JP3704945B2 - Printer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a printer mounted on a POS terminal or the like capable of printing on roll paper. More specifically, the present invention relates to a printer configured to move a roll paper feed roller in conjunction with an opening / closing lid of a roll paper loading unit so that the roll paper can be easily loaded.
[0002]
[Prior art]
In a printer that performs roll paper printing, there is a roll paper loading mechanism that can fully open and close the open / close lid that opens and closes the roll paper loading section formed on the printer body so that the roll paper can be easily replaced or replenished. Proposed. For example, Japanese Patent Publication No. 6-79855 proposes a recording apparatus having such a roll paper loading mechanism.
[0003]
In the recording apparatus disclosed in this publication, both end portions of a support shaft of a platen roller (roll paper feed roller) pressed against a thermal head are supported by long holes formed at the tip of a support member. The support member can pivot together with a cover that functions as an opening / closing lid of the roll paper loading unit. By fully opening the cover, the roll paper can be easily attached to the roll paper loading unit. Further, since the platen roller is also separated from the thermal head by opening the cover, the roll paper unwinding portion can be easily disposed between the platen roller and the thermal head.
[0004]
Furthermore, when the cover is closed, the support shafts at both ends of the platen roller are pushed toward the thermal head by the engagement pieces formed at the tip of the cover. Since both end portions of the support shaft of the platen roller are supported by the long holes, when pressed by the engagement piece, the platen roller moves to the thermal head side along the long holes, and moves to the thermal head held by the spring. A pressed state is formed. Therefore, a state in which the roll paper is sandwiched between the thermal head and the platen roller can be automatically formed.
[0005]
[Problems to be solved by the invention]
Here, the roll paper loading mechanism configured as described above can be similarly applied to a printer including an inkjet head or a wire dot head. However, in this case, the following problem occurs.
[0006]
That is, unlike a thermal head, an inkjet head or a wire dot head needs to maintain a certain gap between the head and the printing surface of the roll paper.
[0007]
If this gap fluctuates, the print quality may be reduced. Further, when the print surface of the roll paper comes into contact with the head, the print surface is stained with ink or the like. Furthermore, there is a possibility that the roll paper jams at the print position by the head.
[0008]
However, since the roll paper is wound in a roll shape, the roll paper unwound from the roll paper has a curl and is curved in a direction perpendicular to the paper surface of the roll paper. Therefore, even if the gap between the print head and the platen roller can be kept constant, the roll paper conveyed there is curved so as to protrude toward the print head. The gap is not maintained at an appropriate dimension, and is not maintained at a constant dimension over the entire printing surface.
[0009]
In view of this point, an object of the present invention is to provide a printer having a roll paper loading mechanism configured to move a roll paper feed roller in conjunction with an opening / closing lid of a roll loading unit. The purpose is to keep the gap of the surface constant.
[0010]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a print head, a roll paper feed roller for transporting the roll paper via a print position by the print head, and a roll paper loading unit in which the roll paper is loaded. And an open / close lid that opens and closes the roll paper loading unit, and the roll paper feed roller moves to an operating position and a retracted position in conjunction with opening and closing of the open / close lid. The print surface portion of the roll paper to be transported has tension applying means capable of applying a tensile force in the transport direction, and the tension applying means is provided when the roll paper feed roller is in the operating position. A tensile force is applied to the print surface portion of the roll paper, and the tensile force is released when the roll paper feed roller is in the retracted position.
[0011]
In the printer of the present invention, the tension is applied to the printing surface portion of the roll paper conveyed at the printing position in the conveyance direction by the tension applying means. By this tensile force, the roll paper that is curled and conveyed in a curved state is stretched, so that the printed surface portion is forced to be a flat surface. As a result, the gap between the print head and the print surface portion of the roll paper is kept appropriate and constant. Therefore, it is possible to avoid the deterioration of the printing quality caused by the gap fluctuation, the contamination of the roll paper surface, and the jamming of the roll paper at the printing position.
[0012]
Here, in a typical roll paper loading mechanism, the roll paper feed roller is attached to the opening / closing lid, and is configured to reach the operating position when the opening / closing lid is closed. Also, a paper guide for guiding the roll paper toward the roll paper feed roller is attached to the opening / closing lid. In this case, when the opening / closing lid is closed, the print surface portion of the roll paper is stretched between the paper guide and the roll paper feed roller. That is, a gap between the print head and the print surface portion of the roll paper is defined by the roll paper feed roller and the paper guide.
[0013]
In the printer having such a roll paper loading mechanism, the tension applying means includes a pressing member capable of pressing the roll paper against the paper guide with a predetermined elastic pressing force when the opening / closing lid is closed. It can be of a configuration.
[0014]
The downstream side portion of the roll paper in the transport direction of the print surface portion is pulled in the transport direction by the roll paper feed roller. On the other hand, the roll paper portion on the upstream side in the transport direction from the print surface portion is pressed against the paper guide by the pressing member. As a result, a tensile force acts on the print surface portion of the roll paper in the transport direction, and the curved state of the roll paper is corrected, so that a substantially flat surface is obtained. As a result, the gap between the print head and the print surface portion can be maintained at an appropriate size and a constant size.
[0015]
As the pressing member, a rotatable pressing roller can be used. In this case, the outer peripheral surface of the pressing roller may be pressed against the paper guide with the roll paper interposed therebetween.
[0016]
Here, in order to more easily adjust the tensile force applied to the roll paper and to apply a stable tensile force to the roll paper, the pressing force in the paper guide is used as the tension applying means. It is desirable to use a configuration having a brake roller arranged in a portion pressed by a member. The brake roller has a predetermined elastic braking force against rotation in the roll paper conveyance direction. When the open / close lid is closed, the roll paper is sandwiched between the brake roller and the pressing member. A state is formed.
[0017]
In this case, the brake roller may include a roller body that is rotatably supported and a pressing spring that applies a predetermined elastic force to a side surface of the roller body.
[0018]
An ink jet head or a wire dot head can be adopted as the print head.
[0019]
Further, in this specification, the term “printing” is used as a term synonymous with “printing” and “recording”. That is, it is used as a term including not only printing of characters but also printing of other patterns, symbols, and the like.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an ink jet printer to which the present invention is applied will be described below with reference to the drawings.
[0021]
(Overall configuration of inkjet printer)
FIG. 1 is a perspective view of an ink jet printer to which the present invention is applied, and FIG. 2 is an explanatory view showing the paper conveyance path. As shown in these drawings, the ink jet printer 1 has a roll paper loading mechanism 2 and a single sheet insertion slot 3 of A4 size or the like, and the roll paper 4 and the single sheet paper supplied from the roll paper loading mechanism 2. The conveyance path is configured so that the cut sheet 5 inserted from the insertion port 3 is conveyed through a common printing position 11 (area surrounded by a one-dot chain line in the drawing). A guide shaft 6 is disposed in parallel to the common printing position 11, and a carriage 7 on which the inkjet head 8 is mounted can reciprocate along the guide shaft 6. Therefore, desired printing is performed by the inkjet head 8 on the surfaces of the roll paper 4 and the cut sheet 5 that pass through the common printing position 11.
[0022]
Ink is supplied to the inkjet head 8 from an ink supply unit 10 mounted at a position adjacent to the roll paper loading mechanism 2 via an ink tube (not shown).
[0023]
(Configuration of tension applying means)
Here, the roll paper 4 is unwound from the roll body 4 </ b> A wound in the roll shape loaded in the roll paper loading mechanism 2, and is conveyed via the printing position 11. Accordingly, the roll paper has a curl and the portion of the roll paper that passes through the printing position 11 tends to bend in a convex state toward the inkjet head 8. In this example, a tension applying means is provided in order to form a flat print surface portion by correcting the curvature of the portion of the roll paper passing through the print position 11, that is, the print surface portion.
[0024]
FIG. 3 is an enlarged view of the main components of the roll paper conveyance path of the inkjet printer 1 centered on the printing position 11. With reference to FIG. 3 and FIG. 2, the tension | tensile_strength provision means of this example is demonstrated.
[0025]
As shown in these drawings, the roll body 4A is supported by a pair of front and rear support rollers 13 and 14 which are disposed on the bottom surface of a roll paper loading unit which will be described later. The roll paper 4 unwound from the roll body 4A passes between the paper guide 27 and the pressing roller 15 as a pressing member, and is positioned above the convex curved surface 27a of the paper guide 27. The platen roller (roll paper feed roller) 26 is guided. Next, the roll paper 4 passes between the platen roller 26 and the pressing roller 16 pressed against the platen roller 26 and is discharged to the outside.
[0026]
Here, the portion of the roll paper 4 that is stretched between the paper guide 27 and the platen roller 26 is located at the printing position 11 by the inkjet head 8. That is, this portion of the roll paper 4 is a print surface portion 4 </ b> B on which printing is performed by the inkjet head 8.
[0027]
Although the detailed structure will be described later, the platen roller 26 and the paper guide 27 are attached to the tip of a slide frame 25 (see FIG. 6), which is a component of the opening / closing lid of the roll paper loading mechanism 2, and the slide It moves together with the frame 25. 2 and 3 show the position of the platen roll 26 and the paper guide 27 with the slide frame 25 closed, and this position is referred to herein as the “operation of the platen roller 26 as needed. Called “position”. In addition, the position of the platen roller 26 that is opened from the slide frame 25 and retracted from the operation position along with the slide frame 25 is referred to as a “retraction position”.
[0028]
When the platen roller 26 is set at its operating position, the platen roller 26 is connected to a driving force transmission mechanism (not shown) and is driven to rotate. As described above, the pressing roller 16 is pressed against the outer peripheral surface of the platen roller 26 by a certain elastic force. Accordingly, the roll paper 4 sandwiched between the rollers 26 and 16 is conveyed as the platen roller 26 rotates.
[0029]
Here, the tension applying means of this example is constituted by the pressing roller 15. The pressing roller 15 includes a rotation center shaft 15a, a roller body 15b rotatably supported by the rotation center shaft 15a, and a spring member that urges both ends of the roller rotation center shaft 15a toward the paper guide 27. 15c.
[0030]
The pressing roller 15 is pressed against the surface 27 a of the paper guide 27 with a certain elastic force at a position upstream of the print surface portion 4 B of the roll paper 4 in the transport direction. Accordingly, a tensile force acts on the roll paper 4 that passes between these and is pulled by the rotational force of the platen roller 26. That is, since the roll paper 4 is pressed against the surface 27a of the paper guide 27 with a certain elastic force, the roll paper stretched between the pressing roller 15 and the platen roller 26 by the sliding frictional resistance generated thereby. A tensile force acts on the print surface portion 4B of 4 along the transport direction.
[0031]
As a result, even if the roll paper 4 is wrinkled, the printing surface portion 4B of the roll paper 4 located at the printing position 11 by the ink jet head 8 is substantially flat because its curvature is corrected by the tensile force. It is considered a surface. Therefore, the gap between the ink jet head 8 and the printing surface portion 4B is kept constant, so that it is possible to avoid the deterioration of printing quality caused by the gap fluctuation, the occurrence of dirt on the roll paper surface, the jamming of the roll paper at the printing position, etc. .
[0032]
(Another configuration of tension applying means)
Next, FIGS. 4 and 5 show modifications of the tension applying means having the above-described configuration. The tension applying means shown in these drawings can more easily adjust the tensile force applied to the roll paper, and can apply a stable tensile force to the roll paper. In order to achieve this object, the tension applying means of this example is configured such that the brake roller 17 is disposed on the surface portion of the paper guide 27 that is pressed by the pressing roller 15.
[0033]
The brake roller 17 is applied with a predetermined elastic braking force against rotation in the roll paper conveyance direction. Then, the roll paper 4 is sandwiched.
[0034]
As can be seen from FIG. 5, the brake roller 17 includes a rotation center shaft 17a, a roller body 17b rotatably supported by the rotation center shaft 17a, and a side surface of the roller body 17b that is fixed in the direction of the rotation axis. And a pressing mechanism 17c that is pressed by an elastic force. The pressing mechanism 17c includes a receiving plate 17d that contacts one side surface of the roller body 17b, a pressing plate 17e that contacts the other side surface, and a coil spring 17f that presses the pressing plate 17e toward the side surface of the roller body 17b. Has been.
[0035]
The pressing roller 15 in contact with the brake roller 17 includes a rotation center shaft 15a, a roller body 15b that is rotatably supported by the rotation center shaft 15a, and the rotation center shaft 15a. It is comprised from the spring member 15c pressed toward the inside with a fixed elastic force.
[0036]
In the tension applying means having this configuration, the roll paper 4 is sandwiched between the pair of rollers 15 and 17, and an elastic braking force is applied to the rotation of one roller 17, and the sliding friction resistance of the roll paper 4 generated thereby is used. Thus, a tensile force is applied to the roll paper 4. Accordingly, the tension force to be applied is adjusted compared to the case where a tensile force is applied to the roll paper 4 due to the sliding frictional resistance of the roll paper 4 generated by pressing and fixing the pressing roller 15 on the surface of the paper guide 27. Can be simplified, and a stable tensile force can be generated.
[0037]
(Roll paper loading mechanism 2)
Next, the structure of the roll paper loading mechanism 2 in this example will be described in detail.
[0038]
6 is a perspective view showing a part of the roll paper loading mechanism 2 taken out, FIGS. 7 to 10 are explanatory views showing the opening and closing operation of the roll paper loading unit, and FIG. 11 is an explanation showing a partial configuration thereof. FIG.
[0039]
Referring to these drawings, the roll paper loading mechanism 2 has a mounting frame 21 attached to the printer main body frame 12, and the roll paper loading mechanism 21 is loaded with the roll paper 4. Part 22 is configured. The roll paper loading unit 22 includes a semicircular curved portion 22a having a certain width and a rectangular opening 22b formed above, and the roll paper 4 is exchanged or replenished through the opening 22b.
[0040]
The roll paper loading opening 22 b can be opened and closed by a lid frame 23. The lid frame 23 includes a top plate portion 23a having a rectangular shape substantially the same as the opening 22b, and side plate portions 23b and 23c having a certain height and bent downward at right angles from the left and right of the top plate portion 23a. The rear end portions of the side plate portions 23b and 23c are bent downward, and the lower ends 23d and 23e (only the lower end 23d is shown in the figure) are rotatably supported by a shaft 24 that defines the turning center. Yes. Both ends of the shaft 24 are supported by the mounting frame 21. Accordingly, the lid frame 23 has the shaft 24 as the center, the closed position (the state shown in FIG. 7) where the roll paper loading opening 22b of the roll paper loading unit 22 is closed, and the open position where the opening 22b is fully opened. (The state shown in FIG. 10) can be turned.
[0041]
A slide frame 25 is attached to the lid frame 23 having this configuration. The slide frame 25 pivots integrally with the lid frame 23 and is slidable with respect to the lid frame 23, and has a platen roller 26 and a roll paper 4 on the platen roller 26 at the tip. Is attached. Thus, in this example, the lid frame 23 and the slide frame 25 constitute an open / close lid of the roll paper loading unit 22.
[0042]
First, a configuration in which the slide frame 25 is slidably attached to the lid frame 23 will be described with reference to FIG. The slide frame 25 includes a rectangular top plate portion 25a that is in contact with the back side of the top plate portion 23a of the lid frame 23, and a side plate that is bent downward at a right angle from both sides of the top plate portion 25a. And portions 25b and 25c. Guide slits 25d and 25f are formed in the top plate portion 25a in the front-rear direction, and guide pins 23q and 23r fixed to the surface plate portion 23a of the lid frame 23 pass through these slits. . Retaining rings 23h and 23i are attached to the lower ends of the guide pins 23q and 23r, whereby the slide frame 25 is slidably attached to the back surface of the lid frame 23.
[0043]
A coil spring 23g is bridged between a guide pin 23r on the rear side and a spring hook 25g formed on the front side portion of the slide frame 25, and the slide force is generated by the spring force of the coil spring 23q. The frame 25 is always biased rearward.
[0044]
Next, as can be seen from FIG. 6, a platen roller 26 is bridged between the front ends 25h, 25i of the side plate portions 25b, 25c of the slide frame 25, and both end portions of the support shaft of the platen roller 26 are at the front end. It is rotatably supported by 25h and 25i. A paper guide 27 having a convex arcuate surface shape is attached to the lower side of the platen roller 26 from the outer peripheral surface of the platen roller 26 toward the tangential direction.
[0045]
Here, when the platen roller 26 supported at the tip of the slide frame 25 is set to the operating position, the pressing roller 16 attached to the printer main body side on the outer peripheral surface of the platen roller 26 has a certain elasticity. A pressed state is formed with force. That is, the pressing roller 16 is slightly movable in the direction in which the rotation center shaft 16a approaches and separates from the platen roller 26, and is always urged toward the platen roller 26 by a spring force. Therefore, when the platen roller 26 is positioned at its operating position against the spring force, the outer peripheral surface of the platen roller 26 is pressed by the pressing roller 16 with the roll paper 4 sandwiched by a certain spring force. Become. As a result, when the platen roller 26 is rotationally driven, the roll paper 4 sandwiched between these rollers can be conveyed.
[0046]
Similarly, the surface 27a of the paper guide 27 attached to the tip of the slide frame 25 together with the platen roller 26 also applies the elastic force to the pressing roller 15 attached to the printer main body when the platen roller 26 reaches the operating position. Move against. As a result, the surface 27a of the paper guide 27 is also pressed by the pressing roller 15 with a certain elastic force with the roll paper 4 interposed therebetween.
[0047]
Next, a cover frame 28 having a size slightly larger is disposed on the upper side of the lid frame 23. The cover frame 28 includes a top plate portion 28a and side plate portions 28b and 28c bent at right angles downward from both sides thereof, and rear end portions of the side plate portions 28b and 28c extend downward. The shaft 24 is rotatably supported. When the cover frame 28 is turned, the lid frame 23 to which the slide frame 25 is attached is turned in conjunction with the cover frame 28. Further, after the lid frame 23 reaches the state (the state shown in FIG. 8) where the opening 22b for loading the roll is sealed, the cover frame 28 can be turned independently. The slide frame 25 slides in the front-rear direction with respect to the lid frame 23 by the single turning motion of the cover frame 28.
[0048]
The link mechanism 29 for converting the single pivot motion of the cover frame 28 into the slide motion of the slide frame 25 includes a connection shaft 28d spanned between the rear upper end portions of the side plate portions 28b and 28c of the cover frame 28, and the connection shaft. There are provided connection holes 25j formed in three places at the rear end portion of the slide frame 25 through which 28d passes. The connection hole 25j has a long and long hole shape so as not to hinder the single turning movement of the cover frame 28. Accordingly, the position of the connecting shaft 28d in the state where the cover frame 23 seals the opening 22b for loading the roll paper as shown in FIG. 8 further turns the cover frame 28 to the horizontal state as shown in FIG. In this case, the position is moved forward and downward about the shaft 24 that defines the turning center.
[0049]
The connecting shaft 28d freely moves downward along the vertically long connecting hole 25j and moves the connecting hole 25j by pushing it forward. As a result, the slide frame 25 in which the connection hole 25j is formed is pushed forward as a whole. That is, it slides forward with respect to the lid frame 23, the platen roller 26 and the paper guide 27 supported at the front end thereof protrude forward, and appear at the printing position 11 by the ink jet head 8, with respect to the ink jet head 8. It will be in the state (operating position) facing each other while maintaining a certain gap.
[0050]
Conversely, when the cover frame 28 is pivoted upward from the horizontal position shown in FIG. 7 to the position shown in FIG. 8, the slide frame 25 slides rearward as a whole, and the platen roller 26 at the tip thereof is reversed. The paper guide 27 moves from the operating position to the retracted position.
[0051]
Here, as described above, the slide frame 25 is urged by the coil spring 23g by an elastic force in the backward direction. Therefore, when the pressing force of the cover frame 28 is released after the cover frame 28 is closed to become horizontal as shown in FIG. 7, the slide frame 25 returns to its retracted position by the pulling force of the coil spring 23g. In conjunction with this sliding movement, the cover frame 28 also pivots in the opening direction and returns to the state shown in FIG.
[0052]
In order to lock the cover frame 28 in the closed position shown in FIG. 7, a pair of left and right engaging claws 28 g and 28 h are attached to the front end portion of the cover frame 28. When the cover frame 28 is closed, the hooks formed at the tips of the engaging claws 28g and 28h face the front portion of the mounting frame 21 where the hook pivots from below to be engaged. An engaging portion 21g is formed. The engaging claws 28g and 28h are always urged toward the direction in which the hook pivots upward by a torsion spring (not shown).
[0053]
Therefore, when the cover frame 28 is closed as shown in FIG. 7 and further pushed in, the engaging claws 28g and 28h slightly turn to the opposite side against the spring force, and the hooks at the lower ends thereof are lowered. Is engaged with the engaged portion 21g on the mounting frame 21 side to form a locked state. In order to release the lock, the upper end portions 28i of the engaging claws 28g and 28h may be pulled up and the lower end hooks may be turned downward.
[0054]
Next, in the roll paper loading mechanism 2 of this example, a mechanism for accurately positioning the position (operating position) of the platen roller 25 at the tip of the slide frame 25 with the cover frame 28 closed as described above. Is equipped. That is, positioning pins 25k and 25l for position definition (only the pin 25k is shown in FIG. 6) protruding horizontally to the left and right are attached to the front end portions of the side plate portions 25b and 25c of the slide frame 25. Yes. On the other hand, in a state where the slide frame 25 is closed, a semicircular shape in which the positioning pins 25k and 25l are fitted just in the lateral direction in the portion of the mounting frame 21 facing the positioning pins 25k and 25l. Grooves 21k and 21l are formed.
[0055]
Since these grooves 21k and 21l are formed at fixed positions, the positioning pins 25k and 25l of the slide frame 25 fit into these grooves 21k and 21l, so that the position of the platen roller 26 at the tip of the slide frame 25 is reached. (Operating position) is always accurately defined. Therefore, the platen roller 26 is always constant between the ink nozzle surface of the inkjet head 8 that reciprocates left and right with a predetermined gap with respect to the printing surface 11 on which the outer peripheral surface of the platen roller 25 is located. A gap is formed.
[0056]
In addition, coil springs 23j and 23k (between both side walls 21b and 21c of the mounting frame 21 (only 21b is shown in FIG. 6)) and side plate portions 23b and 23c on both sides of the lid frame 23 are respectively provided. In the figure, only the spring 23j is shown). When the cover frame 28, the slide frame 25, and the lid frame 23 are opened and closed with the shaft 24 as the center, after the center of gravity passes through the swiveling position shown in FIG. These coil springs 23j and 23k are arranged so that the turning trajectory of the spring hooking portions at both ends of 23j and 23k is widened.
[0057]
Accordingly, when the cover frame 28 is further opened beyond the swivel position shown in FIG. 9, the coil springs 23j and 23k are extended, so that a pulling force that biases the cover frame 28 in the closing direction acts. As a result, it is possible to avoid the adverse effect that the cover frame 28 and the like open vigorously and collide with other parts.
[0058]
Conversely, even when the cover frame 28 is closed beyond the swivel position shown in FIG. 9, the cover frame 28 closes vigorously by the spring force of these coil springs 23j, 23k, and opens into the opening 22b of the roll paper loading unit. The adverse effect of colliding can be avoided.
[0059]
(Operation of roll paper loading mechanism)
The opening / closing operation of the roll paper loading unit 22 in the roll paper loading mechanism 2 will be described collectively with reference to FIGS. First, when the upper end portion 28i connected to the engaging claws 28g and 28h is pulled upward in the state where the roll paper loading unit 22 is closed as shown in FIG. 7, the engaging claws 28g and 28h are moved to the frame 21 side. Is disengaged from the engaged portion 21g and the lock is released. As a result, the cover frame 28, the slide frame 25, and the lid frame 23 are integrally turned to the position shown in FIG. This turning operation is performed mainly by the spring force of the coil spring 23g that spans between the slide frame 25 and the lid frame 23.
[0060]
Thereafter, when the cover frame 28 is rotated backward against the spring force of the coil springs 23j and 23k, the opening 22b of the roll paper loading unit 22 is opened as shown in FIG. Fully open. That is, all of the cover frame 28, the slide frame 25, and the lid frame 23 are retracted from above the opening 22b.
[0061]
After the fully opened state, the roll paper 4 loaded in the roll paper loading unit 22a is exchanged. Since the opening 22b is in a fully open state, the replacement work of the roll paper 4 is simple. Further, since the platen roller 26 and the paper guide 27 are also retracted together with the slide frame 25, the work of arranging the unwinding portion 4a of the roll paper 4 can be easily performed.
[0062]
After the roll paper 4 is loaded, the cover frame 28 is turned in the closing direction. By this operation, the cover frame 28, the slide frame 25, and the lid frame 23 rotate together, and after the state shown in FIG. 9, the lid frame 23 seals the opening 22b as shown in FIG. . After this, the lid frame 23 engages with the edge of the opening 22b and does not turn any further. Therefore, the slide frame 25 slidably attached to the lid frame 23 does not turn any further. Therefore, after this, only the cover frame 28 turns alone. When the cover frame 28 is pushed and swung to the position shown in FIG. 7, this swiveling motion is converted into a slide motion of the slide frame 25 via the link mechanism 29. That is, the slide frame 25 slides forward with respect to the lid frame 23, and the platen roller 26 and the paper guide 27 supported at the front end of the slide frame 25 face each other with a fixed gap (operation). Position). When the slide frame 25 slides forward, the positioning pins 25k and 25l at both ends of the slide frame 25 fit into the grooves 21k and 21l on the mounting frame 21 side, and the slide position is fixed. In other words, the platen roller 26 and the paper guide 27 are held at a preset facing position, and a certain gap is formed between the platen roller 26 and the paper guide 27.
[0063]
In this state, the driven gear 31 connected to one end of the platen roller 26 is engaged with a driving gear (not shown) arranged on the mounting frame 21 side. Accordingly, when the drive side gear rotates, the platen roller 26 rotates, and the unwinding portion 4a of the roll paper 4 is conveyed in the conveyance direction (arrow direction), and is predetermined by the inkjet head 8 in synchronization with this conveyance operation. The printing operation is performed.
[0064]
(Other embodiments)
The above description relates to an embodiment in which the present invention is applied to an inkjet printer. The present invention can be similarly applied to a print head other than an ink jet head as a print head, for example, a printer provided with a wire dot head.
[0065]
In addition, the above-described inkjet printer is configured to perform printing on cut paper as well as roll paper. However, a printer mounted on a POS terminal or the like that performs printing only on roll paper that is generally used. Of course, the present invention can be similarly applied to the above.
[0066]
【The invention's effect】
As described above, according to the present invention, in a printer having a roll paper loading mechanism configured to move the roll paper feeding roller in conjunction with the opening / closing lid of the roll paper loading unit, the printer is transported via a print position by a print head. A tension applying means capable of applying a tensile force in the transport direction to the print surface portion of the roll paper, and the tension applying means is provided on the roll paper when the roll paper feed roller is in the operating position. A tensile force is applied to the printing surface portion, and the tension is released when the roll paper feed roller is in the retracted position.
[0067]
According to the present invention, since the tensile force along the transport direction always acts on the print surface portion of the roll paper conveyed at the print position, the curvature of this portion of the roll paper is corrected, and the flat print surface A part is formed. Therefore, the gap between the print head and the roll paper print surface at the print position can be kept constant, the print quality deteriorates due to the curvature of the roll paper, the roll paper surface stains occur, the print position It is possible to avoid problems such as jamming of roll paper.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an ink jet printer to which the present invention is applied.
FIG. 2 is an explanatory diagram showing a paper conveyance path in the ink jet printer of FIG. 1;
3 is a configuration diagram showing a configuration of tension applying means for applying a tensile force to the roll paper in the ink jet printer of FIG. 1. FIG.
4 is a configuration diagram showing a modification of the tension applying means in FIG. 3; FIG.
5 is a configuration diagram of the tension applying unit of FIG. 4 when viewed from a direction orthogonal to each other.
6 is a partial perspective view showing a roll paper loading mechanism extracted from the ink jet printer of FIG. 1; FIG.
7 is an explanatory diagram illustrating a state in which a roll paper loading unit of the roll paper loading mechanism in FIG. 6 is closed.
FIG. 8 is an explanatory diagram showing a state after the lock of the cover frame that closes the roll paper loading unit of the roll paper loading mechanism of FIG. 6 is released.
9 is an explanatory view showing a state in which the cover frame of the roll paper loading mechanism of FIG. 6 is opened until it is almost vertical.
10 is an explanatory diagram showing a state in which a roll paper loading unit of the roll paper loading mechanism of FIG. 6 is fully opened.
11 is an explanatory diagram showing a state in which the slide frame is attached to the lid frame in the roll paper loading mechanism of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Inkjet printer 2 Roll paper loading mechanism 3 Cut paper insertion slot 4 Roll paper 4a Roll paper unwinding part 4A Roll body 4B Roll paper printing surface part 5 Cut paper 6 Guide shaft 7 Carriage 8 Inkjet head 10 Ink supply part 11 Printing position 12 Printer body frame 13, 14 Roll body support roller 15 Pressing roller (pressing member)
15a Rotation center shaft 15b Roller body 15c Spring member 16 Pressing roller 16a Rotation center shaft 16b Roller body 16c Spring member 17 Brake roller 17a Rotation center shaft 17b Roller body 17c Pressing mechanism 17d Receiving plate 17e Pressing plate 17f Coil spring 21 Mounting frame 22 Roll Paper loading portion 22b Roll paper loading portion opening 23 Lid frame 24 Shaft 25 defining pivot center Slide frame 25j Connection hole 26 Platen roll 27 Paper guide 27a Paper guide surface 28 Cover frame 28d Connection shaft 29 Link mechanism

Claims (8)

A print head, a roll paper feed roller for transporting the roll paper via a print position by the print head, a roll paper loading unit loaded with the roll paper, and an open / close lid for opening and closing the roll paper loading unit In the printer in which the roll paper feed roller moves to the operating position and the retracted position in conjunction with opening and closing of the opening and closing lid,
Tension applying means capable of applying a tensile force in the transport direction to the print surface portion of the roll paper transported via the print position;
The tension applying means applies a tensile force to the print surface portion of the roll paper when the roll paper feed roller is in the operating position, and the tensile force when the roll paper feed roller is in the retracted position. A printer characterized by canceling. In claim 1,
The roll paper feed roller is attached to the opening / closing lid, and when the opening / closing lid is closed, the operation position is reached.
A paper guide for guiding the roll paper toward the roll paper feed roller is attached to the opening / closing lid,
The printer, wherein the print surface portion of the roll paper is bridged between the paper guide and the roll paper feed roller in a state where the open / close lid is closed. In claim 2,
The printer according to claim 1, wherein the tension applying unit includes a pressing member capable of pressing the roll paper against the paper guide with a predetermined elastic pressing force when the opening / closing lid is closed. In claim 3,
The printer, wherein the pressing member is a rotatable pressing roller, and an outer peripheral surface of the pressing roller is pressed against the paper guide with a roll paper interposed therebetween. In claim 3 or 4,
The tension applying means includes a brake roller disposed at a portion pressed by the pressing member in the paper guide,
This brake roller has a predetermined elastic braking force acting on the rotation in the roll paper conveyance direction,
When the opening / closing lid is closed, a state in which roll paper is sandwiched between the brake roller and the pressing member is formed. In claim 5,
The brake roller includes a roller body that is rotatably supported and a pressing spring that applies a predetermined elastic force to a side surface of the roller body. In any one of claims 1 to 6,
The printer, wherein the print head is one of an inkjet head and a wire dot head. A print head;
  A roll paper loading section in which roll paper is loaded;
  An open / close lid for opening and closing the roll paper loading unit;
  A roll paper feed roller attached to the open / close lid and for transporting the roll paper via a print position by the print head;
  A paper guide attached to the opening / closing lid for guiding the roll paper toward the roll paper feed roller;
  A pressing member capable of pressing the roll paper against the paper guide with a predetermined elastic pressing force in a state where the opening / closing lid is closed;
  The roll paper transported by the roll paper feed roller in a state where the opening / closing lid is closed has a print surface portion of the roll paper spanned between the paper guide and the roll paper feed roller in the transport direction. A printer characterized in that a tensile force is applied to the printer.

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