| 摘要 |
A method for amplifying an electrostatic, charge-differential pattern is disclosed. The method comprises (a) imagewise forming a first toner deposit by developing a first electrostatic pattern having a first charge differential per unit area whose maximum value is no greater than a preselected level, (b) in an image-amplification element comprising a charge-holding surface layer overlying a field-supporting electrode, forming a current-carrying path between the toner deposit and the field-supporting electrode, (c) under conditions in which nontoned regions are not photoexcited, overall charging the image-amplification element with sufficient charge to form an enhanced electrostatic charge pattern having a second charge differential per unit area whose maximum value is greater than the preselected value in step (a), and (d) developing the enhanced charge pattern into a second toner deposit. By this process, high-maximum-density, continuous-tone images can be produced wherein the maximum density of such images is obtained by amplification of initial charge differentials whose maximum value is, for example, 30 nanocoulombs/cm2 or lower. In addition, images can be produced with low contrast, i.e., obtained over a wide exposure range. |
