Printer

Abstract

To provide a printer configured so that air can be suppressed from remaining in an ink flow passage.SOLUTION: A printer comprises: an ink container 61; an ink head 41; an ink flow passage 81; a liquid feeding pump 83, provided on the ink flow passage 81, which feeds ink in a direction from the ink container 61 toward the ink head 41; a return pump 84, provided on the ink flow passage 81, which feeds ink in a direction from the ink head 41 toward the ink container 61; and a pressure reduction device 70 that draws ink in the ink container 61 into the ink flow passage 81 and the ink head 41. The ink flow passage 81 includes a first flow passage 81b provided with the liquid feeding pump 83 and a second flow passage 81c provided with the return pump 84. A control device comprises: a first control part that drives the pressure reduction device 70 so that ink flows at a predetermined first flow rate; a second control part that drives the liquid feeding pump 83 so that ink is fed at a second flow rate that is lower than the first flow rate; and a third control part that opens an outlet of the return pump 84.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a printer.

Background Art

[0002] Printers that eject ink from an ink head to perform printing have been known. For example, Patent Document 1 discloses an inkjet recording apparatus including a recording head that ejects ink, a detachable ink container, and a tube that connects the recording head and the ink container. The inkjet recording apparatus described in Patent Document 1 includes a cap member that presses against a nozzle opening of the recording head, and a suction pump connected to the cap member. According to Patent Document 1, when using a newly purchased inkjet recording apparatus, an initial ink filling operation is performed by driving the suction pump to suck the ink in the ink container through the recording head and filling the recording head with ink.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The inventors of the present application have conceived a printer in which a liquid feed pump that sends ink from an ink container toward an ink head and a return pump that sends ink from the ink head toward the ink container are provided in an ink flow path. In such a printer, the ink flow path includes a flow path where the liquid feed pump is provided and a flow path where the return pump is provided. In a printer having an ink flow path in which a part branches off into an ink flow path provided with the liquid feed pump and an ink flow path provided with the return pump, when the ink is sucked by a decompression device to perform initial ink filling, the ink flows through the ink flow path that was filled with ink earlier, and the other ink flow path is not filled with ink. Therefore, air remains in the ink flow path.

[0005] The present invention has been made in view of such a point, and an object thereof is to provide a printer having an ink flow path in which a part branches off into an ink flow path provided with a liquid feed pump that sends ink from an ink container toward an ink head and an ink flow path provided with a return pump that sends ink from the ink head toward the ink container, and capable of suppressing the remaining air in the ink flow path.

Means for Solving the Problems

[0006] The printer disclosed herein includes an ink container that stores ink, an ink head having a plurality of nozzles from which the ink is ejected, an ink flow path that connects the ink container and the ink head and allows the ink container and the plurality of nozzles to communicate with each other, a liquid feeding pump provided in the ink flow path that sends the ink in a direction from the ink container toward the ink head, a return pump provided in the ink flow path that sends the ink in a direction from the ink head toward the ink container, a decompression device that decompresses inside the plurality of nozzles and draws the ink in the ink container into the ink flow path and the ink head, and a control device that opens, closes, drives, or stops the liquid feeding pump, opens, closes, drives, or stops the return pump, and drives or stops the decompression device. The ink flow path includes a first flow path in which the liquid feeding pump is provided, a second flow path in which the return pump is provided, a common flow path having one end connected to the ink head, a first branch portion connected to one end of the first flow path and one end of the second flow path and communicating with the ink container, and a second branch portion connected to the other end of the first flow path, the other end of the second flow path, and the other end of the common flow path. The control device includes a first control portion that drives the decompression device so that the ink flows through the common flow path at a predetermined first flow rate, a second control portion that drives the liquid feeding pump so that the ink is sent at a second flow rate that is less than the first flow rate during at least a part of the time when the decompression device is driven by the first control portion, and a third control portion that opens the return pump during at least a part of the time when the liquid feeding pump is driven by the second control portion.

[0007] According to the above printer, the second flow rate, which is the flow rate of the ink sent by the liquid sending pump, is set to be smaller than the first flow rate, which is the flow rate of the ink drawn in by the pressure reducing device. Therefore, the ink flowing through the first flow path alone cannot supply the amount of ink that the pressure reducing device tries to draw in. The insufficient ink flows through the second flow path. As a result, the second flow path is filled with ink. On the other hand, the liquid sending pump forcibly sends the ink at the second flow rate into the first flow path. Therefore, the first flow path is also filled with ink. As a result, the first flow path and the second flow path are filled with ink, and the remaining ink in the ink flow path can be suppressed.

[0008] Other printers disclosed herein include an ink container for storing ink, an ink head having a plurality of nozzles for discharging ink, an ink flow path connecting the ink container and the ink head and communicating the ink container with the plurality of nozzles, a liquid feeding pump provided in the ink flow path for sending ink in a direction from the ink container toward the ink head, a return pump provided in the ink flow path for sending ink in a direction from the ink head toward the ink container, a decompression device for decompressing inside the plurality of nozzles and drawing ink in the ink container into the ink flow path and the ink head, and a control device for opening, closing, driving, or stopping the liquid feeding pump, opening, closing, driving, or stopping the return pump, and driving or stopping the decompression device. The ink flow path includes a first flow path provided with the liquid feeding pump, a second flow path provided with the return pump, a common flow path having one end connected to the ink head, a first branch portion connected to one end of the first flow path and one end of the second flow path and communicating with the ink container, and a second branch portion connected to the other end of the first flow path, the other end of the second flow path, and the other end of the common flow path. The control device includes a first control portion for driving the decompression device so that ink is drawn into the ink flow path and the ink head, a second control portion for opening and closing the liquid feeding pump at least once during at least a part of the time when the decompression device is driven by the first control portion, and a third control portion for opening the return pump during at least a part of the time when the liquid feeding pump is closed by the second control portion and closing the return pump during at least a part of the time when the liquid feeding pump is opened by the second control portion.

[0009] The above printer can also suppress the ink remaining in the ink flow path. According to the above printer, the liquid feeding pump and the decompression pump are alternately opened and closed at least once each. When one of the liquid feeding pump and the decompression pump is closed, the ink flows through the ink flow path provided with the other pump. Thereby, the ink flow path is filled with ink. By alternately closing the liquid feeding pump and the decompression pump, both ink flow paths can be filled with ink.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the embodiments described here are not intended to limit the present invention in particular. Also, members and parts having the same function are denoted by the same reference numerals, and redundant descriptions are omitted or simplified as appropriate.

[0012] [Configuration of Inkjet Printer] FIG. 1 is a perspective view showing an inkjet printer 10 (hereinafter simply referred to as printer 10) according to an embodiment. In the following description, unless otherwise specified, when viewing the printer 10 from the front, the direction away from the printer 10 is the front, and the direction approaching the printer 10 is the rear. Left, right, up, and down respectively mean left, right, up, and down when viewing the printer 10 from the front. Also, in the drawings, the reference signs F, Rr, L, R, U, and D respectively mean front, rear, left, right, up, and down. However, the above directions are merely defined for convenience of explanation and do not limit the installation mode of the printer 10 in any way, nor do they limit the present invention in any way.

[0013] In this embodiment, the printer 10 is an inkjet printer. In this embodiment, the "inkjet method" refers to an inkjet type by various conventionally known methods including various continuous methods such as a binary deflection method or a continuous deflection method, and various on-demand methods such as a thermal method or a piezoelectric element method.

[0014] As shown in FIG. 1, the printer 10 is formed in a box shape. In this embodiment, the printer 10 includes a case 11 and a front cover 12. FIG. 2 is a front view showing the printer 10 with the front cover 12 opened. As shown in FIG. 2, an opening is formed in the front part of the case 11. The front cover 12 is provided to be able to open and close the opening of the case 11. Here, the front cover 12 is supported by the case 11 so as to be rotatable about the rear end as an axis. A window portion 12a is provided on the front cover 12. The window portion 12a is formed of, for example, a transparent acrylic plate. The user can visually recognize the internal space of the case 11 through the window portion 12a.

[0015] As shown in FIG. 2, inside the internal space of the printer 10, there are provided a flatbed 20, a bed moving device 25, a carriage 30, a carriage moving device 35, a recording head 40, a light irradiation device 50, an ink cartridge accommodating portion 60, a capping device 70, and a control device 100 (see FIG. 1). The printer 10 includes an ink supply system 80 that supplies the ink in the ink cartridge 61 accommodated in the ink cartridge accommodating portion 60 to the recording head 40.

[0016] The flatbed 20 is a support base that supports the recording medium 5. The printer 10 according to the present embodiment is a so-called flatbed type printer. The flatbed 20 is a flat plate-shaped member. The shape of the recording medium 5 is not particularly limited, and in addition to a flat plate shape, it may have various three-dimensional shapes. Also, the material of the recording medium 5 is not particularly limited, and the recording medium 5 may be, for example, wood, metal, glass, paper, cloth, or the like. The flatbed 20 is disposed approximately at the center in the left-right direction within the internal space of the case 11.

[0017] Below the flatbed 20, the bed moving device 25 is disposed. The bed moving device 25 moves the flatbed 20 in the front-rear direction and the up-down direction. The flatbed 20 is supported from below by the bed moving device 25. The bed moving device 25 includes a front-rear direction moving device 26 and an up-down direction moving device 27. The up-down direction moving device 27 supports the flatbed 20 and moves it in the up-down direction. The up-down direction moving device 27 is supported from below by the front-rear direction moving device 26. The front-rear direction moving device 26 supports the up-down direction moving device 27 and moves it in the front-rear direction. However, the configuration of the bed moving device 25 is not limited. For example, the front-rear direction moving device 26 and the up-down direction moving device 27 may have an inverted up-down positional relationship.

[0018] The carriage 30 mounts a recording head 40 and a light irradiation device 50. The carriage 30 is provided above the flatbed 20. The carriage 30 is moved in the left - right direction by a carriage moving device 35. The carriage moving device 35 includes a guide rail 36, a belt 37, left and right pulleys (not shown), and a carriage motor 38 (see FIG. 5).

[0019] As shown in FIG. 2, the guide rail 36 extends in the left - right direction. The carriage 30 is slidably engaged with the guide rail 36. An endless belt 37 is fixed to the carriage 30. The belt 37 is wound around pulleys (not shown) provided on the right side and the left side of the guide rail 36. A carriage motor 38 is attached to one of the pulleys. When the carriage motor 38 is driven, the pulley rotates and the belt 37 runs. Thereby, the carriage 30 moves in the left - right direction along the guide rail 36.

[0020] As shown in FIG. 2, the recording head 40 is provided on the lower surface of the carriage 30. The recording head 40 is provided above the flatbed 20. The recording head 40 includes a plurality of ink heads 41. The plurality of ink heads 41 are arranged side by side in the left - right direction. Although not shown, the plurality of ink heads 41 all extend in the front - rear direction. The plurality of ink heads 41 each have a plurality of nozzles 42 (see FIG. 3) from which ink is ejected. The lower surfaces of the plurality of ink heads 41 constitute a nozzle surface on which the plurality of nozzles 42 are formed.

[0021] In this embodiment, the ink ejected from the nozzles 42 of the recording head 40 is a photocurable ink. Here, the photocurable ink is an ultraviolet - curable ink that cures when irradiated with ultraviolet light. However, the components, properties, etc. of the ink are not particularly limited. The ink may be, for example, a thermosetting ink.

[0022] The light irradiation device 50 is provided to the left of the recording head 40. The light irradiation device 50 irradiates light for curing the photocurable ink toward the flat bed 20. The light irradiation device 50 has, for example, a light source (not shown) composed of a plurality of ultraviolet irradiation LEDs. The light irradiation device 50 is provided with an irradiation port (not shown) that opens downward and transmits the light generated by the light source.

[0023] The ink cartridge accommodating portion 60 is configured to be able to accommodate a plurality of ink cartridges 61. The ink cartridge 61 is an example of an ink container in which ink is accommodated. A pouch in which ink is stored is housed in the ink cartridge 61. The ink cartridge 61 is detachably attached to the ink cartridge accommodating portion 60. However, the ink container is not limited to the ink cartridge 61, and may be, for example, a container in which ink poured from a pouch, a bottle, or the like is stored.

[0024] The capping device 70 includes a plurality of caps 71, a cap moving device 72, and a plurality of suction pumps 73. FIG. 3 is a schematic diagram showing the configuration of the ink supply system 80 and the capping device 70. As shown in FIG. 3, the cap 71 and the suction pump 73 are provided one by one for the ink head 41. The number of cap moving devices 72 is one here. The cap 71 is configured to be attachable to the ink head 41. The cap 71 has a container-like shape with an open upper surface. The cap 71 is formed of rubber or the like. When attached to the ink head 41, the upper edge of the cap 71 is in close contact with the nozzle surface of the ink head 41. The cap 71 is attached to the ink head 41 to protect the ink head 41 and prevent its drying. Ink is discharged timely for the maintenance of the nozzle 42 with respect to the cap 71.

[0025] The plurality of caps 71 are supported by a cap moving device 72. The cap moving device 72 mounts or separates the plurality of caps 71 from the nozzle surface of the ink head 41. The cap moving device 72 supports the plurality of caps 71 from below and moves them in the vertical direction. Thereby, the cap 71 is mounted on and separated from the ink head 41. The cap moving device 72 includes, for example, a drive motor (not shown). In the present embodiment, the cap moving device 72 moves the cap 71 in the vertical direction to mount it on the ink head 41, but it may be configured to mount it by sliding obliquely, for example.

[0026] As shown in FIG. 3, a suction pump 73 is connected to the cap 71. The suction pump 73 reduces the pressure inside the cap 71 in a state where the cap 71 is mounted on the ink head 41. The suction pump 73 thereby discharges the ink inside the cap 71. The suction pump 73 is, for example, a vacuum pump.

[0027] The capping device 70 can also suck the ink in the ink supply system 80 and the recording head 40 through the nozzles 42 of the ink head 41. As will be described later, in the initial filling mode used when the capping device 70 fills the ink flow path 81 of the ink supply system 80 and the ink head 41 with ink from a state where they are not filled with ink, the capping device 70 also functions as a decompression device that decompresses inside the plurality of nozzles 42 and draws the ink in the ink cartridge 61 into the ink flow path 81 and the ink head 41. Note that the capping device 70 may suck the ink from the nozzles 42 as one of the maintenance operations of the nozzles 42.

[0028] The ink supply system 80 supplies the ink stored in the ink cartridge 61 to the recording head 40. As shown in FIG. 3, one system is provided for one ink cartridge 61 in the ink supply system 80. In the present embodiment, a plurality of systems of the ink supply system 80 are connected to one ink head 41. However, one system of the ink supply system 80 may be connected to one ink head 41.

[0029] As shown in FIG. 3, each ink supply system 80 includes an ink flow path 81, a valve 82, a liquid feed pump 83, a decompression pump 84, and a damper 85 (however, only the configuration of one ink supply system 80 is illustrated in FIG. 3). The ink flow path 81 connects the ink cartridge 61 and the ink head 41, and communicates the ink cartridge 61 with a plurality of nozzles 42. The valve 82 is provided in the ink flow path 81 and opens or closes the ink flow path 81. The liquid feed pump 83 is provided in the ink flow path 81 and sends ink in the direction from the ink cartridge 61 toward the ink head 41. The decompression pump 84 is provided in the ink flow path 81 and sends ink in the direction from the ink head 41 toward the ink cartridge 61. The decompression pump 84 is a pump that returns ink toward the ink cartridge 61. The damper 85 includes an intermediate container in which ink is stored and alleviates pressure fluctuations of the ink.

[0030] As shown in FIG. 3, the ink flow path 81 includes an upstream common flow path 81a, a first flow path 81b and a second flow path 81c branched from the upstream common flow path 81a, and a downstream common flow path 81d where the first flow path 81b and the second flow path 81c merge. The ink flow path 81 includes a first branch portion 81e that branches the upstream common flow path 81a into the first flow path 81b and the second flow path 81c, and a second branch portion 81f that merges the first flow path 81b and the second flow path 81c into the downstream common flow path 81d. In the present embodiment, the upstream common flow path 81a, the first flow path 81b, the second flow path 81c, and the downstream common flow path 81d are formed of flexible tubes. However, these flow paths are not limited to tubes and may be formed of, for example, shaped pipes.

[0031] As shown in FIG. 3, the upstream end of the upstream common flow path 81a is connected to the ink cartridge 61. The downstream end of the upstream common flow path 81a is connected to the first branch portion 81e. A valve 82 is provided in the upstream common flow path 81a. The upstream ends of the first flow path 81b and the second flow path 81c are connected to the first branch portion 81e. Here, the first branch portion 81e is composed of a tube joint that branches in three directions. A liquid feed pump 83 is provided in the first flow path 81b. A pressure reducing pump 84 is provided in the second flow path 81c.

[0032] The downstream ends of the first flow path 81b and the second flow path 81c are connected to the second branch portion 81f. Further, the upstream end of the downstream common flow path 81d is connected to the second branch portion 81f. The second branch portion 81f is also composed of a tube joint that branches in three directions. The downstream end of the downstream common flow path 81d is connected to the ink head 41. A damper 85 is provided in the downstream common flow path 81d.

[0033] The liquid feed pump 83 is a pump capable of opening / closing the flow path and driving / stopping. In the present embodiment, the liquid feed pump 83 is a tube pump. FIG. 5 is a schematic cross-sectional view of the liquid feed pump 83. As shown in FIG. 4, the liquid feed pump 83 includes an internal flow path 83a, a pair of rollers 83b, an arm 83c, a motor 83d, and a roller retracting mechanism 83e.

[0034] The internal flow path 83a is composed of a flexible tube. The internal flow path 83a is a member through which ink passes. Both ends of the internal flow path 83a are connected to the first flow path 81b. The liquid feed pump 83 sends out ink by squeezing the internal flow path 83a with a pair of rollers 83b. As shown in FIG. 5, the pair of rollers 83b are respectively arranged at both ends of the arm 83c. The motor 83d rotates the arm 83c so that the pair of rollers 83b move along the arc-shaped portion of the internal flow path 83a. Thereby, the pair of rollers 83b squeeze the internal flow path 83a.

[0035] The motor 83d rotates the arm 83c by an angle corresponding to the command from the control device 100. Thereby, the liquid feeding pump 83 can send an amount of ink corresponding to the command from the control device 100. As will be described later, when the liquid feeding pump 83 supplies the ink consumed during printing to the ink head 41, it sends an amount of ink corresponding to the command from the control device 100 each time a command is issued. When the liquid feeding pump 83 initially fills the ink into the ink flow path 81 and the ink head 41, it intermittently rotates the arm 83c so that the amount of ink sent per unit time (hereinafter referred to as the flow rate) is set to a set flow rate. The ink flow rate per unit time changes according to the ratio of the time when the arm 83c is rotating to the time when it is stopped.

[0036] The liquid feeding pump 83 is configured to be switchable between an open state in which the internal flow path 83a is open and a closed state in which the internal flow path 83a is closed by the roller 83b. The roller retracting mechanism 83e crushes the internal flow path 83a with the pair of rollers 83b, or separates the pair of rollers 83b from the internal flow path 83a. The roller retracting mechanism 83e is configured to separate the pair of rollers 83b from the internal flow path 83a by rotating the motor 83d in the reverse direction. As shown in FIG. 4, in the present embodiment, the roller retracting mechanism 83e includes a pair of rubber plates 83e1 and 83e2. When the motor 83d is rotated in the reverse direction, the roller 83b is moved to a position separated from the internal flow path 83a by the rubber plates 83e1 and 83e2. Thereby, the liquid feeding pump 83 is opened. When the motor 83d is rotated forward from the state where the liquid feeding pump 83 is opened, the roller 83b is moved to a position where it crushes the internal flow path 83a by the rubber plates 83e1 and 83e2. Thereby, the liquid feeding pump 83 is closed. The liquid feeding pump 83 is configured to send ink by driving the motor 83d in the closed state. Specifically, when the motor 83d is rotated forward in the closed state, ink is sent.

[0037] The liquid feed pump 83 is configured to be able to open, close, and send ink through the internal flow path 83a. "Stopping the liquid feed pump 83" means not driving the motor 83d after closing the internal flow path 83a, which is the same as closing the internal flow path 83a here. The liquid feed pump 83 is configured so that it cannot send ink in the reverse direction.

[0038] In this embodiment, the decompression pump 84 is also configured in the same way as the liquid feed pump 83. The decompression pump 84 is also configured to be able to open / close the flow path and drive / stop. However, the liquid feed pump 83 and the decompression pump 84 are not limited to tube pumps. The liquid feed pump 83 and the decompression pump 84 may have different configurations.

[0039] As shown in FIG. 3, the damper 85 includes an ink storage portion 85a where ink is stored and a pressure sensor 85b that measures the pressure of the ink in the ink storage portion 85a. When the pressure sensor 85b detects that the ink in the ink storage portion 85a has increased and the pressure of the ink in the ink storage portion 85a has reached a predetermined pressure or more, the ink supply system 80 stops the liquid feed pump 83. When the pressure sensor 85b detects that the pressure of the ink in the ink storage portion 85a has become less than the predetermined pressure due to the consumption of the ink, the ink supply system 80 drives the liquid feed pump 83. The ink supply system 80 supplies ink to the ink head 41 while repeatedly driving and stopping the liquid feed pump 83. However, the mechanism for detecting the pressure of the ink in the damper 85 is not limited to the above-described one. The damper 85 may include, for example, a damper film that forms one surface of the ink storage portion and expands and contracts according to the pressure of the ink, and a detection portion that detects when the damper film expands outward by a predetermined amount or more. In this case, the printer 10 may be configured to stop the liquid feed pump 83 when the detection portion detects that the expansion of the damper film has reached a predetermined amount or more, and drive the liquid feed pump 83 when the detection portion detects that the expansion of the damper film has become less than the predetermined amount.

[0040] FIG. 5 is a block diagram of the printer 10. As shown in FIG. 5, the control device 100 is electrically connected to the front-rear direction moving device 26 and the up-down direction moving device 27 of the bed moving device 25, the carriage motor 38 of the carriage moving device 35, a plurality of ink heads 41 (only one is shown in FIG. 5), the light irradiation device 50, the cap moving device 72 of the capping device 70 and a plurality of suction pumps 73 (only one is shown in FIG. 5), and the valve 82, the liquid feeding pump 83, and the decompression pump 84 (only one of each is shown in FIG. 5) of the ink supply system 80, and controls their operations. Further, the control device 100 is electrically connected to the pressure sensor 85b of the damper 85 (only one is shown in FIG. 5) and receives a signal transmitted by the pressure sensor 85b. The control device 100 is, for example, a microcomputer and may include a central processing unit (hereinafter referred to as CPU), a ROM storing programs executed by the CPU, a RAM, and the like. Each part of the control device 100 may be configured by software or by hardware. Further, each part may be a processor or a circuit. The configuration of the control device 100 is not particularly limited.

[0041] As shown in FIG. 5, the control device 100 includes a supply control unit 110, a purge control unit 120, and an initial filling control unit 130 as control units for controlling the supply of ink to the ink flow path 81 and the ink head 41. The control device 100 opens, closes, drives, or stops the liquid feeding pump 83. The control device 100 also opens, closes, drives, or stops the decompression pump 84. The control device 100 drives or stops the capping device 70. The control device 100 includes a mode input unit 140 that can select an initial filling mode used when filling the ink flow path 81 and the ink head 41 with ink from a state where the ink flow path 81 and the ink head 41 are not filled with ink. Note that the control device 100 may include other control units such as a control unit for controlling a printing operation, but the description and illustration thereof are omitted here.

[0042] When the ink supply control unit 110 determines that the ink flow path 81 and the ink head 41 are already filled with ink and are in a printable state (hereinafter also referred to as the printable state), it controls the operation of supplying ink to the ink head 41. When ink is consumed due to ink discharge for printing or maintenance, the supply control unit 110 supplies ink. Specifically, when the pressure sensor 85b detects that ink is consumed in the printable state and the pressure of the ink in the ink storage unit 85a has dropped below a predetermined pressure, the supply control unit 110 drives the liquid feed pump 83. When the pressure sensor 85b detects that ink has been supplied to the damper 85 and the pressure of the ink in the ink storage unit 85a has become equal to or higher than the predetermined pressure, the supply control unit 110 stops the liquid feed pump 83.

[0043] The purge control unit 120 controls the operation of pressure cleaning in which ink is pressurized by sending ink with the liquid feed pump 83 and discharged from the nozzles 42. The purge control unit 120 includes a pressure increase control unit 121 and a pressure decrease control unit 122. In pressure cleaning, the pressure increase control unit 121 drives the liquid feed pump 83. The pressure decrease control unit 122 drives the pressure reduction pump 84 to reduce the ink pressure in the ink flow path 81 and the ink head 41 to a printable pressure (a negative pressure at which a meniscus is formed at the nozzles 42). The pressure reduction pump 84 is a pump for returning the ink pressure in the ink flow path 81 and the ink head 41 to a printable pressure during pressure cleaning.

[0044] The initial filling control unit 130 controls the operation of initially filling the ink flow path 81 and the ink head with ink starting from a state where the ink flow path 81 and the ink head are not filled with ink. The initial filling is performed at the start of use of the printer 10 or when a large amount of ink in the ink flow path 81 has been discharged for some reason (for example, disassembly maintenance). In that case, the initial filling mode is selected by operating the mode input unit 140. The initial filling control unit 130 includes a suction control unit 131, a liquid feeding control unit 132, and an opening control unit 133. The suction control unit 131, the liquid feeding control unit 132, and the opening control unit 133 control the capping device 70, the liquid feeding pump 83, and the decompression pump 84 in the initial filling mode.

[0045] The suction control unit 131 drives the capping device 70 so that ink flows through the downstream common flow path 81d at a predetermined flow rate (hereinafter also referred to as the first flow rate). By driving the capping device 70, the inside of the nozzle 42 is depressurized, and the ink in the ink cartridge 61 is drawn into the ink flow path 81 and the ink head 41. In the initial filling, the ink flow path 81 and the ink head 41 are filled with ink by driving the capping device 70.

[0046] The liquid feeding control unit 132 drives the liquid feeding pump 83 to send ink at a predetermined flow rate (hereinafter also referred to as the second flow rate) that is less than the first flow rate for at least a part of the time when the capping device 70 is being driven by the suction control unit 131. Here, the liquid feeding control unit 132 starts driving the liquid feeding pump 83 at the same time as the suction control unit 131 drives the capping device 70, and stops the liquid feeding pump 83 before the suction control unit 131 stops the capping device 70. However, the liquid feeding control unit 132 only needs to drive the liquid feeding pump 83 for at least a part of the time when the capping device 70 is being driven by the suction control unit 131, as long as it is sufficient time for the air in the ink flow path 81 to escape (the method of removing the air in the ink flow path 81 will be described later). Note that the liquid feeding control unit 132 may start driving the liquid feeding pump 83 before the suction control unit 131 drives the capping device 70.

[0047] The second flow rate is preferably set to be 40% or more and 60% or less of the first flow rate. In the present embodiment, the second flow rate is set to be half or approximately half of the first flow rate. Here, the first flow rate means the flow rate flowing through one system of the ink flow path 81. The total flow rate of the ink that can be made to flow by driving the capping device 70, that is, the liquid feeding ability of the capping device 70 is known in advance. The flow rate flowing through one system of the ink flow path 81 is obtained by dividing the above total flow rate by the number (number of systems) of the ink flow paths 81 connected to one capping device 70. Note that the second flow rate is not particularly limited as long as it is set to be smaller than the first flow rate. The second flow rate may be less than 40% of the first flow rate, or may exceed 60% of the first flow rate.

[0048] The opening control unit 133 opens the pressure reducing pump 84 at least for a part of the time during which the liquid feeding pump 83 is driven by the liquid feeding control unit 132. In the present embodiment, the opening control unit 133 opens the pressure reducing pump 84 before the suction control unit 131 drives the capping device 70. The pressure reducing pump 84 is opened before the start of use of the printer 10 so that the internal flow path is not crushed irreversibly (similarly, the liquid feeding pump 83 is also opened before the start of use of the printer 10). The opening control unit 133 may only perform the opening of the pressure reducing pump 84 before such use, or may perform control to open the pressure reducing pump 84 again after the suction control unit 131 drives the capping device 70 during the initial filling. Note that the opening control unit 133 may open the pressure reducing pump 84 at the same time as the suction control unit 131 drives the capping device 70. The opening control unit 133 may open the pressure reducing pump 84 before or after the liquid feeding control unit 132 drives the liquid feeding pump 83, or may open the pressure reducing pump 84 at the same time as the liquid feeding control unit 132 drives the liquid feeding pump 83.

[0049] [Process of Initial Filling] Hereinafter, the process of initial filling will be described. Also, the effects achieved by driving the liquid feeding pump 83 and opening the pressure reducing pump 84 during the initial filling will be described.

[0050] FIG. 6 is a flowchart of initial ink filling. As shown in FIG. 6, in step S01 of initial ink filling, a cap 71 is attached to each ink head 41. In step S02, a suction pump 73 is driven. In step S03, a liquid feed pump 83 is driven. Here, the liquid feed pump 83 is open before step S01, and the liquid feed pump 83 is first closed when it is driven. The vacuum pump 84 is also open before step S01. In the present embodiment, steps S02 and S03 are started simultaneously. However, step S03 may be started before step S02 as long as ink does not overflow from the cap 71 because the suction pump 73 is not driven.

[0051] Hereinafter, mainly with reference to FIG. 3, the effects achieved by driving the liquid feed pump 83 and opening the vacuum pump 84 during initial filling will be described. When the capping device 70 (suction pump 73) is driven with the ink flow path 81 and the ink head not filled with ink, air in the ink flow path 81 is sucked through the nozzle 42, and the inside of the ink flow path 81 becomes negative pressure. As a result, the ink in the ink cartridge 61 is drawn into the ink flow path 81. The drawn ink flows into the upstream common flow path 81a, then the first flow path 81b and the second flow path 81c, further into the downstream common flow path 81d, and further into the ink head 41.

[0052] Here, assume that the liquid feed pump 83 and the vacuum pump 84 are open. When the liquid feed pump 83 and the vacuum pump 84 are open, ink flows into both the first flow path 81b and the second flow path 81c. However, if either the first flow path 81b or the second flow path 81c is filled with ink first, the ink flows through the ink flow path that was filled with ink first into the downstream common flow path 81d, and the other ink flow path is not filled with ink. As a result, air remains in the ink flow path 81. The remaining air often causes problems in the ejection of ink from the ink head 41.

[0053] In order to prevent such air from remaining, the printer 10 according to the present embodiment is configured to drive the liquid feed pump 83 and open the decompression pump 84 during initial filling. In the present embodiment, the second flow rate, which is the flow rate of the ink sent by the liquid feed pump 83, is set to be smaller than the first flow rate, which is the flow rate of the ink drawn in by the capping device 70. Therefore, the ink flowing through the first flow path 81b alone cannot supply the amount of ink that the capping device 70 attempts to draw in. The insufficient ink flows through the second flow path 81c. As a result, the second flow path 81c is filled with ink. On the other hand, the liquid feed pump 83 forcibly sends the ink at the second flow rate into the first flow path 81b. Therefore, the first flow path 81b is also filled with ink.

[0054] In the present embodiment, the second flow rate is set to be approximately half of the first flow rate (for example, 40% or more and 60% or less). Therefore, the flow rate of the ink flowing through the first flow path 81b and the flow rate of the ink flowing through the second flow path 81c are substantially the same. Thus, the first flow path 81b and the second flow path 81c are filled with ink substantially at the same time. According to such control, the amount of ink flowed until both the first flow path 81b and the second flow path 81c are filled with ink can be reduced. Therefore, the air in the ink flow path 81 can be quickly discharged. Also, for this reason, the amount of ink discarded via the suction pump 73 can be reduced.

[0055] Furthermore, in the present embodiment, the liquid feed control unit 132 drives the liquid feed pump 83 simultaneously with (or even before) the suction control unit 131 driving the capping device 70, and the opening control unit 133 opens the decompression pump 84 before (or even simultaneously with) the suction control unit 131 driving the capping device 70. Therefore, from the beginning, the flow rate of the ink flowing through the first flow path 81b and the flow rate of the ink flowing through the second flow path 81c are substantially the same. As a result, the amount of ink flowed until both the first flow path 81b and the second flow path 81c are filled with ink can be further reduced. As a result, the amount of ink discarded via the suction pump 73 can be further decreased.

[0056] As shown in FIG. 6, in step S04, it is determined whether or not a predetermined time has elapsed since the capping device 70 was driven in step S01. If the predetermined time has not elapsed (if the result of step S04 is NO), the state after step S03 is continued. When the predetermined time has elapsed (when the result of step S04 becomes YES), in step S05, the liquid feed pump 83 is stopped. In step S06, the decompression pump 84 is closed. Steps S05 and S06 may be performed simultaneously or in reverse order. In step S07, the suction pump 73 is stopped.

[0057] [Other initial filling processes] The above-described initial filling process is a preferred example, and the initial filling can also be carried out by other processes. For example, in the above-described embodiment, the liquid feed pump 83 was driven from the start of the initial filling. However, the liquid feed pump 83 may be opened, for example, halfway and driven from halfway. In this case, by setting the liquid feed pump 83 to the open state, after the first flow path 81b is filled with ink to a certain extent (or all depending on the conditions), the liquid feed pump 83 is driven.

[0058] If the second flow path 81c is filled with ink and air remains in the first flow path 81b, the first flow path 81b will not be filled with ink if the liquid feed pump 83 remains open. However, by driving the liquid feed pump 83 and forcibly sending the ink, the first flow path 81b is also filled with ink. If the first flow path 81b is filled with ink and air remains in the second flow path 81c, the second flow path 81c will not be filled with ink if the liquid feed pump 83 remains open. However, by driving the liquid feed pump 83 and setting the ink flow rate in the first flow path 81b to a second flow rate that is less than the first flow rate, the shortage with respect to the first flow rate flows through the second flow path 81c, and the second flow path 81c is also filled with ink.

[0059] Also, for example, by alternately opening and closing the liquid feed pump 83 and the pressure reducing pump 84 at least once each, both the first flow path 81b and the second flow path 81c can be filled with ink. In this case, the first control unit (corresponding to the suction control unit 131 in the above-described embodiment) drives the capping device 70 so that ink is drawn into the ink flow path 81 and the ink head 41. The second control unit (corresponding to the liquid feed control unit 132 in the above-described embodiment) opens and closes the liquid feed pump 83 at least once during at least a part of the time when the capping device 70 is being driven by the first control unit. The third control unit (corresponding to the opening control unit 133 in the above-described embodiment) opens the pressure reducing pump 84 during at least a part of the time when the liquid feed pump 83 is closed by the second control unit, and closes the pressure reducing pump 84 during at least a part of the time when the liquid feed pump 83 is open by the second control unit.

[0060] FIG. 7 is a flowchart of the initial filling according to the above-described method. As shown in FIG. 7, in step S11 of this process, the cap 71 is attached to each ink head 41. In step S12, the suction pump 73 is driven. At this time, the liquid feed pump 83 and the pressure reducing pump 84 are open.

[0061] When the first flow path 81b and the second flow path 81c are filled with ink to some extent by steps S11 and S12, in step S13, the liquid feed pump 83 is closed. As a result, ink no longer flows in the first flow path 81b. All of the flowing ink passes through the second flow path 81c. As a result, the second flow path 81c is filled with ink.

[0062] In the subsequent step S14, the liquid feed pump 83 is opened again. In step S15, the pressure reducing pump 84 is closed. As a result, ink no longer flows in the second flow path 81c. All of the flowing ink passes through the first flow path 81b. As a result, the first flow path 81b is filled with ink. By step S15, both the first flow path 81b and the second flow path 81c are filled with ink.

[0063] In step S16, the liquid feed pump 83 is closed. In step S17, the suction pump 73 is stopped. Thereby, the initial filling of the ink is completed. In the above-described example, the opening / closing of the liquid feed pump 83 and the opening / closing of the decompression pump 84 are each performed once, but they may be performed two or more times. Also, the opening / closing of the decompression pump 84 may be performed prior to the opening / closing of the liquid feed pump 83.

[0064] [Other Embodiments] As described above, several preferred embodiments have been explained. However, the printer of the present invention is not limited to the above-described embodiments. For example, the configuration of the ink supply system 80 is not particularly limited as long as it includes a first flow path 81b provided with a liquid feed pump 83 and a second flow path 81c provided with a decompression pump 84. FIG. 8 is a schematic diagram showing the configuration of another ink supply system 80. As shown in FIG. 8, the ink supply system 80 may be configured such that the first flow path 81b and the second flow path 81c are not integrated by an upstream common flow path and are each connected to the ink cartridge 61. In this case, the first branch portion 81e is connected to the upstream end portion of the first flow path 81b and the upstream end portion of the second flow path 81c and communicates with the ink cartridge 61, that is, the connection portion between the first flow path 81b and the second flow path 81c and the ink cartridge 61. Other pipes, other valves, etc. may be further added to the ink supply system 80, and some members may be omitted.

[0065] However, according to the configuration including the upstream common flow path 81a with its upstream end connected to the ink cartridge 61 as in the first embodiment, and with the first branch portion 81e connected to the downstream end of the upstream common flow path 81a, regardless of the arrangement of the liquid feed pump 83 and the pressure reducing pump 84, the lengths of the first flow path 81b and the second flow path 81c can be shortened. As a result, it becomes easier to discharge the air in the first flow path 81b and the second flow path 81c. In the configuration where the first flow path 81b and the second flow path 81c are not integrated by the upstream common flow path as shown in FIG. 8 and are respectively connected to the ink cartridge 61, when the liquid feed pump 83 and the pressure reducing pump 84 are arranged away from the ink cartridge 61, the lengths of the first flow path 81b and the second flow path 81c become longer. On the other hand, according to the configuration having the upstream common flow path 81a, even if the liquid feed pump 83 and the pressure reducing pump 84 are arranged away from the ink cartridge 61, only the upstream common flow path 81a becomes longer, and it is not necessary to increase the lengths of the first flow path 81b and the second flow path 81c.

[0066] In the above-described embodiment, it is not detected whether air has been discharged from the first flow path 81b and the second flow path 81c, and the initial filling is performed only for a time sufficient for air to be discharged from the first flow path 81b and the second flow path 81c. However, the ink supply system 80 may include a detection unit capable of detecting whether air has been discharged from the first flow path 81b and the second flow path 81c.

[0067] In the above-described embodiment, the pressure reducing device for reducing the pressure inside the plurality of nozzles 42 of the ink head 41 and drawing the ink in the ink cartridge 61 into the ink flow path 81 and the ink head 41 was the capping device 70. However, the pressure reducing device for initial filling is not limited to the capping device 70. For example, the printer 10 may include a dedicated pressure reducing device for initial filling.

[0068] In the above-described embodiment, the printer 10 was a flatbed type printer, but the configuration of the printer is not particularly limited. The technology disclosed herein may be applied, for example, to a printer in which a recording medium is supplied from a roll. In addition, the configuration of the above-described printer 10 is merely illustrative and is not particularly limited.

[0069] In addition, unless otherwise specified, the embodiments do not limit the present invention.

Explanation of Reference Numerals

[0070] 10 Inkjet Printer (Printer) 41 Ink Head 42 Nozzle 61 Ink Cartridge (Ink Container) 70 Capping Device (Vacuum Device) 80 Ink Supply System 81 Ink Flow Path 81a Upstream Common Flow Path (Second Common Flow Path) 81b First Flow Path 81c Second Flow Path 81d Downstream Common Flow Path (Common Flow Path) 81e First Branch Port 81f Second Branch Port 83 Liquid Feeding Pump 84 Vacuum Pump (Return Pump) 100 Control Device 131 Suction Control Unit (First Control Unit) 132 Liquid Feeding Control Unit (Second Control Unit) 133 Release Control Unit (Third Control Unit) 140 Mode Input Unit

Claims

1. An ink container containing ink, An ink head having a plurality of nozzles from which ink is ejected, An ink flow path connecting the ink container and the ink head and communicating the ink container and the plurality of nozzles, A liquid feed pump provided in the ink flow path for sending ink in a direction from the ink container toward the ink head, A return pump provided in the ink flow path for sending ink in a direction from the ink head toward the ink container, A decompression device for decompressing inside the plurality of nozzles and drawing ink in the ink container into the ink flow path and the ink head, A control device for opening, closing, driving, or stopping the liquid feed pump, opening, closing, driving, or stopping the return pump, and driving or stopping the decompression device, The ink flow path is A first flow path provided with the liquid feed pump, A second flow path provided with the return pump, A common flow path having one end connected to the ink head, A first branch portion connected to one end of the first flow path and one end of the second flow path and communicating with the ink container, Including a second branch portion connected to the other end of the first flow path, the other end of the second flow path, and the other end of the common flow path, The control device is A first control portion for driving the decompression device so that ink flows through the common flow path at a predetermined first flow rate, A second control portion for driving the liquid feed pump so as to send ink at a second flow rate less than the first flow rate at least for a part of the time during which the decompression device is driven by the first control portion, A third control portion for opening the return pump at least for a part of the time during which the liquid feed pump is driven by the second control portion, A printer.

2. The second flow rate is 40% or more and 60% or less of the first flow rate, The printer according to Claim 1.

3. The second control portion drives the liquid feed pump before or simultaneously with the first control portion driving the decompression device, The third control portion opens the return pump before or simultaneously with the first control portion driving the decompression device, The printer according to Claim 2.

4. The ink flow path includes a second common flow path having one end connected to the ink container, The first branch portion is connected to the other end of the second common flow path, The printer according to Claim 1.

5. The control device includes a mode input unit that can select an initial filling mode used when filling the ink flow path and the ink head with ink from a state where the ink flow path and the ink head are not filled with ink. The first control unit, the second control unit, and the third control unit control the decompression device, the liquid feed pump, and the return pump in the initial filling mode. The printer according to claim 1.

6. An ink container for storing ink; An ink head having a plurality of nozzles from which ink is ejected; An ink flow path that connects the ink container and the ink head and allows the ink container and the plurality of nozzles to communicate with each other; A liquid feed pump provided in the ink flow path for sending ink in a direction from the ink container toward the ink head; A return pump provided in the ink flow path for sending ink in a direction from the ink head toward the ink container; A decompression device that decompresses the inside of the plurality of nozzles and draws ink in the ink container into the ink flow path and the ink head; A control device that opens, closes, drives, or stops the liquid feed pump, opens, closes, drives, or stops the return pump, and drives or stops the decompression device. The ink flow path is A first flow path provided with the liquid feed pump; A second flow path provided with the return pump; A common flow path having one end connected to the ink head; A first branch portion connected to one end of the first flow path and one end of the second flow path and communicating with the ink container; A second branch portion connected to the other end of the first flow path, the other end of the second flow path, and the other end of the common flow path. The control device is A first control unit that drives the decompression device so that ink is drawn into the ink flow path and the ink head; A second control unit that opens and closes the liquid feed pump at least once during at least a part of the time when the decompression device is being driven by the first control unit; A third control unit that opens the return pump during at least a part of the time when the liquid feed pump is closed by the second control unit and closes the return pump during at least a part of the time when the liquid feed pump is open by the second control unit. Printer.

7. The ink flow path includes a second common flow path having one end connected to the ink container. The first branch portion is connected to the other end of the second common flow path. The printer according to claim 6.

8. The control device includes a mode input unit capable of selecting an initial filling mode used when filling the ink flow path and the ink head with ink from a state where the ink flow path and the ink head are not filled with ink. The first control unit, the second control unit, and the third control unit control the decompression device, the liquid feed pump, and the return pump in the initial filling mode. The printer according to claim 6.

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