Pressure sensitive security system for tracking motion over a surface

Abstract

An alarm system uses an area sensor having a piezoelectric film sensitive to changes in pressure. A piezoelectric film with electrodes deposited on opposite surfaces of the film converts changes in mechanical pressure to electrical signals. A signal processor detects the electrical signals and generates an output signal in response. The electrodes could comprise single metalized sheets deposited on each surface. Alternatively, an array or pattern of individually operative electrodes could be provided. An array or pattern of electrodes enables the signal processor to determine the location, motion, and direction of motion of a force generating pressure changes on the piezoelectric film. The alarm system may include a threshold detector sensitive to the magnitude of pressure changes so that an output signal will not be generated unless the pressure change is sufficiently great. This invention is suitable as a floor covering for detecting an intruder walking over its surface.

Dependencies are inferred from the claim text.