Patent Abstract:
An image reading apparatus with a structure capable of reliably discharging a document, and a multi-functional machine having the same are disclosed. The image reading apparatus includes a document feed path having a document outlet, a reading unit which reads an image of a document fed through the document feed path, and a guide member which is disposed at the document outlet downstream of the reading unit to form a curl on the trailing end portion of the document. The curl formed on the document may make it possible for a subsequent document being discharged to push the curled document out of the document outlet.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation Application of prior of application Ser. No. 12/343,860, filed on Dec. 24, 2008 in the United States Patent and Trademark Office, which claims the benefit of Korean Patent Application No. 2008-0027810, filed on Mar. 26, 2008 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an image reading apparatus, and a multi-functional machine having the same, and, more particularly, to an image reading apparatus with improved reliability of a document discharging operation, and a multi-functional machine having the same. 
     2. Description of the Related Art 
     An image reading apparatus reads an image recorded on a document through an image sensor. Devices containing image reading apparatuses include copiers, scanners, fax machines, multi-functional devices, and similar image reading machines. In order to read information from the document, the image reading machine must either move a reading unit relative to a stationary document or the document relative to a stationary reading unit. An image reading machine in which the document moves is known as a “sheet feed type”. 
     The sheet feed type image reading machine includes an automatic document feeder which feeds the document through the machine. The document fed by the automatic document feeder is scanned by the reading unit and, once scanned, discharged to the outside. If the document is not fully discharged from the unit, the stalled document may cause the subsequently scanned and discharged document(s) to jam or shuffle out of sequence. 
     Many image reading machines discharge a document using a dedicated discharge roller disposed at the downstream side of the reading unit after reading an image. While the dedicated rollers may ensure the discharging of the documents, the space required for the installation of the dedicated rollers places a limit on reduction of the size of the image reading machine. 
     Some image reading machines discharge documents without using a discharge roller. If a document outlet of the image reading machine is positioned a sufficient distance below the reading unit, the document&#39;s own weight propels it downward to the document outlet. This configuration however unfortunately also places a limit on the minimum size of the image reading machine, particularly in the vertical dimension. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various aspects and advantages of the embodiments 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  illustrates a configuration of a multi-functional machine including an image reading machine according to an embodiment of the invention; 
         FIG. 2  illustrates a perspective view of the image reading machine of  FIG. 1  according to an embodiment of the invention; 
         FIG. 3  illustrates an enlarged view of a portion of  FIG. 1 ; 
         FIG. 4  is a diagram illustrating a document discharging operation according to an embodiment of the invention; 
         FIG. 5  illustrates a perspective view of a partial configuration of an image reading machine according to another embodiment of the invention; and 
         FIG. 6  illustrates a perspective view of a partial configuration of an image reading machine according to another embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. While the embodiments are described with detailed construction and elements to assist in a comprehensive understanding of the various applications and advantages of the embodiments, it should be apparent however that the embodiments can be carried out without those specifically detailed particulars. Also, well-known functions or constructions will not be described in detail so as to avoid obscuring the description with unnecessary detail. It should be also noted that in the drawings, the dimensions of the features are not intended to be to true scale, and may be exaggerated for the sake of allowing greater understanding. 
     As shown in  FIGS. 1 and 2 , an example multi-functional machine  1  may include a main body  10 , an image reading apparatus  100  which reads image information from the document, and a printing apparatus  200  which prints an image on a printing medium.  FIG. 2  omits an upper cover  20  and a white roller  126  which are present in  FIG. 1 . Although an image reading machine is described in this embodiment as a part of a multi-functional machine including a facsimile function, the following description may be applied to other embodiments of a multi-functional machine having no facsimile function, a copying machine, a scanner and various other machines which read an image recorded on the document through a reading unit. 
     The main body  10  defines an external appearance of the multi-functional machine  1 . Various parts forming the image reading apparatus  100  and the printing apparatus  200  may be supported in and/or on the main body  10 . 
     The multi-functional machine  1  may include a printing apparatus  200 , which prints an image on a printing medium according to the image read by the image reading apparatus  100  or according to a fax image received from an external communication network. The printing apparatus  200  may include a paper loading tray  210 , a paper pickup roller  220 , a paper feed roller  230 , a printing unit  240  and a paper discharge roller  250 . In a printing operation, a printing medium such as paper S may be loaded on the paper loading tray  210 , picked up sheet by sheet by the paper pickup roller  220 , and transferred toward the paper feed roller  230 . The paper feed roller  230  may align the paper and supply the aligned paper to the printing unit  240 . The printing unit  240  may include, in this so called ink-jet printing example, a print head  241  having a nozzle through which droplets of ink may be sprayed. Other types of printing unit, for example, and electro-photographic type printing unit may alternatively be used. In the ink-jet type example, the printing unit  240  may print an image on the paper while reciprocating in a width direction of the transferred paper. The paper discharge roller  250  may discharge the paper to the outside of the main body  10  through a paper discharge port  12 . 
     An upper cover  20  may be installed on the main body  10 . The upper cover  20  may be rotatably coupled to the main body  10  through a hinge shaft  21  disposed at one end portion of the upper cover  20 , or it may be coupled by some other means. A number of control keys  22  may be disposed on a surface of the upper cover  20  to allow a user to control the multi-functional machine  1 . 
     A document feed path  123  of the image reading apparatus  100  may be defined between an upper surface  11  of the main body  10  and the upper cover  20 . A user may separate the upper cover  20  from the main body  10  to remove a document jammed in the document feed path  123  or to clean various parts installed on the inside of the main body  10 . 
     The image reading apparatus  100  may include a reading unit  110  which reads image information from the document, and an automatic document feeder  120 , which may automatically feeds the document to enable a continuous reading operation. 
     The reading unit  110  may be disposed on the document feed path  123 . As shown in  FIG. 3 , the reading unit  110  may include a reading sensor  111 , which reads image information from the document fed from the automatic document feeder  120 , and a glass portion  112 , which is disposed on the reading sensor  111  to be in contact with the document. The glass portion  112  may be made of any transparent material that allows the information on the document to pass to the reading sensor  111 . The reading sensor  111  may employ a contact image sensor (CIS), a charge coupled device (CCD), or other imaging sensor. 
     The automatic document feeder  120  may include a document inlet  121 , which receives the document, a document outlet  122  which discharges the document, a document feed path  123  provided between the document inlet  121  and the document outlet  122 , and rollers which may be disposed on the document feed path  123  to feed the document. The document inlet  121  may be disposed on one side of the document feed path  123 . The document outlet  122  may be disposed on an opposing side of the document feed path  123 . A document loading tray  124 , on which a document D may be loaded, may be disposed adjacent to the document inlet  121 . The document feed path  123  may be inclined toward the document outlet  122  from the document inlet  121 . 
     The rollers adapted to feed the document may include a document feed roller  125 , which picks up a document D loaded on the document loading tray  124  sheet by sheet to supply the document D to the document feed path  123 , and a white roller  126 , which feeds the document through the document feed path  123 . The white roller  126  may face the reading unit  110 , and maintain the document in contact with the glass portion  112 . The white roller  126  and the reading unit  110  may be disposed in proximity to the document outlet  122 . According to an embodiment, the white roller  126  may be disposed above the reading unit  112 . After the rear end portion of the document passes the location where the white roller  126  is nearest to the glass portion  112 , the document no longer receives a discharging force from the white roller  126 . When the document being discharged encounters a sufficient friction with the surface B (see  FIG. 4 ), onto which the document is being discharged or with other documents already piled on the surface B, the document may remain in the document outlet  122  without being fully discharged. 
       FIGS. 1 to 3  depict an embodiment, in which the image reading apparatus  100  may include at least one guide member  130 , which may generate a widthwise curl on the trailing end of the document as the document is being discharged through the document outlet  122 . When the document fails to be fully discharged, the curl of the document may allow a next discharged document to push the stalled document through the document outlet  122 . 
     In one embodiment of the invention, the at least one guide member  130  may include a first guide rib  131  and a second guide rib  132  which are disposed at the document outlet  122 . The first guide rib  131  and the second guide rib  132  may protrude toward the document feed path  123  and lift the document by interfering with the document as it is discharged through the document outlet  122 . The first guide rib  131  and the second guide rib  132  may have a guide surface  133  facing the document feed path  123 . The guide surface  133  guides the leading end of the document moving through the document feed path  123  such that the document may smoothly pass over the first guide rib  131  and the second guide rib  132 . As seen in the embodiment shown in  FIG. 3 , the guide surface  133  may be formed in a convexly curved surface inclined upward in the moving direction of the document. 
     The first guide rib  131  may be disposed at one side of the document outlet  122  to slightly lift up one widthwise end portion of the document discharged through the document outlet  122 , and the second guide rib  132  may be disposed at the other side of the document outlet  122  to slightly lift up the other end portion of the document. When the trailing end portion of the document is lifted up by the first guide rib  131  and the second guide rib  132 , the trailing end portion of the document is unstably supported in the document outlet  122 , and the document can be easily separated from the document outlet  122 . 
       FIG. 4  illustrates an example of a document discharge process according to an embodiment of the invention. A trailing end portion DT of a document D 1  may remain in the document outlet  122 . The curl generated on the trailing end portion DT of the document D 1  by the first guide rib  131  and the second guide rib  132  may allow the leading end portion DL of the next discharged document D 2  to push the document D 1  through the document outlet  122 . Thus, it is possible to prevent a document jam or shuffle. 
       FIG. 5  depicts an alternate embodiment of the invention. In this embodiment, a multi-functional machine  2  may include a first guide rib  131   a  and a second guide rib  132   a  which are disposed at central portions of the document outlet  122  to slightly lift a central portion of the document discharged through the document outlet  122 . Although this embodiment has a difference in the shape of the curl generated in the document from the embodiment of  FIG. 2 , namely the direction of the curl, the document discharging is carried out in substantially the same manner as the embodiment of  FIG. 2  and  FIG. 4 . That is, when a document is stalled at the document outlet  122 , the curl generated on the trailing end portion DT of the document D 1  by the first guide rib  131   a  and the second guide rib  132   a  may allow a leading end portion DL of the next discharged document D 2  to push the document D 1  through the document outlet  122 . 
     Although two guide ribs are installed on the document outlet in the above embodiments, the number of the guide ribs may vary. For example, the embodiment shown in  FIG. 6  contains one guide rib  131   c  installed on the document outlet  122 . The guide rib  131   c  may be installed at the central portion of the document outlet  122  to slightly lift up the central portion of the document discharged through the document outlet  122 , and produce a curl. However, the guide rib  131   c  may alternatively be disposed on the left or right side of the document outlet  122 , and perform substantially the same function. 
     Although embodiments of the present invention have been shown and described, those skilled in the art can appreciate that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.

Technology Classification (CPC): 1