PURPOSE: To easily prevent jitters from being generated with low cost by providing a transmission gear with a unidirectional clutch which locks rotation in the opposite direction from the driving direction of a motor.

CONSTITUTION: First and second transmission gears 33 and 34 are borne on a shaft 32 by the unidirectional clutch 36. This unidirectional clutch 36 locks both transmission gears 33 and 34 when the transmission gears 33 and 34 rotate in the opposite direction from the direction in which a photosensitive body 13 is driven and rotated. The unidirectional clutch 36, therefore, inhibit backlashes between an photosensitive body gear 35 and a 2nd transmission gear 34, and between the 1st transmission gear 33 and 2nd speed reduction gear 31. Namely, the unidirectional clutch 36 locks the rotation in the opposite direction from the driving direction of the transmission gears 33 and 34, so the small-sized electrophotographic recording device easily prevents jitters from being generated with low cost.