Abstract:
An image forming apparatus includes: a housing accommodating an image forming unit and includes a side wall and an opening to feed the sheet from an outside to the image forming unit; a feeding tray moving between a holding position and an accommodation position; a guide provided at the feeding tray, the guide being configured to abut against the sheet which is held on the feeding tray from a rear end side of the sheet in a feeding direction along with the sheet is fed to the image forming unit and define a holding position of the sheet when the feeding tray is arranged at the holding position and the sheet is placed on the feeding tray; and a recess part formed on the sidewall of the housing and configured to accommodate the guide therein when the feeding tray is arranged at the accommodation position.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority of Japanese Patent Application No. 2012-018610 filed on Jan. 31, 2012, the contents of which are incorporated herein by reference in its entirety. 
     BACKGROUND 
     The present disclosure relates to an image forming apparatus having an image forming unit that forms an image on a recording medium, and more particularly, to an image forming apparatus that swingably supports a feeding tray, which holds therein a recording medium on which an image is formed by the image forming unit, on one side surface of a housing of the image forming apparatus. 
     In the related art, an image forming apparatus forming an image on a recording medium has been suggested which swingably supports a feeding tray, which holds therein a recording medium such as recording sheet on which an image is formed, via a hinge and the like so as to reduce a setup space when the age forming apparatus is not used. In this case, when the feeding tray is not used, it is possible to accommodate the feeding tray along a side surface of a housing (for example, refer to JP-A-2010-55126). 
     SUMMARY 
     According to the above image forming apparatus, however, it may be necessary to provide the feeding tray with a guide that defines a holding position of the recording medium. In particular, when a guide that abuts on the recoil medium from a rear end side of the medium in a feeding direction to an image forming unit is provided, the guide should be configured to move on the feeding tray so as to define a rear end position of a recording medium having a different size. A rear end position of a recording medium tray protrude from the feeding tray, depending on a size of the recording medium. In this case, an extension mechanism that extends the guide from the feeding tray is required so as to support the rear end of the recording medium. At a state where the guide is arranged at the rear end position of the recording medium, when accommodating the feeding tray along a side surface of the housing, the side surface interferes with the guide. 
     Therefore, it is considered to configure the guide so that it can be moved to a position (hereinafter, referred to as ‘opening neighborhood’) at which the guide can be opposed to an opening, which is provided to feed the recording medium to the image forming unit in the housing, upon the accommodation. In this case, when accommodating the feeding tray along the side surface of the housing, the extension mechanism is returned above the feeding tray from the extension position, the guide is moved to the opening neighborhood and the feeding tray can be then accommodated. At this time, since the guide is inserted into the opening, the guide does not interface with the side surface of the housing. 
     However when the above configuration is adopted, after operating the extension mechanism, it is necessary to move the guide to the opening neighborhood and then to accommodate the feeding tray, so that the user&#39;s convenience is deteriorated. When the guide is provided to the feeding tray so that the guide can be moved to the opening neighborhood, the configuration is complicated, so that the manufacturing cost of the image forming apparatus is increased. 
     Therefore, an object of one aspect of the present disclosure is to improve on user&#39;s convenience of an image forming apparatus in which a feeding tray holding therein a recording medium is swingably provided on one side surface of a housing. 
     An image forming apparatus according to the aspect of the present disclosure includes: 
     an image forming unit configured to form an image on a sheet; 
     a housing configured to accommodate the image forming unit therein and includes a sidewall which forms at least a part of a first side surface of the housing, and an opening which is arranged at a lower part of the sidewall so as to feed the sheet from an outside to the image forming unit, the sidewall and the opening being formed on the first side surface; 
     a feeding tray swingably supported by the housing and configured to move between a holding position at which the sheet which is fed to the image forming unit through the opening is held and an accommodation position at which the feeding tray closes the opening; 
     a guide provided at the feeding tray, the guide being configured to abut against the sheet which is held on the feeding tray from a rear end side of the sheet in a feeding direction along with the sheet is fed to the image forming unit and define a holding position of the sheet when the feeding tray is arranged at the holding position and the sheet is placed on the feeding tray; and 
     a recess part formed on the sidewall of the housing and configured to accommodate the guide therein when the feeding tray is arranged at the accommodation position. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of an outward appearance of a laser printer. 
         FIG. 2  is a perspective view of the outward appearance of the laser printer showing a state where respective covers are opened. 
         FIG. 3  is a central sectional view schematically showing an internal configuration of the laser printer. 
         FIG. 4A  is a front view of the laser printer. 
         FIG. 4B  is a sectional view taken along a line A-A of  FIG. 4A . 
         FIG. 5A  is a side view of the laser printer. 
         FIG. 5B  is a sectional view taken along a line B-B of  FIG. 5A . 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     [Overall Configuration of Laser Printer] 
     Hereinafter, an exemplary embodiment will be described with reference to the drawings.  FIG. 1  is a perspective view of an outward appearance of a laser printer  1  serving as the image forming apparatus. Meanwhile, in the below descriptions, the directions are described on the basis of a user who uses the laser printer  1 . That is, in  FIG. 1 , the left-front side of the sheet is referred to as the ‘front side’, the right-inner side of the sheet is referred to as the ‘rear side’, the left-inner side of the sheet is referred to as the ‘left side’ and the right-front side of the sheet is referred to as the ‘right side.’ The upper-lower direction of the sheet is referred to as the ‘upper-lower direction.’ 
     As shown in  FIG. 1 , the laser printer  1  has a housing  2  of a substantially rectangular parallelepiped shape and has a sheet feeding cover  23  (which is an example of the feeding tray) at a front side part of the housing  2  and a sheet discharge cover  26  at an upper part thereof so that they can be respectively opened and closed.  FIG. 2  is a perspective view of the out and appearance of the laser printer  1  showing a state where the sheet feeding cover  23  and the sheet discharge cover  26  are opened. As shown in  FIGS. 1 and 2 , the sheet feeding cover  23  is connected to a lower end of a front side wall  22 , which is a sidewall of one side surface of the housing  2 , via a hinge  23 A. The sheet feeding cover  23  swings about a shaft of the hinge  23 A, so that it can be moved to an accommodation position at which the t feeding cover accommodated along the front side wall  22 , as shown in  FIG. 1 , and to a holding position at which the sheet feeding cover is connected to a tray part  21  in the same plane shape, which tray part is arranged at a lower pan of the housing  2 , and holds a sheet P (refer to  FIG. 3 : an example of the recording medium), as shown in  FIG. 2 . 
     The sheet feeding cover  23  is provided with a rear guide  24  (which is an example of the guide) that abuts on a rear end of the sheet P, which is held on the sheet feeding cover  23 , in a conveyance direction when the sheet feeding cover  23  is arranged at the holding position. In the meantime, as shown in  FIG. 2 , the rear guide  24  has a slide pan that slides along the sheet feeding cover  23 . The rear guide  24  can be moved between a reception position shown with the solid line in  FIG. 2  and a pullout position shown with the dashed-two dotted line in  FIG. 2  and more pulled out in a free end direction of the sheet feeding cover  23  beyond the sheet feeding cover  23 . That is, the rear guide  24  can be moved to a preferable position and then used in accordance with a length of the sheet P in the conveyance direction, which is put on the sheet feeding cover  23 . 
     In the meantime, the sheet discharge cover  26  is supported so that it can be swung to an open position (refer to  FIG. 2 ) at which the sheet discharge cover  26  is connected to a sheet discharge tray  25  in the same plane shape, which is provided to the upper part of the housing  2  so that the sheet discharge tray is inclined upwardly towards the front, and a close position (refer to  FIG. 1 ) at which the sheet discharge cover  26  covers the sheet discharge cover  25  from the upper. Upon the image formation of the laser printer  1 , the sheet feeding cover  23  is arranged at the holding position and the sheet discharge cover  26  is arranged at the open position, respectively. An end edge of a free end-side of the sheet feeding cover  23  (i.e., an end edge of an opposite side to a side of the sheet feeding cover  23  that is swingably supported) is formed with a notch  23 B for laying a user&#39;s hand thereon when swinging the sheet feeding cover  23 . The front side wall  22  is formed with a recess part  29  at a position at which the recess part is opposed to the rear guide  24  and notch  23 B when the sheet feeding cover  23  is arranged at the accommodation position. The configuration and effects of the recess part  29  will be specifically described later. 
     [Internal Configuration of Laser Printer] 
       FIG. 3  is a central sectional view schematically showing an internal configuration of the laser printer  1 . As shown in  FIG. 3 , the laser printer  1  has, in the housing  2 , a feeder unit  3  for feeding the sheet P and an image forming unit  4  for forming an image on the sheet P. 
     The feeder unit  3  has a sheet feeding tray  31  that is provided at a lower part of the housing  2  and a sheet feeding mechanism  32  that feeds the sheet P on the sheet feeding tray  31  towards the image forming unit  4 . 
     The sheet feeding mechanism  32  has a pickup roller  100  that picks up the sheet P and the other oilers that convey the picked up sheet P towards the image forming unit  4 . 
     The sheet feeding tray  31  has the tray part  21  that is arranged at the lower part of the housing  2  and the sheet feeding cover  23  that is arranged at the holding position. 
     The tray part  21  has a pressing plate  21 A that is connected to the housing  2  via a hinge  21 B and a spring  21 C that pushes the pressing plate  21 A towards the roller  100 . 
     The housing  2  is formed at the lower part thereof with an opening  22 A. At a lower part of the opening  22 A, the sheet feeding cover  23  is connected via the hinge  23 A. 
     The sheet P is put on the sheet feeding tray  31  through the opening  22 A. That is, in the feeder unit  3 , the sheet feeding cover  23  is arranged at the holding position, so that the sheet feeding tray  31  is formed. After that the sheet P is put on the sheet feeding tray  31 . The spring  21 C pushes the pressing plate  21 A towards the roller  100 , thereby bringing the sheet P put on the pressing plate  21 A into contact with the roller  100  with a favorable force. 
     The image forming unit  4  has a scanner unit  5 , which is an example of the exposure unit, a process unit  6 , which is an example of the process unit and a fixing unit  7 . The scanner unit  5  has a laser emitting unit, a polygon mirror, a lens, a reflector and the like, which are not shown. The scanner unit  5  is provided at the front-upper part in the housing  2 . The scanner unit  5  is arranged so that an emission position of a laser beam is lower than a lower end of the sheet discharge tray  25 , and emits the laser beam in a substantially horizontal direction. The scanner unit  5  emits and scans the laser beam on a surface of a photosensitive drum  61  that is an example of the photosensitive member (which will be described later). 
     Here, as shown in  FIG. 3 , the pressing plate  21 A extends from a neighborhood of the opening  22 A to a neighborhood of the roller  100  in the housing  2  and a distance L 1  from the hinge  21 B to the hinge  23 A is shorter than a distance L 2  from the hinge  21 B to the roller  100 . With this configuration, it is possible to increase a contact length of the pressing plate  21 A with the sheet P as long as possible. As a result, it is possible to press the sheet P towards the roller  100  while stably holding the sheet P put on the pressing plate  21 A. 
     The process unit  6  has a photosensitive drum  61 , a charge wire  62  that charges the photosensitive drum  61  by discharge, a transfer roller  63  that transfers a toner image (developer image on the photosensitive drum  61  to the sheet P and a process-side housing  8 . In the process-side housing  8 , the photosensitive drum  61 , the charge wire  62  and the transfer roller  63  are accommodated and a toner accommodation chamber, a developing roller and the like (which are well known and are not shown) are provided. 
     In the process unit  6 , when it is detected that the sheet P is conveyed, a surface of the photosensitive drum  61  being swung is uniformly charged by the charge wire  62 . After that, the surface of the photosensitive drum  61  is exposed by the high-speed scanning of the laser beam emitted from the scanner unit  5 . Thereby, a potential of the exposed part is lowered, so that an electrostatic latent image based on image data is formed on the surface of the photosensitive drum  61 . Then, the toner in the toner accommodation chamber is supplied to the electrostatic latent image on the photosensitive drum  61  by the developing roller, so that a toner image is formed on the surface of the photosensitive drum  61 . Then, the sheet P is conveyed between the photosensitive drum  61  and the transfer roller  63 , so that the toner image carried on the surface of the photosensitive drum  61  is transferred onto the sheet P. 
     The fixing unit  7  is arranged above (just above) the process unit  6 . Thereby, a conveyance path A 1  of the sheet P from the process unit  6  to the fixing unit  7  is formed to extend in a substantially vertical direction. Here, the ‘conveyance path A 1 ’ means a space through which the sheet P passes. 
     The fixing unit  7  has a heating roller  71 , a pressing roller  72  and a fixing housing  9  accommodating therein the heating roller  71 . The heating roller  71  is a member that heats the sheet P and is provided therein with a heat source (not shown) such as a halogen lamp. The pressing roller  72  is a member that sandwiches and conveys the sheet P between the pressing roller  72  and the heating roller  71  and is provided obliquely upwards at the rear of the heating roller  71 . 
     In the fixing unit  7  configured as described above, the toner transferred on the sheet P is heat-fixed while the sheet P passes between the heating roller  71  and the pressing roller  72 . In the meantime, the sheet P heat-fixed by the fixing unit  7  is conveyed towards sheet discharge rollers R that are arranged at a downstream side of the fixing unit  7  and is then discharged onto the sheet discharge tray  25  from the sheet discharge rollers R. 
     [Configuration and Effects around Recess Part of Laser Printer] 
     As described above, the sheet discharge tray  25  is provided to the upper part of the housing  2  so that the sheet discharge tray is inclined upwardly towards the front. Thereby, the sheet P that is discharged onto the sheet discharge tray  25  is loaded well. The scanner unit  5  is provided at an inside of the front side of the housing  2 , i.e., at an inside of the front side wall  22 . Since the emission position of the laser beam of the scanner unit  5  is set to be lower than the lower end of the sheet discharge tray  25 , a space is formed between the sheet discharge tray  25  and the scanner unit  5 . The recess part  29  is formed to enter a dead space between the sheet discharge tray  25  and the scanner unit  5  and accommodates therein the rear guide  24  when the sheet feeding cover  23  is arranged at the accommodation position, as shown with the dashed-two dotted line in  FIG. 3 . When the sheet feeding cover  23  is arranged at the accommodation position, the opening  22 A that is formed at the lower part of the front side wall  22  is closed by the sheet feeding cover  23 . 
     In the meantime, the rear guide  24  is slid as shown in  FIG. 2 , so that a sheet P of an A4 size, a sheet P of a letter size and a sheet P of a legal size can be put on the sheet feeding tray  31 . The recess part  29  is provided at a position at which the rear guide  24  is accommodated therein if the sheet feeding cover  23  is closed at a state where ear guide  24  is arranged near to an end edge of the notch  23 B facing the hinge  23 A (refer to the solid line in  FIG. 2 ) so as to define a holding position of the sheet P of a letter size. Therefore, even though the rear guide  24  is not moved to the neighborhood of the opening  22 A, it is possible to suppress the interference between the rear guide  24  and the front wall  22 . As a result, it is possible to improve the user&#39;s convenience and to reduce the manufacturing cost of the laser printer  1 . 
     That is, if the rear guide  24  is configured so that when the sheet feeding cover  23  is closed, the rear guide  24  is moved to a position at which the rear guide  24  is inserted into the opening  22 A, it may be possible to suppress the rear guide  24  from interfering with the front side wall  22  when closing the sheet feeding cover  23 , even without the recess part  29 . However, when such configuration is adopted, the configuration of the apparatus is complicated, so that the manufacturing cost of the laser printer  1  is increased. When closing the sheet feeding cover  23 , it is necessary to move the rear guide  24 , so that the user&#39;s convenience is also deteriorated. Compared to this, according to this illustrative embodiment, the recess part  29  is provided, as described above, so that it is possible to improve the user&#39;s convenience and to reduce the manufacturing cost of the laser printer  1 . 
     As shown in  FIGS. 4B and 5B . the housing  2  is provided therein with a left frame  91  and a right frame  92  that support the image forming unit  4  from both left and right sides thereof. An neighborhood of a front end of the left frame  91  is formed with a depression portion  91 A and a motor  93  for driving the process unit  6  and the like is mounted in the depression portion. As shown in  FIGS. 4A to 5B , the recess part  29  is provided at a position at which it overlaps with the motor  93  in the left-right direction. As described above, the recess part  29  is arranged in the dead space between the sheet discharge tray  25  and the scanner unit  5  and overlaps with the motor  93  in the left-right direction. Therefore, according to the laser printer  1 , it is possible to effectively use a space in the housing  2  and to thus miniaturize the laser printer. 
     According to the laser printer  1 , it is possible to swing the sheet feeding cover  23  with laying a user&#39;s hand on the notch  23 B, so that it is possible to swing the sheet feeding cover  23  more easily. The notch  23 B is opposed to the recess part  29  when the sheet feeding cover  23  is arranged at the accommodation position, as shown in  FIG. 1 . Therefore, the operation of swinging the sheet feeding cover  23  to the holding position with laying the user&#39;s hand on the notch  23 B becomes further easier. 
     As pictorially shown in  FIG. 3 , an upper inner wall  29 A of the recess part  29  is inclined upwardly towards the front. Therefore, the following additional effects are obtained. That is, as described above, according to the laser printer  1 , the process unit  6  and the like are lopsidedly provided towards the rear and the general center of gravity of the laser printer  1  is also lopsided rearwards. Therefore, when a force of pulling up the recess part  29  is applied with laying the user&#39;s hand on the recess part  29 , the setup state (posture) of the laser printer  1  may be unstable. 
     Compared to this, according to this illustrative embodiment, the upper inner wall  29 A of the recess part  29  is inclined as described above. Thus, even when an operation of pulling up the recess part  29  is performed with laying the user&#39;s hand on the recess part  29 , the hand slips from the recess part  29 , so that it is difficult to pull up the recess part  29 . Thereby, it is possible to stably keep the setup state (posture) of the laser printer  1 . As described above, according to this illustrative embodiment, since it is difficult to apply the pulling-up force to the front side of the laser printer  1 , it is possible to reduce the rigidity of the front side of the housing  2  to which the weighty load is not applied so much. Thus, it is also possible to reduce the total weight and manufacturing cost of the laser printer  1 . 
     In the meantime, the invention is not limited to the above illustrative embodiment and can be variously implemented without departing from the gist of the invention. For example, the rear guide  24  may be integrated with the sheet feeding cover  23  and is thus not moved. The feeding tray of the invention may be supported so that it can swing about a position below the opening. Regarding the image forming unit of the invention, a variety of image forming units may be adopted. For example, a printer engine of a color laser printer and a printer engine of an inkjet printer may be adopted. Regarding the recording medium of the invention, a variety of recording media such as OHP sheets may be adopted.