Patent Publication Number: US-2004041339-A1

Title: Printer having paper guide structure to unjam paper in a printer

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001] This application claims the benefit of Korean Patent Application No. 2002-52924, filed on Sep. 3, 2002 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002] 1. Field of the Invention  
       [0003] The present invention relates to a printer having a paper guide structure which can solve a paper jam problem.  
       [0004] 2. Description of the Related Art  
       [0005] As shown in FIG. 1, a door  11  is installed in a printer or copier to be capable of being opened or closed so that a user can see the inside of a main body  10  if necessary. The door  11  is needed not only to repair the inside of the printer but also to pull up a paper S which is jammed in the middle of a transfer path after being supplied from a cassette  12  during printing. That is, when a paper jam occurs during the printing, the user opens the door  11 , pulls up the paper S jammed in the middle of the paper transfer path, and resumes printing.  
       [0006] In the meantime, a paper guide structure in the main body  10  forming the transfer path of the paper S supplied from the cassette  12  is shown in FIGS. 1 through 2B. The guide structure includes a guide plate  11   a  provided inside the door  11  so that the paper S can pass while one surface of the paper S contacts the guide plate  11   a , a paper guide member  16  fixed to a main body frame  10   a , and a main feed roller  14 . The guide structure further includes an auxiliary feed roller  15 , and backup rollers  14   a  and  15   a  corresponding to the main feed roller  14  and the auxiliary feed roller  15 , respectively, which are rotatably installed at the main body frame  10   a  to transfer the paper S by catching it. A bracket  15   b  supports the auxiliary feed roller  15 . Thus, the paper S drawn from the cassette  12  guided by the paper guide member  16  passes the guide plate  11   a  and between the main feed roller  14 , the auxiliary feed roller  15 , and the backup rollers  14   a  and  15   a , to be transferred toward the transfer roller  13 .  
       [0007] However, when a paper jam occurs in the middle of the paper transfer path, the jammed paper S needs to be pulled up by opening the door  11 . If printing is in an initial state in which a leading end portion of the paper S is caught between the main feed roller  14  and the backup roller  14   a , the jammed paper S can be released by being pulled toward the cassette  12 . However, when the leading end portion of the paper S is caught between the auxiliary feed roller  15  and the backup roller  15   a , as shown in FIG. 2A, since the paper S cannot be released toward the cassette  12 , the paper jam requires more attention. In this case, the paper S can be pulled up in one of directions A of FIG. 2B and B or C of FIG. 2A. However, pulling in the direction A causes a high possibility of tearing the paper S. That is, since the side end portion of the paper S is caught by the main feed roller  14 , the auxiliary feed roller  15 , and the backup rollers  14   a  and  15   a , if the paper S is pulled up in the direction A (which is the axial direction of the respective rollers  14 ,  14   a ,  15 , and  15   a ), the paper S is highly likely to be torn, since the side end portion of the paper S is essentially clamped.  
       [0008] When the paper S is pulled up in the direction B, the possibility of tearing the paper S is low since the rollers  14 ,  14   a ,  15 , and  15   a  are rotated as the paper S is pulled up. However, since other units are typically installed above the paper S in the direction B, it is not easy to insert a hand to access the paper S. Thus, pulling the paper S in the direction C is the best direction to solve the paper jam problem. This is the direction where the door  11  is open so that the paper S can be pulled up by avoiding interference with other units and rotating the rollers  14 ,  14   a ,  15 , and  15   a . However, in the above structure, it is still possible to damage the paper S by pulling the paper S up in the direction C. That is, since the paper guide member  16  is installed above the auxiliary feed roller  15  in the frame  10   a , when the paper S is pulled up in the direction C, the paper S is released while it is folded by an end portion of the guide member  16  and pulled in contact with the end portion, with friction, as shown in FIG. 2A and portion D of FIG. 2B. Then, the paper S is scratched by the end portion of the guide member  16  and, in some cases, is highly likely to be torn. As a result, not only is the paper not usable, but also a remaining piece of the paper S needs to be pulled up.  
       SUMMARY OF THE INVENTION  
       [0009] Accordingly, it is an aspect of the present invention to provide a printer having a paper guide structure to prevent tearing of paper when a jammed paper is removed so that a stable paper jam solution is guaranteed.  
       [0010] Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.  
       [0011] The foregoing and/or other aspects may be achieved by providing a printer having a paper guide structure including a paper feeding portion to feed a paper; a transfer path; a first feed roller to move the fed paper along the transfer path; a second feed roller to receive the paper moved by the first feed roller and to transfer the paper along the transfer path; a guide member between the first and second feed rollers and the transfer path and to guide the paper along the transfer path; a main body; and a door installed at the main body to be opened and closed, wherein an empty space is formed toward the door at a rear of the second feed roller so that, when the door is opened and a leading end of the paper passing the second feed roller is pulled, the paper is discharged along an outer circumferential surface of the second feed roller.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0012] These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings of which:  
     [0013]FIG. 1 is a view illustrating a printer adopting a conventional paper guide structure;  
     [0014]FIGS. 2A and 2B are views illustrating the paper guide structure of FIG. 1;  
     [0015]FIG. 3 is a view illustrating a printer adopting a paper guide structure according to an embodiment of the present invention;  
     [0016]FIGS. 4A and 4B are views illustrating the paper guide structure of FIG. 3;  
     [0017]FIG. 5A is a view illustrating portions of the paper guide structure of FIG. 3; and  
     [0018]FIG. 5B is a magnified view illustrating portion A of FIG. 5A. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     [0019] Reference will now be made in detail to the present preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.  
     [0020] Referring to FIGS. 3 and 4A, a door  110  is installed to be opened or closed with respect to a main body  100  of a printer. A guide plate  111  is installed on an inner surface of the door  110  so that one surface of a paper S proceeds while contacting the guide plate  111 . Thus, when the door  110  is closed, the guide plate  111  is disposed at one side of a paper transfer path to support one surface of the paper S. Also, a first feed roller  140  and a first backup roller  141 , and a second feed roller  150  and a second backup roller  151  to transfer the paper S toward a transfer roller  130  by catching a side end portion of the paper S supplied from a cassette  120  which is a paper supply portion, are installed on a frame  101  at the main body  100  of the printer along the paper transfer path. That is, the paper S supplied from the cassette  120  enters the paper transfer path by being caught between the first feed roller  140  and the first backup roller  141 . Next, the paper S is continuously transferred by being caught between the second feed roller  150  and the second back up roller  151  and transferred toward the transfer roller  130 . Reference numeral  160  denotes a guide member provided on the frame  101  to prevent the paper S from deviating from the paper transfer path. The guide member  160  is provided between the first and second feed rollers  140  and  150 , between the first and second backup rollers  141  and  151 , and at the rear of the second backup roller  151 . The guide member  160  is not arranged at the rear of the second feed roller  150 . This arrangement forms an empty space around a portion facing the door  110  at the rear of the second feed roller  150 . For this purpose, a bracket  152  fixed to the frame  101  to support a rotation shaft of the second feed roller  150  has a “V” shape so that the bracket  152  does not protrude toward the portion facing the door  110  at the rear of the second feed roller  150 . Then, when the door  110  is opened to pull the jammed paper S, the paper S is smoothly pulled up along the outer circumferential surface of the second feed roller  150 . Instead of the guide member  160 , an auxiliary guide portion  112  to act as the guide member  160  is provided at the door  110  at the rear of the second feed roller  150  of the frame  101 , as shown in FIGS. 5A and 5B. Thus, when the door  110  is closed, the auxiliary guide portion  112  guides the paper S together with the guide member  160 . Since the auxiliary guide portion  112  is provided at the door  110 , it does not interfere with the paper S when the paper S is pulled up from the paper transfer path after the door  110  is opened.  
     [0021] When a print job is processed, the paper S supplied from the cassette  120  is transferred by the first and second feed rollers  140  and  150  along the transfer path to pass the transfer roller  130 . An image is transferred to one surface of the paper S and the paper S is discharged out of the printer.  
     [0022] When a paper jam occurs during the print process, the jammed paper S must be removed. If the paper S is jammed shortly after a leading end of the paper S is caught between the first feed roller  140  and the first backup roller  141 , the jammed paper S can be easily removed by being pulled up from the side of the cassette  120 . However, as shown in FIGS. 4A and 4B, when the leading end of the paper S has already passed between the second feed roller  150  and the second backup roller  151 , and when the trailing end of the paper S has already escaped from the cassette  120  and is caught between the first feed roller  140  and the first backup roller  141 , since the paper S cannot be moved back to the cassette  120 , the door  110  is opened and the paper S is pulled up from the side of the opened door  110 . Thus, in this state, when the paper S is pulled up by holding the leading end thereof from the side of the opened door  110 , as shown in FIGS. 4A and 4B, the paper S is removed as it contacts and slides along the outer circumferential surface of the second feed roller  150 . That is, the space around the door  110  at the rear of the second feed roller  150  is empty because no member, such as the guide member, is present to interfere with the paper S. Thus, the paper S escapes from the second feed roller  150  while it contacts only the outer circumferential surface of the second feed roller  150  and rotates the second feed roller  150 , so that the paper S can be smoothly removed.  
     [0023] Therefore, in the paper guide structure according to the embodiment of the present invention, when a paper jam where the paper S is caught between the first and second feed rollers  140  and  150  is processed, by only opening the door  110  and pulling up the leading end of the paper S, since the paper S is discharged without being scratched by other elements while it rotates the second feed roller  150 , the paper does not receive a tearing friction. As a result, the time to process the paper jam is reduced so that a prompt printer repair job is possible.  
     [0024] As described above, in the paper guide structure according to the embodiment of the present invention, the problem of torn paper during a paper jam process is solved so that a paper jam can be promptly and conveniently solved.  
     [0025] Although a preferred embodiment of the present invention has been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.