Abstract:
A hand-operated document processor has a base for receiving a document containing magnetic ink character data to be read and recognized. A manually operated moving magnetic ink character recognition (MICR) subsystem includes a MICR read head and is attached to the base. Movement of the subsystem causes the MICR read head to pass over the magnetic ink character data on the document. MICR reading and recognition logic receives the signal from the MICR read head. A spring/cylinder mechanism includes a spring providing the force necessary to drive the moving MICR subsystem, and includes a dashpot composed of a piston and cylinder arranged such that the spring moves the MICR subsystem across the document being processed and drives the piston in the cylinder, thereby damping the motion of the MICR subsystem.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to document processing, document imaging, and magnetic ink character recognition. The invention further relates to hand-operated document readers/imagers, and to methods and systems for providing controlled and repeatable motion in a non-motorized system. 
     2. Background Art 
     A typical document processing system includes a feeder and a separator in the document-feeding portion of the system, and a series of roller pairs or belts in the document-transporting portion of the system. In the feeding portion of the system, the feeder acts with the separator to feed documents singly, in order, from a stack. In the transporting portion of the system, the roller pairs and/or belts convey the documents, one at a time, past other processing devices such as readers, printers, and sorters that perform operations on the documents. The feeder is typically a feed wheel, but may take other forms. The separator may be a wheel, but also may take other forms such as a belt. Further, the components in the transporting portion of the system may take a variety of forms. 
     In addition to large document processing systems that handle stacks of documents, smaller systems also exist. These smaller document processing systems may handle smaller stacks of documents, or may even handle single documents, fed one at a time. There are also hand-operated document readers/imagers. 
     Banks, credit unions, and other financial institutions use document processing systems to regularly process checks, deposit slips, and other types of bank documents in order to execute financial transactions efficiently. Document processing systems have therefore become quite prevalent in the industry. Typically, information is printed on these documents in magnetic ink which can be read both by the human eye and a computer. This form of printing is read by a process called magnetic ink character recognition (MICR). As part of the recognition process, a MICR magnetic read head is used to read the information printed on the document. 
     Conventional approaches to MICR reading and recognition generally involve determining peak position information for a waveform generated by a single gap magnetic read head. This peak information typically includes information regarding the amount of time between the peaks of each character. Knowledge of the velocity of the document (and thus, the velocity of the characters which are printed on the document) allows this time information to be converted into distance information, which can be compared to the MICR character peak profiles as contained in ANS X9.100-20-2006 (formerly published as X9.27) “Print and Test Specifications for Magnetic Ink Printing (MICR)” as published by Accredited Standards Committee X9, Inc., Annapolis, Md., United States. Based on the design of the standard E-13B character set, in order that a MICR reader reliably read with a high correct character read rate and with a very low substitution rate, the document velocity must be precisely known during reading or otherwise be speed-controlled so that it does not vary. 
     These conventional approaches are acceptable when the velocity of the document is either known or can be controlled. In fact, conventional approaches to MICR typically involve rather complex schemes for controlling the velocity of the document or attempting to measure its velocity at different times as the document moves past the MICR read head. There has also been an approach to MICR reading and recognition that utilizes a dual gap read head to eliminate the need for precise knowledge or control of the document velocity. 
     In a hand-operated document reader/imager, the document is placed on a base and the MICR/image device is moved over the document from right to left, which is the traditional direction of larger document readers. During this movement, the MICR characters are recognized and the front image of the document is captured. 
     In more detail, the operational sequence of a manually operated linear check or document scanning device is as follows. A check or document is positioned on the bed of the device. The module that holds the contact image sensor and the magnetic read head is moved across the check or document, with the module being guided by a linear rod. The magnetic read head reads the MICR code line at the bottom of the document, and the contact image sensor scans the document. Data from both devices are passed to the electronics of the system for processing. 
     In order for the image sensor and magnetic read head to properly read the check or document, the speed of the module must be known over the entire length of the item being scanned. The speed of the scan can be measured by any one of a number of speed measuring devices. The greater the variation of speed, the more sophisticated, and therefore more expensive, the electronics must be, as well as the greater the chance of error. 
     The contact image sensor has a maximum speed limit, beyond which it will fail to operate properly. And, the MICR reader has a minimum speed limit, below which it cannot reliably operate. Accordingly, the speed of the scan must remain between these limits. 
     A motorized system can provide the required speed control, but is expensive. With a simple inexpensive manual operation, the scanning speed can and will vary from item to item, and over the length of the scan of a single item. 
     For the foregoing reasons, there is a need for an improved method and system for providing controlled and repeatable motion in a non-motorized hand-operated reader/imager. 
     SUMMARY OF INVENTION 
     It is an object of the invention to provide an improved method and system for providing controlled and repeatable motion in a non-motorized hand-operated reader/imager. 
     According to the invention, a hand-operated document processor comprises a base for receiving a document containing magnetic ink character data to be read and recognized, and a moving magnetic ink character recognition (MICR) subsystem. The subsystem includes a MICR read head and is attached to the base such that movement of the subsystem causes the MICR read head to pass over the magnetic ink character data on the document. MICR reading and recognition logic receives the signal from the MICR read head. 
     In some implementations, the moving MICR subsystem further comprises an image sensor that passes over the document as the MICR read head passes over the magnetic ink character data on the document. 
     A spring mechanism provides the force necessary to drive the moving MICR subsystem. Preferably, the operator input is limited to sliding the MICR subsystem or scanning module to the start position thereby cocking the spring mechanism, and a latch holds the MICR subsystem against the spring force. 
     In operation of the preferred embodiment of the hand-operated document processor, once the MICR subsystem is at the start position, the document is positioned on the base of the hand-operated document reader/imager. The operator presses a release to allow the spring to pull the MICR subsystem across the document. The energy stored in the spring drives the moving MICR subsystem over the face of the document at a controlled speed. 
     To provide further velocity control over the required scanning distance, the invention comprehends the use of a dashpot or viscous damper. In the preferred embodiment of the hand-operated document processor, a spring and pneumatic cylinder mechanism is connected to the MICR subsystem or scanning module by, for example, a belt and pulley system. The action of the spring moves the module across the length of the check or document being scanned and will drive a piston in the pneumatic cylinder at a rate that is directly proportional to the speed of the scanning module. A reduction mechanism, for example, in the form of a pulley ratio or gear reduction may allow travel of the spring and piston to be less than the travel of the scanning module to reduce the size and complexity of the spring mechanism and cylinder. 
     In a preferred embodiment, the cylinder is constructed with one or more bleed orifices in the cylinder that will be sized to provide minimal resistance to movement at slow speeds and very high resistance to movement at speeds that approach the speed limit of the contact image sensor. The orifices may be adjustable to tune out any variations in friction and system drag during manufacture and over the life of the system. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows the waveform for the magnetic ink character one, from the E-13B MICR character set as used on many financial payment documents, as read from a responsive magnetic signal gap read head when the magnetized character is passed by the magnetic read head; 
         FIG. 2  is a cross-section view of a read head, which is one example of a suitable read head for reading magnetic ink characters; 
         FIG. 3  illustrates a top view of a hand-operated document reader/imager made in accordance with the invention; 
         FIG. 4  illustrates a schematic diagram depicting the spring/cylinder mechanism in an exemplary implementation; 
         FIG. 5  is a block diagram illustrating a moving MICR/image subsystem including a semi-automatic spring/cylinder mechanism; 
         FIG. 6  is a plot of force versus displacement, illustrating spring load versus extension for an extension spring and for a constant force spring; 
         FIG. 7  is a plot of acceleration versus displacement, illustrating load acceleration for an extension spring and for a constant force spring; 
         FIG. 8  is a plot of velocity versus displacement, illustrating load velocity for an extension spring and for a constant force spring; 
         FIG. 9  is a plot of force versus velocity for a pneumatic cylinder resistance load; 
         FIG. 10  is a plot of velocity versus displacement for the MICR subsystem when using the simple extension spring with the pneumatic cylinder; and 
         FIG. 11  illustrates a waveform for magnetic ink characters/symbols 3, 5, 7, Amount when the document containing the characters/symbols is inserted face up for front image capture in the hand-operated document reader/imager, and the magnetic ink characters/symbols are passed over from right to left. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The E-13B character set contains ten characters and four symbols as defined in the ANS X9.100-20-2006 (formerly published as X9.27) “Print and Test Specifications for Magnetic Ink Printing (MICR)” as published by Accredited Standards Committee X9, Inc., Annapolis, Md., United States. When used on a document for automated machine reading, the characters and symbols in the set must be printed using magnetic ink. ANS X9.100-20-2006 defines the dimensions of each character/symbol and the expected nominal waveform peak position and relative amplitude of waveform peaks. 
       FIG. 1  shows the waveform for the magnetic ink character one, from the E-13B MICR character set, as read from a responsive magnetic signal gap read head when the magnetized character is passed by the magnetic read head. The waveform is indicated at  50 . As illustrated, the x-axis represents the position of the read head, and the y-axis represents the signal level. 
     MICR reading and recognition generally involves determining peak position information for a waveform generated by a single gap magnetic read head that passes over the magnetic ink characters on a document. This peak information typically includes information regarding the amount of time between the peaks of each character. Knowledge of the velocity of the document (and thus, the velocity of the characters which are printed on the document) allows this time information to be converted into distance information, which can be compared to the MICR character peak profiles as contained in ANS X9.100-20-2006. 
     In  FIG. 2 , a read head is generally indicated at  60 , and includes a gap  62 . The read head utilizes sensing coil  64 . Core  66  forms a path for the magnetic flux changes experienced when the reader passes over magnetic ink. Of course, it is appreciated that alternative readers may be used, and any suitable technique may be utilized for assuring that flux variation from the magnetic ink characters is sensed. 
     An exemplary embodiment of the invention is illustrated in  FIGS. 3-5 .  FIGS. 3 and 4  illustrate a hand-operated document reader/imager  80 . As best shown in  FIG. 3 , document reader/imager  80  includes a moving MICR/image subsystem  82 . Subsystem  82  includes a contact image sensor  84 , and a MICR read head  86 . Contact image sensor  84  captures an image of the document  100  when subsystem  82  is moved across the document  100 . Contact image sensor  84  captures the front image of the document  100  when the document  100  is placed face-up on the base  92  of the reader/imager  80  and the MICR/image subsystem  82  is moved from right to left over document  100  as indicated by arrow  102 . 
     MICR read head  86  is for reading the magnetic ink character data  104  on document  100 . During the front image capture, the MICR code line is read according to a traditional MICR algorithm as MICR read head  86  passes from right to left over the magnetic ink character data  104  on document  100 . 
     With continuing reference to  FIGS. 3 and 4 , a semi-automatic spring/cylinder mechanism  150  includes a spring mechanism  154  to provide the force necessary to drive the moving MICR subsystem  82 . To provide further velocity control over the required scanning distance, spring/cylinder mechanism  150  further includes a pneumatic cylinder mechanism  160 . The spring/cylinder mechanism  150  is connected by a belt and pulley system  162  to a belt and pulley speed reduction mechanism  164  to drive moving MICR/image subsystem  82  at the required speed for scanning. Moving MICR/image subsystem  82  rides along a linear guide shaft  152  and holds the contact image sensor  84  and the magnetic read head  86 . The magnetic read head  86  reads the MICR code line  104  at the bottom of the document  100 , and the contact image sensor  84  scans the document  100 . In further detail, the belt and pulley reduction mechanism  164  drives pulley  170 . Pulley  170  is connected to pulley  172  by belt  174 . MICR/image subsystem  82  is secured, at attachment member  176 , to belt  174  such that spring/cylinder mechanism  150  is able to drive the MICR/image subsystem  82 . 
     In more detail, spring mechanism  154  includes extension spring  180  connected between member  182  which is secured to belt  186  and member  184  which is secured to base  92  of document reader/imager  80 . In addition to belt  186 , belt and pulley system  162  includes pulleys  188  and  190 , holding belt  186 . Cylinder mechanism  160  includes double-ended pneumatic cylinder  200  and piston  202 . On each side of piston  202 , belt  186  is connected to an end of a piston rod  204 , and cylinder  200  is secured with respect to piston  202 . Speed reduction mechanism  164  allows travel of the spring  180  and piston  202  to be less than the travel of the MICR subsystem  82  to reduce the size and complexity of the spring mechanism and cylinder. The action of the spring  180  moves the MICR subsystem  82  across the length of the check or document being scanned and will drive piston  202  in the pneumatic cylinder  200  at a rate that is directly proportional to the speed of the MICR subsystem  82 . 
     Preferably, the operator input is limited to sliding the MICR subsystem  82  to the start position thereby cocking the spring mechanism  154 , and a latch and release mechanism  220  holds the MICR subsystem  82  against the spring force. In the preferred embodiment illustrated in  FIGS. 3 and 4 , the cylinder  200  is constructed with a pair of bleed orifices  210  sized to provide minimal resistance to movement at slow speeds and very high resistance to movement at speeds that approach the speed limit of the contact image sensor  84 . The orifices  210  may be adjustable to tune out any variations in friction and system drag during manufacture and over the life of the system. 
     With continuing reference to  FIGS. 3 and 4 , in operation of the preferred embodiment, once the document  100  is positioned on the base  92  of the hand-operated document reader/imager  80 , the operator presses the release  220  to allow the spring  180  to pull the MICR subsystem  82  across the document. The energy stored in the spring  180  drives the moving MICR subsystem  82  over the face of the document at a controlled speed. 
     There are several types of springs available that could provide the necessary spring force.  FIG. 6  is a plot of force versus displacement, illustrating spring load versus extension for an extension spring at  240  and for a constant force spring at  242 . As shown in  FIG. 6 , it is possible to have a steadily decreasing load  240  using a simple and inexpensive extension spring or a constant load  242  over the entire travel with a more complex and more expensive constant force spring mechanism. Either spring would be much cheaper than a motorized system.  FIG. 7  is a plot of acceleration versus displacement, illustrating load acceleration for an extension spring at  244  and for a constant force spring at  246 . These springs would provide either a steadily decreasing acceleration  244  or a constant acceleration  246  of the scan module, as shown in  FIG. 7 . Neither of these springs, acting alone, will provide the necessary velocity control over the required scanning distance of a maximum sized document, as shown in  FIG. 8 . In  FIG. 8 , a plot of velocity versus displacement illustrates load velocity for an extension spring at  248  and for a constant force spring at  250 . 
       FIG. 9  is a plot of force versus velocity for a pneumatic cylinder resistance load. As shown in  FIG. 9  at  252 , the physics of the pneumatic cylinder with a bleed orifice will provide constant resistance force at a constant speed. Motion of the MICR subsystem  82  in the desirable speed range will require resistance matched to the design of the spring. With this resistance load that increases as the spring increases the speed of actuating the scanning module, the system will reach an equilibrium speed that, even though variable, will remain within the optimum speed range. This will simplify the measure of the scanning speed and the natural tendency to scan at a constant speed should reduce the complexity of the electronics and reduce the error rate.  FIG. 10  is a plot of velocity versus displacement for the MICR subsystem  82  when using the simple extension spring with the pneumatic cylinder, and depicts the velocity profile for the MICR subsystem  82  at  254 . 
     In the preferred embodiment, the pneumatic cylinder will provide little or no resistance to motion in the return direction, allowing for a fast reset. This will be accomplished by use of reed valves to open and close orifices, depending on the direction of travel. 
     Typically, a signal indicative of the speed of the MICR subsystem  82  is provided to the MICR reading and recognition logic during the scan operation. In order for the image sensor and magnetic read head to properly read the check or document, the speed of the module must be known over the entire length of the item being scanned. The speed of the scan can be measured by any one of a number of speed measuring devices. The greater the variation of speed, the more sophisticated, and therefore more expensive, the electronics must be, as well as the greater the chance of error. A hand-operated document reader/imager requires a method of determining the position, and thus the speed, of the MICR and image sensors due to the variable speed nature of the manual operation. Existing solutions use optical encoders to provide this position feedback. Optical encoders are typically attached directly to the shaft of a wheel that moves along the document being scanned, or are connected to this shaft through a series of gears. For example, as shown in  FIG. 3 , a suitable encoder  260  measures the speed of the MICR subsystem. An output signal from encoder  260  is provided to the MICR reading and recognition logic during the scan operation. 
       FIG. 5  illustrates the moving MICR/image subsystem  82  in block diagram form, including the contact image sensor  84 , MICR read head  86 , and semi-automatic spring/cylinder mechanism  150 . As shown, the document  100  is placed on the base of the reader/imager for front image capture. Moving MICR/image subsystem  82  is moved across the document  100  as indicated by arrow  102 . Block  120  represents the MICR reading and recognition logic. Logic  120  includes a traditional MICR algorithm as understood by one of ordinary skill in the art. 
     In the traditional MICR algorithm, the waveform obtained from the read head  86  is compared against known MICR character peak profiles  122 . If the recognition is successful, the MICR reading and recognition logic  120  determines the recognized MICR characters  124 . The traditional MICR algorithm is applied during the front image capture by contact image sensor  84  of a face-up document. The captured image is indicated at  126 . 
     Logic  120  must be capable of determining the speed of the MICR and image sensors due to the variable nature of the manual operation. In accordance with the invention, semi-automatic spring/cylinder mechanism  150  provides controlled and repeatable motion of the MICR/image subsystem  82 . Speed feedback to the MICR reading and recognition logic  120  may be provided in any suitable way. 
       FIG. 11  illustrates a waveform  270  for magnetic ink characters/symbols 3, 5, 7, Amount when the document containing the characters/symbols is inserted face up for front image capture in the hand-operated document reader/imager, and the magnetic ink characters/symbols are passed over from right to left. As illustrated, the x-axis represents the position of the read head, and the y-axis represents the signal level. The MICR reading and recognition logic is able to produce the waveform depicted at  270  based on the signal from the MICR read head and the speed feedback signal. In this way, the MICR reading and recognition logic can consider the MICR read head speed during reading and recognition. Consideration of MICR read head speed is required because speed variations affect the amount of time between the peaks of each character (as well as the amplitudes of the peaks due to the variation in the rate of change of the magnetic flux resulting from the variation in the read head speed). By considering the read head speed, the time information is able to be converted into distance information, which can be compared to the MICR character peak profiles as contained in ANS X9.100-20-2006. 
     In one implementation, in order to obtain optimal MICR results, the MICR read head signal is sampled at a resolution of 1,000 samples per inch. When the relative speed of the document is known and constant, the desired MICR sampling rate in samples/second is determined by converting from samples per inch to samples per second based on the constant speed. For example, if the relative speed difference between the document and the MICR read head is 20 inches per second, the MICR sampling rate must be 20,000 samples per second to achieve the desired 1,000 samples per inch. 
     In one approach to considering the MICR read head speed during reading and recognition, the sampling rate of the MICR subsystem is varied based on the sensed speed. For example, in order to achieve 1,000 samples per inch, a speed feedback mechanism commands the MICR sampling subsystem to sample every 0.001 inches. In the embodiment of the invention illustrated in  FIGS. 3-5 , this speed feedback is provided by the encoder  260 . Similarly, speed feedback could be used to command the imaging subsystem to achieve a desired samples/inch resolution. 
     While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.