Liquid dispensing device

Abstract

To provide a technology by which a remaining amount of a liquid such as ink can be detected accurately.SOLUTION: A liquid discharge device includes a liquid discharge head which discharges a liquid to be supplied, storage means which stores the liquid to be supplied to the liquid discharge head, a rotation member which is immersed in the liquid stored in the storage means and can rotate according to a liquid amount, and detection means which detects the liquid amount by using the rotation member. At least one of specific gravity and a size of the rotation member varies depending on specific gravity of the stored liquid.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection apparatus that can be widely used, for example, as an inkjet recording apparatus equipped with a recording head capable of ejecting ink by an inkjet method. [Background technology]

[0002] Patent Document 1 discloses a technology for detecting the amount of ink remaining in a storage chamber by providing a rotatable member with a float in the storage chamber and detecting the rotation of this member with a sensor. The technology disclosed in Patent Document 1 utilizes the buoyancy generated in the float by the stored ink to rotate the rotating member according to the amount of ink remaining. In order to generate buoyancy in the float, the float is designed to have a specific gravity lighter than the specific gravity of the stored ink. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-25818 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in a recording device that ejects multiple types of ink, a storage chamber is provided for each ink, as disclosed in Patent Document 1. The buoyancy generated in the float varies depending on the specific gravity of the ink. Therefore, when multiple types of ink with a higher specific gravity than the float and different specific gravities are used, the buoyancy generated in the float changes depending on the specific gravity of the ink. As a result, the amount of rotation of the rotating member corresponding to the remaining amount of ink varies depending on the type of ink, which may make it impossible to accurately detect the remaining amount of ink.

[0005] The present invention has been made in view of the above-mentioned problems, and has an object to provide a technique that can accurately detect the remaining amount of liquid such as ink. [Means for solving the problem]

[0006] In order to achieve the above object, one embodiment of the present invention comprises: 1st configured to dispense a liquid 1st a liquid ejection head; 1st Supplied to the liquid ejection head , the first Retaining fluid No. 1 and a means for storing the a second liquid ejection head configured to eject a second liquid having a specific gravity greater than that of the first liquid; and second storage means for storing the second liquid, which is supplied to the second liquid ejection head; A liquid ejection device having the 1st Reservoir The step is , and stored The first Immersed in liquid, The first Rotatable according to the amount of liquid 1st A rotating member, 1st The liquid stored in the first storage means is rotated by a rotating member. The first Detecting the amount of liquid 1st a detection means, The second storage means includes a second rotating member that is immersed in the stored second liquid and is rotatable according to the amount of the second liquid, and a second detection means that detects the amount of the second liquid stored in the second storage means using the second rotating member, and the specific gravity of the second rotating member is greater than the specific gravity of the first rotating member. It is characterized by the following features. [Effects of the Invention]

[0007] According to the present invention, the remaining amount of ink can be detected accurately. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram illustrating the configuration of a recording apparatus, which is an example of a liquid ejection apparatus according to an embodiment. [Figure 2] 6A and 6B are diagrams showing the movement of a rotating member when ink is supplied to an ink storage chamber. [Figure 3] 10A and 10B are diagrams showing the movement of the rotating member when the ink stored in the ink storage chamber decreases. [Figure 4] 10A and 10B are diagrams showing the height of the ink liquid surface when the remaining amount of ink with different specific gravities is determined to be a predetermined amount or less. [Figure 5] FIG. 4 is a diagram showing a rotating member for keeping the ink level constant according to the specific gravity of the ink. [Figure 6] 10A and 10B are diagrams showing another embodiment of a rotating member. DETAILED DESCRIPTION OF THE INVENTION

[0009] An example of a liquid ejection device according to the present invention will be described in detail below with reference to the accompanying drawings. Note that 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 solutions of the present invention. Furthermore, unless otherwise specified, the relative positions, shapes, and the like of the components described in the present embodiments are merely examples, and are not intended to limit the scope of the present invention to those alone.

[0010] (First embodiment) First, a liquid ejection apparatus according to a first embodiment will be described with reference to FIGS. 1 to 5. In this specification, a liquid ejection apparatus that ejects ink onto a recording medium to perform recording will be described as an example. FIG. 1 is a diagram for explaining an outline of a recording apparatus according to an embodiment, where (a) is a perspective view of the apparatus's exterior and (b) is a diagram showing the configuration of a recording unit inside the apparatus. Note that the recording apparatus 10 in FIG. 1 is an example of a recording apparatus to which this embodiment can be applied, and recording apparatuses to which this embodiment can be applied are not limited to the recording apparatus 10 shown in FIG. 1.

[0011] The recording device 10 shown in FIG. 1 is a so-called multifunction device that includes a reading unit 12 that can read a document set on a document table, and a recording unit 14 that records information read by the reading unit 12 or information input from an external device onto a recording medium.

[0012] The reading unit 12 is located at the top of the recording device 10, and the recording unit 14 is located at the bottom of the recording device 10. The recording unit 14 includes a storage tray 16 that stores recording media M, a feed roller 18 that feeds the recording media M stored in the storage tray 16, and a guide unit 20 that guides the fed recording media M to a recording position by a recording head 26 (described later). The recording unit 14 also includes a transport roller 22 that transports the recording media M fed via the guide unit 20, a platen 24 that supports the recording media M transported by the transport roller 22, and a recording head 26 that ejects ink onto the recording media M supported by the platen 24. The recording unit 14 also includes a discharge roller 30 that discharges the recorded recording media M to a discharge tray 28, and an ink storage unit 32 as storage means that stores ink to be supplied to the recording head 26 via a tube (not shown).

[0013] The recording head 26 may be capable of ejecting ink of multiple colors, or may be capable of ejecting ink of only one color. It may also be configured to be capable of ejecting treatment liquid for imparting a predetermined effect to the recorded image. When ejecting multiple types of ink (including treatment liquid), multiple ink reservoirs 32 are provided, each storing a different type of ink. The recording head 26 is mounted on a carriage 34. The carriage 34 is configured to be able to move back and forth in the X direction. The recording medium M accommodated in the storage tray 16 is transported in the -Y direction by the feed roller 18, makes a U-turn by the guide unit 20, and is transported in the +Y direction by the transport roller 22.

[0014] In the recording device 10, as the recording head 26 moves in the X direction via the carriage 34, ink is ejected onto the recording medium M supported by the platen 24, performing a recording operation to record one scan's worth of data on the recording medium M. Next, a transport operation is performed in which the recording medium is transported a predetermined distance in the +Y direction, and an area on the recording medium M that has not yet been printed is positioned opposite the recording head 26. After that, the recording operation is performed again. In this way, the recording device 10 records an image on the recording medium M by alternately and repeatedly executing the recording operation and the transport operation.

[0015] FIG. 2 is a schematic diagram of the ink storage section 32, where (a) shows the state in which the ink storage member 36 is not attached to the ink storage chamber 38, and (b) shows the state in which the ink storage member 36 is attached to the ink storage chamber 38.

[0016] The ink storage section 32 includes an ink storage member 36 that stores ink, and an ink storage chamber 38 that stores the ink stored in the ink storage member 36. The ink storage member 36 is configured to be detachable from the ink storage chamber 38. In the recording device 10, when the remaining amount of ink in the ink storage chamber 38 reaches a certain amount, the user replaces the ink storage member 36 with a new one.

[0017] An ink storage section 32 is provided for each type of ink ejected from the recording head 26. The ink storage sections 32 have the same configuration regardless of the type of ink, except for a portion of the configuration of a rotating member 48 (described later). In the ink storage section 32, ink stored in an ink storage chamber 38 is supplied to the recording head 26 via a tube (not shown). When ink is supplied from the ink storage chamber 38 to the recording head 26 and the amount of ink in the ink storage chamber 38 decreases, ink is supplied to the ink storage chamber 38 from the connected ink accommodating member 36.

[0018] The ink storage member 36 comprises a main body 40 and a lid 42. Ink is stored inside the main body 40. A supply unit 44 is provided at the bottom of the main body 40, and is connected to a connecting member 47 (described later) in the ink storage chamber 38 to supply ink to the ink storage chamber 38. That is, in this embodiment, the ink storage member 36 is configured to be detachable from the ink storage chamber 38 via the supply unit 44. The supply unit 44 is equipped with an opening / closing mechanism such as a valve spring structure. An atmosphere communication port 46 is formed in the lid 42, which connects the inside of the ink storage member 36 to the outside.

[0019] The ink storage chamber 38 includes a connecting member 47 that connects to the ink accommodating member 36 via the supply unit 44. A rotating member 48 is provided on the bottom 38a of the ink storage chamber 38. The rotating member 48 is rotatably supported at the bottom 38a by a support member 50. Therefore, when ink is supplied to the ink storage chamber 38, the rotating member 48 is immersed in the ink. A sensor 52 capable of detecting the rotation of the rotating member 48 is provided above the rotating member 48 in the ink storage chamber 38. While the sensor 52 is provided in the ink storage chamber 38, this is not a limitation, and the sensor 52 may be provided separately from the ink storage chamber 38 as long as it is capable of detecting the rotation of the rotating member 48. An air communication port 54 that communicates the interior of the ink storage chamber 38 with the outside is formed in the ink storage chamber 38 at a position not reached by the liquid level of the stored ink.

[0020] The rotating member 48 includes a float 56 extending in the Y direction, an arm 58 extending upward (approximately in the Z direction) from the float 56, and a detectable portion 60 located at the tip of the arm 58. The float 56 is made of a material having a lower specific gravity than the ink contained in the ink containing member 36. The float 56 is rotatably supported on a shaft 62 extending in the X direction on the support member 50 at a lower portion on one side in the extension direction (Y direction). The detectable portion 60 is located above the float 56 via the arm 58. Therefore, the detectable portion 60 is configured to move in response to the rotation of the float 56. The detectable portion 60 is made of a material that can be detected by the sensor 52. As will be described later, in this embodiment, the sensor 52 is an optical sensor including a light-emitting portion and a light-receiving portion, and therefore the detectable portion 60 is made of a material that blocks or attenuates light from the light-emitting portion.

[0021] The sensor 52 is a detection unit that detects the rotation of the rotating member 48 and optically detects whether the ink level stored in the ink storage chamber 38 has fallen below a predetermined level. When the ink level falls below the predetermined level, the recording device 10 determines that the ink stored in the ink storage chamber 38 has fallen below a predetermined level. More specifically, the sensor 52 includes a light-emitting element (not shown) and a light-receiving element (not shown). In FIGS. 2(a) and 2(b), the light-emitting element and the light-receiving element are arranged to face each other with a gap in the X direction. When the rotating member 48 rotates, the detected element 60 passes between the light-emitting element and the light-receiving element. The sensor 52 outputs a different detection signal depending on the light received by the light-receiving element from the light-emitting element.

[0022] Specifically, for example, when the light emitted from the light-emitting element cannot be received by the light-receiving element, that is, when the intensity of the received light is below a predetermined intensity, the sensor 52 outputs a low-level signal indicating that the signal level is below a threshold level. The output low-level signal is received by a control unit (not shown) mounted on a main board (not shown). The control unit that receives the low-level signal detects that the height of the ink liquid surface is above a predetermined level.

[0023] On the other hand, when the light emitted from the light-emitting element can be received by the light-receiving element, that is, when the intensity of the received light is equal to or greater than a predetermined intensity, the sensor 52 outputs a high-level signal indicating that the signal level is equal to or greater than a threshold level. The output high-level signal is received by the control unit, which detects that the height of the ink liquid level is below a predetermined level.

[0024] When the ink storage member 36 is connected via the supply unit 44 to the connection member 47 of the ink storage chamber 38 (see FIG. 2(a)) in a state where no ink is stored, the ink in the ink storage member 36 flows into the ink storage chamber 38 via the supply unit 44 and the connection member 47. When a certain amount of ink is stored in the ink storage chamber 38, the buoyancy acting on the float 56, which has a smaller specific gravity than the ink, overcomes gravity, and the rotating member 48 (float 56) rotates in the direction of arrow A. This rotation of the rotating member 48 in the direction of arrow A moves the detected part 60 in the direction of arrow B.

[0025] When the ink level in the ink storage chamber 38 reaches or exceeds a predetermined level due to further ink inflow, the detected portion 60 moves in the direction of arrow B and is positioned between the light-emitting portion and the light-receiving portion of the sensor 52. The ink level reaching or exceeding the predetermined level in the ink storage chamber 38 means that a predetermined amount of ink is stored in the ink storage chamber 38. While the ink level is at or above the predetermined level, the detected portion 60 remains between the light-emitting portion and the light-receiving portion (see FIG. 2(b)). Thus, when the ink level reaches or exceeds the predetermined level, the light emitted from the light-emitting portion of the detected portion 60 is not received by the light-receiving portion (or is attenuated before reaching the light-receiving portion), and the sensor 52 outputs a low-level signal to the control unit. This allows the control unit to detect that the ink level is at or above the predetermined level.

[0026] Figure 3 is a diagram illustrating the operation of the rotating member 48 when the ink in the ink storage chamber 38 decreases. Figure 3(a) is a diagram illustrating the rotating member 48 when the ink level in the ink storage chamber 38 is above a predetermined level, and Figure 3(b) is a diagram illustrating the rotating member 48 when the ink level in the ink storage chamber 38 is below the predetermined level.

[0027] As ink is supplied from the ink storage chamber 38 to the recording head 26, the ink in the ink storage chamber 38 and the ink accommodating member 36 decreases, causing the ink level in the ink storage chamber 38 to drop (see FIG. 3(a)). When the amount of ink in the ink storage chamber 38 decreases and the stored ink falls below a certain level, gravity overcomes the buoyancy acting on the float 56. This causes the rotating member 48 (float 56) to rotate in the direction of arrow C. This rotation of the rotating member 48 in the direction of arrow C moves the detected portion 60 in the direction of arrow D.

[0028] When the ink level in the ink storage chamber 38 drops below a predetermined level due to further ink supply to the recording head 26, the detected portion 60 moves in the direction of arrow D to a position retracted from between the light-emitting portion and the light-receiving portion of the sensor 52. While the ink level remains below the predetermined level, the detected portion 60 remains in the retracted position from between the light-emitting portion and the light-receiving portion, i.e., remains retracted from the sensor 52 (see FIG. 3(b)). Thus, when the ink level is below the predetermined level, the light emitted from the light-emitting portion by the detected portion 60 can be received by the light-receiving portion (or reaches the light-receiving portion without being attenuated), and the sensor 52 outputs a high-level signal to the control unit. This allows the control unit to detect that the ink level is below the predetermined level.

[0029] Here, when the recording device 10 detects that the ink level has fallen below a predetermined level, a notification is displayed on the display unit 17 (see FIG. 1(a)) provided on the recording device 10, for example, urging the user to replace the ink containing member 36. The user will usually confirm the notification displayed on the display unit 17 and replace the ink containing member 36. However, a small amount of ink still remains in the ink storage chamber 38, and a certain number of sheets can be recorded after detecting that the ink level has fallen below the predetermined level. For this reason, the recording device 10 counts the number of ink droplets ejected from the ink storage chamber 38 after detecting that the ink level has fallen below the predetermined level, and notifies the user that the ink is running out when it becomes difficult to supply ink from the ink storage chamber 38 to the recording head 26.

[0030] In recent years, the types of ink used in recording devices have become more diverse, and a single recording device can be configured to use multiple types of ink. Therefore, if a recording device is configured with multiple ink reservoirs 32 with identical configurations, each for a different type of ink, the specific gravity of the ink will vary depending on the type of ink, resulting in differences in the buoyancy exerted on the float. This could make it impossible to accurately detect when the ink level has fallen below a predetermined level.

[0031] The inability to accurately detect that the ink level has fallen below a predetermined level due to differences in ink specific gravity will be described in detail with reference to FIG. 4. FIG. 4 illustrates the state of the rotating member and the remaining amount of ink when inks of different specific gravities are used. FIG. 4(a) illustrates the state when ink with a specific gravity lower than the reference specific gravity is used, FIG. 4(b) illustrates the state when ink with the reference specific gravity is used, and FIG. 4(c) illustrates the state when ink with a specific gravity higher than the reference specific gravity is used. The rotating member used is a rotating member 48R with a specific gravity that allows accurate detection of the ink level of the ink 400 in the ink storage chamber 38 falling below a predetermined level when the reference ink 400 is used. The rotating member 48R also has a lower specific gravity than ink 402, which has a specific gravity lower than the reference ink 400 by a certain amount.

[0032] When ink 400 with a reference specific gravity is used, when the liquid level Ls of ink 400 in ink storage chamber 38 reaches height hr, detected portion 60 of rotated rotating member 48R is retracted from sensor 52 (see FIG. 4(b)). At this time, recording device 10 detects that the ink liquid level has fallen below a predetermined position. In other words, in this case, when the ink level is at height hr, the buoyancy generated in rotating member 48R is smaller than the gravity acting on rotating member 48R. In the explanation using FIGS. 4 and 5, this is when proper detection is achieved.

[0033] When ink 402 having a lower specific gravity than ink 400 having a reference specific gravity is used, when the liquid level Ls of the ink 402 reaches height hl in the ink storage chamber 38, the detected portion 60 of the rotated rotating member 48R is retracted from the sensor 52 (see FIG. 4A). In other words, when the height hl is higher than height hr, the buoyancy generated on the rotating member 48R (float 56R) is smaller than the gravity acting on the rotating member 48R. Therefore, when the liquid level Ls reaches height hl, the recording device 10 detects that the ink liquid level has fallen below the predetermined position. Here, the specific gravity of the ink 402 is lower than that of the ink 400. Therefore, in the ink storage chamber 38, the buoyancy generated on the rotating member 48R (float 56R) by the ink 402 is smaller than the buoyancy generated on the rotating member 48R by the ink 400. As a result, when the remaining ink amount is greater and the liquid level reaches height hl, the detected part 60 is retracted from the sensor 52.

[0034] When ink 404 having a higher specific gravity than ink 400 having a reference specific gravity is used, when the liquid level Ls of ink 404 reaches height hh in ink storage chamber 38, the detected portion 60 of the rotated rotating member 48R is retracted from sensor 52 (see FIG. 4(c)). In other words, when the liquid level Ls is at height hh, which is lower than height hr, the buoyancy generated on the rotating member 48R is smaller than the gravity acting on the rotating member 48R. Therefore, when the liquid level Ls reaches height hh, recording device 10 detects that the ink liquid level has fallen below the predetermined position. Here, ink 404 has a higher specific gravity than ink 400. Therefore, in ink storage chamber 38, the buoyancy generated on the rotating member 48R by ink 404 is greater than the buoyancy generated on the rotating member 48R by ink 400. As a result, when the remaining amount of ink is low and the liquid level reaches height hh, the detected part 60 is retracted from the sensor 52.

[0035] In this way, when ink storage chambers 38 of the same configuration equipped with rotating member 48R are used for inks of different specific gravities, the liquid level at which it is detected to be below the predetermined level, i.e., the liquid level at which detected portion 60 is retracted from sensor 52, varies depending on the specific gravity of the ink. After issuing a notification urging replacement of ink accommodating member 36, recording device 10 counts the number of ejected ink droplets and notifies the user that the ink container is empty when the count reaches a predetermined number. Therefore, there is a risk that the ink container will run out before the notification that the ink container is empty, or that there may still be an amount of ink available for recording at that time.

[0036] Therefore, in this embodiment, the specific gravity of the rotating member 48, more specifically the specific gravity of the float 56, is changed in accordance with the specific gravity of the ink. This will be explained in detail below with reference to Figure 5. Figure 5 is a diagram illustrating the change in the specific gravity of the float in accordance with the specific gravity of the ink, where (a) shows the case of ink with a lower specific gravity than the reference ink, and (b) shows the case of ink with a higher specific gravity than the reference ink.

[0037] In the ink storage chamber 38 that stores the ink 402 with a low specific gravity, the rotating member 48 uses a rotating member 48L equipped with a float 56L with a low specific gravity (see FIG. 5(a)). The float 56L has a lower specific gravity than the float 56R of the rotating member 48R, which can properly detect when the liquid level of the ink 400, which serves as a reference, falls below a predetermined level. The specific gravity of the float 56L is adjusted to a level that can properly detect when the liquid level of the ink 402 falls below a predetermined level. In other words, the specific gravity of the float 56L is adjusted to a level that causes the detection target 60 to retract from the sensor 52 when the liquid level of the ink 402 reaches a height hr. Specifically, the specific gravity of the float 56L is adjusted so that the difference between the specific gravity of the ink 402 and the specific gravity of the float 56L matches the difference between the specific gravity of the ink 400 and the specific gravity of the float 56R. Note that the difference between the specific gravity of the ink 402 and the specific gravity of the float 56L matching the difference between the specific gravity of the ink 400 and the specific gravity of the float 56R does not necessarily mean that these differences match exactly, but also includes the case where they are within a specified range.

[0038] In the ink storage chamber 38 that stores the ink 404 with a high specific gravity, the rotating member 48 uses a rotating member 48H equipped with a float 56H with a high specific gravity (see FIG. 5(b)). The float 56H has a higher specific gravity than the float 56R of the rotating member 48R, which can properly detect that the ink 400 level has fallen below a predetermined level. The specific gravity of the float 56H is adjusted to a level that can properly detect that the ink 404 level has fallen below a predetermined level. In other words, the specific gravity of the float 56H is adjusted to a level that causes the detection target 60 to retract from the sensor 52 when the ink 404 level reaches a height hr. Specifically, the specific gravity of the float 56H is adjusted so that the difference between the specific gravity of the ink 404 and the specific gravity of the float 56H matches the difference between the specific gravity of the ink 400 and the specific gravity of the float 56R. Note that the difference between the specific gravity of ink 404 and the specific gravity of float 56H matching the difference between the specific gravity of ink 400 and the specific gravity of float 56R does not necessarily mean that these differences match exactly, but also includes the case where they are within a specified range.

[0039] Therefore, when the recording device 10 is configured to use a plurality of inks with different specific gravities, each ink storage chamber 38 is provided with a rotating member 48 equipped with a float 56 whose specific gravity is adjusted according to the specific gravity of the ink stored therein. In this case, in each ink storage chamber 38, the difference between the specific gravity of the ink stored therein and the specific gravity of the float 56 is the same (including within a predetermined range).

[0040] As described above, in the recording device 10, the specific gravity of the float 56 in the rotating member 48 is changed according to the specific gravity of the ink stored in the ink storage chamber 38. This makes it possible to properly detect when the liquid level of the ink stored in the ink storage chamber 38 falls below a predetermined level. Therefore, depending on the type of ink, after issuing a notification urging the user to replace the ink accommodating member 36, it becomes possible to notify the user that the ink has run out at an appropriate timing.

[0041] (Second embodiment) Next, a liquid ejection device according to a second embodiment will be described with reference to Fig. 6. In the following description, a recording device that ejects ink onto a recording medium to record, as in the first embodiment, will be used as an example. Furthermore, the same reference numerals will be used for components that are the same as or equivalent to those in the recording device according to the first embodiment, and detailed descriptions thereof will be omitted where appropriate.

[0042] The liquid ejection device 10 according to the second embodiment differs from the first embodiment in that the size of the float 56 is changed in accordance with the specific gravity of the ink.

[0043] Figure 6 is a diagram explaining how the size of the float changes depending on the specific gravity of the ink, where (a) is for ink with a lower specific gravity than the reference ink, (b) is for the reference ink, and (c) is for ink with a higher specific gravity than the reference ink.

[0044] When ink 400 with a reference specific gravity is used, when the liquid level Ls of ink 400 reaches height hr in ink storage chamber 38, detected portion 60 of rotated rotating member 48R is retracted from sensor 52 (see FIG. 6(b)). At this time, recording device 10 detects that the ink liquid level has fallen below a predetermined position. In other words, when the liquid level is at height hr, the buoyancy generated in rotating member 48R is smaller than the gravity acting on rotating member 48R. In the explanation using FIG. 6, this is when proper detection is achieved.

[0045] In the ink storage chamber 38 that stores the ink 402 with a low specific gravity, a rotating member 48Sm equipped with a small-sized float 56Sm is used as the rotating member 48 (see FIG. 6(a)). The float 56Sm is smaller than the float 56Me of the rotating member 48Me, which can properly detect when the reference ink 400 level falls below a predetermined level. The float 56Sm is also adjusted to a size that can properly detect when the ink 402 level falls below a predetermined level. In other words, the float 56Sm is adjusted to a size that allows the detection target portion 60 to retract from the sensor 52 when the ink 402 level reaches a height hr. Specifically, the size of the float 56Sm is adjusted so that the buoyancy force acting on the float 56Me when the ink 400 level is at height hr matches the buoyancy force acting on the float 56Sm when the ink 402 level is at height hr. Note that the buoyancy force acting on the float 56Me when the ink 400 level is at a height hr and the buoyancy force acting on the float 56Sm when the ink 402 level is at a height hr matching does not necessarily mean that these buoyancies exactly match, but also includes the case where these buoyancies are within a predetermined range.

[0046] In the ink storage chamber 38 that stores the ink 404 with a high specific gravity, a rotating member 48La equipped with a large-sized float 56La is used as the rotating member 48 (see FIG. 6(c)). The float 56La is larger than the float 56Me of the rotating member 48Me, which can properly detect that the ink 400 level has fallen below a predetermined level. The float 56La is also adjusted to a size that can properly detect that the ink 404 level has fallen below a predetermined level. In other words, the float 56La is adjusted to a size that allows the detection target portion 60 to be retracted from the sensor 52 when the ink 404 level reaches a height hr. Specifically, the size of the float 56La is adjusted so that the buoyancy force acting on the float 56Me when the ink 400 level is at height hr matches the buoyancy force acting on the float 56La when the ink 404 level is at height hr. Note that the buoyancy force acting on the float 56Me when the ink 400 level is at a height hr and the buoyancy force acting on the float 56La when the ink 404 level is at a height hr matching does not necessarily mean that these buoyancies exactly match, but also includes the case where these buoyancies are within a predetermined range.

[0047] Therefore, when the recording device 10 is configured to use a plurality of inks with different specific gravities, each ink storage chamber 38 is provided with a rotating member 48 equipped with a float 56 whose size is adjusted according to the specific gravities of the ink stored therein. In this case, the buoyancy acting on the floats 56 in each ink storage chamber 38 is the same (including within a predetermined range).

[0048] As described above, in the recording device 10 according to the second embodiment, the size of the float 56 in the rotating member 48 is changed according to the specific gravity of the ink stored in the ink storage chamber 38. As a result, the recording device 10 according to the second embodiment achieves the same effects as the recording device 10 according to the first embodiment.

[0049] (Other embodiments) The above embodiment may be modified as shown in the following (1) to (4).

[0050] (1) In the above embodiment, the rotatable member 48 is provided in the ink storage chamber 38, but this is not limiting. That is, the rotatable member 48 may be provided in the ink storage member 36. In this case, the sensor 52 is provided so as to be able to detect the rotatable member 48 provided in the ink storage member 36 when the ink storage member 36 is connected to the ink storage chamber 38. In the above embodiment, only one of the specific gravity or size of the float 56 is changed in accordance with the specific gravity of the ink, but this is not limiting. That is, both the specific gravity and size of the float 56 may be changed, or at least one of the specific gravity and size of the float 56 may be changed in accordance with the specific gravity of the ink.

[0051] (2) The above embodiment is not limited to a recording device that ejects ink from a recording head to record on a recording medium, but can be widely applied to a liquid ejection device that ejects various liquids from a liquid ejection head to perform various processes. In addition, in the above embodiment, the recording device 10 is a so-called serial scan type recording device that ejects ink from a recording head moving in the X direction onto a recording medium transported in the Y direction, but is not limited to this. In other words, the recording device may be a so-called full line type recording head that uses a long recording head that spans the entire width of the recording area on the recording medium.

[0052] (3) In the above embodiment, the rotating member 48 and the sensor 52 are used to determine whether the liquid level of the ink stored in the ink storage chamber 38 is below a predetermined level. However, the configuration for detecting the amount of ink in the ink storage chamber 38 is not limited to this. That is, a sensor capable of detecting the rotation angle of the rotating member 48 from a reference position may be used to detect the remaining amount of ink stored in the ink storage chamber 38 in stages or continuously based on the rotation angle of the rotating member 48. Also, although not specifically described in the above embodiment, a recording device configured to eject only a single color of ink uses an ink storage unit 32 that includes a rotating member 48 with a float 56 whose specific gravity corresponds to the specific gravity of the ink to be ejected. Alternatively, an ink storage unit 32 that includes a float 56 whose size corresponds to the specific gravity of the ink may be used.

[0053] (4) The above embodiment and the various configurations shown in (1) and (3) above may be combined as appropriate. [Explanation of symbols]

[0054] 10 Recording Device 26 Recording head 32 Ink reservoir 48 Rotating member 52 sensors

Claims

1. A first liquid ejection head configured to eject a first liquid; a first reservoir for storing the first liquid to be supplied to the first liquid ejection head; a second liquid ejection head configured to eject a second liquid having a specific gravity greater than that of the first liquid; a second reservoir for storing the second liquid to be supplied to the second liquid discharge head, The first storage means includes: a first rotation member that is immersed in the stored first liquid and is rotatable according to the amount of the first liquid; a first detection means for detecting the amount of the first liquid stored in the first storage means using the first rotating member, The second storage means includes: a second rotation member that is immersed in the stored second liquid and is rotatable according to the amount of the second liquid; a second detection means for detecting the amount of the second liquid stored in the second storage means using the second rotating member, A liquid ejection device, wherein the specific gravity of the second rotating member is greater than the specific gravity of the first rotating member.

2. The first rotating member includes: a first float having a specific gravity smaller than that of the first liquid stored in the first storage means and rotatably supported by the first storage means; a first detectable portion that is provided on the first float via an arm portion and that can be detected by the first detecting means; The second rotating member includes: a second float having a specific gravity smaller than that of the second liquid stored in the second storage means and rotatably supported by the second storage means; a second detection target portion that is provided on the second float via an arm portion and that can be detected by the second detection means; 2. The liquid ejection device according to claim 1, wherein the specific gravity of the second float is greater than the specific gravity of the first float.

3. the first detection means detects that the height of the liquid surface of the first liquid stored in the first storage means has fallen below a predetermined level due to rotation of the first rotating member; the specific gravity of the first float is such that, when the liquid level of the first liquid falls below the predetermined position, the first detection means can determine that the liquid level has fallen below the predetermined position; the second detection means detects that the liquid level of the second liquid stored in the second storage means has fallen below the predetermined position due to rotation of the second rotating member; A liquid ejection device as described in claim 2, wherein the specific gravity of the second float is such that when the liquid level of the second liquid falls below the predetermined position, the second detection means can determine that the liquid level has fallen below the predetermined position.

4. A liquid ejection device as described in Claim 3, wherein the difference between the specific gravity of the first liquid in the first storage means and the specific gravity of the first float is the same as the difference between the specific gravity of the second liquid in the second storage means and the specific gravity of the second float.

5. the first storage means includes a first storage chamber that stores the first liquid, and a first storage member that is detachable from the first storage chamber and stores the first liquid to be supplied to the first storage chamber; In the first storage means, by attaching the first storage member to the first storage chamber, the first liquid stored in the first storage member flows into the first storage chamber, the second storage means includes a second storage chamber that stores the second liquid, and a second storage member that is detachable from the second storage chamber and stores the second liquid to be supplied to the second storage chamber; A liquid ejection device described in any one of claims 1 to 4, wherein in the second storage means, the second liquid stored in the second storage member flows into the second storage chamber by attaching the second storage member to the second storage chamber.

6. The first rotating member is provided in the first storage chamber, The liquid ejection device according to claim 5 , wherein the second rotating member is provided in the second storage chamber.

7. the first rotating member is provided in the first storage member, The liquid ejection device according to claim 5 , wherein the second rotating member is provided in the second housing member.

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