Loudspeaker

Abstract

There is provided a speaker including a chassis, a diaphragm, a lead wire for providing an electrical signal, a driving unit, and a reinforcing element. The diaphragm is suspended from the chassis by one or more suspension elements. The drive unit is configured to move the diaphragm along a translation axis based on an electrical signal, and includes a magnet unit, a voice coil, and a voice coil holder. The reinforcing element is a rigid member configured to reinforce a portion of the diaphragm adjacent to the voice coil holder. A reinforcement element fits around the voice coil carrier and extends radially outward from the voice coil carrier with respect to the translation axis. The voice coil holder includes a conductive strip for conducting an electrical signal from the lead to the voice coil. The voice coil is electrically connected to the conductive strip via a first landing surface on the conductive strip, and the lead is electrically connected to the conductive strip via a second landing surface on the conductive strip. The first landing surface and the second landing surface are located on opposite sides of the reinforcing element with respect to the translation axis.

Description

[0001] This application claims priority to GB2207211.0 filed on May 17, 2022. Technical Field

[0002] The present invention relates to loudspeakers. Background Art

[0003] A conventional loudspeaker typically includes a drive unit configured to move a diaphragm along a translation axis based on an electrical signal. A typical drive unit is an electromechanical drive unit that includes a magnet unit configured to generate a magnetic field in an air gap and a voice coil attached to a voice coil former. The voice coil is configured to be located in the air gap when the diaphragm is at rest. When the loudspeaker is in use, the voice coil is energized (e.g., by passing an electrical signal through it) to generate a magnetic field that interacts with the magnetic field generated by the magnet unit. This causes the voice coil (and therefore the diaphragm) to move along the translation axis relative to the magnet unit with a force F=B*L*i, so that the diaphragm radiates sound in both forward and rearward directions parallel to the translation axis.

[0004] Shallow loudspeakers usually include a conical diaphragm, wherein the conical shape provides strength to the diaphragm. WO2004 / 017674 discloses a loudspeaker with a conical diaphragm which is shallow due to the addition of a reinforcement element (referred to as a "bridging element" in WO2004 / 017674) connected to the voice coil former and the diaphragm.

[0005] The present inventors have observed that a stiffening element such as a "bridging element" as described in WO2004 / 017674 facilitates the realization of a shallower loudspeaker by stiffening the portion of the diaphragm adjacent to the voice coil former. In particular, the diaphragm may incorporate a flattened base adjacent to the voice coil former which is stiffened by the stiffening element, thereby facilitating the realization of a shallower loudspeaker while avoiding compromising the sound quality. Thus, the overall height of the loudspeaker may be reduced.

[0006] However, as described in more detail below, the inventors have observed that loudspeaker designs with reinforcement elements (e.g. in WO2004 / 017674) may be susceptible to manufacturing problems during assembly of the drive unit. This may affect both the sound quality and the production costs of the loudspeaker. For example, the inventors have observed that manufacturing loudspeakers with reinforcement elements may result in the formation of channels between the reinforcement element and the voice coil former, through which water may penetrate. This is undesirable in outdoor applications, as such water penetration may affect the sound quality and potentially cause damage to the loudspeaker.

[0007] The present invention is designed in view of the above considerations. Summary of the invention

[0008] Therefore, a first aspect of the present invention provides:

[0009] A speaker, comprising:

[0010] chassis;

[0011] a diaphragm suspended from the chassis by one or more suspension elements;

[0012] Leads for providing electrical signals;

[0013] a drive unit configured to move the diaphragm along the translation axis based on an electrical signal, the drive unit comprising a magnet unit, a voice coil, and a voice coil former; and

[0014] a reinforcement element, which is a rigid component configured to reinforce a portion of the diaphragm adjacent to the voice coil former;

[0015] in:

[0016] A stiffening element is mounted around the voice coil former and extends radially outwardly from the voice coil former relative to the translation axis;

[0017] The voice coil former includes a conductive strip for conducting an electrical signal from a lead wire to the voice coil; and the voice coil is electrically connected to the conductive strip via a first landing surface on the conductive strip, and the lead wire is electrically connected to the conductive strip via a second landing surface on the conductive strip, wherein the first landing surface and the second landing surface are located on opposite sides of the reinforcement element relative to the translation axis.

[0018] Advantageously, the conductive strip located on the voice coil former allows the reinforcement element to fit more tightly around the voice coil former (i.e., the gap between the reinforcement element and the voice coil former is smaller). This is possible because the conductive strip can be thinner than the wire used to electrically connect the leads to the voice coil in conventional speakers. In conventional speakers with reinforcement elements, the reinforcement element must be significantly larger than the voice coil former in order to accommodate the presence of such wire extending between the voice coil former and the reinforcement element.

[0019] By assembling the reinforcement element closer to the voice coil former, the likelihood of glue dripping into the magnet assembly when the reinforcement element is glued to the voice coil former can be reduced. As a result, the likelihood of mechanical noise (known in the industry as 'hard bottoming sounds') when the speaker is in use can be reduced, thereby improving the overall sound quality of the speaker. In addition, for reasons discussed below, water ingress can also be reduced. Moreover, the use of conductive strips (rather than the more fragile insulated wires typically used in conventional speakers) helps to reduce the likelihood of damage to the electrical connection between the lead wires and the voice coil former during assembly.

[0020] Advantageously, for reasons discussed in more detail below, the loudspeaker according to the first aspect is also less susceptible to manufacturing problems during assembly.

[0021] The drive unit may be an electromagnetic drive unit comprising a magnet unit configured to generate a magnetic field in an air gap and a voice coil attached to a diaphragm, wherein the voice coil is configured to be located in the air gap when the diaphragm is at rest. When the loudspeaker is in use, the voice coil may be energized (e.g. by passing an electrical signal through it) to generate a magnetic field that interacts with the magnetic field generated by the magnet unit and causes the voice coil (and therefore the diaphragm) to move relative to the magnet unit along a movement axis. Such drive units are well known.

[0022] Because the reinforcement element is rigid and attached to the diaphragm adjacent to the voice coil former, it can be used to reinforce the diaphragm adjacent to the voice coil former, thereby helping to maintain the stiffness of the diaphragm while allowing the diaphragm to have a shallower depth in the axial direction.

[0023] The portion of the diaphragm adjacent to the voice coil former may be referred to as the base of the diaphragm. The diaphragm may include a tapered portion located radially outward of the base. The base of the diaphragm may be flattened relative to the tapered portion in the direction of the translation axis (e.g., the base may have an extent less than the tapered portion in the direction of the translation axis), in which case the diaphragm may be referred to as having a dished profile. The base may be flat or substantially flat relative to the translation axis.

[0024] The rigid reinforcement element may be attached directly to both the diaphragm and the voice coil former (e.g. Figure 1 The invention relates to a method of making the diaphragm and the voice coil former move in a substantially uniform manner (i.e., as shown in the drawings), because it helps to strengthen the connection between the diaphragm and the voice coil former (because the diaphragm and the voice coil former preferably move substantially together (i.e., "as one") when the loudspeaker is in use). However, arrangements are envisaged in which, for example, the stiffening element is attached directly to the diaphragm and not to the voice coil former, but the diaphragm and the voice coil former are configured to still move together (i.e., "as one") by virtue of the direct attachment between the diaphragm and the voice coil former.

[0025] The conductive strip may be a portion of conductive material having a width in a circumferential direction (relative to the translation axis) greater than a thickness in a radial direction (relative to the translation axis). The conductive strip may have a generally flat rectangular shape (which may be adapted to the curvature of the voice coil former) or any other shape extending from the first landing surface to the second landing surface along the translation axis.

[0026] In some examples, the conductive strip may be located on (e.g., attached to) the voice coil former. The conductive strip may be located on (e.g., attached to) the radially outwardly facing surface of the voice coil former. The conductive strip may be located on (e.g., attached to) the inwardly facing surface of the voice coil former. The conductive strip may be attached to the radially outwardly facing surface of the voice coil former, for example, by glue. The glue may be a thermosetting glue. Alternatively, any other mechanical means may be used to attach the conductive strip to the voice coil former.

[0027] In other examples, the conductive strip may be embedded in the voice coil former such that the conductive strip is flush with or recessed from a radially outward facing surface of the voice coil former.

[0028] The conductive strip may be a portion of a conductive (e.g., metal) foil located on (e.g., attached to) the voice coil former. In other examples, the conductive strip may be a conductive pad, conductive glue, or conductive spray. The conductive strip may, for example, be attached to a radially outwardly facing surface of the voice coil former. The conductive foil may be a copper foil. However, the conductive strip may be made of any conductive material. For example, the conductive strip may also be made of aluminum, gold, nickel, silver, or a conductive alloy.

[0029] The first landing surface and / or the second landing surface may be areas of the conductive strip for electrical connection to the voice coil and / or the lead, respectively. Preferably, the conductive strip is a single piece of material (e.g., a single piece of foil), and the first landing surface and / or the second landing surface are part of the single piece of material. However, in some examples, the first landing surface and / or the second landing surface may be made of a material different from the rest of the conductive strip. For example, the first landing surface and / or the second landing surface may include a pad made of a conductive metal different from the rest of the conductive strip. In some examples, the first landing surface and / or the second landing surface may include a mechanical formation for mechanically connecting to the voice coil and / or the lead, respectively. In some examples, the first landing surface and / or the second landing surface may be pre-tinned with solder in preparation for soldering connections to the voice coil and / or the lead, respectively.

[0030] The conductive strip may protrude less than 0.5 mm from the radially outwardly facing surface of the voice coil former (herein, "radially outwardly facing" may mean radially outward relative to the translation axis). More preferably, the conductive strip protrudes less than 0.3 mm, or more preferably less than 0.1 mm from the radially outwardly facing surface.

[0031] The distance between the first landing surface and the second landing surface can be at least 20% of the total height of the voice coil former measured along the translation axis. In some examples, the distance can be, for example, 20%, 30%, 40%, 50%, 60%, 70% or 80%.

[0032] This may help position the stiffening element between the first and second landing surfaces without interfering with the electrical connections between the voice coil and the first landing surface and between the leads and the second landing surface. However, other % values ​​are possible, for example if the voice coil has a short height as measured along the translation axis and the voice coil former is tall.

[0033] The outgoing wires of the voice coil may be soldered to the first landing surface of the conductive strip. Alternatively, the voice coil may be electrically connected to the first landing surface by another means such as a mechanical connection or conductive glue.

[0034] The lead wire may be welded to the second landing surface of the conductive strip. Alternatively, the lead wire may be electrically connected to the second landing surface by another means such as a mechanical connection or a conductive glue.

[0035] Having separate landing surfaces for the various electrical connections can facilitate assembly of the loudspeaker. For example, when a voice coil is soldered to a first landing surface on a conductive strip, the leads can then also be soldered to a second landing surface on the conductive strip at a later time without the risk of desoldering the first soldered connection between the voice coil and the conductive strip.

[0036] The voice coil may be welded to the first landing surface with a first welding material, and the leads may be welded to the second landing surface with a second welding material.

[0037] The presence of a first landing surface and a second landing surface means that incompatible (different) soldering materials can be used for the respective electrical connections without compromising the mechanical integrity of the connections. This can reduce production costs and increase the range of available materials from which the voice coil and leads can be made. For example, in some embodiments, a specific soldering aid designed for soldering aluminum wire can be used to electrically connect the voice coil to the first landing surface, and a second soldering aid designed for soldering standard copper wire can be used to solder the leads to the second landing surface.

[0038] In some examples, the voice coil can be made of one of copper, copper clad aluminum, or aluminum. Other conductive materials can also be used. Copper can be less expensive, while aluminum provides the benefit of weight reduction.

[0039] The reinforcing element may be made of metal. Preferably, the reinforcing element may be made of aluminum. Making the reinforcing element from metal may be cheaper than other materials, and aluminum is particularly preferred because it is lightweight.

[0040] The reinforcement element may be made of anodized metal. More preferably, the reinforcement element may be made of anodized aluminum. Conveniently, the anodized surface of the reinforcement element is non-conductive, resulting in less chance of damaging the loudspeaker due to a short circuit in the reinforcement element.

[0041] In other examples, the reinforcement element may be made of a polymer with reinforcement ribs. For example, the reinforcement element may be made of PC, PCABS, PCGF, PPGF, or any other polymer material combination. Reinforcement elements made of polymers can be lightweight and non-conductive. Therefore, there is less chance of damaging the speaker due to the reinforcement element creating a short circuit between the conductive strips, leads, or voice coil input and output.

[0042] The conductive strip may be partially covered by the insulating material. The insulating material may be attached to the voice coil former. The insulating material preferably leaves the first landing surface and the second landing surface exposed, ie does not cover the first landing surface and the second landing surface.

[0043] By covering the conductive strip with an insulating material, the electrical connection between the one or more leads and the voice coil can be protected from short circuits caused by contact with the reinforcement element, even when the reinforcement element is made of a conductive material.

[0044] The insulating material can be smaller than the conductive strip along the translation axis and cover the conductive strip in an area between the first landing surface and the second landing surface. In other examples, the insulating material can be larger than the distance between the first landing surface and the second landing surface along the translation axis and include an opening above the first landing surface and the second landing surface.

[0045] When the conductive strip is covered by the insulating material, the surface of the reinforcement element facing the voice coil former can be conductive. For example, the reinforcement element can be made from an anodized metal disk, which is then punched to create an opening, the (unanodized) inwardly facing surface of the opening being configured to receive the voice coil former. Forming the reinforcement element in this sequence (by anodizing the metal first) can be cheaper than if the fully formed reinforcement element (which has been punched to include the opening) is anodized.

[0046] The conductive strips and the insulating material may be made of a PCB (Printed Circuit Board) or a flexible PCB having exposed pads at the first and second landing surfaces.

[0047] The reinforcement element may have an internal cutout that corresponds to the shape of the voice coil former so that the reinforcement element fits around the voice coil former. For example, the voice coil former may be cylindrical with a circular cross-section (taken perpendicular to the translation axis) and the reinforcement element has a circular internal opening. In alternative embodiments, the voice coil former may have an oval, square, rectangular or any other shaped cross-section.

[0048] The reinforcement element may be glued to the voice coil former. The glue may be a thermosetting glue. The glue may be a "single component glue" or a "two component glue" (also referred to as "AB glue"). The two component glue may include an A component which is a resin and a B component which is used as a hardener.

[0049] The distance between the outer surface of the voice coil former and the inner surface of the reinforcement element may be no more than 0.5 mm, more preferably no more than 0.2 mm, more preferably no more than 0.1 mm over its maximum extent. This reduces the risk of glue dripping into the rest of the loudspeaker during assembly of the reinforcement element and the voice coil former. Achieving a small gap between the reinforcement element and the voice coil former is particularly beneficial in examples where the reinforcement element becomes asymmetrically positioned relative to the voice coil former (in radial direction) during assembly (which may result in a larger distance between the reinforcement element and the voice coil former on one side, which may allow glue to drip into the rest of the loudspeaker).

[0050] The lead wire may be a first lead wire for providing a first electrical signal, and the conductive strip may be a first conductive strip for conducting the first electrical signal to the voice coil.

[0051] The speaker may additionally include a second lead for providing a second electrical signal and a second conductive strip for conducting the second electrical signal to the voice coil. The second lead and the second conductive strip may have features as described above with respect to the first lead and the first conductive strip.

[0052] Thus, the voice coil can be electrically connected to the second conductive strip via a first landing surface on the second conductive strip, and the second lead can be electrically connected to the second conductive strip via a second landing surface on the second conductive strip, wherein the first landing surface and the second landing surface of the second conductive strip are located on opposite sides of the reinforcement element relative to the translation axis.

[0053] The presence of the first and second leads and the first and second conductive strips may help the loudspeaker accommodate different power configurations for the voice coil, for example, they may carry opposite polarities of the same electrical signal.

[0054] Additional pairs of leads and conductive strips are also possible.

[0055] Typically, the leads are provided in multiples of two, for example a loudspeaker may comprise two leads, four leads or six leads etc. The / each lead pair is configured to provide an electrical signal to a respective voice coil comprised in the loudspeaker.

[0056] However, it is worth noting that benefits can be obtained even if only one lead and conductive strip are used in accordance with the present invention.

[0057] Any of the features listed above with respect to the first lead and the first conductive strip may also apply to any additional leads and corresponding conductive strips.

[0058] A second aspect of the invention may provide a method of forming a loudspeaker according to the first aspect.

[0059] The method may include:

[0060] electrically connecting the voice coil to the first landing surface of the conductive strip;

[0061] Sliding the reinforcement element on the voice coil former;

[0062] attaching a reinforcement member to the diaphragm and the voice coil former; and

[0063] attaching a lead to the second landing surface of the conductive strip;

[0064] Therein, the reinforcement element is attached to the voice coil former at a location along the translation axis between the first landing surface and the second landing surface.

[0065] The step of electrically connecting the voice coil to the first landing surface may include attaching (eg, by soldering) outgoing wires from the voice coil to the first landing surface.

[0066] The step of electrically connecting the voice coil to the first landing surface may include soldering the lead wires from the voice coil to the first landing surface using a first soldering material, and the step of attaching the lead wires to the second landing surface may include soldering the lead wires to the second landing surface using a second soldering material.

[0067] The method may also include an initial step of forming the reinforcement element.

[0068] Forming the reinforcement element may comprise forming an opening in the disc-shaped element, for example by stamping.The disc-shaped element may be a metal disc, for example a disc of anodized aluminium.However, the reinforcement element may be formed from any material described in relation to the first aspect.

[0069] The method may additionally comprise electrically connecting the voice coil to the first landing surface of the second conductive strip, for example by attaching (eg soldering) a (second) lead-out wire from the voice coil to the first landing surface of the second conductive strip.

[0070] The method may additionally include attaching a second lead to the second landing surface of the second conductive strip, such as by welding the second lead to the second landing surface of the second conductive strip.The first and second landing surfaces of the second conductive strip may be located on opposite sides of the stiffening element relative to the translation axis.

[0071] The present invention includes any combination of the described aspects and preferred features unless such a combination is expressly impermissible or explicitly avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Embodiments and experiments illustrating the principles of the present invention will now be discussed with reference to the accompanying drawings, in which:

[0073] Figure 1 shows a cross-sectional view of a loudspeaker with a reinforcement element manufactured by the applicant according to conventional principles;

[0074] Figure 2a shows an exploded perspective view of a loudspeaker having a bridging element manufactured by the applicant according to conventional principles;

[0075] Figure 2b Shows Figure 2a a perspective view of an assembled speaker;

[0076] Figure 3 A diagram showing the configuration of a voice coil, voice coil former and reinforcement element of a conventional loudspeaker;

[0077] Figure 4a shows a cross-sectional view of an apparatus for testing a loudspeaker for water penetration;

[0078] Figure 4b Shown Figure 4a A picture of a portion of a conventional loudspeaker being tested by the device;

[0079] Figure 4c Shown along Figure 4b A top view of a conventional loudspeaker voice coil former of section AA;

[0080] Figure 5a A diagram showing a loudspeaker according to the invention;

[0081] Figure 5b Shows Figure 5a a diagram of a portion of a loudspeaker;

[0082] Figure 6a A photograph showing a voice coil and a voice coil former according to the present invention;

[0083] Figure 6b The invention shows a bridge element attached to the Figure 7 Photo of a voice coil and voice coil former;

[0084] Figure 7 A photograph showing a loudspeaker according to the invention;

[0085] Figure 8a shows a top view of a conventional loudspeaker voice coil former; and

[0086] Figure 8b A top view of a voice coil former according to the present invention is shown. DETAILED DESCRIPTION

[0087] Various aspects and embodiments of the present invention will now be discussed with reference to the accompanying drawings. Further aspects and embodiments will be apparent to those skilled in the art. All documents mentioned herein are incorporated herein by reference.

[0088] In the following examples, identical features are given corresponding reference numerals and corresponding descriptions may apply, unless such descriptions are expressly disallowed or explicitly avoided.

[0089] Figure 1 There is shown a cross-sectional view of a loudspeaker 100 having a reinforcement element 180 manufactured by the applicant according to conventional principles. Figure 1 The loudspeaker 100 may be understood as an optimized version of a loudspeaker implementing the principles of the loudspeaker described in WO2004017674.

[0090] The speaker 100 includes a chassis 110 , a diaphragm 120 , lead wires (not shown), a driving unit 130 , and a rigid reinforcing member 180 .

[0091] The diaphragm 120 is suspended from the chassis 110 by suspension elements. In this example, the diaphragm 120 is a cone suspended by two suspension elements, including a spider 122 (which may also be referred to as a "spider") and a surround 124 (which may also be referred to as a "roll suspension" or "roll edge").

[0092] The leads provide electrical signals from the input jack 172 to the drive unit 130. Typically, a speaker may include two or more leads configured to supply positive and negative electrical signals to the drive unit 130. In this example, the leads are integrated inside the damper 122.

[0093] The driving unit 130 is configured to move the diaphragm 120 along the translation axis 101 based on an electrical signal, and includes a magnet unit 160 , a voice coil 140 , and a voice coil former 150 .

[0094] The stiffening element 180 is attached to both the voice coil former 150 and the diaphragm 120 , and extends radially outward from the voice coil former 150 relative to the translation axis 101 (which may also be referred to herein as the “axial direction” or “axis of movement”).

[0095] In this example, the drive unit 130 is an electromechanical drive unit that includes a magnet unit 160 configured to generate a magnetic field in the air gap 132 and a voice coil 140 attached to a voice coil former 150. The voice coil 140 is configured to be located in the air gap 132 when the diaphragm 120 is at rest. When the loudspeaker 100 is in use, the voice coil 140 is energized (e.g., by passing an electrical signal through it) to generate a magnetic field that interacts with the magnetic field generated by the magnet unit 160. This causes the voice coil 140 (and therefore the stiffening element 180 and the diaphragm 120) to move relative to the magnet unit 160 along the translation axis 101 with a force F=B*L*i, so that the diaphragm 120 radiates sound in both forward and rearward directions parallel to the translation axis 101.

[0096] The voice coil 140 receives an electrical signal from the lead wire via an extra length of wire (not shown) running between the voice coil former 150 and the reinforcement member 180 to reach the voice coil 140. The voice coil former 150 may be covered with an insulating material (not shown).

[0097] A dust cover 126 is attached to the voice coil former 150 in front of the diaphragm 120 relative to the translation axis 101 to prevent dust or other foreign particles from entering the drive unit.

[0098] As described in WO2004017674, a rigid reinforcement element 180 (referred to as a bridging element in WO2004017674) helps reduce the height of the diaphragm 120 by reinforcing the base of the diaphragm 120 connected to the voice coil former 150. The reinforcement element 180 is rigidly connected to the voice coil former 150 so that the movement of the voice coil 140 and the voice coil former 150 in the air gap 132 is directly transferred to the diaphragm 120 (and is smoothed by the suspension elements including the spider 122 and the surround 124).

[0099] In this example, the voice coil former 150 is cylindrical and the stiffening element 180 is a disk including a circular opening for fitting around the voice coil former 150 (the opening may also be referred to herein as a "cutout"). However, other shapes of the voice coil former 150 and stiffening element opening are possible.

[0100] Figure 2a There is shown an exploded perspective view of a loudspeaker 100 having a reinforcement element 180 manufactured by the applicant according to conventional principles.

[0101] Figure 2a The loudspeaker 100 is typically assembled in a mass production facility by stacking components as shown in the axial direction 101 .

[0102] First, the magnet unit 160, which in this example includes the yoke 161, the spacer 164, the magnet 166 and the washer 168, is assembled and pressed into the metal frame 112. Next, the diaphragm 120 integrated with the surround 114 is then glued to the polymer frame 114. This assembly including the diaphragm 120, the surround 124 and the polymer frame 114 is then combined with the previously assembled metal frame 112 and magnet unit assembly 160. The polymer frame 114 and the metal frame 112 form the above-mentioned Figure 1 The chassis 110 is mentioned.

[0103] Next, the voice coil 140 and the voice coil former 150 are placed on a production centering jig (not shown) and positioned in the magnet unit 160 so that the voice coil 140 is correctly positioned in the air gap of the magnet unit 160. The voice coil former 150 is now the highest point in the partially assembled loudspeaker 100, as seen in the axial direction. In this example, the voice coil 140 is provided with outlet wires pre-soldered to pads provided on the voice coil former 150.

[0104] Next, the reinforcement element 180 is slid over the top of the voice coil former 150 until it is partially positioned between the top edge of the voice coil former 150 and the underlying voice coil 140. Typically, a thermosetting glue is then used to glue the reinforcement element 180 to the diaphragm 120 and the voice coil former 150. Glue is also used to attach the spider 122 to the reinforcement element 180 and the polymer basin frame 114. Other types of glue may alternatively be used to attach the reinforcement element 180 to the diaphragm 120, such as a one-component glue or a two-component glue.

[0105] In this example, two leads 170 are integrated into the spider. The operator solders the ends of the leads 170 to pads present on the voice coil former 150.

[0106] The final step is to place and glue the dust cover 126 onto the voice coil former 150 .

[0107] Figure 2b Shows Figure 2a 1 is a perspective view of the assembled speaker 100.

[0108] To support this typical assembly method, the reinforcement member 180 must be constructed with sufficient clearance to easily slide over the voice coil former 150 .

[0109] Figure 3 A diagram showing an example voice coil 140, voice coil former 150 and stiffening element 180 configuration that may be provided for assembling a loudspeaker manufactured according to conventional principles, such as Figure 2a and Figure 2b Speakers shown.

[0110] The voice coil 140 including N windings of wire is attached to the voice coil former 150 by soldering the outgoing wires 142 of the voice coil 140 to pre-tinned pads 152 provided on the voice coil former 150. The outgoing wires 142 of the voice coil 140 are typically provided glued to the outer surface of the voice coil former 150 and pre-soldered to the pads 152 in preparation for Figure 2a The reinforcing element 180 has a cutout 182 , which is provided to prepare for assembling the reinforcing element 180 on the voice coil former 150 .

[0111] During assembly of the loudspeaker, the voice coil 140 is positioned in the loudspeaker on the centering fixture as described above, and the stiffening element 180 is then mounted on the voice coil former 150 and attached to the voice coil former 150 at a location below the solder pad 152. Lead wires (not shown) are then typically soldered directly to the same solder pads 152 as the lead wires 142 of the voice coil 140.

[0112] Therefore, the cutout in the reinforcing element 180 must be made large enough to fit over the voice coil former 150, the outgoing wire 142 of the voice coil 140, and the existing solder connection between the outgoing wire 142 of the voice coil 140 and the solder pad 152. The inventors have observed that this larger cutout may cause manufacturing difficulties when the reinforcing element 180 is attached to the voice coil former 150 using glue. This is because the glue may drip into the resulting space between the reinforcing element 180 and the voice coil former 140, from which the glue may drip into the air gap of the magnet unit.

[0113] The inventors have observed that glue that has dripped into the air gap can be detected during an end-of-line sweep, where the completed loudspeaker is connected to a source and tested at high excursions. Glue dripping into the magnet unit may reduce the mechanical excursion of the loudspeaker, which may significantly reduce the resulting sound quality and cause mechanical noise known in the industry as "hard bottoming out". When operators assemble the loudspeaker, they have no visible control over this problem because the drive unit of the assembled loudspeaker is enclosed by the diaphragm and reinforcement element 180. The high temperatures typically found in a production environment may exacerbate this problem by reducing the viscosity of the glue, making it more likely to drip.

[0114] Additionally, the process of soldering the leads to the same pads 152 as the wires 142 of the voice coil 140 may make assembly of the speaker difficult and inefficient because the process of soldering the leads to the pads 152 may melt the existing solder and cause the existing connection between the wires 142 of the voice coil 140 and the pads 152 to desolder.

[0115] The winding wire of the voice coil 140 can be made of any conductive metal. However, copper wire is conventionally used. When the voice coil 140 is made of copper wire, the lead wire 142 and the lead wire of the voice coil 140 can be soldered to the pad 152 using typical tin solder and soldering aid.

[0116] However, in some examples, the winding wire of the voice coil 140 may preferably be made of aluminum or copper-clad aluminum to save weight (this is particularly preferred for outdoor applications as described below). In these examples, a specific soldering aid for pure aluminum wire may be used to solder the lead wires 142 of the voice coil 140 to the pads 152. However, the inventors have observed that such pure aluminum compatible soldering aids are incompatible with the copper soldering aids typically used to solder the lead wires to the pads 152. The inventors have observed mechanical failures during verification testing of assembled loudspeakers due to the use of incompatible soldering aids together.

[0117] Loudspeakers, especially subwoofers, with reinforcement elements are increasingly used in outdoor applications (which may also be referred to herein as the "fresh air" of "full 2pi" applications). In most conventional applications, subwoofers are housed in boxes to prevent acoustic shorting between the sound radiated in the forward direction from the speaker diaphragm and the sound radiated in the rearward direction from the speaker diaphragm. However, in outdoor applications, the loudspeakers are not housed in boxes.

[0118] For example, this is particularly popular in the automotive industry where, in order to reduce costs, the car body can be used as a baffle to separate the sound radiated in the forward direction from the sound radiated in the rearward direction.

[0119] In these full 2pi applications, there is no enclosed air behind the loudspeaker. Therefore, Qts = Qtc (where Qts is the total damping factor of the loudspeaker in free air and Qtc is the total damping factor of the loudspeaker when it is mounted in an enclosure), and Fs = Fc (where Fs is the resonant frequency of the loudspeaker in free air and Fc is the resonant frequency of the loudspeaker when it is mounted in an enclosure). Therefore, good acoustic performance can be achieved with a lower magnet system (BL) force factor. This means that the loudspeaker can be manufactured more cheaply. However, in order to achieve a loudspeaker with a lower force factor, it is preferred that the moving mass of the loudspeaker is as low as possible.

[0120] The voice coil can become the dominant moving mass in a loudspeaker, depending on the resistance of the voice coil, the winding height of the voice coil, the number of winding layers, and the winding wire material. This is especially true for subwoofers with long excursions. Therefore, it is particularly desirable to make voice coils in loudspeakers for outdoor applications from aluminum or copper clad aluminum wire rather than pure copper wire. However, the use of aluminum or copper clad aluminum wire may lead to problems caused by the use of incompatible welding methods as described above. In addition, the inventors have observed that pure aluminum wire and copper clad aluminum wire are more susceptible to corrosion when exposed to water, which may shorten the life of the loudspeaker.

[0121] In outdoor applications, it is preferred that the speaker has a dry area and a wet area. The magnet unit of the speaker should be in the dry area (e.g., inside the body of the vehicle), and the rear of the speaker (e.g., including the centering plate and dust cover and the back of the diaphragm) should be in the wet area (or outside the interior environment of the vehicle). Water should not be able to penetrate the speaker from the wet area to the dry area. Therefore, speakers used in outdoor applications usually need to pass a test to test the water penetration of the speaker.

[0122] Figure 4a A cross-sectional view of an apparatus that may be used to test a loudspeaker for water penetration is shown.

[0123] The speaker 100 under test is mounted in a vertical tube 134 or column so that the rear of the speaker 100 (including the magnet unit 160 and the base of the chassis 110) is at the bottom and the front of the speaker 100 (including the spider 122 and the dust cover 126) is at the top. The vertical tube 134 is then filled with water 132 to test the water penetration of the speaker 100 under test.

[0124] The height of the water 132 above the loudspeaker under test 100 can vary from 100 mm to 1000 mm, depending on the desired verification requirements. The water 132 generates high static forces on the soft parts of the loudspeaker under test 100, which include the fiber damper 122, the dust cover 126, the voice coil former 150, the wires (not shown) of the voice coil covered by insulating paper (not shown), the diaphragm 120, and the soft surround 124. These components represent a separation barrier between the desired dry area 138 of the loudspeaker 100 below these components and the wet area 136 above these components.

[0125] Mirror 135 is positioned below the speaker 100 under test to detect any water that has passed through. Water 132 is left for a defined amount of time (e.g., 1 hour, or up to 24 hours) to potentially penetrate the speaker 100 from the wet area 136 to the dry area 138. If water drops are detected on the mirror 135 after the defined amount of time, the speaker 100 has failed the test.

[0126] The inventors have observed that loudspeakers with reinforcement elements manufactured according to conventional principles fail this test.

[0127] Figure 4b Shown Figure 4a A picture of a portion of a conventional speaker being tested in the device.

[0128] To make the path of the water leak visible, a portion of the speaker, including the voice coil 140, the voice coil former 150, the dust cover 136, and the reinforcement element 180 glued to the voice coil former 150, is mounted inside a transparent PVC tube 134. The transparent PVC tube 134 is filled with black water 132, and a high-power LED is mounted inside the voice coil former 150 to allow the water leaking from the wet area 136 to the dry area 138 to be seen.

[0129] Figure 4b The shaded portion 144 visible in the 150 represents the path that water takes to leak along the voice coil former 150 towards the voice coil 140. The inventors believe from this data that water is able to penetrate a conventional loudspeaker via capillary action through the area around the outgoing wires of the voice coil 140 between the insulating paper and the voice coil former 150. This is explained in more detail below.

[0130] Figure 4c Shown along Figure 4bA top view of a voice coil former 150 from a conventional loudspeaker taken at section AA.

[0131] The voice coil lead 142 extends between the voice coil former 150 and the reinforcing element, as described above for Figure 3 The insulating paper 146 covers the voice coil former 150 and the outgoing wire 142. The voice coil former 150 is made of aluminum, Kapton, fiberglass, Kevlar or any other suitable material, and the outgoing wire 152 of the voice coil is glued to the voice coil former 150 using a thermosetting glue. The insulating paper 146 is glued to the voice coil former 150 above the outgoing wire 146, and the outgoing wire is soldered to a pre-tinned pad (not shown).

[0132] The thickness of the winding wire of the voice coil extending into the outgoing wire 142 may vary from 0.2 mm to 0.8 mm. The insulating paper 146 typically has a thickness of 0.05 mm to 0.15 mm. Therefore, it may be difficult or even impossible for the insulating paper 146 to be inserted without creating a free passage or opening 193 around the outgoing wire 142 (caused by the Figure 4c 142 in the case of a speaker intended for outdoor use. These free passages or openings 193, combined with the static pressure of the water 132 in the PVC tube 134, cause water to leak from the wet area to the dry area through the free passages 193 of the wire 142 around the voice coil by capillary action. This water leakage is an undesirable aspect of a speaker intended for outdoor applications.

[0133] The present invention is designed in view of the above considerations.

[0134] Figure 5a A diagram showing a loudspeaker according to the present invention is shown, which shows a voice coil 240, a voice coil former 250, a reinforcement element 280 and a diaphragm 220. Figure 5b A diagram showing a portion of a loudspeaker according to the invention showing Figure 5a The voice coil 240, the voice coil former 250, the reinforcement element 280 and the diaphragm 220 are provided.

[0135] The diaphragm 220 is suspended from the chassis 210 by one or more suspension elements. In this example, the spider 222 is attached to a stiffening element 280, which in turn is attached to the diaphragm 220, so that the base of the diaphragm 220 is suspended from the chassis 210. The surround 224 suspends the outer portion of the diaphragm 220 from the chassis 210.

[0136] Leads 270 are provided to provide electrical signals.

[0137] The drive unit 260 is configured to move the diaphragm 220 along the translation axis 201 based on the electrical signal. The drive unit 260 includes a magnet unit, a voice coil 240 and a voice coil former 250. The drive unit 260 is as described above for Figure 1 The electromechanical drive unit.

[0138] The reinforcement element 280 is rigid and is attached to both the voice coil former 250 and the diaphragm 220. The reinforcement element 280 extends radially outward from the voice coil former 250 relative to the translation axis 201 and may be made of metal, such as aluminum or anodized aluminum, or a polymer with reinforcement ribs.

[0139] The voice coil former 250 includes a conductive strip 290 for conducting electrical signals from the lead 270 to the voice coil 240. The voice coil 240 is electrically connected to the conductive strip 290 via a first landing surface 292 on the conductive strip 290, and the lead 270 is electrically connected to the conductive strip 290 via a second landing surface 294 on the conductive strip 290. The first landing surface 292 and the second landing surface 294 are located on opposite sides of the reinforcement element 280 relative to the translation axis 201.

[0140] A dust cover 226 is provided to prevent dust or other foreign particles from entering the drive unit 260 .

[0141] As previously described, the implementation of the conductive strip 290 located on the voice coil former 250 allows the reinforcing element 280 to be mounted closer to the voice coil former 250. This is possible because the conductive strip 290 can be made of a thinner material than the wire used to electrically connect the lead wire 270 and the voice coil 240 in conventional speakers (e.g., as described above for Figure 3 discussed) in more detail.

[0142] By fitting the reinforcement element 280 closer to the voice coil former 250, the likelihood of glue dripping into the magnet assembly when the reinforcement element 280 is glued to the voice coil former 250 can be reduced. Also, by eliminating the necessity to extend wires between the voice coil former 250 and the reinforcement element 280, the likelihood of damaging the insulation surrounding these wires when the reinforcement element 280 is slid over the voice coil former 250 during production is reduced.

[0143] The conductive strip 290 may protrude less than 0.5 mm from the surface of the voice coil former. More preferably, the conductive strip 290 protrudes less than 0.3 mm, or more preferably less than 0.1 mm from the surface of the voice coil former. For example, the conductive strip 290 may be made of a metal foil, such as a copper foil, which is glued to the surface of the voice coil former 250 using a thermosetting glue.

[0144] In these examples, the lead wire 242 and the lead wire 270 of the voice coil 240 are welded to the first landing surface 292 and the second landing surface 294, respectively. The presence of separate landing surfaces helps to facilitate different welding methods and materials for producing each welded joint. Thus, the voice coil 240 can be made of any conductive metal wire, such as copper, aluminum, or copper-clad aluminum.

[0145] Furthermore, having separate landing surfaces for various electrical connections may facilitate assembly of the loudspeaker 200. For example, when the voice coil 240 is soldered to the first landing surface 292 on the conductive strip 290, the lead 270 may then also be soldered to the second landing surface on the conductive strip 290 at a later time without the risk of the first soldered connection between the voice coil and the conductive strip 290 becoming desoldered.

[0146] Figure 6a A photograph showing a voice coil 340 and a voice coil former 350 according to the present invention is shown, Figure 6b The invention shows a bridge element attached to the Figure 6a A photograph of the voice coil 340 and the voice coil former 350 .

[0147] Figure 7 A photograph of a loudspeaker 300 according to the present invention is shown.

[0148] In these examples, the insulating paper 346 partially covers the conductive strip 390 to prevent the reinforcing element 380 from shorting the voice coil 340. The implementation of thin conductive strips 390 instead of wires can reduce the possibility of water entering between the insulating paper 346 and the voice coil former 350 in outdoor applications. This is discussed in more detail below.

[0149] Figure 8a A top view of a conventional speaker voice coil former 450 is shown, wherein an insulating paper 452 covers the outgoing wire 442 of the voice coil. Figure 4c As described, there are open channels 493 around the outgoing wires 442 between the insulating paper 452 and the voice coil former 450. These open channels 493 may allow water to penetrate the speaker via capillary action.

[0150] By comparison, Figure 8b A top view of a voice coil former 450 according to the present invention is shown, which has a first conductive strip 490a and a second conductive strip 490b located on a radially outer surface of the voice coil former 450. The first conductive strip 490a and the second conductive strip 490b are covered by an insulating paper 452. The first conductive strip 490a and the second conductive strip 490b are much thinner than the wire used in conventional speakers, thereby allowing the insulating paper 452 to be more tightly assembled on the voice coil former 450 around the first conductive strip 490a and the second conductive strip 490b.

[0151] The inventors have observed that this produces a loudspeaker that performs better than conventional loudspeakers in terms of preventing water penetration. Furthermore, since the voice coil and the wires exiting the voice coil are less likely to become wet, the likelihood of corrosion of the aluminum or copper clad aluminum wire that may be preferably used to make the voice coil winding is reduced. As a result, the loudspeaker may operate more reliably in outdoor applications, and the available range of materials from which the voice coil may be made is expanded.

[0152] In some examples, the outlet wire 240 and the first landing surface 292 of the voice coil 240 may be covered with epoxy glue to further reduce the risk of corrosion to the winding wire when the winding wire is made of aluminum or copper clad aluminum.

[0153] The features disclosed in the above description, the following claims or the accompanying drawings (expressed in their specific form or as means for performing the disclosed functions or as methods or processes for obtaining the disclosed results) may, where appropriate, be used alone or in any combination of these features to implement the invention in its different forms.

[0154] Although the present invention has been described in conjunction with the above exemplary embodiments, many equivalent modifications and variations will be apparent to those skilled in the art when this disclosure is given. Therefore, the above exemplary embodiments of the present invention are considered to be illustrative rather than restrictive. Various changes may be made to the described embodiments without departing from the spirit and scope of the present invention.

[0155] To avoid any doubt, any theoretical explanations provided herein are provided to enhance the reader's understanding. The inventors do not wish to be bound by any of these theoretical explanations.

[0156] Any section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

[0157] Throughout the specification (including the following claims), unless the context requires otherwise, the words "comprise", "comprising" and variations such as "include", "it includes" and "it includes", will be understood to implicitly include the stated integers or steps or combinations of integers or steps but not to exclude any other integers or steps or combinations of integers or steps.

[0158] It must be noted that the singular forms "a", "an", and "the" used in this specification and the appended claims include plural referents unless the context clearly indicates otherwise. Ranges may be expressed herein as from "about" one particular value and / or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when a value is expressed as an approximation by using the antecedent "about", it should be understood that the particular value forms another embodiment. The term "about" in relation to a numerical value is optional and means, for example, + / - 10%.

[0159] References

[0160] Many publications are cited above to more fully describe and disclose the present invention and the current state of the art to which the present invention belongs. The complete citations of these references are provided below. The entire contents of each of these references are incorporated herein.

[0161] WO2004017674.

Claims

1. A loudspeaker, comprising: chassis; a diaphragm suspended from the chassis by one or more suspension elements; Leads for providing electrical signals; a driving unit configured to move the diaphragm along a translation axis based on the electrical signal, the driving unit comprising a magnet unit, a voice coil, and a voice coil former; as well as a reinforcing element, which is a rigid component configured to reinforce a portion of the diaphragm adjacent to the voice coil former; in: The reinforcement element is mounted around the voice coil former and extends radially outward from the voice coil former relative to the translation axis; The voice coil former includes a conductive strip for conducting the electrical signal from the lead wire to the voice coil; and The voice coil is electrically connected to the conductive strip via a first landing surface on the conductive strip, and the lead is electrically connected to the conductive strip via a second landing surface on the conductive strip, wherein the first and second landing surfaces are located on opposite sides of the reinforcement element relative to the translation axis.

2. The loudspeaker according to claim 1, wherein The conductive strip has a width in a circumferential direction relative to the translation axis that is greater than a thickness in a radial direction relative to the translation axis.

3. A loudspeaker according to any one of the preceding claims, wherein: The conductive strip protrudes less than 0.5 mm from the radially outwardly facing surface of the voice coil former.

4. A loudspeaker according to any one of the preceding claims, wherein: The distance between the outer surface of the voice coil former and the inner surface of the reinforcing element is no greater than 0.5 mm over its maximum length.

5. A loudspeaker according to any one of the preceding claims, wherein: A distance between the first landing surface and the second landing surface along the translation axis is at least 20% of an overall height of the voice coil former.

6. A loudspeaker according to any preceding claim, wherein: The lead wire of the voice coil is welded to the first landing surface of the conductive strip, and the lead wire is welded to the second landing surface of the conductive strip.

7. The loudspeaker according to claim 6, wherein: The outlet wire of the voice coil is welded to the first landing surface with a first welding material, and the lead wire is welded to the second landing surface with a second welding material.

8. A loudspeaker according to any preceding claim, wherein: The conductive strips are made of conductive foil.

9. A loudspeaker according to any preceding claim, wherein: The conductive strip is glued to the voice coil former.

10. A loudspeaker according to any preceding claim, wherein: A region of the conductive strip between the first landing surface and the second landing surface is covered with an insulating material.

11. A loudspeaker according to any preceding claim, wherein: The voice coil is made of one of copper, copper clad aluminum or aluminum.

12. A loudspeaker according to any preceding claim, wherein: The reinforcing element is made of anodized metal.

13. A loudspeaker according to any preceding claim, wherein: The lead wire is a first lead wire for providing a first electrical signal, and the conductive strip is a first conductive strip for conducting the first electrical signal to the voice coil; and The loudspeaker further comprises a second lead for providing a second electrical signal, and the voice coil former comprises a second conductive strip for conducting the second electrical signal to the voice coil; wherein the voice coil is electrically connected to the second conductive strip via a first landing surface on the second conductive strip, and the second lead is electrically connected to the second conductive strip via a second landing surface on the second conductive strip, wherein the first landing surface and the second landing surface of the second conductive strip are located on opposite sides of the reinforcement element relative to the translation axis.

14. A method of forming a loudspeaker according to any preceding claim, comprising: electrically connecting the voice coil to the first landing surface of the conductive strip; Sliding the reinforcing element on the voice coil former; attaching the reinforcement element to the diaphragm and the voice coil former; as well as attaching the lead to the second landing surface of the conductive strip; wherein the reinforcement element is attached to the voice coil former at a location along the translation axis between the first landing surface and the second landing surface.

15. The method according to claim 14, wherein: The step of electrically connecting the voice coil to the first landing surface includes welding leads from the voice coil to the first landing surface using a first welding material, and the step of attaching the leads to the second landing surface includes welding the leads to the second landing surface using a second welding material.

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