Abstract: A mass storage device includes a media sheet supported on a substrate for storing digital data bit manifestations and a planar, integrated array of transducers arranged in rows and columns. The array is mounted in registration with the substrate, and its columns of transducers are oriented at an acute angle with respect to a movement axis. A piezoelectric device provides relative movement between the substrate and the array of transducers along the movement axis. Circuitry accesses rows of transducers in each column in a timed manner, so as to operate each transducer in a column at the time the transducer is adjacent a row of stored digital data in the media sheet. The acute angular relationship between the transducer array and the movement axis enables digital data to be stored in the media sheet in a fraction of the surface area occupied by an individual transducer and its associated circuitry.

Abstract: One or more magnetic fields having non-uniform gradients is periodically applied to a magnetic liquid stream, which is preferably isotropic and virtually free of remanence, to create perturbations in the stream so as to form droplets therefrom with substantially uniform spacing and of substantially uniform size. If more than one of the magnetic fields is applied, the maximum strength of each field is spaced an integral multiple wave length from the maximum strength of the adjacent magnetic field with each magnetic field having substantially the same maximum strength. The wave length of the perturbation is preferably between 4d and 8d where d is the diameter of the stream.

Abstract: A plurality of magnetic liquid streams is simultaneously excited to produce a plurality of streams of magnetic droplets of substantially uniform spacing and substantially uniform velocity. Each of the droplets in each of the streams passes over a separate selector for each stream to determine whether the droplet will be utilized for printing on a paper. A predetermined number of the droplets of each of the streams is subjected to a time periodic deflection to cause a first half of the predetermined number of droplets, which have been selected for printing by the selectors, to engage a paper in a first line and a second half to engage the paper in a second line. A ramp voltage deflection is separately applied to the predetermined number of droplets of each stream subjected to each half of the time periodic deflection to cause the print lines of the droplets to be orthogonal to the direction of movement of the paper.