Thermal printer

Abstract

The utility model discloses a thermal printer, comprising: a main frame on which a thermal head assembly is mounted; a compression roller is mounted on the compression roller frame, and the compression roller frame can drive the compression roller to be close to or away from the thermosensitive head assembly; wherein the compression roller frame is provided with a shaft sleeve joint groove, the end parts of the two sides of the compression roller are supported in the shaft sleeve joint groove through shaft sleeve pieces, and the shaft sleeve pieces are limited by groove openings of the shaft sleeve joint groove and cannot be separated from the shaft sleeve joint groove in the radial direction; the main frame is provided with an anti-movement component, and the anti-movement component is constructed to be capable of applying radial pressing force to a shaft sleeve piece on at least one end of a pressing roller close to the thermosensitive head assembly so that the shaft sleeve piece can be tightly attached to the groove wall of the shaft sleeve joint groove. According to the technical scheme, the problem that in the prior art, the shaft sleeve part moves during printing, and transverse stripe printing defects are generated can be solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to printing material technology, specifically, a kind of thermal printer. BACKGROUND

[0002] Common thermal printer includes main frame, thermal head assembly installed in main frame, compression roller frame, compression roller installed on compression roller frame.The both ends of compression roller are rotatably supported on compression roller frame by shaft sleeve, because of manufacturing error, and in order to facilitate the production assembly of compression roller, assembly gap is generally left between shaft sleeve and compression roller frame.Assembly gap causes that shaft sleeve and compression roller frame have certain shaking space, horizontal stripe is generated on printing paper when printing, which affects printing quality.Therefore, the present application is proposed. SUMMARY

[0003] The utility model solves the technical problem to provide a kind of thermal printer to solve the existing thermal printer, the assembly gap between shaft sleeve and compression roller frame affects printing quality problem.

[0004] In order to achieve the above purpose, the technical scheme adopted by the utility model is as follows: a kind of thermal printer, comprising: main frame, thermal head assembly is installed on it;Compression roller frame, compression roller is installed on it, and the compression roller can be driven to be close to or away from thermal head assembly;Wherein, the compression roller frame has shaft sleeve joint groove, the both sides end of the compression roller is supported in the shaft sleeve joint groove by shaft sleeve piece, and the shaft sleeve piece is limited by the slot of the shaft sleeve joint groove and cannot be separated from the shaft sleeve joint groove along the radial direction;Anti-movement member is installed on the main frame, which is configured to be able to exert radial compression force on the shaft sleeve piece of at least one end of the compression roller close to the thermal head assembly, so that the shaft sleeve piece is close to the groove wall of the shaft sleeve joint groove.

[0005] Preferably, the anti-movement member has: a pivot portion pivoted to the main frame;Pressure application portion, which is configured to be able to pass through the slot to exert radial compression force on the shaft sleeve piece;Locking portion, which is configured to be able to be fixed to the main frame by fastener;Controlled portion, which is configured to be able to drive the pressure application portion to rotate around the pivot portion after the fastener is removed.

[0006] Preferably, the locking portion is a through hole, the main frame has an engagement hole matched with the through hole, the size of the through hole is greater than the size of the engagement hole, and the fastener is a fastening screw.

[0007] Preferably, the pressure surface of the shaft sleeve piece matched with the anti-movement member is a plane.

[0008] Preferably, the pressing roller frame is rotatably mounted on the main frame, and a pushing member is rotatably mounted on the main frame, and the pushing member drives the pressing roller frame to rotate in the positive direction relative to the main frame to move the pressing roller away from the thermal head assembly, and the rotation axis of the pressing roller frame coincides with the rotation axis of the pushing member.

[0009] Preferably, a reset mechanism is mounted between the pushing member and the pressing roller frame to drive the pushing member to rotate in the reverse direction relative to the main frame.

[0010] Preferably, the reset mechanism comprises a sliding member in sliding cooperation with the pressing roller frame and driven by the pushing member to slide relative to the pressing roller frame in a set direction when the pushing member rotates in the positive direction, and an elastic member engaged between the sliding member and the pressing roller frame and elastically deformed when the sliding member slides relative to the pressing roller frame in the set direction.

[0011] Preferably, the elastic member is engaged with the pressing roller frame by a pin, and the pin passes through the sliding member and defines the range of the sliding member relative to the pressing roller frame.

[0012] Preferably, the pressing roller frame and the pushing member are rotatably mounted on the main frame by the same shaft, and the shaft passes through the sliding member and defines the range of the sliding member relative to the pressing roller frame.

[0013] With the above technical scheme, the present application has the following beneficial effects: the technical scheme of the present application installs an anti-channeling member on the main frame, and the anti-channeling member can apply a radial pressing force to the shaft sleeve at least at one end of the pressing roller close to the thermal head assembly, so that the shaft sleeve is tightly attached to the groove wall of the shaft sleeve engaging groove, thereby eliminating the gap between the shaft sleeve and the pressing roller frame and avoiding the channeling of the shaft sleeve in the prior art to cause the problem of horizontal stripe printing defects. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the drawings of the embodiments will be briefly introduced below, and obviously, the drawings described below only relate to some embodiments of the present application, but not limit the present application.

[0015] Figure 1 and Figure 2 respectively show the schematic diagram of the thermal printer of an embodiment from different perspectives;

[0016] Figure 3 show the first exploded view of the thermal printer of an embodiment;

[0017] Figure 4 show the second exploded view of the thermal printer of an embodiment; respectively show the schematic diagram of the thermal printer of an embodiment from different perspectives;

[0018] Figure 5 A second exploded view of the thermal printer of an embodiment is shown;

[0019] Figure 6 A first exploded view of the thermal printer of an embodiment is shown; Figure 7 A second exploded view of the thermal printer of an embodiment is shown, with the platen roller frame in different states of movement relative to the main frame;

[0020] Figure 8 A second exploded view of the thermal printer of an embodiment is shown, with the platen roller and platen roller frame changing from a disassembled state to an assembled state;

[0021] Figure 9 A second exploded view of the thermal printer of an embodiment is shown, with the platen roller and platen roller frame changing from a disassembled state to an assembled state; Figure 10 A second exploded view of the thermal printer of an embodiment is shown, with the platen roller and platen roller frame changing from a disassembled state to an assembled state;

[0022] Figure 11 A first exploded view corresponding to Figure 9 , Figure 10 is shown;

[0023] Figure 12 A second exploded view corresponding to Figure 9 , Figure 10 is shown;

[0024] Figure 13 A third exploded view corresponding to Figure 9 , Figure 10 is shown;

[0025] Figure 14 A schematic view of the slide is shown;

[0026] Figure 15 A schematic view of the pusher is shown.

[0027] Reference signs:

[0028] Main frame 1, main frame body 1A, auxiliary frame body 1B, thermal head assembly 2, platen roller mechanism 3, platen roller frame 3A, platen roller 3B, shaft sleeve 3C, pusher Q, slide 3D, elastic member 3E, pin 3F, anti-creep member G, paper guide member 4, drive mechanism 5. DETAILED DESCRIPTION

[0029] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, further detailed description will be made to the present application with reference to the drawings. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0030] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the features in the following embodiments can be combined with each other.

[0031] Combination Figures 1 to 15 In one embodiment, the thermal printer of this application includes a main frame 1, a thermal head assembly 2, a pressure roller mechanism 3, an anti-slip component G, a paper guide component 4, and a drive mechanism 5. The following description, in conjunction with the figures, will further illustrate the invention. For ease of understanding, the X direction in the figures is defined as the direction from right to left, the Y direction as the direction from back to front, and the Z direction as the direction from bottom to top.

[0032] [Main Framework] Combined Figure 3 The main frame 1 includes a main frame 1A and an auxiliary frame 1B, with the auxiliary frame 1B mounted on the main frame 1A. The main frame 1A has a mounting portion 1C for mounting the thermal head assembly 2. The mounting portion 1C includes a first slide groove 1C-1 arranged in the front-rear direction Y and a second slide groove 1C-2 arranged in the vertical direction Z, the first slide groove 1C-1 and the second slide groove 1C-2 being connected. The main frame 1A also has a mating portion 1D for engaging the shaft assembly 3C; in this embodiment, the mating portion 1D is an arc-shaped groove.

[0033] [Thermal Head Assembly] The left and right sides of the thermal head assembly 2 are swayably mounted on the main frame 1A of the main frame 1, combined with... Figure 3 The thermal head assembly 2 has joints 2A on both its left and right sides. Through these joints 2A, it slides from the first slide groove 1C-1 into the second slide groove 1C-2, thus mounting the thermal head assembly 2 onto the main frame 1A. Figures 2 to 4 A force-applying spring P is provided between the thermal head assembly 2 and the auxiliary frame 1B to apply a force to the thermal head assembly 2 to the pressure roller 3B of the pressure roller mechanism 3.

[0034]

Pressure Roller Mechanism

[0035] The pressure roller frame 3A is rotatably mounted on the main frame 1. In this embodiment, the pressure roller frame 3A is rotatably mounted on the main frame 1A of the main frame 1 via a shaft support N. The left and right sides of the pressure roller frame 3A have bushing engagement grooves K. The left and right ends of the pressure roller 3B are supported in the bushing engagement grooves K by shaft fittings 3C, and are engaged... Figure 8 The shaft assembly 3C is mounted axially L into the bushing engagement groove K. The size of the groove opening K1 of the bushing engagement groove K is smaller than the size of the end of the pressure roller 3B. The shaft assembly 3C is restricted by the groove opening K1 of the bushing engagement groove K and cannot disengage radially R from the bushing engagement groove K. In this manner, the pressure roller 3B is mounted on the pressure roller frame 3A. Figure 8The surface of the shaft assembly 3C facing the slot K1 is the pressure-bearing surface 3C-1 that mates with the anti-movement component G. This pressure-bearing surface 3C-1 is planar, and its planar structure increases the force-bearing area, allowing the shaft assembly 3C to fit more tightly against the groove wall of the shaft sleeve engagement slot. Figure 6 and Figure 7 The pressure roller frame 3A can drive the pressure roller 3B to approach or move away from the thermal head assembly 2. Due to manufacturing errors and assembly requirements, a gap will remain between the bushing engagement groove K and the shaft assembly 3C.

[0036] The pusher Q is used to move the pressure roller frame 3A. In this embodiment, the pusher Q is also rotatably mounted on the main frame 1 via a shaft N, meaning the rotation axis of the pressure roller frame 3A and the rotation axis of the pusher Q coincide. By rotatably mounting the pressure roller frame 3A and the pusher Q to the main frame 1 via the same shaft N, the overall structure of the printer becomes more compact. Figure 6 and Figure 15 The pushing component Q has a force-receiving part Q1, a first pushing part Q2, a second pushing part Q3, and a confined position part Q4. For example... Figure 6 When the force-bearing part Q1 is subjected to force, the pushing part Q rotates forward relative to the main frame 1, and the first pushing part Q2 contacts the force-bearing part T11 of the pressure roller frame 3A, causing the pressure roller frame 3A to rotate forward, thereby causing the pressure roller 3B to move away from the thermal head assembly 2; correspondingly, when the pushing part Q rotates in reverse relative to the main frame 1, the restricted part Q4 rotates to contact the obstruction part T2 on the main frame 1A and returns to the initial position.

[0037] The sliding element 3D and the elastic element 3E cooperate to form a reset mechanism, used to push the pushing element Q to reverse and reset relative to the main frame 1. The elastic element 3E is a telescopic spring. Figure 11 and Figure 14 The sliding member 3D slides in conjunction with the pressure roller frame 3A, and has sliding grooves M1 and M2, a hook portion M3, and a force-bearing portion T12. The upper side of the elastic member 3E is engaged with the pressure roller frame 3A by a pin 3F, which passes through the sliding groove M1 of the sliding member 3D and limits the sliding range of the sliding member 3D relative to the pressure roller frame 3A. The lower side of the elastic member 3E is engaged with the hook portion M3. A shaft support N passes through the sliding groove M2 of the sliding member 3D and limits the sliding range of the sliding member 3D relative to the pressure roller frame 3A. In this manner, the elastic member 3E is engaged between the sliding member 3D and the pressure roller frame 3A. Figure 7 When the pusher Q rotates forward, the second pushing part Q3 of the pusher Q contacts the force-receiving part T12 of the sliding part 3D, thereby driving the pusher Q to slide relative to the pressure roller frame 3A in a set direction. When the pusher Q slides relative to the pressure roller frame 3A in a set direction, it will cause the elastic part 3E to elastically deform.

[0038] [Anti-movement component] The anti-movement component G is installed on the main frame 1, combined with...Figure 6 The anti-slip member G is configured to apply a radial clamping force to the shaft assembly 3C at least one end of the pressure roller 3B close to the thermal head assembly 2, so that the shaft assembly 3C is pressed against the groove wall of the bushing engagement groove K, thereby preventing the gap between the bushing engagement groove K and the shaft assembly 3C from affecting the printing effect.

[0039] Combination Figure 6 In this embodiment, the anti-slip member G has a pivot part G1, a pressure-applying part G2, a locking part G3, and a controlled part G4. The pivot part G1 is pivotally connected to the main frame 1. The pressure-applying part G2 is configured to pass through the slot K1 and contact the pressure-receiving surface 3C-1 to apply a radial clamping force to the shaft assembly 3C. The locking part G3 is configured to be fixed to the main frame 1 by a fastener H. The controlled part G4 is configured to controllably drive the pressure-applying part G2 to rotate around the pivot part G1 after the fastener H is removed. In this embodiment, the locking part G3 is a through hole, and the main frame 1 has a mating hole 1E that mates with the through hole. The size of the through hole is larger than the size of the mating hole 1E, and the fastener H is a fastening screw. The larger size of the through hole than the mating hole 1E facilitates adjustment of the clamping force of the pressure-applying part G2. This embodiment only provides one anti-slip member G to apply a radial clamping force to the shaft assembly 3C at one end. In another embodiment, two anti-slip members G may be provided to apply radial clamping force to the shaft assembly 3C at both ends.

[0040]

Paper Guide Component

[0041] [Drive Mechanism] The drive mechanism 5 is installed on the main frame 1A of the main frame 1. It includes a print drive motor 5A and a transmission gear assembly 5B. The print drive motor 5A drives the pressure roller 3B to rotate through the transmission gear assembly 5B.

[0042] The technical solution of this application, by installing an anti-movement component on the main frame, can apply a radial clamping force to the shaft assembly at least one end of the pressure roller close to the thermal head assembly, so that the shaft assembly is pressed against the groove wall of the shaft sleeve engagement groove, thereby eliminating the gap between the shaft assembly and the pressure roller frame, and avoiding the problem of horizontal stripe printing defects caused by the shaft assembly moving during printing in the prior art.

[0043] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A thermal printer comprising: a main frame (1) on which a thermal head assembly (2) is mounted; a platen roller frame (3A) on which a platen roller (3B) is mounted and which is capable of bringing the platen roller (3B) closer to or farther from the thermal head assembly (2); wherein the platen roller frame (3A) has a shaft sleeve engaging groove (K), both side end portions of the platen roller (3B) are supported in the shaft sleeve engaging groove (K) by means of a shaft sleeve member (3C), and the shaft sleeve member (3C) is limited by a notch (K1) of the shaft sleeve engaging groove (K) from being radially separated from the shaft sleeve engaging groove (K); characterized in that an anti-walk member (G) is mounted on the main frame (1) and is configured to apply a radially pressing force to the shaft sleeve member (3C) of at least one end of the platen roller (3B) closer to the thermal head assembly (2) so as to make the shaft sleeve member (3C) tightly contact with the groove wall of the shaft sleeve engaging groove (K).

2. The thermal printer according to claim 1, characterized by, the anti-walk member (G) has: a pivot portion (G1) pivoted to the main frame (1); a pressing portion (G2) configured to pass through the notch (K1) to apply a radially pressing force to the shaft sleeve member (3C); a locking portion (G3) configured to be fixed to the main frame (1) by means of a fastener (H); a controlled portion (G4) configured to be controlled to rotate the pressing portion (G2) around the pivot portion (G1) after the fastener (H) is detached.

3. The thermal printer according to claim 2, characterized by, the locking portion (G3) is a through hole, the main frame (1) has an engaging hole (1E) matched with the through hole, the size of the through hole is larger than the size of the engaging hole (1E), and the fastener (H) is a fastening screw.

4. The thermal printer according to any one of claims 1 to 3, characterized by the pressure surface (3C-1) of the shaft sleeve member (3C) matched with the anti-walk member (G) is a plane.

5. The thermal printer according to claim 1, characterized by, the platen roller frame (3A) is rotatably mounted on the main frame (1), a pushing member (Q) is rotatably mounted on the main frame (1), the pushing member (Q) drives the platen roller frame (3A) to rotate in a forward direction by rotating in a forward direction relative to the main frame (1), so that the platen roller (3B) is away from the thermal head assembly (2), and the rotation axis of the platen roller frame (3A) coincides with the rotation axis of the pushing member (Q).

6. The thermal printer according to claim 5, characterized by a reset mechanism is mounted between the pushing member (Q) and the platen roller frame (3A) to drive the pushing member (Q) to rotate in a reverse direction relative to the main frame (1).

7. The thermal printer according to claim 6, characterized by the reset mechanism comprises: a sliding member (3D) slidingly matched with the platen roller frame (3A) and driven to slide in a set direction relative to the platen roller frame (3A) when the pushing member (Q) rotates in the forward direction; a resilient member (3E) engaged between the sliding member (3D) and the platen roller frame (3A) and elastically deformed when the sliding member (3D) slides in the set direction relative to the platen roller frame (3A).

8. The thermal printer according to claim 7, characterized by the resilient member (3E) is engaged with the platen roller frame (3A) by means of a pin member (3F) passing through the sliding member (3D) and limiting the range of the sliding member (3D) relative to the platen roller frame (3A).

9. The thermal printer according to claim 7, characterized by Said pressing roller frame (3A) and said pusher (Q) are rotatably mounted on said main frame (1) by means of the same shaft support (N) which passes through said slide (3D) and defines the extent of the sliding of said slide (3D) with respect to said pressing roller frame (3A).

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