Abstract:
A media feed system with a self-contained propulsion system is provided. A singulator is used to feed a single media piece and a sensor determined when to disengage propulsion.

Description:
BACKGROUND OF INVENTION  
         [0001]    The embodiments described herein relate generally to media feeding systems and more specifically to systems and methods for feeding variable size media to a printer.  
           [0002]    Certain printers are known that have several delivery paper feed paths for feeding paper into a print engine feed path. For example, certain printers have a paper source under the horizontal print engine such that paper is pulled from the source tray and curled around the back of the printer and then fed into the horizontal print engine feed path. Some printers utilize more than one paper tray in order to accommodate different paper sizes. Such a design minimizes the amount of area of a surface required for the footprint at the expense of using more space in a vertical direction. Conventional printers often provide a paper feed bypass tray that provides paper at a close to horizontal feed path to the print engine feed path. A bypass feed path does not necessarily have to be horizontal to the print engine feed path. An inkjet printer has a generally small print engine band that requires the paper be parallel to the print head. An example of a description of a printing feed mechanism that incorporates a horizontal envelope feeder is shown in U.S. Pat. No. 4,733,310 issued Mar. 22, 1988 to Kapp, et al.  
           [0003]    As can be appreciated, conventional paper trays feed paper from the top of the stack of paper and must be removed from the printer in order to feed additional paper into the tray.  
         SUMMARY OF INVENTION  
         [0004]    In one embodiment, a media feeder includes a propulsion source and singulator to feed single media items from a stack.  
           [0005]    In another embodiment, the media feeder includes a power source, receives a feeder control signal and feeds media from the bottom of a stack.  
           [0006]    In another embodiment, the media feeder includes at least two media sources and a control mechanism to control which source to utilize for a subsequent feed. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0007]    [0007]FIG. 1A is a side view of a media feeder according to an embodiment of the present application.  
         [0008]    [0008]FIG. 1B is a side view of propulsion system for a media feeder according to an embodiment of the present application shown in FIG. 1A.  
         [0009]    [0009]FIG. 2 is a top view of a media feeder according to an embodiment of the present application shown in FIG. 1A.  
         [0010]    [0010]FIG. 3 is a top view of a media feeder according to a second embodiment of the present application.  
         [0011]    [0011]FIG. 4 is a top view of a media feeder according to a third embodiment of the present application.  
         [0012]    [0012]FIG. 5 is a side view of a media feeder according to a fourth embodiment of the present application.  
         [0013]    [0013]FIG. 6 is a side view of a media feeder according to a fifth embodiment of the present application.  
         [0014]    [0014]FIG. 7 is a flowchart of a media feed process according to another embodiment of the present application. 
     
    
     DETAILED DESCRIPTION  
       [0015]    The present application describes embodiments of a system and method for feeding media. The embodiments are illustrative and where alternative elements are described, they are understood to fully describe alternative embodiments without repeating common elements. The processes described provide useful results including but not limited to increasing print accuracy, optimizing printer throughput and simplifying maintenance. The embodiments discussed herein apply to an envelope feeding system for an inkjet printer for illustrative purposes. For illustrative purposes, an inkjet printer having a horizontal bypass feed port in the rear of the unit is the target device. Of course the target may be the main paper path of the device as well and may load a traditional paper source for a printer. Similarly, a Laser printer or other device requiring sheet fed media may be used as an appropriate target device.  
         [0016]    As can be appreciated, moderately priced inkjet printers may not include robust media feed systems. They typically incorporate one media tray that has a moderate capacity. When a paper tray is utilized, the printer feeds sheet from the bottom of the stack and the printer must be interrupted to load additional sheets into the paper tray. Similarly, the conventional feed mechanisms are passive devices without a separate source of media propulsion.  
         [0017]    The embodiments described herein utilize a media feeding system that is preferably configured to feed standard number 10 envelopes in a face up orientation with the bottom major edge fed first into the feed path. Such envelopes are 4 and one-eighth inch on the minor edge and 9 and one half inch on the major edge. Other substrates and other sizes of paper and envelopes may be processed, but the number 10 envelope is used for illustrative purposes. In a later embodiment, two envelopes are simultaneously fed along their minor edge such that a number 9 and a number 11 envelope may be simultaneously fed to a printer. Components of media feed mechanisms and singulators are known and not described in detail in this application. However, a fourth embodiment described below uses a single feed mechanism to feed from two separate media sources.  
         [0018]    Referring to FIG. 1A, a first embodiment is shown. A media feeder  100  is described for singulating and feeding a media piece  10  from a stack of media  1 . The media piece will be fed until a resistance is sensed in forcing the paper through the feed path using a slip clutch. As can be appreciated, if the media feeder is forcing a sheet of paper into the bypass feed rollers of a printer when the bypass feed rollers are not moving, the sheet of paper will stop at that point until the bypass feed rollers start moving. In an alternative embodiment, the media feeder does not sense resistance in the fed media, but feeds the media on a predetermined schedule or according to a command response from an external device. In another alternative embodiment, the media feeder does not sense resistance in the fed media, but feeds the media on a predetermined schedule or according to a command response from an external device. A controller (not shown) may be used to determine a feed schedule or interpret feed commands from an external device.  
         [0019]    The media feeder  100  includes a singulator  110  that is adjustable to the thickness of the media such that a singulating clearance will ensure that only one sheet of 10 is fed at a time. The media may be an envelope or sheet of paper or other media and may be interchangeably used in the description below. For example, singulator bar  112  is used to create a feed gap. The singulator bar is attached to the frame of the singulator  110  that is adjustable using knob  114  attached to the frame  102  of the media feeder  100 . The frame  102  is fully adjustable along all axes and may be moved from side to side. Adjustable supports  104  are on each side of frame  102  and adjustable supports  106  are on each side of frame  102 . Roller  140  feeds the media from feed tray system  120 . The feed tray system  120  is a bin feeder in that it can be fed from the top while the unit is operating. The feed tray system  120  has a feed deck  126  for holding the media and is adjustable along a feed deck height adjuster frame  124  that is connected to the frame  102 . Knob  122  is used to adjust the height of the feed deck  126  by moving the deck to a new notch in the feed deck height adjuster frame  124 .  
         [0020]    Referring to FIG. 1B, the propulsion system  150  is described. Power is obtained through a line connection to power connector  170  that supplies power to a power supply (not shown). The controller (not shown) controls the AC electric motor  158  in the propulsion system  150 . The motor  158  may be reversible. Electric motor  158  drives wheel  156  that drives belt  152  that drives wheel  154 . Wheel  154  drives roller  140  and uses a slip clutch to sense a force feedback on the media. The media is fed along adjustable guide  149  that is used to align the fed media with the target device. The roller  140  may be disengaged from the drive when the sheet is fed into the ready position so that the target device may easily pull the remainder of the sheet from the stack. Alternatively, the roller  140  may be engaged to feed the rest of the sheet.  
         [0021]    Referring to FIG. 2, the feed deck  126  is shown from the top to illustrate the ability to accommodating different media sizes. A guide rail  128  may be used to align the media. In alternatives, the media may be registered to either side rail  127 ,  129  or center justified using two adjustable guide rails (not shown). The roller system  140  includes multiple rollers  142 ,  144 ,  146 ,  148 . In an alternative a single full width roller is used.  
         [0022]    In an alternative embodiment, a DC electric motor may be used. As can be appreciated, other forms of propulsion may be employed including energy stored in a spring. Similarly, media biasing systems are known and not described in detail. A spring-loaded magazine may be used and a gravity feed mechanism may be used.  
         [0023]    Referring to FIG. 3, a second embodiment is described. The media feeder  200  has an electric motor  258  that drives roller system  240  to simultaneously feed media from two different stacks enclosed by a first set of rails  228 ,  229  and a second set of rails  226 ,  227 .  
         [0024]    Referring to FIG. 4, a third embodiment is described. The media feeder  300  has an electric motor (not shown) that drives roller system  340  to feed media from a movable stack  320  that may be automatically moved from side to side and vertically using drive  390  under the control of a controller (not shown).  
         [0025]    Referring to FIG. 5, a fourth embodiment is shown. A media feeder  500  is described for singulating and feeding a media piece  10  from a stack of media  1  and for singulating and feeding a media piece  20  from a second stack of media  2 . The media piece  1 ,  2  will be fed until a resistance is sensed in forcing the paper through the feed path using a slip clutch. As can be appreciated, if the media feeder is forcing a sheet of paper into the bypass feed rollers of a printer when the bypass feed rollers are not moving, the sheet of paper will stop at that point until the bypass feed rollers start moving. In an alternative embodiment, the media feeder does not sense resistance in the fed media, but feeds the media on a predetermined schedule or according to a command response from an external device. In another alternative embodiment, the media feeder does not sense resistance in the fed media, but feeds the media on a predetermined schedule or according to a command response from an external device. A controller (not shown) may be used to determine a feed schedule or interpret feed commands from an external device. The media being fed  1 , 2  is directed using adjustable guide  549  and adjustable guide/singulator  548 . The guides direct the direction of the media that is being fed into the target device.  
         [0026]    The media feeder  500  includes a first singulator  510  that is adjustable to the thickness of the media such that a singulating clearance will ensure that only one sheet of media is fed at a time. For example, singulator bar  512  is used to create a feed gap. The singulator bar is attached to the frame of the singulator  510  that is adjustable using knob  514  attached to the frame  502  of the media feeder  500 . The frame  502  is fully adjustable along all axes and may be moved from side to side. Adjustable supports  504  are on each side of frame  502  and adjustable supports  506  are on each side of frame  502 . Roller  540  feeds the media from feed tray system  520 . The feed tray system  520  is a bin feeder in that it can be fed from the top while the unit is operating. The feed tray system  520  has a feed deck  526  for holding the media and is adjustable along a feed deck height adjuster frame  524  that is connected to the frame  502 . Knob  522  is used to adjust the height of the feed deck  526  by moving the deck to a new notch in the feed deck height adjuster frame  524 .  
         [0027]    The propulsion system obtains power through a line connection to power connector  570  that supplies power to a power supply (not shown). The controller (not shown) controls the AC electric motor  558  in the propulsion system. The motor  558  is reversible. Electric motor  558  drives wheel  556  in a first direction that drives a belt (not shown) that drives roller  540  in a first direction and uses a slip clutch to sense a force feedback on the media. The media is fed along adjustable guide  549  that is used to align the fed media with the target device.  
         [0028]    Alternatively, the controller (not shown) reverses the direction of the motor to move roller  540  in the opposite direction to feed media  20  from stack  2  using singulator/guide  548 . Deck  520  prevents the top stack media  1  from being fed back into the media feeder  500 . A spring mechanism  590  feeds media stack  20  up to the roller  540 .  
         [0029]    As can be appreciated, a mechanical switch could be used to select the stack to feed from. In an alternative, a set sequence can be loaded into the media feeder  500  and used to select the source of media. Additionally, an external control signal may be utilized to control the feed source, or the system may feed media at a predetermined rate.  
         [0030]    Referring to FIG. 6, a fifth embodiment is shown. A media feeder  600  is described for singulating and feeding a media piece  10  from a stack of media  1 . The media piece will be fed until the system determines it should stop. The media feeder  600  uses a slip clutch to sense a resistance when the paper hits a stop. Additionally, a paper position sensor  692  detects if paper is in the exit path. Wheel  692  is used as a sensor and guide and housing  690  includes an optical media sensor. A controller (not shown) is used to determine when to engage drive rollers  640 ,  644  using motor  658  and belt  652  with clutches (not shown).  
         [0031]    The media feeder  600  includes a singulator  610  that is adjustable to the thickness of the media such that a singulating clearance will ensure that only one sheet of is fed at a time. For example, singulator bar  612  is used to create a feed gap. The singulator bar is attached to the frame of the singulator  610  that is adjustable using knob  614  attached to the frame  602  of the media feeder  600 . Rollers  640 ,  644  feed the media from feed tray system  620 . The feed tray system  620  is a bin feeder in that it can be fed from the top while the unit is operating. The feed tray system  620  has a feed deck  626  for holding the media and is adjustable along a feed deck height adjuster frame and knob  623  that is connected to the frame  602 . Knob  622  is used to adjust the height of the feed deck  626  by moving the deck  626  to a new notch in the support. Deck extender  625  is controlled using knob  627 . The feeder frame  696  is connected to frame  602 .  
         [0032]    Power is obtained through a line connection to power connector  670  that supplies power to a power supply (not shown). The controller (not shown) controls the AC electric motor  658  in the propulsion system. The motor  658  may be reversible. Electric motor  658  drives wheel  656  that drives belt  652  that drives rollers  640 ,  644  using tensioner  642  that is used to sense a force feedback on the media. The media is fed along output deck  699  that is used to align the fed media with the target device.  
         [0033]    The second roller  644  may be disengaged from the drive when the sheet  10  is fed into the ready position so that the target device may easily pull the remainder of the sheet from the stack while the first roller  640  is ready to start feeding another sheet  10 . Alternatively, the roller  140  may be engaged to feed the rest of the sheet.  
         [0034]    The system includes sensors (not shown) to sense carriage speed and position.  
         [0035]    Referring FIG. 7, another embodiment is shown. The process for feeding  700  starts a media feed. In step  710 , the system receives a media feed indication. In step  720 , the system starts a propulsion system to singulate a media piece. In step  730 , the system senses a stop and stops the propulsion. In step  740 , the system disengages the propulsions source and ends in step  750 .  
         [0036]    Power supplies are well known and not described in detail. As can be appreciated, a battery or electrical energy storage device may be utilized as a source of electrical power. Similarly, controllers are well known and not described in detail. In one embodiment, an 8051 controller and support circuitry is utilized.  
         [0037]    The above specification describes a new system and method for feeding media that is useful and may increase throughput speed and/or accuracy of the system.  
         [0038]    The described embodiments are illustrative and the above description may indicate to those skilled in the art additional ways in which the principles of this invention may be used without departing from the spirit of the invention. Accordingly the scope of the claims should not be limited by the particular embodiments described.