printer

Abstract

This printer is designed so that the air blown from the cooling fan is properly expelled after the heatsink has cooled. [Solution] A thermal head 1 with a heat-generating section 11 mounted along the width direction is provided inside a housing 6. The thermal head 1 has a heat sink 12 at a position that dissipates heat from the heat-generating section 11, and the heat sink 12 is cooled by air blown from a cooling fan 81. The heat sink 12 has an air guide section 15 that opens away from the heat-generating section 11, and the cold air that flows in through the air guide section 15 cools the heat sink 12 and is then discharged from the air guide section 15 on the opposite side from the heat-generating section 11.

Description

[[Technical Field]]

[0001] The present invention relates to a printer that improves the flow of air for cooling a thermal head in sublimation printers and the like, and enhances the cooling effect inside a housing. [[Background Art]]

[0002] Conventionally, in thermal printers, it is necessary to discharge heat generated by the head out of the housing in order to cool said heat. For example, in FIG. 4 of Patent Document 1, the air from the fan is arranged at a position that cools the head. In view of the fact that this requires a separate fan for cooling the power supply, as shown in FIG. 5, a configuration has been proposed in which a fan is arranged at a position where the power supply and the head can be cooled in series, thereby enabling cooling of the power supply and the head with a single fan. [[Prior Art Documents]] [[Patent Documents]]

[0003] [[Patent Document 1]] Japanese Patent Application Laid-Open No. 2008-30231 [[Summary of the Invention]] [[Problem to be Solved by the Invention]]

[0004] In the above-mentioned Patent Document 1, in both the configurations of FIG. 4 and FIG. 5, it is premised on a housing structure in which, after the air blown from the fan cools the head, the air directly traverses the inside of the housing and is exhausted from an opposing position.

[0005] However, when the space inside the housing is narrow, in order to secure an air flow, it is necessary to disperse the air inlet and outlet so that air passes (traverses the inside of the housing), and also to secure a space leading to these openings.

[0006] Furthermore, if only a small space can be secured inside the enclosure, the airflow velocity from the fan may decrease or stagnate, causing the temperature of surrounding components to rise. This rise in internal temperature prevents the print head temperature from decreasing, resulting in problems that prevent continuous printing. This is especially true in cases where the internal structure of the enclosure leaves very little room for air to pass through.

[0007] This invention has been made in view of these problems, and aims to realize a printer in which air blown from a cooling fan is properly discharged after the heat sink has cooled. [Means for solving the problem]

[0008] To achieve this objective, the present invention employs the following means.

[0009] In other words, the printer according to the present invention is A thermal head with a heat-generating element mounted along its width is provided inside the housing, the thermal head has a heat sink at a position to dissipate the heat from the heat-generating element, and the heat sink is cooled by airflow from a cooling fan, The heat sink has an air guide portion that opens away from the heat-generating portion, The device is characterized in that the cold air that flows in through the air guide section cools the heat sink and is then discharged from the air guide section towards the repulsive heat section.

[0010] This design prevents the airflow after cooling the heatsink from circling around or accumulating near the heat-generating components, allowing it to be expelled through the air guide in a direction that does not affect the heat-generating parts. Therefore, even if the structure does not allow air from the cooling fan to flow smoothly through the inside of the casing, it is possible to appropriately improve the cooling efficiency inside the printer.

[0011] Preferably, the heat sink has a plurality of fins extending along the width direction, and the cold air enters the air guide section, flows along the fins, and is then discharged outside the air guide section along the side walls located on both sides of the air guide section in the width direction.

[0012] In this way, the introduced cool air flows along fins installed along the heat-generating section from the introduction point to the discharge point, ensuring a smooth airflow while effectively dissipating heat from the heat-generating section.

[0013] The interior of the housing is divided by a partition wall between the printing space where the thermal head is located and the cooling space where the cooling fan is located. Preferably, the partition wall has an opening that allows the cool air from the cooling fan to enter and exit, corresponding to the opening in the air guide portion of the heat sink.

[0014] In this way, the air coming out of the air guide is properly directed towards the cooling space through the opening, effectively preventing it from flowing out into the printing space.

[0015] The thermal head is rotatably mounted on a mounting wall that protrudes from the partition wall toward the printing space, and it is preferable that the gap between the left and right side walls of the air guide section and the partition wall is sealed by the mounting wall.

[0016] In this way, even when the thermal head is rotatable relative to the partition wall, the mounting wall can effectively prevent the airflow from the air guide from flowing into the printing space.

[0017] Preferably, the cooling space contains a power supply unit and a second cooling fan that blows air in a direction intersecting with the cooling fan, and the exhaust from the air guide is carried out to the outside of the casing by the air blown by the second cooling fan. This makes it possible to further improve cooling efficiency, and by eliminating the need to secure a certain amount of heat dissipation area, it is possible to increase the flexibility of the installation location and effectively dissipate heat even in a structure in which the top cover of the printer itself does not open. [Effects of the Invention]

[0018] According to the present invention described above, it is possible to provide a printer in which air blown from a cooling fan is appropriately discharged after cooling the heat sink. [Brief Description of the Drawings]

[0019] [Figure 1] Partial side view showing a schematic configuration of a printer according to an embodiment of the present invention. [Figure 2] Partial perspective view showing a state before assembling a thermal head and a holder of the same printer. [Figure 3] Side view corresponding to FIG. 3. [Figure 4] Perspective view showing a structure behind a thermal head. [Figure 5] Exploded perspective view explaining a mounting structure of a thermal head to an inner wall of a housing. [Figure 6] Longitudinal sectional view corresponding to FIG. 5. [Figure 7] Transverse sectional view corresponding to FIG. 5. [Mode for Carrying Out the Invention]

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0021] The printer of this embodiment is a sublimation type printer called a thermal printer. As shown in FIGS. 1 and 2, a heat generating portion 11 is arranged extending at the tip end of a thermal head 1, and a position where the heat generating portion 11 of the thermal head 1 is pressed against a platen roller 2 is defined as a printing portion P. The printing portion P sandwiches a sheet 3 and a ribbon 4 and heats the heat generating portion 11, so that the dye of the ribbon 4 is transferred onto the sheet 3 to perform printing.

[0022] In the following description, for convenience, the direction in which the thermal head 1 is pressed against the platen roller 2 (left direction in FIG. 1) is referred to as front, and the opposite direction (right direction in FIG. 1) is referred to as rear. In addition, the direction perpendicular to the paper surface is referred to as the width direction, and the vertical direction on the paper surface is referred to as the up-down direction.

[0023] The thermal head 1 is mounted on the holder 5 in a manner that allows it to move within a predetermined range. The holder 5 is supported by a thermal head support wall 61 provided inside the housing 6.

[0024] A pair of ribbon reels 41 and 42 are provided inside the housing 6, and the ribbon 4 unwound from one of the ribbon reels 41 and 42 is wound onto the other after passing through the printing unit P. A paper reel 31 is also provided so that the paper 3 can be fed to the printing unit P along with the ribbon 4. After the paper 3 is set and the paper roll 30 attached to the paper reel 31 passes through the feed roller unit 7, the feed roller unit 7 feeds and retracts the paper 3, and printing is performed in the printing unit P when the paper 3 is retracted. The printed paper 3 is configured to be discharged through a predetermined path.

[0025] The thermal head 1 has a block that functions as a heat sink 12 at the rear of the thermal head body 10, and a recess 13a is provided at the rear edge of the side wall 13 located behind the block, and a columnar first shaft 52 is spanned between opposing mounting walls 51, 51 in the corresponding holder 5.

[0026] The first shaft 52 is inserted into a long groove 53 provided in the mounting wall 51 so as to be movable back and forth, with one end of an elastic spring (in this case, a tension coil spring) 50 attached to it, and the other end of the spring 50 attached to the front end of the mounting wall 51 as shown in Figure 7, thereby biasing the first shaft 52 toward the front end of the long groove 53. When the first shaft 52 is pushed backward, the spring 50 accumulates elastic force (repulsive force) along the long groove 53, causing the first shaft 52 to move toward the rear end.

[0027] During printing, the heating element 11 is in relative contact with / not in contact with the platen roller 2 by a drive unit (not shown) that drives the platen roller 2. Of course, the thermal head 1 may also be configured to perform a similar operation by moving it up and down using a cam mechanism.

[0028] The first shaft 52 and the recess 13a constitute the first engaging portion E1 shown in Figure 1. This first engaging portion E1 allows the thermal head 1 to be supported so that its angle can be changed around the axis of the first shaft 52. Furthermore, the reaction force of the spring 50 caused by pushing in the first shaft 52 allows the heating portion 11 of the thermal head 1 to be positioned so that it elastically contacts the platen roller 2, as shown in Figure 1.

[0029] In order to maintain the thermal head 1 in the holder 5 even when the heating element 11 is not in contact with the platen roller 2, a second engaging portion E2 is provided between the thermal head 1 and the holder 5, as shown in Figure 1. The second engaging portion E2 consists of a second shaft 14 made of a stud that protrudes outward from the side wall 13 of the thermal head 1 parallel to the first shaft 52, and a J-shaped guide 54 provided on the holder 5 that fits and guides the second shaft 14. The guide 54 is formed by providing a groove in the mounting wall 51 of the holder 5.

[0030] The assembly procedure involves bringing the thermal head 1 close to the holder 5 from an oblique angle, as shown by arrow T0 in Figure 3, and engaging it with the holder 5 (i.e., the housing 6) at the first engaging portion E1. While doing so, the first shaft 52 is pushed in, and the thermal head 1 is rotated as shown by arrow T1 with the first shaft 52 as the pivot point. Then, the thermal head 1 is moved in the direction of the reaction force as shown by arrow T2. During this time, the second shaft 14 engages with the inner end 54d of the first guide 54 via points 54a, 54b, and 54c, and the thermal head 1 moves to a position where it can elastically contact the platen roller 2.

[0031] The block-shaped heatsink 12 of the thermal head 1 is made of a material with excellent heat dissipation properties. For example, in Figure 1, a structure is typically employed in which air is blown onto this heatsink 12 from right to left in the figure by a cooling fan (not shown) to provide air cooling.

[0032] However, simply blowing cold air from the back to the front is unlikely to work. As shown by the dashed arrow Z in Figure 5, the cold air will hit the heat sink 12 and then disperse in all directions (up, down, left, and right), flowing (circling around) into the space where the paper roll 30, feed roller section 7, platen roller 2, and heat-generating section 11 are located, as shown in Figure 1. In that space, the air will swirl around, reducing the flow velocity and potentially causing stagnation.

[0033] As a result, the temperature of surrounding components rises, and due to the rise in internal temperature, the head temperature of thermal head 1 does not decrease, leading to the same problem as described in the prior art document section: continuous printing is not possible.

[0034] Therefore, in this embodiment, as shown in Figures 1 and 5, the thermal head support wall 61 is made as close as possible to the outer wall of the housing 6 so that it functions as a partition wall, thereby dividing the space into a printing space S1 on the front side where the thermal head 1 is located and a cooling space S2 on the rear side where the cooling fan 81 is located. Except for the rectangular opening 62 provided in the thermal head support wall 61, the space is configured to minimize air exchange between the two spaces S1 and S2.

[0035] As shown in Figures 1 to 5, an air guide section 15 is provided behind the heat sink 12 attached to the thermal head 1, and the width and height dimensions of the opening 62 of the thermal head support wall 61 and the air guide section 15 are set to be approximately corresponding. As a result, as shown in Figures 6 and 7, the cool air blown from the cooling fan 81 located in the cooling space S2 toward the air guide section 15 as indicated by arrow A1 can be discharged back towards the cooling space S2 side as indicated by arrow A2 in Figures 6 and 7, without diffusing up, down, left, or right after cooling the heat sink as indicated by arrow Z in Figure 5.

[0036] As shown in Figures 2 to 6, the air guide section 15 is constructed in a rectangular tubular shape (approximately trumpet-shaped) that expands to the rear, with an upper wall 15b and a lower wall 15c connected to the left and right side walls 15a. The heat sink 12 has multiple fins 12b protruding from the back surface 12a of the block, parallel to the direction of extension of the heat-generating section 11 (see Figure 6 in particular), and notches 12c are provided between the left and right fins 12b, 12b.

[0037] Although the provision of the air guide section 15 prevents the air after cooling the heat sink 12 from diffusing up, down, left, and right as indicated by arrow Z in Figure 5, the air guide section 15 is not directly attached to the thermal head support wall 61, and a certain gap Δ exists between it and the thermal head support wall 61, as shown in Figures 3, 6, and 7.

[0038] Therefore, in this embodiment, in order to prevent air from leaking out into the printing space S1 from the gap Δ between the air guide 15 and the thermal head support wall 61, the surface of the mounting plate 51 of the holder 5, which originally rotatably supports the thermal head 1, is expanded, and the gap Δ is closed from the outside in the width direction (the direction perpendicular to the paper surface in Figure 6, and the left-right direction of the paper surface in Figure 7) by this mounting wall 51, thereby blocking as much as possible the escape route of air from the gap Δ in the width direction, as shown by the dashed arrow r1 in Figure 7.

[0039] Furthermore, baffles 61b and 61c extend from the upper and lower edges of the opening 62 of the thermal head support wall 61 toward the printing space S1, and these baffles 61b and 61c are inserted into the interior of the air guide section 15 to the extent that they do not interfere with the upper wall 15b and lower wall 15c of the air guide section 15 when the thermal head 1 rotates, thereby closing the gap Δ from the vertical direction (the vertical direction of the paper in Figure 6, and the vertical direction of the paper in Figure 7), and blocking the escape route of air from the gap Δ in the width direction, as shown by the dashed arrow r2 in Figure 6.

[0040] Furthermore, the cooling fan 81 shown in Figure 5 has its air outlet position adjusted so that it can blow cool air from the cooling space S2 towards the heat sink 12, towards the notch 12c located in the center of the upper, lower, left, and right fins 12b.

[0041] As a result, the cold air blown toward the back surface 12a of the heatsink 12 as shown by arrow A1 in Figure 7, before hitting or after hitting the back surface 12a of the heatsink 12, bounces off and then branches to the left and right, flows into the fins 12b, flows along the fins 12b in the width direction, and then, as shown by arrow A2, collides with the left and right side walls 15a, changes direction toward the rear, and forms a flow that is exhausted from the opening 62 to the cooling space S2. In Figure 6, arrows A1 and A2 are shown at different heights, but this only indicates the inflow and outflow of air. In reality, the air is blown in while rotating and exhausted while spreading, so an airflow is formed over almost the entire area in the height direction as well.

[0042] In this embodiment, as shown in Figures 5 and 7, a power supply unit 9 that supplies the power necessary for printing operations is located in the cooling space S2, and a second cooling fan 82 that blows air in a direction intersecting with the cooling fan 81 is located on one of the left and right side walls 63 of the housing 6. As shown by arrow B in Figure 7, this second cooling fan 82 is configured to cool the power supply unit 9 and then exhaust air from an exhaust port 82a provided on the opposite side wall 63.

[0043] The exhaust from the aforementioned air guide section 5 is carried out to the outside of the casing 6 along arrow B by the airflow from the second cooling fan 82. This structure, which uses the second cooling fan 82 in conjunction with the casing, eliminates exhaust to the rear of the casing, thus eliminating the need to secure a heat dissipation area at the rear when installing the printer. This allows the printer to be installed in places with limited depth or where the ceiling is close. Furthermore, heat dissipation can be effectively carried out even if the top cover of the printer itself cannot be opened.

[0044] As described above, the printer of this embodiment is In a configuration in which a thermal head 1 with a heat-generating element 11 mounted along the width direction is provided within a housing 6, the thermal head 1 has a heat sink 12 at a position to dissipate heat from the heat-generating element 11, and the heat sink 12 is cooled by airflow from a cooling fan 81, The heat sink 12 has an air guide portion 15 that opens away from the heat generating portion 11. The system is configured such that the cold air flowing in through the air guide 15 cools the heat sink 12, and then is discharged from the air guide 15 on the side opposite to the heat generating section 11.

[0045] This configuration prevents the airflow after cooling the heatsink 12 from circulating around or accumulating on the heat-generating part 11 side, and allows it to be discharged through the air guide 15 in a direction that does not affect the heat-generating part 11. Therefore, even if the structure does not allow the airflow from the cooling fan 81 to flow smoothly through the inside of the casing 6, it is possible to appropriately improve the cooling efficiency inside the printer.

[0046] The heat sink 12 also has a plurality of fins 12b that extend along the width direction, and the cold air enters the air guide section 15, flows along the fins 12b, and is then discharged outside the air guide section 15 along the side walls 15a located on both sides of the air guide section 15 in the width direction.

[0047] With this configuration, the introduced cold air flows along the fins 12b provided along the heat-generating section 11 from the introduction point to the discharge point, ensuring a smooth airflow while effectively dissipating heat from the heat-generating section 11.

[0048] Furthermore, the inside of the enclosure 6 is divided between the printing space S1 where the thermal head 1 is located and the cooling space S2 where the cooling fan 81 is located by a thermal head support wall 61, which acts as a partition. The thermal head support wall 61 has an opening 62 that allows cold air from the cooling fan 81 to enter and exit, corresponding to the opening of the air guide section 15 of the heat sink 12.

[0049] With this configuration, the air coming out of the air guide section 15 is properly guided to the cooling space S2 side through the opening, so that it can be properly prevented from flowing out into the printing space S1.

[0050] Furthermore, the thermal head 1 is rotatably mounted on a mounting wall 51 that protrudes from the thermal head support wall 61, which is a partition wall, toward the printing space S1, and the gap Δ between the left and right side walls 15a of the air guide section 15 and the thermal head support wall 61, which is a partition wall, is closed by the mounting wall 51.

[0051] With this configuration, even when the thermal head 1 is rotatable relative to the thermal head support wall 61, which acts as a partition, the mounting wall 51 can effectively prevent the air coming out of the air guide section 15 from flowing into the printing space S1.

[0052] Furthermore, the air guide section 15 has an opening that expands vertically, and upper and lower baffles 61b and 61c extend inward from the thermal head support wall 61 so as not to interfere with the upper wall 15b and lower wall 15c of the air guide section 15. The gap Δ between the upper wall 15b and lower wall 15c of the air guide section 15 and the thermal head support wall 61, which acts as a partition, is closed by the upper and lower baffles 61b and 61c.

[0053] Even with this configuration, when the heat sink 12 is rotatable relative to the thermal head support wall 61 which acts as a partition, the baffles 61b and 61c can effectively prevent the air coming out of the air guide section 15 from flowing into the printing space S1.

[0054] Furthermore, the cooling space S2 houses the power supply unit 9, and a second cooling fan 82 is positioned to blow air in a direction intersecting with the cooling fan 81. The exhaust from the air guide unit 15 is carried out to the outside of the housing 6 by the airflow from the second cooling fan 82.

[0055] This configuration makes it possible to further improve cooling efficiency. Furthermore, the structure with the second cooling fan 82 attached to the first cooling fan 81 eliminates exhaust to the rear of the enclosure, thus eliminating the need to secure a heat dissipation area at the rear when installing the printer. This allows the printer to be installed in places with limited depth or where the ceiling is close. In addition, it becomes possible to effectively dissipate heat even if the top cover of the printer itself cannot be opened.

[0056] Although one embodiment of the present invention has been described above, the specific configuration of each part is not limited to the embodiment described above.

[0057] For example, although a second cooling fan was used in the above embodiment, the air guide can also be configured to be discharged outside the housing in the same flow.

[0058] Furthermore, the printer does not have to be a dye-sublimation type.

[0059] Furthermore, if the thermal head is designed not to rotate, the air guide can be directly attached to the bulkhead.

[0060] Furthermore, various modifications are possible without departing from the spirit of the present invention, such as providing multiple cooling fans 81 and 82, or extending plates from the thermal head side to replace the baffle plates 61b and 61c and inserting them into the opening 62. [Explanation of Symbols]

[0061] 1…Thermal head 9...Power supply section 11…heating part 12… Heatsink 12b... Finn 15...Air guide 15a...Side wall 15b…Top wall 15c…Lower wall 51… Mounting wall 61… Partition wall (thermal head support wall) 61b, 61c... Obstacle boards 62…Opening 81…Cooling fan 82...Second cooling fan S1…Printing space S2…Cooling space Δ...gap

Claims

1. A thermal head with a heat-generating element mounted along its width is provided inside the housing, the thermal head has a heat sink at a position to dissipate heat from the heat-generating element, and the heat sink is cooled by airflow from a cooling fan, The heat sink has an air guide portion that opens away from the heat-generating portion, A printer characterized in that the cold air that flows in through the air guide section cools the heat sink and is then discharged from the air guide section towards the repulsive heat section.

2. The printer according to claim 1, wherein the heat sink has a plurality of fins extending along the width direction, and cold air enters the air guide section, flows along the fins, and is then discharged outside the air guide section along the side walls located on both sides of the air guide section in the width direction.

3. The interior of the housing is divided by a partition wall between the printing space where the thermal head is located and the cooling space where the cooling fan is located. The printer according to claim 2, wherein the partition wall has an opening formed therein for introducing and discharging cold air from the cooling fan, corresponding to the opening of the air guide portion of the heat sink.

4. The printer according to claim 3, wherein the thermal head is rotatably mounted on a mounting wall that protrudes from the partition wall toward the printing space, and the gap between the left and right side walls of the air guide and the partition wall is closed by the mounting wall.

5. The printer according to any one of claims 1 to 4, wherein a power supply unit is arranged in the cooling space, and a second cooling fan is arranged to blow air in a direction intersecting the cooling fan, and exhaust from the air guide is carried out to the outside of the housing by the air blown by the second cooling fan.

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