Patent Publication Number: US-7900907-B2

Title: Media processing device

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention relates to a media processing device that reads contained information such as magnetic ink characters and image information from sheet media such as checks while conveying the media one at a time through a transportation path, and relates more particularly to a media processing device that can suppress fluctuations in the sheet media transportation speed so that the contained information can be accurately scanned. 
     2. Description of Related Art 
     Banks and other financial institutions use check readers to image and read magnetic ink characters from checks, promissory notes, and other check-like negotiable instruments, and to sort the checks based on the acquired information. As electronic check processing has become more common in recent years the scanned image data and magnetic ink character data is also processed and managed using computers. See, for example, the check readers taught in Japanese Unexamined Patent Appl. Pub. JP-A-2004-206362, U.S. Patent Application 2004/025626, and Japanese Unexamined Patent Appl. Pub. JP-A-2001-48362. 
     Separation mechanisms for separating and feeding multifed checks and other sheet media one by one for processing include pad separation devices and retard roller devices. Pad separation devices push the end part of the sheet media against a separation pad that is made from a material with a high coefficient of friction while driving a feed roller to separate and feed one sheet medium. Retard roller devices separate the sheet media by passing the media between a media feed roller and a retard roller, which is pressed against the media feed roller and applies a rotational load. Both methods create resistance to the transportation direction of the sheet media being fed in order to separate multifed sheet media one by one in the transportation direction. 
     Japanese Unexamined Patent Appl. Pub. JP-A-2001-48362 teaches a sheet supply mechanism for separating and supplying high rigidity sheet media one by one. This sheet supply mechanism rotatably supports a separation pad so that the contact surface of the separation pad tightly contacts the end of the sheets supplied from inside a cassette case, and prevents sheets from being supplied in a stack to the retard roller type separation roller. 
     The transportation mechanism for conveying sheet media fed that are fed one at a time through a separation mechanism as described in Japanese Unexamined Patent Appl. Pub. JP-A-2004-206362 and U.S. Patent Application 2004/025626 transfers torque from a transportation motor through an intervening endless belt to a plurality of transportation rollers disposed along the transportation path, and sequentially conveys the sheet medium from an upstream-side transportation roller to the next downstream-side transportation roller along the transportation path. 
     If the check speed is fast, if the coefficient of friction between the check and the transportation roller is low because the check surface is particularly smooth, for example, or if the check transportation load is high, a certain small amount of slippage between the transportation roller and check occurs even if the relay capacity (μF) of the transportation roller is increased. If the check being conveyed slips while information is being read by the magnetic head or scanner, the reading accuracy of the information drops because of fluctuations in the transportation speed. 
     Furthermore, because the separation mechanism separates the media by applying a resistance to the transportation direction, the transportation load when conveying a check varies greatly depending on whether a part of the check is still inside the separation mechanism or whether the check has completely passed the separation mechanism and no part is still inside the separation mechanism. The check causes this variation in the transportation resistance of the separation mechanism to directly affect the transportation roller that receives and conveys the check from the separation mechanism to the scanning position of the scanner, for example. This produces slipping between the transportation roller and the check, which causes the speed of the check to vary as it is conveyed while being read by the scanner, for example, and can result in a drop in scanning precision and reading accuracy. 
     The nipping pressure (F) applied by the transportation roller to the check must be increased to increase the relay capacity of the transportation roller in order to reduce slipping of the checks conveyed by the transportation roller. However, this requires a design change, such as increasing the strength or rigidity of the transportation roller support shaft, which increases device size. Furthermore, because the required relay capacity of the transportation roller is affected by the coefficient of friction between the transportation roller and the surface of the check, differences in the condition of the check surface cause transportation roller slippage to vary. This causes the transportation speed to vary from check to check and reduces the reliability of information read from the checks. 
     SUMMARY OF THE INVENTION 
     A media processing device according to the present invention can convey sheet media at a constant speed of transportation passed an information scanning position without increasing the nip pressure of the transportation roller. 
     A media processing device according to a first embodiment of the invention has a media transportation path for conveying sheet media; an information reader that is disposed to an information reading position on the media transportation path and reads contained information on the sheet media passing the information reading position; a separation mechanism that separates and feeds the sheet media; and a transportation mechanism that conveys the sheet media delivered from the separation mechanism toward the information reading position. The transportation mechanism includes a first transportation roller disposed on an upstream side in the transportation direction, and a second transportation roller disposed on a downstream side in the transportation direction; and the sheet media transportation speed of the first transportation roller is faster than the transportation speed of the second transportation roller. 
     With the media processing device according to the invention sheet media delivered from the separation mechanism are fed first to the first transportation roller that turns at a fast media transportation speed, and then from there to the second transportation roller. The feed speed of the first transportation roller is set to be faster than the speed of the second transportation roller even if there is some slipping between the first transportation roller and the sheet medium. The sheet medium advanced to the second transportation roller is thus conveyed at a slower speed than the transportation speed of the first transportation roller to the information reading position. As a result, slack is produced by this difference in roller speed in the part of the sheet media that is between the first transportation roller and the second transportation roller. This slack prevents the effect of resistance and transportation load imposed by the separation mechanism from being passed from the first transportation roller to the second transportation roller. More specifically, the transportation resistance produced by the separation mechanism acts on the first transportation roller but does not act on the second transportation roller. Variation in the load on the second transportation roller is therefore suppressed, and the sheet media can be conveyed passed the information reading position at a constant speed while the information reader scans the media without the second transportation roller slipping against the medium. 
     Preferably, the difference between the peripheral velocity of the first transportation roller and second transportation roller is approximately 2% to 3%. This difference prevents any effect on the second transportation roller even if the first transportation roller slips against the sheet medium. 
     If the transportation mechanism has an endless belt that engages the first transportation roller and second transportation roller and a common transportation motor, and rotationally drives the rollers by means of a common power transfer mechanism, the angular velocity of the first transportation roller and second transportation roller will be the same. In this case the outside diameter of the first transportation roller is preferably greater than the outside diameter of the second transportation roller. 
     If the outside diameter of the first transportation roller and the second transportation roller are the same, the same effect can be achieved by driving the first transportation roller at a faster angular velocity than the angular velocity of the second transportation roller. 
     Further preferably, the separation mechanism includes a separation roller and a retard roller that is pressed against the separation roller. This enables separating and feeding checks and other sheet media that are multifed one by one. 
     The separation mechanism may alternatively use a separation pad to separate and feed checks and other sheet media that are multifed one by one. 
     Further preferably, the information reader is a magnetic head and/or a scanner for reading magnetic ink characters or image data from the sheet media at the information reading position. 
     A media processing device according to the present invention disposes first and second transportation rollers between the information reader and the separation mechanism that produces a transportation load or variation in the transportation load. The transportation speed of the upstream-side first transportation roller is set to be greater than the transportation speed of the downstream-side second transportation roller even if the first transportation roller slips slightly against the sheet media, thereby producing slack in the sheet media between the first and second transportation rollers. 
     The invention therefore prevents the transportation load imposed by the separation mechanism from acting on the second transportation roller that feeds the sheet media to the information reading position. The transportation load on the second transportation roller can therefore be reduced and variation in the transportation load can be suppressed. The transportation speed is thus constant, and slipping between the second transportation roller and the sheet media can be minimized. 
     The invention can thus improve the relay capacity of the second transportation roller, convey the sheet media at a constant speed passed the information reading position, and prevent a drop in the reading accuracy of the information reader. 
     Other objects and attainments together with a fuller understanding of the invention will become apparent and appreciated by referring to the following description and claims taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an external oblique view of a check processing device according to the invention. 
         FIG. 2  is a plan view of the check processing device shown in  FIG. 1 . 
         FIG. 3  describes the internal arrangement of the check processing device shown in  FIG. 1 . 
         FIG. 4  describes the check transportation mechanism. 
         FIG. 5A  describes the part of the check transportation mechanism from the separation mechanism to the scanning position. 
         FIG. 5B  describes check transportation from the separation mechanism to the scanning position. 
         FIG. 6  is a block diagram of the control system of the check processing device shown in  FIG. 1 . 
         FIG. 7  is a flow chart describing the operation of the check processing device shown in  FIG. 1 . 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     A preferred embodiment of a check processing device according to the present invention is described below with reference to the accompanying figures. 
       FIG. 1  is an external oblique view of a check processing device  1  according to the invention, and  FIG. 2  is a plan view of the same. 
     This check processing device  1  has a case  2  and a rear case  3  that covers the top of the case  2 , and various parts and assemblies are disposed inside the case. A transportation path  5  for conveying checks  4  (sheet media) is formed in the rear case  3 . 
     The check transportation path  5  is a narrow vertical slot that curves in a basically U-shaped configuration when seen from above, and includes a straight upstream-side transportation path portion  6 , a curved transportation path portion  7  that continues from the upstream-side transportation path portion  6 , and a slightly curving downstream-side transportation path portion  8  that continues from the curved transportation path portion  7 . 
     The upstream end of the upstream-side transportation path portion  6  communicates with a check loading unit  9 , which is a wide vertical slot. The downstream end of the downstream-side transportation path portion  8  is connected through left and right diversion paths  10   a ,  10   b  to first and second check discharge units  11  and  12 , which are wide vertical slots. 
     The checks  4  that are read have an MICR line  4 A printed along the bottom edge on the front  4   a  of the check  4 . Also recorded on the front  4   a  against a patterned background are the check amount, payer and payee, various numbers, and the payer signature. An endorsement is recorded on the back  4   b  of the check  4 . 
     Check Transportation Mechanism 
       FIG. 3  describes the check transportation mechanism rendered in the check processing device  1 , and  FIG. 4  describes the part of this mechanism that conveys checks through the transportation path  5 . 
     Referring first to  FIG. 3 , an infeed roller  13  and a pressure member  14  are disposed to the check loading unit  9 . The infeed roller  13  feeds checks  4  which are loaded in a stack in the check loading unit  9  into the transportation path  5 . The pressure member  14  presses the checks  4  against the infeed roller  13 . 
     Disposed to the infeed path  15  for feeding the checks  4  delivered by the infeed roller  13  into the transportation path  5  are a separation pad  16  and a pair of separation rollers including a separation roller  17  and a retard roller  18 . The separation pad  16 , separation roller  17 , and retard roller  18  render a separation mechanism for separating and feeding the checks  4  one at a time from the stack into the transportation path  5 . The separation pad  16  is made from cork, urethane, or other material with a high coefficient of friction. The infeed roller  13 , the separation roller  17 , and the pressure member  14  are driven by a common feed motor  19 . 
     Referring to  FIG. 3  and  FIG. 4 , the transportation mechanism for conveying the checks  4  along the transportation path  5  includes a transportation motor  21 , a drive pulley  22  mounted on the rotating shaft of the transportation motor  21 , a set of transportation rollers  31  to  36  disposed along the transportation path  5 , a transfer pulley  37 , a set of pressure rollers  41  to  46  that are pressed against and rotate with the transportation rollers  31  to  36 , and a pressure roller  47  that is driven by the transfer pulley  37 . 
     Rotation of the pressure roller  47  is transferred through a transfer gear  48  to a discharge roller  49 . An endless belt  23  transfers rotation of the transportation motor  21  shaft to the transportation rollers  31  to  36 . The endless belt  23  travels along an endless loop from the drive pulley  22  passed a guide roller  24 , a transportation roller  36 , a guide pulley  25 , the transfer pulley  37 , transportation rollers  31  and  32 , guide pulleys  26  and  27 , transportation rollers  33 ,  34 , and  35 , and back to the drive pulley  22 . 
     The transportation rollers  31  to  34  are located at the upstream end, the middle, and at the junction to the curved transportation path portion  7 . Transportation roller  35  is located on the downstream side of the curved transportation path portion  7 . Transportation roller  36  is in the middle of the downstream-side transportation path portion  8 , and transfer pulley  37  is located at the discharge opening to the second check discharge unit  12 . A discharge roller  49  is disposed at the discharge opening to the first check discharge unit  11 . 
     A magnet  51  for magnetizing the magnetic ink characters is disposed between the transportation rollers  31  and  32  in the upstream-side transportation path portion  6 . A front contact image sensor  52  is disposed as the front image scanner, and a back contact image sensor  53  is disposed as a back image scanner, between the transportation rollers  32  and  33 . A magnetic head  54  for magnetic ink character reading is disposed between transportation rollers  33  and  34 . 
     A print mechanism  56  is disposed on the downstream side of the transportation roller  36  in the downstream-side transportation path portion  8 . The print mechanism  56  can move between a printing position applying pressure to the check  4  and a standby position retracted from this printing position by means of a drive motor (not shown in the figure). The print mechanism  56  can also be rendered as a stamp mechanism that is pushed by a plunger to print (stamp) the check  4 . 
     Various sensors for check transportation control are also disposed to the transportation path  5 . 
     A paper length detector  61  for detecting the length of the conveyed check  4  is located near the magnet  51 . 
     A multifeed detector  62  for detecting if two or more checks  4  are being fed together is located between transportation roller  34  and transportation roller  33 . 
     A jam detector  63  is located at a position on the upstream side of the transportation roller  35 . A check is known to be jammed in the transportation path  5  if the jam detector  63  detects a check  4  continuously for a prescribed time or longer. 
     A print detector  64  for detecting the presence of a check  4  printed by the print mechanism  56  is located on the upstream side before the transportation roller  66 . 
     A discharge detector  65  for detecting the discharged check is disposed to the diversion paths  10   a  and  10   b  where the transportation path  5  branches to the first and second check discharge units  11  and  12 . 
     A flapper  66  that is driven by a drive motor not shown to switch the discharge path is disposed on the upstream side of the diversion paths  10   a  and  10   b . The flapper  66  selectively switches the downstream end of the transportation path  5  to the first check discharge unit  11  or the second check discharge unit  12 , and guides the check  4  to the selected discharge unit. 
     The distance from the reading position  54 A of the magnetic head  54  in the transportation path  5  to the printing position  56 A of the print mechanism  56  is greater than the length of the long side (transportation direction) of the check  4  to be scanned in this embodiment of the invention. As a result, when the leading end of the check  4  reaches the printing position  56 A, the trailing end has already passed the reading position  54 A of the magnetic head  54 . The check  4  is therefore sequentially conveyed by the transportation roller  34  and the pressure roller  44 , and by the transportation roller  35  and the pressure roller  45 , as the magnetic head  54  reads the magnetic ink characters. 
     The check  4  is also conveyed sequentially by the transportation roller  33  and pressure roller  43 , by the transportation roller  34  and the pressure roller  44 , and by the transportation roller  35  and the pressure roller  45  as the contact image sensors  52  and  53  image the front and back of the check  4 . 
     Positioning of the Transportation Rollers 
     The positions where the endless belt  23  engages each of the transportation rollers in the check transportation mechanism according to this embodiment of the invention are set as follow. 
     As will be understood from  FIG. 4 , the roller engaging part that is next on the upstream side in the belt drive direction from the belt drive roller engaging part  23 ( 22 ) where the endless belt  23  wraps around the drive pulley  22  is a first roller engaging part  23 ( 35 ) where the endless belt  23  wraps around the transportation roller  35 . The roller engaging part that is next on the upstream side from this first roller engaging part  23 ( 35 ) is a second roller engaging part  23 ( 34 ) where the endless belt  23  winds round the transportation roller  34 . Continuing upstream in the belt drive direction are roller engaging parts  23 ( 33 ),  23 ( 32 ),  23 ( 31 ),  23 ( 37 ), and  23 ( 36 ) at transportation rollers  33 ,  32 ,  31 , transfer pulley  37 , and transportation roller  36 . 
     Transportation Rollers  31  and  32   
       FIG. 5A  shows the part of the check  4  transportation mechanism from the check loading unit  9  to the scanning position  52 A of the front contact image scanner  52 . As shown in this figure two transportation rollers  31  and  32  are located between the scanning position  52 A of the front contact image scanner  52  and the separation pad  16 , separation roller  17 , and retard roller  18 . A check  4  delivered through the separation mechanism is fed first into the nipping part of the transportation roller  31  and the pressure roller  41 , from there to the nipping part of the transportation roller  32  and the pressure roller  42 , and then passed the scanning position  52 A of the front contact image scanner  52 . 
     As shown enlarged in  FIG. 5B , the outside diameter D( 31 ) of transportation roller  31  is slightly greater than the outside diameter D( 32 ) of the downstream transportation roller  32 . A diameter that is approximately 2% to 3% larger is particularly effective. As described above, the endless belt  23  engages transportation rollers  31  and  32  so that the rollers are driven rotationally by a common transportation motor  21 . Both rollers therefore turn at the same angular velocity. The larger diameter upstream transportation roller  31  therefore has a faster peripheral velocity and feeds checks faster than the smaller downstream transportation roller  32 . The same effect can be achieved by driving the transportation roller  31  at a faster angular velocity than the downstream transportation roller  32 . 
     As a result, even if some slipping occurs between this first transportation roller  31  and the check  4  during check transportation due to resistance from the separation mechanism, the part  402  of the check  4  between the first and second transportation rollers  31  and  32  becomes slightly slack as shown in the figure because the first transportation roller  31  feeds the check slightly faster than the second transportation roller  32 . This slack prevents passing feed resistance and variations in the transportation load through the first transportation roller  31  to the second transportation roller  32 . This also inhibits variation in the feed load on the second transportation roller  32  even if the coefficient of friction between the check  4  and the transportation rollers varies. 
     More specifically, variation in slippage between the transportation rollers and the check  4  caused by feed resistance imposed by the separation mechanism and change in the coefficient of friction between the check  4  and the transportation rollers works on the first transportation roller  31  but does not work on the second transportation roller  32 . Variation in the feed load on the second transportation roller  32  and variation in the relay capacity of the first roller are suppressed, and the part  401  of the check  4  that is fed from the transportation roller  32  passes the scanning position  52 A at a constant speed. 
     Control System 
       FIG. 6  is a block diagram showing the control system of the check processing device  1 . The control system of this check processing device  1  includes a control unit  71  that is built around a CPU and has RAM and ROM. The control unit  71  is connected to a host computer system  73  through a communication cable  72 . The computer system  73  has a display unit  73   a  and input/output devices such as a keyboard, mouse, or other operating unit  73   b . Check scanning operation start commands and other commands are input from the computer system  73  to the control unit  71 . 
     When a scanning operation start command is received, the control unit  71  drives the feed motor  19  and the transportation motor  21  to feed the checks  4  one at a time into the transportation path  5  and convey the supplied check  4  through the transportation path  5 . The front image data, back image data, and magnetic ink character data captured from the check  4  by the front contact image sensor  52 , the back contact image sensor  53 , and the magnetic head  54  are input to the control unit  71 . This data is then supplied to the computer system  73  for image processing and character recognition processing. The computer system  73  also determines if the check  4  was scanned normally, and the result is supplied to the control unit  71 . Based on this result the control unit  71  controls driving the print mechanism  56  and the flapper  66 . 
     The control unit  71  controls conveying the check  4  based on the detection signals from the paper length detector  61 , the multifeed detector  62 , the jam detector  63 , the print detector  64 , and the discharge detector  65  that are disposed along the check transportation path  5 . An operating unit  75  including a power supply switch and other switches is also disposed to the case  2  and connected to the control unit  71 . 
       FIG. 7  is a flow chart describing the operation of the control unit  71  of the check processing device  1 . The scanning operation is described next with reference to this flow chart. 
     When the operator inputs a start scanning command from the operating unit  73   b  of the host computer system  73 , the feed motor  19  causes the infeed roller  13  to turn and the pressure member  14  to move and press the checks  4  against the infeed roller  13 . One or more checks  4  are thus advanced by the infeed roller  13 . The separation mechanism (separation pad  16 , separation roller  17 , and retard roller  18 ) disposed to the infeed path  15  then separates and feeds the checks  4  delivered into the infeed path  15  one by one into the transportation path  5  (steps ST 1  and ST 2 ). 
     When the paper length detector  61  detects the leading end of the conveyed check  4 , the transportation motor  21  is driven to rotationally drive the transportation rollers  31  to  36  and the transfer pulley  37 . The supplied check  4  is passed sequentially to the transportation rollers  31  to  36  and transfer pulley  37  and conveyed through the transportation path  5  (step ST 3 ). The front and back of the check  4  are imaged and the magnetic ink characters are read by the front contact image sensor  52 , the back contact image sensor  53 , and the magnetic head  54 , respectively, as the check  4  is conveyed (step ST 4 ). 
     The captured data is then sent through the communication cable  72  to the host computer system  73  (step ST 5 ). The computer system  73  processes the scanned front image, back image, and magnetic ink character data, and determines if the check was read correctly. If the check  4  is fed with the top and bottom upside down, the magnetic ink characters cannot be recognized and a read error results. If the check  4  is fed with the front and back reversed, the magnetic ink character data cannot be acquired and a read error results. If the check  4  is creased, torn, or skewed when fed so that a portion of the magnetic ink characters cannot be read, a read error results. A read error also results if the check amount or other prescribed information cannot be recognized from the front and back image data because the check  4  is creased, torn, or skewed when fed. 
     Referring again to the check processing device  1  side, when the leading end of the conveyed check  4  reaches the printing position  56 A of the print mechanism  56 , the transportation mechanism pauses conveying the check  4  (step ST 6 ). The position of the leading end of the conveyed check  4  is managed by counting the number of steps the transportation motor  21  is driven from when the paper length detector  61  detects the leading end of the check  4 . When conveying the check  4  stops, the check processing device  1  waits for the scanning determination result from the computer system  73  (step ST 7 ). 
     If the received scanning determination result indicates that the check  4  was scanned correctly, conveying the check  4  resumes and the print mechanism  56  is simultaneously moved to the printing position  56 A (steps ST 8  and ST 9 ). The print mechanism  56  prints PROCESSED, for example, on the check  4  as the check  4  is advanced, and the check  4  is directed into the first check discharge unit  11  by the flapper  66  (step ST 10 ). Driving the transportation mechanism stops after the discharge detector  65  detects the trailing end of the check  4  (steps ST 11  and ST 12 ). Feeding and processing the next check  4  then starts. 
     If the received scanning determination result indicates that the check  4  was not scanned correctly (step ST 8 ), conveying the check  4  resumes (step ST 13 ) and the flapper  66  changes position. The print mechanism  56  is held in the standby position and does not print on the check  4 . The check  4  is thus diverted by the flapper  66  and discharged into the second check discharge unit  12  (step ST 14 ). Driving the transportation mechanism stops after the discharge detector  65  detects the trailing end of the check  4  (steps ST 11  and ST 12 ), and the operation for scanning the next check  4  then starts. 
     If the multifeed detector  62  detects a check multifeed state, an interrupt process is executed to immediately stop check transportation, signal a check transportation error to the operator by driving a warning indicator on the operating unit  75 , and then wait until the checks are removed from the check transportation path  5  and the checks are reset to the starting position. A similar interrupt process is executed if the jam detector  63  detects that a check is jammed in the check transportation path  5 . 
     Effect 
     As described above, the check processing device  1  according to this embodiment of the invention disposes two transportation rollers  31  and  32  between the scanning position  52 A of the front contact image scanner  52  and the separation roller  17  and retard roller  18  that create resistance to check transportation and variation in the check transportation load, and drives the upstream side transportation roller  31  faster than the other transportation roller  32  to convey the checks  4  with slack produced between the transportation rollers  31  and  32 . Because there is slack in the part  402  of the check  4  that is between transportation rollers  31  and  32 , transportation resistance imposed by the separation mechanism does not act on the downstream transportation roller  32 . 
     The transportation load that acts on the transportation roller  31  that feeds the check  4  to the scanning position  52 A can thus be reduced, and variation in the transportation load can be suppressed. As a result, there is very little slipping between the second transportation roller and the sheet media even when the transportation speed is fast. The checks  4  can therefore be conveyed passed the scanning position  52 A at a constant speed without increasing the relay capacity of the transportation roller  32 , and a drop in scanning precision can be prevented. A drop in the reading accuracy of the magnetic head  54  that is near the contact image scanner  52  can also be prevented. The reading (scanning) position in this case is at the magnetic head  54 . 
     The invention is described above using a check processing device by way of example, but the invention is not limited thereto and can be used in other media processing devices such as printers and scanners that are used to process checks and other types of sheet media. 
     Although the present invention has been described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims, unless they depart therefrom.