Abstract: An optical apparatus. More particularly, a laser sensitometer. The apparatus comprises: a polarized light source adapted to provide a Gaussian beam of light directed along an optical axis; a rotatable polarizer disposed in the optical axis adapted to vary an intensity of the beam of light, the polarizer being rotatable about the optical axis; and a rotatable polygon disposed in the optical axis, the polygon being rotatable about an axis perpendicular to the optical axis.

Abstract: An optical apparatus. More particularly, a laser sensitometer. The apparatus comprises: a polarized light source adapted to provide a Gaussian beam of light directed along an optical axis; a rotatable polarizer disposed in the optical axis adapted to vary an intensity of the beam of light, the polarizer being rotatable about the optical axis; and a rotatable polygon disposed in the optical axis, the polygon being rotatable about an axis perpendicular to the optical axis.

Abstract: An electrostatic spraying device in which liquid emerging from an outlet of the device nozzle (12) is subjected to an electrical field sufficiently high for the liquid to be drawn from the outlet as one or more ligaments which break up into charged droplets to form the spray. The device is adapted for the spraying of targets which are conventionally difficult to coat electrostatically, eg. targets of insulating material. This is achieved by the use of circuitry (18, 20, 22, 24) which generates a bi-polar high voltage output having a frequency such that successive clouds of particles are charged with opposite polarity but do not discharge each other in flight. In this way, the charge applied to the particles is effective to assist seeking of the target without leading to build-up of charge on the target.

Abstract: Radiant energy is directed from a source (14,16) to an illumination plane (28) where the light receiving ends of groups (36) of optic fibers are arranged in coplanar striations (100), after which the radiant energy passes through the groups of optic fibers into individual exposure columns (40) and on to an exposure plane (42) where a radiation sensitive sample is exposed in individual areas to different, readily adjustable levels of illuminance from each of the groups of optic fibers.