Apparatus and method of reducing charge roller contamination
View Patent ↗An image forming equipment, e.g., a laser printer includes a photoconductive (PC) drum and an associated charge roller and incorporates a conductive polymer cleaner blade having 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 elements within an image forming apparatus, the device comprising:
a photoconductive element having a surface, wherein said surface of said photoconductive element has a charged state at a first voltage level V 1 and discharged state at a second voltage level V 2 ;
a charging element positioned against said photoconductive element for charging said photoconductive element to said charged state; and
a conductive polymer cleaner blade for said photoconductive element, said cleaner blade having a resistance of about 2.75×10 8 to about 4.25×10 8 ohms, including all ranges and values therebetween, and an edge in contact with said surface of said photoconductive element with said edge of said cleaner blade having a continuously applied third voltage level V 3 wherein |V 1 |>|V 2 |>|V 3 | and said particulate is charged by said edge of said cleaner blade such that said particulate is repelled by said charging element.
2. The device of claim 1 wherein |V 1 | is about 1100 volts, |V 2 | is about 325 volts and |V 3 | is about 275 volts DC.
3. The device of claim 1 , wherein said conductive polymer is a urethane.
4. The device of claim 1 , wherein said conductive cleaner blade has a resistance of about 3.50×10 8 ohms.
5. The device of claim 1 , wherein said voltage levels are one of a negative polarity and a positive polarity.
6. The device of claim 1 , wherein said photoconductive element is a photoconductive drum and said charging element is a charge roller positioned against said photoconductive drum.
7. A method for reducing the buildup of particulate contamination elements in an image forming apparatus, said method comprising:
providing a photoconductive element having a surface containing particulate contamination and a charging element for said photoconductive element;
providing a conductive polymer cleaner blade for said photoconductive element, said conductive polymer cleaner blade having a resistance of about 2.75×10 8 to about 4.25×10 8 ohms, including all ranges and values therebetween, and an edge in contact with said surface of said photoconductive element;
charging said conductive polymer cleaner blade and providing said particulate contamination 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 said photoconductive element is discharged the surface has a second voltage level of V 2 , and wherein said electrical potential provides a continuously applied voltage V 3 for the cleaner blade such that |V 1 |>|V 2 |>|V 3 |; and
periodically reversing a rotational direction of said photoconductive element a distance.
8. The method of claim 7 wherein said particulate contamination electrical potential is sufficient to repel from said charging element.
9. The method of claim 7 , wherein |V 1 | is about 1100 volts, |V 2 | is about 325 volts and |V 3 | is about 275 volts DC.
10. The method of claim 7 , wherein said conductive polymer is a urethane.
11. The method of claim 7 , wherein said cleaner blade has a resistance of about 3.50×10 8 ohms.
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 wherein said particulate contamination comprises paper, CaCO 3 or toner.
15. The method of claim 7 wherein said distance is about 1 millimeter.