LONG FIELD REFLECTIVE PAPER SKEW SENSOR INSTRUMENT
Original Publication Date: 1984-Aug-31
Included in the Prior Art Database: 2004-Apr-04
Xerox Disclosure Journal
With reference to the figure, there is shown a sensor to measure the lead and trail edge skew angle of a moving sheet of paper through a reprographic machine. Since, by its nature, laser produces a small, collimated point of bright light, it was chosen as the illumination source for this instrument. A .5mW HeNe laser 1 is connected to a YJ" channel piece of extruded aluminum, hereafter known as the "optic bar" 2. Two mirrors, placed a known distance apart and resting at 45 degree angles are inserted into the optic bar. One mirror is a half silvered, beam-splitter 3, while the second is a 94% front surface unit 4.