Character printing unit and thermal printer

Abstract

A printing unit includes: a head unit having a thermal head that performs printing on a recording paper; a platen unit that is combined with the head unit so as to be separable, has a platen roller that feeds the recording paper and a pair of platen bearings that rotatably support both end portions of the platen roller, respectively; an operation lever that is movable around a rotation axis between a locked position that locks the platen unit to the head unit and an unlocked position that releases the locking of the platen unit to the head unit; a platen locking mechanism that has a locking arm that oscillates around an oscillation axis parallel to the platen roller, and switches between a locked state that locks the platen roller and an unlocked state that releases the locking; and a force applying member that applies force to the locking arm around the oscillation axis in order to maintain the locked state. The head unit is formed with a pair of housing grooves that allow the pair of platen bearings to be inserted into the interior through an opening, and when the operation lever is in the locked position, the housing grooves house the platen bearings in a state in which the platen bearings are in contact with the bottom of the grooves.

Description

Technical Field

[0001] This invention relates to printing units and thermal printers. Background Technology

[0002] As a thermal printer, it is known that the thermal head and pressure roller can be detachably combined together.

[0003] For example, a thermal printer is known in which a head unit having a thermal head is disposed on the housing side that receives a roll of paper, and a pressure unit having a pressure roller is disposed on the printer cover side, the printer cover being connected to the housing in an open / closeable manner. According to this thermal printer, the thermal head and the pressure roller can be detachably combined with the opening / closing operation of the printer cover.

[0004] Typically, thermal printers, when assembling the thermal head and pressure roller, often have a locking mechanism to hold the pressure roller in place, preventing them from separating when not needed. One known locking mechanism is a spring member pressing against bearings located at both ends of the pressure roller shaft. The spring member is located on the head unit on the housing side, and when the bearing is inserted into the bearing groove, the spring member uses its own elastic restoring force (spring force) to press the bearing. This allows the bearing to be pressed against the bearing groove with a constant pressing force, and the pressure roller to be locked (held).

[0005] However, when the pressure roller is locked using a spring member, the bearing is only pressed by the spring member, making the locking of the pressure roller prone to inadequacy. Therefore, for example, when an external force is applied to the pressure roller, the bearing may move in a direction that pulls it out of its bearing slot. Consequently, the meshing between the driven gear integrally mounted on the bearing and the gear train used to drive the pressure roller becomes insufficient, potentially resulting in a defect known as "tooth skipping" or the meshing itself being disengaged. Furthermore, the bearing may slip out of its bearing slot, causing the head unit and the pressure plate unit to separate. This is particularly problematic when the pressure plate unit is mounted on the printer cover, as external forces can easily act on the pressure roller through the cover, thus easily causing the aforementioned defects.

[0006] For example, increasing the spring force of the spring component could be considered as a countermeasure to the aforementioned problems. However, in this case, when separating the head unit from the pressure plate unit, the bearing has difficulty sliding out of the bearing groove, thus requiring a larger force to release the pressure plate roller. This leads to reduced operability.

[0007] Therefore, known thermal printers employ a locking arm instead of a spring component, where the locking arm is used to lock the pressure roller. For example, in known thermal printers, the pressure roller is locked by using the spring force of the head pressure spring used to press the thermal head against the pressure roller via the locking arm to press the bearing against the bearing groove. According to this thermal printer, unlike a spring component, a locking arm is used, thus preventing the bearing from sliding out of the bearing groove.

[0008] However, even in the locking arm configuration, the locking arm is pressed against the bearing by the spring force of the head pressure spring. Therefore, the force required to release the pressure roller depends on the spring force of the head pressure spring, which can easily result in a larger force than required. Consequently, this can also easily lead to reduced operability, leaving room for improvement.

[0009] Furthermore, this locking arm is typically configured to lock the bearing from the pressure plate unit side. Therefore, when the locking arm is released, it moves towards the pressure plate unit side, separating from the thermal head side. Consequently, considering the movable stroke of the locking arm, it is necessary to ensure sufficient space, thus requiring a larger pressure plate unit design. The pressure plate unit typically has fewer components than the head unit, so miniaturization and thinning are desirable for a compact design. However, ensuring sufficient space for the locking arm, as described above, makes a compact design difficult. Therefore, ensuring sufficient space affects the overall printer size, limiting the design.

[0010] Therefore, in this technical field, there is a desire for a printing unit and a thermal printer that can reliably lock the pressure roller and can be smoothly released by a small operating force, thereby achieving a compact external size. Summary of the Invention

[0011] According to one aspect of the present invention, a printing unit comprises: a head unit having a thermal head for printing onto recording paper; a pressure plate unit detachably assembled with the head unit and having a pressure plate roller for feeding the recording paper and a pair of pressure plate bearings, the pressure plate bearings rotatably supporting the two ends of the pressure plate roller respectively; an operating lever movable about a rotation axis between a locked position in which the pressure plate unit locks the head unit and an unlocked position in which the pressure plate unit releases the head unit from the head unit; a pressure plate locking mechanism having a locking arm oscillating about a swing axis parallel to the pressure plate roller and switching between a locked state of locking the pressure plate roller and an unlocked state of releasing the lock; and a force-applying member that, in order to maintain the locked state, applies force to the locking arm about the swing axis, and the head unit is formed with a force-applying member for the pair of pressure plate rollers. The bearing can be inserted into a pair of receiving slots through the open opening. When the operating lever is in the locked position, the pair of receiving slots accommodate the pressure plate bearing in a state where the pressure plate bearing is in contact with the bottom of the slot. When the operating lever is in the locked position, the locking arm presses at least one of the pair of pressure plate bearings accommodated in the receiving slots from the open opening side. As the operating lever moves from the locked position to the unlocked position side, the locking arm swings about the swing axis to allow the pressure plate bearing to disengage from the receiving slots through the open opening. An upward push arm is formed in the locking arm. As the operating lever moves from the locked position to the unlocked position, the upward push arm pushes the pressure plate bearing upward from the bottom of the slot towards the open opening side. The force-applying member applies force to the locking arm toward the pressure plate unit side.

[0012] Furthermore, in a printing unit according to one aspect of the invention, as the operating lever moves from the locked position toward the unlocked position, the locking arm swings about the swing axis from the pressure plate unit side toward the head unit side, allowing the pressure plate bearing to disengage from the receiving groove through the opening.

[0013] Furthermore, in one embodiment of the printing unit according to the present invention, when the operating lever is in the locked position, the upper push arm does not contact the pressure plate bearing.

[0014] Furthermore, in a printing unit according to one aspect of the invention, an inclined guide protrusion is formed on the inner side of the receiving groove. The guide protrusion is configured such that the opening width narrows from the open side toward the bottom of the groove, and guides the pressure plate bearing toward the bottom of the groove. The upper push arm pushes the pressure plate bearing upward, causing the roller center of the pressure plate roller to move to the open side compared to the apex of the guide protrusion.

[0015] Furthermore, in a printing unit according to one aspect of the present invention, the locking arms are disposed on both sides of the clamping pressure roller, and are configured as a pair corresponding to a pair of pressure plate bearings, and the pressure plate locking mechanism has a connecting shaft portion extending along the swing axis and connecting the pair of locking arms to each other.

[0016] Furthermore, according to one aspect of the printing unit of the present invention, the unit includes: a fixed blade disposed on one of the head unit and the pressure plate unit; a movable blade disposed on the other of the head unit and the pressure plate unit and capable of moving relative to the fixed blade; and a drive mechanism having a drive rack connected to the movable blade and moving the movable blade between a standby position separated from the fixed blade and a cutting position attached to the fixed blade.

[0017] Furthermore, in a printing unit according to one aspect of the present invention, a return mechanism is provided, which, while the movable blade is stopped in the cutting position, before the pressure plate locking mechanism switches the pressure plate roller to the unlocked state, moves the movable blade from the cutting position to the standby position by an operating force as the operating lever moves from the locked position toward the unlocked position.

[0018] Furthermore, in a printing unit according to one aspect of the present invention, the return mechanism includes: a return rack formed on the drive rack, a return sub-gear meshing with the rack teeth of the return rack, a return gear and a sun gear rotatably supported about the rotation axis in a state coaxially configured with the rotation axis of the operating lever, a planetary gear meshing with the sun gear and revolving with the movement of the operating lever, and an internal gear meshing with the planetary gear, wherein the return gear is capable of meshing with the return sub-gear.

[0019] Furthermore, in a printing unit according to one aspect of the invention, the rack teeth are formed on the opposite side of the tip of the movable blade, such that when the movable blade is in the cutting position, the rack teeth engage with the return gear, and when the movable blade is in the standby position, the rack teeth disengage from the return gear.

[0020] Furthermore, in a printing unit according to one aspect of the present invention, the locking arm has a straight anti-disengagement surface for preventing the pressure plate bearing from disengaging from the receiving groove through the opening in the locked state, and a straight line passing through the center of rotation of the locking arm and the center of the pressure plate bearing intersects the anti-disengagement surface perpendicularly.

[0021] Furthermore, in one embodiment of the printing unit according to the invention, a pressure plate support spring is included to assist in holding the pressure plate bearing within the receiving groove. As the operating lever moves from the locked position to the unlocked position side, the pressure plate support spring moves in the direction of releasing the holding of the pressure plate bearing before the upper push arm pushes the pressure plate bearing, and allows the pressure plate bearing to disengage from the receiving groove through the opening.

[0022] A thermal printer according to one aspect of the present invention includes: the printing unit; a printer body having a recording paper storage portion for receiving the recording paper and having one of the head unit and the pressure plate unit mounted thereon; and a printer cover rotatably connected to the printer body and having the other of the head unit and the pressure plate unit mounted thereon. Attached Figure Description

[0023] Figure 1 This is a perspective view of a thermal printer according to an embodiment of the present invention, and a perspective view showing the printer cover in a closed state.

[0024] Figure 2 yes Figure 1 The image shown is a 3D view of a thermal printer with the printer cover open.

[0025] Figure 3 yes Figure 2 The three-dimensional view of the printed character unit shown.

[0026] Figure 4 It shows from Figure 3 The image shown is a perspective view of the printing unit excluding the gear cover and other components.

[0027] Figure 5 It shows from Figure 4 The image shown is a three-dimensional view of the printing unit excluding the pressure plate frame and other components.

[0028] Figure 6 yes Figure 4 The diagram shows a three-dimensional view of the pressure plate unit.

[0029] Figure 7 From Figure 5 The side view shown in the direction of arrow A is a diagram illustrating the relationship between the receiving groove and the pressure plate bearing.

[0030] Figure 8 It is a perspective view showing the state of cutting the recording paper between the fixed blade and the movable blade.

[0031] Figure 9 From Figure 5 The side view as seen in the direction of arrow A.

[0032] Figure 10 yes Figure 9 The three-dimensional diagrams of the various mechanisms shown.

[0033] Figure 11 Viewed from the opposite side Figure 10 A three-dimensional view of the area surrounding the control lever shown.

[0034] Figure 12 It shows from Figure 11 The image shown is a 3D view excluding the state of the control lever.

[0035] Figure 13 It shows from Figure 10 The image shown is a 3D view excluding the state of the control lever.

[0036] Figure 14 This is a side view showing the periphery of another locking arm.

[0037] Figure 15 It shows from Figure 9 The side view shows the initial state, where a paper jam occurs between the movable and fixed blades.

[0038] Figure 16 It shows from Figure 15 The side view shows the state of the lever being pushed in the locked position.

[0039] Figure 17 It shows from Figure 16 The shown state is a side view of the state in which the control lever is pressed down.

[0040] Figure 18 It shows from Figure 17 The shown state is a side view of the state in which the operating lever is pressed down to the disengaged position.

[0041] Figure 19 It shows from Figure 18 The shown is a side view of the state in which the operating lever is pressed down to return the movable blade to the standby position.

[0042] Figure 20 It shows from Figure 19 The shown is a side view of the state in which the operating lever is further pressed down to the unlocked position, and the pressure plate bearing is pushed up into the opening of the receiving groove.

[0043] Figure 21 This is a diagram illustrating a thermal printer according to another embodiment of the present invention, and is from... Figure 5 The side view as seen in the direction of arrow A.

[0044] Figure 22 It shows from Figure 21 The shown is a side view of the state excluding the locking arm.

[0045] Figure 23 yes Figure 21 The three-dimensional diagrams of the various mechanisms shown.

[0046] Figure 24 It shows from Figure 23 The image shown is a 3D view of the state excluding the locking arm.

[0047] Figure 25 This is a side view showing the periphery of another locking arm in a thermal printer according to another embodiment of the present invention.

[0048] Figure 26 It shows from Figure 25 The shown is a side view of the state excluding the other locking arm.

[0049] Figure 27 yes Figure 25 The three-dimensional diagrams of the various mechanisms shown.

[0050] Figure 28 It shows from Figure 27 The diagram shown is a 3D representation of the state excluding the other locking arm.

[0051] Figure 29 yes Figure 25 An enlarged view of the main part of another locking arm is shown.

[0052] Figure 30 This is a diagram showing a thermal printer according to a modified example of another embodiment of the present invention, and is a perspective view of the main part of the periphery of the operating lever viewed from the inside side.

[0053] Figure 31A This is a partial side view of the main part, viewed from the outer side of the operating lever, showing the first stage (locked state) of a variation of another embodiment of the invention.

[0054] Figure 31B This is observed from the inside of the control lever. Figure 31A The main part of the first stage (locked state) is shown in the side view.

[0055] Figure 32A It shows from Figure 31A The shown is a side view of the main part of the second stage (intermediate state) of the operation of pushing the control lever.

[0056] Figure 32B This is observed from the inside of the control lever. Figure 32A The main part of the second stage (intermediate state) shown is a side view.

[0057] Figure 33A It shows from Figure 32A The shown is a side view of the main part of the third stage (unlocked state) of the operation of pushing the control lever.

[0058] Figure 33B This is observed from the inside of the control lever. Figure 33A The main part of the side view shown in the third stage (unlocked state). Detailed Implementation

[0059] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Figure 1 and Figure 2 As shown, thermal printer 1 is a printer capable of printing on roll-shaped recording paper (thermal paper) P and using the recording paper P as, for example, tickets or receipts.

[0060] A thermal printer 1 is installed in, for example, a shop, and its operation is controlled by an information processing device (not shown). Therefore, the thermal printer 1 is controlled to print various information sent from the information processing device onto recording paper P and output the printed recording paper P.

[0061] The thermal printer 1 is mounted on a surface S, such as that of a shop, and is generally shaped like a cube. In this embodiment, in Figure 1 and Figure 2 In the shown state, the direction perpendicular to the setting surface S is called the up-down direction L1, and the directions orthogonal to each other in the plane parallel to the setting surface S are called the front-back direction L2 and the left-right direction L3. In the front-back direction L2, the front is indicated by arrow FW, and the rear is indicated by arrow BK. Therefore, in Figure 1 and Figure 2 In the center, relative to the paper, the lower left side is the front (FW), and the upper right side is the rear (BK).

[0062] The thermal printer 1 includes: a housing (the printer body according to the present invention) 2, a printer cover 3, and a printing unit 4 consisting of a head unit 5 and a pressure plate unit 6, configured as a so-called forward output type where the recording paper P is output forward (FW). In the illustrated example, the pressure plate unit 6 is provided on the printer cover 3 side, and the head unit 5 is provided on the housing 2 side. However, this is not limited to this case; for example, the head unit 5 may be provided on the printer cover 3 side, and the pressure plate unit 6 may be provided on the housing 2 side.

[0063] The housing 2 is formed into a cubic shape with an opening at the front (FW) by means of synthetic resin material or metal material, or a suitable combination thereof, and has a plurality of outer surfaces 10, including a bottom surface 11 opposite to the mounting surface S. However, the shape of the housing 2 is not limited to this and can be appropriately modified.

[0064] Of the plurality of outer surfaces 10, the outer surface opposite to the bottom surface 11 in the vertical direction L1 is referred to as the top surface 12. Furthermore, of the plurality of outer surfaces 10, the outer surface located on the front FW side is referred to as the front surface 13, and the outer surface located on the rear BK side is referred to as the rear surface 14. These front surfaces 13 and rear surfaces 14 are opposite each other in the front-rear direction L2. Additionally, of the plurality of outer surfaces 10, the outer surfaces opposite each other in the left-right direction L3 are referred to as a pair of side surfaces 15.

[0065] A paper storage section 16, which can hold a roll of paper P through an opening formed on the front surface 13 of the housing 2, is formed inside the housing 2. Thus, when the printer cover 3 is opened, the roll of paper P can be inserted into the paper storage section 16 from the front.

[0066] The printer cover 3 is connected to the lower part of the front surface 13 side of the housing 2 via a rotating shaft 17, and can be opened to close the opening. Furthermore, the printer cover 3 is configured to rotate about the rotating shaft 17 within an angle range of approximately 90 degrees. Figure 1 As shown, the printer is designed such that when the printer cover 3 is closed, a gap exists between the front end of the printer cover 3 and the housing 2. The recording paper P is guided from inside the housing 2 to the front FW and output through this gap. Therefore, this gap functions as the output port 18 for the recording paper P.

[0067] When the printer cover 3 is closed, the housing 2 and printer cover 3, as described above, are locked together with the combination of the pressure plate unit 6 and the head unit 5. Thus, the printer cover 3 is locked in the closed state.

[0068] In addition, such as Figure 1 As shown, in the housing 2, an operating lever 19 for releasing the combination (locking) of the pressure plate unit 6 and the head unit 5 is located at the corner where the front surface 13, the top surface 12, and a side surface 15 intersect. Thus, as... Figure 2 As shown, the printer cover 3 can also be unlocked and opened. For example, the lever 19 can be pressed down.

[0069] Additionally, an operation button 3a, serving as a power button or feed button, is provided on the printer cover 3. The operation button 3a is configured to be pressed down and exposed on the outer surface of the printer cover 3. In the illustrated example, the operation buttons 3a are arranged in a row along the vertical direction L1 below the operation lever 19.

[0070] like Figures 2-5 As shown, the printing unit 4 includes a head unit 5 disposed on the side of the housing 2 and a pressure plate unit 6 disposed on the side of the printer cover 3 and detachably combined with the head unit 5.

[0071] The head unit 5 includes a head frame 20 made of, for example, synthetic resin, forming the basic frame of the head unit 5; a head cover plate 21 made of, for example, metal, combined with the head frame 20 in a manner that covers the head frame 20 from the front (FW) and left and right (L3) directions; and gear covers 22 and 23 made of, for example, metal, combined with the head frame 20 in a manner that covers the head frame 20 from the left and right (L3) directions.

[0072] In addition, the head unit 5 includes at least a thermal head 25, a movable blade 26, a drive mechanism 27, an operating lever 28, a return mechanism 29, and a pressure plate locking mechanism 30. These components, including the thermal head 25, movable blade 26, drive mechanism 27, operating lever 28, return mechanism 29, and pressure plate locking mechanism 30, are mainly mounted using the head frame 20 and are covered by the head cover 21 and gear covers 22 and 23.

[0073] The head unit 5, configured as described above, is installed inside the housing 2. Specifically, the head unit 5 is positioned above the recording paper storage section 16 and closer to the front surface 13 of the housing 2, and is primarily mounted to the housing 2 via a screw connection to the head frame 20. In this embodiment, the head unit 5 is mounted such that the tip 26a of the movable blade 26 faces downward. Furthermore, the head unit 5 will be described in detail later.

[0074] The pressure plate unit 6 includes a pressure plate frame 40, for example made of synthetic resin, forming the basic framework of the pressure plate unit 6, and a pressure plate cover 41, for example made of metal, combined with the pressure plate frame 40 in a manner that covers the pressure plate frame 40 from the front (FW) and from the left and right (L3). Furthermore, the pressure plate unit 6 includes at least pressure plate rollers 45 and fixed blades 46. These pressure plate rollers 45 and fixed blades 46 are primarily mounted using the pressure plate frame 40 and are covered by the pressure plate cover 41.

[0075] The pressure plate unit 6, configured as described above, is mounted on the inner surface of the printer cover 3 via the pressure plate cover 41. At this time, the pressure plate unit 6 is mounted in a position that allows it to be detached from the head unit 5 as the printer cover 3 is opened / closed. In this embodiment, the pressure plate unit 6 is mounted such that the tip 46a of the fixed blade 46 faces upwards.

[0076] The pressure plate unit 6 will be described in detail. For example... Figures 3 to 6 As shown, the fixed blade 46 is supported by the pressure plate frame 40, such that when the head unit 5 and the pressure plate unit 6 are combined, the blade tip 46a faces the head unit 5 side. Figure 6As shown, in the pressure plate frame 40, a pressure plate storage space 47 for storing the pressure plate roller 45 is formed in the portion BK located behind the fixed blade 46, and a support wall 48 for supporting the pressure plate roller 45 is formed. The support wall 48 is configured such that the pressure plate storage space 47 is located therebetween and is opposite to the pressure plate roller 45 in the left-right direction L3.

[0077] The pressure roller 45 is a rubber roller that feeds the recording paper P to the outside of the printer cover 3, and a rubber layer is formed on the pressure shaft 50 extending in the left-right direction L3. The pressure roller 45 is housed in the pressure plate storage space 47 with a portion of its outer peripheral surface exposed to the head unit 5 side, and the pressure roller 45 is rotatably supported by the support wall 48. Specifically, cylindrical pressure plate bearings 51 are respectively covered at both ends of the pressure shaft 50, which extends further outward than the pressure roller 45 in the left-right direction L3. Thus, the pressure roller 45 can be rotated even when a pair of pressure plate bearings 51 are pressed. In addition, a driven gear 52 is fixed at one end of the pressure shaft 50, on the outer side of the left-right direction L3 compared to the pressure plate bearings 51.

[0078] The support wall 48 uses, for example, a slit hole to clamp and fix the pressure plate bearing 51. Thus, the pressure plate roller 45, housed within the pressure plate housing space 47, is rotatably supported by the pair of support walls 48 via the pair of pressure plate bearings 51. When the printer cover 3 is closed, as... Figure 5 As shown, a pair of pressure plate bearings 51 extend outward in the left-right direction L3 compared to the support wall 48, and are respectively housed in a pair of receiving grooves 62 provided on the side of the head unit 5.

[0079] In addition, Figure 5 The main illustration shows the pressure plate roller 45 and pressure plate bearing 51 in the pressure plate unit 6.

[0080] Next, the head unit 5 will be described in detail. For example... Figures 3 to 5 As shown, the head unit 5 includes at least a thermal head 25, a movable blade 26, a drive mechanism 27, an operating lever 28, a return mechanism 29, and a pressure plate locking mechanism 30.

[0081] like Figure 5 As shown, the thermal printhead 25 has multiple heating elements (not shown) arranged in a line along the left-right direction L3, and is mounted to the head frame 20 opposite the pressure roller 45 when the printer cover 3 is in the closed position. Furthermore, the recording paper P can pass between the pressure roller 45 and the thermal printhead 25. A helical spring (not shown) is inserted between the thermal printhead 25 and the head frame 20, which applies force to the thermal printhead 25 towards the pressure roller 45. Thus, the thermal printhead 25 can reliably press against the recording paper P fed by the pressure roller 45, and good printing can be achieved by the printing unit 4.

[0082] The head frame 20 has a pair of sidewall portions 60, 61, which are located outside the support wall 48 of the pressure plate frame 40 in the left-right direction L3 compared to the support wall 48 of the pressure plate unit 6. Each of the sidewall portions 60, 61 forms a pair of receiving grooves 62, into which a pair of pressure plate bearings 51 can be respectively embedded. Figure 7 As shown, the receiving groove 62 is formed in a U-shape in the side view, and is formed with the open opening 62a facing forward (towards the pressure plate unit 6) FW. The bottom 62b of the receiving groove 62 is formed flat. Furthermore, in Figure 7 The illustration shows a receiving groove 62 formed in a sidewall portion 60, and the illustrations of other constituent parts are appropriately omitted.

[0083] An inclined guide protrusion 63 is formed on the inner side of the receiving groove 62. This inclined guide protrusion 63 is formed such that the opening width narrows from the opening 62a side toward the bottom 62b side of the groove, and guides the pressure plate bearing 51 toward the bottom 62b side of the groove. Thus, the receiving groove 62 is formed such that the opening width of the opening 62a is the largest, and the opening width is the narrowest near the apex 63a of the guide protrusion 63. The guide protrusion 63 is formed in the receiving groove 62, so the pressure plate bearing 51 can be guided to fall along the guide protrusion 63 into the bottom 62b side of the groove.

[0084] As described above, receiving grooves 62 are formed on a pair of sidewall portions 60 and 61, respectively. Therefore, when the head unit 5 and the pressure plate unit 6 are combined, as... Figure 5 and Figure 7 As shown, a pair of pressure plate bearings 51 are embedded in a pair of receiving grooves 62, and are in a state of being housed inside. At this time, the pressure plate bearings 51 are housed in the receiving grooves 62 in a state of contact with the bottom 62b of the grooves.

[0085] like Figure 4 As shown, the movable blade 26 is mounted to the head frame 20 via a drive mechanism 27, such that when the head unit 5 and the pressure plate unit 6 are combined, the blade tip 26a faces the pressure plate unit 6. At this time, the movable blade 26 is configured to face the fixed blade 46 in the vertical direction L1, and is configured to overlap with the fixed blade 46 in the front-rear direction L2 when the movable blade 26 moves to the cutting position P1. Figure 8 As shown, the movable blade 26 is a V-shaped plate blade, formed such that its length from the root to the tip 26a gradually decreases from both ends toward the center. Furthermore, Figure 8 This is a perspective view showing the state in which the movable blade 26 is moved to the cutting position P1 and the recording paper P is cut between the fixed blade 46 and the movable blade 26.

[0086] like Figure 4As shown, the movable blade 26 is mounted on the drive rack 71 of the drive mechanism 27 via the movable blade holder 70. The movable blade 26 is configured to move relative to the head frame 20 in the vertical direction L1 by the action of the drive mechanism 27. Thus, the movable blade 26 is movably supported relative to the fixed blade 46 in the vertical direction L1.

[0087] like Figure 4 , Figure 9 and Figure 10 As shown, the drive mechanism 27 moves the movable blade 26 to the cutting position P1 and the standby position P2. The cutting position P1 is where the movable blade 26 rests on the fixed blade 46, so that the movable blade 26 and the fixed blade 46 together cut the recording paper P (see [reference]). Figure 8 The standby position P2 is the position where the movable blade 26 is properly separated from the fixed blade 46 (see [reference]). Figure 4 The drive mechanism 27 includes a drive motor 75, a drive intermediate gear 76, a secondary intermediate gear 77, a drive counter gear 78, and a drive rack 71.

[0088] like Figure 10 As shown, the drive motor 75 is a motor capable of rotating in both forward and reverse directions and is fixed to the inside of a side wall portion 60 of the head frame 20. The drive shaft of the drive motor 75 is connected to the reduction gear 75a. Furthermore, the output shaft 75b of the reduction gear 75a protrudes outward in the left-right direction L3 compared to the side wall portion 60 of the head frame 20. The drive intermediate gear 76 is disposed outward in the left-right direction L3 compared to the side wall portion 60 and is connected to the output shaft 75b of the reduction gear 75a. Therefore, the drive intermediate gear 76 rotates as the drive motor 75 rotates, passing through the reduction gear 75a.

[0089] like Figure 9 and Figure 10 As shown, the secondary intermediate gear 77 is positioned between the drive intermediate gear 76 and the drive secondary gear 78, and is rotatably supported by the intermediate support shaft 80. The secondary intermediate gear 77 includes a large-diameter intermediate gear 77a and a small-diameter intermediate gear 77b, the diameter of which is smaller than that of the large-diameter intermediate gear 77a. When the operating lever 28 is in the locked position P3, the large-diameter intermediate gear 77a meshes with the drive intermediate gear 76. Thus, the entire secondary intermediate gear 77 rotates with the rotation of the drive intermediate gear 76. Furthermore, the small-diameter intermediate gear 77b is positioned outside the large-diameter intermediate gear 77a in the left-right direction L3 and meshes with the drive secondary gear 78.

[0090] The drive secondary gear 78 is configured to be located on the operating lever 28 side and on the drive rack 71 side compared to the small-diameter intermediate gear 77b, and is fixed to the secondary gear support shaft 81 in a coaxial configuration. Thus, the drive secondary gear 78 and the secondary gear support shaft 81 rotate integrally. Furthermore, the drive secondary gear 78 meshes with the small-diameter intermediate gear 77b and also meshes with the drive rack teeth 71a in the drive rack 71.

[0091] like Figure 4 As shown, the drive rack 71 is disposed not only on one side wall 60 of the head frame 20 but also on the other side wall 61, and is positioned on both sides of the head frame 20 in the left-right direction L3, clamping the head frame 20. Furthermore, the secondary gear support shaft 81 is formed to pass through the head frame 20 in the left-right direction L3 and connects a pair of drive secondary gears 78 disposed on both sides of the left-right direction L3. Thus, the pair of drive secondary gears 78 can rotate synchronously via the secondary gear support shaft 81.

[0092] A drive rack 71 is mounted to both ends of the movable blade holder 70 in the left-right direction L3 and extends in the up-down direction L1. Thus, the drive rack 71 is combined with the movable blade 26 via the movable blade holder 70. Drive rack teeth 71a are formed across the entire area of ​​the drive rack 71. A pair of drive counter-gears 78 mesh with these drive rack teeth 71a. Therefore, as the pair of drive counter-gears 78 rotate, the movable blade 26 can move between the standby position P2 and the cutting position P1 via the drive rack 71.

[0093] To facilitate understanding of the configuration, the drive pinion gear 78 and drive rack 71 located on one side wall 60 (drive motor 75 side) will be described in detail below, while the drive pinion gear 78 and drive rack 71 located on the other side wall 61 will be omitted from the description.

[0094] As described above, the drive mechanism 27 is constructed, therefore... Figure 4 and Figure 9 As shown, the drive motor 75 rotates the drive auxiliary gear 78 via the drive intermediate gear 76 and the secondary intermediate gear 77 (large-diameter intermediate gear 77a and small-diameter intermediate gear 77b). Therefore, the drive rack 71 can move together with the return rack 130 (described later in the return mechanism 29) in the direction of arrow F1, and the movable blade 26 can move in the same direction. Thus, the movable blade 26 can move from the standby position P2 to the cutting position P1.

[0095] On the other hand, by reversing the rotation of the drive motor 75, the drive secondary gear 78 can be reversed via the drive intermediate gear 76 and the secondary intermediate gear 77. Therefore, the drive rack 71 can move in the direction of arrow F2 together with the return rack 130, and the movable blade 26 can move in the same direction. Thus, the movable blade 26 can move from the cutting position P1 and return to the standby position P2.

[0096] However, the intermediate support shaft 80 supporting the aforementioned secondary intermediate gear 77 is fixed to a swing plate 90 that is oscillatingly arranged with the secondary gear support shaft 81 as its center. Figure 7 , Figures 9 to 11 As shown, an insertion hole 91 is formed on the swing plate 90, which extends through the swing plate 90 in the left-right direction L3 and into which the auxiliary gear support shaft 81 is inserted. The swing plate 90 is configured to swing along the wall surface of a side wall portion 60 when the auxiliary gear support shaft 81 is inserted into the insertion hole 91.

[0097] The swing plate 90 has a first plate portion 92 extending from the insertion hole 91 toward the space between the drive intermediate gear 76 and the drive rack 71, and a second plate portion 93 extending from the insertion hole 91 toward the swing axis O2 of the locking arm 140 described later.

[0098] The intermediate support shaft 80 is formed to extend outward from the first plate portion 92 in the left-right direction L3. Thus, the secondary intermediate gear 77, supported by the intermediate support shaft 80, can swing around the secondary gear support shaft 81 with the swing plate 90. On the second plate portion 93, a latching protrusion 94 and a locking pin 95 are formed in a manner that protrudes outward in the left-right direction L3.

[0099] In the swing plate 90 configured in this way, the large-diameter intermediate gear 77a of the secondary intermediate gear 77 is always subjected to force in the direction of meshing with the drive intermediate gear 76 by the force applied by the first force-applying member 100. The first force-applying member 100 is, for example, a coil spring, and has a coil portion 100a supported by a coil support shaft 105 protruding from a side wall portion 60, a first coil end 100b snapped to the head frame 20, and a second coil end 100c snapped to a snap-fit ​​protrusion 94 snapped to the swing plate 90.

[0100] Therefore, since the second plate portion 93 is subjected to force (elastic restoring force) towards the operating lever 28 by the force applied by the first force-applying member 100, the swing plate 90 is positioned with the large-diameter intermediate gear 77a pressed against the drive intermediate gear 76. Furthermore, the first force-applying member 100 is not limited to a coil spring, but may also be a leaf spring, for example.

[0101] Furthermore, the swing plate 90 is configured such that, with the operation of the operating lever 28, the engaging pin 95 is pushed upward by the upward cam 113 (described later), thereby resisting the applied force of the first force-applying member 100 and swinging around the secondary gear support shaft 81, thus disengaging the secondary intermediate gear 77 from the drive intermediate gear 76. This disengages the secondary intermediate gear 77 from the drive intermediate gear 76.

[0102] like Figure 4 , Figure 9 and Figure 10 As shown, the operating lever 28 is disposed on one side wall portion 60 of the head frame 20 and is rotatably supported via the lever support shaft 106. The operating lever 28 is configured to push one side wall portion 60 counterclockwise in a side view viewed from the outside of the left-right direction L3, about the lever support shaft 106, from the locked position P3 toward the disengaged position P4 or the unlocked position P5 (described later).

[0103] like Figure 11 As shown, the rod support shaft 106 protrudes from the inner surface of the gear cover 22 toward a side wall portion 60. Furthermore, the central axis of the rod support shaft 106 is the rotation axis O1 of the operating lever 28.

[0104] The locked position P3 is the position where the pressure plate unit 6 remains locked relative to the head unit 5. The disengaged position P4 is the position where the swing plate 90 swings via the upward cam 113 (described later in the operating lever 28) to disengage the large-diameter intermediate gear 77a of the secondary intermediate gear 77 from the drive intermediate gear 76. The unlocked position P5 is the position where the locked state of the pressure plate unit 6 relative to the head unit 5 is released.

[0105] like Figures 9 to 11 As shown, a rod plate 110, which is fan-shaped in the side view, is formed at the base end of the operating lever 28. A planetary shaft 111 protrudes outward in the left-right direction L3 from the outer surface of the rod plate 110. A lever protrusion 112 that engages with the locking arm 140 described later is formed on the inner surface of the rod plate 110. Furthermore, an upward push cam 113 that expands radially outward and a limiting protrusion 114 are formed on the rod plate 110.

[0106] The planetary shaft 111 is formed at a position offset relative to the rod support shaft 106. The push cam 113 is disposed on the clockwise side of the engaging pin 95 formed on the swing plate 90, and the push cam 113 can contact the engaging pin 95 when the operating lever 28 rotates from the locked position P3 to the unlocked position P5. In addition, a latching protrusion 115 is formed on the outer surface of the push cam 113, which protrudes outward in the left-right direction L3.

[0107] The limiting protrusion 114 is disposed on the counterclockwise side of the push-up cam 113. When the operating lever 28 is in the locked position P3, the limiting protrusion 114 contacts the limiting wall portion 116 formed on the head frame 20 from the clockwise side. Therefore, the clockwise rotation of the entire operating lever 28 is limited, thereby positioning it in the locked position P3. Furthermore, when the operating lever 28 moves to the unlocked position P5 and is pushed further rearward, the operating lever 28 can contact the limiting wall portion 116 formed on the head frame 20 from the counterclockwise side. Figure 3 and Figure 11 The gear cover 22 shown is in contact with the limiting wall 117. Therefore, the operation lever 28 is limited from performing a greater degree of downward pressure operation beyond the unlocked position P5.

[0108] The front end of the operating lever 28 is embedded in the connecting body 19a provided in the operating lever 19 of the housing 2 (see...). Figure 2 The inner side of the lever. Thus, the operation lever 28 and the operation lever 19 are operated in conjunction. Thus, by operating the operation lever 19, the operation lever 28 can be operated in conjunction with it from the locked position P3 to the unlocked position P5.

[0109] like Figure 9 and Figure 10 As shown, the operating lever 28 configured as described above is always subjected to the force applied by the second force-applying member 120 in the direction toward the locking position P3 (clockwise). The second force-applying member 120 is, for example, a coil spring, having a coil portion 120a supported by a coil support shaft (not shown) protruding from the inner surface of the gear cover 22, a first coil end 120b snapping onto the inner surface of the gear cover 22, and a second coil end 120c snapping onto a snap-fit ​​protrusion 115 of the operating lever 28.

[0110] Therefore, since the operating lever 28 is subjected to a clockwise force (elastic restoring force) by the second force-applying member 120, the front end of the operating lever 28 is forced toward the locking position P3. Furthermore, as mentioned above, since the limiting protrusion 114 of the operating lever 28 contacts the limiting wall portion 116 of the head frame 20, rotation thereon is restricted and the lever is positioned in the locking position P3. Moreover, the second force-applying member 120 is not limited to a coil spring; for example, it could be a leaf spring.

[0111] like Figure 4 As shown, the return mechanism 29 is a mechanism in which, for example, when the movable blade 26 stops at the cutting position P1 due to a paper jam or the like, before the pressure plate locking mechanism 30 switches the pressure plate roller 45 to the unlocked state, the movable blade 26 is moved from the cutting position P1 to the standby position P2 by the operating force (rotational force) applied to the operating lever 28 from the locked position P3 toward the unlocked position P5.

[0112] like Figures 9 to 12 As shown, the return mechanism 29 includes: a return rack 130 formed on the drive rack 71; a return secondary gear 131 meshing with the rack teeth 130a of the return rack 130; a return gear 132 and a sun gear 133 rotatably supported about the rotation axis O1 in a state coaxially arranged with the rotation axis O1 of the operating lever 28; a planetary gear 134 meshing with the sun gear 133 and revolving with the movement of the operating lever 28; and an internal gear 135 meshing with the planetary gear 134. Furthermore, the sun gear 133, the planetary gear 134, and the internal gear 135 constitute a speed-increasing mechanism 136 (see [link to documentation]). Figure 12 ).

[0113] Furthermore, in this embodiment, the case where the return gear 132 and the sun gear 133 are configured as a single component is an example, but the embodiment is not limited to this case. For example, if the return gear 132 and the sun gear 133 can rotate integrally (can rotate together), they can also be combined after being formed separately.

[0114] The return auxiliary gear 131 is rotatably supported by the auxiliary gear support shaft 81, positioned outside the drive auxiliary gear 78 in the left-right direction L3. Thus, the return auxiliary gear 131 is coaxially arranged with the drive auxiliary gear 78. Furthermore, the return auxiliary gear 131 can mesh with the return gear 132, which rotates in conjunction with the operation of the operating lever 28, and rotates using the rotational force from the return gear 132. Additionally, the return auxiliary gear 131 can mesh with the rack teeth 130a in the return rack 130.

[0115] like Figure 9 and Figure 10 As shown, the return rack 130 is integrally formed with the drive rack 71, positioned outside the drive rack 71 in the left-right direction L3 compared to the drive rack 71 in the drive mechanism 27. The return rack 130 has a plurality of rack teeth 130a. These plurality of rack teeth 130a are not located on the tip 26a side of the movable blade 26, but are formed on the root side of the movable blade 26. Thus, when the movable blade 26 is in the cutting position P1, the return rack 130 meshes with the return auxiliary gear 131, and when the movable blade 26 is in the standby position P2, the meshing of the return rack 130 with the return auxiliary gear 131 is disengaged.

[0116] Furthermore, in the illustrated example, the drive rack 71 and the return rack 130 are integrally formed, but this is not a limitation; the return rack 130 and the drive rack 71 may also be formed separately. However, by integrally forming the drive rack 71 and the return rack 130, the return rack 130 can be included without increasing the number of parts, thus simplifying the structure and reducing costs, which is preferable.

[0117] Among the multiple rack teeth 130a, the rack tooth 130a located on the side of the tip 26a of the movable blade 26 is a displaceable rack tooth 130b. This rack tooth 130b is formed at the front end of the rack arm 139. The base end of the rack arm 139 is connected to the end of the drive rack 71 located on the side of the tip 26a of the movable blade 26. Therefore, the rack arm 139 is a cantilever, which can elastically deform in the direction of separation from the return gear 131 with the base end as a fulcrum. Thus, the rack arm 139 can elastically deform in the direction of separation from the return gear 131, and the rack tooth 130b can retract radially outward from the return gear 131.

[0118] To simplify the explanation of why the rack teeth 130b of the return rack 130 are formed to retract radially outward from the return auxiliary gear 131, consider, for example, the case where the return rack 130 moves along... Figure 9 When moving in the direction of arrow F1, the rack tooth 130b of the return rack 130 abuts against the tip of the tooth of the return auxiliary gear 131. In this case, the movement of the return rack 130 may be blocked by the tip of the tooth of the return auxiliary gear 131. Considering this situation, by forming the rack tooth 130b at the front end of the rack arm 139, the rack tooth 130b retracts radially outward of the return auxiliary gear 131 by the elastic deformation of the rack arm 139, and can be configured to pass over the tip of the tooth of the return auxiliary gear 131. Therefore, after the rack tooth 130b passes over the tip of the tooth of the return auxiliary gear 131, the rack tooth 130b returns to its original position by the elastic restoring force of the rack arm 139, and the returned rack tooth 130b can properly mesh with the next tooth of the return auxiliary gear 131. Thus, the rack teeth 130b of the return rack 130 and the return auxiliary gear 131 can mesh properly without causing any adverse effects that hinder the movement of the return rack 130.

[0119] like Figure 9 and Figure 10 As shown, the return gear 132 is positioned outside the lever plate 110 in the left-right direction L3 compared to the lever plate 110 in the operating lever 28, and is rotatably supported by the lever support shaft 106. Thus, the return gear 132 is coaxially arranged with the rotation axis O1 of the operating lever 28.

[0120] The return gear 132 includes a gear plate 132a and a plurality of gear teeth 132b formed along the outer peripheral edge of the gear plate 132a. The plurality of gear teeth 132b are not formed on the entire circumference of the gear plate 132a, but rather over approximately half the circumference of the gear plate 132a. These plurality of gear teeth 132b can mesh with the return auxiliary gear 131.

[0121] Among the multiple gear teeth 132b, the gear tooth 132b that first meshes with the return auxiliary gear 131 can be moved radially inward toward the return gear 132 by operating the operating lever 28 from the locked position P3 toward the unlocked position P5, and can be retracted from the teeth of the return auxiliary gear 131.

[0122] Gear teeth 132b are formed at the front end of the elastic arm 132c. The base end of the elastic arm 132c is integrally formed with the portion of the outer peripheral edge of the gear plate 132a where gear teeth 132b are not formed, and the elastic arm 132c extends clockwise in an arc shape along the outer peripheral edge of the gear plate 132a. Thus, the elastic arm 132c is cantilevered on the outer peripheral edge of the gear plate 132a by its base end, and can be elastically deformed radially with its base end as a fulcrum. Thus, by elastically deforming the elastic arm 132c toward the gear plate 132a, the gear teeth 132b can be displaced radially inward toward the return gear 132, and can retract from the teeth of the return auxiliary gear 131.

[0123] like Figure 12 As shown, the sun gear 133 is integrally formed on the inner surface of the gear plate 132a and is coaxially arranged with the rotation axis O1 of the operating lever 28. Thus, the sun gear 133 can rotate together with the return gear 132 about the rotation axis O1.

[0124] Planetary gear 134, in its meshing state with sun gear 133, is rotatably supported by operating lever 28 via planetary shaft 111. Thus, when operating lever 28 rotates around rotation axis O1, planetary gear 134 revolves around rotation axis O1, following the movement of operating lever 28. Internal gear 135, meshing with planetary gear 134, is formed on the inner surface of gear cover 22. Therefore, planetary gear 134 revolves with the movement of operating lever 28, and can rotate on its own axis while meshing with internal gear 135.

[0125] Thus, through the rotation of the planetary gear 134, the sun gear 133 and the return gear 132 can rotate around the rotation axis O1, and the gear teeth 132b of the return gear 132 can mesh with the return auxiliary gear 131.

[0126] like Figure 5As shown, the pressure plate locking mechanism 30 has locking arms 140 and 150 that can swing around a swing axis O2 parallel to the pressure plate roller 45, and is a mechanism for switching the locked state of locking the pressure plate roller 45 and the unlocked state of unlocking the lock.

[0127] like Figure 5 , Figure 9 as well as Figure 10 As shown, a locking arm 140 is disposed on one side wall 60 of the head frame 20, and another locking arm 150 is disposed on the other side wall 61. When the operating lever 28 is in the locked position P3, the pair of locking arms 140, 150 press the pressure plate bearing 51 housed in the receiving groove 62 from the open side 62a. As the operating lever 28 moves from the locked position P3 toward the unlocked position P5, the pair of locking arms 140, 150 swing about the swing axis O2 from the pressure plate unit 6 toward the head unit 5 and separate from the pressure plate bearing 51 to allow the pressure plate bearing 51 to disengage from the receiving groove 62.

[0128] Therefore, the pressure plate locking mechanism 30 of this embodiment can simultaneously lock a pair of pressure plate bearings 51 using a pair of locking arms 140, 150, and can simultaneously unlock them.

[0129] One locking arm 140 and another locking arm 150 are connected by a connecting shaft 141 extending along a long strip in the left-right direction L3. The connecting shaft 141 is as follows... Figure 10 The cylindrical shaft shown is formed to pass through the head frame 20 in the left-right direction L3 and is rotatably supported by one side wall portion 60 and another side wall portion 61. Furthermore, the central axis of the connecting shaft portion 141 is the swing axis O2.

[0130] Furthermore, one locking arm 140 and the other locking arm 150 are respectively connected to the two ends of the connecting shaft 141. Thus, one locking arm 140 and the other locking arm 150 can swing synchronously around the swing axis O2 through the connecting shaft 141.

[0131] Furthermore, the connecting shaft portion 141 is configured to be located between the receiving groove 62 and the return gear 132 in the vertical direction L1, and to be located behind the receiving groove 62 by BK in the front-rear direction L2.

[0132] Furthermore, this embodiment takes as an example a pair of locking arms 140, 150 arranged in the left-right direction L3 that are swayably connected to each other via a connecting shaft 141, but is not limited to this case. For example, the pair of locking arms 140, 150 and the connecting shaft 141 may also be integrally formed by bending a metal plate, etc., and thus constituted by a single component.

[0133] A locking arm 140 will be described in detail. For example... Figure 13 As shown, the locking arm 140 is positioned above the receiving groove 62 and is formed to extend in the front-rear direction L2. The base end of the locking arm 140 is connected to the end of the connecting shaft portion 141. At the front end of the locking arm 140, a locking pawl portion 145 is formed, which covers the pressure plate bearing 51 received within the receiving groove 62 from the opening 62a side of the receiving groove 62. Thus, the pressure plate bearing 51 can be held such that it is clamped between the locking pawl portion 145 and the bottom 62b of the groove in the receiving groove 62.

[0134] Furthermore, the outer surface of the locking claw portion 145 is an inclined guide surface 145b, which guides the pressure plate bearing 51 into the receiving groove 62 when the pressure plate bearing 51 is placed in the receiving groove 62. The guide surface 145b is formed to form a V-shaped groove in the side view between itself and the guide protrusion 63 on the side of the receiving groove 62.

[0135] Furthermore, a locking wall portion 146 is formed at the base end of the locking arm 140, protruding outward in the left-right direction L3. When the operating lever 28 is operated from the locked position P3 toward the unlocked position P5, after the upward cam 113 swings the swing plate 90 via the locking pin 95, the locking wall portion 146 serves as a wall portion that contacts the lever protrusion 112 of the operating lever 28.

[0136] Thus, the entire locking arm 140 is pressed by the lever protrusion 112 via the engaging wall portion 146 as the operating lever 28 is operated, and is configured to swing clockwise around the swing axis O2. In other words, the locking arm 140 is configured to swing upwards around the swing axis O2, from the pressure plate unit 6 side towards the head unit 5 side. Therefore, the locking claw portion 145 of the locking arm 140 gradually separates from the pressure plate bearing 51 as the operating lever 28 is operated, and when the operating lever 28 reaches the unlocked position P5, the locking claw portion 145 retracts from the receiving groove 62 back to the head unit 5 side, opening the opening 62a. This allows the pressure plate bearing 51 to disengage from the receiving groove 62.

[0137] Furthermore, an upward push arm 147 is formed on the locking arm 140. This upward push arm 147 moves the pressure plate bearing 51 from the bottom 62b of the receiving groove 62 toward the opening 62a side as the operating lever 28 moves from the locked position P3 toward the unlocked position P5. The upward push arm 147 is positioned rearward BK relative to the bottom 62b of the groove and is formed to extend downward from the locking arms 140 and 150. In the upward push arm 147, the surface facing the pressure plate bearing 51 is formed to extend parallel to the bottom 62b of the groove and serves as the pushing surface 147a for pushing the pressure plate bearing 51 upward.

[0138] Furthermore, when the operating lever 28 is in the locked position P3, a gap is ensured between the pushing surface 147a and the pressure plate bearing 51. Thus, when the operating lever 28 is in the locked position P3, the upper push arm 147 is in standby without contacting the pressure plate bearing 51.

[0139] In particular, the upward push arm 147 is longer and more rectangular downwards, so when the pressure plate bearing 51 is pushed upwards in the receiving groove 62, the pressure plate bearing 51 can be pushed significantly upwards toward the opening 62a. Specifically, the pressure plate bearing 51 can be pushed upwards such that the center of the pressure plate roller 45 moves to the side of the opening 62a relative to the apex 63a of the guide protrusion 63 formed in the receiving groove 62.

[0140] As described above, the locking arm 140 is subjected to force on another locking arm 150 located on the other side wall portion 61 of the head frame 20 (see...). Figure 5 The force is applied to the locking arm 140 in a counterclockwise direction toward the pressure plate unit 6. Therefore, the locking pawl 145 is always under force, so that the locking pawl 145 is in a position that covers the pressure plate bearing 51 from the opening 62a side.

[0141] Next, we will refer to Figure 14 The other locking arm 150 is described. However, the other locking arm 150 is constructed in essentially the same way as the locking arm 140, so the same reference numerals are assigned to the same configuration and its description is omitted.

[0142] like Figure 14 As shown, a latching protrusion 151 is formed on the other locking arm 150, which protrudes outward in the left-right direction L3. Moreover, the locking arm 150 is always subjected to the force of the third force-applying member (the force-applying member involved in the present invention) 160, so that the locking claw portion 145 is in a position that covers the pressure plate bearing 51 from the opening 62a side.

[0143] The third force-applying member 160 is, for example, a helical spring, and has a coil portion 160a supported by a coil support shaft (not shown), a first coil end 160b snapping into the head frame 20, and a second coil end 160c snapping into a snap protrusion 151 snapping into the locking arm 150. The coil support shaft protrudes from the inner surface of another gear cover 23.

[0144] Therefore, in Figure 14 In the indicated state, the locking arm 150 is subjected to a clockwise force by the force applied by the third force-applying member 160 (elastic restoring force). Thus, in Figure 13 In the illustrated state, a locking arm 140 is subjected to a counterclockwise force. Furthermore, the third force-applying member 160 is not limited to a coil spring; for example, it could be a leaf spring.

[0145] In addition, such as Figure 5As shown, in this embodiment, when the pressure plate unit 6 is combined with the head unit 5, the driven gear 52 is positioned outside the other locking arm 150 in the left-right direction L3. The driven gear 52 can mesh with a pressure plate gear train mechanism (not shown) disposed on the other side wall 61 of the head frame 20. The pressure plate gear train mechanism operates by receiving power from a drive motor (not shown) for driving the pressure roller 45, and transmits this power to the driven gear 52. Thus, when the head unit 5 and the pressure plate unit 6 are combined, the pressure roller 45 can be rotated to feed the recording paper P.

[0146] Next, the function of the thermal printer 1 configured as described above will be explained. First, the configuration of the head assembly unit 5 and the pressure plate unit 6 will be explained. In this case, as... Figure 2 As shown, after placing the roll of recording paper P into the recording paper storage section 16 of the housing 2 and closing the operating printer cover 3, the pressure plate unit 6 can be brought close to the head unit 5. Furthermore, as... Figure 1 As shown, by fully closing the printer cover 3, the head unit 5 and the pressure plate unit 6 can be combined with the recording paper P held between the thermal head 25 and the pressure plate roller 45.

[0147] Furthermore, as the printer cover 3 is closed, the pressure plate bearing 51 of the pressure roller 45 is guided by the guide protrusion 63 of the receiving groove 62 and the guide surface 145b of the locking claw portion 145, and is received in the receiving groove 62. At this time, the pressure plate bearing 51 resists the applied force of the third force-applying member 160, and is slightly pushed open by the locking claw portion 145 while being received in the receiving groove 62.

[0148] After being pressed by the pressure plate bearing 51, the locking arms 140 and 150 swing around the swing axis O2 by the force applied by the third force-applying member 160 to return to their original positions, and press the pressure plate bearing 51 from the opening 62a side of the receiving groove 62 using the locking claw 145. Thus, as Figure 5 As shown, a pair of locking arms 140 and 150 can press down on a pair of pressure plate bearings 51 housed in a pair of receiving grooves 62, thus preventing the pressure plate bearings 51 from sliding out of the receiving grooves 62. Therefore, the pressure plate locking mechanism 30 can be used to keep the pressure plate roller 45 in a locked state.

[0149] This allows for locking the combination of the head unit 5 and the pressure plate unit 6, and also for locking the printer cover 3 onto the housing 2. Furthermore, by combining the head unit 5 and the pressure plate unit 6, the thermal head 25 and the pressure roller 45 press against each other with a predetermined pressure while holding the recording paper P between them. Additionally, after the recording paper P passes between the movable blade 26 and the fixed blade 46, it is guided from the output port 18 to the outside of the housing 2. Furthermore, the driven gear 52 of the pressure roller 45 meshes with the pressure plate wheel mechanism on the head unit 5 side.

[0150] Next, the printing of various information on the recording paper P will be briefly described. In this case, the drive motor is driven, and the driven gear 52 rotates via the pressure plate gear train mechanism. This causes the pressure roller 45 to rotate, and the recording paper P, held between the pressure roller 45 and the thermal head 25, can be fed towards the output port 18. Simultaneously, a control signal corresponding to the printing data is output to the thermal head 25, causing the heating element to heat up appropriately. This allows various characters, graphics, etc., to be clearly printed on the fed recording paper P. Furthermore, the printed recording paper P passes between the fixed blade 46 and the movable blade 26.

[0151] Next, the case of cutting the recording paper P will be briefly described. In this case, the drive motor 75 is driven to... Figure 9 The drive intermediate gear 76 shown rotates. This causes the drive auxiliary gear 78 to rotate via the secondary intermediate gears 77 (large-diameter intermediate gear 77a and small-diameter intermediate gear 77b), and the drive rack 71 can move together with the return rack 130 in the direction of arrow F1. Therefore, the movable blade 26 can move from the standby position P2 to the cutting position P1, and as shown... Figure 8 The recording paper P can be clamped between the movable blade 26 and the fixed blade 46 and cut. As a result, the cut recording paper P can be used as, for example, a receipt or ticket.

[0152] Furthermore, after the recording paper P is cut, the drive motor 75 rotates in the reverse direction. This allows the drive secondary gear 78 to rotate in the reverse direction via the drive intermediate gear 76 and the secondary intermediate gear 77, and so on. Figure 9 As shown, the drive rack 71 can move together with the return rack 130 in the direction of arrow F2. Therefore, the movable blade 26 can move from the cutting position P1 to the standby position P2 and then return.

[0153] Furthermore, when the recording paper P is cut, the return counter-gear 131 is disengaged from the gear teeth 132b in the return gear 132, and is allowed to idle. Therefore, when the movable blade 26 moves to the cutting position P1, even if the rack teeth 130a and 130b of the return rack 130 are engaged with the return counter-gear 131, the return counter-gear 131 can still idle. Thus, the drive rack 71 and the return rack 130 can be moved without being affected by the return counter-gear 131, and the recording paper P can be cut.

[0154] Next, a series of operations will be explained in the following situation: when a paper jam occurs between the movable blade 26 and the fixed blade 46, the paper jam is cleared by operating the operating lever 28, and the pressure plate unit 6 is unlocked to open the printer cover 3. Furthermore, in the case of a paper jam during the cutting of the recording paper P, as... Figure 15 As shown, the movable blade 26 will be stopped at the cutting position P1, where the movable blade 26 rests on the fixed blade 46.

[0155] In this case, such as Figure 15 As shown, the operating lever 28 operates from the locked position P3 toward the unlocked position P5 against the applied force of the second force-applying member 120. Consequently, the operating lever 28 can rotate counterclockwise around the rotation axis O1, and the planetary gear 134, meshing with the internal gear 135, can revolve counterclockwise around the rotation axis O1 as the operating lever 28 moves, while simultaneously rotating clockwise around the planetary shaft 111. Furthermore, the sun gear 133 and the return gear 132 can rotate counterclockwise around the rotation axis O1 as the planetary gear 134 rotates.

[0156] like Figure 16 As shown, when the operating lever 28 rotates counterclockwise, the upward-pushing cam 113 contacts the engaging pin 95, and external force is applied to the swing plate 90 through the engaging pin 95. Therefore, as... Figure 17 As shown, through further operation of the operating lever 28, the swing plate 90 can be pushed up by the push cam 113, and the swing plate 90 can resist the applied force of the first force-applying member 100 and swing clockwise around the secondary gear support shaft 81.

[0157] Therefore, the secondary intermediate gear 77 mounted on the swing plate 90 can be disengaged from the drive intermediate gear 76, and the meshing between the secondary intermediate gear 77 and the drive intermediate gear 76 can be released. Thus, the position of the operating lever 28 at this time corresponds to the disengaged position P4.

[0158] Furthermore, since the sun gear 133 and the return gear 132 rotate counterclockwise as the swing plate 90 swings and the operating lever 28 is operated, therefore, as Figure 17 As shown, the first gear tooth 132b of the return gear 132 can engage with the return auxiliary gear 131 at the moment when the meshing of the secondary intermediate gear 77 and the drive intermediate gear 76 is disengaged. As a result, the return auxiliary gear 131 can rotate clockwise.

[0159] Therefore, by means of Figure 17 As shown, further operate the operating lever 28 from the disengaged position P4 toward the unlocked position P5, such as... Figure 18 and 19 As shown, the remaining gear teeth 132b of the return gear 132 can sequentially mesh with the return auxiliary gear 131, and the return auxiliary gear 131 can continue to rotate clockwise. Therefore, the return rack 130, which meshes with the return auxiliary gear 131, can move in the direction of arrow F2, and can force the movable blade 26 to return from the cutting position P1 to the standby position P2. This eliminates the overlap between the movable blade 26 and the fixed blade 46, and removes paper jams.

[0160] Furthermore, when the movable blade 26 returns to the standby position P2 via the return auxiliary gear 131, the drive rack 71 also moves together with the return rack 130, causing the drive auxiliary gear 78 to rotate. At this time, as mentioned earlier, since the meshing of the secondary intermediate gear 77 and the drive intermediate gear 76 is disengaged, the drive auxiliary gear 78 and the secondary intermediate gear 77 meshing with the drive auxiliary gear 78 can idle separately. Therefore, the movable blade 26 can return to the standby position P2 without being affected by the drive auxiliary gear 78 and the secondary intermediate gear 77.

[0161] Furthermore, when the movable blade 26 returns to the standby position P2, such as Figure 19 As shown, the rack teeth 130a and 130b of the return rack 130 are disengaged from the return auxiliary gear 131. Therefore, during the stage of returning the movable blade 26 to the standby position P2 to clear the paper jam, the meshing of the rack teeth 130a and 130b of the return rack 130 with the return auxiliary gear 131 can be disengaged.

[0162] In addition, such as Figure 19 As shown, when the movable blade 26 returns to the standby position P2, the lever protrusion 112 of the operating lever 28 contacts the engaging wall 146 of a locking arm 140, and an external force is applied to the locking arm 140 through the engaging wall 146. This allows the locking arm 140 to be pushed upwards, and the locking arm 140 can swing about the swing axis O2 from the pressure plate unit 6 side towards the head unit 5 side, resisting the force applied by the third force-applying member 160. Therefore, the locking claw 145 can gradually separate from the pressure plate bearing 51 as the locking arm 140 swings.

[0163] Moreover, such as Figure 20As shown, by further operating the operating lever 28 to move it to the unlocked position P5, the locking arm 140 can retract from the receiving groove 62 back to the head unit 5 side, and the locking claw 145 can significantly separate from the pressure plate bearing 51 to open the opening 62a. Thus, the pressure plate bearing 51 can be allowed to disengage from the receiving groove 62.

[0164] In addition, the movement linkage with the aforementioned locking arm 140, such as Figure 20 As shown, using the push arm 147, the pressure plate bearing 51 can be pushed upwards from the bottom 62b of the receiving groove 62 toward the opening 62a. Specifically, when the operating lever 28 reaches the unlocked position P5, as... Figure 20 As shown, the upper push arm 147 can push the pressure plate bearing 51 upward, so that the center of the pressure plate roller 45 can be moved to the side of the opening 62a compared with the apex 63a of the guide protrusion 63.

[0165] Furthermore, since the other locking arm 150 operates synchronously with the first locking arm 140 via the connecting shaft 141, it can operate in the same manner as described above. Therefore, by placing the operating lever 28 in the unlocked position P5, the pressure plate locking mechanism 30 can be used to switch the pressure plate roller 45 to the unlocked state, and the head unit 5 can be separated from the pressure plate unit 6. As a result, the printer cover 3 on which the pressure plate unit 6 is mounted can be opened.

[0166] As explained above, the printing unit 4 and thermal printer 1 according to this embodiment can reliably lock the pressure plate roller 45 because the locking arms 140 and 150 can prevent the pressure plate bearing 51 from disengaging from the receiving groove 62. Moreover, since the locking arms 140 and 150 are forceped by the third force-applying member 160 to maintain the locked state, it is possible to prevent the locking state from being released due to unnecessary swinging around the swing axis O2.

[0167] Furthermore, in conjunction with the operation of the operating lever 28, not only do the locking arms 140 and 150 retract from the receiving groove 62, but the push arm 147 also forces the pressure plate bearing 51 upward toward the opening 62a. Therefore, the pressure plate roller 45 can disengage from the receiving groove 62 without being affected by the force applied by the third force-applying member 160. Consequently, the locking of the pressure plate roller 45 can be released with minimal operating force, without requiring excessive force to operate the operating lever 28, allowing for smooth separation of the head unit 5 and the pressure plate unit 6.

[0168] Furthermore, when the pressure roller 45 is released from its lock, unlike in the past, since the locking arms 140 and 150 swing from the pressure plate unit 6 side toward the head unit 5 side, it is not necessary to ensure a movable space for the locking arms 140 and 150 to move on the pressure plate unit 6 side. Therefore, the pressure plate unit 6 can be correspondingly miniaturized and thinned, and the overall external dimensions of the printing unit 4 can be made compact.

[0169] Furthermore, since the locking arms 140 and 150 press the pressure plate bearing 51, it is difficult to produce the so-called one-sided fastening (one-sided upward) defect, that is, it is difficult for one pressure plate bearing 51 to be locked while the other pressure plate bearing 51 is not locked or is not locked sufficiently. Therefore, there is no need to add mechanisms to prevent one-sided fastening, etc., and the design can be simplified. In addition, since the locking arms 140 and 150 and the push arm 147 are integrally formed into one component, the number of components can be reduced, and the structure can be simplified.

[0170] Furthermore, when the upper push arm 147 pushes the pressure plate bearing 51 upward, the upper push arm 147 forcefully pushes the pressure plate bearing 51 upward, causing the roller center of the pressure plate roller 45 to move to the side of the opening 62a compared to the apex 63a of the guide protrusion 63. Therefore, the pressure plate bearing 51 can be pushed upward to near the opening 62a in the receiving groove 62 and can be transferred to a nearly disengaged state, thus making it easier to separate the head unit 5 and the pressure plate unit 6.

[0171] Furthermore, due to the return mechanism 29, even if a paper jam occurs between the fixed blade 46 and the movable blade 26, and the movable blade 26 stops at the cutting position P1 due to the paper jam, the pressure roller 45 can be released after the paper jam is cleared by operating the lever 28. Therefore, the printing unit 4 and the thermal printer 1 can be made very easy to use. In particular, when the lever 28 is operated from the locked position P3 to the unlocked position P5, the paper jam clearance and the unlocking of the pressure roller 45 can be performed in a series of steps, thus making the printing unit 4 and the thermal printer 1 even easier to use.

[0172] Furthermore, due to the speed-increasing mechanism 136 utilizing the planetary gear 134, the rotation amount of the return gear 132 can be ensured to be relatively large relative to the operating stroke of the operating lever 28. Therefore, even with the operating stroke of the operating lever 28 suppressed to a smaller extent, the rotation amount of the return gear 132 required to return the movable blade 26 to the standby position P2 can be ensured. This effectively ensures the operability of the operating lever 28.

[0173] Furthermore, in the return gear 132 of this embodiment, the gear teeth 132b that initially mesh with the return auxiliary gear 131 can retract to the radially inner side of the return gear 132. Therefore, the gear teeth 132b can mesh with the return auxiliary gear 131 more reliably.

[0174] Let me briefly explain this point. For example, considering... Figure 17As shown, when the gear tooth 132b of the return gear 132 meshes with the return auxiliary gear 131, the tip 131a of the auxiliary gear tooth of the return auxiliary gear 131 abuts against the tip of the gear tooth 132b, thus the rotation of the return gear 132 may be hindered by the return auxiliary gear 131. However, even in this case, through the elastic deformation of the elastic arm 132c, the gear tooth 132b can retract radially inward toward the return gear 132. Thus, as the return gear 132 rotates, the gear tooth 132b can move past the tip 131a of the auxiliary gear tooth. Therefore, after passing the tip 131a of the auxiliary gear tooth, the gear tooth 132b can return from the retracted position to its original position using the elastic restoring force of the elastic arm 132c. Therefore, the gear tooth 132b can mesh with the next auxiliary gear tooth.

[0175] Next, another embodiment of the present invention will be described based on the accompanying drawings. Furthermore, in this embodiment, the same components as in the above embodiments are given the same reference numerals, and their descriptions are omitted. Therefore, the differences from the above embodiments will be mainly described here.

[0176] Figures 21 to 24 A side view of a thermal printer according to another embodiment of the present invention is shown. Specifically, Figure 21 This is a diagram illustrating a thermal printer according to another embodiment of the present invention, and is from... Figure 5 The side view taken in the direction of arrow A shown. Figure 22 It shows from Figure 21 The shown is a side view of the state excluding the locking arm. Figure 23 yes Figure 21 The three-dimensional diagrams of the various mechanisms shown. Figure 24 It shows from Figure 23 The image shown is a 3D view of the state excluding the locking arm.

[0177] in addition, Figures 25 to 29 Another side view of the thermal printer according to another embodiment of the present invention is shown. Specifically, Figure 25 This is a side view showing the periphery of another locking arm in a thermal printer according to another embodiment of the present invention. Figure 26 It shows from Figure 25 The shown is a side view of the state excluding the other locking arm. Figure 27 yes Figure 25 The three-dimensional diagrams of the various mechanisms shown. Figure 28 It shows from Figure 27 The diagram shown is a 3D representation of the state excluding the other locking arm. Figure 29 yes Figure 25 An enlarged view of the main part of the locking arm shown.

[0178] like Figures 21 to 24 As shown, a surrounding wall 170 is erected on a side wall portion 60 of the head frame 20 to surround the periphery except for the meshing portion of the drive intermediate gear 76. On the other hand, a shaft portion, not shown but conforming to the shape of the surrounding wall 170, is formed on the inner surface of the gear cover 22 mounted on the side wall portion 60 at a position corresponding to the surrounding wall 170. Therefore, when the gear cover 22 is mounted on the side wall portion 60, positioning accuracy can be improved.

[0179] Furthermore, the locking claw portion 145A of the pair of locking arms 140A and 150A involved in this embodiment has a different shape than the locking claw portion 145 of the locking arms 140 and 150 in the above embodiment. For example Figure 29 As shown, the locking claw portion 145A has a straight anti-disengagement surface 148A, which prevents the pressure plate bearing 51 from disengaging from the receiving groove 62 through the opening 62a in the locked state. Furthermore, a line L1 passing through the center of rotation O3 of the locking arm 150A and the center of the pressure plate bearing 51 intersects the anti-disengagement surface 148A (S1) perpendicularly. The shape characteristics of the locking claw portion 145A are also present in the locking arm 140A.

[0180] As described above, the pressure plate locking mechanism 30 in this embodiment is configured such that a straight line passing through the center O2 of the pressure plate bearing 51 from the rotation center of the locking arms 140A and 150A is perpendicular to the bearing retaining surface S1 formed on the locking claw portion 145A of the locking arms 140A and 150A. Therefore, even if the pressure plate roller 45 is pulled by an external force in the direction of disengagement from the receiving groove 62 when it is in the locked state, no force will be generated that would cause the locking arms 140A and 150A to move in the release direction (i.e., the direction of separation from the pressure plate bearing 51), thereby suppressing the disengagement of the pressure plate roller 45.

[0181] Furthermore, the left and right sidewall portions 60 and 61 in this embodiment are equipped with pressure plate support springs 180 and 190, which are made of wire springs or the like. The pressure plate support springs 180 and 190 are force-applying members that help to hold the pressure plate bearing 51 within the receiving groove 62.

[0182] like Figures 21 to 24 As shown, a pressure plate support spring 180 is disposed between a side wall portion 60 and a locking arm 140A. A mountain-shaped bearing pressing portion 181 is formed at one end of the pressure plate support spring 180, which presses in a direction that prevents the pressure plate bearing 51 in the receiving groove 62 from disengaging. The other end of the pressure plate support spring 180 is bent around the connecting shaft portion 141, and the other end 182 is snapped onto the side wall portion 60 by a snap-fit ​​portion 171 formed on the side wall portion 60.

[0183] like Figures 25 to 29As shown, the pressure plate support spring 190 is disposed between another side wall portion 61 and the locking arm 150A. A mountain-shaped bearing pressing portion 191 is formed on one end of the pressure plate support spring 190, which presses in a direction that prevents the pressure plate bearing 51 in the receiving groove 62 from disengaging. The other end of the pressure plate support spring 190 is bent around the connecting shaft portion 141, and the other end 192 is snapped into the side wall portion 61 through a snap-fit ​​hole 172 formed in the side wall portion 61.

[0184] With the pressure plate support springs 180 and 190 configured as described above, the bearing pressing portions 181 and 191 always apply force to the pressure plate bearing 51 in the receiving groove 62 towards the bottom 62b of the groove to assist in holding the pressure plate roller 45. Therefore, even in the locked state, if there is a gap between the anti-disengagement surface 148A of the locking arms 140A and 150A and the pressure plate bearing 51, the loosening caused by this gap can be absorbed, thus holding the pressure plate bearing 51. As a result, a margin can be provided in the design tolerance of the locking arms 140A and 150A, and smooth swinging of the locking arms 140A and 150A can be achieved, as well as reliable prevention of disengagement of the pressure plate bearing 51 by the anti-disengagement surface 148A. Furthermore, since the bearing pressing portions 181 and 191 of the pressure plate support springs 180 and 190 are formed in a mountain shape, the disengagement action of the pressure plate roller 45 is not unnecessarily hindered when it is disengaged.

[0185] Next, a variation of another embodiment of the present invention will be described based on the accompanying drawings. In this variation, the same reference numerals are used for components identical to those in the above embodiment, and their descriptions are omitted; the differences from the above embodiment will be mainly explained. Specifically, as the operating lever 28 moves from the locked position P3 to the unlocked position P5, the pressure plate support spring 180 on the operating lever 28 side swings in the direction of releasing the holding of the pressure plate bearing 51, thereby allowing the pressure plate bearing 51 to disengage from the receiving groove 62 through the opening 62a.

[0186] Figure 30 This is a diagram showing a modified example of a thermal printer according to another embodiment of the present invention, and is a perspective view of the main part of the periphery of the operating lever viewed from the inside side. Furthermore, in Figure 30 In this embodiment, some parts have been omitted for ease of observation, but these omitted parts actually exist in the same way as in the above embodiment.

[0187] like Figure 30As shown, a boss-shaped protrusion 96 is formed on the inner surface of the swing plate 90. When the swing plate 90 swings, one end 183 of the pressure plate support spring 180 abuts against the protrusion 96. Therefore, when the swing plate 90 swings by pressing down the operating lever 28, one end 183 of the pressure plate support spring 180 and the bearing pressing part 181 are pushed upward in conjunction with the swing plate 90 to the opposite side of the pressure plate bearing 51. This series of actions will be described based on Figures 31 to 33. Furthermore, in these Figures 31 to 33, some parts have been omitted for ease of observation to show the different configuration from the above embodiment, but these omitted parts actually exist in the same way as in the above embodiment.

[0188] Figure 31A This is a partial side view of the main part of the operating lever 28, showing the first stage (locked state) in a variation of another embodiment of the invention. Figure 31B Viewed from the inside of the operating lever 28 Figure 31A The main part of the first stage (locked state) is shown in the side view. Figure 32A It shows from Figure 31A The shown is a side view of the main part of the second stage (intermediate state) of the operation of pushing the control lever. Figure 32B This is observed from the inside of the control lever. Figure 32A The main part of the second stage (intermediate state) shown is a side view. Figure 33A It shows from Figure 32A The shown is a side view of the main part of the third stage (unlocked state) of the operation of pushing the control lever. Figure 33B This is observed from the inside of the control lever. Figure 33A The main part of the side view shown in the third stage (unlocked state).

[0189] like Figure 31A As shown, in the first stage (locked state), the engaging pin 95 formed on the second plate portion 93 of the swing plate 90 does not abut against the push cam 113 formed on the lever plate 110 of the operating lever 28. Furthermore, as... Figure 31B As shown, the protrusion 96 of the swing plate 90 does not abut against one end 183 of the pressure plate support spring 180. Therefore, in this first stage (locked state), the bearing pressing part 181 of the pressure plate support spring 180 applies force to the pressure plate bearing 51 in the receiving groove 62 toward the bottom 62b of the groove to assist in the holding of the pressure plate roller 45.

[0190] like Figure 32AAs shown, in the second stage (intermediate state), by pressing down the operating lever 28, the engaging pin 95 of the swing plate 90 abuts against the upward cam 113 of the operating lever 28. Furthermore, by further pressing down the operating lever 28, the swing plate 90 moves along the axis of the secondary gear support shaft 81 inserted into the insertion hole 91. Figure 32B The direction of the arrow X in the image swings. For example... Figure 32B As shown, with the swing plate 90 swinging, the protrusion 96 abuts against one end 183 of the pressure plate support spring 180, and the end 183 of the pressure plate support spring 180 is pressed down in a direction away from the pressure plate bearing 51. As a result, the bearing pressing part 181 of the pressure plate support spring 180 retracts in a direction that separates it from the pressure plate bearing 51 in the receiving groove 62, and the disengagement path of the pressure plate bearing 51 is opened.

[0191] like Figure 33A As shown, in the third stage (unlocked state), with Figure 32A and Figure 32B Compared to the state shown, the operating lever 28 is pressed down further, causing the locking arm 140A to swing in the direction of retraction from the receiving groove 62, and the push arm 147 to force the pressure plate bearing 51 upward toward the opening 62a. At this time, since the pressure plate support spring 180 that assists in holding the pressure plate roller 45 in the locked state has already retracted from the receiving groove 62 in the second stage (intermediate state) described above, the pressure plate bearing 51 in the receiving groove 62 can smoothly disengage through the opening 62a.

[0192] As described above, according to this modified example, by providing a pressure plate support spring 180 that assists in holding the pressure plate roller 45, even when there is a gap between the anti-disengagement surface 148A of the locking arm 140A and the pressure plate bearing 51 in the locked state, the loosening caused by this gap can be absorbed and the pressure plate bearing 51 can be held in place. Furthermore, when the lock is released, before the upper push arm 147 pushes the pressure plate bearing 51 upwards, the pressure plate support spring 180 releases the holding of the pressure plate bearing 51 and swings in the direction of retraction from the receiving groove 62, thereby achieving smooth disengagement of the pressure plate roller 45. As a result, the downward pressure of the operating lever 28 required to open the pressure plate roller 45 can be reduced, and operability can be improved.

[0193] The embodiments of the present invention have been described above; however, these embodiments are presented as examples and are not intended to limit the scope of the invention. Embodiments may be implemented in various other ways, and various omissions, substitutions, and changes may be made without departing from the essential points of the invention. Embodiments or variations thereof include, for example, ways readily conceived by those skilled in the art, substantially the same ways, ways with equivalent scope, etc.

[0194] For example, in the above embodiment, an example was described where a fixed blade 46 is provided on the printer cover 3 (specifically, the pressure plate unit 6) and a movable blade 26 is provided on the housing 2 (specifically, the head unit 5), but this is not a limitation. For example, the fixed blade 46 may be provided on the housing 2 side, and the movable blade 26 may be provided on the printer cover 3 side. However, it is not necessary to provide a drive mechanism 27 for driving the movable blade 26 on the printer cover 3 by providing a fixed blade 46 on the printer cover 3 as in the above embodiment. Therefore, the printer cover 3 can be made lighter, and the opening / closing operability of the printer cover 3 can be well ensured.

[0195] Furthermore, in the above embodiment, an example of eliminating paper jams was described by holding the fixed blade 46 in a fixed state and returning the movable blade 26 to the standby position P2 via the operating lever 28, but this is not a limitation. For example, when the movable blade 26 returns to the standby position P2 via the operating lever 28, the fixed blade 46 may also be configured to separate from the movable blade 26. In this case, for example, the operation of separating the fixed blade 46 from the movable blade 26 may also be configured to be operable by the operating lever 28.

[0196] Furthermore, in the above embodiments, an example of the rotational movement of the operating lever 28 and the operating lever 19 provided in the housing 2 has been described, but the invention is not limited to this. For example, the operating lever 28 may be configured such that the front end of the operating lever 28 is exposed to the outside of the housing 2, allowing the operating lever 28 to be operated directly from the outside of the housing 2.

[0197] Furthermore, in the above embodiments, an example has been described where the speed-increasing mechanism 136 is composed of a sun gear 133, a planetary gear 134, and an internal gear 135. However, the speed-increasing mechanism 136 can be configured in other ways. Also, in the above embodiments, the example with a return mechanism 29 has been described, but the return mechanism 29 is not mandatory and may be omitted. Furthermore, even when the return mechanism 29 is included, other configurations can be used.

[0198] Furthermore, in the above embodiment, it is configured to use a pair of locking arms 140, 150 to press both sides of a pair of pressure plate bearings 51, but it is not limited to this case. It can also be configured to use one locking arm to press at least one pressure plate bearing 51.

Claims

1. A type printing unit, characterized in that, have: The head unit has a thermal head for printing onto recording paper; The pressure plate unit is detachably assembled relative to the head unit and has a pressure plate roller for feeding the recording paper and a pair of pressure plate bearings, the pressure plate bearings respectively rotatably supporting the two ends of the pressure plate roller; The operating lever is movable about a rotation axis between a locked position where the pressure plate unit locks the head unit and an unlocked position where the pressure plate unit releases the head unit from the head unit; The pressure plate locking mechanism has a locking arm that can swing about a swing axis parallel to the pressure plate roller, and switches between a locked state that locks the pressure plate roller and an unlocked state that releases the lock. as well as A force-applying component applies force to the locking arm about the swing axis in order to maintain the locked state. The head unit has a pair of receiving grooves that allow the pair of pressure plate bearings to be inserted into the interior through an opening, and when the operating lever is in the locked position, the pair of receiving grooves accommodate the pressure plate bearings with the pressure plate bearings in contact with the bottom of the grooves. When the operating lever is in the locked position, the locking arm presses at least one of the pair of pressure plate bearings housed in the receiving groove from the open side, and as the operating lever moves from the locked position to the unlocked position, the locking arm swings about the swing axis, allowing the pressure plate bearing to disengage from the receiving groove through the open. An upward push arm is formed in the locking arm. As the operating lever moves from the locked position to the unlocked position, the upward push arm pushes the pressure plate bearing from the bottom of the groove towards the open side. The force-applying component applies force to the locking arm toward the pressure plate unit. As the operating lever moves from the locked position toward the unlocked position, the locking arm swings about the swing axis from the pressure plate unit side toward the head unit side, allowing the pressure plate bearing to disengage from the receiving groove through the opening.

2. The printing unit according to claim 1, wherein, When the operating lever is in the locked position, the upper push arm is not in contact with the pressure plate bearing.

3. The printing unit according to claim 1, wherein, An inclined guide protrusion is formed on the inner side of the receiving groove. This guide protrusion is configured such that the opening width narrows from the open side toward the bottom of the groove, and guides the pressure plate bearing toward the bottom of the groove. The upper push arm pushes the pressure plate bearing upward, causing the center of the pressure plate roller to move to the open side compared to the apex of the guide protrusion.

4. The printing unit according to claim 1, wherein, The locking arms are positioned on both sides clamping the pressure plate roller, and are arranged as a pair corresponding to a pair of pressure plate bearings. The pressure plate locking mechanism has a connecting shaft that extends along the swing axis and connects the pair of locking arms to each other.

5. The printing unit according to claim 1, wherein it comprises: A fixed blade is disposed in one of the head unit and the pressure plate unit; A movable blade, which is disposed in another of the head unit and the pressure plate unit and is movable relative to the fixed blade; and A drive mechanism having a drive rack connected to the movable blade, and moving the movable blade between a standby position separated from the fixed blade and a cutting position attached to the fixed blade.

6. The printing unit according to claim 5, wherein it comprises: The return mechanism, with the movable blade stopped in the cutting position and before the pressure plate locking mechanism switches the pressure plate roller to the unlocked position, moves the movable blade from the cutting position to the standby position using the operating force that follows the operation of the operating lever from the locked position to the unlocked position.

7. The printing unit according to claim 6, wherein, The return mechanism has the following features: The return rack is formed on the drive rack; A return auxiliary gear that meshes with the rack teeth of the return rack; The return gear and the sun gear are rotatably supported about the rotation axis when they are configured coaxially with the rotation axis of the operating lever. A planetary gear that meshes with the sun gear and revolves as the operating lever moves; as well as The internal gear meshing with the planetary gear, The return gear can mesh with the return auxiliary gear.

8. The printing unit according to claim 7, wherein, The rack teeth are formed on the opposite side of the tip of the movable blade, such that when the movable blade is in the cutting position, the rack teeth engage with the return gear, and when the movable blade is in the standby position, the rack teeth disengage from the return gear.

9. The printing unit according to claim 1, wherein, The locking arm has a linear anti-disengagement surface, which prevents the pressure plate bearing from disengaging from the receiving groove through the opening in the locked state. A straight line passing through the center of rotation of the locking arm and the center of the pressure plate bearing intersects perpendicularly with the anti-disengagement surface.

10. The printing unit according to claim 1, wherein it comprises: A pressure plate support spring assists in holding the pressure plate bearing within the receiving groove. As the operating lever moves from the locked position toward the unlocked position, the pressure plate support spring moves in the direction of releasing the holding of the pressure plate bearing before the upper push arm pushes the pressure plate bearing, thereby allowing the pressure plate bearing to disengage from the receiving groove through the opening.

11. A thermal printer, characterized in that, have: The printing unit as described in claim 1; The printer body has a recording paper storage section for accommodating the recording paper, and is equipped with one of the head unit and the pressure plate unit; as well as A printer cover, which is rotatably connected relative to the printer body, and is fitted with another of the head unit and the pressure plate unit.

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