EP0077228A2 - Electroacoustic transducer - Google Patents
Electroacoustic transducer Download PDFInfo
- Publication number
- EP0077228A2 EP0077228A2 EP82401685A EP82401685A EP0077228A2 EP 0077228 A2 EP0077228 A2 EP 0077228A2 EP 82401685 A EP82401685 A EP 82401685A EP 82401685 A EP82401685 A EP 82401685A EP 0077228 A2 EP0077228 A2 EP 0077228A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- casing
- diaphragm
- electroacoustic transducer
- coil
- inner surfaces
- 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
Links
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Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R9/00—Transducers of moving-coil, moving-strip, or moving-wire type
- H04R9/02—Details
- H04R9/04—Construction, mounting, or centering of coil
- H04R9/046—Construction
- H04R9/047—Construction in which the windings of the moving coil lay in the same plane
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R9/00—Transducers of moving-coil, moving-strip, or moving-wire type
- H04R9/06—Loudspeakers
- H04R9/063—Loudspeakers using a plurality of acoustic drivers
Definitions
- This invention relates to an electroacoustic transducer for use in a full range speaker for audio, a twitter speaker and other normal speakers, a handset for telephone, a headphone, microphone units and the like.
- a speaker comprising a voice coil attached to a top end portion opposite to a front opening portion of a corn-shaped diaphragm and an electromagnetic driving section disposed so as to make a magnetic circuit at fine gaps in said voice coil wherein when a voice signal is sent to said voice coil, the voice coil is driven vertically in concert therewith and said.corn-shaped diaphragm emits a sound output.
- the thus constructed speaker is defective in that since the diaphragm per se is corn-shaped the unit inevitably gets large-sized and thick as a whole, further it is inferior in vibration-proof, and still further the diaphragm has a tendency of vibrating sectionally in a high pitched tone area, whereby voice can not be reproduced with high fidelity.
- the inventor of this invention has proposed the electroacoustic transducer illustrated in Fig. 1 as the electroacoustic transducer capable of eliminating the aforegoing defects.
- This prior art electroacoustic transducer comprises printing coils 23 on both end portions and floatingly supports, a convexly curved sheet diaphragm 22 by means of permanent magnets 24 and 25 disposed adjacent to each coil 23 in a casing 21, wherein when an electric current is applied to each coil 23 an electromagnetic force exerted on each coil 23 displaces both end portions of said diaphragm along its surface, thereby causing its central curved portion to displace to dotted places in the perpendicular direction relative to the diaphragm surface for producing a sound, and this sound is emitted to the outside.
- This electroacoustic transducer designed as above, is capable of doubling the amount of displacement of the central curved portion of the diaphragm 22 as compared to that of each end portion thereof. Therefore, this electroacoustic transducer is advantageous in that despite use of a plane drive, it has a wide directivity, it can be made thin as a whole and further it has a superiority in producing a low sound.
- said electroacoustic transducer is disadvantageous in that since electromagnetic driving sections must be provided at both end portions of the diaphragm 22, there is required a wide printing area for the coil 23, the number of permanent magnets needed is four and thus a number of parts are required, whereby it is difficult to make it small-sized as a whole and the use is limited thereby.
- an electroacoustic transducer including a casing having an opening portion; a sheet diaphragm disposed in said casing and extending from said opening portion side to its opposite side, in which one end thereof is formed as a fixed end and fixed in the casing, the other end thereof is formed as a free end supported floatingly in the casing, a curved portion is formed in the middle of the fixed and free ends and a coil is provided in the vicinity of the free end; and permanent magnets arranged opposite relative to the coil of this diaphragm in the casing.
- said object can be achieved by providing an electroacoustic transducer which comprises arranging a pair of sheet diaphragms with curved portions symmetrically in a casing, overlapping the portions adjacent to their rear edge portions into one layer, forming one of the front and rear edges into a fixed end and the other into a free end, providing a coil in the vicinity of said free end, and disposing permanent magnets at the positions opposite to coils attached to the inner surfaces of upper and lower walls of the casing.
- said object can be achieved by providing an electroacoustic transducer which comprises connecting both side edges of a curved plate of a diaphragm to inner surfaces of both side walls of a casing by means of a flexible material-made free edge member.
- Figs. 2 to 5 illustrate a first embodiment of the electroacoustic transducer according to this invention respectively.
- reference numeral 1 denotes a casing including upper and lower walls 7 and 8, side walls 9 and 10; and an opening portion 6-at the front edge, wherein a pair of upper and lower diaphragms 2 are disposed symmetrically.
- each diaphragm 2 comprises a printed plate having thereon formed a rectangular and circular coil 3 by applying a copper foil on about the half (the right half in Fig. 5) of the surface of a properly flexible synthetic resin sheet 11 and subjecting the same to chemical etching.
- This coil 3 may be formed on the surface of sheet 11 in another way than the above mentioned.
- the diaphragm 2 As illustrated in Fig. 2, its front edge 12 opposite to the coil 3 is fixed in the inner surface of each of the upper and lower walls 7 and 8 of the casing 1 in the vicinity of the opening portion 6.
- the portions which contain coil 3 and which are adjacent to the rear edges overlap each other so that the coils 3 of both diaphragms 2 are connected to have a plus terminal and a minus terminal in common.
- the thus overlapped rear edge 13 is supported movably in the horizontal direction (the right and left directions in Fig. 3) by a holding member 14 erected on the inner surface of the lower wall 8.
- the diaphragm 2 has curved portions 15 formed in the middle of front edges 12 and the coil 3, and consequently, as can be seen from Fig. 3, takes the shape of the longitudinal sectional surface of a horn speaker viewed from the side.
- the inner surfaces of the upper and lower walls 7 and 8 of the casing 1 are provided with permanent magnets 4 and 5 at places opposite to the coil 3 respectively, wherein poles S and N of the permanent magnet 4 are devised to confront poles N and S of the permanent magnet 5 and both minus terminals of the coil 3 are common and connected to a signal source (not shown) such as an amplifier or the like.
- the permanent magnets 4 and 5 are surrounded with a magnetic material 16 such as iron or the like.
- this electroacoustic transducer having a construction as described above, can double the amount of movement of the curved portion 15 in comparison with that of the coil 3, whereby a very satisfactory low-ranged sound reproduction can be obtained. Further, since there is no necessity of increasing the amount of movement of coil 3, the mounting area therefor may be decreased. Still further, since it is sufficient to dispose two permanent magnets 4 and 5 only at the places confronting this coil 3, the number of parts may be decreased with respect to the aforesaid prior art transducer which requires four permanent magnets. Accordingly, the electroacoustic transducer according to this invention can be markedly small-sized as a whole.
- electroacoustic transducer in which, unlike the said embodiment, not a pair but only one diaphragm 2 is provided and only one permanent magnet is also provided. That is, this electroacoustic transducer can be made more thick and small-sized than that disclosed in_ said embodiment.
- the electroacoustic transducer according to said embodiment is advantageous in that owing to the provision of a pair of diaphragms 2 there can be obtained a cylindrical plane wave type sound that . can release a listener from being tired with hearing as compared with a spherical wave type one.
- both side edges 17 of the diaphragm 2- are connected with both side walls 9 and 10 by means of the free edge 18, the vibrating wave generated rearwards (to the right in Fig. 3) by the vibration of the diaphragm 2 is allowed to leak forward through the gaps between both side edges 17 of the diaphragm 2 and both side walls 9 and 10 of the casing 1 so that the normal vibrating wave may be released from the interference to be caused thereby, whereby sound reproduction can be effected correctly and readily up to the low range such as about 150 Hz and even when used as a car radio speaker the hindrance from noises outside of the car can be reduced.
- Fig. 7 illustrates a second embodiment of the electroacoustic transducer according to this invention.
- This embodiment is different from the first embodiment in that since a front edge 12' of a diaphragm 2' is formed in a free end and a rear edge 13' thereof is formed in a fixed end, a coil 3 is provided in the vicinity of the front edge 12', permanent magnets 4' and 5' are disposed.on the inner surfaces of upper and lower walls of a casing 1, and the rear edge 13' is fixed by means of a holding member 14'.
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
- Diaphragms For Electromechanical Transducers (AREA)
Abstract
Description
- This invention relates to an electroacoustic transducer for use in a full range speaker for audio, a twitter speaker and other normal speakers, a handset for telephone, a headphone, microphone units and the like.
- As one typical example of the electroacoustic transducers there is usually known a speaker comprising a voice coil attached to a top end portion opposite to a front opening portion of a corn-shaped diaphragm and an electromagnetic driving section disposed so as to make a magnetic circuit at fine gaps in said voice coil wherein when a voice signal is sent to said voice coil, the voice coil is driven vertically in concert therewith and said.corn-shaped diaphragm emits a sound output.
- However, the thus constructed speaker is defective in that since the diaphragm per se is corn-shaped the unit inevitably gets large-sized and thick as a whole, further it is inferior in vibration-proof, and still further the diaphragm has a tendency of vibrating sectionally in a high pitched tone area, whereby voice can not be reproduced with high fidelity.
- The inventor of this invention has proposed the electroacoustic transducer illustrated in Fig. 1 as the electroacoustic transducer capable of eliminating the aforegoing defects. This prior art electroacoustic transducer comprises
printing coils 23 on both end portions and floatingly supports, a convexlycurved sheet diaphragm 22 by means ofpermanent magnets coil 23 in acasing 21, wherein when an electric current is applied to eachcoil 23 an electromagnetic force exerted on eachcoil 23 displaces both end portions of said diaphragm along its surface, thereby causing its central curved portion to displace to dotted places in the perpendicular direction relative to the diaphragm surface for producing a sound, and this sound is emitted to the outside. This electroacoustic transducer, designed as above, is capable of doubling the amount of displacement of the central curved portion of thediaphragm 22 as compared to that of each end portion thereof. Therefore, this electroacoustic transducer is advantageous in that despite use of a plane drive, it has a wide directivity, it can be made thin as a whole and further it has a superiority in producing a low sound. - On the other hand, said electroacoustic transducer is disadvantageous in that since electromagnetic driving sections must be provided at both end portions of the
diaphragm 22, there is required a wide printing area for thecoil 23, the number of permanent magnets needed is four and thus a number of parts are required, whereby it is difficult to make it small-sized as a whole and the use is limited thereby. - It is an object of this invention to provide an electroacoustic transducer capable of eliminating the inherent disadvantages in the above mentioned prior art electroacoustic transducer and exhibiting its advantages as they are, in other words an electroacoustic transducer that has a small number of parts, is easily small-sized as a whole and is applicable for a wide range of applications.
- According to this invention, said object can be achieved by providing an electroacoustic transducer including a casing having an opening portion; a sheet diaphragm disposed in said casing and extending from said opening portion side to its opposite side, in which one end thereof is formed as a fixed end and fixed in the casing, the other end thereof is formed as a free end supported floatingly in the casing, a curved portion is formed in the middle of the fixed and free ends and a coil is provided in the vicinity of the free end; and permanent magnets arranged opposite relative to the coil of this diaphragm in the casing.
- It is another object of this invention to provide an electroacoustic transducer that can produce a cylindrical plane wave type sound capable of releasing a listener from being tired with hearing by means of a sheet diaphragm, can attain an acoustic efficiency similar to that of the usual horn speaker in spite of being made thin as a whole due to the capability of producing such a cylindrical plane wave, and is especially suitable as a speaker for car radio and the like.
- According to this invention, said object can be achieved by providing an electroacoustic transducer which comprises arranging a pair of sheet diaphragms with curved portions symmetrically in a casing, overlapping the portions adjacent to their rear edge portions into one layer, forming one of the front and rear edges into a fixed end and the other into a free end, providing a coil in the vicinity of said free end, and disposing permanent magnets at the positions opposite to coils attached to the inner surfaces of upper and lower walls of the casing.
- It is a further object of this invention to provide an electroacoustic transducer designed so that a sound produced on the side opposite to an opening portion of a casing by a diaphragm is allowed to leak from between both side edges of the diaphragm and the inner surfaces of both side walls of the casing so as to prevent a sound emitted toward the opening portion side from undergoing interference therefrom, whereby it can reproduce an espacially low-ranged (about 150 Hz) sound readily and further it, especially when used as a car radio speaker or the like, has no fear of being hindered by noises outside the car.
- According to this invention, said object can be achieved by providing an electroacoustic transducer which comprises connecting both side edges of a curved plate of a diaphragm to inner surfaces of both side walls of a casing by means of a flexible material-made free edge member.
- ' BRIEF DESCRIPTION OF THE DRAWING.
- Fig. 1 is a longitudinal sectional front view of the prior art electroacoustic transducer which the inventor of this invention has proposed previously.
- Fig. 2 is a front view of a first embodiment of the electroacoustic transducer according to this invention.
- Fig. 3 is a longitudinal sectional side view taken on line 3-3 according to the direction of the arrow of Fig. 2.
- Fig. 4 is a slant view illustrating the partially cutaway inside of the electroacoustic transducer of Fig. 2 wherein the cutaway portion is indicated with a chain line.
- Fig. 5 is a plan view of the diaphragm of the electroacoustic transducer illustrated in Fig. 2.
- Fig. 6 is a partially enlarged sectional view taken on line 6-6 according to the direction of the arrow of Fig. 2.
- Fig. 7 is a schematic side view of the main portion of a second embodiment of the electroacoustic transducer according to this invention.
- Figs. 2 to 5 illustrate a first embodiment of the electroacoustic transducer according to this invention respectively.
- In these figures,
reference numeral 1 denotes a casing including upper andlower walls side walls 9 and 10; and an opening portion 6-at the front edge, wherein a pair of upper andlower diaphragms 2 are disposed symmetrically. - As is best evident from Fig. 5, each
diaphragm 2 comprises a printed plate having thereon formed a rectangular andcircular coil 3 by applying a copper foil on about the half (the right half in Fig. 5) of the surface of a properly flexible synthetic resin sheet 11 and subjecting the same to chemical etching. Thiscoil 3 may be formed on the surface of sheet 11 in another way than the above mentioned. - In the case of the
diaphragm 2 as illustrated in Fig. 2, itsfront edge 12 opposite to thecoil 3 is fixed in the inner surface of each of the upper andlower walls casing 1 in the vicinity of the opening portion 6. On the other hand, the portions which containcoil 3 and which are adjacent to the rear edges overlap each other so that thecoils 3 of bothdiaphragms 2 are connected to have a plus terminal and a minus terminal in common. The thus overlappedrear edge 13 is supported movably in the horizontal direction (the right and left directions in Fig. 3) by aholding member 14 erected on the inner surface of thelower wall 8. Thediaphragm 2 has curvedportions 15 formed in the middle offront edges 12 and thecoil 3, and consequently, as can be seen from Fig. 3, takes the shape of the longitudinal sectional surface of a horn speaker viewed from the side. - The inner surfaces of the upper and
lower walls casing 1 are provided withpermanent magnets coil 3 respectively, wherein poles S and N of thepermanent magnet 4 are devised to confront poles N and S of thepermanent magnet 5 and both minus terminals of thecoil 3 are common and connected to a signal source (not shown) such as an amplifier or the like. Thepermanent magnets magnetic material 16 such as iron or the like. - The gaps formed between both
side edges 17 ofcurved portions 15 of thediaphragm 2 and bothside walls 9 and 10 ofcasing 1 are closed by means of flexiblefree edges 18 as shown in detail in Fig. 6, wherein one side edge of thefree edge 18 is connected with theside edge 17 of thediaphragm 2 and the other side edge thereof is connected withside walls 9 and 10. - The operation of this transducer will now be described hereinafter.
- When an electric signal is impressed between the plus terminal and the minus terminal of
coil 3, right and left directional forces (in Fig. 3) are generated in thecoil 3 crossing a line of magnetic force present betweenpermanent magnets rear edge 13 of thediaphragm 2 is moved as indicated by the arrow. This movement subjects thecurved portion 15 to a vertically directional flexible deformation as indicated by chain lines in'Fig. 3 for vibrating the air present between bothdiaphragms 2 and emitting to the outside through the opening portion 6, whereby a sound corresponding to the electric signal can be produced. - In this case, this electroacoustic transducer, having a construction as described above, can double the amount of movement of the
curved portion 15 in comparison with that of thecoil 3, whereby a very satisfactory low-ranged sound reproduction can be obtained. Further, since there is no necessity of increasing the amount of movement ofcoil 3, the mounting area therefor may be decreased. Still further, since it is sufficient to dispose twopermanent magnets coil 3, the number of parts may be decreased with respect to the aforesaid prior art transducer which requires four permanent magnets. Accordingly, the electroacoustic transducer according to this invention can be markedly small-sized as a whole. The same is true of an electroacoustic transducer in which, unlike the said embodiment, not a pair but only onediaphragm 2 is provided and only one permanent magnet is also provided. That is, this electroacoustic transducer can be made more thick and small-sized than that disclosed in_ said embodiment. - By the way, the electroacoustic transducer according to said embodiment is advantageous in that owing to the provision of a pair of
diaphragms 2 there can be obtained a cylindrical plane wave type sound that . can release a listener from being tired with hearing as compared with a spherical wave type one. - According to the said embodiment, furthermore, since both
side edges 17 of the diaphragm 2- are connected with bothside walls 9 and 10 by means of thefree edge 18, the vibrating wave generated rearwards (to the right in Fig. 3) by the vibration of thediaphragm 2 is allowed to leak forward through the gaps between bothside edges 17 of thediaphragm 2 and bothside walls 9 and 10 of thecasing 1 so that the normal vibrating wave may be released from the interference to be caused thereby, whereby sound reproduction can be effected correctly and readily up to the low range such as about 150 Hz and even when used as a car radio speaker the hindrance from noises outside of the car can be reduced. - Fig. 7 illustrates a second embodiment of the electroacoustic transducer according to this invention. This embodiment is different from the first embodiment in that since a front edge 12' of a diaphragm 2' is formed in a free end and a rear edge 13' thereof is formed in a fixed end, a
coil 3 is provided in the vicinity of the front edge 12', permanent magnets 4' and 5' are disposed.on the inner surfaces of upper and lower walls of acasing 1, and the rear edge 13' is fixed by means of a holding member 14'. - In view of the fact that the electroacoustic transducing operation disclosed in the second embodiment is just the same as that disclosed in the first embodiment and there is no difference in the resultant advantages therebetween, detailed explanation on the former will be omitted as being needless.
Claims (9)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP137978/81U | 1981-09-17 | ||
JP13797881U JPS5843091U (en) | 1981-09-17 | 1981-09-17 | Diaphragm for electroacoustic transducer |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0077228A2 true EP0077228A2 (en) | 1983-04-20 |
EP0077228A3 EP0077228A3 (en) | 1983-06-01 |
EP0077228B1 EP0077228B1 (en) | 1986-02-26 |
Family
ID=15211184
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP82401685A Expired EP0077228B1 (en) | 1981-09-17 | 1982-09-16 | Electroacoustic transducer |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0077228B1 (en) |
JP (1) | JPS5843091U (en) |
DE (1) | DE3269415D1 (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0150976A2 (en) * | 1984-01-27 | 1985-08-07 | Lawrence E. Arntson | Soundstage boundary expansion system |
GB2193413A (en) * | 1985-12-10 | 1988-02-03 | Reefgrade Limited | Electromechanical transducer |
GB2194707A (en) * | 1985-12-10 | 1988-03-09 | Reefgrade Limited | Electromechanical transducer |
US5103482A (en) * | 1988-07-28 | 1992-04-07 | Fabri Conti Lucas | Apparatus and method for reproducing high fidelity sound |
EP0529143A2 (en) * | 1991-08-30 | 1993-03-03 | Filip Keller | Diaphragm for loudspeaker or microphone |
FR2851115A1 (en) * | 2003-02-10 | 2004-08-13 | Patrick Hoffmann | ACOUSTIC TRANSDUCER GENERATING SOUND RADIATION BY COMPRESSION AND EXPANSION OF AN AIR MASS LOCATED BETWEEN A MOBILE MEMBRANE AND A FIXED SURFACE OR BETWEEN TWO MOBILE MEMBRANES |
EP2866467A1 (en) * | 2013-10-22 | 2015-04-29 | Yamaha Corporation | Electroacoustic transducer |
CN104581558A (en) * | 2013-10-22 | 2015-04-29 | 雅马哈株式会社 | Electroacoustic transducer |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS62154276A (en) * | 1985-12-26 | 1987-07-09 | Konishiroku Photo Ind Co Ltd | Recording and reproducing device for magnetic sheet |
WO2016110991A1 (en) * | 2015-01-09 | 2016-07-14 | ヤマハ株式会社 | Electroacoustic transducer |
WO2016110992A1 (en) * | 2015-01-09 | 2016-07-14 | ヤマハ株式会社 | Electroacoustic transducer |
Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1251381B (en) * | 1964-06-16 | |||
GB246099A (en) * | 1925-01-15 | 1926-05-13 | Lee De Forest | Improvements in sound reproducing devices |
GB256252A (en) * | 1925-08-01 | 1927-01-27 | Louis Lumiere | Improvements in acoustic diaphragms |
FR621452A (en) * | 1925-08-11 | 1927-05-12 | Siemens Ag | Acoustic instrument |
US1638245A (en) * | 1925-07-17 | 1927-08-09 | Davis Charles Crawford | Loud speaker |
DE464015C (en) * | 1926-08-29 | 1928-08-14 | Siemens & Halske Akt Ges | Membrane for sound apparatus |
US1866090A (en) * | 1926-05-22 | 1932-07-05 | Forest Lee De | Sound reproducing device |
JPS51135638A (en) * | 1975-05-20 | 1976-11-24 | Trio Kenwood Corp | Electric acoustic changer |
FR2410409A1 (en) * | 1977-11-26 | 1979-06-22 | Sony Corp | DYNAMIC SPEAKER |
WO1980001128A1 (en) * | 1978-11-16 | 1980-05-29 | Audax | Electro acoustic transducer |
JPS5754499A (en) * | 1980-09-19 | 1982-03-31 | Sawafuji Dainameka Kk | Electromagnetic converter |
-
1981
- 1981-09-17 JP JP13797881U patent/JPS5843091U/en active Pending
-
1982
- 1982-09-16 DE DE8282401685T patent/DE3269415D1/en not_active Expired
- 1982-09-16 EP EP82401685A patent/EP0077228B1/en not_active Expired
Patent Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB246099A (en) * | 1925-01-15 | 1926-05-13 | Lee De Forest | Improvements in sound reproducing devices |
US1638245A (en) * | 1925-07-17 | 1927-08-09 | Davis Charles Crawford | Loud speaker |
GB256252A (en) * | 1925-08-01 | 1927-01-27 | Louis Lumiere | Improvements in acoustic diaphragms |
FR621452A (en) * | 1925-08-11 | 1927-05-12 | Siemens Ag | Acoustic instrument |
US1866090A (en) * | 1926-05-22 | 1932-07-05 | Forest Lee De | Sound reproducing device |
DE464015C (en) * | 1926-08-29 | 1928-08-14 | Siemens & Halske Akt Ges | Membrane for sound apparatus |
DE1251381B (en) * | 1964-06-16 | |||
JPS51135638A (en) * | 1975-05-20 | 1976-11-24 | Trio Kenwood Corp | Electric acoustic changer |
FR2410409A1 (en) * | 1977-11-26 | 1979-06-22 | Sony Corp | DYNAMIC SPEAKER |
WO1980001128A1 (en) * | 1978-11-16 | 1980-05-29 | Audax | Electro acoustic transducer |
JPS5754499A (en) * | 1980-09-19 | 1982-03-31 | Sawafuji Dainameka Kk | Electromagnetic converter |
Non-Patent Citations (2)
Title |
---|
FUNKSCHAU, vol. 52, no. 3, February 1980, pages 78-80, Münich (DE); * |
PATENTS ABSTRACTS OF JAPAN, vol. 1, no. 38, 19th April 1977, page 2274 E76; & JP - A - 51 135 638 (TORIO K.K.) (24-11-1976) * |
Cited By (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0150976A2 (en) * | 1984-01-27 | 1985-08-07 | Lawrence E. Arntson | Soundstage boundary expansion system |
EP0150976A3 (en) * | 1984-01-27 | 1987-08-26 | Lawrence E. Arntson | Soundstage boundary expansion system |
GB2193413A (en) * | 1985-12-10 | 1988-02-03 | Reefgrade Limited | Electromechanical transducer |
GB2194707A (en) * | 1985-12-10 | 1988-03-09 | Reefgrade Limited | Electromechanical transducer |
US5103482A (en) * | 1988-07-28 | 1992-04-07 | Fabri Conti Lucas | Apparatus and method for reproducing high fidelity sound |
EP0529143A2 (en) * | 1991-08-30 | 1993-03-03 | Filip Keller | Diaphragm for loudspeaker or microphone |
EP0529143A3 (en) * | 1991-08-30 | 1993-07-07 | Filip Keller | Diaphragm for loudspeaker or microphone |
FR2851115A1 (en) * | 2003-02-10 | 2004-08-13 | Patrick Hoffmann | ACOUSTIC TRANSDUCER GENERATING SOUND RADIATION BY COMPRESSION AND EXPANSION OF AN AIR MASS LOCATED BETWEEN A MOBILE MEMBRANE AND A FIXED SURFACE OR BETWEEN TWO MOBILE MEMBRANES |
WO2004071128A2 (en) * | 2003-02-10 | 2004-08-19 | Rötelzeichnung Holding A.G. | Electrodynamic acoustic transducer |
WO2004071128A3 (en) * | 2003-02-10 | 2004-09-30 | Roetelzeichnung Holding A G | Electrodynamic acoustic transducer |
US7426281B2 (en) | 2003-02-10 | 2008-09-16 | Rötelzeichnung Holding A.G. | Electrodynamic acoustic transducer |
EP2866467A1 (en) * | 2013-10-22 | 2015-04-29 | Yamaha Corporation | Electroacoustic transducer |
CN104581558A (en) * | 2013-10-22 | 2015-04-29 | 雅马哈株式会社 | Electroacoustic transducer |
EP2869595A1 (en) * | 2013-10-22 | 2015-05-06 | Yamaha Corporation | Electroacoustic transducer |
US9106988B2 (en) | 2013-10-22 | 2015-08-11 | Yamaha Corporation | Electroacoustic transducer |
EP3038379A1 (en) * | 2013-10-22 | 2016-06-29 | Yamaha Corporation | Electroacoustic transducer |
US9398376B2 (en) | 2013-10-22 | 2016-07-19 | Yamaha Corporation | Electroacoustic transducer |
US9560453B2 (en) | 2013-10-22 | 2017-01-31 | Yamaha Corporation | Electroacoustic transducer |
Also Published As
Publication number | Publication date |
---|---|
JPS5843091U (en) | 1983-03-23 |
EP0077228B1 (en) | 1986-02-26 |
DE3269415D1 (en) | 1986-04-03 |
EP0077228A3 (en) | 1983-06-01 |
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