Eliminating triboelectrically generated background in an electrophotographically produced image

A method of reducing triboelectrically generated background development on a photoconductive image member bearing an electrostatic latent image pattern including background portions, the method comprising:

• (a) moving said image member through a development zone, the image member including a photoconductive element and a thin protective overcoat layer, the overcoat layer being between about 0.1 .mu.m and about 15 .mu.m in thickness and having between about 0.1% and about 10% by weight a substance that is ionic conducting substance containing an electronegative group, and the overcoat including a material selected from the group consisting of a sol-gel, a ceramer and a doped glass wherein the glass is doped with said ionic conducting substance, the latent electrostatic image pattern being formed on said overcoat layer:
• (b) transporting electrographic developer in a development station, the developer including hard magnetic carrier particles and electrically insulative toner particles, through said development zone in contacting developing relation with the electrostatic latent image pattern to develop the latent image pattern, the developer being transported through said zone in response to rotation of a series of alternating polarity magnets formed in a core which effects tumbling of said carrier in said development zone, the toner particles being tribocharged so that substantially all of the particles are negatively charged and the toner particles having a volume weighted diameter of less than 9 .mu.m;
• and
• wherein the electrostatic latent image pattern is positively charged and in step (b) the toner particles tribocharge the photoconductive image member to decrease positive voltages on the image member by between 5 volts and 100 volts.

A method of recording images on a photoconductive image member with reduced triboelectrically generated background development, the method comprising:

• (a) corona charging said image member with a uniform primary charge;
• (b) exposing the image member to form an electrostatic latent image pattern;
• (c) moving said image member through a development zone, the image member including a photoconductive element and a thin protective overcoat layer, the overcoat layer being between about 0.1 .mu.m and about 15 .mu.m in thickness and of a composition having between about 0.1% and about 10% by weight a substance that is an ionic conducting substance containing an electronegative group, the latent electrostatic image pattern being formed on said overcoat layer;
• (d) transporting electrographic developer in a development station, the developer including hard magnetic carrier particles and electrically insulative toner particles, through said development zone in contacting developing relation with the electrostatic latent image pattern to develop the latent image pattern, the developer being transported through said zone in response to rotation of a series of alternating polarity magnets formed in a core which effects tumbling of said carrier in said development zone, the toner particles being tribocharged so that substantially all of the particles are negatively charged and the toner particles having a volume weighted diameter of less than 9 m;
• and
• wherein the electrostatic latent image pattern is negatively charged and in step (d) the toner tribocharges the photoconductive image member to increase negative voltages on the imaged member by between -5 volts and -100 volts.

A method of recording images on a photoconductive image member with reduced triboelectrically generated background development, the method comprising;

• (a) corona charging said image member with a uniform primary charge;
• (b) exposing the image member to form an electrostatic latent image pattern;
• (c) moving said image member through a development zone, the overcoat layer, the overcoat layer being between about 0.1 .mu.m and 15 .mu.m in thickness and of a composition having between about 0.1% and about 10% by weight a substance that is an ionic conducting substance containing an electronegative group, the latent electrostatic image pattern being formed on said overcoat layer,
• (d) transporting electrogranhic developer in a development station, the developer including hard magnetic carrier particles and electrically insulative toner particles, through said development zone in contacting developing relation with the electrostatic latent image pattern to develop the latent image pattern, the developer being transported through said zone in response to rotation of a series of alternating polarity magnets formed in a core which effects tumbling of said carrier in said development zone, the toner particles being tribocharged so that substantially all of the particles are negatively charged and the toner particles having a volume weighted diameter of less than 9 .mu.m;
• and
• wherein the electrostatic latent image pattern is positively charged and the toner tribocharges the photoconductive image member to decrease positive voltages on the image member by between 5 volts and 100 volts.