U.S. patent application number 10/126534 was filed with the patent office on 2002-08-15 for cluster key arrangement.
Invention is credited to Krishnan, Ravi C..
Application Number | 20020110237 10/126534 |
Document ID | / |
Family ID | 23143658 |
Filed Date | 2002-08-15 |
United States Patent
Application |
20020110237 |
Kind Code |
A1 |
Krishnan, Ravi C. |
August 15, 2002 |
Cluster key arrangement
Abstract
A cluster key arrangement may be mechanically configured or
electronically configured. The cluster key arrangement may include
twelve cluster keys configured in an arrangement of three columns
by four rows, such as conventionally found on standard telephones.
The cluster key arrangement may also be configured for use or
cellular/mobile telephones, television remote controls, other
handheld data entry devices, automotive controls,
desktop/wall-mounted/cordless telephones, combination telephone
recorders, Personal Digital Assistants, and other electronic
devices. The mechanically or electronically configured cluster,
keys provide a user with the ability to select one of a plurality
of key elements representing numbers, letters, symbols, functions,
etc., in a mutually exclusive manner.
Inventors: |
Krishnan, Ravi C.;
(Bethesda, MD) |
Correspondence
Address: |
Richard C. Litman
P.O. Box 15035
Crystal City Station
Arlington
VA
22215-0035
US
|
Family ID: |
23143658 |
Appl. No.: |
10/126534 |
Filed: |
April 22, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10126534 |
Apr 22, 2002 |
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09296809 |
Apr 23, 1999 |
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6377685 |
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Current U.S.
Class: |
379/419 ;
379/433.07 |
Current CPC
Class: |
H01H 2221/012 20130101;
H01H 2225/022 20130101; H01H 2239/052 20130101; G06F 3/0202
20130101; H01H 2217/012 20130101; H04M 1/23 20130101; H01H 13/785
20130101; H01H 2239/006 20130101; H01H 2201/036 20130101; H01H
13/807 20130101; H01H 2217/036 20130101; H01H 13/705 20130101; H01H
2219/012 20130101; G06F 3/0234 20130101; H01H 2239/022 20130101;
H01H 2217/004 20130101 |
Class at
Publication: |
379/419 ;
379/433.07 |
International
Class: |
H04M 001/00; H04M
009/00 |
Claims
I claim:
1. A cluster key arrangement comprising: a cluster key means
including a primary key means and at least one secondary key means;
and, switching means enabling a user to select said primary key
means or said at least one secondary key means in a mutually
exclusive manner.
2. A cluster key arrangement according to claim 1, wherein said
cluster key arrangement is mechanically configured.
3. A cluster key arrangement according to claim 2, wherein said
primary key means and said at least one secondary key means are
constructed from material having a large range of hardness to
provide positive tactile feedback to a user.
4. A cluster key arrangement according to claim 2, wherein said
primary key means includes a dome shaped or convex button
profile.
5. A cluster key arrangement according to claim 2, wherein said
primary key means includes a trough or concave profile.
6. A cluster key arrangement according to claim 2, wherein said
primary key means is labelled with a number, an asterisk symbol, or
a pound sign.
7. A cluster key arrangement according to claim 2, wherein said
primary key means has a top view which is shaped circularly,
ellipsoidally, pentagonally, hexagonally, heptagonally, or
octagonally.
8. A cluster key arrangement according to claim 2, further
comprising twelve cluster key means configured in an arrangement of
three columns by four rows.
9. A cluster key arrangement according to claim 2, wherein said at
least one secondary key means has a rectangular, trapezoidal, or
semi-circular shape with a concave arcuate profile.
10. A cluster key arrangement according to claim 2, wherein said at
least one secondary key means is labelled with a function
designation, a letter, or a character symbol.
11. A cluster key arrangement according to claim 2, in combination
with a remote telephone comprising a housing, a speaker, a
microphone, and an antenna.
12. A combination according to claim 11, wherein said housing
includes a liquid crystal display.
13. A cluster key arrangement according to claim 1, wherein said
cluster key arrangement is electronically configured.
14. A cluster key arrangement according to claim 13, further
comprising an integrated pressure sensing element.
15. A cluster key arrangement according to claim 13 further,
comprising a p-i-n junction amorphous silicon solar cell with two
conductive transparent coatings.
16. A cluster key arrangement according to claim 13, further
comprising a conductive grid.
17. A cluster key arrangement according to claim 13, wherein said
cluster key arrangement is electronically configured in the, form
of a touch screen liquid crystal display.
18. A combination according to claim 17, wherein said primary key
means have a circular, ellipsoidal, pentagonal, hexagonal,
heptagonal, or octagonal image and said at least one secondary key
means have a rectangular, trapezoidal, or semi-circular image.
19. A combination according to claim 17, wherein said liquid
crystal display is further mildly textured to facilitate tactile
feedback.
20. A combination according to claim 17, wherein said touch screen
liquid crystal display includes an upper glass sheet, a lower glass
sheet, and a thin layer of liquid crystal material sandwiched
between the upper glass sheet and the lower glass sheet.
21. A cluster key arrangement according to claim 17, wherein said
touch screen liquid crystal display is an active matrix thin film
transistor display.
22. A cluster key arrangement according to claim 17, in combination
with a palmtop computer based personal digital assistant having a
color touch screen liquid crystal display with built-in functions
of a cellular telephone resulting in a combination personal digital
assistant and cellular telephone that has a display area which
provides for a long talk/useage time per battery charge.
23. A combination according to claim 22, further comprising a
mechanical cluster key configuration.
24. A cluster key arrangement according to claim 17, in combination
with a remote telephone comprising a housing, a speaker, a
microphone, and an antenna.
25. A combination according to claim 24, wherein said housing
includes a power switch and a mode switch.
26. A combination according to claim 24, wherein said touch screen
liquid crystal display further comprises an active matrix thin film
transistor display
27. A combination according to claim 26, further comprising a layer
of i-type semiconductor disposed between a layer of p-type
semiconductor and a layer of n-type semiconductor.
28. A combination according to claim 27, further comprising two
conductive transparent coatings of tin oxide or indium tin oxide to
provide two layers, wherein said layers are capable of being
combined in series to provide a trickle charge.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a cluster key arrangement
which provides a user with the ability to select one of a plurality
of key elements representing numbers, letters, symbols, functions,
etc., in a mutually exclusive manner.
[0003] 2. Description of the Related Art
[0004] The touch-tone dial system has become the standard dialing
system for conventional telephones, largely replacing the older
rotary dial. The standard touch-tone dials have push-buttons
arranged in a rectangular matrix pattern. Each button activates a
switch to energize a tone generator of unique frequency. In
addition, the push-buttons are arranged to activate a common switch
for disconnecting the transmitter while a tone generator is
operating.
[0005] Use of a telephone keypad with a telephone keypad matrix as
a data terminal for the input of alphanumeric characters into a
computer system, using or via a telephone line which further in
turn forwards the message from the terminal to a service provider
computer, such as a paging system, facsimile device, e-mail and/or
voice mail system, or Personal Digital Assistants (PDAs) which have
the ability to store schedules, memos, etc., and further have the
ability to upload and download information from a base computer
which are operated on an on-board battery with an operating life of
many days for a monochrome display, and an operating life of on the
order of six hours for displays with color capability which are
increasingly desirable for clarity and user friendliness, and
cellular phones with desirable code division multiple access (CDMA)
technology which provides for better voice quality and security
having only about two to three hours of CDMA talk time are some of
the trends in this area.
[0006] The most obvious form of elementary clustering is noticed in
the standard 102 or 104 key personal computer keyboards in the
grouping of the directional arrows. Other than copying this ideal
on some cellular telephone models, this has not resulted in any
clustering of other keys either in patents or in commercially
available products. Thus, what is being proposed here is not al
mere extension of the preceding, which would be obvious to those
skilled in the art. Rather, what is being proposed here derives
from an identification of the deficiencies of the prior art and an
invention that overcomes those deficiencies.
[0007] It is worthwhile to review contradictions between standards
that have come about due to their divergent origins but nonetheless
find themselves in a convergent path due to emergence of technology
driven changes. The most obvious example is the "789" arrangement
of the calculator industry and the "123" arrangement of the
pushbutton telephone. The horizontal "1234567890" derived from the
"QWERTY" typewriter keyboard forms the backbone of computer data
entry with the "789" calculator still present on the right handy
side as a rarely used vestigial organ. Most of the numerical
entries are done on the QWERTY side. Other non-QWERTY approaches,
although better in concept have not really taken off. The preceding
is mentioned also to reinforce that certain consumer "corporate
memory" driven preferences will prevail as in QWERTY and in other
cases the "123" of the telephone has clearly become more dominant
instead of the "789" of the calculator. However, the same, "123"'s
additional alphabet assignments, upon "force fitting" them for
additional uses such as for paging and e-mails have not been user
friendly.
[0008] Most cell phones serve the purpose of audio(voice)
interaction and are often used in unsafe but widely prevalent
"while driving in an automobile mode". Typically numbers are
punched in or a received call is answered by pressing a button most
often with the thumb. Thus, user friendliness based on ergonomic
features is al must. Thus, making the individual number buttons as
large as possible is a must. In reality all products in the market
have seen a trend toward miniaturization of the keycap size, driven
by factors such as: (1) relentless downsizing in width (Ericsson
KH668 is 13/4" for example contrasted with Nokia 2190 at 21/4" and
Casio's CP-850 cordless telephone is 21/4"). Product sleekness can
still be achieved by better utilization of the space available; (2)
"Real Estate" requirements for the liquid crystal display and the
control keys have made the keypad size shrink further in the top
vertical direction, typically being 11/2" for the primary keys (1,
2, 3, 4, 5, 6, 7, 8, 9, 0, *, and #). In most cell phones, the
control keys comprising ON/OFF and NO/END are in one button (in
Ericsson KH668), the SEND or YES (to answer an incoming call) is a
second button, a CLEAR button along with two forward and backward
arrows make up five keys. An additional switch may be located on
the side surface. Conceptually, the prior art deficiency stems from
on the one hand mindless and unimaginative miniaturization of the
human interface in attempting to keep up with electronic
miniaturization and assuming wrongly that all the control keys need
to be associated with the display and consequently are better
positioned at the top in one separate row which happens to take up
the most space. In actuality, the two largest keys (ON/OFF and
NO/END) and (SEND/YES) have more functional association with the
primary function of the telephone without a display. The minimal
set of keys for the display are three, i.e. CLEAR, and two arrow
keys. The related art is represented by the following patents of
interest.
[0009] U.S. Design Pat. No. 397,694, issued on Sep. 1, 1998 to
Nicholas Mischenko et al., shows an ornamental design for a
faceplate having a keypad cover for a portable telephone. Mischenko
et al. do not suggest a cluster key arrangement according to the
claimed invention.
[0010] U.S. Pat. No. 4,370,528, issued on Jan. 25, 1983 to a Louis
F. Aschenbach, describes a miniature sealed toggle switch.
Aschenbach does not suggest a cluster key arrangement according to
the claimed invention.
[0011] U.S. Pat. No. 4,418,247, issued on Nov. 29, 1983 to Kaj B.
Hansen, describes an electrodynamic transducer which has an
additionally improved sensitivity and can be produced almost
completely automatically. Hansen does not suggest a cluster key
arrangement according to the claimed invention.
[0012] U.S. Pat. No. 4,439,647, issued on Mar. 27, 1984 to Nick
Calandrello, describes a capacitive keyboard which uses a standard
printed circuit board provided in various locations with spaced
conductor pairs. Calandrello does not suggest a cluster key
arrangement according to the claimed invention.
[0013] U.S. Pat. No. 4,680,577, issued on Jul. 14, 1987 to David H.
Straayer et al., describes a multipurpose keyswitch for controlling
cursor movement on a CRT display and for character entry. Straayer
et al. do not suggest a cluster key arrangement according to the
claimed invention.
[0014] U.S. Pat. No. 4,687,200, issued on Aug. 18, 1987 to Ichiro
Shirai, describes a multi-directional switch in which on-off
operation of multiple contacts is dependent on the pressing
directions of the switch. Shirai does not suggest a cluster key
arrangement according to the claimed invention.
[0015] U.S. Pat. No. 4,891,777, issued on Jan. 2, 1990 to James M.
Lapeyre, describes a keyboard for use by one hand and adapted for
entry of a large number of selections including those for
alphanumeric data processing and a large range of computer
operation commands. Lapeyre does not suggest a cluster key
arrangement according to the claimed invention.
[0016] U.S. Pat. No. 4,918,264, issued on Apr. 17, 1990 to Masato
Yamamoto et al., describes a switching device capable of returning
to the neutral position of the operating member or centering itself
by the resilience of a rubber switch. Yamamoto et al. do not
suggest a cluster key arrangement according to the claimed
invention.
[0017] U.S. Pat. No. 5,057,657, issued on Oct. 15, 1991 to Vedran
Skulic, describes a low profile keyboard switch, having tactile
and/or audible attributes for use in combination with a digitally
operable, membrane switch array. Skulic does not suggest a cluster
key arrangement according to the claimed invention.
[0018] U.S. Pat. No. 5,227,594, issued on Jul. 13, 1993 to Louis G.
Russo, describes an electrical switch assembly. Russo does not
suggest a cluster key arrangement according to the claimed
invention.
[0019] U.S. Pat. No. 5,253,940, issued on Oct. 19, 1993 to Max
Abecassis, describes a method to arrive at a single standard for
numeric keypad layouts that provides consumers the means to set for
themselves a single numeric keypad standard, and in this manner
lead to the abandonment of layouts inconsistent with the layout
incorporated on telephone devices. Abecassis does not suggest a
cluster key arrangement according to the claimed invention.
[0020] U.S. Pat. No. 5,339,358, issued on Aug. 16, 1994 to Adel
Danish et al., describes a data terminal enabling a user to easily
input alphabetical, as well as numerical characters, into a
telephone for input to a computer which in turn accesses a service
provider computer. Danish et al. do not suggest a cluster key
arrangement according to the claimed invention.
[0021] U.S. Pat. No. 5,378,862, issued on Jan. 3, 1995 to Hideo
Tasaka et al., describes a switch which provides different
switching inputs by pushing different operating portions of a
single operating button. Tasaka et al. do not suggest a cluster key
arrangement according to the claimed invention.
[0022] U.S. Pat. No. 5,386,091, issued on Jan. 31, 1995 to Kevin F.
Clancy, describes a low profile keyswitch for use with a computer
keyboard, calculator and other electronic machines that process
data and information. Clancy does not suggest a cluster key
arrangement according to the claimed invention.
[0023] U.S. Pat. No. 5,396,030, issued on Mar. 7, 1995 to Hiroshi
Matsumiya et al., describes a control-key mechanism. Matsumiya et
al. do not suggest a cluster key arrangement according to the
claimed invention.
[0024] U.S. Pat. No. 5,430,262, issued on Jul. 4, 1995 to Hiroshi
Matsui et al., describes a combination push switch device
comprising a single push button with at least two push members
which can independently operate at least two switch elements.
Matsui et al. do not suggest a cluster key arrangement according t
the claimed invention.
[0025] U.S. Pat. No. 5,612,690, issued on Mar. 18, 1997 to David
Levy, describes a compact keypad system in which each function may
be actuated comfortably by an adult-sized human finger. The key pad
electronics are designed to register simultaneously actuated
keycaps at an interstice as an input uniquely associated with the
symbol located at the interstice. This distinguishes over the
present invention because in the present invention a single
character is generated in a mutually exclusive manner depending
upon which specific key of a cluster key is depressed. Levy does
not suggest a cluster key arrangement according to the claimed
invention.
[0026] U.S. Pat. No. 5,631,453, issued on May 20, 1997 to Takuya
Maeda, describes a multi-way flipping switch in which a movable
contact can be reliably brought into contact with a stationary
contact to thereby attain a stable contact state, and is capable of
preventing two or more pairs of switching elements from being
simultaneously turned on while securing the requisites
waterproofness for the contact section. Maeda does not suggest a
cluster key arrangement according to the claimed invention.
[0027] U.S. Pat. No. 5,666,113, issued on Sep. 9, 1997 to James D.
Logan, describes a system which automatically switches use of a
touch sensitive computer input touchpad between the functions of
cursor control and keypad emulation. Logan does not suggest a
cluster key arrangement according to the claimed invention.
[0028] U.S. Pat. No. 5,758,295, issued on May 26, 1998 to Bjorn
Ahlberg et al., describes a single mode mobile cellular telephone
with a man-machine interface which is the same for all cellular
telephone systems. Ahlberg et al. do not suggest a cluster key
arrangement according to the claimed invention.
[0029] U.S. Pat. No. 5,818,437, issued on Oct. 6, 1998 to Dale L.
Grover et al., describes a highly efficient reduced keyboard which
is used in conjunction with a display. The keyboard has twelve
keys, nine of them labeled with numerous letters and other symbols,
and those nine plus one more are labeled with one of the ten
digits. Textural entry keystrokes are ambiguous. The user strikes a
delimiting "select" key at the end of each wordy delimiting a
keystroke sequence which could match any of many words with the
same number of letters. The keystroke sequence is processed with a
complete dictionary, and words which match the sequence of
keystrokes are presented to the user in order of decreasing
frequency of use. The user selects the desired word. The letters
are assigned to the keys in a non-sequential order which reduces
chances of ambiguities. The present invention generates a single
character in a mutually exclusive manner depending upon which
specific key of a cluster key is depressed. Grover et al. do not
suggest a cluster key arrangement according to the claimed
invention.
[0030] U.S. Pat. No. 5,841,374, issued on Nov. 24, 1998 to Joseph
N. Abraham, describes a compact, pocket computer for word
processing utilizing keys which combine a plurality of toggle
switches or multidirectional keys in a pocket size case. Abraham
does not suggest a cluster key arrangement according to the claimed
invention.
[0031] U.S. Pat. No. 5,844,506, issued on Dec. 1, 1998 to Ronald P.
Binstead, describes a touchpad comprising an electrically
insulating membrane with a first series of spaced apart conductors
on a first face of the membrane and a second series of spaced apart
conductors on or proximal thereto, in which there is no electrical
contact between the first and second series of conductors. Binstead
does not suggest a cluster key arrangement according to the claimed
invention.
[0032] U.S. Pat. No. 5,852,414, issued on Dec. 22, 1998 to Seymour
H. Yu et al., describes a triangle-shaped 4-way-switching key for a
keypad consisting of 10 keys alternating upwards and downwards
pointing positioned for entering alphanumeric data into a computer
or communication device. Yu et al. does not suggest a cluster key
arrangement according to the claimed invention.
[0033] U.S. Pat. No. 5,861,823, issued on Jan. 19, 1999 to Gary J.
Strauch et al., describes a data entry device having multifunction
keys, which can produce more than one character depending upon how
the key is depressed. Separation of the intended function of
depressing the central primary key is achieved in all three
embodiments through a second function key which puts the device in
a primary function or a multifunction mode. Strauch et al. requires
the generation of at least two characters, a primary character and
at least one secondary character, upon depression of any key. This
distinguishes over the present invention because in the present
invention a single character is generated in a mutually exclusive
manner depending upon which specific key of a cluster key is
depressed. Strauch et al. does not suggest a cluster key
arrangement according to the claimed invention.
[0034] Germany Patent document 3,234,417 A1, published on Mar. 22,
1984, describes a keyboard for generating an alphanumerical symbol.
Germany '417 does not suggest a cluster key arrangement according
to the claimed invention.
[0035] Germany Patent document 3,532,201 A1, published on Mar. 19,
1987, describes an electronic keyboard. Germany '201 does not
suggest a cluster key arrangement according to the claimed
invention.
[0036] Great Britain Patent document 1,035,193, published on Jul.
6, 1966, describes an electric switch which includes fixed contacts
and a moving bridging contact in the form of a surface of
revolution carried by a support on which it is free to turn about
its axis and with which it can be moved generally in a radial,
direction at right angles to the line joining the fixed contacts to
engage them. Great Britain '193 does not suggest a cluster key
arrangement according to the claimed invention.
[0037] Great Britain Patent document 1,313,754, published on Apr.
18, 1973, describes a joystick controlled switch apparatus
comprising an operating lever rotatable about a pivot point in a
support intermediate first and second portions of the lever. Great
Britain '754 does not suggest a cluster key arrangement according
to the claimed invention.
[0038] Japan Patent document 1-93249, published on Apr. 12, 1989,
describes a character information input device. Japan '249 does not
suggest a cluster key arrangement according to the claimed
invention.
[0039] An article entitled "THE ABCS OF KEYPAD LOGIC", by Mike
Mills, published Feb. 15, 1999 in the Washington Post, describes a
keypad operating in conjunction with software to disambiguate
keystrokes entered by a user to make a highly educated guess of
what the user is trying to spell. The keyboard has twelve keys,
nine of them labeled with numerous letters and other symbols, and
those nine plus one more are labeled with one of the ten digits.
Textural entry keystrokes are ambiguous. The user strikes a
delimiting "select" key at the end of each word, delimiting a
keystroke sequence which could match any of many words with the
same number of letters. The keystroke sequence is processed with a
complete dictionary, and words which match the sequence of
keystrokes are presented to the user in order of decreasing
frequency of use. The use selects the desired word. The letters are
assigned to the keys in a non-sequential order which reduces
chances of ambiguities. The present invention generates a single
character in a mutually exclusive manner depending upon which
specific key of a cluster key is depressed. This article does not
suggest a cluster key arrangement according to the claimed
invention.
[0040] An article entitled "INVENTOR ON THE VERGE OF A NERVOUS
BREAKTHROUGH", by David Stipp, published Mar. 29, 1999 in Fortune
Magazine, pages 106-116, describes a palm-sized keyboard with
full-sized keys. This article does not suggest a cluster key
arrangement according to the claimed invention.
[0041] An article entitled "SEMI-CAPTIVE KEYBOARD", published in
February, 1976 in Xerox Disclosure Journal Vol. 1 Number 2, page
85, describes a keyboard for information encoding with minimal
finger movement by the operator. This article does not suggest a
cluster key arrangement according to the claimed invention.
[0042] An article entitled "COMPACT COMPUTER KEYBOARD", published
in March, 1985 in IBM Technical Disclosure Bulletin, Vol. 27 No.
10A, pages 5640-5642, describes a small computer keyboard that
retains the conventional spatial relationships among the alphabetic
keys without reducing the standard surface area for finger contact
on each key or the spacing between adjacent keys. This article does
not suggest a cluster key arrangement according to the claimed
invention.
[0043] An article entitled "SMART KEY", published in October, 1985
in IBM Technical Disclosure Bulletin Vol. 28 No. 5, pages
1859-1860, describes a special key positioned on the keyboard
portion of an interactive terminal for controlling cursor
positioning at the terminal display by touch control. This article
does not suggest a cluster key arrangement according to the claimed
invention.
[0044] An article entitled "SPACE BAR THAT ROLLS", published in
August, 1989 in. IBM Technical Disclosure Bulletin Vol. 32 No. 3B,
pages 700-701, describes a space bar which can rotate along its
long axis in order to provide an additional function. This article
does not suggest a cluster key arrangement according to the claimed
invention.
[0045] None of the above inventions and patents, taken either
singularly or in combination, is seen to describe the instant
invention as claimed.
SUMMARY OF THE INVENTION
[0046] The present invention is a cluster key arrangement. The
cluster key arrangement may be mechanically configured or
electronically configured. The cluster key arrangement may include
twelve cluster keys configured in an arrangement of three columns
by four rows, such as conventionally found on standard telephones.
The cluster key arrangement may also be configured for use on
cellular/mobile telephones, television remote controls, other
handheld data entry devices, automotive controls,
desktop/wall-mounted/cordless telephones, combination telephone
recorders, Personal Digital Assistants (PDAs), and other electronic
devices. The cluster keys provide a user with the ability to select
one of a plurality of key elements representing numbers, letters,
symbols, functions, etc., in a mutually exclusive manner.
[0047] The mechanical cluster keys each include a primary key and
at least one secondary key. The number of secondary keys is
preferably in the range of four to eight. The mechanical cluster
keys are preferably constructed from material giving a large range
of hardness that may be needed to provide positive tactile feedback
to the user. The primary key preferably includes a dome or convex
shaped button profile further shaped circularly, ellipsoidally
pentagonally, etc., as viewed from the top. The dome or convex
shaped primary key profile as it reaches the vicinity of the
secondary key assumes a concave profile. While a concave profile
may be substituted for a dome, other button shapes, as viewed from
the top, such as hexagonal, heptagonal, or octagonal may be
substituted. The secondary keys preferably each have a concave
profile starting at the perimeter of the primary key somewhat
underneath the primary key in elevation and rise up in a concave
arcuate profile to increase the contact surface area of the
fingertip for better pressure distribution and ends with a greater
width such as obtained by the wide end of a trapezoid, for
providing a greater width to the finger to act on, and ends at an
elevation which is slightly lower than the top elevation of the
dome of the primary key, with which it is clustered. Other
secondary key profiles, as viewed from the top, may include shapes
such as rectangular, trapezoidal, semi-circular, or elongated to
provide more finger contact.
[0048] The primary keys are each labelled with a number, an
asterisk symbol (*), or a pound sign (#). The secondary keys are
each labelled with a function designation, letters, or character
symbols. Each key has a first portion of the key exposed on a first
side of the key cluster, and a second portion and third portion of
the key exposed on a second side of the key cluster. When the first
portion of a key is depressed by a user, the second portion of the
primary key comes into contact with the second portions of the
secondary keys with which it is clustered an mechanically mutually
excludes any of the corresponding secondary keys' third portions of
that particular key cluster from contacting a substrate such as a
printed circuit board or an intermediate layer of an elastomeric
sheet that has hat like protrusions with attached conductive
elements under the hats to complete a circuit upon being depressed.
If the primary key is depressed, none of the associated secondary
keys may contact the substrate. If a secondary key is depressed
preferably neither the associated primary key nor the remaining
secondary keys may contact the substrate. It is possible that if a
secondary key is depressed, at least two of the immediately
adjacent secondary keys will be precluded from acting on the
substrate.
[0049] One technique for detecting a depressed condition of a key
utilizes a capacitive key wherein a key circuit element forms two
spaced apart metallic areas and has a plated pad formed from a
metal such as tin, nickel, or copper such that when the key end is
brought in close proximity to the current element, a capacitive
charge is noted by a keypad circuit board and a key-depressed state
is acknowledged by a corresponding keyboard microprocessor and
logic unit. An alternative construction incorporates a hardcontact
keyboard, wherein the key has a stem which directly engages with
the concave cavity, in close proximity with a pair of contacts
comprising the circuit element which are then brought into
electrically communicative relationship therebetween. Such a
configuration for use in association would include physical shell
caps on a flexible board spaced from a circuit board which includes
metallic contacts. The shell caps each include a metallic element
within the cap. When a user presses one button of a selected
cluster key, a signal is generated when the key bottom of the key
presses a shell cap and causes the associated metallic element to
contact a metallic contact.
[0050] A mechanical cluster key arrangement configured for use on a
remote telephone includes a housing, a speaker, and a microphone.
The housing also includes a liquid crystal display. Openings in the
housing are provided for the individual cluster keys. In addition,
the remote telephone may also include a buzzer, indicator lights,
and other features, depending upon a particular design or model.
The remote telephone includes a main printed circuit board which
includes all of the major radio frequency (RF) and logic circuits
required to provide at least basic cellular telephone service and
support a variety of features. Such circuits typically include a
plurality of chips, integrated circuits, and other components
interconnected formed within, or on the surface, of the printed
circuit board. The remote telephone also includes an antenna that
extends through an aperture provided in the housing and is
electrically connected to the printed circuit board.
[0051] The housing encloses a substrate on which are mounted the
closing switches and the dial pulse circuit which is controlled by
these switches. Upon reception of RF signals, the mobile telephone
receives the RF signals through the antenna. The antenna converts
the received RF signals into electrical RF signals for use by the
radio circuitry. The radio circuitry demodulates the electrical RF
signals and recovers the data transmitted using the RF signals.
Additionally, the radio circuitry outputs the data to a processor.
The processor includes at least a main processor and associated
memory as well as other control circuits including integrated
circuits or other known technologies. The processor formats the
data output from the radio circuitry into a recognizable voice or
message information for use by the user interface. The user
interface communicates the received information or voice to a user
through the use of the speaker and the display. All digital or all
analog or combinations of analog and digital network based cellular
telephone services are possible.
[0052] Unlike present analog systems and other digital systems that
divide the available spectrum into narrow channels and assign one
or more conversations to each channel, CDMA is a wideband spread
spectrum technology that spreads multiple conversations across a
wide segment of the broadcast spectrum. Each telephone or data call
is assigned a unique code that distinguishes it from the multitude
of calls simultaneously transmitted over the same broadcast
spectrum. So long as the receiving device has the right code, it
can pick its conversation out from all the others.
[0053] Another mechanical cluster key arrangement according to the
invention includes cluster keys which each include a primary key
circularly surrounded by a concave shaped secondary key. The
various possible shapes attributed to the primary and secondary
keys in the previously described mechanical cluster key
arrangements are also possible in this mechanical cluster key
arrangement. The cluster keys in this cluster key arrangement are
preferably constructed from material giving a large range of
hardness that may be needed to provide positive tactile feedback to
the user. As before, typically, the primary keys are each labelled
with a number, an asterisk symbol (*), or a pound sign (#). The
secondary keys are each labelled with at least one function
designation, letter, or character symbol. Each key has a first
portion of the key exposed on a first side of the cluster key
assembly, and a second and third portion of the key exposed on a
second side of the cluster key assembly. When the first portion of
a key is depressed by a user, the third portion of the key comes
into contact with a substrate while its second portion mechanically
mutually excludes any functions associated with the corresponding
secondary key of that particular cluster key from contacting the
substrate.
[0054] The primary key travels through a stepped hole in the key
cluster. When the primary key is actuated, a shoulder on the
primary key mates with steps in the secondary keys. This engagement
of the shoulder of the primary key with the steps in secondary keys
traps the secondary keys against the substrate and prevents them
from rotating and rolling over the surface of the substrate. Since
the secondary keys are actuated by rotating and rolling over the
substrate, the secondary keys can not be actuated when the primary
key is actuated.
[0055] When a secondary key is actuated by rotating and rolling
over the surface of the substrate, it positions the primary key at
an angle with the substrate. If the primary key is then depressed,
this angle will cause the edge of the primary key to contact the
substrate and prevent the bottom face of the primary key from
making contact. Since actuation of the primary key is produced by
the bottom face contacting the substrate, this prevents actuation
of the primary key when a secondary key is actuated. Each secondary
key includes a bottom surface which includes electrical traces
corresponding to the number of functions designated on they upper
surface of the secondary key. Selection of one function mutually
precludes the selection of the other secondary key functions or the
primary key function.
[0056] An electronic cluster key arrangement comprises a primary
key and at least one secondary key and is electronically configured
in the form of a transparent a touch screen liquid crystal display
(LCD) mounted within a remote telephone which includes a housing, a
speaker, and a microphone. Obviously, this electronically
configured touch screen LCD cluster key arrangement may also be
configured for use on cellular/mobile telephones, television remote
controls, other handheld data entry devices, automotive controls,
desktop/wall-mounted/cordless telephones, combination telephone
recorders, PDAs, and other electronic devices, according to the
desires of the user. The cluster keys in this electronic
configuration are preferably displayed in the form of circular,
ellipsoidal, pentagonal, etc., images as viewed from the top. The
secondary keys each preferably displayed in the form of
rectangular, trapezoidal, semi-circular, images which may be
elongated to provide more finger contact.
[0057] The housing also includes a liquid crystal display (LCD) for
displaying information for the user, a power switch, and a mode
switch. The touch screen LCD may be any conventionally configured
touch screen LCD. For example, the touch screen LCD may be
configured in the form of an upper glass sheet and a lower glass
sheet with a thin layer of liquid crystal material including a
pressure sensing element sandwiched between the glass sheets.
However, the touch screen LCD may also be configured in combination
with a transparent thin film solar cell such as a p-i-n junction
type amorphous silicon solar cell.
[0058] Many approaches to the determination of the location of X
and Y coordinates of a touch point based on sensing pressure are
well known. A pressure-sensitive input device comprising an
X-coordinate detection resistive element connected to mutually
parallel vertical conductors and a Y-coordinate detection resistive
element connected to mutually parallel horizontal conductors, for
detecting the position of a point depressed by a stylus or the
like, works by detecting changes in the resistance values of these
resistive elements. Switches are used for on-off control of the
current flowing into or out of both ends of the X-coordinate
detection resistive element and the Y-coordinate detection
resistive element, and a voltage detection circuit detects the
voltage between the X-coordinate detection resistive element and
the Y-coordinate detection resistive element. Multiple inputs can
be detected based on the results from the voltage detection circuit
when the currents are switched by the switches.
[0059] The preceding is but one approach to pressure sensing baser
location determination known in the art. A more sensitive "smart
sensor" type micro-strain gage based localized point sensor located
at the midpoint of the keycaps of the primary keys and at the
midpoint of the secondary keycaps, located along the circumference
of a circle which constitutes the "virtual circle" along which lie
the locus of the centers of the secondary keys of the various
embodiments. This sensitive pressure sensor can output an analog
pressure level and its digitized digital equivalent and likewise
the rate of change of pressure and its digitized equivalent. The
sensor is a smart sensor in that it can be embedded in the carrier
material.
[0060] The first level of mutual exclusivity is rather trivial. The
system logic will not accept inputs from two different clusters
keys; such dual activation attempt will occur when a user
inadvertently presses two adjacent secondary keys belonging to two
different clusters (the system will output an error message and
sound a beep asking the user to move the finger a little closer to
the center of the cluster). It can also occur when one purposely
tests the system by pressing keys from clusters that are not
adjacent (this will merely elicit a beep and optionally display ad
error message).
[0061] Once the finger is operating within a cluster, the finger
perhaps overlaps a little over let us say 3 keys . . . . The
intended secondary key (let us say the alphabet B), the corner of
the primary key (which is the number 2) and a portion of the
adjacent secondary key (say the letter A) . . . under these
circumstances, the pressure sensor that is distributed over the
entire "keycap" areas of both the secondary keys and the primary
key will generate a logical YES for these keys. However, the more
sensitive pressure sensor located in the middle (lower threshold)
will in most instances have an output only in the intended
secondary key of B. This output in reality has two components, an
analog level (or it digitized equivalent) representing the amount
of or relative amount of pressure (this is likely to be the highest
in the intended secondary key since presumably the finger tip is
acting on it. For further reliability, a rate input will also be
generated identical fashion. When uniqueness is established the
logical outputs from the other two keys are precluded from
proceeding further. A simple implementation would accomplish this
inside the box with conventional electronics. It is also possible
to implement this in a solid state or monolithic way by opening the
conductive pathway from the non intended keys thus making it
mutually exclusive.
[0062] A second pressure sensor, i.e., the generalized or entire
keycap based pressure sensor also needs to be there for another
case, i.e. when one attempts to provide a very clean input by using
a pen tip or stylus as is done on palmtop PDAs these days. This
capability falls under the realm of user friendliness, since there
are many users who use this method currently, albeit with a
complaint. Of course they are doing it because they have no
choice.
[0063] The touch screen LCD could be of the monochromatic type or
an active matrix full color display. As is known widely to those
skilled in the art, an active matrix generally consists of two
sheets between which is inserted an electro-optical material such
as a liquid crystal. On one of the sheets is a matrix of
transparent conductive blocks, thin film transistors, a group of
conducting addressing lines, and a group of conductive addressing
columns. Each transistor has a gate connected to a line, a source
connected to a block, and a drain connected to a column. On the
second sheet is a counter electrode. In one electronic cluster key
arrangement, on top of the liquid crystal material is attached a
flexible transparent film which has patterned thin film
semiconductor layers preferably comprising a layer of
(intrinsic)-type semiconductor disposed between a layer of p-type
semiconductor and a layer of n-type semiconductor. The p-i-n layer
is further sandwiched on either side by a thin layer of transparent
conductive layer such as tin oxide, indium tin oxide, or the like,
to constitute a p-i-n junction amorphous silicon solar cell.
[0064] A silicon solar cell connected to the emitter of a common
base amplifier biased so that the cell voltage is near to zero, a
short-circuit load can be used as a sensor. Collector load is three
forward diodes which develop an approximately logarithmic voltage
versus current in the current ranges involved. The next stage
provides the alternating current (AC) coupling for the pulses, so
that the sensitivity of the sensing system is essentially
independent of the light level on the cell. This stage is an
operational amplifier with a bypass on the feedback for high AC
gain and low direct current (DC) gain. This network also has a
low-pass net to reject noise spikes picked up from the environment.
The coverage of the conductive layers by an actuating finger causes
shadowing which results in a decreased current output proportional
to the area shadowed.
[0065] The p-i-n junction amorphous silicon solar cell is scribed,
preferably using a laser scriber, into smaller portions comprising
one primary portion and at least one peripheral secondary portion
(preferably four secondary portions around the primary portion) to
configure an electronic cluster key. The p-i-n junction amorphous
silicon solar cell include at least one vertical and horizontal
grid of transparent conductors laid in between two transparent
insulating layers of the thin film variety such as silicon dioxide.
The p-i-n junction amorphous silicon solar cell's two conductive
transparent coatings of tin oxide, indium tin oxide, or the like,
can be combined in series using techniques well known to persons
skilled in the art to provide a trickle charge at approximately
12-14 volts. One approach to series connection entails using a
laser to scribe and separate the initial tin oxide coating into
islands, using a photoresist mask on the edge to prevent the
subsequent layers of p-type, i-type, and n-type semiconductors from
touching the conductive layer. Thereafter, the mask is removed and
the second tin oxide layer is applied which connects the top
surface of the second cell to the bottom surface of the first cell,
resulting in a series connection. Other intervening steps are well
known to those versed in the art. The p-i-n junction amorphous
silicon solar cell may include capacitors and/or pressure sensors
at the center of each key which are all deposited on a flexible,
transparent substrate such as Kapton and then glued on to the LCD.
Kapton or other high temperature plastic is used to withstand high
temperatures associated with chemical vapor deposition of amorphous
silicon. It is possible to integrate the processing of the solar
cell and the touch screen LCD based on active matrix thin film
transistors (TFTs).
[0066] The touch screen LCD is preferably an active matrix TFT
display which preferably displays the primary keys as white key
with black characters for most contrast and which preferably
displays secondary key alphabet characters in a particular colors
such as red. Preferably secondary key function symbols are
displayed in green, secondary key characters such as the AT sign
(@) are displayed in blue, and secondary key control symbols such
as YES/SEND are displayed in yellow with green letters and NO/END
are displayed in yellow with red letters. Obviously, a variety off
other color assignments are possible.
[0067] The electronic cluster key arrangement is configured
utilizing a keyboard emulator within the remote telephone in
accordance with the mode selected by the user using the mode
switch. One arrangement showing an electronic cluster key
arrangement comprises a set of twelve cluster keys arranged in four
rows by three columns. Each electronically configured cluster key
includes a primary key location surrounded by at least one
secondary key location. By touching a particular key location on
the touch screen LCD, the user activates an electrical signal which
passes through an electrical matrix formed by a plurality of
contact lines interconnecting each of the particular key locations.
The electrical signal is delivered to a processing unit stored
within the remote telephone, which is then converted into a symbol
and displayed on the LCD. The remote telephone also includes
circuitry which precludes the simultaneous activation of more than
one key location of a particular cluster key.
[0068] The electronic or opto-electronic mutually exclusive cluster
key arrangement works on the same basis of preprocessing as was
done in the mechanical cluster key arrangements wherein only one
signal could be generated at a time. In the electronic cluster key
arrangement the preprocessing is based on sensing one or more
variables such as contact pressure or shadowing of a solar cell's
microcell element. Both analog levels and digital/logical inputs
are used in preprocessing. Other types of sensing such as
capacitive is also possible. Appropriate grid work of conductors
and electronics which is well known to those skilled in the art
will be used, entailing the use of digital and analog mutiplexers,
operational amplifiers polling elements and the like. In a pure LCD
cluster key arrangement, wherein a pressure sensor alone is the
sensing element, in the trivial case where one uses a stylus, such
as is done in the use of PDAs currently available in the market the
sensing and interpretation is easy. These preceding devices do not
work with fingers reliably since the keycaps are too small.
[0069] In the present invention, since there is a certain amount of
shared "real estate" due to clustering, the user is intentionally
allowed to press part of an adjacent key (principally the primary
key while pressing a secondary key). The present invention utilizes
a distributed or wide area logical pressure sensor alone which
provides a logical YES output for a selected positional area, or a
low threshold central pressure sensor in combination with other
detected readings such as an applied pressure, applied pressure
rate, or shadowing. However, the pressure sensing area is mostly in
a restricted smaller area around the center. The centers al of the
adjacent keys are located far enough apart that they result in one
or more different levels of pressure generated by a pressing
finger. The key associated with the higher level is selected as
representing the fingertip which better represents the intended
key. In the embodiment with the solar cell, the pressing of a key
generates both an analog signal representing the amount of
shadowing of a key cap by a operating finger and a digital/logical
output which are used in pre-processing singly or in combination
with the outputs from the pressure sensor. One approach involves
picking for comparison of the shadowing levels only those keys
whose pressure sensors have generated a logical YES and
simultaneously picking for comparison of the pressure levels only
those keys whose shadowing has generated a logical YES. In this
scheme of preprocessing, at any stage upon identifying a reliable
output such as by the use of a logical AND of the pressure and
shadow/solar cell sensors further processing is stopped. The early
and reliable identification of an input precludes the activation or
consideration of another input in this mutually exclusive
electronic cluster key arrangement.
[0070] The invention is believed to reside in the cluster key per
se, the various arrangements thereof, the combination of knows
electronic circuitry, and the overall combination of cooperating
telephones, PDAs or the like including the Internet at large.
Furthermore, the invention may be easily implemented in a manner
that is compatible with the existing prior art in terms of user
friendliness, such as allowing a user to operate a device in a
numeric mode, an alphabetic mode, or the like.
[0071] Accordingly, it is a principal object of the invention to
provide a cluster key arrangement that enables a user to select one
of a plurality of characters representing numbers, letters,
symbols, functions, etc., in a mutually exclusive manner.
[0072] It is another object of the invention to provide a cluster
key arrangement in a mechanical configuration.
[0073] It is yet another object of the invention to provide a
cluster key arrangement in an electronic configuration.
[0074] It is a further object of the invention to provide a mobile
telephone having a touch screen LCD with an electronic cluster key
configuration.
[0075] Still another object of the invention is to provide a mobile
or palmtop computer based Personal Digital Assistant having a color
touch screen LCD with electronic cluster keys with various
configurations as chosen by the user with built-in functions of a
cellular telephone resulting in a combination cellphone/PDA that
has a bigger display area without exceeding the overall dimensions
and which provides for a longer talk/useage time per battery.
charge.
[0076] It is an object of the invention to provide improved
elements and arrangements thereof in a mechanical or electronic
cluster keys arrangement for the purposes described which is
inexpensive, dependable and fully effective in accomplishing its
intended purposes.
[0077] These and other objects of the present invention will become
readily apparent upon further review of the following specification
and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0078] FIG. 1 is a front perspective view of a cluster key
arrangement according to the present invention.
[0079] FIG. 2 is a top view of a mechanical cluster key arrangement
according to the present invention configured in the form of a
telephone.
[0080] FIG. 3 is a top view of a mechanical cluster key arrangement
according to the present invention.
[0081] FIG. 4 is a side perspective view of a mechanical cluster
key according to the present invention.
[0082] FIG. 5 is an exploded view of the mechanical cluster key
shown in FIG. 4.
[0083] FIG. 6A is a substrate electrical contact for the mechanical
cluster key shown in FIG. 4 in accordance with the present
invention.
[0084] FIG. 6B is a cross-sectional view of the substrate
electrical contact shown in FIG. 6A.
[0085] FIG. 7 is a front perspective view of a mechanical cluster
key arrangement according to the present invention.
[0086] FIG. 8A is an exploded perspective view of a cluster key
from the cluster key arrangement shown in FIG. 7.
[0087] FIG. 8B is a cross-sectional view of the cluster key shown
in FIG. 8A.
[0088] FIG. 9 is a bottom view of the cluster key shown in FIG.
8A.
[0089] FIG. 10A is a front view of a mobile telephone with a touch
screen LCD utilizing an electronic cluster key configuration
according to the invention.
[0090] FIG. 10B is a front perspective view of a p-i-n junction
amorphous silicon solar cell according to the invention.
[0091] Similar reference characters denote corresponding features
consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0092] The present invention is a cluster key arrangement. The
cluster key arrangement may be mechanically configured or
electronically configured. A mechanical cluster key arrangement
according to the invention is shown in FIG. 1. This mechanical
cluster key arrangement 10 includes twelve cluster keys configured
in an arrangement of three columns by four rows, such as
conventionally found on standard telephones. This cluster key
arrangement 10 may also be configured for use on cellular/mobile
telephones, television remote controls, other handheld data entry
devices, automotive controls, desktop/wall-mounted/cordless
telephones, combination telephone recorders, PDAs, and other
electronic devices. The cluster keys provide the user with the
ability to select one of a plurality of key elements representing
numbers, letters, symbols, functions, etc., in a mutually exclusive
manner.
[0093] The cluster keys shown in FIG. 1 each include a primary key
12 surrounded by four secondary keys 14. However, a cluster key
arrangement according to the invention may obviously include a
primary key and any number of secondary keys, i.e., one, two,
three, etc. The number of secondary keys is preferably in the range
of four to eight. The cluster keys are preferably constructed from
material giving a large range of hardness that may be needed to
provide positive tactile feedback to the user. The primary key 12
for a particular cluster key preferably includes a dome or convex
shaped button profile further shaped circularly, ellipsoidally,
pentagonally, etc., as viewed from the top. The dome or convex
shaped primary key profile as it reaches the vicinity of the
associated secondary keys 14 assumes a concave profile. While a
concave profile may be substituted for a dome, other button shapes,
as viewed from the top, such as hexagonal, heptagonal, or octagonal
may be substituted. The secondary keys 14 preferably each have a
concave profile starting at the perimeter of the primary key
somewhat underneath the primary key 12 in elevation and rises up in
a concave arcuate profile to increase the contact surface area of
the fingertip for better pressure distribution and ends with a
greater width such as obtained by the wide end of a trapezoid, for
providing a greater width to the finger to act on, and ends at an
elevation which is slightly lower than the top elevation of the
dome of the primary key 12, with which it is clustered. Other
secondary key profiles, as viewed from the top, may include shapes
such as rectangular, trapezoidal, semi-circular, which may be
elongated to provide more finger contact.
[0094] The primary keys 12 are each labelled with a number, an
asterisk symbol (*), or a pound sign (#). The secondary keys 14 are
preferably nominally small in relation to the associated primary
key 12 to accommodate space constraints. The secondary keys 14
preferably each include an arcuate concave surface which increases
the surface area of contact for better pressure distribution at the
finger tip of the user. Preferably, the outer edge of the secondary
keys 14 flares out to provide a greater width on which a finger may
act. The secondary keys 14 are each labelled with a function
designation, letters, or character symbols.
[0095] Each primary key 12 has a first portion of the key exposed
on a first side of the associated key cluster, and a second portion
and third portion of the key exposed on a second side of the key
cluster. When the first portion of a primary key 12 is depressed by
a user, the second portion of the primary key 12 comes into contact
with the second portions of the associated secondary keys with
which it is clustered and mechanically mutually excludes any of the
corresponding secondary keys' third portions of that particular key
cluster from contacting a substrate such as a printed circuit board
or an intermediate layer of an elastomeric sheet that has hat like
protrusions with attached conductive elements under the hats to
complete a circuit upon being depressed. If the primary key 12 of a
cluster key is depressed, none of the associated secondary keys may
contact the substrate. If a secondary key of a cluster key is
depressed preferably neither the associated primary key nor the
remaining associated secondary keys may contact the substrate. It
is possible that if a secondary key is of a cluster key is
depressed, at least two of the immediately adjacent secondary keys
will be precluded from acting on the substrate.
[0096] A perspective view and an exploded view of one of these key
clusters 100 is shown in FIGS. 4 and 5, wherein a primary key 101
is surrounded by four secondary keys 104 that each pivot about a
pivot axis 106. As shown, the primary key 101 includes a first
portion of the key exposed on a first side of the associated key
cluster, and a second portion 103 and third portion 102 of the key
exposed on a second side of the key cluster. If the primary key 101
of the cluster key is depressed, none of the associated secondary
keys 104 may contact the substrate. If a secondary key 104 of the
cluster key is depressed neither the associated primary key 101 nor
preferably the remaining associated secondary keys 104 may contact
the substrate, since secondary key mutual exclusivity actuator 108
precludes it. However, it is possible to mechanically configure a
cluster key arrangement wherein two secondary keys of a particular
cluster key may be simultaneously depressed. In that case a
processor operating in conjunction with the cluster key arrangement
would not generate a signal in response to such activity, and may
generate a error signal to the user.
[0097] One technique for detecting a depressed condition of a key
utilizes a capacitive key wherein a key circuit element forms two
spaced apart metallic areas and one key and has a plated pad formed
from a metal such as tin, nickel, or copper such that when the key
end is brought in close proximity to the current element, a
capacitive charge is noted by a keypad circuit board and a
key-depressed state is acknowledged by a corresponding keyboard
microprocessor and logic unit. An alternative construction
incorporates a hardcontact keyboard, wherein the key has a stem
which directly engages with the concave cavity, in close proximity
with a pair of contacts comprising the circuit element which are
then brought into electrically communicative relationship
therebetween. As shown in FIGS. 6A and 6B, such a configuration for
use in association with the cluster key shown in FIGS. 4 and 5
include physical shell caps 160 on a flexible board 158 spaced from
a circuit board 164 which includes metallic contacts 166. The shell
caps 160 each include a metallic element 162 within the cap 160.
When a user presses one button of a selected cluster key, a signal
is generated when the key bottom of the key presses a shell cap 160
and causes the associated metallic element 162 to contact a
metallic contact 166.
[0098] A mechanical cluster key arrangement configured for use on a
remote telephone 20 is shown in FIG. 2 which includes a housing 22,
a speaker 24, and a microphone 26. The housing 22 also includes a
liquid crystal display (LCD) 28. Openings in the housing are
provided for the individual cluster keys. In addition, although not
shown, the remote telephone 20 may also include a buzzer, indicator
lights, and other features, depending upon a particular design or
model. The remote telephone 20 includes a main printed, circuit
board (not shown) which includes all of the major radio frequency
(RF) and logic circuits required to provide at least basic cellular
telephone service and support a variety of features. Such circuits
typically include a plurality of chips, integrated circuits, and
other components interconnected formed within, or on the surface,
of the printed circuit board. The remote telephone 20 also includes
an antenna 30 that extends through an aperture provided in the
housing 22 and is electrically connected to the printed circuit
board. The housing 22 encloses a substrate on which are mounted the
closing switches and the dial pulse circuit which is controlled by
these switches. Upon reception of RF signals, the mobile telephone
20 receives the RF signals through the antenna 30. The antenna 30
converts the received RF signals into electrical RF signals for use
by the radio circuitry. The radio circuitry demodulates the
electrical RF signals and recovers the data transmitted using the
RF signals. Additionally, the radio circuitry outputs the data to a
processor. The processor includes at least a main processor and
associated memory as well as other control circuits including
integrated circuits or other known technologies. The processor
formats the data output from the radio circuitry into a
recognizable voice or message information for use by the user
interface. The user interface communicates the received information
or voice to a user through the use of the speaker 24 and the
display 28. All digital or all analog or combinations of analog and
digital network based cellular telephone services are possible.
[0099] Unlike present analog systems and other digital systems that
divide the available spectrum into narrow channels and assign one
or more conversations to each channel, CDMA is a wideband spread
spectrum technology that spreads multiple conversations across a
wide segment of the broadcast spectrum. Each telephone or data call
is assigned a unique code that distinguishes it from the multitude
of calls simultaneously transmitted over the same broadcast
spectrum. So long as the receiving device has the right code, it
can pick its conversation out from all the others.
[0100] The mechanical cluster keys shown in FIG. 2 each include a
primary key 32 and five secondary keys. As stated before, a cluster
key arrangement according to the invention may obviously include a
primary key and any number of secondary keys, i.e., one, two,
three, etc. The selected number of secondary keys is preferably in
the range of four to eight. The cluster keys are preferably
constructed from material giving a large range of hardness that may
be needed to provide positive tactile feedback to the user. The
primary key 32 for a particular cluster key preferably includes a
dome or convex shaped button profile further shaped circularly,
ellipsoidally, pentagonally, etc., as viewed, from the top. The
dome or convex shaped primary key profile as it reaches the
vicinity of the associated secondary keys assumes al go concave
profile. While a concave profile may be substituted for a dome,
other button shapes, as viewed from the top, such as hexagonal,
heptagonal, or octagonal may be substituted. The associated
secondary keys each preferably have a concave profile starting at
the perimeter of the primary key somewhat underneath the primary
key in elevation and rises up in a concave arcuate profile to
increase the contact surface area of the fingertip for better
pressure distribution and ends with a greater width such as
obtained by the wide end of a trapezoid, for providing a greater
width to the finger to act on, and ends at an elevation which is
slightly lower than the top elevation of the dome of the primary
key, with which it is clustered. Other secondary key profiles, as
viewed from the top, may include shapes such as rectangular,
trapezoidal, semi-circular, which may be elongated to provide more
finger contact.
[0101] The primary keys 32 are each labelled with a number, an
asterisk symbol (*), or a pound sign (#). The secondary keys are
each labelled with a function designation, letters, or character
symbols. In this mechanical cluster key arrangement, the primary
key labelled "1" is surrounded by unmarked secondary keys 34, 36,
38, 40 and a secondary key labelled with "!". While the secondary
keys 34, 36, 38, 40 may obviously be labelled according to the
desires of the user, preferably secondary key 34 is labelled "CLR",
secondary key 36 is labelled "YES/SEND", secondary key 38 is
labelled "PWR ON/OFF", and secondary key 40 is labelled "NO/END".
Each key is disposed within the housing. The primary key labelled
"4" includes an unmarked secondary key 42 which is preferably
labelled "CTRL". The primary key labelled "5" includes an unmarked
secondary key 44 which is preferably labelled "ALT". The primary
key labelled "6" includes an unmarked secondary key 46 which is
preferably labelled "ENTER". The primary key labelled "8" includes
an unmarked secondary key 48 which is preferably labelled with an
accent mark. The primary key labelled "0" includes an unmarked
secondary key 50 which is preferably labelled "SPACE BAR". The
primary key labelled "#" includes an unmarked secondary key 52
which is preferably labelled with an underscore. The primary key
labelled "#" also includes another unnumbered unmarked secondary
key which is preferably labelled "MODE". Each key has a first
portion of the key exposed on a first side of the housing and a
second portion of the key exposed on a second side of the housing.
When the first portion of a key is depressed by a user, the second
portion of the key comes into contact with a substrate and
mechanically mutually excludes any of the corresponding keys of
that particular key cluster from contacting the substrate. These
cluster keys function in the same manner as the cluster key shown
in FIGS. 4 and 5, wherein a primary key is surrounded by secondary
keys which pivot about a pivot axis. If the primary key of a
cluster key is depressed, none of the associated secondary keys may
contact the substrate. If a secondary key of a cluster key is
depressed preferably neither the associated primary key nor the
remaining associated secondary keys may contact the substrate. It
is possible that if a secondary key of a cluster key is depressed,
at least two of the immediately adjacent secondary keys will be us
precluded from acting on the substrate on account of secondary keys
mutual exclusivity actuator 108.
[0102] One technique for detecting a depressed condition of a key
utilizes a capacitive key wherein the key circuit element forms two
spaced apart metallic areas and has a plated pad formed from a
metal such as tin, nickel, or copper such that when the key end is
brought in close proximity to the current element, a capacitive
charge is noted by the circuit board and a key-depressed state is
acknowledged by a corresponding keyboard microprocessor and logic
unit. An alternative construction incorporates a hardcontact
keyboard, wherein the key has a stem which directly engages with
the concave cavity, in close proximity with a pair of contacts
comprising the circuit element which are then brought into
electrically communicative relationship therebetween, previously
described.
[0103] Another mechanical cluster key arrangement 60 according to
the invention is shown in FIG. 3. The cluster keys in this cluster
key arrangement 60 each include a primary key 62 surrounded by six
secondary keys. As stated above, a cluster key arrangement
according to the invention may obviously include a primary key and
any number of secondary keys, i.e., one, two, three, etc. The
number of secondary keys is preferably in the range of four to
eight. The cluster keys are preferably constructed from material
giving a large range of hardness that may be needed to provide
positive tactile feedback to the user. The primary key for a
particular cluster key preferably includes a dome or convex shaped
button profile further shaped circularly, ellipsoidally,
pentagonally, etc., as viewed from the top. The dome or convex
shaped primary key profile as it reaches the vicinity of the
associated secondary keys assumes a concave profile. While a
concave profile may be substituted for a dome, other button shapes,
as viewed from the top, such as hexagonal, heptagonal, or octagonal
may be substituted. The secondary keys each have a concave profile
starting at the perimeter of the primary key somewhat underneath
the primary key in elevation and rises up in a concave arcuate
profile to increase the contact surface area of the fingertip for
better pressure distribution and ends with a greater width such as
obtained by the wide end of a trapezoid, for providing a greater
width to the finger to act on, and ends at an elevation which is
slightly lower than the top elevation of the dome of the primary
key, with which it is clustered. Other secondary key profiles, as
viewed from the top, may include shapes such as rectangular,
trapezoidal, semi-circular, which may be elongated to provide more
finger contact. The primary keys 62 are each labelled with a
number, an asterisk symbol (*), or a pound sign (#). The secondary
keys are each labelled with a function designation, letters, or
character symbols. Each key is disposed within the housing. In this
cluster key arrangement, the primary key 62 labelled "1" is
surrounded by unmarked secondary keys 64, 66. While the secondary
keys 64, 66 may obviously be labelled according to the desires of
the user, preferably secondary key 64 is labelled "NO/END", and
secondary key 66 is labelled "YES/SEND". The primary key labelled
"2" includes an unmarked secondary key 68 which is preferably
labelled "MODE" . The primary key labelled "3" includes an unmarked
secondary key 70 which is preferably labelled "ENTER". The primary
key labelled "8" includes an unmarked secondary key 72 which is
preferably labelled "ALT". The primary key labelled "*" includes an
unmarked secondary key 74 which is preferably labelled "F10". The
primary key labelled "*" also includes an unmarked secondary key 76
which is preferably labelled "CTRL". The primary key labelled "0"
includes an unmarked secondary key 78 which is preferably labelled
"F11". The primary key labelled "#" includes an unmarked secondary
key 80 which is preferably labelled "F12". The primary key labelled
"#" also includes an unmarked secondary key 82 which is preferably
labelled "SPACE BAR". The primary key labelled "#" also includes
another unnumbered unmarked secondary key which is preferably
labelled "MODE". Each key has a first portion of the key exposed on
a first side of the housing and a of the key exposed on a second
side of the housing. When the first portion of a key is depressed
by a user, the of the key comes into contact with a substrate and
mechanically mutually excludes any of the corresponding keys of
that particular key cluster from contacting the substrate. These
cluster keys function in the same manner as the cluster key shown
in FIGS. 4 and 5, wherein a primary key is surrounded by secondary
keys which each pivot about a pivot axis. If a primary key 62 is
depressed, none of the secondary keys associated with that key
cluster may contact the substrate. If a secondary key is depressed
neither the primary key nor the remaining secondary keys may
contact the substrate.
[0104] One technique for detecting a depressed condition of a key
utilizes a capacitive key wherein a key circuit element forms two
spaced apart metallic areas and one key and has a plated pad formed
from a metal such as tin, nickel, or copper such that when the key
end is brought in close proximity to the current element, a
capacitive charge is noted by a keypad circuit board and a
key-depressed state is acknowledged by a corresponding keyboard
microprocessor and logic unit. An alternative construction
incorporates a hardcontact keyboard, wherein the key has a stem
which directly engages with the concave cavity, in close proximity
with a pair of contacts comprising the circuit element which are
then brought into electrically communicative relationship
therebetween.
[0105] Another mechanical cluster key arrangement 110 according to
the invention is shown in FIG. 7. The cluster keys in this cluster
key arrangement 110 each include a primary key 112 circularly
surrounded by a concave shaped secondary key 116, as more
particularly shown in FIGS. 8A, 8B, and 9. The various possible
shapes attributed to the primary and secondary keys in previously
described mechanical cluster key arrangements are also possible in
this mechanical cluster key arrangement. The cluster keys in this,
mechanical cluster key arrangement are preferably constructed from
material giving a large range of hardness that may be needed to
provide positive tactile feedback to the user. As before,
typically, the primary keys 112 are each labelled with a number, an
asterisk symbol (*), or a pound sign (#). The secondary keys 116
are each labelled with at least one function designation, letter,
or character symbol. Each key has a first portion of the key
exposed on a first side of the cluster key assembly 110 and a of
the key exposed on a second side of the cluster key assembly 110.
When the first portion of a key is depressed by a user, the of the
key comes into contact with a substrate and mechanically mutually
excludes any functions associated with the corresponding secondary
key of that particular key cluster from contacting the substrate.
If a primary key 112 is depressed, the secondary key 116 associated
with that key cluster may contact the substrate. If a secondary key
116 is depressed the primary key 112 may not contact the substrate.
As shown in FIG. 9, each secondary key 116 includes a convex bottom
surface 118 which includes electrical traces 119 corresponding to
the number of functions designated on the concave upper surface 117
of the secondary key 116. Selection of one function mutually
precludes the selection of the other secondary key functions or the
primary key 112 function.
[0106] One technique for detecting a depressed condition of a key
utilizes a capacitive key wherein a key circuit element forms two
spaced apart metallic areas and has a plated pad formed from a
metal such as tin, nickel, or copper such that when the key end is
brought in close proximity to the current element, a capacitive
charge is noted by a keypad circuit board and a key-depressed state
is acknowledged by a corresponding keyboard microprocessor and
logic unit. An alternative construction incorporates a hard-contact
keyboard, wherein the key has a stem which directly engages with
the concave cavity, in close proximity with a pair of contacts
comprising the circuit element which are then brought into
electrically communicative relationship therebetween.
[0107] Each key has a first portion of the key exposed on a first
side of the cluster key assembly, and a second and third portion of
the key exposed on a second side of the cluster key assembly. When
the first portion of a key is depressed by a user, the third
portion of the key comes into contact with a substrate while its
second portion mechanically mutually excludes any functions
associated with the corresponding secondary key of that particular
key cluster from contacting the substrate.
[0108] The primary key 112 travels through a stepped hole-in the
key cluster. When the primary key 112 is actuated, a shoulder 114
on the primary key 112 mates with steps 119 in the associated
secondary key 116. This engagement of the shoulder 114 of the
primary key 112 with steps in the secondary key 116 traps the
secondary key 116 against the substrate and prevents it from
rotating and rolling over the surface of the substrate. Since the
secondary key 116 is actuated by rotating and rolling over the
substrate, the secondary key 116 can not be actuated when the
primary key 112 is actuated.
[0109] When a secondary key 116 is actuated by rotating and rolling
over the surface of the substrate, it positions the associated
primary key 112 at an angle with the substrate. If the associated
primary key 112 is then depressed, this angle will cause the edge
of the primary key 112 to contact the substrate and prevent the
bottom face 115 of the primary key 112 from making contact. Since
actuation of the primary key 112 is produced by the bottom face 115
contacting the substrate, this prevents actuation of the primary
key 112 when the associated secondary key 116 is actuated.
[0110] An electronic cluster key arrangement according to the
invention is shown in FIG. 10A. This cluster key arrangement is
electronically configured in the form of a touch screen liquid
crystal display (LCD) 132 mounted within a remote telephone 120
which includes a housing 122, a microphone 124, and a speaker 126.
obviously, this electronically configured touch screen LCD cluster
key arrangement may also be configured for use on cellular/mobile
telephones, television remote controls, other handheld data entry
devices, automotive controls, desktop/wall-mounted/cordless
telephones, combination telephone recorders, PDAs, and other
electronic devices, according to the desires of the user.
[0111] The cluster keys in this electronic configuration are
preferably displayed in the form of circular, ellipsoidal,
pentagonal, etc., images as viewed from the top. The secondary keys
each preferably displayed in the form of rectangular, trapezoidal,
semi-circular, images which may be elongated to provide more finger
contact. The preceding images may be similar to those shown in
FIGS. 1, 2, 3, and 7. The housing 122 also includes a liquid
crystal display (LCD) 130 for displaying information for the user,
a power switch 134, and a mode switch 136. The touch screen LCD may
be any conventionally configured touch screen LCD. For example, the
touch screen LCD may be configured in the form of an upper glass
sheet and a lower glass sheet with a thin layer of liquid crystal
material including al pressure sensing element sandwiched between
the glass sheets. However, the touch screen LCD may also be
configured in combination with a transparent thin film solar cell
such as a p-i-n junction type amorphous silicon solar cell 140, as
shown in FIG. 10B.
[0112] Many approaches to the determination of the location of X
and Y coordinates of a touch point based on sensing pressure are
well known. A pressure-sensitive input device comprising an
X-coordinate detection resistive element connected to mutually
parallel vertical conductors and a Y-coordinate detection resistive
element connected to mutually parallel horizontal conductors, for
detecting the position of a point depressed by a stylus or the
like, works by detecting changes in the resistance values of these
resistive elements. Switches are used for on-off control of the
current flowing into or out of both ends of the X-coordinate
detection resistive element and the Y-coordinate detection
resistive element, and a voltage detection circuit detects the
voltage between the X-coordinate detection resistive element and
the Y-coordinate detection resistive element. Multiple inputs can
be detected based on the results from the voltage detection circuit
when the currents are switched by the switches.
[0113] The preceding is but one approach to pressure sensing based
location determination known in the art. A more sensitive "smarts
sensor" type micro-strain gage based localized point sensor located
at the midpoint of the keycaps of the primary keys and at the
midpoint of the secondary keycaps, located along the circumferences
of a circle which constitutes the "virtual circle" along which lie
the locus of the centers of the secondary keys of the various a
electronic arrangements. This sensitive pressure sensor can output
an analog pressure level and its digitized digital equivalent and
likewise the rate of change of pressure and its digitized
equivalent. The sensor is a smart sensor in that it can be embedded
in the carrier material.
[0114] The touch screen LCD 132 could be of the monochromatic type
or an active matrix full color display. As is known widely to those
skilled in the art, an active matrix generally consists of two
sheets between which is inserted an electro-optical material such
as a liquid crystal. On one of the sheets is a matrix of
transparent conductive blocks, thin film transistors, a group of
conducting addressing lines, and a group of conductive addressing
columns. Each transistor has a gate connected to a line, a source
connected to a block, and a drain connected to a column. On the
second sheet is a counter electrode. On top of the liquid crystal
material is attached a flexible transparent film which has
patterned thin film semiconductor layers preferably comprising a
layer of i(intrinsic)-type semiconductor disposed between a layer
of p-type semiconductor and a layer of n-type semiconductor. The
p-i-n layer is further sandwiched on either side by a thin layer of
transparent conductive layer such as tin oxide, indium tin oxide,
or the like to constitute a p-i-n junction amorphous silicon solar
cell.
[0115] A silicon solar cell connected to the emitter of a common
base amplifier biased so that the cell voltage is near to zero, a
short-circuit load can be used as a sensor. Collector load is three
forward diodes which develop an approximately logarithmic voltage
versus current in the current ranges involved. The next stage
provides the AC coupling for the pulses, so that the sensitivity of
the sensing system is essentially independent of the light level on
the cell. This stage is an operational amplifier with a bypass on
the feedback for high AC gain and low direct current DC gain. This
network also has a low-pass net to reject noise spikes picked up
from the environment. The coverage of the conductive layers by an
actuating finger causes shadowing which results in a decreased
current output proportional to the area shadowed.
[0116] A preferable p-i-n junction amorphous silicon solar cell 140
is shown in FIG. 10B. This p-i-n junction amorphous silicon solar
cell 140 includes nine layers 141-149. Layer 141 is a transparent
conductive tin oxide layer. Layer 142 is a transparent layer of
p-type semiconductor. Layer 143 is a transparent layer of i-type
semiconductor. Layer 144 is a transparent layer of n-type
semiconductor. Layer 145 is a transparent conductive tin oxide
layer. Layer 146 is a transparent insulating silicon-dioxide layer.
Layer 147 is a transparent layer containing a horizontal or
vertical electrical grid. Layer 148 is a transparent insulating
silicon-dioxide layer. Layer 149 is a transparent layer containing
a horizontal or vertical electrical grid. Once this p-i-n junction
amorphous silicon solar cell 140 is attached to an LCD, the solar
cell 140 is covered with a transparent plastic layer to protect the
cell from the environment. In actuality the solar cell and
associated layers are deposited on the plastic layer which is then
inverted and attached to the glass.
[0117] The p-i-n junction amorphous silicon solar cell is scribed
into smaller portions comprising one primary portion and at least
one peripheral secondary portion (preferably four secondary
portions around the primary portion) to configure an electronic
cluster key. The p-i-n junction amorphous silicon solar cell
include at least one vertical and horizontal grid of transparent
conductors laid in between two transparent insulating layers of the
thin film variety such as silicon dioxide. The p-i-n junction
amorphous silicon solar cell's two conductive transparent coatings
of tin oxide, indium tin oxide, or the like, can be combined in
series using techniques well known to persons skilled in the art to
provide a trickle charge at approximately 12-14 volts. One approach
to series connection entails using a laser to scribe and separate
the initial tin oxide coating into islands, using a photoresist
mask on the edge to prevent the subsequent layers off p,i,n from
touching the conductive layer. Thereafter, the mask is removed and
the second tin oxide layer is applied which connects the top
surface of the second cell to the bottom surface of the first cell,
resulting in a series connection. Other intervening steps are well
known to those skilled in the art. The p-i-n junction amorphous
silicon solar cell may include capacitors and/or pressure sensors
at the center of each key which are all deposited on a flexible
transparent substrate such as Kapton and then glued on to the LCD.
Kapton or other high temperature plastic is used to withstand high
temperatures associated with chemical vapor deposition of amorphous
silicon. It is possible to integrate the processing of the solar
cell and the LCD based on active matrix thin film transistors
(TFTs).
[0118] The LCD is preferably an active matrix TFT display which
preferably displays the primary key as a white key with black
characters for most contrast and which preferably displays the
secondary key alphabet characters in a particular color such as
red. Preferably secondary key function symbols are displayed in
green, secondary key characters such as the AT sign (@) are
displayed in blue, and secondary key control symbols such as,
YES/SEND are displayed in yellow with green letters and NO/END are
displayed in yellow with red letters. Obviously, a variety of other
color assignments are possible.
[0119] The cluster key arrangement is configured utilizing a
keyboard emulator within the remote telephone in accordance with
the mode selected by the user using the mode switch. FIG. 10A
illustrates one arrangement showing a cluster key arrangement
comprising a set of twelve cluster keys arranged in four rows by
three columns. The, primary key for a particular cluster key is
preferably displayed in the form of a circularly, ellipsoidally,
pentagonally, etc., shaped image as viewed from the top. The
secondary keys are each preferably displayed in the form of a
rectangularly, trapezoidally, or semi-circularly, shaped image
which may be elongated to provide more finger contact. Each
electronically configured cluster key includes a primary key
location 138 surrounded by at least one secondary key location 140.
By touching a particular key location on the touch screen LCD 132,
the user activates an electrical signal which passes through an
electrical matrix formed by a plurality of contact lines 142
interconnecting each of the particular key locations. The
electrical signal is delivered to a processing unit stored within
the remote telephone 120, which is then converted into a symbol and
displayed on the LCD 130. The remote telephone also includes
circuitry which precludes the simultaneous activation of more than
one key location of a particular cluster key.
[0120] The electronic or opto-electronic mutually exclusive cluster
key arrangement works on the same basis of preprocessing as was
done in the mechanical cluster key arrangements wherein only one
signal could be generated at a time. In the electronic cluster key
arrangement the preprocessing is based on sensing one or more
variables such as contact pressure or shadowing of a solar cell's
microcell element. Both analog levels and digital/logical inputs
are used in preprocessing. Other types of sensing such as
capacitive is also possible. Appropriate grid work of conductors
and electronics which is well known to those skilled in the art
will be used, entailing the use of digital and analog mutiplexers,
operational amplifiers polling elements and the like. In a pure LCD
cluster key arrangement, wherein a pressure sensor alone is the
sensing element, in the trivial case where one uses a stylus, such
as is done in the use of PDAs currently available in the market
place called "Palmtops" (made by 3Com, Hewlett Packard, Casio,
Philips, etc.) the sensing and interpretation is easy. These
devices utilize a distributed or wide area logical pressure sensor
which provides a logical YES output for a selected positional area.
These preceding devices do not work with fingers reliably since the
keycaps are too small.
[0121] In the present invention, since there is a certain amount of
shared "real estate" due to clustering, the user is intentionally
allowed to press part of an adjacent key (principally the primary
key while pressing a secondary key. Many approaches to the
determination of the location of X and Y coordinates of a touch
point based on sensing pressure are well known. A pressure
sensitive input device comprising an X-coordinate detection
resistive element connected to mutually parallel vertical
conductors and a Y-coordinate detection resistive element connected
to mutually parallel horizontal conductors, for detecting the
position of a point depressed by a stylus or the like, works by
detecting changes in the resistance values of these resistive
elements.
[0122] The present invention utilizes either a distributed or wide,
area logical pressure sensor alone which provides a logical YES
output for a selected positional area, or a low threshold central
pressure sensor in combination with other detected readings such as
an applied pressure, rate of applied pressure, or shadowing.
Switches are used for on-off control of the current flowing into or
out of both ends of the X-coordinate detection resistive element
and the Y-coordinate detection resistive element, and a voltage
detection circuit detects the voltage between the X-coordinate
detection resistive element and the Y-coordinate detection
resistive element. Multiple inputs can be detected based on the
results from the voltage detection circuit when the currents are
switched by the switches.
[0123] The preceding is but one approach to pressure sensing based
location determination known in the art. A more sensitive "smart
sensor" type micro-strain gage based localized point sensor located
at the midpoint of the keycaps of the primary keys and at the
midpoint of the secondary keycaps (the midpoints are mildly
textured to facilitate tactile feedback without optical
degradation), located along the circumference of a circle which
constitutes the "virtual circle" along which lie the locus of the
centers of the secondary keys of the various electronic
arrangements. This sensitive pressure sensor can output an analog
pressure level and its digitized digital equivalent and likewise
the rate of change of pressure and its digitized equivalent. The
sensor is a smart sensor in that it can be embedded in the carrier
material.
[0124] The first level of mutual exclusivity is rather trivial. The
system logic will not accept inputs from two different cluster
keys; such dual activation attempt will occur when a user
inadvertently presses two adjacent secondary keys belonging to two
different clusters (the system will output an error message and
sound a beep asking the user to move the finger a little closer to
the center of the cluster). It can also occur when one purposely
tests the system by pressing keys from clusters that are not
adjacent (this will merely elicit a beep and optional error
message). Once the finger is operating within a cluster, the finger
perhaps overlaps a little over let us say 3 keys . . . . The
intended secondary key (let us say the alphabet B), the corner of
the primary key (which is the number 2) and a portion of the
adjacent secondary key (say the letter A) . . . under these
circumstances, the pressure sensor that is distributed over the
entire "keycap" areas of both the secondary keys and the primary
key will generate a logical YES for these keys. However, the more
sensitive pressure sensor located in the middle (lower threshold),
will in most instances have an output only in the intended
secondary key of B. This output in reality has two components, an
analog level (or its digitized equivalent) representing the amount
of or relative amount of pressure (this is likely to be the highest
in the intended secondary key since presumably the finger tip is
acting on it. For further reliability, a rate input will also be
generated in identical fashion. When uniqueness is established the
logical outputs from the other two keys are precluded from
proceeding further. A simple implementation would accomplish this
inside the box with conventional electronics. It is also possible
to implement this in solid state or monolithic way by opening the
conductive pathway from the non intended keys thus making it
mutually exclusive. It is noted that a second pressure sensor,
i.e., the generalized pressure sensor also needs to be there for
another case, i.e. when one attempts to provide a very clean input
by using a pen tip or stylus as is done on Palmtops these days. Of
course they are doing it because the current art is deficient in
that it provides no choice of finger actuation because the keycaps
are based on the emulation of QWERTY type keys which are tiny.
[0125] However, the pressure sensing area is mostly in a restricted
smaller area around the center. The centers of the adjacent keys
are located far enough apart that they result in one or more
different levels of pressure generated by a pressing finger. The
key associated with the higher level is selected as representing
the fingertip which better represents the intended key. In the
embodiment with the solar cell, the pressing of a key generates
both an analog signal representing the amount of shadowing of a key
cap by a operating finger and a digital/logical output which are
used in pre-processing singly or in combination with the outputs
from the pressure sensor. One approach involves picking for
comparison of the shadowing levels only those keys whose pressure
sensors have generated a logical YES and simultaneously picking for
comparison of the pressure levels only those keys whose shadowing
has generated a logical YES. In this scheme of preprocessing, at
any stage upon identifying a reliable output such as by the use of
a logical AND of the pressure and shadow/solar cell sensors further
processing is stopped. The early and reliable identification of an
input precludes the activation or consideration of another input in
this mutually exclusive electronic cluster key arrangement.
[0126] It is to be understood that the present invention is not
limited to the embodiments described above, but encompasses any and
all embodiments within the scope of the following claims.
* * * * *