JP2011046134A - Thermal printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal printer by which defects of a gear train due to foreign matters can be suppressed from occurring. <P>SOLUTION: The thermal printer (10) includes a frame (21), a printing roller (30) pivotally and detachably supported by the frame, a roller gear (40) connected to the printer roller and rotating integrally with the printing roller, a gear train (70) driving the roller gear, and a gear box (60) having an opening section (61) putting in and out the roller gear and housing the roller gear and the gear train, and the gear box has a partitioning section (81) partitioning the opening section and the gear train. It is possible to suppress the foreign matters coming into from the opening section of the gear box from attaching to the gear train by the partitioning section in the thermal printer. Accordingly, it is possible to suppress the defects of the gear train due to the foreign matters from occurring. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a thermal printer.

  Conventionally, there has been proposed a thermal printer that can easily remove the printing roller from the frame when the paper is replaced. The thermal printer includes a printing roller that is detachably supported on a frame, a roller gear that is connected to the printing roller and rotates integrally with the printing roller, a gear train that drives the roller gear, and a roller gear that is inserted into and removed from the frame. A gear box having an opening and accommodating a roller gear and a gear train.

  There exists patent document 1 as a prior art document relevant to this invention. Patent Document 1 is a document relating to a dust-proof device at a paper outlet for the purpose of preventing foreign matter from entering the thermal printer from the paper outlet.

Japanese Patent Laid-Open No. 5-4420

  When the print roller is removed from the frame in the thermal printer, the roller gear is also taken out from the opening of the gear box. As a result, foreign matter may enter the gear box from the opening and adhere to the gear train. If foreign matter adheres to the gear train, the gear train may be damaged. However, the technique according to Patent Document 1 cannot suppress the adhesion of foreign matter to the gear box. Therefore, the technique according to Patent Document 1 cannot suppress the occurrence of a gear train failure due to foreign matter.

  The present invention has been made under such circumstances, and an object of the present invention is to provide a thermal printer capable of suppressing the occurrence of a gear train failure due to foreign matter.

  The thermal printer according to the present invention includes a frame, a printing roller that is detachably supported by the frame, a roller gear that is connected to the printing roller and rotates integrally with the printing roller, and drives the roller gear. A partition having a gear train and an opening for taking in and out the roller gear, and housing the roller gear and the gear train, wherein the gear box separates the opening from the gear train. Is a thermal printer.

  According to the thermal printer of the present invention, it is possible to suppress the foreign matter that has entered from the opening of the gear box from adhering to the gear train by the partition portion. Thereby, it is possible to suppress the occurrence of a gear train failure due to foreign matter.

  In the above configuration, the partition portion may be a separate member from the gear box. According to this structure, compared with the case where a partition part is integrally molded with a gear box, manufacture of a partition part and a gear box becomes easy. The said structure WHEREIN: A film-like member may be sufficient as the said partition part. According to this configuration, the thermal printer can be reduced in weight.

  The said structure WHEREIN: The said gearbox may have at least one discharge port for discharging | emitting a foreign material. According to this configuration, the foreign matter that has entered the gear box can be discharged to the outside. Thereby, it is possible to suppress the occurrence of a gear train failure due to foreign matter.

  In the above configuration, the gear train may have water repellency. According to this structure, it can suppress that a foreign material adheres to a gear train. The said structure WHEREIN: The said flame | frame, the said gear train, and the said gear box may have rust prevention property. According to this structure, it can suppress that rust generate | occur | produces on a flame | frame, a gear train, and a gear box.

  ADVANTAGE OF THE INVENTION According to this invention, the thermal printer which can suppress generation | occurrence | production of the failure of the gear train by a foreign material can be provided.

1 is a schematic perspective view of a thermal printer according to Embodiment 1. FIG. FIG. 3 is an enlarged view of the vicinity of the gear box of the thermal printer according to the first embodiment. 1 is an exploded perspective view of a thermal printer according to Embodiment 1. FIG. FIG. 4A is a diagram for explaining the positional relationship between the gears constituting the gear train according to the first embodiment. FIG. 4B is a diagram for explaining the partition portion according to the first embodiment. It is the schematic diagram which looked at the partition member which concerns on Example 1 from the -Y direction side. 3 is an enlarged view of the vicinity of a gear box of a thermal printer according to Comparative Example 1 of Example 1. FIG. FIG. 7A is a diagram for explaining the gear box according to the second embodiment. FIG. 7B is a view for explaining a state in which the inside of the gear box according to the second embodiment is washed with a liquid.

  Hereinafter, modes for carrying out the present invention will be described.

  A thermal printer 10 according to the first embodiment will be described. FIG. 1 is a schematic perspective view of the thermal printer 10. The thermal printer 10 is a thermal printer that is used by being connected to a portable terminal device such as a cash register, an electronic notebook, a portable information terminal, or a cellular phone. The thermal printer 10 includes a thermal printer main body 20, a printing roller 30, a roller gear 40, a motor 50, and a gear box 60. In FIG. 1, the axial direction of the printing roller 30 is the X direction, the direction orthogonal to the X direction and the direction from the printing roller 30 toward the motor 50 is the Y direction, and the direction orthogonal to the X direction and the Y direction is the direction. Let it be the Z direction.

  FIG. 2 is an enlarged view of the vicinity of the gear box 60 of the thermal printer 10. In FIG. 2, the printing roller 30 and the roller gear 40 are not shown. As shown in FIGS. 1 and 2, the frame 21 of the thermal printer main body 20 is provided with two bearing portions 22 for pivotally supporting the printing roller 30 in a detachable manner.

  The print roller 30 is detachably supported by the bearing portion 22 of the frame 21. When the printing roller 30 is pivotally supported by the bearing portion 22, the holding portion 23 connected to the frame 21 is engaged with the printing roller 30 from the Z direction. As a result, the printing roller 30 is prevented from coming off from the bearing portion 22. When the print roller 30 is removed from the bearing portion 22, after the engagement of the holding portion 23 with the print roller 30 is released, the print roller 30 is moved relative to the thermal printer body 20 in the Z direction. Since the printing roller 30 is detachably supported on the bearing portion 22, the printing roller 30 can be easily detached from the bearing portion 22 when, for example, replacing paper.

  The printing roller 30 has a function as a paper feeding roller for continuously feeding printing paper by frictional force. The printing roller 30 also has a function as a back support roller for realizing stable printing on a sheet by the thermal head 24 which is a thermal printing unit. Specifically, the printing roller 30 includes an elastic body portion 31 having an elastic body such as rubber on the surface, and a shaft that is supported by the bearing portion 22 so as to protrude from both ends of the elastic body portion 31 in the X direction and the −X direction. Part 32. When the shaft portion 32 rotates, the elastic body portion 31 rotates integrally with the shaft portion 32 and continuously feeds the paper while being sandwiched between the thermal head 24.

  The roller gear 40 is connected to the end portion of the shaft portion 32 on the gear box 60 side. The roller gear 40 rotates integrally with the printing roller 30. The motor 50 is connected to the thermal printer main body 20. The motor 50 is a power source for driving the printing roller 30 to rotate.

  The gear box 60 is connected to the thermal printer main body 20. As shown in FIG. 2, the gear box 60 has an opening 61 in the Z direction for inserting and removing the roller gear 40. When taking out the printing roller 30 from the thermal printer main body 20, the roller gear 40 is taken out from the opening 61. When the printing roller 30 is attached to the thermal printer main body 20, the roller gear 40 is disposed in the gear box 60 from the opening 61.

  FIG. 3 is an exploded perspective view of the thermal printer 10. In FIG. 3, the printing roller 30 and the roller gear 40 are not shown. The gear box 60 includes a gear box main body 62 and a gear cover 63. When the gear cover 63 is assembled to the gear box body 62, a box-shaped gear box 60 is formed.

  The gear box 60 accommodates the gear train 70. The gear train 70 includes a first gear 71, a second gear 72, a third gear 73, a fourth gear 74, a fifth gear 75, and a sixth gear 76. The gear train 70 transmits the rotation of the motor 50 to the roller gear 40. Thereby, the roller gear 40 is driven. That is, the gear train 70 is a gear train for driving the roller gear 40.

  A partition member 80 is provided in the gear box 60. The partition member 80 includes a partition part 81 that separates the opening 61 and the gear train 70 and a support part 82 that supports the partition part 81. That is, the gear box 60 has a partition 81 that separates the opening 61 and the gear train 70. In this embodiment, the partition member 80 is a separate member from the gear box 60. The partition member 80 is disposed in the gear box 60 after the gear train 70 is assembled in the gear box 60. A convex portion 64 is provided on a surface in the −Z direction of the gear box body 62 (hereinafter, this surface is referred to as a bottom surface). The function of the convex portion 64 will be described later with reference to FIG.

  FIG. 4A is a diagram for explaining the positional relationship between the gears constituting the gear train 70. The motor gear 52 is connected to the motor shaft 51 of the motor 50 and rotates together with the motor shaft 51. In this embodiment, the axial direction of the motor shaft 51 is substantially parallel to the axial direction of the shaft portion 32 of the printing roller 30. The first gear 71 is a gear that meshes with the motor gear 52. The second gear 72 is a gear connected to the same shaft as the first gear 71 and rotating integrally with the first gear 71. The third gear 73 is a gear that meshes with the second gear 72. The fourth gear 74 is a gear that is connected to the same shaft as the third gear 73 and rotates integrally with the third gear 73. The fifth gear 75 is a gear that meshes with the fourth gear 74. The sixth gear 76 is connected to the same shaft as the fifth gear 75, rotates together with the fifth gear 75, and meshes with the roller gear 40.

  FIG. 4B is a diagram for explaining the partition portion 81. Specifically, FIG. 4B schematically illustrates a cross section of the gear box 60, the gear train 70, and the partitioning portion 81 cut along the line AA in FIG. 4A. In addition, in FIG.4 (b), illustration of the convex part 64 is abbreviate | omitted. The partition portion 81 separates the opening portion 61 and the gear train 70 in order to prevent foreign matter that has entered from the opening portion 61 from adhering to the gear train 70. In the present embodiment, the partition 81 separates the opening 61 from gears other than the sixth gear 76 and the fifth gear 75 among the gears constituting the gear train 70. In other words, the partition 81 separates the opening 61 from the first gear 71, the second gear 72, the third gear 73, and the fourth gear 74. The surface of the partition 81 on the roller gear 40 side has a curved surface shape so as not to contact the roller gear 40. The surface of the partition 81 on the fourth gear 74 side has a curved surface shape so as not to interfere with the fourth gear 74.

  FIG. 5 is a schematic view of the partition member 80 as viewed from the −Y direction side. In FIG. 5, the third gear 73, the fourth gear 74, the gear box main body 62, and the gear cover 63 are also illustrated together with the partition member 80. The support portion 82 is positioned by being sandwiched between the gear cover and the convex portion 64 provided on the bottom surface of the gear box main body 62. That is, the convex portion 64 has a function as a positioning member that positions the partition member 80. Moreover, the support part 82 is supporting the partition part 81 from the X direction. The partition part 81 is located in the Z direction of the fourth gear 74.

  In addition, it does not specifically limit as a material of the frame 21, the gear box 60, various gears, and the partition member 80, For example, a metal, resin, etc. can be used. Metals are preferred because they are stronger than resins. Resins are preferred from the viewpoints of weight saving and good processability than metals. In this embodiment, the material of the frame 21 and the gear box body 62 is zinc, and the material of the gear cover 63 is resin. The material of the motor gear 52 is brass, and the material of the roller gear 40, the gear train 70, and the partition member 80 is resin. Although it does not specifically limit as resin, For example, an engineering plastic can be used.

  FIG. 6 is an enlarged view of the vicinity of the gear box 110 of the thermal printer 100 according to the first comparative example of the first embodiment. The thermal printer 100 is different from the thermal printer 10 of FIG. 2 in that a gear box 110 is provided instead of the gear box 60. The gear box 110 is different from the thermal printer 10 in that the partition member 80 is not provided. Since the partition member 80 is not provided, in the thermal printer 100, the fourth gear 74, the fifth gear 75, and the sixth gear 76 are removed from the opening 61 after the print roller 30 is removed from the thermal printer main body 20. It becomes visible.

  When the thermal printer 100 enters the state shown in FIG. 6, foreign matter may enter the gear box 60 from the opening 61. As a result, the gear train 70 may be damaged such as damage. When the gear train 70 is made of resin, since the tooth strength is lower than that of the gear train 70 made of metal, the possibility of occurrence of a failure due to foreign matter is particularly increased. In particular, in the case of the thermal printer 100, the fourth gear 74, which is the farthest in the Y direction among the fourth gear 74 to the sixth gear 76, is the smallest gear in the gear train 70. The strength is the lowest in the gear train 70. Therefore, the fourth gear 74 is most likely to be damaged by foreign matter.

  On the other hand, according to the thermal printer 10 according to the present embodiment, since the opening 61 and the gear train 70 are separated by the partition 81, the foreign matter that has entered from the opening 61 enters the gear train 70. Adhesion is suppressed. Specifically, since the opening portion 61 and the first gear 71 to the fourth gear 74 are separated by the partition portion 81, the foreign matter that has entered from the opening portion 61 adheres to the first gear 71 to the fourth gear 74. Is suppressed. Thereby, it is possible to suppress the occurrence of a failure of the gear train 70 due to the foreign matter.

  Note that when the thermal printer 10 is used while connected to a portable terminal device, there is a risk that foreign matter may enter from the opening 61 as compared with a case where the thermal printer 10 is used while connected to a device other than the portable terminal device. Get higher. Further, when used by being connected to a portable terminal device, the gear train 70 is small, so the strength of the gear train 70 is low. Therefore, there is a high possibility that the gear train 70 will be damaged by foreign matter. Therefore, the thermal printer 10 is particularly suitable when used by being connected to a portable terminal device. The thermal printer 10 is particularly suitable when used by being connected to a portable terminal device used outdoors, among portable terminal devices. This is because when used outdoors, there is a high possibility that foreign matter will enter the gear box 60 from the opening 61 and there is a high possibility that hard foreign matter such as sand will enter. The thermal printer 10 has a high use environment in which hard foreign matter such as sand or the like is likely to enter from the opening 61, such as a portable terminal device for water meter reading, among portable terminal devices used outdoors. It is particularly suitable when used by being connected to a portable terminal device used below.

  In the present embodiment, the partition member 80 is a separate member from the gear box 60, but is not limited thereto. Even when the partition member 80 is integrally formed with the gear box 60, the partition portion 81 can suppress the occurrence of a failure of the gear train 70 due to foreign matter. However, since the partition member 80 is a separate member from the gear box 60, the manufacture of the partition member 80 and the gear box 60 is facilitated. Further, the partition member 80 can be detached from the gear box 60. Further, the partition member 80 can be made of a material different from that of the gear box 60.

  In the present embodiment, the partition 81 is a rigid body, but is not limited thereto. The partition part 81 may be a film-like member. Since the film-like member is lighter than a rigid body, the thermal printer 10 can be reduced in weight. The material of the film-like member is not particularly limited, but for example, a PET resin can be used.

  A thermal printer 10 according to a second embodiment will be described. The thermal printer 10 according to the present embodiment is different from the thermal printer 10 according to the first embodiment in that a gear box 60a is provided instead of the gear box 60. FIG. 7A is a view for explaining the gear box 60a. The gear box 60a differs from the gear box 60 shown in FIG. 4B in that it has at least one discharge port for discharging foreign matter. In the present embodiment, the gear box 60a has a discharge port 65 and a discharge port 66 on the bottom surface. The discharge port 66 is located in the Y direction from the discharge port 65. Further, the discharge port 65 is located on the −Z direction side of the opening 61, and the discharge port 66 is located on the −Z direction side of the motor gear 52.

  According to the thermal printer 10 according to the present embodiment, since the gear box 60a has at least one discharge port, foreign matter that has entered the gear box 60a can be discharged to the outside through the discharge port. As a result, it is possible to suppress the occurrence of a failure in the gear train 70 due to foreign matter. Further, by injecting liquid from the opening 61, foreign matter that has entered the gear box 60a can be washed away from the outlet. As a result, it is possible to suppress the occurrence of a failure in the gear train 70 due to foreign matter. In addition, since foreign matter that has entered the gear box 60a can be washed away simply by injecting liquid from the opening 61, removal of foreign matter is easier compared to, for example, removing the gear cover 63 and washing the inside of the gear box 60a. Can be done.

  FIG. 7B is a view for explaining a state in which the inside of the gear box 60a is washed with a liquid. In FIG. 7B, the roller gear 40 is taken out from the gear box 60a. For example, the liquid injected into the gear box 60a from the opening 61 cleans the gear train 70 and is discharged from the discharge port 65 and the discharge port 65 to the outside of the gear box 60a. As a result, the foreign matter that has entered the gear box 60a can be washed away with the liquid. Further, since the gear box 60a has the discharge port 65 and the discharge port 66, the gear box 60a can be entirely cleaned only by injecting the liquid into the gear box 60a from the opening 61 of the gear box 60a. it can.

  In addition, it does not specifically limit as a liquid, For example, water etc. can be used. The shape and size of the discharge port are not particularly limited as long as the shape and size can discharge the liquid in the gear box 60a to the outside. The number of discharge ports may be one or more. The larger the number of outlets, the higher the foreign matter discharging effect. Moreover, the discharge port may be formed in places other than a bottom face. However, it is possible to further suppress the liquid from remaining in the gear box 60a when the discharge port is formed at least on the bottom surface.

  The gear train 70 may have water repellency. According to this configuration, it is possible to prevent foreign matter from adhering to the gear train 70. In order to give the gear train 70 water repellency, for example, the gear train 70 may be coated with a water repellent material such as fluorine.

  Further, the frame 21, the gear train 70, and the gear box 60a may have rust prevention properties. According to this structure, it can suppress that rust generate | occur | produces on the flame | frame 21, the gear train 70, and the gear box 60a. For example, by constituting the frame 21, the gear train 70, and the gear box 60a with a rust preventive material such as resin, zinc, brass, and stainless steel, these members can have rust preventive properties.

  In the thermal printer 10 according to the first embodiment, the gear train 70 may have water repellency. In the thermal printer 10 according to the first embodiment, the frame 21, the gear train 70, and the gear box 60 may have rust prevention properties. As described above, the material of the frame 21 and the gear box body 62 is zinc, the material of the gear cover 63 is resin, and the material of the gear train 70 is resin. These materials are all antirust materials.

  The thermal printer 10 according to the present embodiment is also particularly suitable when used by being connected to a portable terminal device, as in the case of the first embodiment. Further, the thermal printer 10 according to the present embodiment is particularly suitable when used by being connected to a portable terminal device used outdoors, among portable terminal devices. Further, the thermal printer 10 according to the present embodiment has a hard foreign substance such as sand from the opening 61 as in a portable terminal device used outdoors, for example, a portable terminal device for water meter meter reading. It is particularly suitable when used by being connected to a portable terminal device used in a use environment where there is a high risk of entering.

  Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. It can be changed.

DESCRIPTION OF SYMBOLS 10 Thermal printer 20 Thermal printer main body 21 Frame 30 Printing roller 40 Roller gear 50 Motor 52 Motor gear 60 Gear box 61 Opening 62 Gear box main body 63 Gear cover 65 Discharge port 66 Discharge port 70 Gear train 80 Partition member 81 Partition unit 82 Support unit 100 Thermal Printer 110 Gearbox

Claims (6)

Frame,
A printing roller that is detachably supported by the frame;
A roller gear connected to the printing roller and rotating integrally with the printing roller;
A gear train for driving the roller gear;
And having an opening for taking in and out the roller gear, and a gear box for accommodating the roller gear and the gear train,
The thermal printer according to claim 1, wherein the gear box includes a partition portion that separates the opening from the gear train.   The thermal printer according to claim 1, wherein the partition portion is a separate member from the gear box.   The thermal printer according to claim 1, wherein the partition portion is a film-like member.   The thermal printer according to claim 1, wherein the gear box has at least one discharge port for discharging foreign matter.   The thermal printer according to claim 1, wherein the gear train has water repellency.   The thermal printer according to claim 1, wherein the frame, the gear train, and the gear box have rust prevention properties.

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