Keyboard divided by central inverted T-shaped entry-space key

A keyboard comprises a plurality of regular keys, and an inverted T-shaped key subdividing the regular keys into two sections including one section for preferably left-hand operation and another section preferably for right-hand operation. A keyboard further comprises a trackball and/or two rollers requiring minimal hand movement in using them for mouse emulation.

BACKGROUND OF THE INVENTION 
The present invention relates generally to keyboards, which may be used 
with any machines for communicating, storing, processing or retrieving 
information, such as computers, typewriters, telegraphs, type composing 
machines, siphering machines, etc. 
When the typewriter became a commercial success in the 1890's after a long 
history of experiment, a variety of keyboard layouts were in use. Some 
machines used the type-bar mechanisms which later became universal for 
wholly mechanical typewriters. Because the early type-bar mechanisms were 
liable to jam if adjacent keys were struck in quick succession, the 
letters were arranged on the keyboard to avoid such sequences. The 
resulting so-called "Universal" keyboard, now generally known as QWERTY 
from its letter sequence, is inefficient in human terms, as only 50% of 
letters struck lie on the most used row, and the fingers must make many 
reaches to the other rows. A common standard keyboard layout, developed 
with the objective to exclude the type-bar jams, proved a commercial 
necessity and has become the standard for all languages written with the 
Latin alphabet. 
With the advent of electronic computers the QWERTY keyboard has been 
enlarged by the addition of a ten key numerical keypad as used on 
calculators, duplicating the ten numeric keys on the top row of the 
typewriter layout to increase the speed of numeric data entry, at least 
four cursor movement keys, and a growing number of other machine function 
keys having fixed or program assigned meanings. Leading computer 
manufacturers are now supply universal word and data processing keyboards 
having over 100 keys. 
Many investors have endeavored to improve the typewriter keyboard layout. 
The best known work is that of Dvorak et al, who described in 1932 a 
letter arrangement optimized in terms of carefully chosen criteria 
including letter frequencies and the relative strength and agility of the 
fingers. Other inventors have worked on the shape of the keyboard, 
variously proposing key rows curved to match the natural arc of the 
fingers, multiple key rows disposed in double curved bowl shapes to ease 
the reaches, thumb keys oriented nearly at right angles to the fingers 
keys to better exploit the strength and agility of the thumbs, and a 
general outward tilt of the two sides of the keyboard for the comfort of 
wrists. The gain in speed from any of these performance optimized 
keyboards appears limited, and is tentatively estimated in Siebel (1972) 
at no more than 10%. 
The speed of 40-60 words per minute expected from a competent typist 
requires so-called `touch-typing`, that is reading manuscript while 
simultaneously operating the keyboard with only tectile and audible 
feedback. To do this, the stimulus-response bonds which link letters and 
common group of letters to the finger movements, which type them, must be 
thoroughly learnt. These bonds are sequence dependent, and the reaches 
over the rows and columns make them complex. Untrained persons such as the 
journalists, authors, professionals and managers who now increasingly use 
computers without the intervention of specialists keyboard operators are 
unable to key at more than about 15 words per minute, even with much 
practical experience, because in typing the hands must "hang" over the 
keyboard to allow the finger out-stretching in the plane and direction 
which does not coincide with the natural least constrained 
contraction-extension movement of fingers. As professionals and managers 
are generally not willing to undergo formal keyboard training, the 
computer is of less benefit to them than it could be. 
The cursor movement keys of the extended QWERTY keyboard give very limited 
movement capability. A single press moves the cursor one place up, down or 
sideways, as a king moves in chess. A press and hold brings into action 
after a delay of about half a second an auto-repeat function which moves 
the cursor at a fixed, rather slow speed in the chosen direction, but 
still moving it as a rook. Moves between two arbitrary points have to be 
made as a series of zig-zags. The cursor cannot move as a queen. The fixed 
auto-repeat speed, necessarily a comprise, is time-consuming on long 
course moves and yet fast enough to lead to overshoots if the user is not 
very careful. To overcome these limitations, auxiliary devices such as the 
mouse, used to generate XY coordinates, is being adopted for cursor 
movement and for graphical work. The ease of cursor movement with these 
devices is particularly important in supporting machine languages which 
exploit to the full the human preference for communicating by showing 
rather than telling. These auxiliary devices have however the disadvantage 
in textual work that one hand must be moved frequently between the 
keyboard and the mouse, which is disorienting and time-consuming. 
A further disadvantage of the conventional keyboard is the high risk of 
accidentally initiating computer action by pressing the `Enter` key before 
one means to, due to its placement at the front of the keyboard next to 
the right shift key. The occasional proposals in the data processing art 
for thumb keys, operating in a plane differing from that of the other 
finger keys, are related to the unused strength and agility of thumbs 
which belong to the strongest fingers which are least active over the 
keyboard. 
SUMMARY OF THE INVENTION 
Accordingly, it is an object of the present invention to provide a keyboard 
which eliminates the disadvantages of the prior art. 
More particularly, it is an object of the present invention to provide a 
keyboard which is ergonomically designed to take maximum advantage of the 
shape, dexterity, and strength of the hands and fingers so that the 
majority of the fingers on both hands are always positioned on the home 
keys, requiring less efforts in outreaching to the other keys. 
In keeping with these objects and with others which will become apparent 
hereinafter, one feature of the present invention resides, briefly stated, 
in a keyboard which has a plurality of regular keys forming substantially 
two rectangular fields, subdivided by an inverted T-shaped key into two 
sections: one for preferably left-hand operation, and another for 
preferably right-hand operation. 
The main benefit of the keyboards subdivided by the inverted T-shaped key 
into two section is that it facilitates touch-typing with hands 
essentially fixed on a desk. 
In accordance with another feature of the present invention: rows of keys 
are located on a tilted flat plane or on a concave cylindrical surface. 
The axis of curvature of the cylindrical surface intersects a vertical 
central line of the inverted T-shaped key at 75.degree.-90.degree. angle 
from the left and from the right, respectively. 
Still another feature of the present invention is that the columns of the 
keys are arranged in parallel grooves, which are located on the flat 
tilted surface or on the concave cylindrical surface. 
In accordance with a further feature of the present invention a trackball 
is located at the keyboard top part, on a vertical central line of the 
inverted T-shaped key. 
An additional feature of the present invention is that each key is provided 
with a depression which can have a truncated-cone shape, and a key top 
with a matching truncated-cone snap insert can be attached to the key by 
inserting the snap insert into the depression. 
The novel features which are considered as characteristic for the invention 
are set forth in particular in the appended claims. The invention itself, 
however, both as to its construction and its method of operation, together 
additional objects and advantages thereof, will be best understood from 
the following description of specific embodiments when read in connection 
with the accompanying drawings.

DESCRIPTION OF A PREFERRED EMBODIMENT 
A keyboard in accordance with the present invention has a plurality of 
regular keys identified with reference numeral 1 and is subdivided into 
two sections by an inverted T-shaped key 2: one section for preferably 
left-hand operation and the other for preferably right-hand operation as 
shown in FIG. 1. The upper part of the inverted T-shaped key can be used 
for `Enter` function and the lower part of the same can be used for 
`Space` function. 
Both sections of the inventive keyboard include four parallel key-rows 
comprising in the left-hand section six parallel key-columns, and in the 
right-hand section comprising eight parallel key-columns. As can be seen 
from FIG. 2 the key rows in the left-hand and in the right-hand sections, 
respectively, are located on a concave cylindrical surface with a radius 
of curvature of at least 6 cm and a cylindrical axis parallel to the 
key-row. The curvature radius of 6 cm is determined by the average 
distance between finger tips and knuckles of keyboard user's hands with 
the fingers curved in a moderate arc and the wrists straight. To save the 
depth of a keyboard, as it is required for a miniature keyboards of 
portable and pocket computers, the curvature radius can be increased to 
infinity thus forming a flat surface for allocation of keys. The axes of 
rotation of the cylindrical surfaces of the preferentially left-hand and 
right-hand sections intersect the vertical central line of the inverted 
T-shaped key at the angle of 75.degree.-90.degree. from the left and from 
the right, respectively. 
As can be seen from FIG. 3 the key-columns are arranged in parallel lines. 
The keys or more particularly the key caps have cylindrical top 
depressions, and the keys are arranged in parallel grooves located on the 
concave surface mentioned hereabove. 
The upper part of the central key performing `Enter` function is located 
between the preferentially left-hand and right-hand sections. The lower 
part of the central key performing `Space` function, partly extends to the 
area below the left-hand and the right-hand sections. 
As shown in FIG. 1 a trackball 3 is placed at the keyboard top part, at the 
vertical central line of the T-shaped key, and two rollers 4 and 5 are 
positioned to the left and to the right of the trackball and have axes of 
rotation extending parallel to the vertical line of the inverted T-shaped 
key. The trackball and the rollers together constitute a device to be used 
for the cursor free movement. The trackball and/or the rollers are used 
for mouse emulation. They facilitate the usage of mouse-based software on 
all computers, laptops, and pocket computers since they require the 
minimum shift of hands from the home position. 
Preferably, the trackball allows the cursor movement to be performed by the 
left or by the right forefinger. The left and right rollers control the 
cursor movement along the horizontal X--X line and along the vertical Y--Y 
line, respectively. Concurrent action of both rollers ensure all the 
movements necessary for a mouse emulation. The cursor movement velocity is 
controlled by a differential amplifier: the faster you roll it the faster 
it moves across the screen, while at slow rotation it moves slowly 
ensuring high accuracy in cursor positioning. The two keys placed next to 
the left and right rollers, respectively, could be pressed down performing 
in this manner the push-button function of the conventional two-button 
mouse. 
The central T-shaped key is designed to be operated by the left or by the 
right forefinger. The `Space` part of it provides additionally the choice 
to be actuated by the left or by the right thumb or by the left or the 
right forefinger. 
Preferably, the keyboard includes 12 function keys, arranged on the left 
side and 12 function keys arranged on the top of the keyboard, thus 
combining both commercial layouts in one keyboard. This feature 
facilitates the development of software using 24 function keys. 
The arrangement of the four key-rows in the left-hand and right-hand 
sections on the concave cylindrical surfaces with the above mentioned 
curvature radius and with the cylinder axis parallel to the key rows and 
intersecting the vertical central line of the inverted T-shaped key from 
the left and from the right, respectively, accommodates best the natural 
curve of the hands at rest with the fingers in a moderate arc and the 
wrists straight. Key caps shown in FIGS. 4a and 4b have top cylindrical 
depressions such that the depressions in a key column form a continuous 
groove with the central line, preferably perpendicular to the key rows as 
shown in FIG. 3. A truncated-cone hole 7 is provided in the center of each 
key cap and helps to center fingers and develop their motor reaction in 
touch-typing training. After completion of the touch-typing course, and 
acquiring sufficient proficiency in typing, the truncated-cone hole 7 is 
used for inserting a thin plastic key-top 8 with a matching truncated-cone 
snap insert 9 as shown in FIGS. 4a and 4b. The plastic key-tops may be 
used for customizing each keyboard and selecting the layout of the keys 
most suitable for the customer. For example, on all commercial keyboards 
the key row of numbers and symbols is located at the top. The plastic 
key-tops and the macro function, built into the keyboard, allow a user to 
place the key row of numbers and symbols at the bottom line of the 
left-hand and right-hand sections of the keyboard, out of reach of the key 
pool that is used more than 90% of the total touch-typing time. 
The proposed keyboard preserves the high ergonomic potential when used for 
miniaturized keyboards for laptop and pocket computers as shown in FIG. 5. 
The rollers for cursor free movement on a miniature keyboard are located 
to the left and to the right of `Space` key. The rollers may be actuated 
by left and right thumbs, respectively, without substantial movement of 
the hands from the home position. The two additional keys located at the 
left and right ends of the `Space` key serve for the actuation of 
roller-mouse-emulation functions. The concurrent action of the two rollers 
enables to use them for mouse emulation on the laptops and pocket 
computers. 
It will be understood that each of the elements described above, or two or 
more together, may also find a useful application in other types of 
constructions differing from the types described above. 
While the invention has been illustrated and described as embodied in a 
keyboard, it is not intended to be limited to the details shown, since 
various modifications and structural changes may be made without departing 
in any way from the spirit of the present invention. 
Without further analysis, the foregoing will so fully reveal the gist of 
the present invention that others can, by applying current knowledge, 
readily adapt it for various applications without omitting features that, 
from the standpoint of prior art, fairly constitute essential 
characteristics of the generic or specific aspects of this invention. 
What is claimed as new and desired to be protected by Letters Patent is set 
forth in the appended claims.