Patent ID: 9599936
Date: 2017-03-21
CPC Classifications: G03G

Claim:
1. An image forming apparatus comprising: an image former which forms a toner image on an intermediate transfer belt; a secondary transfer roller which transfers the toner image formed on the intermediate transfer belt to a recording medium in a transfer nip; an opposite roller which is placed, to be opposite to the secondary transfer roller, on an inner peripheral surface of the intermediate transfer belt, and forms the transfer nip; an opposite roller switching mechanism which switches the opposite roller which forms the transfer nip to a first opposite roller having a predetermined outer diameter or a second opposite roller having an outer diameter different from the outer diameter of the first opposite roller; a paper type information acquirer which acquires type information of a recording medium used; and a controller which controls the opposite roller switching mechanism based on the type information acquired from the paper type information acquirer, wherein a nip width w the controller allows the first opposite roller to form the transfer nip when judging that a quantity of concavities and convexities on a surface of a recording medium used is not larger than a predetermined quantity, and allows the switched second opposite roller to form the transfer nip when judging that the quantity of concavities and convexities on the surface of the recording medium used is larger than the predetermined quantity.