Abstract:
The present invention relates to an automatic document feeder for manipulating and scanning multiple documents, sheets, cards and sheet-like substrates. The present invention is especially suitable for automatic feeding and scanning of a stack of business cards or other material, which is sufficiently rigid. In an embodiment, a card feeder includes a vertically movable pickup roller, a backstop incline, and output rollers. The card feeder uses the pickup roller to separate and push the top card of the stack against a backstop incline. The card slides upwards along the incline until it engages the output rollers, which move the card past a scanner. The present invention relates to embodiments, which transfer an output card to a card scanner using output rollers to push the card toward scanner input rollers. The output rollers and scanner input rollers can be synchronized or the output rollers can freely rotate in one direction after power to a motor driving rotation is cut off. This allows the scanner input roller(s) to pull the card through or by the output roller(s) into the scanner without synchronization during the scanning.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to automatic document feeders and scanners, and in particular those suitable for feeding and scanning multiple cards. 
     Computer printers, scanners, and copiers employ automatic documents feeders to feed multiple sheets of paper from a stack one sheet at a time into position for printing, scanning, copying, and the like. Of course, this saves time hand feeding each sheet. Automatic document feeders such as those found in printers or copier typically have an open tray for holding the stack of paper in horizontal alignment, and a spring-loaded mechanism for keeping the top sheet of the stack at the right height for an extractor mechanism, which pulls each sheet from the stack. 
     The automatic document feeder described is not suitable for handling a stack of cards, however, because of the typical thickness, texture and material of the cards, and particularly those with raised or embossed printing on one or both sides of the card. Such raised or embossed lettering generates a high coefficient of friction between adjacent cards, which results in cards sticking to each other. Thus, the automatic document feeder is unable to pull one card from the stack at a time. Either the document feeder will pull off more than one card or possibly no cards at all. There are systems for scanning and digitizing a single business card such as U.S. Pat. No. 5,604,640, which is incorporated by reference. However, the user must hand feed the system one card at a time. Of course, any of the results are unworkable, for example, for automatically scanning a stack of business cards one might acquire during a business trip. 
     SUMMARY OF THE INVENTION 
     The present invention relates to an automatic document feeder for manipulating and scanning multiple documents, sheets, cards and sheet-like substrates. The document feeder may be in a separate or integrated housing with the scanner. In one embodiment, a card feeder includes at least one pickup roller, which is vertically movable, a backstop incline, and output roller(s). The card feeder separates the top card from the remainder of the card stack by using the pickup roller to push the top card of the stack against a backstop incline. The card slides upwards along the incline until it engages output roller(s), which move the card past a scanner. 
     The present invention relates to mechanisms, which transfer a card across a scanner. The embodiments use one or more output rollers that rotate to push the card toward one or more scanner input rollers. The output roller(s) and scanner input roller(s) can be synchronized or the output roller(s) can freely rotate when the motor driving their rotation is cut off. This allows the scanner input roller(s) to pull the card through or by the output roller(s) into the scanner without synchronization during the scanning process. 
     The invention relates to embodiments of an automatic document feeder, which can be used with scanners. In others, the invention relates to integrated document feeder and scanner systems. In one embodiment, the feeder is a complete unit that provides not only a housing for the card stack, but includes miniature rollers, motors, and assembly for extracting and feeding individual cards from an input card stack. The feeder can be compact and self-contained unit, suitable for use with small hand-held scanners. 
     The present invention is suitable for automatic feeding and scanning of business cards, as well as other substrates, sheets, and materials having a coefficient of friction, which tends to resist separation of the cards from each other yet have sufficient rigidity to separate the top substrate, card or sheet from the underlying stack as described. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an isometric view of an embodiment of a card scanner and card feeder to illustrate the use of the card feeder in feeding a stack of cards. The spacing between feeder and scanner and the thickness of the cards are exaggerated for clarity. 
     FIGS. 2A-2C are cross-sectional views along line X—X in FIG. 1 illustrating one embodiment of the card feeder in operation. 
     FIGS. 3A-3C are cross-sectional views along line X—X in FIG. 1 illustrating another embodiment of the card feeder in operation. 
     FIG. 4 illustrates a portion of the card feeder including the card input platform and the backstop incline. In these embodiments, the backstop incline can be set at various angles depending on requirements and the type of substrate being scanned. 
     FIG. 5 illustrates one system of moving a card from a card feeder into a card scanner that has a single roller above a scan module. 
     FIG. 6 illustrates another system of moving a card from a card feeder into a card scanner that has a scan module above a single roller. 
     FIG. 7 illustrates another system of moving a card from a card feeder into a card scanner that has multiple rollers. 
     FIG. 8 shows a cross-sectional view of a combined housing of a card scanner and feeder device. 
     FIG. 9 shows a cross-sectional view of a combined housing of a card scanner and feeder device. 
     FIG. 10 shows a cross-sectional view of a combined housing of a card scanner and feeder device. 
     FIG. 11 shows a gear train and pulley system for driving a pickup roller using a motor. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following description includes the best mode of carrying out the invention. The detailed description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the claims. 
     FIG. 1 illustrates an embodiment of a card scanner  10  and a card feeder  30 . The spacing between the card scanner  10  and the card feeder  30  is exaggerated for clarity. The card feeder  30  has a feeder entrance  44  into which preferably a stack of cards can be inserted. The card feeder  30  sequentially lifts each card, beginning from the top card  50  of the stack and ejects it through an output of the feeder back surface  31 . The output card  60  is then fed to input  20  of the card scanner  10  to scan the card. Typically, a suitable conventional locking mechanism will hold the card scanner  10  and card feeder  30  adjacent to each other for proper alignment. In one embodiment, the back surface  31  of the card feeder touches or is held in close proximity to the scanner front surface  18 . In another set of embodiments, a combined housing holds the card scanner  10  and the card feeder  30 . 
     FIGS. 2A-2C are cross-sectional views along line X—X of FIG. 1 illustrating the operation of one embodiment of the card feeder  30 . Referring to FIG. 2A, the card feeder  30  includes an upper housing  32  and a lower housing  46  (collectively called “the housing”). The upper housing  32  and lower housing  46  are convenient structures for holding and positioning the moving parts and for rigidity, but not essential to the invention. Attached to the upper housing  32  is a swing arm  36 , which pivots about a swing arm axle  38 . A pickup roller  34  of rubber or another material capable of gripping the cards is rotatably attached to the lower end of the swing arm  36 . A conventional DC motor (not shown) drives the pickup roller  34  by means of a conventional pulley and belt arrangement or by a gear train (see FIG.  11 ). This motor termed the pickup motor can be a stepper or a DC motor. The pickup roller  34  rests on the top card  50  of the input card stack. The card stack rests on card input platform  47 , which can be horizontal or inclined downwards as shown in FIG.  2 A. The front edge of each card of the stack leans against the backstop incline  48 . The backstop incline  48  is set up such that the top of the incline leads into the nip defined between the upper output roller  40  and lower output roller  42 . In one embodiment, the system provides a second conventional motor (also not shown) to drive the output rollers  40  and  42  independently from the pickup roller  34 . This second motor will be referred to as the output motor to distinguish it from the pickup motor. 
     In operation, the card feeder  30  moves the top card  50  from the input card stack to the feeder exit  45 . The sequence of the operation is shown in FIG. 2A, FIG. 2B, and FIG.  2 C. Referring to FIG. 2A, the top card  50  rests on the second card  51 , and the front edge of the top card  50  leans against the backstop incline  48 . The pickup roller  34  rests on the top card  50 . Power applied to the pickup motor drives the pickup roller  34 , and causes it to rotate in a clockwise direction. Concurrently or shortly after, power is applied to the output motor to drive the output rollers  40  and  42 , causing the top output roller  40  to rotate clockwise, and the lower output roller  42  to rotate counter-clockwise. 
     Referring to FIGS. 2A-2B, as the pickup roller  34  rotates clockwise, the traction of the pickup roller  34  on the top card  50  will push the top card  50  forward against the backstop incline  48 . This will force the front edge of the top card  50  to slide upwards along the backstop incline  48  as shown in FIG.  2 B. As the top card  50  slides upwards, it will separate from the second card  51 , which due to its weight, will tend to remain on the input card stack. As the pickup roller  34  rotates, the front edge of the top card  50  will progressively slide up along the backstop incline  48 . As the front edge of the card slides up, the center portion of the top card  50 , which is semi-rigid will move upwards, lifting the pickup roller  34  upwards with it. The pickup roller  34  is mounted to the swing arm  36 , which is rotatably attached to the upper housing  32  in a way that allows it to move vertically as the top card  50  rises. 
     Referring to FIG. 2C, the top card  50  continues to slide forward and upward on the backstop incline  48  until the front edge of the card enters the nip between output rollers  40  and  42 . The output rollers  40  and  42  grip the front edge of the card and push it out through the feeder exit  45 . In one embodiment, as the top card  50  moves through the feeder exit  45 , a sensor (not shown) detects the top card  50  and shuts off power to the pickup motor driving the pickup roller  34 . The output motor driving output rollers  40  and  42  continues to operate, however, and pushes the top card  50  through the feeder exit  45  into the card scanner  10  as shown in FIG.  1 . 
     FIG. 3A is a cross-sectional view of another embodiment of the card feeder  30  along section view line X—X in FIG.  1 . This embodiment is similar to the previous embodiment shown in FIG. 2A, except in the way in which the pickup roller  34  is mounted. Referring to FIG. 3A, the pickup roller  34  slides freely on a vertical roller guide  39  which is mounted to the upper and lower housing  32  and  46 . The pickup roller  39  moves freely along the roller guide  39 , and rests on the top card  50  of the input card stack. The principle of operation of the card feeder in this embodiment shown in FIGS. 3A-3C is the same as that of the previous embodiment shown in FIGS. 2A-2C. 
     Referring to FIG. 3A, as the pickup roller  34  rotates in a clockwise direction, it pushes the front edge of top card  50  forward against the backstop incline  48 . This causes the front edge of top card  50  to slide upwards along the incline. The second card  51  will remain on the input card stack due to its weight. The upward movement of the top card  50  causes the pickup roller  34  (FIG. 3B) to slide upwards along the roller guide  39 . The top card  50  continues to slide up the backstop incline  48  until it reaches the nip between the output rollers  40  and  42  (FIG.  3 C). The output rollers  40  and  42  grip the card and push it out through the feeder exit  45 . As the card enters the feeder exit  45 , a sensor (not shown) located in the feeder exit  45  detects the card and shuts off power to the pickup motor driving the pickup roller  34 . The output motor driving output rollers  40  and  42  continues to operate and pushes the card through the feeder exit  45  into a card scanner such as that shown in FIGS.  1  and  5 - 10 . 
     The optimum angle of incline of the backstop incline  48  depends on the thickness and flexibility of the card material to be fed through the card feeder  30 . Referring to FIG. 4, the angle is measured from the vertical reference line  100  to the backstop incline  48  in a clockwise direction. For business cards, a desirable range of angles for the incline is anywhere between about 125 to 179 degrees. However, the angle of incline used is not essential to the invention. It is understood that one of ordinary skill could determine the angle of incline to use after review of the specification given the stock, grade, lettering, raised or embossed, and texture of card or substrate being fed and scanned. The dotted line  49  illustrates one lower position for the backstop incline  48 . 
     FIG. 5 shows an embodiment of a mechanism and method of feeding an output card  60  from the feeder exit  45  into the card scanner  10 . The elements of the card scanner  10  are the input roller  4 , the scanning module  2 , which may include a scanning element inside a housing, and a scanning glass  3 . The input roller  4  may be mounted above the scanning module  2  as shown in FIG. 5, or below the scanning module  2 , as shown in FIG.  6 . In an embodiment, a sensor (not shown in figure) is disposed in front of the input roller  4  to detect the presence of an output card  60 . The elements of the card feeder  30  are as previously described. 
     Referring to FIG. 5, the elements of the card feeder  30  for moving the output card  60  into the card scanner  10  are the upper output roller  40  and the lower output roller  42 . These two rollers are preferably spring mounted in the upper housing  32  and lower housing  46  in such a way that the rollers touch along a parallel axis. The rollers may be separated slightly by a card passing between them. The output motor driving these two output rollers  40 ,  42  is coupled to the rollers by means of a conventional gear drive that allows the rollers to rotate freely in one direction even when the motor is stopped. Functionally, this acts much like a ratchet wrench, which is driven in one direction of rotation and spins free in the other. The torque generated by the motor can be supplied to either the upper output roller  40  or the lower output roller  42 , or both of the output rollers  40  and  42  simultaneously. 
     In one embodiment, the output motor can drive the lower output roller  42  in a counter-clockwise direction. The upper output roller  40  can be a non-driven freely rotating roller, which provides pressure on the output card  60  to ensure firm contact between the output card  60  and the lower output roller  42  as the card is pushed forward by the driven lower output roller  42 . The lower output roller  42  is coupled to the motor in such a way that the roller  42  can continue to rotate freely in a counter-clockwise direction when the motor is stopped. 
     In another embodiment, the output motor drives the upper output roller  40  in a clockwise direction and the lower output roller  42  is a freely rotating roller. The upper output roller  40  is coupled to the motor in such a way that it can continue to rotate freely in a clockwise direction when the motor is stopped. 
     In another embodiment, torque from the motor is supplied simultaneously to both the upper and lower output rollers  40  and  42 . When the motor driving the rollers is stopped, the coupling to the rollers is such that the upper output roller  40  can continue to rotate freely in a clockwise direction, and the lower output roller  42  can rotate freely in a counter-clockwise direction. 
     FIGS. 5 and 6 show the method of moving the card from the card feeder  30  to the card scanner  10 . Referring to FIG. 5, the input roller  4  is initially stationary. The output motor (not shown) turns the output rollers  40  and/or  42 , which moves output card  60  in direction  80  until it lodges firmly into the nip between the input roller  4  and the scanning glass  3 . The output motor is then stopped. Next, the scanner motor turns the input roller  4 , which pulls the card across the scanning glass for the scanning process. Although the output motor is stopped, the output rollers  40  and  42  continue to rotate freely as output card  60  is pulled out of the card feeder  30  into the card scanner  10  by the rotating input roller  4 . In another mode of operation, the output motor does not stop but continues to operate as the output card  60  engages input roller  4 , and the output rollers  40  and  42  rotate in synchronization with the input roller  4 . 
     In FIG. 7, the card scanner  10  includes a pair of input rollers  4  and  5 , instead of the single input roller  4  of the card scanner  10  shown in FIG. 5. A pressure plate  8  is placed above the scanning module  2  to keep the card  60  in contact with the scanning module  2  during the scanning. The method of moving the card  60  from the card feeder  30  to the card scanner  10  is similar to that of FIG.  5 . Referring to FIG. 7, the output rollers  40  and  42  move the card  60  into the nip between input rollers  4  and  5 . The output motor is then stopped. Next the input rollers  4  and  5  of the card scanner  10  rotate, pulling the card  60  from the card feeder  30  and pushing it across the scanning module  2 . Eject rollers  6  and  7  grip the card  60  as it moves across the scanning module  2 , and moves it out of the card scanner  10 . In another mode of operation, the output motor does not stop, but continues to operate as the output card  60  engages input rollers  4  and  5 , and the output rollers  40  and  42  rotate in synchronization with the input rollers  4  and  5 . 
     The parts of the card scanner  10  and card feeder  30  previously described and shown in FIGS. 5-7 can be installed in a combined housing go as shown in FIG.  8 . The backstop incline  48 , and the output rollers  40  and  42  of the combined housing go perform the same functions and operate in the same way as the corresponding parts in the card feeder  30  shown in FIGS. 5-7. To illustrate one of those embodiments, referring to FIG. 8, the output rollers  40  and  42  rotate in synchronized speed with the upper and lower eject rollers  6  and  7 . The output rollers  40  and  42  move card  60  across the scanning module  2 . The upper and lower eject rollers  6  and  7  grip the card as it moves across the scanning module and push it out of the combined housing go. 
     FIG. 9 shows another combined housing  92  for the card scanner  10  and card feeder  30 . FIG. 10 shows another combined housing  94 . Similar to the previous combined housing go (FIG.  8 ), the backstop incline  48 , and the output rollers  40  and  42  of these combined housings perform the same functions and operate in the same way as the corresponding parts in the card feeder  30  in FIG.  5 . Referring to FIG.  9  and/or FIG. 10, in one mode of operation, the input roller  4  is initially stationary. The output rollers  40  and  42  move the card  60  into the nip between the input roller  4  and the scanning module  2 . The motor driving the output rollers  40  and  42  then stops. Next, power is applied to the input roller  4 , which rotates and moves the card  60  completely across the scanning module  2  and out of the combined housing  92  (or  94  in FIG.  10 ). In another mode of operation, the output motor does not stop but continues to operate as the output card  60  engages input roller  4 , and the output rollers  40  and  42  rotate in synchronization with input roller  4 . 
     FIG. 11 illustrates an embodiment of a gear train and pulley system for driving a pickup roller  34  using a pickup motor (not shown). The pickup roller  34  is mounted on a swing arm  36 . The upper end of the swing arm  36  is pivoted at the swing arm axle  38 , and allows the arm to rotate freely about the swing arm axle  38 . Gear  126  is fixed to a driver wheel  130  and both rotate in synchronization about the swing arm axle  38 . Pickup roller  34  is fixed to a roller wheel  132  and both rotate in synchronization about the pickup axle  35 . As power is applied to the pickup motor (not shown), a motor pinion  120  transfers torque to gear  126  by coupling with gear  122  and gear  124 . This causes the driver wheel  130  to rotate, and torque is transferred to the roller wheel  132  by means of the pulley belt  140 . The resulting torque on the roller wheel  132  causes it to rotate, which in turn rotates the pickup roller  34 .