Patent ID: 12220927

DETAILED DESCRIPTION

Schematic Structure of Printer1

A printer1according to one embodiment of the present invention is a label printer in which continuous issuing and peeling issuing can be switched. Hereinafter, the printer1will be described in detail with reference to the attached drawings.

It is noted that directions of up (UP), down (DN), left (LH), right (RH), front (FR), and rear (RR) are defined in each drawing, for example, as illustrated in the perspective views ofFIGS.1A and1, but these definitions of directions are made mainly for convenience of explanation of drawings and are not intended to limit an in-use position of the printer of the present invention.

In these definitions of directions, a “printer front-rear direction” means a front-rear direction of the printer1. A “printer width direction” means a right-left direction or a lateral direction of the printer1.

Each ofFIGS.1A,1B, and2is a perspective view of the printer1of this embodiment.FIG.1Ashows a case in which a printer cover3is in a closed state.FIGS.1B and2show cases in which the printer cover3is in an open state.FIG.1Bshows a state in which a paper roll “R” is set.FIG.2illustrates a paper roll “R” and shows a state of the printer1before the paper roll “R” is set.

As shown inFIG.1A, the printer1has a body case2and the printer cover3that protect internal functional components. The printer1has an upper surface provided with an ejection part20for ejecting labels.

It is possible to use the printer1with the ejection part20facing upward (in a horizontally placed state); however, the printer1can also be used with the ejection part20facing a horizontal direction (in a vertically held state), such as by hanging a belt hook (not shown) provided on a bottom of the printer1, on a belt of an operator, or by attaching a shoulder strap (not shown) to the printer1and putting it on a shoulder of an operator.

A display panel15is provided on a front side of the ejection part20in the body case2. The display panel15may have a touch panel input mechanism for receiving an operation input from an operator. The display panel15is connected to a circuit board inside the printer1and outputs an image of a user interface related to, for example, an operating state of the printer1or operation of the printer1, based on a display signal supplied from the circuit board.

Although not shown, an internal frame for supporting or holding various functional components is disposed in the inside of the printer1, which is surrounded by the body case2and the printer cover3. The internal frame, the body case2, and the printer cover3correspond to a printer body.

The printer cover3is able to swing between an open position for exposing the inside of the printer1and a closed position for covering the inside of the printer1.

In response to operation to a cover open button51bthat is provided to the body case2, the printer cover3opens as shown inFIG.1B. Opening the printer cover3exposes a paper roll-containing chamber9. The paper roll-containing chamber9forms space for containing a paper roll “R”.

As shown inFIG.2, the paper roll “R” has a roll shape into which a strip continuous paper “P” is wound. The continuous paper “P” includes a strip liner PM and a plurality of labels PL that are temporarily attached on the liner PM at predetermined intervals. A label adherend surface of the liner PM is coated with a release agent, such as silicone, in order to easily peel off labels PL. In addition, position detection marks “M” that indicate reference positions of labels PL are formed at predetermined intervals on a back surface of the label adherend surface of the liner PM.

A front side of the label PL is a printing surface to be printed with information, and it is formed with a thermal color developing layer that develops a specific color when reaching a predetermined temperature region. A back side of the printing surface is an adhesive surface coated with an adhesive. The adhesive surface is attached to the label adherend surface of the liner PM, whereby the label PL is temporarily attached on the liner PM.

A pair of paper roll guides6aare placed in the paper roll-containing chamber9. The pair of paper roll guides6aare members that rotatably support the paper roll “R” while being in contact with both side surfaces of the paper roll “R” and that guide feeding the continuous paper pulled out of the paper roll “R.” The paper roll guides6aare preferably movable along a width direction of the paper roll “R” in order to vary their positions in accordance with the width of the paper roll “R.”

As shown inFIG.2, the printer cover3is axially supported to the body case2by a hinge8so as to swing relative to the body case2between the open position and the closed position. The hinge8has a hinge shaft81that is provided with a torsion spring (not shown) for biasing the printer cover3in a direction from the closed position to the open position.

As shown inFIG.2, a platen roller10(an example of a feed roller) is axially supported in a manner rotatable in forward and reverse directions, at an end of the printer cover3. The platen roller10is a feeding unit for feeding the continuous paper “P” pulled out of the paper roll “R” and is formed in such a manner as to extend along the width direction of the continuous paper “P.” A gear10bis coupled to an end of a platen shaft10aof the platen roller10. When the printer cover3is at the closed position, the gear10bengages with a gear22bthat is disposed in the body case2, and it is mechanically connected via the gear22bto a roller-driving stepping motor (not shown) or the like.

As shown inFIG.2, a peeling bar12is placed along and in the vicinity of the platen roller10, in the printer cover3. The peeling bar12is a peeling member for peeling labels PL from the liner PM and is fixed to both side walls of the printer cover3at both ends. The peeling bar12may be fixed to both ends of the platen shaft10a.

In an embodiment, the cross section of the peeling bar12has a substantially triangle shape; however, it is not limited thereto, and it may have a spherical shape or an elliptical shape.

The body case2is provided with a platen-holding bracket27for holding the platen shaft10aof the platen roller10when the printer cover3is closed. A thermal head28is disposed in front of the platen-holding bracket27.

The thermal head28is a print unit for printing information such as characters, symbols, figures, or bar codes, on labels PL, which are temporarily attached on the liner PM fed out of the paper roll “R.” The thermal head28is provided so as to face the platen roller10when the printer cover3is in the closed state.

As described later, a flexible cable that is connected to the circuit board (not shown) is detachably attached to the thermal head28. The thermal head28includes a plurality of heating elements (heating resistors) that are arranged along the width direction of the continuous paper “P.” The thermal head28performs printing by selectively energizing the plurality of heating elements based on a signal transmitted from the circuit board.

As shown inFIG.2, coil springs55are disposed in front of the thermal head28. The coil spring55is in contact with the thermal head28at a rear end and is also in contact with the internal frame at a front end (also refer toFIG.19). The coil spring55biases the thermal head28to the platen roller10in printing, whereby the thermal head28is pressed against the platen roller10by an optimum pressure for printing.

The printer1includes a peeling unit4and performs continuous issuing and peeling issuing in accordance with the peeling unit4moved between a continuous issuing position and a peeling issuing position. As shown inFIG.1B, a peeling unit open button52bis exposed when the printer cover3is at the open position. The peeling unit4is moved by operating the peeling unit open button52b.FIG.2shows a state of the peeling unit4when the peeling unit open button52bis operated.

As described later, the peeling unit open button52bis operated by an operator, in order to switch from continuous issuing to peeling issuing.

As shown inFIG.2, the peeling unit4includes a peeling roller cover41and a peeling roller holder42that holds a peeling roller45. The peeling roller cover41covers the peeling roller holder42in continuous issuing. The peeling roller cover41is axially supported by the internal frame in the body case2and swings from a closed position to an open position (state shown inFIG.2) in accordance with operation to the peeling unit open button52b.

The peeling roller holder42is axially supported by the peeling roller cover41. In continuous issuing, the peeling roller holder42is contained in such a manner as to be folded under a back surface of the peeling roller cover41.

The peeling unit4will be detailed later.

The printer cover3is provided with a sensor35. The sensor35is disposed in a feeding path of the continuous paper “P”, along which the continuous paper “P” pulled out of the paper roll “R” reaches the platen roller10. The sensor35detects positions of labels PL, when the printer cover3is in the closed state. It is preferable to control a feeding amount of the continuous paper “P” based on results detected by the sensor35.

Although not shown, it is preferable to provide a cutter for cutting the liner PM of the continuous paper “P” that has been continuously issued. In the case of providing a cutter, the cutter is placed at the ejection part20so as to extend along the width direction of the continuous paper “P.” Alternatively, the function of the cutter may be imparted to the peeling bar12.

Continuous Issuing and Peeling Issuing

Next, continuous issuing and peeling issuing of the printer1will be described with reference toFIG.3.

The printer1is configured to allow switching between peeling issuing and continuous issuing. Peeling issuing is issuing labels after peeling them from a liner of a continuous paper, while continuous issuing is issuing labels without peeling them from the liner.

For continuous issuing, a liner that is attached with a necessary amount of labels is prepared, and the labels can be affixed by peeling them from the liner in a working site. Thus, continuous issuing is appropriate for a situation that a target on which a label is to be affixed is distant from the printer1. In order to perform continuous issuing, the peeling unit4, which is mounted to the printer1, is set to the continuous issuing position.

On the other hand, in the case of peeling issuing, labels are ejected one by one in a state of being peeled from a liner. Thus, peeling issuing is appropriate for a situation that a target on which a label is to be affixed is close to an operator. In order to perform peeling issuing, the peeling unit4, which is mounted to the printer1, is set to the peeling issuing position. In this state, as a continuous paper is fed by rotating the platen roller10in order to perform printing, while a liner is fed in a state of being nipped between the peeling roller45and the platen roller10, printed labels are individually peeled from the liner and are then ejected to the outside of the printer1.

FIG.3shows schematic partial sectional views showing positional relationships between the peeling unit4, the platen roller10, the peeling bar12, and the thermal head28in continuous issuing and in peeling issuing. The peeling roller cover41and the peeling roller holder42of the peeling unit4are represented only by outlines inFIG.3. The outline of the peeling roller cover41is shown by a dotted line.

In addition, the position of the peeling roller holder42differs between continuous issuing and peeling issuing, and therefore, only the peeling roller holder42is shown by hatching.

The position of the peeling unit4in continuous issuing corresponds to the continuous issuing position, whereas the position of the peeling unit4in peeling issuing corresponds to the peeling issuing position.

As shown inFIG.3, in continuous issuing, the peeling roller holder42is contained under the peeling roller cover41, and the peeling roller45is thereby at a position spaced apart the platen roller10and thus does not interrupt ejection of the continuous paper “P.” The continuous paper “P” that has been pulled out of the paper roll “R” is nipped between the platen roller10and the thermal head28, and labels on the continuous paper “P” are printed.

In order to switch from continuous issuing to peeling issuing, the peeling roller holder42is swung around a shaft42ato a position shown inFIG.3. As shown inFIG.3, in peeling issuing, the peeling roller45is disposed at a position facing the platen roller10. Also, in peeling issuing, the continuous paper “P” that has been pulled out of the paper roll “R” is nipped between the platen roller10and the thermal head28, and labels on the continuous paper “P” are printed. This movement is the same as in continuous issuing. In peeling issuing, the liner PM of the continuous paper “P” that has been pulled out of the paper roll “R” is quickly turned by the peeling bar12and is nipped between the platen roller10and the peeling roller45to be ejected. In accordance with quick turning of the liner PM at the peeling bar12, a label PL is peeled from the liner PM and ejected.

Opening Movement of Printer Cover3

Next, opening movement of the printer cover3will be described with reference toFIGS.4and5. In addition, a cover open lever51and a peeling unit open lever52will also be described.

FIG.4shows side views of the cover open lever51, the peeling unit open lever52, the platen-holding bracket27, and the peeling unit4when the printer cover is closed and when the cover open button is operated.FIG.4shows an exemplary situation in which the peeling unit4is at the continuous issuing position.

As shown inFIG.4, in a side view, the cover open lever51and the peeling unit open lever52are disposed to face in the front-rear direction, while extending in the front-rear direction at mutually different heights, resulting in space-efficient arrangement.

FIG.5is a perspective rear view of the cover open lever51, the peeling unit open lever52, the platen-holding bracket27, and the peeling unit4when the printer cover is closed.FIG.5omits illustration of the peeling unit4.

The cover open lever51has the cover open button51bthat is exposed to the outside, as shown inFIG.1A. The cover open lever51is formed with a shaft insertion hole51a, and a shaft part56(not shown inFIG.5) that is provided to the internal frame is inserted in the shaft insertion hole51a. This makes the cover open lever51be able to swing around the shaft part56. As shown inFIG.5, the cover open lever51has a protrusion51cthat protrudes inward.

As shown inFIG.5, the platen-holding bracket27has a shaft27a. One end of the shaft27ais inserted in a boss52athat is provided to the peeling unit open lever52, whereas the other end of the shaft27ais inserted in a boss that is provided to the internal frame (not shown). This makes the platen-holding bracket27be able to swing around the shaft27a.

In addition, the peeling unit open lever52has an engaging protrusion523(refer toFIG.4) that protrudes inward, although the engaging protrusion523is not seen inFIG.5. As described later, the engaging protrusion523engages with the peeling roller cover41of the peeling unit4.

The platen-holding bracket27has a hole27cthat is formed in a side wall, and the protrusion51cof the cover open lever51is inserted in the hole27c. Herein, the hole27cis formed greater than the protrusion51cin a side view (that is, the hole27chas play), whereby the platen-holding bracket27is able to swing. The platen-holding bracket27swings around the shaft27a, whereas the cover open lever51swings around the shaft part56(refer toFIG.4), and therefore, they have different swing axes. In consideration of this, the hole27cis provided with play so as to absorb the difference in trajectory between the hole27cand the protrusion51cdue to the different swing axes.

The peeling unit open lever52is able to turn (or swing) around the shaft27a, which is inserted in the boss52a. That is, the platen-holding bracket27and the peeling unit open lever52share the single swing shaft27a, which eliminates a need to provide another swing shaft for the peeling unit open lever52, resulting in contribution to reduction in space and cost. Nevertheless, the structure is not limited thereto, and in another embodiment, an individual swing shaft may be set to each of the platen-holding bracket27and the peeling unit open lever52.

A coil spring53is interposed between the peeling unit open lever52and the internal frame (not shown), at a position immediately below the peeling unit open button52b. Upon being pressed (operated) down against a restoring force of the coil spring53, the peeling unit open lever52swings around the shaft27a(swings in a clockwise direction inFIG.4). As described later, in accordance with swinging of the peeling unit open lever52, the peeling unit4swings via the engaging protrusion523and moves from the closed position to the open position.

When the force for pressing down the peeling unit open button52bis released, the peeling unit open lever52returns (swings) to the position where it is disposed before being pressed down, by the restoring force of the coil spring53.

The platen-holding bracket27is biased by a pair of coil springs29. InFIG.5, one end of each of the coil springs29is hooked to the platen-holding bracket27, whereas the other end of each of the coil springs29is hooked to the internal frame (not shown).

Unless an external force is applied to the platen-holding bracket27, the platen-holding bracket27is in the position at the time the printer cover is closed, as shown inFIG.4, and it holds the platen shaft10ain a groove27b. This position is a locking position for locking the printer cover3coupled to the platen shaft10a, at the closed position.

In this state, in response to the cover open button51bbeing pressed (operated) down, the cover open lever51swings around the shaft part56(swings in a counterclockwise direction inFIG.4). In accordance with swinging of the cover open lever51, the protrusion51cpresses a rim of the hole27cof the platen-holding bracket27to swing the platen-holding bracket27around the shaft27a(in the clockwise direction inFIG.4) against the restoring force of the coil spring29. As described above, the printer cover3, which is mounted with the platen shaft10a, is biased in the direction from the closed position to the open position. Thus, the printer cover3moves to the open position when the platen shaft10acomes off from the groove27bdue to swinging of the platen-holding bracket27. The position of the platen-holding bracket27at this time is an unlocking position for unlocking the printer cover3at the closed position.

Conversely, in closing the printer cover3, a pressing down force of an operator closing the printer cover3makes the platen shaft10a, which is mounted to the printer cover3, press down an inclined top part of the platen-holding bracket27against the restoring force of the coil spring29. In response to this, the platen-holding bracket27is swung in the clockwise direction inFIG.4, and the platen shaft10ais inserted in the groove27bof the platen-holding bracket27. In the state in which the platen shaft10ais inserted in the groove27b, the platen-holding bracket27returns to the locking position at the time the printer cover is closed, as shown inFIG.4, by the restoring force of the coil spring29.

Peeling Unit4

Next, the peeling unit4will be described with reference toFIGS.6to9.

FIG.6shows perspective views of the peeling unit4when open and when closed. The peeling unit4when closed, which is shown inFIG.6, is at the continuous issuing position.

The open position of the peeling unit4is a position when the peeling roller cover41is opened in accordance with operation to the peeling unit open button52b. That is, the open position of the peeling unit4corresponds to the open position of the peeling roller cover41.

The open position of the peeling roller cover41is a position for exposing at least a part of the inside of the printer1or at least a part of the inside of the body case2, as shown inFIG.2. In one example, as shown inFIG.2, when the peeling roller cover41is at the open position, the coil springs55, a flexible cable57(refer toFIG.21) connected to the thermal head28, and so on, inside the body case2, are exposed. From another point of view, the open position of the peeling roller cover41may be defined as a position for exposing the thermal head28inside the body case2. From yet another point of view, the open position of the peeling roller cover41may be also defined as a position for allowing opening the peeling roller cover41at the corresponding position when the peeling roller holder42is at a position facing the back surface of the peeling roller cover41. As shown inFIG.6, when the peeling roller cover41is at the open position (is open), the peeling roller holder42protrudes upward (in a protruding state).

The closed position of the peeling unit4is a position when the peeling roller cover41is closed. That is, the closed position of the peeling unit4corresponds to the closed position of the peeling roller cover41.

The closed position of the peeling roller cover41is a position for covering at least a part of the inside of the printer1or at least a part of the inside of the body case2, which is exposed when the peeling roller cover41is at the open position. In one example, as shown inFIGS.1A and1, when the peeling roller cover41is at the closed position, the coil springs55, the flexible cable57, and so on, are not visible from the outside and are covered. From another point of view, the closed position of the peeling roller cover41may be defined as a position for covering at least a part of the thermal head28inside the body case2. From yet another point of view, the closed position of the peeling roller cover41may be also defined as a position for retaining the peeling roller cover41at the corresponding position instead of opening it, when the peeling roller holder42is at the position facing the back surface of the peeling roller cover41. When the peeling roller cover41is at the closed position, the position of the peeling roller holder42differs between for continuous issuing and for peeling issuing.

As shown inFIG.6, when the peeling roller cover41is at the closed position in continuous issuing, the peeling roller holder42is contained under the peeling roller cover41(in a contained state).

With reference toFIG.6, the peeling roller cover41is a swing member that has a pair of shafts41aand is thereby able to swing around the shafts41a. The shaft41ahas a circular cross section and is inserted in a tubular part (not shown), which is provided to the internal frame, so as to be rotatable. The tubular part is preferably formed with, for example, an elongated hole in the printer front-rear direction so that the shaft41acan be slightly displaced in the printer front-rear direction thereinside. The elongated hole provides play in the printer front-rear direction to the shaft41athat is inserted in the tubular part, and it improves resistance to impact of falling, etc., of the printer1.

The direction of the elongated hole that is formed in the tubular part is not limited to the printer front-rear direction, and for example, it can be set to any direction such as the upper-lower direction of the printer1, in a plane perpendicular to the right-left direction of the printer1.

The peeling roller cover41extends in the same direction as the extending direction of the platen roller10. The peeling roller cover41has a surface411and a back surface412. The surface411is a surface that is exposed when the peeling roller cover41is at the closed position. The back surface412is formed with a recess so as to contain the peeling roller holder42. Conversely, the surface411has a swollen shape at the center in the front-rear direction, which is convenient to cut a liner when a cutter is provided to the ejection part20.

The peeling roller cover41is formed with an engaging hole415in the vicinity of the shaft41a. As described later, the engaging protrusion523of the peeling unit open lever52is inserted in the engaging hole415.

The peeling roller cover41may be provided at the side with a pair of U-shaped grooves413. The U-shaped groove413abuts on a protrusion26(refer toFIG.18) that is formed to the internal frame, when the shaft41ais at the closed position. The U-shaped groove413functions as a part for positioning in the upper-lower direction of the peeling unit4by abutting on the protrusion26. The U-shaped groove413in the state of abutting on the protrusion26provides a predetermined gap between the peeling unit4and the thermal head28. Thus, it is possible to reliably prevent interference between the peeling unit4and the thermal head28.

As described above, the shaft41aof the peeling unit4is preferably inserted in the elongated hole in the printer front-rear direction, which is formed in the tubular part of the internal frame, whereby play is provided in the printer front-rear direction. Under these conditions, the U-shaped groove413in the state of abutting and being engaged with the protrusion26(refer toFIG.18) prevents positional deviation in the printer front-rear direction of the peeling unit4(peeling roller cover41) due to play of the shaft41ainserted in the elongated hole (that is, functions as a part for positioning in the printer front-rear direction of the peeling unit4).

However, the U-shaped groove413and the protrusion26are not necessarily provided. The abutting parts of a part of the peeling unit4and the internal frame can be formed into any shape as appropriate, in the condition in which they can abut on each other while ensuring the gap between the peeling unit4and the thermal head28. Instead of such an abutting structure, the position in the upper-lower direction of the peeling unit4can be determined by, for example, limiting the movable range of the shaft41aof the peeling roller cover41.

The surface411of the peeling roller cover41is disposed with a peeling sensor47. The peeling sensor47is an optical reflective sensor that detects presence or absence of a label peeled in peeling issuing. With reference toFIG.3, a label PL that is peeled by the peeling bar12is controlled so that its part on a feeding direction upstream side will be fed and stop in the vicinity of the peeling bar12, and the peeled label PL thereby remains at the peeling bar12by its adhesive strength. The peeling sensor47detects presence or absence of this label PL. When the peeled label is picked up by an operator, the peeling sensor47detects absence of the label PL, and control is performed to issue a next label.

With reference toFIG.6, the peeling roller holder42is a member that holds the peeling roller45.

The peeling roller holder42extends in the same direction as the extending direction of the platen roller10, as in the case of the peeling roller cover41. The peeling roller holder42is configured to be contained under the back surface412of the peeling roller cover41. For this purpose, a pair of shafts42aare disposed inward of the pair of shafts41aof the peeling roller cover41, and the width of the peeling roller holder42is made smaller than that of the peeling roller cover41.

The peeling roller holder42is a swing member that has the pair of shafts42aand is thereby able to swing around the shafts42a. The pair of shafts42aare axially supported by the peeling roller cover41, at positions separated from the shafts41a. The peeling roller45is disposed to distal ends of arms421extending from the shafts42a. Thus, as shown inFIG.6, the peeling roller45largely protrudes upward based on the shafts41a, when the peeling unit4is open.

That is, the peeling roller holder42is able to swing between a contained position when the peeling roller45is contained under the peeling roller cover41, and a protruding position when the peeling roller45is not covered with the peeling roller cover41. The protruding position is a position when the peeling roller cover41is open, as shown inFIG.6. The contained position of the peeling roller holder42is also a position for facing the back surface412of the peeling roller cover41as well as a position for being covered with the peeling roller cover41.

In order to contain the peeling roller holder42, the peeling roller holder42is swung around the shaft42ato the back surface412of the peeling roller cover41, and moreover, the whole peeling roller cover41and peeling roller holder42are swung around the shaft41a. As a result, the peeling roller holder42is compactly contained under the peeling roller cover41in such a manner as to be folded down.

On the other hand, when the peeling roller cover41is at the open position, the peeling roller holder42is able to swing between the contained position and the protruding position. As described later, the peeling roller holder42is biased in a direction from the contained position to the protruding position by a coil spring43. Thus, immediately after the peeling roller cover41moves from the closed position to the open position, the peeling roller holder42moves in such a manner as to spring out from the contained position to the protruding position. This structure enables an operator to quickly switch from continuous issuing to peeling issuing.

When the peeling roller holder42is at the protruding position, the peeling roller45is highly protruded. This enables moving the peeling roller45to a distant position in setting the peeling unit4to the peeling issuing position.

A pair of arms421extend from the pair of shafts42a. A shaft45afor rotating the peeling roller45and auxiliary rollers46is disposed at the distal ends of the pair of arms421. Each of the auxiliary rollers46has a diameter smaller than that of the peeling roller45. Providing the auxiliary rollers46on both sides of the peeling roller45enables smoothly ejecting a wide liner in peeling issuing of a wide label. If the auxiliary rollers46were not provided, a wide liner would be able to move in the width direction (right-left direction); but providing the auxiliary rollers46enables stably feeding a wide liner.

However, the auxiliary rollers46are not necessarily provided. In the case of not using the auxiliary rollers46, peeling issuing can be executed in the condition in which the peeling roller45is provided.

Each of the arms421is formed with a protrusion422that protrudes outward. As described later, the protrusion422is provided so as to engage the peeling unit4with the printer cover3in peeling issuing.

As shown inFIG.6, a pair of coil springs43are provided in the vicinity of the pair of shafts42aof the peeling roller holder42. Although not shown, the coil spring43is coupled to the peeling roller holder42at one end and is also coupled to the peeling roller cover41at the other end, and it thereby biases the peeling roller holder42in the direction for swinging from the contained position to the protruding position. With this structure, when the peeling roller cover41is at the open position (that is, the peeling unit4is at the open position), the peeling roller holder42is at the protruding position at any time.

FIG.7is a perspective view of the peeling unit4when open, as seen from a viewpoint different from that ofFIG.6. In the state in which the peeling roller holder42is at the protruding position, the arms421of the peeling roller holder42partially abut on the surface411of the peeling roller cover41. In other words, the surface411of the peeling roller cover41functions as a stopper for the peeling roller holder42that is swung by the coil spring43.

Next, movements in making the peeling unit4be at the open position from the state in continuous issuing, will be described with reference toFIGS.8and9.

FIGS.8and9sequentially show side views of the peeling unit open lever52and the peeling unit4, from states S1to S3.

The state S1shows a state in which the printer cover3is open in continuous issuing. The state S2shows a state of continuously operating the peeling unit open button. The state S3shows a state of releasing operation of the peeling unit open button.

The peeling unit open lever52and the peeling unit4are engaged with each other by inserting the engaging protrusion523of the peeling unit open lever52in an engaging hole415of the peeling roller cover41, from the inside. The peeling unit open lever52swings so as to move the peeling roller cover41between the closed position and the open position.

The engaging hole415has, for example, a heart shape, and it allows the engaging protrusion523to move therein.

As shown by the state S1inFIG.8, when the printer cover3is open in continuous issuing, the engaging protrusion523is positioned on a lower side in the engaging hole415. In this state, the peeling roller holder42is at the contained position under the back surface412(refer toFIG.6) of the peeling roller cover41.

When the peeling unit open button52bis pressed (operated) down, the peeling unit open lever52swings around the shaft27ain a clockwise direction inFIG.8. In response to this, the engaging protrusion523of the peeling unit open lever52moves upward in the engaging hole415and upwardly presses the peeling roller cover41, at an upper rim of the engaging hole415. The peeling roller cover41is thereby swung around the shaft41ato the open position in a counterclockwise direction inFIG.8. As described above, the peeling roller holder42is biased in the direction for swinging from the contained position to the protruding position, by the coil spring43(refer toFIG.6). Thus, as the peeling roller cover41swings to the open position, a position restriction of the peeling roller holder42due to a second stopper522is released to form space in which the peeling roller holder42is able to swing. As a result, the peeling roller holder42swings to the protruding position, as shown by the state S2inFIG.8. The second stopper522will be described later.

As shown by the state S2inFIG.8, the position of the shaft42ais higher when the peeling roller cover41is at the open position than when the peeling roller cover41is at the closed position. In addition, as described above, in the printer1, space is formed in which the peeling roller holder42is able to swing from the contained position to the protruding position, when the peeling roller cover41is at the open position. Thus, the peeling roller holder42springs up by the biasing force of the coil spring43.

When pressing down of the peeling unit open button52bis released from the state shown by the state S2, the peeling unit open lever52swings around the shaft27ain the counterclockwise direction inFIG.8, with the restoring force of the coil spring53. The peeling unit open lever52and the peeling roller cover41thereby return to the positions in the state S1. Meanwhile, the peeling roller holder42, which swings to the protruding position once, remains at the protruding position, instead of returning to the contained position. As a result, the peeling unit4is in the condition shown by the state S3inFIG.9.

Engagement Between Peeling Unit4and Printer Cover3

In the printer1, the peeling unit4is set to the peeling issuing position while the printer cover3and the peeling unit4are engaged with each other, by swinging the printer cover3from the open position to the closed position in the state S3inFIG.9.

Hereinafter, engagement between the peeling unit4and the printer cover3in peeling issuing will be described with reference toFIGS.10A,10B, and11.

First, the structure of the printer cover3for engaging with the peeling unit4will be described with reference toFIGS.10A and10B.FIG.10Ais a plane view of the printer cover3, andFIG.10Bis an enlarged view of an A-A cross section inFIG.10A.

As shown inFIG.10A, the printer cover3has a pair of peeling unit-receiving parts31at front ends. The peeling unit-receiving part31is provided in the vicinity of the position at which the platen roller10and the peeling bar12are supported.

As shown inFIG.10B, the peeling unit-receiving part31is formed with a guide groove31pthat opens forward. The guide groove31pis a groove that opens only to the inside along a direction from the front end to a rear end of the printer cover3. The guide groove31preceives the protrusion422(refer toFIG.9) of the peeling unit4that is positioned on a front side, in the process of closing the printer cover3.

A roller-pressing mechanism37is provided in the guide groove31p. As described later, the roller-pressing mechanism37presses the peeling roller45to the platen roller10to generate a nip pressure for nipping a liner between the peeling roller45and the platen roller10, when the printer cover3is at the closed position.

The roller-pressing mechanism37includes an abutting part32that is disposed in the guide groove31pand also includes a coil spring33that is disposed behind the abutting part32. In accordance with the printer cover3being moved to the closed position, the protrusion422of the peeling unit4is guided to the abutting part32.

When operation to move the printer cover3from the open position to the closed position is performed in the state S3inFIG.9, the protrusion422of the peeling unit4enters the guide groove31pof the peeling unit-receiving part31during the process of moving the printer cover3. As the printer cover3swings to the closed position, the protrusion422advances toward the rear of the printer cover3along the guide groove31pand abuts on the abutting part32. In this manner, the printer cover3engages with the peeling unit4. When the printer cover3reaches the closed position, the peeling roller45of the peeling unit4engaging with the printer cover3is at a position facing the platen roller10.

Thus, it is possible for an operator to engage the printer cover3with the peeling unit4while moving the peeling unit4to the peeling issuing position, only by operation to close the printer cover3.

FIG.11is an enlarged sectional view showing a part in the vicinity of the platen roller10when the printer cover3is completely closed and the peeling unit4is set to the peeling issuing position.

As shown inFIG.11, when the printer cover3is at the closed position, the peeling roller45of the peeling unit4is disposed at a position facing the platen roller10. In this state, the protrusion422of the peeling unit4abuts on the abutting part32of the peeling unit-receiving part31of the printer cover3to compress the coil spring33behind the abutting part32. A restoring force of the coil spring33acts on the peeling roller45via the protrusion422and thereby makes the peeling roller45press the platen roller10, resulting in generation of a nip pressure for nipping a liner. With this structure, a force in a rotation direction around the shaft42aof the peeling roller holder42(F5cinFIG.11) is converted into a nip pressure between the peeling roller45and the platen roller10.

In an embodiment, a normal line direction of an abutting surface of the abutting part32abutted with the protrusion422(direction denoted by a reference symbol “F5b”), and a direction from the center of the peeling roller45to the center of the platen roller10, may be the same in a side view, as shown inFIG.11. However, the direction of the force F5varies depending on the abutting angle between the protrusion422and the abutting part32, and therefore, these directions may not be the same. As shown inFIG.11, a component force F5bbeing a normal component with respect to the abutting surface, of a reaction force F5of the abutting part32acting on the protrusion422, causes the peeling roller45to press the platen roller10, whereby a nip pressure for nipping a liner is more effectively generated.

Movement for Containing Peeling Roller Holder42

Next, movement for moving the peeling roller holder42at the protruding position to contain it under the peeling roller cover41and setting the peeling unit4to the continuous issuing position, will be described with reference toFIGS.12and13.

In order to switch from peeling issuing to continuous issuing, the cover open button51bis pressed down to open the printer cover3, and the peeling unit open button52bis then pressed down. In response to this, as shown by the state S2inFIG.8, the peeling roller cover41swings to the open position, and the peeling roller holder42swings to the protruding position. In this state, operation to fold down the peeling roller holder42to contain it under the peeling roller cover41(folding operation) is performed by an operator, whereby the peeling unit4is set to the continuous issuing position.

FIGS.12and13sequentially show perspective views of the peeling unit open lever52and the peeling unit4when an operator performs the folding operation of the peeling unit4, from states S5to S9.

As shown inFIG.12, the peeling unit open lever52has a first stopper521and a second stopper522that protrude inward. The first stopper521and the second stopper522are disposed separately in the front-rear direction and are provided so as to abut on the arm421of the peeling roller holder42and thereby restrict swinging of the arm421.

The state S5inFIG.12is a state in which the peeling roller cover41is at the open position and the peeling roller holder42is at the protruding position, which corresponds to the state S2inFIG.8. An operator can maintain this state by continuously pressing down the peeling unit open button52b.

In the state S5, an operator may rotate (or swing) the peeling roller holder42around the shaft42aand move it to the contained position under the back surface412of the peeling roller cover41. Thus, the state is changed to the state S6. At this time, a part most distant from the shaft42aof the arm421crosses over the first stopper521by the operating force of the operator. This makes the arm421abut on the first stopper521to restrict swinging of the peeling roller holder42, against the restoring force of the coil spring43(refer toFIG.6). That is, when the peeling roller holder42is in the contained position and the peeling roller cover41is at the open position, the first stopper521abuts on the arm421to restrict swinging of the peeling roller holder42. In the state in which the first stopper521restricts swinging of the peeling roller holder42, it is easy to move the peeling roller cover41to the closed position while retaining the peeling roller holder42at the contained position. If the first stopper521were not provided, an operator would need to move the peeling roller cover41to the closed position by releasing pressing down the peeling unit open button52bwhile holding the peeling roller holder42by hand so as to prevent it from swinging from the contained position. Thus, providing the first stopper521improves operability.

When the operator releases pressing down the peeling unit open button52bin the state in which the peeling roller holder42is locked at the contained position by the first stopper521, the peeling roller cover41starts moving to the closed position. The state S7shows a state while the peeling roller cover41is moving to the closed position.

In the process in which the peeling roller cover41moves to the closed position, restriction of swinging of the arm421by the first stopper521is released in accordance with swinging of the peeling roller cover41. Specifically, an outer edge of the arm421is formed so that restriction of swinging of the arm421will be released at the time the peeling roller cover41is closed to a predetermined angle.

The state S8inFIG.13is a state at the time the operator further closes the peeling roller cover41from the state S7. The peeling roller holder42, in which restriction of swinging by the first stopper521is released, is swung by the restoring force of the coil spring43, but it is again restricted from swinging by the second stopper522, which is on a rear side of the first stopper521. That is, the second stopper522comes into contact with the arm421while the peeling roller holder42moves from the open position to the closed position, whereby it restricts the peeling roller holder42from swinging between the contained position and the protruding position. The state S9is a state in which the peeling roller cover41is at the closed position and the peeling unit4is at the continuous issuing position.

Providing the second stopper522prevents the peeling roller holder42from swinging while the peeling roller cover41moves from the open position to the closed position. Moreover, the second stopper522is positioned rearward of the first stopper521, and thus, when the peeling unit open button52bis operated in the state in which the peeling unit4is at the continuous issuing position as shown by the state S9, the peeling roller holder42smoothly swings to the protruding position.

The first stopper521and the second stopper522are not necessarily provided. Providing even only one of the stoppers can contribute to improving operability. It is also possible to perform the folding operation of the peeling unit4, even when both of the first stopper521and the second stopper522are not provided. Specifically, it is possible for an operator to contain the peeling roller holder42under the peeling roller cover41by carefully moving the peeling roller cover41to the closed position while holding the peeling roller holder42at the contained position by hand.

Movement to Switch Between Continuous Issuing and Peeling Issuing of Printer1

Next, movement to switch between continuous issuing and peeling issuing of the printer1will be described with reference toFIGS.14and15.

FIGS.14and15sequentially show side views of a main part of the printer1at the time of switching from continuous issuing to peeling issuing, from states S10to S15.FIG.15omits illustration of the platen-holding bracket27.

The state S10inFIG.14shows a state of the printer1in continuous issuing. In this state, the platen shaft10aof the platen roller10, which is axially supported by the printer cover3, is fitted in the groove27bof the platen-holding bracket27, whereby the printer cover3is held. In the state S10, the peeling unit4is set to the continuous issuing position.

When an operator presses down the cover open button51bin the state S10, holding of the platen shaft10aby the platen-holding bracket27is released. Then, as shown by the state S11, the printer cover3is moved to the open position by the biasing force of the torsion spring provided to the hinge8(refer toFIG.2).

Subsequently, when the operator presses down the peeling unit open button52b, the peeling roller cover41swings from the closed position to the open position, and the peeling roller holder42swings from the contained position to the protruding position, as shown by the state S12. Then, when the operator releases pressing down of the peeling unit open button52b, the peeling roller cover41returns to the closed position, but the peeling roller holder42remains at the protruding position with the biasing force of the coil spring43(refer toFIG.6), as shown by the state S13inFIG.15.

Next, in accordance with the printer cover3being closed by the operator, the protrusion422of the peeling roller holder42at the protruding position is inserted in the guide groove31p(refer toFIG.10B) of the printer cover3and is guided therealong, whereby the printer cover3and the peeling unit4engage with each other, as shown by the state S14.

As shown by the state S15, when the printer cover3reaches the closed position, the platen shaft10aof the platen roller10is held by the platen-holding bracket27, and the peeling unit4is set to the peeling issuing position. That is, the peeling roller45of the peeling unit4is disposed at the position facing the platen roller10to nip the liner PM with the platen roller10. In this state, as described above, the protrusion422that is engaged with the printer cover3is pressed by the coil spring33(refer toFIG.11), whereby an appropriate nip pressure against the platen roller10is generated in the peeling roller45.

In peeling issuing, a label PL that is printed by the thermal head28is peeled from the liner PM, due to the liner PM being quickly turned by the peeling bar12. The peeling roller45is driven to rotate in accordance with rotation of the platen roller10and ejects the liner PM.

In order to switch from peeling issuing to continuous issuing, the cover open button51bis pressed down to open the printer cover3, and the peeling unit open button52bis then pressed down. This causes the peeling roller cover41of the peeling unit4to swing to the open position and also causes the peeling roller holder42to swing to the protruding position. Thereafter, as described with reference toFIGS.12and13, the folding operation of the peeling unit4is performed to set the peeling unit4to the continuous issuing position.

As described above, the printer1of the embodiment includes the peeling unit4that is movable between the continuous issuing position and the peeling issuing position. When the peeling unit4is at the continuous issuing position, the peeling roller holder42holding the peeling roller45is compactly contained at the contained position under the back surface of the peeling roller cover41.

Switching from continuous issuing to peeling issuing is performed by a simple operation as follows: opening the printer cover3; operating the peeling unit open button52bto move the peeling roller holder42to the protruding position; and closing the printer cover3. That is, switching can be performed by a simple action of these easy three steps, and operability is excellent. In addition, when the printer cover3is at the closed position, the peeling roller45is pressed against the platen roller10by the roller-pressing mechanism37of the printer cover3, resulting in generation of an appropriate nip pressure.

Conversely, switching from peeling issuing to continuous issuing is performed as follows: opening the printer cover3; operating the peeling unit open button52bto move the peeling roller holder42to the protruding position; performing the folding operation to move the peeling roller holder42to the contained position; and closing the printer cover3. Also in this case, the operation is simple.

Method of Mounting and removing Thermal Head28

Next, a method of mounting and removing the thermal head28to and from the printer1will be described with reference toFIGS.16A to19.

FIG.16Ashows a front side biased by the coil spring55, which is one of both surfaces of the thermal head28, andFIG.16Bshows a rear side of the thermal head28. The rear side of the thermal head28faces the platen roller10.FIG.17shows enlarged sectional views of an A-A cross section and a B-B cross section inFIG.16A.

As shown inFIGS.16A and17, the thermal head28has a structure in which a board282is attached to a heat dissipation plate281that has a substantially rectangular shape in a plane view. The heat dissipation plate281is made of a metal material having a high thermal conductivity, such as aluminum. The A-A cross section inFIG.17shows that the board282is attached to the heat dissipation plate281in such a manner as to extend from a surface281aof the heat dissipation plate281to a back surface281bon a side opposite to the surface281a, via a first end part281e1interposed therebetween. The board282is, for example, a ceramic board.

The surface281a, which faces a rear side of the printer1, is an example of a first surface. The back surface281b, which faces a front side of the printer1, is an example of a second surface. As shown inFIG.16Band by the B-B cross section inFIG.17, a cutout283c(an example of an opening part) is provided at a substantially center position in a longitudinal direction (lateral direction) of the surface281aof the thermal head28. The cutout283cdoes not have the board282and exposes the surface281aof the heat dissipation plate281. As described later, the cutout283cis configured to be in contact with a protrusion211(refer toFIG.20) for allowing the thermal head28to swing.

As shown inFIG.16Aand by the A-A cross section inFIG.17, the board282that is attached to the back surface281bof the heat dissipation plate281is mounted with, but not limited to, surface-mount devices (SMDs) such as a connector285, an EEPROM286(an example of a memory chip), and a diode287. In the state in which the thermal head28is mounted to the printer1, the flexible cable57is connected to the connector285. The flexible cable57transmits a signal from the circuit board (not shown) of the printer1to the thermal head28.

In the state in which the thermal head28is mounted to the printer1, the relatively tall surface-mount devices (e.g., the connector285, the EEPROM286, and the diode287inFIG.16A), which are mounted on the back surface281bof the heat dissipation plate281, face the front side of the printer1. This configuration protects these surface-mount devices from water, etc., which may enter from the ejection part20on a rear side of the thermal head28. A driver IC (not shown) is mounted in the vicinity of a heat generating part284on the rear side of the thermal head28facing the ejection part20(on a side on which the surface281aof the heat dissipation plate281is provided). Due to the driver IC with low height, the driver IC and wiring are protected together with the heat generating part284by a protective layer or a coating layer, whereby they are unlikely to be damaged by water entering from the ejection part20.

As shown inFIG.16B, the tall surface-mount devices, such as the connector, are not disposed on the rear side of the thermal head28(on the side disposed with the heat generating part284). Thus, a feed angle of a label PL relative to the heat generating part284can be small (in other words, it can be an angle approximately perpendicular to the heat generating part284in a side view) (refer toFIG.3). Here, good print quality is obtained due to the following reasons. The heat generating part284includes a glaze layer (partial graze) generally having a protrusion shape, and it thereby has a protrusion shape as a whole. If tall surface-mount devices are disposed on the rear side of the thermal head28, the feeding angle of a label PL relative to the heat generating part284is made large in order to avoid the tall surface-mount devices. In this case, due to the heat generating part284having a protrusion shape and to stiffness (resilience) of a label PL, the label PL tends to rise from the heat generating part284at the position thereof, and it is difficult to apply an appropriate printing pressure to the label PL between the heat generating part284and the platen roller10. In contrast, for a small feeding angle of a label PL relative to the heat generating part284, although having a protrusion shape, the heat generating part284pinches a label PL with the platen roller10by applying an appropriate printing pressure, in the vicinity of a top of the heat generating part284. Thus, good print quality is obtained.

A pair of shafts28athat extend outward are coupled to both end surfaces of the heat dissipation plate281. As described later, the pair of shafts28aare provided in order to mount the thermal head28to the internal frame of the printer1. As shown inFIGS.16A and16B, the shaft28ahas a large-diameter part joined to the heat dissipation plate281and has a small-diameter part extending outward from the large-diameter part, and it thereby has a high strength. The small-diameter part of the shaft28ais inserted in a shaft-receiving groove25, which will be described later.

FIG.18is a partial sectional view of the printer1in a plane perpendicular to the right-left direction, in the state in which the peeling unit open button52bis continuously pressed down to make the peeling roller cover41be at the open position and to make the peeling roller holder42be at the protruding position.FIG.18does not show the thermal head28and the coil spring55, in order to make the shaft-receiving groove25, into which the shaft28aof the thermal head28is inserted, clearly visible.

As shown inFIG.18, the internal frame of the printer1is formed with the shaft-receiving groove25having a substantially L-shape. AlthoughFIG.18shows only a shaft-receiving groove25that receives one of the pair of shafts28aof the thermal head28, another shaft-receiving groove25that receives the other shaft28ais also formed in the same manner.

As shown by the enlarged drawing inFIG.18, the shaft-receiving groove25has a first groove251and a second groove252. Herein, each of positions P1and P2shows a position where the shaft28acan be in the shaft-receiving groove25, in a virtual manner. In this disclosure, the state in which the shaft28ais at the position P1may be referred to as a state in which the thermal head28is at the position P1; the state in which the shaft28ais at the position P2may be referred to as a state in which the thermal head28is at the position P2.

The first groove251extends in a direction in which the thermal head28moves to and away from the position P1. The second groove252extends from the position P1to the position P2in a direction in which the coil spring55in front of the thermal head28biases the thermal head28(that is, in a rear direction). The shaft-receiving groove25is an L-shaped groove composed of the first groove251and the second groove252, and therefore, the position of the thermal head28can be switched between two positions P1, P2by this relatively simple shape. Herein, the position P2is a position at which the thermal head28cannot be removed by moving it upward, while the position P1is a position at which the thermal head28can be removed by moving it upward.

The thermal head28is movable between the positions P1and P2in the direction of being biased by the coil spring55. Thus, in mounting the thermal head28, the thermal head28can be easily set to the position P2due to the biasing force of the coil spring55, simply by inserting the shaft28ato the position P1along the first groove251.

Next, a method of replacing the thermal head28will be described with reference toFIG.19.

FIG.19illustrates a method of replacing the thermal head28and shows partial side views of a replacement-target thermal head28in states S20and S21.

Normally, the replacement-target thermal head28, which is mounted to the printer1, is disposed at the position P2of the shaft-receiving groove25, as shown by the state S20. In this state, the whole thermal head28is biased to the platen roller10(not shown inFIG.19) (that is, in the rear direction) by the biasing force of the coil spring55, and the shaft28aof the thermal head28is thereby stably positioned at the position P2.

In order to remove the replacement-target thermal head28, it is moved from the position P2to the position P1in a direction opposite to a first direction, against the biasing force of the coil spring55, as shown by the state S21. The first direction is a direction in which the coil spring55biases the thermal head28, and the direction opposite to the first direction is a front direction. Subsequently, the replacement-target thermal head28is moved upward from the position P1, and the shaft28aof the replacement-target thermal head28is removed from the shaft-receiving groove25, whereby the replacement-target thermal head28is removed. At this time, the flexible cable57is connected to the connector285of the replacement-target thermal head28(refer toFIG.21). Thus, the flexible cable57is disconnected from the connector285of the replacement-target thermal head28.

After the replacement-target thermal head28is detached from the flexible cable57, a new thermal head28may be mounted to the printer1in a procedure reverse to the procedure of taking out the thermal head28.

Specifically, the disconnected flexible cable57is first connected to the connector285of a new thermal head28(refer toFIG.16A). The new thermal head28is then inserted into the position P1and is moved from the position P1to the position P2by the biasing force of the coil spring55. In more detail, the new thermal head28is moved downward, and the shaft28aof the new thermal head28is inserted into the shaft-receiving groove25from the first groove251(refer toFIG.18). At this time, insertion is performed while the end of the coil spring55(rear end of the coil spring55) is pressed forward (in the direction against the biasing force of the coil spring55) by the back surface281b(surface facing forward of the printer1) of the new thermal head28. Upon reaching the position P1, the shaft28aof the new thermal head28is moved to the position P2by the biasing force of the coil spring55, without requiring an operating force of an operator. Thus, the thermal head28is replaced as described above.

The thermal head28is not disposed with the surface-mount devices, such as the connector, on the rear side (on the side disposed with the heat generating part284), as shown inFIG.16B, and it is thereby easy to replace. Also, in consideration of the coil spring55biasing the thermal head28rearward, if the thermal head28did not have a flat rear side, it would interfere with the internal frame on a rear side (e.g., a wall surface21; refer toFIG.20) and would be difficult to smoothly insert into the shaft-receiving groove25. In contrast, due to the thermal head28having a flat rear side, the new thermal head28can be smoothly inserted into the shaft-receiving groove25, although biased by the coil spring55.

Mounting and removing of the thermal head28are performed when the peeling unit4is at the open position. In more detail, the peeling unit4at the closed position covers at least a part of the thermal head28, whereas the peeling unit4at the open position does not cover the thermal head28, as shown inFIG.2. In view of this, mounting and removing of the thermal head28are performed when the peeling unit4is at the open position.

When the peeling unit4is at the closed position, none of other member is interposed between the peeling unit4and the thermal head28, and the peeling unit4directly covers at least a part of the thermal head28.

With reference again toFIG.18, in the state in which the peeling roller cover41is at the open position (that is, the peeling unit4is at the open position), space for allowing mounting and removing the thermal head28having the shaft28aat the position P1, is formed. Thus, an operator can remove the thermal head28from the printer1in accordance with merely the following operation process: opening the printer cover3; continuously pressing down the peeling unit open button52bto make the peeling unit4be in the state shown inFIG.18; as described above, sliding the shaft28aof the thermal head28from the position P2to the position P1against the biasing force of the coil spring55; and pulling up the thermal head28.

In addition, in the printer1of this embodiment, at least a part of the rear side of the thermal head28is exposed to the paper roll-containing chamber9, as shown inFIG.2. With this structure, working space for taking out the thermal head28is ensured by temporarily removing the paper roll “R,” which enables more easily taking out the thermal head28. Specifically, in sliding the shaft28aof the thermal head28from the position P2to the position P1, an operator needs to apply an operating force to the thermal head28from a rear side to a front side, but the operating force is easily applied due to the space behind the thermal head28. Moreover, in pulling up the thermal head28, the space behind the thermal head28helps an operator in putting a hand therein and pulling up.

In mounting the thermal head28to the printer1, an operation is performed in the order reverse to the operation in taking out the thermal head28from the printer1. As in the case described above, the peeling unit4is set to the state shown inFIG.18. Then, the shaft28aof the thermal head28is inserted into the position P1from the first groove251of the shaft-receiving groove25while the end of the coil spring55(rear end of the coil spring55) is pressed forward (in the direction against the biasing force of the coil spring55) by the back surface281b(surface facing forward of the printer1) of the thermal head28. The thermal head28is then moved to the position P2by the biasing force of the coil spring55.

Thus, the thermal head28can be easily replaced without using tools.

In another embodiment, the shaft-receiving groove may have another shape, instead of the L-shape. The shaft-receiving groove may have, for example, a groove extending obliquely forward or extending obliquely rearward from the position P1, as long as the thermal head28can be attached and removed from the position P1. Alternatively, the shaft-receiving groove may have a U-shaped groove path between the positions P1and P2in such a manner that the position P2is provided at a position that the path reaches after starting from the position P1inFIG.18, extending forward, extending slightly downward, and then extending rearward, although this structure causes mounting and removing the thermal head28to be a little difficult. In this case, an operator can remove the shaft28aof the thermal head28by moving it from the position P2to the position P1along the U-shaped groove.

Support Structure of Thermal Head28

Next, a support structure of the thermal head28will be described with reference toFIGS.20,21A, and21B.

First, a structure of the internal frame on a rear side of the thermal head28will be described with reference toFIG.20.FIG.20is a perspective view of a part of the internal frame along with components attached to the internal frame, a part of which is enlarged.FIG.20does not show the thermal head28.

As shown inFIG.20, the internal frame has a wall surface21that is configured to face the rear surface of the thermal head28, behind an area to be disposed with the thermal head28(on a paper roll-containing chamber9side). The wall surface21is formed with a protrusion211. The protrusion211abuts on the rear surface of the thermal head28that is mounted. As shown inFIG.20, the abutting surface of the protrusion211is preferably curved so as to be convex toward the rear surface of the thermal head28.

FIGS.21A and21Bboth illustrate forces that act on the thermal head28in the printer1of this embodiment;FIG.21Ashows a cross section in a plane perpendicular to the upper-lower direction, andFIG.21Bshows a cross section in a plane perpendicular to the right-left direction.FIGS.21A and21Bhave scales different from each other.

As shown inFIG.21A, the protrusion211is provided at a position at which it abuts on a substantially center part in the right-left direction of the thermal head28that is mounted. In addition, the protrusion211is provided at a position at which it abuts on a substantially center position in the right-left direction between the pair of coil springs55, of the rear side of the thermal head28.

The cutout283c(refer toFIG.16B) is provided at the approximate center in the right-left direction of the thermal head28, as described above, and the protrusion211abuts on the thermal head28at the cutout283c. The cutout283cis not covered with the board282and exposes the heat dissipation plate281of the thermal head28, whereby the thermal head28is more stably supported.

It should be noted that the cutout283cis not necessarily provided. The protrusion211may support the thermal head28at an area of the board282, without the cutout283cprovided.

The rear surface of the thermal head28is preferably provided with a recess having a shape corresponding to the protrusion211, at the position for abutting on the protrusion211. This causes the thermal head28to hardly deviate from the position for abutting on the protrusion211and to be more stably supported.

In an embodiment, a recess may be provided in the wall surface21of the internal frame, whereas the rear surface of the thermal head28may be provided with a protrusion having a shape corresponding to the recess of the wall surface21. In this case, the thermal head28is also able to swing, but it is stably supported.

The shape of the protrusion211shown inFIG.20is merely an example, and it can be another shape that swingably supports the thermal head28. For example, the outer shape of the protrusion211may be a part of a spherical surface, instead of the shape shown inFIG.20.

As shown inFIG.21A, in a plane view of the printer1, rearward restoring forces F1and F2of the pair of coil springs55act on the front side of the thermal head28, whereas a reaction force F3acts from the protrusion211abutting on the rear side of the thermal head28. Herein, the protrusion211is at the approximate center position in a top view of the printer1, and thus, the thermal head28is able to swing around a fulcrum at the protrusion211, in a clockwise direction and a counterclockwise direction inFIG.21A.

As shown inFIG.21B, in a side view of the printer1, the rearward restoring forces F1and F2(restoring force F2is not visible inFIG.21B) of the pair of coil springs55act on the front side of the thermal head28. A reaction force F4from the platen roller10acts on the rear side of the thermal head28, above the points of application of the restoring forces F1and F2. The reaction force F3from the protrusion211acts on the rear side of the thermal head28, under the points of application of the restoring forces F1and F2. Thus, the thermal head28is able to swing around a fulcrum at the protrusion211, in a clockwise direction and a counterclockwise direction inFIG.21B.

In addition, in a side view of the printer1, the points of applying the biasing forces of the coil springs55to the thermal head28are between the position at which the thermal head28receives the reaction force from the platen roller10and the position at which the protrusion211supports the rear side of the thermal head28. With this structure, the biasing forces of the coil springs55are received at an upper part and a lower part, whereby the thermal head28is supported with good balance.

InFIG.21B, the surface on which the protrusion211abuts (that is, the surface on which the heat dissipation plate281is exposed by the cutout283c), and the surface corresponding to the heat generating part284, are preferably in the same reference plane on the rear side of the thermal head28. This enables pressing the heating elements of the thermal head28against the platen roller10at an appropriate angle.

As shown inFIGS.21A and21B, the thermal head28is able to swing around a fulcrum at the protrusion211in a clockwise swinging direction and a counterclockwise swinging direction in a side view of the printer1. The thermal head28is also able to swing around a fulcrum at the protrusion211in a clockwise swinging direction and a counterclockwise swinging direction in a plane view of the printer1. Thus, the thermal head28uniformly applies pressure to the platen roller10in printing. The reason of this is as follows.

In a printer having an existing thermal head, the thermal head is fixed, for example, at two points, by using screws, shafts, brackets, or the like, so as to be mounted to an internal frame or a housing of the printer. In such a case, due to deviation of the mounted position, the pressure of the thermal head abutting on a platen roller may not be uniform in an axial direction of the platen roller, which may cause degradation in print quality.

On the other hand, in this embodiment, the thermal head28is able to swing around a fulcrum at the protrusion211in a side view and in a plane view of the printer1. With this structure, the thermal head28can follow and maintain uniform pressure on the platen roller10, for example, even when there is a mounting error of the platen roller10, circular runout of the platen roller10is large in rotating, or a rugged surface label is temporarily attached on a liner.

Moreover, the thermal head28is movable between the positions P1and P2(refer toFIG.18) in the direction of being biased by the coil spring55, and thus, the thermal head28is not prevented from swinging around a fulcrum at the protrusion211.

In some printers having an existing thermal head, a fulcrum shaft is provided at a lower part of the thermal head, and this shaft is fixed to a printer body to enable the thermal head to swing in a side view. However, unlike the printer1, this thermal head cannot be replaced without using tools. On the other hand, the printer1is superior to existing ones in that the thermal head28can be replaced without using tools while enabling to swing in a side view and in a plane view of the printer1.

In another embodiment, protrusions211may be provided at two positions separated in the right-left direction on the wall surface21shown inFIG.20. Also in this case, the thermal head28is able to swing around fulcrums at the protrusions211in a side view of the printer1. Even in the case in which the thermal head28is able to swing only in a side view of the printer1, degradation in print quality is prevented.

In another embodiment, protrusions211may be provided at two positions separated in the upper-lower direction on the wall surface21shown inFIG.20. Also in this case, the thermal head28is able to swing around fulcrums at the protrusions211in a plane view of the printer1. Even in the case in which the thermal head28is able to swing only in a plane view of the printer1, degradation in print quality is prevented.

As shown inFIG.16A, the flexible cable57is detachably connected to the thermal head28. The flexible cable57is connected from the connector285of the thermal head28that is mounted to the printer1, to the circuit board (not shown) at a front part of the printer1, as shown inFIG.21B. The flexible cable57is fixed at a fixing position24aon an upper surface of a bracket24in front of the thermal head28, for example, by screwing or adhesive.

A cable-containing chamber59for containing the flexible cable57is formed between the thermal head28and the circuit board. The cable-containing chamber59is configured to contain the relatively long flexible cable57between the connector of the thermal head28and the fixing position24a. With this structure, when removed, the thermal head28can be moved to a position sufficiently higher than the printer1based on the fixed position24a. This makes it easy to remove the flexible cable57from the connector of the thermal head28and to replace with a new thermal head28.

However, the cable-containing chamber59is not necessarily formed. Even in this case, although the cable length from the connector285of the thermal head28to the fixing position24ais reduced, it is possible to remove the flexible cable57from the connector285and to replace the thermal head28.

As shown inFIGS.21A and21B, the cable-containing chamber59is formed in space between the platen-holding bracket27and the thermal head28. Thus, the space that is formed by the platen-holding bracket27having a U-shape in a plane view is efficiently used.

The cable-containing chamber59may not be formed as the space between the platen-holding bracket27and the thermal head28. In one example, the flexible cable57extending from the connector of the thermal head28may be passed under the platen-holding bracket27, and a containing chamber may be provided on a front side of the platen-holding bracket27.

As described above, in the printer1, the surface-mount devices are not mounted on the rear surface of the thermal head28and are thereby protected from water, etc., which may enter from the ejection part20.

In the printer1, space for allowing mounting and removing the thermal head28is formed when the peeling unit4is at the open position not covering the thermal head28, which improves the workability in replacing the thermal head28. Moreover, the thermal head28is biased rearward (in a direction to the platen roller10) and is movable along this direction between the first position for allowing mounting and removing the thermal head28and the second position for restricting mounting and removing of the thermal head28. Thus, the thermal head28can be removed only by moving it from the second position to the first position, and tools and the like are not necessary.

In the printer1, the thermal head28is able to swing around a fulcrum at the protrusion211in a clockwise swinging direction and a counterclockwise swinging direction in a side view of the printer1, and the thermal head28is also able to swing around a fulcrum at the protrusion211in a clockwise swinging direction and a counterclockwise swinging direction in a plane view of the printer1. Thus, the thermal head28uniformly applies pressure to the platen roller10in printing, and it is possible to prevent degradation in print quality due to the method of mounting the thermal head.

Another Embodiment of Thermal Head

Next, a thermal head28A according to another embodiment will be described with reference toFIGS.22A to25.

FIG.22Ais a perspective front view of the thermal head28A, andFIG.22Bis a perspective rear view of the thermal head28A.FIG.23is a perspective view of a plate member included in the thermal head28A.FIG.24is a perspective view of the thermal head28A, as seen from a viewpoint different from those ofFIGS.22A and22B.

It is clear from a comparison betweenFIGS.22A and22BandFIGS.16A and16Bthat the thermal head28A differs from the thermal head28in having a plate member7.

The plate member7, which is a member formed of a metal material such as stainless steel, is fastened to the heat dissipation plate281with screws. As shown inFIG.23, the plate member7has a base71, projecting pieces72L and72R, and a projecting plate73.

The projecting pieces72L and72R project from both ends of the base71in a direction perpendicular to a main surface of the base71(that is, in a direction perpendicular to the surface281awhen they are attached to the heat dissipation plate281). In the state in which the plate member7is attached to the heat dissipation plate281, the projecting pieces72L and72R project on a side mounted with the heat generating part284, as shown inFIG.24. The projecting pieces72L and72R have edge parts721L and721R at ends.

The projecting piece72L is formed with a hole72a, whereas the projecting piece72R is formed with a U-shaped groove72b. As shown inFIGS.22A and22B, one of the pair of shafts28ais inserted in the hole72a, and the other shaft28ais inserted in the U-shaped groove72b. One of the edge parts721L and721R is formed with a hole, and the other is formed with a U-shaped groove. This facilitates attaching the plate member7to the heat dissipation plate281.

In the state in which the plate member7is attached to the heat dissipation plate281, the projecting plate73projects on a side mounted with the relatively tall surface-mount devices (e.g., the connector285, the EEPROM286, and the diode287), as shown inFIG.22A.

The projecting plate73is provided between the projecting pieces72L and72R over the longitudinal direction of the base71and projects from the base71in a direction opposite to the projecting pieces72L and72R.

The base71is formed with two holes71afor allowing screws to pass in mounting the plate member7to the heat dissipation plate281. The base71has two projections711. As shown inFIG.22A, the projections711are disposed so as to not interfere with the surface-mount devices when the plate member7is attached to the heat dissipation plate281.

Hereinafter, effects of the thermal head28A having the plate member7will be described with reference toFIG.25.FIG.25is a side view showing a positional relationship between the thermal head28A and the platen-holding bracket27.

As described above, when the printer cover3is at the closed position, the platen shaft10aof the platen roller10, which is attached to the printer cover3, is fitted in the groove27bof the platen-holding bracket27, whereby the printer cover3is held. In a case of the thermal head28that does not have the plate member7, when an operator presses the printer cover3from above, for closing the printer cover3for example, the platen roller10may deviate downward from a designed position at which the platen roller10and the thermal head28abut on each other. This causes variations in density of printing. Further, the thermal head28is fitted to the shaft-receiving groove25(refer toFIG.18), which is provided in the internal frame. The one end of the shaft27aof the platen-holding bracket27is inserted in the boss52aof the peeling unit open lever52, whereas the other end of the shaft27ais inserted in the boss provided to the internal frame (refer toFIG.5). Thus, the position at which the platen roller10and the thermal head28abut on each other is susceptible to accumulated errors in assembling components and tends to deviate from the designed position.

The drawback of the thermal head28noted above is overcome by the thermal head28A.

As shown by an enlarged drawing inFIG.25, in the case in which the thermal head28A is mounted to the printer1, instead of the thermal head28, upper ends of the edge parts721L and721R of the plate member7of the thermal head28A are disposed at positions higher than rims that form the grooves27bof the platen-holding bracket27. Thus, the platen shaft10athat is fitted in the platen-holding bracket27is in contact with the edge parts721L and721R in the grooves27b. This makes it difficult for the platen roller10to deviate downward from the designed position at which the platen roller10and the thermal head28abut on each other, even when an operator presses the printer cover3from above. This is because the plate member7is integrally coupled to the heat dissipation plate281mounted with the heat generating part284, whereby a relative positional relationship between the platen roller10and the heat generating part284is unlikely to be affected even when the platen shaft10apresses down the edge parts721L and721R.

With reference again toFIG.25, in the state in which the thermal head28A is mounted to the printer1, the projecting plate73of the plate member7projects toward the front side of the printer1. Thus, an upper part of the cable-containing chamber59, which is formed in front of the thermal head28A, is covered with the projecting plate73. This structure prevents dust from entering the printer1from the outside, resulting in preventing dust from adhering to upper surface portions of the surface-mount devices disposed on the front side of the thermal head28A. That is, the projecting plate73functions as a hood. In particular, as shown inFIG.2, replacement of the paper roll “R” is performed while the printer cover3is maintained at the open position, and dust tends to enter the printer1. However, in this situation, it is also possible to protect the surface-mount devices of the thermal head28A from dust.

From another point of view, providing the projecting plate73improves strength of the plate member7.

Although some embodiments of the printer of the present invention are described above, the present invention should not be limited to the foregoing embodiments. In addition, the embodiments described above can be variously modified and altered within the scope not departing from the gist of the present invention. For example, respective technical features described in the foregoing embodiments can be combined with one another as appropriate, unless technical contradiction occurs.

For example, the structures and the mounting and removing methods of the thermal heads28and28A are not technically related to the structure of the peeling unit4and the method of switching the issue modes, and therefore, they may be employed in a printer without the peeling unit4. Conversely, the structure of the peeling unit4and the method of switching the issue modes may be employed in a printer that uses a structure and an mounting and removing method of a thermal head different from those of the thermal heads28and28A.

A case in which some parts (e.g., shafts and ends of springs) of components inside the printer1are coupled to the internal frame is described here; but the structure is not limited thereto, and these parts may be coupled to the body case2.

Although a case of using a print medium that is a continuous paper having a plurality of labels temporarily attached on a liner is described in the foregoing embodiments, the print medium is not limited thereto. For continuous issuing or for a printer not provided with a peeling unit, for example, a continuous label having an adhesive surface on one side (label without a liner), a continuous sheet without an adhesive surface (continuous sheet), or a material other than papers such as a film, which is printable by a thermal head, may also be used as a print medium. In addition, in a case of feeding a label having an exposed adhesive due to no liner, a feeding path may be coated with a non-adhesive material, and a non-adhesive roller containing silicone or the like may be provided as a platen roller.

The present invention is related to Japanese Patent Application No. 2020-191682 filed with the Japan Patent Office on Nov. 18, 2020, the entire contents of which are incorporated into this specification by reference.