Patent Publication Number: US-9403384-B2

Title: Recording apparatus

Description:
BACKGROUND 
     1. Technical Field 
     The present invention relates to a recording apparatus represented by a facsimile, a printer, or the like. 
     2. Related Art 
     A recording apparatus represented by a facsimile or a printer, particularly a serial-type recording apparatus that performs recording while the carriage provided with a recording head moves in a predetermined direction may be configured so that an optical sensor configured from a light emitting unit and a light receiving unit is provided on a carriage, the presence of a sheet or the edge position of the sheet is detected based on the intensity of light that the light receiving unit has received (for example, JP-A-2006-272711). 
     In recent years, there is demand for further size reductions of printers. In particular, for mobile-type printers which are assumed to be carried by a user, there is demand for still further size reductions. 
     When focusing on the horizontal width dimensions of the printer, the horizontal width dimensions are generally determined by the width of the movement region of the carriage. The width of the movement region of the carriage is influenced by the operation width for the carriage necessary for detecting the side edge of the sheet by the optical sensor, in addition to the sheet width. 
     In the recording apparatus disclosed in the above-described JP-A-2006-272711 or another recording apparatus of the related art, even though the apparatus is configured so as to detect the sheet edge with an optical sensor, the arrangement of the optical sensor is not devised from the viewpoint of size reductions. 
     SUMMARY 
     An advantage of some aspects of the invention is to provide a recording apparatus configured to detect the sheet edge position taking size reductions of the apparatus into account. 
     According to a first aspect of the invention, there is provided a recording apparatus including a carriage that includes a recording head performing recording on a recording medium, and an edge detection unit detecting an edge of the recording medium, and is movable in a predetermined direction, in which, in a state in which the carriage is positioned at a predetermined position, the edge detection unit is positioned in a passing region of the recording medium in the movement direction of the carriage, and the predetermined position is a home position of the carriage. 
     In this case, since the edge detection unit is positioned within the passing region of the recording medium in the movement direction of the carriage in a state in which the carriage is positioned at the predetermined position, that is, the home position, the home position of the carriage is near (close to) the passing region of the recording medium. Accordingly, the horizontal width dimension (dimension in the movement direction of the carriage) of the apparatus is suppressed, and it is possible for the size of the apparatus to be reduced. 
     According to a second aspect of the invention, there is provided a recording apparatus including a carriage that includes a recording head performing recording on a recording medium, and an edge detection unit detecting an edge of the recording medium, and is movable in a predetermined direction; and a cap unit that caps the recording head and is provided outside a passing region of the recording medium in the movement direction of the carriage, in which in a state in which the carriage is positioned at a predetermined position, the edge detection unit is positioned in the passing region of the recording medium in the movement direction of the carriage, and the predetermined position is a position at which the recording head is capped by the cap unit. 
     In this case, since the edge detection unit is positioned within the passing region of the recording medium in the movement direction of the carriage in a state in which the carriage is positioned at the predetermined position, that is, the position (below, referred to as a capping position) at which the head is capped by the capping unit, the capping position of the carriage is near (close to) the passing region of the recording medium. Accordingly, the horizontal width dimension (dimension in the movement direction of the carriage) of the apparatus is suppressed, and it is possible for the size of the apparatus to be reduced. 
     According to a third aspect of the invention, there is provided a recording apparatus including a carriage that includes a recording head performing recording on a recording medium, and an edge detection unit detecting an edge of the recording medium, and is movable in a predetermined direction, in which, in a state in which the carriage is positioned at a predetermined position, the edge detection unit is positioned in a passing region of the recording medium in the movement direction of the carriage, and the predetermined position is an end portion position on one side of the movable region of the carriage. 
     In this case, since the edge detection unit is positioned within the passing region of the recording medium in the movement direction of the carriage, in a state in which the carriage is positioned at the predetermined position, that is, the end portion position on one side of the region in which the carriage is movable, the end portion position on one side of the movable range of the carriage is near (close to) the passing region of the recording medium. Accordingly, the horizontal width dimension (dimension in the movement direction of the carriage) of the apparatus is suppressed, and it is possible for the size of the apparatus to be reduced. 
     According to a fourth aspect of the invention, it is preferable that the recording apparatus further includes a transport unit that transports the recording medium; and a control unit that controls the transport unit and the carriage, in which the control unit is able to execute a leading edge detection mode for detecting a leading edge of the recording medium by transporting the recording medium until the leading edge of the recording medium passes through a position facing the edge detection unit, in a state in which the carriage is stopped at the predetermined position during leading edge-positioning of the recording medium. 
     In this case, since the control unit that controls the transport unit and the carriage is able to execute the leading edge detection mode that detects the leading edge of the recording medium by transporting the recording medium until the leading edge of the recording medium passes through the position facing the edge detection unit in a state in which the carriage is stopped at the predetermined position during leading edge-positioning of the recording medium, it is possible to detect passing of the leading edge of the recording medium with the carriage stopped at the predetermined position, and it is possible for lowering of the recording throughput to be suppressed without the carriage being moved from the predetermined position to the detection position. 
     According to a fifth aspect of the invention, it is preferable that the control unit, in a case where the leading edge detection mode is executed, does not execute borderless recording that performs recording without white space on the end portion of the recording medium. 
     In this case, since the control unit does not execute the borderless recording that performs recording without white space on the end portion of the recording medium in a case where the leading edge detection mode is executed, even in cases where only the side edge of one side of the recording medium is detected, or not detected, it is possible for a suitable recording quality to be secured. 
     According to a sixth aspect of the invention, it is preferable that, after the leading edge detection mode is executed, the control unit executes a side edge detection mode for detecting the side edge of one side of the recording medium by the carriage being moved to an opposite side to the predetermined position side until the edge detection unit is separated from the region of the recording medium. 
     In this case, since the control unit executes the side edge detection mode for detecting the side edge of one side of the recording medium by the carriage being moved to an opposite side to the predetermined position side until the edge detection unit is separated from the region of the recording medium after the leading edge detection mode is executed, it is possible for shifting of the recording position to be suppressed by detecting the side edge on the one side, and it is possible for better recording results to be obtained. 
     According to a seventh aspect of the invention, it is preferable that a signal line cable that connects the control unit and the recording head extends from the side surface of the carriage on the opposite side to the predetermined position side, and the control unit performs first recording on the recording medium with the recording head when the carriage is moved toward the predetermined position after execution of the side edge detection mode. 
     In a case where the signal line cable that connects the control unit and the recording head extends from the side surface of the carriage on the opposite side to the predetermined position side, if the carriage is positioned at the predetermined position, the signal line cable is positioned on a position above the transport region of the recording medium. Accordingly, in this case, it is difficult to perform jam processing tasks in a case in which a jam occurs in the transport path of the recording medium and there is concern of a breakdown occurring by the user touching the signal line cable. Meanwhile, when the carriage is positioned at the end portion on the opposite side (below, referred to as “opposite side end portion position”) to the predetermined position, the signal line cable retreats from the position above the transport region of the recording medium. 
     There is concern of the recording head coming into contact with the side edge of the recording medium as the side edge of the recording medium is bent upward and a jam arising as a result. That is, jams according to the movement of the carriage easily occur when the recording head moves from the outside of the recording medium to the inside during first recording on the recording medium. 
     In a case in which the first recording on the recording medium is performed when the carriage moves from the predetermined position to the opposite side end portion position, if a jam occurs during the recording, the carriage is able to perform only one of stopping at the position or returning to the predetermined position. Thus, because the signal line cable is positioned on the position above the transport region of the recording medium during jam processing tasks by the user, there is concern of the above-described problem arising. 
     However, the control unit performs first recording on the recording medium with the recording head when the carriage is moved (from the opposite side end portion position) to the predetermined position side after the side edge detection mode is executed. That is, since the first recording on the recording medium is performed during movement of the carriage from the opposite side end portion position to the predetermined position, it is possible for the above-described problem to be avoided. 
     According to an eighth aspect of the invention, it is preferable that the recording apparatus further includes a feeding portion that feeds the recording medium to the recording head side, in which the feeding portion includes a first edge guide that guides the side edge of the recording medium on the predetermined position side in a direction that intersects a feeding direction of the recording medium, and a second edge guide that guides the side edge of the recording medium on an opposite side to the predetermined position side, and in which the first edge guide is provided to be movable to the second edge guide side until the passing region of the recording medium is separated from the arrangement position of the edge detection unit in a state in which the carriage is positioned at the predetermined position. 
     In this case, since the first edge guide that guides the side edge of the recording medium on the predetermined position side is movable to the second edge guide side until the passing region of the recording medium is separated from the arrangement position of the edge detection unit in a state in which the carriage is positioned at the predetermined position, it is possible to detect the side edge of the recording medium on the predetermined position side with the edge detection unit through the first edge guide being moved. That is, since it is possible to detect the side edge on both sides of the recording medium, shifting of the recording position is more reliably suppressed, and it is possible for a better recording result to be obtained. In particular, during the borderless recording that performs recording without white space on the end portion of the recording medium, an excellent recording result is obtained with suppression of shifting of the recording position. 
     According to a ninth aspect of the invention, it is preferable that the second edge guide is provided to be able to advance and retreat with respect to the first edge guide, and the first edge guide is provided to be movable in accordance with a movement of the second edge guide in a direction toward the second edge guide with a predetermined guide position as a boundary when the second edge guide is moved toward the first edge guide side. 
     In this case, since the first edge guide moves in accordance with a movement of the second edge guide, the operability for the user is improved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements. 
         FIG. 1  is a perspective view illustrating the appearance of a printer according to the invention. 
         FIG. 2  is a side cross-sectional view showing a sheet transport path of the printer according to the invention. 
         FIG. 3  is a perspective view of the apparatus main body of the printer according to the invention. 
         FIG. 4  is a plan view of the apparatus main body of the printer according to the invention. 
         FIG. 5  is a perspective view of the lower surface of a carriage according to the invention. 
         FIG. 6  is a plan view showing a state in which the leading edge of the sheet is positioned on the upstream side of the edge detection unit in a sheet feeding state. 
         FIG. 7  is a drawing schematically showing the positional relationship between the edge guide, sheet, carriage, and edge detection unit (the leading edge of the sheet is positioned on the upstream side of the edge detection unit). 
         FIG. 8  is a block diagram showing a control system of the printer according to the invention. 
         FIG. 9  is a flowchart of a recording execution operation of the printer according to the invention. 
         FIG. 10  is a drawing schematically showing the positional relationship between the edge guide, sheet, carriage, and edge detection unit (the leading edge of the sheet is positioned on the downstream side of the edge detection unit). 
         FIG. 11  is a drawing schematically showing the positional relationship between the edge guide, sheet, carriage, and edge detection unit (the leading edge of the sheet is positioned on the downstream side of the edge detection unit). 
         FIG. 12  is a plan view of a rack and pinion mechanism with which the first and second edge guides are interlocked. 
         FIG. 13  is a plan view of a rack and pinion mechanism with which the first and second edge guides are interlocked. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Below, embodiments of the invention are described with reference to the drawings. Like configurations in each embodiment have the like references applied thereto, description thereof will be made only in the first embodiment, and description of the configurations will not be repeated in subsequent embodiments. 
       FIG. 1  is a perspective view of a printer according to the aspect of the invention,  FIG. 2  is a side cross-sectional view showing the paper transport path of the printer of the invention,  FIG. 3  is a perspective view showing the apparatus main body of the printer according to the invention,  FIG. 4  is a plan view showing the main body of the printer according to the invention, and  FIG. 5  is a perspective view showing the lower surface of the carriage according to the invention. 
       FIG. 6  is a plan view showing a state in which the leading edge of the sheet is positioned on the upstream side of the edge detection unit in a sheet feeding state,  FIGS. 7, 10, and 11  are drawings schematically showing the positional relationship between the edge guide, sheet, carriage, and edge detection unit,  FIG. 8  is a block diagram showing the control system of the printer according to the invention, and  FIG. 9  is a flowchart of the recording execution operation of the printer according to the invention.  FIG. 12  is a plan view of a rack and pinion mechanism with which the first and second edge guides are interlocked. 
     In the X-Y-Z coordinate system shown in each diagram, the X direction indicates the scanning direction of the recording head, the Y direction the depth direction and sheet transport direction of the recording apparatus, and the Z direction the direction changing the distance (gap) between the recording head and the sheet, that is, the height direction of the apparatus. In each diagram, the −Y direction is set to the front surface side of the apparatus, and the +Y direction is set as the rear surface side of the apparatus. 
     Outline of Printer 
     The constituent elements of the ink jet printer  10  (below, referred to as “printer  10 ”) will be described as an example of the recording apparatus with reference to  FIGS. 1 ,  2  and  9 . The printer  10  as shown in  FIG. 1  is provided with an apparatus main body  12  and a cover  14 . 
     The cover  14  is rotatably attached to that apparatus main body  12  on the front surface of the apparatus main body  12 . The cover  14  is able to adopt an opened posture (not shown) and a closed posture (refer to  FIG. 1 ) with respect to the apparatus main body  12 . By the cover  14  being in an opened posture with respect to the apparatus main body  12 , it is possible for the sheet P (refer to  FIGS. 7 to 9 ) recorded in the apparatus main body  12  to be discharged to the front surface side of the printer  10 . 
     Next, the constituent elements of on the paper transport path will be described in further detail with reference to  FIG. 2 . The double-dotted and dashed line P′ extending from the rear surface side (+Y axis direction side in  FIG. 2 ) of the apparatus to the front surface side of the apparatus (−Y axis direction side in  FIG. 2 ) in  FIG. 2  indicates the transport path of the sheet P (refer to  FIGS. 7 to 9 ). A feeding portion  16  is provided on the rear surface side (+Y direction side in  FIG. 2 ) of the apparatus main body  12 . The feeding portion  16  is provided with a hopper  18  and a feed roller  20 . 
     The hopper  18  is configured to be able to mount sheets P on a support surface  18   a . The hopper  18  is provided to be able to swing (+Z axis direction side in FIG.  2 ) with respect to the apparatus main body  12  with the upper side as a fulcrum. The hopper  18  is provided so as to be able to advance and retreat with respect to the feed roller  20 . A state of swinging in a direction approaching the feed roller  20  in the hopper  18  is the feeding posture of the sheet P of the hopper  18  (refer to the double dotted and dashed portion in  FIG. 2 ). 
     The edge guide provided in the hopper  18  will be described. The hopper  18  is provided with a first edge guide  46  and a second edge guide  48  that control the end portion in the X axis direction, that is, the side edge, of the sheet P mounted on the support surface  18   a  as shown in  FIGS. 3, 4, and 6 . The first edge guide  46  and the second edge guide  48  are arranged with respect to the X axis direction on the support surface  18   a  of the hopper  18 . 
     The edge guides will be further described with reference to  FIG. 7  schematically showing the positions thereof. From among the side edges of the sheet P, the first edge guide  46  guides the side edge SE 1  on the home position side (right side in  FIG. 7 ) of the carriage  34 , and the second edge guide  48  guides the side edge SE 2  of the carriage  34  on the opposite side (left side in  FIG. 7 ) to the home position. 
     Although the home position of the carriage  34  is described in detail later, the home position of the carriage  34  in the embodiment is at the right end portion of  FIG. 7 , and the carriage indicated by the virtual line and the reference numeral  34  in  FIG. 7  is shown at the home position. The carriage indicated by reference numeral  34 ′ is shown at the end portion on the opposite side to the home position. Similarly, the reference numerals  36 ′ and  38 ′ are positions of the recording head (described later) and the edge detection unit (described later), respectively, when the carriage  34  is at the end portion on the opposite side to the home position. 
     Next, the second edge guide  48  is provided so that a user is capable of a sliding operation in the sheet width direction (X direction) according to the sheet size. In contrast, the first edge guide  46  is basically not provided on the assumption of a user performing a sliding operation. Specifically, the first edge guide  46  is provided so as to slide in synchronization with the second edge guide  48  by the rack and pinion mechanism as shown in  FIGS. 12 and 13 . 
     An arm portion  46   b  extending toward the second edge guide  48  is formed on the first edge guide  46 , and a rack portion  46   a  is formed on the leading edge thereof. An arm portion  48   b  extending toward the first edge guide  46  is formed on the second edge guide  48 , and a rack portion  48   a  is formed on the leading edge thereof. A pinion  49  is provided to freely rotate between the rack portion  46   a  and the rack portion  48   b . The reference numeral  49   a  and reference numeral  49   b  indicate a first gear portion that meshes with the rack portion  46   a  in the pinion  49 , and a second gear portion that meshes with the rack portion  48   a  in the pinion  49 , respectively. 
     The first edge guide  46  is provided to be able to displace in the sheet width direction, and is imparted with frictional resistance to the sliding by a friction unit, not shown. The pinion  49  is also imparted with frictional resistance to the rotation by the friction unit, not shown. 
       FIG. 12  shows a state in which both of the first edge guide  46  and the second edge guide  48  are positioned to the outermost side, and, in this state, the rack portions  46   a  and  48   a  each mesh with the pinion  49 . From this state, when the second edge guide  48  is slid in the right direction (direction approaching first edge guide  46 ) in the drawing matching the sheet size, the rack and pinion mechanism is operated, and the first edge guide  46  is displaced in a direction (left direction in drawing) approaching the second edge guide  48  in synchronization with the second edge guide  48 . 
     However, since the rack portions  46   a  and  48   a  are formed only on one portion of the arm portions  46   a  and  48   a , respectively, when the second edge guide  48  is slid a predetermined amount and the rack portions  46   a  and  48   a  each finish meshing with the pinion  49 , as shown in  FIG. 13 . That is, even if the second edge guide  48  is further slid in a direction approaching the first edge guide  46 , the first edge guide  46  does not slide in synchronization. 
     Below, when described in further detail, in a case of a sheet P with the maximum size that assumes use in the printer  10 , the first edge guide  46  as shown with a solid line in  FIG. 7 , is positioned furthest to the home position (right side in  FIG. 7 ), and the second edge guide  48  is positioned on the furthest side (left side in  FIG. 7 ) from the home position. The reference symbol X 0  in  FIGS. 7, 12 , and  13  indicates the sheet guide position due to the first edge guide  46  at this time, and the reference symbol X 5  indicates the sheet guide position due to the second edge guide  48  at this time. 
     From this state, when the second edge guide  48  is moved to the first edge guide  46  side (right side in  FIG. 7 ) in order to correspond to a small-sized sheet, the first edge guide  46  slides a predetermined amount in accordance with the movement of the second edge guide toward the second edge guide  48  side (inside) due to the function of the rack and pinion mechanism. The reference numeral  46 ′ in  FIG. 7  indicates the first edge guide after the slide operation is completed, and the reference symbol X 1  indicates the sheet guide position due to the first edge guide  46 ′ at this time. 
     When the first edge guide  46  slides a predetermined amount to the inside in this way, the rack and pinion mechanism as described above stops operation. Accordingly, even if the second edge guide  48  is slid more than this (for example, if moved from the position of reference numeral  48 ′ (sheet guide position X 4 ) to the position of reference numeral  48 ″ (sheet guide position X 3 )), the first edge guide  46  does not move to the inside. That is, the position indicated by reference numeral  46 ′ in  FIG. 7  is maintained. 
     As above, in a case of a sheet P with the maximum size, the position of the side edge SE 1  on the home position side is the guide position X 0 , and in the case of a sheet P with a smaller size, the position of the side edge SE 1  on the home position side is the guide position X 1 . In other words, the sheet guide position on the home position differs according to the sheet size. The reason for being configured in this way is described later. 
     Next, the description of the configuration on the paper transport path will be continued returning to  FIG. 2 . A feed roller  20  driven by a driving motor, not shown, is provided at a position facing the hopper  18  in the paper transport path. When the hopper  18  swings with the upper side (+Z axis direction side in  FIG. 2 ) as a fulcrum and adopts a paper feed posture (refer to the double dotted and dashed line part in  FIG. 2 ), the sheet P stacked on the uppermost position on the support surface  18   a  of the hopper  18  is picked up by the feed roller  20  and is fed to the downstream side of transport path. 
     A transport portion  22  is provided on the downstream side of the feed roller  20  in the transport path of the sheet P. The transport portion  22  is provided with a sheet detection unit  24 , a transport driving roller  26 , and a transport driven roller  28 . The sheet detection unit  24  is provided to freely advance and retreat with respect to the transport path of the sheet P. 
     When the sheet P is transported from the feeding portion  16  to the downstream side of the transport path, the sheet detection unit  24  contacts the leading edge Pf (refer to  FIG. 7 ) of the sheet P, is pressed to the sheet P as shown with the change from the sold line to the virtual line, and rotates in the clockwise direction in  FIG. 2 . In so doing, the sheet detection unit  24  detects that the sheet P is transported in the transport portion  22  in the transport path, and the detection information thereof is sent to the controller  30  (refer to  FIG. 9 ), described later. The controller  30 , based on the detection information of the leading edge Pf of the sheet P of the sheet detection unit  24 , is able to perform positioning (leading edge-positioning) of the leading edge Pf of the sheet P at a position facing the recording head  36  in the recording portion  32 , described later. 
     The transport driving roller  26  is rotated by a driving source, not shown. The transport portion  22  nips the sheet P fed from the feeding portion  16  between the transport driving roller  26  and the transport driven roller  28 , and transports the sheet to the downstream side in the transport direction. A recording portion  32  is provided on the downstream side of the transport portion  22 . 
     The recording portion  32  is provided with a carriage  34 , a recording head  36  provided on the bottom portion of the carriage, an edge detection unit  38  (refer to  FIG. 5 ) provided on the bottom portion of the carriage  34 , and a platen  40  that faces the recording head  36  and supports the sheet P. The recording head  36  faces the sheet P supported by the platen  40 . The carriage  34  is driven to reciprocate in the main scanning direction (the front to back direction of the paper surface, that is, the X axis direction, in  FIG. 2 ) as the “predetermined direction” by a driving motor, not shown, controlled by the controller  30  (refer to  FIG. 9 ) provided on the interior of the apparatus main body  12 . 
     The platen  40  regulates the distance (gap) between the recording surface of the sheet P and the head surface of the recording head  36  by supporting the sheet P from beneath. A plurality of nozzle holes (not shown) is provided on the surface facing the sheet P of the recording head  36 , and recording is executed on the sheet P by ink being discharged from the nozzle holes toward the recording surface of the sheet P. 
     A discharge portion  42  is provided on the downstream side of the recording portion  32  in the transport direction. The discharge portion  42  includes a discharge driving roller  44 . The sheet P on which recording is executed by the recording portion  32  is discharged toward the front of the apparatus by a discharge driving roller  44 . The discharge driving roller  44  is rotated by a driving source, not shown. 
     Next, the mechanism by which the carriage  34  in the recording portion  32  will be described. The recording portion  32  is further provided with a carriage driving mechanism  50  with which the carriage  34  is moved in the X axis direction in  FIG. 3 , and a carriage driving motor  52  with which the carriage driving mechanism is driven. The carriage driving motor  52  is attached to the end portion on the +X axis direction side of the frame  54  extending in the X axis direction in the apparatus main body  12 . 
     The carriage driving mechanism  50  is provided with a driving pulley  56 , a driven pulley (not shown), and a timing belt  58 . The driving pulley  56  is attached to the drive shaft of the carriage driving motor  52 . The driven pulley, not shown, is attached to be able to be driven to rotate with respect to the driving pulley  56  on the −X axis direction side of the frame  54 . The timing belt  58  is wrapped on the driving pulley  56  and the driven pulley, not shown. 
     A portion of the timing belt  58  is held and supported by the carriage  34 . Accordingly, when the carriage driving motor  52  is rotatably driven, the timing belt  58  is driving via the driving pulley  56 , and the carriage  34  moves in the X axis direction. The carriage driving mechanism  50  and the carriage driving motor  52  are controlled by the controller  30  as shown in  FIG. 8 . 
     Next, a linear scale  61  (refer to  FIG. 3 ) extending along the X axis direction is provided on the frame  54 . An encoder sensor  63  (refer to  FIG. 9 ) is provided on the rear surface side of the carriage  34 . The encoder sensor  63  is configured to be able to detect the linear scale  61 . The encoder sensor  63  will be further described later. 
     Next, a signal line cable  60  as shown in  FIGS. 3 and 4  is connected to the side surface of the +X direction side of the carriage  34  (in  FIG. 6 , the signal line cable  60  is not shown). The signal line cable  60  is configured as a flexible flat cable (FFC) in one example. The other end side of the signal line cable  60  is connected to the controller  30  once fixed to the frame  62 . 
     The signal line cable  60  is curled inside the region in which the carriage  34  is movable and connected to the carriage  34 . In other words, the signal line cable  60  extends from the side surface on the +X direction side of the carriage  34  to the +X direction side in the movable region L. The signal line cable  60  is deformed following the movement operation of the carriage  34 . 
     Although the curled part is positioned on the paper transport path as shown in  FIG. 4  in a state in which the carriage  34  is positioned at the home position, when the carriage  34  moves to the opposite side (left end in  FIG. 4 ) to the home position, the signal line cable  60  retreats from the paper transport path (not shown). 
     Next, the configuration of the carriage  34  will be further described with reference to  FIG. 5 . The carriage  34  in the example is formed in a box shape, and an ink cartridge  64  (refer to  FIG. 3 ) is attached to the upper surface side to be replaceable from the +Z axis side. The recording head  36  and the edge detection unit  38  are provided on the bottom portion of the carriage  34 . 
     The edge detection unit  38  is positioned on the +X axis side in  FIG. 5  with respect to the recording head  36  and arranged close to the end portion on the +Y axis side of the carriage  34 . The edge detection unit  38  in the example is configured as one example of a reflection-type optical detection device. 
     The detection position in the X axis direction of the edge detection unit  38  is the inside of the sheet passing region W (region between the guide position X 0  and the guide position X 5 ) when the first edge guide  46  as shown in  FIG. 7  is positioned to the outermost side (home position side) (guide position X 0  in  FIG. 7 ). This will be described in detail later. 
     A sliding portion  66  is provided on the end portion on the −Y direction side of the carriage  34 . Sliding portions  68  and  68  are provided on the end portion on the +Y direction side of the carriage  34 . Again referring to  FIG. 4 , a guide  70  is provided on the frame  54  side along the region L in which the carriage  34  is movable, and a guide  72  is provided on the frame  62  side. 
     When the carriage  34  moves due to the carriage driving mechanism  50  in the X axis direction within the movable region L, the sliding portion  66  of the carriage  34  slides on the guide  72 , and the sliding portions  68  and  68  slide on the guide  70 . 
     Incidentally, in a case where the carriage  34  is positioned to the rightmost end (end portion on the −X axis side) in the drawings in the movable range of the carriage  34 , the reference symbol L 0  in  FIGS. 4, 6, and 7  indicates the position of the right side wall of the carriage  34 . Similarly, in a case where the carriage  34  is positioned to the left most end (end portion on the +X axis side) in the drawings in the movable range of the carriage  34 , the reference symbol L 2  indicates the position of the left side wall of the carriage  34 . The carriage  34  is able to move in the range (movable region L) of the position L 0  and the position L 2 . 
     A capping unit  74  that caps the recording head  36  provided on the carriage  34  is provided as shown in  FIG. 6  outside the passing region of the sheet P that is the region on the −X axis direction side of the region in which the carriage  34  is movable. The capping unit  74  suppresses drying of the ink in the plurality of nozzle rows provided in the recording head  36  by capping the recording head  36 , and is thus able to suppress nozzle clogging. The position of the carriage  34  when the capping unit  74  caps the recording head  36  is the home position as the “predetermined position” of the carriage  34 , and the right side wall of the carriage  34  at the home position is positioned slightly further to the inside (left side in  FIGS. 4, 6, and 7 ) than the position L 0 . 
     Next, the control system of the printer  10  will be described with reference to  FIG. 8 . The carriage  34  is driving by a CR (carriage) motor  52  as described above. An encoder sensor  63  is provided on the carriage  34 . The encoder sensor  63  is configured provided with a light emitting portion (not shown) and a light sensing portion (not shown), and the linear scale  61  extending along the X axis direction is provided so as to be interposed by the light emitting portion and the light sensing portion. Accompanying the movement of the carriage  34 , the encoder sensor  63  transmits a rectangular wave signal accompanying the passage of the plurality of slits formed in the linear scale  61  to the controller  30  as a control unit, and, in so doing, the controller  30  is able to detect the position and speed in the main scanning direction of the carriage  34 . 
     Next, the transport portion  22  is driven by the PF motor  75 . A disk-shaped rotary scale (not shown) that configures the rotary encoder  76  is provided in the driving target, for example, the transport driving roller  26 , driven to rotate by the PF motor  75 . The rotary encoder  76  is provided with a light emitting portion (not shown) and a light sensing portion (not shown), and the rotary scale is provided so as to be interposed by the light emitting portion and the light sensing portion. Accompanying the rotation of the PF motor  75 , the rotary encoder  76  a rectangular wave signal accompanying the passage of the plurality of slits formed in the rotary scale to the controller  30  as a control unit, and, in so doing, the controller  30  is able to detect the rotation amount and the rotation speed of the driving target driven by the transport driving roller  26  or other PF motor  75 . 
     The controller  30  detects the passing of the sheet P based on the detection signal transmitted from the sheet detection unit  24 , and performs any necessary control. The controller  30  is further able to ascertain the presence of passing under the edge detection unit  38  of the sheet P using the signal information received from the edge detection unit  38  and to ascertain the edge position (leading edge, trailing edge position, side edge position) of the sheet P. 
     The RAM  78 , ROM  79 , ASIC  77 , CPU  81 , and EEPROM (nonvolatile memory)  80  are connected to the system bus of the controller  30 . 
     Output signals of a power switch (not shown) for turning the power source of the rotary encoder  76 , encoder sensor  63 , sheet detection unit  24 , and printer  10  on and off or various other setting buttons (not shown) is input to the CPU  81  via the ASIC  77 . The CPU  81  performs calculation processing for executing recording control of the printer  10  or other necessary calculation processing based on the output signals or the like of each type of sensor or switch. 
     A recording control program (firmware) or the like necessary to the control of the printer  10  by the CPU  81  is stored in the ROM  79 , and various data and the like necessary in the processing of the recording control program are stored in the EEPROM  80 . The RAM  78  is used as work region for the CPU  81  or a temporary storage region for recording data or the like. 
     The ASIC  77  includes a control circuit for performing rotation control of the PF motor  75  that is a DC motor and the CR motor  52  and driving control of the recording head  36 . The reference symbol  83  is the CR controller that performs rotation control of the CR motor  52 , based on the pulse signal (pulse period) output from the encoder sensor  63 , and the CR controller  83  calculates the present speed of the carriage  34 , and performs PID control (feedback control) on the driving of the CR motor  52  for each minute time period (control step. Also referred to as a PID control period) so that the speed follows a speed profile set in advance. 
     The PF controller  84  calculates the present rotation speed (value compared to the rotation amount) of the transport driving roller  26 , based on the pulse signal (pulse period) output from the rotary encoder  76 , and performs PID control (feedback control) on the driving of the PF motor  75  so that the speed follows a speed profile set in advance. 
     The CR motor driver  86  generates the PWM signal as a pulse by pulse-width modulation on the direct current as the power source voltage according to the duty ratio DR (ratio of ON time period with respect to the pulse period) and outputs the signal to the CR motor  52 . The CR motor  52  is a DC motor, and rotates the PWM signal output from the CR motor driver  30  as the driving power source. The same applies to the relationship between the PF motor driver  85  and the PF motor  75 . 
     The ASIC  77  performs driving control on the recording head  36  by calculating and generating the control signal of the recording head  36 , based on the recording data transmitted from the CPU  81 , and sending the signal to the head driver  87 . The ASIC  77  further includes an IF  82  that realizes information transfer with the external computer  90  and the like as an information processing apparatus. 
     Control During Recording Execution 
     Control during recording execution in the printer  10  provided with the above configuration will be described with reference to  FIG. 9  and other drawings. Firstly, when a recording execution command is sent by a user, the controller  30  references the sheet size information included in the printing settings information (driver information) (Step S 101 ), and divides control between a case in which the sheet width is a predetermined width (maximum size), that is, a case where it is possible to estimate that the first edge guide  46  is at the guide position X 0  in  FIG. 7 , and a case in which the sheet width is less than a predetermined width, that is, a case where it is possible to estimate that the first edge guide  46  is at the guide position X 1  in  FIG. 7 . At the start point of the printing job, the carriage  34  is positioned at the home position that is an example of the predetermined position. 
     Below, a case where the sheet width is the predetermined width (maximum size), that is, a case where it is possible to estimate that the first edge guide  46  is at the guide position X 0  in  FIG. 7  from the sheet size information, will be described. In this case, when the sheet is fed (Step S 102 ), if the first edge guide  46  is correctly at the guide position X 0 , the sheet P, as clarified in  FIG. 7 , passes under the edge detection unit  38 . That is, it is possible to detect the leading edge of the sheet (Yes in Step S 103 ).  FIG. 10  shows the state at this time. Assuming a case where the leading edge of the sheet is not detected, because it is possible to determine that a paper jam has occurred, or that the position of the first edge guide  46  or the sheet size is inappropriate, an error process is performed (No in Step S 103 ). 
     In a case in which the leading edge of the sheet is detected, it is determined whether or not the borderless recording is performed from the information included in the printing settings information (driver information) (Step S 104 ). In a case of the borderless recording (Yes in Step S 104 ), the printing process is not supported and an error process is performed. In a case of not performing the borderless recording (No in Step S 104 ), the carriage  34  is moved to the non-home position side, and the position of the side edge SE 2  on the non-home position side is detected (Step S 105 ). The position detection of the sheet side edge in the embodiment is performed when the edge detection unit  38  traces the edge from the inside of the sheet to the outside. 
     Next, the carriage  34  is moved to the end portion position on the non-home position side (Step S 110 ).  FIG. 11  shows the state at this time. Next, when moving to the home position side, first recording is performed (Step S 111 ). 
     Next, a case where the sheet width is less than the predetermined width (maximum size), that is, a case where it is possible to estimate that the first edge guide  46  is at the guide position X 1  in  FIG. 7  from the sheet size information, will be described. In this case, when the sheet is fed (Step S 106 ), if the first edge guide  46  is correctly at the guide position X 1 , the sheet P, as clarified in  FIG. 7 , passes under the edge detection unit  38 . That is, the leading edge of the sheet is not detected (No in Step S 107 ). Assuming a case where the leading edge of the sheet is detected, because it is possible to determine the first edge guide  46  not correctly moving to the guide position X 1 , an error process is performed (Yes in Step S 107 ). 
     Next, detection of the side edge SE 1  on the home position side is performed (Step S 108 ), and then detection of the side edge SE 2  ion the non-home position side is performed (Step S 109 ). Position detection of the sheet side edges SE 1  and SE 2  at this time are also performed by the edge detection unit  38  tracing the edge from the inside of the sheet to the outside, as described above. Step S 110  onwards are as already described. 
     Below, the actions and effect of the printer  10  configured as above will be described. In a state where the carriage  34  is positioned at the predetermined position, that is, at the home position in the example, the edge detection unit  38  is positioned within the passing region W of the sheet P in the X axis direction that is the movement direction of the carriage  34  as shown in  FIG. 7 . Accordingly, the home position of the carriage  34  attains a state close to the passing region W side of the sheet P. Accordingly, in so doing, the horizontal width dimensions (dimensions in the X axis direction) of the apparatus are suppressed, it is possible for the size of the apparatus to be reduced. 
     In the embodiment, although the predetermined position of the carriage  34  is the home position and the position where the recording head  36  is capped by the capping unit  74 , there is no limitation thereto, and the predetermined position is preferably the end portion position (case where the right side wall of the carriage  34  in  FIG. 7  is positioned at the position L 0 ) on one side in the movement region of the carriage  34 . 
     In the embodiment, the leading edge detection mode (corresponds to Steps S 102  and S 103  in  FIG. 9 ) for detecting the leading edge Pf is executed, by transporting the leading edge Pf of the sheet P until passing through a position facing the edge detection unit  38  in a state where the carriage  34  is stopped at the predetermined position (home position) during leading edge-positioning of the sheet P (corresponds to Step S 102  in  FIG. 9 ). 
     Accordingly, it is possible to detect the passing of the leading edge Pf of the sheet with the carriage  34  stopped as is at the predetermined position (home position), that is, it is possible to suppress a lowering of the recording throughput without it being necessary for the carriage  34  to be moved from the predetermined position (home position) to the detection position. 
     In the embodiment, the controller  30  does not perform the borderless recording that performs recording without white space on the end portion of the sheet P (Yes in Step S 104  in  FIG. 9 ), in a case where the leading edge detection mode is executed. That is, in a case where only the side edge SE 2  on one side of the sheet P is detected (case where side edge SE 1  on the other side is not detected), since the borderless recording in which recording position shifts are easily visible is not executed, it is possible to ensure a suitable recording quality. 
     The controller  30  executes the side edge detection mode for detection the side edge SE 2  on one side of the sheet P (corresponds to Step S 105  in  FIG. 9 ) by the carriage  34  being moved to the non-home position side until the edge detection unit  38  is separated from the region of the sheet P after execution of the leading edge detection mode. In this way, by detecting the side edge SE 2  on one side, recording position shifts are suppressed and it is possible to obtain better recording results. 
     In the embodiment, the signal line cable  60  extends from the side surface of the carriage  34  on the opposite side to the home position, and the controller  30  performs first recording on the sheet P with the recording head  36  (corresponds to Steps S 110  and S 111  in  FIG. 9 ) when the carriage  34  is moved toward the home position side after the side edge detection mode is executed. 
     In so doing, the actions and effects are as described below. That is, in a case where the signal line cable  60  extends from the side surface of the carriage  34  on the opposite side to the home position side, when the carriage  34  is positioned at the home position, a state is attained where the signal line cable  60  is positioned at the upper portion of the sheet transport region as shown in  FIG. 4 . Accordingly, in this case, it is difficult to perform jam processing tasks in a case in which a jam occurs in the sheet transport path and there is concern of a breakdown occurring by the user touching the signal line cable  60 . 
     Meanwhile, when the carriage  34  is positioned at the end portion on the opposite side (below, referred to as “opposite side end portion position”) to the home position side, the signal line cable  60  retreats from the upper portion of the sheet transport region. 
     Here, there is concern of the recording head  36  coming into contact with the side edges SE 1  and SE 2  as the side edges SE 1  and SE 2  of the sheet P moves upward and a jam arising as a result. That is, the jam accompanying the movement of the carriage  34  easily occur when the recording head  36  moves from the outside of the sheet P towards the inside during first recording on the sheet P. 
     In a case in which the first recording on the sheet P is performed from the home position side of the carriage  34 , when a jam occurs in this step, the carriage  34  is able to undertake only one of stopping at the position or returning to the home position. Thus, because the signal line cable  60  is positioned on a position above the sheet transport region as shown in  FIG. 4  during jam processing tasks by the user, there is concern of the above-described problem arising. 
     However, since the controller  30  performs first recording with the recording head  36  when the carriage  34  is moved from the end portion on the opposite side to the home position towards the home position after the side edge detection mode is executed (Steps S 110  and S 111  in  FIG. 9 ), in this case, because if a jam occurs, the carriage  34  is positioned at the end portion on the opposite side to the home position, the signal line cable  60  retreats from the upper portion of the sheet transport region as a result, it is possible for the problem to be avoided. 
     In the embodiment, first edge guide  46  is movable to the second edge guide  48  side until the sheet passing region is separated from the arrangement position of the edge detection unit  38  in a state in which the carriage  34  is positioned at the home position (guide position X 1  in  FIG. 7 ). 
     Accordingly, by moving the first edge guide  46  to the guide position X 1  in  FIG. 7 , it is possible for the side edge SE 1  on the home position side of the sheet P to be detected by the edge detection unit  38 . That is, since it is possible to detect the side edge on both sides of the sheet P, shifting of the recording position is more reliably suppressed, and it is possible for a better recording result to be obtained. In particular, during the borderless recording, an excellent recording result is obtained with suppression of shifting of the recording position. 
     When the second edge guide  48  is moved toward the first edge guide  46  side, the first edge guide  46  in the embodiment moves in accordance with the movement of the second edge guide in a direction toward the second edge guide  48  with the predetermined guide position as a boundary. In the embodiment, when the second edge guide  48  is moved from the guide position X 5  to the right side in  FIG. 7 , because the first edge guide  46  is interlocked, the predetermined guide position is the guide position X 5  in  FIG. 7 . 
     In this way, in the embodiment, since the first edge guide  46  moves in accordance with the movement of the second edge guide  48 , the operability for the user is improved. 
     In the embodiment, although a user operates the second edge guide  48  on the left side when viewed from the front of the apparatus to slide, and the first edge guide  46  on the right side of the apparatus slides and displaces with the rack and pinion mechanism according to the operation, the configuration may be reversed. In the embodiment, the apparatus is preferably configured such that the user operates the first edge guide  46  on the right side when viewed from the front of the apparatus to slide, and the second edge guide  48  on the left side of the apparatus slides and displaces with the rack and pinion mechanism, according to the operation. That is, the configuration shown in  FIGS. 12 and 13  is preferably made a form in which left and right are mirrored. 
     In the embodiment, although the edge detection unit  38  according to the invention is applied to an ink jet printer as an example of the recording apparatus, application is generally also possible to other liquid ejecting apparatuses. The liquid ejecting apparatus is not limited to a recording apparatus such as a printer, copy machine and fax machine in which an ink jet type recording head is used and which performs recording on a recording medium by ejecting ink from the recording head, and includes an apparatus ejecting, in place of ink, a liquid corresponding to other uses from a liquid ejecting head corresponding to an ink jet recording head to an ejection medium corresponding to a recording medium, and the liquid is applied to the ejection medium. 
     In addition to the recording head, examples of the liquid ejecting head include a coloring material ejecting head used in the manufacturing of a color filter for a liquid crystal display or the like, an electrode material (conductive paste) ejecting head used in electrode formation of an organic EL display, a field emission display (FED), or the like, a bio-organic ejecting head used in biochip manufacturing, or a sample ejecting head as a precision pipette. 
     The invention is not limited to the embodiments described above and may be modified in various ways within the aspects described in claims, and the modifications should be construed as being included in the invention. 
     The entire disclosure of Japanese Patent Application No. 2014-34381, filed Feb. 25, 2014 is expressly incorporated by reference herein.