Printing cassette and printing device

Abstract

To provide a cassette for printing which can suppress printing quality degradation caused by engagement of a gear.SOLUTION: A cassette for printing includes a belt-like printing medium, a gear body, a gear having a pitch ring connected to the gear body, and a case storing the printing medium and the gear. At least a part of the gear is exposed to the outside of the case. A diameter of the pitch ring is smaller than a tip diameter of the gear body.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a printing cassette and a printing device. [Background technology]

[0002] In a printing device that prints on a printing tape, a cassette that contains the printing tape is attached to and detached from the main body of the printing device to replace and supply the printing tape. In such a cassette, a configuration in which a gear is provided for inputting a driving force to the cassette or outputting a driving force from the cassette is known (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-234772 A Summary of the Invention [Problem to be solved by the invention]

[0004] The gear on the cassette engages with a gear on the printer body when the cassette is installed. If there is variation in the center distance or meshing rate of these gears when they mesh, the print quality will decrease.

[0005] An object of one aspect of the present disclosure is to provide a printing cassette that can suppress deterioration of print quality caused by gear meshing. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, there is provided a printing cassette including a band-shaped printing medium, a gear having a gear body and a pitch ring connected to the gear body, and a case for accommodating the printing medium and the gear. At least a portion of the gear is exposed to the outside of the case. The diameter of the pitch ring is smaller than the tip diameter of the gear body.

[0007] With this configuration, the pitch ring can keep the center distance constant when the gears are meshed. Also, because the diameter of the pitch ring is smaller than the tip circle diameter of the gear body, damage to the pitch ring when the printing cassette falls and hits the floor or the like can be suppressed. Therefore, deterioration of printing quality due to deterioration of the shape accuracy of the pitch ring can be suppressed.

[0008] Another aspect of the present disclosure is a printing cassette including a band-shaped print medium, a gear having a gear body and a pitch ring connected to the gear body, and a case for accommodating the print medium and the gear, wherein at least a portion of the gear is exposed to the outside of the case, and at least a portion of the pitch ring is disposed between the gear body and the case in the axial direction of the gear.

[0009] With this configuration, the pitch ring can keep the center distance constant when the gears are engaged. Also, by disposing at least a part of the pitch ring between the gear body and the case, damage to the pitch ring when the printing cassette falls and hits the floor or the like can be suppressed. Therefore, deterioration of printing quality due to deterioration of the shape accuracy of the pitch ring can be suppressed.

[0010] Another aspect of the present disclosure is a printing device including a printing device main body and a printing cassette mountable to the printing device main body. The printing device main body has a print head, a platen roller that faces the print head and is swingable relative to the print head, a pressing member that presses the platen roller toward the print head, and a first gear that is connected to the platen roller and has a first gear body and a first pitch ring connected to the first gear body.

[0011] The printing cassette has a strip-shaped printing medium that is printed by the print head while being sandwiched between the print head and the platen roller, and a second gear having a second gear body and a second pitch ring connected to the second gear body.

[0012] When the printing cassette is attached to the printing device body, the first gear body and the second gear body engage with each other, and the first pitch ring and the second pitch ring contact each other in the radial direction of the first gear. The pressing member, the first gear body, and the first pitch ring are arranged in the axial direction of the first gear in the following order: pressing member, first gear body, and first pitch ring.

[0013] With this configuration, the pitch ring can keep the center distance constant when the gears are engaged. Also, because the first gear body and the pressing member are close to each other in the axial direction of the first gear, the effect of the engagement force between the first gear body and the second gear body on the nip load of the platen roller on the printing medium can be reduced. As a result, deterioration of print quality due to variations in nip load can be suppressed. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1A is a schematic perspective view showing a printing apparatus according to an embodiment, and FIG. 1B is a schematic perspective view showing a main body of the printing apparatus shown in FIG. 1A. [Diagram 2] FIG. 2A is a schematic cross-sectional view showing the structure around the platen roller of the printing apparatus of FIG. 1A, and FIG. 2B is a schematic view showing the platen shaft and the pressing member. [Diagram 3] 3A, 3B and 3C are schematic perspective views of the printing cassette of FIG. 1A. [Figure 4] FIG. 4 is a schematic exploded perspective view of the printing cassette of FIG. 3A. [Diagram 5] FIG. 5 is a schematic cross-sectional view taken along line VV in FIG. 3C. [Figure 6] FIG. 6 is a schematic perspective view showing an engagement state between an output gear and a platen gear in the printing device of FIG. 1A. [Figure 7] FIG. 7 is a schematic perspective view showing the printing cassette of FIG. 3C with the first lid portion removed. [Figure 8] FIG. 8 is a schematic diagram for explaining the paths of the printing tape and the ink ribbon in the printing cassette of FIG. 3A. [Figure 9] 9A is a schematic cross-sectional view taken along line IXA-IXA in FIG. 3C, FIG. 9B is a schematic cross-sectional view taken along line IXB-IXB in FIG. 3C, FIG. 9C is a schematic cross-sectional view taken along line IXC-IXC in FIG. 3C, and FIG. 9D is a schematic cross-sectional view taken along line IXD-IXD in FIG. 3C. [Figure 10] FIG. 10A is a schematic side view showing an engagement state between an output gear and a platen gear in an embodiment different from that in FIG. 6, and FIG. 10B is a schematic perspective view of the output gear in FIG. 10A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] [1. First embodiment] [1-1. Configuration] 1A includes a printing cassette 10 and a printing device main body 100. The printing device 1 is a device that prints on a printing tape 11A (an example of a band-shaped printing medium).

[0016] In this embodiment, the axial direction of the output gear 21 is defined as the up-down direction, the direction perpendicular to the up-down direction in which the printing tape 11A is transported at the head opening 33B is defined as the left-right direction, and the direction perpendicular to both the up-down direction and the left-right direction is defined as the front-rear direction.

[0017] <Printing device body> As shown in FIG. 1B, the printing apparatus main body 100 includes a cassette storage section 101, a printing section 102, a platen roller 103, a platen gear 104 (an example of a first gear), a roller holder 105, a drive shaft 106, a drive source 107, and a housing 110.

[0018] (Cassette storage section) The cassette storage section 101 is a recess in which the printing cassette 10 is attached. The cassette storage section 101 has a function of positioning the printing cassette 10. The cassette storage section 101 is provided in a housing 110.

[0019] (Printing Department) The printing unit 102 is disposed inside the cassette storage unit 101. As shown in Fig. 2A, the printing unit 102 has a print head 102A and a heat sink 102B.

[0020] The print head 102A has multiple heat generating elements whose heat generation is individually controlled. The heat sink 102B holds the print head 102A. The heat sink 102B is a metal plate arranged so that its thickness direction is parallel to the front-rear direction, and the print head 102A is attached to its front surface. The heat sink 102B has the function of dissipating heat from the print head 102A.

[0021] (Platen roller) The platen roller 103 is disposed inside the cassette storage unit 101 in the vicinity of the print head 102A so as to face the print head 102A.

[0022] The platen roller 103 is held by a roller holder 105, and can swing toward or away from the print head 102A. A rotation axis L1 of the platen roller 103 is parallel to the vertical direction.

[0023] The platen roller 103 has a platen shaft 103A, a roller sleeve 103B, and a roller rubber 103C. The platen shaft 103A is supported by a roller holder 105. The platen shaft 103A is inserted into a roller sleeve 103B having a roller rubber 103C attached to its outer circumferential surface.

[0024] (Platen gear) The platen gear 104 is connected to the platen roller 103. Specifically, the platen gear 104 is connected to the upper end of the platen shaft 103A.

[0025] In this embodiment, the rotation axis L2 of the platen gear 104 is disposed on the same line as the rotation axis L1 of the platen roller 103. The platen gear 104 is capable of swinging together with the platen roller 103.

[0026] The platen gear 104 has a first gear body 104A and a first pitch ring 104B. The first gear body 104A meshes with an output gear 21 (an example of a second gear) of the printing cassette 10. The first pitch ring 104B is connected to an upper end of the first gear body 104A.

[0027] The outer shape of the first pitch ring 104B is a perfect circle. The central axis of the first gear body 104A and the central axis of the first pitch ring 104B coincide with each other. The diameter of the first pitch ring 104B is larger than the diameter of the tooth tip circle of the first gear body 104A.

[0028] (Roller holder) The roller holder 105 moves the platen roller 103 and the platen gear 104 relative to the printing unit 102 .

[0029] The roller holder 105 has a holder body 105A, a first pressing member 105B, and a second pressing member 105C. The holder body 105A is attached to the housing 110 so as to be swingable in the front-rear direction. The holder body 105A also supports the platen shaft 103A so as to be rotatable about its axis.

[0030] The first pressing member 105B and the second pressing member 105C are each held by the holder main body 105A. The first pressing member 105B and the second pressing member 105C are elastic members that press the platen roller 103 towards the print head 102A.

[0031] 2B, the first pressing member 105B and the second pressing member 105C are each a torsion coil spring with one end abutting the platen shaft 103A from the front. The central axes of the first pressing member 105B and the second pressing member 105C are parallel to the central axis of the platen shaft 103A. The other ends of the first pressing member 105B and the second pressing member 105C are fixed to the holder main body 105A.

[0032] The first pressing member 105B is disposed above the second pressing member 105C. The first pressing member 105B and the second pressing member 105C are disposed at positions sandwiching the roller sleeve 103B in the vertical direction.

[0033] The first pressing member 105B is located below the platen gear 104. In other words, the first pressing member 105B, the first gear body 104A, and the first pitch ring 104B are arranged in the axial direction of the platen gear 104 in the following order: first pressing member 105B, first gear body 104A, and first pitch ring 104B.

[0034] (Drive shaft) 1B is inserted into the take-up spool 16 and the input gear 22 of the printing cassette 10. The drive shaft 106 inputs a driving force to the printing cassette 10 to rotate the take-up spool 16 and the input gear 22.

[0035] The drive shaft 106 is disposed inside the cassette storage unit 101. The rotation axis L3 of the drive shaft 106 is parallel to the vertical direction. The drive shaft 106 is rotated by a drive source 107 about the rotation axis L3.

[0036] (Drive source) The driving source 107 rotates the driving shaft 106. As the driving source 107, for example, a mechanism combining a motor and a gear can be used.

[0037] <Printing cassette> The printing cassette 10 stores a printing tape 11A. The printing cassette 10 can be attached to and detached from the printing device main body 100. By replacing the printing cassette 10, it is possible to replenish printing media and change the type of printing media (e.g., size, color, material, etc.).

[0038] As shown in FIGS. 3A, 3B, and 3C, the printing cassette 10 includes a case 35 that houses at least a portion of the printing tape 11A and at least a portion of the ink ribbon 14A.

[0039] The outer shape of the printing cassette 10 (i.e., the shape of the case 35) is a rectangular parallelepiped with 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 can be inserted downward into the cassette storage section 101.

[0040] As shown in Figure 4, the printing cassette 10 comprises a first roll 11, a first supply spool 12, spacer films 13A, 13B, a second roll 14, a second supply spool 15, a take-up spool 16, a clutch spring holder 17, and a drive transmission mechanism 20.

[0041] (1st roll) The first roll 11 is formed by winding a printing tape 11A on which printing is to be performed around a first supply spool 12. Printing is performed on the surface of the printing tape 11A by a print head 102A and an ink ribbon 14A of the printing device main body 100.

[0042] Two spacer films 13A and 13B are disposed on the outer sides of the first roll 11 in the vertical direction so as to sandwich the first roll 11. The spacer films 13A and 13B are disposed between the first roll 11 and the first lid portion 31 and between the first roll 11 and the gear case portion 32.

[0043] (1st supply spool) The first supply spool 12 is rotatable about a rotation axis L4 that is parallel to the vertical direction. The first supply spool 12 rotates in association with the transport of the printing tape 11A by the platen roller 103 of the printing apparatus main body 100, thereby supplying the printing tape 11A to the print head 102A. The rotation axis L4 of the first supply spool 12 coincides with the winding axis of the first roll 11.

[0044] (2nd roll) The second roll 14 is formed by winding an ink ribbon 14A used for printing on the printing tape 11A around a second supply spool 15.

[0045] The ink ribbon 14A is overlapped with the printing tape 11A at the head opening 33B, and is used for printing by the print head 102A. The ink ribbon 14A used for printing is taken up by the take-up spool 16.

[0046] A rotational resistance is applied to the second roll 14 by a clutch spring (not shown) held by a clutch spring holder 17. At least a portion of the second roll 14 is disposed at a position overlapping with the first roll 11 in the vertical direction.

[0047] (2nd supply spool) The second supply spool 15 is rotatable about a rotation axis L5. The rotation axis L5 of the second supply spool 15 is parallel to the up-down direction and coincides with the rotation axis of the second roll 14. The second supply spool 15 rotates in association with the winding of the ink ribbon 14A by the take-up spool 16, thereby supplying the ink ribbon 14A to the print head 102A.

[0048] (Take-up spool) The take-up spool 16 is rotatable about a rotation axis L6 which is parallel to the rotation axis L5 of the second supply spool 15.

[0049] The take-up spool 16 is cylindrical and has a hollow portion defined by an inner circumferential surface 16A. The inner circumferential surface 16A of the take-up spool 16 is provided with spline teeth 16B. A drive shaft 106 of the printing device main body 100 is connected to the spline teeth 16B. The take-up spool 16 is rotated by the drive shaft 106 and takes up the ink ribbon 14A.

[0050] (Drive transmission mechanism) When the printing cassette 10 is attached to the printing device main body 100, the drive transmission mechanism 20 transmits the driving force of the drive source 107, which is transmitted from the drive shaft 106, to the platen roller 103. The drive transmission mechanism 20 has an output gear 21, an input gear 22, and an idle gear 23.

[0051] As shown in FIG. 5, the first roll 11, the drive transmission mechanism 20, and the take-up spool 16 are arranged in the vertical direction in the order of the first roll 11, the drive transmission mechanism 20, and the take-up spool 16.

[0052] (Output gear) 4 is an externally toothed gear for outputting the driving force used to transport the print tape 11A to the outside. Specifically, the output gear 21 transmits the driving force from the outside to the platen gear 104 of the printing device main body 100.

[0053] The rotation axis L7 of the output gear 21 is parallel to the rotation axis L5 of the second supply spool 15. The entire output gear 21 overlaps with the cover portion 32B of the case 35 in the vertical direction. In addition, at least a portion of the output gear 21 is exposed to a space communicating with the head opening 33B (i.e., the outside of the case 35).

[0054] 6, the output gear 21 has a second gear body 21A and a second pitch ring 21B. The second gear body 21A meshes with the platen gear 104 of the printing device body 100 in a space communicating with the head opening 33B. The second pitch ring 21B is connected to the upper end of the second gear body 21A.

[0055] The outer shape of the second pitch ring 21B is a perfect circle. The central axis of the second gear body 21A and the central axis of the second pitch ring 21B coincide with each other. The diameter of the second pitch ring 21B is smaller than the tip circle diameter of the second gear body 21A.

[0056] When the printing cassette 10 is attached to the printing device main body 100 (i.e., when the case 35 is stored in the cassette storage section 101), the first gear body 104A of the platen gear 104 and the second gear body 21A of the output gear 21 engage with each other, and the first pitch ring 104B of the platen gear 104 and the second pitch ring 21B of the output gear 21 come into radial contact with each other on the platen gear 104.

[0057] The first pitch ring 104B and the second pitch ring 21B are in contact with each other at their outer circumferential surfaces. The first pitch ring 104B and the second pitch ring 21B are in sliding contact with each other as the first gear body 104A and the second gear body 21A rotate.

[0058] The sum of the pitch circle diameter of the first gear body 104A and the pitch circle diameter of the second gear body 21A is equal to the sum of the diameter of the first pitch ring 104B and the diameter of the second pitch ring 21B. In other words, the center-to-center distance between the first gear body 104A and the second gear body 21A is equal to the center-to-center distance between the first pitch ring 104B and the second pitch ring 21B.

[0059] (Input gear) The input gear 22 shown in FIG. 4 is indirectly engaged with the output gear 21 via an idle gear 23, and transmits driving force to the output gear 21.

[0060] The input gear 22 has an external gear 22A and a spool 22B which is a cylindrical internal gear having spline teeth on its inner peripheral surface and is fixed to one side of the external gear 22A. The external gear 22A rotates integrally with the spool 22B by the driving force of the driving source 107 input to the spool 22B.

[0061] A rotation axis L8 of the input gear 22 (i.e., a rotation axis of the external gear 22A and a rotation axis of the spool 22B) is disposed on the same line as a rotation axis L6 of the take-up spool 16. At least a portion of the input gear 22 is disposed at a position overlapping with the first roll 11 in the vertical direction.

[0062] The rotation axis L8 of the input gear 22 overlaps with the hollow portion of the take-up spool 16 in the vertical direction. Therefore, when the printing cassette 10 is attached to the printing device main body 100, the drive shaft 106 is inserted through the take-up spool 16 and the input gear 22 at the same time. As a result, the input gear 22 is not directly connected to the take-up spool 16, but is rotated together with the take-up spool 16 by the drive shaft 106.

[0063] (Idol Gear) The idle gear 23 is drivingly connected (ie, engaged) with the input gear 22 and the output gear 21 , and transmits the driving force input to the input gear 22 to the output gear 21 .

[0064] The idle gear 23 is a stepped gear in which an upstream gear 23A engaged with the input gear 22 and a downstream gear 23B engaged with the output gear 21 are arranged side by side on the same axis. The downstream gear 23B has a smaller diameter than the upstream gear 23A. The downstream gear 23B is arranged closer to the first roll 11 (i.e., higher) than the upstream gear 23A in the up-down direction.

[0065] The idle gear 23 reduces the rotational speed of the driving force input to the input gear 22 and transmits it to the output gear 21. In other words, the drive transmission mechanism 20 includes a reduction mechanism having a transmission ratio obtained by dividing the rotational speed of the input gear 22 by the rotational speed of the output gear 21 as a reduction gear ratio.

[0066] (case) The case 35 has a first lid portion 31, a gear case portion 32, an ink ribbon case portion 33, and a second lid portion .

[0067] The first lid part 31 constitutes the upper end part of the printing cassette 10. The gear case part 32 is disposed below the first lid part 31 and is connected to the first lid part 31 in the vertical direction. The ink ribbon case part 33 is disposed below the gear case part 32 and is connected to the gear case part 32 in the vertical direction.

[0068] That is, the ink ribbon case part 33 is disposed so as to be vertically overlapped with the gear case part 32. The second lid part 34 constitutes the lower end part of the printing cassette 10. The second lid part 34 is connected to the ink ribbon case part 33 in the vertical direction.

[0069] The first lid portion 31 and the gear case portion 32 constitute a first housing portion 41 that houses the first roll 11. In other words, the first roll 11 is disposed in a space surrounded by the first lid portion 31 and the gear case portion 32.

[0070] The second lid portion 34 and the ink ribbon case portion 33 constitute a second housing portion 42 that houses the second roll 14, the second supply spool 15, and the take-up spool 16. In other words, the second roll 14, the second supply spool 15, and the take-up spool 16 are disposed in a space surrounded by the second lid portion 34 and the ink ribbon case portion 33.

[0071] The gear case section 32 and the ink ribbon case section 33 constitute a third housing section 43 that houses a part of the output gear 21, the input gear 22, and the idle gear 23. In other words, the part of the output gear 21, the input gear 22, and the idle gear 23 are disposed in a space surrounded by the gear case section 32 and the ink ribbon case section 33. The third housing section 43 is disposed between the first housing section 41 and the second housing section 42 in the up-down direction.

[0072] The gear case portion 32 has a first side wall 32A, a cover portion 32B (an example of a wall portion), and a first guide 32C. The first side wall 32A constitutes an outer surface of the case 35 that is parallel to the up-down direction.

[0073] The cover portion 32B is a portion having a surface perpendicular to the up-down direction. The cover portion 32B is provided continuous with the lower end portion of the first side wall 32A and is disposed at the right front corner portion of the gear case portion 32.

[0074] The cover portion 32B is disposed at a position overlapping at least a portion of the second pitch ring 21B of the output gear 21 (in this embodiment, the entire second pitch ring 21B) in the up-down direction.

[0075] The cover portion 32B is located above the second pitch ring 21B. At least a portion of the second pitch ring 21B is disposed between the second gear body 21A and the case 35 (specifically, the cover portion 32B) in the axial direction of the output gear 21. In this embodiment, the entire second pitch ring 21B overlaps with the case 35 in the axial direction of the output gear 21.

[0076] 7, the first guide 32C is a portion around which the printing tape 11A pulled out from the first roll 11 is wound. The first guide 32C has multiple plate-shaped ribs spaced apart along the circumferential direction of the first roll 11. The multiple ribs protrude in the radial direction of the first roll 11, and the amount of protrusion (i.e., plate width) increases downward.

[0077] 4 has a second side wall 33A, a head opening 33B, a discharge port 33C, and a second guide 33D. The second side wall 33A constitutes an outer surface of the case 35 that is parallel to the up-down direction.

[0078] The head opening 33B is formed by cutting out a portion of the second side wall 33A. The head opening 33B is a space in which the print head 102A is disposed when the printing cassette 10 is attached to the printing device main body 100.

[0079] In the head opening 33B, printing is performed on the printing tape 11A by the print head 102A. The head opening 33B opens below the printing cassette 10 so that the print head 102A can be inserted from below.

[0080] 8, the printing tape 11A and the ink ribbon 14A are hung in the left-right direction in the head opening 33B. The printing tape 11A is exposed to the outside of the case 35 in the head opening 33B and overlaps the ink ribbon 14A.

[0081] Printing is performed on the printing tape 11A by the printing head 102A while the printing tape 11A is sandwiched between the printing head 102A and the platen roller 103. After printing, the printing tape 11A is discharged to the outside of the printer 1 from the discharge port 33C.

[0082] The head opening 33B is disposed below the cover portion 32B. The second gear body 21A of the output gear 21 is disposed between the cover portion 32B and the head opening 33B in the axial direction of the output gear 21.

[0083] Further, second pitch ring 21B, second gear body 21A, and head opening 33B are arranged in the following order in the up-down direction: second pitch ring 21B, second gear body 21A, and head opening 33B.

[0084] Similar to the first guide 32C, the second guide 33D is a portion around which the printing tape 11A pulled out from the first roll 11 is wound. The second guide 33D has a number of plate-shaped ribs spaced apart along the circumferential direction of the second roll 14. The multiple ribs protrude in the radial direction of the second roll 14, and the amount of protrusion (i.e., plate width) decreases the further downward.

[0085] As shown in FIGS. 9A, 9B, 9C, and 9D, the first guide 32C and the second guide 33D form a passage for feeding the printing tape 11A constituting the first roll 11 from the first container 41 to the second container .

[0086] Specifically, as shown in Fig. 9A, the printing tape 11A pulled out from the first roll 11 is transported downward and rearward within the first housing section 41 while contacting the first guide 32C from the radially outer side of the first roll 11 in a spiral manner. The printing tape 11A is further transported downward and leftward while vertically straddling the third housing section 43 as shown in Fig. 9B.

[0087] The printing tape 11A that has reached the second storage section 42 is transported downward and forward while contacting the second guide 33D from the radially outer side, as shown in Fig. 9C. The printing tape 11A that has reached the lower end of the printing cassette 10 passes through the head opening 33B and is discharged to the right from the discharge opening 33C, as shown in Fig. 9D.

[0088] <Tape transport and printing by the printer body> When the printing cassette 10 is attached to the printing device main body 100, the print head 102A is disposed at a position in the head opening 33B where it overlaps with the printing tape 11A and the ink ribbon 14A in the front-rear direction.

[0089] The printing tape 11A is transported to the head opening 33B by the platen roller 103, and is pressed against the print head 102A, whose heating elements have generated heat, via the ink ribbon 14A by the platen roller 103. As a result, part of the ink arranged on the surface of the ink ribbon 14A is transferred to the printing tape 11A, and characters, symbols, etc. are printed on the printing tape 11A.

[0090] The platen roller 103 transports the printing tape 11A after printing from inside the printing cassette 10 to the outside. The platen roller 103 is rotated by a platen gear 104 engaged with the output gear 21. The platen roller 103 and the platen gear 104 are capable of swinging between a position separated from the printing cassette 10 and a position where the platen gear 104 is engaged with the output gear 21.

[0091] When the case 35 of the printing cassette 10 is inserted into the cassette storage section 101 , the drive shaft 106 engages with the input gear 22 , and the platen gear 104 engages with the output gear 21 .

[0092] Specifically, with the drive shaft 106 inserted into the take-up spool 16 and input gear 22 of the printing cassette 10, the platen roller 103 and the platen gear 104 swing toward the head opening 33B of the printing cassette 10, causing the platen gear 104 to engage with the output gear 21.

[0093] With the printing cassette 10 attached, the input gear 22 is rotated by the drive shaft 106, thereby rotating the output gear 21. Furthermore, the rotation of the output gear 21 rotates the platen gear 104, and the rotation of the platen gear 104 rotates the platen roller 103.

[0094] [1-2. Effects] According to the embodiment described above in detail, the following effects can be obtained. (1a) The first pitch ring 104B and the second pitch ring 21B can keep the center distance between the platen gear 104 and the output gear 21 constant when they are engaged with each other.

[0095] (1b) Because the diameter of the second pitch ring 21B is smaller than the diameter of the tooth tip circle of the second gear body 21A, damage to the second pitch ring 21B when the printing cassette 10 falls and hits the floor surface, etc., can be suppressed. Therefore, deterioration of printing quality due to deterioration of the shape accuracy of the second pitch ring 21B can be suppressed.

[0096] (1c) At least a portion of the second pitch ring 21B is disposed between the second gear body 21A and the case 35, so that damage to the second pitch ring 21B when the printing cassette 10 falls and hits the floor surface, etc., can be suppressed. Therefore, deterioration of printing quality due to deterioration of the shape accuracy of the second pitch ring 21B can be suppressed.

[0097] (1d) In the axial direction of the output gear 21, the entire second pitch ring 21B overlaps with the case 35, which enhances the effect of suppressing damage to the second pitch ring 21B. (1e) By disposing the second gear body 21A between the cover portion 32B and the head opening 33B in the axial direction of the output gear 21, the output gear 21 can be brought close to the platen roller 103 while the cover portion 32B can prevent damage to the output gear 21.

[0098] (1f) Since the first gear body 104A and the first pressing member 105B are close to each other in the axial direction of the platen gear 104, it is possible to reduce the effect of the meshing force between the first gear body 104A and the second gear body 21A on the nip load of the platen roller 103 to the printing tape 11A. As a result, it is possible to suppress deterioration of print quality due to variations in the nip load.

[0099] 2. Other embodiments Although the embodiments of the present disclosure have been described above, it goes without saying that the present disclosure is not limited to the above-described embodiments and can take various forms.

[0100] (2a) The printing device of the above embodiment is not limited to one that uses an ink ribbon for printing. For example, the printing device may print on a strip of thermal paper. In other words, the printing cassette does not necessarily have to include an ink ribbon.

[0101] The printing device may also use a stencil tape as the printing medium, in which holes for a printing pattern are punched by a thermal head. When the stencil tape is used as the printing medium, a slip sheet tape is used to protect the stencil tape instead of the ink ribbon.

[0102] (2b) In the printing device of the above embodiment, as shown in Figures 10A and 10B, the diameter of the second pitch ring 21B of the output gear 21 may be larger than the tip circle diameter of the second gear body 21A. In this case, the diameter of the first pitch ring 104B of the platen gear 104 is made smaller than the tip circle diameter of the first gear body 104A.

[0103] (2c) The function of one component in the above embodiments may be distributed as multiple components, or the functions of multiple components may be integrated into one component. In addition, a part of the configuration of the above embodiments may be omitted. In addition, at least a part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments. Note that all aspects included in the technical idea identified from the wording described in the claims are embodiments of the present disclosure. [Explanation of symbols]

[0104] 1...printing device, 10...printing cassette, 11...first roll, 11A...printing tape, 12: first supply spool; 14: second roll; 14A: ink ribbon; 15: second supply spool; 16: take-up spool; 21: output gear; 21A: second gear body; 21B: second pitch ring; 22: input gear; 23... idle gear, 32... gear case portion, 32B... cover portion, 33: ink ribbon case portion; 33B: head opening; 33C: discharge port; 35: case; 100: Printing device main body, 101: Cassette storage section, 102A: Print head, 103... platen roller, 103A... platen shaft, 103B... roller sleeve, 103C... roller rubber, 104... platen gear, 104A... first gear body, 104B: first pitch ring, 105B: first pressing member, 106: drive shaft.

Claims

1. A strip of printing medium; a gear having a gear body and a pitch ring connected to the gear body; a case that accommodates the print medium and the gear; Equipped with At least a portion of the gear is exposed to the outside of the case, The diameter of the pitch ring is smaller than the tip diameter of the gear body, The case is a wall portion overlapping at least a portion of the pitch ring in the axial direction of the gear; a head opening through which printing is performed on the print medium; having The gear body is disposed between the wall portion and the head opening in the axial direction of the gear.

2. A strip of printing medium; a gear having a gear body and a pitch ring connected to the gear body; a case that accommodates the print medium and the gear; Equipped with At least a portion of the gear is exposed to the outside of the case, The diameter of the pitch ring is smaller than the tip diameter of the gear body, The gear is an output gear that outputs a driving force to the outside.

3. A printing cassette as described in claim 1 or claim 2, wherein at least a portion of the pitch ring is positioned between the gear and the case in the axial direction of the gear.

4. A strip of printing medium; a gear having a gear body and a pitch ring connected to the gear body; a case that accommodates the print medium and the gear; Equipped with At least a portion of the gear is exposed to the outside of the case, At least a portion of the pitch ring is disposed between the gear body and the case in the axial direction of the gear, The case is a wall portion overlapping at least a portion of the pitch ring in the axial direction of the gear; a head opening through which printing is performed on the print medium; having The gear body is disposed between the wall portion and the head opening in the axial direction of the gear.

5. A strip-shaped printing medium; a gear having a gear body and a pitch ring connected to the gear body; a case that accommodates the print medium and the gear; Equipped with At least a portion of the gear is exposed to the outside of the case, At least a portion of the pitch ring is disposed between the gear body and the case in the axial direction of the gear, The gear is an output gear that outputs a driving force to the outside.

6. A printing cassette as described in claim 4 or claim 5, wherein the diameter of the pitch ring is smaller than the tooth tip circle diameter of the gear body.

7. A printing cassette as described in claim 4 or claim 5, wherein the diameter of the pitch ring is larger than the tooth tip circle diameter of the gear body.

8. A printing cassette as described in any one of claims 3 to 7, wherein the entire pitch ring overlaps the case in the axial direction of the gear.

9. A printing device body, a printing cassette that can be attached to the printing device body; Equipped with The printing device body includes: A print head; a platen roller that faces the print head and is swingable relative to the print head; a pressing member that presses the platen roller toward the print head; a first gear connected to the platen roller and having a first gear body and a first pitch ring connected to the first gear body; having The printing cassette comprises: a band-shaped print medium that is sandwiched between the print head and the platen roller and that is printed on by the print head; a second gear having a second gear body and a second pitch ring coupled to the second gear body; having When the printing cassette is attached to the printing device body, the first gear body and the second gear body are engaged with each other, and the first pitch ring and the second pitch ring are in contact with each other in a radial direction of the first gear, a first gear body and a first pitch ring arranged in this order in an axial direction of the first gear;

10. 10. The printing apparatus of claim 9, wherein a sum of a pitch diameter of the first gear body and a pitch diameter of the second gear body is equal to a sum of a diameter of the first pitch ring and a diameter of the second pitch ring.

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