Abstract: A reproduction apparatus imaging material dispensing system has a replaceable and rotatable imaging material dispensing container from which an at least partially magnetically aitractable consumable imaging material is dispensed. There is an optical imaging material level sensing system mounted outside of the container for optically detecting the imaging material inside the container through translucent walls thereof and signaling an insufficient remaining quantity of imaging material. A magnetic brush cleaning system internally cleans imaging material from the inside of a annular translucent wall area of the container to provide and maintain relatively unobstructed such optical sensing. It can be provided by a stationary magnet mounted outside of but adjacent to the container to attract magnetically attractable imaging material to the inside of the container wall to form a magnetic cleaning brush to clean the translucent wall annular area.

Abstract: An apparatus for sealing a housing to prevent the escape of airborne material therefrom. Carrier beads are captured and suspended in a magnetic field extending across a region adapted to be sealed, forming a curtain of carrier beads for preventing the escape of airborne material, including toner particles, therepast. The carrier bead curtain is continuously collapsed and regenerated as carrier beads are captured, accumulated, and deposited into the housing.