Liquid supply device, liquid discharge device

Abstract

To provide a liquid supply device and a liquid discharge device that can reduce the risk of liquid leakage. [Solution] A liquid supply device 14 connectable to a liquid discharge head 12 that discharges liquid from a nozzle 16, comprising: a supply channel 26 that supplies liquid from a liquid storage section 36 that contains liquid to the liquid discharge head 12; a bubble trap chamber 49 provided in the supply channel 26 that contains bubbles in the supply channel 26; a bubble discharge channel 50 connected to the bubble trap chamber 49 that discharges bubbles in the bubble trap chamber 49; and a valve unit 51 provided in the bubble discharge channel 50, wherein the valve unit 51 comprises a valve body that can open and close the bubble discharge channel 50, and an adjustment section that adjusts the opening pressure at which the valve body opens the bubble discharge channel 50.

Description

Technical Field

[0001] The present invention relates to a liquid supply device and a liquid ejection device including the liquid supply device.

Background Art

[0002] For example, as in Patent Document 1, there is an inkjet recording device which is an example of a liquid ejection device including a recording head which is an example of a liquid ejection head and an ink supply system which is an example of a liquid supply device. The inkjet recording device supplies liquid to the recording head through an ink flow path which is an example of a supply flow path from an ink tank which is an example of a liquid storage unit. The inkjet recording device includes a bubble recovery chamber which is an example of a bubble trap chamber and a bubble discharge unit.

[0003] The bubble recovery chamber is installed in the ink flow path. The ceiling hole of the bubble recovery chamber is blocked by a ball. The bubble discharge unit discharges bubbles from the bubble recovery chamber by opening the ceiling hole.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When controlling opening and closing from a valve, bubbles can be discharged from the bubble trap chamber at an arbitrary timing. However, for example, if the power supply of the device is turned off while the valve is open, the valve remains open, and thus there is a risk of liquid leakage.

Means for Solving the Problems

[0006] A liquid supply device that solves the above problems is a liquid supply device that can be connected to a liquid discharge head that discharges liquid from a nozzle, and comprises: a supply channel for supplying liquid from a liquid storage section that stores liquid to the liquid discharge head; a bubble trap chamber provided in the supply channel for storing bubbles in the supply channel; a bubble discharge channel connected to the bubble trap chamber for discharging bubbles in the bubble trap chamber; and a valve unit provided in the bubble discharge channel, wherein the valve unit comprises a valve body that can open and close the bubble discharge channel, and an adjustment section that adjusts the opening pressure at which the valve body opens the bubble discharge channel.

[0007] A liquid dispensing device that solves the above problems comprises the liquid dispensing head and the liquid supply device having the above configuration. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram of one embodiment of a liquid dispensing device. [Figure 2] Figure 2 is a schematic diagram of the valve unit in the discharge position. [Figure 3] Figure 3 is a schematic diagram of the valve unit in standby position. [Modes for carrying out the invention]

[0009] [Embodiment] Hereinafter, one embodiment of a liquid dispensing device will be described with reference to the drawings. The liquid dispensing device is an inkjet printer that prints by dispensing ink, which is an example of a liquid, onto a medium such as paper, cloth, vinyl, plastic parts, or metal parts.

[0010] <Liquid discharge device> As shown in Figure 1, the liquid dispensing device 11 may include a liquid dispensing head 12, a maintenance mechanism 13, and a liquid supply device 14.

[0011] The liquid dispensing head 12 has one or more nozzles 16. The liquid dispensing head 12 is capable of dispensing liquid from the nozzles 16. The liquid dispensing head 12 prints liquid from the nozzles 16 onto a medium (not shown).

[0012] <Maintenance Mechanism> The maintenance mechanism 13 may include a cap 18, a discharge channel 19, a drain valve 20, and a suction section 21. The discharge channel 19 may be connected to a waste liquid storage section 22. The waste liquid storage section 22 may be detachably attached to the liquid discharge device 11.

[0013] The cap 18 can contact the liquid dispensing head 12 to form a closed space through which the nozzle 16 opens. The cap 18 can receive the liquid discharged from the nozzle 16. The cap 18 may be movable between a capping position (not shown) and a separated position shown in Figure 1.

[0014] The capping position is the position in contact with the liquid dispensing head 12. When the cap 18 is in the capping position, the opening of the cap 18 is blocked by the liquid dispensing head 12, forming a closed space. The cap 18 in the capping position caps the liquid dispensing head 12.

[0015] The separated position is the position in which the liquid discharge head 12 is opened. When the cap 18 is in the separated position, it is separated from the liquid discharge head 12, and the opening of the cap 18 is opened. When the cap 18 is in the separated position, the space inside the cap 18 becomes an open space.

[0016] The discharge channel 19 has its upstream end connected to the space inside the cap 18 and its downstream end connected to the waste liquid storage section 22. The discharge channel 19 may be made of, for example, a tube that can deform to follow the movement of the cap 18. The discharge channel 19 is capable of discharging the liquid inside the cap 18 to the waste liquid storage section 22.

[0017] The drain valve 20 is installed in the discharge channel 19. The drain valve 20 can open and close the discharge channel 19. The suction part 21 may be provided in the discharge flow path 19. The suction part 21 is, for example, a tube pump. The suction part 21 can decompress the space in the cap 18 through the discharge flow path 19.

[0018] The maintenance mechanism 13 positions the cap 18 at the capping position and performs suction cleaning by decompressing the inside of the cap 18 with the drain valve 20 open to the suction part 21. The maintenance mechanism 13 discharges the liquid from the nozzle 16 by performing suction cleaning.

[0019] <Liquid supply device> The liquid supply device 14 may include a control unit 23. The control unit 23 comprehensively controls the driving of each mechanism in the liquid supply device 14 and controls various operations executed by the liquid supply device 14. The control unit 23 may control each main operation executed by the liquid discharge device 11.

[0020] The control unit 23 can be configured as a circuit including α: one or more processors that execute various processes according to a computer program, β: one or more dedicated hardware circuits that execute at least some of the various processes, or γ: a combination thereof. The hardware circuit is, for example, an application-specific integrated circuit. The processor includes a CPU and memories such as a RAM and a ROM, and the memories store program codes or instructions configured to cause the CPU to execute processes. The memory, that is, the computer-readable medium, includes any readable medium accessible by a general-purpose or dedicated computer.

[0021] The liquid supply device 14 may include a mounting part 25, a supply flow path 26, a branch flow path 27, and a parallel flow path 28. The liquid supply device 14 may include a resistance flow path 29 and a regulator 30. The liquid supply device 14 may include a liquid feeding part 31, a buffer 32, a degassing part 33, and a pressure regulating valve 34. [[ID=​The liquid supply device 14 can be connected to the liquid ejection head 12. The liquid supply device 14 supplies liquid from the liquid storage unit 36 mounted on the mounting portion 25 to the liquid ejection head 12. The liquid flows in the supply flow path 26 in the supply direction Ds.

[0023] The mounting portion 25 may be detachably mounted with the liquid storage unit 36. The liquid storage unit 36 stores liquid. The upstream end of the supply flow path 26 in the supply direction Ds is connected to the liquid storage unit 36. The upstream end of the supply flow path 26 may be, for example, a hollow needle piercing the liquid storage unit 36. The upstream end of the supply flow path 26 may be provided on the mounting portion 25. By connecting the supply flow path 26 to the liquid storage unit 36 mounted on the mounting portion 25, the liquid stored in the liquid storage unit 36 can be led out. The downstream end of the supply flow path 26 in the supply direction Ds is connected to the liquid ejection head 12. The supply flow path 26 supplies liquid from the liquid storage unit 36 to the liquid ejection head 12.

[0024] The supply flow path 26 is provided with a first connection portion 38 and a second connection portion 39. The first connection portion 38 is provided upstream of the liquid feeding portion 31. The first connection portion 38 may be provided between the upstream end of the supply flow path 26 and the liquid feeding portion 31. The second connection portion 39 is provided downstream of the liquid feeding portion 31. The second connection portion 39 is provided between the liquid feeding portion 31 and the pressure regulating valve 34. The second connection portion 39 may be provided between the buffer 32 and the degassing portion 33.

[0025] The branch flow path 27 branches from the supply flow path 26. The branch flow path 27 may be connected to the first connection portion 38 and the second connection portion 39. That is, the branch flow path 27 may branch from the supply flow path 26 at the first connection portion 38 and merge into the supply flow path 26 at the second connection portion 39. The branch flow path 27 may branch from the supply flow path 26 at the second connection portion 39 and merge into the supply flow path 26 at the first connection portion 38.

[0026] The liquid can flow through the branched channel 27 in a first branching direction D1 and in a second branching direction D2 opposite to the first branching direction D1. The first branching direction D1 is the direction from the first connection 38 toward the second connection 39. The second branching direction D2 is the direction from the second connection 39 toward the first connection 38.

[0027] The resistance channel 29 is provided in the branch channel 27. The cross-sectional area of ​​the resistance channel 29 may be smaller than the cross-sectional area of ​​the branch channel 27. The resistance channel 29 may be narrower than the branch channel 27. The resistance channel 29 may be meandering. The resistance channel 29 increases the resistance of the branch channel 27. Specifically, the resistance of the branch channel 27 is greater than the resistance of the supply channel 26 between the liquid delivery unit 31 and the pressure regulating valve 34. The resistance of the branch channel 27 is greater than the resistance of the supply channel 26 between the second connection unit 39 and the pressure regulating valve 34. The resistance channel 29 makes the flow rate of liquid flowing through the branch channel 27 smaller than the flow rate of liquid flowing through the supply channel 26.

[0028] The parallel flow path 28 is provided in parallel with the branch flow path 27. The parallel flow path 28 is connected to both sides of the resistance flow path 29. Specifically, the parallel flow path 28 is connected to the branch flow path 27 between the resistance flow path 29 and the first connection part 38, and to the branch flow path 27 between the resistance flow path 29 and the second connection part 39.

[0029] The regulator 30 is installed in the parallel flow path 28. The regulator 30 opens and closes the parallel flow path 28 according to the pressure difference between the parallel flow path 28 on the first connection part 38 side and the parallel flow path 28 on the second connection part 39 side. When the pressure difference is small, the regulator 30 closes the parallel flow path 28. When the pressure difference becomes larger than the set pressure, the regulator 30 opens the parallel flow path 28.

[0030] The liquid delivery unit 31 is provided in the supply channel 26 upstream of the pressure regulating valve 34. The liquid delivery unit 31 may be provided between the first connection unit 38 and the buffer 32. The liquid delivery unit 31 delivers liquid in the supply direction Ds. The liquid delivery unit 31 pressurizes and supplies liquid to the liquid discharge head 12. The liquid delivery unit 31 may include a first one-way valve 41, a supply pump 42, and a second one-way valve 43.

[0031] The supply pump 42 is located between the first one-way valve 41 and the second one-way valve 43. The supply pump 42 is located in the supply passage 26. The supply pump 42 is, for example, a diaphragm pump.

[0032] The first one-way valve 41 is located upstream of the supply pump 42. The second one-way valve 43 is located downstream of the supply pump 42. The first one-way valve 41 and the second one-way valve 43 allow the flow of liquid downstream in the supply direction Ds and restrict the flow of liquid upstream.

[0033] The buffer 32 is provided in the supply channel 26 between the liquid delivery section 31 and the second connection section 39. The buffer 32 stabilizes the pressure of the liquid flowing through the supply channel 26. The buffer 32 may also include a flexible member 45, a storage chamber 46, and a supply spring 47.

[0034] The storage chamber 46 is provided in the supply channel 26. The storage chamber 46 stores liquid. The flexible member 45 forms part of the wall surface of the storage chamber 46. The flexible member 45 is flexible and deformable. The flexible member 45 changes the volume of the storage chamber 46. The supply spring 47 pushes the flexible member 45 from the outside of the storage chamber 46. The supply spring 47 adds supply pressure to the liquid in the storage chamber 46.

[0035] The pressure regulating valve 34 is located in the supply passage 26 downstream of the degassing section 33. The pressure regulating valve 34 stabilizes the pressure of the liquid supplied to the nozzle 16 by adjusting the pressure of the pressurized liquid being supplied. The pressure regulating valve 34 adjusts the pressure of the liquid in the liquid discharge head 12 to a pressure at which a meniscus is formed in the nozzle 16. The pressure regulating valve 34 opens the supply passage 26 when the downstream pressure falls below a predetermined pressure. For example, when liquid is discharged from the nozzle 16 or when liquid is drawn from the nozzle 16, the amount of liquid in the liquid discharge head 12 decreases and the liquid pressure drops. When the negative pressure downstream becomes large, the pressure regulating valve 34 opens the supply passage 26 and supplies liquid to the liquid discharge head 12.

[0036] <Vacuuming section> The degassing section 33 may include a bubble trap chamber 49, a bubble discharge channel 50, a valve unit 51, and an exhaust valve 52.

[0037] The bubble trap chamber 49 is provided in the supply channel 26. The bubble trap chamber 49 may also be provided between the second connection part 39 and the pressure regulating valve 34. The bubble trap chamber 49 contains bubbles in the supply channel 26. The bubble trap chamber 49 may collect bubbles that have flowed together with the liquid at the top of the bubble trap chamber 49.

[0038] The bubble discharge channel 50 is connected to the bubble trap chamber 49. The bubble discharge channel 50 discharges bubbles from the bubble trap chamber 49. The bubble discharge channel 50 may also be connected to the bubble trap chamber 49 and the discharge channel 19.

[0039] The exhaust valve 52 is provided in the bubble discharge passage 50. The exhaust valve 52 may also be provided between the valve unit 51 and the discharge passage 19. The exhaust valve 52 can open and close the bubble discharge passage 50.

[0040] As shown in Figure 2, the valve unit 51 is installed in the bubble discharge channel 50. The valve unit 51 comprises a valve body 53 and an adjustment unit 54. The valve body 53 can open and close the bubble discharge channel 50. The valve body 53 may close the bubble discharge channel 50 by contacting the wall surface of the bubble discharge channel 50. The valve body 53 may open the bubble discharge channel 50 by moving away from the wall surface of the bubble discharge channel 50.

[0041] The adjustment unit 54 may include a pressure regulating spring 55 and a cam unit 56. The cam unit 56 may include a cam plate 57, a drive unit 58, a lever 59, a spring seat 60, and a retaining unit 61.

[0042] The adjustment unit 54 adjusts the opening pressure at which the valve body 53 opens the bubble discharge passage 50. Specifically, the pressure regulating spring 55 applies opening pressure to the valve body 53. The adjustment unit 54 adjusts the opening pressure by changing the force with which the pressure regulating spring 55 pushes the valve body 53.

[0043] The pressure regulating spring 55 is provided between the spring seat 60 and the retaining portion 61. The pressure regulating spring 55 presses against the retaining portion 61. The pressure regulating spring 55 closes the bubble discharge passage 50 by pressing the valve body 53 against the wall surface of the bubble discharge passage 50 via the retaining portion 61.

[0044] The cam plate 57 is a non-circular plate. The drive unit 58 rotates the cam plate 57. The lever 59 has an axis 63. The lever 59 is pivotable about the axis 63. One end of the lever 59 contacts the cam plate 57. The lever 59 is pivotable by following the contour of the rotating cam plate 57. The other end of the lever 59 supports the spring seat 60. The pivoting lever 59 causes the spring seat 60 to reciprocate.

[0045] The spring seat 60 supports the pressure regulating spring 55. The spring seat 60 may also movably support the retaining portion 61. The retaining portion 61 is movable in the direction in which the pressure regulating spring 55 pushes. The cam section 56 changes the length of the pressure regulating spring 55. The cam section 56 is displaceable between the discharge position Pd shown in Figure 2 and the standby position Ps shown in Figure 3. The discharge position Pd is the position taken when discharging bubbles. The standby position Ps is the position taken when in standby mode.

[0046] As shown in Figure 2, in the discharge position Pd, the cam portion 56 has the spring seat 60 positioned away from the valve body 53. The cam portion 56 in the discharge position Pd has a longer pressure regulating spring 55 than the cam portion 56 in the standby position Ps. In the discharge position Pd, the opening pressure at which the valve body 53 opens the bubble discharge passage 50 may be less than the pressure at which the liquid supply section 31 pressurizes the liquid. In the discharge position Pd, the opening pressure at which the valve body 53 opens the bubble discharge passage 50 may be less than the supply pressure at which the buffer 32 adds to the liquid.

[0047] The cam portion 56 in the discharge position Pd is moved to the standby position Ps by the drive unit 58 rotating the cam plate 57. Specifically, the lever 59 moves so as to push up the spring seat 60. The lever 59 compresses the pressure regulating spring 55 by bringing the spring seat 60 closer to the valve body 53.

[0048] As shown in Figure 3, in the standby position Ps, the cam portion 56 may have an opening pressure greater than the pressure at which the liquid supply portion 31 pressurizes the liquid, causing the valve body 53 to open the bubble discharge passage 50. In the standby position Ps, the cam portion 56 may have an opening pressure greater than the supply pressure at which the buffer 32 applies pressure to the liquid, causing the valve body 53 to open the bubble discharge passage 50.

[0049] <Operation of this embodiment> The operation of this embodiment will now be described. As shown in Figure 3, when printing on the medium, the control unit 23 sets the cam unit 56 to the standby position Ps.

[0050] As shown in Figure 1, the control unit 23 drives the liquid delivery unit 31. The liquid delivery unit 31 pressurizes the liquid downstream of the liquid delivery unit 31 by sending liquid in the supply direction Ds. When the liquid delivery unit 31 is driven, the pressure at the first connection part 38 is lower than the pressure at the second connection part 39. The liquid in the supply channel 26 flows from the second connection part 39 into the branch channel 27. The liquid that flows into the branch channel 27 flows in the second branch direction D2 and flows out from the first connection part 38 into the supply channel 26. However, the flow rate of the branch channel 27 is suppressed by the resistance channel 29. Therefore, liquid is more easily supplied to the liquid discharge head 12 from the branch channel 27. Liquid is supplied to the liquid discharge head 12 in accordance with the liquid discharge. Since the cam part 56 is in the standby position Ps, the bubble discharge channel 50 is blocked even when the liquid delivery unit 31 pressurizes and supplies liquid.

[0051] If the liquid storage unit 36 ​​becomes empty during printing, the control unit 23 stops the drive of the liquid supply unit 31. The control unit 23 may also notify the user to replace the liquid storage unit 36. Even if the liquid supply by the liquid supply unit 31 is stopped, the buffer 32 continues to supply the stored liquid. That is, the supply spring 47 applies supply pressure to the liquid in the storage chamber 46. Because the flow rate of the branch channel 27 is suppressed, the liquid supplied from the buffer 32 is easily supplied to the liquid discharge head 12 from the branch channel 27, just as when the liquid supply unit 31 was being driven. By providing the buffer 32, printing can continue even after the drive of the liquid supply unit 31 is stopped, up to the amount of stored liquid. Since the cam unit 56 is in the standby position Ps, the bubble discharge channel 50 remains closed even when the buffer 32 pressurizes and supplies liquid.

[0052] When printing to the medium is complete, the control unit 23 stops the operation of the liquid supply unit 31. When it is necessary to discharge bubbles from the bubble trap chamber 49, the control unit 23 sets the cam unit 56 to the discharge position Pd.

[0053] Specifically, when the drive of the liquid delivery unit 31 is stopped, it closes the supply passage 26. Immediately after the drive of the liquid delivery unit 31 is stopped, the liquid between the liquid delivery unit 31 and the pressure regulating valve 34 is subjected to the pressure that was pressurized on the liquid delivery unit 31 and the supply pressure from the supply spring 47. Therefore, when the cam section 56 is in the discharge position Pd, the valve body 53 receives the supply pressure from the buffer 32 and opens the bubble discharge passage 50. The bubbles in the bubble trap chamber 49 are discharged as they are pushed by the pressurized liquid.

[0054] The maintenance mechanism 13 may discharge the liquid that has entered the bubble discharge channel 50. The control unit 23 may move the liquid to the waste liquid storage section 22 by closing the drain valve 20 and driving the suction section 21 with the exhaust valve 52 open.

[0055] <Effects of this embodiment> The effects of this embodiment will now be explained. (1-1) The adjustment unit 54 adjusts the opening pressure. When the opening pressure is set higher than the pressure in the supply passage 26, the valve body 53 closes the bubble discharge passage 50. That is, the pressure in the supply passage 26 is maintained, so that liquid can be stably supplied to the liquid discharge head 12. When the opening pressure is set lower than the pressure in the supply passage 26, the valve body 53 opens the bubble discharge passage 50 in response to the pressure in the supply passage 26. Therefore, when bubbles are discharged and the pressure in the supply passage 26 decreases, the valve body 53 closes the bubble discharge passage 50. Thus, the risk of liquid leakage can be reduced.

[0056] (1-2) The cam section 56 changes the length of the pressure regulating spring 55. When the pressure regulating spring 55 is bent and shortened, its elastic force increases, and therefore the release pressure also increases. Thus, the release pressure can be adjusted with a simple configuration.

[0057] (1-3) The cam section 56 takes a standby position Ps when in standby mode and a discharge position Pd when bubbles are discharged. By displacing the cam section 56 from the standby position Ps to the discharge position Pd, the length of the pressure regulating spring 55 is increased. By increasing the length of the pressure regulating spring 55 when bubbles are discharged, the bubble discharge passage 50 can be opened more easily.

[0058] (1-4) The buffer 32 is provided in the supply channel 26. Therefore, the supply pressure added by the supply spring 47 also acts on the bubbles in the bubble trap chamber 49. When the cam section 56 takes the discharge position Pd, the opening pressure becomes smaller than the supply pressure, and the bubble discharge channel 50 is opened by the supply pressure. The liquid supplied to the bubble trap chamber 49 when bubbles are discharged is the liquid that was stored in the storage chamber 46. Therefore, the amount of bubbles and liquid discharged can be stabilized.

[0059] [Example of changes] This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0060] The cam portion 56 in the discharge position Pd may have an opening pressure greater than the supply pressure applied by the buffer 32 to the liquid, and less than the pressure applied by the liquid delivery unit 31 to pressurize the liquid, which causes the valve body 53 to open the bubble discharge passage 50. The control unit 23 may set the cam portion 56 to the discharge position Pd and drive the liquid delivery unit 31 to discharge bubbles from the bubble trap chamber 49.

[0061] The control unit 23 may be configured without a buffer 32. The control unit 23 may drive the liquid delivery unit 31 to discharge bubbles if a long time has elapsed since the last bubble discharge. The control unit 23 may also drive the liquid delivery unit 31 to discharge bubbles when the power to the liquid discharge device 11 is turned on.

[0062] The control unit 23 may control the cam section 56 and the supply pump 42 when filling the supply channel 26 with liquid. The control unit 23 may also set the cam section 56 to the discharge position Pd. The control unit 23 may also drive the supply pump 42 to fill the supply channel 26 with liquid up to the bubble trap chamber 49 while removing air from the supply channel 26 through the bubble discharge channel 50. When filling the supply channel 26 with liquid, the cam section 56 is set to the discharge position Pd. Therefore, when the supply pump 42 pressurizes the air in the supply channel 26, the valve body 53 is pushed by the pressurized air and opens the bubble discharge channel 50. Thus, compared to removing air from the supply channel 26, for example, through the liquid discharge head 12, air can be easily removed from the bubble discharge channel 50.

[0063] The liquid supply device 14 may include, for example, a solenoid to change the position of the spring seat 60. The liquid dispensing device 11 may be a liquid dispensing device that sprays or dispenses liquids other than ink. The state of the liquid dispensed from the liquid dispensing device as minute droplets may include granular, teardrop-shaped, or thread-like forms. The liquid referred to here may be any material that can be dispensed from the liquid dispensing device. For example, the liquid may be any state in which a substance is in the liquid phase, and may include highly or low viscosity liquids, sols, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals, and other fluids. The liquid may include not only liquids as a state of matter, but also functional material particles consisting of solids such as pigments and metal particles dissolved, dispersed, or mixed in a solvent. Typical examples of liquids include inks and liquid crystals as described in the above embodiments. Here, ink refers to general water-based inks and oil-based inks, as well as various liquid compositions such as gel inks and hot-melt inks. Specific examples of liquid dispensing devices include devices that dispense liquids containing materials such as electrode materials and colorants in the form of dispersion or dissolution, used in the manufacture of liquid crystal displays, electroluminescent displays, surface-emitting displays, and color filters. Liquid dispensing devices may also be devices that dispense bio-organic substances used in biochip manufacturing, devices that dispense liquid samples used as precision pipettes, printing devices, microdispensers, etc. Liquid dispensing devices may also be devices that dispense lubricating oil to precision machinery such as watches and cameras with pinpoint accuracy, or devices that dispense transparent resin liquids such as ultraviolet-curing resins onto substrates to form minute hemispherical lenses, optical lenses, etc. used in optical communication elements. Liquid dispensing devices may also be devices that dispense etching solutions such as acids or alkalis to etch substrates.

[0064] [Definition] As used herein, the expression "at least one" means "one or more" of the desired options. For example, as used herein, if there are two options, the expression "at least one" means "only one option" or "both of the two options." As another example, as used herein, the expression "at least one" means "only one option," "a combination of two arbitrary options," or "a combination of three or more arbitrary options" if there are three or more options.

[0065] [Note] The following describes the technical concepts and their effects that can be understood from the embodiments and modifications described above.

[0066] [1] A liquid supply device is a liquid supply device that can be connected to a liquid discharge head that discharges liquid from a nozzle, comprising: a supply channel for supplying liquid from a liquid storage section for storing liquid to the liquid discharge head; a bubble trap chamber provided in the supply channel for storing bubbles in the supply channel; a bubble discharge channel connected to the bubble trap chamber for discharging bubbles in the bubble trap chamber; and a valve unit provided in the bubble discharge channel, wherein the valve unit comprises a valve body that can open and close the bubble discharge channel, and an adjustment section that adjusts the opening pressure at which the valve body opens the bubble discharge channel.

[0067] In this configuration, the adjustment unit adjusts the opening pressure. If the opening pressure is greater than the pressure in the supply passage, the valve body closes the bubble discharge passage. That is, the pressure in the supply passage is maintained, so liquid can be stably supplied to the liquid discharge head. If the opening pressure is less than the pressure in the supply passage, the valve body opens the bubble discharge passage in response to the pressure in the supply passage. Therefore, when bubbles are discharged and the pressure in the supply passage decreases, the valve body closes the bubble discharge passage. Thus, the risk of liquid leakage can be reduced.

[0068] [2] In the liquid supply device described in [1] above, the adjustment unit may include a pressure regulating spring that applies the opening pressure to the valve body, and a cam unit that changes the length of the pressure regulating spring. In this configuration, the cam section changes the length of the pressure regulating spring. By bending and shortening the pressure regulating spring, the elastic force increases, and therefore the release pressure also increases. Thus, the release pressure can be adjusted with a simple configuration.

[0069] [3] In the liquid supply device described in [2] above, the cam portion is displaceable between a standby position taken when in standby mode and a discharge position taken when discharging bubbles, and the length of the pressure regulating spring may be longer in the cam portion in the discharge position than in the cam portion in the standby position.

[0070] In this configuration, the cam section assumes a standby position when idle and an exhaust position when bubbles are being discharged. By displacing the cam section from the standby position to the exhaust position, the length of the pressure regulating spring is increased. By lengthening the pressure regulating spring when bubbles are being discharged, the bubble discharge passage can be opened more easily.

[0071] [4] The liquid supply device described in [3] above includes a buffer provided in the supply channel, the buffer having a storage chamber for storing liquid, a flexible member forming a part of the wall surface of the storage chamber, and a supply spring pushing the flexible member from the outside of the storage chamber to apply supply pressure to the liquid in the storage chamber, the cam portion in the discharge position may have an opening pressure less than the supply pressure.

[0072] In this configuration, the buffer is located in the supply channel. Therefore, the supply pressure applied by the supply spring also acts on the bubbles in the bubble trap chamber. When the cam section assumes the discharge position, the opening pressure becomes smaller than the supply pressure, and the bubble discharge channel is opened by the supply pressure. The liquid supplied to the bubble trap chamber during bubble discharge is the liquid that was stored in the storage chamber. Therefore, the amount of bubbles and liquid discharged can be stabilized.

[0073] [5] The liquid supply device described in [3] above further comprises a supply pump provided in the supply channel and a control unit that controls the cam portion and the supply pump, wherein the control unit may set the cam portion to the discharge position when driving the supply pump to fill the supply channel with liquid.

[0074] In this configuration, when filling the supply channel with liquid, the cam section is positioned in the discharge position. Therefore, when the supply pump pressurizes the air in the supply channel, the valve body is pushed by the pressurized air and opens the bubble discharge channel. Consequently, air can be easily removed from the bubble discharge channel compared to, for example, removing air from the liquid discharge head.

[0075] [6] The liquid dispensing device comprises the liquid dispensing head and one of the liquid supply devices from [1] to [5] above. This configuration can achieve the same effects as the liquid supply device described above. [Explanation of symbols]

[0076] 11...Liquid discharge device, 12...Liquid discharge head, 13...Maintenance mechanism, 14...Liquid supply device, 16...Nozzle, 18...Cap, 19...Discharge channel, 20...Drain valve, 21...Suction section, 22...Waste liquid storage section, 23...Control unit, 25...Mounting section, 26...Supply channel, 27...Branch channel, 28...Parallel channel, 29...Resistance channel, 30...Regulator, 31...Liquid delivery section, 32...Buffer, 33...Degassing section, 34...Pressure regulating valve, 36...Liquid storage section, 38...First connection section, 39...Second connection section, 41...First one-way valve, 42...Supply pump, 43...Second one-way valve, 45...Flexible member, 46...Storage chamber, 47...Supply spring, 49...Bubble trap chamber, 50...Bubble discharge channel, 51...Valve unit, 52...Exhaust valve, 53...Valve body, 54...Adjustment part, 55...Pressure regulating spring, 56...Cam part, 57...Cam plate, 58...Drive part, 59...Lever, 60...Spring seat, 61...Pressing part, 63...Shaft, D1...First branching direction, D2...Second branching direction, Ds...Supply direction, Pd...Discharge position, Ps...Standby position.

Claims

1. A liquid supply device that can be connected to a liquid dispensing head that dispenses liquid from a nozzle, A supply channel that supplies liquid from a liquid storage section containing liquid to the liquid discharge head, A bubble trap chamber is provided in the supply channel and contains bubbles in the supply channel, A bubble discharge channel connected to the bubble trap chamber for discharging bubbles from within the bubble trap chamber, A valve unit provided in the aforementioned bubble discharge channel, Equipped with, The valve unit is A valve body capable of opening and closing the aforementioned bubble discharge channel, The valve body includes an adjustment unit that adjusts the opening pressure that opens the bubble discharge passage, A liquid supply device characterized by being equipped with the following features.

2. The adjustment unit is, The valve body is provided with a pressure regulating spring that applies the opening pressure, A cam section for changing the length of the pressure-regulating spring, The liquid supply device according to claim 1, characterized by comprising the following:

3. The cam portion is displaceable between a standby position taken during standby and a discharge position taken during bubble discharge. The liquid supply device according to claim 2, characterized in that the length of the pressure regulating spring is longer in the cam portion in the discharge position than in the cam portion in the standby position.

4. The supply channel is provided with a buffer, The aforementioned buffer is A storage chamber for storing liquid, A flexible member that forms a part of the wall surface of the storage chamber, A supply spring pushes the flexible member from the outside of the storage chamber to apply supply pressure to the liquid in the storage chamber, It has, The liquid supply device according to claim 3, characterized in that the cam portion in the discharge position makes the opening pressure less than the supply pressure.

5. A supply pump provided in the supply channel, A control unit that controls the cam section and the supply pump, Furthermore, The liquid supply device according to claim 3, characterized in that the control unit drives the supply pump to fill the supply channel with liquid and causes the cam portion to be in the discharge position.

6. The liquid dispensing head and, A liquid supply device according to any one of claims 1 to 5, A liquid dispensing device characterized by comprising the following features.

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