US3849602A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Earphone with frequency correction
Assignee: Individual
•
Filing: 1971-12-23
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Granted: 1974-11-19
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Expires: 1991-12-23
Abstract
Abstract Each earphone of a stereo headset comprises an electroacoustic transducer with an audio-frequency signal applied to its input. The electroacoustic transducer is provided with an electric filter connected in series in the current path of the audiofrequency signal and the filter has frequency characteristics which, added to the frequency characteristic of transducer radiation, compensate for frequency attenuation of the high and low end thereof and provide a linear overall radiation characteristic within the assigned frequency band.
Inventors
- 👤 G Gendin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:04
CPC Classifications
H; H04; H04R; H04R3/00; H04R3/04
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
105 words
An earphone comprising a case; an electroacoustic transducer adapted to reproduce sound in the audio frequency range, said transducer having an input for receiving an audio-frequency signal; an electric filter accommodated in said case and connected in series in the transmission path of said audiofrequency signal, said transducer having a mid-band frequency of about 1,000 Hz and attenuated output in both high and low frequency ranges, said filter being effective in the mid-band frequency of the transducer for attenuating said mid-band frequency to compensate for the attenuation of low and high frequencies and provide a substantially linear overall radiation characteristic within the assigned audio-frequency band.
Claim 2
Dependent Claim
105 words
An earphone comprising a case; an electroacoustic transducer adapted to reproduce sound in the audio frequency range, said transducer having an input for receiving an audio-frequency signal; an electric filter accommodated in said case and connected in series in the transmission path of said audiofrequency signal, said transducer having a mid-band frequency of about 1,000 Hz and attenuated output in both high and low frequency ranges, said filter being effective in the mid-band frequency of the transducer for attenuating said mid-band frequency to compensate for the attenuation of low and high frequencies and provide a substantially linear overall radiation characteristic within the assigned audio-frequency band.
Claim 3
Dependent Claim
83 words
An earphone as claimed in claim 1 wherein said transducer is mounted in said case and has a radiating portion of given diameter, a ring secured in said case and mounting said transducer, said ring having an opening with a diameter equal to the diameter of said radiating portion of the transducer, and a seal on said ring and having an opening with a diameter equal to the opening in said ring, said opening in the ring and seal forming a sound chamber.
Claim 4
Dependent Claim
25 words
An earphone as claimed in claim 1 wherein said filter comprises two resistors connected in series, and a capacitor connected in parallel with said resistors.
Claim 5
Dependent Claim
26 words
An earphone as claimed in claim 3 wherein said filter further comprises a second capacitor connected to the junction of the series-connected resistors and to ground.
Claim 6
Dependent Claim
15 words
An earphone as claimed in claim 1 wherein said transducer is a miniature electrodynamic speaker.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-18 | 1978-05-20 | 1978-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-18 | 1982-05-20 | 1982-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-18 | 1986-05-20 | 1986-11-19 | $7700.00 | Window Closed / Lapsed |