The purpose of this thesis was to develop a method to detect the occurrence of more than one document being drawn into an automatic document feeder such as is used on photocopiers and document scanners. It was desired that the method developed made no physical contact with these documents, worked with all common document materials and thicknesses. The method actually developed monitors the amplitude and phase changes in ultrasound passed through these documents. By using both the amplitude and phase of the ultrasound, a material and thickness independent method, non contact method was successfully developed.
Library of Congress Subject Headings
Scanning systems; Optical scanners; Photocopying
Department, Program, or Center
Electrical Engineering (KGCOE)
Phinney, Daniel, "Multiple document detection with ultrasonics" (1999). Thesis. Rochester Institute of Technology. Accessed from
RIT – Main Campus