Patent ID: 7228083

Claim:
An image forming apparatus comprising: an image forming portion which forms an image on a sheet, wherein the image forming portion can form a test pattern image on the sheet and the test pattern image having a reference image formed in a predetermined density; sheet conveyance path which conveys the sheet on which the image is formed by the image forming portion; image density detection means disposed on said sheet conveyance path for detecting density of the test pattern image formed on the sheet; and control means for performing density adjustment of the image formed on the sheet by the image forming portion based on a detection information of the image density detection means, wherein the image forming portion forms the test pattern on the sheet such that the reference image is not formed at positions in the sheet, the positions are located at the same distances away from a front end of the sheet in a conveyance direction as distances along the conveyance path between the image density detection means and points where entry shock of the sheet front end is generated in the sheet conveyance path on the downstream side of the image density detection means.