Patent US1679891A successfully refreshed from Google Patents.
US4239945A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sealed headphone
Assignee: Panasonic Holdings Corp
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Filing: 1977-12-12
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Granted: 1980-12-16
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Expires: 1997-12-12
Abstract
Abstract A sealed headphone having an improved sound pressure versus frequency response characteristic is disclosed. The sealed headphone comprises a mounting plate having coupling apertures, an electro-acoustic transducer attached to one side of the mounting plate and a casing covering the transducer. A space defined by the rear side of the transducer and the casing communicates via the coupling apertures with another spaced formed on the opposite side of the mounting plate so as to form an acousto-mechanical resonance circuit within the headphone. By raising the parallel resonance frequency of the resonance circuit, a higher reproduced frequency limit of the headphone is achieved.
Inventors
- 👤 Nobuhisa Atoji
- 👤 Shoichi Kusomoto
- 👤 Kazue Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:29
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/22; H04R1/28; H04R1/2807; H04R1/2815; H04R1/2819; H04R1/10; H04R1/1008
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
195 words
A sealed headphone comprising: a pad attached to a front side of a mounting plate having sound apertures formed therethrough, an electro-acoustic transducer having a vibrating element for emitting sounds from the front and rear surface of said element attached to a rear side of said mounting plate, a sound sealed casing covering the rear side of said electro-acoustic transducer to provide an enclosed rear space within said casing which receives sounds emitted from the rear surface of said element, first coupling apertures provided in said mounting plate for coupling the rear space within said casing with a front listening space in front of said mounting plate, said sound apertures channeling sound generated from a front surface of said vibrating element of said electro-acoustic transducer forwardly into said front listening space, and said first coupling apertures channeling sound generated from a rear surface of said vibrating element within said casing into said front listening space, and an acoustic-mechanical resonance circuit for improving the high frequency response of said headphone consisting of a volume compliance of said front space, a different volume compliance of said rear space and an acoustic mass reactance of said coupling apertures.
Claim 2
Dependent Claim
195 words
A sealed headphone comprising: a pad attached to a front side of a mounting plate having sound apertures formed therethrough, an electro-acoustic transducer having a vibrating element for emitting sounds from the front and rear surface of said element attached to a rear side of said mounting plate, a sound sealed casing covering the rear side of said electro-acoustic transducer to provide an enclosed rear space within said casing which receives sounds emitted from the rear surface of said element, first coupling apertures provided in said mounting plate for coupling the rear space within said casing with a front listening space in front of said mounting plate, said sound apertures channeling sound generated from a front surface of said vibrating element of said electro-acoustic transducer forwardly into said front listening space, and said first coupling apertures channeling sound generated from a rear surface of said vibrating element within said casing into said front listening space, and an acoustic-mechanical resonance circuit for improving the high frequency response of said headphone consisting of a volume compliance of said front space, a different volume compliance of said rear space and an acoustic mass reactance of said coupling apertures.
Claim 3
Dependent Claim
19 words
A sealed headphone according to claim 1 wherein said acoustic-mechanical resonance circuit has a resonance frequency near 5 KHz.
Claim 4
Dependent Claim
17 words
A sealed headphone according to claim 1 wherein a diaphragm is applied over said first coupling apertures.
Claim 5
Dependent Claim
38 words
A sealed headphone according to claim 1 wherein the rear space within the casing is divided into two parts by a partitioning element and the divided parts are coupled by second coupling apertures formed through said partitioning element.
Claim 6
Dependent Claim
37 words
A sealed headphone according to claim 4 wherein said partitioning element and first and second coupling apertures are configured to provide said headphone with a dual-peak frequency characteristic having two peaks between 2 KHz and 6 KHz.
Claim 7
Dependent Claim
196 words
A sealed headphone comprising: a mounting plate having sound apertures and coupling apertures formed therein, a pad attached to a front side of said mounting plate, an electro-acoustic transducer attached to a rear side of said mounting plate and having a vibrating element at a front side thereof emitting sounds through said sound apertures and sound passing holes communicating with the rear side of said vibrating element provided at a rear side thereof, a sound sealed casing attached to the rear side of said mounting plate to enclose said transducer and receive sounds passing through said sound passing holes thereby forming a rear space defined by the rear side of said transducer and said casing, said rear space communicating with a listening space at the front side of said mounting plate through said coupling apertures, and an acoustic-mechanical resonance circuit for improving the high frequency response of said headphone consisting of a volume compliance of said rear space, a volume compliance of said listening space provided in front of said mounting plate and an acoustic mass reactance of said coupling apertures, said resonance circuit having a parallel resonance frequency defining the high limit of reproduced frequencies.
Claim 8
Dependent Claim
196 words
A sealed headphone comprising: a mounting plate having sound apertures and coupling apertures formed therein, a pad attached to a front side of said mounting plate, an electro-acoustic transducer attached to a rear side of said mounting plate and having a vibrating element at a front side thereof emitting sounds through said sound apertures and sound passing holes communicating with the rear side of said vibrating element provided at a rear side thereof, a sound sealed casing attached to the rear side of said mounting plate to enclose said transducer and receive sounds passing through said sound passing holes thereby forming a rear space defined by the rear side of said transducer and said casing, said rear space communicating with a listening space at the front side of said mounting plate through said coupling apertures, and an acoustic-mechanical resonance circuit for improving the high frequency response of said headphone consisting of a volume compliance of said rear space, a volume compliance of said listening space provided in front of said mounting plate and an acoustic mass reactance of said coupling apertures, said resonance circuit having a parallel resonance frequency defining the high limit of reproduced frequencies.
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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) | 1983-12-16 | 1984-06-16 | 1984-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-16 | 1988-06-16 | 1988-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-16 | 1992-06-16 | 1992-12-16 | $7700.00 | Window Closed / Lapsed |