Abstract:
The Media Handling Mechanism application to Media Handling devices includes pickup roller, cam and feed roller. The feed roller feeds the media, then the pickup roller presses the media with friction pad, and picks up the media by rotating motion. The Media Handling Mechanism applies to kinds of the media of different size and thickness. This simple design not only decreases the cost, but also the working efficiency is improved.

Description:
FIELD OF THE INVENTION  
         [0001]    The invention relates to a handling mechanism for use in media handling devices, particularly a media handling mechanism for conveying media.  
         BACKGROUND OF THE INVENTION  
         [0002]    In office environment of businesses, paper is widely used for mails and other documents. That often needs printing, copying or faxing. The general office equipment and business machines, such as copiers, inkjet printers, laser printers, fax, and scanners need to put paper in the machine. As a lot of paper is used, printing quality and operating efficiency have become a key focus research and development of the business machine manufacturing industry.  
           [0003]    One of the areas of improvements is media handling operation. Business machines now on the market have many different types of media feeding apparatus. In general, they can be grouped in an L-type path method and an U-type path method. FIG. 1 illustrates the conventional paper pickup apparatus. It has a media tray  300  to store paper  90 . There is a pick-up roller  200  to contact the paper  90 . The pick-up roller  200  rotates and has friction to move the paper  90  horizontally. One side of the media tray  300  has a snubber  310  to block the movement of the paper  90 , and make the paper buckle and deform. One side of the paper  90  is pushed by a returning force and springs out of the media tray  300 . Thus the paper may be conveyed as desired. This is the U-type path method (Snubber type).  
           [0004]    Another paper conveying method is friction retard, shown in FIG. 2, that is the second type. It also has a media tray  300  to store paper  90 . A pick-up roller  400  is located and next to the upper side of the media tray  300 , and is connected to a friction pad  500  in normal conditions. The pick-up roller  400  rotates to move the paper  90 . The pick-up roller  400  and the friction pad  500  operate in a cooperative way to clip the paper  90  for conveying.  
           [0005]    However, the commonly used paper conveying methods mentioned above are not suitable for moving paper or other media of a greater thickness such as transparency films, envelops, or the like. As those media(i.e. papers) have a greater rigidity and are less likely to be deformed or buckled, feeding paper or other media is more difficult or impossible. In addition, angle bending or folding is prone to happen. Hence conventional paper handling mechanisms are only applicable to paper of limited specifications that have specific sizes and thickness.  
           [0006]    Therefore the industry has developed another type of paper conveying method. For instance, EP patent No. 816,107, entitled “Paper feeding apparatus and printer” employs an idle roller to control the gap of the pickup roller. But it cannot effectively control the gap required by the paper. U.S. Pat. No. 6,146,036, entitled “Rotatable cam device for a pickup roller of a printer” discloses another type of paper conveying method. It has a plurality of sprockets engaging with the pick-up roller to clip and transport the paper. While it can convey paper, its structure is very complicated. The production cost is high and maintenance is difficult.  
           [0007]    The two exampled mentioned above are the L-type path method. Although they have the advantage of lifting the limitation of paper size and thickness, they still have the following drawbacks like all conventional media handling mechanisms: 1. A multi-feed problem, i.e. more than one piece of paper is picked up during the handling process. 2. Mis-feeding, i.e. no paper is picked up and fed due to different paper thickness. 3. Paper jamming, i.e. paper is jammed and blocked due to different sizes and thickness of the paper, resulting in interruption of paper conveying.  
         SUMMARY OF THE INVENTION  
         [0008]    The object of the invention is to solve the foregoing problems. The invention provides a media handling mechanism that has a conveying unit rotationally. The conveying unit has a cam to stop feeding of media held in a media tray, and generate a gap to put a predetermined number of the paper in the conveying unit. Then a pick-up roller pushes a friction pad to clip the paper, and rotates to move the paper into a business machine for printing or scanning operations. The media handling mechanism of the invention has a simple structure, and is adaptable to media of different specifications. It can effectively prevent the problems of multi-feeding and paper jamming. The simple structure reduces production costs and effectively increases operation efficiency. In addition, media of various sizes and thickness can be used. Thus utilization is more flexible.  
           [0009]    The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    [0010]FIG. 1 is a schematic view of a first type of conventional media handling devices.  
         [0011]    [0011]FIG. 2 is a schematic view of a second type of conventional media handling devices.  
         [0012]    [0012]FIG. 3 is a schematic view of the media handling mechanism of the invention.  
         [0013]    FIGS.  4  to  8  are schematic views of the media handling mechanism of the invention in various operating conditions. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0014]    Refer to FIG. 3 for the media handling mechanism of the invention. It mainly includes a conveying unit  10  and a friction pad  40 . The conveying unit  10  includes a pick-up roller  20  and a cam  30  that are coupled together and rotationally installed in a media handling device. A driving module such as a motor (not shown in the drawing) is provided to connect the conveying unit  10  to provide kinetic energy required in the rotational movements of the conveying unit. The pick-up roller  20  and the top surface of the friction pad  40  are at a predetermined distance. The top surfaces of both are formed in arched shapes to avoid damaging the surface of the media  90  during operations (will be discussed later). The coupled pick-up roller  20  and the cam  30  are formed in an integrated manner. They are shown in a separated fashion in the drawing, to explain the movements of the conveying unit  10 . While they are separated and independent, it is by no means a restriction.  
         [0015]    The friction pad  40  is a flat board made of rubber. It is located on a lower side of the conveying unit  10 . There is a first elastic element: a first spring  41 , which has one end, fastening to a loading base  100 , and another end connecting to the friction pad  40 . In normal conditions, the first spring  41  provides an elastic force to press the friction pad  40  to allow the friction pad  40  mounting on the loading base  100  in a biased manner, at a predetermined angle. A media tray  70  is located on one side of the loading base  100  for storing media  90 . There is a lifting plate  71  located on one side of the media tray  70 . A second elastic element, a second spring  72 , is located between the media tray  70  and the lifting plate  71 , creating an elastic force, to lift the lifting plate  71 . A realigning hook  50  is pivotally hinged on the bottom side of the conveying unit  10  to block the media  90  held in the media tray  70  from feeding in normal conditions. A driven cam  60  is located on one side of the realigning hook  50  to selectively press the realigning hook  50  and rotate the realigning hook  50  to a predetermined angle for the media  90 , to be fed into the conveying unit  10 .  
         [0016]    By means of the construction set forth above, operations of the invention will be discussed as follows by referring to FIGS.  4  to  8 . Referring to FIG. 4, first, the realigning hook  50  realigns the media  90  in normal conditions. The driven cam  60  rotates for a predetermined angle to move the realigning hook  50  rearwards and slide the media  90  downwards. Next, the conveying unit  10  rotates, the cam  30  is driven to turn downwards to contact and press the friction pad  40 . The cam  30  at this stage is to replace the function of the realigning hook  50  to stop the media  90  from sliding down, and also prevent the media  90  from being fed. In the mean time, a predetermined gap is formed to use a selected amount of media and generate a separation effect for the media  90 . The media  90 , located on the top layer, enters. Referring to FIG. 5, the second spring  72  provides an elastic force to push the lifting plate  71  upwards for a predetermined distance and make the media  90  located on the top layer go between the friction pad  40  and the pick-up roller  20 . The conveying unit  10  continues moving, to drive the cam  30  and the pick-up roller  20 , rotating for a predetermined angle. The cam  30  is no longer in motion with the friction pad  40 , instead, the pick-up roller  20  presses the friction pad  40  and clips the media  90  out of the media tray  70 . Referring to FIG. 6, the pick-up roller  20  continuously rotates to convey the media  90  to the loading base  100 . Referring to FIG. 7, one side of the loading base  100  has a media feeding module which has a feed roller  80  to feed the media  90 , to move continuously and avoid paper jam, and control compression of the second spring  72 , to lower the lifting plate  71  such, that the media  90  is moved back into the media tray  70 . The conveying unit  10  completes the operations and returns to the normal condition without being connected to the friction pad  40  and the media  90 . Finally, as shown in FIG. 8, the driven cam  60  rotates to a predetermined angle to drive the realigning hook  50 , and the media  90  is moved back to the media tray  70  to prevent multi-feeding.  
         [0017]    The previous description has clearly shown the operational relationship between the conveying unit  10  and the friction pad  40 . Separating operations of the media  90  in the media tray  70  are also described The cam  30  controls the gap to receive a predetermined number of the media  90 . The pick-up roller  20  feeds the media  90 . The mechanism is simply constructed. It not only reduces production cost, it also separates the media accurately and increases operation efficiency. Moreover, the techniques disclosed in the invention may also be adapted to handle media of different sizes and thickness to satisfy the user&#39;s requirements.  
         [0018]    While the preferred embodiment of the invention has been set forth for the purpose of disclosure, modifications of the disclosed embodiment of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments not departing from the spirit and scope of the invention.