公开(公告)号：CA1124794A

公开(公告)日：1982-06-01

申请号：CA321417

申请日：1979-02-13

Applicant: IBM

Inventor： JUSTUS DENNIS J ,  SMITH GERALD L

IPC: G03G15/02 ,  G01R27/00

Abstract: Method and apparatus for enabling measurement of corona drum current in an electrostatic copier as a maintenance aid. A rotatable drum supports a photoconductor with a conductive backing connected to a ground current return path including a slip ring. In the maintenance mode, the ground path is opened allowing drum current to flow through a current measuring circult including a pair of jacks to which a measurement device may be connected. The current measuring circuit also develops a potential which is representative of whether or not the current return path is grounded. This potential is coupled to a monitoring device where it may be used to drive a display. A method of aligning a corona generator employing the corona current measuring apparatus of the invention is applicable for aligning corona generators in situ in an electrostatic copier. The alignment method includes steps of energizing a selected corona generator, interrupting the normal ground return path, providing a current path from the photoconductor and coupling the current path to a measurement device. For alignment purposes at least two measurements are made, each measurement is made while different portions of the corona generator are masked. The measurements provide a measure of the corona current generated by two different portions of the generator which is useful in aligning the generator.