Abstract:
A versatile paper feeding device of an image forming apparatus includes a pick-up roller, a paper support tray under the pick-up roller to stack paper on, a paper support expansion tray to be able to freely slide toward or away from the paper support tray to support the trailing edge of the paper, a forward positioned paper alignment guide on the paper support tray to align a leading end portion of the paper, and a second paper alignment member formed on the paper support expansion tray to align a following end portion of the paper. When the versatile paper feeding device is used to print images on paper of various sizes, the paper can be properly positioned and straightly fed without skewing.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of Korean Application No. 2005-99176, filed Oct. 20, 2005, in the Korean Intellectual Property Office, the entire content of which is incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   Aspects of the present invention relate to a paper feeding device of an image forming apparatus. More particularly, aspects of the present invention relate to a versatile paper feeding device that can straightly feed papers without skewing when images are printed on various sizes of papers. 
   2. Description of the Related Art 
   An image forming apparatus such as a laser printer or a copier comprises a paper feeding device for feeding a print medium such as printing paper (hereinafter, paper) into the image forming apparatus body. The paper feeding device comprises a pick-up roller for picking up an individual sheet of the paper. One image forming apparatus may comprise a plurality of various kinds of feeding devices. Among the feeding devices, a versatile paper feeding device is necessitated to easily print on a small number of sheets of paper without having to open the feeding cassette, or to easily print on various sizes of paper such as an envelope or a small paper. 
     FIGS. 1 and 2  show the versatile paper feeding device. Referring to  FIGS. 1 and 2 , the versatile paper feeding device  1  comprises a pick-up roller  10 , a paper support member  22  disposed under the pick-up roller  10  to stack sheets of paper thereon, a paper support expansion member  21  formed to be capable of freely sliding toward the paper support member  22  to support the paper, and a paper alignment member  23  formed on the paper support member  22  to align the paper. The versatile paper feeding device  1  may be formed on a side cover frame  40  of the image forming apparatus. In the versatile paper feeding device  1 , as signals are transmitted to the image forming apparatus, a rotative shaft  12  is rotated by a driving device (not shown) and the pick-up roller  10  is simultaneously rotated so that the paper S is moved in direction A of  FIG. 2  and fed to the next step, i.e., a feeding roller (not shown) one at a time. As the versatile paper feeding device  1  prints on paper with a relatively greater size in a lengthwise direction such as letter, A4 or legal size, sufficient area for supporting the paper S cannot be obtained by using only the paper support member  22 . Therefore, the paper support expansion member  21  is extended so that sufficient area for supporting the paper S in a lengthwise direction is obtained and then the paper S is put thereon. Additionally, as the paper S is advanced in direction A for printing an image thereon, the paper alignment member  23  formed on the paper support member  22  is properly adjusted in an arrow direction B           C to constrain the paper S from moving in a widthwise direction.
   However, the conventional versatile paper feeding device  1  has the paper alignment member  23  formed only on the paper support member  22  of the leading end of the paper but has no separate paper alignment member on the paper support expansion member  21  of the following end of the paper. Therefore, as the versatile paper feeding device  1  prints on a paper with a relatively greater size in a lengthwise direction such as letter, A4 or legal size, the following end of the paper S is free to move in arrow direction D           E, while the paper S is fed through the pick-up roller  10  to the feeding roller (not shown), such that a skew occurs. When the paper S with a skew is fed to the feeding roller, the image is skewed as much as the paper S is skewed, and further, a jam may occur.
   SUMMARY OF THE INVENTION 
   Accordingly, aspects of the present invention are to solve at least the above and/or other problems and to provide advantages including the advantages described below. Therefore, an aspect of the present invention is to provide a versatile paper feeding device in which a following end of a paper is not skewed but straightly fed as an image forming apparatus prints on various sizes of paper so that printing quality can be enhanced. 
   An aspect of the invention provides a versatile paper feeding device, comprising a pick-up roller, a paper support member disposed under the pick-up roller to stack a paper thereon, a paper support expansion member formed to be capable of freely sliding toward the paper support member to support the paper, a first paper alignment member formed on the paper support member to align a leading end portion of the paper, and a second paper alignment member formed on the paper support expansion member to align a following end portion of the paper. 
   According to an aspect of the invention, the first paper alignment member may be slidingly formed in a traversing direction against a forwarding direction of the paper on the paper support member so as to align with a width size of the paper fed by the pick-up roller and thereby constrain transverse movement of the paper. 
   According to an aspect of the invention, the second paper alignment member may be formed to adjust to the width of the paper, where there are at least two different widths of paper to adjust to, to align the following end portion of the paper. 
   According to an aspect of the present invention, the second paper alignment member may comprise a supporting shaft detachably formed on the paper support expansion member, a pair of first protrusions each formed adjacent to an opposite end of the supporting shaft to adjust to the width of the paper, and a pair of second protrusions each formed adjacent to an opposite end of the supporting shaft and distanced from the pair of the first protrusions by a certain angle to adjust to a width of another paper. 
   According to an aspect of the present invention, the supporting shaft may comprise a stopper to stop the supporting shaft in a stable position when the supporting shaft is rotated by a certain angle. 
   According to an aspect of the present invention, the pair of the first protrusions and the pair of the second protrusions may be integrally formed with the supporting shaft. In an embodiment, the pair of the first protrusions and the pair of the second protrusions may be formed to be distanced from each other by about 90 degrees. The supporting shaft may be formed at a receiving part of the paper support expansion member so as to smoothly rotate with the first and the second protrusions. 
   According to another aspect of the present invention, the paper support expansion member may further comprise slits to receive the first and the second protrusions of the second paper alignment member. 
   According to another aspect of the present invention, the paper support member has a following end portion that is downwardly extended so that a certain space can be obtained within a boundary surface contacting the paper support expansion member. 
   According to an aspect of the invention, as the paper support expansion member is slid outward from the paper support member, the first and the second protrusions of the second paper alignment member collide with the following end portion of the paper support member so as to rotate in a forward or a backward direction and pass. 
   According to another aspect of the present invention, the second paper alignment member may comprise a supporting shaft detachably formed on the paper support expansion member, a pair of first protrusions formed adjacent to opposite ends of the supporting shaft to adjust to the width of a first size of paper, a pair of second protrusions formed to be distanced from the pair of the first protrusions by a certain angle to adjust to a width of a second size of paper, and a pair of third protrusions formed to be distanced from the second protrusions by a certain angle so as to adjust to a width of a third size of paper. According to an aspect of the invention, the paper support expansion member further comprises slits to receive the first, the second and the third protrusions of the second paper alignment member. 
   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. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
       FIG. 1  is a perspective view of a conventional versatile paper feeding device; 
       FIG. 2  is a view showing a status in which a paper is stacked on the versatile paper feeding device of  FIG. 1 ; 
       FIG. 3  is a perspective view of a versatile paper feeding device according to an embodiment of the present invention; 
       FIG. 4  is a plan view of a paper support member of  FIG. 3 ; 
       FIGS. 5A ,  5 B and  5 C are detailed construction views of a second paper alignment member of  FIG. 3 :  FIG. 5A  is a detailed view of a left side thereof,  FIG. 5B  is a front view of a right side thereof and  FIG. 5C  is a right side view thereof; 
       FIG. 6  is a detailed view of a part of a paper support expansion member having a receiving part for receiving the second paper alignment member; 
       FIG. 7  is a detailed view of a central portion of the second paper alignment member of  FIG. 3 ; 
       FIG. 8  is a detailed view of a part of a central portion of the paper support expansion member of  FIG. 3  according to another embodiment of the present invention; 
       FIGS. 9A and 9B  are views for explaining the operation of the second paper alignment member of  FIG. 3 ; and 
       FIG. 10  is a view of a status in which a paper is stacked on the versatile paper feeding device of  FIG. 3 . 
   

   DETAILED DESCRIPTION OF THE EMBODIMENTS 
   Reference will now be made in detail to the present 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. 
     FIG. 3  is a perspective view of a versatile paper feeding device according to an embodiment of the present invention, and  FIG. 4  is a plan view of a paper support expansion member of the versatile paper feeding device. Although the term paper is used throughout the description, it is not meant to limit the invention thereto, that is, the term paper is meant to encompass print medium such as paper, card stock, transparencies, envelopes, etc. 
   Referring to  FIGS. 3 and 4 , a versatile paper feeding device  100  according to an embodiment of the present invention, comprises a first paper alignment member  123  formed on a paper support member  122  to align a leading end of a paper S and prevent any free movement of the paper S in a widthwise direction while the paper S is fed in a forward direction A (refer to  FIG. 10 ). In the versatile paper feeding device  100 , a second paper alignment member  130  is further formed on the paper support expansion member  121  to prevent the free movement of a following end of the paper S in a width wise direction D           E in  FIG. 10 .
   The versatile paper feeding device  100  comprises a pick-up roller  110  engaged with a rotative shaft  112 , a paper support member  122  to stack the paper S thereon, a paper support expansion member  121 , and paper alignment members  123  and  130  to align the paper S. 
   The pick-up roller  110  is engaged with the rotative shaft  112  to be rotated together by a driving source (not shown). 
   The paper support member  122  is disposed under the pick-up roller  110  to stack the paper S thereon so that the pick-up roller  110  can feed an individual sheet of the paper S into an image forming apparatus. The paper support member  122  may be generally formed on a side cover frame  140  of the image forming apparatus. 
   The paper support expansion member  121  is formed on the side cover frame  140  so as to freely slide toward the paper support member  122  and to support a large size of a paper. The paper support expansion member  122  has a following end portion  122   e  that is downwardly extended so that a certain space H (refer to  FIG. 9 ) can be obtained within a boundary surface contacting the paper support expansion member  121 . In the specification of the present invention, a ‘leading end portion’ refers to a front portion of a paper, first in a feeding direction in the versatile paper feeding device  100 , and a ‘following end portion’ refers to a portion near the opposite end of the paper in the paper feeding direction. 
   The paper support member  122  and the paper support expansion member  121  of the versatile paper feeding device according to an embodiment of the present invention include the paper alignment members  123  and  130 , respectively. 
   The first paper alignment member  123  is formed on the paper support member  122  to align the leading end portion of the paper S. The first paper alignment member  123  is slidingly formed in a traverse direction to a paper feeding direction of the paper S on the paper support member  122  so as to align with the width size of the paper S fed by the pick-up roller  110  and constrain the transverse movement thereof. 
   The second paper alignment member  130 , which is not included in the conventional versatile paper feeding device, is detachably formed on the paper support expansion member  121 . The second paper alignment member  130  is formed near the following end portion of the paper S to align the following end portion of the paper S. The second paper alignment member  130  is formed to adjust to the width of the paper, where the second paper alignment member  130  can adjust to at least two different paper widths, and align the following end portion of the paper. 
     FIGS. 5 through 8  are the detailed construction views of the second paper alignment member.  FIG. 5A  is a detailed view of a left side of the second paper alignment member  130 ,  FIG. 5B  is a front view of a right side thereof, and  FIG. 5C  is a right side view thereof.  FIG. 6  is a detailed view of a part of a paper support expansion member  121  having a receiving part  121   a  for receiving the second paper alignment member  130 .  FIG. 7  is a detailed view of a central portion of the second paper alignment member  130 , and  FIG. 8  is a detailed view of a part of a central portion of another embodiment of the paper support expansion member  121 . 
   Referring to  FIG. 4 , the second paper alignment member  130  comprises a supporting shaft  133  and two pairs of protrusions  131   a ,  131   b  and  132   a ,  132   b , respectively. 
   The supporting shaft  133  is cylindrical and has supporting protrusions  133   a ,  133   b  formed on each end portion. The supporting shaft  133  is formed at the receiving part  121   a  of the paper support expansion member  121 . The supporting shaft  133  may be momentarily elastically bent by force so that the supporting protrusions  133   a ,  133   b  are inserted into or separated from a supporting groove  121   c  of the receiving part  121   a . Therefore, the supporting shaft  133  can be detached from and attached to the paper support expansion member  121  by snapping out of and in place, respectively. As attached to the paper support expansion member  121 , the supporting shaft  133  can be rotated. In the central portion of the supporting shaft  133 , a stopper  133   d , which is non-circular, may be formed. The receiving part  121   a  in the central portion of the paper support expansion member  121  is formed to be narrow  121   b  so that the stopper  133   d  can be inserted therein. The supporting shaft  133  can thus be located in a regular position by the stopper  133   d , and therefore, the protrusions  131   a ,  131   b ,  132   a , and  132   b  of the supporting shaft  133  can also be located in corresponding regular positions. 
   The paper support expansion member  121  is made of elastically deformable material such as plastic or metal so that rounded edges of the stopper  133   d  can slightly push the inner wall of the paper support expansion member  121  as the stopper  133   d  of the central portion of the paper support expansion member  121  is rotated. Accordingly, the stopper  133   d  can stop the second paper alignment member  130  in a stable position after the second paper alignment member  130  is rotated by a certain angle. As shown in  FIG. 8 , the paper support expansion member  121  may further comprise, in a central portion, buffering slits  124   a ,  124   b  so that the stopper  133   d  can more smoothly operate. 
   Each protrusion  131   a ,  131   b  of the first pair is formed adjacent to each respective end of the supporting shaft  133  to adjust to the width of the paper S. The protrusions  132   a ,  132   b  of the second pair may each be formed at a certain distance and angle from each respective protrusion  131   a ,  131   b  of the first pair, to adjust to the width of another size of paper. The first pair of protrusions  131   a ,  131   b  and the second pair of protrusions  132   a ,  132   b  may be integrally formed with the supporting shaft  133 . According to an embodiment, the first pair of protrusions and the second pair of protrusions may be formed from each other by an angle of about 90 degrees. 
   The protrusions  131   a ,  131   b , are formed to adjust to the width of a relatively large size of paper such as A4 and similarly, the protrusions  132   a ,  132   b  may be formed to adjust to the width of letter size. However, this should not be considered as limiting. At least one of the pair of protrusions may be formed to adjust to the width of a smaller size of paper as necessary. Although not shown, according to another embodiment, a third pair of protrusions, in addition to the two pairs of protrusions  131   a ,  131   b , and  132   a ,  132   b , may be further formed to adjust to the width of a third size of paper. For example, the pair of third protrusions may be formed on the supporting shaft  133  at an appropriate distance and at an appropriate angle from the two pairs of protrusions  131   a ,  131   b , and  132   a ,  132   b , for example, by approximately 90 degrees and 180 degrees from the second and first pairs, respectively, so as to adjust to the width of another size of paper. The pairs of protrusions can be straight parallel protrusions according to an embodiment of the invention, however, the protrusions need not be. That is, the protrusions may be set at an angle to the supporting shaft  133  or the individual protrusion may have a bend to strengthen the protrusion, facilitate paper alignment and/or facilitate the rotation of the supporting shaft  133 . 
   The paper support expansion member  121  includes slits  126   a ,  126   b ,  127   a ,  127   b  corresponding to the protrusions so as to receive the protrusions  131   a ,  131   b ,  132   a ,  132   b  of the second paper alignment member  130 . If a plurality of pairs of protrusions are formed, the paper support expansion member  121  needs to include a corresponding plurality of pairs of slits to receive the plurality of pairs of protrusions. 
   The operations of the versatile paper feeding device according to an embodiment of the present invention will be explained hereinafter with reference to accompanying drawings. 
     FIG. 9  is a view for explaining the operation of the second paper alignment member  130  and  FIG. 10  is a view for explaining the operation of the versatile paper feeding device  100  according to an embodiment of the present invention. Referring to  FIGS. 9 and 10 , in the versatile paper feeding device  100 , the paper support expansion member  121  is slid outward of the paper support member  122 . At this time, one of the pairs of protrusions  131   a ,  131   b  and  132   a ,  132   b  of the second paper alignment member  130  collide with the following end portion  122   e  of the paper support member  122  and rotate in a forward or backward direction so as to pass the following end portion  122   e  of the paper support member  122 . To this end, the following end portion  122   e  of the paper support member  122  is downwardly extended so as to obtain a certain space H within a boundary surface contacting the paper support expansion member  121 . 
   When image printing is not desired, the versatile paper feeding device  100  is pushed into the image forming apparatus body, the paper support expansion member  121  is slid in a paper forwarding direction, i.e., the direction A, so that one of the pairs of protrusions  131   a ,  131   b  and  132   a ,  132   b  of the second paper alignment member  130  collide with the following end portion  122   e  of the paper support member  122 , rotate and smoothly pass. For example, the second pair of protrusions  132   a ,  132   b  retreat into the slits  127   a ,  127   b  and the first pair of protrusions  131   a ,  131   b  rotate up in the space H as shown in  FIG. 9B . Similarly, when the versatile paper feeding device  100  is drawn from the image forming apparatus body to print an image, the paper support expansion member  121  is pulled in an opposite direction to the paper forwarding direction, i.e., the direction −A, so that one of the pairs of protrusions  131   a ,  131   b  and  132   a ,  132   b  of the second paper alignment member  130  collide with the following end portion  122   e  of the paper support member  122 , rotate in the opposite direction and smoothly pass. Particularly, as shown in  FIG. 9A , the first pair of protrusions  131   a ,  131   b  retreat into the slits  126   a ,  126   b  and the second pair of protrusions  132   a ,  132   b  pop up. 
   When the paper support expansion member  121  is positioned as in  FIG. 9A , the versatile paper feeding device  100  can align the following end portion of the paper S by the pairs of protrusions  131   a ,  131   b  or  132   a ,  132   b  of the second paper alignment member  130  when an A4 or letter size of paper is fed. In other words, if A4 size of paper is placed on the paper support member  122  and the paper support expansion member  121 , the second paper alignment member  130  is rotated by a certain angle so that the first pair of protrusions  131   a ,  131   b  pop up adjusted to the width of the A4 size of paper so as to align the following end portion of the paper. On the contrary, when letter size of paper is placed on the paper support member  122  and the paper support expansion member  121 , the second paper alignment member  130  is rotated so that the second pair of protrusions  132   a ,  132   b  of the supporting shaft  133  pop up adjusted to the width of the letter size of paper so as to align the following end portion of the letter size paper. 
   As the certain size of paper is stacked and print signals are received from a central control part (not shown) to print an image, the rotative shaft  112  is rotated and the pick-up roller  110 , coaxially formed with the rotative shaft  112 , is also rotated. The paper S is moved in direction A of  FIG. 10  and fed to the next step, i.e., the feeding roller (not shown). In other words, while the paper S is picked up by the pick-up roller  110  and moved in direction A, the protrusions  131   a ,  131   b ,  132   a ,  132   b  of the second paper alignment member  130  align the following end portion of the paper so that the paper S is straightly fed without a skew to the next step, i.e., the feeding roller. For the straightly aligned paper S, skew can be eliminated when the following end portion of the paper S leaves from the second paper alignment member  130  at the moment when the leading end portion of the paper S is fed to the feeding roller. 
   The versatile paper feeding device  100  according to an embodiment of the present invention, further includes the second paper alignment member besides the first paper alignment member so that the paper is straightly fed to the feeding roller and not skewed when an image is printed. Therefore, the side skew can be prevented, an even side margin can be achieved and the quality of paper feeding can be enhanced. 
   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 this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.