Patent Publication Number: US-10766261-B2

Title: Head cleaning device and liquid discharge apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application is based on and claims priority pursuant to 35 U.S.C. § 119(a) to Japanese Patent Application Nos. 2018-051558, filed on Mar. 19, 2018, and 2019-018202, filed on Feb. 4, 2019, in the Japan Patent Office, the entire disclosure of each of which is hereby incorporated by reference herein. 
     BACKGROUND 
     Technical Field 
     Aspects of the present disclosure relate to a head cleaning device and a liquid discharge apparatus. 
     Related Art 
     Conventionally, there has been known an image forming apparatus including liquid-droplet discharge nozzles of a plurality of liquid-droplet discharge heads that are arranged, the image forming apparatus being to discharge liquid droplets from the arranged liquid-droplet discharge nozzles to form an image on a printing medium. For example, for an image forming apparatus termed an inkjet printer including this type of liquid-droplet discharge head, adhesion of ink to the nozzle face of an inkjet head stains the nozzle face for discharge of ink. Thus, this type of image forming apparatus is equipped with a cleaning unit that cleans ink. For example, a type of cleaning unit wipes the ink stain adhering to the nozzle face of the inkjet head, with a web and a wiper blade. 
     Such a cleaning unit that performs wiping with the web and the wiper blade, is provided with a drive source and a drive assembly for each of the web and the wiper blade, to move the web and the wiper blade each to a wiping position or a retraction position. However, provision of individual drive sources and drive assemblies increases an apparatus in size, resulting in increase in costs, rightfully. 
     SUMMARY 
     In an aspect of the present disclosure, there is provided a head cleaning device that includes a first wiping member, a first drive mechanism, a second wiping member, a second drive mechanism, a common drive source, and control circuitry. The first wiping member wipes a nozzle face of each of a plurality of liquid discharge heads. The first drive mechanism moves the first wiping member to a first wiping position at which the first wiping member wipes the nozzle face and a first retraction position spaced apart from the nozzle face. The second wiping member wipes the nozzle face. The second drive mechanism moves the second wiping member to a second wiping position at which the second wiping member wipes the nozzle face and a second retraction position spaced apart from the nozzle face. The common drive source drives the first drive mechanism and the second drive mechanism. The control circuitry controls the common drive source. 
     In another aspect of the present disclosure, there is provided a liquid discharge apparatus that includes the head cleaning device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete appreciation of the disclosure and many of the attendant advantages and features thereof can be readily obtained and understood from the following detailed description with reference to the accompanying drawings, wherein: 
         FIG. 1  is a schematic view of the configuration of an inkjet recording apparatus according to a first embodiment of the present disclosure; 
         FIG. 2  is a main plan view of an image forming device before each rail member moves in a sheet-width direction in the first embodiment; 
         FIG. 3  is a main plan view of the image forming device after each rail member moves in the sheet-width direction in the first embodiment; 
         FIG. 4  is an explanatory view of the wiping operation of a wiping unit according to the first embodiment (before a wiping start); 
         FIG. 5  is an explanatory view of the wiping operation of the wiping unit according to the first embodiment (during web wiping); 
         FIG. 6  is an explanatory view of the wiping operation of the wiping unit according to the first embodiment (during wiper wiping); 
         FIG. 7  is an explanatory schematic view of the configuration of a wiping unit that drives a web and a wiper separately, with a first wiping member at a wiping position; 
         FIG. 8  is an explanatory schematic view of the configuration of the wiping unit that drives the web and the wiper separately, with a second wiping member at a wiping position; 
         FIG. 9  is an explanatory schematic view of the configuration of a wiping unit according to the first embodiment that drives a web and a wiper with a common drive source, with the web at a wiping position; 
         FIG. 10  is an explanatory schematic view of the configuration of the wiping unit according to the first embodiment that drives the web and the wiper with the common drive source, with the wiper at a wiping position; 
         FIG. 11  is an explanatory schematic view of the configuration of a wiping unit according to a second embodiment that drives a web and a wiper with common drive source; 
         FIG. 12  is an explanatory schematic view of the configuration of the wiping unit according to the second embodiment that drives the web and the wiper with the common drive source, with the web at a wiping position; 
         FIG. 13  is an explanatory schematic view of the configuration of the wiping unit according to the second embodiment that drives the web and the wiper with the common drive source, with the wiper at a wiping position; 
         FIG. 14  is an explanatory operation view of the wiping operation of the web on the nozzle face of a liquid discharge head in the second embodiment; 
         FIG. 15  is an explanatory operation view of the web and the wiper retracted from the nozzle face of the liquid discharge head in the second embodiment; 
         FIG. 16  is an explanatory operation view just before the wiper starts wiping operation after an advance of the wiper between adjacent liquid discharge nozzles of the liquid discharge head, in the second embodiment; 
         FIG. 17  is an explanatory operation view of the wiper wiping the nozzle face of the liquid discharge head in the second embodiment; 
         FIG. 18  is an explanatory operation view immediately after the wiper wipes the nozzle face of the liquid discharge head in the second embodiment; 
         FIG. 19  is an explanatory operation view of the web wiping the nozzle face of the liquid discharge head while the web is moving in one direction, in the second embodiment; 
         FIG. 20  is an explanatory operation view of the wiper wiping the nozzle face of the liquid discharge head while the wiper is moving in the other direction, in the second embodiment; 
         FIG. 21  is an explanatory view of the movement operation of a web when a pressing member moves from a wiping position to a retraction position in a third embodiment; 
         FIG. 22  is an explanatory view of the web staying at the wiping position from the state of  FIG. 21 ; 
         FIG. 23  is an explanatory view of an operation of reeling in the web from the state of  FIG. 21  to move the web to the retraction position, reliably; 
         FIG. 24  is a block diagram of a control configuration according to the second embodiment; and 
         FIG. 25  is a flowchart of an operation procedure of wiping operation according to the second embodiment. 
     
    
    
     The accompanying drawings are intended to depict embodiments of the present disclosure and should not be interpreted to limit the scope thereof. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. 
     DETAILED DESCRIPTION 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. 
     In describing embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this specification is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes all technical equivalents that have a similar function, operate in a similar manner, and achieve a similar result. 
     According to a gist of the present disclosure, there is provided a head cleaning device that performs, for example, wiping with a web and a wiper blade to clean a stain adhering to the nozzle face of an inkjet head that discharges liquid, in which the movement operation of a web presser between a wiping position and a retraction position that are invariant regardless of the amount of reeling of the web, and the movement operation of the wiper blade between a wiping position and a retraction position, are performed with a common (shared) drive source. Embodiments of the present disclosure will be described below with reference to the drawings. 
     A “liquid discharge apparatus” according to the present embodiment includes a head that discharges liquid, and drives the head to discharge the liquid. Examples of the “liquid discharge apparatus” include an apparatus that discharges liquid in the air or in liquid as well as an apparatus capable of discharging liquid to an object to which discharging is to be performed. For example, an image forming apparatus, a three-dimensionally shaping apparatus, a treatment-liquid coating apparatus, and a jet granulation apparatus are applicable. According to the present embodiment, as one example of the “liquid discharge apparatus”, an inkjet recording apparatus that is an image forming apparatus, is exemplified. 
     In the following descriptions, the same constituent elements or similar constituent elements are denoted with the same reference signs, and thus the descriptions of the constituent elements will be omitted appropriately. 
     First Embodiment 
     General Description 
       FIG. 1  is a schematic view of the configuration of an inkjet recording apparatus  1  according to a first embodiment of the present disclosure. As illustrated in  FIG. 1 , the inkjet recording apparatus  1  as an image forming system basically includes a sheet feeder  100 , an image forming device  200 , a dryer  300 , and a sheet ejector  400 . In the inkjet recording apparatus  1 , the image forming device  200  discharges ink that is liquid for image forming, to a sheet P that is a recording material including a sheet material as a medium fed from the sheet feeder  100 , to form an image. The dryer  300  dries the ink adhering onto the sheet P, and then the sheet ejector  400  ejects the sheet P. 
     Sheet Feeder 
     The sheet feeder  100  includes a sheet feeding tray  110  in which a plurality of sheets P is loaded, a feeding device  120  that separates the sheets one by one from the sheet feeding tray  110  to feed a sheet out, and a pair of registration rollers  130  that feeds the sheet into the image forming device  200 . For the feeding device  120 , any publicly known feeding device having a feeding function, can be used, such as a device employing rollers and rolling elements or a device utilizing air suction. A sheet P fed out from the sheet feeding tray  110  by the feeding device  120 , is fed to the image forming device  200  by driving of the pair of registration rollers  130  at a predetermined timing after arrival of the front end of the sheet P at the pair of registration rollers  130 . Note that, in the present embodiment, the configuration of the sheet feeder  100  is not particularly limited as long as the sheet feeder  100  has a function of feeding a sheet P out to the image forming device  200 . 
     Image Forming Device 
     The image forming device  200  includes a receiving cylinder  201 , a sheet conveying drum  210  (conveying member), an ink discharger  220 , and a delivering cylinder  202 . The receiving cylinder  201  receives the fed sheet P (recording medium). The sheet conveying drum  210  that is a cylindrical conveying member, conveys the sheet P conveyed by the receiving cylinder  201  while bearing the sheet P on the outer circumferential face of the sheet conveying drum  210 . The ink discharger  220  discharges ink to the sheet P conveyed by the sheet conveying drum  210 . The delivering cylinder  202  delivers the sheet P conveyed by the sheet conveying drum  210 , to the dryer  300 . 
     The sheet P conveyed from the sheet feeder  100  to the image forming device  200 , is conveyed along with movement of the surface of the receiving cylinder  201 , with the front end of the sheet P gripped by a sheet gripper  210   a  provided on the surface of the receiving cylinder  201 . The sheet P conveyed by the receiving cylinder  201  is delivered to the sheet conveying drum  210  at a position opposed to the sheet conveying drum  210 . Note that the sheet gripper  210   a  has a publicly known structure. 
     A sheet gripper  210   a  is provided on the surface of the sheet conveying drum  210 , and the front end of the sheet P is gripped by the sheet gripper  210   a . The surface of the sheet conveying drum  210  has a plurality of distributed suction holes. A suction device  211  generates a suction flow to the inside of the sheet conveying drum  210 , in each suction hole. Due to the suction flows, the sheet P is attracted to the surface of the sheet conveying drum  210 . The sheet P delivered from the receiving cylinder  201  to the sheet conveying drum  210 , is attracted to the surface of the sheet conveying drum  210  due to the suction flows with the front end of the sheet P gripped by the sheet gripper  210   a . The sheet P is conveyed along with movement of the surface of the sheet conveying drum  210 . 
     The ink discharger  220  that discharges inks in four colors of cyan (C), magenta (M), yellow (Y), and black (K) to form an image, includes individual line heads  220 C,  220 M,  220 Y, and  220 K for the ink colors. As long as the line heads  220 C,  220 M,  220 Y, and  220 K each discharge liquid, the configuration of each of the line heads  220 C,  220 M,  220 Y, and  220 K is not limited, and thus any configuration can be adopted. As necessary, provided can be a liquid discharge head that discharges special ink, such as white, gold, or silver in color, or provided can be a liquid discharge head that discharges liquid not to be included in an image, such as surface coating liquid. 
     The line heads  220 C,  220 M,  220 Y, and  220 K of the ink discharger  220  each include a plurality of liquid discharge heads  221  to be described later. The discharge operations of the line heads  220 C,  220 M,  220 Y, and  220 K are each controlled by a drive signal corresponding to image information. When the sheet P conveyed by the sheet conveying drum  210  passes through a region opposed to the ink discharger  220 , the inks for the colors are discharged from the respective lower faces (nozzle faces) of the liquid discharge heads, to form an image corresponding to the image information. The liquid discharge heads  221  can each have a publicly known configuration. Here, the “liquid discharge head” means a functional component that discharges liquid. 
     Note that, in the present embodiment, the image forming device  200  is required at least to have a function of causing liquid to adhere onto a sheet P to form an image, and thus the configuration of discharging liquid or causing adhesion of liquid is not particularly limited. 
     Dryer 
     The dryer  300  includes a drying assembly  301  and a conveying assembly  302 . The drying assembly  301  dries the ink adhering onto the sheet P through the image forming device  200 . The conveying assembly  302  conveys the sheet P conveyed from the image forming device  200 , to the sheet ejector  400  side. That is, after the conveying assembly  302  receives the sheet P conveyed from the image forming device  200 , the conveying assembly  302  conveys the sheet P such that the sheet P passes through the drying assembly  301 , so that the sheet P is delivered to the sheet ejector  400 . When the sheet P passes through the drying assembly  301 , the ink on the sheet P is subjected to drying processing. This arrangement allows the component of liquid, such as moisture, in the ink to evaporate, so that the ink is fastened on the sheet P and additionally the sheet P is inhibited from curling. 
     Sheet Ejector 
     The sheet ejector  400  includes a sheet ejection tray  410  in which a plurality of sheets P is to be loaded. The sheet P conveyed from the dryer  300  by the conveying assembly  302  is piled and retained on the sheet ejection tray  410 , successively. Note that, in the present embodiment, the sheet ejector  400  is required at least to have a function of ejecting a sheet P, and thus the configuration of the sheet ejector  400  is not particularly limited. 
     Other Functional Units 
     Although the inkjet recording apparatus  1  according to the present embodiment includes the sheet feeder  100 , the image forming device  200 , the dryer  300 , and the sheet ejector  400 , other functional units may be appropriately added. For example, a preprocessor that performs preprocessing on image forming, can be added between the sheet feeder  100  and the image forming device  200 , or a postprocessor that performs postprocessing on image forming, can be added between the dryer  300  and the sheet ejector  400 . 
     For example, the preprocessor performs treatment-liquid coating processing of coating a sheet P with treatment liquid that reacts with the ink to inhibit bleed. However, the contents of the preprocessing are not particularly limited. For example, the postprocessor performs sheet-reverse conveying processing of reversing a sheet on which an image is formed by the image forming device  200  and refeeding the sheet to the image forming device  200  to form an image on the other face or processing of binding a plurality of sheets on which an image is formed. Here, the contents of the postprocessing are not particularly limited. 
     Note that, in the present embodiment, the “liquid discharge apparatus” is described exemplarily with the image forming device  200  of the inkjet recording apparatus  1 . However, the “liquid discharge apparatus” is not limited to visualization of a meaningful image, such as a character or a figure, with discharged liquid with a liquid discharge head that discharges liquid to a face to be dried of a sheet material, and thus includes, for example, formation of a pattern having no meaning. 
     The sheet material is not limited in quality, and thus is required at least to include an object to which liquid can adhere temporarily, such as paper, thread, fiber, fabric cloth, leather, metal, plastic, glass, wood, or ceramics. For example, there may be provided an object to be used for a film product, a cloth product, such as clothing, a building material, such as wallpaper or flooring, or a leather product. In the present embodiment, the object to which liquid can adhere temporarily is referred to as the “medium”. 
     The “liquid discharge apparatus” can include not only means involved in feeding, conveyance, and sheet ejection of an object to which liquid can adhere, but also a preprocessing device and a postprocessing device. 
     The “liquid” is not particularly limited, and thus is required at least to have viscosity or surface tension allowing a head to discharge the liquid. Preferably, the viscosity is not greater than 30 mPa·s under ordinary temperature and ordinary pressure or by heating or cooling. 
     More specifically, examples of the “liquid” include solution, suspension, and emulsion each including solvent, such as water or organic solvent, colorant, such as dye or pigment, functional material, such as a polymerizable compound, resin, or surfactant, biocompatible material, such as DNA, amino acid, protein, or calcium, or edible material, such as natural coloring matter. For example, these can be used for inkjet ink or surface treatment liquid. 
     The “liquid discharge apparatus” may be, but is not limited to, an apparatus in which a liquid discharge head and a sheet material move relatively. Specific examples include a serial type apparatus that moves a liquid discharge head and a line type apparatus that does not move a liquid discharge head. 
     The “liquid discharge head” is a functional component that discharges/jets liquid from discharge holes (nozzles). As an energy generation source for discharging liquid, a discharge energy generator can be used, such as a piezoelectric actuator (laminated piezoelectric element or thin-film piezoelectric element), a thermal actuator that employs an electrothermal conversion element, such as a heating resistor, or an electrostatic actuator including a diaphragm and opposed electrodes. However, the discharge energy generator to be used is not limited. 
     Note that, as to be described later, in the present embodiment, arrangement of a plurality of liquid discharge heads in a sheet-width direction (direction orthogonal to the conveyance direction of a sheet P) allows a long liquid discharge head (line head). 
     The “wiping” includes the meaning of cleaning, recovery, cleansing, maintenance, sweeping, and washing. Unless otherwise specified, these words are treated as a synonym. 
       FIGS. 2 and 3  are intended for describing the configuration of a wiping-unit neighborhood.  FIG. 2  is a main plan view of the image forming device  200  before rail members  790  move in the sheet-width direction.  FIG. 3  is a main plan view of the image forming device  200  after the rail members  790  move in the sheet-width direction. 
     In  FIG. 2 , the line head  220 C that discharges the ink for cyan includes first to eighth liquid discharge heads  221   a  to  221   h  along the sheet-width direction (direction orthogonal to the conveyance direction of a sheet P). In the following descriptions, in a case where the first to eighth liquid discharge heads  221   a  to  221   h  are not distinguished mutually, each is referred to as the “liquid discharge head  221 ”. The line heads for the other colors each have a similar configuration. In the present embodiment, the eight first to eighth liquid discharge heads  221   a  to  221   h  are disposed in arrangement, but the number of liquid discharge heads  221  is not limited. In the present embodiment, the arrangement of the liquid discharge heads  221  has a staggered pattern, but the arrangement is not limited to this. 
     A wiping assembly  70  is disposed outside the line heads  220 C,  220 M,  220 Y, and  220 K in the sheet-width direction. The wiping assembly  70  mainly includes wiping units  700 C,  700 M,  700 Y, and  700 K corresponding to the line heads  220 C,  220 M,  220 Y, and  220 K for the colors (hereinafter, unless otherwise specified, each referred to as a wiping unit  700 ) and the rail members  790 . 
     Each wiping unit  700  including at least a wiping member including a web, moves along the arrangement direction of the plurality of liquid discharge heads  221 , to wipe a stain on the nozzle face of a liquid discharge head  221  with the wiping member in contact with the liquid discharge head  221 . Each wiping unit  700  is provided at an end portion of the rail member  790 . As illustrated in  FIG. 3 , movement of the rail members  790  in the sheet-width direction moves the wiping units  700 , so that each wiping unit  700  can wipe a stain on the nozzle face of a liquid discharge head  221  with the wiping member of the wiping unit  700  in contact with the liquid discharge head  221 . 
     Note that, in the present embodiment, the liquid discharge heads  221  are in the staggered arrangement. Each line head (hereinafter, denoted with reference numeral  220 ) included in the ink discharger  220 , includes a train of first to fourth liquid discharge heads  221   a ,  221   b ,  221   c , and  221   d  and a train of fifth to eighth liquid discharge heads  221   e ,  221   f ,  221   g , and  221   h . According to the present embodiment, the plurality of wiping units  700  is provided corresponding to the head trains. That is, in the present embodiment, two wiping units  700  individually corresponding to two head trains are provided at each line head. However, the present embodiment is not limited to this, for example, one wiping unit  700  can wipe two head trains, collectively. 
       FIGS. 4, 5, and 6  are each an explanatory view of the wiping operation of a wiping unit  700 .  FIGS. 4, 5, and 6  illustrate the state before a wiping start, the state during web wiping, and the state during wiper wiping, respectively.  FIGS. 4 to 6  are views of the main of the image forming device  200  viewed in the conveyance direction of a sheet P. 
     As illustrated in  FIGS. 2 and 3 , the wiping unit  700  is disposed outside the ink discharger  220  in the sheet-width direction ( FIG. 4 ). The wiping unit  700  includes two types of cleaning members, namely, a first wiping member  701  and a second wiping member  702 , and a pressing member  703 . The first wiping member  701  includes a sheet-shaped member that wipes the respective nozzle faces  221   a   1  to  221   d   1  or  221   e   1  to  221   h   1  of the liquid discharge heads  221  ( 221   a  to  221   d  or  221   e  to  221   h ). For example, a sheet including an absorbent web is used for the first wiping member  701 . 
     Note that, in a case where the nozzle faces  221   a   1  to  221   h   1  are not distinguished mutually, each is referred to as a “nozzle face  221 - 1 ”. The second wiping member  702  includes an elastic member that wipes the respective nozzle faces  221 - 1  of the liquid discharge heads  221 . For example, a rubber wiper is used as an unabsorbent blade. The pressing member  703  energizes the first wiping member  701  upward, and presses the first wiping member  701  to the nozzle face  221 - 1  of a liquid discharge head  221 . 
     Then, as illustrated in  FIG. 5 , movement of the wiping unit  700  in the sheet-width direction makes the first wiping member  701  included in the wiping unit  700 , in contact with the first liquid discharge head  221   a , so that the nozzle face  221   a   1  of the first liquid discharge head  221   a  can be wiped. Similarly, the nozzle faces  221   b   1  to  221   h   1  of the second to eighth liquid discharge heads  221   b  to  221   h  are wiped. Next, as illustrated in  FIG. 6 , the first wiping member  701  moves to a retraction position and the second wiping member  702  moves to a wiping position. The movements result in switching between the first wiping member  701  and the second wiping member  702 . 
     Then, movement of the wiping unit  700  in the sheet-width direction (direction orthogonal to the sheet conveyance direction) makes the second wiping member  702  included in the wiping unit  700 , in contact with the first liquid discharge head  221   a , so that the nozzle face  221   a   1  of the first liquid discharge head  221   a  can be wiped. Similarly, the nozzle faces  221   b   1  to  221   h   1  of the second to eighth liquid discharge heads  221   b  to  221   h  are wiped. The movement of the wiping unit  700  in the sheet-width direction is performed by a sheet-width-direction movement drive assembly and a wiping-unit movement motor  552 . The control of the sheet-width-direction movement drive assembly and the wiping-unit movement motor  552  is performed through a central processing unit (CPU)  510  and a fourth motor controller  544  to be described later. 
     In this case, movements of both of the first wiping member  701  and the second wiping member  702  to the wiping positions, enable simultaneous wiping of a nozzle face  221 - 1 . However, for one ink discharger  220  including a plurality of liquid discharge heads  221  arranged, there is a possibility that the first wiping member  701  and the second wiping member  702  come in contact with the liquid discharge heads  221  in front of and behind a head to be wiped. Contact of a wiping member with a liquid discharge head  221  not to be wiped, causes a stain on the nozzle face  221 - 1  unexpectedly, or trouble, such as a fault in discharging. Thus, the first wiping member  701  and the second wiping member  702  each require individual wiping operation. 
       FIGS. 7 and 8  are explanatory schematic views of the configuration of a wiping unit  700  that drives a first wiping member  701  and a second wiping member  702 , separately.  FIGS. 9 and 10  are explanatory schematic views of the configuration of a wiping unit  700  according to the present embodiment that drives a first wiping member  701  and a second wiping member  702  with a common (shared) drive source.  FIGS. 7 and 9  each illustrate the state when the first wiping member  701  wipes a nozzle face  221 - 1 .  FIGS. 8 and 10  each illustrate the state when the second wiping member  702  wipes the nozzle face  221 - 1 . 
     The first wiping member  701  includes a sheet-shaped member that wipes a nozzle face  221 - 1 . For example, a sheet, such as a web, is used for the first wiping member  701 . The second wiping member  702  includes an elastic member that wipes a nozzle face  221 - 1 . For example, a rubber wiper is used for the second wiping member  702 . In order to distinguish the two clearly, the first wiping member  701  and the second wiping member  702  will be described below as a web  701  and a wiper  702 , respectively. 
     In  FIG. 7 , the web  701  is stretched between a feeding roll  705  and a reeling roll  706 . A first conveying roller  704   a  and a second conveying roller  704   b  in pairs are disposed on both sides of a pressing member  703  as the center between the feeding roll  705  and the reeling roll  706 . With this configuration, a reeling motor  707  drives the reeling roll  706  to reel and convey the web  701  from the feeding roll  705  into the reeling roll  706  through the first conveying roller  704   a , the pressing member  703 , and the second conveying roller  704   b . This operation enables constant supply of the new face of the web  701  onto the upper portion of the pressing member  703 , so that the nozzle face  221 - 1  can be wiped with the new face of the web  701 . A compression spring  712  is disposed at the lower portion of the pressing member  703 , the compression spring  712  energizing the web  701  upward. The nozzle face  221 - 1  is wiped by appropriate pressure due to the elastic force of the compression spring  712 . Note that, instead of the compression spring  712 , for example, an elastic member, such as rubber, can be used. 
     The pressing member  703  is capable of elevation operation due to a pressing-member elevation motor  711  in addition to the energization of the compression spring  712 . This elevation operation allows switching of the pressing member  703  between a wiping position at which the web  701  wipes the nozzle face  221 - 1  and a retraction position at which the web  701  is not in contact with the nozzle face  221 - 1 . In the configuration illustrated in  FIG. 7 , the pressing-member elevation motor  711  elevates the pressing member  703  up and down through a first gear drive train  710 . 
     The first gear drive train  710  includes a first drive gear  710   a  at the first stage coupled with the drive shaft of the pressing-member elevation motor  711 , a second intermediate gear  710   b  engaging with the first drive gear  710   a , and a third driven gear  710   c  at the last stage engaging with the second intermediate gear  710   b . The third driven gear  710   c  at the last stage engages with a rack  703   a  disposed at the lower end of the compression spring  712 . The elevation operation of the pressing member  703  is performed in accordance with the rotation direction of third driven gear  710   c . Note that, in the present embodiment, the pressing-member elevation motor  711  and the first gear drive train  710  that elevate the pressing member  703  up and down, are disposed on the reeling roll  706  side with respect to the pressing member  703 . 
     The wiper  702  is coupled with the driving of a wiper rotation motor  709  through a second gear drive train  708 . The wiper  702  can be rotated by the wiper rotation motor  709 . This rotation allows switching of the wiper  702  between a wiping position at which the wiper  702  wipes the nozzle face  221 - 1  and a retraction position at which the wiper  702  is not in contact with the nozzle face  221 - 1 . 
     The second gear drive train  708  includes a second drive gear  708   a  at the first stage coupled with the drive shaft of the wiper rotation motor  709 , a second intermediate gear  708   b  engaging with the second drive gear  708   a , a third intermediate gear  708   c  engaging with the second intermediate gear  708   b , and a wiper rotation shaft  708   d  at the last stage including a second driven gear engaging with the third intermediate gear  708   c . The wiper  702  is rotatable with the wiper rotation shaft  708   d . The wiper  702  is set at the wiping position or the retraction position by rotation of the wiper rotation shaft  708   d.    
     Provision of the two drive sources in this manner, allows individually the switching operation of the pressing member  703  between the wiping position and the retraction position and the switching operation of the wiper  702  between the wiping position and the retraction position. Thus, a wiping member avoids coming in contact with a head not to be wiped. Depending on the state of the nozzle face  221 - 1  or a mode of cleaning, in a case where wiping is performed with only the web  701  or in a case where wiping is performed with only the wiper  702 , for example, a mode of performing wiping with the wiper  702  after wiping with the web  701  or a mode of performing wiping with the web  701  after wiping with the wiper  702  selectively operates. 
     The example in which the two drive sources, namely, the wiper rotation motor  709  performs the switching operation of the wiper  702  between the wiping position and the retraction position and the pressing-member elevation motor  711  performs the switching operation of the pressing member  703  between the wiping position and the retraction position, has been given above, corresponding to the present embodiment. 
     In contrast to this, according to the present embodiment, a common wiping switching motor  715  performs the switching operation of the wiper  702  between a wiping position and a retraction position and the switching operation of the pressing member  703  between a wiping position and a retraction position, to wipe the nozzle face  221 - 1 . 
     In  FIG. 9 , the wiping switching motor  715  couples driving with the wiper  702  through a second gear drive train  708 . Furthermore, a wiper rotation shaft  708   d  couples the driving with a camshaft (hereinafter, referred to as a first camshaft)  714   b  of a pressing-member elevation cam  714  through a timing belt  713 . The ratio between the turn of the wiper  702  and the rotation of the first camshaft  714   b  of the pressing-member elevation cam  714 , is one to one. A turn of 90° of the wiper  702  by the wiping switching motor  715  rotates the pressing-member elevation cam  714  by 90° in synchronization as illustrated in  FIG. 10 . The pressing-member elevation cam  714  has a cam groove (hereinafter, referred to as a first cam groove)  714   a . A protrusion (hereinafter, referred to as a first protrusion)  716   a  provided in a pressing-member holder  716  is inserted in the first cam groove  714   a  or is engaged with the first cam groove  714   a , so that the first protrusion  716   a  functions as a cam follower. Note that the driving of the wiping switching motor  715  is controlled by the CPU  510  and a first motor controller  541  in control circuitry  500  to be described later. 
     The pressing-member holder  716  is guided movably only upward and downward. The pressing-member holder  716  descends in response to the trajectory of the first protrusion  716   a  moving along the first cam groove  714   a  of the pressing-member elevation cam  714  rotating, resulting in movement of the pressing member  703  to the retraction position. In the configuration illustrated in  FIGS. 9 and 10 , rotation of the pressing-member elevation cam  714  by 90° from the position of  FIG. 9 , causes the pressing member  703  to descend and move to the retraction position illustrated in  FIG. 10 . 
     The ratio between the turn of the wiper  702  and the rotation of the pressing-member elevation cam  714 , is not necessarily one to one, and thus can be flexibly set meeting the shape of the pressing-member elevation cam  714 , on the basis of the convenience of layout or a desirable operation pattern. In the configuration illustrated in  FIGS. 9 and 10 , the wiper rotation shaft  708   d  couples driving with the first camshaft  714   b  of the pressing-member elevation cam  714  through the timing belt  713 . However, instead of the timing belt  713 , for example, a gear or a wire capable of driving coupling, can be applied. Note that the configuration of the second gear drive train  708  is the same as the configuration described with reference to  FIG. 7 . 
     The configuration in this manner does not require the pressing-member elevation motor  711 , the first gear drive train  710 , and the rack  703   a  illustrated in  FIGS. 7 and 8 , so that the wiping switching motor  715  is provided as a common drive source. As a result, the number of components can be reduced, so that a reduction in costs and miniaturization of an apparatus can be achieved. The web  701  and the wiper  702  wipe the nozzle face  221 - 1 , so that cleaning effect improves. 
     According to the present embodiment, driving the wiping switching motor  715  as the drive source causes the wiper rotation shaft  708   d  as a first rotary body to be driven in synchronization with the pressing-member holder  716 . Accordingly, the linear motion of the first wiping member  701  and the rotational motion of the second wiping member  702  can be synchronously executed with a simple configuration. 
     Second Embodiment 
       FIGS. 11 to 13  are explanatory schematic views of the configuration of a wiping unit  700  according to a second embodiment that drives a web  701  and a wiper  702  with one drive source. 
     According to the first embodiment illustrated in  FIGS. 9 and 10 , the rotation allows the wiper  702  to switch between the wiping position and the retraction position, and the elevation allows the pressing member  703  to switch between the wiping position and the retraction position. In contrast to this, the wiper  702  may perform elevation, and the pressing member  703  may perform rotation. Alternatively, the wiper  702  and a pressing member  703  may each perform elevation operation as illustrated in  FIGS. 11 to 13 . These can be flexibly selected depending on layout circumstances. Thus, according to the second embodiment, a wiper elevation cam  717  performs the elevation operation of the wiper  702 , and a pressing-member elevation cam  714  performs the elevation operation of the pressing member  703 . 
     As illustrated in  FIG. 11 , according to the second embodiment, a camshaft (hereinafter, referred to as a second camshaft)  717   b  of the wiper elevation cam  717  is used, instead of the wiper rotation shaft  708   d  in the first embodiment. The second camshaft  717   b  functions as a second driven gear, similarly to the first embodiment, and couples driving with a first camshaft  714   b  of the pressing-member elevation cam  714  through the timing belt  713 . 
     The wiper elevation cam  717  includes a second cam groove  717   a  and the second camshaft  717   b . The second camshaft  717   b  is the center in rotation of the wiper elevation cam  717 . The wiper elevation cam  717  is integrally secured with the second camshaft  717   b . A wiping switching motor  715  transmits drive force to the second camshaft  717   b  through a second gear drive train  708 . The drive force is further transmitted to the first camshaft  714   b.    
     A wiper holder  718  holds the wiper  702  having an upper portion protruding from the wiper holder  718 . A protrusion (hereinafter, referred to as a second protrusion)  718   a  provided at the lower portion of the wiper holder  718 , is inserted in the second cam groove  717   a  or is engaged with the second cam groove  717   a , so that the second protrusion  718   a  functions as a cam follower. This assembly allows the wiper holder  718  to ascend and descend due to rotation of the wiper elevation cam  717 , resulting in elevation operation of the wiper  702 . For the elevation operation of the pressing member  703 , because a first protrusion  716   a  of a pressing-member holder  716  is inserted in a first cam groove  714   a  of the pressing-member elevation cam  714 , the pressing-member holder  716  ascends and descends in response to rotation of the pressing-member elevation cam  714 , resulting in elevation operation of the pressing member  703 . 
     In this case, depending on the shape of a cam, as illustrated in  FIGS. 12 and 13 , the elevation operation of the wiper  702  and the elevation operation of the pressing member  703  can be individually performed by switching between the normal rotation and the reverse rotation of the wiping switching motor  715 . Switching between the objects that perform elevation operation, by the normal rotation and the reverse rotation, allows change of the speed in rotation of the wiping switching motor  715  between the normal rotation and the reverse rotation, so that the speed of elevation operation of each object can be changed. For example, the rotation speed of the wiping switching motor  715  is changed so as to slow the speed of either the normal rotation or the reverse rotation, whichever is higher in drive load, so that the burden on motor torque can be reduced. Thus, an inexpensive motor can be selected. Increase of the speed of either the normal rotation or the reverse rotation, whichever is smaller in load, can shorten operating time. In the present embodiment, the control of the wiping switching motor  715  is performed by a CPU  510  and a fourth motor controller  544  as to be described later. 
     Note that  FIG. 12  illustrates the state of each constituent element when the wiper  702  descends or moves backward (moves to the retraction position) with the pressing member  703  that has ascended (wiping position). Conversely,  FIG. 13  illustrates the state of each constituent element when the pressing member  703  descends or moves backward (moves to the retraction position) with the wiper  702  that has ascended (wiping position). For the former state, the wiping switching motor  715  rotates counterclockwise as illustrated. For the latter state, the wiping switching motor  715  rotates clockwise as illustrated. Note that the pressing-member elevation cam  714  and the wiper elevation cam  717  are appropriately designed in cam shape and cam size, on the basis of operation. For example, in the present embodiment, cams in the same size and in the same shape are disposed at mutually different angles, so that the pressing-member elevation cam  714  and the wiper elevation cam  717  can be implemented. 
     In terms of assembly, the second camshaft  717   b , the wiper elevation cam  717 , and the wiper  702  held by the wiper holder  718  in the second embodiment are equivalent to the wiper rotation shaft  708   d  and the wiper  702  in the first embodiment. The other constituent elements that have not been described specifically are the same in configuration as the constituent elements according to the first embodiment, and function similarly to the constituent elements according to the first embodiment. 
       FIGS. 14 to 20  are explanatory operation views of the wiping operation of the wiping unit  700  for the nozzle face  221   b   1  of a second liquid discharge head  221   b  in the second embodiment. The second liquid discharge head  221   b  is a head second from the sheet end portion illustrated in  FIG. 2 . The wiping operation will be described below with reference to a block diagram of a control configuration of  FIG. 24  and a flowchart of  FIG. 25 . 
     In a case where the web  701  wipes the nozzle face  221   b   1  of the second liquid discharge head  221   b , first, the pressing member  703  is positioned at a wiping start position for the second liquid discharge head  221   b . The wiping start position is located between the first liquid discharge head  221   a  and the second liquid discharge head  221   b .  FIG. 15  illustrates a wiping completion position at which the pressing member  703  is positioned between the second liquid discharge head  221   b  and the third liquid discharge head  221   c . This state corresponds to a wiping start position for the third liquid discharge head  221   c . Therefore, for the second liquid discharge head  221   b , the state where the pressing member  703  is positioned between the first liquid discharge head  221   a  and the second liquid discharge head  221   b , corresponds to the wiping start position for the second liquid discharge head  221   b.    
     In this state, the ink discharger  220  has retracted in the arrow A 2  direction. The wiping switching motor  715  rotates normally (rotates in a previously set one direction) such that the pressing member  703  is positioned at the wiping position and the wiper  702  is positioned at the retraction position. After the pressing member  703  is positioned at the wiping position and the wiper  702  is positioned at the retraction position due to this normal-rotation operation, the wiping switching motor  715  stops rotating due to the control of the CPU  510 . 
     Then, for wiping of the second liquid discharge head  221   b , the CPU  510  first verifies whether the ink discharger  220  has retracted at the retraction position (step S 1 ). When verifying that the ink discharger  220  has retracted (step S 1 : Y), the CPU  510  verifies whether the pressing member  703  is positioned at the wiping start position for the nozzle face  221   b   1  of the second liquid discharge head  221   b  between the first liquid discharge head  221   a  and the second liquid discharge head  221   b  (step S 2 ). 
     When verifying that the pressing member  703  is positioned at the wiping start position (step S 2 : Y), the CPU  510  further verifies whether the pressing member  703  is positioned at the wiping position and the wiper  702  is positioned at the retraction position (step S 3 ), to determine whether wiping is allowable. Note that, on the basis of the rotation angle of the wiping switching motor  715 , the CPU  510  can determine whether the pressing member  703  is positioned at the wiping position and the wiper  702  is positioned at the retraction position. 
     When it is determined that wiping is allowable, a line-head elevation motor  551  drives a line-head elevation assembly to cause the ink discharger  220  to descend to the wiping position (step S 4 : corresponding to the arrow A 1  direction). The line-head elevation assembly is an assembly to be driven by the CPU  510  through a motor controller  543 . The elevation assembly itself can be appropriately provided by a person skilled in the art with a cam or a gear, and thus the detailed description of the elevation assembly will be omitted. 
     When the ink discharger  220  descends to the wiping position (step S 5 : Y), a wiping-unit movement motor  552  drives a sheet-width-direction movement drive assembly to move the wiping unit  700  in the sheet width direction (arrow B 1  direction) (step S 6 ). The sheet-width-direction movement drive assembly is an assembly to be driven by the CPU  510  through the motor controller  544 . Similarly to the elevation assembly, the movement drive assembly itself can be appropriately provided by a person skilled in the art with a cam or a gear, and thus the detailed description of the movement drive assembly will be omitted. 
       FIG. 14  illustrates the movement state in the wiping direction, namely, in the arrow B 1  direction of the pressing member  703  at step S 6 . As illustrated in  FIG. 14 , the wiping unit  700  moves in the arrow B 1  direction with the web  701  in contact with or pressing against the nozzle face  221   b   1  of the second liquid discharge head  221   b . Thus, the wiping unit  700  moves with the web  701  in contact with the nozzle face  221   b   1  due to the pressing member  703 , to wipe the nozzle face  221   b   1 . At this time, because the wiper  702  is positioned at the retraction position at which the wiper  702  is not in contact with the first liquid discharge head  221   a , only the web  701  wipes the nozzle face  221   b   1 . 
     After the pressing member  703  moves to the end portion of the nozzle face  221   b   1  of the second liquid discharge head  221   b  and the wiping with the web  701  is completed (step S 7 : Y), as illustrated in  FIG. 15 , the pressing member  703  is positioned between the second liquid discharge head  221   b  and the third liquid discharge head  221   c . After this state, the ink discharger  220  ascends (arrow A 2  direction) and moves to the retraction position spaced apart from the pressing member  703  by a predetermined distance (step S 8 ). 
     As illustrated in  FIG. 15 , when the pressing member  703  arrives at a position at which the wiping of the nozzle face  221   b   1  of the second liquid discharge head  221   b  is completed, the wiper  702  is positioned being opposed to the second liquid discharge head  221   b . That is the wiper  702  is positioned slightly on the third liquid discharge head  221   c  side with respect to the end portion on the first liquid discharge head  221   a  side of the second liquid discharge head  221   b . Thus, if the wiper  702  starts wiping operation in this state, an unwiped area occurs. 
     Therefore, as illustrated in  FIGS. 15 and 16 , the wiper  702  is moved backward to a position corresponding to the wiping start position of the pressing member  703  to the second liquid discharge head  221   b . That is the wiping-unit movement motor  552  is driven to move the wiping unit  700  in the arrow B 2  direction from the position illustrated in  FIG. 15  to the position illustrated in  FIG. 16  (step S 9 ). 
     Then, the wiping switching motor  715  rotates by a predetermined angle in the opposite direction to the direction in which the state of  FIG. 14  is acquired (step S 10 ), to position the wiper  702  at the wiping position and the pressing member  703  at the retraction position (step S 11 : Y). From this state, the line-head elevation motor  551  is driven to cause the ink discharger  220  to descend (move) to the wiping position (step S 12 ). After the ink discharger  220  moves to the wiping position, as illustrated in  FIG. 16 , the wiper  702  protrudes between the first liquid discharge head  221   a  and the second liquid discharge head  221   b , and the pressing member  703  has moved backward to a position at which the pressing member  703  is not in contact with the nozzle face  221   b   1 . This position is the wiping start position of the wiper  702 . 
     When the wiper  702  is positioned at the wiping start position (step S 13 : Y), as illustrated in  FIG. 17 , the wiping-unit movement motor  552  is driven to move the wiping unit  700  in the arrow B 1  direction (step S 14 ). At this time, the wiper  702  deforms elastically in contact with the nozzle face  221   b   1 . Thus, the nozzle face  221   b   1  is wiped along with the movement of the wiping unit  700 , so that cleaning with the wiper  702  is performed to the nozzle face  221   b   1 . 
     After the wiper  702  moves to the end portion of the nozzle face  221   b   1  of the second liquid discharge head  221   b  and then the wiping is completed with the wiper  702  (step S 15 : Y), as illustrated in  FIG. 18 , the wiper  702  is positioned between the second liquid discharge head  221   b  and the third liquid discharge head  221   c . After this state, the ink discharger  220  ascends (arrow A 2  direction) and move to the retraction position spaced apart from the pressing member  703  by the predetermined distance (step S 16 ), so that the cleaning of the nozzle face  221   b   1  of the second liquid discharge head  221   b  finishes. 
     Operation similar to the operation to the second liquid discharge head  221   b , is repeated for the first liquid discharge head  221   a  and the third to eighth liquid discharge heads  221   c  to  221   h , to perform cleaning to the ink discharger  220 . 
     As illustrated in  FIGS. 19 and 20 , the wiping directions of the web  701  and the wiper  702  may be different from each other. In  FIG. 19 , the wiping direction of the web  701  to the nozzle face  221   b   1  of the second liquid discharge head  221   b  is in the arrow B 2  direction. In  FIG. 20 , the wiping direction of the wiper  702  to the nozzle face  221   b   1  of the second liquid discharge head  221   b  is in the arrow B 1  direction. That is, depending on the positional relationship between the pressing member  703  and the wiper  702  or the positional relationship between the liquid discharge heads  221 , there is a possibility that wiping in different directions as indicated with the arrow B 1  direction and the arrow B 2  direction can shorten operating time. Unidirectionally wiping or multidirectionally wiping may be appropriately selected in consideration of operating time depending on layout circumstances. 
     Note that the wiping operation to the nozzle face  221   b   1  of the second liquid discharge head  221   b  has been described above. The nozzle face  221   a   1  of the first liquid discharge head  221   a  and the nozzle faces  221   c   1  to  221   h   1  of the third to eighth liquid discharge heads  221   c  to  221   h , are wiped with similar operation. Cleaning of the nozzle faces  221   a   1  to  221   h   1  is performed in this manner. 
     The other constituent elements that have not been described specifically are similar in configuration to the constituent elements according to the first embodiment, and function similarly to the constituent elements according to the first embodiment. 
     According to the present embodiment, driving the wiping switching motor  715  as the drive source causes the wiper holder  718  and the pressing-member holder  716  to driven in synchronization with each other. Accordingly, the linear motion of the first wiping member  701  and the linear motion of the second wiping member  702  can be synchronously executed with a simple configuration. 
     Third Embodiment 
     In the second embodiment, in a case where the pressing member  703  is at the wiping position, the web  701  has been energized upward by a compression spring  712  disposed at the lower portion of the pressing member  703 . When the pressing member  703  moves from the wiping position to the retraction position, as indicated with a solid line in the explanatory view of  FIG. 21  illustrating the movement operation of the web  701 , the web  701  moves downward from the dotted-line position to the retraction position due to its own weight. At this time, there is a possibility that, regardless of the movement of the pressing member  703  to the retraction position, the web  701  stays at the wiping position indicated with the dotted line in the figure and does not move downward. 
     For example, when ink adhering to the web  701  dries after the web  701  wipes the nozzle face  221 - 1 , as can be understood from the explanatory view of  FIG. 22  illustrating that the web  701  stays at the wiping position, there is a possibility that solidification of the web  701  causes the web  701  to stay in the shape in which the pressing member  703  is at the wiping position. This state causes the web  701  to come in contact with a liquid discharge head  221  not to be wiped even when the pressing member  703  is at the retraction position, resulting in a stain on the nozzle face  221 - 1  or a fault in discharging. 
     In order to solve the problem, use of a configuration in which the web  701  is sandwiched from above and below by the pressing member  703 , enables the web  701  to follow the pressing member  703  along with movement of the pressing member  703 . However, the web  701  performs wiping while being pressed against the nozzle face  221 - 1 . Thus, disposition of a component on the upper side of the web  701  causes the component to come in contact with the nozzle face  221 - 1 , resulting in damage of the nozzle face  221 - 1 . Therefore, the configuration in which the web  701  is sandwiched from above and below by the pressing member  703 , cannot be adopted. 
     Thus, according to a third embodiment, a web  701  retracts reliably along with retraction operation of a pressing member  703 .  FIG. 23  is an explanatory operation view of an operation of retracting the web  701  more reliably so that the web  701  does not come in contact with a liquid discharge head  221 , in the third embodiment. 
     According to the present embodiment, as illustrated in  FIG. 23 , after movement of the pressing member  703  to a retraction position, a CPU  510  operates a reeling motor  707  to perform reeling by the amount of slack of the web  701  caused by the movement of the pressing member  703 . This arrangement enables the web  701  to descend reliably to the retraction position of the pressing member  703 . The timing at which the reeling motor  707  performs reeling on the web  701 , is not necessarily after movement of the pressing member  703  to the retraction position, and thus may be the same as the timing at which the pressing member  703  starts to move to the retraction position. 
     Conversely, when the pressing member  703  moves from the retraction position to a wiping position, the CPU  510  rotates the reeling motor  707  reversely and makes slack to the web  701  to move the pressing member  703  to the wiping position. This arrangement enables a reduction in load when the pressing member  703  moves from the retraction position to the wiping position, so that the pressing member  703  can move reliably to the wiping position. 
     The other constituent elements that have not been described specifically are similar in configuration to the constituent elements according to the first and second embodiments, and function similarly to the constituent elements according to the first and second embodiments. 
     Note that, in the first to third embodiments, control circuitry  500  included in an image forming device  200  performs the control of each constituent element.  FIG. 25  is a block diagram of the main of the control circuitry  500 . The control circuitry  500  controls, for example, the driving of a wiping switching motor  715 , the liquid discharging of liquid discharge heads  221 , the proximity and separation operation of the liquid discharge heads  221  to wiping units  700 , the movement of the wiping units  700  along the nozzle faces  221 - 1  of the liquid discharge heads  221 . 
     The control circuitry  500  includes: a control subject including a CPU  510 , a read only memory (ROM)  520 , and a random access memory (RAM)  530 ; control objects to be controlled; and a communication interface. The constituent elements are electrically mutually connected through a bus line, such as an address bus or a data bus. 
     In the present embodiment, the control objects include a wiping switching motor  715 , a reeling motor  707 , a line-head elevation motor  551 , a wiping-unit movement motor  552 , and a liquid-discharge-head drive unit  553 . The control objects are controlled through first to fourth motor controllers  541 ,  542 ,  543 , and  544 , and a head controller  545 . The line-head elevation motor  551  is a motor that drives a line-head elevation drive assembly that moves the ink discharger  220  indicated with the arrows A 1  and A 2  in the figures to the wiping position and the retraction position. The wiping-unit movement motor  552  is a motor that drives a wiping-unit drive assembly that moves the wiping unit  700  indicated with the arrows B 1  and B 2  in the figures parallel in the arrangement direction of the liquid discharge heads  221  of the ink discharger  220 . The head controller  545  is used to control head energization and liquid discharging in the liquid-discharge-head drive unit  553 . 
     The CPU  510  executes a computer readable program stored in the ROM  520 , to control a sheet feeder  100 , an image forming device  200 , a dryer  300 , and a sheet ejector  400 . The ROM  520  stores data or the program to be executed by the CPU  510 . The RAM  530  stores the data temporarily when the CPU  510  executes the program. 
     Correspondence of the present disclosure to each embodiment allows achievement of the following effects. Note that, in the following descriptions, the constituent elements in each embodiment correspond to the constituent elements in the scope of the claims. For different terms between the two, the terms in the latter are indicated with brackets, and the corresponding reference signs are given, so that the correspondence relationship between the two is clarified. 
     (1) The head cleaning device (wiping unit  700 ) according to the first or second embodiment includes: a web  701  (first wiping member) that wipes a nozzle face  221 - 1  of each of a plurality of liquid discharge heads  221 ; the second gear drive train  708 , the timing belt  713 , and the pressing-member elevation cam  714  (first drive mechanism) that move the web  701  to the wiping position at which the web  701  wipes the nozzle face  221 - 1  or the retraction position spaced apart from the nozzle face  221 - 1 ; the wiper  702  (second wiping member) that wipes the nozzle face  221 - 1 ; the second gear drive train  708 , the wiper rotation shaft  708   d  or the wiper elevation cam  717  (second drive mechanism) that move the wiper  702  to the wiping position at which the wiper  702  wipes the nozzle face  221 - 1  or the retraction position spaced apart from the nozzle face  221 - 1 ; the wiping switching motor  715  (common drive source) that drives the first drive mechanism and the second drive mechanism; and the CPU  510  (controller) that controls the wiping switching motor  715  (common drive source). Thus, control of the driving of the wiping switching motor  715  (common drive source) enables individual movement of each of the web  701  and the wiper  702  to the wiping position or the retraction position. That is, according to the first or second embodiment, one drive source is provided for the respective operations of two types of wiping mechanisms that wipe the nozzle face  221 - 1 , so that a reduction in costs and miniaturization of an apparatus can be achieved. Because the nozzle face  221 - 1  is wiped and cleaned with the two different types of wiping mechanisms, cleaning effect on the nozzle face  221 - 1  can improve. 
     (2) According to the first or second embodiment, the web  701  is a sheet-shaped wiping member to wipe the nozzle face  221 - 1  for cleaning. Such a configuration can enhance the effect of cleaning the nozzle face  221 - 1 . 
     (3) According to the first or second embodiment, the wiping unit  700  (head cleaning device) includes the timing belt  713  (drive-force transmitter) that transmits drive force of the second gear drive train  708  (second drive mechanism) that drives the wiper  702  (second wiping member), to the pressing-member elevation cam  714  (first drive mechanism) that drives the web  701  (first wiping member). The movement of the web  701  (first wiping member) and the movement of the wiper  702  (second wiping member) are performed in synchronization by the wiping switching motor  715  (drive source). Thus, the two can be controlled constantly at the same timing, and the nozzle face  221 - 1  can be wiped reliably with a simple control configuration. 
     (4) According to the first embodiment, the wiping unit  700  (head cleaning device) includes the wiper rotation shaft  708   d  (first rotary body) to be rotated by the wiping switching motor  715 , the pressing-member elevation cam  714  (first eccentric cam) coupled with the wiper rotation shaft  708   d  so that a drive force is transmitted from the wiper rotation shaft  708   d  to the pressing-member elevation cam  714 , and the pressing-member holder  716  (first holder) including a contact portion  716   d  to contact the pressing-member elevation cam  714  and being linearly movable with rotation of the pressing-member elevation cam  714 . The wiper rotation shaft  708   d  holds the wiper  702  (second wiping member) so that the wiper  702  is rotatable. The pressing-member holder  716  holds the web  701  so that the web  701  is linearly movable. Thus, the wiper rotation shaft  708   d  and the pressing-member holder  716  are driven in synchronization with each other by driving of the wiping switching motor  715  as the driving source. Accordingly, the linear motion of the first wiping member (the web  701 ) and the rotational motion of the second wiping member (the wiper  702 ) can be synchronously performed with a simple configuration. 
     (5) According to the second embodiment, the wiping unit  700  (head cleaning device) includes the wiper elevation cam  717  (second eccentric cam), the pressing-member elevation cam  714  (first eccentric cam) coupled with the wiper elevation cam  717  so that a drive force is transmitted from the wiper elevation cam  717  to the pressing-member elevation cam  714 , the wiper holder  718  including the second protrusion  718   a  (second contact portion) to contact the wiper elevation cam  717  and being linearly movable with rotation of the wiper elevation cam  717 , and the pressing-member holder  716  (first holder) including the first protrusion  716   a  (first contact portion) to contact the pressing-member elevation cam  714  and being linearly movable with rotation of the wiper elevation cam  717 . The wiper holder  718  (second holder) holds the wiper  702  (second wiping member) so that the wiper  702  is linearly movable. The pressing-member holder  716  holds the web  701  (first wiping member) so that the web  701  is linearly movable. Thus, the wiper holder  718  and the pressing-member holder  716  are driven in synchronization with each other by driving of the wiping switching motor  715 . Accordingly, the linear motion of the web  701  and the linear motion of the wiper  702  can be synchronously performed with a simple configuration. 
     (6) According to the first or second embodiment, the second gear drive train  708 , the timing belt  713 , and the pressing-member elevation cam  714  (first drive mechanism) move the web  701  (first wiping member) by a linear motion of the pressing-member holder  716  due to the pressing-member elevation cam  714 , and the second gear drive train  708 , the wiper rotation shaft  708   d , or the wiper elevation cam  717  (second drive mechanism) move the wiper  702  (second wiping member) by a circular motion or a linear motion. Thus, the web  701  (first wiping member) and the wiper  702  (second wiping member) can be each moved to the wiping position or the retraction position by the single wiping switching motor  715  (single drive source). In that case, depending on an object to be wiped, movement by the circular motion or movement by the linear motion can be appropriately set for the wiper  702  (second wiping member). 
     (7) According to the second embodiment, the linear motions in (6) are each performed vertically to the nozzle face  221 - 1  by the pressing-member elevation cam  714  or the wiper elevation cam  717  (cam assembly). Thus, movement can be performed between the wiping position and the retraction position even in a narrow space, resulting in contribution to miniaturization of an apparatus. 
     (8) According to the second embodiment, the movement of the web  701  (first wiping member) and the movement of the wiper  702  (second wiping member) are performed by normal rotation or reverse rotation of the wiping switching motor  715  (drive source). Thus, control of the drive direction of the wiping switching motor  715  enables the movement of the web  701  and the movement of the wiper  702 . Speed can be changed between the normal rotation and the reverse rotation, so that variation can be expanded in control. 
     (9) According to the second embodiment, the wiping switching motor  715  (drive source) changes in speed between the normal rotation and the reverse rotation. Thus, control corresponding to the loads of the first drive mechanism and the second drive mechanism, can be performed. For example, slowing the rotation higher in load causes the burden of motor torque to decrease, so that an inexpensive motor can be selected. 
     (10) According to the first or second embodiment, a first wiping operation of wiping the nozzle face  221 - 1  with either the web  701  (first wiping member) or the wiper  702  (second wiping member) is performed, and a second wiping operation of wiping the nozzle face  221 - 1  with another wiping member after the first wiping operation is performed. Thus, wiping is performed twice to the same nozzle face  221 - 1 . This arrangement enables improvement in wiping efficiency. 
     (11) According to the second embodiment, in (10), the first wiping operation and the second wiping operation are different in wiping direction. Thus, one round trip enables wiping twice, so that wiping time can shorten. 
     (12) According to the first or second embodiment, the web  701  that is the first wiping member has absorbency, and the wiper  702  (blade) that is the second wiping member has no absorbency. Thus, different wiping effects can be acquired with wiping members having different properties. 
     (13) According to the third embodiment, the wiping unit  700  (head cleaning device) includes a pressing member  703  that moves a web  701  (first wiping member) to a wiping position to press the web  701  against a nozzle face  221 - 1 ; and a reeling roll  706  and a reeling motor  707  that move the web  701  (first wiping member) along the pressing member  703 . Simultaneously with or immediately after the pressing member  703  completes movement of the web  701  from the wiping position to the retraction position, the reeling motor  707  and the reeling roll  706  (conveying member) reels in the web  701  (first wiping member) to start conveyance of the web  701 . Thus, the web  701  can be reliably retracted. 
     (14) According to the third embodiment, in (13), the reeling motor  707  and the reeling roll  706  (conveying member) reel back the web  701  to make slack to the web  701 , before the pressing member  703  comes in contact with the web  701  (first wiping member) during movement of the pressing member  703  from the retraction position to the wiping position. Thus, the pressing member  703  can move reliably to the wiping position. 
     (15) An image forming device  200  (liquid discharge apparatus) includes the head cleaning device described in any of (1) to (14). Thus, an image forming device having the effect described in any of (1) to (14) and furthermore an image forming system including the image forming device, can be provided. 
     Note that embodiments of the present disclosure are not limited to the embodiments described above. Various modifications can be made without departing from the scope of the gist of the present disclosure. The present disclosure includes all technical matters included in the technical idea described in the scope of the claims. The embodiments are preferred exemplifications. A person skilled in the art can implement various alternatives, alternations, modifications, or improvements from the contents disclosed in the present specification, and these are to be included in the technical scope described in the scope of the accompanying claims. 
     Any one of the above-described operations may be performed in various other ways, for example, in an order different from the one described above. 
     Each of the functions of the described embodiments may be implemented by one or more processing circuits or circuitry. Processing circuitry includes a programmed processor, as a processor includes circuitry. A processing circuit also includes devices such as an application specific integrated circuit (ASIC), digital signal processor (DSP), field programmable gate array (FPGA), and conventional circuit components arranged to perform the recited functions.