Patent Application
20200374633
An aspect of the invention is directed to flat transducer for surface actuation, more specifically, a flat transducer having a suspension system incorporated within the magnet assembly to reduce an overall thickness. Other aspects are also described and claimed.
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 speakers that can benefit from improved audio performance. Smart phones, however, do not have sufficient space to house transducers, or other actuators, having a relatively large z-height or thickness. This is also true for some portable personal computers such as laptop, notebook, and tablet computers, and, to a lesser extent, desktop personal computers with built-in transducers. Such size constraints, however, can pose a challenge since the transducers or actuators incorporated within these devices may include a moving coil motor made up of a stack-up of various components. For example, the moving coil motor may include a diaphragm, voice coil and magnet assembly positioned within a frame, all of which add to the overall z-height of the assembly.
An aspect of the disclosure is directed to a thin transducer that serves as an actuator for the surface to which it is connected to. Such a transducer may also be referred to herein as an electro-dynamic transducer or a shaker. A shaker (or surface actuator) may be used to actuate (e.g., vibrates) a surface it is connected to and use the structure as its radiating surface. Shakers may depend on the inertia of the magnet motor system for their performance. The higher the inertia and the force, which is generated by the magnet motor, the more effective they become in application. Given different working orientations, heavy magnet mass, however, develops a static load over the suspension due to gravity or acceleration of the device and may force the suspension to bend in an axis other than parallel to the symmetry axis of the transducer. Any suspension should constrain the movement of the magnet motor, only in the symmetry axis direction, and should not allow relative motion to occur between any of two points over the magnet. To accomplish this, a suspension having a high stiffness to prevent the magnet motor from moving in directions other than parallel to the symmetry axis may be used. Such suspensions, however, are positioned in the excursion space between the moving mass (e.g., magnet) and the actuating surface, which can increase non-linear behavior of the suspension since it must collapse completely to allow maximum excursion. In addition, rigid suspension members result in high resonance frequencies for a given mass, which can adversely affect the performance of the assembly.
The transducer assembly disclosed herein solves some of the previously discussed challenges by incorporating the suspension assembly inside the magnet assembly stack-up, and in such a way that it does not increase the z-height of the overall assembly. For example, the suspension assembly may include a number of suspension elements or members, such as springs (e.g., leaf springs) arranged around the perimeter of the magnet assembly, as opposed to extending from a top or bottom side of the magnet assembly, so that they do not add to the z-height. In addition to a reduced z-height, rocking mode prevention may be achieved by adding suspension elements (e.g., leaf springs) to a center opening of the magnet assembly. The suspension elements in the center opening may be oriented at an approximately 90 (+15) degree angle to the diagonals of the magnet assembly. One advantage to rotating the inner suspension elements relative to the outer suspension elements as described is an increased stiffness of the suspension system in the plane which is parallel to the radiating surface. In addition, the suspension elements may have a width dimension which also helps with rocking mode prevention. For example, the suspension elements may have a width dimension that covers up to 1/12th of the side of the magnet assembly to which it is attached. In addition, the proposed suspension assembly enables the magnet motor assembly thickness to be used by the suspension assembly, giving more room for the suspension geometry. Still further, the suspension assembly disclosed herein does not have to collapse completely to allow the maximum excursion of the magnet motor assembly. This, in turn, improves the linear operation range of the suspension assembly. Moreover, the suspension member (e.g., spring) can be made larger than the excursion space (e.g. greater z-height), enabling the suspension to be more flexible and reach a lower resonance frequency with the moving mass (e.g., magnet assembly) for a given fixed thickness. In addition, in the case of a leaf spring suspension member, the leaf spring provides high rigidity within the parallel surface to the radiating surface, and protects the voice coil from getting into contact with metal components of the magnet. In addition, the combined two suspension system may provide additional advantages, including but not limited to, minimizing bending of the magnet assembly when the device is held in a vertical orientation, and may be effective towards high acceleration values which can be caused by drop.
More specifically, aspects of the disclosure include a transducer assembly having a stiffener plate with a first side and a second side, and a voice coil coupled to the second side of the stiffener plate. A magnet assembly is positioned along the second side of the stiffener, the magnet assembly operable to produce a magnetic field that causes a movement of the magnet assembly relative to the voice coil. In addition, a spring suspends the magnet assembly from the stiffener plate such that the movement of the magnet assembly drives a movement of the stiffener plate. The spring may be arranged around a perimeter of the magnet assembly and include a first extension member attached to the second side of the stiffener plate and a second extension member attached to a bottom side of the magnet assembly, which faces away from second side of the stiffener plate. The magnet assembly may include a polygon shape having a number of sides, and the spring is positioned along one of the sides. The spring may be one of a plurality of springs symmetrically arranged around a perimeter of the magnet assembly. For example, the spring may be a first spring, the assembly may further include a second spring, and the first leaf spring is positioned around a perimeter of the magnet assembly and the second spring is positioned within a center opening of the magnet assembly. The second spring may be arranged at any angle relative to the first leaf spring. In addition, an actuating surface may be coupled to the first side of the stiffener plate. The actuating surface may include a wall of a device within which the transducer assembly is integrated.
In another aspect, a transducer assembly is provided including a driven member having a first side and a second side, a voice coil coupled to the second side of the driven member, a magnet assembly positioned along the second side of the driven member, the magnet assembly operable to produce a magnetic field that causes a movement of the magnet assembly relative to the voice coil, and a plurality of springs coupling the magnet assembly to the driven member to drive a movement of the driven member. The driven member may be any structure that can be caused to move by the magnet assembly. For example, the driven member may be a stiffener plate attached to an actuating surface (e.g., a wall of an enclosure), or the driven member could be the actuating surface such that a stiffener plate is omitted. In some aspects, each spring of the plurality of springs may include a first extension member attached to the second side of the driven member and a second extension member attached to a bottom side of the magnet assembly. The plurality of springs may be symmetrically arranged around the magnet assembly. The plurality of springs may include a first set of springs and a second set of springs. The first set of springs may be arranged around a perimeter of the magnet assembly, and the second set of springs may be arranged around a center opening of the magnet assembly. The perimeter of the magnet assembly may be defined by sides of the magnet assembly connected to form a polygon shape and the second set of springs are positioned along each diagonal axis of the polygon shape. In addition, the center opening of the magnet assembly may include a polygon shape. Each spring of the second set of springs may be oriented 90 degrees+/−15 degrees with respect to the diagonal axes of the magnet assembly perimeter. In some aspects, the bottom side of the magnet assembly may include a bottom recessed region within which the second extension member is positioned, and a top side of the magnet assembly comprises a top recessed region aligned with the first extension member.
In still further aspects, a transducer assembly is provided including a stiffener plate having a first side operable to be connected to an actuating surface and a second side, a voice coil coupled to the second side of the stiffener plate, a magnet assembly positioned along the second side of the stiffener plate, the magnet assembly operable to produce a magnetic field that causes a movement of the magnet assembly relative to the voice coil, and a plurality of suspension members coupling the magnet assembly to the stiffener plate and the movement of the magnet assembly drives a movement of the stiffener plate, wherein the plurality of suspension members are symmetrically arranged around the magnet assembly. The plurality of suspension members may include leaf springs having a first end coupled to the second side of the stiffener plate and a second end coupled to a bottom side of the magnet assembly. The plurality of suspension members may be equally arranged around a perimeter of the magnet assembly and a center opening of the magnet assembly. In some cases, at least one of the plurality of suspension members may be arranged around the center opening is rotated at least 15 degrees relative to at least one of the plurality of suspension members arranged around the perimeter. In some aspects, the first side of the stiffener plate is connected to the actuating surface, and the movement of the stiffener plate causes a vibration of the actuating surface. In an additional aspect, the transducer may be constructed without a stiffener plate and the suspension and voice coil may be coupled directly to the actuating surface.
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.
The aspects 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” aspect in this disclosure are not necessarily to the same aspect, and they mean at least one.
In this section we shall explain several preferred aspects of this invention with reference to the appended drawings. Whenever the shapes, relative positions and other aspects of the parts described in the aspects 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 aspects 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 aspects 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's or feature'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.
Transducer assembly 100 may include a driven member 102 that is coupled to a magnet assembly (not shown) by a number of suspension members 104A, 104B, 104C and 104D. The driven member 102 may be any type of structure that can be attached to another structure or surface that is to be actuated (e.g., a wall of the enclosure) to drive an actuation (e.g., vibration) of the structure or surface to be actuated, or may be the actuating surface itself. For example, in one aspect, driven member 102 may be a stiffener plate that is attached to an actuating surface (e.g., the structure to be actuated). The driven member 102 may therefore also be referred to herein interchangeably as a stiffener plate. The stiffener plate 102 may be a planar structure having a polygon shape defined by multiple sides, as shown. For example, the stiffener plate 102 can have a square shape, a rectangular shape, a triangular shape, or the like. The suspension members 104A-104D may, in turn, be arranged around the perimeter of the plate 102. For example, there may be one suspension member 104A-104D arranged along each sided of the plate 102. The suspension members 104A-104D may be evenly spaced around plate, or symmetrically arranged around plate 102, as shown.
The suspension members 104A-104D may be any type of suspension member suitable for movably coupling the stiffener plate 102 to the magnet assembly. In addition, the suspension members 104A-104D may have a thin profile (e.g. z-height), or otherwise be configured, so that it does not increase the z-height of the overall assembly. For example, suspension members 104A-104D may be of a size and shape that can be arranged around the perimeter of the stiffener plate 102 and the magnet assembly, as opposed to between the stiffener plate 102 and the magnet assembly. Still further, suspension members 104A-104D may have any size and shape sufficient to prevent a translation, or other motion of the associated magnet assembly, that is not parallel to the symmetry axis direction (e.g., vibration axis), relative to the stiffener plate 102. Representatively, suspension members 104A-104D may be resilient structures, including but not limited to, springs, leaf springs, or the like having at least one angle or joint, as will be described further in reference to
As previously discussed, the suspension members 104A, 104C (as well as 104B, 104C although not shown) are relatively low profile structures which extend outwardly, around a perimeter of the magnet assembly 202, as opposed to extending above the magnet assembly 202. For example, suspension members 104A, 104C may be continuous, integrally formed structures that have one end attached to a bottom side of the stiffener plate 102, a resilient portion that wraps around the side of magnet assembly 202, and another end attached to the bottom side of magnet assembly 202. Suspension members 104A, 104C therefore allow the magnet assembly 202 to move relative to stiffener plate 102, as illustrated by arrow 212, without occupying the excursion space 214 between plate 102 and magnet assembly 202, or adding to the z-height of the overall assembly. In addition, it should be understood that while the suspension members (e.g., members 104A-104D) are described as being attached to the stiffener plate 102, in some aspects, the stiffener plate and suspension members may be manufactured as one integrally formed structure such that the suspension members and stiffener plate are a single piece. Alternately, as previously discussed, the stiffener plate 102 may be omitted from the transducer assembly and the suspension members 104A-104D may be attached to the actuating surface 208.
Representatively, it can be seen from
In some cases, recessed regions 314, 316 may be formed in the top side 310 and the bottom side 308 of magnet assembly 202, respectively, to accommodate the top and bottom arms 302, 304, respectively. For example, recessed region 314 may be formed in top side 310 of the top plate 202A of magnet assembly 202, to maximize the excursion space 214 between top plate 202A and stiffener plate 102. In addition, recessed region 316 may be formed in the bottom side 308 of bottom plate 202C, and bottom arm 304 may be positioned within the recessed region 316 so that bottom arm 304 is planar with bottom side 308 or otherwise does not extend below bottom side 308.
To drive such a movement, magnet assembly 202 may include a permanent magnet 202B positioned between top plate 202A and bottom plate 202C, which together form a mass that is movably suspended from stiffener plate 102 having voice coil 210 attached thereto. Magnet assembly 202 is suspended from stiffener plate 102 by suspension member 104A, as previously discussed, but is not otherwise coupled to any other structure along its bottom side 308. Magnet assembly 202 is therefore free to move up and down (e.g., in a direction of arrows 312, 314) and relative to stiffener plate 102. In this aspect, when a current is applied to voice coil 210 (e.g. through a voice coil wire connected to circuitry), magnet assembly 202 produces a magnetic field that causes the voice coil 210 and magnet assembly 202 to move relative to one another. For example, the magnetic field may create a repelling force causing the voice coil 210 and magnet assembly 202 to want to move away from one another. For example, voice coil 210 wants to move in an upward direction and magnet assembly 202 wants to move in a downward direction. Voice coil 210, however, is attached to stiffener plate 102 and actuating surface 208, which may be more resistant to movement than magnet assembly 202. For example, the stiffener plate 102 may be glued to an actuating surface 208 that is a surface or wall of a device enclosure within which the assembly 100 is integrated. Magnet assembly 202 therefore begins to move and this movement of magnet assembly 202, ultimately causes a movement or vibration of the stiffener plate 102, and actuates (e.g., vibrates) the actuating surface 208 coupled thereto. Changing or discontinuing the current applied to the voice coil 210 may change the direction in which the voice coil 210 and/or magnet assembly 202 want to move relative to one another.
Opening 502 may have any shape suitable for accommodating this arrangement. For example, opening 502 may be any shape having sides along each diagonal axis of the magnet assembly 202 and to which suspension members 504A-504D may be attached. For example, in the illustrated configuration, magnet assembly 202 has a substantially square shape defined by four sides, and therefore two diagonal axes 506, 508. Opening 502 may therefore have a hexagon shape defined by six sides, and at least three diagonals, so that at least three sides for attaching the suspension members 504A-504D are aligned with each of the diagonal axes 506, 508, etc. Other opening 502 and magnet assembly 202 shapes are contemplated.
For example,
In this aspect, electronic device 900 includes a processor 912 that interacts with camera circuitry 906, motion sensor 904, storage 908, memory 914, display 922, and user input interface 924. Main processor 912 may also interact with communications circuitry 902, primary power source 910, transducer 918 and microphone 920. Transducer 918 may be a speaker and/or the transducer assembly described herein. The various components of the electronic device 900 may be digitally interconnected and used or managed by a software stack being executed by the processor 912. Many of the components shown or described here may be implemented as one or more dedicated hardware units and/or a programmed processor (software being executed by a processor, e.g., the processor 912).
The processor 912 controls the overall operation of the device 900 by performing some or all of the operations of one or more applications or operating system programs implemented on the device 900, by executing instructions for it (software code and data) that may be found in the storage 908. The processor 912 may, for example, drive the display 922 and receive user inputs through the user input interface 924 (which may be integrated with the display 922 as part of a single, touch sensitive display panel). In addition, processor 912 may send a current or signal (e.g., audio signal) to transducer 918 to facilitate operation of transducer 918.
Storage 908 provides a relatively large amount of “permanent” data storage, using nonvolatile solid state memory (e.g., flash storage) and/or a kinetic nonvolatile storage device (e.g., rotating magnetic disk drive). Storage 908 may include both local storage and storage space on a remote server. Storage 908 may store data as well as software components that control and manage, at a higher level, the different functions of the device 900.
In addition to storage 908, there may be memory 914, also referred to as main memory or program memory, which provides relatively fast access to stored code and data that is being executed by the processor 912. Memory 914 may include solid state random access memory (RAM), e.g., static RAM or dynamic RAM. There may be one or more processors, e.g., processor 912, that run or execute various software programs, modules, or sets of instructions (e.g., applications) that, while stored permanently in the storage 908, have been transferred to the memory 914 for execution, to perform the various functions described above.
The device 900 may include communications circuitry 902. Communications circuitry 902 may include components used for wired or wireless communications, such as two-way conversations and data transfers. For example, communications circuitry 902 may include RF communications circuitry that is coupled to an antenna, so that the user of the device 900 can place or receive a call through a wireless communications network. The RF communications circuitry may include a RF transceiver and a cellular baseband processor to enable the call through a cellular network. For example, communications circuitry 902 may include Wi-Fi communications circuitry so that the user of the device 900 may place or initiate a call using voice over Internet Protocol (VOIP) connection, transfer data through a wireless local area network.
The device may include a transducer 918. Transducer 918 may be a speaker and/or a transducer assembly such as that described in reference to
The device 900 may further include a motion sensor 904, also referred to as an inertial sensor, that may be used to detect movement of the device 900, camera circuitry 906 that implements the digital camera functionality of the device 900, and primary power source 910, such as a built in battery, as a primary power supply.
While certain aspects 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. The description is thus to be regarded as illustrative instead of limiting. In addition, to aid the Patent Office and any readers of any patent issued on this application in interpreting the claims appended hereto, applicants wish to note that they do not intend any of the appended claims or claim elements to invoke 35 U.S.C. 112(f) unless the words “means for” or “step for” are explicitly used in the particular claim.
