| 摘要 |
A system for developing a latent electrostatic image pattern formed on a coated photoconductive paper and which utilizes a nonconductive transfer cylinder that encloses a rotating cylindrical magnet. The magnet produces a longitudinally uniform magnetic field at the outer surface of the cylinder that draws a polarized, magnetically attractable, one component toner material over the outer surface of the transfer cylinder from a toner supply means to a deposit zone over the paper. A roller, plate, or other suitable unit under the paper supports the paper with a uniform, preselected minimum spacing between the transfer cylinder and the electrostatic image pattern on the paper. In the deposit zone electrostatic forces and gravitational forces urging the toner material from the transfer cylinder to the paper exceed the magnetic forces holding the toner on the transfer cylinder causing the toner to deposit selectively in the image areas. In one form, nonconductive support members for the magnet, the transfer cylinder and the paper support roller or other spacing control device cooperate with the nonconductive material forming or coating the transfer cylinder in blocking an electrical flow between the paper and the transfer cylinder.
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