Patent ID: 7421222
Filing Date: 2008-09-02
Classification: G05F

Abstract:
1. A charging device for charging a photoconductor, wherein the photoconductor is rotatable about an axis and has a surface to be charged, the surface having a width a extending in an axial direction of the photoconductor, the charging device comprising: a first saw-tooth electrode section including a pair of electrode plates each formed with at least one saw-tooth shaped electrode that generates corona discharges for charging the charging the photoconductor, each of the pair of electrode plates in the first saw-tooth electrode section having a length; a second saw-tooth electrode section including a pair of electrode plates each formed with at least one saw-tooth shaped electrode that generates corona discharges for charging the charging the photoconductor, each of the pair of electrode plates in the second saw-tooth electrode section having a length; a third saw-tooth electrode section including a pair of electrode plates each formed with at least one saw-tooth shaped electrode that generates corona discharges for charging the charging the photoconductor, each of the pair of electrode plates in the third saw-tooth electrode section having a length; and a current source connected to said first, second, and third electrode sections, wherein the first, second, and third saw-tooth electrode sections are disposed along the surface of the photoconductor in such a manner that the first saw-tooth electrode section is disposed at an upstream side of the second saw-tooth electrode section with respect to a direction in which the photoconductor rotates, the third saw-tooth electrode section is disposed at a downstream side of the second saw-tooth electrode section with respect to the direction in which the photoconductor rotates, and the second saw-tooth electrode section is interposed between the first saw-tooth electrode section and the third saw-tooth electrode section, and wherein said current source is arranged to provide a current flow in a unit length of each of the pair of electrode plates in the first and third saw-tooth electrode sections is ⅓ to 1/1.3 times as much as a current flow in a unit length of each of the pair of electrode plates in the second saw-tooth electrode section.