Compact document measuring system for electronic document imaging

In a document handling system with a document feeding path for sequentially feeding document sheets of varying different standard dimensions, with leading and trailing ends, to be imaged at an imaging station in a feeding direction through said document feeding path from a document input troy sheet output to said imaging station, with a document feeding system of known document sheet feeding velocities, the improvement for automatically determining the dimension of a document sheet being fed in its feeding direction from its leading end to its trailing end before it is imaged, yet providing a compact document handling system with a short said imaged, yet providing a compact document handling system with a short said document feeding path, wherein first and second document sheet edge sensors are provided in the document feeding path, respectively located adjacent the sheet output of said document input tray and upstream of said imaging station, and actuatable by movement therepast of said leading and trailing ends of said document sheet;

• and wherein:
• said document handling system document feeding path from said document input tray to said imaging station is shorter than the longest said standard dimensions document sheets to be fed therethrough,
• said document feeding path has a sheet buckling system including a sheet buckling chamber intermediate of said document input tray and said imaging station,
• said sheet buckling chamber substantially extending normally from said document feeding path,
• said sheet buckling system providing for said feeding of said trailing end of a document sheet faster than said leading end to substantially buckle the intermediate portion of said document sheet out of said document feeding path into said sheet buckling chamber so that said dimension between said trailing and leading ends of the buckled document sheet along the document feeding path is substantially reduced, and so that said trailing end of said buckled document sheet along said document feeding path normally passes and actuates said first document sheet edge sensor in said document feeding path adjacent said sheet output of said document input tray before said leading end of said buckled document sheet in the document feeding path reaches and actuates said second document sheet edge sensor upstream of said imaging station, to provide a timing signal usable for calculating the dimension of the document sheet being fed from said known document sheet feeding velocity of said document handling system, even for document sheets longer than said document feeding path.