Browse Prior Art Database

Improved Use of Peizo Electric Speaker Drive Unit

IP.com Disclosure Number: IPCOM000115462D
Original Publication Date: 1995-May-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Knox, AR: AUTHOR [+2]

Abstract

Disclosed are methods whereby the effectiveness of peizoelectric crystals when configured as a loudspeaker element may be improved.

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Improved Use of

Peizo Electric Speaker Drive

Unit

       Application of peizo transducer to a monitor bezel.

      Disclosed are methods whereby the effectiveness of
peizoelectric crystals when configured as a loudspeaker element may
be improved.

      The peizo speakers described are formed by the crystalline
material being sandwiched between a pair of conductive plates.  The
resultant structure is about the size and thickness of a credit card.
Wires are simply soldered to each side of the structure to provide
electrical connection from the signal source.

      In operation, an electrical signal causes the crystal to expand
or contract, depending on the polarity, with an amplitude that is
proportional to the applied voltage.  This expansion and contraction
causes the faces of the structure to act like a diaphragm, causing
pulsations in the air in the same manner as a conventional speaker.

      A problem with this simple structure is that the radiation
efficiency is low due to small surface area and the equal expansion
and contraction of the crystal about the center line.  A solution for
improved efficiency is to place the peizo elements on a massive base
and attach a second light plate to the outward facing side of the
element to improve the radiation efficiency.  This external plate may
also be used to provide an acceptable industrial design appearance.
A number of elements may be coupled to the same plate for increased
power handling or, for...