printer

Abstract

To provide a printer in which storage of a roll sheet is easy, and which can properly support the roll sheet.SOLUTION: A printer 1 in which a storage space 30 is formed for storing a roll sheet R where a hole is formed at the center includes: a roll sheet support body 332 having a protrusion part 3321 entering the hole, capable of changing a state by rotating between a protrusion state where the protrusion part 3321 protrudes in the storage space 30 and a retreat state where the protrusion part 3321 has retreated from the storage space 30, and supporting the roll sheet R in the protrusion state; and a flat surface 330a to be contacted which prevents rotation of the protrusion part 3321 in a predetermined direction by coming into contact with the roll sheet support body 332 in the protrusion state. The roll sheet support body 332 moves by being pushed by the roll sheet R when storing the roll sheet R in the storage space 30, and by moving, the contact with the flat surface 330a to be contacted is released, and it becomes rotatable in a predetermined direction.SELECTED DRAWING: Figure 21

Description

[Technical Field]

[0001] The present invention relates to a printer having a storage space for storing roll paper. [Background technology]

[0002] Printers are known that store roll paper, which is a strip of paper wound into a roll, in a storage space and then pull out the paper from the roll to perform printing (see, for example, Patent Document 1). The printer described in Patent Document 1 rotatably supports the roll paper with a protrusion inserted into a hole formed in the center of the roll paper. This protrusion rotates to change state between a protruding state in which it protrudes into the storage space and a retracted state in which it retracts from the storage space, and is biased by a tension spring to maintain the protruding state when unloaded. When the roll paper is stored in the storage space, the roll paper comes into contact with the protrusion, and a load is applied to the protrusion in the rotational direction, causing the protrusion to rotate against the bias of the tension spring and assume the retracted state. When the hole formed in the center of the roll paper reaches a position facing the protrusion, the protrusion returns to the protruding state and is inserted into the hole.

[0003] In particular, in printers that are expected to use adhesive-coated label paper as paper, a configuration is adopted in which the roll paper is supported by the above-mentioned protrusion so that the roll paper does not come into contact with the wall of the roll paper storage section that defines the storage space.

[0004] According to the printer described in Patent Document 1, when storing roll paper, the protrusion rotates to a retracted state, and then the protrusion is inserted into a hole formed in the center of the roll paper, allowing the protrusion to support the roll paper, thereby making it easier to store roll paper in the printer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-87652 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the printer configuration described in Patent Document 1, the protruding part is kept in a protruding state by a spring, so if any force is applied to the roll paper, the protruding part may retract from the storage space and the roll paper may fall. In response to this, if the spring is made stronger to make it difficult to remove the roll paper, not only would it be more difficult to insert the roll paper into the storage space, but there is also the risk that the protruding part may damage the roll paper when inserting it into the storage space.

[0007] SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to provide a printer that can easily store roll paper and properly support the roll paper. [Means for solving the problem]

[0008] The printer of the present invention that solves the above problems comprises: In a printer having a storage space for storing roll paper with a hole formed in the center, a roll paper support having a protrusion that fits into the hole, the protrusion being able to rotate between a protruding state in which the protrusion protrudes into the storage space and a retracted state in which the protrusion retracts from the storage space, and supporting the roll paper when in the protruding state; a stopper that prevents the protrusion from rotating in a predetermined direction by coming into contact with the roll paper support in the protruding state; The roll paper support is capable of moving linearly, and when the roll paper is stored in the storage space, it is pushed by the roll paper and moves linearly, and by moving linearly, it is released from contact with the stopper and can rotate in the specified direction. Also, In a printer having a storage space for storing roll paper with a hole formed in the center, a roll paper support having a protrusion that fits into the hole, the protrusion being able to rotate between a protruding state in which the protrusion protrudes into the storage space and a retracted state in which the protrusion retracts from the storage space, and supporting the roll paper when in the protruding state; a stopper that prevents the protrusion from rotating in a predetermined direction by coming into contact with the roll paper support in the protruding state; The roll paper support is pushed and moved by the roll paper when the roll paper is stored in the storage space, and as the roll paper support moves, it is released from contact with the stopper and becomes rotatable in the predetermined direction. You may . In this printer, a support guide shaft to which the roll paper support is attached, The roll paper support may be rotatable about the support guide shaft and linearly movable in a guide axis direction along the support guide shaft.

[0009] With this printer, even if force is applied to the roll paper while the roll paper support is supporting the roll paper, the stopper prevents the roll paper support from retracting from the storage space. Therefore, the roll paper will not come off the protrusion and fall. When storing the roll paper, the contact between the roll paper support and the stopper is released, allowing the roll paper support to retract from the storage space, making it easy to store the roll paper in the storage space.

[0010] Here, the predetermined direction may be the direction in which the protrusion rotates downward, and the direction in which the roll paper support moves as it is pushed by the roll paper may be toward the center of rotation of the roll paper support.

[0011] In addition, in this printer, The roll paper support is arranged in the front-to-rear direction of the printer. straight The roll paper may be movable, positioned lower toward the rear, and moved rearward by being pushed by the roll paper.

[0012] With this printer, the roll paper support easily moves backward when pressed by the roll paper, so the contact between the roll paper support and the stopper can be easily released, allowing the roll paper to be smoothly stored in the storage space.

[0013] The printer may also include a cover that covers the top of the storage space when closed and opens the printer at an angle above the front when opened. The roll paper support may also be movable along an axis that extends in a direction inclined relative to the horizontal so that it is positioned downward as it moves toward the rear of the printer.

[0014] Furthermore, in this printer, The apparatus may further include an elastic member that biases the roll paper support so that the roll paper support moves to a position where it abuts against the stopper and assumes the protruding state.

[0015] When the roll paper is stored in the storage space, the biasing force of the elastic member causes the roll paper support to return to the protruding state and abut against the stopper.

[0016] In addition, in this printer, The protrusion is In the protruding state The upper front surface may be formed with a curved surface having a center line extending rearward and upward toward the protruding end.

[0017] When the roll paper is stored in the storage space, the edge of the roll paper comes into contact with the curved surface, and the curved surface is pressed by the roll paper, making it easy for the roll paper support to move. Also, because the part that comes into contact with the roll paper is the curved surface, it is possible to prevent the edge of the roll paper from being damaged. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide a printer that can easily store roll paper and properly support the roll paper. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a perspective view of a printer according to an embodiment of the present invention, seen obliquely from above. [Figure 2] 2 is a perspective view showing the printer shown in FIG. 1 in a cover-open state. [Figure 3] 2 is a cross-sectional view showing a hinge portion on the right side of the printer shown in FIG. 1. FIG. [Figure 4] 2A to 2C are cross-sectional views showing the brake mechanism in stages when the cover of the printer shown in FIG. 1 is opened and closed. [Figure 5] 2 is a cross-sectional view showing a hinge portion on the left side of the printer shown in FIG. 1. [Figure 6]3 is a cross-sectional view showing the state of a torsion coil spring in the printer shown in FIG. 2 with the cover open. [Figure 7] FIG. 3 is a plan view of the printer shown in FIG. 2 with the cover open. [Figure 8] 8 is a cross-sectional view of the first guide taken along line AA in FIG. 7. [Figure 9] 8 is a cross-sectional view of the conveying guide portion, the fixed blade, and the platen unit taken along line BB in FIG. 7. [Figure 10] 3 is a front view of the printer shown in FIG. 2 with the cover open, seen from slightly below. [Figure 11] 1. FIG. 1 is a cross-sectional view similar to FIG. 9, taken along the widthwise center of the conveyance guide portion, the fixed blade, the platen unit, the thermal head unit, and the upper guide of the printer shown in FIG. [Figure 12] 2 is a cross-sectional view of the printer shown in FIG. 1 taken at the center in the width direction. [Figure 13] 2 is a plan view showing a front guide, a pair of side guides, and a drop detector provided in the roll paper compartment of the printer shown in FIG. 1. FIG. [Figure 14] 14(a) is a front view of the guide pinion, guide rack, potentiometer, and side guide provided in the roll paper storage section shown in FIG. 13, as seen from the front, and FIG. 14(b) is a front view of FIG. 14(a) with the potentiometer removed. [Figure 15] 2 is a cross-sectional view of the printer shown in FIG. 1 cut at the center in the width direction, showing the side guide, the front guide, and the drop detection unit as viewed from the side. [Figure 16] FIG. 16 is a cross-sectional view similar to FIG. 15, showing the state in which the roll paper has fallen. [Figure 17] 14(a) is a diagram of the right side guide shown in FIG. 13 as seen from above, and FIG. 14(b) is a diagram of the side guide shown in FIG. 13(a) as seen from the left. [Figure 18] FIG. 17(b) is a perspective view of the support guide shaft, roll paper support, and support tension spring shown in FIG. [Figure 19] FIG. 17B is a cross-sectional view taken along the line DD in FIG. [Figure 20]18 is an explanatory diagram showing the movement of the roll paper support shown in FIG. 17 when the roll paper is removed from the storage space. [Figure 21] 18 is an explanatory diagram showing the movement of the roll paper support shown in FIG. 17 when storing the roll paper in the storage space. [Figure 22] 2A is a bottom view of the thermal head unit and upper frame of the printer shown in FIG. 1, seen from below, and FIG. 2B is an E-E cross-sectional view of FIG. 2A. [Figure 23] 23A and 23B are diagrams illustrating the operation of a head mounting lever performed when attaching or detaching the thermal head unit shown in FIG. 22. [Figure 24] 3 is a side view of the movable blade unit and upper frame of the printer shown in FIG. 2. FIG. [Figure 25] 25 is a view showing how the movable blade unit shown in FIG. 24 is slid and removed from the upper frame. FIG. [Figure 26] (a) is a front view of the fixed blade and lower frame shown in Figure 2, (b) is a side view of the fixed blade and lower frame shown in Figure 2(a), and (c) is a side view similar to Figure 2(b) showing the fixed blade being removed from the lower frame. [Figure 27] 3A to 3C are cross-sectional views of the platen unit and the lower frame, showing how the platen unit of the printer shown in FIG. 2 is removed from the lower frame. DETAILED DESCRIPTION OF THE INVENTION

[0020] An embodiment of the present invention will be described below with reference to the drawings. In the description of this embodiment, a thermal printer is used as an example, in which paper is pulled out from a roll of paper formed by winding up a strip of paper that changes color when heated, and the paper is selectively heated to perform printing and then ejected.

[0021] Figure 1 is a perspective view of a printer corresponding to one embodiment of the present invention, viewed from diagonally above. In Figure 1, the diagonally lower left side is the front side, and the diagonally upper right side is the rear side. Also, in Figure 1, the diagonally lower right side is the left side, and the diagonally upper left side is the right side.

[0022] As shown in FIG. 1, the printer 1 is covered by a housing 2. The housing 2 is composed of a main body case 21 and a cover 22. The main body case 21 and the cover 22 are molded using flame-retardant resin. The main body case 21 covers the lower part of the printer 1. The cover 22 is attached to the main body case 21 by a hinge provided at the rear end thereof so as to be openable and closable.

[0023] FIG. 1 shows the printer 1 in a cover-closed state with the cover 22 closed. In FIG. 1, the top of the printer 1 is covered by the cover 22. A paper discharge opening 1a through which printed paper is discharged is formed on the front of the printer 1, between the main body case 21 and the cover 22. An open lever 220 is provided on the left side of the cover 22. Pulling this open lever 220 forward releases a cover lock mechanism (not shown), allowing the cover 22 to rotate relative to the main body case 21. Lifting the front side of the cover 22 upward causes the cover 22 to rotate around the rear end of the cover 22, opening the diagonally upper-front portion of the printer 1 and exposing the interior of the printer 1.

[0024] Figure 2 is a perspective view showing the printer shown in Figure 1 in an open state. The cover 22 of the printer 1 is configured to be rotatable up to 80 degrees from the closed state around hinges provided on both the left and right sides of the rear end portion. Figure 2 shows the cover 22 opened to 80 degrees. Note that the maximum rotation angle of the cover 22 may be other than 80 degrees.

[0025] As shown in FIG. 2, opening the cover 22 opens the printer 1 diagonally upward, exposing the main case 21, the components inside the cover 22, and the storage space 30 (described below). The main case 21 houses a roll paper compartment 3, a transport guide 4, a platen unit 5, and a fixed blade 6. The roll paper compartment 3, transport guide 4, platen unit 5, and fixed blade 6 are attached to a lower frame 211 made of sheet metal that is fixed to the main case 21. The roll paper compartment 3 defines a storage space 30 for storing roll paper. When the cover is closed, the cover 22 covers the roll paper compartment 3, storage space 30, transport guide 4, platen unit 5, and fixed blade 6 from above. The storage space 30 stores roll paper R (see FIG. 12), which is a roll of strip-shaped paper such as receipt paper or label paper. Label paper includes liner-backed label paper, in which a label is affixed to a strip-shaped backing, and linerless label paper, which has no liner. The printer 1 of this embodiment is compatible with both types of label paper.

[0026] The cover 22 is provided with a head unit 7, a movable blade unit 8, and an upper guide 9. The head unit 7, the movable blade unit 8, and the upper guide 9 are attached to a first upper frame 221 made of sheet metal that is fixed to the cover 22, or to a second upper frame 222 that is fixed to the first upper frame 221.

[0027] Figure 3 is a cross-sectional view showing the right hinge portion of the printer shown in Figure 1. Figure 3 shows the main body case 21, cover 22, and brake mechanism 23 provided on the right hinge portion, with other components omitted from the illustration.

[0028] The main body case 21 and the cover 22 are connected by hinges provided on the left and right sides of their rear ends. As shown in FIG. 3 , at the hinge provided on the right side of the printer 1, a left hinge shaft 213 fixed to the main body case 21 fits into a left hinge cylinder 223 formed on the cover 22. The hinge is also provided with a brake mechanism 23. The brake mechanism 23 has a cylindrical spring 231 fixed to the main body case 21 and a brake cylinder 232 formed on the cover 22. The cylindrical spring 231 is made of resin and has a generally cylindrical shape with sliding portions 231a protruding outward at both the upper and lower ends. Meanwhile, the brake cylinder 232 is cylindrical and covers the outside of the cylindrical spring 231. The brake cylinder 232 has two protruding portions 232a protruding inward at positions 180 degrees apart.

[0029] Figure 4 is a cross-sectional view showing the brake mechanism in stages when the cover of the printer shown in Figure 1 is opened and closed. Figure 4 shows the area around the right hinge, and the hatching that indicates the cross section has been omitted. Figure 4(a) shows the cover closed state, Figure 4(b) shows the cover 22 opened 40 degrees from the closed state, and Figure 4(c) shows the cover open state with the cover 22 opened 80 degrees.

[0030] As shown in FIG. 4(a), in the cover closed state, the sliding portion 231a faces the inner circumferential surface of the brake cylinder 232 except for the protruding portion 232a and does not contact the inner circumferential surface. Similarly, in the cover open state shown in FIG. 4(c), the sliding portion 231a does not contact the inner circumferential surface of the brake cylinder 232. Therefore, in these states, the cylindrical spring 231 maintains its original shape, undeformed by external forces. On the other hand, in the state in which the cover 22 is opened 40 degrees as shown in FIG. 4(b), the two sliding portions 231a come into contact with and are pressed by the inner circumferential surfaces of the two protruding portions 232a, compressing the cylindrical spring 231 in the vertical direction. In this state, friction generated between the sliding portion 231a and the protruding portion 232a brakes the rotation of the cover 22. In this embodiment, when the cover 22 is opened within an angle range of 7 degrees to 75 degrees from the cover closed state, the inner circumferential surface of the sliding portion 231a and the protruding portion 232a are configured to face each other and make contact. Conversely, the inner circumferential surface of the sliding portion 231a and the protruding portion 232a are separated from each other except when the cover 22 is opened to an angle range of 7 degrees to 75 degrees. As a result, no load is applied to the cylindrical spring 231 in either the cover closed state or the cover open state, and therefore the cylindrical spring 231 is less likely to deteriorate. The strength of the brake can be set as desired by changing the shape and material of the sliding portion 231a and the brake cylinder 232, and the range of their contact angles can also be set as desired.

[0031] Fig. 5 is a cross-sectional view showing the left hinge portion of the printer shown in Fig. 1. Fig. 6 is a cross-sectional view showing the state of the torsion coil spring in the printer with the cover open as shown in Fig. 2. Figs. 5 and 6 show the main body case 21, the cover 22, and the torsion coil spring 24 provided in the left hinge portion, and other components are not shown.

[0032] As shown in Figure 5, at the hinge portion provided on the left side of the printer 1, a right hinge shaft 224 formed on the cover 22 fits into a right hinge cylinder 214 formed on the main body case 21. The hinge portion is also provided with a torsion coil spring 24 that urges the cover 22 in the opening direction. The right hinge cylinder 214 is inserted into the coil portion of the torsion coil spring 24. In the cover closed state shown in Figure 5, the torsion coil spring 24 urges the cover 22 in the opening direction, and the torsion angle of the torsion coil spring 24 is at its maximum. The torsion angle of the torsion coil spring 24 in this cover closed state is 62 degrees.

[0033] The biasing force of the torsion coil spring 24 decreases as the open angle of the cover 22 increases, and when the cover 22 is opened to 62 degrees, the torsion angle becomes zero and the biasing force also becomes zero. Therefore, in the cover open state shown in Figure 6, the biasing force of the torsion coil spring 24 is zero. Note that the torsion angle of the torsion coil spring 24 in the cover closed state can be set arbitrarily, and may be set so that the torsion angle remains even in the cover open state.

[0034] In this embodiment, the torsion coil spring 24 is provided on one of the left and right hinge sections, making it easy to open the cover 22 even when a heavy component such as the movable blade unit 8 (see FIG. 2) is attached to the cover 22. The torsion coil spring 24 also prevents the cover 22 from closing forcefully due to the weight of the component attached to the cover 22. Furthermore, the brake mechanism 23 is provided on the other hinge section, which not only further prevents the cover 22 from closing forcefully, but also quickly damps vibrations in the opening and closing direction of the cover 22 when the cover 22 is stopped at an angle between the open and closed states. In addition, the user's operational feel when opening and closing the cover 22 can be improved.

[0035] FIG. 7 is a plan view of the printer shown in FIG. 2 with the cover open.

[0036] As shown in Figure 7, the roll paper compartment 3 has a front guide 31, a slide shaft 32, a pair of left and right side guides 33, and a drop detection unit 34. The pair of left and right side guides 33 are configured to be movable left and right in the printer 1. The configuration of the roll paper compartment 3 will be described in detail later. Hereinafter, the left and right direction of the printer 1 will sometimes be referred to as the width direction.

[0037] The conveying guide unit 4 includes a first guide 41, a second guide 42, and a first paper sensor 43. The first guide 41 and the second guide 42 are made of resin. The first guide 41 is formed with multiple first ribs 41a that are convex upward. The first rib 41a formed in the center of the width direction is slightly shorter in the front-to-rear direction than the other ribs. The second guide 42 is also formed with multiple second ribs 42a similar to the first ribs 41a. The first paper sensor 43 is disposed between the first guide 41 and the second guide 42. The first paper sensor 43 is a reflective photosensor with a light-emitting element and a light-receiving element on the same surface. The first paper sensor 43 is configured to be movable in the width direction, as indicated by the outline arrow. Figure 7 shows the first paper sensor 43 positioned exactly in the center of the width direction.

[0038] FIG. 8 is a cross-sectional view of the first guide taken along line AA in FIG.

[0039] As shown in FIG. 8 , the multiple first ribs 41a each have the same cross-sectional shape. The cross-sectional shape of the first rib 41a is a mountain-like shape, with linear inclined portions on the left and right sides and a very short linear portion extending in the width direction at the tip connected by a curve. However, the cross-sectional shape of the first rib 41a may not have a linear portion at the tip, the inclined portion may be formed in an arc shape, or the entire cross-sectional shape may be formed only in an arc shape. Furthermore, the cross-sectional shape of the first rib 41a may be a generally triangular shape with a pointed tip. Forming multiple first ribs 41a with upwardly convex shapes can prevent paper that tends to stick to the conveying guide section 4, such as linerless label paper without a backing. It also reduces the paper conveying load. The second rib 42a has the same cross-sectional shape as the first rib 41a, so a description of its cross-sectional shape is omitted.

[0040] Fig. 9 is a cross-sectional view of the conveying guide portion, the fixed blade, and the platen unit taken along line BB in Fig. 7. Lower frame 211 is also shown in Fig. 9.

[0041] As shown in FIG. 9 , a slide guide 431 with an inverted L-shaped cross section is provided between the first guide 41 and the second guide 42. The slide guide 431 extends in the width direction. The slide guide is made of a metal plate and has multiple slits 431a aligned in the width direction. The first paper sensor 43 is configured to be movable in the width direction along the slide guide 431. The first paper sensor 43 is provided with a metal sensor leaf spring 432. When the first paper sensor 43 is moved in the width direction, the sensor leaf spring 432 moves in and out of the slit 431a. This provides a clicking sensation when the first paper sensor 43 moves. Furthermore, by having the sensor leaf spring 432 move into the slit 431a, the first paper sensor 43 can be stopped at a desired position and then held in that position, preventing rattling in the width direction.

[0042] The first paper sensor 43 is used as a black mark sensor, a paper end sensor, or a gap sensor. When used as a black mark sensor, the first paper sensor 43 functions as a sensor that optically detects black marks on the back side of the roll paper R (see FIG. 12). A control unit (not shown) of the printer 1 controls the operation of the printer 1 based on the detection results of the black marks. The position in the width direction at which these black marks are placed is not uniform, but varies depending on the width and type of roll paper R. In this printer 1, the first paper sensor 43 is movable in the width direction, so no matter where the black mark is placed in the width direction, the detection position of the first paper sensor 43 can be aligned with that position to detect the black mark.

[0043] As mentioned above, the first paper sensor 43 can also be used as a paper end sensor. A paper end sensor is a sensor that detects the presence or absence of paper passing over the transport guide unit 4. When used as a paper end sensor, the first paper sensor 43 can be moved and positioned inside the paper width, where the paper passes. When used as a paper end sensor, the first paper sensor 43 is usually positioned in the center in the width direction. When using the first paper sensor 43 as a gap sensor, a light receiving element or light emitting element is required in a position opposite the paper path through which the paper passes. This use as a gap sensor will be described later. Whether the first paper sensor 43 functions as a black mark sensor, paper end sensor, or gap sensor can be selected using a DIP switch or memory switch (not shown) provided on the printer 1.

[0044] The platen unit 5 is disposed downstream of the second guide 42 in the paper transport direction. As shown in FIG. 7 , the platen unit 5 includes a platen roller 51, a platen frame 52, and two bearings 53. The platen roller 51 is a silicone rubber roller rotatably supported by the two bearings 53 and rotated by a motor (not shown). Because it is made of silicone rubber, even paper with an exposed adhesive on the underside, such as linerless label paper, does not stick to the platen roller 51. The platen roller 51 may be made of a material other than silicone rubber, but is preferably one with a non-adhesive surface. The motor that rotates the platen roller 51 is a stepping motor, but other motors, such as a DC motor, may be used instead. The motor is fixed to a lower frame 211. A gear train 2111 is attached to the lower frame 211 to transmit the driving force of the motor to the platen roller 51. When the cover 22 is in the closed state, the platen roller 51 is disposed opposite the print head 71 (see FIG. 10), and paper is sandwiched between the print head 71 and the platen roller 51. As the platen roller 51 rotates, the paper sandwiched between the print head 71 and the platen roller 51 is transported downstream in the paper transport direction.

[0045] The platen frame 52 is a resin frame that supports the platen roller 51 via two bearings 53. A plurality of third ribs 52a having the same cross-sectional shape as the first guide 41 are formed on the top surface of the platen frame 52. Oval-shaped holes that penetrate the platen frame 52 in the width direction are formed at the left and right ends of the platen frame 52. The bearing 53 is made of sintered metal and has a cylindrical body and a flange that are integrated together. The cross-sectional shape of the body of the bearing 53 is circular on the inside and oval on the outside, the same shape as the holes formed in the platen frame 52. The tips of the body of each of the two bearings 53 are inserted into holes formed at the left and right ends of the platen frame 52.

[0046] The fixed blade 6 is located downstream of the platen unit 5 in the paper transport direction. The fixed blade 6 is a plate-shaped metal blade with a cutting edge at its upper end. The surface of the fixed blade 6 is fluorine-coated. This makes it difficult for paper with exposed adhesive, such as linerless label paper, to stick to the fixed blade 6. The fixed blade 6 may be surface-treated to impart non-adhesive properties other than fluorine coating, or may be made of a material that is itself non-adhesive. Fixed blade handles 61 are formed on both widthwise ends of the fixed blade 6 for removing the fixed blade 6 from the lower frame 211.

[0047] FIG. 10 is a front view of the printer shown in FIG. 2 with the cover open, seen from slightly below.

[0048] As shown in FIG. 10, the head unit 7 has a print head 71 and a head frame 72. The print head 71 is a so-called thermal head that has multiple heating elements lined up in the left-right direction, which is the width direction of the paper. By selectively activating these multiple heating elements, printing is performed on paper that passes between the print head 71 and the platen roller 51. The head frame 72 is a metal plate to which the print head 71 is fixed. The head frame 72 is used to detachably attach the head unit 7 to the second upper frame 222. The head unit 7 can be removed from the second upper frame 222 by operating a head attachment lever 225 that is rotatably attached to the second upper frame 222.

[0049] The movable blade unit 8 has a movable blade 81, a movable blade frame 82, and two lock pins 83. The movable blade 81 reciprocates relative to the fixed blade 6 (see FIG. 7) when the cover 22 is closed by driving a small DC motor (not shown) provided in the movable blade frame 82. When the movable blade 81 advances toward the fixed blade 6, the portion of the printed paper that was between the movable blade 81 and the fixed blade 6 is cut. The surface of the movable blade 81 is fluorine-coated. This prevents the paper from sticking to the movable blade 81, even when the paper has exposed adhesive, such as linerless label paper. The movable blade 81 may be surface-treated to impart non-adhesive properties other than fluorine coating, or may be made of a non-adhesive material.

[0050] The movable blade frame 82 has a roughly rectangular parallelepiped outer shape. This movable blade frame 82 houses the above-mentioned small DC motor and a drive mechanism that converts the driving force of the small DC motor into movement of the movable blade 81 in the forward and backward directions. The lock pin 83 is fixed to the movable blade frame 82. The two lock pins 83 protrude outward in the width direction from both ends of the movable blade frame 82 in the width direction. The movable blade unit 8 can be slid in the direction of removal from the first upper frame 221 by operating two lock levers 226 attached to the first upper frame 221. When not operated, the lock levers 226 abut against the lock pins 83, preventing the movable blade unit 8 from moving.

[0051] Two guide rollers 91 and a second paper sensor 92 are arranged on the upper guide 9. The two guide rollers 91 are attached so as to be rotatable about their axes, and when the cover 22 is in the closed state, they face the first guide 41 (see FIG. 7) with a gap between them. The second paper sensor 92 is fixed in the center in the width direction. The second paper sensor 92 is a reflective photosensor, just like the first paper sensor 43 (see FIG. 7).

[0052] Figure 11 is a cross-sectional view similar to Figure 9, taken at the center in the width direction of the transport guide unit, fixed blade, platen unit, thermal head unit, and upper guide of the printer shown in Figure 1. In Figure 11, as in Figure 9, the first paper sensor 43 is also located at the center in the width direction.

[0053] As shown in FIG. 11 , when the cover 22 (see FIG. 1 ) is closed, the second paper sensor 92 faces the first paper sensor 43 across the paper path. The paper path extends between the platen unit 5 and the head unit 7 and between the transport guide 4 and the upper guide 9. When the gap sensor is selected using the DIP switch or memory switch, both the first paper sensor 43 and the second paper sensor 92 are used together as transmissive photosensors. Specifically, one of the light-receiving or light-emitting elements of the first paper sensor 43 and the other of the light-receiving or light-emitting element of the second paper sensor 92 are used to detect the intensity of light that passes through paper passing through the paper path and is received by the light-receiving element. By determining the intensity of this light, it is possible to distinguish between labeled portions (portions of the backing paper with a label attached) and unlabeled portions (portions of only the backing paper) of die-cut label paper. In this embodiment, the light-emitting element of the first paper sensor 43 and the light-receiving element of the second paper sensor 92 function as transmissive photosensors. However, the light receiving element of the first paper sensor 43 and the light emitting element of the second paper sensor 92 may be used to function as a transmission type photosensor. Note that the second paper sensor 92 may be used as a paper end sensor instead of the first paper sensor 43.

[0054] In this embodiment, either the light-emitting element or the light-receiving element of the first paper sensor 43 is also used as an element when used as a gap sensor, so the printer 1 can be constructed more inexpensively than if the light-emitting element or the light-receiving element were installed separately from the first paper sensor 43. Also, because the same sensor is used for the first paper sensor 43 and the second paper sensor 92, the number of parts can be reduced and mass production effects can be expected. These factors allow the printer 1 to be constructed more inexpensively.

[0055] Figure 12 is a cross-sectional view of the printer shown in Figure 1, cut at the center in the width direction. Figure 12 also shows roll paper R and paper R1 pulled out from roll paper R. Note that the size of roll paper R varies depending on the type of roll paper R, and the diameter decreases with use, but Figure 12 shows a large-diameter roll paper R at the beginning of use. Also, in Figure 12, the hatching indicating the cross section has been omitted from the detailed view of area C, which is circled and enlarged.

[0056] As shown in FIG. 12, roll paper R consists of a strip of paper R1 wound around a paper tube R0 with a hole in the center. The roll paper R stored in the storage space 30 is supported by a roll paper support 332 (described in detail below) at a distance from the bottom of the roll paper compartment 3. When paper R1 is pulled from the roll R, the inner surface of the hole in the paper tube R0 rubs against the upper surface of the roll paper support 332 as it rotates. The paper R1 pulled from the roll R is guided by the guide roller 91, passes between the transport guide 4 and the upper guide 9, is sandwiched between the platen roller 51 and the print head 71, and is ejected forward through the paper exit 1a. The paper path between the transport guide 4 and the upper guide 9 is slightly inclined relative to the horizontal, but the angle of inclination is approximately 15 degrees, smaller than that of conventional thermal printers. After printing, the paper R1 is transported in a substantially horizontal direction near the platen roller 51 by the third rib 52a formed on the platen frame 52. As a result, the wrap angle θ (contact angle) of the paper R1 on the platen roller 51 is approximately 15 degrees. This wrap angle θ is preferably between 10 degrees and 20 degrees. If it is less than 10 degrees, there is a risk that the paper R1 will be deformed by the downward protruding portion formed on the print head 71. If it exceeds 20 degrees, the paper R1 will stick to the platen roller 51, making it more likely to cause a paper jam, especially if the paper R1 is a type of paper with exposed adhesive on the underside, such as linerless label paper.

[0057] In this embodiment, the wrap angle θ is small, and non-adhesive fixed blade 6, movable blade 81, and platen roller 51 are used, and ribs are formed on the top surfaces of first guide 41 (see FIG. 7), second guide 42, and platen frame 52 (see FIG. 7), so paper R1 can be transported stably regardless of the type of paper R1. This is particularly effective for paper R1 with exposed adhesive on the underside, such as linerless label paper, but it also has the effect of reducing transport resistance even for paper R1 that does not have adhesive on the underside.

[0058] Figure 13 is a plan view showing the front guide, a pair of side guides, and a drop detection unit provided in the roll paper compartment of the printer shown in Figure 1. In Figure 13, roll paper R supported by roll paper support 332 is shown by a two-dot chain line.

[0059] As described above, the roll paper compartment 3 has a front guide 31, a slide shaft 32, a pair of left and right side guides 33, and a drop detection unit 34. The front guide 31 forms the front wall of the roll paper compartment 3 and is made of resin and fixed to the lower frame 211 (see FIG. 2). A scale is printed on the top surface of the front guide 31 to indicate the distance between the side guides 33. A guide pinion 311 (see FIG. 14) and a potentiometer 312 (see FIG. 14(a)), which will be described later, are attached to the front side of the front guide 31. A rail (not shown) is also formed on the front side of the front guide 31 to guide the widthwise movement of a guide rack 335 (see FIG. 14), which will be described later. The slide shaft 32 is a shaft that extends widthwise, and both ends of the slide shaft are held by the front guide 31.

[0060] The pair of left and right side guides 33 are configured to be movable in the width direction along the slide shaft 32. The space between the pair of side guides 33 forms the storage space 30 for storing roll paper R. A guide fixing lever 334 is attached to the left side guide 33 to enable or disable widthwise movement of the side guide 33. The left side guide 33 also has a marking to indicate the distance between the side guides 33. Other than this, the left and right side guides 33 are configured approximately symmetrically with respect to a plane perpendicular to the width direction. For this reason, the following explanation will focus on one of the pair of left and right side guides 33, and explanations of the other side guide 33 regarding common components may be omitted. The side guide 33 includes a side guide main body 330, a support guide shaft 331, a roll paper support 332, a support tension spring 333, and a guide rack 335 (see Figure 14). The support tension spring 333 is an example of an elastic member. The side guide body 330 is made of resin and forms the side wall of the roll paper storage section 3. Attached to this side guide body 330 are a support guide shaft 331, a roll paper support body 332, a support tension spring 333, and a guide rack 335. The roll paper support body 332 has a protrusion 3321. The roll paper support body 332 is molded as a single unit out of resin, such as POM (polyacetal resin) or PC (polycarbonate resin), and the protrusion 3321 is formed as part of the roll paper support body 332. When the roll paper support body 332 supports the roll paper R, the protrusion 3321 protrudes into the storage space 30 and fits into a hole formed in the paper tube R0 of the roll paper R (see Figure 12). Note that it is best to select a hard material as the resin that makes up the protrusion 3321 to increase its wear resistance. This causes friction between the protrusion 3321 and the roll paper R when storing the roll paper R in the storage space 30, but it is possible to prevent this friction from wearing out the protrusion 3321. In addition, by treating the surface of the protrusion 3321 that comes into contact with the roll paper R and reducing the degree of friction, the roll paper R can be stored more smoothly, improving the ease of setting the roll paper R in the printer 1.Furthermore, by treating the surface of the protrusion 3321 that comes into contact with the roll paper R and increasing the degree of friction, the holding force for the roll paper R is improved, making it possible to prevent it from falling unnecessarily.

[0061] Figure 14(a) is a front view of the guide pinion, guide rack, potentiometer, and side guides provided in the roll paper compartment shown in Figure 13, while Figure 14(b) is a front view of Figure 14(a) with the potentiometer removed. Figure 14(a) can also be considered a front view of the components shown in Figure 13 with the front guide 31 removed.

[0062] As shown in FIG. 14(b), a guide rack 335 is screwed to each of the left and right side guide bodies 330. The guide rack 335 moves in the width direction together with the side guide body 330. A guide pinion 311 rotatably attached to the front guide 31 (see FIG. 13) is disposed between the guide racks 335 fixed to the left and right side guide bodies 330. The two guide racks 335 mesh with the guide pinions 311, forming a rack-and-pinion mechanism. This rack-and-pinion mechanism causes one of the pair of side guides 33 to move in the width direction, causing the other side guide 33 to move in the opposite direction. An oval meter fitting cylinder 3351 protruding forward is formed on the guide rack 335. A shaft (not shown) provided on the potentiometer 312 shown in FIG. 14(a) is inserted into this fitting cylinder 3351. The potentiometer 312 is a variable resistor that converts the amount of movement into a voltage, and the voltage changes depending on the position of the axis, i.e., the position of the side guide 33. By obtaining voltage information from this potentiometer 312, the control unit of the printer 1 can grasp the position of the side guide 33.

[0063] Figure 15 is a cross-sectional view of the printer shown in Figure 1 cut at the center in the width direction, showing the side guides, front guide, and drop detection unit from the side. In Figure 15, roll paper R supported by roll paper support 332 is shown by a two-dot chain line.

[0064] As shown in FIG. 15, the fall detection unit 34 has a detection shaft 341, a fall detection lever 342, and a fall detection sensor 343. The detection shaft 341, fall detection lever 342, and fall detection sensor 343 are each located near the bottom of the roll paper compartment 3. The detection shaft 341 is fixed to the front guide 31. The fall detection lever 342 is rotatably attached to the detection shaft 341. The fall detection lever 342 is also biased by a spring (not shown) to rotate clockwise in FIG. 15. A downward-protruding abutment portion 342a is formed on the front portion of the fall detection lever 342. This abutment portion 342a abuts against the bottom surface (not shown) of the roll paper compartment 3, preventing the fall detection lever 342 from rotating clockwise in FIG. 15 beyond the position shown in FIG. When roll paper R is not present in the storage space 30 or when roll paper R is supported by the roll paper support 332, the fall detection lever 342 is in the position (angular position) shown in Figure 15. In this position, the front end of the fall detection lever 342 is located slightly below the detection range of the fall detection sensor 343. The fall detection sensor 343 is a transmissive photosensor that is U-shaped in a plan view and detects whether or not there is an obstruction within the detection range between the U-shaped parts. In the position shown in Figure 15, the front end of the fall detection lever 342 is below the detection range of the fall detection sensor 343, so the fall detection sensor 343 outputs an indication that there is no obstruction.

[0065] Figure 16 is a cross-sectional view similar to Figure 15, showing the state in which the roll paper has fallen. Note that in Figure 16, the roll paper R is shown with a solid line, and the hatching of the roll paper R has been omitted.

[0066] As shown in Figure 16, if roll paper R falls off the roll paper support 332 for some reason, such as a storage error, the weight of the roll paper R causes the fall detection lever 342 to rotate counterclockwise in Figure 16 against a spring (not shown). In the position shown in Figure 16, the front end of the fall detection lever 342 blocks the detection range of the fall detection sensor 343, so the fall detection sensor 343 outputs an indication that an obstruction is present. By receiving an obstruction presence signal from the fall detection sensor 343, the control unit of the printer 1 can recognize that the roll paper R has fallen.

[0067] When the roll paper R is linerless label paper, the outer surface of the roll paper R is typically the printable surface and the inner surface is the adhesive surface. In this case, when paper R1 (see Figure 12) is pulled out from the roll paper R, some of the adhesive on the inner surface may adhere to the printable surface of the roll paper R, leaving a small amount of adhesive on the printable surface. If the roll paper R with the adhesive remaining on the printable surface is rotated in a dropped state, paper dust and other debris accumulated at the bottom of the roll paper storage section 3 may adhere to the adhesive on the printable surface and cause the paper R1 to be transported, resulting in the printing on the adhesive portion being lost. Furthermore, if the roll paper R is rotated in a dropped state, the pulled-out paper R1 may move violently within the storage space 30 and collide with the wall of the roll paper storage section 3, causing large fluctuations in the transport load. In particular, when the roll paper R is linerless label paper, the large transport force required to pull paper R1 from the roll paper R makes the falling roll paper R move violently, easily causing large fluctuations in the transport load. Furthermore, if the roll paper R is label paper, the adhesive may protrude from the sides, and this protruding adhesive may adhere to the side guide body 330 and interfere with the rotation of the roll paper R. This can also cause fluctuations in the transport load. Additionally, if the roll paper R is linerless label paper, the roll paper R may become wavy over time, causing its outer diameter to become inconsistent. If such a roll paper R falls off the roll paper R and paper R1 is pulled out and transported, the transport load will fluctuate. These transport load fluctuations can prevent stable transport of paper R1, resulting in distorted printing. In the worst case, the transport load may exceed the motor's transport force, making it impossible to transport paper R1. Note that if paper R1 is transported using the driving force of a stepping motor, as in this embodiment, exceeding the motor's transport force can cause the motor to lose synchronization and become unable to rotate.

[0068] In this embodiment, the control unit of the printer 1 can recognize that the roll paper R has fallen, and can therefore display an error message or stop the operation of the printer 1. This prevents printing from becoming distorted or preventing the paper R1 (see FIG. 12) from being transported.

[0069] Figure 17(a) is a top view of the right side guide shown in Figure 13, and Figure 17(b) is a left view of the side guide shown in Figure 17(a). Also, Figure 18 is a perspective view of the support guide shaft, roll paper support, and support tension spring shown in Figure 17(a).

[0070] 17(b), a downwardly recessed notch 3301 is formed in the side guide main body 330. A notched step 3302 is formed below the front wall of this notch 3301, protruding rearward and having a flat abutment surface 3302a formed on its upper surface. This abutment surface 3302a corresponds to an example of a stopper.

[0071] The support guide shaft 331 extends within the cutout 3301 so as to span the front and rear walls of the cutout 3301. The support guide shaft 331 extends in the front-to-rear direction, tilted relative to the horizontal so that it is positioned lower toward the rear of the printer. The support guide shaft 331 is tilted 10 degrees relative to the horizontal. Hereinafter, the extension direction of the support guide shaft 331 will be referred to as the guide axis direction. The support guide shaft 331 is attached to the side guide main body 330 by having both ends in the guide axis direction supported by the side guide main body 330. As shown in Figure 18, a support through-hole 332a is formed in the roll paper support 332, and the support guide shaft 331 passes through this support through-hole 332a, attaching the roll paper support 332 to the support guide shaft 331. This allows the roll paper support 332 to rotate about the support guide shaft 331 and move linearly in the guide axis direction along the support guide shaft 331. The support guide shaft 331 rotates around the support guide shaft 331, changing its state between a protruding state in which the protruding portion 3321 protrudes toward the storage space 30 and a retracted state in which the protruding portion 3321 retracts from the storage space 30. Figures 17(a), 17(b), and 18 show the support guide shaft 331 in the protruding state. When the roll paper support 332 supports the roll paper R, the roll paper support 332 is in the protruding state.

[0072] As shown in Figure 17(a), the support tension spring 333 has one end connected to the side guide main body 330 and the other end connected to the roll paper support 332. The support tension spring 333 is connected to the side guide main body 330 and the roll paper support 332 so that the center of the spring is approximately parallel to the support guide shaft 331 when the support guide shaft 331 is in the extended position. When no external force is applied, the support tension spring 333 pulls the roll paper support 332 forward to its forwardmost position and in the extended position. Hereinafter, this position may be referred to as the home position. Figures 17(a), 17(b), and 18 show the roll paper support 332 in this home position. Hereinafter, the guide shaft direction in which the roll paper support 332 approaches the home position may be referred to as the return direction, and the guide shaft direction in which the roll paper support 332 moves away from the home position may be referred to as the removal direction. As shown in Figure 18, the protrusion 3321 has a triangular prism-shaped shaft on the return direction side and a semi-cylindrical shaft on the removal direction side. The shaft is cut diagonally to form a sloped surface CF that slopes toward the removal direction toward the protruding end. The surfaces of the semi-cylindrical section SC, the triangular prism section TP, and the sloped surface CF are each chamfered in a rounded shape. As can be seen from the enlarged views circled in Figures 17(a) and 17(b), the chamfered portion between the triangular prism section TP surface and the sloped surface CF in the protruding state of the roll paper support 332 forms a curved surface with a center line CL extending rearward and upward toward the protruding end. The curved surface formed on the upper front surface is specifically referred to as the functional curved surface RF because it functions when storing roll paper R (see Figure 13). In Figure 18, the functional curved surface RF is indicated by light shading to make it easier to see.

[0073] 18, a stopper abutment portion 3322 is formed at the end of the return direction of the roll paper support 332. The stopper abutment portion 3322 has a flat abutment plane 3322a on the lower part of the roll paper support 332 in the protruding state, and an arc-shaped abutment surface 3322b on the right part in the same state, whose centerline coincides with the support through-hole 332a. The abutment plane 3322a and the abutment arc surface 3322b are continuous.

[0074] FIG. 19 is a cross-sectional view taken along line DD in FIG. 17(b).

[0075] As shown in FIG. 19, the contact plane 3322a of the roll paper support 332 in a protruding state in the basic position abuts against the contacted plane 3302a. Because the contact plane 3322a abuts against the contacted plane 3302a to the left of the center position of the support guide shaft 331 (inside the width of the printer 1), the roll paper support 332 shown in FIG. 19 is prevented from rotating clockwise in FIG. 19 by the contacted plane 3302a. In other words, the roll paper support 332 in a protruding state in the basic position cannot rotate in the direction in which the protruding part 3321 moves downward. However, because the contact plane 3322a is not located to the right of the center position of the support guide shaft 331 (outside the width of the printer 1), the roll paper support 332 in a protruding state in the basic position can rotate counterclockwise in FIG. In other words, the roll paper support 332 in a protruding state in the basic position can rotate in the direction in which the protruding part 3321 moves upward. During this rotation, the roll paper support 332 rotates while the contact arc surface 3322b is in sliding contact with the contacted flat surface 3302a, or while facing the contacted flat surface 3302a with a slight gap therebetween.

[0076] Next, the movement of the roll paper support 332 when removing the roll paper R (see FIG. 13) from the storage space 30 (see FIG. 13) and when storing the roll paper R in the storage space 30 will be described.

[0077] FIG. 20 is an explanatory diagram showing the movement of the roll paper support shown in FIG. 17 when the roll paper is removed from the storage space.

[0078] Figure 20(a1) is a top view of part of the right side guide 33 with the roll paper support 332 protruding in its basic position. Figure 20(a1) shows the position and orientation of the roll paper support 332 when it is supporting roll paper R. Figure 20(b1) is a left-side view of the side guide shown in Figure 20(a1). As described above, when the roll paper support 332 is supporting roll paper R, the protrusion 3321 fits into the hole in the paper tube R0 indicated by the two-dot chain line in Figure 20(b1), and the inner circumferential surface of the paper tube R0 contacts the circumferential surface of the semi-cylindrical section SC. When paper R1 (see Figure 12) is pulled from the roll paper R and transported, the roll paper R is pulled diagonally upward and forward (upper left in Figure 20(b1)). For this reason, when paper R1 is transported, paper tube R0 moves slightly to the upper left in Figure 20(b1), but because the side of protrusion 3321 facing in the direction of removal is made up of semi-cylindrical portion SC, the inner circumferential surface of paper tube R0 still slides against the circumferential surface of semi-cylindrical portion SC, allowing roll paper R to rotate smoothly. Also, in the states of Figures 20(a1) and 20(b1), the abutting plane 3322a and the abutted plane 3302a abut, as shown in Figure 19, and the roll paper support 332 cannot rotate in the direction that would move the protrusion 3321 downward. For this reason, even if a downward force is applied to roll paper R, roll paper R will not lose support from the protrusion 3321 and fall.

[0079] FIG. 20(a2) is a top view of the roll paper support 332 rotating and the protrusion 3321 retracting upward when the roll paper R is removed from the storage space 30, and FIG. 20(b2) is a left-side view of the side guide shown in FIG. 20(a2). To remove the roll paper R, open the cover 22 as shown in FIG. 2, opening the front and upper side of the printer 1 to form an opening, and remove the roll paper R through that opening. When the roll paper R in the storage space 30 is lifted diagonally upward and forward, the lower inner circumferential surface of the paper core R0 first comes into contact with the lower end of the protrusion 3321. The paper core R0 then presses the protrusion 3321, and the roll paper support 332 rotates in the direction that moves the protrusion 3321 upward, as shown in FIGS. 20(a2) and 20(b2), so that the protrusion 3321 retracts from the storage space 30. In the retracted state, the support tension spring 333 is more extended than in the protruding state, so the roll paper support 332 tries to return to the protruding state, but the retracted state is maintained as long as the protruding portion 3321 is in contact with the side of the roll paper R. Then, when the roll paper R is removed from the storage space 30, the roll paper support 332 returns to the protruding state, becoming the state shown in Figures 20(a1) and 20(b1).

[0080] FIG. 21 is an explanatory diagram showing the movement of the roll paper support shown in FIG. 17 when storing the roll paper in the storage space.

[0081] FIG. 21(a1), like FIG. 20(a1), is a top view of a portion of the right side guide 33 with the roll paper support 332 protruding in its basic position. FIG. 21(a1) shows the position and orientation of the roll paper support 332 before the roll paper R is stored in the storage space 30. FIG. 21(b1) is a left-side view of the side guide shown in FIG. 21(a1). In FIGS. 21(a1) and 21(b1), the roll paper R is shown by a two-dot chain line at the moment its outer periphery comes into contact with the protruding portion 3321 when storing the roll paper R. Note that FIG. 21 shows the roll paper R by a two-dot chain line, assuming that the distance between the left and right side guides 33 is appropriately set for the width of the roll paper R to be stored. To store the roll paper R, open the cover 22 as shown in FIG. 2, and store the roll paper R in the storage space 30 through the opening between the main case 21 and the open cover 22. When the paper roll R is brought toward the storage space 30 from above and at an angle to the front, as shown in Figures 21(a1) and 21(b1), the edge of the paper roll R first comes into contact with the functional curved surface RF (see Figures 17 and 18) on the upper front surface of the protrusion 3321. Because the functional curved surface RF is a curved surface centered on the center line (see Figures 17 and 18) mentioned above, when the protrusion 3321 receives a force obliquely downward and rearward from the paper roll R, a force moving it in the removal direction is applied to the paper roll support 332. In addition, because the removal direction is inclined downward as it moves rearward, the force moving the paper roll support 332 in the removal direction becomes stronger. In Figure 21(b1), the direction of the force that the paper roll R applies to the paper roll support 332 is indicated by an open arrow. Furthermore, because the functional curved surface RF is a curved surface with the center line CL as its center and the removal direction is inclined, even if the force received from the roll paper R is directed almost directly downward, a force is applied to the roll paper support 332 to move it in the removal direction. Also, although a force is applied to the roll paper support 332 in a direction that rotates the protrusion 3321 downward, the roll paper support 332 cannot rotate at this point because the contacting plane 3322a and the contacted plane 3302a (both see Figure 19) are in contact. If the part that comes into contact with the edge of the roll paper R were angular, there is a risk that the edge of the roll paper R would be damaged, but because the contacting part is the functional curved surface RF, the roll paper R is less likely to be damaged.

[0082] Figure 21(a2) is a top view of part of the right side guide 33 when the roll paper R has been pushed slightly into the storage space 30 from Figure 21(a1). Figure 21(b2) is a left view of the side guide shown in Figure 21(a2). As shown in Figures 21(a2) and 21(b2), when the protrusion 3321 is pressed by the roll paper R, the roll paper support 332 is pushed by the roll paper R and moves in the removal direction (rearward) against the support tension spring. This releases the contact between the contacting plane 3322a and the abutted plane 3302a (both see Figure 19), allowing the roll paper support 332 to rotate in the direction in which the protrusion 3321 moves downward. The moment the abutting plane 3322a and the abutted plane 3302a separate, the roll paper support 332 begins to rotate in the direction in which the protrusion 3321 moves downward, but Figures 21(a2) and 21(b2) show the roll paper support 332 before it begins to rotate.

[0083] Figure 21(a3) is a top view of part of the right-side side guide 33 when the roll paper R has been pushed further into the storage space 30 from Figure 21(a2). Figure 21(b3) is a left-side view of the side guide shown in Figure 21(a3). As shown in Figures 21(a3) and 21(b3), after the roll paper support 332 moves in the removal direction and the contacting plane 3322a and the contacted plane 3302a (both see Figure 19) separate, the roll paper support 332 rotates in a direction that moves the protruding part 3321 downward. This puts the roll paper support 332 in a retracted state, with the protruding part 3321 retracted from the storage space 30. After that, when the roll paper R is pushed further into the storage space 30 and the protrusion 3321 faces the hole formed in the paper tube R0 of the roll paper R (see Figure 20(b1)), the support tension spring 333 causes the roll paper support 332 to rotate and protrude, moving in the return direction, resulting in the state shown in Figures 20(a1) and 20(b1).

[0084] With the printer 1 of this embodiment, even if a force is applied to the roll paper R in a direction that would cause the roll paper R to fall while it is supported by the roll paper support 332, the contacting plane 3322a and the contacted plane 3302a are in contact, so the protruding part 3321 will not rotate in a direction that would move it downward. This reliably prevents the roll paper R from coming off the protruding part 3321 and falling. Furthermore, even if an upward force is applied to the roll paper R, this is offset by the weight of the roll paper R, so the roll paper R will not move significantly upward unless the force is artificially large. For this reason, it is unlikely that the roll paper support 332 will rotate in a direction that would cause the protruding part 3321 to move upward, except through artificial operation. Furthermore, when the roll paper R is received in the storage space 30, the roll paper support 332 moves in the removal direction, releasing the contact between the contacting surface 3322a and the contacted surface 3302a, so that the roll paper R can be easily stored in the storage space 30 and supported by the roll paper support 332.

[0085] Next, the structure and procedure for attaching and detaching each component unit of the printer 1 will be described in order.

[0086] Fig. 22(a) is a bottom view of the thermal head unit and upper frame in the printer shown in Fig. 1, and Fig. 22(b) is an E-E cross-sectional view of Fig. 22(a). Note that up, down, front, back, left, and right in the explanation and in the figure using Fig. 22 refer to directions in the printer with the cover closed.

[0087] As described above, the head unit 7 has a print head 71 and a head frame 72, and the print head 71 is fixed to the head frame 72. The head unit 7 is detachably attached to the second upper frame 222. A compression spring (not shown) is provided between the head unit 7 and the second upper frame 222, and the front portion of the head unit 7 where the print head 71 is provided is biased downward by the compression spring. When the cover 22 (see FIG. 1) is closed, the print head 71 of the head unit 7 is slightly lifted upward against the compression spring as the print head 71 abuts against the platen roller 51 (see FIG. 2). Figure 22(b) shows the head unit 7 in a state where the cover 22 is closed and the print head 71 is slightly lifted upward. On the other hand, when the cover 22 is open, the front end of the head unit 7 rotates slightly downward around the rear end side from the position shown in Figure 22(b). Two head claws 721 formed at the tip of the head frame 72 are caught in claw receiving portions 2221 formed on the second upper frame 222, thereby preventing further rotation.

[0088] The rear end of the second upper frame 222 is bent downward, and a head mounting pin 2223 is fixed to the bent portion. A resin head mounting lever 225 is rotatably attached to the head mounting pin 2223. A lever cylinder portion 2251 is formed on the head mounting lever 225. The inner hole of the lever cylinder portion 2251 has a diameter slightly larger than the outer periphery of the head mounting pin 2223, and the head mounting pin 2223 is inserted into this hole. A head bent portion 722 is formed on the rear end of the head frame 72, and is bent upward. A head cutout portion 722a (see Figure 23(b1)) is formed on the head bent portion 722, which comes into contact with the outer periphery of the lever cylinder portion 2251 when the head unit 7 is attached.

[0089] Figure 23 is a diagram showing the operation of the head mounting lever performed when attaching or detaching the thermal head unit shown in Figure 22. Note that up, down, front, back, left, and right in the explanation and in the figure using Figure 23 refer to directions in the printer 1 with the cover closed.

[0090] FIG. 23(a1) is a rear view of the head unit 7 and second upper frame 222 shown in FIG. 22(a), and FIG. 23(b1) is an FF cross-sectional view of FIG. 22(a). As shown in FIG. 23(a1), when the head unit 7 is held by the second upper frame 222, the head mounting lever 225 is located on the right side. As shown in FIG. 23(b1), the lever cylinder 2251 has an oval outer surface in cross section cut by two parallel cylinder planes 2251a. The head cutout 722a has an arc-shaped upper side and a linear recess on the lower side. The inner diameter of the arc-shaped portion of the head cutout 722a is slightly larger than the inner diameter of the arc-shaped surface formed on the outer surface of the lever cylinder 2251. The distance between the linear portions of the head cutout 722a is slightly wider than the distance between the two parallel cylindrical planes 2251a formed on the outer peripheral surface of the lever cylindrical portion 2251. When the head mounting lever 225 is on the right side, the arcuate surfaces formed on the outer peripheral surface of the lever cylindrical portion 2251 are located at the left and right ends, and each of the left and right arcuate surfaces is in contact with the arcuate portion of the head cutout 722a. This restricts downward movement of the rear end of the head frame 72, and the head frame 72 is held by the second upper frame 222.

[0091] FIG. 23(a2) shows the state in which the head mounting lever 225 has been rotated counterclockwise from the position shown in FIG. 23(a1), and FIG. 23(b2) is an FF cross-sectional view of that state. As shown in FIG. 23(a2), when the head mounting lever 225 is rotated 90 degrees counterclockwise from the position shown in FIG. 23(a1), the head mounting lever 225 is positioned on the left side. Also, as shown in FIG. 23(b2), the cylindrical portion flat surface 2251a formed on the outer peripheral surface of the lever cylindrical portion 2251 is positioned at the end in the left-right direction, allowing the lever cylindrical portion 2251 to move downward through the linear portion of the head cutout portion 722a. This allows the rear end of the head frame 72 to move downward from the second upper frame 222.

[0092] To remove the head unit 7 from the cover 22 (see FIG. 2), after opening the cover 22, the head attachment lever 225, which is in the state shown in FIG. 23(a1), is rotated 90 degrees to the state shown in FIG. 23(a2). The rear end of the head unit 7 is then moved downward to remove it from the second upper frame 222, and the head claws 721 are separated from the claw receivers 2221. The head unit 7 can then be removed from the cover 22 by disconnecting the connector of the cable (not shown) that connects the print head 71 to the control unit of the printer 1. When attaching the head unit 7 to the second upper frame 222, the procedure for removal is reversed. In this way, the head unit 7 of this embodiment can be easily attached and detached from the cover 22, making maintenance and part replacement easy.

[0093] 24 is a side view of the movable blade unit and the upper frame of the printer shown in FIG. 2. FIG.

[0094] As described above, the movable blade unit 8 can be slid in the direction in which the movable blade unit 8 is removed (to the right in FIG. 24 ) by operating the two lock levers 226 attached to the first upper frame 221. FIG. 24(a) shows a state in which the lock lever 226 abuts against the lock pin 83, restricting the sliding movement of the movable blade unit 8, and FIG. 24(b) shows a state in which the lock lever 226 is operated, enabling the sliding movement of the movable blade unit 8. As shown in FIG. 24(a), the lock lever 226, lock lever shaft 227, and lock spring 228 are attached to the first upper frame 221. The lock lever 226, lock lever shaft 227, and lock spring 228 are attached symmetrically to the left and right of the first upper frame 221, so only the lock levers 226 on the right side of FIG. 24 will be described, and a description of the lock levers on the left side will be omitted. The lock lever shaft 227 is fixed at its base to the first upper frame 221 and protrudes outward in the width direction from the first upper frame 221. The lock lever 226 is rotatably attached to the lock lever shaft 227. One end of a lock spring 228 is connected to the lock lever 226, and the other end is connected to the first upper frame 221. The lock lever 226 is biased by the lock spring 228 to rotate counterclockwise in FIG. 24. A detent 221a protruding outward in the width direction is formed on the first upper frame 221, so the lock lever 226 cannot rotate counterclockwise from the position shown in FIG. 24(a). The movable blade unit 8 shown in FIG. 24(a) is restricted from sliding in the direction to remove the movable blade unit 8 by a lock pin 83 being engaged with a latch portion 226a formed on the lock lever 226.

[0095] 24(b), when the lock lever 226 is operated against the lock spring 228 and rotated clockwise in FIG. 24, the latch portion 226a is released from the lock pin 83, allowing the movable blade unit 8 to slide. In reality, a spring that biases the movable blade unit 8 in the direction of removal is attached to the first upper frame 221, so when the lock lever 226 is operated, the movable blade unit 8 slides slightly in the direction of removal.

[0096] FIG. 25 is a diagram showing how the movable blade unit shown in FIG. 24 is slid and removed from the upper frame.

[0097] FIG. 25(a) shows the movable blade unit 8 after it has been slid and slightly removed, and FIG. 25(b) shows the movable blade unit 8 after it has been removed from the first upper frame 221. After the movable blade unit 8 has been slightly removed as shown in FIG. 25(a), the connector of the cable (not shown) connecting the movable blade unit 8 to the control unit of the printer 1 is disconnected. Then, by further sliding the movable blade unit 8 in the direction of removal, the movable blade unit 8 can be removed from the first upper frame 221 as shown in FIG. 25(b). When attaching the movable blade unit 8 to the first upper frame 221, the procedure for removal is reversed. In this way, the movable blade unit 8 of this embodiment can be easily attached and detached to the cover 22 (see FIG. 2), which improves the workability of maintenance and part replacement.

[0098] Figure 26(a) is a front view of the fixed blade and lower frame shown in Figure 2, Figure 26(b) is a side view of the fixed blade and lower frame shown in Figure 2(a), and Figure 26(c) is a side view similar to Figure 26(b) showing the fixed blade being removed from the lower frame.

[0099] As shown in Figures 26(a) and 26(b), the fixed blade 6 is attached to the upper front portion of the lower frame 211. The lower frame 211 has a U-shape rotated 90 degrees clockwise in a front view, with left and right side plates connected at the bottom. The left and right side plates are shaped approximately symmetrically with respect to a plane perpendicular to the width direction. Therefore, in the following description, only one of the left and right side plates will be described, and descriptions of the other side plate with common shapes may be omitted. The lower end of the fixed blade 6 is inserted into first notches 211a formed in both side plates of the lower frame 211, and upward movement is restricted by fixed blade receiving portions 211b formed in both side plates of the lower frame 211 and shaped like an L rotated approximately 180 degrees. In addition, the upper portion of the fixed blade 6 is biased rearward by a spring (not shown). Fixed blade handles 61 are formed at the upper ends of both widthwise ends of the fixed blade 6, which are used to attach and detach the fixed blade 6.

[0100] By pulling the fixed blade handle 61 forward against the spring, the upper end of the fixed blade 6 disengages from the fixed blade receiving portion 211b, allowing the fixed blade 6 to be removed diagonally upward and forward, as shown in Figure 26(c). When attaching the fixed blade 6 to the lower frame 211, first the lower end of the fixed blade 6 is inserted into the notch 221a, and then the upper end of the fixed blade 6 is fitted into the fixed blade receiving portion 211b. In this way, the fixed blade 6 of this embodiment can be easily attached and detached to the main body case 21 (see Figure 2), making maintenance and part replacement easy to perform.

[0101] Figure 27 is a cross-sectional view of the platen unit and lower frame showing the process of removing the platen unit from the lower frame of the printer shown in Figure 2. Figure 27 is a view of the platen unit 5 and lower frame 211 cut at the widthwise outer side (left side) of the left side plate of the lower frame 211, viewed inward in the widthwise direction.

[0102] As described above, the platen unit 5 includes the platen roller 51 (see FIG. 2), the platen frame 52, and the two bearings 53. The body portions of the two bearings 53 have an oval-shaped outer circumferential surface in cross section, where two parallel body planes 53a form a cylinder. As shown in FIG. 27(c), second notches 211c are formed in both side plates of the lower frame 211. The second notch 211c forms a recess with an arc-shaped lower side and a linear upper side. The inner diameter of the arc-shaped portion of the second notch 211c is slightly larger than the inner diameter of the arc-shaped surface formed on the outer circumferential surface of the body portion of the bearing 53. The distance between the linear portions of the second notch 211c is slightly wider than the distance between the two parallel body planes 53a formed on the outer circumferential surface of the body portion of the bearing 53. As shown in FIG. 27(a), when the platen unit 5 is attached to the lower frame 211, the arcuate surface formed on the outer circumferential surface of the body of the bearing 53 is positioned at the left and right ends. , and the left and right arcuate surfaces thereof are in contact with the arcuate portion of the second notch 211c. This restricts the movement of the platen unit 5, and the platen unit 5 is held by the lower frame 211. Therefore, the platen unit 5 cannot be removed from the lower frame 211. When the fixed blade 6 is attached to the lower frame 211 as shown in FIG. 26(b), the fixed blade 6 prevents the platen frame 52 shown in FIG. 27(a) from rotating.

[0103] To remove the platen unit 5 from the lower frame 211, open the cover 22 and remove the fixed blade 6 using the procedure described above. Then, as shown in FIG. 27(b), rotate the platen frame 52 counterclockwise in FIG. 27. The platen frame 52 abuts against the rotation stopper at the position shown in FIG. 27(b), preventing it from rotating counterclockwise any further. In the state shown in FIG. 27(b), the body plane 53a is parallel to the linear portion of the second notch 211c, allowing the platen unit 5 to be moved diagonally upward and forward. Then, by moving the platen unit 5 diagonally upward and forward, the platen unit 5 is removed from the lower frame 211 as shown in FIG. 27(c). When attaching the platen unit 5 to the lower frame 211, the procedure for removal is reversed. As described above, the platen unit 5 of this embodiment can be easily attached to and detached from the main body case 21 (see FIG. 2), improving workability for maintenance and part replacement.

[0104] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the claims. For example, while the present embodiment describes a printer 1 using a thermal print head, the printer 1 may also use other types of print heads, such as impact dot printers. Furthermore, while the pair of left and right side guides 33 each have a roll paper support 332 that can move in the same way, one of the side guides 33 may have a fixed roll paper support 332. Furthermore, in cases where the roll paper R is expected to be loaded from the front at an angle close to horizontal, the support guide shaft 331 may extend horizontally or may extend in an inclined direction so that it is positioned upward toward the rear. Additionally, while the present embodiment describes an example in which roll paper R with a paper tube R0 is used, roll paper R without a paper tube R0, in which only paper R1 is wound around a central hole, may also be used.

[0105] It should be noted that even if a constituent element is included only in the description of each of the modified examples described above, that constituent element may be applied to other modified examples. [Explanation of symbols]

[0106] 1. Printer 30 Storage space 332 Roll paper support 330a Abutted plane 3321 Protrusion R Roll paper

Claims

1. In a printer having a storage space for storing roll paper with a hole formed in the center, a roll paper support having a protrusion that fits into the hole, the protrusion being able to rotate between a protruding state in which the protrusion protrudes into the storage space and a retracted state in which the protrusion retracts from the storage space, and supporting the roll paper when in the protruding state; a stopper that prevents the protrusion from rotating in a predetermined direction by coming into contact with the roll paper support in the protruding state; A printer characterized in that the roll paper support is capable of moving linearly, and when the roll paper is stored in the storage space, it is pushed by the roll paper and moves linearly, and by moving linearly, it is released from contact with the stopper and can rotate in the specified direction.

2. A support guide shaft to which the roll paper support is attached, 2. The printer according to claim 1, wherein the roll paper support is rotatable about the support guide shaft and linearly movable in a guide axis direction along the support guide shaft.

3. A printer as described in claim 1 or 2, characterized in that the roll paper support is capable of moving linearly in the forward and backward directions of the printer, is positioned lower as it moves toward the rear, and moves rearward when pushed by the roll paper.

4. A printer described in any one of claims 1 to 3, characterized in that it is provided with an elastic member that urges the roll paper support to move to a position where it abuts against the stopper and into the protruding state.

5. A printer as described in Claim 3, characterized in that the protrusion has a curved surface formed on the upper front surface with a center line extending rearward and upward as it approaches the protruding end in the protruding state.

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