JP5907290B2 - Fluid ejection device - Google Patents

Description

  The present invention relates to a fluid ejecting apparatus such as an ink jet printer.

  In general, ink jet printers (hereinafter referred to as “printers”) are widely known as fluid ejecting apparatuses that eject fluid from a fluid ejecting head. This printer performs printing by supplying ink from an ink cartridge (fluid container) containing ink (fluid) to a recording head (fluid ejecting head) and ejecting the ink from a nozzle of the recording head onto recording paper. It is like that. Some inks used in such printers have a high specific gravity of color components (for example, pigments). If these inks are not used continuously, the color components will settle and the ink density will be biased. There's a problem.

  In order to deal with such problems, a printer as shown in Patent Document 1 has been proposed. In the printer of this Patent Document 1, the ink density is averaged by supplying ink from two ink cartridges containing the same type of ink to each sub-tank (fluid reservoir) and mixing them. Yes.

JP 2004-314418 A

  By the way, in the printer of Patent Document 1, the density of the ink in the ink cartridge increases as the remaining amount decreases. Therefore, when the ink is supplied from the two ink cartridges to the sub tank, the ink density in the sub tank is set for printing. The amount of ink supplied from each ink cartridge to the sub tank must be adjusted so as to obtain an appropriate density. In addition, when installing a new ink cartridge, it was necessary to shake the ink cartridge in order to agitate the pigment precipitated during storage. Therefore, there is a problem that the work for averaging the ink density is complicated.

  The present invention has been made paying attention to such problems existing in the prior art. An object of the present invention is to provide a fluid ejecting apparatus capable of easily and sufficiently stirring fluid.

In order to achieve the above object, a fluid ejecting apparatus of the present invention includes a fluid ejecting head capable of ejecting a fluid, and a fluid supply for supplying the fluid to the fluid ejecting head from a fluid container in which the fluid is accommodated. The fluid supply path includes a branch portion where the fluid supply path branches into a plurality of positions in the middle of the fluid supply path, and the branch fluid branched from the branch portion downstream of the branch portion. A pressure adjusting portion provided downstream of the merging portion in the fluid supply path, the fluid supply chamber communicating with the fluid supply path; When the pressure in the pressure chamber communicates with the supply chamber and the pressure in the pressure chamber becomes lower than a predetermined pressure, the valve is opened, and the fluid supply chamber and the pressure chamber communicate with each other, and the pressure in the pressure chamber becomes a predetermined pressure. Close the fluid supply chamber and the pressure chamber; An on-off valve that cuts off communication, a pressure adjusting unit that adjusts the pressure of the fluid that is supplied to the fluid ejecting head, and a fluid that is provided in the branch fluid supply path and that can flow in the branch fluid supply And a flow means for driving the flow means to cause the fluid in one branch fluid supply path to flow into the other branch fluid supply path .

According to this invention, the fluid can be easily and sufficiently agitated by causing the fluid in the one branch fluid supply path to flow into the other branch fluid supply path by the flow means.

In the fluid ejecting apparatus according to the aspect of the invention, an upstream on-off valve that can open and close the fluid supply path is provided on the upstream side of the branch portion in the fluid supply path, and the upstream on-off valve is closed. The flow means is driven .

In the fluid ejecting apparatus according to the aspect of the invention, the branch fluid supply path includes the fluid reservoir that can store the fluid, and the flow unit causes the fluid stored in the fluid reservoir to flow out to flow out the branch fluid. The fluid in the supply path is made to flow .

According to the present invention, the flow means, since the fluid to flow in the branch fluid supply passage by flowing out the fluid stored in the fluid storage portion, it is possible to flow better efficiency of fluid.

  In the fluid ejecting apparatus according to the aspect of the invention, a downstream on-off valve that can open and close the fluid supply path between the branch part and the merging part in the fluid supply path and downstream of the fluid storage parts. Are provided.

According to the present invention, by closing the downstream opening / closing valve, the fluid can flow on the upstream side of the downstream opening / closing valve in the fluid supply path by the flow means.
The fluid ejecting apparatus according to the aspect of the invention may further include delivery means for delivering the fluid accommodated in the fluid container to the downstream side, and the fluid supply path upstream of the branch portion in the fluid supply path. An upstream side opening / closing valve capable of opening / closing is provided.

According to the present invention, the fluid stored in the fluid container is sent to the downstream side by the sending means, and then the upstream on-off valve is closed. Can be prevented from flowing back to the fluid container.
In the fluid ejecting apparatus according to the aspect of the invention, the flow unit is a pressurizing unit that pressurizes the fluid stored in each of the fluid storage units, and is between the fluid storage unit and the junction unit in the branch fluid supply path. Each provided with a downstream on-off valve capable of opening and closing the branch fluid supply path, and after pressurizing one of the fluid reservoirs by the pressurizing means in a state where the downstream on-off valve is closed, The downstream opening / closing valve may be opened.
In the fluid ejecting apparatus of the present invention, the fluid may be caused to flow between the fluid reservoirs by the flow means in a state in which any one of the downstream opening / closing valves is closed.

In the fluid ejecting apparatus according to the aspect of the invention, the pressure applied to the fluid stored in each fluid storage unit by the pressurizing units is different from each other.
According to this invention, even if the fluid stored in all the fluid reservoirs is simultaneously pressurized by the pressurizing unit, the applied pressure from the fluid reservoir that stores the fluid with a large applied pressure is small. Since the fluid flows to the fluid storage section that stores the fluid, the fluid can be reliably flowed between the fluid storage sections.

1 is a schematic diagram illustrating an ink jet printer according to an embodiment. FIG. 3 is a schematic diagram illustrating a pressurizing mechanism that pressurizes a sub tank of the printer. In the pressure regulating valve of the printer, (a) is a simplified sectional view showing a closed state, and (b) is a simplified sectional view showing a valve opened state. FIG. 2 is a block diagram showing an electrical configuration of the printer.

Hereinafter, an embodiment in which a fluid ejecting apparatus of the invention is embodied in an ink jet printer will be described with reference to the drawings.
As shown in FIG. 1, an ink jet printer 11 as a fluid ejecting apparatus includes a main body frame 12 having a rectangular shape in plan view, and a platen 13 extends in the main frame in the left-right direction as the main scanning direction. It is extended. On the platen 13, the recording paper P is fed along the front-rear direction, which is the sub-scanning direction, by a paper feeding mechanism (not shown). A rod-shaped guide shaft 14 extending in parallel with the longitudinal direction (left-right direction) of the platen 13 is installed above the platen 13 in the main body frame 12.

  A carriage 15 is supported on the guide shaft 14, and the carriage 15 can reciprocate along the axial direction (left-right direction) of the guide shaft 14. The carriage 15 is partially provided on the back surface of the main body frame 12 via an endless timing belt 16 that is hung between a pair of pulleys 16 a provided on the inner surface of the rear wall of the main body frame 12. It is connected to. Accordingly, the carriage 15 is reciprocated along the guide shaft 14 by driving the carriage motor 17.

  A recording head 18 as a fluid ejecting head is supported on the lower surface of the carriage 15 facing the platen 13. On the other hand, on the carriage 15, a pressure adjustment valve 19 is provided as a pressure adjustment unit that adjusts the pressure of ink as a fluid supplied to the recording head 18. A plurality of nozzles (not shown) are opened on the lower surface of the recording head 18, and printing is performed by ejecting ink droplets onto the recording paper P fed onto the platen 13 from the openings of the nozzles. It has come to be.

  A cartridge holder 21 is provided at the right end in the main body frame 12, and one ink cartridge 22 as a fluid container that contains ink is detachably attached to the cartridge holder 21. The ink cartridge 22 includes a rectangular parallelepiped case 22a made of hard synthetic resin, and an ink pack 22b accommodated in the case 22a. The ink pack 22b is a bag made of a flexible film, and the inside thereof is filled with pigment-based ink. A sealed space in the case 22a, that is, a space between the inner surface of the case 22a and the outer surface of the ink pack 22b is an air chamber 22c.

  The cartridge holder 21 is connected to the pressure adjustment valve 19 on the carriage 15 via a flexible ink supply tube 23 that forms a fluid supply path. Further, a pressurizing pump 24 as a delivery means is provided directly above the cartridge holder 21, and the pressurizing pump 24 is connected to the cartridge holder 21 via a pressurizing tube 25.

  When the ink cartridge 22 is attached to the cartridge holder 21, the ink pack 22 b communicates with the recording head 18 via the ink supply tube 23 and the pressure adjustment valve 19, and the air chamber 22 c is added via the pressure tube 25. It communicates with the pressure pump 24. The pressure regulating valve 19 forms the downstream end of the fluid supply path.

  As shown in FIG. 1, the ink supply tube 23 has a branch portion B that branches into two branch tubes 23a and 23b in the middle of the ink supply tube 23, and branches at the branch portion B downstream of the branch portion B. It has the junction G where the two branch tubes 23a and 23b merge. That is, the ink supply tube 23 is branched into two branch tubes 23 a and 23 b between the branch portion B and the merge portion G, and each of the branch tubes 23 a and 23 b constitutes a part of the ink supply tube 23. Yes.

  Each branch tube 23a, 23b is provided with one sub-tank 26a, 26b as a fluid reservoir capable of storing ink. That is, the sub tanks 26a and 26b are arranged in parallel. Each of the sub tanks 26a and 26b is formed of a flexible film in a bag shape, and the inside thereof is an ink storage chamber capable of storing ink. The sub tanks 26a and 26b are provided with pressurizing mechanisms 27a and 27b for pressing the sub tanks 26a and 26b from the outside to pressurize the ink in the sub tanks 26a and 26b, respectively. The mechanisms 27a and 27b constitute a pressurizing means that is a flow means.

  On the downstream side of the sub tanks 26a and 26b in the branch tubes 23a and 23b, one downstream side open / close valve 28a and 28b capable of opening and closing the flow path in the branch tubes 23a and 23b is provided. Further, an upstream side opening / closing valve 29 capable of opening and closing the flow path in the ink supply tube 23 is provided at a position upstream of the branch portion B in the ink supply tube 23.

  A maintenance unit M for performing maintenance such as cleaning of the recording head 18 is provided in a position near the right end in the main body frame 12 and in the home position area of the carriage 15.

  Next, the configuration of each pressure mechanism 27a, 27b will be described in detail. In addition, since each pressurization mechanism 27a, 27b is the same structure, below, only the structure of the pressurization mechanism 27a is demonstrated, and description of the pressurization mechanism 27b is abbreviate | omitted.

  As shown in FIG. 2, the pressurizing mechanism 27a includes a pair of pressurizing plates 30a and 30b fixed to both sides of the subtank 26a so as to sandwich the subtank 26a, and the pressurizing plates 30a and 30b. It has a pair of air cylinders 31a and 31b that can move in the approaching and separating directions. Then, by driving the air cylinders 31a and 31b so that the pressurizing plates 30a and 30b move toward each other, the sub tank 26a is pinched and the ink in the sub tank 26a is pressurized. It has become. Note that while the pressurizing mechanism 27a is stopped, the pressurizing mechanism 27a is set so that the expansion and contraction of the sub-tank 26a is not hindered.

  A laser distance sensor 32 is provided at one end of the pressure plate 30a, and a reflector 33 that reflects the laser emitted from the laser distance sensor 32 is provided at one end of the pressure plate 30b. In this case, the laser distance sensor 32 and the reflecting plate 33 are arranged at positions where they face each other and no obstacle is located between them, and the distance between the laser distance sensor 32 and the reflecting plate 33 is the pressure plate 30a, It is set to be the same as the distance between 30b.

  The distance between the laser distance sensor 32 and the reflector 33 is determined by the control unit 56 described later from the time until the laser irradiated from the laser distance sensor 32 is reflected by the reflector 33 and returns to the laser distance sensor 32 again. That is, the distance between the pressure plates 30a and 30b is calculated. In this case, the distance between the pressure plates 30a and 30b and the ink amount in the sub tank 26a are in a proportional relationship, and the control unit 56 calculates the ink amount in the sub tank 26a from the distance between the pressure plates 30a and 30b. .

Next, the configuration of the pressure adjustment valve 19 will be described in detail.
As shown in FIGS. 3A and 3B, the pressure regulating valve 19 includes a base material 40 made of synthetic resin. A concave portion 41 is formed on one side surface of the base material 40, and a concave portion 42 is formed on the other side surface of the base material 40. An introduction path 43 formed so as to penetrate the base material 40 is opened on the side surface of the recess 42, and the introduction path 43 communicates with the ink supply tube 23. On the other hand, a discharge path 44 formed so as to penetrate the base material 40 is opened at the bottom surface of the recess 41, and the discharge path 44 communicates with the recording head 18.

  A spring seat 45 is fitted into the opening of the recess 42 so as to close the opening. A film 46 is fixed to the other side surface of the base material 40 so as to cover the recess 42 from above the spring seat 45. Thereby, an ink supply chamber 47 surrounded by the inner surface of the recess 42 and the film 46 is formed.

  A flexible film 48 is fixed to one side surface of the substrate 40 in a state where the concave portion 41 is slackened, and the concave portion 41 is hermetically sealed by the film 48. As a result, a pressure chamber 49 surrounded by the inner surface of the recess 41 and the film 48 is formed. A pressure receiving plate 50 corresponding to the concave portion 41 and narrower than the concave portion 41 is fixed to the central portion of the surface of the film 48 opposite to the concave portion 41 side.

  A partition wall 51 is provided between the pressure chamber 49 and the ink supply chamber 47 to partition the chambers 49, 47, and a communication hole 52 that connects the pressure chamber 49 and the ink supply chamber 47 is formed in the partition wall 51. It is formed to penetrate. The ink supply chamber 47 is connected to the spring receiving seat 45 via the coil spring 53, and has a substantially disc-like base portion 54 a that extends from the central portion of the base portion 54 a and is inserted into the communication hole 52. A valve body 54 including a rod-shaped rod portion 54b is disposed. In this case, the distal end of the rod portion 54 b of the valve body 54 reaches the close position of the film 48 in the pressure chamber 49.

  An annular seal member 55 is provided on the surface of the base portion 54 a of the valve body 54 on the partition wall 51 side so as to surround the rod portion 54 b, and the inner diameter of the seal member 55 is larger than the diameter of the communication hole 52. Is set to The valve body 54 is normally positioned at a valve closing position that is urged by the coil spring 53 and pressed against the partition wall 51. In other words, the pressure regulating valve 19 is normally closed in which the base portion 54a of the valve body 54 is in close contact with the partition wall 51 through the seal member 55 by the biasing force of the coil spring 53, and the communication hole 52 is closed by the valve body 54. It is in a valve state (state shown in FIG. 3A).

  When ink is ejected from the recording head 18 and consumed, the ink in the pressure chamber 49 is supplied to the recording head 18 from the ejection path 44. Then, as the amount of ink in the pressure chamber 49 decreases, a negative pressure is generated in the pressure chamber 49. When a negative pressure is generated in the pressure chamber 49, the film 48, particularly where the pressure receiving plate 50 is fixed, is pressed to the concave portion 41 side together with the pressure receiving plate 50 by the atmospheric pressure, and the rod portion 54 b of the valve body 54 Abuts the tip.

  Further, when the amount of ink in the pressure chamber 49 decreases, the negative pressure in the pressure chamber 49 increases (the pressure decreases), and the pressing force of the film 48 due to atmospheric pressure becomes larger than the biasing force of the coil spring 53. In this case, the rod portion 54 b (valve element 54) is pressed against the spring receiving seat 45 side by the pressure receiving plate 50 through the film 48 against the biasing force. By this pressing, the valve body 54 is moved to the spring seat 45 side, and the pressure regulating valve 19 is in a valve open state (state shown in FIG. 3B) in which the seal member 55 and the partition wall 51 are separated.

  Then, the ink in the ink supply chamber 47 flows into the pressure chamber 49 through the communication hole 52, and the negative pressure in the pressure chamber 49 is eliminated. By eliminating the negative pressure in the pressure chamber 49, the valve body 54 is moved to the pressure chamber 49 side by the biasing force of the coil spring 53, and the pressure regulating valve 19 is closed again with the communication hole 52 blocked by the valve body 54. It becomes a valve state.

  As described above, the pressure regulating valve 19 is in the closed state due to the displacement operation of the valve body 54, the generation of the negative pressure accompanying the decrease in the ink amount in the pressure chamber 49, the open state, the increase in the ink amount in the pressure chamber 49. The pressure in the pressure chamber 49 is kept constant by repeating the elimination of the negative pressure and the valve closing state associated with. The pressure adjustment valve 19 is a so-called self-sealing valve, and has a function of adjusting the pressure of ink supplied to the recording head 18 (self-sealing function).

Next, the electrical configuration of the ink jet printer 11 will be described.
As shown in FIG. 4, the ink jet printer 11 includes a control unit 56 that controls the operating state of the ink jet printer 11. The controller 56 is electrically connected to the carriage motor 17, the pressurizing pump 24, the downstream on-off valves 28 a and 28 b, the upstream on-off valve 29, the air cylinders 31 a and 31 b, and the laser distance sensor 32. The control unit 56 controls the carriage motor 17, the pressure pump 24, and the air cylinders 31 a and 31 b and also controls the opening and closing operations of the downstream opening and closing valves 28 a and 28 b and the upstream opening and closing valve 29. It has become.

  The control unit 56 stores a table indicating the relationship between the distance between the pressure plates 30a and 30b and the amount of ink in the sub tanks 26a and 26b. The control unit 56 receives the table and the laser distance sensor 32 from the table. Based on the transmitted signal, the ink amount in each of the sub tanks 26a and 26b is calculated.

Next, the operation of the ink jet printer 11 will be described.
When printing on the recording paper P, first, the ink cartridge 22 is mounted on the cartridge holder 21, and the downstream on-off valves 28a and 28b and the upstream on-off valve 29 are opened. Subsequently, when the pressure pump 24 is driven, pressurized air is supplied to the air chamber 22 c of the ink cartridge 22 through the pressure tube 25.

  Then, the ink pack 22 b is pressed by the pressurized air, and the ink in the ink pack 22 b is supplied to the sub tanks 26 a and 26 b via the ink supply tube 23. When the ink in each of the sub tanks 26a and 26b reaches a predetermined amount, the pressurizing pump 24 is stopped and the upstream side open / close valve 29 is closed. In this case, the predetermined amount of ink in each sub tank 26a, 26b is set to about half of the capacity of each sub tank 26a, 26b.

  Subsequently, the downstream on-off valve 28b is closed, and when the sub tank 26a is pressed by the pressurizing mechanism 27a, the ink in the sub tank 26a is pressurized and the ink is pressure-adjusted via the ink supply tube 23. To be supplied. Subsequently, when the recording head 18 is cleaned by the maintenance unit M, ink is supplied from the pressure adjusting valve 19 to the recording head 18. Thereafter, the recording paper P is printed by ejecting ink onto the recording paper P from the opening of each nozzle (not shown) of the recording head 18.

  Here, when the recording paper P has been printed and left for a long time, the pigment component in the ink in each of the sub tanks 26a and 26b and the ink supply tube 23 settles, and the ink density is biased. For this reason, if the next printing is performed in this state, the print quality of the recording paper P may be significantly lowered.

  For this reason, in the present embodiment, the ink in each of the sub tanks 26a and 26b and the ink supply tube 23 is set as follows between print jobs, for a preset time, or when the ink jet printer 11 is turned on. The concentration of the ink is averaged by stirring with a simple method.

  When the ink in the sub tanks 26a and 26b and the ink supply tube 23 is agitated, first, the downstream on / off valves 28a and 28b are opened, and the upstream on / off valve 29 is closed. Subsequently, when the pressure in the sub tank 26a is pressurized by the pressure mechanism 27a with the pressure mechanism 27b stopped, the ink flows into the sub tank 26b through the branch tube 23a, the branch portion B, and the branch tube 23b. At the same time, it flows into the sub tank 26b through the branch tube 23a, the junction G, and the branch tube 23b.

  Subsequently, when the pressure in the sub tank 26b is pressurized by the pressure mechanism 27b while the pressure mechanism 27a is stopped, the ink flows into the sub tank 26a via the branch tube 23b, the branch portion B, and the branch tube 23a. At the same time, it flows into the sub tank 26a via the branch tube 23b, the junction G, and the branch tube 23a.

  As a result, ink is replenished (flowed) between the sub-tanks 26a and 26b, so that the ink in the sub-tanks 26a and 26b and the branch tubes 23a and 23b (ink supply tubes 23) is effectively stirred. The As a result, the ink density is averaged, that is, the uneven ink density is eliminated.

  Further, when the lengths of the branch tubes 23a, 23b from the sub tanks 26a, 26b to the junction G are long, the downstream open / close valves 28a, 28b and the upstream open / close valve 29 are closed in the state described above. Similarly to the above, ink may be replenished between the sub-tanks 26a and 26b. In this way, the ink flows between the sub-tanks 26a and 26b through the flow path via the short-distance branch portion B, but does not flow through the flow path via the long-distance confluence portion G. As a result, even when the lengths of the branch tubes 23a and 23b from the sub tanks 26a and 26b to the merging portion G are long, it is possible to suppress a decrease in ink stirring efficiency. Incidentally, in this case, when the downstream side on-off valves 28a and 28b are opened, the ink also flows through the flow path through the junction portion G having a long distance between the sub tanks 26a and 26b, and therefore, between the sub tanks 26a and 26b. In other words, it takes time to replenish ink, and the stirring efficiency of the ink decreases.

  Further, when the ink in the ink cartridge 22 is also left for a long time, the pigment settles and the density is biased. Therefore, when the ink in the ink pack 22b of the ink cartridge 22 is agitated, first, each downstream opening and closing is performed. The valves 28a and 28b are closed and the upstream opening / closing valve 29 is opened. Subsequently, in a state where the pressurizing pump 24 is stopped, at least one of the sub tanks 26a and 26b is pressurized by the corresponding pressurizing mechanisms 27a and 27b. Then, at least one of the sub tanks 26a and 26b flows back into the ink pack 22b of the ink cartridge 22, and the ink in the ink pack 22b is agitated.

As described above, according to the embodiment described in detail, the following effects can be obtained.
(1) By mutually pressurizing the ink stored in each sub-tank 26a, 26b by each pressurizing mechanism 27a, 27b, the mutual replenishment of ink via each branch tube 23a, 23b between each sub-tank 26a, 26b. Is made. Therefore, the ink in each sub tank 26a, 26b and each branch tube 23a, 23b can be stirred easily and fully.

  (2) Since each sub tank 26a, 26b is connected in parallel to the same one ink cartridge 22 by the ink supply tube 23, it is stored in each sub tank 26a, 26b by each pressurizing mechanism 27a, 27b. Ink can be efficiently replenished (flowed) between the sub-tanks 26a and 26b.

  (3) Downstream on-off valves 28a and 28b capable of opening and closing the inside of the branch tubes 23a and 23b are provided at positions downstream of the sub tanks 26a and 26b in the branch tubes 23a and 23b, respectively. For this reason, when the length of each branch tube 23a, 23b from each sub tank 26a, 26b to the junction G is long, each downstream side on-off valve 28a, 28b is closed, By replenishing ink between the sub tanks 26a and 26b, it is possible to suppress a decrease in ink stirring efficiency.

(4) The ink jet printer 11 includes a pressurizing pump 24 that pressurizes ink in the ink cartridge 22, and an upstream opening / closing valve 29 provided on the upstream side of the branch portion B in the ink supply tube 23. . For this reason, the ink stored in the ink cartridge 22 is pressurized by the pressurizing pump 24 and then supplied to the sub tanks 26a and 26b, and then the upstream open / close valve 29 is closed, whereby each branch tube is connected between the sub tanks 26a and 26b. It is possible to prevent the ink from flowing back to the ink cartridge 22 when the ink is replenished via 23a and 23b.
(Example of change)
In addition, you may change the said embodiment as follows.

  A difference may be made in the magnitude of the pressure applied to the ink stored in each sub tank 26a, 26b by each pressurizing mechanism 27a, 27b. In this way, even if the sub tanks 26a and 26b are simultaneously pressurized by the pressurizing mechanisms 27a and 27b, the ink flows from the strongest to the weakest applied pressure to the ink between the subtanks 26a and 26b. Therefore, the ink can be reliably stirred. In this case, if the weaker pressing force is set so that the ink can be supplied to the pressure adjusting valve 19, even if the ink is stirred during printing, the pressure adjusting valve 19 is stabilized. Ink can be supplied.

Ink agitation may be performed simply by supplying ink from one of the sub-tanks 26a and 26b to the other.
-When ink is replenished between the sub-tanks 26a and 26b, one of the downstream on-off valves 28a and 28b may be closed.

  When the inks are replenished between the sub tanks 26a and 26b, the respective downstream side on-off valves 28a and 28b are opened after pressurizing any one of the inks in the sub tanks 26a and 26b. Also good. In this way, since the ink can be vigorously flowed, the ink can be effectively stirred.

  A tube pump for sending ink from the ink cartridge 22 to each of the sub tanks 26 a and 26 b may be provided in the branch portion B of the ink supply tube 23, and the tube pump may be used as a sending means instead of the pressurizing pump 24. .

  -Tube pumps for sucking and flowing ink in the sub-tanks 26a, 26b are provided at positions downstream of the sub-tanks 26a, 26b in the branch tubes 23a, 23b, respectively. Instead of the pressurizing mechanisms 27a and 27b, they may be used as flow means.

  -By driving the pressurizing mechanisms 27a and 27b so that the pressurizing plates 30a and 30b are separated from each other, the volumes of the subtanks 26a and 26b are increased to generate negative pressure in the subtanks 26a and 26b. Ink may be replenished between the sub-tanks 26a and 26b using the generated negative pressure.

  A plurality of ink cartridges 22 may be mounted on the cartridge holder 21. In this case, the two ink cartridges 22 communicate with the sub tanks 26 a and 26 b through the ink supply tube 23.

-You may use three or more subtanks as a fluid storage part. In this case, the number of sub tanks provided in each branch tube 23a, 23b may be set arbitrarily.
-Both the sub tanks 26a, 26b may be provided in one of the branch tubes 23a, 23b, and the sub tanks 26a, 26b may be arranged in series.

  The sub tanks 26a and 26b and the ink cartridge 22 may be configured by containing ink in a hard container, and the ink in each container may be pressurized with air by a pressure pump or the like. Good.

The ink in the ink cartridge 22 may be sent to each of the sub tanks 26a and 26b due to a water head difference. In this case, the pressurizing pump 24 becomes unnecessary.
The ink supply tube 23 may be configured to branch into three or more branch tubes at the branch portion B.

-At least one of the downstream opening / closing valves 28a, 28b and the upstream opening / closing valve 29 may be omitted.
In the above embodiment, the ink jet printer 11 is employed, but a fluid ejecting apparatus that ejects or ejects fluid other than ink may be employed. Further, the present invention can be used for various liquid ejecting apparatuses including a liquid ejecting head that ejects a minute amount of liquid droplets. In this case, the droplet refers to the state of the liquid ejected from the liquid ejecting apparatus, and includes liquid droplets having a granular shape, a tear shape, and a thread shape. The liquid here may be any material that can be ejected by the liquid ejecting apparatus. For example, it may be in a state in which the substance is in a liquid phase, such as a liquid with high or low viscosity, sol, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals (metal melts ) And liquids as one state of the substance, as well as those obtained by dissolving, dispersing or mixing particles of a functional material made of solid materials such as pigments and metal particles in a solvent. Further, representative examples of the liquid include ink and liquid crystal as described in the above embodiment. Here, the ink includes general water-based inks and oil-based inks, and various liquid compositions such as gel inks and hot-melt inks. As a specific example of the liquid ejecting apparatus, for example, a liquid containing a material such as an electrode material or a coloring material used for manufacturing a liquid crystal display, an EL (electroluminescence) display, a surface light emitting display, a color filter or the like in a dispersed or dissolved form. It may be a liquid ejecting apparatus for ejecting, a liquid ejecting apparatus for ejecting a bio-organic matter used for biochip manufacturing, a liquid ejecting apparatus for ejecting a liquid used as a precision pipette, a printing apparatus, a microdispenser, or the like. In addition, transparent resin liquids such as UV curable resin to form liquid injection devices that pinpoint lubricant oil onto precision machines such as watches and cameras, and micro hemispherical lenses (optical lenses) used in optical communication elements. A liquid ejecting apparatus that ejects a liquid onto the substrate or a liquid ejecting apparatus that ejects an etching solution such as an acid or an alkali to etch the substrate may be employed. The present invention can be applied to any one of these liquid ejecting apparatuses.

  DESCRIPTION OF SYMBOLS 11 ... Inkjet printer as a fluid ejecting apparatus, 18 ... Recording head as a fluid ejecting head, 19 ... Pressure adjusting valve as a pressure adjusting unit forming a fluid supply path, 22 ... Ink cartridge as a fluid container, 23 ... Ink supply tube forming a fluid supply path, 24... Pressurizing pump as delivery means, 26 a and 26 b... Sub-tank as fluid reservoir, 27 a and 27 b. 28b ... downstream side on-off valve, 29 ... upstream side on-off valve, B ... branching part, G ... merging part.

Claims (6)

A fluid ejecting apparatus comprising: a fluid ejecting head capable of ejecting a fluid; and a fluid supply path for supplying the fluid from the fluid container in which the fluid is accommodated to the fluid ejecting head,
The fluid supply path has a branch portion where the fluid supply path branches into a plurality of positions in the middle of the fluid supply path, and a junction where the branched branch fluid supply path merges downstream from the branch portion. ,
A pressure adjusting unit provided on the downstream side of the merging unit in the fluid supply path, the fluid supply chamber communicating with the fluid supply path, the pressure chamber communicating with the fluid supply chamber, When the pressure becomes lower than a predetermined pressure, the valve is opened to connect the fluid supply chamber and the pressure chamber. When the pressure in the pressure chamber reaches a predetermined pressure, the valve is closed, and the fluid supply chamber and the pressure chamber are closed. A pressure adjusting unit that adjusts the pressure of the fluid supplied to the fluid ejecting head.
A flow means provided in the branch fluid supply path and capable of flowing the fluid in the branch fluid supply;
Fluid ejecting apparatus characterized by flowing the fluid in one of the branch fluid supply passage to another of the branch fluid supply passage by driving the flow means. An upstream on-off valve that can open and close the fluid supply path is provided upstream of the branch portion in the fluid supply path,
The fluid ejecting apparatus according to claim 1, wherein the flow unit is driven in a state where the upstream side opening / closing valve is closed. The fluid storage section capable of storing the fluid in the branch fluid supply path,
3. The fluid ejecting apparatus according to claim 1, wherein the flow unit causes the fluid in the branch fluid supply path to flow by causing the fluid stored in the fluid storage unit to flow out. 4. A downstream on-off valve capable of opening and closing the branch fluid supply path is provided between the fluid storage section and the merging section in the branch fluid supply path,
The fluid ejecting apparatus according to claim 3, wherein the fluid in the branch fluid supply path is caused to flow by the flow means in a state in which the downstream side on-off valve is closed. The fluid storage section capable of storing the fluid in each of the branch fluid supply paths,
The flow means is a pressurizing means for pressurizing the fluid stored in each fluid storage section,
A downstream on-off valve capable of opening and closing the branch fluid supply path is provided between the fluid storage section and the merging section in the branch fluid supply path, respectively.
2. The fluid ejecting apparatus according to claim 1, wherein the downstream side on-off valve is opened after pressurizing one of the fluid reservoirs with the pressurizing unit in a state in which the downstream side on-off valve is closed. . The fluid storage section capable of storing the fluid in each of the branch fluid supply paths,
Between the fluid storage part and the merging part in the branch fluid supply path, a downstream on-off valve capable of opening and closing the fluid supply path is provided, respectively.
2. The fluid ejecting apparatus according to claim 1, wherein the fluid is caused to flow between the fluid reservoirs by the flow means in a state in which one of the downstream opening / closing valves is closed.

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