Image forming apparatus to form an auto color registration pattern and control method thereof

摘要

An image forming apparatus and a control method enhancing ACR (Auto Color Registration) performance by optimizing ACR patterns are provided. The apparatus includes a photosensitive drum, an exposure unit to radiate the drum to form an latent image, a developing unit supplying color toner corresponding to the latent image, and a transfer belt to which the toner image is transferred. A pattern generating unit forms a latent image corresponding to a predetermined ACR pattern on the drum to form the ACR pattern on the transfer belt, and allowing amounts of gap changes of sub patterns, which form the ACR pattern, to have an average value of about 0, the gap change of sub patterns caused by an AC component generated from a rotation of the drum. A pattern detecting unit detects a pattern formed on the transfer belt, and an ACR executing unit calculates offsets to correct errors.

主权项

1. An image forming apparatus of a single pass scheme comprising a photosensitive drum having an outer circumferential surface on which an electrostatic latent image is formed, an exposure unit configured to radiate light at the photosensitive drum to form the electrostatic latent image on the outer circumferential surface of the photosensitive drum, a developing unit configured to form a toner image by supplying a color toner that corresponds to the electrostatic latent image formed on the outer circumferential surface of the photosensitive drum, and an intermediate transfer belt to which the toner image formed at the outer circumferential surface of the photosensitive drum is transferred, the image forming apparatus comprising:
a pattern generating unit configured to form an electrostatic latent image corresponding to a predetermined ACR (Auto Color Registration) pattern on the outer circumferential surface of the photosensitive drum to form the ACR pattern on the intermediate transfer belt, the pattern generating unit allowing amounts of gap changes of a plurality of sub patterns, which forms the ACR pattern, to have an average value of about 0, the gap change of the plurality of sub patterns caused by an AC component generated from a rotation of the photosensitive drum; a pattern detecting unit configured to detect the ACR pattern that is formed on the intermediate transfer belt; and an ACR executing unit configured to calculate an offset of each color based on the detection result of the pattern detecting unit, and to correct a color registration error by use of the offset calculated.