Transmission mechanism of printer and thermal transfer printer

Abstract

The invention provides a transmission mechanism of a printer and a thermal transfer printer, and belongs to the technical field of printing equipment. The transmission mechanism of the printer comprises a driving assembly and two one-way driving shaft assemblies. Each one-way driving shaft assembly comprises a thermal transfer ribbon shaft and a clutch assembly which is in transmission connection with the driving assembly and the thermal transfer ribbon shaft; the driving assembly drives the thermal transfer ribbon shafts to rotate in one direction through the clutch assembly, and the rotation directions of the two thermal transfer ribbon shafts are opposite. When the driving assembly rotates in one direction, one clutch assembly is connected with the corresponding thermal transfer ribbon shaft and drives the thermal transfer ribbon shaft to rotate, and the other clutch assembly is separated from the other thermal transfer ribbon shaft. The one-way driving characteristic ensures that a user can return the thermal transfer ribbon easily through the reversing driving assembly, position adjustment or unused thermal transfer ribbon rewinding is facilitated, waste of the thermal transfer ribbon is avoided, the utilization rate of the thermal transfer ribbon is improved, and flexibility and practicability are enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of printing equipment, and in particular to a transmission mechanism of a printer and a thermal transfer printer. Background Art

[0002] In printing equipment, especially thermal transfer printers, carbon ribbon is a commonly used consumable material. The role of the carbon ribbon is to transfer ink to the print medium during the printing process. However, the carbon ribbon can only move forward and cannot be retracted, resulting in the waste of the carbon ribbon. How to efficiently retract the carbon ribbon while ensuring the continuity and stability of printing has become an urgent problem to be solved. Summary of the invention

[0003] In view of the above problems, the present invention aims to provide a transmission mechanism of a printer and a thermal transfer printer that allow a reverse driving assembly to realize a carbon ribbon return function.

[0004] In a first aspect, a transmission mechanism of a printer is provided, comprising: a driving assembly and two unidirectional driving shaft assemblies;

[0005] Each of the one-way drive shaft assemblies comprises a carbon ribbon shaft and a clutch assembly that is transmission-connected to the drive assembly and the carbon ribbon shaft;

[0006] The driving assembly drives the carbon ribbon shaft to rotate in one direction through the clutch assembly, and the rotation directions of the two carbon ribbon shafts are opposite;

[0007] When the driving assembly rotates in one direction, one of the clutch assemblies engages with the corresponding carbon ribbon shaft and drives the carbon ribbon shaft to rotate, and the other clutch assembly disengages from the other carbon ribbon shaft.

[0008] Further, the clutch assembly includes a reset structure and a ratchet wheel and a pawl that mesh with each other;

[0009] The ratchet teeth of the two ratchets in the two clutch assemblies are oriented in opposite directions;

[0010] The reset structure is arranged on a side of the ratchet wheel away from the pawl;

[0011] The ratchet is drivingly connected to the driving assembly, and the pawl is drivingly connected to the carbon ribbon shaft;

[0012] The driving assembly drives the carbon ribbon shaft to rotate through the cooperation of the ratchet wheel and the pawl.

[0013] Furthermore, two adjacent edges of each ratchet tooth of each ratchet wheel are respectively a vertical edge and an inclined edge, and the inclined edges corresponding to the two ratchets are in opposite directions.

[0014] Furthermore, the reset structure is a spring, one end of the spring abuts against the abutment structure of the printer, and the other end abuts against a side of the ratchet wheel away from the pawl.

[0015] Furthermore, the clutch assembly also includes a sleeve sleeved on the carbon ribbon shaft, the pawl is arranged on the sleeve, and the sleeve is drivingly connected to the carbon ribbon shaft.

[0016] Furthermore, the clutch assembly also includes a fixed shaft, the shaft sleeve and the carbon ribbon shaft sleeve are arranged on the fixed shaft, and the fixed shaft is provided with a limiting structure to limit the shaft sleeve or the carbon ribbon shaft from moving in the axial direction.

[0017] Furthermore, the limiting structure is a flange arranged on the periphery of the fixed shaft.

[0018] Further, the driving assembly includes a driving motor and a gear set, and the gear set includes an input gear and two output gears;

[0019] The output end of the driving motor is coaxially and fixedly connected to the input gear in the gear set;

[0020] The two output gears are drivingly connected to the two clutch assemblies respectively.

[0021] Furthermore, the side surface of the ratchet wheel is provided with engaging teeth, and the engaging teeth are engaged with the output gear.

[0022] In a second aspect, a thermal transfer printer is provided, comprising the transmission mechanism of the printer as described in the above technical solution.

[0023] The embodiments of the present invention have the following advantages or beneficial effects:

[0024] The driving component selectively drives a ribbon shaft to rotate through two clutch components. When rotating in the first direction, it drives a ribbon shaft (i.e., the recovery shaft) to rotate to achieve normal printing; when rotating in the second direction, it drives another ribbon shaft (i.e., the delivery shaft) to rotate to achieve the retraction of the ribbon. This one-way driving feature ensures that the ribbon can only be retracted and delivered in the preset direction. During use, the normal use and retraction of the ribbon can be achieved by only rotating the driving component forward and backward, and it is used to rewind the unused ribbon to the initial position, avoiding the waste of the ribbon, thereby improving the utilization rate of the ribbon. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings.

[0026] Figure 1 is a schematic diagram of a transmission mechanism of a printer according to an exemplary embodiment. Figure 1(with partial cutaway view);

[0027] Figure 2 is a schematic diagram of a transmission mechanism of a printer according to an exemplary embodiment. Figure 2 ;

[0028] Figure 3 is a first-view stereoscopic diagram of a transmission mechanism of a printer according to an exemplary embodiment;

[0029] Figure 4 is a second perspective perspective view of a transmission mechanism of a printer according to an exemplary embodiment;

[0030] Figure 5 yes Figure 1 Enlarged view of part D in .

[0031] The reference numerals are described as follows:

[0032] 1. driving assembly, 2. one-way driving shaft assembly, 3. engaging teeth, 4. abutting structure;

[0033] 11. driving motor, 12. gear set;

[0034] 21. Carbon ribbon shaft, 22. Clutch assembly;

[0035] 221. reset structure; 222. ratchet; 223. pawl; 224. bushing; 225. fixed shaft; 226. flange. DETAILED DESCRIPTION

[0036] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present invention will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted.

[0037] The terms "a", "an", "the", and "said" are used to indicate the presence of one or more elements / components / etc.; the terms "comprising" and "having" are used to express an open-ended inclusive meaning and mean that additional elements / components / etc. may be present in addition to the listed elements / components / etc.

[0038] Figure 1 is a schematic diagram of a transmission mechanism of a printer according to an exemplary embodiment. Figure 1 (with partial cutaway view); Figure 2 is a schematic diagram of a transmission mechanism of a printer according to an exemplary embodiment. Figure 2; Figure 3 is a first-view stereoscopic diagram of a transmission mechanism of a printer according to an exemplary embodiment; Figure 4 is a second perspective perspective view of a transmission mechanism of a printer according to an exemplary embodiment; Figure 5 yes Figure 1 The above schematic diagram is only for showing the structural relationship related to the invention point and is not the actual scale of the actual product.

[0039] like Figures 1 to 5 As shown, a transmission mechanism of a printer in an embodiment of the present invention comprises: a driving assembly 1 and two unidirectional driving shaft assemblies 2; each unidirectional driving shaft assembly 2 comprises a carbon ribbon shaft 21 and a clutch assembly 22 which is transmission-connected to the driving assembly 1 and the carbon ribbon shaft 21; the driving assembly 1 drives the carbon ribbon shaft 21 to rotate unidirectionally through the clutch assembly 22, and the rotation directions of the two carbon ribbon shafts 21 are opposite; when the driving assembly 1 rotates in one direction, one of the clutch assemblies 22 engages with the corresponding carbon ribbon shaft 21 and drives the carbon ribbon shaft 21 to rotate, and the other clutch assembly 22 disengages from the other carbon ribbon shaft 21.

[0040] Drive assembly 1 is the power source of the entire transmission system and is responsible for providing rotational motion.

[0041] Each one-way drive shaft assembly 2 includes a ribbon shaft 21 and a clutch assembly 22. The two clutch assemblies 22 ensure that the respective ribbon shafts 21 can only rotate in a predetermined direction.

[0042] The clutch assembly 22 connects the driving assembly 1 and the carbon ribbon shaft 21 to control the power transmission between the two. According to the rotation direction of the driving assembly 1, the clutch assembly 22 can selectively engage or disengage with the corresponding carbon ribbon shaft.

[0043] Due to the design of the two unidirectional drive shaft assemblies 2, when the drive assembly 1 rotates in one direction, it will only rotate one of the ribbon shafts 21, while the other ribbon shaft 21 remains stationary. This is because each clutch assembly 22 has a unidirectional transmission characteristic, that is, it only allows torque to be transmitted in its set direction.

[0044] It should be noted that the carbon ribbon shaft includes a carbon ribbon recovery shaft and a carbon ribbon delivery shaft. The two ends of the carbon ribbon are respectively wound on the carbon ribbon recovery roll and the carbon ribbon delivery roll. The carbon ribbon recovery roll is sleeved on the carbon ribbon recovery shaft, and the carbon ribbon delivery roll is sleeved on the carbon ribbon delivery shaft.

[0045] During the printing process, the driving component 1 rotates in the forward direction, and drives the corresponding carbon ribbon shaft 21 (carbon ribbon recovery shaft) to rotate through one of the clutch components 22, drives the carbon ribbon recovery roll to rotate, and pulls the carbon ribbon delivery roll to rotate in the same direction through the carbon ribbon. At this time, since the other carbon ribbon shaft 21 (carbon ribbon delivery shaft) is disengaged from the corresponding clutch component 22, when the carbon ribbon delivery roll rotates, the corresponding carbon ribbon shaft 21 (carbon ribbon delivery shaft) rotates together, and will not drive the corresponding clutch component 22 to rotate.

[0046] During the process of ribbon retraction, the driving component 1 rotates in the reverse direction, and drives the corresponding ribbon shaft 21 (ribbon dispensing shaft) to rotate in the reverse direction through another clutch component 22, thereby driving the dispensing roll to rotate until the ribbon is recovered. It should be noted that if the ribbon between the ribbon recovery roll and the ribbon dispensing roll is in a taut state in the initial state, the retraction process is the reverse movement of the printing process, which will drive the ribbon recovery roll to rotate in the reverse direction; if the ribbon between the ribbon recovery roll and the ribbon dispensing roll is not in a taut state in the initial state, the ribbon recovery roll may not rotate during the retraction process until the ribbon between the ribbon recovery roll and the ribbon dispensing roll is in a taut state.

[0047] The forward and reverse rotations of the driving assembly 1 are for the convenience of explanation and do not limit the actual operation process. Corresponding adjustments can be made in practice.

[0048] In one embodiment, the drive assembly 1 includes a drive motor 11 and a gear set 12; the output end of the drive motor 11 is coaxially fixedly connected to the input gear in the gear set 12; the gear set 12 has two output gears, and the two output gears are respectively connected to two unidirectional drive shaft assemblies 2.

[0049] An idler gear is also connected between the input gear and the two output gears to ensure that the two output gears rotate in the same direction.

[0050] The driving motor 11 serves as the power source of the entire system, and is responsible for providing the necessary torque to drive the dispensing and retracting operations of the carbon ribbon.

[0051] Gear set 12 is capable of changing the speed of rotation. By meshing gears with different numbers of teeth, a deceleration or acceleration effect can be achieved. According to the principle of power conservation, when gear set 12 changes speed, it also changes torque at the same time. The greater the reduction ratio, the greater the output torque; and vice versa. This allows for greater force or finer speed control where needed.

[0052] There are many types of drive motors 11, which can be divided into many types according to different classification standards (such as working principle, power supply type, application field, etc.). The following are several common types of drive motors 1111 and their characteristics:

[0053] DC motors have large starting torque, good speed regulation performance, and are easy to control. They require commutators and brushes, are more complicated to maintain, and have a relatively short lifespan. They are suitable for applications that require frequent starting, stopping, or speed regulation.

[0054] Synchronous motors rotate synchronously with the frequency of the AC power supply and are suitable for equipment that runs at a constant speed. They have high efficiency and good power factor.

[0055] Asynchronous motors, the most commonly used type of AC motors, are simple in structure, rugged and durable. They are low in cost, highly reliable and require little maintenance.

[0056] Permanent magnet synchronous motor uses permanent magnet material as excitation source, which has high efficiency and power density. It is energy-efficient, has fast response speed and good dynamic performance.

[0057] Brushless DC motor combines the advantages of DC motor and AC motor, eliminating brushes and commutator. It has high efficiency, low noise, long life and easy maintenance.

[0058] In one embodiment, the clutch assembly 22 includes a reset structure 221 and a ratchet 222 and a pawl 223 that mesh with each other; the ratchet teeth of the two ratchets 222 in the two clutch assemblies 22 are oriented in opposite directions; the reset structure 221 is arranged on the side of the ratchet 222 away from the pawl 223; the ratchet 222 is drivingly connected to the driving assembly 1, and the pawl 223 is drivingly connected to the carbon ribbon shaft 21; the driving assembly 1 drives the carbon ribbon shaft 21 to rotate through the cooperation of the ratchet 222 and the pawl 223.

[0059] The ratchet 222 in each one-way drive shaft assembly 2 is directly connected to the drive assembly 1 (ie, the output gear of the gear set 12). Specifically, the side of the ratchet 222 is provided with a meshing tooth 3, and the meshing tooth 3 meshes with the output gear.

[0060] The pawl 223 is connected to the ribbon shaft 21 and meshes with the ratchet 222. The design of the ratchet 222 and the pawl 223 allows the ratchet 222 to drive the pawl 223 to rotate freely in one direction, while in the opposite direction, the pawl 223 will be disengaged from the ratchet 222 and the ratchet 222 will rotate idly.

[0061] The reset structure 221 is located on the side of the ratchet 222 away from the pawl 223, and is used to provide a reset force for the ratchet 222 to re-engage with the pawl 223 each time the ratchet 222 and the pawl 223 are disengaged. This can be an elastic element such as a spring to ensure that the pawl 223 is always aligned with the ratchet teeth.

[0062] The ratchet teeth on the ratchets 222 in the two clutch assemblies 22 are oriented in opposite directions to ensure that when the driving assembly 1 rotates in one direction, one of the ratchets 222 can drive its corresponding ribbon shaft 21 to rotate, while the other ratchet 222 cannot transmit power to the ribbon shaft 21 due to the action of the pawl 223, but the ribbon shaft can rotate with the ratchet, and vice versa.

[0063] The working process is as follows:

[0064] The driving motor 11 starts to rotate, and transmits the rotational motion to the two output gears through the gear set 12. Due to the presence of the idler gear, the two output gears rotate in the same direction.

[0065] During normal printing, the drive assembly 1 (output gear) rotates clockwise:

[0066] A ratchet wheel 222 (ratchet wheel 222B) is engaged with a corresponding pawl 223 (assuming it is pawl 223B), and drives the carbon ribbon shaft 21 connected to the pawl 223B to transfer synchronously, that is, the carbon ribbon recovery roll is driven to rotate through the cooperation of the ratchet wheel 222B and the pawl 223B;

[0067] Another ratchet 222 (assuming it is ratchet 222A) is disengaged from the corresponding pawl 223 (assuming it is pawl 223A), and the ratchet 222A is idling. The pawl 223A cannot drive the corresponding carbon ribbon shaft 21 to rotate, but the carbon ribbon recovery roll can pull the carbon ribbon dispensing roll to rotate through the carbon ribbon, which is equivalent to the rotation of the ratchet 222A, thereby realizing the dispensing of the carbon ribbon.

[0068] When the ribbon needs to be retracted, the drive assembly 1 rotates counterclockwise:

[0069] Another ratchet 222A is engaged with the pawl 223A, and drives the carbon ribbon shaft 21 connected to the pawl 223A to transfer synchronously, that is, the carbon ribbon dispensing roll is driven to rotate through the cooperation of the ratchet 222A and the pawl 223A.

[0070] The ratchet 222B is disengaged from the corresponding pawl 223B, and the ratchet 222B rotates idly and cannot drive the corresponding ribbon shaft 21 to rotate, but the ribbon recovery roll can be equivalent to the rotation of the ratchet 222B. As for whether it rotates, it needs to be determined by the state in which it is located. It will not be repeated here, and the details can be referred to the previous description.

[0071] The clockwise and counterclockwise rotation of the driving assembly 1 is for the convenience of explanation and does not limit the actual operation process.

[0072] Each time the driving assembly 1 changes its rotation direction or stops, the reset structure 221 acts on the ratchet 222 to disengage from the pawl 223, reset the ratchet 222, and reengage with the pawl 223, so as to correctly engage or disengage when the driving assembly 1 rotates next time. Specifically, the reset structure 221 can be a spring, a spring, or a magnetic reset structure, which is not limited here.

[0073] In one embodiment, two adjacent edges of each ratchet tooth of each ratchet wheel 222 are respectively a vertical edge and an inclined edge, and the inclined edges corresponding to the two ratchet wheels 222 are in opposite directions.

[0074] The design of the vertical edge enables the pawl 223 to be tightly engaged with the ratchet 222, ensuring that the contact surface between the two is maximized. When the drive assembly 1 rotates in a predetermined direction, the pawl teeth can accurately fit into the vertical edge of the ratchet teeth, providing a stable engagement.

[0075] The design of the vertical edge allows the force transmitted to the ratchet 222 to be almost completely concentrated in the radial direction, rather than being dispersed in the axial direction. This helps to reduce unnecessary axial loads, protect bearings and other axial stop devices from being affected by additional stress, and extend their service life.

[0076] Since the vertical edge can effectively transmit the torque of the drive assembly 1 to the carbon ribbon shaft 21, energy loss is reduced and the power transmission efficiency of the entire system is improved. This means that more input energy is converted into useful mechanical work rather than wasted on friction or other ineffective motion.

[0077] The existence of the inclined edge enables the pawl 223 to easily slide over the ratchet teeth when not in operation, avoiding forced hard collision. This design not only reduces wear, but also reduces noise and vibration, and improves the smooth operation of the system.

[0078] When the drive assembly 1 rotates in the opposite direction, the inclined edge allows the pawl 223 to slide smoothly without engaging with the ratchet wheel 222, thereby realizing the one-way clutch function. This design ensures that the corresponding ribbon assembly is activated only when needed, improving the reliability and operating accuracy of the system.

[0079] The combination of vertical and inclined sides ensures high stability and reliability during operation. Whether starting, stopping or switching operating modes, the system can maintain good performance.

[0080] By optimizing the shape of the ratchet teeth, the need for complex control logic is reduced and the overall mechanical structure is simplified. This not only reduces manufacturing costs but also improves the maintainability of the system.

[0081] Users can enjoy a smoother operating experience without having to worry about freezes or malfunctions caused by design flaws. In addition, low noise and smooth operation also improve user satisfaction.

[0082] In one embodiment, the reset structure 221 is a spring, one end of the spring abuts against the abutment structure 4 of the printer, and the other end abuts against a side of the ratchet 222 away from the pawl 223 .

[0083] The function of the spring is to provide the necessary reset force every time the driving assembly 1 changes the rotation direction or stops, so that the ratchet 222 returns to the initial position of the engagement with the pawl 223. The design of the spring needs to consider appropriate elastic force and preload force to ensure that the ratchet 222 can be reset smoothly and that the pawl 223 and the ratchet 222 do not collide hard due to excessive elastic force. Specifically, the abutment structure 4 can be a support plate, or abutment with the inner shell of the printer, that is, one end of the spring directly abuts with the inner shell of the printer.

[0084] When the abutment structure 4 is a support plate, the support plate serves as a mounting base for the spring, and the support plate is usually fixed to a printer frame or other stable structure to ensure that the spring can expand and contract within a controlled range without offset or misalignment. The support plate must be strong enough to withstand the force applied by the spring and ensure that the spring will not fatigue or fail during long-term use.

[0085] In one embodiment, the clutch assembly 22 further includes a sleeve 224 sleeved on the ribbon shaft 21, the pawl 223 is disposed on the sleeve 224, and the sleeve 224 is drivingly connected to the ribbon shaft 21. In another embodiment, it further includes a fixed shaft 225, the sleeve 224 and the ribbon shaft 21 are sleeved on the fixed shaft 225, and the fixed shaft 225 is provided with a limiting structure to limit the sleeve 224 or the ribbon shaft 21 from moving in the axial direction.

[0086] The fixed shaft 225 is vertically and fixedly connected to the support plate, serving as a core support member of the entire clutch assembly 22. The fixed shaft 225 provides a basis for installing and positioning other components, ensuring that all components can work stably.

[0087] The shaft sleeve 224 is sleeved on the ribbon shaft 21 and is connected to the ribbon shaft 21 in a driving manner (such as a keyway or a spline). This means that when the shaft sleeve 224 rotates, it drives the ribbon shaft 21 to rotate synchronously.

[0088] The pawl 223 is disposed on the shaft sleeve 224 and fixedly connected to the shaft sleeve 224 , and may also be provided in the form of a keyway or a spline.

[0089] The ratchet 222 is rotatably connected to the fixed shaft 225, allowing it to rotate freely.

[0090] The spring is disposed on the fixed shaft 225 , one end of the spring is connected to the support plate, and the other end of the spring is connected to a side of the ratchet 222 away from the pawl 223 .

[0091] The limiting structure is used to limit the axial movement of the sleeve 224 or the ribbon shaft 21, ensuring that they can only rotate around the fixed shaft 225 without axial sliding. The limiting structure can be a mechanical element such as a retaining spring, a washer, a shoulder, etc. These elements are usually installed at both ends or in the middle of the fixed shaft 225 to form an effective axial block.

[0092] The retaining ring is installed in the groove of the fixed shaft 225 to play an axial limiting role. It is a simple and effective limiting method with low cost and easy installation.

[0093] The washer is placed at the end or middle of the fixed shaft 225 and is tightened by a nut or other fasteners to prevent the sleeve 224 or the ribbon shaft 21 from sliding in the axial direction.

[0094] The shoulder directly processes a stepped flange 226 on the fixed shaft 225 to prevent the axial movement of the sleeve 224 or the ribbon shaft 21. This design does not require additional parts, but requires precision machining during the manufacturing process.

[0095] By integrating the shaft sleeve 224, the pawl 223, the ratchet 222 and the reset structure 221 on a fixed shaft 225, the entire clutch assembly 22 becomes more compact and saves space.

[0096] The two ribbon shafts 21 are the recovery shaft and the dispensing shaft, respectively, and the one-way rotation is realized through the clutch assembly 22 (including the ratchet 222, the pawl 223 and the reset structure 221), and ensures that the ribbon can be properly wound and retracted during the printing process. The following is the detailed workflow of this system during normal printing and retracting operations:

[0097] Normal printing process

[0098] The driving motor 11 starts to rotate clockwise (assumed), and transmits the rotational motion to the two output gears through the gear set 12.

[0099] The ratchet 222 (assuming it is ratchet 222A) connected to the recovery shaft is engaged with the corresponding pawl 223 (pawl 223A). At this time, the pawl 223A is embedded in the ratchet teeth, and as the drive assembly 1 rotates, the ratchet 222A drives the recovery shaft to rotate clockwise.

[0100] The rotation of the recovery shaft will pull the dispensing shaft to rotate synchronously through the carbon ribbon, but the ratchet 222 (ratchet 222B) of the dispensing shaft is disengaged from the pawl 223 (pawl 223B), causing the ratchet 222B to idle, so that the ratchet 222B will not drive the carbon ribbon dispensing shaft to rotate.

[0101] As the reel rotates, the ribbon is gradually wound onto the reel and released from the dispenser to support the printing operation.

[0102] Whenever the driving assembly 1 stops rotating, the spring in the reset structure 221 pushes the ratchet 222B back to the starting position, ready for the next engagement.

[0103] Rollback process

[0104] The drive motor 11 starts to rotate counterclockwise (relative to the direction during normal printing).

[0105] The ratchet 222 (ratchet 222B) connected to the dispensing shaft is engaged with the corresponding pawl 223 (pawl 223B). At this time, the pawl 223B is embedded in the ratchet teeth, and as the drive assembly 1 rotates, the ratchet 222B drives the dispensing shaft to rotate clockwise.

[0106] The rotation of the dispensing shaft will pull the recovery shaft to rotate synchronously through the carbon ribbon, but the recovery shaft will idle because its ratchet 222 (ratchet 222A) is disengaged from the pawl 223 (pawl 223A), so the ratchet 222A will not drive the carbon ribbon recovery shaft to rotate.

[0107] As the dispensing shaft rotates clockwise, the carbon ribbon is gradually unwound from the recovery shaft and rewound onto the dispensing shaft, thus realizing the retraction operation of the carbon ribbon.

[0108] Whenever the driving assembly 1 stops rotating, the spring in the reset structure 221 pushes the ratchet 222A back to the starting position, ready for the next engagement.

[0109] The present solution also protects a thermal transfer printer, including a transmission mechanism of the printer as described above, wherein the transmission mechanism is disposed in a housing of the printer.

[0110] In the embodiments of the present invention, the term "plurality" refers to two or more than two, unless otherwise clearly defined. The terms "installation", "connection", "fixation" and the like should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0111] In the description of the embodiments of the present invention, it needs to be understood that the directions or positional relationships indicated by the terms "upper" and "lower" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the embodiments of the present invention.

[0112] In the description of this specification, the description of the terms "one embodiment", "a preferred embodiment", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0113] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A transmission mechanism of a printer, characterized in that: include: A drive assembly (1) and two one-way drive shaft assemblies (2); Each of the one-way drive shaft components (2) comprises a carbon ribbon shaft (21) and a clutch component (22) drivingly connected to the drive component (1) and the carbon ribbon shaft (21); The driving component (1) drives the carbon ribbon shaft (21) to rotate in one direction through the clutch component (22), and the rotation directions of the two carbon ribbon shafts (21) are opposite; When the driving assembly (1) rotates in one direction, one of the clutch assemblies (22) engages with the corresponding carbon ribbon shaft (21) and drives the carbon ribbon shaft (21) to rotate, and the other clutch assembly (22) disengages from the other carbon ribbon shaft (21).

2. A transmission mechanism for a printer according to claim 1, characterized in that: The clutch assembly (22) comprises a reset structure (221) and a ratchet wheel (222) and a ratchet pawl (223) that mesh with each other; The ratchet teeth of the two ratchets (222) in the two clutch assemblies (22) are oriented in opposite directions; The reset structure (221) is arranged on a side of the ratchet wheel (222) away from the ratchet pawl (223); The ratchet wheel (222) is drivingly connected to the driving assembly (1), and the ratchet pawl (223) is drivingly connected to the carbon ribbon shaft (21); The driving assembly (1) drives the carbon ribbon shaft (21) to rotate through the cooperation between the ratchet wheel (222) and the ratchet pawl (223).

3. A transmission mechanism for a printer according to claim 2, characterized in that: The two adjacent sides of each ratchet tooth of each ratchet wheel (222) are respectively a vertical side and an inclined side, and the inclined sides corresponding to the two ratchet wheels (222) are in opposite directions.

4. A transmission mechanism for a printer according to claim 2 or 3, characterized in that: The reset structure (221) is a spring, one end of which abuts against the abutment structure (4) of the printer, and the other end of which abuts against a side of the ratchet wheel (222) away from the ratchet pawl (223).

5. A transmission mechanism for a printer according to claim 2 or 3, characterized in that: The clutch assembly (22) further comprises a shaft sleeve (224) sleeved on the carbon ribbon shaft (21), the ratchet pawl (223) is arranged on the shaft sleeve (224), and the shaft sleeve (224) is drivingly connected to the carbon ribbon shaft (21).

6. The transmission mechanism of a printer according to claim 5, characterized in that: The clutch assembly (22) further comprises a fixed shaft (225), the shaft sleeve (224) and the carbon ribbon shaft (21) being sleeved on the fixed shaft (225), and the fixed shaft (225) being provided with a limiting structure to limit the shaft sleeve (224) or the carbon ribbon shaft (21) from moving in the axial direction.

7. The transmission mechanism of a printer according to claim 6, characterized in that: The limiting structure is a flange (226) arranged on the periphery of the fixed shaft (225).

8. The transmission mechanism of a printer according to claim 1, characterized in that: The driving assembly (1) comprises a driving motor (11) and a gear set (12), wherein the gear set (12) comprises an input gear and two output gears; The output end of the driving motor (11) is coaxially and fixedly connected to the input gear in the gear set (12); The two output gears are drivingly connected to the two clutch assemblies (22) respectively.

9. The transmission mechanism of a printer according to claim 8, characterized in that: The side surface of the ratchet wheel (222) is provided with engaging teeth (3), and the engaging teeth (3) engage with the output gear.

10. A thermal transfer printer, characterized in that: A transmission mechanism comprising a printer as claimed in any one of claims 1 to 9.

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