Patent Publication Number: US-11034175-B2

Title: Sliding mechanism and ink-jet printer

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the priority benefit of Japanese Patent Application No. 2019-028311, filed on Feb. 20, 2019. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
     TECHNICAL FIELD 
     The present disclosure relates to a sliding mechanism including a slider that linearly moves in a predetermined direction. Furthermore, the present disclosure relates to an ink-jet printer including the sliding mechanism. 
     DESCRIPTION OF THE BACKGROUND ART 
     Conventionally, known is an ink-jet printer of a so-called flat-bed type, which carries out printing operation on a print medium placed on a stage part (refer to Patent Document 1). An ink-jet printer, described in Patent Document 1, has a carriage on which a discharging head is mounted, a Y-bar provided with a Y-axis guide rail for guiding the carriage in a main travelling direction, and a Y-axis transfer mechanism for moving the carriage in the main travelling direction in relation to the Y-bar. Moreover, the ink-jet printer includes: a slider, to which two columns, being provided at both end sides of the Y-bar in the main travelling direction, are individually fixed; an X-axis frame provided with an X-axis guide rail for guiding the slider in a sub travelling direction; and an X-axis transfer mechanism for moving the slider in the sub travelling direction in relation to the X-axis frame. The X-axis frame is placed at both end sides of a stage part in the main travelling direction. 
     In the ink-jet printer described in Patent Document 1, a liner scale is installed on the X-axis frame. The liner scale is placed along the sub travelling direction. On a top surface of the liner scale, there are formed minute bumps in a series in the sub travelling direction. In the slider, there is installed a sensor in such a way as to face the top surface of the liner scale. In the ink-jet printer described in Patent Document 1, a movement distance of the slider in relation to the X-axis frame can precisely be detected by use of the sensor installed to the slider and the liner scale. Therefore, in the ink-jet printer, an ink-jet head can precisely be moved in the sub travelling direction, in relation to a print medium placed on the stage part, on the basis of a detection result of the sensor. 
     [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2012-210781 
     In the case of the ink-jet printer described in Patent Document 1, a distance through which the slider can move in relation to the X-axis frame is comparatively long; and therefore, without making the linear scale long, there appears a place where a movement distance of the slider in relation to the X-axis frame cannot be detected. Accordingly, in the case of the ink-jet printer, a length of the linear scale becomes long so that a cost of the linear scale becomes high. 
     Then, it is an objective of the present disclosure to provide a sliding mechanism including a slider that can linearly move in relation to a support member, and a linear encoder for detecting a movement distance of the slider in relation to the support member; in the sliding mechanism, even though a distance through which the slider can move in relation to the support member is comparatively long, the movement distance of the slider in relation to the support member can be detected, while a length of a linear scale being made short. Moreover, it is another objective of the present disclosure to provide an ink-jet printer including the sliding mechanism. 
     SUMMARY 
     In order to solve the issue described above, a sliding mechanism according to the present disclosure includes: a slider that is capable of linearly moving in relation to a support member in a predetermined direction; a second slider that is capable of linearly moving in relation to the support member as well as the slider in the same direction as a moving direction of the slider; a slider transfer mechanism that transfers the slider; a second slider transfer mechanism that transfers the second slider; and a linear encoder for detecting a movement distance of the slider in relation to the support member. The linear encoder includes a linear scale fixed to one of the slider and the second slider, and a sensor fixed to the other of the slider and the second slider. The second slider transfer mechanism transfers the second slider in relation to the support member and the slider; and subsequently, while the second slider is kept in a state of being stopped, the slider transfer mechanism transfers the slider in relation to the support member and the second slider. 
     In the sliding mechanism according to the present disclosure, the linear scale is fixed to either the slider or the second slider, and the sensor is fixed to the other of the slider and the second slider. Moreover, according to the present disclosure, after transferring the second slider in relation to the support member and the slider, the slider is transferred in relation to the support member and the second slider, while the second slider is kept in a state of being stopped. In other words, according to the present disclosure; before transferring the slider, either the linear scale or the sensor is transferred together with the second slider in relation to the support member and the slider, and subsequently the slider is transferred in relation to the support member and the second slider in such a way as to relatively move the sensor in relation to the linear scale. 
     Therefore, according to the present disclosure, even though a distance through which the slider can move in relation to the support member is comparatively long, and even though a length of the linear scale is made short, it becomes possible to detect the movement distance of the slider in relation to the support member by use of the linear scale and the sensor. In other words, according to the present disclosure, even though a distance through which the slider can move in relation to the support member is comparatively long, it becomes possible to detect the movement distance of the slider in relation to the support member, while the length of the linear scale is made short. 
     In the present disclosure, it is preferable that the linear scale is fixed to the slider, and the sensor is fixed to the second slider. According to this configuration, being compared to a case where the linear scale is fixed to the second slider, the second slider can be downsized. 
     In the present disclosure, it is preferable that the second slider transfer mechanism includes a motor fixed to one of the slider and the second slider, and a power transmission mechanism for transmitting power of the motor to the other of the slider and the second slider, from the motor. According to this configuration, the second slider transfer mechanism together with the slider and the second slider can be transferred in relation to the support member; and therefore, being compared to a case where the motor is installed to either of the support member or the second slider, and the power transmission mechanism transmits the power of the motor to the other of the support member or the second slider, from the motor; the power transmission mechanism can be downsized. 
     In the present disclosure, it is preferable that the power transmission mechanism includes a clutch placed in a power transmission route, which leads from the motor to the other of the slider and the second slider; and when the second slider moves in relation to the support member and the slider, the clutch transmits the power of the motor to the other of the slider and the second slider; and when the slider moves in relation to the support member and the second slider, the clutch blocks up the power transmission route from the motor to the other of the slider and the second slider. According to this configuration, at the time when the slider is transferred in relation to the support member and the second slider, it becomes possible by way of a comparatively easy way to maintain the slider, in the state of being stopped, at the stop position. 
     In the present disclosure, for example, the power transmission mechanism includes a rack fixed to the other of the slider and the second slider, and a pinion connected to an output shaft of the motor by an intermediary of the clutch, and the pinion being meshed with the rack; and the clutch transmits the power of the motor to the pinion, at a time when the second slider moves in relation to the support member and the slider; and the clutch blocks up the power transmission route from the motor to the pinion, at a time when the slider moves in relation to the support member and the second slider. 
     In the present disclosure, it is preferable that the motor is installed to the slider; and the rack is fixed to the second slider. According to this configuration, being compared to a case where the motor is fixed to the second slider, the second slider can be downsized. 
     In the present disclosure, the sliding mechanism includes a retainer mechanism for retaining the second slider, being in a stop state, at a stop position. According to this configuration, it becomes possible to transfer the slider in relation to the support member and the second slider, in the state where the second slider is stopped for sure. Therefore, detection accuracy by use of the linear encoder with regard to the movement distance of the slider can be enhanced. 
     In the present disclosure, for example, the retainer mechanism includes a contacting member that is capable of contacting the support member with a predetermined contact pressure; and a contacting member move mechanism that moves the contacting member between a contacting position, where the contacting member contacts the support member with the predetermined contact pressure, and a non-contacting position, where the contacting member is distant from the support member so as not to contact the support member; and the contacting member move mechanism is installed to the second slider. In this case, a structure of the retainer mechanism can comparatively be simplified. 
     In the present disclosure, for example, the sliding mechanism includes a detection mechanism for detecting a stop position of the second slider in relation to the slider. In this case, the slider can automatically be stopped, on the basis of a detection result of the detection mechanism. 
     In the present disclosure, it is preferable that the sliding mechanism includes a guide rail, which is fixed to the support member, for guiding the slider and the second slider in the moving direction of the slider; a guide block, being fixed to the slider, which engages with the guide rail in such a way as to be slidable, and a second guide block, being fixed to the second slider, which engages with the guide rail in such a way as to be slidable. According to this configuration, the slider and the second slider can be guided by use of the guide rail in common so that the structure of the sliding mechanism cam be simplified. 
     The sliding mechanism according to the present disclosure can be used for an ink-jet printer. The ink-jet printer, for example, includes two sliding mechanisms, each of which is the sliding mechanisms according to the present disclosure; an ink-jet head that discharges an ink drop on a print medium; a carriage on which the ink-jet head is mounted; a carriage holding member that holds the carriage in such a way as to be movable in a main travelling direction; and the support member. The support member includes a table where the print medium is placed. The two sliding mechanisms are individually placed at each of both ends of the table in the main travelling direction. An end part of the carriage holding member in the main travelling direction is connected to the slider. The slider and the second slider are movable in a sub travelling direction that is perpendicular to a vertical direction and the main travelling direction. 
     In the ink-jet printer, the movement distance of the carriage holding member in relation to the table can be detected, while the length of the linear scale being made short, even though a distance through which the carriage holding member can move in relation to the table, where the print medium is placed, is comparatively long. Therefore, in the ink-jet printer, even though a length of the table in the sub travelling direction is long, and even though the slider is able to move in relation to the table in an entire range of the sub travelling direction, it becomes possible to detect the movement distance of the carriage holding member in relation to the table, while the length of the linear scale is made short. 
     Advantageous Effect of the Invention 
     As described above, in the sliding mechanism according to the present disclosure, the movement distance of the slider in relation to the support member can be detected, while the length of the linear scale being made short, even though the distance through which the slider can move in relation to the support member is comparatively long. Furthermore, in the ink-jet printer according to the present disclosure, the movement distance of the carriage holding member in relation to the table can be detected, while the length of the linear scale being made short, even though the distance through which the carriage holding member can move in relation to the table, where the print medium is placed, is comparatively long. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view drawing of an ink-jet printer according to an embodiment of the present disclosure. 
         FIG. 2  is a rear-view drawing for explaining a structure of a sliding mechanism shown in  FIG. 1 . 
         FIG. 3  is a perspective view drawing for explaining the structure of the sliding mechanism shown in  FIG. 2 . 
         FIG. 4  is another perspective view drawing for explaining the structure of the sliding mechanism shown in  FIG. 2 . 
         FIG. 5  is still another perspective view drawing for explaining the structure of the sliding mechanism shown in  FIG. 2 . 
         FIG. 6  is a side view drawing for explaining the structure and operation of the sliding mechanism shown in  FIG. 2 . 
         FIG. 7  is another side view drawing for explaining the structure and operation of the sliding mechanism shown in  FIG. 2 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     A preferred embodiment according to the present disclosure is explained below with reference to the drawings. 
     (Schematic Configuration of Ink-Jet Printer) 
       FIG. 1  is a side view drawing of an ink-jet printer  1  according to an embodiment of the present disclosure. 
     The ink-jet printer  1  according to the present embodiment (hereinafter referred to as a printer  1 ) is an ink-jet printer for business use that carries out printing operation on a print medium, such as a printing paper. Moreover, the printer  1  according to the present embodiment is an ink-jet printer of a so-called flat-bed type. The printer  1  includes an ink-jet head  3  that discharges an ink drop on a print medium, a carriage  4  on which the ink-jet head  3  is mounted, a Y-bar  5  as a carriage holding member that holds the carriage  4  in such a way as to be movable in a main travelling direction, and a carriage transfer mechanism (not illustrated) for moving the carriage  4  in relation to the Y-bar  5 , in the main travelling direction. 
     The printer  1  further includes a table  6  where the print medium is placed, and a support leg  7  that supports the table  6 . In the present embodiment, a support member  8  is structured by use of the table  6  and the support leg  7 , in such a way as to hold the Y-bar  5  so as to be movable in a sub travelling direction that is perpendicular to a vertical direction and the main travelling direction. Moreover, the printer  1  includes a sliding mechanism  10  that slides the Y-bar  5  in relation to the support member  8 , in the sub travelling direction (namely, linearly transferring the Y-bar  5 ). 
     In the following explanation, the main travelling direction (i.e., a Y-direction shown in  FIG. 1  and others) and the sub travelling direction (i.e., an X-direction shown in  FIG. 1  and others) are dealt with as a right-and-left direction and a front-and-back direction, respectively. Then, an X1-direction side, shown in  FIG. 1  and the like as one direction side in the front-and-back direction is, represented as a “front” side, and an X2-direction side, shown in  FIG. 1  and the like as an opposite side to the above, is represented as a “rear” side; and meanwhile a Y1-direction side, shown in  FIG. 2  and the like as one direction side in the right-and-left direction, is represented as a “right” side, and a Y2-direction side, shown in  FIG. 2  and the like as an opposite side to the above, is represented as a “left” side. 
     The carriage  4  is placed at an upper side of the table  6 . The ink-jet head  3  discharges an ink drop from an upper side, toward the print medium placed on a top surface of the table  6 . The ink that the ink-jet head  3  discharges is, for example, ultraviolet curable ink (UV ink). To the carriage  4 , there is installed an ultraviolet radiation unit that radiates ultraviolet rays to the ink discharged from the ink-jet head  3 . The carriage transfer mechanism includes, for example, a motor, a drive pulley to be turned with power of the motor, a driven pulley, a belt placed over the drive pulley and the driven pulley, and the like. A part of the belt is fixed to the carriage  4 . The Y-bar  5  is shaped as a rectangular form elongated in a right-and-left direction. Both ends of the Y-bar  5  at right and left sides are supported from an under side by use of Y-bar support members  12 . 
     The table  6  is shaped like a rectangular thick plate. In a right-and-left direction, the table  6  is placed between two Y-bar support members  12 . The support leg  7  supports both ends of the table  6  at front and back sides, from an under side. The sliding mechanism  10  is placed at each of both the ends of the table  6  at right and left sides. In other words, the printer  1  includes two sliding mechanisms  10 . Explained below is a specific structure of the sliding mechanism  10 . Incidentally, explained below is a structure of the sliding mechanism  10 , positioned at a left side, of the two sliding mechanisms  10  placed at both the ends of the table  6  at the right and left sides. 
     (Structure of Sliding Mechanism) 
       FIG. 2  is a rear-view drawing for explaining a structure of the sliding mechanism  10  shown in  FIG. 1 .  FIG. 3  through  FIG. 5  are individually perspective view drawings for explaining the structure of the sliding mechanism  10  shown in  FIG. 2 .  FIG. 6  and  FIG. 7  are individually side view drawings for explaining the structure and operation of the sliding mechanism  10  shown in  FIG. 2 . 
     The sliding mechanism  10  includes: a slider  14  that can linearly move in relation to the support member  8  in a front-and-back direction (the sub travelling direction); another slider  15 , as a second slider, which can linearly move in relation to the support member  8  as well as the slider  14  in the front-and-back direction (in other words, in the same direction as a moving direction of the slider  14 ); a slider transfer mechanism  16  to transfer the slider  14 ; and a slider transfer mechanism  17 , as a second slider transfer mechanism, to transfer the slider  15 . 
     Moreover, the sliding mechanism  10  includes: a linear encoder  18  for detecting a movement distance of the slider  14  in relation to the support member  8 ; a retainer mechanism  19  for retaining the slider  15 , being in a stop state, at a stop position; a detection mechanism  20  for detecting the stop position of the slider  15  in relation to the slider  14 ; a guide rail  21  for guiding the slider  14  and the slider  15  in a front-and-back direction; and a guide block  22  and a guide block  23  that engage with the guide rail  21  in such a way as to be slidable. Incidentally, in  FIG. 4 ,  FIG. 6 , and  FIG. 7 , the slider transfer mechanism  16  and the like are not illustrated. Moreover, in  FIG. 5 , the slider  14  and the slider transfer mechanism  16  and the like are not illustrated. 
     The slider  14  is shaped so as to be like a flat plate. The slider  14  is placed in such a way that a thickness direction of the slider  14  is consistent with a vertical direction. Moreover, the slider  14  is placed at a side lower than the table  6  is. To the slider  14 , there is connected the Y-bar support member  12  that supports a left end part of the Y-bar  5 . Concretely to describe, as illustrated in  FIG. 2 , a left end part of the slider  14  is placed at a further left side than a left end surface of the table  6 , and a lower surface of the Y-bar support member  12  is fixed to the left end part of the slider  14  by the intermediary of a plate-like member  26 . In other words, the end part of the Y-bar  5  in a right-and-left direction is connected to the slider  14 , by the intermediary of the plate-like member  26  and the Y-bar support member  12 . Incidentally, in  FIG. 1  and  FIG. 3  through  FIG. 7 , the plate-like member  26  is not illustrated. 
     The slider  15  is formed by way of bending a metal plate, such as a steel plate and the like, into a predetermined shape. The slider  15  is placed at a lower side of the table  6 . In the slider  14 , there is formed a through hole  14   a  in which the slider  15  is placed. The through hole  14   a  completely passes through the slider  14  in a vertical direction. The through hole  14   a  is formed almost at a center position of the slider  14  in a front-and-back direction. A width of the through hole  14   a  in the front-and-back direction is wider than a length of the slider  15  in the front-and-back direction, in such a way that the slider  15  is able to move for a predetermined distance in the front-and-back direction in relation to the slider  14 . 
     The guide rail  21  is fixed to a lower surface of a left end part of the table  6 . In other words, the guide rail  21  is fixed to the support member  8 . The guide rail  21  is placed in such a way that a longitudinal direction of the guide rail  21  is consistent with a front-and-back direction. The guide block  22  is fixed to the slider  14 . Concretely to describe, two guide blocks  22  are fixed to an upper surface of the slider  14 . The guide block  23  is fixed to the slider  15 . Concretely to describe, one guide block  23  is fixed to an upper surface of the slider  15 . 
     The guide blocks  22  and the guide block  23  engage with the guide rail  21  from a lower side. One guide block  22  of the two guide blocks  22  is fixed to the upper surface of the slider  14 , at a position of a further front side than the through hole  14   a ; and meanwhile, the other guide block  22  is fixed to the upper surface of the slider  14 , at a position of a further rear side than the through hole  14   a . The guide block  23  is located between the two guide blocks  22  in the front-and-back direction. The guide block  23  of the present embodiment is a second guide block. 
     The slider transfer mechanism  16  includes: a motor  29  installed to the support member  8 ; and a ball screw unit having a screw shaft (lead screw)  30  and a nut component  31 . The screw shaft  30  is held by the support member  8 , in such a way as to be rotatable, in a state where a shaft direction of the screw shaft  30  is consistent with a front-and-back direction. The nut component  31  is installed at a right end side of the slider  14 . To the screw shaft  30 , there is connected the motor  29 , by the intermediary of a pulley and a belt; in such a way that the screw shaft  30  can be turned with power of the motor  29 . According to the present embodiment, if the motor  29  is driven, the screw shaft  30  turns so that the slider  14  moves together with the nut component  31 , running along the screw shaft  30  in the front-and-back direction. In other words, if the motor  29  is driven, the Y-bar  5  moves together with the slider  14  in the front-and-back direction. 
     Incidentally, the motor  29  is not illustrated in  FIG. 2  and  FIG. 3 . Alternatively, with the motor  29  being installed to the slider  14 ; the screw shaft  30  may be fixed to the support member  8 , while the nut component  31  being installed to the slider  14  so as to be rotatable. In this case, the motor  29  is connected to the nut component  31 , by the intermediary of a pulley and a belt; and the nut component  31  is in a state of being able to turn with power of the motor  29 . Then, in this case, if the motor  29  is driven, the nut component  31  turns so that the slider  14  moves together with nut component  31 , running along the screw shaft  30  in the front-and-back direction. 
     The slider transfer mechanism  17  includes: a motor  32  installed to the slider  14 ; a rack  33  fixed to the slider  15 , and a pinion  34  connected to an output shaft of the motor  32 . The motor  32  is fixed to a lower surface of the slider  14 . The output shaft of the motor  32  protrudes toward a left side. The rack  33  is placed in such a way that a longitudinal direction of the rack  33  is consistent with a front-and-back direction. A length of the rack  33  in the front-and-back direction is almost the same as the length of the slider  15  in the front-and-back direction. 
     The pinion  34  engages with the rack  33 . The pinion  34  is placed at a lower side of the rack  33 . Moreover, the pinion  34  is connected to the output shaft of the motor  32 , by the intermediary of a clutch  35 . In other words, there is placed the clutch  35  in a power transmission route to the slider  15  from the motor  32 . In an inner circumferential side of the pinion  34 , the output shaft of the motor  32  is inserted through. 
     The clutch  35  is an electromagnetic clutch. The clutch  35  transmits power of the motor  32  to the pinion  34 , at a time when the slider  15  moves in relation to the support member  8  and the slider  14 . In other words, when the slider  15  moves in relation to the support member  8  and the slider  14 , the pinion  34  turns together with the output shaft of the motor  32 . Then, at a time when the slider  14  moves in relation to the support member  8  and the slider  15 , the clutch  35  blocks up a power transmission route to the pinion  34  from the motor  32 . In other words, when the slider  14  moves in relation to the support member  8  and the slider  15 , the pinion  34  idly turns in relation to the output shaft of the motor  32 . 
     In this way, when the slider  15  moves in relation to the support member  8  and the slider  14 , the clutch  35  transmits the power of the motor  32  to the slider  15 ; and meanwhile, when the slider  14  moves in relation to the support member  8  and the slider  15 , the clutch  35  blocks up the power transmission route from the motor  32  to the slider  15 . In the present embodiment, by use of the pinion  34 , the clutch  35  and the like, there is structured a power transmission mechanism  36  for transmitting the power of the motor  32  to the slider  15  from the motor  32 . 
     The linear encoder  18  includes a linear scale  38  fixed to the slider  14 , and a sensor  39  fixed to the slider  15 . The linear scale  38  is fixed to the lower surface of the slider  14 . The linear scale  38  is placed in such a way that a longitudinal direction of the linear scale  38  is consistent with a front-and-back direction. Moreover, the linear scale  38  is placed at a left side of the through hole  14   a . A lower surface of the linear scale  38  is made so as to be a bumpy surface where minute bumps are formed in a series. 
     The sensor  39  is an optical sensor of a reflection type, which includes a light emitting element and a light receiving element. The sensor  39  is placed at a lower side of the linear scale  38 ; and a light emitting surface of the light emitting element and a light receiving surface of the light receiving element of the sensor  39  face the lower surface of the linear scale  38 . Provided with, for example, a resolution of 0.1 micrometer (μm), the linear encoder  18  detects a movement distance of the slider  14  in relation to the support member  8 . 
     The retainer mechanism  19  includes a contacting member  40  that can contact the support member  8  with a predetermined contact pressure, and a move mechanism  41  as a contacting member move mechanism that moves the contacting member  40 . The move mechanism  41  is installed to the slider  15 . The move mechanism  41  has a solenoid  42  fixed to the slider  15 , and a lifting member  43  that is connected to the solenoid  42  and lifts up and down with power of the solenoid  42 . The contacting member  40  is shaped so as to be cylindrical, and placed in such a way that an axial direction of the contacting member  40 , being cylindrically shaped, is consistent with a vertical direction. The contacting member  40  is fixed to an upper end part of the lifting member  43 . Then, the contacting member  40  is placed at a position of a lower side of the table  6 , and the position being at an upper side of an upper surface of the slider  14 . 
     The contacting member  40  can be moved between a contacting position, where a top end surface of the contacting member  40  contacts a lower surface of the table  6  with the predetermined contact pressure, and a non-contacting position (a position shown in  FIG. 2 ), where the top end surface of the contacting member  40  is distant from the lower surface of the table  6  so as not to contact the lower surface of the table  6 . In other words, the move mechanism  41  moves the contacting member  40  between the contacting position, where the contacting member  40  contacts the support member  8  with the predetermined contact pressure, and the non-contacting position, where the contacting member  40  is distant from the support member  8  so as not to contact the support member  8 . At a time when the slider  15  moves in relation to the support member  8  and the slider  14  in the front-and-back direction, the contacting member  40  is placed at the non-contacting position; and meanwhile, at a time of retaining the slider  15 , being in a stop state, at a stop position; the contacting member  40  is placed at the contacting position. 
     The detection mechanism  20  includes two sensors  45  and  46  fixed to the slider  14 , and a light-blocking member  47  fixed to the slider  15 . Each of the sensors  45  and  46  is an optical sensor of a light-transmissive type, which has a light emitting element and a light receiving element. The sensors  45  and  46  are fixed to the lower surface of the slider  14 . Moreover to describe, the sensor  45  is fixed to the lower surface of the slider  14 , at a position of a further front side than the through hole  14   a ; and meanwhile, the sensor  46  is fixed to the lower surface of the slider  14 , at a position of a further rear side than the through hole  14   a . The light-blocking member  47  is shaped by use of a metal plate, such as a steel plate and the like. Then, the light-blocking member  47  is shaped so as to be a flat plate. The light-blocking member  47  is provided with a light-blocking part  47   a  for blocking in a space between the light emitting element and the light receiving element of each of the sensors  45  and  46 . 
     In the present embodiment, if the light-blocking part  47   a  blocks in the space between the light emitting element and the light receiving element of the sensor  45  while the slider  15  moves toward a front side in relation to the slider  14 , a stop position of the slider  15  moving toward the front side in relation to the slider  14  is detected so that the motor  32  stops. In the meantime, if the light-blocking part  47   a  blocks in the space between the light emitting element and the light receiving element of the sensor  46  while the slider  15  moves toward a rear side in relation to the slider  14 , a stop position of the slider  15  moving toward the rear side in relation to the slider  14  is detected so that the motor  32  stops. Incidentally, a movement range of the slider  15  is restricted in such a way that, the guide blocks  22  fixed to the slider  14  and the guide block  23  fixed to the slider  15  do not contact each other, even though the slider  15  moves in relation to the slider  14 . 
     (Operation of Ink-Jet Printer) 
     The ink-jet printer  1  carries out printing operation on a print medium by way of alternate repetition of reciprocating the carriage  4  in the main travelling direction (the right-and-left direction) in relation to the Y-bar  5 , and transferring the Y-bar  5  in the sub travelling direction (the front-and-back direction) in relation to the table  6 . At a time of transferring the Y-bar  5  in relation to the table  6  in the front-and-back direction in the printing operation on the print medium; at first, the slider transfer mechanism  17  transfers the slider  15  in the front-and-back direction in relation to the support member  8  and the slider  14 . For example, at the time of transferring the Y-bar  5  toward a front side in relation to the table  6 ; at first, as shown in  FIG. 7 , the slider transfer mechanism  17  transfers the slider  15  to the front side, until the light-blocking part  47   a  blocks in the space between the light emitting element and the light receiving element of the sensor  45 , and then stops the slider  15  there. 
     Subsequently, in a state where the contacting member  40 , having been at the non-contacting position, is moved to the contacting position in order to stop the slider  15 ; as shown in  FIG. 6 , the slider transfer mechanism  16  transfers the slider  14  in relation to the support member  8  and the slider  15 . At the time, the clutch  35  blocks up the power transmission route to the pinion  34  from the motor  32  so that the pinion  34  idly turns in relation to the output shaft of the motor  32  in order to maintain a state of the slider  15  being stopped. Moreover, at the time, the linear encoder  18  detects the movement distance of the slider  14  in relation to the support member  8 . 
     Primary Effect of the Present Embodiment 
     As described above, according to the present embodiment, at the time of transferring the Y-bar  5  in relation to the table  6  in the front-and-back direction in the printing operation on the print medium; the slider  15 , to which the sensor  39  is fixed, is transferred in relation to the support member  8  and the slider  14 ; and subsequently the slider  14 , to which the linear scale  38  is fixed, is transferred in relation to the support member  8  and the slider  15 , while the slider  15  is kept in a state of being stopped. In other words, according to the present embodiment; before transferring the slider  14 , the sensor  39  is transferred together with the slider  15  in relation to the support member  8  and the slider  14 ; and subsequently, the slider  14  is transferred in relation to the support member  8  and the slider  15 , in order to relatively move the linear scale  38  in relation to the sensor  39 . 
     Therefore, according to the present embodiment, even though a distance, through which the slider  14  can move in relation to the support member  8 , is comparatively long, and even though a length of the linear scale  38  is made short, it becomes possible to detect the movement distance of the slider  14  in relation to the support member  8  by use of the linear scale  38  and the sensor  39 . In other words, according to the present embodiment, even though the distance, through which the Y-bar  5  can move in relation to the table  6  on which the print medium is placed, is comparatively long, the movement distance of the Y-bar  5  in relation to the table  6  can be detected, while the length of the linear scale  38  is made short. Therefore, according to the present embodiment, even though a length of the table  6  in the front-and-back direction is long, and even though the slider  14  is able to move in relation to the table  6  in an entire range of the front-and-back direction, it becomes possible to detect the movement distance of the Y-bar  5  in relation to the table  6 , while the length of the linear scale  38  is made short. 
     According to the present embodiment, the pinion  34  is connected to the output shaft of the motor  32  by the intermediary of the clutch  35 , in such a way that the clutch  35  transmits the power of the motor  32  to the pinion  34  when the slider  15  is transferred in relation to the support member  8  and the slider  14 , and the clutch  35  blocks up the power transmission route to the pinion  34  from the motor  32  when the slider  14  is transferred in relation to the support member  8  and the slider  15 . Therefore, according to the present embodiment, at the time when the slider  14  is transferred in relation to the support member  8  and the slider  15 , it becomes possible by way of a comparatively easy way to maintain the slider  15 , in the state of being stopped, at the stop position. 
     According to the present embodiment, the sliding mechanism  10  includes the retainer mechanism  19  that retains the slider  15 , in the state of being stopped, at the stop position. Therefore, according to the present embodiment, it becomes possible to transfer the slider  14  in relation to the support member  8  and the slider  15 , in the state where the slider  15  is stopped for sure. Therefore, according to the present embodiment, detection accuracy of the linear encoder  18  can be enhanced. Moreover, according to the present embodiment, since the sliding mechanism  10  includes the detection mechanism  20  for detecting the stop position of the slider  15  in relation to the slider  14 , the slider  15  can automatically be stopped, on the basis of a detection result of the detection mechanism  20 . 
     According to the present embodiment, the guide block  22  fixed to the slider  14  and the guide block  23  fixed to the slider  15  are engaged with the guide rail  21  in common, in such a way as to be slidable. Therefore, according to the present embodiment, being compared to a case where a guide rail with which the guide block  22  is engaged, and another guide rail with which the guide block  23  is engaged, are separately prepared; the structure of the sliding mechanism  10  in the present embodiment can be simplified. 
     Other Embodiments 
     Though the embodiment described above is an example of a preferred embodiment according to the present disclosure, the present disclosure is not restricted to the embodiment; and various modifications can be made within a scope having no alteration in the gist of the present disclosure. 
     In the embodiment described above, the linear scale  38  may be fixed to the slider  15 , while the sensor  39  is fixed to the slider  14 . Furthermore, in the embodiment described above, the motor  32  may be fixed to the slider  15 , while the rack  33  is fixed to the slider  14 . Nevertheless, the length of the linear scale  38  in the front-and-back direction is longer than the length of the sensor  39  in the front-and-back direction; and therefore, as mentioned in the embodiment described above, preferably the linear scale  38  should be fixed to the slider  14 , with the sensor  39  being fixed to the slider  15 , so that it becomes possible to downsize the slider  15 . Moreover, as mentioned in the embodiment described above, preferably the motor  32  should be fixed to the slider  14 , with the rack  33  being fixed to the slider  15 , so that it becomes possible to downsize the slider  15 . 
     In the embodiment described above, a guide rail with which the guide block  23  is engaged may be fixed to the slider  14 . Moreover, in the embodiment described above, the slider transfer mechanism  17  may be provided, not with the rack  33  and the pinion  34 , but alternatively with a ball screw; and may be provided with a belt fixed to the slider  15 , and two pulleys over which the belt is placed. 
     In the embodiment described above, with the motor  32  being fixed to the slider  15 , the rack  33  may be fixed to the support member  8 . In other words, according to the embodiment described above, with the motor  32  being installed to the slider  15 , the power transmission mechanism  36  may transmit power of the motor  32  to the support member  8  from the motor  32 . In this case, the clutch  35  becomes unnecessary. Incidentally, while the rack  33  together with the slider  14  and the slider  15  can be transferred in relation to the support member  8  in the embodiment described above; in this case, the rack  33  cannot be transferred in relation to the support member  8 ; and therefore, the length of the rack  33  in the front-and-back direction becomes long. In other words, the power transmission mechanism  36  increases in size. 
     In the embodiment described above, the printer  1  may be a shaping device that shapes a three-dimensional article on the table  6 . In this case, the printer  1  is provided, for example, with a lifting mechanism for lifting up and down the table  6 . Furthermore, the sliding mechanism  10  to which the present disclosure is applied may be used for any device other than the printer  1 .