US 4,230,013 A · Electro-acoustic transducer

Abstract

An electro-acoustic transducer for a musical instrument, for producing electrical signals indicative of sound produced by playing of the instrument. The transducer comprises a housing of plastic material containing a capacitor microphone arrangement which comprises a first metal foil electrode within a sheath of metal foil which defines a second electrode. A dielectric separates the two electrodes. The capacitor microphone arrangement is sandwiched between a relatively rigid wall of the housing and a relatively flexible body of plastic material within the housing. The housing is adapted to be mounted in intimate contact with a surface of the instrument which vibrates in accordance with sound produced by playing of the instrument, so that the vibrations are transmitted to the electrodes. A constant electrical potential difference is applied to the electrodes and oscillatory voltages produced by the vibration of the electrodes are amplified by an amplifier to produce an electrical signal indicative of the music produced by the instrument.

Claims20

Dependent claims

An electro-acoustic transducer for providing electrical signals corresponding to sounds in a vibratory surface of a musical instrument, comprising

(a) a relatively flexible body of plastic material;
(b) a relatively rigid support member of plastic material for attachment to a musical instrument on a surface thereof which vibrates in accordance with sound produced by playing of the instrument;
and
(c) a capacitor microphone arrangement sandwiched between said support member and said body, said capacitor microphone arrangement comprising
(i) a first electrode comprising an elongate foil of electrically conductive material;
(ii) a second electrode comprising an elongate flat sheath of electrically conductive foil within which said first electrode is received;
and
(iii) a dielectric between said electrodes and electrically insulating said electrodes from one another.

5 more elements

The combination of a musical instrument, an electro-acoustic transducer for providing electrical signals corresponding to sounds in a vibratory surface of said instrument, said transducer being attached to said instrument on a surface thereof which vibrates in accordance with sound produced by playing of the instrument, said transducer comprising

(a) a capacitor microphone arrangment comprising
(i) a first electrode comprising an elongate foil of electrically conductive material;
(ii) a second electrode comprising an elongate foil of electrically conductive material overlying said first electrode;
and
(iii) a dielectric between said electrodes and electrically insulating them from one another;
(b) a housing of plastic material in which said microphone arrangement is received, said housing being mounted in intimate contact with said surface of said instrument, and adapted to transmit vibrations thereof to said capacitor microphone arrangement so as to produce relative movement of said electrodes in accordance with said vibrations;
and
(c) a sensing circuit connected to said electrodes, said circuit comprising means for applying a substantially constant potential difference to said electrodes, and means for amplifying oscillatory voltages established between said electrodes by said vibrations.

5 more elements

Dependencies are inferred from the claim text.

Electro-acoustic transducer

Life of this patent

Electro-acoustic transducer

Life of this patent

Abstract

Claims20