Abstract: A system to detect if the positions of a tray's sheet guides have been changed while the tray has been open includes a spring loaded stud in the tray that is pushed and locked into an ‘in’ position every time the tray is pushed in. When the tray is pulled out, if the size guides are moved, the spring-loaded stud is released by a linkage mechanism from the guides to the stud. The stud actuates a sensor flag, and as the tray is pushed home, a sensor checks the flag and a control system subsequently deduces whether the guides have been moved.

Abstract: A substrate tray includes a tall backstop guide that is attached to the bottom of the feed tray and which rotates about a vertical axis into three positions 45° apart, presenting four different surfaces to a stack of substrates in the tray. Each surface accommodates a different substrate size and thereby accommodates four different widths of substrates. The backstop guide includes a cam member that is flexed against a back wall of the tray when a load is applied to the backstop guide by the stack of substrates shifting inboard if the tray is pushed to forcefully into a machine after loading, in order to prevent skewing of the substrates.