Abstract
The invention relates to a speaker-element for a speaker, comprising two substantially mutually opposing spaced apart membrane planes, wherein each membrane plane comprises at least one electromagnetic wire arranged for creating a magnetic field upon an electric current passing through said electromagnetic wire, wherein at least one permanent magnet is arranged between the two membrane planes, wherein the electromagnet wires of the two membrane planes are connectable to an electric power source in such a manner, that the electric current passes there trough in substantially mutually opposing directions and thereby creating substantially mutually opposing magnetic fields, such that upon passing an electric current through the electromagnetic wire of each membrane plane said membrane planes are both either attracted towards or repulsed from the permanent magnet and thereby moved towards or away from each other, respectively, thereby producing a sound wave.
Claims
1. A speaker-element for a speaker, comprising: two substantially mutually opposing spaced apart membrane planes, wherein each membrane plane comprises at least one electromagnetic wire arranged for creating a magnetic field upon an electric current passing through said electromagnetic wire, wherein at least one permanent magnet is arranged between the two membrane planes, wherein the electromagnet wires of the two membrane planes are connectable to an electric power source such that the electric current passes therethrough in substantially mutually opposing directions and thereby creates substantially mutually opposing magnetic fields such that upon passing an electric current through the electromagnetic wire of each membrane plane said membrane planes are both either attracted towards or repulsed from the permanent magnet and thereby moved towards or away from each other, respectively, thereby producing a sound wave.
2. The speaker-element according to claim 1, wherein each said electromagnetic wire is arranged substantially in a middle line of each said membrane plane, such that substantially equal membrane parts are arranged on both sides of said electromagnetic wire.
3. The speaker -element according to claim 1, wherein said permanent magnet extends substantially parallel to the at least two electromagnetic wires with a longitudinal length thereof in such a manner that the at least two electromagnetic wires are arranged in front of two opposing longitudinal surfaces of the permanent magnet.
4. The speaker-element according to claim 1, wherein said two substantially mutually opposing membrane planes are arranged at an oblique angle with respect to each other, said angle being chosen between 0° and 75°.
5. The speaker-element according to claim 1, wherein said two membrane planes together define a circumferential edge zone, which circumferential edge zone is closed over a first part thereof and open over a second part thereof.
6. The speaker-element according to claim 1, wherein each membrane plane comprises four of said electromagnetic wires, which four wires are arranged in parallel to each other with no or a small mutual distance.
7. The speaker-element according to claim 1, wherein each said electromagnetic wire is a copper wire.
8. The speaker-element according to claim 1, wherein each electromagnetic wire is attached to the membrane plane using a polyimide tape.
9. The speaker-element according to claim 1, comprising a frame for holding a circumferential edge of each membrane plane, wherein the circumferential edge of each membrane plane is arranged between two frame parts of said frame and held tight thereby.
10. The speaker-element according to claim 9, comprising two angular profiles made of a flexible and/or compressible material, said angular profiles being arranged between said frame parts in the area of said circumferential edge of the membrane plane for tensioning said membrane plane.
11. A speaker, comprising a plurality of speaker-elements according to claim 1.
12. The speaker according to claim 11, said speaker defining a central longitudinal line, wherein said plurality of speaker-elements are arranged in a radial direction with respect to said central longitudinal line and spaced apart by an angular distance.
13. The speaker according to claim 12, wherein five of said speaker-elements are provided which are spaced apart over an angular distance of about 60°.
14. The speaker according to claim 13, wherein at least one further series of five of said speaker-elements is provided which are spaced apart over an angular distance of about 60°, and wherein the at least one further series is arranged on top of said five speaker-elements in such a manner that the speaker-elements are aligned.
15. The speaker according to claim 11, wherein the plurality of speaker elements are spaced along and aligned with each other along an imaginary line with one membrane plane of one speaker-element substantially facing a membrane plane of an adjacent speaker-element, thereby forming a column of speaker elements.
16. The speaker according to claim 15, wherein the imaginary line along which the speaker-elements are arranged comprises a first section which is straight, and a second section which is curved.
Description
[0054] The invention will be further elucidated with reference to the attached schematic figures, in which:
[0055] FIG. 1A is a schematic perspective transverse cross section through a speaker according to a first embodiment of the invention;
[0056] FIG. 1B is a detail of FIG. 1A;
[0057] FIG. 2 is a schematic perspective view of a speaker according to a second embodiment of the invention; and
[0058] FIGS. 3A and 3B are schematic perspective views of other embodiments of the speaker according to the invention.
[0059] In the figures, like elements are referred to by like reference numerals.
[0060] FIG. 1A shows a speaker 1 according to a first embodiment of the invention having five speaker-elements 2 according to a first embodiment of the invention. Two of the speaker-elements 2 are shown transparently. FIG. 1B shows one of the speaker-elements 2 in more detail.
[0061] As is clear from FIGS. 1A and 1B each speaker-element 2 comprises two substantially mutually opposing spaced apart membrane planes 3. In this embodiment each membrane plane 3 is formed by a separate membrane 3, for example made of Mylar. Each membrane plane 3 comprises in this embodiment four electromagnetic copper wires 4 arranged for creating a magnetic field upon an electric current passing through said electromagnetic wires 4. The wires 4 extend parallel to each other with no or a small distance there between and are attached to the membrane plane using a kapton tape, such that in the figures the wires 4 appear to be one, rather thick wire. In this embodiment the wires 4 are arranged in the vertical middle line of the membrane plane 3. Between the membrane planes 3 a permanent magnet 5 is arranged, which is held by two holding plates 6, which are arranged on opposite front and back sides of the magnet 5 for holding the magnet 5 there between. Screws 10 are provided for connecting the plates 6 to each other. The magnet 5 extends substantially parallel to the wires 4 and the wires 4 are arranged such that they are in front of the longitudinal side surfaces of the magnet 5. When a current passes through the wires 4 a magnetic field is created thereby. As is shown in FIG. 1B, the current passes through the wires 4 in opposite directions 7, 8 in view of the two membrane planes 3 of the speaker-element 2. As a result of the opposite directions 7, 8 the magnetic fields created by the wires 4 of the two membrane planes 3 are opposite to each other, such that both membrane planes 3 are either attracted towards or repulsed from the magnet 5 and are thus moved in opposite directions. It will be clear for the skilled person that the upward direction 7 and downward direction 8 are shown by way of example only and may be reversed, as long as they are opposite to each other. More in particular, the current passing through wires 4 varies continuously between the upward and downward directions, such that the membrane planes 3 are continuously attracted towards and repulsed from the magnet 5, thereby creating sound waves. External sound waves created on the outside of membrane planes 3 can travel outwards, as indicated by arrow 9. Insulator elements 11 are provided between neighboring speaker-elements 2 for preventing sound waves that are created internally of the speaker-elements 2 to leave the speaker between neighboring speaker-elements 2. The insulator elements may for example be made of rubber or any other suitable material. The applicant has found that otherwise the internal sound waves interfere with the external sound waves. The applicant has found that the internal sound waves may leave the speaker 1 at a back of the speaker 1, but the effect thereof may be negligible. As is further clear from FIGS. 1A and 1B, in this embodiment the membrane planes 3 are diverging under an angle a of 67.5°. As a result of this angle the sound waves travel in a desired direction 9.
[0062] As is shown in FIGS. 1A and 1B, the membrane planes 3 are held by a frame. Said frame comprises inner and outer circumferential frame parts 12-14, wherein the inner circumferential frame part 12, 13 comprises a central frame part 12 arranged at the converging, small end of the speaker element 2 to which both membrane planes 3 are attached, and which inner frame part splits into two frame parts 13 in the diverging direction of the speaker-element 2. Two outer circumferential frame parts 14 are attached to the inner circumferential frame part 12, 13, wherein the membrane planes 3 are arranged between the inner and outer circumferential frame parts 12-14 and therefore held tight thereby. Rubber angular profiles 15 extend between the membrane planes 3 and the outer circumferential frame parts 14, such that the membrane planes 3 are tensioned. The outer and inner frame parts 12 — 14 are attached to each other using screws 16. The inner circumferential frame parts 12, 13 close a circumferential edge zone of the speaker-element 2 at the upper, lower, and outer sides thereof, and only the inner side of the circumferential edge zone of the speaker-element is left open, such that sound waves can travel to the inner part of the speaker and then leave the speaker via elements 11 as described above.
[0063] FIG. 1A further shows that the speaker-elements 2 are arranged on a substantially circular plate 17. The speaker-elements 2 extend radially with respect to the central longitudinal line of the speaker 2 and are spaced apart radially by an angular distance β of approximately 60°, such that the five speaker-elements 2 together extend over an angular range of the plate 17 of about 300°. In the area where no speaker-element 2 is provided a cable pipe 18 is provided.
[0064] FIG. 2 shows a speaker 1 having two rows of speaker-elements 2. The speaker-elements 2 of the two rows are aligned with respect to each other. The speaker-elements 2 may be similar to the speaker-elements 2 of FIGS. 1A and 1B and the reader is referred to the above description of FIGS. 1A and 1B for a description thereof. The speaker 1 is shown in a front perspective view. The cables may be arranged at the back of the speaker 1 where no speaker-element 2 is provided. Other hardware of the speaker may for example be arranged under the two rows of speaker elements 2. The speaker 1 thus provided has a substantially cylindrical shape.
[0065] FIG. 3A shows a speaker 102 with a plurality of speaker-elements 2, which are spaced along and aligned with each other along an imaginary line L. For each speaker-element a membrane plane 3 substantially faces a membrane plane 3 of an adjacent speaker-element 2, as shown by membrane planes 3-1 and 3-2. In this example the imaginary line L is straight. FIG. 3B shows another embodiment of the speaker 201, which is similar to the speaker 102 of FIG. 3A, except for the line L which has a straight section L.sub.s and a curved section L.sub.c. The curve of the curved section L.sub.c curves away from the non-zero angle between two membrane planes 3-3 and 3-4 of a single speaker-element 2. The speaker elements 2 of speakers 101, 102 of FIGS. 3A and 3B comprise the above-described features, unless stated otherwise.
[0066] Although the invention has been described hereabove with reference to a number of specific examples and embodiments, the invention is not limited thereto. Instead, the invention also covers the subject matter defined by the claims, which now follow.
