Media conveyance system of an ink ejection image forming apparatus

An image forming apparatus comprising:

• an endless conveyance belt which holds and conveys a recording medium
• a nip roller unit which presses a face of the conveyance belt on which the recording medium is held, rotates in accordance with movement of the conveyance belt, and includes a pair of first end pressing parts, wherein the pair of first end pressing parts comprises a particular first end pressing part and a further first end pressing part which are arranged in a width direction of the conveyance belt and hold edges of the recording medium in the width direction between themselves and the conveyance belt, such that a first portion of each of the first end pressing parts contacts the recording medium at the same time that a second portion of each of the first end pressing parts contacts the conveyance belt, the recording medium having a first size, and a first center pressing part arranged between the first end pressing parts;
• and
• a recording head which has a plurality of ink ejecting holes, and ejects ink from the plurality of ink ejecting holes onto the conveyed recording medium to thereby form an image, wherein
• a pressing force of the first center pressing part toward the conveyance belt is set to be smaller than pressing forces of the pair of first end pressing parts toward the conveyance belt.