| 摘要 |
<p>Images are formed using first and second fluidized beds of non-magnetic toner having first and second, respective, single applicator rollers. A charge retentive surface such as a photoconductive belt is uniformly charged (e.g. by a corona device) to a predetermined voltage level, and at least first and second different, spaced, latent electrostatic images are formed on the surface at different locations (such as by a laser based output scanning device). The surface is then moved past the first applicator roller, and then the second applicator roller. The first fluidized bed and applicator roller are electrically biased at a first bias level effective so that the first image is developed by a non-magnetic toner transferred from the first applicator roller to the first image while development of the second image is precluded, and the second fluidized bed and second applicator roller are electrically biased at a second bias level effective so that the second image is developed by non-magnetic toner transferred from the second applicator roller to the second image while development of the first image is precluded. A negative bias may be applied to the first fluidized bed and a positive bias to the second fluidized bed, while the first and second rollers are positively biased at voltage levels at least 50 volts different. Black toner may be applied by the first fluidized bed, and colored toner by the second bed. A transfer roller may be used to transfer toner from each of the fluidized beds to its associated applicator roller.</p> |
