Printer unit

Abstract

To provide a printer unit that facilitates installation of a roll paper.SOLUTION: A printer unit 1 comprises a holding part 2 that holds a roll paper R rotatably, and a printing part 3 that performs printing on the roll paper R. The holding part 2 has an arm 4 that has a rotary shaft 5 which is parallel to a width direction of the roll paper R at a base end part in a longitudinal direction and holds the roll paper R at a tip part in the longitudinal direction thereof, and a tensile coil spring 7 as an energizing part that energizes the arm 4 around the rotary shaft 5. The arm 4 is installed rotatably so as to incline from a side in an upright direction in which the tip part is arranged upper than the base end part toward a side at which the printing part 3 is installed, and the tensile coil spring 7 energizes the arm 4 so that the arm 4 turns toward the side in the upright direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a printer unit. [Background technology]

[0002] In conventional printer units that use roll paper as the printing medium, a damper mechanism is provided between the roll paper and the printing unit to suppress fluctuations in the tension of the printing medium as it is pulled from the roll and introduced into the printing unit. With large-diameter roll paper in particular, sudden increases or decreases in printing speed can cause the printing medium to sag, and the increased paper transport load from the time the roll paper starts rotating after stopping can cause the paper to not be transported as intended, resulting in reduced print quality. This damper mechanism reduces the paper transport load from large-diameter roll paper. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-039149 Summary of the Invention [Problem to be solved by the invention]

[0004] When a damper mechanism is installed between the roll paper and the printing unit, the damper position must be changed depending on the paper position. Also, when installing the roll paper, the damper mechanism is located upstream of the printing unit, which makes it difficult to insert the leading edge of the roll paper into the printing unit.

[0005] An object of the present disclosure is to provide a printer unit that allows easy installation of roll paper. [Means for solving the problem]

[0006] A printer unit according to one aspect of an embodiment of the present invention is a printer unit comprising a holding section that rotatably holds roll paper and a printing section that prints on the roll paper, wherein the holding section has a rotation axis at its longitudinal base end that is parallel to the width direction of the roll paper, an arm that holds the roll paper at its longitudinal tip end, and a biasing section that biases the arm around the rotation axis, wherein the arm is installed so as to be rotatable so as to incline from the upright side where the tip end is positioned above the base end toward the side where the printing section is installed, and the biasing section biases the arm to rotate toward the upright side. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a printer unit that allows easy installation of roll paper. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a side view showing a schematic configuration of a printer unit according to an embodiment; [Figure 2] FIG. 1 is a plan view showing a schematic configuration of a printer unit according to an embodiment; [Figure 3] FIG. 10 is a side view illustrating a near-end detection state in the printer unit according to the embodiment. [Figure 4] FIG. 10 is a plan view showing a near-end detection state in the printer unit of the embodiment; [Figure 5] FIG. 10 is a side view showing a first example of a mechanism for adjusting the timing of near-end detection; [Figure 6] FIG. 10 is a side view showing a second example of the mechanism for adjusting the timing of near-end detection; [Figure 7] FIG. 10 is a side view showing a third example of a mechanism for adjusting the timing of near-end detection; [Figure 8] FIG. 10 is a plan view showing a modified example of the holding portion; DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described with reference to the accompanying drawings. To facilitate understanding of the description, the same components in the drawings will be denoted by the same reference numerals as much as possible, and duplicated descriptions will be omitted.

[0010] In the following description, the X, Y, and Z directions are perpendicular to one another. The X direction is the arrangement direction of the printing unit 3 and the holding unit 2. The Y direction is the extension direction of the rotation shaft 5 of the holding unit 2 and the through-hole H of the roll paper R held by the holding unit 2. The Z direction is the erect direction of the wall 11.

[0011] The configuration of a printer unit 1 according to an embodiment will be described with reference to Figures 1 and 2. Figure 1 is a side view showing a schematic configuration of the printer unit 1 according to an embodiment. Figure 2 is a plan view showing a schematic configuration of the printer unit 1 according to an embodiment. Figure 1 is a side view of the printer unit 1 as viewed from the Y negative side. Figure 2 is a plan view of the printer unit 1 as viewed from the Z positive side.

[0012] The printer unit 1 of this embodiment is a printing device that uses roll paper R as a printing medium. As shown in FIGS.

[0013] The holding unit 2 is an element that holds the center of the roll paper R so that the roll paper R can be rotated. The printing unit 3 is an element that prints on the portion of the roll paper R that is pulled out from the roll paper R held by the holding unit 2. In this embodiment, as shown in FIG. 1, the printer unit 1 has a box-shaped base 10 without a top panel, and the holding unit 2 and printing unit 3 are installed on the base 10.

[0014] The holding unit 2 is positioned on the negative X side of the printing unit 3. The outer edge of the roll paper R held in the holding unit 2 is pulled out toward the printing unit 3 (positive X direction) and introduced into the printing unit 3. Inside the printing unit 3, transport elements such as a platen roller (not shown) and printing elements such as a thermal head (not shown) are arranged. The leading edge of the roll paper R is inserted into the gap between the platen roller and the thermal head inside the printing unit 3, and the platen roller moves the roll paper R in and out of the printing unit 3, while the thermal head prints the paper.

[0015] A wall portion 11 is erected in the Z positive direction at a position on the base portion 10 on the X negative side of the holding portion 2. That is, the printing portion 3, the holding portion 2, and the wall portion 11 are arranged in this order from the X positive side to the X negative side.

[0016] Wall 11 is installed so that main surface 11A faces the positive X direction. As shown in Figure 2, main surface 11A of wall 11 is formed so as to extend further outward in the Y direction than roll paper R and holder 2.

[0017] The holding portion 2 has an arm 4 and a tension coil spring 7 (biasing portion).

[0018] The arm 4 is a long member. At its base end in the longitudinal direction, the arm 4 has a rotation shaft 5 that extends parallel to the width direction (Y direction) of the roll paper R, and is rotatable around the rotation shaft 5 as shown by arrow A in Figures 1 and 2. The rotation shaft 5 is installed, for example, below the lower end of the wall 11 as shown in Figure 1, for example, inside the base 10, and is installed in a position where a portion of the X negative direction side overlaps with the wall 11 when viewed from the Z direction as shown in Figures 1 and 2.

[0019] The arm 4 also has a paper roll holding shaft 6 at its longitudinal tip that extends parallel to the width of the paper roll R, and the paper roll holding shaft 6 holds the center of the paper roll R. For example, a through hole H is provided in the center of the paper roll R, and the paper roll holding shaft 6 is formed with a smaller diameter than this through hole H so that it can be inserted into the through hole H. In this case, by inserting the paper roll holding shaft 6 into the through hole H of the paper roll R, the paper roll R is held in the holder 2 so that it can rotate around the paper roll holding shaft 6, i.e., the center of the paper roll R, as its center of rotation.

[0020] The tension coil spring 7 is an example of a biasing portion that biases the arm 4 around the rotation axis 5. In this embodiment, both ends of the tension coil spring 7 are connected to the base end of the arm 4 and a portion of the wall portion 11 on the main surface 11A side, respectively.

[0021] As described above, the main surface 11A of the wall portion 11 is formed to extend further outward in the Y direction than the holding unit 2. As a result, the wall portion 11 is interposed within the rotation range of the arm 4 of the holding unit 2, and when the arm 4 rotates toward the wall portion 11, it abuts against the main surface 11A of the wall portion 11. As a result, the rotation of the arm 4 in the negative X direction relative to the main surface 11A of the wall portion 11 is restricted. Furthermore, as shown in FIG. 2 , the Y direction dimension of the base portion 10 is at least the same as the width direction dimension of the wall portion 11, and therefore the base portion 10 is also interposed within the rotation range of the arm 4 of the holding unit 2. Therefore, when the arm 4 of the holding unit 2 rotates toward the base portion 10, the base portion 10 can restrict the rotation of the arm 4 in the negative Z direction. In other words, the rotation range of the arm 4 is limited between the main surface 11A of the wall portion 11 and the base portion 10. In other words, the arm 4 is rotatably installed so that it tilts from an upright position in which the tip end is positioned vertically above the base end (positive Z direction) in Figure 1 to the side where the printing unit 3 is installed, in an upright position.

[0022] As shown in FIG. 1 , wall 11 is erected at a substantially right angle to base 10, so the rotation range of arm 4 is also limited to a substantially right-angle range between the Z-positive direction and the X-positive direction. Furthermore, tension coil spring 7 is installed so that it is at its natural length or has a minimum amount of extension when arm 4 is in contact with main surface 11A of wall 11 and in a position extending in the Z-positive direction. Therefore, as arm 4 rotates in the X-positive direction within its rotation range, tension coil spring 7 constantly generates a contraction force toward wall 11 to which it is fixed. Furthermore, as the amount of rotation of arm 4 in the X-positive direction increases, the contraction force also gradually increases. Due to the action of tension coil spring 7, arm 4 is urged toward wall 11 around rotation axis 5.

[0023] The tension coil spring 7 may be replaced with another element as long as it can function as a "biasing part that biases the arm 4 of the holding part 2 around the rotation shaft 5." For example, a torsion spring may be provided around the rotation shaft 5, with both ends of the torsion spring fixed to the arm 4 and the wall part 11, respectively.

[0024] In this embodiment, due to the configuration of the holding unit 2 described above, the larger the diameter and mass of the roll paper R, the greater the inclination angle of the arm 4 relative to the upright direction (Z direction) in Figure 1, and the closer it gets to the base 10. On the other hand, the smaller the diameter and mass of the roll paper R, the smaller the inclination angle of the arm 4 relative to the upright direction (Z direction) in Figure 1, and the closer it gets to the main surface 11A of the wall 11.

[0025] In Figure 1, the relatively large-diameter paper roll R1 and the position of the arm 4 holding this paper roll R1 are shown in solid lines, while the relatively small-diameter paper roll R2 and the position of the arm 4 holding this paper roll R2 are shown in dotted lines. In the case of paper roll R1, the gravity of the paper roll R1 causes an external force F1 in the rotation direction that the paper roll holding shaft 6 at the tip of the arm 4 receives. This external force F1 acts on the base 10, i.e., the position of the arm 4, in a counterclockwise direction in Figure 1. When external force F1 acts on the arm 4, the arm 4 rotates more, so the extension of the tension coil spring 7 increases, and the contraction force Fa increases accordingly. The contraction force Fa acts on the wall 11, in the opposite direction from the external force F1, i.e., the arm 4 rotates clockwise in Figure 1. When external force F1 and contraction force Fa act on the arm 4, the contraction force Fa is equal to the external force F1 and the position of the arm 4 is maintained in a balanced rotation position.

[0026] On the other hand, because roll paper R2 has a smaller mass than roll paper R1, the external force F2 acting in the rotation direction on the roll paper holding shaft 6 at the tip of arm 4 due to the gravity of roll paper R2 is smaller than external force F1. The amount of rotation of arm 4 caused by external force F2 acting on arm 4 is also relatively small, so the amount of extension of tension coil spring 7 is also relatively small, and the contraction force Fb corresponding to the amount of extension is also relatively small. When external force F2 and contraction force Fb act on arm 4, contraction force Fb becomes equal to external force F2, and the arm 4 is maintained in a rotational position where they are balanced. Because the amount of rotation of arm 4 caused by external force F2 is smaller than the amount of rotation of arm 4 caused by external force F1, in this embodiment, as the amount of roll paper R used increases and the diameter becomes smaller, the inclination angle of arm 4 with respect to wall 11 decreases, causing arm 4 to gradually approach main surface 11A.

[0027] Thus, in the printer unit 1 of this embodiment, the arm 4 of the holder 2 is rotatably installed so as to tilt from the upright direction (Z direction) in which the tip is positioned vertically above the base end toward the side where the printing unit 3 is installed (X direction). The tension coil spring 7, which serves as the biasing member of the holder 2, biases the arm 4 to rotate toward the upright direction. With this configuration, as described with reference to FIG. 1, the larger the diameter and mass of the roll paper R, the greater the angle of inclination of the arm 4 relative to the upright direction (Z direction) in FIG. 1, and the closer it is to the base 10. On the other hand, the smaller the diameter and mass of the roll paper R, the smaller the angle of inclination of the arm 4 relative to the upright direction (Z direction) in FIG. 1, and the closer it is to the main surface 11A of the wall 11.

[0028] Therefore, in the printer unit 1 of this embodiment, the inclination angle of the arm 4 around the rotation axis 5 changes in accordance with changes in the diameter of the roll paper R held by the holding section 2, thereby changing the distance between the roll paper R and the printing section 3 and the insertion angle of the roll paper R into the printing section 3.

[0029] Furthermore, the arm 4 maintains its position at a position where the gravity of the held roll paper R and the contraction force of the tension coil spring 7 are balanced, but its position is not fixed and it is able to rotate around the rotation axis 5. Therefore, when the printing unit 3 pulls in the roll paper R during a printing operation, the arm 4 rotates counterclockwise and the tension coil spring 7 expands as a result of this rotation, allowing the holding unit 2 to absorb the load on the roll paper R. Similarly, even if the roll paper R is subjected to a sudden external force, for example, the impact can be absorbed by the rotation of the arm 4 and the elastic deformation of the tension coil spring 7, thereby suppressing fluctuations in the tension of the printing medium.

[0030] In this way, the holding unit 2 according to this embodiment has the function of holding the roll paper R and the function of a damper mechanism that suppresses fluctuations in the tension of the print medium. This eliminates the need to place a damper mechanism as a separate element from the holding unit 2 between the roll paper and the printing unit, as in conventional printer units, and therefore eliminates any obstacles that prevent the leading edge of the roll paper R from being inserted into the printing unit 3 when installing the roll paper R in the printer unit 1. As a result, it is easy to install the roll paper R in the printer unit 1. Furthermore, because there is no separate damper mechanism between the holding unit 2 and the printing unit 3, it is possible to increase the storage space for the roll paper R, improving the degree of freedom in the size of the roll paper R that can be used.

[0031] As shown in Figure 2, one arm 4 of the holder 2 is located on one side of the width of the roll paper R (the negative Y side in the example of Figure 2). A roll paper holding shaft 6 is provided to extend in the positive Y direction from the tip of this arm 4. The roll paper holding shaft 6 is formed to be longer than the width dimension of the roll paper R, so that it passes through a through-hole H in the center of the roll paper R and protrudes to the opposite side (positive Y side). In other words, the holder 2 supports the roll paper R from one side in the width direction (negative Y side).

[0032] In this way, when the holder 2 is configured to support the roll paper R from one side in the width direction, the roll paper R can be placed in the holder 2 by fitting the through-hole H of the roll paper R from the free end side of the roll paper holding shaft 6. This makes it even easier to place the roll paper R in the printer unit 1.

[0033] The printer unit 1 of this embodiment further includes a detector 8. The detector 8 is an element for detecting a near-end, which indicates that the roll paper R is about to run out. The detector 8 is installed in the direction in which the arm 4 is urged by the tension coil spring 7, and detects contact of the roll paper R. By detecting contact of the roll paper R, the detector 8 can detect that the roll paper R is near its end.

[0034] In this embodiment, as shown in Figures 1 and 2, the detection unit 8 is attached to the main surface 11A of the wall 11. The installation position of the detection unit 8 is within the range where the roll paper R held by the holder 2 exists when the arm 4 rotates and approaches the wall 11. This allows the detection unit 8 to reliably come into contact with the roll paper R.

[0035] In this embodiment, the detector 8 is, for example, a physical switch. The detector 8 protrudes from the main surface 11A of the wall 11 in the X-positive direction, and has a switch function at the tip on the X-positive side. This allows the detector 8 to detect contact of the roll paper R when the switch function is pressed by the roll paper R.

[0036] Fig. 3 is a side view showing a near-end detection state in the printer unit 1 of the embodiment. Fig. 4 is a plan view showing a near-end detection state in the printer unit 1 of the embodiment. The schematic configurations of Figs. 3 and 4 are the same as Figs. 1 and 2.

[0037] 3 and 4, the paper roll R3 when the near-end is detected is shown by a solid line, and the large-diameter paper roll R1 shown in Figures 1 and 2 is shown by a two-dot chain line. As explained with reference to Figures 1 and 2, in the case of paper roll R1 with a large diameter R1, the gravity acting on the paper roll R1 is relatively large, so the arm 4 of the holder 2 is held in a position with a large angle of inclination. For this reason, as shown in Figures 3 and 4, paper roll R1 is located close to the printing unit 3 and away from the detector 8 on the wall 11.

[0038] As the printing operation of the printing unit 3 using the paper roll R continues and the paper roll R is consumed, the diameter of the paper roll R3 gradually decreases, as shown in FIGS. 3 and 4, and the mass of the paper roll R3 also decreases. As a result, the external force F3 acting on the arm 4 in the rotational direction due to the gravity of the paper roll R3 becomes gradually smaller than in the case of the large-diameter paper roll R1. Therefore, the contraction force Fc of the tension coil spring 7 causes the arm 4 to rotate toward the wall 11. As shown by arrow B in FIGS. 3 and 4, the inclination angle of the arm 4 gradually decreases, moving closer to the wall 11. As a result, the paper roll R held by the holder 2 also moves closer to the wall 11. Eventually, when the external force F3 becomes equal to or smaller than the contraction force Fc, the outer periphery of the paper roll R3 hits the leading edge of the detector 8 on the positive X side, causing the detector 8 to detect contact with the paper roll R3. This allows the printer unit 1 to detect the paper roll R near its end.

[0039] The detection unit 8 only needs to be able to detect contact with the roll paper R, and elements other than a physical switch, such as a touch sensor, may be used. The detection unit 8 may also be an element that can detect the approach of the roll paper R without coming into contact with the roll paper R, such as a proximity sensor. In this case, the detection unit can detect a near-end when the roll paper R approaches within a predetermined distance, for example. Even in this case, the detection unit does not come into contact with the roll paper R, so the same effect as in contact detection can be achieved.

[0040] The detection unit 8 may also be configured to use a transmission sensor or a photosensor to detect contact or proximity of the roll paper R as it passes through the detection range of the sensor.

[0041] Incidentally, in conventional printer units, the mainstream method for detecting the near-end of roll paper R is to place a detection mechanism such as a physical switch against the side of the roll paper R (the end face in the Y direction shown in Figure 2). With this method, the detection mechanism is placed at any position along the diameter of the roll paper R, and when the diameter of the roll paper R becomes small, the detection mechanism no longer comes into contact with the roll paper R, making it possible to detect the near-end.

[0042] In conventional configurations like this, where the detection mechanism is placed against the side of the paper roll to detect the near-end, there is little flexibility in positioning the near-end detection mechanism. Also, even in the case of large diameter roll paper R, which takes a long time to reach the near-end, the detection mechanism is in constant contact with the side of the paper roll, so the side of the paper roll is subjected to a rotational load.

[0043] To address these problems with conventional detection mechanisms, in this embodiment, the detector 8 is separated from the roll paper R until it detects the near-end of the roll paper R, that is, until it comes into contact with the outer surface of the roll paper R. When the printing unit 3 prints, the leading edge of the roll paper R is pulled out as it rotates around the roll paper holding shaft 6. In this embodiment, the detector 8 is out of contact with the roll paper R until the near-end is detected, so the detector 8 does not apply a load to the rotation of the roll paper R during printing. This allows for smoother printing operations and reduces the rotational load on the roll paper R while detecting the near-end. Because the roll paper R and detector 8 are not in constant contact but only come into contact when the near-end occurs, near-end detection can be reliably performed.

[0044] The printer unit 1 may also be configured so that the timing at which the detector 8 can detect the near end can be changed in relation to the tilt angle of the arm. In this configuration, the detector 8 can adjust the distance to the roll paper R. This configuration makes it possible to detect the near end at a timing desired by the user, improving the versatility of the printer unit 1's near end detection.

[0045] Such a configuration example will be described with reference to Figs. 5 to 7. Fig. 5 is a side view showing a first example of a mechanism for adjusting the near-end detection timing. Fig. 5 focuses on the vicinity of the wall portion 11 and the detection portion 8 in the side views of Figs. 1 and 3. In Fig. 5, the near-end detection state exemplified in Fig. 3 is shown by a dotted line.

[0046] 5, the printer unit 1 includes an inclination adjustment unit 12 as an example of a mechanism for adjusting the timing of near-end detection. The inclination adjustment unit 12 is provided at the connection between the wall 11 and the base 10. The inclination adjustment unit 12 has a rotation axis extending along the Y direction, and is rotatable around the Y axis with this rotation axis as the center, and can be fixed at a desired rotation angle by a structure such as screw fastening.

[0047] By providing this type of tilt adjustment unit 12, the wall 11 is configured to be rotatable around an axis parallel to the rotation axis 5 of the holder 2. Then, by rotating the wall 11 from the upright direction (Z direction) toward the side where the printing unit 3 is installed and tilting it relative to the upright direction, the distance between the detector 8 and the roll paper R can be changed. In other words, the distance between the detector 8 and the roll paper R can be adjusted to be shorter, and the timing at which the detector 8 can detect the near-end can be made earlier.

[0048] For example, as shown by arrow C in Figure 5(A), the tilt adjustment unit 12 can be used to rotate the wall 11 by a predetermined amount C in the X positive direction, and fix the posture of the wall 11 in a state where it is tilted relative to the upright direction (Z direction). In this case, the tip of the detection unit 8 moves in the X positive direction, so the timing at which the detection unit 8 can detect the near-end is earlier than in the example of Figure 3. When the detection timing is earlier, the diameter of roll paper R4 at this time is larger than the diameter of roll paper R3, so the near-end can be detected at a timing when more roll paper R is remaining.

[0049] Furthermore, as shown by arrow D in FIG. 5(B), the tilt adjustment unit 12 can be used to rotate the wall 11 in the X-positive direction by a predetermined amount D, which is greater than a predetermined amount C, and fix the posture of the wall 11 in a tilted state relative to the upright direction (Z-direction). In other words, the distance from the detector 8 to the roll paper R can be adjusted to be shorter. In this case, the tip of the detector 8 moves further in the X-positive direction than in the state shown in FIG. 5(A), so the detector 8 can detect the near-end earlier than in the examples shown in FIGS. 3 and 5(A). When the detection timing is even earlier, the diameter of roll paper R5 at this time becomes larger than that of roll paper R4 and roll paper R3, so the near-end can be detected at a time when even more roll paper R is remaining than in the state shown in FIG. 5(A).

[0050] 5, the inclination adjustment unit 12 may have an element such as a ratchet mechanism that can be positioned in units of a predetermined angle (for example, 10°). This makes it easy to adjust the inclination angle of the wall 11, and therefore the near-end detection timing can be easily adjusted in units of a predetermined interval.

[0051] 5, the basic posture of wall 11 may be upright, that is, extending in the Z positive direction with main surface 11A facing the X positive direction, and multiple types of fixed-angle tilt adjusters 12 with different tilt angles in increments of a predetermined angle (for example, 10°) may be provided. In this case, one tilt adjuster that is suitable for the near-end detection timing desired by the user may be selected from the multiple tilt adjusters and installed between base 10 and wall 11.

[0052] Fig. 6 is a side view showing a second example of the mechanism for adjusting the timing of near-end detection. The schematic configuration of Fig. 6 is the same as Fig. 5, and the near-end detection state shown in Fig. 3 is indicated by a dotted line.

[0053] 6, the printer unit 1 includes a support portion 13 and a protrusion portion 14 as an example of a mechanism for adjusting the timing of near-end detection. The support portion 13 and the protrusion portion 14 are provided at the connection portion between the detection portion 8 and the wall portion 11. The support portion 13 is connected at its tip on the positive X direction side to the base portion on the negative X direction side of the detection portion 8, and supports the detection portion 8 while maintaining its orientation in the X direction. The protrusion portion 14 is connected at its tip on the positive X direction side to the base portion on the negative X direction side of the support portion 13, and supports the detection portion 8 and the support portion 13 while maintaining their orientation in the X direction.

[0054] For example, as shown in Figure 6(A), by placing a support 13 between the detector 8 and the wall 11, the tip of the detector 8 can be moved in the positive X direction. This allows the detector 8 to detect the near-end earlier than in the example of Figure 3. When the detection timing is earlier, the diameter of roll paper R4 at this time is larger than the diameter of roll paper R3, so the near-end can be detected at a timing when more roll paper R is remaining.

[0055] Furthermore, as shown in Figure 6(B), by installing a raising portion 14 in addition to the support portion 13 between the detection portion 8 and the wall portion 11, the tip of the detection portion 8 can be moved further in the positive X direction than in the state shown in Figure 6(A). This allows the detection portion 8 to detect the near-end earlier than in the examples shown in Figures 3 and 6(A). When the detection timing is earlier, the diameter of roll paper R5 at this time becomes larger than the diameters of roll paper R4 and roll paper R3, so the near-end can be detected at a time when even more roll paper R is remaining than in the state shown in Figure 6(A).

[0056] 6(B), a configuration may be adopted in which a plurality of raised portions 14 are connected along the X direction. With this configuration, the tip of the detection unit 8 can be moved further in the positive X direction, and the timing at which the detection unit 8 can detect the near-end can be further accelerated.

[0057] 6(B) shows an example of an adjustment mechanism in which the support portion 13 and the raising portion 14 are provided as separate bodies, but the support portion 13 and the raising portion 14 may be integrally formed. That is, a configuration may be adopted in which a plurality of members with different dimensions in the X direction are prepared for installation between the detection portion 8 and the wall portion 11, and any one member is selected according to the desired detection timing and installed between the detection portion 8 and the wall portion 11. With this configuration, the amount of protrusion of the detection portion 8 in the X positive direction relative to the wall portion 11 can be adjusted, as in the example shown in FIG. 6, and the near-end detection timing can be adjusted.

[0058] Figure 7 is a side view showing a third example of the mechanism for adjusting the timing of near-end detection. Figure 7 focuses on the vicinity of wall 11 in the side views of Figures 1 and 3. As shown in Figure 7, detector 8 may be configured to detect the near-end of roll paper R by contacting arm 4 of holder 2 instead of contacting the outer peripheral surface of roll paper R.

[0059] As shown in FIG. 7(A), in the third example, the detector 8 is installed in the range where the arm 4 of the holder 2 is located when it rotates and approaches the wall 11. That is, in the third example shown in FIG. 7, the detector 8 is located further in the negative Z direction than in the examples shown in FIGS. 1 to 6. Therefore, when the roll paper R6 shown in FIG. 7(A) is consumed sufficiently and its diameter becomes small, the arm 4 is pulled toward the wall 11 by the tension coil spring 7 and rotates, causing the arm 4 to hit the tip of the detector 8 on the positive X direction side, which causes the detector 8 to detect contact with the arm 4. As a result, the printer unit 1 can detect when the roll paper R is near its end.

[0060] Also, in the third example shown in Fig. 7, a configuration may be adopted in which a mechanism for adjusting the timing of near-end detection is provided. Figures 7(B) and (C) show an adjustment mechanism similar to that of the second example in Fig. 6, but the adjustment mechanism of the first example in Fig. 5 can also be applied. In Figs. 7(B) and (C), the near-end detection state exemplified in Fig. 7(A) is shown by dotted lines.

[0061] For example, as shown in Figure 7(B), by placing support 13 between detector 8 and wall 11, the tip of detector 8 can be moved in the positive X direction. In other words, the distance between detector 8 and arm 4 can be adjusted to be shorter. This allows detector 8 to detect the near-end earlier than in the example of Figure 7(A). When the detection timing is earlier, the diameter of roll paper R7 at this time is larger than the diameter of roll paper R6, so the near-end can be detected at a timing when more roll paper R is remaining.

[0062] Furthermore, as shown in FIG. 7(C), by installing a support member 13 and a raising member 14 between the detector 8 and the wall 11, the tip of the detector 8 can be moved further in the positive X direction than in the state shown in FIG. 7(B). In other words, the distance between the detector 8 and the arm 4 can be adjusted to be even shorter. This allows the detector 8 to detect the near-end earlier than in the examples shown in FIGS. 7(A) and 7(B). When the detection timing is even earlier, the diameter of the paper roll R8 at this time becomes larger than the diameters of the paper rolls R6 and R7, so the near-end can be detected at a time when there is even more paper roll R remaining than in the state shown in FIG. 7(B). Note that instead of moving the tip of the detector 8 in the positive X direction, the attachment position of the detector 8 can be moved in the negative Z direction.

[0063] 8 is a plan view showing a modified example of the holding portion, the schematic configuration of which is the same as that of the plan view of FIG.

[0064] The holder 2A according to the modified example shown in FIG. 8 has a pair of arms 4A, 4B on either side of the width of the roll paper R, and holds the roll paper R from both sides in the width direction. One arm, 4A, is located on the negative Y side of the roll paper R, and has a roll paper holding shaft 6A at its tip that extends in the positive Y side. A tension coil spring 7A is connected to the base end of arm 4A and wall 11, biasing arm 4A toward wall 11. Similarly, the other arm, 4B, is located on the positive Y side of the roll paper R, and has a roll paper holding shaft 6B at its tip that extends in the negative Y side. A tension coil spring 7B is connected to the base end of arm 4B and wall 11, biasing arm 4B toward wall 11.

[0065] For example, arms 4A and 4B rotate in unison, and roll paper holding shafts 6A and 6B contract when external force is applied. With roll paper holding shafts 6A and 6B contracted, roll paper R is moved from the tip end toward the base end of arms 4A and 4B until through-hole H in roll paper R is positioned on roll paper holding shafts 6A and 6B, at which point roll paper holding shaft 6A is inserted from the negative Y-axis side, and roll paper holding shaft 6B is inserted from the positive Y-axis side. This allows the pair of arms 4A and 4B to hold roll paper R from both sides in the width direction.

[0066] As with the holder 2A of this modified example, by holding the roll paper R from both sides in the width direction with a pair of arms 4A, 4B, the roll paper R can be held more stably, and even when the arms 4A, 4B rotate around the rotation shaft 5, the axis of the roll paper R is prevented from shifting from the Y direction, allowing for more stable movement of the roll paper R. This makes it possible to move the roll paper R more smoothly toward the wall 11 as the roll paper R is consumed, improving the accuracy with which the detector 8 detects when the roll paper R is near its end.

[0067] The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. Design modifications to these specific examples made by a person skilled in the art as appropriate are also included within the scope of the present disclosure as long as they comprise the features of the present disclosure. The elements of the above-described specific examples, as well as their arrangement, conditions, shape, etc., are not limited to those exemplified and can be modified as appropriate. The elements of the above-described specific examples can be combined in various ways as appropriate, as long as no technical contradictions arise. [Explanation of symbols]

[0068] 1 Printer unit 2, 2A holding part 3 Printing Department 4, 4A, 4B arms 7, 7A, 7B Tension coil spring (biasing part) 8. Detection unit 11 Wall 12 Tilt adjustment part R Roll paper

Claims

1. A printer unit including a holding unit that rotatably holds roll paper and a printing unit that prints on the roll paper, The holding portion is an arm having a rotation axis at a base end in a longitudinal direction that is parallel to the width direction of the roll paper, and holding the roll paper at a tip end in the longitudinal direction; a biasing portion that biases the arm around the rotation axis; and the arm is rotatably installed so as to incline from an upright side where the tip end portion is disposed above the base end portion toward a side where the printing unit is installed, The biasing portion biases the arm to rotate in the upright direction. Printer unit.

2. a detector that is installed in a direction in which the arm is urged by the urging unit and that detects the near-end of the roll paper by detecting the approach or contact of the roll paper or the arm; 2. The printer unit according to claim 1.

3. the detection unit is capable of adjusting the distance to the roll paper or the arm; 3. The printer unit according to claim 2.

4. a base on which the rotation shaft is installed; a wall portion provided upright above the base portion and on which the detection unit is installed at a predetermined position; Equipped with the wall portion is configured to be rotatable around an axis parallel to the rotation axis, the wall portion is rotated from the upright direction to the side where the printing portion is installed, and is tilted relative to the upright direction, thereby changing the distance between the detection portion and the roll paper; 4. The printer unit according to claim 3.

5. the arm is provided on one side in the width direction of the roll paper and holds the roll paper from one side in the width direction; The printer unit according to any one of claims 1 to 4.

6. the arm has a pair of arms on both sides of the width direction of the roll paper, and holds the roll paper from both sides in the width direction; The printer unit according to any one of claims 1 to 4.

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