PATENT DOCUMENT

Publication Number: US-10555085-B2
Application Number: US-201715625302-A
Country: US
Kind Code: B2

Title: High aspect ratio moving coil transducer

Abstract:
A voice coil former including a first portion having a planar region and an out-of plane region that extends outside a plane of the planar region, and wherein a length dimension of the first portion is at least two times greater than a width dimension of the first portion. The former further including a second portion extending from the first portion in a direction perpendicular to the plane of the first portion, the second portion being integrally formed with the first portion and dimensioned to support a voice coil thereon.

Claims:
What is claimed is: 
     
       1. A voice coil assembly comprising:
 a voice coil former having a first portion and a second portion, the first portion having a planar region surrounding an out-of plane region that extends outside a plane of the planar region, and wherein a length dimension of the first portion is at least two times greater than a width dimension of the first portion; and 
 the second portion extending from the first portion in a direction perpendicular to the plane of the first portion, the second portion being integrally formed with the planar region of the first portion surrounding the out-of-plane region and dimensioned to support a voice coil thereon. 
 
     
     
       2. The voice coil assembly of  claim 1  wherein the first portion is operable to vibrate and output sound in response to an electrical audio signal input to a voice coil positioned around the second portion. 
     
     
       3. The voice coil assembly of  claim 1  wherein the planar region is entirely within a same plane and completely surrounds the out-of plane region, and the planar region is solid. 
     
     
       4. The voice coil assembly of  claim 1  wherein the planar region comprises at least one opening formed therethrough. 
     
     
       5. The voice coil assembly of  claim 1  wherein the out-of-plane region is a groove that runs parallel to the length dimension of the first portion, and wherein the groove extends from the plane of the first portion in a same direction as the second portion. 
     
     
       6. The voice coil assembly of  claim 1  wherein the out-of-plane region is a first groove, the voice coil former further comprising a second groove, and wherein the first groove and the second groove extend from the plane of the first portion in an opposite direction as the second portion. 
     
     
       7. The voice coil assembly of  claim 1  wherein the voice coil former comprises a plurality of out-of-plane regions, and the plurality of out-of-plane regions have a length dimension that is parallel to the width dimension of the first portion. 
     
     
       8. The voice coil assembly of  claim 1  wherein the voice coil former comprises a plurality of out-of-plane regions, and the plurality of out-of-plane regions comprise a same size and shape. 
     
     
       9. The voice coil assembly of  claim 1  wherein the first portion is defined by four sides, and the second portion extends from only two of the four sides. 
     
     
       10. The voice coil assembly of  claim 1  further comprising:
 a gusset between the first portion and the second portion, wherein the gusset is dimensioned to geometrically stiffen the voice coil former. 
 
     
     
       11. The voice coil assembly of  claim 1  further comprising:
 a stiffening plate positioned on the first portion. 
 
     
     
       12. The voice coil assembly of  claim 1  wherein the first portion and the second portion are formed from a same sheet of material. 
     
     
       13. A high aspect ratio voice coil assembly comprising:
 a voice coil former having a sound radiating portion and a sidewall extending perpendicular to a plane of the sound radiating portion for positioning of a high aspect ratio voice coil thereon, the sound radiating portion being integrally formed with the sidewall; and 
 a stiffening member integrally formed with the voice coil former from a same sheet of material. 
 
     
     
       14. The high aspect ratio voice coil assembly of  claim 13  wherein the voice coil comprises an aspect ratio of at least 3.0. 
     
     
       15. The high aspect ratio voice coil assembly of  claim 13  wherein an angle formed between the sound radiating portion and the sidewall is ninety degrees or less. 
     
     
       16. The high aspect ratio voice coil assembly of  claim 13  wherein the sound radiating portion comprises a planar region that is entirely within the plane of the sound radiating portion, and the stiffening member comprises an out-of-plane region that protrudes outside the plane of the planar region and is surrounded by the planar region. 
     
     
       17. The high aspect ratio voice coil assembly of  claim 13  wherein the stiffening member comprises a hem formed at an end of the sidewall, and the hem is dimensioned to geometrically stiffen the voice coil former. 
     
     
       18. The high aspect ratio voice coil assembly of  claim 13  further comprising a plurality of indentations formed within adjoining portions of the sound radiating portion and the sidewall. 
     
     
       19. The high aspect ratio voice coil assembly of  claim 13  wherein the sidewall comprises at least one opening that extends through the sidewall. 
     
     
       20. The high aspect ratio voice coil assembly of  claim 13  wherein a material of the sound radiating portion, the sidewall and the stiffening member comprises aluminum, titanium, stainless steel or carbon fiber. 
     
     
       21. The high aspect ratio voice coil assembly of  claim 13  further comprising:
 a frame; 
 a magnet assembly coupled to the frame, wherein the former is suspended from the frame by a suspension member and positioned over the magnet assembly; and 
 the voice coil is positioned around the sidewall of the voice coil former. 
 
     
     
       22. The high aspect ratio voice coil assembly of  claim 13  wherein a length of the stiffening member is parallel to a length of the sound radiating portion.

Description:
FIELD 
     An embodiment of the invention is directed to a high aspect ratio moving voice coil transducer with improved voice coil stability, more specifically, a high aspect ratio speaker assembly having a single piece high aspect ratio former for improving voice coil stability. Other embodiments are also described and claimed. 
     BACKGROUND 
     In modern consumer electronics, audio capability is playing an increasingly larger role as improvements in digital audio signal processing and audio content delivery continue to happen. In this aspect, there is a wide range of consumer electronics devices that can benefit from improved audio performance. For instance, smart phones include, for example, electro-acoustic transducers such as speakerphone loudspeakers and earpiece receivers that can benefit from improved audio performance. The loudspeakers may include a moving coil motor to drive sound output. The moving voice coil motor may include a diaphragm, voice coil positioned around a former and magnet assembly positioned within a frame. In some instances, the moving voice coil motor assembly may have a relatively high aspect ratio of length to width that can lead to an increased risk of stiffness and stability problems such as an increase in the severity of the moving assembly&#39;s rocking mode. For example, as the aspect ratio of the diaphragm increases (i.e. the ratio of the long dimension, length, to the short dimension, width, increases), the risk of bowing of the former and/or voice coil and/or rocking or twisting along the length dimension of the assembly may increase. Such out of phase movements can result in undesirable acoustic effects, such as acoustic cancellation or distorted sound pressure output. 
     SUMMARY 
     An embodiment of the invention is a transducer assembly having high aspect ratio (length:width&gt;3), for example a long and skinny loudspeaker driver with improved stability of the voice coil geometry (to keep the long edges of the voice coil straight) and high bending stiffness which allows the driver to reach high frequencies before partial vibration (breakup modes) occur. In one embodiment, the assembly includes a single piece former onto which the voice coil is wound, and which has the shape of an inverted, U channel extrusion (with a flattened bottom). The U shaped channel can be made from materials such as aluminum, stainless steel, carbon fiber, or the like. The former may be made by stamping and folding a sheet of the desired material into the desired former shape. In one embodiment, an exemplary thickness of the overall former may be from about 25 to 75 microns. In addition, in some embodiments, the former may include stiffening features such as an out-of-plane region along a top side (e.g. a rib or channel), gussets and/or rounded edges. Each of these stiffening features may be formed from the same sheet of material as former so that additional parts and labor are not required. In addition, in some embodiments, a stiffening plate may also be attached to the top side of the former to increase bending stiffness further. In still further embodiments, recognizing that rocking modes is another significant challenge in high aspect ratio transducers the assembly may include a secondary suspension member along the width (or short) edges. 
     Representatively, in one embodiment, the invention is directed to, a voice coil former including a first portion having a planar region and an out-of plane region that extends outside a plane of the planar region. In some embodiments, a length dimension of the first portion is at least two times greater than a width dimension of the first portion. The former may further include a second portion extending from the first portion in a direction perpendicular to the plane of the first portion, the second portion may be integrally formed with the first portion and dimensioned to support a voice coil thereon. In some cases, the first portion may be operable to vibrate and output sound in response to an electrical audio signal input to a voice coil positioned around the second portion. In addition, the planar region may be entirely within a same plane and surround the out-of plane region, and the planar region may be solid. In some embodiments, the planar region may include at least one opening formed therethrough. The out-of-plane region may be a groove that runs parallel to the length dimension of the first portion, and the groove may extend from the plane of the first portion in a same direction as the second portion. In some embodiments, the out-of-plane region may be a first groove, the former may further include a second groove, and the first groove and the second groove extend from the plane of the first portion in an opposite direction as the second portion. In addition, the former may include a plurality of out-of-plane regions, and the plurality of out-of-plane regions have a length dimension that is parallel to the width dimension of the first portion. The former may further include a plurality of out-of-plane regions, and the plurality of out-of-plane regions may have a same size and shape. The first portion may include four sides, and the second portion extends from only two of the four sides. The former may further include a gusset between the first portion and the second portion, and the gusset may be dimensioned to geometrically stiffen the former. In addition, in some embodiments, a stiffening plate may be positioned on the first portion. 
     In other embodiments, the invention is directed to a high aspect ratio voice coil assembly including a former having a sound radiating portion and a sidewall extending perpendicular to a plane of the sound radiating portion for positioning of a voice coil thereon and a stiffening member integrally formed with the former to improve a stability of a high aspect ratio voice coil positioned thereon. In some embodiments, the voice coil may have an aspect ratio of at least 3.0. In some embodiments, an angle formed between the sound radiating portion and the sidewall is ninety degrees or less. The sound radiating portion may include a planar region that is entirely within the plane of the sound radiating portion, and the stiffening member comprises an out-of-plane region that protrudes outside the plane of the planar region and is surrounded by the planar region. The stiffening member may include a hem formed at an end of the sidewall, and the hem may be dimensioned to geometrically stiffen the former. In some cases, the stiffening member may include a plurality of indentations formed within adjoining portions of the sound radiating portion and the sidewall. In some embodiments, the sidewall may include at least one opening that extends through the sidewall. In addition, a material of the sound radiating portion, the sidewall and the stiffening member may be aluminum, titanium, stainless steel or carbon fiber. The high aspect ratio voice coil assembly may further include a frame, a magnet assembly coupled to the frame, wherein the former is suspended from the frame by a suspension member and positioned over the magnet assembly, and the voice coil is positioned around the sidewall of the former. 
     The above summary does not include an exhaustive list of all aspects of the present invention. It is contemplated that the invention includes all systems and methods that can be practiced from all suitable combinations of the various aspects summarized above, as well as those disclosed in the Detailed Description below and particularly pointed out in the claims filed with the application. Such combinations have particular advantages not specifically recited in the above summary. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The embodiments are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and they mean at least one. 
         FIG. 1  illustrates a cross-sectional side view of one embodiment of a transducer assembly. 
         FIG. 2  illustrates a perspective view of one embodiment of a voice coil former used in the transducer assembly of  FIG. 1 . 
         FIG. 3  illustrates a cross-sectional side view of the voice coil former of  FIG. 2  along line  3 - 3 ′. 
         FIG. 4  illustrates a top plan view the voice coil former of  FIG. 2 . 
         FIG. 5  illustrates a perspective view of another embodiment of a voice coil former implemented in the transducer assembly of  FIG. 1 . 
         FIG. 6  illustrates a cross-sectional side view of the voice coil former of  FIG. 5  along line  6 - 6 ′. 
         FIG. 7  illustrates a top plan view the voice coil former of  FIG. 5 . 
         FIG. 8  illustrates a side view of one embodiment of a voice coil former assembly used in the transducer assembly of  FIG. 1 . 
         FIG. 9  illustrates one embodiment of a simplified schematic view of embodiments of electronic devices in which the transducer assembly of  FIG. 1  may be implemented. 
         FIG. 10  illustrates a block diagram of one embodiment of an electronic device within which the transducer assembly of  FIG. 1  may be implemented. 
     
    
    
     DETAILED DESCRIPTION 
     In this section we shall explain several preferred embodiments of this invention with reference to the appended drawings. Whenever the shapes, relative positions and other aspects of the parts described in the embodiments are not clearly defined, the scope of the invention is not limited only to the parts shown, which are meant merely for the purpose of illustration. Also, while numerous details are set forth, it is understood that some embodiments of the invention may be practiced without these details. In other instances, well-known structures and techniques have not been shown in detail so as not to obscure the understanding of this description. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Spatially relative terms, such as “beneath”, “below”, “lower”, “above”, “upper”, and the like may be used herein for ease of description to describe one element&#39;s or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the exemplary term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising” specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. 
     The terms “or” and “and/or” as used herein are to be interpreted as inclusive or meaning any one or any combination. Therefore, “A, B or C” or “A, B and/or C” mean “any of the following: A; B; C; A and B; A and C; B and C; A, B and C.” An exception to this definition will occur only when a combination of elements, functions, steps or acts are in some way inherently mutually exclusive. 
       FIG. 1  illustrates a cross-sectional side view of one embodiment of a transducer assembly. Transducer assembly  100  may be any type of transducer that converts a signal in one form of energy to another form. For example, transducer assembly  100  may be an electroacoustic transducer having a sound radiating member or diaphragm and circuitry configured to produce a sound in response to an electrical audio signal input. For example, transducer assembly  100  may be a loudspeaker or micro-speaker that outputs audible sound to a user. In other embodiments, transducer assembly  100  may be a transducer that converts sound into an electrical signal, such as, for example, a microphone. In some embodiments, transducer assembly  100  is considered a high aspect ratio transducer in that transducer (and its associated components) has a length that is greater than its width, for example, a length that is at least two times, or at least three times, greater than its width. For example, transducer assembly  100  may have a high aspect ratio of 2.0, or in some embodiments, a high aspect ratio of 3.0. In this aspect, the various components of transducer assembly  100  may further include any number of stiffening or reinforcement members to improve stability (e.g., prevent bowing of the associated high aspect ratio voice coil) and/or high bending stiffness, which allows the transducer to reach high frequencies before partial vibration (breakup modes) occur. 
     Representatively, in one embodiment, to improve stability and/or achieve high bending stiffness, transducer assembly  100  may include a single piece former  102  having an inverted, substantially U shaped (with substantially flat top) channel structure. More specifically, former  102  may include a first portion  104  and a second portion  106  that form the channel, and may be suspended from a frame  108 , and over magnet assembly  124  within frame  108 , by suspension member  136 . Former  102  is considered a single piece in that the first portion  104  and the second portion  106  are inseparable portions of a one-piece, integrally formed structure. For example, first portion  104  and second portion  106  may be manufactured from a sheet of material that is, for example, stamped or pressed, to form portions of the sheet into the shape of first portion  104  and second portion  106 . 
     First portion  104  may, in some embodiments, be a horizontally extending member that can vibrate and produce sound in response to an electrical audio signal input. For example, first portion  104  may be a sound radiating portion or speaker diaphragm, as this term is commonly used in the context of speakers. In other embodiments, where transducer assembly  100  is, for example, a microphone, first portion  104  may be a sound pick-up surface that vibrates in response to a sound input and produces an electrical audio signal output. In this aspect, first portion  104  may include a substantially flat or planar region  110  that can vibrate or otherwise move in an axial direction  114  (along axis  112 ) to generate a sound output, or receive a sound input. Planar region  110  may, in some embodiments, be entirely within a single plane, as will be described in more detail in reference to  FIG. 2 . 
     In addition, to, for example, improve stability, first portion  104  may further include an out-of-plane region  116 , which protrudes outside the plane of planar region  110 . For example, out-of-plane region  116  may extend above or below the plane or planar region  110 . The out-of-plane region  116  may be dimensioned to geometrically stiffen portions of the former  102  (e.g., first portion  104  or second portion  106 ) and/or a voice coil  122  wrapped around former  102 . The out-of-plane region  116  may be formed by a single out-of-plane structure, or a number of out-of-plane structures formed within first portion  104 . The specific dimensions and configuration of out-of-plane region  116  will be described in more detail in reference to  FIGS. 2-7 . 
     Second portion  106  may extend from first portion  104  in a direction outside the plane of first portion  104  and support a voice coil  122 . For example, second portion  106  may be, or otherwise include, a wall or surface that extends from first portion  104  in a direction parallel to axis  112 . In this aspect, in some embodiments, an interior angle  118  formed between the interior surfaces of first portion  104  (or the plane of first portion) and second portion  106  may be ninety degrees or less. Second portion  106  may be considered as being below first portion  104  and, in some embodiments, confined to an area that is within a footprint of first portion  104 . In addition, although not shown, voice coil  122 , which is wrapped around second portion  106 , may have electrical connections to a pair of terminals through which an audio signal is received (or output), in response to which voice coil  122  produces a changing magnetic field that interacts with the magnetic field produced by magnet assembly  124  for driving transducer assembly  100 . In addition, it should be understood that because second portion  106  is integrally formed with first portion  104 , it eliminates the need to glue two separate pieces together (e.g., a bobbin to a diaphragm). This, in turn, provides the advantage of a more efficient way to couple the coil force to the air and leads to a smoother acoustic output to a higher frequency. In some embodiments, second portion  106  may further include stiffening or reinforcement members to improve a stability of transducer assembly  100 , for example, to prevent bowing of the associated high aspect ratio voice coil  122 . Representatively, second portion  106  may include a hem  120  formed by the end of second portion  106  opposite first portion  104 . The specific dimensions and configuration of the hem  120  will be described in more detail in reference to  FIGS. 2-7 . 
     In addition, it should be understood that in some embodiments where former  102  is made of a thermally conductive material, it may also serve as a heat sink for the voice coil  122 . For example, former  102  may be stamped from a single piece of a thermally conductive material such as aluminum. The aluminum within second portion  106  will, in turn, transfer the heat generated by the surrounding voice coil  122  to first portion  104 , where it is then dissipated away from first portion  104  as first portion  104  vibrates. It should be understood, however, that aluminum is just one exemplary material that could be used to form former  102 , and that other materials such as titanium, stainless steel, an aluminum alloy or a magnesium alloy, carbon fiber, or the like, are also contemplated. In addition, in some embodiments, former  102  may be formed from a sheet of material with an overall thickness of 100 microns or less, for example, from about 10 microns to about 50 microns, or 30 microns. 
     The entire former  102  may be suspended within frame  108  by suspension member  136 . Suspension member  136  may be a compliant member that allows for the substantially vertical movement of former  102  (e.g., along arrows  114 ). Suspension member  136  may, in one embodiment, have one side that is directly attached to an exterior surface, or top side, of planar region  110  and another side that is attached to frame  108 . Suspension member  136  may be attached to an entire perimeter area of planar region  110 , or only a portion of planar region  110  (e.g., only the long dimension or only the short dimension). Suspension member  136  may be formed by any suitably compliant material capable of suspending former  102  (e.g. polyether ether ketone (PEEK)). 
     Transducer assembly  100  may further include a magnet assembly  124  mounted to frame  108 . In this embodiment, magnet assembly  124  includes a permanent magnet  126  sandwiched by a ferromagnetic top plate  128  and a bottom plate  130 . Magnet assembly  124  further includes an air gap  132  through which a magnetic flux is directed. The former  102  with voice coil  122  attached thereto is in turn positioned within air gap  132 . In addition, in some embodiments, top plate  128  may optionally include a recessed region  138 . Recessed region  138  may be aligned with out-of-plane region  116  and provide more space between first portion  104  and magnet assembly  124  for vibration of first portion  104 . For example, in some embodiments, recessed region  138  may have a similar profile to that of out-of-plane region  116  (e.g., curved or concave shape). Still further, it is contemplated that in some embodiments, an optional opening may be formed through the portion of magnet assembly  124  below first portion  104 . The opening may further accommodate excursion of first portion  104  (e.g., allow first portion  104  to move up and down without contacting the surface), while also serving as a means for acoustic venting. 
       FIG. 2  illustrates a perspective view of one embodiment of a voice coil former used in the transducer assembly of  FIG. 1 . From this view, it can be seen that in one embodiment, former  102  has a substantially high aspect ratio, for example, an overall length that is at least two times, or at least three times that of its width. In addition, planar region  110  of first portion  104  may be entirely within a same plane  202 , while out-of-plane region  116  extends outside of plane  202  (and from planar region  110 ), for example, below plane  202 . It is contemplated, however, that while in this embodiment, out-of-plane region  116  is shown extending below plane  202  (or in a same direction as second portion  106 ), in other embodiments, out-of-plane region  116  may extend above plane  202  (or in a direction opposite second portion  106 ). In addition, planar region  110  may surround, form, or occupy, the entire region between out-of-plane region  116  and second portion  106 , such that the area between out-of-plane region  116  and second portion  106  is planar or flat. Moreover, from this view, it can be seen that out-of-plane region  116  extends along the entire length of former  102 . Representatively, out-of-plane region  116  may be a longitudinal groove or channel which is stamped from a material of former  102  such that a recessed region is formed in the top side of first portion  104  and it is one integrally formed, and continuous piece, with planar region  110 . In some embodiments, out-of-plane region  116  may be more of a solid protruding member such as a rib-like structure that extends below (or above) plane  202 , but does not have a corresponding recessed (or hollow) region along the opposite side. Other shapes, sizes and/or configurations, however, are also contemplated. 
     Second portion  106  may include two separate arms or sidewalls  106 A,  106 B that are parallel to each other and extend outside of plane  202 . For example, second portion  106  may include sidewalls  106 A,  106 B that extend from first portion  104  (or plane  202 ) in a downward or vertical direction, that is parallel to axis  112  (shown in  FIG. 1 ). In other words, sidewalls  106 A,  106 B extend in a same direction as out-of-plane region  116 . In some embodiments, first portion  104  may be considered as having four sides, for example, two length sides  208  and two width sides  210 , and sidewalls  106 A,  106 B may extend along only the length sides  208  of former  102 . In this aspect, the width sides  210  (or ends) of former  102 , and the inverted U shaped (with substantially flat top) channel formed by former  102 , are considered open. Sidewalls  106 A,  106 B may be integrally formed with first portion  104  (as by bending the edges of a single sheet of material) such that former  102  is one continuous, unibody structure. 
     Former  102  may further include openings  204 ,  206  formed through first portion  104  and second portion  106 . Openings  204 ,  206  may have any size, shape and pattern (e.g., round, elongated, square, or the like) suitable for reducing a mass of former  102 . In some embodiments, openings  204 ,  206  may be dimensioned or positioned to allow for ventilation of heat, or adjustment of the acoustic resistance. For example, a hole pattern could be selected with relatively fewer large-size holes for the purpose of mass reduction, or alternatively or in combination, a higher number of smaller-sized holes may be positioned to provide a tailored amount of acoustic resistance via viscous loss of airflow pumping through small orifices. Openings  204 ,  206  may be formed entirely through one, or both, of the walls forming first portion  104  and second portion  106 . It is further contemplated that while a number of openings  204 ,  206  are shown, in some embodiments, only one of openings  204  and/or  206  may be presented. In addition, in embodiments, where openings  204  are formed through first portion  104  as shown, a separate stiffening member, or other solid plate-like structure, may be placed over first portion  104  to cover the openings  204  so that first portion  104  may be used as a sound pick-up or sound radiating surface. An embodiment including a stiffening member will be discussed in more detail in reference to  FIG. 8 . 
       FIG. 3  illustrates a cross-sectional side view of the voice coil former of  FIG. 2  along line  3 - 3 ′. From this view, it can be seen that sidewalls  106 A,  106 B of second portion  106  are vertically oriented (e.g., parallel to axis  112 ) with respect to first portion  104  such that they form an outer surface that may be considered perpendicular to the planar region  110  of first portion  104 . In this aspect, angle  118  formed between sidewalls  106 A,  106 B can be understood to be 90 degrees. It is contemplated, however, that in some embodiments, sidewalls  106 A,  106 B of second portion  106  and/or planar region  110  of first portion  104  may be oriented such that angle  118  is less than 90 degrees. 
     In addition, sidewalls  106 A,  106 B may include hem  120 . Hem  120  may be of any size and shape sufficient to support a voice coil and/or provide further stiffness and/or stability to former  102 . Representatively, hem  120  may be a substantially flat structure that extends along the entire length of sidewalls  106 A,  106 B, in a substantially horizontal or lateral direction (e.g., perpendicular to axis  112 ). The hem may run only partially around the perimeter, forming discrete tabs providing coil support and some measure of extra stiffness. In this aspect, hem  120  may be considered to form a 90 degree angle with sidewalls  106 A,  106 B. In other embodiments, however, hem  120  may have other configurations. For example, hem  120  may curved, or otherwise bent, in an upward direction such that it is substantially parallel to sidewalls  106 A,  106 B. In this aspect, hem  120  may be flattened against the outer surface of sidewalls  106 A,  106 B, or a gap may be formed between the outer surface of sidewalls  106 A,  106 B and hem  120 . In other embodiments, hem  120  may form a tear drop like shape, or an inverted question mark like shape along the bottom of sidewalls  106 A,  106 B. Regardless of the particular geometry of hem  120 , it can be formed form a same material as the former sidewalls  106 A,  106 B, for example, by bending the bottom ends or portions of sidewalls  106 A,  106 B into the desired geometry. In addition, hem  120  may be shorter than sidewalls  106 A,  106 B such that it does not extend along an entire height of sidewalls  106 A,  106 B when it is in the vertical, teardrop or question mark shape, such that it does not cover the entire outer surface of sidewalls  106 A,  106 B. 
     Referring now to out-of-plane region  116  in more detail, from this view, it can be seen that out-of-plane region  116  has a relatively narrow, curved shape, which is confined to a middle region of first portion  104 . In other words, it does not extend the entire width of first portion  104  such that the entire first portion  104  is curved. Rather, the area around out-of-plane region  116 , or between out-of-plane region  116  and second portion  106 , is the planar region  110 , which is entirely flat and within plane  202 . In other embodiments, out-of-plane region  116  may have other shapes (e.g. v shaped, flat bottom, etc.). In addition, in some embodiments, the out-of-plane region  116  may be stamped from the same material as the rest of first portion  104  such that a recessed region  302  is formed along the top side of first portion  104 . In other words, the top side of first portion  104  is also outside (e.g., below) plane  202 , and may be considered open or hollow. In this aspect, the out-of-plane region  116  may be referred to as forming a channel or groove along first portion  104 . In some cases, the out-of-plane region  116  may be a relatively solid member, for example a rib, which extends below plane  202  along one side but does not form a recessed region  302 , but rather the entire top side of first portion  104  remains solid or flat, and within plane  202 . For example, in this embodiment, out-of-plane region  116  may be formed by a thickened region of the material used to form first portion  104 . 
     The specific dimensions of first portion  104  of former  102  will now be discussed in more detail in reference to  FIG. 4 . Representatively,  FIG. 4  illustrates a top plan view of former  102  of  FIG. 2 . From this view, it can be seen that first portion  104  includes a length dimension (L) that is greater than its width dimension (W). For example, in this embodiment, first portion  104  may have a substantially rectangular shape with two length sides  208  and two width sides  210 . First portion  104  (and in turn former  102 ) may be considered to have a high aspect ratio in that the length sides  208  may be two times, three times, or more, greater than the width sides  210 . In other embodiments, first portion  104  may have other shapes having a length dimension (L) that is at least two or three times greater than the width dimension (W), in other words having a high aspect ratio. For example, first portion  104  may have an elliptical or racetrack like shape, in which the length dimension is significantly greater than the width dimension. It can further be seen from this view that out-of-plane region  116  is a longitudinally extending member that is parallel to the length dimension (L), and extends the entire length. In addition, planar region  110  occupies the entire area between out-of-plane region  116  and the length sides  208  of first portion  104 . In other words, the entire area of former  102  surrounding out-of-plane region  116  is planar or flat. 
       FIG. 5  illustrates a perspective view of another embodiment of a voice coil former implemented in the transducer assembly of  FIG. 1 . Former  502  is a high aspect ratio former similar to former  102 , except that in this embodiment, former  502  includes a number of out-of-plane regions  516  for added stiffness, and additional stiffening or reinforcement members  512 . In particular, similar to former  102 , former  502  includes a horizontal first portion  504  and a vertical second portion  506 , that extends from, and is integrally formed with, first portion  504 , as previously discussed. Second portion  506  may further include a hem  520  including any of the previously discussed configurations. Former  502 , however, further includes a number of out-of-plane regions  516  formed between the planar region  510  of first portion  104 . In addition, in this embodiment, out-of-plane regions  516  are elongated structures that, instead of extending parallel to the length dimension of the former, extend parallel to the width dimension of former  502 . In other embodiments, out-of-plane regions  516  may have any size and shape sufficient to provide additional stiffness and/or stability to former  502 . For example, out-of-plane regions  516  may have a concave, cone, pyramid, square or the like profile and/or shape. The specific dimensions of out-of-plane regions  516  will be described in more detail in reference to  FIG. 6  and  FIG. 7 . 
     In addition, a number of stiffening or reinforcement members  512  may be formed within the adjoining regions between first portion  504  and second portion  506 , referred to as corners or edges  522 . Representatively, reinforcement members  512  may be formed within the corners or edges  522  of former  502 , between each of out-of-plane regions  516 . Reinforcement members  512  may be indentations, gussets or the like which are integrally formed within the portions of first portion  504  and second portion  506  then adjoin to form the edges  522  of former  502 . For example, in some embodiments, reinforcement members  512  may be triangular, cone or pyramid like, shaped regions that are stamped into corners or edges  522  and protrude into the interior region of former  502 . In some embodiments, reinforcement members  512  may be formed as one continuous piece within the corners or edges  522  of former  502  such that no openings are formed through the corners or edges  522  of former  502 , while in other embodiments there may be openings formed around, or within, reinforcement members  512 . Reinforcement members  512  may be formed, for example, by stamping indentations into the corner regions of former  502  as shown, such that they are integrally formed parts of former  502 . In other embodiments, reinforcement members  512  could be solid members, or be separate pieces, which are attached to corners or edges  522 . In addition, while reinforcement members  512  are shown formed between each of out-of-plane region  516 , any number of reinforcement member  512 , and in any configuration, suitable to stiffen former  502 , may be used. 
     Still further, in this embodiment, second portion  506  may extend from all four sides of first portion  504 . Representatively, second portion  506  may include sidewalls  506 A,  506 B (see sidewall  506 B shown in  FIG. 7 ) which extend from the length sides  524  of first portion  504  and sidewalls  506 C,  506 D extending from the width sides  526  of first portion  504 . In some embodiments, sidewalls  506 A,  506 B and sidewalls  506 C,  506 D are not connected at their ends such that gaps are formed between each of the sidewalls as shown. In other words, sidewalls  506 A- 506 D do not extend from an entire perimeter of first portion  504 . In other embodiments, sidewalls  506 A- 506 D may form one continuous sidewall along an entire perimeter of first portion  504 . Openings  508  may further be formed in one or more of sidewalls  506 A- 506 D and/or first portion  504 . For example, in the illustrated embodiment, openings  508  are only formed in sidewalls  506 A and  506 B, and first portion  504  is solid. 
     Referring in more detail now to out-of-plane regions  516 ,  FIG. 6  illustrates a cross-sectional side view of the voice coil former of  FIG. 5  along line  6 - 6 ′, which is through one of the out-of-plane regions  516 . From this view, it can be seen that in this embodiment, out-of-plane regions  516  extend above a plane  602  of the planar region  510  of first portion  504 . In other words, out-of-plane regions  516  extend from plane  602  in a direction opposite that of second portion  506 . It is contemplated, however, that in other embodiments, out-of-plane regions  516  may extend below plane  602 , or some may extend above and some may extend below plane  602 . In addition, a corresponding recessed region  604  is formed along the outer surface of first portion  504 , such that the outer surface of first portion  504  also extends below the plane  602  of planar region  510 . In other words, out-of-plane region  516  is a groove or channel shaped structure that is, for example, stamped out of the material used to form first portion  504 . In other embodiments, out-of-plane region  516  may be more of a rib shaped structure that is substantially solid and does not include the corresponding recessed region  604 . Out-of-plane region  516  may have any cross-sectional shape suitable for adding stiffness to former  502 . For example, in this embodiment, out-of-plane region  516  is shown having a substantially flat top surface, which is parallel to plane  602 . Other shapes and sizes, however, are possible. 
     In addition, reinforcement members  512  are shown formed within corners or edges  522 , which are formed by adjoining portions of first portion  504  and second portion  506 , along both sides of former  502 . Reinforcement members  512  may further protrude into the interior area of former  502 . It is contemplated, however, that in other embodiments, reinforcement members  512  may be outwardly protruding members, or may be separate structures attached to the corners  522 . 
       FIG. 7  illustrates a top plan view the voice coil former of  FIG. 5 . From this view, it can be seen that first portion  504  includes a length dimension (L) that is greater than its width dimension (W). For example, in this embodiment, first portion  504  may have a substantially rectangular shape with two length sides  524  and two width sides  526 . First portion  504  (and in turn former  502 ) may be considered to have a high aspect ratio in that the length sides  524  may be two times, three times, or more, greater than the width sides  526 . In other embodiments, first portion  504  may have other shapes having a length dimension (L) that is at least two or three times greater than the width dimension (W), in other words having a high aspect ratio. For example, first portion  504  may have an elliptical or racetrack like shape, in which the length dimension is significantly greater than the width dimension. It can further be seen from this view that out-of-plane region  516  includes a number of laterally extending structures that are parallel to the width dimension (W), and are spaced from one another along the length dimension (L) of first portion  504 . In addition, the entire area between each of out-of-plane regions  516  is made up of planar region  510 . In other words, planar region  510  entirely surrounds out-of-plane regions  516 . Although five out-of-plane regions  516  are shown, it is contemplated, that any number of out-of-plane regions suitable for stiffening former  502  may be used, with spacing between each region. 
       FIG. 8  illustrates a side view of one embodiment of a voice coil former assembly used in the transducer assembly of  FIG. 1 . Representatively, voice coil former assembly  800  may include former  102 , which includes first portion  104  and second portion  106 , and voice coil  122  wrapped around second portion  106 , as previously discussed in reference to  FIG. 1  to  FIG. 4 . In addition, in this embodiment, voice coil former assembly  800  may further include stiffening member  804 . Representatively, stiffening member  804  may be a membrane or plate like structure which is positioned along a top surface of first portion  104  to provide further stiffness and facilitate sound radiation or sound pick-up by first portion  104 . For example, when first portion  104  includes openings, it may not be able to operate as a sound pick-up or sound radiating surface (e.g., a speaker diaphragm). It is therefore necessary to provide a substantially solid stiffening member  804  over first portion  104  to plug the openings and provide further stiffness to first portion  104 . Stiffening member  804  may be made of a same material as first portion  104 , or a different material (e.g., polyether ether ketone). Stiffening member  804  may be attached to first portion  104  by any suitable technique (e.g., chemical or mechanical bonding). 
     In addition, voice coil former assembly  800  is shown including a secondary suspension member  802  to provide additional stability. In particular, since former  102  has a high aspect ratio as previously discussed, it may be prone to “rocking” (tipping or rotating motion) along the length dimension (L), (W) dimension, or an intermediate angle and, in turn, move in a fashion which does not contribute to the useful acoustic output and increases the risk of undesirable contact between the moving and stationary components. This detrimental behavior can limit the usable maximum excursion of the transducer. Secondary suspension member  802  may therefore be positioned along each of the width ends of former  102  and attached to the frame  108  to provide further stability along these ends and prevent (or reduce) rocking. For example, there may be two separate secondary suspension members  802  positioned along each end of former  102 . Secondary suspension member  802  may be within a different plane than suspension member  136  (see  FIG. 1 ), for example, a plane of voice coil  122 , which is below suspension member  136 . In some embodiments, secondary suspension member  802  may include a top suspension member  802 A and a bottom suspension member  802 B. Each of top and bottom suspension members  802 A,  802 B may bow out in opposite directions with respect to one another, and may expand/contract toward and/or away from each other depending upon a motion of voice coil former assembly  800  (e.g., similar to a 4-bar linkage). In one embodiment, secondary suspension member  802  is attached directly to voice coil  122  by any suitable technique (e.g. chemical or mechanical bonding). In other embodiments, member  802  may be attached to another portion of voice coil former assembly  800 , for example, a portion of former  102 . Secondary suspension member  802  may be made of a same or different material as suspension member  136 . 
       FIG. 9  illustrates one embodiment of a simplified schematic view of embodiments of electronic devices in which a speaker assembly, such as that described herein, may be implemented. As seen in  FIG. 9 , the speaker may be integrated within a consumer electronic device  902  such as a smart phone with which a user can conduct a call with a far-end user of a communications device  904  over a wireless communications network; in another example, the speaker may be integrated within the housing of a portable timepiece  906 . These are just two examples of where the transducer described herein may be used, it is contemplated, however, that the speaker may be used with any type of electronic device in which a speaker is desired, for example, a tablet computer, a computing device or other display device. 
       FIG. 10  illustrates a block diagram of one embodiment of an electronic device within which the previously discussed speaker may be implemented. As shown in  FIG. 10 , device  1000  may include storage  1002 . Storage  1002  may include one or more different types of storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory), volatile memory (e.g., battery-based static or dynamic random-access-memory), etc. 
     Processing circuitry  1004  may be used to control the operation of device  1000 . Processing circuitry  1004  may be based on a processor such as a microprocessor and other suitable integrated circuits. With one suitable arrangement, processing circuitry  1004  and storage  1002  are used to run software on device  1000 , such as internet browsing applications, voice-over-internet-protocol (VOIP) telephone call applications, email applications, media playback applications, operating system functions, etc. Processing circuitry  1004  and storage  1002  may be used in implementing suitable communications protocols. Communications protocols that may be implemented using processing circuitry  1004  and storage  1002  include internet protocols, wireless local area network protocols (e.g., IEEE 802.11 protocols—sometimes referred to as Wi-Fi®), protocols for other short-range wireless communications links such as the Bluetooth® protocol, protocols for handling 3G or 4G communications services (e.g., using wide band code division multiple access techniques), 2G cellular telephone communications protocols, etc. 
     To minimize power consumption, processing circuitry  1004  may include power management circuitry to implement power management functions. For example, processing circuitry  1004  may be used to adjust the gain settings of amplifiers (e.g., radio-frequency power amplifier circuitry) on device  1000 . Processing circuitry  1004  may also be used to adjust the power supply voltages that are provided to portions of the circuitry on device  1000 . For example, higher direct-current (DC) power supply voltages may be supplied to active circuits and lower DC power supply voltages may be supplied to circuits that are less active or that are inactive. If desired, processing circuitry  1004  may be used to implement a control scheme in which the power amplifier circuitry is adjusted to accommodate transmission power level requests received from a wireless network. 
     Input-output devices  1006  may be used to allow data to be supplied to device  1000  and to allow data to be provided from device  1000  to external devices. Display screens, microphone acoustic ports, speaker acoustic ports, and docking ports are examples of input-output devices  1006 . For example, input-output devices  1006  can include user input-output devices  1008  such as buttons, touch screens, joysticks, click wheels, scrolling wheels, touch pads, key pads, keyboards, microphones, cameras, etc. A user can control the operation of device  1000  by supplying commands through user input-output devices  1008 . Display and audio devices  1010  may include liquid-crystal display (LCD) screens or other screens, light-emitting diodes (LEDs), and other components that present visual information and status data. Display and audio devices  1010  may also include audio equipment such as speakers and other devices for creating sound. Display and audio devices  1010  may contain audio-video interface equipment such as jacks and other connectors for external headphones and monitors. 
     Wireless communications devices  1012  may include communications circuitry such as radio-frequency (RF) transceiver circuitry formed from one or more integrated circuits, power amplifier circuitry, passive RF components, antennas, and other circuitry for handling RF wireless signals. Wireless signals can also be sent using light (e.g., using infrared communications). Representatively, in the case of a speaker acoustic port as shown in  FIG. 9 , the speaker may be associated with the port and be in communication with an RF antenna for transmission of signals from the far end user to the speaker. 
     Returning to  FIG. 10 , device  1000  can communicate with external devices such as accessories  1014 , computing equipment  1016 , and wireless network  1018  as shown by paths  1020  and  1022 . Paths  1020  may include wired and wireless paths. Path  1022  may be a wireless path. Accessories  1014  may include headphones (e.g., a wireless cellular headset or audio headphones) and audio-video equipment (e.g., wireless speakers, a game controller, or other equipment that receives and plays audio and video content), a peripheral such as a wireless printer or camera, etc. 
     Computing equipment  1016  may be any suitable computer. With one suitable arrangement, computing equipment  1016  is a computer that has an associated wireless access point (router) or an internal or external wireless card that establishes a wireless connection with device  1000 . The computer may be a server (e.g., an internet server), a local area network computer with or without internet access, a user&#39;s own personal computer, a peer device (e.g., another portable electronic device), or any other suitable computing equipment. 
     Wireless network  1018  may include any suitable network equipment, such as cellular telephone base stations, cellular towers, wireless data networks, computers associated with wireless networks, etc. For example, wireless network  1018  may include network management equipment that monitors the wireless signal strength of the wireless handsets (cellular telephones, handheld computing devices, etc.) that are in communication with network  1018 . 
     While certain embodiments have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative of and not restrictive on the broad invention, and that the invention is not limited to the specific constructions and arrangements shown and described, since various other modifications may occur to those of ordinary skill in the art. For example, although a speaker is specifically disclosed herein, the unibody former and voice coil assembly disclosed herein could be used with other types of transducers, for example, microphones or other transducers (e.g., ambient pressure sensor). Still further, although a portable electronic device such as a mobile communications device is described herein, any of the previously discussed transducer configurations may be implemented within a tablet computer, personal computer, laptop computer, notebook computer and the like. The description is thus to be regarded as illustrative instead of limiting.

Metadata:
Filing Date: 20170616
Publication Date: 20200204
Grant Date: 20200204
Priority Date: 20170616
Inventors: SALVATTI, ALEXANDER V.
ILKORUR, ONUR I.
Assignee: APPLE INC
CPC Classifications: [{"code": "H04R9/06", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R7/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R9/06", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R9/06", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R9/045", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R7/20", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R9/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R7/125", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R9/06", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R7/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R7/125", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R9/045", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R7/20", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 64658588