Printer

Abstract

To provide a printer equipped with a peeling unit, which can be further downsized.SOLUTION: A printer according to an embodiment of the present invention, which can be switched between peeling issuing and continuous issuing, comprises: a conveying roller that conveys a printing medium; a printing head that prints information on a label while interposing the printing medium between the conveying roller and itself; and a peeling unit which can move between a closing position at which at least a portion of the printing head is covered and an opening position at which the printing head is not covered, while holding the peeling roller facing the conveying roller during the peeling issuing. When the peeling unit is at the opening position, a space which the printing head can be attached to and detached from is formed.SELECTED DRAWING: Figure 17

Description

Technical Field

[0001] The present invention relates to a printer.

Background Art

[0002] Generally, a label printer is configured to print desired information on a label while conveying continuous paper by rotating a platen roller with the continuous paper having a plurality of labels temporarily attached to a strip-shaped backing paper sandwiched between a thermal head and the platen roller. Conventionally, a label printer capable of switching between two types of issuing methods, continuous issuing and peeling issuing, is known (for example, Patent Document 1). The continuous issuing method is a method of issuing labels while temporarily attaching them to the backing paper, and the peeling issuing method is a method of issuing labels after peeling them from the backing paper. In the printer described in Patent Document 1, continuous issuing and peeling issuing are switched by moving the backing paper pressing roller support frame of the peeler unit (peeling unit) between a first turning position and a second turning position.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a printer capable of switching between continuous issuing and peeling issuing, for example, when a defect in printing dots occurs, it is necessary to replace the thermal head. However, conventionally, in some cases, tools are required when replacing the thermal head, and it has been difficult to say that the replacement workability is sufficiently good. In particular, in a printer capable of switching between continuous issuing and peeling issuing, since the peeling unit is configured to be movable between a continuous issuing position and a peeling issuing position, the peeling unit may become an obstacle to the replacement work of the thermal head.

[0005] Therefore, an object of the present invention is to improve the workability of replacing a thermal head in a printer capable of switching between continuous printing and peel-and-printing.

Means for Solving the Problems

[0006] One aspect of the present invention is a printer capable of switching between peel-and-printing, in which a label detachably attached to a backing sheet is peeled from the backing sheet and issued, and continuous printing in which the label is issued without peeling from the backing sheet, the printer including: a conveyance roller that conveys the printing medium; a printing head that sandwiches the conveyance roller and the printing medium and prints information on the label; a peeling unit that holds a peeling roller facing the conveyance roller during peel-and-printing and is movable between a closed position that covers at least a part of the printing head and an open position that does not cover the printing head; and when the peeling unit is in the open position, the printer is placed on a horizontal plane when viewed in plan view, the peeling unit and the printing head do not overlap , and is a printer.

Advantages of the Invention

[0007] According to one aspect of the present invention, it is possible to improve the workability of replacing a thermal head in a printer capable of switching between continuous printing and peel-and-printing.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Figure 22

Figure 23

Figure 24

Figure 25

BEST MODE FOR CARRYING OUT THE INVENTION

[0009] [Schematic Configuration of Printer 1] A printer 1 according to an embodiment of the present invention is a label printer configured to be able to switch between continuous printing and peeling printing. Hereinafter, the printer 1 will be described in detail with reference to the drawings. In each figure, for example, as shown in the perspective views of FIGS. 1A and 1B, the directions of up (UP), down (DN), left (LH), right (RH), front (FR), and rear (RR) are defined. However, this definition of the direction is solely for the convenience of explaining the drawings and is not intended to limit the posture of the printer of the present invention during use. In this definition of the direction, the "front-rear direction of the printer" means the front-rear direction of the printer 1. The "width direction of the printer" means the left-right direction or the lateral direction of the printer 1.

[0010] FIG. 1A, FIG. 1B, and FIG. 2 are perspective views of the printer 1 according to the embodiment. FIG. 1A shows the case where the printer cover 3 is in the closed state, and FIGS. 1B and 2 show the case where the printer cover 3 is in the open state. FIG. 1B shows the state where the roll paper R is set, and FIG. 2 shows the state of the roll paper R and the printer 1 before the roll paper R is set.

[0011] As shown in FIG. 1A, in the printer 1, the internal functional components are protected by the main body case 2 and the printer cover 3. On the upper surface of the printer 1, a discharge unit 20 for discharging labels is provided. Note that the printer 1 can be used with the discharge unit 20 side facing upward (in the horizontal position). However, by hooking a belt hook (not shown) provided on the bottom surface of the printer 1 onto the operator's belt or wearing a shoulder belt (not shown) and hanging it on the operator's shoulder, it is also possible to use the printer 1 with the discharge unit 20 side facing sideways (in the vertical holding position). In the main body case 2, in front of the discharge unit 20, a display panel 15 is provided. The display panel 15 may include a touch panel input mechanism for receiving operation inputs by the operator. The display panel 15 is connected to the circuit board inside the printer 1 and outputs an image showing, for example, the operating state of the printer 1 or the user interface related to the operation of the printer 1 based on the display signal supplied from the circuit board.

[0012] Although not shown, inside the printer 1 surrounded by the main body case 2 and the printer cover 3, an internal frame for supporting or holding various functional components is arranged. This internal frame, together with the main body case 2 and the printer cover 3, corresponds to the printer main body.

[0013] The printer cover 3 is configured to be swingable between an open position for opening the inside of the printer 1 and a closed position for closing the inside of the printer 1. When the cover opening button 51b provided on the main body case 2 is operated, as shown in FIG. 1B, the printer cover 3 opens. By opening the printer cover 3, the roll paper storage chamber 9 is exposed. The roll paper storage chamber 9 is a space for storing a roll paper R (an example of a roll body).

[0014] As shown in FIG. 2, the roll paper R is formed by winding a belt-shaped continuous paper P in a roll shape. The continuous paper P has a belt-shaped base paper PM and a plurality of labels PL temporarily attached at predetermined intervals on the base paper PM. The label attachment surface of the base paper PM is coated with a release agent such as silicone so that the label PL can be easily peeled off. Further, position detection marks M indicating the reference positions of the labels PL are formed at predetermined intervals on the back surface of the label attachment surface of the base paper PM. The front side of the label PL is a printing surface on which information is printed, and a thermosensitive coloring layer that colors to a specific color when reaching a predetermined temperature range is formed. The back side of the printing surface is an adhesive surface coated with an adhesive, and the label PL is temporarily attached to the base paper PM by attaching the adhesive surface to the label attachment surface of the base paper PM.

[0015] A pair of roll paper guides 6a are installed in the roll paper storage chamber 9. The pair of roll paper guides 6a are members that support the roll paper R in a rotatable state in contact with both side surfaces of the roll paper R and guide the conveyance of the continuous paper drawn out from the roll paper R, and are preferably movable along the width direction of the roll paper R so that the position can be changed according to the width of the roll paper R.

[0016] As shown in FIG. 2, the printer cover 3 is pivotally supported by the main body case 2 by a hinge 8 so that the printer cover 3 can swing relative to the main body case 2 between an open position and a closed position. The hinge 8 has a hinge shaft 81, and a torsion spring (not shown) for biasing the printer cover 3 from the closed position toward the open position is provided on the hinge shaft 81.

[0017] As shown in FIG. 2, at the tip of the printer cover 3, a platen roller 10 (an example of a conveyance roller) is pivotally supported in a state where it can rotate in both forward and reverse directions. The platen roller 10 is a conveyance means for conveying the continuous paper P drawn from the roll paper R, and is formed in a state of extending along the width direction of the continuous paper P. A gear 10b is connected to one end of the platen shaft 10a of the platen roller 10. This gear 10b engages with a gear 22b disposed inside the main body case 2 when the printer cover 3 is in the closed position, and is mechanically connected to a stepping motor (not shown) for roller drive or the like via the gear 22b.

[0018] As shown in FIG. 2, a peeling bar 12 is installed along the platen roller 10 in the vicinity of the platen roller 10 on the printer cover 3. This peeling bar 12 is a peeling member for peeling the label PL from the backing paper PM, and both ends thereof are fixed to both side walls of the printer cover 3. Note that the peeling bar 12 may be fixed to both ends of the platen shaft 10a. In one embodiment, the cross section of the peeling bar 12 is substantially triangular, but it is not limited thereto, and it may be spherical or elliptical.

[0019] Inside the main body case 2, a platen holding bracket 27 for holding the platen shaft 10a of the platen roller 10 when the printer cover 3 is closed is provided. A thermal head 28 is disposed in front of the platen holding bracket 27.

[0020] The thermal head 28 (an example of a printing head) is, for example, a printing means for printing information such as characters, symbols, figures, or barcodes on the label PL temporarily attached to the backing paper PM conveyed from the roll paper R. The thermal head 28 is provided so as to face the platen roller 10 when the printer cover 3 is in the closed state. As will be described later, a flexible cable that is detachably attached to a circuit board (not shown) is attached to the thermal head 28. The thermal head 28 includes a plurality of heating elements (heating resistors) arranged along the width direction of the continuous paper P, and performs printing by selectively energizing the plurality of heating elements based on a signal transmitted from the circuit board.

[0021] As shown in FIG. 2, a coil spring 55 is disposed in front of the thermal head 28. One end behind the coil spring 55 abuts on the thermal head 28, and the other end in front of the coil spring 55 abuts on the inner frame (see also FIG. 19). The coil spring 55 biases the thermal head 28 toward the platen roller 10 during printing, whereby the thermal head 28 is pressed against the platen roller 10 with an optimum pressure for printing.

[0022] The printer 1 has a peeling unit 4 and performs continuous issuing and peeling issuing by moving the peeling unit 4 between a continuous issuing position and a peeling issuing position. As shown in FIG. 1B, when the printer cover 3 is in the open position, the peeling unit opening button 52b is exposed. By operating the peeling unit opening button 52b, the peeling unit 4 can be operated. FIG. 2 shows the state of the peeling unit 4 when the peeling unit opening button 52b is operated. As will be described later, the peeling unit opening button 52b is operated by an operator when switching from continuous issuing to peeling issuing.

[0023] As shown in FIG. 2, the peeling unit 4 includes a peeling roller cover 41 and a peeling roller holding portion 42 that holds the peeling roller 45. The peeling roller cover 41 is configured to cover the peeling roller holding portion 42 during continuous issuing. The peeling roller cover 41 is pivotally supported by an inner frame in the main body case 2 and swings from a closed position to an open position (the state shown in FIG. 2) in response to the operation of the peeling unit opening button 52b. The peeling roller holding part 42 is pivotally supported by the peeling roller cover 41. During continuous issuing, the peeling roller holding part 42 is housed so as to be folded under the back surface of the peeling roller cover 41. The peeling unit 4 will be described in detail later.

[0024] A sensor 35 is provided on the printer cover 3. The sensor 35 is disposed in the paper feed path until the continuous paper P pulled out from the roll paper R reaches the platen roller 10 when the printer cover 3 is closed, and detects the position of the label PL. Based on the detection result of this sensor 35, it is preferable to control the conveyance amount of the continuous paper P.

[0025] Although not shown, a cutter for cutting the backing paper PM of the continuous paper P after continuous issuing may be provided. When providing a cutter, the cutter is installed in a state of extending along the width direction of the continuous paper P in the discharge unit 20. Further, the peeling bar 12 may function as a cutter.

[0026] [Continuous issuing and peeling issuing] Next, the continuous issuing and peeling issuing of the printer 1 will be described with reference to FIG. 3. The printer 1 is configured to be able to switch between peeling issuing in which a label is peeled off and issued from the backing paper of continuous paper and continuous issuing in which a label is issued without peeling off the label from the backing paper.

[0027] In the case of continuous issuing, a backing paper with the required number of labels attached is prepared in advance, and the label can be peeled off from the backing paper and pasted on site. Therefore, it is suitable when the object to which the label is to be pasted is located at a place away from the printer 1. During continuous issuing, the peeling unit 4 attached to the printer 1 is set to the continuous issuing position.

[0028] On the one hand, in the case of peel issuance, since the labels are discharged one by one in a state of being peeled off from the backing paper, it is suitable when the object to which the label is to be attached is near the operator. At the time of peel issuance, the peel unit 4 attached to the printer 1 is set at the peel issuance position. As a result, when the platen roller 10 is rotated to convey the continuous paper for printing, the backing paper is conveyed while being sandwiched between the peel roller 45 and the platen roller 10, while the printed labels are peeled off from the backing paper one by one and discharged outside the printer 1.

[0029] FIG. 3 is a schematic partial cross-sectional view showing the positional relationship among the peel unit 4, the platen roller 10, the peel bar 12, and the thermal head 28 during continuous issuance and peel issuance. In FIG. 3, only the outer contour lines are shown for the peel roller cover 41 and the peel roller holding portion 42 of the peel unit 4. The outer contour line of the peel roller cover 41 is shown by a dotted line. Also, since the position of the peel roller holding portion 42 is different between continuous issuance and peel issuance, only the peel roller holding portion 42 is hatched. The position of the peel unit 4 during continuous issuance corresponds to the continuous issuance position, and the position of the peel unit 4 during peel issuance corresponds to the peel issuance position.

[0030] As shown in FIG. 3, during continuous issuance, the peel roller holding portion 42 is housed under the peel roller cover 41, whereby the peel roller 45 is at a position separated from the platen roller 10 and does not prevent the discharge of the continuous paper P. The continuous paper P drawn out from the roll paper R is sandwiched between the platen roller 10 and the thermal head 28, and printing is performed on the labels on the continuous paper P.

[0031] When switching from continuous feeding to peeling feeding, the peeling roller holding part 42 is moved to the oscillated position shown in Fig. 3 around the shaft 42a. As shown in Fig. 3, during peeling feeding, the peeling roller 45 is arranged at a position facing the platen roller 10. Even during peeling feeding, the continuous paper P pulled out from the roll paper R is clamped by the platen roller 10 and the thermal head 28, and the point where printing is performed on the label on the continuous paper P is the same as that during continuous feeding. In peeling feeding, the backing paper PM of the continuous paper P pulled out from the roll paper R is rapidly turned at the peeling bar 12, clamped by the platen roller 10 and the peeling roller 45, and discharged. Along with the rapid turning of the backing paper PM at the peeling bar 12, the label PL is peeled off from the backing paper PM and discharged.

[0032] [Opening operation of the printer cover 3] Next, with reference to Figs. 4 and 5, the opening operation of the printer cover 3 will be described. At the same time, the cover opening lever 51 and the peeling unit opening lever 52 will also be described.

[0033] Fig. 4 is a side view of the cover opening lever 51, the peeling unit opening lever 52 (an example of a swinging member), the platen holding bracket 27 (an example of a locking member), and the peeling unit 4 when the printer cover is closed and when the cover opening button is operated. Note that in Fig. 4, as an example, the case where the peeling unit 4 is in the continuous feeding position is shown. As shown in Fig. 4, when viewed in side view, the cover opening lever 51 and the peeling unit opening lever 52 are arranged facing each other in the front-rear direction, while extending in the front-rear direction at different heights, resulting in an arrangement with excellent space efficiency.

[0034] Fig. 5 is a perspective view of the cover opening lever 51, the peeling unit opening lever 52, the platen holding bracket 27, and the peeling unit 4 when the printer cover is closed, as viewed from the rear perspective. In Fig. 5, the peeling unit 4 is omitted from the illustration.

[0035] The cover opening lever 51 has a cover opening button 51b that is exposed to the outside as shown in Fig. 1A. A shaft insertion hole 51a is formed in the cover opening lever 51, and this shaft insertion hole 51a is inserted into a shaft portion 56 (not shown in Fig. 5) provided in the inner frame. Thereby, the cover opening lever 51 is configured to be swingable around the shaft portion 56. As shown in Fig. 5, the cover opening lever 51 has a protrusion 51c that protrudes inward.

[0036] As shown in Fig. 5, the platen holding bracket 27 has a shaft 27a. One end of the shaft 27a is inserted into a boss 52a provided on the peeling unit opening lever 52, and the other end of the shaft 27a is inserted into a boss provided in an inner frame (not shown). Thereby, the platen holding bracket 27 is configured to be swingable around the shaft 27a. Although not visible in Fig. 5, the peeling unit opening lever 52 has an engaging protrusion 523 (see Fig. 4) that protrudes inward. As will be described later, the engaging protrusion 523 is engaged with the peeling roller cover 41 of the peeling unit 4.

[0037] A hole 27c is formed in the side wall of the platen holding bracket 27, and the protrusion 51c of the cover opening lever 51 is inserted into the hole 27c. Here, since the hole 27c is formed larger than the protrusion 51c in a side view (that is, there is play in the hole 27c), the platen holding bracket 27 is swingable. The platen holding bracket 27 swings around the shaft 27a, and the cover opening lever 51 swings around the shaft portion 56 (see Fig. 4), so the swing axes of the two are different. Therefore, by providing play in the hole 27c, it is configured to absorb the difference in the trajectories of the hole 27c and the protrusion 51c due to the difference in the swing axes.

[0038] The lever 52 for releasing the peeling unit is configured to be rotatable (or swingable) around the shaft 27a inserted into the boss 52a. That is, since the platen holding bracket 27 and the lever 52 for releasing the peeling unit share the shaft 27a which is a single swing axis, there is no need to provide a separate swing axis for the lever 52 for releasing the peeling unit, which contributes to space saving and low cost. However, that is not the limit. In another embodiment, separate swing axes may be set for the platen holding bracket 27 and the lever 52 for releasing the peeling unit respectively.

[0039] At a position directly below the button 52b for releasing the peeling unit, a coil spring 53 (an example of a biasing member) is disposed between the lever 52 for releasing the peeling unit and an internal frame (not shown). When the lever 52 for releasing the peeling unit is pushed down (operated) against the restoring force of the coil spring 53, the lever 52 for releasing the peeling unit swings around the shaft 27a (swings clockwise in FIG. 4). As will be described later, with the swing of the lever 52 for releasing the peeling unit, the peeling unit 4 swings via the engaging protrusion 523 and moves from the closed position to the open position. When the downward pressing force on the button 52b for releasing the peeling unit is released, the lever 52 for releasing the peeling unit returns (swings) to the position before being pressed by the restoring force of the coil spring 53.

[0040] The platen holding bracket 27 is biased by a pair of coil springs 29. In FIG. 5, one end of each coil spring 29 is connected to the platen holding bracket 27, and the other end of each coil spring 29 is connected to an internal frame (not shown). When no external force is applied to the platen holding bracket 27, the platen holding bracket 27 is in the position when the printer cover is closed as shown in FIG. 4, and holds the platen shaft 10a in the groove 27b. This position is a lock position for locking the printer cover 3 to which the platen shaft 10a is connected in the closed position.

[0041] Here, when the cover opening button 51b is pressed (operated), the cover opening lever 51 swings around the shaft portion 56 (swings counterclockwise in FIG. 4). As the cover opening lever 51 swings, the protrusion 51c presses against the periphery of the hole 27c of the platen holding bracket 27, causing the platen holding bracket 27 to swing around the shaft 27a (clockwise in FIG. 4) against the restoring force of the coil spring 29. As described above, since the printer cover 3 to which the platen shaft 10a is attached is biased from the closed position toward the open position, when the platen shaft 10a disengages from the groove 27b due to the swing of the platen holding bracket 27, it moves to the open position. The position of the platen holding bracket 27 at this time is the unlocking position that releases the lock in the closed position of the printer cover 3.

[0042] Conversely, when closing the printer cover 3, the pressing force of the operator closing the printer cover 3 presses the platen shaft 10a attached to the printer cover 3 against the inclined top of the platen holding bracket 27 against the restoring force of the coil spring 29. Thereby, the platen holding bracket 27 is swung clockwise in FIG. 4, and the platen shaft 10a is inserted into the groove 27b of the platen holding bracket 27. In the state where the platen shaft 10a is inserted into the groove 27b, the platen holding bracket 27 returns to the locked position when the printer cover is closed shown in FIG. 4 due to the restoring force of the coil spring 29.

[0043] [Separation unit 4] Next, the separation unit 4 will be described with reference to FIGS. 6 to 9.

[0044] FIG. 6 is a perspective view of the separation unit 4 when opened and closed. Note that the separation unit 4 when closed in FIG. 6 shows the case where it is in the continuous printing position. The open position of the separation unit 4 is the position where the separation roller cover 41 is opened following the operation of the separation unit opening button 52b. That is, the open position of the separation unit 4 corresponds to the open position of the separation roller cover 41.

[0045] The open position of the peeling roller cover 41 is a position that opens at least a part inside the printer 1, in other words, at least a part inside the main body case 2, as shown in FIG. 2. For example, as shown in FIG. 2, when the peeling roller cover 41 is in the open position, the coil spring 55 and the flexible cable 57 (see FIG. 21) connected to the thermal head 28 inside the main body case 2 are in an open state. From another perspective, it can be said that the open position of the peeling roller cover 41 is a position that opens the thermal head 28 inside the main body case 2. From yet another perspective, it can be said that the open position of the peeling roller cover 41 is a position that enables the peeling roller cover 41 at that position to be opened when the peeling roller holding portion 42 is at a position facing the back surface of the peeling roller cover 41. As shown in FIG. 6, when the peeling roller cover 41 is in the open position (when open), the peeling roller holding portion 42 is in a state of protruding upward (protruding state).

[0046] The closed position of the peeling unit 4 is a position where the peeling roller cover 41 is closed. That is, the closed position of the peeling unit 4 corresponds to the closed position of the peeling roller cover 41. The closed position of the peeling roller cover 41 is a position that closes at least a part inside the printer 1 that is opened when in the open position, in other words, at least a part inside the main body case 2 that is opened when in the open position. For example, as shown in FIG. 1, when the peeling roller cover 41 is in the closed position, the coil spring 55, the flexible cable 57, etc. are not visible from the outside and are in a closed state. From another perspective, it can be said that the closed position of the peeling roller cover 41 is a position that closes at least a part of the thermal head 28 inside the main body case 2. Furthermore, from another perspective, it can be said that the closed position of the peeling roller cover 41 is a position that holds the peeling roller cover 41 at that position without opening it when the peeling roller holding portion 42 is at a position facing the back surface of the peeling roller cover 41. When the peeling roller cover 41 is in the closed position, the position of the peeling roller holding portion 42 is different between the case of continuous feeding and the case of peeling feeding. As shown in FIG. 6, when the peeling roller cover 41 is in the closed position during continuous issuance (when closed), the peeling roller holding portion 42 is in a state of being accommodated under the peeling roller cover 41 (accommodated state).

[0047] Referring to FIG. 6, the peeling roller cover 41 is a swing member having a pair of shafts 41a (an example of the first shaft) and configured to be swingable around the shafts 41a. The shaft 41a has a circular cross-section and is inserted into a cylindrical portion (not shown) provided in the inner frame and configured to be rotatable. It is preferable that a long hole is formed in the cylindrical portion in the front-rear direction of the printer so that the shaft 41a can be slightly displaced in the front-rear direction of the printer inside. Thereby, when the shaft 41a is inserted into the cylindrical portion, play can be provided in the front-rear direction of the printer, and the impact resistance against the drop of the printer 1 or the like can be improved. Note that the direction of the long hole formed in the cylindrical portion is not limited to the front-rear direction of the printer, and can be set in any direction within a plane orthogonal to the left-right direction of the printer 1, such as the up-down direction of the printer 1.

[0048] The peeling roller cover 41 extends in the same direction as the direction in which the platen roller 10 extends. The peeling roller cover 41 has a front surface 411 and a back surface 412. The front surface 411 is the surface that is exposed when the peeling roller cover 41 is in the closed position. A recess is formed in the back surface 412 so that the peeling roller holding portion 42 can be accommodated. Conversely, the front surface 411 has a shape that bulges in the center in the front-rear direction, which is convenient when a cutter is provided in the discharge portion 20 or when cutting the backing paper. An engagement hole 415 is formed in the peeling roller cover 41 in the vicinity of the shaft 41a. As will be described later, an engagement protrusion 523 of the peeling unit opening lever 52 is inserted into the engagement hole 415.

[0049] A pair of U-shaped grooves 413 (an example of a contact portion) may be provided on the side portion of the peeling roller cover 41. The U-shaped groove 413 abuts against a protrusion 26 (see FIG. 18) formed on the inner frame when the shaft 41a is in the closed position. The U-shaped groove 413 functions as a vertical positioning of the peeling unit 4 by abutting against the protrusion 26. In a state where the U-shaped groove 413 abuts against the protrusion 26, a predetermined gap is provided between the peeling unit 4 and the thermal head 28. Therefore, it is possible to surely prevent the peeling unit 4 and the thermal head 28 from interfering with each other. As described above, the shaft 41a of the peeling unit 4 is preferably inserted into a long hole in the front-rear direction of the printer, which is formed in the cylindrical portion of the inner frame, thereby providing play in the front-rear direction of the printer. At this time, the U-shaped groove 413 prevents the positional deviation of the peeling unit 4 (peeling roller cover 41) in the front-rear direction of the printer due to the play of the shaft 41a inserted into the long hole by abutting against and engaging with the protrusion 26 (see FIG. 18) (that is, it functions as a positioning of the peeling unit 4 in the front-rear direction of the printer).

[0050] Note that it is not essential to provide the U-shaped groove 413 and the protrusion 26. It is sufficient that a part of the peeling unit 4 and the inner frame can abut against each other while ensuring a gap between the peeling unit 4 and the thermal head 28, and the shape of the abutting portion can be appropriately formed. Further, instead of such an abutting structure, for example, the vertical positioning of the peeling unit 4 can also be performed by restricting the movable range of the shaft 41a of the peeling roller cover 41.

[0051] On the surface 411 of the peeling roller cover 41, a peeling sensor 47 is disposed. The peeling sensor 47 is a light reflection type sensor that detects the presence or absence of a label peeled off at the time of peeling issuance. In FIG. 3, the label PL peeled off by the peeling bar 12 is controlled to be conveyed so that a part on the upstream side in the conveyance direction stops near the peeling bar 12. Thus, the peeled label PL stays on the peeling bar 12 due to its adhesive force, and the presence or absence of this label PL is detected by the peeling sensor 47. When the operator takes out the peeled label, it is detected by the peeling sensor 47 that there is no label PL, and control is performed to issue the next label.

[0052] Referring to FIG. 6, the peeling roller holder 42 is a member that holds the peeling roller 45. Similar to the peeling roller cover 41, the peeling roller holder 42 extends in the same direction as the direction in which the platen roller 10 extends. The peeling roller holder 42 is configured such that a pair of shafts 42a are disposed inside a pair of shafts 41a of the peeling roller cover 41 so as to be accommodatable under the back surface 412 of the peeling roller cover 41, and the width of the peeling roller holder 42 is narrower than the width of the peeling roller cover 41.

[0053] The peeling roller holder 42 is a swing member having a pair of shafts 42a (an example of the second shaft) and configured to be swingable around the shafts 42a. The pair of shafts 42a are pivotally supported by the peeling roller cover 41 at positions spaced apart from the shafts 41a. The peeling roller 45 is disposed at the tip of an arm 421 extending from the shaft 42a. Therefore, as shown in FIG. 6, when the peeling unit 4 is opened, the peeling roller 45 protrudes greatly upward with reference to the shaft 41a.

[0054] That is, the peeling roller holding part 42 is swingable between a housed position (an example of the first position of the peeling roller holding part) where the peeling roller 45 is housed under the peeling roller cover 41 and a protruding position (an example of the second position of the peeling roller holding part; the position at the time of opening in FIG. 6) where the peeling roller 45 is not covered by the peeling roller cover 41. The housed position of the peeling roller holding part 42 is also a position facing the back surface 412 of the peeling roller cover 41 and is also a position covered by the peeling roller cover 41. When housing the peeling roller holding part 42, the peeling roller holding part 42 is swung around the shaft 42a to the back surface 412 of the peeling roller cover 41, and further, the entire peeling roller cover 41 and the peeling roller holding part 42 are swung around the shaft 41a. Thereby, the peeling roller holding part 42 is compactly housed under the peeling roller cover 41 in a folded manner.

[0055] On the other hand, when the peeling roller cover 41 is in the open position, the peeling roller holding part 42 is swingable between the housed position and the protruding position. Further, since the peeling roller holding part 42 is biased by the coil spring 43 from the housed position toward the protruding position as will be described later, as soon as the peeling roller cover 41 moves from the closed position to the open position, the peeling roller holding part 42 moves so as to pop out from the housed position toward the protruding position. Thereby, the operator can immediately switch from continuous feeding to peeling feeding. Also, when the peeling roller holding part 42 is in the protruding position, the peeling roller 45 protrudes highly, and thereby, when setting the peeling unit 4 to the peeling feeding position, the peeling roller 45 can be moved far away.

[0056] A pair of arms 421 extend starting from a pair of shafts 42a. At the tips of the pair of arms 421, a shaft 45a for rotating the peeling roller 45 and the auxiliary roller 46 is arranged. The diameter of each auxiliary roller 46 is smaller than the diameter of the peeling roller 45. By providing the auxiliary rollers 46 on both sides of the peeling roller 45, when peeling and issuing a wide label, the wide backing paper can be smoothly discharged. That is, if there is no auxiliary roller 46, the wide backing paper will move in the width direction (left - right direction), but by providing the auxiliary roller 46, stable conveyance of the wide backing paper is made possible. Note that it is not essential to provide the auxiliary roller 46. Even when there is no auxiliary roller 46, as long as there is the peeling roller 45, peeling and issuing can be executed. On each arm 421, a protrusion 422 protruding outward is formed. As will be described later, the protrusion 422 is provided to engage the peeling unit 4 with the printer cover 3 during peeling and issuing.

[0057] As shown in FIG. 6, near the pair of shafts 42a of the peeling roller holding portion 42, a pair of coil springs 43 (an example of a biasing member) are provided. Although not shown, one end of the coil spring 43 is connected to the peeling roller holding portion 42, and the other end is connected to the peeling roller cover 41, thereby biasing the peeling roller holding portion 42 in the direction of swinging from the housed position to the protruding position. Therefore, when the peeling roller cover 41 is in the open position (that is, when the peeling unit 4 is in the open position), the peeling roller holding portion 42 is always in the protruding position.

[0058] FIG. 7 is a perspective view of the peeling unit 4 when open, viewed from a different perspective from FIG. 6. When the peeling roller holding portion 42 is in the protruding position, a part of the arm 421 of the peeling roller holding portion 42 abuts on the surface 411 of the peeling roller cover 41. That is, the surface 411 of the peeling roller cover 41 functions as a stopper for the peeling roller holding portion 42 that swings by the coil spring 43.

[0059] Next, the operation when changing the peeling unit 4 from continuous issuing to the open position will be described with reference to FIGS. 8 and 9. Figures 8 and 9 are side views of the lever 52 for releasing the peeling unit and the peeling unit 4, and the states S1 to S3 show these side views in chronological order. State S1 is the state when the printer cover 3 is opened during continuous printing, state S2 is the state when the operation of the button for releasing the peeling unit continues, and state S3 is the state when the operation of the button for releasing the peeling unit is released.

[0060] The lever 52 for releasing the peeling unit and the peeling unit 4 are engaged by inserting the engaging protrusion 523 of the lever 52 for releasing the peeling unit from the inside into the engaging hole 415 of the peeling roller cover 41. The lever 52 for releasing the peeling unit swings so as to move the peeling roller cover 41 between the closed position and the open position. The engaging hole 415 has, for example, a heart shape, and the engaging protrusion 523 can move within the engaging hole 415. As shown in state S1 of FIG. 8, when the printer cover 3 is opened during continuous printing, the engaging protrusion 523 is located below the engaging hole 415. At this time, the peeling roller holding portion 42 is in the housed position below the back surface 412 (see FIG. 6) of the peeling roller cover 41.

[0061] Here, when the button 52b for releasing the peeling unit is pressed (operated), the lever 52 for releasing the peeling unit swings clockwise around the shaft 27a in FIG. 8. As a result, the engaging protrusion 523 of the lever 52 for releasing the peeling unit moves upward within the engaging hole 415 and presses the peeling roller cover 41 upward at the upper edge of the engaging hole 415. As a result, the peeling roller cover 41 swings counterclockwise around the shaft 41a toward the open position in FIG. 8. As described above, the peeling roller holding portion 42 is biased in the swinging direction from the housed position toward the protruding position by the coil spring 43 (see FIG. 6). Therefore, when the peeling roller cover 41 swings toward the open position, the position regulation of the peeling roller holding portion 42 by the second stopper 522 described later is released, and a space in which the peeling roller holding portion 42 can swing is formed. Therefore, the peeling roller holding portion 42 swings to the protruding position as shown in state S2 of FIG. 8.

[0062] As shown in the state S2 of FIG. 8, when the peeling roller cover 41 is in the open position, the shaft 42a is at a higher position than when it is in the closed position. Also, as described above, in the printer 1, when the peeling roller cover 41 is in the open position, a space is formed in which the peeling roller holding portion 42 can swing from the housed position to the protruding position. Therefore, the peeling roller holding portion 42 can be vigorously protruded upward by the biasing force of the coil spring 43.

[0063] When the pressing of the peeling unit release button 52b is released from the state shown in the state S2, the peeling unit release lever 52 swings counterclockwise in FIG. 8 around the shaft 27a by the restoring force of the coil spring 53. As a result, the peeling unit release lever 52 and the peeling roller cover 41 return to the position of the state S1. However, the peeling roller holding portion 42 that has once swung to the protruding position remains in the protruding position without returning to the housed position. As a result, the peeling unit 4 takes the form shown in the state S3 of FIG. 9.

[0064] [Engagement between the peeling unit 4 and the printer cover 3] In the printer 1, when the printer cover 3 is swung from the open position to the closed position in the state S3 of FIG. 9, the peeling unit 4 can be set to the peeling issuing position while the printer cover 3 and the peeling unit 4 are engaged with each other. Therefore, hereinafter, with reference to FIGS. 10 and 11, the engagement between the peeling unit 4 and the printer cover 3 at the time of peeling issuance will be described. First, the structure of the printer cover 3 for engaging with the peeling unit 4 will be described with reference to FIG. 10. FIG. 10A is a plan view of the printer cover 3, and FIG. 10B is an enlarged cross-sectional view taken along line A-A of FIG. 10A.

[0065] As shown in FIG. 10A, the printer cover 3 has a pair of peeling unit receiving portions 31 at the front end. The peeling unit receiving portions 31 are provided in the vicinity of the positions where the platen roller 10 and the peeling bar 12 are supported. As shown in FIG. 10B, a guide groove 31p with an open front is formed in the peeling unit receiving portion 31. The guide groove 31p is a groove that is open only on the inner side along the direction from the front end to the rear end of the printer cover 3. The guide groove 31p receives the protrusion 422 (see FIG. 9) of the peeling unit 4 located in the front during the process of closing the printer cover 3.

[0066] A roller pressing mechanism 37 is provided in the guide groove 31p. As will be described later, when the printer cover 3 is in the closed position, the roller pressing mechanism 37 presses the peeling roller 45 toward the platen roller 10, thereby generating a nip pressure when the peeling roller 45 and the platen roller 10 sandwich the mount. The roller pressing mechanism 37 includes a contact portion 32 disposed in the guide groove 31p and a coil spring 33 (an example of a biasing member) disposed behind the contact portion 32. As the printer cover 3 moves toward the closed position, the protrusion 422 of the peeling unit 4 is guided to the contact portion 32.

[0067] When an operation is performed to move the printer cover 3 from the open position to the closed position in the state S3 of FIG. 9, during the movement of the printer cover 3, the protrusion 422 of the peeling unit 4 enters the guide groove 31p of the peeling unit receiving portion 31. As the printer cover 3 swings to the closed position, the protrusion 422 advances along the guide groove 31p to the rear of the printer cover 3 and contacts the contact portion 32. In this way, the printer cover 3 engages with the peeling unit 4. When the printer cover 3 reaches the closed position, the peeling roller 45 of the peeling unit 4 engaged with the printer cover 3 is in a position facing the platen roller 10. Therefore, the operator can engage the printer cover 3 with the peeling unit 4 and move the peeling unit 4 to the peeling issuing position only by performing an operation of closing the printer cover 3.

[0068] FIG. 11 is an enlarged cross-sectional view showing the vicinity of the platen roller 10 when the printer cover 3 is completely closed and the peeling unit 4 is set at the peeling issuing position. As shown in FIG. 11, when the printer cover 3 is in the closed position, the peeling roller 45 of the peeling unit 4 is disposed at a position facing the platen roller 10. The protrusion 422 of the peeling unit 4 abuts against the contact portion 32 of the peeling unit receiving portion 31 of the printer cover 3, and the coil spring 33 behind the contact portion 32 is in a compressed state. Since the restoring force of the coil spring 33 acts on the peeling roller 45 through the protrusion 422, the nip pressure when sandwiching the backing paper can be generated by pressing the peeling roller 45 against the platen roller 10. Thereby, the force in the rotational direction around the shaft 42a of the peeling roller holding portion 42 (F5c in FIG. 11) is replaced with the nip pressure between the peeling roller 45 and the platen roller 10.

[0069] In one embodiment, as shown in FIG. 11, when viewed in side view, the normal direction of the contact surface of the contact portion 32 with which the protrusion 422 abuts (the direction indicated by F5b) and the direction from the center of the peeling roller 45 toward the center of the platen roller 10 may be the same, but the direction of the force F5 changes depending on the angle at which the protrusion 422 abuts against the contact portion 32, and thus it is not limited to being the same. As shown in FIG. 11, the peeling roller 45 is pressed against the platen roller 10 by the component force F5b of the reaction force F5 of the contact portion 32 acting on the protrusion 422 in the normal direction with respect to the contact surface, and the nip pressure when sandwiching the backing paper can be more effectively generated.

[0070] [Operation of housing the peeling roller holding portion 42] Next, with reference to FIGS. 12 and 13, the operation when the peeling roller holding portion 42 at the protruding position is housed under the peeling roller cover 41 and the peeling unit 4 is set to the continuous feeding position will be described. To switch from peel issuance to continuous issuance, press the cover release button 51b to open the printer cover 3, and then press the peel unit release button 52b. Then, as shown in the state S2 of FIG. 8, the peel roller cover 41 swings to the open position, and the peel roller holder 42 swings to the protruding position. In this state, the operator can set the peel unit 4 to the continuous issuance position by performing an operation (folding operation) of folding the peel roller holder 42 and housing it under the peel roller cover 41.

[0071] States S5 to S9 in FIGS. 12 and 13 are perspective views showing the peel unit release lever 52 and the peel unit 4 in chronological order when the operator performs the folding operation of the peel unit 4. As shown in FIG. 12, the peel unit release lever 52 has a first stopper 521 (an example of a first restricting portion) and a second stopper 522 (an example of a second restricting portion) that protrude inward. The first stopper 521 and the second stopper 522 are arranged at intervals in the front-rear direction and are provided to restrict the swing of the arm 421 by abutting against the arm 421 of the peel roller holder 42.

[0072] The state S5 in FIG. 12 is a state in which the peel roller cover 41 is in the open position and the peel roller holder 42 is in the protruding position, which is the same as the state S2 in FIG. 8. This state is maintained by the operator continuously pressing the peel unit release button 52b.

[0073] In state S5, when the operator rotates (or swings) the peeling roller holding part 42 around the shaft 42a and moves it to the accommodated position below the back surface 412 of the peeling roller cover 41, state S6 is entered. At this time, due to the operating force, the part of the arm 421 farthest from the shaft 42a gets over the first stopper 521. Therefore, when the arm 421 abuts against the first stopper 521, the swinging of the peeling roller holding part 42 is restricted against the restoring force of the coil spring 43 (see FIG. 6). That is, the first stopper 521 restricts the swinging of the peeling roller holding part 42 by abutting against the arm 421 when the peeling roller holding part 42 is in the accommodated position and the peeling roller cover 41 is in the open position. By the first stopper 521 restricting the swinging of the peeling roller holding part 42, it becomes easy to move the peeling roller cover 41 to the closed position while keeping the peeling roller holding part 42 in the accommodated position. If there were no first stopper 521, the operator would need to release the pressing of the peeling unit release button 52b while holding down the peeling roller holding part 42 so that it does not swing from the accommodated position and move the peeling roller cover 41 to the closed position. That is, providing the first stopper 521 improves the operability.

[0074] With the peeling roller holding part 42 locked in the accommodated position by the first stopper 521, when the operator releases the pressing of the peeling unit release button 52b, the peeling roller cover 41 starts to move toward the closed position. State S7 shows the state when the peeling roller cover 41 is on the way toward the closed position. In the process of the peeling roller cover 41 moving toward the closed position, along with the swinging of the peeling roller cover 41, the restriction of the swinging of the arm 421 by the first stopper 521 is released. That is, the outer edge of the arm 421 is formed so that the restriction of the swinging of the arm 421 is released when the peeling roller cover 41 is closed to a predetermined angle.

[0075] The state S8 in FIG. 13 is the state when the operator further closes the peeling roller cover 41 from the state S7. The peeling roller holding part 42 whose swinging is restricted by the first stopper 521 swings by the restoring force of the coil spring 43, but the swinging is restricted again by the second stopper 522 located behind the first stopper 521. That is, the second stopper 522 abuts on the arm 421 while the peeling roller holding part 42 moves from the open position to the closed position, thereby restricting the swinging of the peeling roller holding part 42 at a position between the housed position and the protruding position. The state S9 is the state where the peeling roller cover 41 is in the closed position, and the peeling unit 4 is in the continuous issuing position. By providing the second stopper 522, it is possible to prevent the peeling roller holding part 42 from swinging while the peeling roller cover 41 moves from the open position to the closed position. Further, since the second stopper 522 is located behind the first stopper 521, as shown in the state S9, when the peeling unit opening button 52b is operated in the state where the peeling unit 4 is in the continuous issuing position, the peeling roller holding part 42 can be smoothly swung to the protruding position.

[0076] Note that it is not always necessary to provide the first stopper 521 and the second stopper 522. Providing either one of the stoppers contributes to the improvement of operability. Even when neither the first stopper 521 nor the second stopper 522 is provided, it is possible to perform the folding operation of the peeling unit 4. That is, it is possible to house the peeling roller holding part 42 under the peeling roller cover 41 by having the operator carefully move the peeling roller cover 41 to the closed position while holding the peeling roller holding part 42 by hand at the housed position.

[0077] [Continuous Issuing and Peel Issuing Switching Operation of Printer 1] Next, the continuous issuing and peel issuing switching operation of the printer 1 will be described with reference to FIGS. 14 and 15. The states S10 to S15 in FIGS. 14 and 15 are side views of the main part of the printer 1 when switching from continuous issuing to peel issuing, shown in chronological order. In FIG. 15, the illustration of the platen holding bracket 27 is omitted.

[0078] State S10 in FIG. 14 shows the state of the printer 1 during continuous printing. In this state, the platen shaft 10a of the platen roller 10 pivotally supported by the printer cover 3 fits into the groove 27b of the platen holding bracket 27, thereby holding the printer cover 3. In state S10, the peeling unit 4 is set at the continuous printing position.

[0079] When the operator presses the cover release button 51b in state S10, the holding of the platen shaft 10a by the platen holding bracket 27 is released. Therefore, as shown in state S11, the printer cover 3 moves toward the open position by the biasing force of the torsion spring provided on the hinge 8 (see FIG. 2). Next, when the operator presses the peeling unit release button 52b, as shown in state S12, the peeling roller cover 41 swings from the closed position to the open position, and the peeling roller holding portion 42 swings from the housed position to the protruding position. Then, when the operator releases the pressing of the peeling unit release button 52b, as shown in state S13 of FIG. 15, the peeling roller cover 41 returns to the closed position, but the peeling roller holding portion 42 remains in the protruding position by the biasing force of the coil spring 43 (see FIG. 6).

[0080] Next, when the operator performs an operation to close the printer cover 3, the projection 422 of the peeling roller holding portion 42 in the protruding position is inserted into the guide groove 31p (see FIG. 10) of the printer cover 3 and guided along the guide groove 31p, so that, as shown in state S14, the printer cover 3 and the peeling unit 4 are engaged.

[0081] As shown in state S15, when the printer cover 3 reaches the closed position, the platen shaft 10a of the platen roller 10 is held by the platen holding bracket 27, and the peeling unit 4 is set at the peeling issuing position. That is, the peeling roller 45 of the peeling unit 4 is disposed at a position facing the platen roller 10, and sandwiches the backing paper PM together with the platen roller 10. In this state, as described above, the protrusion 422 engaged with the printer cover 3 is pressed by the coil spring 33 (see FIG. 11), so that an appropriate nip pressure of the peeling roller 45 against the platen roller 10 is generated. In peeling issuance, the label PL printed by the thermal head 28 is peeled from the backing paper PM by the backing paper PM being rapidly swung by the peeling bar 12. The peeling roller 45 rotates passively in accordance with the rotation of the platen roller 10 and discharges the backing paper PM.

[0082] When switching from peeling issuance to continuous issuance, the cover opening button 51b is pressed to open the printer cover 3, and then the peeling unit opening button 52b is pressed. Thereby, the peeling roller cover 41 of the peeling unit 4 swings to the open position, and the peeling roller holding portion 42 swings to the protruding position. Thereafter, as described with reference to FIGS. 12 and 13, by performing the folding operation of the peeling unit 4, the peeling unit 4 is set at the continuous issuance position.

[0083] As described above, the printer 1 according to one embodiment includes the peeling unit 4 movable between the continuous issuance position and the peeling issuance position. When the peeling unit 4 is at the continuous issuance position, the peeling roller holding portion 42 that holds the peeling roller 45 can be compactly accommodated in the accommodated position below the back surface of the peeling roller cover 41. When switching from continuous printing to sheet-fed printing, open the printer cover 3 and operate the sheet separation unit release button 52b to move the sheet separation roller holder 42 to the protruding position, and then close the printer cover 3. That is, the switching can be achieved by a simple three-step action, which is excellent in operability. Moreover, when the printer cover 3 is in the closed position, the sheet separation roller 45 is pressed against the platen roller 10 by the roller pressing mechanism 37 of the printer cover 3, and an appropriate nip pressure can be generated. Conversely, when switching from sheet-fed printing to continuous printing, open the printer cover 3 and operate the sheet separation unit release button 52b to move the sheet separation roller holder 42 to the protruding position, perform a folding operation to move the sheet separation roller holder 42 to the housed position, and then close the printer cover 3. In this case as well, it only requires a simple operation.

[0084] [Method for attaching and detaching the thermal head 28] Next, the method for attaching and detaching the thermal head 28 of the printer 1 from the printer 1 will be described with reference to FIGS. 16 to 19. FIG. 16A is a view showing the front side (an example of the first side) of the thermal head 28 biased by the coil spring 55 on both sides of the thermal head 28, and FIG. 16B is a view showing the rear side (an example of the second side) of the thermal head 28. The rear side of the thermal head 28 faces the platen roller 10. FIG. 17 is a cross-sectional view showing an enlarged view of cross-sections A-A and B-B of FIG. 16A.

[0085] As shown in FIGS. 16 and 17, the thermal head 28 has a structure in which a substrate 282 is attached to a heat dissipation plate 281 (an example of a base portion) having a substantially rectangular shape in plan view. The heat dissipation plate 281 is made of a metal material with high thermal conductivity such as aluminum. As can be seen from the cross-section A-A of FIG. 17, the substrate 282 (an example of a coating layer) is attached to the heat dissipation plate 281 so as to extend from the front surface 281a of the heat dissipation plate 281 to the back surface 281b on the opposite side of the front surface 281a through the first end portion 281e1 intervening between the front surface 281a and the back surface 281b. The substrate 282 is, for example, a ceramic substrate. The area occupied by the substrate 282 in the heat sink 281 is an example of a covered area. The surface 281a (the surface facing the rear of the printer 1) is an example of the first surface, and the back surface 281b (the surface facing the front of the printer 1) is an example of the second surface. As shown in the cross-section taken along line B-B of FIGS. 16B and 17, a notch 283c (an example of an opening and an uncovered area) is provided at a substantially central position in the longitudinal direction (lateral direction) of the surface 281a of the thermal head 28. The substrate 282 is not formed in the notch 283c, and the surface 281a of the heat sink 281 is exposed. As will be described later, a convex portion 211 (see FIG. 19) for enabling the thermal head 28 to swing is abutted against the notch 283c.

[0086] As shown in the cross-section taken along line A-A of FIGS. 16A and 17, surface-mounted components (SMDs) such as, but not limited to, a connector 285, an EEPROM 286 (an example of a memory chip), and a diode 287 are mounted on the substrate 282 attached to the back surface 281b of the heat sink 281. In a state where the thermal head 28 is mounted on the printer 1, a flexible cable 57 is connected to the connector 285. The flexible cable 57 transmits signals from a circuit board (not shown) of the printer 1 to the thermal head 28. In a state where the thermal head 28 is attached to the printer 1, since the relatively tall surface-mounted components (such as the connector 285, the EEPROM 286, and the diode 287 in FIG. 16A) mounted on the back surface 281b of the heat sink 281 face the front of the printer 1, the surface-mounted components can be protected from moisture and the like that may enter from the discharge portion 20 located behind the thermal head 28. On the rear side of the thermal head 28 facing the discharge portion 20 (the side with the surface 281a of the heat sink 281), a drive IC (not shown) is mounted in the vicinity of the heat generating portion 284. Since the drive IC is low in height, the drive IC and the wiring are protected by a protective layer or a coating together with the heat generating portion 284, so there is no problem even if moisture entering from the discharge portion 20 adheres.

[0087] As shown in FIG. 16B, since no tall surface-mounted components such as connectors are arranged on the rear side of the thermal head 28 (the side where the heat-generating portion 284 is arranged), the conveyance angle of the label PL with respect to the heat-generating portion 284 can be reduced (that is, the angle is made close to vertical with respect to the heat-generating portion 284 when viewed in side view) (see FIG. 3). Therefore, the printing quality can be improved for the following reasons. The heat-generating portion 284 generally includes a glaze layer (partial glaze) having a convex shape, and thus has a convex shape as a whole. If tall surface-mounted components are arranged on the rear side of the thermal head 28, the conveyance angle of the label PL with respect to the heat-generating portion 284 increases in order to avoid the surface-mounted components. In that case, due to the convex shape of the heat-generating portion 284 and the rigidity (stiffness) of the label PL, the label PL tends to float away from the heat-generating portion 284 at the position of the heat-generating portion 284, so it is difficult to apply an optimal printing pressure to the label PL between the heat-generating portion 284 and the platen roller 10. On the other hand, when the conveyance angle of the label PL with respect to the heat-generating portion 284 is small, even if the heat-generating portion 284 has a convex shape, in the vicinity of the top of the heat-generating portion 284, the heat-generating portion 284 can sandwich the label PL with an appropriate printing pressure between the heat-generating portion 284 and the platen roller 10, so the printing quality can be improved.

[0088] A pair of shafts 28a extending outward are connected to both end faces of the heat sink 281. As will be described later, the pair of shafts 28a are provided for attaching the thermal head 28 to the internal frame of the printer 1. As shown in FIGS. 16A and 16B, since the shaft 28a includes a large-diameter portion connected to the heat sink 281 and a small-diameter portion extending outward from the large-diameter portion, it has a high-strength configuration. The small-diameter portion of the shaft 28a is inserted into a bearing receiving groove 25 described later.

[0089] FIG. 18 is a cross-sectional view of a part of the printer 1 in a plane orthogonal to the left-right direction in a state where the peeling roller cover 41 is in the open position and the peeling roller holding portion 42 is in the protruding position by continuously pressing the button 52b for releasing the peeling unit. In FIG. 17, the thermal head 28 and the coil spring 55 are not shown so that the bearing receiving groove 25 into which the shaft 28a of the thermal head 28 is inserted can be clearly seen. As shown in FIG. 18, a substantially L-shaped bearing receiving groove 25 is formed in the inner frame of the printer 1. Although only the bearing receiving groove 25 for receiving one of the pair of shafts 28a of the thermal head 28 is shown in FIG. 18, the bearing receiving groove 25 for receiving the other shaft 28a is formed in the same manner.

[0090] As shown enlarged in FIG. 18, the bearing receiving groove 25 has a first groove 251 and a second groove 252. Here, the positions P1 and P2 virtually indicate the positions that the shaft 28a can take within the bearing receiving groove 25. In the present disclosure, when the shaft 28a is at the positions P1 and P2, it may be described that the thermal head 28 is at the positions P1 and P2, respectively.

[0091] The first groove 251 extends in a direction for attaching and detaching the thermal head 28 from the position P1 (an example of the first position of the printing head). The second groove 252 extends from the position P1 to the position P2 (an example of the second position of the printing head) in the direction in which the coil spring 55 in front of the thermal head 28 biases the thermal head 28 (that is, the rearward direction; an example of the first direction). By forming the bearing receiving groove 25 as an L-shaped groove composed of the first groove 251 and the second groove 252, it is possible to switch between a position (position P2) where the thermal head 28 cannot be removed by moving upward and a position (position P1) where the thermal head 28 can be removed by moving upward with a relatively simple shape.

[0092] Further, the thermal head 28 is displaceable between a position P1 and a position P2 in the direction in which the coil spring 55 biases the thermal head 28. Therefore, when attaching the thermal head 28, if the shaft 28a is inserted along the first groove 251 to the position P1, it can be easily set to the position P2 by the biasing force of the coil spring 55.

[0093] Next, with reference to FIG. 19, a method for replacing the thermal head 28 will be described. FIG. 19 is a diagram for explaining a method for replacing the thermal head 28, and shows partial side views of states S20 and S21 of the thermal head 28 to be replaced. First, when the thermal head 28 to be replaced is attached to the printer 1, as shown in the state S20, it is disposed at the position P2 of the bearing receiving groove 25. In this state, due to the biasing force of the coil spring 55, the entire thermal head 28 is biased toward the platen roller 10 (not shown in FIG. 19) (that is, rearward), whereby the shaft 28a of the thermal head 28 is stably positioned at the position P2.

[0094] Here, to remove the thermal head 28 to be replaced, as shown in the state S21, the thermal head 28 to be replaced is moved from the position P2 in the direction opposite to the first direction (that is, the direction in which the coil spring 55 biases the thermal head 28) (forward) against the biasing force of the coil spring 55 to the position P1. Next, by moving the thermal head 28 to be replaced upward (an example of the second direction) from the position P1, the shaft 28a of the thermal head 28 to be replaced is detached from the bearing receiving groove 25, and the thermal head 28 to be replaced is removed. At this point, since the flexible cable 57 is connected to the connector 285 of the thermal head 28 to be replaced (see FIG. 21B), the flexible cable 57 is separated from the connector 285 of the thermal head 28 to be replaced. After separating the thermal head 28 to be replaced from the flexible cable 57, to attach a new thermal head 28 to the printer 1, the reverse procedure of the removal case is performed. That is, first, a separated flexible cable 57 is connected to a connector 285 of a new thermal head 28 (see FIG. 16A). Then, when an operation of inserting the new thermal head 28 into position P1 is performed, the thermal head 28 moves from position P1 to position P2 by the biasing force of the coil spring 55. That is, the new thermal head 28 is moved downward (an example of the direction opposite to the second direction), and a shaft 28a of the new thermal head 28 is inserted from a first groove 251 (see FIG. 18) into a bearing receiving groove 25. At this time, while pushing the tip of the coil spring 55 (one end at the rear of the coil spring 55) forward (the direction against the biasing force of the coil spring 55) with the back surface 281b of the new thermal head 28 (the surface facing the front of the printer 1), the insertion is performed. When the shaft 28a of the new thermal head 28 reaches position P1, the shaft 28a can be moved to position P2 without requiring an operating force by the biasing force of the coil spring 55. As described above, the thermal head 28 is replaced.

[0095] As shown in FIG. 16B, since surface mount components such as connectors are not arranged on the rear side of the thermal head 28 (the side where the heat generating portion 284 is arranged), there is an advantage that the replacement work of the thermal head 28 is easy. Together with the fact that the thermal head 28 is biased rearward by the coil spring 55, if the rear side of the thermal head 28 is not flat, the thermal head 28 may interfere with the rear internal frame (for example, the wall surface 21, etc.; see FIG. 20), making it difficult to smoothly insert the thermal head 28 into the bearing receiving groove 25. On the other hand, since the rear side of the thermal head 28 is flat, the new thermal head 28 can be smoothly inserted into the bearing receiving groove 25 in a situation where the biasing force by the coil spring 55 acts.

[0096] The thermal head 28 is attached and detached when the peeling unit 4 is in the open position. That is, when the peeling unit 4 is in the closed position, it is in a position covering at least a part of the thermal head 28, whereas when the peeling unit 4 is in the open position, it is in a position not covering the thermal head 28 as shown in FIG. 2. And the attachment and detachment of the thermal head 28 are performed when the peeling unit 4 is in the open position. When the peeling unit 4 is in the closed position, there is no other member between the peeling unit 4 and the thermal head 28, and the peeling unit 4 directly covers at least a part of the thermal head 28.

[0097] Referring to FIG. 18 again, in a state where the peeling roller cover 41 is in the open position (that is, the peeling unit 4 is in the open position), a space where the thermal head 28 with the shaft 28a located at the position P1 can be attached and detached is formed. Therefore, when the operator removes the thermal head 28 from the printer 1, the printer cover 3 is opened, and while continuously pressing the peeling unit opening button 52b to bring the peeling unit 4 into the state shown in FIG. 18, as described above, against the biasing force of the coil spring 55, the shaft 28a of the thermal head 28 is slid from the position P2 to the position P1, and then the thermal head 28 can be simply pulled upward. Moreover, in the printer 1 of the embodiment, as shown in FIG. 2, since at least a part of the rear side of the thermal head 28 is exposed to the roll paper storage chamber 9, by once removing the roll paper R, a working space can be secured when removing the thermal head 28, and the thermal head 28 can be removed more easily. That is, when performing the operation of sliding the shaft 28a of the thermal head 28 from the position P2 to the position P1, the operator needs to apply an operating force to the thermal head 28 from the rear to the front. However, since there is space behind the thermal head 28, it is easy to apply the operating force. Also, when the operator performs the operation of pulling out the thermal head 28 upward, since there is space behind the thermal head 28, it is easy to put a hand into the space and the pulling-out operation becomes easier.

[0098] When attaching the thermal head 28 to the printer 1, the operation is the reverse of when removing the thermal head 28 from the printer 1. Similarly, with the peeling unit 4 in the state shown in FIG. 18, while pressing the tip of the coil spring 55 (the rear end of the coil spring 55) forward (in the direction against the biasing force of the coil spring 55) on the back surface 281b (the surface facing the front of the printer 1) of the thermal head 28, the shaft 28a of the thermal head 28 is inserted from the first groove 251 of the bearing receiving groove 25 to the position P1. Due to the biasing force of the coil spring 55, the thermal head 28 moves to the position P2. Therefore, the thermal head 28 can be easily replaced without tools.

[0099] In another embodiment, the bearing receiving groove may not be L-shaped and may have another form. For example, as long as the thermal head 28 can be attached and detached from the position P1, the bearing receiving groove may have a groove extending obliquely forward or obliquely backward from the position P1. Also, although it becomes slightly more difficult to attach and detach, the bearing receiving groove may be configured such that the groove path between the position P1 and the position P2 is U-shaped, starting from the position P1 in FIG. 18, proceeding forward, slightly downward, and then backward to provide the position P2. In this case, the operator can remove the shaft 28a by moving the shaft 28a of the thermal head 28 from the position P2 to the position P1 along the U-shaped groove.

[0100] [Support Structure of Thermal Head 28] Next, with reference to FIGS. 20 and 21, the support structure of the thermal head 28 will be described. First, with reference to FIG. 20, the structure of the internal frame behind the thermal head 28 will be described. FIG. 20 is a perspective view showing a part of the internal frame together with the components attached to the internal frame, with a part enlarged. Note that the thermal head 28 is not shown in FIG. 20.

[0101] As shown in FIG. 20, the inner frame has a wall surface 21 facing the rear surface of the thermal head 28 (on the side of the roll paper storage chamber 9) in the region where the thermal head 28 is disposed. A convex portion 211 is formed on the wall surface 21. The convex portion 211 (an example of the contact portion) contacts the rear surface of the thermal head 28 when the thermal head 28 is mounted. As shown in FIG. 20, preferably, the contact surface of the convex portion 211 is curved so as to be convex toward the rear surface of the thermal head 28.

[0102] Both FIGS. 21A and 21B are diagrams for explaining the force acting on the thermal head 28 in the printer 1 of the embodiment. FIG. 21A shows a cross section in a plane orthogonal to the vertical direction, and FIG. 21B shows a cross section in a plane orthogonal to the left-right direction. Note that FIGS. 21A and 21B have different scales. As shown in FIG. 21A, the convex portion 211 is provided at a position that contacts substantially the center in the left-right direction of the thermal head 28 when the thermal head 28 is mounted. Further, the convex portion 211 is provided at a position that contacts substantially the center position of a pair of coil springs 55 in the left-right direction on the rear side of the thermal head 28.

[0103] As described above, a notch portion 283c (see FIG. 16B) is provided substantially at the center in the left-right direction of the thermal head 28, and the convex portion 211 contacts the thermal head 28 at the notch portion 283c. Since the notch portion 283c is not covered by the substrate 282 and is a portion where the heat dissipation plate 281 of the thermal head 28 is exposed, the thermal head 28 can be supported more stably. Note that providing the notch portion 283c is not essential. The convex portion 211 may support the thermal head 28 in the region of the substrate 282 without providing the notch portion 283c.

[0104] Preferably, a concave portion having a shape corresponding to the convex portion 211 is provided at a position on the rear surface of the thermal head 28 that contacts the convex portion 211. Thereby, the position where the thermal head contacts the convex portion 211 is less likely to shift, and the thermal head 28 can be supported more stably. In addition, in one embodiment, a recess may be provided on the wall surface 21 of the internal frame, and a convex portion having a shape corresponding to the recess on the wall surface 21 may be provided on the rear surface of the thermal head 28. Even in this case, the thermal head 28 can be stably supported while being swingable. The shape of the convex portion 211 shown in FIG. 20 is merely an example, and another form can be adopted as long as the thermal head 28 can be swingably supported. For example, instead of the shape shown in FIG. 20, the outer shape of the convex portion 211 may be a part of a spherical surface.

[0105] As shown in FIG. 21A, when the printer 1 is viewed in plan view, restoring forces F1 and F2 by a pair of coil springs 55 acting rearward act on the front side of the thermal head 28, and a reaction force F3 from the convex portion 211 abutting on the rear side of the thermal head 28 acts. Here, since the convex portion 211 is located substantially at the center when the printer 1 is viewed from above, the thermal head 28 is configured to be swingable clockwise and counterclockwise in FIG. 21A with the convex portion 211 as a fulcrum.

[0106] As shown in FIG. 21B, when the printer 1 is viewed in side view, restoring forces F1 and F2 (F2 is not visible in FIG. 21B) by a pair of coil springs 55 acting rearward act on the front side of the thermal head 28. A reaction force F4 from the platen roller 10 acts on the rear side of the thermal head 28 above the acting points of the restoring forces F1 and F2, and a reaction force F3 from the convex portion 211 acts on the rear side of the thermal head 28 below the acting points of the restoring forces F1 and F2. Therefore, the thermal head 28 is configured to be swingable clockwise and counterclockwise in FIG. 21B with the convex portion 211 as a fulcrum.

[0107] Moreover, when viewed in side view of the printer 1, the acting point of the biasing force of the coil spring 55 on the thermal head 28 is between the position where the thermal head 28 receives a reaction force from the platen roller 10 and the position where the convex portion 211 supports the rear side of the thermal head 28. Therefore, since the biasing force of the coil spring 55 is received vertically, the thermal head 28 can be supported in a well-balanced manner.

[0108] In FIG. 21B, on the rear side of the thermal head 28, the surface where the convex portion 211 abuts (that is, the surface where the heat dissipation plate 281 is exposed by the notch portion 283c) and the surface corresponding to the heat generating portion 284 are preferably on the same reference plane. Thereby, the heating element of the thermal head 28 can be pressed against the platen roller 10 at an appropriate angle.

[0109] As shown in FIGS. 21A and 21B, the thermal head 28 is configured to be swingable in the clockwise or counterclockwise swing direction when the printer 1 is viewed from the side, with the convex portion 211 as a fulcrum, and in the clockwise or counterclockwise swing direction when the printer 1 is viewed from the plan view, with the convex portion 211 as a fulcrum. Therefore, the thermal head 28 can apply pressure uniformly to the platen roller 10 during printing. The reason is as follows.

[0110] In a conventional printer equipped with a thermal head, the thermal head was attached to the internal frame or housing of the printer by fixing it at, for example, two points using screws, shafts, brackets, or the like. In such a case, due to a shift in the attachment position, the pressure when the thermal head abuts against the platen roller may not be uniform in the axial direction of the platen roller, and there is a risk of deterioration in printing quality. On the other hand, in the present embodiment, since the thermal head 28 is swingable with the convex portion 211 as a fulcrum in the side view and plan view of the printer 1, for example, when there is an attachment error of the platen roller 10, when there is a circumferential runout during the rotation of the platen roller 10, or when there are irregularities in the label temporarily attached to the backing paper, etc., the thermal head 28 can follow and maintain a uniform pressure against the platen roller 10. Moreover, since the thermal head 28 is displaceable between the positions P1 and P2 (see FIG. 18) in the direction in which the coil spring 55 biases the thermal head 28, the swinging of the thermal head 28 with the convex portion 211 as a fulcrum is not hindered.

[0111] In a conventional printer equipped with a thermal head, there was a type that provided a fulcrum shaft below the thermal head and fixed the shaft to the printer body to make the thermal head swingable in a side view. However, unlike the printer 1, the thermal head could not be replaced without tools. On the other hand, the printer 1 is superior to the prior art in that the thermal head 28 can be replaced without tools and is swingable in both the side view and the plan view of the printer 1.

[0112] In another embodiment, convex portions 211 may be provided at two positions spaced apart in the left-right direction on the wall surface 21 shown in FIG. 20. Even in this case, in the side view of the printer 1, the thermal head 28 can be swung with the convex portion 211 as a fulcrum. Even when the thermal head 28 is swingable only in the side view of the printer 1, it can contribute to a reduction in print quality. In another embodiment, convex portions 211 may be provided at two positions spaced apart in the up-down direction on the wall surface 21 shown in FIG. 20. Even in this case, in the plan view of the printer 1, the thermal head 28 can be swung with the convex portion 211 as a fulcrum. Even when the thermal head 28 is swingable only in the plan view of the printer 1, it can contribute to a reduction in print quality.

[0113] As shown in FIG. 16A, a flexible cable 57 is detachably connected to the thermal head 28. As shown in FIG. 21B, this flexible cable 57 is connected from the connector 285 of the thermal head 28 to a circuit board (not shown) in front of the printer 1 when the thermal head 28 is mounted on the printer 1. At this time, the flexible cable 57 is fixed at the fixing position 24a on the upper surface of the bracket 24 in front of the thermal head 28, for example, by screwing or an adhesive.

[0114] A cable accommodation chamber 59 for accommodating a flexible cable 57 is formed between the thermal head 28 and the circuit board. Between the connector of the thermal head 28 and the fixed position 24a, a relatively long flexible cable 57 is configured to be accommodated in the cable accommodation chamber 59. Therefore, when the thermal head 28 is removed, the thermal head 28 can be moved to a position sufficiently higher than the printer 1 with reference to the fixed position 24a, and the operation of removing the flexible cable 57 from the connector of the thermal head 28 and replacing it with a new thermal head 28 becomes easy. Note that it is not essential to form the cable accommodation chamber 59. Although the cable length from the connector 285 of the thermal head 28 to the fixed position 24a becomes shorter, even in that case, it is possible to remove the flexible cable 57 from the connector 285 and replace the thermal head 28.

[0115] As shown in FIGS. 21A and 21B, the cable accommodation chamber 59 is formed in a space sandwiched between the platen holding bracket 27 and the thermal head 28. Therefore, the space formed by the U-shaped platen holding bracket 27 in plan view can be efficiently utilized. Note that the cable accommodation chamber 59 does not necessarily have to be formed in a space sandwiched between the platen holding bracket 27 and the thermal head 28. For example, the flexible cable 57 extending from the connector of the thermal head 28 can be passed under the platen holding bracket 27, and an accommodation chamber can also be provided in front of the platen holding bracket 27.

[0116] As described above, in the printer 1 described above, since surface mount components are not mounted on the rear surface of the thermal head 28, the surface mount components can be protected from moisture and the like that may enter from the discharge unit 20. In the above-described printer 1, when the peeling unit 4 is in the open position where it does not cover the thermal head 28, a space where the thermal head 28 can be attached and detached is formed, so that the workability of replacing the thermal head 28 can be improved. Moreover, the thermal head 28 is biased rearward (in the direction toward the platen roller 10), and along this direction, it is configured to be displaceable between a first position where the thermal head 28 can be attached and detached and a second position where the attachment and detachment of the thermal head 28 are restricted. Therefore, to remove the thermal head 28, it is only necessary to move the thermal head 28 from the second position to the first position, and no tools are required.

[0117] In the above-described printer 1, the thermal head 28 is configured to be swingable in the clockwise or counterclockwise swing direction when the printer 1 is viewed from the side, with the convex portion 211 as a fulcrum, and in the clockwise or counterclockwise swing direction when the printer 1 is viewed from the plan view, with the convex portion 211 as a fulcrum. Therefore, the thermal head 28 can apply pressure uniformly to the platen roller 10 during printing, and it is possible to prevent a decrease in printing quality caused by the method of attaching the thermal head.

[0118] [Another Embodiment of the Thermal Head] Next, with reference to FIGS. 22 to 25, the thermal head 28A according to another embodiment will be described. FIG. 22A is a perspective view of the thermal head 28A seen from the front, and FIG. 22B is a perspective view of the thermal head 28A seen from the rear. FIG. 23 is a perspective view of the plate-like member included in the thermal head 28A. FIG. 24 is a perspective view of the thermal head 28A seen from a perspective different from FIG. 22.

[0119] As can be seen by comparing FIGS. 22A and 22B with FIGS. 16A and 16B, the thermal head 28A is different from the thermal head 28 in that it includes a plate-like member 7. The plate-like member 7 is a member formed of a metal material such as stainless steel, and is fastened to the heat sink 281 with screws. As shown in Fig. 23, the plate-like member 7 has a base portion 71, protruding pieces 72L and 72R, and a protruding plate 73.

[0120] The protruding pieces 72L and 72R respectively protrude from both ends of the base portion 71 in a direction orthogonal to the main surface of the base portion 71 (that is, the direction orthogonal to the surface 281a when attached to the heat sink 281). In the state where the plate-like member 7 is attached to the heat sink 281, as shown in Fig. 24, the protruding pieces 72L and 72R protrude on the side where the heat generating portion 284 is mounted. The tips of the protruding pieces 72L and 72R have tip portions 721L and 721R. A hole 72a is formed in the protruding piece 72L, and a U-shaped groove 72b is formed in the protruding piece 72R. As shown in Figs. 22A and 28B, one of the pair of shafts 28a is inserted into the hole 72a, and the other shaft 28a is inserted into the U-shaped groove 72b. Since a hole is formed in one of the tip portions 721L and 721R and a U-shaped groove is formed in the other, the attachment of the plate-like member 7 to the heat sink 281 becomes easy. In the state where the plate-like member 7 is attached to the heat sink 281, as shown in Fig. 22A, the protruding plate 73 protrudes on the side where relatively tall surface-mounted components (such as the connector 285, EEPROM 286, diode 287, etc.) are mounted.

[0121] The protruding plate 73 is provided between the protruding pieces 72L and 72R over the longitudinal direction of the base portion 71, and protrudes from the base portion 71 in a direction opposite to the protruding pieces 72L and 72R. Two holes 71a for inserting screws are formed in the base portion 71 when attaching the plate-like member 7 to the heat sink 281. The base portion 71 has two protrusions 711. As shown in Fig. 22A, the protrusions 711 are arranged so as not to interfere with the surface-mounted components when the plate-like member 7 is attached to the heat sink 281.

[0122] Next, the effects of the thermal head 28A provided with the plate-like member 7 will be described with reference to FIG. 25. FIG. 25 is a side view showing the positional relationship between the thermal head 28A and the platen holding bracket 27.

[0123] As described above, when the printer cover 3 is in the closed position, the platen shaft 10a of the platen roller 10 attached to the printer cover 3 fits into the groove 27b of the platen holding bracket 27, thereby holding the printer cover 3. At this time, in the case of the thermal head 28 not provided with the plate-like member 7, when the operator presses the printer cover 3 from above, such as when performing an operation to close the printer cover 3, the platen roller 10 will shift downward from the designed position where the platen roller 10 and the thermal head 28 are in contact. Due to this, fluctuations in the printing density occur. Further, the thermal head 28 is attached to a bearing receiving groove 25 (see FIG. 18) provided in the inner frame. One end of the shaft 27a of the platen holding bracket 27 is inserted into the boss 52a of the peeling unit opening lever 52, and the other end of the shaft 27a is inserted into a boss provided in the inner frame (see FIG. 5). Therefore, the position where the platen roller 10 and the thermal head 28 are in contact is easily affected by the cumulative assembly error of each part and is prone to deviation from the above-mentioned designed position.

[0124] The above-mentioned disadvantages of the thermal head 28 are eliminated by the thermal head 28A. As shown in an enlarged view in FIG. 25, when the thermal head 28A is mounted on the printer 1 instead of the thermal head 28, the upper ends of the tip portions 721L and 721R of the plate-like member 7 of the thermal head 28A are arranged at positions higher than the edge forming the groove 27b of the platen holding bracket 27. Therefore, the platen shaft 10a that fits into the platen holding bracket 27 abuts against the tip portions 721L and 721R within the groove 27b. Thereby, even when the operator presses the printer cover 3 from above, the platen roller 10 is less likely to shift downward from the designed position where the platen roller 10 and the thermal head 28 are in contact. This is because the plate-like member 7 has a structure integrated with the heat dissipation plate 281 on which the heat generating portion 284 is mounted. Even if the platen shaft 10a presses down the tip portions 721L and 721R, the relative positional relationship between the platen roller 10 and the heat generating portion 284 is hardly affected.

[0125] Referring to FIG. 25 again, when the thermal head 28A is mounted on the printer 1, the protruding plate 73 of the plate-like member 7 protrudes toward the front of the printer 1. Therefore, since the upper part of the cable accommodation chamber 59 formed in front of the thermal head 28A is covered by the protruding plate 73, it is possible to prevent dust from entering the printer 1 from the outside, and it is possible to prevent dust from adhering to the upper surface of the surface mount components arranged on the front side of the thermal head 28A. That is, the protruding plate 73 functions as a shade. In particular, as shown in FIG. 2, since the replacement of the roll paper R is performed with the printer cover 3 in the open position, dust is likely to enter the printer 1, but even in that case, the surface mount components of the thermal head 28A can be protected from dust. Also, from another perspective, there is an advantage that the strength of the plate-like member 7 can be increased by providing the protruding plate 73.

[0126] The embodiments of the printer of the present invention have been described above, but the present invention is not limited to the above embodiments. Also, the above embodiments can be variously improved and modified without departing from the gist of the present invention. For example, the individual technical features described in the above embodiments can be appropriately combined as long as there is no technical contradiction.

[0127] For example, since the structure and the attaching / detaching method of the thermal heads 28 and 28A are not technically related to the structure of the peeling unit 4 and the method of switching the issuing method, they may be applied to a printer not provided with the peeling unit 4. Conversely, the structure of the peeling unit 4 and the method of switching the issuing method may be applied to a printer that employs a structure different from the structure and the attaching / detaching method of the thermal heads 28 and 28A described above.

[0128] Although the case where a part of the internal components of the printer 1 (for example, one end of a shaft, a spring, etc.) is connected to the internal frame has been described, it is not limited thereto, and it may be connected to the main body case 2.

[0129] In the above-described embodiment, the case where continuous paper in which a plurality of labels as printing media are temporarily attached to a backing sheet is used has been described, but it is not limited thereto. When used for continuous issuing, or in the case of a printer not provided with a peeling unit, for example, a continuous label having an adhesive surface on one side (label without backing sheet), a continuous sheet having no adhesive surface (continuous sheet), or not only paper but also a film printable by a thermal head can be used as a printing medium. Further, when conveying a label without a backing sheet where the adhesive is exposed, etc., the conveying path can be coated with a non-adhesive agent and a non-adhesive roller containing silicone or the like can be provided as a platen roller.

Description of Reference Numerals

[0130] 1... Printer 2... Main body case 21... Wall surface 211... Protrusion 24... Bracket 3... Printer cover 31... Peeling unit receiving portion 31p... Guide groove 37... Roller pressing mechanism 32... Contact portion 33... Coil spring 35... Sensor 4... Peeling unit 41... Peeling roller cover 41a…Axis 411…Surface 412…Inner surface 413…U-shaped groove 415…Engagement hole 42…Peeling roller holding part 42a…Axis 421…Arm 422…Projection 43…Coil spring 45…Peeling roller 45a…Axis 46…Auxiliary roller 47…Peeling sensor 6a…Roll paper guide 7…Plate-like member 71…Base part 71a…Hole 711…Projection 72L,72R…Protruding piece 72a…Hole 72b…U-shaped groove 721L,721R…Tip part 73…Protruding plate 8…Hinge 81…Hinge axis 9…Roll paper storage chamber 10…Platen roller 10a…Platen axis 10b…Gear 12…Peeling bar 15…Display panel 20…Discharge part 22b…Gear 25…Bearing receiving groove 251…First groove 252…Second groove 26…Protrusion 27…Platen holding bracket 27a…Axis 27b…Groove 27c…Hole 28,28A…Thermal head 28a…Axis 281…Heat sink 281a…Surface 281b…Inner surface 282…Substrate 283c…Notch 284…Heating part 285…Connector 29…Coil spring 51…Cover release lever 51a…Axis insertion hole 51b…Cover release button 51c…Protrusion 52…Peeling unit release lever 52a…Boss 52b…Peeling unit release button 521…First stopper 522…Second stopper 523…Engaging protrusion 53,55…Coil spring 56…Shaft portion 57…Flexible cable 59…Cable storage chamber P…Continuous paper PM…Mounting board PL…Label R…Roll paper

Claims

1. A printer capable of switching between peel issuance, in which a label detachably attached to a backing sheet of a printing medium is peeled from the backing sheet and issued, and continuous issuance, in which the label is issued without peeling it from the backing sheet, comprising: a conveyance roller for conveying the printing medium; a printing head that sandwiches the conveyance roller and the printing medium and prints information on the label; a peeling unit that holds a peeling roller facing the conveyance roller during peel issuance and is movable between a closed position that covers at least a part of the printing head and an open position that does not cover the printing head; wherein when the peeling unit is in the open position, the peeling unit and the printing head do not overlap when the printer is placed on a horizontal plane and viewed in plan view; a printer.

2. The printer according to claim 1, wherein the printing head is configured not to interfere with the peeling unit when the printing head is slid upward. The printer according to claim 1.

3. The printer according to claim 1, wherein a space for accommodating the printing medium is formed adjacent to the printing head. The printer according to claim 1.

4. The peeling unit includes a peeling roller holder that holds the peeling roller and a peeling roller cover that pivotally supports the peeling roller holder so as to be swingable, when the peeling unit is in the open position, the peeling roller holder is configured to be swingable between a first position where the peeling roller is covered by the peeling roller cover and a second position where the peeling roller is not covered by the peeling roller cover, the peeling unit having a biasing member that biases the peeling roller holder from the first position toward the second position; The printer according to claim 1.

5. The peeling roller cover has a first axis that serves as a swing axis that swings when the peeling unit moves, the peeling roller holder has a second axis pivotally supported by the peeling roller cover, when the peeling roller cover is in the open position, the second axis is at a higher position than when in the closed position, and a space is formed in which the peeling roller holder can swing from the first position to the second position; The printer according to claim 4.

6. The printer includes a printer cover that is swingable between an open position for opening the interior of the printer and a closed position for closing the interior of the printer. The printer cover engages with the peeling unit in response to movement of the printer cover from the open position to the closed position, thereby moving the peeling roller to a position facing the transport roller. The printer according to any one of claims 1 to 5.

7. A printer cover that is swingable between an open position for opening the interior of the printer and a closed position for closing the interior of the printer, A lock member that is swingable between a lock position for locking the printer cover in the closed position and an unlock position for releasing the lock in the closed position of the printer cover, A swing member that swings to move the peeling roller cover between a closed position and an open position, comprising: The lock member and the swing member share a single swing axis. The printer according to claim 4 or 5.

8. The peeling roller cover is swingable about a first axis, comprising a printer body that houses the first axis and has a long hole formed therein. The printer according to claim 4.

9. Comprising a printer body having a protrusion protruding upward, The peeling roller cover has a contact portion that contacts the protrusion when in the closed position, When the peeling roller cover is in the closed position, a gap is provided between the peeling unit and the print head. The printer according to claim 4 or 5.

Images