PATENT DOCUMENT

Publication Number: US-9619031-B1
Application Number: US-201514858710-A
Country: US
Kind Code: B1

Title: Haptic actuator including slidably coupled masses and related methods

Abstract:
A haptic actuator may include a housing having a top and a bottom, and first and second coils carried by the top and bottom, respectively, of the housing. The haptic actuator may also include a field member carried by the housing. The field member may include a permanent magnet between the first and second coils, first and second ends, and a first mass between the first end and the permanent magnet, and a second mass between the second end and the permanent magnet. A first shaft may slidably couple the first mass to the housing, and a second shaft may slidably couple the second mass to the housing. The haptic actuator may also include a first set of biasing members between the first end of the field member and the housing and a second set of biasing members between the second end of the field member and the housing.

Claims:
That which is claimed is: 
     
       1. A haptic actuator comprising:
 a housing having a top and a bottom; 
 first and second coils carried by the top and bottom, respectively, of the housing; 
 a field member carried by the housing and comprising
 at least one permanent magnet between the first and second coils, 
 first and second ends, and 
 a first mass between the first end and the at least one permanent magnet, and a second mass between the second end and the at least one permanent magnet; 
 
 a first shaft slidably coupling the first mass to the housing; 
 a second shaft slidably coupling the second mass to the housing; 
 a first set of biasing members between the first end of the field member and the housing; and 
 a second set of biasing members between the second end of the field member and the housing. 
 
     
     
       2. The haptic actuator of  claim 1  wherein the first and second coils comprise first and second loop shaped coils. 
     
     
       3. The haptic actuator of  claim 1  wherein the field member further comprises a third mass between the first and second masses and having a reduced width relative to the first and second masses. 
     
     
       4. The haptic actuator of  claim 3  wherein the at least one permanent magnet comprises a plurality of permanent magnets on each side of the third mass. 
     
     
       5. The haptic actuator of  claim 1  further comprising first and second mechanical bearings carried by the first and second masses and slidably receiving the first and second shafts. 
     
     
       6. The haptic actuator of  claim 1  wherein the housing comprises at least one sidewall between the top and bottom and comprising non-ferritic material. 
     
     
       7. The haptic actuator of  claim 1  wherein the top and bottom each comprises ferritic material. 
     
     
       8. The haptic actuator of  claim 1  further comprising a mechanical stiffener carried by one of the top and bottom of the housing. 
     
     
       9. The haptic actuator of  claim 1  wherein the first and second sets of biasing members comprise first and second sets of springs. 
     
     
       10. The haptic actuator of  claim 1  wherein the first and second ends of the field member comprise first and second sets of protrusions coupled to the first and second sets of biasing members, respectively. 
     
     
       11. The haptic actuator of  claim 1  wherein each of the first and second sets of biasing members has an equal number thereof between a respective one of the first and second ends and adjacent portions of the housing. 
     
     
       12. An electronic device comprising:
 a device housing; 
 wireless communications circuitry carried by the device housing; 
 a haptic actuator carried by the device housing and comprising
 an actuator housing having a top and a bottom; 
 first and second coils carried by the top and bottom, respectively, of the actuator housing, 
 a field member carried by the actuator housing and comprising
 at least one permanent magnet between the first and second coils, 
 first and second ends, and 
 a first mass between the first end and the at least one permanent magnet, and a second mass between the second end and the at least one permanent magnet, 
 
 a first shaft slidably coupling the first mass to the actuator housing, 
 a second shaft slidably coupling the second mass to the actuator housing, 
 a first set of biasing members between the first end of the field member and the actuator housing, and 
 a second set of biasing members between the second end of the field member and the actuator housing; and 
 
 a controller coupled to the wireless communications circuitry and the haptic actuator, and capable of performing at least one wireless communication function and selectively operating the haptic actuator. 
 
     
     
       13. The electronic device of  claim 12  wherein the first and second coils comprise first and second loop shaped coils. 
     
     
       14. The electronic device of  claim 12  wherein the field member further comprises a third mass between the first and second masses and having a reduced width relative to the first and second masses. 
     
     
       15. The electronic device of  claim 14  wherein the at least one permanent magnet comprises a plurality of permanent magnets on each side of the third mass. 
     
     
       16. The electronic device of  claim 12  further comprising first and second mechanical bearings carried by the first and second masses and slidably receiving the first and second shafts. 
     
     
       17. A method of making a haptic actuator comprising:
 positioning first and second coils to be carried by a top and a bottom, respectively, of a housing; 
 positioning a field member to be carried by the housing, the field member comprising at least one permanent magnet between the first and second coils, first and second ends, and a first mass between the first end and the at least one permanent magnet, and a second mass between the second end and the at least one permanent magnet; 
 slidably coupling the first mass to the housing using a first shaft; 
 slidably coupling the second mass to the housing using a second shaft; 
 positioning a first set of biasing members between the first end of the field member and the housing; and 
 positioning a second set of biasing members between the second end of the field member and the housing. 
 
     
     
       18. The method of  claim 17  wherein positioning the first and second coils comprises positioning first and second loop shaped coils. 
     
     
       19. The method of  claim 17  wherein positioning the field member comprises positioning the field member comprising a third mass between the first and second masses and having a reduced width relative to the first and second masses. 
     
     
       20. The method of  claim 19  wherein the at least one permanent magnet comprises a plurality of permanent magnets positioned on each side of the third mass. 
     
     
       21. The method of  claim 17  further comprising coupling first and second mechanical bearings to the first and second masses and to slidably receive the first and second shafts.

Description:
TECHNICAL FIELD 
     The present disclosure relates to the field of electronics, and, more particularly, to the field of haptics. 
     BACKGROUND 
     Haptic technology is becoming a more popular way of conveying information to a user. Haptic technology, which may simply be referred to as haptics, is a tactile feedback based technology that stimulates a user&#39;s sense of touch by imparting relative amounts of force to the user. 
     A haptic device or haptic actuator is an example of a device that provides the tactile feedback to the user. In particular, the haptic device or actuator may apply relative amounts of force to a user through actuation of a mass that is part of the haptic device. Through various forms of tactile feedback, for example, generated relatively long and short bursts of force or vibrations, information may be conveyed to the user. 
     SUMMARY 
     A haptic actuator may include a housing having a top and a bottom, and first and second coils carried by the top and bottom, respectively, of the housing. The haptic actuator may also include a field member carried by the housing. The field member may include at least one permanent magnet between the first and second coils, first and second ends, and a first mass between the first end and the at least one permanent magnet, and a second mass between the second end and the at least one permanent magnet. The haptic actuator may also include a first shaft may slidably couple the first mass to the housing, and a second shaft may slidably couple the second mass to the housing. The haptic actuator may also include a first set of biasing members between the first end of the field member and the housing and a second set of biasing members between the second end of the field member and the housing. Accordingly, the haptic actuator may provide increased force haptic feedback and occupy less space in an electronic device, for example, be relatively smaller in terms of height. 
     The first and second coils may be first and second loop shaped coils, for example. The field member may include a third mass between the first and second masses and having a reduced width relative to the first and second masses. The at least one permanent magnet may be a plurality of permanent magnets carried on each side of the third mass, for example. 
     The haptic actuator may also include first and second mechanical bearings carried by the first and second masses and slidably receiving the first and second shafts. The housing may include at least one sidewall between the top and bottom and that may include non-ferritic material, for example. The top and bottom may each include ferritic material. 
     The haptic actuator may also include a mechanical stiffener carried by one of the top and bottom of the housing. The first and second sets of biasing members may include first and second sets of springs, for example. 
     The first and second ends of the field member may include first and second sets of protrusions coupled to the first and second sets of biasing members, respectively. Each of the first and second sets of biasing members may each have an equal number thereof between a respective one of the first and second ends and adjacent portions of the housing, for example. 
     An electronic device aspect is directed to electronic device that may include a device housing and wireless communications circuitry carried by the device housing. The electronic device may also include a haptic actuator carried by the device housing and that may include an actuator housing having a top and a bottom, first and second coils carried by the top and bottom, respectively, of the actuator housing, and a field member carried by the actuator housing. The field member may include at least one permanent magnet between the first and second coils, first and second ends, and a first mass between the first end and the at least one permanent magnet, and a second mass between the second end and the at least one permanent magnet. The haptic actuator may also include a first shaft slidably coupling the first mass to the actuator housing, a second shaft slidably coupling the second mass to the actuator housing, a first set of biasing members between the first end of the field member and the actuator housing, and a second set of biasing members between the second end of the field member and the actuator housing. A controller may be to the wireless communications circuitry and the haptic actuator capable of performing at least one wireless communication function and selectively operating the haptic actuator. 
     A method aspect is directed to a method of making a haptic actuator. The method may include positioning first and second coils to be carried by a top and a bottom, respectively, of a housing and positioning a field member to be carried by the housing. The field member includes at least one permanent magnet between the first and second coils, first and second ends, and a first mass between the first end and the at least one permanent magnet, and a second mass between the second end and the at least one permanent magnet. The method may also include slidably coupling the first mass to the housing using a first shaft and slidably coupling the second mass to the housing using a second shaft. The method may further include positioning a first set of biasing members between the first end of the field member and the housing and positioning a second set of biasing members between the second end of the field member and the housing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an electronic device including a haptic actuator according to an embodiment of the present invention. 
         FIG. 2  is a schematic block diagram of the electronic device of  FIG. 1 . 
         FIG. 3  is a perspective view of a portion of the haptic actuator of  FIG. 1 . 
         FIG. 4  is an exploded perspective view of the haptic actuator of  FIG. 3 . 
         FIG. 5  is an electromagnetic simulation diagram of the haptic actuator of  FIG. 3 . 
         FIG. 6 a    is a perspective view of a portion of a haptic actuator according to another embodiment. 
         FIG. 6 b    is cross-sectional view of the portion of the haptic actuator of  FIG. 6 a    taken along line  6 - 1 . 
         FIG. 7 a    is a perspective view of a portion of a haptic actuator according to another embodiment. 
         FIG. 7 b    is cross-sectional view of the portion of the haptic actuator of  FIG. 7 a    taken along line  7 - 1 . 
     
    
    
     DETAILED DESCRIPTION 
     The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. Prime and multiple prime notations are used to refer to like elements in different embodiments. 
     Referring initially to  FIGS. 1 and 2 , an electronic device  20  illustratively includes a device housing  21  and a controller  22  carried by the device housing. The electronic device  20  is illustratively a mobile wireless communications device, for example, a wearable wireless communications device, and includes a band  28  or strap for securing it to a user. The electronic device  20  may be another type of electronic device, for example, a cellular telephone, a tablet computer, a laptop computer, etc. 
     Wireless communications circuitry  25  (e.g. cellular, WLAN Bluetooth, etc.) is also carried within the device housing  21  and coupled to the controller  22 . The wireless communications circuitry  25  cooperates with the controller  22  to perform at least one wireless communications function, for example, for voice and/or data. In some embodiments, the electronic device  20  may not include wireless communications circuitry  25 . 
     A display  23  is also carried by the device housing  21  and is coupled to the controller  22 . The display  23  may be a liquid crystal display (LCD), for example, or may be another type of display, as will be appreciated by those skilled in the art. 
     Finger-operated user input devices  24   a ,  24   b , illustratively in the form of a pushbutton switch and a rotary dial are also carried by the device housing  21  and is coupled to the controller  22 . The pushbutton switch  24   a  and the rotary dial  24   b  cooperate with the controller  22  to perform a device function in response to operation thereof. For example, a device function may include a powering on or off of the electronic device  20 , initiating communication via the wireless communications circuitry  25 , and/or performing a menu function. 
     The electronic device  20  illustratively includes a haptic actuator  40 . The haptic actuator  40  is coupled to the controller  22  and provides haptic feedback to the user in the form of relatively long and short vibrations or “taps”, particularly when the user is wearing the electronic device  20 . The vibrations may be indicative of a message received, and the duration of the vibration may be indicative of the type of message received. Of course, the vibrations may be indicative of or convey other types of information. More particularly, the controller  22  applies a voltage to move a moveable body or masses between first and second positions in a y-axis. 
     While a controller  22  is described, it should be understood that the controller  22  may include one or more of a processor and other circuitry to perform the functions described herein. For example, the controller  22  may include a class-D amplifier to drive the haptic actuator  40  and/or sensors for sensing voltage and current. 
     Referring now additionally to  FIGS. 3-4 , the haptic actuator  40  includes a housing  41  having a top  42  and a bottom  43 . The top  42  and bottom  43  of the housing  41  may be ferritic, for example, to increase efficiency. The housing  41  also includes a sidewall  46  that may include non-ferritic material to reduce effects on the magnetic field, as will be described in further detail below. The housing  41  has a rectangular shape. Exemplary dimensions may be 70 mm in length, 12 mm in width and 2.6 mm in height. Of course, the housing  41  can be another shape and have different dimensions. Moreover, while specific portions of the housing  41  are being described with respect to ferritic and non-ferritic materials, it should be understood that all or some of the housing may include ferritic material or be ferritic, or the housing may include a combination of ferritic and non-ferritic materials. 
     Respective mechanical stiffeners  47 ,  48  may be carried by the top  42  and bottom  43  of the housing  41 . Each mechanical stiffener  47 ,  48  may be non-ferritic, and more particularly, non-ferritic steel. Any number of mechanical stiffeners may be used, including none, and may be carried by any portion of the housing  41 . The mechanical stiffeners  47 ,  48  may be another type of material. 
     The haptic actuator  40  also includes first and second coils  44 ,  45  (i.e., electrical coils) carried by the top and bottom  42 ,  43 , respectively, of the housing  41 . The first and second coils  44 ,  45  each illustratively have a loop shape or “racetrack” shape and are aligned in a stacked relation and spaced apart. 
     The haptic actuator  40  may also include a field member  50  carried by the housing. The field member  50  illustratively includes permanent magnets  51 ,  52  between the first and second coils  44 ,  45  and is movable within the housing  41 . While the movement of the field member  50  may be described as being moveable in one direction, i.e., a linear haptic actuator, it should be understood that in some embodiments, the field member may be movable in other directions, i.e., an angular haptic actuator, or may be a combination of both a linear and an angular haptic actuator. 
     The permanent magnets  51 ,  52  may be neodymium, for example, and may be positioned with in opposing directions with respect to their respective poles. The permanent magnets  51 ,  52  also have a rectangular shape and are aligned along a length of the first and second coils  44 ,  45 . While a pair of rectangular shaped permanent magnets is illustrated, it will be appreciated that there may be any number of permanent magnets having any shape between the first and second coils  44 ,  45 . 
     The field member  50  also includes first and second ends  53 ,  54 . The first and second ends  53 ,  54  have first and second sets of protrusions  55 ,  56  for coupling to first and second sets of biasing members  71 ,  72 , respectively, as will be described in further detail below. The first and second sets of protrusions  55 ,  56  are illustratively in the form of circular protrusions and extend outwardly in opposing directions. An equal number of protrusions may extend in each direction. 
     The field member  50  includes a first mass  57  is between the first end  53  and the permanent magnets  51 ,  52 . A second mass  58  is between the second end  54  and the pair of permanent magnets  51 ,  52 . A third mass  59  extends between the first and second masses  57 ,  58 . The third mass  59  has a reduced width relative to the first and second masses  57 ,  58 . This permits the permanent magnets  51 ,  52  to be on each side of the third mass  59 . In some embodiments, a third mass  59  may not be included and/or the third mass may have a different shape, for example. Each of the first, second, and third masses  57 ,  58 ,  59  may be tungsten, for example. The first, second, and third masses base may each be a different material. 
     The first, second, and third masses  57 ,  58 ,  59  which collectively may be referred to as the “moving part,” are spaced from the first and second coils  44 ,  45  by a relatively small gap. In other words, the first and second coils  44 ,  45  do not touch the first, second, and third masses  57 ,  58 ,  59 . 
     The haptic actuator  40  also includes a first shaft  61  slidably coupling the first mass  57  to the housing  41 . A second shaft  62  slidably couples the second mass  58  to the housing  41 . The first and second shafts  61 ,  62  may be a nickel-chromium alloy, for example. The first and second shafts  61 ,  62  may be generally parallel to each other, and as will be appreciated by those skilled in the art, may limit motion to a desired translational movement that may be parallel to y-axis (width). The first and second shafts  61 ,  62  may also limit movement in other directions, for example, lateral movement, rotation, and/or wobbling with respect to prior art haptic actuators. The first and second shafts  61 ,  62  may be particularly advantageous lower frequency operation, for example, 110-200 Hz and, more specifically, 70-200 Hz. 
     First and second mechanical bearings  63 ,  64  are carried by the first and second masses  57 ,  58  and slidably receive the first and second shafts. The first and second mechanical bearings  63 ,  64  may be slot bearings. 
     It will be appreciated by those skilled in the art that the first and second shafts  61 ,  62  may be sliding with respect to a combination of circular and slot bearings  63 ,  64  so that unwanted directions of force may be constrained while reducing the chances of jamming due to over-constraint. The first and second mechanical bearings may be mounted such that they are mounted on the moving mass  57 ,  58 ,  59  (and hence the shafts  61 ,  62  are fixed to the housing  41 ) or mounted on the housing (and hence the shafts are fixed to the moving mass). 
     The haptic actuator  50  also includes a first set of biasing members  71  between the first end  53  of the field member  50  and the housing  41  and a second set of biasing members  72  between the second end  54  of the field member and the housing. The first and second sets of biasing members  71 ,  72  may be spring, for example, and more particularly, coil and/or leaf springs and may be steel. The first and second sets of biasing members  71 ,  72  may be other types of biasing members and may be another material. As noted above, the first, second, and third masses are spaced from the first and second coils  44 ,  45 . The first and second sets of biasing members  71 ,  72  assist in maintaining this spacing, and increase stiffness. While twelve (12) total biasing members are shown in the form of coil springs (i.e., mechanical coils), it should be understood that any number and type of biasing members may be used. Each of the first and second sets of biasing members  71 ,  72  may each have an equal number thereof between a respective one of the first and second ends  44 ,  45  and adjacent portions of the housing, for example. 
     The haptic actuator  40  described herein may provide relatively more momentum in a smaller package or housing. A smaller size of the housing, particularly with respect to height or z-axis direction, may become increasingly desirable as electronic devices become smaller, yet it may be desirable to maintain or increase the strength of the haptic feedback (i.e., momentum than 2000 g/mm/sec). 
     Referring now to current map  80  in  FIG. 5 , an electromagnetic simulation for the haptic actuator  40  is illustrated. The arrows indicate current flow direction and at the arrow surface, relative current density. Illustratively, the haptic actuator  40 , based upon the relative current density and the relative magnetic flux density, has a relatively high efficiency. 
     Referring briefly to  FIGS. 6 a  and 6 b   , in another embodiment, there may be more than one first and second coils. Illustratively, the haptic actuator  40 ′ may include two first coils  44   a ′- 44   b ′ and two second coils  45   a ′- 45   b ′ to be carried by a top  42 ′ and a bottom  43 ′, respectively, of a housing  41 ′ instead of a single first and second coil as described above. Each of the first and second coils  44   a ′- 44   b ′,  45   a ′- 45   b ′ have a loop shape. Of course there may be any number of first and second coils and the number of first and second coils may not be the same. First, second, and third permanent magnets  51 ′,  52 ′,  81 ′ are between the first and second coils  44   a ′- 44   b ′,  45   a ′- 45   b ′. The third mass may be in the form of two masses  59   a ′,  59   b ′ between the first and second masses  57 ′,  58 ′ and each having a reduced width relative to the first and second masses. More particularly, the two third masses  59   a ′,  59   b ′ may be laterally between the first and the third permanent magnets  51 ′,  81 ′, and the second and third permanent magnets  52 ′,  81 ′, respectively. 
     A method aspect is directed to a method of making a haptic actuator. The method includes positioning first and second coils  44 ,  45  to be carried by a top  42  and a bottom  43 , respectively, of a housing  41 . The method also includes positioning a field member  50  to be carried by the housing  41 . The field member  50  includes at least one permanent magnet  51 ,  52  between the first and second coils  44 ,  45 , first and second ends  53 ,  54 , a first mass  57  between the first end and the at least one permanent magnet, and a second mass  58  between the second end and the at least one permanent magnet. The method also includes slidably coupling the first mass  57  to the housing  41  using a first shaft  61 , slidably coupling the second mass  58  to the housing using a second shaft  62 , and positioning a first set of biasing members  71  between the first end of the field member  50  and the housing  41 . The method further includes positioning a second set of biasing members  72  between the second end  54  of the field member  50  and the housing  41 . 
     Referring now to  FIGS. 7 a  and 7 b   , in another embodiment, the haptic actuator  40 ″ may include first, second, and third permanent magnets  51 ″,  52 ″,  81 ″ carried by the actuator housing  41 ″, and the field member  50 ″ may include first and second coils  44   a ″,  44   b ″ that cooperate with the permanent magnets. In other words, in contrast to the embodiment described above with respect to  FIGS. 6 a  and 6 b   , the permanent magnets  51 ″,  52 ″,  81 ″ are stationary (i.e., carried by the actuator housing  41 ″) and the coils  44   a ″  44   b ″, as part of the field member  50 ″ are moving (i.e., connected to the mass). The third mass may be in the form of three masses  59   a ″,  59   b ″,  59   c ″ between the first and second masses  57 ″,  58 ″ and each having a reduced width relative to the first and second masses. Of course, there may be any number of coils, permanent magnets, and/or masses. 
     While a specific arrangement of the haptic actuator  40  has been described, it will be appreciated that in other embodiments, other configurations within the scope of the claims may be contemplated, for example, with respect to the positioning of the shafts  61 ,  62 , bearings  63 ,  64 , and biasing members  71 ,  72  (e.g., springs). Additionally, it will be appreciated that elements described in one or more of the embodiments may be used in any of the other embodiments. Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within the scope of the appended claims.

Metadata:
Filing Date: 20150918
Publication Date: 20170411
Grant Date: 20170411
Priority Date: 20150918
Inventors: HAJATI ARMAN
HARLEY JONAH A.
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F3/016", "inventive": true, "first": true, "tree": "[]"}, {"code": "H02K33/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "G08B6/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02K33/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "G08B6/00", "inventive": true, "first": true, "tree": "[]"}, {"code": "H02K33/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": true, "tree": "[]"}, {"code": "G08B6/00", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 58282581