Patent Publication Number: US-11376853-B2

Title: Waste liquid recovery apparatus and inkjet recording apparatus

Description:
INCORPORATION BY REFERENCE 
     This application is based upon and claims the benefit of priority from the corresponding Japanese Patent Application No. 2019-186481 filed on Oct. 10, 2019, the entire contents of which are incorporated herein by reference. 
     BACKGROUND 
     The present disclosure relates to a waste liquid recovery apparatus that recovers waste liquid containing waste ink and issued during the cleaning of an ink head, and an inkjet recording apparatus including such a waste liquid recovery apparatus. 
     An inkjet recording apparatus for forming an image on a sheet by an inkjet system includes an ink head having an ink discharge portion in which a plurality of ink nozzles are formed. The inkjet recording apparatus may further include a cleaning device that cleans the ink head. 
     By the cleaning of the ink head, waste liquid containing waste ink and a liquid detergent having been used for the cleaning is issued. The waste liquid is recovered into a waste liquid container by a waste liquid recovery apparatus. 
     The waste liquid recovery apparatus includes a waste liquid tube having a terminal end disposed in the waste liquid container, and a pump that causes the waste liquid in the waste liquid tube to flow from a starting end of the waste liquid tube toward the terminal end. 
     SUMMARY 
     A waste liquid recovery apparatus according to an aspect of the present disclosure is a waste liquid recovery apparatus for recovering waste liquid containing waste ink and issued when an ink head that discharges ink onto a sheet is cleaned. The waste liquid recovery apparatus includes a waste liquid tube through which the waste liquid flows and a displacement mechanism. The displacement mechanism includes a driven portion that receives a driving force and operates owing to the driving force and a displacement portion that is displaced within a predetermined displacement range in conjunction with an operation of the driven portion. The waste liquid tube includes a flexible tube at least at a terminal end, from which the waste liquid is issued. When the displacement portion is displaced within the predetermined displacement range, a contact depth of the displacement portion with respect to a contacted portion of the flexible tube, near the terminal end, changes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a configuration diagram of an inkjet recording apparatus according to a first embodiment. 
         FIG. 2  is a configuration diagram of an inkjet unit in the inkjet recording apparatus according to the first embodiment. 
         FIG. 3  is a diagram illustrating a cleaning state of the inkjet recording apparatus according to the first embodiment. 
         FIG. 4  is a diagram illustrating an engaged state of the inkjet recording apparatus according to the first embodiment. 
         FIG. 5  is a diagram illustrating a cap state of the inkjet recording apparatus according to the first embodiment. 
         FIG. 6  is a perspective view of an ink head and a cleaning blade in the inkjet recording apparatus according to the first embodiment. 
         FIG. 7  is a configuration diagram of a waste liquid recovery apparatus in the inkjet recording apparatus according to the first embodiment. 
         FIG. 8  is a perspective view of a waste liquid tube and a displacement mechanism in the waste liquid recovery apparatus of the inkjet recording apparatus according to the first embodiment. 
         FIG. 9  is a configuration diagram of the displacement mechanism in a first state in the waste liquid recovery apparatus of the inkjet recording apparatus according to the first embodiment. 
         FIG. 10  is a configuration diagram of the displacement mechanism in a second state in the waste liquid recovery apparatus of the inkjet recording apparatus according to the first embodiment. 
         FIG. 11  is a configuration diagram of the displacement mechanism in a third state in the waste liquid recovery apparatus of the inkjet recording apparatus according to the first embodiment. 
         FIG. 12  is a configuration diagram of a displacement mechanism in a waste liquid recovery apparatus of an inkjet recording apparatus according to a second embodiment. 
         FIG. 13  is a configuration diagram of a displacement mechanism in a waste liquid recovery apparatus of an inkjet recording apparatus according to a third embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the following embodiments are each an example in which the present disclosure is embodied, and do not limit the technical scope of the present disclosure. 
     First Embodiment: Configuration of Inkjet Recording Apparatus  10   
     An inkjet recording apparatus  10  according to a first embodiment is a printer capable of performing a printing process by an inkjet method. The printing process is a process of forming an image on a sheet  9 . The sheet  9  is a sheet-like image forming medium such as paper or a resin film. 
     The inkjet recording apparatus  10  may be a facsimile apparatus, a copier, a multifunction peripheral, or the like capable of executing the printing process by an inkjet method. 
     As shown in  FIG. 1 , the inkjet recording apparatus  10  includes a sheet storage portion  12 , a sheet conveying device  2 , an inkjet unit  3 , an ink supply unit  4 , a cleaning unit  5 , a capping unit  6 , and a controller  8 . The inkjet unit  3  includes a plurality of ink heads  31 . 
     The sheet conveying device  2 , the inkjet unit  3 , the ink supply unit  4 , the cleaning unit  5 , the capping unit  6 , and the controller  8  are housed in a housing  11  that forms a main body. 
     The sheet storage portion  12  can store a plurality of sheets  9 . The sheet conveying device  2  conveys the sheets  9  accommodated in the sheet storage portion  12  one by one along a sheet conveying path  20 , and further discharges the sheets from the sheet conveying path  20  to the discharge tray  13 . 
     The sheet conveying device  2  includes a sheet feeding portion  21 , a plurality of conveying roller pairs  22 , a main conveying unit  23 , a downstream conveying unit  24 , and a discharge roller pair  25 . The sheet feeding portion  21  feeds the sheets  9  one by one from the sheet storage portion  12  to the sheet conveying path  20 . 
     The plurality of conveying roller pairs  22  take over the conveyance of the sheet  9  from the sheet feeding portion  21  and convey the sheet  9  toward the main conveying unit  23 . 
     The main conveying unit  23  is disposed below the inkjet unit  3 . The main conveying unit  23  conveys the sheet  9  in a predetermined conveying direction D 0  while causing the front side of the sheet  9  to face the inkjet unit  3 . 
     A direction orthogonal to the conveying direction D 0  is a main-scanning direction D 1 , and a direction opposite to the conveying direction D 0  is a sub-scanning direction D 2  (see  FIGS. 1 and 2 ). 
     In the main conveying unit  23 , a plurality of stretching rollers  231  rotate an endless main conveying belt  230  while supporting the endless main conveying belt  230 . Thus, the main conveying unit  23  conveys the sheet  9  in the conveying direction D 0  on the main conveying belt  230 , and further feeds the sheet  9  to the downstream conveying unit  24 . A gap between the upper surface of the main conveying belt  230  and the plurality of ink heads  31  forms a part of the sheet conveying path  20 . 
     That is, the main conveying unit  23  is supported at a reference position where the sheet conveying path  20  is formed between the main conveying unit  23  and the plurality of ink heads  31  when the printing process is performed.  FIG. 1  shows a state in which the main conveying unit  23  is located at the reference position. 
     The main conveying unit  23  is so supported as to be movable to a conveyance waiting position that is farther from the plurality of ink heads  31  than the reference position.  FIGS. 3 to 5  show a state in which the main conveying unit  23  is at the conveyance waiting position. In the present embodiment, the conveyance waiting position is a position vertically below the reference position. 
     The downstream conveying unit  24  is disposed downstream of the main conveying unit  23  located at the reference position in the conveying direction D 0 . In the downstream conveying unit  24 , stretching rollers  241  support and rotate a downstream conveying belt  240 . Thus, the downstream conveying unit  24  conveys the sheet  9 , on which the image is formed, on the downstream conveying belt  240 , and further feeds the sheet  9  to the discharge roller pair  25 . 
     The discharge roller pair  25  is disposed on the downstream side in the conveying direction D 0  with respect to the downstream conveying unit  24 . The discharge roller pair  25  discharges the sheet  9 , on which the image is formed, to the discharge tray  13 . 
     The inkjet unit  3  includes the plurality of ink heads  31  and an ink head support  30  that supports the plurality of ink heads  31 . The plurality of ink heads  31  form an image on the sheet  9  by jetting inks of a plurality of colors toward the sheet  9  being conveyed by the main conveying unit  23 . 
     In the example shown in  FIG. 1 , the plurality of ink heads  31  are divided into four line heads  300  corresponding to black, cyan, magenta, and yellow inks. The ink supply unit  4  supplies ink of each color to the plurality of ink heads  31 . 
     The four line heads  300  are arranged side by side in the sub-scanning direction D 2  and are fixed in a predetermined positional relationship (see  FIGS. 1 and 2 ). The number of the line heads  300  included in the inkjet unit  3  may be three or five or more. 
     The plurality of ink heads  31  are arranged such that gaps of about 1 mm are formed between ink discharge portions  31 A of the plurality of ink heads  31  and the upper surface of the sheet  9  on the main conveying belt  230 . The ink discharge portions  31 A are in lower surfaces of the ink heads  31 , respectively. 
     As shown in  FIG. 2 , the plurality of ink heads  31  are arranged in a state in which the longitudinal direction of each ink head coincides with the main-scanning direction D 1 . A plurality of ink nozzles  31 B for discharging ink to the sheet  9  conveyed along the sheet conveying path  20  are formed in the ink discharge portion  31 A of each of the ink heads  31 . 
     Each of the ink heads  31  includes a plurality of piezoelectric elements (not shown) corresponding to the plurality of ink nozzles  31 B. Each of the piezoelectric elements vibrates when a drive signal is supplied from the controller  8 , thereby pressurizing the ink and jetting the ink from each of the ink nozzles  31 B. 
     The controller  8  includes a micro processing unit (MPU)  81 , a random access memory (RAM)  82 , and a secondary storage device  83 . 
     The MPU  81  is a processor that executes various types of data processing and control by executing a computer program. The RAM  82  is a computer-readable volatile storage device. The RAM  82  as a primary storage device stores the computer program executed by the MPU  81  and the data output and referenced by the MPU  81  in the course of execution of various processes. 
     The secondary storage device  83  is a computer-readable non-volatile storage device. The secondary storage device  83  can store and update the computer program and various data. For example, one or both of a flash memory and a hard disk drive are employed as the secondary storage device  83 . 
     In the inkjet recording apparatus  10 , a blade-type cleaning device is employed as a device for cleaning the ink discharge portion  31 A. The blade-type cleaning device includes a detergent supply portion  32  provided in each of the ink heads  31  and a cleaning blade  51  that slides with respect to the ink discharge portion  31 A of each of the ink heads  31  (see  FIG. 5 ). 
     The detergent supply portion  32  is a portion in which a supply port  32 B for a liquid detergent is formed (see  FIGS. 2 and 6 ). A foamy liquid detergent is supplied through the supply port  32 B and used for cleaning the ink discharge portion  31 A. 
     As shown in  FIG. 1 , the cleaning unit  5  is supported at a cleaning waiting position where the cleaning unit  5  does not interfere with the main conveying unit  23  at the reference position. The cleaning unit  5  includes a plurality of cleaning blades  51  corresponding to the plurality of ink heads  31 . 
     In the example shown in  FIG. 1 , the cleaning waiting position is a position obliquely below the main conveying unit  23  at the reference position. The cleaning waiting position is a position between the reference position and the conveyance waiting position of the main conveying unit  23  in the height direction. 
     Each of the cleaning blades  51  is an elastic member. For example, the cleaning blade  51  is a plate-shaped rubber member. Further, the cleaning unit  5  includes a blade support  50  that supports the plurality of cleaning blades  51 . 
     The cleaning unit  5  is movably supported between the cleaning waiting position and a cleaning position where the cleaning blade  51  is in contact with the lower surface of the ink head  31 .  FIG. 3  shows a state in which the cleaning unit  5  is located at the cleaning position. 
     The inkjet recording apparatus  10  further includes a unit moving device  7  that moves the main conveying unit  23  and the cleaning unit  5 . The unit moving device  7  moves the main conveying unit  23  from the reference position to the conveyance waiting position when a predetermined cleaning start condition is satisfied. The cleaning start condition is, for example, a condition that the printing process has been executed on a predetermined number of sheets  9 . 
     Further, the unit moving device  7  moves the cleaning unit  5  from the cleaning waiting position to the cleaning position in a state where the main conveying unit  23  has moved to the conveyance waiting position. 
     The cleaning unit  5  further includes a blade moving device  52  that moves the plurality of cleaning blades  51  along the main-scanning direction D 1 . The blade moving device  52  moves the plurality of cleaning blades  51  when the cleaning unit  5  is located at the cleaning position. 
     The blade moving device  52  of the cleaning unit  5  slides each of the cleaning blades  51  with respect to the detergent supply portion  32  and the ink discharge portion  31 A in each of the ink heads  31  in a state where the cleaning unit  5  is held at the cleaning position (see  FIG. 6 ). 
     That is, the cleaning blade  51  slides on the detergent supply portion  32  and the ink discharge portion  31 A in each of the ink heads  31 . The cleaning blade  51  scrapes off ink stains while applying the liquid detergent to the ink discharge portion  31 A. 
     A state in which the cleaning unit  5  is held at the cleaning position and the plurality of cleaning blades  51  slide with respect to the plurality of ink heads  31  is a cleaning state (see  FIG. 3 ). 
     By the cleaning of the ink head  31  by the cleaning blade  51 , waste liquid containing waste ink, which is the ink removed from the ink head  31 , and the used liquid detergent is issued. The waste liquid falls downward from the ink head  31 . 
     The cleaning unit  5  further includes a waste liquid recovery apparatus  500  that recovers the waste liquid falling from the ink head  31  (see  FIG. 1 ). The waste liquid recovery apparatus  500  includes a waste liquid tray  54 , a waste liquid tube  55 , a pump  56 , and a waste liquid container  57  (see  FIGS. 1 and 7 ). 
     The waste liquid tray  54  receives the waste liquid falling from the cleaning unit  5  and collects the waste liquid in one place. The waste liquid tray  54  includes an inclined plate  541  and a waste liquid reservoir  542 . The inclined plate  541  receives the falling waste liquid and guides the waste liquid to the waste liquid reservoir  542 . The waste liquid is temporarily stored in the waste liquid reservoir  542 . 
     The waste liquid tube  55  is a tube that forms a flow path of the waste liquid. A starting end  55   a  of the waste liquid tube  55  is connected to an outlet  542   a  of the waste liquid reservoir  542 , and a terminal end  55   b  of the waste liquid tube  55  is disposed in the waste liquid container  57 . 
     The pump  56  causes the waste liquid in the waste liquid tube  55  to flow from the starting end  55   a  to the terminal end  55   b  of the waste liquid tube  55 . By operating the pump  56 , the waste liquid is conveyed from the waste liquid reservoir  542  to the waste liquid container  57 . As a result, the waste liquid is collected in the waste liquid container  57 . 
     The MPU  81  includes a plurality of processing modules realized by executing the computer program. The processing modules include a printing controller  81   a , a cleaning controller  81   b , and a recovery controller  81   c.    
     The printing controller  81   a  controls the sheet conveying device  2 , the inkjet unit  3 , and the like to cause the inkjet unit  3  to execute the printing process. 
     The cleaning controller  81   b  controls the movement of the main conveying unit  23  and the movement of the cleaning unit  5  by controlling the unit moving device  7 . Further, the cleaning controller  81   b  controls the movement of the cleaning blades  51  by controlling the blade moving device  52 . 
     The recovery controller  81   c  controls the waste liquid recovery apparatus  500 . To be specific, the recovery controller  81   c  operates the pump  56  when the ink head  31  is cleaned, and stops the pump  56  after the cleaning of the ink head  31  is finished. The recovery controller  81   c  is an example of a controller constituting a part of the waste liquid recovery apparatus  500 . 
     The inkjet recording apparatus  10  further includes a capping unit  6  (see  FIGS. 1 and 5 ). The capping unit  6  includes a plurality of caps  61  covering the plurality of ink nozzles  31 B. 
     The capping unit  6  is supported at a capping waiting position where the capping unit  6  is aligned with the cleaning unit  5  at the cleaning waiting position.  FIGS. 1 and 2  show a state in which the capping unit  6  is located at the capping waiting position. In the example shown in  FIGS. 1 and 2 , the capping waiting position is a position above the cleaning unit  5  in the cleaning waiting position. 
     The capping unit  6  includes a cap support  60  that supports the plurality of caps  61  (see  FIG. 1 ). The capping unit  6  is so supported as to be movable from the capping waiting position to a capping position where the capping unit  6  faces the ink heads  31 .  FIG. 5  shows the capping unit  6  in the capping position. 
     When the capping unit  6  is at the capping position, each of the caps  61  covers the plurality of ink nozzles  31 B in each of the ink heads  31 . Thus, clogging of the ink nozzles  31 B due to solidification of the ink in the ink nozzles  31 B is prevented. 
     The cleaning unit  5  is so constructed as to be engageable with the capping unit  6 . Specifically, the cap support  60  of the capping unit  6  includes an engaged portion  62 , and the blade support  50  of the cleaning unit  5  includes an engaging portion  53  that engages with the engaged portion  62  (see  FIG. 1 ). 
     When the cleaning unit  5  moves from the cleaning waiting position to an engagement position, the engaging portion  53  engages with the engaged portion  62 . When the engaging portion  53  engages with the engaged portion  62 , the capping unit  6  moves together with the cleaning unit  5  when the cleaning unit  5  moves. 
     A state in which the cleaning unit  5  engages with the capping unit  6  as a result of the movement of the cleaning unit  5  to the engagement position is an engagement state (see  FIG. 4 ). 
     As described above, the unit moving device  7  first moves the cleaning unit  5  from the cleaning waiting position to the cleaning position in a state where the main conveying unit  23  has moved to the conveyance waiting position. 
     While the cleaning unit  5  is held at the cleaning position, the blade moving device  52  slides the plurality of cleaning blades  51  with respect to the plurality of ink heads  31 . 
     Next, the unit moving device  7  returns the cleaning unit  5  from the cleaning position to the cleaning waiting position, and then moves the cleaning unit  5  from the cleaning waiting position to a cap supporting position via the engagement position. 
     When the cleaning unit  5  moves from the engagement position to the cap supporting position, the capping unit  6  moves from the capping waiting position to the capping position (see  FIG. 5 ). That is, the unit moving device  7  is also a device that moves the capping unit  6  from the capping waiting position to the capping position. 
     The output of the pump  56  may be changed in accordance with the state of the inkjet recording apparatus  10  when the ink head  31  is cleaned. For example, when the cleaning of the ink head  31  is performed at relatively short intervals, the recovery controller  81   c  operates the pump  56  at a lower output than usual. 
     When the pump  56  is operated at a low output, the force of ejecting the waste liquid from the terminal end  55   b  of the waste liquid tube  55  is weak. In this case, the waste liquid may flow backward along the outer surface of a portion of the waste liquid tube  55  near the terminal end  55   b  and contaminate the periphery of the waste liquid tube  55 . 
     On the other hand, when a thin waste liquid tube  55  corresponding to the case where the pump  56  operates at a low output is adopted, if the pump  56  operates at a normal output, a large pressure loss of the waste liquid tube  55  may hinder a smooth flow of the waste liquid. 
     The waste liquid recovery apparatus  500  has a configuration that prevents the waste liquid from flowing backward along the outer surface of a portion of the waste liquid tube  55  near the terminal end  55   b  when the output of the pump  56  is changed. Hereinafter, the configuration will be described. 
     As shown in  FIG. 8 , the waste liquid tube  55  of the waste liquid recovery apparatus  500  includes one or more joint tubes  551  and a plurality of flexible tubes  550  connected by the joint tubes  551 . The joint tubes  551  and the flexible tubes  550  are each a part of the waste liquid tube  55 . 
     The flexible tube  550  is excellent in that the flexible tube  550  can be arranged correspondingly to various paths. The entire waste liquid tube  55  may be formed of the flexible tube  550 . 
     The joint tube  551  is a hard member made of a synthetic resin. Each of the flexible tubes  550  is a flexible member mainly composed of, for example, soft vinyl chloride or soft polyvinyl chloride. 
     One end of the flexible tube  550  includes a terminal flexible tube  550   x , which constitutes the terminal end  55   b  of the waste liquid tube  55 . That is, the terminal end of the terminal flexible tube  550   x  is the terminal end  55   b  of the waste liquid tube  55 . 
     The waste liquid recovery apparatus  500  further includes a tube holding member  552 . The tube holding member  552  is a hard member made of a synthetic resin. The tube holding member  552  holds the terminal flexible tube  550   x  along a curved path. 
     In the example shown in  FIG. 8 , the tube holding member  552  turns the terminal flexible tube  550   x  by 90° along the curved path. 
     While the terminal flexible tube  550   x  is of a soft nature, the tube holding member  552  allows the terminal flexible tube  550   x  to follow a certain path. Further, the tube holding member  552  suppresses vibration of the terminal flexible tube  550   x.    
     An opening  552   a  is formed in a portion of the tube holding member  552  near the terminal end  55   b  of the terminal flexible tube  550   x . The opening  552   a  is formed in a partial range of the tube holding member  552  in the circumferential direction. 
     Therefore, a part in the circumferential direction of the portion of the terminal flexible tube  550   x  near the terminal end  55   b  is exposed from the opening  552   a  of the tube holding member  552 . 
     As shown in  FIG. 8 , the waste liquid recovery apparatus  500  further includes a displacement mechanism  58 . The displacement mechanism  58  includes a movable member  581  and a support frame  580  that rotatably supports the movable member  581 . 
     The movable member  581  includes a driven portion  5811 , a coupling portion  5812 , and a displacement portion  5813 . The driven portion  5811  is a portion that operates by receiving a driving force. In the present embodiment, the driven portion  5811  is an operated portion that mechanically receives the driving force by a human operation. 
     To be specific, the driven portion  5811  is formed with a knob portion  5811   a  to be held by a human hand. The knob portion  5811   a  is a portion that receives a rotation operation. That is, the driving force in the present embodiment is a rotational driving force by a human operation. 
     The coupling portion  5812  couples the driven portion  5811  and the displacement portion  5813  together. The displacement portion  5813  is displaced within a predetermined displacement range in conjunction with the rotational operation of the driven portion  5811 . 
     In the present embodiment, the displacement portion  5813  turns around the rotation center line of the driven portion  5811  when the driven portion  5811  rotates. That is, the displacement portion  5813  turns within a predetermined turning range in conjunction with the rotational operation of the driven portion  5811  (see  FIGS. 8 to 11 ). 
       FIG. 9  shows the displacement mechanism  58  when the displacement portion  5813  exists at the start point of the predetermined displacement range.  FIG. 11  shows the displacement mechanism  58  when the displacement portion  5813  is present at the end point of the predetermined displacement range.  FIG. 10  shows the displacement mechanism  58  when the displacement portion  5813  is located at an intermediate position between the start point and the end point within the predetermined displacement range. 
     When the displacement portion  5813  is displaced within the predetermined displacement range, the displacement portion  5813  comes into contact with a contacted portion  55   c  which is a portion of the terminal flexible tube  550   x  near the terminal end  55   b . In the present embodiment, the contacted portion  55   c  is a portion exposed from the opening  552   a  of the tube holding member  552 . 
     As shown in  FIGS. 8 to 11 , a portion of the tube holding member  552  opposite to the opening  552   a  is a back surface supporting portion  552   b . The back surface supporting portion  552   b  supports the back surface of the contacted portion  55   c  of the terminal flexible tube  550   x.    
     As shown in  FIGS. 9 to 11 , when the displacement portion  5813  is displaced within the predetermined displacement range, the contact depth of the terminal flexible tube  550   x  with respect to the contacted portion  55   c  changes. That is, the contacted portion  55   c  of the terminal flexible tube  550   x  deforms to a flat shape by the pressing by the displacement portion  5813 , and the degree of flatness of the contacted portion  55   c  changes according to the displacement of the displacement portion  5813  (see  FIGS. 9 to 11 ). 
     When the degree of flatness of the contacted portion  55   c  changes, the cross-sectional area of the hollow portion of the contacted portion  55   c  changes. As shown in  FIGS. 9 to 11 , as the displacement portion  5813  is displaced from the start point to the end point of the predetermined displacement range, the cross-sectional area of the passage of the waste liquid in the contacted portion  55   c  is narrowed. 
     In the case where the waste liquid recovery apparatus  500  is employed, when the recovery controller  81   c  changes the output of the pump  56 , the cross-sectional area of the passage of the waste liquid in the contacted portion  55   c  can be changed by the operation of the knob portion  5811   a.    
     For example, it is conceivable that the output of the pump  56  can be changed in three stages of a rated output, an intermediate output, and a low output. In this case, it is conceivable that the recovery controller  81   c  controls the output of the pump  56  in accordance with an action entry operation on an operation device (not shown) such as a touch panel. The recovery controller  81   c  controls the output of the pump  56  by controlling the amount of power supplied to the pump  56 . 
     In the above case, when the output of the pump  56  is set to the rated output, the knob portion  5811   a  is operated so that the displacement portion  5813  is located at the start point of the predetermined displacement range. When the output of the pump  56  is set to the intermediate output, the knob portion  5811   a  is operated so that the displacement portion  5813  is located at the intermediate position of the predetermined displacement range. When the output of the pump  56  is set to the low output, the knob portion  5811   a  is operated so that the displacement portion  5813  is located at the end point of the predetermined displacement range. 
     By changing the state of the displacement mechanism  58  as described above in accordance with the output of the pump  56 , a considerable decrease in the ejection speed of the waste liquid from the terminal end  55   b  of the terminal flexible tube  550   x  is avoided. As a result, it is possible to prevent the waste liquid from flowing backward along the outer surface of a portion of the terminal flexible tube  550   x  near the terminal end  55   b.    
     Second Embodiment 
     Next, an inkjet recording apparatus  10 X according to a second embodiment will be described with reference to  FIG. 12 . 
     The inkjet recording apparatus  10 X has a configuration in which the waste liquid recovery apparatus  500  in the inkjet recording apparatus  10  is replaced with a waste liquid recovery apparatus  500 X. Hereinafter, differences between the waste liquid recovery apparatus  500 X and the waste liquid recovery apparatus  500  will be described. 
     The waste liquid recovery apparatus  500 X has a configuration in which a detection target  5814  and a plurality of object detection sensors  800  are added to the waste liquid recovery apparatus  500 . 
     The detection target  5814  is displaced in conjunction with the operation of the driven portion  5811 . In the example shown in  FIG. 12 , the detection target  5814  is formed integrally with the driven portion  5811  and protrudes from the driven portion  5811 . 
     For example, the object detection sensor  800  may be a transmissive photosensor or a reflective photosensor. The object detection sensor  800  may also be a contact sensor such as a microswitch. 
     The object detection sensor  800  detects the detection target  5814  so as to detect at which of the start point, the intermediate position, and the end point of the predetermined displacement range the displacement portion  5813  is present. 
     The plurality of object detection sensors  800  detect that the detection target  5814  is present at any of a plurality of predetermined positions. The object detection sensors  800  exemplify a state detection sensor that detects the state of the driven portion  5811  or the displacement portion  5813  in the displacement mechanism  58 . 
     Also in the present embodiment, the driven portion  5811  is an operated portion that mechanically receives the driving force by a human operation. In the present embodiment, the recovery controller  81   c  controls the output of the pump  56  in accordance with the detection result of the object detection sensors  800 . 
     To be specific, when the detection result of the object detection sensors  800  indicates that the displacement portion  5813  is positioned at the start point of the predetermined displacement range, the recovery controller  81   c  sets the output of the pump  56  to the rated output. 
     When the detection result of the object detection sensors  800  indicates that the displacement portion  5813  is located at the intermediate position of the predetermined displacement range, the recovery controller  81   c  sets the output of the pump  56  to the intermediate output. 
     When the detection result of the object detection sensors  800  indicates that the displacement portion  5813  is positioned at the end point of the predetermined displacement range, the recovery controller  81   c  sets the output of the pump  56  to the low output. 
     Also in the case where the waste liquid recovery apparatus  500 X is employed, the same effects are obtained as in the case where the waste liquid recovery apparatus  500  is employed. 
     Third Embodiment 
     Next, an inkjet recording apparatus  10 Y according to a third embodiment will be described with reference to  FIG. 13 . 
     The inkjet recording apparatus  10 Y has a configuration in which the waste liquid recovery apparatus  500  in the inkjet recording apparatus  10  is replaced with a waste liquid recovery apparatus  500 Y. Hereinafter, differences between the waste liquid recovery apparatus  500 Y and the waste liquid recovery apparatus  500  will be described. 
     The waste liquid recovery apparatus  500 Y has a configuration in which the displacement mechanism  58  in the waste liquid recovery apparatus  500  is replaced with a displacement mechanism  58 Y and a driving device  59  is added. 
     The displacement mechanism  58 Y includes a support frame  580  and a movable member  581 X. The movable member  581 X includes a shaft portion  5815  rotatably supported by the support frame  580 , as well as a cam portion  5816  and a link portion  5817  both formed integrally with the shaft portion  5815 . 
     The link portion  5817  is a portion that is coupled to the driving device  59  and receives a driving force from the driving device  59 . In the present embodiment, the link portion  5817  is an example of a driven portion that operates by receiving a driving force. The driving device  59  applies the driving force to the link portion  5817 . 
     The driving device  59  is, for example, an actuator such as a solenoid. The link portion  5817  is displaced by the operation of the driving device  59 , and the cam portion  5816  is displaced in conjunction with the link portion  5817 . In the present embodiment, the cam portion  5816  is an example of a displacement portion that is displaced within a predetermined displacement range in conjunction with the operation of the link portion  5817 . 
     When the cam portion  5816  is displaced within the predetermined displacement range, the cam portion  5816  comes into contact with the contacted portion  55   c  which is a portion of the terminal flexible tube  550   x  near the terminal end  55   b.    
     When the cam portion  5816  is displaced within the predetermined displacement range, the contact depth of the terminal flexible tube  550   x  with respect to the contacted portion  55   c  changes. The contacted portion  55   c  of the terminal flexible tube  550   x  deforms to a flat shape by the pressing by the cam portion  5816 , and the degree of flatness of the contacted portion  55   c  changes according to the displacement of the cam portion  5816 . 
     As described above, it is conceivable that the recovery controller  81   c  controls the output of the pump  56  in accordance with an action entry operation on an operation device (not shown) such as a touch panel. 
     In the present embodiment, when changing the output of the pump  56 , the recovery controller  81   c  changes the contact depth of the cam portion  5816  with respect to the contacted portion  55   c  by controlling the driving device  59 . 
     Also in the case where the waste liquid recovery apparatus  500 Y is employed, the same effects are obtained as in the case where either of the waste liquid recovery apparatuses  500  and  500 X is employed.