Thermal head

Abstract

To provide a thermal head which is excellent in waterproof performance compared to a conventional one.SOLUTION: A thermal head comprises: a heat radiation plate having a first face that is a substantially rectangular shape in a plan view, and a second face on a side opposite to the first face; a substrate which is attached to the heat radiation plate so as to extend from the first face to the second face via a first end interposed between the first face and the second face; a heat generation part which is located on the first face in the thermal head, and includes a plurality of heat generation elements; and a surface-mount component mounted on the second face in the substrate.SELECTED DRAWING: Figure 16

Description

[Technical Field]

[0001] The present invention relates to a thermal head used in printing by a thermal printer. [Background technology]

[0002] Thermal printers are known that sandwich a continuous label web, continuous tag web, or other print medium between a thermal head and a platen roller, and rotate the platen roller to transport and print on the print medium. Thermal printers use two printing methods: a thermal transfer printing method that uses a thermal transfer ink ribbon together with the print medium, and a thermal coloring method that uses so-called thermal paper with a thermal coloring layer (thermal layer) as the print medium. BACKGROUND ART Various proposals have been made for thermal heads and thermal printers (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-206267 Summary of the Invention [Problem to be solved by the invention]

[0004] Thermal printers are often used in retail environments such as supermarkets, where they are portable, and therefore must be waterproof. In particular, thermal heads are typically located near the outlet through which printed media, such as labels, are ejected, making them susceptible to water intrusion from the outlet. For example, in the printer described in Patent Document 1, the thermal head's driver IC is exposed to the thermal paper outlet, which could potentially cause malfunctions due to water intrusion from the paper outlet. Therefore, a thermal head with superior waterproofing compared to conventional printers is desired.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a thermal head that is more waterproof than conventional thermal heads. [Means for solving the problem]

[0006] One aspect of the present invention is A thermal head including a heat sink, a connector that receives signals from an external circuit board, and a heat generating unit that has a plurality of heat generating elements and performs printing by selectively energizing the plurality of heat generating elements based on signals transmitted from the external circuit board, further including a substrate that covers the heat sink so as to extend from the front surface to the rear surface of the heat sink, the heat generating unit being disposed on the front surface side of the heat sink on the substrate, and the connector being mounted on the rear surface side of the heat sink on the substrate. It is a thermal head. [Effects of the Invention]

[0007] According to one aspect of the present invention, it is possible to provide a thermal head that has better waterproofing than conventional thermal heads. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1A is a perspective view of a printer according to an embodiment when the printer cover is in a closed state, and FIG. 1B is a perspective view of a printer according to an embodiment when the printer cover is in an open state. [Figure 2] FIG. 1 is a perspective view of a printer according to an embodiment, with the printer cover open, the peeling unit open, and no roll paper loaded. [Figure 3] 10A and 10B are partial cross-sectional views for explaining continuous printing and peeling printing in the printer of the embodiment. [Figure 4] 10A and 10B are diagrams illustrating a mechanism by which the printer cover is opened by the cover opening button. [Figure 5] 10A and 10B are diagrams illustrating the positional relationship between a platen holding bracket and a group of levers. [Figure 6] 1A and 1B are perspective views of the peeling unit when opened and when closed. [Figure 7] FIG. 7 is a perspective view of the separation unit when opened, seen from a different viewpoint from that of FIG. 6. [Figure 8] 10A and 10B are diagrams illustrating the relationship between the peeling unit opening lever and the peeling unit during continuous printing and when the peeling unit opening button is operated. [Figure 9]10A and 10B are diagrams illustrating the relationship between the peeling unit opening lever and the peeling unit during continuous printing and when the peeling unit opening button is operated. [Figure 10] FIG. 10A is a plan view of the printer cover of the printer of this embodiment, and FIG. 10B is a cross-sectional view taken along line AA in FIG. 10A. [Figure 11] FIG. 10 is a partially enlarged cross-sectional view of the vicinity of the peeling roller during peeling. [Figure 12] 10A and 10B are diagrams illustrating an operation when folding the peeling unit. [Figure 13] 10A and 10B are diagrams illustrating an operation when folding the peeling unit. [Figure 14] 10A to 10C are diagrams sequentially illustrating operations when switching the printer of the embodiment from continuous issuance to peel-off issuance. [Figure 15] 10A to 10C are diagrams sequentially illustrating operations when switching the printer of the embodiment from continuous issuance to peel-off issuance. [Figure 16] FIG. 16A is a diagram showing the front side of the thermal head, and FIG. 16B is a diagram showing the rear side of the thermal head. [Figure 17] 16B is an enlarged cross-sectional view showing cross sections AA and BB of FIG. 16A. [Figure 18] FIG. 2 is a partial cross-sectional view of a printer including a bearing groove for a thermal head. [Figure 19] 10A to 10C are diagrams illustrating a method for replacing a thermal head. [Figure 20] 10A and 10B are diagrams showing protrusions provided on the internal frame and supporting the thermal head. [Figure 21] 20A and 20B are diagrams for explaining forces acting on a thermal head in a printer according to an embodiment, where FIG. 20A shows a cross section in a plane perpendicular to the up-down direction, and FIG. 20B shows a cross section in a plane perpendicular to the left-right direction. [Figure 22] FIG. 22A is a perspective view of a thermal head of another embodiment as seen from the front, and FIG. 22B is a perspective view of a thermal head of another embodiment as seen from the rear. [Figure 23] FIG. 10 is a perspective view of a plate-shaped member included in a thermal head according to another embodiment. [Figure 24] FIG. 23 is a perspective view of a thermal head according to another embodiment, seen from a different viewpoint than that of FIG. 22. [Figure 25] FIG. 10 is a side view showing the positional relationship between a thermal head and a platen holding bracket according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Printer 1 schematic configuration] A printer 1 according to one embodiment of the present invention is a label printer that is configured to be able to switch between continuous issuance and peel-off issuance. The printer 1 will be described in detail below with reference to the drawings. In each figure, the directions of up (UP), down (DN), left (LH), right (RH), front (FR), and rear (RR) are defined, as shown in the perspective views of Figures 1A and 1B, for example. However, these direction definitions are solely for the convenience of explaining the drawings and are not intended to limit the position of the printer of the present invention when in use. In this definition of direction, the "printer front-to-rear direction" means the front-to-rear direction of the printer 1. The "printer width direction" means the left-to-right direction or lateral direction of the printer 1.

[0010] Figures 1A, 1B, and 2 are each perspective views of a printer 1 according to an embodiment. Figure 1A shows the printer cover 3 in a closed state, while Figures 1B and 2 show the printer cover 3 in an open state. Figure 1B shows the printer with roll paper R installed, and Figure 2 shows the roll paper R and the state of the printer 1 before the roll paper R is installed.

[0011] 1A, the internal functional components of the printer 1 are protected by a main body case 2 and a printer cover 3. On the top surface of the printer 1, a discharge unit 20 for discharging labels is provided. The printer 1 can be used with the discharge section 20 facing upwards (horizontal placement), but it can also be used with the discharge section 20 facing sideways (vertical placement) by hooking the belt hook (not shown) on the bottom of the printer 1 onto the operator's belt or by attaching a shoulder belt (not shown) and hanging it over the operator's shoulder. A display panel 15 is provided in the main body case 2 in front of the discharge unit 20. The display panel 15 may be equipped with a touch panel input mechanism that accepts operation inputs from an operator. The display panel 15 is connected to a circuit board inside the printer 1, and outputs images that show, for example, the operating status of the printer 1 and a user interface related to the operation of the printer 1, based on display signals supplied from the circuit board.

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

[0013] The printer cover 3 is configured to be able to swing between an open position that exposes the interior of the printer 1 and a closed position that closes the interior of the printer 1. Operating the cover-opening button 51b on the main body case 2 opens the printer cover 3, as shown in Figure 1B. Opening the printer cover 3 exposes the roll paper chamber 9. The roll paper chamber 9 is a space that contains roll paper R (an example of a roll).

[0014] As shown in Figure 2, roll paper R is a strip-shaped continuous paper P wound into a roll. The continuous paper P has a strip-shaped backing sheet PM and a plurality of labels PL temporarily attached to the backing sheet PM at predetermined intervals. The label-attaching surface of the backing sheet PM is coated with a release agent such as silicone to enable the labels PL to be easily peeled off. In addition, position detection marks M indicating the reference positions of the labels PL are formed at predetermined intervals on the back side of the label-attaching surface of the backing sheet PM. The front side of the label PL is the printing surface on which information is printed, and is formed with a thermosensitive coloring layer that changes color to a specific color when it reaches a predetermined temperature range. The back side of the printing surface is an adhesive surface covered with adhesive, and the label PL is temporarily attached to the backing paper PM by sticking this adhesive surface to the label attachment surface of the backing 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 components that support the roll paper R in a freely rotatable state while in contact with both sides of the roll paper R, and guide the transport of the continuous paper pulled out from the roll paper R. It is preferable that the guides be movable along the width direction of the roll paper R so that their position can be changed according to the width of the roll paper R.

[0016] 2, the printer cover 3 is pivotally supported on 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 the hinge shaft 81 is provided with a torsion spring (not shown) that urges the printer cover 3 from the closed position toward the open position.

[0017] As shown in Figure 2, a platen roller 10 (an example of a transport roller) is axially supported at the tip of the printer cover 3 so that it can rotate freely in both forward and reverse directions. The platen roller 10 is a transport means that transports continuous paper P pulled out from the roll paper R, and is formed to extend in the width direction of the continuous paper P. A gear 10b is connected to one end of a platen shaft 10a of the platen roller 10. When the printer cover 3 is in the closed position, this gear 10b engages with a gear 22b arranged inside the main body case 2, and is mechanically connected via gear 22b to a stepping motor (not shown) or the like that drives the roller.

[0018] 2, a peeling bar 12 is installed on the printer cover 3 near the platen roller 10 and along the platen roller 10. The peeling bar 12 is a peeling member that peels the label PL from the backing paper PM, and both ends of the peeling bar 12 are fixed to both side walls of the printer cover 3. The peeling bar 12 may also be fixed to both ends of the platen shaft 10a. In one embodiment, the cross section of the peel bar 12 is substantially triangular, but is not limited to such and may be spherical or elliptical.

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

[0020] The thermal head 28 (an example of a print head) is a printing means that prints information such as characters, symbols, figures, or barcodes on labels PL that are temporarily attached to a backing sheet PM that is transported from the roll paper R. The thermal head 28 is disposed so as to face the platen roller 10 when the printer cover 3 is closed. As will be described later, a flexible cable that connects to a circuit board (not shown) is detachably attached to the thermal head 28. The thermal head 28 has 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 signals sent from the circuit board.

[0021] As shown in Figure 2, a coil spring 55 is disposed in front of the thermal head 28. One rear end of the coil spring 55 abuts against the thermal head 28, and the other front end of the coil spring 55 abuts against the internal frame (see also Figure 19). During printing, the coil spring 55 urges the thermal head 28 toward the platen roller 10, thereby pressing the thermal head 28 against the platen roller 10 with a pressure optimal for printing.

[0022] The printer 1 has a peeling unit 4, and performs continuous printing and peeling printing by moving the peeling unit 4 between a continuous printing position and a peeling printing position. As shown in FIG. 1B, when the printer cover 3 is in the open position, the peeling unit opening button 52b is exposed. The peeling unit 4 can be operated by operating the peeling unit opening button 52b. 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 the operator when switching from continuous issuance to peeling issuance.

[0023] As shown in Fig. 2, the peeling unit 4 has a peeling roller cover 41 and a peeling roller holder 42 that holds the peeling roller 45. The peeling roller cover 41 is configured to cover the peeling roller holder 42 when issuing continuous paper. The peeling roller cover 41 is journaled on an internal frame within the main body case 2, and swings from a closed position to an open position (the state shown in Fig. 2) in response to operation of the peeling unit opening button 52b. The peeling roller holding portion 42 is pivotally supported by the peeling roller cover 41. When issuing paper continuously, the peeling roller holding portion 42 is folded and stored under the rear surface of the peeling roller cover 41. The peeling unit 4 will be described in detail later.

[0024] The printer cover 3 is provided with a sensor 35. When the printer cover 3 is closed, the sensor 35 is disposed on the paper passage route of the continuous paper P pulled out from the roll paper R until it reaches the platen roller 10, and detects the position of the label PL. It is preferable to control the transport amount of the continuous paper P based on the detection result of this sensor 35.

[0025] Although not shown, it is preferable to provide a cutter that cuts the backing sheet PM of the continuous paper P after continuous printing. When a cutter is provided, the cutter is installed in the discharge section 20 in a state that it extends along the width direction of the continuous paper P. Also, the peel bar 12 may function as a cutter.

[0026] [Continuous issuance and peeling issuance] Next, continuous printing and peeling printing of the printer 1 will be described with reference to FIG. The printer 1 is configured to be switchable between peel-off issuing, in which labels are peeled off from a backing sheet of continuous paper and issued, and continuous issuing, in which labels are issued without being peeled off from the backing sheet.

[0027] For continuous issuance, a backing sheet with the required number of labels attached is prepared in advance, and the labels can be peeled off from the backing sheet and attached on-site, making it suitable for cases where the object to which the labels are to be attached is located far from the printer 1. For continuous issuance, the peeling unit 4 attached to the printer 1 is set to the continuous issuance position.

[0028] On the other hand, in peel-off issuance, labels are discharged one by one peeled from the backing paper, which is suitable when the object to which the label is to be affixed is close to the operator. For peel-off issuance, the peeling unit 4 attached to the printer 1 is set to the peel-off issuance position. As a result, when the platen roller 10 is rotated to transport the continuous paper for printing, the backing paper is transported while sandwiched between the peeling roller 45 and the platen roller 10, while the printed labels are peeled one by one from the backing paper and discharged outside the printer 1.

[0029] 3 is a partial cross-sectional view showing the positional relationship between the peeling unit 4, platen roller 10, peeling bar 12, and thermal head 28 during continuous printing and peeling printing. In FIG. 3, the peeling roller cover 41 and peeling roller holder 42 of the peeling unit 4 are shown by outlines only. The outline of the peeling roller cover 41 is shown by dotted lines. Furthermore, since the position of the peeling roller holding portion 42 differs between continuous issuance and peeling issuance, only the peeling roller holding portion 42 is shaded. The position of the peeling unit 4 during continuous issuing corresponds to the continuous issuing position, and the position of the peeling unit 4 during peeling issuing corresponds to the peeling issuing position.

[0030] As shown in Figure 3, during continuous printing, the peeling roller holder 42 is housed under the peeling roller cover 41, so that the peeling roller 45 is positioned away from the platen roller 10 and does not interfere with the discharge of the continuous paper P. The continuous paper P pulled out from the roll paper R is clamped between the platen roller 10 and the thermal head 28, and labels on the continuous paper P are printed.

[0031] When switching from continuous issuance to peel issuance, the peel roller holding unit 42 is moved around the shaft 42a to the swung position shown in Figure 3. As shown in Figure 3, during peel issuance, the peel roller 45 is positioned opposite the platen roller 10. In peel issuance, the continuous paper P pulled out from the roll paper R is sandwiched between the platen roller 10 and the thermal head 28, and labels on the continuous paper P are printed, just like in continuous issuance. In peel issuance, the liner PM of the continuous paper P pulled out from the roll paper R is made to make a sharp turn at the peel bar 12, and is sandwiched between the platen roller 10 and the peel roller 45 and discharged. As the liner PM makes a sharp turn at the peel bar 12, the label PL is peeled off from the liner PM and discharged.

[0032] [Printer cover 3 opening operation] Next, the opening operation of the printer cover 3 will be described with reference to Figures 4 and 5. The cover opening lever 51 and the peeling unit opening lever 52 will also be described.

[0033] 4 is a side view of the cover opening lever 51 when the printer cover is closed and when the cover opening button is operated, 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. Note that FIG. 4 shows, as an example, the case where the peeling unit 4 is in the continuous issuing position. As shown in Figure 4, when viewed from the side, the cover opening lever 51 and the peeling unit opening lever 52 are arranged opposite each other in the front-to-rear direction, but extend in the front-to-rear direction at different heights, resulting in an arrangement that is highly space-efficient.

[0034] 5 is a perspective view of the cover opening lever 51 when the printer cover is closed, the peeling unit opening lever 52, the platen holding bracket 27, and the peeling unit 4, as seen from the rear. The peeling unit 4 is not shown in FIG.

[0035] As shown in Fig. 1A, the cover opening lever 51 has a cover opening button 51b exposed to the outside. A shaft insertion hole 51a is formed in the cover opening lever 51, and this shaft insertion hole 51a is inserted into a shaft 56 (not shown in Fig. 5) provided on the internal frame. This allows the cover opening lever 51 to swing around the shaft 56. As shown in Fig. 5, the cover opening lever 51 has a protrusion 51c that protrudes inward.

[0036] 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 on an internal frame (not shown). This allows the platen holding bracket 27 to swing 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 engages 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 a protrusion 51c of the cover opening lever 51 is inserted into the hole 27c. Here, the hole 27c is formed larger than the protrusion 51c in a side view (i.e., the hole 27c has play), so the platen holding bracket 27 is able to swing. The platen holding bracket 27 swings around the shaft 27a, and the cover opening lever 51 swings around the shaft 56 (see FIG. 4), so the swing axes are different between the platen holding bracket 27 and the protrusion 51c. Therefore, by providing play in the hole 27c, the difference in the trajectories of the hole 27c and the protrusion 51c due to the difference in the swing axes is absorbed.

[0038] The peeling unit opening lever 52 is configured to be rotatable (or swingable) around the shaft 27a inserted into the boss 52a. That is, the platen holding bracket 27 and the peeling unit opening lever 52 share the shaft 27a, which is a single swing shaft, so there is no need to provide a separate swing shaft for the peeling unit opening lever 52, which contributes to space saving and cost savings. However, this is not limited to this, and in another embodiment, separate swing shafts may be set for the platen holding bracket 27 and the peeling unit opening lever 52.

[0039] A coil spring 53 (an example of a biasing member) is disposed between the peeling unit opening lever 52 and an internal frame (not shown) at a position directly below the peeling unit opening button 52b. When the peeling unit opening lever 52 is pressed (operated) downward against the restoring force of the coil spring 53, the peeling unit opening lever 52 swings around the shaft 27a (swings clockwise in FIG. 4). As will be described later, the peeling unit 4 swings via the engaging protrusion 523 in response to the swing of the peeling unit opening lever 52, moving from the closed position to the open position. When the downward pressing force of the peeling unit opening button 52b is released, the restoring force of the coil spring 53 causes the peeling unit opening lever 52 to return (swing) to the position before it was pressed.

[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 inner frame (not shown). When no external force is applied to the platen holding bracket 27, the platen holding bracket 27 is in the printer cover closed position shown in Figure 4, and holds the platen shaft 10a in the groove 27b. This position is a lock position that locks 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 (swings counterclockwise in FIG. 4) around the shaft 56. As the cover opening lever 51 swings, the protrusion 51c presses 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, the printer cover 3 to which the platen shaft 10a is attached is biased from the closed position toward the open position, so it moves to the open position when the platen shaft 10a disengages from the groove 27b due to the swing of the platen holding bracket 27. The position of the platen holding bracket 27 at this time is the unlocked position, which releases the lock on the printer cover 3 in the closed position.

[0042] Conversely, when closing the printer cover 3, the pressing force of the operator closing the printer cover 3 causes the platen shaft 10a attached to the printer cover 3 to press down on the inclined top of the platen holding bracket 27 against the restoring force of the coil spring 29. This causes the platen holding bracket 27 to swing clockwise in Figure 4, and the platen shaft 10a is inserted into the groove 27b of the platen holding bracket 27. With the platen shaft 10a inserted into the groove 27b, the restoring force of the coil spring 29 causes the platen holding bracket 27 to return to the locked position when the printer cover is closed, shown in Figure 4.

[0043] [Strip unit 4] Next, the peeling unit 4 will be described with reference to FIGS.

[0044] 6A and 6B are perspective views of the peeling unit 4 when it is open and when it is closed. Note that the peeling unit 4 when it is closed in Fig. 6A is in the continuous issuing position. The open position of the peeling unit 4 is the position where the peeling roller cover 41 is opened in response to the operation of the peeling unit opening button 52b.

[0045] As shown in FIG. 2, the open position of the peeling roller cover 41 is a position that exposes at least a portion of the interior of the printer 1, in other words, at least a portion of the interior of the main body case 2. For example, as shown in FIG. 2, when the peeling roller cover 41 is in the open position, the coil spring 55 inside the main body case 2 and the flexible cable 57 (see FIG. 21) connected to the thermal head 28 are in an open state. From another perspective, the open position of the peeling roller cover 41 can be said to be a position that exposes the thermal head 28 inside the main body case 2. From yet another perspective, the open position of the peeling roller cover 41 can be said to be a position that allows the peeling roller cover 41 to be opened when the peeling roller holder 42 is in 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 (open), the peeling roller holder 42 protrudes 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 portion of the interior of the printer 1 that is open when the peeling roller cover 41 is in the open position, in other words, at least a portion of the interior of the main body case 2 that is open when the peeling roller cover 41 is 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, flexible cable 57, etc. are not visible from the outside and the cover is in a closed state. From another perspective, the closed position of the peeling roller cover 41 can also be said to be a position that closes at least a portion of the thermal head 28 inside the main body case 2. From yet another perspective, the closed position of the peeling roller cover 41 can also be said to be a position that, when the peeling roller holder 42 is positioned facing the back surface of the peeling roller cover 41, keeps the peeling roller cover 41 in that position without opening it. When the peeling roller cover 41 is in the closed position, the position of the peeling roller holder 42 differs between continuous printing and peeling printing. As shown in FIG. 6, when the peeling roller cover 41 is in the closed position (closed) during continuous printing, the peeling roller holding portion 42 is housed under the peeling roller cover 41 (housed state).

[0047] Referring to FIG. 6, the peeling roller cover 41 is a swinging member having a pair of shafts 41a (an example of first shafts) and configured to be swingable around the shafts 41a. The shafts 41a have a circular cross section and are inserted into a cylindrical portion (not shown) provided in the internal frame, allowing for rotation. The cylindrical portion preferably has a long hole formed in the front-to-rear direction of the printer so that the shafts 41a can be slightly displaced inside the cylindrical portion, for example, in the front-to-rear direction of the printer. This allows for play in the front-to-rear direction of the printer when the shafts 41a are inserted into the cylindrical portion, improving the impact resistance of the printer 1 against a fall, etc. The direction of the elongated hole formed in the cylindrical portion is not limited to the front-rear direction of the printer, but can be set in any direction within a plane perpendicular to the left-right direction of the printer 1, such as the up-down direction of the printer 1, for example.

[0048] The peeling roller cover 41 extends in the same direction as the platen roller 10. 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. The back surface 412 has a recess formed therein 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-to-rear direction, which is convenient for cutting the backing paper when a cutter is provided in the discharge portion 20. An engagement hole 415 is formed in the vicinity of the shaft 41a in the peeling roller cover 41. 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 abutment portions) may be provided on the side of the peeling roller cover 41. When the shaft 41a is in the closed position, the U-shaped grooves 413 abut against the protrusions 26 (see FIG. 18) formed on the inner frame. The U-shaped grooves 413 abut against the protrusions 26, thereby functioning to position the peeling unit 4 in the up-down direction. When the U-shaped grooves 413 abut against the protrusions 26, a predetermined gap is provided between the peeling unit 4 and the thermal head 28. This reliably prevents interference between the peeling unit 4 and the thermal head 28. As described above, the shaft 41a of the peeling unit 4 is preferably inserted into a slot formed in the cylindrical portion of the inner frame in the front-to-rear direction of the printer, thereby providing play in the front-to-rear direction of the printer. At this time, the U-shaped groove 413 abuts and engages with the protrusion 26 (see FIG. 18 ), thereby preventing the peeling unit 4 (peeling roller cover 41) from shifting in the front-to-rear direction of the printer due to play in the shaft 41a inserted in the slot (i.e., it functions to position the peeling unit 4 in the front-to-rear direction of the printer).

[0050] It should be noted that it is not essential to provide the U-shaped groove 413 and the protrusion 26. The shape of the contact portion can be formed as appropriate as long as a part of the peeling unit 4 and the internal frame are in contact with each other while maintaining a gap between the peeling unit 4 and the thermal head 28. Instead of such an abutment structure, the peeling unit 4 can be positioned in the up-down direction by, for example, restricting the movable range of the shaft 41a of the peeling roller cover 41.

[0051] A peel sensor 47 is disposed on the surface 411 of the peel roller cover 41. The peel sensor 47 is a light reflective sensor that detects the presence or absence of a peeled label when a peel is issued. In Figure 3, the label PL peeled by the peel bar 12 is controlled to be conveyed so that a portion of the label PL on the upstream side in the conveying direction stops near the peel bar 12. The peeled label PL remains on the peel bar 12 due to its adhesive force, and the presence or absence of this label PL is detected by the peel sensor 47. When the operator removes the peeled label, the peel sensor 47 detects the absence of the label PL and controls to issue the next label.

[0052] Referring to FIG. 6, the peeling roller holding portion 42 is a member that holds the peeling roller 45. The peeling roller holding part 42, like the peeling roller cover 41, extends in the same direction as the platen roller 10. The pair of shafts 42a of the peeling roller holding part 42 are arranged inside the pair of shafts 41a of the peeling roller cover 41 so that the peeling roller holding part 42 can be housed under the back surface 412 of the peeling roller cover 41, and the width of the peeling roller holding part 42 is narrower than the width of the peeling roller cover 41.

[0053] The peeling roller holding part 42 is a swinging member having a pair of shafts 42a (an example of second shafts) and configured to be swingable around the shafts 42a. The pair of shafts 42a are journaled to 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 shafts 42a. Therefore, as shown in FIG. 6, when the peeling unit 4 is opened, the peeling roller 45 protrudes significantly upward from the shafts 41a.

[0054] That is, the peeling roller holding unit 42 can swing between a housed position (an example of a first position of the peeling roller holding unit) where the peeling roller 45 is housed under the peeling roller cover 41, and a protruding position (an example of a second position of the peeling roller holding unit; the open position 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 unit 42 is a position facing the back surface 412 of the peeling roller cover 41, and is also a position where it is covered by the peeling roller cover 41. When storing 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 then the entire peeling roller cover 41 and the peeling roller holding part 42 are swung around the shaft 41a. As a result, the peeling roller holding part 42 is folded and stored compactly under the peeling roller cover 41.

[0055] On the other hand, when the peeling roller cover 41 is in the open position, the peeling roller holding part 42 can swing between the housed position and the protruding position. Furthermore, as described below, the peeling roller holding part 42 is biased from the housed position toward the protruding position by the coil spring 43. Therefore, as soon as the peeling roller cover 41 moves from the closed position to the open position, the peeling roller holding part 42 moves in a pop-out manner from the housed position toward the protruding position. This allows the operator to immediately switch from continuous issuance to peeling issuance. Furthermore, when the peeling roller holding portion 42 is in the protruding position, the peeling roller 45 protrudes highly, which allows the peeling roller 45 to be moved far away when the peeling unit 4 is set to the peeling issuing position.

[0056] A pair of arms 421 extend from a pair of shafts 42a. A shaft 45a that rotates the peeling roller 45 and auxiliary roller 46 is disposed at the tip of the pair of arms 421. The diameter of each auxiliary roller 46 is smaller than the diameter of the peeling roller 45. By providing auxiliary rollers 46 on both sides of the peeling roller 45, it is possible to smoothly discharge a wide liner when peeling and issuing a wide label. In other words, without the auxiliary rollers 46, the wide liner would move in the width direction (left and right), but by providing the auxiliary rollers 46, it is possible to transport the wide liner stably. It is not essential to provide the auxiliary roller 46. Even if the auxiliary roller 46 is not provided, peeling and issuing can be performed as long as the peeling roller 45 is provided. An outwardly protruding projection 422 is formed on each arm 421. As will be described later, the projection 422 is provided to engage the peeling unit 4 with the printer cover 3 when peeling is performed.

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

[0058] 7 is a perspective view of the peeling unit 4 in an open state, seen from a different perspective than that of FIG. 6. When the peeling roller holding part 42 is in the protruding position, a part of the arm 421 of the peeling roller holding part 42 abuts against the surface 411 of the peeling roller cover 41. In other words, the surface 411 of the peeling roller cover 41 functions as a stopper for the peeling roller holding part 42, which is swung by the coil spring 43.

[0059] Next, the operation when the peeling unit 4 is moved from the continuous issuing state to the open position will be described with reference to FIGS. 8 and 9 are side views of the peeling unit opening lever 52 and the peeling unit 4, and states S1 to S3 are shown in chronological order in the side views. State S1 indicates the state when the printer cover 3 is open during continuous printing, state S2 indicates the state when the peeling unit opening button is continuously pressed, and state S3 indicates the state when the peeling unit opening button is released.

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

[0061] When the peeling unit opening button 52b is pressed (operated), the peeling unit opening lever 52 swings clockwise around the shaft 27a in FIG. 8. As a result, the engaging protrusion 523 of the peeling unit opening lever 52 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 part 42 is biased by the coil spring 43 (see FIG. 6) in the swing direction from the housed position toward the protruding position. Therefore, when the peeling roller cover 41 swings toward the open position, the position restriction of the peeling roller holding part 42 by the second stopper 522 (described later) is released, creating a space in which the peeling roller holding part 42 can swing. As a result, the peeling roller holding part 42 swings to the protruding position as shown in state S2 in FIG. 8.

[0062] 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, the printer 1 is provided with a space that allows the peeling roller holding part 42 to swing from the housed position to the protruding position when the peeling roller cover 41 is in the open position. Therefore, the biasing force of the coil spring 43 allows the peeling roller holding part 42 to protrude upward with force.

[0063] When the peeling unit opening button 52b is released from the state shown in state S2, the restoring force of the coil spring 53 causes the peeling unit opening lever 52 to swing counterclockwise around the shaft 27a in FIG. 8. This causes the peeling unit opening lever 52 and the peeling roller cover 41 to return to the positions of state S1. However, once the peeling roller holder 42 has swung to the extended position, it remains in the extended position without returning to the retracted position. As a result, the peeling unit 4 assumes the configuration shown in state S3 in FIG. 9.

[0064] [Engagement of peeling unit 4 and printer cover 3] In the printer 1, by swinging the printer cover 3 from the open position to the closed position when in state S3 of FIG. 9, the printer cover 3 and the peeling unit 4 can be engaged and the peeling unit 4 can be set to the peeling issuing position. Therefore, the engagement between the peeling unit 4 and the printer cover 3 when peeling is performed will be described below with reference to FIGS. 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 AA of Fig. 10A.

[0065] 10A, the printer cover 3 has at its front end a pair of peeling unit receiving portions 31. The peeling unit receiving portions 31 are provided near the positions where the platen roller 10 and the peeling bar 12 are supported. As shown in Figure 10B, a guide groove 31p that is open at the front is formed in the peeling unit receiving portion 31. The guide groove 31p is a groove that is open only on the inside 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 Figure 9) of the peeling unit 4 that is located in front when the printer cover 3 is being closed.

[0066] A roller pressing mechanism 37 is provided inside the guide groove 31p. As will be described later, the roller pressing mechanism 37 presses the peeling roller 45 toward the platen roller 10 when the printer cover 3 is in the closed position, thereby generating nip pressure when the peeling roller 45 and the platen roller 10 sandwich the backing paper. 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 to the closed position, the protrusion 422 of the peeling unit 4 is guided to the contact portion 32.

[0067] When the printer cover 3 is moved from the open position to the closed position in state S3 in Figure 9, 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 moves. As the printer cover 3 swings to the closed position, the protrusion 422 advances toward the rear of the printer cover 3 along the guide groove 31p and comes into contact with 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 positioned opposite the platen roller 10. Therefore, by simply closing the printer cover 3, the operator can engage the printer cover 3 with the peeling unit 4 and move the peeling unit 4 to the peeling issuing position.

[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 to the peeling issuing position. As shown in Figure 11, when the printer cover 3 is in the closed position, the peeling roller 45 of the peeling unit 4 is positioned opposite the platen roller 10. The protrusion 422 of the peeling unit 4 abuts against the abutment portion 32 of the peeling unit receiving portion 31 of the printer cover 3, and the coil spring 33 behind the abutment portion 32 is compressed. The restoring force of the coil spring 33 acts on the peeling roller 45 through the protrusion 422, pressing the peeling roller 45 against the platen roller 10 to generate nip pressure when nipping the backing sheet. As a result, the force in the rotational direction around the shaft 42a of the peeling roller holding portion 42 (F5c in Figure 11) is converted into nip pressure between the peeling roller 45 and the platen roller 10.

[0069] 11, in a side view, the normal direction (direction indicated by F5b) of the contact surface of the contact portion 32 with which the protrusion 422 contacts may be the same as the direction from the center of the peeling roller 45 toward the center of the platen roller 10, but is not limited to being the same because the direction of the force F5 changes depending on the angle at which the protrusion 422 contacts the contact portion 32. As shown in Fig. 11, the component force F5b, which is the normal component with respect to the contact surface of the reaction force F5 of the contact portion 32 acting on the protrusion 422, presses the peeling roller 45 against the platen roller 10, making it possible to more effectively generate nip pressure when nipping the backing sheet.

[0070] [Operation of storing the peeling roller holding unit 42] Next, with reference to FIGS. 12 and 13, an operation when the peeling roller holding portion 42 in the protruding position is housed under the peeling roller cover 41 and the peeling unit 4 is set to the continuous issuing position will be described. To switch from peeling issuance to continuous issuance, the cover opening button 51b is pressed to open the printer cover 3, and the peeling unit opening button 52b is pressed. Then, as shown in state S2 in Fig. 8, the peeling roller cover 41 swings to the open position, and the peeling roller holding part 42 swings to the protruding position. In this state, the operator can fold the peeling roller holding part 42 and store it under the peeling roller cover 41 (folding operation), thereby setting the peeling unit 4 to the continuous issuance position.

[0071] 12 and 13 are perspective views showing the peeling unit opening lever 52 and the peeling unit 4 in time sequence when the operator performs the folding operation of the peeling unit 4. In FIGS. 12, the peeling unit opening 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 spaced apart from each other in the front and rear, and are provided to restrict the swing of the arm 421 of the peeling roller holding portion 42 by abutting against the arm 421.

[0072] State S5 in Fig. 12 is a state in which the peeling roller cover 41 is in the open position and the peeling roller holding part 42 is in the protruding position, which is the same as state S2 in Fig. 8. This state is maintained by the operator continuing to press the peeling unit opening 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 housed position below the back surface 412 of the peeling roller cover 41, the state changes to state S6. At this time, the operating force causes the part of the arm 421 farthest from the shaft 42a to climb 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). In other words, when the peeling roller holding part 42 is located in the housed position and the peeling roller cover 41 is located in the open position, the first stopper 521 abuts against the arm 421 to restrict the swinging of the peeling roller holding part 42. The first stopper 521 restricts the swinging of the peeling roller holding part 42, making it easy to move the peeling roller cover 41 to the closed position while keeping the peeling roller holding part 42 in the housed position. Without the first stopper 521, the operator would have to release the pressure on the peeling unit opening button 52b to move the peeling roller cover 41 to the closed position while holding the peeling roller holding part 42 with his / her hand to prevent it from swinging from the housed position. In other words, providing the first stopper 521 improves operability.

[0074] When the operator releases the peeling unit opening button 52b while the peeling roller holding portion 42 is locked in the housed position by the first stopper 521, the peeling roller cover 41 starts moving toward the closed position. State S7 shows the state in which the peeling roller cover 41 is on its way to the closed position. In the process of the peeling roller cover 41 moving toward the closed position, the restriction on the swinging of the arm 421 by the first stopper 521 is released in accordance with the swinging of the peeling roller cover 41. In other words, the outer edge of the arm 421 is formed so that the restriction on the swinging of the arm 421 is released when the peeling roller cover 41 is closed to a predetermined angle.

[0075] 13 is the state at which the operator further closes the peeling roller cover 41 from state S7. The peeling roller holding part 42, whose swing restriction by the first stopper 521 has been released, swings due to the restoring force of the coil spring 43, but the swing is again restricted by the second stopper 522 located behind the first stopper 521. In other words, the second stopper 522 abuts against the arm 421 while the peeling roller holding part 42 moves from the open position to the closed position, thereby restricting the swing of the peeling roller holding part 42 at a position between the housed position and the protruding position. State S9 is a state in which the peeling roller cover 41 is in the closed position, and the peeling unit 4 is in the continuous issuing position. Providing the second stopper 522 prevents the peeling roller holding part 42 from swinging while the peeling roller cover 41 moves from the open position to the closed position. Furthermore, since the second stopper 522 is located behind the first stopper 521, as shown in state S9, when the peeling unit opening button 52b is operated while 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] It should be noted that it is not absolutely necessary to provide the first stopper 521 and the second stopper 522. Providing just one of the stoppers contributes to improved operability. Even if neither the first stopper 521 nor the second stopper 522 is provided, it is possible to fold the peeling unit 4. That is, the operator can store the peeling roller holding part 42 under the peeling roller cover 41 by manually stopping the peeling roller holding part 42 in the stored position and carefully moving the peeling roller cover 41 to the closed position.

[0077] [Switching between continuous printing and peel printing on Printer 1] Next, the switching operation between continuous printing and peeling printing of the printer 1 will be described with reference to FIGS. 14 and 15 show side views of the main parts of the printer 1 in chronological order when switching from continuous issuance to peel-off issuance. Note that the platen holding bracket 27 is not shown in FIG.

[0078] State S10 in Figure 14 shows the state of the printer 1 during continuous printing. In this state, the printer cover 3 is held in place by the platen shaft 10a of the platen roller 10, which is journaled on the printer cover 3, fitting into the groove 27b of the platen holding bracket 27. In state S10, the peeling unit 4 is set to the continuous printing position.

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

[0080] Next, when the operator closes the printer cover 3, the protrusion 422 of the peeling roller holding portion 42, which is in the protruding position, is inserted into the guide groove 31p (see Figure 10) of the printer cover 3 and guided along the guide groove 31p, thereby engaging the printer cover 3 and the peeling unit 4, as shown in state S14.

[0081] As shown in state S15, when the printer cover 3 is in 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 to the peeling issuing position. That is, the peeling roller 45 of the peeling unit 4 is positioned opposite the platen roller 10, and together with the platen roller 10, it holds the backing sheet PM. 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), generating an appropriate nip pressure between the peeling roller 45 and the platen roller 10. In peel-off issuance, the label PL printed by the thermal head 28 is peeled off from the liner PM by causing the liner PM to turn sharply with the peel bar 12. The peel roller 45 rotates in accordance with the rotation of the platen roller 10, and discharges the liner PM.

[0082] To switch from peeling issuance to continuous issuance, press the cover opening button 51b to open the printer cover 3, and then press the peeling unit opening button 52b. This causes the peeling roller cover 41 of the peeling unit 4 to swing to the open position, and the peeling roller holding part 42 to swing to the protruding position. Thereafter, as described with reference to Figures 12 and 13, the peeling unit 4 is folded, and the peeling unit 4 is set to the continuous issuance position.

[0083] As described above, the printer 1 according to one embodiment is provided with a peeling unit 4 that is movable between a continuous issuing position and a peeling issuing position, and when the peeling unit 4 is in the continuous issuing position, the peeling roller holding portion 42 that holds the peeling roller 45 can be compactly stored in a storage position below the back surface of the peeling roller cover 41. To switch from continuous printing to peeling printing, simply open the printer cover 3, operate the peeling unit release button 52b to move the peeling roller holder 42 to the protruding position, and then close the printer cover 3. In other words, switching can be done in three simple steps, providing excellent operability. Moreover, when the printer cover 3 is in the closed position, the roller pressing mechanism 37 of the printer cover 3 presses the peeling roller 45 against the platen roller 10, generating an appropriate nip pressure. Conversely, when switching from peeling issuance to continuous issuance, the printer cover 3 is opened, the peeling unit opening button 52b is operated to move the peeling roller holding part 42 to the protruding position, the peeling roller holding part 42 is folded to move to the housed position, and the printer cover 3 is closed. This operation is also simple.

[0084] [How to install and remove the thermal head 28] Next, a method for attaching and detaching the thermal head 28 to and from the printer 1 will be described with reference to FIGS. Fig. 16A is a diagram showing the front side (an example of the first side) of the thermal head 28, which is biased by a coil spring 55, and Fig. 16B is a diagram 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 an enlarged cross-sectional view showing cross sections AA and BB of Fig. 16A.

[0085] 16 and 17, the thermal head 28 has a structure in which a substrate 282 is attached to a heat sink 281 (an example of a base) that is substantially rectangular in plan view. The heat sink 281 is made of a metal material with high thermal conductivity, such as aluminum. As can be seen from the AA cross section in FIG. 17, the substrate 282 (an example of a coating layer) is attached to the heat sink 281 so as to extend from a front surface 281a of the heat sink 281 to a back surface 281b on the opposite side of the front surface 281a, via a first end 281e1 interposed between the front surface 281a and the back surface 281b. The substrate 282 is, for example, a ceramic substrate. The area of ​​the heat sink 281 that is occupied by the substrate 282 is an example of a covered area. The front surface 281a (the surface facing the rear of the printer 1) is an example of a first surface, and the back surface 281b (the surface facing the front of the printer 1) is an example of a second surface. 16B and the BB cross section of FIG. 17, a notch 283c (an example of an opening and an uncovered area) is provided at a substantial center position in the longitudinal direction (horizontal 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 protrusion 211 (see FIG. 19) for enabling the thermal head 28 to swing is in contact with the notch 283c.

[0086] 16A and 17, surface-mounted devices (SMD) 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 a substrate 282 attached to a rear surface 281b of a heat sink 281. When 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 of the printer 1 (not shown) to the thermal head 28. When the thermal head 28 is attached to the printer 1, the relatively tall surface-mounted components (such as the connector 285, EEPROM 286, and diode 287 in FIG. 16A) mounted on the rear surface 281b of the heat sink 281 face the front of the printer 1, and can therefore be protected from moisture and the like that may infiltrate from the discharge section 20, which is located behind the thermal head 28. A drive IC (not shown) is mounted near the heat-generating section 284 on the rear side of the thermal head 28 facing the discharge section 20 (the side on which the surface 281a of the heat sink 281 is located), but because the drive IC is short, the drive IC and wiring, along with the heat-generating section 284, are protected by a protective layer or coating layer, so there is no problem even if moisture infiltrates from the discharge section 20.

[0087] 16B, the rear side of the thermal head 28 (the side where the heat generating portion 284 is located) does not have tall surface-mounted components such as connectors, so the conveyance angle of the label PL relative to the heat generating portion 284 can be made small (that is, an angle close to perpendicular to the heat generating portion 284 when viewed from the side) (see FIG. 3). Therefore, it is possible to improve the print quality for the following reasons. The heating portion 284 has a convex shape overall because it includes a glaze layer (partial glaze), which is generally convex. If a tall surface-mounted component is placed behind the thermal head 28, the conveyance angle of the label PL relative to the heating portion 284 will be large to avoid the surface-mounted component. In this case, the label PL tends to float above the heating portion 284 due to the convex shape of the heating portion 284 and the rigidity (stiffness) of the label PL, making it difficult to apply an optimal printing pressure to the label PL between the heating portion 284 and the platen roller 10. On the other hand, if the conveyance angle of the label PL relative to the heating portion 284 is small, even if the heating portion 284 is convex, the label PL can be clamped between the heating portion 284 and the platen roller 10 with an appropriate printing pressure near the top of the heating portion 284, thereby improving print quality.

[0088] A pair of shafts 28a extending outward are connected to both end surfaces 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, the shafts 28a include a large-diameter portion connected to the heat sink 281 and a small-diameter portion extending outward from the large-diameter portion, giving the shafts 28a a high strength. The small-diameter portion of the shafts 28a is inserted into the bearing grooves 25, which will be described later.

[0089] 18 is a partial cross-sectional view of the printer 1 taken along a plane perpendicular to the left-right direction in a state in which the peeling roller cover 41 is in the open position and the peeling roller holding part 42 is in the protruding position by continuing to press the peeling unit opening button 52b. In FIG. 17, the thermal head 28 and the coil spring 55 are not shown so that the bearing 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 groove 25 is formed in the internal frame of the printer 1. Note that Fig. 18 only shows the bearing groove 25 that receives one of the pair of shafts 28a of the thermal head 28, but the bearing groove 25 that receives the other shaft 28a is formed in the same way.

[0090] 18, the bearing receiving groove 25 has a first groove 251 and a second groove 252. Here, positions P1 and P2 respectively indicate imaginary positions that the shaft 28a can take within the bearing receiving groove 25. In this disclosure, when the shaft 28a is at positions P1 and P2, it may be expressed as the thermal head 28 being at positions P1 and P2, respectively.

[0091] The first groove 251 extends from position P1 (an example of a first position of the print head) in the direction in which the thermal head 28 is attached or detached. The second groove 252 extends from position P1 to position P2 (an example of a second position of the print head) in the direction in which the coil spring 55 in front of the thermal head 28 urges the thermal head 28 (i.e., rearward; an example of the first direction). By making the bearing receiving groove 25 an L-shaped groove consisting of the first groove 251 and the second groove 252, it is possible, with a relatively simple shape, to switch between a position (position P2) in which the thermal head 28 cannot be removed by moving it upward and a position (position P1) in which the thermal head 28 can be removed by moving it upward.

[0092] The thermal head 28 can be displaced between positions P1 and P2 in the direction in which the coil spring 55 urges the thermal head 28. Therefore, when attaching the thermal head 28, if the shaft 28a is inserted along the first groove 251 to position P1, the urging force of the coil spring 55 can easily set the thermal head 28 to position P2.

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

[0094] To remove the thermal head 28 to be replaced, as shown in state S21, the thermal head 28 to be replaced is moved from position P2 in the direction (forward) opposite to the first direction (i.e., the direction in which the coil spring 55 biases the thermal head 28) to position P1 against the biasing force of the coil spring 55. Next, the thermal head 28 to be replaced is moved upward (an example of a second direction) from position P1 to disengage the shaft 28a of the thermal head 28 to be replaced from the bearing groove 25, and the thermal head 28 to be replaced is removed. At this point, the flexible cable 57 is connected to the connector 285 of the thermal head 28 to be replaced (see FIG. 21B), so the flexible cable 57 is disconnected from the connector 285 of the thermal head 28 to be replaced. After the replacement thermal head 28 has been separated from the flexible cable 57, a new thermal head 28 can be attached to the printer 1 by following the steps in reverse order to the removal procedure. That is, first, the separated flexible cable 57 is connected to the connector 285 of the new thermal head 28 (see FIG. 16A). Then, when the new thermal head 28 is inserted into position P1, the urging force of the coil spring 55 moves the thermal head 28 from position P1 to position P2. That is, the new thermal head 28 is moved downward (an example of a direction opposite to the second direction) to insert the shaft 28a of the new thermal head 28 from the first groove 251 (see FIG. 18) into the bearing groove 25. At this time, the rear surface 281b (the surface facing the front of the printer 1) of the new thermal head 28 pushes the tip of the coil spring 55 (the rear end of the coil spring 55) forward (in a direction against the urging force of the coil spring 55) while inserting the new thermal head 28. When the shaft 28a of the new thermal head 28 reaches position P1, the urging force of the coil spring 55 allows the shaft 28a to be moved to position P2 without any operating force. The replacement of the thermal head 28 is carried out as described above.

[0095] 16B, no surface-mounted components such as connectors are located on the rear side of the thermal head 28 (the side where the heat-generating portion 284 is located), which has the advantage of facilitating the replacement of the thermal head 28. Coupled 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 will interfere with the rear internal frame (e.g., wall surface 21; see FIG. 20), making it difficult to smoothly insert the thermal head 28 into the bearing groove 25. In contrast, because the rear side of the thermal head 28 is flat, a new thermal head 28 can be smoothly inserted into the bearing groove 25 under the biasing force of the coil spring 55.

[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 that covers at least a portion of the thermal head 28, whereas when the peeling unit 4 is in the open position, it is in a position that does not cover the thermal head 28, as shown in Fig. 2. The thermal head 28 is attached and detached 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 portion of the thermal head 28.

[0097] 18 again, when the peeling roller cover 41 is in the open position (i.e., the peeling unit 4 is in the open position), a space is formed in which the thermal head 28, with its shaft 28a located at position P1, can be attached and detached. Therefore, when the operator wants to remove the thermal head 28 from the printer 1, they simply open the printer cover 3 and hold down the peeling unit opening button 52b to place the peeling unit 4 in the position shown in FIG. 18, and then, as described above, slide the shaft 28a of the thermal head 28 from position P2 to position P1 against the biasing force of the coil spring 55, and then pull the thermal head 28 upward. 2, in the printer 1 of this embodiment, at least a portion of the rear side of the thermal head 28 is exposed to the roll paper chamber 9, so that by temporarily removing the roll paper R, a working space can be secured when removing the thermal head 28, making it even easier to remove the thermal head 28. That is, when sliding the shaft 28a of the thermal head 28 from position P2 to position P1, the operator must apply an operating force to the thermal head 28 from rear to front, but the space behind the thermal head 28 makes it easy to apply the operating force. Also, when the operator attempts to pull the thermal head 28 upward, the space behind the thermal head 28 makes it easy to reach into that space and perform the pulling operation.

[0098] Attaching the thermal head 28 to the printer 1 is the reverse of the operation of removing the thermal head 28 from the printer 1. Similarly, with the peeling unit 4 in the state shown in Fig. 18, by inserting the shaft 28a of the thermal head 28 from the first groove 251 of the bearing groove 25 to position P1 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) with the back surface 281b of the thermal head 28 (the surface facing the front of the printer 1), the thermal head 28 moves to position P2 due to the biasing force of the coil spring 55. Therefore, the thermal head 28 can be easily replaced without using any tools.

[0099] In another embodiment, the bearing groove may have a different shape than the L-shape. For example, the bearing groove may have a groove extending diagonally forward or diagonally backward from position P1, as long as the thermal head 28 can be attached and detached from position P1. Although this may make attachment and detachment somewhat more difficult, the bearing groove may have a U-shaped groove path between positions P1 and P2, starting at position P1 in FIG. 18 , moving forward, slightly downward, and then rearward to position P2. In this case, the operator can remove the shaft 28a of the thermal head 28 by moving the shaft 28a along the U-shaped groove from position P2 to position P1.

[0100] [Support structure of thermal head 28] Next, the support structure of the thermal head 28 will be described with reference to FIGS. First, the structure of the internal frame behind the thermal head 28 will be described with reference to Figure 20. Figure 20 is a perspective view showing part of the internal frame together with the components attached to the internal frame, with a portion shown enlarged. Note that Figure 20 does not show the thermal head 28.

[0101] As shown in Figure 20, the internal frame has a wall 21 behind the area where the thermal head 28 is located (on the roll paper storage chamber 9 side) that faces the rear surface of the thermal head 28. A protrusion 211 is formed on the wall 21. The protrusion 211 (an example of an abutment portion) abuts against the rear surface of the thermal head 28 when the thermal head 28 is installed. As shown in Figure 20, the abutment surface of the protrusion 211 is preferably curved so that it is convex toward the rear surface of the thermal head 28.

[0102] 21A and 21B are diagrams illustrating the forces acting on the thermal head 28 in the printer 1 of this embodiment, with Fig. 21A showing a cross section in a plane perpendicular to the up-down direction and Fig. 21B showing a cross section in a plane perpendicular to the left-right direction. Note that Fig. 21A and Fig. 21B are on different scales. 21A, the protrusion 211 is provided at a position that abuts substantially the center in the left-right direction of the thermal head 28 when the thermal head 28 is mounted. In addition, the protrusion 211 is provided at a position on the rear side of the thermal head 28 that abuts substantially the center position of the pair of coil springs 55 in the left-right direction.

[0103] As described above, a notch 283c (see FIG. 16B) is provided in approximately the center of the thermal head 28 in the left-right direction, and the protrusion 211 abuts against the thermal head 28 at the notch 283c. The notch 283c is not covered by the substrate 282, and is a portion where the heat sink 281 of the thermal head 28 is exposed, so that the thermal head 28 can be supported more stably. It should be noted that it is not essential to provide the notch 283c. The protrusion 211 may support the thermal head 28 in the area of ​​the substrate 282 without providing the notch 283c.

[0104] It is preferable that the rear surface of the thermal head 28 is provided with a recess having a shape corresponding to the protrusion 211 at a position where the thermal head abuts against the protrusion 211. This makes it difficult for the position where the thermal head abuts against the protrusion 211 to shift, and allows the thermal head 28 to be supported more stably. In one embodiment, a recess may be provided on the wall surface 21 of the internal frame, and a protrusion 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 protrusion 211 shown in Fig. 20 is merely an example, and other shapes may be adopted as long as they can swingably support the thermal head 28. For example, instead of the shape shown in Fig. 20, the outer shape of the protrusion 211 may be a part of a spherical surface.

[0105] 21A, when the printer 1 is viewed in plan, restoring forces F1 and F2 from a pair of coil springs 55 acting rearward act on the front side of the thermal head 28, and a reaction force F3 acts from the protrusion 211 abutting the rear side of the thermal head 28. Here, the protrusion 211 is located approximately in the center when viewed from above the printer 1, so the thermal head 28 is configured to be able to swing clockwise and counterclockwise in FIG. 21A with the protrusion 211 as a fulcrum.

[0106] As shown in Fig. 21B, when the printer 1 is viewed from the side, restoring forces F1 and F2 (F2 is not visible in Fig. 21B) acting rearward from a pair of coil springs 55 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 points of action of the restoring forces F1 and F2, and a reaction force F3 from the protrusion 211 acts on the rear side of the thermal head 28 below the points of action of the restoring forces F1 and F2. Therefore, the thermal head 28 is configured to be able to swing clockwise and counterclockwise in Fig. 21B with the protrusion 211 as a fulcrum.

[0107] Moreover, when viewed from the side of the printer 1, the point at which the biasing force of the coil spring 55 acts on the thermal head 28 is between the position at which the thermal head 28 receives the reaction force from the platen roller 10 and the position at which the protrusion 211 supports the rear side of the thermal head 28. Therefore, the biasing force of the coil spring 55 is received from above and below, so the thermal head 28 can be supported in a well-balanced manner.

[0108] 21B, it is preferable that the surface on the rear side of the thermal head 28 that contacts the protrusion 211 (i.e., the surface where the heat sink 281 is exposed by the cutout 283c) and the surface that corresponds to the heat generating portion 284 are on the same reference plane. This allows the heat generating elements of the thermal head 28 to be pressed against the platen roller 10 at an appropriate angle.

[0109] 21A and 21B, the thermal head 28 is configured to be able to swing clockwise or counterclockwise around the protrusion 211 as a fulcrum when the printer 1 is viewed from the side, and also to swing clockwise or counterclockwise around the protrusion 211 as a fulcrum when the printer 1 is viewed from above. Therefore, the thermal head 28 can apply uniform pressure to the platen roller 10 during printing. The reason for this is as follows.

[0110] In conventional printers equipped with thermal heads, the thermal head is attached to the printer's internal frame or housing by fixing it at, for example, two points using screws, shafts, brackets, etc. In such cases, misalignment of the attachment position can cause the pressure when the thermal head contacts the platen roller to become uneven in the axial direction of the platen roller, which can result in a deterioration in print quality. In contrast, in this embodiment, when viewed from the side or in a plan view of the printer 1, the thermal head 28 can swing around the convex portion 211 as a fulcrum. Therefore, even if there is an installation error in the platen roller 10, if there is circumferential vibration when the platen roller 10 rotates, or if there are unevenness in the label temporarily attached to the backing paper, the thermal head 28 can follow and maintain uniform pressure on the platen roller 10. Furthermore, since the thermal head 28 can be displaced between positions P1 and P2 (see Figure 18) in the direction in which the coil spring 55 biases the thermal head 28, the thermal head 28 is not hindered from swinging around the convex portion 211 as a fulcrum.

[0111] In addition, some conventional printers equipped with thermal heads have a fulcrum shaft provided below the thermal head and fixed to the printer body, allowing the thermal head to swing in a side view, but unlike printer 1, the thermal head cannot be replaced without tools. In contrast, printer 1 is superior to conventional printers in that the thermal head 28 can be replaced without tools and can swing in a side view and a top view of the printer 1.

[0112] In another embodiment, protrusions 211 may be provided at two locations spaced apart in the left-right direction on the wall surface 21 shown in Fig. 20. Even in this case, the thermal head 28 can be made to swing around the protrusions 211 as a fulcrum when viewed from the side of the printer 1. Even if the thermal head 28 is swingable only when viewed from the side of the printer 1, this can contribute to reducing the deterioration of print quality. In another embodiment, protrusions 211 may be provided at two locations spaced apart in the vertical direction on the wall surface 21 shown in Fig. 20. Even in this case, the thermal head 28 can be made to swing around the protrusions 211 as a fulcrum when viewed from above the printer 1. Even if the thermal head 28 is swingable only when viewed from above the printer 1, this can contribute to reducing the deterioration of 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, when the thermal head 28 is attached to the printer 1, this flexible cable 57 is connected from the connector 285 of the thermal head 28 to a circuit board (not shown) located in the front of the printer 1. At this time, the flexible cable 57 is fixed at a fixing position 24a on the top surface of the bracket 24 located in front of the thermal head 28, for example, by screws or adhesive.

[0114] A cable housing chamber 59 is formed between the thermal head 28 and the circuit board to house the flexible cable 57. A relatively long flexible cable 57 is housed in the cable housing chamber 59 between the connector of the thermal head 28 and the fixing position 24a. Therefore, when the thermal head 28 is removed, the thermal head 28 can be moved to a position sufficiently higher than the printer 1 using the fixing position 24a as a reference, facilitating the work of removing the flexible cable 57 from the connector of the thermal head 28 and replacing it with a new thermal head 28. It is not essential to form the cable accommodating chamber 59. Although the cable length from the connector 285 of the thermal head 28 to the fixing position 24a will be shorter, it is still possible to detach the flexible cable 57 from the connector 285 and replace the thermal head 28.

[0115] 21A and 21B, the cable accommodating chamber 59 is formed in the space sandwiched between the platen holding bracket 27 and the thermal head 28. Therefore, the space formed by the platen holding bracket 27, which is U-shaped in a plan view, can be used efficiently. The cable accommodating chamber 59 does not have to be formed in the 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 the accommodating chamber can be provided in front of the platen holding bracket 27.

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

[0117] In the printer 1 described above, the thermal head 28 is configured to be able to swing clockwise or counterclockwise around the protrusion 211 as a fulcrum when the printer 1 is viewed from the side, and to swing clockwise or counterclockwise around the protrusion 211 as a fulcrum when the printer 1 is viewed from above. This allows the thermal head 28 to apply uniform pressure to the platen roller 10 during printing, preventing a decrease in print quality due to the thermal head installation method.

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

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

[0120] The protruding pieces 72L and 72R protrude from both ends of the base 71 in a direction perpendicular to the main surface of the base 71 (that is, in a direction perpendicular to the surface 281a when attached to the heat sink 281). When the plate-like member 7 is attached to the heat sink 281, the protruding pieces 72L and 72R protrude from the side on which the heat-generating part 284 is mounted, as shown in Fig. 24. The protruding pieces 72L and 72R have tip portions 721L and 721R at their tips. 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 Figures 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. Because a hole is formed in one of the tip portions 721L, 721R and a U-shaped groove is formed in the other, attachment of the plate-like member 7 to the heat sink 281 is easy. When 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 (e.g., connector 285, EEPROM 286, diode 287, etc.) are mounted.

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

[0122] The effect of the thermal head 28A equipped with the plate-like member 7 will be described below 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 in place. In the case of a thermal head 28 that does not include a plate-shaped member 7, when an operator presses the printer cover 3 from above, such as when closing the printer cover 3, the platen roller 10 will be displaced downward from the designed contact position between the platen roller 10 and the thermal head 28. This causes fluctuations in print density. The thermal head 28 is attached to the bearing groove 25 (see FIG. 18) provided in the internal 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 internal frame (see FIG. 5). Therefore, the contact position between the platen roller 10 and the thermal head 28 is easily affected by accumulated errors in assembling the various parts, and is easily displaced from the 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 installed in the printer 1 instead of the thermal head 28, the upper ends of the tip portions 721L and 721R of the plate-shaped member 7 of the thermal head 28A are positioned higher than the edge that forms 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. This makes it difficult for the platen roller 10 to shift downward from the designed position where the platen roller 10 and the thermal head 28 contact each other, even if an operator presses the printer cover 3 from above. This is because the plate-shaped member 7 is integral with the heat sink 281 on which the heat generating portion 284 is mounted. Therefore, even if the platen shaft 10a presses down on the tip portions 721L and 721R, the relative positional relationship between the platen roller 10 and the heat generating portion 284 is unlikely to be affected.

[0125] Referring again to FIG. 25, 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, the protruding plate 73 covers the top of the cable housing chamber 59 formed in front of the thermal head 28A, preventing dust from entering the printer 1 from the outside and preventing dust from adhering to the upper surfaces of the surface-mounted components arranged in front of the thermal head 28A. In other words, the protruding plate 73 functions as a canopy. In particular, as shown in FIG. 2, the roll paper R is replaced with the printer cover 3 in the open position, which makes it easy for dust to enter the printer 1, but even in this case, the surface-mounted components of the thermal head 28A can be protected from dust. From another point of view, providing the protruding plate 73 has the advantage of increasing the strength of the plate-like member 7.

[0126] Although the embodiments of the printer of the present invention have been described above, the present invention is not limited to the above embodiments. Furthermore, various improvements and modifications to the above embodiments are possible without departing from the spirit and scope of the present invention. For example, the individual technical features described in the above embodiments can be combined as appropriate as long as no technical contradictions arise.

[0127] For example, the structure and attachment / detachment method of the thermal heads 28, 28A are not technically related to the structure of the peeling unit 4 or the method of switching the issuance mode, and therefore may be applied to a printer that does not have a peeling unit 4. Conversely, the structure of the peeling unit 4 and the method of switching the issuance mode may be applied to a printer that employs a structure and attachment / detachment method of the thermal heads 28, 28A that are different from those described above.

[0128] Although the case where some of the internal parts of the printer 1 (for example, a shaft, one end of a spring, etc.) are connected to the internal frame has been described, this is not limitative and they may be connected to the main body case 2.

[0129] In the above-described embodiment, a case has been described in which continuous paper with multiple labels temporarily attached to a liner is used as the print medium, but this is not limited to this. When used for continuous printing or in a printer without a peeling unit, for example, continuous labels with an adhesive surface on one side (linerless labels), continuous sheets without an adhesive surface (continuous sheets), or films printable by a thermal head, other than paper, can also be used as the print medium. Furthermore, when conveying linerless labels with exposed adhesive, the conveyance path can be coated with a non-adhesive material, and a non-adhesive roller containing silicone or the like can be provided as the platen roller. [Explanation of symbols]

[0130] 1. Printer 2...Main unit case 21...Wall 211...Convex part 24…Bracket 3. Printer cover 31...Removal unit receiving section 31p...Guide groove 37...Roller pressing mechanism 32...Contact part 33...Coil spring 35...Sensor 4... Peeling unit 41... Peeling roller cover 41a...axis 411...Surface 412...Back side 413...U-shaped groove 415...Engagement hole 42... Peeling roller holding portion 42a…axis 421...Arm 422…Protrusion 43...Coil spring 45...Peeling roller 45a…axis 46...Auxiliary roller 47...Peeling sensor 6a...Paper roll guide 7...Plate-shaped member 71...Base 71a…hole 711...Protrusion 72L,72R…Protruding piece 72a…hole 72b…U-shaped groove 721L,721R…Tip 73...Protruding plate 8...hinge 81...Hinge axis 9...Roll paper storage compartment 10...Platen roller 10a...Platen shaft 10b…Gear 12...Peeling bar 15...Display panel 20…Discharge part 22b...Gear 25...Bearing receiving groove 251…1st 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…Back side 282... Circuit board 283c...Notch 284...heat generating part 285...Connector 29...Coil spring 51...Cover release lever 51a...shaft 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...Engagement protrusion 53, 55... Coil spring 56...Shaft 57...Flexible cable 59...Cable storage room P...Continuous paper PM…Paper PL…Label R...Roll paper

Claims

1. A thermal head including a heat sink, a connector that receives signals from an external circuit board, and a heating unit that has a plurality of heating elements and performs printing by selectively energizing the plurality of heating elements based on signals transmitted from the external circuit board, The heat sink further includes a substrate that covers the heat sink so as to extend from the front surface to the rear surface thereof, the heat generating portion being disposed on the substrate on the front surface side of the heat sink, and the connector being mounted on the substrate on the rear surface side of the heat sink. Thermal head.

2. A thermal head including a heat sink, a connector that receives signals from an external circuit board, and a heating unit that has a plurality of heating elements and performs printing by selectively energizing the plurality of heating elements based on signals transmitted from the external circuit board, The heat sink further includes a substrate that covers the heat sink so as to extend from the front surface of the heat sink through an end portion to the rear surface thereof, the heat generating portion being disposed on the substrate on the front surface side of the heat sink, and the connector being mounted on the substrate on the rear surface side of the heat sink, the connector being located closer to the end portion than the heat generating portion. Thermal head.

Images