Patent Publication Number: US-2013233687-A1

Title: Multi-layer integral keypad

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation under 35 U.S.C. §120 of U.S. patent application Ser. No. 13/119,113, having a 35 U.S.C. §371(c) date of May 20, 2011, and entitled “Multi-Layer Integral Keypad”, which is incorporated by reference herein in its entirety. U.S. patent application Ser. No. 13/119,113 is a national stage filing (35 U.S.C. §371) of PCT/US2009/057145, filed on Sep. 16, 2009 which claims priority to and benefit from U.S. Provisional Patent Application Ser. No. 61/097,417, filed on Sep. 16, 2008. 
    
    
     TECHNICAL FIELD 
     This invention pertains to keypads, and more specifically to keypads having a plurality of keys coupled to one another as an integral unit. 
     BACKGROUND 
     A variety of keypads exist that are used for actuating corresponding switches of an electronic device. For example, computer keyboards often comprise a plurality of separate non-integral keycaps that are individually affixed to the computer keyboard. The keycaps may be individually actuated by a user, thereby causing the keycap to actuate a corresponding switch of the keyboard that is in electrical communication with an electrical circuit of the keyboard. 
    
    
     
       BRIEF DESCRIPTION OF THE ILLUSTRATIONS 
         FIG. 1  is a top perspective view of a first embodiment of a multi-layer integral keypad. 
         FIG. 2  is a side view of the multi-layer integral keypad of  FIG. 1  taken along the line  2 - 2 . 
         FIG. 3  is a bottom perspective view of the multi-layer integral keypad of 
         FIG. 1 . 
         FIG. 4  is a side view of the multi-layer integral keypad of  FIG. 1 . 
         FIG. 5  is a section view of a second embodiment of a multi-layer integral keypad. 
         FIG. 6  is top perspective view of a third embodiment of a multi-layer integral keypad. 
         FIG. 7  is a section through a portion of a mold in two different, successive steps in a first embodiment of a method for producing a multi-layer integral keypad. 
         FIG. 8  is a section through a portion of a mold in two different, successive steps in the first embodiment of a method for producing a multi-layer integral keypad. 
         FIG. 9  is a section through a portion of a mold in two different, successive steps in the first embodiment of a method for producing a multi-layer integral keypad. 
         FIG. 10  is a section through a portion of a mold in the first embodiment of a method for producing a multi-layer integral keypad. 
         FIG. 11  is a section through a portion of a mold in the first embodiment of a method for producing a multi-layer integral keypad. 
         FIG. 12  is a section through a portion of a mold in the first embodiment of a method for producing a multi-layer integral keypad. 
     
    
    
     SUMMARY 
     A multi-layer integral keypad is provided with a plurality of key tops each having a plastic layer coupled to a display layer. A resilient key top support layer integrally couples a plurality of the key tops to one another. A method for producing a multi-layer integral keypad is also provided. 
     DETAILED DESCRIPTION 
     It is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms “connected,” “coupled,” “in communication with” and “mounted,” and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. In addition, the terms “connected” and “coupled” and variations thereof are not restricted to physical or mechanical connections or couplings. Furthermore, and as described in subsequent paragraphs, the specific mechanical configurations illustrated in the drawings are intended to exemplify embodiments of the invention and that other alternative mechanical configurations are possible. 
     Referring now to  FIG. 1  through  FIG. 4 , a first embodiment of a multi- layer integral keypad  10  is shown. As used herein, “integral” means composed of a plurality of parts that are coupled to one another to make a whole. The depicted embodiment of the multi-layer integral keypad  10  has nine key tops  20  each supported by, and coupled to one another by, a key top support layer  40 . Each key top  20  has a metal display layer  21  having a display surface  22  and a back surface  24 . In some embodiments display layer  21  may be decorated aluminum. In other embodiments, display layer  21  may comprise other metal materials such as, for example, stainless steel, non-decorated aluminum, or a decorated composite metal. In other embodiments display layer  21  may comprise a thin non-metallic film such as, for example, a plastic film or ceramic film. Although in the depicted embodiment a flat and square display surface  22  and back surface  24  are shown, display surface  22  and/or back surface  24  may take on a number of contours, shapes, and textures. For example, in some embodiments display layer  21  may be generally annular and display surface  22  may be non-planar. Moreover, in alternative embodiments display layer  21  may be a different thickness and/or may be of a varying thickness. 
     Coupled to back surface  24  of display layer  21  and forming part of each key top  20  is a plastic layer  30 . In some embodiments of the invention the plastic layer may be poly(methyl methacrylate) (PMMA). In other embodiments, plastic layer  30  may comprise another plastic, such as, for example, nylon, polycarbonate, or acrylic fiber. In the depicted embodiment of  FIG. 1  through  FIG. 4  plastic layer  30  extends beyond the entire periphery of display layer  21 . In other embodiments plastic layer  30  may extend only beyond portions of the periphery of display layer  21  or may not extend beyond the periphery at all. In the first embodiment a top upward facing surface of plastic layer  30  is substantially planar with display layer  21 . In other embodiments the top upward facing surface of plastic layer  30  may be above or recessed below display layer  21 . 
     Symbols may also be provided on key tops  20 . In some embodiments one or more symbols  26  are provided through display layer  21  of key tops  20 . In some embodiments display surfaces  22  are additionally or alternatively printed with symbols. The depicted symbols  26  are circular apertures provided through display layer  21  of key tops  20  and are merely provided for exemplary purposes. With particular reference to  FIG. 2 , it is seen that plastic layer  30  may fill the apertures that create symbols  26 . In other embodiments symbol  26  may be unfilled or overfilled to provide tactile feel to a user. Ideally, each symbol  26  is distinct from any symbols on adjacent display surfaces  22  and conveys meaningful information to a user. Such symbols include, but are not limited to, numbers, letters, words, Braille, and graphical depictions. In some embodiments one or more symbols  26  that provide meaningful information to a user are provided as apertures through metal layers  21  and an aesthetically pleasing graphic is printed across one or more display surfaces  22  of metal layers  21 . There are various methods and apparatuses for forming apertures in a display layer  21  which may be used to form symbol  26 . Among these are the methods and apparatuses described in United States Patent Application Publication No. 2006/0019065, published on Jan. 26, 2006, and naming Taemmerich and Bruennel as inventors, which is hereby incorporated in its entirety by reference. The apparatus and method described in United States Patent Application Publication No. 2006/0019065 enables a web free symbol to be created in a metal layer of an ornamental part. 
     Plastic layer  30  may be transparent, translucent, or opaque. In embodiments where plastic layer  30  is transparent or translucent it will be appreciated that multi-layer integral keypad  10  may be installed over one or more light sources that are in optical communication with plastic layer  30  of one or more key tops  20  to illuminate one or more plastic layers  30 . For example, in some embodiments one or more electroluminescent panels, including, but not limited to, CeeLite&#39;s Light Emitting Capacitor, may be provided on a keyboard mounting surface or base and the multi-layer integral keypad  10  installed over the electroluminescent panels. Thus, those plastic layers  30  in optical communication with the electroluminescent panels will be illuminated and portions of those illuminated plastic layers  30  will be visible to a user. This includes, but is not limited to, the portions of plastic layer  30  that surround display layer  21  in some embodiments. This also includes, but is not limited to, any symbols  26  through which plastic layer  30  is visible. In other embodiments other light source may be used to illuminate plastic layer  30  of some or all of key tops  20  such as, for example, one or more light emitting diodes. 
     In some embodiments a actuating structure forms part of plastic layer  30 . Referring to  FIG. 2  and  FIG. 3 , actuating structure  32  is shown extending in a direction downward and away from back surface  24  of the metal layer of each key top  20 . The depicted actuating structure  32  is a substantially frusto-conical protrusion designed to interact with a corresponding come switch supported on an electronic keyboard mounting surface. Multi-layer integral keypad  10  is configured to interact with switches used with electronics, such as, for example, switches for keyboards, appliances, and other electronics. The switches and electronic devices multi-layer integral keypad  10  may be configured to interact with are numerous and actuating structure  32  may be adjusted to provide for interaction with any such switch and/or electronic device. For example, in some embodiments actuating structure  32  may be a recessed or flat surface instead of a protrusion. Also, for example, in some embodiments actuating structure  32  may be configured to interact with a dome-switch keyboard. In other embodiments actuating structure  32  may be configured to interact with a scissor-switch keyboard. Also, for example, in other embodiments actuating structure  32  may comprise a magnet and be configured to interact with a Hall Effect sensor switch. 
     With continuing reference to  FIGS. 1 through 4 , a key top support layer  40  is coupled to each key top  20  and integrally connects each key top  20  to one another. In the embodiment of  FIGS. 1 through 4 , key top support layer  40  has a rectangular key top support section  42  that is coupled to plastic layer  30  of key tops  20 . The key top support section  42  is connected to an arcuate and convex leg section  43  and the leg section  43  is connected to a key top base  45 . Key top support section  42  is coupled to each plastic layer  30  along a periphery thereof and surrounds actuating structure  32 . Key top support section  42  and leg section  43  collectively extend from key top  20  to base  45 , placing key top support  20  in a different plane than base  45 . Key top support layer is a resilient material that allows key top  20  to be in a stationary position when no force is applied to key top  20  by a user and to allow key top  20  to be in an activation position closer to base  45  when a predetermined force is applied to key top  20  by a user. Key top support  42  has an attachment area coupled to the base of plastic layer  30  and does not extend entirely under plastic layer  30 . When multi-layer integral keypad  10  is installed on an electronic device having a plurality of switches, actuating structure  32  does not contact a corresponding switch when key top  20  is in the stationary position. When a predetermined force is applied by a user and key top  20  moves closer to base  45 , actuating structure  32  contacts a corresponding switch on the electronic device. The design of key top support layer  40  allows each key top  20  to move from a stationary to an activation position without causing adjacent key tops  20  to also move to an activation position. 
     In the embodiment of  FIGS. 1 through 4 , base  45  connects key top supports  42  to one another and supports arcuate leg section  43  and key top support section  42 . 
     When multi-layer integral keypad  10  is installed on an electronic device having a plurality of switches, base  45  also provides a surface that can contact a corresponding mounting surface of the electronic device. Base  45  may also provide counterpressure to force supplied by a user on key top  20 . In some embodiments base  45  may be adhered to a corresponding mounting surface or may have protrusions, snaps, receptacles, or other securing devices that interact with a corresponding mounting surface to secure multi-layer integral keypad  10  to the mounting surface. Base  45  may also be provided with air passageway notches  47  that allow air to enter and exit therethrough when key top  20  moves between a stationary and activation position. Air passageways  47  minimizes vacuum when key tops  20  move between the stationary and activation positions. In other embodiments air passageways  47  may be omitted. In some embodiments air passageways may be provided through key tops  20 , key top supports  42 , or the electronic device with which multi-layer integral keypad is installed. 
     Key top support layer  40  may be comprised of any one of a variety of resilient materials of a durometer that is appropriate to enable a user to contact and depress a key top  20  and to provide tactile feedback to a user. Such materials include, but are not limited to, ethylene propylene diene Monomer rubber (EPDM), Thermoplastic elastomer (TPE), and ThermoPlastic Olefin (TPO). In some embodiments, such as those shown in the Figures, each key top support  42  and base  45  of key top support layer  40  are coupled to each key top  20  and to one another without any openings or gaps, so as to form a water and/or debris resistant multi-layer integral keypad  10 . When multi-layer integral keypad  10  is installed on an electronic device having a plurality of switches, water or debris that falls between key tops  20  will contact support layer  40  and will not immediately contact any internal electronics of the electronic device. It will be appreciated that the periphery of multi-layer integral keypad  10  may be appropriately installed and sealed with an electronic device so as to make the entire electronic device more water and/or debris resistant. 
     The configuration of key top support layer  40  and multi-layer integral keypad  10  may vary in many respects to accommodate varying electronic devices. For example, laptop keys have shorter travel distance for the keystroke than desktop keyboard keys. Thus, key top support layer  40  may be made “taller” or “shorter” and configured for either. Also, for example, actuating structure  32  may be adjusted dependent on keystroke distance. Likewise, for example, different amounts of spacing between key tops  20  may be required for different keyboards or other electronic devices. 
     Referring to  FIG. 5 , a section view of a second embodiment of a multi-layer integral keypad  100  is depicted. Multi-layer integral keypad  100  has metal layers  121  with a display surface  122  and a back surface  124 . Each metal layer  121  does not have any symbols provided therethrough. Plastic layer  130  is coupled to back surface  124  and extends beyond the periphery of the metal layer. Plastic layer  130  has a actuating structure  132  extending downward and away from back surface  124  of metal layer  121 . Plastic layer  130  has edges that are at right angles, unlike the upper beveled edges of plastic layer  30  visible in  FIG. 2 . Key top support layer  140  also varies from support layer  40  depicted in  FIG. 2 . A key top arcuate leg  143  has a concave, as opposed to convex, shape. Base  145  also varies in its configuration and is more rounded. Also, the distance between key top  120  and base  145  is less than in the first embodiment of  FIGS. 1 through 4 . 
     Referring to  FIG. 6 , a top perspective view of an additional embodiment of a multi-layer integral keypad  200  is depicted. Multi-layer integral keypad  200  is configured for use with a keyboard, such as, for example, a laptop keyboard. Multi-layer integral keypad  200  is formed without any openings or gaps, so as to be a water and/or debris resistant multi-layer integral keypad. 
     Referring now to  FIG. 7  through  FIG. 12 , an embodiment of a process for producing a multi-layer integral keypad is depicted. With regard to  FIGS. 7 through 9  it should generally be noted that each Figure consists of two half sections of a portion of a mold and the sequence in time of the operation of the mold has to be read in each case from left to right. Thus, the left half section in  FIG. 7  shows a first operating state which after a certain time passes over into the second operating state shown in the right half section of  FIG. 7 . The same applies to  FIG. 8  where the timing of the left half section directly follows the right half section of  FIG. 7  and the right half section of  FIG. 8  shows another sequence in the method which in turn, viewed in terms of time, passes over into the left half section of  FIG. 9 . This is then followed in time by the right half section of  FIG. 9 .  FIGS. 10 through 12  present further operating states of the mold, but are not presented in half sections. Thus the right half section of  FIG. 9  will be followed in time by  FIG. 10 ,  FIG. 10  will be followed in time by  FIG. 11 , and  FIG. 11  will be followed in time by  FIG. 12 . 
     It should also be noted that  FIGS. 7 through 10  depict interactions within a single mold cavity of a mold and  FIGS. 11 and 12  depict interactions within two adjacent mold cavities of a mold. One mold cavity and two mold cavities are shown for simplicities sake only. Any numbers of mold cavities may be provided neighboring one another and in a variety of configurations in a mold in order to form a multi-layer integral keypad. The methods taught by  FIGS. 7 through 12  may be adapted for use with any number and configuration of mold cavities and any configuration of multi-layer integral keypad. Also, the methods taught by  FIG. 7  through  FIG. 10  may be better understood with reference to United States Patent Publication Application No. 2006/0019065. 
     Referring now to the left half section of  FIG. 7 , a sheet of metal  1  is placed between an upper part of a mold  50  and a lower part of a mold  70 . Upper part of a mold  50  is provided with an upper forming punch  51  that is movable in a first direction indicated by arrow  2  and in a second direction opposite the direction indicated by arrow  2 . A die  52  is formed independently of upper forming punch  51  and can also move in a first direction indicated by arrow  2  and in a second direction opposite the direction indicated by arrow  2 . Lower part of a mold  70  is provided with a cushion  71  and a forming die  72  that form a mold cavity. Referring now to the right half section of  FIG. 7 , forming punch  51  and die  52  move in the direction of arrow  2  and abut sheet of metal  1 . 
     Referring now to the left half section of  FIG. 8 , forming punch  51  and die  52  move further in the direction of arrow  2  and cause a deformation in sheet of metal  1 . Cushion  71  is also displaced in the direction of arrow  2 . Referring now to the right half section of  FIG. 8 , forming punch  51  moves even further in the direction of arrow  2  and into the mold cavity formed by cushion  71  (shown further displaced in the direction of arrow  2 ) and forming die  72 . Sheet of metal  1  is cut into scrap piece  3  and metal layer  321  as a result of interaction between forming punch  51  and forming die  72 . 
     Referring now to the left half section of  FIG. 9 , stamping parts  77  and  78  are shown with corresponding ejector parts  57  and  58 . Referring now to the right half section of  FIG. 9 , stamping parts  77  and  78  are also shown on the right half section with corresponding ejector parts  57  and  58 , although in some embodiments any stamping parts provided on the right half side may vary from those provided on the left half side. Stamping parts  77  and  78  are moved in a direction opposite the direction of arrow  2  and cuts are made in metal layer  321 . Ejector parts  57  and  58  may provide counterpressure for this cut. Scrap pieces  7  and  8  from stamping parts  77  and  78  are shown with corresponding ejector parts  57  and  58  and may be removed when forming punch  51  is removed. 
     Referring now to  FIG. 10 , forming punch  51  is separated from metal layer  321 . A plastic layer  330  has been deposited into the gap formed between forming punch  51  and metal layer  321 . In some embodiments plastic layer  330  may be injected by a gate funnel (not shown) provided through forming punch  51 . The symbols formed by stamping parts  77  and  78  have been filled by plastic layer  330 . 
     Stamping parts may be used to create a variety of symbols through metal layer  321 , including web free symbols, and to cause metal layer  321  be a variety of shapes. For example, stamping parts, such as stamping parts  77  and  78  may be left within the apertures they create through metal layer  321 , while plastic layer  330  is deposited to aide in the creation of web free symbols. Also, for example, any apertures created may be unfilled, partially filled, or completely filled with plastic layer  330 . Also, for example, stamping parts may be used to cut out all or portions of the outer periphery of metal layer  321  if it is desired to have plastic layer  330  extend beyond the outer periphery of metal layer  321 . 
     Referring now to  FIG. 11 , one entire mold cavity is shown interposed between two forming dies  72  and half of a second mold cavity is shown to the right of the rightmost forming die  72 . Again, two mold cavities are shown only for simplicity and any number of mold cavities may be provided. Mold upper part  60  is moved into place over plastic layer  330 . Mold upper part  60  has a key top support mold  62  with a plurality of key top support gaps  64  provided therein. Referring now to  FIG. 12 , resilient material  340  may be injected into each key top support gap  64  and allowed to cure. In some embodiments resilient material  340  is injected by a gate funnel (not shown) provided through key top support mold  62 . In some embodiments resilient material is EPDM. The leftmost resilient material portion depicted in  FIG. 12  is representative of an edge of a multi-layer integral keypad and does not connect to anything to the left of leftmost forming die  72  (although the leftmost resilient material may be coupled to other metal layers  321  and plastic layers  330  that would be visually in front or behind of the section view shown). Once resilient material  340  has been allowed to cure, all metal layers  321  and plastic layers  330  will be coupled to one another to form an integral whole and multi-layer integral keypad produced. 
     The foregoing description has been presented for purposes of illustration. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. It is understood that while certain forms of the multi-layer integral keypad have been illustrated and described, it is not limited thereto except insofar as such limitations are included in the following claims and allowable functional equivalents thereof.