| 摘要 |
PURPOSE:To develop stably without fog and by a development of once a composite latent image consisting of two latent images by an original of a different kind formed by the upper and lower potentials centering around the reference potential on the same charge holding member, by use of a developer consisting of a high resistance magnetic one component toner of the same composition. CONSTITUTION:A positive electrostatic latent image 18 by a high potential and a negative electrostatic latent image 20 by a low potential are synthesized centering around the reference potential (for instance, zero potential). A composite electrostatic latent image obtained in this way is developed by applying the developing bias voltage being almost equal to the reference potential, by use of a developer consisting of a high resistance magnetic one component toner of the same composition charged to positive and negative in advance. As a result, the toner charged to positive and negative is adsorbed to each latent image, respectively, which offers the opposite polarity against the charging polarity of the toner, and the composite latent image is developed by a development of once. Also, if a weak charged toner and an uncharged toner exist, these toners are collected in a state that they are absorbed by a magnetic carrying means by its magnetism, therefore, generation of fog in a non-picture part can be prevented. |
