| 摘要 |
An image forming apparatus includes: a sheet storage portion having a sheet stacking portion, a sheet feed portion, a drive portion configured to be capable of switching a lifting speed when lifting the sheet stacking portion between a first lifting speed and a second lifting speed, a height detecting portion configured to be capable of detecting the fact that the sheet reaches a decelerating position for switching the lifting speed of the sheet stacking portion from the first lifting speed to the second lifting speed, a time counting portion, and a control unit. The control unit computes the sheet stacking amount of the sheet stacking portion by using a relationship among the lifting time from a start of the lifting operation of the sheet stacking portion until the sheet reaches a decelerating position, the first lifting speed, and a heightwise position of the decelerating position when the sheet stacked on the sheet stacking portion is lifted to the decelerating position at the first lifting speed by the drive portion and then is lifted to a feeding position at the second lifting speed. |
