Patent Publication Number: US-10329107-B2

Title: Conveying apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application claims priority from Japanese Patent Application No. 2017-068749, which was filed on Mar. 30, 2017, the disclosure of which is herein incorporated by reference in its entirety. 
     BACKGROUND 
     The following disclosure relates to a conveying apparatus configured to convey a sheet. 
     There is conventionally known a conveying apparatus including an outer guide member and an inner guide member which guide a sheet to a conveying roller pair. The conveying roller pair is constituted by a conveying roller and a pinch roller which is brought into pressing contact with the conveying roller. In this conveying apparatus, hooks provided on the outer guide member respectively hold bearings fitted on opposite end portions of the conveying roller. The outer guide member is engaged with and positioned to the frame. The inner guide member is assembled and secured to the frame. 
     SUMMARY 
     In the above-described conveying apparatus, the outer guide member is positioned to a rotation shaft of the conveying roller and the frame, but the inner guide member is positioned only to the frame. That is, the inner guide member is not positioned to the rotation shaft of the conveying roller. Thus, there is a possibility that the sheet to be conveyed to a nip position at which the conveying roller and the pinch roller nip the sheet is not guided appropriately. This may result in an occurrence of a sheet jam because the sheet conveyed toward the nip position cannot pass through the nip position by contacting the conveying roller or the pinch roller, for example. 
     Accordingly, an aspect of the disclosure relates to a conveying apparatus capable of appropriately guiding a sheet to a nip position at which a conveying roller and a driven roller nip the sheet. 
     One aspect of the disclosure relates to a conveying apparatus, comprising: a rotation shaft configured to be driven to rotate; a conveying roller secured to the rotation shaft; a driven roller opposed to the conveying roller and configured to cooperate with the conveying roller to nip a sheet at a nip position to convey the sheet; a supporter supporting the rotation shaft such that the rotation shaft is rotatable; and a first guide and a second guide defining a conveyance path that guides the sheet from an upstream side of the nip position in a conveying direction toward the nip position, the first guide and the second guide being opposed to each other in an opposed direction orthogonal to each of the conveying direction and an axial direction of the rotation shaft, wherein the first guide comprises: a first guide surface defining the conveyance path; and a first engaging portion engaged with the rotation shaft at a position different from a position of the supporter in the axial direction of the rotation shaft, and wherein the second guide comprises: a second guide surface defining the conveyance path; and a second engaging portion engaged with the rotation shaft at a position different from the position of the supporter and a position of the first engaging portion in the axial direction of the rotation shaft. 
     Another aspect of the disclosure relates to a conveying apparatus, comprising: a rotation shaft configured to be driven to rotate; a conveying roller secured to the rotation shaft; a driven roller opposed to the conveying roller and configured to cooperate with the conveying roller to nip a sheet at a nip position to convey the sheet; a bearing supporting the rotation shaft such that the rotation shaft is rotatable; a supporter on which the bearing is mounted; and a first guide and a second guide defining a conveyance path that guides the sheet from an upstream side of the nip position in a conveying direction toward the nip position, the first guide and the second guide being opposed to each other in an opposed direction orthogonal to each of the conveying direction and an axial direction of the rotation shaft, wherein the first guide is supported by the supporter and comprises a first recess having a U-shape in cross section and opening upward, wherein the second guide is supported by the supporter and comprises a second recess having a U-shape in cross section and opening upward, and wherein the rotation shaft is supported by the bearing in a state in which the rotation shaft is inserted in the first recess and the second recess. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The objects, features, advantages, and technical and industrial significance of the present disclosure will be better understood by reading the following detailed description of the embodiment, when considered in connection with the accompanying drawings, in which: 
         FIG. 1  is a side elevational view in cross section, illustrating a multi-function peripheral (MFP) according to the present embodiment; 
         FIG. 2  is a perspective view of a third supplier viewed from a front right side thereof; 
         FIG. 3  is an exploded partial perspective view of a main body portion viewed from a front right side thereof; 
         FIG. 4  is an exploded partial perspective view of the main body portion viewed from a front left side thereof; 
         FIG. 5  is a cross-sectional view taken along line V-V in  FIG. 2 ; 
         FIG. 6  is an enlarged view of a main portion of  FIG. 5 ; 
         FIG. 7  is a perspective view of a first guide member viewed from a front left side thereof and 
         FIG. 8  is a perspective view of a second guide member viewed from a rear right side thereof. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENT 
     Hereinafter, there will be described one embodiment by reference to the drawings. It is to be understood that the following embodiment is described only by way of example, and the disclosure may be otherwise embodied with various modifications without departing from the scope and spirit of the disclosure. A multi-function peripheral (MFP)  10  is used in a state illustrated in  FIG. 1  in which the MFP  10  is disposed on a horizontal plane. In the following description, the up and down direction  7  is defined in this using state. Also, a front and rear direction  8  is defined by regarding a side of the MFP  10  on which an opening  13  is formed as a front side (a front surface). A right and left direction  9  is defined in a state in which the MFP  10  is viewed from the front. The up and down direction  7 , the front and rear direction  8 , and the right and left direction  9  are orthogonal to each other. A direction in which a first supplier  14 , a second supplier  15 , and a third supplier  16  are inserted into and removed from the MFP  10  is defined as the front and rear direction  8 . A direction orthogonal to the up and down direction  7  and the front and rear direction  8  is defined as the right and left direction  9 . In the present embodiment, the up and down direction  7  coincides with the vertical direction, and the front and rear direction  8  and the right and left direction  9  coincide with the horizontal direction in the using state. 
     There will be explained the MFP  10  according to the present embodiment. 
     Overall Configuration of MFP  10   
     As illustrated in  FIG. 1 , the MFP  10  (as one example of an image recording apparatus) includes a printing section  11  and a scanning section  12 . The printing section  11  is a device for recording an image on a sheet using an ink-jet recording method. The scanning section  12  is a device for scanning an image formed on a document and obtaining image information. In addition to the printing function of the printing section  11  and the scanning function of the scanning section  12 , the MFP  10  may have other functions such as a facsimile function. 
     Printing Section  11   
     As illustrated in  FIG. 1 , the printing section  11  includes a sheet-discharge tray  20 , a first conveyor  21 , a second conveyor  22 , an image recorder  23 , a platen  24 , the first supplier  14 , the second supplier  15 , and the third supplier  16 . The first supplier  14 , the second supplier  15 , and the third supplier  16  are arranged in this order from above. 
     Sheet-Discharge Tray  20   
     As illustrated in  FIG. 1 , the sheet-discharge tray  20  is disposed in a front portion of the printing section  11  to support a sheet with an image recorded by the image recorder  23 . 
     First Supplier  14 , Second Supplier  15 , and Third Supplier  16   
     As illustrated in  FIG. 1 , each of the first supplier  14 , the second supplier  15 , and the third supplier  16  is configured to store sheets and supply them one by one toward the image recorder  23 . The first supplier  14 , the second supplier  15 , and the third supplier  16  principally have the same configuration. Each of the first supplier  14 , the second supplier  15 , and the third supplier  16  includes a sheet-supply tray  17 , a sheet supplier  18 , and a separating plate  36 . Here, a common configuration of the first supplier  14 , the second supplier  15 , and the third supplier  16  will be explained, taking the first supplier  14  as one example. 
     Sheet-Supply Tray  17   
     As illustrated in  FIG. 1 , the sheet-supply tray  17  accommodates sheets stacked on each other. 
     Sheet Supplier  18   
     As illustrated in  FIG. 1 , the sheet supplier  18  includes a sheet-supply roller  25 , a sheet-supply arm  26 , and a shaft  27 . The sheet-supply roller  25  is rotatably supported at a distal end portion of the sheet-supply arm  26 . Forward rotation of the sheet-supply roller  25  is caused by a supply motor, not illustrated. The sheet-supply arm  26  is pivotably supported by the shaft  27  that is supported by a third frame  50  which will be described below. The sheet-supply arm  26  is urged by its own weight or an elastic force of an urging member such as a spring so as to pivot toward the first supplier  14 . The sheet supplier  18  of the second supplier  15  and the sheet supplier  18  of the third supplier  16  have the same configuration as that of the sheet supplier  18  of the first supplier  14 . 
     The forward rotation of the sheet-supply roller  25  is rotation that rotates the sheet-supply roller  25  such that the sheet-supply roller  25  supplies the sheet in a conveying direction  19 . In the following description, the forward rotation also indicates rotation for conveying the sheet in the conveying direction  19 , for rollers other than the sheet-supply roller  25 . 
     Separating Plate  36   
     As illustrated in  FIGS. 1 and 2 , the separating plate  36  is located at a rear of the sheet supplier  18 . A front surface of the separating plate  36  is flush with a third guide surface  86  of a third guide member  59  which will be described below and inclined with respect to the front and rear direction  8 . A plurality of separating pieces  36   a  (see  FIG. 6 ) protrude from the front surface of the separating plate  36 . The separating pieces  36   a  are arranged in the up and down direction  7 . 
     When the sheet-supply roller  25  of the sheet supplier  18  applies a force to an uppermost one of the sheets on the sheet-supply tray  17  in the conveying direction  19 , the sheets on the sheet-supply tray  17  are pressed against the separating plate  36 . As a result, an edge of each of the sheets enters in between corresponding two of the separating pieces  36   a  protruding from the separating plate  36 , making it impossible for the sheets to move in the up and down direction  7 . When a force is further applied to the uppermost sheet in the conveying direction  19 , the uppermost sheet is separated from the other sheets and supplied along a first conveyance path  41 . In the manner described above, the sheet supplier  18  of the first supplier  14  cooperates with the separating plate  36  to supply each of the sheets stacked on the sheet-supply tray  17 , toward the first conveyance path  41 . 
     First Conveyance Path  41 , Second Conveyance Path  42 , and Third Conveyance Path  43   
     As illustrated in  FIG. 1 , the printing section  11  includes the first conveyance path  41 , a second conveyance path  42 , and a third conveyance path  43  as paths through which the sheet is conveyed. The first conveyance path  41  extends upward from a rear end portion of the first supplier  14 , makes an upward U-turn so as to extend frontward, and extends to the sheet-discharge tray  20  via a space formed between the image recorder  23  and the platen  24 . The second conveyance path  42  extends upward from a rear end portion of the second supplier  15 , makes an upward U-turn so as to extend frontward, merges with the first conveyance path  41 , and extends to the sheet-discharge tray  20  via the space formed between the image recorder  23  and the platen  24 . The third conveyance path  43  extends upward from the rear end portion of the third supplier  16 , merges with the second conveyance path  42 , makes an upward U-turn so as to extend frontward, and extends to the sheet-discharge tray  20  via the space formed between the image recorder  23  and the platen  24 . The conveying direction  19  is indicated by the arrows illustrated along the first conveyance path  41 , the second conveyance path  42 , and the third conveyance path  43 . 
     As illustrated in  FIG. 1 , the printing section  11  includes an inner guide member  28 , an intermediate guide member  29 , and an outer guide member  30 . The inner guide member  28 , the intermediate guide member  29 , and the outer guide member  30  are arranged in this order from a front side toward a rear side. The U-turn portion of the first conveyance path  41  is formed between the inner guide member  28  and the intermediate guide member  29 . The U-turn portion of the second conveyance path  42  is formed between the intermediate guide member  29  and the outer guide member  30 . 
     First Conveyor  21  and Second Conveyor  22   
     As illustrated in  FIG. 1 , the first conveyor  21  is located upstream of the image recorder  23  in the conveying direction  19 . The first conveyor  21  includes a conveying roller  31  and a pinch roller  32  opposed to each other. The pinch roller  32  is located under the conveying roller  31 . The conveying roller  31  is driven by a conveying motor, not illustrated. The pinch roller  32  is rotated by rotation of the conveying roller  31 . The sheet nipped by the conveying roller  31  and the pinch roller  32  is conveyed in the conveying direction  19  by the conveying roller  31  and the pinch roller  32  rotating forwardly. 
     The second conveyor  22  is located downstream of the image recorder  23  in the conveying direction  19 . The second conveyor  22  includes a sheet-discharge roller  34  and a spur  35  opposed to each other. The spur  35  is located over the sheet-discharge roller  34 . The sheet-discharge roller  34  is driven by the conveying motor, not illustrated. The spur  35  is rotated by rotation of the sheet-discharge roller  34 . The sheet nipped by the sheet-discharge roller  34  and the spur  35  is conveyed in the conveying direction  19  by the sheet-discharge roller  34  and the spur  35  rotating forwardly. 
     Image Recorder  23   
     As illustrated in  FIG. 1 , the image recorder  23  is disposed between the first conveyor  21  and the second conveyor  22  in the conveying direction  19 . The image recorder  23  includes a carriage  38  and a recording head  39 . The carriage  38  is reciprocated in a main scanning direction (coinciding with the right and left direction  9  in the present embodiment). 
     The carriage  38  is mounted on the recording head  39 . A lower surface of the recording head  39  has a multiplicity of nozzles. Distal ends of the nozzles are exposed from the lower surface of the recording head  39 . The recording head  39  ejects fine ink droplets from the nozzles. During movement of the carriage  38  in the main scanning direction, the recording head  39  ejects the ink droplets toward the sheet supported on the platen  24 . As a result, an image is recorded on the sheet. 
     Platen  24   
     As illustrated in  FIG. 1 , the platen  24  is disposed between the first conveyor  21  and the second conveyor  22  in the conveying direction  19 . The image recorder  23  and the platen  24  are opposed to each other in the up and down direction  7 . The image recorder  23  is located above the platen  24 . The platen  24  supports a lower surface of the sheet conveyed by the first conveyor  21 . 
     Third Supplier  16   
     There will be described the configuration of the third supplier  16  in detail with reference to  FIGS. 2-8 . As illustrated in  FIG. 2 , the third supplier  16  includes a main body portion  44  and the sheet-supply tray  17  supported by the main body portion  44  so as to be insertable and removable in the front and rear direction  8 . 
     Main Body Portion  44   
     As illustrated in  FIGS. 2-4 , the main body portion  44  includes a casing  45 , a right frame  46 , a left frame  47 , a first frame  48 , a second frame  49 , the third frame  50 , a first guide member  51 , a second guide member  52 , a rotation shaft  53 , four conveying rollers  54 , four driven rollers  55 , a detector  58 , and the third guide member  59 . As illustrated in  FIG. 6 , the main body portion  44  includes four support shafts  56  and eight springs  57 . 
     Casing  45   
     As illustrated in  FIGS. 2-4 , the casing  45  includes a bottom wall  60 , a rear wall  61 , a right box  62 , and a left box  63 . The bottom wall  60  is located at a central portion of the casing  45  in the right and left direction  9  and shaped like a plate extending in the front and rear direction  8 . The rear wall  61  extends upward from a rear end portion of the bottom wall  60 . The right box  62  is located to the right of the bottom wall  60  and shaped like a box opening upward. The right box  62  includes a right inner wall  64  and a right outer wall  65  opposed to each other in the right and left direction  9 . An accommodating chamber is formed between the right inner wall  64  and the right outer wall  65 . The right outer wall  65  is located farther from the bottom wall  60  than the right inner wall  64 . The accommodating chamber of the right box  62  accommodates a drive mechanism relating to driving of the sheet supplier  18 . The left box  63  is located to the left of the bottom wall  60  and shaped like a box opening upward. The left box  63  includes a left inner wall  66  and a left outer wall  67  opposed to each other in the right and left direction  9 . An accommodating chamber is formed between the left inner wall  66  and the left outer wall  67 . The left outer wall  67  is located farther from the bottom wall  60  than the left inner wall  66 . The bottom wall  60 , the rear wall  61 , the right box  62 , and the left box  63  are formed of resin and formed integrally with each other or fixed to each other. The right box  62  and the left box  63  accommodate the drive mechanism relating to driving of the sheet supplier  18 . 
     Right Frame  46  and Left Frame  47   
     As illustrated in  FIGS. 2-4 , the right frame  46  (as one example of a supporter and a support member) and the left frame  47  (as another example of the supporter and the support member) support the first frame  48 , the second frame  49 , and the rotation shaft  53 . The right frame  46  and the left frame  47  are coupled to the casing  45 . The right frame  46  is secured to a right surface of the right inner wall  64  of the right box  62  by screws, for example. The left frame  47  is secured to a left surface of the left inner wall  66  of the left box  63  by screws, for example. In the present embodiment, each of the right frame  46  and the left frame  47  is constituted by a bent metal plate. The right frame  46  is located at a rear portion of the right box  62  in the front and rear direction  8 . The left frame  47  is located at a rear portion of the left box  63  in the front and rear direction  8 . 
     First Frame  48   
     As illustrated in  FIGS. 2-4 , the first frame  48  is elongated in the right and left direction  9  and supports the first guide member  51 . The first frame  48  is constituted by a bent metal plate in the present embodiment. The first frame  48  is located at a central portion of the right frame  46  and a front end portion of the left frame  47 . The first frame  48  is coupled to the right frame  46  and the left frame  47 . Right and left end portions of the first frame  48  are respectively secured to the right frame  46  and the left frame  47  by screws, for example. 
     Second Frame  49   
     As illustrated in  FIGS. 2-4 , the second frame  49  is elongated in the right and left direction  9  and supports the second guide member  52 . The second frame  49  is constituted by a bent metal plate in the present embodiment. The second frame  49  is located at rear end portions of the right frame  46  and the left frame  47 . The second frame  49  is coupled to the right frame  46  and the left frame  47 . Right and left end portions of the second frame  49  are respectively secured to the right frame  46  and the left frame  47  by screws, for example. 
     Third Frame  50   
     As illustrated in  FIGS. 2-4 , the third frame  50  is elongated in the right and left direction  9  and supports the sheet supplier  18 . The shaft  27  of the sheet supplier  18  is rotatably supported by the third frame  50 . The sheet-supply arm  26  of the sheet supplier  18  extends to an area located at a rear of the third frame  50 . The sheet-supply roller  25  is provided at a rear end portion of the sheet-supply arm  26 , i.e., one of opposite end portions of the sheet-supply arm  26 , which one is farther from the shaft  27  supported by the third frame  50  than the other end portion. The third frame  50  is constituted by a bent metal plate in the present embodiment. The third frame  50  is located at generally the center of each of the right box  62  and the left box  63  in the front and rear direction  8 . The third frame  50  is coupled to the right frame  46  and the left box  63 . Right and left end portions of the third frame  50  are respectively secured to central portions of a front end portion of the right frame  46  and the left inner wall  66  of the left box  63  by screws, for example. 
     First Guide Member  51   
     As illustrated in  FIGS. 3-7 , the first guide member  51  extends in the right and left direction  9 . The first guide member  51  is formed of resin in the present embodiment. An upper surface of the first guide member  51  is in contact with a lower surface of the first frame  48 . The first guide member  51  is secured to the first frame  48  by screws, for example. 
     As illustrated in  FIG. 5 , the first guide member  51  is located over a rear end portion of the sheet-supply tray  17 . As illustrated in  FIGS. 3-7 , the first guide member  51  includes a first guide main body  68  and six first engaging portions  72 . The first guide main body  68  includes two first guide surfaces  70  and four fourth guide surfaces  71 . As illustrated in  FIGS. 7 and 8 , the outer shape of the first guide main body  68  is a dome shape expanded downward when the first guide main body  68  is viewed in the right and left direction  9 . The first guide surfaces  70  are formed on a lower surface of a rear portion of the first guide main body  68  and a rear surface of the first guide main body  68 . The fourth guide surfaces  71  are formed on a front portion of a lower surface of the first guide main body  68 . 
     As illustrated in  FIG. 6 , the first guide surfaces  70  guide the sheet supplied by the sheet supplier  18  and partly define the third conveyance path  43 . The first guide surfaces  70  curve upward while extending rearward. Each of the first guide surfaces  70  has an arc-shape when viewed in the right and left direction  9 . 
     The third conveyance path  43  in the third supplier  16  curves upward while extending rearward. The first guide surfaces  70  are located on an inner side of the third conveyance path  43 . That is, the first guide surfaces  70  are located on one of opposite sides of the third conveyance path  43 , which one is nearer to the center of the curvature of the third conveyance path  43  than the other. 
     As illustrated in  FIGS. 5 and 6 , the fourth guide surfaces  71  are located on an upper side of an upper surface  17   a  of the sheet-supply tray  17  and curved downward while extending rearward. Each of the fourth guide surfaces  71  has an arc-shape when viewed in the right and left direction  9 . A rear end of each of the fourth guide surfaces  71  is continuous to a front end of a corresponding one of the first guide surfaces  70 . 
     As illustrated in  FIGS. 3-7 , each of the first engaging portions  72  extends upward from an upper surface of a rear end portion of the first guide main body  68  and has an opening  72   a  facing upward. As illustrated in  FIG. 6 , each of the first engaging portions  72  has a U-shape when viewed in the right and left direction  9 . The rotation shaft  53  of the conveying rollers  54  is engaged in the first engaging portions  72 . That is, the first guide member  51  has recesses each opening upward and having a U-shape in cross section when viewed in the right and left direction  9 , and the rotation shaft  53  in inserted in the recesses. A surface of the rotation shaft  53  engaged in the first engaging portions  72  is partly exposed from the openings  72   a.    
       FIGS. 3, 4, and 7 , the six first engaging portions  72  are arranged in the right and left direction  9 . The six first engaging portions  72  are located between the right frame  46  and the left frame  47  in the right and left direction  9 . 
     Second Guide Member  52   
     As illustrated in  FIGS. 3-6 and 8 , the second guide member  52  extends in the right and left direction  9 . The second guide member  52  is formed of resin in the present embodiment. A lower surface of the second guide member  52  is in contact with an upper surface of the second frame  49 . The second guide member  52  is secured to the second frame  49  by screws, for example. 
     As illustrated in  FIGS. 5 and 6 , the second guide member  52  is located over the rear wall  61  of the casing  45  and extends from the rear wall  61  in an upper and front direction. As illustrated in  FIGS. 3-6 and 8 , the second guide member  52  includes a second guide main body  69  and two second engaging portions  74 . The second guide main body  69  has two second guide surfaces  73 . As illustrated in  FIGS. 7 and 8 , the outer shape of the second guide main body  69  is a trapezoid shape when the second guide main body  69  is viewed in the right and left direction  9 . The second guide surfaces  73  are formed on a front surface of the second guide main body  69 . 
     As illustrated in  FIG. 6 , the second guide surfaces  73  guide the sheet supplied by the sheet supplier  18  and partly define the third conveyance path  43 . The second guide surfaces  73  are respectively opposed to the first guide surfaces  70 . Each of the second guide surfaces  73  is a flat surface inclined with respect to the front and rear direction  8  (as one example of the horizontal direction). That is, each of the second guide surfaces  73  is a flat surface inclined with respect to the horizontal plane. The second guide surfaces  73  are located on an outer side of the third conveyance path  43 . That is, the second guide surfaces  73  are located on the other of the opposite sides of the third conveyance path  43 , which is farther from the center of the curvature of the third conveyance path  43  than the one of the opposite sides. 
     As illustrated in  FIGS. 3, 4, and 8 , each of the second engaging portions  74  extends upward from an upper surface of a front end portion of the second guide main body  69  and has an opening  74   a  facing upward. As illustrated in  FIGS. 3 and 8 , each of the second engaging portions  74  has a U-shape when viewed in the right and left direction  9 . The rotation shaft  53  of the conveying rollers  54  is engaged in the second engaging portions  74 . That is, the second guide member  52  has recesses each opening upward and having a U-shape in cross section when viewed in the right and left direction  9 , and the rotation shaft  53  in inserted in the recesses. A surface of the rotation shaft  53  engaged in the second engaging portions  74  is partly exposed from the openings  74   a . As illustrated in  FIG. 2 , the rotation shaft  53  is engaged with the first engaging portions  72  and the second engaging portions  74 . Inner surfaces of the respective first engaging portions  72  and inner surfaces of the respective second engaging portions  74  are located on a surface of an imaginary circular cylinder extending along the axial direction of the rotation shaft  53 . 
     As illustrated in  FIGS. 3, 4, and 8 , the two second engaging portions  74  are arranged along the right and left direction  9 . The two second engaging portions  74  are located between the right frame  46  and the left frame  47  in the right and left direction  9 . As illustrated in  FIG. 2 , the two second engaging portions  74  are located outside a widthwise region  43   a  of the third conveyance path  43 . The widthwise region  43   a  is a region of the third conveyance path  43  in the right and left direction  9 . The widthwise region  43   a  in the right and left direction  9  is slightly wider in the right and left direction  9  than a sheet having the largest width among the sheets conveyable in the printing section  11 . That is, during conveyance of the sheet having the largest width in the right and left direction  9  (the widthwise direction) among the sheets conveyable through the third conveyance path  43 , the two second engaging portions  74  are located not within a region between opposite edges of the sheet in the right and left direction  9  but outside the region between the opposite edges of the sheet in the right and left direction  9 . Also, the six first engaging portions  72  are located between the two second engaging portions  74  in the right and left direction  9 . 
     Rotation Shaft  53   
     As illustrated in  FIGS. 3-6 and 8 , the rotation shaft  53  is a shaft member extending in the right and left direction  9 . As illustrated in  FIGS. 3 and 4 , two bearings  75  are respectively provided on opposite end portions of the rotation shaft  53 . The bearings  75  support the rotation shaft  53  such that the rotation shaft  53  is rotatable. The bearing  75  are respectively fixed to the right frame  46  and the left frame  47 . A drive gear  76  is fixed to a right end portion of the rotation shaft  53 . The drive gear  76  receives a driving force from a motor, not illustrated, and rotates the rotation shaft  53 . 
     The first engaging portions  72  of the first guide member  51  and the second engaging portions  74  of the second guide member  52  are engaged with the rotation shaft  53 . The rotation shaft  53  is rotatably supported not only by the right frame  46  and the left frame  47  but also by the first guide member  51  and the second guide member  52 . 
     Conveying Rollers  54   
     As illustrated in  FIGS. 3-6 and 8 , the four conveying rollers  54  are fixed to the rotation shaft  53 . The four conveying rollers  54  are spaced apart from each other in the axial direction of the rotation shaft  53 . When the rotation shaft  53  is driven, the four conveying rollers  54  are rotated. 
     As illustrated in  FIGS. 3 and 4 , each of four of the six first engaging portions  72  of the first guide member  51  is located between corresponding adjacent two of the conveying rollers  54 . The other two first engaging portions  72  are located outside of the four conveying rollers  54  in the right and left direction  9 . 
     Driven Rollers  55   
     As illustrated in  FIGS. 3, 4, and 8 , the four driven rollers  55  are respectively opposed to the four conveying rollers  54 . 
     Support Shafts  56  and Springs  57   
     As illustrated in  FIGS. 6 and 8 , the support shafts  56  (each as one example of a roller supporter) and the springs  57  (each as one example of an urging member) are provided on the second guide member  52 . The main body portion  44  includes the four support shafts  56 . The driven rollers  55  are rotatably supported by the respective support shafts  56 . As illustrated in  FIG. 8 , the second guide member  52  has four recessed portions  77  opening upward. The driven rollers  55  are provided in the respective recessed portions  77 . As illustrated in  FIG. 6 , the second guide member  52  has spring chambers  78  each accommodating an end portion of a corresponding one of the support shafts  56  and a corresponding one of the springs  57 . As illustrated in  FIG. 8 , each of the spring chambers  78  extends rearward and has an elongated hole  79  formed in a side wall of a corresponding one of the recessed portions  77 . Two of the elongated holes  79  are formed in opposite side walls defining a corresponding one of the recessed portions  77 . Two of the spring chambers  78  are respectively located on right and left sides of a corresponding one of the recessed portions  77 . A closing member  80  closing rear portions of the spring chambers  78  is fixed to the second guide member  52 . 
     In each of the spring chambers  78 , as illustrated in  FIG. 6 , the support shaft  56  is located at a front portion of the spring chamber  78 , and the spring  57  is located between the support shafts  56  and the closing member  80 . A direction connecting between the axis of the rotation shaft  53  of the conveying rollers  54  and the axis of the support shafts  56  of the driven rollers  55  when the rotation shaft  53  and the support shafts  56  are viewed in the right and left direction  9  is an opposed direction  81  in which the conveying rollers  54  and the driven rollers  55  are opposed to each other. The longitudinal direction of each of the elongated holes  79  formed in the second guide member  52  substantially coincides with the opposed direction  81 . Thus, the driven rollers  55  are urged by the respective springs  57  toward the respective conveying rollers  54  in the opposed direction  81  and movable away from the respective conveying rollers  54  along the respective elongated holes  79 . The support shafts  56  rotatably supporting the respective driven rollers  55  are supported movably with respect to the second guide member  52 . Thus, the driven rollers  55  are rotatably supported by the second guide member  52 . 
     The opposed direction  81  is a direction orthogonal to the right and left direction  9  and inclined with respect to the front and rear direction  8  and the up and down direction  7 . The opposed direction  81  includes a lower front direction and an upper rear direction. The openings  72   a  of the first engaging portions  72  and the openings  74   a  of the second engaging portions  74  are oriented in the up direction, i.e., a direction not coinciding with the opposed direction  81 . 
     As illustrated in  FIGS. 2 and 8 , the driven rollers  55  are urged by the respective springs  57  so as to contact the respective conveying rollers  54 , and accordingly each of the driven rollers  55  and a corresponding one of the conveying rollers  54  cooperate with each other to nip and convey the sheet at a nip position P 1 . The nip position P 1  is a position at which the conveying roller  54  and the driven roller  55  are in contact with each other. 
     Detector  58   
     As illustrated in  FIGS. 2-4 and 7 , the detector  58  is provided on the first guide member  51 . As illustrated in  FIG. 7 , the detector  58  includes a contact arm  82 , an arm shaft  83 , a detection arm  84 , and an optical sensor  85 . The contact arm  82  is protrutable in the third conveyance path  43 . The arm shaft  83  is rotatably supported by the upper surface of the first guide member  51 . The axial direction of the arm shaft  83  coincides with the right and left direction  9 . The contact arm  82  is fixed to one end of the arm shaft  83 , and the detection arm  84  is fixed to the other end of the arm shaft  83 . Each of the contact arm  82  and the detection arm  84  extends from the arm shaft  83  in a direction orthogonal to the axial direction of the arm shaft  83 . The direction in which the contact arm  82  extends is different from the direction in which the detection arm  84  extends. The optical sensor  85  includes a light emitter and a light receiver. The detection arm  84  pivotable about the axis of the arm shaft  83  is capable of intercepting a light path extending from the light emitter to the light receiver of the optical sensor  85 . 
     The contact arm  82  protrudes in the third conveyance path  43  by its own weight in a state in which no sheet is present in the third conveyance path  43 . When the contact arm  82  is located at a lower position, the detection arm  84  is located at an upper position. In this state, the detection arm  84  does not intercept the light path formed by the optical sensor  85 . In a state in which a sheet is present in the third conveyance path  43 , the contact arm  82  is pressed by the sheet and located at an upper position. When the contact arm  82  is located at the upper position, the detection arm  84  is located at a lower position. In this state, the detection arm  84  intercepts the light path formed by the optical sensor  85 . Thus, the light path formed by the optical sensor  85  is maintained or intercepted, depending upon the presence or absence of the sheet in the third conveyance path  43 . That is, the optical sensor  85  is capable of outputting a signal indicating the presence or absence of the sheet. 
     As illustrated in  FIGS. 3, 4, and 7 , the contact arm  82  is located at a central portion of the first guide member  51  in the up and down direction  7  and the front and rear direction  8 . The rotation shaft  53  of the conveying rollers  54  is located at an upper rear end portion of the first guide member  51 . The contact arm  82  is located in the third conveyance path  43  at a position located upstream of the nip position P 1  (at which the conveying rollers  54  and the driven rollers  55  nip the sheet) in the conveying direction  19 . Accordingly, the presence or absence of the sheet is detected by the detector  58  in the third conveyance path  43  at a position located upstream of the nip position P 1  in the conveying direction  19 . 
     Third Guide Member  59   
     As illustrated in  FIGS. 3-6 , the third guide member  59  is fixed to the bottom wall  60  and the rear wall  61 . The third guide member  59  has the third guide surface  86  partly defining the third conveyance path  43 . The third guide surface  86  guides the sheet supplied by the sheet-supply roller  25 , toward the first guide member  51  and the second guide member  52 . 
     As illustrated in  FIG. 6 , when viewed in the right and left direction  9 , the third guide surface  86  is an inclined surface intersecting the front and rear direction  8 . That is, the third guide surface  86  is an inclined surface intersecting the horizontal plane. When viewed in the up and down direction  7 , the third guide surface  86  may be any of a flat surface and a curved surface protruding frontward. An imaginary line  87  is a straight line extending through a position that is a position located on the third guide surface  86  in the right and left direction  9 . The imaginary line  87  is included in a vertical plane orthogonal to the right and left direction  9 . The imaginary line  87  is inclined with respect to the front and rear direction  8  and the up and down direction  7 . The imaginary line  87  extends from the third guide surface  86  toward the first guide member  51  and the second guide member  52 . The imaginary line  87  extends through a position that is located between one of the first guide surfaces  70  and a corresponding one of the second guide surfaces  73  in the opposed direction  81 . 
     As illustrated in  FIG. 6 , the third guide surface  86  of the third guide member  59  is located in front of the second guide surfaces  73  of the second guide member  52 . The third guide surface  86  is not continuous to the second guide surfaces  73 . Thus, a step in the front and rear direction  8  is formed between the third guide surface  86  and the second guide surfaces  73 . An obtuse angle θ 2  at which the second guide surfaces  73  intersect the front and rear direction  8  is substantially equal to an obtuse angle θ 3  at which the third guide surface  86  intersects the front and rear direction  8 . That is, the obtuse angle θ 2  at which the second guide surfaces  73  intersect the horizontal plane is substantially equal to the obtuse angle θ 3  at which the third guide surface  86  intersects the horizontal plane. 
     Effects 
     In the MFP  10  according to the present embodiment, the first guide member  51  and the second guide member  52  are engaged with the rotation shaft  53  fixed to the conveying rollers  54 . This keeps a positional relationship between each of the first guide surfaces  70  of the first guide member  51  and the corresponding second guide surface  73  of the second guide member  52 . The position of the sheet guided by the first guide surfaces  70  and the second guide surfaces  73  does not change, whereby the sheet is appropriately conveyed to the nip position P 1  at which the sheet is nipped by the conveying rollers  54  and the driven rollers  55 . 
     Since the driven rollers  55  are supported by the second guide member  52 , the nip position P 1  at which the sheet is nipped by the conveying rollers  54  supported by the first guide member  51  and the driven rollers  55  supported by the second guide member  52  is positioned and does not change. This keeps a positional relationship among the first guide surfaces  70 , the second guide surfaces  73 , and the nip position P 1 . The sheet guided by the first guide surfaces  70  and the second guide surfaces  73  is appropriately guided to the nip position P 1  without positioning the first guide surfaces  70  and the second guide surfaces  73  and positioning the nip position P 1 , individually. Also, this configuration stabilizes the nipping force of the conveying rollers  54  and the driven rollers  55 . Thus, the sheet is held by the conveying rollers  54  without separated from the conveying rollers  54 , so that the sheet is conveyed to a downstream side in the conveying direction  19  by the conveying rollers  54 . 
     The openings  72   a  of the first engaging portions  72  and the openings  74   a  of the second engaging portions  74  are not oriented in the opposed direction  81 . Thus, even when a force is applied to the rotation shaft  53  in a direction in which the conveying rollers  54  and the driven rollers  55  are moved toward and away from each other, the rotation shaft  53  is not easily separated from the first engaging portions  72  and the second engaging portions  74 . 
     The second engaging portions  74  are located outside the conveying rollers  54  and the third conveyance path  43  in the axial direction of the rotation shaft  53 , thereby preventing the second engaging portions  74  from interfering with the third conveyance path  43 . 
     The detector  58  is supported by the first guide member  51 . Thus, the detector  58  is positioned with respect to the first guide member  51 . Accordingly, when compared with a case where the detector  58  is not positioned with respect to the first guide member  51 , it is possible to prevent reduction in accuracy of detection of the sheet by the detector  58 . 
     The imaginary line  87  included in the third guide surface  86  extends through a position located between the first guide surfaces  70  and the second guide surfaces  73 . Thus, the sheet supplied from the sheet-supply roller  25  in the conveying direction is not caught by the second guide member  52  when guided from the third guide surface  86  to the second guide surfaces  73 . This configuration prevents a jam of the sheet caught by the second guide member  52 . 
     The obtuse angle θ 2  at which the second guide surfaces  73  intersect the horizontal direction is substantially equal to the obtuse angle θ 3  at which the third guide surface  86  intersects the horizontal direction. Thus, the sheet conveyed by the sheet-supply roller  25  and guided along the third guide surface  86  is guided along the second guide surfaces  73  connected to the third guide surface  86 , without being pushed toward the first guide surfaces  70  opposed to the third guide surface  86  with the third conveyance path  43  therebetween. This configuration reduces the jam of the sheet when compared with a case where the sheet is guided from the third guide surface  86  to the first guide surfaces  70  and brought into contact with the first guide surfaces  70 . 
     The fourth guide surfaces  71  located on an upper side of the upper surface  17   a  of the sheet-supply tray  17  extend toward the first guide surfaces  70 . Thus, even in the case where the sheet-supply tray  17  is filled with the sheets, and an uppermost one of the sheets is in contact with the fourth guide surfaces  71 , the sheet is supplied in the conveying direction without hindered by the first guide member  51 . 
     The first frame  48  supporting the first guide member  51  and the second frame  49  supporting the second guide member  52  are coupled to the right frame  46  and the left frame  47 . Thus, the first guide member  51  and the second guide member  52  are positioned accurately. The first guide member  51  and the second guide member  52  are engaged with the rotation shaft  53  of the conveying rollers  54 , thereby accurately positioning the rotation shaft  53 , the first guide member  51 , and the second guide member  52  to each other. 
     The third frame  50  supporting the sheet-supply roller  25  rotatably via the sheet-supply arm  26  and the shaft  27  is coupled to the right frame  46  and the left frame  47 . Thus, the sheet-supply roller  25  supported by the third frame  50  is accurately positioned with respect to the conveying rollers  54  supported by the right frame  46  and the left frame  47  via the first guide member  51  and the rotation shaft  53 . 
     The driven rollers  55  are urged toward the respective conveying rollers  54 . Thus, the sheet is appropriately held at the nip position P 1  without separating from the conveying rollers  54 . 
     Modifications 
     In the MFP  10  according to the present embodiment, the first engaging portions  72  engaged with the rotation shaft  53  have the respective openings  72   a , and the second engaging portions  74  engaged with the rotation shaft  53  have the respective openings  74   a , but the present disclosure is not limited to this configuration. Each of the first engaging portions  72  and the second engaging portions  74  engaged with the rotation shaft  53  may be an annular bearing that supports the rotation shaft  53  rotatably. 
     In the present embodiment, the openings  72   a  of the first engaging portions  72  and the openings  74   a  of the second engaging portions  74  are oriented upward and are not oriented in the opposed direction  81  in which the conveying rollers  54  and the driven rollers  55  are opposed to each other, but the orientation of the respective openings  72   a ,  74   a  is not limited to this orientation. The orientation of the openings  72   a ,  74   a  may be any direction unless the orientation is the opposed direction  81 . 
     While the first guide member is located on an inner side of the curved third conveyance path  43 , and the second guide member  52  supporting the driven rollers  55  is located on an outer side of the curved third conveyance path  43  in the present embodiment, the MFP  10  may be configured such that the first guide member is located on an outer side of the third conveyance path  43 , and the second guide member  52  is located on an inner side of the third conveyance path  43 . 
     The detector  58  is supported by the first guide member  51  in the present embodiment and may be supported by the second guide member  52 , or another frame or member in the MFP  10 . 
     While the third guide member  59  configured to guide the sheet toward the first guide member  51  and the second guide member  52  has the third guide surface  86  as the inclined surface in the present embodiment, the third guide surface  86  at least needs to be a surface defining the third conveyance path  43 . The third guide surface  86  may be a curved surface curved upward while extending rearward and having an arc-shape protruding rearward and downward when viewed in the right and left direction  9 . In this case, a tangent to an upper end of the third guide surface  86  when viewed in the right and left direction  9  passes through a position that is located between a corresponding one of the first guide surfaces  70  and the corresponding second guide surface  73  in the opposed direction  81 . 
     While the obtuse angle θ 2  at which the second guide surfaces  73  intersect the horizontal direction is substantially equal to the obtuse angle θ 3  at which the third guide surface  86  intersects the horizontal direction in the present embodiment, the obtuse angle θ 2  of the second guide surfaces  73  may be different from the obtuse angle θ 3  of the third guide surface  86 . 
     The first guide member  51  has the fourth guide surfaces  71  located above the upper surface  17   a  of the sheet-supply tray  17  in the present embodiment but need not have the fourth guide surfaces  71 . 
     In the present embodiment, the first frame  48  supporting the first guide member  51 , the second frame  49  supporting the second guide member  52 , and the third frame  50  supporting the sheet-supply roller  25  are coupled to the right frame  46  and the left frame  47 , but the present disclosure is not limited to this configuration. The first frame  48 , the second frame  49 , and the third frame  50  may be directly or indirectly secured to the casing  45  and need not be directly coupled to the right frame  46  and the left frame  47 .