US3908095A - Microphone-speaker device - Google Patents

Microphone-speaker device Download PDF

Info

Publication number
US3908095A
US3908095A US289746A US28974672A US3908095A US 3908095 A US3908095 A US 3908095A US 289746 A US289746 A US 289746A US 28974672 A US28974672 A US 28974672A US 3908095 A US3908095 A US 3908095A
Authority
US
United States
Prior art keywords
sound
reflector
casing
transducer
focus
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.)
Expired - Lifetime
Application number
US289746A
Other languages
English (en)
Inventor
Sei Jinsenji
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.)
Ricoh Co Ltd
Original Assignee
Ricoh Co Ltd
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
Application filed by Ricoh Co Ltd filed Critical Ricoh Co Ltd
Application granted granted Critical
Publication of US3908095A publication Critical patent/US3908095A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only 
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/32—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only
    • H04R1/34—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by using a single transducer with sound reflecting, diffracting, directing or guiding means
    • H04R1/342—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by using a single transducer with sound reflecting, diffracting, directing or guiding means for microphones

Definitions

  • ABSTRACT A hand-held tape recording device comprising, within a casing, a reversible electro-acoustic transducer serving as both a microphone and a speaker which performs the functions of converting sound waves into electrical signals and electrical signals into sound waves, tape recording means connected to the transducer, and a concave elliptic sound reflector having first and second foci and juxtaposed to the reversible electro-acoustic transducer for directing sound waves to and from the transducer.
  • the reflector has plural radial splits to facilitate variation in curvature thereof, and the device further includes means carried by the casing for moving the center of the reflector in a direction aligned with the axis of the reflector to vary the curvature of the reflector.
  • This invention relates to a reversible electro-acoustic transducer device or microphone-speaker device serving as both a microphone and a speaker.
  • a reversible electro-acoustic transducer device serving as both a microphone and a speaker permits the functions of converting electric signals into sound waves and sound waves into electric signals to be performed in a single device.
  • Such transducer device offers the advantage of occupying little space when installed in various equipment. In most cases, the device is used as a speaker concurrently serving as a microphone.
  • the equipment of the aformentioned type is preferably of an ultra small size. It is preferable to incorporate in such equipment a reversible electro-acoustic transducer device serving as both a microphone and a speaker in order to attain the end of obtaining an overall compact size in the equipment of the aformentioned type.
  • Reversible electro-acoustic transducer devices which are available for the purpose mentioned above can serve as both a microphone and a speaker, but they are generally much lower in sound conversion efficiency than microphones and loudspeakers which individually perform their respective functions.
  • reversible electro-acoustic transducer devices When reversible electro-acoustic transducer devices are incorporated in equipment of an ultra small type, such transducer devices themselves must be compact in size. A reduction in the size. of reversible electroacoustic transducer devices inevitably has the disadvantage of markedly decreasing their efficiency in performing the functions of converting sound waves into electric signals and electric signals into sound waves.
  • This invention has as its object the provision of a microphone-speaker device wherein a sound reflecting plate provided with a curved sound reflecting surface is juxtaposed to a reversible electro-acoustic transducer arranged in a position which corresponds to a focus of the sound reflecting surface, so that the sound energy conversion efficiency of the transducer. can be increased and aforementioned disadvantage of the prior art can be eliminated.
  • the microphone-speaker device which is constructed as aforementioned has a much enhanced sensitivity in collecting sound when used as a microphone and can provide a sufficiently high sound pressure energy in the service range for satisfactory use as a speaker.
  • the invention in specific aspects contemplates the provision of a concave sound reflector, and transducer means for receiving and emitting sound mounted at a focus of the reflector, for reflective transmission of sound waves by the reflector between the transducer and a locality spaced from' the transducer and reflector.
  • the reflector is an elliptic reflector; in another embodiment, a parabolic sound reflector is used. Means may be provided for adjusting or varying the curvature of the reflector.
  • FIG. 1 is a perspective view of one form of ultra miniature tape recorder
  • FIG. 2 is a plan view showing the manner in which the tape recorder of FIG. 1 is used;
  • FIG. 3 is a sectional view of a microphone-speaker device comprising one embodiment of this invention.
  • FIG. 4 is a sectional view of a modified form of sound reflecting surface suitable for use in a device of the type shown in FIG. 3;
  • FIG. 5 is a sectional view showing one form of means for varying the curvature of the sound reflecting surface in a device embodying the invention.
  • FIG. 1 illustrates an ultra miniature tape recorder I sometimes referred to as a dictating machine, in which a micro-cassette 2 (or a mini-cassette) of the size of a small matchbox (carrying a recording tape) can be detachably inserted.
  • the tape recorder 1 has a built-in small reversible electro-acoustic transducer 3 serving as both a microphone and a speaker and can be set at recording, reproducing and shutoff positions by suitably depressing a pushbutton 4.
  • Transducers of this type are known in the art and accordingly need not b described in detail.
  • the ultra miniature tape recorder of the aforementioned type is generally used in a manner shown in FIG. 2 which is a plan view showing a person H using this equipment.
  • the spacing between the tape recorder l and the mouth M of the person H is substantially equal to the spacing between the tape recorder 1 and the ear E of the person H, and the spacings can be regarded as having a value D which is substantially uniform.
  • This invention is based on the discovery that if a sound reflecting surface is used advantageously by considering the fact that the value D is substantially uniform, the ability of the small reversible electro-acoustic transducer 3 to collect and produce sound can be increased so as to increase its sound energy conversion efficiency markedly.
  • FIG. 3 shows the microphone-speaker device comprising one embodiment of this invention. It shows in an enlarged sectional view the essential portions of the device comprising the small reversible electro-acoustic transducer 3 serving as both a microphone and a speaker built in the tape recorder 1. More specifically, the tape recorder l is housed in a casing la which is formed in one portion or front portion thereof with an opening 1b for permitting sound to enter into the casing and radiate out of the casing therethrough. The opening 1b has mounted therein a perforated support plate 5 which is formed therein with a multitude of perforations 5a.' The small reversible electro acoustic transducer 3 serving as both a microphone and a speaker (i.e. for conversion of sound to electrical signals, and vice versa) is mounted on the perforated support plate 5 in a position in which the center of the sound axis of the transducer 3 coincides with the center of the opening 1b.
  • the tape recorder includes means for driving the tape within the aforementioned micro-cassette and means for recording signals on the tape from the transducer 3 and for detecting signals re- .corded on the tape for conversion to audible sound by the transducer 3$ all such means may be generally conventional, as will be apparent to those skilled in the art, and are therefore not shown, for simplicity of illustration.
  • a sound reflecting plate 6 is attached to a bottom wall 1c of the casing 1a in facing, spaced relation to the transducer 3 and includes a concave sound-reflecting surface 6a which is elliptic in shape, opening toward the transducer 3 with the center of the sound axis serving as a common center axis of the elliptic reflecting surface 6a.
  • An elliptic sound reflector of the type shown at 6 is adapted to reflect sound, emanating from the locality of either of two foci F1 and F2 (spaced along axis 0), to the locality of the other of the two foci.
  • the sound reflecting plate 6 and reversible electro-acoustic transducer 3 are disposed in relative positions such that the position of a first focus Fl of the sound-reflecting surface coincides with the location of a vibration plate 3a of the transducer 3.
  • a second focus F2 of the elliptic sound-reflecting surface 6a will be disposed in a position which is outside the casing la.
  • the second focus F2 is used as a sound transmitting and receiving position for the vibration plate 3a and the spacing between the first focus F1 and the second focus F2 is set at the value D shown in FIG. 2, the sound emanating from the sound transmitting and receiving position corresponding to the second focus F2 will pass through the perforations 5a as indicated by arrows A and will be reflected by the elliptic sound-reflecting surface 6a to converge on the reversible electro-acoustic transducer 3 and cause the vibration plate 3a to vibrate, for conversion of the sound to electrical signals.
  • the sound radiating out of the reversible electro-acoustic transducer 3 will be reflected by the elliptic reflecting surface 6a and pass through the perforations 5a to converge on the second focus F2 as indicated by arrows B.
  • the transducer 3 is oriented to receive sound (for conversion to electrical signals) reflected to focus F1 by surface 6a, and to emit sound toward surface 6a for reflection to focus F2.
  • the elliptic sound-reflecting surface 6a will act as a reflector for effecting convergence of sound waves from that source on reversible electro-acoustic transducer 3 when the transducer is made to function as a microphone.
  • the reversible electroacoustic transducer 3 is made to act as a speaker, the sound radiating out thereof will be reflected by the elliptic reflecting surface 6a and have a considerably high sound pressure when it reaches the second focus F2 or its neighborhood.
  • the reproduced sound can be heard with adequately high sound pressure.
  • the reversible electro-acoustic transducer 3 which is used as aforementioned has a dual directivity in order that sound may be collected and radiated.
  • the surface of the reversible electro-acoustic transducer 3 which faces the sound-reflecting surface 6a is preferably convex, and shaped such that it is rounded as much as possible so as to preclude scattering of reflected sound waves near the reflecting surface.
  • FIG. 3 shows another form of the concave soundreflecting surface which is a parabolic sound-reflecting surface 16a as contrasted to the elliptic soundreflecting surface of FIG. 3.
  • a concave parabolic sound reflector opening toward the transducer 3 mounted within the casing while placing the vibration plate of the reversible electro-acoustic transducer 3 at a first focus F of the reflecting surface 16a, it is possible to cause reflected sound waves (from the mouth of a person or other sound source external to the casing, and directed toward the reflector) to converge on the transducer 3, thereby permitting the same to function as a microphone as satisfactorily as described with reference to FIG. 3.
  • FIG. 5 shows means for attaining the end.
  • the soundreflecting plate 6 provided with the elliptic soundreflecting surface 6a is shown in the figure as being formed with a plurality of splits 6b directed radially of the elliptic surface, so as to facilitate variation or adjustment in curvature of the surface.
  • the means for moving the position of the center of the sound-reflecting plate 6 along the sound axis shown in FIGS comprises an adjusting screw 7 threaded into the bottom wall 1c of the casing 1a so that its forward end may bear against the position of the center of the sound-reflecting plate 6 to move the plate along the sound axis.
  • the adjusting screw 7 is moved outwardly, the curvature of the reflecting plate 6 resting on a supporter 1d is reduced; when it is moved inwardly, the curvature is increased.
  • the curvature of the elliptic soundreflecting plate As aforementioned, it is possible to adjust the elliptic sound emanating and receiving position optimally.
  • the thickness of the beams of the sound radiated out of the transducer and reflected by the reflector can be increased by varying the curvature of the sound-reflecting plate.
  • a hand-held tape recording device comprising a. a casing dimensioned to be held in the human hand, having an opening for passage of sound between the interior and exterior of the casing;
  • a concave elliptic sound reflector having first and second foci and mounted within said casing in facing relation to said opening for directionally reflecting sound between said first focus and a locality external to said casing, said first focus being located within the casing and said second focus being at said external locality;
  • transducer means for receiving and emitting sound, supported by said casing and disposed at said first focus in facing relation to said reflector for receiving sound entering said casing through said opening from said external locality and reflected to said first focus by said reflector and for emitting sound for reflection by said reflector through said opening to said external locality;
  • tape recording means contained within said casing and connected to said transducer means, for recording and reproducing sound
  • said curvaturevarying means comprising means carried by said casing for moving the center of said reflector in a direction aligned with the axis of said reflector.

Landscapes

  • Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Obtaining Desirable Characteristics In Audible-Bandwidth Transducers (AREA)
  • Details Of Audible-Bandwidth Transducers (AREA)
US289746A 1971-09-28 1972-09-15 Microphone-speaker device Expired - Lifetime US3908095A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP46075650A JPS5233963B2 (enrdf_load_stackoverflow) 1971-09-28 1971-09-28

Publications (1)

Publication Number Publication Date
US3908095A true US3908095A (en) 1975-09-23

Family

ID=13582323

Family Applications (1)

Application Number Title Priority Date Filing Date
US289746A Expired - Lifetime US3908095A (en) 1971-09-28 1972-09-15 Microphone-speaker device

Country Status (3)

Country Link
US (1) US3908095A (enrdf_load_stackoverflow)
JP (1) JPS5233963B2 (enrdf_load_stackoverflow)
DE (1) DE2245211B2 (enrdf_load_stackoverflow)

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4002860A (en) * 1974-04-04 1977-01-11 Nippon Telegraph And Telephone Public Corporation Transmitting and receiving apparatus
US4017797A (en) * 1975-02-05 1977-04-12 Columbia Research Laboratories, Inc. Headset for receiving and transmitting signals
US4401859A (en) * 1981-05-29 1983-08-30 Electro-Voice, Incorporated Directional microphone with high frequency selective acoustic lens
US4823908A (en) * 1984-08-28 1989-04-25 Matsushita Electric Industrial Co., Ltd. Directional loudspeaker system
US5532438A (en) * 1993-11-04 1996-07-02 Brown; Kevin Acoustic imaging sound dome
US5616892A (en) * 1996-01-16 1997-04-01 Technology Licensing Company Virtual imaging multiple transducer system
US5764783A (en) * 1996-01-16 1998-06-09 Technology Licensing Company Variable beamwidth transducer
US5793001A (en) * 1996-01-16 1998-08-11 Technology Licensing Company Synchronized multiple transducer system
US5850060A (en) * 1997-04-08 1998-12-15 Gerber; Allen Acoustic lens device
US6031920A (en) * 1997-05-16 2000-02-29 Wiener; David Coaxial dual-parabolic sound lens speaker system
US6055320A (en) * 1998-02-26 2000-04-25 Soundtube Entertainment Directional horn speaker system
US6134332A (en) * 1997-05-16 2000-10-17 Wiener; David Sound lens speaker system
US6527080B2 (en) * 2000-12-02 2003-03-04 Ford Global Technologies, Inc. Passive system for speech enhancement
US6574344B1 (en) 1998-02-26 2003-06-03 Soundtube Entertainment, Inc. Directional horn speaker system
US20080069368A1 (en) * 2006-09-15 2008-03-20 Shumard Eric L Method and apparatus for achieving active noise reduction
US20100031806A1 (en) * 2008-08-05 2010-02-11 Gaynier David A Electroacoustic Transducer System
US20100111346A1 (en) * 2008-10-30 2010-05-06 Foxconn Technology Co., Ltd. Electronic device incorporating sound receiving member and method of manufacturing the same
US20100290659A1 (en) * 2009-05-12 2010-11-18 Sony Corporation Loudspeaker assembly and electronic equipment
US20130083537A1 (en) * 2011-10-04 2013-04-04 Ronald Paul Harwood Acoustically transparent luminaire lens for media assemblies
US20130100233A1 (en) * 2011-10-19 2013-04-25 Creative Electron, Inc. Compact Acoustic Mirror Array System and Method
US20140247958A1 (en) * 2013-03-01 2014-09-04 Chiun Mai Communication Systems, Inc. Sound amplifying device and electronic product using the same
WO2015085178A1 (en) * 2013-12-06 2015-06-11 Scheller Mark W Acoustic electronic device dock
US9161119B2 (en) 2013-04-01 2015-10-13 Colorado Energy Research Technologies, LLC Phi-based enclosure for speaker systems

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5330897Y2 (enrdf_load_stackoverflow) * 1974-05-13 1978-08-02
JPS5114514U (enrdf_load_stackoverflow) * 1974-07-19 1976-02-02
JPS5726459Y2 (enrdf_load_stackoverflow) * 1976-04-21 1982-06-09
JP6441548B1 (ja) * 2018-03-22 2018-12-19 株式会社ジェイアール西日本新幹線テクノス 集音具、及び補聴装置

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1732722A (en) * 1924-01-02 1929-10-22 Westinghouse Electric & Mfg Co Directive-reception microphone
US3078350A (en) * 1958-10-27 1963-02-19 Soundscriber Corp Miniature magnetic tape dictating machine
US3114105A (en) * 1962-02-09 1963-12-10 Neumiller Charles Shoulder mounted radio speaker and microphone
US3305043A (en) * 1965-03-08 1967-02-21 Charles E Pfund Acoustic communication device and toy
US3557899A (en) * 1967-01-10 1971-01-26 Edward G Longinette Riot control devices employing a modulated stimulus frequency

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1732722A (en) * 1924-01-02 1929-10-22 Westinghouse Electric & Mfg Co Directive-reception microphone
US3078350A (en) * 1958-10-27 1963-02-19 Soundscriber Corp Miniature magnetic tape dictating machine
US3114105A (en) * 1962-02-09 1963-12-10 Neumiller Charles Shoulder mounted radio speaker and microphone
US3305043A (en) * 1965-03-08 1967-02-21 Charles E Pfund Acoustic communication device and toy
US3557899A (en) * 1967-01-10 1971-01-26 Edward G Longinette Riot control devices employing a modulated stimulus frequency

Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4002860A (en) * 1974-04-04 1977-01-11 Nippon Telegraph And Telephone Public Corporation Transmitting and receiving apparatus
US4017797A (en) * 1975-02-05 1977-04-12 Columbia Research Laboratories, Inc. Headset for receiving and transmitting signals
US4401859A (en) * 1981-05-29 1983-08-30 Electro-Voice, Incorporated Directional microphone with high frequency selective acoustic lens
US4823908A (en) * 1984-08-28 1989-04-25 Matsushita Electric Industrial Co., Ltd. Directional loudspeaker system
US5532438A (en) * 1993-11-04 1996-07-02 Brown; Kevin Acoustic imaging sound dome
US5764783A (en) * 1996-01-16 1998-06-09 Technology Licensing Company Variable beamwidth transducer
US5793001A (en) * 1996-01-16 1998-08-11 Technology Licensing Company Synchronized multiple transducer system
US5616892A (en) * 1996-01-16 1997-04-01 Technology Licensing Company Virtual imaging multiple transducer system
US5850060A (en) * 1997-04-08 1998-12-15 Gerber; Allen Acoustic lens device
US6031920A (en) * 1997-05-16 2000-02-29 Wiener; David Coaxial dual-parabolic sound lens speaker system
US6134332A (en) * 1997-05-16 2000-10-17 Wiener; David Sound lens speaker system
US6574344B1 (en) 1998-02-26 2003-06-03 Soundtube Entertainment, Inc. Directional horn speaker system
US6055320A (en) * 1998-02-26 2000-04-25 Soundtube Entertainment Directional horn speaker system
US6527080B2 (en) * 2000-12-02 2003-03-04 Ford Global Technologies, Inc. Passive system for speech enhancement
US20080069368A1 (en) * 2006-09-15 2008-03-20 Shumard Eric L Method and apparatus for achieving active noise reduction
US8249265B2 (en) 2006-09-15 2012-08-21 Shumard Eric L Method and apparatus for achieving active noise reduction
US20100031806A1 (en) * 2008-08-05 2010-02-11 Gaynier David A Electroacoustic Transducer System
US8003878B2 (en) * 2008-08-05 2011-08-23 Gaynier David A Electroacoustic transducer system
US20100111346A1 (en) * 2008-10-30 2010-05-06 Foxconn Technology Co., Ltd. Electronic device incorporating sound receiving member and method of manufacturing the same
US20100290659A1 (en) * 2009-05-12 2010-11-18 Sony Corporation Loudspeaker assembly and electronic equipment
US20130083537A1 (en) * 2011-10-04 2013-04-04 Ronald Paul Harwood Acoustically transparent luminaire lens for media assemblies
US20130100233A1 (en) * 2011-10-19 2013-04-25 Creative Electron, Inc. Compact Acoustic Mirror Array System and Method
US9084057B2 (en) * 2011-10-19 2015-07-14 Marcos de Azambuja Turqueti Compact acoustic mirror array system and method
US20140247958A1 (en) * 2013-03-01 2014-09-04 Chiun Mai Communication Systems, Inc. Sound amplifying device and electronic product using the same
US9161119B2 (en) 2013-04-01 2015-10-13 Colorado Energy Research Technologies, LLC Phi-based enclosure for speaker systems
WO2015085178A1 (en) * 2013-12-06 2015-06-11 Scheller Mark W Acoustic electronic device dock
US20170004814A1 (en) * 2013-12-06 2017-01-05 Mark W. SCHELLER Acoustic electronic device dock

Also Published As

Publication number Publication date
JPS4842721A (enrdf_load_stackoverflow) 1973-06-21
JPS5233963B2 (enrdf_load_stackoverflow) 1977-08-31
DE2245211A1 (de) 1973-04-12
DE2245211B2 (de) 1976-09-09

Similar Documents

Publication Publication Date Title
US3908095A (en) Microphone-speaker device
US4058688A (en) Headphone
US3816672A (en) Sound reproduction system
US4088849A (en) Headphone unit incorporating microphones for binaural recording
US5220608A (en) Method and means for stereophonic sound reproduction
AU2016210715B2 (en) Acoustic Diffusion Generator
US4278852A (en) Earphone construction
US4553628A (en) Speaker system
US4369857A (en) Loudspeaker and horn combination
US3059720A (en) High frequency loudspeakers
US5109424A (en) Stereo headphones with plug, receptacle and securing plates
JPH07505269A (ja) 二要素ヘッドホン
GB2140653A (en) A piezoelectric sound producer
US3891810A (en) Headphone
GB2150398A (en) Directional microphone assembly
GB2366683A (en) Loudspeaker system
JP2006502657A (ja) 指向特性を改善した音響再生装置
US4219099A (en) Acoustic reproduction transducer enclosure
US3194339A (en) Loudspeaker system
US2580439A (en) Directional acoustic system
US3814857A (en) Two-way loudspeaker system with two tandem-connected high-range speakers
US4657107A (en) Loudspeaker cabinet
CN217063997U (zh) 号角及扬声器
EP1062837A1 (en) Radial pickup microphone enclosure
CN211481439U (zh) 无线耳机、耳机盒及耳机组件