초록 ▼

A system and method for applying electrically charged non-magnetic toner to an image device, and subsequently to a moving substrate, provides precise level control, proper control of the electrical charge of the toner, minimization of dusting problems, and maximum evenness of the toner layer. First

A system and method for applying electrically charged non-magnetic toner to an image device, and subsequently to a moving substrate, provides precise level control, proper control of the electrical charge of the toner, minimization of dusting problems, and maximum evenness of the toner layer. First and second fluidized toner beds have the toner in them charged using corona sources. The second bed maintains a level of toner above the level in the first bed, and a spillway-defining restraining dam is disposed between the beds so that the toner above the level desired in the second bed spills over the restraining dam into the first bed, allowing very precise control of the level of toner in the second bed. Toner transfer mechanisms (such as rotating conductive cylinders) transfer toner from the first bed to the second bed, and from the second bed to the image device. Scrapers scrape excess toner from the rotating cylinders so that it falls back into either the first or second bed.

대표청구항 ▼

[ What is claimed is:] [1.]1. A system for applying electrically charged non-magnetic toner to an image device, comprising:a first fluidized toner bed having electrically charged non-magnetic toner maintained at substantially a first level therein;a first corona source disposed in said first bed for

[ What is claimed is:] [1.]1. A system for applying electrically charged non-magnetic toner to an image device, comprising:a first fluidized toner bed having electrically charged non-magnetic toner maintained at substantially a first level therein;a first corona source disposed in said first bed for electrically charging toner in said first bed;a second fluidized toner bed adjacent said first bed and having toner maintained at substantially a second level therein, different than said first level;a second corona source disposed in said second bed for electrically charging toner in said second bed;an image device;a first toner transfer mechanism maintained at a first electrical bias for transferring toner from said first bed to said second bed; anda second toner transfer mechanism maintained at a second electrical bias different than said first bias for transferring toner from said second bed to said image device, said image device maintained at a third electrical bias different than said first and second biases.