An image forming apparatus includes an image forming portion, an endless belt and a plurality of stretching rollers. The stretching rollers includes a tiltable steering roller, a sliding member, a first stretching roller having a smallest diameter, and a second stretching roller having a largest diameter of the diameters. With respect to rotational axis directions of the stretching rollers, lengths of contact portions of the stretching rollers with the belt are shorter than a width of the belt, the length of the contact portion of the first stretching roller with the belt is a first length, the length of the contact portion of the second stretching roller with the belt is a second length shorter than the first length, and end positions of the contact portions of the first and second stretching rollers with respect to the rotational axis direction are different from each other.

A recording medium conveyance device of an inkjet recording device includes a belt-form member, two conveyance rollers, a driver, a supporting board, a suction unit, and a guide roller. The recording medium is placed on the outer circumferential surface of the belt-form member. The belt-form member is pulled over the two conveyance rollers which cause the belt-form member to circulate. The driver causes at least one of the two conveyance rollers to rotate. The supporting board supports the inner circumferential surface of the belt-form member on a plane. The suction unit pulls the recording medium placed on the belt-form member to the outer circumferential surface of the belt-form member. The guide roller is arranged between at least one of the two conveyance rollers and the supporting board and supports the inner circumferential surface of the belt-form member.

A feeding device for digital processing machine includes a paper passage, a friction device, and a sheet-feeding module. The sheet-feeding module is disposed in the paper passage and opposite to the friction device. The sheet-feeding module includes a sheet-feeding roller, a first idle wheel, and a belt. The sheet-feeding roller is for separating a sheet with the friction device. The first idle wheel is disposed in the upstream side of the sheet-feeding roller. The belt encircles the first idle wheel and the axle of the sheet-feeding roller. The sheet-feeding module rotates from a first position to a second position when the sheet-feeding roller rotates, such that the belt contacts the sheet when the sheet-feeding module is at the second position.

A correction mechanism of the belt conveyor device, including a pair of inclined bearings and a pair of main-body guides, corrects meanders of a belt. The pair of inclined bearings include a pair of bearing portions, respectively, and a pair of inclined portions, respectively, that are inclined symmetrically with respect to an axial direction of the rollers. The pair of main-body guides are put into contact with the pair of inclined portions, respectively, and make an end side of the rollers in the axial direction moved in a direction perpendicular to the axial direction, together with the pair of inclined bearings during meandering of the belt. The pair of inclined portions and the pair of main-body guides are placed inside the pair of bearing portions, respectively, in the axial direction, as viewed in a direction perpendicular to the axial direction.