PATENT DOCUMENT

Publication Number: US-8212162-B2
Application Number: US-72414310-A
Country: US
Kind Code: B2

Title: Keys with double-diving-board spring mechanisms

Abstract:
Keys may be formed for keyboards. The keyboards may be attached to electronic devices such as computers or may be formed within a portable computer or other electronic equipment. A keyboard may be provided with a planar housing member such as a top plate. The top plate may have openings through which key caps protrude. Each key cap may be attached to a respective spring mechanism. The spring mechanism for each key may have first and second diving-board structures that flex about respective parallel flex axes. A dome switch may be mounted under each spring mechanism. The dome switch is compressed when the key cap is pressed and the first diving-board structure moves towards the dome switch. The top plate may have edge portions surrounding each key opening that form upstop structures that prevent the key caps and spring mechanisms from tilting when the dome switch is compressed.

Claims:
1. A key comprising:
 a double-diving-board spring mechanism formed from a sheet of material; and 
 a key cap mounted on the double-diving-board spring mechanism, wherein the double-diving board spring mechanism comprises first and second diving board structures each having a tip and wherein the tips of the first and second diving board structures are pointed in different directions. 
 
     
     
       2. The key defined in  claim 1  further comprising:
 a top plate structure having an opening in through which the key cap protrudes. 
 
     
     
       3. The key defined in  claim 2  wherein the top plate comprises metal. 
     
     
       4. The key defined in  claim 3  wherein the metal comprises an aluminum sheet with a thickness of between 0.05 and 3 mm. 
     
     
       5. The key defined in  claim 4  wherein the double-diving-board spring mechanism comprises a sheet of metal. 
     
     
       6. The key defined in  claim 5  wherein the double-diving-board spring mechanism comprises at least two U-shaped grooves in the sheet of metal. 
     
     
       7. The key defined in  claim 6  wherein the sheet of metal comprises a sheet of stainless steel with a thickness of between 0.1 mm and 0.3 mm. 
     
     
       8. The key defined in  claim 1  wherein the double-diving-board spring mechanism comprises a sheet of metal. 
     
     
       9. The key defined in  claim 1  wherein the double-diving-board spring mechanism comprises a sheet of metal having grooves that define first and second diving board structures that flex about respective first and second parallel flex axes. 
     
     
       10. The key defined in  claim 9  wherein the grooves comprise at least two U-shaped grooves. 
     
     
       11. The key defined in  claim 10  further comprising adhesive that attaches the key cap to the first diving board structure. 
     
     
       12. The key defined in  claim 11  further comprising a dome switch mounted under the spring mechanism. 
     
     
       13. The key defined in  claim 1  further comprising a dome switch that is actuated using at least part of the spring mechanism. 
     
     
       14. The key defined in  claim 13  wherein the sheet of material comprises a sheet of metal with a thickness of between 0.1 mm and 0.3 mm thick having grooves that define shapes for first and second diving board structures in the spring mechanism. 
     
     
       15. The key defined in  claim 1  further comprising a top plate having an upstop portion that surrounds the key cap and prevents the key cap from tilting by stopping movement of at least part of the spring mechanism. 
     
     
       16. A keyboard, comprising:
 a housing structure having a plurality of key openings; and 
 a plurality of keys each of which protrudes through a respective one of the key openings, wherein each of the keys includes a respective one of a plurality of double-diving-board spring mechanisms, wherein, when a respective one of the keys is not being depressed by a user, the double-diving board spring mechanism of that key is approximately parallel to the housing structure. 
 
     
     
       17. The keyboard defined in  claim 16  wherein each key comprises a key cap member attached to a respective one of the double-diving-board spring mechanisms, wherein each double-diving-board spring mechanism comprises a sheet of metal having grooves that define first and second diving board structures, and wherein, for each of the keys, when a respective one of the keys is not being depressed by a user, the first and second diving board structures associated with that key are approximately parallel to the sheet of metal. 
     
     
       18. The keyboard defined in  claim 17  further comprising a plurality of dome switches each of which is associated with a respective one of the keys, wherein the housing structure comprises upstop portions that prevent tilting of the double-diving-board spring mechanisms when the dome switches are depressed. 
     
     
       19. A key, comprising:
 a housing structure having an opening; 
 a key cap member that protrudes through the opening; and 
 a sheet of metal having U-shaped grooves that define first and second spring structures in the sheet of metal that flex about respective parallel flex axes, wherein the first spring structure is nested within the second spring structure, wherein the key cap member is attached to the first spring structure, wherein the first and second spring structures each have a tip, and wherein the tips of the first and second spring structures are pointed in different directions. 
 
     
     
       20. The key defined in  claim 19  further comprising a dome switch that is compressed by the first spring structure when the key cap member is depressed, wherein the housing structure comprises upstop structures that prevent pivoting of the key cap member when the key cap member is depressed and the dome switch is compressed. 
     
     
       21. The key defined in  claim 19  wherein the tips of the first and second spring structures are pointed in opposite directions. 
     
     
       22. The key defined in  claim 1  wherein the tips of the first and second diving board structures are pointed in opposite directions. 
     
     
       23. The key defined in  claim 1  wherein the double-diving-board spring mechanism comprises a sheet of metal having grooves that define the first and second diving board structures, wherein the first and second diving board structures each have an equilibrium position, and wherein, when the first and second diving board structures are in their equilibrium positions, the first and second diving board structures are approximately coplanar with the sheet of metal.

Description:
BACKGROUND 
     This relates to electronic devices and, more particularly, to keys for electronic devices such as keyboards and equipment that includes keyboards. 
     Electronic devices such as computer keyboards and portable computers have keys. Keys generally include a plastic key cap attached to a switch mechanism. The key caps may be labeled with alphanumeric characters. When a key is pressed, the switch mechanism closes. The closed state of the switch mechanism may be detected by circuitry in the keyboard. 
     Keys are sometimes provided with springs. For example, some keyboards use a bucking spring design in which a coil spring biases each key cap. Scissor-type springs may also be used in keyboards to help provide key caps with spring action. Keyboards such as these tend to exhibit large amounts of travel. This may not be desirable, particularly in keyboard applications that require low profile designs and quiet operation. 
     In keyboards with relatively low amounts of key travel, key caps are sometimes attached directly to dome switches. Keyboards of this type may sometimes exhibit rattle due to insufficient control of the lateral displacement of the keycaps or may provide undesirably low amounts of tactile feedback due to the modest amount of spring action provided by the dome switches. 
     It would therefore be desirable to be able to provide improved keys and keyboards for use in electronic equipment such as computers and computer accessories. 
     SUMMARY 
     Keys may be provided for keyboards. The keyboards may be connected to external equipment or may be formed as an integral portion of a portable computer or other device. 
     Each keyboard may have a housing. The housing may have a planar upper surface such as a metal top plate that has key openings. Keys in the keyboard may be provided with key caps. Each key cap may be provided with a label. The key caps may protrude through the key openings in the metal top plate. 
     A double-diving-board spring mechanism may be mounted under each key cap. A dome switch may be mounted below each spring mechanism. When a user pressed downwards on a key cap, the double-diving-board spring mechanism pressed downwards on a corresponding dome switch. 
     Each spring mechanism may have first and second diving-board structures that flex about respective parallel flex axes. The top plate may have edge portions surrounding each key opening that form upstop structures. The upstop structures for each key may prevent the key cap and spring mechanism for that key from tilting when the dome switch for that key is compressed. 
     Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative portable computer that may be provided with a keyboard and keys in accordance with an embodiment of the present invention. 
         FIG. 2  is a perspective view of an illustrative keyboard that may be provided with keys in accordance with an embodiment of the present invention. 
         FIG. 3  is an exploded perspective view of a key for a keyboard in accordance with an embodiment of the present invention. 
         FIG. 4  is a cross-sectional side view of a key in a keyboard in accordance with an embodiment of the present invention. 
         FIG. 5  is a bottom view of an illustrative key in a keyboard in accordance with an embodiment of the present invention. 
         FIG. 6  is a perspective view of an illustrative key in a keyboard in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     This relates to keys for electronic equipment. The equipment in which the keys are provided may be a keypad, a stand-alone keyboard such as a stand-alone computer keyboard, a keyboard that is built into an electronic device such as a portable computer, or other suitable electronic devices. 
     An illustrative computer that may be provided with a keyboard is shown in  FIG. 1 . As shown in  FIG. 1 , portable computer  10  may have a housing  12 . Housing  12 , which is sometimes referred to as a case, may be formed from one or more individual structures. For example, housing  12  may have a main structural support member that is formed from a solid block of machined aluminum or other suitable metal. One or more additional structures may be connected to the housing  12 . These structures may include, for example, internal frame members, external coverings such as sheets of metal, etc. Housing  12  and its associated components may, in general, be formed from any suitable materials such as plastic, ceramics, metal, glass, composites, etc. 
     Case  12  may have an upper portion  26  and a lower portion  28 . Lower portion  28  may be referred to as the base or main unit of computer  10  and may contain components such as a hard disk drive, battery, and main logic board. Upper portion  26 , which is sometimes referred to as a cover or lid, may rotate relative to lower portion  28  about rotational axis  16 . Portion  18  of computer  10  may contain a hinge and associated clutch structures and is sometimes referred to as a clutch barrel. 
     Lower housing portion  28  may have a slot such as slot  22  through which optical disks may be loaded into an optical disk drive. Lower housing portion may also have a touchpad such as touchpad  24  and may have keys  40 . Keys  40  may protrude from planar housing surface  42 . Keys  40  may include letter keys, number keys, keys labeled with symbols, or other suitable keys. Keys  40  may be individual keys or as part of a keyboard such as keyboard  20  (e.g., a QWERTY keyboard). If desired, keys  40  may be formed as part of a keypad (e.g., keyboard that contains primarily or exclusively number keys and mathematical function keys). 
     Additional components may be mounted to upper and lower housing portions  26  and  28 . For example, upper and lower housing portions  26  and  28  may have ports to which cables can be connected (e.g., universal serial bus ports, an Ethernet port, a Firewire port, audio jacks, card slots, etc.). Buttons and other controls may also be mounted to housing  12 . 
     Openings may be formed in the surface of upper and lower housing portions to allow sound to pass through the walls of housing  12 . For example, openings may be formed for microphone and speaker ports. With one illustrative arrangement, speaker openings such as speaker openings  30  may be formed in lower housing portion  28  by creating an array of small openings in the surface of housing  12 . 
     A display such as display  14  may be mounted within upper housing portion  26 . Display  14  may be, for example, a liquid crystal display (LCD), organic light emitting diode (OLED) display, or plasma display (as examples). A glass panel may be mounted in front of display  14 . The glass panel may help add structural integrity to computer  10 . For example, the glass panel may make upper housing portion  26  more rigid and may protect display  14  from damage due to contact with keys or other structures. 
     An illustrative stand-alone keyboard that may contain keys  40  is shown in  FIG. 2 . As shown in  FIG. 2 , keyboard  32  may have a housing such as housing  38 . A cable  36  and connector  34  may be connected to housing  38 . If desired, keyboard  32  may include batteries and wireless communications circuitry. 
     Housing  38  may be formed from metal, plastic, carbon-fiber composites and other composites, glass, ceramics, other materials, and combinations of these materials. Housing  38  may be formed from one or more structural pieces such as planar upper surface member  42 . As with planar surface member  42  of computer  10  in  FIG. 1 , keys  40  may protrude through openings in planar surface  42 . Planar housing surfaces such as surface  42  of  FIG. 2  and surface  42  of  FIG. 1  are sometimes referred to as top plates, top plate structures, and plate members. The openings that are formed in planar housing structures such as top plates  42  of  FIGS. 1 and 2  may be square, rectangular, circular, oval, etc. In a typical arrangement, the openings in top plates  42  are square and rectangular and accommodate corresponding square and rectangular keys  40 . 
       FIG. 3  shows an exploded perspective view of an illustrative key. As shown in  FIG. 3 , key  40  may include key cap  44  (sometimes referred to as a key member or button structure). A label such as an alphanumeric character or symbol may be formed on the upper surface of key cap. Label  60  may, for example, be formed by printing ink or paint on the surface of key cap  44 , by machining or molding a desired shape into key cap  44 , by etching a desired pattern into key cap  44 , by laser etching a desired pattern into key cap  44 , by laser etching a desired pattern into key cap before or after printing ink or paint on the surface of key cap  44 , by attaching a sticker to the surface of key cap  44 , etc. Key cap  44  may be formed from plastic, metal, glass, ceramic, composites, other materials, or combinations of these materials. For example, key cap  44  may be formed from a plastic button-shaped member. 
     Top plate  42  may be provided with an opening such as opening  62 . Opening  62  preferably has inner dimensions that are sufficiently large to accommodate the outer periphery of key cap  44 . With one suitable arrangement, there may be about a 0.1 mm to 0.3 mm clearance between each of the outer edges of key cap  44  and each of the corresponding edges of opening  62 . The edges of opening  62  may be have vertical sidewalls or may have a notched shape. When provided with a notched shape, portions of key cap  44  may, if desired, overlap the edges (e.g., by covering the lower horizontal surfaces of the notches). 
     Top plate  42  may be formed from plastic, metal, glass, ceramic, composites, other materials, or combinations of these materials. For example, top plate  42  may be formed from a layer of metal such as aluminum. The aluminum or other metal that makes up top plate  42  may be anodized or provided with other coatings. The thickness of top plate  42  may be between 0.3 and 0.5 mm, between 0.2 and 0.6 mm, between 0.05 and 1 mm, between 0.05 and 3 mm, or may be any other suitable thickness. The top plate may, for example, form part of a unitary housing for computer housing  12  of  FIG. 1  or may form part of a unitary housing for housing  38  of  FIG. 2 . The top plate may also be formed as a separate structure that is attached to other housing structures (e.g., to form a cover or other planar top surface for a keyboard). 
     Key  40  may include a spring mechanism such as spring mechanism  64 . Key cap  44  may be attached to spring mechanism  64  using adhesive  78  or other suitable attachment mechanisms (e.g., screws or other fasteners, springs, clips, mating engagement features, etc.). Because spring mechanism holds key cap  44  securely within the opening  62 , the outer edges of key cap  44  will generally not strike the inner edges of opening  62 . This prevents the keys from rattling. 
     When key cap  44  is pressed downwards in direction  75  by the finger of a user or other object, central portion  70  of spring mechanism  64  may press downwards in direction  75  against dome switch  66  (e.g., on top of nub  68  of switch  66 ). Dome switch  66  may be formed from a flexible dome member such as an elastomeric or metal dome member. The underside of the dome member may be coated with metal, so that depression of the dome switch causes the metal to short two corresponding traces (e.g., traces on a printed circuit board to which dome switch  66  is mounted). Nub member  68  may be formed from epoxy or other suitable materials and serves as an actuation point against which spring mechanism  64  may bear when depressed. 
     Spring mechanism  64  may be formed from a sheet of metal, plastic, or other suitable material such a planar sheet member  80 . With one suitable arrangement, sheet member  80  is formed from a layer of stainless steel that is about 0.2 mm thick, between 0.1 mm and 0.3 mm thick, between 0.05 mm and 0.3 mm thick, or between 0.05 mm and 0.7 mm thick (as examples). Thinner spring mechanism sheets tend to make spring mechanism  64  more flexible. Thicker sheets tend to make spring mechanism  64  stiffer. 
     Spring mechanism  64  has a double-diving-board design. Outer U-shaped groove  48  surrounds first substantially rectangular diving board structure  74 . Inner U-shaped groove  50 , which faces in the opposite direction from outer U-shaped groove  48 , is nested within outer U-shaped groove  50  and surrounds second substantially rectangular diving board structure  70 . 
     U-shaped groove  48  includes side grooves  48 A and  48 B that are connected by tip groove  48 C. U-shaped groove  50  includes side grooves  50 A and  50 B that are connected by tip groove  50 C. Adhesive  78  may be formed on diving-board structure  70 . 
     The double diving board layout of spring mechanism  64  forms a spring that provides key cap  44  with a restoring upwards force when key cap  44  is depressed. When pressed, key cap  44  moves downwards in direction  75  and the diving-board shapes in switch mechanism  64  flex about axis  52  and  56 . In particular, hinge portions  84  allow tip portion  72  of member  70  to flex downwards in direction  75 , so that inner diving board structure  70  pivots in the opposite direction (i.e., direction  58 ) around flex axis  56 . At the same time, hinge portions  82  of switch mechanism  64  allow tip portion  76  of outer diving board structure  74  to flex downwards in direction  75 , so that outer diving board structure  74  pivots in direction  54  about flex axis  52 . When key cap  44  moves sufficiently in direction  75 , the dome membrane in dome switch  66  is compressed and the dome switch closes to indicate that key  40  has been actuated. 
     Because the diving board structures of switch mechanism  64  are oriented so that their tips point in opposite directions, key cap  44  does not tilt excessively when depressed near the center of key cap  44 . Tip  76  of diving board structure  74  is aligned with flex axis  56  of diving board structure  70 , whereas tip  72  of diving board structure  70  is aligned with flex axis  52  of diving board structure  74 . As a result, the potential tilt that is induced when one diving board structure bends about its flex axis offsets the potential tilt when the other diving board structure bends about its flex axis. Because the tilts from the diving boards offset one another, key cap  44  exhibits little or no tilt as key  40  is actuated (e.g., as a user presses down on key cap  44  near the center of key cap  44 ). When a user presses down on key cap  44  near an edge of key cap  44 , key cap  44  may exhibit limited tilt in the direction the user presses. 
     A cross-sectional side view of an illustrative key cap resulting from taking a cross-section through key  40  of  FIG. 3  along a cross-sectional line that is parallel to axis  56  and axis  54  is shown in  FIG. 4 . As shown in  FIG. 4 , key cap  44  rests on inner diving board member  70 . In the example of  FIG. 4 , key cap  44  has portions  116  that bear against diving board member  70 . Portions  116  may restrain the movement of key cap  44  along the horizontal axis of  FIG. 4  and along the axis into and out of the plane of  FIG. 4 . 
     Key cap  44  may have an optional hollow inner cavity (cavity  88 ). When key cap  44  includes optional cavity  88 , adhesive  78  may be located under peripheral portions of key cap  44 . 
     In the example of  FIG. 4 , sheet member  80  is mounted to top plate  42 . Screws  118  may be screwed into bores  120  in top plate  42  or other suitable attachment mechanisms such as adhesive may be used in securing sheet member  80  and spring mechanism  64  (e.g., diving board members  70  and  74 ) relative to top plate  42 . In general, any desired number of screws  118  (or other attachment mechanisms) may be used in securing sheet  40  to top plate  42 . Screws  118  and other attachment mechanisms used in securing sheet  40  to top plate  42  may be located in any desired locations. 
     Dome switch  66  may be mounted to printed circuit board  90 . Printed circuit board  90  may be formed from a rigid printed circuit board substrate such as fiberglass-filled epoxy, a flexible printed circuit board substrate such as a layer of polymer (e.g., polyimide), or any other suitable substrate (e.g., plastic). Conductive traces on printed circuit board  90  may form terminals for dome switch  66 . When dome switch  66  is compressed, these terminals may short to one another, thereby closing switch  66 . Connectors such as connectors  98  and  102  and flex circuit cable  100  (or other suitable interconnect structures) may be used to connect printed circuit board  90  to main logic board  104 . Main logic board  104  may include integrated circuits for processing key switch signals from keys  40 . In the example of  FIG. 4 , main logic board  104  is mounted to keyboard housing structure  106  (e.g., a lower planar member that is part of housing  38  of  FIG. 2  or that is part of housing  12  of computer  10  of  FIG. 1 ). Screw  94  may be screwed into threaded bore  96  in housing boss  92  or other suitable attachment mechanisms may be used in securing boards  90  and  104  relative to top plate  42 . 
     When key cap  44  is pressed downwards, the center of key cap  44  bears against central nub  68  on dome switch  66 . In this type of situation, nub  68  may tend to serve as a central pivot point for key cap  44 . If, for example, a user presses key cap  44  downwards at one of its four corners or at another off-center location, the portion of key cap  44  that is located on the opposing side of nub  68  will tend to be pivoted upwards. If not properly controlled, this tendency for key cap  44  to pivot may cause key cap  44  to tilt by an undesirable amount during use. 
     Top plate  42  and spring mechanism  64  (e.g., diving board member  74 ) may overlap to prevent tilting of key cap  44 . In particular, top plate  42  may have upstop portions  108  that prevent key  40  from tilting undesirably when key  40  and diving board member  70  presses downwards on nub  68  of dome switch  66 . If desired, upstop portions  108  may be formed from protrusions on plate  42 . When upstop portions  108  are formed from protrusions, the upstop portions may be formed as integral portions of top plate  42  or may be formed from a layer of material that is mounted to the lower surface of top plate  42  (as examples). 
     During key actuation events, upstop portions  108  (e.g., the lower surfaces of portions  108 ) engage the corresponding portions of sheet  80  of spring mechanism  64  (e.g., the upper surfaces of portions of diving board structures  70  and  74 ) to prevent one edge of key cap  44  from moving upwards as an opposing edge of key cap  44  pivots downwards during key depression. 
       FIG. 5  shows a bottom view of key  40  and  FIG. 6  shows a perspective bottom view of key  40 .  FIGS. 5 and 6  illustrate how upstop portions  108  may overlap tip portion  72  of inner diving board structure  70  and the edges and tip portion  76  of outer diving board structure  74 . Dashed line  114  ( FIG. 5 ) shows where the cross-section of  FIG. 4  was taken. Dashed line  111  ( FIG. 5 ) follows the inner perimeter of upstop portions  108  of top plate  42  (i.e., the innermost edges of opening  62  of  FIG. 3 ). As shown in  FIGS. 5 and 6 , additional groove structures such as groove opening  110  may be formed in sheet  80  to help provide the diving-board hinges formed from sheet  80  with a desired amount of flexibility. 
     Diving board structure  70  and key cap  44  may, if desired, be provided with mating features that help align key cap  44  on spring mechanism  64 . For example, diving board structure  70  or other portions of sheet  80  in spring mechanism  64  may be provided with protrusions  112  that mate with corresponding recesses in the bottom of key cap  44 . 
     The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20100315
Publication Date: 20120703
Grant Date: 20120703
Priority Date: 20100315
Inventors: ZHOU MI
Assignee: APPLE INC
CPC Classifications: [{"code": "H01H13/7073", "inventive": true, "first": true, "tree": "[]"}, {"code": "F16F3/023", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/7057", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H2221/058", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2221/036", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 44558905