Apparatus and method of reducing charge roller contamination
View Patent ↗The present invention relates generally to image forming equipment, e.g. a laser printer of the type which includes a photoconductive (PC) drum and an associated charge roller. The invention is disclosed in exemplary embodiment as a laser printer incorporating a cleaner element with an electrical potential to sufficiently charge contamination particles on the PC drum to electrically repel from a charged surface, such as the charge roller.
1. A device for reducing the buildup of particulate contamination on the surface of a charging element within an image forming apparatus, the device comprising:
a photoconductive element having a surface, wherein said surface of said photoconductive element has a charged and discharged state;
a charging element positioned against the photoconductive element,
a conductive cleaner element for said photoconductive element, said conductive cleaner element having a portion positioned adjacent said surface of said photoconductive element;
wherein said cleaner element is supplied with an electrical potential and wherein said particulate assumes an electrical potential from said cleaner element;
wherein the surface of said photoconductive element when charged has a first voltage level of V 1 and when the photoconductive element is discharged the surface has a second voltage level of V 2 , and wherein said electrical potential provides a voltage V 3 for the cleaning element such that V 1 ≧V 3 ≧V 2 .
2. The device of claim 1 wherein V 3 is about 600 volts DC.
3. The device of claim 1 , wherein said conductive cleaner element comprises a conductive polymer.
4. The device of claim 3 , wherein said conductive polymer is a urethane.
5. The device of claim 1 , wherein said particulate assumes a negative charge.
6. The device of claim 1 , wherein said photoconductive element is a photoconductive drum.
7. A method for reducing the buildup of particulate contamination on the surface of a charging element in an image forming apparatus, said method comprising:
(a) providing a photoconductive element having a surface containing particulate and a charging element for said photoconductive element;
(b) providing a conductive cleaner element for said photoconductive element, said conductive cleaner element positioned adjacent said surface of said photoconductive element; and
(c) charging said conductive cleaner element and providing said particulate on said photoconductive element with an electrical potential,
wherein the surface of said photoconductive element when charged has a first voltage level of V 1 and when the photoconductive element is discharged the surface has a second voltage level of V 2 and wherein said electrical potential provides a voltage V 3 for the cleaner element such that V 1 >V 3 >V 2 .
8. The method of claim 7 wherein said particulate electrical potential is sufficient to repel from said charging element associated with said photoconductive element.
9. The method of claim 7 , wherein said cleaner element comprises a conductive polymer.
10. The method of claim 9 , wherein said conductive polymer is a urethane.
11. The method of claim 7 , wherein V 3 about 600 volts DC.
12. The method of claim 7 , wherein said particulate assumes a negative charge.
13. The method of claim 7 , wherein said photoconductive element is a photoconductive drum.
14. The method of claim 7 where said conductive cleaner element is a conductive cleaner blade.
15. The method of claim 7 wherein said particulate comprises paper, CaCO 3 or toner.