AC CORONA CHARGER FOR ELECTROSTATIC GRAPHIC COPYING APPARATUS

PROBLEM TO BE SOLVED: To uniformly electrostatically charge dielectric members moving along a travel pass operatively associated with a corona charger by using specific irregularly arrayed grids. SOLUTION: A variable load cycle AC charger 10 has corona wires 12, grids 14 and a shell 16. The grids 14 has plural grid elements arranged in a direction crossing the moving direction (arrow 36) of the dielectric member 20 and the spacings between the grid elements decrease substantially with respect to the moving direction (arrow 36) of the dielectric member 20. For example, the width of the grid elements (fine members) are 0.025 cm in an in-track direction. The grids 14 are in-tracks of nearly 6.1 cm in width and are divided to nearly equal three sections A to C. The in-track spacings between the respective fine members are 0.2 cm in the upstream section A, 0.13 cm in the central section B and 0.05 cm in the downstream section C.