Touch activated controller and method
First Claim
1. In a touch sensitive circuit comprising an input adapted to be coupled to a sense line for supplying a change in capacitance via said input, an operational amplifier coupled to receive said change via said input, capacitance means coupled across said operational amplifier between the input and output thereof, comparator means coupled to said output of said operational amplifier, means for generating first and second signals at varying voltages normally plottable along substantially parallel traces, means for coupling said first and second signals respectively to supply signals to said operational amplifier and said comparator means to vary said output of said operational amplifier to be compared to said second signal to provide periodic cross-over between said first and second signals indicative of the presence of capacitance applied to the first named said input.
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Accused Products
Abstract
A touch activated controller generates UP/DOWN control signals in response to movement of a human finger (or other comparable contact) along a control surface thereof. The UP information is derived from movement of the finger in one direction and the DOWN information is derived from movement in a substantially opposite direction. This system generates a sequence of control signals in one or the other of the two directions. In addition, when the finger is removed from the device the output remains in its last previous state or condition existing before removing the finger. Thus, the logic of the system is sensitive substantially to motion and direction of movement so that the logic of the operation of the device closely resembles the motion of a thumbwheel control. Merely placing a finger on the surface of thumbwheel or on the surface of the disclosed device generates no change in the position of the thumbwheel or the output of the device herein. When a finger is moved in one direction while in contact with the control surface of the device or the thumbwheel the output of the device will generate control signals counting up or down depending on the direction of movement of the finger.
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Citations
1 Claim
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1. In a touch sensitive circuit comprising an input adapted to be coupled to a sense line for supplying a change in capacitance via said input, an operational amplifier coupled to receive said change via said input, capacitance means coupled across said operational amplifier between the input and output thereof, comparator means coupled to said output of said operational amplifier, means for generating first and second signals at varying voltages normally plottable along substantially parallel traces, means for coupling said first and second signals respectively to supply signals to said operational amplifier and said comparator means to vary said output of said operational amplifier to be compared to said second signal to provide periodic cross-over between said first and second signals indicative of the presence of capacitance applied to the first named said input.
Specification