Finger operable control device
First Claim
1. A finger operable control device comprising a sensor having a central electrically conductive plate, a first pair of electrically conductive plates on a first axis and spaced from opposite edges of the central plate to form a first pair of capacitors therewith having substantially equal capacitance, a second pair of electrically conductive plates on a second axis different from the first axis and spaced from opposite edges of the central plate to form a second pair of capacitors therewith having substantially equal capacitance, characterised in that opposite members of each pair of plates are driven by antiphase outputs of a quadrature-phase generator and the central plate is connected to a detector capable of sensing the magnitude and/or phase of the signal therefrom caused by capacitive imbalance induced by presence of either a finger or a finger-operable earthed object placed on or near the conductive plates when the finger or object is displaced laterally from the intersection of the two axes.
0 Assignments
0 Petitions
Accused Products
Abstract
A finger operable control device that includes a sensor having five conductive plates. The conductive plates are coupled to a detector circuit arranged to sense capacity imbalance due to the presence of a finger or an earthed object on or by one or more of the conductive plates. The device is utilized as a mouse or joystick.
-
Citations
15 Claims
- 1. A finger operable control device comprising a sensor having a central electrically conductive plate, a first pair of electrically conductive plates on a first axis and spaced from opposite edges of the central plate to form a first pair of capacitors therewith having substantially equal capacitance, a second pair of electrically conductive plates on a second axis different from the first axis and spaced from opposite edges of the central plate to form a second pair of capacitors therewith having substantially equal capacitance, characterised in that opposite members of each pair of plates are driven by antiphase outputs of a quadrature-phase generator and the central plate is connected to a detector capable of sensing the magnitude and/or phase of the signal therefrom caused by capacitive imbalance induced by presence of either a finger or a finger-operable earthed object placed on or near the conductive plates when the finger or object is displaced laterally from the intersection of the two axes.
Specification