Improved electronic keyboard

Claim 2

An electrical keyboard (10) of the type having a base (28), a flexible circuit (42) defining a plurality of switches (63) and a plurality of similar key means (22) for actuating the switches, characterized in that A. said base (28) comprises a surface having a plurality of faces (28a to 28c) at least one of which is oriented in a different plane from, but intersecting another of, said faces, B. the flexible circuit (42) is disposed on all of said surface faces (28a to 28c) at different levels, and C. said key means (22) are disposed as strips (92) in rows on the flexible circuit (42) and extends over all of said faces (28a to 28c).

Claim 3

The keyboard defined in claim 1 characterized in that the key means (22) actuating the switches (63) at different levels have substantially the same shape but are tilted differently by the base surface faces (28a to 28c).

Claim 4

An electronic keyboard including a base (28) and a flexible printed circuit (42) positioned on the base (28), characterized in that A. said circuit (42) defines a plurality of spaced-apart electric switches (63) arranged in one or more rows on the base (28), each switch (63) remaining open until the printed circuit (42) is depressed at the location of that switch (63), B. one or more similar spring strips (72) are positioned against the printed circuit (42), each said strip (72) extending along a row opposite a plurality of the switches (63) in each switch row on the base defined by the printed circuit (42), each spring strip (72) comprising a lengthwise series of spring members (72a) each of which actuates an underlying switch (63) in the underlying switch row when moved from a relaxed position to a stressed position, and each spring strip in each row being separate from the spring strips extending along adjacent rows on the base (28), C. one or more-similar key guide strips (92) are positioned opposite each row of spring strips (72) and mounted to the base (28a), each key guide strip defining a lengthwise series of key guides (92a) for movably mounting keys (22) opposite the underlying spring members (72a), and D. mounting means (36,108) mount each guide strip separately to the base so as to fix the positions relative to the base (28) of the key guide strips (92) and the spring strips (72) and printed circuit (42) portions in each row on the base (28); and E. a key (22) is movably mounted in at least one key guide (92a) so as to engage an underlying spring member (72a), each said key being supported in a first position by the engaged spring member (72a) when that member is in its relaxed position, each said key (22) being movable to a second position so as to move the engaged spring member (72a), to its said stressed position, said key guides (92a), spring strips (72), and keys (22) being interchangeably positionable and mountable to any of the switch rows on said base (28).

Claim 5

An electronic keyboard including a base (28) and a flexible printed circuit (42) positioned on the base (28), characterized in that A. said circuit (42) defines a plurality of spaced-apart electric switches (63) arranged in one or more rows on the base (28), each switch (63) remaining open until the printed circuit (42) is depressed at the location of that switch (63), B. one or more similar spring strips (72) are positioned against the printed circuit (42), each said strip (72) extending along a row opposite a plurality of the switches (63) in each switch row on the base defined by the printed circuit (42), each spring strip (72) comprising a lengthwise series of spring members (72a) each of which actuates an underlying switch (63) in the underlying switch row when moved from a relaxed position to a stressed position, and each spring strip in each row being separate from the spring strips extending along adjacent rows on the base (28), C. one or more-similar key guide strips (92) are positioned opposite each row of spring strips (72) and mounted to the base (28a), each key guide strip defining a lengthwise series of key guides (92a) for movably mounting keys (22) opposite the underlying spring members (72a), and D. mounting means (36,108) mount each guide strip separately to the base so as to fix the positions relative to the base (28) of the key guide strips (92) and the spring strips (72) and printed circuit (42) portions in each row on the base (28); and E. a key (22) is movably mounted in at least one key guide (92a) so as to engage an underlying spring member (72a), each said key being supported in a first position by the engaged spring member (72a) when that member is in its relaxed position, each said key (22) being movable to a second position so as to move the engaged spring member (72a), to its said stressed position, said key guides (92a), spring strips (72), and keys (22) being interchangeably positionable and mountable to any of the switch rows on said base (28).

Claim 6

The keyboard defined in claim 3 characterized in that A. the base (28) includes a ramp (28) whose ramp angle varies from to the rear of the base (28), and B. adjacent rows of spring strips (72) and key guide strips (92) are mounted to the base at different elevations on said base floor (28) so that one row of key guide strips (92) and keys (22) is oriented at a different angle from an adjacent row of key guide strips (92) and keys (22).

Claim 7

The keyboard defined in claim 3 wherein the printed circuit (42) is characterized by A. an electrically insulating substrate (132), and B. an electrically conductive coating (134), affixed to a face of the substrate (132) except along relatively narrow paths (138) which define said switches (63) and connections thereto, said coating (134) occupying the major portion of the substrate (132) face-so that the physical characteristics of said circuit (42) are determined primarily by the physical characteristics of the coating (134).

Claim 8

The keyboard defined in claim 3 characterized in that a single key (22S) is mounted to the key guide strip (92) at a plurality of key positions defined thereby so that a plurality of switches (63) are associated with said single key (22S).

Claim 9

The keyboard defined in claim 3 characterized in that different keys (22) are mounted to the key guide strip (92) at different key positions defined thereby so that each different key (22) is associated with a single switch.

Claim 10

The keyboard defined in claim 3 wherein the printed circuit is characterized by A. a flexible electrically insulating substrate, B. a first array of switch contacts formed on one face of the substrate, C. a second array of switch contacts formed on said face, the contacts in each array being positioned so that when the substrate is folded over on itself to form superimposed layers, the contacts in the two arrays are in register, and D. a flexible electrically insulating spacer sheet positioned between the substrate layers, said sheet having openings in register with each pair of contacts so that the contacts of each pair can touch when the printed circuit is depressed at the location of each of said contact pair.

Claim 11

The keyboard defined in claim 3 characterized in that each switch in each row of switches is offset along that row from the associated key which operates that switch.

Claim 12

The keyboard defined in claim 9 wherein each spring member is characterized by A. one end being anchored to the base opposite a key guide, B. its opposite end engaging the key mounted in an adjacent key guide in the same row, and C. a portion intermediate said ends being located opposite the associated switch which is actuated by that spring member.

Claim 13

The keyboard defined in claim 3 wherein each spring section is characterized by A. a pair of spaced-apart parallel side rails, the corresponding rails of all said members being connected together end to end, and B. a spring arm extending up from the pair of side rails, the arms of all of said spring members being spaced substantially parallel to one another.

Claim 14

The keyboard defined in claim 3 wherein the mounting means are characterized by A. a plurality of anchoring posts depending from each key guide strip, B. an array of registering holes in the base, printed circuit and each said spring strip, said holes being positioned to receive said posts, and C. means for retaining said posts in the holes in said base.

Claim 15

The keyboard defined in claim 3 characterized by A. first retaining means on each of said key guide strips, and B. second retaining means on each of said keys, said first and second retaining means coacting to movably retain said keys in their key guides.

Claim 16

The keyboard defined in claim 13 characterized in that A. said first retaining means comprise one or more openings formed in each key guide strip adjacent each key guide defined thereby, and B. the second retaining means comprise one or more elongated resilient clips depending from each said key, each said clip engaging in an opening adjacent the key guide in which said each key is movably mounted.

Claim 17

The keyboard defined in claim 3 characterized by A. first buffer means on each of said key guide strips, and B. second buffer means on each of said keys, said first and second buffer means coacting when each key is moved to its second position so as to buffer said movement of said each key.