To prevent a sudden change in conveyance speed when a rear end of a recording material passes through a pair of holding and conveying members on the upstream side in a conveyance direction, and thereby appropriately perform processing using a pattern image.SOLUTION: A reading device comprises: a pair of holding and conveying members 55 that hold and convey a recording material P; separation moving means 58 that moves the pair of holding and conveying members in a separation direction before a rear end of the recording material being held and conveyed by the pair of holding and conveying members passes through the pair of holding and conveying members; and reading means 51 that reads a pattern image on the recording material or a pattern image on another recording material being conveyed by the same conveyance means as for the recording material, on the downstream side in a conveyance direction of the pair of holding and conveying members, in a period including the timing at which the rear end of the recording material passes through the pair of holding and conveying members.SELECTED DRAWING: Figure 9