| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a sheet feeding device in which a length in an axial direction of a drive transmission mechanism transmitting rotation drive force to a sheet feeding roller is shortened as much as possible, and to provide an image reading device and an image forming apparatus including the same.SOLUTION: A drive transmission mechanism 5F includes a first transmission gear 53 and a first input gear 55 to transmit rotation drive force to a pickup roller 51. The first input gear 55 is formed in a cylindrical shape and has a hollow cylindrical space 551 inside, and rotates around the axis when the rotation drive force is input. The first transmission gear 53 rotates around the axis when the rotation drive force is transmitted from the first input gear 55 and is configured capable of slide-moving in the axial direction, to thereby transmit the rotation drive force to the pickup roller 51. A drive transmission portion 5G, which transmits the rotation drive force from the first input gear 55 to the first transmission gear 53, is arranged in the cylindrical space 551 of the first input gear 55.</p> |
