Loudspeaker

<b>Technical field</b>

The invention is concerned with the training of speakers, especially with the formation of drive systems for such speakers as well as the mutual assignment of such speakers.

<b>State of the art</b>

According to the prior art, it is known to provide drive systems of loudspeakers so that a permanent magnet is connected with the so-called yoke or yoke parts, wherein on the yoke members, an annular gap is left, in which later the voice coil connected to the speaker membrane is immersed. Such an arrangement, which comprises an axially magnetized to the longitudinal axis of the magnet system the permanent magnet is, for example, shown in DE-A-4,113,017th Magnet systems with two permanent magnets show the documents DE-A-4234069 and DE-A-4,225,156th

Here with magnet systems are known which to the longitudinal axis of the magnet system having radially magnetized permanent magnets. These permanent magnets are either integrally formed or consist of a series of permanent magnet segments. Such arrangements are known for example from WO 93/03586. Also in these arrangements yoke parts are present, which guide the magnetic flux provided by the permanent magnet, so that the annular gap sufficient induction is provided.

both the elaborate production and the high weight and the large volume is perceived in these systems or loudspeakers as disadvantageous. The invention is therefore based on the problem to provide a magnet system which avoids the disadvantages of the prior art.

<b>Summary of the Invention</b>

This problem is solved with the features of claim. 1 Advantageous training and advanced of the invention are the claims 2 - 7 removed.

Basic idea of ​​the present invention is to use the output from a stray flux radialmagnetisierten permanent magnets for driving a voice coil. This makes it possible to form the receiving parts for the permanent magnet made of a paramagnetic or diamagnetic material. This has the consequence that a considerable space and weight saving is achieved because the geometric requirements for the back yoke parts, which must be considered by the prior art for conducting the magnetic flux in these parts, according to the invention are insignificant. The production of magnetic systems is greatly simplified, since steps which are necessary for connecting the usual back yoke parts according to the prior art be omitted, according to the invention. Rather, the receiving part according to the invention only forms the rear termination of the speaker or a supporting structure for the permanent magnet and the other components of the speaker.

Since a cone speaker usually has a loudspeaker frame, which is connected to the magnet system can be since the receiving part according to the invention has no function with respect to the magnetic flux and with regard to the use of the leakage flux also should not have, one-piece units from receiving part and loudspeaker frame manufactured very inexpensively.

Suitable materials for forming receiving parts or units of the receiving part and loudspeaker frame to plastics, metals and metal alloys offer. to use for the training of female parts in the aforementioned sense metal, since these materials the same time ensure good heat dissipation in the region of the drive system of the speaker is particularly advantageous.

A particularly effective use of the output from the permanent magnet flux leakage is provided when the magnet system is formed according to claim fifth In this case, the output from the permanent magnet flux leakage from both coils is used to drive a membrane.

In order to increase the pressure required to drive the membrane leakage flux, two or more permanent magnets axially spaced apart in the direction of the longitudinal axis of the magnetic system can be arranged. In such an arrangement each of these permanent magnets can be surrounded on its inner side and / or outer shell side of a voice coil. If additional voice coil for driving, for example, be used a membrane, it is necessary to rigidly connect these voice coil together. Also magnet system according to the invention can be modified so that for example, all disposed on an inner lateral surface of the permanent magnet coil for driving a diaphragm and disposed on all of the other lateral surface coils are used to drive a different membrane.

Very particularly advantageous is the design of the loudspeaker is according to claim 7. The respective voice coil support is of approximately tubular and the first end of the voice coil bobbin with a first membrane and the second end of this voice coil bobbin is connected to a second membrane and are the two membranes, their suspension, etc. formed completely identical, such an arrangement can be used as a dipole antenna to produce, for example, a diffuse sound field for Dolby surround playback. Such diffuse sound fields are generated according to the prior art in that two completely similar but inverse polarity reversal together speakers are used with separate volumes. With such arrangements but the desired effects are only possible when the two speakers a to 1 - have identical 2 dB playback frequency response. If these conditions are not complied with, the respective sound event is perceived as a front or as coming from behind. As appreciated, the identity can be ensured only through considerable effort in the production in the playback frequency response. However, if the arrangement for generating a diffuse sound field formed according to claim 7, be deviations, which are caused for example by production membrane differences or unavoidable manufacturing differences in assembling the speakers, compensated or averaged that the manufacturing-related deviations of all membranes etc. mechanical by a coupling of the two membranes are effective in every operating state.

Summary of the figures

Show it:<dl id="dl0001" compact="compact"><dt>figure 1</dt><dd>a section through a speaker;</dd><dt>figure 2</dt><dd>a perspective view of a permanent magnet;</dd><dt>figure 3</dt><dd>is another illustration of Figure 1;</dd><dt>figure 4</dt><dd>is another illustration of Figure 1;</dd><dt>figure 5</dt><dd>a section through a permanent magnet arrangement; and</dd><dt>figure 6</dt><dd>is another illustration of FIG. 1</dd></dl>

<b>Ways of carrying out the invention</b>

The invention will now be explained in more detail with reference to FIGS.

In Figure 1, a loudspeaker (10) is shown in section. This speaker (10) is substantially of a receiving part (11), a permanent magnet (12) and a membrane (13). In the present embodiment, the receiving portion (11) of a loudspeaker frame (11a) and a mandrel (11b) is formed. As the material of the parts (11a and 11b) of polycarbonate was used. A limitation to this material is not involved. Rather, in another - not illustrated example - other plastics, such as ABS, or metals, for example aluminum, are used as materials, provided that these materials have para- or diamagnetic properties. It is essential that at least the dome (11b), ie the part which directly with the permanent magnet (12) is in physical connection, is made of a paramagnetic or diamagnetic material, by the direct contact that from the permanent magnet (12) outgoing field not to weaken. Combinations are not excluded from the invention, which have a mandrel (11b) of a paramagnetic or diamagnetic material and a loudspeaker frame (11a) of a ferro-magnetic material.

As appreciated, but make combinations of the parts (11a, 11b) of paramagnetic or diamagnetic materials the most advantageous training. In addition to the neutral effect of such combinations in the Sreufeld the permanent magnet (12), such combinations are very inexpensive in the production , The latter applies in particular if the receiving part (11) is integrally formed. Such integral formation of a receiving part (11) is shown in FIG. 4

The mandrel shown in Figure 1 (11b) is circular, said the basket (11a) facing away from the end of the mandrel (11b) towards the basket (11a) proximal end having a smaller diameter. This configuration of the mandrel (11b) is used for the positive reception of the annular shaped permanent magnet (12). Just for completeness it should be noted that the mandrel (11b) is not necessary that the inner diameter of the permanent magnet must (12) filled in completely or partially. A configuration in which the mandrel (11b) of the inner diameter of the permanent magnet (12) does not completely fill is shown in FIG. 4

In the basket (11a) shown in FIG 1 a conical membrane (13) is used. The upper end of the membrane (13) is connected by means of a bead (14) to the basket (11a). The lower end of the membrane (13) includes a voice coil support (15) which projects into the coated by the membrane (13) space. To the outer surface of the voice coil support (15) the Sehwingspule (16) is wound. Although this arrangement of the voice coil (16) on the outer surface of the voice coil bobbin (15) from a manufacturing standpoint it is advantageous, it can make better use of the leakage flux can be necessary to place the voice coil (16) on the inner casing of the voice coil bobbin (16) (the latter is shown in Figure . 1 not shown).

Feiner is a centering diaphragm (17) is provided, which with the basket (11a) and the diaphragm (13) is connected and which maintains the voice coil (16) centrally to the longitudinal axis of the magnet system or the speaker (10).

In addition, the mandrel (11b), the permanent magnet (12) and the voice coil (16) by means of a dust cap (18) can be covered. This dust cap (18) has to protect conventional speakers (10) on the object, the narrow annular gap before particle accumulations. This object also has the dust cap (18) used in the system according to the invention, although the distances between the voice coil (16) and the permanent magnet (12) are not so critical in the inventive systems which utilize the leakage flux, so that when the dust protection does not exist, the accumulating particles are of subordinate importance.

As already indicated several times, the drive of the current flowing through voice coil (16) is carried out in the stray field which is produced by a radialmagnetisierten permanent magnet (12). Therefore, in the exemplary embodiment shown in FIG. 1, the north pole (N) at the outer surface (19) and the south pole (S) to the inner surface (20) of the permanent magnet (12).

As appreciated, the induction of radialmagnetisierten permanent magnet (12) along the lateral surfaces 19/20 is constant, so that the voice coil (16) over its entire displacement path moves in a uniform magnetic field, which ultimately leads to a very linear operation of the loudspeaker ( 10).

The formation of permanent magnets (12) is not limited to the one-piece circular ring shape. With FIG. 2, a permanent magnet (12) is shown, which is octagonal formed and consists of a succession of permanent magnet segments (12a-h). Each of these segments (12a-h) is also magnetized radially as the segment (12a) indicated. The use of permanent magnets (12) in segments has the advantage that plate material can be used which can be easily magnetized opposite circular ring-shaped permanent magnet (12). The octagonal shape shown in Fig. 2 of the permanent magnet (12) is exemplary only.

In another - embodiment not shown - may be cuboid formed by the juxtaposition of only 4 segments of the permanent magnet (12).

In Fig. 3, a loudspeaker (10) is shown, which has deviated from the design according to FIG. 1 via two voice coil support (15 and 15 '). These two voice coil carrier (15, 15 ') are connected by a circular ring disc (21) with mutual spacing. In addition, each of the two voice coil support (15, 15 ') having a voice coil (16, 16') provided.

The mandrel (11b) facing away from the basket (11a) end with a disc (22), which is also made of a paramagnetic or diamagnetic material. The bottom (23) of the disc (22) is connected to a radialmagnetisierten Dauelmagneten (12) in a circular ring shape. The sake of completeness it should be noted that the disc (22) can also be formed from a ferro-magnetic material, although such a choice of material results in a slightly worse degree of efficiency.

Since the inner diameter of the annular permanent magnet (12) is larger than the outer diameter of the mandrel (11b), and both parts are constructed coaxially to each other, an "air gap" (24) is formed. In these "air gap" (24) of the coil (16) immersed connected voice coil support (15), while at the voice coil support (15 ') disposed voice coil (16') the outer lateral surface (19) of the permanent magnet (12) at a distance edged.

Since the two coils 'have the same winding direction and thus the current flow direction in the two coils (16 16, (16, 16)' is the same), 3 of the leakage flux is in contrast to the embodiment according to FIG. 1 in the formation of FIG. Considerably better for driving the diaphragm (13) utilized. The latter conditions are also useful in coils (16, 16 ') with opposite winding sense erziehlbar when the two coils (16, 16') inverse to each other with a sound source (not shown) are reversed.

The sake of completeness it should be noted that in the preparation of, for example, in Fig. 1 and 3, loudspeakers (10), the devices can be used without any major modifications, which are also used for the preparation of assemblies in accordance with DE-A-4,113,017th In particular, also in the arrangements according to the invention for aligning and securing the diaphragm (13) in the basket (11a) is usually used centering sleeves, which for the manufacture of speakers (10) between the pole core {mandrel (11b) and permanent magnet (12)} and the be voice coil support (15) are used, is used.

The training according to FIG. 3 with the two voice coils (16, 16 ') but is not limited to the driving of only one membrane (13). Rather, the stray flux of the radialmagnetisierten permanent magnet (12) can also be used to drive different membranes (13, 13 ') can be used. Such ratios are shown in Fig. 4. Here, rather than their representation according to FIG. 1, the permanent magnet ring (12) on the mandrel (11b) placed. Between the inner circumferential surface (20) of the radially magnetized permanent magnet ring (12) and the mandrel (11b) there is an "air gap" (24), in which a voice coil bobbin (15 ') provided with a voice coil (16') is wound is immersed. The upper end of the voice coil support (15 ') is provided with a dome-shaped diaphragm (13'). The outer edge of the dome-shaped membrane (13 ') is connected to the upper end of the permanent magnet (12).

If this voice coil (16 ') (supplied with an audio signal of a sound source, so the membrane 13)' may be used, for example, to emit high-frequency sound signals, while the membrane (13) is used for radiating medium-frequency sound signals, for example. To phasality by the two membranes (13, 13 ') (to achieve radiated Teiltonfrequenzen, both voice coils 16, 16) should' be reversed in this embodiment, inversely related to the sound source, when both coils (16, 16 '), for example, for manufacturing reasons have the same winding sense.

Fig. 5 shows a comparison with FIG. 1 modified Dorn-permanent magnet combination. Here, two permanent magnets (12, 12 ') at a mutual axial distance on the mandrel (11b) is provided. Each of these permanent magnets (12, 12 ') is radially magnetized, with like poles of the two permanent magnets (12, 12') point in the same direction. The express shell surfaces (19) of the two permanent magnets (12, 12 ') is a voice coil support (16) arranged next to which is also at a mutual axial distance two voice coils (16,16' are fixed).

Such an arrangement should be selected when the leakage flux only a permanent magnet (12) alone is sufficient not to drive a membrane (13). If the two coils (16, 16 ') for driving only be used a membrane (13), the current flow direction must in both voice coils (16, 16') have the same direction.

By the voice coil support (15) intersecting double-dotted chain lines, it is indicated that the arrangement also for the propulsion of various membranes (13) shown in Fig. 5 can be used if the two voice coils (16, 16 ') not on a common voice coil support ( 15) are arranged, but independent voice coil support (15 '') have.

It is also not necessary that the mandrel (11b) according to FIG. 5 completely the inner diameter of the two permanent magnets (12, 12 ') fills. Rather, the mandrel shown in Fig. 5 (11b) may also be formed in accordance with the embodiments shown in FIGS. 3 and 4 modified.

For completeness 'sake it is noted that a mandrel-permanent-magnet combination shown in connection with Figures 1 and 5 can be very advantageously formed, characterized in that the or each permanent magnet (12, 12') are inserted into an injection mold, so that the connection of the permanent magnets can be carried out (12, 12 ') simultaneously with the forming of the mandrel (11b) or from mandrel (11b) and basket (11a) existing recording (11).

In Fig. 6, a dipole antenna (10 ') is shown, the left and right of the double-dotted broken line one speaker (10' showing '). Each of these speakers (10 '') essentially corresponds to one in DE-A-4,113,017 (Fig. 1) speaker shown. Notwithstanding this, however, the magnet system is formed in FIG. 6. This is characterized in that it is formed by a radially magnetized permanent magnet (12). Since the first end (25) of the voice coil bobbin (15) with a membrane (13) and the second end (25 ') of the voice coil carrier (15) is provided with another membrane (13'). Is now connected to the voice coil support (15) connected to the voice coil (16) supplied with an audio signal, the voice coil (16) and with it via the voice coil support (15) moves each of the two membranes (13, 13 ') in direction of the arrow. This means that an air compression takes place at the membrane (13 '), while an air dilution is due to the diaphragm (13). Since, however, both membranes (13, 13 ') resistors are coupled via the common voice coil support (15), to act for example on the membrane (13') present and the free stroke of said membrane (13 ') affecting also to the stroke of the membrane from (13), so that they will receive a the membrane (13 ') identical stroke behavior. This meant that both diaphragms (13,13 ') proposed identical reproduction frequencies, which is to generate a diffuse sound field is of considerable importance.

Finally it should be noted that in another - can be used embodiment in an arrangement according to Figure 6, the permanent magnet rings shown in Figure 5 (12, 12 ') - is not shown... Also, an arrangement shown in FIG. 6 are modified so that as shown in FIG. 4, the two in Fig. 6 membranes (13, 13 ') of two respectively with lateral distance from the inner and outer circumferential surface (19, 20) of the permanent magnet ( 12) arranged voice coil (16, 16 are driven ').