PIEZOELECTRIC FILM SONIC EMITTER

• Main Authors: KHURI-YAKUB, PIERRE, NORRIS, JOSEPH, O, CROFT, JAMES, J., III, SELFRIDGE, ALAN, ROBERT
• Format: Patent
• Language: English; French; German
• Published: 21.05.2008
• Subjects: ACOUSTICS; ACOUSTICS NOT OTHERWISE PROVIDED FOR; DEAF-AID SETS; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; FOR PERFORMING MECHANICAL WORK IN GENERAL; GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL; LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKEACOUSTIC ELECTROMECHANICAL TRANSDUCERS; METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICALVIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING,NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; MUSICAL INSTRUMENTS; PERFORMING OPERATIONS; PHYSICS; PUBLIC ADDRESS SYSTEMS; SOUND-PRODUCING DEVICES; TRANSPORTING

A speaker device for emitting subsonic, sonic or ultrasonic compression waves comprising a generally hollow drum, a rigid emitter plate (108) attached to the drum (100), and a plurality of apertures (112) formed within the plate which are covered by a thin piezoelectric film disposed across the emitter plate (108). A pressure source is coupled to the drum (100) for developing a biasing pressure with respect to the thin film (104) at the apertures (112) to distend the film (104) into an arcuate emitter configuration capable of constricting and extending in response to variations in the applied electrical input at the piezoelectric film (104) to thereby create a compression wave in a surronding environment. Parametric ultrasonic frequency input is supplied to the piezoelectric film (104) to propagate multiple ultrasonic frequencies having a difference component corresponding to the desired subsonic, sonic or ultrasonic frequency range.