An image forming system includes a target-log-image extracting unit and a relevant-log-image extracting unit. The multi-layer substrate includes a dielectric layer, two circuit layers, and two through holes passing through the dielectric layer. The oligomer removing agent is able to overcome the problems caused by deposition of polyester oligomers, when added to the dyeing bath in a dyeing step for polyester fiber materials or for fiber materials that are composites thereof with other fiber materials. In parallel with the operation, the recognition image data generation unit generates recognition image data adapted to a recognition unit in accordance with the drawing command. The distance between the drive wheel and the driven wheel is thus shortened to facilitate the replacing of the band saw.