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Title:
PLANAR-SHAPED VIBROTACTILE ACTUATOR
Document Type and Number:
WIPO Patent Application WO/2016/154752
Kind Code:
A1
Abstract:
There is described herein a device comprising a housing having a top housing surface and a bottom housing surface, and at least one inner wall defining a cavity. A magnetic mass is suspended within the cavity. The magnetic mass creates magnetic field lines that leave the north magnetic pole of the mass and enter the south magnetic pole of the mass. A flexible support is laterally mounted to the mass to suspend the mass in the cavity while allowing it to be displaced vertically. A coil structure comprising one or more coils is provided in the housing and surrounds the mass, for carrying a current to intersect the magnetic field and generate a force to displace the mass vertically in the cavity.

Inventors:
YAO, Hsin-Yun (147 Frontenac EastSaint-Bruno-de-Montarville, Québec J3V 6J3, J3V 6J3, CA)
CHENARD, Jean-Samuel (147 Frontenac EastSaint-Bruno-de-Montarville, Québec J3V 6J3, J3V 6J3, CA)
PASQUERO, Jerome (4550 Cumberland, Montreal, Québec H4B 2L4, H4B 2L4, CA)
Application Number:
CA2016/050368
Publication Date:
October 06, 2016
Filing Date:
March 30, 2016
Export Citation:
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Assignee:
7725965 CANADA INC. (147 Frontenac East, Saint-Bruno-de-Montarville, Québec J3V 6J3, J3V 6J3, CA)
International Classes:
H02K33/02; G06F3/01
Foreign References:
US8807169B22014-08-19
US6570994B12003-05-27
US5809157A1998-09-15
Attorney, Agent or Firm:
NORTON ROSE FULBRIGHT CANADA LLP/S.E.N.C.R.L., S.R.L. (Suite 2500, 1 Place Ville-MarieMontréal, Québec H3B 1R1, H3B 1R1, CA)
Download PDF:
Claims:
CLAIMS:

1 . A device comprising:

a first housing having a top housing surface and a bottom housing surface, and at least one inner wall defining a cavity;

a first magnetic mass suspended within the cavity and having a first mass surface adjacent to and spaced from the top housing surface and a second mass surface adjacent to and spaced from the bottom housing surface, the magnetic mass having a first pole at the first mass surface, a second pole opposite from the first pole at the second mass surface for generating a magnetic field extending between the first pole and the second pole;

a first flexible support at least laterally mounted to the magnetic mass intermediate to the first mass surface and the second mass surface to suspend the magnetic mass in the cavity while allowing a vertical displacement thereof; and a first coil structure in the housing and surrounding the mass, for carrying a current to intersect the magnetic field and generate a force to displace the magnetic mass vertically in the cavity.

2. The device of claim 1 , wherein the first magnetic mass comprises at least one permanent magnet.

3. The device of claim 2, wherein the first flexible support comprises a suspension membrane holding the first magnetic mass and attached to the at least one inner wall of the first housing.

4. The device of claim 3, wherein the at least one permanent magnet comprises a first permanent magnet and a second permanent magnet held together by attracting magnetic forces, and the suspension membrane is retained between the first permanent magnet and the second permanent magnet.

5. The device of any one of claims 1 to 4, wherein the first coil structure is embedded within a coil supporting member.

6. The device of claim 5, wherein the coil supporting member comprises at least one printed circuit board and the first coil structure is etched into the at least one printed circuit board.

7. The device of claim 6, wherein the first housing is formed at least in part by the at least one printed circuit board.

8. The device of claim 7, wherein the at least one printed circuit board comprises a plurality of stacked printed circuit boards, each one of the printed circuit boards comprising an etched pattern spiraling one of inwards and outwards, a connecting entry point at a beginning of the pattern, and a connecting exit point at an end of the pattern, and wherein each one of the printed circuit boards is rotated relative to a preceding board to create a continuous helicoidal path for current to flow through the first coil structure.

9. The device of any one of claims 1 to 8, wherein the first coil structure comprises at least two separate coil sections provided in a same plane and positioned at a given angular position around the first magnetic mass.

10. The device of claim 9, wherein at least one of the at least two coil sections comprises at least a first coil portion positioned a first radial distance from the first magnetic mass and at least a second coil portion positioned a second radial distance from the first magnetic mass, the first radial distance being greater than the second radial distance.

1 1 . The device of any one of claims 1 to 10, wherein at least one of the top housing surface and the bottom housing surface is made of flexible material.

12. The device of any one of claims 1 to 1 1 , further comprising at least one magnetic body inside the cavity affixed to at least one of the top housing surface and the bottom housing surface, spaced from the magnetic mass and having a same polarity at a mass facing surface as a polarity of a body facing surface of the mass.

13. The device of any one of claims 1 to 12, further comprising at least one nonmagnetic body positioned between and in contact with the magnetic mass and the top housing surface or the bottom housing surface.

14. The device of any one of claims 1 to 13, further comprising a second housing, a second magnetic mass, a second flexible support, and a second coil structure arranged similarly to the first housing, the first magnetic mass, the first flexible support, and the first coil structure, wherein the first housing and the second housing are retained together by an attachment member.

15. A method for assembling a device, the method comprising:

stacking a plurality of coil supporting members having at least one coil structure embedded therein, the coil supporting members defining a cavity;

retaining a flexible support between a first set of the coil supporting members and a second set of the coil supporting members;

mounting a magnetic mass to the flexible support to suspend the magnetic mass within the cavity while allowing a vertical displacement thereof; and

closing the cavity with a top housing surface and a bottom housing surface at respective ends thereof to form a closed housing.

16. The method of claim 15, wherein stacking a plurality of coil supporting members comprises stacking a plurality of printed circuit boards having the at least one coil structure etched thereon.

17. The method of claims 15 or 16, wherein retaining the flexible support comprises providing spacers between the first set of coil supporting members and the flexible support and between the section set of coil supporting members and the flexible support.

18. The method of any one of claims 15 to 17, wherein mounting a magnetic mass comprises providing a first permanent magnet on a top surface of the flexible support and a second permanent magnet on a bottom surface of the flexible support, the first permanent magnet and the second permanent magnet held together by attracting magnetic forces.

19. The method of any one of claims 15 to 17, wherein mounting a magnetic mass comprises inserting the magnetic mass into an aperture of the flexible support sized to receive the magnetic mass.

20. The method of any one of claims 15 to 19, further comprising attaching the closed housing to another housing having a same arrangement of coil supporting members, coil structure, flexible support, and magnetic mass.

Description:
PLANAR-SHAPED VIBROTACTILE ACTUATOR

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001 ] The present application claims priority under 35 U.S.C. 1 19(e) of United States Provisional Patent Application No. 62/139,837 filed on March 30, 3015, the contents of which are hereby incorporated by reference in their entirety.

TECHNICAL FIELD

[0002] The present disclosure relates to the field of vibrotactile actuators and, in particular, to planar-shaped vibrotactile actuators.

BACKGROUND OF THE ART

[0003] Haptic technology provides tactile feedback that recreates the sense of touch on the hand or other parts of the body of a user, by applying forces, vibrations, or motions thereto. Haptic vibrations sent to the skin can emulate surface textures and characteristic. In addition, lateral tilt (pitch and roll) of the surface creates the perceptual illusion of curvature.

[0004] Vibrotactile actuators are widely used in consumer devices for conveying haptic sensations. Some examples include mobile phones, surgical tools, and video game controllers. In order for haptic sensations to be optimally transmitted to the user, a proper contact needs to be maintained between the body and the device. The better the contact, the more enhanced the sensation is to the user. The most common vibration motors are the eccentric rotation mass vibration motors. They come in a cylindrical shape and cannot be easily attached to the skin. Some applications for vibrotactile actuators involve handheld devices, such as probes or other similarly-shaped tools. Therefore, eccentric rotation mass vibration motors are well suited for these applications, but ill-suited for other applications. [0005] As the number of potential applications for vibrotactile actuators increases, there is a need to provide designs that can maintain good contact with parts of the body other than a hand.

SUMMARY

[0006] There is described herein a device comprising a housing having a top housing surface and a bottom housing surface, and at least one inner wall defining a cavity. A magnetic mass is suspended within the cavity. The magnetic mass creates magnetic field lines that leave the north magnetic pole of the mass and enter the south magnetic pole of the mass. A flexible support is laterally mounted to the mass to suspend the mass in the cavity while allowing it to be displaced vertically. A coil structure comprising one or more coils is provided in the housing and surrounds the mass, for carrying a current to intersect the magnetic field and generate a force to displace the mass vertically in the cavity.

[0007] In accordance with a first broad aspect, there is provided a device comprising: a first housing having a top housing surface and a bottom housing surface, and at least one inner wall defining a cavity; a first magnetic mass suspended within the cavity and having a first mass surface adjacent to and spaced from the top housing surface and a second mass surface adjacent to and spaced from the bottom housing surface, the magnetic mass having a first pole at the first mass surface, a second pole opposite from the first pole at the second mass surface for generating a magnetic field extending between the first pole and the second pole; a first flexible support at least laterally mounted to the magnetic mass intermediate to the first mass surface and the second mass surface to suspend the magnetic mass in the cavity while allowing a vertical displacement thereof; and a first coil structure in the housing and surrounding the mass, for carrying a current to intersect the magnetic field and generate a force to displace the magnetic mass vertically in the cavity. [0008] In some embodiments, the magnetic mass is at least one permanent magnet. The magnetic mass may be composed of a first permanent magnet and a second permanent magnet held together by attracting magnetic forces, and the flexible support is retained between the first permanent magnet and the second permanent magnet.

[0009] In some embodiments, the lateral support comprises any one of a suspension membrane, a silicone rubber slab, an injected gel, and a castable urethane foam.

[0010] In some embodiments, the coil structure is embedded within a coil supporting member. The coil supporting member may be at least one printed circuit board and the coil structure is etched into the at least printed circuit board. The housing may be formed at least in part by the at least one printed circuit boards.

[001 1 ] In some embodiments, the at least one printed circuit board comprises a plurality of stacked printed circuit boards, each one of the printed circuit boards comprising an etched pattern spiraling one of inwards and outwards, a connecting entry point at a beginning of the pattern, and a connecting exit point at the end of the pattern, and wherein each one of the printed circuit boards is rotated relative to a preceding board to create a continuous helicoidal path for current to flow through the coil structure.

[0012] In some embodiments, the coil structure is composed of two or more separate coil sections disposed along a same plane to allow for possible lateral tilts in pitch and roll of the mass, to create moment or rotation on the device, or to statically tilt the top surface directly above the mass. In some embodiments, the coil sections comprise at least a first coil portion positioned a first radial distance from the first magnetic mass and at least a second coil portion positioned a second radial distance from the first magnetic mass, the first radial distance being greater than the second radial distance. [0013] In some embodiments, at least one of the top housing surface and the bottom housing surface is made of flexible material.

[0014] In some embodiments, the device further comprises at least one magnetic body inside the cavity affixed to at least one of the top housing surface and the bottom housing surface, spaced from the magnetic mass and having a same polarity at a mass facing surface as a polarity of a body facing surface of the mass.

[0015] In some embodiments, the device further comprises at least one nonmagnetic body positioned between and in contact with the magnetic mass and the top housing surface or the bottom housing surface.

[0016] In some embodiments, the device further comprises a second housing, a second magnetic mass, a second flexible support, and a second coil structure arranged similarly to the first housing, the first magnetic mass, the first flexible support, and the first coil structure, wherein the first housing and the second housing are retained together by an attachment member.

[0017] In some embodiments, underneath the top surface or above the bottom surface of the housing inside the cavity, there is provided another body that generates a magnetic field, such as a permanent magnet or an electromagnet. The additional magnetic field is of a same polarity as the polarity of the surface of the mass it is adjacent to in order to increase the density of the magnetic field that traverses the coil structure.

[0018] In some embodiment, ferromagnetic material is added to the outside wall of the coil structure, in a way to condense the magnetic field lines that traverse the coil structure by virtue of its higher magnetic permeability.

[0019] In accordance with another broad aspect, there is provided a method for assembling a device. The method comprises stacking a plurality of coil supporting members having at least one coil structure embedded therein, the coil supporting members defining a cavity; retaining a flexible support between a first set of the coil supporting members and a second set of the coil supporting members; mounting a magnetic mass to the flexible support to suspend the magnetic mass within the cavity while allowing a vertical displacement thereof; and closing the cavity with a top housing surface and a bottom housing surface at respective ends thereof to form a closed housing.

[0020] In some embodiments, stacking a plurality of coil supporting members comprises stacking a plurality of printed circuit boards having the at least one coil structure etched thereon.

[0021 ] In some embodiments, retaining the flexible support comprises providing spacers between the first set of coil supporting members and the flexible support and between the section set of coil supporting members and the flexible support.

[0022] In some embodiments, mounting a magnetic mass comprises providing a first permanent magnet on a top surface of the flexible support and a second permanent magnet on a bottom surface of the flexible support, the first permanent magnet and the second permanent magnet held together by attracting magnetic forces.

[0023] In some embodiments, mounting a magnetic mass comprises inserting the magnetic mass into an aperture of the flexible support sized to receive the magnetic mass.

[0024] In some embodiments, the method further comprises attaching the closed housing to another housing having a same arrangement of coil supporting members, coil structure, flexible support, and magnetic mass. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Further features and advantages of the present invention will become apparent from the following detailed description, taken in combination with the appended drawings, in which:

[0026] Fig. 1 a is a cross-sectional view of an exemplary embodiment of a vibrotactile actuator with a suspension membrane as flexible support;

[0027] Fig. 1 b is a cross-sectional view of an exemplary embodiment of a vibrotactile actuator with a slab of elastomer material as flexible support;

[0028] Fig. 1 c is a cross-section view of an exemplary embodiment of a vibrotactile actuator with a cavity-filling gel or foam as flexible support;

[0029] Fig. 1 d is a cross-section view of an exemplary embodiment of a vibrotactile actuator with a cavity-filling gel or foam as flexible support and a void above and below the mass;

[0030] Fig. 2a illustrates an exemplary embodiment for attaching a mass to a suspension membrane;

[0031 ] Fig. 2b illustrates an exemplary embodiment for attaching a two-part mass to a suspension membrane;

[0032] Fig. 2c illustrates an exemplary embodiment for attaching a three-part mass to two suspension membranes;

[0033] Fig. 3 illustrates an exemplary embodiment for an enhanced magnetic field density;

[0034] Fig. 4 is a cross-sectional view of an exemplary embodiment of the vibrotactile actuator with stacks of printed circuit boards (PCBs) acting as coil support members; [0035] Fig. 5 is an exploded view of a plurality of PCB layers showing an interconnection;

[0036] Fig. 6 is a schematic illustration of a coil section for applying tilting to the mass, in accordance with one embodiment;

[0037] Figs. 7A to 7D are top views of examples of layers having one or more coil section positioned to applying tilting to the mass;

[0038] Fig. 8 is a cross-sectional view of an exemplary embodiment of a multi-level vibrotactile actuator; and

[0039] Fig. 9 illustrates and exemplary embodiment of the vibrotactile actuator with a non-magnetic material inside the housing.

[0040] It will be noted that throughout the appended drawings, like features are identified by like reference numerals.

DETAILED DESCRIPTION

[0041 ] Referring to the figures there are illustrated exemplary embodiments of a vibrotactile actuator device 100. The design allows the device 100 to maintain proper contact with another surface, such as a body part. The design is well suited for applications involving wearable haptics, as the device 100 may be easily integrated into fabrics or textiles. The design may also be used for other applications, such as providing tactile feedback in devices having small and/or thin form factors. Some examples include tactile electronic displays, simulators, and game controllers or virtual reality systems. Other suitable applications will be readily understood by those skilled in the art.

[0042] As shown in figure 1 a, a housing 102 comprises a top housing surface 104a and a bottom housing surface 104b. The surfaces 104a, 104b may be planar or they may comprise a non-zero curvature, depending on the application and the body part with which a respective surface is to be mated. The shape of the housing 102 may take various forms, such as square, rectangular, cylindrical, and other geometries. The housing 102 may also be of a non-symmetrical and/or a non- regular shape, such as having its top surface 104a planar and its bottom surface 104b curved. The housing 102 has at least one inner wall 104c that defines a cavity 105 in which a magnetic mass 106 is suspended. The mass 106 has a first mass surface 107a adjacent to and spaced from the top housing surface 104a and a second mass surface 107b adjacent to and spaced from the bottom housing surface 104b. The mass 106 is spaced from the top and bottom surfaces 104a, 104b of the housing 102 so as to allow a vertical displacement of the mass 106 within the cavity 105, as will be explained in more detail below. In some embodiments, the top and/or the bottom housing surfaces are made of flexible material such as neoprene, latex rubber, silicone, or urethane foam to create a surface that can render precisely the desired haptic stimulation when in contact with the skin.

[0043] The magnetic mass 106 may be composed of at least one permanent magnet having a first pole at the first mass surface 107a and a second pole opposite from the first pole at the second mass surface 107b. A magnetic field 109 generated by the permanent magnet extends between the first pole and the second pole. Note that while the pole at the first mass surface 107a is shown to be a north (N) pole and the pole at the second mass surface 107b is shown to be a south (S) pole, the N pole may be provided at the second mass surface 107b and the S pole may be provided at the first mass surface 107a. The mass 106 may be of various shapes, such as but not limited to cylindrical and rectangular.

[0044] The mass 106 is suspended within the cavity 105 by a flexible support mounted laterally thereto, which may take many forms as illustrated in figures 1 a, 1 b, 1 c, and 1 d. The flexible support retains the mass by its sides and suspends it within the cavity 105 while allowing it to move vertically within the cavity 105. In some embodiments, and as illustrated in figure 1 a, the flexible support comprises a suspension membrane 108a which spans the cavity 105 and attaches to the inner wall 104c. The membrane 108a may be made of any material that can deform under stress and return to its previous size and shape without permanent deformation. Some examples are synthetic rubbers such as neoprene and silicone, other polymer-based materials having similar properties, and any other soft or semi-rigid membrane with properties similar to the diaphragm of a loudspeaker. The membrane 108a may attach to the inner wall 104c at various attachment points or at it may be attached along its entire periphery. For example, the membrane 108a may attach to the inner wall 104c at two, three, four, or more attachment points evenly spaced along its periphery such that the mass 106 is held substantially level within the cavity 105. The membrane 108a may be attached to the inner wall 104c using various means, such as adhesives, attachment pins, retaining members, and others. In some embodiments, the housing 102 may be constructed concurrently with the membrane 108a such that the attachment points of the membrane 108a are embedded in the housing walls at the time of manufacture.

[0045] The membrane 108a may be mounted to the mass 106 in various ways. Two such examples are illustrated in figures 2a and 2b. In figure 2a, the membrane 108a is provided with an aperture 202 that can receive the mass 106. The membrane 108a may, for example, be affixed to the mass 106 along the perimeter of the aperture 202 using an adhesive such as glue, cement, or paste. Any adhesive compatible with the membrane material and/or magnet coating may be used. Alternatively, the aperture 202 may be sized and shaped to allow the mass 106 to fit snugly therein without the need for any adhesive. The material of the membrane 108a may allow the aperture 202 to be expanded in order to insert the mass 106 therein and when released, the aperture 202 may contract in order to retain the mass 106. An adhesive may also be used in combination with the aperture 202 in order to ensure the mass 106 is fixedly retained within the aperture 202.

[0046] In figure 2b, the mass 106 is composed of a first mass portion 204a and a second mass portion 204b. The first mass portion 204a is provided on a top surface 206a of the membrane 108a while the second mass portion 204b is provided on a bottom surface 206b of the membrane 108a. In some embodiments, the first and second mass portions 204a, 204b are affixed to the top and bottom surfaces 206a, 206b, respectively, using an adhesive. Alternatively, the first and second mass portions 204a, 204b are each permanent magnets and the membrane 108a is held between the magnets by attracting magnetic forces. For example, the first mass portion 204a may be a first permanent magnet having a N pole at a top surface 208a and a S pole at a bottom surface 208b, and the second mass portion 204b may be a second permanent magnet having a S pole at a top surface 210a and a N pole at a bottom surface 210b. The attracting forces between the S pole at the bottom surface 208b of the first permanent magnet and the N pole at the top surface 210a of the second permanent magnet may be used to retain the suspension membrane 108a there between. An adhesive may also be used in combination with the first permanent magnet and second permanent magnet in order to ensure that the membrane 108a is fixedly retained between the first mass portion 204a and the second mass portion 204b. Other embodiments may also be used that involve more masses 106 and more membranes 108, stacked together. One such example is illustrated in figure 2c, whereby three masses 106 are stacked between two membranes 108a. Each mass 106 may be attracted to an adjacent mass by a pole of opposing polarity.

[0047] Referring to figure 1 b, in some embodiments, the flexible support comprises one or more slabs 108b of an elastomer or sponge-like material. One such example is silicone rubber. The silicone rubber may be open cell or closed cell, depending on the application and the desired damping characteristics. Another example is a viscoelastic urethane polymer such as Sorbothane . The mass 106 may be coated with glue before being inserted into a hole cut in the slab 108b. Alternatively, two slabs 108b are provided, one on each side of the mass 106. The mass 106 may be affixed to the slabs 108b using an adhesive or another fixation means.

[0048] Referring to figure 1 c, in some embodiments, the flexible support comprises a soft silicone gel 108c with which the cavity 105 is filled. The mass 106 is thus suspended in the gel 108c, which is a jelly-like substance, and retains its ability to displace vertically upon the application of a vertical force. The entire cavity 105 may be filled with the gel 108c. Alternatively, and as illustrated in figure 1 d, spaces 120 directly above and below the mass 106 may be kept empty so as to act as a pressure relief chamber. The gel 108c may be ultra-violet (UV) curable or not. Alternatively, the cavity 105 may be filled with castable urethane foam, such as FlexFoam-iT™. Other materials having similar properties to encase the mass 106 in order to provide lateral support while allowing vertical displacement may also be used.

[0049] Referring back to figure 1 a, a coil structure 1 12a, 1 12b, 1 12c, 1 12d (collectively referred to as 1 12) is provided in the housing 102 and surrounds the mass 106 such that the magnetic field 109 intersects the coil structure 1 12 at a substantially right angle. When a current flows through the coil structure 1 12, it interacts with the magnetic field 109 to create a Lorentz force 1 10 in a direction perpendicular to the first mass surface 107a and the second mass surface 107b. The mass 106 moves vertically either towards the top housing surface 104a or the bottom housing surface 104b of the housing 102, depending on the direction of the current. When an alternating current (AC) is used, a reciprocating motion is caused, hence creating vibration. Depending on the force 1 10 acting on the mass 106, the actuator 100 may generate small vibrations or large vibrations. [0050] The coil structure 1 12 is disposed in the housing 102 to capture the magnetic field lines 109 perpendicular to the direction of the electric current. Obeying Lorentz's Law, the resulting force 1 10 is perpendicular to both the direction of the current and the magnetic field 109. As the force 1 10 is dependent on the current density through the coil structure 1 12 and the magnitude of the magnetic field 109, the force 1 10 may be increased or decreased by modulating either one or both of these two parameters. The magnitude of the magnetic field may be varied by sizing the magnet accordingly, and/or by selecting materials from which the magnet is made. Some exemplary materials for the permanent magnet are alloys of rare earth elements (e.g. neodymium and samarium-cobalt), ferrites, and alnico.

[0051 ] As per figure 3, the density of the magnetic field that traverses the coil structure may also be increased by adding another body inside the housing that generates a magnetic field. In this example, another magnetic body 220 is provided underneath the top housing surface 104a so as to generate a magnetic field 222 that will be added to the magnetic field 109 generated by the mass 106. This additional body 220 may be a permanent magnet, an electromagnet, or any other type of magnet. The density of the overall magnetic field interacting with the current in coil structure 1 12c having been increased, the generated force 10 will also be increased. When placed on the top or bottom housing surfaces 104a, 104b, the body 220 has a polarity at a mass facing surface 221 that is the same as the polarity of the mass surface 107a it is facing, i.e. the body facing surface, so as to create repulsing magnetic fields to increase the density of the magnetic field lines at the position where coil structure 1 12c is. One or more additional bodies 220 may be provided inside the cavity 105, on the top surface 104a, the bottom surface 104b, or any of the inner walls 104c. They are positioned to ensure that any generated magnetic fields 222 traverse at least one portion of the coil structure 1 12. Also alternatively, or in combination therewith, ferromagnetic material may be added to the inside or outside wall(s) of the housing 102, in a way to condense the magnetic field lines that traverse the coil structure 1 12. Such material may take the form of rods, bars, or layers of ferromagnetic material that attract the magnetic field lines and thus concentrate them in a given area, namely in one or more of the coil structures 1 12a, 1 12b, 1 12c, 1 12d.

[0052] Current density may be varied by having more or less loops of coil as part of the coil structure 1 12. Figure 1 a illustrates two loops, a first loop formed by coil portion 1 12a coming out of the sheet and coil portion 1 12c going into the sheet, and a second loop formed by coil portion 1 12b going into the sheet and coil portion 1 12d coming out of the sheet. The first loop 1 12a, 1 12c and second loop 1 12b, 1 12d may be part of separate windings that are not connected together, or they may be two loops in a same winding. There may be only a single loop forming a single winding, placed either at the top or the bottom of the housing 102 to intersect the magnetic field 109 at a substantially right angle. The force 1 10 to which the mass 106 is subjected would thus be lower than if more loops and/or more windings were provided. In some embodiments, the coil structure 1 12 comprises a winding having a plurality of loops that span a large portion of the housing 102, from top to bottom.

[0053] The coil structure 1 12 may be free standing or it may be embedded in one or more coil supporting members. The coil supporting member(s) may be made of any type of material that can retain each loop of the coil structure 1 12 in a desired position without preventing the magnetic field 109 from reaching the coil. For example, a foam, rubber, or plastic insert may be designed to fit inside the housing 102 and have one or more cutout portions that follow the trajectory of the coil structure 1 12, whereby the coil structure 1 12 is provided inside the cutout portions. A substantially central aperture may be provided in the insert to make room for the mass 106 in the cavity 105.

[0054] In some embodiments, the coil supporting member comprises one or more printed circuit boards (PCBs) into which the coil structure 1 12 is etched. The PCBs may be inserted inside the housing 102, or they may themselves form the housing structure, in whole or in part. For example, and as illustrated in figure 4, a plurality of PCB layers 304a-304h may be stacked and coils inside each layer may be connected together to conduct electricity. The PCB layers 304a-304h may be separated into two separate stacks, thereby forming a top portion 303a and a bottom portion 303b. Each PCB layer 304a-304h may be a single board, or multiple layers may together form a board. For example, the top portion 303a may be composed of a 4-layer PCB, two 2-layer PCBs, or four single-layer PCBs. In some embodiments, only the top portion 303a or the bottom portion 303b is provided as a stack of etched PCB layers. For example, the bottom portion 303b may be formed of plastic material and have a purely structural purpose while the top portion 303a is formed of etched PCB layers having dual purpose, namely as supporting members for the coil structure 1 12 and as the mechanical structure of the housing 102.

[0055] One or more spacers 306 may be provided between the top portion 303a layers and the bottom portion 303b layers to retain the suspension membrane 108a. The spacers 306 may themselves be PCBs, or an alternate material such as plastic. The stacked PCB layers 304a-304h each have a substantially central aperture 308 (see figure 5) to form the cavity 105 and receive the mass 106 therein. The aperture 308 may be circular, square, rectangular, oval, etc. A top layer 302a and a bottom layer 302b may be provided whole (i.e. without a cavity) to seal the device 100. Top and bottom layers 302a, 302b may themselves be PCB layers with etched coil patterns. Alternatively, the coil structure 1 12 may be fully contained within top portion 303a and/or bottom portion 303b layers. In some embodiments, additional electronic circuitry may be provided in the top layer 302a and/or bottom layer 302b. For example, sensing circuitry to locate the position of the mass 106 may be provided. Drive electronics may also be provided to make the device 100 fully self-contained. The use of PCB layers as support members provides a certain flexibility to incorporate custom circuitry into the device 100. [0056] Figure 5 presents an exploded view of the top portion 303a layers to illustrate one manner in which the connections between layers may be made. Each layer 304a-304d has an electrical connecting entry point 305a on a top surface and an electrical connecting exit point 305b on a bottom surface to connect with the electrical connecting entry and exit points 305a, 305b of a neighboring PCB. For example, the electrical connecting entry point 305b on the bottom surface of layer 304a connects to the electrical connecting exit point 305a on the top surface of layer 304b. In this example, the entry points 305a and exit points 305b are provided 90 degrees apart on each respective layer, and each layer is rotated 90 degrees relative to the preceding layer in the stack. Each layer contributes to the coil structure 1 12 with an etched pattern spiraling inwardly or outwardly, depending on the layer.

[0057] The angle between the entry points 305a and exit points 305b may be anywhere between 0 and 360 degrees, including but not limited to 30 degrees, 45 degrees, 60 degrees, 90 degrees, and 180 degrees. The angle will dictate by how much the succeeding layer is rotated. The angle may be used to determine how many layers are needed to form a coil structure 1 12 of at least one loop. For example, if a loop is represented by 360 degrees and the entry and exit points are 90 degrees apart, then 4 layers are needed to obtain 360 degrees of coil. Similarly, if the entry and exit points 305a, 305b are 30 degrees apart, then 12 layers are needed to form 360 degrees of coil. The entry and exit points 305a, 305b may be soldered together by heating up the entire stack (reflow soldering), or through vias on the PCBs.

[0058] In some embodiments, the device 100 may be constructed to allow tilting of the mass 106 by applying a force to only a portion thereof. This may be done, for example, using two or more separate coil sections in a given plane of the device, and selectively applying current to the coil sections. In some embodiments, one or more of the coil sections is configured so as to have some portions of the coil section positioned closer to the mass 106 while other portions of the coil section are farther away from the mass 106. An example is illustrated in figure 6. The coil section 600 is composed of a first portion 604a having current 602a flowing therethrough and a second portion 604b having current 602b flowing therethrough. As first portion 604a is farther away from the mass 106 than second portion 604b, the current 602a will generate a force that is weaker than a force generated by current 602b. Note that third portion 604c and fourth portion 604d do not contribute to the main desired movement of the mass 106.

[0059] Two or more coil sections 600 may be used to apply tilting points to the mass 106. Figure 7a illustrates four coil sections 600, positioned equidistantly around the aperture 308 in which the mass 106 will be provided. An entry point 305a and exit point 305b is provided for each coil section 600. This configuration allows selective control of the tilting of the mass by flowing current through only one, two, or three of the four coil sections 600. Applying current through all four coil sections 600 applies a force that is evenly distributed across the mass 106. Figure 7b illustrates six coil sections 600 distributed evenly around the aperture 308. This provides more tilting points on the mass 106, as different combinations of activated and inactivated coil sections 600 may be used.

[0060] While the coil sections 600 are shown as evenly spaced around the aperture 308, they may also be positioned unevenly or unsymmetrically, as desired. In addition, other configurations may be used for the coil sections 600, such as that illustrated in figures 7c and 7d. Figure 7c illustrates four coil sections 600 each comprising a single coil portion with an entry point 305a and an exit point 305b at each end thereof. Figure 7d illustrates two coil sections 600 each comprising multiple coil portions and having an entry point 305a and an exit point 305b at each end thereof.

[0061 ] In order to tilt the mass 106, each coil section 600 is positioned at a given angular position of the mass 106. By sending different electrical signal patterns through the various coil sections 600, control is exerted on the mass 106 so as to apply tilting forces dynamically. This allows the generation of the perceptual haptic cue of curvature.

[0062] In some embodiments, the PCB layers 304a-304h may be manufactured to be identical or in repeated groups. Identical PCBs may be panelized to reduce cost and manufacturing throughput. The assembly may be done either individually, or with continuous panels. Whole-panel assembly may be achieved by stacking a number of panels together, rotating each panel by a given amount, and using tooling holes for array alignment. A whole panel of PCBs may be assembled with only one assembly setup, increasing the efficiency by a factor of N, N corresponding to the number of devices for each PCB panel. Each layer in the panel assembly may have individual routing cuts or mouse bites (i.e. holes in the PCB material) to facilitate depanelization. Each panel may also contain test points and test wires, thereby allowing a continuity check of the fabricated panels and marking of faulty elements in the panel prior to final assembly and depanelization.

[0063] Referring to figure 8, there is illustrated an embodiment having multiple devices 100 stacked together. In such embodiments, an attachment member 502, such as a rod, may be used to hold the devices 100 together and/or to ensure that groups of mutually repulsive patterns focus the magnetic fields 109 into the PCB coils 1 12. The suspension membrane 108a may be drilled with a small pilot hole and magnets with hollow center cores can be stacked with alternating pole structures.

[0064] Referring to figure 9, there is illustrated an embodiment having a nonmagnetic material 902 provided inside the cavity 105, between the mass 106 and the housing 102. While a single non-magnetic material 902 is shown between the mass 106 and the top housing surface 104a, a second non-magnetic material may also be inserted between the mass and the bottom housing surface 104. Also alternatively, the non-magnetic material 902 may be provided only between the mass 106 and the bottom housing surface 104b. The non-magnetic material 902 extends the physical reach of the vibrations generated by the vertical movement of the mass 106 in the device 100 by raising the plane of vibration of the device 100 from the mass 106 to a surface 104a, 104b of the housing 102, without having to change the magnetic field configuration. This enhances the perceptual responses of the device 100 when the device 100 is affixed to a heavy object and the intent is direct skin stimulation rather than vibration generation, as the vibrations and motions from the mass 106 are conducted to the top and/or bottom housing surfaces 104a, 104b, and/or to the membranes, which are directly excited. In addition, energy expenditure may be reduced as the mass 106 has direct contact with the body part and thus needs less momentum to create the haptic sensation. Example materials for the non-magnetic material 902 are thermoplastic polymer, polyoxymethylene (POM) plastic, and other similar materials.

[0065] The above description is meant to be exemplary only, and one skilled in the relevant arts will recognize that changes may be made to the embodiments described without departing from the scope of the invention disclosed. Other variants are also possible. Note that the features illustrated with the flexible support as a membrane 108a are also applicable when the flexible support is embodied by slab(s), gel, or other variants described herein.

[0066] The structure illustrated is thus provided for efficiency of teaching the present embodiment. The present disclosure may be embodied in other specific forms without departing from the subject matter of the claims. Also, one skilled in the relevant arts will appreciate that while the devices disclosed and shown herein may comprise a specific number of elements/components, they may be modified to include additional or fewer of such elements/components. The present disclosure is also intended to cover and embrace all suitable changes in technology. Modifications which fall within the scope of the present invention will be apparent to those skilled in the art, in light of a review of this disclosure, and such modifications are intended to fall within the appended claims.