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US4449019A Expired / Lapsed US ⏱️ 0.0 years remaining

Piezoelectric loudspeaker

Assignee: Murata Manufacturing Co Ltd
•
Filing: 1981-11-09
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Granted: 1984-05-15
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Expires: 2001-11-09
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Abstract

Abstract A piezoelectric loudspeaker using a thin plate of piezoelectric ceramics of a high dielectric constant, and fixing a piezoelectric transducer including a thin plate of piezoelectric ceramic of a high dielectric constant onto a diaphragm stretched on a frame, thereby forming a sound generator. The piezoelectric loudspeaker is so constructed that the resonance frequency of the sound generator is set at the low frequency band side of an audio frequency region and that of a cavity by the frame is set at the high frequency band side, the thin plate piezoelectric ceramic of high dielectric constant being used, so that the piezoelectric loudspeaker is of an ultrathin type and can cover the whole audio frequency region.

Inventors

  • 👤 Sasuga Kakehi
  • 👤 Nobuhiko Nakagawa
  • 👤 Hideo Adachi
  • 👤 Tadashi Takaya

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 20:47
CPC Classifications
H; H04; H04R; H04R17/00

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 76 words
A piezoelectric loudspeaker having a piezoelectric transducer including a thin plate of piezoelectric ceramic of a high dielectric constant, said transducer being fixed to a diaphragm streteched onto frame, so that the resonance frequency of a sound generator comprising said piezoelectric transducer and diaphragm is set at a low frequency band side of an audio frequency region and the resonance frequency of a cavity formed by said frames is set at a high frequency band side.
Claim 2
Dependent Claim 76 words
A piezoelectric loudspeaker having a piezoelectric transducer including a thin plate of piezoelectric ceramic of a high dielectric constant, said transducer being fixed to a diaphragm streteched onto frame, so that the resonance frequency of a sound generator comprising said piezoelectric transducer and diaphragm is set at a low frequency band side of an audio frequency region and the resonance frequency of a cavity formed by said frames is set at a high frequency band side.
Claim 3
Dependent Claim 42 words
A piezoelectric loudspeaker according to claim 1, wherein said piezoelectric transducer is formed of a laminated member comprising said thin film piezoelectric ceramic of a high dielectric constant and an extremely thin metallic sheet, said laminated member being stuck onto said diaphragm.
Claim 4
Dependent Claim 29 words
A piezoelectric loudspeaker according to claim 1, wherein said frames comprises a first frame and a second frame, said diaphragm being sandwiched fixedly between said first and second frames.
Claim 5
Dependent Claim 17 words
A piezoelectric loudspeaker according to claim 1, wherein said diaphragm is formed of an epoxy resin film.
Claim 6
Dependent Claim 18 words
A piezoelectric loudspeaker according to claim 1, wherein said piezoelectric ceramic has a dielectric constant of about 3,500.

References Cited (Backward Citations)

US2718272A Cited
US3708702A Cited
JPS5535558A Cited
US4240002A Cited
EP0018614B1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-05-15 1987-11-14 1988-05-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-05-15 1991-11-14 1992-05-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-05-15 1995-11-14 1996-05-15 $7700.00 Window Closed / Lapsed

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