Stroke coded keyboard switch assembly

Claim 2

A keyboard having a plurality of keys indicative of a plurality of characters comprising a substrate having first conductors thereon, an insulating spacer positioned on said substrate and having openings therethrough, and a deformable membrane positioned on said spacer and adapted for movement through said openings, said membrane having second conductors thereon, characterized in that: each of said characters is defined by signals generated by connections of a plurality of said first conductors with a plurality of said second conductors in a specified sequence; and said keyboard includes means responsive to a pressure stroke in a first direction applied across one of said keys for establishing said connections in a first one of said specified sequences and for generating said signals indicative of a first one of said characters.

Claim 3

Apparatus in accordance with claim 1 wherein said first conductors comprise n unique conductors, said second conductors comprise m unique conductors, and said character is defined by said signals generated by said specified sequence of connections of i pairs of said first and second conductors so that (nm)i distinct characters can be defined on said keyboard by n+m unique conductors, where n and m are any positive integers greater than one and i is any positive integer greater than one and less than or equal to nm.

Claim 4

Apparatus in accordance with claim 2 where n and m each equal four and i equals two whereby 256 distinct characters can be defined on said keyboard by eight unique conductors.

Claim 5

Apparatus in accordance with claim 1 wherein said responsive means comprises: a plurality of first contact members within designated switching areas on said substrate, said first contact members within each of said switching areas being connected to a respective one of said plurality of first conductors; and a plurality of second contact members within areas defined by said keys on said membrane corresponding to said switching areas, said second contact members within each of said defined areas being connected to a respective one of said plurality of second conductors, said first and second contact members being arranged for sequential connection of respective ones thereof in response to said pressure strOke.

Claim 6

Apparatus in accordance with claim 1 wherein said one of said keys is indicative of a plurality of said characters and said responsive means is responsive to a pressure stroke applied across said one of said keys in a second direction for establishing said connections in a second one of said specified sequences and for generating said signals indicative of a second one of said characters.

Claim 7

Appparatus for generating encoded electrical signals comprising, in combination: a keyboard structure having a plurality of keys indicative of a plurality of characters; first and second groups of conductors, a plurality of said first and second groups of conductors being associated with one of said keys; and means responsive to a pressure stroke applied across said one of said keys in a first direction for connecting said plurality of said first group of conductors to said plurality of said second group of conductors in a first sequential order and for generating signals indicative of a first one of said characters.

Claim 8

Appparatus for generating encoded electrical signals comprising, in combination: a keyboard structure having a plurality of keys indicative of a plurality of characters; first and second groups of conductors, a plurality of said first and second groups of conductors being associated with one of said keys; and means responsive to a pressure stroke applied across said one of said keys in a first direction for connecting said plurality of said first group of conductors to said plurality of said second group of conductors in a first sequential order and for generating signals indicative of a first one of said characters.

Claim 9

Apparatus in accordance with claim 6 including means for grouping said signals into said first sequential order representing the keying of said first one of said characters so that errors in said keying can be reduced, comprising: first means for designating the first of said signals as the first signal in said first sequential order; first timing means for initiating a first timing period upon the completion of said first signal; second means for designating the second of said signals as the second signal in said first sequential order when said second of said signals is received before the expiration of said first timing period, said second designating means being responsive to said first timing means to reject said second of said signals and to initialize said first designating means by removing said first signal therefrom when said first timing period expires before said second of said signals is received so that signals caused by inadvertent touching of said keys can be eliminated.

Claim 10

Apparatus in accordance with claim 7 wherein said first timing period has a duration adapted to cause rejection of signals produced by discrete pokes on said keys and to cause signals produced by strokes on said keys to be designated as signals in said first sequential order.

Claim 11

Apparatus in accordance with claim 7 including a second timing means for initiating a second timing period when said second of said signals is received before the expiration of said first timing period; and third means for repeatedly designating said first and second of said signals as said first and second signals, respectively, in respective ones of said first sequential orders when said second of said signals has a duration greater than said second timing period, said third designating means being responsive to the termination of said second of said signals to cease operation whereby automatic repeat keying of said first one of said characters can be obtained.

Claim 12

Apparatus in accordance with claim 7 including a third timing means responsive to the termination of said second of said signals for initiating a third timing period; and means for rejecting subsequent ones of said signals until the expiration of said third timing period thereby to eliminate signals caused by keying strokes extending beyond said one of said keys.

Claim 13

Apparatus in accordance with claim 10 including means for reinitiating said third timing period when any signal subsequent to said second of said signals is received before the expiration of said third timing period.

Claim 14

Apparatus in accordance with claim 6 wherein said one of said keys is indicative of a plurality of said characters and said responsive means is responsive to a pressure stroke applied across said one of said keys in a second direction for connecting said plurality of said first group of conductors to said plurality of said second group of conductors in a second sequential order and for generating sigNals indicative of a second one of said characters.

Claim 15

Apparatus in accordance with claim 6 wherein said responsive means comprises a group of switches, a plurality of said switches being operably associated with one of said keys, a pair of said conductors from said first and second groups being associated with each of said switches for establishing a connection therebetween, said switches being arranged for operation in a first sequence in response to said pressure stroke in said first direction for connecting said conductors in said first sequential order.

Claim 16

Apparatus in accordance with claim 13 including: means for suppressing spurious signals caused by contact bounce when said switches are operated, said suppressing means including an integration circuit; and means for controlling the duration and spacing of signals generated when said switches are operated.

Claim 17

A keyboard each character of which is keyed by a pressure stroke in a specified direction within an area designated by said character on the surface of said keyboard to produce a preselected sequence of signals in an output circuit representing said character, comprising, in combination: a substrate having thereon a plurality of first contact members located in switching areas corresponding to said designated areas, and a plurality of first conductors each of which is connected to preselected ones of said first contact members; an insulating spacer mounted on said substrate and having apertures therein aligned with said first contact members; a resilient membrane mounted on said spacer and forming said surface of said keyboard and having said characters designated thereon, said membrane having on a major surface thereof a plurality of second contact members within said designated areas, said second contact members within a designated area being aligned with corresponding ones of said first contact members in a respective one of said switching areas through said apertures, and a plurality of second conductors each of which is connected to preselected ones of said second contact members, one of said signals being produced when one of said first conductors is connected to one of said second conductors, said membrane being adapted for movement through said apertures in response to said pressure stroke to connect said plurality of second contact members within said designated area with said corresponding ones of said first contact members within said respective switching area for connecting respective ones of said first conductors to respective ones of said second conductors, said first and second contact members being arranged for sequential connection to produce said preselected sequence of signals.

Claim 18

A keyboard each character of which is keyed by a pressure stroke in a specified direction within an area designated by said character on the surface of said keyboard to produce a preselected sequence of signals in an output circuit representing said character, comprising, in combination: a substrate having thereon a plurality of first contact members located in switching areas corresponding to said designated areas, and a plurality of first conductors each of which is connected to preselected ones of said first contact members; an insulating spacer mounted on said substrate and having apertures therein aligned with said first contact members; a resilient membrane mounted on said spacer and forming said surface of said keyboard and having said characters designated thereon, said membrane having on a major surface thereof a plurality of second contact members within said designated areas, said second contact members within a designated area being aligned with corresponding ones of said first contact members in a respective one of said switching areas through said apertures, and a plurality of second conductors each of which is connected to preselected ones of said second contact members, one of said signals being produced when one of said first conductors is connected to one of said second conductors, said membrane being adapted for movement through said apertures in response to said pressure stroke to connect said plurality of second contact members within said designated area with said corresponding ones of said first contact members within said respective switching area for connecting respective ones of said first conductors to respective ones of said second conductors, said first and second contact members being arranged for sequential connection to produce said preselected sequence of signals.

Claim 19

A keyboard each character of which is keyed by a pressure stroke within an area defined by said character on the surface of said keyboard, said character being represented by signals generated by the connection of two first conductors with two second conductors in a specified sequence by said pressure stroke, comprising, in combination: a substrate having thereon a plurality of said first conductors and a plurality of first contact members, first and second ones of said first contact members being respectively located within first and second portions of respective switching areas designated on said substrate, first and second ones of said first conductors being respectively connected to said first and second ones of said first contact members within said first and second portions of said switching area; a spacer on said substrate having openings therethrough aligned with respective ones of said first contact members; and a deformable membrane comprising said surface of said keyboard and having said defined areas thereon, said membrane having thereon a plurality of second contact members and a plurality of said second conductors, first and second ones of said second contact members being respectively located within first and second portions of said defined area, said firSt and second ones of said second contact members in said first and second portions of said defined area being respectively aligned through said openings with said first and second ones of said first contact members in said first and second portions of a corresponding one of said switching areas, first and second ones of said second conductors being respectively connected to said first and second ones of said second contact members within said first and second portions of said defined area, said membrane being adapted for movement through said openings in response to said pressure stroke to effect contact between said first and second ones of said second contact members within said defined area and said respective first and second ones of said first contact members within said corresponding switching area in a sequential order thereby connecting said first and second ones of said first conductors, respectively, to said first and second ones of said second conductors in said specified sequence to represent said character.

Claim 20

A keyboard each character of which is keyed by a pressure stroke within an area defined by said character on the surface of said keyboard, said character being represented by signals generated by the connection of two first conductors with two second conductors in a specified sequence by said pressure stroke, comprising, in combination: a substrate having thereon a plurality of said first conductors and a plurality of first contact members, first and second ones of said first contact members being respectively located within first and second portions of respective switching areas designated on said substrate, first and second ones of said first conductors being respectively connected to said first and second ones of said first contact members within said first and second portions of said switching area; a spacer on said substrate having openings therethrough aligned with respective ones of said first contact members; and a deformable membrane comprising said surface of said keyboard and having said defined areas thereon, said membrane having thereon a plurality of second contact members and a plurality of said second conductors, first and second ones of said second contact members being respectively located within first and second portions of said defined area, said firSt and second ones of said second contact members in said first and second portions of said defined area being respectively aligned through said openings with said first and second ones of said first contact members in said first and second portions of a corresponding one of said switching areas, first and second ones of said second conductors being respectively connected to said first and second ones of said second contact members within said first and second portions of said defined area, said membrane being adapted for movement through said openings in response to said pressure stroke to effect contact between said first and second ones of said second contact members within said defined area and said respective first and second ones of said first contact members within said corresponding switching area in a sequential order thereby connecting said first and second ones of said first conductors, respectively, to said first and second ones of said second conductors in said specified sequence to represent said character.