Patent Publication Number: US-8540341-B2

Title: Maintenance device, power transmission switching device, and liquid ejecting apparatus

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     The entire disclosure of Japanese Patent Application Nos. 2011-45367, filed Mar. 2, 2011, and 2011-45366, filed Mar. 2, 2011 are expressly incorporated by reference herein. 
     BACKGROUND 
     1. Technical Field 
     The present invention relates to a maintenance device which performs maintenance of a liquid ejecting head, a liquid ejecting apparatus including the maintenance device, a power transmission switching device which switches power transmission from a driving source, and a liquid ejecting apparatus including the power transmission switching device. 
     Hitherto, an ink jet type printer has been widely known as a kind of liquid ejecting apparatus. This printer is provided with a liquid ejecting head in a carriage which is reciprocated, and performs printing by ejecting ink which is an example of a liquid from nozzles which are open to a nozzle formation surface of the liquid ejecting head onto a medium such as a sheet transported in a direction intersecting a movement direction of the carriage. 
     In such a printer, in general, maintenance for maintaining ejection characteristics for appropriately ejecting ink from the nozzles of the liquid ejecting head, that is, maintenance of the liquid ejecting head is performed. For example, after the carriage is moved to a non-printing area other than a printing area where the ink is ejected onto the sheet for printing, a cap is caused to abut on the nozzle formation surface of the liquid ejecting head so as to cover the opening portions of the nozzles. In addition, by causing a cap internal space formed between the nozzle formation surface and the cap in the abutting state to be in a negative pressure state through a rotating operation of a suction pump, for example, ink thickened in the nozzles is suctioned from the nozzles and is discharged via a tube which is a suction passage connected to the cap. In this manner, maintenance for appropriately ejecting ink from the nozzles is performed. 
     In this maintenance, the printer may select nozzles that need to be suctioned for maintenance. That is, for example, the nozzle formation surface is partitioned into a plurality of areas in units of nozzle rows according to colors of ink ejected from the nozzles constituting the nozzle rows, and each of the partitioned areas is covered with the cap. In addition, by causing the cap internal space formed with an area in the nozzle formation surface covered with the cap to be in the negative pressure state, the nozzles formed in the area are subjected to the maintenance. 
     As a printer having such a configuration, in JP-A-2010-201911, a technique for selecting and squeezing a tube by a blocking member which is provided in a liquid ejecting head and is reciprocated as a carriage is reciprocated, and selecting a cap internal space to be in a negative pressure state is suggested. According to the technique of JP-A-2010-201911, since the reciprocation of the carriage is used, it is possible to selectively block tubes which are suction passages without enlarging a movement range of the carriage. Therefore, without an increase in size, a printer capable of selectively suctioning a plurality of cap internal spaces is obtained. 
     Besides, a process for wiping unnecessary ink that is adhered to opening portions of the nozzles using a wiping member that is raised so as to be engaged with the liquid ejecting head, and the like are performed. In addition, as a driving source for rotating such a suction pump or raising the wiping member, a typical motor is used. 
     Therefore, when a plurality of operations can be performed by a single motor, the number of motors (driving sources) used can be reduced, and thus it is possible to suppress an increase in the size of the printer. Here, for example, in JP-A-6-115096, a printer is disclosed which switches a gear that is engaged with a driving gear of a motor to any driving gear of a gear for driving a paper feeding mechanism that transports a sheet and a gear for driving a suction mechanism that drives a suction pump, using a moving operation of a carriage in areas other than a printing area, which are on both sides of a sheet. As such, by switching transmission of rotation power of a single motor using the moving operation of the carriage in the areas other than the printing area, the rotation driving of the single motor can be switched without an additional power transmission switching device, thereby further suppressing the increase in the size of the printer. 
     However, in the suggested technique of JP-A-2010-201911, the blocking member is moved along with the reciprocation of the carriage in a non-printing area in which a cap abuts on the liquid ejecting head and forms the cap internal space. Therefore, the carriage cannot be moved while maintaining the state where the squeezed tube is selected. In addition, when the carriage is moved to the non-printing area from the printing area, as the cap is raised by operating a raising mechanism using the movement of the carriage as a driving force, the cap abuts on the nozzle formation surface. 
     Therefore, in JP-A-2010-201911, in a case where so-called idle suction is performed for suctioning the inside of the cap while the cap is separated from the nozzle formation surface, when the carriage is moved in a direction to the printing area from the non-printing area so as to lower the cap, the blocking member is accordingly moved in the direction to the printing area as such. As a result, the state of selectively squeezing the tube which is the suction passage is released, so that the insides of all the caps are suctioned at the same time and thus suction force is dispersed. Therefore, there is a problem in that discharging characteristics of the ink in the caps are degraded. In addition, during the reciprocation of the carriage in the non-printing area, in addition to a load caused by the raising movement of the cap, a load caused by the reciprocation of the blocking unit is increased. Therefore, there is a concern that an excessive load is applied to the motor for reciprocating the carriage. Accordingly, there is also a problem in that the motor for use has to be a large motor which has a high rated current so as to obtain a high torque. 
     In addition, in the suggested technique of JP-A-6-115096, the driving gear for the suction mechanism can be driven only in the state where the carriage is positioned in an area other than the printing area. That is, for example, in the case where the carriage is moved to the printing area, there is a problem in that the driving gear of the motor is not maintained in the switched state of driving the driving gear for the suction mechanism and returns to the state of being always engaged with the driving gear of the paper feeding mechanism. 
     SUMMARY 
     An advantage of some aspects of the invention is that it realizes a maintenance device capable of moving a carriage while suppressing an increase in a load during movement of the carriage and maintaining a state where a cap internal space is selected to be in a negative pressure state, and provides a liquid ejecting apparatus including the maintenance device. 
     In addition, another advantage of some aspects of the invention is that it realizes a power transmission switching device capable of reliably switching transmission of power of a driving source using a moving operation of the carriage and maintaining the switched power transmission state, and provides a liquid ejecting apparatus including the power transmission switching device. 
     According to an aspect of the invention, there is provided a maintenance device including: a carriage which is provided to support a liquid ejecting head that ejects a liquid from a plurality of nozzles and to be reciprocated; a cap which approaches the liquid ejecting head as the carriage is moved to a maintenance position where maintenance of the liquid ejecting head is performed, abuts on the liquid ejecting head so as to surround the nozzles, and forms a plurality of internal spaces between the cap and the liquid ejecting head; a suction unit which suctions each of the internal spaces of the cap via a suction passage corresponding to each of the internal spaces; a selective blocking unit which has a movement member which is moved by being linked with the carriage in a state of being engaged with the carriage in a movement midway area positioned on the path of the carriage moving to the maintenance position, selectively blocks the suction passages according to movement of the movement member, and releases engagement between the movement member and the carriage while maintaining a blocked state of the selected suction passage; and a separation and approach movement unit which establishes or releases the engagement between the movement member and the carriage by moving the movement member so as to approach or be separated from the carriage. 
     According to this configuration, in the area which is on the path of the movement to the maintenance area where suction is performed by causing the cap to abut thereon, the internal space of the cap is selected to be in a negative pressure state, and the carriage can be moved to the maintenance area while maintaining the blocked state of the suction passage corresponding to the selected internal space. As a result, maintenance of the liquid ejecting head can be appropriately performed without a reduction in the suction characteristics of the cap. In addition, when the movement midway area where the suction passage to be blocked is selected is caused not to overlap with an area where the carriage is moved to abut on the liquid ejecting head, an increase in the load caused by the movement of the carriage can be suppressed. 
     In the maintenance device according to the aspect of the invention, the movement member may be provided with an engagement portion that is able to be engaged with the carriage in the movement midway area of the carriage and a blocking member that is displaced so as to selectively block the suction passages, the selective blocking unit may include a cam member having a cam surface formed to guide the blocking member to a selection position corresponding to the selection of the suction passage to be blocked according to reciprocation of the movement member, and the separation and approach movement unit may drive the selective blocking unit to approach or be separated from the carriage in a state where the blocking member is positioned at the selection position. 
     According to this configuration, since the position of the movement member in the case where the engagement between the carriage and the movement member is released is specified by selection positions, when the engagement portion of the movement member is engaged with the carriage thereafter, the carriage can be easily engaged with the engagement portion. In addition, by switching the suction passage to be blocked by reciprocation of the movement member, the selection positions can be the same position in the movement direction of the movement member. Therefore, regardless of the selected state of the suction passage, the carriage and the movement member can be engaged with each other at a fixed position in the movement midway area. 
     In the maintenance device according to the aspect of the invention, an impelling unit which impels the movement member so as to guide the blocking member toward the selection position may further be included. 
     According to this configuration, when the engagement between the carriage and the movement member is released, the movement member is impelled by the impelling unit so that the blocking member is moved to a direction of the selection positions. As a result, for example, in the case where the engagement between the carriage and the movement member is released on the path of the movement of the carriage, the position of the movement member is moved to a position that can be specified in the movement direction of the movement member by the impelling unit, so that in the case where the engagement portion of the movement member is engaged with the carriage, the carriage can be easily engaged with the engagement portion. 
     In the maintenance device according to the aspect of the invention, in the selective blocking unit, a movement restriction unit which restricts the movement of the movement member in a direction in which the carriage is moved from the maintenance area to the movement midway area may be formed at the selection position to which the blocking member is guided. 
     According to this configuration, by engaging the carriage moved to the maintenance area with the engagement portion of the movement member in the movement restricted state by the selective blocking unit, the carriage can be restricted so as not to move in the direction toward the movement midway area from the maintenance area. Therefore, the engagement portion of the movement member can be caused to function as a lock unit of the carriage. 
     In the maintenance device according to the aspect of the invention, the movement midway area of the carriage may include an area where the liquid is ejected onto a medium from the liquid ejecting head. 
     According to this configuration, during the process of ejecting the liquid onto the medium, using the moving operation of the carriage, the internal space of the cap to be suctioned can be selected in advance. Therefore, after ending printing, nozzles which are objects of maintenance can be immediately suctioned for maintenance. 
     According to another aspect of the invention, there is provided a liquid ejecting apparatus including: a liquid ejecting head which ejects a liquid onto a medium; and the maintenance device having the configurations described above. 
     In the liquid ejecting apparatus having this configuration, the same effects as those of the maintenance device are exhibited. That is, the cap of which the internal space is to be suctioned is selected using the reciprocation of the carriage while suppressing an increase in the load of the driving source, so that the liquid ejecting head can be subjected to maintenance without degradation of suction characteristics. 
     According to still another aspect of the invention, there is provided a power transmission switching device including: a rotation unit which is rotated as a driving source is rotated; a rotation shaft which has a shaft portion extending along an axial direction of the rotation unit and in which a protruding portion protruding in a direction intersecting the axial direction of the shaft portion is formed; an engagement member in which a first engagement portion and a second engagement portion that are able to be engaged with the protruding portion in a rotation direction of the rotation shaft are formed at positions separated in the axial direction, and which allows relative rotation of the protruding portion so as to cause the protruding portion to be engaged with any of the first and second engagement portions by being moved in a first direction along the axial direction, and maintains engagement between the protruding portion and any of the first and second engagement portions so as to be rotated along with the protruding portion by being moved in a second direction opposite to the first direction; a displacement member which abuts on the engagement member and is displaced so as to move the engagement member to a position where the rotation of the protruding portion is allowed in the first direction along the axial direction; a clutch member which is moved in the first direction and is engaged with the rotation unit as the displacement member is moved, so as to receive the rotation of the rotation unit and be rotated about the rotation shaft, and is moved along the axial direction so as to maintain engagement with the rotation unit when the protruding portion is engaged with the second engagement portion and so as to release the engagement with the rotation unit when the protruding portion is engaged with the first engagement portion; and a second direction impelling member which impels the clutch member in the second direction. 
     According to this configuration, by displacing the displacement member, the clutch member can be caused to be rotatably driven or not to be rotatably driven by the driving force from the driving source. Therefore, for example, when the clutch member is moved in the axial direction by moving the displacement member using the moving operation of the carriage, whether or not the power of the driving source is transmitted can be switched between by absence or presence of the rotation of the clutch member. In addition, the engagement member is impelled so that the state of engagement between the protruding portion and any of the first and second engagement portions is always maintained by the second direction impelling unit via the clutch member. Therefore, the power transmission state of the switched driving source can be maintained regardless of the movement position of the carriage. 
     In the power transmission switching device according to the aspect of the invention, the displacement member may be a lever member which is displaced so as to move the engagement member in the first direction as one end side thereof is moved and thus the other end side thereof abuts on the engagement member. 
     According to this configuration, for example, the engagement member can be pressed using the moving operation of the carriage that is moved at a position distant from the power transmission switching device. In addition, the engagement member can be moved in the reverse direction to the movement direction of the carriage. Moreover, in the case where the one end side is moved by the movement of the carriage, an increase in the load that occurs when the carriage is moved with respect to the load of the other end side for moving the engagement member can be suppressed. 
     In the power transmission switching device according to the aspect of the invention, a first direction impelling member may further be included which is inserted between the clutch member and the engagement member, impels the clutch member in the first direction with an impelling force stronger than that of the second direction impelling member by being compressed, thereby moving the clutch member in the first direction along with the engagement member against the impelling force of the second direction impelling member. 
     According to this configuration, for example, even in a case where the clutch member is in a state of abutting on a position where it is not engaged with the rotation unit so as not to move in the first direction before moving to a position where it can be engaged with the rotation unit during the movement in the first movement, the clutch member can be reliably engaged with the rotation unit in the rotation direction in the following manner. That is, when the engagement member is moved in the first direction approaching the clutch member by the displacement member, the first direction impelling member is in a compressed state, and when the rotation unit and the clutch member are caused to rotate relative to each other in this state, the state of the clutch member abutting on the position where it is not engaged with the rotation unit is released. Then, the clutch member is moved in the first direction as the compressed first direction impelling member is elongated, such that the rotation unit and the clutch member can be engaged with each other in the rotation direction. 
     In the power transmission switching device according to the aspect of the invention, in the rotation unit, a driving-side protruding portion protruding toward the clutch member side from the rotation unit side along the axial direction may be formed, and in the clutch member, a driven-side protruding portion may be formed which protrudes toward the rotation unit side from the clutch member side along the axial direction, and is rotated by being engaged with the driving-side protruding portion when the rotation unit is rotated about the rotation shaft. 
     In this configuration, through the movement of the clutch member in the first direction, the driven-side protruding portion is moved in the axial direction of the rotation shaft so as to be engaged with the driving-side protruding portion in the rotation direction, so that driving transmission between the rotation unit and the clutch member can be performed. Therefore, since the movement amount in the axial direction is enough for the occupied space needed for the engagement, the space needed for the engagement is suppressed, and rotation is transmitted by the engagement between the protruding portions, so that the possibility that rotation is stably transmitted is increased. 
     In the power transmission switching device according to the aspect of the invention, the clutch member may be provided with a spur gear which is rotated about the rotation shaft in synchronization with rotation of the clutch member, a slide member which is engaged with the spur gear and in which a linear gear that is moved along the direction intersecting the axial direction as the spur gear is rotated is formed in a partial area range may be provided, and teeth of the linear gear positioned at least at an end of the partial area range may be impelled in a direction to be engaged with the spur gear so as to always maintain engagement with the spur gear. 
     According to this configuration, the power of the driving source is transmitted by the rotation of the clutch member as needed so as to reliably move the slide member. Therefore, for example, in a case where an object member is moved upward and downward by the slide member, the slide member can be reliably moved to move the object member upward and downward without being limited by the movement position of the carriage. 
     In the power transmission switching device according to the aspect of the invention, the slide member may have an elastic deformation portion which is elastically deformed along with movement, and may be impelled in the direction to be engaged with the spur gear so as to cause the linear gear to always maintain the engagement with the spur gear by a restoring force of the elastic deformation portion. 
     According to this configuration, the slide member is formed in one body without an impelling unit being configured as an additional component, so that the power transmission switching device can be suppressed from being complicated. 
     According to a yet another aspect of the invention, there is provided a liquid ejecting apparatus including: a liquid ejecting head which ejects a liquid onto a medium; a carriage which is configured to be provided with the liquid ejecting head and to be reciprocated; and the power transmission switching device having the configuration described above. 
     According to the liquid ejecting apparatus having the configuration described above, the same effects as those of the power transmission switching device are exhibited. In particular, using the movement of the carriage, a member that transmits the power of the driving source for driving can be switched. 
    
    
     
       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 schematic configuration of a printer having a maintenance device according to an embodiment of the invention. 
         FIG. 2  is a schematic configuration diagram of the maintenance device of the embodiment. 
         FIG. 3  is a perspective view of the maintenance device of the embodiment. 
         FIG. 4  is a perspective view of the maintenance device viewed obliquely from above in a left forward direction in a state where a frame is excluded. 
         FIG. 5  is a perspective view of the maintenance device viewed obliquely from below in a right rearward direction in the state where the frame is excluded. 
         FIG. 6  is a perspective view illustrating the configurations of an elevation mechanism and a clutch mechanism of a wiper and a lock lever. 
         FIG. 7A  is a front view illustrating the state of the elevation mechanism where the wiper and the lock lever are at retreat positions, and  FIG. 7B  is a schematic cross-sectional view taken along the line VIIB-VIIB in  FIG. 7A . 
         FIG. 8A  is a front view illustrating the state of the elevation mechanism where the lock lever is a lock position, and  FIG. 8B  is a schematic cross-sectional view taken along the line VIIIB-VIIIB in  FIG. 7A . 
         FIG. 9A  is a front view illustrating the state of the elevation mechanism where the wiper is at a wiping position and the lock lever is at the retreat position, and  FIGS. 9B and 9C  are schematic cross-sectional views taken along the line IXB-IXB in  FIG. 7A . 
         FIG. 10  is an exploded perspective view illustrating constituent components in the clutch mechanism. 
         FIG. 11  is a front view illustrating constituent components related to the clutch mechanism in an OFF state as viewed from the front. 
         FIG. 12  is a front view illustrating constituent components related to the clutch mechanism in a state of being switched from the OFF state to an ON state as viewed from the front. 
         FIG. 13  is a perspective view illustrating the configuration of a mechanism for switching the clutch mechanism from the OFF state to the ON state. 
         FIG. 14  is a perspective view illustrating a state where the clutch mechanism is switched from the OFF state to the ON state. 
         FIG. 15  is a front view illustrating the constituent components related to the clutch mechanism in the ON state as viewed from the front. 
         FIG. 16  is a perspective view illustrating an elevation mechanism of a selective blocking unit. 
         FIGS. 17A and 17B  are diagrams illustrating a state where a carriage and the selective blocking unit are engaged, and are front views respectively illustrating the selective blocking unit before being raised and the selective blocking unit after being raised as viewed from the right. 
         FIG. 18A  is a perspective view illustrating the configuration of a rack slider of this embodiment, and  FIG. 18B  is a cross-sectional view taken along the line XVIIIB-XVIIIB in  FIG. 18A . 
         FIG. 19  is a perspective view illustrating the elevation mechanism of the selective blocking unit in a state where the selective blocking unit is raised. 
         FIG. 20  is a perspective view illustrating the selective blocking unit in a state where a slider is detached. 
         FIG. 21  is a plan view illustrating a rotation state of a blocking member in a cam surface as viewed from above. 
         FIG. 22  is a perspective view illustrating a blocking mechanism of a tube. 
         FIG. 23  is a process flowchart showing a switching process of the clutch mechanism in the embodiment. 
         FIG. 24  is a plan view illustrating a movement position of the carriage with respect to the maintenance device in a state where power transmission can be switched in the clutch mechanism as viewed from above. 
         FIG. 25  is a plan view illustrating a movement position of the carriage with respect to the maintenance device in a state where an engagement portion of the slider and a concave portion of the carriage are engaged as viewed from above. 
         FIG. 26  is a plan view of the maintenance device including a selective blocking unit of a modified example as viewed from above. 
         FIG. 27A  is a schematic view illustrating a modified example of the selective blocking unit, and  FIG. 27B  is a schematic view illustrating a blocked state of a tube in  FIG. 27A . 
         FIG. 28  is a perspective view schematically illustrating another modified example of the selective blocking unit. 
         FIG. 29  is a perspective view illustrating a rack slider of a modified example. 
         FIG. 30  is a perspective view illustrating a clutch body of a modified example. 
         FIG. 31  is a front view illustrating a clutch mechanism of a modified example as viewed from the front. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Embodiments that embody the invention as an ink jet type printer which is an example of a liquid ejecting apparatus will now be described with reference to the drawings. For ease of the following description, as illustrated in  FIG. 1 , the direction of gravity in the vertical direction is a downward direction, and a direction opposite to the direction of gravity is an upward direction. In addition, a transportation direction which intersects the vertical direction and in which a sheet P fed to a printer is transported during image formation is a forward direction, and a direction opposite to the transportation direction is a rearward direction. Moreover, directions which intersect both the vertical direction and transportation direction and in which a carriage is reciprocated, that is, scanning directions are respectively a right direction and a left direction as viewed from the forward direction. 
     As illustrated in  FIG. 1 , in a printer  11  as a liquid ejecting apparatus, at a lower part in a frame  12  having a substantially rectangular box shape, a support member  13  extends for supporting a sheet P which is an example of a medium along the longitudinal direction during printing. In addition, on the support member  13 , according to driving of a paper feeding motor  14  provided under the rear surface of the frame  12 , the sheet P is fed by a paper feeding mechanism (not shown) from the rearward side to the forward side on the support member  13 . 
     Above the support member  13  in the frame  12 , a guide shaft  15  is provided along the longitudinal direction of the support member  13 . A carriage  16  is supported by the guide shaft  15  so as to reciprocate along the axial direction of the guide shaft  15 . That is, the carriage  16  is provided with a support hole  16   a  so as to penetrate the guide shaft  15  in the axial direction, and the guide shaft  15  is inserted through the support hole  16   a . Therefore, the carriage  16  is supported so as to reciprocate in the axial direction of the guide shaft  15 , that is, the scanning direction (the left and right direction). 
     On the inner surface of the rear wall of the frame  12 , at positions corresponding to both end portions of the guide shaft  15 , a driving pulley  17   a  and a driven pulley  17   b  are rotatably supported. An output shaft of a carriage motor  18  which is a driving source to reciprocate the carriage  16  is connected to the driving pulley  17   a , and an endless type timing belt  17  of which a part is connected to the carriage  16  is suspended between the driving pulley  17   a  and the driven pulley  17   b . Therefore, the carriage  16  is moved in the axial direction of the guide shaft  15  (the left and right direction) via the endless type timing belt  17  by driving force of the carriage motor  18  while being guided by the guide shaft  15 . 
     The lower surface of the carriage  16  is provided with a liquid ejecting head  19 , and ink cartridges  20  for supplying a plurality of colors (in this embodiment, four colors including black, cyan, yellow, and magenta) of ink to the liquid ejecting head  19  are detachably mounted on the carriage  16 . 
     On the lower surface of the liquid ejecting head  19 , a plurality of (in this embodiment, four) nozzle rows  22 A to  22 D (see  FIG. 2 ) in which a plurality of nozzles are lined up in the forward and rearward direction are arranged in parallel in the left and right direction. In this embodiment, regarding the nozzle rows  22 A to  22 D, the nozzle rows  22 A,  22 B,  22 C, and  22 D are sequentially arranged from the left side. In addition, the ink in the ink cartridge  20  is supplied from the ink cartridge  20  to the liquid ejecting head  19  by driving of a pressurizing unit such as a piezoelectric element (not shown) included in the liquid ejecting head  19 , and is ejected from the nozzles of the nozzle rows  22 A to  22 D included in the liquid ejecting head  19 . 
     That is, as illustrated in  FIG. 1 , in the printer  11 , an area corresponding to the support member  13  on which the sheet P is supported during transportation is a printing area PA. In addition, while the carriage  16  is reciprocated in the left and right direction in the printing area PA, the piezoelectric element (not shown) provided in the liquid ejecting head  19  is driven, such that the ink is ejected onto the sheet P fed onto the support member  13 , thereby performing printing. In this case, black ink is ejected from each of the nozzles constituting the nozzle row  22 A, cyan ink is ejected from each of the nozzles constituting the nozzle row  22 B, yellow ink is ejected from each of the nozzles constituting the nozzle row  22 C, and magenta ink is ejected from each of the nozzles constituting the nozzle row  22 C. 
     However, in this embodiment, a non-printing area deviated from the printing area PA which is positioned on the right from left and right sides of the support member  13  is a maintenance area MA for performing maintenance of the liquid ejecting head  19  such as cleaning. The liquid ejecting head  19  is moved to a predetermined position in the maintenance area MA, and a maintenance device  23  that maintains ink ejection characteristics of the nozzles is provided. 
     The maintenance device  23  is raised as the carriage  16  is moved to the maintenance area MA and has a cap  27  which is in a state of abutting on the liquid ejecting head  19  so as to surround the nozzles in the maintenance area MA. In addition, in the abutting state, a plurality of (here, two) internal spaces (hereinafter, referred to as “cap internal spaces”) formed between the liquid ejecting head  19  and the cap  27  are suctioned via flexible tubes which are suction passages for pressure reduction, and ink is suctioned from the nozzles so as to maintain the liquid ejecting head  19 . When the ink is suctioned, the maintenance device  23  of this embodiment has a plurality of (here, two) suction passages for the respective cap internal spaces, and includes a selective blocking unit (selective blocking unit)  40  that blocks the suction passages by squeezing the tubes according to selection of the cap internal space to be subjected to pressure reduction. 
     Next, the maintenance device  23  of this embodiment will be specifically described. 
     First, the schematic configuration of the maintenance device  23  will be described with reference to  FIG. 2 . In addition, in  FIG. 2 , the left side from the broken lines schematically illustrates the maintenance device  23  in a state where the carriage  16  is moved in the left and right direction, and the right side from the broken lines schematically illustrates the maintenance device  23  in a state where the carriage  16  is moved in a direction perpendicular to the figure. 
     As illustrated in  FIG. 2 , in the cap  27 , a partition wall  30  partitions the inside of the cap  27  into left and right two chambers. In the cap  27 , a part on the left with respect to the partition wall  30  is a first cap portion  31 , and a part on the right with respect to the partition wall  30  is a second cap portion  32 . In addition, in a state where the carriage  16  is moved to an upward position of the maintenance device  23  in the maintenance area PA and the cap  27  is raised, the first cap portion  31  surrounds the nozzle row  22 A and forms the first cap internal space  31   a  with the liquid ejecting head  19 . In addition, the second cap portion  32  surrounds the nozzle rows  22 B to  22 D and forms the second cap internal space  32   a  with the liquid ejecting head  19 . 
     A first protruding portion  33  protrudes downward from the bottom wall of the first cap portion  31 , and a first discharge path  33   a  for discharging the ink from the first cap portion  32  is formed to penetrate the first protruding portion  33  in the upward and downward direction. On the other hand, a second protruding portion  34  protrudes downward from the bottom wall of the second cap portion  32 , and a second discharge path  34   a  for discharging the ink from the second cap portion  31  is formed to penetrate the second protruding portion  34  in the upward and downward direction. 
     The base end side (upstream side) of a second discharge tube  37  as a tube having flexibility is connected to the second protruding portion  34 , and the other end side (downstream side) of the second discharge tube  37  is inserted into a waste ink tank  36  having a rectangular parallelepiped shape. On the other hand, the base end side (upstream side) of a first discharge tube  35  as a tube having flexibility is connected to the first protruding portion  33 , and the other end side (downstream side) of the first discharge tube  35  is connected to a confluence point G provided on the path of the second discharge tube  37  so as to join the second discharge tube  37 . 
     Both the discharge tubes  35  and  37  are lined up and drawn to the confluence point G. In addition, at a position of the second discharge tube  37  at the downstream end from the confluence point G with the first discharge tube  35 , a single tube pump  38  is disposed as a suction unit for suctioning the insides of the first and second discharge tubes  35  and  37  from the cap  27  side to the waste ink tank  36  side. 
     That is, in a case where the tube pump  38  is driven, both the discharge tubes  35  and  37  are suctioned at the same time. Therefore, the first and second discharge tubes  35  and  37  form the suction passages for respectively suctioning the first and second cap internal spaces  31   a  and  32   a.    
     In addition, as the tube pump  38  is driven while the cap  27  is raised and abuts on the liquid ejecting head  19 , cleaning of the nozzles is performed. That is, thickened ink is suctioned from each of the nozzles constituting the nozzle rows  22 A to  22 D along with bubbles and the like and is discharged into the waste ink tank  36  via the cap  27  and both the discharge tubes  35  and  37 . In addition, in the waste ink tank  36 , a waste ink absorbing material  39  that absorbs and holds the ink discharged into the waste ink tank  36  is accommodated. 
     At positions of both the discharge tubes  35  and  37  on the upstream side from the confluence point G, the selective blocking mechanism  40  that can selectively block the discharge tubes  35  and  37  is disposed. The selective blocking mechanism  40  includes a base  60  and a slider  41  as a movement member that slides with respect to the base  60 . 
     In the slider  41 , an engagement portion  42  which is engaged with the carriage  16  in the scanning direction (the left and right direction) by being raised and entering a concave portion  16   h  provided on the lower surface side of the carriage  16  from below, and a blocking member  43  which is axially supported to rotate on the lower surface side of the slider  41  for blocking the suction passage are provided. In addition, a cam member  50  which has a cam surface on one surface is embedded in the base  60 , and a surface (upper surface) opposing the blocking member  43  is the cam surface. In addition, with the movement of the slider  41  which is linked with the carriage  16  that moves in the scanning direction as the engagement portion  42  is engaged with the concave portion  16   h  of the carriage  16 , the blocking member  43  is guided by the cam surface and moved so as to squeeze the second discharge tube  37  or the first discharge tube  35 , such that any one of the suction passages is blocked. 
     Although not shown in  FIG. 2 , in the maintenance device  23  of this embodiment, a separation and approach movement unit which is driven by a driving source and moves the slider  41  (the selective blocking mechanism  40 ) to approach and be separated from the carriage  16  is included. Moreover, a power transmission switching device which switches between a state where power of the driving source is transmitted to the separation and approach movement unit and a state where power is not transmitted is included. The power transmission switching device performs switching to transmit the power of the driving source to the separation and approach movement unit so as to raise and lower the selective blocking mechanism  40 , such that the slider  41  is moved by being linked with the carriage  16  in an area on the path of the carriage  16  moving to the maintenance area MA. Hereinafter, the detailed configuration of the maintenance device  23  including the separation and approach unit and the power transmission switching device will be described with reference to the drawings. 
     As illustrated in  FIG. 3 , the maintenance device  23  of this embodiment includes the cap  27  described above, the selective blocking mechanism  40 , the tube pump  38 , a wiper  75  that wipes the liquid ejecting head  19 , and a lock lever  84  that restricts the movement of the carriage  16 . These components are supported or fixed by a frame body  29  that is the base of the apparatus and is made of a resin and are driven by a single motor  26  as a driving source so as to perform their respective predetermined operations in the maintenance device  23 . In this embodiment, switching of each of an elevating operation of the cap  27  and a reciprocating operation of the slider  41  are performed according to the movement of the carriage  16 . In addition, elevating operations of the wiper  75 , the lock lever  84 , and the selective blocking mechanism  40  are also performed by the driving force of the motor  26 . Moreover, a rotating operation of the tube pump  38  is also performed by the motor  26 . Next, structures for performing these operations will be sequentially described. 
     The cap  27  is held by a substantially box-shaped cap holding member  71  provided substantially at the center part of the maintenance device  23  via an elastic member (not shown). The cap holding member  71  is guided by frame walls  29   a  which are erected in front and rear thereof in the upward and downward direction and extend in the left and right direction, can be moved in the left and right direction, and is raised as it moves from the left to the right. 
     Specifically, in the frame walls  29   a , two groups of two penetration grooves  28  which are lined up so as to oppose each other in the forward and rearward direction, a total of four penetration grooves  28 , are provided at different positions in the left and right direction. Each of the penetration grooves  28  includes a lower side flat portion  29   b  extending straight from the left to the right, an inclined surface portion  29   c  extending obliquely upward to the right from the right end of the lower side flat portion  29   b , and an upper side flat portion  29   d  extending straight from the right end of the inclined surface portion  29   c  to the right. In addition, in each of the penetration grooves  28 , the lower side flat portion  29   b , the inclined surface portion  29   c , and the upper side flat portion  29   d  communicate with each other. 
     In the cap holding member  71 , support bars  72  extending in the forward and rearward direction so as to enter the respective penetration grooves  28 , a total of four support bars  27 , are provided so as to correspond to the respective penetration grooves  28 . In addition, each of the support bars  72  enters and is inserted into the corresponding penetration groove  28  so as to be slidable. Therefore, the cap holding member  71  is configured so that as the cap holding member  71  abuts on the right surface of the carriage  16  and moves from the left to the right, the support bars  72  slide on the penetration grooves  28  from the left to the right, pass through the lower side flat portions  29   b  and the inclined surface portions  29   c , and move to the upper side flat portions  29   d  so as to be raised. 
     The cap holding member  71  is always impelled against the right side by a coil spring  74  (see  FIG. 5 ), and in a printing state in which the carriage  16  is not positioned in the maintenance area MA, each of the support bars  72  is positioned at the lower side flat portion  29   b  which is at the left end of the penetration groove  28  by the impelling force of the coil spring  74 . Therefore, the cap holding member  71  is in a state of being lowered in the case where the carriage  16  is positioned in the printing area PA. In addition, when the carriage  16  is moved from the left to the right so as to move from the printing area PA toward the maintenance area MA, the right surface of the carriage  16  abuts on a locking portion  71   a  which is at the right end of the cap holding member  71  and in which a convex portion having a concave surface on the left is formed in the upward and downward direction and thereafter moves together with the cap holding member  71  to the right. 
     With the movement to the right, in a procedure in which each support bar  72  provided in the cap holding member  71  slides to the right on the inclined surface portion  29   c  in the corresponding penetration groove  28 , the support bar  72  is gradually raised so that the cap  27  approaches the liquid ejecting head  19  along with the cap holding member  71 . In addition, in a stage in which each support bar  72  reaches the upper side flat portion  29   d  of the corresponding penetration groove  28 , the cap  27  abuts on the liquid ejecting head  19 . 
     In the cap holding member  71 , in the state where the carriage  16  is moved to the maintenance area MA positioned on the right of the support member  13 , each support bar  72  is positioned at the upper side flat portion  29   d  in the corresponding penetration groove  28  along with the cap  27 . Therefore, a load needed to move the carriage  16  is increased in the procedure in which each support bar  72  slides to the right on the inclined surface portion  29   c  in the corresponding penetration groove  28 . 
     In addition, in the maintenance device  23 , the selective blocking mechanism  40  is disposed at a position on the forward side from the cap holding member  71 . In the selective blocking mechanism  40 , the base  60  is fixed to the frame body  29 , and in the base  60 , the slider  41  is provided which slides in the left and right direction with respect to the base  60  by being guided by concave groove portions  60   a  provided to extend in the left and right direction at both positions in front and rear of the base  60 . In addition, in this embodiment, between a hooking portion  41   c  provided at the midway position in the slider  41  in the left and right direction and a hooking portion  60   c  provided at the right end position in the base  60 , a coil spring  61  as an impelling unit is stretched and is impelled so that the slider  41  is positioned at the right end in a slide range in the left and right direction. 
     In the slider  41 , substantially at the center of the upper surface thereof, the engagement portion  42  formed to protrude upward is provided. As the selective blocking mechanism  40  is raised and the engagement portion  42  is engaged with the concave portion  16   h  of the carriage  16 , the slider  41  is driven by the carriage  16  and is reciprocated in the left and right direction with respect to the base  60  by being linked with the carriage  16 . 
     In the base  60 , the cam member  50  having a cam surface on one surface is embedded so as to oppose the slider  41  which reciprocates on the cam surface. On the other hand, on the lower surface of the slider  41 , the blocking member  43  (see  FIGS. 20 to 22 ) is rotatably supported. The blocking member  43  is configured to rotate along with the reciprocation of the slider  41  and squeeze the second discharge tube  37  or the first discharge tube  35  according to a change in the rotation posture. A tube squeezing structure of the blocking member  43  will be described later in detail. 
     In addition, in the maintenance device  23 , the separation and approach movement unit which raises or lowers the slider  41  by raising or lowering the base  60  in the selective blocking mechanism  40  is provided. In this embodiment, a gear train of a plurality of gears which are axially supported by the frame body  29  so as to be rotatable is configured to perform, as well as driving of the separation and approach movement unit, rotation driving of the lock lever  84 , elevation driving of the wiper  75 , and rotation driving of the tube pump  38  using the rotation power of the motor  26  as driving force. 
     That is, as illustrated in  FIG. 4  in which the maintenance device  23  from which the frame body  29  is detached is viewed from the forward left direction, the gear train is configured so that a pinion  26   a  rotating integrally with the motor  26  is engaged with a first transmission gear  81  and a pump transmission gear  88  so as to transmit rotation of the motor  26 . 
     The pump transmission gear  88  is engaged with a pump gear (not shown) connected to the driving shaft of the tube pump  38  and transmits the rotation power of the motor  26  to the pump gear, thereby driving the tube pump  38 . In addition, in this embodiment, the tube pump  38  performs a suction operation as the motor  26  rotates counterclockwise as viewed from the left (hereinafter, this is called “CCW rotation”) and does not perform the suction operation in the case where the motor  26  rotates clockwise (hereinafter, this is called “CW” rotation). 
     On the other hand, the first transmission gear  81  transmits the rotation of the motor  26  to a second transmission gear  82  and a third transmission gear  86  which are engaged with the first transmission gear  81 . In addition, the third transmission gear  86  is further engaged with a fourth transmission gear  87  which is an example of a rotation unit and transmits the rotation of the motor  26  to the fourth transmission gear  87 . By the configuration of the gear train, in this embodiment, when the motor  26  (the pinion  26   a ) undergoes the CCW rotation, the second transmission gear  82  undergoes the CCW rotation, and the fourth transmission gear  87  undergoes the CW rotation. 
     The second transmission gear  82  is pressed against a cam gear  90  positioned on the right which is a rear surface side by a spring  83  provided at a rotation shaft portion  82   j . The cam gear  90  generates a frictional force at the contact surface which comes in contact with the second transmission gear  82  by the pressing, and a frictional clutch mechanism is configured between the cam gear  90  and the second transmission gear  82  so as to rotate in synchronization with the second transmission gear  82  by the generated frictional force. 
     In this embodiment, the lock lever  84  is typically impelled by a lock spring  85  to undergo the CW rotation around a rotation shaft portion  84   j  and is in an inclined state in which the upper side thereof is slightly inclined forward. In addition, when the cam gear  90  is rotated, the lock lever  84  is rotated around the rotation shaft portion  84   j  according to a cam shape formed in the cam gear  90 , and undergoes the CCW rotation against the impelling force of the lock spring  85  and be in a substantially erected state. 
     In addition, when the cam gear  90  is rotated, the wiper  75  is raised and lowered according to a cam groove formed in the cam gear  90 . In this embodiment, the wiper  75  has a wiper blade  75   a  that wipes the liquid ejecting head  19  and a wiper holding member  76  that holds the wiper blade  75   a , and when the cam gear  90  (the second transmission gear  82 ) undergoes the CCW rotation, the wiper holding member  76  is raised. In addition, below the wiper holding member  76 , an absorbing member  78  is disposed which receives and absorbs ink in the liquid ejecting head  19  which falls down in the direction of gravity along the wiper  75  after being wiped by the wiper blade  75   a.    
     On the other hand, the fourth transmission gear  87  is configured to raise and lower the selective blocking mechanism  40  (the base  60 ). That is, as illustrated in  FIGS. 4 and 5 , the fourth transmission gear  87  rotates a clutch gear  122  provided in a clutch member  120  (here, the CW rotation) thereby moving a rack slider  65  as a slide member in which a rack  66  is formed in the forward direction. That is, the rack  66  is always engaged with the clutch gear  122 , and as the rack  66  is moved forward by the rotation of the clutch gear  122 , the rack slider  65  is slid forward. 
     On the forward side of the rack slider  65 , two inclined surface portions  67  which are inclined forward are provided. When the rack slider  65  is moved forward while two protruding portions  62  extending downward from the base  60  with predetermined width are caused to abut on the inclined surface portions  67 , the extending portions  62  are raised along the inclined surface portions  67 , and consequently the base  60  is also raised. Contrary to this, when the rack slider  65  is moved rearward, the extending portions  62  of the base  60  are lowered along the inclined surface portions  67 , so that the base  60  is also lowered. As described above, by the rack slider  65  in which the rack  66  engaged with the clutch gear  122  that rotates along with the fourth transmission gear  87  and the inclined surface portions  67  that come in sliding contact with the extending portions  62  of the base  60  are formed, a part of the separation and approach movement unit which causes the selective blocking mechanism  40  to be separated from or approach the carriage  16  by elevating the base  60  is configured. 
     In addition, in the separation and approach movement unit, the clutch member  120  is switched between two states including a state of transmitting the rotation of the fourth transmission gear  87  to the sliding movement of the rack slider  65  (this is called an “ON state”) and a state of not transmitting the rotation thereof to the sliding movement of the rack slider  65  (this is called an “OFF state”). In this embodiment, as illustrated in  FIG. 5 , by using a lever member  79  as a displacement member which rotates and is displaced around a rotation shaft portion  79   a  that is axially supported by the frame body  29  so as to be rotatable, the clutch member  120  is switched between the ON state and the OFF state. As such, including the clutch member  120  and the fourth transmission gear  87  as the rotation unit, the clutch mechanism  100  that switches the rotation transmission state between the fourth transmission gear  87  and the clutch member  120  and the lever member  79  as the displacement member constitute the power transmission switching device. 
     That is, as illustrated in  FIG. 6 , in the state where the cap holding member  71  is moved to the right as the carriage  16  is moved to the maintenance area MA, an upper end portion  79   c  which is one end side of the lever member  79  abuts on a lower surface portion  71   c  formed on the lower surface of the cap holding member  71 . The lever member  79  rotates around the rotation shaft portion  79   a  by this abutting operation and is displaced so that a lower end portion  79   b  which is the other end side thereof is moved to the left. By the displacement of the lever member  79 , switching of the rotation transmission state between the fourth transmission gear  87  and the clutch gear  122  in the clutch mechanism  100  is allowed. 
     In addition, as illustrated in  FIG. 6 , in the cap holding member  71 , a stopper  71   b  protruding forward from the left end thereof is formed. The stopper  71   b  restricts the rotation by being engaged with the cam gear  90  in the state where each support bar  72  in the cap holding member  71  is positioned on the lower side flat portion  29   b  of the corresponding penetration groove  28  of the frame body  29 . On the other hand, in the state where the cap holding member  71  is moved to the right as the carriage  16  is moved to the maintenance area MA, the stopper  71   b  is separated from the cam gear  90  and releases the rotation restriction, thereby entering a state where the elevating movement of the wiper  75  and the rotation of the lock lever  84  are allowed. 
     Next, the configurations of the cam shape of the cam gear  90  which rotatably drives the lock lever  84  and the cam groove of the cam gear  90  which raises or lowers the wiper  75  will be described with reference to  FIGS. 7A to 9C . Thereafter, the configuration for switching between the ON state and the OFF state in the clutch mechanism  100  will be described with reference to  FIGS. 10 to 15 . 
     As illustrated in  FIG. 7A , a part of the outer peripheral surface of the cam gear  90  is a convex portion  96  protruding outward in the diameter direction in a substantially trapezoidal shape. Both end portions of the outer peripheral surface of the convex portion  96  are inclined surfaces of which the distances from the shaft center of the cam gear  90  in the radial direction are gradually changed, and the tip end portion of the outer peripheral surface thereof is an arc surface. Therefore, in a procedure in which the cam gear  90  is rotated in one direction, when the inclined surface on a rotation starting end side of the convex portion  96  is engaged with a protrusion  84   b  on the lower end side of the lock lever  84 , an upper end portion  84   a  of the lock lever  84  is raised. In addition, as illustrated in  FIG. 8A , in a procedure in which the arc surface of the convex portion  96  is engaged with the protrusion  84   b , the upper end portion  84   a  is substantially erected and is maintained at a lock position at which the movement of the carriage  16  is restricted. When the cam gear  90  is continuously rotated and the inclined surface on a rotation ending end side of the convex portion  96  is engaged with the protrusion  84   b , the upper end portion  84   a  is lowered, and as illustrated in  FIG. 9A , returns to its original position (retreat position) illustrated in  FIG. 7A . In this manner, the convex portion  96  of the cam gear  90  is formed. 
     In addition, on the end surface of the cam gear  90  which is on the opposite side to the surface (clutch surface) abutting on the second transmission gear  82 , a cam groove  95  with which a guide pin  77  protruding from the wiper holding member  76  of the wiper  75  toward the cam gear  90  is engaged is formed. The cam groove  95  is formed on a predetermined path so that the distance from the shaft center of the cam gear  90  to the cam groove  95  in the radial direction is gradually increased as the cam gear  90  undergoes the CCW rotation. In addition, in a procedure in which the guide pin  77  runs from one end to the other end of the cam groove  95 , the amount of deviation from the shaft center of the cam gear  90  to the cam groove  95  in the radial direction is the same as the elevation stroke length of the wiper  75 . Therefore, as illustrated in  FIG. 9A , when the guide pin  77  is moved upward by being guided by the cam groove  95 , the wiper  75  is raised by the elevation stroke length from the retreat position and is disposed at a wiping position for wiping the liquid ejecting head  19 . Originally, when the cam gear  90  is reversed (here, the CW rotation), the guide pin  77  inserted into the cam groove  95  is moved downward by being guided by the cam groove  95 , and thus reaches its original position illustrated in  FIG. 7A . Accordingly, the wiper  75  is lowered by the elevation stroke length from the wiping position and is disposed at the retreat position. 
     In addition, as illustrated in  FIG. 7A , in the cam gear  90 , a locking concave portion  91  is formed at a position on the opposite side to the cam groove  95  with the shaft center interposed therebetween. The locking concave portion  91  constitutes a locked portion with which the stopper  71   b  protruding forward from the cap holding member  71  when the cap holding member  71  (the cap  27 ) is lowered and is at the retreat position where the cap  27  is separated from the liquid ejecting head  19  is engaged so as to stop the rotation of the cam gear  90 . 
     That is, as illustrated in  FIG. 7B , when the wiper  75  and the lock lever  84  are at the retreat position, the stopper  71   b  is inserted into the locking concave portion  91  of the cam gear  90 . Therefore, when the cap  27  is at the retreat position, by the locking operation of the stopper  71   b , the wiper  75  and the lock lever  84  are in a locked state of being locked at the retreat position. In this state, the rotation of the cam gear  90  is restricted by the locking operation of the stopper  71   b  against a rotating load that exceeds a predetermined load. Therefore, even when the power from the motor  26  is transmitted to the second transmission gear  82  so as to be rotated, slipping occurs in the frictional clutch between the cam gear  90  and the second transmission gear  82 , and the second transmission gear  82  enters an idling state. 
     In addition, as illustrated in  FIG. 8B , when the stopper  71   b  is disengaged from the locking concave portion  91  as the cap holding member  71  is raised, the cam gear  90  is in a state of being rotated (here, the CCW rotation), so that the wiper  75  can be raised from the retreat position to the wiping position. 
     In the cam gear  90 , a concave portion  94  is formed at a position opposing the stopper  71   b  returned to the left end position which is the locking position as the carriage  16  is moved to the left from the maintenance area MA and the cap holding member  71  is lowered in a state where the wiper  75  is at the wiping position illustrated by the double-dot-dashed line of  FIG. 9A . In a state in which the carriage  16  becomes distant from the maintenance area MA in order to move to the printing area PA from the maintenance area MA after terminating an ink suctioning operation, the cap  27  is lowered before the liquid ejecting head  19  is wiped by the wiper  75 , and the stopper  71   b  that moves to the left due to the lowering operation is inserted into the concave portion  94  of the cam gear  90  as illustrated in  FIG. 9B . 
     In addition, an inner wall surface in a movement direction in which the stopper  71   b  inserted into the concave portion  94  moves relative to the cam gear  90  when the cam gear  90  tries to be reversed and undergo the CW rotation in the state where the stopper  71   b  is inserted into the concave portion  94  is formed as an inclined surface  93 . The inclined surface  93  is an inclined surface of which the depth is gradually reduced from the same depth as that of the bottom surface of the concave portion  94  toward the relative movement direction of the stopper  71   b  during the CW rotation of the cam gear  90 . Therefore, when the motor  26  undergoes the CW rotation in the state illustrated in  FIG. 9B , the stopper  71   b  rides on the inclined surface  93  and can escape from the concave portion  94  as illustrated in  FIG. 9C , and thus the CW rotation, that is, reversal of the cam gear  90  is allowed. As such, the inclined surface  93  is a movement allowing surface which allows the movement of the stopper  71   b  on the path on which the stopper  71   b  reaches the locking concave portion  91  from the concave portion  94  so as to allow the reversal of the cam gear  90  for moving the wiper  75  from the wiping position to the retreat position. 
     Moreover, on the outer peripheral surface of the cam gear  90 , tooth portions  90   a  are formed substantially on the opposite side to the concave portion  96  at positions reaching a predetermined angle range (in this example, about 90 degrees). The tooth portions  90   a  are formed in a predetermined section on the outer peripheral surface of the cam gear  90  so as to be directly engaged with the first transmission gear  81  when the wiper  75  which is elevated as the guide pin  77  is guided by the cam groove  95  during the rotation of the cam gear  90  is in a midway area of the elevation stroke excluding the retreat position and the wiping position. That is, the tooth portions  90   a  are formed in the predetermined section on the outer peripheral surface of the cam gear  90  so as to be directly engaged with the first transmission gear  81  when the cam gear  90  is in a midway area of a limited rotation range. 
     Therefore, when the first transmission gear  81  is rotated, since power is directly transmitted to the tooth portions  90   a  from the first transmission gear  81  when the wiper  75  is at the midway area of the elevation stroke, the cam gear  90  is reliably rotated. In addition, a part where the tooth portions  90   a  are not formed on the outer peripheral surface of the cam gear  90  has an arc surface that cannot be engaged with the first transmission gear  81 , and thus when the cam gear  90  is at rotation positions at which the guide pin  77  is disposed in the vicinities of both ends of the cam groove  95 , the cam gear  90  cannot be engaged with the first transmission gear  81 . Therefore, when the first transmission gear  81  is not engaged with the tooth portions  90   a , rotation is transmitted to the cam gear  90  only through the frictional engagement with the second transmission gear  82 . 
     In addition, when the guide pin  77  abuts on one end surface  95   a  of the cam groove  95 , slipping occurs in the frictional clutch and the second transmission gear  82  idles, so that further rotation (CW rotation) of the cam gear  90  is restricted. In addition, even when the guide pin  77  abuts on the other end surface  95   b  of the cam groove  95 , similarly, slipping occurs in the frictional clutch and the second transmission gear  82  idles, so that further rotation (CCW rotation) of the cam gear  90  is restricted. As such, the frictional clutch mechanism is configured so that even when the second transmission gear  82  is continuously rotated in a certain direction, the cam gear  90  is reciprocated only in the predetermined angle range. 
     Consequently, as illustrated in  FIG. 7A , in a range at the midway of the rotation range of the cam gear  90  which is reciprocated only in the predetermined angle range, the central angle of the formation position and the formation range of the convex portion  96  with respect to the cam gear (in this example, about 30 degrees) is set so that the concave portion  96  is engaged with the protrusion  84   b  of the lock lever  84 . Therefore, after the cam gear  90  undergoes the CCW rotation by a predetermined rotation amount from the initial position illustrated in  FIG. 7B , the concave portion  96  starts to be engaged with the protrusion  84   b . As a result, as illustrated in  FIGS. 7A to 9C , in the maintenance device  23 , first, the wiper  75  starts to be raised, and the lock lever  84  starts to be raised during the raising operation and reaches the locked position. From this, after the cam gear  90  is further rotated by about 30 degrees, the lock lever  84  is lowered from the locked position and is returned to the retreat position, and thereafter the wiper  75  is operated to reach the wiping position. 
     Next, the configuration of a mechanism for switching between the ON state and the OFF state in the clutch mechanism  100  will be described. As illustrated in  FIG. 10 , the clutch mechanism  100  of this embodiment is configured of a clutch shaft  101 , a locking portion  102 , an engagement member  110 , a washer  118 , a first coil spring  119  as a first direction impelling member, the clutch member  120 , a second coil spring  124  as a second direction impelling member, a washer  125 , and the fourth transmission gear  87 . In addition, the first direction impelling member and the second direction impelling member exhibit impelling directions in a certain state and are not members that are impelled always in a constant direction. 
     The clutch shaft  101  functions as a rotation shaft and shaft portions which are axially supported by the frame body  29  to be rotatable are formed at shaft end portions  101   a  and  101   b  on both sides thereof. At the shaft end portion  101   a  on one side, the locking portion  102  having two protruding portions  103  which protrude in a direction intersecting the axial direction by predetermined amounts at positions having an opposite angle with the clutch shaft  101  as the center is provided to rotate integrally with the clutch shaft  101 . In addition, in this embodiment, the locking portion  102  is formed integrally with the clutch shaft  101 . Originally, the locking portion  102  may be formed as a different body from the clutch shaft  101  and be fixed to the clutch shaft  101  to rotate integrally with the clutch shaft  101 . 
     From the shaft end portion  101   b  side which is the first direction side in the clutch shaft  101 , the engagement member  110  is inserted so that the clutch shaft  101  penetrates therethrough. The engagement member  110  has a disk portion  111  formed in an awning shape on the shaft end portion  101   a  side which is the second direction side at the peripheral edge, and a cylindrical portion  112  with a smaller diameter than that of the disk portion  111 . In the cylindrical portion  112 , a first engagement portion  113  and a second engagement portion  114  which abut on and are engaged with the protruding portions  103  in the axial direction are formed. The first and second engagement portions  113  and  114  have groove shapes that dig out the cylindrical portion  112  from the end surface on the second direction side which is opposite to the first direction, in the first direction along the axial direction of the clutch shaft  101 . In addition, in this embodiment, the first engagement portion  113  is formed in a groove shape that is deeper than that of the second engagement portion  114 . That is, a groove bottom surface  113 B of the first engagement portion  113  and a groove bottom surface  114 B of the second engagement portion  114  are formed so that they are at positions separated from each other in the axial direction of the clutch shaft  101 , specifically, the groove bottom surface  113 B of the first engagement portion  113  is positioned further toward the first direction side than the groove bottom surface  114 B of the second engagement portion  114 . In addition, the widths of the groove shapes, that is, the dimensions in the rotation direction are slightly greater than those of the protruding portions  103 , such that the protruding portion  103  moves to the first engagement portion  113  or the second engagement portion  114  in the axial direction and thus abuts on and is engaged with the groove bottom surface  113 B or the groove bottom surface  114 B. 
     In addition, between the groove of the first engagement portion  113  and the groove of the second engagement portion  114 , a wall portion  115  having a predetermined height from the end surface in the axial direction of the groove portion of the second engagement portion  114  (the groove bottom surface  114 B) in the second direction is formed. The wall portion  115  is provided so as to suppress the protruding portion  103  from rotating and moving between the first and second engagement portions  113  and  114 . That is, in the case where the protruding portion  103  rotates along with the clutch shaft  101 , during the rotation of the clutch shaft  101  in the state where the protruding portion  103  is engaged with the second engagement portion  114 , the wall portion  115  is formed to have a height that maintains the engaged state in the rotation direction. 
     Subsequently, the clutch shaft  101  penetrates through the washer  118  and the first coil spring  119 . Due to the washer  118 , relative rotation between the first coil spring  119  and the engagement portion  110  can be smoothly performed. 
     Next, the clutch shaft  101  penetrates through the clutch member  120 . The clutch member  120  has a clutch body  121  which is a shaft portion in a substantially cylindrical shape, and the clutch gear  122  is formed on the outer peripheral surface of the end portion of the clutch body  121  on the first coil spring  119  side. In addition, in the clutch body  121  on the opposite side to the clutch gear  122  in the axial direction, a plurality of (here, three) driven-side protruding portions  123  which protrude from the base end portion of the clutch body  121  along the axial direction of the clutch shaft  101  in the first direction on the opposite side to the first coil spring  119  are formed at predetermined intervals. 
     Subsequently, the clutch shaft  101  penetrates through the second coil spring  124  and the washer  125 . Due to the washer  125 , relative rotation between the second coil spring  124  and the fourth transmission gear  87  can be smoothly performed. In addition, the spring force of the second coil spring  124  is smaller than the spring force of the first coil spring  119 . 
     Last, the fourth transmission gear  87  as the rotation unit is mounted to the shaft end portion  101   b  side of the clutch shaft  101  so as to rotate integrally with the clutch shaft  101 . The fourth transmission gear  87  has a cylindrical shape portion  127  on the side opposing the clutch member  120 . In addition, in the outer periphery of the cylindrical shape portion  127 , a plurality of (here, three) driving-side protruding portions  126  which protrude from the base end portion of the cylindrical shape portion  127  along the axial direction of the clutch shaft  101  so as to correspond to the respective driven-side protruding portions  123  of the clutch body  121  are formed at predetermined intervals in the outer peripheral direction. 
     The clutch mechanism  100  is configured as such. Therefore, the engagement member  110 , the washer  118 , the first coil spring  119 , and the clutch member  120  can be rotated concentrically around the clutch shaft  101  and be moved along the axial direction of the clutch shaft  101 . On the other hand, the fourth transmission gear  87  and the clutch shaft  101  are not moved in the axial direction. In addition, the spring force of the second coil spring  124  compressed during the movement is set so that the compression force of the compressed second coil spring  124  is always smaller than the compression force of the first coil spring  119 . In addition, the engagement member  110  and the clutch member  120  can be rotated relative to the clutch shaft  101 . 
     However, the maintenance device  23  including the clutch mechanism  100  having such a configuration is configured so that whether or not the rotation of the fourth transmission gear  87  is transmitted to the rotation of the clutch gear  122 , that is, whether the ON state or the OFF state is switched to, accords with whether the protruding portion  103  is engaged with the first engagement portion  113  or the second engagement portion  114 . Regarding this switching mechanism, the configuration of a mechanism for switching will be described with reference to  FIGS. 11 to 15 . In addition, for the convenience of description, the clutch mechanism  100  that is initially in the OFF state is described. 
     As illustrated in  FIG. 11 , in the state where the carriage  16  is moved to, for example, the printing area PA and does not abut on the cap holding member  71 , each support bar  72  is positioned on the lower side flat portion  29   b  in the penetration groove  28 . In this state, the lower surface portion  71   c  of the cap holding member  71  is separated from the upper end portion  79   c  of the lever member  79 . Therefore, the lower end portion  79   b  of the lever member  79  is in a state of not exerting an external force on the disk portion  111  of the engagement member  110 . Accordingly, the clutch member  120  is impelled toward the right by the second coil spring  124  with respect to the fourth transmission gear  87 . In addition, the engagement member  110  is impelled toward the right by the first coil spring  119  with respect to the clutch member  120 . Here, the protruding portion  103  of the clutch shaft  101  is engaged with the first engagement portion  113  in the cylindrical portion  112  of the engagement member  110 . Therefore, the engagement member  110  is at a position that approaches the farthest position on the right with respect to the clutch shaft  101 . As a result, the driven-side protruding portion  123  formed in the clutch member  120  is in a state of being separated from the driving-side protruding portion  126  formed in the fourth transmission gear  87  in the axial direction so as not to be engaged, that is, in the OFF state. In addition, here, the first coil spring  119  is in a state of not substantially being compressed, that is, has a substantially free length. In addition, the second coil spring  124  is in a slightly compressed state or has a substantially free length. 
     Next, as illustrated in  FIG. 12 , when the carriage  16  is moved to the maintenance area MA, each support bar  72  of the cap holding member  71  is positioned on the upper side flat portion  29   d  in the penetration groove  28 . Here, in this embodiment, each support bar  72  is moved to the left end position (this is called a “first maintenance position MP 1 ”) in the upper side flat portion  29   d , and the lower surface portion  71   c  of the cap holding member  71  is in a state of nearly abutting on the upper end portion  79   c  of the lever member  79 . Thereafter, as each support bar  72  is moved to a position separated by a distance SK to the right along the upper side flat portion  29   d  (this is called a “maintenance position MP 2 ”), the upper end portion  79   c  of the lever member  79  is moved to the right. Therefore, by the movement of the distance SK of the cap holding member  71 , the lever member  79  rotates and is displaced around the rotation shaft portion  79   c , and the lower end portion  79   b  of the lever member  79  abuts on and presses the disk portion  111  of the engagement member  110  in the left direction. In addition, the engagement member  110  is in a state of being moved to the left against the impelling forces of the first and second coil springs  119  and  124 . 
     Due to the movement of the engagement member  110  to the left, the first and second coil springs  119  and  124  are compressed. Here, since the compression force of the second coil spring  124  is smaller than that of the first coil spring  119 , due to the movement of the engagement member  110  to the left, the compression amount of the second coil spring  124  becomes greater than that of the first coil spring  119 . As the second coil spring  124  is compressed, the clutch member  120  is moved to the left. When the clutch member  120  is moved to a position hitting against the fourth transmission gear  87 , the first coil spring  119  is compressed. In this state, since the compression force of the first coil spring  119  is greater than that of the second coil spring  124 , the clutch member  120  is impelled toward the left. In  FIG. 12 , the tip ends of the driven-side protruding portion  123  of the clutch member  120  and the driving-side protruding portion  126  of the fourth transmission gear  87  abut on each other (similarly in  FIG. 13 ). From this state, when the fourth transmission gear  87  is rotated, the driven-side protruding portion  123  and the driving-side protruding portion  126  deviate from each other in the rotation direction. In addition, since the clutch member  120  is impelled toward the left, the clutch member  120  is moved to the left. In addition, as in  FIG. 14 , a predetermined amount of the driven-side protruding portion  123  is engaged with the driving-side protruding portion  126  in the left and right direction. By this engagement in the left and right direction, the rotation of the fourth transmission gear  87  is transmitted to the clutch member  120 , thereby rotating the clutch gear  122  of the clutch member  120 . Therefore, the fourth transmission gear  87  functions as the rotation unit, and the clutch member  120  functions as a rotation transmission unit. 
     However, in the state where the engagement member  110  is moved to the left, as illustrated in  FIG. 13 , the wall portion  115  of the engagement member  110  is positioned further toward the left than the protruding portion  103 . That is, the protruding portion  103  enters a state of being moved between the first engagement portion  113  and the second engagement portion  114  by the rotation of the clutch shaft  101 . Therefore, in this embodiment, the left direction along the axial direction is the first direction and the right direction is the second direction. In this state, as the fourth transmission gear  87  is rotated by the motor  26  (here, the CW rotation), the protruding portion  103  is rotated relative to the engagement member  110  by a predetermined angle via the clutch shaft  101  and the locking portion  102 . As a result, as illustrated in  FIG. 14 , the protruding portion  103  is rotated from a position separated from the first engagement portion  113 , passes through the right side of the wall portion  115 , and is moved to a position facing the second engagement portion  114  in the left and right direction (the axial direction of the clutch shaft  101 ). 
     However, when the clutch member  120  is moved to the left, as illustrated in  FIGS. 12 and 13 , according to the rotation state of the fourth transmission gear  87 , there may be cases where the driven-side protruding portion  123  abuts on the driving-side protruding portion  126  in the axial direction, that is, in the left and right direction (that is, the end surfaces thereof come in contact with each other). In such a case, the first coil spring  119  is compressed in the clutch mechanism  100 , and the movement of the engagement member  110  which is moved to the left according to the displacement (rotation) of the lever member  79  is not restricted. In addition, in this embodiment, after the fourth transmission gear  87  is rotated so as to release the state where the driven-side protruding portion  123  and the driving-side protruding portion  126  abut on each other, switching from the OFF state to the ON state is performed. 
     In addition, in this embodiment, the fourth transmission gear  87  is initially rotated by a predetermined amount in a direction so as not to move the rack slider  65  in the forward direction (here, the CCW rotation). The clutch member  120  is in a state of always having a predetermined rotating load since the clutch gear  122  is always engaged with the rack  66  of the rack slider  65 . Regarding this, in this embodiment, the frictional resistance that is generated when the abutting surfaces of the driving-side protruding portion  126  of the fourth transmission gear  87  and the driven-side protruding portion  123  of the clutch member  120  move relative to each other, that is, the rotating load is smaller than the rotating load of the clutch member  120 . 
     However, in this embodiment, although not shown in the figure, in the state where the abutting state of the driving-side protruding portion  126  and the driven-side protruding portion  123  is released, a gap is formed between the driving-side protruding portion  126  and the driven-side protruding portion  123  in the CW rotation direction. Therefore, as illustrated in  FIG. 14 , thereafter, the fourth transmission gear  87  undergoes the CW rotation by a predetermined angle and rotates the protruding portion  103  in a direction in which the driving-side protruding portion  126  and the driven-side protruding portion  123  do not abut on each other, thereby moving the protruding portion  103  from the first engagement portion  113  to a position that faces the second engagement portion  114  in the left and right direction. As a result, since the clutch member  120  does not undergo the CW rotation during the rotating movement of the protruding portion  103 , the rack slider  65  is not moved forward. 
     Thereafter, as illustrated in  FIG. 15 , when the carriage  16  is moved to the printing area PA from the second maintenance position MP 2 , the abutting state of the upper end portion  79   c  of the lever member  79  on the lower surface portion  71   c  of the cap holding member  71  is released. Then, the lower end portion  79   b  of the lever member  79  is moved to the right. Consequently, the engagement member  110  is moved to the right by the impelling force of the first coil spring  119 . Here, since the protruding portion  103  faces the second engagement portion  114  in the left and right direction, the protruding portion  103  abuts on and is engaged with the groove bottom surface  114 B of the second engagement portion  114  on the left. Since the groove bottom surface  114 B of the second engagement portion  114  is positioned further toward the second direction side than the groove bottom surface  113 B of the first engagement portion  113 , the position of the engagement member  110  in  FIG. 15  is positioned further toward the first direction side than the position of the engagement member  110  in  FIG. 11 . Here, the distance between the engagement member  110  and the clutch member  120  is increased, and thus the first coil spring  119  is in an elongated state, while the second coil spring  124  is compressed. Therefore, the clutch member  120  maintains the state of being impelled toward the left, and the engagement between the driving-side protruding portion  126  of the fourth transmission gear  87  and the driven-side protruding portion  123  of the clutch body  121  in the left and right direction is maintained. As a result, the clutch mechanism  100  can transmit the rotation of the fourth transmission gear  87  to the clutch body  121  as the driving-side protruding portion  126  is engaged with the driven-side protruding portion  123  in the left and right direction so as to abut on each other during rotation. In this manner, the clutch mechanism  100  is set to the ON state of rotating the clutch gear  122  of the clutch body  121  by the fourth transmission gear  87 . 
     On the other hand, in the case where the clutch mechanism  100  is switched to the OFF state from the ON state, as apparent from the above description, the relative rotation direction of the protruding portion  103  to the engagement member  110  may be the reverse direction to the rotation direction of the case of the switching from the OFF state to the ON state. That is, in this embodiment, as illustrated in  FIG. 12 , the carriage  16  is moved to the second maintenance position MP 2  and releases the state of the engagement between the protruding portion  103  and the second engagement portion of the engagement member  110 . In addition, by rotating the fourth transmission gear  87  by a predetermined angle (here, the CCW rotation), the protruding portion  103  is moved from the second engagement portion  114  of the engagement member  110  to a position facing the first engagement portion  113 . Thereafter, when the carriage  16  is moved from the second maintenance position MP 2  to the first maintenance position MP 1  or further toward the left, the engagement member  110  and the clutch member  120  are moved to the right by the impelling force of the second coil spring  124 , and by this movement, the protruding portion  103  is engaged with the groove portion of the first engagement portion  113 . Here, the second coil spring  124  is in an elongated state as illustrated in  FIG. 11 , and the driven-side protruding portion  123  of the clutch member  120  enters a state of becoming distant from the driving-side protruding portion  126  of the fourth transmission gear  87 , so as to enter the OFF state. 
     In addition, even in the case where the clutch mechanism  100  is switched from the ON state to the OFF state, the rack slider  65  is not moved. Specifically, without the state where the driven-side protruding portion  123  abuts on the driving-side protruding portion  126  in the axial direction, that is, the left and right direction, the driven-side protruding portion  123  and the driven-side protruding portion  126  enter a state of abutting on each other in the rotation direction. Therefore, for example, in a case where switching from the ON state to the OFF state is performed in the state where the clutch member  120  is subjected to the CCW rotation and the rack slider  65  is moved rearward, even though the fourth transmission gear  87  undergoes the CCW rotation by a predetermined angle, the rack slider  65  completes the rearward movement and thus does not move further. In addition, in a case where switching from the ON state to the OFF state in the state where clutch member  120  is subjected to the CW rotation and the rack slider  65  is moved forward, even though the fourth transmission gear  87  is subjected to the CCW rotation by a predetermined angle, the driving-side protruding portion  126  is set so as not to abut on the driven-side protruding portion  123 . That is, between the driving-side protruding portion  126  and the driven-side protruding portion  123 , each protruding portion is formed to have a gap corresponding to the predetermined angle of the fourth transmission gear  87 . 
     In the maintenance device  23  of this embodiment, as the carriage  16  is moved to the maintenance position as such, the operation state of the clutch mechanism  100  can be set to any of the ON state and the OFF state. In addition, by the clutch mechanism  100  which enters the ON state set by the carriage  16  moving to the second maintenance position MP 2 , a part of the separation and approach movement unit which causes the selective blocking mechanism  40  to approach or be separated from the carriage  16  is configured. 
     In addition, in this embodiment, an elevation mechanism that causes the selective blocking mechanism  40  to approach and be separated from the carriage  16  respectively by raising and lowering is configured as a part of the separation and approach movement unit. In addition, the selective blocking mechanism  40  includes a selection mechanism which selects a tube to be squeezed as the slider  41  in which the engagement portion  42  is in a state of being engaged with the carriage  16  by being raised is moved by the movement of the carriage  16 . The elevation mechanism of the selective blocking mechanism  40  and the selection mechanism in the selective blocking mechanism  40  will be sequentially described. 
     As illustrated in  FIG. 16 , the elevation mechanism is configured to include the extending portion  62  provided in the base  60  of the selective blocking mechanism  40 , the rack slider  65 , the clutch member  120  set to the ON state, and the fourth transmission gear  87 . In the rack slider  65 , the rack  66  formed on the lower surface of a flat plate portion  65   a  on the rear end side thereof is always engaged with the clutch gear  122  formed in the clutch member  120 . In addition, as described above, the front end side of the rack slider  65  is provided with the inclined surface portion  67  which is engaged with the extending portion  62  to raise the rack slider  65  along with the forward movement. In addition, here, the selective blocking mechanism  40  is in the lowered state. 
     However, as illustrated in  FIG. 17A , when the carriage  16  is moved in the left and right direction and the engagement portion  42  of the slider  41  is positioned inside the concave portion  16   h  provided in the carriage  16  in the upward and downward direction, the movement of the carriage  16  is stopped, and the engagement portion  42  is raised from the lowered state. That is, the rotation of the motor  26  is transmitted via the first and third transmission gears  81  and  86  to cause the fourth transmission gear  87  to undergo the CW rotation, such that the clutch gear  122  in the ON state also undergoes the CW rotation. Then, as illustrated in  FIG. 17B , the rack slider  65  moves forward and raises the extending portion  62  of the base  60 , such that the selective blocking mechanism  40  is raised along with the base  60 , and the engagement portion  42  of the slider  41  enters the concave portion  16   h  of the carriage  16 . As a result, the slider  41  enters an engagement established state of moving while being linked with the movement of the carriage  16  in the left and right direction. 
     Originally, as illustrated in  FIG. 17B , as the clutch gear  122  is reversed (that is, the CCW rotation) from the state where the rack slider  65  is moved forward as described above and raises the selective blocking mechanism  40 , the rack slider  65  is moved rearward and lowers the selective blocking mechanism  40 . By lowering the selective blocking mechanism  40 , the engagement portion  42  exits the concave portion  16   h , and the slider  41  enters an engagement released state of not moving by being linked with the carriage  16 . 
     Moreover, in this embodiment, the movement range of the rack slider  65  in the forward and rearward direction is restricted as the rack slider  65  abuts on the frame body  29 . In this restricted movement range, as described above, the rack  66  of the rack slider  65  and the clutch gear  122  are always in an engaged state. Therefore, when the clutch gear  122  undergoes the CCW rotation in the state illustrated in  FIG. 17A , or when the clutch gear  122  undergoes the CW rotation in the state illustrated in  FIG. 17B , engagement between the rack  66  and the clutch gear  122  is maintained in any case. That is, they are configured so that at least one gear is impelled in a direction to be engaged with the other gear, and when any one is rotated, the engagement is deviated, while they are in the engaged state by the impelling when rotation is stopped. 
     In this embodiment, as illustrated in  FIG. 18A , the rack  66  has four rack teeth  66   a ,  66   b ,  66   b , and  66   c . In addition, the rack tooth  66   a  at the forward end and the rack tooth  66   c  on the rearward end are respectively formed at the beam tip ends of a cantilever beam portion  66   af  and a cantilever beam portion  66   cf  each of which is provided with voids on the peripheral three sides in the flat plate portion  65   a  of the rack slider  65 . Therefore, the rack teeth  66   a  and  66   c  can be deflected and deformed in the upward and downward direction. In addition, the rack teeth  66   b  are formed integrally with the rack slider  65 . 
     Therefore, as illustrated in  FIG. 18B , when the clutch gear  122  undergoes the CCW rotation in the state where the selective blocking mechanism  40  is lowered, the cantilever beam portion  66   af  is deformed upward and deflected as shown by the double-dot-dashed line in the figure, and thus the engagement of the rack tooth  66   a  with the clutch gear  122  is deviated. In addition, when the rotation of the clutch gear  122  is stopped, the clutch gear  122  is impelled by the elasticity of the cantilever beam portion  66   af , and the deformation shown by the double-dot-dashed line in the figure returns to the original state, so that the rack tooth  66   a  is engaged with the clutch gear  122 . In addition, although not described, the rack tooth  66   c  operates in the same manner. 
     Subsequently, in the selective blocking mechanism  40  which squeezes a tube selected as the slider  41  is moved by being linked with the carriage  16 , the selection mechanism of the tube to be squeezed will be described with reference to  FIGS. 19 to 22 . 
     As illustrated in  FIG. 19 , the selective blocking mechanism  40  raised by the elevation mechanism causes the slider  41  to be pulled in the right direction by the coil spring  61  as described above. Therefore, the engagement portion  42  of the slider  41  is raised to be engaged with the carriage  16  at a determined position in the left and right direction. In addition, the slider  41  which is raised and engaged with the carriage  16  (the concave portion  16   h ) moves on the cam surface of the cam member  50  embedded in the base  60  having a substantially rectangular parallelepiped shape. In this embodiment, by the movement of the slider  41 , the second tube  37  or the first discharge tube  35  is selected to be squeezed. 
     That is, as illustrated in  FIG. 20 , the selective blocking mechanism  40  has the base  60  in which the cam member  50  is embedded and the slider  41 . In addition, the blocking member  43  which is axially supported so as to be rotatable on the lower surface of the slider  41  opposing the cam surface is guided to a selection position which is a specific position on the cam surface. Hereinafter, including this selection position, a configuration of guiding the blocking member  43  to selection positions in the selective blocking mechanism  40  will be described. 
     The slider  41  has a substantially rectangular shape in the plan view from above and has a columnar concave portion  45  formed substantially at the center position on the lower surface thereof. A state of the concave portion  45  fitted with the blocking member  43  including an arm portion with a rectangular plate shape extending straight from an annular portion fitted to the concave portion  45  to the left direction which is one of the diameter directions is maintained as the annular portion is impelled upward by a pressing member  46 , such that the blocking member  43  is axially supported so as to be oscillated. In addition, on the lower surface in the vicinity of the tip end portion of the arm portion in the blocking member  43 , a columnar pin portion  43  protruding downward is formed. 
     At the end portions of the slider  41  in the forward and rearward direction, side walls are formed in the upward and downward direction, and guide piece portions  41   a  protruding inward from the side walls in plate shapes are formed at four corners on the lower surface side. On the other hand, the base  60  is a case member having a substantially rectangular parallelepiped shape, and at both side walls in front and rear thereof, the concave groove portions  60   a  extend in the left and right direction. The guide piece portions  41   a  of the slider  41  are inserted into the concave groove portions  60   a  from the left, such that the slider  41  can slide in the left and right direction. In addition, the concave groove portion  60   a  is provided with an ending end portion  60   b  in the right direction, so that as the ending end portion  60   b  abuts on the guide piece portion  61   a  on the right of the slider  41 , the position of the slider  41  is determined in the left and right direction and the movement thereof to the right is restricted. 
     The base  60  is configured to include the cam member  50  having a substantially rectangular parallelepiped shape therein and support the intermediate portions of the second discharge tube  37  and the first discharge tube  35  to be lined up in the forward and rearward direction between the base  60  and the cam member  50  (see  FIG. 16 ). The cam member  50  includes a first pressing member  57 B and a second pressing member  57 B as pressing members capable of respectively pressing a part of the first discharge tube  35  and a part of the second discharge tube  37  from above (see  FIG. 22 ). 
     On the surface of the cam member  50 , over the front end portion from the rear end portion, a first wall  51 , a second wall  52 , a third wall  53 , and a fourth wall  54  are erected with a predetermined height from a base surface  50   a  on the lower side. In addition, on the left of the first to fourth walls  51  to  54 , a fifth wall  55  and a sixth wall  56  with island shapes are erected with a predetermined height from the same base surface  50   a . In addition, the cam member  50  is embedded in the base  60  so that the area where the walls are formed is positioned over the left end from substantially the center portion in the left and right direction in the base  60 . 
     However, due to these walls  51  to  56 , a so-called cam surface having a long groove portion mainly in the left and right direction is formed on the upper surface of the cam member  50 . The groove portion is widely open to the left end side and is parallel at equal intervals in the forward and rearward direction on the right end side, and as three selection passages having substantially rectangular shapes in the plan view in the left and right direction, guide grooves SL 1 , SL 2 , and SL 3  are formed. Regarding the guide grooves SL 1  to SL 3 , the guide grooves SL 1 , SL 2 , and SL 3  are disposed in this order from the rear side, and the widths of the guide grooves SL 1  to SL 3  in the forward and rearward direction are set to be slightly greater than the outside diameter of the pin portion  43   a  of the blocking member  43 . In addition, the first and second pressing members  57 B and  57 C are respectively disposed in the guide grooves SL 1  and SL 2  so as to be movable in the upward and downward direction. The blocking member  43  is moved in the left and right direction as the slider  41  is moved by being linked with the reciprocation of the carriage  16 , and the pin portion  43   a  is guided to the groove portion formed as described above and is thus guided to a predetermined position in the cam surface. 
     That is, as illustrated in  FIGS. 20 and 21 , on the path of the fourth wall  54  in the extension direction, at a position on the right end side from the midway position of a rear side surface  54   a  extending straight in the left and right direction with a slight difference, an inclined surface  54   b  which is inclined obliquely rearward to the right is formed. On the other hand, the front end side of the third wall  53  that forms the guide groove SL 3  with the fourth wall  54  extends straight in the left and right direction. In addition, the first wall  51  that forms the guide groove SL 1  with the second wall  52  is formed so that a front side surface  51   a  has a substantially triangular contour shape in which the forward side thereof is convex in the plan view and thus the gap between the first wall  51  and the fourth wall  54  is narrowed in the forward and rearward direction at a position further toward the left end side than the fifth and sixth walls  55  and  56 . 
     By this configuration, when the slider  41  is moved from the left to the right and inserted so as to be assembled with the base  60 , the pin portion  43   a  of the blocking member  43  is moved to the forward side along the left portion from the protruding end of the substantially triangular contour portion in the front side surface  51   a  of the first wall  51  and then passes through the gap between the protruding end and the rear side surface  54   a  of the fourth wall  54 . In addition, as shown by the solid line arrow in the figure, when the slider  41  is moved to a position where movement to the right is restricted as the pin portion  43   a  abuts on the inclined surface  54   b  and slides, the pin portion  43   a  is guided to a specific position in the guide groove SL 3 . In this embodiment, this position is called an initial position. In addition, this initial position is one of the selection positions, and the blocking member  43  with the initial value is in a state illustrated by the solid line denoted by reference numeral  43 A. 
     Next, when the slider  41  is moved to the left from the state where the pin portion  43   a  is at the initial position, as shown by the broken line arrow in the figure, the pin portion  43   a  abuts on an inclined surface  56   a  which is inclined rearward to the left in the sixth wall  56 , slides on the inclined surface  56   a , and comes into contact with a rear side surface  56   b  extending straight in the left and right direction of the sixth wall  56 . Thereafter, in a case where the slider  41  is continuously moved to the left, the pin portion  43   a  is moved further to the left along the rear side surface  56   b , abuts on a right portion from the protruding end of the substantially triangular contour portion in the front side surface  51   a  of the first wall  51 , and then passes through the gap between the protruding end and the rear side surface  54   a  of the fourth wall  54  to the left. As a result, the pin portion  43   a  is moved again to the position when the slider  41  is inserted into the base  60 . 
     On the other hand, in a case where the slider  41  is reversed and moved to the right in the state where the pin portion  43   a  is positioned to come into contact with the rear side surface  56   b  of the sixth wall  56 , as shown by the solid line arrow in the figure, the pin portion  43   a  abuts on an inclined surface  53   b  inclined rearward to the right in the third wall  53  and slides to the right. In addition, when the slider  41  is moved to a position where movement to the right is restricted, the pin portion  43   a  is guided to a specific position in the guide groove SL 2 . In this embodiment, this position is called a second blocking position. In addition, the second blocking position is one of the selection positions, and the blocking member  43  at the second blocking position is in a state illustrated by the double-dot-dashed line denoted by reference numeral  43 C. 
     Next, when the slider  41  is moved to the left from the state where the pin portion  43   a  is at the second blocking position, as shown by the broken line arrow in the figure, the pin portion  43   a  abuts on an inclined surface  55   a  which is inclined rearward to the left in the fifth wall  55 , slides on the inclined surface  55   a , and comes into contact with a rear side surface  55   b  extending straight in the left and right direction of the fifth wall  55 . Thereafter, in a case where the slider  41  is continuously moved to the left, the pin portion  43   a  is moved further to the left along the rear side surface  55   b , abuts on a right portion from the protruding end of the substantially triangular contour portion in the front side surface  51   a  of the first wall  51 , and then passes through the gap between the protruding end and the rear side surface  54   a  of the fourth wall  54  to the left. As a result, the pin portion  43   a  can be moved to a position where the pin portion  43   a  can be moved to the second blocking position or the position when the slider  41  is inserted into the base  60 . 
     On the other hand, in a case where the slider  41  is reversed and moved to the right in the state where the pin portion  43   a  is positioned to come into contact with the rear side surface  55   b  of the fifth wall  55 , as shown by the solid line arrow in the figure, the pin portion  43   a  abuts on an inclined surface  52   b  inclined rearward to the right in the second wall  52  and slides to the right. In addition, when the slider  41  is moved to a position where movement to the right is restricted, the pin portion  43   a  is guided to a specific position in the guide groove SL 1 . In this embodiment, this position is called a first blocking position. In addition, the first blocking position is one of the selection positions, and the blocking member  43  at the first blocking position is in a state illustrated by the double-dot-dashed line denoted by reference numeral  43 B. 
     Next, when the slider  41  is moved to the left from the state where the pin portion  43   a  is at the first blocking position, as shown by the broken line arrow in the figure, the pin portion  43   a  abuts on the front side surface  51   a  in the first wall  51  and slides on the front side surface  51   a  to the right. That is, the pin portion  43   a  abuts on a right portion from the protruding end of the substantially triangular contour portion in the front side surface  51   a  of the first wall  51 , and then passes through the gap between the protruding end and the rear side surface  54   a  of the fourth wall  54  to the left. As a result, the pin portion  43   a  can be moved again to the position where the pin portion  43   a  can be moved to the second blocking position or the position when the slider  41  is inserted into the base  60 . 
     As described above, the blocking member  43  is guided to the groove portion formed as described above as the slider  41  is moved in the left and right direction by being linked with the reciprocation of the carriage  16 , and the pin portion  43   a  is guided to any of the initial position, the first blocking position, and the second blocking position (collectively called the selection positions). In addition, in the state where the pin portion  43   a  is positioned at the first blocking position, the first pressing member  57 B is pressed downward by the pin portion  43   a  and thus squeezes the first discharge tube  35 , and in the state where the pin portion  43   a  is positioned at the second blocking position, the second pressing member  57 C is pressed downward by the pin portion  43   a  and thus squeezes the second discharge tube  37 . 
     Next, the structures of the first and second pressing members  57 B and  57 C will be described. In addition, in this embodiment, the first and second pressing members  57 B and  57 C have shapes which are symmetrical with respect to a vertical plane that widens in the upward and downward direction and the left and right direction as a symmetry plane. Therefore, here, the second pressing member  57 C is described representatively. 
     As illustrated in  FIG. 22 , the second pressing member  57 C is provided to be movable in the upward and downward direction with respect to the cam member  50  in the selective blocking mechanism  40  not illustrated in the same figure. In addition, the second pressing member  57 C includes a base portion  59   a  having an inclined surface portion  57   a  of which the upper end is exposed to the guide groove SL 2  and which is inclined in the upper right direction and a block shape portion  57   b  in which a compression spring  58  is embedded, and a tube pressing portion  59   b . The tube pressing portion  59   b  can slide in the upward and downward direction with respect to the base portion  59   a  via the compression spring  58 . 
     The tube pressing portion  59   b  has a predetermined width in the forward and rearward direction, the width thereof in the left and right direction is gradually narrowed toward the tip end portion (lower end portion), and the tip end (lower end) has roundness. In addition, the tip end is disposed to abut on the upper surface of the first discharge tube  35  in the selective blocking mechanism  40 . 
     Therefore, when the pin portion  43   a  of the blocking member  43  is moved as the arm portion is oscillated and is guided to the second blocking position, the inclined surface portion  57   a  at the upper end in the second pressing member  57 C can be pressed down by the pin portion  43   a . When the base portion  59   a  is pressed by this downward pressing, the compression spring  58  is compressed, and the tube pressing portion  59   b  squeezes the second discharge tube  37  by the compression of the compression spring  58 . In addition, as the slider  41  maintains a state without movement, the state of squeezing the second discharge tube  37  is maintained. 
     As such, in the selective blocking mechanism  40 , the blocking member  43  is rotated by reciprocating the slider  41  so as to move the pin portion  43   a  to the selection position, thereby selecting the discharge tube to be squeezed. As such, any of the second discharge tube  37  and the first discharge tube  35  is squeezed in front of the confluence point G provided on the path of the first discharge tube  35 . Originally, in the case where the selection position of the pin portion  43   a  is the initial position, both the second discharge tube  37  and the first discharge tube  35  are not in the squeezed state. 
     The suction operation of the ink performed in the printer  11  using the maintenance device  23  configured as described above will be described with reference to  FIGS. 23 to 25 . 
     As shown in  FIG. 23 , first, the carriage  16  is moved to the maintenance area MA (second maintenance position MP 2 ) (Step S 1 ). That is, the carriage  16  is moved to the left by rotating the carriage motor  18  (see  FIG. 1 ), and as illustrated in  FIG. 24 , the lever member  79  is rotated by moving the cap holding member  71  to the left, thereby moving the engagement member  110  in the clutch mechanism  100  to the left. In addition, in this state, the selective blocking mechanism  40  is in the lowered position, and thus the engagement portion  42  of the slider  41  is not engaged with the concave portion  16   h  of the carriage  16  and does not impede the movement of the carriage  16 . 
     Next, by rotating the fourth transmission gear  87  in the forward and reverse directions in a predetermined order through the rotation of the motor  26 , the clutch shaft  101  is rotated to set the clutch mechanism  100  to the ON state (Step S 2 ). That is, the protruding portion  103  is rotated to the state of being engaged with the first engagement portion  113  to the state of being engaged with the second engagement portion  114 . 
     Next, the carriage  16  is moved to the left from the maintenance area MA (the second maintenance position MP 2 ) to the position engaged with the slider  41  (Step S 3 ). Specifically, as illustrated in  FIG. 25 , in a plan view from above, the carriage  16  is moved to enter the state where the engagement portion  42  of the slider  41  is positioned in the area of the concave portion  16   h  of the carriage  16  in the plan view. In addition, in this embodiment, the concave portion  16   h  is formed at the left end portion of the carriage  16  such that the carriage  16  is at least engaged with the engagement portion  42  of the slider  41  at a position separated from the locking portion  71   a  of the cap holding member  71  to the left. 
     Since the cap holding member  71  is moved to the left by this movement of the carriage  16 , pressing of the lever member  79  against the upper end portion  79   c  is released, so that the engagement member  110  in the clutch mechanism  100  is moved to the right on the basis of the impelling force of the second coil spring  124 . As a result, the protruding portion  103  abuts on the groove bottom surface  114 B of the second engagement portion  114  and is in the state of being engaged with the second engagement portion  114  (that is, the ON state). Originally, during the movement of the carriage  16 , the lock lever  84  is at the retreat position that does not restrict the movement of the carriage  16 . 
     Next, the selective blocking mechanism  40  is raised by rotating the clutch shaft  101  (Step S 4 ). That is, by causing the fourth transmission gear  87  to undergo the CW rotation by rotating the motor  26 , the clutch shaft  101  is rotated, such that the rack slider  65  is moved forward via the clutch gear  122 . Accordingly, the selective blocking mechanism  40  is raised. 
     Next, the suction passage to be blocked is selected by reciprocating the carriage  16  (Step S 5 ). For example, in the case where the nozzle row  22 A that ejects black ink is suctioned, the cap internal space to be suctioned in the printer  11  is the first cap internal space  31   a , so that the second discharge tube  37  other than the first discharge tube  35  communicating with the first cap internal space  31   a  needs to be squeezed. Consequently, the slider  41  is reciprocated so that the selection position of the pin portion  43   a  of the blocking member  43  is the second blocking position so as to squeeze the second discharge tube  37 . 
     Next, the selective blocking mechanism  40  is lowered by rotating the clutch shaft  101  (Step S 6 ). That is, by rotating the clutch shaft  101  by causing the fourth transmission gear  87  to undergo the CCW rotation through the rotation of the motor  26 , the rack slider  65  is moved rearward via the clutch gear  122 . Accordingly, the selective blocking mechanism  40  is lowered. In this manner, the engagement of the carriage  16  with the engagement portion  42  of the slider  41  is released, and in the selective blocking mechanism  40 , the pin portion  43   a  of the blocking member  43  is in the state of being maintained at the selection position (for example, the second blocking position). 
     Next, the carriage  16  is moved to the maintenance area MA (the second maintenance position MP 2 ) again (Step S 7 ). Then, the carriage  16  is moved to the left by the carriage motor, and as illustrated again in  FIG. 24 , the cap holding member  71  is moved to the left, such that the lever member  79  is rotated and the engagement member  110  in the clutch mechanism  100  is moved to the left. At the same time, the cap  27  is in a state of surrounding and abutting on the nozzle rows  22 A to  22 D in the liquid ejecting head  19 . 
     Next, by causing the fourth transmission gear  87  to undergo the CCW rotation and rotating the clutch shaft  101  through the rotation of the motor  26 , the clutch mechanism  100  is caused to be in the OFF state (Step S 8 ). By this operation, the rotation of the motor  26  is not transmitted to the rotation of the clutch member  120 . Therefore, the selective blocking mechanism  40  is maintained in the lowered state regardless of the rotation of the motor  26 . In addition, in this state, here, the carriage  16  is moved to the first maintenance position MP 1  from the second maintenance position MP 2 . In this manner, the clutch mechanism  100  is in the OFF state while the cap  27  is maintained in the state of abutting on the liquid ejecting head  19 . 
     Next, the tube pump is driven (Step S 9 ). That is, by causing the motor  26  to undergo the CCW rotation, the tube pump  38  is subjected to a suction operation so as to suction the cap internal space. As a result, the cap internal space to be suctioned (for example, the first cap internal space  31   a ) is suctioned. 
     According to the embodiments described above, the following effects can be obtained. 
     (1) In an area which is on the path of the movement to the maintenance area MA (the first maintenance position MP 1 ) where suction is performed by causing the cap  27  to abut thereon, the internal space of the cap  27  is selected to be in a negative pressure state, and the carriage  16  can be moved to the maintenance area MA while maintaining the blocked state of the suction passage corresponding to the selected internal space. As a result, maintenance of the liquid ejecting head  19  can be appropriately performed without a reduction in the suction characteristics of the cap  27 . In addition, the movement midway area where the suction passage to be blocked is selected is caused not to overlap with an area where the carriage  16  abuts on and moves the cap holding member  71 , so that an increase in the load caused by the movement of the carriage  16  can be suppressed. 
     (2) Since the position of the slider  41  in the case where the engagement between the carriage  16  and the slider  41  is released is specified to be any selection position of the initial position, the first blocking position, and the second blocking position, when the engagement portion  42  of the slider  41  is engaged with the carriage  16  thereafter, the carriage  16  (the concave portion  16   h ) can be easily engaged with the engagement portion  42 . In addition, by switching the suction passage to be blocked by reciprocation, the initial position, the first blocking position, and the second blocking position can be the same position in the movement direction of the slider  41 . Therefore, regardless of the selected state of the suction passage, the carriage  16  and the slider  41  can be engaged with each other so as to be linked with each other at a fixed position in the movement midway area. 
     (3) When the engagement between the carriage  16  and the slider  41  is released, the slider  41  is impelled so that the blocking member  43  is moved to the initial position, the first blocking position, or the second blocking position by the coil spring  61 . As a result, for example, in the case where the engagement between the carriage  16  and the slider  41  is released on the path of the movement of the carriage  16 , the position of the slider  41  is moved to a position that can be specified such as the initial position by the coil spring  61 , so that in the case where the engagement portion  42  of the slider  41  is engaged with the carriage  16 , the carriage  16  can be easily engaged with the engagement portion  42 . 
     (4) During the process of ejecting ink onto a sheet P, using the moving operation of the carriage  16 , the internal space of the cap  27  to be suctioned can be selected in advance. Therefore, after ending printing, nozzles which are objects of maintenance can be immediately suctioned for maintenance. 
     (5) By displacing the lever member  79 , the clutch member  120  can be caused to be rotatably driven or not to be rotatably driven by the driving force from the motor  26 . Therefore, for example, when the clutch member  120  is moved in the axial direction by moving the lever member  79  using the moving operation of the carriage  16 , whether or not the power of the motor  26  is transmitted can be switched between by absence or presence of the rotation of the clutch member  120 . In addition, the engagement member  110  is impelled so that the state of engagement between the protruding portion  103  and any of the first and second engagement portions  113  and  114  is always maintained by the second coil spring  124  via the clutch member  120 . Therefore, the power transmission state of the switched motor  26  can be maintained regardless of the movement position of the carriage  16 . 
     (6) For example, the engagement member  110  can be pressed using the moving operation of the carriage  16  that is moved at a position distant from the clutch mechanism  100  by the lever member  79 . In addition, the engagement member  110  can be moved in the reverse direction to the movement direction of the carriage  16 . Moreover, in the case where the upper end portion  79   c  is moved by the movement of the carriage  16 , an increase in the load that occurs when the carriage  16  is moved with respect to the load of the lower end portion  79   b  for moving the engagement member  110  can be suppressed. Otherwise, the movement amount of the engagement member  110  with respect to the movement amount of the carriage  16  can be increased. 
     (7) The clutch member  120  is moved by being linked with the movement of the engagement member  110  via the first coil spring  119 , and the clutch member  120  and the engagement member  110  can be caused to approach each other by the compression of the first coil spring  119 . Therefore, for example, even in the case where before the driven-side protruding portion  123  of the clutch member  120  is moved to the engagement position so as to rotate integrally with the driving-side protruding portion  126  during the movement to the left, the end surfaces thereof abut on each other and the driven-side protruding portion  123  cannot be moved to the left, the driven-side protruding portion  123  and the driving-side protruding portion  126  can be engaged with each other so as to rotate integrally with each other. That is, when the engagement member  110  is moved to the left so as to approach the clutch member  120  by the lever member  79  and the clutch member  120  and the fourth transmission gear  87  are caused to rotate relative each other, the state of the driving-side protruding portion  126  and the driven-side protruding portion  123  abutting on each other is released. As a result, by elongating the first coil spring  119 , the clutch member  120  can be moved to the left to cause the driving-side protruding portion  126  and the driven-side protruding portion  123  to be engaged with each other. 
     (8) Through the movement of the clutch member  120  to the left, the driven-side protruding portion  123  is moved in the axial direction of the clutch shaft  101  so as to be engaged with the driving-side protruding portion  126  in the rotation direction, so that driving transmission between the driving-side protruding portion  126  and the driven-side protruding portion  123  can be performed. Therefore, since the movement amount in the axial direction is enough for the occupied space needed for the engagement, the space needed for the engagement is suppressed, and rotation is transmitted by the engagement between the protruding portions, so that the possibility that rotation is stably transmitted is increased. 
     (9) The transmission of the motor  26  is transmitted as needed by the rotation of the clutch member  120 , so that the rack slider  65  can be reliably moved. Therefore, for example, in the case where the selective blocking mechanism  40  is moved upward and downward by the rack slider  65 , the rack slider  65  can be reliably moved so as to move the selective blocking mechanism  40  upward and downward without being limited by the movement position of the carriage  16 . 
     (10) The rack slider  65  is formed in one body without an impelling unit being configured as an additional component, so that the clutch mechanism  100  can be suppressed from being complicated. 
     In addition, the above-described embodiments may be modified to other embodiments as follows. 
     In the embodiments, for example, as illustrated in  FIG. 26 , a selective blocking mechanism  40   a  may have a shape which is symmetrical with respect to the vertical plane in the upward, downward, forward, and rearward directions. That is, the movement of the slider  41  to the left is restricted, and in the state where the movement is restricted, the pin portion  43   a  of the blocking member  43  may be positioned at the initial position, the first blocking position, or the second blocking position. 
     In addition, when this selective blocking mechanism  40   a  is used, a concave portion  16   h  is provided at a position where the engagement portion  42  of the slider  41  is included in a plan view from above in the state where the carriage  16  is moved to the maintenance area MA to be subjected to maintenance. That is, in the carriage  16 , in addition to the concave portion  16   h  engaged with the engagement portion  42  when the slider  41  is reciprocated, another concave portion  16   h  is provided. In addition, in the state where the carriage  16  is moved to the maintenance area MA so as to be subjected to maintenance, when the selective blocking mechanism  40   a  is raised, the engagement portion  42  of the slider  41  in the state where the movement thereof to the left is restricted is engaged with the concave portion  16   h  in the upward and downward direction. By this engagement, the engagement portion  42  of the slider  41  functions as a movement restriction unit that restricts the movement of the carriage  16 . 
     According to this modified example, in addition to the effects (1) to (4) of the above-described embodiments, the following effects are exhibited. 
     (5) By engaging the carriage  16  moved to the specific position (for example, the first maintenance position MP 1 ) in the maintenance area MA with the engagement portion  42  of the slider  41  in the movement restricted state in the selective blocking mechanism  40   a , the carriage  16  can be restricted so as not to move in a direction from the maintenance area MA to the printing area PA. Therefore, since the engagement portion  42  of the slider  41  can be caused to function as a lock unit of the carriage, for example, the lock lever  84  in the embodiment becomes unnecessary. 
     In the embodiment, without the use of the reciprocation of the carriage  16 , the discharge tube to be squeezed may be selected according to a position of the carriage  16  in the left and right direction. An example of this modified example will be described with reference to  FIGS. 27A and 27B . 
     As illustrated in  FIG. 27A , a selective blocking mechanism  40 A of this modified example includes a movement body  41 A which is engaged with the concave portion  16   h  of the carriage  16  and is moved in the left and right direction, a base  60 A in which the first and second discharge tubes  35  and  37  are arranged, a first pressing member  57 E, and a second pressing member  57 F. On the lower surface of the movement body  41 A, an overhung portion  41 AC having a substantially semicircular shape in a front view is formed. In addition, the first pressing member  57 E is disposed so as to be movable in the upward and downward direction in the base  60 A, the lower end surface thereof abuts on the upper side of the first discharge tube  35 , and the upper end portion of which angular portions in the left and right direction are chamfered protrudes upward from the base  60 A. Similarly, the second pressing member  57 F is disposed so as to be movable in the upward and downward direction in the base  60 A, the lower end surface thereof abuts on the upper side of the second discharge tube  37 , and the upper end portion of which angular portions in the left and right direction are chamfered protrudes upward from the base  60 A. 
     Therefore, as illustrated in  FIG. 27B , in the selective blocking mechanism  40 A of this modified example, for example, as the movement body  41 A is engaged with the concave portion  16   h  of the carriage  16  and is moved in the left and right direction (in the figure, in the left direction), the overhung portion  41 AC is positioned at the disposition position of the second pressing member  57 F. Then, the second pressing member  57 F is pressed downward, and the lower end surface thereof squeezes the second discharge tube  37 . In this state, as the movement body  41 A is separated from the carriage  16  to release the engagement with the carriage, the state where the second discharge tube  37  is squeezed by the selective blocking mechanism  40 A is maintained. 
     In addition, although not shown in the figure, when the overhung portion  41 AC is moved to the disposition position of the first pressing member  57 E from the disposition position of the second pressing member  57 F, the second pressing member  57 F is in a state of not being squeezed by the overhung portion  41 AC. Therefore, the second pressing member  57 F is raised by the restoring force of the second discharge tube  37 , and the second discharge tube  37  returns substantially to its original state before being squeezed from the squeezed state by the restoring force. This is similar to the first pressing member  57 E and the first discharge tube  35 . 
     Therefore, according to the configuration of this modified example, the discharge tube to be squeezed can be selected without the reciprocation of the carriage  16 , so that the carriage  16  is less moved and a load caused by the movement of the carriage  16  is reduced. 
     In this embodiment, another example of the modified example in which the discharge tube to be squeezed is selected according to the position of the carriage  16  in the left and right direction without the use of the reciprocation of the carriage  16  will be described with reference to  FIG. 28 . 
     As illustrated in  FIG. 28 , a selective blocking mechanism  40 B of this modified example includes a rack member  41 B which is reciprocated, and a first cam  43 G and a second cam  43 H which are rotated integrally with a rotation shaft portion J of a pinion HG engaged with the rack of the rack member  41 B. Furthermore, a first pressing member  57 G which is moved downward as the upper end surface thereof is pressed by the first cam  43 G during the rotation of the rotation shaft portion J, and a second pressing member  57 H which is moved downward as the upper end surface thereof is pressed by the second cam  43 H are included. In addition, the lower end surface of the first pressing member  57 G is disposed to abut on the upper side of the first discharge tube  35  and the lower end surface of the second pressing member  57 H is disposed to abut on the upper side of the second discharge tube  37 . Moreover, the first and second cams  43 G and  43 H are mounted to the rotation shaft portion J so as not to press the first and second pressing members  57 G and  57 H at the same time. 
     Therefore, in the selective blocking mechanism  40 B of this modified example, for example, as an engagement portion  42 B provided in the rack member  41 B is engaged with the concave portion  16   h  of the carriage  16  and thus the rack member  41 B is moved in the left and right direction (in the figure, in the left direction), the pinion HG is rotated. Then, the rotation shaft portion J is rotated and thus the first and second cams  43 G and  43 H are rotated, so that any of the discharge tubes can be squeezed. For example, as illustrated in  FIG. 28 , when the first pressing member  57 G is pressed downward by the first cam  43 G, the lower end surface thereof squeezes the first discharge tube  35 . In this state, by releasing the engagement between the rack member  41 B and the carriage, the state of the first discharge tube  35  being squeezed in the selective blocking mechanism  40 B is maintained. 
     In addition, although not shown in the figure, when the first cam  43 G is rotated and the first pressing member  57 G is in the state of not being pressed downward, the first pressing member  57 G is raised by the restoring force of the first discharge tube  35 , and the first discharge tube  35  returns substantially to its original state before being squeezed from the squeezed state by the restoring force. This is similar to the second pressing member  57 H and the second discharge tube  37 . Therefore, according to the configuration of this modified example, the discharge tube to be squeezed can be selected without the reciprocation of the carriage  16 , so that the carriage  16  is less moved and a load caused by the movement of the carriage  16  is reduced. 
     In this embodiment, as a structure in which the engagement between the rack  66  of the rack slide  65  and the clutch gear  122  of the clutch member  120  is maintained, an elastic deformation portion which is impelled so that the displacement thereof is returned in the movement direction of the rack slider  65  is formed in the rack slider  65 . This modified example will be described with reference to  FIG. 29 . 
     As illustrated in  FIG. 29 , the rack slider  65  of this modified example, at positions at both ends of the movement range thereof when the selective blocking mechanism  40  is elevated, a flexible shape portion  65   e  and a flexible shape portion  65   f  which can be elastically deformed are provided. As shown by the solid line arrow in the figure, the flexible shape portion  65   e  has a cantilever beam shape cut and raised from the flat plate portion  65   a  having a substantially flat plate shape, at the rear end portion of the rack slider  65  so that during the forward movement of the rack slider  65 , the flexible shape portion  65   e  abuts on the frame body  29  (not shown in the same figure) and is thus displaced rearward in the upward direction. In addition, as shown by the broken line arrow in the figure, the flexible shape portion  65   f  has a substantially S-shaped cantilever beam shape which uses the right portion in the rack slider  65  as the base end portion so that the front end portion thereof is displaced forward as the flexible shape portion  65   f  abuts on the frame  29  (not shown in the same figure). 
     Therefore, when the rack slider  65  is moved forward in order to raise the selective blocking mechanism  40 , the flexible shape portion  65   e  is displaced at the ending end of the movement range to impel the rack slider  65  rearward, so that the rack  66  and the clutch gear  122  always maintain the engagement. In addition, when the rack slider  65  is moved rearward in order to lower the selective blocking mechanism  40 , the flexible shape portion  65   f  is displaced at the ending end of the movement range to impel the rack slider  65  forward, so that the rack  66  and the clutch gear  122  always maintain the engagement. 
     In the embodiment, as a structure in which the engagement between the rack  66  of the rack slider  65  and the clutch gear  122  of the clutch member  120 , the clutch gear  122  in the clutch member  120  may be configured as two gears. For example, as illustrated in  FIG. 30 , the clutch gear  122  may be configured of a clutch gear  122   a  formed in the clutch body  121 , and a clutch gear  122   b  formed separately from the clutch body  121 . 
     In this modified example, in the clutch body  121  in which the clutch gear  122   a  is formed, a convex portion  121   c  is formed to protrude from the right end in the left direction in a trapezoidal shape, and in the clutch gear  122   b , a convex portion  122   c  is formed to protrude from the left side in a trapezoidal shape in the left direction so as to be engaged with the convex portion  121   c  in the rotation direction. In addition, the clutch gear  122   b  is impelled to the left by the first coil spring  119 , and the clutch gear  122   a  (the clutch body  121 ) is impelled to the right by the second coil spring  124  having a compression force which is weaker than the first coil spring. In addition, in this impelled state, the clutch gear  122   b  is disposed at a position engaged with the four rack teeth  66   a ,  66   b ,  66   b , and  66   c  by the first coil spring  119 , and the clutch gear  122   a  is disposed at a position engaged with the two rack teeth  66   b.    
     With this configuration, for example, in the case where the rack slider  65  is moved forward, as illustrated in  FIG. 30 , the clutch gears  122   a  and  122   b  are rotated together by the convex portions  121   c  and  122   c  in the engaged state in the rotation direction (the arrow in the figure), thereby moving the rack slider  65 . In addition, the clutch gear  122   a  is in the state of not being engaged with the rack tooth  66   c  at the ending end in the movement range. In this state, when the rotation of the clutch body  121  is continued, the second coil spring  124  which has a weaker compression force than the first coil spring  119  is subjected to compression deformation, so that the convex portion  121   c  is moved to the left along the inclined surface portion of the trapezoid and rides over the convex portion  122   c . As a result, the clutch gear  122   a  idles, and the clutch gear  122   b  enters a state to which the rotation of the clutch body  121  is not transmitted, and thus the state of being engaged with the rack  66  (the rack tooth  66   c ) is maintained. 
     In the embodiment, during the ON state of the clutch mechanism  100 , rotation may be transmitted to the clutch member  120  from a rotation unit engaged in a direction intersecting the axial direction of the clutch shaft  101  may be transmitted. For example, as illustrated in  FIG. 31 , the clutch member  120   a  of this modified example has, at the left end portion thereof, a spur gear  123   a  with teeth extending on the outer peripheral surface in the left and right direction. In addition, a spur gear  126   a  as a rotation unit is disposed which is engaged with the spur gear  123   a  when the clutch member  120   a  is biased to the left and the clutch mechanism  100  enters the ON state, and of which engagement with the spur gear  123   a  is deviated when the clutch member  120   a  is biased to the right and the clutch mechanism  100  enters the OFF state. Therefore, the spur gear  126   a  functions as the driving-side protruding portion in the embodiment, and the slur gear  123   a  functions as the driven-side protruding portion in the embodiment. 
     According to the configuration of this modified example, the engagement with the spur gear  126   a  which is on the driving side can be selected by the movement amount of the clutch member  120   a  in the left and right direction. Therefore, for example, when a plurality of spur gears  126   a  on the driving side are provided, by controlling the movement amount of the clutch member  120   a , the spur gear  126   a  that has to transmit the rotation to the clutch member  120   a  can be caused to be engaged. 
     In the embodiment, the elevation driving of the selective blocking mechanism  40  may be performed using the power of the paper feeding motor  14  (see  FIG. 1 ). During maintenance of the liquid ejecting head, since printing is not performed, the power of the paper feeding motor  14  may be used in a state where a load caused by a paper feeding operation is reduced. 
     In the embodiment, the coil spring  61  may not be necessarily included. For example, in a case where there is a high possibility that the slider  41  is positioned at the initial position, the first blocking position, or the second blocking position when the reciprocation of the slider  41  is ended and the engagement portion  42  is lowered to release the engagement with the carriage  16 , this can be realized. 
     In the embodiment, a forward and rearward movement mechanism which causes the selective blocking mechanism  40  to be moved rearward with respect to the carriage  16  so as to approach or to be moved forward so as to be separated may be configured as a separation and approach movement unit. In this case, the engagement portion  42  of the slider  41  may be configured to protrude rearward, and the concave portion  16   h  of the carriage  16  may be configured to have an opening portion in the forward direction. 
     In the embodiment, the clutch mechanism  100  may not necessarily have the first coil spring  119 . For example, when the clutch mechanism  100  is switched from the OFF state to the ON state as the driving-side protruding portion  126  and the driven-side protruding portion  123  have triangular shapes or the like, in a case where the driven-side protruding portion  123  and the driving-side protruding portion  126  do not abut on each other in the left and right direction, the first coil spring  119  is unnecessary. 
     In the embodiment, a displacement member may not necessarily be the lever member  79 . For example, in the clutch mechanism  100 , in a case where the engagement member  110  is moved in the same direction as the carriage  16  (the cap holding member  71 ), a slide member may be employed. In this case, although not shown, in the lever member  79 , the rotation shaft portion  79   a  may be provided so that the point of effort and the point of action are positioned on the same side. 
     In the embodiment, the clutch gear  122  may rotate, other than a slide member such as the rack slider  65 , a rotation member (for example, a pump transmission gear  88  or the like). In this manner, the tube pump  38  can be rotated as needed. 
     In the embodiment, as the rotation unit, a rotation body other than the fourth transmission gear  87  may be included. For example, a pulley other than the gear may be included as the rotation body, or the pinion  26   a  of the motor  26  may be included as the rotation unit. 
     In the embodiment, in the maintenance area MA, the first maintenance position MP 1  and the second maintenance position MP 2  may be the same position. For example, in a case of a configuration in which the tube pump can perform the suction driving without raising of the selective blocking mechanism  40  in the state where the clutch mechanism  100  in the ON state or can be switched between the ON state and the OFF state, there is no need to cause the positions of the first and second maintenance positions MP 1  and MP 2  to be different from each other. 
     In the embodiment, the liquid ejecting apparatus is embodied as the ink jet type printer  11  as an example and may also be embodied as a liquid ejecting apparatus which ejects or discharges a liquid other than ink. The liquid ejecting apparatus may also be used as various liquid ejecting apparatuses having liquid ejecting heads and the like which discharge a minute amount of liquid droplets. In addition, the liquid droplets represent liquid states discharged from the liquid ejecting apparatus, the liquid states including granular, tear-like, and thread-like shapes with trails. The liquid mentioned herein may be any material that can be ejected by the liquid ejecting apparatus. For example, the materials may be in a liquid phase, and may include liquid materials with high or low viscosities, sol, gel water, fluid-state materials such as inorganic solvents, organic solvents, solutions, liquid resins, and liquid metal (metallic melt), and in addition to liquids as a state of the material, a material in which particles of functional materials made of solids such as pigments or metallic particles are dissolved, dispersed, or mixed with the solvent. In addition, as a representative example of the liquid, there is the ink described above in the embodiment or a liquid crystal. Here, the ink may include various kinds of liquid compositions such as general water-based ink, oil-based ink, gel ink, hot-melt ink, and the like. Specific examples of the liquid ejecting apparatus may include liquid crystal displays, EL (electroluminescence) displays, surface light-emitting displays, and liquid ejecting apparatuses for ejecting liquid in which materials such as electrode materials used for manufacturing color filters and color materials are dispersed or dissolved. Otherwise, the liquid ejecting apparatus may be liquid ejecting apparatuses for ejecting biological organic materials used for manufacturing biochips, liquid ejecting apparatuses which are used as precision pipettes and eject liquids as specimens, printing apparatuses, and microdispensers. Moreover, liquid ejecting apparatuses for ejecting lubricating oil to precision machinery such as watches or cameras with pinpoint precision, liquid ejecting apparatuses for ejecting transparent resin liquids such as ultraviolet curable resin on substrates to form micro-hemispherical lenses (optical lenses) or the like used for optical communication elements or the like, and liquid ejecting apparatuses for ejecting acidic or alkaline etchants for etching substrates or the like may be employed. In addition, the invention can be applied to any kind of liquid ejecting apparatus therefrom.