JP4280852B2 - Thermal printer - Google Patents

Description

  The present invention relates to a thermal printer provided with an openable / closable cover.

2. Description of the Related Art A thermal printer in which a cover is attached to a printer main body so as to be able to open and close is known, in which a thermal head is provided on the printer main body side and a platen roller is provided on the cover side. ). Here, in order to obtain a desired conveying force and printing pressure, the thermal head is pressed against the platen roller in the closed state. In this thermal printer, the closed state is maintained by the printer main body and the cover being engaged with each other by the lock mechanism, and the open state is established by releasing the engagement of the lock mechanism and releasing the cover from the printer main body.
US Pat. No. 3,118,469

  However, in the thermal printer configured as described above, since the thermal head is pressed against the platen roller in the closed state and a frictional force is generated, even if the engagement of the lock mechanism is released, the frictional force becomes a resistance and opens and closes. May be difficult.

  Accordingly, an object of the present invention is to provide a thermal printer that can be opened and closed easily and smoothly.

A thermal printer according to an example of the present invention includes a printer main body, a cover attached to the printer main body so as to be rotatable between a closed state and an open state, a platen roller provided on the cover, and the printer main body. A thermal head that is disposed opposite to the platen roller in the closed state and presses the platen roller, a lock mechanism that engages and releases the printer body and the cover, and the thermal head and the lock mechanism. And an interlocking member that retracts the thermal head from the platen roller when the lock mechanism is disengaged, and the lock mechanism has an engagement position and a release position with respect to the printer main body. It is attached so that it can rotate centering on the 1st rotation fulcrum between, and the cover part on one side centering on the 1st rotation fulcrum The thermal head is attached to the printer main body so as to be rotatable around a second rotation fulcrum. The thermal head includes an engaging claw having an engaging portion that engages and the other side is connected to the interlocking member. The heat sink is connected to the interlocking member on the opposite side of the pressing portion where the thermal head presses the platen roller around the second rotation fulcrum, and the engagement position of the lock mechanism As the heat sink rotates through the interlocking member with the rotation from the release position to the release position, the thermal head retracts from the platen roller at the pressing portion .

  In the thermal printer of the present invention, since the interlock member is provided, the thermal head is retracted from the platen roller when the lock member is disengaged, so that the thermal printer can be opened and closed easily and smoothly.

A thermal printer 10 according to an embodiment of the present invention will be described below with reference to FIGS.
FIG. 1 schematically shows the inside of the thermal printer 10. The thermal printer 10 has a function of printing on the thermal paper 11, and can be used for a cash register machine such as a store.

  The thermal printer 10 includes a printer main body 12 having an upper opening and a cover 14 that covers the opening. The cover 14 is attached to a hinge portion 15 formed above the printer body 12 so as to be able to open and close.

  The hinge portion 15 is provided with a torsion spring 16 as an urging member. One end of the torsion spring 16 is in contact with the printer main body 12, and the other end is in contact with the cover 14. The torsion spring 16 biases the cover 14 in the opening direction with respect to the printer main body 12.

  Engagement pins 19 are provided on the sides of the cover 14. The engagement pin 19 is formed in a cylindrical shape whose axis extends horizontally, and is positioned inside an engagement recess 33 of an engagement claw 30 described later in the closed state, and engages with the engagement recess 33.

  An operation member 20 for rotating the engagement claw 30 is provided on the upper portion of the cover 14. The operation member 20 has a shaft portion 21 that is inserted through a hole formed in the upper surface of the cover 14. An inclined surface 21 a that contacts the engaging claw 30 is formed at the tip of the shaft portion 21. A disc-shaped button portion 22 having a diameter larger than that of the hole portion is connected to the upper side of the shaft portion 21. An elastic body 23 is provided between the button portion 22 and the upper surface of the cover 14. The elastic body 23 is, for example, a coiled spring disposed around the shaft portion 21 and biases the operation member 20 upward. When an operator applies a certain force below the button portion 22, the elastic body 23 expands and contracts and the operation member 20 linearly moves downward. When the force is released, the operation member 20 is raised to the original position by the elastic restoring force of the elastic body 23.

  A platen roller 25 is provided at the front end of the cover 14. The platen roller 25 is integrally attached to a rotatable platen shaft 27 that is supported on the left and right sides of the cover 14 via a bearing 26 and extends in the horizontal direction. The platen roller 25 is formed in a columnar shape extending in the horizontal direction and can rotate integrally with the platen shaft 27. The platen roller 25 is made of an elastic material having rubber elasticity such as NBR (nitrile rubber) and having a friction coefficient larger than that of metal. The platen roller 25 is disposed so as to face a thermal head 41 (to be described later) with the thermal paper 11 interposed therebetween in the closed state.

  Further, a cutter mechanism 28 for cutting the thermal paper 11 is provided above the platen roller 25 in the closed state.

  A paper storage unit 29 that stores the thermal paper 11 is provided in the rear of the printer main body 12. The thermal paper 11 includes a base paper and a heat-sensitive layer formed on one surface (for example, the front surface) of the base paper. The heat-sensitive layer is made of a material that develops a desired color such as black or red when heated to a predetermined temperature or higher. The thermal paper 11 is arranged in the paper storage unit 29 in a state of being wound in a roll shape as shown in FIG. 1 so that the heat-sensitive layer faces outward.

  An engaging claw 30 that constitutes an example of a lock mechanism is attached to a side portion of the printer main body 12 via a first rotation shaft 31. The engaging claw 30 is configured to be rotatable about the first rotation shaft 31. A slope 32 is formed at the upper end of the engaging claw 30. An engagement recess 33 that engages with the engagement pin 19 is formed at the upper rear of the engagement claw 30. One end of a link member 50 as an example of an interlocking member is attached to the opposite side of the engaging recess 33 around the first rotation shaft 31, that is, the lower portion 34. One end of the elastic member 52 is attached to the lower end of the engaging claw 30.

  A thermal head unit 40 is provided at the front end of the printer main body 12. The thermal head unit 40 includes a thermal head 41, a heat sink 42, an urging means 43, and a spring seat 44. The heat sink 42 attached to the printer main body 12 so as to be rotatable about the second rotation shaft 45 has a function as a heat dissipation structure. The thermal head 41 is attached to the heat sink 42 and is pressed toward the platen roller 25 on the upper end side from the second rotation shaft 45.

  A long hole-like attachment portion 46 to which the link member 50 is attached is formed at an end portion of the heat sink 42 below the second rotation shaft 45. The end portion of the link member 50 is rotatably attached to the attachment portion 46 with a clearance. Due to this clearance, the engagement claw 30 does not rotate unless a certain force or more is applied to the button portion 22, so that a constant printing pressure is ensured during normal times.

  The thermal head 41 is disposed in a rearward and vertical (substantially vertical) posture. The thermal head 41 is disposed so as to be in contact with the heat sensitive layer of the thermal paper 11 in the closed state and to face the platen roller 25 with the thermal paper 11 interposed therebetween.

  An urging means 43 is provided on the back side of the heat sink 42, that is, on the side opposite to the thermal head 41. An example of the biasing means 43 is a spring member such as a compression coil spring or a torsion spring, and is arranged in a compressed state between a spring seat 44 provided at the front end portion of the printer main body 12 and the heat sink 42. . In the closed state, the urging unit 43 presses the thermal head 41 toward the platen roller 25 in the direction of arrow A in FIG.

  The link member 50 that connects the heat sink 42 and the engaging claw 30 is formed in a bar shape. One end of the link member 50 is fixed to the lower portion of the engaging claw 30, and the other end is attached to the attachment portion 46 of the heat sink 42 with a clearance.

  The elastic member 52 is composed of, for example, an elastic spring member. One end 54 of the elastic member 52 is connected to the printer main body 12, and the other end 53 is connected to the lower end 35 of the engaging claw 30. When the button 22 is pressed down with a certain force or more, the engaging claw 30 tilts and the elastic member 52 extends. The elastic member 52 is reduced when the force applied to the button portion 22 is removed, and the lower end 35 of the engaging claw 30 is pulled by the elastic restoring force, thereby restricting the inclination of the engaging claw 30.

  A motor 60 as a drive source is attached to the front of the sheet storage portion 29 inside the printer main body 12 via an attachment portion. The motor 60 is, for example, a stepping motor that can rotate forward and backward, and can perform reverse feed printing. The motor 60 includes an output shaft 61 and an output gear 62 that rotates integrally with the output shaft 61.

  A drive gear 63 is provided in front of and above the motor 60. The drive gear 63 is disposed so as to mesh with the output gear 62. The drive gear 63 is integrally attached to a rotatable shaft 65 that is supported on the left and right side walls of the printer main body 12 via a bearing 64 and extends in the horizontal direction.

  Further, a platen gear 70 is integrally attached to the platen shaft 27 next to the platen roller 25 at the tip of the cover 14. The platen gear 70 is disposed so as to mesh with the drive gear 63 in the closed state. That is, the platen gear 70, the platen shaft 27, and the platen roller 25 are configured to rotate integrally with the rotation of the drive gear 63.

  The leading end portion of the roll-shaped thermal paper 11 stored in the paper storage portion 29 advances in the vertical direction from the bottom to the top between the thermal head 41 and the platen roller 25, passes through the cutter mechanism 28, and then has an arrow. It is discharged upwards as indicated by B.

Next, the operation of the thermal printer 10 according to the present embodiment will be described.
In the closed state shown in FIG. 1, the operation member 20 is pushed up by the elastic body 23 and is positioned above. At this time, the engaging claw 30 is erected and the engaging pin 19 is in the engaged state where it is positioned in the engaging recess 33. The thermal head 41 is pressed in the direction of the platen roller 25 across the thermal paper 11 at the upper pressing portion. For this reason, a frictional force is generated among the thermal head 41, the platen roller 25, and the thermal paper 11. At this time, the platen gear 70 and the drive gear 63 are engaged with each other, and power transmission is possible.

  When the motor 60 is driven in this state, the output gear of the motor 60 rotates in the R1 direction, for example, and the drive gear 63 rotates in the R2 direction by this rotation. Further, the platen gear 70 meshed with the drive gear 63 rotates in the R3 direction, and the platen roller 25 attached to the platen shaft 27 also rotates integrally in the R3 direction. At this time, the thermal paper 11 is conveyed by frictional force between the thermal head 41 and printing is performed. The paper advances upward between the platen roller 25 and the thermal head 41.

  Here, as shown in FIG. 2, when a certain downward force is input to the button portion 22 of the operation member 20, the button portion 22 linearly moves downward while compressing the elastic body 23. When the inclined surface 21a formed at the tip of the shaft portion 21 material pushes the inclined surface 32 provided at the upper end of the engaging claw 30, the engaging claw 30 rotates in the R4 direction. By this rotation, the engaging recess 33 moves forward and retracts from the engaging pin 19. Thus, the engagement pin 19 is disengaged from the engagement recess 33, and the release state is established. As the engagement claw 30 rotates, the link member 50 connected to the lower portion 34 of the engagement claw 30 is pulled backward. The elastic member 52 attached to the portion 35 at the lower end of the engaging claw 30 is pulled and extended, and an elastic restoring force is generated. When the link member 50 moves rearward by a predetermined value or more determined by the clearance provided in the attachment portion 46, the lower end portion 46 of the heat sink 42 is pulled rearward. Accordingly, the heat sink 42 rotates about the second rotation shaft 45 in the R5 direction. The thermal head 41 formed on the heat sink 42 rotates in the R5 direction and retracts from the platen roller 25. At this time, the thermal head 41 is retracted in a direction away from the movement locus of the platen roller 25 that moves as the cover 14 is opened and closed. In this way, the frictional force by the thermal head 41 and the platen roller 25 is removed. As a result, the cover 14 is rotated about the hinge portion 15 in the R6 opening direction by the inactive force of the torsion spring 16, and the open state shown in FIG. 3 is obtained. When the force that presses the button portion 22 is released after the engaged state is released, the lower end 35 of the engaging claw 30 is pulled forward by the elastic member 52, and the engaging claw 30 stands up. Along with this, the link member 50 returns to the rear again, and the thermal head 41 also rotates in the opposite direction of R5 to return to the same posture as in the closed state. When the cover 14 is opened, the platen roller 25 is separated from the thermal head 41 and the platen gear 70 is separated from the drive gear 63. Thus, the upper surface side of the printer main body 12 is opened, and the thermal head 41 and the platen roller 25 are completely exposed to the outside. Here, the engagement state is released with the rotation of the engagement claw 30 and the thermal head 41 is retracted, whichever is applicable first, but the thermal head 41 is retracted in advance. With this configuration, the surface of the platen roller 25 and the thermal head 41 can be protected.

  When the cover 14 is closed, a force of a certain level or more is applied to the end portion of the cover 14 positioned above in the open state to rotate the cover 14 in the direction opposite to the R6 direction. When force is continuously applied after the engagement pin 19 abuts on the upper end of the engagement claw 30, the engagement claw 30 rotates and the engagement pin 19 slides on the slope 32 at the upper end of the engagement claw 30. Moving. At this time, the engaging claw 30 rotates in the R4 direction and the thermal head 41 rotates in the R5 direction, and is in a state of being retracted from the platen roller 25. When the engagement pin 19 reaches the position of the engagement recess 33, the engagement pin 19 enters the inside of the engagement recess 33, and the engagement claw 30 stands up to return to the original posture. Thus, the cover 14 covers the upper surface of the printer main body 12 and is closed, and the closed state is maintained by the engagement of the engagement recess 33 and the engagement pin 19.

The thermal printer 10 according to the present embodiment has the following effects.
By providing the link member 50 that connects the lower end of the heat sink 42 and the lower end of the engaging claw 30, the thermal head 41 can be retracted from the platen roller 25 when releasing the engagement with a simple configuration. Therefore, the frictional force that becomes resistance can be released. Since it retracts even when it is closed, it is possible to prevent the surfaces of the platen roller 25 and the thermal head 41 from coming into contact with each other and being damaged. In the open state, the platen roller 25 and the thermal head 41 are separated from each other, so that the thermal paper 11 can be easily set. Further, since the platen roller 25 is provided on the cover 14 side and the thermal head unit 40 is provided on the printer main body 12 side, the configuration of the cover 14 can be made simple and lightweight.

  When the force is not applied by the elastic member 52 that can be expanded and contracted, the inclination of the engaging claw 30 can be regulated. Further, since the mounting portion 46 is formed in a long hole shape and a clearance is provided, the thermal head 41 does not move unless a force of a predetermined value or more is input, so that the printing pressure during normal times other than opening and closing is stabilized. Can do. Further, since the torsion spring 16 is provided on the hinge portion 15, the hinge portion 15 can be easily opened simply by pressing the operation member 20. The torsion spring 16 can prevent the cover 14 from being closed during sheet replacement in the open state. In addition, when closing, a certain operation feeling is accompanied until the engaged state is reached, so that a reliable operation can be promoted.

  The present invention is not limited to the above embodiment. For example, in the first embodiment described above, the case where the torsion spring 16 is used as the urging member is shown, but in addition, a cam mechanism 80 as shown in FIG. 4 may be used. Here, the cam mechanism 80 as an urging member includes a spring member 81 that can expand and contract, and a cam portion 82. The spring member 81 has one end 81 a attached to the cover 14 and the other end 81 b connected to the cam portion 82. The cam portion 82 is rotatably attached to the cover 14, and a spring member is attached to one end 82a thereof. The other end 82b of the cam portion is in contact with the side upper end 12a of the printer main body 12 in the closed state. In this closed state, the spring member 81 is pulled by the cam portion 82 and is in an extended state. When the engagement of the lock mechanism is released, one end of the cam portion 82 is pulled forward by the elastic restoring force of the spring portion 81. For this reason, the cam part 82 rotates, the other end 82b presses the printer main body 12 relatively, and pushes up the cover 14 part. In this case, the same effect as that of the first embodiment can be obtained.

  Moreover, in the said 1st Embodiment, although the operation member 20 which linearly moves by the button part 22 being pressed was used, other structures, such as a lever type, are also applicable.

  In addition, when implementing this invention, it cannot be overemphasized that the component of this invention, such as the specific shape of each structural member, can be variously changed without departing from the gist of the invention.

The side view which shows typically the inside in the closed state of the thermal printer which concerns on 1st Embodiment of this invention. The side view which shows typically the inside in the disengagement state of the thermal printer. The side view which shows typically the inside in the disengagement state of the thermal printer. The side view which shows typically the internal structure of the thermal printer concerning other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Thermal printer 11 ... Thermal paper 12 ... Printer main body 14 ... Cover 19 ... Engagement pin 20 ... Operation member 25 ... Platen roller 30 ... Engagement claw 33 ... Engagement recessed part 41 ... Thermal head 42 ... Heat sink 50 ... Link member 52 ... Elastic members

Claims (3)

The printer itself,
A cover attached to the printer body so as to be rotatable between a closed state and an open state;
A platen roller provided on the cover;
A thermal head provided in the printer main body, disposed opposite to the platen roller in a closed state, and pressing the platen roller;
A lock mechanism for engaging and releasing the printer body and the cover;
An interlocking member that interlocks the thermal head and the locking mechanism, and retracts the thermal head from the platen roller when the locking mechanism is disengaged;
Equipped with,
The lock mechanism is attached to the printer main body so as to be rotatable around a first rotation fulcrum between an engagement position and a release position, and the lock mechanism is arranged on one side around the first rotation fulcrum. An engaging claw having an engaging portion that engages with the cover portion, and the other side connected to the interlocking member;
The thermal head is fixed to a heat sink attached to the printer body so as to be rotatable around a second rotation fulcrum.
The heat sink is connected to the interlocking member on the opposite side of the pressing portion where the thermal head presses the platen roller around the second rotation fulcrum,
With the rotation of the lock mechanism from the engagement position to the release position, the heat sink is rotated via the interlocking member, whereby the thermal head is retracted from the platen roller at the pressing portion. Features a thermal printer. The interlocking member, the heat sink or the engagement claw, thermal printer according to claim 1, characterized by being mounted with a clearance. The engaging claw can be elastically deformed by a force of a certain level or more, and when the other end of the engaging claw is connected to the printer main body and the deformation force is released, the engaging claw is released by the elastic restoring force. The thermal printer according to claim 1 , further comprising an elastic member that restricts the inclination of the thermal printer.

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