Abstract:
A printing device has a platen roller, a print head for printing on a sheet material, and a sheet cutting device for cutting the sheet material on which printing has been performed. The sheet cutting device has a stationary blade and a movable blade for cutting the sheet material in a pressing contact state with respect to the stationary blade. A release mechanism is disposed in the stationary blade frame and is movable to first and second positions to release the stationary and movable blades. In the first position of the release mechanism, the blades are in the pressing contact state, the platen roller is in contact with the print head, and ends of a platen roller shaft of the platen roller are disposed adjacent to one end of respective elongated holes of a stationary blade frame supporting the stationary blades. In the second position of the release mechanism, the blades are moved out of the pressing contact state, the platen roller is in contact with the print head, and the ends of the platen roller shaft are disposed adjacent to the other end of the respective elongated holes of the stationary blade frame.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a sheet cutting device for cutting a sheet material by a stationary blade and a movable blade after performing printing on the sheet material such as roll paper, and to a printer including the sheet cutting device. 
     2. Description of the Related Art 
     Conventionally, as a printer which performs printing on a sheet material in a form of roll paper, there exist a printing device for performing printing on the sheet material sandwiched between a print head and a platen roller, and a printer including a sheet cutting device for cutting the sheet material on which the printing has been performed by the printing device. As the sheet cutting device included in the printer of this type, there is known a sheet cutting device in which a movable blade moves with respect to a stationary blade, thereby cutting a sheet material. 
     In the related art sheet cutting device, when the sheet material is being cut, due to paper jam, the movable blade is disabled in some cases. In this case, it is necessary that the sheet material being an obstacle for an operation of the movable blade be removed. In order to achieve this, various structures are adopted, for separating the stationary blade and the movable blade from each other. 
     For example, there is disclosed a structure in which, when one of the print head and the platen roller, to which the print head is pressed, of the printing device is moved from a printing operation position to a release position for removing the sheet material, the one of the print head and the platen roller and one of the movable blade and the stationary blade are moved together (see, Patent Document 1). 
     Further, for another related art sheet cutting device, there is disclosed a structure in which the movable blade is mounted onto a side of a support portion for supporting a platen roller, and when the platen roller is moved to the release position spaced apart from the print head, a press contact state between the movable blade and the stationary blade and connection between the movable blade and a drive mechanism for moving the movable blade are released, and with a removal of the sheet material being the obstacle for the operation of the movable blade, the movable blade returns to a cutting stand-by position spaced apart from the stationary blade (see, Patent Document 2).
     [Patent Document 1] JP 2002-219832 A   [Patent Document 2] JP 2004-237555 A   

     As disclosed in Patent Document 1, in the structure in which the stationary blade moves together with the print head or the platen roller, there is a risk of the print head or the platen roller being moved before a release operation in which the movable blade is moved with respect to the stationary blade to the cutting stand-by position. Further, there is a risk of the print head or the platen roller impacting on the movable blade which has not been completely moved to the cutting stand-by position. In order to prevent the impact between the movable blade and the print head or the platen roller, it is necessary that a space for moving the movable blade completely to the cutting stand-by position, that is, a space for ensuring a time for moving the movable blade to the cutting stand-by position be provided in the device. Thus, there is a problem in that the device as a whole is upsized. 
     Further, as disclosed in Patent Document 1, in a case of the structure in which the stationary blade or the movable blade is integrally moved together with the print head or the platen roller, a moving direction in which the print head and the platen roller are spaced apart from each other is regulated, so there is a problem in that an opening and closing direction with respect to a device main body is limited. 
     In a structure disclosed in Patent Document 2, there is required a retaining mechanism for a movable blade unit, formed of a separate member such as a cover or the like for a casing, for example, and a cutting operation cannot be performed by the printer alone. Accordingly, in a device of an automatic sheet insertion mechanism type, which does not require attachment and detachment of the print head or the platen roller of a printing portion, there is a problem of upsizing the device as a whole. 
     Further, also in the device of the automatic sheet insertion mechanism type as described above, when the sheet material is removed at the time of the paper jam in the printer, it is necessary that the print head or the platen roller of the printing portion be detachable. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a sheet cutting device and a printer enabling easy elimination of a sheet material inhibiting an operation of a movable blade at a time of paper jam, and capable of downsizing the device as a whole. 
     In order to achieve the above-mentioned object, according to the present invention, in a sheet cutting device having a stationary blade, which is disposed on a downstream side in a transporting direction of a sheet material with respect to printing means, for performing printing on the sheet material, a movable blade, which is moved to be close to and spaced apart from the stationary blade, for cutting the sheet material in a press contact state with respect to the stationary blade, and drive means for moving the movable blade with respect to the stationary blade, the stationary blade being disposed on the downstream side in the transporting direction of the sheet material with respect to the movable blade, the sheet cutting device includes: a stationary blade frame for supporting the stationary blade; a movable blade frame for supporting the movable blade; and a main frame which movably supports the stationary blade frame, and to which the movable blade frame is fixed. The stationary blade frame is provided movably with respect to the main frame so that the stationary blade is moved to a release position, where the press contact state between the stationary blade and the movable blade is released while retaining a position of the printing means. 
     In the sheet cutting device according to the present invention structured as described above, during cutting of the sheet material, when the movable blade is disabled due to the paper jam, while the position of the printing means is retained, the stationary blade frame is moved with respect to the main frame and the stationary blade frame is moved with respect to the main frame, thereby moving the stationary blade to the release position where the press contact state between the stationary blade and the movable blade is released. Further, in the sheet cutting device, when the movable blade is disabled due to the paper jam, while the position of the printing means is retained, the stationary blade frame is moved with respect to the main frame, thereby moving the stationary blade to the release position, and the movable blade is moved to a cutting stand-by position. Accordingly, when the stationary blade is moved together with the printing means as in the related art, the printing means is reliably prevented from impacting on the movable blade. Therefore, unlike in the related art device, in the sheet cutting device, it is not necessary to provide therein a space for ensuring a time for moving the movable blade to the cutting stand-by position, so the device is downsized as a whole. 
     Further, a moving member included in the sheet cutting device according to the present invention preferably includes a press contact member for bringing the stationary blade into press contact with the movable blade, and by a relatively simple structure, the stationary blade frame can be moved with respect to the main frame. 
     Further, each of the main frame and the stationary blade frame included in the sheet cutting device according to the present invention is preferably provided with positioning means for positioning the stationary blade frame with respect to the main frame. With this structure, the stationary blade frame can be reliably positioned in a predetermined position with respect to the main frame. Accordingly, there is no need of a separate member, and the cutting by the sheet cutting device alone is enabled. 
     Further, the sheet cutting device according to the present invention preferably includes transmission releasing means for disconnecting the movable blade and the drive means from each other when the stationary blade frame is moved with respect to the main frame. With this structure, the movable blade can be easily moved to the cutting stand-by position spaced apart from the stationary blade side. 
     Further, the stationary blade frame included in the sheet cutting device according to the present invention may be detachably provided to the main frame. 
     Further, according to the present invention, in a sheet cutting device having a stationary blade, which is disposed on a downstream side in a transporting direction of a sheet material with respect to printing means, for performing printing on the sheet material, a movable blade, which is moved to be close to and spaced apart from the stationary blade, for cutting the sheet material in a press contact state with respect to the stationary blade, and drive means for moving the movable blade with respect to the stationary blade, the movable blade being disposed on the downstream side in the transporting direction of the sheet material with respect to the stationary blade, the sheet cutting device includes: a stationary blade frame for supporting the stationary blade; a movable blade frame for supporting the movable blade; and a main frame which movably supports the movable blade frame, and to which the stationary blade frame is fixed. Further, the movable blade frame is provided movably with respect to the main frame so that the movable blade is moved to a release position, where the press contact state between the stationary blade and the movable blade is released while retaining a position of the printing means. 
     Further, a printer according to the present invention includes: the sheet cutting device of the present invention described above; and printing means for performing printing on the sheet material. 
     As described above, according to the present invention, the stationary blade frame or the movable blade frame is provided so as to be movable with respect to the main frame while the position of the printing means is retained, thereby enabling easy and reliable elimination of the sheet material inhibiting the operation of the movable blade at the time of paper jam and making it possible to downsize the device as a whole. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the accompanying drawings: 
         FIG. 1  is a perspective view showing a printer of an embodiment of the present invention; 
         FIG. 2  is a perspective view showing a sheet cutting device with a movable blade frame and a stationary blade frame being omitted; 
         FIG. 3  is a perspective view showing a state in which a stationary blade unit is removed from a main frame of the sheet cutting device; 
         FIG. 4  is a see-through side view showing a state where the stationary blade unit is positioned with respect to the main frame of the sheet cutting device; 
         FIG. 5  is a see-through side view showing a state where the stationary blade unit is removed from the main frame; 
         FIG. 6  is a see-through side view showing a state where regulation of a position of the stationary blade frame by a lock member is released; 
         FIG. 7  is a see-through side view showing a state where the stationary blade unit is moved with respect to the main frame; 
         FIG. 8  is a side view showing a state where a drive motor and a gear train of a cutter drive mechanism are engaged with each other; and 
         FIG. 9  is a side view showing a state where the drive motor and the gear train of the cutter drive mechanism are disengaged with each other. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Hereinafter, a specific embodiment of the present invention will be described with reference to the drawings. 
     A printer according to this embodiment is a printer in which printing is performed on the sheet material, and the sheet material is then cut to have a predetermined length, and in which a stationary blade frame is attached to a detachable platen roller of a printing device. For the sheet material used in the printer of this embodiment, there is employed so-called heat sensitive paper having a heat-sensitive printing layer provided on a surface side of a sheet-like base material. 
       FIG. 1  is a perspective view showing a printer of this embodiment.  FIG. 2  is a perspective view of a sheet cutting device with a movable blade frame and the stationary blade frame being omitted.  FIG. 3  is a perspective view showing a state in which a stationary blade unit is removed from a main frame of the sheet cutting device.  FIG. 4  is a see-through side view showing a state where the stationary blade unit is positioned with respect to the main frame.  FIG. 5  is a see-through side view showing a state where the stationary blade unit is removed from the main frame. 
     As shown in  FIGS. 1 and 4 , a printer  1  of this embodiment includes a printing device  11  for performing printing on a sheet material  5  and transporting the sheet material  5  in a direction indicated by an arrow a of  FIG. 1 , a sheet cutting device  12  for cutting the sheet material  5  on which printing has been performed by the printing device  11 , and a main frame  13  for supporting the printing device  11  and the sheet cutting device  12 . 
     The printing device  11  included in the printer  1  of this embodiment includes, as shown in  FIGS. 3 and 4 , a print head  21  for heating a heat-sensitive printing layer of the sheet material  5  to develop a color, a platen roller  22  with which the print head  21  is brought into press contact, a head supporting body  23  for supporting the print head  21 , a compression coil spring (not shown) for pressing the head supporting body  23  to the platen roller  22 , and a platen roller drive mechanism  24  for rotating the platen roller  22 . 
     Further, as shown in  FIG. 4 , the head supporting body  23  of the printing device  11  is movably supported by the main frame  13 , and by a biasing force of the compression coil spring, the print head  21  is brought into press contact with a peripheral surface of the platen roller  22 . 
     Further, as shown in  FIG. 2 , the platen roller drive mechanism  24  of the printing device  11  includes a print drive motor  25 , and a gear train  28  for transmitting a driving force by the print drive motor  25  to the platen roller  22 . The print drive motor  25  and the gear train  28  are supported by a side plate of the main frame  13 . 
     The sheet cutting device  12  included in the printer  1  includes, as shown in  FIG. 1 , a stationary blade unit  26  having a stationary blade  31  and a movable blade unit  27  having a movable blade  41 . 
     The stationary blade unit  26  of the sheet cutting device  12  includes, as shown in  FIG. 4 , the stationary blade  31 , a plate spring  32  (press contact member) for bringing the stationary blade  31  into press contact with the movable blade  41 , a stationary blade frame  33  for supporting the stationary blade  31 , a sheet guide  34  for supporting the sheet material  5  which is transported in the direction of the arrow a, a lock member  35  for regulating a position of the stationary blade frame  33  with respect to the main frame  13 , and a release lever  36  for releasing a locking state of the stationary blade frame  33  by the lock member  35 . 
     The stationary blade  31  of the stationary blade unit  26  is made of a flat plate-like material as shown in  FIG. 2 , and a blade edge thereof is formed in a straight shape. The plate spring  32  is supported by the stationary blade frame  33 , biases the stationary blade  31  in a direction of an arrow b of  FIG. 4 , and biases the lock member  35  in a direction of an arrow f of  FIG. 4 . The plate spring  32  also functions as a moving member for moving the stationary blade frame  33  with respect to the main frame  13  by a reaction force of the biasing force. 
     Further, as shown in  FIG. 4 , the stationary blade frame  33  for supporting the stationary blade  31  has, as positioning means for positioning the stationary blade frame  33  with respect to the main frame  13 , positioning grooves  33   c  engaging with a positioning protruding portion  13   b  for performing positioning with respect to the main frame  13 , and engagement grooves  33   a  with which a lock arm  35   a  of the lock member  35  described later is engaged, the positioning grooves  33   c  and the engagement grooves  33   a  being formed in side plates of the stationary blade frame  33 . Further, the side plate of the stationary blade frame  33  is formed with an elongated hole  33   b  by which a rotation shaft  22   a  of the platen roller  22  of the printing device  11  is supported. The elongated hole  33   b  moves with respect to the rotation shaft  22   a , thereby making the stationary blade frame  33  movable in a predetermined movable range with respect to the main frame  13 . 
     Further, as shown in  FIG. 4 , the sheet guide  34  is disposed on an upstream side in a transporting direction of the sheet material  5  with respect to the stationary blade  31  with a gap, in which the movable blade  41  can enter, being formed between the stationary blade  31  and the sheet guide  34 . The sheet guide  34  is formed with a guide surface  34   a  with which the sheet material  5  which is transported comes into slide contact. Further, when the movable blade  41  is moved with respect to the stationary blade  31  to allow the sheet material  5  to be cut, the sheet guide  34  supports the sheet material  5  over the blade edge of the stationary blade  31  and the guide surface  34   a  thereof, thereby suppressing relief of the sheet material  5  pressed by the movable blade  41  and preventing the sheet material  5  from being bent. Therefore, by the sheet guide  34 , the sheet material  5  is cut smoothly. 
     Further, as shown in  FIG. 4 , the lock member  35  of the stationary blade unit  26  has a lock arm  35   a  engaged with the stationary blade frame  33 . Further, as shown in  FIGS. 5 and 8 , the lock member  35  is formed with a position regulating surface  35   b  for regulating a position of a swing frame  49  of a cutter drive mechanism  45  described later. The release lever  36  of the stationary blade unit  26  is integrated with and fixed to the lock member  35  and is provided so as to be rotatable about the rotation shaft  22   a  of the platen roller  22 . 
     The movable blade unit  27  of the sheet cutting device  12  includes, as shown in  FIGS. 1 and 2 , the movable blade  41  which parallelly moves in directions of being closer to and spaced apart from the stationary blade  31 , that is, directions of arrows c 1  and c 2  of  FIG. 2 , a movable blade biasing spring (not shown) for biasing the movable blade  41  in the direction of the arrow c 2 , a movable frame (not shown) for moving the movable blade  41 , a movable blade frame  43  for supporting the movable blade  41  and the movable frame, and the cutter drive mechanism  45  connected to the movable frame, for parallelly moving the movable blade  41  in the directions of the arrows c 1  and c 2  with respect to the stationary blade  31 . 
     As shown in  FIG. 2 , the movable blade  41  of the movable blade unit  27  is formed of a flat plate-like material and has the blade edge formed in a substantially V shape. The movable blade frame  43  is fixed to the main frame  13 . 
     Further, as shown in  FIG. 2 , the cutter drive mechanism  45  of the movable blade unit  27  is provided by being supported by the side plate of the main frame  13 . The cutter drive mechanism  45  includes a cutter drive motor  47  and a gear train  48  for transmitting a driving force by the cutter drive motor  47  to the movable blade  41 . 
     Further, the cutter drive mechanism  45  includes, as shown in  FIGS. 8 and 9 , as transmission releasing means, the swing frame  49  capable of swinging the gear train  48  in directions of arrows d 1  and d 2  of  FIG. 8  with respect to a pinion  47   a  of the cutter drive motor  47 , and a swing frame biasing spring (not shown) for biasing the swing frame  49  so that the swing frame  49  swings in such direction of the arrow d 1  that the gear train  48  is spaced apart from the cutter drive motor  47 . 
     Further, the swing frame  49  is formed with an abutting portion  49   a  which is to be abutted on the position regulating surface  35   b  of the lock member  35 . The abutting portion  49   a  is abutted on the lock member  35 , thereby regulating a position of the gear train  48  with respect to the pinion  47   a  of the cutter drive motor  47 . 
     The main frame  13  for supporting the above-mentioned printing device  11  and the sheet cutting device  12  is formed with, as positioning means for positioning the stationary blade frame  33  with respect to the main frame  13 , as shown in  FIG. 5 , a support groove  13   a  for rotatably supporting the rotation shaft  22   a  of the platen roller  22 , the positioning protruding portion  13   b  engaged with the positioning groove  33   c  of the stationary blade frame  33  of the stationary blade unit  26 , and a lock groove  13   c  engaged with the lock arm  35   a  of the lock member  35 . 
     With regard to the sheet cutting device  12  included in the printer  1  structured as described above, an operation in which the stationary blade unit  26  is attached to and detached from the movable blade unit  27  side is described.  FIG. 4  is a see-through side view showing a state where the stationary blade unit  26  is positioned with respect to the main frame  13 .  FIG. 5  is a see-through side view showing a state where the stationary blade unit  26  is removed from the main frame  13 .  FIG. 6  is a see-through side view showing a state where regulation of a position of the stationary blade frame  33  by the lock member  35  is released.  FIG. 7  is a see-through side view showing a state where the stationary blade unit  26  is moved with respect to the main frame  13 .  FIG. 8  is a side view showing a state where the cutter drive motor  47  and the gear train  48  of the cutter drive mechanism  45  are engaged with each other.  FIG. 9  is a side view showing a state where the cutter drive motor  47  and the gear train  48  of the cutter drive mechanism  45  are disengaged with each other. 
     In the sheet cutting device  12 , with respect to the sheet material  5  supported over the blade edge of the stationary blade  31  and the guide surface  34   a  of the sheet guide  34 , the movable blade  41  is moved in the direction of the arrow c 1 , thereby allowing the sheet material  5  to be cut. However, due to unexpected paper jam, during cutting of the sheet material  5 , the movable blade  41  is disabled, and the sheet cutting device  12  comes to standstill in a state where the movable blade  41  and the stationary blade  31  are engaged with each other. 
     In this case, it is necessary that the sheet material  5  inhibiting the operation of the movable blade  41  be removed and the movable blade  41  be returned to the cutting stand-by position spaced apart from the stationary blade  31 . 
     First, in the sheet cutting device  12 , by rotating the release lever  36  in a direction of an arrow e of  FIG. 4 , the lock member  35  is rotated, the lock arm  35   a  of the lock member  35  is moved from the lock groove  33   a  of the stationary blade frame  33  and the lock groove  13   c  of the main frame  13 , and as shown in  FIG. 6 , the lock arm  35   a  of the lock member  35  is released from the lock grooves  13   c  and  33   a.    
     In a state where the lock arm  35   a  of the lock member  35  is detached from the lock groove  33   a  of the stationary blade frame  33 , the elongated hole  33   b  in the side plate of the stationary blade frame  33  becomes movable in the direction of the arrow a with respect to the rotation shaft  22   a  of the platen roller  22  supported by the main frame  13 . 
     When the stationary blade frame  33  becomes movable with respect to the main frame  13 , by a reaction force caused by the biasing force of the plate spring  32  which brings the stationary blade  31  into press contact with the movable blade  41 , as shown in  FIG. 7 , the stationary blade frame  33  is automatically moved in the direction of the arrow a with respect to the main frame  13 . The stationary blade frame  33  is moved with respect to the main frame  13 , thereby allowing the stationary blade  31  supported by the stationary blade frame  33  to be moved to the release position in which the stationary blade  31  is spaced apart from the movable blade  41  to release the press contact state therebetween. As described above, in the sheet cutting device  12 , with the position of the platen roller  22  on the printing device  11  side being retained, the stationary blade  31  is moved to the release position with respect to the movable blade  41 . 
     Further, by rotating the lock member  35 , together with the movement of the lock member  35 , the swing frame  49  whose position has been regulated by the position regulating surface  35   b  of the lock member  35  is swung by an elastic force of the swing frame biasing spring in the direction of the arrow d 1  as shown in  FIG. 9 . By swinging the swing frame  49  in the direction of the arrow d 1 , the pinion  47   a  of the cutter drive motor  47  and the gear train  48  are disengaged from each other, thereby disconnecting the cutter drive motor  47  and the movable blade  41  from each other. 
     Owing to the release of the press contact state between the movable blade  41  and the stationary blade  31  by spacing the stationary blade  31  away from the movable blade  41 , and the disconnection of the cutter drive motor  47  and the movable blade  41  from each other, the movable blade  41  becomes movable and is moved to the direction of the arrow c 2  by the biasing force of the movable blade biasing spring to be moved to the cutting stand-by position spaced apart from the stationary blade  31 . The movable blade  41  is moved to the stand-by position as described above, thereby making it possible to move the platen roller  22  to the direction of the arrow a without causing the platen roller  22  to impact on the movable blade  41 . 
     At last, as shown in  FIGS. 3 and 5 , the stationary blade unit  26  is moved to the direction of the arrow a, thereby being removed from the main frame  13 , and the platen roller  22  supported by the stationary blade frame  33  is spaced apart from the print head  21 . 
     Note that, according to the sheet cutting device  12  according to this embodiment, while as shown in  FIG. 5 , a separation structure is applied, in which the stationary blade unit  26  is removed by being separated from the main frame  13 , a structure in which the stationary blade unit  26  comes to standstill in the state shown in  FIG. 8 , that is, a so-called stationary structure, in which the stationary blade unit  26  is not separated from the main frame  13 , may be applied. 
     Next, in a case where the stationary blade unit  26  which has been removed from the main frame  13  is attached to the main frame  13 , an operation opposite to the above-mentioned operation is performed. First, when the stationary blade unit  26  is attached to the main frame  13 , the rotation shaft  22   a  of the platen roller  22  is supported by the support groove  13   a  of the main frame  13  and the positioning grooves  33   c  of the stationary blade frame  33  is engaged with the positioning protruding portion  13   b  of the main frame  13 . As a result, the stationary blade frame  33  is positioned in a predetermined position in a horizontal direction, that is, the direction indicated by the arrows c 1  and  2   c  to be attached to the main frame  13 . 
     Subsequently, when the stationary blade frame  33  is operated by being pushed in with respect to the main frame  13  against the biasing force of the plate spring  32 , the release lever  36  is rotated in the direction of the arrow f by the biasing force of the plate spring  32  to allow the lock arm  35   a  of the lock member  35  to be engaged with the lock groove  33   a  of the stationary blade frame  33  and the lock groove  13   c  of the main frame  13 . As a result, a state of the sheet cutting device  12  becomes a locking state where the stationary blade frame  33  is positioned in a predetermined position in a vertical direction, that is, the direction of the arrow a with respect to the main frame  13  and the position of the stationary blade frame  33  positioned with respect to the main frame  13  is regulated. 
     As described above, in the sheet cutting device  12  included in the printer  1 , in a case where the movable blade  41  is disabled during the cutting of the sheet material  5 , the stationary blade frame  33  supporting the stationary blade  31  is moved with respect to the main frame  13  while retaining the state where the print head  21  is brought into press contact with the platen roller  22 . As a result, the stationary blade  31  and the movable blade  41  are spaced apart from each other, the stationary blade  31  is moved to the release position in which the press contact state between the movable blade  41  and the stationary blade  31  is released, and the movable blade  41  and the cutter drive mechanism  45  are disconnected from each other. Consequently, the movable blade  41  can be easily moved to the cutting stand-by position spaced apart from the stationary blade  31  side, thereby smoothly removing the sheet material  5  from a periphery of the movable blade  41 . 
     Further, according to the sheet cutting device  12 , a moving direction of the stationary blade unit  26  is not limited. Accordingly, restriction on an opening and closing direction of a cover (not shown) covering the stationary blade unit  26  is eliminated. 
     Further, in the sheet cutting device  12 , by a reaction force caused by the biasing force of the plate spring  32  for bringing the stationary blade  31  into press contact with the movable blade  41 , the stationary blade frame  33  is moved with respect to the main frame  13 , thereby moving the stationary blade  31  to the release position. Accordingly, there is no need of separately providing a moving mechanism for moving the stationary blade  31 , whereby the structure is simplified. 
     In addition, in the related art sheet cutting device, in order to position the stationary blade in the predetermined position with respect to the movable blade, it is necessary that the stationary blade be pressed to the predetermined position by the cover or the like, for example, and it is necessary that the cover or the like be provided separately from the sheet cutting device. On the other hand, in the sheet cutting device  12  of this embodiment, the stationary blade frame  33  is positioned with respect to the main frame  13 , thereby positioning the stationary blade  31  in the predetermined position with respect to the movable blade  41 , so the sheet material  5  can be cut by the sheet cutting device  12  alone. 
     Briefly speaking, according to the sheet cutting device  12 , before moving the printing device  11 , the movable blade  41  is easily and reliably moved to the cutting stand-by position to increase a movable direction of the printing device  11 , to enable positioning of the stationary blade frame  33  with respect to the main frame  13 , and to enable cutting in a printer which does not require a retaining mechanism for the stationary blade frame  33 , including a separate member, whereby enlargement of application of the sheet cutting device and downsizing of the sheet cutting device as a whole can be achieved. 
     Further, in the sheet cutting device  12  according to the above embodiment, there is adopted the structure in which the stationary blade frame  33  is moved with respect to the main frame  13  to which the movable blade frame  43  is fixed. However, in contrast to this structure, there may be adopted a structure in which the movable blade frame  43  is moved with respect to the main frame  13  to which the stationary blade frame  33  is fixed, and the same effect is obtained. In a case of the structure in which the movable blade frame  43  is provided so as to be movable with respect to the main frame  13 , the movable blade  41  is disposed on a downstream side in a transporting direction of the sheet material  5  with respect to the stationary blade  31 . 
     Further, in the sheet cutting device of this embodiment, there is adopted the structure in which the platen roller is supported by the stationary blade frame, and as a matter of course, there may be adopted a structure in which the print head side is supported by the stationary blade frame. 
     Note that, the sheet cutting device according to the present invention is not limited to be applied to the separation structure in which the stationary blade frame is separated from the main frame as in the embodiment, and as a matter of course, the sheet cutting device may be applied to the stationary structure in which the stationary blade frame is not separated from the main frame. Even with the stationary structure, as in the case with the separation structure according to the above embodiment, the stationary blade can be easily moved to the release position. Accordingly, even in the case of taking any one of the separation structure and the stationary structure, in the sheet cutting device according to the present invention, the stationary blade and the stationary blade frame are structured in common with each other, thereby reducing manufacturing costs.