Acoustic signal transmitting system

• US 5,423,073 A
• Filed: 09/22/1992
• Issued: 06/06/1995
• Est. Priority Date: 09/30/1991
• Status: Expired due to Fees

• Current Assignee: Fuji Xerox Company Limited (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Xerox Company Limited (Fujifilm Holdings Corporation)
• Inventors: Ogawa, Yutaka
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): LIN, MARY
• Application Number:
  US07/948,435
• Time in Patent Office: 987 Days
• Field of Search: 455/70, 455/226, 381/77, 381/92, 381/94, 179/18 BC, 379/202, 379/62, 379/53, 379/54, 178/5.1
• US Class Current: 455/70
• CPC Class Codes: H04H 20/31 using in-band signals, e.g. subsonic or cue signal

Abstract

An acoustic signal transmitting system comprises, at a transmission side, a plurality of acoustic input means each for producing an individual acoustic signal; a discriminating signal memory for storing a discriminating signal corresponding to each of the acoustic input means; a modulator for modulating the discriminating signal into a signal with a predetermined acoustic frequency; and a transmission controller for transmitting the acoustic signal when the acoustic input means output the acoustic signal and for transmitting the discriminating signal modulated by the modulator when the acoustic input means do not output the acoustic signal. The system also comprises, at a reception side, a filter for separating the discriminating signal and the acoustic signal from a transmission signal transmitted from the signal transmitting unit through the single channel; a management memory means for storing a table for managing a unique discriminating signal corresponding to each of the acoustic input means and data related to the unique discriminating signal; a reception controller for comparing the discriminating signal separated by the filter with the discriminating signal stored in the management memory to determined whether or not a corresponding acoustic signal exists in the management memory, and for processing the acoustic signal; and means for utilizing the discriminating signal and the corresponding acoustic signal.

Claims

1. An acoustic signal transmitting system capable of performing signal transmission through a single channel, comprising:

a signal transmitting unit which comprises;

a plurality of acoustic input means each for producing an individual acoustic signal;

a discriminating signal memory for storing a plurality of discriminating signals each corresponding to each of said acoustic input means;

first modulation means for modulating said plurality of discriminating signals into a plurality of signals each with a predetermined acoustic frequency; and

transmission control means which transmits at least one of the plurality of acoustic signals when at least one of the plurality of acoustic input means outputs said at least one of the plurality of said acoustic signals and transmits a corresponding one of the plurality of discriminating signals modulated by said first modulating means when said acoustic input means does not output said at least one of the plurality of acoustic signals; and

a signal receiving unit which comprises;

filter means for separating said corresponding one of the plurality of discriminating signals and at least one of the plurality of acoustic signals from a transmission signal transmitted from said signal transmitting unit through said single channel;

a management memory means for storing a table for managing the plurality of discriminating signals corresponding to each of the plurality of acoustic input means and data related to the plurality of discriminating signals;

reception control means for comparing said corresponding one of the plurality of discriminating signals separated by said filter with said plurality of discriminating signals stored in said management memory means to determine whether or not a corresponding acoustic signal exists in said management memory means, and for processing said at least one of the plurality of acoustic signals; and

means for utilizing said corresponding one of the plurality of discriminating signals and said at least one of the plurality of acoustic signals corresponding to said corresponding one of the plurality of discriminating signals so as to discriminate each of said acoustic input signals.

2. A system as claimed in claim 1, wherein said transmission control means periodically transmits said corresponding one of the plurality of discriminating signals.

3. A system as claimed in claim 1, wherein said management memory means has a table for determining the status of each said plurality of acoustic input means according to said corresponding one of the plurality of discriminating signals transmitted at a previous time and said corresponding one of the plurality of discriminating signals transmitted at a current time.

4. A system as claimed in claim 1, wherein said signal transmission unit further comprises second modulation means for modulating a signal output from said transmission control means into a signal with a transmission frequency.

5. A system as claimed in claim 4, wherein said second modulation means receives said corresponding one of the plurality of discriminating signals modulated by said first modulation means when a signal level of said at least one of the plurality of acoustic signals from said plurality of acoustic input means is lower than a predetermined value, and receives said at least one of the plurality of acoustic signals from said plurality of acoustic input means when the signal level of said at least one of the plurality of acoustic signals from said plurality of acoustic input means is at least equal to said predetermined value.