Patent ID: 12254136

Broadly speaking, embodiments of the present techniques provide haptic button assemblies in which the haptic button has a low profile while still providing a satisfying tactile response or sensation to a user. Advantageously, the haptic button assemblies may have a profile that, for example, enables the assembly to be incorporated into the free space along an edge of a portable computing device.

The haptic assemblies may, for example, be arranged to move the button perpendicularly with respect to the edge of the device (instead of laterally along the edge of the device).

It is possible to generate a haptic sensation from a button or movable portion by moving the button in a lateral direction with respect to the contact by the user—see, for example, WO2018/046937 and GB2551657. However, it may be preferable that a haptic button moves in a direction that is normal to the surface of the button and the surface of a device in which the button is incorporated. This is because a disadvantage of a haptic button that moves laterally is that it requires a large gap between the moving button and the edges of the housing which houses the button to allow lateral motion of the button, but the large gap means it is more difficult to make the haptic button water proof and dust proof in an energy efficient manner. Thus, a haptic button which is easier to make water and dust proof is desirable. It is also desirable to provide a haptic button which does not have a large visible gap (e.g. of the order of 250 μm for a laterally moving button) between the button and the housing, as a smaller gap (e.g. of the order of 50 μm or less) is more aesthetically pleasing.

Furthermore, due to the pressures on size and layout associated with many consumer electronics devices such as wearables, watches and mobile phones, it is also desirable that the haptic button assembly has a low profile.

The present techniques provide haptic button assemblies which have both a low profile (such that they may be more readily incorporated into consumer electronics devices such as smartphones), and may be water and dust proof.

Furthermore, the present techniques provide a local haptic sensation caused by a direct impulse, rather than through inertial effects. For example, smartphones comprise inertial haptic actuators—a mass is moved when a haptic effect is required. Movement of the mass causes the whole smartphone to shake or vibrate. Thus, the haptic effect is general and is not localised. The present techniques provide a localised haptic feedback. Further still, the haptic feedback provided by the present techniques may be customisable by a user by modifying software parameters. This allows different types of haptic feedback to be provided for different purposes or to suit different users.

The term “bearing” is used interchangeably herein with the terms “sliding bearing”, “plain bearing”, “rolling bearing”, “ball bearing”, “flexure”, and “roller bearing”. The term “bearing” is used herein to generally mean any element or combination of elements that functions to constrain motion to only the desired motion and reduce friction between moving parts. The term “sliding bearing” is used to mean a bearing in which a bearing element slides on a bearing surface, and includes a “plain bearing”. The term “rolling bearing” is used to mean a bearing in which a rolling bearing element, for example a ball or roller, rolls on a bearing surface. The bearing may be provided on, or may comprise, non-linear bearing surfaces. In some embodiments of the present techniques, more than one type of bearing element may be used in combination to provide the bearing functionality. Accordingly, the term “bearing” used herein includes any combination of, for example, plain bearings, ball bearings, roller bearings and flexures. In embodiments, a suspension system may be used to suspend the intermediate moveable element and/or the button within the haptic button assembly and to constrain motion to only the desired motion. For example, a suspension system of the type described in WO2011/104518 may be used. Thus, it will be understood that the term “bearing” used herein also means “suspension system”. The bearing may be formed from any suitable material, e.g. ceramic, a metal, a metal alloy, steel, stainless steel, mild steel, bearing bronze, phosphor bronze, plastic, and polytetrafluoroethylene (PTFE). The bearing may be coated with a friction-reducing or low-friction coating such as a lubricant, a dry film lubricant, a diamond-like coating (DLC), a vapour-deposited coating, and hard chrome. The bearing, or a surface that contacts the bearing, may be polished.

Each of the haptic button assemblies described herein may be incorporated into any device in which it may be useful to provide a user of the device with haptic feedback. For example, the haptic button assemblies may be incorporated into an electronic device or a consumer electronics device, such as a computer, laptop, portable computing device, smartphone, computer keyboard, gaming system, portable gaming device, gaming equipment/accessory (e.g. controllers, wearable controllers, etc.), medical device, user input device, etc. It will be understood that this is a non-limiting, non-exhaustive list of possible devices, which may incorporate any of the haptic button assemblies described herein. The haptic button assemblies described herein may be, for example, incorporated into or otherwise provided along an edge of a smartphone or on a surface of a smartphone. In embodiments, the haptic button assemblies described herein may be provided as standalone modules that may be incorporated into an electronic device during manufacture, and may be adapted to suit the device specifications such that it fits into a casing or external surface of the electronic device. In alternative embodiments, some or all of the components of the haptic button assemblies described herein may be integrally formed in an electronic device. For example, the housing, button and/or seal of each haptic button assembly may be part of the electronic device itself. Each haptic button assembly may comprise electrical connections, which may couple the assembly to the device's processor(s), chip(s), motherboard, etc., such that the action of the button of the assembly being pressed may be processed by the device and so that the haptic feedback can be provided.

Various haptic button assemblies are now described with respect to the Figures. It will be understood that elements or features described with respect to one particular Figure or haptic button assembly may equally apply to any of the Figures or haptic button assemblies described herein. For example, the techniques for sealing a haptic button assembly or the different possible SMA actuator wire arrangements described with respect to particular Figures, may apply equally to any or all of the haptic button assemblies described herein

The Intermediate Moveable Element

FIG.1shows a cross-sectional view of a first arrangement of a haptic button assembly100. The haptic button assembly100comprises a button102. The button102may be pressed by a user to perform a particular operation, such as making a selection, turning a device on/off, entering data (e.g. typing on a keyboard), scrolling, turning a function of the device in which the assembly100is located on/off or adjusting the function (e.g. adjusting volume of audio output from the device), etc. Pressing or unpressing (depressing) the button102may cause haptic feedback or a haptic sensation to be delivered to the user, so that the user is provided with some sensory feedback (particularly touch-based feedback) to indicate that the operation has been performed.

In many of the arrangements and embodiments described herein, the button102may be a surface feature on a device/apparatus that incorporates the haptic button assembly. In this case, the haptic button102may not be pressed by a user but may still be able to provide haptic feedback. Instead of a button press triggering haptic feedback, the haptic feedback may be triggered by software in response to another event. For example, if a user makes a selection on a screen of their smartphone, the selection may cause haptic feedback to be triggered, where the feedback is provided by the button or surface feature. (Software-triggered haptic feedback may occur in particular applications, such as in gaming and/or virtual/augmented reality devices). Thus, in many of the arrangements and embodiments described herein, direct pressing of the haptic button102may not be required in order for haptic feedback to be delivered. However, in each case, the mechanism to deliver the haptic feedback is broadly the same whether or not button itself is pressed.

In embodiments, such as that shown inFIG.1, the haptic button assembly100may comprise a housing104(also referred to herein as “support”, “chassis”, “casework”, and “casing”). The housing104may comprise a cavity or recess112. The button102may be provided within the cavity112of the housing104. The button102comprises a contact surface106(also referred to herein as an outer surface, external surface or upper surface). In embodiments, the button102may be arranged within the cavity112such that the contact surface106is substantially level with/flush with an external surface108of the housing104. However, in embodiments, the button102may protrude from the external surface108of the housing104. It will be understood that the housing104surrounds and encases the button102, such that only the contact surface106of the button is visible/contactable by a user.

The haptic button assembly100may comprise an intermediate, movable element110, which may be provided within the cavity112below the button102. Button102may be arranged to move (when pressed/depressed by a user) in a first direction. The first direction may be a direction that is perpendicular to the external surface108of housing104, as indicated by arrow116inFIG.1. In other words, contact of a user's finger with the contact surface106of button102, for example, may cause the button102to move into the housing104or further into cavity112. In particular embodiments, the button102may move into the cavity112by 100 μm. The haptic button assembly100may comprise a sensor (not shown) in the housing104below the button and intermediate moveable element110. The sensor may be a force sensor, for example. Generally speaking, the sensor may be any suitable sensor or mechanism for detecting depression of the button102by a user (i.e. detecting that a user has pressed the button102). The movement of the button102into the cavity112(as a result of the user pressing the button102) causes a force to be exerted on the sensor. The sensor may be coupled to control circuitry (not shown), and the sensor may be configured to communicate with the control circuitry when the force on the sensor changes, or when the force on the sensor has been applied for a minimum duration. The detection by the sensor of a user pressing the button causes the haptic feedback to be generated and applied by haptic button assembly100.

Moveable element110may be able to move in a second direction within the cavity112. The second direction is different to the first direction. The second direction may be a direction that is substantially parallel to the external surface108of casing104, as indicated by arrow118inFIG.1. That is, moveable element110may move in a sideways (or lateral) direction within the housing104(or within the recess112of the housing104). Thus, the first direction and the second direction may be orthogonal. Movement of the intermediate moveable element110in the second direction may cause movement of the button102in the first direction. That is, movement of the intermediate moveable element110may cause the button102to be moved in such away that a haptic effect/sensation is delivered to a user touching the button102. The concept of moving intermediate moveable element110in one direction to cause movement of button102in another direction may be implemented in a number of ways.

For example, in embodiments such as that shown inFIG.1, both the button102and the moveable element110may be wedge-shaped, and arranged within the cavity112such that a wider end of the wedge-shaped button102is in proximity to a narrower end of the wedge-shaped moveable element110. Thus, a narrower end of the wedge-shaped button102is in proximity to a wider end of the wedge-shaped moveable element110. This arrangement of the wedge-shaped button102and moveable element110means that when the moveable element110is caused to move within the casing104in the second direction118, the button102will be forced to move in the first direction116. In this embodiment, the intermediate moveable element110is a ‘single wedge’, as only one surface of the element is sloped/inclined.

The movement of moveable element110is now described. The haptic button assembly100may comprise at least one shape memory alloy (SMA) actuator wire120. The at least one SMA actuator wire120may be provided within a further cavity112ain housing104. The further cavity112amay be smaller than the cavity112but may be large enough for the intermediate moveable element110to at least partly fit into. The SMA actuator wire120may be coupled at one end122to the housing104(and specifically to the further cavity112a) and at another end124to the intermediate moveable element110. Thus, in embodiments, the intermediate movable element110may be formed of a material that is suitable for coupling to (e.g. crimping) an SMA actuator wire, such as a suitable metallic material. Alternatively, the intermediate moveable element110may be formed of any material, and crimp components may be fixedly attached to the intermediate moveable element110, to crimp an end of the SMA actuator wire. Generally speaking, a coupling element may be used to couple each SMA actuator wire120to the housing104(i.e. the static component) and to the intermediate moveable element110. The coupling element may provide a permanent (i.e. fixed) connection between the SMA wires and the static component or the moveable component. The coupling element may be a crimp connector, a welded component that is welded to each SMA actuator wire to form a weld, or other similar connectors. A coupling element (e.g. crimp connector or welded component) may hold multiple SMA actuator wires or may hold a single SMA actuator wire, as described in United Kingdom Patent Application No. GB1820042.8 to the present applicant.

Thus, each SMA actuator wire may be coupled to the at least one intermediate moveable element via a coupling element. The coupling element may be a crimp connector, a welded component, or a non-fixed connector.

As an alternative to crimping, the ends of each SMA actuator wire120may be connected in place using welding (e.g. arc welding, welding using a weld bar, laser/heat-based welding, etc.). During the welding process, care needs to be taken to control the welding so that damage to the SMA actuator wire, e.g. melting or loss of material, is minimised.

The coupling element may alternatively comprise a connector which provides a non-fixed connection between the SMA actuator wire and the intermediate moveable component or static component. Such a non-fixed connector may be in the form of a protruding element such as a hook, dowel pin or similar element around which the SMA wires are looped or similarly held in place. For example, a length of SMA actuator wire may wrap around/be provided around a dowel pin (see e.g.FIG.9D) on the intermediate moveable element, and the ends of the SMA actuator wire may be attached to the housing via crimps. Alternatively, a length of SMA actuator wire may be attached to the intermediate moveable element and wrap around a pin-like feature or dowel on the static portion/housing.

When a button press is detected by the sensor, this detection is communicated to control circuitry (not shown). The control circuitry may be arranged to control power delivered to the at least one SMA actuator wire120. Power may be delivered to the at least one SMA actuator wire. When the SMA actuator wire120is powered, it becomes hot and contracts. The contraction of the SMA actuator wire120causes the intermediate moveable element110to move laterally/sideways within the cavity112, and towards (and in embodiments, at least partly into) the further cavity112a. In the illustrated arrangement, the intermediate moveable element110moves towards the left of the Figure. As the intermediate moveable element110moves sideways towards/into the further cavity112a, the wedge-shape of the moveable element110forces the button102to move within cavity112. In the illustrated arrangement, the button102moves upwards in/towards the top of the Figure. The intermediate moveable element110may cause the button102to move by, for example, between 20 μm to 0.5 mm. In embodiments, the button102may move by up to 1 mm.

Generally speaking, it will be understood that the button102and intermediate moveable element110could be shaped such that the button moves into the cavity112when the SMA actuator wire120is powered and caused to contract. Thus, in each embodiment described herein, the button102may move into the cavity in order to deliver haptic feedback. (The types of haptic feedback deliverable when the button moves into the cavity may be the same as or different to the types of feedback deliverable when the button moves outwards of the cavity).

The haptic button assembly100may comprise an element which opposes the force of the at least one SMA actuator wire120. For example, the haptic button assembly100may comprise a return spring126. The return spring126may be provided within the further cavity112aand may be coupled at one end to the housing104and at another end to the intermediate moveable element110. The return spring126may be arranged to oppose the contraction of the at least one SMA actuator wire120(which caused the moveable element110to move in one direction), and thereby move the intermediate moveable element110in an opposite direction, i.e. away from the further cavity112a. In the Figure, the return spring126may cause the intermediate moveable element110to move to the right when the wire is not being powered and is not being actively heated (i.e. is cooling). The element which opposes the force of the at least one SMA actuator wire120may be any suitable resilient biasing element, and it will be understood that the return spring is only one non-limiting example. In embodiments, a further SMA actuator wire may be used to oppose the force of the SMA actuator wire120. This may be arranged to, on contraction, pull the intermediate moveable element in the opposite direction to the movement caused by the SMA actuator wire120. The further SMA actuator wire may be provided between the housing104and the opposite side of the intermediate moveable element110(opposite to the side to which SMA actuator wire120is attached). In this embodiment, the at least one SMA actuator wire120and the return spring126may be considered to form an actuator which causes movement of the intermediate moveable element110(also referred to herein as a “moving portion”) in the housing104(also referred to herein as a “static portion”).

In alternative embodiments, a return spring or further SMA actuator wire may not be used. Instead, the force of a user's finger on the button102may be sufficient to oppose the contraction of the at least one SMA actuator wire120and thereby move the intermediate moveable element away from the further cavity112a.

In embodiments, a system of opposing SMA actuator wires may be used to customise the haptic feedback delivered when a user presses the button102. For example, the system of opposing wires may allow different types of haptic feedback to be provided depending on what the sensor of the assembly100detects/senses. For example, where the sensor is a force sensor, the haptic feedback may be customised based on the magnitude of the force detected by the sensor—a high contact force may cause a particular type of haptic feedback to be delivered while a low contact force may cause a different type of haptic feedback to be delivered. The feedback delivered may be adjusted by having an arrangement of opposing SMA actuator wires that allows the movement (e.g. speed, direction, etc.) of the intermediate moveable element110to be finely controlled. In embodiments, the SMA actuator wire(s) may themselves be part of the sensor mechanism of the assembly, by measuring the resistance of the SMA actuator wires to determine e.g. the contact force.

The haptic button assembly100may comprise one or more bearings to reduce friction between the moving parts of the assembly. For example, the haptic button assembly100may comprise a first bearing130between the button102and the intermediate moveable element110. The first bearing130may comprise one or more ball bearings128that are provided between surface134of the button102and surface136of the intermediate moveable element110. Surfaces134and136are ramped (inclined) so that when the SMA actuator wire120contracts and moves the moveable element laterally, the button102is forced to move within cavity112(i.e. orthogonal to the movement of the moveable element110). Surfaces134and136are inclined by the same angle and in the same direction. Specifically, the direction in which the surfaces134,136are inclined is chosen so that movement of the intermediate moveable element110towards the further cavity112apushes the button102upwards in the cavity112, i.e. such that contact surface106may protrude from the housing104(and may not be flush with surface108of the housing104). First bearing130may comprise the inclined (ramped) mating surfaces134and136and one or more ball bearings128. For example, bearing130may comprise three ball bearings128, but this is a non-limiting example. The haptic button assembly100may comprise a second bearing132between the intermediate moveable element110and a surface of the housing104(i.e. a surface of the cavity112). The second bearing132may comprise one or more ball bearings128provided between surface138of the intermediate moveable element110and surface140of the housing104(i.e. a surface of the cavity112), which may facilitate the lateral movement of the movable element110. The horizontal movement of the movable element110causes the button102to move up and down (as indicated by the double-headed arrows) to provide the tactile effect to the user's finger.

The haptic button assembly100may comprise an endstop114in cavity112. The endstop114may be formed as part of the housing104or cavity112, or may be a separate element that is provided in cavity112. The endstop114may be provided at a location in the cavity112to restrict movement of the intermediate moveable element110. Generally speaking, if SMA actuator wire is stretched too far (i.e. a certain tension is exceeded), the SMA actuator wire may weaken or become damaged, or even break. The force of the return spring126on the intermediate moveable element110may cause the SMA actuator wire120to become overstretched. Therefore, the endstop114may restrict the movement of the intermediate moveable element110so that the at least one SMA actuator wire120does not overstretch. Similarly, a force applied to the button surface by the user's finger may cause the wire to overstretch if there is no endstop.

Accordingly, the present techniques provide a haptic button assembly comprising: a housing comprising a cavity; a button provided within the cavity and moveable along a first axis within the cavity; at least one intermediate moveable element provided within the cavity in contact with the button and moveable in a plane defined by the first axis and a second axis, the second axis being perpendicular to the first axis, and arranged to drive movement of the button along the first axis; and at least one shape memory alloy (SMA) actuator wire coupled to the at least one intermediate moveable element and arranged to, on contraction, move the intermediate moveable element in the plane.

FIG.2shows a cross-sectional view of a second arrangement of a haptic button assembly200. The haptic button assembly200inFIG.2is similar to the arrangement shown inFIG.1, and therefore, for the sake of conciseness, like features are not described. In haptic button assembly100, both the button102and the intermediate moveable element110are wedge-shaped. Specifically, the mating surfaces134and136are inclined (ramped). In haptic button assembly200, surfaces234and236are not inclined/ramped. In this embodiment, the intermediate moveable element210is a ‘single wedge’, as only one surface of the element is sloped/inclined. The haptic assembly200may comprise a first bearing230between the button and the intermediate moveable element. The first bearing230may comprise one or more ball bearings that are provided between the surfaces234and236of the button and intermediate moveable element respectively. For example, the first bearing230may comprise three ball bearings, but this is a non-limiting example.

In haptic button assembly100, surfaces138and140of the intermediate moveable element110and the housing104respectively are substantially flat (i.e. are not inclined or ramped). In haptic button assembly200, surface238of the intermediate moveable element is ramped/inclined, and surface240of the housing/cavity is also ramped/inclined. The surfaces238and240are inclined by the same angle and in the same direction, such that the moveable element may, when actuated, slide or move along the surface240and in doing so, push the button upwards in the cavity such that the contact surface of the button protrudes from the housing. As mentioned earlier, in embodiments, the button may move into the cavity when delivering haptic feedback—in this case, the direction of the ramps/inclined surfaces may be reversed. The haptic button assembly200may comprise a second bearing232between the intermediate moveable element and a surface of the housing/surface of the cavity. The second bearing232may comprise one or more ball bearings provided between surface238of the intermediate moveable element and surface240of the housing/cavity, which may facilitate the movement of the intermediate moveable element. The bearing232may comprise three ball bearings, for example. The second bearing232may comprise the ramped/inclined surfaces238,240. In this arrangement, when the at least one SMA actuator wire contracts (as described above with reference toFIG.1), the intermediate moveable element may move laterally (e.g. in the direction of the force exerted by the at least one SMA actuator wire on the moveable element) and in a substantially perpendicular or orthogonal direction. As the moveable element moves along the ramp provided by surface240of the cavity, the moveable element causes the button to move within the cavity (as indicated by arrow216).

FIG.3shows a cross-sectional view of a third arrangement of a haptic button assembly300. The haptic button assembly300inFIG.1is similar to the arrangement shown inFIG.1and therefore, for the sake of conciseness, like features are not described. The haptic button assembly300combines features of assemblies100and200. Specifically, both the button and the intermediate moveable element are wedge-shaped in haptic button assembly300. The haptic button assembly300may comprise one or more bearings to reduce friction between the moving parts of the assembly. For example, the haptic button assembly300may comprise a first bearing330between the button and the intermediate moveable element. The first bearing330may comprise one or more ball bearings that are provided between surface334of the button and surface336of the intermediate moveable element. Surfaces334and336are ramped/inclined so that when the SMA actuator wire contracts and moves the moveable element in the direction of the force applied by the SMA actuator wire, the button is forced to move within the cavity (i.e. substantially orthogonal to the movement of the moveable element). Surfaces334and336are inclined by the same angle and in the same direction. Specifically, the direction in which the surfaces334and336are inclined is chosen so that movement of the intermediate moveable element towards the further cavity112apushes the button upwards in the cavity, such that the contact surface of the button may protrude from the housing. Thus, this is an example of the intermediate moveable element being a ‘double wedge’, as two surfaces of the element are sloped/inclined.

The haptic button assembly300may comprise a second bearing332. In haptic button assembly300, surface338of the intermediate moveable element is ramped/inclined, and surface340of the housing/cavity is also ramped/inclined. The surfaces338,340are inclined by the same angle and in the same direction, such that the moveable element may, when actuated, slide or move along the surface340and in doing so, push the button upwards in the cavity such that the contact surface of the button protrudes from the housing. The second bearing332of the assembly300may be provided between the intermediate moveable element and a surface of the housing/cavity. The second bearing332may comprise one or more ball bearings provided between surface338of the intermediate moveable element and surface340of the housing/cavity, which may facilitate the movement of the intermediate moveable element. The second bearing332may comprise three ball bearings, for example. The second bearing332may comprise the inclined/ramped surfaces338,340. The direction in which surfaces334,336are inclined is opposite to the direction in which surfaces338,340are inclined. The angles or gradients of the pairs of inclined surfaces334,336and338,340may be the same or different—however, the angles/gradients of the surfaces in a pair of inclined surfaces need to be the same. The gradients of the pairs of inclined surfaces/the bearing surfaces may be linear or non-linear. In other words, the bearing surfaces may have a constant gradient or a non-linear gradient. Thus, in embodiments, the at least one ramp/bearing surface may have a constant gradient, or may have a variable, non-constant gradient (which follows any non-linear equation). Thus, in this arrangement, when the at least one SMA actuator wire contracts (as described above with reference toFIG.1), the moveable element may move laterally—causing the button to move upwards as inFIG.1—and in a substantially perpendicular or orthogonal direction—causing the button to move upwards as inFIG.2. Thus, the arrangement ofFIG.3combines two techniques to move the button and deliver a haptic sensation.

FIG.4shows a cross-sectional view of a fourth arrangement of a haptic button assembly400. The haptic button assembly400inFIG.4is similar to the arrangement shown inFIG.1and therefore, for the sake of conciseness, like features are not described. In haptic button assembly100, both the button102and the intermediate moveable element110are wedge-shaped. Specifically, the mating surfaces134and136are inclined/ramped. In haptic button assembly400, surfaces434and436are not entirely inclined/ramped across their full extent. Instead, surfaces434and436are locally ramped. Surface434of the button comprises one or more localised ramps442(as shown more clearly in the inset close-up view of the assembly). Surface436of the intermediate moveable element comprises one or more localised ramps444(as shown more clearly in the inset close-up view of the assembly). The localised ramps442and444are co-located in pairs. In other words, a localised ramp442of the button is in close proximity to a corresponding localised ramp444of the intermediate moveable element. The localised ramps442and444are inclined by the same angle and in the same direction. Where there is more than one pair of localised ramps, all of the ramps may be inclined by the same angle and in the same direction. The direction in which the localised ramps442and444are inclined is chosen so that the movement of the intermediate moveable element towards the further cavity pushes the button upwards in the cavity, i.e. such that the contact surface of the button may protrude from the housing. (It can be seen that the direction of the localised ramps is the same as the direction of the inclined surfaces134,136inFIG.1). In the illustrated example, there are three pairs of localised ramps, but it will be understood that this is a non-limiting example. An advantage of the localised ramps442,444is that they may enable the overall height of the haptic button assembly to be reduced relative to, for example, the arrangement shown inFIG.1, as the surfaces434,436are not ramped across their whole length. In this embodiment, the intermediate moveable element may be considered a ‘single wedge’, as only one surface of the element comprises the localised ramps.

The haptic button assembly400may comprise a first bearing430between the button and the intermediate moveable element. The first bearing430may comprise one or more ball bearings128that are provided between surface434of the button and surface436of the intermediate moveable element. At least one ball bearing128may be provided between the or each pair of localised ramps442,444. As shown inFIG.4, a ball bearing128is provided between each of the three pairs of localised ramps. However, it will be understood that more than one ball bearing128may be provided on each ramp. For example, in embodiments there may be three ball bearings on each localised ramp442,444. The number of ball bearings per localised ramp may depend on whether there are other ways of constraining the motion of the intermediate moveable element and the button (e.g. additional wall contacts or end stops). The first bearing430may comprise one or more localised ramps442,444, and one or more ball bearings128.

The haptic button assembly400may comprise a second bearing432between the intermediate moveable element and a surface of the housing/cavity. The second bearing432may comprise one or more ball bearings provided between surface438of the intermediate moveable element and surface440of the housing (i.e. a surface of the cavity), which may facilitate the lateral movement of the movable element.

It will be understood that the localised ramps shown inFIG.4could be incorporated into any of the arrangements shown inFIGS.1to3, or indeed, any of the embodiments described herein. Generally speaking, the localised ramps may be provided between the button and the intermediate moveable element, and/or between the intermediate moveable element and the housing. This may amplify the amount by which the button is moved when the intermediate moveable element is actuated. The direction and inclination angle of the localised ramps may be chosen to suit each arrangement.

FIG.22shows a cross-sectional view of an alternative arrangement of a haptic button assembly2200. The haptic button assembly2200is similar to the arrangement shown inFIG.4and therefore, for the sake of conciseness, like features are not described. InFIG.22, the location of the localised ramps is changed relative toFIG.4. InFIG.4, surfaces434and436are locally ramped. In comparison, inFIG.22, surfaces438and440are locally ramped and surfaces434and436are not. Surface438of the intermediate moveable element comprises one or more localised ramps442′ (as shown more clearly in the inset close-up view of the assembly). Surface440of the housing (i.e. a surface of the cavity), comprises one or more localised ramps444′ (as shown more clearly in the inset close-up view of the assembly). The localised ramps442′ and444′ are co-located in pairs. In other words, a localised ramp442′ of the intermediate moveable element is in close proximity to a corresponding localised ramp444′ of the housing. The localised ramps442′ and444′ are inclined by the same angle and in the same direction. Where there is more than one pair of localised ramps, all of the ramps may be inclined by the same angle and in the same direction. The direction in which the localised ramps442′ and444′ are inclined is chosen so that the movement of the intermediate moveable element towards the further cavity pushes the button upwards in the cavity, i.e. such that the contact surface of the button may protrude from the housing. However, it will be understood that if the direction of incline of the localised ramps are reversed, the button could move into the cavity/housing. In the illustrated example, there are three pairs of localised ramps, but it will be understood that this is a non-limiting example. An advantage of the localised ramps442′,444′ is that they may enable the overall height of the haptic button assembly to be reduced relative to, for example, the arrangement shown inFIG.1, as the surfaces438,440are not ramped across their whole length. In this embodiment, the intermediate moveable element may be considered a ‘single wedge’, as only one surface of the element comprises the localised ramps.

An advantage of this embodiment relative to that shown inFIG.4is simplified manufacturing. In the case of smartphones, typically the button may be manufactured and inserted into a smartphone handset by one manufacturer, and the haptic button assembly may be inserted into the smartphone handset by another manufacturer. In the embodiments shown inFIGS.1,3, and4to6, for example, the button may need to be specially designed, shaped or milled, either to have inclined surfaces or localised ramps. However, the embodiment shown inFIG.22may simplify the manufacturing process as the button does not need to be specially designed. Instead, the intermediate moveable element and the housing are shaped to comprise the localised ramps, but these are typically manufactured by the same manufacturer. This may mean that any button can be used alongside the haptic button assembly2200, which simplifies the design of the haptic button assembly and removes any requirement for the manufacturer of the smartphone handset to shape the handset in a particular way or provide a particular type of button.

FIG.22shows a haptic button assembly2200in which there is a gap between the button and the housing. In this case, as described herein, it may be necessary to incorporate a sealing mechanism to prevent or minimise liquid and/or dirt ingress into the assembly via the gap. However, it will be understood that the haptic button assembly2200may be arranged as a gapless haptic assembly, i.e. one in which there is no gap between the button and the housing. For example, the button (i.e. the element which is used to deliver haptic feedback) may be integrated into the housing, as shown inFIG.25.

The haptic button assembly2200may comprise a first bearing430′ between the button and the intermediate moveable element. The first bearing430′ may comprise one or more ball bearings128that are provided between surface434of the button and surface436of the intermediate moveable element, which may facilitate the lateral movement of the movable element.

The haptic button assembly2200may comprise a second bearing432′ between the intermediate moveable element and a surface of the housing/cavity. The second bearing432′ may comprise one or more ball bearings128that are provided between surface438of the intermediate moveable element and surface440of the housing (i.e. a surface of the cavity). A ball bearing128may be provided between the or each pair of localised ramps442′,444′. As shown inFIG.22, a ball bearing128is provided between each of the three pairs of localised ramps. The second bearing432′ may comprise one or more localised ramps442′,444′, and one or more ball bearings128.

It will be understood that the localised ramps shown inFIG.22could be incorporated into any of the arrangements shown inFIGS.1to3, or indeed, any of the embodiments described herein. Furthermore, the localised ramps shown inFIG.22could be used in addition to or instead of the localised ramps of the arrangements ofFIGS.4to6. Generally speaking, the localised ramps may be provided between the button and the intermediate moveable element, and/or between the intermediate moveable element and the housing. This may amplify the amount by which the button is moved when the intermediate moveable element is actuated. The direction and inclination angle of the localised ramps may be chosen to suit each arrangement.

Thus, in embodiments, the haptic button assembly may further comprise a bearing provided between the intermediate moveable element and a base of the cavity and arranged to bear movement of the intermediate moveable element along the second axis. The second bearing of the haptic button assembly may comprise at least one ramp and at least one ball bearing arranged to roll along the at least one ramp. The at least one ramp may be provided by an inclined surface of the intermediate moveable element and/or a base surface of the cavity. The at least one ramp may be a localised ramp provided on a surface of the intermediate moveable element and/or on the base surface of the cavity.

Turning now toFIG.7, this shows a cross-sectional view of a seventh arrangement of a haptic button assembly700. The haptic button assembly700is similar to the arrangement shown inFIG.1and therefore, for the sake of conciseness, like features are not described. In haptic button assembly700, button702is wedge-shaped and intermediate moveable element710is also wedge-shaped. The button702and intermediate moveable element710are arranged within the cavity such that a wider end of the wedge-shaped button702is in proximity to a narrower end of the wedge-shaped moveable element710, and a narrower end of the wedge-shaped button702is in proximity to a wider end of the wedge-shaped moveable element710. InFIG.1, movement of the intermediate moveable element710towards/into the further cavity112acaused the button102to be pushed upwards in the cavity112such that the button102may protrude from the housing108. In contrast, the haptic button assembly causes the button702to move downwards, i.e. further down into the cavity when the moveable element710moves into/towards the further cavity. This is achieved by changing (reversing) the direction of the inclined surfaces relative to the arrangement ofFIG.1. Specifically, surface734of the button702and surface736of the intermediate moveable element710are inclined in the opposite direction to surfaces134and136ofFIG.1. Thus, movement of the intermediate moveable element710towards the further cavity enables the button702to drop or move downwards in the cavity (i.e. move towards a base of the cavity). In this embodiment, the intermediate moveable element710may be considered a ‘single wedge’, as only one surface of the element is inclined/sloped.

An advantage of the arrangement ofFIG.7may be that the motion of the button702into the cavity is assisted by any pressure that a user applies to the button702(rather than resisting the motion when the button moves upwards). Furthermore, the effect of the button dropping away from a user's finger may be another type of haptic feedback. It also means that if the button is prevented from moving, the wire will not reach very high tensions and so run the risk of being damaged. For example, inFIG.1, if the button102were prevented from moving upwards/vertically/out of the cavity (by e.g. a user pushing down on the button with excessive force), the SMA actuator wire will not be able to contract even though it is being powered—this may cause the SMA actuator wire to reach a high tension that may lead to damage. However, inFIG.7, if the button702were prevented from moving, the intermediate moveable element710is still able to move as the SMA actuator wire contracts, thereby avoiding potential damage to the wire.

It will be understood that the “reverse wedge” arrangement shown inFIG.7may be combined with any of the techniques described with reference to any of the preceding arrangements ofFIGS.1to6.

FIG.8shows a cross-sectional view of an eighth arrangement of a haptic button assembly800. The haptic button assembly800is similar to the arrangement shown inFIGS.1and6and therefore, for the sake of conciseness, like features are not described. The haptic button assembly comprises a button802and an intermediate moveable element810. The button802is similar to button602inFIG.6. Button802comprises a protrusion846which forms the contact point or contact surface of button802. As perFIG.6, here there is a large gap between the button802and protective seal842, which may enable the protective seal842to flex/bend in such a way that the seal does not restrict the motion of the button802. The button802comprises one or more localised ramps along surface834(i.e. the surface which comes into contact with the intermediate moveable element810). Thus, the intermediate moveable element810may be considered a ‘single wedge’, as only one surface of the element comprises the localised ramps.

The intermediate moveable element810may be formed from a sheet of material which may be etched to form one or more localised ramps. The or each localised ramp may be formed by etching a tab-like element in the sheet of material and folding the tab by the required angle and in the required direction to create a ramp. In the illustrated arrangement, the intermediate moveable element810comprises two localised ramps810b,810cformed from two tabs in the sheet of material, but this is a non-limiting example. Two opposite ends of the sheet of material may be folded in the same direction to form edges810aand810dof the intermediate moveable element810. Edge810ais coupled to the at least one SMA actuator wire and, if present, may be coupled to a return spring (or similar component). Edge810dmay, in combination with endstop814, function to limit the range of motion of the intermediate moveable element810. The button802and intermediate moveable element810may comprise the same number of localised ramps. The localised ramps of the button802and intermediate moveable element810may be co-located in pairs. In other words, a localised ramp of the button may be in close proximity to a corresponding localised ramp of the intermediate moveable element810. The intermediate moveable element810may, in embodiments, be formed from a thin sheet of metal which may be relatively rigid (such that, in use, the localised ramps do not flex or bend). For example, the intermediate moveable element810may be formed from a sheet of phosphor bronze. In embodiments, the tab-like elements may be formed by plastic deformation of the sheet of material into a well or pocket, to thereby improve the rigidity of the sheet of metal which forms the intermediate moveable element. In embodiments, rib-like features may be provided on the intermediate moveable element810to further stiffen the metal sheet where required.

The haptic button assembly800may comprise a first bearing830between the button802and the intermediate moveable element810. The first bearing830may comprise one or more ball bearings128that are provided between surface834of the button and surface836of the intermediate moveable element. At least one ball bearing128may be provided between the or each pair of localised ramps. The first bearing830may comprise one or more localised ramps and one or more ball bearings. It will be understood that more than one ball bearing128may be provided between each pair of localised ramps. For example, in embodiments there may be three ball bearings on each localised ramp.

The haptic button assembly800may comprise a second bearing832between the intermediate moveable element810and a surface of the housing/cavity. The second bearing832may comprise one or more ball bearings provided between surface838of the intermediate moveable element and surface840of the housing (i.e. a surface of the cavity), which may facilitate the lateral movement of the moveable element.

The button802may comprise a clearance nick or cut838at a corner of the button which interacts with edge810dof the intermediate moveable element810. The clearance cut838may be provided so that edge810dmay be able move freely when the intermediate moveable element810is actuated.

The overall height of the intermediate moveable element810may be similar to the height of the moveable element in, for exampleFIG.6, or may be lower. Furthermore, less material may be used to form the intermediate moveable element810compared to, for example,FIG.6. Therefore, the arrangement ofFIG.8may advantageously enable a lower height/smaller size haptic button assembly to be provided and/or may provide a lower cost assembly (as less material is used).

FIG.9Ashows a cross-sectional view of a ninth arrangement of a haptic button assembly900. The haptic button assembly900is similar to the arrangement shown inFIG.1and therefore, for the sake of conciseness, like features are not described. Button902of the haptic button assembly900may comprise a lip916that protrudes from a side or along at least a part of the button902(providing a ‘local’ endstop). The lip916may be provided all the way around the button if the lip also acts as a sealing mechanism. The housing904may comprise a corresponding ledge or groove914, and the lip916of the button may engage with the ledge914of the housing904. The ledge914may, for example, restrict the movement of the button902into the cavity of the housing904. The lip916therefore functions as an endstop to restrict the motion of the button902in one direction. If the button902is pressed with excessive force, the lip916comes into contact with the ledge914, and the force is transmitted into the housing904through this contact, instead of passing through the bearings which could potentially cause damage to the bearings. Furthermore, the lip916may perform a sealing function when the button is pressed. For example, if the lip916of the button902has the form of an O-ring, the lip916may provide sealing of the assembly900against water and dust ingress when the button is in its equilibrium position.

FIG.10Ashows a cross-sectional view of a tenth arrangement of a haptic button assembly1000, andFIG.10Bshows a zoomed-in view of a portion on the tenth arrangement. Generally speaking, it may be useful to constrain the motion of the button within the cavity of a haptic button assembly such that it only moves up and down within the cavity (i.e. along a first axis A) and not side-to-side/laterally (i.e. not along a second axis B). In embodiments, a bearing may be provided between the button and the cavity/housing to restrict the motion along the second axis B. Alternatively, if the assembly comprises one or more flexures, the flexures may restrict the motion of the button along the second axis B. The intermediate moveable element moves along the second axis B and may in some embodiments also move along the first axis A. The motion of the button along axis B may be restricted in a variety of ways. For example, a surface of the button and a surface of the housing (i.e. an inner surface of the cavity) may be in contact such that they operate as a plain bearing. Alternatively, one or more ball bearings may be provided between the button and the cavity, and/or one or more flexures may be provided between the button and the cavity/housing to constrain lateral motion of the button (i.e. motion along axis A). In embodiments, the protective membrane (described above) may act as a flexure that constrains the lateral motion of the button. The protective membrane/flexure is stiff and able to absorb the moment induced in it by the intermediate moveable element.

The haptic button assembly1000is similar to the arrangement shown inFIG.8and therefore, for the sake of conciseness, like features are not described. Haptic button assembly1000comprises at least one ball bearing1028provided between button1002and housing1004(i.e. an inner surface of the cavity of the housing), which may accept/absorb any sideways/lateral force that is transferred from intermediate moveable element1012to the button1002. The ball bearing(s) between the button1002and the housing1004may be sufficient to restrict motion of the button1002along axis B.

Additionally or alternatively, the haptic button assembly1000may comprise means for restricting the amount of lateral motion of intermediate moveable element1012. By restricting the extent of lateral motion that the intermediate moveable element1012can undergo (i.e. motion along axis B), the lateral motion of the button1002may also be restricted. The means for restricting the lateral motion of intermediate moveable element1012may be or comprise a spacing component1050, provided between the intermediate moveable element1012and the housing1004. The spacing component1050may be formed of a sheet or layer of material. The spacing component1050may comprise one or more holes1054. Each hole1054may be a through-hole or a blind hole. The intermediate moveable element1012may comprise one or more localised ramps1056, which correspond to the localised ramp(s) of the button1002, as described above with reference toFIG.8. The or each localised ramp1056may be arranged to sit within (locate within) the holes1054in the spacing component1050. The spacing component1050may therefore restrict the motion of the intermediate moveable element1012because the hole1054constrains the motion of the localised ramp1056that is located in the hole.

Where the intermediate moveable element1012comprises multiple localised ramps1056, at least one ball bearing may be provided between the ramps1056to reduce friction between the unramped portions of the intermediate movable element1012and the spacing component1050. In the embodiment shown inFIG.10B, the intermediate moveable element1012comprises two localised ramps1056. Ball bearing1028′ is provided between the unramped portion of the intermediate movable element1012and the housing1004. Ball bearing1028′ is located in a hole1054in the spacing component1050to keep this ball in the correct location.

As mentioned earlier with reference toFIG.1, each haptic button assembly may comprise a sensor to detect when a user is pressing the button.FIGS.10A and10Bshow a sensor1052for detecting when a user is pressing the button1002. The sensor1052is provided between the spacing component1050and the housing1004. The sensor1052may be a contact sensor and may comprise a deformable surface1058. Thus, when button1002is pressed, the downward force on the button is transferred to the intermediate moveable element1012and the spacing component1050, which causes the deformable surface1058to deform and make an electrical contact with conductive surface1060of the sensor1052. This type of sensor may be provided in any of the haptic button assemblies described above with reference toFIGS.1to9C. An example mechanism to detect a press of a button is described in GB2551657, which is hereby incorporated by reference in its entirety.

FIG.16shows a cross-sectional view of a thirteenth haptic button assembly1600. The haptic button assembly1600comprises a button1602and a housing1604. In this case, the button1602is part of the housing1604. The housing1604may comprise at least a portion which is flexible and pressable and therefore provides the button1602of the assembly1600. Advantageously, by forming the button1602as part of the housing1604, there is no gap between the button and the housing and therefore, a sealing mechanism is not required. This may also provide a cheaper and simpler assembly to manufacture.

The assembly1600comprises an intermediate moveable element1606, which takes the form of a lever arm. The intermediate moveable element1606may be coupled to a first SMA actuator wire1608to move the lever arm in a first direction, and may be coupled to a second SMA actuator wire1610to move the lever arm in a second direction. Alternatively, one of the actuator wires1608,1610may be replaced by a return spring or similar resilient element. Further alternatively, the flexible portion of the housing1604may itself be stiff enough to provide a return force—in this case, a return spring or second SMA actuator wire may not be required. Movement of the intermediate moveable element1606may cause the button portion1602of the housing1604to flex. Thus, the housing1604may be formed of a flexible material such that when the intermediate moveable element1606is actuated, the button portion1602flexes and provides a haptic sensation. Alternatively, the housing1604may be formed of a material which is not generally flexible unless it is provided as a thin layer. Thus, the button1602may be thinner than the rest of the housing1604such that the button portion is flexible. For example, at least the button1604may be formed from a thin layer of metal, e.g. a 50 μm thick layer of aluminium.

FIG.16Ashows a cross-sectional view of a further haptic button assembly1650comprising a lever arm1656. The haptic button assembly1650comprises a button or button portion1652and a housing1654. In this case, the button1652is part of the housing1654. The housing1604may comprise at least a portion which is flexible and pressable and therefore provides the button1652of the assembly1650. Advantageously, by forming the button1652as part of the housing1654, there is no gap between the button and the housing and therefore, a sealing mechanism is not required. This may also provide a cheaper and simpler assembly to manufacture. However, it will be understood that the haptic button assembly1650may be arranged such that there is a gap between the button1652and the housing1654(e.g. as shown inFIG.24), or such that there is a separate button component which is not part of the housing (e.g. as shown inFIG.1).

The assembly1650comprises an intermediate moveable element1656, which takes the form of a lever arm. The intermediate moveable element1656may be coupled to at least one SMA actuator wire1658to move the lever arm in a first direction. The intermediate moveable element1656moves about pivot1660. In embodiments, the lever arm1656may be coupled to another SMA actuator wire (not shown) to move the lever arm in a second direction. Alternatively, one of the actuator wires may be replaced by a return spring or similar resilient element. Further alternatively, the flexible portion of the housing1654may itself be stiff enough to provide a return force—in this case, a return spring or second SMA actuator wire may not be required. In some cases, the force of a user's finger may be sufficient to provide a return force, such that an SMA actuator wire or return spring is not required to return the button to an equilibrium position. Movement of the intermediate moveable element1656may cause the button portion1652of the housing1654to flex. Thus, the housing1654may be formed of a flexible material such that when the intermediate moveable element1656is actuated, the button portion1652flexes and provides a haptic sensation. Alternatively, the housing1654may be formed of a material which is not generally flexible unless it is provided as a thin layer. Thus, the button1652may be thinner than the rest of the housing1654such that the button portion is flexible. For example, at least the button1654may be formed from a locally-thinned section of the housing, e.g. a 30 μm thick layer of aluminium.

Thus, in embodiments, the intermediate moveable element may be a lever arm arranged to drive movement of the button along the first axis.

FIG.17shows a cross-sectional view of a fourteenth haptic button assembly1700. As mentioned above with respect toFIG.1, each haptic button assembly described here may comprise a sensor in the housing below the button and intermediate moveable element. The sensor may be a force sensor, for example. Generally speaking, the sensor may be any suitable sensor or mechanism for detecting depression of the button by a user (i.e. detecting that a user has pressed the button). The movement of the button into the cavity (as a result of the user pressing the button) causes a force to be exerted on the sensor. The sensor may be coupled to control circuitry, and the sensor may be configured to communicate with the control circuitry when the force on the sensor changes, or when the force on the sensor has been applied for a minimum duration. The detection by the sensor of a user pressing the button causes the haptic feedback to be generated and applied by haptic button assembly. The haptic button assembly1700shown inFIG.17comprises an alternative arrangement of the sensor, which may advantageously reduce the overall size/height of the assembly.

The haptic button assembly comprises a button1702and an intermediate moveable element1706, both provided in housing1704. The assembly comprises at least one SMA actuator wire1708, which is coupled at one end to the intermediate moveable element1706, and another end to the housing1704. A resilient biasing element1710may be coupled to the intermediate moveable element1706and the housing1704. The biasing element1710may be a weak spring, and may be weaker than a return spring because the force applied to the button by a user may be advantageously used to stretch out the SMA actuator wire1708. Thus, in embodiments, the force applied by a user can be utilised to provide the ‘return force’ against the SMA actuator wire, such that only a weak spring is required (or the spring may be removed completely). When a press of button1702is detected, the SMA actuator wire1708is driven, which causes the wire1708to contract. The contraction of the wire1708causes the intermediate moveable elements1706to move into the further cavity of the housing (as described with reference to e.g.FIG.1), which causes the button1702to move upwards (i.e. out of the cavity). The biasing element1710may enable the button1702to return to the equilibrium state as the SMA actuator wire1708cools.

The haptic button assembly1700may comprise an endstop1712in the cavity. The endstop1712may be formed as part of the housing1704or cavity, or may be a separate element that is provided in the cavity. The endstop1712may be provided at a location in the cavity to restrict movement of the intermediate moveable element1706. As explained above with reference toFIG.1, if SMA actuator wire is stretched too far (i.e. a certain tension is exceeded), the SMA actuator wire may weaken or become damaged, or even break. The force of the biasing element1710on the intermediate moveable element1706may cause the SMA actuator wire1708to become overstretched. Therefore, the endstop1712may restrict the movement of the intermediate moveable element1706so that the at least one SMA actuator wire1708does not overstretch. Similarly, a force applied to the button1702by a user's finger may cause the wire to overstretch if there is no endstop, because when the button is pushed downwards (i.e. into the cavity), the intermediate moveable element1706moves towards the left in the Figure, such that the SMA actuator wire1708is stretched.

The fact that the intermediate moveable element1706moves towards the endstop1712when the button is pressed1702is used to provide the alternative arrangement of the sensor. In assembly1700, a sensor1714is provided on the endstop1712. The sensor1712may be a contact sensor or a force sensor, and a conductive element1716may be provided on the intermediate moveable element1706. When the button1702is pressed, the downward force on the button causes the intermediate moveable element1706to move towards, and make contact with, the endstop1712. When the intermediate moveable element1706and endstop1712are in contact, the contact sensor1712and the conductive element1716make an electrical connection, which indicates that the button1702has been pressed and that haptic feedback should be delivered.

FIGS.18A and18Brespectively show cross-sectional views of a fifteenth haptic button assembly1800in an equilibrium state and in an activated state. The haptic button assembly1800comprises a button1802, a housing1804and an intermediate moveable element1806. The intermediate moveable element1806is a flat flexure, which is attached at one end1808to the housing1804. The other end1810of the flexure1806is not attached to the housing1804and is free to translate along the flexure's longitudinal direction. The button1802is coupled to (e.g. attached to) the flexure1806. The assembly1800comprises an SMA actuator wire1812which is coupled at one end to the free end1810of flexure1806and at another end to the housing1804. The SMA actuator wire1812may be arranged such that when the wire contracts (on heating), the wire forces an out-of-plane deflection of the flexure1806, which forces the button1802to move upwards, i.e. to move out of the cavity of the housing1804, as shown inFIG.18B. When the wire is cooled, the flexure1806returns to its equilibrium state (i.e. is substantially flat), which causes the button1802to move downwards within the cavity of the housing1804, as shown inFIG.18A. Advantageously, the flexure1806means that an additional bias spring is not required to oppose the effect of the SMA actuator wire1812. Thus, the assembly may be simpler and cheaper to manufacture and operate. Furthermore, compared to the embodiments which comprise a wedge-shaped button and/or intermediate moveable element (e.g.FIGS.1to3), the overall profile or size of the haptic button assembly1800may be reduced by using a flexure as the intermediate moveable element.

In embodiments, the assembly1800may be adapted to allow vertically ‘downward’ motion of the button1802, i.e. to allow the button1802to move into the cavity. (As mentioned earlier, haptic feedback may be provided by the button moving upwards into a user's finger, or by the button dropping away from the user's finger). In this case, the assembly1800may comprise a well or further cavity in the housing1804below the flexure1806. Thus, the flexure1806may be arranged to buckle or bend into the well/further cavity, and doing so causes the button1802to move further into the cavity.

FIG.19shows a plan view of a fifteenth haptic button assembly1900. (The button has been removed from the illustration for the sake of clarity). Here, intermediate moveable element1906is able to rotate within housing1904, rather than merely translate. As a result, the button (not shown) may also be able to rotate or tilt. This may be achieved by providing a series of ramps1908which are arranged such that the gradient of the ramps increases in the same direction along a helical (or substantially helical) path. In this example, the assembly1900comprises four ramps and ball bearings roll along the ramps in the same direction when the intermediate moveable element1906is actuated (by SMA actuator wires1902) such that the intermediate moveable element rotates. In some cases, a bearing layer may be provided between the button and the intermediate moveable element to prevent the button from rotating—the bearing layer may de-couple the button from the rotating intermediate moveable element. Suitable mechanisms may be used to keep the ball bearings in place, e.g. the bearings may be located in tracks or grooves to constrain their motion.

In embodiments, a single SMA actuator wire may be sufficient to drive motion of the intermediate moveable element1906. For example, as perFIG.17, the force of a user's finger may be sufficient to provide a return force, such that an SMA actuator wire is not required to return the button to an equilibrium position. Alternatively, to maximise the force used to move the button, multiple SMA actuator wires may be used (e.g. multiple wires arranged to be mechanically in parallel).

Turning toFIG.33Ashows a plan view of a button of a further haptic button assembly3300,FIG.33Bshows a plan view of the further haptic button assembly3300andFIG.33Cshows a cross-sectional view of the further haptic button assembly3300. The haptic button assembly3300comprises a button3302which is able to rotate within housing3304. The haptic button assembly3300comprises an intermediate moveable element3308and at least one SMA actuator wire to move the intermediate moveable element in one direction and a resilient element (e.g. a spring) to move the intermediate moveable element in the opposite direction. In the illustrated arrangement, the haptic button assembly3300comprises two SMA actuator wires3310a,3310bwhich may be arranged as opposing wires (i.e. one of the SMA actuator wires acts as the resilient element that provides the restoring force). In other words, SMA actuator wire3310amay move the intermediate moveable element3308in one direction, and SMA actuator wire3310bmay move the intermediate moveable element3308in an opposite direction. The haptic button assembly3300comprises a central shaft or bearing3306. The central bearing3306is coupled to the intermediate moveable element3308and to the button3302. Movement of the intermediate moveable element3308in one direction causes the central bearing3306to rotate in one direction, which thereby causes the button3302to rotate relative to the housing3304. Movement of the intermediate moveable element3308in the opposite direction causes the button3302to rotate in an opposite sense. The haptic button assembly3300may comprise a seal3312, such as a flexible sealing membrane, to prevent any fluid and/or dirt which enters the haptic assembly through the gap between the housing3304and the button3302from travelling any further into the haptic assembly, or into the device in which the haptic assembly is incorporated. The haptic button assembly3300may comprise one or more bearings (e.g. ball bearings)3314which are provided between the housing3304and the intermediate moveable component3308. The ball bearings3314may provide a low friction surface on which the intermediate moveable component3308is able to move.

Accordingly, the present techniques provide a haptic button assembly comprising: a housing comprising a cavity; a button provided within the cavity and moveable along a first axis within the cavity; at least one intermediate moveable element provided within the cavity in contact with the button and rotatable about a second axis that is parallel to the first axis, and arranged to drive movement of the button along the first axis; and at least one shape memory alloy (SMA) actuator wire coupled to the at least one intermediate moveable element and arranged to, on contraction, rotate the intermediate moveable element about the second axis.

FIG.20shows a cross-sectional view of a sixteenth haptic button assembly2000. In haptic button assembly2000, button2002is chevron-shaped, i.e. the button2002comprises two slopes which are inclined in opposite directions at equal angles. The assembly2000comprises two intermediate moveable elements2004and2006which are wedge-shaped. In this embodiment, the intermediate moveable element may be considered to be or comprise two ‘opposing wedges’, as the two elements are wedges having slopes inclined in opposite directions. The gradient of the wedge-shaped moveable element2004corresponds to one slope of the chevron-shaped button2002, and the gradient of the wedge-shaped moveable element2006corresponds to the other slope of the chevron-shaped button2002. In embodiments, the angles or gradients of the slopes of the two moveable elements2004,2006are the same, to prevent the button2002from tilting when the SMA actuator wire2008is driven. However, in some embodiments a tilt may be required and may be achieved by having differing slopes. It will be understood that the direction of the gradients or slopes of the two wedge-shaped moveable elements may be reversed without loss of functionality (though the slopes of the button2002will also need to be reversed). The two intermediate moveable elements2004,2006are coupled together via an SMA actuator wire2008.

A return spring2010is coupled to moveable element2004and the housing, and another return spring2012is coupled to moveable element2006and the housing. When a press of button2002is detected, the SMA actuator wire2008is driven, which causes the wire2008to contract. The contraction of the wire2008causes the intermediate moveable elements2004and2006to move towards each other, which causes the button2002to move upwards (i.e. out of the cavity). The return springs2010,2012may enable the button2002to return to the equilibrium state as the SMA actuator wire2008cools and a force is applied. In embodiments, the return springs may not be required as the force of the user's finger on the button2002may be sufficient to return the button to the equilibrium state after the haptic sensation has been provided. The assembly may comprise two endstops2010,2012to restrict the motion of the intermediate moveable elements2004,2006, respectively.

Thus, from the above-described embodiments and arrangements, it will be understood that the intermediate moveable element which causes the button to move ‘vertically’ may be a single wedge-shaped element (or element comprising localised wedges/ramps), may comprise two wedge-shaped elements (or elements comprising localised wedges/ramps), or may comprise opposing wedges. Alternatively, the intermediate moveable element may be a flexure (see e.g.FIG.18A), or a lever arm (see e.g.FIG.16). The intermediate moveable element be arranged to drive motion of the button (or button portion of the housing) into the housing or out of the housing (i.e. vertically ‘downwards’ or ‘upwards’).

Sealing Mechanisms

The haptic button assemblies may comprise a protective seal to prevent ingress of fluids and/or dirt/dust into the assembly. The haptic button assemblies described herein may be incorporated into a variety of different devices, including smartphones and wearables. Smartphone and wearable devices may be required to meet a particular waterproofing standard. For example, such devices may be required to meet the standard necessary for an Ingress Protection (IP) Rating of 67 or 68. An IP rating of 67 indicates the device has some sort of protection that results in the device being dust tight and being waterproof when the device is immersed in up to 1 m of water, while an IP rating of 68 indicates the device has some sort of protection that results in the device being dust tight and being waterproof when the device is continuously immersed in more than 1 m of water. Accordingly, if the haptic button assemblies are to be incorporated into a smartphone or wearable device with an IP rating of 67 or 68, the haptic button assembly also needs to be water and dust proof to the same standard.

As mentioned above, the haptic button assemblies described herein may be more readily, and more efficiently, sealed compared to haptic button assemblies in which the button moves laterally. There are a number of different possible sealing mechanisms, some of which are described with reference toFIGS.5,6,9A,11A-C,12A-C,13A-B, and14to16. Before these specific sealing mechanisms are described, some general concepts associated with the sealing mechanism are described.

Generally speaking, the sealing mechanism may be non-structural (i.e. it does not provide any intentional force on the button of the haptic button assembly), or may be structural (i.e. it provides some force on the haptic button assembly to, for example, guide the movement of the button).

In cases where the sealing mechanism is substantially non-structural, additional bearings may be required to constrain the lateral (sideways) motion of the button within the cavity. For example, a rolling bearing may be provided between the button and the cavity, on the same side of the button to which the SMA actuator wire is connected, such that when the SMA actuator wire contracts, the bearing prevents the button from moving sideways or from tilting within the cavity (i.e. constrains the motion of the button). Alternatively, when the sealing mechanism is non-structural, no rolling bearing may be provided between the button and the cavity—in this case, the direct contact of the button with the cavity is a high friction, low efficiency sliding contact which acts to constrain the motion of the button. In some embodiments, the sealing mechanism may be non-structural, and may be combined with a flexure to guide the motion of the button ‘vertically’ in the cavity. In this case, a rolling bearing between the cavity and button may not be required.

In cases where the sealing mechanism is structural, the sealing mechanism provides both a sealing function and a bearing function, i.e. the sealing mechanism is able to guide the motion of the button within the cavity. In this case, an additional bearing between the cavity and the button may not be required. Alternatively, the sealing mechanism may be provided by housing itself—the button may be an integral part of the housing such that no additional sealing mechanism is required. This may be achieved by making the button part of the housing thinner than the rest of the housing, such that it is flexible. However, in this case, a further button that a user may press/contact may be provided externally in order to protect the thin integrally-formed button of the housing.

Regardless of whether the sealing mechanism is structural or non-structural, the sealing mechanism may function at all times or may only function when the button of the haptic button assembly is not in motion.

Turning now toFIG.5, this shows a cross-sectional view of a fifth arrangement of a haptic button assembly500comprising a sealing mechanism which is structural and functions at all times (i.e. both when the button is in motion and is not in motion). The haptic button assembly500is similar to the arrangement shown inFIG.4and therefore, for the sake of conciseness, like features are not described. Compared to assembly400, haptic button assembly500comprises a protective seal542(also referred to as a protective membrane, film or cover). The protective seal542may be a waterproofing and/or dust proofing seal to prevent water and/or dust ingress into the cavity. Generally speaking, a small gap may be provided between the button and the cavity, to avoid contact between a surface of the button with a surface of the cavity, which may increase friction and affect the performance of the assembly. However, the gap may then enable liquid and/or dirt to enter the cavity of the assembly, where it could affect the performance of the assembly. For example, dirt could inhibit the movement of button, the bearings and/or the intermediate moveable element, while liquid could interfere with any electronic components/circuitry. Thus, the protective seal542may advantageously enable a waterproof/dustproof haptic button assembly to be provided.

The protective seal542may be provided across the entire area of the external surface of the housing (i.e. surface108inFIG.1) and the button (as shown inFIG.5), or may be provided across the button and at least part of the area of this external surface. In either case, the protective seal542may be formed of a flexible material, an elastic material, or a material which exhibits some flexibility/elasticity when it is provided as a thin layer, which enables the protective seal542to flex as the button moves. (If the protective seal542were not made of a flexible/elastic material, the protective seal may inhibit or limit the motion of the button, which may affect the haptic sensation delivered by the assembly). The protective seal542may be formed of an elastomer, hard plastic, a composite material, a thin metallic layer e.g. a thin aluminium or a thin stainless steel layer, for example. It will be understood that is a non-exhaustive, non-limiting example list of materials. The protective seal542may be attached to the housing504by any suitable technique, such as adhesive, welding, or otherwise.

Optionally, when a haptic button assembly comprises a protective seal, the housing of the assembly may be modified to accommodate the protective seal. As shown inFIG.5, the housing504comprises a cut-out or ledge544in the external surface of the housing, provided around the button. The cut-out or ledge544provides clearance or space between the button and the housing. The protective seal542may be able to bend/flex into the ledge544when the button moves in the cavity, such that a portion of the protective seal542which is able to move when the button moves is increased. This may advantageously reduce the extent to which the protective seal542resists the motion of the button.

It will be understood that the protective seal, and the optional cut-out, may be incorporated into any of the haptic button assemblies described herein.

FIG.6shows a cross-sectional view of a sixth arrangement of a haptic button assembly600comprising a sealing mechanism which is structural and functions at all times (i.e. both when the button is in motion and is not in motion). This may be considered to include a more extreme version of the cut-out shown inFIG.5. The haptic button assembly600is similar to the arrangements shown inFIGS.4and5and therefore, for the sake of conciseness, like features are not described. Compared to assembly500, haptic button assembly600comprises a reduced size (i.e. reduced height) button602. The button602comprises a protrusion646which forms the contact point or contact surface of button602. Thus, the area or size of the contact surface of button602is reduced relative toFIG.5. By reducing the height of the button602and providing the protrusion646as the contact surface, a large gap644is provided between the button602and protective seal642. Accordingly, the extent to which the protective seal642resists the motion of the button is further reduced. As explained above, the protective seal642may be formed of an elastomer, hard plastic, a composite material, a thin metallic layer e.g. a thin aluminium or a thin stainless steel layer, for example. It will be understood that is a non-exhaustive, non-limiting example list of materials.

Returning briefly toFIG.8, in this embodiment, the protective seal842acts as a flexure to guide the button to move in the first direction (vertically). Thus, the sealing mechanism is structural and functions at all times (i.e. both when the button is in motion and is not in motion).

FIGS.11A and11Brespectively show a plan view and a cross-sectional view of a mechanism1100for sealing a haptic button assembly, andFIG.110shows a cross-sectional view of a modified mechanism1100′. The sealing mechanism shown inFIGS.11A to11Cis structural and functions at all times (i.e. both when the button is in motion and is not in motion). The sealing mechanisms1100,1100′ may provide an efficient mechanism for water- and dust-proofing a haptic button assembly. The sealing mechanism1100comprises a flexible skin or membrane1102and an external button1104. The flexible skin1102may cover the cavity in the housing which houses the button1106, intermediate moveable element1108and at least one SMA actuator wire1110, as described earlier, such that the flexible skin1102effectively covers the cavity. The flexible skin1102may be considered an impermeable barrier between the external environment and the cavity of the housing of a haptic button assembly (i.e. the internal environment). Thus, the term ‘external button’ is used to mean that button1104is provided at least partly outside of the cavity, i.e. at least partly on the external side of the barrier formed by the flexible skin1102. The external button1104may cooperate with the (internal) button of the haptic button assemblies described earlier.

FIG.11Bshows an example internal button1106, which is provided on the internal side of the barrier formed by the flexible skin1102. The external button1104may comprise a stem1112that is arranged to cooperate with the internal button1106. In the mechanism1100shown inFIG.11B, the stem1112contacts the flexible skin1102. When the external button1104is pressed by a user, the stem1112exerts a force on the flexible skin1102, which causes the flexible skin1102to flex/bend. The force applied to the button1104is transferred via the stem1112to the internal button1106, and a press of the internal button1106is detected as described earlier (e.g. via a sensor located within the cavity).

FIG.11Cshows a sealing mechanism1100′ having a flexible skin1102′ which comprises a cut-out (not visible) to reduce the overall stiffness of the mechanism in the direction of motion. Thus, the stem1112of external button1104at least partly extends through the cut-out in the flexible skin1102′. Thus, the stem1112may be able to directly contact the internal button1106.

The flexible skin1102,1102′ may be made from any suitable material having an appropriate stiffness in the direction of motion. The flexible skin1102,1102′ is preferably an impermeable material, i.e. impermeable to liquids and dirt. The flexible skin1102,1102′ may be formed from a thin film polymer, for example. The flexible skin1102,1102′ may be formed of a material which is impermeable to liquid, such that the sealing mechanism protects the haptic button assembly against fluid ingress. The flexible skin may be, for example, a thin silicone film. The sealing mechanism1100,1100′ may comprise an adhesive or an adhesive element to fixedly attach the flexible skin1102,1102′ to the housing of the assembly. The flexible skin (also referred to as a thin membrane) may deflect sufficiently to enable the button1106to move within the haptic button assembly. The thin membrane1102,1102′ may provide a return force to return the button1106to its default, rest state when the intermediate moveable element1108is not being actuated to deliver a haptic sensation.

Advantageously, the sealing mechanisms1100,1100′ secure the haptic button assembly against ingress of liquid and/or dirt or dust. The flexible skin may enable a water and dust proof haptic button assembly to be provided along a curved edge of a device. The sealing mechanisms1100,1100′ decouple the sealing mechanism from the button/external button—this may be advantageous as the external button may then be customisable without affecting the sealing mechanism or mechanics of the assembly. For example, the design and texture of the external button may be selected/customised without impacting the sealing mechanism.

FIGS.12A to12Cshow cross-sectional views of three mechanisms for sealing a haptic button assembly.

FIG.12Ashows a portion of a haptic button assembly1200comprising a sealing mechanism which is non-structural and functions only when the button is not in use, because when the button moves upwards, the seal is broken. Here, button1202of the haptic button assembly performs two functions—it provides a contact surface which a user presses and it forms part of the sealing mechanism. The haptic button assembly1200comprises button1202, intermediate moveable element1206and one or more ball bearings1208, which are provided in a cavity of the housing1204of the assembly. The haptic button assembly shown here is similar to that shown inFIG.4and comprises localised ramps on both the button1202and the moveable element1206. At least one ball bearing1208is provided between pairs of localised ramps, as shown. The button1202comprises a lip1212that extends all the way around the button. The housing1204comprises a corresponding ledge or groove1210, and the lip1212of the button may engage with the ledge1210of the housing1204. The ledge1210may, for example, restrict the movement of the button1202into the cavity of the housing1204, and thereby providing a sealing effect. The button1202may be formed of a thick flexible material, such that the button1202flexes when the button is pressed and when the intermediate moveable element1206is actuated. The button1202may be moulded from a flexible material. The button1202may be formed of a material which is impermeable to liquid, such that the sealing mechanism protects the haptic button assembly against fluid ingress. The button1202may be bonded to the housing1204—the lip1212may be fixedly attached to the ledge1210of the housing1204, thereby providing a seal. The sealing mechanism may comprise an adhesive or an adhesive element to fixedly attach the button1202to the housing1204. The button1202may deflect sufficiently to enable the button to move within the haptic button assembly. The button1202may provide a return force to return the button to its default, rest state when the intermediate moveable element1206is not being actuated to deliver a haptic sensation.

FIG.12Bshows a portion of a haptic button assembly1220comprising a sealing mechanism which is non-structural and functions only when the button is not in use, because when the button moves upwards, the seal is broken. Here, button1222of the haptic button assembly performs two functions—it provides a contact surface which a user presses, and it forms part of the sealing mechanism. The haptic button assembly1220comprises button1222, intermediate moveable element1226and one or more ball bearings1228, which are provided in a cavity of the housing1224of the assembly. Compared toFIG.12A, the embodiment shown inFIG.12Bcomprises one or more localised ramps on one surface only, i.e. on the button1222or the intermediate moveable element1226. In the arrangement shown inFIG.12B, the intermediate moveable element1226comprises at least one localised ramp. At least one ball bearing1228is provided between the ramp of the intermediate moveable element1226and the button1222. The intermediate moveable element1226may comprise one or more supports1234which extend towards and support the button1222.

The button1222comprises a lip1232that extends all the way around the button. The housing1224comprises a corresponding ledge or groove1230, and the lip1232of the button may engage with the ledge1230of the housing1224. The ledge1230may, for example, restrict the movement of the button1222into the cavity of the housing1224, and thereby providing a sealing effect. The button1222may be formed of a thin layer of material, such that the button1222flexes when the button is pressed and when the intermediate moveable element1226is actuated. The button1222may be moulded from a flexible material, or may be formed from a thin metallic film or layer. The button1222may be formed of a material which is impermeable to liquid, such that the sealing mechanism protects the haptic button assembly against fluid ingress. The button1222may be bonded to the housing1224—the lip1232may be fixedly attached to the ledge1230of the housing1224, thereby providing a seal. The sealing mechanism may comprise an adhesive or an adhesive element to fixedly attach the button1222to the housing1224. The button1222may deflect sufficiently to enable the button to move within the haptic button assembly. The button1222may provide a return force to return the button to its default, rest state when the intermediate moveable element1226is not being actuated to deliver a haptic sensation.

FIG.12Cshows a portion of a haptic button assembly1240comprising a sealing mechanism which is structural and functions at all times (i.e. both when the button is in motion and is not in motion). Here, button1242of the haptic button assembly performs two functions—it provides a contact surface which a user presses and it forms part of the sealing mechanism. The haptic button assembly1240comprises button1242, intermediate moveable element1246and one or more ball bearings1248, which are provided in a cavity of the housing1244of the assembly. Compared toFIG.12B, the embodiment shown inFIG.12Ccomprises one or more localised ramps on one surface only, i.e. on the button1242or the intermediate moveable element1246. In the arrangement shown inFIG.12C, the intermediate moveable element1246comprises at least one localised ramp. At least one ball bearing1248is provided between the ramp of the intermediate moveable element1246and the button1242. The button1242comprises a lip1252that extends all the way around the button. The housing1244comprises a corresponding ledge or groove1250, and the lip1252of the button may engage with the ledge1250of the housing1244, optionally via an O-ring1258. The O-ring1248is provided on ledge1250of the housing and between the ledge and the lip1252of the button. In embodiments, the O-ring1258may be replaced by any suitable internal seal, that is able to prevent ingress of dirt and liquid into the housing of the button assembly. For example, internal seal1258could be a flexible Y-shaped seal, flexible C-shaped seal, flexible hollow O-ring, etc. The ledge1250may, for example, restrict the movement of the button1242into the cavity of the housing1244, and thereby providing a sealing effect. The button1242(or at least the contactable/pressable portion of the button) may be formed of a thin layer of material, such that the button1242flexes when the button is pressed and when the intermediate moveable element1246is actuated. The button1242may be moulded from a flexible material, or may be formed from a thin metallic film or layer. The button1242may be formed of a material which is impermeable to liquid, such that the sealing mechanism protects the haptic button assembly against fluid ingress. The internal seal1258provides an additional barrier against dirt or fluid ingress.

The button assembly1240may comprise a flexure1252or similar flexible element provided below the button1242. The flexure1252extends across the cavity of the button assembly below the button1242, and is attached along its edge(s) to an internal surface of the housing1244. Thus, flexure1252may function as a further barrier against dirt or fluid ingress. The flexure1252is flexible and is therefore able to flex when the button1242moves in and out of the cavity of the housing1244. A gap1260between the flexure1252and the housing1244may be provided to provide a space into which the flexure1252can flex/bend into when the button1242moves upwards. Accordingly, when a flexure1252is provided, ball bearing1248is provided between the ramp of the intermediate moveable element1246and the flexure1252below the button1242. The button1242may be bonded to the housing1244—the lip1252may be fixedly attached to the ledge1250of the housing1244, thereby providing a seal. The sealing mechanism may comprise an adhesive or an adhesive element to fixedly attach the button1242to the housing1244. The button1242may deflect sufficiently to enable the button to move within the haptic button assembly. The button1242may provide a return force to return the button to its default, rest state when the intermediate moveable element1246is not being actuated to deliver a haptic sensation.

FIGS.13A and13Bshow cross-sectional views of two mechanisms for sealing a haptic button assembly.

FIG.13Ashows a portion of a haptic button assembly1300comprising a sealing mechanism which is non-structural and functions at all times (i.e. both when the button is in motion and is not in motion). The sealing mechanism comprises an O-ring type of seal1310. The O-ring1310is provided between button1302and housing1304of the haptic button assembly1300. The cavity comprises button1302, intermediate moveable element1306and one or more ball bearings1308. The haptic button assembly shown here is similar to that shown inFIG.4and comprises localised ramps on both the button1302and the moveable element1306. It will be understood however, that the localised ramp(s) could be more generally provided on one or both of the button1302and the moveable element1306(see e.g.FIG.12C). At least one ball bearing1308is provided between pairs of localised ramps, as shown. The O-ring1310constrains the edges of button1302within the housing1304of the button assembly. The1310may permit some movement or flexing of the button1302in and out of the housing1304, but prevents or minimises lateral (sideways) movement of the button1302in the housing. The O-ring1310forms a tight seal between the button1302and the housing1304and thereby protects the haptic button assembly against fluid and dirt ingress.

FIG.13Bshows a portion of a haptic button assembly1350comprising a sealing mechanism which is structural and functions at all times (i.e. both when the button is in motion and is not in motion). The sealing mechanism comprises an internal seal1360. The internal seal1360is provided between button1352and housing1354of the haptic button assembly1350. The cavity comprises button1352, intermediate moveable element1356and one or more ball bearings1358. The haptic button assembly shown here is similar to that shown inFIG.4and comprises localised ramps on both the button1352and the moveable element1356. It will be understood however, that the localised ramp(s) could be more generally provided on one or both of the button1352and the moveable element1356(see e.g.FIG.12C). At least one ball bearing1358is provided between pairs of localised ramps, as shown. The internal seal1360is provided across a portion of both the button1352and the cavity of the housing1354. Specifically, the internal seal1360is provided where edges of the button1352and cavity meet. The internal seal1360is provided below the button1352and within the cavity such that it cannot be seen from the outside of the button assembly1350. The internal seal1360may be ring shaped, for example. The internal seal1360may be attached to both the cavity and the button1352such that when button1352moves within the cavity, the seal1360prevents or minimises ingress of dirt and fluid into the cavity. The internal seal1360may be formed of a flexible material to enable the button1352to move within the cavity to deliver a haptic sensation.

FIG.14shows a cross-sectional view of a portion of an eleventh haptic button assembly1400comprising a sealing mechanism which is structural and functions at all times (i.e. both when the button is in motion and is not in motion). The arrangement is similar to that shown inFIG.12C. Here, the O-ring type internal seal1310shown inFIG.12Cmay be replaced with a Y-shaped flexible internal seal, C-shaped seal or hollow O-ring1410. The haptic button assembly1400comprises button1402, intermediate moveable element1406and one or more ball bearings1408, which are provided in a cavity of the housing1404of the assembly. The haptic button assembly shown here comprises localised ramps on both the button1402and the moveable element1406. It will be understood however, that the localised ramp(s) could be more generally provided on one or both of the button1402and the moveable element1406(see e.g.FIG.12B). At least one ball bearing1408is provided between pairs of localised ramps, as shown.

The button1402comprises a notch1414along one or more surfaces of the button which are within the cavity of the housing1404. The notch1414may, for example, be a circumferential notch provided around a surface of the button1402. The housing1404comprises a groove or notch1412in one or more surfaces of the cavity of the housing. The groove1412may be, for example, a circumferential groove provided around a surface of the cavity. The Y-shaped flexible internal seal1410comprises a portion which extends into the notch1414of the button1402, and a portion which extends into the groove1412of the cavity wall. In the arrangement depicted inFIG.14, the stem portion of the Y-shaped seal is provided in the notch1414and the fork or V portion of the Y-shaped seal is provided in the groove1412. (It will be understood that, alternatively, the step portion may be provided in groove1412and the fork portion in the notch1414). The stem portion of the Y-shaped seal1410may be fixedly attached in notch1414, and each end of the fork portion may be fixedly attached in groove1412. The Y-shaped seal1410is formed of a flexible material such that when the button1402moves up and down in the cavity, the seal stretches and continues to prevent ingress of fluid and dirt into the cavity. The Y-shaped seal1410may also function as a spring or resilient element because when one of the prongs of the fork portion is compressed, the other prong is stretched and provides a return force.

FIG.15shows a cross-sectional view of a portion of a twelfth haptic button assembly1500comprising a sealing mechanism which is structural and functions at all times (i.e. both when the button is in motion and is not in motion). The haptic button assembly1500comprises a button1502and a housing1504. In this case, the button1502is part of the housing1504. The housing1504may comprise at least a portion which is flexible and pressable and therefore provides the button1502of the assembly1500. The assembly comprises an intermediate moveable element1506and one or more ball bearings1508. The haptic button assembly comprises localised ramps on both the button1502(i.e. the button portion of the housing1504) and the moveable element1506. At least one ball bearing1508is provided between pairs of localised ramps, as shown. Advantageously, by forming the button1502as part of the housing1504, there is no gap between the button and the housing and therefore, a sealing mechanism is not required. This may also provide a cheaper and simpler assembly to manufacture. The housing1504may be formed of a flexible material such that when the intermediate moveable element1506is actuated, the button portion1502flexes and provides a haptic sensation. Alternatively, the housing1504may be formed of a material which is not generally flexible unless it is provided as a thin layer. Thus, the button1502may be thinner than the rest of the housing1504such that the button portion is flexible. For example, at least the button1504may be formed from a thin layer of metal, e.g. a 50 μm thick layer of aluminium, or of stainless steel or of flexible/deformable glass.

Similarly, returning briefly toFIG.16, the assembly1600comprises a sealing mechanism (i.e. the housing1604) which is structural and functions at all times (i.e. both when the button is in motion and is not in motion).

It will be understood that any of the sealing mechanisms described herein may be used with any of the haptic button assemblies described herein. Many of the sealing mechanisms described above are independent of the curvature of surface/edge of the device into which the haptic button assembly is incorporated.

SMA Actuator Wire Arrangements

As mentioned earlier, the haptic button assemblies described with reference toFIGS.1to8may comprise an SMA actuator wire and a return spring coupled to the same edge of the intermediate moveable element, but this is a non-limiting arrangement and other arrangements are possible. For example, the haptic button assemblies may comprise two or more SMA actuator wires. The SMA actuator wires may all be parallel to each other. The SMA actuator wires may all act in the same direction (i.e. they may, on contraction, cause the intermediate moveable element to move in the same direction), which may advantageously increase the force applied to the intermediate moveable element. Each wire of the two or more SMA actuator wires may be driven in unison or may be separately driveable. If each wire is separately driveable, the force applied to the intermediate moveable element may be variable and thus, the haptic sensation delivered to a user may be varied (e.g. may be made softer or stronger). Alternatively, one or more of the SMA actuator wires may act in the opposite direction to one or more of the remaining SMA actuator wires. In this case, as mentioned earlier, SMA actuator wires may be used to provide a reversed or return force, and may thereby replace the return spring. The SMA actuator wire or wires may, in embodiments, run alongside the intermediate moveable element. That is, the SMA actuator wire(s) may be coupled to and extend across a side of the intermediate moveable element, instead of being coupled to an edge and extending into the further cavity. Advantageously, such an arrangement of SMA actuator wires may reduce the width or length of the haptic button assembly, as the further cavity is no longer required.

Example arrangements of SMA actuator wires are described below with reference toFIGS.9B to9D.FIGS.9B,9C and9Dshow various arrangements of SMA actuator wire in a haptic button assembly900′. Generally speaking, the force available to move the intermediate moveable element may be proportional to the number of SMA actuator wires provided in a mechanically parallel arrangement in the assembly. Furthermore, the overall stroke of the actuation mechanism in the assembly may depend on the length of the SMA actuator wire(s)—longer SMA actuator wires generally provide increased stroke. Generally, the wire arrangements may comprise parallel wires that are mechanically in parallel but electrically in series (e.g. wire loops), parallel wires that are both mechanically and electrically in series/parallel, parallel wires that are mechanically in series but electrically in parallel, or independently driven opposing wires.

The haptic button assembly900′ is similar to the arrangement shown inFIG.1and therefore, for the sake of conciseness, like features are not described. In the haptic button assembly900′, at least one SMA actuator wire908runs along at least one side of intermediate moveable element906, instead of being coupled to an edge and extending into the further cavity (seeFIG.9A, for example). Thus, compared to e.g.FIG.9A, the stroke of the actuation mechanism ofFIGS.9B-Dis greater because the SMA actuator wire is longer. InFIG.9B, the haptic button assembly900′ comprises at least one SMA actuator wire908, where the or each wire is coupled at one end to the intermediate moveable element906via a connector or crimp910b, and at another end to the housing904via a connector or crimp910a. Thus, a large portion of the at least one SMA actuator wire908is parallel to a side of the intermediate moveable element906. A return spring912may be coupled between the intermediate moveable element906and the housing904. One or more ball bearings918may be provided between button902and the intermediate moveable element906, and between the intermediate moveable element906and the housing904, as described above with reference to any ofFIGS.1to8. This arrangement of SMA actuator wire(s)908may provide a more compact haptic button assembly.

FIG.9Cshows a plan view of a haptic assembly comprising two parallel SMA actuator wires. As mentioned above, the haptic button assembly900′ may comprise at least one SMA actuator wire908. InFIG.9C, the haptic button assembly is shown to comprise two parallel SMA actuator wires908a,908bwhich are coupled to (and extend across) opposite sides of the intermediate moveable element906. The two SMA actuator wires908a,908bmay act in the same direction (i.e. may apply a force to the intermediate moveable element in the same direction), or may act in opposite directions. In the former case, the two SMA actuator wires advantageously provide twice the force of a single wire, while in the latter case, the wires may remove the need for return spring912. A first SMA actuator wire908ais coupled at one end to the intermediate moveable element906via a connector or crimp910b, and at another end to the housing904via a connector or crimp910a. A second SMA actuator wire908bis coupled at one end to the intermediate moveable element906via a connector or crimp910d, and at another end to the housing904via a connector or crimp910c.

FIG.9Dshows a variation of the assembly900depicted inFIG.9B. Here, a single SMA actuator wire908′ is hooked at its midpoint over a hook920provided on a side of the intermediate moveable element906. The two halves of the SMA actuator wire908′ mechanically act in parallel and therefore, the SMA actuator wire908′ may provide twice the force of a single wire. This may be advantageous relative toFIG.9Cbecause only one set of connectors/crimps are required to couple the SMA actuator wire908′ to the intermediate moveable element906and housing904. Further advantageously, both of the connectors910a,910bare provided on the housing904. As the SMA actuator wire908′ needs to be powered, the connectors910a,910bare electrical connectors (to connect the SMA actuator wire to a power supply), and therefore, the arrangement ofFIG.9Dsimplifies the connections and circuitry to power the wire908′.

It will be understood that any of the haptic assemblies described herein may comprise SMA actuator wire(s) which is either under tension or which is slack. In some cases, when a user presses the button, the force exerted by the user on the button may cause the SMA actuator wire(s) to be stretched. This may mean a required pre-load is applied to the SMA actuator wire(s) to achieve an optimal phase transformation when the SMA actuator wire(s) is powered. The force applied by the user may cause the SMA actuator wire to be stretched to its original length. When the user applies a force to the button, the intermediate moveable element may be forced to move laterally/horizontally such that the SMA actuator wire stretches. In some cases, the SMA actuator wire may be considered to be slack when the length of the SMA actuator wire between two coupling elements (e.g. crimp connector or welded component) is longer than the distance between the two coupling elements when no external load is applied to the button/intermediate moveable element by a user (e.g. the system is in equilibrium) at ambient temperature (which may, in some cases be, 25° C.). More particularly, the SMA actuator wire may be considered to be slack when the length of the SMA actuator wire between two coupling elements is longer than the distance between the two coupling elements when the intermediate moveable element abuts against an endstop within the cavity.

In some cases, the SMA actuator wire(s) may be much longer than the distance between the two coupling elements when no external load is applied/the system is in equilibrium, at ambient temperature (which may, in some cases be, 25° C.). In other words, the SMA actuator wire may not always be in tension.

In some cases, the SMA actuator wire(s) may be much shorter than the distance between the two coupling elements when no external load is applied/the system is in equilibrium, at ambient temperature (which may, in some cases be, 25° C.). In other words, the SMA actuator wire may always be in tension.

In some cases, the SMA actuator wire(s) may have a precise amount of slack, at ambient temperature (which may, in some cases be, 25° C.). For example, the distance between the two coupling elements when no external load is applied/the system is in equilibrium may be 7.5 mm, and the length of SMA actuator wire may be 7.5 mm plus a precise amount of slack. The amount of slack may be between a few microns and no more than a few tens of microns.

Thus, in embodiments, the at least on SMA actuator wire may be slack.

The SMA actuator wire(s) used in any of the haptic assemblies described herein may be uncoated, or may be coated with an electrically insulating layer/coating. In some cases, the SMA actuator wire may be coated with an electrically insulating layer of thickness in the range from 0.3 μm to 10 μm. The electrically insulating layer may coat the entire length of each SMA actuator wire or a part of the length of each SMA actuator wire. Techniques for providing the coated SMA actuator wire are described in WO2015/036761. Although WO2015/036761 describes the use of coated wire or partly-coated wire in miniature cameras, it will be understood that the techniques described therein may be utilised in other applications, such as haptics.

Gapless Designs

Various techniques for sealing a haptic assembly have been described above. Alternatively, haptic assemblies which are gapless (or partly gapless, or gapless when not in use), are now described. The truly gapless haptic assemblies may not require any additional sealing mechanisms. The haptic assemblies which are partly gapless or gapless when not in use may require additional sealing mechanisms, such as those described above, in order to provide sealing.

The term “gapless” is used herein to generally mean any haptic assembly in which there is no gap between the button/moveable component and the housing. The term “gapless” is used interchangeably herein with the term “truly gapless”.

The term “partly gapless” is used herein to mean a haptic assembly in which there is no visible gap or which appears to be gapless, but in which there is actually a gap between the button/moveable component and the housing. In some cases, the gap may only become visible when the button/moveable component is being actuated to deliver a haptic sensation. The term “partly gapless” is used interchangeably herein with the terms “gapless when not in use”, “near gapless”, “unibody”, “apparently gapless”, and “no visible gap”. In some cases, a device such as a smartphone may be formed from two or more pieces/components to provide an apparently unibody or gapless device. As described below, a haptic assembly may be provided within a device such as the gap or join line between the pieces/components of the device are used to provide a gap between the button/moveable component and the housing of the haptic assembly.

FIGS.21A and21Brespectively show cross-sectional views of a gapless haptic assembly2100in an equilibrium state and in an activated state. The haptic assembly2100may be coupled to a flexible piece of material2106. The flexible piece of material2106may be, for example, a flexible portion of a casing of a smartphone or of a housing of a consumer electronics device, or may be a flexible display screen or flexible surface. It will be understood that these are merely exemplary. Alternatively, the flexible piece of material2106may be part of the haptic assembly2100itself. It will also be understood that the flexible piece of material may be replaced by a button of the type shown inFIG.1, for example, such that the haptic assembly is used to move the button. Thus, the haptic assembly2100may be gapless, apparently gapless or to have a visible gap, depending on other design criteria.

The haptic assembly2100comprises a first moveable arm2102awhich is fixedly connected at a first end2112to the flexible piece of material2106, and rotatably/moveably connected at a second end via a hinge2110(or similar) to a first end of a second moveable arm2102b. The second moveable arm2102bis fixedly connected at a second end to a static component2104. The haptic assembly2100comprises a third moveable arm2102cwhich is fixedly connected at a first end2112to the flexible piece of material2106, and rotatably connected at a second end via a hinge2110(or similar) to a first end of a fourth moveable arm2102d. The fourth moveable arm2102dis fixedly connected at a second end to the static component2104. At least one SMA actuator wire2108is connected to the pins2110. The at least one SMA actuator wire2108is arranged such that when the wire(s) contract(s) (on heating), the angle between the first moveable arm2102aand the second moveable arm2102bincreases, and the angle between the third moveable arm2102cand the second moveable arm2102dincreases. In other words, the ends of the first and second moveable arms which are connected to the moveable component2106and static component2104move further apart, and the ends of the third and fourth moveable arms which are connected to the moveable component2106and static component2104move further apart. As a result, the first moveable arm2102aand third moveable arm2102cpushes upwards against the flexible piece of material2106, causing the flexible piece of material2106to bend/deflect in the direction of arrow A, as shown inFIG.21B. When the at least one SMA actuator wire2108is cooled, the moveable arms2102a-dreturn to their equilibrium state, which causes the flexible piece of material to move downwards and return to being substantially flat, as shown inFIG.21A. In some cases, the haptic assembly2100may comprise an additional resilient element (e.g. a return spring or an opposing SMA actuator wire) to provide a return force. In some cases, the force of a user's finger may be sufficient to provide a return force, such that an SMA actuator wire or return spring is not required to return the moveable component2106to an equilibrium position.

It will be understood that at least one of the two pivot points (hinges2110) must be able to move in a direction parallel to the length of the SMA actuator wire2108. If only one side is free to translate, the button will ‘tilt’. Otherwise, it will move upwards symmetrically about the line of symmetry of the mechanism.

It will be understood that the first and second moveable arms may be a flexure, and the third and fourth moveable arms be another flexure.

If the flexible piece of material2106is a part of the casing of a smartphone, for example, the haptic assembly2100may be advantageous because the design may be configured to be gapless when compared to, for example, the embodiments which comprise a wedge-shaped button and/or intermediate moveable element (e.g.FIGS.1to3). This means that the device containing the haptic assembly2100may be substantially dust-proof and/or water-proof.

FIG.23Ashows a cross-sectional view of a gapless haptic assembly2300, andFIGS.23Bto E show cross-sectional views of a flexible portion of the gapless haptic assembly2300ofFIG.23A. The haptic assembly2300may be incorporated into or otherwise provided along an edge of an electronic device or on a surface of an electronic device. The haptic assembly2300may be arranged to move a flexible portion of a casing of a smartphone or of a housing of a consumer electronics device, for example. The haptic assembly2300may be provided as a standalone module that may be incorporated into an electronic device during manufacturer. Alternatively, some or all of the components of the haptic assembly2300may be integrally formed in an electronic device.

The haptic assembly2300comprises a housing2304. The housing2304is shaped (e.g. by forming, etching, or otherwise), to comprise a button portion2302and a flexible portion2312. The flexible portion2312is connected to the button portion2302such that it surrounds the button portion2302. The flexible portion may be formed of thinner material than the button portion2302to provide the flexibility. The button portion2302comprises a contact surface2306. In embodiments, the contact surface2306may be substantially level with/flush with an external surface2308of the housing2304when the haptic assembly is in an equilibrium state.

The haptic assembly2300comprises an intermediate moveable element2310similar to that shown inFIG.22, and for the sake of simplicity, the features and operation of the intermediate moveable element will not be described again. When the intermediate moveable element2310moves, the button portion2302of the housing is caused to move within/relative to the housing2304. The button portion2302is able to move because the flexible portion2312is flexible. The haptic assembly2300is advantageous because the button portion2302is part of the housing2304such that there is no external gap between the button portion and the housing2304when the haptic assembly2300is intergrated into devices such as a smartphone. Thus, the haptic assembly2300is substantially water-proof and/or dust-proof.

As shown inFIGS.23B to23Dthe flexible portion2312may take on various forms. InFIG.23B, the flexible portion2312is simply thinner than the button portion2302. This may be useful as it may enable a smooth edge or surface to be provided when the haptic assembly2300is integrated into a device such as a smartphone. In other words, this form of the flexible portion2312may be the most aesthetically-pleasing to a user. However, as the flexible portion2312needs to flex to enable the button portion2302to move, it may be useful for the flexible portion2312to have a non-linear profile. In other words, it may be useful for the flexible portion2312to be shaped in some way or to comprise one or more bends/curves, which provide the flexible portion2312with the structure to enable it to flex easily. Thus, inFIG.23C, the flexible portion2312is dome-shaped, while inFIG.23D, the flexible portion is dimple- or well-shaped. InFIG.23E, the flexible portion2312has a wavy or undulating form. InFIG.23F, the flexible portion2312may comprise a point about which the flexible portion may bend/flex. It may be advantageous to provide more than one flexible portion2312on either side of the button2302, to further reduce stiffness/increase the flexibility of the flexible portion. For example, it may be useful to combine any of the flexible portions2312shown inFIGS.23B to23Fin a series combination on either side of the button2302. An example of this is shown inFIG.23G—here, two of the flexible portions2312shown inFIG.23Fare combined to form a larger combined flexible portion2312′. This larger combined flexible portion2312′ may be provided on either side of the button2302. It will be understood that different shaped flexible portions2312may be combined in series to form the combined flexible portion2312′.

FIG.24shows a cross-sectional view of a partly gapless haptic assembly2400. The haptic assembly2400may be incorporated into or otherwise provided along an edge of an electronic device or on a surface of an electronic device. The haptic assembly2400may be arranged to move a flexible portion of a casing of a smartphone or of a housing of a consumer electronics device, for example. The haptic assembly2400may be provided as a standalone module that may be incorporated into an electronic device during manufacturer. Alternatively, some or all of the components of haptic assembly2400may be integrally formed in an electronic device.

The haptic assembly2400may comprise a housing2404. In this case, the haptic assembly2400may be a module which is incorporated into an electronic device. Alternatively, the housing2404may be part of an electronic device (and not part of the haptic assembly) into which the components of the haptic assembly2400are incorporated. In this case, the electronic device may be more aesthetically pleasing to a user because the edge or surface of the electronic device where the haptic assembly2400is located may be substantially smooth and nearly gapless/apparently gapless. This may allow an electronic device to be produced which has smooth edges/surfaces that do not have protruding buttons. Instead of having a visible, protruding button, the haptic assembly2400may provide haptic feedback when a user contacts (or is in the vicinity of) a ‘non-protruding button’ of the haptic assembly.

The housing2404(whether it is part of the haptic assembly2400or otherwise) comprises a (non-protruding) button portion2402. One or more edges of the button portion2402may be connected to the housing2404. In the embodiment shown inFIG.24, at least one edge of the button portion2402is not connected to the housing2404. This allows the button portion2402to move relative to the housing2404(as indicated by the arrow) when the haptic assembly2400is activated. The button portion2402may comprise a thinner hinge portion2410. The hinge portion2410of the button portion2402may be thinner than the rest of the button portion, such that the button portion2402is able to move/flex about the hinge portion2410. In other words, the thinner hinge portion2410may provide the button portion2402with the flexibility to move relative to the housing2402. The hinge portion2410may be provided by machining, forming, etching or half-etching the button portion2402to remove material. The button portion2402comprises a contact surface. The contact surface may be substantially level with/flush with an external surface of the housing2402when the haptic assembly is in an equilibrium state.

The haptic assembly2400comprises an intermediate moveable element2406similar to that shown inFIG.22, and for the sake of simplicity, the features and operation of the intermediate moveable element will not be described again. When the intermediate moveable element2406moves, the button portion2402of the housing is caused to move within/relative to the housing2404. The button portion2402is able to move because the hinge portion2410provides some flexibility to the button portion. At least one bearing2408(e.g. a ball bearing—see also the definition above of the term ‘bearing’) is disposed between the button portion2402and the intermediate moveable element2406. The at least one bearing2408may facilitate the lateral movement of the button portion2402when the intermediate moveable element2406moves. The haptic assembly2400may be advantageous because the button portion2402is part of, and connected to the housing2404such that there is a reduced external gap between the button portion and the housing2404when the haptic assembly2400is integrated into a device such as a smartphone. For example, if the button portion2402is connected to the housing2404by three of its four edges (such that only one edge of the button portion2402is free and unconnected to the housing), the gap is much reduced compared to, for example, the embodiment ofFIG.1. Furthermore, the gap may be minimal (and potentially even difficult to see/not easily visible) when the haptic assembly2400is in an equilibrium state. When the haptic assembly2400is in an active state and the button portion2402is moving relative to the housing2404, the gap may be larger and more visible. Thus, the haptic assembly2400may reduce the possibility of dust and/or water ingress into the device at least when then haptic assembly is in the equilibrium state.

FIG.25shows a cross-sectional view of a gapless haptic assembly2500. The haptic assembly2500may be incorporated into or otherwise provided along an edge of a smartphone or on a surface of a smartphone. The haptic assembly2500may be a provided as a standalone module that may be incorporated into an electronic device during manufacture. Alternatively, some or all of the components of haptic assembly2500may be integrally formed in an electronic device.

The haptic assembly2500may comprise a housing2504. In this case, the haptic assembly2500may be a module which is incorporated into an electronic device. Alternatively, the housing2504may be part of an electronic device (and not part of the haptic assembly) into which the components of the haptic assembly2500are incorporated. In this case, the electronic device may be more aesthetically pleasing to a user because the edge or surface of the electronic device where the haptic assembly2500is located may be substantially smooth and gap-free. This may allow an electronic device to be produced which has smooth edges/surfaces that do not have protruding buttons. Instead of having a visible, protruding button, the haptic assembly2500may provide haptic feedback when a user contacts (or is in the vicinity of) a ‘non-protruding button’ of the haptic assembly.

The housing2504(whether it is part of the haptic assembly2500or otherwise) comprises a (non-protruding) button portion2502. All of the edges of the button portion2502may be connected to the housing2504. However, the button portion2502is thinner than the rest of the housing2504—this allows the button portion2502to move relative to the housing2504(as indicated by the arrow) when the haptic assembly2500is activated. In other words, the thickness of the button portion2502may provide the button portion2502with the flexibility to move relative to the housing2502. The button portion2502may be provided by machining, stamping, etching or half-etching the housing2502to remove material. The button portion2502comprises a contact surface. The contact surface may be substantially level with/flush with an external surface of the housing2502when the haptic assembly is in an equilibrium state.

The haptic assembly2500comprises an intermediate moveable element2506similar to that shown inFIG.22, and for the sake of simplicity, the features and operation of the intermediate moveable element will not be described again. When the intermediate moveable element2506moves, the button portion2502of the housing is caused to move within/relative to the housing2504. At least one bearing2508(e.g. a ball bearing or plain bearing) may be disposed between the button portion2502and the intermediate moveable element2506. The at least one bearing2508may facilitate the lateral movement of the button portion2502when the intermediate moveable element2506moves. Alternatively, the bearing2508may be replaced by some support mechanism to support the button portion on the actuator, as the button portion2502may be formed of a thin piece of material (i.e. may be formed by locally-thinning the housing2504) and may be easily damaged or punctured if it is not supported. The haptic assembly2500may be advantageous because the button portion2502is part of the housing2504such that there is no gap between the button portion and the housing2504when the haptic assembly2500is integrated into a device such as a smartphone. Thus, the haptic assembly2500is substantially water-proof and/or dust-proof.

As mentioned above with reference toFIGS.24and25, the button or moveable element of the haptic assemblies may be part of the housing itself. InFIG.24, the button portion is connected along at least one edge to the housing, while inFIG.25, the button portion is completely connected to the housing. Turning toFIG.26, this shows schematic diagrams of gapless and partly gapless haptic assemblies. Specifically,FIG.26shows schematic plan views of the moveable element (or button or button portion) of five haptic assemblies2600-2614. In haptic assembly2600, short edges2604of moveable element2602are mechanically connected to the housing (not shown) of the haptic assembly (i.e. are mechanically constrained), while long edges2606are mechanically constrained to be ‘free’. When the haptic assembly2600is in the equilibrium state, the haptic assembly2600may appear ‘gapless’ and may be substantially water-proof and/or dust-proof. However, when the haptic assembly2600is activated and the moveable element2602moves, gaps between the moveable element2602and the housing may appear and therefore, the assembly may not be water- and/or dust-proof while the haptic assembly2600is delivering haptic feedback.

In haptic assembly2608, the moveable element2602comprises only one ‘free’ long edge2606. In haptic assembly2610, the moveable element2602comprises no free edges, i.e. both the long edges and short edges are fixed. In haptic assembly2612, the short edges2604of the moveable element2602are free while the long edges are fixed. In haptic assembly2614, the moveable element2602comprises only one free short edge. Haptic assembly2610, which has four fixed edges, is the stiffest and provides the most resistance against deflection by the intermediate moveable component (not shown), but is the only design which is water- and dust-proof in both the equilibrium and active states.

FIG.27Ashows a schematic perspective view of a smartphone2700. The smartphone2700comprises one or more design features or functional features (such as antenna bands) provided around the smartphone. In the illustrated example, the smartphone2700comprises at least two such design features (e.g. antenna bands)2704,2708, which are located near the top and bottom edges of the smartphone (when held by a user in ‘portrait mode’). The front and back faces of the smartphone2700may be formed from glass, while the sides/edges of the smartphone2700may be formed from three pieces/components2702,2706and2710which may be moulded or otherwise formed as separate components and which are connected together in the manufacturing process. The three components2702,2706, and2710may be formed of aluminium, stainless steel, plastic or flexible/deformable glass. It will be understood that these are merely example materials. The three components are typically machined and then insert moulded into one piece, with the antenna bands provided between the sections. As shown, antenna band2704is located between components2702and2706(and may typically be moulded into components2702and2706), and antenna band2708is located between components2706and2710(and may be moulded into components2706and2710). In some cases, there is no gap (or significant gap) between the three components2702,2706and2710—there may be a seamless transition between the three components such that it appears that the edges of the smartphone (and possibly the entire smartphone) are formed from a single piece of material. In this instance, the smartphone may be gapless, particularly if there are no protruding mechanical buttons along the edges of the smartphone2700. Accordingly, the smartphone may achieve an Ingress Protection (IP) Rating of 67 or 68 indicating the device is dust-proof and water-proof to some standard. In some cases, there may be a small gap either side of each antenna band2704,2708of up to 20 μm for example, and in this instance the smartphone is not gapless. Accordingly, additional sealing techniques may be required to provide the smartphone with the required dust-proof and water-proof qualities, such as the sealing techniques described above.

FIG.27Bshows a schematic plan view of an edge of the smartphone ofFIG.27A, andFIGS.27C-Eshow schematic cross-sectional views of the profile of a button portion2706of the smartphone ofFIG.27A. The button portion2706may be used to deliver haptic feedback to a user of the smartphone. The length of the button portion2706may be long—for example, the button portion2706may be nearly as long as a long edge of the smartphone2700. A single haptic assembly/haptic actuator may not impart the required force to move the whole length of the button portion2706and thereby deliver an adequate haptic sensation to a user. Therefore, one or more haptic assemblies may be coupled to the button portion2706and arranged to deliver localised haptic feedback.

FIG.27Cshows how the button portion2706may be shaped to form a cantilever2712. The cantilever2712is adjacent to antenna band2704and the gap between the button portion2706and component2702. Accordingly, when a force is applied to the cantilever2712by a haptic actuator (as indicated by the arrow), the cantilever2712is able to move/tilt relative to the rest of the button portion2706and to the component2702. Accordingly, the haptic assembly makes use of an existing gap in the smartphone2700to enable movement of the cantilever2712to deliver a haptic sensation.

FIG.27Dshows how the button portion2706may be shaped to form a first cantilever2712and a second cantilever2714. The second cantilever2714is adjacent to antenna band2708and the gap between the button portion2706and component2710. The first and second cantilevers2712,2714may be separately actuated by individual haptic actuators to deliver haptic feedback at different positions along the button portion2706. In this way, localised haptic feedback may be delivered via button portion2706.

FIG.27Eshows how the button portion2706may be shaped to form a first cantilever2712, a second cantilever2714and a thin flexible portion2716. A further haptic actuator may be used to move the thin flexible portion2716to deliver haptic feedback at a point along the length of the button portion2706. Thus, by shaping the cross-sectional profile of the button portion2706it is possible to deliver haptic feedback at different points along the button portion2706. It will be understood that the number of points of haptic feedback on the button portion2706may depend on the length of the button portion2706.

FIG.28Ashows a schematic cross-sectional view of a part of a gapless haptic assembly2800which uses magnets and magnetic interaction to produce haptic feedback. The gapless haptic assembly2800comprises a housing2802, similar to that shown in for example,FIGS.23A and25. The housing2802comprises a contact surface which a user may touch to receive haptic feedback. The gapless haptic assembly2800comprises a first magnet or magnetic element2806, which may be fixedly connected to an internal surface of the housing2802, and specifically to an internally-located side of the contact surface. The first magnet2806may be a permanent magnet. As shown inFIG.28A, the north pole of the first magnet2806may be closest to the internal surface of the housing2802and the south pole is further away from the internal surface of the housing, however it will be understood that this is merely exemplary. The gapless haptic assembly2800comprises a second magnet2804. The second magnet2804is moveable relative to the housing2802and relative to the first magnet2806. The second magnet2804may be a permanent magnet. The second magnet2804is arranged such that the south pole faces the south pole of the first magnet2804. The second magnet2804is coupled to at least one SMA actuator wire2808. The at least one SMA actuator wire2808is coupled at one end to a static component (e.g. the housing2802itself), and at another end to the moveable second magnet2804. In an equilibrium state, the second magnet2804is at a distance from the first magnet2806such that the magnetic interaction between the two magnets is minimal/insignificant. When the at least one SMA actuator wire2808is heated and caused to contract, the second magnet2804is moved closer to the first magnet2806. As the like poles of the two magnets2804,2806are brought closer together, the movement of the second magnet2804forces the first magnet2806to be repelled away from the second magnet2804. This repulsion causes the movement of the housing2802(specifically the contact surface of the housing), which thereby causes a haptic sensation to be delivered.

FIG.28Bshows an alternative arrangement of the first magnet inFIG.28A. Here, the first magnet2806′ may be arranged such that the poles of the magnet are at an angle to the internal surface of the housing2802. This may help to reduce any undesired horizontal/sideways motion of the first magnet2806′ when the second magnet2804is moved into proximity with the first magnet2806′. Additionally or alternatively, one or more bearings (not shown) may be used to restrict the horizontal/sideways motion of the first magnet2806,2806′ within the housing.

The haptic assemblies shown inFIGS.28A and28Bmay further comprise a bias spring or other component (not shown) to oppose the effect of the at least one SMA actuator wire2808. The haptic assemblies may further comprise one or more endstops (not shown) in the housing to restrict movement of the second magnet2804and first magnet2806.

Many of the haptic assemblies described above use wedge-shaped components or inclined surfaces to transfer motion along one axis into motion along a second axis (e.g. ‘horizontal’/lateral motion to ‘vertical’ motion).FIGS.29A and29Bshow two gapless haptic assemblies which use alternative mechanisms to deliver haptic feedback.

FIG.29Ashows a cross-sectional view of a gapless haptic assembly2900comprising a material under compression. The haptic assembly2900may be incorporated into or otherwise provided along an edge of a smartphone or on a surface of a smartphone. The haptic assembly2900may be a provided as a standalone module that may be incorporated into an electronic device during manufacture. Alternatively, some or all of the components of haptic assembly2900may be integrally formed in an electronic device.

The haptic assembly2900may comprise a housing2906. In this case, the haptic assembly2900may be a module which is incorporated into an electronic device. Alternatively, the housing2906may be part of an electronic device (and not part of the haptic assembly) into which the components of the haptic assembly2900are incorporated. In this case, the electronic device may be more aesthetically pleasing to a user because the edge or surface of the electronic device where the haptic assembly2900is located may be substantially smooth and gap-free. This may allow an electronic device to be produced which has smooth edges/surfaces that do not have protruding buttons. Instead of having a visible, protruding button, the haptic assembly2900may provide haptic feedback when a user contacts (or is in the vicinity of) a ‘non-protruding button’ of the haptic assembly.

The housing2906(whether it is part of the haptic assembly2900or otherwise) comprises a (non-protruding) button portion2902. All of the edges of the button portion2902may be connected to the housing2906. However, the button portion2902may be thinner than the rest of the housing2906—this allows the button portion2902to move relative to the housing2906(as indicated by the arrow) when the haptic assembly2900is activated. In other words, the thickness of the button portion2902may provide the button portion2902with the flexibility to move relative to the housing2902. The button portion2902may be provided by machining, etching or half-etching the housing2902to remove material. The button portion2902comprises a contact surface. The contact surface may be substantially level with/flush with an external surface of the housing2902when the haptic assembly is in an equilibrium state.

The haptic assembly2900comprises an intermediate moveable element2904. The intermediate moveable element2904is coupled to at least one SMA actuator wire. The or each SMA actuator wire is coupled at one end to the housing2906and at another end to the intermediate moveable element2904. The haptic assembly2900may comprise a return spring/bias spring. The haptic assembly2900comprises a compliant or flexible material2908. The compliant material2908may be an elastomer, such as natural rubber, silicone rubber, thermoplastic polyurethane (TPU), neoprene rubber and polyurethane. It will be understood that is a non-exhaustive, non-limiting example list of materials. The compliant material2908is in contact with the intermediate moveable element2904and the button portion2902of the housing2906. When the haptic assembly2900is in the equilibrium (inactive) state, the intermediate moveable element2904exerts a force on the compliant material2908. Generally speaking, when the compliant material2908is compressed in one direction (e.g. by the intermediate moveable element2904), the compliant material2908expands in another direction. When the at least one SMA actuator wire is heated and contracts, the intermediate moveable element2904moves and the force exerted by the intermediate moveable element2904on the compliant material2908is reduced. This enables the compliant material2908to expand in the lateral direction (i.e. along the axis of movement of the intermediate moveable element2904).

The haptic assembly2900may function in a number of ways. For example, in one arrangement, in the equilibrium state, the compliant material2908may exert a force on the button portion2902which causes the button portion2902to bulge or be in a ‘raised’ position. In this case, when the haptic assembly2900is in the active state, the compliant material2908is able to expand in the lateral direction (i.e. along the axis of movement of the intermediate moveable element2904). This causes the button portion2902to become ‘unraised’, such that the button portion2902moves vertically ‘downward’ when the haptic assembly2900is activated. In an alternative arrangement, in the equilibrium state, the compliant material2908may exert a force on the button portion2902, and the button portion2902may exert an equal but opposite force on the compliant material2908. In this case, the button portion2902is substantially flush with/level with the housing2906in the equilibrium state. When the haptic assembly2900is in the active state, the force on the compliant material2908is reduced, but the force exerted by the button portion remains the same. Therefore, the button portion2902may form a dimple-shape when the haptic assembly is activated.

It will be understood that the arrangement of the intermediate moveable element and the compliant material may be changed so that the button portion2902moves vertically ‘upward’ when the haptic assembly2900is activated.

The haptic assembly2900may be advantageous because the button portion2902is part of the housing2906such that there is no gap between the button portion and the housing2906when the haptic assembly2900is integrated into device such as a smartphone. Thus, the haptic assembly2900is substantially water-proof and/or dust-proof.

Like many of the gapless haptic assemblies described herein, the haptic assembly2900may be modified such that it is used to move a button (e.g. a button of the type shown inFIG.1). Thus, the haptic assembly2900may be gapless, apparently gapless or have a visible gap, depending on other design criteria.FIG.29Bshows a cross-sectional view of the haptic assembly2900having a gap between the button2902′ and the housing.

FIG.29Cshows a cross-sectional view of a gapless haptic assembly2950comprising a piston. The haptic assembly2950may be incorporated into or otherwise provided along an edge of an electronic device or on a surface of a electronic device. The haptic assembly2950may be provided as a standalone module that may be incorporated into an electronic device during manufacture. Alternatively, some or all of the components of haptic assembly2950may be integrally formed in an electronic device.

The haptic assembly2950may comprise a housing2956. In this case, the haptic assembly2950may be a module which is incorporated into an electronic device. Alternatively, the housing2956may be part of an electronic device (and not part of the haptic assembly) into which the components of the haptic assembly2950are incorporated. In this case, the electronic device may be more aesthetically pleasing to a user because the edge or surface of the electronic device where the haptic assembly2950is located may be substantially smooth and gap-free. This may allow an electronic device to be produced which has smooth edges/surfaces that do not have protruding buttons. Instead of having a visible, protruding button, the haptic assembly2950may provide haptic feedback when a user contacts (or is in the vicinity of) a ‘non-protruding button’ of the haptic assembly.

The housing2956(whether it is part of the haptic assembly2950or otherwise) comprises a (non-protruding) button portion2952. All of the edges of the button portion2952may be connected to the housing2956. However, the button portion2952may be thinner than the rest of the housing2956—this allows the button portion2952to move relative to the housing2956(as indicated by the arrow) when the haptic assembly2950is activated. In other words, the thickness of the button portion2952may provide the button portion2952with the flexibility to move relative to the housing2952. The button portion2952may be provided by machining, etching or half-etching the housing2952to remove material. The button portion2952comprises a contact surface. The contact surface may be substantially level with/flush with an external surface of the housing2952when the haptic assembly is in an equilibrium state.

The haptic assembly2950comprises an intermediate moveable element2954. The intermediate moveable element2954is coupled to at least one SMA actuator wire. The or each SMA actuator wire is coupled at one end to the housing2956and at another end to the intermediate moveable element2954. The haptic assembly2900may comprise a return spring/bias spring. The haptic assembly2950comprises a piston2960and a fluid2958. The fluid2958may be an oil, mineral oil, silicone-based fluids, glycol-based fluids, water, gas, air, or an inert gas (e.g. nitrogen). It will be understood that is a non-exhaustive, non-limiting example list of materials. The piston2960is in contact with the button portion2952and the fluid2958. The fluid2958is in contact with the piston2960and the intermediate moveable element2954. When the haptic assembly2950is in the equilibrium (inactive) state, the intermediate moveable element2954exerts a force on the fluid2958, which in turn exerts a force on the piston2960. Thus, this haptic assembly2950uses a hydraulic mechanism to transfer the motion of the SMA actuator wire(s) to the button portion2952. When the at least one SMA actuator wire is heated and contracts, the intermediate moveable element2954moves and the force exerted by the intermediate moveable element2954on the fluid2958is reduced. This enables the fluid2958to expand in the lateral direction (i.e. along the axis of movement of the intermediate moveable element2954).

The haptic assembly2950may function in a number of ways. For example, in one arrangement, in the equilibrium state, the fluid2958may exert a force on the piston2960, which causes the button portion2952to bulge or be in a ‘raised’ position. In this case, when the haptic assembly2950is in the active state, the fluid2958is able to expand in the lateral direction (i.e. along the axis of movement of the intermediate moveable element2954). This causes the button portion2952to become ‘unraised’, such that the button portion2952moves vertically ‘downward’ when the haptic assembly2950is activated. In an alternative arrangement, in the equilibrium state, the fluid2958may exert a force on piston2960, and the button portion2952may exert an equal but opposite force on the piston2960. In this case, the button portion2952is substantially flush with/level with the housing2956in the equilibrium state. When the haptic assembly2950is in the active state, the force on the fluid2958and the piston2960is reduced, but the force exerted by the button portion2952remains the same. Therefore, the button portion2952may form a dimple-shape when the haptic assembly is activated.

FIG.29Dshows an alternative arrangement of the gapless haptic assembly ofFIG.29C, in which the direction of movement of the intermediate moveable element is reversed relative to the arrangement ofFIG.29C. In other words, when the SMA actuator wire is powered, the intermediate moveable element exerts a higher force on the fluid2958. In this case, the button portion2952moves vertically ‘upwards’ when the SMA actuator wire is powered and contracts.

The haptic assembly2950may be advantageous because the button portion2952is part of the housing2956such that there is no gap between the button portion and the housing2956when the haptic assembly2950is integrated into device such as a smartphone. Thus, the haptic assembly2950is substantially water-proof and/or dust-proof.

Like many of the gapless haptic assemblies described herein, the haptic assembly2950may be modified such that it is used to move a button (e.g. a button of the type shown inFIG.1). Thus, the haptic assembly2950may be gapless, apparently gapless or have a visible gap, depending on other design criteria.FIG.29Eshows a cross-sectional view of the haptic assembly2950having a gap between the button2952′ and the housing.

Thus, in embodiments of the haptic button assembly, the button and the housing may be integrally formed.

The button may comprise at least one free edge.

The button may be formed by etching or half-etching the housing.

The button may comprise at least one cantilever and the at least one intermediate moveable element is arranged to drive movement of the cantilever along the first axis.

The haptic button assembly may comprise a first magnetic element fixedly connected to the button, and wherein the intermediate moveable element may comprise a second magnetic element.

The haptic button assembly may comprise a compliant material provided between the button and the intermediate moveable element, wherein the intermediate moveable element may be arranged to drive movement of the compliant material along the first axis, and the movement of the compliant material drives movement of the button along the first axis.

The haptic button assembly may comprise a fluid and a moveable component, wherein the intermediate moveable element is arranged to drive movement of the fluid, the fluid is arranged to drive movement of the moveable component, and the moveable component drives movement of the button along the first axis.

In embodiments, the at least one intermediate moveable element may comprise: a first moveable arm fixedly connected at a first end to the button; a second moveable arm rotatably connected at a first end to a second end of the first moveable arm via a first hinge, and fixedly connected at a second end to the static component; a third moveable arm fixedly connected at a first end to the button; a fourth moveable arm rotatably connected at a first end to a second end of the third moveable arm via a second hinge, and fixedly connected at a second end to the static component; wherein the at least one SMA actuator wire is connected to the first and second hinges and arranged to drive movement of the intermediate moveable element in a first plane, thereby driving movement of the button in the first plane.

FIGS.30A and30Bshow schematic plan views of a device3000comprising a partly gapless haptic assembly in the equilibrium (inactive) and active states respectively. As mentioned above with reference toFIGS.27A to27E, it may be possible to take advantage of existing gaps and design features within a smartphone or other consumer electronic device, for example, when designing and integrating a haptic assembly into the device.FIGS.30A and30Bshow how a haptic assembly may be used to slide existing design features of a device3000, and thereby create a haptic sensation. The haptic assembly in this case may not convert horizontal/lateral motion into vertical motion—instead, the haptic assembly may simply be used to move a component of the device3000laterally.

The device3000comprises at least one moveable component which may be moved by a haptic assembly to deliver haptic feedback. In the illustrated example, the device3000comprises a first moveable component3002and a second moveable component3004. The device3000comprises one or more haptic assemblies (not shown), where each haptic assembly is used to move an individual moveable component. In the equilibrium state, the first and second moveable components3002,3004are flush against other components of the device3000, such that there is no discernible gap3006,3008and the device may be water- and/or dust-proof. In the active state, a haptic assembly may slide one of the moveable components3002,3004back and forth to generate haptic feedback. However, this causes a visible gap3006,3008to be formed while the moveable component is in motion. Thus, while the device3000is delivering haptic feedback, the device3000may not be water- and/or dust-proof. To provide water- and/or dust-proofing, the device3000may comprise an additional sealing mechanism, such as those described in International Patent Application No. PCT/GB2018/052923.

FIGS.31A and31Bshow schematic plan views of a device3100comprising an alternative partly gapless haptic assembly in the equilibrium (inactive) and active states respectively. As mentioned above with reference toFIGS.27A to27E, it may be possible to take advantage of existing gaps and design features within a smartphone or other consumer electronic device, for example, when designing and integrating a haptic assembly into the device.FIGS.31A and31Bshow how a haptic assembly may be used to slide existing design features of a device3100, and thereby create a haptic sensation. The haptic assembly in this case may not convert horizontal/lateral motion into vertical motion—instead, the haptic assembly may simply be used to move a component of the device3100laterally.

The device3100comprises at least one moveable component which may be moved by a haptic assembly to deliver haptic feedback. In the illustrated example, the device3100comprises a first moveable component3102and a second moveable component3104. The device3100comprises one or more haptic assemblies (not shown), where each haptic assembly is used to move an individual moveable component. In the equilibrium state, the first and second moveable components3102,3104are flush against each other, such that there is no discernible gap between the two components and the device3100may be water- and/or dust-proof. In the active state, a haptic assembly may slide one of the moveable components3102,3104back and forth to generate haptic feedback. However, this causes a gap3106to be formed between the two moveable components while the or each moveable component is in motion. Thus, while the device3100is delivering haptic feedback, the device3100may not be water- and/or dust-proof. To provide water- and/or dust-proofing, the device3000may comprise an additional sealing mechanism, such as those described in International Patent Application No. PCT/GB2018/052923.

Thus, in embodiments, the at least one SMA actuator wire may be arranged to drive movement of the intermediate moveable component along an axis parallel to the axis of the at least one SMA actuator wire; and the at least one intermediate moveable element may be arranged to drive movement of the moveable component along an axis parallel to the axis of the at least one SMA actuator wire. In other words, the intermediate moveable component and the moveable component may move in the same direction as the contraction and expansion of the at least one SMA actuator wire (horizontally/laterally).

FIG.32shows a schematic plan view of a device3200comprising a further alternative partly gapless haptic assembly in the active state. Here, a whole side or edge of the device3200may be a moveable component3202which is moveable to deliver haptic feedback. In this case, a visible gap may only appear when the moveable component3202is being moved to deliver haptic feedback. One or more haptic assemblies may be provided to move the moveable component3202vertically upwards.

In each of the embodiments shown inFIGS.30to32, additional sealing mechanisms may be provided to ensure the device is water-proof and/or dust-proof in use. For example, seals between the moveable component and the haptic assembly may be provided to prevent fluid and/or dust ingress into the body of the device. Thus, even if fluid/dust gets into the gap while the haptic assembly is active, it may not be able to move any further into the body of the device.

While the importance of providing a dust- and/or water-proof device has been discussed, it will be understood that there are a number of applications where this is not required. For example, while compliance with the Ingress Protection (IP) Rating of 67 or 68 may be important for smartphones, smartwatches and some other wearable devices, it may not be important for gaming controllers, domestic appliances and within vehicles, for example. Therefore, in some cases, it may not be necessary for the haptic assembly to be gapless or fully sealed both in an equilibrium and active state.

It will be understood that any of the gapless haptic assemblies described above may be modified such that it they can be used to move a button (e.g. a button of the type shown inFIG.1). That is, the gapless haptic assemblies may be modified to be apparently gapless or have a visible gap.

Those skilled in the art will appreciate that while the foregoing has described what is considered to be the best mode and where appropriate other modes of performing present techniques, the present techniques should not be limited to the specific configurations and methods disclosed in this description of the preferred embodiment. Those skilled in the art will recognise that present techniques have a broad range of applications, and that the embodiments may take a wide range of modifications without departing from any inventive concept as defined in the appended claims.