Abstract: A display apparatus may be constructed by imparting motion to the light from a small light source to give the appearance of a line, causing the light to be "off" and "on" as desired during traverse of a line length, using as many light sources as needed for a two-dimensional display and precorrecting the light timing to compensate for the apparent change in movement rate during the motion.

Abstract: A silicon body has an array of nozzles therein and a separate magnet for each nozzle integral with the body. The magnet is disposed adjacent the nozzle with which it cooperates so that it can apply a deflection, prior to break-up of the stream exiting from the nozzle into droplets, to selected portions of the stream. The droplets, which are formed from the selected portions having the magnetic deflection applied thereto from the magnet cooperating with the nozzle, deflect to a gutter and are not applied to a recording surface, which moves orthogonal to the nozzles. If desired, the winding of the magnet can have a second excitation frequency supplied thereto to break up the stream into droplets. The break-up of the stream into droplets also can be accomplished by vibrations produced by a piezoelectric transducer, for example.

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.

Abstract: A scanner transfers information in the form of magnetic characters to a soft magnetic film, and subsequently transfers the information to a storage medium, such as disc, tape, or the like. Use of amorphous and other bubble material is suggested. A bias field is coupled through the magnetic characters to the material in which bubbles are generated and transported.

Abstract: A stream of magnetic ink droplets is directed towards a recording surface and initially passes through a selector, which selects the droplets for application to the recording surface to form characters thereon. Each of the selected droplets passes through first and second magnetic deflectors in which each of the selected droplets is deflected in directions orthogonal to each other and orthogonal to the direction in which the droplets are moving toward the recording surface. Each of the selected droplets is subjected to a magnetic field gradient varying with respect to time during the passage of the droplet through one or both of the magnetic fields depending on the desired position of the droplet on the recording surface relative to the prior droplet.