Capacitance membrane switchcore with intertrace capacitive coupling and/or intratrace capacitive coupling
First Claim
1. A capacitance membrane switchcore for a keyboard having a plurality of operator actuatable key sites and including drive circuitry and sense circuitry to be connected to the switchcore, the capacitance membrane switchcore comprising (i) a dielectric layer, (ii) a conductive first circuit along a first surface of the dielectric layer that includes a plurality of conductive first traces and a plurality of first capacitor plates, (iii) a conductive second circuit along a second surface of the dielectric layer opposite from the first surface thereof that includes a plurality of conductive second traces and a plurality of second capacitor plates, and (iv) the first traces and the second traces are arranged relative to each other so as to define a matrix comprising a plurality of key cells, each including a fixed capacitor consisting of a first capacitor plate and a second capacitor plate that is unique to each key cell,the improvement wherein the capacitance membrane switchcore further includes:
- a conductive third circuit along the same surface of the dielectric layer as the first circuit and including a plurality of conductive third traces, there being one third trace for each second trace of the second circuit;
an intertrace coupling capacitor coupling each second trace of the second circuit to a selected third trace of the third circuit, there being one intertrace coupling capacitor for each second trace, each intertrace coupling capacitor including a capacitor plate along the same surface of said dielectric layer as the second circuit and a capacitor plate along the same surface of said dielectric layer as the third circuit; and
the first traces and third traces are arranged for connection to drive circuitry and sense circuitry of a keyboard.
5 Assignments
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Accused Products
Abstract
A capacitance membrane switchcore (12,12a, 12b, 12c, 12c'"'"') including a first circuit (16, 16'"'"'), a second circuit (17,17'"'"') and a third circuit (49,49'"'"') in which intertrace coupling capacitors (58,58'"'"') couple conductive traces (40-47,135) of the second circuit (17,17'"'"') to conductive traces (51,51'"'"') of the third circuit (49,49'"'"'). Also disclosed is a capacitance membrane switchcore (12) including a first circuit (16) having at least one trace (65) with a first branch (65a) along a first surface (18a ) of a dielectric layer (18), a second branch (65b) along a second surface (18b) of the dielectric layer (18), an intratrace coupling capacitor (66,67) coupling the first branch (65a) to the second branch (65b), a third branch (65c) along the first surface (18a) of the dielectric layer (18), and an intratrace coupling capacitor (68,69) coupling the second branch (65b) to the third branch (65c).
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Citations
39 Claims
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1. A capacitance membrane switchcore for a keyboard having a plurality of operator actuatable key sites and including drive circuitry and sense circuitry to be connected to the switchcore, the capacitance membrane switchcore comprising (i) a dielectric layer, (ii) a conductive first circuit along a first surface of the dielectric layer that includes a plurality of conductive first traces and a plurality of first capacitor plates, (iii) a conductive second circuit along a second surface of the dielectric layer opposite from the first surface thereof that includes a plurality of conductive second traces and a plurality of second capacitor plates, and (iv) the first traces and the second traces are arranged relative to each other so as to define a matrix comprising a plurality of key cells, each including a fixed capacitor consisting of a first capacitor plate and a second capacitor plate that is unique to each key cell,
the improvement wherein the capacitance membrane switchcore further includes: -
a conductive third circuit along the same surface of the dielectric layer as the first circuit and including a plurality of conductive third traces, there being one third trace for each second trace of the second circuit; an intertrace coupling capacitor coupling each second trace of the second circuit to a selected third trace of the third circuit, there being one intertrace coupling capacitor for each second trace, each intertrace coupling capacitor including a capacitor plate along the same surface of said dielectric layer as the second circuit and a capacitor plate along the same surface of said dielectric layer as the third circuit; and the first traces and third traces are arranged for connection to drive circuitry and sense circuitry of a keyboard. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A capacitance membrane switchcore for a keyboard having a plurality of operator actuatable key sites and including drive circuitry and sense circuitry to be connected to the switchcore, the capacitance membrane switchcore comprising (i) a dielectric layer, (ii) a conductive first circuit along a first surface of the dielectric layer that includes a plurality of conductive first traces and a plurality of first capacitor plates, (iii) a conductive second circuit along a second surface of the dielectric layer opposite from the first surface thereof that includes a plurality of conductive second traces and a plurality of second capacitor plates, and (iv) the first traces and the second traces are arranged relative to each other so as to define a matrix comprising a plurality of key cells, each including a fixed capacitor consisting of a first capacitor plate and a second capacitor plate that is unique to each key cell,
the improvement wherein the capacitance membrane switchcore further includes: - at least one trace of the first or second circuit that comprises
(1) a first branch along the one surface of the dielectric layer, (2) a second branch along the opposite surface of the dielectric layer, (3) an intratrace coupling capacitor coupling the first branch to the second branch, (4) a third branch along the said one surface of the dielectric layer, and (5) an intratrace coupling capacitor coupling the second branch to the third branch. - View Dependent Claims (22)
- at least one trace of the first or second circuit that comprises
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23. A capacitance membrane switchcore for a keyboard having a plurality of operator actuatable key sites and including drive circuitry and sense circuitry to be connected to the switchcore, the capacitance membrane switchcore comprising (i) a dielectric layer, (ii) a conductive first circuit along a first surface of the dielectric layer that includes a plurality of conductive first traces and a plurality of first capacitor plates, (iii) a conductive second circuit along a second surface of the dielectric layer opposite from the first surface thereof that includes a plurality of conductive second traces and a plurality of second capacitor plates, and (iv) the first traces and the second traces are arranged relative to each other so as to define a matrix comprising a plurality of key cells, each including a fixed capacitor consisting of a first capacitor plate and a second capacitor plate that is unique to each key cell,
the improvement wherein the capacitance membrane switchcore further includes: -
a conductive third circuit along the same surface of the dielectric layer as the first circuit and including a plurality of conductive third traces, there being one third trace for each second trace of the second circuit; an intertrace coupling capacitor coupling each second trace of the second circuit to a selected third trace of the third circuit, there being one intertrace coupling capacitor for each second trace, each intertrace coupling capacitor including a capacitor plate along the same surface of said dielectric layer as the second circuit and a capacitor plate along the same surface of said dielectric layer as the third circuit; and the first traces and third traces are arranged for connection to drive circuitry and sense circuitry of a keyboard; and the first circuit includes at least one first trace that comprises (1) a first branch along the first surface of the dielectric layer, (2) a second branch along the second surface of the dielectric layer, (3) an intratrace coupling capacitor coupling the first branch to the second branch, (4) a third branch along the first surface of the dielectric layer, and (5) an intratrace coupling capacitor coupling the second branch to the third branch. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
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35. A capacitance membrane switchcore for a keyboard having a plurality of operator actuatable key sites and including drive circuitry and sense circuitry to be connected to the switchcore, the capacitance membrane switchcore comprising (i) a dielectric layer, (ii) a conductive first circuit along a first surface of the dielectric layer that includes a plurality of conductive first traces, (iii) a conductive second circuit along a second surface of the dielectric layer opposite from the first surface thereof that includes a plurality of conductive second traces and a plurality of second capacitor plates, and (iv) the first traces and the second traces are arranged relative to each other so as to define a matrix comprising a plurality of key cells,
the improvement comprising: -
said first circuit including (i) a plurality of capacitor driven plates electrically connected to each first trace, there being one capacitor driven plate at each key cell of the matrix, and (ii) a plurality of first capacitor plates electrically independent of the capacitor driven plates, there being one first capacitor plate at each key cell of the matrix, and each first capacitor plate is registered with a selected second capacitor plate to provide a fixed capacitor that is unique to each key cell of the matrix; each operator actuatable key site includes a movable capacitor plate adapted to form a variable capacitor with the capacitor driven plate and the first capacitor plate at a key cell; a conductive third circuit along the same surface of the dielectric layer as the first circuit and including a plurality of conductive third traces, there being one third trace for each second trace of the second circuit; an intertrace coupling capacitor coupling each third trace to a second trace to capacitively couple each second trace of the second circuit to a selected third trace of the third circuit; and the first traces are arranged for connection to one of the drive circuitry and sense circuitry of a keyboard, and the third traces are arranged for connection to the other of the drive circuitry and sense circuitry of a keyboard. - View Dependent Claims (36, 37)
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38. In a capacitance membrane switchcore of the type including conductive first and second circuits including conductive traces along opposed surfaces of a dielectric layer, the circuits defining a matrix comprising a plurality of key cells and adapted for combining with a data entry keyboard including drive circuitry and sense circuitry,
the improvement wherein: the switchcore further includes (i) a conductive third circuit including conductive third traces along the same surface of said dielectric layer as one of the first and second circuits, and (ii) an intertrace coupling capacitor coupling each third trace with a selected one trace of the other of the first and second circuits, the intertrace coupling capacitor comprising capacitor plates along opposed surfaces of said dielectric layer.
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39. In a capacitance membrane switchcore of the type including conductive first and second circuits including conductive traces along opposed surfaces of a dielectric layer, the circuits defining a matrix comprising a plurality of key cells and adapted for combining with a data entry keyboard including drive circuitry and sense circuitry,
the improvement wherein: at least one conductive trace of the first and second circuits includes a first branch along one surface of the dielectric layer, a second branch along the opposite surface of the dielectric layer, a third branch along said one surface of the dielectric layer, and (i) a first intratrace coupling capacitor coupling the first branch to the second branch and (ii) a second intratrace coupling capacitor coupling the second branch to the third branch.
Specification