US 4,491,051 A · String instrument pickup system

Abstract

A string instrument pickup system sensitive to 360.degree. of transverse string movement, which is substantially immune from microphonics, and which has a substantially equal or balanced response to all of the strings. In one form of the invention a piezoelectric transducer is compressively associated with vertical movement components of each string of the instrument, but is laterally offset from a centered position under the string for compressive association of the transducer also with the horizontal string movement components; and halves of the total piezoelectric transducer area are oppositely polarized so as to cancel out microphonics. In a modular form of the invention a plurality of the piezoelectric transducers are supported in an elongated array by means of a flexible body of electrically insulative material and a pliable outer wrapping of metal foil so that the transducer is conformable to distortions and deformations in string saddle and bridge elements of the instrument between which the modular pickup is compressed whereby the transducers are made substantially uniformly responsive to the strings. In a presently preferred embodiment a two-section split saddle and uneven transverse positioning of crystals relative to strings for each saddle section provide substantially uniform response to all of the strings; and in this embodiment extremely small crystal areas minimize capacitive signal deterioration, and transversely very short crystals improve transverse string vibration response for substantially 360.degree. of transverse string movement sensitivity.

Claims14

Dependent claims

In a string instrument having a body with a generally flat upper portion and a plurality of strings spaced above and arranged generally parallel to said upper portion of the body of the instrument, a pickup which comprises:

a plurality of piezoelectric transducers spaced apart from each other and located generally between said plurality of strings and said upper portion of the body of the instrument and being responsive to compressional variations directed generally normal to said upper portion of the body of the instrument, each of said piezoelectric transducers having upper and lower parallel faces, the sum of the areas of all of said upper faces comprising an area of sensitivity substantially parallel to said upper portion of the body of the instrument, and
string support means compressionally engaged between said plurality of strings and said plurality of piezoelectric transducers so as to apply compressional variations to said piezoelectric transducers in response to movements of said strings in said generally normal direction, whereby said piezoelectric transducers are sensitive to such generally normal string movements,
substantially half of the total area of said area of sensitivity being electrically polarized in one direction, and substantially the other half of such total area being polarized in the opposite direction for cancellation of microphonics.

In a string instrument having a body with a generally flat upper portion and a plurality of strings spaced above and arranged generally parallel to each other and to said upper portion of the body of the instrument, a pickup which comprises:

a plurality of piezoelectric transducers arranged in an elongated array having a longitudinal axis generally parallel to said upper portion of the body of the instrument and generally transverse to said strings;
upwardly facing surface means on said upper portion of the body of the instrument upon which said transducers rest;
string support means compressionally engaged between said strings and said transducers so as to apply compressional variations to said transducers in response to movement of said strings;
and
transducer support means supporting said array of transducers in elongated, modular form, said transducer support means generally enclosing the tops, sides and bottoms of said transducers, and at least the upper portion of said support means above said transducers being pliable and thereby conformable to deformations in said string support means so as to provide substantially uniform responses of said transducers to said strings;
said transducer support means comprising an outer wrapping comprising electrically conductive metal foil;
said transducer support means comprising a body of flexible, electrically insulative material within which said piezoelectric transducers are located, said body having a plurality of cutout windows extending therethrough in the upward-downward direction and corresponding in number to the number of said transducers, each of said transducers being located in a respective said window;
said transducers each being generally flat, with upper and lower electrodes on opposite flat surfaces thereof which are generally parallel to said upper portion of the instrument body, said electrodes of each transducer being exposed on opposite sides of said pickup body, and
elongated upper and lower electrical contacts of generally flat, electrically conductive sheet material engaged generally flat against the respective said upper and lower electrodes of said transducers, at least one of said contacts being electrically insulated from said outer wrapping.

6 more elements

In a string instrument having a body with a generally flat upper portion and at least four strings spaced above and arranged generally parallel to each other and to said upper portion of the body of the instrument, a pickup system which comprises:

a plurality of piezoelectric transducers corresponding in number to said number of strings arranged in an elongated array having a longitudinal axis generally parallel to said upper portion of the body of the instrument and generally transverse to said strings;
upwardly facing surface means on said upper portion of the body of the instrument upon which said transducers rest with each of said transducers lying generally under a respective one of said strings;
and
elongated saddle means arranged generally parallel to said elongated array of transducers and engaged between said strings and said transducers so as to mechanically compressionally couple each of said transducers to its respective said string whereby compressional variations are applied to each of said transducers in response to movement of its respective said string;
said saddle means being transversely split into two elongated sections to increase the uniformity of response of said crystals to their respective said strings, one of said saddle sections being engaged between one plural sequence of said strings and their respective said transducers, and the other of said saddle sections being engaged between another plural sequence of said strings and their respective said transducers.

2 more elements

Dependencies are inferred from the claim text.

String instrument pickup system

Life of this patent

String instrument pickup system

Life of this patent

Abstract

Claims14