Compact keypad system and method

• US 5,612,690 A
• Filed: 06/03/1993
• Issued: 03/18/1997
• Est. Priority Date: 06/03/1993
• Status: Expired due to Term

• Current Assignee: Nuance Communications, Inc. (Microsoft Corporation)
• Original Assignee: David Levy
• Inventors: Levy, David
• Primary Examiner(s): MULLEN, THOMAS J
• Application Number:
  US08/071,242
• Time in Patent Office: 1,384 Days
• Field of Search: 341/22, 341/34, 345/168, 345/173, 200/5 A, 400/485, 364/709.15, 340/543, 340/426, 340/430
• US Class Current: 341/22
• CPC Class Codes: G06F 3/0202 Constructional details or processes of manufacture of the input device
• CPC Class Codes: G06F 3/0235 using chord techniques G06F3/0234 takes precedence
• CPC Class Codes: H01H 13/70 having a plurality of operating members associated with different sets of contacts, e.g. keyboard mounting together a plurality of independent switches H02B
• CPC Class Codes: H01H 13/84 characterised by ergonomic functions, e.g. for miniature keyboards; characterised by operational sensory functions, e.g. sound feedback legends H01H13/83
• CPC Class Codes: H01H 2217/018 Indication of switch sites
• CPC Class Codes: H01H 2217/024 Profile on actuator
• CPC Class Codes: H01H 2217/036 Plural multifunctional miniature keys for one symbol
• CPC Class Codes: H01H 2221/012 Joy stick type
• CPC Class Codes: H01H 2223/002 sealed
• CPC Class Codes: H01H 2223/0345 with keys positioned directly next to each other without an intermediate bezel or frame

Abstract

In a key pad key cap symbols are placed at the interstices between key caps as well as at their centers. The key pad electronics are designed to register simultaneously actuated key caps at an interstice as an input uniquely associated with the symbol locate at the interstice. The linear dimension of a row of key caps are approximately one-half that of a conventional key cap requiring approximately two key caps to form a linear dimension sizable enough to comfortably accommodate the tip of an adult finger. Additionally, the symbols located at the centers of key caps are elevated slightly, allowing unimpeded and ergonomic access to individual keys as well as the interstices.

Claims

1. A compact keypad system comprising:

a housing;

a plurality of key switch means disposed on said housing;

a contact surface coupled to said plurality of key switch means;

a plurality of first symbols disposed upon said contact surface, wherein each of said first symbols (i) graphically identifies an associated location on said contact surface, (ii) corresponds with an associated one of a plurality of unique output functions, and (iii) is approximately equidistant to the key switch means of an associated one of a plurality of subsets, each subset comprising at least two adjacent ones of said plurality of key switch means wherein at least one of the dimensions between adjacent ones of said plurality of key switch means is less than the width of the adult human finger; and

an electronic detection circuit sensing the simultaneous actuation of said plurality of key switch means in a subset and subsequently outputting a first signal corresponding to said unique output function associated with said subset and its associated first symbol.

2. The invention of claim 1 wherein said contact surface includes a plurality of key cap means with a contoured to surface such that a center portion of each key cap means is approximately 2-3 mm higher than an outer portion of that key cap means wherein each of the key cap means has disposed on said center portion an associated one of a plurality of second symbols, thereby identifying an output function uniquely associated with each one of said key cap means.

3. A method for miniaturizing the keys of a keypad such that the contact area of each key is smaller than the associated contact area of the adult human finger without compromising ergonomic efficiency comprising the steps of:

a) designing a top surface with a set of key caps to allocate a plurality of areas on said top surface for the placement of a corresponding plurality of graphic legends thereon such that each of the legends is readily associated with an associated one of a plurality of subsets of said key caps, wherein each subset comprises two or more key caps, wherein at least one of the dimensions of each of said key caps, as measured along said top surface, is less than the width of the adult human finger;

b) disposing upon each of said areas an associated one of said plurality of graphic legends, each of which designating an associated one of a plurality of unique functions associated with said subsets;

c) coupling key switch means beneath each of said key caps; and

d) generating a plurality of signals, each of said plurality of signals to be generated in response to the simultaneous pressing of the key caps of an associated one of said plurality of subsets of said key caps and the resulting actuation of at least an associated subgroup of key switch means, said subgroup consisting of any set of key switch means within a subset which uniquely identifies the associated subset from the remaining plurality of subsets.

4. The invention of claim 3 further comprising the steps of:

e) elevating a center portion of each key cap by approximately 2 to 3 millimeters; and

f) printing a central graphic legend on said center portion of each of said key caps, said central graphic legend indicating an operation associated with said key switch located directly beneath said central graphic legend.

5. A compact keypad system including:

a first plurality of contact surface areas, each one of said first plurality having an associated one of a plurality of legends, adjacent ones of said first plurality located at an approximate unit distance X from each other, said first plurality disposed proximate to a first reference plane;

a second plurality of contact surface areas, each one of said second plurality having an associated one of said plurality of legends, each one of said second plurality located at said approximate unit distance X from adjacent ones of said second plurality, said second plurality disposed proximate to a second reference plane, said second reference plane approximately parallel with said first reference plane,

wherein each one of said second plurality is disposed between ones of said first plurality such that each one of said second plurality is approximately equidistant to adjacent ones of said first plurality;

and said second reference plane is displaced from said first reference plane by approximately 2-3 mm, thereby providing comfortable and ergonomic access to each function of said compact keypad system.

6. The invention of claim 5 wherein said unit distance X is defined as approximately one-half the distance occupied by a standard dimension key cap, or approximately 10 mm, thereby providing comfortable and ergonomic access to approximately 2N-1 contact surface areas within said first plurality and approximately 2N contact surface areas within said second plurality, and hence a total of approximately 4N-1 different legends in a row of length equal to that of a row of N standard dimension contact surface areas of approximately 18 mm in width.

7. The invention of claim 6 wherein said first plurality of contact surface areas and said second plurality of contact surface areas are both disposed in a predominantly undulating surface contour that connects contact surface areas of said first plurality to contact surface areas of said second plurality.

8. A compact keypad for inputting data with a human finger, said keypad comprising:

a first key switch;

a second key switch;

a third key switch;

a fourth key switch;

a fifth key switch;

a sixth key switch, wherein said key switches are disposed in a matrix comprising two horizontal rows and three vertical rows, wherein the set of first, second, and third key switches are above and adjacent to the set of fourth, fifth, and sixth key switches and the set of first and fourth key switches are to the left of and adjacent to the set of second and fifth key switches and the third and sixth key switches are to the right of and adjacent to the set of second and fifth key switches, and wherein at least one of the dimensions between adjacent ones of said plurality of key switch means is less than the width of the adult human finger;

a first associated set consisting of the first, second, fourth, and fifth key switches;

a second associated set consisting of the second, third, fifth, and sixth key switches;

a first electrical signal corresponding to the actuation of any of a plurality of subsets of key switches of said first associated set which uniquely identify said first associated set;

a second electrical signal corresponding to the actuation of any of a plurality of subsets of key switches of said second associated set which uniquely identify said second associated set;

electronics to generate the first and second signals;

a plurality of key cap means wherein each of said key cap means is disposed above an associated one of said key switches;

a first legend, said first legend disposed on said key cap means approximately equidistant from said first, second, fourth and fifth switches; and

a second legend, said second legend disposed on said key cap means approximately equidistant from the second, third, fifth and sixth key switches.

9. The invention of claim 8 wherein each of said key cap means has a contoured shape such that a center portion is approximately 2-3 mm higher than an outer portion;

and

further including a central legend means located on said center portion of each of said key caps.