Abstract:
An image forming apparatus includes: a body frame accommodating an image forming unit; and a support frame supporting an image reading unit and disposed to confront the body frame in a confronting direction, the support frame having a first end portion and a second end portion opposite to each other in a first direction perpendicular to the confronting direction. The support frame includes: first and second engaging portions provided at the first and second end portions respectively; and a pair of grip portions. The body frame has a first edge portion and a second edge portion opposite to each other in the first direction, the body frame including: a first engaged portion provided at the first edge portion and engageable with the first engaging portion; and a second engaged portion provided at the second edge portion and engageable with the second engaging portion.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority from Japanese Patent Application No. 2011-254921 filed Nov. 22, 2011. The entire content of the priority application is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present invention relates to an electrophotographic image forming apparatus. 
     BACKGROUND 
     There is known in the art an image forming apparatus that includes an image-forming unit for forming images on paper, and an image-reading unit assembled above the image-forming unit for reading images from originals. One such image forming apparatus that has been proposed includes a device body accommodating the image-forming unit, and a scanning unit accommodating the image-reading unit and disposed above the device body. 
     In the conventional image forming apparatus described above, the scanning unit is mounted on the device body by first inserting a plurality of hooks provided in a center region of the device body through a plurality of corresponding fitting holes formed in the scanning unit and by subsequently sliding the scanning unit relative to the device body to secure the hooks in the fitting holes. Thereafter, the device body and scanning unit are fastened together with side plates or screws. 
     SUMMARY 
     However, when a user lifts this conventional image forming apparatus by holding the scanning unit, the hooks may shift relative to the fitting holes, causing the connection between the scanning unit and the device body to loosen and become unsteady. When the device body shifts relative to the scanning unit, load applied on the hooks increases by an amount proportionate to the degree of shift. 
     In view of the foregoing, it is an object of the present invention to provide an image forming apparatus having a body frame accommodating an image-forming unit, and a support frame accommodating an image-reading unit, the image forming apparatus being configured to prevent an unsteady fit between the support frame and body frame, even when a user grips the apparatus by the support frame. 
     In order to attain the above and other objects, there is provided an image forming apparatus including: an image forming unit configured to form images; an image reading unit configured to read images of an original; a body frame accommodating the image forming unit therein; and a support frame supporting the image reading unit and disposed to confront the body frame in a confronting direction. The support frame has a first end portion and a second end portion opposite to each other in a first direction perpendicular to the confronting direction, the support frame including: a first engaging portion provided at the first end portion; a second engaging portion provided at the second end portion; and a pair of grip portions each provided at each of the first end portion and the second end portion. The body frame has a first edge portion and a second edge portion opposite to each other in the first direction, the first edge portion and the second edge portion confronting the first end portion and the second end portion respectively when the support frame is assembled to the body frame, the body frame including: a first engaged portion provided at the first edge portion and configured to be engaged with the first engaging portion; and a second engaged portion provided at the second edge portion and configured to be engaged with the second engaging portion. 
     According to another aspect of the present invention, there is provided an image forming apparatus including: an image forming unit configured to form images; an image reading unit configured to read images of an original; a body frame accommodating the image forming unit therein; and a support frame supporting the image reading unit and disposed to confront the body frame in a confronting direction. The support frame has a first end portion and a second end portion opposite to each other in a first direction perpendicular to the confronting direction, the support frame including: a first engaging portion provided at the first end portion; a first protruding portion provided at the first end portion and positioned outward than the first engaging portion in the first direction; a second engaging portion provided at the second end portion; and a second protruding portion provided at the second end portion and positioned outward than the second engaging portion in the first direction. The body frame has a first edge portion and a second edge portion opposite to each other in the first direction, the first edge portion and the second edge portion confronting the first end portion and the second end portion respectively when the support frame is assembled to the body frame. The body frame includes: a first engaged portion provided at the first edge portion and configured to be engaged with the first engaging portion; and a second engaged portion provided at the second edge portion and configured to be engaged with the second engaging portion. The first protruding portion and the second protruding portion protrude outward than the first edge portion and the second edge portion in the first direction respectively when the support frame is assembled to the body frame. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The particular features and advantages of the invention as well as other objects will become apparent from the following description taken in connection with the accompanying drawings, in which: 
         FIG. 1  is a perspective view of a printer according to a first embodiment of the present invention as viewed from upward and rightward thereof; 
         FIG. 2  is an exploded perspective view of the printer of  FIG. 1 , the printer including a tray-forming member and a support frame; 
         FIG. 3  is a perspective view of the tray-forming member shown in  FIG. 2  as viewed from upward and rearward thereof; 
         FIG. 4  is a perspective view of the support frame shown in  FIG. 2  as viewed from below and leftward thereof; 
         FIG. 5  is an explanatory view showing how the support frame of  FIG. 2  is assembled to the tray-forming member of  FIG. 2 , in which support-frame-side hooks of the support frame are in engagement with body-side hooks of the tray-forming member; 
         FIG. 6  is a perspective view of the tray-forming member and the support frame as viewed from rearward and rightward thereof; 
         FIG. 7  is a perspective view of the tray-forming member and the support frame of  FIG. 6  as viewed from rearward and leftward thereof; 
         FIG. 8  is a vertical cross-sectional view of the tray-forming member and the support frame of  FIG. 6 ; 
         FIG. 9A  is an explanatory view showing how a communication circuit board is assembled to a retaining part of the tray-forming member of  FIG. 2 , in which the communication circuit board is engaged with first engaging portions of the retaining part; 
         FIG. 9B  is an explanatory view showing how the communication circuit board is assembled to the retaining part of the tray-forming member of  FIG. 2 , in which the communication circuit board has been assembled to the retaining part; and 
         FIG. 10  is a perspective view of a support frame according to a second embodiment of the present invention as viewed from below and leftward thereof. 
     
    
    
     DETAILED DESCRIPTION 
     1. Overall Structure of a Printer 
     Hereinafter, a printer  1  as an example of an image-forming apparatus according to a first embodiment of the present invention will be described with reference to  FIGS. 1 through 9 . 
     As shown in  FIG. 1 , the printer  1  is a multifunction device and includes a main casing  2 , and a scanning unit  3  provided above the main casing  2  for reading image data of an original. 
     The main casing  2  has a general box shape. An access opening  6  is formed in one side wall of the main casing  2 . A front cover  7  is pivotably provided on the same side wall of the main casing  2  in which the access opening  6  is formed. The front cover  7  is capable of pivoting about its lower end between a closed position for covering the access opening  6 , and an open position for exposing the access opening  6 . 
     In the following description, when referencing directions relative to the printer  1 , the side of the printer  1  on which the front cover  7  is provided will be called the “front side,” while the opposite side will be called the “rear side.” More specifically, forward, rearward, upward, downward, leftward, and rightward directions relative to the printer  1  will conform to directional arrows indicated in each drawing. 
     The main casing  2  accommodates a sheet-feeding unit  4  configured to feed sheets of paper, and an image-forming unit  5  (see  FIG. 2 ) configured to form images on the paper supplied by the sheet-feeding unit  4 . 
     The sheet-feeding unit  4  is disposed at a lower end portion of the main casing  2  and includes a paper tray  9  that accommodates sheets of paper. 
     The paper tray  9  is removably mounted in a bottom portion of the main casing  2 . 
     The image-forming unit  5  is disposed above the sheet-feeding unit  4  (see  FIG. 2 ). 
     When the sheet-feeding unit  4  supplies a sheet of paper from the paper tray  9  to the image-forming unit  5 , the image-forming unit  5  forms an image on the sheet. Subsequently, the sheet is discharged through a discharge opening  63  (see  FIG. 2 ) formed in the main casing  2 , and the sheet is received by a discharge tray  8  formed on a top surface of the main casing  2 . 
     The scanning unit  3  is disposed above the main casing  2  and confronts the top surface of the main casing  2  so as to cover the discharge tray  8 . The scanning unit  3  is generally rectangular in a plan view and has substantially the same front-rear and left-right dimensions as the main casing  2 . 
     2. Main Casing 
     As shown in  FIGS. 1 and 2 , the main casing  2  includes a tray-forming member  13 , and a pair of left and right side walls  12 . 
     (1) Detailed Description of the Tray-Forming Member 
     The tray-forming member  13  is formed of a resin material and has a generally rectangular frame-like shape in a plan view, as illustrated in  FIGS. 2 and 3 . More specifically, the tray-forming member  13  is integrally provided with a right wall section  15  and a left wall section  16  arranged parallel to each other and separated in a left-right direction, a rear wall section  17  connecting rear ends of the right wall section  15  and left wall section  16 , and a bottom plate  65  surrounded by the right wall section  15 , left wall section  16 , and rear wall section  17  and connecting lower ends of the right wall section  15  and left wall section  16 . 
     (1-1) Right Wall Section 
     The right wall section  15  is generally rectangular in a side view and elongated in a front-rear direction. The right wall section  15  includes two body-side hooks  18 , and two first boss holes  19 . 
     The two body-side hooks  18  are provided on a right edge of the right wall section  15  so as to be spaced apart from each other in the front-rear direction. Each body-side hook  18  integrally includes a hook-shaped portion  20  and a reinforcing portion  21 . 
     The hook-shaped portion  20  is generally L-shaped in a front view and extends upward from an upper surface of the right wall section  15 . More specifically, the hook-shaped portion  20  includes an erect part  22  that extends upward from an upper edge portion of the right wall section  15 , and an extended part  23  that extends leftward from an upper end portion of the erect part  22 . 
     The reinforcing portion  21  has a flat plate shape and is generally rectangular in a front view. The reinforcing portion  21  is positioned so as to close a space defined by the upper surface of the right wall section  15 , the erect part  22 , and the extended part  23  when viewing the hook-shaped portion  20  from the front side. More specifically, the reinforcing portion  21  of the front body-side hook  18  is positioned so as to connect rear edges of the corresponding erect part  22  and extended part  23 . The reinforcing portion  21  of the rear body-side hook  18  is positioned so as to connect the front edges of the corresponding erect part  22  and extended part  23 . 
     The two first boss holes  19  are formed in the upper surface of the right wall section  15  near a left edge thereof and are spaced apart in the front-rear direction. More specifically, the front first boss hole  19  is disposed obliquely leftward and rearward of the front body-side hook  18 , while the rear first boss hole  19  is disposed obliquely leftward and forward of the rear body-side hook  18 . 
     The front first boss hole  19  is an elongate hole that is elongated in the left-right direction. The front first boss hole  19  has a front-rear dimension approximately equal to a diameter of a corresponding boss  47  (described later), while has a left-right dimension greater than that of the boss  47 . 
     The rear first boss hole  19  is generally rectangular in a plan view and is elongated in the left-right direction. The rear first boss hole  19  has a front-rear dimension approximately equal to the diameter of the corresponding boss  47  (described later), while has a left-right dimension greater than an outer diameter of the boss  47 . 
     (1-2) Left Wall Section 
     As shown in  FIGS. 3 and 5 , the left wall section  16  is generally rectangular in a side view and elongated in the front-rear direction. The left wall section  16  has, on its left surface, two snapping protrusions  24  (see  FIG. 5 ), two second boss holes  25 , and a retaining part  29  (see  FIG. 5 ). 
     As shown in  FIG. 5 , the two snapping protrusions  24  are provided on the left surface of the left wall section  16  and are spaced apart in the front-rear direction. The snapping protrusions  24  have a generally square columnar shape and protrude leftward from the left surface of the left wall section  16 . Each snapping protrusion  24  has a top surface that slopes downward toward the left. A screw hole  26  is formed in the center of each snapping protrusion  24 . 
     As shown in  FIG. 3 , the two second boss holes  25  are formed in the top surface of the left wall section  16  near a right edge thereof and are spaced apart in the front-rear direction. Specifically, the front second boss hole  25  is positioned obliquely rightward and rearward of the front snapping protrusion  24 , while the rear second boss hole  25  is positioned obliquely rightward and forward of the rear snapping protrusion  24 . Each second boss hole  25  is generally circular in a plan view, and has an inner diameter slightly larger than the outer diameter of the corresponding boss  47  (described later). 
     As shown in  FIGS. 5 and 9 , the retaining part  29  is provided in the left surface of the left wall section  16  at a front-rear center thereof for holding a communication circuit board  28  (described later). The retaining part  29  is generally rectangular in a side view and is depressed rightward (inward) relative to the left surface of the left wall section  16 . The retaining part  29  includes two first engaging portions  33 , a restricting wall  34 , and a second engaging part  35 . 
     The two first engaging portions  33  are provided for engaging a bottom edge of the communication circuit board  28  (described later). The two first engaging portions  33  are spaced apart in the front-rear direction, and protrude upward from a bottom wall of the retaining part  29  near a left end thereof. The first engaging portions  33  have a flat plate shape that is generally rectangular in a side view and elongated in the left-right direction. 
     The restricting wall  34  serves to restrict movement of a front edge of the communication circuit board  28 . The restricting wall  34  has a flat plate shape and is generally rectangular in a rear view. The restricting wall  34  extends leftward from a right wall of the retaining part  29 . 
     The second engaging part  35  is provided for engaging a top edge of the communication circuit board  28 . The second engaging part  35  has a flat plate shape and is generally rectangular in a plan view. The second engaging part  35  protrudes leftward from the right wall of the retaining part  29 . A hole is formed in a front-rear center region of the second engaging part  35  and is elongated in the left-right direction. The second engaging part  35  is disposed above the bottom wall of the retaining part  29  so as to be separated from the same by a distance equivalent to a height of the communication circuit board  28  (described later). 
     (1-3) Rear Wall Section 
     As shown in  FIGS. 3 and 5 , the rear wall section  17  is generally rectangular in a plan view and elongated in the left-right direction. The rear wall section  17  has a left surface from which a snap-receiving part  27  protrudes leftward. Specifically, the snap-receiving part  27  is formed on the left surface at a position adjacent to a left and rear edge thereof. 
     The snap-receiving part  27  has a square pillar shape and is generally rectangular in a rear view. The snap-receiving part  27  has a thickness in the front-rear direction and has a rear surface in which a screw hole  38  is formed to penetrate therethrough in the front-rear direction. 
     (1-4) Bottom Plate 
     As shown in  FIG. 3 , the bottom plate  65  is generally rectangular in a plan view and includes a sloping part  42 , and a level part  43 . 
     The sloping part  42  is generally rectangular in a plan view and slopes downward toward the rear (toward the image-forming unit  5 ) from an approximate front-rear center portion of the bottom plate  65 . 
     The level part  43  is generally rectangular in a plan view and extends forward from the approximate front-rear center portion of the bottom plate  65 . 
     The right wall section  15 , left wall section  16 , rear wall section  17 , and bottom plate  65  constitute the discharge tray  8 . 
     (2) Detailed Description of the Side Walls 
     The side walls  12  are formed of a resin material. As shown in  FIGS. 1 and 2 , the side walls  12  have a flat plate-like shape and are generally rectangular in a side view. The side walls  12  are arranged parallel to each other and are spaced apart in the left-right direction for covering the respective left and right sides of the image-forming unit  5  and tray-forming member  13 . The tray-forming member  13  is provided so as to link upper end portions of the side walls  12 . Top edges of the side walls  12  are substantially flush with the top edges of the tray-forming member  13 . 
     A recessed part  14  is formed in a top end portion of each side wall  12  at a position center thereof in the front-rear direction. In a plan view, the recessed parts  14  have a general U-shape that opens on the respective left or right outer side thereof. The recessed parts  14  are depressed inward relative to outer surfaces of the corresponding side walls  12 . The recessed parts  14  are also open on the top. 
     3. Scanning Unit 
     The scanning unit  3  includes an image-reading unit  10 , and a support frame  11  that supports the image-reading unit  10  on its bottom, as shown in  FIG. 2 . 
     The image-reading unit  10  reads image data of an original after the original is placed between an original cover  44  and a glass surface (not shown). 
     As shown in  FIG. 4 , the support frame  11  has a flat plate-like shape and is generally rectangular in a plan view. The support frame  11  includes two support-frame-side hooks  45 , two recessed snap parts  46 , a snap hook part  48  (see  FIG. 5 ), four bosses  47 , and two grip parts  49 . 
     (1) Detailed Description of the Support-Frame-Side Hooks 
     The two support-frame-side hooks  45  are provided on a bottom surface of the support frame  11  near the right edge thereof, and are spaced apart from each other in the front-rear direction. Each support-frame-side hook  45  is integrally provided with a hook-shaped portion  50 , and a reinforcing portion  51 . 
     The hook-shaped portion  50  is generally L-shaped in a front view. Specifically, the hook-shaped portion  50  includes an erect part  52  extending downward from the bottom surface of the support frame  11  near the right edge thereof, and an extended part  53  that extends rightward from a bottom edge of the erect part  52 . 
     The reinforcing portion  51  has a flat plate shape and is generally rectangular in a front view. The reinforcing portion  51  is disposed so as to close a space defined by the bottom surface of the support frame  11 , the erect part  52 , and the extended part  53  when viewing the hook-shaped portion  50  from the front side. More specifically, the reinforcing portion  51  of the front support-frame-side hook  45  is arranged so as to connect front edges of the erect part  52  and the extended part  53  constituting the front support-frame-side hook  45 , while the reinforcing portion  51  of the rear support-frame-side hook  45  is arranged so as to connect rear edges of the erect part  52  and the extended part  53  constituting the rear support-frame-side hook  45 . 
     (2) Detailed Description of the Recessed Snap Parts 
     The two recessed snap parts  46  are disposed on the bottom surface of the support frame  11  near the left edge thereof and are spaced away from each other in the front-rear direction. The recessed snap parts  46  have a flat plate shape and are generally rectangular in a side view. The recessed snap parts  46  extend downward from the bottom surface of the support frame  11 . The recessed snap parts  46  are so configured as to be resiliently deformable in the left-right direction. A first through-hole  54  is formed in a bottom end portion of each recessed snap parts  46  at a position center thereof in the front-rear direction. The recessed snap parts  46  are capable of receiving the corresponding snapping protrusions  24 . 
     (3) Detailed Description of the Bosses 
     The four bosses  47  are provided on the bottom surface of the support frame  11  and are spaced apart in the front-rear and left-right directions, forming four corners of a rectangle. The bosses  47  are generally columnar in shape and protrude downward from the bottom surface of the support frame  11 . 
     More specifically, the right-front boss  47  is disposed obliquely leftward and rearward of the front support-frame-side hook  45 ; the right-rear boss  47  is disposed obliquely leftward and forward of the rear support-frame-side hook  45 ; the left-front boss  47  is disposed obliquely rightward and rearward of the front recessed snap parts  46 ; and the left-rear boss  47  is disposed obliquely rightward and forward of the rear recessed snap parts  46 . 
     In other words, when projected vertically, all the bosses  47  are arranged to fall within an imaginary rectangular area defined by the two support-frame-side hooks  45  and the two recessed snap parts  46  as four corners of a rectangle. Alternatively, if more than three support-frame-side hooks  45  and more than three recessed snap parts  46  are provided, the imaginary rectangular area is defined by two outermost support-frame-side hooks  45  and two outermost recessed snap parts  46  as four outermost corners of a rectangle. 
     (4) Detailed Description of the Snap Hook Part 
     As shown in  FIG. 5 , the snap hook part  48  is generally L-shaped in a side view. Specifically, the snap hook part  48  includes a leg part  58  that extends downward from the bottom surface of the support frame  11  near the left-rear corner thereof, and a pawl part  59  that extends forward from a bottom edge of the leg part  58 . 
     The leg part  58  has a flat plate shape and is generally rectangular in a plan view. The leg part  58  is so configured as to be resiliently deformable in the front-rear direction. A second through-hole  60  is formed in a bottom end portion of the leg part  58 , penetrating the leg part  58  in the front-rear direction. 
     In a side view, the pawl part  59  is generally shaped like a right triangle, with one vertex pointing forward and its top side aligned in the front-rear direction. 
     (5) Detailed Description of the Grip Parts 
     As shown in  FIG. 4 , the grip parts  49  are provided one on each of the left and right edges of the support frame  11  and are positioned in the front-rear center thereof. The grip parts  49  are generally rectangular in a bottom view and are recessed upward relative to the bottom surface of the support frame  11  to allow the user to grip the support frame  11 . 
     4. Assembling the Scanning Unit to the Main Casing 
     Next, how the scanning unit  3  is assembled to the main casing  2  will be described with reference to FIGS.  2  and  5 - 8 . In the following description of this assembly, detailed descriptions will be provided for the tray-forming member  13  of the main casing  2  and the support frame  11  of the scanning unit  3 . 
     To assemble the scanning unit  3  onto the main casing  2 , first the operator positions the scanning unit  3  over the main casing  2 , as shown in  FIG. 2 . Next, the operator tilts the right side of the support frame  11  downward, as shown in  FIG. 5 , and engages the support-frame-side hooks  45  with the body-side hooks  18  such that the hook-shaped portions  50  of the support-frame-side hooks  45  are fitted into the hook-shaped portions  20  of the body-side hooks  18 , as shown in  FIG. 8 . 
     Next, the operator pivots the support frame  11  about its right edge so that the left side moves downward. As the support frame  11  pivots, the two bosses  47  disposed on the right side of the support frame  11  are fitted into the corresponding first boss holes  19 . At this point, the support frame  11  is sloped relative to the tray-forming member  13  so that the bosses  47  engage in the first boss holes  19  in a slanted state. Since the first boss holes  19  are elongated in the left-right direction, the first boss holes  19  can smoothly receive the bosses  47  in their slanted state. 
     As the support frame  11  is pivoted further about its right edge, the two bosses  47  disposed on the left side of the support frame  11  engage in the two second boss holes  25 . Since the support frame  11  is substantially parallel to the tray-forming member  13  at this time, the bosses  47  engage in the second boss holes  25  in a state substantially vertically thereto. 
     As the support frame  11  pivots further about its right edge, the recessed snap parts  46  contact the snapping protrusions  24  from leftward thereof, and the pawl part  59  of the snap hook part  48  contacts the snap-receiving part  27  from rearward thereof. As a result, the recessed snap parts  46  deform resiliently leftward by a distance equivalent to a protruding length of the snapping protrusions  24 . As the support frame  11  continues to pivot, the first through-holes  54  in the recessed snap parts  46  become aligned with the snapping protrusions  24  in the left-right direction. At this time, the recessed snap parts  46  are allowed to return to their original state, with the snapping protrusions  24  received in the first through-holes  54  of the recessed snap parts  46 . 
     At the same time, the snap hook part  48  resiliently deforms rearward, on its leg part  58 , by a distance equivalent to a protruding length of the pawl part  59 . As the support frame  11  continues to pivot, the leg part  58  of the snap hook part  48  returns to its original state, with the pawl part  59  of the snap hook part  48  positioned beneath the snap-receiving part  27 . Through this operation, the recessed snap parts  46  are engaged with the corresponding snapping protrusions  24  and the snap hook part  48  is engaged with the snap-receiving part  27 , as illustrated in  FIGS. 7 and 8 . 
     The operator completes assembly of the scanning unit  3  on the main casing  2  by threading a screw (not shown) into the screw hole  38  of the snap-receiving part  27  via the second through-hole  60  and by threading screws (not shown) into the screw holes  26  of the snapping protrusions  24 . At this time, the grip parts  49  are positioned opposite the recessed parts  14  vertically, as shown in  FIG. 1 . 
     5. Assembling the Communication Circuit Board in the Retaining Part 
     Next, mounting of the communication circuit board  28  in the retaining part  29  of the tray-forming member  13  will be described. The communication circuit board  28  is a wireless LAN circuit board that functions to communicate with an external personal computer. 
     As shown in  FIG. 9 , the communication circuit board  28  has a substantially rectangular flat plate shape. To mount the communication circuit board  28  in the retaining part  29 , the operator places the bottom edge of the communication circuit board  28  in contact with the bottom wall of the retaining part  29 , as shown in  FIG. 9A , so that the bottom edge of the communication circuit board  28  is engaged in the first engaging portions  33  provided on the bottom wall of the retaining part  29 . With the communication circuit board  28  engaged in the first engaging portions  33 , the operator then presses the communication circuit board  28  toward the left wall  16  so that the communication circuit board  28  is engaged with the restricting wall  34  and second engaging part  35 , as shown in  FIG. 9B . This completes the process of assembling the communication circuit board  28  in the retaining part  29 . 
     6. Operations and Technical Advantages 
     (1) In the printer  1  of the first embodiment described above, the right end of the main casing  2  is fixed to the right end of the support frame  11  by engaging the body-side hooks  18  with the support-frame-side hooks  45 , as shown in  FIG. 8 . Further, the left end of the main casing  2  is fixed to the left end of the support frame  11  by engaging the snapping protrusions  24  in the recessed snap parts  46 , as shown in  FIG. 5 . 
     Therefore, if the user grips the printer  1  by the grip parts  49  provided in the support frame  11 , this configuration can minimize shifting or rattling between the main casing  2  and support frame  11 , at least in the left-right direction. In this way, this structure of the first embodiment can suppress the amount of load applied to engaging portions (the support-frame-side hooks  45  and recessed snap parts  46 ) and engaged portions (the body-side hooks  18  and snapping protrusions  24 ) caused by shifting or rattling between the main casing  2  and support frame  11 . 
     (2) As shown in  FIGS. 6 and 7 , the support frame  11  of the present embodiment is provided with the support-frame-side hooks  45  and recessed snap parts  46 , and the tray-forming member  13  is provided with the body-side hooks  18  and snapping protrusions  24 . 
     Hence, through a simple construction, it is possible to engage the body-side hooks  18  with the support-frame-side hook  45  and the snapping protrusions  24  with the recessed snap parts  46 , making it possible to assemble the support frame  11  to the main casing  2  through a simple construction. 
     (3) As shown in  FIGS. 3 and 4 , the support-frame-side hooks  45  on the support frame  11  include the reinforcing portions  51 , and the body-side hooks  18  on the main casing  2  include the reinforcing portions  21 . 
     With this construction, when the printer  1  is lifted upward by the grip parts  49 , the reinforcing portions  51  can minimize the amount that the extended parts  53  on the support frame  11  deform toward the main casing  2 , while the reinforcing portions  21  can minimize the amount that the extended parts  23  on the main casing  2  deform toward the support frame  11 . Accordingly, this construction ensures that the main casing  2  follows movement of the support frame  11  when the user lifts the printer  1  by gripping the support frame  11 . 
     (4) As shown in  FIGS. 3 and 4 , the support frame  11  is provided with the bosses  47 , while the main casing  2  is provided with the boss holes  19  and  25 . This configuration can further reduce shifting or rattling between the main casing  2  and support frame  11  through the engagement between the bosses  47  and the boss holes  19  and  25 . 
     (5) As shown in  FIG. 4 , two of the four bosses  47  are formed on the left side of the support frame  11 . These bosses  47  can better suppress shifting or rattling between the main casing  2  and support frame  11  near the snapping protrusions  24  and recessed snap parts  46 . 
     Accordingly, this configuration reduces the amount of load applied to the snapping protrusions  24  and recessed snap parts  46  due to shifting and rattling between the support frame  11  and main casing  2 , preventing damage to the snapping protrusions  24  and recessed snap parts  46 . 
     (6) The printer  1  of the first embodiment can prevent shifting or rattling between the main casing  2  and the support frame  11  with the body-side hooks  18  and the recessed snap parts  46  disposed on outer sides of the printer  1  in the left-right direction, while the bosses  47  provided on inner sides of the printer  1  in the left-right direction (inward of the body-side hooks  18  and recessed snap parts  46 ) can partially absorb the load applied to the body-side hooks  18  and recessed snap parts  46  (load in left-right direction). 
     Thus, this construction can suppress shifting or rattling between the main casing  2  and support frame  11  while preventing damage to the body-side hooks  18  and recessed snap parts  46 . 
     (7) The printer  1  of the first embodiment is further provided with the snap hook part  48  disposed on the rear side of the support frame  11  and the snap-receiving part  27  disposed on the rear side of the main casing  2 . 
     This structure can also suppress shifting or rattling between the main casing  2  and support frame  11  in the front-rear direction. 
     (8) As shown in  FIGS. 1 and 2 , the main casing  2  is provided with the pair of side walls  12  disposed on the left and right sides of the image-forming unit  5 , respectively, and the tray-forming member  13  linking the side walls  12 . By linking the side walls  12  with the tray-forming member  13  in this way, this configuration improves rigidity of the main casing  2 . 
     (9) As shown in  FIG. 9 , the printer  1  includes the retaining part  29  for retaining the communication circuit board  28 . Attachment of the communication circuit board  28  to the tray-forming member  13  can be easily done. Also, such location of the communication circuit board  28  between the image-forming unit  5  and image-reading unit  10  is efficient in terms of installation of electrical wirings. 
     7. Second Embodiment 
     A scanning unit  203  according to a second embodiment of the present invention will be described next with reference to  FIG. 10 , wherein like parts and components are designated with the same reference numerals as those of the first embodiment to avoid duplicating description. 
     In the first embodiment described above, the support frame  11  is formed in a size substantially the same as that of the main casing  2  in a plan view, and the grip parts  49  are formed in the left and right edges of the support frame  11 . The grip parts  49  are positioned so as to confront the recessed parts  14  formed in the side walls  12  when the scanning unit  3  is assembled on the main casing  2  (see  FIG. 1 ). 
     A support frame  211  according to the second embodiment is provided with a right protruding part  69  that protrudes rightward from a right edge of the support frame  211 , and a left protruding part  70  that protrudes leftward from a left edge of the support frame  211 . Grip parts  249  are provided on bottom surfaces of the right protruding part  69  and left protruding part  70 , extending in the front-rear direction along these bottom surfaces. 
     The support frame  211  also includes two fitting parts  71  provided on its bottom surface. The two fitting parts  71  are formed one on each of the left and right sides of the support frame  211  at positions for fitting into the recessed parts  14  formed in the corresponding side walls  12  when the scanning unit  203  is assembled on the main casing  2 . The fitting parts  71  are generally rectangular in a side view and protrude downward from the bottom surface of the support frame  211 . The fitting parts  71  have a thick plate shape with a substantial thickness in the left-right direction. 
     When the scanning unit  203  is assembled on the main casing  2 , the fitting parts  71  are fitted inside the recessed parts  14 , with the right protruding part  69  and left protruding part  70  protruding outward (rightward and leftward respectively) from the main casing  2  in right-left direction. 
     With this construction of the support frame  211 , the user can lift up the printer  1  stably with regard to the left-right direction by gripping the grip parts  249  of the right protruding part  69  and left protruding part  70 . 
     Further, the construction of the second embodiment can also achieve technical advantages the same as those of the first embodiment. 
     While the invention has been described in detail with reference to the embodiments thereof, it would be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention. 
     For example, in the depicted embodiments, the support-frame-side hooks  45  and the body-side hooks  18  (claimed first engaging portion and first engaged portion respectively) are formed on the right side of the printer  1 , while the recessed snap parts  46  and the snapping protrusions  24  (claimed second engaging portion and second engaged portion) are formed on the left side of the printer  1 . However, these engaging portions and engaged portions may not necessarily be provided at the left/right sides of the printer  1 , but may be provided at the front/rear sides of the printer  1 . That is, the first engaging portion and the first engaged portion (the support-frame-side hooks  45  and the body-side hooks  18 ) may be formed at either one of the front side and the rear side of the printer  1 , while the second engaging portion and the second engaged portion (the recessed snap parts  46  and the snapping protrusions  24 ) may be formed on remaining one side of the printer  1  (either the front side or the rear side). If this is the case, claimed third engaging portion and third engaged portion (the snap hook part  48  and the snap-receiving part  27 ) should be provided either at the right side or at the left side of the printer  1 . With this construction as well, the printer  1  can suppress shifting and rattling between the support frame  11  and the main casing  2  in the front-rear direction as well as in the left-right direction.