Abstract: An acoustic imaging system coupled to an acoustic imaging medium to define an imaging surface. The acoustic imaging system includes an array of piezoelectric acoustic transducers formed at least in part from a thin-film piezoelectric material, such as PVDF. The array is coupled to the acoustic imaging medium opposite the imaging surface and formed using a thin-film manufacturing process over an application-specific integrated circuit that, in turn, is configured to leverage the array of piezoelectric actuators to generate an image of an object at least partially wetting to the imaging surface.

Abstract: An acoustic imaging system coupled to a sensing plate to define an imaging surface. The acoustic imaging system includes an array of piezoelectric acoustic transducers coupled to the sensing plate opposite the imaging surface and formed using a thin-film manufacturing process over an application-specific integrated circuit that, in turn, is configured to leverage the array of piezoelectric actuators to generate an image of an object at least partially wetting to the imaging surface.

Abstract: In crystal growing apparatus in which a crystal is vertically pulled from an electric heated melt the weight of the crystal is measured by a load cell whose output is compared with an expected function to form a control loop for controlling heater power, the improvement comprises a correction circuit for applying to the control loop a signal compensating for a time differential (.lambda.a) of an error signal in the load cell output. The correction circuit may be a feedback or a feed forward loop.