Currency note width detector

Apparatus for accurately determining the width of a document between edges in a direction transverse to the path of movement of the document including in combination first and second pluralities of energizable light emitting devices disposed along a line extending transversely of said path from respective first and second reference points spaced by a predetermined distance, said pluralities of devices including devices at the ends of said line, respective strip photodiodes common to said pluralities of devices, means mounting said strip photodiodes on the opposite sides of said path from their associated plurality of devices whereby a document moving along said path for each plurality completely blocks light from some of said devices to the associated photodiode while leaving others completely unblocked and only partially blocking a particular device of the plurality adjacent to the associated edge, and inwardly of the device at the corresponding end of said line, respective means for sequentially energizing the devices of said pluralities one-by-one in certain directions from the associated reference points, respective means responsive to said photodiodes for producing a voltage at a particular level in response to light from a completely unblocked device of said pluralities, respective means associated with said voltage producing means for detecting a deviation of said voltage from said level in response to light from one of said only partially blocked particular devices adjacent to said edges and inwardly of the device at the corresponding end of said line, respective first means responsive to the output of one of said deviation detecting means for inhibiting further operation of the energizing means associated with the corresponding plurality of devices, upon the occurrence of a deviation, respective second means responsive to said deviation detecting means for determining the percent by which the corresponding particular device is only partially blocked, means for counting the number of completely unblocked energized devices of said pluralities and means for combining the count of said counting means with the percent unblocked determinations of the pluralities.

Apparatus for accurately determining the position with respect to a reference point of the edge of a document travelling along a path including in combination

• a plurality of discrete energy radiating elements disposed along a line extending transversely of said path from said reference point,
• energy detecting means common to said elements,
• means mounting said elements and said detecting means in cooperative relationship adjacent to said path whereby a document moving along said path completely covers certain of said elements while leaving others completely uncovered and only partially covering a particular element adjacent to said edge, means for sequentially activating said elements one-by-one,
• said energy detecting means producing a voltage at a particular level in response to radiation from an element in one of said completely covered or completely uncovered conditions,
• said energy detecting means producing a voltage which deviates from said particular level in response to radiation from said only partially covered particular element adjacent to said edge,
• means for sensing a deviation of said voltage from said level in response to radiation from said only partially covered particular element adjacent to said edge,
• means responsive to said element activating means and to said voltage at said particular level for counting the number of completely covered or completely uncovered elements,
• an analog-to-digital converter,
• means responsive solely to said deviation sensing means for coupling only the detecting means voltage resulting from said partially covered element to said analog-to-digital converter to determine the percent by which said particular element is partially covered or partially uncovered and
• means responsive to said counting means and to said percent determining means for providing an accurate determination of the position of said edge with respect to said reference point.

Apparatus for producing an accurate indication of the dimension between edges of a document travelling along a path in a direction including in combination,

• a plurality of discrete energizable radiation emitting elements disposed along a line transverse to said path, said line having a length exceeding the greatest document dimension to be encountered,
• radiation detecting means common to the devices of said plurality along said line,
• means mounting said elements and said detecting means in cooperative relationship adjacent to said path whereby a document moving along said path completely covers certain of said elements while leaving certain other completely uncovered and only partially covering particular elements adjacent to said edges,
• means for sequentially energizing said elements one-by-one,
• said energy detecting means producing a voltage at a particular level in response to radiation from an element in one of said completely covered or completely uncovered conditions,
• said energy detecting means producing a voltage which deviates from said particular level in response to radiation from said only partially covered particular element adjacent to said edge,
• means for sensing a deviation of said voltage from said level in response to radiation from said only partially covered particular elements adjacent to said edges,
• means responsive to said element activating means and to said voltage at said particular level for counting the number of completely covered or completely uncovered elements,
• an analog-to-digital converter,
• means responsive solely to said deviation sensing means for coupling only the detecting means voltage resulting from said partially covered elements to said analog-to-digital converter to determine the percents by which said particular elements are partially covered or partially uncovered and
• means responsive to said counting means and to said percent determining means for providing an accurate indication of the dimension of said document between said edges.