Liquid discharge apparatus and liquid containing apparatus

Abstract

The invention relates to a liquid ejecting apparatus and a liquid containing apparatus. A liquid discharge device is characterized by comprising: a storage container for storing a conductive liquid; a first electrode housed in the first liquid chamber of the housing container; a second electrode housed in the second liquid chamber of the housing container; a partition plate housed in the housing container and dividing the first liquid chamber and the second liquid chamber; a detection unit electrically connected to the first electrode and the second electrode and outputting a detection signal corresponding to an electric signal from one of the first electrode and the second electrode; and a determination unit that determines the remaining amount of the liquid contained in the containing container on the basis of the detection signal, a first opening that communicates the first liquid chamber and the second liquid chamber is formed below the partition plate, a second opening that communicates the first liquid chamber and the second liquid chamber is formed above the partition plate, and when the liquid contained in the containing container is present in the first opening and the second opening, the remaining amount of the liquid contained in the containing container is determined. The first electrode and the second electrode are in contact with the liquid stored in the storage container.

Description

Technical Field

[0001] The present invention relates to a liquid ejection device and a liquid storage device. Background Art

[0002] Regarding techniques for detecting the remaining amount of a liquid in a storage container that stores a conductive liquid such as ink, various proposals have been made. For example, in Patent Document 1, a technique is proposed in which the remaining amount of the liquid in the storage container is detected based on the impedance value between two rod-shaped electrode pins provided in the storage container that stores the liquid.

[0003] Patent Document 1: Japanese Patent Laid-Open No. 6-270410

[0004] However, in the existing technique, since the change amount of the impedance value between the two electrode pins is smaller than the change amount of the remaining amount of the liquid in the storage container, there are cases where it is difficult to detect the remaining amount of the liquid in the storage container. Summary of the Invention

[0005] In order to solve the above problems, a liquid ejection device according to the present invention is characterized by including: a storage container that stores a conductive liquid; a first electrode housed in a first liquid chamber of the storage container; a second electrode housed in a second liquid chamber of the storage container; a partition housed in the storage container and partitioning the first liquid chamber and the second liquid chamber; a detection unit electrically connected to the first electrode and the second electrode and outputting a detection signal corresponding to an electrical signal from one of the first electrode and the second electrode; and a determination unit that determines the remaining amount of the liquid stored in the storage container based on the detection signal. A first opening that connects the first liquid chamber and the second liquid chamber is formed below the partition, and a second opening that connects the first liquid chamber and the second liquid chamber is formed above the partition. When there is a liquid stored in the storage container in the first opening and the second opening, the first electrode and the second electrode come into contact with the liquid stored in the storage container.

[0006] In addition, the liquid storage device according to the present invention is characterized by comprising: a storage container for storing a conductive liquid; a first electrode housed in a first liquid chamber of the storage container; a second electrode housed in a second liquid chamber of the storage container; a partition plate housed in the storage container and partitioning the first liquid chamber and the second liquid chamber; and a detection unit electrically connected to the first electrode and the second electrode and outputting a detection signal corresponding to an electrical signal from one of the first electrode and the second electrode. A first opening communicating the first liquid chamber and the second liquid chamber is formed below the partition plate, and a second opening communicating the first liquid chamber and the second liquid chamber is formed above the partition plate. When there is liquid stored in the storage container in the first opening and the second opening, the first electrode and the second electrode are in contact with the liquid stored in the storage container. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 FIG. 1 is a configuration diagram showing an example of an inkjet printer 100 according to an embodiment of the present invention.

[0008] Figure 2 FIG. 2 is a perspective view showing an example of the configuration of the ink storage device 1.

[0009] Figure 3 FIG. 3 is a circuit diagram showing an example of the configuration of the ink storage device 1.

[0010] Figure 4 FIG. 4 is an explanatory diagram showing an example of the configuration of the ink tank TK.

[0011] Figure 5 FIG. 5 is an explanatory diagram showing an example of the configuration of the ink tank TK.

[0012] Figure 6 FIG. 6 is a circuit diagram showing an example of the configuration of the ink storage device 1W according to a reference example.

[0013] Figure 7 FIG. 7 is an explanatory diagram showing an example of the relationship between the ink liquid level distance SZ and the ink impedance RG.

[0014] Figure 8 FIG. 8 is an explanatory diagram showing an example of the relationship between the ink liquid level distance SZ and the output signal Vout.

[0015] Figure 9 FIG. 9 is an explanatory diagram showing an example of the temperature change of the impedance value change curve CR.

[0016] Figure 10 FIG. 10 is an explanatory diagram showing an example of the temperature change of the potential change curve CV.

[0017] Figure 11A circuit diagram showing an example of the configuration of the ink storage device 1Q according to Modification 1.

[0018] Figure 12 A timing chart showing an example of the operation of the ink amount detection circuit 2Q.

[0019] Explanation of reference numerals

[0020] 1: Ink storage device; 2: Ink amount detection circuit; 8: Control device; 20: Output circuit; 100: Inkjet printer; BK: Electrode rod; BT: Electrode rod; OP1: Lower opening; OP2: Upper opening; RM1: Ink liquid chamber; RM2: Ink liquid chamber; TK: Ink tank; WL: Partition. Detailed implementation manners

[0021] Hereinafter, the manner for implementing the present invention will be described with reference to the drawings. However, in each drawing, the dimensions and scales of each part are appropriately different from the actual ones. In addition, the implementation manners described below are preferred specific examples of the present invention, and thus various technically preferred limitations are added. However, regarding the present invention, as long as there is no particular intention to limit the present invention in the following description, it is not limited to these manners.

[0022] A. Embodiment

[0023] Hereinafter, the inkjet printer 100 according to the present embodiment will be described.

[0024] 1. Outline of the inkjet printer

[0025] Figure 1 An explanatory diagram showing an example of the configuration of the inkjet printer 100 according to the present embodiment.

[0026] The inkjet printer 100 is an inkjet printing device that ejects ink IK onto a medium PP. Typically, the medium PP is printing paper, but any printing object such as a resin film or cloth can be used as the medium PP. In the present embodiment, conductive ink is used as the ink IK.

[0027] It should be noted that, in the present embodiment, the inkjet printer 100 is an example of a "liquid ejection device", and the ink IK is an example of a "conductive liquid".

[0028] As Figure 1 shown, the inkjet printer 100 includes an ink storage device 1, a control device 8, a plurality of liquid ejection heads HU, a conveying mechanism 91, and a moving mechanism 92.

[0029] The control device 8 includes, for example, a processing circuit such as a CPU or an FPGA and a storage circuit such as a semiconductor memory, and controls each element of the inkjet printer 100. Here, CPU is an abbreviation for Central Processing Unit, and FPGA is an abbreviation for Field Programmable Gate Array.

[0030] Based on the control of the control device 8, the conveyance mechanism 91 conveys the medium PP in the sub-scanning direction MP1.

[0031] Based on the control of the control device 8, the moving mechanism 92 reciprocates the plurality of liquid ejection heads HU in the main scanning direction MH1 intersecting the sub-scanning direction MP1 and the main scanning direction MH2 opposite to the main scanning direction MH1. The moving mechanism 92 includes a storage box 921 that houses the plurality of liquid ejection heads HU and an endless belt 922 to which the storage box 921 is fixed. It should be noted that the storage box 921 may also house the ink storage device 1 together with the liquid ejection head HU.

[0032] The control device 8 supplies a drive signal Com for driving the liquid ejection head HU and a control signal SI for controlling the liquid ejection head HU to the liquid ejection head HU.

[0033] Based on the control of the control signal SI, the liquid ejection head HU is driven by the drive signal Com, and ink IK is ejected from some or all of the plurality of nozzles provided in the liquid ejection head HU. That is, the liquid ejection head HU ejects ink IK from some or all of the plurality of nozzles in conjunction with the conveyance mechanism 91 conveying the medium PP and the moving mechanism 92 reciprocating the liquid ejection head HU, so that the ejected ink lands on the surface of the medium PP, thereby forming a desired image on the surface of the medium PP.

[0034] The ink storage device 1 stores the ink IK. In addition, based on the control of the control device 8, the ink storage device 1 supplies the ink IK stored in the ink storage device 1 to the liquid ejection head HU.

[0035] It should be noted that, in the present embodiment, the ink storage device 1 is an example of a "liquid storage device".

[0036] In the present embodiment, it is assumed that the ink storage device 1 stores M types of ink IK. Here, the value M is a natural number satisfying 1 ≤ M. More specifically, in the present embodiment, as an example, it is assumed that the ink storage device 1 stores ink IK corresponding to four types of ink: cyan, magenta, yellow, and black. That is, in the present embodiment, as an example, it is assumed that "M = 4".

[0037] In the present embodiment, it is assumed that the inkjet printer 100 includes M liquid ejection heads HU corresponding to M types of inks IK. Specifically, in the present embodiment, as an example, it is assumed that the inkjet printer 100 includes four liquid ejection heads HU corresponding to four types of inks IK.

[0038] It should be noted that hereinafter, the m-th liquid ejection head HU among the M liquid ejection heads HU may be referred to as the liquid ejection head HU[m]. Here, the variable m is a natural number satisfying 1 ≤ m ≤ M.

[0039] The ink storage device 1 includes an ink amount detection circuit 2 that detects the remaining amounts of various inks IK stored in the ink storage device 1 and outputs an output signal Vout indicating the detection result. It should be noted that the ink amount detection circuit 2 will be described later in Figure 3 described.

[0040] It should be noted that in the present embodiment, the output signal Vout is an example of a "detection signal".

[0041] 2. Ink Storage Device

[0042] The following refers to Figures 2 to 7 to describe the outline of the ink storage device 1.

[0043] Figure 2 is a perspective view showing an example of the configuration of the ink storage device 1.

[0044] As Figure 2 shown, the ink storage device 1 includes M ink tanks TK corresponding one-to-one to the M types of inks IK stored in the ink storage device 1 and a storage box 11 that houses the M ink tanks TK. Specifically, in the present embodiment, the ink storage device 1 includes four ink tanks TK corresponding one-to-one to four types of inks IK: cyan, magenta, yellow, and black.

[0045] It should be noted that in the present embodiment, the ink tank TK is an example of a "storage container".

[0046] Hereinafter, the m-th ink tank TK among the M ink tanks TK may be referred to as the ink tank TK[m]. The ink tank TK[m] stores the ink IK corresponding to the type of the ink tank TK[m] and supplies the ink IK to the liquid ejection head HU[m] corresponding to the ink tank TK[m].

[0047] In the present embodiment, a supply port 12 for supplying the ink IK to the internal space of the ink tank TK is provided in the ink tank TK. In addition, an electrode rod BT and an electrode rod BK, which are rod-shaped electrodes, and a partition wall WL for partitioning the internal space of the ink tank TK are housed in the ink tank TK.

[0048] It should be noted that in the present embodiment, the electrode rod BT is an example of the "first electrode", and the electrode rod BK is an example of the "second electrode".

[0049] Hereinafter, when the ink IK stored in the ink tank TK is reduced while the ink IK is supplied from the ink tank TK to the liquid ejection head HU, the direction in which the ink IK is reduced in the ink tank TK is referred to as the Z1 direction. In the present embodiment, as an example, it is assumed that the electrode rod BT and the electrode rod BK are arranged to extend in the Z1 direction in the ink tank TK. It should be noted that hereinafter, the Z1 direction and the Z2 direction opposite to the Z1 direction are collectively referred to as the Z-axis direction.

[0050] It should be noted that in the present embodiment, the Z1 direction is an example of "downward", and the Z2 direction is an example of "upward".

[0051] Figure 3 A circuit diagram showing an example of the configuration of the ink storage device 1. It should be noted that in the present embodiment, it is assumed that M ink amount detection circuits 2 corresponding to M ink tanks TK[1] to TK[M] are provided in the ink storage device 1.

[0052] It should be noted that in the present embodiment, the ink amount detection circuit 2 is an example of the "detection unit".

[0053] As Figure 3 shown, the ink amount detection circuit 2 includes an output circuit 20, an input terminal TnN, a detection terminal TnK, a reference potential connection terminal TnT, and an output terminal TnS.

[0054] The output circuit 20 includes a node NK and an input impedance RN provided between the input terminal TnN and the node NK.

[0055] The node NK is electrically connected to the input terminal TnN, the detection terminal TnK, and the output terminal TnS. The detection terminal TnK is electrically connected to the electrode rod BK via a detection wiring LK. The reference potential connection terminal TnT is electrically connected to a ground wiring set to a ground potential, and is also electrically connected to the electrode rod BT via a reference potential connection wiring LT.

[0056] As described above, the electrode rod BT, the electrode rod BK, and the partition plate WL are accommodated in the ink tank TK. The partition plate WL divides the internal space for accommodating the ink IK in the ink tank TK into an ink liquid chamber RM1 and an ink liquid chamber RM2. The electrode rod BT is accommodated in the ink liquid chamber RM1. The electrode rod BK is accommodated in the ink liquid chamber RM2. In the Z1 direction of the partition plate WL, a lower opening OP1 for communicating the ink liquid chamber RM1 with the ink liquid chamber RM2 is formed. In the Z2 direction of the partition plate WL, an upper opening OP2 for communicating the ink liquid chamber RM1 with the ink liquid chamber RM2 is formed.

[0057] It should be noted that in the present embodiment, the ink liquid chamber RM1 is an example of the "first liquid chamber", the ink liquid chamber RM2 is an example of the "second liquid chamber", the lower opening OP1 is an example of the "first opening", and the upper opening OP2 is an example of the "second opening".

[0058] In the present embodiment, when the ink IK is accommodated in the ink tank TK and the electrode rod BT and the electrode rod BK are in contact with the ink IK accommodated in the ink tank TK, the electrode rod BT and the electrode rod BK are electrically connected via the ink IK accommodated in the ink tank TK. Hereinafter, when the electrode rod BT and the electrode rod BK are electrically connected via the ink IK existing in the lower opening OP1 in the ink IK accommodated in the ink tank TK, the resistance of the ink IK that electrically connects the electrode rod BT and the electrode rod BK through the path via the lower opening OP1 is referred to as the ink impedance RT1. In addition, hereinafter, when the electrode rod BT and the electrode rod BK are electrically connected via the ink IK existing in the upper opening OP2 in the ink IK accommodated in the ink tank TK, the resistance of the ink IK that electrically connects the electrode rod BT and the electrode rod BK through the path via the upper opening OP2 is referred to as the ink impedance RT2.

[0059] In the present embodiment, an input signal Vin having an input potential VN set to be constant is input to the input terminal TnN. Therefore, when the electrode rod BT and the electrode rod BK are electrically connected via the ink IK accommodated in the ink tank TK, the potential of the node NK is determined based on the input potential VN of the input signal Vin, the impedance value of the input impedance RN, and the impedance value of the combined impedance of the ink impedance RT1 and the ink impedance RT2. In the present embodiment, since the input potential VN and the impedance value of the input impedance RN of the input signal Vin are constant values, the potential of the node NK is determined based on the impedance value of the combined impedance of the ink impedance RT1 and the ink impedance RT2. And an output signal Vout representing the potential of the node NK is output from the output terminal TnS.

[0060] In the present embodiment, the control device 8 determines the remaining amount of the ink IK accommodated in the ink tank TK based on the output signal Vout output from the output circuit 20.

[0061] Note that, in the present embodiment, the control device 8 is an example of a "determination unit".

[0062] Figure 4 and Figure 5 is a configuration diagram showing an example of the configuration of the ink tank TK.

[0063] As Figure 4 and Figure 5 shown, an electrode rod BT is accommodated in the ink tank TK. The electrode rod BT is made of a conductive material and is electrically connected to a reference potential connection wiring LT in the upper surface TU of the ink tank TK. Further, the electrode rod BT is arranged such that the distance from the end portion in the Z1 direction of the electrode rod BT to the bottom surface TM of the ink tank TK in the Z-axis direction is a distance H1.

[0064] As Figure 4 and Figure 5 shown, an electrode rod BK is accommodated in the ink tank TK. The electrode rod BK is made of a conductive material and is electrically connected to a detection wiring LK in the upper surface TU of the ink tank TK. Further, the electrode rod BK is arranged such that the distance from the end portion in the Z1 direction of the electrode rod BK to the bottom surface TM of the ink tank TK in the Z-axis direction is a distance H1.

[0065] As Figure 4 and Figure 5 shown, a partition WL is accommodated in the ink tank TK. The partition WL is made of an insulating material. However, the partition WL may also be formed of a conductive substance having an impedance value per unit volume higher than that of the ink IK.

[0066] In the present embodiment, as an example, it is assumed that the partition WL is arranged such that the distance from the end portion in the Z1 direction of the partition WL to the bottom surface TM of the ink tank TK in the Z-axis direction is a distance HE, and further, the distance from the end portion in the Z2 direction of the partition WL to the bottom surface TM of the ink tank TK in the Z-axis direction is a distance H2. That is, in the present embodiment, as an example, it is assumed that the partition WL is arranged such that the lower opening OP1 extends in the range from the bottom surface TM to a distance HE in the Z-axis direction, and the upper opening OP2 extends in the range from the bottom surface TM to a distance HF from the distance H2 in the Z-axis direction.

[0067] Here, the distance HF is the distance from the bottom surface TM to the upper surface TU in the Z-axis direction. The distance HE is a distance shorter than the distance H1. The distance H2 is a distance longer than the distance H1 and shorter than the distance HF. It should be noted that in the present embodiment, it is assumed that the difference value obtained by subtracting the distance H2 from the distance HF is larger than the distance HE. That is to say, in the present embodiment, it is assumed that when the lower opening OP1 and the upper opening OP2 are cut by a plane perpendicular to the direction from the ink liquid chamber RM1 to the ink liquid chamber RM2, the cross-sectional area of the lower opening OP1 is smaller than the cross-sectional area of the upper opening OP2.

[0068] It should be noted that in the present embodiment, it is assumed that the distance from the bottom surface TM to the electrode rod BT and the distance from the bottom surface TM to the electrode rod BK in the Z-axis direction are both the distance H1, but the present invention is not limited to such a scheme. The electrode rod BT and the electrode rod BK can also be set such that the longer one of the distance from the bottom surface TM to the electrode rod BT and the distance from the bottom surface TM to the electrode rod BK in the Z-axis direction is the distance H1. In addition, in the present embodiment, it is assumed that the distance H1 is longer than the distance HE, but the present invention is not limited to such a scheme. The distance H1 can also be shorter than the distance HE.

[0069] Hereinafter, the distance from the bottom surface TM of the ink tank TK to the liquid surface SF of the ink IK accommodated in the ink tank TK in the Z-axis direction is referred to as the ink liquid surface distance SZ.

[0070] As Figure 4 shown, when the ink liquid surface distance SZ is equal to or greater than the distance H1 and less than the distance H2, the ink IK exists in the lower opening OP1. And when the ink liquid surface distance SZ is equal to or greater than the distance H1, the electrode rod BT and the electrode rod BK are electrically connected through the ink IK existing in the lower opening OP1. Therefore, when the ink liquid surface distance SZ is equal to or greater than the distance H1 and less than the distance H2, the resistance of the ink IK electrically connecting the electrode rod BT and the electrode rod BK is the ink impedance RT1.

[0071] As Figure 5As shown, when the distance SZ from the ink liquid surface is greater than or equal to the distance H2, ink IK exists in the lower opening OP1 and the upper opening OP2. Also, when the distance SZ from the ink liquid surface is greater than or equal to the distance H2, the electrode rod BT and the electrode rod BK are electrically connected by the ink IK with the ink resistance RT1 existing in the lower opening OP1 and are electrically connected by the ink IK with the ink resistance RT2 existing in the upper opening OP2. Therefore, when the distance SZ from the ink liquid surface is greater than or equal to the distance H2, the resistance of the ink IK that electrically connects the electrode rod BT and the electrode rod BK is the combined resistance of the ink resistance RT1 and the ink resistance RT2 when the ink resistances RT1 and RT2 are connected in parallel.

[0072] It should be noted that hereinafter, the combined resistance of the ink resistance RT1 and the ink resistance RT2 is referred to as the ink resistance RG. That is, in the present embodiment, the resistance of the ink IK that electrically connects the electrode rod BT and the electrode rod BK is referred to as the ink resistance RG.

[0073] 3. Reference Example

[0074] The following refers to Figure 6 to describe the outline of the inkjet printer related to the reference example. It should be noted that the difference between the inkjet printer related to the reference example and the inkjet printer 100 related to the present embodiment is that it includes an ink storage device 1W instead of the ink storage device 1.

[0075] Figure 6 It is a circuit diagram for explaining the configuration of the ink storage device 1W.

[0076] As Figure 6 shown, the difference between the ink storage device 1W and the ink storage device 1 related to the present embodiment is that it includes an ink tank TK-W instead of the ink tank TK.

[0077] The difference between the ink tank TK-W and the ink tank TK related to the present embodiment is that it does not include the partition WL. That is, in the reference example, the electrode rod BT and the electrode rod BK are housed in the ink tank TK-W. In the reference example, similar to the present embodiment, it is considered that the electrode rod BT is set such that the distance from the end in the Z1 direction of the electrode rod BT to the bottom surface TM of the ink tank TK-W in the Z-axis direction is the distance H1, and the electrode rod BK is set such that the distance from the end in the Z1 direction of the electrode rod BK to the bottom surface TM of the ink tank TK-W in the Z-axis direction is the distance H1.

[0078] Note that, in the inkjet printer involved in the reference example, when the electrode rods BT and BK are in contact with the ink IK contained in the ink tank TK-W, the electrode rods BT and BK are electrically connected via the ink IK contained in the ink tank TK-W. Hereinafter, when the electrode rods BT and BK are electrically connected via the ink IK contained in the ink tank TK-W, the resistance of the ink IK that electrically connects the electrode rods BT and BK is referred to as the ink impedance RW. In addition, hereinafter, the output signal Vout output from the ink amount detection circuit 2 provided in the ink storage device 1W is referred to as the output signal Vout-W.

[0079] 4. Relationship between Ink Liquid Level Distance, Ink Impedance, and Output Signal

[0080] Figure 7 It is an explanatory diagram for explaining the impedance value change curve CR related to the present embodiment and the impedance value change curve CRW related to the reference example. Here, the impedance value change curve CR is a curve showing the relationship between the impedance value of the ink impedance RG in the present embodiment and the ink liquid level distance SZ. In addition, the impedance value change curve CRW is a curve showing the relationship between the impedance value of the ink impedance RW in the reference example and the ink liquid level distance SZ. Note that, in Figure 7 the horizontal axis is set as the ink liquid level distance SZ, and the vertical axis is set as the impedance value of the ink impedance, so as to represent the relationship between the ink liquid level distance SZ and the impedance value of the ink impedance as the impedance value change curve CR and the impedance value change curve CRW.

[0081] As described above, in the present embodiment and the reference example, when the ink liquid level distance SZ is less than the distance H1, the electrode rods BT and BK are not in contact with the ink IK. That is, when the ink liquid level distance SZ is less than the distance H1, the electrode rods BT and BK are in a non-electrically connected state. On the other hand, when the ink liquid level distance SZ is greater than or equal to the distance H1, the electrode rods BT and BK are in contact with the ink IK. That is, when the ink liquid level distance SZ is greater than or equal to the distance H1, the electrode rods BT and BK are in a state of being electrically connected through the ink IK.

[0082] Therefore, as Figure 7 shown by the impedance value change curve CR of, in the present embodiment, when the ink liquid level distance SZ is greater than or equal to the distance H1, the ink impedance RG has a smaller impedance value compared to the case where the ink liquid level distance SZ is less than the distance H1. That is, in the present embodiment, the impedance value change curve CR has a change region A-R1 where the ink impedance RG changes significantly at the boundary between the case where the ink liquid level distance SZ is less than the distance H1 and the case where the ink liquid level distance SZ is greater than or equal to the distance H1.

[0083] Similarly, as shown in Figure 7 the impedance value change curve CRW, even in the reference example, when the ink liquid level distance SZ is greater than or equal to the distance H1, the ink impedance RW is a smaller impedance value compared to the case where the ink liquid level distance SZ is less than the distance H1. That is to say, the impedance value change curve CRW related to the reference example is the same as the impedance value change curve CR related to the present embodiment. At the junction between the case where the ink liquid level distance SZ is less than the distance H1 and the case where the ink liquid level distance SZ is greater than or equal to the distance H1, there is a change region A-R1 where the ink impedance RW changes significantly.

[0084] In addition, in the present embodiment, when the ink liquid level distance SZ is greater than or equal to the distance H1 and less than or equal to the distance H2, the resistance of the ink IK electrically connecting the electrode rod BT and the electrode rod BK remains at an impedance value substantially the same as the impedance value of the ink impedance RT1. That is to say, as shown in Figure 7 the impedance value change curve CR, in the present embodiment, when the ink liquid level distance SZ is greater than or equal to the distance H1 and less than or equal to the distance H2, the ink impedance RG remains at a substantially the same impedance value.

[0085] Here, "substantially the same" includes, in addition to the exactly same case, the concept of cases that can be regarded as the same when considering errors. Specifically, in this specification, "substantially the same" includes the concept of cases that can be regarded as the same when considering an error of about 10%.

[0086] On the other hand, in the reference example, when the ink liquid level distance SZ is greater than or equal to the distance H1, as the ink liquid level distance SZ increases, the impedance value of the ink impedance RW decreases as the cross-sectional area of the ink IK electrically connecting the electrode rod BT and the electrode rod BK increases. Therefore, as shown in Figure 7 the impedance value change curve CRW, in the reference example, when the ink liquid level distance SZ is greater than or equal to the distance H1, the impedance value of the ink impedance RW decreases as the ink liquid level distance SZ increases.

[0087] In addition, in the present embodiment, when the ink liquid level distance SZ is greater than the distance H2, the electrode rod BT and the electrode rod BK are electrically connected not only by the ink IK with the ink impedance RT1 existing in the lower opening OP1 but also by the ink IK with the ink impedance RT2 existing in the upper opening OP2. And the impedance value of the combined impedance of the ink impedance RT1 and the ink impedance RT2 when they are connected in parallel is smaller than the individual impedance value of the ink impedance RT1. Therefore, as shown in Figure 7As shown by the impedance value change curve CR, in the present embodiment, when the distance SZ from the ink liquid level is longer than the distance H2, the ink impedance RG has a smaller impedance value compared to the case where the distance SZ from the ink liquid level is below the distance H2. That is to say, in the present embodiment, the impedance value change curve CR has a change region A-R2 where the ink impedance RG changes significantly at the junction between the case where the distance SZ from the ink liquid level is below the distance H2 and the case where the distance SZ from the ink liquid level is longer than the distance H2.

[0088] On the other hand, in the reference example, the partition WL is not provided in the ink tank TK-W. Therefore, as Figure 7 shown, the impedance value change curve CRW related to the reference example does not have the change region A-R2.

[0089] Moreover, in the present embodiment, when the distance SZ from the ink liquid level is longer than the distance H2, as the distance SZ from the ink liquid level becomes longer, the impedance value of the ink impedance RG decreases as the cross-sectional area of the ink IK electrically connecting the electrode rod BT and the electrode rod BK becomes larger. Therefore, as Figure 7 shown by the impedance value change curve CR, in the present embodiment, when the distance SZ from the ink liquid level is longer than the distance H2, the impedance value of the ink impedance RG decreases as the distance SZ from the ink liquid level becomes longer.

[0090] Thus, it can be seen that both the impedance value change curve CR related to the present embodiment and the impedance value change curve CRW related to the reference example have the change region A-R1.

[0091] On the other hand, the impedance value change curve CR related to the present embodiment has the change region A-R2, while the impedance value change curve CRW related to the reference example does not have the change region A-R2, but has a smooth shape in which the ink impedance RW continuously decreases as the distance SZ from the ink liquid level becomes longer.

[0092] Figure 8 FIG. is an explanatory diagram for explaining the potential change curve CV related to the present embodiment and the potential change curve CVW related to the reference example. Here, the potential change curve CV is a curve showing the relationship between the output signal Vout output from the ink amount detection circuit 2 in the present embodiment and the distance SZ from the ink liquid level. In addition, the potential change curve CVW is a curve showing the relationship between the output signal Vout-W output from the ink amount detection circuit 2 in the reference example and the distance SZ from the ink liquid level. It should be noted that in Figure 8 the horizontal axis is set as the distance SZ from the ink liquid level, and the vertical axis is set as the potential of the output signal Vout, so as to represent the relationship between the distance SZ from the ink liquid level and the potential of the output signal Vout as the potential change curve CV and the potential change curve CVW.

[0093] As described above, the potential of the output signal Vout, i.e., the potential of the node NK, is determined by the impedance value of the ink impedance RG. Specifically, in the present embodiment, as an example, it is assumed that, when the impedance value of the ink impedance RG is large, the potential of the output signal Vout becomes higher than when it is small.

[0094] As described above, the impedance value change curve CR has a change region A-R1. Therefore, as Figure 8 shown, the potential change curve CV also has a change region A-V1, which is a region where the potential of the output signal Vout changes significantly at the boundary between the case where the ink liquid level distance SZ is less than the distance H1 and the case where the ink liquid level distance SZ is equal to or greater than the distance H1.

[0095] In addition, as described above, the impedance value change curve CRW also has a change region A-R1. Therefore, as Figure 8 shown, the potential change curve CVW also has a change region A-V1, which is a region where the potential of the output signal Vout-W changes significantly at the boundary between the case where the ink liquid level distance SZ is less than the distance H1 and the case where the ink liquid level distance SZ is equal to or greater than the distance H1.

[0096] In addition, as described above, the impedance value change curve CR has a change region A-R2. Therefore, as Figure 8 shown, the potential change curve CV also has a change region A-V2, which is a region where the potential of the output signal Vout changes significantly at the boundary between the case where the ink liquid level distance SZ is equal to or less than the distance H2 and the case where the ink liquid level distance SZ is longer than the distance H2.

[0097] It should be noted that, as described above, the impedance value change curve CRW does not have a change region A-R2. Therefore, as Figure 8 shown, the potential change curve CVW also does not have a change region A-V2.

[0098] Hereinafter, when the temperature of the ink IK in the ink tank TK is the reference temperature t1 and the ink liquid level distance SZ in the ink tank TK is the distance H1, the potential indicated by the output signal Vout according to the present embodiment is referred to as the threshold potential Vth1. It should be noted that, as Figure 8 shown, when the temperature of the ink IK in the ink tank TK-W is the reference temperature t1 and the ink liquid level distance SZ in the ink tank TK-W is the distance H1, the potential indicated by the output signal Vout-W in the reference example is also the threshold potential Vth1.

[0099] In addition, hereinafter, when the temperature of the ink IK in the ink tank TK is the reference temperature t1 and the distance SZ of the ink liquid level in the ink tank TK is the distance H2, the potential shown by the output signal Vout in the present embodiment is referred to as the threshold potential Vth2. It should be noted that, as Figure 8 shown, when the temperature of the ink IK in the ink tank TK-W is the reference temperature t1 and the distance SZ of the ink liquid level in the ink tank TK-W is the distance H2, the potential shown by the output signal Vout-W represented by the potential change curve CVW in the reference example is a potential lower than the threshold potential Vth2.

[0100] Here, the reference temperature t1 is, for example, the temperature of the ink IK in the ink tank TK when the inkjet printer 100 is used in the standard usage environment of the inkjet printer 100. In addition, the reference temperature t1 can also be, for example, the ambient temperature of the inkjet printer 100 when the inkjet printer 100 is used in the standard usage environment of the inkjet printer 100. In addition, the reference temperature t1 can also be, for example, the temperature of the standard usage environment of the ink IK.

[0101] As described above, in the present embodiment, the control device 8 determines the remaining amount of the ink IK accommodated in the ink tank TK based on the output signal Vout.

[0102] Specifically, in the present embodiment, when the potential of the output signal Vout is a potential higher than the threshold potential Vth1, the control device 8 determines that the remaining amount of the ink IK in the ink tank TK is insufficient for the ink amount corresponding to the distance H1; when the potential of the output signal Vout is a potential lower than the threshold potential Vth1, the control device 8 determines that the remaining amount of the ink IK in the ink tank TK is an amount larger than the ink amount corresponding to the distance H1.

[0103] Here, the ink amount corresponding to the distance H1 is an amount based on the minimum amount of the ink IK in the ink tank TK. Specifically, the amount based on the minimum amount of the ink IK in the ink tank TK can be either the ink amount that can eject the ink IK from the liquid ejection head HU with the minimum ink amount according to the ink IK supplied from the ink tank TK, or the ink amount whose difference from the minimum ink amount is below the first differential amount. Here, the first differential amount can be, for example, the ink amount below the ink amount required for the inkjet printer 100 to form an image on a predetermined number of sheets of the medium PP, or the ink amount when the ink IK can be ejected from the liquid ejection head HU a predetermined number of times or less. That is, the ink amount corresponding to the distance H1 can also be the ink amount corresponding to the so-called "ink exhaustion" state.

[0104] It should be noted that, in the present embodiment, the ink amount corresponding to the distance H1 is an example of the "amount based on the minimum amount of the liquid in the storage container".

[0105] Further, in the present embodiment, when the potential of the output signal Vout is a potential higher than the threshold potential Vth2, the control device 8 determines that the remaining amount of the ink IK in the ink tank TK is insufficient by an amount of ink corresponding to the distance H2; when the potential of the output signal Vout is a potential lower than the threshold potential Vth2, the control device 8 determines that the remaining amount of the ink IK in the ink tank TK is more than the amount of ink corresponding to the distance H2.

[0106] Here, the amount of ink corresponding to the distance H2 is an amount based on the maximum amount of the ink IK in the ink tank TK. Specifically, the amount based on the maximum amount of the ink IK in the ink tank TK may be the maximum amount of ink that can be accommodated in the ink tank TK, or may be an amount of ink such that the difference from the maximum amount of ink is equal to or less than a second difference amount. Here, the second difference amount may be, for example, the amount of ink that a user of the inkjet printer 100 can supply into the ink tank TK from a bottle containing the ink IK through the supply port 12 within a predetermined time. Additionally, for example, the second difference amount may also be the minimum amount of ink IK that a user of the inkjet printer 100 can supply to the ink tank TK using a bottle containing the ink IK. That is, the amount of ink corresponding to the distance H2 may also be an amount of ink corresponding to a state called "full".

[0107] It should be noted that, in the present embodiment, the amount of ink corresponding to the distance H2 is an example of "an amount based on the maximum amount of the liquid in the storage container".

[0108] Further, in the reference example, similar to the present embodiment, when the potential of the output signal Vout-W is a potential higher than the threshold potential Vth1, the control device 8 determines that the remaining amount of the ink IK in the ink tank TK-W is insufficient by an amount of ink corresponding to the distance H1; when the potential of the output signal Vout-W is a potential lower than the threshold potential Vth1, the control device 8 determines that the remaining amount of the ink IK in the ink tank TK-W is more than the amount of ink corresponding to the distance H1.

[0109] On the other hand, in the reference example, different from the present embodiment, based on the determination result of whether the potential of the output signal Vout-W is a potential higher than the threshold potential Vth2, the control device 8 cannot determine whether the remaining amount of the ink IK in the ink tank TK-W is insufficient by an amount of ink corresponding to the distance H2.

[0110] Figure 9 It is an explanatory diagram for explaining the temperature change of the impedance value change curve CR accompanying the temperature change of the ink IK in the ink tank TK according to the present embodiment.

[0111] Specifically, in Figure 9Among them, when the temperature of the ink IK in the ink tank TK is the reference temperature t1, the impedance value change curve CR is expressed as the impedance value change curve CR(t1). Additionally, when the temperature of the ink IK in the ink tank TK is a temperature t2 different from the reference temperature t1, the impedance value change curve CR is expressed as the impedance value change curve CR(t2).

[0112] As Figure 9 shown, when the temperature of the ink IK in the ink tank TK changes, the impedance value shown by the impedance value change curve CR also changes. Specifically, when the temperature of the ink IK in the ink tank TK changes from the reference temperature t1 to the temperature t2, the impedance value of the ink impedance RG shown by the impedance value change curve CR also changes. That is, even when the ink liquid level distance SZ is the same value, the impedance value of the ink impedance RG shown by the impedance value change curve CR(t1) and the impedance value of the ink impedance RG shown by the impedance value change curve CR(t2) are different.

[0113] As described above, the impedance value change curve CR according to the present embodiment has a change region A-R1 in the portion where the ink liquid level distance SZ is the distance H1. That is to say, in the change region A-R1 including the portion where the ink liquid level distance SZ is the distance H1 in the impedance value change curve CR, the impedance value of the ink impedance RG shown by the impedance value change curve CR changes significantly. Therefore, in Figure 9 the vertical axis direction of the chart shown, a part of the change region A-R1 of the impedance value change curve CR(t1) overlaps with a part of the change region A-R1 of the impedance value change curve CR(t2).

[0114] Additionally, as described above, the impedance value change curve CR according to the present embodiment has a change region A-R2 in the portion where the ink liquid level distance SZ is the distance H2. That is to say, in the change region A-R2 including the portion where the ink liquid level distance SZ is the distance H2 in the impedance value change curve CR, the impedance value of the ink impedance RG shown by the impedance value change curve CR changes significantly. Therefore, in Figure 9 the vertical axis direction of the chart shown, a part of the change region A-R2 of the impedance value change curve CR(t1) overlaps with a part of the change region A-R2 of the impedance value change curve CR(t2).

[0115] Figure 10 It is an explanatory diagram for explaining the temperature change of the potential change curve CV accompanying the temperature change of the ink IK in the ink tank TK according to the present embodiment.

[0116] Specifically, in Figure 10In this case, the potential change curve CV when the temperature of the ink IK in the ink tank TK is the reference temperature t1 is expressed as the potential change curve CV(t1). Additionally, the potential change curve CV when the temperature of the ink IK in the ink tank TK is the temperature t2 is expressed as the potential change curve CV(t2).

[0117] As Figure 10 shown, when the temperature of the ink IK in the ink tank TK changes, the potential shown by the potential change curve CV also changes. Specifically, when the temperature of the ink IK in the ink tank TK changes from the reference temperature t1 to the temperature t2, the potential of the output signal Vout shown by the potential change curve CV also changes. That is, even when the ink liquid level distance SZ is the same value, the potential of the output signal Vout shown by the potential change curve CV(t1) is different from the potential of the output signal Vout shown by the potential change curve CV(t2).

[0118] As described above, the potential change curve CV according to this embodiment has a change region A-V1, which is a region where the potential of the output signal Vout shown by the partial potential change curve CV at the part where the ink liquid level distance SZ is the distance H1 changes significantly. And the change region A-V1 possessed by the potential change curve CV(t1) intersects with Figure 10 the straight line "Vout = Vth1" in the graph shown.

[0119] Additionally, since the change region A-V1 is a region where the potential of the output signal Vout shown by the potential change curve CV changes significantly, thus in Figure 10 the vertical axis direction of the graph shown, a part of the change region A-V1 possessed by the potential change curve CV(t1) overlaps with a part of the change region A-V1 possessed by the potential change curve CV(t2). And if the temperature difference between the reference temperature t1 and the temperature t2 is within a predetermined temperature difference, then the change region A-V1 possessed by the potential change curve CV(t2) intersects with Figure 10 the straight line "Vout = Vth1" in the graph shown.

[0120] Here, the predetermined temperature difference can also be, for example, the temperature difference between the temperature of the ink IK in the ink tank TK and the reference temperature t1 when the inkjet printer 100 is used in the extreme usage environment of the inkjet printer 100. Additionally, the predetermined temperature difference can also be, for example, the temperature difference between the ambient temperature of the inkjet printer 100 and the reference temperature t1 when the inkjet printer 100 is used in the extreme usage environment of the inkjet printer 100. Additionally, the predetermined temperature difference can also be, for example, the temperature difference between the temperature of the extreme usage environment of the ink IK and the reference temperature t1.

[0121] As described above, the potential change curve CV of this embodiment has a change region A-V2, which is a region where the potential of the output signal Vout shown in the partial potential change curve CV at a distance SZ of the ink liquid surface of H2 changes significantly. And, the change region A-V2 of the potential change curve CV(t1) intersects with Figure 10 the straight line "Vout = Vth2" in the graph shown.

[0122] In addition, since the change region A-V2 is a region where the potential of the output signal Vout shown in the potential change curve CV changes significantly, in the Figure 10 vertical axis direction of the graph shown, a part of the change region A-V2 of the potential change curve CV(t1) overlaps with a part of the change region A-V2 of the potential change curve CV(t2). Therefore, if the temperature difference between the reference temperature t1 and the temperature t2 is within a predetermined temperature difference, the change region A-V2 of the potential change curve CV(t2) intersects with Figure 10 the straight line "Vout = Vth2" in the graph shown.

[0123] Therefore, according to this embodiment, when the temperature of the ink IK in the ink tank TK is the reference temperature t1 and the temperature t2, based on the potential of the output signal Vout being higher than the threshold potential Vth1, it is possible to determine that the remaining amount of the ink IK in the ink tank TK is insufficient by the ink amount corresponding to the distance H1; based on the potential of the output signal Vout being higher than the threshold potential Vth2, it is possible to determine that the remaining amount of the ink IK in the ink tank TK is insufficient by the ink amount corresponding to the distance H2.

[0124] On the other hand, according to the reference example, similar to this embodiment, when the temperature of the ink IK in the ink tank TK-W is the reference temperature t1 and the temperature t2, based on the potential of the output signal Vout-W being higher than the threshold potential Vth1, it is possible to determine that the remaining amount of the ink IK in the ink tank TK is insufficient by the ink amount corresponding to the distance H1. However, according to the reference example, different from the first embodiment, when the temperature of the ink IK in the ink tank TK-W is the reference temperature t1 and the temperature t2, based on the potential of the output signal Vout-W being higher than the threshold potential Vth2, the remaining amount of the ink IK in the ink tank TK cannot be determined.

[0125] That is, according to the inkjet printer 100 of this embodiment, compared with the inkjet printer of the reference example, the remaining amount of the ink IK in the ink tank TK can be accurately detected based on the output signal Vout.

[0126] It should be noted that in this embodiment, the following situation is illustrated and described. That is, due to the temperature change of the ink IK in the ink tank TK, the impedance value of the ink impedance RG changes. As a result, the potential of the output signal Vout shown in the potential change curve CV changes. However, the present invention is not limited to such a solution. This embodiment can be applied to any situation where the potential of the output signal Vout shown in the potential change curve CV changes.

[0127] For example, according to this embodiment, even when the potential of the output signal Vout shown in the potential change curve CV changes due to the deterioration or denaturation of the ink IK in the ink tank TK, compared with the reference example, the remaining amount of the ink IK in the ink tank TK can be accurately detected based on the output signal Vout. In addition, according to this embodiment, when the potential of the output signal Vout shown in the potential change curve CV changes due to noise being superimposed on the output signal Vout, compared with the reference example, the remaining amount of the ink IK in the ink tank TK can also be accurately detected based on the output signal Vout.

[0128] 5. Summary of the Embodiment

[0129] As described above, the inkjet printer 100 according to this embodiment is characterized by including: an ink tank TK that houses conductive ink IK; an electrode rod BT that is housed in the ink liquid chamber RM1 of the ink tank TK; an electrode rod BK that is housed in the ink liquid chamber RM2 of the ink tank TK; a partition WL that is housed in the ink tank TK and separates the ink liquid chamber RM1 and the ink liquid chamber RM2; an ink amount detection circuit 2 that is electrically connected to the electrode rod BT and the electrode rod BK and outputs an output signal Vout corresponding to the electrical signal from the electrode rod BK; and a control device 8 that determines the remaining amount of the ink IK housed in the ink tank TK based on the output signal Vout. A lower opening OP1 that connects the ink liquid chamber RM1 and the ink liquid chamber RM2 is formed in the Z1 direction of the partition WL, and an upper opening OP2 that connects the ink liquid chamber RM1 and the ink liquid chamber RM2 is formed in the Z2 direction of the partition WL. When there is ink IK housed in the ink tank TK in the lower opening OP1 and the upper opening OP2, the electrode rod BT and the electrode rod BK are in contact with the ink IK housed in the ink tank TK.

[0130] That is, in the present embodiment, the electrode rods BT and BK can adopt any one of three connection states, namely, the first connection state, the second connection state, and the third connection state, according to the remaining amount of the ink IK in the ink tank TK. The first connection state is a state where the electrode rods BT and BK are not electrically connected through the ink IK in the ink tank TK. The second connection state is a state where the electrode rods BT and BK are electrically connected through the ink IK present in the lower opening OP1. The third connection state is a state where the electrode rods BT and BK are electrically connected through the ink IK present in the lower opening OP1 and the upper opening OP2. Therefore, in the present embodiment, when the remaining amount of the ink IK in the ink tank TK changes, the ink amount detection circuit 2 can cause a significant change in the potential of the output signal Vout at the boundary between the first connection state and the second connection state and at the boundary between the second connection state and the third connection state. Thus, according to the present embodiment, even when the remaining amount of the ink IK in the ink tank TK changes, compared with the conventional solution where the potential of the output signal Vout changes smoothly, the remaining amount of the ink IK in the ink tank TK can be accurately detected.

[0131] In addition, in the inkjet printer 100 according to the present embodiment, it is characterized in that the cross-sectional area of the lower opening OP1 is smaller than the cross-sectional area of the upper opening OP2.

[0132] Therefore, according to the present embodiment, compared with the case where the cross-sectional area of the lower opening OP1 is larger than the cross-sectional area of the upper opening OP2, the change amount of the output signal Vout at the boundary between the second connection state and the third connection state can be increased. Thus, according to the present embodiment, compared with the case where the cross-sectional area of the lower opening OP1 is larger than the cross-sectional area of the upper opening OP2, the remaining amount of the ink IK in the ink tank TK can be accurately detected.

[0133] In addition, in the inkjet printer 100 according to the present embodiment, it is characterized in that the impedance value of the resistance between the electrode rods BT and BK when the ink IK accommodated in the ink tank TK is present in the upper opening OP2 is smaller than the impedance value of the resistance between the electrode rods BT and BK when the ink IK accommodated in the ink tank TK is not present in the upper opening OP2.

[0134] In addition, in the inkjet printer 100 according to the present embodiment, it is characterized in that the impedance value of the resistance between the electrode rods BT and BK when the ink IK accommodated in the ink tank TK is present in the lower opening OP1 is less than or equal to the impedance value of the resistance between the electrode rods BT and BK when the ink IK accommodated in the ink tank TK is not present in the lower opening OP1.

[0135] In addition, in the inkjet printer 100 according to the present embodiment, it may also be characterized in that when there is ink IK stored in the ink tank TK in the upper opening OP2, the control device 8 determines the remaining amount of the ink IK stored in the ink tank TK as an amount based on the maximum amount of the ink IK that can be stored in the ink tank TK.

[0136] In this case, when replenishing the ink IK into the ink tank TK, it is possible to pre-confirm the possibility of the ink IK overflowing from the ink tank TK.

[0137] In addition, in the inkjet printer 100 according to the present embodiment, it may also be characterized in that when changing from a state where the electrode rod BT and the electrode rod BK are electrically connected through the ink IK stored in the ink tank TK to a state where at least one of the electrode rod BT and the electrode rod BK is not in contact with the ink IK stored in the ink tank TK, the control device 8 determines the remaining amount of the ink IK stored in the ink tank TK as an amount based on the minimum amount of the ink IK in the ink tank TK.

[0138] In this case, it is possible to pre-confirm the exhaustion of the ink IK in the ink tank TK.

[0139] In addition, in the inkjet printer 100 according to the present embodiment, it is characterized in that the partition WL is made of an insulator.

[0140] Therefore, according to the present embodiment, compared with the solution in which the partition WL is formed of a conductive material, it is possible to accurately detect the remaining amount of the ink IK in the ink tank TK.

[0141] In addition, in the inkjet printer 100 according to the present embodiment, it is characterized in that the ink tank TK is provided with a supply port 12 for supplying the ink IK to the internal space of the ink tank TK for storing the ink IK.

[0142] B. Variation

[0143] Each of the above-exemplified embodiments can be variously modified. Specific modification schemes are exemplified below. Two or more schemes arbitrarily selected from the following exemplifications can be appropriately combined within a non-conflicting range.

[0144] B.1. Variation 1

[0145] In the above-described present embodiment, the case where the ink storage device 1 includes the output circuit 20 is illustrated, but the present invention is not limited to such a solution. The ink storage device 1 only needs to be a device including an output circuit 20 that can detect the remaining amount of the ink IK stored in the ink tank TK based on an electrical signal from one or more electrode rods provided in the ink tank TK.

[0146] Figure 11A circuit diagram showing an example of the configuration of the ink storage device 1Q included in the inkjet printer according to Modification 1. Note that the inkjet printer according to Modification 1 is different from the inkjet printer 100 according to the embodiment in that it includes the ink storage device 1Q instead of the ink storage device 1. In addition, the ink storage device 1Q is different from the ink storage device 1 according to the embodiment in that it includes the ink level detection circuit 2Q instead of the ink level detection circuit 2. That is, the ink storage device 1Q includes the ink level detection circuit 2Q and the ink tank TK.

[0147] As Figure 11 shown, the ink level detection circuit 2Q includes an input terminal TnN, a detection terminal TnK, a reference potential connection terminal TnT, an output terminal TnS, a capacitor CQ1, and an output circuit 20Q having a node NK.

[0148] An input signal Vin is input to the input terminal TnN. The detection terminal TnK is electrically connected to the electrode rod BK via the detection wiring LK. The reference potential connection terminal TnT is electrically connected to the electrode rod BT via the reference potential connection wiring LT. The output terminal TnS outputs an output signal Vout. In the capacitor CQ1, one of the two electrodes of the capacitor CQ1 is electrically connected to the reference potential connection terminal TnT, and the other electrode is electrically connected to the wiring set to the ground potential.

[0149] The output circuit 20Q includes a node NK, a node NQ1, a node NQ2, a node NQ3, an input impedance RN, an impedance RQ1, an impedance RQ2, a capacitor CQ2, and a switch SWQ.

[0150] The node NK is electrically connected to the detection terminal TnK and to one end of the input impedance RN.

[0151] The node NQ1 is electrically connected to the other end of the input impedance RN, to the input terminal TnN, and is supplied with the input signal Vin via the input terminal TnN.

[0152] The switch SWQ has two input terminals, one output terminal, and one control terminal. One of the two input terminals of the switch SWQ is electrically connected to the node NK, and the other input terminal is electrically connected to one end of the impedance RQ1. The output terminal of the switch SWQ is electrically connected to the node NQ2. The input signal Vin is supplied to the control terminal of the switch SWQ via the node NQ1.

[0153] In this modification, the input signal Vin is a signal set to either a high level or a low level signal level.

[0154] Moreover, in this modified example, when the input signal Vin supplied to the switch SWQ is at a low level, the switch SWQ electrically connects the output terminal of the switch SWQ and one of the two input terminals of the switch SWQ. That is, in this modified example, when the input signal Vin supplied to the switch SWQ is at a low level, the switch SWQ electrically connects the node NK and the node NQ2.

[0155] In addition, in this modified example, when the input signal Vin supplied to the switch SWQ is at a high level, the switch SWQ electrically connects the output terminal of the switch SWQ and the other of the two input terminals of the switch SWQ. That is, in this modified example, when the input signal Vin supplied to the switch SWQ is at a high level, the switch SWQ electrically connects one end of the impedance RQ1 and the node NQ2.

[0156] In the impedance RQ1, one end is electrically connected to the other of the two input terminals of the switch SWQ, and the other end is electrically connected to the wiring set to the ground potential.

[0157] In the impedance RQ2, one end is electrically connected to the node NQ2, and the other end is electrically connected to the node NQ3.

[0158] In the capacitor CQ2, one of the two electrodes of the capacitor CQ2 is electrically connected to the node NQ3, and the other electrode is electrically connected to the wiring set to the ground potential. It should be noted that the impedance RQ2 and the capacitor CQ2 function as a low-pass filter.

[0159] The output terminal TnS is electrically connected to the node NQ3 and outputs an output signal Vout representing the potential of the node NQ3.

[0160] Figure 12 It is a timing diagram for explaining various signals flowing through the ink amount detection circuit 2Q.

[0161] As Figure 12 shown, in this modified example, it is assumed that the operation period of the ink amount detection circuit 2Q is divided into a plurality of unit periods TQ. Moreover, in this modified example, it is assumed that each unit period TQ is divided into a control period TP1 and a control period TP2.

[0162] The input signal Vin is set to a high level during the control period TP1 in the unit period TQ, and set to a low level during the control period TP2 in the unit period TQ.

[0163] The signal VQK is a signal representing the potential of the node NK. Hereinafter, the signal VQK in the case where the ink IK stored in the ink tank TK is insufficient by an ink amount corresponding to the distance H1, that is, when the ink IK in the ink tank TK runs out, is referred to as the signal VQK-E. In addition, the signal VQK in the case where the ink IK stored in the ink tank TK is more than the ink amount corresponding to the distance H2, that is, when the ink IK in the ink tank TK is abundant, is referred to as the signal VQK-F.

[0164] When the ink IK in the ink tank TK runs out, the electrode rod BT and the electrode rod BK are in a non-electrically connected state. Therefore, the signal VQK-E shows a waveform of a shape linked to the input signal Vin. Specifically, compared with the timing when the input signal Vin rises from the low level to the high level, the signal VQK-E rises from the low level to the high level after a delay time TQK-E; compared with the timing when the input signal Vin falls from the high level to the low level, the signal VQK-E falls from the high level to the low level after a delay time TQK-E. Here, the time TQK-E is a time shorter than the time length of the control period TP1 and shorter than the time length of the control period TP2, and is a time for charging the capacitance parasitic on the detection wiring LK, the electrode rod BK, etc.

[0165] When the ink IK in the ink tank TK is abundant, the electrode rod BT and the electrode rod BK are in an electrically connected state. Therefore, the signal VQK-F shows a waveform of a shape obtained by smoothing the input signal Vin. Specifically, compared with the timing when the input signal Vin rises from the low level to the high level, the signal VQK-F rises from the low level to the high level after a delay time TQK-F; compared with the timing when the input signal Vin falls from the high level to the low level, the signal VQK-F falls from the high level to the low level after a delay time TQK-F. Here, the time TQK-F is a time longer than the time TQK-E, and is a time for charging not only the capacitance parasitic on the detection wiring LK, the electrode rod BK, etc., but also the capacitance parasitic on the reference potential connection wiring LT, the electrode rod BT, etc. and the capacitance CQ1.

[0166] The signal VQ2 is a signal representing the potential of the node NQ2. Hereinafter, the signal VQ2 in the case where the ink IK in the ink tank TK runs out and the ink liquid level distance SZ in the ink tank TK is less than the distance H1 is referred to as the signal VQ2-E. In addition, the signal VQ2 in the case where the ink IK in the ink tank TK is abundant and the ink liquid level distance SZ in the ink tank TK is longer than the distance H2 is referred to as the signal VQ2-F.

[0167] As described above, during the control period TP1 when the input signal Vin is at a high level, the switch SWQ electrically connects the node NQ2 and one end of the impedance RQ1. Therefore, during the control period TP1, the signal VQ2 is set to a low level.

[0168] Also, during the control period TP2 when the input signal Vin is at a low level, the switch SWQ electrically connects the node NQ2 and the node NK. Therefore, during the control period TP2, the signal VQ2-E shows a waveform shaped such that it takes time TQK-E to fall from a high level to a low level. Additionally, during the control period TP2, the signal VQ2-F shows a waveform shaped such that it takes time TQK-F to fall from a high level to a low level.

[0169] The signal VQ3 is a signal representing the potential of the node NQ3. Hereinafter, the signal VQ3 in the case where the ink IK in the ink tank TK is depleted and the ink liquid level distance SZ in the ink tank TK is less than the distance H1 is referred to as the signal VQ3-E. Additionally, the signal VQ3 in the case where the ink IK in the ink tank TK is abundant and the ink liquid level distance SZ in the ink tank TK is longer than the distance H2 is referred to as the signal VQ3-F.

[0170] As described above, the impedance RQ2 and the capacitor CQ2 function as a low-pass filter. Therefore, the signal VQ3 is a signal having a waveform obtained by removing high-frequency components from the signal VQ2. And, as described above, the time TQK-F is longer than the time TQK-E. Therefore, the potential of the signal VQ3-F is higher than the potential of the signal VQ3-E. That is, in this modification example, when the ink IK in the ink tank TK is abundant and the ink liquid level distance SZ in the ink tank TK is longer than the distance H2, compared with the case where the ink IK in the ink tank TK is depleted and the ink liquid level distance SZ in the ink tank TK is less than the distance H1, the ink amount detection circuit 2Q outputs an output signal Vout at a high potential.

[0171] B.2. Modification Example 2

[0172] In the above-described embodiment and modification example 1, an example was illustrated in which M ink amount detection circuits 2 corresponding one-to-one to M ink tanks TK[1] to TK[M] are provided in the ink storage device 1, but the present invention is not limited to such a configuration. In the ink storage device 1, it is also possible to provide a smaller number of ink amount detection circuits 2 than M.

[0173] For example, an ink amount detection circuit 2 may also be provided in the ink storage device 1. In this case, regarding the ink amount detection circuit 2, for example, the operation period of the ink amount detection circuit 2 may be divided into M unit operation periods, and the remaining amount of the ink IK stored in the ink tank TK[m] may be detected within the m-th unit operation period. Specifically, the ink amount detection circuit 2 may be configured to switch the ink tank TK[m] to which the ink amount detection circuit 2 is connected within each unit operation period.

[0174] B.3. Variant Example 3

[0175] In the above-described embodiments, Variant Example 1, and Variant Example 2, an inkjet printer of a serial type in which the storage box 921 equipped with the liquid ejection head HU reciprocates in the main scanning direction MH1 is illustrated, but the present invention is not limited to such a configuration. The inkjet printer may also be a line-type liquid ejection device including a liquid ejection head HU capable of ejecting the ink IK across the entire width of the medium PP.

[0176] B.4. Variant Example 4

[0177] In the above-described embodiments, Variant Example 1 to Variant Example 3, it is illustrated that the liquid ejection device of the inkjet printer can be adopted in various devices such as a facsimile machine and a copying machine in addition to printing dedicated equipment. However, the use of the liquid ejection device of the present invention is not limited to printing. For example, a liquid ejection device that ejects a coloring material solution is used as a manufacturing device for forming a color filter of a liquid crystal display device. In addition, a liquid ejection device that ejects a conductive material solution is used as a manufacturing device for forming wirings and electrodes of a wiring substrate.

Claims

1. A liquid ejection device, characterized in that: have: A receiving container for receiving a conductive liquid; a first electrode, housed in a first liquid chamber of the housing container; a second electrode, housed in the second liquid chamber of the housing container; a partition plate, which is received in the receiving container and divides the first liquid chamber and the second liquid chamber; a detection unit electrically connected to the first electrode and the second electrode, and outputting a detection signal corresponding to the electrical signal from one of the first electrode and the second electrode; as well as a determination unit that determines a remaining amount of the liquid contained in the storage container based on the detection signal, A first opening is formed below the partition plate to connect the first liquid chamber and the second liquid chamber. A second opening is formed above the partition plate to connect the first liquid chamber and the second liquid chamber. When the liquid contained in the storage container exists in the first opening and the second opening, The first electrode and the second electrode are in contact with the liquid contained in the containing container.

2. The liquid ejection device according to claim 1, characterized in that: A cross-sectional area of ​​the first opening is smaller than a cross-sectional area of ​​the second opening.

3. The liquid ejection device according to claim 1, characterized in that: an impedance value of the resistance between the first electrode and the second electrode when the liquid contained in the containing container exists in the second opening, The impedance value is smaller than the resistance between the first electrode and the second electrode when the liquid contained in the containing container does not exist in the second opening.

4. The liquid ejection device according to claim 1, characterized in that: an impedance value of the resistance between the first electrode and the second electrode when the liquid contained in the containing container exists in the first opening, The resistance value is equal to or less than the resistance value of the electrical resistance between the first electrode and the second electrode when the liquid contained in the containing container does not exist in the first opening.

5. The liquid ejection device according to claim 1, characterized in that: When the liquid contained in the storage container exists in the second opening, The determination unit determines the remaining amount of the liquid stored in the storage container as an amount based on a maximum amount of the liquid in the storage container.

6. The liquid ejection device according to claim 1, characterized in that: When the state in which the first electrode and the second electrode are in contact with the liquid contained in the storage container changes to a state in which at least one of the first electrode and the second electrode is not in contact with the liquid contained in the storage container, The determination unit determines the remaining amount of the liquid stored in the storage container as an amount based on a minimum amount of the liquid in the storage container.

7. The liquid ejection device according to claim 1, characterized in that: The partition is made of an insulator.

8. The liquid ejection device according to claim 1, characterized in that: The storage container includes a supply port for supplying liquid to an internal space of the storage container for storing the liquid.

9. A liquid containing device, characterized in that: have: A receiving container for receiving a conductive liquid; a first electrode, housed in a first liquid chamber of the housing container; a second electrode, housed in the second liquid chamber of the housing container; a partition plate, which is received in the receiving container and divides the first liquid chamber and the second liquid chamber; as well as a detection unit electrically connected to the first electrode and the second electrode, and outputting a detection signal corresponding to the electrical signal from one of the first electrode and the second electrode, A first opening is formed below the partition plate to connect the first liquid chamber and the second liquid chamber. A second opening is formed above the partition plate to connect the first liquid chamber and the second liquid chamber. When the liquid contained in the storage container exists in the first opening and the second opening, The first electrode and the second electrode are in contact with the liquid contained in the containing container.

10. The liquid containing device according to claim 9, characterized in that: A cross-sectional area of ​​the first opening is smaller than a cross-sectional area of ​​the second opening.

11. The liquid containing device according to claim 9, characterized in that: an impedance value of the resistance between the first electrode and the second electrode when the liquid contained in the containing container exists in the second opening, The impedance value is smaller than the resistance between the first electrode and the second electrode when the liquid contained in the containing container does not exist in the second opening.

12. The liquid containing device according to claim 9, characterized in that: an impedance value of the resistance between the first electrode and the second electrode when the liquid contained in the containing container exists in the first opening, The resistance value is equal to or less than the resistance value of the electrical resistance between the first electrode and the second electrode when the liquid contained in the containing container does not exist in the first opening.

13. The liquid containing device according to claim 9, characterized in that: When the liquid contained in the storage container exists in the second opening, The detection unit outputs the detection signal for determining the remaining amount of the liquid contained in the storage container as an amount based on a maximum amount of the liquid in the storage container.

14. The liquid containing device according to claim 9, characterized in that: When the state in which the first electrode and the second electrode are in contact with the liquid contained in the storage container changes to a state in which at least one of the first electrode and the second electrode is not in contact with the liquid contained in the storage container, The detection unit outputs the detection signal for determining the remaining amount of the liquid stored in the storage container as an amount based on a minimum amount of the liquid in the storage container.

15. The liquid containing device according to claim 9, characterized in that: The partition is made of an insulator.

16. The liquid containing device according to claim 9, characterized in that: The storage container includes a supply port for supplying liquid to an internal space of the storage container for storing the liquid.

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