Abstract:
The present invention is a keyboard in which the aspect ratio of the keyboard, front to back relative to the side to side dimension is significantly less than that of current keyboards which is achieved by staggering the heights of the rows of keys from front to back to give a users fingers additional clearance. Other methods of enhancing typability on small and miniature keyboards is also disclosed.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This application claims priority to U.S. Provisional Patent Application 60/302,895, filed on Jul. 2, 2001. 
     
    
     
       BACKGROUND  
         [0002]    The present invention generally relates to keyboards or keypads for electronic devices, and more particularly to compact keyboards or keypads for electronic devices.  
           [0003]    Keyboards and keypads are the most popular means for the entry of data into electronic devices pointer-enabled data entry (e.g. a mouse a drop-down menu or a virtual keyboard), two other popular means of data entry, keyboards and keypads remain the most commonly used data entry devices for most electronic devices, including desktop computers, laptop computers, handheld computers, electronic books (ebooks), cell phones, calculators, personal information managers (PIMs) and personal digital assistants (PDAs). Even some of the popular handheld computers and PDAs that were originally designed for keyboardless data entry, have recently been offered in models which incorporate a miniature keyboard. In a related development, manufacturers of accessories for these devices have begun to sell keyboard peripherals (i.e. separate keyboards which can be attached to an electronic device) for portable electronic devices.  
           [0004]    Keyboards are currently designed under a single paradigm (keyboard and keypad are used interchangeably herein). Under this paradigm, keys are supposed to be operated by pressing a finger down full upon their centers. Thus all keyboards share as a design feature key design and arrangement on the keyboard to facilitate actuation by downward force on the center of the key with a finger tip. This design feature of keyboards is shared by full-size desktop computer keyboards, by miniature keyboards for handheld computers and PDAs, by calculator and pocket organizer keyboards, by appliance keypads, by phone and telephone keypads, and even by collapsible and folding keyboards Keys on keyboards and keypads are spaced to prevent multi-key actuation, and keyboards and keypads of the prior art are designed so that the distance from the center of one key to the closest part of any adjacent is approximately equal. This constrains these keyboards to an aspect ratio of between three-quarter (3:4) and one (1:1). The aspect ratio of a keyboard is the ratio of the distance from between the closest edges of keys in a first row and a second row that are separated by a third row to the distance between the closest edges of a first key and a second key in the same lateral row that are separated by a third equal sized key (a standard sized key such as a letter key). Thus on a standard keyboard for a desktop computer the aspect ratio is one (three-quarters of an inch by three-quarters of an inch which corresponds to the size of an average adult finger tip), on the keyboard of the portrait view Blackberry  5810  and the landscape view Blackberry RIM  950  pagers it is about 6:5, on the Handspring Treo 270 PDA cell phone it is about 7:8, on the Palm, Inc. Palm Mini Keyboard it is about 1:1, on the new Sony Clie NR70V it is 4:3, on the Sharp Zaurus SL-5500 it is about 6:5, and on the Sharp Wizard YO180 about 5:6. Since the fingertip has a slightly low aspect ratio of about 5:6 to 7:8, it is worse to have a high-aspect ratio than a 1:1 aspect ratio.  
           [0005]    An aspect ratio of approximately 1:1 makes sense if a user is intended to actuate the keys by pressing on their center with a finger because it equalizes the clearance between the target key and adjacent keys in all directions. If one reduces the aspect ratio of present keyboards, one must be more and more careful to avoid striking multiple keys.  
           [0006]    However, it severely constrains the range of possible keyboard sizes and shapes.  
           [0007]    The underlying rule governing the design of prior art keyboards that the aspect ratio of the keyboard must be about 1:1 has prevented keyboard designers from designing keyboards with aspect ratios much less than 1:1. It is, however, sometimes desirable to have keyboards with an aspect ratio significantly lower than one. For example, an aspect ratio of one means that a keyboard that is three inches wide (such on the Blackberry  8510 , the Handspring Treo and the Palm Mini Keyboard) will be roughly one inch deep (front to back). On a typically sized PDA or handheld computer, one inch is roughly one-quarter of the usable surface area, the rest is occupied by the display and the handwriting data entry touch pad. Although users might prefer a larger screen, the size of the display cannot be increased without either eliminating the keyboard, the handwriting data entry touch pad (as is done on the Handspring Treo combination PDA-cell phone) or shrinking the depth of the keyboard. Moreover, some cell phones with integrated PDA functionality have screens viewed in landscape orientation with the cell phone held sideways. There is no room for a keyboard of current design because there is only about one-half inch of space between the screen and the edge of the case. Given current design, a keyboard ½″ in depth would be 1.5 inches in width, far to small for use There are those who would prefer their handheld computers to have a landscape orientation, but again, a conventional, 1:1 aspect ratio keyboard could not be added to handheld computers with a standard-size display in landscape orientation without increasing the width dimension of the devices beyond the three inches that fits in a standard shirt pocket. And electronic devices continue to shrink in size.  
           [0008]    Some devices, such as tablet computers and ebooks are primarily portable display screens, and keyboards for these devices must be particularly compact and unobtrusive. A very shallow or low-aspect ratio keyboard along the bottom edge of the device might be a valuable addition, but current keyboard design makes this impossible to implement. Devices such as a pen computer cannot accommodate a keyboard with an aspect ratio of one; they can only accommodate a very shallow keyboard. Other electronic devices such the computer mouse or game input devices (e.g. a joystick) for games that call for text entry could incorporate a low aspect ratio keyboard, but would have difficulty accommodating a standard design keyboard with an aspect ratio of one. MP3 players would be improved by the addition of a keypad or keyboard for data entry and conducting searches, but conventional 1:1 aspect ratio keyboards are too big. Keyboards for Internet kiosks are a problem because they stick out so far from the structure in which the kiosks are typically embedded; a low aspect ratio keyboard would work better. For the new car computer entertainment systems, a standard design keyboard will either be unobtrusive, but too small to be easily used, or big enough to use relatively easily, but large and obtrusive. Again, a low aspect ratio keyboard would be preferred.  
           [0009]    Furthermore, small and miniature keyboards not only have an aspect ratio of approximately 1:1 which limits their variety, but the are also flat. Because they are flat it is harder to distinguish between keys and it is easier to hit more than one. Almost as detrimental to usability, on flat miniature keyboards a user&#39;s finger obscures quite a few keys from view when typing, which makes it difficult for a user to see where and what he or she is pressing. Because the user presses the keys in their center, the ability to see keys in all directions from the target key are obstructed (on a BlackBerry keyboard, an adult thumb obstructs the view of all or part of seven to ten keys, including the target key the user intends to actuate). To mitigate the problem of hitting multiple keys at a time, some electronic devices use algorithms to guess which of the several keys pressed by the user is the key the user meant, but this is at the price of complexity, power consumption and CPU bandwidth. Unfortunately, those algorithms do not solve the problem of the finger obscuring multiple keys, nor do they always guess the correct key.  
         DISCLOSURE OF THE INVENTION  
         [0010]    It is the object of the present invention to overcome the drawbacks of constraining keyboards to (1) layouts with an aspect ratio of approximately 1:1 and (2) layouts in the two dimensions of width (side to side along the rows) and depth (back of the keyboard to the front). It is the object of the present invention both to make small and miniature keyboards with a 1:1 aspect ratio more usable and to create new low-aspect ratio keyboards for multiple applications and devices. FIGS. 1A and 1B demonstrate the advantage of a keyboard in which rows are at different heights. FIG. 1A is a side view of a flat, miniature prior art keypad with three rows of keys. The user is using his finger  13  to actuate the key in the middle row  11 , but because the key depth  18  is so small, the user&#39;s finger  13  overlaps and may actuate the keys  10  &amp;  12  in the adjacent rows. FIG. 1B is a keypad of the present invention with rows of different heights. The user is using his finger  13  to actuate the key in the middle row  15 . Because there is a sufficient height differential  19  between the key in middle row  15  and the key in the first row  16 , there is clearance  17  between the finger  13  and the key in the first row  16  and the user only actuates the intended key. The height differential  19  also allows the user to press the edge of the key in the middle row  15  rather than its center which keeps his finger  13  from actuating a key in the last row  14  to the back. This simple set of drawings clearly illustrate why, for any size keyboard, but especially for small and miniature keyboards, a height differential between rows enhances the keyboard&#39;s usability, and why the keyboards of the present invention which incorporate such a height differential between rows are superior to conventional, prior art keyboards.  
           [0011]    Note that in the following text and drawings, the QWERTY alphanumeric keyboard (which, unless otherwise indicated, will be what is meant hereinafter by the word keyboard) is often used as the example, but everything that is said about QWERTY keyboards applies to any keyboard or keypad with at least two rows of keys containing at least two keys in each row. The following also refers frequently to electronic devices such as handheld computers, PDAs, pagers, cell phones and laptops, but it also applies to any electronic device with, or that could have, a keypad for entry, such as a calculator, entertainment device (e.g. radio and MP3 player) and even a kitchen appliance into which data can be entered.  
           [0012]    It is an object of the present invention to improve the type-ability of small and miniature 1:1 aspect ratio keyboards by introducing a vertical height differential between rows of keys that increases the physical separation of keys in different rows and by altering the cross-sectional shape of the keys so that the perceived and effective physical separation of keys in the same row is likewise increased. Type-ability of small and miniature keyboards of the present invention is improved because in operation the user&#39;s finger obstructs fewer keys than are obstructed on a prior art keyboard of the same size, and because it is easier to avoid inadvertent actuation of multiple keys.  
           [0013]    It is another object of the present invention to introduce keyboards with an aspect ratio of significantly less than 1:1 for inclusion in a variety of electronic devices. These include extremely low-aspect ratio keyboards (1:3, 1:4 or even lower) for devices such as: peripheral keyboards that are easier to carry and store because they are narrow, but are wide enough for easy typing; keyboards that can be incorporated into the edge of ebooks and tablet computers so that display screen area is not lost; keyboards for radios, TVs, set-top boxes, remote control devices and other electronics for entertainment; smaller keypads for cell phones, especially for those without a handset; keyboards for incorporation in cell phones and handheld computers below a landscape-oriented display screens; keyboards for pen-type computers; keyboards for computer kiosks that stick out from the kiosk one-half, one-third or even one-quarter as much as a standard aspect ratio keyboard yet have full width, easy to utilize keys; keyboards for future portable computers which have flexible display screens that fold or roll up so that these future computers are not constrained in size to that of the keyboard; and many other varieties of keyboards for a multitude of electronic devices.  
           [0014]    The keyboards and keypads of the present invention can be incorporated directly into an electronic device or be designed for use as a peripheral for an electronic device. The present invention can be a keypad of any type and key layout, including, but not limited to alphanumeric keyboards, number pads, calculator keypads, and telephone dial pads. Any reference herein to a keypad or keyboard can apply to any keypad consisting of more than one row of keys, each row consisting of at least two keys. The keyboard of the present invention can be of any width, from full-size to miniature. The keys can be set into a sloping housing, mounted in a series of steps in the housing, or the keys can just be progressively taller to create ever higher rows. Keys can have vertical front edges that butt up against or are adjacent to the back edge of the keys in the row below, or the keys can overhang keys in row below. The keys can be square, triangular, oblong, diamond or any shape that is appropriate.  
           [0015]    It is another object of the present invention to enable the creation of keyboards with more rows than a standard desktop computer keyboard. By reducing the aspect ratio of the keyboard, a keyboard can have more rows of keys without an increase in the size of its footprint. A reduction of the aspect ratio by a factor of 2 would allow a doubling of the number of rows within the 4.75 inch deep footprint of a full-size keyboard from six to twelve rows. Such a keyboard would be extremely useful for non-alphabet languages such as Japanese and Chinese and for languages with many more than 26 letters. These multilevel keyboards with extra rows could also be useful for scientists using frequent symbols, musicians, graphic artists and any other application that frequently uses more characters than those on a standard  101 -key keyboard.  
           [0016]    It is another object of the present invention to provide for keyboards built into a sloping side of an electronic device, such as in the end of a handheld computers or a PDA. The 0.7 inch depth of many of these portable devices provides sufficient room for a keyboard of the present invention.  
           [0017]    It is another object of the present invention to provide keyboards that can be operated in either single level (i.e. like existing keyboards) and multilevel modes. Keys of such a keyboard are constructed such that they have a point or edge oriented upwards when in flat single-level mode and to have a flat surface oriented upwards when in multilevel mode. The switch for single-level mode to multilevel mode can be accomplished either by tilting the keyboard separately or by tilting the entire device of which the keyboard is a part.  
           [0018]    It is a further object of the present invention to provide a small or miniature keyboard that allows easy typing with both a finger and a stylus.  
           [0019]    It is a further object of the present invention to provide a new key design for keyboards with a height differential between the rows.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]    [0020]FIG. 1A is a drawing of a finger typing on a flat miniature prior art keypad.  
         [0021]    [0021]FIG. 1B is a drawing of a finger typing on a miniature keypad of the present invention.  
         [0022]    [0022]FIG. 2A is a side view of a keyboard of the present invention wherein the height differential is created by a stepped substructure.  
         [0023]    [0023]FIG. 2B is a perspective view of the keyboard of FIG. 2A.  
         [0024]    [0024]FIG. 3A is a side view of keyboard of the present invention with cantilevered key tops and pivoting key actuation.  
         [0025]    [0025]FIG. 3B is an exploded perspective view of the keyboard of FIG. 3A.  
         [0026]    [0026]FIG. 4A is a side view of a keyboard of the present invention with pivoting keys that is appropriately used in both an inclined orientation and in a flat orientation. The keypad is shown in the inclined orientation.  
         [0027]    [0027]FIG. 4B shows the keypad of FIG. 4A in the flat orientation.  
         [0028]    [0028]FIG. 4C is an exploded perspective view of the keypad of FIG. 4A.  
         [0029]    [0029]FIG. 4D is the keypad of FIG. 4A built into a keypad assembly along the side of a portable electronic device in the stored position vertically against the side.  
         [0030]    [0030]FIG. 4E shows the keypad of FIG. 4D in the open inclined position for use.  
         [0031]    [0031]FIG. 5A shows several options for key shapes for a keyboard with the cantilevered key tops shown in FIG. 4A.  
         [0032]    [0032]FIG. 5B is a view from under a keypad which incorporates the cantilevered keys shown in FIG. 4A with a key top in one of the optional shapes shown in FIG. 5A.  
         [0033]    [0033]FIG. 6 is a top view of a miniature QWERTY keyboard with cantilevered key tops of the type shown in FIG. 4A and the shape shown in FIG. 5A as compared in size to a prior art keyboard of the same width.  
         [0034]    [0034]FIG. 7 is a side view of a keyboard of the present invention wherein the key tops of the keys in each row are progressively thicker in vertical dimension.  
         [0035]    [0035]FIG. 8A is a side view of a keyboard of the present invention in which the keys in one row are nested between the keys of the adjacent rows.  
         [0036]    [0036]FIG. 8B is a top view of the nested keyboard shown in FIG. 8A.  
         [0037]    [0037]FIG. 8C is a perspective drawing of a portion of the nested keyboard of FIG. 8A showing how the nesting of the keys combined with the vertical height differential between rows makes it easier to type on a miniature of this type using a stylus.  
         [0038]    [0038]FIG. 9A is a top view of a low-aspect ratio peripheral keyboard of the present invention for use with a handheld computer.  
         [0039]    [0039]FIG. 9B is a stylized side view of the peripheral keyboard of FIG. 9A showing the orientation of the keys relative to the connector.  
         [0040]    [0040]FIG. 10A is a top view a keyboard of the present invention that is built into the side of a combination cell phone/PDA.  
         [0041]    [0041]FIG. 10B is a stylized side view of the keyboard of FIG. 10A. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0042]    More particularly, the keyboards and keypads of the present invention comprise and set of at least four keys arranged in at least two rows of unequal height, the higher row(s) being further from the user when in use. The top surfaces of the keys are at an angle to the slope of the keyboard (from highest to lowest row). The keys are operated by pressing on the front edge of the key (the portion nearest the user). The vertical height differential between keys in one row and those in a lower adjacent row is sufficient to provide enough clearance that a finger pressing down on the front edge of a key in one row will not accidentally actuate a key in the lower row. The minimum height differential between rows should be between one-eighth to one-quarter inch to ensure that all but unusually large fingers have adequate clearance. Keys in one row can be directly in line with keys in adjacent rows, or they can be offset from each other.  
         [0043]    The invention relates to a keyboard or keypad assembly. Specific details of an embodiment of the keyboard assembly are described below. Numerous specific details including keyboard layouts, specific structural arrangements and relationships, etc. are presented in order to provide a thorough understanding of the invention. It is to be appreciated that these specific details need not be specifically employed to practice the invention and that there are other details that are not presented so as not to unnecessarily obscure the description of the invention that may be substituted or included that fall within the scope of the claimed invention.  
         [0044]    [0044]FIGS. 2A &amp; 2B are different views of the keypad  40 . FIG. 2A is a perspective view of a preferred embodiment of the keypad of the invention. The keypad  40  of FIG. 2A comprises a key support  42  of stepped construction having arranged upon it sixteen key assemblies  41 . The keypad  40 , and all other keypads and keyboards of the present invention, has a first lateral axis  30  (from side to side), a second longitudinal axis  31  (from the front of the keyboard to the back), and a third vertical axis the leading edge  44  of a first key  105  in a first row  107  to the trailing edge  36  of a second key  106  in a second lower row  108  that is separated from the first row  107  by a single intervening row  109  to the lateral distance  111  from the right edge of a first key  112  disposed to the left of a second key  113  to the left edge of a third key  114  situated to the right of the second key  113 . The aspect ratio of the keypad  40  is one-half but it could be less or more. The key support  42  has a first side  39  (not visible) and a second side  101 . The second side  101  of key support  42  is formed into four laterally parallel steps  46  of equal longitudinal dimension  53  and vertical rise  102 , and having a vertical front face  37 , and a horizontal top surface  103 . Affixed at equal intervals laterally along the top surface  103  of each step  46  are four key assemblies  41  consisting of a key top  43  and a key actuator assembly  58 . Key assemblies  41  in one row are offset from those in adjacent rows by half the distance from the centers of two keys in the same row. Pressing down on the key top  43  of a key assembly  41  actuates the key actuator assembly  58  and generates an electronic signal. Key tops  43  have a leading edge  44  and a trailing edge  36 , and a longitudinal dimension  50  and a lateral dimension  51 . The key actuator assemblies  58  are connected to a wiring layout (not shown, but which will be obvious to those skilled in the art as it sill differ only superficially from existing wiring layouts) which can either be situated on first side  39  of support  42  or on the second, stepped side  101  of key support  42 .  
         [0045]    The embodiment of the invention in FIG. 2A is not a particular type of keyboard or keypad, but rather preferred way to construct a multi-level keypad of the present invention having a vertical height differential  56  between the lateral horizontal plane of the keys in one row and that of an adjacent row. It is intended to be built into a housing with other components necessary to create a standalone keypad or into the housing of an electronic device. The basic components of the keypad in FIG. 6 can modified to create keypads and keyboards of any type, including alphanumeric keyboards, telephone keypads, calculator keyboards, and many more.  
         [0046]    This embodiment is advantageous because the keypad  40  is of FIG. 2A &amp; 2B is easy to produce, consisting of readily available components already used in existing keypads and keyboards (since in operation the key assemblies  58  still have a vertical axis. The keypad  40  differs from current keyboards by (1) addition of a shelf to change orientation of the plane of each row of keys from approximately tangential to the board supporting the keys to inclined relative to the board supporting the keys, (2) by the angle of keyboard support relative to the plane of the keys, and (3) by its low-aspect ratio. In operation, the keypad  40  of FIG. 2A &amp; 2B would preferably be at an angle such that in use the plane of the tops of the keys in each row is roughly horizontal, although some users may prefer a different angle of use. An advantage of the design of the keypad  40  in FIG. 2A is that because the key assemblies  41  have the same vertical axis that a prior art keyboard does, it can be assembled using the key mechanisms of any prior art keypad with the same footprint and layout (because the steps  46  have a vertical face  37 , the combined area of the top surfaces  103  of the steps  46  is that of a prior art keyboard with the same lateral and longitudinal dimensions as the keypad  40 ), provided, however, that the key tops are sufficiently stable that force applied to their front edge will actuate the key and that the shape of the key tops provides a relatively distinct leading or front edge.  
         [0047]    [0047]FIG. 2B is a side view of the keypad of FIG. 2A. The plane of the top surface  103  of the steps  46  is at an angle theta  47  to the plane of the bottom side of key support  42  and creates a vertical height differential  56  between the top surfaces  115  of two adjacent rows of keys. The leading edges  44  of the key mechanisms  41  are aligned with the rising face  37  of the steps  46 . The vertical difference  56  between the heights of adjacent rows must be enough that there is a positive clearance  45  between the user&#39;s finger  48  and the adjacent key in a lower row  120 . The key mechanism  41  can be any key mechanisms used in a touch-typable desktop or laptop keyboards provided that key top  43  is sufficiently stable that force applied to the leading edge  44  of the key top  43  will actuate the key mechanism  41  and not substantially deform or tilt the key top  43 . The longitudinal dimension of the steps  46  is no larger than the longitudinal dimension of the key top  43 . Note that finger  48  deforms somewhat on contact with key top  43 . The key front edge  44  in the keypad of FIGS. 6 and 7 is a right-angle, but key front edge  44  can also be sloped or concave or any other shape that does not overly reduce or eliminate all together clearance  45 . Preferable key front edge form will enhance the keypad user comfort or keypad usability without significantly effecting finger clearance  45  while in use.  
         [0048]    [0048]FIG. 3A shows a partial side view of another embodiment of the invention. In this keypad  130 , the leading edge  131  of the key top  127  of a key assembly  129  in a first row  122  of keys extends substantially beyond the trailing edge  121  of the key top  127  and of the key assembly  129  in a second, vertically lower row  123  of keys. Unlike the embodiment shown in FIGS. 2A &amp; 2B, in the keypad  130  shown in FIG. 3A &amp; 3B the key support  124  is substantially flat on both sides (i.e. no steps). The key top  127  is shaped to perform the same function that the steps  46  performed in the keypad  40  of FIG. 2A &amp; 2B; it creates an angle between the plane of the keys and the plane of the key support  124 . The key top  127  is cantilevered over key actuator  133 . The key top  127  has a first thin rectangular planar element  126  and a second thin and shorter rectangular planar element  128  that are longitudinally parallel and that are joined at a substantial elbow  132  at a vertical angle  142  to each other (the angle  142  is the same as the angle of the key support  124  to the horizontal plane). Projecting laterally from each side of the elbow  132  at the intersection of planar elements  126  &amp;  128  are two pegs  135  which are engaged within a C-shaped bracket  134  on each side of the key assembly  129  which is molded into or attached fixedly to the key support  124  and which creates a pivot point around which the key top  127  can rotate on an axis parallel to the lateral axis of the keypad  130 . The first planar element  128  projects through a slot  151  in the optional keypad cover  136  and extends parallel to the longitudinal axis of the keypad  130  and the top surface  141  of the key top  127  is horizontal. The leading edge  144  of the shorter of the two planar elements  128  is pivotably attached by a lateral pin  137  to the leading edge  145  of the key actuator assembly  133  creating a pivot point around which the key top  127  can rotate on an axis parallel to the lateral axis of the keypad  130 .  
         [0049]    The key actuator assembly  133  is of the same construction as that on an IBM A20m ThinkPad laptop computer and is designed so that application of a force to its leading edge  145  will actuate the key and generate an electronic code such as an ASCII code. Other types and manufactures of keys will also work and it will be obvious to one skilled in mechanical and keyboard design how to implement them in the keypad  130 . Application of a downward force  146  to the leading edge  131  portion of the first planar element  126  of the key top  127  applies a force to the second planar element  128 . Because the leading edge  131  of the first planar element  126  is cantilevered past the pivot point formed by the pin  137  at the leading edge  144  of the second planar element  128 , the pin  137  will form a fulcrum and an upward force will be transferred to the trailing edge  121  of the key top  127  which will in turn push the peg  135  against the upper part of the bracket  134  and transfer a downward force to the key actuator assembly  133  causing it to depress and actuate. Many other designs of a key mechanism that will transfer force from cantilevered first planar element  126  to key actuator assembly  133  will be obvious to designers of mechanical devices.  
         [0050]    [0050]FIG. 3B shows an exploded view of the keypad  130  of FIG. 3A. It is intended to be oriented so that the top surface  141  of the key tops  127  are horizontal when in use, although different users may have different preferences. This embodiment is not a particular type of keypad or keyboard, but a structure that can be used for keypads or keyboards for any application, such as for a desktop keyboard, a telephone number pad or a calculator The electronics (not shown) can be on either side of key support  124 , or could be on a separate board to which key actuator assemblies  133  are wired. It will be obvious to any skilled in the art of keyboard design how to construct the electronics for the keypad  130 , and in fact it may be possible to use the key support  124  and key actuator mechanism  133  assembly from a prior art keypad with the same footprint. Eighteen key actuator assemblies  133  are mounted on the top surface  147  of the key support  124  in first  151 , second  152  and third  153  laterally extending parallel rows of six equally spaced key actuator assemblies  133 . The first and third lateral rows  151  &amp;  153  are aligned longitudinally, and the second lateral row  152  is offset from the first and third lateral rows  151  &amp;  153  by approximately one-half the distance between the center points of two adjacent keys in the same row. The rows  151 ,  152  &amp;  153  are offset longitudinally by a distance which is a function of the angle  142  (see FIG. 3A) and the desired footprint (the longitudinal and lateral dimensions only) and layout of the keypad.  
         [0051]    Pairs of c-brackets  134  are arrayed on the top surface  146  of the key support  124  in an identical arrangement, with the two brackets  134  centered around a longitudinal axis bisecting the key actuator assembly  133  and offset longitudinally by a distance determined by the size and construction of the key tops  127 . The two brackets  134  of each pair of brackets  148  are separated by a lateral distance slightly greater than the lateral dimension at the trailing end  121  of the key tops  127  so that it moves freely therebetween. The pegs  135  of the key tops  127  are inserted into the c-brackets  148  and the leading edge  144  of the second element  126  of each key top is pivotably attached to the leading edge  143  of one of the key actuator assemblies  133  using a pin  137 . The leading edges  131  of the key tops  127  are threaded through the key slots  151  in the optional cover  136 . Other designs of key tops  127  are easily within the capability of one skilled in the art. The key actuation mechanism  133  can be of any kind, including a membrane switch.  
         [0052]    [0052]FIGS. 4A, 4B &amp;  4 C show different views of a keypad  160  that is very similar to the keypad  130  of FIGS. 3A &amp; 3B, differing primarily only in the type of key top. The key top  161  is not a cantilevered key but is shaped instead like an extruded triangle with slightly flattened corners  171 . The key top  161  is oriented with the triangle-shaped sides orthogonal to the lateral axis of the keypad  160 . Pivot pegs  167  extend laterally from the triangular sides  172  at the trailing edge  174  of the key top  161  and when the keypad  160  is assembled the pegs  167  are pivotably engaged in the brackets  166  such that the key top  161  can pivot around the pegs  167  in a longitudinal arc. At the leading edge  173  of the key top  161 , a nub  168  protrudes downward and is in contact with a membrane-type key actuation mechanism  170  (other key actuation mechanisms will also work such as the key actuation mechanism  133  of the keypad  130  of FIG. 3A). In some embodiments, the key top  161  can be attached to the key actuation mechanism  170  and there can be springs to provide the touch typing feel. FIGS. 4A, 4B &amp;  4 C are not detailed but the operation and design of the keypad  160  will be obvious to one skilled in the art after the detailed description given of the keypad  130  of FIGS. 3A &amp; 3B. Because of the pivoting design of the key mechanism of the keypad  160 , no matter whether the keypad  160  is inclined (as shown in FIG. 4A) or flat (as shown in FIG. 4B) pressing down the key activation edge  176  of the key top  161  will cause the key top  161  to pivot around the pegs  167  in the brackets  166  and will cause the nub  168  to actuate key actuation mechanism  170 . Thus, the keypad  160  has the additional advantage that it can be operated in both an inclined orientation where there will be a vertical differential  178  between the trailing face  177  (now oriented facing upwards) of the key top  161  of a key in a first row  162  and the trailing face  177  of the key top  161  of a key in a second, lower row  163 .  
         [0053]    The key top  161  has an additional advantage when it is in use in the flat orientation shown in FIG. 4B. The triangular shape of the key top  161  when the key activation edge  176  is oriented vertically accentuates the tactile sensation of the key and makes it easier for a user to feel the key and differentiate it from other keys. It also increases the effective distance between keys in the longitudinal direction. An alternate embodiment has a key top  161  that is shaped like a pyramid and the key activation edge  176  becomes a point, which has the effect of increasing the effective physical distance of a particular key from all adjacent keys, whether in the inclined or flat orientation.  
         [0054]    [0054]FIG. 4C shows an exploded perspective view of the keypad  160  and is self-explanatory to one skilled in the art of keyboard design after reading the description accompanying FIG. 3B. The wiring of the keys is not shown but will be obvious to one skilled in the art. It will be clear to one skilled in the art after a moments reflection, that since the actuation of the keys occurs approximately orthogonal to the key support  164 , the key actuation mechanism  170  can be any of the many key actuation mechanisms used in prior art keyboards and the wiring layout can be the same. In fact, a prior art keyboard can most often be converted to the dual orientation keypad of FIGS. 4A, 4B and  4 C simply by substituting a different key top for the prior art key top. Prior art key tops, however, are designed for actuation by a finger tangential to the key top, and are therefore inappropriate for dual orientation use. The perspective view of the key top  161  is shown. In FIGS. 4A &amp; 4B, a finger  48  is shown pressing a key for illustrative purposes. The keypad  160  can be integrated into any electronic device (such as a handheld computer) such that the keyboards orientation is changed by rotating the device around a lateral axis, or it can be incorporated into a keyboard assembly of that device that has at least two stable positions: inclined and flat. On some devices it may be desirable to have the keypad along the side of the device in an assembly that can be rotated into an inclined or even flat position.  
         [0055]    [0055]FIG. 4D shows the keypad  160  in the stored state against the side or end  182  of a handheld device  180  and FIG. 4E shows the keypad  160  lifted away from the side or end  182  and into an inclined position for use. The keypad  160  pivots around a hinge  183  by which it is attached at its back edge  184 . On the underside of the keypad  160  near its front edge  185 , a support arm  181  is attached. The support arm  181  retracts into a channel (not shown) the housing of the device  180  and has at least two stable positions: the fully retracted position for keypad storage shown in FIG. 4D and a partially extended position shown in FIG. 4E that holds the keypad  160  in an inclined orientation for use. The accomplishment of this adjustable leaf (as in a table leaf) structure and the electronic connection of the keypad  160  to the device  180  will be simple for one skilled in the design of mechanical devices and keyboards.  
         [0056]    [0056]FIG. 5A shows four of the many options for the shape of the key top  127  for use with the cantilevered keypad  130  shown in FIGS. 3A &amp; 3B. The key leading edges  191  are the portion of the key top that will be oriented towards the user and with which the user&#39;s finger will be in contact. Note that it is the narrowest part of the key tops  190  and  192 . By narrowing the leading edge  191  of the key tops  190  &amp;  192 , the effective distance between two adjacent keys in the same row is increased and the tactile distinctness of individual keys is enhanced.  
         [0057]    [0057]FIG. 5B is a view from underneath a keypad  195  to illustrate the interaction between a finger  48  and the key top  190  of FIG. SA. This is an unrealistic view in that none of the structures that would normally obstruct this view have been included. Note that because the closest edges  196  &amp;  197  of the adjacent keys  193  &amp;  199  are inclined away from the longitudinal axis of the key  187  being pressed, the effective separation distance  189  (i.e. between the closest edges of first and second keys separated by a third key in the same row) between the key  187  and the adjacent keys  193  &amp;  199 , and therefore the space available for the tip  198  of the finger  48 , is increased. The effective separation from one key and its neighbor is the distance  188 . The tip  198  of the finger  48  is able to press on the key top  190  at the point of contact  194  without touching the adjacent keys  193  &amp;  199 . If the key tops of the keypad  195  were instead the key tops  127  of FIG. 3A &amp; 3B, the tip  198  of finger  48  would not be able to press the key  187  without also pressing the adjacent keys  193  &amp;  199 .  
         [0058]    [0058]FIG. 6 is a top view of a miniature low-aspect ratio alphanumeric keyboard  200  having cantilevered key tops  202  of the cross-sectional shape  190  shown in. FIG. 5A &amp; 5B having the construction of the cantilevered key keyboard shown in FIGS. 3A &amp; 3B. An illustration of a section of a prior art keyboard  201  is included to emphasize how much the decrease in the aspect ratio from approximately 1:1 to 1:2 makes in the size of the keyboard  200 . A finger  48  is shown typing a letter “K” key  203  on both the keyboard  200  of the present invention and the miniature prior art keyboard  201  (found on Blackberry and Handspring PDAs and on the Palm Mini Keyboard peripheral) to show how much better the visibility of the keys is on the keyboard  200  the keyboard of the present invention with the rows at different vertical heights and the keys narrowed at the end towards the user. Notice that you can actually still see a portion of the letter “K” key  203  when typing using the keyboard  200  (and importantly you can see adjacent keys “J” and “L” in the same row clearly) while you cannot even see the adjacent keys are when typing on the Prior Art keyboard 2001.  
         [0059]    [0059]FIG. 7 is a side (longitudinal) view of a keypad  220  of the present invention in which the vertical differential between the planes of the different rows is accomplished by using key tops  226  of differing thicknesses for each row. The keypad  220  has a planar key support  224  on which are arranged a plurality of keys  226  in first  231 , second  232 , third  233  and fourth  234  parallel rows aligned with the lateral axis of the keypad  220 . The keys  226  in each row are spaced evenly and comprise a key top  230  and a key actuation mechanism  228 . The layout of the keys  226 , the electrical wiring and all the components except the key tops  230  can be identical to that of any prior art keyboard of any size. The key tops  241 ,  242 ,  243  and  244  of the keypad  220  have the same horizontal cross-sectional dimensions as the prior art key tops.  
         [0060]    The keys  226  in the first row  231  have a first key top  241 , in the second row  232  have a second key top  242 , in the third row  233  have a third key top  243 , and in the fourth row  234  have a fourth key top  244 . The key tops  241 ,  242 ,  243  and  244  have a dimension height  246  measured along the keys  226  vertical axis from the bottommost edge  247  of the key top  230  to the topmost edge  249  of the key top  230 . The first key top  241  has a first vertical dimension  251 . The second key top  242  has a second vertical dimension  252  that is greater than the first vertical dimension  251 . The third key top  243  has a third vertical dimension  253  that is greater than the second vertical dimension  252 . The fourth key top  244  has a fourth vertical dimension  254  that is greater than the third vertical dimension  253 . The resulting keyboard has keys  226  in rows of ever increasing height as the rows get further from the user in the longitudinal direction. This embodiment of the present invention enables one to convert any prior art keyboard into a keyboard of the present invention merely by swapping the standard single-height keys of the prior art keyboard for sets of key tops  230  of different heights.  
         [0061]    [0061]FIGS. 8A, 8B and  8 C three views of the same embodiment of a keypad of the present invention which is a variation of the keypad  300  in FIG. 7 with key tops of multiple heights. As with drawings of other embodiments already discussed, the figures show the basic design of the keypad which can be applied to a keypad of any layout and type. The keypad  300  consists of twenty-eight keys  302  arranged in two rows of five keys each nested between three rows of six keys each on a key support  306 . FIG. 8A shows a longitudinal side view of the keys  302  are laid out in first  311 , second  312 , third  313 , fourth  314  and fifth  315  rows of keys  302  aligned with the lateral axis of keypad  300 . The keys  302  comprise a key actuation mechanism  305  and a key top  301 . The key tops  301  are square but the keys  302  are rotated ninety degrees so that the key tops  301  appear to be a diamond shape when viewed from the longitudinally or laterally. The keys  302  in the first row  311  have a first key top  321 , the keys  302  in the second row  312  have a second key top  322 , the keys  302  in the third row  313  have a third key top  323 , The keys  302  in the fourth row  314  have a fourth key top  324 , and the keys  302  in the fifth row  315  have a fifth key top  325 . The key tops  301  have a vertical dimension (as shown in FIG. 7) and the vertical dimension of the fifth key top  325  is greater than that of the fourth key top  324  which is greater than that of the third key top  323  which is greater than that of the second key top  322  which is greater than that of the first key to  321  to create a set of five staggered rows with heights increasing from the front  308  of the keypad  300  to the back  307  of the keypad  300 . An optional cover  309  has the same incline as a plane intersecting all the keys at the center of the top of the keys.  
         [0062]    [0062]FIG. 8B is a top view of the keypad  300 . The key tops have four vertical sides, and have a longitudinal axis  332  and a lateral axis  330 . Adjacent keys  302  in the same row are aligned along their lateral axes while keys in alternating rows are aligned along their longitudinal axes. The second  312  and fourth  314  rows are nested between the first  31   1 , third  313  and fifth  315  rows such that the back faces  334  &amp;  335  of a key  339  in a nested row are in contact with the right-oriented front face  336  of the key  340  in the next row back to the immediate left and the left-oriented front face  337  of the key  341  in the next row back to its immediate right. The same is true of all keys except those in the fifth row  315 . The key tops  321 ,  322 ,  323 ,  324  &amp;  325  are sized so that there is a minimal gap between their adjacent faces. The height differential between the faces of a nested key and the adjacent keys in the row immediately behind create two-walled corner  342  at the back of each nested key (see FIG. 8C also for perspective view). FIG. 8C is a perspective view of the keypad of FIGS. 8A &amp; 8B, and clearly shows the advantage of this embodiment. The corner  242  provides a “trap” for a stylus  360  while the diamond shape of the key top  301  has the same advantage that the key top  190  conferred on the keypad  195  in FIG. 5B and the keypad  200  in FIG. 6, that of increasing the effective separation of the keys to make inadvertent multiple key strikes easier to avoid.  
         [0063]    Standard key actuation mechanisms can be used for the keypad  300  simply by rotating the key mechanism forty-five degrees.  
         [0064]    [0064]FIG. 15 shows an embodiments of the present invention as peripheral devices for portable electronic device  70 , which could be a handheld computer, PDA or other portable electronic device).  
         [0065]    [0065]FIG. 9A is for illustrative purposes and shows a low-aspect ratio peripheral keyboard  400  of the present invention for attachment to a PDA or handheld computer  401  through the hot sync port. Note that the keyboard  400  is significantly wider will therefore be easier to type, yet is not much bigger than existing peripherals. The keyboard  200  of FIG. 6 could easily be made into a peripheral keyboard that would be one-half the size of the Palm Mini Keyboard peripheral. FIG. 9B is a side view stylized silhouette of the keyboard  400  for illustrative purposes.  
         [0066]    [0066]FIG. 10A is a keyboard of the present invention incorporated into the long side of a cell phone/PDA combination such as the Ericcson R380E showing how the vertically staggered rows, low-aspect ratio and pointed keys of the present invention make it possible to incorporate a usable keyboard in a place where no prior art keyboard could possible fit, nor would any keyboard designer even consider doing so.