Patent Publication Number: US-8967755-B2

Title: Image forming apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application is based on and claims priority pursuant to 35 U.S.C. §119 to Japanese Patent Application No. 2012-167775, filed on Jul. 27, 2012, in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein. 
     BACKGROUND 
     1. Technical Field 
     This disclosure relates to an image forming apparatus and an image forming method, and more specifically to an image forming apparatus and method of forming an image on a print medium having an adhesive face. 
     2. Description of the Related Art 
     Image forming apparatuses are used as printers, facsimile machines, copiers, plotters, or multi-functional devices having, e.g., two or more of the foregoing capabilities. As one type of image forming apparatuses, for example, an image forming apparatus, such as a label printer, is known that prints a print medium having an adhesive face with no separation sheet mounted thereon, such as a label sheet having no tape or mount sheet, (hereinafter, also referred to as “linerless label sheet”) and cuts the print medium to a desired length after printing to form a print medium piece (hereinafter, “label piece”). 
     For such an image forming apparatus, an adhesive face of the label piece is exposed after cutting. As a result, the label piece may be adhered to another label piece or an operator&#39;s hand or cloth, thus resulting in a reduced adhesion or an unavailable defective label. 
     Hence, a stacker apparatus like that described in JP-2003-146318-A is proposed for adhesive labels having no mounts. The adhesive label has a separation-processed print portion on the front face side and an adhesive portion on the back face side. The stacker apparatus includes a cutter section for cutting the adhesive label into label pieces, a conveyance section to convey the label pieces cut by the cutter section, a cylindrical rotary member rotatably disposed at a downstream side of the conveyance section to rotate while temporality adhering the label pieces discharged from a conveyance means to an outer surface of the rotary member, and a biasing means to urge the label pieces discharged from the conveyance section, from the front face side toward the rotary member. 
     Alternatively, another stacker device like that described in JP-2004-059310-A is proposed for adhesive labels having no mounts. The stacker device includes a conveyance means for conveying and discharging a label piece cut at a cutter portion and a label receiving stand portion having a disk-like rotation member that is placed rotatably and substantially in a horizontal state on a downstream side of the conveyance means and that rotates while making the label piece discharged from the conveyance means temporarily stick on its non-adhesive processed surface. 
     However, for such a configuration described in JP-2003-146318-A or JP-2004-059310-A, label pieces discharged are (temporarily) adhered to a rotary (rotation) member and stacked on the rotary member. The inventors have recognized that such a configuration results in an increased size of the apparatus. In addition, since label pieces are once adhered to another member (rotary member), the adhesive force of label pieces is reduced. 
     BRIEF SUMMARY 
     In at least one exemplary embodiment of this disclosure, there is provided an image forming apparatus including an apparatus body, a print medium, a conveyance unit, an image forming unit, a cutter unit, a holding unit, a sensor, and a controller. The print medium is installed to the apparatus body. The print medium has an adhesive face with no separation sheet mounted on the adhesive face. The conveyance unit conveys the print medium. The image forming unit forms an image on the print medium conveyed by the conveyance unit. The cutter unit cuts the print medium having the image formed thereon into a print medium piece of a desired length. The holding unit is disposed downstream from the cutter unit in a conveyance direction in which the print medium is conveyed. The holding unit is configured to hold the print medium piece in a state in which the print medium piece is drawable from outside of the apparatus body. The holding unit has a surface separatable from an adhesive face of the print medium piece to hold the adhesive face of the print medium piece. The sensor detects presence or absence of the print medium piece held by the holding unit. After the sensor detects that the print medium piece held by the holding unit is drawn out, the controller controls the conveyance unit to convey the print medium to the holding unit and controls the holding unit to hold the print medium. 
     In at least one exemplary embodiment of this disclosure, there is provided an image forming apparatus including an apparatus body, a print medium, conveyance means, image forming means, cutting means, holding means, detection means, and control means. The print medium is installed in the apparatus body. The print medium has an adhesive face with no separation sheet mounted on the adhesive face. The conveyance means conveys the print medium. The image forming means forms an image on the print medium conveyed by the conveyance means. The cutting means cuts the print medium having the image formed thereon into a print medium piece of a desired length. The holding means holds the print medium piece in a state in which the print medium piece is drawable from outside of the apparatus body. The detection means detects presence or absence of the print medium piece held by the holding means. After the detection means detects that the print medium piece held by the holding means is drawn out, the control means controls the conveyance means to convey the print medium to the holding means and control the holding means to hold the print medium. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The aforementioned and other aspects, features, and advantages of the present disclosure would be better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
         FIG. 1  is a side view of a configuration of an image forming apparatus according to a first exemplary embodiment of this disclosure; 
         FIG. 2  is a plan view of the image forming apparatus of  FIG. 1 ; 
         FIGS. 3A and 3B  are side views of a portion of the image forming apparatus of FIG. 
         FIG. 4  is a side view of an output unit of the image forming apparatus of  FIG. 1 ; 
         FIG. 5  is a front view of the output unit of  FIG. 4 ; 
         FIG. 6  is a block diagram of a controller of the image forming apparatus of  FIG. 1 ; 
         FIG. 7  is a flowchart of a procedure of printing control performed by the controller; 
         FIG. 8A  is a side view of an output unit according to a comparative example 1; 
         FIG. 8B  is a side view of an output unit according to a comparative example 2; 
         FIG. 9  is a side view of an output unit according to a second exemplary embodiment of this disclosure; 
         FIG. 10  is a side view of an output unit according to a third exemplary embodiment of this disclosure; 
         FIG. 11  is a side view of an output unit according to a fourth exemplary embodiment of this disclosure; 
         FIG. 12  is a side view of an output unit according to a fifth exemplary embodiment of this disclosure; and 
         FIG. 13  is a side view of an output unit according to a sixth exemplary embodiment of this disclosure. 
     
    
    
     The accompanying drawings are intended to depict exemplary 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 OF EXEMPLARY EMBODIMENTS 
     In describing embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this patent 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 operate in a similar manner and achieve similar results. 
     The term “image formation” used herein includes providing not only meaningful images, such as characters and figures, but meaningless images, such as patterns, to print media (in other words, the term “image formation” also includes causing liquid droplets to land on print media). 
     The term “ink” is not limited to “ink” in a narrow sense, unless specified, but is used as a generic term for any types of liquid usable as targets of image formation. For example, the term “ink” includes recording liquid, fixing solution, liquid, and so on. 
     The term “image forming apparatus”, unless specified, also includes both serial-type image forming apparatus and line-type image forming apparatus. 
     Although the exemplary embodiments are described with technical limitations with reference to the attached drawings, such description is not intended to limit the scope of the invention and all of the components or elements described in the exemplary embodiments of this disclosure are not necessarily indispensable to the present invention. 
     Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, exemplary embodiments of the present disclosure are described below. 
     First, an image forming apparatus according to a first exemplary embodiment of this disclosure is described with reference to  FIGS. 1 to 5 . 
       FIG. 1  is a side view of an entire configuration of an image forming apparatus  1000  according to a first exemplary embodiment of this disclosure.  FIG. 2  is a plan view of the image forming apparatus  1000  of  FIG. 1 .  FIGS. 3A and 3B  are simplified side views of the image forming apparatus  1000  of  FIG. 1 .  FIG. 4  is a side view of an output unit of the image forming apparatus  1000  of  FIG. 1 .  FIG. 5  is a front view of the output unit of  FIG. 4 . 
     As illustrated in  FIG. 1 , the image forming apparatus  1000  has a feed unit  101  as feeding means, an image forming unit  102  as image forming means, a conveyance unit  103  as conveyance means, and an output unit  104  as output means within an apparatus body  100 . 
     The feed unit  101  has a core member  3  and a media roll  4  formed of a print medium  2  rolled around the core member  3 . The media roll  4  is rotatably supported by media-roll support members  5 . 
     As illustrated in  FIGS. 3A and 3B , the print medium  2  is a continuum having an image-formable medium (hereinafter, “print face”)  2   a  and an adhesive layer (hereinafter, referred to as “adhesive face”)  2   b  formed on a surface of the image-formable medium  2   a . The print medium  2  is rolled around the core member  3  in a state in which a mount sheet (separation sheet or separator) is not adhered to the adhesive face  2   b.    
     The image forming unit  102  includes at least one recording head  11  and a carriage  12 . The recording head  11  is a Liquid ejection head mounted on the carriage  12  to eject liquid droplets onto the print medium  2 . The carriage  12  is supported by guide members  13  and  14  so as to be reciprocally movable along a direction perpendicular to a feed direction of the print medium  2  indicated by an arrow FD in  FIG. 2 . 
     In this exemplary embodiment, the recording head  11  has, for example, two nozzle rows. The image forming unit  102  has two recording heads  11  having four nozzle rows to eject ink droplets of, for example, black (K), cyan (C), magenta (M), and yellow (Y). It is to be noted that the configuration of the recording head is not limited to the above-described configuration but may be, for example, a line-type recording head. 
     The image forming unit  102  is not limited to the above-described type of liquid ejection head but may be any other type of image forming unit to form images in a contact or non-contact manner. 
     The conveyance unit  103  includes a protection belt  21  as a protection member to protect the adhesive face of the print medium  2 . The protection belt  21  is arranged in an endless belt form below the recording heads  11 . In other words, the protection belt  21  is looped around a conveyance roller  22  serving as a rotor and a driven roller  23  so as to be movable for circulation. 
     A first pressing roller  24  is disposed opposing the conveyance roller  22 . A rotor pair (in this exemplary embodiment, a roller pair) of the conveyance roller  22  and the first pressing roller  24  forms a conveyance unit serving as conveyance means to convey the print medium  2  to an image forming region of the recording heads  11  by sandwiching the print medium  2  and the protection belt  21  together. 
     Such a configuration prevents a non-conveyable state due to adherence of the adhesive face  2   b  to a conveyance passage to convey a print medium or an unstable conveyance due to an increased resistance against conveyance of a print medium. 
     The protection belt  21  includes multiple holes  21   a . Within a loop formed by the protection belt  21 , a suction fan  27  is disposed opposing the recording heads  11  of the image forming unit  102 . The suction fan  27  sucks the print medium  2  toward a surface of the protection belt  21  via the holes  21   a . In the above-described configuration, the print medium  2  is adhered onto the protection belt  21  by suction. It is to be noted that the force to adhere the print medium to the protection belt is not limited to suction but, for example, electrostatic force is used to adhere the print medium onto the protection belt. 
     A second pressing roller  25  is disposed downstream from the conveyance roller  22  and upstream from the image forming region of the recording heads  11  in the feed direction FD of the print medium  2  to press the print medium  2  against the protection belt  21 . An intermediate pressing roller  26  is disposed between the first pressing roller  24  and the second pressing roller  25 . Spur rollers  28  are disposed opposing the driven roller  23 . 
     The output unit  104  has a cutter unit  31  as cutting means at a position downward from the recording heads  11  in the feed section of the print medium  2 . The cutter unit  31  includes a cutter  31   a  to cut the print medium  2  to a desired length to form a print medium piece (label piece)  200 . The cutter unit  31  cuts the print medium  2  by moving the cutter  31   a  along a main scanning direction indicated by an arrow MSD in  FIG. 2 . 
     Spur rollers  29  are disposed downstream from the driven roller  23  in the feed direction FD of the print medium  2  to press the print medium  2  when the cutter unit  31  cuts the print medium  2 . In some embodiments, a pressing roller is disposed below the spur rollers  29  to sandwich the print medium  2  by the pressing roller and the spur rollers  29  to more stably press the print medium  2  during cutting of the print medium  2 . In such a configuration, the pressing roller is non-adhesive processed. 
     Output rollers  32  are disposed downstream from the cutter unit  31  in the feed direction FD of the print medium  2 . Spur rollers  33  are disposed opposite the output rollers  32  across the print medium  2  fed from the driven roller  23  and the spur rollers  28 . The output rollers  32  and the spur rollers  33  form an output unit or means also serving as a holding unit or means to feed the label piece  200  formed by cutting of the cutter unit  31  to an output port  105  and hold the label piece  200 . 
     In this exemplary embodiment, surfaces of the output rollers  32  to hold the label piece  200  are, for example, non-adhesive processed so that an adhesive face  2   b  of the label piece  200  is separatable from the surfaces of the output rollers  32 . The non-adhesive process is a process for preventing the adhesive face  2   b  from adhering to the surfaces of the output rollers  32 . In some embodiments, the output rollers  32  include a material facilitating separation from the adhesive face  2   b.    
     As illustrated in  FIG. 5 , the output rollers  32  are disposed at desired spaces in the main scanning direction MSD of  FIG. 2 . The spur rollers  33  held by a roller holder  35  are disposed between the output rollers  32 . 
     Such a configuration in which the output rollers  32  do not directly oppose the spur rollers  33  prevents the adhesive face  2   b  from being directly pressed against the output rollers  32 . In addition, such a configuration reduces adhesion of the adhesive face  2   b  to the output rollers  32  and resistance force in drawing the print medium piece  200  from the output port  105 . 
     The output unit  104  has a sensor  34  serving as detection means to detect at the positions of the output rollers  32  whether the label piece  200  having been cut from the print medium  2  passes. In some embodiments, the sensor  34  optically senses the label piece  200  by detecting, e.g., a reflection light. In some embodiments, the sensor  34  directly senses passing of the label piece  200  by a feeler. 
     For the image forming apparatus having such a configuration, when an image is formed on the print medium  2 , the print medium  2  is drawn from the media roll  4  installed to the feed unit  101 . Meanwhile, the first pressing roller  24  is retracted to a position away from the conveyance roller  22  as indicated by an arrow B in  FIG. 3B . 
     The print medium  2  is passed through a nipping portion between the conveyance roller  22  and the first pressing roller  24 , and the first pressing roller  24  is moved in a direction to press the print medium  2  and the protection belt  21  against the conveyance roller  22  as indicated by an arrow A in  FIG. 3A . As a result, the print medium  2  and the protection belt  21  are sandwiched together between and by the conveyance roller  22  and the first pressing roller  24 . 
     When the conveyance roller  22  is rotated, as illustrated in  FIG. 3A , the print medium  2  is conveyed with the adhesive face  2   b  protected by the protection belt  21 , and a desired image is formed on the print medium  2  by the recording heads  11  of the image forming unit  102 . 
     When the protection belt  21  is separated form the print medium  2  having the image formed, the print medium  2  is conveyed to the output unit  104  and cut at a desired position by the cutter unit  31  to form a print medium piece. The print medium piece is held between the output rollers  32  and the spur rollers  33  serving as the holding unit in a state in which the print medium piece is drawable out from the output port  105  of the apparatus body  100 . 
     Next, an outline of a controller of an image forming apparatus according to at least one exemplary embodiment of this disclosure is described with reference to  FIG. 6   
       FIG. 6  is a block diagram of a controller of an image forming apparatus according to at least one exemplary embodiment of this disclosure. 
     The controller includes, e.g., a main controller  301  serving as control means, a head driving controller  302 , a main-scanning driving unit  303 , a conveyance-roller driving unit  305 , a suction-fan driving unit  307 , a cutter driving unit  309 . 
     The main controller  301  is, e.g., a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), a micro computer, such as an input and output (I/O) unit, a volatile random access memory (VRAM), and an application specific integrated circuit (AMC). 
     Print information  300  is input from a host to the main controller  301 . 
     To form an image on the print medium  2  in accordance with the print information  300 , the main controller  301  controls driving of a conveyance motor  306  via the conveyance-roller driving unit  305  to rotate the conveyance roller  22  to intermittently convey the print medium  2  while drawing the print medium  2  from the media roll  4 . The main controller  301  also controls driving of a main-scanning motor  304  via the main-scanning driving unit  303  to move the carriage  12  for scanning in the main scanning direction. Meanwhile, the main controller  301  controls driving of the recording heads  11  via the head driving controller  302  to eject liquid droplets from the recording heads  11 . 
     When the conveyance roller  22  is rotated to convey the print medium  2 , the main controller  301  controls driving of a suction fan motor  308  via the suction-fan driving unit  307  to rotate the suction fan  27  to adhere the print medium  2  onto the protection belt  21 . 
     When the conveyance motor  306  is rotated and a drive of the conveyance roller  22  is transmitted to the output rollers  32 , the output rollers  32  are rotated. 
     The main controller  301  drives a cutter motor  310  to move the cutter  31   a  of the cutter unit  31  in the main scanning direction via the cutter driving unit  309  to cut, to a desired length, the print medium  2  having the image formed by the recording heads  11  to create a print medium piece (label piece). 
     A control panel (control unit)  320  is connected to the main controller  301 . Detection signals (sensing signals) of the sensor  34  are input to the main controller  301 . 
     Next, control of printing operation by the controller according to at least one exemplary embodiment of this disclosure is described with reference to  FIG. 7 . 
       FIG. 7  is a flowchart of a procedure of control of printing operation by the controller according to at least one exemplary embodiment of this disclosure. 
     On receiving a print instruction at S 101 , at S 102  the main controller  301  drives the conveyance motor  306  via the conveyance-roller driving unit  305  to rotate the conveyance roller  22  to convey the print medium  2  to an image formation position. As described above, in the steps, the output rollers  32  are rotated while the conveyance roller  22  is rotated. 
     At  103 , image forming operation including driving of the recording heads  11 , moving of the carriage  12 , and intermittent conveyance of the print medium  2  is performed to form a desired image on the print medium  2 . 
     At S 104 , the main controller  301  drives (or continues driving) the conveyance motor  306  to convey a cut position of the print medium  2  having the image formed to a cutting position of the cutter unit  31  and at S 105  stops the conveyance motor  306 . As a result, the output rollers  32  are stopped. 
     At S 106 , the main controller  301  moves the cutter  31   a  of the cutter unit  31  in the main scanning direction and cuts the print medium  2  to form a label piece  200 . 
     At this time, the label piece  200  is sandwiched and held by the output rollers  32  and the spur rollers  33  in a state in which the label piece  200  is drawable out from the output port (extraction port)  105 . 
     At S 107 , the main controller  301  determines whether or not the label piece  200  is detected by the sensor  34  (i.e., the label piece  200  is present or not). 
     When the sensor  34  does not detect the label piece  200  (NO at S 107 ), at S 108  the main controller  301  determines whether or not printing operation is finished. When printing operation is not finished (NO at S 108 ), the process returns to S 103  and restarts image forming operation. When printing operation is finished (YES at S 108 ), the process ends. 
     In other words, after the print medium  2  is cut into a print medium piece, i.e., the label piece  200 , the label piece  200  is held in a state in which the label piece  200  is drawable out from the output port  105  of the label piece  200 . After the label piece  200  is drawn out from the output port  105  by an operator, the main controller  301  starts the next image forming operation. 
     As described above, holding the label piece  200  in such a drawable state prevents the adhesive face  2   b  of the label piece  200  from adhering to other members and enhances ease of handling of label piece after cutting without reducing the adhesive force. 
     The surfaces of the output rollers  32  are processed to facilitate separation from the adhesive face  2   b  of the label piece  200 , thus preventing adherence of the label piece  200  to the output rollers  32  and facilitating drawing of the label piece  200 . In addition, the processed surfaces of the output rollers  32  prevents the output rollers  32  from taking a portion of adhesive material out of the adhesive face  2   b  of the label piece  200 , thus preventing a reduction in the adhesive force of the label piece  200 . 
     Here, first and second comparative examples are described with reference to FIGS.  8 A and  8 B. 
       FIG. 8A  is a schematic view of an output unit according to the first comparative example.  FIG. 8B  is a schematic view of an output unit according to the second comparative example. 
     For the first comparative example, a cutter unit  31  is disposed downstream from output rollers  32  in a feed direction of a print medium  2 . When an operator draws the print medium  2  output by the output rollers  32  as a label piece  200 , the operator handles the cutter unit  31  to cut the print medium  2 . 
     For such a configuration, the label piece  200  having been cut from the print medium  2  is not held, drops immediately after cutting, and adheres to other components, thus resulting in a reduced adhesive force or other failure. 
     For the second comparative example, as with the first comparative example, a cutter unit  31  is disposed downward from output rollers  32 , and a reel roll  500  is disposed downward from the cutter unit  31  to reel a label piece  200 . 
     For such a configuration, since the label piece  200  having been cut by the cutter unit  31  is reeled and stocked by the reel roll  500 , the label piece  200  may also be curled even after separation from the reel roll  500 . In addition, since an adhesive face of the label piece  200  is once adhered onto the reel roll  500 , the adhesive force may be reduced. 
     By contrast, for the above-described configuration, as described above, the label piece  200  is held at the output port in a state in which the label piece  200  is drawable from the output port, thus preventing dropping of the label piece  200  and a failure due to reeling of the label piece  200  to the reel roll  500 . 
     For the above-described exemplary embodiment, the next image forming operation is started after the label piece  200  is drawn out from the output port  105 . In some embodiments, when the distance from an image forming unit  102  to a cutting position of a cutter unit  31  is longer than a length of a label piece  200 , the next image formation is performed and a conveyance unit stands by. After the label piece  200  is drawn out, the conveyance unit conveys a print medium  2  to the cutting position. 
     In such a case, a driving system of a conveyance roller  22  is separately provided from a driving system of output rollers  32  so that the conveyance roller  22  can be driven independent of the output rollers  32 . 
     In other words, after a detector (e.g., a sensor  34 ) detects that a label piece  200  held by a holding unit (e.g., output rollers  32  and spur rollers  33 ) is drawn out, a main controller  301  controls the conveyance unit  103  to convey a print medium  2  to a cutting position of the cutter unit  31 . When the distance from an end position of image formation to the cutting portion is longer than a length of the label piece  200 , image formation is performed in advance. By contrast, when the distance is shorter than the length of the label piece  200 , image formation is started after the label pieces  200  is drawn out. 
     Next, a second exemplary embodiment of this disclosure is described with reference to  FIG. 9 . 
       FIG. 9  is a side view of an output unit of an image forming apparatus according to the second exemplary embodiment of this disclosure. 
     In this exemplary embodiment, multiple rotors forming an output unit (in  FIG. 9 , multiple sets of output rollers  32   a  to  32   c ) are disposed downward from a cutter unit  31  in a feed direction of a print medium  2 . Multiple sets of spur rollers  33   a  to  33   c  and the sets of output rollers  32   a  to  32   c  are disposed at opposite sides across a label piece  200  cut from the recording medium  2 . A sensor  34  is disposed to detect the label piece  200  at a position corresponding to the output rollers  32   c , which are located at a most downstream side of the sets of output rollers  32   a  to  32   c  in the feed direction of the print medium  2 . Driving force of the conveyance roller  22  is transmitted to the sets of output rollers  32   a  to  32   c  to rotate the sets of output rollers  32   a  to  32   c . In other words, in this disclosure, rollers rotated by receiving a rotation driving force are referred to as “output rollers”. 
     Such a configuration allows holding of the label piece  200  in a drawable state even when the label piece  200  is relatively long. 
     When the label piece  200  is relatively short, the sets of output rollers  32   a  to  32   c  are driven independent of the conveyance roller  22  to convey the label piece  200  to a position at which the output rollers  32   c  and the spur rollers  33   c  hold the label piece  200 . Such a configuration allows the label piece  200  to be held in a drawable state even when the label piece  200  is relatively short. 
     In some embodiments, when the label piece  200  is relatively short, label pieces  200  having been cut by a cutter unit  31  are configured to be held at positions downstream from the cutter unit  31  in a feed direction of the label pieces  200 . 
     For example, in the configuration of  FIG. 9 , a first label piece is held between the output rollers  32   c  and the spur rollers  33   c , a second label piece is held between the output rollers  32   b  and the spur rollers  33   b , and a third label piece is held between the output rollers  32   a  and the spur rollers  33   a . After the sensor  34  detects that the first label piece has been drawn out from between the output rollers  32   c  and the spur rollers  33   c , the second label piece and the third label piece are fed in turn. Then, a fourth label piece is formed by driving the cutter unit  31  and is held between the output rollers  32   a  and the spur rollers  33   a . 
     Such a configuration allows effective printing and delivery of short label pieces even in a structure in which the plurality of sets of output rollers  2   a  to  32   c  is provided to deal with a long label piece. 
     Next, a third exemplary embodiment of this disclosure is described with reference to  FIG. 10 . 
       FIG. 10  is a side view of an output unit of an image forming apparatus according to the third exemplary embodiment of this disclosure. 
     In this exemplary embodiment, the output unit includes adjusting means (in this exemplary embodiment, adjuster  36 ) to adjust a height of a roller holder  35  holding spur rollers  33 . 
     Such a configuration allows adjustment of a holding force for holding a label piece  200  by adjusting the height of the spur rollers  33  with the adjuster  36 . 
     Until a print medium  2  is conveyed to the output rollers  32 , the spur rollers  33  are retracted from the output rollers  32 . When the print medium  2  reaches the output rollers  32 , the spur rollers  33  are moved down to hold the print medium  2 . With the print medium  2  held between the output rollers  32  and the spur rollers  33 , the cutter unit  31  cuts the print medium  2  to form a label piece  200 . 
     In other words, because of the tackiness (adhesion) of an adhesive face  2   b  of the print medium  2 , the print medium  2  may not enter between rotors, such as rollers and spur rollers, thus causing a conveyance jam. Hence, on the entry of the print medium  2 , the spur rollers  33  are moved away from the output rollers  32 . After the spur rollers  33  are pressed against the output rollers  32  via the print medium  2 , the print medium  2  is cut by the cutter unit  3   l  to form a print medium piece (label piece)  200 . Then, the label piece  200  having been cut from the print medium  2  is held between the spur rollers  33  and the output rollers  32 , thus preventing occurrence of a conveyance jam. 
     Next, a fourth exemplary embodiment of this disclosure is described with reference to  FIG. 11 . 
       FIG. 11  is a side view of an output unit of an image forming apparatus according to the fourth exemplary embodiment of this disclosure. 
     A configuration of this exemplary embodiment differs from the configuration of the above-described first exemplary embodiment in that a rotary support roller  37  serving as a support member to support a label piece  200  is disposed at a position downward from and lower than the output rollers  32 . 
     A surface of the support roller  37  is non-adhesive processed so that the adhesive face  2   b  of the label piece  200  does not adhere to the surface of the support roller  37 . Alternatively, in some embodiments, the surface of the support roller  37  is made of a material that prevents the adhesive face  2   b  of the label piece  200  from adhering to the surface of the support roller  37 . 
     For this exemplary embodiment, the support roller  37  is freely rotatable and rotated by movement of the label piece  200  without receiving transmission of the rotation driving force. 
     Such a configuration allows stable holding and standby of the label piece  200  even when the distance from the output rollers  32  to the output port  105  is relatively long, in other words, the label piece  200  is relatively long. 
     For example, the configuration of  FIG. 9  employing, e.g., the spur rollers  33  and the roller holder  35  may increase the cost of components. In addition, since multiple output rollers  32  are arranged in parallel across a distance compatible with the length of the label piece  200 , the image forming apparatus is likely to have a relatively large size. 
     However, if the lengths of label pieces  200  to be used are approximately constant, the arrangement of the support roller  37  at a position diagonally downward from the output rollers  32  as illustrated in  FIG. 11  allows a reduction in the cost of components. In addition, supporting the label piece  200  diagonally downward allows a reduced apparatus size as compared to supporting the label piece  200  horizontally. 
     Next, a fifth exemplary embodiment of this disclosure is described with reference to  FIG. 12 . 
       FIG. 12  is a side view of an output unit of an image forming apparatus according to the fifth exemplary embodiment of this disclosure. 
     A configuration of this exemplary embodiment differs from the configuration of the above-described first exemplary embodiment in that multiple sets of rotary support rollers (in this exemplary embodiment, four sets of rotary support rollers  37   a  to  37   d ) serving as support members to support a label piece  200  are disposed at positions downward from and lower than the output roller  32 . 
     The sets of support rollers  37   a  to  37   d  are arranged in turn in a direction diagonally downward along a feed direction of the label piece  200 . 
     Such a configuration can give effects equivalent to those of the above-described fourth exemplary embodiment and minimize the conveyance load in outputting the label piece  200 . 
     Next, a sixth exemplary embodiment of this disclosure is described with reference to  FIG. 13 . 
       FIG. 13  is a side view of an image forming apparatus according to the sixth exemplary embodiment of this disclosure. 
     For this exemplary embodiment, a configuration of  FIG. 13  is employed instead of the configuration of  FIG. 3A  in the first exemplary embodiment, and an image forming unit  102  forms an image on an adhesive face  2   a  of a print medium  2 . 
     In such a case, the print medium  2  is sucked and adhered onto the conveyance belt  51  having suction holes  51 , and with the print medium  2  adhered on the conveyance belt  51 , the print medium  2  is conveyed. As with the configuration of  FIG. 4 , even the print medium  2  thus conveyed is held between output rollers  32  and spur rollers  33  for standby. In such a case, since an adhesive face  2   b  of the print medium  2  is faced up, the output rollers  32  and the spur rollers  33  are disposed at positions opposite to the positions of the output rollers  32  and the spur rollers  33  in  FIG. 4 . 
     As described above, conveying of the print medium  2  having an adhesive face with the conveyance belt  51  allows stable conveyance of the print medium  2 . 
     Numerous additional modifications and variations are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the present disclosure may be practiced otherwise than as specifically described herein. With some embodiments having thus been described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the scope of the present disclosure and appended claims, and all such modifications are intended to be included within the scope of the present disclosure and appended claims.