Patent Publication Number: US-2023150160-A1

Title: Cutter unit and printer

Description:
RELATED APPLICATIONS 
     This application claims priority to Japanese Patent Application No. 2021-185211, filed Nov. 12, 2021, the entire content of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a cutter unit and a printer. 
     2. Description of the Related Art 
     Hitherto, there have been proposed various types of tape printing apparatus including cutting means for cutting an elongated roll sheet over an entire width of the roll sheet. For example, there has been widely known a tape printing apparatus including cutting means for cutting a roll sheet over the entire width of the roll sheet by moving a movable blade in a reciprocating manner in a thickness direction of the roll sheet to slide the movable blade on a fixed blade. This tape printing apparatus can suitably cut the roll sheet through use of an urging member such as a presser bar spring for urging a sliding surface of the movable blade, which is to be slid on the fixed blade, to the fixed blade. For example, as the tape printing apparatus of this type, there has been known an apparatus including a pressing spring configured so as to allow the movable blade to freely reciprocate in a tape thickness direction under a state in which the movable blade is pressed to the fixed blade side. 
     However, in the movable blade of the tape printing apparatus described above, a surface (front surface) opposite to the sliding surface, which is slid on the fixed blade every time the movable blade is moved in a reciprocating manner, is slid on a part (recessed portion) of the fixed pressing spring, and hence a large sliding load is applied to the movable blade. Accordingly, there has been a problem in that a sliding portion of the movable blade is worn, which may result in shortening a lifetime of the movable blade or reducing durability of a cutting mechanism. Further, as a method of reducing the sliding load, a method of providing, for example, a lubricant or a sleeve between the pressing spring and the movable blade may be employed. However, there has been a problem in that such a method may complicate manufacturing steps, which may result in requiring more time and cost for manufacturing the tape printing apparatus. 
     Accordingly, in this technical field, there has been a demand for a cutter unit and a printer which are capable of cutting a recording sheet under a state in which a movable blade is pressed to a fixed blade side and reducing a sliding load on the movable blade. 
     SUMMARY OF THE INVENTION 
     According to one embodiment of the present invention, there is provided a cutter unit configured to cut a recording sheet to be advanced toward a forward side in an advancing direction, the cutter unit including: a fixed blade, which includes a fixed blade edge, and is provided on a first surface side of the recording sheet; a movable blade including: a movable blade edge opposed to the fixed blade edge in a cutting direction crossing the advancing direction; and a sliding surface, which is provided on a backward side in the advancing direction, and is configured to be slid on the fixed blade; and a rack holder capable of reciprocating along the cutting direction, the rack holder including: a movable blade holder configured to support the movable blade; and an urging member configured to urge the movable blade to the backward side in the advancing direction. 
     In the above-mentioned cutter unit according to the one embodiment of the present invention, wherein the urging member includes: a first end to be brought into abutment against the movable blade holder; and a second end to be brought into abutment against the forward side of the movable blade in the advancing direction. 
     In the above-mentioned cutter unit according to the one embodiment of the present invention, wherein the urging member is a pressurizing spring. 
     In the above-mentioned cutter unit according to the one embodiment of the present invention, wherein 
     In the above-mentioned cutter unit according to the one embodiment of the present invention, wherein the movable blade edge of the movable blade is formed into an inverted V shape extending from both ends toward a center portion of the movable blade edge. 
     In the above-mentioned cutter unit according to the one embodiment of the present invention, wherein the urging member is provided at a center portion of the movable blade. 
     In the above-mentioned cutter unit according to the one embodiment of the present invention, wherein the movable blade holder includes a plurality of grooves that are formed in a front end surface of the movable blade holder on the forward side, and each have an opening. 
     According to one embodiment of the present invention, there is provided a printer including: a recording sheet to be advanced toward a forward side in an advancing direction; and a cutter unit configured to cut the recording sheet, the cutter unit including: a fixed blade, which includes a fixed blade edge, and is provided on a first surface side of the recording sheet; a movable blade including: a movable blade edge opposed to the fixed blade edge in a cutting direction crossing the advancing direction; and a sliding surface, which is provided on a backward side in the advancing direction, and is configured to be slid on the fixed blade; and a rack holder capable of reciprocating along the cutting direction, the rack holder including: a movable blade holder configured to hold the movable blade; and an urging member configured to urge the movable blade to the backward side in the advancing direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a front view for illustrating a thermal printer according to one embodiment of the present invention. 
         FIG.  2    is a side view for illustrating the thermal printer. 
         FIG.  3    is a side view for illustrating an internal configuration of the thermal printer, and shows a cross section taken along the line I-I of  FIG.  1   . 
         FIG.  4    is a side view for illustrating a state in which a rack holder of the thermal printer includes a movable blade. 
         FIG.  5 A  is a side view for illustrating the movable blade, a fixed blade, and the rack holder of the thermal printer under a state in which the movable blade is moved away from the fixed blade toward a separation side in a cutting direction. 
         FIG.  5 B  is a perspective view for illustrating the state illustrated in  FIG.  5 A . 
         FIG.  5 C  is a perspective view for illustrating a state in which a sliding plate of the rack holder is removed. 
         FIG.  6 A  is a side view for illustrating the movable blade, the fixed blade, and the rack holder of the thermal printer under a state in which the movable blade performs cutting on a cutting side in the cutting direction. 
         FIG.  6 B  is a perspective view for illustrating the state illustrated in  FIG.  6 A . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     One embodiment of the present invention is described with reference to  FIG.  1    to  FIG.  6 B . In the following embodiment, description is made of, as an example, a thermal printer that is employed in, for example, a cash register or a portable terminal device and is capable of perform printing on, for example, various kinds of labels, receipts, and tickets. Further, in the embodiment and a modification example described later, in some cases, corresponding components are denoted by the same reference symbols, and description thereof is omitted. In addition, in the following description, an expression for describing relative or absolute arrangement, such as “parallel”, “orthogonal”, “center”, or “coaxial”, refers to not only the arrangement in a strict sense but also a state of being relatively displaced with an angle or distance to the degree that falls within a tolerance or can provide the same function. 
       FIG.  1    is a front view for illustrating a thermal printer  1 .  FIG.  2    is a side view for illustrating the thermal printer  1 .  FIG.  3    is a sectional view for illustrating an internal configuration of the thermal printer  1 , showing a cross section taken along the line I-I of  FIG.  1   . In the drawings, FR, RH, and UP represent a front side, a right side, and an upper side, respectively. As illustrated in  FIG.  3   , the thermal printer  1  includes a casing  2 , a printing unit  3 , a cutter unit  4 , and a recording sheet P. 
     As illustrated in  FIG.  1    to  FIG.  3   , the thermal printer  1  is a printer that performs printing on a print surface P 1  (front surface) of the recording sheet P by a thermal head  31  while conveying the recording sheet P through rotation of a platen roller  30 , which is to be described later, under a state in which the platen roller  30  and the thermal head  31  sandwich the recording sheet P therebetween. The thermal printer  1  is installed on an installation surface G. In the following description of the casing  2  and the printing unit  3 , a direction perpendicular to the installation surface G is referred to as an up-and-down direction (the upper side is indicated by the arrow UP), and two directions orthogonal to the up-and-down direction are referred to as a front-and-back direction (the front side is indicated by the arrow FR) and a right-and-left direction (the right side is indicated by the arrow RH). 
     As illustrated in  FIG.  3   , the recording sheet P is a recording sheet to be used for printing by the thermal printer  1 . The recording sheet P has the print surface P 1  (front surface) formed on a front surface thereof, and has a back surface P 2  formed on a side opposite to the print surface P 1  in the up-and-down direction. The recording sheet P is rolled up around a tubular core R 1  with the print surface P 1  facing the front side in the up-and-down direction, and thus forms a roll portion R. The roll portion R may have a configuration without the core R 1 . A leading edge portion PA of the recording sheet P is drawn to the front side, and is inserted between the thermal head  31  and the platen roller  30 . The roll portion R is located inside a housing  20  on a rear side opposite to the front side. When an upper cover  21  is in an opened position, the roll portion R is removed from or loaded into the housing  20  through an upper end opening portion  20   a  of the housing  20 . 
     The casing  2  is formed into a box shape. Specifically, the casing  2  includes the housing  20  and the upper cover  21 . 
     The housing  20  is formed into a box shape including the upper end opening portion  20   a  formed in an upper portion of the housing  20 , and is installed on the installation surface G. The housing  20  has a size large enough to allow the printing unit  3 , the cutter unit  4 , and the recording sheet P to be accommodated therein. 
     The upper cover  21  opens and closes the upper end opening portion  20   a  of the housing  20 . Specifically, the upper cover  21  is formed into a box shape opened downward, and has the same shape as that of the housing  20  in plan view. When the upper cover  21  is in a closed position, the upper cover  21  is superposed on the housing  20  from the upper side to close the upper end opening portion  20   a  of the housing  20 . Further, at this time, a delivery slot  23  is formed between the housing  20  and the upper cover  21 . The delivery slot  23  allows communication between an inside and an outside of the casing  2 , and has a slit shape extending in the right-and-left direction. The delivery slot  23  allows the recording sheet P having been subjected to printing by the printing unit  3  to be delivered toward the front side. Meanwhile, when the upper cover  21  is in the opened position, the upper cover  21  is retreated from the upper side of the housing  20  to open the upper end opening portion  20   a  of the housing  20 . 
     As illustrated in  FIG.  3   , the printing unit  3  includes the platen roller  30  and the thermal head  31 . 
     The platen roller  30  is a rubber roller extending in the right-and-left direction. The platen roller  30  is provided at a front end portion (portion closer to the delivery slot  23 ) inside the housing  20 . The platen roller  30  is rotatable about an axis O 1  extending along the right-and-left direction, and is rotated in accordance with a driving force of a driving motor (not shown) during conveyance of the recording sheet P. 
     The thermal head  31  is provided at a portion closer to the delivery slot  23  inside the upper cover  21 . The thermal head  31  includes a plurality of heating elements arrayed in line along the right-and-left direction. The thermal head  31  is fixed to a front end portion of the upper cover  21  with the heating elements facing downward. 
     The platen roller  30  and the thermal head  31  are opposed to each other in the up-and-down direction while sandwiching the recording sheet P therebetween. When the upper cover  21  is in the closed position, the thermal head  31  is held in close contact with the platen roller  30 . The recording sheet P is passed through between the platen roller  30  and the thermal head  31  in accordance with rotation of the platen roller  30 . Based on a signal output from a control board (not shown), a heating pattern of the heating elements of the thermal head  31  is controlled. Heat of the heating elements is transferred to the print surface P 1  of the recording sheet P, and thus information (such as letters or figures) corresponding to the heating pattern is printed on the print surface P 1 . 
       FIG.  4    is a side view for illustrating a state in which a rack holder  300  of the thermal printer  1  includes a movable blade  200 .  FIG.  5 A  is a side view for illustrating the movable blade  200 , a fixed blade  100 , and the rack holder  300  of the thermal printer  1  under a state in which the movable blade is moved away from the fixed blade toward a separation side B 1  in a cutting direction B.  FIG.  5 B  is a perspective view for illustrating the state illustrated in  FIG.  5 A . Further,  FIG.  5 C  is a perspective view for illustrating a state in which a sliding plate  314  of the rack holder  300  is removed.  FIG.  6 A  is a side view for illustrating the movable blade  200 , the fixed blade  100 , and the rack holder  300  of the thermal printer  1  under a state in which the movable blade performs cutting on a cutting side B 2  in the cutting direction B.  FIG.  6 B  is a perspective view for illustrating the state illustrated in  FIG.  6 A . As illustrated in  FIG.  3    to  FIGS.  6 A and  6 B , the cutter unit  4  includes the fixed blade  100 , the movable blade  200 , the rack holder  300 , and a moving mechanism  400 . 
     In the following description of the cutter unit  4 , a direction in which the recording sheet P is to be conveyed is referred to as a conveying direction A (advancing direction). In the conveying direction A, a side toward which the recording sheet P is to be conveyed is referred to as a conveyance destination side (forward side) A 1 , and a side opposite to the conveyance destination side A 1  is referred to as a conveyance source side (backward side) A 2 . Further, a direction of cutting the recording sheet P by the fixed blade  100  and the movable blade  200 , which is orthogonal to the conveying direction A, is referred to as the cutting direction B. In the cutting direction B, a side toward which the movable blade  200  is moved away from the fixed blade  100  is referred to as the separation side B 1 , and a side toward which the movable blade  200  is moved close to the fixed blade  100  to form a rift in the recording sheet P is referred to as the cutting side B 2 . In addition, a sheet width direction of the recording sheet P orthogonal to the conveying direction A and the cutting direction B is referred to as a width direction C. It is not always required that the cutting direction B be orthogonal to the conveying direction A, and it is only required that the cutting direction B match a direction of cutting the recording sheet P by the fixed blade  100  and the movable blade  200 . 
     In this embodiment, the conveying direction A substantially matches the front-and-back direction. The cutting direction B substantially matches the up-and-down direction. Further, the width direction C substantially matches the right-and-left direction. However, it is not always required that the conveying direction A match the front-and-back direction. It is not always required that the cutting direction B match the up-and-down direction. Further, it is not always required that the width direction C match the right-and-left direction. 
     As illustrated in  FIG.  3   ,  FIG.  5 A  to  FIG.  5 C ,  FIG.  6 A , and  FIG.  6 B , the fixed blade  100  is arranged between the platen roller  30  and the delivery slot  23  in the housing  20 . Further, a surface (first surface) of the recording sheet P on the fixed blade  100  side is the back surface P 2  of the recording sheet P. The fixed blade  100  is formed into a plate shape extending in the width direction C. The fixed blade  100  is fixed through predetermined means by a support portion (not shown) provided in the housing  20 . Further, the fixed blade  100  includes a fixed blade edge  110 . 
     The fixed blade edge  110  is a blade edge of the fixed blade  100  provided on the separation side B 1  in the cutting direction B. The fixed blade edge  110  of the fixed blade  100  is slightly moved to the conveyance destination side A 1  so that the fixed blade  100  is mounted in an inclined manner. 
     As illustrated in  FIG.  3    to  FIG.  6 B , the movable blade  200  is arranged between the thermal head  31  and the delivery slot  23  in the upper cover  21 . Further, a surface of the recording sheet P on the movable blade  200  side is the print surface P 1  of the recording sheet P. In addition, as illustrated in  FIG.  6 A  and  FIG.  6 B , the movable blade  200  is arranged more on the conveyance destination side A 1  than the fixed blade  100  in the conveying direction A when the movable blade  200  is slid on the fixed blade  100 . The movable blade  200  is formed into a plate shape extending in the width direction C. Further, the movable blade  200  is held by a movable blade holder  320  provided in the rack holder  300 . The movable blade  200  is moved in a reciprocating manner in the cutting direction B by the moving mechanism  400  through intermediation of the movable blade holder  320 . Accordingly, the movable blade  200  held by and integrated with the movable blade holder  320  is moved along with movement of the movable blade holder  320 . As illustrated in  FIG.  3    to  FIG.  6 B , the movable blade  200  includes a movable blade edge  210 , a movable blade sliding surface  211  (sliding surface), an urging member abutment surface  213 , and insertion holes  214 . 
     The movable blade edge  210  is a blade edge of the movable blade  200  that forms a rift in the recording sheet P. The movable blade edge  210  is provided on the cutting side B 2  of the movable blade  200  in the cutting direction B. 
     As illustrated in  FIG.  5 C  and  FIG.  6 B , the movable blade edge  210  of the movable blade  200  is formed into an inverted V shape extending to the separation side B 1  in the cutting direction B as extending from both ends toward a center of the movable blade edge  210  in the width direction C. A recessed portion  212  is formed in a center portion of the movable blade edge  210  of the movable blade  200  in the width direction C so as to be recessed to the separation side B 1  with respect to the movable blade edge  210 . 
     A bottom of the recessed portion  212  is configured so as to be prevented from being brought into contact with the recording sheet P when the cutter unit  4  cuts the recording sheet P. With this configuration, when the cutter unit  4  cuts the recording sheet P, an uncut portion is formed in a portion of the recording sheet P opposed to the recessed portion  212  (so-called partial cut). In this embodiment, description is made of a configuration in which one recessed portion  212  is formed, and thus one uncut portion is formed (one uncut portion is left), but the present invention is not limited to this configuration. For example, a plurality of recessed portions  212  may be formed, and thus a plurality of uncut portions may be formed (a plurality of uncut portions may be left). The recessed portion  212  is not an essential component. 
     The movable blade sliding surface  211  (sliding surface) is a surface of the movable blade  200  on the conveyance source side A 2 , and is slid on the fixed blade edge  110  of the fixed blade  100 . The movable blade  200  causes the movable blade sliding surface  211  to slide on the fixed blade edge  110 . With this configuration, the movable blade  200  cuts the recording sheet P between the movable blade edge  210  and the fixed blade edge  110 . The fixed blade  100  including the fixed blade edge  110  is provided in an inclined manner in the cutter unit  4 . Accordingly, the fixed blade edge  110  is reliably brought into abutment against the movable blade sliding surface  211  of the movable blade  200 , and thus the recording sheet P can be cut accurately. 
     The urging member abutment surface  213  is a surface of the movable blade  200  on the conveyance destination side A 1 . The urging member abutment surface  213  is formed on a side opposite to the movable blade sliding surface  211  in the conveying direction A. 
     As illustrated in  FIG.  5 C , the insertion holes  214  are holes formed so as to allow the movable blade  200  to be held on the movable blade holder  320 . Two insertion holes  214  pass through the movable blade  200 , and are formed in positions closer to both end sides of the movable blade  200  in the width direction C. Through the insertion holes  214 , holding protruding portions  324   p  are inserted when the movable blade  200  is arranged so as to be superposed on a rear holding portion  324  of a movable blade holder main body  321  to be described later from the conveyance destination side A 1  toward the conveyance source side A 2 . The insertion holes  214  are set to be slightly larger than the holding protruding portions  324   p.    
     As illustrated in  FIG.  3   , the rack holder  300  is arranged on the conveyance destination side A 1  of the housing  20  and on the side of the print surface P 1  of the recording sheet P. The rack holder  300  has a driving function of moving the movable blade  200  in a reciprocating manner for cutting the recording sheet P having been subjected to printing by the printing unit  3 , and a function of holding the movable blade  200 . The rack holder  300  includes a rack holder main body  310 , the movable blade holder  320 , and urging members  330 . 
     As illustrated in  FIG.  5 A  to  FIG.  5 C , or  FIG.  6 A  and  FIG.  6 B , the rack holder main body  310  includes a movable blade holder accommodating portion  311  and a moving mechanism mounting portion  312 . 
     The movable blade holder accommodating portion  311  is formed by both side walls  313 , the sliding plate  314  provided on the conveyance destination side A 1 , and an upper plate  315  provided on the conveyance source side A 2 . Further, the movable blade holder accommodating portion  311  defines a space S 1  by the both side walls  313 , the sliding plate  314 , and the upper plate  315 . 
     The both side walls  313  are provided at both ends of the movable blade holder accommodating portion  311  in the width direction C, respectively. The both side walls  313  each include a plurality of hook portions  313   a  on the conveyance destination side A 1 , and hence the both side walls  313  can be hooked on the housing  20 . With this configuration, the rack holder  300  can be mounted to the housing  20 . 
     The sliding plate  314  is provided on the conveyance destination side A 1  of the movable blade holder accommodating portion  311 . The sliding plate  314  includes a sliding surface  314   f  on the conveyance source side A 2 . The sliding surface  314   f  is slid on a front end surface  321   a  of the movable blade holder main body  321  when the movable blade holder  320  reciprocates along the cutting direction B. Further, the sliding plate  314  includes two guide holes  314   q . The two guide holes  314   q  are formed in center portions of the sliding surface  314   f  in line in the cutting direction B, and pass through the sliding plate  314 . The two guide holes  314   q  are formed so as to have a larger length in the cutting direction B than that in the width direction C. With the two guide holes  314   q , guide protruding portions  321   p  formed on the movable blade holder  320  are engaged. The guide holes  314   q  have a function of guiding the rack holder  300  so as to allow the rack holder  300  to move straight in the cutting direction B when the rack holder  300  is moved in a reciprocating manner in the cutting direction B. Further, through adjustment of the lengths of the guide holes  314   q  in the cutting direction B, movable ranges of the guide protruding portions  321   p  can be adjusted. Accordingly, the guide holes  314   q  can limit a movement range of the rack holder  300 . In addition, with the above-mentioned configuration, the guide holes  314   q  can eliminate a risk in that the movable blade  200  held in the rack holder  300  is moved beyond a reciprocating movable range. Further, an end portion of the sliding plate  314  on the cutting side B 2  is curved toward the conveyance source side A 2 , and thus a slight opening, that is, an opening portion  311   h  is formed in the movable blade holder accommodating portion  311 . The opening portion  311   h  is set to have a width slightly larger than a width of the movable blade  200  in the conveying direction A so as to allow the movable blade  200  to reciprocate in the cutting direction B. The movement range of the rack holder  300  may be controlled with a configuration in which, in addition to the guide holes  314   q , for example, a position sensor is provided in the movable blade holder accommodating portion  311 , and a movement position of the movable blade  200  is detected with the position sensor. 
     The upper plate  315  is provided on the separation side B 1  of the movable blade holder accommodating portion  311 . The upper plate  315  includes a lower surface  315   b  on the cutting side B 2 . 
     As illustrated in  FIG.  5 A  to  FIG.  5 C ,  FIG.  6 A , and  FIG.  6 B , the moving mechanism mounting portion  312  is a plate-like member to which the moving mechanism  400  can be mounted. The moving mechanism mounting portion  312  is provided on the lower surface  315   b  of the upper plate  315 . The moving mechanism mounting portion  312  extends along a horizontal plane defined by the conveying direction A and the cutting direction B. 
     As illustrated in  FIG.  5 C , the movable blade holder  320  is a holder that moves the movable blade  200  in a reciprocating manner in the cutting direction B while holding the movable blade  200 . The movable blade holder  320  includes the movable blade holder main body  321 , an urging member holding portion  322 , and a rack portion  323 . The movable blade holder  320  is accommodated in the space S 1  defined in the movable blade holder accommodating portion  311 . 
     The movable blade holder main body  321  is a holder that holds the movable blade  200 . The movable blade holder main body  321  includes the two guide protruding portions  321   p . The two guide protruding portions  321   p  are formed on the conveyance destination side A 1  of the movable blade holder main body  321  and on the front end surface  321   a , which is slid on the sliding plate  314 , and extend to the conveyance destination side A 1 . The guide protruding portions  321   p  are engaged with the guide holes  314   q  formed in the sliding plate  314 . The movable blade holder main body  321  causes the front end surface  321   a  to slide on the sliding surface  314   f  of the sliding plate  314 . In order to reduce a sliding load on the sliding plate  314 , a plurality of recessed portions  321   h  (grooves) each having an opening  321   q  are formed in the front end surface  321   a . Further, the movable blade holder main body  321  includes the rear holding portion  324  on a rear side thereof. 
     The rear holding portion  324  is a plate-like member provided on the conveyance source side A 2  of the movable blade holder main body  321  in the conveying direction A. The rear holding portion  324  overlaps the movable blade  200  provided on the conveyance destination side A 1 . The rear holding portion  324  has a function of holding the movable blade  200 . The rear holding portion  324  includes the two holding protruding portions  324   p . The two holding protruding portions  324   p  are formed on the conveyance destination side A 1  and on a surface that overlaps the movable blade  200 , and extend to the conveyance destination side A 1 . 
     As illustrated in  FIG.  5 C , the holding protruding portions  324   p  are set to be at substantially the same positions as those of the insertion holes  214  of the movable blade  200  in the width direction C. When the movable blade  200  is arranged from the conveyance destination side A 1 , the holding protruding portions  324   p  are inserted through the insertion holes  214  of the movable blade  200 . The holding protruding portions  324   p  slightly project from the insertion holes  214  to the conveyance destination side A 1 . With this configuration, the movable blade  200  is held on the movable blade holder main body  321 . Further, the holding protruding portions  324   p  are slightly smaller than the insertion holes  214  of the movable blade  200 . The holding protruding portions  324   p  are smaller than the insertion holes  214 , and thus can stably hold the movable blade  200  even in a case in which a position of the movable blade  200  is changed in the conveying direction A when the movable blade  200  is moved to the cutting side B 2  and brought into abutment against the fixed blade  100 . 
     The urging member holding portion  322  is provided on the conveyance destination side A 1  of the movable blade holder  320 . The urging member holding portion  322  is formed in a region from a lower end of the movable blade holder  320  to the cutting side B 2 , extends in the width direction C, and holds the urging members  330  to be described later. The urging member holding portion  322  includes a rear surface  322   b  on the conveyance source side A 2 . A first end  331  of each of the urging members  330  is brought into abutment against the rear surface  322   b . Further, the rear surface  322   b  includes urging member holding protruding portions  322   p  extending to the conveyance source side A 2 . The urging member holding protruding portions  322   p  are formed at positions against which the first ends  331  of the urging members  330  are to be brought into abutment. In accordance with the number of the urging members  330 , the urging member holding protruding portions  322   p  of the same number are provided. The urging member holding protruding portions  322   p  are each set to have substantially the same size as a diameter of an inner periphery of each of the urging members  330  (pressurizing spring), and allow the urging members  330  to be fitted thereto. Accordingly, the urging member holding protruding portions  322   p  allow the urging members  330  to be easily mounted thereto without the need for, for example, an adhesive. The number of the urging member holding protruding portions  322   p  is not particularly limited. Further, the first end  331  of each of the urging members  330  may be fixed directly to the rear surface  322   b  without provision of the urging member holding protruding portions  322   p , or the first end  331  may be fixed with, for example, an adhesive. 
     The rack portion  323  is provided on the conveyance source side A 2  of the movable blade holder  320 . The rack portion  323  meshes with a second driving gear  420  of the moving mechanism  400  to be described later. When a rotational driving force in one direction is transmitted to the rack portion  323 , the rack portion  323  is moved in a reciprocating manner in the cutting direction B. Along with movement of the rack portion  323 , as well as the movable blade holder  320 , the movable blade  200  and the urging members  330  are moved in a reciprocating manner. 
     As illustrated in  FIG.  4    to  FIG.  6 B , the moving mechanism  400  is driving means for moving the movable blade  200  in a reciprocating manner. The moving mechanism  400  is mounted to a predetermined position on one surface  312   c  of the moving mechanism mounting portion  312 . The moving mechanism  400  includes the driving motor (not shown), a first driving gear  410 , and the second driving gear  420 . 
     The driving motor gives the driving force to the first driving gear  410 . The driving force is transmitted to the first driving gear  410  by the driving motor, and thus the first driving gear  410  makes a rotary motion in a first rotation direction J 1  in which the first driving gear  410  rotates in one direction, or in a second rotation direction J 2  in which the first driving gear  410  rotates in a direction opposite to the first rotation direction J 1 . The second driving gear  420  is provided between the first driving gear  410  and the rack portion  323 . The second driving gear  420  meshes with the first driving gear  410  on the conveyance source side A 2 , and meshes with the rack portion  323  on the conveyance destination side A 1 . The rotational driving force is transmitted to the second driving gear  420  from the first driving gear  410 . When the first driving gear  410  rotates in the first rotation direction J 1 , the second driving gear  420  rotates in the second rotation direction J 2  opposite to the rotation direction of the first driving gear  410 . When the first driving gear  410  rotates in the second rotation direction J 2 , the second driving gear  420  rotates in the first rotation direction J 1  opposite to the rotation direction of the first driving gear  410 . When the second driving gear  420  rotates in the second rotation direction J 2 , the second driving gear  420  transmits the rotational driving force to the rack portion  323 , thereby moving the rack portion  323  to the cutting side B 2  in the cutting direction B. When the second driving gear  420  rotates in the first rotation direction J 1 , the second driving gear  420  transmits the rotational driving force to the rack portion  323 , thereby moving the rack portion  323  to the separation side B 1  in the cutting direction B. 
     With the above-mentioned configuration, the moving mechanism  400  moves the movable blade  200  in a reciprocating manner with respect to the recording sheet P through intermediation of the movable blade holder  320 , and causes the movable blade  200  and the fixed blade  100  to sandwich the recording sheet P therebetween, thereby forming a rift in the recording sheet P. In this embodiment, a movement range of the moving mechanism  400  is limited by the guide holes  314   q  and the guide protruding portions  321   p  described above. Accordingly, rotation ranges of the first driving gear  410  and the second driving gear  420  of the moving mechanism  400  are also limited. Owing to provision of the plurality of driving gears, the moving mechanism  400  can easily control an operation at the time of cutting, and can stabilize the cutting operation. 
     The urging members  330  always urge the movable blade  200  to the fixed blade  100 . As the urging members  330 , for example, pressurizing springs are used. In this embodiment, the urging members  330  include three pressurizing springs, and are arranged in the same line at substantially equal intervals in the width direction C. Further, the urging members  330  are arranged at such positions as to be prevented from overlapping the holding protruding portions  324   p  of the rear holding portion  324 . The urging members  330  always urge the movable blade  200  to the conveyance source side A 2  in the conveying direction A. Accordingly, the fixed blade edge  110  is reliably brought into abutment against the movable blade sliding surface  211  of the movable blade  200 , and thus the recording sheet P can be cut accurately. The urging members  330  each include the first end  331  and a second end  332  along the conveying direction A. 
     The first end  331  is fitted and coupled to the urging member holding protruding portion  322   p  that is formed on the rear surface  322   b  of the urging member holding portion  322  provided on the conveyance source side A 2  of the movable blade holder main body  321  and extends to the conveyance source side A 2 . 
     The second end  332  is brought into press contact with the urging member abutment surface  213  of the movable blade  200 . The urging members  330  are provided so as to always apply an urging force to the urging member abutment surface  213  of the movable blade  200  toward the conveyance source side A 2  in the conveying direction A, and thus the urging members  330  are prevented from slipping off the rack holder  300 . 
     The urging members  330  are provided so as to apply the urging force to the movable blade  200  arranged more on the conveyance source side A 2  than the urging members  330 . Regarding a position of each of the urging members  330 , it is desired that the urging member  330  be provided at a center of the movable blade  200  in the width direction C. With the arrangement at this position, each of the urging members  330  can reduce a risk in that a cutting failure occurs when the movable blade edge  210  of the movable blade  200  having an inverted V shape cuts the recording sheet P from both ends to a center of the recording sheet P. In this embodiment, three urging members  330  are used, but the number of the urging members  330  is not particularly limited. Further, it is not always required that the urging members  330  be the pressurizing springs, and it is only required that the urging members  330  always apply the urging force to the movable blade  200  toward the conveyance source side A 2 . Further, a material, a size, a shape, or the number of the urging members  330  is selected as appropriate in accordance with, for example, application and a configuration of the cutter unit  4 . 
     Next, operations of the cutter unit  4  of the above-mentioned thermal printer  1  are described with reference to  FIG.  5 A  to  FIG.  5 C ,  FIG.  6 A , and  FIG.  6 B . 
       FIG.  5 A  to  FIG.  5 C  are views for illustrating the movable blade  200 , the fixed blade  100 , and the rack holder  300  of the thermal printer  1  under a state in which the movable blade is moved away from the fixed blade toward the separation side B 1  in the cutting direction B.  FIG.  6 A  and  FIG.  6 B  are views for illustrating the movable blade  200 , the fixed blade  100 , and the rack holder  300  of the thermal printer  1  under a state in which the movable blade performs cutting on the cutting side B 2  in the cutting direction B. First, as illustrated in  FIG.  6 A  and  FIG.  6 B , the first driving gear  410  is rotated in the first rotation direction J 1  by the driving force transmitted from the driving motor (not shown). When the first driving gear  410  rotates in the first rotation direction J 1 , the second driving gear  420 , which is provided on the conveyance destination side A 1  and meshes with the first driving gear  410 , rotates in the second rotation direction J 2  opposite to the rotation direction of the first driving gear  410 . The rack portion  323  provided in the movable blade holder  320  meshes with the second driving gear  420 . When the second driving gear  420  rotates in the second rotation direction J 2 , the rotational driving force is transmitted to the rack portion  323 , and thus the rack portion  323  is moved to the cutting side B 2  in the cutting direction B. When the rack portion  323  is moved, the rack holder  300  is moved together with the rack portion  323 . The rack holder  300  holds the movable blade  200  through intermediation of the movable blade holder  320 , and hence moves the movable blade  200  to the cutting side B 2  in the cutting direction B. When the movable blade  200  is moved to the cutting side B 2  in the cutting direction B, the movable blade  200  can cut the recording sheet P between the movable blade edge  210  and the fixed blade edge  110 . The urging members  330  urge the movable blade  200 , and are moved to the cutting side B 2  in the cutting direction B along with movement of the rack holder  300 . Accordingly, the urging members  330  can always urge the movable blade  200  without being slid on the urging member abutment surface  213  of the movable blade  200 . 
     Next, as illustrated in  FIG.  5 A  to  FIG.  5 C , by the driving force transmitted from the driving motor (not shown), the first driving gear  410  is rotated in the second rotation direction J 2 . In this case, the second driving gear  420  rotates in the first rotation direction J 1  opposite to the rotation direction of the first driving gear  410 . The rack portion  323  provided in the movable blade holder  320  meshes with the second driving gear  420 . When the second driving gear  420  rotates in the first rotation direction J 1 , the rotational driving force is transmitted to the rack portion  323 , and the rack portion  323  is moved to the separation side B 1  in the cutting direction B. When the rack portion  323  is moved, the rack holder  300  is moved together with the rack portion  323 . The rack holder  300  holds the movable blade  200  through intermediation of the movable blade holder  320 . Accordingly, the movable blade  200  can be moved to the separation side B 1  in the cutting direction B. The urging members  330  urge the movable blade  200 , and are moved to the separation side B 1  in the cutting direction B along with movement of the rack holder  300 . Accordingly, the urging members  330  can always urge the movable blade  200  without being slid on the urging member abutment surface  213  of the movable blade  200 . 
     In this embodiment, the urging members  330  are provided in the rack holder  300 , and hence can always urge the movable blade  200 . Further, along with movement of the rack holder  300 , the movable blade  200  is moved in a reciprocating manner in the cutting direction B together with the urging members  330 . Accordingly, the movable blade  200  is not slid on the urging members  330 , thereby being capable of reducing the sliding load. Further, the movable blade  200  does not include a portion to be slid on the urging members  330 . With this configuration, the movable blade  200  can reduce a fear in that the movable blade  200  is worn due to sliding and generates, for example, abrasion powder. 
     Further, in this embodiment, the urging members  330  are each arranged at the center of the movable blade  200  in the width direction C. When each of the urging members  330  is arranged at this position, each of the urging members  330  can reduce a risk in that a cutting failure occurs when the movable blade edge  210  of the movable blade  200  having an inverted V shape cuts the recording sheet P from the both ends to the center of the recording sheet P. 
     Further, in this embodiment, the front end surface  321   a  of the movable blade holder main body  321  includes the plurality of recessed portions  321   h  each having the opening  321   q . Accordingly, when the movable blade holder main body  321  is slid on the sliding plate  314 , sliding portions can be reduced. 
     Further, in this embodiment, the guide holes  314   q  of the rack holder  300  have a function of guiding the rack holder  300  so as to allow the rack holder  300  to move straight in the cutting direction B when the rack holder  300  is moved in a reciprocating manner in the cutting direction B. Further, through adjustment of the lengths of the guide holes  314   q  in the cutting direction B, the movable ranges of the guide protruding portions  321   p  can be adjusted. Accordingly, the guide holes  314   q  can limit the movement range of the rack holder  300 . In addition, with the above-mentioned configuration, the guide holes  314   q  can reduce a fear in that the movable blade  200  held in the rack holder  300  is moved beyond the reciprocating movable range. 
     As described above, in the thermal printer  1  and the cutter unit  4  according to this embodiment, the movable blade  200  can cut the recording sheet P under a state of being pressed toward the fixed blade  100  side, thereby being capable of reducing the sliding load on the movable blade  200 . 
     The present invention is not limited by the one embodiment described above. Further, the components in the one embodiment encompass components easily conceived by a person skilled in the art, or substantially the same components, that is, so-called equivalents. In addition, the components disclosed in the one embodiment can be combined with each other as appropriate. 
     Hereinabove, the one embodiment of the present invention has been described in detail with reference to the accompanying drawings. However, specific structures of the present invention are not limited to the one embodiment and encompass design modifications and the like without departing from the gist of the present invention. Further, the components described in the one embodiment described above and a modification example described below may be configured in combination with each other as appropriate. 
     For example, the printer according to the present invention is not limited to the thermal printer  1  illustrated in  FIG.  1   , and is also applicable to printers having a variety of configurations. 
     Further, in the above-mentioned embodiment, the fixed blade  100  and the movable blade  200  are arranged under a state in which the first surface being the surface on the fixed blade  100  side is the back surface P 2 , and the surface on the movable blade  200  side is the print surface P 1 . However, in the present invention, the arrangement is not particularly limited to such arrangement. For example, the fixed blade  100  and the movable blade  200  may be arranged under a state in which the first surface being the surface on the fixed blade  100  side is the print surface P 1 , and the surface on the movable blade  200  side is the back surface P 2 . 
     Further, in the above-mentioned embodiment, the movable blade  200  is arranged more on the conveyance destination side A 1  in the conveying direction A than the fixed blade  100  when being slid on the fixed blade  100 . However, in the movable blade of the present invention, for example, a part of the movable blade edge  210  may be arranged more on the conveyance source side A 2  than the fixed blade  100 . 
     Further, for example, the urging member  330  that urges the movable blade  200  in the cutting direction B may be formed of an urging member other than the pressurizing spring (for example, a synthetic rubber or a plate spring). In addition, it is not always required that the urging member  330  urge the movable blade  200  to the fixed blade  100  in the conveying direction A. For example, the urging member  330  may be arranged more on the conveyance source side A 2  than the movable blade  200 , and may be configured to always urge the movable blade  200  to the fixed blade  100  by pulling the movable blade  200 . 
     Further, in the above-mentioned embodiment, description is made of the thermal printer  1  of a so-called cross type in which the movable blade  200  crosses the fixed blade  100 , but the present invention is not limited thereto. The present invention is also applicable to printers having a variety of configurations in which the movable blade  200  is moved in a reciprocating manner to cut the recording sheet P. 
     In any mode described above, according to the cutter unit and the printer of the present invention, the movable blade can cut the recording sheet under a state of being pressed toward the fixed blade side, thereby being capable of reducing the sliding load on the movable blade.