Image forming apparatus that controls charging bias applied to charger

摘要

An image forming apparatus includes a controller configured to apply a charging bias to a charger during image formation on a photoconductive body, an absolute value of the charging bias being a first absolute value. The controller applies a development bias to a development roller during the image formation, places the development roller in a development position during the image formation, after the image formation, reduces the absolute value of the charging bias to a second absolute value less than the first absolute value, after reducing the absolute value of the charging bias, separates the development roller away from the photoconductive body and places the development roller in a non-development position, and after placing the development roller in the non-development position, stops applying the development bias to the development roller.

主权项

1. An image forming apparatus comprising:
an image forming unit comprising:
a photoconductive body;a charger configured to charge the photoconductive body; anda development roller; and a controller configured to:
apply a charging bias to the charger during image formation on the photoconductive body, an absolute value of the charging bias being a first absolute value;apply a development bias to the development roller during the image formation on the photoconductive body;place the development roller in a development position during the image formation on the photoconductive body;after the image formation on the photoconductive body, reduce the absolute value of the charging bias to a second absolute value less than the first absolute value and greater than the development bias;after reducing the absolute value of the charging bias, separate the development roller away from the photoconductive body and place the development roller in a non-development position, the non-development position being farther from the photoconductive body than the development position;after placing the development roller in the non-development position, stop applying the development bias to the development roller; andas an accumulated number of sheets image-formed by the photoconductive body increases, set shorter a period of time between when reducing the absolute value of the charging bias and when beginning to separate the development roller away from the photoconductive body.