EP0414479A2 - Hochkomplianter Kopfhörertreiber - Google Patents

Hochkomplianter Kopfhörertreiber Download PDF

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Publication number
EP0414479A2
EP0414479A2 EP90309125A EP90309125A EP0414479A2 EP 0414479 A2 EP0414479 A2 EP 0414479A2 EP 90309125 A EP90309125 A EP 90309125A EP 90309125 A EP90309125 A EP 90309125A EP 0414479 A2 EP0414479 A2 EP 0414479A2
Authority
EP
European Patent Office
Prior art keywords
diaphragm
driver
headset according
voice coil
compliance
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP90309125A
Other languages
English (en)
French (fr)
Other versions
EP0414479A3 (en
EP0414479B1 (de
Inventor
Roman Sapiejewski
John J. Breen
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bose Corp
Original Assignee
Bose Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=23574122&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP0414479(A2) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Bose Corp filed Critical Bose Corp
Publication of EP0414479A2 publication Critical patent/EP0414479A2/de
Publication of EP0414479A3 publication Critical patent/EP0414479A3/en
Application granted granted Critical
Publication of EP0414479B1 publication Critical patent/EP0414479B1/de
Anticipated expiration legal-status Critical
Revoked legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/10—Earpieces; Attachments therefor ; Earphones; Monophonic headphones
    • H04R1/1083—Reduction of ambient noise
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1785—Methods, e.g. algorithms; Devices
    • G10K11/17857—Geometric disposition, e.g. placement of microphones
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1785—Methods, e.g. algorithms; Devices
    • G10K11/17861—Methods, e.g. algorithms; Devices using additional means for damping sound, e.g. using sound absorbing panels
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1787—General system configurations
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/10—Applications
    • G10K2210/108—Communication systems, e.g. where useful sound is kept and noise is cancelled
    • G10K2210/1081—Earphones, e.g. for telephones, ear protectors or headsets
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/30—Means
    • G10K2210/321—Physical
    • G10K2210/3217—Collocated sensor and cancelling actuator, e.g. "virtual earth" designs
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/10—Earpieces; Attachments therefor ; Earphones; Monophonic headphones
    • H04R1/1008—Earpieces of the supra-aural or circum-aural type

Definitions

  • the present invention relates to high compliance drivers in active noise reducing headsets. Particularly. it relates to an apparatus for protecting the driver diaphragm.
  • a headset comprises at least one earcup having a front and rear cavity, a baffle separating the front and rear cavities, a high compliance driver having a diaphragm joined to a voice coil normally residing in a gap mounted on the baffle, and an active noise reduction system.
  • a limiting structure limits the maximum excursion of the diaphragm.
  • Indentations may be provided on the diaphragm.
  • the indentations may have a component transverse to the circular grooves or corrugations near the diaphragm periphery.
  • the invention includes a baffle 11 that separates a front or inside cavity from a rear or outside cavity and carries a high compliance driver 13 having a diaphragm 14.
  • Plastics fingers 15 are equi­angularly spaced about the driver axis, extend radially inward and are positioned along the driver axial direction of motion so as to limit displacement of the diaphragm 14 from its centre or rest position to a plane sufficiently close to the rest plane with the diaphragm 14 centred so that a portion of the voice coil is always in the air gap and sufficiently far from the central plane so that the diaphragm 14 is free to translate axially without obstruction when normally reproducing sound with the headphones properly mounted on the head of the user.
  • An active noise reduction system mounting structure 16 carries a microphone (not shown) near the diaphragm 14 used with associated electronic circuitry comprising a system corresponding substantially to the active noise reducing system disclosed in US-A-4644581 and US-A-4455675, incorporated herein by reference.
  • the effective air volume which determines this transmission attenuation is not simply the volume of the front cavity but also a function of the driver compliance (below its free air resonance frequency) and the volume of the rear cavity. If C f is the compliance of the front cavity air volume, C r is the compliance of the rear cavity air volume and C d is the compliance of the driver, then the effective compliance C eff determining passive transmission attenuation is the front cavity compliance in series with the parallel combination of the driver compliance and the rear cavity compliance, i.e. below the free air resonance of the driver.
  • High compliance herein means the driver compliance is greater than the rear cavity compliance.
  • the over-pressure generated can cause the thin, flexible diaphragm to collapse from its normal shape.
  • Drivers with diaphragms formed from thin plastics films usually are formed with angled grooves or corrugations in the outer annulus between the voice coil and the edge of the diaphragm. These grooves expand and contract as the voice coil moves and help ensure linear, piston-like motion. Under the over-­pressure conditions described above, these grooves may irreversibly change shape, and prevent the driver diaphragm from returning to its normal shape and position.
  • the invention avoids the suction or under-pressure problem by locating a structure in the earcup over the diaphragm 14 to limit voice coil excursion.
  • This structure 15 is positioned such that, during the normal range of excursion of the driver diaphragm, the diaphragm 14 does not touch the structure 15 and its motion is unimpeded.
  • the structure 15 is located close enough to the driver 13 such that it contacts the diaphragm 14 before it is pulled so far that the voice coil is pulled fully from the gap. Since the voice coil is not pulled from the gap, when the suction is released, the coil will return to its normal rest position and not hang up on the basket.
  • the structure 15 is preferably small enough so that it does not cause diffraction or otherwise affect the sound pressure detected by the active noise reduction system's microphone except at high frequencies (above 10KHz).
  • the present invention accomplishes this by using three small fingers of plastics 15 positioned to symmetrically contact the diaphragm 14 along the circle where the voice coil is glued to it. Contacting the diaphragm 14 with small point-like fingers anywhere but along the voice coil might risk possibly puncturing or otherwise damaging the diaphragm.
  • An alternative embodiment for the structure 15 to stop diaphragm motion is a fine wire mesh screen (shown in part in the drawing) shaped so as to contact as much of the surface of the diaphragm 14 as possible at its position of maximum allowed outward excursion. By contacting over a large area, the pressure at any point is small enough so as not to damage the driver.
  • the present invention avoids the driver collapse or over-pressure problem by using a driver whose diaphragm 14 recovers its shape when collapsed.
  • Changing the shape of the groove or corrugations by including indentations 17, having a radial component in the diaphragm 14 such that the diaphragm 14 recovers its shape if collapsed prevents unrecoverable collapse.
  • An alternative solution is to change the shape of the metal basket to which the diaphragm 14 is attached or to add a structure to the basket. Commonly the basket surface under the diaphragm 14 is flat. By raising this surface at some points it can be made to support the diaphragm 14 in over-pressure situations, preventing it from collapsing to the point that permanent damage or change in shape occurs.
  • a preferred form of the invention involves combining the driver mounting structure, active noise reduction system microphone mounting structure, and driver under-­pressure excursion stops into a single plastics piece moulded in one shot. This approach reduces the effect of mechanical tolerance build-up and positions all parts accurately so as to provide consistent performance. This structure could be further combined with the baffle separating front and rear cavities.
  • the limitation structure or elements 15 limit the excursion of the diaphragm 14 so that the voice coil does not escape the air gap. This structure ensures that the diaphragm 14 will return to its nominal position. These limitation elements 15 do not interfere with the normal range of motion of diaphragm 14.
  • the grooves 17 in the surface of diaphragm 14 cause the diaphragm 14 to recover its original shape if collapsed by the increase in pressure.
  • raised points on the basket surface underneath the diaphragm 14 support it during over-pressure situations preventing a collapse.
  • the front cavity volume is approximately 100cc (cubic centimetres), and the rear cavity volume is also 100cc.
  • the driver has a free air resonance of 250 Hz and an acoustical compliance of 1x10 ⁇ 9 m5N ⁇ 1. This compliance is equivalent to a volume of 150cc of air. The effective volume is thus
  • the driver diaphragm 14 is formed of mylar which is approximately 25.4x10 ⁇ 6 m (1 mil) thick.
  • the driver is mounted in a plastics baffle 11 with three under-pressure excursion stops 15 placed to contact the diaphragm 14 at approximately 7.62x10 ⁇ 4 m (30 mils) excursion. Under maximum operating conditions (high noise and communication levels), driver excursion does not exceed approximately 5.1 x 10 ⁇ 4m (20 mils).
  • Rear cavity port tuning is set to 90 Hz. Port tuning is chosen based on need for increased driver output for noise cancellation in 50 - 80 Hz range without compromising passive attenuation. A much larger rear cavity would eliminate the need for a port in the rear cavity, but would compromise styling.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Headphones And Earphones (AREA)
  • Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)
  • Electroluminescent Light Sources (AREA)
EP90309125A 1989-08-23 1990-08-21 Hochkomplianter Kopfhörertreiber Revoked EP0414479B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US39813389A 1989-08-23 1989-08-23
US398133 1989-08-23

Publications (3)

Publication Number Publication Date
EP0414479A2 true EP0414479A2 (de) 1991-02-27
EP0414479A3 EP0414479A3 (en) 1991-11-06
EP0414479B1 EP0414479B1 (de) 1995-09-27

Family

ID=23574122

Family Applications (1)

Application Number Title Priority Date Filing Date
EP90309125A Revoked EP0414479B1 (de) 1989-08-23 1990-08-21 Hochkomplianter Kopfhörertreiber

Country Status (5)

Country Link
EP (1) EP0414479B1 (de)
JP (1) JP3268774B2 (de)
AT (1) ATE128592T1 (de)
CA (1) CA2023142A1 (de)
DE (1) DE69022672T2 (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9654854B2 (en) 2011-06-01 2017-05-16 Paul Darlington In-ear device incorporating active noise reduction
EP3171612A1 (de) 2015-11-19 2017-05-24 Parrot Drones Audio-headset mit aktiver geräuschkontrolle, anti-okklusionskontrolle und löschung der passiven schalldämpfung je nach vorliegen oder nicht-vorliegen einer stimmaktivität des headset-benutzers
US9818394B2 (en) 2009-11-30 2017-11-14 Graeme Colin Fuller Realisation of controller transfer function for active noise cancellation

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8571227B2 (en) 2005-11-11 2013-10-29 Phitek Systems Limited Noise cancellation earphone
NZ584418A (en) 2007-10-02 2012-12-21 Phitek Systems Ltd Component for noise reducing earphone
WO2011146429A1 (en) 2010-05-17 2011-11-24 Thales Avionics, Inc. Airline passenger seat modular user interface device
US9487295B2 (en) 2010-11-15 2016-11-08 William James Sim Vehicle media distribution system using optical transmitters
TWI551152B (zh) * 2013-05-08 2016-09-21 寶德科技股份有限公司 具有被動音膜的耳機
CN106105257B (zh) * 2014-03-17 2019-12-03 博士有限公司 具有线性压力均衡端口的耳机

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1807225A (en) * 1928-03-09 1931-05-26 Utah Radio Products Company In Sound propagating diaphragm
NL257376A (de) * 1959-10-29
US4581496A (en) * 1979-09-04 1986-04-08 Emhart Industries, Inc. Diaphragm for attenuating harmonic response in an electroacoustic transducer
NL8202529A (nl) * 1982-06-23 1984-01-16 Philips Nv Elektro-akoestische omzetter met een lange slag.
GB8506860D0 (en) * 1985-03-16 1985-04-17 Plessey Co Plc Noise reduction arrangements
GB8607047D0 (en) * 1986-03-21 1986-04-30 Univ Southampton Acoustic noise reduction

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9818394B2 (en) 2009-11-30 2017-11-14 Graeme Colin Fuller Realisation of controller transfer function for active noise cancellation
US9654854B2 (en) 2011-06-01 2017-05-16 Paul Darlington In-ear device incorporating active noise reduction
EP3171612A1 (de) 2015-11-19 2017-05-24 Parrot Drones Audio-headset mit aktiver geräuschkontrolle, anti-okklusionskontrolle und löschung der passiven schalldämpfung je nach vorliegen oder nicht-vorliegen einer stimmaktivität des headset-benutzers

Also Published As

Publication number Publication date
CA2023142A1 (en) 1991-02-24
ATE128592T1 (de) 1995-10-15
DE69022672D1 (de) 1995-11-02
JPH03165694A (ja) 1991-07-17
DE69022672T2 (de) 1996-03-07
EP0414479A3 (en) 1991-11-06
JP3268774B2 (ja) 2002-03-25
EP0414479B1 (de) 1995-09-27

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