Patent US4924962A successfully refreshed from Google Patents.
US4924962A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sound reproducing apparatus for use in vehicle
Assignee: Panasonic Holdings Corp
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Filing: 1987-07-10
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Granted: 1990-05-15
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Expires: 2007-07-10
Abstract
Abstract A sound reproducing apparatus for use in a vehicle having a speaker system constituted by at least one acoustic duct and a speaker unit disposed at a throat of the acoustic duct, an opening formed at the other end of the acoustic duct facing the passenger compartment of a vehicle. The apparatus is arranged such that, F0 and Fs are substantially equal to each other. Where Fs is the lowest frequency in a frequency range within which the imaginary part of the acoustic impedance at the sound radiating surface of the speaker system in the direction of the space within the passsenger compartment is zero and F0 is the low-range resonance frequency of the speaker system itself in the free space.
Inventors
- 👤 Kenichi Terai
- 👤 Shuji Saiki
- 👤 Kousaku Murata
- 👤 Katsuaki Satoh
- 👤 Yoichi Kumura
- 👤 Yasutoshi Nakama
- 👤 Michiko Ogawa
- 👤 Shuichi Obata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:13
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/22; H04R1/28; H04R1/2807; H04R1/2853; H04R1/2857; H04R1/2838; H04R1/2842; H04R1/2861; H04R1/2865
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
162 words
A speaker system for use in a closed space, comprising: at least one speaker unit having sidewalls, sound producing means, and a sound radiation surface; said sound radiation surface being disposed at a predetermined location in said closed space, said predetermined location having an acoustic impedance within said closed space which has an imaginary component equal to zero at a frequency Fs, said frequency Fs being a lowest frequency at which said acoustic impedance has an imaginary component which is zero, said speaker unit operating in said closed space with a relatively flat sound pressure frequency response in a low-frequency range below said frequency Fs, whereby said speaker unit has a first, low-range resonance frequency FO when in a free-field space, said first, low-range resonance frequency FO of said speaker unit being substantially equal to said frequency Fs, wherein sound distortion caused by vibration of said speaker unit is reduced in a low frequency range in a vicinity of said frequency Fs.
Claim 2
Dependent Claim
162 words
A speaker system for use in a closed space, comprising: at least one speaker unit having sidewalls, sound producing means, and a sound radiation surface; said sound radiation surface being disposed at a predetermined location in said closed space, said predetermined location having an acoustic impedance within said closed space which has an imaginary component equal to zero at a frequency Fs, said frequency Fs being a lowest frequency at which said acoustic impedance has an imaginary component which is zero, said speaker unit operating in said closed space with a relatively flat sound pressure frequency response in a low-frequency range below said frequency Fs, whereby said speaker unit has a first, low-range resonance frequency FO when in a free-field space, said first, low-range resonance frequency FO of said speaker unit being substantially equal to said frequency Fs, wherein sound distortion caused by vibration of said speaker unit is reduced in a low frequency range in a vicinity of said frequency Fs.
Claim 3
Dependent Claim
41 words
A speaker system as set forth in claim 1, wherein said speaker unit includes duct means, wherein said speaker means are disposed at one end of said duct means, another end of said duct means being open to said closed space.
Claim 4
Dependent Claim
20 words
A speaker system as set forth in claim 1, wherein said closed space is a passenger compartment of a vehicle.
Claim 5
Dependent Claim
20 words
A speaker system as set forth in claim 2, wherein said acoustic duct has a plurality of partitions disposed therein.
Claim 6
Dependent Claim
23 words
A speaker system as set forth in claim 2, wherein said acoustic duct is a portion of a body structure of said vehicle.
Claim 7
Dependent Claim
25 words
A speaker system as set forth in claim 2, wherein one end of said acoustic duct is opened to a door portion of said vehicle.
Claim 8
Dependent Claim
32 words
A speaker system as set forth in claim 3, wherein said speaker unit is disposed in one of (a) a trunk portion and (b) a rear parcel compartment portion of said vehicle.
Claim 9
Dependent Claim
158 words
A speaker system for use in a closed space, comprising: at least one speaker unit having sidewalls, sound producing means, and a sound radiation surface; said sound radiation surface being disposed at a predetermined location in said closed space, said predetermined location having an acoustic impedance within said closed space which has an imaginary component equal to zero at a frequency Fs, said frequency Fs being a lowest frequency at which said acoustic impedance has an imaginary component which is zero, said speaker unit operating in said closed space with a relatively flat sound pressure frequency response in a low-frequency range below said frequency Fs, and a duct, said duct having a length L1 along a centerline thereof, whereby L1 satisfies a condition C/(4Fs)≦L1≦C/(2Fs) where C is an acoustic compliance of said closed space, wherein sound distortion caused by vibration of said speaker unit is reduced in a low frequency range in a vicinity of said frequency Fs.
Claim 10
Dependent Claim
158 words
A speaker system for use in a closed space, comprising: at least one speaker unit having sidewalls, sound producing means, and a sound radiation surface; said sound radiation surface being disposed at a predetermined location in said closed space, said predetermined location having an acoustic impedance within said closed space which has an imaginary component equal to zero at a frequency Fs, said frequency Fs being a lowest frequency at which said acoustic impedance has an imaginary component which is zero, said speaker unit operating in said closed space with a relatively flat sound pressure frequency response in a low-frequency range below said frequency Fs, and a duct, said duct having a length L1 along a centerline thereof, whereby L1 satisfies a condition C/(4Fs)≦L1≦C/(2Fs) where C is an acoustic compliance of said closed space, wherein sound distortion caused by vibration of said speaker unit is reduced in a low frequency range in a vicinity of said frequency Fs.
Claim 11
Dependent Claim
20 words
A speaker system as set forth in claim 8, wherein said duct means has a plurality of partitions disposed therein.
Claim 12
Dependent Claim
20 words
A speaker system as set forth in claim 8, wherein said closed space is a passenger compartment of a vehicle.
Claim 13
Dependent Claim
23 words
A speaker system as set forth in claim 10, wherein said duct means is a portion of a body structure of said vehicle.
Claim 14
Dependent Claim
25 words
A speaker system as set forth in claim 10, wherein one end of said duct means is open to a door portion of said vehicle.
Claim 15
Dependent Claim
32 words
A speaker system as set forth in claim 10, wherein said speaker unit is disposed in one of (a) a trunk portion and (b) a rear parcel compartment portion of said vehicle.
Claim 16
Dependent Claim
188 words
A speaker system for use in a closed space, comprising at least one speaker unit having sidewalls, sound producing means, and a sound radiation surface; said sound radiation surface being disposed in said closed space at a predetermined location, said predetermined location having an acoustic impedance within said closed space which has an imaginary component equal to zero at a frequency Fs, said frequency Fs being a lowest frequency at which said acoustic impedance has an imaginary component which is zero, said speaker unit operating in said closed space with a relatively flat sound pressure frequency response in a low-frequency range below said frequency Fs, a first duct disposed in front of said sound producing means, and a second duct means disposed at a rear of said sound producing means, whereby said first and second ducts have respective lengths along respective centerlines thereof which differ by a length L2 which satisfies a condition C/(4Fs)≦L2≦C/(2Fs) where C is an acoustic compliance of said closed space, wherein sound distortion caused by vibration of said speaker unit is reduced in a low frequency range in a vicinity of said frequency Fs.
Claim 17
Dependent Claim
188 words
A speaker system for use in a closed space, comprising at least one speaker unit having sidewalls, sound producing means, and a sound radiation surface; said sound radiation surface being disposed in said closed space at a predetermined location, said predetermined location having an acoustic impedance within said closed space which has an imaginary component equal to zero at a frequency Fs, said frequency Fs being a lowest frequency at which said acoustic impedance has an imaginary component which is zero, said speaker unit operating in said closed space with a relatively flat sound pressure frequency response in a low-frequency range below said frequency Fs, a first duct disposed in front of said sound producing means, and a second duct means disposed at a rear of said sound producing means, whereby said first and second ducts have respective lengths along respective centerlines thereof which differ by a length L2 which satisfies a condition C/(4Fs)≦L2≦C/(2Fs) where C is an acoustic compliance of said closed space, wherein sound distortion caused by vibration of said speaker unit is reduced in a low frequency range in a vicinity of said frequency Fs.
Claim 18
Dependent Claim
25 words
A speaker system as set forth in claim 14, wherein each of said first and second duct means has a plurality of partitions disposed therein.
Claim 19
Dependent Claim
20 words
A speaker system as set forth in claim 15, wherein said closed space is a passenger compartment of a vehicle.
Claim 20
Dependent Claim
29 words
A speaker system as set forth in claim 15, wherein said first and second duct means are each formed by a portion of a body structure of a vehicle.
Claim 21
Dependent Claim
30 words
A speaker system as set forth in claim 16, wherein one end of each of said first and second acoustic ducts is open to a door portion of said vehicle.
Claim 22
Dependent Claim
32 words
A speaker system as set forth in claim 16, wherein said speaker unit is disposed in one of (a) a trunk portion and (b) a rear parcel compartment portion of said vehicle.
Claim 23
Independent Claim
154 words
A method of reducing sound distortion of a speaker system for use in a closed space, comprising the steps of: selecting a location within the closed space for mounting a speaker unit; determining an acoustical impedance at said location within said closed space at a low-range frequency Fs having an imaginary component equal to zero, said frequency Fs being a lowest frequency at which the imaginary component of said acoustic impedance is zero, selecting the speaker unit that has sidewalls, sound producing means, and a sound radiation surface such that, when disposed in said closed space at said location said speaker unit would be characterized by having a first, low-range resonant frequency FO when in a free-field room, wherein said first, low-range resonant frequency FO is equal to frequency Fs, and sound distortion caused by vibration of said speaker unit is reduced in a low frequency range in a vicinity of said frequency Fs.
Claim 24
Independent Claim
154 words
A method of reducing sound distortion of a speaker system for use in a closed space, comprising the steps of: selecting a location within the closed space for mounting a speaker unit; determining an acoustical impedance at said location within said closed space at a low-range frequency Fs having an imaginary component equal to zero, said frequency Fs being a lowest frequency at which the imaginary component of said acoustic impedance is zero, selecting the speaker unit that has sidewalls, sound producing means, and a sound radiation surface such that, when disposed in said closed space at said location said speaker unit would be characterized by having a first, low-range resonant frequency FO when in a free-field room, wherein said first, low-range resonant frequency FO is equal to frequency Fs, and sound distortion caused by vibration of said speaker unit is reduced in a low frequency range in a vicinity of said frequency Fs.
Claim 25
Dependent Claim
43 words
A method as set forth in claim 20, further comprising the following steps: providing at least one acoustic duct, and disposing said speaker unit at one end of said duct, another end of said acoustic duct being in communication with said closed space.
Claim 26
Dependent Claim
19 words
A method as set forth in claim 20, wherein said closed space is a passenger compartment of a vehicle.
Claim 27
Dependent Claim
22 words
A method as set forth in claim 21, further comprising the step of disposing a plurality of partitions in said acoustic duct.
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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) | 1993-05-14 | 1993-11-13 | 1994-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-14 | 1997-11-13 | 1998-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-14 | 2001-11-13 | 2002-05-15 | $7700.00 | Window Closed / Lapsed |