JP7590930B2 - Inkjet printer - Google Patents

Description

The present invention relates to an inkjet printer.

For example, Patent Document 1 discloses a liquid ejection device that includes an ink tank that stores ink, a recording head that ejects ink, an ink pump that supplies ink to the ink head, and a sub-tank that has an ink chamber that temporarily stores the ink supplied from the ink pump. The sub-tank has a flexible membrane that divides the inside of the tank, which is a sealed container, into an ink chamber and a gas chamber. The flexible membrane is configured to bend toward the gas chamber when ink is supplied to the ink chamber, and to bend toward the ink chamber when the ink in the ink chamber decreases. The flexible membrane deteriorates due to contact with ink. More specifically, there is a problem in that the flexible membrane shrinks and becomes difficult to extend.

For example, Patent Document 2 discloses an inkjet printer that detects the pressure in a storage chamber based on the flexural deformation of a pressure-sensitive membrane that defines a storage chamber in which ink is temporarily stored, and supplies ink to the storage chamber from an ink supply device. More specifically, the supply of ink begins when a lever linked to the flexural deformation of the pressure-sensitive membrane blocks the detection area, and the supply of ink stops when the lever moves out of the detection area.

JP 2009-28963 A JP 2021-59087 A

In the inkjet printer described in Patent Document 2, when the pressure-sensitive membrane is normal, when a predetermined amount of ink is supplied to the storage chamber, the pressure-sensitive membrane bends outward from the storage chamber, and the lever moves out of the detection area, stopping the supply of ink. In other words, an appropriate amount of ink is stored in the storage chamber, and the pressure in the storage chamber is maintained appropriately. On the other hand, if the pressure-sensitive membrane contracts, even if a predetermined amount of ink is supplied to the storage chamber, the pressure-sensitive membrane does not bend sufficiently outward from the storage chamber, and the lever does not move out of the detection area. As a result, the supply of ink to the storage chamber continues. If excessive ink is supplied to the storage chamber, the pressure in the storage chamber will rise above the appropriate value. As a result, there is a risk that ink will leak from the nozzles of the ink head and soil the recording medium.

The present invention was made in consideration of these points, and its purpose is to provide an inkjet printer that can prevent ink from leaking from the nozzles of the ink head by determining the state of the pressure-sensitive membrane.

The inkjet printer according to the present invention has an ink head having a plurality of nozzles for ejecting ink onto a recording medium and a nozzle surface on which the plurality of nozzles are formed, an ink path having an upstream end detachably connected to an ink cartridge that stores ink, a downstream end connected to the ink head, and a middle portion located between the upstream end and the downstream end, a liquid delivery pump arranged at the middle portion and capable of delivering ink from the ink cartridge to the ink head, a case body having an opening, and a pressure-sensitive membrane attached to the case body so as to cover the opening of the case body, which defines a storage chamber in which ink is temporarily stored together with the case body and is flexible and deformable on the inside and outside of the storage chamber, and the ink path is arranged between the liquid delivery pump and the ink head. the ink head includes a damper disposed midway; a lever that moves toward the storage chamber when the pressure-sensitive membrane bends inwardly into the storage chamber and moves away from the storage chamber when the pressure-sensitive membrane bends outwardly of the storage chamber; a light-emitting unit that emits a predetermined light; a light-receiving unit that receives the light emitted from the light-emitting unit; and a detection area provided between the light-emitting unit and the light-receiving unit, and a detection device that detects that the pressure in the storage chamber is equal to or lower than a first pressure when the lever blocks the detection area; a cap that is detachably formed on the ink head and that covers the nozzle surface when attached to the ink head and forms an airtight space between the cap and the nozzle surface; a suction pump that sucks up fluid in the airtight space; and a control device that controls the ink head, the liquid delivery pump, and the suction pump. The control device includes a first ink delivery unit that delivers ink to the storage chamber at a predetermined pressure, a first suction control unit that drives the suction pump to perform a suction operation to suck the fluid in the sealed space after the ink is delivered to the storage chamber by the first ink delivery unit, an estimation unit that estimates the first ink amount that has been sucked by the suction pump until the detection device detects that the pressure in the storage chamber is equal to or lower than the first pressure, and a judgment unit that judges the state of the pressure-sensitive membrane based on the first ink amount estimated by the estimation unit.

According to the inkjet printer of the present invention, the first ink delivery unit delivers ink to the storage chamber at a predetermined pressure. Here, when the pressure-sensitive membrane is normal, the pressure-sensitive membrane bends outwardly significantly when ink is delivered to the storage chamber at a predetermined pressure. Therefore, when ink is delivered to the storage chamber and the lever is removed from the detection area, a relatively large amount of ink is stored in the storage chamber. On the other hand, when the pressure-sensitive membrane is contracted, the pressure-sensitive membrane does not bend outwardly much even when ink is delivered to the storage chamber at a predetermined pressure. Therefore, when ink is delivered to the storage chamber and the lever is removed from the detection area, a relatively small amount of ink is stored in the storage chamber. Then, the first suction control unit performs a suction operation to discharge the ink in the storage chamber from the nozzle. The estimation unit estimates the first ink amount sucked by the suction pump based on, for example, the time from when the suction operation is performed until the detection device detects that the pressure in the storage chamber is equal to or lower than the first pressure. As described above, the amount of ink stored in the storage chamber varies depending on the state of the pressure-sensitive membrane, so the determination unit can determine the state of the pressure-sensitive membrane based on the first ink amount estimated by the estimation unit. If the determination unit determines that the pressure-sensitive membrane is not normal, there is a risk that excessive ink will be supplied to the storage chamber, so by replacing the pressure-sensitive membrane in advance, it is possible to prevent ink from leaking from the nozzles of the ink head.

The present invention provides an inkjet printer that can prevent ink from leaking from the nozzles of the ink head by determining the state of the pressure-sensitive film.

1 is a perspective view of a printer according to an embodiment; 1 is a front view of a main part of a printer according to an embodiment. FIG. 2 is a schematic diagram illustrating a portion of an ink supply system according to an embodiment. FIG. 2 is a bottom view of a carriage according to an embodiment. FIG. 2 is a vertical cross-sectional view showing the configuration of a liquid feed pump according to one embodiment. FIG. 2 is a plan cross-sectional view of a damper and a detection device according to an embodiment, illustrating a state in which the pressure in the reservoir is equal to or lower than a first pressure. FIG. 2 is a plan cross-sectional view of a damper and a detection device according to an embodiment, illustrating a state in which the pressure in the reservoir is greater than a first pressure. FIG. 2 is a diagram showing the peripheral configuration of a capping device according to an embodiment, and is a front view showing a state in which a cap is removed from an ink head. FIG. 2 is a diagram showing the peripheral configuration of a capping device according to an embodiment, and is a front view showing a state in which a cap is attached to an ink head. FIG. 2 is a block diagram of a control system of the printer according to the embodiment. 1 is a flowchart illustrating a procedure for determining a state of a pressure-sensitive membrane according to an embodiment. 10 is a flowchart illustrating a procedure for correcting the suction capacity of a suction pump according to an embodiment. 10 is a flowchart illustrating a procedure for correcting the liquid delivery capacity of a liquid delivery pump according to an embodiment.

An inkjet printer 10 (hereinafter referred to as printer 10) according to one embodiment will be described below with reference to the drawings. The embodiment described here is, of course, not intended to limit the present invention in any particular way. In addition, the same reference numerals are used for components and parts that perform the same function, and duplicate descriptions will be omitted or simplified as appropriate.

In the following description, left, right, top, and bottom refer to the left, right, top, and bottom as seen by a user standing in front of the printer 10. The direction from the printer 10 that is closer to the user is the front, and the direction that is farther away is the rear. The symbols F, Rr, L, R, U, and D in the drawings represent the front, rear, left, right, top, and bottom, respectively. The symbol Y in the drawings represents the main scanning direction. In this embodiment, the main scanning direction Y is the left-right direction. The symbol X in the drawings represents the sub-scanning direction. The sub-scanning direction X is a direction that intersects with the main scanning direction Y (for example, a direction that intersects perpendicularly in a plan view). In this embodiment, the sub-scanning direction X is the front-rear direction. However, the above directions are merely defined for convenience and should not be interpreted in a restrictive manner.

As shown in FIG. 1, the printer 10 prints on a recording medium 12. The recording medium 12 is formed, for example, in a long length and wound into a roll before use. The recording medium 12 may also be in the form of a sheet that is wound into a roll and cut to a predetermined length. The recording medium 12 is, for example, recording paper. However, the recording medium 12 is not limited to recording paper. For example, the recording medium 12 includes a sheet formed from a resin material such as polyvinyl chloride (PVC) or polyester, a sealing material consisting of a backing paper and a release paper that is laminated on the backing paper and coated with an adhesive, and the like.

As shown in FIG. 1, the printer 10 includes a base member 40, a main body case 50, a right leg 16R, a left leg 16L, an ink head unit 20 (see FIG. 2), and a control device 100 (see FIG. 2). The base member 40 extends in the main scanning direction Y. The base member 40 includes a platen 15. The platen 15 extends in the main scanning direction Y. The right leg 16R and the left leg 16L are attached to the lower part of the base member 40. The right leg 16R and the left leg 16L support the base member 40.

As shown in FIG. 2, the ink head unit 20 is provided on the base member 40. The ink head unit 20 is disposed inside the main body case 50. The ink head unit 20 is disposed above the platen 15. The ink head unit 20 includes a carriage 22, an ink head 21 (described later), and a damper 80.

As shown in FIG. 2, the printer 10 has a guide rail 13 provided on a base member 40. The guide rail 13 extends in the main scanning direction Y. A carriage 22 of the ink head unit 20 is engaged with the guide rail 13. The carriage 22 reciprocates along the guide rail 13 in the main scanning direction Y by a carriage movement mechanism 8. The carriage movement mechanism 8 has a left pulley 19a arranged on the left end side of the guide rail 13 and a pulley 19b arranged on the right end side of the guide rail 13. A carriage motor 8a is connected to the pulley 19b. The carriage motor 8a may be connected to the pulley 19a. The pulley 19b is driven by the carriage motor 8a. An endless belt 16 is wound around the pulleys 19a and 19b. The carriage 22 is fixed to the belt 16. When pulleys 19a and 19b rotate and belt 16 runs, carriage 22 moves in the main scanning direction Y. In this way, carriage 22 is configured to be able to move in main scanning direction Y along guide rail 13.

As shown in FIG. 2, the platen 15 is provided in the center of the base member 40. The platen 15 is disposed between the left front cover 54L and the right front cover 54R of the main case 50. The recording medium 12 is placed on the platen 15. The platen 15 extends in the main scanning direction Y. The platen 15 is provided with a plurality of grit rollers 17. The grit rollers 17 are disposed in positions facing pinch rollers (not shown) provided on the base member 40. The grit rollers 17 are connected to a feed motor 17a. The grit rollers 17 are driven to rotate by the feed motor 17a. When the grit roller 17 rotates with the recording medium 12 sandwiched between the grit roller 17 and the pinch roller, the recording medium 12 is transported in the sub-scanning direction X (see FIG. 1).

As shown in FIG. 2, the main body case 50 houses a plurality of ink cartridges 25. The ink cartridges 25 are containers that seal and store ink. In this embodiment, eight ink cartridges 25 are housed in the main body case 50. The ink cartridges 25 are detachably connected to an upstream end 62 (see FIG. 3) of an ink path 60 (see FIG. 3) described later. When the ink cartridge 25 is attached to the upstream end 62, the ink cartridge 25 is located above a damper 80 described later. The ink cartridges 25 store any of the following inks: process color inks such as cyan ink, magenta ink, yellow ink, light cyan ink, light magenta ink, and black ink, and special color inks such as white ink, metallic ink, and clear ink.

As shown in FIG. 2, the printer 10 includes an ink supply system 55. In addition to the ink cartridge 25, the ink supply system 55 includes an ink head, an ink path 60 (see FIG. 3), a liquid feed pump 68, a damper 80, and a detection device 90 (see FIG. 3). The ink head 21 and the damper 80 are mounted on the carriage 22 and move back and forth in the main scanning direction Y. On the other hand, the ink cartridge 25 is not mounted on the carriage 22 and does not move back and forth in the main scanning direction Y. Therefore, most of the ink path 60 (at least half of its total length) is arranged to extend in the main scanning direction Y so that the ink path 60 will not be damaged even if the carriage 22 moves in the main scanning direction Y. The ink path 60 is covered with a cable protection and guide device 46.

As shown in FIG. 4, the ink head 21 is formed in a shape in which the length in the sub-scanning direction X (front-back direction) is longer than the length in the main scanning direction Y (left-right direction). The ink heads 21 are formed in the same shape and size. The ink head 21 has a number of nozzles 23 aligned in the sub-scanning direction X, and a nozzle surface 24 on which the nozzles 23 are formed. A negative pressure (pressure lower than atmospheric pressure) is set inside the nozzles 23. Note that since the nozzles 23 are very small, the multiple nozzles 23 are represented by straight lines in FIG. 4. The ink head 21 is housed in the carriage 22 so that the nozzle surfaces 24 are exposed to the outside.

As shown in FIG. 3, the ink cartridge 25 and the ink head 21 communicate with each other through the ink path 60. The ink path 60 has an upstream end 62, a downstream end 63, and a middle portion 65. The upstream end 62 is detachably connected to the ink outlet of the ink cartridge 25. The downstream end 63 is connected to the ink head 21. The middle portion 65 is located between the upstream end 62 and the downstream end 63. The ink path 60 forms a flow path that guides ink from the ink cartridge 25 to the ink head 21. The ink path 60 is flexible and elastic, and is configured to be elastically deformable. The configuration of the ink path 60 is not particularly limited, but in this embodiment, it is a tube made of resin that is easily deformed. However, it may be made of a material other than a tube. A part of the ink path 60 may be configured by a tube.

As shown in FIG. 3, the midway section 65 includes tubes 65A, 65B, and 65C. Tube 65A connects the ink cartridge 25 to the liquid feed pump 68. Tube 65B connects the liquid feed pump 68 to the damper 80. Tube 65C connects the damper 80 to the ink head 21. The upstream end 62 is provided on tube 65A. The downstream end 63 is provided on tube 65C.

As shown in FIG. 3, the liquid delivery pump 68 is disposed in the middle section 65. The liquid delivery pump 68 is disposed between the ink cartridge 25 and the damper 80. The liquid delivery pump 68 is configured to be able to open and close the middle section 65. The liquid delivery pump 68 is configured to be able to deliver ink from the ink cartridge 25 to the ink head 21. The liquid delivery pump 68 is driven when the detection device 90 detects that the pressure in the storage chamber 81 of the damper 80 is equal to or lower than the first pressure (for example, the absolute pressure in the storage chamber 81 is equal to or lower than the first pressure). When a predetermined amount of ink is supplied to the storage chamber 81 by the liquid delivery pump 68, the pressure in the storage chamber 81 becomes higher than the first pressure (for example, the absolute pressure in the storage chamber 81 becomes higher than the first pressure). The first pressure is, for example, about -1.5 kPa to about -0.1 kPa (preferably -0.9 kPa to -0.7 kPa).

Figure 5 is a vertical cross-sectional view showing the configuration of the liquid delivery pump 68. As shown in Figure 5, the liquid delivery pump 68 is a tube pump. The tube pump includes a case 71 having a wall formed in an arc shape, a tube 72 arranged in the case 71, a pressing body 73 capable of pressing a part of the tube 72, a rotating disk 74 for supporting the pressing body 73 and moving the pressing body 73 in the case 71, and a motor 75 for rotating the rotating disk 74. The tube 72 is formed so that ink flows through it and can be elastically deformed. One end 72A of the tube 72 is connected to the tube 65A (see Figure 3). The other end 72B of the tube 72 is connected to the tube 65B (see Figure 3). The pressing body 73 is fixed on the rotating disk 74 so that it moves along the tube 72 when the rotating disk 74 rotates. The pressing body 73 moves while pressing a part of the tube 72 as the rotating disk 74 rotates in the direction of the arrow R1 in Figure 5. This causes the ink in the tube 72 to move while closing the tube 72. Also, the pressing body 73 moves away from the tube 72 as the rotating disk 74 rotates in the direction of the arrow R2 in FIG. 5, thereby opening the tube 72. The pressing body 73 moves away from the tube 72 to open the midsection 65, and the pressing body 73 presses the tube 72 to close the midsection 65. The motor 75 is controlled by the control device 100.

As shown in FIG. 3, the damper 80 is disposed in the midway portion 65. The damper 80 is disposed between the liquid delivery pump 68 and the ink head 21. The damper 80 has a storage chamber 81 in which ink is temporarily stored. Ink supplied from the ink cartridge 25 is temporarily stored in the storage chamber 81. The damper 80 is in communication with the ink head 21. The damper 80 is provided, for example, on the top of the ink head 21.

Figure 6 is a cross-sectional view showing the configuration of the damper 80 and the detection device 90. The damper 80 reduces pressure fluctuations in the ink to stabilize the ink ejection operation from the ink head 21. In this embodiment, as shown in Figure 6, the damper 80 includes a case body 82 and a pressure-sensitive membrane 83.

As shown in FIG. 6, the case body 82 has a hollow structure with an opening 82A formed on one surface (the surface on the right side in FIG. 6). The case body 82 is typically formed from a resin material. The pressure-sensitive membrane 83 is attached to the outer wall surface of the case body 82 so as to cover the opening 82A. The storage chamber 81 is a space surrounded by the case body 82 and the pressure-sensitive membrane 83. The pressure-sensitive membrane 83 is made of, for example, a flexible resin film. As shown in FIG. 6 and FIG. 7, the pressure-sensitive membrane 83 is configured to bend and deform in response to the amount of ink stored in the storage chamber 81 and the pressure in the storage chamber 81. The pressure-sensitive membrane 83 is flexibly deformable inward and outward of the storage chamber 81. The pressure-sensitive membrane 83 is attached to the case body 82 with a tension that allows it to bend inward and outward of the storage chamber 81, respectively.

As shown in FIG. 6, a spring 85 is provided in the storage chamber 81. The spring 85 is arranged in the storage chamber 81 in a compressed state, and applies an elastic force toward the pressure-sensitive membrane 83. Here, the spring 85 is in contact with the surface of the pressure-sensitive membrane 83 facing the storage chamber 81. The type of spring 85 is not particularly limited. In this embodiment, the spring 85 is a coil spring. The pressure-sensitive membrane 83 is provided with a pressing body 86. The pressing body 86 is supported by the spring 85. The pressing body 86 can move in and out of the storage chamber 81 in response to the flexural deformation of the pressure-sensitive membrane 83.

As shown in FIG. 3, the detection device 90 is disposed to the side of the damper 80. The detection device 90 detects the pressure in the storage chamber 81 of the damper 80 (in other words, the amount of ink flowing into the storage chamber 81). The liquid delivery pump 68 is controlled based on the pressure in the storage chamber 81.

6, the detection device 90 includes a lever 84. The lever 84 is provided on the case body 82 so as to be in contact with the pressing body 86. In this embodiment, a support spring 87 is provided on the case body 82, and the lever 84 is supported by the support spring 87. The shape of the lever 84 is not particularly limited. Here, the lever 84 is formed in a substantially U-shape. In detail, the lever 84 has a contact portion 84A extending in the front-rear direction to the right of the pressing body 86, a support portion 84B extending leftward from the rear end of the contact portion 84A, and a detected portion 84C extending leftward from the front end of the contact portion 84A. The pressing body 86 can contact the contact portion 84A. The support portion 84B is supported by the support spring 87. The detected portion 84C is a portion detected by the detection unit 95 described later. When the pressure-sensitive membrane 83 bends toward the inside of the storage chamber 81 (i.e., when the ink in the storage chamber 81 decreases and the pressure decreases), the lever 84 moves toward the storage chamber 81. As shown in FIG. 7, when the pressure-sensitive membrane 83 bends toward the outside of the storage chamber 81 (i.e., when the ink in the storage chamber 81 increases and the pressure increases), the lever 84 moves away from the storage chamber 81.

6, the detection device 90 includes a detection unit 95. The detection unit 95 includes a light-emitting unit 91 having a light-emitting element that emits light such as infrared light, a light-receiving unit 92 having a light-receiving element that detects the light emitted from the light-emitting unit 91, and a detection area 93 provided between the light-emitting unit 91 and the light-receiving unit 92. The light-emitting unit 91 and the light-receiving unit 92 are arranged to face each other. The detection device 90 can detect whether the pressure in the storage chamber 81 is equal to or lower than the first pressure based on the position change of the lever 84. As shown in FIG. 7, as the pressure in the storage chamber 81 becomes greater than the first pressure, the pressure-sensitive membrane 83 bends outward from the storage chamber 81. At this time, the lever 84 is pushed outward from the storage chamber 81 by the pressing body 86, and the lever 84 rotates around the support spring 87. Then, when the pressure in the storage chamber 81 becomes greater than the first pressure, the detectable portion 84C of the lever 84 moves to a position outside the detection area 93 of the detection device 90. When the detectable portion 84C of the lever 84 moves out of the detection area 93 (i.e., when the detectable portion 84C is not located in the detection area 93), the detection device 90 detects that the pressure in the storage chamber 81 is greater than the first pressure. On the other hand, when the detectable portion 84C of the lever 84 blocks the detection area 93 (i.e., when the detectable portion 84C is located in the detection area 93), the detection device 90 detects that the pressure in the storage chamber 81 is equal to or less than the first pressure.

2, the printer 10 includes a capping device 41. The capping device 41 is provided in the main body case 50. The capping device 41 is disposed to the right of the platen 15. As shown in FIG. 8, the capping device 41 includes eight caps 42 that can be attached to and detached from the ink head 21, a cap moving mechanism 43, and a suction pump 44. The caps 42 and the cap moving mechanism 43 are disposed at a home position HP located at the right end of the guide rail 13 (see FIG. 2). Here, the home position HP is a position where the carriage 22 and the ink head 21 wait when waiting for printing, i.e., when printing is not being performed. However, the position of the home position HP is not particularly limited, and may be the left end of the guide rail 13. Note that in the examples shown in FIG. 8 and FIG. 9, the damper 80 is omitted.

The caps 42 are members that prevent ink adhering to the nozzles 23 (see FIG. 4) of the ink head 21 from hardening and clogging the nozzles 23. The caps 42 are lined up in the main scanning direction Y. As shown in FIG. 9, when waiting to print, the caps 42 are attached to the ink heads 21 respectively to cover the nozzle surfaces 24. That is, when the carriage 22 moves to the home position HP, the caps 42 are attached to the ink heads 21 respectively.

The cap moving mechanism 43 supports the cap 42. The cap moving mechanism 43 is a mechanism that moves the cap 42 so that it can be attached and detached to and from the ink head 21. In this embodiment, the cap moving mechanism 43 moves the cap 42 in the vertical direction. The configuration of the cap moving mechanism 43 is not particularly limited, but for example, it is provided with a drive motor 43A. By driving the drive motor 43A, the cap moving mechanism 43 moves the cap 42 in the vertical direction. The cap moving mechanism 43 moves the cap 42 upward and downward to the cap position CP (see FIG. 9) by moving the cap 42 upward. Here, the cap position CP is a position where the cap 42 covers the nozzle surface 24 of the ink head 21. As a result, the cap 42 is attached to each of the ink heads 21. When the caps 42 are attached to each of the ink heads 21, a sealed space 48 (see FIG. 9) is formed between the cap 42 and the nozzle surface 24. When printing starts, the cap moving mechanism 43 moves the cap 42 downward, thereby moving the cap 42 from the cap position CP (see FIG. 9) to the separated position DP (see FIG. 8). Here, the separated position DP is a position where the cap 42 is separated from the nozzle surface 24. As a result, the cap 42 is removed from each ink head 21.

9, the capping device 41 includes two suction pumps 44. When the cap 42 is attached to the ink head 21, the suction pump 44 performs a suction operation to suck the fluid (e.g., ink) in the sealed space 48 and eject the ink from the nozzle 23 (see FIG. 4). By driving the suction pump 44, the pressure in the sealed space 48 becomes lower than atmospheric pressure (i.e., negative pressure). As a result, the ink is forcibly discharged from the nozzle 23 of the ink head 21. The suction ports of the suction pumps 44 are connected to the four caps 42 via flexible tubes 45. The discharge ports of the suction pumps 44 are connected to the waste liquid tank 49. The fluid in the sealed space 48 sucked by the suction pump 44 is stored in the waste liquid tank 49. The suction pumps 44 are controlled by the control device 100 (see FIG. 2). The two suction pumps 44 are controlled independently of each other.

As shown in FIG. 1, an operation panel 18 is provided behind the right front cover 54R of the main body case 50. The operation panel 18 is provided with a display unit (not shown) that displays the printer status, and input keys (not shown) that are operated by the user. The operation panel 18 is connected to a control device 100 (see FIG. 2) that controls various operations of the printer 10.

As shown in FIG. 10, the overall operation of the printer 10 is controlled by the control device 100. The configuration of the control device 100 is not particularly limited. The control device 100 is, for example, a microcomputer. The hardware configuration of the microcomputer is not particularly limited, but for example, the microcomputer includes an interface (I/F) that receives print data from an external device such as a host computer, a central processing unit (CPU) that executes instructions of a control program, a read only memory (ROM) that stores the program executed by the CPU, a random access memory (RAM) used as a working area for expanding the program, and a storage device such as a memory that stores programs and various data. As shown in FIG. 2, the control device 100 is provided inside the main body case 50. However, the control device 100 does not have to be provided inside the main body case 50. For example, the control device 100 may be a computer or the like installed outside the printer 10. In this case, the control device 100 is connected to the printer 10 so as to be able to communicate with it via wire or wirelessly.

As shown in FIG. 10, the control device 100 is communicatively connected to the ink head 21, carriage motor 8a, feed motor 17a, liquid delivery pump 68, detection device 90, drive motor 43A, and suction pump 44. The control device 100 controls the ink head 21, carriage motor 8a, feed motor 17a, liquid delivery pump 68, drive motor 43A, and suction pump 44.

As shown in FIG. 10, the control device 100 includes a memory unit 102, a first ink delivery unit 104, a first suction control unit 106, an estimation unit 108, a judgment unit 110, a notification unit 112, a first flushing control unit 114, a second ink delivery unit 116, a second suction control unit 118, a second flushing control unit 120, a first correction unit 122, and a second correction unit 124. The functions of each unit of the control device 100 are realized by a program. For example, the program is written from a PC via a LAN to a ROM mounted on a board inside the printer 10, or written from a PC to an FPGA mounted on a board inside the printer 10 using a dedicated writing tool. The program is downloaded to the PC via the Internet, for example. The functions of each unit of the control device 100 may be realized by a processor and/or a circuit. The specific functions of each unit will be described later.

Next, a method for determining the state of the pressure-sensitive film 83 of the damper 80 will be described. FIG. 11 is a flowchart showing the procedure for determining the state of the pressure-sensitive film 83 of the damper 80 before printing starts or during cleaning. Here, since the pressure-sensitive film 83 is used in contact with ink, the pressure-sensitive film 83 may shrink over time. If the pressure-sensitive film 83 shrinks, when a predetermined amount of ink is sent from the liquid sending pump 68 to the storage chamber 81, the pressure-sensitive film 83 may not bend sufficiently to the outside of the storage chamber 81, and the detected portion 84C of the lever 84 of the detection device 90 may not come out of the detection area 93. In this case, since more ink is sent from the liquid sending pump 68 to the storage chamber 81, the pressure in the storage chamber 81 may rise above a predetermined set value, and there is a risk that ink may leak from the nozzle 23 of the ink head 21. In this embodiment, the state of the pressure-sensitive film 83 is determined in advance to prevent ink from leaking from the nozzle 23.

First, in step S110, ink is ejected from the nozzle 23 of the ink head 21 until the pressure in the storage chamber 81 becomes equal to or lower than the first pressure. Here, ink may be ejected from the nozzle 23 by a flushing operation, or ink may be ejected from the nozzle 23 by a suction operation. For example, the first flushing control unit 114 executes a flushing operation that ejects ink from the nozzle 23 until the detection device 90 detects that the pressure in the storage chamber 81 is equal to or lower than the first pressure. The flushing operation is performed, for example, with the cap 42 attached to the ink head 21. Note that when the flushing operation and the suction operation are performed, the intermediate portion 65 is closed by the liquid delivery pump 68. That is, ink is not supplied from the ink cartridge 25.

In step S120, the first ink delivery unit 104 delivers ink to the storage chamber 81 at a predetermined pressure (constant pressure). For example, the first ink delivery unit 104 controls the delivery pump 68 to open the midway portion 65, and delivers ink to the storage chamber 81 at a predetermined pressure, which is the head pressure between the ink cartridge 25 and the damper 80. That is, with the midway portion 65 open and the ink cartridge 25 and the storage chamber 81 in communication, ink is delivered to the storage chamber 81 by the ink's own weight. After a certain time has elapsed since the midway portion 65 was opened (i.e., from the start of ink supply), the first ink delivery unit 104 controls the delivery pump 68 to close the midway portion 65.

In step S130, the determination unit 110 determines whether the pressure in the storage chamber 81 is greater than the first pressure after the first ink delivery unit 104 delivers ink to the storage chamber 81. More specifically, the determination unit 110 determines that the pressure in the storage chamber 81 is greater than the first pressure when the detection target 84C of the lever 84 of the detection device 90 is out of the detection area 93, and determines that the pressure in the storage chamber 81 is equal to or less than the first pressure when the detection target 84C of the lever 84 of the detection device 90 blocks the detection area 93. If the pressure in the storage chamber 81 is greater than the first pressure, the process proceeds to step S140. On the other hand, if the pressure in the storage chamber 81 is equal to or less than the first pressure, the process proceeds to step S170.

In step S140, after the first ink delivery unit 104 delivers ink to the storage chamber 81, the first suction control unit 106 drives the suction pump 44 to perform a suction operation to suck the fluid in the sealed space 48. The first suction control unit 106 performs the suction operation until the detection device 90 detects that the pressure in the storage chamber 81 is equal to or lower than the first pressure. The first suction control unit 106 controls the drive motor 43A and the suction pump 44.

In step S150, the estimation unit 108 estimates the first ink amount sucked by the suction pump 44 until the detection device 90 detects that the pressure in the storage chamber 81 is equal to or lower than the first pressure. The estimation unit 108 estimates the first ink amount based on, for example, the time from the start to the end of the suction operation (i.e., when it is detected that the pressure in the storage chamber 81 is equal to or lower than the first pressure). The first ink amount is stored in the memory unit 102. The estimation unit 108 may estimate the first ink amount from the number of revolutions of the suction pump 44 from the start to the end of the suction operation.

In step S160, the determination unit 110 determines the state of the pressure-sensitive film 83 based on the first ink amount estimated by the estimation unit 108. If the first ink amount is less than the predetermined ink amount, the determination unit 110 determines that the pressure-sensitive film 83 has contracted. If the first ink amount is the same as the predetermined ink amount, the determination unit 110 determines that the pressure-sensitive film 83 has not contracted. The predetermined ink amount is stored in the memory unit 102. If the first ink amount is less than the predetermined ink amount, the process proceeds to step S170. On the other hand, if the first ink amount is the same as the predetermined ink amount, the pressure-sensitive film 83 is normal and the process ends.

In step S170, the notification unit 112 notifies the user that a malfunction has occurred in the pressure-sensitive membrane 83. The notification method by the notification unit 112 is not particularly limited, and examples include notification by visual display, audio, etc. In this embodiment, the notification unit 112 notifies the user visually through the operation panel 18. In addition to or instead of notifying the user of the malfunction, the first suction control unit 106 may further perform a suction operation to set the pressure in the storage chamber 81 to a second pressure that is lower than the first pressure. This makes it possible to forcibly stretch the pressure-sensitive membrane 83 and improve the condition of the pressure-sensitive membrane 83. The second pressure is, for example, approximately -90 kPa to approximately -80 kPa.

Next, a method for correcting the suction capacity of the suction pump 44 will be described. FIG. 12 is a flowchart showing the procedure for correcting the suction capacity of the suction pump 44. By correcting the suction capacity of the suction pump 44 before determining the state of the pressure-sensitive film 83 described above, the estimation unit 108 can estimate the first ink amount more accurately. Note that it is optional whether or not to correct the suction capacity of the suction pump 44.

First, in step S210, ink is ejected from the nozzle 23 of the ink head 21 until the pressure in the storage chamber 81 becomes equal to or lower than the first pressure. Here, ink is ejected from the nozzle 23 by a flushing operation. For example, the first flushing control unit 114 executes a flushing operation that ejects ink from the nozzle 23 until the detection device 90 detects that the pressure in the storage chamber 81 is equal to or lower than the first pressure. When the first flushing control unit 114 detects that the pressure in the storage chamber 81 is equal to or lower than the first pressure, it stops the flushing operation.

In step S220, the second ink delivery unit 116 controls the liquid delivery pump 68 to deliver the second ink amount to the storage chamber 81. The second ink delivery unit 116 controls the motor 75 of the liquid delivery pump 68 to rotate the rotating disk 74 a predetermined number of rotations A(r), thereby delivering the second ink amount to the storage chamber 81. After delivery, the intermediate portion 65 is closed by the liquid delivery pump 68. The second ink amount is stored in the memory unit 102.

In step S230, after the second ink supply unit 116 supplies the second ink amount to the storage chamber 81, the second suction control unit 118 drives the suction pump 44 to perform a suction operation to suck the fluid in the sealed space 48. The second suction control unit 118 performs the suction operation until the detection device 90 detects that the pressure in the storage chamber 81 is equal to or lower than the first pressure. The second suction control unit 118 controls the drive motor 43A and the suction pump 44. When the second suction control unit 118 detects that the pressure in the storage chamber 81 is equal to or lower than the first pressure, it stops the suction operation. The second suction control unit 118 counts the number of rotations B(r) of the suction pump 44 during the suction operation.

In step S240, the estimation unit 108 estimates the first ink amount that has been sucked by the suction pump 44 until the detection device 90 detects that the pressure in the storage chamber 81 is equal to or lower than the first pressure. The estimation unit 108 estimates the first ink amount based on, for example, the time from the start to the end of the suction operation. The first ink amount is stored in the memory unit 102.

In step S250, the first correction unit 122 corrects the suction capacity of the suction pump 44 based on the first ink amount estimated by the estimation unit 108 and the second ink amount delivered by the second ink delivery unit 116. That is, when the delivery capacity of the delivery pump 68 is PP (ml/r), the first correction unit 122 calculates the suction capacity NP (ml/r) of the suction pump 44 by the following formula (1).

・・・（１）

...(1)

Next, a method for correcting the liquid delivery capacity of the liquid delivery pump 68 will be described. FIG. 13 is a flow chart showing the procedure for correcting the liquid delivery capacity of the liquid delivery pump 68. By correcting the liquid delivery capacity of the liquid delivery pump 68 before correcting the suction capacity of the suction pump 44 described above, the suction capacity of the suction pump can be corrected more accurately. Note that it is optional whether or not to correct the liquid delivery capacity of the liquid delivery pump 68.

First, in step S310, ink is ejected from the nozzle 23 of the ink head 21 until the pressure in the storage chamber 81 becomes equal to or lower than the first pressure. Here, ink is ejected from the nozzle 23 by a flushing operation. For example, the first flushing control unit 114 executes a flushing operation that ejects ink from the nozzle 23 until the detection device 90 detects that the pressure in the storage chamber 81 is equal to or lower than the first pressure. When the first flushing control unit 114 detects that the pressure in the storage chamber 81 is equal to or lower than the first pressure, it stops the flushing operation.

In step S320, the second ink delivery unit 116 controls the liquid delivery pump 68 to deliver the second ink amount to the storage chamber 81. The second ink delivery unit 116 controls the motor 75 of the liquid delivery pump 68 to rotate the rotating disk 74 a predetermined number of rotations A(r), thereby delivering the second ink amount to the storage chamber 81. After delivery, the intermediate portion 65 is closed by the liquid delivery pump 68. The second ink amount is stored in the memory unit 102.

In step S330, after the second ink volume is sent to the storage chamber 81 by the second ink sending unit 116, the second flushing control unit 120 executes the flushing operation until the detection device 90 detects that the pressure in the storage chamber 81 is equal to or lower than the first pressure. When the second flushing control unit 120 detects that the pressure in the storage chamber 81 is equal to or lower than the first pressure, the second flushing control unit 120 stops the flushing operation. The second flushing control unit 120 counts the number of flushing shots FL (shots) in the flushing operation. The third ink volume ejected by the flushing operation of the second flushing control unit 120 is stored in the memory unit 102.

In step S340, the second correction unit 124 corrects the liquid delivery capacity of the liquid delivery pump 68 based on the amount of the third ink ejected by the flushing operation by the second flushing control unit 120 and the amount of the second ink delivered by the second ink delivery unit 116. That is, when the ejection volume per flushing shot is C (ml/shot), the second correction unit 124 calculates the liquid delivery capacity PP (ml/r) of the liquid delivery pump 68 by the following formula (2).

・・・（２）

... (2)

As described above, according to the printer 10 of this embodiment, the first ink delivery unit 104 delivers ink to the storage chamber 81 at a predetermined pressure. Here, when the pressure-sensitive membrane 83 is normal, the pressure-sensitive membrane 83 bends outwardly significantly when ink is delivered to the storage chamber 81 at a predetermined pressure. Therefore, when ink is delivered to the storage chamber 81 and the lever 84 is removed from the detection area 93, a relatively large amount of ink is stored in the storage chamber 81. On the other hand, when the pressure-sensitive membrane 83 is contracted, the pressure-sensitive membrane 83 does not bend outwardly much even when ink is delivered to the storage chamber 81 at a predetermined pressure. Therefore, when ink is delivered to the storage chamber 81 and the lever 84 is removed from the detection area 93, a relatively small amount of ink is stored in the storage chamber 81. Then, the first suction control unit 106 performs a suction operation to discharge the ink in the storage chamber 81 from the nozzle 23. The estimation unit 108 estimates the first ink amount sucked by the suction pump 44 based on, for example, the time from when the suction operation is performed until the detection device 90 detects that the pressure in the storage chamber 81 is equal to or lower than the first pressure. As described above, the amount of ink stored in the storage chamber 81 varies depending on the state of the pressure-sensitive membrane 83, so the determination unit 110 can determine the state of the pressure-sensitive membrane 83 based on the first ink amount estimated by the estimation unit 108. If the determination unit 110 determines that the pressure-sensitive membrane 83 is not normal, there is a risk that excessive ink will be supplied to the storage chamber 81. Therefore, by replacing the pressure-sensitive membrane 83 in advance, it is possible to prevent ink from leaking from the nozzle 23 of the ink head 21.

According to the printer 10 of this embodiment, when the ink cartridge 25 is attached to the upstream end 62, the ink cartridge 25 is located above the damper 80, the liquid delivery pump 68 is configured to be able to open and close the midway portion 65, and the first ink delivery unit 104 controls the liquid delivery pump 68 to open the midway portion 65 and delivers ink to the storage chamber 81 at a predetermined pressure, which is the head pressure between the ink cartridge 25 and the damper 80. This allows ink to be delivered appropriately to the storage chamber 81 while preventing excessive ink from being delivered to the storage chamber 81.

According to the printer 10 of this embodiment, if the first ink amount is less than a preset predetermined ink amount, the judgment unit 110 judges that the pressure-sensitive film 83 is contracted. If the pressure-sensitive film 83 is contracted, the first ink amount stored in the storage chamber 81 becomes less than the predetermined ink amount, and the judgment unit 110 can judge that the pressure-sensitive film 83 is contracted.

According to the printer 10 of this embodiment, when the determination unit 110 determines that the pressure-sensitive membrane 83 is contracted, the first suction control unit 106 may further perform a suction operation to set the pressure in the storage chamber 81 to a second pressure that is lower than the first pressure. This increases the negative pressure in the storage chamber 81, forcibly stretching the contracted pressure-sensitive membrane 83, and improves the condition of the pressure-sensitive membrane 83.

In the printer 10 of this embodiment, the control device 100 includes a notification unit 112 that notifies the operator that a malfunction has occurred in the pressure-sensitive membrane 83 when the determination unit 110 determines that the pressure-sensitive membrane 83 has contracted. This allows the operator to recognize that the pressure-sensitive membrane 83 has contracted, and therefore allows the operator to replace the damper 80 itself or the pressure-sensitive membrane 83.

According to the printer 10 of this embodiment, the control device 100 includes a first flushing control unit 114 that executes a flushing operation to eject ink from the nozzle 23 until the detection device 90 detects that the pressure in the storage chamber 81 is equal to or lower than the first pressure, a second ink delivery unit 116 that controls the liquid delivery pump 68 to deliver ink by the second ink amount to the storage chamber 81, a second suction control unit 118 that executes a suction operation after the second ink delivery unit 116 delivers the second ink amount to the storage chamber 81, and a first correction unit 122 that corrects the suction capacity of the suction pump 44 based on the first ink amount estimated by the estimation unit 108 and the second ink amount delivered by the second ink delivery unit 116. In this way, by correcting the suction capacity of the suction pump 44 in advance by the first correction unit 122, the estimation unit 108 can more accurately estimate the amount of ink suctioned by the suction pump 44, and can more accurately determine the state of the pressure-sensitive membrane 83.

According to the printer 10 of this embodiment, the control device 100 includes a second flushing control unit 120 that executes a flushing operation until the detection device 90 detects that the pressure in the storage chamber 81 is equal to or lower than the first pressure after the second ink supply unit 116 supplies the second ink amount to the storage chamber 81, and a second correction unit 124 that corrects the liquid supply capacity of the liquid supply pump 68 based on the third ink amount ejected by the second flushing control unit 120 and the second ink amount sent by the second ink supply unit 116. In this way, by correcting the liquid supply capacity of the liquid supply pump 68 in advance by the second correction unit 124, the amount of ink sent by the liquid supply pump 68 becomes more accurate, and the suction capacity of the suction pump 44 can be corrected more accurately.

The above describes a preferred embodiment of the present invention. However, the above embodiment is merely an example, and the present invention can be implemented in various other forms.

In the above-described embodiment, only the liquid delivery pump 68 is disposed in the midway portion 65, but this is not limited thereto. For example, a valve capable of opening and closing the midway portion 65 may be provided between the ink cartridge 25 and the liquid delivery pump 68.

In the above-described embodiment, ink is delivered to the storage chamber 81 by the head pressure between the ink cartridge 25 and the damper 80 as the predetermined pressure, but this is not limited to this. For example, a pump capable of delivering ink at a predetermined pressure (constant pressure) may be used as the delivery pump 68.

10. Printer (inkjet printer)
21 Ink head 23 Nozzle 25 Ink cartridge 42 Cap 44 Suction pump 62 Upstream end 65 Midway section 68 Liquid delivery pump 80 Damper 81 Storage chamber 83 Pressure-sensitive membrane 84 Lever 90 Detector 91 Light-emitting section 92 Light-receiving section 93 Detection area 100 Control device 104 First ink delivery section 106 First suction control section 108 Estimation section 110 Determination section 112 Notification section 114 First flushing control section 116 Second ink delivery section 118 Second suction control section 120 Second flushing control section 122 First correction section 124 Second correction section

Claims (7)

an ink head having a plurality of nozzles for ejecting ink onto a recording medium and a nozzle surface on which the plurality of nozzles are formed;
an ink path having an upstream end detachably connected to an ink cartridge that stores ink, a downstream end connected to the ink head, and a middle portion located between the upstream end and the downstream end;
a liquid feed pump disposed in the midway portion and capable of feeding ink from the ink cartridge toward the ink head;
a case body having an opening formed therein; a damper attached to the case body so as to cover the opening of the case body, the damper defining a storage chamber in which ink is temporarily stored together with the case body, and a pressure-sensitive membrane capable of deflecting and deforming on the inside and outside of the storage chamber, the damper being disposed in the midway portion so as to be located between the liquid feed pump and the ink head;
a lever that moves toward the storage chamber when the pressure-sensitive membrane bends inwardly of the storage chamber and moves away from the storage chamber when the pressure-sensitive membrane bends outwardly of the storage chamber; a light-emitting unit that emits a predetermined light; a light-receiving unit that receives the light emitted from the light-emitting unit; and a detection area provided between the light-emitting unit and the light-receiving unit, and a detection device that detects that the pressure in the storage chamber is equal to or lower than a first pressure when the lever blocks the detection area;
a cap that is detachably attached to the ink head and covers the nozzle surface when attached to the ink head and forms an enclosed space between the nozzle surface and the cap;
a suction pump that sucks fluid from within the sealed space;
a control device for controlling the ink head, the liquid feed pump, and the suction pump;
The control device includes:
a first ink delivery unit that delivers ink to the storage chamber at a predetermined pressure;
a first suction control unit that performs a suction operation of driving the suction pump to suck the fluid in the sealed space after the ink is sent to the storage chamber by the first ink sending unit;
an estimation unit that estimates a first amount of ink that has been sucked by the suction pump until the pressure in the storage chamber is detected to be equal to or lower than the first pressure by the detection device;
a determination unit that determines a state of the pressure-sensitive film based on the first ink amount estimated by the estimation unit. When the ink cartridge is attached to the upstream end, the ink cartridge is located above the damper,
The liquid feed pump is configured to be able to open and close the middle portion,
2. The inkjet printer according to claim 1, wherein the first ink delivery unit delivers ink to the storage chamber with a head pressure between the ink cartridge and the damper as the predetermined pressure while controlling the delivery pump to open the intermediate portion. The inkjet printer according to claim 1 or 2, wherein the determination unit determines that the pressure-sensitive film is contracted when the first ink amount is less than a preset predetermined ink amount. The inkjet printer according to claim 3, wherein the first suction control unit further executes the suction operation when the determination unit determines that the pressure-sensitive membrane is contracting, to set the pressure in the storage chamber to a second pressure that is lower than the first pressure. The inkjet printer according to claim 3 or 4, wherein the control device includes a notification unit that notifies the user that a malfunction has occurred in the pressure-sensitive membrane when the determination unit determines that the pressure-sensitive membrane is contracting. The control device includes:
a first flushing control unit that executes a flushing operation of ejecting ink from the nozzles until the pressure in the storage chamber is detected by the detection device to be equal to or lower than the first pressure;
a second ink delivery unit that controls the liquid delivery pump to deliver a second amount of ink to the storage chamber;
a second suction control unit that executes the suction operation after the second ink supply unit supplies the second amount of ink to the storage chamber;
6. The inkjet printer according to claim 1, further comprising: a first correction unit that corrects a suction capacity of the suction pump based on the first ink amount estimated by the estimation unit and the second ink amount delivered by the second ink delivery unit. The control device includes:
a second flushing control unit that executes the flushing operation until the detection device detects that the pressure in the storage chamber is equal to or lower than the first pressure after the second ink delivery unit delivers the second amount of ink to the storage chamber;
7. The inkjet printer according to claim 6, further comprising: a second correction unit that corrects the liquid delivery capacity of the liquid delivery pump based on a third ink amount ejected by the flushing operation by the second flushing control unit and the second ink amount delivered by the second ink delivery unit.

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