Note: Descriptions are shown in the official language in which they were submitted.
CA 02517815 2001-09-19
Hand-Held Electronic Device with a Keyboard Optimized for Use with the Thumbs
BACKGROUND
The present invention is directed toward the field of small, hand-held
electronic devices such
as personal data assistants (PDAs), personal information managers (PIMs), two-
way pagers and the
like. In particular, the system and method of the present invention provide
the user of the hand-held
device with the ability to input data with a minimal amount of key strokes,
and includes a keyboard
structure that is optimized for use substantially with the thumbs.
In a two-way paging system that provides two-way, full text messaging, there
is a need to
permit the user to initiate messages and to respond to messages in a timely
fashion and with text
entirely created by the user. In order to keep the form factor of the two-way
pager small enough to
be worn on the body of the user, such as with a belt clip, the input device
needs to be small, have a
minimal number of keys, and be optimized for use with a minimal number of key
strokes. Prior art
systems have attempted to address these needs by incorporating virtual
keyboards or pen-based input
systems for user inputs to the device, but such systems require the user to
input data in an unfamiliar
manner. Additionally, in a small hand-held messaging device, such as a two-way
pager, these
systems prove awkward to use.
In order to provide a hand-held electronic device that permits a user the
opportunity to enter
data into an address book, a calendar, a task list, an email message or a
similar text file that requires
user-generated data, the present invention includes an input device that is
oriented to be used
substantially through use of the thumbs. This is accomplished first by
providing a keyboard with a
minimal number of keys, but with the keys representing the alphabet generally
placed in the same
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order as they would appear on a standard keyboard, such as in a standard
QWERTY or a DVORAK
keyboard layout. The use of a keyboard layout that is familiar to the user
enables the user to
immediately use the device without having to hunt for the keys he or she
wishes to use.
Although the layout is similar to a standard keyboard, the keys are placed at
an orientation
and in a particular shape that attempts to maximize the surface area of the
thumb hitting the key and
to provide the user with a comfortable position of the hands for data input.
Also, the orientation
encourages input by the thumbs, which the inventors of the present invention
have discovered to be
faster and more accurate in small hand-held electronic devices than touch-
typing or "hunting and
pecking" typing.
An additional feature of the invention is thus the use of an additional input
means for control
of functions that might otherwise be controlled by a keyboard that included
function keys. To
encourage data entry using thumbs and again to minimize the number of keys on
the keyboard, the
present invention also includes a thumb-wheel for control of menus to select
forms and functions
relevant to data input. The thumb-wheel is preferably positioned in close
proximity to the keyboard
to enable the easy transition from thumb-based typing to thumb control of
forms and functions via
the thumb-wheel.
In addition to. hardware features that encourage optimal data entry through
the use of thumbs,
the present invention provides several software features that are designed to
minimize keystrokes and
aid data entry.
The features of this invention, both individually and collectively, have not,
to the knowledge
of the inventors, been applied to a small hand-held electronic device that
requires user-generated data
entry. To permit efficient operation of such devices, while keeping the form
factor of the device
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small enough to be worn on the body, there is a general need for a hand-held
electronic device that
can fit in the palm of the hand and that can be operated substantially with
the thumbs.
There is a further need for a keyboard for a palm-size data entry device with
keys having a
characteristic length, for instance the side or diagonal of a polygon, the
major or minor axis of an
ellipse, or the diameter of a circle, preferably placed at an angle to
optimize operation of the
keyboard by the use of the thumbs.
There remains another need for a keyboard with keys that are shaped and sized
to maximize
contact with the thumbs while minimizing the keyboard area required for such
keys.
There also remains a need for an auxiliary input device that is to be operated
by the thumb for
data inputs of forms and function control and that, in conjunction with the
keyboard, encourages and
permits data entry and management through input performed substantially by the
thumbs.
There remains still another need for a software-implemented user interface
system that is
designed, at least in part, to support and encourage data entry through use of
the thumbs.
SUMMARY
The present invention overcomes the problems noted above and satisfies the
needs in this
field for a hand-held electronic device with a keyboard optimized for use with
the thumbs. In the
preferred embodiment of the present invention, the hand-held electronic device
is a two-way paging
device that permits full-text, two-way messaging such as email messaging, and
that includes standard
PDA or PIM features, such as an address book, an electronic calendar, a task
list and other text-based
features. These features require user input of text strings that can be
lengthy and that cannot be
reduced to pre-determined or "canned" strings. Thus, for such a device, the
efficient entry of data in
a device meant to fit into the palm of one's hand requires that two goals are
achieved. First, the data
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entry must be relatively easy from a user perspective. This means that the
user must be somewhat
familiar with analogous forms of data entry and does not have to be trained to
use the data entry for
the hand-held device. Second, the form factor does not permit a large number
of keys or keys that
are very large. Thus, efficient use of the keyboard space is required and
functions that might be able
to be performed by a standard keyboard are off-loaded to an auxiliary input
device, such as a thumb-
wheel, joystick, arrow keypad or telephone/numeric keypad, or are performed
through a minimal
number of keystrokes that encourage the use of thumb-based data entry.To
accomplish these goals,
the invention first optimizes the placement of the keys on the device
keyboard. In order to work
within the limited space available for the keyboard, it was determined that it
was preferable to use
keys that were oval or oblong, as this shape is characteristic of the area of
thumb-impact that a thumb
makes with any flat surface held by the hand, and that were placed at angles
characteristic of the
complementary and opposable nature of the left and right thumbs, designed to
facilitate use by thumb
typing with both hands. An angle for the keys on the right side of the
keyboard and a complementary
angle for the keys on the left side of the keyboard are chosen based upon
observation of the angle at
which a user will orient his or her thumbs while thumb-typing. The optimal
orientation of each key
maximizes the surface area of the thumb-impact oval. The optimal shape of each
key minimizes
overall keyboard footprint. The optimal layout of the keys is in a radial
fashion characteristic of the
radial trajectories that are naturally taken by the tip of the thumb moved
over the keyboard of the
electronic device when held.
Alternatively, however, other keyboard designs could be employed using other
shapes for the
keys, other orientations, and other layouts Many shapes allow for an oval
representing the area of
thumb-impact to be circumscribed within it's boundaries at complementary
angles depending on
whether the key is on the left or right side of the keyboard. For instance,
for a rectangular shaped key,
CA 02517815 2001-09-19
an oval can be circumscribed in at least four ways: with major axis coinciding
with the horizontal
line bisecting the rectangle thru its center, with major axis coinciding with
the vertical line bisecting
the rectangle thru its center, and with major axis coinciding with either one
of the two diagonals
extending from opposite comers. Alternate shapes, orientations, and layouts
are less efficient
embodiments of a thumb-typing keyboard.
The invention also minimizes the number of keys available for data input. In
the preferred
embodiment, only keys for the 26 letters of the English alphabet are available
on the keyboard, as
well as a backspace key, a line feed key, an "alt" key, a "cap" key and a
space bar. The alt key
enables the user, in conjunction with the other keys, to input numbers and
symbols to perform certain
functions. The placement of the keys is designed to enhance the user
experience while typing with
the thumbs by meeting two seemingly opposite goals - minimizing the keyboard
footprint while
maximizing the likelihood that proper keys will be struck by the thumb-typing
user.
To further limit the space occupied by the keyboard and facilitate thumb
typing, the keys on
the keyboard are preferably arranged in arced rows. In a preferred embodiment,
the rows of keys
have respective radii increasing from a lower row near the bottom of the
keyboard towards an upper
row near the top of the keyboard. The keyboard rows may also be concentric.
The respective keys in each arced row may be angled to a vertical reference
bisecting the key,
or may be oriented normal to the vertical reference. In addition, the keys in
the respective arced rows
may be oriented along a common set of vertical references, or they may be
offset from each other.
The invention also provides additional incentive for the user to use thumb
input by providing
an input device adjacent to the keyboard, but integral to the overall hand-
held device. Although
other devices can be used in an auxiliary fashion, such as a thumb-wheel,
arrow keypad or
telephone/numeric keypad, the preferred device is a thumb-wheel that registers
movement of the
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wheel by measuring the number of indents traversed while rolling the wheel and
that also
registers as an input the depression or "clicking" of the wheel, which is
performed by
pressing the wheel toward the back of the pager. This clicking of the wheel is
similar to
the clicking of a mouse associated with a PC or any other input device that
registers the
depression of a button. The thumb-wheel in the preferred embodiment is placed
vertically
on the two-way paging device so that the user can easily move his or her thumb
from the
thumb-wheel to the keyboard and back for performing functions and retrieving
data forms,
such as an e-mail template or address book entry template, for data entry.
Additionally, various software techniques can be implemented to enhance the
user's thumb-typing experience in using the device of the present invention.
In the
preferred embodiment, for example, the user can change the capitalization of a
particular
letter simply by keeping a key depressed for a particular length of time
without an
intermittent release being detected by the keyboard controller.
The primary advantage of the present invention is that it enables efficient
and user-
friendly data entry into a palm-sized electronic device by maximizing the
potential for user
data entry through thumb typing.
In one aspect of the invention, there is provided an electronic device
optimally
configured for use with the thumbs of a user comprising a keyboard comprising
a plurality
of keys arranged in a plurality of rows, each of the rows of keys defining a
respective arc
along which said keys are positioned,a plurality of keys, spanning the
plurality of rows,
aligned symmetrically along a plurality of space-apart vertical references
thereby forming
a plurality of aligned key columns, a return key positioned in a right-side
aligned key
column, a display operatively associated with the keyboard, and a
microprocessor to
control the operation of the device.
In another aspect of the invention, there is provided an electronic device
optimally
configured to facilitate user thumb-typing with thumbs comprising a keyboard
comprising
a plurality of keys arranged in a plurality of concentric rows, each of the
rows of keys
defining a respective arc along which said keys are positioned; a plurality of
keys,
spanning the plurality of rows, aligned symmetrically along a plurality of
spaced apart
vertical references thereby forming a plurality of aligned key columns and
defining a right
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hand group of keys and a left hand group of keys, the keys of the right hand
group tilted at
a first positive angle relative to a vertical reference and the keys of the
left hand group
tilted at a second negative angle relative to the vertical reference; a
display operatively
associated with the keyboard; and a microprocessor to control the operation of
the device.
In yet another aspect of the invention, there is provided a hand held
electronic
communication device, comprising a device housing having a top face with a top
edge, a
bottom edge, a left edge and a right edge; a display for displaying messages
received by
the device; and a keyboard for composing text messages to be transmitted by
the device,
the keyboard having twenty-six letter keys each of which bears the designation
of at least
one letter and at least one other key, the letter keys being arranged in an
upper row
including 10 letter keys, a middle row including 9 letter keys and a lower row
including 7
letter keys, the letter keys in the upper row being distributed from adjacent
the left edge
across the top surface to adjacent the right edge; each letter key in the
lower row being in
substantial vertical alignment with a letter key in the middle row, each
letter key in the
middle row being in substantial vertical alignment with a letter key in the
upper row, five
letter keys in each of the upper row and the middle row being disposed on the
same side of
a vertical reference line substantially midway between the left edge and the
right edge.
There are just a few of the many advantages of the present invention, as
described
in more detail below. As will be appreciated, the invention is capable of
other and
different embodiments and its several details are capable of modifications in
various
respects, all without departing from the spirit of the invention. Accordingly,
the drawings
and description of the preferred embodiment set forth below are to be regarded
as
illustrative in nature and not restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention satisfies the needs noted above as will become apparent
from the
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following description when read in conjunction with the accompanying drawings
wherein:
FIG.1 is a block diagram of a two-way, full-text, messaging device
incorporating a keyboard
and an auxiliary data entry device;
FIG. 2 is a frontal view of the hand-held device showing the shape and
placement of the keys
on the keyboard and the auxiliary input device;
FIG. 3 is a diagram of showing the shape, size and placement of the keys on
the keyboard;
FIG. 4 is a diagram of the control circuitry for the thumb-wheel;
FIG. 5 is a diagram showing a first embodiment of a keyboard according to the
present
invention;
FIG. 6 is a diagram showing a second embodiment of a keyboard according to the
present
invention;
FIG. 6a is an alternative embodiment of the second embodiment illustrated in
FIG. 6;
FIG. 7 is a diagram showing a third embodiment of a keyboard according to the
present
invention;
FIG. 8 is a diagram showing a fourth embodiment of a keyboard according to the
present
invention;
FIG. 9 is a diagram showing a fifth embodiment of a keyboard according to the
present
invention;
FIG. 10 is a diagram showing a sixth embodiment of a keyboard according to the
present
invention;
FIG. 11 is a diagram showing a seventh embodiment of a keyboard according to
the present
invention;
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FIG. 12 is a diagram showing an eighth embodiment of a keyboard according to
the present
invention;
FIGS. 13a to Of are diagrams illustrating the trajectory and radial movement
of thumb typing
using one electronic device; and,
FIGS. 14a to 14c are diagrams showing an alternative electronic handheld
device
implementing one embodiment of the keyboard layout invention.
DETAILED DESCRIPTION OF THE DRAWINGS
Referring now to the drawings, FIG. 1 is a block diagram of the major
subsystems and
elements comprising a palm-sized, mobile, two-way messaging device that
preferably incorporates
the invention. In its broadest terms, the messaging device includes a
transmitter/receiver subsystem
100 connected to a DSP 200 for digital signal processing of the incoming and
outgoing data
transmissions, power supply and management subsystem 300, which supplies and
manages power to
the overall messaging device components, microprocessor 400, which is
preferably an X86
architecture processor, which controls the operation of the messaging device,
display 500, which is
preferably a full graphic LCD, FLASH memory 600, RAM 700, serial port 800,
keyboard 900,
thumb-wheel 1000 and thumb-wheel control logic 1010.
In its intended use, a message comes to the device via a wireless data
network, such as the
Mobitex network, into subsystem 100, where it is demodulated via DSP 200 and
decoded and
presented to microprocessor 300 for display on display 500. To access the
display of the message,
the user may choose from functions listed under a menu presented as a result
of user interaction with
thumb-wheel 1000. If the message is an email message, then the user may choose
to respond to the
email by selecting "Reply" from a menu presented on the display through
interaction via thumb-
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wheel 1000 or via menu selection from keyboard 900. In typing the reply, the
user can use keyboard
900 to type full text message replies, or insert pre-determined or "canned"
responses by using either
a particular keystroke pattern or through pulling down pre-determined text
strings from a menu of
items presented on display 500 through the use of thumb-wheel 1000.
When the reply to the message is composed, the user can initiate the sending
of the message
preferably by interaction through thumb-wheel 1000, or alternatively, with
less efficiency, through a
combination of keyboard 900 keystrokes. When the microprocessor 300 receives
an indication that
the message is to be sent, it processes the message for transport and, by
directing and communicating
with transmitter/receiver subsystem 100, enables the reply message to be sent
via the wireless
communications data network to the intended recipient. Similar interaction
through YO devices
keyboard 900 and thumb-wheel 1000 can be used to initiate full-text messages
or to forward
messages to another party.
In addition, the keyboard 900 and thumb-wheel 1000 can be used to permit data
entry to an
address book resident on the messaging device, or an electronic calendar or
log book, or any other
function on the messaging device requiring data entry. Preferably, the thumb-
wheel is a thumb-
wheel with a push button SPST switch with quadrature signal outputs, such as
that manufactured by
Matsushita Electronic Components Co. Ltd. as part number EVQWK2001.
FIG. 2 is a front view of messaging device 10 that incorporates the invention.
Shown in FIG.
2 are a plurality of letter keys 901, specialized keys 902, 903, 904 and 905,
and space bar 906. Also
shown is thumb-wheel 1000 in its vertical orientation and in association with
display 500 and
keyboard 900. In the preferred embodiment, key 902 is the alt key, key 903 is
the cap key, key 904 is
the line feed key, and key 905 is the backspace key. Other configurations of
these keys are also
possible.
CA 02517815 2001-09-19
FIG. 2 also shows the arrangement of keys on the keyboard into multiple rows.
Each of the
rows defines an arc along which the keys are positioned. Such an arrangement
of the keys not only
facilitates thumb typing by a user but also reduces the space occupied by the
keyboard. The arced
rows of keys shown in FIG. 2 allow for location of the space bar 906 in its
conventional keyboard
position but reduce the amount of unoccupied space at the ends of the space
bar.
Although FIG. 2 shows a preferred embodiment of a messaging device 10, other
implementations incorporating alternate device architectures are also
contemplated. For example,
different curvatures of the arced rows could be employed to accommodate keys
on the keyboard
between rows either in addition to or instead of only at the bottom of the
keyboard in the position of
the space bar shown in FIG. 2. In addition, many different shapes and
orientations of the keys could
also be utilized, as is further detailed below with respect to FIGS. 5-12.
Similar keyboard layouts
would also be suitable for use in other electronic devices with different
display arrangements.
Electronic devices having clamshell type designs, such as the Research in
Motion (RIM')
Inter@ctiveTm Pager, in which the display is positioned on a movable cover
portion of the device
which is attached to the keyboard portion with a hinge, represent one such
alternate keyboard/display
arrangement. It is well within the scope of the present invention to include
the inventive keyboard
on a variety of handheld electronic devices such handheld electronic arcade
devices; two-way pagers;
wireless data communication devices; cell phones; and Personal
FIG. 3 is a view of a subset of the letter keys 901, showing the preferred
dimensions and
relative positions of the keys. Also shown is the point 950 that marks the
center of keyboard 900,
key dimensions 970, 971, 972 and 973, as well as angle 960 and the rho value
965, representing
curvature of a letter key 901. In investigating optimal key placement on the
keyboard, it was
determined that the keys should be placed at an angle 960 relative to a
vertical reference bisecting the
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key that facilitated easy typing using thumbs. That angle is preferably
positive 40 degrees relative to
the vertical reference for keys on the right side of the keyboard (where 950
is the center of the
keyboard), and negative 40 degrees for the keys on the left side of the
keyboard. However,
complementary angles ranging from 20 degrees to 70 degrees could also be used
to accomplish the
goal, albeit less optimally, of facilitating thumb typing.
As is also shown on FIG.s 2 and 3, the keys 901 are dispersed across keyboard
900 evenly so
that there is sufficient space between the keys to decrease the opportunity
for multiple keys being
depressed while thumb typing. Additionally, the keys 901 are sized
appropriately given the footprint
of the messaging device and the keyboard 900. In its preferred embodiment, the
messaging device
measures 64 mm by 89mm across its face, which does not leave much room for
keyboard 900 and
display 500. In the preferred embodiment, keyboard 900 occupies over half of
the face of the
messaging device 10.
The key shape and dimensions are also key components of the invention. In
order to
maximize the surface area of the key that a thumb would hit, the keys are
preferably oval, and have a
rho 965 defining the curvature of the key of .414, although values may range
higher or lower. Other
rho values will lead to an acceptable, but not as optimal, or aesthetically
pleasing, shape of keys 901.
As to the key dimensions, the width 970 of the key 901 is 4.8 millimeters (971
representing the
radius of half that value, 2.4 mm) and the length (or height) 972 of the key
901 is 7 millimeters (973
representing the radius of half that value, 3.5 mm). Although oval is the
preferred shape for keys
901, as shown in FIGS. 5-12, other shapes are also possible as they can
circumscribe an oval
representing the thumb-impact area.
One of the software features that aids in the device 10 being optimally used
for thumb typing
is a capitalization feature. Using this feature, if a user depresses a key
901, then the operating system
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detects a key down event. If the key is released after a period of time, the
operating system detects a
key up event. If, upon a key down event, a period of time elapses before a key
up event is detected,
then the operating system determines that a key repeat event has occurred
representing a situation
where a user has continued to depress a key without releasing it. A key repeat
event is then treated
by application software residing in either FLASH 600 or RAM 700 as an event
that requires the
capitalization of the key previously depressed. This feature disables a key
repeat feature and
substitutes instead a capitalization feature based upon a key repeat. The
timing of the key scanning
to determine whether a key has been released can be set to permit a slower
keyboard response or a
faster keyboard response, depending upon user experience or preferences.
Although the capitalization function preferably works only to change the state
of a letter to a
capital, it alternatively could operate to change a capital letter to a lower
case letter. The actual
display is changed by the application program substituting the value of the
capital letter in the.
register that holds the value of the letter to be displayed. As alternatively
implemented, the
continued depressing without release of a letter key could result in a key
oscillating between upper
case and lower case, depending on the length of time the key is depressed.
FIG. 4 is the logic circuitry 1010 associated with thumb-wheel 1000. Thumb-
wheel 1000
outputs quadrature signals phase A 1021 and phase B 1022, which are processed
by D flip-flops
1031 and 1032 to present signals 1041 W_UP and 1042 W DN to microprocessor
300. Signals
1041 and 1042 represent, respectively, a user rolling the thumb-wheel up and
rolling the thumb-
wheel down.
FIG. 5 is a diagram showing a first embodiment of a keyboard according to the
present
invention. This keyboard includes a plurality of letter keys 901 (A-Z),
several function keys 902,
903, 904, and a spacebar/symbol selector 906. The respective keys 901 are
preferably organized into
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three arced rows 910, 912, 914. The first arced row 910 includes the function
keys 902, 903, and the
letter keys 901 Z, X, C, V, B, N, and M, just like on the first row of a
standard QWERTY keyboard.
The degree of arcing of the first arced row 910 is preferably defined by a
first radius R1. The
second arced row 912 includes the function key 904, and the letter keys 901 A,
S, D, F, G, H, J, K
and L, just like on the second row of a standard QWERTY keyboard. The degree
of arcing of the
second arced row 912 is preferably defined by a second radius R2. The third
arced row 914 includes
the letter keys 901 Q, W, E, R, T, Y, U, I, O and P, just like on the third
row of a standard QWERTY
keyboard. The degree of arcing of the third arced row 914 is preferably
defined by a third radius R3.
For the preferred three-row organization shown in FIG. 5, the first radius R1
of the first arced
row 910 is preferably less than the second radius R2 of the second arced row
912, which is
preferably less than the third radius R3 of the third arced row 914. These
radii RI, R2, R3 may
define a set of concentric circles on which the arced rows of keys 910, 912,
914 are placed. Other
configurations and orientations of the arced rows of keys are also possible.
Also shown in FIG. 5 are a set of vertical references 916. Each of these
vertical references
916 bisects one or more (up to three) of the letter keys 901 making up the
keyboard. In the
embodiment shown in FIG. 5, the keys 901 are preferably oval-shaped, and are
oriented at an angle
with respect to the vertical references 916. The keys on the right-hand side
of the keyboard are
preferably oriented at a first predetermined angle 918, and the keys on the
left-hand side of the
keyboard are preferably oriented at a second predetermined angle 920. The
first predetermined angle
918 is preferably a positive angle with respect to the vertical reference 916,
and the second
predetermined angle 920 is preferably a negative angle with respect to the
vertical reference 916.
These first and second predetermined angles 918, 920 are preferably
complementary angles, for
example +/- 40 degrees from vertical. As discussed above, a range of angles is
possible.
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The keys 901 in FIG. 5 are also preferably aligned along the set of vertical
references 916,
such that a key in the first row is aligned with a key in the second row,
which is aligned with a key in
the third row. For example, the N key in the first row 910 is aligned with the
J key in the second row
912 and the U key in the third row 914.
The optimal layout of the keys is in a radial fashion characteristic of the
radial trajectories
that are naturally taken by the tip of the thumb moved over the keyboard of
the electronic device
when held as shown in Figs. 13a -13f. These figures help to illustrate sample
movements of the
thumbs over the keyboard. As shown, the thumbs 930 of the user easily follows
the circumferential
paths 910, 912, and 914 and the vertical references 916 to efficiently and
quickly enter input into the
small keyboard with his thumbs.
FIG. 6 is a diagram showing a second embodiment of a keyboard according to the
present
invention. This embodiment is similar to FIG. 5, except that the keys 901 in
each arced row 910,
912, 914 are not aligned along the set of vertical references 916, but instead
are staggered from one
row to the next. Keys positioned along a vertical line passing through the
center of the keyboard,
such as the "G" key in FIG. 6 may be oriented such that an axis of symmetry of
the shape coincides
with the vertical line passing through the center of the keyboard, thereby
allowing the key to be used
as easily with the left as the right thumb. In the figure, although the "G"
key was oriented with the
major axis coinciding with a vertical, it could have been placed with the
minor axis coinciding with
the vertical. In another embodiment as shown in FIG. 6a, a special center key
922 has a vertically
symmetrical key shape and orientation that is a combination of the left key
shape and the right key
shape: by superimposing the two shapes and tracing the exterior circumference
as a central shape, the
resulting shape can be used just as easily with the left or right thumb.
CA 02517815 2001-09-19
FIG. 7 is a diagram showing a third embodiment of a keyboard according to the
present
invention. This embodiment is similar to FIG. 5, except that the keys 901 in
each arced row 910,
912, 914 are circular in shape instead of ovals. Because of the circular shape
of the keys 901, the
concept of orienting the keys 901 at the first and second predetermined angles
918, 920 is not
applicable to this design. However, the concept of a circumscribed oval still
applies, as in the case of
a central key discussed above in reference to FIG. 6. It is possible to
circumscribe a thumb-impact
oval onto the keys with a major axis coinciding with a line going through the
center of each circular
key at an angle 918 and 920 for right sided keys and left sided keys
respectively. Note that the keys
901 in FIG. 7 are also aligned along the set of vertical references 916.
FIG. 8 is a diagram showing a fourth embodiment of a keyboard according to the
present
invention. This embodiment is similar to the embodiment shown in FIG. 7,
except that the keys 901
in each arced row 910, 912, 914 are not aligned along the set of vertical
references 916, but instead
are staggered from one row to the next.
FIG. 9 is a diagram showing a fifth embodiment of a keyboard according to the
present
invention. This embodiment is similar to the embodiments shown in FIGs. 5 and
7, except that the
keys are square instead of ovals or circles. The keys in FIG. 9 are also
aligned along the set of
vertical references 916.
FIG. 10 is a diagram showing a sixth embodiment of a keyboard according to the
present
invention. This embodiment is similar to the embodiment shown in FIG. 9,
except that the keys 901
in each arced row 910, 912, 914 are not aligned along the set of vertical
references 916, but instead
are staggered from one row to the next.
CA 02517815 2001-09-19
16
FIG. 11 is a diagram showing a seventh embodiment of a keyboard according to
the present
invention. This embodiment is similar to the embodiments shown in FIGS. 5, 7
and 9, except that
the keys 901 are rectangular instead of ovals, circles, or squares.
FIG. 12 is a diagram showing an eighth embodiment of a keyboard according to
the present
invention. This embodiment is similar to the embodiment shown in FIG. 11,
except that the keys
901 are not aligned along the set of vertical references 916, but are
staggered from one row to the
next.
Having described in detail the preferred embodiments of the present invention,
including the
preferred methods of operation, it is to be understood that this operation
could be carried out with
different elements and steps. This preferred embodiment is presented only by
way of example and is
not meant to limit the scope of the present invention which is defined by the
following claims.
