Abstract:
In order to maintain an ink ejectability of a print head which ejects ink droplets to a recording medium, a wiper wipes a nozzle formation face of the print head. A wiper cleaner is formed with a slit which scrape away adhesions on the wiper when the wiper passes through the slit. A width of the slit is substantially identical with a thickness of the wiper.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an ink ejectability maintenance device for maintaining constant ink ejectability of a recording head for ejecting ink droplets toward a recording medium, as well as to an ink jet printer equipped with the ink ejectability maintenance device. 
     An ink jet printer is usually equipped with a print head mounted on a carriage which travels back and forth in a main scanning direction, and a medium feeder for intermittently feeding a recording medium, such as print paper, in a sub-scanning direction in preset increments. The print head is actuated in the main scanning direction while the recording medium is being fed in the sub-scanning direction, and ink droplets are ejected toward the recording medium from the print head. 
     A mono-color ink jet printer is usually equipped with one print head. In contrast, a full-color ink jet printer is equipped with a black-ink print head for ejecting black ink, and a plurality of color-ink print heads for ejecting various colors of ink, such as yellow, cyan, and magenta. 
     A print head of an ink jet printer of such a construction has a pressure generation chamber and a nozzle orifice communicated therewith. Ink is stored in a pressure generation chamber and pressurized at a predetermined pressure, whereby ink droplets of controlled size are ejected from the nozzle orifice to the recording medium. Accordingly, when variations arise in the ink ejectability of the nozzle orifice of the print head, the quality of a recorded image is greatly affected. Hence, the ink ejectability must be maintained constant at all times. 
     The ink ejectability is changed by various phenomena, such as an increase in viscosity or solidification due to evaporation or drying of solvent in ink by way of the nozzle orifice, clogging due to solid material, adhesion of dust to the nozzles, and intrusion of air bubbles into ink. In order to prevent occurrence of such a change in characteristic, the ink jet printer is equipped with an ink ejectability maintenance device which eliminates the above-described phenomena causing variations to maintain the ink ejectability constant. 
     The ink ejectability maintenance device is equipped with a capping device, a suction pump, and a wiping device. The capping device is arranged so as to seal a nozzle formation face of a print head when no recording operation is performed, thereby isolating the nozzle orifice from the outside. Thus, the ink ejectability maintenance device has the function of inhibiting evaporation and drying of ink, thereby hindering an increase in viscosity and solidification of ink. Even when the nozzle formation face is sealed with the capping device, there cannot be completely prevented occurrence of clogging due to solid material in the nozzle orifice or intrusion of air bubbles into an ink flow channel. The ink jet printer is further equipped with a suction pump for the purpose of completely preventing occurrence of these problems. 
     The suction pump is configured so as to exert negative pressure on the nozzle orifice while the nozzle formation face is sealed with the capping device. The suction pump has the function of forcefully causing ink to be discharged from the nozzle orifice through suction, thereby eliminating solid material or air bubbles. Forceful discharge of ink to be performed by the suction pump is usually carried out when a recording operation is resumed after the ink jet printer has remained inoperative for a long time period or when the user has actuated a specifically-designed switch provided in a control panel with the understanding that deterioration of recorded image quality. 
     When ink is forcefully discharged by the suction pump, ink may splash across a nozzle formation face of the printer head, and in each nozzle orifice an ink meniscus may be disturbed. The nozzle formation face of the print head becomes susceptible to adhesion of extraneous matter with lapse of time. Hence, the print head is equipped with a wiping device for wiping the nozzle formation face, as required. 
     The wiping device has a wiping member whose base end is caught by a holder, and is constituted of an elastic plate such as rubber. An edge of the extremity of the wiping member is elastically pressed against a nozzle formation face, thereby effecting relative reciprocal movement so as to wipe the nozzle formation face. As a result, ink or extraneous matter adhering to the nozzle formation face is wiped, and ink meniscuses of respective nozzle orifices are made uniform. In short, the wiping device has the function of making the nozzle formation face stable. 
     Since the cleaning property of the wiping member can be maintained constant by removing ink or extraneous matter adhering to the surface of the wiping member, the wiping device also has a cleaning member. As a cleaning method to be performed by the cleaning member, there has been adopted a general method in which a scraper is placed as a cleaning member in a position perpendicular to the moving direction of the wiping member. The wiping member is caused to come into collision with the scraper, thereby elastically deforming the wiping member. The wiping member is caused to pass through the scraper, thereby removing the ink adhering to the surface of the wiping member. 
     According to the cleaning method to be performed by such an ink ejectability maintenance device, when the wiping member comes into collision with the scraper, a collision sound arises. Acting as noise, the sound may adversely affect electronic components and induce faulty operation. Moreover, when the wiping member departs from the scraper, the wiping member is restored to its original shape, which may induce splashing of ink and deteriorate recording accuracy. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide an ink ejectability maintenance device capable of preventing occurrence of noise or splashing of ink, which would otherwise be caused when a wiping member is cleaned, as well as an ink jet printer equipped with the ink ejectability maintenance device. 
     In order to achieve the above object, according to the present invention, there is provided an ink ejectability maintenance device for maintaining an ink ejectability of a print head which ejects ink droplets to a recording medium, comprising: 
     a wiper, which wipes a nozzle formation face of the print head; and 
     a wiper cleaner formed with a slit, which removes adhesions on the wiper when the wiper passes through the slit. 
     Accordingly, the wiper cleaner can scrape away the ink or the like adhering to the wiper without involvement of collision with the wiper. Hence, there does not arise a faulty operation, which would otherwise be caused by noise such as collision sound. Further, the wiper is not subjected to elastic deformation or restoration. Hence, there does not arise deterioration in recording accuracy, which would otherwise be caused by splashing of ink. 
     Preferably, a width of the slit is substantially identical with a thickness of the wiper. Accordingly, both side surfaces of the wiper where adherents particularly remain when the print head is wiped away can be cleaned. 
     Preferably, the wiper and the wiper cleaner change their position in cooperation with each other. 
     Accordingly, adherents adhering to the area where an interference arises between the wiper and the print head can be wiped away completely. The load imposed on the wiper when the wiper passes through the slit of the wiper cleaner can be reduced by minimizing a wiping range. 
     Here, it is preferable that the wiper is movable between a wiping position and a non-wiping position, and passes through the slit while moving from one of the wiping position and the non-wiping position to the other. 
     Accordingly, the wiper can be cleaned at all times after the wiper has wiped away the print head. 
     Further, it is preferable that the wiper cleaner is pivotably held on the device. 
     Accordingly, the wiper cleaner can readily effect cooperative movement relative to the wiper. Thus, adherents adhering to the wiper can be wiped away completely. 
     Still further, it is preferable that the wiper cleaner is provided with a guide pin which is fitted with a guide groove formed on a wiper holder which holds the wiper. 
     Accordingly, the wiper cleaner can follow movement of the wiper at all times, thereby completely wiping away adherents adhering to the wiper. 
     In order to attain the above advantages, according to the present invention, there is also provided an ink jet printer comprising the above ink ejectability maintenance device. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above objects and advantages of the present invention will become more apparent by describing in detail preferred exemplary embodiments thereof with reference to the accompanying drawings, wherein: 
     FIG. 1 is a perspective view showing the whole configuration of an ink jet printer according to one embodiment of the invention; 
     FIG. 2 is a perspective view showing an ink ejectability maintenance device assembled into the ink jet printer; 
     FIG. 3 is a perspective view of the ink ejectability maintenance device shown in FIG. 2 when viewed from the back; 
     FIG. 4 is an exploded perspective view of the ink ejectability maintenance device shown in FIG. 2; 
     FIG. 5 is a perspective view showing a detailed layout relationship between the principal section of a wiping unit and a gear-operated cam of a capping unit of the ink ejectability maintenance device; 
     FIGS. 6 through 17 are diagrams showing the operation of the wiping unit shown in FIG. 5; 
     FIGS. 18 through 21 are diagrams showing the operation of the capping unit shown in FIG. 5; 
     FIG. 22 is a timing chart showing the whole operation of the ink ejectability maintenance device shown in FIG. 2; 
     FIGS. 23 through 31 are diagrams showing the whole operation of the ink ejectability maintenance device shown in FIG. 2; and 
     FIG. 32 is a perspective view showing another configuration example of an ink ejectability maintenance device. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An embodiment of the invention will be described in detail hereinbelow by reference to the accompanying drawings. 
     An ink jet printer shown in FIG. 1 is a large printer capable of printing data onto print paper of relatively large size; e.g., paper of 594 mm (JIS A1-size paper) or paper of 728 mm (JIS B1-size paper). 
     In the ink jet printer, a paper feed section  11 , a recording section  12 , and a paper discharge section  13  are aligned so as to be parallel and to assume a diagonal relationship; specifically, the lower paper discharge section  13  is located closer to the operator than is the upper paper feed section  11 . Print paper is discharged outside after having been subjected to predetermined printing during the course of being supplied from the paper feed section  11  to the paper discharge section  13  by way of the recording section  12 . A paper transporting path  14  constituted at the time of printing is formed at an inclination of, e.g., 65 degrees, with respect to a horizontal plane. A nozzle formation face of a print head  18  mounted on a carriage  17 , which travels back and forth in the main scanning direction along a guide shaft  16  by a driving belt  15 , is provided at an angle of, e.g., 65 degrees, so as to become parallel with the paper transporting path  14 . 
     An ink ejectability maintenance device  100  for maintaining the ink ejectability of the print head  18  constant is disposed in a position which serves as the home position of the carriage  17 . While the carriage  17  is situated at the home position, the ink ejectability maintenance device  100  performs an operation for maintaining the ink ejectability of the print head  18 . 
     As shown in FIGS. 2,  3 , and  4 , the ink ejectability maintenance device  100  has a wiping unit  110 , a capping unit  130 , a suction unit  150 , and driving unit  170  for driving these means. In order to show the internal construction of the ink ejectability maintenance device  100 , one side frame  101  shown in FIG. 4 is omitted from FIG.  2 . On the other hand, another side frame  102  shown in FIG. 4 is omitted from FIG.  3 . Further, in order to simplify an illustration, the suction unit  150  is omitted from FIG.  4 . 
     In the ink ejectability maintenance device  100 , interposed between the two side frames  101 ,  102  are the wiping unit  110  for wiping a nozzle formation face in the main scanning direction of the print head  18  designated by arrow “a” shown in FIGS. 2 and 3; that is, a horizontal direction; the capping unit  130 , which is pressed against the nozzle formation face of the print head  18  at the time of non-printing operation, to thereby seal the nozzle orifice; the suction unit  150  for forcefully discharging ink through suction for eliminating clogging in the nozzle orifice or air bubbles intruded into the nozzle orifice; and the driving unit  170  for driving the wiping unit  110  and the capping unit  130  so as to situate at predetermined locations and for driving the suction unit  150 . The ink ejectability maintenance device  100  is formed into a substantially-box-shaped unit. 
     The wiping unit  110  and the capping unit  130  are disposed side by side in the main scanning direction of the print head  18 . The suction unit  150  is disposed in a side-by-side relationship with the wiping unit  110  and the capping unit  130  in the sub-scanning direction designated by arrow “b” shown in FIGS. 2 and 3. Further, the driving unit  170  is disposed so that the wiping unit  110 , the capping unit  130 , and the suction unit  150  can operate in synchronization with each other. 
     As shown in FIGS. 2,  3 , and  4 , the wiping unit  110  has a wiper  111 , a wiper holder  112 , and a wiper cleaner  113 . The wiper  111  is formed from rubber into a substantially-rectangular flat plate. The extremity of the wiper  111  rubs against the nozzle formation face of the print head  18 . As a result, the wiper  111  can wipe away the ink adhering to the nozzle formation face. The wiper  111  may be formed from felt or plastic, according to the kind of ink. 
     The wiper holder  112  is formed from plastic into the form of a substantially-rectangular plate. The wiper holder  112  holds the wiper  111  such that the extremity of the wiper  111  projects from the upper end of the wiper holder  112 . Further, the wiper holder  112  rotates in the sub-scanning direction around a partially-chipped gear  112   a  which is provided in the lower end of the wiper holder  112  and pivotally supported by a second cap holder  133  of the capping unit  130  to be described later. As a result, the wiper holder  112  can hold the wiper  111  in an upper position when the wiper  111  is used, and in a lower position when the wiper  111  is not used. 
     The wiper cleaner  113  is formed from plastic into the shape of a blade. While a guide pin  113   a  provided at an upper end of the wiper cleaner  113  is being guided along a guide groove  112   b  formed in the wiper holder  112 , the wiper cleaner  113  rotates around a lower end thereof, which is pivotally supported by the side frame  101 . An ink scraper  113   b  is provided at the upper end of the wiper cleaner  113  and assumes a U-shaped cross-sectional profile; that is, has a slit  113   s  which has substantially the same thickness as that of the wiper  111 . The ink scraper  113   b  rubs against the wiper  111  while the wiper  111  is held in the slit  113   s.    
     As mentioned above, the wiper cleaner  113  can scrape away the ink adhering to the wiper  111  without involvement of collision with the wiper  111 , by causing the wiper  111  to pass through the slit  113   s  of the ink scraper  113   b . Hence, there does not arise a faulty operation, which would otherwise be caused by noise such as collision sound. Further, the wiper  111  is not subjected to elastic deformation or restoration. Hence, there does not arise deterioration in recording accuracy, which would otherwise be caused by splashing of ink. 
     Since the width of the slit  113   s  of the ink scraper  113   b  is set so as to become substantially identical with that of the wiper  111 , the ink scraper  113   b  can clean both side surfaces of the wiper  111  where ink particularly tends to remain when the print head  18  is wiped. 
     The position of the wiper  111  for wiping operation and that of the wiper  111  for non-wiping operation are pivotally determined. During the course of pivot of the wiper  111 , the wiper  111  is arranged to pass through the slit  113   s  of the ink scraper  113   b . The wiper cleaner  113  is constructed such that the guide pin  113   a  is inserted into the guide groove  112   b  formed in the wiper holder  112  so as to follow the wiper holder  112 . The wiper cleaner  113  and the wiper  111  move in cooperation with each other. 
     Consequently, the wiper cleaner  113  can thoroughly wipe away the ink adhering to the area where interference arises between the wiper  111  and the print head  18 . After the wiper  111  has wiped the print head  18 , the wiper  111  can be cleaned at all times. 
     As shown in FIGS. 2,  3 , and  4 , the capping unit  130  is equipped with a cap  131 , a first cap holder  132 , and a second cap holder  133 . The cap  131  is formed from rubber in the form of a substantially rectangular parallelepiped. An indentation  131   a  formed in the top of the cap  131  is pressed against the nozzle formation face of the print head  18 . The capping unit  130  can seal the nozzle orifice. 
     The first cap holder  132  is formed from plastic into the shape of a substantially-rectangular-parallelepiped. An unillustrated spring is held in the second cap holder  133  while retaining the cap  131  such that the upper edge of the cap  131  projects from the upper portion of the first cap holder  132 . Projections  132   a  provided on side faces of the first cap holder  132  are engaged with claws  133   a  of the second cap holder  133 . Hence, the first cap holder  132  can move minutely in every direction. As a result, the first cap holder  132  can press the upper edge of the cap  131  against the nozzle formation face of the print head  18 . Thus, the cap  131  and the print head  18  can be brought into intimate contact with each other without fail. 
     The second cap holder  133  is formed from plastic into the shape of a substantially-rectangular-parallelepiped. The first cap holder  132  is held on the upper end face of the second cap holder  133 . While guide pins  133   b  provided on side faces of the second cap holder  133  are being guided by guide grooves  101   a ,  102   a  formed in the respective side frames  101 ,  102 , the second cap holder  133  moves vertically in conjunction with the wiper  111  and the wiper holder  112 . As a result, when the cap  131  is used, the second cap  133  can be fixedly held in an upper position. In contrast, when the cap  131  is not used, the second cap  133  can be fixedly held in a lower position. 
     The suction unit  150  is a well-known pulsation pump. Upon continuous pushing of a given portion of a tube T connected to the cap  131 , by a plurality of rollers provided at given intervals in the rotating direction, air in the tube is fed, thereby forcefully discharging ink from the print head  18  by suction. As a result, the suction unit  150  can eliminate clogging in the nozzle orifice or air bubbles intruded into ink. 
     As shown in FIGS. 2,  3 , and  4 , the driving unit  170  has a torque transmitter  171 , a switcher  172 , and an actuator  173 . The torque transmitter  171  has a first gear  171   a  provided outside of the side frame  101 , and a second gear  171   b  which is disposed integrally and coaxially with the first gear  171   a  and is interposed between the side frames  101 ,  102 . The first gear  171   a  is connected to an unillustrated motor disposed outside the side frame  101 . The second gear  171   b  is meshed with a gear  151  of the suction unit  150  shown in FIG.  2 . 
     The switcher  172  has a substantially-L-shaped switcher arm  172   a ; a forward rotation gear  172   b  rotatably attached to one end of the arm  172   a ; and a reverse rotation gear  172   c  rotatably attached to the remaining end of the same. The center of the switcher arm  172   a  is fitted into the shaft of the second gear  171   b . The switcher arm  172   a  is pressed against the second gear  171   b . Depending on the rotating direction of the second gear  171   b , either the forward rotation gear  172   b  or the reverse rotation gear  172   c  meshes with the second gear  171   b . Further, the forward rotation gear  172   b  and the reverse rotation gear  172   c  alternately mesh with a partially-chipped gear section  173   aa  of a gear-operated cam  173   a  of the actuator  173  to be described later. 
     The actuator  173  is provided with two gear-operated cams  173   a ,  173   b  provided coaxially at both side ends of the actuator  173 . The gear-operated cam  173   a  is constituted of the partially-chipped gear  173   aa  and a cam section  173   ab , which are integrated into a piece. The gear-operated cam  173   b  is constituted of a partially-chipped gear  173   ba  and a cam section  173   bb , which are integrated into a single piece. As mentioned above, the partially-chipped gear  173   aa  is arranged so as to mesh alternately with the forward rotation gear  172   b  and the reverse rotation gear  172   c  of the switcher  172 . The partially-chipped gear section  173   ba  is arranged to mesh with the partially-chipped gear  112   a  of the wiper holder  112 . The cam sections  173   ab ,  173   bb  are arranged to come into contact with lower portions of the two guide pins  133   b  disposed on both lower sides of the second cap holder  133 . 
     The torque of the motor is transmitted to the wiping unit  110  by way of the first gear  171   a , the second gear  171   b , the forward rotation gear  172   b  or the reverse rotation gear  172   c  selected as a result of pivot or rotation of the switcher arm  172   a , the partially-chipped gear  173   aa  of the gear-operated cam  173   a , and the partially-chipped gear  173   ba  of the gear-operated cam  173   b . The torque is transmitted further to the wiping unit  110  and the capping unit  130  by way of the cam section  173   ab  of the gear-operated cam  173   a  and the cam section  173   bb  of the gear-operated cam  173   b . The torque is transmitted further to suction unit  150  by way of a gear  151 . As a result, the wiping unit  110  is rotated, whereby the wiping unit  110  and the capping unit  130  are actuated vertically, thereby activating the suction unit  150 . 
     A layout relationship between the principal section of the wiping unit  110  having the foregoing configuration and the gear-operated cam  173   b  of the capping unit  130  will be described in detail by reference to FIG.  5 . Subsequently, the operation of the wiping unit  110  and that of the capping unit  130  will be described by reference to FIGS. 6 through 21. As shown in FIG. 5, a guide pin  133   b  provided on the second cap holder  133  of the capping unit  130  is inserted into a shaft hole of the partially-chipped gear  112   a  provided on the wiper holder  112  of the wiping unit  110 . 
     The gear-operated cam  173   b  is arranged such that the partially-chipped gear  173   ba  meshes with the partially-chipped gear  112   a  of the wiper holder  112  and such that the cam section  173   bb  comes into contact with the guide pin  133   b  provided on the second cap holder  133 . The wiping unit  110  pivots in the direction designated by arrow “a,” and the capping unit  130  can be vertically actuated along with the wiping unit  110  in the direction designated by arrow “b.” 
     Next, the operation of the wiping unit  110  will be described by reference to FIGS. 6 through 17. FIGS. 6 through 9, FIGS. 10 and 11, FIGS. 12 through 14, and FIGS. 15 through 17 show a single operating status when viewed from different points. More specifically, FIGS. 6 through 9 show a state in which the wiper  111  can perform a wiping operation. FIGS. 10 and 11 show a state in which the wiper  111  is in the course of being housed. FIGS. 12 through 14 show a state in which housing of the wiper  111  is completed. FIGS. 15 through 17 show a state in which the wiping unit  110  rises along with the capping unit  130 . 
     In a state in which the wiper  111  can perform a wiping operation, the wiper  111  is fixedly positioned so as to face upward, as shown in FIG.  6 . The wiper cleaner  113  is fixedly positioned to one end of the wiper holder  112 . The positioning is effected in the following manner. 
     As shown in FIGS. 6 and 8, arc-shaped portions  112   aa  and  112   ab  which have a thickness half or smaller than that of gear teeth and a radius equal to or greater than that of an addendum circle defined by the gear teeth are formed in predetermined areas extending from the respective ends of a teeth-formed section of the partially-chipped gear  112   a  provided in the wiper holder  112 . Contrary to the arc-shaped portions  112   aa ,  112   ab , arc-shaped portions  173   bc ,  173   bd  which have a thickness equal to or smaller than that of gear teeth and a radius greater than that of an addendum circle defined by the gear teeth are formed in predetermined areas extending from the respective ends of the teeth-formed section of the partially-chipped section  173   ba  provided in the gear-operated cam  173   b.    
     As shown in FIGS. 6 and 8, one arc-shaped portion  112   aa  of the partially-chipped gear  112   a  meshes with one arc-shaped portion  173   bc  of the partially-chipped gear  173   ba . The arc-shaped portion  173   bc  is sandwiched between both ends of the arc-shaped portion  112   aa : that is, between a teeth  112   ac  provided at the end of the partially-chipped gear  112   a  and a wall section  112   ad  of the arc-shaped portion  112   aa . As a result, the wiper holder  112  is positioned relative to the gear-operated cam  173   b , and hence the wiper  111  can be fixedly positioned so as to face upward. 
     As shown in FIG. 6, the guide pin  113   a  of the wiper cleaner  113  is fitted into the guide groove  112   b  formed in the wiper holder  112  shown in FIGS. 6 and 7. As a result, the wiper cleaner  113  is positioned relative to the wiper holder  112 , and hence the wiper cleaner  113  can be fixedly positioned at the end of the wiper holder  112 . 
     FIG. 9 shows the layout relationship between a guide pin  112   c  provided in the wiper holder  112  so as to act as a guide when the wiper holder  112  pivots and the guide groove  102   b  is formed in the side frame  102 . In the state at this time: that is, a state in which the wiper  111  can perform a wiping operation, the guide pin  112   c  and the guide groove  102   b  are separated from each other and remain inoperative. 
     As shown in FIG. 10, during the course of the wiper  111  being housed, the wiper holder  112  becomes inclined, whereby the wiper  111  is caught by the ink scraper  113   b  of the wiper cleaner  113 . As shown in FIGS. 10 and 11, the gear-operated cam  173   b  rotates, and the partially-chipped gear  173   ba  of the gear-operated cam  173   b  meshes with the partially-chipped gear  112   a  of the wiper holder  112 . As a result, the wiper holder  112  per se rotates, and the guide pin  113   a  of the wiper cleaner  113  is guided by the guide groove  112   b  of the wiper holder  112 . Consequently, the wiper scraper  113   b  of the wiper cleaner  113  holds and rubs against the wiper  111 . The wiper  111  can be housed while the ink adhering to the wiper  111  is being wiped away. 
     As shown in FIG. 12, when housing of the wiper  111  is completed, the wiper  111  is fixedly positioned so as to face a downwardly slanting direction. The wiper cleaner  113  is fixedly positioned on the upper end of the wiper holder  112 . The positioning of the wiper cleaner  113  is effected by the following operation. 
     In a state in which the wiper  111  is housed as shown in FIGS. 12 and 13, when an attempt is made to move the wiper  111  in a setting direction (to the wiping position), a tooth  112   ae  provided at the end of the partially-chipped gear  112   a  comes into collision with the arc-shaped portion  173   bd  of the partially-chipped gear  173   ba  of the gear-operated cam  173   b . Hence, the wiper  111  cannot be moved in the setting direction. 
     In a state as shown in FIG. 14, when an attempt is made to move the wiper  111  in a resetting direction as indicated by arrows in this figure, the guide pin  112   c  of the holder  112  comes into collision with the wall of the guide groove  102   a  of the side frame  102  (the left wall in this figure). Hence, the wiper  111  cannot be moved in the resetting direction. As a result, the wiper holder  112  is positioned relative to the gear-operated cam  173   b  and the side frame  102 . Hence, the wiper  111  can be fixedly positioned so as to face a downwardly slanting direction. 
     As shown in FIG. 12, the guide pin  113   a  of the wiper cleaner  113  is positioned at the upper end of the guide groove  112   b  of the wiper holder  112 . Therefore, the wiper cleaner  113  can be fixedly positioned relative to the wiper holder  112 . 
     Finally, when the wiping unit  110  has risen along with the capping unit  130 , the wiper  111  is fixedly positioned while being oriented in a downwardly slanting direction and spaced apart from the gear-operated cam  173   b . The wiper cleaner  113  is fixedly positioned on the upper end of the wiper holder  112 . Fixed positioning of the wiper cleaner  113  is effected by the following operation. 
     As shown in FIG. 17, as a result of rotation of the gear-operated cams  173   a ,  173   b , the cam sections  173   ab ,  173   bb  of the gear-operated cams  173   a ,  173   b  raise the guide pins  133   b  of the second cap holder  133  along the guide grooves  101   a ,  102   a.    
     As shown in FIG. 17, the guide pin  112   c  of the wiper holder  112  enters a vertical portion of the guide groove  102   a  of the side frame  102 . As a result, the wiper holder  112  is positioned relative to the gear-operated cams  173   a ,  173   b  and the side frame  102 . Hence, the wiper  111  can be fixedly positioned while being oriented to a downward slanting direction and spaced apart from the gear-operated cams  173   a ,  173   b.    
     On the other hand, as shown in FIG. 15, the guide pin  113   a  of the wiper cleaner  113  has been moved to the upper end of the guide groove  112   b  of the wiper holder  112  so that the wiper cleaner  113  is fixedly positioned relative to the wiper holder  112 . 
     The operation of the capping unit  130  will now be described by reference to FIGS. 18 through 21. FIGS. 18,  19  and FIGS. 20,  21  show a single operating status from different view points. More specifically, FIGS. 18,  19  show completion of housing of the cap  131 , and FIGS. 20,  21  show a state in which the cap  131  can perform a capping operation. 
     As shown in FIGS. 18 and 19, the capping unit  130  is fixedly positioned on the lowermost end of the cap  131 . Positioning of the capping unit  130  is performed by the following operation. As shown in FIG. 18, the partially-chipped gear section  173   aa  of the gear-operated cam  173   a  is arranged such that the forward rotation gear  172   b  and the reverse rotation gear  172   c  alternately mesh with a position on the partially-chipped gear section  173   aa  offset in the widthwise direction thereof, by pivot of the switcher arm  172   a . Two tooth-chipped sections  173   ac ,  173   ad  are formed on the partially-chipped gear  173   aa  so as to become spaced apart from each other in both circumferential and widthwise directions thereof. 
     As shown in FIGS. 18 and 19, cam sections  173   ab ,  173   bb  of the gear-operated cams  173   a ,  173   b  are formed into substantially the shape of an oval. A stopper  173   ae  capable of coming into contact with one of the two guide pins  133   b ,  133   b  provided on the respective lower sides of the second cap holder  133  is provided at any point on the cam section  173   ab . Similarly, a stopper  173   be  capable of coming into contact with the remaining guide pin  133   b  is provided at any point on the cam section  173   bb . Further, a guide groove  173   af  is formed in the side face of the cam  173   a , wherein one of the two other guide pins  133   c ,  133   c  provided on the second cap holder  133  is guided along the outer periphery of one of the two other guide pins  133   c ,  133   c  provided in the second cap holder  133 . 
     When the capping unit  130  has reached the lowermost end from the uppermost end, a guide groove  173   af  of a cam section  173   ab  of the gear-operated cam  173   a  and a guide groove  173   bf  of a cam section  173   bb  of the gear-operated cam  173   b  move the two guide pins  133   c  of the second cap holder  133 . The two guide pins  133   b  provided on both lower portions of the second cap holder  133  are pushed down to the lowermost end along the guide groove  101   a  of the side frame  202  and the guide groove  102   a  of the side frame  102 . 
     The reverse rotation gear  172   c  runs idle while meshing with the tooth-chipped section  173   ad  of the partially-chipped gear  173   aa  of the gear-operated cam  173   a . As a result, the second cap holder  133  is fixedly positioned relative to the side frames  101 ,  102  of the gear-operated cams  173   a ,  173   b . Hence, the capping unit  130  can be fixedly positioned at the lowermost end. 
     In a state in which the cap  131  can perform a capping operation, the capping  130  is fixedly position at the uppermost end location, as shown in FIGS. 20 and 21. When the capping unit  130  has reached the highest position from the lowermost position, the cam section  173   ab  of the gear-operated cam  173   a  and the cam section  173   bb  of the gear-operated cam  173   b  move the two guide pins  133   d ,  133   e  of the second cap holder  133 . Then, the two guide pins  133   b  provided on both sides of the second cap holder  133  are raised to the uppermost end potions so as to come into contact with the stoppers  173   ae ,  173   be  along the guide groove  101   a  of the side frame  101  and the guide groove  102   b  of the side frame  102 . 
     The forward rotation gear  173   b  runs idle while meshing with the teeth-lacking section  173   ac  of the partially-chipped gear  173   aa  of the gear-operated cam  173   a . As a result, the second cap holder  133  is positioned relative to the gear-operated cams  173   a ,  173   b  and the side frames  101 ,  102 . Hence, the capping unit  130  can be fixedly positioned on the uppermost end location. 
     The entire operation of the ink ejectability maintenance device  100  equipped with the wiping unit  110 , the capping unit  130 , the suction unit  150 , and the driving unit  170 , which have been described above, will now be described by reference to FIGS. 22 through 31. FIG. 22 is a timing chart showing an example of operation of the ink ejectability maintenance device  100 . FIGS. 23 through 25, FIGS. 26 through 28, and FIGS. 29 through 31 show a single operating status from different view points. More specifically, FIGS. 23 through 25 show a state in which the wiper  111  can perform a wiping operation; FIGS. 26 through 28 show a state in which housing of the wiper  111  has been completed; and FIGS. 29 through 31 show a state in which the cap  131  can perform a capping operation. 
     As shown in FIGS. 23 through 25, when the motor rotates forwardly in the manner as shown in FIG. 22, the capping unit  130  is situated in the lowermost end position. The cap  131  is in an “open” state: that is, an uncapped state. Moreover, the wiping unit  110  is situated in a higher position. The wiper  111  remains in a “set” state: that is, a wipe-enable state. The roller of the pump: that is, the suction unit  150 , remains in a “released” state with respect to a tube, i.e., a non-sucking state (point in start time t 1 ). 
     When in this state the motor is driven in a forward rotation (CW), to thereby rotate the first gear  171   a  and the second gear  171   b , the switcher arm  172   a  rotates, whereupon the forward rotation gear  173   b  meshes with the partially-chipped gear section  173   aa  of the gear-operated cam  173   a . The torque of the second gear  171   b  is transmitted from the forward rotation gear  172   b  to the tooth-chipped gear  173   aa  of the gear-operated cam  173   a , and the gear-operated cams  173   a ,  173   b  rotate. Subsequently, the tooth-chipped gear section  173   ba  of the gear-operated cam  173   b  meshes with the tooth-chipped gear  112   a  of the wiper holder  112 , and then the wiper holder  112  starts rotating (point in time t 4 ). 
     When the tooth-chipped section  173   b  of the gear-operated cam  173   b  becomes disengaged from the tooth-chipped gear  112   a  of the wiper holder  112 , the wiper holder  112  stops rotating. As shown in FIGS. 26 through 28, the wiping unit  110  is situated in a lower position, and the wiper  111  remains in a “reset-low” state: that is, a state in which the wiper  111  is housed (point in time t 5 ). 
     When the gear-operated cams  173   a ,  173   b  rotate, the capping unit  130  starts rising along with the wiping unit  110  by action of the cam section  173   ab  of the gear-operated cam  173   a  and the cam section  173   bb  of the gear-operated cam  173   b  (point in time t 6 ). When the forward rotation gear  172   b  has reached a tooth-chipped section  173   ac  of a tooth-chipped gear section  173   aa  of the gear-operated cam  173   a , the forward rotation gear  172   b  runs idle. Hence, the capping unit  130  and the wiping unit  110  stop rising. 
     As shown in FIGS. 29 through 31, in this state, the capping unit  130  is situated in the uppermost end position, and the cap  131  remains in a “closed” state: that is, a capping state. The wiping unit  110  is situated in a position higher than the previous position. The wiper  111  remains in a “reset-high” state: that is a state in which the wiper  111  remains elevated while being housed (point in time t 7 ). 
     When in this state the motor has rotated forwardly further, to thereby rotate the first gear  171   a  and the second gear  171   b , the suction unit  150  is activated. At this time, the roller of the pump has bitten at the tube. In other words, the roller of the pump is in an aspirating state (points in time t 8 , t 9 ). Torque is not transmitted to the pump while the wiping unit  110  and the capping unit  130  are in operation. 
     When the motor rotates reversely (CCW) in the manner as shown in FIG. 22, the capping unit  130  and the wiping unit  110  operate in a manner reverse to that mentioned above. When the gear  151  shown in FIG. 2 rotates half, the claw of the gear  151  pushes the claw of a disk  152 , whereupon the disk  152  starts rotating. In the meantime, the wiping unit  110  and the capping unit  130  have completed operation. Here, the suction unit  150  returns to a “released” state in points of time t 3 , t 4 . 
     As has been described, the ink ejectability maintenance device  100  of the embodiment is provided with the members  112   a ,  112   b ,  113   a ,  173   a ,  173   b ,  112   c , and  102   b  for effecting positional guiding and fixing operation when the wiping unit  110  is positioned, and the members  133   b ,  101   a ,  102   a ,  173   a , and  173   b  for effecting positional guiding and fixing operations when the capping unit  130  is positioned. 
     As a result, the wiping unit  110  and the capping unit  130  can be held in constant positions. Provided that the user has touched the wiping unit  110  or the capping unit  130 , they are caused no positional displacement. Consequently, there is obviated an operation for returning the wiping unit  110  and the capping unit  130  to predetermined positions. Further, there is prevented occurrence of damage, which would otherwise be caused when components constituting the wiping unit  110  and the capping unit  130  come into collision with each other, thereby facilitating maintenance. 
     The wiping unit  110  and the capping unit  130  can be positioned very accurately at all times. Hence, at the time of assembly of the head ejecting maintenance characteristic device  100 , there is obviated an operation for causing components constituting the wiping unit  110  and the capping unit  130  to match in phase with each other. 
     The embodiment has described the head ejecting maintenance characteristic device  100  having one capping unit  130  and one suction unit  150 . However, the invention is not limited to this embodiment. For instance, as shown in FIG. 32, an ink ejectability maintenance device  200  having two capping unit  130  and two suction unit  150  can be constructed in the same manner and can yield the same effect as that attained by the device  100 .