A drive switching mechanism includes a transmission gear and a planetary gear configured to transmit a drive from an input gear to an output gear. The drive switching mechanism further includes a swinging member configured to hold the planetary gear such that the planetary gear can swing around the input gear, a retaining unit configured to retain the swinging member in a swing enabled or disabled state, and a releasing unit configured to disengage the planetary gear from the output gear and cause them to be spaced apart. The output gear includes a toothless part that does not engage with a gear section engaging with the transmission gear.