Abstract:
A feeding roller shaft supporter for an ink-jet printer having a feeding roller shaft, including a main chassis which forms a frame of an ink-jet printer; a first supporting unit in the main chassis supporting opposite ends of the feeding roller shaft; a driving member provided at a first end of the feeding roller shaft; an axial position correction unit mounted on the feeding roller shaft close to the driving member, correcting an axial position of the feeding roller shaft; and a second supporting unit supporting the feeding roller shaft, wherein the second supporting unit is provided on a second end of the feeding roller shaft, preventing the shaking of the feeding roller shaft caused by thrust when the feeding roller shaft rotates.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
         [0001]    This application claims the benefit of Korean Application Nos. 2002-64350, filed Oct. 21, 2002 and 2002-80509, filed Dec. 16, 2002, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to an ink-jet printer, and, in particular, to a feeding roller shaft supporter for an ink-jet printer, which rotatably supports a feeding roller shaft for feeding printing paper in an ink-jet printer.  
           [0004]    2. Description of the Related Art  
           [0005]    A feeding roller shaft for an ink-jet printer feeds printing paper loaded in a paper-feeding tray into an image formation section disposed within the printer. Such a feeding roller shaft rotates by receiving power from a separate power source when the printer is driven. In that event, it is often impossible to obtain a desired printing result because distorted printing is generated if shaking is rendered to the feeding roller shaft. Therefore, when a feeding roller shaft supporter is designed and constructed, it is required to take the above points into consideration. Furthermore, as resolution of ink-jet printers increases, even fine shaking may have a harmful influence on the printing result. Therefore, it is a requirement to carefully deal with the design of the feeding roller shaft.  
           [0006]    [0006]FIGS. 1 and 2 schematically illustrate a conventional feeding roller shaft supporter, in which reference numeral  10  denotes a main chassis,  20  denotes a feeding roller shaft, and  30  denotes a maintenance station.  
           [0007]    As shown in FIGS. 1 and 2, the main chassis  10  is provided with first to third stationary pieces  11 ,  12 , and  13 , in which the first and second stationary pieces rotatably support opposite ends of the feeding roller shaft  20  by way of a first supporting unit  21  comprising first and second bushings  21   a  and  21   b , respectively. In addition, the maintenance section  30  is installed between the second and third stationary pieces  12  and  13 .  
           [0008]    One end of the feeding roller shaft  20  is provided with a driving gear  22 , and an axial position correction unit  23  is provided adjacent to the driving gear  22  to correct the axial position of the feeding roller shaft  20  when it rotates. The axial position correction unit  23  comprises a spring anchoring ring  23   a  mounted at a position spaced from the position where the driving gear  22  is connected to the feeding roller shaft  20 ; a spring washer  23   b  connected to be in contact with the first bushing  21   a ; and a spring  23   c  installed between the anchoring ring  23   a  and the spring washer  23   b . The anchoring ring  23   a  is connected such that the spring  23   c  is compressively contracted by the anchoring ring  23   a.    
           [0009]    The feeding roller shaft  20 , which is rotatably supported by the feeding roller shaft supporter, as mentioned above, transfers paper into an image formation section disposed within the ink-jet printer while the feeding roller shaft  20  is being rotated by a driving force, supplied via the driving gear  22 , when the ink-jet printer is driven.  
           [0010]    However, the feeding roller shaft supporter of the conventional ink-jet printer has a problem in that shaking is rendered to the feeding roller shaft  20  by the thrust generated when the feeing roller shaft  20  rotates, because the feeding roller shaft  20  is simply supported by the first and second stationary pieces  11  and  12  at its opposite ends. In addition, the feeding roller supporter has a problem in that the precision of the gear additionally provides a cause of shaking of the feeding roller shaft  20  because the driving gear  22  is closely contacted with the first supporting unit  21 , being positioned adjacent to the first supporting unit  21 . If the feeding roller shaft is axially shaken as such, distorted printing is caused, and high-density printing is rendered difficult as a result. Therefore, the prevention of the axial shaking of the feeding roller shaft caused by thrust when the feeding roller shaft rotates is required.  
         SUMMARY OF THE INVENTION  
         [0011]    Accordingly, the present invention has been made to solve the above-mentioned and/or other problems occurring in the related art, and an aspect of the present invention is to provide a feeding roller shaft supporter for an ink-jet printer, which allows a user to obtain a printing result with a desired high resolution by preventing the axial shaking of the feeding roller shaft when the shaft rotates, so that the distortion occurring during printing on paper, which is caused by the shaking of the feeding roller shaft, can be avoided.  
           [0012]    Additional aspects and/or 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.  
           [0013]    In order to achieve the above and/or other aspects, according to the present invention, there is provided a feeding roller shaft supporter for an ink-jet printer having a feeding roller shaft, which comprises: a main chassis which forms a frame of an ink-jet printer; a first supporting unit in the main chassis supporting opposite ends of the feeding roller shaft; a driving member provided at a first end of the feeding roller shaft; an axial position correction unit mounted on the feeding roller shaft close to the driving member, correcting an axial position of the feeding roller shaft; and a second supporting unit supporting the feeding roller shaft, wherein the second supporting unit is provided on a second end of the feeding roller shaft, preventing the shaking of the feeding roller shaft caused by thrust when the feeding roller shaft rotates.  
           [0014]    According to an embodiment of the present invention, the first supporting unit may comprise first and second bushings, the first and second bushings respectively located at opposite ends of the feeding roller shaft.  
           [0015]    In addition, a predetermined interval may be formed between the driving member and the first supporting unit at the first end of the feeding roller shaft, so that the driving member does not come into contact with the first supporting unit.  
           [0016]    And, the second supporting unit may comprise an anchoring ring and a washer centered about the feeding roller shaft, in which the second supporting unit may be provided to be in face-contact with a surface of the first supporting unit facing the first end of the feeding roller shaft.  
           [0017]    According to another embodiment of the present invention, the second supporting unit may comprise a cap provided distally from the second end of the feeding roller shaft, and the cap is in point-contact with a fixed body inside the main chassis.  
           [0018]    According to yet another embodiment of the present invention, the second supporting unit may comprise: a cap provided at the second end of the feeding roller shaft; and a cap supporting member, the cap being in point-contact with the cap supporting member, wherein the cap supporting member is assembled to the main chassis or a fixed body inside the main chassis in a screw connection manner so that an extension of the cap supporting member is adjustable. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]    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:  
         [0020]    [0020]FIG. 1 is a perspective view which schematically illustrates a conventional feeding roller shaft supporter for an inkjet printer;  
         [0021]    [0021]FIG. 2 is a cross-sectional view of the feeding roller shaft supporter shown in FIG. 1;  
         [0022]    [0022]FIG. 3 is an exploded perspective view which illustrates a main part of the feeding roller shaft supporter for an ink-jet printer according to an embodiment of the present invention;  
         [0023]    [0023]FIG. 4 is a cross-sectional view which illustrates the assembled state of the feeding roller shaft supporter shown in FIG. 3;  
         [0024]    [0024]FIG. 5 is a perspective view which illustrates the state in which the feeding roll shaft is installed in a printer by way of the feeding roller shaft supporter according to the embodiment of the present invention shown in FIG. 3;  
         [0025]    [0025]FIG. 6 is an exploded perspective view which illustrates a main part of the feeding roller shaft supporter for an ink-jet printer according to another embodiment of the present invention;  
         [0026]    [0026]FIG. 7 is a cross-sectional view which illustrates the assembled state of the feeding roller shaft supporter shown in FIG. 6;  
         [0027]    [0027]FIG. 8 is an exploded perspective view which illustrates a main part of the feeding roller shaft supporter for an ink-jet printer according to yet another embodiment of the present invention;  
         [0028]    [0028]FIG. 9 is a cross-sectional view which illustrates the assembled state of the feeding roller shaft supporter shown in FIG. 8; and  
         [0029]    [0029]FIG. 10 is a perspective view which illustrates the state in which the feeding roller shaft is installed in a printer by way of the feeding roller shaft supporter according to still another embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0030]    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 the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.  
         [0031]    Referring to FIGS.  3  to  5 , reference numeral  10  denotes a main chassis,  20  denotes a feeding roller shaft,  21  denotes a first supporting unit,  21   a  and  21   b  denote first and second bushings, respectively,  30  denotes a maintenance station, and  40  denotes a second supporting unit.  
         [0032]    FIGS.  3  to  5  show an embodiment of the present invention, in which the main chassis  10  is provided with first to third stationary pieces  11 ,  12  and  13  which are spaced from each other.  
         [0033]    The feeding roller shaft  20  is supported by the first and second stationary pieces  11  and  12  in the opposite ends thereof by way of the first supporting unit  21 . Further, a driving gear  22  is engaged with an end of the feeding roller shaft  20 , in which the driving gear  22  is provided with power from a power source, which is not shown. The driving gear engaged end is provided with an axial position correction unit  23  to correct the axial position of the feeding roller shaft  20  when the feeding roller shaft  20  rotates.  
         [0034]    The first supporting unit  21  comprises a first bushing  21   a  supporting the driving gear engaged end of the feeding roller shaft  20 , and a second bushing  21   b  supporting the other end of the feeding roller shaft  20 .  
         [0035]    The axial position correction unit  23  comprises a spring anchoring ring  23   a  mounted at a location spaced from the position where the driving gear  22  is engaged with the feeding roller shaft  20 ; a spring washer  23   b  connected to be in contact with the first bushing  21   a ; and a spring  23   c  installed between the anchoring ring  23   a  and the spring washer  23   b . The anchoring ring  23   a  is connected such that the spring  23   c  is compressively contracted by the anchoring ring  23   a.    
         [0036]    The maintenance station  30  is installed between the second and third stationary pieces  12  and  13 .  
         [0037]    The second supporting unit  40  supports the feeding roller shaft  30  on an end of the feeding roller shaft  20  opposite of the axial position correction unit  23 , in order to prevent the feeding roller shaft from being shaken by thrust when the feeding roller shaft  20  rotates. The second supporting unit  40  comprises an anchoring ring  41  and a washer  42 , and is fitted on the feeding roller shaft  20 . In that event, the anchoring ring  41  and the washer  42  are mounted to be in face-contact with the second bushing  21   b  on the inner surface of the second bushing  21   b , thereby increasing the axial supporting points for the feeding roller shaft  20 , so that the shaking of the feeding roller shaft can be prevented when the feeding roller shaft rotates.  
         [0038]    Meanwhile, the feeding roller shaft supporter comprises a gap g with a predetermined size, which is formed between the driving gear  22  and the first bushing  21   a , as shown in FIG. 4. Therefore, the driving gear  22  and the first bushing  21   a  do not come into contact with each other, as a result of which it is possible to avoid one cause of the axial shaking of the feeding roller shaft  20  caused by the contact between the driving gear  22  and the first bushing  21   a  due to a deviation in the precision of the driving gear  22 .  
         [0039]    FIGS.  6  to  10  illustrate two more embodiments of the present invention, in which reference numeral  10  denotes a main chassis,  20  denotes a feeding roller shaft,  21  denotes a first supporting unit,  21   a  and  21   b  denote first and second bushings, respectively,  30  denotes a maintenance station, and  50  denotes a second supporting unit.  
         [0040]    The main chassis  10  is provided with first to third stationary pieces  11 ,  12  and  13 , which are spaced from each other.  
         [0041]    The feeding roller shaft  20  is supported by the first and second stationary pieces  11  and  12  on the opposite ends thereof by way of the first supporting unit  21 . Further, a driving gear  22  is engaged with an end of the feeding roller shaft  20 , in which the driving gear  22  receives power from a power source, which is not shown. The driving gear engaged end is provided with an axial position correction unit  23  to correct the axial position of the feeding roller shaft  20  when the feeding roller shaft  20  rotates.  
         [0042]    The first supporting unit  21  comprises a first bushing  21   a  for supporting the driving gear engaged end of the feeding roller shaft  20 ; and a second bushing  21   b  for supporting the other end of the feeding roller shaft  20 .  
         [0043]    The axial position correction unit  23  comprises a spring anchoring ring  23   a  mounted at a location spaced from the position where the driving gear  22  is engaged with the feeding roller shaft  20 ; a spring washer  23   b  connected to be in contact with the first bushing  21   a ; and a spring  23   c  installed between the anchoring ring  23   a  and the spring washer  23   b . The anchoring ring  23   a  is connected such that the spring  23   c  is compressively contracted by the anchoring ring  23   a.    
         [0044]    The maintenance station  30  is installed between the second and third stationary pieces  12  and  13 .  
         [0045]    As shown in FIGS. 6 through 8, the second supporting unit  50 , according to another embodiment of the present invention, comprises a cap  51  inserted into an end of the feeding roller shaft  20 , and provided with a rounded external surface; and a cap supporting member  52  connected to a side wall of the maintenance station  30  in a screw connection manner. The cap  51  is arranged in such a way that its rounded external surface is in point-contact with the cap supporting member  52 .  
         [0046]    Because the second supporting unit  50 , as described above, increases the axial supporting part for the feeding roller shaft  20 , the shaking of the feeding roller shaft can be prevented when the feeding roller shaft  20  rotates.  
         [0047]    Meanwhile, the supporting unit  50  according to yet another embodiment of the present invention can be constructed with only the cap  51 , as shown in FIGS. 9 and 10. In that event, the rounded external surface of the cap  51  is directly in point-contact with a sidewall of the maintenance station  30 . As a result, the supporting points for the feeding roller in this embodiment also increase, and thus it is possible to obtain the functional effects as in the previous embodiment.  
         [0048]    However, by constructing the supporting unit  50  from the cap  51  and the cap supporting member  52  as in the previous embodiment, additional effects can be obtained along with the prevention of shaking of the feeding roller shaft.  
         [0049]    For example, if the cap supporting member  52  is added, the gap g formed between the driving gear  22  and the first bushing  21   a  (see FIG. 4) can be more efficiently maintained than in the originally presented embodiment, so that the driving gear  22  and the first bushing  21   a  do not come into direct contact with each other. In particular, it is beneficial to properly maintain the gap g because the shaking of the feeding roller may increase due to the flexure and deviation in flatness of the driving gear  22  and the first bushing  21   a  if these components come into direct contact. If the cap supporting member  52  is provided, and assembled to the wall of the maintenance station  30  to support the cap  51  in the screw connection manner, it is possible to maintain and/or adjust the gap g by adjusting the extension amount of the cap supporting member  52 .  
         [0050]    The feeding roller shaft  20 , rotatably supported on the main chassis  10  by the feeding roller shaft supporter constructed as described above, is rotationally driven by the power transmitted through the driving gear  22  to feed paper into the image formation section within the printer. In that event, the feeding roller shaft  20  is supported and rotated by the second supporting unit  40  at a definite point; and it is possible to prevent the axial shaking of the feeding roller shaft. Therefore, the distortion of printing on paper caused by the axial shaking of the feeding roller shaft can be avoided, and thus it is possible to obtain a printing result with the desired resolution from a high-density printer.  
         [0051]    In the illustrated embodiments, the cap  51  has a rounded external surface and the cap supporting member  52 , which is in point-contact with the cap  51 , is formed flat. However, the present invention is not limited to such a construction, and the cap  51  and cap supporting member  52  may take any other form being in point-contact with each other. For example, the external surface of the cap  51  may take a cylindrical shape with a flat end face, while the cap supporting member  52  may take a rounded shape.  
         [0052]    In addition, the frictional force generated between the cap  51  and the cap supporting member  52  can be minimized in the embodiment described above because the cap  51  and the cap supporting member  52  are arranged to be in point-contact, whereby it is possible to avoid the excessive loss of rotational force of the feeding roller shaft  20  due to the frictional force.  
         [0053]    As described above, according to these embodiments of the present invention, additional support for supporting an end of the feeding roller shaft is provided, so that the supporting force can be axially applied to the feeding roller shaft. Consequently, the distortion of printing on paper caused by the axial shaking of the feeding roller shaft can be avoided, and thus it is possible to obtain a printing result with the desired resolution from a high-density printer.  
         [0054]    Furthermore, because the driving gear is spaced with a predetermined interval from the first bushing for supporting the feeding roller shaft, it is possible to prevent the feeding roller shaft from being shaken due to a deviation in the precision of the driving gear, whereby the reliability of the resultant product can be enhanced.  
         [0055]    Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.