Printing device

Abstract

The present application provides a printing device capable of adjusting the position of a head unit relative to a platen roller. The head unit is obtained by adhering a head substrate having a print head formed thereon to a heat sink (53). The printing unit (5) fastens the head unit to a head holder (51) using fixing screws (73A, 73B). The head unit is movable in an adjustment direction relative to the head holder (51) by an adjustment mechanism (70). The adjustment mechanism (70) is an adjustment shaft (71A, 71B) fixed to the heat sink (53) and an eccentric cam (72A, 72B) having a circular cross-section and being eccentric and engaged with cam holes (51E, 51F) of the head holder (51). A spring (57) applies a force to a force application position (53C) of the head unit oscillatingly supported on a support shaft (5A), and presses the print head against the platen roller. The adjustment mechanism (70) is disposed between the force application position (53C) and the support shaft (5A) in the adjustment direction, and achieves miniaturization of the printing unit (5).

Description

Technical Field

[0001] This invention relates to a printing apparatus. Background Technology

[0002] Patent document 1 discloses a thermal line printer. The line printer has a position adjustment mechanism between the print head and the head holder on which the print head is mounted. The position adjustment mechanism uses an eccentric cam to move the print head relative to the head holder, adjusting the positional relationship between the print head and the paper clamp in the paper transport direction. After position adjustment, the print head is fixed to the head holder by fixing screws.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2001-88398 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In the line printer of Patent Document 1, the adjustment direction of the tool to the eccentric cam and the fixing direction of the fixing screw are opposite. In the case of a pressing load adjustment mechanism that presses the print head against the paper pressing element, in order to avoid interference with the position adjustment mechanism, it may lead to an increase in the size of the structure.

[0008] The object of the present invention is to provide a miniaturized printing apparatus that enables adjustment of the positional relationship between the head unit and the pressure roller.

[0009] Methods for solving problems

[0010] According to one aspect of the present invention, a printing apparatus is provided, characterized in that it comprises: a head unit, a print head having a plurality of heating elements arranged in a first direction and a heat sink for fixing the print head; a head holding member holding the head unit in a second direction intersecting the first direction; a pressure roller rotating about a rotation axis extending in the first direction; a support shaft extending in the first direction supporting the head holding member in a manner that allows the print head to swing between an approach position where the print head approaches the pressure roller and an isolation position where the print head is away from the pressure roller; and a force applying member applying force to the head unit, applying a pressing load to press the print head against the pressure roller. The adjustment mechanism includes: an adjustment shaft disposed on the heat sink at a position between the support shaft and the point where the force-applying member applies force to the head unit, i.e., the force-applying point, in a third direction intersecting the first and second directions, protruding toward the head holding member and extending in the second direction; and an eccentric cam rotatable about the adjustment shaft to contact the head holding member in an eccentric state relative to the adjustment shaft, and the head unit is moved relative to the head holding member by the rotation of the eccentric cam, thereby adjusting the position of the heating element relative to the pressure roller when the print head is in the approach position.

[0011] The printing apparatus of this solution has an adjustment mechanism between the force-applying part, which allows the force-applying component to apply a sufficient pressing load to the head unit held by the head-holding component, which is supported by the support shaft, and the support shaft. This allows for the miniaturization of the printing unit, and consequently, the miniaturization of the product.

[0012] Alternatively, the head retaining component of this solution may have two through holes at various positions separated along the first direction. These two through holes are for a fixing screw that secures the heat sink and the head retaining component together. The heat sink has two fastening portions corresponding to the two through holes and for tightening the fixing screw. One of the through holes has a larger gap in the first direction relative to the outer diameter of the fixing screw than the other through hole. The head unit is easily affected by the heat associated with the driving of the heating element due to miniaturization. If the heat sink expands due to heat, it tends to extend longer in the first direction of the heating element arrangement. Regarding the head unit, even if the heat sink expands, positional deviation relative to the head retaining component can be prevented by the gap in the first direction at one of the through holes.

[0013] Alternatively, this design may include a scale, located on one of the heat sink and the head holding component, arranged in an arc shape centered on the adjustment axis, indicating the rotational position of the eccentric cam. The printing device can easily adjust the position of the heating element relative to the pressure roller using the rotation of the eccentric cam based on the scale.

[0014] Alternatively, the force-applying portion of the heat sink in this solution may be positioned such that it corresponds to the configuration position of the heating element of the printhead in the second direction, but is offset upwards in the third direction. The force-applying portion of the heat sink is formed, for example, by stamping. Because the force-applying portion is offset upwards in the third direction relative to the configuration position of the heating element, the recess created by the stamping process is not located in the second direction of the heating element. Since there is no space between the printhead and the heat sink in the second direction of the heating element, the heat sink can achieve sufficient heat dissipation and prevent positional deviation of the printhead unit relative to the printhead holding member.

[0015] Alternatively, the force-applying component in this solution may be a compression coil spring, equipped with a spring-holding component. This spring-holding component is positioned opposite the head unit to the head-holding component and can swing together with the head-holding component around the support shaft. It has a first protrusion with a diameter larger than the inner diameter of the compression coil spring, which holds one end of the compression coil spring. The force-applying portion of the radiator is formed as a second protrusion with a diameter smaller than the inner diameter of the compression coil spring, which positions the other end of the compression coil spring. The other end of the compression coil spring has a gap between itself and the second protrusion in the radial direction. Therefore, the other end of the compression coil spring can accommodate changes in the position of the second protrusion during head unit position adjustments or positional deviations caused by thermal expansion of the radiator, maintaining the applied pressing load relative to the head unit.

[0016] Alternatively, the adjustment mechanisms in this solution can be positioned at separate locations along the first direction, with the force-applying part positioned between the two adjustment mechanisms along the first direction. The compression helical spring is located between the two adjustment mechanisms, thus not hindering the rotation of the eccentric cam. Therefore, the printing device can ensure ease of head unit position adjustment and achieve unit miniaturization. Attached Figure Description

[0017] Figure 1 This is a three-dimensional view of printing device 1.

[0018] Figure 2 This is a right view showing the positional relationship of the frame 7, the pressure roller 4, the printing unit 5, and the handle component 6.

[0019] Figure 3 This is a three-dimensional view of the pressure roller 4, printing unit 5, and handle component 6.

[0020] Figure 4 This is a top view of printing unit 5.

[0021] Figure 5 This is a perspective view of the printed unit 5 as seen from below.

[0022] Figure 6 It is along Figure 2 The bottom view of the printed unit 5 when the II line is cut off and viewed from the direction of the arrow.

[0023] Figure 7 It is along Figure 2 A cross-sectional view of printed unit 5 when the II-II line is cut off and viewed in the direction of the arrow.

[0024] Figure 8 It is along Figure 4 A cross-sectional view of printed unit 5 when cut along line III-III and viewed in the direction of the arrow.

[0025] Figure 9 It is along Figure 4 A cross-sectional view of printed unit 5 when the IV-IV line is cut off and viewed in the direction of the arrow.

[0026] Figure 10 It is along Figure 4 The cross-sectional view of printed unit 5 when the VV line is cut off and viewed from the direction of the arrow. Detailed Implementation

[0027] An embodiment of the printing apparatus 1 of the present invention will be described with reference to the accompanying drawings. The drawings are used to illustrate the technical features that can be employed in the present invention; the described apparatus structure, etc., are not intended to be limited thereto, but are merely illustrative examples. Figure 1 The top, bottom, upper left, lower right, lower left, and upper right are respectively designated as the top, bottom, left, right, front, and rear of the printing device 1.

[0028] <Overview of Printing Device 1>

[0029] Reference Figures 1-3 The following describes the general outline of the printing device 1. Printing device 1 is a thermal transfer type printing device. Printing device 1 performs printing using printhead 50 (see reference). Figure 3 The action of heating the ink ribbon and transferring the ink from the ink ribbon to the printing medium 90 (hereinafter referred to as "printing action").

[0030] like Figure 1 As shown, the printing device 1 includes a housing 2. The housing 2 holds the frame 7 of the printing device 1 (see reference). Figure 2The printing unit 1 is housed internally. The frame 7 supports the pressure roller 4, printing unit 5, handle assembly 6, control unit (not shown), drive unit 20, etc. The control unit has a CPU that controls the entire printing device 1. The drive unit 20 is an electric motor for transporting the printing media 90 and ink ribbon. Details of the pressure roller 4, printing unit 5, and handle assembly 6 will be described later. The housing 2 is box-shaped and has an upper wall 2U, a lower wall 2S, a left wall 2L, a right wall 2R, a front wall 2F, a rear wall 2B, and a cover 2C.

[0031] A plurality of switches 21 are provided at the front end of the upper surface of the upper wall 2U. Further rearward from the switches 21, a discharge section 22 is provided on the upper surface. The discharge section 22 is a through hole formed in the upper wall 2U. The shape of the discharge section 22 is a rectangle that extends in the left-right direction. The printing medium 90, after being printed inside the housing 2, is discharged outside the housing 2 via the discharge section 22. A cutting section 23 provided at the front end of the discharge section 22 is a blade capable of cutting off the printed portion of the printing medium 90.

[0032] An opening 26 is provided on the right surface of the right wall 2R. The opening 26 communicates with a belt assembly part 27 located within the housing 2. The belt cassette 3 is assembled into the belt assembly part 27 in a detachable manner. It should be noted that... Figure 1 This shows the tape box 3 detached from the tape assembly 27.

[0033] The tape cassette 3 houses a tape roll (not shown) wound around a cylindrical core and a take-up roll for winding up used tape. The tape released from the tape roll is transported forward within the housing 2. During transport, the tape is heated by the printhead 50 (described later). The heated tape is then wound up by the take-up roll.

[0034] An opening 28 is formed at the rear end of the housing 2 near the rear end of the upper wall 2U, the upper end of the rear wall 2B, and the upper ends of the left wall 2L and the right wall 2R, respectively. The cover 2C is rotatably supported on the upper end of the rear wall 2B and can open and close the opening 28. Figure 1 This shows the state where opening 28 is open through the cover 2C. It should be noted that... Figure 1 The dashed line indicates that the opening 28 is closed by the cover 2C. The opening 28 communicates with the media assembly section 29 located inside the housing 2. The media assembly section 29 assembles the printing media 90 wound around a cylindrical core in a removable manner. The user can replace the media roll 9 by opening the opening 28.

[0035] The printing medium 90 is released from the media roll 9 assembled in the media assembly section 29 and transported forward toward the discharge section 22 within the housing 2. During part of the transport process, the printing medium 90 runs parallel to the ink ribbon released from the tape roll in the tape cassette 3. At the parallel portions of the printing medium 90 and the ink ribbon (hereinafter referred to as the "parallel portions"), the print head 50 heats the ink ribbon, transferring the ink from the ink ribbon to the printing medium 90. The ink-transferred printing medium 90 is discharged out of the housing 2 via the discharge section 22.

[0036] <Paper Press Roller 4>

[0037] The pressure roller 4 clamps the parallel portions of the printing medium 90 and the ink ribbon between the pressure roller 4 and the print head 50. For example... Figure 2 , Figure 3 As shown, the pressure roller 4 is cylindrical. The pressure roller 4 is positioned on the upper side parallel to the printing medium 90. A through hole 40 extending in the left-right direction is provided in the pressure roller 4. A rotating shaft 4A is inserted through the through hole 40. The rotating shaft 4A extends in the left-right direction. Both ends of the rotating shaft 4A are fixed to the frame 7. It should be noted that... Figure 2 The diagram shows the left and top frames 7. The pressure roller 4 is supported rotatably by a rotating shaft 4A. The center of rotation of the pressure roller 4 coincides with the center 4C of the rotating shaft 4A. The drive unit 20 is fixed to the front of the left frame 7. The left frame 7 has multiple gears (not shown) on its left surface. The multiple gears transmit the driving force generated by the drive unit 20 to the pressure roller 4.

[0038] <Printing Unit 5>

[0039] The printing unit 5 uses the print head 50 to heat the parallel portion of the ink ribbon, transferring the ink to the printing medium 90. The printing unit 5 is positioned below the parallel portion of the ink ribbon. The printing unit 5 includes a head holder 51, a moving part 56, and a pair of springs 57.

[0040] The head holder 51 has a base 51A and a pair of protrusions 51B. The base 51A is plate-shaped, extending in the left-right direction and intersecting the up-down direction. The pair of protrusions 51B protrude rearward from the rear end of the base 51A and from both the left and right ends. Each of the pair of protrusions 51B has a through hole extending in the left-right direction. A support shaft 5A is inserted through the through hole of each of the pair of protrusions 51B. The support shaft 5A extends in the left-right direction. The left and right ends of the support shaft 5A are respectively fixed to the left and right frames 7. The head holder 51 is rotatably supported by the support shaft 5A. The rotation center of the head holder 51 coincides with the center 5C of the support shaft 5A. The center 5C is located below and behind the center 4C of the rotation shaft 4A supporting the pressure roller 4.

[0041] Figure 3The image shows the head holder 51 rotated to its maximum counterclockwise position about the support shaft 5A, viewed from the right. In this position, the base 51A moves downward away from the pressure roller 4. Hereinafter, [the following section will describe the configuration of...] Figure 3 The position of the head retainer 51 in the rotational position shown is called the "isolation position". On the other hand, Figure 2 The image shows the head retainer 51 rotated to its maximum clockwise position about the support shaft 5A, viewed from the right. In this position, the base 51A approaches the pressure roller 4 from below. Hereinafter, [the following will describe the configuration of...] Figure 2 The position of the head retainer 51 in the rotational position shown is called the "approach position".

[0042] like Figure 2 , Figure 3 As shown, the printhead 50 is disposed on the upper surface of the printhead substrate 54. The printhead 50 is a row-type thermal printhead composed of multiple heating elements, extending in the left-right direction. The printhead substrate 54 is glued and fixed to the upper surface of the heat sink 53 by adhesive. The printhead substrate 54 and the heat sink 53 are fixed as a single unit 52. The printhead unit 52 has the heat sink 53 positioned below it, and the printhead unit 52 is mounted on the upper surface of the base 51A of the printhead holder 51.

[0043] The movable part 56 includes a bearing part 56A, an extension part 56B, and a spring receiving part 56C. The bearing part 56A is disposed between a pair of protrusions 51B of the head holder 51. The bearing part 56A has a through hole extending in the left-right direction. A support shaft 5A is inserted through the through hole of the bearing part 56A. The movable part 56 is supported by the support shaft 5A in a manner that allows it to swing with its front end as the free end. The rotation center of the movable part 56 coincides with the center 5C of the support shaft 5A. That is, both the head holder 51 and the movable part 56 can rotate around the support shaft 5A. The extension part 56B extends forward and downward from the bearing part 56A. The spring receiving part 56C is disposed at the front end of the extension part 56B. The spring receiving part 56C is disposed below the base 51A of the head holder 51. The spring receiving part 56C receives a pair of springs 57 on its upper surface.

[0044] A pair of springs 57 are positioned above the spring receiving portion 56C and near its left and right ends. A pair of protrusions 56D and 56E are formed in the spring receiving portion 56C. The pair of springs 57 are compression coil springs. The lower ends of the pair of springs 57 respectively engage with the protrusions 56D and 56E. The pair of springs 57 are located between the force-applying portion 53C of the head unit 52, which is fixed to the base 51A of the head holder 51, and the spring receiving portion 56C of the moving portion 56 (see reference). Figure 10 ).

[0045] <Handle Component 6>

[0046] The handle component 6 accepts user operation and presses the print head 50 of the printing unit 5 toward the pressure roller 4. The handle component 6 has a pressing part 65 and an operating part 66.

[0047] The pressing part 65 has a bearing part 61 and a pair of abutting parts 62. The bearing part 61 is cylindrical and extends in the left-right direction. The bearing part 61 has a through hole extending in the left-right direction. A rotating shaft (not shown) fixed in the housing 2 (hereinafter referred to as the "handle rotating shaft") enters the through hole from the left end of the bearing part 61 and extends to the right end. At the right end of the handle rotating shaft, the bearing part 61 is threadedly fastened by a screw 60 in a manner that prevents it from falling off the handle rotating shaft. The center of the handle rotating shaft is referred to as the "center 6C". The center 6C is located below the center 5C of the support shaft 5A supporting the printing unit 5 and in front of the center 4C of the rotating shaft 4A supporting the pressure roller 4. The pair of abutting parts 62 protrude from the bearing part 61 in a radial direction centered on the center 6C of the handle rotating shaft. The pair of abutting parts 62 are separated in the left-right direction, which is parallel to the handle rotating shaft. The left-right spacing of each pair of abutting parts 62 is approximately the same as the left-right spacing of the pair of springs 57. A pair of abutment portions 62 can contact the spring receiving portion 56C of the moving portion 56 from below. The operating portion 66 has a rod-shaped extension that bends from one end 66A to the other end 66B. One end 66A is connected to the left end of the bearing portion 61.

[0048] The handle component 6 is supported by a handle rotation axis in a rotatable manner. The rotation center of the handle component 6 coincides with the center 6C of the handle rotation axis. Figure 3 The diagram shows the handle assembly 6 rotated to its maximum clockwise position about the handle rotation axis when viewed from the right. In this state, the pair of abutment portions 62 of the pressing portion 65 are slightly isolated downwards relative to the spring receiving portion 56C of the moving portion 56. In this case, the pair of springs 57 located between the spring receiving portion 56C and the head holder 51 are not compressed and do not press the head holder 51. Therefore, the head holder 51 is positioned in the isolated position.

[0049] As the handle component 6 rotates counterclockwise when viewed from the right, a pair of abutment portions 62 of the pressing portion 65 contact the spring receiving portion 56C of the head holder 51 from below, applying an upward force to the spring receiving portion 56C. The moving portion 56 rotates clockwise when viewed from the right, based on the force received by the spring receiving portion 56C from the pair of abutment portions 62. Additionally, the head holder 51 rotates clockwise when viewed from the right, based on the upward force received from the moving portion 56 via a pair of springs 57. As a result, the head holder 51 rotates from the isolated position to the approach position.

[0050] Figure 2The diagram shows the handle assembly 6 rotated to its maximum counterclockwise position about the handle rotation axis when viewed from the right. In this state, a pair of springs 57 are compressed. The pair of springs 57 press the head holder 51 with the elastic force generated by the compression. In this case, the print head 50 of the head holder 51 is pressed towards the pressure roller 4.

[0051] <Position adjustment function of printing unit 5>

[0052] The printing unit 5 of the printing apparatus 1 in this embodiment includes an adjustment mechanism 70 capable of adjusting the positional relationship between the print head 50 and the pressure roller 4. (Refer to...) Figures 4 to 10 The adjustment mechanism 70 will now be explained. It should be noted that, in the following explanation, the direction in which the head holder 51 holds the head unit 52, i.e., the thickness direction of the heat sink 53 and the head substrate 54, is defined as the "holding direction" in the printing unit 5. Furthermore, in the printing unit 5, with the print head 50 in the approach position as a reference, the side of the heat sink 53 is referred to as the "upper side" of the holding direction, and the side of the head holder 51 is referred to as the "lower side" of the holding direction. Additionally, the transport direction of the printing medium 90 relative to the printing unit 5, with the print head 50 in the approach position as a reference, is a direction orthogonal to the left-right direction of the print head 50 and the thickness direction of the head substrate 54. In the following explanation, the direction that is approximately consistent with the transport direction during printing is defined as the "adjustment direction" in the printing unit 5. That is, the adjustment direction is the direction in which the position of the heat sink 53 relative to the head holder 51 is adjusted in the printing unit 5. In addition, regarding the adjustment direction, the direction in which the print head 50 is moved upstream of the paper pressure roller 4 in the direction of transporting the printing medium 90 is called the "positive side", and the direction in which the print head 50 is moved downstream of the paper pressure roller 4 in the direction of transporting the printing medium 90 is called the "negative side".

[0053] The adjustment mechanism 70 is a mechanism that moves the position of the head unit 52 relative to the head holder 51 in the adjustment direction to adjust the positional relationship between the print head 50 and the pressure roller 4. For example... Figure 4 As shown, the printhead 50 extends in the left-right direction on the upper surface of the printhead base plate 54, near the edge of the adjustment direction. The printhead base plate 54 extends relatively long in the left-right direction, and its length in the adjustment direction is approximately half the size of the heat sink 53. The printhead base plate 54 is fixed to the upper surface of the heat sink 53 near the negative side of the adjustment direction. The heat sink 53 is disposed on the upper surface of the base 51A of the printhead holder 51 and is secured by two fixing screws 73A and 73B (see reference). Figure 5 Securely fastened. That is, the head base plate 54 with the print head 50 and the heat sink 53 are held as an integral head unit 52 in the holding direction of the head holder 51.

[0054] like Figures 5-10 As shown, fixing screw 73A is a bolt with a cross-shaped hole. Fixing screw 73B is a bolt with a hexagonal hole. The outer diameter of the shaft of fixing screw 73B is larger than that of fixing screw 73A. The radiator 53 has threaded holes 53A and 53B at its corners on both sides of the negative adjustment direction for tightening the fixing screws 73A and 73B. The threaded holes 53A and 53B are formed in portions that are extruded downwards from the upper surface of the radiator 53 by stamping and protrude at the lower surface. On the upper surface of the radiator 53, a recess 53F is formed at a position corresponding to the threaded holes 53A and 53B (see reference). Figure 9 ).

[0055] On the lower surface of the radiator 53, the area between the threaded holes 53A and 53B is the force-applying portion 53C where the upper end of the spring 57 presses the head unit 52 upward. A pair of protrusions 53D and 53E protruding downward from the radiator 53 are provided on the force-applying portion 53C. The protrusions 53D and 53E are formed at positions separated from each other in the left-right direction. The protrusions 53D and 53E are extruded downward from the upper surface of the radiator 53 by stamping, protruding in a cylindrical shape. On the upper surface of the radiator 53, a recess 53G is formed at a position corresponding to the protrusions 53D and 53E (see reference). Figure 10 ).

[0056] Thus, the recesses 53F and 53G in the adjustment direction are each formed at a position that does not overlap with the formation position of the printhead 50 on the head substrate 54 attached to the heat sink 53 in the holding direction. Therefore, in the holding direction of the printhead 50, no space formed by the recesses 53F and 53G is provided between the head substrate 54 and the heat sink 53. Therefore, the heat sink 53 can effectively dissipate heat conducted from the head substrate 54 accompanying the driving of the printhead 50.

[0057] like Figure 7 As shown, the radiator 53 has a pair of adjustment shafts 71A and 71B on the positive side of the adjustment direction of the threaded holes 53A and 53B, respectively. The adjustment shafts 71A and 71B are in the shape of round bars and are fixed to the lower surface of the radiator 53 by riveting, extending downward in the holding direction.

[0058] The base 51A of the head retainer 51 has through holes 51C and 51D at its left and right corners on the negative side of the adjustment direction. These holes are through in the retaining direction and allow the shafts of the fixing screws 73A and 73B to be inserted. The through holes 51C and 51D are elongated ovals, longer in the adjustment direction. The through holes 51C and 51D are located where the threaded holes 53A and 53B of the heat sink 53 are positioned within the through holes 51C and 51D in the retaining direction (see reference). Figure 8The length of the through hole 51C in the left-right direction is approximately the same as the outer diameter of the shaft of the fixing screw 73A, while the length in the adjustment direction is larger than the outer diameter of the shaft of the fixing screw 73A. The gap G1 formed in the left-right direction between the through hole 51C and the shaft of the fixing screw 73A is such that it does not impede smooth movement in the axial adjustment direction. By guiding the shaft of the fixing screw 73A through the through hole 51C, the adjustment mechanism 70 can restrict the position adjustment of the print head 50 in the left-right direction, while limiting the position adjustment of the print head 50 in the adjustment direction.

[0059] In the left-right direction, the gap G2 formed between the through hole 51D and the shaft of the fixing screw 73B is larger than the gap G1. When subjected to the heat associated with the drive of the print head 50, the length of the heat sink 53 extending in the left-right direction due to thermal expansion is greater than that in the adjustment direction. The printing unit 5 can absorb the left-right extension of the heat sink 53 relative to the head holder 51 that may occur due to thermal expansion using the gap G2, preventing positional deviation of the print head 50. Furthermore, by guiding the shaft of the fixing screw 73B through the through hole 51D, the adjustment mechanism 70 can adjust the position of the print head 50 in the adjustment direction.

[0060] The base 51A of the head retainer 51 has cam holes 51E and 51F on the positive side of the insertion holes 51C and 51D in the adjustment direction, which are through in the holding direction and are respectively configured for the two adjustment mechanisms 70. The two adjustment mechanisms 70 are adjustment shaft 71A and eccentric cam 72A and adjustment shaft 71B and eccentric cam 72B. Cam holes 51E and 51F are approximately rectangular in shape, with the longer portion in the left-right direction. Adjustment shafts 71A and 71B support eccentric cams 72A and 72B in a rotatable manner. Adjustment shafts 71A and 71B are respectively positioned approximately at the center of cam holes 51E and 51F. The cross-section of the eccentric cams 72A and 72B in the holding direction is circular, and the eccentric cams 72A and 72B have insertion holes for adjustment shafts 71A and 71B at positions off-center from the center of the cross-section. The lengths of the cam holes 51E and 51F in the adjustment direction are approximately the same as the diameters of the cross-sections of the eccentric cams 72A and 72B. The eccentric cams 72A and 72B can rotate around the adjustment shafts 71A and 71B respectively, and contact the cam holes 51E and 51F in the adjustment direction in an eccentric state relative to the adjustment shafts 71A and 71B. Handles 74A and 74B are fixed to the lower ends of the eccentric cams 72A and 72B respectively (see reference). Figure 5 The operator can operate handles 74A and 74B to rotate eccentric cams 72A and 72B respectively.

[0061] Furthermore, the base 51A of the head retainer 51 has an opening 51G in the left-right direction between the insertion hole 51C, the cam hole 51E and the insertion hole 51D, the cam hole 51F, for inserting the spring 57 in the holding direction. The force-applying part 53C of the head unit 52 is exposed downward in the holding direction through the opening 51G.

[0062] like Figure 10 As shown, the printing unit 5 arranges a pair of springs 57 between the protrusions 53D and 53E formed in the force-applying portion 53C of the head unit 52 and the protrusions 56D and 56E formed in the spring-receiving portion 56C of the moving portion 56. The outer diameter D2 of the protrusions 56D and 56E of the spring-receiving portion 56C is larger than the inner diameter D0 of the spring 57. The lower end of the spring 57 is embedded in the protrusions 56D and 56E to prevent it from falling out. The outer diameter D1 of the protrusions 53D and 53E of the force-applying portion 53C is smaller than the inner diameter D0 of the spring 57. The protrusions 53D and 53E are arranged inside the upper end of the spring 57 to suppress the positional deviation of the upper end of the spring 57 in the force-applying portion 53C. Furthermore, even if the position of the head unit 52 is changed by the adjustment mechanism 70 or the heat sink 53 expands thermally, the relative position between the protrusions 53D and 53E and the upper end of the spring 57 can be deviated from the original position due to the radial difference.

[0063] like Figure 7 As shown, the adjustment mechanism 70 positions the pair of springs 57 separately in the left-right direction. This allows the pair of springs 57 to apply the pressing load to the print head 50 more evenly in the left-right direction. Furthermore, the printing unit 5 has a structure in which two adjustment mechanisms 70 are positioned separately in the left-right direction, and a pair of springs 57 are arranged between the adjustment mechanisms 70. That is, the handles 74A and 74B and the fixing screws 73A and 73B are positioned outside the spring receiving portion 56C and the force applying portion 53C in the left-right direction. Therefore, in the printing unit 5, the operation of the handles 74A and 74B and the tightening of the fixing screws 73A and 73B are less likely to be obstructed by the spring receiving portion 56C and the force applying portion 53C.

[0064] Furthermore, two adjustment mechanisms 70 are arranged in the adjustment direction between the force-applying portion 53C of the head unit 52 and the support shaft 5A of the head support holder 51. The printing unit 5 is configured to ensure the distance between the force-applying portion 53C and the support shaft 5A, thereby enabling the application of sufficient pressing load from the spring 57 to the head unit 52. Based on this, by arranging the adjustment mechanisms 70 for adjusting the position of the head unit 52 between the force-applying portion 53C and the support shaft 5A, the printing unit 5 optimizes the layout of each component and prevents the printing unit 5 from becoming too large.

[0065] like Figure 6As shown, the head retainer 51 has scales 75A and 75B on its lower surface. Scale 75A is formed around the cam hole 51E for which the eccentric cam 72A is disposed on the right side of the adjusting shaft 71A, arranged in an arc shape centered on the adjusting shaft 71A. Scale 75B is formed around the cam hole 51F for which the eccentric cam 72B is disposed on the left side of the adjusting shaft 71B, arranged in an arc shape centered on the adjusting shaft 71B. The handle portions 74A and 74B of the eccentric cams 72A and 72B respectively have indicator plates 74C and 74D. Indicator plates 74C and 74D are protrusions that project radially from the outer periphery of the handle portions 74A and 74B toward the adjusting shafts 71A and 71B. The indicator plate 74C of the handle portion 74A protrudes to the right and indicates scale 75A when viewed from below in the holding direction. The indicator 74D of the handle 74B protrudes to the left, indicating the scale 75B when viewed from below in the holding direction. That is, the adjustment mechanism 70 can indicate the position of the head unit 52 relative to the head holder 51 by the position of the scales 75A and 75B indicated by the indicators 74C and 74D.

[0066] <Print head 50 position adjustment action>

[0067] The operation of adjusting the position of the print head 50 relative to the pressure roller 4 using such an adjustment mechanism 70 is performed, for example, during the manufacturing process of the printing device 1. The operator loosens the fixing screws 73A and 73B of the print unit 5, allowing the head unit 52 to move relative to the head holder 51. Next, the operator rotates the handles 74A and 74B while checking the positions of the indicator scales 75A and 75B on the indicator plates 74C and 74D. The eccentric cams 72A and 72B press against the cam holes 51E and 51F respectively, and the through holes 51C and 51D guide the shafts of the fixing screws 73A and 73B in the adjustment direction. The head unit 52 moves relative to the head holder 51 to the positive or negative side of the adjustment direction. Thus, the position adjustment of the print head 50 relative to the pressure roller 4 is performed in the adjustment direction. After the position adjustment, the operator tightens the fixing screws 73A and 73B to fix the head unit 52 to the head holder 51, completing the operation.

[0068] <Printing Action>

[0069] The user operates the operating unit 66 of the printing device 1, rotating the handle component 6 clockwise when viewed from the right. This isolates the pressure roller 4 and the base 51A of the head holder 51 in the printing unit 5 vertically. Next, the user assembles the tape cassette 3 into the printing device 1. Then, the user assembles the media roll 9 into the printing device 1, releasing the printing media 90 forward and guiding it to the ejection unit 22. At this time, the parallel portions of the ink ribbon in the tape cassette 3 and the printing media 90 pass between the pressure roller 4 and the head holder 51. It should be noted that since the print head 50 supported by the head holder 51 and the ink ribbon are isolated, printing cannot be performed in this state.

[0070] Next, the user operates the operating unit 66, rotating the handle component 6 counterclockwise when viewed from the right. This causes the parallel portions of the ink ribbon and the printing medium 90 to be clamped by the pressure roller 4 and the head holder 51. At this time, the pressure roller 4 contacts the printing medium 90 from above, and the print head 50 contacts the ink ribbon from below. Furthermore, the print head 50, supported by a pair of springs 57, is pressed towards the pressure roller 4 by the elastic force of these springs.

[0071] Next, the user inputs an operation to switch 21 to start the printing operation. The printing device 1 begins printing. The control unit controls the drive unit 20 to transport the printing medium 90 and the ink ribbon. At the same time, the control unit starts heating the print head 50. As a result, the ink ribbon is heated and ink is transferred to the printing medium 90. The ink-coated printing medium 90 is discharged from the discharge unit 22.

[0072] <Function and Effects of This Implementation Method>

[0073] As explained above, the printing unit 5 has an adjustment mechanism 70 positioned between the force-applying part 53C, where the spring 57 can apply a sufficient pressing load to the head unit 52 held by the head holder 51, which is supported by the support shaft 5A, and the support shaft 5A. This allows the printing apparatus 1 to miniaturize the head unit 52, and consequently, to miniaturize the product.

[0074] The head unit 52 is susceptible to heat associated with the drive of the print head 50 due to its miniaturization. If the heat sink 53 expands due to heat, it tends to extend excessively in the lateral direction of the heat-generating element arrangement. Regarding the head unit 52, even if the heat sink 53 expands, the lateral clearance G2 between the through hole 51D and the axis of the fixing screw 73B prevents positional deviation relative to the head holder 51.

[0075] The printing unit 5 can easily adjust the position of the print head 50 relative to the pressure roller 4 by rotating the eccentric cams 72A and 72B with the scales 75A and 75B as a reference.

[0076] The force-applying portion 53C of the head unit 52 is formed, for example, by stamping the heat sink 53. Because the force-applying portion 53C is formed offset in the adjustment direction relative to the position corresponding to the print head 50's configuration position, the recesses 53F and 53G created by the stamping process are not located in the holding direction of the print head 50. Since there is no space between the print head 50 and the heat sink 53 in the holding direction of the print head 50, the heat sink 53 can achieve sufficient heat dissipation. Therefore, the printing unit 5 can prevent positional deviation of the head unit 52 relative to the head holder 51.

[0077] The upper end of the spring 57 has a gap between itself and the protrusions 53D and 53E in the radial direction. Therefore, the upper end of the spring 57 can accommodate changes in the position of the protrusions 53D and 53E caused by the position adjustment of the head unit 52 or positional deviations caused by the thermal expansion of the heat sink 53, and can maintain the applied pressing load relative to the head unit 52.

[0078] Spring 57 is positioned between the two adjustment mechanisms 70 in the left-right direction, thus not obstructing the operation of the handles 74A and 74B relative to the eccentric cams 72A and 72B. Therefore, the printing device 1 can ensure the ease of position adjustment of the head unit 52 and achieve miniaturization of the printing unit 5.

[0079] In the above embodiments, the left-right direction is an example of the "first direction" of the present invention. The holding direction is an example of the "second direction" of the present invention. The head holder 51 is an example of the "head holding member" of the present invention. The spring 57 is an example of the "force-applying member" of the present invention. The adjustment direction is an example of the "third direction" of the present invention. The threaded holes 53A and 53B are examples of the "fastening part" of the present invention. The protrusions 56D and 56E are examples of the "first protrusion" of the present invention. The protrusions 53D and 53E are examples of the "second protrusion" of the present invention.

[0080] <Variation Example>

[0081] This invention is not limited to the above-described embodiments and various modifications are possible. The printing method of the printing device 1 is not limited to a thermal transfer method in which ink from an ink ribbon is heated and transferred using the print head 50. For example, the printing method of the printing device 1 could also be a thermal method in which thermal paper is heated using the print head 50 to produce color. A single spring located only in the center in the left-right direction could be used instead of a pair of springs 57. An elastomer that generates elastic force through compression could also be used instead of a spring.

[0082] Alternatively, a single eccentric cam, located on one side or in the center, can be used instead of a pair of eccentric cams 72A and 72B. The cross-section of the eccentric cams 72A and 72B is not limited to a circular shape; it can also be elliptical. Adjustment shafts 71A and 71B can also be provided on the eccentric cams 72A and 72B and inserted into the insertion holes formed in the radiator 53 to rotate the eccentric cams 72A and 72B.

[0083] Alternatively, a single fixing screw located on one side or in the center in the left-right direction can be used instead of a pair of fixing screws 73A and 73B. Alternatively, a pin guided by the through hole 51C can be used instead of fixing screw 73A and fixed to the heat sink 53. The scales 75A and 75B can be formed by printing onto the head holder 51 or can be set by machining the lower surface of the head holder 51.

[0084] Explanation of reference numerals in the attached figures

[0085] 1. Printing device

[0086] 4. Paper pressure rollers

[0087] 4A Rotary Shaft

[0088] 5A Support Shaft

[0089] 50 printheads

[0090] 51-head retainer

[0091] 51C and 51D through holes

[0092] 52-head unit

[0093] 53 Radiator

[0094] 53A and 53B threaded holes

[0095] 53C Force application point

[0096] 53D and 53E protrusions

[0097] 53F, 53G concave part

[0098] 56. Mobile Department

[0099] 56D and 56E protrusions

[0100] 57 Springs

[0101] 70 Adjustment mechanism

[0102] 71A, 71B Adjustment Shaft

[0103] 72A and 72B eccentric cams

[0104] 73A and 73B fixing screws

[0105] 75A and 75B scales

[0106] G1 and G2 gaps

Claims

1. A printing device, characterized by, have: The print head unit includes a print head with multiple heating elements arranged in a first direction and a heat sink for fixing the print head. A head holding component holds the head unit in a second direction intersecting the first direction; The pressure roller rotates about a rotation axis extending in the first direction; A support shaft extends in the first direction and supports the head holding member in a manner that allows the print head to swing between a position close to the pressure roller and a position away from the pressure roller. The force-applying component applies force to the head unit, applying a pressing load that presses the print head against the pressure roller; and The adjustment mechanism includes: an adjustment shaft disposed on the heat sink in a third direction intersecting the first and second directions, between the support shaft and the point where the force-applying member applies force to the head unit (i.e., the force-applying point), protruding toward the head holding member and extending in the second direction; and an eccentric cam rotatable about the adjustment shaft, contacting the head holding member in an eccentric state relative to the adjustment shaft, and, by rotating the eccentric cam, moving the head unit relative to the head holding member, thereby adjusting the position of the heating element relative to the pressure roller when the print head is in the approach position. The head retaining component has a through hole at a position separated from the adjustment mechanism, through which a fixing screw for securing the heat sink and the head retaining component together is inserted. The radiator has a fastening part corresponding to the through hole and for fastening the fixing screw.

2. The printing apparatus according to claim 1, characterized in that, The head retaining component has two through holes at each of the separation positions along the first direction, and the two through holes are for the insertion of fixing screws that secure the heat sink and the head retaining component together. The radiator has two fastening parts that correspond to the two through holes and are used for fastening the fixing screws. One of the two through holes has a larger gap in the first direction relative to the outer diameter of the fixing screw than the other through hole.

3. The printing apparatus according to claim 1 or 2, characterized in that, The printing device has a scale, which is located on one of the heat sink and the head holding component and arranged in an arc shape centered on the adjustment axis, indicating the rotational position of the eccentric cam.

4. The printing apparatus according to claim 1 or 2, characterized in that, The force-applying part of the heat sink is located at the position corresponding to the configuration position of the heating element of the print head in the second direction, and at the position offset upward in the third direction.

5. The printing apparatus according to claim 4, characterized in that, The force-applying component is a compression coil spring. The printing device includes a spring-holding member disposed on the side opposite to the head unit relative to the head-holding member. This spring-holding member is capable of pivoting with the head-holding member about the support shaft and has a first protrusion with a diameter larger than the inner diameter of the compression coil spring. This first protrusion is used to hold one end of the compression coil spring. The force-applying portion of the radiator is formed as a second protrusion with a diameter smaller than the inner diameter of the compression coil spring, which positions the other end of the compression coil spring.

6. The printing apparatus according to claim 5, characterized in that, The adjustment mechanism is located at various positions separated along the first direction. The force-applying part is positioned between the two adjustment mechanisms in the first direction.

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