Patent Publication Number: US-8118399-B2

Title: Ink receiving unit and inkjet printer including the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority to Japanese Patent Application No. 2007-327615, filed on Dec. 19, 2007, the entire contents of which are herein incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an ink receiving unit and an inkjet printer including the ink receiving unit. 
     2. Discussion of the Background 
     Recently, inkjet printers for printing on a variety of materials as media other than paper have been developed. For example, an inkjet printer capable of printing on a mesh-like medium or a fibrous medium has been developed. 
     Mesh-like media and fibrous media have coarse texture as compared to paper. Therefore, if printing is conducted on such a medium by an inkjet printer, the medium allows ink ejected onto the surface thereof to seep through the medium to the back side of the medium. As the ink seeps through to the back of the medium, the ink may be deposited on the printing apparatus, causing contamination of medium. Therefore, in case of printing on the aforementioned medium, it is essential to takes measures to cope with ink droplets dripping from the back of the medium. 
     As an example of a coping method, such a method is conceivable to dispose a gutter-like ink receiver for receiving ink droplets dripping from the back of the medium. In this method, the ink receiver may be arranged below the inkjet head to have a slant. The slant lets the ink dripping from the medium flow under its own weight to remove (run off) the ink. Further, such a method is also conceivable to dispose a sponge for absorbing the ink on the gutter of the ink receiver and to replace suitably the sponge with new one. 
     However, it is difficult to remove all ink only by using the gutter-like receiver having a slant. Ink may remain on the ink receiver and become solidified. Further, if the solidified ink is stacked and/or blocks the flow of ink, the back of the medium may be contaminated by ink remaining on the ink receiver. If the medium is contaminated, the image quality on the medium is degraded, thus spoiling the medium. 
     In case of disposing the sponge for absorbing the ink, the timing for replacement depends on the frequency of use of machine. Since the absorption property of the sponge deteriorates due to ink fixated to the sponge, it is inconvenient. 
     Due to the aforementioned problems, these methods require considerable labor for periodical manual maintenance. Accordingly, there is a demand to provide a more suitable method for handling ink dripping from the back of the medium. Therefore, there is a need to provide an ink receiving unit and a printing apparatus capable of solving the aforementioned problems. 
     Conventionally, for example, there is known an arrangement of an inkjet printer addressing the object of quickly and reliably collecting waste ink without contaminating the circumference (for example, see JP-A-H11-48498). However, this arrangement relates to collection of waste ink during maintenance conducted by discharging the ink from each nozzle at the time of non-printing. Further, the collection of waste ink is conducted at a place out of the printing range where the printing is conducted on media. That is, the arrangement is not capable of suitably collecting ink dripping from the back of the medium during printing. Therefore, the aforementioned problems cannot be solved even using this arrangement. The contents of JP-A-H11-48498 are incorporated herein by reference in their entirety. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the present invention, an ink receiving unit for an inkjet printer includes an ink receiver and an ink removing device. The inkjet printer has an inkjet head configured to eject ink onto a first surface of a medium. The ink receiver is provided to face the inkjet head via the medium. The ink receiver is configured to receive ink dripping from a second surface opposite to the first surface of the medium during printing. The ink removing device is configured to remove the ink from the ink receiver. The ink receiver unit is detachably mounted to a main body to which the inkjet head is mounted. 
     According to another aspect of the present invention, an inkjet printer includes a main body, an inkjet head, and an ink receiving unit. The inkjet head is mounted to the main body and configured to eject ink onto a first surface of a medium. The ink receiving unit includes an ink receiver and an ink removing device. The ink receiver is detachably mounted to the main body and provided to face the inkjet head via the medium. The ink receiver is configured to receive ink dripping from a second surface opposite to the first surface of the medium during printing. The ink removing device is configured to remove the ink from said ink receiver. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete appreciation of the invention and many of the attendant advantages thereof will become readily apparent with reference to the following detailed description, particularly when considered in conjunction with the accompanying drawings, in which: 
         FIG. 1  is an illustration of a main body of a printing apparatus  10  according to an embodiment of the present invention; 
         FIG. 2  is an illustration showing an attaching state that an ink receiving unit  14  is attached to a main body  12  of the printing apparatus  10 ; 
         FIGS. 3(   a ) and  3   b ) are enlarged views of attached portions of the ink receiving unit  14 , where  FIG. 3(   a ) is an enlarged view of one end side of the ink receiving unit  14 , and  FIG. 3(   b ) is an enlarged view of the other end side of the ink receiving unit  14 ; 
         FIGS. 4(   a ) and  4 ( b ) are illustrations showing a first example of specific structure of the ink receiving unit  14 , where  FIG. 4(   a ) shows the structure of one end side of the ink receiving unit  14 , and  FIG. 4(   b ) shows the structure of the other side of the ink receiving unit  14 ; 
         FIG. 5  is a perspective view of an upper side of the ink receiver  102  as seen diagonally from rear left; 
         FIG. 6  is a perspective view of a bottom side of the ink receiver  102  as seen diagonally from front right; 
         FIGS. 7(   a ) and  7 ( b ) are illustrations showing a second example of specific structure of the ink receiving unit  14 , where  FIG. 7(   a ) shows the structure of one end side of the ink receiving unit  14 , and  FIG. 7(   b ) shows the structure of the other end side of the ink receiving unit  14 ; and 
         FIGS. 8(   a ) and  8 ( b ) are illustrations schematically showing a variation of the structure of the ink receiving unit  14 , where  FIG. 8(   a ) is a top view of the ink receiving unit  14 , and  FIG. 8(   b ) is a sectional side view of the ink receiving unit  14 . 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION 
     Embodiments of the present invention will be described hereinafter with reference to the accompanying drawings. In the following description, the constituent elements having substantially the same function and arrangement are denoted by the same reference numerals, and repetitive descriptions will be made only when necessary. The embodiments of the present invention have the following arrangements. 
     In a first arrangement, an ink receiving unit is provided which is used in a printing apparatus for printing in accordance with an inkjet method and which is detachably mounted to a main body provided with an inkjet head. The ink receiving unit includes an ink receiver which is arranged at a position facing the inkjet head across a medium during printing to receive ink dripping from the back of the medium, and an ink removing means for removing the ink in the ink receiver from the ink receiver. 
     The ink receiving unit is mounted, for example, in case of printing on a medium through which ink ejected onto the surface of the medium is allowed to seep to the back side of the medium. The medium through which ink ejected onto the surface of the medium is allowed to seep to the back side of the medium is, for example, a medium allowing ink ejected from an inkjet head to drip from the back thereof. Examples of such media include mesh-like media and fibrous media. 
     According to this arrangement, it is possible to suitably receive the ink dripping from the back of the medium. By using the ink removing means, the ink received by the ink receiver can be suitably removed. Therefore, it is possible to suitably prevent the ink in the ink receiver from being stacked or solidified. Since the ink receiver can be automatically cleaned by operation of the ink removing means, the time and labor for periodical manual maintenance can be significantly reduced, thereby suitably reducing the cleaning time and labor for manually cleaning the ink receiver. As compared to a case of using a sponge or the like for absorbing the ink, it is not required to exchange the sponge or the like. 
     In this arrangement, since the arrangement for receiving ink is structured as a unit, the ink receiving unit can be used according to the user&#39;s need. For example, in case of printing on a medium such as a mesh-like medium or a fibrous medium, the ink receiving unit is used. On the other hand, in case of printing on a medium such as non mesh-like medium, the ink receiving unit is not used. The non mesh-like medium is, for example, a medium not allowing ink ejected on the surface of thereof to drip from the back thereof. In case of printing on a medium such as non mesh-like medium, for example, a platen unit is mounted after the ink receiving unit is detached. Therefore, according to this arrangement, the printing apparatus can handle different kinds of media by changing the unit according to the kind of medium. 
     The ink removing means removes ink in real time, for example, during the printing operation. In this case, for example, the ink removing means preferably operates always at the same time of the printing operation. Further, the ink removing means may start the operation for removing ink in response to the depression of the button or the like during the maintenance of the printing apparatus, for example. 
     The ink removing means may remove ink, for example, when the printer apparatus is in stand-by state (sleeping state). According to this arrangement, it is possible to suitably prevent the solidification of residual ink in an unattended environment, i.e. without any user. 
     In a second arrangement, the printing apparatus is a printing apparatus of a scanning type in which the printing is conducted while reciprocating the inkjet head in a previously set main scanning direction, the ink receiver is a gutter-like member extending in the main scanning direction, the ink removing means is a wiper member which is slidable along the gutter-like ink receiver and is adapted to remove the ink in the ink receiver by traveling within the ink receiver in the main scanning direction, the main body has a driving motor for producing power for driving the wiper member, the ink receiving unit further includes a wire for moving the wiper member, which is connected to the wiper member and is tensioned to extend in the longitudinal direction of the ink receiver, and a wire drum on which the wire is wound and which moves the wire according to the output power of the driving motor, and in a state that the ink receiving unit is mounted to the main body, the rotary shaft of the driving motor and the rotary shaft of the wire drum extend parallel to a sub scanning direction perpendicular to the main scanning direction. For example, the main body further includes a train of idler gears connecting from the driving motor to the wire drum. In addition, the ink receiving unit may include a train of idler gears. The ink receiving unit is mounted to the main body by pushing the ink receiving unit into the main body in a linear manner from the front side of the main body. 
     According to this arrangement, the gutter-like ink receiver which is small in the width direction is used, thereby suitably reducing the size of the ink receiver. In addition, the wiper member is used as the ink removing means, thereby suitably removing the ink in the ink receiver. 
     According to this arrangement, the rotary shafts of the driving motor and the wire drum are arranged to extend parallel to each other. Therefore, the power of the driving motor can be reliably transmitted to the wire drum by a simple structure. The sub scanning direction which is parallel to the rotary shafts is parallel to a direction extending from the front surface to the back surface of the main body, for example. According to this arrangement, for example, the rotary shafts of the driving motor and the wire drum can be meshed with each other by pushing the ink receiving unit into the main body in a linear manner from the front side of the main body. Therefore, this arrangement facilitates the mounting of the ink receiving unit, for example. It should be noted that the rotary shafts of the driving motor and the wire drum may be meshed via another gear between them. 
     In a third arrangement, the printing apparatus is a printing apparatus of a scanning type in which the printing is conducted while reciprocating the inkjet head in a previously set main scanning direction, the ink receiver is a gutter-like member extending in the main scanning direction, the ink removing means is a wiper member which is slidable along the gutter-like ink receiver and is adapted to remove the ink in the ink receiver by traveling within the ink receiver in the main scanning direction, the main body has a driving motor for producing power for driving the wiper member, the ink receiving unit further includes a wire for moving the wiper member, which is connected to the wiper member and is tensioned to extend in the longitudinal direction of the ink receiver, and a wire drum, on which the wire is wound and which moves the wire according to the output power of the driving motor, and in a state that the ink receiving unit is mounted to the main body, the rotary shaft of the wire drum extends parallel to a sub scanning direction perpendicular to the main scanning direction and the rotary shaft of the driving motor extends parallel to the main scanning direction. For example, the main body further includes a train of idler gears connecting from the driving motor to the wire drum. In addition, the ink receiving unit may include a train of idler gears. 
     According to this arrangement, the gutter-like ink receiver which is small in the width direction is used, thereby suitably reducing the size of the ink receiver. In addition, the wiper member is used as the ink removing means, thereby suitably removing the ink in the ink receiver. 
     According to this arrangement, the rotary shaft of the driving motor extends parallel to the main scanning direction, thereby allowing the driving motor to be located at a position adjacent to the ink receiving unit in the main scanning direction, for example. This arrangement can achieve reduction of size in the depth direction, i.e. the sub scanning direction, required for installation of the ink receiving unit in the main body. Further, this arrangement can prevent the printing apparatus from growing in size, for example. 
     In the aforementioned second and third arrangements, the sub scanning direction is a direction perpendicular to the main scanning direction in a plane parallel to the medium. The driving motor of the main body cooperate together with the wire drum of the ink receiving unit and the like to compose a driving section for driving the wiper member. The driving section may include another gear(s) and the like between the driving motor and the wire drum. 
     The ink receiver spreads in a wide area larger than the width of the medium in the main scanning direction, for example. According to this arrangement, ink droplets are suitably received. The printing apparatus is preferably a printing apparatus of a paper-moving type in which the printing is conducted while feeding a medium in a sub scanning direction perpendicular to the main scanning direction. According to this arrangement, it is not required to move the ink receiver so that ink can be suitably received. 
     In a fourth arrangement, a printing apparatus for printing in accordance with the inkjet method includes a main body which is provided with an inkjet head, and an ink receiving unit as described in any one of the first, second, or third arrangements. According to this arrangement, the same effects as those of the first, second, and third arrangements can be obtained. 
     In a fifth arrangement, the printing apparatus is a printing apparatus of a scanning type in which the printing is conducted while reciprocating the inkjet head in a previously set main scanning direction, the ink receiver is a gutter-like member extending in the main scanning direction, the ink removing means is a wiper member which is slidable along the gutter-like ink receiver and is adapted to remove the ink in the ink receiver by traveling within the ink receiver in the main scanning direction, the printing apparatus further includes a controller for controlling the operation of the wiper member in the main scanning direction and the controller changes the stand-by position of the wiper member for every operation in which the wiper member travels a predetermined amount, the stand-by position being a position within the ink receiver where the wiper member stands by when it is not in operation. 
     As the ink is removed by the wiper member, the ink adheres to the wiper member. Accordingly, as the wiper member is stopped after removal of ink, the ink directly below the wiper member may be solidified at the stand-by position where the wiper member is stopped. If the wiper member is stopped at the same position every time, the solidified ink may be stacked at the position by the repetition of the traveling and stopping of the wiper member. The stacked solidified ink may contaminate the back of the medium and further may block the operation of the wiper member. 
     According to the fifth arrangement, however, even though the ink directly below the wiper member is solidified, the stand-by position of the wiper member is suitably changed, thereby distributing the position where ink is solidified. Therefore, it is possible to suitably prevent the problem caused due to stacking of solidified ink. 
     It should be noted that the operation of the wiper member of traveling a predetermined amount means that the wiper member conducts reciprocation traveling within the ink receiver for a predetermined number of times or more or for a predetermined period of time or more. The controller may change the stand-by position of the wiper member for every a predetermined number of times of the stand-by of the wiper member. For example, the controller may change the stand-by position of the wiper member definitely every operation. In case of changing the stand-by position of the wiper member, the controller may change the stand-by position within the operation range of the wiper member in a random manner, for example. 
     According to an embodiment of the present invention, ink droplets dripping from the back of the medium is received by the ink receiver and is suitably removed. This arrangement also suitably reduces the cleaning time and labor for manually cleaning the ink receiver, for example. 
     Hereinafter, embodiments according to the present invention will be described with reference to the drawings.  FIG. 1  though  FIG. 3(   b ) show an example of arrangement of printing apparatus  10  according to an embodiment of the present invention.  FIG. 1  shows appearance of a main body of the printing apparatus  10 .  FIG. 2  shows an attaching state that an ink receiving unit  14  is attached to the main body  12  of the printing apparatus  10 .  FIGS. 3(   a ) and  3 ( b ) are enlarged views of attached portions of the ink receiving unit  14 .  FIG. 3(   a ) is an enlarged view of one end side of the ink receiving unit  14 .  FIG. 3(   b ) is an enlarged view of the other end side of the ink receiving unit  14 . 
     The printing apparatus  10  is an inkjet printer of a scanning type in which the printing is conducted while reciprocating an inkjet head thereof in a previously set main scanning direction. The printing apparatus  10  is a printing apparatus of a paper-moving type in which the printing is conducted while feeding a medium in a sub scanning direction perpendicular to the main scanning direction. Further, in this embodiment, the printing apparatus  10  is a printing apparatus for printing on a medium through which ink ejected onto the surface of the medium is allowed to seep to the back side of the medium and includes a main body  12  and an ink receiving unit  14 . The medium through which ink ejected onto the surface of the medium is allowed to seep to the back side of the medium is a medium allowing ink ejected from an inkjet head to drip from the back thereof, for example, mesh-like media and fibrous media. 
     The main body  12  is a main portion of the printing apparatus  10  for printing on the medium. In this embodiment, the ink receiving unit  14  is attached to the main body  12 . The main body  12  has an inkjet head  16  and a controller  18  therein. The inkjet head  16  is a print head for ejecting ink in accordance with the inkjet method. The controller  18  is a control device such as a CPU for controlling respective components of the printing apparatus  10 . Though only some components have been described in the above for ease of explanation, the main body  12  suitably comprises components required for printing, such as a feeding unit for feeding media. 
     The ink receiving unit  14  is a member for receiving ink droplets dripping from the back of the medium and is detachably attached to the main body  12 . In this embodiment, the ink receiving unit  14  is mounted such that the longitudinal direction thereof extends parallel to the main scanning direction. At least during printing, an ink receiver which receives ink droplets in the ink receiving unit  14  faces the inkjet head  16  across a medium. The ink receiver spreads in a wide area larger than the width of the medium in the main scanning direction. According to this embodiment, ink droplets dripping from the back of the medium can be suitably received. 
     In this embodiment, the arrangement for receiving ink droplets dripping from the back of the medium is structured as a unit which is detachably attached to the main body  12 , i.e. the ink receiving unit  14 . Since the ink receiving unit  14  is separated from the main body  12 , the ink receiving unit  14  can be used when it is necessary according to the kind of media or the like. For example, in case of printing on a medium such as a mesh-like medium or a fibrous medium, the ink receiving unit  14  is used. On the other hand, in case of printing on a medium such as non mesh-like medium, the ink receiving unit  14  is not used. Therefore, according to this embodiment, the printing apparatus  10  can handle different kinds of media. 
     In the state shown in  FIG. 3(   b ), the inkjet head  16  stands by at a position outside of the ink receiving unit  14 . However, during printing, the inkjet head  16  reciprocates in the main scanning direction. Accordingly, during printing, the ink receiver of the ink receiving unit  14  and the inkjet head  16  face each other across the medium. The distance between the inkjet head  16  and the ink receiver is in a range of from 3 to 10 mm, for example, and more preferably from 5 to 7 mm. According to this structure, ink droplets dripping from the back of the medium can be suitably received with the medium laying between the inkjet head  16  and the ink receiver. 
       FIGS. 4(   a ) and  4 ( b ) show a first example of specific structure of the ink receiving unit  14 .  FIG. 4(   a ) shows the structure of one end side of the ink receiving unit  14  as well as some parts of the main body  12  (see  FIG. 1) .  FIG. 4(   b ) shows the structure of the other side of the ink receiving unit  14 . 
     In this example, the ink receiving unit  14  has an ink receiver  102 , a wiper member  104 , and some parts composing a driving section  106 . The ink receiver  102  is a gutter-like waste ink tray for receiving ink droplets dripping from the back of the medium. In the example, the ink receiver  102  extends in the main scanning direction when the ink receiving unit  14  is attached to the main body  12 . Formed on one end of the ink receiver  102  is an ink discharge port  202 . The ink discharge port  202  is an opening for discharging waste ink received by the ink receiver  102  to the outside. The ink discharge port  202  is connected to a discharge passage  204  formed in the main body  12  so that waste ink is discharged by flowing the waste ink through the discharge passage  204 . 
     In this example, the ink discharge port  202  is formed at the end, near the driving section  106 , of the ink receiver  102 . Accordingly, the ink receiving unit  14  collects waste ink by moving the wiper member  104  in a direction toward the driving section  106 . Another ink discharge port  202  may also be formed at the end, far from the driving section  106 , of the ink receiver  102 . With this structure, waste ink can be also collected by moving the wiper member  104  in a direction apart from the driving section  106 . 
     The wiper member  104  is an example of ink removing means for removing the ink in the ink receiver  102  from the ink receiver  102 . In this example, the wiper member  104  slides in the main scanning direction corresponding to the longitudinal direction of the ink receiver  102 . The wiper member  104  removes the ink in the ink receiver  102  by sliding and traveling along the gutter-like ink receiver  102 . Therefore, the wiper member  104  functions as a waste ink wiper to clean the ink receiver  102  by forcibly removing the ink in the ink receiver  102 . In this manner, this example can suitably remove the ink in the ink receiver  102 . 
     In this example, the wiper member  104  has a substantially T-like shape and has a widespread portion  302  extending in the width direction of a gutter-like groove of the ink receiver  102  and a wire connecting portion  304  projecting from the center of the widespread portion toward one end of the ink receiver  102 . The widespread portion  302  is a portion corresponding to a head portion of the character T and has a structure of spreading in the width direction of the ink receiver  102  so as to enable the widespread portion  302  to push out the ink in the ink receiver  102  according to the sliding of the wiper member  104 . The wire connecting portion  304  is a portion corresponding to a leg portion of the character T and is connected to a wire  108  for driving the wiper member  104 . Therefore, the wiper member  104  is moved along the ink receiver  102  when subjected to force of the driving section  106  through the wire  108 . 
     The driving section  106  has a motor, gears, and the like for driving the wiper member  104 . In this example, the driving section  106  has a driving motor  206  and a wire drum  208 . The driving motor  206  rotates the wire drum  208  according to a command from the controller  18 . The wire drum  208  is a drum on which the wire  108  is wound and moves the wire  108  according to the output power of the driving motor  206 . Therefore, the driving section  106  drives the wiper member  104  via the wire  108  according to the command of the controller  18 . 
     In this example, the driving section  106  also comprises gears and/or pulleys, for example. The driving section  106  is structured by combining respective components on the main body  12  and the ink receiving unit  14 . Specific structure of the driving section  106  will be further described later in detail. 
     The wire  108  is a driving wire transmitting the power of the driving section  106  to the wiper member  104 . In this example, the wire  108  is tensioned to extend in the longitudinal direction of the ink receiver  102  by pulleys of the driving section  106  in the ink receiver  102 . 
     In this example, the wire  108  is tensioned to extend to make a round trip (loop) in the ink receiver  102  by and between the wire drum  208  and the pulley, disposed on one end side of the ink receiving unit  104 , of the driving section  106  and a plurality of pulleys, disposed on the other end side of the ink receiving unit  104 , of the driving section  106 . A part corresponding to one way of the round trip of the wire  108  is tensioned to extend along the center in the width direction of the ink receiver  102 . The wire connecting portion  304  of the wiper member  104  is attached to the part of the wire extending along the center. Thus, the wire  108  holds the T-like wiper member  104  at the center of the wiper member  104  (center holding). When the wiper member  104  is held at its center, the wiper member  104  is held at its center of gravity so that the wiper member  104  does not practically rattle and the wiper member  104  can stably travel. 
     As a method for holding the wiper member  104  using the wire  108 , there is conceivable a method of holding one side of the wiper member  104  (cantilever holding) instead of center holding. However, the cantilever holding makes the wiper member  104  more easily rattle so that it may be difficult to drive the wiper  104  to stably travel. As measures for preventing the rattling are taken, the apparatus may be increased in size and in cost. Further, the workability may become worse. However, according to this example, the wiper member  104  is held at the center, thereby driving the wiper member  104  to stably travel without increasing the size of the apparatus. 
     As mentioned above, according to this example, ink received by the ink receiver  102  can be suitably removed by the wiper member  104 . Therefore, it is possible to suitably prevent the ink in the ink receiver  102  from being stacked or solidified. Since the ink receiver  102  can be automatically cleaned by movement of the wiper member  104 , the cleaning time and labor for manually cleaning the ink receiver  102  can be suitably reduced. Moreover, it is possible to conduct the collection of waste ink all over the printing area at a side behind the medium, thereby removing the waste ink at the same time of printing, for example. Therefore, stacking and solidification of ink can be suitably prevented. 
     Hereinafter, the control of movement of the wiper member  104  by the controller  18  will be further described in detail. In this example, the controller  18  controls the wiper member  104  to operate, for example, when the printing apparatus  10  (see  FIG. 1 ) conducts printing operation. Accordingly, the wiper member  104  removes ink in real time during the printing operation. 
     The controller  18  may control the wiper member  104  to operate in response to depression of a button or the like during maintenance of the printing apparatus, for example. In this case, the depression of the button or the like makes the wiper member  104  start to remove ink. The controller  18  may control the wiper member  104  to operate at regular time intervals for example when the printer apparatus is in stand-by state (sleeping state). Accordingly, it is possible to suitably prevent the solidification of residual ink in an unattended environment, i.e. without any user. 
     In this example, the controller  18  changes the stand-by position of the wiper member  104  for every operation in which the wiper member  104  travels a predetermined amount. The stand-by position of the wiper member  104  is a position within the ink receiver where the wiper member  104  stands by when it is not in operation. For example, the controller  18  changes the stand-by position in a random manner every time when stopping the wiper member  104  after the operation. 
     When the wiper member  104  is stopped to stand by, ink adhering to a portion directly below the wiper member  104  may be solidified in the stand-by position. According to this example, however, even though the ink adhering to a portion directly below the wiper member  104  is solidified, the position where ink is solidified is distributable. Therefore, it is possible to suitably prevent the problem caused due to stacking of solidified ink. Further, it is therefore possible to suitably remove waste ink. 
       FIG. 5  and  FIG. 6  are perspective views schematically showing an example of specific structure of the driving section  106  with the ink receiver  102 , the wiper member  104 , and the wire  108 .  FIG. 5  is a perspective view of an upper side of the ink receiver  102  as seen diagonally from rear left.  FIG. 6  is a perspective view of a bottom side of the ink receiver  102  as seen diagonally from front right. 
     In this example, the driving section  106  includes a driving motor  206 , a motor pinion gear  305 , a drive gear  311 , a power transmitting shaft  308 , a drive gear  312 , a motor timing control fin  315 , a torque limiter  309 , a motor control photosensor  314 , two idler gears  313 , a drum drive gear  307 , a drum shaft  306 , a wire drum  208 , pulleys  310 , a turn-around pulley  106   a , and turn-around pulleys  106   b.    
     Among them, the driving motor  206 , the motor pinion gear  305 , the drive gear  311 , the power transmitting shaft  308 , the drive gear  312 , the motor timing control fin  315 , the torque limiter  309 , the motor control photosensor  314 , and the two idler gears  313  are disposed on the main body  12  (see  FIG. 1 ). The drum drive gear  307 , the drum shaft  306 , the wire drum  208 , the pulleys  310 , the turn-around pulley  106   a , and the turn-around pulleys  106   b  are disposed on the ink receiving unit  14 . These components other than the turn-around pulley  106   a  and the turn-around pulleys  106   b  are disposed on one end side of the ink receiving unit  14 . The turn-around pulley  106   a  and the turn-around pulleys  106   b  are disposed on the other end side of the ink receiving unit  14 , i.e. the opposite side of the ink receiver  102 . 
     The driving motor  206  is a motor which rotates in response to command of the controller  18 . The motor pinion gear  305  is attached to the rotary shaft of the driving motor  206  so that the motor pinion gear  305  rotates according to the rotation of the driving motor  206 . The drive gear  311  meshes with the motor pinion gear  305  so that the drive gear  311  rotates according to the rotation of the motor pinion gear  305 . The power transmitting shaft  308  is a shaft for holding the drive gear  311 . The power transmitting shaft  308  also holds the drive gear  312 , the torque limiter  309 , and the motor timing control fin  315  coaxially with the drive gear  311 . Accordingly, the drive gear  312  and the motor timing control fin  315  rotate according to the rotation of the drive gear  311 . The torque limiter  309  limits the rotary torque of the drive gear  311 . The motor control photosensor  314  is a sensor for detecting the rotation speed of the motor timing control fin  315  and feeding back the detection result to the controller  18 . Based on the rotation speed detected by the motor control photosensor  314 , the controller  18  controls the output to the driving motor  206 . 
     The two idler gears  313  are gears for alignment of the drum drive gear  307 . For mounting the ink receiving unit  14  to the main body  12 , the two idler gears  313  mesh with the drum drive gear  307  on the ink receiving unit  14  and the drive gear  312  on the main body  12 . Accordingly, the drum drive gear  307  rotates according to the rotation of the drive gear  312 . The drum shaft  306  is a shaft for holding the drum drive gear  307  and the wire drum  208  coaxially. The wire drum  208  is a drum on which the wire  108  is wound. As the wire drum  208  rotates according to the rotation of the drum drive gear  307 , the wire drum  208  moves the wire  108 , to which the wiper member  104  is attached, according to the output of the driving motor  206 . The pulleys  310  are disposed between the wire drum and the ink receiver  102  and cooperate together with the turn-around pulley  106   a  and the turn-around pulleys  106   b , arranged on the opposite side of the ink receiver  102 , to position the wire  108  such that the wire  108  extends along the ink receiver  102  with some tension. 
     In this example, the wiper member  104  can be suitably operated by the driving section  106  moving the wire  108 . Therefore, the ink in the ink receiver  102  can be suitably removed. Also in this example, the driving motor  206  and the wire drum  208  are positioned such that their rotary shafts extend parallel to each other. In addition, the rotary shafts of the respective gears between the driving motor  206  and the wire drum  208  also extend parallel to each other. According to this example, the power of the driving motor can be reliably transmitted to the wire drum with a simple structure. 
     Further in this example, the rotary shafts of the driving motor  206  and the wire drum  208 , and the rotary shafts of the drive gear  312 , the two idler gears  313 , and the drum drive gear  307  which are disposed between the driving motor  206  and the wire drum  208  extend parallel to the sub-scanning direction of the printing apparatus  10  (see  FIG. 1 ). The sub-scanning direction is parallel to the direction extending from the front surface to the back surface of the main body  12 . According to this example, for example, the ink receiving unit  14  can be suitably mounted to the main body  12  by pushing the ink receiving unit  14  into the main body  12  in a linear manner from the front side of the main body  12 . This also facilitates the mounting of the ink receiving unit  14 . 
     In the driving section  106  of this example, one way, to which the wiper member  104  is attached, of a round trip (loop) of the wire  108  tensioned in the ink receiver  102  is set to the center in the width direction of the ink receiver  102 . The pulleys  310  are arranged between the wire drum and the ink receiver  102 , and the turn-around pulley  106   a  and the turn-around pulleys  106   b  are disposed on the opposite side of the ink receiver  102  so that the other way to which the wiper member  104  is not attached (hereinafter, sometimes referred to as “returning way”) is set near the center in the width direction of the ink receiver  102  so that the returning way is located above the wire connecting portion  304  of the wiper member  104 . 
     The widespread portion  302  of the wiper member  104  expands in the width direction of the ink receiver  102 . Therefore, the wiper member  104  easily contacts with the returning way of the wire  108  at any portion. As the wiper member  104  and the returning way of the wire  108  contact with each other, the wiper member  104  is subjected to the force in the direction opposite to the advancing direction. If the returning way of the wire  108  is apart from the center in the width direction of the ink receiver  102 , large rotary torque is applied to the wiper  104  so that the wiper member  104  may easily rattle during the operation when the wiper member  104  and the returning way of the wire  108  contact with each other. 
     To solve this problem, in this example, the returning way of the wire  108  is set near the center in the width direction of the ink receiver  102  such that the returning way of the wire  108  is located above the wire connecting portion  304  of the wiper member  104 . In this case, even if the wiper member  104  is subjected to the force from the returning way of the wire  108 , large rotary torque is difficult to be produced. Therefore, according to this example, the rattling during the operation can be suitably prevented so that the wiper member  104  can suitably travel. This enables further suitable removal of the ink in the ink receiver  102 . 
       FIGS. 7(   a ) and  7 ( b ) show a second example of specific structure of the ink receiving unit  14 .  FIG. 7(   a ) shows the structure of one end side of the ink receiving unit  14  as well as the structure of some components of the main body  12  (see  FIG. 1) .  FIG. 7(   b ) shows the structure of the other end side of the ink receiving unit  14 . Besides points as will be described below, components with the same reference numerals as  FIGS. 4(   a ) and  4 ( b ) are the same components as those in the structure shown in  FIGS. 4(   a ) and  4 ( b ). 
     In this example, the rotary shaft of the driving motor  206  of the driving section  106  extends parallel to the main scanning direction of the printing apparatus  10  (see  FIG. 1 ). This arrangement can achieve reduction of size in the depth direction of the driving section  106  in the sub scanning direction of the printing apparatus  10 . Therefore, according to this example, the size in the depth direction required for installation of the ink receiving unit  14  can be reduced. Further, this arrangement can prevent the printing apparatus  10  from growing in size due to installation of the ink receiving unit  14 , for example. 
     Also in this example, no pulley is arranged between the wire drum  208  and the ink receiver  102 . In addition, only one turn-around pulley is arranged on the opposite side of the ink receiver  102 . Accordingly, this arrangement can reduce the number of components of the driving section  106 . Further, this arrangement can suitably reduce the cost of the ink receiving unit  14 , for example. 
       FIGS. 8(   a ) and  8 ( b ) schematically show a variation of the structure of the ink receiving unit  14 .  FIG. 8(   a ) is a top view of the ink receiving unit  14 .  FIG. 8(   b ) is a sectional side view of the ink receiving unit  14 . Besides points as will be described below, components with the same reference numerals as  FIGS. 4(   a ) and  4 ( b ) are the same components as those in the structure shown in  FIGS. 4(   a ) and  4 ( b ). 
     In this example, the ink receiving unit  14  has a belt member  110  as the ink removing means, instead of the wiper member  104  (see  FIGS. 4(   a ) and  4 ( b )). The belt member  110  is a band-like member having a movable ink receiving surface. In a state that the ink receiving unit  14  is attached to the main body  12 , the belt member  110  extends in the main scanning direction over the bottom surface of the gutter-like ink receiver  102 . The driving section  106  moves the belt member  110  by a mechanism similar to that for a belt of a moving walkway, a belt conveyor, or the like. Therefore, the belt member  110  moves along the bottom surface of the ink receiver  102  so as to remove the ink in the receiver  102 . Also according to this example, the ink in the ink receiver  102  can be suitably removed. 
     Though the present invention has been described with regard to the embodiments, the technical scope of the present invention is not limited to the scope described in the aforementioned embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be applied to the aforementioned embodiments. It is apparent from the claims of the present invention that embodiments with such modifications and improvements are within the technical scope of the present invention. 
     The embodiments of the present invention can be suitably applied to a printing apparatus, for example. 
     It should be noted that the exemplary embodiments depicted and described herein set forth the preferred embodiments of the present invention, and are not meant to limit the scope of the claims hereto in any way. Numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.