Patent Publication Number: US-7722155-B2

Title: Rotor, drive converting apparatus, cleaning apparatus, wiping apparatus, and liquid ejection apparatus

Description:
This is a Divisional of application Ser. No. 10/502,585 filed Jul. 27, 2004, now U.S. Pat. No. 7,182,426, which is a National Stage Application under §371 of PCT Application No. PCT/JP03/08676 filed Jul. 8, 2003. The entire disclosure of the prior application is hereby incorporated by reference. 

   FIELD OF THE INVENTION 
   The present invention relates to a rotor, a drive converting apparatus, a cleaning apparatus, a wiping apparatus and a liquid ejection apparatus that have these apparatuses. 
   BACKGROUND OF THE INVENTION 
   As a conventional liquid ejection apparatus which ejects a liquid on to a target, there is, for example, an ink jet type printer which prints an image or the like by ejecting ink droplets on to a page. This type of printer has a carriage member having a recording head and a platen which supports a target, for example, paper. The recording head has a plurality of nozzles which eject inks. Paper is guided between the recording head and the platen and inks are ejected onto the paper from the nozzles. This printer is generally provided with a cleaning apparatus to clean the nozzles in order to prevent ink clogging in the nozzles. The cleaning apparatus includes a cap apparatus having a cap which covers the recording head, a tube pump to be connected to the cap apparatus and a wiping apparatus having a wiping member for cleanly wiping inks adhered to the recording head. The wiping apparatus wipes the recording head clean by causing the wiping member to slide in contact with the recording head. 
   The cleaning operation of the printer will be described in detail. First, after the carriage is moved to a position at which the recording head faces the cap apparatus, the recording head is covered tightly with the cap. Subsequently, the tube pump is driven to suck out the inks, which become highly viscous and may cause clogging in the nozzles, together with air inside the cap and discharge the inks outside the nozzles. While the tube pump is driven, the wiping member is placed at a predetermined position where the recording head can be wiped. When the suction of the tube pump is finished, the cap is moved downward after which the carriage is moved to cause the recording head to slide in contact with the wiping member, thereby wiping the recording head. 
   In such a cleaning apparatus, a drive source for driving the cap apparatus, the tube pump and the wiping apparatus is common for making the printer compact. As compared with the driving of the tube pump, however, the cap apparatus and the wiping apparatus are driven only for a short period of time and their timings differ. Therefore, the tube pump is constructed to be driven on the drive force directly received from the drive source, whereas the cap apparatus and the wiping apparatus are driven via a drive converting apparatus using part of the drive force from the drive source. (See, for example, Japanese Laid-Open Patent Publication No. 2000-153617 and Japanese Laid-Open Patent Publication No. 2002-225299.) Those publications disclose printers that use a drive converting apparatus which drives the tube pump and wiping member with a single motor. 
   In Japanese Laid-Open Patent Publication No. 2000-153617, for example, a pump wheel to drive the tube pump is arranged on one side of a gear to which the drive force of the motor is transmitted. As the gear rotates, the pump wheel rotates with the rotation of the motor to thereby drive the tube pump. Meanwhile, the wiping apparatus is arranged on the other side of the gear via a friction clutch as the drive converting apparatus. The drive force of the motor is transmitted to the wiping apparatus via the friction clutch, moving the wiping member to a predetermined position. The friction clutch is operated intermittently with respect to the driving of the tube pump. 
   In case of the publication described above, the drive force of the motor is transmitted to the wiping apparatus by the friction clutch alone. In the case where inks are adhered to a driven gear and the friction clutch, for example, the weights of the parts to be driven, i.e., the driven gear and the friction clutch, increase because of the adhered inks. Therefore, the frictional force needed to drive the wiping apparatus becomes greater so that even when the drive force of the motor is transmitted to the friction clutch, the wiping apparatus cannot be driven. 
   Japanese Laid-Open Patent Publication No. 2002-225299 discloses the printer which is provided with a drive shaft to drive the tube pump and the wiping apparatus. The drive shaft penetrates the center of the pump wheel of the tube pump. The tube pump is driven as the pump wheel is directly rotated according to the rotation of the drive shaft. The wiping apparatus has a first drive mechanism including a sun gear, a cleaner drive lever, a gear holding lever and a planetary gear which constitutes the drive converting apparatus, and a second drive mechanism different from the first drive mechanism. The drive shaft is fitted into the center of the sun gear. As the drive shaft rotates, the second drive mechanism is driven via the sun gear, positioning the wiper to a predetermined position. The first drive mechanism functions to intermittently operate the wiping apparatus with respect to the driving of the tube pump. Therefore, the drive converting apparatus in Japanese Laid-Open Patent Publication No. 2002-225299, unlike that in Japanese Laid-Open Patent Publication No. 2000-153617 can drive the wiping apparatus even if inks are adhered to those parts to be driven. 
   There was a case where printing defects would occur due to an increase in the viscosity of the ink caused by evaporation of a solvent, such as water, from the openings of the nozzles, adhesion of dust to the openings of the nozzles and mixing of bubbles in the ink caused by replacement of a cartridge, or the like. 
   To maintain the performance of the nozzles in the best condition, therefore, a nozzle protecting device equipped with the cap, which covers the nozzles of the recording head and the tube pump that sucks out ink, and bubbles or so in the cap covering the nozzles, is used. In the case where printing is not carried out over a long period of time, the nozzles are covered with the cap, thus preventing the ink from becoming dry. As needed, the tube pump is driven with the nozzles covered with the cap, setting the inside of the cap to a negative pressure, so that the ink whose viscosity is increased or bubbles or the like generated in the recording head by replacement or the like of the cartridge is discharged to the ink tank, thereby maintaining the performance of the nozzles in good condition. 
   If the tube pump is driven to set the inside of the cap to a negative pressure as mentioned above, the inks flow into the cap via the recording head and fill the inside of the cap. As those inks would become unnecessary at the time of performing printing, so-called air suction was performed to exhaust the inks into the ink tank by the tube pump while taking air inside the cap. Taking air inside the cap was executed while slightly separating the cap from the nozzles. 
   Recently, the sizes of ink jet type recording apparatuses (printers) are becoming rapidly smaller and demand for a greater degree of freedom for locating recording apparatuses is increasing. Recording devices are increasingly used in a state other than in a horizontal state, and if air suction is carried by the above-described method under such a usage, the inks would leak from the cap in the instant the cap is separated from the nozzles. As a result, the inside of the recording apparatus becomes dirty. 
   To ensure air suction even if the recording apparatus is placed in a state other than a horizontal state, therefore, air release means which causes the cap to communicate with air as needed while covering the nozzles is provided. The air release means can release the inside of the cap to air before the cap is separated from the nozzles, so that the inks can be exhausted outside without causing ink leakage. 
   One example of the nozzle protecting device having an air release means comprises a tube to communicate inside the cap with air and a valve which opens and closes the end portion of the tube. The nozzle protecting device is of a slide type whose slider elevates up and down as the carriage moves in the scan direction so that the cap covers the nozzles as it elevates according to the elevation of the slider. The opening/closing of the valve is executed according to the operation of the carriage in the scan direction and air is taken inside the cap as needed. 
   However, such air release means needs the tube suitable located and thus makes the structure of the nozzle protecting device complicated. Further, after the valve is opened or closed by the movement of the carriage, the inks inside the cap are exhausted by the tube pump. Therefore, the first drive means which drives the carriage and the second drive means which drives the tube pump should be driven separately, complicating the structure. 
   The slide type nozzle protecting device makes the space for the carriage in the scan direction larger, which is a factor to enlarge the device. Recently, therefore, an up/down movement type which can make the space smaller is becoming mainstream as compared with the slide type. For example, Japanese Laid-Open Patent Publication No. 2002-36578 discloses an up/down movement type nozzle protecting device provided with an air release valve. 
   The nozzle protecting device has a multi-stage rotary cam having a plurality of cams on the same shaft. The multi-stage rotary cam has a first cam to elevate the cap, a second cam to open and close an air communication valve as an air release means and a motor. As the drive force of the motor is transmitted to the multi-stage rotary cam and the gear of the tube pump, elevation of the cap, the opening/closing of the air communication valve and driving of the pump gear are carried out. And, the air communication valve is opened or closed with the cap covering the nozzles, after which the pump gear is driven to perform air suction. 
   The operations of the cap and the air communication valve have nothing to do with the movement of the carriage, and the cap, the air communication valve and the pump gear can be driven to perform air suction with a single motor, thereby simplifying the device. 
   While the nozzle protecting device disclosed in Japanese Laid-Open Patent Publication No. 2002-36578 is made simpler, however, it needs larger space for the multi-stage rotary cam so that the ink jet type recording apparatus is larger. 
   The drive converting apparatus disclosed in Japanese Laid-Open Patent Publication No. 2002-225299 is comprised of many parts. Accordingly, a heavy load is applied to the drive shaft that drives the wiping apparatus and the tube pump. 
   That is, a large drive force is needed to drive the wiping apparatus and the tube pump more reliably. Generation of large drive force requires the use of a larger motor. As size reduction of the drive converting apparatus, is eventually demanded together with size reduction of the recording apparatus, it will become difficult to use a large motor. 
   In the case where the target to be printed is a thick object, such as CD-ROM, it is necessary to make the distance from the platen to the recording head large. As the wiping apparatus is normally fixed to the printer, when the recording head is moved upward to make the distance from the platen to the recording head larger, the distance between the wiping member and the recording head changes. Accordingly, the slide pressure of the wiping member to the recording head changes, making it difficult to wipe the inks adhered to the recording head satisfactorily. 
   For example, Japanese Laid-Open Patent Publication No. 2002-264350 discloses a technique for reducing the wiping speed of the wiping apparatus or increasing the wiping ability of the wiping member to clean the recording head adequately even if the distance from the platen to the recording head is changed. 
   Even with the use of the technique disclosed in Japanese Laid-Open Patent Publication No. 2002-264350, however, it is difficult to sufficiently wipe and clean the recording head with the wiper when the distance from the platen to the recording head is changed. Therefore, there was a demand for a technique which would wipe and clean the recording head more satisfactorily with the wiping member even when the distance from the platen to the recording head is changed. 
   SUMMARY OF THE INVENTION 
   It is a first object of the present invention to provide a compact liquid ejection apparatus with a simple structure. A second object is to provide a liquid ejection apparatus which is unlikely to cause liquid leakage even in usage in a state other than a horizontal state. 
   To achieve the above objects, the present invention provides the following liquid ejection apparatus. The liquid ejection apparatus has a cap, a cap support member, drive means, elastic means and air release means. The cap support member supports the cap. The drive means drives the cap support member to move the cap toward a liquid ejection head and cover nozzles of the liquid ejection head with the cap. The elastic means intervenes between the cap support member and the cap. The elastic means changes a distance between the cap support member and the cap as the elastic means stretches with the cap covering the nozzles. The air release means opens and closes inside the cap covering the nozzles with respect to air in accordance with a change in the distance. 
   The present invention also provides the following rotor. The rotor has a partially toothed gear and a rotary member. The partially toothed gear has a plurality of teeth formed on a part of the circumferential surface thereof. The rotary member rotates according to rotation of the partially toothed gear. The partially toothed gear is coupled to the rotary member in such a way as to be permitted to rotate within a predetermined range. 
   The present invention also provides a drive converting apparatus equipped with the above-described rotor. The drive converting apparatus has a drive gear, and a driven gear which engages with the drive gear and urging means. The drive gear engages with the partially toothed gear of the rotor. Teeth are formed around the entire circumferential surface of the driven gear. The urging means urges the driven gear toward the partially toothed gear to transmit torque from the driven gear to the partially toothed gear. The torque of the driven gear rotates the partially toothed gear in a direction of engagement with the drive gear from a state where engagement with the drive gear is broken. 
   The present invention further provides a cleaning apparatus equipped with the above-described drive converting apparatus. The cleaning apparatus is equipped with wiper means having a wiping member and a wiper support member. The wiping member cleanly wipes a liquid ejection head having a plurality of nozzles for ejecting a liquid. The wiper support member supports the wiping member. The positioning member of the drive converting apparatus is coupled to the wiper support member. As the rotor of the drive converting apparatus rotates, the positioning member is lifted up and down to lift the wiping member up and down. 
   The present invention also provides the following wiping apparatus. The wiping apparatus has a wiping member which abuts on a liquid ejection head for ejecting a liquid and wipes the liquid injection head clean. There are a plurality of positions of action at which the wiping member wipes the liquid injection head clean. Wiper position adjusting means adjusts the plurality of positions of action. 
   The present invention also provides another liquid ejection apparatus. The liquid ejection apparatus has a platen which supports a target, a liquid ejection head which injects a liquid to the target, a wiping member which abuts on the liquid ejection head and wipes it clean, and wiper position adjusting means which adjusts the position of action of the wiping member based on a distance from the platen to the liquid ejection head. 
   The present invention provides a further liquid ejection apparatus. The liquid ejection apparatus has a platen which supports a target, a liquid ejection head which injects a liquid to the target, a wiping member which abuts on the liquid injection head and wipes it clean, and wiper position adjusting means which adjusts a position of action of the wiping member based on elevation of the liquid injection head. 
   The present invention also provides a wiping method for wiping the liquid ejection head clean, which ejects a liquid on to a target. The wiping method includes a step of adjusting the position of action of the wiping member based on a distance from a platen which supports the target to the liquid ejection head, and a step of causing the wiping member to abut on and wipe the liquid ejection head clean. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of an ink jet type recording apparatus according to a first embodiment embodying the present invention. 
       FIG. 2  is a perspective view of a nozzle protecting device equipped in the recording apparatus in  FIG. 1 . 
       FIG. 3  is a partly exploded perspective view of the nozzle protecting device in  FIG. 2 . 
       FIG. 4  is a partly exploded cross-sectional view of the nozzle protecting device in  FIG. 2 . 
       FIG. 5  is a partial cross-sectional view of the nozzle protecting device in  FIG. 2 . 
       FIG. 6  is a perspective view of a cylindrical cam provided in the nozzle protecting device in  FIG. 2 . 
       FIG. 7  is a diagram showing a state before a close-contact portion of the nozzle protecting device in  FIG. 2  abuts on a recording head. 
       FIG. 8  is a diagram showing a state where the close-contact portion in  FIG. 7  abuts on the recording head. 
       FIG. 9  is a diagram showing a state where a lever of the nozzle protecting device in  FIG. 2  protrudes outward. 
       FIG. 10  is a diagram showing a state where a cap of the nozzle protecting device in  FIG. 2  approaches its closest position to a cap support member. 
       FIG. 11  is a diagram showing a state where a valve body equipped in the nozzle protecting device in  FIG. 2  rotates. 
       FIG. 12  is a side view of a nozzle protecting device according to a second embodiment of the present invention. 
       FIG. 13  is a side view showing a state where the nozzle protecting device in  FIG. 12  is provided with a partition. 
       FIG. 14  is a diagram showing a state where a cap support member is moved uppermost in the nozzle protecting device in  FIG. 12 . 
       FIG. 15  is a diagram showing a state where a projection provided in the nozzle protecting device in  FIG. 12  abuts on an abutment portion of the partition. 
       FIG. 16  is a front view of essential portions of a nozzle protecting device equipped in a recording apparatus according to a third embodiment embodying the present invention. 
       FIG. 17  is a plan view of the nozzle protecting device in  FIG. 16 . 
       FIG. 18  is an outline perspective view of the nozzle protecting device as seen from the tube pump side. 
       FIG. 19  is an outline perspective view of the nozzle protecting device as seen from the drive motor side. 
       FIG. 20(   a ) is a perspective view of a cylindrical cam and a wiping apparatus according to the third embodiment as seen from the bottom side. 
       FIG. 20(   b ) is a perspective view of the cylindrical cam and the wiping apparatus according to the third embodiment as seen from the bottom side. 
       FIG. 21  is a bottom view of the cylindrical cam and what lies around it. 
       FIG. 22  is a front view of the cylindrical cam. 
       FIG. 23  is an exploded perspective view of the cylindrical cam. 
       FIG. 24  is a bottom view of a partially toothed gear of a cylindrical cam according to a fourth embodiment. 
       FIG. 25  is a bottom view of the partially toothed gear of the cylindrical cam in  FIG. 24 . 
       FIG. 26  is a bottom view of the partially toothed gear of the cylindrical cam in  FIG. 24 . 
       FIG. 27  is a perspective view of a recording apparatus according to a fifth embodiment of the present invention. 
       FIG. 28(   a ) is a side view showing a gap between a platen and a recording head equipped in the recording apparatus in  FIG. 27 . 
       FIG. 28(   b ) is a side view showing a gap between the recording head moved upward from the state in  FIG. 28(   a ) and the platen. 
       FIG. 29  is a front view of the position of non-action of a wiping member equipped in the recording apparatus in  FIG. 27 . 
       FIG. 30  is a developed view of essential portions on the circumferential surface of a cylindrical cam in  FIG. 29 . 
       FIG. 31  is a front view of the first position of action of the wiping member in  FIG. 29 . 
       FIG. 32  is a front view of the second position of action of the wiping member in  FIG. 29 . 
       FIG. 33  is a developed view of the side of a cylindrical cam according to a sixth embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A first embodiment embodying the present invention will be described below with reference to  FIGS. 1 to 6 . 
   As shown in  FIG. 1 , an ink jet type recording apparatus  11  as a liquid ejection apparatus has a frame  12 , a platen  13  hung across the frame  12  and an unillustrated paper feeding mechanism equipped with a feed motor  14 . The platen  13  is a support to support paper P and the paper P fed by the driving of the feed motor  14  is led to the top surface. The feed motor  14  drives unillustrated rollers to feed the paper P supported on the platen  13  in the direction of the arrow y shown in  FIG. 1 . A waste liquid tank  40  which retains used inks is provided under the platen  13 . 
   A drive pulley  19  and a driven pulley  20  are fixed to the frame  12 . A reversible carriage motor  18  is coupled to the drive pulley  19 , A timing belt  17  is stretched around a pair of the pulleys  19  and  20 . A carriage  16  is fixed to the timing belt  17 . Further, a guide member  15  extending in parallel to the platen  13  is provided on the frame  12 . The guide member  15  extends in parallel to the axial line extending in the lengthwise direction of the platen  13 . The carriage  16  is supported on the guide member  15  in such a way as to be movable along the axial direction of the guide member  15 . The carriage  16  reciprocates along the guide member  15  via the timing belt  17  by the driving of the carriage motor  18 . 
   First and second ink cartridges  21  and  22  are detachably mounted on the carriage  16 . The first ink cartridge  21  retains a black ink. The second ink cartridge  22  respectively retains magenta, cyan and yellow inks in three defined retaining chambers. A recording head  28  as a liquid ejection head is provided under the carriage  16 . The recording head  28  has a plurality of unillustrated nozzles. A discharge port is provided in the bottom side of the nozzle. When an unillustrated piezoelectric element is driven based on print data, inks are supplied to the recording head  28  from both ink cartridges  21  and  22  and ink droplets are ejected toward the paper P from the discharge ports to perform printing. 
   A nozzle protecting device  30  for protecting the nozzles of the recording head  28  is provided at one side portion of the frame  12  which is the unprintable region (home position). The nozzle protecting device  30  also functions as a cleaning apparatus to clean the nozzles. 
   As shown in  FIGS. 2 and 3 , the nozzle protecting device  30  has a case  31 , a cap apparatus  32 , a wiping apparatus  34 , a cylindrical cam  35 , a tube pump  37  and a drive motor  38 . 
   The case  31  is a box with a shape approximately corresponding to a rectangular parallelepiped. The case  31  has a first retaining portion  41  which is open to the top and one side of the case  31  and a second retaining portion  42  which is open to the top of the case  31 . Both retaining portions  41  and  42  are arranged so as to adjoin each other. As shown in  FIG. 3 , a third retaining portion  43  is provided in the case  31  in such a way as to adjoin the retaining portions  41  and  42 . The third retaining portion  43  is closed by a lid  44 . An opening  45  is provided at the boundary between the third retaining portion  43  and the first retaining portion  41  and the second retaining portion  42 . 
   The cap apparatus  32  is retained in the first retaining portion  41 . The cap apparatus  32  has a box-shaped cap  46  and a cap support member  47  to be coupled to the cap  46 . The cap support member  47  has first to fourth sides  471 ,  472 ,  473  and  474 . The cap support member  47  is supported at the first retaining portion  41  in such a way as to be movable along the up and down direction of the first retaining portion  41 . 
   The cap  46  has an opening. The opening of the cap  46  has such a size as to be able to cover the nozzles of the recording head  28 . A close-contact portion  51  is provided at the periphery of the opening of the cap  46 . The close-contact portion  51  tightly connects the cap  46  to the recording head  28  when the cap  46  covers the nozzles of the recording head  28 . 
   An absorption member  52 , which is a sheet, is provided inside the cap  46 . The absorption member  52  functions in such a way that when the cap  46  covers the nozzles of the recording head  28 , the absorption member  52  retains the inks to keep the humidity inside the cap  46  high and prevent the ink from becoming dry. To prevent clogging of inks in the discharge ports at which there is not much discharge of ink droplets, the absorption member  52  receives inks dropping from the discharge ports at the time of a flashing operation of applying a drive signal irrelevant to printing to the recording head  28  whenever a given period elapses and ejects ink droplets. 
   Two exhaust ports  53  penetrating the bottom of the cap  46  are formed in the cap bottom. As shown in  FIG. 4 , each exhaust port  53  is connected to an associated ink tube  53   a . The ink remaining in the cap  46  is exhausted via each ink tube  53   a . Further, highly viscous ink, dust, bubbles or the like is sucked out of the nozzles via each ink tube  53   a  to clean the nozzles. 
   A vent hole  54  as a through hole is formed in the bottom of the cap  46 . The vent hole  54  functions to allow a flow of air into the cap  46 . In a state where the ink remaining in the cap  46  is exhausted, i.e., at the time of air suction to evacuate the inside of the cap  46 , air is led through the vent hole  54 . 
   As shown in  FIG. 5 , a cylinder portion  55  extends from the bottom of the cap  46 . The cylinder portion  55  surrounds the vent hole  54 . A valve seat  56  which surrounds the distal end of the vent hole  54  is provided at the lower end of the cylinder portion  55 . The valve seat  56  is formed of a flexible material, for example, an elastomer. 
   As shown in  FIGS. 4 and 5 , two bearings  57  are arranged at the lower portion of the cap  46  in such a way as to face each other. A valve body  58  is attached to both bearings  57  in such a way as to be rotatable around a shaft  62   a . The valve body  58  further includes a plate  61  extending in the lengthwise direction of the cap  46  and a support portion  62  provided near the center of the plate  61 . The shaft  62   a  is provided at the upper end of the support portion  62 . 
   A first portion of the plate  61  (the left-hand portion of the plate  61  in  FIG. 5 ) is coupled to the lower side of the cap  46  via a spring member  58   a  as an urging means. The spring member  58   a  normally urges the plate  61  of the valve body  58  downward. In the case where no external force is applied to the valve body  58 , the top surface of a second portion of the plate  61  (the right-hand portion of the plate  61  in  FIG. 5 ) abuts on the valve seat  56 , so that the vent hole  54  is sealed. A first inclined surface  61   a  inclined at a predetermined angle to the direction vertical to the cap support member  47  is formed at the end portion of the second portion of the plate  61 . 
   A first column portion  63  is protrusively provided at the third side  473  of the cap  46  and a second column portion  64  is protrusively provided at the second side  472  of the cap  46 . 
   The cap support member  47  is an approximately rectangular frame and the cap  46  is housed inside the cap support member  47 . As shown in  FIG. 5 , a first long groove  65  extending along the vertical direction in  FIG. 5  is formed in the third side  473  of the cap support member  47 . As shown in  FIGS. 4 and 5 , a second long groove  66  extending along the vertical direction in the drawing is formed in the side of the cap support member  47 . The column portions  63  and  64  of the cap  46  penetrate the associated long grooves  65  and  66  and are movable in the long grooves  65  and  66  along the vertical direction. The upper end of each associated long groove  65 ,  66  is cut away in such a way as to have a triangular cross section. 
   As shown in  FIG. 4 , a restriction plate  67   a  is provided at that portion of the cap support member  47  which is positioned nearly in the center in the widthwise direction thereof. The restriction plate  67   a  and the first side  471  of the cap support member  47  define an opening  67 . The opening  67  is provided at a position facing the tube pump  37 . A first short groove  68  having an approximately U-shaped cross section is formed in the second side  472  of the cap support member  47 . The first short groove  68  extends from the lower portion of the second side  472  of the cap support member  47  toward the upper portion. A second short groove  69  having an approximately U-shaped cross section is formed in the restriction plate  67   a . The second short groove  69  extends from the lower portion of the restriction plate  67   a  toward the upper portion. 
   As shown in  FIGS. 4 and 5 , a slide member  71  as a pressing member is provided at the opening  67 . The slide member  71  includes a columnar support rod  72 , a nearly columnar lever  73  and a link member  74 . The support rod  72  and lever  73  are fixed via the link member  74 . Both end portions of the support rod  72  are inserted into both short grooves  68  and  69  of the cap support member  47 . With those structures, the slide member  71  is movable along the lengthwise direction of the cap support member  47  and the movement of the slide member  71  in the direction of the arrow y shown in  FIG. 4  and the up and down direction of the cap support member  47  is restricted. 
   A second inclined surface  73   a  inclined relative to the vertical direction of the cap support member  47  is formed at a first end portion of the lever  73  (equivalent to the left-hand portion of the lever  73  in  FIG. 5 ). Meanwhile, a second end portion of the lever  73  (equivalent to the right-hand portion of the lever  73  in  FIG. 5 ) is inserted in a third long groove  75  formed in the second side  472  of the cap support member  47 . 
   The link member  74  is not movable in the vertical direction of the cap support member  47 . The link member  74  has a plate-like restriction portion  76  extending in a direction orthogonal to the axis of the support rod  72 . As the slide member  71  moves toward the widthwise center of the cap support member  47 , the restriction portion  76  abuts on the restriction plate  67   a  of the cap support member  47 . As a result, the movement of the slide member  71  along the widthwise direction of the cap support member  47  is restricted. 
   As shown in  FIG. 4 , the restriction portion  76  is provided with a projection  76   a  protruding in the direction of the arrow x in  FIG. 4 . As shown in  FIG. 5 , a spring member  77  as an urging means is provided between the projection  76   a  and the inner surface of the second side  472  of the cap support member  47 . The spring member  77  urges the slide member  71  leftward or toward the widthwise center of the cap support member  47 . In the case where external force is not applied to the slide member  71  the restriction portion  76  of the slide member  71  and the restriction plate  67   a  of the cap support member  47  abut on each other. 
   As shown in  FIG. 4 , a through hole  78  is formed in that portion of the first side  471  of the cap support member  47  which faces the drive motor  38 . A columnar positioning member  79  is inserted in the through hole  78 . The positioning member  79  is movable along the direction of the arrow y shown in  FIG. 4 . The positioning member  79  is connected to the cap support member  47  via an unillustrated spring member. The spring member urges the positioning member  79  in the direction of the arrow y shown in  FIG. 4 . 
   The cap  46  is coupled to the cap support member  47  via a spring member  80  as an elastic means as shown in  FIG. 5  in such a way that both column portions  63  and  64  of the cap  46  penetrate to the respective long grooves  65  and  66  of the cap support member  47 . The spring member  80  urges the cap  46  in such a way that the cap  46  and the cap support member  47  are separated from each other along the vertical direction of the cap support member  47 . The movements of the cap  46  in the direction of the arrow x and the direction of the arrow y shown in  FIG. 4  with respect to the cap support member  47  are restricted. 
   With no external force applied to the cap  46 , therefore, the distance between the cap  46  and the cap support member  47  in the vertical direction reaches a maximum. As shown in  FIG. 5 , the individual column portions  63  and  64  of the cap  46  abut on the upper end portions of the respective long grooves  65  and  66  of the cap support member  47 , thus restricting an increase in the distance between the cap  46  and the cap support member  47 . 
   With the cap  46  and the cap support member  47  coupled together, the inclined surface  61   a  of the valve body  58  (plate  61 ) of the cap  46  and the inclined surface  73   a  of the lever  73  are placed at positions facing each other with a predetermined distance therebetween. As will be discussed later, when the distance between the cap  46  and the cap support member  47  is at a minimum, the lever  73  is positioned above the plate  61 . When the distance between the cap  46  and the cap support member  47  is at the maximum, the lever  73  is positioned below the plate  61  and outside the movable range of the plate  61 . 
   As shown in  FIGS. 1 to 3 , the wiping apparatus  34  is housed in the second retaining portion  42  of the case  31  in such a way as to be movable in the vertical direction of the case  31 . The wiping apparatus  34  has a wiping member  81  which has an approximately rectangular parallelepiped shape and is formed of an elastic material. Therefore, when the carriage  16  is driven with the wiping apparatus  34  moved to the upper portion and the recording head  28  crosses above the wiping apparatus  34 , the wiping member  81  slides in contact with the recording head  28  to wipe the nozzles of the recording head  28  clean. 
   As shown in  FIG. 6 , the cylindrical cam  35  has an insertion hole  82  inside. An upper end portion  83  and a lower end portion  84  of the cylindrical cam  35  are both annular and extend in the diametrical direction of the cylindrical cam  35 . A plurality of teeth  85  having the same shape are formed at an equal pitch on only one circumferential half of the periphery of the upper end portion  83  of the cylindrical cam  35 . The remaining circumferential half of the upper end portion  83  of the cylindrical cam  35  has a smooth arcuate shape. A cam groove  86  is provided between the upper end portion  83  and the lower end portion  84  of the cylindrical cam  35 . The cam groove  86  is provided below that portion of the upper end portion  83  which has a smooth shape and is defined by fourteen, first to fourteenth surfaces  87  to  100 . 
   The cylindrical cam  35  is positioned in the opening  45  of the third retaining portion  43  as shown in  FIG. 3 . A shaft portion  102  fixed to the third retaining portion  43  is inserted into the insertion hole  82  of the cylindrical cam  35 . The cylindrical cam  35  rotates about the shaft portion  102 . With the cylindrical cam  35  inserted in the shaft portion  102 , the positioning member  79  (see  FIG. 4 ) of the cap support member  47  is engaged with the cam groove  86  of the cylindrical cam  35 . 
   As the cylindrical cam  35  is rotated in the direction of the arrow, as shown in  FIG. 6 , first, the positioning member  79  placed at the lowest position of the cam groove  86  (the position for contact with the lower end portion  84 ) is guided to the highest position by the first to third surfaces  87 ,  88  and  89  extending askew to the axial direction of the cylindrical cam  35 . As the cylindrical cam  35  is further rotated in the arrow direction, the positioning member  79  abuts on the sixth to eighth surfaces  92 ,  93  and  94  via the fourth and fifth surfaces  90  and  91  extending in parallel to the axial direction. The distances from the rotational center of the cylindrical cam  35  to the three surfaces  90 ,  91  and  92  become gradually longer. The positioning member  79  is pressed in the direction opposite to the direction of the arrow y (see  FIG. 4 ). 
   As the cylindrical cam  35  is rotated in the direction opposite to the arrow in  FIG. 6  thereafter, the positioning member  79  is guided to the sixth surface  92  and then abuts on the ninth surface  95  farther from the rotational center of the cylindrical cam  35  than the fourth surface  90 . Then, it is guided to the seventh surface  93  extending askew to the rotational direction and the cap support member  47  as a whole slides downward due to the dead weight. Thereafter, it abuts on the twelfth and thirteenth surfaces  98  and  99  through the tapered tenth and eleventh surfaces  96  and  97 . The distances of the three surfaces  95 ,  96  and  97  from the rotational center gradually become longer and the positioning member  79  is pressed further in the direction opposite to the direction of the arrow y (see  FIG. 4 ). 
   When the cylindrical cam  35  is rotated again in the direction of the arrow in  FIG. 6 , the positioning member  79  is guided to the twelfth and thirteenth surfaces  98  and  99 , positioned in parallel to the rotational direction, and abuts on the fourteenth surface  100 . When the cylindrical cam  35  is rotated in the direction opposite to the direction of the arrow thereafter, the positioning member  79  is guided to the twelfth and thirteenth surfaces  98  and  99  and then guided to the first and second surfaces  87  and  88 , and the cap support member  47  slides downward and is returned to the initial, lowest position due to the dead weight. The second surface  88  has a shorter distance from the rotational center than the twelfth surface  98  and the positioning member  79  is returned in the direction of the arrow y (see  FIG. 4 ) by the action of the spring member. The positioning member  79  is guided in the up and down direction by the rotation of the cylindrical cam  35  as described above. Accordingly, the cap support member  47  as a whole is moved in the up and down direction. 
   As shown in  FIG. 3 , the tube pump  37  is retained in the third retaining portion  43  of the case  31  in such a way as to not contact the cylindrical cam  35 . As shown in  FIG. 4 , the tube pump  37  has a pump wheel  105 , rotatably supported on a rotary shaft  104 , and a roller  106  which moves along an unillustrated support groove of the pump wheel  105 . The ink tubes  53   a  are positioned, partly overlapped, in the space between the third retaining portion  43  (see  FIG. 3 ) and the pump wheel  105 . In  FIG. 4 , the ink tube  53   a  is illustrated only partially for the sake of convenience. 
   As the pump wheel  105  is rotated in the forward direction, the roller  106  rotates while sequentially pressing the ink tubes  53   a . This depressurizes the inside of the ink tubes  53   a  on the upstream side of the tube pump  37 . 
   As the pump wheel  105  is rotated in the reverse direction, a release state where the roller  106  slightly contacts the ink tubes  53   a  is maintained. As a result, the pressure in the tube pump  37  becomes uniform over the entire tube pump  37 . Further, a shortcoming caused by adhesion or the like of the roller  106  and the ink tubes  53   a  is prevented. 
   As shown in  FIG. 3 , the drive motor  38  is housed in the third retaining portion  43  in such a way as to be rotatable forward and reversely. The forward/reverse rotation causes the drive force of the drive motor  38  to be transmitted to the wiping apparatus  34 , the cylindrical cam  35  and the tube pump  37  via first to fourth gears  107  to  110 . 
   A drive gear  38   a  is fixed to the distal end of the rotary shaft of the drive motor  38 . The drive gear  38   a  is coupled to the third gear  109  via the first gear  107  and the second gear  108  which are rotatably supported on the case  31 . The third gear  109  is fixed to the distal end of the rotary shaft  104  of the tube pump  37  retained in a retaining portion Kc of the case  31 . The third gear  109  is further coupled to the fourth gear  110  rotatably supported on the case  31 . Plural teeth of the fourth gear  110  are engaged with the teeth  85  of the cylindrical cam  35  shown in  FIG. 6 . 
   As the drive motor  38  is rotated forward, the drive force of the drive motor  38  is transmitted to the cylindrical cam  35  via the first to fourth gears  107 ,  108 ,  109  and  110  and the cylindrical cam rotates in the direction of the arrow as shown in  FIG. 6 . Because the plural teeth  85  are provided only on one circumferential half of the cylindrical cam  35 , they only rotate the cam by one-half of its circumference at maximum. When the forward rotation of the drive motor  38  is changed to the reverse rotation, the cylindrical cam  35  is rotated in the direction opposite to the direction of the arrow. The cylindrical cam  35  only rotates by one-half of its circumference at maximum this time again. 
   As shown in  FIG. 4 , the third gear  109  is so arranged as to overlap the upper side of the pump wheel  105  of the tube pump  37  and is rotatably supported on the rotary shaft  104 . A first projection  110   a  projects from the lower surface of the third gear  109 . Meanwhile, a second projection  105   a  is provided at the top surface of the pump wheel  105  and the first projection  110   a  and the second projection  105   a  are equal in distance from the rotary shaft  104 . The first projection  110   a  and the second projection  105   a  are provided in such a way as to partly overlap each other in the rotational direction of the rotary shaft  104 . In accordance with the relative positions of the fourth gear  110  and the pump wheel  105  in the rotational direction, the first projection  110   a  and the second projection  105   a  selectively abut on each other or move apart from each other. 
   When the forward rotation of the drive motor  38  rotates the third gear  109  in the forward direction so that the first projection  110   a  and the second projection  105   a  abut on each other, therefore, the torque of the third gear  109  is transmitted via the projections  105   a  and  110   a  to the pump wheel  105  so that the pump wheel  105  rotates forward. 
   When the forward rotation of the drive motor  38  is changed to the reverse rotation, the third gear  109  changes its forward rotation to the reverse direction, causing the first projection  110   a  and the second projection  105   a  to part from each other. Then, the rotation of the pump wheel  105  stops. When the third gear  109  makes nearly one turn thereafter, the first projection  110   a  and the second projection  105   a  abut on each other again to transmit the torque of the third gear  109  via the projections  105   a  and  110   a  to the pump wheel  105 , so that the pump wheel  105  rotates reversely. 
   That is, there is a time lag of nearly one turn of the third gear  109  set between the switching of the forward rotation of the drive motor  38  to the reverse rotation and the start of the reverse rotation of the pump wheel  105 . Likewise, there is a similar time lag set between the switching of the reverse rotation of the drive motor  38  to the forward rotation and the start of the forward rotation of the pump wheel  105 . 
   In the case where the drive motor  38  rotates reversely and then starts rotating forward, therefore, first, the cylindrical cam  35  makes half a rotation at maximum in the direction of the arrow in  FIG. 6 . As the drive motor  38  further rotates forward, the pump wheel  105  starts rotating forward with a delay. In the case where the drive motor  38  rotates forward and then starts rotating reversely, the cylindrical cam  35  makes half a turn at maximum in the direction opposite to the direction of the arrow in  FIG. 6 . As the drive motor  38  further rotates reversely, the pump wheel  105  starts rotating reversely with a delay. 
   The action of the nozzle protecting device  30  with the above-described structure will be described based on  FIGS. 7 to 11 . In  FIGS. 7 to 11 , the illustration of the cap support member  47  is limited only to the slide member  71  and the positioning member  79  for the sake of convenience. Further, the illustration of the individual spring members  58   a ,  77  and  80  is omitted for the sake of convenience. 
   First, a process of executing a cleaning operation and flashing operation is executed in the recording apparatus  11 , in which the carriage  16  is moved to the home position of the frame  12 . Then, as shown in  FIG. 7 , the recording head  28  of the carriage  16  faces the cap  46  of the nozzle protecting device  30 . In this state, the positioning member  79  is engaged with the cam groove  86  of the cylindrical cam  35  shown in  FIG. 6  at the lowest position; specifically, it abuts on the first surface  87  and the second surface  88  of the cam groove  86 . 
     FIG. 7  shows a state where the distance between the cap  46  and the positioning member  79  (cap support member  47 ) is maximum. The lever  73  included in the slide member  71  is arranged below the valve body  58  of the cap  46 . The plate  61  of the valve body  58  abuts on the valve seat  56  so that the vent hole  54  is closed. In this state, even when the flashing operation is performed and the inks inside the cap  46  are discharged, the inks are prevented from leaking from the vent hole  54 . 
   After the cleaning operation is carried out, the drive motor  38  is rotated forward and the drive force of the drive motor  38  is transmitted to the teeth  85  of the upper end portion  83  of the cylindrical cam  35  via all of the gears  107 ,  108 ,  109  and  110  (see  FIG. 3 ), causing the cylindrical cam  35  to rotate in the direction of the arrow in  FIG. 6 . Then, the positioning member  79  moves and rises while abutting on the second and third surfaces  88  and  89  of the cam groove  86  of the cylindrical cam  35 . 
   Then, the cap support member  47  rises in accordance with the rising of the positioning member  79 , the close-contact portion  51  of the cap  46  abuts on the recording head  28  and covers the recording head  28  as shown in  FIG. 8 . The upward movement of the cap  46  is restricted by the recording head  28 . Further, the spring member  80  provided between the cap  46  and the cap support member  47  elastically deforms, thus reducing the relative distance between the cap  46  and the cap support member  47 . 
   Consequently, as a predetermined time elapses, the inclined surface  61   a  of the plate  61  abuts on the inclined surface  73   a  of the lever  73 . Further, as the drive motor  38  is rotated forward to move the cap support member  47  upward, the resistance between the inclined surface  73   a  of the plate  61  and the inclined surface  61   a  of the lever  73  prevails against the elastic force of the spring member  77 , so that the spring member  77  elastically deforms, causing the lever  73  to move rightward as shown in  FIG. 9 . 
   As the positioning member  79  moves to the position in the cam groove  86  of the cylindrical cam  35  shown in  FIG. 6  where the third surface  89  and the fourth surface  90  abut on each other, the distance between the cap  46  and the cap support member  47  reaches the minimum and the lever  73  is positioned above the plate  61  of the lever  73 , as shown in  FIG. 10 . At this time, the lever  73  is moved leftward due to elastic restoration of the spring member  77  of the slide member  71 . 
   As the drive motor  38  is rotated further forward, the positioning member  79  slides in abutment on the fifth to seventh surfaces  91 ,  92  and  93  of the cam groove  86  of the cylindrical cam  35  shown in  FIG. 6  and abuts on the eighth surface  94 . Then, the teeth  85  of the upper end portion  83  of the cylindrical cam  35  moves to the position where it does not contact the third gear  109  (see  FIG. 3 ) and the rotation of the cylindrical cam  35  is stopped. 
   When the rotation of the cylindrical cam  35  is stopped and the drive motor  38  continues rotating further forward, the pump wheel  105  of the tube pump  37  starts the forward rotation. As shown in  FIG. 10 , therefore, the nozzles of the recording head  28  are covered with the cap  46  and with the valve seat  56  abutting on the plate  61 , the suction by the tube pump  37  is carried out. Then, the inside of the cap  46  is depressurized. 
   Then, inks as fluids in the ink cartridges  21  and  22  (see  FIG. 1 ), flow inside the cap  46  via the nozzles of the recording head  28 . Inks with increased viscosity in the vicinity of the nozzles, dust adhered to the nozzles, bubbles generated by replacement of the cartridges, or the like are exhausted to the outside via the ink tubes  53   a  and the cleaning operation is executed. 
   Thereafter, when the driving of the drive motor  38  is stopped and suction by the tube pump  37  is stopped, the inks are held inside the cap  46 . 
   In the case where printing starts again from the state shown in  FIG. 10 , the drive motor  38  is rotated reversely. Then, the drive force of the drive motor  38  is transmitted to the teeth  85  of the cylindrical cam  35  shown in  FIG. 6  via the first to third gears  107  to  109  (see  FIG. 3 ) and the cylindrical cam  35  is rotated in the direction opposite to the direction of the arrow in  FIG. 6 . 
   Then, the positioning member  79  moves in abutment on the seventh surface  93 , the ninth surface  95 , the tenth surface  96  and the eleventh surface  97  of the cylindrical cam  35  and moves downward to the position where it abuts on the twelfth and thirteenth surfaces  98  and  99 . Therefore, the cap support member  47  moves downward and the spring member  80  provided between the cap support member  47  and the cap  46  is elastically restored. As a result, as shown in  FIG. 11 , with the cap  46  abutting on the recording head  28 , the lever  73  of the cap support member  47  moves downward so that downward pressure is applied to the plate  61  of the cap  46  from the lever  73 . Consequently, the plate  61  is rotated clockwise in  FIG. 11  about the shaft  62   a  as the rotational center and the valve seat  56  is separated from the plate  61 . 
   Because the drive force of the drive motor  38  is not transmitted to the tube pump  37  at this timer the tube pump  37  is stopped with the roller  106  pressing against the ink tubes  53   a . Even if the valve seat  56  and the plate  61  are separated from each other to set the vent hole  54  open, therefore, the ink tubes  53   a  are pressed so that inks do not leak through the vent hole  54 . 
   The drive motor  38  is rotated forward again, the drive force of the drive motor  38  is transmitted to the teeth  85  of the cylindrical cam  35  via the first to third gears  107  to  109  and the cylindrical cam  35  is rotated in the direction of the arrow in  FIG. 6 . Then, the positioning member  79  slides in abutment on the twelfth and thirteenth surfaces  98  and  99  of the cylindrical cam  35  and abuts on the fourteenth surface  100 . Then, the teeth  85  of the cylindrical cam  35  moves to the position where it does not contact the third gear  109  (see  FIG. 3 ) and the rotation of the cylindrical cam  35  is stopped. 
   When the rotation of the cylindrical cam  35  is stopped, the rotation of the tube pump  37  is started. As shown in  FIG. 11 , therefore, the nozzles of the recording head  28  are covered with the cap  46  and with the valve seat  56  set apart from the plate  61 , the suction by the tube pump  37  is carried out. As a result, the inside the cap  46  is depressurized. 
   Then, air flows inside the cap  46  via the vent hole  54 . Then, the inks held inside the cap  46  are exhausted to the outside via the ink tubes  53   a  and so-called air suction is carried out. Consequently, the of the inside the cap  46  is filled with air. 
   When the driving of the drive motor  38  is stopped, suction by the tube pump  37  is stopped and then the drive motor  38  is rotated reversely, the drive force of the drive motor  38  is transmitted to the teeth  85  of the cylindrical cam  35  shown in  FIG. 6  via the first to third gears  107  to  109 , and the cylindrical cam  35  is rotated in the direction opposite to the arrow direction. 
   The positioning member  79  slides in abutment on the twelfth and thirteenth surfaces  98  and  99  and moves downward in abutment on the first and second surfaces  87  and  88 . Then, the cap support member  47  moves downward and the lever  73  moves downward outside the movable range of the plate  61 . As a result, the plate  61  rotates counterclockwise in  FIG. 11  about the shaft  62   a  due to elastic restoration of the spring member  58   a  and abuts on the valve seat  56 . 
   When the positioning member  79  moves down to the position where it contacts the lower end portion  84  of the cylindrical cam  35  shown in  FIG. 6 , the distance between the cap  46  and the cap support member  47  reaches maximum and the cap  46  parts from the recording head  28  as shown in  FIG. 7 . 
   At this time, the inks are not held inside the cap  46  because of air suction being performed, so that even if the recording apparatus  11  is placed in a state other than a horizontal state, the inks do not fall from the cap  46 . 
   The present embodiment has the following advantages. 
   With the driving of the drive motor  38 , the nozzles are covered with the cap  46 , making it possible to prevent the inks in the nozzles from becoming dried. Further, it is possible to change the distance between the cap  46  and the cap support member  47  by driving the drive motor  38  and selectively opening and closing the inside the cap  46  with respect to air. It is therefore possible to control both prevention of the inks in the nozzles from becoming dried and opening and closing of the inside of the cap  46  with respect to air by using the single drive motor  38 . As a result, the apparatus can be simplified. 
   With the cap  46  covering the nozzles, air suction can be performed by separating the plate  61  from the valve seat  56 , opening the inside of the cap  46  to air and driving the tube pump  37 . With this structure, even if the recording apparatus  11  is placed in a state other than a horizontal state, it is possible to make it difficult for the inks inside the cap  46  to leak to the outside. 
   The valve seat  56  is formed of a flexible material. Therefore, the plate  61  tightly contacts the valve seat  56  well, so that with the plate  61  abutting on the valve seat  56 , it is possible to prevent the inks from leaking or air from flowing in from the abutting portion. This can maintain the performance of the apparatus adequately. 
   When the distance between the cap support member  47  and the cap  46  is minimum (see  FIG. 10 ), the lever  73  is placed above the valve body  58  (plate  61 ). When the distance between the cap support member  47  and the cap  46  increases, the lever  73  contacts the plate  61  from above and presses the plate  61  downward. If the drive motor  38  is driven in the direction of reverse rotation with the cap  46  covering the nozzles, therefore, the distance between the cap support member  47  and the cap  46  increases, so that the plate  61  is pressed downward from above and parts from the valve seat  56 , setting inside the cap  46  open to air. It is possible to execute air suction by driving the tube pump  37  by driving the drive motor  38  in the forward rotation. 
   When the drive motor  38  is further driven in the direction of reverse rotation, the distance between the cap support member  47  and the cap  46  reaches maximum, making it possible to separate the cap  46  from the recording head  28 . That is, the inside of the cap  46  can be opened to air at the suitable timing for air suction, which is immediately before separation of the cap  46  from the recording head  28 . 
   The spring member  58   a  urges the plate  61  in a direction to abut on the valve seat  56 . When downward force is applied to the plate  61  from above, therefore, the plate  61  is set apart from the valve seat  56 , opening the inside of the cap  46  to air, but the vent hole  54  is closed by the urging force of the spring member  58   a  otherwise. That is, only when air suction is performed, downward force is applied to the plate  61  from above to set the inside of the cap  46  open to air, and the plate  61  can be made to abut on the valve seat  56  otherwise. At times than other during the air suction, therefore, the vent hole  54  can be closed by abutting the plate  61  on the valve seat  56 , thereby making it possible to prevent the inks from leaking to the outside as a result of the vent hole  54  being opened. 
   The plate  61  is rotatable with respect to the cap  46  and the lever  73  is placed outside the movable range of the plate  61  when the distance between the cap support member  47  and the cap  46  is maximum. Even if the plate  61  is separated from the valve seat  56  pressed downward by the lever  73 , when the distance between the cap  46  and the cap support member  47  reaches maximum, the lever  73  is placed outside the movable range of the plate  61 , so that the plate  61  is not pressed by the lever  73 . As a result, the plate  61  moves upward due to the urging force of the spring member  58   a  and abuts on the valve seat  56 . When the distance between the cap  46  and the cap support member  47  reaches maximum, i.e., when the cap  46  is separated from the nozzles of the recording head  28 , therefore, the vent hole  54  is closed. For example, leakage of the inks from the vent hole  54  can be prevented at the time of performing the flashing (reserve ejection) operation to prevent clogging or the like of the openings of the nozzles by discharging the inks by application of a drive signal irrelevant to printing by the recording head  28 . 
   The inclined surfaces  61   a  and  73   a  inclined in the movement direction of the cap support member  47  are respectively formed on the lower surface of the plate  61  and the top surface of the lever  73 . When the lever  73  pushes the plate  61  in such a direction that the plate  61  abuts on the valve seat  56 , therefore, the pressing force of the lever  73  is converted to a force to slide the lever  73  itself. It is therefore unnecessary to separately provide a drive mechanism to slide the lever  73 , making it possible to simplify the structure of the apparatus. 
   The lever  73  is provided with the urging member to urge the lever  73  itself in the slide direction. Even if the lever  73  is slid to avoid the plate  61  when the lever  73  is moved upward, it is returned to the original position by the urging member. This can simplify the drive mechanism for sliding the lever  73  and can simplify the structure of the apparatus. 
   The drive force of the drive motor  38  is transmitted to the cap support member  47  via the cylindrical cam  35  to move the cap support member  47  up and down. Based on the shape of the cylindrical cam  35 , therefore, the up/down position of the cap support member  47  can be finely changed. And, it is possible to easily execute control to selectively open and close the inside of the cap  46  with respect to air while covering the nozzles with the cap  46  or to separate the cap  46  from the nozzles. 
   The drive force from the drive motor  38  is transmitted to the cylindrical cam  35 , which moves the cap support member  47  up and down, and the tube pump  37  with a predetermined phase difference. Therefore, the up and down movement of the cap support member  47  and the driving of the tube pump  37  can be accomplished by a single drive motor  38 . This results in elimination of the need to provide a plurality of drive motors  38  in order to prevent the inks in the nozzles from becoming dried and executing air suction, thus making it possible to simplify the structure of the apparatus. 
   A second embodiment embodying the present invention will be described below with reference to  FIGS. 12 to 15 . As compared with the embodiment in  FIGS. 1 to 11 , members including the valve body  58 , the support rod  72  and the lever  73  are omitted and an air release means different from that of the embodiment in  FIGS. 1 to 11  is provided in this embodiment. In this embodiment, those items which differ from the embodiment in  FIGS. 1 to 11  are described and the same symbols are given to similar portions and their descriptions are omitted.  FIGS. 12 to 15  are side views of the cap apparatus  32  according to this embodiment as seen from the third retaining portion  43  (see  FIG. 3 ). 
   The cap apparatus  32  has a cap  120  and a cap support member  121  coupled to the cap  120 , as shown in  FIG. 12 . The cap support member  121  is supported at the first retaining portion  41  in  FIG. 3  in such a way as to be slidable in the up and down direction. 
   The cap  120 , like the cap  46  in  FIG. 2 , is a box with the top side open, and is retained inside the cap support member  121  which is formed in an approximately rectangular frame. The opening of the cap  120  has such a size as to be able to cover the nozzles of the recording head  28 . The close-contact portion  51  is provided at the periphery of the opening of the cap  120 . 
   The exhaust ports  53  provided in the bottom of the cap  120  are connected to the ink tubes  53   a  and the inks remaining in the cap  120  are exhausted via the ink tubes  53   a.    
   The vent hole  54  as a through hole is formed in the bottom of the cap  120  (see  FIG. 5 ). The proximal end of an air tube  122  is connected to the vent hole  54  and the distal end of the air tube  122  is led around from below the cap  120  and is supported from the inside of the cap support member  121  to the outer side surface (the third retaining portion  43  side) via a hole portion  121   a . Further, a valve seat  123  is provided integral with the distal end of the air tube  122 . The air tube  122  and the valve seat  123  are formed of a flexible material, for example, an elastomer. 
   The vent hole  54  permits exhaustion of inks remaining in the cap  120  and permits flow of air into the cap  120  via the air tube  122  at the time of air suction to evacuate inside the cap  120 . As air is taken into the vent hole  54  via the air tube  122 , it is possible to prevent inks from leaking from the vent hole  54 . 
   As shown in  FIG. 12 , a shaft  124  is protrusively provided on the outer side surface of the cap support member  121 . A valve body  126  is rotatably attached to the shaft  124 . A first spring member  125  which is, for example, a torsion coil spring, is attached to the valve body  126 . The valve body  126  includes an annular-shaped support portion  127  and an extension plate  128  extending from the support portion  127 . A projection  129  is formed at the periphery of the support portion  127  at a position opposite to the extension plate  128 . 
   As the valve body  126  rotates counterclockwise in  FIG. 12 , a side  128   a  of the extension plate  128  abuts on the valve seat  123  of the air tube  122 . Accordingly, the vent hole  54  is sealed via the air tube  122 . As the valve body  126  rotates clockwise in  FIG. 12 , the side  128   a  of the extension plate  128  parts from the valve seat  123  of the air tube  122 . Accordingly, air flows into the cap  120  passing through the air tube  122  and the vent hole  54 . 
   The valve body  126  is normally urged in the counterclockwise direction by the first spring member  125 . In the case where no external force is applied to the valve body  126 , therefore, the side  128   a  of the extension plate  128  always abuts on the valve seat  123 , sealing the vent hole  54 . Further, in a case the where leftward force is applied to the projection  129  from the right side in  FIG. 12 , the extension plate  128  rotates clockwise about the shaft  124  against the elastic force of the first spring member  125  and parts from the valve seat  123 . As a result, air flows into the cap  120  passing through the air tube  122  and the vent hole  54 . 
   The cap  120  is connected to the cap support member  121  via a second spring member  130 . The second spring member  130  urges the cap  120  in a direction to separate the cap  120  and the cap support member  121  from each other in the up and down direction. 
   As shown in  FIG. 12 , the cap  120  has a stop portion  131  extending upward of the cap  120 . The cap support member  121  has an engage portion  132  which is open toward the end portion of the cap support member  121  and has a trapezoidal cross section. As the stop portion  131  of the cap  120  engages with the engage portion  132  of the cap support member  121 , an increase in the distance between the cap  120  and the cap support member  121  is restricted. 
   As shown in  FIG. 13 , a partition  133  is provided on a bottom  41   a  of the first retaining portion  41  (see  FIG. 3 ). The partition  133  is arranged between the cap support member  121  and the third retaining portion  43  (see  FIG. 3 ). 
   An abutment portion  134  as a pressing member is formed on the partition  133  at a position facing the valve body  126 . In accordance with the up/down movement of the cap support member  121 , the abutment portion  134  selectively abuts on or parts from the projection  129  of the valve body  126 . 
   When the projection  129  abuts on the abutment portion  134 , the projection  129  is pressed leftward from the right side in  FIG. 12  by the abutment portion  134 . Accordingly, the valve body  126  rotates clockwise about the shaft  124 . As a result, the extension plate  128  of the valve body  126  is separated from the valve seat  123 , releasing the inside of the cap  120  to air. 
   With the cap support member  121  moves to the topmost position as shown in  FIG. 14 , the abutment portion  134  is placed under the projection  129 . In the case where no external force is applied to the cap support member  121 , with the cap support member  121  moved to the lowermost position as shown in  FIG. 13 , on the other hand, the abutment portion  134  is placed above the projection  129 . 
   The action of the nozzle protecting device  30  with the above-described structure will be described based on  FIGS. 13 to 15 . 
   First, when a process of carrying out a cleaning operation and flashing operation is executed in the recording apparatus  11 , the carriage  16  is moved to the home position of the frame  12  as in the embodiment in  FIGS. 1 to 11 . Then, as shown in  FIG. 13 , the recording head  28  of the carriage  16  faces the cap  120  of the nozzle protecting device  30 . In this state, the positioning member  79  of the cap support member  121  is engaged with the cam groove  86  of the cylindrical cam  35  shown in  FIG. 6  at the lowest position; specifically, it abuts on the first surface  87  and the second surface  88  of the cam groove  86 . 
   In  FIG. 13 , the distance between the cap  120  and the cap support member  121  is maximum, and the distance between the cap support member  121  and the partition  133  is minimum. The abutment portion  134  of the partition  133  is positioned above the projection  129  of the valve body  126 . The extension plate  128  of the valve body  126  abuts on the valve seat  123  so that the vent hole  54  is closed via the air tube  122 . In this state, even when the flashing operation is performed and the inks are ejected inside the cap  120 , the inks do not leak from the vent hole  54 . 
   In the case where the cleaning operation is performed, on the other hand, the positioning member  79  of the cap support member  121  moves upward while abutting on the second and third surfaces  88  and  89  of the cam groove  86  (see  FIG. 6 ). 
   Then, with the upward movement of the positioning member  79 , the cap support member  121  moves upward and the close-contact portion  51  of the cap  120  abuts on the recording head  28 , covering the recording head  28 . The recording head  28  restricts the upward movement of the cap  120  and elastically deforms the spring member  130  provided between the cap  120  and the cap support member  121 , thereby decreasing the distance between the cap  120  and the cap support member  121 . 
   At this time, the projection  129  moves upward of the abutment portion  134  of the partition  133  in accordance with the upward movement of the cap support member  121 . Consequently, when a predetermined time elapses, the projection  129  of the valve body  126  abuts on the abutment portion  134  of the partition  133 , causing air to flow into the cap  120 . Thereafter, the projection  129  moves upward of the abutment portion  134  and parts from the abutment portion  134 . 
   Subsequently, the distance between the cap  120  and the cap support member  121  reaches a minimum and the projection  129  is positioned above the abutment portion  134 , as shown in  FIG. 14 . At this time, the extension plate  128  of the valve body  126  abuts on the valve seat  123  due to the elastic restoration of the spring member  125  and the vent hole  54  is closed via the air tube  122 . 
   Thereafter, the rotation of the cylindrical cam  35  is stopped and as shown in  FIG. 14 , the nozzles of the recording head  28  are covered with the cap  120  and suction by the tube pump  37  is carried out with the extension plate  128  abutting on the valve seat  123 . When the inside of the cap  120  is depressurized, inks in the ink cartridges  21  and  22  (see  FIG. 1 ) flow inside the cap  120  via the nozzles of the recording head  28 . Then, inks with increased viscosity in the vicinity of the nozzles, dust adhered to the nozzles, bubbles generated by replacement of the cartridges, or the like are exhausted to the outside via the ink tubes  53   a  and the cleaning operation is executed. 
   Thereafter, when suction by the tube pump  37  is stopped, the inks are retained inside the cap  120 . 
   Subsequently, in the case where printing starts again from the state shown in  FIG. 14 , the cap support member  121  is lowered according to the operation of the cylindrical cam  35  as described in the embodiment in  FIGS. 1 to 11 . Then, the spring member  130  provided between the cap support member  121  and the cap  120  is elastically restored. 
   As a result, as shown in  FIG. 15 , with the cap  120  abutting on the recording head  28 , the projection  129  of the valve body  126  moves downward and abuts on the abutment portion  134 . Leftward force is applied to the projection  129  from the right side in the diagram by the abutment portion  134 . Consequently, the valve body  126  is rotated clockwise in  FIG. 15  about the shaft  124  as the rotational center and the valve seat  123  is separated from the extension plate  128  and air flows inside the cap  120 . 
   The tube pump  37  is stopped with the roller  106  pressing against the ink tubes  53   a  as per the embodiment in  FIGS. 1 to 11 . Even if the extension plate  128  is separated from the valve seat  123  to set the vent hole  54  open via the air tube  122 , therefore, the ink tubes  53   a  are pressed so that inks do not leak through the vent hole  54 . 
   Thereafter, as shown in  FIG. 15 , suction by the tube pump  37  is carried out with the extension plate  128  separated from the valve seat  123 . And, the inside of the cap  120  is depressurized. Then, air flows inside the cap  120  via the air tube  122  and the vent hole  54 . Subsequently, the inks held inside the cap  120  are exhausted to the outside via the ink tubes  53   a  and so-called air suction is performed. As a result, the inside of the cap  120  is filled with air. 
   Thereafter, after suction by the tube pump  37  is stopped, the cap support member  121  is lowered according to the operation of the cylindrical cam as per the embodiment in  FIGS. 1 to 11 . Consequently, the projection  129  moves upward relative to the partition  133  and the extension plate  128  rotates counterclockwise about the shaft  124  in  FIG. 12  due to the elastic restoration of the spring member  125  and abuts on the valve seat  123 . When the distance between the cap  120  and the cap support member  121  reaches maximum, the cap  120  is separated from the recording head  28  as shown in  FIG. 13 . The abutment portion  134  is positioned above the projection  129  and outside the movable range of the projection  129  and is separated from the projection  129 . 
   At this time, air suction is performed and the inks are not held inside the cap  120 , so that even if the recording apparatus  11  is set in a state other than a horizontal state, the inks do not leak from inside the cap  120 . 
   A third embodiment embodying the present invention will be described below with reference to  FIGS. 16 to 23 . It should be noted that the same symbols are given to similar portions to those of the recording apparatus  11  in  FIG. 1  and their descriptions are omitted. 
   As shown in  FIG. 16 , a cylindrical cam  234  is supported inside a retaining portion Kd of the case  31  by a support portion Ke protruding at the center thereof. The cylindrical cam  234  is rotatable about the rotational axial center C of the support portion Ke. A driven gear  242  is provided above the cylindrical cam  234 . The driven gear  242  is a spur gear having a plurality of teeth  242   a  formed around the entire circumferential surface at predetermined pitches a. The driven gear  242  rotates always in engagement with teeth  110   a  of the fourth gear  110 . A compression spring  250  is provided between the driven gear  242  and the lid  44 . One end portion of the compression spring  250  is pressed against the lid  44  and the other end portion is pressed against the driven gear  242 , thus pressing the driven gear  242  downward toward the cylindrical cam  234 . Therefore, the torque from the driven gear  242  is transmitted to the cylindrical cam  234  by friction. 
   A partially toothed gear  251  having a ring shape is provided at the upper end portion of the cylindrical cam  234  between the cylindrical cam  234  and the driven gear  242 . A plurality of teeth  251   a  are formed on about one-half of the circumferential surface of the partially toothed gear  251 . The plural teeth  251   a  are formed at the same pitches a as the driven gear  242  and engage with the teeth  110   a  of the fourth gear  110 . The upper sides of the teeth  110   a  of the fourth gear  110  engage with the teeth  242   a  of the driven gear  242  and the lower sides engage with the teeth  251   a  of the partially toothed gear  251  at the same time. 
   A cam groove  252  is formed in the circumferential surface of the cylindrical cam  234 . As shown in  FIG. 22 , the cam groove  252  includes a first guide portion  252   a  extending along the circumferential direction at the lower portion of the cam groove  252 , a second guide portion  252   b  extending obliquely upward from the first guide portion  252   a  and a third guide portion  252   c  extending in parallel along the circumferential direction from the second guide portion  252   b . As shown in  FIG. 20(   a ) to  FIG. 21 , a rotation restriction groove  253  having a center angle of about 200° and an arcuate shape is formed in the bottom of the cylindrical cam  234 . The angle defined by lines connecting first and second end portions  253   a  and  253   b  of the rotation restriction groove  253  to the rotational axial center C of the support portion Ke is greater than 180 degrees. A stop member  254  is slidably engaged with the rotation restriction groove  253 . The stop member  254  is fixed to the bottom of the retaining portion Kd of the case  31 . When the cylindrical cam  234  rotates, therefore, the stop member  254  abuts on both end portions  253   a  and  253   b  of the rotation restriction groove  253  (see  FIG. 20(   a ) to  FIG. 21) , thus restricting the rotation of the cylindrical cam  234 . 
   Next, the structures of the cylindrical cam  234  and the driven gear  242  coaxial to the cylindrical cam  234  are described in detail based on  FIGS. 22 and 23 . The cylindrical cam  234  includes a first groove-forming member  255 , a second groove-forming member  256  and the partially toothed gear  251 . The first groove-forming member  255  and the second groove-forming member  256  are equivalent to the rotary member. 
   The first groove-forming member  255  has a disk-shaped base portion  255   a . The rotation restriction groove  253  is formed at the bottom of the base portion  255   a . A wall portion  255   b  extends upward from the top of the base portion  255   a . The wall portion  255   b  has a cylindrical shape with a part cut away. A cutaway portion  257  is formed in the wall portion  255   b  positioned above the first end portion  253   a  of the rotation restriction groove  253 . The cutaway portion  257  extends obliquely upward from the top of the base portion  255   a . A first step portion  32  extending toward the driven gear  242  (see  FIG. 20(   b )) is formed at the wall portion  255   b  positioned above the second end portion  253   b  of the rotation restriction groove  253 . 
   As shown in  FIG. 23 , a cylinder portion  255   c  apart from the wall portion  255   b  by a predetermined distance and concentric thereto is formed at the center of the first groove-forming member  255 . A through hole h is formed in the center of the cylinder portion  255   c  and the support portion Ke of the case  31  penetrates through the through hole h. 
   The second groove-forming member  256  has a cylinder portion  256   a . The cylinder portion  256   a  is fitted in the gap between the wall portion  255   b  of the first groove-forming member  255  and the cylinder portion  255   c . A ring portion  256   b  shorter in the axial direction than the cylinder portion  256   a  is integrally formed on the circumferential surface of cylinder portion  256   a . An extension portion  258  is provided at a part of the ring portion  256   b . The axial length of the extension portion  258  is shorter than the axial length of the cylinder portion  256   a . The extension portion  258  has an inclined portion having the same inclination angle as the inclined portion of the cutaway portion  257 . The inclined portion of the extension portion  258  is inserted into the cutaway portion  257  of the first groove-forming member  255 . Further, a second step portion S 1  (see  FIG. 6(   b )) is formed at a part of the circumferential surface of the ring portion  256   b.    
   When the cylinder portion  256   a  of the second groove-forming member  256  is inserted into the gap between the wall portion  255   b  of the first groove-forming member  255  and the cylinder portion  255   c , therefore the first groove-forming member  255  is disabled to rotate with respect to the second groove-forming member  256 . When the extension portion  256  of the second groove-forming member  256  is inserted into the cutaway portion  257  of the first groove-forming member  255 , a gap is formed between the extension portion  258  and the base portion  255   a . This gap is equivalent to the first guide portion  252   a . A gap is also formed between the inclined portion of the cutaway portion  257  and the inclined portion of the second groove-forming member  256 . This gap is equivalent to the second guide portion  252   b . As shown in  FIG. 20(   b ), the step portion S 2  of the first groove-forming member  255  becomes level with the step portion S 1  of the second groove-forming member  256 , forming an end wall portion for the third guide portion  252   c . That is, as the first groove-forming member  255  is attached to the second groove-forming member  256 , the cam groove  252  is defined and formed. The rotation restriction groove  253  is formed in an angular range approximately the same as the angle at which the cam groove  252  is defined and formed. According to this embodiment, therefore, the cylindrical cam  234  is rotatable only in the angular range. 
   A pair of recess portions  259  are provided at the upper end portion of the ring portion  256   b  of the second groove-forming member  256 . Further, a ring-shaped groove  256   c  formed at the upper end of the second groove-forming member  256 , radially inward of the positions of both recess portions  259  and radially outward of the cylinder portion  256   a.    
   As shown in  FIG. 21 , the tooth  251   a  in the plural teeth  251   a  which is positioned at an end portion E is provided at a position where it nearly faces the fourth gear  110  when the stop member  254  abuts on the first end portion  253   a  of the rotation restriction groove  253 , i.e., when the cleaning operation is initiated. At the same time as the fourth gear  110  rotates in the direction r 1 , the partially toothed gear  251  engaged with the fourth gear  110  rotates in the direction r 2 . 
   As shown in  FIG. 22 , a pair of projection portions  260  protruding downward are provided on the partially toothed gear  251  at positions facing each other. The individual projection portions  260  are engaged with the respective recess portions  259  of the second groove-forming member  256 . Specifically, when the projection portions  260  are engaged with the respective recess portions  259 , a gap equivalent to a half of one pitch a of the tooth  251   a  is formed between the circumferential surface of the projection portion  260  extending in the axial direction and the wall of the recess portion  259  which faces that circumferential surface and extends in the axial direction. That is, the partially toothed gear  251  can turn by the pitch a of the tooth  251   a  with respect to the second groove-forming member  256 . 
   As shown in  FIG. 23 , a cylinder portion  242   b  is formed at the center portion of the driven gear  242  in such a way as to extend along the axial direction. The compression spring  250  (see  FIG. 16 ) is fitted over the upper end portion of the cylinder portion  242   b . The lower end portion of the cylinder portion  242   b  is fitted in the ring-shaped groove  256   c  of the second groove-forming member  256 . A large-diameter portion  242   c  is provided between the driven gear  242  and the cylinder portion  242   b . The large-diameter portion  242   c  is fitted in the inner hole of the partially toothed gear  251 . Therefore, the driven gear  242  is rotatable with respect to the cylindrical cam  234  and rotates about the rotational axial center C of the cylindrical cam  234 . 
   As shown in  FIGS. 17 to 19 , the nozzle protecting device  30  has a wiping apparatus  235 . The wiping apparatus  235  has a wiper support member  261  provided along the direction of the arrow y. The wiper support member  261  is supported on the case  31  in such a way as to be movable in the up and down direction of the case  31  and to be unmovable in the direction of the arrow y. A holding member  262  is formed extending from the lower portion of the side of the wiper support member  261  concerning the direction of the arrow y, as shown in  FIGS. 16 ,  19 ,  20 ( a ) and  20 ( b ). As shown in  FIGS. 20(   a ) and  20 ( b ), a positioning member  262   a  is formed extending from the distal end of the holding member  262  in the direction of the arrow x. The positioning member  262   a  is slidably fitted in the cam groove  252  of the cylindrical cam  234 . 
   As the cylindrical cam  234  is rotated by the drive motor  38 , the holding member  262  is moved up and down by the positioning member  262   a  which slides in the guide portions  252   a ,  252   b  and  252   c  of the cam groove  252 . That is, when the positioning member  262   a  slides in the first guide portion  252   a , the positioning member  262   a  is guided to a position of non-action. When the positioning member  262   a  slides in the third guide portion  252   c , the holding member  262  is guided to a position of action. Further, when the positioning member  262   a  slides in the second guide portion  252   b , the holding member  262  is guided to a position between the position of non-action and the position of action. 
   Specifically, as shown in  FIGS. 16 ,  19  and  20 ( a ), when the stop member  254  abuts on the first end portion  253   a  of the rotation restriction groove  253  of the first groove-forming member  255 , the fourth gear  110  faces the tooth  251   a  at the end portion E of the partially toothed gear  251  and the positioning member  262   a  is positioned at the position where it abuts on the end wall of the first guide portion  252   a  of the cam groove  252 . In this state, therefore, the holding member  262  is positioned at the position of non-action. As the fourth gear  110  is rotated in the direction r 1  from this state, the driven gear  242  and the partially toothed gear  251  rotate in the direction r 2 . Their rotation causes the cam groove  252  of the cylindrical cam  234  to rotate and the positioning member  262   a  slides to contact the third guide portion  252   c  from the first guide portion  252   a  of the cam groove  252  through the second guide portion  252   b . With the movement of the positioning member  262   a , the wiper support member  261  moves upward and reaches the position of action when the positioning member  262   a  slides to contact the third guide portion  252   c . When the stop member  254  abuts on the first end portion  253   b  of the rotation restriction groove  253  by the rotation of the cylindrical cam  234 , as shown in  FIG. 20(   b ), the positioning member  262   a  abuts on the end wall (step portions S 1 , S 2 ) of the third guide portion  252   c  of the cam groove  252 . As the positioning member  262   a  moves to the third guide portion  252   c  from the first guide portion  252   a  of the cam groove  252  through the second guide portion  252   b , the partially toothed gear  251  engages with the fourth gear  110  but the partially toothed gear  251  does not engage with the fourth gear  110  before the positioning member  262   a  reaches the end wall of the third guide portion  252   c.    
   As the drive motor  38  is rotated reversely from the state shown in  FIG. 20(   b ) to the state shown in  FIG. 20(   a ), the positioning member  262   a  slides to contact the first guide portion  252   a  from the third guide portion  252   c  through the second guide portion  252   b  in the reverse order to the previously described order. As a result, the wiper support member  261  is lowered to the position of non-action from the position of action. 
   A wiping member  263  extending in the direction of the arrow y is fixed to the top of the wiper support member  261 . The wiping member  263  is formed of an elastic material, such as rubber. A distal end  263   a  of the wiping member  263  is bent in the direction of the arrow x and cleans in such a way as to wipe off the inks adhered to the recording head  28 . That is, when the wiper support member  261  moves upward to the position of action, the distal end  263   a  of the wiping member  263  is pressed against the recording head  28 , which passes above, from below and wipes off inks adhered to the recording head  28 . 
   The action of the recording apparatus  11  according to this embodiment will be described using  FIGS. 16 to 20(   b ) and  FIG. 1 . 
   In the case where printing is finished and the cleaning operation of the recording head  28  is to be carried out, the recording apparatus  11  drives the carriage motor  18  to move the carriage  16  in the direction of the arrow x to the position where the carriage  16  faces the cap  46 . At this time, the positioning member  262   a  of the wiper support member  261  is positioned at the first guide portion  252   a  of the cam groove  252 , as shown in  FIGS. 16 ,  19  and  20 ( b ). Accordingly, even when the carriage  16  passes over the wiping member  263  in the direction x, the distal end  263   a  of the wiping member  263  does not abut on the recording head  28  of the carriage  16 . The tooth  251   a  at the end portion E of the partially toothed gear  251  faces the fourth gear  110 . Further, the stop member  254  abuts on the first end portion  253   a  of the rotation restriction groove  253 . 
   When the carriage  16  arrives at the position facing the cap  46 , the recording apparatus  11  stops driving the carriage motor  18  and rotates the drive motor  38  forward. When the drive motor  38  is rotated forward, the drive gear  38   a  is rotated and its torque is transmitted to the fourth gear  110  via the individual first to third gears  107  to  109 . The fourth gear  110  is rotated in the direction r 1  and the driven gear  242  which engages with the fourth gear  110  is rotated in the direction r 2 . When the driven gear  242  starts rotating in the direction r 2 , the driven gear  242  is pressed downward and the driven gear  242  slides to contact the partially toothed gear  251 , so that the torque of the driven gear  242  is transmitted to the partially toothed gear  251  by frictional force so that the partially toothed gear  251  tries to rotate. Further, as the teeth  251   a  of the partially toothed gear  251  are at the position facing the fourth gear  110 , the teeth  251   a  of the partially toothed gear  251  engage with the fourth gear  110 . 
   As a result, upon reception of the torque from the fourth gear  110 , the partially toothed gear  251  is rotated in the direction r 2 . As the partially toothed gear  251  rotates, the partially toothed gear  251  rotates with respect to the second groove-forming member  256  until its projection portion  260  abuts on the wall of the recess portion  259  in the direction r 2 , then rotates together with the first groove-forming member  255  and the second groove-forming member  256 . That is, the cylindrical cam  234  is rotated in the direction r 2  and the cam groove  252  rotates. Accordingly, the positioning member  262   a  of the wiper support member  261  reaches the third guide portion  252   c  through the second guide portion  252   h  from the first guide portion  252   a  of the cam groove  252  where it has been fitted, causing the wiping member  263  to move upward. 
   As the positioning member  262   a  reaches the third guide portion  252   c  and the cylindrical cam  234  makes about a half turn, the teeth  251   a  of the partially toothed gear  251  do not engage with the fourth gear  110 . As the driven gear  242  which slides to contact the partially toothed gear  251  keeps rotating, the torque of the driven gear  242  is converted to frictional force and is transmitted to the partially toothed gear  251 , causing the cylindrical cam  234  to further rotate. And, when the stop member  254  abuts on the end portion  253   b  of the rotation restriction groove  253  of the cylindrical cam  234 , as shown in  FIG. 20(   b ), the rotation of the cylindrical cam  234  in the direction r 2  is stopped. 
   The cap support member  47  is moved upward by the elevation mechanism, which is driven by torque transmitted from the driven gear  242 , and the cap  46  guided is to the position of action and tightly contacts the recording head  28 . Then, a tube pump  233  is driven via the third gear  109 , generating negative pressure in the tightly closed space of the recording head  28 . Accordingly, inks with high viscosity, which cause clogging in the nozzles of the recording head  28 , are exhausted to the waste liquid tank  40 . 
   When the drive motor  38  is switched to the reverse rotation thereafter, the fourth gear  110  rotates in the direction opposite to the direction r 1 . This causes the driven gear  242  to rotate in the direction opposite to the direction r 2 . The torque of the driven gear  242  is converted to frictional force which is transmitted to the partially toothed gear  251  so that the partially toothed gear  251  rotates in the direction opposite to the direction r 2  in a state where it does not engage with the fourth gear  110 . At this time, the partially toothed gear  251  rotates until the projection portion  260  abuts on the wall of the recess portion  259  in the direction opposite to the direction r 2 , and then rotates together with the first groove-forming member  255  and the second groove-forming member  256 . That is, the cylindrical cam  234  rotates in the direction opposite to the direction r 2 . 
   With the positioning member  262   a  of the holding member  262  positioned in the third guide portion  252   c  and the wiping member  263  being at the position of action, the drive motor  38  is stopped. At this time, the cap support member  47  is lowered by the elevation mechanism and the cap  46  is positioned at the position of non-action so that the carriage  16  becomes movable. Then, the recording apparatus  11  drives the carriage motor  18  to move the carriage  16  in the direction opposite to the direction of the arrow x from above the cap  46 . Then, the carriage  16  abuts on the wiping member  263  and moves in the direction opposite to the direction of the arrow x so that the wiping member  263  is bent by the carriage  16 , which moves, and then its distal end  263   a  abuts on the recording head  28 . As the carriage  16  further moves in the direction of the arrow x, the wiping member  263  moves with respect to the recording head  28  and performs cleaning in such a way as to wipe the entire surface of the recording head  28 . 
   When the recording head  28  passes over the wiping member  263  and cleaning of the recording head  28  by the wiping member  263  is finished in this way, the recording apparatus  11  rotates the drive motor  38  reversely again. Therefore, the fourth gear  110  rotates again in the direction opposite to the direction r 1  and the driven gear  242  engaging with the fourth gear  110  rotates in the direction opposite to the direction r 2  so that upon reception of the torque from the driven gear  242 , the partially toothed gear  251  rotates in the direction opposite to the direction r 2 . The teeth  251   a  of the partially toothed gear  251  rotate to the position facing the fourth gear  110  to try to engage with the fourth gear  110 . 
   In the case where the teeth  242   a  of the driven gear  242  are not aligned with the teeth  251   a  of the partially toothed gear  251  at this time, i.e., in the case where the teeth  251   a  of the partially toothed gear  251  do not smoothly engage with the teeth  110   a  of the fourth gear  110 , the teeth  251   a  of the partially toothed gear  251  are filliped by the torque of the teeth  110   a  of the fourth gear  110 . At this time, the load of the partially toothed gear  251  is applied to the partially toothed gear  251  and the fourth gear  110 . There is a gap between the projection portion  260  of the partially toothed gear  251  and the recess portion  259  of the second groove-forming member  256  and the large-diameter portion  242   c  of the driven gear  242  is fitted in the partially toothed gear  251 . Accordingly, even when the second groove-forming member  256  under the partially toothed gear  251  and the driven gear  242  above the partially toothed gear  251  are rotating, the partially toothed gear  251  alone stops temporarily. That is, the partially toothed gear  51  rotates in the direction r 1  with respect to the driven gear  242 , which is rotating in the direction opposite to the direction r 1  always in engagement with the fourth gear  110 , and the second groove-forming member  256  which rotates due to inertial force. 
   Accordingly, only the partially toothed gear  251  stops temporarily and is so adjusted to smoothly engage with the teeth  110   a  of the fourth gear  110 . When the partially toothed gear  251  is aligned with the teeth  242   a  of the driven gear  242 , it smoothly engages with the fourth gear  110 . Accordingly, the partially toothed gear  251  receives the torque from the fourth gear  110  via the tooth  251   a  and the torque of the driven gear  242  positioned above and rotates in the direction opposite to the direction r 1 . As the cylindrical cam  234  rotates with the rotation of the partially toothed gear  251 , the positioning member  262   a  fitted in the third guide portion  252   c  of the cam groove  252  moves along the second guide portion  252   b  of the cam groove  252  and is guided to the first guide portion  252   a . Therefore, the wiping member  263  of the wiping apparatus  235  moves downward and the positioning member  262   a  reaches the first guide portion  252   a  of the cam groove  252  as shown in  FIGS. 16 ,  19 ,  20 ( a ) and  21 . The stop member  254  abuts on the first end portion  253   a  of the rotation restriction groove  253 , restricting the rotation of the cylindrical cam  234 , so that the cylindrical cam  234  stops rotating in the direction opposite to the direction r 1 . Thereafter, the rotation of the drive motor  38  is stopped. 
   The present embodiment has the following advantages. 
   When the positioning member  262   a  moves to the third guide portion  252   c  from the first guide portion  252   a  through the second guide portion  252   b  or moves to the first guide portion  252   a  from the third guide portion  252   c  through the second guide portion  252   b , the partially toothed gear  251  engages with the fourth gear  110  and receives drive force. Even if inks are adhered to the partially toothed gear, increasing the load, therefore, the positioning member  262   a  reliably receives the torque from the fourth gear  110  when moving to the second guide portion  252   b . It is therefore possible to reliably rotate the cylindrical cam  234  and ensure the elevation of the wiping member  263 . 
   The driven gear  242  provided above the partially toothed gear  251  is pressed toward the partially toothed gear  251  by the compression spring  250 , so that the torque of the driven gear  242  is converted to frictional force and is transmitted to the partially toothed gear  251  by the frictional force. Therefore, when the partially toothed gear  251 , even disengaged from the fourth gear  110 , is rotated reversely, the cylindrical cam  234  is rotated upon reception of rotation force from the driven gear  242  and the partially toothed gear  251  tries to engage with the fourth gear  110 . At this time, the cylindrical cam  234  keeps receiving the torque of the driven gear  242 , so that when the partially toothed gear  251  does not smoothly engage with the fourth gear  110 , the partially toothed gear  251  stops regardless of the rotation of the second groove-forming member, which rotates upon reception of frictional force from the driven gear  242 . That is, as the partially toothed gear  251  rotates with respect to the second groove-forming member  256 , the partially toothed gear  251  can smoothly engage with the fourth gear  110  with a small load. 
   The partially toothed gear  251  can turn by a gap (by one pitch a) between the recess portion  259  and the projection portion  260  with respect to the second groove-forming member  256 . With the partially toothed gear  251  not in smooth engagement with the fourth gear  110 , therefore, the partially toothed gear  251  is filliped in accordance with the rotation of the fourth gear  110  and the partially toothed gear  251  moves with respect to the other members (first and second groove-forming members  255  and  256 ) of the cylindrical cam  234 . Accordingly, the drive motor  38  is stopped regardless of the movements of the first groove-forming member  255  and the second groove-forming member  256  and the position of the teeth  251   a  of the partially toothed gear  251  is adjusted in such a way that the partially toothed gear  251  engages with the fourth gear  110  by the torque from the fourth gear  110 . At this time, the load of the partially toothed gear  251  alone, not the entire load of the cylindrical cam  234 , is applied to the fourth gear  110 . Therefore, the partially toothed gear  251  can be smoothly engaged with the fourth gear  110  with a small load. As the partially toothed gear  251  engages with the fourth gear  110  smoothly without a large load applied to the partially toothed gear  251 , therefore, the partially toothed gear  251  can have an extended life. 
   As shown in  FIG. 23 , the ring-like partially toothed gear  251  becomes lighter as compared with a gear having, for example, a disk shape. It is therefore possible to make the load from the engagement of the partially toothed gear  251  with the fourth gear  110  smaller. The partially toothed gear  251  can thus be engaged with the fourth gear  110  smoothly and can be made to have a longer life. 
   The partially toothed gear  251  is rotatable with respect to the driven gear  242 . When the position of the tooth  251   a  is adjusted to engage the partially toothed gear  251  with the fourth gear  110 , therefore, the partially toothed gear  251  can be stopped irrespective of the rotational state of the driven gear  242 . Thus, the load at the time the partially toothed gear  251  engages with the fourth gear  110  can be reduced. 
   As shown in  FIG. 22 , the gap between the projection portion  260  and the recess portion  259  is set to one pitch of the teeth  251   a  of the partially toothed gear  251 , so that the partially toothed gear  251  can rotate by one pitch with respect to the second groove-forming member  256 . If the partially toothed gear  251  can rotate by at least one pitch, the teeth  251   a  of the partially toothed gear  251 , regardless of the position, can be adjusted to engage with the teeth  110   a  of the fourth gear  110 . Because the gap between the projection portion  260  and the recess portion  259  becomes the rotational angle loss with respect to the second groove-forming member  256  of the partially toothed gear  251 , it is better if the gap is smaller. By setting the gap between the projection portion  260  and the recess portion  259  to one pitch of the teeth  251   a  of the partially toothed gear  251 , therefore, the rotational angle loss can be minimized and the teeth  251   a  of the partially toothed gear  251  can smoothly be engaged with the teeth  110   a  of the fourth gear  110  without applying a large load. 
   The partially toothed gear  251  of the cylindrical cam  234  can smoothly engage with the fourth gear  110  with a small load and can reliably rotate the cylindrical cam  234  upon reception of the drive force from the fourth gear  110 . Therefore, the positioning member  262   a  inserted in the cam groove  252  formed in the cylindrical cam  234  can surely be guided to the individual guide portions  252   a ,  252   b  and  252   c  to reliably carry out elevation of the wiper support member  261  over a long period of time. As a result, the recording head  28  can be wiped clean reliably over a long period of time by the wiping member  263  and the nozzle protecting device  30  can carry out an adequate cleaning operation for a long period of time. 
   As the nozzle protecting device  30  performs an adequate cleaning operation for a long period of time, the recording head  28  can be kept in good condition over a long period of time. Therefore, the recording apparatus  11  can discharge the individual inks from the ink cartridges  21  and  22  at a predetermined timing and print a clear image. 
   As the projection portions  260  formed on the partially toothed gear  251  are fitted in the recess portions  259  formed in the second groove-forming member  256 , the partially toothed gear  251  is provided on the cylindrical cam  234 . Therefore, the partially toothed gear  251  can be provided on the cylindrical cam  234  with a simple structure in such a way that the partially toothed gear  251  is rotatable within a predetermined range with respect to the second groove-forming member  256 . 
   The cam groove  252  that guides the positioning member  262   a , which determines the elevation position of the wiping member  263 , in the up and down direction is formed on the cylindrical cam  234 . It is therefore possible to elevate the wiping member  263  via the positioning member  262   a  by the rotation of the cylindrical cam  234  with a simple structure. 
   The driven gear  242 , which engages with the fourth gear  110  and rotates about the rotational axial center C, is provided in such a way as to be aligned with the partially toothed gear  251 . This can reduce the space needed for the arrangement of the driven gear  242 . The fourth gear  110  whose lower side engages with the partially toothed gear  251  and whose upper side engages with the driven gear  242  has such a shape that the upper side and lower side have the same diameter. In other words, the fourth gear  110  need not be formed into a complex shape so that the structure can be simplified. 
   The rotation restriction groove  253  of the cylindrical cam  234  restricts the cylindrical cam  234  in such a way that the cylindrical cam  234  does not rotate over a predetermined range. Even if the cylindrical cam  234  receives, for example, the torque from the driven gear  242 , therefore, it does not rotate over the predetermined range and malfunction. Even if the drive motor  38  keeps rotating to drive the tube pump  233 , therefore, the wiper support member  261  can be elevated at a predetermined timing. 
   A fourth embodiment embodying the present invention will be described below based on  FIGS. 24 to 26 .  FIGS. 24 to 26  are bottom views for explaining a partially toothed gear  271  according to this embodiment. 
   Like the partially toothed gear  251  in the embodiment in  FIGS. 16 to 23 , the partially toothed gear  271  having a ring-like shape is provided on the second groove-forming member  256  of the cylindrical cam  234  in such a way as to be aligned with the driven gear  242  and rotate about the rotational axial center C. Teeth  271   a  are formed on only about half the circumferential surface of the partially toothed gear  271 . The teeth  271   a  are formed at the same pitches a as the driven gear  242  and engage with the fourth gear  110 . The upper sides of the teeth  110   a  of the fourth gear  110  engage with the teeth  242   a  of the driven gear  242  and the lower sides engage with the teeth  271   a  of the partially toothed gear  271  at the same time. 
   Two cutaway portions  272   a  and  272   b  are formed on the circumferential portion of the partially toothed gear  271  radially inward of the teeth  271   a  in such a way as to respectively correspond to both end portions of the teeth  271   a  (three teeth  271   a  at both end portions). The cutaway portions  272   a  and  272   b  allow for bending of the three teeth  271   a  in the direction of the rotational axial center C of the partially toothed gear  271 . Specifically, at the time the partially toothed gear  271  engages with the fourth gear  110 , when the threads of the teeth  110   a  of the fourth gear  110  abut on the threads of the teeth  271   a , the cutaway portions  272   a  and  272   b  cause the teeth  271   a  to be bent toward the center of the partially toothed gear  271 . 
   The teeth  271   a  which are positioned at the end portion E where the teeth  271   a  of the partially toothed gear  271  shown in  FIG. 24  are formed at such a position as to approximately face the fourth gear  110  at the time the cleaning operation in which the stop member  254  abuts on the end portion  253   a  of the rotation restriction groove  253  starts. That is, as the fourth gear  110  rotates in the direction r 1 , the teeth  271   a  of the partially toothed gear  271  soon engages and the partially toothed gear  271  rotates in the direction r 2 . 
   The partially toothed gear  271  has two projection portions  273  constructed like the projection portions  260  formed on the partially toothed gear  251  in the embodiment in  FIGS. 16 to 23 . Each projection portion  273  engages with the associated recess portion  259  of the second groove-forming member  256 . That is, the partially toothed gear  271  can rotate by the pitch a of the teeth  271   a  with respect to the second groove-forming member  256  as per the embodiment in  FIGS. 16 to 23 . 
   With the above-described structure, the driven gear  242  is aligned with the partially toothed gear  271  so that the driven gear  242  can rotate with respect to the cylindrical cam  234  and rotates about the rotational axial center C of the cylindrical cam  234 . 
   The action of the partially toothed gear  271  will be described next. 
   When the drive motor  38  is switched to the reverse rotation from the state where the partially toothed gear  271  is not engaged with the fourth gear  110 , the fourth gear  110  rotates in the direction opposite to the direction r 1 , as shown in  FIG. 24 . Upon reception of the torque from the fourth gear  110  via the driven gear  242 , the partially toothed gear  271  rotates in the direction opposite to the direction r 2 . The teeth  271   a  of the partially toothed gear  271  tries to rotate to the position facing the fourth gear  110  and engage with it. 
   In the case where the threads of the partially toothed gear  271  at the position facing the fourth gear  110  abut on the threads of the teeth  110   a  of the fourth gear  110  but are not in alignment at this time, the teeth  271   a  are bent toward the rotational axial center C by the cutaway portion  272   b  as shown in  FIG. 25 . With the rotation of the fourth gear  110 , the threads of the teeth  271   a  and the threads of the teeth  110   a  which are in abutment with the teeth  271   a  start shifting and the teeth  271   a  eventually engage with the teeth  110   a . And, the partially toothed gear  271  rotates in the direction opposite to the direction r 2  as shown in  FIG. 26 . 
   As the teeth  271   a  are bent by the cutaway portion  272   b , the partially toothed gear  271  can smoothly engage with the fourth gear  110 . 
   The present embodiment has the following advantages in addition to the advantages of the embodiment in  FIGS. 16 to 23 . 
   The two cutaway portions  272   a  and  272   b  are formed on the circumferential portion of the partially toothed gear  271 . They can bend the teeth  271   a  even if the threads of the teeth  271   a  abut on the threads of the teeth  110   a  when the partially toothed gear  271  engages with the fourth gear  110 , thereby reducing the load on the partially toothed gear  271  and the fourth gear  110  so that smooth engagement can take place. As a result, the partially toothed gear  271  and the fourth gear  110  can have longer lives. Further, the formation of the cutaway portions  272   a  and  272   b  can provide the teeth  271   a  of the partially toothed gear  271  with flexibility without complicating the structure. 
   As the partially toothed gear  271  of the cylindrical can  234  bends the teeth  271   a , it can engage with the fourth gear  110  smoothly with a smaller load, and with the engagement, the partially toothed gear  271  can receive the drive force from the fourth gear  110  and reliably rotate the cylindrical cam  234 . It is therefore possible to surely guide the positioning member  262   a  inserted in the cam groove  252  formed in the cylindrical cam  234  to the individual guide portions  252   a ,  252   b  and  252   c  to reliably execute elevation of the wiper support member  261  over a long period of time. Consequently, the recording head  28  can reliably be wiped clean with the wiping member  263  for a long period of time. Accordingly, the nozzle protecting device  30  can carry out an adequate cleaning operation for a long period of time. 
   A recording apparatus  311  according to a fifth embodiment of the present invention will be described below based on  FIGS. 27 to 32 . The recording apparatus  311  in the present embodiment has an elevation mechanism which elevates the guide member  15  and a cylindrical cam  334  which differs in structure from the cylindrical cam  234 , as compared with the structure of the recording apparatus  11  in  FIGS. 16 to 23 . 
   As shown in  FIG. 27 , the recording apparatus  311  has a platen  313  which extends in the direction of the arrow x and has a flat surface. The platen  313  is a support to support a target T, such as ordinary paper or a CD-ROM. 
   The recording apparatus  311  has an unillustrated thickness sensor in the vicinity of an unillustrated drive roller which is driven by the feed motor  14 . The thickness sensor detects whether the target T fed to the recording apparatus  311  is thick or not. 
   A support hole  320   a  is formed in the carriage  16  provided in the recording apparatus  311  as shown in  FIGS. 28(   a ) and  28 ( b ). The guide member  15  laid out in parallel to the timing belt  17  is inserted in the support hole  320   a . The carriage  16  reciprocates in the direction of the arrow x via the timing belt  17  by the driving of the carriage motor  18  while being guided to the guide member  15 . 
   Next, a guide mechanism  300  including the guide member  15  and the elevation mechanism for the guide member  15  are discussed based on  FIGS. 28(   a ) and  28 ( b ).  FIG. 28(   a ) shows the carriage  16  at a lower position and  FIG. 28(   b ) shows the carriage  16  lifted up to an upper position. 
   The guide mechanism  300  includes the guide member  15 , an outer cylinder member  325   a  fixed to the support hole  320   a  of the carriage  16  and a center shaft  326  rotatably supported on the outer cylinder member  325   a . Two eccentric shafts  327  eccentric to the axial center of the center shaft  326  are fixed to corresponding end portions of the guide member  15 . Both eccentric shafts  327  are rotatably supported on the frame  12  (see  FIG. 27 ). An actuation lever  328  is fixed to the right eccentric shaft  327 . An actuation groove  328   a  is formed in the actuation lever  328 . 
   A reversible motor M is secured to the frame  12  shown in  FIG. 27 . The reversible motor M is driven based on a signal from the thickness sensor or the thickness of the target T. As shown in  FIGS. 28(   a ) and  28 ( b ), the proximal end of an arm lever  329  is fixed to the rotary shaft, Ma, of the reversible motor M. The arm lever  32 R is rotatable along the direction r. The arm lever  329  is coupled to the actuation groove  328   a  of the actuation lever  328  slidably and rotatably. As the reversible motor M is rotated to turn the arm lever  329  along the direction r, both eccentric shafts  327  rotate and the center shaft  326  fixed to the eccentric shafts  327  rotates about the eccentric shafts  327  and are lowered. As a result, the carriage  16  is elevated, changing a distance PG 1 , PG 2  from the platen  313  to the recording head  28 . 
   As shown in  FIG. 29 , a cam groove  355  different in structure from the cam groove  252  of the cylindrical cam  234  in  FIG. 16  is formed in the circumferential surface of the cylindrical cam  334 . The cam groove  355  includes a retreat guide portion  356 , an action guide portion  357  and a standby guide portion  358 , as shown in  FIG. 30 . The retreat guide portion  356  extends along the circumferential direction at the lowermost portion of the cylindrical cam  334 . The retreat guide portion  356  is formed in a range of angle, θ=about −9° to about 6°, provided that a line OC (see  FIG. 21 ) connecting the center of the stop member  254  to the rotational axial center C of the cylindrical cam  334  is 0°, as shown in  FIG. 30 . 
   As shown in  FIG. 30 , the action guide portion  357  is formed in a range of angle, θ=about 6° to about 56°. The action guide portion  357  has a first inclined portion  357   a  obliquely extending upward from the retreat guide portion  356 , and a first position guide portion  357   b  extending along the circumferential direction from the first inclined portion  357   a . The first position guide portion  357   b  is at the position of the angle, θ=about 25°. Further, the action guide portion  357  has a second inclined portion  357   c  obliquely extending upward from the first position guide portion  357   b , and a second position guide portion  357   d  extending along the circumferential direction from the second inclined portion  357   c . The second position guide portion  357   d  is at the position of the angle, θ=about 50°. When the cylindrical cam  334  is rotated about 25° in the direction r 2  (see  FIG. 21 ) from the position shown in  FIG. 30 , therefore, the first position guide portion  357   b  reaches right above the stop member  254 , and when the cylindrical cam  334  is rotated about 50°, the second position guide portion  357   d  reaches right above the stop member  254 . That is, the action guide portion  357  has the first position guide portion  357   b  and the second position guide portion  357   d  as plural positions of action of different heights. 
   The standby guide portion  358  is formed in a range of angle, θ=about 56° to about 200°. As the stop member  254  abuts on the portion  253   b  of the rotation restriction groove  253  of the cylindrical cam  334 , the end portion of the standby guide portion  358  is positioned. That is, the cam groove  355  is formed in approximately the same range as the range where the rotation of the cylindrical cam  334  is restricted. The standby guide portion  358  includes a standby inclined portion  358   a  obliquely extending downward from the second position guide portion  357   d  of the action guide portion  357  and a standby portion  358   b  extending along the circumferential direction from the lower end of the standby inclined portion  358   a.    
   As shown in  FIG. 29 , when the positioning member  262   a  slides in the retreat guide portion  356  or the standby portion  358   b  of the standby guide portion  358 , the positioning member  262   a  is guided to the position of non-action at the lowest position. When the positioning member  262   a  slides in the first position guide portion  357   b  of the action guide portion  357 , the holding member  262  is guided to a first position of action. When the positioning member  262   a  slides in the second position guide portion  357   d , the holding member  262  is guided to a second position of action higher than the first position of action. Further, when the positioning member  262   a  slides in the first inclined portion  357   a  of the action guide portion  357 , the holding member  262  is guided to the first position guide portion  357   b  from the retreat position. When the positioning member  262   a  slides in the second inclined portion  357   c  of the action guide portion  357 , the holding member  262  is guided to the second position guide portion  357   d  from the first position guide portion  357   b . Further, when the holding member  262  slides in the standby inclined portion  358   a  of the standby guide portion  358 , the holding member  262  is guided to the standby portion  358   b  of the standby guide portion  358  from the second position guide portion  357   d  of the action guide portion  357 . 
   When the stop member  254  abuts on the end portion  253   a  of the rotation restriction groove  253  of the cylindrical cam  334  (see  FIG. 21 ), the positioning member  262   a  is positioned at the position where it abuts on a start end portion S of the retreat guide portion  356  of the cam groove  355 . In this state, the holding member  262  is positioned at the position of non-action. When the fourth gear  110  is rotated in the direction r 1  from this state, the driven gear  242  and the partially toothed gear  251  rotate in the direction r 2 . Accordingly, the cam groove  355  of the cylindrical cam  334  rotates and the positioning member  262   a  slides to contact the standby portion  358   b  from the retreat guide portion  356  of the cam groove  355  through the first inclined portion  357   a , the first position guide portion  357   b , the second inclined guide portion  357   c  and the second position guide portion  357   d  of the action guide portion  357  and the standby inclined portion  358   a  of the standby guide portion  358  in that order. 
   When the positioning member  262   a  slides to contact the first inclined portion  357   a  of the action guide portion  357  toward the first position guide portion  357   b , the wiper support member  261  is moved upward. When the cylindrical cam  334  is rotated about 25°, the wiper support member  261  reaches the first position of action where it slides to contact the first position guide portion  357   b . When the positioning member  262   a  slides to contact the second inclined portion  357   c  toward the second position guide portion  357   d  from the first position guide portion  357   b , the wiper support member  261  is moved upward. When the cylindrical cam  334  is rotated about 200°, the wiper support member  261  reaches the second position of action where it slides to contact the second position guide portion  357   d.    
   When the cylindrical cam is rotated about 200° and the stop member  254  abuts on the first end portion  253   b  of the rotation restriction groove  253 , the positioning member  262   a  abuts on the end portion E of the standby portion  358   b  of the standby guide portion  358  of the cam groove  355 . The partially toothed gear  251  engages with the fourth gear  110  only in the range where the positioning member  262   a  moves from the retreat guide portion  356  of the cam groove  355  to the standby guide portion  358  through the action guide portion  357 . 
   As the drive motor  38  is rotated reversely, the positioning member  262   a  slides to contact the retreat guide portion  356  from the standby guide portion  358  through the action guide portion  357  in reverse order to the above-described order. When the stop member  254  is rotated about 150° from the state where the stop member  254  abuts on the end portion  253   b  or the state where the positioning member  262   a  is positioned at the end portion E of the standby portion  358   b , the positioning member  262   a  reaches the second position of action for the second position guide portion  357   d . When the positioning member  262   a  is rotated about 175° from the state where it is positioned at the end portion E of the standby portion  358   b , the positioning member  262   a  reaches the first position of action for the first position guide portion  357   b.    
   As shown in  FIG. 29 , when the positioning member  262   a  is positioned in the retreat guide portion  356 , the wiping member  263  is positioned at the retreat position isolated from the recording head  28 . When the positioning member  262   a  is positioned at the first position of action for the first position guide portion  357   b  (see  FIG. 28(   a )), the platen  313  is separated from the end face of the recording head  28  by the distance PG 1 . At this time, as shown in  FIG. 31 , the distal end  263   a  of the wiping member  263  is positioned above by a predetermined height D from the line that extends from the end face of the recording head  28 . Further, when the positioning member  262   a  is positioned at the second position of action for the second position guide portion  357   d  (see  FIG. 28(   b )), the platen  313  is separated from the end face of the recording head  28  by the distance PG 2 . At this time, as shown in  FIG. 32 , the distal end  263   a  of the wiping member  263  is positioned above by the predetermined height D from the line that extends from the end face of the recording head  28  as in the state in  FIG. 31 . The wiper position adjusting means in this embodiment includes the cylindrical cam  334 , the holding member  262  and the positioning member  262   a.    
   The action of the above-described recording apparatus  311  will be described next. 
   When printing is carried out by the recording apparatus  311 , first, the target T is led into the recording apparatus  311  by the feed motor  14 . At this time, the thickness of the target T to be led is detected by the thickness sensor in the vicinity of the feed roller. Normally, the recording apparatus  311  is so set as to print on the relatively thin target T such as normal paper. In the case where the recording apparatus  311  determines that the relatively thin target T has been led, it keeps the carriage  16  at a low position as shown in  FIG. 28(   a ) without driving the reversible motor M. That is, in this case, the recording apparatus  311  prints with the setting of the distance PG 1  from the platen  313  to the recording head  28 . 
   The recording apparatus  311  further drives the feed motor  14  to guide the target T between the platen  313  and the recording head  28 . The recording apparatus  311  drives the piezoelectric element to eject inks supplied from the ink cartridges  21  and  22  toward the target T from the nozzles of the recording head  28  while reciprocating the carriage  16  along the direction x by driving the carriage motor  18 . When ejection from the recording head  28  is finished within the range where the carriage  16  can reciprocate, the recording apparatus  311  drives the feed motor  14  to feed the target T forward by a predetermined amount. Thereafter, the recording apparatus  311  drives the carriage motor  18  and the piezoelectric element again to eject inks from the recording head  28  while moving the carriage  16 . Printing on the target T is carried out by repeating these steps. 
   In the case where printing is finished and the cleaning operation for the recording head  28  is to be carried out, the recording apparatus  311  drives the carriage motor  18  to move the carriage  16  in the direction x to the position facing the cap  46 . At this time, the positioning member  262   a  of the wiper support member  261  is positioned at the retreat guide portion  356  of the cam groove  355 , as shown in  FIG. 29 . Even if the carriage  16  passes over the wiping member  263  in the direction x, the distal end  263   a  of the wiping member  263  does not abut on the recording head  28  of the carriage  16 . At this time, the stop member  254  abuts on the first end portion  253   a  of the rotation restriction groove  253  at the bottom of the cylindrical cam  234  and the tooth  251   a  positioned at the end portion E of the partially toothed gear  251  faces the fourth gear  110 . 
   When the carriage  16  reaches the position facing the cap  46 , the recording apparatus  311  stops driving the carriage motor  18  and rotates the drive motor  38  forward. As the drive motor  38  is rotated forward, the drive gear  38   a  rotates and the torque is transmitted to the fourth gear  110  via the first to third gears  107  to  109 . Accordingly, the fourth gear  110  is rotated in the direction r 1  and the driven gear  242  which engages with the fourth gear  110  is rotated in the direction r 2 . As the teeth  251   a  of the partially toothed gear  251  are at the position facing the fourth gear  110 , the teeth  251   a  of the partially toothed gear  251  engage with the fourth gear  110 . This causes the cylindrical cam  234  to rotate in the direction r 2 , rotating the cam groove  355 . As a result, the positioning member  262   a  reaches the standby guide portion  358  from the retreat guide portion  356  of the cam groove  355  through the action guide portion  357 , elevating the wiping member  263 . 
   When the positioning member  262   a  reaches the standby guide portion  358  and the cylindrical cam  234  makes about a half turn, the teeth  251   a  of the partially toothed gear  251  do not engage with the fourth gear  110 . As the driven gear  242  which slides in contact to the partially toothed gear  251  keeps rotating, however, the torque of the driven gear  242  is converted to frictional force which is transmitted to the partially toothed gear  251 , further rotating the cylindrical cam  234 . And, when the stop member  254  abuts on the first end portion  253   b  of the rotation restriction groove  253  or rotates about 200°, the rotation of the cylindrical cam  234  in the direction r 2  is stopped. 
   The cap support member  47  is elevated by the elevation mechanism which is driven by the transmitted torque of the driven gear  242  and the cap  46  guided to the position of action tightly closes the recording head  28 . Then, the tube pump  37  is driven via the third gear  109 , generating negative pressure in the tightly-closed space of the recording head  28 . Accordingly, high-viscosity inks, which would clog the nozzles of the recording head  28 , are exhausted to the waste liquid tank  40 . 
   When the drive motor  38  is switched to the reverse rotation thereafter, the fourth gear  110  is rotated in the direction opposite to the direction r 1 . Accordingly, the cylindrical cam  234  is rotated in the direction opposite to the direction r 2  via the driven gear  242 . When the positioning member  262   a  reaches the action guide portion  357  from the standby guide portion  358  thereafter, the partially toothed gear  251  engages with the fourth gear  110  also. When the cylindrical cam  234  is rotated about 175° in the direction opposite to the direction r 2  from the end portion E of the standby portion  358   b  of the standby guide portion  358 , the drive motor  38  is stopped. Before the drive motor  38  is stopped, the partially toothed gear  251  engages with the fourth gear  110  and further the positioning member  262   a  reaches the first position guide portion  357   b  through the second position guide portion  357   d  and the second inclined guide portion  357   c  of the cam groove  355 . 
   When the cylindrical cam  234  is stopped at the position of 25° rotation since the beginning of cleaning, as shown in  FIG. 31 , the positioning member  262   a  is positioned at the standby guide portion  358 . Accordingly, the wiping member  263  is placed at the first position of action. This causes the distal end of the wiping member  263  to be positioned above the recording head  28  by the predetermined height D. 
   The cap support member  47  is lowered by the elevation mechanism and the cap  46  is positioned at the position of non-action so that the carriage  16  becomes movable. The recording apparatus  311  drives the carriage motor  18  to move the carriage  16  in the direction of the arrow x from above the cap  46 . Then, the carriage  16  abuts on the wiping member  263  and moves in the direction opposite to the direction x, so that the wiping member  263  is bent by the moving carriage  16  and its distal end  263   a  abuts on the recording head  28 . The further movement of the carriage  16  causes the wiping member  263  to move with respect to the recording head  28  and perform wipe and cleaning to wipe off the entire surface of the recording head  28 . 
   When cleaning of the recording head  28  by the wiping member  263  is finished, the recording apparatus  311  reversely rotates the drive motor  38  again. Therefore, the fourth gear  110  is rotated in the direction opposite to the direction r 1  again so that the driven gear  242  and the partially toothed gear  251  rotate in the direction opposite to the direction r 2 . Therefore, the cylindrical cam  234  rotates in the direction opposite to the direction r 2 . Accordingly, the positioning member  262   a  reaches the retreat guide portion  356  through the first inclined portion  357   a  of the action guide portion  357 . As the cylindrical cam  234  is rotated to the position at which cleaning starts (see  FIG. 21 ), the stop member  254  abuts on the first end portion  253   a  of the rotation restriction groove  253 . This restricts the rotation of the cylindrical cam  234  so that the cylindrical cam  234  stops rotating in the direction opposite to the direction r 1  and stops. Thereafter, the rotation of the drive motor  38  is stopped. 
   Next, a case where printing is done on the thick target T such as a CD-ROM in place of normal paper will be described. When the target T is led by the feed motor  14 , the thickness sensor in the recording apparatus  311  detects the thickness of the target. When the recording apparatus  311  determines that the target is thicker than a predetermined value, the recording apparatus  311  drives the reversible motor M to rotate the arm lever  329 . Accordingly, the carriage  16  comes to the state in  FIG. 28(   b ) where it is lifted by a height H from the state in  FIG. 28(   a ). That is, the distance PG 1  from the platen  313  to the recording head  28  is changed to the distance PG 2  greater than the distance PG 1 . 
   Thereafter, at the time the drive motor  38  is rotated forward and then rotated reversely in the cleaning operation, the carriage  16  is at an upper position, so that the drive motor  38  temporarily stops after being rotated 150°, not 175°, from the end wall of the standby portion  358   b  of the standby guide portion  358 . That is, it temporarily stops in a state where it is rotated by the angle, θ=50° (see  FIG. 21 ). 
   As shown in  FIG. 32 , the positioning member  262   a  is positioned at the second position guide portion  357   d  of the cam groove  355 , the holding member  262  is guided to the second position of action and the end face of the distal end  263   a  of the wiping member  263  projects out from the line extending from the end face of the recording head  28  by the predetermined height D. Even when the distance PG 1  (see  FIG. 28(   a )) from the platen  313  to the recording head  28  is changed to the distance PG 2  (see  FIG. 28(   b )), therefore, a distance D from the end face of the distal end  263   a  of the wiping member  263  to the recording head  28  is always constant and the wiping member  263  performs wiping and cleaning in this state. 
   If the thin target T is led to the recording apparatus  311  to perform printing on the target T, the thickness is detected by the thickness sensor and the reversible motor M coupled to the arm lever  329  is rotated reversely. Accordingly, the recording head  28  is lowered to the position shown in  FIG. 28(   a ) from the position shown in  FIG. 28(   b ). In the case where cleaning is carried out in this state, the drive motor  38  rotated forward temporarily stops in the state where it is rotated 175° from the end wall of the standby portion  358   b . With the distal end  263   a  of the wiping member  263  always positioned above the end face of the recording head  28  by the predetermined height D, the wiping member  263  wipes the recording head  28  clear. 
   The present embodiment has the following advantages. 
   As shown in  FIGS. 28(   a ) and  28 ( b ), the elevation position of the wiping member  263  is changed according to the distance PG 1 , PG 2  from the platen  313  to the end face of the recording head  28 . Even when the recording head  28  is elevated and the distance PG 1 , PG 2  is changed, however, the distal end  263   a  of the wiping member  263  is always placed above the end face of the recording head  28  by the same height D. This can make the interference portion of the wiping member  263  with respect to the recording head  28  constant, so that the wiping member  263  can always adequately wipe the recording head  28  clear. Therefore, the recording head  28  can always eject inks that are in a good condition. 
   The positioning member  262   a  which is guided in the up and down direction as it slides in the cam groove  355  formed in the cylindrical cam  234  is coupled to the holding member  262  which supports the wiping member  263 . Accordingly, as the cylindrical cam  234  rotates, the positioning member  262   a  slides in the cam groove  355 , elevating the wiping member  263 . The position of the wiping member  263  can therefore be adjusted easily with a simple structure. 
   As shown in  FIGS. 28(   a ) and  28 ( b ), each distance PG 1 , PG 2  from the platen  313  to the recording head  28  is adjusted by elevating the recording head  28 . That is, because the carriage  16  alone is elevated, each distance PG 1 , PG 2  from the platen  313  to the recording head  28  can be adjusted easily without applying a large load. 
   The cam groove  355  has the retreat guide portion  356  which does not abut on the carriage  16  even if the carriage  16  passes above, the first position guide portion  357   b  at which the holding member  262  is set at the first position of action and the second position guide portion  357   d  at which the holding member  262  is set at the second position of action. With the positioning member  262   a  positioned at the retreat guide portion  356  and the wiping member  263  at the retreat position isolated from the recording head  28 , the recording head  28  passes over the wiping member  263 , so that the wiping member  263  does not receive force from the recording head  28 . Accordingly, unnecessary force is not applied to the wiping member  263 , thus making it possible to extend its life. 
   The cam groove  355  has the horizontal portion where the first position guide portion  357   b  and the second position guide portion  357   d  are formed on the circumferential surface of the cylindrical cam  234 . That is, the first and second position guide portions  357   b  and  357   d  for positioning the wiping member  263  are the horizontal portion of a predetermined length. Even if there is an error in the rotational angle at which the cylindrical cam  234  temporarily stops, therefore, the position of the wiping member  263  is elevated to a predetermined height. That is, the wiping member  263  can be adjusted to a predetermined position even if the rotation of the cylindrical cam  234  is not strictly controlled to stop. 
   Only the wiping apparatus  235  which is a part of the nozzle protecting device  30  is elevated based on each distance PG 1 , PG 2 . This makes it possible to easily elevate the wiping member  263  with a smaller load as compared with elevation of the entire nozzle protecting device  30 . 
   As the recording apparatus  311  automatically discriminates the thickness of the target T to be led out, each distance PG 1 , PG 2  from the platen  313  to the recording head  28  as well as the position of the wiping member  263  is adjusted. This can allow the wiping member  263  to adequately wipe the recording head  28  clear and can make it unnecessary to adjust the distance PG 1 , PG 2  on the user side, so that inks can be ejected to the target T more adequately. 
   Next, a sixth embodiment of the present invention will be described based on  FIG. 33 . This embodiment differs from the embodiment in  FIGS. 27 to 32  only in the shape of the cam groove  355  and the same symbols as with the embodiment in  FIGS. 27 to 32  are used with similar portions and their detailed descriptions are omitted. 
   A cam groove  455  in this embodiment has a retreat guide portion  466  positioned below the cylindrical cam  234 , an action guide portion  467  obliquely extending upward from the retreat guide portion  466  and a standby guide portion  468  extending along the circumferential direction from the action guide portion  467 . The action guide portion  467  is straight. The action guide portion  467  becomes the same height as the first position guide portion  357   b  in  FIG. 30  when rotated by an angle, θ=25° and becomes the same height as the second position guide portion  357   d  in  FIG. 30  when rotated by 50°. That is, if the drive motor  38  is temporarily stopped at a rotational angle similar to that in the embodiment in  FIGS. 27 to 32  when the drive motor  38  rotates reversely, the holding member  262  is placed at the first position of action or the second position of action via the positioning member  262   a  inserted in the cam groove  455 . In the present embodiment, the standby guide portion  468  is formed at an upper position. When the positioning member  262   a  is positioned at the standby guide portion  468 , the carriage  16  moves to the position facing the cap  46  and does not pass over the wiping member  263  so that the wiping member  263  is not subjected to force from the recording head  28 . 
   The present embodiment has the following advantages below in addition to the advantages, such as the recording head always ejecting inks or easy adjustment of the position of the wiper member. 
   The cam groove  455  includes the retreat guide portion  466  extending in the circumferential direction, and the standby guide portion  468  and the action guide portion  467 , which connects them in a straight line. That is, because the cam groove  455  has a simpler shape as compared with the cam groove  355  in the embodiment in  FIGS. 27 to 32 , the cam groove  455  can be formed easily. 
   The action guide portion  467  which determines the position of action of the positioning member  262   a  is inclined to be straight. This makes it possible to easily adjust the position at which the cylindrical cam  234  temporarily stops or the rotational angle of the drive motor  38  at the time the wiping member  263  wipes the recording head  28  clean. Therefore, the optimal position at which the wiping member  263  wipes the recording head  28  clean can be acquired merely by a simple operation of delicately adjusting the rotational angle of the drive motor  38 . 
   The above-described embodiments of the present invention may be modified as follows. 
   In the embodiment in  FIGS. 1 to 11 , if the inside of the cap  46  can be opened to and blocked from air by changing the relative distance between the cap  46  and the cap support member  47 , other air release means may be used as well. 
   In the embodiments in  FIGS. 1 to 15 , the valve body  58 ,  126  may also be formed of a flexible material. The valve body  58 ,  126  may alone be formed of a flexible material. Further, both the valve seat  56 ,  123  and the valve body  58 ,  126  may be formed of a material other than a flexible material. 
   In the embodiment in  FIGS. 1 to 11 , if the valve seat  56  and the valve body  58  can abut on and part from each other by changing the relative distance between the cap  46  and the cap support member  47 , the valve seat  56  and the valve body  58  may be provided on other walls of the cap  46 . 
   In the embodiment in  FIGS. 1 to 11 , the valve body  58  may be urged in a direction to abut on the valve seat  56  by the spring member  58   a  and other urging means. The valve seat  56  and the valve body  58  may be made to abut on each other without using the spring member  58   a  but by other means. In the embodiment in  FIGS. 12 to 15 , likewise, the valve body  126  may be urged in a direction to abut on the valve seat  123  by the spring member  125  and other urging means. The valve seat  123  and the valve body  126  may be made to abut on each other without using the spring member  125  but by other means. 
   In the embodiment in  FIGS. 1 to 11 , when the relative distance between the cap support member  47  and the cap  46  is maximum, the lever  73  may be positioned within the movable range of the plate  61  or above the plate  61 . As a result, when the lever  73  is lifted upward, the plate  61  is positioned under the lever  73  so that the plate  61  does not interfere with the elevation of the lever  73 . Because it is unnecessary to slide the lever  73  to lift the lever  73  upward, the apparatus can be simplified. 
   In the embodiment in  FIGS. 1 to 11 , for example, the contact surfaces of the plate  61  and the lever  73  may be set curved surfaces so that the lever  73  slides. 
   In the embodiment in  FIGS. 1 to 11 , the lever  73  may be urged in the slide direction by the spring member  77  and other urging means. 
   In the individual embodiments in  FIGS. 1 to 15 , if the cap support member  47 ,  121  can be moved up and down, the drive force from the drive motor  38  may be transmitted via other transmission means in place of the cylindrical cam  35 . 
   In the individual embodiments in  FIGS. 1 to 15 , the cylindrical cam  35  is not restrictive, but other cams, e.g., a spherical cam, a conical cam, a flat-plate cam or the like, may be used. 
   In the individual embodiments in  FIGS. 1 to 15 , instead of transmitting the drive force from the drive motor  38  to the cylindrical cam  35  and the tube pump  37  with a predetermined phase difference, they may be driven by separate drive means respectively. 
   In the individual embodiments in  FIGS. 1 to 15 , the liquid ejection apparatus may be an apparatus which ejects other liquids as well as a printing apparatus including a facsimile or a copying machine. For example, it may be a liquid ejection apparatus, which ejects liquids for the electrode materials or color materials to be used in manufacturing a liquid crystal display, an EL display, a surface emission display (FED) or the like, a liquid ejection apparatus, which ejects a living organic material to be used in a bio chip, or a sample ejection apparatus, such as a fine pipette. 
   In the embodiment in  FIGS. 12 to 15 , other air release means may be used if the inside of the cap  120  can be opened and closed to air by changing the distance between the cap support member  121  and the partition  133 . 
   In the embodiment in  FIGS. 12 to 15 , the air tube  122  may be attached to the other wall of the cap support member  121  other than by that which lies on the third retaining portion  43  side and further, the valve body  126  may likewise be attached to the same wall in such a way as to rotatably abut on the valve seat  123 . Accordingly, the partition  133  should be provided in such a way that its abutment portion  134  abuts on the projection  129  of the valve body  126 . 
   In the embodiment in  FIGS. 12 to 15 , air in the cap  120  has only to be non-released by causing the valve body  126  to abut on the opening of the valve seat  123 . In the case where the opening of the valve seat  123  is on the left-hand side, for example, the valve body  126  may be provided to the left to the opening, and in the case where the opening of the valve seat  123  is on the upper side, the valve body  126  may be provided on the upper side. At this time, the position of the abutment portion  134  may be changed adequately. 
   In the embodiment in  FIGS. 16 to 23 , for example, the cam groove  252  may be formed in the cylindrical cam  234  and the two members, the first groove-forming member  255  and the second groove-forming member  256 , may be formed by a single member. 
   In the individual embodiments in  FIGS. 16 to 33 , the partially toothed gear  251  may be provided on a portion other than the upper side of the cylindrical cam  234 , e.g., on the lower side. 
   In the individual embodiments in  FIGS. 16 to 33 , the gap at the time the projection portions  260  of the partially toothed gear  251  are inserted in the recess portions  259  of the second groove-forming member  256  may be set to other than one pitch. If the gap is smaller than one pitch, engagement can be done more smoothly than in the prior art and the rotational loss with respect to the cylindrical cam  234  of the partially toothed gear  251  can be reduced. 
   In the individual embodiments in  FIGS. 16 to 33 , recess portions may be formed in the partially toothed gear  251  and projection portions which are fitted in the recess portions may be formed on the second groove-forming member  256 . 
   In the individual embodiments in  FIGS. 16 to 33 , the diameters of the partially toothed gear  251  and the driven gear  242  may differ from each other. In this case, with regard to the lower side of the fourth gear  110  with which the partially toothed gear  251  engages and the upper side of the fourth gear  110  with which the driven gear  242  engage, two gears of different diameters may be aligned with each other and placed as the fourth gear  110 . 
   In the individual embodiments in  FIGS. 16 to 33 , the partially toothed gear  251 , the fourth gear  110  and the driven gear  242  may be constituted by a gear other than a spur gear, for example, a helical gear. 
   In the individual embodiments in  FIGS. 16 to 33 , the cylindrical cam  234 ,  334  provided on the partially toothed gear  251  may be used in a mechanism other than the one which elevates the wiping member  263 . For example, the cylindrical cam  234 ,  334  may be used in an unillustrated mechanism which elevates the cap support member  47  so that the cap  46  is elevated by rotating the cylindrical cam  234 ,  334 . 
   In the individual embodiments in  FIGS. 27 to 33 , the second position of action may be provided at a position close to the retreat guide portion  356  which becomes the lowest portion at the time cleaning starts, and the first position of action lower than the second position of action may be provided at a position close to the standby guide portion  358 . 
   In the embodiment in  FIGS. 27 to 32 , more position guide portions  357   b ,  357   d  which become the horizontal portions of the action guide portion  357  may be provided. In the embodiment in  FIG. 33 , the timing of stopping the drive motor  38  when rotated reversely may be adjusted accurately. This can allow the wiping member  263  to always project from the end face of the recording head  28  by the predetermined height D even when the distance PG 1  (PG 2 ) between the platen  313  and the recording head  28  is continuously adjustable. 
   In the individual embodiments in  FIGS. 27 to 33 , each distance PG 1 , PG 2  may be changed by elevation of the platen  313  instead of the recording head  28 . 
   In the individual embodiments in  FIGS. 27 to 33 , each standby guide portion  358 ,  468  of the cam groove  355 ,  455  may be changed. As the positioning member  262   a  slides when the recording head  28  faces the cap  46 , both standby guide portions  358  and  468  do not receive force from the recording head  28  regardless of the height of the wiping member  263 .