Actuator module with reduced stiffness connection to a panel and mobile device including the same

Abstract

A panel audio speaker includes an actuator module. The actuator module includes an intermediate layer. The intermediate layer has a voice coil connected to the intermediate layer at a first surface. The actuator module includes a magnet assembly having a plurality of magnets. At least one pair of magnets is separated by an air gap. The actuator module includes: a frame connected to the intermediate layer at the first surface; one or more springs connected to the frame and suspending the magnet assembly relative to the frame so that the voice coil extends at least partially into the air gap; and a spacer connected along a portion of the intermediate layer at a second surface of the intermediate layer opposite the first surface. The spacer has a stiffness at a connection area with the intermediate layer that is less than a stiffness of the intermediate layer at the connection portion.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Patent Application No. 62 / 948,195, filed December 13, 2019, which is incorporated herein by reference in its entirety. Background Art

[0003] Many traditional speakers produce sound by inducing piston-like motion in a diaphragm. In contrast, panel audio speakers such as distributed mode speakers (DMLs) operate by inducing uniformly distributed vibration modes in the panel via electroacoustic actuators. The actuators may be electromagnetic actuators that include one or more magnets and a voice coil positioned in the magnetic field of the one or more magnets. The one or more magnets may be moved relative to the voice coil to transmit force to the panel of the panel audio speaker. Summary of the Invention

[0004] An actuator module is disclosed having a reduced stiffness connection between a panel of a panel audio speaker and a component of the actuator module (e.g., a coil). In some examples, the reduced stiffness connection is between the panel of the panel audio speaker and an intermediate layer of the actuator positioned between the coil and the panel. The disclosed actuator module may also have a reduced stiffness connection between the coil and certain large components of the transducer (e.g., a frame of the transducer). For example, the reduced stiffness connection may be achieved by including a spacer between the coil and the panel, thereby allowing the coil to transfer most or all of its kinetic energy to the panel rather than to both the panel and adjacent large transducer components (e.g., a transducer chassis and cover).

[0005] As another example, the spacer can be surrounded by a ring of compliant material positioned between the panel and certain components of the actuator module other than the coil. The compliant material can allow certain components to be weakly coupled to the panel through the ring of compliant material. This can reduce the effect of the actuator's mass on the panel's motion. For example, compared to an actuator with a ring of rigid material between the actuator components and the panel, the effect of the actuator's mass on the panel's motion can be reduced.

[0006] As another example, a reduced-stiffness connection can be achieved by reducing the amount of interlayer material connecting the coil to other large parts of the transducer. For example, a portion of the interlayer can be removed. The removed portion of the interlayer can be shaped to allow the coil to pass through the removed portion. In this way, the coupling of the coil to certain large components of the transducer can be reduced.

[0007] The disclosed actuators may be applicable to panel audio speakers. For example, the disclosed actuators may be applicable to panel audio speakers incorporated into mobile devices (e.g., mobile phones) and wearable devices (e.g., smart watches or head-mounted displays).

[0008] Generally speaking, one innovative aspect of the subject matter described in this specification can be embodied in a panel audio speaker comprising an actuator module. The actuator module comprises: an intermediate layer extending in a plane, the intermediate layer having a first surface; a voice coil connected to the intermediate layer at the first surface, the voice coil defining a coil axis perpendicular to the plane; a magnet assembly comprising a plurality of magnets. At least one pair of the plurality of magnets is separated by an air gap. The panel audio speaker comprises: a frame connected to the intermediate layer at the first surface, one or more springs connected to the frame and suspending the magnet assembly relative to the frame and the intermediate layer so that the voice coil extends at least partially into the air gap, and a spacer connected along a portion of the intermediate layer at a second surface of the intermediate layer opposite the first surface, wherein the stiffness of the spacer at the area connected to the intermediate layer is less than the stiffness of the intermediate layer at the portion of the intermediate layer; and a panel attached to the spacer.

[0009] In some implementations, a panel audio speaker includes an actuator module. The actuator module may include an intermediate layer. The intermediate layer may have a voice coil connected to the intermediate layer at a first surface. The actuator module may include a magnet assembly having a plurality of magnets. At least one pair of magnets may be separated by an air gap. The actuator module may include a frame connected to the intermediate layer at the first surface, one or more springs connected to the frame and suspending the magnet assembly relative to the frame so that the voice coil extends at least partially into the air gap, and a spacer, the spacer being connected along a portion of the intermediate layer at a second surface of the intermediate layer opposite the first surface. The stiffness of the spacer at the connection area with the intermediate layer may be less than the stiffness of the intermediate layer at the connection portion.

[0010] The foregoing and other embodiments can each optionally include one or more of the following features, alone or in combination.

[0011] In some implementations, the plurality of magnets can define an air gap.

[0012] In some implementations, the voice coil has a footprint perpendicular to the plane that is substantially the same shape as a footprint of the spacer perpendicular to the plane.

[0013] In some implementations, the voice coil has a footprint perpendicular to the plane that is the same shape as the footprint of the spacer perpendicular to the plane.

[0014] In some implementations, the voice coil is aligned with the spacer at a portion of the intermediate layer that is connected to the spacer.

[0015] In some implementations, the intermediate layer includes a printed circuit board, a substrate, and a pressure sensitive adhesive.

[0016] In some implementations, the actuator module further includes a ring of compliant material attached to the face plate at a first surface and to a second surface of the intermediate layer.

[0017] In some implementations, the ring of compliant material is parallel to the plane and coplanar with the spacer.The ring of compliant material surrounds the spacer.

[0018] In some implementations, the ring of compliant material is aligned with the frame or with the frame and one or more magnets of the magnet assembly.

[0019] In some implementations, the panel includes a display panel.

[0020] In some implementations, the middle layer includes a hole aligned with the voice coil.

[0021] In some implementations, the aperture is c-shaped.

[0022] In some implementations, the hole is o-shaped.

[0023] In some implementations, the panel audio speaker further includes a support member attached to the actuator module.

[0024] In some implementations, the support member is attached to at least one of the plurality of magnets of the actuator module.

[0025] In some implementations, the panel audio speaker further includes a cover that encloses the magnet assembly and the voice coil in a space defined by the cover and the intermediate layer. The support member is attached to the cover.

[0026] In general, another innovative aspect of the subject matter described in this specification can be embodied in a mobile device or wearable device. The mobile device or wearable device includes a housing and a panel audio speaker. The panel audio speaker includes an actuator module comprising: an intermediate layer extending in a plane, the intermediate layer having a first surface; a voice coil connected to the intermediate layer at the first surface, the voice coil defining a coil axis perpendicular to the plane; and a magnet assembly comprising a plurality of magnets. At least one pair of the plurality of magnets is separated by an air gap. The panel audio speaker includes: a frame connected to the intermediate layer at the first surface; one or more springs connected to the frame and suspending the magnet assembly relative to the frame and the intermediate layer so that the voice coil extends at least partially into the air gap; and a spacer connected along a portion of the intermediate layer at a second surface of the intermediate layer opposite the first surface, wherein the stiffness of the spacer at an area connected to the intermediate layer is less than the stiffness of the intermediate layer at a portion of the intermediate layer; and a panel attached to the spacer; and an electronic control module electrically coupled to the voice coil and programmed to excite the voice coil to couple vibrations to the panel to produce an audio response from the panel.

[0027] In general, another innovative aspect of the subject matter described herein can be embodied in a mobile device or wearable device comprising: a housing and a panel audio speaker as described herein; and an electronic control module electrically coupled to a voice coil and programmed to excite the voice coil to couple vibrations to the panel to generate an audio response from the panel.

[0028] In some implementations, the mobile device is a mobile phone or a tablet computer.

[0029] In some implementations, the wearable device is a smartwatch or a head-mounted display.

[0030] Among other advantages, embodiments include an actuator module having a modified connection to a panel of a panel audio speaker compared to a conventional actuator module connected by conventional means. The disclosed actuator module and connection means allow the panel to vibrate at greater speeds than a panel to which a conventional actuator module is connected by conventional means. The increase in panel speed results in an increase in the sound pressure level (SPL) of the audio produced by the panel. Therefore, another advantage of the disclosed actuator module and connection means is that they can allow for louder panel audio speakers than speakers driven by a conventional actuator module connected to the panel by conventional means. The increase in gain provided by the disclosed actuator module can be more significant at high frequencies, for example, between 5kHz and 20kHz.

[0031] Other advantages will be apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1is a perspective view of an embodiment of a mobile device including a panel.

[0033] Figure 2 yes Figure 1 Schematic cross-sectional view of a mobile device.

[0034] Figure 3 is an exploded perspective view of an actuator module including a spacer.

[0035] Figure 4A yes Figure 3 Cross-sectional view of the actuator module and spacer, Figure 3 The spacer in the Figure 1 panel.

[0036] Figure 4B is a cross-sectional view of an actuator module including a ring of compliant material.

[0037] Figure 5A yes Figure 3 A perspective bottom view of the actuator module, Figure 3 The spacers are removed to reveal the actuator module's pressure-sensitive adhesive.

[0038] Figure 5B is a perspective bottom view of an actuator module with an o-shaped cutout removed from a middle layer of the actuator module.

[0039] Figure 6A is a perspective view of an actuator module including an intermediate layer having a c-shaped hole.

[0040] Figure 6B A bottom view of an example actuator module including an L-shaped aperture is shown.

[0041] Figure 6C Shown is a bottom view of an example actuator module including two parallel holes.

[0042] Figure 7A is a graph showing a curve corresponding to the average velocity of an undamped panel driven by a reference actuator module and a curve corresponding to the average velocity of an undamped panel driven by a modified actuator module.

[0043] Figure 7B is shown corresponding to the damping panel (about Figure 7A The curves of the sound pressure level output by the reference actuator module described above connected to the damping panel) and the corresponding curves of the sound pressure level output by the same panel (about Figure 7A A graph of the sound pressure level output by a modified actuator module described is connected to the same panel.

[0044] Figure 7C is a graph showing the velocity of the coil corresponding to the reference actuator module and the velocity of the coil corresponding to the reference actuator module. Figure 7A A graph depicting the velocity curve of the coil of the modified actuator.

[0045] Figure 7D is a graph showing curves corresponding to the average velocity of an undamped panel driven by a reference actuator module, a module with an “o” shaped cutout, and a module with spacers.

[0046] Figure 7E is a graph showing curves corresponding to the velocities of the coils of a reference actuator module, an “o”-cut actuator, and an actuator with a spacer.

[0047] Figure 7F is a graph 700F showing two curves illustrating the possible gains achieved by reducing the mass of the actuator coupled to the panel.

[0048] Figure 8A is a graph showing the effect of spacers on the velocity of a damping panel when attaching a reference actuator module to the damping panel.

[0049] Figure 8B Is to show about Figure 8A A graph describing the difference between two curves.

[0050] Figure 8C is a graph showing simulated panel velocity for various masses and inductances of the actuator module.

[0051] Figure 8D is a graph showing simulated sound pressure levels output by an actuator-driven panel for various masses and inductances of the actuator module.

[0052] Figure 9 is a schematic diagram of an embodiment of an electronic control module for a mobile device.

[0053] Like reference symbols in the various drawings denote like elements. DETAILED DESCRIPTION

[0054] The present disclosure features an actuator for a panel audio speaker such as a distributed mode speaker (DML). Such a speaker can be integrated into a mobile device, such as a mobile phone. For example, referring to Figure 1 , the mobile device 100 includes a device housing or chassis 102 and a touch display panel 104, which includes a flat panel display (e.g., an OLED or LCD display panel) with integrated panel audio speakers. For ease of reference, Figure 1A Cartesian coordinate system with x, y, and z axes is also included. The mobile device 100 interfaces with the user in a variety of ways, including by displaying images and receiving touch input via the touch display panel 104, or simply panel 104. Typically, the mobile device has a depth (in the z-direction) of approximately 10 mm or less, a width (in the x-direction) of 60 mm to 80 mm (e.g., 68 mm to 72 mm), and a height (in the y-direction) of 100 mm to 160 mm (e.g., 138 mm to 144 mm).

[0055] The mobile device 100 also generates audio output. The audio output is generated using a panel audio speaker that produces sound by vibrating the flat panel display. The display is connected to an actuator, such as a distributed mode actuator or DMA, or an electromagnetic actuator. The actuator is a movable component arranged to apply force to a panel (e.g., panel 104) to cause the panel to vibrate. The vibrating panel generates sound waves, including sound waves in the human audible range, such as sound waves in the range of 20 Hz to 20 kHz.

[0056] Figure 1 Also shown is the Figure 2 The dashed lines in the cross-section directions are shown in the reference Figure 2 , a cross-section of the mobile device 100 illustrates the device chassis 102 and the touch display panel 104. The device chassis 102 has a depth measured along the z-direction and a width measured along the x-direction. The device chassis 102 also has a rear panel formed by a portion of the device chassis 102 that extends primarily in the xy plane. The mobile device 100 includes an actuator 210 that is housed in the chassis 102 behind the panel 104 and is connected to the back of the panel 104. Generally speaking, the actuator 210 is sized to fit within the volume constrained by the other components in the chassis, including the electronic control module 220 and the battery 230.

[0057] Now refer to Figure 3 , an exploded perspective view of the actuator module 300 includes a spacer 306. The actuator module 300 also includes a cover 302, a moving magnet system 310, a coil 304, and an intermediate layer 320, which includes a printed circuit board (PCB) 322, a substrate 324, and a pressure sensitive adhesive (PSA) 326. The actuator module 300 can be used to drive a panel of a panel audio speaker, such as the panel 104, so that the panel generates sound waves.

[0058] The actuator module 300 can be relatively compact. For example, the housing 302, which has a substantially square profile in the xy plane, can have a side length (i.e., in the x or y direction) of approximately 25 mm or less (e.g., 20 mm or less, 15 mm or less, such as 14 mm, 12 mm, 10 mm or less). The height of the actuator module (i.e., its dimension in the z direction) can be approximately 10 mm or less (e.g., 8 mm or less, 6 mm or less, 5 mm or less). The housing 302 and the frame 312 are connected to the base plate 324.

[0059] Although Figure 3 shows an exploded perspective view of the actuator module 300, Figure 4A A cross-sectional view of the actuator module 300 and the spacer 306 is shown, wherein the spacer is connected to the panel 104. Figure 3 and 4A As shown, mobile magnet system 310 includes a frame 312 to which two springs 314a and 314b are connected. Frame 312 is also connected to base plate 324. Mobile magnet system 310 also includes a magnet assembly including magnets 406 and 408. Magnets 406 and 408 are suspended relative to frame 312 by back plate 316 and by springs 314a and 314b. Springs 314a and 314b allow magnets 406 and 408 to move in the z-direction. Magnets 406 and 408 are separated from each other by an air gap 402.

[0060] A first side of the spacer 306 is attached to the display panel 104. The spacer may have a thickness (i.e., in the z-direction) of approximately 1 mm or less (e.g., 0.8 mm or less, 0.75 mm or less, 0.5 mm or less). The spacer may be formed from a metal or plastic material. For example, the spacer 306 may be made of stainless steel, copper, lead, tin, aluminum, or a thermoplastic polymer.

[0061] A second side of spacer 306, opposite the first side, is connected along a portion of intermediate layer 320. Intermediate layer 320 couples the second side of spacer 306 to coil 304. For example, PCB 322 is connected to substrate 324, which is connected to PSA 326. Coil 304 is connected to PCB 322, while spacer 306 is connected to PSA 326. PSA 326 can be, for example, a thin, flexible PSA tape, glue, or spray adhesive. PSA 326 can have a thickness (i.e., in the z-direction) of approximately 0.15 mm or less (e.g., 0.1 mm or less, 0.08 mm or less, or 0.05 mm or less).

[0062] The intermediate layer 320 may include a hole 323 aligned with the coil 304 in the z-direction. For example, the hole 323 may have a shape similar to that of the voice coil 304 in the xy plane. In some examples, a portion of the hole may correspond to a portion of the inner edge and / or outer edge of the coil 304 in the xy plane. In some examples, the hole is c-shaped. In some examples, the hole is o-shaped. In some examples, the hole is square. The intermediate layer may have a thickness (i.e., in the z-direction) of approximately 3 mm or less (e.g., 2 mm or less, 1.5 mm or less, 1.0 mm or less).

[0063] Coil 304 is not directly connected to moving magnet system 310. Instead, coil 304 extends at least partially into air gap 402 between magnets 406 and 408. Coil 304 may be, for example, a voice coil. The voice coil defines an axis in the z-direction.

[0064] Frame 312 and coil 304 are each connected to a first surface of intermediate layer 320. Thus, frame 312 and coil 304 are indirectly attached to each other via intermediate layer 320. Spacer 306 is connected to a second surface of intermediate layer 320, which is opposite to the first surface. Thus, spacer 306 and coil 304 are connected to opposite sides of intermediate layer 320. Coil 304 can be aligned with spacer 306 at the portion of intermediate layer 320 where spacer 306 is connected.

[0065] Because frame 312 is not connected to panel 104, coil 304, spacer 306, and intermediate layer 320 form a combined mass, referred to as a combined coil mass. When actuator module 300 is used to drive panel 104 as a panel audio speaker system, the combined coil mass moves, for example, in the z-direction as the display moves. Moving magnet system 310 forms a separate mass that is movable relative to coil 304. Therefore, moving magnet system 310 is only indirectly connected to panel 104.

[0066] The weight of the moving magnet system 310 is greater than the weight of the coil 304. For example, the weight of the moving magnet system 310 can be many times greater than the weight of the coil 304 (e.g., 2 times or more, 2.5 times or more, 3 times or more). Due to the relative weight of the moving magnet system 310 and the coil 304, the weight of the moving magnet system may hinder the movement of the panel 104 during operation of the actuator module and otherwise reduce the sound output of the display. In other words, increasing the mass of the moving magnet system will reduce the speed of the display, which will reduce the sound output of the display. Therefore, the size, position and stiffness of the spacer 306 can be selected so that the spacer can improve the output of the panel 104 at at least some frequencies.

[0067] Generally speaking, the stiffness of the spacer 306 at the area where it is connected to the middle layer 320 is less than the stiffness of the middle layer 320 at the portion of the middle layer 320 that is connected to the spacer 306. In some examples, the spacer 306 can have a stiffness that is lower than the combined stiffness of each sub-layer of the middle layer 320. In some embodiments, the stiffness of the spacer 306 is selected to promote resonance between the mass of the coil 304 and the combined stiffness of the middle layer 320 and the spacer 306. Among other advantages, the resonance between the coil 304 and the moving magnet system 310 can improve the output of a panel audio speaker to which the actuator module 300 is attached.

[0068] In some implementations, stiffness can refer to stiffness in the z-direction.

[0069] For example, in some implementations, the equation To calculate the angular resonant frequency ω of the coil 304 and / or moving magnet system 310, where k is the combined stiffness of the interlayer, spacer, and panel; and m is the mass of the coil. For a frequency of 8 kHz and a mass of 0.2 g, an example stiffness may be k = mω 2 =(0.2e-3)(2πf) 2 =5.1e5 N / m. The combined stiffness of the spacer, the intermediate layer, and the panel can be in the range of about 1.2e5 N / m to about 2.1e6 N / m. The stiffness of the intermediate layer 320 at the portion of the intermediate layer 320 connected to the spacer 306 can be, for example, in the range of about 5.0e5 N / m to 1.0e6 N / m. The stiffness of the spacer 306 at the area connected to the intermediate layer 320 can be, for example, in the range of about 1.2e5 N / m to 5.0e5 N / m.

[0070] The spacer 306 is shaped so that its footprint, i.e., its profile when viewed in the xy plane, is substantially the same as the footprint of the coil 304. The outer edges of the coil 304 and the spacer 306 are substantially square, with rounded corners and enclosing the internal hole. The spacer 306 can be classified as "o-shaped," having a hole in the center of the spacer 306 with the spacer material surrounding the hole. Although Figure 3 An embodiment is shown in which the spacer 306 is o-shaped, but other shapes are possible. In some embodiments, the spacer can be substantially square with rounded corners and no internal holes rather than o-shaped, that is, such that the internal holes of the spacer 306 are filled. In such an embodiment, the length and width of the spacer measured in the x and y directions can be approximately the same as the length and width of the coil 304 measured in the x and y directions.

[0071] In addition to including spacers such as spacer 306, the actuator module may also include a ring of compliant material surrounding the spacer. Figure 4B , actuator module 400 includes the components described with respect to actuator module 300 , with the addition of a ring 410 of compliant material, referred to as compliant ring 410 .

[0072] Compliant ring 410 is positioned between faceplate 104 and moving magnet system 310. In some examples, one surface of compliant ring 410 is attached to faceplate 104 and another surface of compliant ring 410 is attached to intermediate layer 320.

[0073] In some examples, the compliant ring 410 is coplanar with the spacer 306. In some examples, the compliant ring 410 surrounds the spacer 306. In some examples, the compliant ring is aligned in the z-direction with the frame 312. In some examples, the compliant ring is aligned with the frame 312 and aligned in the z-direction with at least one of the magnets of the magnet assembly.

[0074] exist Figure 4B In the example shown, a compliance ring 410 is located between the panel 104 on one side and the frame 312 and magnets 406 on the opposite side. The inclusion of the compliance ring 410 improves the stability of the structure under drop conditions and during normal operation, at the expense of increased coupling between the panel and the mass of the frame and cover.

[0075] The stiffness of the compliant ring 410 is significantly lower than the stiffness of the spacer 306 (e.g., 12 times lower, 10 times lower, or 8 times lower). The compliant ring 410 is made of a material having viscoelastic properties that promotes energy absorption, that is, it should be a material that promotes damping. The compliant material can be, for example, a foam or elastomeric material, such as a polyurethane foam.

[0076] In other embodiments, the flexible ring can be positioned between the panel 104 and one or more of the heaviest components of the moving magnet system. For example, the flexible ring can be positioned between the panel 104 and the frame of the actuator module, or between the display and one or more support plates of the actuator module.

[0077] Although Figure 3 and 4A An embodiment is shown in which the coil 304 is indirectly attached to the panel 104 via the intermediate layer 320, but in some embodiments, the coil can be directly attached to the display. Although the intermediate layer 320 is located between the coil 304 and the panel 104; therefore, to prevent the coil from being directly attached to the display, a portion of the intermediate layer can be removed.

[0078] Figure 5AA perspective bottom view of the actuator module 300 is shown with the spacer 306 removed to reveal the PSA 326. The actuator module 300 includes a housing 302, a moving magnet system 310, and a coil 304 (not shown). The actuator module 300 also includes an intermediate layer 320 that includes the PSA 326. No portion of the intermediate layer 320 is removed.

[0079] Figure 5B A perspective bottom view of actuator module 500 is shown with an o-shaped cutout or hole 502 removed from an intermediate layer 520. O-shaped hole 502 completely separates an inner portion 526a of PSA 526 from an outer portion 526b of PSA 526. As with actuator module 300, actuator module 500 includes a housing 302, a moving magnet system 310, and a coil 304 (not shown).

[0080] exist Figure 5B In the example shown, O-shaped hole 502 extends through the entire intermediate layer 520. However, in some embodiments, only certain sublayers of intermediate layer 520 are cut, such as the layer or layers with the greatest rigidity. In some embodiments, the intermediate layer may include: PSA; one or more polyimide layers, such as for insulation; and a layer of a rigid material such as aluminum. For example, substrate 324 may be a rigid layer formed from a metal such as aluminum, tin, or copper. In such an embodiment, the rigid material layer and the one or more polyimide layers may be cut without cutting the PSA. The PSA does not need to be cut because it is compliant and will provide a relatively compliant connection between the coil and other large components of the actuator module. In these embodiments, the thickness of the intermediate layer at the hole may be, for example, approximately 0.15 mm or less (e.g., 0.1 mm or less, 0.08 mm or less, 0.05 mm or less). The thickness of the intermediate layer in areas other than the hole may be, for example, approximately 3 mm or less (e.g., 2 mm or less, 1.5 mm or less, 1.0 mm or less).

[0081] Like the intermediate layer 320, the intermediate layer 520 includes a PCB, a substrate, and a PSA. Figure 5B is covered in the image, but PSA 526 is visible. Figure 5A and 5B Panel 104 is omitted. The o-shaped portion is removed from the PCB, substrate, and PSA 526 of the middle layer 520 so that the force generated by the coil 304 can pass through the middle layer 520 and into the panel 104. The o-shaped hole 502 in the middle layer 520 separates the inner portion 526a from the outer portion 526b of the PSA 526. In some examples, the coil 304 is connected to the inner portion 526a.

[0082] exist Figure 5BIn the example, with Figure 5A In contrast, the coil 304 has reduced coupling to the large components of the actuator module (e.g., the frame 312 and the magnets 406 and 408). Due to the reduced coupling via the intermediate layer 520, the coil 304 of the actuator module 500 can move more freely compared to embodiments in which the intermediate layer 320 couples the coil to the large components of the actuator. The increased freedom of the coil 304 results in increased velocity for the same excitation force, and some of this increased velocity can propagate to the rest of the panel 104 despite the large components being coupled to the display. This can allow the display to exhibit increased response at at least some frequencies compared to the frequency response exhibited by the panel 104 when the intermediate layer 320 is used to couple the coil 304 to the large components of the actuator module.

[0083] In some implementations, instead of forming holes in the intermediate layer, the PSA of the intermediate layer can be removed so that there is a physical gap between the exterior of the actuator module and the panel 104. The intermediate layer (eg, including the substrate 324) can thus serve as a support member for the actuator module.

[0084] In embodiments where the intermediate layer 320 is connected to the panel 104, the panel 104 supports most or all of the mass of the actuator module. Figure 5B In the example shown, panel 104 can move more freely because the mass coupled to the panel is reduced. That is, because components of actuator module 500 other than coil 304 are not connected to panel 104, the mass coupled to the panel is reduced. The reduction in mass coupled to panel 104 can allow the display to exhibit an increased response at at least some frequencies compared to the frequency response exhibited by panel 104 when intermediate layer 320 is connected to the display.

[0085] Although Figure 5B The actuator module 500 is shown to include an intermediate layer 520 having o-shaped holes cut out of the intermediate layer, but in some embodiments, holes of different shapes may be cut out of the intermediate layer of the actuator module. For example, referring to Figure 6A 6 , a perspective view of actuator module 600 includes an intermediate layer 620 having a C-shaped aperture 602. Like actuator module 300, actuator module 600 includes housing 302, moving magnet system 310, and coil 304 (not shown). Like intermediate layers 320 and 520, intermediate layer 620 includes a PCB, a substrate, and a PSA. While the PCB and substrate of intermediate layer 620 are obscured in FIG6 , PSA 626 is visible. Panel 104 is omitted from FIG6 .

[0086] Compare PSA 326 and PSA 626, the latter having a C-shaped hole 602 instead of an O-shaped hole. Coil 304 is attached to intermediate layer 620. That is, coil 304 can be attached to the portion of PSA 626 labeled 626a and outlined in dashed lines. C-shaped hole 602 allows intermediate layer 620 to weakly couple coil 304 to the rest of actuator module 600. Compared to O-shaped hole 502, C-shaped hole 602 provides more coupling between coil 304 and the other components of actuator module 600. C-shaped hole 602 also allows for better manufacturability of intermediate layer 620 compared to intermediate layer 520 having O-shaped hole 502.

[0087] In some embodiments, the housing 302 and the moving magnet system 310 are each supported by a support member that is not connected to the intermediate layer 620. For example, in some embodiments, the coil 304 is connected to the intermediate layer 620 at portion 626a, and the intermediate layer is connected to the panel 104. The housing 302 and the moving magnet system 310 are not connected to either the intermediate layer 620 or the panel 104.

[0088] In some embodiments, the intermediate layer may include apertures having shapes other than an "o" or "c" shape. Figure 6B and 6C Bottom views of example actuator modules with apertures of other shapes are shown. Figure 6B A bottom view of an example actuator module 650 is shown having an "L-shaped" hole 652 in an intermediate layer 670. In the actuator module 650, the coil 304 (not shown) is attached to the intermediate layer 670. For example, the coil 304 can be attached to a portion of the PSA 656 labeled 656a and outlined in dashed lines. Compared to the o-shaped hole 502 and the c-shaped hole 602, the L-shaped hole 652 provides more coupling between the coil 304 and other components of the actuator module 600.

[0089] Figure 6C A bottom view of an example actuator module 660 is shown having two parallel holes 662a and 662b in an intermediate layer 680. In actuator module 660, coil 304 (not shown) is attached to intermediate layer 680. For example, coil 304 can be attached to portions of PSA 666 labeled 666a and 666b and outlined in dashed lines. Compared to O-shaped hole 502 and C-shaped hole 602, parallel holes 662a and 662b provide more coupling between coil 304 and other components of actuator module 600.

[0090] Figures 7A to 7F 8A to 8D include graphs simulating the frequency response of panels driven by various example actuator modules. The panel is 10 cm 2An aluminum plate with an example actuator module attached to it at its center. The plate is 1 mm thick. The horizontal axis shows the frequency measured in Hertz. The label F = ±0.5 N refers to the force applied to the moving magnet system and the force applied to the coil.

[0091] exist Figures 7A to 7F As discussed in Figures 8A through 8D, the reference actuator is the actuator module 300 without the spacer 306. The reference actuator is attached to the panel via the intermediate layer 320. That is, the PSA 326 attaches the components of the reference actuator to the surface of the panel.

[0092] Figure 7A 7 is a graph 700A showing a curve 702 corresponding to the average velocity of an undamped panel driven by a reference actuator module and a curve 704 corresponding to the average velocity of an undamped panel driven by a modified actuator module. The vertical axis shows the average velocity of the undamped panel measured in m / s. The modified actuator module corresponding to graph 700A is actuator module 500 having an o-shaped hole 502.

[0093] Figure 7B 7 is a graph 700B showing a curve 706 corresponding to the sound pressure level output by the damping panel to which the reference actuator module is connected. Graph 700B also shows a curve 708 corresponding to the sound pressure level output by the same damping panel to which the modified actuator module is connected. The modified actuator module is as described with respect to Figure 5B Graph 700B shows the increased SPL output of the damping panel driven by the modified actuator module compared to the SPL output of the damping panel driven by the reference actuator module. The increase in SPL corresponds to frequencies between 5 kHz and 20 kHz.

[0094] Although Figure 7A The curve corresponds to the average velocity of the undamped panel, Figure 7C A curve corresponding to the coil speed is shown. Figure 7C is a graph 700C showing a curve 710 corresponding to the coil velocity of the reference actuator module 300 . Figure 7C Also shown is a curve 712 corresponding to the coil speed of the modified actuator module 500. Graph 700C shows that including holes in the intermediate layer 520 and appropriately selecting the through-stiffness can create through-thickness resonance with an associated increase in coil speed. At least some of this increase in coil speed results in an increase in panel speed.

[0095] Figure 7D and 7E Curves corresponding to the velocities of the panel and coil are shown separately. Figure 7DGraph 700D shows a curve 720 corresponding to the velocity of an undamped panel driven by the reference actuator module 300. Graph 700D also shows a curve 722 corresponding to the velocity of a panel coupled to a first modified actuator module having a spacer (e.g., spacer 306). Graph 700D also shows a curve 724 corresponding to the velocity of a panel coupled to a second modified actuator module having a c-shaped cutout or hole (e.g., hole 602 of actuator module 600).

[0096] Graph 700D shows the increased panel velocity at some frequencies for the first and second modified actuator modules compared to the panel velocity of the reference actuator module. For the first modified actuator module with spacers 306, the increase in panel velocity is most significant between frequencies of 1 kHz and 6 kHz. For the second modified actuator with c-shaped aperture 602, the increase in panel velocity is most significant between frequencies above 3 kHz, for example, between 3 kHz and 20 kHz.

[0097] Figure 7E Graph 700E shows a curve 732 corresponding to the velocity of a coil (e.g., coil 304) of a reference actuator module 300. Graph 700E also shows a curve 734 corresponding to the velocity of a coil of a first modified actuator module having spacers 306. Graph 700E also shows a curve 736 corresponding to the velocity of a coil coupled to a second modified actuator module having a c-shaped aperture 602.

[0098] Graph 700E shows the increased coil speed of both the first modified actuator module and the second modified actuator module compared to the coil speed of the reference actuator module. The increase in speed is most significant around the 2 kHz and 4 kHz frequencies. In addition, graph 700E shows the increased coil speed of the first modified actuator module with spacer 306 compared to the second modified actuator with c-shaped aperture 602.

[0099] Figure 7F Graph 700F shows two curves illustrating possible gains achieved by reducing the mass of the actuator coupled to the panel. Curve 742 shows the gain that can be achieved by reducing the mass of the actuator coupled to the panel by half. Curve 744 shows the gain that can be achieved by reducing the mass of the actuator coupled to the panel to zero mass. Graph 700F shows gains of between approximately 2 dB and 4 dB for frequencies between 1 kHz and 10 kHz for a mass reduction of half. Graph 700F also shows gains of between approximately 3 dB and 9 dB for frequencies between 1 kHz and 10 kHz for a mass reduction of zero mass.

[0100] Figure 8A 8 is a graph 800A illustrating the effect on the velocity of a damped 10 cm by 10 cm panel when a spacer, such as spacer 306, attaches a reference actuator module to the damping panel. The vertical axis is the ratio of velocity to a 1 m / s reference velocity and is measured in dB m / s. Curve 802 corresponds to the velocity ratio of the reference actuator module connected to the damping panel, while curve 804 corresponds to the velocity ratio of the reference actuator module attached to the damping panel via spacer 306. The reference actuator module was excited with a 1 volt RMS signal. Graph 800A illustrates the improvement, i.e., increase, in panel velocity for frequencies between 300 Hz and 2.5 kHz and for frequencies between 6 kHz and 10 kHz. Figure 8B is a graph 800B showing the difference between curve 804 and curve 802 .

[0101] Figure 8C Graph 800C shows simulated panel velocity for various masses and inductances of the actuator module. The simulation uses circuit components to represent the mass and inductance of the actuator components. Graph 800C shows curve 812 corresponding to the velocity of an undamped panel driven by a reference actuator module 300. Graph 800C also shows curve 814 corresponding to the velocity of a panel driven by a reference actuator with zero inductance. Graph 800C also shows curve 816 corresponding to the velocity of a panel driven by a reference actuator with zero mass. Graph 800C also shows curve 818 corresponding to the velocity of a panel driven by a reference actuator with zero mass and inductance.

[0102] Graph 800C shows the increased panel speed for reduced mass and reduced inductance. Generally speaking, reduced mass has a greater impact on panel speed than reduced inductance. The increased panel speed due to reduced mass is most significant at frequencies greater than 1 kHz (e.g., between 1 kHz and 20 kHz). The increased panel speed due to reduced inductance is most significant at frequencies greater than 5 kHz (e.g., between 5 kHz and 20 kHz).

[0103] Figure 8DGraph 800D shows simulated sound pressure levels output by panels driven by actuators for various masses and inductances. The simulation uses circuit components to represent the mass and inductance of the components of the actuators. Graph 800D shows curve 822 corresponding to the sound pressure level of an undamped panel driven by a reference actuator module 300. Graph 800D also shows curve 824 corresponding to the sound pressure level output by a panel driven by a reference actuator with zero inductance. Graph 800D also shows curve 826 corresponding to the sound pressure level output by a panel driven by a reference actuator with zero mass. Graph 800D also shows curve 828 corresponding to the sound pressure level output by a panel driven by a reference actuator with zero mass and inductance.

[0104] Graph 800D shows the increased sound pressure level for reduced mass and reduced inductance. Generally speaking, reduced mass has a greater impact on sound pressure level than reduced inductance. The increased sound pressure level due to reduced mass is most significant at frequencies greater than 1 kHz (e.g., between 1 kHz and 20 kHz). The increased sound pressure level due to reduced inductance is most significant at frequencies greater than 5 kHz (e.g., between 5 kHz and 20 kHz).

[0105] Generally speaking, the disclosed actuator is controlled by an electronic control module, such as the one on the Figure 2 The electronic control module 220 in the mobile phone is controlled. Generally speaking, the electronic control module is composed of one or more electronic components that receive input from one or more sensors and / or signal receivers of the mobile phone, process the input, and generate and transmit a signal waveform that causes the actuator 210 to vibrate. For example, the electronic control module can be electrically coupled to the coil 304. The electronic control module can be programmed to energize the coil to couple vibrations to the panel to produce an audio or tactile response from the panel.

[0106] refer to Figure 9 , an exemplary electronic control module 900 for a mobile device (e.g., mobile device 100) includes a processor 910, a memory 920, a display driver 930, a signal generator 940, an input / output (I / O) module 950, and a network / communication module 960. These components are in electrical communication with each other (e.g., via a signal bus 902) and with the actuator 210.

[0107] The processor 910 may be implemented as any electronic device capable of processing, receiving or sending data or instructions. For example, the processor 910 may be a microprocessor, a central processing unit (CPU), an application specific integrated circuit (ASIC), a digital signal processor (DSP), or a combination of these devices.

[0108] The memory 920 has various instructions, computer programs, or other data stored thereon. The instructions or computer programs may be configured to perform one or more of the operations or functions described with respect to the mobile device. For example, the instructions may be configured to control or coordinate the operation of the device's display via the display driver 930, the signal generator 940, one or more components of the I / O module 950, one or more communication channels accessible via the network / communication module 960, one or more sensors (e.g., biometric sensors, temperature sensors, accelerometers, optical sensors, air pressure sensors, humidity sensors, etc.), and / or the actuator 210.

[0109] The signal generator 940 is configured to generate an AC waveform of varying amplitude, frequency, and / or pulse profile suitable for use with the actuator 210 and to produce an acoustic and / or tactile response via the actuator. Although depicted as a separate component, in some embodiments, the signal generator 940 may be part of the processor 910. In some embodiments, the signal generator 940 may include an amplifier, for example, as an integrated or separate component thereof.

[0110] The memory 920 can store electronic data that can be used by the mobile device. For example, the memory 920 can store electronic data or content, such as audio and video files, documents and applications, device settings and user preferences, timing and control signals for various modules, or data and data structures or databases. The memory 920 can also store instructions for recreating various types of waveforms that the signal generator 940 can use to generate signals for the actuator 210. The memory 920 can be any type of memory, such as random access memory, read-only memory, flash memory, removable memory, or other types of storage elements or combinations of such devices.

[0111] As briefly discussed above, the electronic control module 900 may include Figure 9 The various input and output components shown in FIG are used as I / O modules 950. Although the components of I / O modules 950 are Figure 9 Although shown as a single item in FIG, a mobile device may include multiple different input components, including buttons, microphones, switches, and dials for accepting user input. In some embodiments, components of I / O module 950 may include one or more touch sensors and / or force sensors. For example, a display of a mobile device may include one or more touch sensors and / or one or more force sensors that enable a user to provide input to the mobile device.

[0112] Each component of I / O module 950 may include dedicated circuitry for generating signals or data. In some cases, the component may generate or provide feedback for application-specific input corresponding to a prompt or user interface object presented on a display.

[0113] As described above, the network / communication module 960 includes one or more communication channels. These communication channels may include one or more wireless interfaces for providing communication between the processor 910 and an external device or other electronic device. Generally speaking, a communication channel can be configured to send and receive data and / or signals that can be interpreted by instructions executed on the processor 910. In some cases, the external device is part of an external communication network configured to exchange data with other devices. Generally speaking, a wireless interface may include, but is not limited to, radio frequency, light, sound and / or magnetic signals, and may be configured to operate via a wireless interface or protocol. Example wireless interfaces include radio frequency cellular interfaces, fiber optic interfaces, acoustic interfaces, Bluetooth interfaces, near field communication interfaces, infrared interfaces, USB interfaces, Wi-Fi interfaces, TCP / IP interfaces, network communication interfaces, or any conventional communication interfaces.

[0114] In some implementations, one or more communication channels of the network / communication module 960 may include a wireless communication channel between the mobile device and another device (e.g., another mobile phone, a tablet computer, or a computer, etc.). In some cases, the output, audio output, tactile output, or visual display element may be transmitted directly to the other device for output. For example, an audible alarm or visual warning may be transmitted from the mobile device 100 to the mobile phone for output on the device, and vice versa. Similarly, the network / communication module 960 may be configured to receive input provided on another device to control the mobile device. For example, an audible alarm, visual notification, or tactile alarm (or its instructions) may be transmitted from an external device to the mobile device for presentation.

[0115] The actuator technology disclosed herein can be used, for example, in a panel audio system designed to provide acoustic and / or tactile feedback. The panel can be a display system, such as an OLED based on LCD technology. The panel can be part of a smartphone, tablet computer, or wearable device (e.g., a smartwatch or head-mounted device such as smart glasses).

[0116] Other embodiments are within the following claims.

Claims

1. A panel audio speaker, comprising: An actuator module, comprising: an intermediate layer extending in a plane, the intermediate layer having a first surface, a voice coil connected to the intermediate layer at the first surface, the voice coil defining a coil axis perpendicular to the plane, Wherein, the intermediate layer includes: printed circuit boards, substrates, and pressure-sensitive adhesives; and an aperture aligned with the voice coil in a direction perpendicular to the plane, wherein: The hole extends through the printed circuit board, the substrate and the pressure sensitive adhesive, or the hole extending through the printed circuit board and the substrate, and the hole not extending through the pressure sensitive adhesive, a magnet assembly comprising a plurality of magnets, wherein at least one pair of magnets in the plurality of magnets is separated by an air gap, a frame connected to the intermediate layer at the first surface, one or more springs connected to the frame and suspending the magnet assembly relative to the frame and intermediate layer such that the voice coil extends at least partially into the air gap, and a spacer connected along a portion of the intermediate layer at a second surface of the intermediate layer opposite the first surface, wherein the stiffness of the spacer at the region of connection to the intermediate layer is less than the stiffness of the intermediate layer at the portion of the intermediate layer; and A panel is attached to the spacer.

2. The panel audio speaker according to claim 1, wherein The voice coil has a length and width in the plane that are substantially the same as a length and width of the spacer in the plane.

3. The panel audio speaker according to claim 2, wherein: The voice coil is aligned with the spacer in a direction perpendicular to the plane at the portion of the intermediate layer connected to the spacer.

4. The panel audio speaker according to claim 1, wherein The pressure-sensitive adhesive forms the second surface of the intermediate layer connected to the spacer.

5. The panel audio speaker according to claim 1, wherein: The actuator module further comprises a ring of compliant material attached to the panel on a first side and to the second surface of the intermediate layer on a second, opposite side, The ring of compliant material is parallel to the plane and coplanar with the spacer, and The ring of compliant material surrounds the spacer.

6. The panel audio speaker according to claim 5, wherein The ring of compliant material is aligned with the frame or with the frame and one or more magnets of the magnet assembly in a direction perpendicular to the plane.

7. The panel audio speaker according to claim 1, wherein The panel includes a display panel.

8. The panel audio speaker according to claim 1, wherein The hole is c-shaped, and the voice coil is attached to the intermediate layer at a portion of the intermediate layer between ends of the c-shaped hole.

9. The panel audio speaker according to claim 1, wherein The hole is o-shaped and separates an inner portion of the intermediate layer from an outer portion of the intermediate layer in the plane.

10. The panel audio speaker of claim 9, further comprising: a cover enclosing the magnet assembly and the voice coil in a space defined by the cover and the intermediate layer; as well as A support member is attached to the cover or at least one magnet of the plurality of magnets of the actuator module.

11. The panel audio speaker according to claim 1, wherein The hole extends through the printed circuit board, the substrate, and the pressure sensitive adhesive.

12. The panel audio speaker of claim 1, wherein: The hole extends through the printed circuit board and the substrate; and The holes do not extend through the pressure sensitive adhesive.

13. A mobile device comprising: case; The panel audio speaker according to any one of claims 1 to 12; as well as An electronic control module is electrically coupled to the voice coil and programmed to energize the voice coil to couple vibrations to the panel to produce an audio response from the panel.

14. The mobile device according to claim 13, wherein: The mobile device is a mobile phone or a tablet computer.

15. The mobile device according to claim 13, wherein The panel includes a display panel.

16. A wearable device comprising: case; A panel audio speaker according to any one of claims 1 to 12; as well as An electronic control module is electrically coupled to the voice coil and programmed to energize the voice coil to couple vibrations to the panel to produce an audio response from the panel.

17. The wearable device according to claim 16, wherein: The wearable device is a smart watch or a head-mounted display.

18. The wearable device according to claim 16, wherein: The panel includes a display panel.

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