device for conveying single sheets or a shingled sheet stream in a feeder region of a sheet - processing machine of a conveyor table equipped with at least one endless conveyor belt , and at least two rotatably supported deflection rollers over which the conveyor belt is guided , the conveyor belt being disposed so as to convey the sheets in a region between a sheet pile and front stops , wherefrom the sheets are transferable to a further processing location of the sheet - processing machine , includes a motor for driving the conveyor belt uncoupled from the sheet - processing machine , and a computer and control device for triggering the motor with a predetermined velocity profile exhibiting a velocity change as a function of an angular position of the sheet - processing machine ; and method of operating the sheet - conveying device .