Liquid dispensing device

Abstract

To reduce injection time of an ink into an ink tank.SOLUTION: An inkjet recording device includes: an ink tank having an ink storage chamber which stores an ink to be supplied to a recording head which discharges the ink, and an injection port for injecting the ink into the ink storage chamber; and an injection assisting member having a first passage, defined by a first upper end part which is open to the outside of the ink tank and a first lower end part which is open to the inside of the ink tank, and a second passage, defined by a second upper end part which is open to the outside of the ink tank and a second lower end part which is open to the inside of the ink tank, the injection assisting member used to assist the injection of the ink from the injection port to the ink storage chamber. The second passage is provided with en expanded part in which a step is formed in a middle of a range from the second upper end part to the second lower end part to expand a sectional area.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a liquid ejection apparatus for ejecting liquid. To Regarding. [Background technology]

[0002] Patent Document 1 discloses a configuration in which multiple flow paths that pass through an opening in an ink tank and into the tank serve as ink flow paths and air flow paths, making it possible to replenish ink while performing gas-liquid exchange between an ink supply container and the ink tank. This allows a user to replenish ink into the ink tank without squeezing the ink supply container. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-161887 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the configuration of Patent Document 1, when injecting ink from an ink supply container into an ink tank, it can take time to determine which of the multiple flow paths is through which ink flows and which is through which air flows, which can lead to a decrease in the ink injection speed and a longer time required to inject ink.

[0005] The present invention has been made in view of the above problems, Ta To liquid The injection time was reduced liquid discharge The present invention aims to provide an apparatus. [Means for solving the problem]

[0006] In order to solve the above problems, the liquid ejection device according to the present invention is a liquid ejection device that includes a tank having a storage chamber that stores liquid to be supplied to an ejection head that ejects the liquid, and a first upper end portion that opens toward the outside of the storage chamber and a first lower end portion that opens toward the inside of the storage chamber. A liquid flows into the storage chamber from a supply container for supplying the liquid to the storage chamber. a second upper end portion opening toward the outside of the storage chamber and a second lower end portion opening toward the inside of the storage chamber. Air flows from the storage chamber to the supply container. and a second flow path having a stepped portion where a cross-sectional area of ​​the second flow path is enlarged, the stepped portion being formed at a position closer to the second upper end than to the second lower end. The step portion is determined to be a flow path through which air flows due to a pressure loss caused by a vortex generated at the step portion. It is characterized by the above. Effect of the Invention

[0007] According to the present invention, Ta To liquid The injection time was reduced liquid discharge An apparatus can be provided. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view showing an internal configuration of an inkjet recording apparatus according to a first embodiment. [Diagram 2] FIG. 2 is a schematic perspective view of an ink tank according to the first embodiment. [Diagram 3] FIG. 2 is a schematic cross-sectional view of a needle according to the first embodiment. [Figure 4] 5A to 5C are schematic cross-sectional views showing the ink injection operation according to the first embodiment. [Diagram 5] 5 is an enlarged cross-sectional view illustrating a schematic view of the flow of ink in a needle according to the first embodiment. FIG. [Figure 6] FIG. 13 is a cross-sectional view showing a comparative example in which a slope is not formed on the upper end of the needle. [Figure 7] FIG. 2 is a schematic cross-sectional view illustrating an upper end portion of a needle according to the first embodiment. [Figure 8] FIG. 11 is a schematic cross-sectional view of a needle according to a second embodiment. [Figure 9]13A to 13C are schematic cross-sectional views showing the ink injection operation according to the second embodiment. [Figure 10] FIG. 11 is a schematic cross-sectional view of a needle according to a third embodiment. [Figure 11] FIG. 13 is a schematic cross-sectional view of a needle according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [First embodiment] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the following embodiments do not limit the present invention, and not all of the combinations of features described in the embodiments are necessarily essential to the solution of the present invention. Furthermore, the relative arrangements, shapes, etc. of the components described in the embodiments are merely examples, and are not intended to limit the scope of the present invention to only those.

[0010] <Device configuration> Fig. 1 is a perspective view showing the internal configuration of an inkjet recording device (hereinafter, recording device) 100 in this embodiment. The recording device 100 includes a housing 1, a recording unit 5 that performs a recording operation on a recording medium, and an ink tank 8 as an ink storage container that contains ink to be supplied to the recording unit 5. In this embodiment, the ink tank 8 is disposed on the front side of the housing 1 and is fixed to the device body. The recording device 100 includes a cover (not shown) that can be opened and closed relative to the housing 1, and Fig. 1 shows the cover in an open state. The cover (not shown) may include a scanner unit that can read a document.

[0011] The recording device 100 separates the recording media loaded in a paper feed cassette 2 provided on the front side of the housing 1 or in a paper feed tray 3 provided on the rear side of the housing 1 into individual sheets, and feeds the separated sheets by a feeding means (not shown). The recording media fed by the feeding means are transported by a transport roller 4 as a transport means to a recording position facing a recording unit 5, where recording is performed based on data by the recording unit 5. The recording media on which recording has been completed by the recording unit 5 is discharged by a discharge means (not shown) to a paper discharge tray (discharge unit) 101 provided above the paper feed cassette 2.

[0012] The direction in which the recording medium is transported by the transport unit (Y direction in FIG. 1) is referred to as the transport direction. That is, the upstream side of the transport direction corresponds to the rear side of the housing 1, and the downstream side of the transport direction corresponds to the front side of the housing 1.

[0013] The recording unit 5 in this embodiment includes a recording head having ejection ports for ejecting ink. The recording unit 5 is mounted on a carriage 6 that moves back and forth in a main scanning direction (X direction shown in FIG. 1) that intersects with the transport direction. In this embodiment, the transport direction and the main scanning direction are perpendicular to each other. The recording unit (recording head) 5 ejects ink droplets while moving in the main scanning direction together with the carriage 6, and records an image of a predetermined length (one band) on the recording medium (recording operation). After one band of image has been recorded, the recording medium is transported a predetermined amount by a transport means (intermittent transport operation). By repeating this one band recording operation and intermittent transport operation, an image is recorded on the entire recording medium based on image data.

[0014] The print head in this embodiment is equipped with a means for generating thermal energy (for example, a heat generating resistor element) as the energy used for ink ejection, and uses a method in which the thermal energy causes a change in the state of the ink (film boiling). This achieves high density and high definition image recording. Note that the present invention is not limited to such a method using thermal energy, and may also use a method using vibration energy in a configuration equipped with a piezoelectric element.

[0015] In this embodiment, an example of a serial head in which the recording head of the recording unit 5 is mounted on a carriage 6 is shown, but the present invention is not limited to this and can also be applied to a line head in which multiple ejection ports are arranged in an area corresponding to the width of the recording medium.

[0016] An ink tank 8 is provided in the recording device 100 for each color of ink that can be ejected by the recording head of the recording unit 5. In this embodiment, there is a black ink tank 8K that contains black ink, a cyan ink tank 8C that contains cyan ink, a magenta ink tank 8M that contains magenta ink, and a yellow ink tank 8Y that contains yellow ink. These four ink tanks are collectively referred to as the ink tank 8. Note that cyan ink, magenta ink, and yellow ink are merely examples of color inks, and the present invention is not limited to these.

[0017] 1, the black ink tank 8K is disposed to the left of the paper discharge tray 101 and paper feed cassette 2 when viewed from the front of the recording device 100. On the other hand, the cyan ink tank 8C, the magenta ink tank 8M, and the yellow ink tank 8Y are disposed to the right of the paper discharge tray 101 and paper feed cassette 2 when viewed from the front of the recording device 100. In other words, the paper discharge tray 101 and the paper feed cassette 2 are disposed so as to be sandwiched between the black ink tank 8K and the color ink tanks. Each ink tank 8 is connected to the recording unit 5 by a flexible supply tube 7 that constitutes a supply flow path for supplying ink to the recording unit 5.

[0018] <Ink tank configuration> FIG. 2 is a schematic perspective view of the ink tank 8. The ink tank 8 includes an ink chamber 9 that contains ink, and an ink supply port 10 to which a supply tube 7 is connected for supplying the ink in the ink chamber 9 to a recording head. The ink tank 8 further includes an air inlet 11 for introducing air into the ink chamber 9 as the ink in the ink chamber 9 is consumed. The air inlet 11 is connected to a communication port 12 provided in the ink chamber 9, and an air chamber 13 capable of containing air is provided between the air inlet 11 and the communication port 12 (see FIG. 2(b)). The air chamber 13 can also store ink that flows back from the ink chamber 9, and this storage function prevents ink from leaking outside the ink tank 8.

[0019] Fig. 2(a) is a perspective view of the ink tank 8 seen from a first side surface, with the ink chamber 9 opening onto the first side surface. Fig. 2(b) is a perspective view of the ink tank 8 seen from a second side surface opposite the first side surface, with the air chamber 13 opening onto the second side surface. The openings of the ink chamber 9 and the air chamber 13 are each covered by a flexible film (not shown) to form a storage space.

[0020] An inlet 14, which is an opening for injecting ink, is provided on the top surface of the ink tank 8, and the inlet 14 can be sealed with a tank cap 15. The tank cap 15 is made of a material having rubber elasticity. A user can inject ink from the ink supply container 17 (see FIG. 4) into the ink tank 8 by removing the tank cap 15 from the inlet 14 and inserting the ink supply container 17 into the inlet 14.

[0021] <Needle configuration> The ink tank 8 further has a needle 18 attached to the inside of the inlet 14 as an injection assisting member that assists the injection of ink from the inlet 14. FIG.

[0022] The needle 18 is composed of a first flow path 21a and a second flow path 21b, and communicates the inside and outside of the ink tank 8. The first flow path 21a is defined by a first upper end 19a exposed above the upper end of the injection port 14 and opening toward the outside of the ink tank 8, and a first lower end 20a opening toward the inside of the ink tank 8 (ink storage chamber 9). The second flow path 21b is defined by a second upper end 19b exposed from the injection port 14 and opening toward the outside of the ink tank 8, and a second lower end 20b opening toward the inside of the ink tank 8 (ink storage chamber 9).

[0023] Both the first upper end 19a and the second upper end 19b open obliquely with respect to the direction in which the flow path extends, and are inclined toward the center where they contact each other. The opening area of ​​the first upper end 19a is larger than that of the second upper end 19b. The first flow path 21a is configured such that the opening area of ​​the first upper end 19a, the cross-sectional area in the middle of the flow path, and the opening area of ​​the first lower end 20a are all equal. On the other hand, the second flow path 21b has an expansion section 22 in the middle of the flow path, and the cross-sectional area of ​​the flow path between the expansion section 22 and the second lower end 20b is larger than the opening area of ​​the second upper end 19b. That is, the second flow path 21b has an expansion section 22 that forms a step in the middle of the flow path where the cross-sectional area suddenly expands.

[0024] Fig. 4 is a schematic cross-sectional view showing an ink injection operation in which an ink supply container 17 is attached to the injection port 14 of the ink tank 8. Fig. 5 is an enlarged cross-sectional view showing a schematic view of the flow of ink in a needle 18 when the ink injection operation is performed.

[0025] In the ink injection operation, one of the first flow path 21a and the second flow path 21b that form the needle 18 functions as a flow path through which ink flows, and the other functions as a flow path through which air flows. The ink supply container 17 has an opening that is sealed with a sealing member (not shown), and is configured so that ink does not drip even if the opening is facing downward until it is inserted into the injection port 14.

[0026] 4, when the ink supply container 17 is inserted into the inlet 14, the needle 18 (first upper end 19a and second upper end 19b) opens the sealing member of the ink supply container 17. As a result, the ink contained in the ink supply container 17 attempts to flow into the ink tank 8 through the first flow path 21a and the second flow path 21b.

[0027] At this time, as shown in FIG. 5, the second flow path 21b is provided with an expanded portion 22 that forms a step, and a vortex V is generated in the ink flowing through the second flow path 21b at the expanded portion 22. The generation of this vortex V causes a pressure loss, and the flow rate of the ink in the second flow path 21b decreases. In the first flow path 21a, which has a constant cross-sectional area from the first upper end 19a to the first lower end 20a, no step is formed in the flow path, so the flow of ink is not obstructed. As a result, the flow rate of the ink flowing through the first flow path 21a becomes faster than the flow rate of the ink flowing through the second flow path 21b, and more ink contained in the ink supply container 17 flows through the first flow path 21a than through the second flow path 21b.

[0028] The ink injection operation of this embodiment is performed by utilizing gas-liquid exchange between ink and air, and when ink flows from the ink supply container 17 into the ink tank 8, an amount of air equal to the amount of ink that has flowed in flows out from the ink tank 8 to the ink supply container 17. As described above, the first flow path 21a functions as a flow path for ink to flow into the ink tank 8, so that the air in the ink tank 8 flows out to the ink supply container 17 via the second flow path 21b. As a result, the first flow path 21a is determined as the flow path for ink, and the second flow path 21b is determined as the flow path for air.

[0029] If the second flow path 21b also has a constant cross-sectional area like the first flow path 21a, there will be no difference in the flow rate (ease of flow) of the ink in the first flow path 21a and the second flow path 21b, and the same amount of ink will flow in both paths. This will require time to determine the ink flow path and the air flow path. In addition, if ink and air are mixed in both the first flow path 21a and the second flow path 21b, and pressure balance occurs, the ink inflow may stop midway, and the ink injection operation may be interrupted.

[0030] In contrast, in the present embodiment, by providing an enlarged section that creates a step in the cross-sectional area of ​​one of the two flow paths, the ink is made to flow more easily into the other flow path, the flow path is quickly determined, and the time required for the ink injection operation is shortened.

[0031] In this embodiment, the opening area of ​​the first upper end 19a is larger than the opening area of ​​the second upper end 19b, so that the amount of ink flowing through the first flow path 21a tends to be large when the ink supply container 17 is attached. This can further facilitate the establishment of a flow path in the needle 18.

[0032] Furthermore, in the case of ink injection using air-liquid exchange, the more air flows out from the ink tank 8 to the ink supply container 17, the more ink flows from the ink supply container 17 into the ink tank 8. Therefore, the more easily air becomes bubbles and separates from the needle 18, the more the outflow of air into the ink supply container 17 is promoted, and the smoother the flow of ink into the ink tank 8 is.

[0033] In this embodiment, the first upper end 19a and the second upper end 19b have a slope, which makes it easier for air to move away from the needle 18 and promotes the outflow of air into the ink supply container 17. Details will be described with reference to Figures 6 and 7. Note that Figures 6 and 7 use the fourth embodiment, which will be described later, as an example, in which the height of the first upper end 19a is configured to be higher than the second upper end 19b, but the same phenomenon occurs in the configuration of the first embodiment.

[0034] Fig. 6 is a comparative example showing a configuration in which the first upper end 19a and the second upper end 19b are not formed with a slope, and Fig. 7 is a schematic diagram showing the first upper end 19a and the second upper end 19b having a slope as in this embodiment. Air flows out from the second flow path 21b to the ink supply container 17 according to the flow shown in Figs. 6(a) to 6(d) and 7(a) to 7(d). In order for air to flow out from the second upper end 19b toward the ink supply container 17 in which ink is stored, air bubbles must be formed and separated from the second upper end 19b, as shown in Figs. 6 and 7.

[0035] At this time, if a slope is not formed as in the comparative example shown in Fig. 6, the air bubbles need to leave the entire opening surface of second upper end 19b when transitioning from Fig. 6(b) to Fig. 6(c), which takes time. That is, the air bubbles are in surface contact with second upper end 19b, and the contact area is large, so the air bubbles are difficult to leave.

[0036] On the other hand, when the inclined surface is formed as in this embodiment shown in FIG. 7, the air bubble is easily formed because it separates from the top 19bb of the second upper end 19b when the state transitions from FIG. 7(b) to FIG. 7(c). That is, the air bubble is in line contact with the top 19bb, and the contact area is smaller than that in the case of FIG. 6, so that the air bubble is easily separated. Therefore, the air flows out smoothly from the ink tank 8 to the ink supply container 17, and the ink inflow speed from the ink supply container 17 to the ink tank 8 is also improved. Furthermore, the inclined surface is formed higher toward the portion where the first upper end 19a and the second upper end 19b contact each other, so that the air bubble rises while contacting the side surface of the first upper end 19a, which makes it even easier to separate (see FIG. 7(c)).

[0037] Here, even when there is no difference in height between first upper end 19a and second upper end 19b as in the first embodiment, second upper end 19b opens obliquely to the air bubbles moving upward, promoting the upward movement of the air bubbles. This makes it possible to reduce the contact area of ​​second upper end 19b more than in the comparative example shown in FIG.

[0038] As described above, in the needle 18 as an injection auxiliary member having a plurality of flow paths, an enlarged portion that forms a step and expands the cross-sectional area is provided in one of the flow paths, and no step is formed in the other flow path. As a result, the flow rate of ink decreases in one of the flow paths with the enlarged portion, and the flow rate of ink increases relatively in the other flow path, promoting the flow of ink into the ink tank 8 through the other flow path that does not have a step. In the ink injection operation by air-liquid exchange, the same amount of air as the ink that flows into the ink tank 8 must flow out to the ink supply container 17, so the flow of air is promoted in one of the flow paths that has a step. Due to the above flow, the flow path through which the ink flows and the flow path through which the air flows are quickly determined compared to when no enlarged portion (step) is formed in one of the flow paths, and the ink injection time can be shortened.

[0039] In this embodiment, the ink tank 8 is fixed to the recording device 100, and ink is supplied to the recording head by the supply tube 7, but the present invention is not limited to this, and can also be applied to a configuration in which the ink tank is mounted on the carriage 6 together with the recording head. That is, the ink tank mounted on the carriage 6 may be provided with an injection port and a needle, and the user may inject ink from an ink supply container.

[0040] Second Embodiment A second embodiment of the present invention will be described below with reference to the drawings. Note that the basic configuration of this embodiment is similar to that of the first embodiment, so only the characteristic configuration will be described below.

[0041] 8 is a schematic cross-sectional view of the needle 18 in the second embodiment. In the second embodiment, the first flow path 21a is formed longer than the second flow path 21b so that the first lower end 20a of the first flow path 21a protrudes downward further than the second lower end 20b of the second flow path 21b. That is, when the needle 18 is attached to the injection port 14, the second lower end 20b is located higher in the direction of gravity than the first lower end 20a.

[0042] Fig. 9 is a schematic cross-sectional view illustrating the ink injection operation using the needle 18 of the second embodiment. Fig. 9 shows a state in which the liquid level 23 of the ink injected into the ink tank 8 has reached the first lower end 20a. Because the first flow path 21a is longer than the second flow path 21b, the distance between the first lower end 20a and the bottom surface of the ink tank 8 (ink containing chamber 9) is shorter than the distance between the second lower end 20b and the bottom surface of the ink tank 8 (ink containing chamber 9).

[0043] As the ink injection progresses and the liquid level 23 in the ink tank 8 (ink storage chamber 9) reaches the first lower end 20a, the first lower end 20a is blocked by ink. Therefore, it becomes impossible for the air in the ink tank 8 to flow out to the ink supply container 17 via the first lower end 20a (first flow path 21a). This determines that the first flow path 21a functions as a flow path for ink, and the second flow path 21b functions as a flow path for air.

[0044] In this way, by reducing the distance between the first lower end 20a of the first flow path 21a, which functions as an ink flow path, and the bottom surface of the ink tank 8 (ink storage chamber 9), the determination of the flow path can be further promoted, and the time required for the ink injection operation can be shortened.

[0045] Third Embodiment Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. Note that since the basic configuration of this embodiment is similar to that of the first embodiment, only the characteristic configuration will be described below.

[0046] 10 is a schematic cross-sectional view showing a needle 18 in the third embodiment. In the third embodiment, the first flow path 21a has a tapered shape such that the cross-sectional area of ​​the first flow path 21a increases toward the first lower end 20a. The inside of the first flow path 21a does not have any steps or irregularities like the enlarged portion 22 in the second flow path 21b, and is composed of a smooth surface. In this way, by making the flow path shape smooth such that the cross-sectional area increases from the first upper end 19a toward the first lower end 20a, the flow rate of ink in the first flow path 21a can be further improved.

[0047] [Fourth embodiment] Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings. Note that since the basic configuration of this embodiment is similar to that of the first embodiment, only the characteristic configuration will be described below.

[0048] 11 is a schematic cross-sectional view showing a needle 18 in the fourth embodiment. In the fourth embodiment, a first upper end 19a of a first flow passage 21a is formed higher in the direction of gravity so as to protrude upward than a second upper end 19b of a second flow passage 21b.

[0049] When the needle 18 is inserted into the ink supply container 17 for the ink injection operation, the first upper end 19a protrudes upward compared to the second upper end 19b, so the first upper end 19a comes into contact with the ink contained in the ink supply container 17 before the second upper end 19b does. This makes it easier for ink to flow through the first flow path 21a, further facilitating the establishment of the flow path. [Explanation of symbols]

[0050] 8 Ink Tank 9 Ink chamber 14 Inlet 18 Needle (injection auxiliary part) 19a First upper end 19b Second upper end 20a Section 1 End 20b 2nd lower end 21a First flow path 21b Second flow path 22 Enlarged section 100 Inkjet recording device

Claims

1. a tank having a storage chamber for storing liquid to be supplied to a discharge head that discharges the liquid; a first flow path defined by a first upper end portion opening toward the outside of the storage chamber and a first lower end portion opening toward the inside of the storage chamber, through which liquid flows from a supply container for supplying liquid to the storage chamber to the storage chamber; a second flow path defined by a second upper end portion opening toward the outside of the storage chamber and a second lower end portion opening toward the inside of the storage chamber, through which air flows from the storage chamber to the supply container; The second flow path is characterized in that a step portion in which the cross-sectional area of ​​the second flow path is expanded is formed at a position closer to the second upper end than the second lower end, and a vortex is generated in the step portion, causing a pressure loss, and the second flow path is defined as a flow path through which air flows.

2. The liquid ejection device according to claim 1 , wherein the first upper end portion is open at an angle.

3. 3. The liquid ejection apparatus according to claim 1, wherein the second upper end portion is open at an angle.

4. 4. The liquid ejection device according to claim 1, wherein the first flow path is not formed with a step that increases a cross-sectional area of ​​the first flow path.

5. 5. The liquid ejection device according to claim 1, wherein an opening area of ​​the first upper end portion is larger than an opening area of ​​the second upper end portion.

6. 6. The liquid ejection device according to claim 1, wherein the first flow path and the second flow path are integrally formed.

7. The liquid ejection device according to claim 1 , wherein the first upper end and the second upper end are inserted into the supply container.

8. 8. The liquid ejection device according to claim 1, wherein the first upper end and the second upper end are capped by a tank cap.

9. 9. The liquid ejection device according to claim 1, wherein the tank has a second storage chamber for storing air.

10. The liquid ejection device according to claim 9 , wherein the second storage chamber is disposed above the storage chamber.

11. 11. The liquid ejection device according to claim 9, wherein the tank is provided with an opening for introducing air into the second storage chamber.

12. The liquid ejection device according to claim 1 , further comprising a tube that connects the tank and the ejection head.

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