A transfer belt system comprising: a steering roller extending along a longitudinal direction, and being tiltable about a fulcrum to adjust an alignment position of a transfer belt that is an endless belt; and a positioning mechanism coupled to the steering roller, to position an adjustable position of the fulcrum of the steering roller, along the longitudinal direction of the steering roller, wherein the positioning mechanism includes: a guide extending along the longitudinal direction of the steering roller, and a movable protrusion to engage with the guide, the protrusion being located at the adjustable position of the fulcrum so that the steering roller is rotatable about the fulcrum, the transfer belt system further comprising: a pair of belt rollers (21, 22) including a first belt roller and a second belt roller, wherein the endless belt is wound about the pair of belt rollers (21, 22); the transfer belt system characterised by an adjustment member attached to the first belt roller that is movable along a longitudinal direction of the first belt roller, wherein a movement of the adjustment member results from a displacement of the endless belt in the longitudinal direction of the first belt roller; and a link mechanism coupled between the adjustment member and the steering roller, the steering roller to tilt about the fulcrum in response to the movement of the adjustment member. a steering roller extending along a longitudinal direction, and being tiltable about a fulcrum to adjust an alignment position of a transfer belt that is an endless belt; and a positioning mechanism coupled to the steering roller, to position an adjustable position of the fulcrum of the steering roller, along the longitudinal direction of the steering roller, wherein the positioning mechanism includes: a guide extending along the longitudinal direction of the steering roller, and a movable protrusion to engage with the guide, the protrusion being located at the adjustable position of the fulcrum so that the steering roller is rotatable about the fulcrum, the transfer belt system further comprising: a pair of belt rollers (21, 22) including a first belt roller and a second belt roller, wherein the endless belt is wound about the pair of belt rollers (21, 22); the transfer belt system characterised by an adjustment member attached to the first belt roller that is movable along a longitudinal direction of the first belt roller, wherein a movement of the adjustment member results from a displacement of the endless belt in the longitudinal direction of the first belt roller; and a link mechanism coupled between the adjustment member and the steering roller, the steering roller to tilt about the fulcrum in response to the movement of the adjustment member. a guide extending along the longitudinal direction of the steering roller, and a movable protrusion to engage with the guide, the protrusion being located at the adjustable position of the fulcrum so that the steering roller is rotatable about the fulcrum, the transfer belt system further comprising: a pair of belt rollers (21, 22) including a first belt roller and a second belt roller, wherein the endless belt is wound about the pair of belt rollers (21, 22); the transfer belt system characterised by an adjustment member attached to the first belt roller that is movable along a longitudinal direction of the first belt roller, wherein a movement of the adjustment member results from a displacement of the endless belt in the longitudinal direction of the first belt roller; and a link mechanism coupled between the adjustment member and the steering roller, the steering roller to tilt about the fulcrum in response to the movement of the adjustment member. a pair of belt rollers (21, 22) including a first belt roller and a second belt roller, wherein the endless belt is wound about the pair of belt rollers (21, 22); the transfer belt system characterised by an adjustment member attached to the first belt roller that is movable along a longitudinal direction of the first belt roller, wherein a movement of the adjustment member results from a displacement of the endless belt in the longitudinal direction of the first belt roller; and a link mechanism coupled between the adjustment member and the steering roller, the steering roller to tilt about the fulcrum in response to the movement of the adjustment member.