Printing units and handheld terminals

Abstract

To provide a printing unit having a motor fixing structure which enables reduction of the number of components.SOLUTION: A printing unit 6 includes: a platen roller which transports recording paper; a thermal head which makes pressure contact with an outer peripheral surface of the platen roller and makes prints on the recording paper; a motor 60 which rotates the platen roller around a predetermined axis; and a body frame 10 which rotatably supports the platen roller and to which the motor 60 is fixed with an adhesive.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a printing unit and a portable terminal. [Background technology]

[0002] A printing unit described in Patent Document 1 below has been known. In this printing unit, the platen roller is rotated with recording paper sandwiched between the platen roller and the thermal head, and the printing surface of the recording paper is heated by the heating elements of the thermal head while feeding the recording paper, causing the printing surface to develop color and perform printing. The platen roller has a gear at one end of its shaft. The platen roller rotates when the power of a motor attached to the frame of the printing unit is transmitted to the gear of the platen roller via a reduction gear. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-159482 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional printing unit, a flange with a screw hole is provided on the motor, and the motor is fixed to the frame by screwing the flange to the frame. Therefore, there is room for improvement in the conventional printing unit in terms of simplifying the structure for fixing the motor to the frame, reducing the number of parts, thereby reducing the unit weight, and reducing manufacturing costs.

[0005] SUMMARY OF THE PRESENT DISCLOSURE The present invention provides a printing unit having a motor fixing structure that can reduce the number of parts, and a portable terminal equipped with the printing unit. [Means for solving the problem]

[0006] The printing unit of the present invention includes a platen roller that transports recording paper, a thermal head that is pressed against the outer peripheral surface of the platen roller and prints on the recording paper, a motor that rotates the platen roller about a predetermined axis, and a frame that rotatably supports the platen roller and to which the motor is fixed with an adhesive.

[0007] According to the present invention, the motor can be fixed to the frame without using fastening members such as screws, etc. Therefore, it is possible to provide a print unit having a motor fixing structure with a reduced number of parts compared to conventional print units.

[0008] In the above printing unit, the adhesive may have a viscosity of 40 Pa·s or more and 110 Pa·s or less under an environment of a temperature of 23° C. and a humidity of 50%.

[0009] According to the present invention, it is possible to suppress the deterioration of application accuracy that may occur when a high-viscosity adhesive is used, and the leakage of adhesive that may occur when a low-viscosity adhesive is used, and therefore it is possible to provide a high-quality printing unit.

[0010] In the above printing unit, the adhesive may have a hardness of Shore A15 or more and Shore A58 or Shore D60 or less.

[0011] If the adhesive has a relatively high hardness, the impact on the motor, which is a heavy object, when the printing unit is dropped can cause cracks in the adhesive. According to the present invention, it is possible to prevent cracks from occurring in the adhesive due to the impact of the printing unit being dropped, and therefore it is possible to provide a highly durable printing unit.

[0012] In the printing unit, the adhesive film formation time may be 4 minutes or more and 25 minutes or less.

[0013] According to the present invention, by ensuring a coating time of 4 minutes or more, it is possible to apply adhesive to multiple frames or motors at once in the manufacturing process of the printing unit, and then bond the motors to the frames. Also, by setting the coating time to 25 minutes or less, the frame to which the motor is attached can be sent to the next process quickly. Therefore, it is possible to provide a printing unit with excellent productivity.

[0014] The above printing unit may comprise a support supported by the frame and having the thermal head fixed thereto, and a conductive member that contacts a housing of the motor and provides electrical conductivity between the housing and the support, and the frame and the conductive member may be formed so as to be able to be assembled to each other with the motor fixed to the frame by the adhesive.

[0015] In a configuration in which the frame and the conductive member must be assembled together before the motor is fixed to the frame, after the motor is attached to the frame via adhesive, the contact pressure of the conductive member on the motor before the adhesive hardens may displace the motor, causing it to become misaligned with respect to the frame. According to the present invention, the frame and the motor can be assembled after the adhesive hardens, which makes it possible to prevent the motor from becoming misaligned with the frame. Therefore, a high-quality printing unit can be provided.

[0016] In the above-mentioned printing unit, a contact space is formed between the frame and the motor, defined by the housing, in which the conductive member is disposed, and a communication portion is formed in the assembly consisting of the frame and the support body, linearly connecting the contact space with the outside and through which the conductive member is inserted.

[0017] According to the present invention, by linearly inserting the conductive member into the communicating portion from the outside of the assembly consisting of the frame and the support body, a part of the conductive member can be disposed in the contact space and brought into contact with the motor housing, and therefore the conductive member can be assembled to the frame with the motor fixed to the frame.

[0018] The printing unit may further include a fall-prevention portion that prevents the conductive member from falling off.

[0019] According to the present invention, it is possible to prevent the loss of electrical continuity between the motor housing and the thermal head support body due to the conductive member falling off, thereby improving the reliability of the printing unit.

[0020] The above-mentioned printing unit may further include an elastic member that biases the support toward the platen roller relative to the support, and the conductive member may be formed integrally with the elastic member.

[0021] According to the present invention, the number of parts can be reduced compared to when the conductive member is provided as a separate member from the elastic member. Also, by assembling the elastic member at a predetermined position, the conductive member can also be assembled to the frame. Therefore, compared to when the conductive member is provided as a separate member from the elastic member, an increase in the number of manufacturing steps can be suppressed. Therefore, an increase in manufacturing costs can be suppressed.

[0022] A portable terminal according to the present invention includes the above-mentioned printing unit.

[0023] According to the present invention, a printing unit having a motor fixing structure with a reduced number of parts is provided, thereby reducing weight and manufacturing costs, so that a lightweight and inexpensive portable terminal can be provided. Effect of the Invention

[0024] According to the present invention, it is possible to provide a printing unit and a portable terminal having a motor fixing structure that can reduce the number of parts. [Brief description of the drawings]

[0025] [Figure 1] FIG. 1 is a perspective view of a portable terminal according to an embodiment. [Diagram 2] FIG. 2 is a perspective view of a printing unit according to the first embodiment. [Diagram 3] FIG. 2 is an exploded perspective view of the printing unit according to the first embodiment. [Figure 4] FIG. 2 is a perspective view of a printing unit according to the first embodiment. [Diagram 5] FIG. 2 is a perspective view of a part of the printing unit of the first embodiment, seen from above and behind. [Figure 6] FIG. 2 is a perspective view of a part of the printing unit of the first embodiment, as viewed from below and behind. [Figure 7] FIG. 13 is a diagram showing the relationship between the hardness of an adhesive and the amount of decrease in peel resistance of the adhesive. [Figure 8] FIG. 11 is a perspective view of a printing unit according to a second embodiment. [Figure 9] FIG. 11 is an exploded perspective view of a printing unit according to a second embodiment. [Figure 10] FIG. 11 is a perspective view of a printing unit according to a second embodiment. [Figure 11] FIG. 11 is a perspective view of a part of a printing unit according to a second embodiment, as viewed from above and behind. [Figure 12] FIG. 11 is a perspective view of a part of a printing unit according to a second embodiment, as viewed from above and behind. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, components having the same or similar functions are denoted by the same reference numerals. In addition, duplicate descriptions of those components may be omitted.

[0027] (Mobile terminal) FIG. 1 is a perspective view of a portable terminal according to an embodiment. As shown in Fig. 1, the portable terminal 1 is configured to be capable of printing on recording paper P. The recording paper P is thermal paper that changes color when heat is applied, and is suitable for printing various labels, receipts, tickets, etc. The recording paper P is set in the portable terminal 1 in the form of roll paper R that is wound so as to have a hollow hole, and printing is performed on the portion of the roll paper R that is pulled out.

[0028] The portable terminal 1 includes a casing 3, a display unit 4, a control unit 5, and a printing unit 6. The casing 3 is formed in a hollow box shape from plastics such as ABS or a composite of ABS and polycarbonate, or from a metal material. The casing 3 has a rectangular parallelepiped main body 7 and a roll paper storage section 8 that is bent to one side in the thickness direction of the main body 7 at one end in the longitudinal direction of the main body 7. The print unit 6 is stored in one end in the longitudinal direction of the main body 7. An outlet 3a is formed in one end face in the longitudinal direction of the main body 7. The outlet 3a discharges the recording paper P printed through the print unit 6. The display section 4 is disposed on the main surface facing the other side in the thickness direction of the main body 7. The display section 4 is, for example, a liquid crystal panel, and is connected to the control section 5 to display various information. The roll paper R is stored in the roll paper storage section 8. The print unit 6 is a so-called thermal printer.

[0029] (Printing unit of the first embodiment) Figures 2 and 4 are perspective views of the print unit of the first embodiment, and Figure 3 is an exploded perspective view of the print unit of the first embodiment. As shown in Figures 2 to 4, the printing unit 6 includes a platen roller 50 having a driven gear 54, a motor 60 that rotates the platen roller 50 about a rotation axis O (a specified axis), a main body frame 10 (frame) that rotatably supports the platen roller 50 and to which the motor 60 is fixed, a first reduction gear 31 and a second reduction gear 32 that reduce the driving force of the motor 60 and transmit it to the driven gear 54, a thermal head 40 that is pressed against the outer peripheral surface of the platen roller 50, and a head support 45 that is supported by the main body frame 10 and to which the thermal head 40 is fixed.

[0030] 2, the printing unit 6 discharges the recording paper P that has passed between the platen roller 50 and the thermal head 40 in the direction indicated by the arrow A. In the following explanation of the printing unit 6, the direction along the arrow A is defined as the up-down direction L1, and the direction in which the arrow A points is defined as the upward direction. In addition, the direction perpendicular to the up-down direction L1 and coinciding with the width direction of the recording paper P is defined as the left-right direction L2. Furthermore, the direction perpendicular to the up-down direction L1 and the left-right direction L2 is defined as the front-rear direction L3, and the side of the platen roller 50 relative to the thermal head 40 in the front-rear direction L3 is defined as the front.

[0031] As shown in Fig. 3, the main body frame 10 is formed of a plate material such as polycarbonate resin containing glass fiber. The main body frame 10 is formed in a U-shape that opens forward when viewed from the up-down direction L1. Specifically, the main body frame 10 has a back plate portion 11 extending in the left-right direction L2, a first side wall portion 12 erected forward from an end portion on one side (left side) of the back plate portion 11 in the left-right direction L2, a second side wall portion 13 erected at least forward from an end portion on the other side (right side) of the back plate portion 11 in the left-right direction L2, and a paper guide portion 18 provided between the first side wall portion 12 and the second side wall portion 13.

[0032] As shown in FIG. 3 and FIG. 4, the back plate portion 11 is formed in a plate shape having a thickness in the front-rear direction L3. The back plate portion 11 has a thick plate portion 21 extending in the left-right direction L2 along the upper end edge, and a thin plate portion 22 adjacent to the thick plate portion 21 at a lower portion and extending in the left-right direction L2. The thick plate portion 21 is formed thicker in the front-rear direction L3 than the thin plate portion 22 by bulging rearward from the thin plate portion 22. The first side wall portion 12 is formed in a plate shape having a thickness in the left-right direction L2. A first roller insertion groove 14A cut downward is formed at the upper end edge of the first side wall portion 12. The second side wall portion 13 is formed in a plate shape having a thickness in the left-right direction L2. A second roller insertion groove 14B cut downward is formed at the upper end edge of the second side wall portion 13. The first roller insertion groove 14A and the second roller insertion groove 14B are formed to coincide with each other when viewed from the left-right direction L2. The platen roller 50 is detachably inserted into the first roller insertion groove 14A and the second roller insertion groove 14B.

[0033] 3, the paper guide portion 18 is formed in a columnar shape extending along the left-right direction L2. The paper guide portion 18 has an end portion on one side (left side) in the left-right direction L2 connected to the inner surface of the first side wall portion 12, and an end portion on the other side (right side) in the left-right direction L2 connected to the inner surface of the second side wall portion 13.

[0034] Fig. 5 is a perspective view of a part of the printing unit of the first embodiment, seen from above and behind. Note that in Fig. 5, the flexible printed circuit board 70 is omitted, and a part of the main body frame 10 is cut away. Fig. 5 also shows the motor 60 removed from the main body frame 10. As shown in Fig. 5, the back plate portion 11 is disposed behind the head support 45. A recess 23 for receiving an elastic member 47, which will be described later, is formed on the surface (front surface) of the back plate portion 11 facing the head support 45. The recess 23 is formed in the thick plate portion 21 of the back plate portion 11. The recess 23 is recessed rearward, extends in the up-down direction L1, and opens upward. The recesses 23 are provided in the same number as the elastic members 47 (three in this embodiment) (see Fig. 3).

[0035] The second side wall portion 13 includes a motor support portion 25. The motor support portion 25 is formed on the opposite side of the platen roller 50 across at least one of the back plate portion 11 and the paper guide portion 18 when viewed from the left-right direction L2 (see FIG. 3). In the illustrated example, the motor support portion 25 is formed on the opposite side of the platen roller 50 across the back plate portion 11 when viewed from the left-right direction L2. That is, the motor support portion 25 is formed behind the back plate portion 11 when viewed from the left-right direction L2. The surface of the motor support portion 25 facing inward in the left-right direction L2 is an adhesive surface to which the motor 60 is attached, and is formed in a flat surface perpendicular to the left-right direction L2. The motor support portion 25 is formed with a through hole 26 through which the output shaft 61 of the motor 60 is inserted. The through hole 26 is a circular hole centered on the output axis Q of the motor 60.

[0036] Fig. 6 is a perspective view of a part of the printing unit of the first embodiment as seen from below and behind. In Fig. 6, the flexible printed circuit board 70 is omitted, and components other than the motor 60 are shown cut along the left-right direction L2 and the front-rear direction L3. As shown in FIG. 6, the motor 60 is disposed on the inside in the left-right direction L2 with respect to the motor support part 25. As a result, the motor 60 is disposed on the opposite side to the platen roller 50 across the back plate part 11 (also see FIG. 5). The motor 60 generates torque around an output axis Q. The motor 60 is disposed so that the output axis Q is parallel to the rotation axis O of the platen roller 50. The motor 60 is disposed at a distance from the main body frame 10, except for the bonding surface of the motor support part 25. Furthermore, the entire motor 60 is disposed at a distance from the casing 3 of the mobile terminal 1.

[0037] The motor 60 includes a stator and a rotor (not shown), a housing 62 that houses the stator and the rotor, and an output shaft 61 that protrudes from the housing 62 along an output axis Q. The housing 62 includes a cylindrical portion 63 that extends in the left-right direction L2 and surrounds the stator from the outside in the circumferential direction, a first flange 64 that closes an opening of the cylindrical portion 63 on the motor support portion 25 side, and a second flange 65 that closes an opening of the cylindrical portion 63 on the opposite side to the first flange 64.

[0038] The cylindrical portion 63 is formed in a cylindrical shape centered on the output axis Q. The first flange 64 is formed in a disk shape with the thickness direction being the left-right direction L2. The first flange 64 is formed with a shaft hole 64a, a cylindrical boss 64b, and a notch 64c. The shaft hole 64a is formed in the center of the first flange 64. The shaft hole 64a is a circular hole centered on the output axis Q. The output shaft 61 is inserted into the shaft hole 64a. The cylindrical boss 64b protrudes from the opening edge of the shaft hole 64a toward the outside of the motor 60. The cylindrical boss 64b is formed in a cylindrical shape centered on the output axis Q. The cylindrical boss 64b is inserted into the through hole 26 of the motor support portion 25. The outer diameter of the cylindrical boss 64b is approximately the same as the inner diameter of the through hole 26 of the motor support portion 25. The outer peripheral surface of the cylindrical boss 64b is in close contact with the inner peripheral surface of the through hole 26 of the motor support portion 25 over the entire circumference. This fixes the motor 60 to the motor support portion 25 so as not to be displaced in the up-down direction L1 and the front-rear direction L3. The notch 64c is formed on the outer peripheral edge of the first flange 64. The second flange 65 is formed to have the same shape and size as the first flange 64. That is, the second flange 65 is formed with a shaft hole 65a, a cylindrical boss 65b, and a notch 65c (see FIG. 5). However, the shape of the second flange 65 is not particularly limited as long as it has a shaft hole through which the output shaft 61 is inserted.

[0039] The motor 60 is fixed to the motor support portion 25 by an adhesive. The adhesive is applied to the entire surfaces of the first flange 64 of the motor 60 and the motor support portion 25, which face each other. In this embodiment, the adhesive is applied to the entire main surface of the first flange 64 of the motor 60 facing the motor support portion 25. As a result, the adhesive fixes the motor 60 to the motor support portion 25 so that it cannot be displaced in the front-rear direction L3, the up-down direction L1, and the left-right direction L3. The adhesive is a one-component adhesive. The viscosity of the adhesive before curing is 40 Pa·s or more and 110 Pa·s or less under an environment of a temperature of 23° C. and a humidity of 50%. The hardness of the adhesive after curing is Shore A15 or more and Shore A60 or less. The coating formation time of the adhesive is 4 minutes or more and 25 minutes or less. However, the adhesive is not limited to an adhesive having the above characteristics.

[0040] The motor 60 is provided with a terminal 66 and a terminal seat 67. The terminal seat 67 protrudes from the outer circumferential surface of the cylindrical portion 63 of the housing 62 toward the outside of the motor 60. The terminal 66 protrudes from the terminal seat 67 toward the outside of the motor 60. A flexible printed circuit board 70 is connected to the terminal 66 (see FIG. 4). The motor 60 is electrically connected to the control unit 5 (see FIG. 1) via the flexible printed circuit board 70. The motor 60 is driven based on a signal from the control unit 5.

[0041] As shown in FIG. 3, a gear box portion 15 is formed on the outside of the second side wall portion 13. The gear box portion 15 has a peripheral wall portion 16 that stands from the periphery of the second side wall portion 13 toward the outside in the left-right direction L2. That is, the gear box portion 15 is formed by the second side wall portion 13 and the peripheral wall portion 16, and opens toward the outside in the left-right direction L2. The peripheral wall portion 16 opens upward when viewed from the left-right direction L2. A pair of locking recesses 17 that are recessed downward are formed in the peripheral wall portion 16. The pair of locking recesses 17 are formed on both the front and rear sides of the upper open portion of the peripheral wall portion 16. A gear cover 30 is engaged with the pair of locking recesses 17. The gear cover 30 covers the inside of the gear box portion 15 from the outside in the left-right direction L2.

[0042] A first reduction gear 31 and a second reduction gear 32 are rotatably assembled inside the gear box portion 15. The first reduction gear 31 meshes with an output shaft 61 of a motor 60. The second reduction gear 32 meshes with the first reduction gear 31.

[0043] The thermal head 40 prints on the recording paper P (see FIG. 2). The thermal head 40 is formed in a rectangular shape with the longitudinal direction being the left-right direction L2 when viewed from the front-rear direction L3. The thermal head 40 is arranged with its thickness direction coinciding with the front-rear direction L3. A large number of heating elements 41 are arranged on the head surface 40a of the thermal head 40 in the left-right direction L2.

[0044] The head surface 40a faces the printing surface of the recording paper P and is adapted to hold the recording paper P between itself and the outer peripheral surface of the platen roller 50. The thermal head 40 is connected to the control unit 5 (see FIG. 1) via a flexible printed circuit board 70, and a driver IC (not shown) mounted on the thermal head 40 controls the heat generation of the heating elements 41 based on signals from the control unit 5. The thermal head 40 prints various characters, figures, and the like on the printing surface of the recording paper P by controlling the heat generation of the heating elements 41. The thermal head 40 is fixed by being affixed to a head support 45.

[0045] The head support 45 is disposed between the first side wall 12 and the second side wall 13, in front of the back plate 11 and behind the paper guide 18. The head support 45 is made of a metal material. The head support 45 is a plate-shaped member with the left-right direction L2 as its longitudinal direction. The head support 45 is disposed with its thickness direction coinciding with the front-rear direction L3. The head support 45 fixes the thermal head 40 at its front surface.

[0046] A pair of stoppers 45a for restricting the rotation range of the head support 45 is formed at the upper end of the head support 45. The pair of stoppers 45a is formed in a substantially rectangular prism shape and extends outward in the left-right direction L2 of the head support 45. The pair of stoppers 45a is inserted into a rectangular hole 12a formed in the upper part of the first side wall 12 of the main body frame 10 and a rectangular hole 13a formed in the upper part of the second side wall 13. The stoppers 45a are configured to move in the holes 12a and 13a as the head support 45 rotates and to be able to come into contact with the inner wall surfaces of the holes 12a and 13a. The stoppers 45a restrict the rotation amount of the head support 45 by coming into contact with the inner wall surfaces of the holes 12a and 13a.

[0047] 5, a protrusion 46 is formed on the surface (rear surface) of the head support 45 facing the back plate portion 11. The protrusions 46 are provided in pairs at positions adjacent to the recesses 23 of the back plate portion 11. The pair of protrusions 46 are disposed with a gap in the left-right direction L2 so as to sandwich the center of the upper end opening of the recesses 23 when viewed from behind. The gap between the pair of protrusions 46 is smaller than the width of the elastic member 47 in the left-right direction L2.

[0048] An elastic member 47 is interposed between the head support 45 and the back plate portion 11. The elastic member 47 biases the head support 45 and the back plate portion 11 in a direction separating them from each other. That is, the elastic member 47 is configured to constantly press the head support 45 forward. In the illustrated example, the elastic member 47 is a conical spring whose diameter decreases from the front to the rear. The rear end of the elastic member 47 is inserted into the recess 23 of the back plate portion 11. The front end of the elastic member 47 abuts against the rear surface of the head support 45, and its upward movement is restricted by the protrusion 46. A plurality of elastic members 47 (three in this embodiment) are arranged at intervals in the left-right direction L2 (see FIG. 3).

[0049] 2, the platen roller 50 is disposed opposite the thermal head 40 with its rotation axis O aligned with the left-right direction L2. The platen roller 50 rotates about the rotation axis O with the recording paper P sandwiched between it and the thermal head 40, thereby feeding the recording paper P in the direction indicated by the arrow A.

[0050] 3, the platen roller 50 has a roller shaft 51, a roller body 52 fitted onto the roller shaft 51, and a pair of bearings 53 attached to both ends of the roller shaft 51. The roller shaft 51 is formed to be slightly longer than the distance between the first side wall portion 12 and the second side wall portion 13 of the main body frame 10. The roller body 52 is made of, for example, rubber, and is uniformly disposed over the entire roller shaft 51 except for both ends in the left-right direction L2.

[0051] 2 and 3, the platen roller 50 has a pair of bearings 53 attached to both ends, which are inserted into the first roller insertion groove 14A and the second roller insertion groove 14B of the main body frame 10. The bearings 53 are held in the first roller insertion groove 14A and the second roller insertion groove 14B by a locking spring 19 supported by the main body frame 10. This allows the platen roller 50 to be rotatably held relative to the main body frame 10. The platen roller 50 can be attached to and detached from the main body frame 10 by elastically deforming the locking spring 19 to move the bearings 53 forward and backward into the first roller insertion groove 14A and the second roller insertion groove 14B. When the platen roller 50 is inserted into the first roller insertion groove 14A and the second roller insertion groove 14B, the roller body 52 is arranged to contact the thermal head 40 with the recording paper P pulled out from the roll paper R (see FIG. 1) sandwiched therebetween.

[0052] As shown in Fig. 3, a driven gear 54 is fixed to the end of the platen roller 50 on the other side (right side) in the left-right direction L2. The driven gear 54 is assembled to the upper part of the gear box unit 15 when the platen roller 50 is held by the first side wall portion 12 and the second side wall portion 13. The driven gear 54 meshes with the second reduction gear 32. As a result, the rotational driving force from the motor 60 is transmitted to the driven gear 54 via the first reduction gear 31 and the second reduction gear 32. The platen roller 50 rotates while being held by the first side wall portion 12 and the second side wall portion 13, and can feed out the recording paper P (see Fig. 2).

[0053] 5, the printing unit 6 further includes a conductive member 80. The conductive member 80 contacts the housing 62 of the motor 60, and electrically connects the housing 62 and the head support 45. A part of the conductive member 80 is disposed in a contact space S between the motor 60 and the main body frame 10. The contact space S is formed in front of the housing 62 of the motor 60 and behind the back plate portion 11 of the main body frame 10. The contact space S is defined by the housing 62 of the motor 60 from the rear, and is defined by the rear surface of the thin plate portion 22 of the back plate portion 11 from the front.

[0054] The contact space S is linearly connected to the outside of the assembly consisting of the main body frame 10 and the head support 45 through the communication part 27. The communication part 27 linearly penetrates the thick plate part 21 of the back plate part 11 along the up-down direction L1 and opens to the outside of the assembly consisting of the main body frame 10 and the head support 45. An upper part of the communication part 27 coincides with the recess 23. As a result, the contact space S is connected to the recess 23 through a part of the communication part 27. An upper part of the communication part 27 is formed between the thick plate part 21 of the back plate part 11 and the head support 45, and a lower part of the communication part 27 is formed in the thick plate part 21 of the back plate part 11.

[0055] The conductive member 80 is made of a material having electrical conductivity. In this embodiment, the conductive member 80 is made of a metal wire. The conductive member 80 is electrically connected to the head support 45. The conductive member 80 is mechanically connected to one elastic member 47, and is electrically connected to the head support 45 through the elastic member 47. In this embodiment, the conductive member 80 is integrated with the elastic member 47. The conductive member 80 is pressed against the housing 62 of the motor 60 by a restoring force caused by elastic deformation in the contact space S. The conductive member 80 extends from the contact space S to the communication portion 27 toward the outside of the assembly consisting of the main body frame 10 and the head support 45. The conductive member 80 is connected to the elastic member 47 at the upper portion (recess 23) of the communication portion 27.

[0056] A specific shape of the conductive member 80 will be described in detail. The conductive member 80 includes a base portion 81 arranged from the communicating portion 27 to the contact space S, and a contact portion 82 that contacts the housing 62 of the motor 60 in the contact space S. The base portion 81 extends downward from the rear end portion of the elastic member 47. The contact portion 82 extends upward and rearward from a lower end portion 81l of the base portion 81. An upper end portion 82u of the contact portion 82 is located rearward and lower than the opening of the communicating portion 27 on the contact space S side. As a result, the conductive member 80 is prevented from falling off the communicating portion 27 by the contact portion 82 being engaged with the opening edge 27a on the contact space S side of the communicating portion 27. In addition, the conductive member 80 is prevented from falling off the communicating portion 27 because the elastic member 47 mechanically connected to the conductive member 80 is prevented from moving upward by the convex portion 46 of the head support 45.

[0057] A method for assembling the conductive member 80 will now be described. The conductive member 80 is formed so as to be mountable at a predetermined position on the main body frame 10 in a state in which the motor 60 is fixed to the main body frame 10 by an adhesive. Specifically, the lower end 81l of the base 81 of the conductive member 80 is inserted into the communicating portion 27 from above, and the conductive member 80 passes through the communicating portion 27. At this time, the conductive member 80 is bent so that the upper end 82u of the contact portion 82 approaches the base 81. As a result, the outer shape of the conductive member 80 is reduced when viewed from the extending direction of the communicating portion 27 (the up-down direction L1), and the contact portion 82 can pass through the communicating portion 27 together with the base 81. When the contact portion 82 passes through the communicating portion 27, the conductive member 80 is restored to its original state, and the contact portion 82 is displaced backward to come into contact with the housing 62 of the motor 60.

[0058] When the conductive member 80 is inserted into the communicating portion 27, the elastic member 47 connected to the conductive member 80 is inserted into the recess 23. Specifically, the elastic member 47 is inserted from above into the recess 23 in a compressed state so as to overcome the protrusion 46. After the elastic member 47 overcomes the protrusion 46, it engages with the protrusion 46 from below. In this manner, the elastic member 47 and the conductive member 80 can be assembled in place.

[0059] As described above, in the printing unit 6 of this embodiment, the motor 60 is fixed to the main body frame 10 by adhesive. With this configuration, the motor 60 can be fixed to the main body frame 10 without using fastening members such as screws. Therefore, it is possible to provide a printing unit 6 having a motor fixing structure with a reduced number of parts compared to conventional printing units.

[0060] The viscosity of the adhesive is 40 Pa·s or more and 110 Pa·s or less under an environment of a temperature of 23°C and a humidity of 50%. This configuration can suppress the decrease in application accuracy that can occur when a high-viscosity adhesive is used, and the leakage of adhesive that can occur when a low-viscosity adhesive is used. Therefore, a high-quality printing unit 6 can be provided.

[0061] However, if the hardness of the adhesive is relatively high, the adhesive may crack due to the impact acting on the motor 60, which is a heavy object, when the printing unit 6 is dropped. 7 is a diagram showing the relationship between the hardness of the adhesive and the decrease in peel resistance of the adhesive. The decrease in peel resistance is the decrease in the force required to peel the motor 60 from the motor support part 25 before and after the printing unit 6 is dropped and a drop impact of 1000 G is applied to the motor 60. As shown in FIG. 7, if the hardness of the adhesive is Shore A15 or more and Shore A58 or Shore D60 or less, even if a drop impact of 1000G is applied to the motor 60, the peel resistance of the adhesive does not decrease. Note that Shore D60 is sufficiently harder than Shore A58. Therefore, according to this embodiment, it is possible to suppress the occurrence of cracks in the adhesive due to the drop impact of the printing unit 6. Therefore, it is possible to provide a printing unit 6 with high durability.

[0062] The time required for forming the adhesive film is 4 minutes or more and 25 minutes or less. With this configuration, by ensuring a film formation time of 4 minutes or more, the adhesive can be applied to a plurality of body frames 10 or motors 60 collectively in the manufacturing process of the printing unit 6, and then the motors 60 can be bonded to the body frames 10. Furthermore, by setting the film formation time to 25 minutes or less, the body frames 10 to which the motors 60 are bonded can be sent promptly to the next process. Therefore, a printing unit 6 with excellent productivity can be provided.

[0063] The main body frame 10 and the conductive member 80 are formed so as to be able to be assembled to each other in a state in which the motor 60 is fixed to the main body frame 10 with an adhesive. In a configuration in which the main body frame and the conductive member must be assembled to each other before the motor 60 is fixed to the main body frame, after the motor 60 is attached to the main body frame via the adhesive, the motor 60 may be displaced by the contact pressure of the conductive member on the motor 60 before the adhesive hardens, and the motor 60 may be misaligned with respect to the main body frame. According to this embodiment, the main body frame 10 and the motor 60 can be assembled after the adhesive hardens, so that misalignment of the motor 60 with respect to the main body frame 10 can be suppressed. Therefore, a high-quality printing unit 6 can be provided.

[0064] Between the main body frame 10 and the motor 60, a contact space S is formed, which is defined by the housing 62 of the motor 60 and in which the conductive member 80 is disposed. In the assembly consisting of the main body frame 10 and the head support 45 of the thermal head 40, a communication section 27 is formed, through which the conductive member 80 is inserted, and which linearly connects the contact space S to the outside. According to this configuration, by linearly inserting the conductive member 80 into the communication section 27 from the outside of the assembly consisting of the main body frame 10 and the head support 45, a part of the conductive member 80 can be disposed in the contact space S and contact the housing 62 of the motor 60. Therefore, the conductive member 80 can be assembled to the main body frame 10 with the motor 60 fixed to the main body frame 10.

[0065] The printing unit 6 includes an opening edge 27a of the communication portion 27 that prevents the conductive member 80 from falling off, and a protrusion 46. This configuration can prevent the conductive member 80 from falling off and thereby prevent the electrical connection between the housing 62 of the motor 60 and the head support 45 of the thermal head 40 from being lost. This improves the reliability of the printing unit 6.

[0066] The printing unit 6 includes an elastic member 47 that biases the head support 45 toward the platen roller 50 relative to the head support 45. The conductive member 80 is formed integrally with the elastic member 47. With this configuration, the number of parts can be reduced compared to when the conductive member is provided as a separate member from the elastic member. Also, by assembling the elastic member 47 at a predetermined position, the conductive member 80 can also be assembled to the main body frame 10. Therefore, an increase in the number of manufacturing steps can be suppressed compared to when the conductive member is provided as a separate member from the elastic member. Therefore, an increase in manufacturing costs can be suppressed.

[0067] Furthermore, the portable terminal 1 of this embodiment is equipped with a printing unit 6 that has a motor fixing structure with a reduced number of parts, thereby reducing its weight and manufacturing costs, making it a lightweight and inexpensive portable terminal.

[0068] (Printing unit according to the second embodiment) Figures 8 and 10 are perspective views of the print unit of the second embodiment, and Figure 9 is an exploded perspective view of the print unit of the second embodiment. The second embodiment differs from the first embodiment in that a conductive member 90 is disposed along the outer surface of the back plate portion 11. Note that the configuration other than that described below is similar to that of the first embodiment.

[0069] As shown in Figs. 8 to 10, the second side wall 13 of the main body frame 10 has a motor support part 25A instead of the motor support part 25 of the first embodiment. The motor support part 25A is formed on the opposite side of the platen roller 50 with the paper guide part 18 sandwiched between them when viewed from the left-right direction L2. The motor support part 25A is formed below the back plate part 11 and the paper guide part 18 when viewed from the left-right direction L2. A motor 60 is fixed to a surface of the motor support part 25A facing inward in the left-right direction L2. As a result, the motor 60 is disposed below the back plate part 11 on the opposite side of the platen roller 50 with the paper guide part 18 sandwiched between them. The motor 60 is fixed to the motor support part 25A with an adhesive.

[0070] Fig. 11 is a perspective view of a part of the printing unit of the second embodiment as seen from above and behind. Fig. 12 is a perspective view of a part of the printing unit of the second embodiment as seen from above and behind. In Fig. 12, some of the components are shown cut along the up-down direction L1 and the front-rear direction L3. 11 and 12, a slit 28 is formed in the back plate portion 11. The slit 28 penetrates the back plate portion 11 in the front-rear direction L3 and extends upward from a position facing the housing 62 of the motor 60 at the lower end edge of the back plate portion 11. The slit 28 is open toward the housing 62 of the motor 60.

[0071] The printing unit 6A includes a conductive member 90 instead of the conductive member 80. The conductive member 90 is mechanically connected to one elastic member 47 and electrically connected to the head support 45 through the elastic member 47. In this embodiment, the conductive member 90 is integrated with the elastic member 47. The conductive member 90 is formed so as to be mountable to a predetermined position of the main body frame 10 in a state in which the motor 60 is fixed to the main body frame 10 by an adhesive. The conductive member 90 is prevented from falling off from a predetermined mounting position of the main body frame 10 because the elastic member 47 mechanically connected to the conductive member 90 is prevented from moving upward by the convex portion 46 of the head support 45.

[0072] The conductive member 90 includes a contact portion 91 disposed in the slit 28, and a connecting portion 92 disposed along the outer surface of the back plate portion 11 and connecting the contact portion 91 and the elastic member 47. The connecting portion 92 is disposed along the rear surface of the back plate portion 11. The connecting portion 92 is mechanically connected to the elastic member 47 in the vicinity of the upper end opening of the recess 23 of the back plate portion 11. The connecting portion 92 extends leftward from the connection portion with the elastic member 47 along the upper end edge of the back plate portion 11, and then extends downward toward the slit 28. The contact portion 91 is connected to the lower end of the connecting portion 92. The contact portion 91 extends in a direction perpendicular to the left-right direction L2 throughout the entirety. The contact portion 91 extends downward from the lower end of the connecting portion 92 while meandering in the front-rear direction L3, and is in contact with the housing 62 of the motor 60. This allows the contact portion 91 to be elastically deformable in the up-down direction L1, and by being disposed in the slit 28 in a contracted state, the contact portion 91 is in pressure contact with the housing 62 of the motor 60. As shown in Fig. 12, the contact portion 91 extends so as to straddle the head support 45 when viewed from the outside in the left-right direction L2 behind the back plate portion 11. The contact portion 91 is capable of coming into contact with the head support 45 from the outside in the left-right direction L2, and regulates the displacement of the head support 45.

[0073] As described above, in the printing unit 6A of this embodiment, like the printing unit 6 of the first embodiment, the motor 60 is fixed to the main body frame 10 by adhesive, and therefore the same effects as those of the first embodiment are achieved.

[0074] The printing unit 6A also includes a protrusion 46 that prevents the conductive member 90 from falling off. This configuration can prevent the conductive member 90 from falling off and thereby prevent the electrical continuity between the housing 62 of the motor 60 and the head support 45 of the thermal head 40 from being lost. This can improve the reliability of the printing unit 6A.

[0075] The present invention is not limited to the above-described embodiment explained with reference to the drawings, and various modifications are possible within the technical scope of the present invention. For example, in the above embodiment, the bonding surfaces of the motor support part 25 and the motor 60 are flat. However, at least one of the bonding surfaces of the motor support part and the motor may have an uneven shape such as a groove. This can improve the bonding strength between the motor support part and the motor.

[0076] In addition, the components in the above-described embodiments can be replaced with well-known components as appropriate without departing from the spirit of the present invention. [Explanation of symbols]

[0077] REFERENCE SIGNS LIST 1... portable terminal 6, 6A... printing unit 10... main body frame (frame) 27... communication portion 27a... opening edge (fall-off prevention portion) 40... thermal head 46... protruding portion (fall-off prevention portion) 47... elastic member 50... platen roller 60... motor 62... housing 80, 90... conductive member P... recording paper S... contact space

Claims

1. A platen roller for transporting recording paper; a thermal head that is pressed against an outer peripheral surface of the platen roller and prints on the recording paper; a motor for rotating the platen roller about a predetermined axis; a frame that rotatably supports the platen roller and to which the motor is fixed by an adhesive; A printing unit comprising:

2. The viscosity of the adhesive is 40 Pa·s or more and 110 Pa·s or less under an environment of a temperature of 23° C. and a humidity of 50%. The printing unit according to claim 1 .

3. The hardness of the adhesive is Shore A15 or more and Shore A58 or Shore D60 or less. The printing unit according to claim 1 or 2.

4. The adhesive coating time is 4 minutes or more and 25 minutes or less. The printing unit according to any one of claims 1 to 3.

5. a support supported by the frame and to which the thermal head is fixed; a conductive member that contacts a housing of the motor and electrically connects the housing and the support; Equipped with the frame and the conductive member are formed so as to be able to be assembled to each other in a state in which the motor is fixed to the frame by the adhesive. The printing unit according to any one of claims 1 to 4.

6. a contact space defined by the housing and in which the conductive member is disposed is formed between the frame and the motor; a communication portion, through which the conductive member is inserted, is formed in an assembly consisting of the frame and the support body, the communication portion linearly communicating the contact space with the outside; The printing unit according to claim 5.

7. A fall-prevention portion is provided to prevent the conductive member from falling off. The printing unit according to claim 5 or 6.

8. an elastic member that biases the support toward the platen roller relative to the support, The conductive member is integrally formed with the elastic member. The printing unit according to any one of claims 5 to 7.

9. A portable terminal comprising the printing unit according to any one of claims 1 to 8.

Images