Abstract: Disclosed is a printing plate, for an electrophotographic process, which comprises an electroconductive support and a photosensitive layer formed on the electroconductive support, in which the photosensitive layer is formed by incorporating (a) a trisazo pigment represented by the general formula (I) and (b) at least one member selected from perynone pigments and anthanthrone pigments as photoconductive substances and (c) at least one electron donor substance as a sensitizer in an alkali-soluble binder resin. This printing plate has a high sensitivity and a printing image having a high quality is formed on the printing plate without contamination of the non-image area due to the electrophotography, and prints having a high-quality image can be obtained by using this printing plate.

Abstract: Disclosed is an eluting solution for eluting a non-image area of an electrophotographic printing plate having a toner image formed and fixed thereon by electrophotography, to expose a hydrophilic substrate or a substrate that can be rendered hydrophilic. This eluting solution is an aqueous solution containing at least an alkali chelating agent.

Abstract: An exposure device for a platemaking apparatus has: a plate material feed unit consisting of a suction mechanism for feeding and stopping a plate material on an exposure unit, conveyor belts, drive motors and the like; two shielding curtains respectively rolled at two ends of the exposure unit and selectively extended on the exposure unit; shielding curtain drive units for independently driving the two shielding curtains; a setting unit for setting exposure conditions of a document image to be formed on the plate material; and a control unit for controlling the motors of the plate material feed unit and the shielding curtain drive units in a given relationship in response to the conditions set in the setting means, wherein an identical document image is formed on different positions of a single plate material a plurality of times.