Patent ID: 6473075
Filing Date: 2002-10-29
Classification: G06F

Abstract:
A touchscreen system, comprising:a touchscreen substrate, said substrate capable of propagating acoustic waves; at least one transmitting transducer coupled to said substrate, said transmitting transducer initiating an acoustic wave of a first burst length in response to an input signal; a reflective array comprised of a plurality of acoustic wave reflectors coupled to said substrate, said reflective array stretching said first burst length to form a second burst length acoustic wave; at least one receiving transducer coupled to said substrate, said receiving transducer receiving said acoustic wave of said second burst length; and an adaptive controller coupled to said at least one transmitting transducer and to said at least one receiving transducer, said adaptive controller comprising: a reference oscillator generating a first frequency; a microprocessor coupled to said reference oscillator; a digital burst circuit coupled to said microprocessor, said reference oscillator, and to said at least one transmitting transducer, said digital burst circuit outputting said input signal to said at least one transmitting transducer in response to a burst control signal; and a memory coupled to said microprocessor, said memory containing a set of frequency correction values, wherein said microprocessor receives the first frequency and correction instructions regarding a desired center frequency from the memory based upon the set of frequency correction values and generates and outputs said burst control signal to said digital burst circuit based upon the correction instructions.