DIRECT PRINTING DEVICE

摘要

An electrostatic image forming apparatus in which computer generated image information is converted into a pattern of electrostatic fields, includes a particle source including a particle carrier (33) which holds a layer of electrically charged particles that are transported toward a back electrode (12) through a printhead structure (5). The particle source may include a number of elements in contact with the toner layer which serve to regulate the charge and thickness of the layer as well as the position of the carrier relative to the printhead structure. Friction between these contact elements and the toner layer generates heat which causes minute quantities of particle to melt and become sticky, which can cause a film to build up on the contact elements and may eventually lead to the destruction of the toner layer. This problem is alleviated by associating a cooling arrangement with the toner particle source to effect cooling of the toner layer.