Data entry device having multifunction keys

A data entry device is provided, having as its primary function the entry of numeric data. A secondary function is the entry of alphabetic characters. The device is operated with a single hand and requires no shift or function keys. The number of keys of the device is kept to a minimum to avoid visual clutter and to facilitate its use with one hand. The keys are designed to be easy to access and to be operated while wearing a glove.

BACKGROUND 
1. Field of the Invention 
The present invention relates to a data entry device having keys which have 
multiple functions. In particular the present invention relates to a data 
entry device having relatively few keys, compared to an ordinary or 
standard keyboard, and in which each key can produce three, four or five 
characters depending upon how the key is depressed. The data entry device 
eliminates the need for a shift key or function key which, in a 
conventional keyboard, must be depressed simultaneously with another key 
to produce a second function, such as capitalization or a second 
character. 
2. Description of the Prior Art 
A standard keyboard has keys corresponding to the 26 letters of the 
alphabet, numbers 0-9, punctuation, and other various commonly used 
symbols. Including a shift key, a control key and an alt key, the total 
number of keys is approximately 50 Most of the keys will produce a second 
character when depressed simultaneously with the shift key. Similarly, if 
the alt key or control key are depressed with one of the other keys, 
character different from the primary character will be produced. 
While the standard keyboard is sufficient for normal use at a work station, 
it does not lend itself to use in hand-held devices, or other situations 
where a large keyboard would be awkward or inappropriate. For a hand-held 
device, a data entry device would preferably require only one hand to 
enter data. Consequently, a requirement of using a shift, control or alt 
key simultaneously with other keys would be a drawback. 
Other arrangement of keyboards exist beside the standard arrangement. For 
example, U.S. Pat. No. 4,891,777 to Lapeyre is directed to a single hand 
keyboard array which provides alphanumeric capabilities from twelve keys. 
The keyboard is intended to be operated using one hand. The system employs 
virtual keys which are selected by simultaneous action of two or more 
individual keys. The apparatus decodes the signals produced by activation 
of the switches to produce the alphanumeric symbol desired. 
U.S. Pat. 5,087,910 to Guyot-Sionnest pertains to an electronic keyboard 
for one-hand operation. The keyboard produces alphanumeric and analog 
characters upon the activation of one or more finger keys and a thumb key. 
The finger keys can each assume one of three states, and the thumb key can 
assume five different states. The keys can thereby, in combination, 
produce 134 different characters. 
Another device is described in U.S. Pat. No. 5,543,818 to Scott which 
relates to a method and apparatus for entering text using an input device 
having a small number of keys. A display device, connected to a CPU, 
displays a character selection menu having sixteen groups of characters. 
An input device which includes four cursor movement keys and four 
selection keys to choose a desired character. The four cursor movement 
keys move the cursor on the display from one character group to another. 
The four selection keys determine which of four characters in a group is 
desired. 
U.S. Pat. No. 4,680,577 to Straayer et al teaches a multipurpose cursor 
control keyswitch. The switch has an ordinary function of producing an 
alphanumeric symbol when depressed vertically, and directs cursor movement 
when horizontal pressure is applied. The Straayer et al keyswitch is not 
intended to reduce the number of keys and is not designed to facilitate 
one hand operation. 
A multiple switch assembly including a rockable control plate for 
selectively actuating multiple microswitches is disclosed in U.S. Pat. No. 
5,504,286 to Tsai. The assembly is intended to reduce the number of keys 
on the keyboard of a portable computer by employing rockable keys which 
can produce two characters without reducing the size of the keys. The keys 
can be pressed to either one of two sides corresponding to two different 
characters. The primary reason for reducing the number of keys is to 
accommodate a cursor movement device. 
U.S. Pat. No. 4,769,516 to Allen relates to a finger operated switching 
apparatus. The keyboard utilizes keys which can produce three different 
characters. The keyboard is intended to replace a conventional keyboard 
and requires two hands for use. 
U.S. Pat. No. 5,504,286 to Blauer pertains to a keyboard with elongate keys 
associated with compact switch mechanisms. The keyboard is intended to be 
used with both hands and is intended for use in a desk-top configuration. 
The keyboard has a series of keys which produce two or three outputs 
depending upon how the keys are depressed. 
SUMMARY OF THE INVENTION 
According to one aspect of the present invention, a data entry device is 
provided, having as its primary function the entry of numeric data. A 
secondary function is the entry of alphabetic characters. The device can 
be operated with a single hand and requires no shift or function keys. The 
number of keys on the device is kept to a minimum to avoid visual clutter 
and to facilitate its use with one hand. The keys are designed to be easy 
to access and to be operated while wearing a glove. The device may be 
hand-held, a telephone keypad, a television remote, or a computer 
keyboard. 
It is an object of the present invention to provide a hand-held data entry 
device. 
Another object of the present invention is to provide a data entry device 
having multifunction keys, which can produce more than one character 
depending upon how the key is depressed. 
Still another object of the present invention is to provide a data entry 
device having multifunction keys which produce three different 
alphanumeric characters. 
Yet another object of the present invention is to provide a data entry 
device having multifunction keys which produce four different alphanumeric 
characters. 
Another object of the present invention is to provide a data entry device 
having multifunction keys, which can produce five different alphanumeric 
characters. 
Still another object of the present invention is to provide a data entry 
device having multifunction keys which each have a central primary numeric 
character and secondary alphabetic characters. 
Yet another object of the present invention is to provide a data entry 
device having multifunction keys which each have a central primary numeric 
character and secondary alphabetic characters, where the numeric character 
is produced by applying a primarily vertical force to the key and the 
secondary alphabetic characters are produced by applying additional force 
in secondary directions.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to FIG. 1, a first embodiment of the data entry device 10 
according to the present invention is illustrated. The data entry device 
10 has a housing 8 and a display 12, which is preferably a liquid crystal 
display (LCD). Thirteen multifunction keys 14 are provided as are a 
backspace key (BS) 16, a space key (SP) 18, an power key 20, an enter key 
22, an .tangle-solidup. key 24, a "*" key 26 and three function keys F1, 
F2, and F3. 
The multifunction keys 14 of the first embodiment are shown in greater 
detail in FIGS. 2 and 3. The keys 14 of the first embodiment can produce 
three different characters depending upon how the keys are depressed. The 
keys 14 are oval in shape. The primary character 32 for each key 14 is 
displayed in the center of the key, while the secondary characters 34 for 
each key 14 are displayed to either side of the primary character. 
Referring to FIG. 3, the keys 14 project up through openings in a housing 
40 which forms the body of the data entry device 10. Keys 14 are disposed 
above a printed circuit board 50, and are resiliently biased away from the 
circuit board 50, by resilient arms 60. The underside of each key 14 has a 
convex profile 62, extending away from the upper side of the key 14, which 
forms an electrical actuator 64. The convex profile 62 is parallel to the 
lengthwise axis of the oval key 14. In the illustrated embodiment the 
resilient arms 60 are located on either side of convex profile 62 of the 
actuator 64. 
The circuit board 50 has a pattern of electrical contacts 100, shown in 
FIG. 6, which is repeated below each of the multifunction keys 14. The 
pattern of electrical contacts 100 consists of a series of parallel 
electrical contact lines 105 which extend perpendicular to the axis of 
curvature of the convex profile 62. Each pattern 100 has a central 
electrical contact 110 formed along line X-Y disposed in the middle of the 
pattern of electrical contacts 100. 
The .tangle-solidup. key 24 is a mode key, and determines the mode of the 
multifunction keys 14. The multifunction keys 14 are thus placed in one of 
two modes. A first mode is a primary mode or numerical mode. In the 
primary mode, the multifunction keys 14 will only produce the primary 
character 32. In the embodiment illustrated in FIG. 1, the primary 
characters are predominantly numbers "0-9", and therefore, the primary 
mode can be referred to as a numerical mode. By depressing the 
.tangle-solidup. key 24, the data entry device 10 switches from primary 
mode to multifunction mode, and vice-versa. 
In primary mode, only the primary character 32 is produced when a 
multifunction key 14 is depressed. Secondary characters 34 are disabled in 
the primary mode. In the multifunction mode, the multifunction keys 14 can 
only produce secondary characters 34. Instead of producing a primary 
character 14, the central electrical contact 110 indicates which of the 
multifunction keys is depressed, and the electrical contact lines 105 
determine which secondary character 34 is desired, as discussed below. All 
characters, primary and secondary are produced upon depression of the keys 
14, not upon their release. In primary mode, when a multifunction key 14 
is depressed so that it will produce its primary character, the user 
depresses the key 14 by applying enough force to overcome the resilient 
bias of arms 60, so that the central electrical contact 110 comes in to 
contact with the convex profile 62 of the actuator 64. As a result, the 
circuit board 50 interacts with the CPU to cause the primary character for 
that multifunction key to be registered on the LCD 12. 
If the user wants to enter one of the secondary characters on a 
multifunction key 14, the .tangle-solidup. key 24 is pressed to change to 
multifunction mode, and force is applied both vertically and 
simultaneously on an angle toward the desired secondary character on one 
side of the multifunction key 14. As a result the multifunction key 14 
moves downward toward the circuit board 50 against the bias of the 
resilient arms 60. The convex profile 62 of the actuator 64 contacts the 
central electrical contact 110 as well as simultaneously contacting the 
parallel electrical contact lines 105 on one side of the central 
electrical contact 110. The force at an angle determines which electrical 
contact lines 105 make contact with the convex profile 62 of the actuator 
64. In such a situation, depending upon the software programmed into the 
CPU, the contact between the actuator 64 and the electrical contact lines 
105 over-rides the input created by the contact between the actuator 64 
and the central contact line 110, or the contact of the actuator 64 and 
the electrical contact lines 105 and the contact between the actuator 64 
and the central contact line 110 combine so that the secondary character 
registers on the LCD 12. 
Since the actuator 64 has a convex profile 62 the electrical contact lines 
105 on either side of central contact line 110 can not make contact with 
the actuator 64 at the same time. Such a situation would create a conflict 
which the CPU could not interpret. A reverse configuration of the actuator 
and the parallel contact lines could be employed, as could other 
configurations of differing length actuators without departing from the 
scope of the present invention. 
In the first embodiment of FIGS. 1-3, the primary characters are the 
numbers "0-9", "-", and ".". Each of the thirteen multifunction keys 14 
has two letters "A-Z" as its secondary characters. No specific provision 
is made for upper case letters. The letters by default are all upper case. 
However, the three function keys F1, F2, and F3 are programmable, and in 
an application where upper and lower case characters are desired, one of 
the three function keys may be programmed to work as a shift key so that 
both upper and lower case letters may be displayed. 
While only three function keys F1, F2, and F3 are provided on the device 
10, the .tangle-solidup. key can be employed to provide three additional 
functions by .tangle-solidup. key depression followed by one of the F1, 
F2, and F3 keys. 
Referring to FIG. 4, a second embodiment of the data entry device of the 
present invention is illustrated. In this embodiment the multifunction 
keys 70 are triangular instead of oval. Each multifunction key 70 can 
produce up to four characters. The primary character is displayed in the 
center of each triangular key 70. The three secondary characters are 
displayed at the corners of the triangle. The primary characters are 
numbers "0-9", and the secondary characters are "-", and ".", and letters 
"A-Z". 
The total number of keys on the device 10 of the second embodiment is less 
than the number used in the first embodiment. The remaining keys are 
comparable to the keys of the first embodiment. The keys 70 interact with 
the circuit board 50 in the same manner as the keys 14 of the first 
embodiment. The primary character is produced when a vertical force is 
applied to the center of the key 70 causing only a central contact 120 on 
the circuit board 50. When a corner of a key 70 is depressed, both the 
central contact 120 and arcuate surrounding contact lines 225 make contact 
with the actuator 64 in the same manner as described above with regard to 
the first embodiment. Each key 70 has a convex profile which curves about 
more than one axis. The curvature of the actuator 64 may form an arcuate 
portion of a sphere. As was the case with the first embodiment, the 
curvature of the actuator prevents arcuate surrounding contact lines 225 
on different sides of the central contact 120 from making simultaneous 
contact with the actuator 64. 
The circuit board 50 has a pattern of electrical contacts 100, shown in 
FIG. 7, which is repeated below each of the multifunction keys 70. The 
pattern of electrical contacts 100 consists of a series of arcuate contact 
lines 225 which form three arcs aground the central contact 120. Each 
pattern 100 has 25 a central electrical contact 120 formed in the middle 
of the pattern of electrical contact lines 225. 
The keys 80 of a third embodiment of the data entry device of the present 
invention are shown in FIG. 5. The keys 80 are rectangular. The centers 85 
of the top of each key 80 is lower than the corners 88. The primary 
character for each key 80 is located in the center 85, while the secondary 
characters are located at the corners 88 of each multifunction key 80. 
Thus, each multifunction key 80 can produce up to five characters. The 
illustrated embodiment shows numbers "0-9", and the primary characters and 
"-", ".", "&", "+", "?", "=", "%", "$", "/", "," and letters "A-Z" as the 
secondary characters. 
The keys 80 function in a manner similar to the keys 14 and 70 of the first 
and second embodiments, respectively, discussed above. Each key 80 has a 
convex profile which curves about more than one axis. The curvature of the 
actuator 64 may form an arcuate portion of a sphere. As was the case with 
the first embodiment, the curvature of the actuator prevents contact lines 
125 on different sides of the central contact 120 from making simultaneous 
contact with the actuator 64. 
In all of the three embodiments, the multifunction keys have shapes which 
transmit unique tactile sensations to the fingers of the user thereby 
helping the user select the desired character. In the third embodiment, 
the raised corners 88 provide additional tactile sensation to the user. 
While pentagonal, hexagonal, etc., shaped keys can be employed and are 
considered to fall within the scope of the present invention, the ability 
to transmit accurate sensation to the user and thereby display the desired 
character decreases with each increase in the complexity of the keys. In 
all three embodiments characters are registered upon depression. However, 
it is contemplated that registration could occur upon release of the key 
as opposed to depression. 
The data entry device 10 of the present invention is intended to function 
as a hand-held portable unit. It would be powered by an internal power 
source such as batteries, and would be small enough to fit into a jacket 
or pants pocket. The data entry device is preferably 3" wide, 7.5" long 
and 2" thick. The weight including batteries is less than eight ounces. 
The LCD 12 is capable of displaying up to eight lines of twenty characters 
each. The device may have a built in bar code reader, such, as a laser 
scanner, CCD or bar contact reader. Such a bar code reader could be used 
to track packages or other inventory. The CPU would contain memory, 
preferably at least 1 Megabyte. 
Having described the preferred embodiments of the data entry device of the 
present invention, it is believed that other modifications, variations and 
changes will be suggested to those skilled in the art in view of the 
description set forth above. For example, the primary characters need not 
be numbers and can be letters as well as other characters. The primary 
characters may be the most commonly used letters. Furthermore, as stated 
previously, the shape of the multifunction keys can be different, such as 
pentagonal, hexagonal, octagonal, trapezoidal, or other geometric shape. 
It is therefor to be understood that all such variations, modifications 
and changes are believed to fall within the scope of the invention as 
defined in the appended claims.