Disc cleaning mechanism and disc cleaning device

Cleaner liquid flow passages for discharging cleaner liquid from a rotatable brush unit are formed in a rotatable brush unit. The cleaner liquid flow passages are formed as passages wherein the cleaner liquid fed to a hollow portion in a rotary shaft flows to openings in brush cleaner circular plates via lateral grooves provided around the outer circumference of a core roller and along the axial direction. A cleaner liquid fed to discs from a cleaner nozzle contains dirt when the discs are cleaned and the dirt is sucked into the cleaner liquid passages and the dirt is discharged from the rotatable brush unit.