Abstract:
In a recording apparatus, a first frame holds an accommodating portion and a conveying mechanism. A second frame holds a recording head and a first tank. The second frame is connected to the first frame so as to be movable relative to the first frame. The second frame is configured to move between a first position and a second position by moving relative to the first frame. The recording head is located adjacent to the first frame when the second frame is in the first position. The recording head is further apart from the first frame when the second frame is in the second position than when the second frame is in the first position. The recording head opposes the supporting portion when the second frame is at the first position.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority from Japanese Patent Application No. 2011-238788 filed Oct. 31, 2011. The entire content of this priority application is incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    The present invention relates to a recording apparatus for recording images on a recording medium by ejecting liquid from ejection openings. 
       BACKGROUND 
       [0003]    There has been proposed an ink jet recording apparatus that includes: a sheet supplying unit; a registration adjusting unit; a recording unit; and a tray for accommodating sheets having images recorded thereon. The recording unit includes a first casing accommodating recording heads and a second casing accommodating a support part supporting a recording medium. 
       SUMMARY 
       [0004]    In the ink jet recording apparatus described above, all the units from the sheet supplying unit to the tray are arranged in line. So, the planar size of the entire ink jet recording apparatus is large. 
         [0005]    In view of the foregoing, it is an object of the invention to provide a recording apparatus that is small in size but that can convey a recording medium accurately. 
         [0006]    In order to attain the above and other objects, the invention provides a recording apparatus including: a recording head; a first tank; an accommodating portion; a first discharging portion; a conveying mechanism; a first casing; and a second casing. The recording head has an ejection surface formed with ejection openings, through which the recording head ejects liquid, the recording head being configured to record an image on a recording medium by ejecting liquid from the ejection openings. The first tank is configured to store ink to be supplied to the recording head. The accommodating portion is configured to accommodate the recording medium, on which an image is to be recorded by the recording head. The recording medium, on which an image has been recorded by the recording head, is discharged onto the first discharging portion. The conveying mechanism includes a conveying path, the conveying path extending from the accommodating portion through a recording position to the first discharging portion, the conveying mechanism being configured to convey the recording medium along the conveying path, the recording position being defined on a supporting portion that is configured to confront the recording head and support the recording medium. The first casing holds the accommodating portion and the conveying mechanism. The second casing holds the recording head, the first discharging portion and the first tank. The second casing is connected to the first casing so as to be rotatable relative to the first casing about a prescribed axis, the second casing being configured to move between a first position and a second position by rotating relative to the first casing, the recording head being located adjacent to the first casing when the second casing is in the first position, the recording head being further apart from the first casing when the second casing is in the second position than when the second casing is in the first position. The recording head opposes the supporting portion when the second casing is at the first position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    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: 
           [0008]      FIG. 1  is a perspective view showing an external appearance of an ink-jet printer according to an embodiment of the present invention, wherein an upper casing of the printer is positioned in a proximity position; 
           [0009]      FIG. 2  is a perspective view showing the external appearance of the ink-jet printer of  FIG. 1 , wherein the upper casing is positioned in a separation position; 
           [0010]      FIG. 3  is a side view schematically showing the internal configuration of the printer; 
           [0011]      FIG. 4  is a schematic plan view schematically showing the internal configuration of the printer; 
           [0012]      FIGS. 5A and 5B  show how the upper casing is rotated relative to the lower casing from the proximity position to the separation position, wherein  FIG. 5A  shows the state where the upper casing is in the proximity position and  FIG. 5B  shows the state where the upper casing is in the separation position; 
           [0013]      FIG. 6  is a schematic side view schematically showing the internal configuration of the printer when a discharge tray is added to the printer; 
           [0014]      FIG. 7  is a perspective view of a guide member; and 
           [0015]      FIGS. 8A and 8B  show how the guide member operates, wherein  FIG. 8A  shows the state where the upper casing is in the proximity position and a supporting member is in a lower-limit position, and  FIG. 8B  shows the state where the upper casing is in the separation position and the supporting member is in the lower-limit position. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    An ink-jet printer according to one embodiment of the present invention will be described with reference to the accompanying drawings. 
         [0017]    First will be described the overall configuration of the ink-jet printer  1  with reference to  FIGS. 1 to 4 . The terms “upward”, “downward”, “upper”, “lower”, “above”, “below”, “beneath”, “right”, “left”, “front”, “rear” and the like will be used throughout the description assuming that the ink-jet printer  1  is disposed in an orientation in which it is intended to be used. In use, the ink-jet printer  1  is disposed as shown in  FIG. 1 , in which a main scanning direction of the ink-jet printer  1  is parallel with the left-right direction, and a sub-scanning direction (or a direction perpendicular to the main scanning direction and the vertical direction) is parallel with the front-rear direction. The directions are defined also for cartridges  4  (which will be described later) so that the directions of the cartridges  4  are defined for when the cartridges  4  are mounted in the ink-jet printer  1 . 
         [0018]    The printer  1  includes an upper casing  1   a  and a lower casing  1   b . The upper casing  1   a  and the lower casing  1   b  both are in the shape of a rectangular parallelepiped and substantially equal in size. A lower surface of the upper casing  1   a  is opened. An upper surface of the lower casing  1   b  is opened. The upper casing  1   a  is stacked on the lower casing  1   b,  thereby sealing the opening surfaces of both. As a result, a space inside the printer  1  is defined (See  FIG. 3 ). 
         [0019]    A sheet discharging portion  31  is provided on a top panel of the upper casing  1   a.  In the internal space of the printer  1 , as indicated by bold broken arrows in  FIG. 3 , a conveying path is formed to convey a paper sheet P from a first sheet supply portion  1   c  and a second sheet supply portion  1   d  to the sheet discharging portion  31 . 
         [0020]    The upper casing  1   a  includes an upper-casing frame  1   a   1  (See  FIG. 4 ) and an upper-casing decorative panel  1   a   2 . The upper-casing decorative panel  1   a   2  is fixed to the upper-casing frame  1   a   1  on the outside of the upper-casing frame  1   a   1 . The upper-casing frame  1   a   1  includes: a pair of upper-casing rigid frames that oppose with each other in the main scanning direction and that are high in strength; and an upper-casing connection frame (not shown) that connects the pair of upper-casing rigid frames with each other. 
         [0021]    The lower casing  1   b  includes a lower-casing frame  1   b   1  (See  FIGS. 2-4 ) and a lower-casing decorative panel  1   b   2 . The lower-casing decorative panel  1   b   2  is fixed to the lower-casing frame  1   b   1  on the outside of the lower-casing frame  1   b   1 . The lower-casing frame  1   b   1  includes: a pair of lower-casing rigid frames  1   b   7  that oppose with each other in the main scanning direction and that are high in strength; and a lower-casing connection frame  1   b   8  that connects the pair of lower-casing rigid frames  1   b   7  with each other. 
         [0022]    The lower-casing frame  1   b   1  supports a conveying mechanism  40  (described later), and is the most rigid of all the frames. As shown in  FIGS. 2 and 5A , the lower-casing frame  1   b   1  has a reverse L-shape in a side view when seen in the main scanning direction. More specifically, each of the lower-casing rigid frames  1   b   7  is a plate of a reverse L shape, and extends both in the front-rear direction and in the vertical direction. As shown in  FIG. 5A , the reverse L shape has a bottom side part  1   b   9  that extends in the front-rear direction and a protruding part  1   b   3  that protrudes upwardly from a rear side end of the bottom side part. While the bottom side part  1   b   9  is positioned at the lower casing side, the protruding part  1   b   3  protrudes into the upper casing side  1   a . The bottom side part in the lower-casing rigid frame  1   b   7  will be referred to as a “lower-frame main portion  1   b   9 ”. The upwardly protruding part in the lower-casing rigid frame  1   b   7  will be referred to as a “lower-frame projecting portion  1   b   3 ”. Thus, the pair of lower-casing rigid frames  1   b   7  have a pair of lower-frame main portions  1   b   9  and a pair of lower-frame projecting portions  1   b   3 . The lower-frame projecting portions  1   b   3  project upwardly from the rear side ends of the lower-frame main portions  1   b   9 . A guide member  92  (described later) connects the pair of lower-frame projecting portions  1   b   3  with each other. By being connected by the guide member  92 , the pair of lower-frame projecting portions  1   b   3  constitute a highly rigid frame portion. It is noted that in  FIG. 4 , only the lower-frame projecting portions  1   b   3  and the lower-casing connection frame  1   b   8  are shown, but the remaining part of the lower-casing frame  1   b   1  is not shown, in order to facilitate understanding the internal configuration of the printer  1 . 
         [0023]    As shown in  FIGS. 3 and 5A , the upper casing  1   a  is connected to the lower casing  1   b  through shafts (pivot shafts)  1   x.  The shafts  1 X are disposed in the upper casing  1   a  at such a position that is on a rear side end portion in the front-rear direction and substantially at a center in the vertical direction. The shafts  1   x  extend in the main scanning direction. The upper casing  1   a  is rotatable about an axis  1   z  of the shaft  1   x  relative to the lower casing  1   b.  The upper casing  1   a  can rotate between a proximity position shown in  FIGS. 1 ,  3 , and  5 A, in which the upper casing  1   a  is adjacent to the lower casing  1   b,  and a separation position shown in  FIGS. 2 and 5B , in which the upper casing  1   a  is farther away from the lower casing  1   b  than when the upper casing  1   a  is in the proximity position. When the upper casing  1   a  is in the proximity position, the liquid ejection surfaces  10   a  of the heads  10  extend along the horizontal plane and oppose the upper surfaces of the platens  44  and  45  (to be described later) in the vertical direction. 
         [0024]    When the upper casing  1   a  is in the separation position, part of the paper sheet conveying path is exposed to outside, thereby securing a working space for a user on the paper sheet conveying path formed inside the upper and lower casings  1   a  and  1   b.  Using the working space, the user can manually carry out a jam operation (or an operation of removing a paper sheet P jammed on the conveying path). 
         [0025]    As shown in  FIG. 4 , the shafts  1   x  project outwardly in the main scanning direction from outer-side surfaces of the pair of lower-frame projecting portions  1   b   3  in the main scanning direction. Thus, the shafts  1   x  are provided on the highly rigid projecting portions  1   b   3 . Each shaft  1   x  extends in the main scanning direction, and the axis  1   z  of the shaft  1   x  also extends in the main scanning direction. 
         [0026]    The upper-casing frame  1   a   1  is provided with a pair of bearings  1   y . The bearings  1   y  support the shafts  1   x  so that the shafts  1   x  can rotate relative to the bearings  1   y.  The shafts  1   x  and the bearings  1   y  connect the upper casing  1   a  and the lower casing  1   b  together in such a way that the upper casing  1   a  and the lower casing  1   b  are rotatable relative to each other. 
         [0027]    Springs (not shown) are provided on the shafts  1   x  to urge the upper casing  1   a  in a direction to rotate the upper casing  1   a  from the proximity position toward the separation position, that is, to open the upper casing  1   a.  According to the present embodiment, the upper casing  1   a  can open until the upper casing  1   a  reaches a predetermined angle relative to the horizontal plane. That is, the upper casing  1   a  can open until the angle θ formed between the upper casing  1   a  and the lower casing  1   b  becomes the predetermined angle. The predetermined angle is such an amount that allows a user to put his/her hand into between the upper casing  1   a  and the lower casing  1   b  to carry out a jam operation. According to the present embodiment, the predetermined angle is 29 degrees. 
         [0028]    As shown in  FIG. 2 , a lock mechanism  65  is provided on a front surface of the upper casing  1   a.  The lock mechanism  65  restricts the upper casing  1   a  from rotating when the upper casing  1   a  is located at the proximity position. A door  22  is provided on the front surfaces of the upper and lower casings  1   a  and  1   b  to partially cover the front surfaces and able to be opened and closed. When the door  22  is opened, the lock mechanism  65  is exposed. When the lock by the lock mechanism  65  is released, the upper casing la becomes able to rotate relative to the lower casing  1   b.  After the upper casing  1   a  goes back to the proximity position, the lock mechanism  65  automatically restricts the rotation of the upper casing  1   a.  Incidentally, the door  22  also serves as a manual feed tray  22  in the second sheet supply portion  1   d  as described later. 
         [0029]    Next will be described, with reference to  FIGS. 3 and 4 , respective components disposed in the internal space of the printer  1 . 
         [0030]    There are disposed in the internal space of the printer  1 : a control unit  100 ; the conveying mechanism  40 ; a head unit  9 ; two sub-tanks  80 ; two cartridges  4 ; two cartridge mounting portions  70 ; the first sheet supply portion  1   c;  and the second sheet supply portion  1   d.  The control unit  100  controls each portion in the printer  1 . The conveying mechanism  40  defines the conveying path of a paper sheet P. The head unit  9  includes the two heads  10  for ejecting liquid. The two sub-tanks  80  correspond to the two heads  10 . The two cartridges  4  correspond to the two sub-tanks  80 . The two cartridges  4  are detachably mountable in the two cartridge mounting portions  70 , respectively. The upper casing  1   a  retain the control unit  100 , the head unit  9 , the two sub-tanks  80 , and the two cartridges  4 . The lower casing  1   b  retain the conveying mechanism  40  and the first and second sheet supply portions  1   c  and  1   d.    
         [0031]    The control unit  100  controls: a preparation operation pertaining to recording; an operation of supplying, conveying, and discharging paper sheets P; and a liquid ejection operation and any other operations to record images on the paper sheets P based on a recording command supplied from an external device (a personal computer connected to the printer  1 , for example). The liquid ejection operation is performed in synchronization with the operation of conveying the paper sheets P. 
         [0032]    The control unit  100  includes a CPU (Central Processing Unit) that works as an arithmetic processing device. The control unit  100  also includes a ROM (Read Only Memory), a RAM (Random Access Memory: including a nonvolatile RAM), an I/F (Interface), and an I/O (Input/Output Port). The ROM stores therein programs executed by the CPU, and various kinds of fixed data. The RAM temporarily stores therein data such as image data that is used when programs are executed. The CPU is provided with an ASIC, which performs a process of rewriting and/or rearranging image data, such as a signal processing and an image processing. The I/F transmits data to an external device, and receives data from the external device. The I/O inputs and outputs detection signals of various sensors. 
         [0033]    The conveying path defined by the conveying mechanism  40  includes: paths R 1 , R 2 , and R 3 ; a path R 4 ; and a path R 5 . The paths R 1 , R 2 , and R 3  are used for normal conveyance. The path R 4  is for connecting the second sheet supply portion  1   d  to the path R 1 . The path R 5  is connected to a sheet discharge tray  200  when the sheet discharge tray  200  (described later; see  FIG. 6 ) is added to the printer  1 . The conveying mechanism  40  includes a conveying motor (not shown), and components (described later) defining the paths R 1  and R 5 . The conveying mechanism  40  is retained by the lower-casing frame  1   b   1 . Especially, the paths R 3  and R 5  are retained by the pair of lower-frame projecting portions  1   b   3 . 
         [0034]    The path R 1  extends from the first sheet supply portion  1   c  to recording positions, where a sheet of paper P faces the liquid ejection surfaces  10   a,  and is curved in a U-shape when seen from the main scanning direction. The path R 1  is defined by guides  41  to  43 , and pairs of rollers  51  to  53 . 
         [0035]    The path R 2  runs through the recording positions of the two heads  10 , or between the heads  10  and platens  44  and  45 . The path R 2  is defined by the platens  44  and  45  and a pair of rollers  54 . The platens  44  and  45  face the liquid ejection surfaces  10   a  of the heads  10 . 
         [0036]    The path R 3  extends from the recording positions to the sheet discharging portion  31  and is curved in a U-shape when seen from the main scanning direction. The path R 3  is defined by guides  46  and  47 , and pairs of rollers  55  to  57 . The path R 3  is positioned at a level higher than the recording positions in terms of the vertical direction. In other words, the path R 3  is on the same side as the liquid ejection surfaces  10   a  relative to the recording positions. The path R 3  is curved in a direction opposite to the path R 1 . That is, as shown in  FIG. 3 , while the path R 1  is so curved as to bulge frontward (or is curved in a U-shape with the bottom of the U-shape positioned on the front side), the path R 3  is so curved as to bulge rearward (or is curved in a U-shape with the bottom of the U-shape positioned on the rear side). As a result, the paths R 1  to R 3  overall are in a reverse S shape. 
         [0037]    The path R 4  extends from the second sheet supply portion  1   d  to a middle portion of the path R 1 , and is defined by a branching guide  43   a  that branches from the guide  43 . 
         [0038]    The path R 5  extends vertically upward from a middle portion of the path R 3  and is defined by a branching guide  47   a  that branches from the guide  47 . 
         [0039]    The pairs of rollers  51  to  57  each include a driving roller and a following roller: the driving roller is connected to the conveying motor, and the following roller rotates as the driving roller rotates. 
         [0040]    Incidentally, in a portion where the path R 3  is connected to the path R 5 , a switching mechanism  69  is provided to switch the conveying paths of the paper sheet P. The switching mechanism  69  includes a swing member  69   a  and a driving unit (not shown). The swing member  69   a  swings between the first position (or the position shown in  FIG. 3 ) and the second position (or the position shown in  FIG. 6 ) where the paths R 3  and R 5  communicate with each other. The driving unit drives the swing member  69   a.  The driving unit of the switching mechanism  69  is controlled by the control unit  100 . In order to discharge a paper sheet P onto the sheet discharging portion  31 , the swing member  69   a  is located at the first position. In order to discharge a paper sheet P onto the sheet discharge tray  200 , the swing member  69   a  is located at the second position. 
         [0041]    Thus, the lower-casing frame  1   b   1  retains: the guides  41  to  43 , pairs of rollers  51  to  53 , platens  44  and  45 , pair of rollers  54 , guides  46  and  47 , pairs of rollers  55  to  57 , the branching guide  43   a,  branching guide  47   a,  and switching mechanism  69 . 
         [0042]    The head unit  9  includes the two heads  10  and a carriage  3  that supports the heads  10 . The two heads  10  include a pre-coating head and an ink-jet head which are arranged in this order in the sheet conveying direction from its upstream side to its downstream side. The pre-coating head is for ejecting pretreatment liquid, while the ink-jet head is for ejecting black ink. 
         [0043]    The heads  10  have the same configuration with each other. The heads  10  are of a line type, and are long in the main scanning direction. The outer shape of the heads  10  is substantially a rectangular parallelepiped. The heads  10  are fixedly mounted on the carriage  3  such that the heads  10  are separate from each other in the sub-scanning direction. The carriage  3  is supported by the upper-casing frame  1   a   1 . 
         [0044]    As shown in  FIG. 3 , the heads  10  are oriented so that the liquid ejection surfaces  10   a  are parallel to the horizontal plane and face vertically downwardly. Each liquid ejection surface  10   a  is formed with many ejection nozzles (ejection openings). Flow channels are formed inside each head  10 . Pretreatment liquid and black ink, which will be collectively referred to as “liquid,” hereinafter, are supplied from the cartridges  4  to the heads  10 , and flow through the flow channels, before reaching the ejection nozzles. The pretreatment liquid is for preventing bleeding and strike-through of ink, and for improving color development and quick-drying characteristics of ink. 
         [0045]    The sub-tanks  80  are for storing liquid supplied from the cartridges  4 . As shown in  FIGS. 2 and 4 , the sub-tanks  80  are disposed side by side with the heads  10  in terms of the main scanning direction. As shown in  FIG. 4 , in terms of the main scanning direction, the sub-tanks  80  are disposed at one edge side (left edge side) in the upper casing  1   a  with respect to the center of the upper casing  1   a.  The sub-tanks  80  are supported by the upper-casing frame  1   a   1  at a position outside the upper-casing frame  1   a   1  in the main scanning direction. The sub-tanks  80  are connected with the heads  10  via pipes  81 . The sub-tanks  80  are for supplying liquid to the heads  10 . 
         [0046]    The two cartridge mounting portions  70  are disposed adjacent to each other in the vertical direction, and are provided between the pair of upper-casing rigid frames in the upper-casing frame  1   a   1 . In terms of the vertical direction, the cartridge mounting portions  70  are disposed at a position higher than the heads  10  and the sub-tanks  80  (See  FIG. 5A ). That is, the sub-tanks  80  are placed at a position lower than the cartridge mounting portions  70  or the cartridges  4  mounted in the cartridge mounting portions  70 . As a result, liquid is supplied naturally from the cartridges  4  to the sub-tanks  80 . 
         [0047]    As shown in  FIG. 4 , in planar view, the cartridge mounting portions  70  are long and extend in the main scanning direction, similarly to the heads  10 . In terms of the main scanning direction, the cartridge mounting portions  70  are so disposed as to overlap with the heads  10  when seen in the sub-scanning direction. So, the space inside the upper casing  1   a  can be used in an effective manner even though the heads  10  are long in the main scanning direction. Accordingly, in terms of the main scanning direction, the upper casing  1   a  is small in size. 
         [0048]    Mounting ports  71  of the cartridge mounting portions  70  are formed on a front surface of the upper casing  1   a,  i.e. on a side face that is farthest away from the shafts  1   x  in terms of the sub-scanning direction. The mounting ports  71  are covered with a door  1   e.  The door  1   e  is a plate like member that is supported rotatably on the upper casing  1   a.  As indicated by two-dot chain lines in  FIG. 3 , the mounting ports  71  are exposed as the door  1   e  rotates. Through the mounting ports  71 , the cartridges  4  can be mounted to the cartridge mounting portions  70 , and can be detached from the cartridge mounting portions  70  and replaced with new ones. 
         [0049]    As shown in  FIG. 4 , each cartridge mounting portion  70  has a rearmost wall  70   a  that faces a leading edge of the cartridge  4  when a user inserts the cartridge  4  into the cartridge mounting portion  70  in the mounting direction along the front-rear direction. A step portion  72  is provided in one left edge (main-scanning direction edge) of the rearmost wall  70   a.  A hollow needle  73  is provided at the step portion  72  to extend in the front-rear direction, that is, along the mounting direction. A pipe  74  is connected to a base end of the hollow needle  73 . One pipe  74  that is connected to a hollow needle  73  of the upper cartridge mounting portion  70  is connected to the sub-tank  80  corresponding to the head (pre-coating head)  10  that is positioned on the upstream side in the sheet conveying direction. The other pipe  74  that is connected to a hollow needle  73  of the lower cartridge mounting portion  70  is connected to the sub-tank  80  corresponding to the ink-jet head  10 . The pipes  74  and the hollow needles  73  constitute liquid transferring portions for transferring liquid from the cartridges  4  to the sub-tanks  80 . The tip ends of the hollow needles  73  serve as connecting portions to connect the liquid transferring portions with the cartridges  4 . The pipes  74  and the hollow needles  73  (liquid transferring portions and the connecting portions) are disposed at the left edge side in the upper casing  1   a.  Thus, in terms of the main scanning direction, the pipes  74  and the hollow needles  73  (liquid transferring portions and the connecting portions) are disposed on the same side with the sub-tanks  80 . Therefore, the lengths of the pipes  74  can be shortened. 
         [0050]    In terms of the mounting direction (sub-scanning direction/front-rear direction), the rearmost walls  70   a  of the cartridge mounting portions  70  are disposed between the mounting ports  71  and the heads  10 . That is, in terms of the mounting direction, as shown in  FIGS. 3 and 4 , the heads  10  and the sub-tanks  80  are disposed between the shafts  1   x  and the cartridges  4  mounted in the cartridge mounting portions  70 . 
         [0051]    As shown in  FIG. 4 , the cartridges  4  are substantially in the shape of a rectangular parallelepiped, and are long in the main scanning direction. In terms of the main scanning direction, the cartridges  4  mounted in the cartridge mounting portions  70  are disposed so as to overlap with the heads  10  when seen in the sub-scanning direction. The insides of the cartridges  4  are filled with liquid. A liquid supply portion  4   a  projects from a left end portion of each cartridge  4  (one end portion of the cartridge  4  in the main scanning direction). The liquid supply portion  4   a  projects in the mounting direction along the front-rear direction. A spout made of rubber is provided on a terminal end surface of the liquid supply portion  4   a.  As the cartridge  4  is mounted into a cartridge mounting portion  70 , the liquid supply portion  4   a  is positioned in the step portion  72 , and a hollow needle  73  is inserted into the spout. As a result, liquid inside the cartridge  4  is supplied to the sub-tank  80  via the hollow needle  73  and the pipe  74 . 
         [0052]    The first sheet supply portion  1   c  is disposed below the head unit  9  and the platens  44  and  45 . The first sheet supply portion  1   c,  the head unit  9 , and the sheet discharging portion  31  partially overlap with each other along the vertical direction. 
         [0053]    That is, at least portions of the first sheet supply portion  1   c,  the heads  10 , and the sheet discharging portion  31  overlap with each other in a plan view. Accordingly, the printer  1  is small in a planar size. As a result, the installation area of the printer  1  is small. 
         [0054]    The first sheet supply portion  1   c  includes a sheet supply tray  20  and a sheet supply roller  21 . As shown in  FIG. 3 , the sheet supply tray  20  can be attached to and removed from the lower casing  1   b  in the sub-scanning direction via an insertion opening  1   b   4  that is formed in the lower casing  1   b.  In terms of the sub-scanning direction, the insertion opening  1   b   4  is formed at a side surface (i.e. the front surface of the lower casing  1   b ) that is farthest away from the shafts  1   x  in the lower casing  1   b.  The sheet supply tray  20  is in a box shape that is open upward, and is able to store paper sheets P. The sheet supply roller  21  rotates under the control of the control unit  100 , and sends a top paper sheet P among those stored in the sheet supply tray  20 . 
         [0055]    The second sheet supply portion  1   d  includes the manual feed tray  22  (door  22 ) and a sheet supply roller  23 , and is for supplying a paper sheet from a middle portion of the path R 1 . The manual feed tray  22  is a plate-like member that is supported by the lower casing  1   b  so as to be rotatable between a sealing position (or the position shown in  FIG. 1 ) where an opening lab formed on the front surfaces of the upper and lower casings  1   a  and  1   b  is covered, and an opening position (or the position shown in  FIG. 2 ) where the opening  1   ab  is opened. 
         [0056]    Usually, the second sheet supply portion  1   d  is not used. So, the manual feed tray  22  is placed at the sealing position, and is accommodated in the opening  1   ab  (which is an opening of a size that is large enough to accommodate the manual feed tray  22 ). That is, when being accommodated in the opening  1   ab , the manual feed tray  22  is part of the front surfaces of the upper and lower casings  1   a  and  1   b.  As the manual feed tray  22  is rotated and opened as shown in  FIG. 2 , the second sheet supply portion  1   d  becomes available. At this time, if paper sheets P of predetermined sizes are disposed on the manual feed tray  22  and the sheet supply roller  23  is driven to rotate under the control of the control unit  100 , the top paper sheet P, among those disposed on the manual feed tray  22 , is sent to the path R 1  via the path R 4 . 
         [0057]    Under the control of the control unit  100 , the paper sheet P sent from the first sheet supply portion  1   c  is conveyed through the paths R 1  and R 2 . The paper sheet P sent from the second sheet supply portion  1   d  is conveyed from the path R 4  to the path R 2  via the path R 1 . The paper sheet P passes just below the heads  10  (recording positions), while being supported on the upper surface of the platens  44  and  45 . At this time, under the control of the control unit  100 , the heads  10  each are driven to eject liquid from the ejection nozzles in the liquid ejection surfaces  10   a  toward the paper sheet P. As a result, an image is formed on the paper sheet P. Then, the paper sheet P is conveyed along the path R 3  before being discharged on the sheet discharging portion  31 . 
         [0058]    As shown in  FIGS. 1 and 3 , the sheet discharging portion  31  is defined by: an upper wall  91   a  of the upper casing  1   a;  a supporting member  91   b  supported by the upper wall  91   a;  and the guide member  92 . 
         [0059]    The upper wall  91   a  and the supporting member  91   b  make up a supporting surface  91   c  for supporting paper sheets P discharged from the inside of the ink-jet printer  1 . The supporting surface  91   c  is made up from the entire upper surface of the supporting member  91   b  and an area of the upper wall  91   a  that does not overlap with the supporting member  91   b  in terms of the vertical direction. The supporting surface  91   c  and part of the guide member  92  that is exposed outside of the upper casing  1   a  make up a wall surface that defines the sheet discharging portion  31 . 
         [0060]    The supporting surface  91   c  is slanted in the sub-scanning direction (front-rear direction) so as to gradually descend in a direction toward the shafts  1   x.  In other words, the supporting surface  91   c  is slanted gradually downwardly toward the rear. So, the sheet discharging portion  31  is small in planar size in terms of the sub-scanning direction (front-rear direction). 
         [0061]    As shown in  FIG. 1 , concave portions  91   d  are formed on a pair of end portions of the supporting surface  91   c  in the left-right direction (main scanning direction). Each concave portion  91   d  extends in the front-rear direction (sub-scanning direction or direction in which the supporting surface  91   c  is slanted). The concave portions  91   d  are formed across the upper wall  91   a  and the supporting member  91   b.  With the concave portions  91   d,  a paper sheet P that is discharged onto the sheet discharging portion  31  is supported by a central portion of the supporting surface  91   c  in the left-right direction (main scanning direction), with both end portions hanging downwards therefrom. A user can easily grab the left or right end portion of the paper sheet P (end portion in the main scanning direction) to take out the paper sheet P from the sheet discharging portion  31 . 
         [0062]    As shown in  FIGS. 1 ,  3 ,  4 , and  7 , the guide member  92  includes a main portion  92   a  and a pair of side portions  92   b.  The main portion  92   a  extends in the vertical and main scanning directions (vertical and left-right directions). A front surface  93  of the main portion  92   a  faces the supporting member  91   b  in terms of the sub-scanning direction (front-rear direction). The side portions  92   b  rise from left and right side edges of the front surface  93  of the main portion  92   a.  The side portions  92   b  extend in the vertical and sub-scanning directions (vertical and front-rear directions). As shown in  FIG. 3 , the main portion  92   a  is positioned at an upstream side of the upper wall  91   a  in the sheet conveying direction, with a gap  94  being formed between the main portion  92   a  and the upper wall  91   a.  That is, the rear side edge of the upper wall  91   a  confronts the main portion  92   a  via the gap  94 . As shown in  FIG. 4 , the left and right side edges of the main portion  92   a  are fixedly attached to the pair of lower-frame protruding portions  1   b   3 , thereby connecting the pair of lower-frame protruding portions  1   b   3  with each other. 
         [0063]    As shown in  FIGS. 4 and 7 , a plurality of ribs  95  are formed across substantially the entire area of the front surface  93  of the main portion  92   a.  The ribs  95  extend in the vertical direction. 
         [0064]    As shown in  FIGS. 3 and 7 , a plurality of concave portions  92   c  are formed on the front surface  93  of the main portion  92   a  at its central area in the vertical direction. The concave portions  92   c  are arranged in the left-right direction (main scanning direction), and are disposed between the adjacent ribs  95 . 
         [0065]    As shown in  FIG. 3 , the main portion  92   a  extends further downward than the rear side edge of the upper wall  91   a  that confronts the main portion  92   a  via the gap  94 . 
         [0066]    As shown in  FIG. 7 , a convex portion  93   a  projects forwardly from a lower edge of the front surface  93  of the main portion  92   a.    
         [0067]    As shown in  FIG. 3 , the path R 3  is defined by a back surface of the main portion  92   a  that is opposite to the front surface  93 . That is, the back surface of the main portion  92   a  is part of the guide  47 . 
         [0068]    As shown in  FIG. 1 , a plurality of grooves  91   e  are formed on a rear side edge of the supporting member  91   b.  The grooves  91   e  are arranged in the left-right direction (main scanning direction). The ribs  95  on the guide member  92  are disposed in the grooves  91   e.    
         [0069]    As shown in  FIG. 3 , the supporting member  91   b  is connected via a shaft  91   f  to the upper wall  91   a  substantially at the central position of the upper wall  91   a  in the front-rear direction (sub-scanning direction). A spring  99  is disposed between the upper wall  91   a  and the supporting member  91   b  to urge the supporting member  91   b  upwardly. The supporting member  91   b  can rotate between an upper-limit position ( FIG. 3 ) and a lower-limit position ( FIG. 8A ) when the upper casing  1   a  is at the proximity position. When the supporting member  91   b  is at the upper-limit position, an angle formed between the supporting member  91   b  (supporting surface  91   c ) and the front surface  93  of the main portion  92   a  of the guide member  92  is equal to a predetermined limit angle. At this time, the rear side edge of the supporting member  91   b  engages with the concave portions  92   c  of the guide member  92 , and the supporting member  91   b  is restricted from moving further upward. When the supporting member  91   b  is at the lower-limit position, the angle formed between the supporting member  91   b  and the front surface  93  is smaller than the predetermined limit angle. 
         [0070]    When the upper casing  1   a  is at the proximity position, the spring  99  urges the supporting member  91   b  in a direction toward the upper-limit position, while allowing the supporting member  91   b  to move in a direction toward the lower-limit position as the number or weight of the paper sheets P supported on the supporting member  91   b  increases. The spring  99  is compressed to the greatest extent when the supporting member  91   b  is at the lower-limit position. Therefore, the position of the top surface of a stack of paper sheets P that is discharged on the sheet discharging portion  31  is kept substantially at a constant level, making it easy for a user to collect the paper sheet P. 
         [0071]    When the upper casing  1   a  is rotated to the separation position, as shown in  FIG. 8B , the rear side edge of the supporting member  91   b  engages with the concave portions  92   c  of the guide member  92 , and the supporting member  91   b  is positioned at the lower-limit position. 
         [0072]    The spring  99  and the concave portion  92   c  constitute a movement mechanism for moving the supporting member  91   b.  When the upper casing  1   a  is rotated to the separation position, the movement mechanism moves the supporting member  91   b  to the lower-limit position. Therefore, the supporting member  91   b  does not block the rotation of the upper casing  1   a.  Incidentally, when the upper casing  1   a  is rotated to the separation position in the situation where the supporting member  91   b  is placed at the lower-limit position due to the weight of the paper sheets P, the supporting member  91   b  is brought into the state shown in  FIG. 8B  without engaging with the concave portions  92   c.    
         [0073]    According to the present embodiment, the sheet discharging portion  31  is made up from the supporting surface  91   c  and part of the front surface  93  of the guide member  92  that is exposed outside the upper casing  1   a.  The supporting surface  91   c  is in confrontation with the front surface  93 . The supporting surface  91   c  is slanted gradually downwardly toward the front surface  93 . So, the sheet discharging portion  31  is small in planar size. 
         [0074]    When the upper casing  1   a  is rotated to the separation position, paper sheets P on the sheet discharging portion  31  are unlikely to be caught between the guide member  92  and the supporting surface  91   c.  This is because the ribs  95  on the guide member  92  decrease the contact area (contact resistance) between the paper sheets P and the guide member  92 . When the upper casing  1   a  is rotated to the separation position with paper sheets P existing on the sheet discharging portion  31 , the trailing edges of the paper sheets P in the sheet conveying direction come in contact with the ribs  95  on the guide member  92 , and smoothly slide along the ribs  95 . So, the paper sheets P are not caught between the supporting surface  91   c  and the guide member  92 . 
         [0075]    The supporting surface  91   c  is supported by the upper casing  1   a,  while the guide member  92  is supported by the lower casing  1   b.  As the upper casing  1   a  is rotated from the proximity position to the separation position, the supporting member  91   b  moves relative to the guide member  92 . Therefore, the rotation of the upper casing  1   a  is not blocked. Because the gap  94  exists between the upper wall  91   a  and the guide member  92 , the upper wall  91   a  does not come in contact with the guide member  92 . 
         [0076]    Next will be described with reference to  FIGS. 5A and 5B , how the ink-jet printer  1  operates when the upper casing  1   a  is rotated from the proximity position to the separation position. 
         [0077]    According to the embodiment, as shown in  FIGS. 5A and 5B , when the upper casing  1   a  is rotated to the separation position, the heads  10  move along a rotation trajectory M 1  indicated by a two-dot chain line in  FIG. 5B . That is, the heads  10  move in a direction in which the heads  10  move away from the shafts  1   x  in terms of the front-rear direction (sub-scanning direction). In other words, the heads  10  move forwardly in terms of the front-rear direction. This is because the shafts  1   x  (axis  1   z ) are disposed at a position higher than the liquid ejection surfaces  10   a  in terms of the vertical direction. 
         [0078]    Now assume that the shafts  1   x  were at a position lower than the liquid ejection surfaces  10   a  as indicated by a reference numeral ( 1   x ′) in  FIG. 5B  in terms of the vertical direction. In such a case, when the upper casing  1   a  is rotated to the separation position, the heads  10  will move along a rotation trajectory M 2  also indicated by a two-dot chain line in  FIG. 5B . That is, the heads  10  move in a direction in which the heads  10  approach the shafts  1   x  in terms of the sub-scanning direction. In other words, the heads  10  move rearwardly in terms of the front-rear direction. 
         [0079]    According to the present embodiment, the shafts  1   x  are located at a level higher than the liquid ejection surfaces  10   a  in the vertical direction. So, when the upper casing  1   a  is rotated to the separation position, the heads  10  move toward the front end of the ink-jet printer  1  where the upper casing  1   a  departs from the lower casing. A user accesses the front surface of the printer  1  when rotating the upper casing  1   a  to the separation position and carrying out the jam operation and the maintenance of the heads. Therefore, the user can easily carry out the maintenance of the heads  10 . 
         [0080]    Furthermore, the amount of the rotation angle by which the upper casing  1   a  has to be rotated from the proximity position to the separation position is smaller when the shafts  1   x  are positioned at a level higher than the liquid ejection surfaces  10   a  in the vertical direction than when the shafts  1   x  are positioned at a level lower than the liquid ejection surfaces  10   a  or on the same level with the liquid ejection surfaces  10   a  in terms of the vertical direction. Therefore, according to the present embodiment, even if paper sheets P remain on the sheet discharging portion  31 , the paper sheets P are unlikely to fall therefrom. 
         [0081]    The heads  10  and the sub-tanks  80  are retained in the upper casing  1   a  in such a way that the heads  10  and the sub-tanks  80  are arranged side by side in terms of the main scanning direction. Accordingly, as shown in  FIG. 5B , when the upper casing  1   a  is rotated to the separation position, the water head difference between the heads  10  and the sub-tanks  80  can hardly become larger. Therefore, liquid meniscuses formed near the ejection nozzles are unlikely to be damaged. 
         [0082]    Next will be described, with reference to  FIG. 6 , the configuration of the sheet discharge tray  200 , as well as how the ink-jet printer  1  operates when the sheet discharge tray  200  is added to the printer  1 . 
         [0083]    The sheet discharge tray  200  includes a sheet discharging portion  201 , a conveying mechanism  240 , a connection terminal (not shown), and a casing  200   a . The sheet discharging portion  201  is for supporting a paper sheet P discharged from the inside of the printer  1 . The conveying mechanism  240  includes a conveying motor, and components (described below) defining a path R 6 . The connection terminal is for electrically connecting the conveying motor of the conveying mechanism  240  to the control unit  100 . The casing  200   a  supports the sheet discharging portion  201 , conveying mechanism  240 , and connection terminal (not shown). 
         [0084]    The path R 6  extends from the path R 5  to the sheet discharging portion  201 . The path R 6  is defined by guides  202  and  203  and a pair of rollers  204  and a pair of rollers  205 . 
         [0085]    A projecting portion  210  projects downward from the casing  200   a . Four L-shaped engagement portions  211  are formed on the projecting portion  210 . The lower-casing connection frame  1   b   8  is formed with two mounting through-holes  1   b   5 . By inserting the engagement portions  211  into the mounting through-holes  1   b   5 , the sheet discharge tray  200  is attached to the lower casing  1   b  of the printer  1 . At this time, the connection terminal is electrically connected to a terminal that is connected to the control unit  100  of the printer  1 . As a result, the control unit  100  becomes able to control the conveying motor of the conveying mechanism  240 . Moreover, at this time, the paths R 5  and R 6  are connected together. In this manner, the sheet discharge tray  200  is mounted on the lower casing  1   b.  Therefore, even when the upper casing  1   a  is rotated, the sheet discharge tray  200  does not tilt. Accordingly, when the upper casing  1   a  is rotated to the separation position, the paper sheets P remaining on the sheet discharging portion  201  do not fall therefrom. Moreover, compared with the case where the sheet discharge tray  200  were added to the upper casing  1   a,  the conveying paths become simple. More specifically, if the sheet discharge tray  200  were added to the upper casing  1   a,  a path connecting the sheet discharging portion  201  to the path R 5  will also rotate when the upper casing  1   a  is rotated. So, the configuration of the path connecting the sheet discharging portion  201  to the path R 5  will become extremely complicated. Contrarily, according to the embodiment, the sheet discharge tray  200  is attached directly to the lower casing  1   b,  and therefore the configuration of the connecting portion of connecting the paths R 6  and R 5  becomes simple. Moreover, compared with the case where the sheet discharge tray  200  were added to the upper casing  1   a,  it is unnecessary to increase the size of the shafts  1   x.  This is because the weight of the sheet discharge tray  200  is not applied to the shafts  1   x  according to the present embodiment. 
         [0086]    In order to discharge a paper sheet P onto the sheet discharging portion  201  under control of the control unit  100 , the conveying motor of the conveying mechanism  240  is driven, and the pairs of rollers are driven to rotate. The switching mechanism  69  is controlled so that the swing member  69   a  is placed at the second position. As a result, a paper sheet P that has been conveyed from the path R 3  to the path R 5  is discharged to the sheet discharging portion  201  via the path R 6 . 
         [0087]    Moreover, as indicated by two-dot chain lines in  FIG. 6 , when the upper casing la is rotated to the separation position, the upper front edge of the upper casing  1   a  comes in contact with the sheet discharging portion  201  of the sheet discharge tray  200 . Accordingly, the sheet discharging portion  201  serves as a stopper for restricting the upper casing  1   a  from being opened too much. As a result, the paper sheets P remaining on the sheet discharging portion  31  are unlikely to fall therefrom. 
         [0088]    As described above, in the printer  1  of the present embodiment, the conveying mechanism  40  that makes up the conveying path (paths R 1  to R 3 ) extending from the first sheet supply portion  1   c  to the sheet discharging portion  31  is retained by the lower casing  1   b.  Therefore, even when the upper casing  1   a  is rotated, the conveying path is not divided into two or more portions. Accordingly, the operation of conveying a paper sheet P is unlikely to fail. Moreover, since the conveying mechanism  40  is not retained by the upper casing  1   a,  the overall weight of the upper casing  1   a  becomes light. It is unnecessary to increase the size of the shafts lx that support the upper casing  1   a.    
         [0089]    All the components that make up a liquid supply system extending from the cartridges  4  to the heads  10  (the cartridges  4 , the cartridge mounting portions  70 , the sub-tanks  80 , the heads  10 , and the pipes  74  and  81 ) are accommodated in the upper casing  1   a.  Therefore, the liquid supply system is made compact. 
         [0090]    While the invention has been described in detail with reference to the embodiment 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. 
         [0091]    For example, as long as paper sheets P can be supplied into the space between the heads  10  and the platens  44  and  45 , the first sheet supply portion  1   c  may be placed anywhere in the lower casing  1   b.    
         [0092]    The conveying path may be formed into an S-shape. 
         [0093]    The sheet discharge tray  200  may be attached to the upper casing  1   a.    
         [0094]    The sheet discharge tray  200  may not be able to be added to the printer  1 . 
         [0095]    When the upper casing  1   a  is in the proximity position, the shafts  1   x  (axis  1   z ) may be disposed at the same level as the liquid ejection surfaces  10   a,  or at a level lower than the liquid ejection surfaces  10   a,  in terms of the vertical direction. 
         [0096]    The shaft  1   x  may not be provided on the lower-frame projecting portions  1   b   3 . 
         [0097]    The configuration of the liquid transferring portions may be of any type as long as the liquid transferring portions can transfer liquid from the cartridges  4  to the sub-tanks  80 . 
         [0098]    The sheet discharging portion  31 , the heads  10 , and the first sheet supply portion  1   c  may not overlap with each other in a direction parallel to the liquid ejection surfaces  10   a.    
         [0099]    The sheet discharging portion  31  may not be formed by the guide member  92 . 
         [0100]    No ribs  95  may be provided on the guide member  92 . 
         [0101]    The supporting surface  91   c  may be parallel to the liquid ejection surfaces  10   a.    
         [0102]    The supporting member  91   b  may not be provided. 
         [0103]    The movement mechanism for moving the supporting member  91   b  is not limited to the spring  99 . For example, the movement mechanism may be modified to be interlocked with rotation of the upper casing  1   a  so that the movement mechanism forcibly moves the supporting member  91   b  to the lower-limit position when the upper casing  1   a  is rotated to the separation position. Still in this case, when the upper casing  1   a  is at the proximity position, the mechanism moves the supporting member  91   b  toward the lower-limit position depending on the number of or the weight of paper sheets P supported on the supporting member  91   b,  as in the embodiment described above. 
         [0104]    The present invention can be applied not only to black and white printers but also to color printers. 
         [0105]    Moreover, the present invention is not limited to printers. The present invention can also be applied to facsimile machines and copy machines. 
         [0106]    The heads may eject any liquid other than ink. 
         [0107]    The recording apparatus may include only one head. 
         [0108]    A recording medium is not limited to paper sheets S, but may be any other recordable medium. 
         [0109]    The platens  44  and  45  and the pair of rollers  54  may be replaced with a belt conveying mechanism. The belt conveying mechanism is retained by the lower casing  1   b.  In the belt conveying mechanism, an endless belt is stretched between at least two rollers that are arranged in the sheet conveying direction as being separate away from one another. The upper surface of the belt moves in the sheet conveying direction as the rollers are driven to rotate. The belt therefore conveys the sheet of paper P in the sheet conveying direction, while supporting the sheet of paper P on its upper surface. Thus, the belt serves as part of the conveying mechanism  40 , and also serves as a supporting portion that confronts the heads  10  and supports the sheet of paper P.