Media transport assembly incorporating vacuum grooves to flatten sheet

摘要

A media transport system for transporting a media sheet in a marking device includes an entrance drive assembly, an exit drive assembly and a vacuum generator that applies a vacuum force to the media sheet to form a wide, flat printing zone. The entrance drive assembly receives and transports the media sheet in a process direction by contacting top and bottom surfaces of the media sheet, thereby exerting an entrance drive force on the media sheet. The exit drive assembly receives and transports the media sheet by contacting the top and bottom surfaces of the media sheet, thereby exerting an exit drive force on the media sheet. The vacuum force is applied to the media sheet in an area of the media sheet between the entrance drive assembly and the exit drive assembly. The vacuum force on the media sheet acts in a vacuum force direction substantially normal to the process direction. The vacuum force is set such that the entrance drive force and the exit drive force in the process direction each exceed the vacuum force acting in the vacuum force direction.