Image forming apparatus

摘要

A control portion controls a drive of rotation of an image carrier and registers a second index with a first index passing through a transfer position at real time at the time of image formation. Before starting the image formation, the toner image forming portion is controlled to adjust misalignment between the first index and the second index. Accordingly, the second index is formed at a position on the image carrier which is registered with the first index in advance, so that a large amount of control for compensating a large amount of phase misalignment is no longer necessary.

主权项

1. An image forming apparatus comprising:
an image carrier; a toner image forming portion configured to form a toner image on the image carrier; a belt member on which the toner image carried on the image carrier is transferred at a transfer position; a first index preparing portion configured to prepare a first index on the belt member before the toner image carried on the image carrier is transferred, the first index corresponding to a position on the belt member in a direction of movement of the belt member of the toner image to be transferred from the image carrier; a second index preparing portion configured to prepare a second index on the image carrier, the second index corresponding to a position on the image carrier in a direction of rotation of the image carrier of the toner image; a first index detecting portion configured to detect the first index; a second index detecting portion configured to detect the second index; and a control portion configured to control the toner image forming portion such that a position on the image carrier where the second index is to be formed is registered to the first index at the transfer position before starting formation of the second index by the second index preparing portion and to control a drive of the image carrier such that the second index is registered to the first index at the transfer position, after the formation of the second index by the second index preparing portion has started, on a basis of results of the detection of the first index detecting portion and the second index detecting portion.