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A DEVELOPER APPARATUS Disclosure Number: IPCOM000023251D
Original Publication Date: 1977-Apr-30
Included in the Prior Art Database: 2004-Mar-29

Publishing Venue

Xerox Disclosure Journal


Developer unit 38, employed in an electrophotographic printing machine, deposits particles on a latent image recorded on belt 18 advancing in the direction of arrow 14. Developer unit 38 includes a housing 80 defining a chamber 82 having a supply of particles 84 therein. A rotating cylinder 86 advances par-ticles 84 from chamber 82 to development zone 88. Cylinder 86 has a plurality of holes extending in a radial direction from the outer surface to the inner surface thereof. Each hole is of a smaller diameter than the size of the smallest particle 84, preventing the particles from passing through the holes. A pressure differential is maintained by a blower 90 creating an inwardly directed air flow from the exterior circumferen-tial surface of cylinder 86 to the interior surface thereof through the holes therein. The inwardly directed pressure differential attracts particles 84 to the exterior circum-ferential surface of cylinder 86 as it rotates in the direc-tion of arrow 92 through the supply of particles 84 Blade 94, secured to housing 80, defines a gap between cylinder 86 and itself to regulate the thickness of the layer of particles adhering to cylinder 86. As cylinder 86 rotates in the direc-tion of arrow 92, particles 84 are advanced into development zone 88. A stationary interior member positioned opposed from development zone 88 and mounted interiorly of cylinder 86 seals the holes at development zone 88. This removes the vacuum force and allows the particles to be readily transfer-red from cylinder 86 to belt 18. An ultrasonic transducer 96