Audio current pick-up device

• US 5,010,575 A
• Filed: 05/17/1989
• Issued: 04/23/1991
• Est. Priority Date: 05/30/1988
• Status: Expired due to Fees

• Current Assignee: Rion Kabushiki Kaisha
• Original Assignee: Rion Kabushiki Kaisha
• Inventors: Fukutome, Tatsuro, Marutake, Yozo, Asami, Motomu
• Primary Examiner(s): Ng, Jin F.
• Assistant Examiner(s): Chan, Jason
• Application Number:
  US07/353,839
• Time in Patent Office: 706 Days
• Field of Search: 381/68, 379/443, 84/725, 84/726, 84/727, 84/728, 324/117 R, 324/127
• US Class Current: 381/331
• CPC Class Codes: H04B 5/24 Inductive coupling
• CPC Class Codes: H04M 1/215 by non-intrusive coupling means, e.g. acoustic couplers
• CPC Class Codes: H04R 2225/51 Aspects of antennas or their circuitry in or for hearing aids
• CPC Class Codes: H04R 25/502 using analog signal processing
• CPC Class Codes: H04R 25/554 using a wireless connection, e.g. between microphone and amplifier or using Tcoils

Abstract

An audio current pick-up device for use with an electric wire 6 carrying an electric current containing audio information comprises a pair of substantially identical magnetic induction coil assemblies 26, 27 disposed in parallel to each other with an axial deviation and orthogonally to the wire, each coil means including a magnetic core in the form of rod 30, 38 and a pair of induction coils 32A, 32B, 39A, 39B wound in opposite directions on respective halves of its core rod. An output of either of the induction coils is phase-shifted by a preset amount and composited with an output of the other magnetic induction coil to form a sound pick-up signal from which a sound output signal is derived.

Claims

1. An audio current pick-up device comprising a first magnetic induction coil means including at least one induction coil, a second magnetic induction coil means including at least one induction coil, said first and said second magnetic induction coil means being arranged in parallel to each other with an axial positional deviation of said induction coil of said first magnetic induction coil means with respect to that of said second magnetic induction coil means by a predetermined amount, and circuit means for combining output signals of said first and said second magnetic induction coil means to form a sound output signal, wherein said first and said second magnetic induction coil means include magnetic rod cores, respectively, and wherein a pair of coils are wound in opposite directions on respective halves of each of said magnetic rod cores, said pair of coils being connected in parallel to each other, and said output signals being derived from said coil pairs.

2. An audio current pick-up device according to claim 1, further comprising means for phase-shifting one of said output signals by a predetermined amount, and means for combining said phase-shifted output signal with the other output signal to form a sound pick-up signal, and wherein said sound output signal is produced on the basis of said sound pick-up signal.

3. The device as claimed in claims 1 or 2, further comprising an earphone having an input connected to an output of said circuit means.