Abstract: A latent image developer system and method is disclosed permitting the recovery of document impressions present in paper and other materials. The disclosed system utilizes two power supplies, a first power supply providing a plate bias charge which is applied to the document to be inspected, and a secondary power supply utilized to attract toner or other imaging powder attractant to the latent images present on the document to be inspected. The disclosed invention permits recovery of previously unrecoverable latent detail within documents as compared to the prior art which utilized a single power supply to promote toner to be attracted to the latent document images.

Abstract: An electro-mechanical electrostatic air cleaner that combines a low air resistance dielectric fibrous filter material positioned between and electrically charged by two electrically resistant carbon coated screens. The screens are charged by a remotely mounted bi-polar power supply. A pair of post ionization electrodes charge particles in the air with opposite charges, causing the particles to agglomerate. A plurality of screens may be placed in an array for increased one-pass filtration.

Abstract: An air ion emitter has a needle-like emitter coaxially mounted within a cylindrical barrel. The barrel is pivoted and rotatable on the base so that it can be pointed in any direction and angle, as at a collector at opposite plurality. The end of the barrel has venturi slots therein so that air flow induced by the emission of ions is radially inward and then axially out the end to scour the needle point and keep it sharp.