Printer

Abstract

The invention discloses a printer capable of preventing loosening of a ribbon during returning, the printer includes a feed shaft, a winding shaft, a conveyance portion, a print head, and a rotation force generation mechanism. The feed shaft rotatably holds a supply roller on which a color tape is wound. The winding shaft rotatably holds a recovery roller on which the ribbon fed from the supply roller is wound. The conveyance section conveys a medium to be printed along the ribbon moving from the supply roller to the recovery roller. The print head performs printing by bringing the ribbon into contact with the medium to be printed conveyed by the conveyance unit. The rotation force generating mechanism generates a rotation force in a direction in which the ribbon is wound around the winding shaft when the feeding shaft is rotated in a direction opposite to a feeding direction of the ribbon and the ribbon is fed back in the opposite direction.

Description

[0001] This application claims priority from Japanese patent application filed on September 22, 2023, with application number JP2023-159053, and cites the contents of the above application, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0002] Embodiments of the present invention relate to a printer that uses a ribbon to print on a print medium. Background Art

[0003] A printer that prints on a print medium using a ribbon comprises a delivery shaft on which a supply roller wound with a ribbon is mounted, a print head, and a winding shaft on which a recovery roller wound with a used ribbon is mounted. When the printer is used to print on a print medium, the print medium is conveyed, the ribbon is fed from the supply roller, the print medium and the ribbon are overlapped and passed through the print head, and the used ribbon after printing is recovered by the recovery roller.

[0004] The ribbon may become loose or wrinkled due to printing. If the ribbon becomes loose or wrinkled, poor printing may occur. Therefore, printers using the ribbon usually have a mechanism for eliminating the looseness or wrinkles of the ribbon.

[0005] It is known that the slack or wrinkles of the ribbon can be eliminated by, for example, feeding the ribbon back in the opposite direction. When the ribbon is fed back, the feed shaft is rotated in the opposite direction and the used ribbon is pulled out from the recovery roller.

[0006] However, when the ink ribbon is fed back, after the reverse rotation of the feed shaft is stopped, the recovery roller may continue to rotate due to inertia, and new slack may occur in the ink ribbon between the ink ribbon and the print head. Summary of the invention

[0007] In view of the above problems, the problem to be solved by the present invention is to provide a printer capable of preventing the ribbon from being loosened when being fed back.

[0008] In order to solve the above problems, the printer of the embodiment comprises a feed shaft, a winding shaft, a conveying unit, a print head and a rotational force generating mechanism. The feed shaft rotatably holds a supply roller on which a ribbon is wound. The winding shaft rotatably holds a recovery roller on which a ribbon fed from the feed roller is wound. The conveying unit conveys a printed medium along the ribbon moving from the feed roller to the recovery roller. The print head prints by bringing the ribbon into contact with the printed medium conveyed by the conveying unit. The rotational force generating mechanism generates a rotational force in the direction in which the ribbon is wound on the winding shaft when the feed shaft is rotated in the opposite direction to the feed direction of the ribbon and the ribbon is moved in the opposite direction.

[0009] According to the above-mentioned printer, it is possible to prevent the ink ribbon from being loosened when it is fed back.

[0010] In the above-mentioned printer, the rotational force generating mechanism comprises: a one-way bearing having a rotating component, which rotates idly when the winding axis rotates in the winding direction, and rotates integrally with the winding axis during the return movement in which the winding axis rotates in the direction opposite to the winding direction; and an elastic component, which is elastically deformed by the rotation of the rotating component in the opposite direction, and rotates the rotating component in the winding direction by its restoring force.

[0011] According to the above printer, the elastic member can keep the ink ribbon in a state of constant tension during the return.

[0012] In the above printer, the elastic member may be a tension spring having one end fixed to the rotating member, and being stretched by the rotating member rotating in the opposite direction and wound around the rotating member.

[0013] According to the above-mentioned printer, the tension spring can prevent the ink ribbon from being loosened.

[0014] The above printer further includes a pressing plate fixed to the rotating member and constituting a retaining groove for restricting the movement of the tension spring and winding the tension spring together with the rotating member.

[0015] According to the above-described printer, the tension spring can be reliably restrained.

[0016] In the above printer, the other end of the tension spring is fixed on the pressure plate.

[0017] According to the above-described printer, the tension spring can be fixed to the platen.

[0018] In the above-mentioned printer, the rotational force generating mechanism comprises: a one-way bearing, which allows the rotating component to rotate idly when the winding shaft rotates in the winding direction, and transmits the rotational force of the winding shaft to the rotating component during the return movement in which the winding shaft rotates in the direction opposite to the winding direction; and an elastic component, which applies a rotational force in the winding direction to the winding shaft during the return movement.

[0019] According to the above printer, the elastic member can keep the ink ribbon in a state of constant tension during the return.

[0020] The above printer further includes: a wheel connected to the winding shaft; and a rotating shaft penetrating the wheel and being coaxially and integrally connected to the winding shaft.

[0021] According to the above-described printer, the winding shaft can be easily mounted.

[0022] In the above printer, the wheel receives and meshes with the bevel-toothed gear provided on the winding shaft.

[0023] According to the above printer, the rotational force of the wheel can be reliably transmitted to the winding shaft.

[0024] In the above printer, the rotating shaft is rotatably supported by a supporting ring having a protruding height that is 2 to 3 times the thickness of the sheet metal member.

[0025] According to the above printer, the bearing for rotatably supporting the rotating shaft can be omitted, and the axial thickness of the rotational force generating mechanism can be reduced.

[0026] In the above-mentioned printer, the retaining groove is annular.

[0027] According to the above printer, the tension spring can be easily wound. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a perspective view showing the appearance of the printer according to the embodiment.

[0029] Figure 2 Yes means Figure 1 A three-dimensional view of a printer with its cover opened.

[0030] Figure 3 It means in Figure 1 A perspective view of a label paper roll used in a printer.

[0031] Figure 4 Yes means Figure 1 A schematic diagram of the internal structure of the printer.

[0032] Figure 5 It means Figure 4 A sectional stereoscopic view of a rotational force generating mechanism and its surrounding structure connected to one end of the winding shaft.

[0033] Figure 6 is from Figure 5 Observe the drive in the direction of arrow F6 Figure 4 A top view of the drive mechanism of the winding shaft.

[0034] Figure 7 Observed from the direction of arrow F7 Figure 5 Side view of the structure.

[0035] Figure 8 Observed from the direction of arrow F8 Figure 7 Rear view of the structure.

[0036] Description of Reference Numerals

[0037] 2…base, 4…cover, 11…label paper, 18…feeding shaft, 19…winding shaft, 20…rotating shaft, 21…paper pressing roller, 22…one-way bearing, 23…print head, 24…gear, 25…ribbon, 26…supply roller, 27…recovery roller, 29…sheet metal, 291…support ring, 292…hook, 30…rotational force generating mechanism, 31…one-way bearing, 32…rotating member, 321…hook, 322…retaining groove, 33…tension spring, 40…driving mechanism, 41…motor, 100…label printer. DETAILED DESCRIPTION

[0038] Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings.

[0039] like Figure 1 and Figure 2 As shown, the label printer 100 (hereinafter referred to as the printer 100) has a base 2 and a cover 4. The base 2 constitutes the lower housing of the printer 100, and the cover 4 constitutes the upper housing of the printer. The cover 4 is connected to the base 2 by a hinge (not shown) provided at the rear end side. Figure 1 The closed position shown and Figure 2 In the following description, the cover 4 is configured in the closed position. Figure 1 In the illustrated state, the ejection port 9 side of the printer 100 is defined as the front side, and each of the up, down, left, and right directions of the printer 100 is defined when viewed from the front side.

[0040] The base 2 is a rectangular box with an open top, and has a cutout portion 3 on the front wall for mounting a functional unit (not shown) such as a peeling unit. The base 2 has a front panel 5 mounted on the cutout portion 3 when no functional unit is mounted. Figure 1 and Figure 2 , the front panel 5 is mounted on the cutout portion 3. The printer 100 has a slit-shaped discharge port 9 between the front panel 5 of the base 2 and the cover 4 for discharging the printed label paper 11.

[0041] The cover 4 is a rectangular box with an opening at the bottom. On the front sides of the left and right side walls of the cover 4, there are respectively an opening lever 6 for opening the cover 4 and a fixing hook 16 that is actuated by the operation of the opening lever 6. When the cover 4 is arranged in the closed position, the fixing hook 16 engages with the engaged portion on the side of the base 2 to lock the cover 4 in the closed position. On the upper wall of the cover 4, there are an operation and display panel 7 and a power button 8.

[0042] like Figure 3As shown, the label paper 11 installed in the base 2 is formed by pasting a plurality of rectangular labels 13 at equal intervals on one surface of a long strip-shaped backing paper 12. The label 13 has an adhesive layer on the surface of the backing paper 12 side, and can be attached to and detached from the backing paper 12. After being peeled off from the backing paper 12, it can be pasted on other objects. The label paper roll 15 is formed by winding the label paper 11 on the paper tube 14 in a direction in which the surface of the backing paper 12 to which the label 13 is pasted faces the outside.

[0043] like Figure 2 As shown, the printer 100 has a pair of left and right paper holders 17 for mounting the label paper roll 15. The label paper roll 15 is Figure 3 The label paper roller 15 is installed between a pair of paper holders 17 in the direction shown. That is, the label paper roller 15 is installed on the printer 100 in a posture in which the surface of the label 13 side of the label paper 11 pulled out from the label paper roller 15 faces upward. Therefore, when the label paper 11 pulled out from the label paper roller 15 is conveyed to the discharge port 9, the label paper roller 15 rotates counterclockwise when viewed from the right side. The label paper 11 is an example of a print medium.

[0044] like Figure 2 and Figure 4 As shown, the printer 100 has a platen roller 21 that applies a conveying force to the label paper 11 in the positive direction of pulling the label paper 11 from the label paper roller 15. The platen roller 21 can also rotate in the opposite direction to return the label paper 11. The platen roller 21 is arranged on the front side of the base 2 adjacent to the discharge port 9. The platen roller 21 contacts and rotates with the surface opposite to the surface on which the label 13 is attached to the base paper 12 of the label paper 11. The printer 100 has a conveying path 1 for conveying the label paper 11 pulled out from the label paper roller 15. When the cover 4 is rotated to Figure 2 When the conveying path 1 is in the open position, a part of the conveying path 1 can be opened.

[0045] The printer 100 has a print head 23 that prints on each label 13 of the label paper 11 conveyed through the conveying path 1. The print head 23 is arranged on the opposite side (upper side) of the conveying path 1 relative to the platen roller 21, and is pressed toward the platen roller 21. Therefore, a conveying force can be applied from the platen roller 21 to the label paper 11 at a position where the print head 23 is pressed against the platen roller 21. The print head 23 is a structure on the cover 4 side. The cover 4 has a pressing spring (not shown) that presses the print head 23 against the platen roller 21. The platen roller 21 is an example of a conveying unit that conveys the printed medium.

[0046] The print head 23 can print by thermal transfer or by thermal sensitive printing. When printing by thermal transfer, a ribbon 25 is placed between the print head 23 and the label paper 11, and the ribbon 25 is transported at the same speed and in the same direction as the label paper 11, and the heat of the print head 23 is used to dissolve the ink of the ribbon 25 and fix it on the label 13.

[0047] like Figure 4 As shown, the printer 100 includes a supply roller 26 that winds a long ribbon 25 around a paper tube, and a recovery roller 27 that winds the used ribbon 25 that has passed through the print head 23 using the paper tube. The ribbon 25 that is tensioned between the supply roller 26 and the recovery roller 27 passes between the print head 23 and the platen roller 21 in a manner that it sequentially overlaps with a plurality of labels 13 of the label paper 11 that is transported through the transport path 1. The ribbon 25 is a ribbon that holds ink that is transferred to each label 13 of the label paper 11 by heat.

[0048] A pair of paper holders 17 ( Figure 2 ) can rotatably hold both ends of the paper tube 14 of the label paper roll 15. In the cover 4, there is a paper tube delivery shaft 18 installed on the supply roller 26 of the ribbon 25 and a paper tube winding shaft 19 installed on the recovery roller 27 ( Figure 2 The delivery shaft 18 and the winding shaft 19 extend in parallel and away from each other.

[0049] When printing each label 13 of the label paper 11, the printer 100 Figure 4 The pressing roller 21 is rotated counterclockwise to rotate the label paper 11 pulled out from the label paper roller 15 in the forward direction ( Figure 4 In addition, at this time, the printer 100 makes the winding shaft 19 equipped with the recovery roller 27 move in a certain direction. Figure 4 The printer 100 rotates clockwise in the middle and conveys the ribbon 25 at the same speed in the forward direction. In this state, the printer 100 prints on each label 13 of the label paper 11 via the print head 23 .

[0050] When the printing operation is continued, the ribbon 25 may be loose or wrinkled. It is known that such looseness and wrinkles of the ribbon 25 can be eliminated by feeding back the ribbon 25. When feeding back the ribbon 25, the print head 23 is moved to a retreat position away from the platen roller 21 upward, and the delivery shaft 18 on which the supply roller 26 is mounted is moved upward. Figure 4 The ribbon 25 is then rotated in the counterclockwise direction to return the ribbon 25. Thus, the used ribbon 25 is pulled out from the recovery roller 27, and the recovery roller 27 is rotated in the counterclockwise direction to return the ribbon 25. Figure 4 Rotate counterclockwise.

[0051] When the ribbon 25 is returned, the rotation of the delivery shaft 18 is stopped. Figure 4 The supply roller 26 rotates counterclockwise during the rotation of the ribbon 25, so the recovery roller 27 continues to rotate counterclockwise due to inertia. In this case, it is possible that the ribbon 25 will be newly slack between the supply roller 26 that stops rotating and the recovery roller 27 that continues to rotate. The larger the diameter (weight) of the recovery roller 27, the greater the slack at this time.

[0052] The printer 100 of this embodiment has a rotational force generating mechanism 30 that generates a rotational force in the direction of winding the ribbon 25 relative to the winding shaft 19 of the recovery roller 27 during the return in order to prevent the ribbon 25 from being loosened during the return. Figures 5 to 8 , the rotational force generating mechanism 30 and its peripheral structure are described.

[0053] Figure 5 is a cross-sectional perspective view showing the rotational force generating mechanism 30 and its peripheral structure, Figure 6 From the left side of the printer 100 ( Figure 5 A top view of the drive mechanism 40 for driving the winding shaft 19 of the recovery roller 27 is observed in the direction of the arrow F6. Figure 7 Observed from the direction of arrow F7 Figure 5 A side view of the structure, Figure 8 is from Figure 7 The rear view of the rotational force generating mechanism 30 is viewed in the direction of arrow F8 (the rear of the printer 100).

[0054] To facilitate understanding, in each figure, arrow A indicates the rotation direction of the feed shaft 18 and the winding shaft 19 and the travel direction of the ribbon 25 when the ribbon 25 is conveyed in the positive direction, and arrow B indicates the rotation direction of the feed shaft 18 and the winding shaft 19 and the travel direction of the ribbon 25 when the ribbon 25 is returned.

[0055] like Figure 5 As shown, the printer 100 has a wheel 10 for coaxially connecting one end (left end) of the winding shaft 19. The wheel 10 is rotatably accommodated in a recess 281 of a frame 28 fixedly disposed on the left side of the cover 4. When the recovery roller 27 is mounted on the printer 100, the wheel 10 receives and engages with a bevel gear (not shown) disposed on the left end of the winding shaft 19 of the recovery roller 27. The installation is easy and the transmission of the rotational force becomes reliable. Therefore, the winding shaft 19 rotates in the direction in which the wheel 10 rotates. The wheel 10 coaxially and integrally has a rotating shaft 20 extending through the bottom of the recess 281. That is, the rotating shaft 20 becomes an axis coaxially and integrally connected to the winding shaft 19.

[0056] The rotating shaft 20 passes through the bottom of the recess 281 of the frame 28 and extends to the left. The left end of the rotating shaft 20 is rotatably supported by a rotating member 32 and a one-way bearing 31 described later, and the rotating member 32 is rotatably mounted on a sheet metal member 29 fixedly provided on the cover 4 at a position away from the left side of the frame 28. The sheet metal member 29 has a support ring 291 whose protruding height is 2 to 3 times the thickness of the plate. The support ring 291 functions as a bearing that rotatably supports the left end of the rotating member 32. Therefore, the bearing that rotatably supports the left end of the rotating shaft 20 can be omitted, and the axial thickness of the rotational force generating mechanism 30 can be reduced.

[0057] The rotating shaft 20 is coaxially surrounded by two one-way bearings 22 and 31. The one-way bearing 22 on the side close to the wheel 10 is installed between the gear 24 and the rotating shaft 20. The other one-way bearing 31 on the sheet metal 29 side is a component of the rotational force generating mechanism 30, and is installed between the rotating member 32 of the rotational force generating mechanism 30 and the rotating shaft 20. The one-way bearing 31 of the rotational force generating mechanism 30 is adjacently arranged on the side of the one-way bearing 22 opposite to the wheel 10.

[0058] The one-way bearing 22 includes an inner sleeve fixed on the rotating shaft 20 and an outer sleeve installed on the outer side of the inner sleeve through a plug. Figure 6 The driving mechanism 40 shown in the figure transmits the rotational force to the rotating shaft 20 when the gear 24 rotates in the positive direction, and allows the rotating shaft 20 to rotate in the reverse direction when the gear 24 is stopped. That is, when the one-way bearing 22 conveys the ribbon 25 in the positive direction, the motor 41 ( Figure 6 ) is transmitted to the rotating shaft 20, so that the recovery roller 27 rotates in the direction of winding the ribbon 25. In addition, when the motor 41 (gear 24) is stopped, when the ribbon 25 is returned, the one-way bearing 22 functions to allow the recovery roller 27 (rotating shaft 20) to rotate in the opposite direction (idling).

[0059] The one-way bearing 31 of the rotational force generating mechanism 30 has an inner sheath fixed to the rotating shaft 20 and an outer sheath mounted on the outer side of the inner sheath via a plug. The one-way bearing 31 transmits the rotational force of the rotating shaft 20 to the rotating member 32 when the rotating shaft 20 rotates in the reverse direction by the return of the ribbon 25, and allows the rotating shaft 20 to rotate idly relative to the rotating member 32 when the ribbon 25 is fed in the forward direction.

[0060] like Figure 6 As shown, the drive mechanism 40 for rotating the gear 24 includes a motor 41 , first to fourth gears 43 to 46 sequentially meshing with a gear 42 fixed to the rotating shaft of the motor 41 , and a fifth gear 47 with a torque limiter disposed between the fourth gear 46 and the gear 24 .

[0061] like Figure 7 and Figure 8 As shown, the rotational force generating mechanism 30 has a tension spring 33 whose lower end is fixed to the sheet metal 29 and whose upper end is fixed to the rotating member 32. The tension spring 33 is an example of an elastic member that elastically deforms during the return. The sheet metal 29 has a hook 292, and the hook 292 is hooked on the lower end 331 of the tension spring 33. The rotating member 32 is provided with a hook 321 protruding from its outer peripheral surface for hooking the upper end 332 of the tension spring 33. Figure 7 and Figure 8 This shows an initial state where the tension spring 33 is not elastically deformed.

[0062] The rotating member 32 has an annular retaining groove 322 for winding the stretched tension spring 33. The hook 321 protrudes from the bottom of the retaining groove 322. The sheet metal 29 is arranged on the left side of the retaining groove 322. The sheet metal 29 functions as a pressure plate for preventing the tension spring 33 wound on the retaining groove 322 from being separated from the retaining groove 322 due to its restoring force.

[0063] When the rotating shaft 20 is in the return Figure 7 When the rotating member 32 rotates clockwise, Figure 7 The tension spring 33 is stretched and wound around the retaining groove 322. When the tension spring 33 is stretched, its restoring force acts on the rotating member 32 to rotate clockwise. Figure 7 That is, when the ribbon 25 is returned, tension is always applied to the ribbon 25 between the print head 23 and the recovery roller 27. In other words, when the ribbon 25 is returned, the tension spring 33 is in a state of rotating counterclockwise. Figure 7 A counterclockwise rotational force is applied to the rotating shaft 20, and a rotational force in the direction of winding the ribbon 25 is applied to the winding shaft 19.

[0064] That is, when the rotational force generating mechanism 30 of the present embodiment is used, when the reverse rotation of the delivery shaft 18 is stopped and the rotation of the supply roller 26 is stopped at the end of the return of the ribbon 25, the recovery roller 27 will not continue to rotate in the reverse direction due to the inertial force, and thus will not generate the above-mentioned Figure 6 The slack of the ink ribbon 25 is shown by the dotted line 251. Therefore, according to this embodiment, the wrinkles of the ink ribbon 25 are eliminated by feeding back the ink ribbon 25, and no new slack of the ink ribbon 25 is generated after feeding back, so that the printing quality can be improved.

[0065] The embodiments of the present invention are described above, but the embodiments are presented as examples and are not intended to limit the scope of the invention. The embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the scope of the invention. The embodiments and their modifications are included in the scope or spirit of the invention, and are included in the invention described in the claims and their equivalents.

Claims

1. A printer comprising: A delivery shaft capable of rotatably holding a supply roller wound with a ribbon; a winding shaft capable of rotatably holding a recovery roller that winds the ribbon fed from the supply roller; a conveying section for conveying a printed medium along the ribbon moving from the supply roller to the recovery roller; A print head, which prints by bringing the ink ribbon into contact with the printed medium conveyed by the conveying unit; as well as The rotational force generating mechanism generates a rotational force in a direction in which the ink ribbon is wound around the winding shaft when the ink ribbon is fed back by rotating the feed shaft in a direction opposite to the feed direction of the ink ribbon to move the ink ribbon in a reverse direction.

2. The printer according to claim 1, wherein: The rotational force generating mechanism comprises: A one-way bearing having a rotating member which rotates idly when the winding shaft rotates in the winding direction and rotates integrally with the winding shaft during the return in which the winding shaft rotates in a direction opposite to the winding direction; as well as The elastic member is elastically deformed by the rotation of the rotating member in the opposite direction, and causes the rotating member to rotate in the winding direction by its restoring force.

3. The printer according to claim 2, wherein: Also available: The elastic member is a tension spring having one end fixed to the rotating member, being stretched by the rotating member rotating in the opposite direction and being wound around the rotating member.

4. The printer according to claim 3, wherein: Also available: A pressing plate is fixed to the rotating member and together with the rotating member, forms a retaining groove for restricting the movement of the tension spring and winding it.

5. The printer according to claim 4, wherein: The other end of the tension spring is fixed on the pressure plate.

6. The printer according to claim 1, wherein: The rotational force generating mechanism comprises: a one-way bearing for allowing the rotating member to idle when the winding shaft rotates in the winding direction and for transmitting the rotational power of the winding shaft to the rotating member when the winding shaft rotates in the opposite direction to the winding direction during the return; as well as The elastic member applies a rotational force in the winding direction to the winding shaft during the return.

7. The printer according to claim 1, wherein: Also available: a wheel for connecting to the winding shaft; and A rotating shaft passes through the wheel and is coaxial with and integrally connected to the winding shaft.

8. The printer according to claim 7, wherein: The wheel receives and meshes with a bevel-toothed gear disposed on the winding shaft.

9. The printer according to claim 8, wherein: The rotating shaft is rotatably supported by a supporting ring having a protruding height that is 2 to 3 times the thickness of the sheet metal member.

10. The printer according to claim 4, wherein: The retaining groove is annular.

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