Abstract:
A printing apparatus capable of forming an image on a recording medium is provided. The printing apparatus includes a recording head to eject ink onto the recording medium, a recording head controller to control movement of the recording head according to printing data, which represents the image to be formed on the recording medium, a carriage to carry the recording head in a main scanning direction relative to the recording medium, a plurality of platens, each of which has a holding surface to hold the recording medium thereon and is movable respectively in an auxiliary direction, which is perpendicular to the main scanning direction, and a plurality of drive mechanisms, each of which drives one of the platens in the auxiliary direction. The plurality of platens can be moved synchronously with one another.

Description:
CROSS REFERNCE TO RELATED APPLICATION  
       [0001]    This application claims priority from Japanese Patent Application NO. 2007-086750, filed on Mar. 29, 2007, the entire subject matter of which is incorporated herein by reference. 
       BACKGROUND  
       [0002]    1. Technical Field 
         [0003]    An aspect of the present invention relates to a printing apparatus, more specifically, a printing apparatus having a plurality of supporting means to support a recording medium thereon in the printing apparatus. 
         [0004]    2. Related Art 
         [0005]    Conventionally, a printing apparatus having an inkjet head from which inks are ejected onto a recording medium has been known. Such a printing apparatus is generally provided with a platen to hold the recording medium in position in the printing apparatus, and a size of a printable area on a surface of the recording medium depends on a size of the platen itself. Meanwhile, a printing apparatus having a plurality of platens has been suggested (e.g., United States Patent Application Publication No. US 2005/0179708 A1.) In the printing apparatus disclosed in the publication, the plurality of platens are provided to hold a plurality of pieces of recording medium in order to print images on the recording media in shorter lead time. According to the publication, each piece of the recording media is supported by one of the platens arranged on a same plane ( FIGS. 7B and 7C ) so that the images can be continuously printed on the recording media by the same inkjet head. 
         [0006]    In the above printing apparatus, although the lead time to print images on the plurality of pieces of recording medium may be shortened with the plurality of platens, a printable area in each recording medium is still fixed and limited to the size of the platens. When it is desired that an image larger than the size of the platen is printed on paper, for example, the image can be divided into a plurality of pieces, and each piece can be printed on a sheet of paper which is in a suitable size for one of the platens and patched into a piece thereafter. However, when it is desired that the image larger than the size of the platen to be printed on fabric, for example, alignment of each piece of the printed fabric has been difficult due to stretches, shrinks, and deformation of the fabric. Therefore, the divisional printing to achieve a larger printed image has been substantially inapplicable to fabric. Moreover, when the recording medium is a ready-sewn cloth such as a T-shirt, relocating the cloth in an intended printing position in the printing apparatus in order to achieve the larger printed image is difficult, because various parts of the cloth such as sleeves and seams may interfere with a printing unit (e.g., a print head) of the printing apparatus. 
       SUMMARY  
       [0007]    In view of the above, the present invention is advantageous in that a printing apparatus having a plurality of media-holders and capable of printing a larger image is provided. 
         [0008]    According to an aspect of the invention, there is provided a printing apparatus capable of forming an image on a recording medium, having a recording head to eject ink onto the recording medium, a recording head controller to control movement of the recording head according to printing data, which represents the image to be formed on the recording medium, a carriage to carry the recording head in a main scanning direction relative to the recording medium, a plurality of platens, each of which has a holding surface to hold the recording medium thereon and is movable respectively in an auxiliary direction, which is perpendicular to the main scanning direction, and a plurality of drive mechanisms, each of which drives one of the platens in the auxiliary direction. The plurality of platens can be moved synchronously with one another. 
         [0009]    With the printing apparatus according to the above configuration, a printable area in which the image is formed can be extended with the plurality of platens synchronously moved. 
     
    
     
       BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS  
         [0010]      FIG. 1  is a top plane view of an inkjet printer according to a first embodiment of the present invention. 
           [0011]      FIG. 2  is a front view of the inkjet printer according to the first embodiment of the present invention. 
           [0012]      FIG. 3  is a block diagram to illustrate an electrical configuration of the inkjet printer according to the first embodiment of the present invention. 
           [0013]      FIG. 4  is an illustrative top view of a first drive mechanism according to the first embodiment of the present invention. 
           [0014]      FIG. 5  is an illustrative side view of the first drive mechanism according to the first embodiment of the present invention. 
           [0015]      FIG. 6  is a perspective view of an extensible platen according to the first embodiment of the present invention. 
           [0016]      FIG. 7  is a top plane view of the inkjet printer with the extensible platen placed over a first platen and a second platen according to the first embodiment of the present invention. 
           [0017]      FIG. 8  is a front view of the inkjet printer with the extensible platen placed over the first platen and the second platen according to the first embodiment of the present invention. 
           [0018]      FIG. 9A  is a perspective view of the extensible platen to be placed over the first platen and the second platen according to the first embodiment of the present invention, and  FIG. 9B  is an illustrative side view of the extensible platen to be placed over the first platen and the second platen according to the first embodiment of the present invention. 
           [0019]      FIG. 10  is an illustrative side view of the first platen with the extensible platen placed over the first platen and the second platen according to the first embodiment of the present invention. 
           [0020]      FIG. 11  is an illustrative side view of the first platen without the extensible platen according to the first embodiment of the present invention. 
           [0021]      FIG. 12  is a flowchart to illustrate a printable area inspecting process to be executed by a CPU of the inkjet printer according to the first embodiment of the present invention. 
           [0022]      FIG. 13  is a flowchart to illustrate a printing process to be executed by the CPU of the inkjet printer according to the first embodiment of the present invention. 
           [0023]      FIG. 14  is a front view of the inkjet printer with recording media over the first platen and the second platen respectively according to the first embodiment of the present invention. 
           [0024]      FIG. 15  is an illustrative view of a screen to display an image to be printed by the inkjet printer according to the first embodiment of the present invention. 
           [0025]      FIG. 16  is a front view of the inkjet printer with a recording medium over the first platen and the second platen according to the first embodiment of the present invention. 
           [0026]      FIG. 17  is an illustrative view of the screen to display a larger image to be printed by the inkjet printer according to the first embodiment of the present invention. 
           [0027]      FIG. 18  is a flowchart to illustrate a printing process according to a second embodiment of the present invention. 
           [0028]      FIG. 19  is a front view of an inkjet printer with a third platen in addition to the first platen and the second platen according to a third embodiment of the present invention. 
           [0029]      FIG. 20  is a front view of the inkjet printer with a larger-seized extensible platen placed over the first platen, the second platen, and the third platen according to the third embodiment of the present invention. 
           [0030]      FIG. 21  is a front view of the inkjet printer with an extensible platen placed over the second platen and the third platen according to the third embodiment of the present invention. 
           [0031]      FIG. 22  is a front view of the inkjet printer with a recording medium over the extensible platen covering the second platen and the third platen according to the third embodiment of the present invention. 
           [0032]      FIG. 23  is a front view of the inkjet printer with the recording medium over the extensible platen covering the first platen and the second platen according to the third embodiment of the present invention. 
           [0033]      FIG. 24  is a front view of the inkjet printer with the recording medium over the extensible platen covering the first platen and the second platen according to the third embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION  
       [0034]    Hereinafter, embodiments according to aspects of the present invention will be described with reference to the accompanying drawings. 
         [0035]    An inkjet printer  1  according to an embodiment of the present invention will be described with reference to  FIGS. 1 through 3 .  FIG. 1  is a top plane view of the inkjet printer  1  according to the embodiment of the present invention.  FIG. 2  is a front view of the inkjet printer  1  according to the embodiment of the present invention.  FIG. 3  is a block diagram to illustrate an electrical configuration of the inkjet printer  1  according to the embodiment of the present invention. 
         [0036]    The inkjet printer  1  according to the present embodiment is a known inkjet printer having an inkjet head  21 , from which inks are ejected onto a recording medium. The recording medium in the present embodiment is fabric, more specifically a T-shirt, and an image according to image data inputted in the inkjet printer  1  from an external data processing apparatus is formed on the T-shirt. As shown in  FIGS. 1 and 2 , the inkjet printer  1  is provided with a base  2  at a bottom thereof and a casing  10  to cover an entire configuration of the inkjet printer  1 . Further, the inkjet printer  1  is provided with a rear casing  10 A at a rear end thereof. 
         [0037]    In the present embodiment, a left-hand side which appears in  FIG. 1  is the front side of the inkjet printer  1 , and an upper side in  FIG. 1  and a left-hand side in  FIG. 2  correspond to the left end of the inkjet printer  1 . Accordingly, a lower side in  FIG. 1  and a right-hand side in  FIG. 2  correspond to the right end of the inkjet printer  1 . In addition, a direction, in which the inkjet head  21  mounted on a carriage  13  is reciprocated, corresponds to a main scanning direction (i.e., a vertical direction in  FIG. 1 ) of the inkjet head  21 . 
         [0038]    In side the casing  10 , the inkjet printer  1  is provided with a known inkjet printing mechanism, which includes the inkjet head  21 , the carriage  13 , and a guide rail  11 . The guide rail  11  is arranged in parallel with the main scanning direction to guide the carriage  13  with the inkjet head  21  there-along. Further, a carriage motor  24 , a pulley (not shown), and a carriage belt (not shown) are provided. The carriage motor  24  is in vicinity to one end (an upper end in  FIG. 1  in the present embodiment) of the guide rail  11 , and the pulley is in vicinity to the other end (a lower end in  FIG. 1 ). The carriage belt is provided to connect the carriage motor  24  and the pulley. The carriage belt is fixed to a rear side of the carriage  13  so that the carriage  13  can be reciprocated along the guide rail  11  as the carriage belt is driven by the carriage motor  24 . In addition, the inkjet printer  1  is provided with a maintenance unit (not shown) including a capping mechanism, a wiper mechanism, and a purging mechanism for the inkjet head on one of the ends of the guide rail  11 . 
         [0039]    Next, platens of the inkjet printer  1  according to the present embodiment to hold the recording medium will de described. The inkjet printer  1  is provided with a pair of platens, a first platen  5  and a second platen  6 , which are identical to each other. The first platen  5  and the second platen  6  are movable in parallel with an auxiliary scanning direction, which is substantially perpendicular to the main scanning direction of the inkjet head  21  (i.e., a horizontal direction in  FIG. 1 ). 
         [0040]    In order to drive the platens  5 ,  6 , in the auxiliary direction respectively, the inkjet printer  1  is provided with a first drive mechanism  7  and a second drive mechanism  8 , which are arranged in parallel with each other. The first drive mechanism  7  is to drive the first platen  5  and includes guide rails  7 A,  7 B (see  FIG. 2 ) and a first platen drive motor  71 . The first platen drive motor  71 , which is a stepping motor in the present embodiment, is arranged on one end (a right-hand end in  FIG. 1 ) of each of the guide rails  7 A,  7 B. As the first platen drive motor  71  is activated, the first platen  5  is reciprocated in the auxiliary direction along the guide rails  7 A,  7 B. As shown in  FIG. 1 , the first platen drive motor  71  is arranged in vicinity to a rear end (the right-hand end in  FIG. 1 ) in the casing  10 . Similarly, the second drive mechanism  8  is provided to drive the second platen  6  and includes guide rails  8 A,  8 B (see  FIG. 2 ) and a second platen drive motor  81 , which is a stepping motor. The second platen  6  is reciprocated in the auxiliary direction along the guide rails  8 A,  8 B as the second platen drive motor  81  is activated. The second platen drive motor  81  is arranged in vicinity to the rear end (the right-hand end in  FIG. 1 ) in the casing  10 . 
         [0041]    Each of the first platen  5  and the second platen  6  is formed to have a pentagonal shape in a plane view. More specifically, a front end of each platen is formed in an obtuse V-like shape protruding toward the front of the inkjet printer  1  so that the recording medium (i.e., a T-shirt in the present embodiment) can be placed horizontally over a top surface of the platen. 
         [0042]    As shown in  FIG. 2 , trays  4  having surfaces which are substantially parallel with the top surfaces of the first and the second platens  5 ,  6  are provided at positions below the first and the second platens  5 ,  6 . The trays  4  are provided to receive overhanging portions of the recording medium such as sleeves of the T-shirt, which are not held by the platens  5 ,  6 , so that the trays  4  can prevent the overhanging portions from interfering the base  2  when the T-shirt is installed on the first platen  5  and the second platen  6 . 
         [0043]    The inkjet printer  1  is provided with an ink cartridge storage unit  33 , in which ink cartridges  33 A,  33 B are stored, on the right-hand side in the casing  10 , as shown in  FIG. 2 . Each of the ink cartridges  34 A,  34 B, containing CMYK (cyan, magenta, yellow, and black) inks, is connected to the inkjet head  21  through an ink supplying tube (not shown). 
         [0044]    As shown in  FIGS. 1 and 2 , the inkjet printer  1  is further provided with an operation panel  28  on the right-hand side of the front thereof. The operation panel  28  includes a plurality of operation buttons, through which a user&#39;s operations are inputted, such as a first print start button  29  to instruct printing and a cancel button  31  to instruct cancellation of the printing instruction. Further, the operation panel  28  includes a display  30  (an LCD (liquid crystal display) in the present embodiment) to display various information, a data lamp  36  to indicate reception of data, and an error lamp  36  to indicate an operation error. The ink cartridge storage unit  33  is arranged below the operation panel  28 . 
         [0045]    As shown in  FIGS. 1 and 2 , the inkjet printer  1  is further provided with an operation panel  27  on the left-hand side of the front thereof. The operation panel  27  includes a second print start button  32  to instruct printing. The ink cartridge storage unit  34  is arranged below the operation panel  27 . 
         [0046]    Next, referring to  FIG. 3 , an electrical configuration of the inkjet printer  1  according to the present embodiment will be described.  FIG. 3  is a block diagram to illustrate the electrical configuration of the inkjet printer  1  according to the embodiment of the present invention. The inkjet printer  1  is provided with a print controlling unit  100 , including a CPU  110 , a ROM  120 , a RAM  130 , an inkjet head control unit  140 , a carriage motor drive unit  145 , a platen drive unit  147 , a sensor signal receiving unit  148 , and a display control unit  149 , which are connected with one another through a bus  115 . The CPU  110  controls entire operations of the inkjet printer  1 . The ROM  120  stores various controlling programs to be executed by the CPU  110 . The RAM  130  temporarily stores various data. The inkjet head control unit  140  controls activation/deactivation of piezoelectric actuators, which are provided in each channel in the inkjet head  21 . The carriage motor drive unit  145  controls movement of the carriage motor  24 . The platen drive unit  147  controls activation of the first platen drive motor  71  and the second platen drive motor  81 . The sensor signal receiving unit  148  receives signals from the first print start button  29 , the second print start button  32 , the cancel button  31 , and an extensible platen sensor  52 , which will be described later. The display control unit  149  controls the data lamp  35 , the error lamp  36 , and the display  30 . Further, the inkjet printer  1  is provided with a communication unit  125 , which connects the inkjet printer  1  with an external PC (personal computer  90 ) through a USB (universal serial bus)  150 . Optionally, the connection between the inkjet printer  1  and the external PC may be provided through a parallel communication interface. 
         [0047]    Next, referring to  FIGS. 4 and 5 , the first drive mechanism  7  to drive the first platen  5  will be described.  FIG. 4  is an illustrative top view of the first drive mechanism  7  according to the embodiment of the present invention.  FIG. 5  is an illustrative side view of the first drive mechanism according to the embodiment of the present invention. The left-hand side which appears in  FIGS. 4 and 5  corresponds to the front of the inkjet printer  1 , and the right-hand side which appears in  FIGS. 4 and 5  corresponds to the rear of the inkjet printer  1 . 
         [0048]    The first drive mechanism  7  is provided with a motor pulley  73 , a greater pulley  72 , and a motor belt  79 , and the motor belt  79  encircles the motor pulley  73  and the greater pulley  72 . As the first platen drive motor  71  rotates, the motor pulley  73  is rotated, and the greater pulley  72  is rotated accordingly. The first drive mechanism  7  is provided with a first belt pulley  74 , which is attached to the greater pulley  72  to rotate coaxially and in synchronization with the greater pulley  72 . The first platen drive motor  71 , the motor pulley  73 , the greater pulley  72 , and the first belt pulley  74  are arranged in the casing  10  in positions lower than a horizontal plane on which the first platen  5  is shifted. Further, a timing belt  78  is provided to encircle the first belt pulley  74  and a second belt pulley  75 . The second belt pulley  75  is provided in a position closer to the front of the inkjet printer  1  (i.e., on the left-hand side in  FIGS. 1 ,  4 , and  5 ). A diameter of the second belt pulley  75  is substantially equivalent to a diameter of the first belt pulley  74 . 
         [0049]    In the inkjet printer  1 , the first belt pulley  74  and the second belt pulley  75  are arranged in positions such that a line connecting a rotation axis of the first belt pulley  74  and a center of the second belt pulley  75  is perpendicular to the main scanning direction of the inkjet head  21  (i.e., an axial direction of the guide rail  11 ), and the timing belt  78  is oriented perpendicularly to the main scanning direction of the inkjet head  21 . The timing belt  78  is fixed to the first platen  5  by a platen attachment  51  so that the first platen  5  is shifted in a direction indicated by an arrow A in  FIG. 4  (i.e., the auxiliary scanning direction and a front-rear direction of the inkjet printer  1 ) as the timing belt  78  is shifted in accordance with rotation of the first belt pulley  74 . Thus, rotation of the first platen drive motor  71  is conveyed to the motor pulley  73 , the motor belt  79 , the greater pulley  72 , the first belt pulley  74 , the timing belt  78 , the second belt pulley  75 , and the platen attachment  51 , and thus converted into horizontal movement to shift the first platen  5  in the auxiliary direction. 
         [0050]    Hereinafter, the first platen drive motor  71  according to the present embodiment will be described. The first platen drive motor  71  is a known 1-2 phase-exciting stepping motor, having an electromagnetic stator to surround a rotor. The rotor is attracted to the stator as the stator is excited in an order and rotated. Specifically, the stator has four excitation phases, which are phase A, phase B, phase reverse-A, and phase reverse-B, arranged in a clockwise direction. The stator is excited in an order phase A only, phases A and B, phase B only, phases B and reverse-A, phase reverse-A only, phases reverse-A and reverse-B. As the excited phase is positively polarized in N, the negative (S) pole of the rotor is attracted thereto, and the positive (N) pole of the rotor is repelled. Thus, the rotor is rotated step-by-step. 
         [0051]    According to such continuous excitation, the first platen drive motor  71  can be rotated, and the first platen  5  is shifted in the auxiliary direction of the inkjet printer  1 . An angle of the rotor to be rotated in one cycle of excitation is determined by a number of the positive poles and the negative poles, and a length of the first platen  5  to be shifted is controlled by a number of the rotating steps of the rotor. In the present embodiment, the second drive mechanism  8  to drive the second platen  6  is configured similarly to the first drive mechanism  7 . 
         [0052]    Next, referring to  FIGS. 6 to 11 , an extensible platen  40  according to the present embodiment will be described.  FIG. 6  is a perspective view of the extensible platen  40  according to the embodiment of the present invention.  FIG. 7  is a top plane view of the inkjet printer  1  with the extensible platen  40  placed over the first platen  5  and the second platen  6  according to the embodiment of the present invention.  FIG. 8  is a front view of the inkjet printer with the extensible platen placed over the first platen and the second platen according to the first embodiment of the present invention.  FIG. 9A  is a perspective view of the extensible platen to be placed over the first platen and the second platen according to the first embodiment of the present invention, and  FIG. 9B  is an illustrative side view of the extensible platen to be placed over the first platen and the second platen according to the first embodiment of the present invention.  FIG. 10  is an illustrative side view of the first platen  5  with the extensible platen  40  placed over the first platen  5  and the second platen  6  according to the embodiment of the present invention.  FIG. 11  is an illustrative side view of the first platen  5  without the extensible platen  40  according to the embodiment of the present invention. 
         [0053]    As shown in  FIGS. 6 ,  8 ,  9 A, and  9 B, the extensible platen  40  is formed to have a rectangular shape and a size to substantially cover the first platen  5  and the second platen  6 . When in use, as shown in  FIGS. 7 and 8 , the extensible platen  40  is placed over the first platen  5  and the second platen  6  to cover them entirely. The extensible platen  40  is provided with rim portions  40   a  (see  FIGS. 9A and 9B ), by which one side of the first platen  5  and an opposite side of the second platen (a side symmetrically corresponding to the one side of the first platen  5 ) are held. Thus, the extensible platen  40  couples the first platen  5  and the second platen  6  integrally. Further, the extensible platen  40  is provided a protrusion  41 , made of a light-blocking material, which protrudes downward. The protrusion  41  is inserted in an extensive platen sensor  52 , which will be described later, to prevent a photo-receiver (not shown) from receiving light emitted from a light-emitter (not shown). Thus, attachment and detachment of the extensible platen  40  can be detected by the extensible platen sensor  52 . 
         [0054]    Next, the extensible platen sensor  52  will be described. As shown in  FIG. 7 , the extensible platen sensor  52 , having the light-emitter and the light-receiver, is an optical coupler arranged on the rear side of the first platen  5 . As shown in  FIGS. 7 ,  8 , and  10 , when the extensible platen  40  is placed over the first platen  5  and the second platen  6  to integrally couple them, the protrusion  41  is inserted in between the light-emitter and the light-receiver to block the light emitted from the light-emitter. In this state, the extensible platen sensor  52  is switched on. When the extensible platen  40  is removed from the inkjet printer  1 , as shown in  FIG. 11 , the protrusion  41  between the light-emitter and the light-receiver is removed as well. Thus, the extensible platen sensor  52  is switched off. 
         [0055]    Next, referring to  FIG. 12 , a printable area inspecting process will be described.  FIG. 12  is a flowchart to illustrate the printable area inspecting process to be executed by the CPU  110  of the inkjet printer  1  according to the embodiment of the present invention. When the process starts, in S 1 , it is judged as to whether printable data transmitted from the PC  90  is received in the communication unit  125  through the USB  150 . If the printable data is received (S 1 : YES), in S 2 , it is judged as to whether the extensible platen sensor  52  is switched on (i.e., the extensible platen  40  is attached). The printable data received in S 1  is stored in the RAM  130  (see  FIG. 3 ). 
         [0056]    In S 2 , if it is judged that the extensible platen sensor  52  is switched on (S 2 : YES) and the extensible platen  40  is attached, in S 3 , a printable area for the printable data is set according to the size of the extensible platen  40 . In the present embodiment, the printable area is set to be 16 inches by 32 inches. The printable area set in S 3  is stored in the RAM  130 . In S 2 , if it is judged that the extensible platen sensor  52  is switched off and the extensible platen  40  is not attached (S 2 : NO), in S 4 , the printable area is set according to the size of the first platen  5  or the second platen  6 . In the present embodiment, the printable area is set to be 14 inches by 16 inches. The printable area set in S 4  is stored in the RAM  130 . It should be noted that the sizes of the printable area set in S 3  and S 4  are merely an example and can be determined in advance according to the sizes of the first and second platens  5 ,  6  and the extensible platen  40 . 
         [0057]    Following S 3  or S 4 , in S 5 , an image represented by the printable data store in the RAM  130  can fit in the printable area set in S 3  or S 4 . If it is judged that the image should not fit (S 5 : NO), in S 6 , a notification to notify the inconsonance is given to the user through the display  30 . If it is judged that the image should fit (S 5 : YES), the process is terminated. 
         [0058]    In S 1 , when no printable data is received (S 1 : NO), the process is terminated. The printable area inspecting process is repeated as an interrupting action within an interval of a millisecond time scale to monitor reception of printable data. 
         [0059]    Next, referring to  FIG. 13 , a printing process to be executed by the CPU  110  of the inkjet printer  1  according to the present embodiment will be described.  FIG. 13  is a flowchart to illustrate the printing process according to the embodiment of the present invention. When the process starts, in S 11 , it is judged as to whether the first print start button  29  is pressed. If it is judged that the first print start button  29  is pressed (S 11 : YES), in S 12 , it is judged as to whether the extensible platen sensor  52  is switched on. In S 12 , if it is judged that the extensible platen sensor  52  is on (i.e., the extensible platen  40  is attached) (S 12 : YES), in S 13 , the first platen drive motor  71  and the second platen drive motor  81  are driven synchronously. In this step, the first platen drive motor  71  and the second platen drive motor  81  are driven simultaneously for a same amount in a same direction based on the printable data received in S 1  (see  FIG. 12 ). In S 12 , if it is judged that the extensible platen sensor  52  is switched off (S 12 : NO), in S 14 , solely the first platen drive motor  71  is driven based on the printable data received in S 1  ( FIG. 12 ). 
         [0060]    In S 11 , if it is judged that the first print start button  29  is not pressed (S 11 : NO), in S 15 , it is judged as to whether the second print start button  32  is pressed. In S 15 , if it is judged that the second print start button  32  is pressed (S 15 : YES), in S 16 , it is judged as to whether the extensible platen sensor  52  is switched on. If it is judged that the extensible platen sensor  52  is switched on, i.e., the extensible platen  40  is attached (S 16 : YES), in S 13 , the first platen drive motor  71  and the second platen drive motor  81  are driven synchronously. In S 16 , if it is judged that the extensible platen sensor  52  is switched off (S 16 : NO), in S 17 , solely the second platen drive motor  81  is driven based on the printable data received in S 1  ( FIG. 12 ). 
         [0061]    Following S 13 , S 14 , or S 17 , in S 18 , the carriage motor  24  is driven, and in S 19 , the inkjet head  21  is driven based on the printable data received in S 1  ( FIG. 12 ). In S 20 , it is judged as to whether the printable data indicates an end thereof. If it is judged that the printable data remains (S 20 : NO), the process returns to S 18 . In S 20 , if it is judged that the end of the printable data is indicated (S 20 : YES), the inkjet head  21  is stopped, and in S 21 , the inkjet head  21  is moved to a position in the maintenance unit. In S 22 , the first platen  5  and/or the second platen  6  are moved to positions wherein the user can remove the fabric from the first platen  5 , the second platen  6 , or the extensible platen  40 . 
         [0062]    Next, referring to  FIGS. 2 ,  14 , and  15 , a configuration of the inkjet printer  1  in which a same image is printed on two pieces of fabrics respectively will be described.  FIG. 14  is a front view of the inkjet printer  1  with the T-shirts as the recording media over the first platen  5  and the second platen  6  respectively according to the embodiment of the present invention.  FIG. 15  is an illustrative view of a screen to display an image to be printed according to the printable data by the inkjet printer  1  according to the embodiment of the present invention. In the present embodiment, the screen is shown on a display (not shown) of the PC  90 . When the same image is printed on two T-shirts  60 ,  61  respectively, as shown in  FIG. 15 , printable data representing the image to be printed is created in the PC  90  and transmitted to the inkjet printer  1 . In the present embodiment, for example, a size of the image to be printed is 14 inches by 16 inches. 
         [0063]    When the extensible platen  40  is not attached over the first and second platens  5 ,  6 , and the first print start button  29  is pressed, the image is printed on the T-shirt  61 , which is held by the first platen  5 . Thereafter, without the extensible platen  40 , when the second print start button  32  is pressed, the image is printed on the T-shirt  60 , which is held by the second platen  6 . In the above operation, the user is required to create the printable data in the PC  90  solely for the one image to be printed on one of the recording media (i.e., the T-shirts  60 ,  61 ) and is not required to prepare a duplicate of the image for the second image to be printed on the T-shirt  61 . It is noted that the inkjet printer  1  can be configured such that the operation panel  28  is provided with a simultaneous print start button, which is pressed to start simultaneous printing for the T-shirts  60 ,  61 . In this configuration, when the simultaneous print start button is pressed, the CPU  110  examines as to whether the extensible platen  40  is attached over the first and the second platens  5 ,  6 . If it is judged that the extensible platen  40  is not attached, the first and the second platens  5 ,  6  are synchronously driven so that the same image can be printed on the T-shirts  60 ,  61  respectively. 
         [0064]    Next, referring to  FIGS. 8 ,  16 , and  17 , a configuration of the inkjet printer  1  in which a single larger image is printed on one piece of fabric will be described.  FIG. 16  is a front view of the inkjet printer  1  with a T-shirt  62  over the first platen  5  and the second platen  6  according to the embodiment of the present invention.  FIG. 17  is an illustrative view of a screen to display the larger image to be printed by the inkjet printer  1  according to the embodiment of the present invention. In the present embodiment, the screen is shown on the display of the PC  90 . When the larger image is printed on the T-shirt  62 , as shown in  FIG. 17 , printable data representing the larger image to be printed is created in the PC  90  and transmitted to the inkjet printer  1 . In the present embodiment, for example, a size of the larger image to be printed is 16 inches by 32 inches. When the larger image is printed, as shown in  FIG. 8 , the extensible platen  40  is placed over the first platen  5  and the second platen  6 , and the T-shirt  62  is laid over the extensible platen  40  as shown in  FIG. 16 . Thus, the larger image, which has a size of 16 inches by 32 inches in the present embodiment, can be printed on a larger printable area. It is noted that in this configuration, as shown in  FIG. 16 , the T-shirt  62  is placed over the extensible platen  40  with its longitudinal center line (i.e., a vertical center line when the T-shirt  62  is worn) oriented parallel with the main scanning direction in the inkjet printer  1 , while the T-shirts  60 ,  61  are placed over the first platen  5  and the second platen  6  respectively with the longitudinal center lines thereof being perpendicular to the main scanning direction. Therefore, as shown in  FIG. 17 , the larger image shown in the screen is rotated at 90 degrees to the left so that the larger image can be printed on the T-shirt  62  in a correct orientation. 
         [0065]    Next, referring to  FIG. 18 , a printing process to be executed by the CPU  110  of the inkjet printer  1  according to a second embodiment of the present invention will be described. In the present embodiment, a configuration of the inkjet printer identical to the configuration of the inkjet printer  1  in the first embodiment is referred to by an identical reference numeral, and description of that will be omitted.  FIG. 18  is a flowchart to illustrate the printing process according to the second embodiment of the present invention. In the present embodiment, the first platen drive motor  71  is configured to have substantial power to drive the first platen  5  and the second platen  6  with a extensible platen  40  thereonto so that the first platen  5  along with the second platen  6  and the extensible platen  40  with the T-shirt  62  can be driven solely by the first platen drive motor  71 . When the second platen  6  and the extensible platen  40  are driven along with the first platen  5  are driven by the first platen drive motor  71 , excitation to the second platen drive motor  81  is refrained. Meanwhile, the second platen drive motor  81  can be configured to have power to drive solely the second platen  6 . 
         [0066]    When the process starts, in S 21 , it is judged as to whether the first print start button  29  is pressed. If it is judged that the first print start button  29  is pressed (S 21 : YES), in S 22 , it is judged as to whether the extensible platen sensor  52  is switched on. In S 22 , if it is judged that the extensible platen sensor  52  is switched on (i.e., the extensible platen  40  is attached) (S 22 : YES), in S 23 , the second platen drive motor  81  is refrained from being excited, and solely the first platen drive motor  71  is driven based on the printable data received in S 1  ( FIG. 12 ). In S 22 , if it is judged that the extensible platen sensor  52  is switched off (S 22 : NO), in S 24 , the first platen drive motor  71  is driven based on the printable data received in S 1  ( FIG. 12 ). 
         [0067]    In S 21 , if it is judged that the first print start button  29  is not pressed (S 21 : NO), in S 25 , it is judged as to whether the second print start button  32  is pressed. In S 25 , if it is judged that the second print start button  32  is pressed (S 25 : YES), in S 26 , it is judged as to whether the extensible platen sensor  52  is switched on. If it is judged that the extensible platen sensor  52  is switched on, i.e., the extensible platen  40  is attached (S 26 : YES), in S 23 , the second platen drive motor  81  is refrained from being excited, and solely the first platen drive motor  71  is driven based on the printable data received in S 1  ( FIG. 12 ). In S 26 , if it is judged that the extensible platen sensor  52  is switched off (S 26 : NO), in S 27 , solely the second platen drive motor  81  is driven based on the printable data received in S 1  ( FIG. 12 ). 
         [0068]    Following S 23 , S 24 , or S 27 , in S 28 , the carriage motor  24  is driven, and in S 29 , the inkjet head  21  is driven based on the printable data received in S 1  ( FIG. 12 ). In S 30 , it is judged as to whether the printable data indicates an end thereof. If it is judged that the printable data remains (S 30 : NO), the process returns to S 28 . In S 30 , if it is judged that the end of the printable data is indicated (S 30 : YES), the inkjet head  21  is stopped, and in S 31 , the inkjet head  21  is moved to a position in the maintenance unit. In S 32 , the first platen  5  and the second platen  6  are moved to positions wherein the user can remove the fabric from the first platen  5 , the second platen  6 , or the extensible platen  40 . 
         [0069]    As has been described above, the inkjet printer  1  according to the above embodiments is provided with the first platen  5 , the second platen  6 , and the extensible platen  40  which can be attached over the first platen  5  and the second platen  6 . With the extensible platen  40  being attached over the first platen  5  and the second platen  6 , a larger printable area than the printable areas provided by one of the first platen  5  and the second platen  6  can be provided. In addition, with the extensible platen sensor  52 , the first platen  5  and the second platen  6  can be driven synchronously (with or without excitation of the second platen drive motor  81 ) when the extensible platen  40  attached over the first platen  5  and the second platen  6  is detected. Meanwhile, when the extensible platen  40  is not detected by the extensible platen sensor  52 , the first platen  5  and the second platen  6  can be separately driven. In this configuration, the printable area can be enlarged according to the size of the extensible platen  40  by attaching the extensible platen  40  in the inkjet printer  1 . Further, a same image can be printed on a plurality of pieces of fabrics by simply creating one image and transmitting the image to the inkjet printer  1  without the extensible platen  40 . Thus, platens to suitably hold the recording media can be used according to the size of the image and the size of the recording medium so that printing time and productivity to print the image can be optimized. 
         [0070]    Although examples of carrying out the invention have been described, those skilled in the art will appreciate that there are numerous variations and permutations of the printing apparatus that fall within the spirit and scope of the invention as set forth in the appended claims. It is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or act described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims. 
         [0071]    For example, the extensible platen sensor  52  can be provided to the second platen  6  rather than the first platen  5 . Further, a third platen  9  formed identically to the first platen  5  and the second platen  6  can be provided (see  FIG. 19 ).  FIG. 19  is a front view of an inkjet printer  101  with the third platen  9  in addition to the first platen  5  and the second platen  6  according to a third embodiment of the present invention. In the inkjet printer  101 , the third platen  9  is guided by the guide rails  12 A,  12 B and driven by a third platen drive motor (not shown). 
         [0072]    In the inkjet printer  101 , a larger-sized extensible platen  42  which covers the first platen  5 , the second platen  6 , and the third platen  9  can be attached so that a larger printable area can be provided (see  FIG. 20 ).  FIG. 20  is a front view of the inkjet printer  101  with the larger-seized extensible platen  42  placed over the first platen  5 , the second platen  6 , and the third platen  9  according to the third embodiment of the present invention. Further, the inkjet printer  101  can be provided with an extensible platen  43 , which can cover two of the three platens  5 ,  6 ,  9 .  FIG. 21  is a front view of the inkjet printer  101  with the extensible platen  43  placed over the second platen  6  and the third platen  9  according to the third embodiment of the present invention. In this configuration, a T-shirt  63  can be held by the extensible platen  43  which is placed over the second platen  6  and the third platen  9  (see  FIG. 22 ).  FIG. 22  is a front view of the inkjet printer  101  with the T-shirt  63  over the extensible platen  43  covering the second platen  6  and the third platen  9  according to the third embodiment of the present invention. However, the extensible platen  43  can be attached over the first platen  5  and the second platen  6  (see  FIG. 23 ).  FIG. 23  is a front view of the inkjet printer  101  with the T-shirt  63  over the extensible platen  43  covering the first platen  5  and the second platen  6  according to the third embodiment of the present invention. In this configuration, the T-shirt  63  can be held by the extensible platen  43  which is placed over the first platen  5  and the second platen  6  (see  FIG. 24 ).  FIG. 24  is a front view of the inkjet printer  101  with the T-shirt  63  over the extensible platen  43  covering the first platen  5  and the second platen  6  according to the third embodiment of the present invention. 
         [0073]    In the inkjet printer  101  in the third embodiment, the extensible platen sensor  52  can be provided to each of the first platen  5 , the second platen  6 , and the third platen  9 . Meanwhile, the extensible platen  42  can be provided with three protrusions  41 , which are inserted into each of the extensible platen sensors  52  provided to the first platen  5 , the second platen  6 , and the third platen  9 . The extensible platen  43  can be provided with two protrusions  41 , which are inserted into two of the extensible platen sensors  52  provided to the first platen  5 , the second platen  6 , and the third platen  9 . With this configuration, the print controlling unit  100  of the inkjet printer  101  can determine which extensible platen between the extensible platen  42  and the extensible platen  43  is attached. Similarly, the number of the platens can be arbitrarily increased.