Speaker with a coil stabilizer and method for manufacturing the same

A speaker and method for making the same are provided. The speaker includes a permanent magnet and a coil disposed about a first axis around the permanent magnet, the coil being configured to move along the first axis. The speaker further includes a membrane attached to a top surface of the coil and a stabilizer contacting at least one of an internal surface, an external surface, and a bottom surface of the coil, and configured to limit movement of the coil relative to a second axis perpendicular to the first axis.

BACKGROUND

a. Technical Field

This disclosure generally relates to a speaker and a method for manufacturing the same. In particular, the instant disclosure relates to a speaker with a coil stabilizer.

b. Background Art

This background description is set forth below for the purpose of providing context only. Therefore, any aspects of this background description, to the extent that it does not otherwise qualify as prior art, is neither expressly nor impliedly admitted as prior art against the instant disclosure.

Microspeakers (i.e., electroacoustic transducers) are loudspeakers used to reproduce sound in microelectronic equipment such as mobile phones, cellular phones, camcorders, mp3 players, navigation systems, PDAs, digital cameras, notebook computers, LCD TVs, DVD players, etc. Microspeakers are used when space is at a premium. In such applications, it is desired that the speaker (including the back volume) should be as compact as possible. However, it is also desired that the speaker should be able to output in the broadest range of frequencies possible. These are conflicting requirements.

The microspeaker may comprise a membrane attached to a voice coil, which may be positioned within a magnetic field defined by a permanent magnet and yoke or pot arrangement. Some applications require the coil to have a length greater than its width (for example, 3:1 or 2:1). It may also be desirable for the coil (disposed about an axis) to only move along that axis. As such, it may be undesirable for the coil to move in other directions along/about other axes. With a length-width proportion of 3:1, for example, the coil may be more inclined to move in such undesirable directions. Therefore, there is a need for a speaker and a method for manufacturing a speaker that will minimize and/or eliminate one or more of the above-identified deficiencies.

The foregoing discussion is intended only to illustrate the present field and should not be taken as a disavowal of claim scope.

SUMMARY

A speaker in accordance with one embodiment of the present teachings comprises a permanent magnet and a coil disposed about a first axis and around the permanent magnet. The coil is configured to move along the first axis. The speaker further includes a membrane coupled to a top surface of the coil and a stabilizer contacting at least one of an internal surface, an external surface, and a bottom surface of the coil, and configured to limit movement of the coil relative to a second axis perpendicular to the first axis.

A method for manufacturing a speaker in accordance with another embodiment of the present teachings comprises providing a permanent magnet. The method further comprises providing a coil with an internal surface, an external surface, a top surface, and a bottom surface. The method further includes attaching a stabilizer to at least one of the internal surface, external surface, and bottom surface of the coil. The method further includes coupling the top surface of the coil to a membrane. The method further includes assembling the speaker by suspending the membrane, such that the coil is disposed about a first axis and around the permanent magnet. The stabilizer is configured to limit movement of the coil relative to a second axis perpendicular to the first axis.

DETAILED DESCRIPTION

It will be appreciated that for conciseness and clarity, spatial terms such as “vertical,” “horizontal,” “up,” and “down” may be used herein with respect to the illustrated embodiments. However, speakers may be used in many orientations and positions, and these terms are not intended to be limiting or absolute.

Referring now to the drawings wherein like reference numerals are used to identify identical or similar components in the various views,FIGS. 1-4illustrate a speaker20in accordance with one embodiment of the present teachings. Speaker20may comprise a magnetic circuit for generating magnetic flux, a vibration system that vibrates due to repulsive force against the magnetic flux acting on the magnetic circuit, and a main body or frame22. With particular reference toFIGS. 3-4, the magnetic circuit may comprise a permanent magnet24, a pot26with magnet24disposed thereon, and an upper plate28attached to an upper surface30of magnet24. In the illustrated embodiment, magnet24comprises portion32and portion34adjacent to portion32with a gap36disposed therebetween. Upper plate28may be configured to assist in generation of the magnetic field. In the illustrated embodiment, upper plate28comprises portion37aand portion37bwith portion37abeing attached to portion32of magnet24and portion37bbeing attached to portion34of magnet24. In other embodiments, magnet24and upper plate28each comprises only one portion or more than two portions.

Referring particularly toFIG. 4, the vibration system may comprise a voice coil38, a membrane40, and a coil stabilizer42. Coil38may be configured to generate magnetic flux when an electric current is driven into coil38. In response to the electric current, coil38may be configured to move along an axis44. In an embodiment, coil38may be disposed about axis44and around magnet24in a gap46(FIG. 3) between magnet24and pot26. Pot26may define slots48,49through which stabilizer42may travel (with coil38). As shown inFIG. 3, coil38may comprise a top surface50to which membrane40may be coupled, a bottom surface52, an internal surface54, and an external surface56. The electrical connections to coil38are not shown; however, spring clips may be used to provide external connections to coil38. As shown inFIG. 4, membrane40may have a central region58and a torus60forming a supporting edge region, which may define the compliance of membrane40. In an embodiment, membrane40may be composed of an elastomer material, as described in U.S. Patent Publication No. 2012/0093353 A1, the entire disclosure of which is incorporated herein by reference as though set forth in its entirety.

Stabilizer42may be configured to stabilize coil38as coil38moves along axis44. In some embodiments, stabilizer42may limit movement of coil38in directions other than along axis44. For example and without limitation, stabilizer42may be configured to limit movement of coil38relative to an axis62and/or an axis64, which are each perpendicular to axis44and (together with axis44) define a three-dimensional coordinate system. Moreover, in some embodiments, stabilizer42may be configured to limit rotation of coil38about axis44, axis62, and/or axis64(i.e., yaw, pitch, and roll).

FIGS. 5-7illustrate the shape and function of stabilizer42relative to coil38. In the illustrated embodiment, stabilizer42extends through axis44from the center of a segment68of coil38to the center of a segment70of coil, segment70being diametrically opposed of (and generally parallel to) segment68relative to axis44. In other embodiments, stabilizer42extends from a segment72of coil38to a segment74of coil38, segment74being diametrically opposed of segment72relative to axis44. Although in the illustrated embodiment, stabilizer42extends through axis44at an angle76perpendicular to segments68,70, one of ordinary skill in the art will understand that stabilizer42may be disposed at various locations about coil38and may extend at various angles relative to segments68,70,72,74. Moreover, more than one stabilizer may be used for the same coil. For example and without limitation, one stabilizer may extend from segment68to segment70, and another stabilizer may extend from segment72to segment74(the two stabilizers intersecting one another). In such an embodiment, the two stabilizers may be coupled to one another. In the illustrated embodiment, coil38has a length77a(generally defined by segments68,70) and a width77b(generally defined by segments72,74), with width77bbeing approximately one third in magnitude of length77a(i.e., length-width proportion is 3:1). Although stabilizer42is illustrated as being coupled to segments68,70, which generally have length77a(the greater dimension in the illustrated embodiment), one of ordinary skill in the art will understand that stabilizer42can be adapted for coils having any length-width proportions (for example and without limitation, 1:1 or 2:1) and may be coupled to segments having the lesser dimension of length and width.

Referring particularly toFIG. 7, stabilizer42may comprise ends78,80with slots82,84. Slots82,84may be defined at least partially by walls86,88,90,92and a base94connecting walls86,88,90,92. In the illustrated embodiment, ends78,80are generally U-shaped such that walls88,90each extend along internal surface54, walls86,92each extend along external surface56, and base94extends along bottom surface52of coil38with slots82,84each having an opening96,98. Walls86,88,90,92may extend along a majority of a height99(FIG. 5) of the coil38. As shown inFIG. 5, segments68,70of coil38may extend through slots82,84, respectively, such that coil38is releasably secured inside slots82,84. In the illustrated embodiment, wall86abuts external surface56of segment68of coil38; wall88abuts internal surface54of segment68; wall90abuts internal surface65of segment70; and wall92abuts external surface56of segment70. As illustrated inFIG. 7, in one embodiment, widths100,102of slots82,84are approximately equal to a width104(FIG. 2) of coil38. With such a configuration, opposing compressive forces from stabilizer42onto coil38(and their respective reaction forces) aid in retaining coil38within stabilizer42. Furthermore, slots82,84may be widened proximate to bottom surface52of coil38to provide a sufficient area for housing an adhesive used to secure coil38to stabilizer42. Stabilizer42may be coupled to coil38via the use of these compressive forces and/or through adhesives. Additionally, in the illustrated embodiment, to assist with assembly and to avoid damage to coil38, slots82,84are generally chamfered at openings96,98, and base94of stabilizer42is generally V-shaped at ends78,80. Although in the illustrated embodiment, stabilizer42is attached and/or coupled to internal surface54, external surface56, and bottom surface52of coil38(or at least to portions thereof) with ends78,80being generally U-shaped, one of ordinary skill in the art will understand that stabilizer42may be attached to and/or be configured to contact only one or two of such surfaces. For example, and without limitation, stabilizer42may be attached to only bottom surface52of coil38and not extend along internal surface54and external surface56of coil38. Furthermore, one of ordinary skill in the art will understand that slots82,84can take on any shape besides that which is illustrated in the Figures.

Referring toFIG. 6, stabilizer42may further comprise an intermediate section106disposed between ends78,80. In the illustrated embodiment, intermediate section106contains two apertures108,110which reduce the overall weight of stabilizer42. In other embodiments, intermediate section106has less than or more than two apertures (seeFIGS. 8-10for an embodiment with three apertures). Apertures108,110can be of any size. In yet a further embodiment, intermediate section106contains no apertures and serves as a bridge connecting ends78,80, which may result in an even lesser overall weight of stabilizer42. Intermediate section106may comprise a top surface112that is generally convex such that top surface112aids in supporting central region58of membrane40(FIGS. 3-4). In other embodiments (such as the embodiment illustrated inFIGS. 8-10), top surface112may be flat and may or may not support membrane40.

Although stabilizer42is shown as being disposed along a majority of internal surface54and external surface56of coil38, stabilizer42may be disposed only internally or only externally of coil38. For example and without limitation, stabilizer42can be constructed with no intermediate section106and/or “float” about coil38. In one embodiment, stabilizer42may be in the form of a sleeve that circumferentially surrounds at least a portion of external surface56of coil38. Furthermore, although stabilizer42is illustrated as being coupled to coil38, stabilizer42may instead be stationary and disposed near coil38(for example and without limitation, acting as a guide). In such an embodiment, stabilizer42may only contact coil38if coil38moves in an undesirable direction (i.e., in a direction other than along axis44) to maintain movement of coil38along axis44. In such an embodiment, at least a portion of stabilizer42may be attached to frame22, pot26, and/or upper plate28of magnet24. In another embodiment, stabilizer42may be in the form of one or more support members disposed along frame22, pot26and/or upper plate28and protruding therefrom to contact at least one of internal surface54, external surface56, and bottom surface52of coil38as coil38moves along axis44. In yet another embodiment, stabilizer42is not coupled to coil38but, instead, is coupled to membrane40and, thus, moves with membrane40(and coil38would float within slots82,84of stabilizer42). In yet a further embodiment, stabilizer42may contact top surface50of coil38and be at least partially disposed between top surface50of coil38and membrane40with stabilizer42being coupled to membrane40. In such a configuration, U-shaped ends78,80of stabilizer42may be inverted such that openings96,98are proximate to bottom surface52of coil38.

In yet another embodiment, stabilizer42may consist of several portions coupled to coil38at various locations around coil38, with one or more portions coupled to one another via bridges disposed along internal surface54and/or external surface56of coil38. With such a configuration, each portion (disposed at different locations around coil38) are interconnected with some or all of the other portions and, together, serve as support for coil38.

Although the instant disclosure discusses ends78,80of stabilizer42being generally U-shaped, one of ordinary skill in the art will appreciate that ends78,80do not have to be U-shaped, but instead could extend along one of internal surface54and external surface56of coil38. Furthermore, stabilizer42may consist of one or more bridges that extend within coil38and are coupled at least to internal surface54of coil38.

FIGS. 8-10illustrate another embodiment of the present teachings and include various views of a stabilizer42′. Stabilizer42′ may be similar to the stabilizer42illustrated inFIGS. 1-7, except that stabilizer42′ comprises three apertures114′,116′,118′ in intermediate section106′ with top surface112′ of intermediate section106′ being flat.

The foregoing numerous embodiment solve one or more problems known in the art.

Any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated materials does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference.

While one or more particular embodiments have been shown and described, it will be understood by those of skill in the art that various changes and modifications can be made without departing from the spirit and scope of the present teachings.