Patent Publication Number: US-7910851-B2

Title: Padstacks capable of receiving domes of dome keypads in a plurality of locations and printed circuit boards utilizing the padstacks

Description:
FIELD 
     Disclosed are padstack configurations and circuitry, and printed circuit boards utilizing the same that are capable of receiving the dome of a key of a dome keypad in a plurality of locations. 
     BACKGROUND 
     Manufacturers of electronic devices strive to limit and reduce the number of required customized parts utilized in the manufacture of their devices. The more commonality of parts between products that can be used in the manufacture of their devices the better the potential for cost savings which can be passed onto consumers. Bringing down the costs of manufacturing, particularly commodities such as mobile communication devices, benefits large segments of society. 
     Manufactures of electronic devices also strive to distinguish their products from others on the market. For example, different keypad designs may be used for different mobile communication device designs, even those produced by a single manufacturer. Different designs require different printed circuit board configurations to accommodate the placement of feature components. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention. 
         FIG. 1  illustrates an embodiment of printed circuit board depicted with dome locations place that would be placed high on a device; 
         FIG. 2  illustrates an embodiment of a printed circuit board which represents the same printed circuit board as printed circuit board of  FIG. 1  but depicted with dome locations place that would be placed low on a device; 
         FIG. 3  illustrates a first dome location for an embodiment of the dome switch pad that has elliptical padstack geometry; 
         FIG. 4  illustrates a second dome location for an embodiment of the dome switch pad that has elliptical padstack geometry; 
         FIG. 5  illustrates an embodiment of a padstack having a conjoined geometry; 
         FIG. 6  illustrates a circuitry embodiment for two padstacks, each having a conjoined geometry on a printed circuit board; 
         FIG. 7  illustrates an embodiment of a padstack having a keypad padstack complementary geometry; 
         FIG. 8  illustrates an embodiment of a padstack having a keypad dual padstack geometry; and 
         FIG. 9  illustrates an embodiment of a printed circuit board configured for a plurality of dome utilizing keypad configurations including a plurality of padstacks, at least some of which including a plurality of dome switch targets and a plurality of target rings. 
     
    
    
     DETAILED DESCRIPTION 
     A printed circuit board designed to receive a dome keypad includes a padstack for each key dome of the keypad. A padstack is the circuit arrangement for a single dome of a keypad. A padstack with a dome switch target and a target ring can receive a single keypad dome. A target ring is in contact with the circumference of a dome of a key of the keypad. A dome switch target can receive the center of a dome when it is depressed by a user utilizing the key of the keypad, to complete the circuit, and send a signal to the controller of the device that the key has been depressed. 
     It would be beneficial if a keypad printed circuit board design could accommodate a plurality of different keypad designs. The ability to use one printed circuit board design for multiple products, each having a different look in accordance with different keypad dome locations, could reduce cost in the manufacture of a plurality of electronic devices. For example, it would be beneficial if a keypad design with dome locations placed low on the device could utilize the same keypad printed circuit board design as a keypad design with dome locations placed high on the device. 
     Disclosed is a padstack of a printed circuit board configured for a dome-utilizing keypad configuration, including a dome pad having a plurality of available dome locations. The disclosed padstack has a plurality of dome switch targets and a single circuit configuration shared by the plurality of dome switch targets. In this way, a single padstack is capable of receiving different dome placements. Thus, different keypad designs may utilize the same printed circuit board. 
     Also disclosed is a printed circuit board configured for a dome-utilizing keypad configuration including an individual padstack having a plurality of dome switch targets and a plurality of target rings capable of accommodating different key dome locations of a dome keypad. The disclosed printed circuit board includes at least one padstack having a single dome switch targets input/output line for the plurality of dome switch targets of the padstack. The disclosed printed circuit board also includes a single target rings input/output line for the plurality of target rings of the padstack. In this way the disclosed printed circuit board includes a single circuit arrangement available for a plurality of different keypad designs. 
     The instant disclosure is provided to explain in an enabling fashion the best modes of making and using various embodiments in accordance with the present invention. The disclosure is further offered to enhance an understanding and appreciation for the invention principles and advantages thereof, rather than to limit in any manner the invention. While the preferred embodiments of the invention are illustrated and described here, it is clear that the invention is not so limited. Numerous modifications, changes, variations, substitutions, and equivalents will occur to those skilled in the art having the benefit of this disclosure without departing from the spirit and scope of the present invention as defined by the following claims. It is understood that the use of relational terms, if any, such as first and second, up and down, and the like are used solely to distinguish one from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. 
     At least some inventive functionality and inventive principles may be implemented with or in software programs or instructions and integrated circuits (ICs) such as application specific ICs. In the interest of brevity and minimization of any risk of obscuring the principles and concepts according to the present invention, discussion of such software and ICs, if any, is limited to the essentials with respect to the principles and concepts within the preferred embodiments. 
       FIG. 1  and  FIG. 2  depict a printed circuit board with dome keys of a keypad overlaid to illustrate that dome locations placed low on the device could utilize the same keypad design printed circuit board design as a keypad design with dome locations placed high on the device. 
       FIG. 1  illustrates a printed circuit board  102  depicted with dome locations that would be placed high on a device. Dome keys  104 -A,  104 -B,  104 -C,  104 -D,  104 -E,  104 -F,  104 -G,  104 -H,  104 -I,  104 -J,  104 -K and  104 -L assume a high position on a particular embodiment of the disclosed padstacks  106 -A,  106 -B,  106 -C,  106 -D,  106 -E,  106 -F,  106 -G,  106 -H,  106 -I,  106 -J,  106 -K and  106 -L, visible underneath the dome keys are the padstacks  104 -A,  104 -B,  104 -C,  104 -D,  104 -E,  104 -F,  104 -G,  104 -H,  104 -I,  104 -J,  104 -K and  104 -L. 
       FIG. 2  illustrates a printed circuit board  202  which represents the same printed circuit board as printed circuit board  102  (see  FIG. 1 ) depicted with dome locations that would be placed low on a device. Dome keys  208 -A,  208 -B,  208 -C,  208 -D,  208 -E,  208 -F,  208 -G,  208 -H,  208 -I,  208 -J,  208 -K and  208 -L assume a low position on a particular embodiment of the disclosed padstacks  206 -A,  206 -B,  206 -C,  206 -D,  206 -E,  206 -F,  206 -G,  206 -H,  206 -I,  206 -J,  206 -K and  206 -L, visible underneath the dome keys are the padstacks  208 -A,  208 -B,  208 -C,  208 -D,  208 -E,  208 -F,  208 -G,  208 -H,  208 -I,  208 -J,  208 -K and  208 -L. Accordingly, the printed circuit board  202  can accommodate a plurality of different keypad designs. As mentioned above, the ability to use one printed circuit board design for multiple products, each having a different look in accordance with different keypad dome locations, could beneficially reduce cost in the manufacture of a plurality of electronic devices. 
       FIG. 3  and  FIG. 4  illustrate different dome locations for an embodiment of the padstack  306  that has elliptical padstack geometry.  FIG. 3  and  FIG. 4  differ in the illustration of their respective dome locations. Like elements have been numbered accordingly. Embodiments of different geometries are disclosed below, in particular an embodiment of a complimentary padstack geometry, an embodiment of a conjoined padstack geometry, and embodiment of a dual padstack geometry. It is understood that other geometry configurations are within the scope of this discussion as are corresponding circuit configurations. Different dome sizes and arrangements may dictate which geometry is best. A larger dome provides a better tactile response. 
     As discussed above, the disclosed padstack  306  of a printed circuit board  202  (see  FIG. 2 ) includes a dome pad  310  having a plurality of available dome locations, the higher dome location  312  which is illustrated by  FIG. 3  and the lower dome location  414  (see  FIG. 4 ) which is illustrated by  FIG. 4 . The dome locations  312  and  414  are superimposed beneath the circuit elements such as dome switch targets (i.e.  316  and  318 ) for illustrative purposes. A dome would actually sit above the dome switch target. 
     The disclosed dome pad  310  has a plurality of dome switch targets  316  and  318  and a single circuit configuration  320  shared by the plurality of dome switch targets  316  and  318 . The dome switch target  316  is for dome location  312  and the dome switch target  318  is for dome location  314  of  FIG. 3 . The dome switch target  418  is for dome location  414  and the dome switch target  416  is for dome location  412  of  FIG. 4 . Referring to  FIG. 3 , the dome switch target  316  and  318  share a single circuit  320 . The dome locations, or target rings  312  and  314  share a single circuit  322 . Referring to  FIG. 4 , the dome switch target  416  and  418  share a single circuit  420 . The dome locations, or target rings  412  and  414  share a single circuit  422 . 
     Referring to  FIG. 3 , a target ring, either target ring  312  or  314  is in constant contact with at least a portion of the circumference of a dome of a key of the keypad. Either dome switch target  316  or  318 , depending upon the dome location, can receive the center of a dome when it is depressed by a user utilizing the key of the keypad, to complete the circuit and send a signal to the controller of the device that the key has been depressed. Thus, different keypad designs may utilize the same printed circuit board. 
       FIG. 5  illustrates an embodiment of a padstack having a conjoined geometry. The disclosed padstack having a conjoined geometry has a plurality of dome switch targets  530  and  532  and a plurality of target rings  534  and  536  capable of accommodating different key dome locations of a dome keypad. The disclosed padstack  506  includes a single dome switch targets input/output line  538  for the plurality of dome switch targets  530  and  532 . The disclosed padstack  506  also includes a single target rings input/output line  540  for the plurality of target rings  534  and  536 . In this way the disclosed printed circuit board  102  (see  FIG. 1 ) includes a single circuit arrangement available for a plurality of different keypad designs. 
       FIG. 6  illustrates a circuitry embodiment for two padstacks  606 -A and  606 -B, each having a conjoined geometry on a printed circuit board  602 . The circuitry involves a multiplexer  646 -A for padstack  606 -A coupled by lines  648  and  650 . Similar to the padstack  506  (see  FIG. 5 ), the disclosed padstacks  606 -A of  FIG. 6  having a conjoined geometry have a plurality of dome switch targets  630 -A and  632 -A and a plurality of target rings  634 -A and  636 -A capable of accommodating different key dome locations of a keypad design. The disclosed padstack  606 -A includes a single dome switch targets input/output line  638  for the plurality of dome switch targets  630 -A and  632 -A of the padstack  606 -A. The disclosed padstack  606 -A also includes a single target rings input/output line  640  for the plurality of target rings  634 -A and  636 -A of the individual padstack  602 -A. The single dome switch targets input/output line  638  and single target rings input/output line  640  are in communication with the host  642 . In this way the disclosed printed circuit board  602  includes a single circuit arrangement available for a plurality of different key pad designs. 
       FIG. 6  further illustrates the disclosed padstack  606 -B having a conjoined geometry have a plurality of dome switch targets  630 -B and  632 -B and a plurality of target rings  634 -B and  636 -B capable of accommodating different key dome locations of a keypad design. The circuitry involves a multiplexer  646 -B for padstack  606 -B coupled by lines  652  and  654 . The disclosed padstack  606 -B includes a single dome switch targets input/output line  644  for the plurality of dome switch targets  630 -B and  632 -B of the padstack  606 -B. The disclosed padstack  606 -B also includes a single target rings input/output line  646  for the plurality of target rings  634 -B and  636 -B of the individual padstack  602 -B. The single dome switch targets input/output line  644  and single target rings input/output line  646  are in communication with the host  642 . In this way the disclosed printed circuit board  602  includes a single circuit arrangement available for a plurality of different key pad designs. 
       FIG. 7  illustrates an embodiment of a padstack  702  having a keypad padstack complementary geometry having a plurality of available dome locations. The disclosed padstack  702  has a plurality of dome switch targets  760  and  762 . Moreover, the disclosed padstack  706  has a plurality of dome locations or ring targets  766  and  768 . When a dome location is the upper target ring  766  having circuitry  778 , the switch target  760  circuitry is  780 . When a dome location is the lower target  768  having circuitry  782 , the switch target  762  circuitry is  776 . In this embodiment, an input/output line for a first dome switch target is the input/output line for a target ring of a second dome switch target. That is, the single circuit configuration  764  is shared by the dome switch target  760  and ring target  768 . Moreover, the single circuit configuration  770  is shared by the dome switch target  762  and ring target  766 . The unconnected dummy regions  772  and  774  can be used to bridge a gap a dome circumference position. As with the other disclosed geometries, the disclosed padstack  706  includes a single circuit arrangement available for a plurality of different key pad designs. 
       FIG. 8  illustrates an embodiment of a padstack  806  having a dual padstack geometry having a plurality of available dome locations. The disclosed padstack  806  has a plurality of dome switch targets  884  and  886  and a single circuit configuration  888  shared by the plurality of dome switch targets  884  and  886 . Moreover, the disclosed padstack  806  has a plurality of target rings  890  and  892  and a single circuit configuration  894  shared by the plurality of target rings  890  and  892 . In this way, a single padstack is capable of receiving different dome placements. 
       FIG. 9  illustrates an embodiment of a printed circuit board  902  configured for a plurality of dome-utilizing keypad configurations including a plurality of padstacks, at least some of which including a plurality of dome switch targets and a plurality of target rings. An elliptical padstack geometry element  893  is depicted. Complementary padstack geometry elements  894 -A,  894 -B,  894 -C,  894 -D,  894 -E and  894 -F are depicted. Conjoined padstack geometry elements  895 -A and  895 -B are depicted. A dual padstack geometry element  896  is depicted. Padstack elements  897 -A and  897 -B having a single dome switch target and a single target ring are depicted. Accordingly, the printed circuit board is configured to cooperate with one of a plurality of different dome utilizing keypad configurations based on enabled particular electrical connections of the printed circuit board depending on utilized dome switch targets and utilized target rings. As mentioned, the printed circuit board may also include one or more padstacks having a single dome switch target and a single target ring. 
     The disclosed keypad printed circuit board design may accommodate a plurality of different keypad designs. The ability to use one printed circuit board design for multiple products, each having a different look in accordance with different keypad dome locations, could reduce cost in the manufacture of a plurality of electronic devices. Depending upon the arrangement of different types of padstack geometries, dome key locations of a plurality of different keypad designs may beneficially cooperate with a single printed circuit board. 
     This disclosure is intended to explain how to fashion and use various embodiments in accordance with the technology rather than to limit the true, intended, and fair scope and spirit thereof. The foregoing description is not intended to be exhaustive or to be limited to the precise forms disclosed. Modifications or variations are possible in light of the above teachings. The embodiment(s) was chosen and described to provide the best illustration of the principle of the described technology and its practical application, and to enable one of ordinary skill in the art to utilize the technology in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims, as may be amended during the pendency of this application for patent, and all equivalents thereof, when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled.