set the reception sound volume as desired by a user without degrading the performance of an echo canceller at the time of the fluctuation of the reception signal level.
CONSTITUTION: Variable resistors 55 and 16 are inserted to the input side in an echo canceller 50 in a reception signal line and the output side of a mixer 14 for tone signal input. The gain of the variable resistor 16 is variably controlled during handset speaking or in the period of tone signal output in accordance with the manipulated variable of a sound volume control key 43c by a reception sound volume control means 40a of a control circuit 40, and the gain of the variable resistor 55 on the input side of the echo canceller 50 is variably controlled during hand-free speaking in accordance with the manipulated variable of a sound volume control key 43c.
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Inventors:
Yuji Umemoto
Application Number:
JP26730493A
Publication Date:
July 29, 2002
Filing Date:
October 26, 1993
Export Citation:
Assignee:
Toshiba Corporation
International Classes:
H04M1/60; (IPC1-7): H04M1/60; H04Q7/38
Domestic Patent References:
| JP332142A | ||||
| JP316438A | ||||
| JP3114344A |
Attorney, Agent or Firm:
Takehiko Suzue