Patent Publication Number: US-2022212485-A1

Title: Printer and printing cassette

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This is a continuation application of International Application No. PCT/JP2020/034877 filed on Sep. 15, 2020 which claims priority from Japanese Patent Application No. 2019-178163 filed on Sep. 30, 2019. The entire contents of the earlier applications are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     Aspects of the disclosure relate to a printer and a printing cassette. 
     BACKGROUND 
     In a printer that performs printing on a printing tape, replacement and resupply of a printing tape is performed by attachment and detachment of a cassette accommodating a printing tape to and from the printer (see Patent Literature 1). 
     SUMMARY 
     In the above-described printer, a platen roller may convey the printing tape in the cassette toward the outside of the cassette. The platen roller may be rotationally driven by a driving source such as a motor. 
     However, if the platen roller rotates when the cassette is not installed in the printer, an unexpected problem may occur. For example, if the platen roller rotates during installation of the cassette, the printing tape may be jammed. 
     Accordingly, aspects of the disclosure provide a printer and a printing cassette in which an unexpected rotation of a platen roller may be reduced. 
     In one or more aspects of the disclosure, a printer may include: a print head; a platen roller facing the print head; a driving source; a drive shaft connected to be driven to the driving source and is rotatable about a rotation axis thereof; a platen gear connected to be driven to the platen roller; and a cassette mounting portion at which the print head and the drive shaft are disposed. 
     A printing cassette including a to-be-printed tape, an input unit, and an output unit connected to be driven to the input unit may be mountable on the cassette mounting portion in an axial direction of the rotation axis of the drive shaft. In a state where the printing cassette is mounted on the cassette mounting portion, the drive shaft may be engaged with the input unit and the platen gear is engaged with the output unit. 
     In one or more aspects of the disclosure, a printing cassette mountable on a printer may include a print head, a platen roller facing the print head, a driving source, a drive shaft connected to be driven to the driving source and rotatable about a rotation axis thereof, a platen gear connected to be driven to the platen roller, and a cassette mounting portion at which the print head and the driving shaft are disposed, in an axial direction of the rotation axis of the drive shaft. 
     The printing cassette may include a to-be-printed tape, an input unit, and an output unit. In a state where the printing cassette is mounted on the cassette mounting portion, the input unit may be engaged with the drive shaft and the output unit is engaged with the platen gear. 
     According to these configurations, a driving force from the driving source of the printer may be transmitted to the platen roller via the input unit and the output unit in the printing cassette. That is, the driving force may be transmitted to the platen roller only when the printing cassette is mounted on the printer. Therefore, an unexpected rotation of the platen roller may be reduced in a state where the printing cassette is not mounted. 
     In one or more aspects of the disclosure, a printing cassette may include: a case; a to-be-printed tape, at least a portion of which is accommodated in the case; a first gear including a first internal gear and a first external gear; a transmission gear or a transmission gear train engaging with the first external gear; and a second gear including a second external gear engaging with the transmission gear or the transmission gear train. An entirety of the first internal gear may be accommodated in the case. A portion of the second external gear may be located outside the case. 
     According to these configurations, a driving force from the driving source of the printer may be transmitted to the platen roller via the first gear, the transmission gear or the transmission gear train, and the second gear in the printing cassette. That is, the driving force may be transmitted to the platen roller only when the printing cassette is mounted on the printer. Therefore, an unexpected rotation of the platen roller may be reduced in a state where the printing cassette is not mounted. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A, 1B, and 1C  are schematic perspective views each illustrating a state in which a printing cassette is detached from a printer in a printing system er according to an illustrative embodiment. 
         FIGS. 2A, 2B, and 2C  are schematic perspective views each illustrating the printing cassette in the printing system of  FIG. 1A . 
         FIG. 3  is a disassembled schematic perspective view of the printing cassette of  FIG. 2A . 
         FIG. 4  is a schematic perspective view of a clutch in the printing cassette of  FIG. 3A . 
         FIG. 5A  is a schematic cross-sectional view taken along line V-V of  FIG. 2A . 
         FIG. 5B  is a partial enlarged view of  FIG. 5A . 
         FIG. 6  is a schematic perspective view illustrating a state in which a first cover portion of the printing cassette of  FIG. 2A  is removed. 
         FIG. 7  is a perspective view for explaining a path of a to-be-printed tape and a path of an ink ribbon in the printing cassette of  FIG. 2A . 
         FIG. 8A  is a schematic cross-sectional view taken along line VIIIA-VIIIA of FIG.  2 C 
         FIG. 8B  is a schematic cross-sectional view taken along line VIIIB-VIIIB of  FIG. 2C . 
         FIG. 8C  is a schematic cross-sectional view taken along line VIIIC-VIIIC of  FIG. 2C . 
         FIG. 8D  is a schematic cross-sectional view taken along line VIIID-VIIID of  FIG. 2C . 
         FIG. 9  is a schematic plan view illustrating the printer in the printing system of  FIG. 1A . 
         FIG. 10A  is a schematic view illustrating a separated state in which an output gear and a platen gear are separated in the printing system of  FIG. 1A . 
         FIG. 10B  is a schematic view illustrating an engaged state in which the output gear and the platen gear are engaged in the printing system of  FIG. 1A . 
         FIGS. 11A and 11B  are schematic perspective views each illustrating a state in which a printing cassette is detached from a printer in a printing system er according to an illustrative embodiment different from the illustrative embodiment illustrated in  FIG. 1A . 
         FIG. 12  is a disassembled schematic perspective view of the printing cassette in the printing system of  FIG. 11A . 
         FIG. 13A  is a schematic cross-sectional view taken along line XIIIA-XIIIA of  FIG. 11B . 
         FIG. 13B  is a partial enlarged view of  FIG. 13A . 
         FIG. 14  is a schematic plan view illustrating the printer in the printing system of  FIG. 11A . 
         FIG. 15A  is a schematic view illustrating a separated state in which an output gear and a platen gear are separated in the printing system of  FIG. 11A . 
         FIG. 15B  is a schematic view illustrating an engaged state in which the output gear and the platen gear are engaged in the printing system of  FIG. 11A . 
         FIG. 16  is a disassembled schematic perspective view of a printing cassette for a printing system according to an illustrative embodiment different from the illustrative embodiments illustrated in  FIGS. 1A and 11A . 
         FIG. 17  is a disassembled schematic perspective view of a printing cassette for a printing system according to an illustrative embodiment different from the illustrative embodiments illustrated in  FIGS. 1A, 11A, and 16 . 
         FIG. 18  is a disassembled schematic perspective view of a printing cassette for a printing system according to an illustrative embodiment different from the illustrative embodiments illustrated in  FIGS. 1A, 11A, 16, and 17 . 
     
    
    
     DETAILED DESCRIPTION 
     First Illustrative Embodiment 
     1-1. Configuration 
     A printing system  1  illustrated in  FIGS. 1A, 1B, and 1C  includes a printing cassette  10  and a printer  100 . The printing system  1  may be a device that performs printing on a tape-shaped printing medium. 
     In the illustrative embodiment, an axial direction of an output gear  18  is defined as an up-down direction. A direction that is perpendicular to the up-down direction and in which the output gear  18  and an input spool  16  are arranged next to each other is defined as a front-rear direction. A direction perpendicular to both the up-down direction and the front-rear direction is defined as a left-right direction. 
     &lt;Printing Cassette&gt; 
     The printing cassette  10  accommodates a printing medium. The printing cassette  10  is mountable on and removable from the printer  100 . Replacing the printing cassette  10  may achieve resupply of a printing medium and change of a type (e.g., color, material, or others) of the printing medium. 
     As illustrated in  FIGS. 2A, 2B, and 2C , the printing cassette  10  includes a case  35  that accommodates a to-be-printed tape, an ink ribbon, and others. An outer shape of the printing cassette  10  (i.e., a shape of the case  35 ) is a rectangular parallelepiped having sides parallel to the up-down direction, sides parallel to the front-rear direction, and sides parallel to the left-right direction. 
     The case  35  is configured to be mounted facing downward with respect to the printer  100 . The case  35  includes a first cover portion  31 , a first case portion  32 , a second case portion  33 , and a second cover portion  34 . 
     As illustrated in  FIG. 3 , the printing cassette  10  includes a to-be-printed tape roll  11 , a first feed spool  12 , a spacer film  13 A, a spacer film  13 B, an ink ribbon roll  14 , a second feed spool  15 , an input spool  16  (an example of a rotating spool), a clutch  17 , the output gear  18 , the input gear  19 , and an idle gear  20 . 
     (To-be-Printed Tape Roll) 
     In the to-be-printed tape roll  11 , a to-be-printed tape on which printing is to be performed is wound around the first feed spool  12 . Printing is performed on a surface of the to-be-printed tape by a print head  102  of the printer  100  and an ink ribbon. 
     Two spacer films  13 A,  13 B are disposed outside the to-be-printed tape roll  11  in the up-down direction such that the spacer films  13 A.  13 B sandwich the to-be-printed tape roll  11  therebetween. The spacer film  13 A is disposed between the to-be-printed tape roll  11  and the first cover portion  31 . The spacer film  13 B is disposed between the to-be-printed tape roll  11  and the first case portion  32 . 
     (First Feed Spool) 
     The first feed spool  12  is rotatable about its rotation axis. The first feed spool  12  rotates along with conveyance of the to-be-printed tape by a platen roller  103  of the printer  100 , thereby feeding the to-be-printed tape to the print head  102 . 
     (Ink Ribbon Roll) 
     In the ink ribbon roll  14 , the ink ribbon used for printing on the to-be-printed tape is wound around the second feed spool  15 . 
     In a head opening  33 B, the ink ribbon is laid on the to-be-printed tape and used for printing performed by the print head  102  therein. The ink ribbon that has been used for printing is taken up by the input spool  16 . 
     (Second Feed Spool) 
     The second feed spool  15  is rotatable about its rotation axis. The rotation axis of the second feed spool  15  is parallel to the rotational axis of the first feed spool  12 , that is, parallel to the up-down direction. The second feed spool  15  rotates in a first rotation direction to feed the ink ribbon from the ink ribbon roll  14 . 
     The second feed spool  15  rotates along with take-up of the ink ribbon by the input spool  16 , thereby feeding the ink ribbon to the print head  102 . Further, the second feed spool  15  is disposed such that a portion thereof overlaps the to-be-printed tape roll  11  in the up-down direction. 
     (Input Spool) 
     The input spool  16  is rotatable about its rotation axis. The rotation axis of the input spool  16  is parallel to the rotation axis of the second feed spool  15 . 
     The input spool  16  has a cylindrical shape and has a hollow portion defined by an inner peripheral surface  16 A. Spline teeth  16 B are provided on the inner peripheral surface  16 A of the input spool  16 . That is, the input spool  16  may be an internal gear. A drive shaft  105  of the printer  100  is to be coupled to the spline teeth  16 B. The input spool  16  is rotated by the drive shaft  105  to take up the ink ribbon. 
     (Clutch) 
     As illustrated in  FIG. 4 , the clutch  17  includes a spring holder  71  and a clutch spring  72 . The spring holder  71  is rotatable about its rotation axis. 
     The spring holder  71  includes a first cylindrical portion  71 A, a second cylindrical portion  71 B, and a projection  71 C. The second cylindrical portion  71 B has an outside diameter smaller than the first cylindrical portion  71 A. A central axis of the second cylindrical portion  71 B is coaxial with a center axis of the first cylindrical portion  71 A. The projection  71 C protrudes outward in a radial direction of the first cylindrical portion  71 A from an outer peripheral surface of the first cylindrical portion  71 A. 
     The clutch spring  72  includes a coil portion  72 A, a first engagement portion  72 B, and a second engagement portion  72 C. The coil portion  72 A includes a wire material that is wound around the outer peripheral surface of the second cylindrical portion  71 B in a spiral fashion. Each of the first engagement portion  72 B and the second engagement portion  72 C is a protruding end portion of the wire material of the coil portion  72 A protruding outward in the radial direction of the second cylindrical portion  71 B. 
     As illustrated in  FIGS. 5A and 5B , the clutch  17  is disposed in a hollow portion of the second feed spool  15 . A rotation axis of the clutch  17  is coaxial with the rotation axis of the second feed spool  15 . 
     The second cylindrical portion  71 B of the spring holder  71  and the coil portion  72 A of the clutch spring  72  are disposed inside a plurality of projecting portions  33 F of the second case portion  33 . The first engagement portion  72 B and the second engagement portion  72 C of the clutch spring  72  are engaged with the projecting portions  33 F. 
     The projection  71 C (refer to  FIG. 4 ) of the spring holder  71  is engaged with a groove defined in an inner peripheral surface of the second feed spool  15 . Thus, the spring holder  71  rotates together with the second feed spool  15  about the rotation axis of the second feed spool  15 . 
     Resistance is applied to rotation of the second feed spool  15  by sliding friction between the second cylindrical portion  71 B of the spring holder  71  and the coil portion  72 A of the clutch spring  72 . That is, the clutch  17  applies rotational resistance to the ink ribbon roll  14 . A torque for feeding (i.e., taking up) the ink ribbon may be set by the rotational resistance of the clutch  17 . 
     The coil portion  72 A of the clutch spring  72  is wound around the spring holder  71  such that a diameter of the coil portion  72 A increases when the spring holder  71  rotates in the first rotation direction and decreases when the spring holder  71  rotates in a second rotation direction opposite to the first rotation direction. 
     When the second feed spool  15  rotates in the first rotation direction due to drawing of the ink ribbon, the diameter of the coil portion  72 A increases, and therefore, sliding friction between the coil portion  72 A and the second cylindrical portion  71 B decreases. As a result, the rotation resistance of the second feed spool  15  is reduced. 
     On the other hand, when the rotation of the second feed spool  15  decreases, the diameter of the coil portion  72 A decreases, and thus the rotational resistance of the second feed spool  15  increases. When the rotation of the second feed spool  15  is stopped, the sliding friction between the coil portion  72 A and the second cylindrical portion  71 B returns to an initial state. 
     (Output Gear) 
     The output gear  18  illustrated in  FIG. 3  may be an output unit for outputting, to the outside, a driving force for conveying the to-be-printed tape. The output gear  18  is connected to be driven to the input gear  19 . The output gear  18  transmits a driving force to the platen roller  103  via a platen gear  104  of the printer  100 . 
     The output gear  18  may be an external gear including a disk that rotates about its rotation axis and teeth on a surface of the disk extending parallel to the up-down direction. One (i.e., an upper surface) of surfaces of the disk of the output gear  18  extending perpendicular to the up-down direction faces a cover portion  32 B of the case  35  in the up-down direction. A portion of the other (i.e., a lower surface) of the surfaces of the disk extending perpendicular to the up-down direction does not face the case  35  in the up-down direction. 
     The output gear  18  is partially exposed to the head opening  33 B, and thus, the exposed portion thereof is located outside the case  35 . The output gear  18  is in engagement with the platen gear  104  at the head opening  33 B in a state where the printing cassette  10  is mounted on a cassette mounting portion  101  of the printer  100 . 
     The to-be-printed tape roll  11 , the output gear  18 , and the ink ribbon roll  14  (i.e., the second feed spool  15 ) are disposed in the order of the to-be-printed tape roll  11 , the output gear  18 , and the ink ribbon roll  14  in the up-down direction. That is, the output gear  18  is positioned between the to-be-printed tape roll  11  and the ink ribbon roll  14  in the up-down direction. 
     (Input Gear) 
     As illustrated in  FIG. 3 , the input gear  19  may be an input unit that is indirectly connected to the output gear  18  via an idle gear  20  and transmits a driving force to the output gear  18 . 
     The input gear  19  engages the drive shaft  105  in a state where the printing cassette  10  is mounted on the cassette mounting portion  101  of the printer  100 . A driving force from a driving source of the printer  100  is input to the input gear  19  via the drive shaft  105 . 
     The input gear  19  has an external gear  19 A and a cylindrical internal gear  19 B. The entire external gear  19 A and the entire internal gear  19 B are accommodated in the case  35 . In other words, the entire input gear  19  is accommodated in the case  35 . 
     The external gear  19 A rotates integrally with the internal gear  19 B by the driving force input to the internal gear  19 B. The internal gear  19 B is fixed to a lower surface of the external gear  19 A and has spline teeth on an inner peripheral surface thereof. 
     A rotation axis of the input gear  19  (i.e., a rotation axis of the external gear  19 A and a rotation axis of the internal gear  19 B) is coaxial with the rotation axis of the input spool  16 . The input spool  16 , the input gear  19 , and the to-be-printed tape roll  11  are disposed in the order of the input spool  16 , the input gear  19 , and the to-be-printed tape roll  11  in the up-down direction. 
     That is, the input gear  19  is positioned between the input spool  16  and the to-be-printed tape roll  11  in the up-down direction. Further, the input gear  19  is disposed such that a portion thereof overlaps the to-be-printed tape roll  11  in the up-down direction. 
     The rotation axis of the input gear  19  extends in the hollow portion of the input spool  16 . That is, the drive shaft  105  is inserted into the input spool  16  and the input gear  19  simultaneously. As a result, although the input gear  19  is not directly coupled to the input spool  16 , the input gear  19  is rotated by a driving source (i.e., the drive shaft  105 ) common to the input spool  16 . 
     (Idle Gear) 
     The idle gear  20  is a transmission gear that is connected to be driven to (i.e., is in engagement with) the input gear  19  and the output gear  18  and transmits the driving force input to the input gear  19  to the output gear  18 . 
     The idle gear  20  is a stepped gear in which a first gear  20 A engaged with the input gear  19  and a second gear  20 B engaged with the output gear  18  are arranged coaxially. The second gear  20 B has a diameter smaller than the first gear  20 A. 
     The second gear  20 B is disposed at a position closer to the to-be-printed tape roll  11  than the second gear  20 B to the first gear  20 A in the up-down direction (i.e., on an upper side). The idle gear  20  constitutes a deceleration mechanism that decelerates the driving force input to the input gear  19 . 
     (Case) 
     The first cover portion  31  serves as an upper end portion of the printing cassette  10 . The first case portion  32  is disposed below the first cover portion  31  and is connected to the first cover portion  31  in the up-down direction. The second case portion  33  is disposed below the first case portion  32  and is connected to the first case portion  32  in the up-down direction. The second cover portion  34  serves as a lower end portion of the printing cassette  10 . The second cover portion  34  is connected to the second case portion  33  in the up-down direction. 
     The first cover portion  31  and the first case portion  32  accommodate the to-be-printed tape roll  11 . That is, the to-be-printed tape roll  11  is disposed in a space surrounded by the first cover portion  31  and the first case portion  32 . 
     The second cover portion  34  and the second case portion  33  accommodate the ink ribbon roll  14 , the second feed spool  15 , and the input spool  16 . That is, the ink ribbon roll  14 , the second feed spool  15 , and the input spool  16  are disposed in a space surrounded by the second cover portion  34  and the second case portion  33 . 
     The first case portion  32  and the second case portion  33  are connected to each other. A portion of the output gear  18 , the input gear  19 , and the idle gear  20  are disposed in a space surrounded by the first case portion  32  and the second case portion  33 . 
     The first case portion  32  includes a first sidewall  32 A, a cover portion  32 B, a first guide  32 C, a first shaft portion  32 D, a second shaft portion  32 E, a third shaft portion  32 F, and an inner wall  32 G. The first sidewall  32 A defines side surfaces of the printing cassette  10 . The side surfaces of the printing cassette  10  extend parallel to the up-down direction. 
     The cover portion  32 B has surfaces perpendicular to the up-down direction. The cover portion  32 B is disposed at a position where the cover portion  32 B overlaps the output gear  18  in the up-down direction. In the illustrative embodiment, the cover portion  32 B is contiguous with a lower end portion of the first sidewall  32 A, and is disposed at a right front corner of the first case portion  32 . 
     The output gear  18 , the cover portion  32 B, and the to-be-printed tape roll  11  are arranged next to each other in the order of the output gear  18 , the cover portion  32 B, and the to-be-printed tape roll  11  in the up-down direction. As described above, an upper surface of the output gear  18  is entirely covered by the cover portion  32 B. 
     As illustrated in  FIG. 6 , the first guide  32 C is a portion around which the to-be-printed tape  11 A drawn from the to-be-printed tape roll  11  is wound. The first guide  32 C has a plurality of ribs being plates that are apart from each other in a circumferential direction of the to-be-printed tape roll  11 . The plurality of ribs protrude in a radial direction of the to-be-printed tape roll  11 , and a protruding amount of each of the plurality of ribs (i.e., a plate width) increases as each of the plurality of ribs extends downward. 
     The first shaft portion  32 D illustrated in  FIG. 3  supports the output gear  18  such that the output gear  18  is rotatable about its rotation axis parallel to the up-down direction. The second shaft portion  32 E supports the input gear  19  such that the input gear  19  rotates about its rotation axis parallel to the up-down direction. The third shaft portion  32 F supports the idle gear  20  such that the idle gear  20  rotates about its rotation axis parallel to the up-down direction. The first shaft portion  32 D, the second shaft portion  32 E, and the third shaft portion  32 F protrude from the inner wall  32 G. 
     The second case portion  33  includes a second sidewall  33 A, the head opening  33 B, an outlet  33 C, a second guide  33 D, a protruding portion  33 E, and the plurality of projecting portions  33 F. The second sidewall  33 A defines side surfaces of the printing cassette  10 . The side surfaces of the printing cassette  10  extend parallel to the up-down direction. 
     The head opening  33 B is a cutaway portion of the second sidewall  33 A. The head opening  33 B is a space in which the print head  102  is located by insertion into the head opening  33 B from below in a state where the printing cassette  10  is mounted to the printer  100 . The head opening  33 B opens downward in the printing cassette  10 . 
     The second guide  33 D is a portion around which a to-be-printed tape  11 A that has passed the first guide  32 C. As with the first guide  32 C, the second guide  33 D has a plurality of ribs being plates that are apart from each other in a circumferential direction of the ink ribbon roll  14 . The plurality of ribs protrude in a radial direction of the ink ribbon roll  14 , and a protruding amount of each of the plurality of ribs (i.e., a plate width) decreases as each of the plurality of ribs extends downward. 
     The protruding portion  33 E is disposed at a position where the protruding portion  33 E overlaps the output gear  18  in the up-down direction. The protruding portion  33 E is disposed below the output gear  18  (i.e., on the side opposite to the cover portion  32 B across the output gear  18 ). 
     The print head  102  of the printer  100  is inserted into an area below the protruding portion  33 E. Thus, in a state where the printing cassette  10  is mounted on the cassette mounting portion  101  of the printer  100 , the output gear  18  is disposed upstream from (i.e., upper side of) the print head  102  in a mounting direction of the printing cassette  10  onto the cassette mounting portion  101 . 
     As illustrated in the  FIG. 5A , the plurality of projecting portions  33 F are disposed along a circumferential direction of the second cylindrical portion  71 B of the clutch  17  to surround the second cylindrical portion  71 B and the coil portion  72 A of the clutch  17 . The first engagement portion  72 B and the second engagement portion  72 C of the clutch spring  72  are inserted between the projecting portions  33 F. 
     A fourth shaft portion  34 A provided at the second cover portion  34  is inserted into the first cylindrical portion  71 A of the clutch  17 . The second feed spool  15  is rotatably supported by the fourth shaft portion  34 A via the first cylindrical portion  71 A. 
     As illustrated in  FIG. 7 , the to-be-printed tape  11 A and the ink ribbon  14 A extend across the head opening  33 B in the right-left direction. The to-be-printed tape  11 A on which printing has been performed is discharged to the outside of the printing system  1  from the outlet  33 C. 
     As illustrated in  FIGS. 8A, 8B, 8C, and 8D , the first guide  32 C and the second guide  33 D define a path through which the to-be-printed tape  11 A constituting the to-be-printed tape roll  11  is fed from the first case portion  32  to the second case portion  33 . 
     Specifically, as illustrated in  FIG. 8A , the to-be-printed tape  11 A drawn from the to-be-printed tape roll  11  is conveyed in a spiral manner toward the lower rear in the first case portion  32  while contacting the first guide  32 C from an outer side in the radial direction of the to-be-printed tape roll  11 . As illustrated in  FIG. 8B , the to-be-printed tape  11 A is further conveyed toward the lower left while extending across a connected portion of the first case portion  32  and the second case portion  33  in the up-down direction. 
     As illustrated in  FIG. 8C , the to-be-printed tape  11 A that has reached the second case portion  33  is conveyed toward the lower front with contacting the second guide  33 D from the outer side in the radial direction. As illustrated in  FIG. 8D , the to-be-printed tape  11 A that has reached the lower end portion of the printing cassette  10  passes the head opening  33 B and is then discharged from the outlet  33 C. 
     &lt;Printer&gt; 
     As illustrated in  FIG. 1B , the printer  100  includes the cassette mounting portion  101 , the print head  102 , the platen roller  103 , the platen gear  104 , the driving source, the drive shaft  105 , and a movable unit. 
     (Cassette Mounting Portion) 
     The cassette mounting portion  101  is a recessed portion on which the printing cassette  10  may be mounted in an axial direction (i.e., the up-down direction) of the rotation axis of the drive shaft  105 . The cassette mounting portion  101  has a function of positioning the printing cassette  10 . 
     (Print Head) 
     The print head  102  is a device for performing printing on the to-be-printed tape held by the printing cassette  10 . 
     The print head  102  is disposed in the cassette mounting portion  101 . The print head  102  is disposed such that, in a state where the printing cassette  10  is mounted on the printer  100 , the print head  102  overlaps the to-be-printed tape and the ink ribbon in the front-rear direction at the head opening  33 B. 
     The print head  102  has a plurality of heating elements, heat generation of which are individually controlled. The to-be-printed tape that has been conveyed to the head opening  33 B by the platen roller  103  is pressed toward the print head  102  in which the heating elements have generated heat, via the ink ribbon. Thus, some ink on a particular surface of the ink ribbon is transferred onto the to-be-printed tape, and characters, symbols, and other representations are printed on the to-be-printed tape. 
     (Platen Roller) 
     The platen roller  103  is a roller for conveying the to-be-printed tape from the inside to the outside of the printing cassette  10  by a driving force transmitted from the output gear  18 . A rotation axis of the platen roller  103  is parallel to the up-down direction. 
     The platen roller  103  is disposed facing the print head  102  in the cassette mounting portion  101 . The platen roller  103  contacts and presses the to-be-printed tape toward the print head  102  at the head opening  33 B. 
     (Platen Gear) 
     The platen gear  104  may be an external gear that is connected to be driven to the platen roller  103  and is to be engaged with the output gear  18 . 
     In the illustrative embodiment, a rotation axis of the platen gear  104  is coaxial with the rotation axis of the platen roller  103 . In addition, the platen gear  104  is disposed upstream from (i.e., above) the platen roller  103  in the mounting direction of the printing cassette  10  to the cassette mounting portion  101 . 
     (Movable Unit) 
     The movable unit  107  is attached to a housing  110  so as to be swingable in a plane perpendicular to the up-down direction. The platen roller  103  and the platen gear  104  are supported by the movable unit  107  so as to be swingable with respect to the housing  110 . 
     The platen roller  103  and the platen gear  104  are swingable between a position illustrated in  FIG. 10A  where the platen roller  103  and the platen gear  104  are spaced from the printing cassette  10  and a position illustrated in  FIG. 10B  where the platen gear  104  is in engagement with the output gear  18  by swinging of the movable unit  107 . 
     (Drive Shaft) 
     The drive shaft  105  illustrated in  FIG. 1B  is a shaft that is engaged with the input gear  19  when the drive shaft  105  is inserted into the input spool  16 , and that rotates the input spool  16  and the input gear  19 . The drive shaft  105  has external teeth that is to be engaged with the spline teeth  16 B of the input spool  16  and the internal gear  19 B of the input gear  19 . 
     The drive shaft  105  is disposed in the cassette mounting portion  101 . A rotation axis of the drive shaft  105  is parallel to the up-down direction. The drive shaft  105  is rotatable about its rotation axis by a driving source (e.g., a motor). The driving source generates a driving force to be input to the printing cassette  10 . 
     In a state where the printing cassette  10  is mounted on the cassette mounting portion  101 , at least a portion of the drive shaft  105  is positioned in the input spool  16 . In this state, the drive shaft  105  is engaged with the input gear  19  and the platen gear  104  is engaged with the output gear  18 . 
     Specifically, the drive shaft  105  is inserted into the input spool  16  and the input gear  19  of the printing cassette  10 , and the platen roller  103  and the platen gear  104  are swung toward the head opening  33 B of the printing cassette  10 , whereby the printing cassette  10  is mounted on the printer  100 . 
     As the input gear  19  is rotated by the drive shaft  105  in a state where the printing cassette  10  is mounted, the output gear  18  is rotated, the platen gear  104  is rotated by the rotation of the output gear  18 , and the platen roller  103  is rotated by the rotation of the platen gear  104 . 
     As illustrated in  10 B, a direction M 1  of a moment about the drive shaft  105  occurring in the printing cassette  10  by conveyance of the to-be-printed tape by the platen roller  103  in a state where the printing cassette  10  is mounted on the cassette mounting portion  101  is the same direction as a drive rotation direction S of the drive shaft  105 . 
     On the other hand, a direction M 2  of a moment about the drive shaft  105  occurring in the printing cassette  10  by reaction received by the output gear  18  from the platen gear  104  in a state where the printing cassette  10  is mounted on the cassette mounting portion  101  is opposite to the drive rotation direction S of the drive shaft  105 . 
     1-2. Effects 
     According to the illustrative embodiment described in detail above, the following effects may be obtained. 
     (1a) The driving force from the driving source of the printer  100  is transmitted to the platen roller  103  via the input gear  19  and the output gear  18  in the printing cassette  10 . 
     That is, the driving force is transmitted to the platen roller  103  only when the printing cassette  10  is mounted on the printer  100 . Therefore, an unexpected rotation of the platen roller  103  may be reduced in a state where the printing cassette  10  is not mounted. 
     (1b) The input gear  19  has the internal gear  19 B that is engaged with the external teeth of the drive shaft  105 , and the output gear  18  and the platen gear  104  are external gears that are engaged with each other. Thus, a higher flexibility may be achieved in placement of gear trains in the printing cassette  10  and the printer  100 . 
     (1c) The driving force may be transmitted from the single drive shaft  105  to the input spool  16  and the input gear  19  at different positions in the axial direction of the rotation axis of the input spool  16  (i.e., the insertion direction of the drive shaft  105 ). Thus, a driving force may be input to both the input spool  16  and the input gear  19  while upsizing of the printing cassette  10  in directions perpendicular to the insertion direction of the drive shaft  105  (i.e., the front-rear direction and the left-right direction) may be avoided. 
     (1d) The platen gear  104  is disposed upstream from the platen roller  103  in the mounting direction of the printing cassette  10  to the cassette mounting portion  101 . Thus, interference between the output gear  18  and the print head  102  may be avoided. Accordingly, upsizing of the cassette due to increase in size of the head opening  33 B. 
     (1e) The direction M 1  of the moment about the drive shaft  105  occurring in the printing cassette  10  by conveyance of the to-be-printed tape by the platen roller  103  is opposite to the direction M 2  of the moment about the drive shaft  105  occurring in the printing cassette  10  by reaction received by the output gear  18  from the platen gear  104 . Thus, the printing cassette  10  may be prevented from rotating in the printer  100 . 
     (1f) The take-up torque of the ink ribbon may be adjusted by the clutch  17 . Thus, ink ribbons having, for example, different widths, thicknesses, and materials may be installed in the printing cassettes  10  having the same shape. 
     2. Second Illustrative Embodiment 
     2-1. Configuration 
     A printing system  1 A illustrated in  FIGS. 11A, 11B  includes a printing cassette  10 A and a printer  100 A. 
     &lt;Printing Cassette&gt; 
     The printing cassette  10 A is identical to the printing cassette  10  of the first illustrative embodiment to which a laminating tape roll  21 , an additional spool  22 , an additional gear  23 , a pinch roller  24 , and a second clutch  17 A illustrated in  FIG. 12 . 
     The printing cassette  10 A includes a third feed spool  25 , a first cover portion  36 , a first case portion  37 , a second case portion  38 , and a second cover portion  39  as alternatives to the input spool  16 , the first cover portion  31 , the first case portion  32 , the second case portion  33 , and the second cover portion  34  of the printing cassette  10  of the first illustrative embodiment. 
     The third feed spool  25  is identical to the input spool  16  except that the third feed spool  25  does not have the spline teeth  16 B. The first cover portion  36 , the first case portion  37 , the second case portion  38 , and the second cover portion  39  are identical to the first cover portion  31 , the first case portion  32 , the second case portion  33 , and the second cover portion  34  that are further extended in the right-left direction, respectively. The other configurations of the printing cassette  10 A are the same as those of the printing cassette  10  of the first illustrative embodiment except for the points described below, and thus a description thereof will be omitted. 
     In the laminating tape roll  21 , a laminating tape used for protecting the to-be-printed tape is wound around the third feed spool  25 . The laminating tape has an adhesive surface to be adhered to the to-be-printed tape on which printing has been performed by the print head  102 . 
     The additional spool  22  is rotatable about its rotation axis. The rotation axis of the additional spool  22  is parallel to the rotation axis of the second feed spool  15  (i.e., the up-down direction). The additional spool  22  is a take-up spool that takes up the ink ribbon by rotation of the additional gear  23 . 
     The additional gear  23  is connected to the additional spool  22  and is in engagement with the idle gear  20 . The additional gear  23  is rotated by a driving force input to the input gear  19  and rotates the additional spool  22 . 
     The additional gear  23  has an external gear  23 A, a plurality of projecting portions  23 B, and a shaft portion  23 C. The external gear  23 A has a rotation axis that is parallel to the up-down direction. The plurality of projecting portions  23 B are disposed around the shaft portion  23 C along a peripheral surface of the shaft portion  23 C. The plurality of projecting portions  23 B and the shaft portion  23 C protrude downward from the external gear  23 A. 
     The pinch roller  24  presses the laminating tape toward the to-be-printed tape on which printing has been performed, in cooperation with a pressing roller  106 . The pinch roller  24  is disposed downstream from the head opening  33 B in the conveyance direction of the to-be-printed tape. 
     The second clutch  17 A connects the input gear  19  to be driven to the additional spool  22 . Specifically, the second clutch  17 A connects the additional gear  23  that is connected to be driven to the input gear  19 , to be driven to the additional spool  22 . The second clutch  17 A includes a spring holder  71  similar to the clutch  17 , and a clutch spring  72 . 
     As illustrated in  FIGS. 13A and 13B , a second cylindrical portion  71 B and a coil portion  72 A of the second clutch  17 A are disposed inside the plurality of projecting portions  23 B of the additional gear  23 . Further, the shaft portion  23 C of the additional gear  23  is inserted into the second cylindrical portion  71 B. 
     A first cylindrical portion  71 A of the second clutch  17 A is fixed to an inner peripheral surface of the additional spool  22 . A first engagement portion and a second engagement portion of the second clutch  17 A are engaged with the plurality of projecting portions  23 B of the additional gear  23 . 
     A fifth shaft portion  39 A provided at the second cover portion  39  is inserted into the first cylindrical portion  71 A of the second clutch  17 A. The additional spool  22  is rotatably supported by the fifth shaft portion  39 A via the first cylindrical portion  71 A. 
     Resistance is applied to the additional spool  22  by sliding friction between the second cylindrical portion  71 B of the spring holder  71  of the second clutch  17 A and the coil portion  72 A of the clutch spring  72 . That is, the second clutch  17 A applies rotational resistance to the take-up spool for the ink ribbon. A torque for taking up the ink ribbon may be set by the rotational resistance of the second clutch  17 A. 
     Further, in the illustrative embodiment, rotational resistance is applied to the laminating tape roll  21  by the clutch  17  that is the same as that used in the first illustrative embodiment. 
     &lt;Printer&gt; 
     The printer  100 A is identical to the printer  100  of the first illustrative embodiment to which the pressing roller  106  illustrated in  FIG. 12  is added. The other configurations of the printer  100 A are the same as those of the printer  100  of the first illustrative embodiment except for the points described below, and thus a description thereof will be omitted. 
     As illustrated in  FIG. 14 , the pressing roller  106  is attached to the movable unit  107  and is configured to be swingable together with the platen roller  103  and the platen gear  104 . That is, the pressing roller  106  are swingable between a position illustrated in  FIG. 15A  where the pressing roller  106  is spaced from the printing cassette  10 A and a position illustrated in  FIG. 15B  where the pressing roller  106  presses the to-be-printed tape and the laminating tape in cooperation with the pinch roller  24 . 
     2-2. Effects 
     According to the illustrative embodiment described in detail above, the following effects may be obtained. 
     (2a) While having the same advantages as those of the first illustrative embodiment, contents printed on the to-be-printed tape may be protected by the laminating tape. 
     3. Other Illustrative Embodiments 
     Although the illustrative embodiments of the disclosure have been described above, it is needless to say that the disclosure is not limited to the above-described illustrative embodiments and may adopt various embodiments. 
     (3a) The printers of the above-described illustrative embodiments are not limited to printers that perform printing using an ink ribbon. The printers may perform printing using a heat-sensitive sheet that is a continuous strip as a to-be-printed tape. In addition, a printing cassette might not necessarily include an ink ribbon roll and a second feed spool. 
     For example, a printing cassette  10 B illustrated in  FIG. 16  is identical to the printing cassette  10  of the first illustrative embodiment including a to-be-printed tape roll  51  of a heat-sensitive sheet and a laminating tape roll  52  of a laminating tape as alternatives to the to-be-printed tape roll  11  and the ink ribbon roll  14 , respectively. 
     In the printing cassette  10 B, the laminating tape roll  52  is wound around the third feed spool  25  of the second illustrative embodiment. The printing cassette  10 B includes the pinch roller  24  of the second illustrative embodiment, but does not include the second feed spool  15 . 
     (3b) In the printing cassettes of the above-described illustrative embodiments, the output unit that transmits a driving force to the platen roller is not limited to a gear. For example, a roller or a spool may be used as the output unit. Further, the input unit to which a driving force from the driving source is input is not limited to a gear. For example, a roller or a spool may be used as the input unit. 
     (3c) In the printing cassette of the second illustrative embodiment, a laminating tape may be wound around the additional spool. 
     For example, a printing cassette  10 C illustrated in  FIG. 17  is identical to the printing cassette  10 A of the second illustrative embodiment in which a laminating tape roll  21  of a laminating tape is wound around the additional spool  22 . The printing cassette  10 C includes the input spool  16  of the first illustrative embodiment as an alternative to the third feed spool  25  of the second illustrative embodiment. The input spool  16  is used as a take-up spool for an ink ribbon. 
     (3d) The printing cassettes according to the above-described illustrative embodiments are not limited to a printing cassette in which a to-be-printed tape roll, an output gear, and an auxiliary tape roll (i.e., an ink ribbon roll or a laminating tape roll) for an auxiliary tape to be used for printing or protecting the to-be-printed tape are arranged in the up-down direction. In the printing cassette, the to-be-printed tape may be disposed overlapping the auxiliary tape roll in a direction perpendicular to the up-down direction. 
     For example, a printing cassette  10 D illustrated in  FIG. 18  includes a first case portion  41 , a second case portion  42 , and a cover portion  43  as alternatives to the first cover portion  36 , the first case portion  37 , the second case portion  38 , and the second cover portion  39  of the printing cassette  10 A of the second illustrative embodiment. 
     The first case portion  41  is identical to the first case portion  37  of  FIG. 12  whose dimension in the right-left direction is adjusted and from which the portion below the inner wall  32 G is removed. The second case portion  42  is identical to the second case portion  38  of  FIG. 12  whose dimension in the right-left direction is adjusted. The cover portion  43  is identical to the second cover portion  39  of  FIG. 12  whose dimension in the right-left direction is adjusted. 
     The to-be-printed tape roll  11  is wound around a third feed spool  25  of the printing cassette  10 D as an alternative to the laminating tape roll  21 . The ink ribbon is taken up by the additional spool  22  as in the second illustrative embodiment. 
     Further, a heat-sensitive sheet may be used as the to-be-printed tape in the printing cassette  10 D. In this case, the printing cassette  10 D does not need to include the ink ribbon roll  14 , the second feed spool  15 , the additional spool  22 , and the additional gear  23 , and includes only the to-be-printed tape roll  11  as a roll. 
     (3e) The printing cassettes of the above-described illustrative embodiments may include two or more idle gears. That is, the printing cassettes may include a transmission gear train that engages with the input gear. Further, the input gear and the output gear may be directly engaged with each other but not via the idle gear. 
     (3f) The functions of a single component in the above-described illustrative embodiments may be achieved by multiple components, or the functions of respective multiple components may be achieved by a single component. Further, some of the configurations of the above-described illustrative embodiments may be omitted. In addition, at least some of the configurations of one or more of the above-described illustrative embodiments may be added to or replaced with the configurations of another embodiment. It should be noted that all aspects included in the technical idea specified by the wording described in the claims are embodiments of the disclosure.