A drive shaft extends inside a tubular section along a shaft axis, and the drive shaft rotates around the shaft axis while transmitting a driving force generated in a driving source to a driven portion. The drive shaft includes multiple extension sections, and a hard section. Each of the extension sections extends along the shaft axis. The hard section is interposed between two of the extension sections in a direction along the shaft axis, and has a higher rigidity in comparison to that of the extension sections.
