Patent ID: 8783683

Claim:
An image forming apparatus that forms an image on a sheet of paper, the apparatus comprising: an information acquiring portion which acquires sheet information indicating quality or transporting condition of the transported sheet of paper; a control portion that is configured to shift a reference position which has been previously set to a direction orthogonal to a transporting direction of the sheet of paper based on the sheet information acquired by the information acquiring portion; a detection portion which detects a deviation of the sheet of paper with regard to the reference position shifted by the control portion along the direction that is orthogonal to the transporting direction of the sheet of paper; and a sheet shift portion which shifts the sheet of paper to the reference position shifted by the control portion based on the deviation detected by the detection portion, the sheet shift portion being positioned at an upstream side of an image forming position on which the image is formed on the sheet of paper; wherein the information acquiring portion includes a paper-weight-acquiring part which acquires paper weight as the quality of the transported sheet of paper; wherein the control portion is configured to shift the reference position to the direction orthogonal to the transporting direction of the sheet of paper based on the paper weight of the sheet of paper acquired by the paper-weight-acquiring part; wherein the control portion is configured to stop a shift operation of the reference position when the paper weight of the sheet of paper acquired by the paper-weight-acquiring part is smaller than a previously set weight reference value; and wherein the control portion is configured to perform the shift operation of the reference position when the paper weight of the sheet of paper acquired by the paper-weight-acquiring part is not smaller than the previously set weight reference value.