Patent US4807294A successfully refreshed from Google Patents.
US4807294A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Piezoelectric and foam resin sheet speaker
Assignee: Mitsubishi Chemical Corp
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Filing: 1987-06-17
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Granted: 1989-02-21
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Expires: 2007-06-17
Abstract
Abstract A sheet speaker comprised of a planar piezoelectric ceramic sheet encapsulated in a planar sheet of hard resin foam, comprised of a polystyrene, urethane, urea or phenolic. The planar piezoelectric ceramic sheet is centered in the planar hard resin from sheet which provides a surface area of 10-50 times the surface area of the planar piezoelectric sheet. The surface of the planar hard resin foam may be lined with cloth, paper, or plastic film.
Inventors
- 👤 Yoichi Iwata
- 👤 Nubuo Tanaka
- 👤 Junichi Katurayama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:06
CPC Classifications
H; H04; H04R; H04R17/00; H04R7/00; H04R7/02; H04R7/04; H04R7/06; H04R2307/00; H04R2307/029
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
76 words
A sheet speaker assembly comprising; a planar piezoelectric ceramic sheet; a planar hard resin foam sheet surrounding and encapsulating said planar piezoelectric ceramic sheet; said planar piezoelectric sheet being approximately at the center of said planar hard resin foam sheet; said planar hard resin foam sheet having a surface area approximately at least ten times the surface area of said planar piezoelectric ceramic sheet whereby said assembly provides a sheet speaker having high acoustic output power.
Claim 2
Dependent Claim
76 words
A sheet speaker assembly comprising; a planar piezoelectric ceramic sheet; a planar hard resin foam sheet surrounding and encapsulating said planar piezoelectric ceramic sheet; said planar piezoelectric sheet being approximately at the center of said planar hard resin foam sheet; said planar hard resin foam sheet having a surface area approximately at least ten times the surface area of said planar piezoelectric ceramic sheet whereby said assembly provides a sheet speaker having high acoustic output power.
Claim 3
Dependent Claim
37 words
The assembly according to claim 1 in which said planar hard resin sheet is formed of a resin foam selected from the group consisting of polystyrene foam, urethane resin foam, urea resin foam and phenolic resin foam.
Claim 4
Dependent Claim
27 words
The assembly according to claim 2 in which said resin foam for forming said planar hard resin sheet has an expansion ratio of approximately 10 to 80.
Claim 5
Dependent Claim
16 words
The assembly according to claim 3 in which said expansion ratio is approximately 10 to 50.
Claim 6
Dependent Claim
29 words
The assembly according to claim 1 in which the planar surfaces of said planar hard resin foam sheet are covered with a lining of cloth, paper, or plastic film.
Claim 7
Dependent Claim
33 words
The assembly according to claim 1 in which the surface area of said planar hard foam resin sheet is approximately at least fifty times the surface area of said planar piezoelectric ceramic sheet.
Claim 8
Dependent Claim
29 words
The assembly according to claim 6 in which said planar hard resin foam sheet has a thickness which is approximately in the range of 2 mm to 100 mm.
Claim 9
Dependent Claim
27 words
The assembly according to claim 16 in which said hard resin foam sheet has a thickness which is in the range of 5 mm to 50 mm.
Claim 10
Dependent Claim
25 words
The assembly according to claim 6 in which said planar hard resin foam has a tensile elastic modulus approximately greater than 1×10 dyne/cen 2 .
Claim 11
Dependent Claim
19 words
The assembly according to claim 9 in which said tensile elastic modulus is greater that 1.5×10 dyne/cm 2 .
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-02-21 | 1992-08-22 | 1993-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-21 | 1996-08-22 | 1997-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-21 | 2000-08-22 | 2001-02-21 | $7700.00 | Window Closed / Lapsed |