Patent Description:
Many conventional loudspeakers produce sound by inducing piston-like motion in a diaphragm. Panel audio loudspeakers, such as distributed mode loudspeakers (DMLs), in contrast, operate by inducing uniformly distributed vibration modes in a panel through an electro-acoustic actuator. Typically, the actuators are piezoelectric or electromagnetic actuators.

During the operation of a typical actuator, components of the actuator bend, causing these components to experience mechanical stress. This stress may decrease the performance and lifetime of the actuator. Conventional DMAs and EM actuators featuring flexible components with fixed widths and conventional EM actuators having flexible components bent at right angles are particularly susceptible to decreased performance due to mechanical stress. <CIT> discloses a vibration generator which energizes a coil disposed on a stator to move a movable element and generate vibrations. The stator has a base plate positioned under the coil, and a coil base disposed between the base plate and the coil. The coil base has a seat surface on which the coil is placed, and the seat surface is provided at a position except for a position corresponding to an end line of the coil. The end line of the coil is drawn to a side part of the coil through a part which is not provided with the seat surface from a lower side of the coil to the coil base.

Disclosed are improvements to conventional distributed mode actuators (DMAs) and electromagnetic (EM) actuators. For example, implementations of such DMAs and EM actuators feature flexible components with portions having increased dimensions compared to conventional devices. The portions having increased dimensions are strategically located in high stress regions. The components can also be shaped so that the increased dimension does not significantly increase the volume occupied by the actuator.

By attaching a DMA or an EM actuator to a mechanical load, such as an acoustic panel, the actuators can be used to induce vibrational modes in the panel to produce sound.

The invention is as set out in the independent claim and aspects of the present disclosure are defined by the appended claims. In general, we describe an actuator that includes a frame including a panel extending in a plane and a plurality of pillars extending perpendicular from the plane. The actuator also includes a magnetic circuit assembly that includes a magnet and a voice coil, the magnet and voice coil being moveable relative to each other during operation of the actuator in an axial direction along an axis perpendicular to the plane of the panel. The actuator further includes a plurality of suspension members attaching the frame to a first component of the magnetic circuit assembly. Each suspension member includes a vertical segment extending in the axial direction attaching the suspension member to a corresponding one of the pillars. Each suspension member further includes a first arm extending away from the corresponding pillar in a first plane, parallel to the panel's plane to an end attached to the first component of the magnetic circuit assembly. During operation of the actuator the first and second arms of the suspension member are able to flex to accommodate axial displacements of the magnet along the axial direction relative to the voice coil.

Embodiments of the actuator can include one or more of the following features and/or one or more features of other aspects. For example, a thickness of the first arm in the first plane can be varied to reduce a concentration of stress at one or more locations of the suspension member when the suspension member flexes during operation of the actuator. That is, the thickness of the first arm in the first plane can be non-uniform.

In some embodiments, the first arm can include a first straight segment extending away from the corresponding pillar in a first direction in the first plane and a second straight segment connected to the first arm, the second straight segment extending in the first plane orthogonal to the first direction. The first arm can include a first curved segment connecting the first straight segment and the second straight segment. The second straight segment can have a thickness in the first plane that is tapered along the length of the second straight segment. The first arm can include a third straight segment connected to the second straight segment by a second curved segment, the third straight segment extending in the first plane orthogonal to the second straight segment and the third straight segment being attached to the first component of the magnetic circuit assembly.

In some embodiments, the second curved segment has a first radius of curvature along an outer edge that is smaller than a second radius of curvature along an inner edge of the second curved segment.

Each suspension member includes a second arm extending away from the corresponding pillar in a second plane parallel to the panel's plane to an end attached to the first component of the magnetic circuit assembly. The first and second arms can be respectively connected to opposing ends the vertical segment by a corresponding curved segment, the corresponding curved segments extending out of the first and second planes, respectively. The vertical segment and two curved segments can collectively form a C-shaped segment. The curved segments can be free from the corresponding pillar of the frame.

In some embodiments, the first and second arms can be connected by the vertical segment of the suspension member. The ends of the first and second arms can be respectively attached to opposite sides of the first component of the magnetic circuit assembly.

In some embodiments, the first component of the magnetic circuit assembly has a substantially polygonal shape in the plane of the frame and a corresponding suspension member is attached to each respective side of the polygon. That is, the first component of the magnetic circuit assembly has a shape in the plane of the frame which is a polygon. The polygon can be a quadrilateral.

In some embodiments, the voice coil is attached to the frame and the first component of the magnetic circuit assembly includes the magnet.

We also describe a panel audio loudspeaker that includes the actuator described herein. The panel of the panel audio loudspeaker can include a display panel.

We also describe a mobile device that includes an electronic display panel extending in a plane. The mobile device also includes a chassis attached to the electronic display panel and defining a space between a back panel of the chassis and the electronic display panel. The mobile device further includes an electronic control module housed in the space, and the electronic control module includes a processor. In addition, the mobile device includes the actuator described above, the actuator housed in the space and attached to a surface of the electronic display panel.

Among other advantages, embodiments include actuators that have a decreased chance of failure from mechanic stress caused by bending when compared to conventional actuators.

Another advantage is that the actuator occupies substantially the same space as conventional actuators. This can be particularly beneficial where an actuator is integrated into a larger electronic device and is required to fit within a prescribed volume.

Other advantages will be evident from the description, drawings, and claims.

The disclosure features actuators for panel audio loudspeakers, such as distributed mode loudspeakers (DMLs). Such loudspeakers can be integrated into a mobile device, such as a mobile phone, tablet or a wearable device (e.g., smartwatch or head-mounted device, such as smart glasses). For example, referring to <FIG>, a mobile device <NUM> includes a device chassis <NUM> and a touch panel display <NUM> including a flat panel display (e.g., an OLED or LCD display panel) that integrates a panel audio loudspeaker. Mobile device <NUM> interfaces with a user in a variety of ways, including by displaying images and receiving touch input via touch panel display <NUM>. Typically, a mobile device has a depth of approximately <NUM> or less, a width of <NUM> to <NUM> (e.g., <NUM> to <NUM>), and a height of <NUM> to <NUM> (e.g., <NUM> to <NUM>).

Mobile device <NUM> also produces audio output. The audio output is generated using a panel audio loudspeaker that creates sound by causing the flat panel display to vibrate. The display panel is coupled to an actuator, such as a DMA or EM actuator. The actuator is a movable component arranged to provide a force to a panel, such as touch panel display <NUM>, causing the panel to vibrate. The vibrating panel generates human-audible sound waves, e.g., in the range of <NUM> to <NUM>.

In addition to producing sound output, mobile device <NUM> can also produces haptic output using the actuator. For example, the haptic output can correspond to vibrations in the range of <NUM> to <NUM>.

<FIG> also shows a dashed line that corresponds to the cross-sectional direction shown in <FIG>. Referring to <FIG>, a cross-section of mobile device <NUM> illustrates device chassis <NUM> and touch panel display <NUM>. <FIG> also includes a Cartesian coordinate system with X, Y, and Z axes, for ease of reference. Device chassis <NUM> has a depth measured along the Z-direction and a width measured along the X-direction. Device chassis <NUM> also has a back panel, which is formed by the portion of device chassis <NUM> that extends primarily in the XY-plane. Mobile device <NUM> includes an actuator <NUM>, which is housed behind display <NUM> in chassis <NUM> and affixed to the back side of display <NUM>. Generally, actuator <NUM> is sized to fit within a volume constrained by other components housed in the chassis, including an electromechanical module <NUM> and a battery <NUM>.

In general, actuator <NUM> includes a frame that connects the actuator to display panel <NUM> via a plate <NUM>. The frame serves as a scaffold to provide support for other components of actuator <NUM>, which commonly include a flexure and an electromechanical module. The frame may be sufficiently rigid to avoid being substantially deformed as a result of bending.

The flexure is typically an elongate member that extends in the X-Y plane, and when vibrating, is displaced in the Z-direction. The flexure is generally attached to the frame at at least one end. The opposite end can be free from the frame, allowed to move in the Z-direction as the flexure vibrates.

The electromechanical module is typically a transducer that transforms electrical signals into a mechanical displacement. At least a portion of the electromechanical module is usually rigidly coupled to the flexure so that when the electromechanical module is energized, the module causes the flexure to vibrate.

Generally, actuator <NUM> is sized to fit within a volume constrained by other components housed in mobile device <NUM>, including electronic control module <NUM> and battery <NUM>. Actuator <NUM> can be one of a variety of different actuator types, such as an electromagnet actuator or a piezoelectric actuator.

<FIG> show different views of a distributed mode actuator (DMA) <NUM>, which includes an electromechanical module and a flexure. <FIG> is a cross-section of DMA <NUM>, while <FIG> is a top-view of DMA <NUM>. During operation of DMA <NUM>, the electromechanical module displaces a free end of the flexure in the Z-direction.

Referring specifically to <FIG>, in DMA <NUM>, the electromechanical module and flexure are integrated together into a cantilevered beam <NUM> that includes a vane <NUM> and piezoelectric stacks 314a and 314b. Vane <NUM> is an elongate member that is attached at one end to frame <NUM>, which is a stub that attaches the vane to plate <NUM>. Vane <NUM> extends from frame <NUM>, terminating at an unattached end that is free to move in the Z-direction. The portion of vane <NUM> that is attached to frame <NUM> has a width, measured in the Y-direction, which is greater than the width of the portion of the flexure that is unattached. Beam <NUM> is attached to frame <NUM> at a slot <NUM> into which vane <NUM> is inserted. In the examples of <FIG>, piezoelectric stacks 314a and 314b are disposed above and below vane <NUM>, respectively. Each stack 314a and 314b can include one or more piezoelectric layers.

While <FIG> shows a cross-section of DMA <NUM>, <FIG> shows a top view of the DMA. <FIG> includes a top view of vane <NUM>, which is partially obscured by frame <NUM> and piezoelectric stack 314a. Vane <NUM> and piezoelectric stacks 314a and 314b all extend parallel to the XY-plane. When DMA <NUM> is at rest, beam <NUM>, i.e., vane <NUM> and piezoelectric stacks 314a and 314b, remains parallel to the XY-plane. During the operation of DMA <NUM>, piezoelectric stacks 314a and 314b are energized, causing beam <NUM> to vibrate relative to the Z-axis. The vibration of vane 312beam <NUM> causes it to move in the ±Z-directions.

The length of vane <NUM> measured in the X-direction is denoted LF, and is also called the end-to-end extension. <FIG> also shows a length LW, which is discussed in greater detail below with regard to the wings of the flexure. The free end of vane <NUM> has a width WF2. The width of vane <NUM> remains WF2 for the length LF - LW.

The end of vane <NUM>, anchored by frame <NUM> has a first width WF1, which is greater than the width of the frame <NUM>, denoted WS. Towards the anchored end, the width of vane <NUM> increases to form two wings that extend laterally from slot <NUM>. In this implementation, the wings are symmetric about a central axis <NUM> that runs in the X-direction and divides vane <NUM> into symmetric top and bottom portions, although in other implementations, the wings need not be symmetric. Referring to the top wing (i.e., the wing above central axis <NUM>), the edges of the wing are contiguous with the edge of the top portion of vane <NUM> that is parallel to the X-axis. The width of the top wing, denoted WW, is measured from the top edge of vane <NUM>, to the point of the wing farthest from central axis <NUM>. The width of either wing, WW, the width of the free end of the flexure, WF2, and the width of the anchored end of the flexure, WF1, are related by the equation, WF1 = WF2 + 2WW.

Each wing also has a length, denoted LW. In the implementation shown in <FIG>, LW is greater than WW, although in other implementations, LW can be less than or equal to WW. For example, LW and WW can be on the order of approximately <NUM> to <NUM>, e.g., <NUM> to <NUM>, such as about <NUM>.

The width of slot <NUM> is proportioned to be larger than the width of the wings. For example, WS can be two or more times Ww, three or more times Ww, or four or more times Ww. The height of slot <NUM>, as measured in the Z-direction, is approximately equal to the height of vane <NUM>, which can be approximately <NUM> to <NUM>, e.g., <NUM> to <NUM>, such as <NUM> to <NUM>.

In general, the gap between frame <NUM> and piezoelectric stacks 314a and 314b is smaller than either LW or WW. For example, the gap can be one half or less of LW or WW, one third or less of LW or WW, or one fifth or less of LW or WW.

In the example of <FIG>, the width of slot <NUM>, WS, is smaller than the width of vane <NUM> at the free end, WF2. However, in some implementations, WS is larger than WF2.

The wings of vane <NUM> extend on either side of frame <NUM> to distribute mechanical stress that results from the operation of DMA <NUM>. The dimensions of the wings can be chosen such that the wings most effectively distribute stress. For example LF can be on the order of approximately <NUM> or more, <NUM> or more, or <NUM> or more, such as about <NUM> or less, <NUM> or less. As another example, WW can be <NUM> or more, <NUM> or more, or <NUM> or more, such as about <NUM> or less, <NUM> or less.

The shape of the wings is chosen to improve (e.g., optimize) the distribution of stress. For example, when viewed from above, as in <FIG>, the shape of each wing can be a rectangle, a half circle, or a half ellipse.

While <FIG> show an implementation of a DMA having a flexure with two wings that are in the plane of the flexure when the DMA is at rest, other implementations include wings that are not in the plane of the flexure when the DMA is at rest. <FIG> show a cross-section and side view of a DMA <NUM> that includes wings folded out of the XY-plane.

DMA <NUM> includes a beam <NUM> connected to frame <NUM>. Like beam <NUM> of <FIG>, beam <NUM> includes an electromechanical module and a flexure, which are integrated together into a cantilevered beam <NUM> that includes a vane <NUM> and piezoelectric stacks 314a and 314b. Similar to vane <NUM>, vane <NUM> includes a portion that extends primarily in the XY-plane. However, in addition to the portion that extends primarily in the XY-plane, vane <NUM> also includes two wings that are folded out of the XY-plane and extend such that the extending portion forms a plane parallel to the XZ-plane.

In the example of <FIG>, vane <NUM> includes one or more materials that are formed into an extruded plane having a height HF, as shown in <FIG>. Portions of the plane are then shaped to form the wings of vane <NUM>. Because the wings of vane <NUM> are folded out of the XY-plane, the width of the wings, as measured in the Y-direction, is equal to the height of the flexure, HF. Accordingly, the width of the top wing is labeled HF. In other implementations, the height of vane <NUM> can be greater than HF, such that the width of the portion of the flexure surrounding the stub is greater than HF.

Like the wings of vane <NUM>, those of vane <NUM> contribute to the distribution of stress experienced by the vane during the operation of DMA <NUM>. One difference between vane <NUM> and <NUM>, is that the latter can distribute stress on DMA <NUM> while occupying a smaller volume than the former. In systems that include multiple components occupying a limited space, it is advantageous to reduce the volume of the multiple components. For example, the electrical components housed in a mobile device must all fit within the limited space of the chassis of the mobile device. Therefore, the smaller volume occupied by vane <NUM>, when compared to vane <NUM>, is advantageous, although the functional performance of the two vanes is approximately the same.

The one or more piezoelectric layers of piezoelectric stacks 314a and 314b may be any appropriate type of piezoelectric material. For instance, the material may be a ceramic or crystalline piezoelectric material. Examples of ceramic piezoelectric materials include barium titanate, lead zirconium titanate, bismuth ferrite, and sodium niobate, for example. Examples of crystalline piezoelectric materials include topaz, lead titanate, barium neodymium titanate, potassium sodium niobate (KNN), lithium niobate, and lithium tantalite.

Vanes <NUM> and <NUM> may be formed from any material that can bend in response to the force generated by piezoelectric stacks 314a and 314b. The material that forms vanes <NUM> and <NUM> should also being sufficiently rigid to avoid being substantially deformed as a result of bending. For example, vanes <NUM> and <NUM> can be a single metal or alloy (e.g., iron-nickel, specifically, NiFe42), a hard plastic, or another appropriate type of material. The material from which vane <NUM> is formed should have a low CTE mismatch.

While in some implementations, the actuator <NUM> is a distributed mode actuator, as shown in <FIG> and <FIG>, in other implementations, the actuator is an electromagnetic (EM) actuator. Like a DMA, an EM actuator transfers mechanical energy, generated as a result of the actuator's movement, to a panel to which the actuator is attached.

In general, an EM actuator includes a magnetic circuit assembly, which in turn includes a magnet and a voice coil. The EM actuator also includes one or more suspension members that attach the magnetic circuit assembly to a frame. The frame includes one or more pillars each attached to a suspension member along a vertical segment of the suspension member. In addition to the vertical segment, each suspension member also includes an arm that extends perpendicularly from a respective pillar and is attached at one end to the magnetic circuit assembly.

An embodiment of an EM actuator <NUM> according to the claimed subject-matter is shown in <FIG> and <FIG>. Referring to <FIG> and <FIG>, EM actuator <NUM> is shown in a perspective quarter cut view and a different perspective view, respectively. <FIG> shows EM actuator <NUM> at rest, whereas <FIG> shows the actuator during operation.

EM actuator <NUM> includes a frame <NUM>, which connects the actuator to panel <NUM>. Referring to <FIG> and <FIG>, EM actuator <NUM> further includes an outer magnet assembly <NUM>, an inner magnet assembly <NUM>, and a voice coil <NUM>, which collectively form a magnetic circuit assembly <NUM>. Outer magnet assembly <NUM>, which is outlined in dashed lines, includes a ring magnet labeled "A" and a structural element positioned above the magnet A. Inner magnet assembly <NUM>, which is outlined in dotted lines, includes an inner magnet labeled "B" and a structural element positioned above the magnet B. Both magnets A and B are attached to a bottom plate <NUM>.

While, in the example of <FIG>, EM actuator <NUM> includes multiple magnets A and B, in other implementations, actuators can include only a single magnet, e.g., either magnet A or magnet B. Flexures 530a, 530b, 530c, and 530d suspend outer magnet assembly <NUM> from frame <NUM>. Flexures 530a-530d each connect to a separate portion of the structural element of outer magnet assembly <NUM>. While <FIG> and <FIG> show how flexures 530a-530d are integrated into EM actuator <NUM>, <FIG> shows a perspective, isolated view of the flexures.

Between outer magnet assembly <NUM> and inner magnet assembly <NUM>, is an air gap <NUM>. Voice coil <NUM> is attached to frame <NUM> and is positioned in air gap <NUM>. During the operation of EM actuator <NUM>, voice coil <NUM> is energized, which induces a magnetic field in air gap <NUM>. Because magnet assembly <NUM>, is positioned in the induced magnetic field and has a permanent axial magnetic field, parallel to the Z-axis, the magnet assembly experiences a force due to the interaction of its magnetic field with that of the voice coil. Flexures 530a-530d bend to allow electromechanical module <NUM> to move in the Z-direction in response to the force experienced by magnet assembly <NUM>. <FIG> shows an example of how flexures 530a-530d bend during the operation of EM actuator <NUM>.

Frame <NUM> includes a panel that extends primarily in the XY-plane and four pillars that extend primarily in the Z-direction. Each of the four pillars have a width measured in the X-direction that is sized to allow it to attach to one of flexures 530a-530d. Although in this implementation, EM actuator <NUM> includes four pillars, each connected to one of flexures 530a-530d, in other implementations, the actuator can include more than four flexures connected to an equal number of pillars, while in yet other implementations, the actuator can include less than four flexures connected to an equal number of pillars.

Flexures 530a-530d include vertical segments extending in the Z-direction, which attach the flexures to the pillars of frame <NUM>. <FIG> shows flexures 530c and 530d each connected to a respective pillar. Each of the vertical portions of the flexures extend a height of the pillar to which they are attached. For example, the vertical portions of the flexures can extend at least <NUM>% (at least <NUM>%, at least <NUM>%, at least <NUM>%, at least <NUM>%, at least <NUM>%, at least <NUM>%, at least <NUM>%) of the height of each pillar. As another example, the second portions can extend <NUM> or more (<NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more) in the Z-direction. The flexures can be attached to the pillars using an adhesive, a weld, or other physical bond.

Turning now to the structure of the flexures, <FIG> shows a perspective view of a single flexure <NUM>. Although <FIG> shows flexure <NUM>, the discussion of the flexure also describes flexures 530a-530d.

Flexure <NUM> includes two arms <NUM> and <NUM>, both extending parallel to the XY plane. First arm <NUM> includes a first straight segment 611A bounded by dotted lines and extending in the Y-direction. A second straight segment 612A of first arm <NUM> extends in the X-direction. First arm <NUM> further includes a first curved segment 621A that connects first straight segment 611A and second straight segment 612A. A third straight segment 613A of first arm <NUM> extends in the Y-direction. Second straight segment 612A is connected to third straight segment 613A by a second curved segment 622A.

Second arm <NUM> is parallel and identical to first arm <NUM>. Second arm <NUM> includes a first straight segment 611B connected to a second straight segment 612B by a first curved segment 621B. Additionally, second arm <NUM> includes a third straight segment 613B connected to second straight segment 612B by a second curved segment 622B. Although no magnet assembly is shown, third straight segments 613A and 613B are each connected to opposite sides of the magnet assembly. That is, the third straight segment of the first arms of each flexure 630a-630d connect to the structural element positioned above the magnet A, while the third straight segment of the second arms of each flexure 630a-630d connect to bottom plate <NUM>. The structural element positioned above magnet A has a substantially polygonal shape, e.g., a quadrilateral shape.

Flexure <NUM> includes a vertical segment <NUM>. Vertical segment <NUM> extends perpendicular to the first and second arms <NUM> and <NUM>. A first arm connector <NUM> attaches first arm <NUM> to vertical segment <NUM>, while a second arm connector <NUM> attaches second arm <NUM> to vertical segment <NUM>. Both connectors <NUM> and <NUM> are curved such that each the connectors along with vertical segment <NUM> collectively form a C-shaped segment.

As described above with regard to <FIG>, flexures 530a-530d bend to allow electromechanical module <NUM> to move in the Z-direction. In general, portions of a flexure that bend during the operation of an actuator system will experience a higher mechanical stress than portions that do not bend. A flexure may therefore be susceptible to breaking or plastic deformation at the bending portions as a result of the stress.

Accordingly, the width of a flexure can be increased at locations that experience higher stress in order to reduce failure at these points. For example, flexures 530a-530d do not have a fixed width (i.e. flexures 530a-530d have a non-uniform width). Instead, to reduce the chances of failure, flexures 530a-530d have a maximum width at the bending portions. <FIG> are enlarged views of a flexure <NUM>, which show the increased width of the flexure at the bending portions. As discussed above, each flexure 530a-530d is identical to one another. Therefore, the following discussion that references flexure <NUM>, also describes the features of flexures 530a-530d.

<FIG> is a top view of the first arm of flexure <NUM>. The dotted lines show the boundaries of the segments of flexure <NUM>, namely a third segment <NUM>, a second curved segment <NUM>, a second straight segment <NUM>, first curved segment <NUM>, first straight segment 711A, and first arm connector <NUM>.

The free end of the third straight segment of flexure <NUM> has a first width denoted Wmin1, which is measured from the bottom or outside edge of third straight segment <NUM> to the top or inside edge of the third straight segment. Although not shown in <FIG>, each third straight segment of flexure <NUM> is attached to a magnet assembly. A circle positioned on third straight segment <NUM> represents an example position of a connection between flexure <NUM> and the magnet assembly. For example, the circle can be the position of a weld, screw, adhesive, or other type of connection. Wmin1 can be about <NUM> to about <NUM>, e.g. <NUM>, <NUM>, <NUM>.

While the third straight segments of flexure <NUM> is attached to the magnet assembly, second curved segment <NUM> extends away from the connection with the magnet assembly. When the magnet assembly moves along the Z-axis during the operation of the EM actuator, second curved segment <NUM> also moves along the Z-axis. To accommodate the movement of the magnet assembly, second curved segment <NUM> also bends along the Z-axis. The bending along the Z-axis causes second curved segment <NUM> to experience mechanical stress.

Moving counterclockwise from the free end of third straight segment <NUM>, the width of the first portion increases until it reaches a maximum width, Wmax1,which can be about <NUM> to about <NUM>, e.g., <NUM>, <NUM>, <NUM>. As discussed above, the location of Wmax1 corresponds to a portion of second curved segment <NUM> that experiences higher stress during the operation of the EM actuator, as compared to the average stress experienced by flexure <NUM>. The increased width at second curved segment <NUM> reinforces the flexure so that it is less likely to fail during the operation of the EM actuator. More specifically, during operation of the actuator, second curved segment <NUM> twists as a result of the portion closest to the boundary with third straight segment <NUM> being displaced by an amount that is different from the displacement of the portion closest to second straight segment <NUM>. Stress focuses at the twisting location, causing fatigue of the flexure. By maximizing Wmax1, the structural stiffness of second curved segment <NUM> is maximized, and as a result the twisting motion of the segment is minimized.

Second curved segment <NUM> has a first radius of curvature along an outer edge that is smaller than a second radius of curvature along an inner edge of the second curved segment. Both the rounded bend and the increased width of second curved segment <NUM> serve to reduce the stress experienced by flexure <NUM>, by redistributing the stress on the flexure from higher than average stress areas to lower than average stress areas.

Similarly to the rounded bend of second curved segment <NUM>, the curvature of first curved segment <NUM> also serves to reduce the stress experienced by flexure <NUM>. The width of first curved segment <NUM> has a width labeled Wmin2. Wmin2 can be about <NUM> to about <NUM>, e.g., <NUM>, <NUM>, <NUM>. Moving counterclockwise from Wmax1 to Wmin2, the width of the flexure gradually decreases. Continuing counterclockwise from Wmin2 to the edge of the first arm connector <NUM>, the width of the flexure gradually increases to a width Wmax2, measured at the boundary between first straight segment 711A and first arm connector <NUM>. Wmax2 can be about <NUM> to about <NUM>, e.g., <NUM>, <NUM>, <NUM>.

Referring to <FIG>, a perspective view of flexure <NUM> includes first straight segment 711A connected to a vertical segment <NUM> by first arm connector <NUM>. The perspective view also includes third portion first straight segment 711B connected to vertical portion <NUM> by second arm connector <NUM>. First arm connector <NUM> and second arm connector <NUM> are curved to distribute the stress experienced by these elements across the entirety of their respective curvatures.

During operation of the actuator, the ends of first and second arm connectors <NUM> and <NUM> that are closest to first straight segments 711A and 711B experience a greater displacement in the Z-direction compared to the ends that are closest to the vertical segment <NUM>, due to bending of the second and first arm connectors. By virtue of their positions, first and second arm connectors <NUM> and <NUM> experience greater stress than the average stress experienced by flexure <NUM>. To reduce the likelihood of first and second arm connectors <NUM> and <NUM> failing due to stress, the width of the connectors increases from a width Wmin3, measured at the boundary between the first or second arm connectors and vertical segment <NUM>, to the width Wmax2. Wmin3 can be about <NUM> to about <NUM>, e.g., <NUM>, <NUM>, <NUM>.

In general, the disclosed actuators are controlled by an electronic control module, e.g., electronic control module <NUM> in <FIG> above. In general, electronic control modules are 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 deliver signal waveforms that cause actuator <NUM> to provide a suitable haptic response. Referring to <FIG>, an exemplary electronic control module <NUM> of a mobile device, such as mobile phone <NUM>, includes a processor <NUM>, memory <NUM>, a display driver <NUM>, a signal generator <NUM>, an input/output (I/O) module <NUM>, and a network/communications module <NUM>. These components are in electrical communication with one another (e.g., via a signal bus <NUM>) and with actuator <NUM>.

Processor <NUM> may be implemented as any electronic device capable of processing, receiving, or transmitting data or instructions. For example, processor <NUM> can be a microprocessor, a central processing unit (CPU), an application-specific integrated circuit (ASIC), a digital signal processor (DSP), or combinations of such devices.

Memory <NUM> 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 display driver <NUM>, signal generator <NUM>, one or more components of I/O module <NUM>, one or more communication channels accessible via network/communications module <NUM>, one or more sensors (e.g., biometric sensors, temperature sensors, accelerometers, optical sensors, barometric sensors, moisture sensors and so on), and/or actuator <NUM>.

Signal generator <NUM> is configured to produce AC waveforms of varying amplitudes, frequency, and/or pulse profiles suitable for actuator <NUM> and producing acoustic and/or haptic responses via the actuator. Although depicted as a separate component, in some embodiments, signal generator <NUM> can be part of processor <NUM>. In some embodiments, signal generator <NUM> can include an amplifier, e.g., as an integral or separate component thereof.

Memory <NUM> can store electronic data that can be used by the mobile device. For example, memory <NUM> can store electrical data or content such as, for example, audio and video files, documents and applications, device settings and user preferences, timing and control signals or data for the various modules, data structures or databases, and so on. Memory <NUM> may also store instructions for recreating the various types of waveforms that may be used by signal generator <NUM> to generate signals for actuator <NUM>. Memory <NUM> may be any type of memory such as, for example, random access memory, read-only memory, Flash memory, removable memory, or other types of storage elements, or combinations of such devices.

As briefly discussed above, electronic control module <NUM> may include various input and output components represented in <FIG> as I/O module <NUM>. Although the components of I/O module <NUM> are represented as a single item in <FIG>, the mobile device may include a number of different input components, including buttons, microphones, switches, and dials for accepting user input. In some embodiments, the components of I/O module <NUM> may include one or more touch sensor and/or force sensors. For example, the mobile device's display 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.

Each of the components of I/O module <NUM> may include specialized circuitry for generating signals or data. In some cases, the components may produce or provide feedback for application-specific input that corresponds to a prompt or user interface object presented on the display.

As noted above, network/communications module <NUM> includes one or more communication channels. These communication channels can include one or more wireless interfaces that provide communications between processor <NUM> and an external device or other electronic device. In general, the communication channels may be configured to transmit and receive data and/or signals that may be interpreted by instructions executed on processor <NUM>. In some cases, the external device is part of an external communication network that is configured to exchange data with other devices. Generally, the wireless interface may include, without limitation, radio frequency, optical, acoustic, and/or magnetic signals and may be configured to operate over 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 communications interfaces, or any conventional communication interfaces.

In some implementations, one or more of the communication channels of network/communications module <NUM> may include a wireless communication channel between the mobile device and another device, such as another mobile phone, tablet, computer, or the like. In some cases, output, audio output, haptic output or visual display elements may be transmitted directly to the other device for output. For example, an audible alert or visual warning may be transmitted from the electronic device <NUM> to a mobile phone for output on that device and vice versa. Similarly, the network/communications module <NUM> may be configured to receive input provided on another device to control the mobile device. For example, an audible alert, visual notification, or haptic alert (or instructions therefore) may be transmitted from the external device to the mobile device for presentation.

Claim 1:
An actuator (<NUM>), comprising:
a frame (<NUM>) comprising a panel (<NUM>) extending in a plane and a plurality of pillars extending perpendicular from the plane;
a magnetic circuit assembly (<NUM>) comprising a magnet (<NUM>, <NUM>) and a voice coil, the magnet and voice coil (<NUM>) being moveable relative to each other during operation of the actuator in an axial direction along an axis perpendicular to the plane of the panel; and
a plurality of suspension members (530a, 530b, 530c, 530d, <NUM>, <NUM>) attaching the frame to a first component of the magnetic circuit assembly, each suspension member comprising:
a vertical segment (<NUM>, <NUM>) extending in the axial direction attaching the suspension member to a corresponding one of the pillars;
a first arm (<NUM>, 711A) extending away from the corresponding pillar in a first plane parallel to the panel's plane to an end (613A, <NUM>) attached to the first component of the magnetic circuit assembly; and
a second arm (<NUM>, 711B) extending away from the corresponding pillar in a second plane to an end attached to the first component of the magnetic circuit assembly, the second plane being parallel to the first plane and offset from the first plane in the axial direction, wherein the first arm of the suspension member is able to flex to accommodate axial displacements along the axial direction of the magnet relative to the voice coil.