JP5720064B1 - Ink ribbon running section structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure of an ink ribbon running section which can be attached / detached without causing the loaded ink ribbon to interfere with a thermal head when the ribbon holder cassette is mounted on a printer body and the ink ribbon is slackened. . SOLUTION: A pair of avoidance guides are arranged in a ribbon holder cassette in a position straddling a thermal head held in a printer main body, and the avoidance guides are movable carriages of slide rail rails supported by the ribbon holder cassette. The ribbon holder cassette is supported with the rack gear, and the knob on the front is turned to lock the ribbon holder cassette to the printer body by fitting the ribbon holder cassette with the key on the printer body. At the same time, by transmitting the rotation to the rack gear via a spur gear that is rotatably supported, the movable carriage is moved to move the pair of avoidance guides that are supported together to a position where they do not interfere with each other. The slack of the ink ribbon that occurs is caused by two ink guide rollers placed and supported in front of the take-up holder. In the meantime, a step roller suspended from the ink ribbon that is movable so that the path length of the ink ribbon can be changed is provided to make the slack slack. [Selection] Figure 1

Description

  This structure relates to a thermal printer.

  In recent years, it has been required to display different characters and symbols for each print target such as a shelf life, a production number, and a harvested place display on a packaged product. In such a case, generally, various information is printed by a thermal printer.

  A thermal printer is usually composed of a thermal head, an ink ribbon, and a platen roller. The thermal head has a plurality of heating elements at the end thereof, and a desired heating element generates heat when energized. The ink ribbon is wound around the supply holder and is fed from the supply holder in synchronization with the packaging film continuously fed from a packaging machine or the like, and is wound by the take-up holder after printing. ing. The platen roller is disposed so that its outer peripheral surface comes into contact with a packaging film that is continuously drawn out from a packaging machine or the like, and constitutes a print receiving portion for a thermal head and an ink ribbon (see, for example, Patent Document 1). .

  In the early days of thermal printers, the maximum print speed was about 10 inches / sec (about 250 mm / sec) using a cold-peelable ink ribbon (mainly wax ink) on a flat thermal head (for example, Patent Document 1). reference). Next, using a heat release ink ribbon (mainly resin ink or semi-resin ink) for the corner edge type thermal head, the maximum printing speed was about 20 inches / sec (about 500 mm / sec) (for example, Patent Documents). 2). As a machine that can handle a printing speed of 30 inches / sec (about 750 mm / sec), use a mechanism (see Patent Document 3) that improves the efficiency of the transmission mechanism (see Patent Document 2) (see Patent Document 4). A lightweight and compact product such as (see Patent Document 5) has come out, and there is also a thing (see Patent Document 6) that further supports high-speed printing.

  Many ink ribbons used in thermal printers have a ribbon core inner diameter of 25.4 mm (named 1 inch core), ribbon core outer diameter of 33 mm, one or two on both sides as a key groove for rotation prevention, The thickness varies depending on the type of ink, and the initial outer diameter has a width of 50 to 90 mm. In this way, the initial outer diameter and the end of the ink ribbon are considerably different, so in the initial one, the supply holder is subjected to a desired braking by a friction clutch, and the ink ribbon is pinched by a pinch roller whose outer circumference does not change, and wound. A speed higher than the feeding speed is transmitted to the take-up holder via the friction clutch, and the ink ribbon is taken up without slack, so that the friction clutch is required at two locations (see, for example, Patent Document 1). When the ink ribbon is fed out by the pinch roller, the ink surface is scratched and debris also adheres to the pinch roller, which also makes the ink surface rough, so the pinch roller must be frequently cleaned.

  In response to this, a rotary encoder that measures the speed of the ink ribbon that is fed out is provided, and by using this signal for reading control, the ink ribbon is fed out by using a friction clutch directly from the motor. Instead of non-slip driving without using a pin, pinch roller driving has become a minority (see, for example, Patent Document 2). At this time, in the production of control boards that control all the movements including the drive of the thermal printer, motor control, navigation, PPC, laser printers, and ROMs, RAMs, and peripheral functions specialized for these controls are packed. Even in applications such as real-time control where a large number of chip microcomputers are available and high speed is required, it has become possible to build a high-performance / high-function system at a lower cost. Some of these included 2ch encoder input and 2CH, making it easy to build a 2-axis servo. Some stepping motor drivers have a built-in micro-step controller that can control up to 1/16 division of the basic step angle. This means that the motor speed can be controlled only by a clock signal. This information could already be freely collected on the Internet at that time, and it seems that the operator was able to easily combine them.

  Since the feeding is replaced by non-slip drive from the motor directly to the ribbon holder, and the ribbon holder is frequently rotated forward and backward together with the ink ribbon, which is a large inertia load, the ink ribbon core and the ribbon holder are reliably rotated without slipping. The key groove that can be used is used (see, for example, Patent Document 7 and Patent Document 8).

  In such a thermal printer, a cassette-type thermal printer in which a ribbon holder for supplying an ink ribbon and winding up ink after use is configured as a ribbon holder cassette that can be attached to and detached from the printer body (see, for example, Patent Document 9). In addition, a thermal printer called an intermittent machine that performs a printing operation while moving a thermal head needs to perform a printing operation while suppressing slack caused by a change in the path length of the ink ribbon (for example, a patent) (Refer to Fig. 9 in Document 3 and Patent Document 10).

JP-A-9-156144 Japanese Patent No. 3581039 Japanese Patent No. 4186833 Design No. 1304306 Design No. 1304307 Japanese Patent No. 485749 Japanese Patent No. 3581084 Japanese Patent No. 3898690 Japanese Patent No. 5216467 Japanese Patent No. 3086810

By the way, when a cassette type thermal printer is mounted on a printer body with an ink ribbon suspended between a supply holder and a take-up holder of a ribbon holder cassette, the cassette type thermal printer does not detach and avoid interference with the thermal head held on the main body side. must not.
Some thermal printers, called continuous printers, that print on a packaging material in a transported state are rotated around a fulcrum for supporting a thermal head (see FIG. 7 of Patent Document 9). However, since the heater of the thermal head is moved in an arc to apply printing pressure, the mounting position relationship with the platen roller is very severe (see FIG. 8 of Patent Document 9), and the diameter of the platen roller and the distance to the platen roller change. Both the grounding angle of the thermal head heater and the peeling angle of the ink ribbon are greatly changed, which greatly affects the print quality.
In the thermal printer that prints by moving the thermal head on the stationary packaging material called intermittent, it is necessary to print while suppressing the slack generated from the change in the path length of the ink ribbon, There are ones in which a separation bar is attached to the thermal head carriage so that the path length does not change (for example, FIG. 9 of Patent Document 3), and the generated slack amount is sequentially removed by turning a winding holder ( (See Patent Document 10).

  In the present invention, when a detachable ribbon holder cassette is attached to the printer body, both continuous and intermittent thermal printers can be easily operated without rotating the thermal head supported by the printer body. It is an object of the present invention to provide a structure of an ink ribbon traveling unit that can be attached to the printer.

Via a supply holder on the driven side that is directly transmitted non-slip from a motor that is rotatably supported and installed in the printer body, and via a torque limiter that is rotatably supported and drives the friction of the supply holder concentrically. Measures the speed of the take-up holder that is transmitted, the thermal head pressing part that fixes the grounding angle of the heater of the thermal head and applies the printing pressure in the vertical direction, and the ink ribbon that is rotatably supported and installed on the printer body side A guide roller 49 for transmitting a peripheral speed to the rotary encoder, and a guide roller (45, 49) rotatably supported on both sides along the outer periphery of the frame plate in a direction perpendicular to the vertical direction across the thermal head When,
As an engagement part for engaging and avoiding the ink ribbon so as not to interfere with the thermal head held by the printer body between the guide rollers (45, 49) and the thermal head on the travel path of the ink ribbon. An avoidance guide supported together with a rack gear on a movable carriage of a supported rail, and a knob having the front face of the frame board that is held by a hand of the frame board, and turning the knob on the front face, thereby rotating the frame board to the axis of the knob. The key is fixed to the printer main body by a key groove provided at the tip of the printer, and is locked to the printer main body, and the rotation is transmitted to the rack gear via a spur gear rotatably supported. A lock mechanism that can freely avoid and move the avoidance guide supported together by moving a carriage to the position where it does not interfere;
The frame plate is mounted on the printer main body and locked by the rotation, and the winding of the ink ribbon on the traveling path is performed so as to stretch the slack of the ink ribbon caused by the change of the path length of the ink ribbon by the movement of the avoidance guide. A step roller suspended from the ink ribbon, which is arranged so that two guide rollers (49, 50) supported in front of the holder are arranged, and the ink ribbon is routed so that the path length of the ink ribbon can be changed. The torque limiter having a holding torque sufficient to prevent the ink ribbon from being dragged out by loading the ink ribbon into the supply holder and the winding holder and lifting the step roller up to an upper limit.
The step roller is also provided with a function of removing the slack amount of the ink ribbon that changes in accordance with the movement of the thermal head when incorporated in the intermittent machine that performs printing while moving the thermal head. A structure of an ink ribbon running unit is provided.

  In the application of this structure, the tip of the avoidance guide is detected as a sensor dog by a sensor provided in the printer body so that the end point of the avoidance movement can be determined.

  In the application of this structure, the tip of the step roller is used as a sensor dog to detect the absolute position with a sensor provided in the printer body so that the tension of the ink ribbon can be determined.

  In a cassette-type thermal printer that is used with a ribbon holder cassette that can be attached to and detached from the printer body, the thermal head supported by the printer body is simply avoided by the avoidance guide when it is installed. There is no need to move the thermal head, and there is no effect on the print quality caused by moving the head, and the operation of tensioning the ink ribbon by the step roller acts both on and off by the rotation of the knob that locks the printer body and ribbon holder cassette. It is possible to provide a structure of the ink ribbon running unit that can improve the work without damaging and cutting the ultra-thin ink ribbon at the edge of the thermal head heater during attachment / detachment during the work.

  In this structure, the tip of the avoidance guide is detected as a sensor dog by a sensor provided in the printer body so that the end point of the avoidance movement can be determined, so that the drive motor is driven on the driven side while the ink ribbon is detected. It is not necessary to engage with the supply holder, and after confirming that the ribbon holder cassette is locked to the printer body by the rotation of the knob and the knob continues to rotate, the evacuation guide has been fully evacuated, and then the drive motor is driven. And can be fitted with a supply holder on the driven side.

In this structure, the tip of the step roller is used as a sensor dog to detect the absolute position of the sensor provided on the printer body and judge the tension of the ink ribbon, so the upper limit that the torque limiter built in the take-up holder can follow Can know.
As a result (in paragraph No. 0035 of Patent Document 3, in the region of 17 to 18 inches / sec or less in which the behavior starts to change depending on the ribbon tape feed speed, the method of driving the feed shaft ... keeps good print quality. )), But
Although this structure is a feed shaft drive that drives the supply holder described in the above-mentioned patent document, the step roller absorbs the winding delay due to the slipping of the torque limiter even at a speed of 17 to 18 inches / sec or more of the ink ribbon feed. 1 can be maintained, and the upper limit of the feed rate can be obtained from the step roller lower limit 51f shown in FIG. 1 by the above-described sensor that detects the tip of the step roller. It is possible to perform printing up to a high-speed area with confidence.

  In this structure, the step roller removes the slack amount of the ink ribbon that changes according to the movement of the thermal head when it is incorporated into an intermittent machine that prints while moving the thermal head, so a peeling bar is mounted on the thermal head carriage. There is no need for this, and there is no need to turn the take-up holder during running printing so that the slack amount is taken up in sequence, so that it is possible to provide a legitimate one for incorporation into the intermittent type.

3A is a plan view showing the entire ribbon holder cassette and the printer main body on the right side of the fold with the handle side as the front, and FIG. 3B is a plan view showing only the ribbon holder cassette. (C) is a plan view showing a bottom surface of a slide rail portion that is moved by rotation of a knob of a ribbon holder cassette. From the embodiment of FIG. 1, the guide roller held along the outer periphery of the frame plate behind the thermal head connector is lowered in the vertical direction, moved to the bottom corner of the frame plate, and held at the rear as well. The main body of the printer, which shows that it has a structure that can be removed without interfering with the thermal head, even if it has a configuration in which one set of the retracting guide is deleted, and that includes a thermal head printing part and a thermal head holding part by a solenoid Top view of folding from the side FIG. 2A shows a modification of FIG. 2 that shows a structure that can be attached and detached without interfering with the thermal head even when the thermal head is assembled on an intermittent machine that performs printing while moving. FIG. 5B is a plan view of the folding seen from the printer body side, including a thermal head printing portion and a thermal head holding portion by a solenoid, and FIG. 3B shows the same amount of slack in the ink ribbon that occurs in the running printing operation as in FIG. Explanatory drawing shown in reduced scale, (C) is a plan view showing slack suppression by a peeling bar mounted on a conventionally used thermal head carriage, which is a part of (Patent Document 3 FIG. 9).

  Hereinafter, a preferred embodiment as a structure of an ink ribbon traveling portion according to the present invention will be described by dividing it into a first embodiment, a second embodiment, and a third embodiment. In addition, in drawing demonstrated below, what has the same function attaches the same code | symbol.

(First embodiment)
The first embodiment is implemented by arranging this embodiment in a continuous thermal printer with reference to FIG. 1. A pair of avoidance guides are arranged across the thermal head, and ink at two places before and after the thermal head is arranged. It is characterized by avoiding interference with the thermal head by pushing down the inner surface of the ribbon and removing it.

On the frame plate 1 on the ribbon holder cassette side, a supply take-up drive unit that drives the supply holder 15 and the take-up holder 10 by a single drive motor 42 that is rotatably supported and installed on the frame plate printer body 2. 54
(Paragraph No. 3, paragraph 0035, the method of driving the feed shaft is explained. The drive of the drive motor is directly transmitted to the supply holder, and whenever the take-up holder takes up, the ink ribbon is always applied to the ink ribbon. After changing the tension to the speed at which it can be transmitted, it is done via a one-way clutch and a torque limiter that drives friction, and when the supply holder is rewound by pulling out the ink ribbon of the take-up holder, it is connected to the drive side of the torque limiter (The brake mechanism using a one-way clutch is used to apply braking to stop the rotation of the torque limiter on the drive side and use the torque limiter as a friction brake to obtain tension)
As a non-slip (by fitting with the spring plunger 39 embedded in the reduction gear 40 and the drive fitting hole 16 provided in the supply holder 15), the supply holder 15 on the driven side and the driven holder 15 are rotatably supported and supplied. A winding head 10 that transmits the rotation of the holder 15 concentrically through a friction limiter 9 that drives friction, and a thermal head that applies a printing pressure in the vertical direction while fixing the ground angle 53a of the heater 30b of the thermal head 30. The peripheral speed is transmitted to the pressing part (consisting of the thermal head holding part 34 and the thermal head printing pressure part 35) and the rotary encoder 49a that measures the speed of the ink ribbon that is rotatably supported and installed on the frame plate 2 (friction clutch). Frame) in a direction perpendicular to the vertical direction across the guide roller 49 and the thermal head 30. And (guide roller 49 is also provided with serve to convey 45 and peripheral speed) rotatably supported guide rollers on both sides along one of the outer periphery,
As an engaging portion for engaging and avoiding the ink ribbon so as not to interfere with the thermal head 30 held by the frame printer body 2 between the guide rollers (45, 49) and the thermal head 30 on the travel path of the ink ribbon. A frame plate is formed by rotating a knob 21 having a front surface with the avoidance guide 28 supported by the movable carriage 26 of the supported rail 25 together with the rack gear 27 held by the hand of the frame plate 1 as a front surface. 1 is fitted to a key 23 fixed to the frame plate printer main body 2 by a key groove 24 provided at the tip of the shaft 22 of the knob 21 to be locked to the frame plate printer main body 2 and is press-fitted and fixed to the shaft 22. The rotation of the spur gear 48 is transmitted to the rack gear 27 via a spur gear 46 and a spur gear 47 that are supported directly on one rack gear 27 and rotatably on the other. A lock mechanism is brought freely avoided moved together to a position not interfering the avoidance guide 28 which supports (interference avoidance gaps 51a, produce 51c position) by moving the Dodaisha 26,
The frame plate 1 is mounted on the frame plate printer main body 2 and locked by the rotation of the knob 21. The movement of the avoidance guide 28 results from the change in the path length of the ink ribbon (transition from the interference avoidance gap 51a to the print path 51b). Two guide rollers (49, 50) supported in front of the take-up holder 10 are arranged on the travel path so as to stretch the slack of the ink ribbon, and the ink ribbon is passed between them so that the path length of the ink ribbon can be changed. The step roller 18 suspended from the ink ribbon to be loaded, the ink ribbon is loaded into the supply holder 15 and the take-up holder 10, and the step roller 18 is lifted up to the upper limit 51e so as to have a holding torque sufficient to prevent the ink ribbon from being dragged out. A torque limiter 9 selected and incorporated in the winding holder 10;
The supply holder 15 and the take-up holder 10 are provided with a spring plunger 11 that fits in a key groove formed in the ink ribbon core so that the ink ribbon supply 44 and the ink ribbon take-up 43 can rotate together without slipping. It has the structure of the provided ink ribbon running part.

  The tip of the avoidance guide 28 is detected as an avoidance guide shaft tip dog 29 by the avoidance guide detection sensor 32 provided in the frame plate printer main body 2 so that the end point of the avoidance movement (position where the interference avoidance gap 51c is created) can be determined.

  The absolute position (step roller upper limit 51e, step roller lower limit 51f) is detected by the step roller detection sensor 36 provided in the frame plate printer body 2 with the tip of the step roller 18 as the step roller shaft tip dog 19 to determine the tension of the ink ribbon. I can do it.

  The heater of the thermal head 30 is arranged so as to be the center of the frame printer body 2 (the center 52 in the width direction), and a pair of avoidance guide rails on the path of the ink ribbon in a place straddling the thermal head 30. 25 is arranged in the shape of a letter C (consisting of a slide rail center line 55 located behind the thermal head and a slide rail center line 56 located in front of the thermal head). 30 so that the same mounting bracket can be used for attaching the frame plate printer main body 2 even if it is a wrong machine.

(Second Embodiment)
In the second embodiment, referring to FIG. 2, the present embodiment is arranged and implemented in a continuous thermal printer, and a pair of avoidance guides of the first embodiment is used as one avoidance guide. The feature is to reduce the number of parts by deleting.

  The guide roller 45 on the connector 30a side of the thermal head 30 is lowered along the outer periphery of the frame plate 1 to be disposed and supported at the corner of the frame plate, and one set of avoidance guides 28 also on the connector 30a side is reduced. In addition, the ink ribbon traveling portion has a structure.

  Since the thermal head 30 operates vertically by the mechanism of the thermal head holding part 34 and the thermal head printing pressure part 35, the grounding angle 53a of the thermal head 30 and the peeling angle 53b of the ink ribbon are stable.

(Third embodiment)
In the third embodiment, referring to FIG. 3, the present embodiment is arranged and implemented in an intermittent thermal printer that performs printing while traveling, and the spring plunger 11 is shown in FIG. 1 (b) of Patent Document 7. The supply winding drive unit 54 (FIG. 11 of Patent Document 3), the thermal head holding unit 34 (FIG. 4 of Patent Document 3), and the thermal head printing pressure unit 35 (FIG. 5 of Patent Document 3) This is implemented for reference, and this part is the same as in the first and second embodiments.

  FIG. 3B shows the ink ribbon slack generated in the traveling printing operation of FIG. 3A at the same scale. The slack due to the difference in the path length has a holding torque stronger than that of the step roller 28. By the torque limiter 9 selected and incorporated in the take-up holder 10, the step roller 28 is lifted to the step roller upper limit 51e when the take-up holder 10 takes up the used ink ribbon every time printing is finished, so that the slack is removed. Therefore, the peeling bar 58 provided so that the path length cannot be changed as shown in FIG.

  In the configuration shown in FIG. 3A, the peel angle 53b changes, and therefore, the print length at which the peel angle 53b can be 15 degrees or more is suitable for a travel movement stroke of about 50 mm.

The structure of the ink ribbon traveling portion according to the present invention has been specifically described above with reference to the drawings. However, the structure is not limited to the above-described embodiment, and is within the scope of the claims. Needless to say, various modifications and changes may be made.
For example, the avoidance guide 28 may be a roller that is a rotating body, or may be a plate that slides well, or may be used as a guide roller for an ink ribbon with increased rigidity.
As long as the rail 25 and the movable carriage 26 are used, there are products called a slide rail, a slide guide, and a linear guide.

1 Frame plate (ribbon holder cassette)
2 Frame plate printer body 3 Spur gear 4 One-way clutch (When the supply side rewinds, the inner ring of the torque limiter is locked)
5 Spur gear 6 Timing pulley 28
7 One-way clutch (locked and transmitted during winding operation)
8 Winding shaft 9 Torque limiter 10 Winding holder 11 Spring plunger 12 Timing belt 13 Timing pulley 78
14 Supply shaft 15 Supply holder 16 Drive fitting hole 17 Pull spring 18 Step roller 19 Step roller shaft tip dog 20 Handle 21 Knob 22 Shaft 23 Key 24 Key groove 25 Rail 26 Movable carriage 27 Rack gear 28 Avoidance guide 29 Avoidance guide shaft tip dog 30 Thermal head (Corner edge type)
30a Connector 30b Heater 31 Tip dog path 32 Avoidance guide detection sensor 33 Keyway shaft fixing screw 34 Thermal head holding part 35 Thermal head pressure part 36 Step roller detection sensor 37 Tip dog path 38 Drive fitting path 39 Spring plunger 40 Reduction gear 41 Motor pulley 42 Drive motor 43 Ink ribbon take-up 44 Ink ribbon supply 45 Guide roller 46 Spur gear 47 Spur gear 48 Spur gear 49 Guide roller (Detection of peripheral speed)
49a Rotating encoder 50 Guide roller 51a Interference avoidance gap 51b Print path 51c Interference avoidance gap 51d Movable carriage retreat position 51e during printing Step roller upper limit 51f Step roller lower limit 51g Winding direction 52 of used ink ribbon Vertically printing thermal head 53a indicating the center of the frame plate in a direction perpendicular to the heater 53a Grounding angle 53b Peeling angle 54 Supply winding drive unit 55 Slide rail center line 56 arranged behind the thermal head 56 Slide rail center line 57 arranged ahead of the thermal head Print path 57a Print path 57b Print path 57c Print path 57a-57b 58 Peeling bar showing the print stroke of the thermal head head traveling movement when printing pressure is applied

Claims (3)

Via a supply holder on the driven side that is directly transmitted non-slip from a motor that is rotatably supported and installed in the printer body, and via a torque limiter that is rotatably supported and drives the friction of the supply holder concentrically. Measures the speed of the take-up holder that is transmitted, the thermal head pressing part that fixes the grounding angle of the heater of the thermal head and applies the printing pressure in the vertical direction, and the ink ribbon that is rotatably supported and installed on the printer body side A guide roller 49 for transmitting a peripheral speed to the rotary encoder, and a guide roller (45, 49) rotatably supported on both sides along the outer periphery of the frame plate in a direction perpendicular to the vertical direction across the thermal head When,
As an engagement part for engaging and avoiding the ink ribbon so as not to interfere with the thermal head held by the printer body between the guide rollers (45, 49) and the thermal head on the travel path of the ink ribbon. An avoidance guide supported together with a rack gear on a movable carriage of a supported rail, and a knob having the front face of the frame board that is held by a hand of the frame board, and turning the knob on the front face, thereby rotating the frame board to the axis of the knob. The key is fixed to the printer main body by a key groove provided at the tip of the printer, and is locked to the printer main body, and the rotation is transmitted to the rack gear via a spur gear rotatably supported. A lock mechanism that can freely avoid and move the avoidance guide supported together by moving a carriage to the position where it does not interfere;
The frame plate is mounted on the printer main body and locked by the rotation, and the winding of the ink ribbon on the traveling path is performed so as to stretch the slack of the ink ribbon caused by the change of the path length of the ink ribbon by the movement of the avoidance guide. A step roller suspended from the ink ribbon, which is arranged so that two guide rollers (49, 50) supported in front of the holder are arranged, and the ink ribbon is routed so that the path length of the ink ribbon can be changed. The torque limiter having a holding torque sufficient to prevent the ink ribbon from being dragged out by loading the ink ribbon into the supply holder and the winding holder and lifting the step roller up to an upper limit.
The step roller is also provided with a function of removing the slack amount of the ink ribbon that changes in accordance with the movement of the thermal head when incorporated in the intermittent machine that performs printing while moving the thermal head. Structure of the ink ribbon running part.   2. The structure of the ink ribbon traveling unit according to claim 1, wherein a tip of the avoidance guide is detected as a sensor dog by a sensor provided in the printer body so that an end point of the avoidance movement can be determined.   2. The structure of the ink ribbon traveling unit according to claim 1, wherein the tip of the step roller is used as a sensor dog so that a sensor provided in the printer main body can detect an absolute position and determine the tension of the ink ribbon. .

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