Image formation apparatus

Abstract

An image formation apparatus includes: a photoconductor; a charging section that applies a bias voltage having an AC voltage superposed on a DC voltage and charges the photoconductor; a controller that controls at least one of the AC voltage and an AC current applied by the charging section; and a detector that detects an amount of discharge occurring between the photoconductor and the charging section. The controller controls at least one of the AC voltage and the AC current so that the amount of discharge detected by the detector falls within a predetermined range containing a singularity in change of the amount of discharge.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the present invention will be described in detail based on the following figure, wherein

FIG. 1 is a side view to show an image formation apparatus according to an exemplary embodiment of the invention;

FIG. 2 is a longitudinal sectional view to show an image formation section according to the exemplary embodiment of the invention;

FIG. 3 is a schematic drawing to show the configurations of a photoconductor and a charging device according to the exemplary embodiment of the invention;

FIG. 4A is a graph to show the relationship between AC voltage (Vpp) and photoconductor surface potential as for charging of the photoconductor according to the exemplary embodiment of the invention;

FIG. 4B is a graph to show the relationship between AC voltage (Vpp) and amount of discharge Q as for charging of the photoconductor according to the exemplary embodiment of the invention;

FIG. 5 is a graph to show the relationship between AC voltage (Vpp) and amount of discharge Q in change of temperature and humidity as for charging of the photoconductor according to the exemplary embodiment of the invention;

FIG. 6 is a flowchart to describe initialization processing of AC voltage (Vpp) in the charging device according to the exemplary embodiment of the invention;

FIG. 7 is a flowchart to describe charging control processing of the charging device according to the exemplary embodiment of the invention;

FIG. 8A is graphs to show the relationship between AC voltage (Vpp) and amount of discharge Q in charging of the photoconductor according to the exemplary embodiment of the invention and show an example wherein change amount (Δq) among three points of amount of discharge Q is equal to or less than predetermined value; and

FIG. 8B is graphs to show the relationship between AC voltage (Vpp) and amount of discharge Q in charging of the photoconductor according to the exemplary embodiment of the invention and show an example wherein change amount (Δq) among three points of amount of discharge Q is equal to or greater than predetermined value.

Claims

1. An image formation apparatus comprising: a photoconductor;a charging section that applies a bias voltage comprising an AC voltage superposed on a DC voltage and charges the photoconductor;a controller that controls at least one of the AC voltage and an AC current applied by the charging section; anda detector that detects an amount of discharge occurring between the photoconductor and the charging section,wherein the controller controls at least one of the AC voltage and the AC current so that the amount of discharge detected by the detector falls within a predetermined range containing a singularity in change of the amount of discharge.

2. The image formation apparatus as claimed in claim 1, wherein the controller controls at least one of the AC voltage and the AC current so that the amount of discharge detected by the detector becomes equal to or greater than the singularity in change of the amount of discharge and becomes equal to or less than a predetermined charge amount.

3. The image formation apparatus as claimed in claim 1, wherein the controller controls at least one of the AC voltage and the AC current so that the amount of discharge detected by the detector becomes the singularity in change of the amount of discharge.

4. The image formation apparatus as claimed in claim 1, wherein the controller controls at least one of the AC voltage and the AC current to become a value resulting from multiplying at least one of the AC voltage and the AC current at the singularity in change of the amount of discharge by a predetermined value.

5. The image formation apparatus as claimed in claim 1, wherein the controller controls at least one of the AC voltage and the AC current to become a value resulting from adding a predetermined value to at least one of the AC voltage and the AC current at the singularity in change of the amount of discharge.

6. The image formation apparatus as claimed in claim 1, wherein the detector detects the amount of discharge occurring on a plus side of the AC current flowing between the photoconductor and the charging section.

7. The image formation apparatus as claimed in claim 1, wherein an abrasion amount of the photoconductor for 1000 revolutions thereof is about 20 nm or less.

8. The image formation apparatus as claimed in claim 1, wherein the photoconductor comprises a charge transport layer, andthe charge transport layer has a thickness of about 25 μm or less.