Image forming apparatus for determining a target bias voltage value

摘要

There is provided an image forming apparatus including: a forming section having an image holding member and an developing portion, and configured to apply a developing bias voltage to the developing portion to develop an electrostatic latent image on the image holding member; a sensor configured to detect a mark formed by the forming section; a storage; and a controller configured to perform: forming first and second marks, obtaining the densities of the first and second marks, obtaining a slope, and determining a target bias voltage value, and storing the target bias voltage value in the storage.

主权项

1. An image forming apparatus comprising:
a forming section having an image holding member and an developing portion, and configured to apply a developing bias voltage to the developing portion to develop an electrostatic latent image on the image holding member so as to form a toner image of a toner; a sensor configured to detect a mark formed as the toner image by the forming section; a storage; and a controller, wherein the controller is configured to perform:
forming a first mark by applying a developing bias voltage of a first test bias voltage value to the developing portion and developing an electrostatic latent image on the image holding member;forming a second mark by applying a developing bias voltage of a second test bias voltage value to the developing portion and developing the electrostatic latent image on the image holding member;obtaining a density of the first mark and a density of the second mark based on a signal from the sensor;obtaining a slope based on both an amount of change in the first test bias voltage value and the second test bias voltage value and an amount of change in the density of the first mark and the density of the second mark;determining a target bias voltage value corresponding to a target density based on the slope, and at least one of a first set and a second set, wherein the first set includes the first test bias voltage value and the density of the first mark, the second set includes the second test bias voltage value and the density of the second mark; andstoring the target bias voltage value in the storage, wherein the controller is further configured to perform:
detecting a change in a state of the image forming apparatus since a point of time when the forming of the first and second marks has been previously executed, andincreasing of a bias voltage difference between the first and second test bias voltage values to a greater value, as the change in the state of the image forming apparatus is greater.