Pin charge coroton with optimum dimensions for minimum ozone production

A process cartridge for use in a printing machine comprising, said process cartridge including a charging apparatus for applying a uniform electrostatic charge to a charge retentive surface, said apparatus comprising:

• a housing;
• an array of pin electrodes supported by said housing and positioned adjacent said surface in a non-contact relationship;
• a generally U shaped shield connected to said housing and at least partially surrounding said array of pin electrodes;
• a grid positioned across distal ends of said shield, said grid defining an effective charge length and an effective grid width;
• and
• a power supply operatively coupled to said pin electrodes for supplying a predetermined current having a magnitude thereof to each of said pin electrode, said power supply providing a predetermined voltage having a magnitude thereof to said grid, at least one of the magnitude of said current, the magnitude of said voltage, the effective charge length and the effective grid width being selected so as to optimize charge uniformity, to minimize photoreceptor grid sensitivity, and to minimize ozone generated within said charging apparatus.

An electrophotographic printing machine of the type including a process cartridge having a charging apparatus for applying a uniform electrostatic charge to a charge retentive surface, said apparatus comprising:

• a housing;
• an array of pin electrodes supported by said housing and positioned adjacent said surface in a non-contact relationship;
• a generally U shaped shield connected to said housing and at least partially surrounding said array of pin electrodes;
• a grid positioned across distal ends of said shield, said grid defining an effective charge length and an effective grid width;
• and
• a power supply operatively coupled to said pin electrodes for supplying a predetermined current having a magnitude thereof to each of said pin electrode, said power supply providing a predetermined voltage having a magnitude thereof to said grid, at least one of the magnitude of said current, the magnitude of said voltage, the effective charge length and the effective grid width being selected so as to optimize charge uniformity, to minimize photoreceptor grid sensitivity, and to minimize ozone generated within said charging apparatus.