Patent Publication Number: US-9890000-B2

Title: Sheet conveyance apparatus and image recording apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application claims priorities from Japanese Patent Application Nos. 2013-253395 and 2013-253396 both filed on Dec. 6, 2013, the disclosures of which are incorporated herein by reference in its entirety. 
     BACKGROUND 
     Field of the Invention 
     The present teaching relates to a sheet conveyance apparatus in which a sheet is fed from a sheet support unit via a conveyance path and an image recording apparatus including the sheet conveyance apparatus. 
     Description of the Related Art 
     There are known image recording apparatuses in which an image is recorded on a sheet conveyed via a conveyance path provided in a casing or housing body of the apparatus. Some of the image recording apparatuses include a sheet support unit supporting a plurality of sheets. An exemplary sheet support unit includes a support surface inclined to the direction of gravitational force, and guides a sheet obliquely downward toward the direction of gravitational force. Each sheet fed from the sheet support unit is separated from the sheets supported by the sheet support unit by use of a separation unit provided below the support surface, and then allowed to enter the conveyance path. 
     The sheets in various sizes such as A4 and A3 in accordance with Japanese Industrial Standards (JIS) can be used in the image recording apparatuses. In recent years, in addition to A4 sheet often used as office supplies in Japan, A3 sheet larger than A4 sheet is also used very often. Therefore, in order to extend the support surface of the sheet support unit, an extension tray is provided in some cases. 
     SUMMARY 
     In a structure in which a sheet is supported by a support surface of the extension tray in cooperation with the support surface of the sheet support unit, the support surface of the extension tray being a member independent from a member constituting the support surface of the sheet support unit, the extension tray may be rotatably provided in the sheet support unit. For example, in a structure in which the sheet support unit is formed of a plurality of members which are rotatable with each other, depending on the rotation state of each of the members, it may be structurally difficult to position the support surface of the extension tray and the support surface of the sheet support unit so that they are included in the same virtual plane. Or, depending on the rotation state of each of the members, it may be structurally difficult to arrange the support surface of the extension tray and the support surface of the sheet support unit so that they are at least parallel to each other in a case that there is a small difference in height between these support surfaces. Therefore, when the extension tray is rotatably provided in the sheet support unit by a simple structure without considering the possible problems about the arrangement, the support surface of the sheet support unit and the support surface of the extension tray may not be included in the same virtual plane or may not be parallel to each other. As a result, the sheet supported by the support surface of the sheet support unit and the support surface of the extension tray is bent or curved. Depending on the direction of bend or curve of the sheet, there is fear that the separation performance of the separation unit is reduced. 
     The present teaching has been made to solve the foregoing problems, an object of which is to provide a means capable of extending a support surface of a sheet support unit by the aid of a support surface of another member and capable of preventing the deterioration of sheet separation performance, or an object of which is to provide a means capable of supplementing the support surface of the sheet support unit with another member and capable of preventing the deterioration of sheet separation performance. 
     According to an aspect of the present teaching, there is provided a sheet conveyance apparatus configured to convey a sheet, including: 
     a casing including a conveyance path defined therein; 
     a sheet support unit including a first surface inclined to a placement surface on which the casing is placed and configured to support a plurality of sheets stacked thereon; 
     a separation unit arranged in the sheet support unit on a side of the placement surface and configured to abut against edges of the sheets supported by the first surface; 
     a first plate member including a second surface which is arranged in the sheet support unit on a side opposite to the separation unit and faces in the same direction as the first surface, wherein a proximal end of the second surface close to the first surface is positioned on a side nearer to the placement surface than a virtual plane including the first surface, and a distal end of the second surface far from the first surface is movable between a first position where the distal end is positioned on the virtual plane and a second position where the distal end is in a position different from the virtual plane; and 
     a feed unit configured to feed the sheet supported by the first surface and the distal end of the second surface to the conveyance path while slidably moving the sheet with respect to the separation unit. 
     Since the first surface of the sheet support unit and the distal end of the second surface of the first plate member in the first position are included in the same virtual plane, the sheet supported by the first surface and the distal end of the second surface is neither bent nor curved. Further, when the first plate member is in the first position, a third surface of a second plate member in a fourth position is parallel to the virtual plane. Thus, a surface of the sheet is not bent at a boundary between the distal end of the second surface and the third surface. 
     According to the present teaching, the first surface of the sheet support unit can be extended by the aid of the second surface of the first plate member and the third surface of the second plate member, and it is possible to prevent the deterioration of sheet separation performance of the separation unit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective external view of a multi-function peripheral  10  in which a movable unit  69  is in an upstanding state. 
         FIG. 2  is a vertical cross-sectional view of an internal structure of a printer unit  11 . 
         FIG. 3  is a perspective view of a bypass tray  70  in which the movable unit  69  is in an inclined or laid-down state and a tray cover  94  is in a sealing position. 
         FIG. 4  is a cross-sectional view taken along the line IV-IV of  FIG. 3 . 
         FIG. 5  is a perspective external view of the multi-function peripheral  10  on a back surface side in which the movable unit  69  is removed. 
         FIG. 6  is a perspective view of the bypass tray  70  in which the movable unit  69  is in the inclined state and the tray cover  94  is in an open position. 
         FIG. 7  is a cross-sectional view taken along the line VII-VII of  FIG. 6 . 
         FIG. 8  is a perspective view of the bypass tray  70  in which the movable unit  69  is in the inclined state, an extension member  89  is extended, and the tray cover  94  is in the open position. 
         FIG. 9  is a cross-sectional view taken along the line IX-IX of  FIG. 8 . 
         FIG. 10  is a perspective view of the bypass tray  70  in which the movable unit  69  is in the inclined state, the extension member  89  is extended, the tray cover  94  is in the open position, and a support member  101  is in a projecting state. 
         FIG. 11  is a cross-sectional view taken along the line XI-XI of  FIG. 10 . 
         FIG. 12  is a perspective view of the support member  101  in a refracted or housed state and an outer surface member  105 . 
         FIG. 13  is a perspective view of the support member  101  in the projecting state and the outer surface member  105 . 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     An explanation will be made below about a multi-function peripheral  10  according to an embodiment of the present teaching. It goes without saying that the embodiment explained below is merely an example of the present teaching, and the embodiment can be appropriately changed within a range without changing the gist or essential characteristics of the present teaching. Further, in the following explanation, the up-down direction  7  of the multi-function peripheral  10  is defined on the basis of the state (state depicted in  FIG. 1 ) in which the multi-function peripheral  10  (an exemplary image recording apparatus of the present teaching) is placed to be usable, the front-rear direction  8  of the multi-function peripheral  10  is defined assuming that the side, on which an opening  13  is provided, is the near side (front side), and the left-right direction  9  of the multi-function peripheral  10  is defined while viewing the multi-function peripheral  10  from the near side (front side). 
     &lt;Entire Structure of Multi-Function Peripheral  10 &gt; 
     As depicted in  FIG. 1 , the multi-function peripheral  10  is formed to have approximately cuboid form, and the multi-function peripheral  10  is provided with a printer unit  11  for recording an image on a sheet such as the recording sheet S in accordance with the ink jet recording system. The multi-function peripheral  10  has various functions including, for example, the facsimile function and the printing function. The printer unit  11  corresponds to the image recording apparatus of the present teaching. 
     The printer unit  11  has a casing or housing body  14  which has an opening  13  formed on its front surface. A feed tray  20  and a discharge tray  21 , which are capable of accommodating the recording sheet S of various sizes, can be inserted into and withdrawn from the casing  14  via the opening  13  in the front-rear direction  8 . The bottom surface of the casing  14  abuts against the placement surface on which the multi-function peripheral  10  is placed. 
     As depicted in  FIG. 2 , the printer unit  11  is provided with, for example, a feed unit  15  for feeding the recording sheet S from the feed tray  20 , a recording unit  24  for recording the image on the recording sheet S, a first conveyance roller pair  54 , a second conveyance roller pair  55  and the like. 
     As depicted in  FIG. 1 , a scanner unit  12  is provided above the printer unit  11 . A casing  16  of the scanner unit  12  has the sizes in the front-rear direction  8  and the left-right direction  9  which are the same as those of the casing  14  of the printer unit  11 . Therefore, the casing  14  of the printer unit  11  and the casing  16  of the scanner unit  12  are integrated into one unit to form an outer shape of the multi-function peripheral  10  having the approximately cuboid form. The scanner unit  12  is a flatbed scanner. The structure of the flatbed scanner is known, any detailed explanation of which is omitted herein. Further, the scanner unit  12  may be provided with an automatic document feeder (ADF) for picking up a plurality of sheets of manuscript or document one by one and conveying each of the sheets. 
     &lt;Printer Unit  11 &gt; 
     The structure of the printer unit  11  will be explained in detail below. The printer unit  11  corresponds to the image recording apparatus of the present teaching. Further, a mechanism which conveys a sheet such as the recording sheet in the printer unit  11  corresponds to a sheet conveyance apparatus of the present teaching. 
     &lt;Feed Tray  20 &gt; 
     The feed tray  20  has such an outer shape that the lengths in the front-rear direction  8  and the left-right direction  9  are longer than the length in the up-down direction  7 , and the feed tray  20  has a box-shaped form of which upper side is open. The discharge tray  21  is provided on the front side of the upper surface of the feed tray  20 . The feed tray  20  can accommodate the recording sheet S by supporting, on the support surface, the recording sheet S having various sizes including, for example, the A4 size based on the Japanese Industrial Standards and the L size used for the photograph recording. The feed tray  20  is installed detachably to the internal space communicated with the opening  13  of the casing  14 . The feed tray  20  is movable back and forth in the front-rear direction  8  with respect to the casing  14  via the opening  13 . 
     &lt;Feed Unit  15 &gt; 
     As depicted in  FIG. 2 , the feed unit  15  is provided with a feed roller  25 , a feed arm  26 , a driving transmission mechanism  27  and a separation pad  23 . The feed unit  15  is provided over or above the feed tray  20  and under or below the recording unit  24 . The feed roller  25  is rotatably supported at a forward end portion of the feed arm  26 . The feed arm  26  is swingable in the direction of the arrow  29  with a rotational shaft  28  provided at a proximal end portion as the center of swing. Accordingly, the feed roller  25  can make the abutment and the separation with respect to the support surface of the feed tray  20 . Therefore, when the feed tray  20  is installed in the casing  14  while accommodating the recording sheet S, the feed roller  25  can abut against the recording sheet S accommodated in the feed tray  20 . The separation pad  23  is provided at the position at which the feed roller  25  abuts against the support surface of the feed tray  20  when the feed tray  20 , which accommodates no recording sheet S, is installed in the casing  14 . The separation pad  23  is formed of a material having a frictional coefficient with respect to the recording sheet S which is larger than a frictional coefficient with respect to the recording sheet S of the support surface of the feed tray  20 . 
     The driving force of a motor (not depicted) is transmitted to the feed roller  25  via the driving transmission mechanism  27 . The driving transmission mechanism  27  transmits the rotation transmitted to the rotational shaft  28  to the shaft of the feed roller  25  by means of a gear array including a plurality of gears. When the feed roller  25  is rotated in a state in which the feed roller  25  abuts against the recording sheet S disposed on the uppermost side of the recording sheets S supported on the support surface of the feed tray  20 , the uppermost recording sheet S is thereby fed toward a conveyance path  65 . When the recording sheet S is fed toward the conveyance path  65 , the forward end of the recording sheet S abuts against a separation member  35  provided on the back side in the front-rear direction  8  of the feed tray  20 . As a result, only the recording sheet S, which is disposed on the uppermost side, is conveyed while being separated from the recording sheets S which are disposed on the lower side. The recording sheets S, which are disposed on the lower side of the recording sheets S disposed at the uppermost side, are retained in the feed tray  20  without being dragged by the recording sheet S which is disposed on the uppermost side. 
     &lt;Conveyance Path  65 &gt; 
     As depicted in  FIG. 2 , the conveyance path  65 , which is provided in the internal space of the casing  14 , extends while being curved to make a U-turn upwardly from the back side of the feed tray  20 . Further, the conveyance path  65  is bent frontwardly from the back side of the printer unit  11 . After that, the conveyance path  65  further extends substantially in a straight line toward the front side of the printer  11  to arrive at the discharge tray  21 . The conveyance path  65  is roughly classified into a curved passage  65 A which makes the U-turn and a straight passage  65 B which is straight. 
     The curved passage  65 A is defined by an outer guide member  18 , an inner guide member  19  and a guide member  31 . Spaces through which the recording sheet S can pass are respectively defined between the outer guide member  18  and the inner guide member  19  and between the outer guide member  18  and the guide member  31 . The straight passage  65 B is defined by the recording unit  24 , a platen  42 , a guide member  32  and a guide member  33 . The recording unit  24  and the platen  42  are opposed to each other while being separated by the space through which the recording sheet S can pass, and the guide member  32  and the guide member  33  are opposed to each other while being separated by the space through which the recording sheet S can pass. 
     The recording sheet S, which is fed to the conveyance path  65  by the feed roller  25  of the feed tray  20 , is conveyed along the curved passage  65 A from the lower side to the upper side. In this procedure, the conveyance direction  17  is reversed from the backward direction to the forward direction. After that, the recording sheet S is conveyed from the back side to the front side without reversing the conveyance direction  17  through the straight passage  65 B. 
     The outer guide member  18  constitutes the outer guide surface of the curved passage  65 A when the recording sheet S is conveyed via the curved passage  65 A. The inner guide member  19  constitutes the inner guide surface of the curved passage  65 A when the recording sheet S is conveyed via the curved passage  65 A. Each of the guide surfaces may be constructed by one surface, or each of the guide surfaces may be constructed as an enveloping surface of forward ends of a plurality of ribs. 
     The guide member  31  is arranged over or above the inner guide member  19  just upstream from (on the back side of) the first conveyance roller pair  59 . The outer guide member  18  and the guide member  31  also define a bypass route  66  described later on. 
     &lt;Back Surface Cover  22 &gt; 
     As depicted in  FIG. 2 , the back surface cover  22  constructs a part of the back surface of the casing  14  while supporting the outer guide member  18 . The back surface cover  22  is swingably supported with respect to the casing  14  at its both right and left ends on the lower side. When the back surface cover  22  is swung so that its upper side is allowed to incline backwardly about the rotational shaft provided in the left-right direction  9  on the lower side, a part of the conveyance path  65  and a part of the bypass route  66  described later on are thereby released (exposed) to the outside of the casing  14 . 
     The outer guide member  18  is also swingably supported with respect to the casing  14  at the both left and right ends on the lower side in the same manner as the back surface cover  22 . The outer guide member  18  is also swingable so that the upper side thereof is allowed to incline backwardly about the rotational shaft in the left-right direction  9  on the lower side in a state in which the back surface cover  22  is swung so that the back surface cover  22  is allowed to incline backwardly. When the outer guide member  18  is swung so that the outer guide member  18  is allowed to incline backwardly, at least a part of the curved passage  65 A is thereby released (exposed). As depicted in  FIG. 2 , when the back surface cover  22  is closed to provide the upstanding state, then the outer guide member  18  is maintained in the upstanding state while being supported by the back surface cover  22  from the back, and the outer guide member  18  is opposed to the inner guide member  19  to define a part of the curved passage  65 A. 
     &lt;First Conveyance Roller Pair  54  and Second Conveyance Roller Pair  55 &gt; 
     As depicted in  FIG. 2 , the first conveyance roller pair  54  is provided on the upstream side of the recording unit  24  in the conveyance direction  17  of the recording sheet S along the conveyance path  65 . The first conveyance roller pair  54  has a first conveyance roller  60  and a pinch roller  61 . Similarly, the second conveyance roller pair  55  is provided on the downstream side of the recording unit  24  in the conveyance direction  17 . The second conveyance roller pair  55  has a second conveyance roller  62  and a spur roller  63 . The first conveyance roller  60  and the second conveyance roller  62  are rotated by transmitting the rotation of the motor (not depicted). When the first conveyance roller  60  and the second conveyance roller  62  are rotated in a state in which the recording sheet S is interposed between the respective rollers for constructing the first conveyance roller pair  59  and the second conveyance roller pair  55  respectively, the first conveyance roller pair  54  and the second conveyance roller pair  55  thereby transport the recording sheet S in the conveyance direction  17  along the conveyance path  65 . 
     &lt;Recording Unit  24 &gt; 
     As depicted in  FIG. 2 , the recording unit  24  is provided between the first conveyance roller pair  54  and the second conveyance roller pair  55 . The recording unit  24  is provided with a carriage  41  and a recording head  39 . The carriage  41  is supported by guide rails  43 ,  44  provided on the back side and the front side of the platen  42  so that the carriage  41  is reciprocatively movable in the left-right direction  9 . A known belt mechanism is provided for the guide rail  44 . The carriage  41  is coupled to an endless belt of the belt mechanism. The carriage  41  is reciprocatively moved in the left-right direction  9  along the guide rails  43 ,  44  in accordance with the rotation of the endless belt. When the carriage  41  and the recording head  39  are opposed to the platen  42  with the space intervening therebetween, the carriage  41 , the recording head  39  and the platen  42  define a part of the straight passage  65 B. 
     The recording head  39  is carried on the carriage  41 . A plurality of nozzles  38  are formed on the lower surface of the recording head  39 . Inks are supplied from ink cartridges (not depicted) to the recording head  39 . The recording head  39  selectively discharges the inks as minute ink droplets from the plurality of nozzles  38 . The ink droplets are discharged to the recording sheet S supported by the platen  42  from the nozzles  38  when the carriage  41  is moved in the left-right direction  9 . The discharged ink droplets adhere to the recording sheet S on the platen  42 , and thus an image is recorded on the recording sheet S. 
     &lt;Bypass Route  66 &gt; 
     As depicted in  FIG. 2 , the opening  64  is provided over or above the back surface cover  22  at the back surface of the casing  14 . The bypass route  66 , which extends from the opening  64  to the first conveyance roller pair  54 , is formed in the casing  14 . The bypass route  66  extends from the upper backward to the lower frontward in the casing  14 . The bypass route  66  is defined, for example, by the guide member  31 , the outer guide member  18  and the back surface cover  22 . The guide member  31  constructs the guide surface on the upper side when the recording sheet S is conveyed via the bypass route  66 . The outer guide member  18  and the back surface cover  22  construct the guide surface on the lower side when the recording sheet S is conveyed via the bypass route  66 . Both of the curved passage  65 A and the straight passage  65 B of the conveyance path  65  are arranged under or below the bypass route  66 . A part of the bypass route  66  is released (exposed) to the outside of the casing  14  together with a part of the conveyance path  65  in accordance with the swing of the outer guide member  18  and the back surface cover  22  so that their upper sides are allowed to incline backwardly. 
     The recording sheet S, which is accommodated in the bypass tray  70  described later on, is guided obliquely downwardly along the bypass route  66 . The recording sheet S is guided along the straight passage  65 B of the conveyance path  65 , and the recording sheet S is conveyed by the first conveyance roller pair  54 . Further, the image recording is performed on the recording sheet S by the recording unit  24 , and the recording sheet S is discharged to the discharge tray  21 . In this way, the recording sheets S, which are accommodated in the bypass tray  70 , are each conveyed via the route having the substantially straight shape (route in which the front surface and the back surface of the recording sheet S are not reversed in the up-down direction  7 ). 
     &lt;Bypass Tray  70 &gt; 
     As depicted in  FIGS. 1 and 3 , the bypass tray  70  is provided on the back surface side of the multi-function peripheral  10 . The bypass tray  70  can load or accommodate the recording sheets independently from the feed tray  20 . The bypass tray  70  corresponds to a sheet support unit. 
     As depicted in  FIGS. 1 and 5 , a fixed unit  68 , which extends downward to cover the opening  64  (see  FIG. 2 ) therewith, is formed on the back surface side of the casing  16  of the scanner unit  12 . The fixed unit  68  constitutes a part of the bypass tray  70  on the downstream side in the conveyance direction. As depicted in  FIG. 3 , a movable unit  69  is provided on the upper side of the fixed unit  68  so as to be rotatable with respect to the fixed unit  68 . The bypass tray  70  is constructed by the fixed unit  68  and the movable unit  69 . 
     As depicted in  FIG. 5 , a slit-shaped opening  67 , which extends in the left-right direction  9 , is formed on the upper surface of the fixed unit  68 . In the bypass tray  70 , a passage is formed via the opening  67  to arrive at the bypass route  66  (see  FIG. 2 ). As depicted in  FIG. 3 , a support member  75  including a support surface  74  is provided in the fixed unit  68 . The support surface  74  extends obliquely downward to the bypass route  66  (see  FIG. 2 ). The lower end of the support member  75  forms a part of the guide surface which guides the recording sheet conveyed via the bypass route  66 . 
     As depicted in  FIGS. 3 and 4 , the separation piece  72  is provided below the support member  75  of the fixed unit  68 . The separation piece  72  is positioned at a height which is substantially the same as that of the opening  64  in the up-down direction  7 . The upper surface of the separation piece  72  is a surface against which the forward ends of the recording sheets supported by the bypass tray  70  abut. On the upper surface of the separation piece  72 , a plurality of teeth  73  (see  FIG. 4 ) are aligned in the front-rear direction  8  to project upward from the upper surface. The forward ends of recording sheets supported by the bypass tray  70  are disentangled or unraveled by the teeth  73 . The separation piece  72  corresponds to a separation unit. In  FIG. 3 , the illustration of the teeth is omitted. 
     As depicted in  FIG. 5 , a reinforcing member  84 , which rotatably supports an unillustrated driving shaft of the feed roller  76 , is provided above the support surface  74  on the upper end side of the support member  75 . The driving force is transmitted from an unillustrated motor to the driving shaft of the feed roller  76  supported by the reinforcing member  84  via a driving transmission unit  79 , and thus the feed roller  76  is allowed to rotate. 
     As depicted in  FIG. 5 , the driving transmission unit  79 , which is composed of a plurality of pinion gears, is provided on the right side of the fixed unit  68  in the left-right direction  9 . The driving force is transmitted to the driving transmission unit  79  from the unillustrated motor provided in the casing  14  of the printer unit  11 . The driving shaft of the feed roller  76  extends in the left-right direction  9 , and one end thereof is meshed or engaged with the pinion gears constituting the driving transmission unit  79 . The other end of the driving shaft extends to the center of the fixed unit  68  in the left-right direction  9 . 
     The driving shaft of the feed roller  76  swingably supports an arm  78 . That is, the arm  78  is swingably around the driving shaft of the feed roller  76 . The feed roller  76  is rotatably supported by the arm  78  on the side of a rotation forward end. The arm  78  extends downward from the driving shaft of the feed roller  76  toward the support surface  74  of the support member  75 . The arm  78  is arranged at the center of the fixed unit  68  in the left-right direction  9 . 
     The feed roller  76  is connected to the driving shaft by an unillustrated endless belt. The rotation of the driving shaft is transmitted to the feed roller  76  via the endless belt to rotate the feed roller  76 . The feed roller  76  is rotated in a state of being allowed to abut against the recording sheet disposed on the uppermost side of the recording sheets supported by the support surface  74  of the bypass tray  70 , and thus the uppermost recording sheet is fed via the bypass route  66 . The recording sheets, which are disposed on the lower side of the uppermost recording sheet, are disentangled or unraveled by the teeth  73  of the separation piece  72  and they are retained in the bypass tray  70  without being dragged by the recording sheet disposed on the uppermost side. In this way, a feed unit, which is constructed by the feed roller  76 , the driving shaft and the arm  78  is arranged in a space above the support surface  74  at the outside of the casing  14 . 
     As depicted in  FIGS. 3 and 4 , the movable unit  69  is provided on the upper side of the fixed unit  68  to be rotatable with respect to the fixed unit  68 . The movable unit  69  is rotatable between the upstanding state in which the movable unit  69  upstands in the up-down direction  7  as depicted in  FIG. 1  and the inclined or laid-down state in which the movable unit  69  is inclined with respect to the up-down direction  7  as depicted in  FIG. 3 . The upstanding state is a state for reducing the space which is occupied by the movable unit  69  on the back surface side of the casing  14 . The bypass tray  70  is not used in a case that the movable unit  69  is in the upstanding state. The back surface of the movable unit  69  in the upstanding state is substantially parallel to the back surface of the casing  14 . The inclined state is a state as follows. That is, the movable unit  69  is inclined obliquely upward toward the outside of the casing  14 , so that inclined support surfaces  74 ,  90  are allowed to form substantially one flat surface. In this situation, the bypass tray  70  is available. Whether the movable unit  69  is allowed to be in the upstanding state or the inclined state can be arbitrarily selected in accordance with the operation of a user. 
     As depicted in  FIG. 3 , side walls  86 ,  87  are provided on both sides of the movable unit  69  in the left-right direction  9 . The side walls  86 ,  87  cover parts of the both sides of the fixed unit  68  in the left-right direction  9 . The driving transmission unit  79 , which is provided on the right side of the fixed unit  68  in the left-right direction  9 , is covered with the side wall  86  of the movable unit  69 . 
     As depicted in  FIG. 3 , a support member  88  is provided to span the side walls  86 ,  87  of the movable unit  69 . In the inclined state of the movable unit  69 , a support surface  90  provided on the upper surface of the support member  88  and the support surface  74  form substantially the same flat surface. Thus, a surface formed by the support surface  74  and the support surface  90  supports the recording sheet in the bypass tray  70 . In the upstanding state of the movable unit  69 , the support surface  90  is perpendicular to the placement surface for the multi-function peripheral  10 ; in other words, the support surface  90  extends in the up-down direction  7  and the left-right direction  9 . The support surface  90  corresponds to a first surface. In this embodiment, the placement surface on which the multi-function peripheral  10  is placed is a surface which expands in the left-right direction  9  and the front-rear direction  8 . For example, the placement surface is a horizontal surface perpendicular to the vertical direction (the direction of gravitational force). Here, “substantially one flat surface (the same flat surface)” means a flat surface on which the supported recording sheet is neither bent nor flexed even when there is a small difference in height between two surfaces constituting the flat surface; in other words, it means a flat surface on which the recording sheet S is supported so that separation performance is stably obtained by the separation piece  72 . 
     As depicted in  FIG. 3 , the support member  88  is provided with a pair of side guides  92 . The side guides  92  are separated from each other in the left-right direction  9  to form a pair, and the side guides  92  protrude upward from the support surface  90 . The side guide  92  includes a guide surface  93  which extends in the conveyance direction of the recording sheet S in the bypass tray  70 . In a case that the recording sheet S on the support surface  90  is conveyed, the edge of the recording sheet in the conveyance direction is guided by the guide surface  93 . 
     The side guide  92  has a support surface  91  along the support surface  90  of the support member  88 . That is, the side guide  92  is L-shaped such that the guide surface  93  is perpendicular to the support surface  91 . Although there is a small difference in height between the support surfaces  90 ,  91 , the support surface  91  is substantially flush with the support surface  90 . The support surface  91  supports the recording sheet with the support surfaces  74 ,  90 . The distance, by which the side guides  92  are separated from each other in the left-right direction  9 , is variable. Accordingly, the edges of the recording sheets having various sizes supported by the support surfaces  90 ,  91  can be guided by the guide surface  93  of the side guide  92 . 
     As depicted in  FIGS. 8 and 9 , an extension member  89  is provided for the support member  88 . The extension member  89  is a flat plate-shaped member and the extension member  89  can be housed in the inner space formed below the support surface  90  of the support member  88 . The extension member  89  is slidably movable between a housed state depicted in  FIGS. 6 and 7  and an extended state depicted in  FIGS. 8 and 9 . In the housed state, the extension member  89  is housed in the inner space of the support member  88 . In the extended state, the extension member  89  is extended above the support member  88 . The housed state corresponds to a fifth position and the extended state corresponds to a sixth position. 
     A tray cover  94  is provided at the upper end of the extension member  89 . The tray cover  94  is provided for the extension member  89  to be rotatable around a shaft  82  (see  FIG. 4 ). The tray cover  94  is a member in a flat plate shape capable of sealing the openings of the bypass tray  70  on the upper end side and covering the space on the side of the support surface  90 . The tray cover  94  corresponds to a first plate member. 
     As depicted in  FIG. 1 , in a state that the movable unit  69  is in the upstanding state and the extension member  89  is in the housed state, the tray cover  94  is rotatable to arrive at the position where the openings of the bypass tray  70  on the upper end side are covered with the tray cover  94 . Further, as depicted in  FIGS. 6 and 7 , in a state that the movable unit  69  is in the inclined state and the extension member  89  is in the housed state, the tray cover  94  is rotatable to arrive at the position where the openings of the bypass tray  70  on the upper end side are open. The position where the tray cover  94  makes the openings of the bypass tray  70  on the upper end side open ( FIGS. 6 and 7 ) corresponds to the first position and the position where the openings of the bypass tray  70  on the upper end side are sealed with the tray cover  94  ( FIGS. 1, 3 and 4 ) corresponds to the second position. 
     In a case that the tray cover  94  is in the position where the upper end side of the bypass tray  70  is open ( FIGS. 6 and 7 ), the tray cover  94  extends obliquely upward to extend the support surface  90 , so that the upper end side of the recording sheet protruding from the support surface  90  can be supported by the tray cover  94 . 
     As depicted in  FIGS. 6 to 9 , an inner surface  95 , which faces upward in the up-down direction  7  in the same manner as the support surface  90  when the tray cover  94  is in the open state, is formed of a plurality of surfaces with a curved surface and concavities and convexities. A proximal end  96  of the inner surface  95  is positioned on the side nearer to the placement surface of the multi-function peripheral  10  than a virtual plane  6  (see  FIGS. 7 and 9 ) which includes the support surface  90  when the movable unit  69  is in the inclined state. That is, the proximal end  96  is positioned on the lower side in the up-down direction  7  than the virtual plane  6 . The proximal end  96  is arranged close to the lower end side of the tray cover  94  which is the rotation end of the tray cover  94 , i.e., close to the support surface  90 . The extension member  89  can be housed in the inner space below the support surface  90  of the support member  88  and the tray cover  94  is rotatably connected to the upper end of the extension member  89 , and thus the proximal end  96  of the tray cover  94  is positioned below the virtual plane  6 . 
     A distal end  97  of the inner surface  95  of the tray cover  94  is positioned substantially on the virtual plane  6 . The distal end  97  is arranged on the upper end side of the tray cover  94  which is the rotation forward end of the tray cover  94 , i.e., away from the support surface  90 . The distal end  97  extends in the left-right direction  9  and the entire part of the distal end  97  in the left-right direction  9  is substantially positioned on the virtual plane  6 . The distal end  97  is substantially positioned on the virtual plane  6  regardless of the slide position of the extension member  89 . In this context, a state “substantially positioned on the virtual plane  6 ” means a state in which the recording sheet is supported by the plurality of surfaces (parts) without being bent or curved even when the plurality of surfaces (parts) are not strictly on the virtual plane  6 ; in other words, it means a state in which the recording sheet is supported so that separation performance is stably obtained by the separation piece  72 . 
     A convex portion  98  is provided in the distal end  97  of the inner surface  95  of the tray cover  94  at the center in the left-right direction  9 . In a case that the tray cover  94  is in the first position, the convex portion  98  projects upward from the inner surface  95 . A part (the side of the distal end  97 ) of an upper surface  99  of the convex portion  98  is substantially positioned on the virtual plane  6 . Convex pieces  100  are provided at both ends of the tray cover  94  in the left-right direction  9 . Each of the convex pieces  100  has a projection  100 A lightly engaged with a predetermined part of the bypass tray  70  to prevent the tray cover  94  in the second position from easily rotating toward the first position. Therefore, in a case that the user rotates the tray cover  94  with respect to the bypass tray  70 , the user is capable of having click feeling lightly. Further, the convex pieces  100  are arranged in the tray cover  94  at both ends in the left-right direction  9  on the side of the distal end  97 . Thus, in a case that the recording sheet is normally supported by the support surface  90  of the bypass tray  70 , the convex pieces  100  do not come into contact with the recording sheet. Accordingly, there are no parts or portions projecting above the virtual plane  6  in the inner surface  95 , which is capable of coming into contact with the recording sheet normally supported by the support surface  90  of the bypass tray  70 . 
     As depicted in  FIGS. 10 to 13 , a support member  101  is provided in the tray cover  94 . The support member  101  is an elongated flat plate. The support member  101  is rotatable or swingable between a housed state in which the support member  101  is housed in the tray cover  94  and a projecting state in which the support member  101  projects upward from the distal end  97  of the tray cover  94  in the open state. The support member  101  corresponds to a second plate member. The housed state corresponds to a third position and the projecting state corresponds to a fourth position. 
     A through hole  102  is formed in the support member  101  on the side of a rotation base end. The through hole  102  is supported by a shaft  103  of the tray cover  94 , which makes it possible to rotatably support the support member  101  with respect to the tray cover  94 . A rotation support unit is formed of the shaft  103 , a cam  106  and an inner surface member  104  which will be described later. 
     A part of the support member  101  on the side of the rotation base end is formed to have an approximately-semicircular curved surface. A notch  109  is formed in a part of the approximately-semicircular curved surface to follow the circumferential direction. On both ends of the notch  109  in the circumferential direction, end surfaces  110 ,  111  extending in a radial direction of the through hole  102  are formed. The end surface  110  is allowed to abut against the cam  106  described later on, and thus the rotation position of the support member  101  in the housed state is defined. 
     A cam follower  112 , which projects in a direction of axis of the though hole  102 , is provided in the rotation base end having the semicircular shape of the support member  101  at the farthest end in a longitudinal direction. The through hole  102  of support member  101  is inserted through the shaft  103  of an outer surface member  105  in a state that the cam follower  112  projects toward the outer surface member  105 . 
     The tray cover  94  includes the inner surface member  104  constituting the inner surface  95  (proximal end  96 , distal end  97 , convex portion  98 ) and the outer surface member  105  positioned on the side opposite to the inner surface  95 . In the outer surface member  105 , the cylindrical shaft  103  projects toward the inner surface member  104  at a position corresponding to the convex portion  98  of the inner surface member  104 . The shaft  103  has flat surfaces in which the upper side and the lower side of the cylindrical shape in the up-down direction  7  are concave inward in the radial direction. The flat surfaces enable the support member  101  to change the posture thereof such that the support member  101  in the projecting state is inclined to the shaft  103  as will be described later. The inner surface member  104  corresponds to a support plate. 
     The cam  106  is provided around the shaft  103 . The cam  106  is a circular arc-shaped rib provided around the shaft  103  and the cam  106  projects toward the inner surface member  104  from the outer surface member  105 . In a case that the tray cover  94  is in the first position, the cam  106  is provided to extend from the left side in the left-right direction  9  to the lower side in the up-down direction  7  with respect to the shaft  103 . The projecting end of the cam  106  has different positions depending on the position in the circumferential direction with the shaft  103  as the center. That is, the height of projection of the cam  106  from the outer surface member  105  (hereinafter simply referred to as the height of the cam  106 ) is lowest at a left-side position with respect to the shaft  103  in the left-right direction  9 , and the height of the cam  106  is highest at the lower-side position with respect to the shaft  103  in the up-down direction  7 . The height of the cam  106  changes smoothly from the position on the left side with respect to the shaft  103  in the left-right direction  9  to the position on the upper side with respect to the shaft  103  in the up-down direction  7 . In other words, the upper surface of the cam  106  constitutes an inclined surface, the inclination of which changes smoothly from the position on the left side with respect to the shaft  103  in the left-right direction  9  to the position on the upper side with respect to the shaft  103  in the up-down direction  7 . A recess portion  113 , which is concave toward the outer surface member  105 , is provided in the projecting end of the cam  106  on the lower side in the up-down direction  7 . The cam follower  112  can be engaged with the recess portion  113 . 
     The cam follower  112  of the support member  101  can abut against the projecting end of the cam  106  in a state that the shaft  103  of the outer surface member  105  is inserted through the through hole  102  of the support member  101 . The support member  101  is allowed to rotate toward the tray cover  94  in the state that the shaft  103  is inserted through the through hole  102 , so that the support member  101  is housed between the inner surface member  104  and the outer surface member  105 . That is, the support member  101  is in the housed state in which the support member  101  is housed in the tray cover  94 . In this housed state, the end surface  110  of the notch  109  of the support member  101  abuts against the cam  106 . By allowing the end surface  110  to abut against the cam  106 , the rotation position of the support member  101  in the housed state is determined. In this housed state, the inner surface  95  of the inner surface member  104  is parallel to a support surface  107  of the support member  101 . 
     The support surface  107  of the support member  101  faces to the direction which is the same as that of the inner surface  95  of the tray cover  94 . In the housed state of the support member  101 , the support surface  107  is rarely exposed to the outside of the tray cover  94 . A notch  108  is formed in the distal end  97  of the inner surface member  104 . A part of the support surface  107  of the support member  101  is exposed to the outside through the notch  108 . The support surface  107  corresponds to the third surface. 
     When the user takes and pulls out the part of the support surface  107  of the support member  101  in a state of being exposed through the notch  108  of the inner surface member  104 , the support member  101  is rotated around the shaft  103 . In a state that the rotated support member  101  is allowed to fully protrude from the tray cover  94 , the cam follower  112  is engaged with the recess portion  113  of the cam  106 . By letting the cam follower  112  engage with the recess portion  113  of the cam  106 , the rotation position of the support member  101  in the projecting state is defined. As depicted in  FIG. 13 , a stopper  115  is formed on the outer surface member  105  to prevent the support member  101  from further rotating. The stopper  115  is a rib protruding from the outer surface member  105 , and has a substantially square-bracket (‘]’) shape as viewed from above. When the cam follower  112  is engaged with the recess portion  113  of the cam  106 , the support member  101  makes a contact with the stopper  115 . Therefore, the support member  101  can not rotate any further beyond the stopper  115 . 
     The rotation of the support member  101  around the shaft  103  moves the cam follower  112  in a state that the cam follower  112  is brought into sliding-contact with the projecting end of the cam  106 , thereby changing the posture of the support member  101 . In the process in which the support member  101  is rotated from the housed state to the projecting state, the cam follower  102  slidably moves along the projecting end of the cam  106 ; a part of the support member  101  on the side of the cam follower  112  moves to a position farthest from the outer surface member  105 ; and a part of the inner circumferential surface of the through hole  102  positioned farthest from the cam follower  112  moves in a direction closer to the outer surface member  105 . Accordingly, the posture of the support member  101  is changed so that a part of the support member  101  on the side of rotation forward end protruding upward from the tray cover  94  in the first position moves downward in the up-down direction  7 . As depicted in  FIG. 11 , when the support member  101  is in the housed state, the support surface  107  of the support member  101  (see in  FIG. 10 ) is substantially parallel to the outer surface member  105 , but is not parallel to the virtual plane  6 . Assuming that the support member  101  is rotated from the housed state to the projecting state with maintaining a state in which the support surface  107  of the support member  101  is substantially parallel to the outer surface member  105 , then the support member would be projected upward in the up-down direction  7  with respect to the virtual plane  6 . On the other hand, in this embodiment, in the process in which the support member  101  is rotated from the housed state to the projecting state, the cam follower  102  slidably moves along the projecting end of the cam  106 , as described above. As depicted in  FIG. 13 , the cam  106  is configured so that the height of the cam  106  is lowest at a left-side position with respect to the shaft  103  in the left-right direction  9 , and that the height of the cam  106  is highest at the lower-side position with respect to the shaft  103  in the up-down direction  7 . Therefore, when the support member  101  is rotated from the housed state to the projecting state, the posture of the support member  101  is changed so that the part of the support member  101  on the side of rotation forward end moves downward in the up-down direction  7 , in accordance with the height of the cam  106 . 
     The engagement of the cam follower  112  with the recess portion  113  of the cam  106  positions the support member  101  in the projecting state. The support surface  107  of the support member  101  in the projecting state around the through hole  102  is sandwiched between the inner surface member  104  of the tray cover  94  and the cam  106  to be maintained in a posture in which the part of the support member  101  on the rotation forward end is moved downward. As a result, the support surface  107  of the support member  101  in the projecting state is substantially parallel to the virtual plane  6 . 
     &lt;Operation of Printer Unit  11 &gt; 
     In the following, an explanation will be made about the operation of the printer unit  11  as performed when the feed tray  20  and the bypass tray  70  are used respectively. 
     In a case that the bypass tray  70  is not used, the movable unit  69  is in the upstanding state as depicted in  FIG. 1 . Thus, the profile or project area of the movable unit  69  as viewed in a plan view is decreased, thereby making it possible to reduce the space of the multi-function peripheral  10  on the back surface side. Further, the tray cover  94  is rotated to the position where the openings at the upper end of the bypass tray  70  are covered with the tray cover  94 . If an enough space is provided on the back surface side of the multi-function peripheral  10 , the movable unit  69  may be still in the inclined state even when the bypass tray  70  is not used. 
     When the feed tray  20  is used, the recording sheet having a desired size is set to the feed tray  20 . Specifically, a plurality of recording sheets are placed on the feed tray  20  in a state that the recording sheets are stacked. The feed tray  20  on which the recording sheets are placed is allowed to be in an installed state by being inserted into the casing  14  through the opening  13 . In this state, the feed roller  25  abuts against the uppermost recording sheet of the plurality of recording sheets placed on the feed tray  20 . The printer unit  11  feeds the recording sheet from the feed tray  20  based on the input by the user, the printing data and/or the like. 
     When the instruction to start the printing is accepted, the printer unit  11  drives the unillustrated motor to rotate the feed roller  25 , the first conveyance roller pair  54  and the second conveyance roller pair  55  at predetermined timings. The uppermost recording sheet is fed from the feed tray  20  to the conveyance path  65  in response to the rotation of the feed roller  25 . The recording sheet that is fed from the feed tray  20  is guided by the curved passage  65 A of the conveyance path  65 , and then arrives at the first conveyance roller pair  54 . The ink droplets are discharged from the recording head  39  and a desired image is recorded on the recording sheet conveyed to the recording unit  24  by being interposed by the first conveyance roller pair  54 . The recording sheet, for which the image recording has been completed, is conveyed through the straight passage  65 B by being interposed by the second conveyance roller pair  55 , and then the recording sheet is discharged on the discharge tray  21 . 
     In a case that the bypass tray  70  is used, the movable unit  69  is in the inclined state as depicted in  FIG. 3 . Accordingly, the support surfaces  74 ,  90  form one flat surface in the bypass tray  70 . Further, as depicted in  FIG. 6 , the tray cover  94  is rotated to the position (first position) where the openings of the bypass tray  70  on the upper end side are open. 
     As depicted in  FIG. 8 , the extension member  89  is pulled out as appropriate depending on the size of the recording sheet set in the bypass tray  70 . Further, the pair of side guides  92  is moved to the position corresponding to the width of the recording sheet set in the bypass tray  70 . The rotation of the tray cover  94  to the open position substantially positions the distal end  97  and the upper surface  99  of the tray cover  94  on the virtual plane  6  including the support surfaces  74 ,  90 . 
     In a case that the recording sheet, which protrudes upward from the extension member  89  and the tray cover  94 , is set in the bypass tray  70  and that the tray cover  94  is in the open position, the support member  101  in the housed state is rotated to be in the projecting state. The support surface  107  of the support member  101  in the projecting state is substantially parallel to the virtual plane  6 . The distance (difference in height) between the support surface  107  and the virtual plane  6  corresponds to a thickness of the inner surface member  104  of the tray cover  94 . In this context, the phrase “substantially parallel to the virtual plane  6 ” means as follows. That is, even when a surface is not exactly parallel to the virtual plane  6 , the surface is parallel to the virtual plane  6  to the extent that the recording sheet is supported by the surface without being bent or curved; in other words, a surface is parallel to the virtual plane  6  to the extent that the recording sheet is supported so that separation performance is stably obtained by the separation piece  72 . 
     In the case that the bypass tray  70  is used, the recording sheet having a desired size is set in the bypass tray  70 . In particular, the recording sheets having a desired size are placed on the support surfaces  74 ,  90  of the bypass tray  70  in a state that the recording sheets are stacked. The upper ends of the recording sheets placed on the support surfaces  74 ,  90  are supported also by a part of the upper surface  99  and the distal end  97  of the tray cover  94 . Since the support surfaces  74 ,  90 , the distal end  97  and the part of the upper surface  99  are substantially positioned on the same virtual plane  6 , the recording sheets placed on the bypass tray  70  are neither bent nor flexed. Further, in a case that the support member  101  is used, the support surface  107  of the support member  101  is substantially parallel to the virtual plane  6 , and thus the recording sheets are neither bent nor flexed greatly at the boundary between the distal end  97  of the tray cover  94  and the support member  101 . 
     The feed roller  76  of the bypass tray  70  abuts against the recording sheet disposed on the uppermost side of the recording sheets set in the bypass tray  70 . Further, the lower ends of the recording sheets abut against the separation piece  72 . The printer unit  11  feeds the recording sheet from the bypass tray  70  based on the input by the user, the printing data and/or the like. 
     When the instruction to start the printing is accepted, the printer unit  11  drives the unillustrated motor to rotate the feed roller  76 , the first conveyance roller pair  54  and the second conveyance roller pair  55  at predetermined timings. The uppermost recording sheet is fed from the bypass tray  70  to the bypass route  66  in response to the rotation of the feed roller  76 . The recording sheet fed through the bypass route  66  is further conveyed through the straight passage  65 B of the conveyance path  65 , and then arrives at the first conveyance roller pair  54 . During this process, the outer guide member  18 , the back surface cover  22  and the guide member  31 , those of which define the bypass route  66  and the straight passage  65 B, guide the recording sheet toward the first conveyance roller pair  54 . The ink droplets are discharged from the recording head  39  and a desired image is recorded on the recording sheet conveyed to the recording unit  24  by being interposed by the first conveyance roller pair  54 . The recording sheet, for which the image recording has been completed, is discharged on the discharge tray  21  by the second conveyance roller pair  55 . 
     Effect of Embodiment 
     According to this embodiment, the support surfaces  74 ,  90 , the distal end  97  and the part of the upper surface  99  of the bypass tray  70  are substantially positioned on the same virtual plane  6 , and thus the recording sheet set in the bypass tray  70  is neither bent nor flexed. Further, since the support surface  107  of the support member  101  is substantially parallel to the virtual plane  6 , the recording sheet is neither bent nor flexed at the boundary between the distal end  97  of the tray cover  94  and the support member  101 . Accordingly, the recording sheet maintained in a posture along the virtual plane  6  abuts against the separation piece  72 , and thus the separation piece  72  can achieve the separation performance stably. 
     The support member  101  is rotatably supported by the shaft  103  inserted through the through hole  102 , the cam  106  provided around the shaft  103 , and the inner surface member  104  which sandwiches the support member  101  between itself and the cam  106 . Thus, the support member  101  is rotatably supported by a simple structure. 
     The inner surface member  104  constitutes a part of the distal end  97  of the inner surface  95  of the tray cover  94 , which increases the area of the distal end  97  and allows the recording sheet to be stably supported. 
     The bypass tray  70  includes the fixed unit  68  provided in the casing  14  and the movable unit  69  rotatably provided in the fixed unit  68 . Thus, it is possible to reduce an area for installing the multi-function peripheral  10  by rotating the movable unit  69 . 
     The state of the movable unit  69  is changed to the housed state in which the support surface  90  is perpendicular to the placement surface of the multi-function peripheral  10 , and thus it is possible to reduce the area for installing the multi-function peripheral  10  efficiently. 
     In a state that the movable unit  69  is in the housed state, the tray cover  94  can rotate to the position where the tray cover  94  covers a space on the side of the support surface  90 . Thus, it is possible to prevent foreign matters, dust and the like from entering the space on the side of the support surface  90  of the bypass tray  70 . 
     The side guides  92  are provided in the bypass tray  70 , and thus the position adjustment of the edge of the recording sheet is easily performed in the bypass tray  70 . 
     The feed unit includes the feed roller  76  which rotates while abutting against the recording sheet disposed at the uppermost side of the recording sheets supported by the support surface  90 , the distal end  97  and the part of the upper surface  99  of the bypass tray  70 . Thus, in the process in which the recording sheet is fed by the feed roller  76 , one recording sheet is separated from the recording sheets supported by the support surface  90 , the distal end  97  and the upper surface  99  by use of the separation piece  72 , and then the one recording sheet is fed to the bypass route  66 . 
     The extension member  89  is provided in the bypass tray  70 , and thus the recording sheet having a large size can be supported by the bypass tray  70 .