Liquid ejection device and method for estimating remaining amount of ejected liquid

Abstract

To appropriately detect a residual quantity of liquid having photosensitivity.SOLUTION: A liquid discharge device for discharging discharge liquid that is photosensitive to light of a first wavelength includes a main tank 1, a film part 13, a sub-tank 2, a piping part 11, ray introduction means, a sensor part 22, and detection means. Inside of the main tank 1 is divided into a first chamber and a second chamber by the film part 13. The first chamber stores the discharge liquid 3. The second chamber stores working fluid 4 containing a coloring component. The film part 13 changes its position according to a residual quantity of the discharge liquid 3. The ray introduction means introduces rays including light of a second wavelength into the main tank 1. The sensor part 22 measures intensity of light included in the rays of the second wavelength transmitting through the working fluid 4. The detection means detects the position of the film part 13 on the basis of the intensity of the light included in the rays of the second wavelength measured by the sensor part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a liquid ejection device and a method for estimating a remaining amount of ejection liquid. [Background technology]

[0002] Patent document 1 discloses a liquid ejection device that uses a film to divide a storage chamber into a first chamber and a second chamber, and can measure the remaining amount of photosensitive ejection liquid stored in the first chamber by having a measuring unit measure the amount of liquid filler supplied from a tank to the second chamber. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-019930 Summary of the Invention [Problem to be solved by the invention]

[0004] In a liquid ejection device that manages the remaining amount of photosensitive ejection liquid, it is necessary to take care to prevent the ejection liquid from being exposed to light. Therefore, an object of the present disclosure is to appropriately detect the remaining amount of photosensitive liquid. [Means for solving the problem]

[0005] Book The liquid ejection device disclosed is a liquid ejection device for ejecting an ejection liquid having a property of being photosensitive to light of a first wavelength, and includes a main tank that contains a working liquid containing a coloring component and the ejection liquid, and a liquid ejection device disposed in the main tank. a first film disposed in the main tank and a second film disposed in the main tank. a film portion that divides the inside of the main tank into a first chamber that contains the discharge liquid and a second chamber that contains the hydraulic fluid, and whose position changes depending on the remaining amount of the discharge liquid; a sub-tank that contains the hydraulic fluid and communicates with the second chamber; The aforementioned Hydraulic fluid The aforementioneda hydraulic fluid supply means for supplying hydraulic fluid into a second chamber; a light beam introducing means for introducing a light beam containing light of a second wavelength different from the first wavelength into the main tank; a sensor unit for measuring the intensity of light contained in the light beam containing light of the second wavelength that has passed through the hydraulic fluid; and a detection means for detecting the position of the film unit based on the intensity of light contained in the light beam containing light of the second wavelength measured by the sensor unit. a reflecting portion disposed in a space between the first film and the second film and reflecting light rays including light of the second wavelength; The present invention is characterized by comprising: [Effects of the Invention]

[0006] According to the liquid ejection device according to the present disclosure, the remaining amount of photosensitive liquid can be detected appropriately. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram of a liquid ejection device. [Figure 2] FIG. 1 is a schematic diagram of a liquid ejection device. [Figure 3] FIG. 1 is a schematic diagram of a liquid ejection device. [Figure 4] FIG. 3 is a schematic diagram showing an example of a reflecting section 16. [Figure 5] Schematic diagram showing the relationship between transmitted light intensity and distance in liquid. [Figure 6] FIG. 1 is a schematic diagram of a liquid ejection device. [Figure 7] FIG. 1 is a schematic diagram of a liquid ejection device. [Figure 8] FIG. 1 is a schematic diagram of a liquid ejection device. [Figure 9] FIG. 1 is a schematic diagram of a liquid ejection device. [Figure 10] FIG. 1 is a schematic diagram of a liquid ejection device. [Figure 11] FIG. 1 is a schematic diagram of a liquid ejection device. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0009] <Embodiment 1> FIG. 1 is a schematic diagram of a liquid ejection device 10 according to this embodiment. As shown in FIG. 1, the liquid ejection device 10 includes a main tank 1 and a sub-tank 2. A second chamber associated with the main tank 1 and the sub-tank 2 are connected to communicate with each other via a piping section 11. Details of the second chamber will be described later. The main tank 1 includes a peripheral wall section 5 that is the peripheral wall of the main tank 1, an ejection section 12, a film section 13, and an optical unit 20. The film section 13 includes a reflecting section 16. The optical unit 20 includes a light source section 21, a sensor section 22, and an optical system 23.

[0010] [About Main Tank 1] The main tank 1 is divided into a first chamber and a second chamber by a film portion 13. The first chamber contains the ejection liquid 3. The ejection liquid 3 has the property of being photosensitive to light of a specific wavelength (so-called photosensitivity). Specifically, the ejection liquid 3 according to this embodiment is a photoresist used in the lithography process of semiconductor devices. The photoresist is photosensitive and solidifies when irradiated with i-line light (light with a wavelength of 365 nm) in the near-ultraviolet region. Therefore, the peripheral wall portion 5 of the main tank 1 is made of a material that is light-blocking at least to light with a wavelength of 365 nm. Note that the film portion 13 does not need to be light-blocking to light with a wavelength of 365 nm.

[0011] Furthermore, if trace amounts of metal ions, impurity particles, etc. are mixed into the discharge liquid 3, this could seriously damage the performance of the semiconductor device manufactured using the discharge liquid 3. For this reason, the liquid-contacting surface of the main tank 1 is manufactured using materials and processing methods that do not contain eluted substances, etc. Hereinafter, trace amounts of metal ions, impurity particles, eluted substances, etc. will be collectively referred to as "particles." The first chamber is equipped with a discharge unit 12 that discharges the discharge liquid 3. Meanwhile, the second chamber contains a working liquid 4. The working liquid 4 is a liquid that is not photosensitive to light with a wavelength of 365 nm and has approximately the same specific gravity as the discharge liquid 3.

[0012] The hydraulic fluid 4 contains at least one of a colorant and an additive that absorbs and / or diffuses the light contained in the light ray L1 (described below) when the light ray L1 passes through the hydraulic fluid 4. In other words, the hydraulic fluid 4 has the property of at least absorbing and / or diffusing the light contained in the light ray L1. For example, in this embodiment, the hydraulic fluid 4 contains a red coloring component. As described above, the main tank 1 is provided with a film portion 13, and is configured to prevent the hydraulic fluid 4 from mixing with the discharge liquid 3. Therefore, there are no restrictions on the substances contained in the hydraulic fluid 4.

[0013] [About Subtank 2] The sub-tank 2 is disposed outside the main tank 1. The sub-tank 2 contains a sub-tank hydraulic fluid 7 therein. The sub-tank hydraulic fluid 7 and the hydraulic fluid 4 are contained in different tanks, but have the same components. The sub-tank hydraulic fluid 7 is supplied to the second chamber via a piping section 11, which serves as a hydraulic fluid supply means. The liquid level of the sub-tank hydraulic fluid 7 is controlled by a liquid level control means (not shown) so that it is positioned several millimeters to several tens of millimeters lower in the direction of gravity than the discharge section 12.

[0014] [Relationship between the volumes of the discharged liquid 3 and the working liquid 4] The discharge unit 12 is equipped with a liquid discharge means (not shown). The liquid discharge means can perform control to forcibly discharge the discharge liquid 3. When the discharge unit 12 discharges the discharge liquid 3 and the remaining amount of the discharge liquid 3 in the main tank decreases, the position of the film portion 13 changes and the volume of the working liquid 4 in the second chamber increases. At this time, when the working liquid 4 is replenished from the sub-tank 2 to the second chamber, the liquid level of the working liquid 7 in the sub-tank drops. However, a liquid level control means (not shown) replenishes the working liquid 7 in the sub-tank 2 from the outside so that the liquid level of the working liquid 7 in the sub-tank can be maintained at a constant height.

[0015] [About pressure control] The discharge part 12 is provided with a plurality of openings with diameters of several μm to several tens of μm, and even if the internal pressure of the discharge liquid 3 is equal to atmospheric pressure, the possibility of the discharge liquid 3 freely leaking from the discharge part 12 due to so-called capillary action is low. In this embodiment, the internal pressure of the first chamber is maintained at a negative pressure, so the main tank 1 is configured to further reduce the possibility of the discharge liquid 3 leaking from the discharge part 12. As described above, the discharge liquid 3 and the hydraulic fluid 4 have approximately the same specific gravity, and the wall surface of the film part 13 is freely displaceable, so the internal pressures of the first chamber and the second chamber are equal.

[0016] Furthermore, because the internal pressure of the second chamber becomes negative relative to atmospheric pressure due to the head difference between the discharge portion 12 and the liquid level of the working fluid 7 in the sub-tank, the internal pressure of the first chamber also becomes negative relative to atmospheric pressure. In the liquid discharge device 10 according to the present disclosure, the height difference between the discharge portion 12 and the liquid level of the working fluid 7 in the sub-tank is controlled to be 41±4 mm. The internal pressures of the first and second chambers are controlled to be 0.40±0.01 kPa lower than atmospheric pressure.

[0017] [About Film Section 13] The film portion 13 is flexible and functions as a partition that divides the inside of the main tank 1 into a first chamber and a second chamber. The position of the film portion 13 changes within the main tank 1 depending on the remaining amount of the discharged liquid 3. FIG. 2 is a schematic diagram showing an example of the position of the film portion 13 when the remaining amount of the discharged liquid 3 is large. FIG. 3 is a schematic diagram showing an example of the position of the film portion 13 when the remaining amount of the discharged liquid 3 is small. As shown in FIGS. 1 to 3, the optical unit 20 is provided on the second chamber side of the peripheral wall portion 5.

[0018] 2, when the remaining amount of the discharged liquid 3 is large, the film portion 13 is located near the optical unit 20. On the other hand, when the remaining amount of the discharged liquid 3 is small, the film portion 13 is located at a location far from the optical unit 20, as shown in FIG.

[0019] As the discharge liquid 3 is discharged from the discharge portion 12 and the remaining amount of the discharge liquid 3 decreases, the film portion 13 is displaced in a direction away from the optical unit 20, as shown in Fig. 3. That is, when the remaining amount of the discharge liquid 3 is almost full, the film portion 13 is located at the position shown in Fig. 2. When the remaining amount of the discharge liquid 3 is about two-thirds, the film portion 13 is located at the position shown in Fig. 1. Furthermore, when the remaining amount of the discharge liquid 3 is almost empty, the film portion 13 is located at the position shown in Fig. 3.

[0020] In addition, in order to prevent particles such as metal ions and impurities from eluting into the discharge liquid 3, fluororesins such as PFA and PTFE are used for the film portion 13. Note that the above-mentioned "PFA" is an abbreviation for "Perfluoro alkoxy alkane." And the above-mentioned "PTFE" is an abbreviation for "Poly tetra fluoro ethylene." Also, for the same reason, the film portion 13 is rigorously washed.

[0021] Furthermore, in order to maintain the internal pressures of the first and second chambers in an equilibrium state, both at 0.40 kPa lower than atmospheric pressure, it is preferable that the deformation resistance generated when the film portion 13 deforms be 0.01 kPa or less. Therefore, the thickness of the film portion 13 is configured to be 100 μm or less. In other words, the film portion 13 is a thin film made of fluororesin and has a thickness of 100 μm or less. Therefore, the film portion 13 is highly transparent and does not have a high light-blocking ability against light with a wavelength of 365 nm.

[0022] [Regarding the reflector 16] In this embodiment, a reflecting portion 16 is provided on the surface of the film portion 13. In this embodiment, the reflecting portion 16 is configured to reflect light ray L1, which is emitted from the light source portion 21 and guided into the second compartment of the main tank 1 via the optical system 23, toward the optical system 23 with a reflectance of 80% or more. Note that hereinafter, the light ray emitted by the light source portion 21 will be simply referred to as the "light ray," and the light ray guided into the second compartment of the main tank 1 via the optical system 23 will be referred to as the "light ray L1."

[0023] An example of the reflecting section 16 will be described using FIG. 4. FIG. 4 is a schematic diagram showing an example of the reflecting section 16. The reflecting section 16 includes a base layer 67, a reflecting layer 62, a focal layer 63, a glass sphere 61, and a surface layer 64. Furthermore, L65 in the figure indicates the incident light of light ray L1. L66 indicates the reflected light of light ray L1. In FIG. 4, the back surface of the base layer 67 is bonded to the above-mentioned film section 13. In other words, the back surface of the base layer 67 is the bonding surface that bonds to the above-mentioned film section 13.

[0024] On the other hand, a plurality of recesses recessed toward the bonding surface are formed at regular intervals on the surface opposite to the bonding surface of the base layer 67. A reflective layer 62 is formed along the recesses, which reflects incident light L65 with a high reflectance of 90% or more regardless of wavelength in the visible range of white light.

[0025] Furthermore, a focal layer 63 is formed on the reflective layer 62 along the recesses. Furthermore, glass spheres 61 are arranged on the focal layer 63 as a means for refracting the light ray L1. The reflective layer 62 has recesses and is formed on the surface of the base layer 67 at regular intervals, so the glass spheres 61 arranged on the focal layer 63 are also arranged at regular intervals. Furthermore, the surface layer 64 is transparent. The surface layer 64 is bonded to the surface of the base layer 67 so as to sandwich the glass spheres 61. By sandwiching the glass spheres 61 between the base layer 67 and the surface layer 64, displacement of the glass spheres 61 and damage to the surface of the glass spheres 61 are prevented.

[0026] 4, when incident light L65 is incident on surface layer 64 at an arbitrary incident angle, it is refracted by glass sphere 61 and then strikes reflective layer 62. When incident light L65 strikes reflective layer 62, it is reflected by reflective layer 62 and refracted again by glass sphere 61 to travel back in the direction of light source unit 21 as reflected light L66 parallel to incident light L65.

[0027] Furthermore, in FIG. 4, the incident light L65 and the reflected light L66 appear to be spaced apart even though they are parallel. However, the diameter of the glass sphere 61 is approximately several tens of μm to 100 μm. Therefore, the space can be considered negligible. Therefore, even if the film unit 13 cannot maintain a perpendicular angle to the light ray L1, the light ray L1 guided through the optical system 23 returns to the optical system 23 following almost the same optical path. The sensor unit 22 can then receive the returned light ray L1. Of course, FIG. 4 is merely one example of the reflecting unit 16. For example, another example of the reflecting unit 16 is a reflector that utilizes retroreflection by a so-called corner cube.

[0028] [About light source unit 21] The light source unit 21 is disposed on the second chamber side of the peripheral wall portion 5. The light source unit 21 has a function of irradiating light rays having a predetermined wavelength toward the inside of the second chamber of the main tank 1. In the present embodiment, the light source unit 21 irradiates light rays including light of a first wavelength, which is a wavelength to which the ejection liquid 3 is photosensitive, and the following description will be continued.

[0029] For example, a white light source can be used as the light source unit 21 according to this embodiment. In this case, the white light emitted by the white light source contains light of 365 nm, which is the wavelength to which the ejection liquid 3 is photosensitive.

[0030] [About Optical System 23] The optical system 23 according to this embodiment is a light ray introduction means having the function of blocking light rays emitted from the light source unit 21 and introducing them into the second chamber of the main tank 1. Specifically, the optical system 23 according to this embodiment is coated with a light-blocking film that blocks light with a wavelength of 400 nm or less. This is to prevent the discharge liquid 3 from being exposed to white light containing light of the above-mentioned first wavelength when it passes through the film unit 13 and reaches the discharge liquid 3.

[0031] Basically, in this embodiment, as described above, the reflecting unit 16 is configured to reflect the light ray L1 that has passed through the second chamber toward the optical system 23. However, there is a risk that the light ray L1 will reach the first chamber if the light ray L1 is misaligned or the position of the film unit 13 changes due to an installation error or the like. However, by providing the above-described light-shielding film, even if the light ray L1 reaches the first chamber, it is possible to prevent the discharge liquid 3 from being exposed to light.

[0032] The light-shielding film blocks light of the first wavelength, and the optical system 23 according to this embodiment guides light of a second wavelength, which is different from the first wavelength and does not photosensitize the ejection liquid 3, into the second chamber of the main tank 1. The optical system 23 also has a function of guiding the light ray L1 reflected from the reflecting unit 16 to the sensor unit 22, which will be described later.

[0033] [Sensor unit 22] The sensor unit 22 has a function of acquiring an image of the light ray L1 described above. For example, in this embodiment, a CCD camera is used as the sensor unit 22, so that the sensor unit 22 can receive a color image of the light ray L1 reflected by the reflecting unit 16.

[0034] The sensor unit 22 also has a function of measuring the intensity of the light beam L1 after it has passed through the working fluid, based on the acquired image of the light beam L1. That is, the sensor unit 22 detects the intensity of the light beam L1 after it has passed through the working fluid and been attenuated.

[0035] [About the optical path of light rays] The optical path from when the light source unit 21 emits a light beam until when the light beam L1 enters the sensor unit 22 will be described below.

[0036] First, in this embodiment, as described above, the white light source emits white light rays containing light of a first wavelength. Then, when the white light rays enter the optical system 23, the light-shielding film blocks light of 400 nm or less. As a result, the white light rays become light of a second wavelength (i.e., light ray L1) and are guided into the second chamber. When light ray L1 is guided into the second chamber, it passes through the working fluid 4 contained in the second chamber toward the position of the film portion 13.

[0037] When the light ray L1 reaches the film unit 13, the light ray L1 is reflected by the reflecting unit 16 provided in the film unit 13 and travels back along the optical path along which it traveled. In other words, when the light ray L1 hits the reflecting unit 16, it is transmitted from the reflecting unit 16 toward the optical system 23.

[0038] In this embodiment, the working fluid 4 contains a red coloring component, and therefore, when the light ray L1 passes through the working fluid 4, the light contained in the light ray L1 is attenuated or diffused in the working fluid 4. That is, when the light ray L1 is guided into the second chamber via the optical system 23, the light ray L1 passes through the working fluid 4 to the reflecting unit 16 while being attenuated. Then, when the light ray L1 is reflected by the reflecting unit 16, it returns to the optical system 23 again while being further attenuated.

[0039] When the light ray L1 returns to the optical system 23, the light ray L1 is again guided to the sensor unit 22 via the optical system 23. The sensor unit 22 receives a color image of the light ray L1 and detects the intensity of the light ray L1.

[0040] In other words, when the light ray L1 passes through the working fluid 4, the light contained in the light ray L1 is attenuated within the working fluid 4, and when the sensor unit 22 receives a color image of the light ray L1, a change in the hue of the light ray L1 is received, and the intensity of the light ray L1 is detected.

[0041] [About the processing section] The liquid ejection device 10 includes a processing unit (not shown), which converts the color image of the light beam L1 acquired by the sensor unit 22 into RGB values.

[0042] [About storage devices] The liquid ejection device 10 includes a storage device (not shown), which has the function of storing the above-mentioned RGB values.

[0043] In the liquid ejection device 10 according to this embodiment, the distance of the light ray L1 passing through the working liquid 4 and the change in the value obtained by dividing the value of the B component by the value of the R component when the light after passing through the working liquid 4 is received and converted into an RGB value are stored in advance in the storage device as reference data. In other words, the storage device stores the change in the ratio of the B component to the R component.

[0044] [Relationship between transmitted light intensity and distance through liquid] FIG. 5 is a schematic diagram showing the relationship between the intensity of transmitted light when light ray L1 passes through the working fluid 4 and the distance traveled by light ray L1 through the working fluid 4. In other words, the correlation data shown in FIG. 5 previously provides a correlation between the intensity of transmitted light when light ray L1 passes through the working fluid 4 and the distance traveled by light ray L1 through the working fluid 4. Hereinafter, the distance traveled by light ray L1 through the working fluid 4 is referred to as the "internal fluid distance." When the working fluid 4 is colored red, blue light, which is the complementary color of red, is attenuated by at least one of absorption and diffusion. Therefore, the transmitted light amount 72 of blue light decreases as the internal fluid distance increases. On the other hand, the transmitted light amount 71 of red light remains almost constant even when the internal fluid distance increases.

[0045] When the image obtained by the sensor unit 22 is converted into RGB values, the amount of blue transmitted light 72 indicates the B component of the RGB values. On the other hand, the amount of red transmitted light 71 indicates the R component of the RGB values. When the image of a white light source is converted directly into RGB values, the three RGB components will have approximately the same value, for example (188, 191, 196), although this will vary depending on the light intensity.

[0046] When the film unit 13 is in close contact with the peripheral wall 5 on the optical system 23 side (see FIG. 2), the light ray L1 hardly passes through the working fluid 4. Therefore, as described above, the RGB values ​​of the image obtained by the sensor unit 22 have three components with approximately the same value. As the reflecting unit 16 moves away from the optical system 23 and the distance that the light ray L1 passes through the working fluid 4 increases (see FIGS. 1 and 3), the value representing the B component in the RGB values ​​decreases.

[0047] In this embodiment, the distance traveled through the working fluid 4 can be calculated by dividing the value of the B component by the value of the R component from the results obtained from the RBG values ​​of the image of the light ray L1 received by the sensor unit 22 and comparing the result with the reference data.

[0048] In this embodiment, light ray L1 passes through twice the distance from optical system 23 to reflector 16, and therefore half the calculated in-liquid distance is the distance from optical system 23 to reflector 16. Reflector 16 is fixed to film unit 13. Therefore, the calculated distance is equal to the distance from optical system 23 to film unit 13. In other words, if the distance from optical system 23 to reflector 16 can be calculated, the position of film unit 13 can be detected.

[0049] As described above, the B component decreases in the RGB values ​​obtained from light transmitted through the red-colored working fluid 4, so it is possible to simply focus on the B component, obtain the state of change as reference data, and compare it with the data actually obtained on the liquid ejection device 10.

[0050] However, the intensity of the white light source may change due to changes in the power supply to the light source unit 21, changes over time in the light source unit 21 itself, etc. The intensity of the R component hardly changes depending on the transmission distance in the working fluid 4, but the value changes in proportion to the intensity of the white light source. On the other hand, the value of the B component changes in proportion to the intensity of the white light source before being introduced into the working fluid 4, and then the value changes by being multiplied by attenuation due to the transmission distance in the working fluid 4.

[0051] For this reason, it is preferable to use the data on the ratio of the R component, which changes little even when the distance in the liquid increases, to the B component as the reference. This makes it possible to prevent a decrease in detection accuracy due to disturbances.

[0052] [summary] With the above configuration, the liquid ejection device 10 according to this embodiment can detect the position of the film portion 13 without exposing the ejection liquid 3 to light. Then, if the relationship between the distance from the optical system 23 to the reflecting portion 16 (i.e., the position information of the film portion 13) and the volume of the working liquid 4 remaining in the second chamber is previously associated, the volume of the working liquid 4 can be estimated.

[0053] Furthermore, by previously associating the remaining amount of the ejection liquid 3 in the first chamber with the remaining amount of the working liquid 4 in the second chamber, it is possible to estimate the remaining amount of the ejection liquid 3. In other words, if the remaining amount of the working liquid 4 can be calculated, it is possible to automatically detect the remaining amount of the ejection liquid 3. In other words, the liquid ejection device 10 of the present disclosure can appropriately detect the remaining amount of the photosensitive liquid.

[0054] <Embodiment 2> Hereinafter, the second embodiment will be described with reference to the drawings. The object of this embodiment is to more accurately and appropriately detect the remaining amount of ejection liquid 3. FIG. 6 is a schematic diagram of a liquid ejection device 10 according to this embodiment. The difference between the liquid ejection device 10 according to the first embodiment and the liquid ejection device 10 according to this embodiment is the number of optical units 20. In the following description, the same reference numerals are used to designate configurations that are similar to or correspond to those of the first embodiment, and a description thereof will be omitted, with the differences being mainly described.

[0055] As described above, the film portion 13 is a thin film. Therefore, it has a high degree of freedom of displacement, and there is a possibility that a location other than the irradiation position of the light beam L1 may be deformed. Therefore, there may be a case where the correlation between the detected position of the film portion 13 and the volume of the hydraulic fluid 4 is not high. Therefore, in this embodiment, a plurality of optical units 20 is provided to suppress errors in position detection of the film portion 13.

[0056] 6, in this embodiment, a plurality of optical units 20 are arranged side by side on the peripheral wall 5 of the main tank 1 that forms the second chamber. Specifically, the first optical unit 20a according to this embodiment includes a first sensor 22a corresponding to the first light source 21a. The second optical unit 20b includes a second sensor 22b corresponding to the second light source 21b. The third optical unit 20c includes a third sensor 22c corresponding to the third light source 21c.

[0057] In this embodiment, each light beam emitted from each light source passes through the working fluid 4 and is reflected by the reflecting portion 16. Then, each reflected light beam is received by a corresponding sensor corresponding to each light source, and an image of the reflected light is captured.

[0058] According to the liquid ejection device 10 of this embodiment, the distance from the optical unit 20 to the film portion 13 is detected at multiple locations, so even if the film portion 13 is locally deformed, it is possible to accurately calculate the volume of the working liquid 4. In other words, according to the liquid ejection device 10 of this embodiment, it is possible to more accurately and appropriately detect the remaining amount of the ejection liquid 3.

[0059] 6, there is one reflecting portion 16, but a plurality of reflecting portions 16 may be arranged within a range capable of reflecting light rays emitted from each light source. The number of optical units 20 is not limited to three. The number of optical units 20 may be two, four or more, as long as it is within the limit of the number that can be arranged on the peripheral wall portion 5.

[0060] <Embodiment 3> A third embodiment will be described below. The purpose of this embodiment is to appropriately detect the remaining amount of ejection liquid 3 with a simpler configuration. The liquid ejection device 10 according to this embodiment differs from the liquid ejection device 10 according to the first embodiment in the configuration of the optical unit 20 and the method of calculating the distance from the optical system 23 to the reflecting section 16. In the following description, configurations similar to or corresponding to those of the first embodiment are given the same reference numerals and description will be omitted, with the differences being mainly described.

[0061] First, the difference between the optical unit 20 according to the first embodiment and the optical unit 20 according to this embodiment will be described.

[0062] The light source unit 21 according to the first embodiment includes a white light source and emits light rays including light of a first wavelength that photosensitizes the ejection liquid 3. In contrast, the light source unit 21 according to the present embodiment includes a light source that emits light rays including light of a second wavelength that is different from the light of the first wavelength, and a light source that emits light rays including light of a third wavelength that is different from the first wavelength and the second wavelength and that does not photosensitize the ejection liquid 3. Specifically, the light source unit 21 according to the present embodiment includes a blue LED that emits light rays with a central wavelength of 460 nm and a red LED that emits light rays with a central wavelength of 660 nm.

[0063] In the first embodiment, the relationship between the transmitted light intensity and the distance in the liquid at transmitted light amount 71 of red light, and the relationship between the transmitted light intensity and the distance in the liquid at transmitted light amount 72 of blue light were described using Fig. 5. In this embodiment, with reference to Fig. 5, transmitted light amount 71 of red light corresponds to the transmitted light amount of 660 nm red light. Meanwhile, transmitted light amount 72 of blue light corresponds to the transmitted light amount of 460 nm blue light.

[0064] The working fluid 4 according to this embodiment contains a red coloring component, as in the first embodiment. Therefore, the light irradiated by the blue LED (hereinafter, the light irradiated is referred to as "blue light") is attenuated when passing through the working fluid 4. On the other hand, the light irradiated by the red LED (hereinafter, the light irradiated is referred to as "red light") reaches the sensor unit 22 with almost no attenuation even when passing through the working fluid 4.

[0065] The sensor unit 22 according to this embodiment receives a color image of “blue light” and a color image of “red light.” Furthermore, the optical system 23 according to this embodiment does not necessarily need to be coated with a light-shielding film that blocks light with a wavelength of 400 nm or less.

[0066] The above is the difference between the optical unit 20 according to the first embodiment and the optical unit 20 according to this embodiment.

[0067] Next, a description will be given of the difference between the method of calculating the distance from the optical system 23 to the reflecting unit 16 according to the first embodiment and the method of calculating the distance from the optical system 23 to the reflecting unit 16 according to this embodiment. In the first embodiment, there is a step of converting the color image of the light ray L1 received by the sensor unit 22 into RGB values, and obtaining a value by dividing the B component value in the RGB values ​​by the R component value.

[0068] In contrast, this embodiment differs from embodiment 1 in that the above-mentioned conversion step can be omitted. In this embodiment, it is sufficient to simply calculate the value obtained by dividing the amount of received "blue light" by the amount of received "red light."

[0069] In this embodiment, as in the first embodiment, the correlation between the rate at which the light intensity of the blue LED and the light intensity of the red LED are attenuated by passing through the working fluid 4 that has been colored red in advance and the distance that the light passes through the working fluid 4 is stored in a storage device as reference data.

[0070] Then, by comparing the actual measurement value obtained by the above calculation with the reference data, it is possible to calculate the in-liquid distance of the actually transmitted light ray L1 according to this embodiment. Half of the in-liquid distance obtained by this calculation is equal to the distance from the optical system 23 to the film unit 13.

[0071] As a result, the light source unit 21 according to this embodiment does not emit light rays containing light with a wavelength of 360 nm, and therefore, even if the ejection liquid 3 is irradiated with "blue light rays" or "red light rays," the possibility that the ejection liquid 3 will be photosensitive and solidify can be reduced. Also, as described above, the light source unit 21 according to this embodiment does not require the optical system 23 to be coated with a light-blocking film. Furthermore, the method of calculating the distance from the optical system 23 to the reflecting unit 16 can also be simplified. Therefore, according to the liquid ejection device 10 according to this embodiment, the remaining amount of the ejection liquid 3 can be appropriately detected with a simpler configuration.

[0072] <Embodiment 4> In the first embodiment, the film portion 13 includes one film. In the fourth embodiment, an example will be described in which the film portion 13 includes a plurality of films. According to the liquid ejection device 10 of this embodiment, even if a part of the film portion 13 is damaged, it is possible to prevent particles from being mixed into the ejected liquid 3. This embodiment will be described below with reference to the drawings. FIG. 7 is a schematic diagram of the liquid ejection device 10 of this embodiment.

[0073] The liquid ejection device 10 according to this embodiment differs from the liquid ejection device 10 according to embodiment 1 in the configuration of the film section 13. The position of the reflecting section 16 is also different from that of the liquid ejection device 10 according to embodiment 1. In the following explanation, the same reference numerals are used to designate configurations that are similar to or correspond to those of embodiment 1, and explanations will be omitted, with the differences being mainly described.

[0074] The film unit 13 according to this embodiment includes a first film 13a and a second film 13b. That is, the film unit 13 according to this embodiment is composed of two thin films. The second film 13b is a thin film similar to that of the first embodiment, and has a high transmittance of the light ray L1.

[0075] Furthermore, the reflecting portion 16 according to this embodiment is located in the space 15 between the first film 13a and the second film 13b. That is, the reflecting portion 16 is sandwiched between the first film 13a and the second film 13b. Therefore, the light ray L1 is reflected by the reflecting portion 16 after transmitting through the second film 13b, and travels back along the original optical path toward the location of the optical system 23.

[0076] Furthermore, the film unit 13 according to this embodiment is provided with a negative pressure control means (not shown) in the space 15 between the first film 13a and the second film 13b. This is to appropriately change the position of the film unit 13. If two thin films were simply arranged, even if the liquid level of the hydraulic fluid 4 in the subtank 2 were adjusted to create a negative pressure in the second chamber, only the second film 13b would be displaced, and the first chamber would not become negative pressure.

[0077] The negative pressure control means sets the space to a pressure of -10 kPa, which is even more negative than the internal pressure in the second chamber. This allows the film unit 13 to appropriately change position, making it possible to appropriately control the negative pressure in the first and second chambers as described in embodiment 1. Furthermore, since the reflecting unit 16 according to this embodiment is sandwiched between the first film 13a and the second film 13b, it does not come into contact with either the discharged liquid 3 or the working liquid 4. Therefore, regardless of the material that constitutes the reflecting unit 16, there is a low possibility that the discharged liquid 3 and the working liquid 4 will be contaminated.

[0078] Even if the material of the reflecting portion 16 is one that easily deteriorates the working liquid 4 or the working liquid 4 is one that easily deteriorates the reflecting portion 16, this does not pose a problem according to this embodiment because the reflecting portion 16 does not come into contact with the working liquid 4. In other words, in this embodiment, the reflecting portion 16 may be one that easily deteriorates the working liquid 4, or the working liquid 4 may be one that easily deteriorates the reflecting portion 16.

[0079] As a result, the liquid ejection device 10 according to this embodiment can prevent particles from mixing into the ejection liquid 3 even if either the first film 13a or the second film 13b is damaged. Of course, the liquid ejection device 10 according to this embodiment can also prevent particles from mixing into the working liquid 4.

[0080] Furthermore, it is possible to detect the loss of film portion 13 by detecting the liquid that has leaked from the defective portion of film portion 13 by sucking it out of main tank 1. This suction mechanism may also function as a negative pressure control means.

[0081] <Embodiment 5> Hereinafter, a fifth embodiment will be described with reference to the drawings. A liquid ejection device 10 according to this embodiment can detect the remaining amount of ejection liquid 3 more accurately. FIG. 8 is a schematic diagram of the liquid ejection device 10 according to this embodiment. The liquid ejection device 10 according to the first embodiment and the liquid ejection device 10 according to this embodiment differ in the configuration of the optical unit 20.

[0082] The optical unit 20 according to this embodiment includes a light source section 21, an optical system 23, and a sensor section 22. The sensor section 22 includes a first sensor 22a and a second sensor 22b. In the following description, the same reference numerals are used to designate configurations that are similar to or correspond to those in the first embodiment, and descriptions thereof will be omitted, with differences being mainly described.

[0083] First, differences in the light source unit 21 will be described. As described above, the light source unit 21 according to the first embodiment emits white light. In contrast, the light source unit 21 according to the present embodiment emits light L5 having a central wavelength of 460 nm and having circularly polarized properties. Furthermore, light L5 contains a P-polarized component and an S-polarized component.

[0084] Next, the configuration of the optical system 23 according to this embodiment will be described. The optical system 23 according to this embodiment includes a semi-transmitting film and a λ / 4 polarizing plate. The semi-transmitting film reflects S-polarized light with an incident angle of 45 degrees for light with a wavelength of 460 nm. The semi-transmitting film transmits P-polarized light with an incident angle of 45 degrees for light with a wavelength of 460 nm. In other words, the optical system 23 according to this embodiment is a so-called beam splitter.

[0085] Therefore, the optical system 23 of this embodiment separates the light into two light beams with different polarization characteristics, and guides one of the light beams to the second sensor 22b without transmitting it through the main tank 1, and guides the other light beam to the second chamber within the main tank 1.

[0086] As a result, in this embodiment, the S-polarized component of the circularly polarized light beam L5 emitted by the light source unit 21 is reflected by the semi-transmissive film, takes an optical path downward in the figure, and the light amount is detected by the second sensor 22b. In other words, the second sensor 22b detects the intensity of the S-polarized light. On the other hand, the P-polarized component of the light beam L5 emitted by the light source unit 21 passes through the semi-transmissive film and then has its phase converted by the λ / 4 polarizing plate. The P-polarized component of the light beam L5 passes through the optical path of the light beam L5 and is attenuated in the working fluid 4 before passing through the reflecting unit 16. When the light beam L5 is reflected by the reflecting unit 16, it travels back along the optical path of the light beam L5 and enters the optical system 23 again.

[0087] When light ray L5 enters optical system 23, it is converted into S-polarized light again via the λ / 4 polarizing plate, and the light path is directed upward in the figure by the semi-transparent film, where the amount of light is detected by first sensor 22a. That is, first sensor 22a detects the intensity of the S-polarized light. With the above configuration, even if the amount of light ray L5 changes due to a change in the power supply and / or a change over time in light source unit 21, the irradiation intensities of the S-polarized light and the P-polarized light change equally.

[0088] Therefore, if the light quantity obtained by the second sensor 22b is used as the reference light quantity and the ratio of the light quantity obtained by the sensor unit 22 is used as the test light quantity, there is no influence from changes in the light source unit 21. Therefore, it is possible to accurately measure the state of attenuation of the light quantity due to transmission through the working liquid 4. Therefore, the liquid discharge device 10 according to this embodiment can more accurately detect the remaining amount of discharge liquid 3.

[0089] <Embodiment 6> Hereinafter, a sixth embodiment will be described with reference to the drawings. The present embodiment aims to detect the remaining amount of ejection liquid 3 more accurately. FIG. 9 is a schematic diagram of a liquid ejection device 10 according to this embodiment. The liquid ejection device 10 according to the first embodiment differs from the liquid ejection device 10 according to this embodiment in the presence or absence of a spring 14 as a biasing means. In the following description, the same reference numerals will be used to designate configurations that are similar to or correspond to those of the first embodiment, and a description will be omitted, with the differences being mainly described.

[0090] In the first embodiment, the reflecting section 16 is provided on the flexible film section 13, and therefore the angle of incidence of the light ray L1 may not be kept constant. In contrast, the reflecting section 16 according to the present embodiment is bonded to both the film section 13 and the spring 14.

[0091] Reflection section 16 is attached at multiple positions to the wall surface inside peripheral wall section 5 by springs 14. Reflection section 16 is installed so as to move parallel to the wall surface (left and right direction in FIG. 9).

[0092] Therefore, in this embodiment, it is possible to maintain a constant angle of incidence of the light ray L1 with respect to the reflecting section 16. Therefore, according to the liquid ejecting device 10 of this embodiment, it is possible to detect the remaining amount of ejection liquid 3 without using a reflective film with a special structure on the reflecting section 16, for example, as shown in FIG.

[0093] Therefore, according to the liquid ejection device 10 of this embodiment, even when a reflecting mirror with a simple structure is used, the remaining amount of ejection liquid 3 can be detected more accurately.

[0094] 9 shows an example in which optical unit 20 includes two light sources and two sensors, such as first light source 21a, second light source 21b, first sensor 22a, and second sensor 22b, but the number of light sources and sensors is not limited to 2. Also, while an example in which film unit 13 includes first film 13a and second film 13b is shown, the number of films may be one.

[0095] <Embodiment 7> Next, a seventh embodiment will be described with reference to the drawings. The present embodiment aims to detect the remaining amount of ejection liquid 3 with a simpler configuration. FIG. 10 is a schematic diagram of a liquid ejection device 10 according to this embodiment. The liquid ejection device 10 according to this embodiment differs from the liquid ejection device 10 according to the first embodiment in the presence or absence of a reflecting section 16 and the configuration of the optical unit 20. In the following description, the same reference numerals are used to designate configurations that are similar to or correspond to those of the first embodiment, and a description thereof will be omitted, with the differences being mainly described.

[0096] [Differences in Reflector 16] First, we will explain the difference between the presence and absence of the reflecting section 16. The liquid ejecting device 10 according to the first embodiment is provided with the reflecting section 16. In contrast, the liquid ejecting device 10 according to the present embodiment is not provided with the reflecting section 16.

[0097] [Differences in Optical Unit 20] Next, the optical unit 20 according to this embodiment will be described. The optical unit 20 according to the first embodiment includes a light source unit 21, a sensor unit 22, and an optical system 23. In contrast, the optical unit 20 according to this embodiment includes the light source unit 21 and the sensor unit 22, but does not include the optical system 23.

[0098] In addition, in the first embodiment, the optical unit 20 is disposed on the second chamber side. That is, in the first embodiment, the light source unit 21, the sensor unit 22, and the optical system 23 are disposed on the second chamber side. In contrast, in the present embodiment, the light source unit 21 and the sensor unit 22 are disposed opposite each other with the film unit 13 interposed therebetween. That is, in the present embodiment, the light source unit 21 is located on the first chamber side, and the sensor unit 22 is located on the second chamber side.

[0099] In addition, in the first embodiment, the light-shielding film is provided in the optical system 23. In contrast to this, in the present embodiment, the irradiation port of the light source unit 21 is coated with a light-shielding film that blocks light with a wavelength of 400 nm or less. As a result, in the present embodiment, the light-shielding film coated on the irradiation port of the light source unit 21 blocks light with a wavelength of 400 nm or less, and light with a wavelength exceeding 400 nm is irradiated into the main tank 1 as light ray L7.

[0100] [Regarding position detection of film section 13] In this embodiment, the light ray L7 is hardly attenuated when it passes through the discharge liquid 3 in the first chamber. On the other hand, when the light ray L7 passes through the working fluid 4 in the second chamber, the red wavelength light is not attenuated, but the blue wavelength light is attenuated according to the transmission distance.

[0101] Furthermore, the image obtained by sensor unit 22 is converted into RGB values, and the value of the B component in the RGB values ​​is divided by the value of the R component, and the result is compared with reference data. This makes it possible to calculate the distance in the liquid that light ray L7 has traveled, and the process of detecting the position of film unit 13 is basically the same as in embodiment 1. However, the following describes the differences between this embodiment and embodiment 1.

[0102] In this embodiment, the light ray L7 does not travel back and forth through the working fluid 4. Therefore, the transmission distance is half that of the first embodiment, and the attenuation rate of the light is small. Therefore, the accuracy of estimating the position of the film portion 13 is lower than that of the first embodiment.

[0103] However, even when the light ray L7 is incident on the tilted film portion 13, the optical path of the light ray L7 will be a straight line unless there is a large difference in the refractive index between the discharge liquid 3 and the working fluid 4. In other words, the light ray L7 travels straight without being refracted by the film portion 13.

[0104] Therefore, according to this embodiment, the position of the film portion 13 can be estimated without providing the above-mentioned reflecting portion 16. In other words, according to the liquid ejection device 10 according to this embodiment, the remaining amount of ejection liquid 3 can be detected with a simpler configuration. Of course, in Figure 10, the positions of the light source portion 21 and the sensor portion 22 may be reversed.

[0105] <Embodiment 8> Embodiment 8 will be described with reference to the drawings. According to the liquid ejection device 10 of this embodiment, the accuracy of position detection in the film portion 13 can be improved.

[0106] 11 is a schematic diagram of a liquid ejection device 10 according to this embodiment. In the following description, the same reference numerals are used to designate components similar to or corresponding to those in embodiment 1, and a description thereof will be omitted, with the focus being on the differences. The difference between this embodiment and embodiments 1 and 7 is the position of the reflecting section 16.

[0107] The configuration of the reflector 16 according to this embodiment will be described. The reflector 16 according to embodiment 1 is provided on the surface of the film portion 13. In contrast, the reflector 16 according to this embodiment is provided on the wall surface inside the peripheral wall portion 5. Specifically, in this embodiment, the reflector 16 is provided inside the peripheral wall of the first chamber.

[0108] The light ray L1 guided into the main tank 1 via the optical system 23 passes through the second chamber, the film section 13, and the first chamber, and is then reflected by the reflecting section 16 attached to the wall surface inside the first chamber and inside the peripheral wall section 5.

[0109] The light ray L1 reflected by the reflecting portion 16 travels back along the optical path of the light ray L1 and is again detected by the sensor portion 22 via the optical system 23. Therefore, the sensor portion 22 simultaneously receives the blue light that has been attenuated in the working fluid 4 and the red light that is hardly attenuated in the working fluid 4.

[0110] According to the liquid discharge device 10 of this embodiment, the reflecting portion 16 can be attached with high precision because it is provided on the wall surface inside the peripheral wall portion 5. This makes it possible to accurately detect the position of the film portion 13 by performing calculations based on the results of receiving the light ray L1 reflected by the reflecting portion 16.

[0111] <Other embodiments> Although preferred embodiments of the present disclosure have been described, the liquid ejection device 10 according to the present disclosure is not limited to these embodiments, and various modifications and variations are possible within the scope of the present disclosure. For example, if the working liquid 4 is colored blue instead of red, blue light will hardly attenuate according to the transmission distance through the working liquid 4, but red light will be attenuated. The above modifications in accordance with the essence of the present disclosure do not preclude this. Modifications of each embodiment will be described.

[0112] <Modification of the second embodiment> In the second embodiment, an example has been shown in which a plurality of optical units 20 according to the first embodiment are arranged on the peripheral wall 5, but a plurality of optical units 20 according to the third embodiment may be arranged on the peripheral wall 5. For example, a plurality of optical units 20 each including a light source unit 21 including a blue LED that irradiates light having a central wavelength of 460 nm and a red LED that irradiates light having a central wavelength of 660 nm, and a sensor unit 22 may be arranged on the peripheral wall 5.

[0113] Furthermore, a plurality of optical units 20 each including the beam splitter according to the fifth embodiment may be arranged on the peripheral wall 5.

[0114] Furthermore, as in embodiment 7, a plurality of light source units 21 each having the above-mentioned light-shielding film at the irradiation port may be arranged on the peripheral wall 5, and a plurality of sensor units 22 corresponding to each light source unit 21 may be arranged on the peripheral wall 5 so as to face each other across the film unit 13.

[0115] Furthermore, as in embodiment 8, a reflecting section 16 may be provided inside the peripheral wall of the first chamber, and a plurality of optical units 20 may be arranged on the peripheral wall on the second chamber side. Of course, a reflecting section 16 may be provided inside the peripheral wall of the second chamber, and a plurality of optical units 20 may be arranged on the peripheral wall on the first chamber side.

[0116] In addition, in embodiment 2, when the wavelength of light associated with each light beam emitted from each light source is the first wavelength described above, the light of the first wavelength is blocked, as in embodiment 1. On the other hand, when the wavelength of light associated with each light beam emitted from each light source is the second wavelength described above, it is not necessary to block the light.

[0117] <Modification of the Third Embodiment> A modification of the third embodiment may be combined with the film unit 13 of the fourth embodiment. That is, when the blue LED and the red LED according to the third embodiment are used as the light source unit 21, the reflector 16 according to the fourth embodiment, which is disposed in the space 15 between the first film 13a and the second film 13b, may be used.

[0118] Furthermore, when using the spring 14 as in the sixth embodiment, the blue LED according to the third embodiment and the red LED may be used as the light source unit 21.

[0119] Furthermore, when the light source unit 21 and the sensor unit 22 are arranged opposite each other with the film unit 13 sandwiched therebetween as in embodiment 7, the blue LED and the red LED according to embodiment 3 may be used as the light source unit 21.

[0120] Furthermore, when the reflecting section 16 is provided inside the peripheral wall of the first chamber as in the eighth embodiment, the blue LED according to the third embodiment and the red LED may be used as the light source section 21.

[0121] <Modification of the fourth embodiment> A modification of the fourth embodiment is a combination with the optical unit 20 of the second embodiment. That is, when a plurality of optical units 20 are arranged on the peripheral wall portion 5 as in the second embodiment, the reflecting portion 16 may be arranged in the space 15 between the first film 13a and the second film 13b as in the fourth embodiment.

[0122] Furthermore, when a beam splitter is used as the optical unit 20 as in the fifth embodiment, the reflecting portion 16 may be disposed in the space 15 between the first film 13a and the second film 13b as in the fourth embodiment.

[0123] Furthermore, when spring 14 is used as in embodiment 6, reflecting portion 16 may be disposed in space 15 between first film 13a and second film 13b as in embodiment 4. In this case, the surface of second film 13b is bonded to spring 14.

[0124] <Modification of the fifth embodiment> As a modification of the fifth embodiment, there is an example in which it is combined with the spring 14 of the sixth embodiment. For example, when the spring 14 is used as in the sixth embodiment, the optical unit 20 may be configured as the beam splitter according to the fifth embodiment.

[0125] Furthermore, when the reflecting section 16 is provided inside the peripheral wall of the first chamber as in the eighth embodiment, the optical unit 20 may be configured as the beam splitter according to the fifth embodiment.

[0126] <Modification of the Sixth Embodiment> A modification of the sixth embodiment is to combine it with the optical unit 20 of the second embodiment. For example, when the spring 14 is used as in the sixth embodiment, a plurality of optical units 20 may be arranged on the peripheral wall 5.

[0127] <Modifications of the light blocking means> In the first embodiment, an example has been described in which the optical system 23 is coated with a light-shielding film that blocks light of 400 nm or less. As another example, the light-shielding film may be coated on the irradiation port of the light source unit 21 according to the first embodiment. Of course, as described above, the light-shielding film may be coated on the irradiation port of the light source unit 21 according to the second embodiment. Furthermore, the light-shielding film may be coated on the irradiation port of the light source unit 21 according to the fourth, fifth, sixth, and eighth embodiments. Note that when the light-shielding film is coated on the irradiation port of the light source unit 21, the optical system 23 does not need to include the light-shielding film.

[0128] In the seventh embodiment, an example has been described in which the liquid ejection device 10 according to the seventh embodiment does not include the optical system 23, and the above-mentioned light-blocking film is coated on the irradiation port of the light source unit 21. As another example, there is a configuration in which the liquid ejection device 10 according to the seventh embodiment includes the optical system 23, and the optical system 23 is coated with a light-blocking film. [Explanation of symbols]

[0129] 1. Main Tank 10 Liquid dispensing device 13 Film Section 22 Sensor section

Claims

1. A liquid ejection device for ejecting an ejection liquid having a property of being photosensitive to light of a first wavelength, a main tank for accommodating a working fluid containing a coloring component and the discharge fluid; a film portion including a first film disposed in the main tank and a second film disposed in the main tank, the film portion dividing the inside of the main tank into a first chamber that accommodates the discharge liquid and a second chamber that accommodates the hydraulic fluid, and the film portion changing its position depending on the remaining amount of the discharge liquid; a sub-tank containing the hydraulic fluid and communicating with the second chamber; a hydraulic fluid supply means for supplying the hydraulic fluid in the sub-tank into the second chamber; a light beam introducing means for introducing a light beam containing light of a second wavelength different from the first wavelength into the main tank; a sensor unit that measures the intensity of light included in a light beam that includes light of the second wavelength and that has passed through the working fluid; a detection means for detecting the position of the film portion based on the intensity of light contained in the light beam including the light of the second wavelength measured by the sensor portion; a reflecting portion disposed in a space between the first film and the second film and configured to reflect light rays including light of the second wavelength; Equipped with A liquid ejection device characterized by:

2. A negative pressure control means is provided to create a negative pressure in the space. The liquid ejection device according to claim 1 .

3. The light beam introduction means a second light source that emits light rays including light of the second wavelength; a third light source that emits a light beam including light of a third wavelength different from both the light of the first wavelength and the light of the second wavelength, the sensor unit detects an intensity of light having the second wavelength included in a light beam emitted by the second light source and an intensity of light having the third wavelength included in a light beam emitted by the third light source; the detecting means detects the position of the film unit based on the intensity of the light of the second wavelength and the intensity of the light of the third wavelength measured by the sensor unit. The liquid ejection device according to claim 1 or 2.

4. The light beam introduction means a light source that emits a light beam including light of the second wavelength; The light beam emitted by the light source is separated into first polarized light and second polarized light, each having different polarization characteristics, and the first polarized light is guided to the sensor unit without being transmitted through the main tank, and the second polarized light is guided into the main tank, The sensor unit a first sensor that measures the intensity of the first polarized light; a second sensor that measures the intensity of the second polarized light; the amount of light obtained by the first sensor is defined as a reference amount of light, and the ratio of the amount of light obtained by the first sensor and the amount of light obtained by the second sensor is defined as an inspection amount of light, and the position of the film portion is detected using this amount of light. The liquid ejection device according to claim 1 .

5. The liquid ejection device a plurality of optical units each including the light beam introducing means and the sensor unit are provided on a peripheral wall of the second chamber; The liquid ejection device according to claim 1 .

6. The detecting means performs the detection based on correlation data obtained by measuring in advance the distance that the light beam has passed through the hydraulic fluid and the intensity of the light beam. The liquid ejection device according to claim 1 .

7. The intensity of the light beam is a ratio of two of the RGB components contained in the image received by the sensor unit. The liquid ejection device according to claim 6 .

8. The liquid ejection device further includes an estimation unit, the estimation means estimates the remaining amount of the ejection liquid in the first chamber based on the position of the film portion detected by the detection means. The liquid ejection device according to claim 6 or 7.

9. a colorant and / or an additive is added to the hydraulic fluid, the colorant and / or additive absorbing and / or diffusing the light of the second wavelength when the light of the second wavelength is transmitted through the hydraulic fluid; The liquid ejection device according to claim 1 .

10. the working liquid has a property of absorbing and / or diffusing light of the second wavelength; The liquid ejection device according to claim 1 .

11. A liquid ejection device for ejecting an ejection liquid having a property of being photosensitive to light of a first wavelength, a main tank for accommodating a working fluid containing a coloring component and the discharge fluid; a film portion disposed in the main tank, dividing the inside of the main tank into a first chamber containing the discharge liquid and a second chamber containing the hydraulic fluid, and the film portion being capable of changing its position depending on the remaining amount of the discharge liquid; a sub-tank containing the hydraulic fluid and communicating with the second chamber; a hydraulic fluid supply means for supplying the hydraulic fluid in the sub-tank into the second chamber; a light beam introducing means for introducing a light beam containing light of a second wavelength different from the first wavelength into the main tank; a sensor unit that measures the intensity of light included in a light beam that includes light of the second wavelength and that has passed through the working fluid; a detection means for detecting the position of the film portion based on the intensity of light contained in the light beam including the light of the second wavelength measured by the sensor portion; Equipped with The light beam introduction means a first light source that emits a light beam including light of the first wavelength; a light blocking means for blocking the light of the first wavelength emitted from the first light source; a first optical system that guides light rays that are blocked by the light blocking means and that include light of the second wavelength into the main tank, A liquid ejection device characterized by:

12. A method for estimating a remaining amount of ejection liquid in a liquid ejection device, the method comprising: introducing means for introducing a light beam containing light of a second wavelength different from a first wavelength; image receiving means; position detecting means; estimating means; a main tank containing an ejection liquid that is photosensitive when exposed to a light beam containing light of the first wavelength and a working liquid containing a coloring component; and a film portion that divides the inside of the main tank into a first chamber that contains the ejection liquid and a second chamber that contains the working liquid, the introducing means introducing a light beam including light of the second wavelength into the main tank; an image receiving step in which the image receiving means receives an image of the light beam including the light of the second wavelength that has passed through the hydraulic fluid; a detecting step in which the position detecting means detects the position of the film portion based on the intensity of the light of the second wavelength in the image received in the image receiving step; an estimation step in which the estimation means estimates the remaining amount of the ejection liquid based on the position of the film portion detected in the detection step; Including, A method for estimating a remaining amount of ejection liquid, comprising:

Images