Printing device

Abstract

According to the present invention, the device is made compact, ink can be consumed and replenished efficiently, and settling of ink components can be prevented.　This printing device is provided with a placement surface on which a medium is placed, and a carriage equipped with a head that ejects ink toward the placement surface and an ink supply unit that is disposed above the head and that supplies ink to the head, the carriage being capable of moving in a main scanning direction along the placement surface, wherein the ink supply unit includes: one or more ink tanks that include a storage portion for storing ink, and an injection portion for injecting ink stored in an external container into the storage portion; and an ink circulation path that is provided for each ink tank and that includes an ink supply path for supplying the ink stored in the storage portion to the head, and an ink return flow passage for returning the ink supplied to the head to the storage portion of the ink tank.

Description

printing device

[0001] The present invention relates to a printing device.

[0002] 2. Description of the Related Art Known printing devices that print on media include inkjet printing devices that eject ink from a head onto the media (see, for example, Japanese Patent Application Laid-Open No. 2003-124998).

[0003] Japanese Patent Application Laid-Open No. 2017-109360

[0004] The printing device is required to be compact and have a configuration that allows for efficient consumption and replenishment of ink, as well as preventing deterioration of image quality by preventing the settling of ink components.

[0005] The present invention has been made in consideration of the above, and aims to provide a printing device that is compact, can efficiently consume and replenish ink, and can prevent ink components from settling.

[0006] The printing device of the present invention is equipped with a carriage that is movable in a main scanning direction along the mounting surface and that is equipped with a mounting surface on which media is placed, a head that ejects ink toward the mounting surface, and an ink supply unit that is arranged above the head and supplies the ink to the head, and the ink supply unit has one or more ink tanks that have a storage unit that stores the ink and an injection unit for injecting the ink stored in an external container into the storage unit, and an ink circulation path that is provided for each ink tank and includes an ink supply path that supplies the ink stored in the storage unit to the head and an ink return path that returns the ink supplied to the head to the storage unit of the ink tank.

[0007] According to the present invention, the device can be made compact, ink can be consumed and replenished efficiently, and sedimentation of ink components can be prevented.

[0008] FIG. 1 is a diagram (perspective view) showing an example of a printing device according to the present embodiment. FIG. 2 is a diagram (front view) showing an example of a printing device according to the present embodiment. FIG. 3 is a perspective view showing a partial configuration of the image forming unit (when a carriage cover is provided). FIG. 4 is a perspective view showing a partial configuration of the image forming unit (when the carriage cover is omitted). FIG. 5 is a view of the interior of the carriage as seen from the front side. FIG. 6 is a view of the carriage as seen from below. FIG. 7 is a view showing an example of the interior of the carriage as seen from the side (left). FIG. 8 is a view showing the configuration along the cross section taken along arrows A-A in FIG. 5. FIG. 9 is a view showing the configuration along the cross section taken along arrows B-B in FIG. 7. FIG. 10 is a view showing the configuration along the cross section taken along arrows C-C in FIG. 8. FIG. 11 is a cross-sectional view showing an example of an external container when not attached to the injection unit. FIG. 12 is a cross-sectional view showing an example of an external container when attached to the injection unit.

[0009] Hereinafter, an embodiment of a printing device according to the present invention will be described with reference to the drawings. However, the present invention is not limited to this embodiment. Furthermore, the components in the following embodiments include those that are easily replaceable by those skilled in the art, or those that are substantially identical.

[0010] In this embodiment, directions in the figures are described using an XYZ coordinate system. In this XYZ coordinate system, a plane parallel to the floor on which the printing device 100 is placed is referred to as the XY plane. In this XY plane, the main scanning direction, which is the direction of head movement, is referred to as the Y direction, and the direction perpendicular to the Y direction on the XY plane is referred to as the X direction. The direction perpendicular to the XY plane (height direction) is referred to as the Z direction. The X, Y, and Z directions are described assuming that the direction of the arrow in the figure is the + direction and the direction opposite to the arrow is the - direction. In this embodiment, the +X direction may be referred to as the front direction (front side), the -X direction as the rear direction (rear side), the +Y direction as the left (left side), the -Y direction as the right (right side), the +Z direction as the up (upper side), and the -Z direction as the down (lower side).

[0011] 1 and 2 are diagrams illustrating an example of a printing device 100 according to this embodiment. FIG. 1 is a perspective view, and FIG. 2 is a front view. The printing device 100 includes a housing 10, a table unit 20, an image forming unit 30, a maintenance unit 50, and a control unit CONT. The printing device 100 illustrated in this embodiment is an inkjet printing device that ejects ink onto a medium to form characters, designs, and the like. The control unit CONT comprehensively controls the operation of the table unit 20, the image forming unit 30, and the maintenance unit 50.

[0012] The housing 10 forms the exterior of the printing device 100. The housing 10 may be provided with various operation units for operating the printing device 100.

[0013] The table unit 20 has a base 21, a table 22, and a table driving unit 23. The base 21 supports the table 22 and the table driving unit 23. The table 22 has a mounting surface 22a on which the media M is placed. The media M can be various items such as paper, cloth, film, or plate material. The table driving unit 23 moves the table 22 in the X and Z directions. The table driving unit 23 has a driving source such as a motor, and a transmission mechanism that transmits the driving force of the driving source to the table 22. Examples of the transmission mechanism include a belt mechanism and a cam mechanism.

[0014] The image forming unit 30 has a carriage 31 and a guide bar 32. The carriage 31 moves in the Y direction along the guide bar 32 by a carriage drive unit (not shown). FIGS. 3 and 4 are perspective views showing a portion of the configuration of the image forming unit 30. FIG. 3 shows a configuration including the cover 33 of the carriage 31, while FIG. 4 shows a configuration in which the cover 33 of the carriage 31 is omitted. FIG. 5 is a view of the interior of the carriage 31 as seen from the front side. Note that FIGS. 4 and 5 omit partial illustration of the supply flow path 71 and the return flow path 81. FIG. 6 is a view of the carriage 31 as seen from below. FIG. 7 is a view showing an example of the interior of the carriage 31 as seen from the side (left).

[0015] The carriage 31 is formed in a box shape and is supported by a guide bar 32. The carriage 31 has a cover 33. The cover 33 has a front surface 33a, side surfaces 33b, a bottom surface 33c, and a top surface 33d. A lid portion 33f is provided on the top surface 33d. The lid portion 33f is openable and closable. FIG. 3 shows the lid portion 33f in an open state. By opening the lid portion 33f, the top of the ink tank 36 is exposed. The carriage 31 is movable in the Y direction along the guide bar 32. A head 34 and an ink supply unit 35 are mounted on the carriage 31.

[0016] A plurality of heads 34 are provided on the bottom surface of the carriage 31. Openings 33e are provided in the bottom surface portion 33c of the cover 33 of the carriage 31 at positions corresponding to the respective heads 34 (see Figures 5, 6, etc.). The plurality of heads 34 are arranged in a state where they are exposed through the openings 33e. The plurality of heads 34 are arranged side by side in the Y direction, which is the main scanning direction. In this embodiment, for example, two heads 34 are arranged with a gap in the Y direction. These two heads 34 are arranged at positions offset in the X direction.

[0017] Each head 34 has a plurality of nozzles 34N. The plurality of nozzles 34N are arranged in a line in the X direction to form a nozzle row 34L. Each head 34 ejects ink for image formation from the nozzles 34N toward the mounting surface 25a of the table 22. The carriage 31 moves over the mounting surface 22a in the Y direction, which is the main scanning direction, to scan the mounting surface 22a in the Y direction. Various inks, such as aqueous inks and ultraviolet-curable inks, can be used. For example, colored inks such as white ink, cyan (C), magenta (M), yellow (Y), and black (K) can be used depending on the color of the image to be formed on the medium M. In the case of ultraviolet-curable ink, transparent inks can also be used as appropriate. When ultraviolet-curable ink is used, the carriage 31 is equipped with an ultraviolet irradiation device (not shown) that irradiates the ultraviolet-curable ink with ultraviolet light.

[0018] The ink supply unit 35 supplies ink to the head 34. The ink supply unit 35 has an ink tank 36 and an ink circulation path 40. The ink circulation path 40 includes an ink supply path 37 and an ink return path 38.

[0019] The ink tank 36 is a supply source for various inks. One or more ink tanks 36 are provided depending on the type of ink, and in this embodiment, multiple ink tanks 36 are provided. Multiple ink tanks 36 are arranged side by side in the left-right direction. Figures 8 to 10 are cross-sectional views showing the internal configuration of the ink tank 36. Figure 8 is a view showing the configuration along the cross section taken along arrows A-A in Figure 5. Figure 9 is a view showing the configuration along the cross section taken along arrows B-B in Figure 7. Figure 10 is a view showing the configuration along the cross section taken along arrows C-C in Figure 8.

[0020] 8 to 10, the ink tank 36 has a storage section 61 and an injection section 62. The storage section 61 stores ink. An opening 61a is provided at the top of the storage section 61. The opening 61a is connected to a tank-side portion 81c of a reflux flow path 81, which will be described later. An opening 61b is provided at the bottom of the storage section 61. The opening 61b is connected to a tank-side portion 71a of a supply flow path 71, which will be described later. The injection section 62 is provided to inject ink stored in an external container, such as an ink bottle, into the storage section 61.

[0021] The injection port 62 is provided between the storage portion 61 and the outside. The ink tank 36 is provided with a lid (not shown) that covers the injection port 62. The lid can be opened and closed by rotating it about an axis extending in the left-right direction. Opening the lid exposes the injection port 62. The injection port 62 includes a tubular member 63 and an absorbing member 64. The tubular member 63 protrudes upward from the storage portion 61. The tubular member 63 has a first flow path 63a and a second flow path 63b defined by a partition member 63c. The partition member 63c extends, for example, to the upper end of the tubular member 63. The first flow path 63a and the second flow path 63b are arranged parallel to each other inside the tubular member 63 and connect the storage portion 61 to the outside. When ink is poured from an external container into the storage portion 61, the first flow path 63a allows the poured ink to flow into the storage portion 61. The second flow path 63b exhausts gas from inside the storage portion 61 to the outside. The tubular member 63 has an inclined portion 63d at the lower end portion. The inclined portion 63d is formed so as to be inclined downward toward the front side.

[0022] An absorbing member 64 is provided for each ink tank 36. The absorbing member 64 is sheet-shaped or plate-shaped and is arranged on the top surface of the ink tank 36 so as to surround the injection part 62. The absorbing member 64 absorbs ink that drips when the external container is attached to or detached from the injection part 62. This prevents the ink tank 36 from being soiled with ink. The absorbing member 64 is made of a fibrous material such as felt. The absorbing member 64 is provided so as to be replaceable.

[0023] A float sensor 65 is provided in the container 61. The float sensor 65 measures the amount of ink Q contained in the container 61. The float sensor 65 has a float 65a, a guide member 65b, and a detection portion 65c.

[0024] The float 65a is disposed inside the storage portion 61. In this embodiment, the float 65a is disposed at the rear end of the interior of the storage portion 61. The float 65a is made of a material that floats on the ink surface. As ink is consumed and reduced, the float 65a moves downward together with the ink surface. Guide members 65b are disposed on both sides of the float 65a in the main scanning direction. The guide members 65b restrict movement of the float 65a in the main scanning direction while allowing movement of the float 65a in the up and down directions. The detection unit 65c detects the up and down position of the float 65a. The detection unit 65c is provided outside the storage portion 61. In this embodiment, the detection unit 65c is attached to the wall portion 36a on the rear side of the ink tank 36. In this way, by arranging the float 65a, guide member 65b and detection portion 65c of the float sensor 65 on the rear side of the ink tank 36, the position of the liquid surface in the storage portion 61 becomes more visible when viewing the ink tank 36 from the front side.

[0025] Returning to FIG. 3 and FIG. 7 , the explanation will continue. An ink supply path 37 is provided for each ink tank 36. The ink supply path 37 has a supply flow path 71, a supply valve 72, and a damper 73. The supply flow path 71 connects the storage section 61 of the ink tank 36 to the damper 73. For example, a tube or the like is used for the supply flow path 71. The supply flow path 71 is made of, for example, a flexible member. The supply flow path 71 has a tank side portion 71 a on the upstream side of the supply valve 72, and a damper side portion 71 b on the downstream side of the supply valve 72.

[0026] The damper-side portion 71b extends downward from the front end of the supply valve 72, curves toward the rear from the downward extension, and connects to the damper 73. An ink absorbing member 39 is disposed below the connection between the supply valve 72 and the damper-side portion 71b. The ink absorbing member 39 is disposed while being supported by a rib 33g on the inner surface of the front portion 33a of the cover 33 of the carriage 31 (see FIG. 7). The rib 33g is disposed on an inclined portion 33s below the front portion 33a and protrudes toward the rear. The inclined portion 33s is disposed so as to be inclined downward toward the rear. By providing the ink absorbing member 39, if ink leaks from the supply valve 72 into the damper-side portion 71b, the ink can be appropriately absorbed.

[0027] The supply valves 72 are provided in the supply flow paths 71 and open and close the supply flow paths 71. The supply valves 72 are arranged below each ink tank 36. In this embodiment, the supply valves 72 are arranged side by side in the left-right direction to correspond to the arrangement of the ink tanks 36. The main body of each supply valve 72 is rectangular and extends in one direction when viewed from the top and bottom. The multiple supply valves 72 are arranged inclined in the same direction relative to the front-to-rear direction when viewed from below. This arrangement allows the supply valves 72 to be arranged compactly in the left-to-right direction.

[0028] The damper 73 has an ink chamber 73a (see FIG. 7). The ink chamber 73a stores ink that flows in from the damper side portion 71b of the supply flow path 71. The damper 73 supplies the ink stored in the ink chamber 73a to the head 34.

[0029] The ink reflux channel 38 returns the ink stored in the damper 73 to the containing section 61 of the ink tank 36 in order to suppress sedimentation of ink components. The ink reflux channel 38 is provided for one or more ink supply channels 37. In this embodiment, an example is given in which the ink reflux channel 38 is provided for two ink supply channels 37. The ink reflux channel 38 may be provided for all ink supply channels. The ink reflux channel 38 is arranged on the rear side of the ink supply channel 37. The ink reflux channel 38 has a reflux channel 81, a reflux valve 82, and a reflux pump 83.

[0030] The reflux channel 81 connects the damper 73 and the ink tank 36's storage compartment 61. The reflux channel 81 may be formed, for example, using a tube. The reflux channel 81 may be formed, for example, of a flexible material. The reflux channel 81 includes a damper-side portion 81a upstream of the reflux valve 82, an intermediate portion 81b between the reflux valve 82 and the reflux pump 83, and a tank-side portion 81c downstream of the reflux pump 83. The reflux valve 82 opens and closes the reflux channel 81. The reflux valve 82 is disposed behind the supply valve 72 and below the supply valve 72. The reflux pump 83 is disposed within the reflux channel 81, downstream of the reflux valve 82. The reflux pump 83 moves ink in the reflux channel 81 from the damper 73 toward the storage compartment 61. The reflux pump 83 is disposed behind the ink tank 36.

[0031] The damper-side portion 81a extends upward from the damper 73, curves toward the front, and is connected to the reflux valve 82. The middle portion 81b extends upward from the reflux valve 82, curves backward, and is connected to the reflux pump 83. The tank-side portion 81c extends upward from the reflux pump 83, curves toward the front, and is connected to the storage portion 61 of the ink tank 36. With this configuration, the length of the tank-side portion 81c from the reflux pump 83 to the storage portion 61 of the ink tank 36 can be reduced.

[0032] Next, a description will be given of an example of the operation of the printing apparatus 100 configured as described above. First, when the medium M is placed on the placement surface 22a, the control unit CONT adjusts the initial positions of the head 34 and the table 22.

[0033] Next, the control unit CONT ejects ink from the nozzles 34N onto the medium M while moving the table 22 and the head 34 relative to one another. That is, the control unit CONT ejects ink from the nozzles 34N while moving the head 34 in the main scanning direction and the table 22 in the sub-scanning direction. This operation forms an ejection pattern on the medium M. During the printing operation, the control unit CONT opens the supply valve 72 to supply ink from the storage section 61 of the ink tank 36 to the ink chambers 73a of the damper 73 via the supply flow path 71. The ink supplied to the ink chambers 73a is supplied to the head 34. The ink supplied to the head 34 is ejected onto the medium M.

[0034] In the printing device 100, when the head 34 is on standby, ink components may settle, for example, in the ink chamber 73a of the damper 73, resulting in uneven ink concentration. For this reason, the printing device 100 periodically performs a reflux operation to reflux the ink in the ink chamber 73a back to the ink tank 36 via the ink reflux path 38, thereby suppressing the sedimentation of ink components.

[0035] In the reflux operation, the control unit CONT opens the supply valve 72 and the reflux valve 82, and operates the reflux pump 83. As a result, the ink in the ink chamber 73a of the damper 73 flows into the damper-side portion 81a of the reflux flow path 81, and then flows into the storage portion 61 of the ink tank 36 via the reflux valve 82, the intermediate portion 81b, the reflux pump 83, and the tank-side portion 81c. Also, the ink in the storage portion 61 flows into the ink chamber 73a of the damper 73 via the tank-side portion 71a of the supply flow path 71, the supply valve 72, and the damper-side portion 71b. In this way, ink circulates between the damper 73 and the ink tank 36.

[0036] During printing, the ink contained in the storage section 61 of the ink tank 36 is consumed. As the ink is consumed and reduced, the float 65a inside the storage section 61 moves downward along with the ink level. The detection section 65c detects the vertical position of the float 65a and transmits the detection result to the control section CONT. When the float 65a reaches a predetermined height, the control section CONT can output information urging the user to replenish the ink to a display device (not shown) or the like provided in the printing device 100.

[0037] When refilling ink, an external container such as an ink bottle is attached to the filling portion 62 of the ink tank 36. FIG. 11 is a cross-sectional view showing an example of an external container 90. FIG. 12 is a cross-sectional view showing an example of the external container 90 attached to the filling portion 62. As shown in FIGS. 11 and 12 , the external container 90 has a structure such that, when its ink outlet 91 is attached to the filling portion 62, an opening / closing mechanism 92 provided at the ink outlet 91 opens, allowing ink Q to be discharged from the storage portion 96. The opening / closing mechanism 92 includes, for example, a spherical plug member 92a and an elastic member 92b that biases the plug member 92a toward the opening. When the external container 90 is not attached to the filling portion 62 (see FIG. 11 ), the plug member 92a is biased by the elastic member 92b to close the opening of the ink discharge path 93. When the external container 90 is attached to the injection portion 62 (see FIG. 12 ), the plug member 92a is pushed inward by the tubular member 63, opening the ink discharge path 93. With the ink discharge path 93 open, ink 94, a portion of the ink Q contained in the reservoir 96 in the external container 90, flows in the −Z direction through the gap between the inner surface of the ink discharge path 93 and the plug member 92a and reaches the tubular member 63. The plug member 92a is pushed up by contact with the partition member 63c of the tubular member 63. In this embodiment, the partition member 63c extends to the upper end of the tubular member 63. Therefore, when the partition member 63c contacts the spherical plug member 92a, the first flow path 63a and the second flow path 63b can be maintained in an open state. The curvature of the plug member 92a in this embodiment is set so that the first flow path 63a and the second flow path 63b are opened when the partition member 63c contacts the plug member 92a.

[0038] The ink 94 that reaches the tubular member 63 flows into the first flow path 63a of the tubular member 63 and is poured into the storage portion 61. When the ink 94 is poured into the storage portion 61, gas 95 equivalent to the volume of the poured ink 94 is discharged from the second flow path 63b toward the external container 90. The gas 95 discharged toward the external container 90 flows in the +Z direction through the gap between the inner surface of the ink discharge path 93 and the plug member 92a and is stored in the storage portion 96. In this manner, gas-liquid substitution is performed within the storage portion 61 using the first flow path 63a and the second flow path 63b of the tubular member 63, thereby replenishing the ink 94 within the storage portion 61. Injection of the ink 94 by gas-liquid substitution can be continued until the liquid level of the ink 94 reaches a position that blocks the second flow path 63b of the tubular member 63. After the injection of the ink 94 is completed, the external container 90 is removed from the injection portion 62, and the tubular member 63 is closed with a lid or the like. Thereafter, the above printing operation is carried out.

[0039] As described above, the printing device 100 according to this embodiment comprises a carriage 31 that is movable in the main scanning direction along the mounting surface 22a and that carries thereon a mounting surface 22a on which the media M is placed, a head 34 that ejects ink toward the mounting surface 22a, and an ink supply unit 35 that is disposed above the head 34 and supplies ink to the head 34. The ink supply unit 35 has one or more ink tanks 36 that have a storage unit 61 that stores ink and an injection unit 62 for injecting ink stored in an external container 90 into the storage unit 61, and an ink circulation path 40 that is provided for each ink tank 36 and includes an ink supply path 37 that supplies the ink stored in the storage unit 61 to the head 34, and an ink return path 38 that returns the ink supplied to the head 34 to the storage unit 61 of the ink tank 36.

[0040] With this configuration, the head 34 and ink supply unit 35 are mounted on the carriage 31, allowing the printing device 100 to be made compact as a whole. Also, by installing the ink tank 36 in the ink supply unit 35 and supplying ink from the external container 90 to the storage unit 61 via the injection unit 62, ink can be consumed more efficiently than in a cartridge-replacement type configuration. Also, by returning the ink supplied to the head 34 through the ink return path 38, settling of ink components can be prevented.

[0041] In the printing device 100 according to this embodiment, the injection section 62 has a tubular member 63 that is provided between the storage section 61 and the outside, and has a first flow path 63a and a second flow path 63b that are arranged in parallel and connect the storage section 61 to the outside, the first flow path 63a allowing the injected ink to flow into the interior of the storage section 61, and the second flow path 63b discharging the gas inside the storage section 61 to the outside.

[0042] According to this configuration, it is possible to introduce ink using the first flow path 63a and to exhaust gas inside the storage section 61 to the outside using the second flow path 63b, and ink can be efficiently injected into the storage section 61 by gas-liquid substitution, thereby enabling efficient ink replenishment.

[0043] In the printing device 100 according to this embodiment, the storage section 61 has a float sensor 65 that measures the amount of ink stored therein. The float sensor 65 has a float 65a that is disposed inside the storage section 61 and floats on the ink surface, guide members 65b that are disposed on both sides of the float 65a in the main scanning direction and that guide the movement of the float 65a in the vertical direction, and a detection section 65c that detects the vertical position of the float 65a.

[0044] This configuration makes it possible to properly measure the amount of ink contained in the container 61. Furthermore, the guide member 65b can prevent the float 65a from shifting in the main scanning direction.

[0045] In the printing device 100 according to this embodiment, the ink supply path 37 has a supply flow path 71 that connects the storage section 61 and the head 34, and a supply valve 72 that opens and closes the supply flow path 71, and the supply valve 72 is positioned below the ink tank 36.

[0046] According to this configuration, the supply flow passage 71 and the supply valve 72 of the ink supply path 37 can be efficiently arranged in a limited space.

[0047] In the printing device 100 according to this embodiment, the ink tanks 36 are arranged in a line in the left-right direction, and the main body portions of the supply valves 72 are rectangular in shape, extending in one direction when viewed from below, and are arranged inclined in the same direction relative to the front-to-rear direction.

[0048] This configuration allows the ink tank 36 and the supply valve 72 to be arranged compactly in the left-right direction.

[0049] In the printing device 100 according to this embodiment, the damper side portion 71b of the supply flow path 71 downstream of the supply valve 72 extends downward from the front end of the supply valve 72, and an ink absorbing member 39 that absorbs ink is disposed below the connection between the supply valve 72 and the damper side portion 71b.

[0050] This configuration allows for efficient placement of the supply flow path 71. Furthermore, even if ink leaks from the connection between the supply valve 72 and the damper side portion 71b, the ink absorbing member 39 can adequately absorb it.

[0051] In the printing device 100 according to this embodiment, the ink return channel 38 is disposed on the rear side of the ink supply channel 37 .

[0052] This configuration allows the ink supply path 37 and the ink return path 38 to be efficiently arranged in a limited space.

[0053] In the printing device 100 according to this embodiment, the ink reflux path 38 has a reflux path 81 that connects the damper 73 provided in the ink supply path 37 to the storage section 61, a reflux valve 82 that opens and closes the reflux path 81, and a reflux pump 83 that is provided on the reflux path 81 downstream of the reflux valve 82 and moves ink from the damper side to the storage section 61 side.

[0054] According to this configuration, the reflux flow path 81, the reflux valve 82, and the reflux pump 83 can appropriately reflux the ink.

[0055] In the printing device 100 according to this embodiment, the ink supply path 37 has a supply flow path 71 that connects the storage section 61 and the head 34, and a supply valve 72 that opens and closes the supply flow path 71, and the reflux valve 82 is positioned on the rear side of the supply valve 72 and below the supply valve 72.

[0056] This configuration allows the supply valve 72 and the return valve 82 to be efficiently arranged in a limited space.

[0057] In the printing device 100 according to this embodiment, the reflux pump 83 is disposed on the rear side of the ink tank 36 .

[0058] This configuration allows the reflux pump 83 to be efficiently arranged in a limited space.

[0059] In the printing device 100 according to this embodiment, a tank side portion 81c of the reflux flow path 81 downstream of the reflux pump 83 extends upward from the reflux pump 83 and is connected to the ink tank 36 on the front side.

[0060] According to this configuration, the reflux pump 83 disposed on the rear side of the ink tank 36 is connected to the ink tank 36 via the tank-side portion 81c, so that the length of the tank-side portion 81c can be reduced.

[0061] The technical scope of the present invention is not limited to the above-described embodiment, and appropriate modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the medium M is paper, cloth, film, plate material, etc., but the medium M may also be food such as confectionery. In this case, the ink ejected from the printing device 100 may be edible ink.

[0062] In the above embodiment, the placement surface 22a of the table 22 is used as an example of the placement surface on which the media M is placed, but the present invention is not limited to this configuration. The placement surface on which the media M is placed may be the placement surface of a structure other than a table, such as a belt conveyor.

[0063] M...media, CONT...control unit, Q, 94...ink, 10...housing, 20...table unit, 21...base, 22...table, 22a, 25a...mounting surface, 23...table drive unit, 30...image forming unit, 31...carriage, 32...guide bar, 33...cover, 33a...front unit, 33b...side unit, 33c...bottom unit, 33d...top unit, 33e...opening, 33f...lid unit, 33g...rib, 33s...inclined portion, 34...head, 34L...nozzle row, 34N...nozzle, 35...ink supply unit, 36...ink tank, 37...ink supply path, 38...ink return path, 39...ink absorbing member, 40...ink circulation path, 50... Maintenance section, 61...storage section, 62...injection section, 63...tubular member, 63a...first flow path, 63b...second flow path, 64...absorbing member, 65...float sensor, 65a...float, 65b...guide member, 65c...detection section, 71...supply flow path, 71a, 81c...tank side section, 71b, 81a...damper side section, 72...supply valve, 73...damper, 73a...ink chamber, 81...return flow path, 81b...intermediate section, 82...return valve, 83...return pump, 90...external container, 91...ink discharge port, 92...opening / closing mechanism, 92a...plug member, 92b...elastic member, 93...ink discharge path, 95...gas, 96...storage section, 100...printing device

Claims

1. A printing device comprising: a mounting surface on which media is placed; and a carriage that is movable in a main scanning direction along the mounting surface and that carries a head that ejects ink toward the mounting surface and an ink supply unit that is arranged above the head and supplies the ink to the head, wherein the ink supply unit has one or more ink tanks that have a storage unit that stores the ink and an injection unit that injects the ink stored in an external container into the storage unit; and an ink circulation path that is provided for each ink tank and includes an ink supply path that supplies the ink stored in the storage unit to the head and an ink return path that returns the ink supplied to the head to the storage unit of the ink tank.

2. The printing device described in claim 1, wherein the injection section has a tubular member provided between the storage section and the outside, and in which a first flow path and a second flow path that communicate between the storage section and the outside are provided in parallel, the first flow path allowing the injected ink to flow into the storage section, and the second flow path discharging gas inside the storage section to the outside.

3. A printing device as described in claim 1, wherein the storage section has a float sensor that measures the amount of ink stored therein, and the float sensor has a float that is arranged inside the storage section and floats on the surface of the ink, guide members that are arranged on both sides of the float in the main scanning direction and guide the movement of the float in the vertical direction, and a detection section that detects the vertical position of the float.

4. The printing device according to claim 1, wherein the ink supply path has a supply flow path that connects the storage section and the head, and a supply valve that opens and closes the supply flow path, and the supply valve is disposed below the ink tank.

5. The printing device according to claim 4, wherein the ink tanks and supply valves are arranged in a line in the left-right direction of the device, and the main body of each supply valve is rectangular and extends in one direction when viewed from below, and is arranged inclined in the same direction relative to the front and back of the device.

6. A printing device as described in claim 4, wherein the head side portion of the supply flow path, which is the portion downstream of the supply valve, extends downward from the end of the supply valve on the front side of the device, and an ink absorbing member that absorbs the ink is located below the connection between the supply valve and the head side portion.

7. The printing device according to claim 1, wherein the ink return path is disposed on the rear side of the device relative to the ink supply path.

8. A printing device as described in claim 7, wherein the ink return path comprises a return path connecting a damper provided in the ink supply path to the storage section, a return valve that opens and closes the return path, and a return pump that is provided in the return path downstream of the return valve and moves the ink in the return path from the damper toward the storage section.

9. A printing device as described in claim 8, wherein the ink supply path has a supply flow path that connects the storage section and the head, and a supply valve that opens and closes the supply flow path, and the reflux valve is positioned on the rear side of the supply valve and below the supply valve.

10. The printing device according to claim 8, wherein the reflux pump is disposed on the rear side of the ink tank in the device.

11. A printing device according to claim 10, wherein the tank side portion of the reflux flow path, which is downstream of the reflux pump, extends upward from the reflux pump and is connected to the ink tank on the front side.

Images