Abstract: Apparatus for forming an array of liquid streams which break up into small uniformly sized and spaced droplets. A cover plate is sealed to a base plate having grooves sized and spaced according to a predetermined pattern to define a plurality of nozzles. Manifold means are provided to supply liquid under pressure to the nozzles thus formed. In a preferred embodiment for ink-jet applications the nozzles, or manifold branches supplying the nozzles, are of such a configuration as to electrically isolate the liquid flowing therethrough and separate electrodes are provided for each nozzle. This makes it possible to use a common charging electrode for the array while exercising separate control over the droplet-forming streams.

Abstract: A heating zone of accurately controlled length and predetermined energy profile throughout its length is formed within a focusing apparatus. An elliptical cavity is provided having a conically-configured reflector positioned such that its longitudinal axis coincides with one of the focal axes of the elliptical cavity. An elongate body is placed within the cavity such that its longitudinal axis coincides with the other focal axis. When a beam of radiant energy within a wavelength range which couples with the body to heat it, e.g., a laser beam, is directed onto the conically-configured reflector it is concentrated uniformly around the body throughout a predetermined length. The energy profile along the zone length may be varied either by adjusting the energy distribution in the energy beam prior to being reflected, by modifying the surface contour of the reflector, by modifying the contour of the walls defining the elliptical cavity or by a combination of two or more of these techniques.

Abstract: A printing device for printing with drops of printing fluid, in which discrete droplets of a printing fluid are ejected from a printing element along a predetermined path to a recording surface. The printing element comprises a nozzle communicating with a printing fluid reservoir. A control electrode mounted on the nozzle is arranged to apply pressure pulses to printing fluid in the nozzle so as to eject discrete droplets of printing fluid from said nozzle.

Abstract: An optical scanner wherein the image of a straight line is focused by an optical element such as a concave mirror or converging lens on the arc of a circle which is scanned by a rotating drum having one or more field stops such as pin holes or optical fibers directing light upon a stationary photodetector. The optical center of the focussing element is disposed in the plane of the scanning circle; and the axis of rotation of the drum orthogonally intersects the plane at a point displaced from the optical center.