Abstract:
A recording device includes a platen, a recording head, a carriage and a cleaning unit. The platen supports a roll paper. The recording head ejects liquid onto the roll paper on the platen. The carriage supports the recording head. The cleaning unit is installed apart from the platen in a transport direction of the roller paper. The carriage transports the recording head in a direction parallel to the transport direction of the roll paper supported on the platen when the cleaning unit cleaning the recording head.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a continuation application of U.S. patent application Ser. No. 14/021,308, which is a continuation application of U.S. patent application Ser. No. 13/177,731. This application claims priority to Japanese Patent Application No. 2010-162022 filed on Jul. 16, 2010. The entire disclosures of U.S. patent application Ser. Nos. 14/021,308 and 13/177,731, and Japanese Patent Application No. 2010-162022 are hereby incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present invention relates to a recording device for recording an image on roll paper and a method for controlling a recording device. 
         [0004]    2. Related Art 
         [0005]    There is already a known recording device which comprises a conveying part for conveying roll paper, a support part for supporting the roll paper, a recording part for discharging a liquid and recording an image on the roll paper which is being supported by the support part, a heating part for drying the liquid discharged on the roll paper by heating the support part, and a cleaning part for cleaning the recording part (see, Japanese Laid-Open Patent Application Publication No. 2005-246908) 
       SUMMARY 
       [0006]    However, a problem in conventional practice is that when the roll paper is conveyed after cleaning of the recording part is performed by the cleaning part, there are cases in which wrinkles occur in the roll paper. 
         [0007]    The present invention was devised in view of such conventional problems, and an object thereof is to minimize the occurrence of wrinkles in the roll paper. 
         [0008]    A recording device according to one aspect of the present invention includes a platen, a recording head, a carriage and a cleaning unit. The platen supports a roll paper. The recording head ejects liquid onto the roll paper on the platen. The carriage supports the recording head. The cleaning unit is installed apart from the platen in a transport direction of the roller paper. The carriage transports the recording head in a direction parallel to the transport direction of the roll paper supported on the platen when the cleaning unit cleaning the recording head. 
         [0009]    Other characteristics of the present invention are made clear by the content of the present specification and the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    Referring now to the attached drawings which form a part of this original disclosure: 
           [0011]      FIG. 1  is a schematic front view of a printer  11 ; 
           [0012]      FIG. 2  is a cross-sectional view of a platen  28 ; 
           [0013]      FIG. 3  is a block diagram of the control configuration of the printer  11 ; 
           [0014]      FIG. 4  is a flowchart describing the action of the printer  11 ; and 
           [0015]      FIG. 5  is a top view showing the positional relationship of roll paper  12  to a first conveying roller pair  25  and to the platen  28 . 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0016]    The following matters at least will be made clear from the content of the present specification and the accompanying drawings. 
         [0017]    A recording device according to the embodiment of the present invention includes a conveying part, a support part, a recording part, a heating part, a cleaning part and a controller. The conveying part is configured and arranged to convey a roll paper. The support part is configured and arranged to support the roll paper. The recording part is configured and arranged to eject liquid on the roll paper to record an image on the roll paper supported by the support part. The heating part is configured and arranged to heat the support part to dry the liquid ejected onto the roll paper. The cleaning part is configured and arranged to clean the recording part. The controller is configured to control the conveying part to convey the roll paper at a first speed when the recording part performs a recording action for recording the image, and to control the conveying part to convey the roll paper at a second speed, which is slower than the first speed, after the cleaning part performs a cleaning action for cleaning the recording part. 
         [0018]    According to this recording device, the occurrence of wrinkles in the roll paper can be minimized. 
         [0019]    In the recording device, the conveying part may include a plurality of rollers over which the roll paper wraps, the rollers including a proximal roller at a position nearest to the support part among the rollers disposed upstream of the support part in the conveying direction. The controller may be configured to, after the cleaning part performs the cleaning action for cleaning the recording part, control the conveying part to convey the roll paper at the second speed until a region of the roll paper wrapped over the proximal roller during the cleaning action is conveyed past an upstream end of the support part with respect to the conveying direction, and control the conveying part to convey the roll paper at a faster speed than the second speed after the region has been conveyed past the upstream end of the support part. 
         [0020]    According to this recording device, the roll paper can be conveyed in a short amount of time while the occurrence of wrinkles in the roll paper is minimized. 
         [0021]    The recording device may further include a suction part configured and arranged to hold the roll paper to the support part by suction. The controller may be configured to control the suction part to use a first suction force to hold the roll paper to the support part by suction when the recording part performs a recording action for recording the image, and to control the suction part to use a second suction force, which is weaker than the first suction force, to hold the roll paper to the support part by suction when the cleaning part performs a cleaning action for cleaning the recording part. 
         [0022]    According to this recording device, the occurrence of wrinkles in the roll paper can be minimized more reliably. 
         [0023]    The recording device may further include a fan configured and arranged to blow air toward the roll paper to dry the liquid discharged onto the roll paper. The controller may be configured to actuate the fan when the recording part performs the recording action for recording the image and when the cleaning part performs the cleaning action for cleaning the recording part. 
         [0024]    According to this recording device, the occurrence of wrinkles in the roll paper can be minimized more reliably. 
         [0025]    A method for controlling a recording device according to the embodiment includes: when a recording part performs a recording action for discharging a liquid and recording an image on a roll paper supported by a heated support part, controlling a conveying part to convey, at a first speed, the roll paper supported by the support part; and after a cleaning part performs a cleaning action for cleaning the recording part, controlling the conveying part to convey, at a second speed that is slower than the first speed, the roll paper supported by the support part. 
         [0026]    According to this method for controlling a recording device, the occurrence of wrinkles in the roll paper can be minimized. 
       First Embodiment 
       [0027]    The first embodiment in which the recording device of the present invention is specified as an inkjet printer (hereinbelow referred to as a “printer”) is described hereinbelow based on the drawings. In the following description, when an “up-down direction” and a “left-right direction” are mentioned, they are referencing the directions shown by the arrows in  FIG. 1 . When a “forward-backward direction” is mentioned, it indicates the direction orthogonal to the paper surface of  FIG. 1 . 
       Configuration of Printer 
       [0028]      FIG. 1  is a schematic front view of the printer  11  of the first embodiment. 
         [0029]    The printer  11  as a recording device of the first embodiment comprises a main body  14  for sequentially performing printing in sequence on roll paper  12  unreeled from an unreeling part  13  for unreeling the roll paper  12 , and a winding part  15  for winding up the roll paper  12  that has undergone the recording action in the main body  14 , as shown in  FIG. 1 . The main body  14  has a main body case  16  shaped as a right-angled parallelepiped. The unreeling part  13  is set up to the left of the main body case  16 , which is the upstream side in the conveying direction of the roll paper  12 . The winding part  15  is set up to the right of the main body case  16 , which is the downstream side in the conveying direction of the roll paper  12 . 
         [0030]    The unreeling part  13  has a support plate  17  extending to the left from the bottom end of the left surface of the main body case  16 . On the left end of the support plate  17 , a winding shaft  18  extending forward (toward the viewer in the direction orthogonal to the paper surface in  FIG. 1 ) is supported to be capable of rotating relative to the support plate  17 . The roll paper  12 , which has been wound into a roll shape in advance, is supported on the winding shaft  18  to be capable of rotating integrally with the winding shaft  18 . 
         [0031]    The unreeling part  13  has a flat plate-shaped unreeling stand  19  extending horizontally to the left from the center of the left surface of the main body case  16 . Rotatably provided to the distal end of the unreeling stand  19  is a relay roller  20  for engaging the roll paper unreeled from the winding shaft  18  and leading the roll paper to the top surface of the unreeling stand  19 . The roll paper  12  is then conveyed to the right (toward the main body  14 ) along the top surface of the unreeling stand  19 . 
         [0032]    In a position slightly higher than the vertical center inside the main body case  16  of the main body  14 , a flat plate-shaped base stand  21  is provided for dividing the main body case  16  interior into a top and bottom. The area above the base stand  21  in the main body case  16  is a printing chamber  22  for performing printing on the roll paper  12 . 
         [0033]    In the left wall of the main body case  16 , an inlet port (not shown) is provided for conveying the roll paper  12  into the main body case  16  from the top surface of the unreeling stand  19 . The main body  14  then has a relay roller  23  rotatably provided so as to face the inlet port at a nearby position. 
         [0034]    A relay roller  24  is rotatably provided to the right and below the relay roller  23  inside the main body case  16 . After the roll paper  12  has been conveyed into the main body case  16 , the roll paper wraps over the relay roller  24  from the left and above and is conveyed so as to face a position approaching the left end of the printing chamber  22 . 
         [0035]    In a position near the left end of the printing chamber  22 , a first conveying roller pair  25  (equivalent to the proximal roller) is provided for sandwiching and applying conveying force to the roll paper  12 . The first conveying roller pair  25  is configured from a first drive roller  25   a  connected to a first conveying motor (see  FIG. 3 )  26  so as enable the transmission of motive power, and a first driven roller  25   b  disposed so as to face the first drive roller  25   a  from the other side of the roll paper  12 . As the first drive roller  25   a  is rotatably driven, the roll paper  12  which wraps over the first drive roller  25   a  from the left and below is conveyed horizontally to the right. A platen  28  (one example of a support part) is provided in an area to the right of the first conveying roller pair  25  inside the printing chamber  22 . Specifically, the first conveying roller pair  25  is provided to a position near the upstream end of the platen  28 . 
         [0036]    The platen  28  has a support stand  28   a  provided in a state of being supported on the base stand  21 , the support stand  28   a  having a bottomed substantial box shape open in the top surface as shown in  FIG. 2 . On top of the support stand  28   a,  a rectangular plate-shaped carrying plate  28   b  is provided so as to bring a support surface PL which is the top surface thereof in contact with the roll paper  12  so as to close off the opening in the top of the support stand  28   a.    
         [0037]    Formed in the carrying plate  28   b  are numerous (only five are shown in  FIG. 1 ) through-holes A which pass vertically through the carrying plate  28   b  (in the thickness direction of the carrying plate  28   b ). An exhaust port B is formed in the left wall of the support stand  28   a,  and a suction fan  29  as suction means is connected via the exhaust port B. When the suction fan  29  is rotatably driven along with the rotatable driving of a suction fan motor (see  FIG. 3 )  30 , the air in the space enclosed between the support stand  28   a  and the carrying plate  28   b  is expelled out via the suction fan  29 . Specifically, the space enclosed between the support stand  28   a  and the carrying plate  28   b  constitutes a negative-pressure chamber  31  in which negative pressure is created based on the driving of the suction fan  29 . In the first embodiment, a suction unit (equivalent to the “suction part”) is configured from the suction fan  29 , the suction fan motor  30 , the negative-pressure chamber  31 , the through-holes A, and other components. 
         [0038]    When negative pressure is created in the negative-pressure chamber  31  along with the driving of the suction fan  29 , the same negative pressure takes effect in the through-holes A of the carrying plate  28   b  communicated with the negative-pressure chamber  31 . Therefore, the through-holes A of the carrying plate  28   b  function as suction holes for applying suction force to the roll paper  12  being conveyed over the support surface PL of the platen  28 . The negative-pressure chamber  31  is also provided with a pressure detection sensor  32  for detecting pressure changes in the negative-pressure chamber  31  that accompany the rotatable driving of the suction fan  29 . 
         [0039]    In an area to the right of the platen  28  inside the printing chamber  22  as shown in  FIG. 1 , a second conveying roller pair  33  is provided for sandwiching and applying conveying force to the roll paper  12 . Specifically, the second conveying roller pair  33  is provided to a position near the downstream end of the platen  28 . The second conveying roller pair  33  is configured from a second drive roller  33   a  connected to a second conveying motor  34  (see  FIG. 3 ) so as to enable the transmission of motive power, and a second driven roller  33   b  disposed so as to face the second drive roller  33   a  from the other side of the roll paper  12 . 
         [0040]    The roll paper  12  conveyed horizontally to the right from the first conveying roller pair  25  over the support surface PL of the platen  28  wraps over the second drive roller  33   a  from the left and above. The conveying direction of the roll paper  12  is then shifted from horizontally rightward to vertically downward. After the conveying direction of the roll paper  12  has been shifted to vertically downward by the second drive roller  33   a,  the roll paper  12  is conveyed vertically downward through a through-hole (not shown) provided in the base stand  21 . The top surface of the second drive roller  33   a  is flush with both the top surface of the first drive roller  25   a  and the support surface PL of the platen  28 . The second driven roller  33   b  is also configured so as to come in contact with the printing surface of the roll paper  12  only in the end edges in the width direction (the forward-backward direction). In the first embodiment, the conveying unit (equivalent to the “conveying part”) is configured from the unreeling part  13 , the winding part  15 , the winding shaft  18 , the relay roller  23 , the relay roller  24 , the first conveying roller pair  25 , the second conveying roller pair  33 , and other components. 
         [0041]    On the front and back sides of the platen  28  inside the printing chamber  22 , guide rails  35  (shown by a double-dotted line in  FIG. 1 ) extending in the left-right direction are provided so as to form a pair. The top surfaces of the guide rails  35  are higher than the support surface PL of the platen  28 . A rectangular plate-shaped carriage  35   a  is supported on the top surfaces of the guide rails  35  so as to be capable of moving back and forth in the left-right direction along the guide rails  35 . 
         [0042]    A recording head  36  (equivalent to the “recording part”) is supported on the bottom surface of the carriage  35   a.  On the bottom surface of the recording head  36 , numerous ink discharge nozzles (not shown) are arrayed in the forward-backward direction. A valve unit  37  for temporarily retaining ink is provided to the top wall of the main body case  16  inside the printing chamber  22 . The valve unit  37  is connected to the recording head  36  via an ink supply tube (not shown). The recording head  36  performs printing by ejecting ink supplied from the valve unit  37  from the ink discharge nozzles onto the surface of the roll paper  12  which has been conveyed to and stopped on the platen  28 . 
         [0043]    Therefore, the area midway through the conveying route of the roll paper  12  and running from the left end to the right end of the platen  28  is a printing area R where printing is performed on the roll paper  12  by the ejecting of ink from the ink discharge nozzles. The roll paper  12  is intermittently conveyed in area units corresponding to the printing area R along the conveying route. 
         [0044]    A heater unit  61  (equivalent to the “heating part) for heating the platen  28  is installed below the platen  28 . Heat is then transferred to the roll paper  12  via the platen  28  heated by the heater unit  61 , thereby promoting drying of the ink deposited on the roll paper  12 . The platen  28  is provided with a temperature detection sensor  62  for detecting the temperature of the platen  28 . Based on the temperature detected by the temperature detection sensor  62 , a controller  44  (described hereinafter) controls the amount of heating by the heater unit  61  so that the platen  28  reaches a predetermined temperature (45° C., for example). 
         [0045]    In the upper portion of the main body case  16 , an air-blowing fan  63  is provided which is rotatably driven along with the rotatable driving of an air-blowing fan motor  64  (see  FIG. 3 ). The air-blowing fan  63  takes in air from outside the printer  11  and blows the air toward the roll paper  12  supported on the platen  28 , thereby promoting drying of the ink deposited on the roll paper  12 . 
         [0046]    The roll paper  12  wrapped over the second drive roller  33   a  and conveyed vertically downward wraps over a reversal roller  38  from the left and above, the reversal roller  38  being rotatably disposed in a position vertically below the second drive roller  33   a  within the main body case  16 , and the roll paper  12  is conveyed at a slightly upward incline to the right. The roll paper  12  conveyed from the reversal roller  38  then wraps over a relay roller  39  from the left and below, the relay roller  39  being rotatably provided to the right of the reversal roller  38  within the main body case  16 , and the roll paper  12  is conveyed upward within the main body case  16  so as to run along the right wall of the main body case  16 . After being subjected to printing in the printing area R, the roll paper  12  is naturally dried by the process of being conveyed through the main body case  16 . 
         [0047]    In a position near the base stand  21  in the right wall of the main body case  16 , an outlet port (not shown) is provided for conveying the roll paper  12  out to the winding part  15 . A feed-out roller  40  is rotatably provided in the main body case  16  in a position facing the position near the outlet port. The feed-out roller  40  is designed to feed the roll paper  12  out to the winding part  15  via the outlet port. 
         [0048]    The winding part  15  has a right-angled parallelepiped winding frame  41 . A relay roller  42  is rotatably provided to the top end of the winding frame  41 . The roll paper  12  fed out from the inlet port is wrapped over the relay roller  42  from the left and above and conveyed to the right and downward. 
         [0049]    To the right and obliquely below the relay roller  42  within the winding frame  41 , a winding drive shaft  43  extending forward is supported to be capable of being rotatably driven relative to the winding frame  41 . The roll paper  12  conveyed to the right and obliquely downward from the relay roller  42  is wrapped over the winding drive shaft  43 . The roll paper  12  is sequentially wound up along with the rotatable driving of the winding drive shaft  43 . 
         [0050]    The main body  14  has a cleaning unit  66  (equivalent to the “cleaning part”) in the upper left of interior of the main body  14 . The cleaning unit  66  is a mechanism for cleaning the recording head  36  either at the start of the recording action or after the elapse of a specified time duration following the previous cleaning or some other predetermined timing, so that the recording head  36  is capable of appropriately discharging ink. The cleaning unit  66  has a suction pump (not shown) as a negative-pressure source for drawing in the ink, a wiper (not shown) for scraping and cleaning the discharge port surface of the recording head  36 , and other components. Cleaning the recording head  36  involves alleviating clogging in the nozzles, removing ink or waste deposited on the nozzle surface, or other forms of cleaning through flushing by the suction pump or wiping by the wiper. When the recording head  36  is cleaned, the carriage  35   a  conveys the recording head  36  to the cleaning unit  66 . One cleaning action of the cleaning unit  66  takes approximately three to ten minutes. 
       Control of Printer 
       [0051]    Next, the control in the printer  11  of the present embodiment will be described.  FIG. 3  is a block diagram of the control configuration of the printer of the first embodiment. 
         [0052]    The printer  11  is provided with a controller  44  for controlling the drive state of the entire device, as shown in  FIG. 3 . The controller  44  has a CPU  45  as a central processing unit, ROM  46 , and RAM  47 . The ROM  46  stores processing routine programs and the like pertaining to the recording action and the cleaning action shown in the flowchart in  FIG. 4 . The RAM  47  temporarily stores computation results of the CPU  45  and temporarily stores print data and the like inputted from an external input device  48 . 
         [0053]    The controller  44  is connected to the recording head  36  via a head driver  49 . The controller  44  reads from the RAM  47  the print data inputted from the external input device  48 , and sends the read print data to the head driver  49 . The head driver  49  discharges ink droplets from the ink discharge nozzles of the recording head  36  on the basis of the print data received from the controller  44 . 
         [0054]    The controller  44  drivably controls the first conveying motor  26  via a first conveying motor driver  50 . As the first conveying motor  26  is rotatably driven, the first drive roller  25   a  conveys the roll paper  12  downstream in the conveying direction until the conveyed amount reaches a predetermined amount based on the rotated amount of the first conveying motor  26 . 
         [0055]    Connected to the controller  44  is a rotation amount detection sensor  51  for detecting the rotation amount of the first conveying motor  26 . The controller  44  is designed to perform feedback control on the rotation amount of the first conveying motor  26  via the first conveying motor driver  50 , on the basis of the detection result of the rotation amount of the first conveying motor  26  received from the rotation amount detection sensor  51 . 
         [0056]    The controller  44  drivably controls the second conveying motor  34  via a second conveying motor driver  52 . As the second conveying motor  34  is rotatably driven, the second drive roller  33   a  subjects the roll paper  12  to a predetermined amount of tension based on the torque of the second conveying motor  34 . 
         [0057]    A torque detection sensor  53  for detecting the torque of the second conveying motor  34  is connected to the controller  44 . The controller  44  is designed to perform feedback control on the torque of the second conveying motor  34  via the second conveying motor driver  52 , on the basis of the detection result of the torque of the second conveying motor  34  received from the torque detection sensor  53 . 
         [0058]    The controller  44  also controls the heating amount of the heater unit  61  so that the platen  28  reaches a predetermined temperature (45° C., for example), on the basis of the temperature detected by the temperature detection sensor  62 . Therefore, drying of the ink deposited on the roll paper  12  is promoted by the platen  28 , which is kept at the predetermined temperature. 
         [0059]    The controller  44  also drivably controls the suction fan motor  30  via a suction fan motor driver  54 . As the suction fan motor  30  is rotatably driven, the suction fan  29  reduces the pressure in the negative-pressure chamber  31  by a predetermined suction force based on the rotating speed of the suction fan motor  30 . As a result, the negative pressure in the negative-pressure chamber  31  acts on the roll paper  12  via the through-holes A of the carrying plate  28   b,  as a suction force against the support surface PL of the platen  28 . 
         [0060]    The controller  44  drivably controls the air-blowing fan motor  64  via an air-blowing fan motor driver  65 . The air-blowing fan  63  then rotates along with the rotatable driving of the air-blowing fan motor  64 , air is taken in from outside the printer  11 , and the air is blown toward the roll paper  12  supported on the platen  28 . As a result, drying of the ink deposited on the roll paper  12  is promoted. 
       Operation of Printer 
       [0061]    Next, the action of the printer  11  configured in the above manner will be described.  FIG. 4  is a flowchart describing the action of the printer  11 . The controller  44  controls the recording action and the cleaning action in the printer  11  by reading and executing from the ROM  46  the process routine programs pertaining to the actions of the printer  11 . In the present embodiment, in a first stage in which the controller  44  executes the routine programs pertaining to the recording action and the cleaning action, the print data used by the recording head  36  on the roll paper  12  is inputted in advance from the external input device  48  to the RAM  47 . 
         [0062]    When a print command is received from the external input device  48 , the controller  44  executes the recording action as shown in  FIG. 4  (S 402 ). When the recording action is executed, the controller  44  drivably controls the suction fan motor  30  and causes the suction fan  29  to expel the air in the negative-pressure chamber  31  out to the exterior so that the pressure in the negative-pressure chamber  31  detected by the pressure detection sensor  32  reaches a first pressure PI (840 Pa, for example). The negative pressure in the negative-pressure chamber  31  acts so as to hold the roll paper  12  to the support surface PL of the platen  28  by suction with a suction-force F 1  (equivalent to the “first suction force”) via the through-holes A of the carrying plate  28   b.  When executing the recording action, the controller  44  controls the heating amount of the heater unit  61  so that the platen  28  reaches a predetermined temperature (45° C., for example) on the basis of the temperature detected by the temperature detection sensor  62 , and also drivably controls the air-blowing fan motor  64  so that the amount of air blown by the air-blowing fan  63  reaches a predetermined amount, thereby promoting drying of the ink deposited on the roll paper  12 . 
         [0063]    When executing the recording action, the controller  44  causes the recording head  36  to discharge ink (hereinbelow the “discharging process”) onto the portion of the roll paper  12  positioned above the support surface PL of the platen  28  (hereinbelow the “platen-top portion”). Specifically, the controller  44  causes an image to be recorded on this portion (the platen-top portion) by executing the discharge process. Next, the controller  44  causes the conveying unit to convey the roll paper  12  (hereinbelow the “conveying process”). Specifically, the controller  44  executes the conveying process, causing the portion of the roll paper  12  on which the image is recorded to be ejected off of the support surface PL of the platen  28 , and conveys the portion of the roll paper  12  where the next image will be recorded onto the support surface PL of the platen  28 . During this conveying process, the controller  44  controls the conveying unit so that the conveying speed at which the conveying unit conveys the roll paper reaches a first speed V (600 mm/s, for example). Thus, when the recording action is executed, the controller  44  repeatedly alternates between executing the discharge process and executing the conveying process. 
         [0064]    Next, when the recording action has been continuously executed for a predetermined time duration, the controller  44  halts the recording action and executes a switch for executing a cleaning action for cleaning the recording head  36  (S 404 ). Specifically, the controller  44  causes the carriage  35   a  to convey the recording head  36  to the cleaning unit  66 . When a switch is made from the recording action to the cleaning action, the controller  44  drivably controls the suction fan motor  30  and causes the suction fan  29  to expel the air in the negative-pressure chamber  31  out to the exterior so that the pressure in the negative-pressure chamber  31  detected by the pressure detection sensor  32  reaches a second pressure P 2  (P 2 &lt;P 1 ; 140 Pa, for example). Specifically, the controller  44  drivably controls the suction fan motor  30  so that the suction force for holding the roll paper  12  to the support surface PL of the platen  28  by suction changes from the suction force F 1  to the suction force F 2  (F 2 &lt;F 1 ; equivalent to the “second suction force”). When a switch is made from the recording action to the cleaning action, the roll paper  12  is not conveyed, and the portion of the roll paper  12  on which the image has been recorded is left on the support surface PL of the platen  28 . Even during switching, the controller  44  continues to control the heating amount of the heater unit  61  so that the platen  28  reaches a predetermined temperature (45° C., for example) on the basis of the temperature detected by the temperature detection sensor  62 , and also drivably controls the air-blowing fan motor  64  so that the amount of air blown by the air-blowing fan  63  reaches a predetermined amount, thereby promoting drying of the ink deposited on the roll paper  12 . 
         [0065]    Furthermore, the controller  44  causes the cleaning unit  66  to execute the action of cleaning the recording head  36  (S 406 ). When the cleaning action is executed, the controller  44  causes the cleaning unit  66  to execute the cleaning action by washing, wiping, or the like. At this time, the controller  44  drivably controls the suction fan motor  30  so that the roll paper  12  is held by suction to the support surface PL of the platen  28  with a suction force F 2 . One cleaning action of the cleaning unit  66  takes approximately three to ten minutes. During the cleaning action, the roll paper  12  is not conveyed, and the portion of the roll paper  12  on which the image has been recorded is left on the support surface PL of the platen  28 . Even during the cleaning action, the controller  44  continues to control the heating amount of the heater unit  61  so that the platen  28  reaches a predetermined temperature (45° C., for example) on the basis of the temperature detected by the temperature detection sensor  62 , and also rotates the air-blowing fan  63  by drivably controlling the air-blowing fan motor  64 , which promotes drying of the ink deposited on the roll paper  12 . 
         [0066]    After the cleaning action has ended, the controller  44  executes a switch from the cleaning action to the recording action (S 408 ). Specifically, the controller  44  causes the carriage  35   a  to convey the recording head  36  from the cleaning unit  66  to a position above the platen  28 . At this time, the controller  44  drivably controls the suction fan motor  30  and causes the suction fan  29  to expel the air in the negative-pressure chamber  31  out to the exterior so that the pressure in the negative-pressure chamber  31  detected by the pressure detection sensor  32  reaches the first pressure P 1 . The negative pressure in the negative-pressure chamber  31  acts via the through-holes A of the carrying plate  28   b  so as to hold the roll paper  12  to the support surface PL of the platen  28  by a suction force F 1 . The controller  44  then causes the conveying unit to execute the conveying process of conveying the roll paper  12 , the portion of the roll paper  12  on which the image is recorded is ejected off of the support surface PL of the platen  28 , and a portion of the roll paper  12  where a new image will be recorded is conveyed onto the support surface PL of the platen  28 . During this conveying process, the controller  44  controls the conveying unit so that the conveying speed whereby the conveying unit conveys the roll paper reaches a second speed V 2  (V 2 &lt;V 1 ; 50 mm/sec, for example). Even after the cleaning action has ended, the controller  44  continues to control the heating amount of the heater unit  61  so that the platen  28  reaches a predetermined temperature (45° C., for example) on the basis of the temperature detected by the temperature detection sensor  62 , and also to drivably control the air-blowing fan motor  64  so that the amount of air blown by the air-blowing fan  63  reaches a predetermined amount, thereby promoting drying of the ink deposited on the roll paper  12 . 
         [0067]    In this manner, the controller  44  again executes the recording action (S 402 ). 
       Effectiveness of Printer 
       [0068]    As described above, with the printer  11  (and the controller  44  thereof) according to the first embodiment, the occurrence of wrinkles in the roll paper  12  can be minimized by including the conveying unit for conveying the roll paper  12 , the platen  28  for supporting the roll paper  12 , the recording head  36  for discharging liquid and recording an image on the roll paper  12  being supported by the platen  28 , the heater unit  61  for drying the liquid discharged onto the roll paper  12  by heating the platen  28 , the cleaning unit  66  for cleaning the recording head  36 , and the controller  44  for causing the conveying unit to convey the roll paper  12  at a first speed V 1  when the recording head  36  is made to perform the recording action of recording an image and for causing the conveying unit to convey the roll paper  12  at a second speed V 2  which is slower than the first speed V 1  after the cleaning unit  66  is made to perform the cleaning action of cleaning the recording head  36 . 
         [0069]    Specifically, the heat of the heated platen  28  and the air blown by the air-blowing fan  63  promote drying of the ink deposited on the roll paper  12  and also promote drying of the portion of the roll paper  12  positioned on the platen  28  (the platen-top portion). Since the roll paper  12  is sequentially conveyed during the recording action, a specified portion of the roll paper  12  (the platen-top portion) is not subjected for a long period of time to the promotion of drying by the platen  28  and the air-blowing fan  63 , and the drying of the specified portion of the roll paper  12  (the platen-top portion) alone does not progress. However, during the cleaning action, since the roll paper  12  comes to a stop, the specified portion of the roll paper  12  (the platen-top portion) alone is retained on the platen  28  and subjected to the promotion of drying by the platen  28  and the air-blowing fan  63 , and drying of the specified portion of the roll paper  12  (the platen-top portion) progresses. When the state is such that drying of the specified portion of the roll paper  12  (the platen-top portion) is progressing and the portion of the roll paper  12  adjacent to this portion (the portion of the roll paper  12  positioned nearby upstream in the conveying direction as seen from the platen  28  during the cleaning action; hereinbelow the “upstream portion”) is not being dried very much, there is a large difference in the extent of drying between continuous adjacent portions of the roll paper  12 , and wrinkles are likely to occur. When the roll paper  12  is conveyed at the first speed V 1  while in this state of being prone to wrinkles and the upstream portion of the roll paper  12  moves onto the platen  28 , the upstream portion of the roll paper  12  is rubbed (brushed) by the upstream end of the platen  28 , whereby wrinkles sometimes occur in the upstream portion of the roll paper  12  (see  FIG. 5 ).  FIG. 5  is a top view showing the positional relationship of the roll paper  12  relative to the first conveying roller pair  25  and the platen  28 . When the roll paper  12  is conveyed after the cleaning action, as shown in this drawing, wrinkles W sometimes occur in the upstream portion of the roll paper  12 . 
         [0070]    However, with the printer  11  of the first embodiment, by causing the conveying unit to convey at a second speed V 2  which is slower than the first speed V 1 , i.e. by slowly conveying the portion of the roll paper  12  that is prone to wrinkles after the cleaning unit  66  is made to execute the cleaning action, the occurrence of wrinkles in the roll paper  12  can be minimized. In other words, the occurrence of wrinkles in the upstream portion of the roll paper  12  can be minimized by ensuring that the upstream portion of the roll paper  12  is not rubbed at high speeds (not brushed at high speeds) by the upstream end of the platen  28  during conveying after the cleaning action. 
         [0071]    With the printer  11  according to the first embodiment, the controller  44  causes the suction unit to hold the roll paper  12  to the wrinkle prevention plate  27  by a first suction force F 1  when the recording head  36  is made to perform the recording action of recording an image, and causes the suction unit to hold the roll paper  12  to the platen  28  by second suction force F 2  which is less than the first suction force F 1  when the cleaning unit  66  is made to perform the cleaning action of cleaning the recording head  36 , whereby the occurrence of wrinkles in the roll paper  12  anne further minimized. 
         [0072]    Specifically, to prevent the portion of the roll paper  12  positioned over the platen  28  (the platen-top portion) from coming in contact with the recording head  36  during the recording action, the roll paper  12  must be restrained on the platen  28  by a strong suction force (the first suction force F 1 ). On the other hand, there is no need to restrain the roll paper  12  on the platen  28  with a strong suction force because there is no risk of the platen-top portion of the roll paper  12  coming in contact with the recording head  36 . As described above, during the cleaning action, there is a state in which drying of the specified portion of the roll paper  12  (the platen-top portion) is promoted and wrinkles are likely to occur, but at this time, the occurrence of wrinkles can be minimized by lessening the suction force (suction is applied with the second suction force F 2  which is a lesser suction force) to lessen the force of restraining the platen-top portion of the roll paper  12  on the platen  28 , and allowing some freedom to the platen-top portion of the roll paper  12 . 
         [0073]    With the printer  11  according to the first embodiment, the controller  44  actuates the air-blowing fan  63  when the recording head  36  is made to perform the recording action and when the cleaning unit  66  is made to perform the cleaning action of cleaning the recording head  36 , whereby wrinkles in the roll paper  12  can be further minimized. 
         [0074]    Specifically, as described above, the platen-top portion of the roll paper  12  is dried by the heat of the platen  28  and the air blown by the air-blowing fan  63  during the cleaning action. When drying of the platen-top portion of the roll paper  12  is promoted and drying of the upstream portion of the roll paper  12  adjacent thereto is not promoted, there is a large difference in the extent of drying between the platen-top portion and the upstream portion, and wrinkles are likely to occur. With the printer  11  according to the first embodiment, drying of the upstream portion of the roll paper  12  can be promoted as well as of the platen-top portion of the roll paper  12  by actuating the air-blowing fan  63  not only during the recording action but also during the cleaning action, the difference in the extent of drying between the platen-top portion and upstream portion of the roll paper  12  can be prevented from being too large, and the occurrence of wrinkles in the roll paper  12  can thereby be minimized. 
       Other Embodiments 
       [0075]    The first embodiment pertains primarily to the recording device, but also includes the disclosure of the method for controlling a recording device and the like. The first embodiment is intended to make the present invention easier to understand and should not be interpreted as limiting the present invention. The present invention can be modified and improved without deviating from the scope of the invention, and such equivalents are of course included within the present invention. The embodiments described hereinbelow in particular are included in the present invention. 
         [0076]    In the first embodiment, after making the cleaning unit  66  perform the cleaning action of cleaning the recording head  36 , the controller  44  causes the conveying unit to convey the roll paper  12  at the second speed V 2  which is slower than the first speed V 1 , but another option is to cause the conveying unit to convey the roll paper  12  at the second speed V 2  until the region of the roll paper  12  that was wrapped over the first conveying roller pair  25  (hereinbelow the “roller region”) during the cleaning action is conveyed past the end of the platen  28  that is upstream in the conveying direction, and to cause the conveying unit to convey the roll paper  12  at a faster speed than the second speed V 2  after the roller region has been conveyed past the end of the platen  28  that is upstream in the conveying direction. 
         [0077]    Specifically, the portion of the roll paper  12  most prone to wrinkles is the portion of the roll paper  12  that is positioned between the first conveying roller pair  25  and the upstream end of the platen  28  during the cleaning action. After the cleaning action has ended, the occurrence of wrinkles in the roll paper  12  can be minimized by slowly conveying this wrinkle-prone portion. After the wrinkle-prone portion has passed over the upstream end of the platen  28 , the controller  44  can reduce the time needed to convey the roll paper  12  by causing the conveying unit to convey the roll paper  12  at a faster speed than the second speed V 2 . 
         [0078]    In the first embodiment, the configuration may be provided with an atmosphere opening valve for opening the interior of the negative-pressure chamber  31  to the atmosphere. In this case, it is possible to quickly reduce the rate of depressurization in the negative-pressure chamber  31  by opening the interior of the negative-pressure chamber  31  to the atmosphere by the atmosphere opening valve at the same time the suction force within the negative-pressure chamber  31  via the suction fan  29  is reduced. 
         [0079]    In the first embodiment, instead of providing a pressure detection sensor for detecting the pressure change in the negative-pressure chamber  31 , a flow rate detection sensor may be provided for detecting the flow rate of air vented from within the negative-pressure chamber  31  by the suction fan  29 . In this case, it can be determined that depressurization of the interior of the negative-pressure chamber  31  by the suction fan  29  is complete at the point in time when the controller  44  receives from the flow rate detection sensor a detection signal indicating that the flow rate of the air vented from within the negative-pressure chamber  31  by the suction fan  29  has fallen below a predetermined threshold. 
       General Interpretation of Terms 
       [0080]    In understanding the scope of the present invention, the term “comprising” and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and/or steps. The foregoing also applies to words having similar meanings such as the terms, “including”, “having” and their derivatives. Also, the terms “part,” “section,” “portion,” “member” or “element” when used in the singular can have the dual meaning of a single part or a plurality of parts. Finally, terms of degree such as “substantially”, “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. For example, these terms can be construed as including a deviation of at least ±5% of the modified term if this deviation would not negate the meaning of the word it modifies. 
         [0081]    While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. Furthermore, the foregoing descriptions of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.