printer

Abstract

To provide a structure for making a print quality in a printer using a roll sheet excellent.SOLUTION: A printer includes: a sheet holding part for rotatably holding a roll sheet obtained by winding a belt-like sheet in a roll state; a printing part for applying printing to the sheet while transporting the sheet; a cushioning part disposed between the sheet holding part and the printing part, and absorbing variations in force required for transportation of the sheet by pressing the sheet with elastic force of an elastic member; a pressing member disposed in the sheet holding part to press the side part of the roll sheet, and disposed so as to be movable in a width direction of the roll sheet; and an adjustment part operated interlocking with the pressing member to change the force of the cushioning part according to a width of the roll sheet.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates to a printer. [Background technology]

[0002] Printers that use roll paper have become widespread. Printers print while pulling out the paper. As the paper is pulled out, the roll paper rotates. If the roll paper is heavy, such as immediately after replacement or refilling, a large amount of tension is required to pull out the paper when printing begins. This tension fluctuates depending on the fluctuations in the inertial force of the roll paper from the start to the end of rotation. Because this tension fluctuation can adversely affect print quality, various structural innovations have been developed to suppress tension fluctuations (e.g., Patent Documents 1 and 2).

[0003] However, because there are many different types of roll paper, it is difficult to realize a structure that appropriately suppresses fluctuations in tension, and improvements are still needed. Summary of the Invention [Problem to be solved by the invention]

[0004] The problem to be solved by the present invention is to provide a structure for improving print quality in a printer that uses roll paper. [Means for solving the problem]

[0005] The printer of the embodiment comprises a paper holding unit that rotatably holds roll paper, which is a strip of paper wound into a roll; a printing unit that prints on the paper while transporting it; a buffer unit that is provided between the paper holding unit and the printing unit and absorbs fluctuations in the force required to transport the paper by pressing the paper with the elastic force of an elastic member; a presser member that is provided on the paper holding unit and presses down on the sides of the roll paper and is movable in the width direction of the roll paper; and an adjustment unit that operates in conjunction with the presser member and changes the force of the buffer unit depending on the width of the roll paper.The adjustment section forms a link structure that transmits movement between the pressing member and the buffer section. do. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a perspective view showing an example of the appearance of a printer 1 according to the first embodiment as seen from the front side. [Figure 2] FIG. 2 is a diagram illustrating an example of the internal configuration and structure of the printer 1. As shown in FIG. [Figure 3] FIG. 3 is a diagram showing the paper holder 6 as viewed from the front. [Figure 4] FIG. 4 is a diagram showing an example of the configuration and structure of the adjustment unit 10. As shown in FIG. [Figure 5] FIG. 5 is a side view illustrating the function of the adjustment unit 10. As shown in FIG. [Figure 6] FIG. 6 is a diagram showing an example of the relationship between damper force, width of roll paper 90, and print quality. [Figure 7] FIG. 7 is a diagram showing an example of the configuration and structure of the adjustment unit 10 in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] (First embodiment) The first embodiment will be described with reference to the drawings. FIG. 1 is a perspective view showing an example of the appearance of a printer 1 according to the first embodiment, as seen from the front side. For ease of explanation, a three-dimensional coordinate system is also shown. The width direction (left-right direction) of the printer 1 is defined as the X-axis direction, the depth direction (front-rear direction) as the Y-axis direction, and the height direction (up-down direction) as the Z-axis direction. The positive direction of the Y-axis is the direction from the front to the back, and a state viewed in the positive Y-axis direction is a front view. The positive direction of the Z-axis is the direction from bottom to top, and a state viewed in the negative Z-axis direction is a plan view. The positive direction of the X-axis is the direction from left to right in a front view. The left and right sides of the printer 1 and each part when viewed from the front (positive Y-axis direction) are sometimes referred to as both sides.

[0008] Printer 1 comprises a housing 2, a display operation unit 3, an open / close button 4, and an issuing port 5. Housing 2 comprises an upper case 21 and a lower case 22. The rear edge of upper case 21 is rotatably attached to lower case 22 by hinge 20, and as the upper case 21 rotates, it opens and closes the opening on the top surface of lower case 22.

[0009] The display operation unit 3 is provided on the top surface of the upper case 21. The display operation unit 3 receives inputs for various operations and displays various information. The open / close button 4 is provided on the front side of the side of the upper case 21 and receives an operation to release the locked state of the locking structure that holds the upper case 21 to the lower case 22.

[0010] The lower case 22 has an upward opening that is closed by the upper case 21. A portion of the front surface of the lower case 22 is formed by the front cover 23. The issuing slot 5 is an opening through which receipts and other paper are issued (discharged), and is located between the upper end of the front cover 23 and the lower end of the front surface of the upper case 21. The front cover 23 has a paper discharge guide 51 at its upper end. The paper discharge guide 51 guides paper discharged from the issuing slot 5.

[0011] 2 is a diagram schematically illustrating an example of the internal configuration and structure of the printer 1. The printer 1 further includes a paper holding unit 6, a printing unit 7, and a buffer unit 8 within the housing 2.

[0012] The paper holding unit 6 stores and rotatably holds roll paper 90, which is a roll of strip-shaped paper 91. Examples of roll paper 90 include receipt rolls and label rolls. A receipt roll is a roll of strip-shaped receipt paper (an example of paper 91). Receipt paper is strip-shaped paper that is printed on and cut into receipts. A label roll is a roll of strip-shaped label paper (an example of paper 91). Label paper includes labels with labels affixed to strip-shaped backing paper, and strip-shaped labels. Labels have an adhesive layer on the back of the printed surface.

[0013] The printing unit 7 prints on the paper 91 while transporting it, and includes a print head 71 and a platen roller 72. The print head 71 is fixed to the inside surface of the upper case 21, and comes into close contact with the platen roller 72 when the upper case 21 closes the opening on the top surface of the lower case 22. The print head 71 is, for example, a thermal head, and includes multiple heating elements arranged in parallel, and prints on the paper 91 sandwiched between it and the platen roller 72 by the heat of the heating elements. The platen roller 72 rotates when driving force is transmitted from a stepping motor, and transports the paper 91 sandwiched between it and the print head 71.

[0014] 3 is a front view of the paper holding unit 6. The paper holding unit 6 has a pair of presser plates 61 and a pair of protrusions 62. The pair of presser plates 61 are an example of a presser member, and are provided with an adjustable spacing between them. They pinch the roll paper 90 between them from both sides, preventing the roll paper 90 from moving widthwise. Protrusions 62 are provided on each presser plate 61 and protrude from the side facing the side edge of the roll paper 90. The protrusions 62 fit into a cylindrical cavity in the center of the roll of paper 90, supporting the roll paper 90 so that it can rotate freely.

[0015] Returning to Figure 2, buffer unit 8 is provided between paper holding unit 6 and printing unit 7 to absorb fluctuations in the force required to transport paper 91, and is equipped with a pressing member 81 and an elastic member 82. Pressing member 81 is a substantially rectangular plate-like member, with one of two opposing sides substantially parallel to the X-axis serving as a rotation axis 811 and the other as a pressing unit 812.

[0016] The rotation shaft 811 is fixed to the housing 2 and serves as the center of rotation of the pressing member 81. The pressing portion 812 moves in accordance with the rotation of the pressing member 81. The pressing portion 812 receives the elastic force of the elastic member 82 and is pressed against the paper 91, thereby pressing the paper 91.

[0017] The pressing direction is approximately perpendicular to the width direction of the paper 91 and intersects with the conveyance direction of the paper 91. In other words, it is desirable that the direction in which the pressing unit 812 presses the paper 91 is such that it does not apply a force that moves the paper 91 in the width direction, and is unlikely to apply a force that promotes or hinders the conveyance of the paper 91.

[0018] In a printer 1 configured as described above, if the roll paper 90 is heavy, for example, because it has just been refilled, a large force is required to rotate the roll paper 90, and therefore a large tension is required to pull the paper 91 out of the platen roller 72 in the printing unit 7. Furthermore, once the roll paper 90 begins to rotate and inertia kicks in, the tension decreases. Furthermore, there is a slight time lag between when printing stops and the paper 91 stops being pulled out, and when the roll paper 90 stops rotating. As a result, the paper 91 slackens on its way to the printing unit 7. As a result, when printing begins, the printer 1 changes states: from a state in which the slack paper 91 is pulled to print (state 1), to a state in which the paper 91 becomes taut as the slack disappears and the tension increases before the roll paper 90 begins to rotate (state 2), and finally to a state in which the roll paper 90 rotates stably (state 3). The buffer unit 8 buffers this change and alleviates any adverse effects on printing accuracy.

[0019] As paper 91 is consumed and the weight of roll paper 90 decreases, the tension in the second state decreases. As this tension decreases, the need for buffer section 8 decreases. For this reason, the force of buffer section 8 is often set to match the maximum weight of roll paper 90.

[0020] The maximum weight of the roll paper 90 corresponds to some extent to the maximum diameter (diameter when unused) and width of the roll paper 90. In other words, the larger the diameter and width of the roll paper 90, the heavier the roll paper 90. However, since there is a limit to the diameter that can be stored in the paper holding unit 6, it can be safely considered that the weight is limited to the amount that can be stored in the paper holding unit 6. On the other hand, the printer 1 can accommodate multiple widths of roll paper 90.

[0021] For this reason, in this embodiment, the adjustment unit 10, which will be described next with reference to Figures 4 and 5, changes the force of the buffer unit 8 depending on the width of the roll paper 90. In more detail, when the paper holding unit 6 is holding a wide roll paper 90, the adjustment unit 10 increases the force of the buffer unit 8, and conversely, when the paper holding unit 6 is holding a narrow roll paper 90, the adjustment unit 10 decreases the force of the buffer unit 8.

[0022] 4A and 4B are diagrams showing an example of the configuration and structure of the adjustment unit 10, with (a) being a rear view and (b) being a plan view. FIG. 5 is a side view illustrating the function of the adjustment unit 10. The printer 1 of this embodiment further includes the adjustment unit 10. The adjustment unit 10 operates in conjunction with the movement of the paper holding unit 6, and adjusts the elastic force that the elastic member 82 applies to the pressing unit 812.

[0023] The paper holding unit 6 includes a rack and pinion 63. The rack and pinion 63 is made up of a pair of rack gears 631, 632 that are parallel to each other and have tooth surfaces facing each other, and a pinion gear 633 that meshes with these rack gears 631, 632.

[0024] A rack gear 631 is attached to one of the pair of presser plates 61, and a rack gear 632 is attached to the other. This allows the rack and pinion 63 to support the pair of presser plates 61 so that they can move toward and away from each other. With this structure, the roll paper 90 is positioned based on the center in the width direction.

[0025] The adjustment unit 10 includes a gear 101, a cam gear 102, an eccentric cam 103, a shaft 104, a rotating plate 105, a rotating shaft 106, and a pressure plate 107. These parts (gear 101, cam gear 102, eccentric cam 103, shaft 104, rotating plate 105, a rotating shaft 106, and a pressure plate 107) form a link structure that transmits the movements of each other.

[0026] The gear 101 is connected to one of the presser plates 61. The gear 101 is located on the opposite side of the presser plate 61 from the rack gear 631. The longitudinal direction of the gear 101 is approximately parallel to the longitudinal direction of the rack gear 631. The gear 101 moves in its own longitudinal direction as the presser plate 61 moves.

[0027] The cam gear 102 is a gear with teeth cut into its cylindrical outer peripheral surface, and meshes with the gear 101. The cam gear 102 rotates (rolls) as the gear 101 moves in accordance with the movement of the presser plate 61.

[0028] The eccentric cam 103 is a cam having an outer circumferential surface that is eccentric from the rotation center of the cam gear 102, and rotates in conjunction with the rotation of the cam gear 102. When the eccentric cam 103 rotates, the position at which the outer circumferential surface of the eccentric cam 103 comes into contact with the shaft 104 changes.

[0029] The shaft 104 is an axial member, and is arranged so that one end (lower end) 1041 contacts the outer peripheral surface of the eccentric cam 103 and the other end (upper end) 1042 contacts one end (first end) 1051 of the rotating plate 105.

[0030] The shaft 104 is arranged with its longitudinal direction aligned along the longitudinal (substantially vertical) direction and rests on the outer peripheral surface of the eccentric cam 103, so that it moves up and down in accordance with the rotation of the eccentric cam 103. In addition, as the shaft 104 moves up and down, one end (first end) 1051 of the rotating plate 105 moves up and down.

[0031] The rotating plate 105 is a plate-shaped member, and is rotatably supported at its center by a rotating shaft 106. This allows the other end (second end) 1052 of the rotating plate 105 to move in the opposite direction to the first end 1051. In other words, when the first end 1051 rises, the second end 1052 falls, and when the first end 1051 falls, the second end 1052 rises.

[0032] A second end 1052 of the rotating plate 105 is connected to the pressing plate 107. The pressing plate 107 moves up and down as the rotating plate 105 rotates in accordance with the vertical movement of the shaft 104.

[0033] The pressing plate 107 sandwiches the elastic member 82 between itself and the pressing portion 812 of the pressing member 81. The pressing plate 107 is positioned so as to press the elastic member 82 from above. The pressing plate 107 moves up and down in accordance with the up and down movement of the second end portion 1052, thereby changing the elastic force that the elastic member 82 applies to the pressing portion 812.

[0034] With the above structure, in the printer 1 of this embodiment, the adjustment unit 10 changes the force (damping force) with which the buffer unit 8 presses the paper 91 depending on the width dimension of the roll paper 90. Figure 6 shows an example of the relationship between damping force, roll paper 90 width, and print quality. The unit of damping force is Newton [N]. Two types of roll paper 90 with the same diameter but different widths were compared as a single example. Below, they will be distinguished as wide and narrow widths. Print quality is shown in three levels, for example, "good," "fair," and "poor."

[0035] Fluctuations in the tension of the paper 91 due to the transition from the first state to the third state described above affect the printing speed (the transport speed of the paper 91). Fluctuations in the printing speed can cause print clogging or stretching in the transport direction of the print. Therefore, fluctuations in tension affect print quality (print accuracy).

[0036] As shown in Figure 6, for a wide paper roll 90, good print quality was obtained when the damper force was 2 to 5 N; a damper force of 1 N was "passable" and a damper force of 0.6 N was "unacceptable." For a narrow paper roll 90, good print quality was obtained when the damper force was 0.6 N; a damper force of 1 to 5 N was "unacceptable." These results suggest that a damper force of 1 N or greater, preferably 2 to 5 N, should be applied to at least a certain width (the wide end in this example) of paper roll 90. These results also suggest that a damper force of about 0.6 N should be applied to at least a certain width (the narrow end in this example), and that a damper force of 1 N or greater is unacceptable.

[0037] As described above, according to this embodiment, the print quality of the printer 1 that uses the roll paper 90 can be maintained at a good level regardless of the width of the roll paper 90.

[0038] (Second embodiment) Next, a second embodiment, which is a modification of the above embodiment, will be described. Since this embodiment is a modification of the first embodiment, the same reference numerals are used for the parts common to the first embodiment, and the description thereof will be omitted.

[0039] 7A and 7B are diagrams showing an example of the configuration and structure of the adjustment unit 10 in the second embodiment, with (a) being a rear view and (b) being a plan view. The paper holder 6 in the first embodiment was positioned based on the center of the width of the paper 91 (center reference), but the paper holder 6 in this embodiment is a one-sided type. In other words, of the pair of pressure plates 611, 612, one pressure plate 611 is fixed as a reference, and only the other pressure plate 612 is movable in the paper width direction. Here, the pressure plate 612 is an example of a pressure member.

[0040] In this configuration, the gear 101 is connected to the pressure plate 612 and moves with the movement of the pressure plate 612. With this configuration, even if the paper holder 6 is biased to one side, the same effect as in the first embodiment can be achieved.

[0041] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, modifications, and combinations can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0042] 1...printer, 10...adjustment section, 101... gear, 102... cam gear, 103... eccentric cam, 104... shaft, 105...rotating plate, 1051...first end portion, 1052...second end portion, 106...rotating shaft, 107...pressure plate, 2...casing, 20...hinge, 21...upper case, 22...lower case, 23...front cover, 3...Display operation unit, 4...Open / close button, 5...Issuing slot, 51...Paper ejection guide, 6...Paper holding section, 61...pressure plate, 611...pressure plate, 612...pressure plate, 62...protrusion, 63...Rack and pinion, 631... rack gear, 632... rack gear, 633... pinion gear, 7...printing unit, 71...print head, 72...platen roller, 8... buffer portion, 81... pressing member, 811... rotating shaft, 812... pressing portion, 82... elastic member, 90...roll paper, 91...paper. [Prior art documents] [Patent documents]

[0043] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-016651 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-213439

Claims

1. a paper holding section that rotatably holds roll paper, which is a strip of paper wound into a roll; a printing unit that prints on the paper while transporting the paper; a buffer section provided between the paper holding section and the printing section, which absorbs fluctuations in the force required to transport the paper by pressing the paper with the elastic force of an elastic member; a presser member provided on the paper holding section to press down on the sides of the roll paper, the presser member being movable in the width direction of the roll paper; an adjustment unit that operates in conjunction with the pressing member and changes the force of the buffer unit according to the width of the roll paper; Equipped with The adjustment section forms a link structure that transmits movement between the pressing member and the buffer section. Printer.

2. the paper holding unit includes a pair of the presser members and a rack and pinion for moving the presser members in directions toward and away from each other; The adjustment portion is interlocked with one of the pressing members. The printer of claim 1 .

3. the paper holding section includes a pressing member that presses one side of the roll paper, and a structure for moving the pressing member in the width direction of the roll paper; The adjustment portion is interlocked with the pressing member. The printer of claim 1 .

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