A roller mechanism includes a pair of rollers and an urging unit. The pair of rollers oppose one another sandwiching a conveyance path of a sheet material, and are provided to be capable of increasing and reducing an axis-to-axis separation thereof. The urging unit urges at least one of the pair of rollers in a direction of reducing the axis-to-axis separation of the pair of rollers with an urging force that increases with an increase in the axis-to-axis separation of the pair of rollers, and presses the sheet material with the pair of rollers. The urging unit increases the urging force non-linearly, with a rate of increase of the urging force falling as the axis-to-axis separation of the pair of rollers increases within a range of changes at times of sheet material-pressing.