Conference system

• US 4,730,306 A
• Filed: 10/03/1985
• Issued: 03/08/1988
• Est. Priority Date: 10/11/1984
• Status: Expired due to Fees

• Current Assignee: Iwatsu Electric Company Limited
• Original Assignee: Iwatsu Electric Company Limited
• Inventors: Uchida, Seiya
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): Chin, Wellington
• Application Number:
  US06/783,777
• Time in Patent Office: 887 Days
• Field of Search: 370/62, 379/202, 375/30, 375/98
• US Class Current: 370/263
• CPC Class Codes: H04M 3/561 by multiplexing
• CPC Class Codes: H04M 3/568 audio processing specific to telephonic conferencing, e.g. spatial distribution, mixing of participants echo suppression in two-way loud-speaking telephone systems H04M9/02; sound field processing per se H04S7/30

Abstract

A conference system is disclosed which is capable of freely setting the sound volume level by making the sound volume levels of the input and output of the conference circuit variable for each participant, by pluralities of input and output ROM converters so that the levels of voices of participants of large and small line losses are made as close to each other as possible and that the participant of a large line loss is supplied with a voice of low attenuation.

Claims

1. A conference system in which PCM codes input from a plurality of communication lines on a time-division basis are converted to linear codes, conference-operated, reconverted to PCM codes and then output to the communication lines on the time-division basis, comprising:

a plurality of first ROM converters, each provided for a predetermined amplification or attenuation degree, for amplifying or attenuating the sound volumes of the input PCM codes in connection with their voice signal levels and for converting them to linear codes;

a plurality of second ROM converters, each provided for a predetermined amplification or attenuation degree, for amplifying or attenuating the sound volumes of the linear codes in connection with their voice signal levels and converting them to PCM codes; and

storage means for storing the kind of one of the first ROM converters and the kind of one of the second ROM converters specified each conference-operated communication line;

wherein the PCM codes input from the plurality of communication lines are each applied to one of the first ROM converters determined by the storage means for each communication line and subjected to a conference operation and the operation results are provided on the plurality of communication lines via the second ROM converters, each determined by the storage means for each communication line, thereby correcting the attenuation of the sound volume for each communication line to obtain an appropriate sound volume for conference.