| 摘要 |
PROBLEM TO BE SOLVED: To provide a sheet feeder with a remaining quantity detection mechanism that can properly determines the remaining quantity after the power source is turned off, is simple, and never upsizes the sheet feeder, and an image formation apparatus.SOLUTION: A sheet feeder 30 includes a lifter plate on which sheets are stacked, a sector gear 39 which is made to interlock with the lifter plate, and moves up and down the lifter plate, and a lifter detection sensor 43 which detects the lifter plate beginning to be moved up. Further, the sheet feeder 30 includes a light shield member 45 which alternates a non-detection state in which the lifter detection sensor 43 does not detect the lifter plate beginning to be moved up and a detection state in which the lifter detection sensor 43 detects the lifter plate beginning to be moved up, and engagement means (44, 47, 50, and 55) of making the light shield member 45 change from the non-detection state to the detection state when the light shield member 45 is rotated by rotation of the sector gear 39, and absorbing further rotating operation of the sector gear 39 while holding the detection state. |
