Browse Prior Art Database

Original Publication Date: 1994-Jun-30
Included in the Prior Art Database: 2004-Apr-07

Publishing Venue

Xerox Disclosure Journal


An integral paper feeding system having a wire board that integrates paper size sensing into the base of a paper tray or cassette is disclosed and shown in Figures 1 and 2. Figure 2 shows a cross-sectional view of Figure 1 along view line 2-2. Wire board 3, mounted at the base of paper feed cassette (or tray) 4, automatically senses the size of loaded paper using multiple actuator switches positioned strategically on the surface of the board. These switches are positioned so that they become actuated when movable paper edge guides 11 and 14 are aligned along guide tracks 12 and 15, respectively. A flexible cover (not shown) printed with informational markings and positioned under the paper guides indicates positions for known paper sizes. The flexible cover additionally protects the wire board and its switches from damage. On the wire board, five push button actuator switches 6, 7, 8, 9 and 10 positioned parallel to guide track 12 and single push button actuator switch 13 positioned parallel to guide track 15 provide paper length and width information respectively to controller 20. Paper guides 11 and 14 register feed sheets 18 with respect to cassette edges 16 and 17. For the controller to determine a known paper size paper guide 11 must actuate at least one switch along guide track 12. Paper guide 14 however is not required to actuate switch 13 since a standard size is assumed when it is not actuated. Once contact is established between connector 22 of control circuit 20 and its reciprocal end located in the paper cassette housing of a printing machine (not shown), the output of each actuator switch is transmitted to control circuit 20. Subsequently, the output of control circuit 20 is transmitted to the controller of the printing machine, thereby providing the printing machine with the size of the currently loaded paper in cassette 4.