JP2012206455A - Liquid supply device and ink jet printer with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid supply device capable of accurately obtaining a remaining amount of liquid or an amount of the consumption of the liquid in a main tank, and to provide an ink jet printer with the same.SOLUTION: The ink jet printer 1 includes the liquid supply device 11. The liquid supply device 11 includes the main tank 13, a first support 37 connected to one side of the main tank 13 and supporting the main tank 13 so as to be turnable around a horizontal axis P, a second support 39 supporting the other side on the opposite side of one side of the main tank 13 for keeping the main tank 13 at a constant position, a load sensor 21 measuring a load that the second support 39 receives from the main tank 13, and a control part 27 obtaining the weight of the liquid in the tank stored in the main tank 13 based on a detection result of the load sensor 21. Weight in the tank is obtained on the basis of the load that the second support 39 receives from the main tank 13.

Description

  The present invention relates to a liquid supply device and an ink jet printing apparatus including the same, and more particularly to a technique for acquiring the remaining amount of liquid in a main tank.

  A liquid supply apparatus that supplies a liquid is applied to various apparatuses. For example, in the case of an inkjet printing apparatus, a liquid supply apparatus for supplying ink to an inkjet head (nozzle) is provided. Hereinafter, for convenience, a liquid supply device applied to an ink jet printing apparatus will be described as an example.

  In this case, the liquid supply device includes a main tank that stores ink, and a liquid supply line that connects the main tank and the inkjet head in communication. In addition to valves and pumps, the liquid supply line is appropriately provided with a storage section such as a sub tank or an air trap tank.

  When the amount of ink in the storage unit decreases, ink is replenished from the main tank to the storage unit. Thereby, the liquid supply apparatus is maintained in a state in which ink can be smoothly supplied to the inkjet head. Further, the liquid supply device acquires and monitors the amount of ink supplied from the main tank to the reservoir (hereinafter referred to as “consumption amount” as appropriate), the remaining amount of ink in the main tank, and the like. .

  Conventionally, this consumption is acquired based on the ink flow rate. For example, the consumption is a value obtained by multiplying the valve opening time or the pump operation time by the ink flow rate. Further, when the valve opening time and the pump operation time per replenishment are constant, a value obtained by multiplying the number of ink replenishments by the ink replenishment amount per replenishment is used. However, even in this case, since the ink replenishment amount per replenishment is set based on the ink flow rate, the consumption amount is still acquired based on the ink flow rate.

  Further, the remaining amount of ink in the main tank is acquired by subtracting the consumption amount acquired as described above from the initial ink amount of the main tank. Therefore, the remaining amount of ink in the main tank is also acquired based on the ink flow rate (see, for example, Patent Documents 1 and 2).

JP 2005-199551 A JP 2006-188002 A

However, the conventional example having such a configuration has the following problems.
That is, since the viscosity of ink changes significantly according to its temperature, the flow rate of ink tends to fluctuate. For this reason, an error is likely to occur between the acquired consumption amount and the actually consumed ink amount. Also, the greater the ink temperature change, the greater the error between them. Furthermore, since the number of times the main tank can be replenished increases as the volume of the main tank increases, the error that occurs between the two increases further. As described above, the conventional liquid supply apparatus has a disadvantage that it is difficult to accurately obtain the ink consumption amount and the ink remaining amount in the main tank.

  Such inconvenience is not unique to the liquid supply apparatus applied to the ink jet printing apparatus, but is common to liquid supply apparatuses applied to various apparatuses.

  The present invention has been made in view of such circumstances, and a liquid supply device that can accurately acquire the remaining amount of liquid or the consumption amount of liquid in a main tank, and an ink jet printing apparatus including the same The purpose is to provide.

In order to achieve such an object, the present invention has the following configuration.
That is, the liquid supply apparatus of the present invention includes a main tank that stores liquid, a first support portion that is connected to one side portion of the main tank and supports the main tank so as to be rotatable about a horizontal axis, and the main tank. A second support part that supports the other side part opposite to one side part of the tank and maintains the main tank in a fixed posture, and a load sensor that measures a load that the second support part receives from the main tank And a control unit that obtains the weight of the liquid stored in the main tank based on the detection result of the load sensor.

  [Operation / Effect] According to the liquid supply apparatus of the present invention, the first and second support portions support one side and the other side of the main tank, respectively, so that the main tank is stably supported. be able to. The first and second support portions can receive the load from the main tank in a distributed manner. For this reason, the load which a load sensor measures can be made small compared with the total weight of a main tank, and it can prevent suitably that an overload is applied to a load sensor. As a result, the detection accuracy of the load sensor can be kept good. Furthermore, since the load sensor is provided only in the second support part and not provided in the first support part, the configuration can be simplified.

  Further, since the weight of the liquid does not change even if the temperature of the liquid changes, the accuracy of the detection result of the load sensor is not affected by the temperature change of the liquid. The control unit acquires the weight of the liquid stored in the main tank, that is, the weight in the tank, based on the detection result of the load sensor. According to the weight in the tank, the remaining amount of liquid and the amount of liquid consumed in the main tank can be obtained with high accuracy. In addition, according to the weight in the tank, the remaining amount of liquid in the main tank can be suitably acquired even when the liquid is replaced with a main tank that does not store a predetermined initial weight of liquid. Furthermore, according to the weight in the tank, the remaining amount of liquid in the main tank can be suitably managed even when the main tank is refilled without replacing the main tank.

  In this specification, the units of “remaining amount of liquid in the main tank” and “consumption amount of liquid” may be weight / mass or volume. In any case, the above-mentioned tank weight can be obtained with high accuracy.

  In the above-described invention, the control unit includes a first storage unit that stores in advance correspondence information indicating a relationship between the weight in the tank and the load received by the second support unit, and the correspondence information and the detection result. It is preferable to include a determination unit that determines the weight in the tank based on the determination result. Since the main tank is held in a fixed posture by the first and second support portions, the load received by the second support portion (that is, the load measured by the load sensor) corresponds to the weight in the tank. The control unit according to the present invention includes a first storage unit that stores correspondence information indicating a correspondence relationship between the weight in the tank and the load in advance, and a determination unit that determines the weight in the tank by referring to the correspondence information. Have. Therefore, the control unit can easily and accurately determine the weight in the tank.

  In the above-described invention, the second support portion supports the other side portion at the same height position as the horizontal axis, and the control portion includes dimensional information on the shape of the main tank, the main tank, Based on a first storage unit, a second storage unit that stores in advance position information regarding the relative position of the second support unit, the dimension information, the position information, and the detection result of the load sensor, It is preferable to include a calculation unit that calculates the weight in the tank. The relationship between the weight in the tank and the center of gravity of the main tank is specified based on the dimensional information. Further, if the position information is taken into account, the relationship among the three of the weight in the tank, the position of the center of gravity of the main tank, and the load received by the second support portion is specified. Here, assuming that the load received by the second support portion is known, the weight in the tank and the position of the center of gravity of the main tank are uniquely determined. In the present invention, the second storage unit stores dimension information and position information. In addition, the calculation unit refers to these dimension information and position information, and calculates the weight in the tank when the above-described three-way relationship is satisfied, using the load received by the second support unit as a detection result of the load sensor. Therefore, the weight in the tank can be suitably acquired according to the detection result of the load sensor.

  In the above-described invention, the main tank has a bottom surface whose gradient is changeable, the apparatus further includes a gradient detection unit that detects a gradient of the bottom surface of the main tank, and the calculation unit includes: Further, it is preferable to calculate the weight in the tank in consideration of the detection result of the gradient detection unit. According to this, the calculation unit can specify the shape of the main tank according to the gradient of the bottom surface based on the dimension information stored in the second storage unit and the detection result of the gradient detection unit. Therefore, even if the main tank is configured such that the gradient of the bottom surface can be changed, the calculation unit can appropriately calculate the weight in the tank.

  In the above-described invention, the main tank preferably has an inclined bottom surface. Even if the remaining amount of liquid in the main tank decreases, the liquid in the main tank can be consumed smoothly.

  In the above-described invention, the main tank has a deformable shape, stores a soft bag for storing liquid, the soft bag, and is supported by the first support portion and the second support portion. And a housing. Since the liquid is accommodated by the soft bag, the capacity of the main tank can be increased relatively easily. Moreover, since the housing | casing which accommodates this soft bag is provided, the 1st, 2nd support part can support a main tank appropriately.

  In the above-described invention, a storage unit that is provided on a liquid supply line that is connected to the main tank and that stores liquid, and a volume sensor that detects information related to the volume of the liquid in the storage unit, The control unit includes an outflow amount acquisition unit that acquires an outflow amount of the liquid flowing out from the main tank based on a detection result of the volume sensor, and a correction unit that corrects the weight in the tank by the outflow amount; Are preferably provided.

The “information related to the volume of the liquid in the reservoir” detected by the volume sensor is information that can acquire the volume of the liquid stored in the reservoir based on the information. This information is spatial information (static information) related to the length (m), area (m ² ), or volume (m ³ ) of the liquid in the reservoir or the reservoir itself. For example, it may be the liquid level height (liquid level) in the storage part, or the size of the storage part itself when the outer shape of the storage part can be deformed according to the volume of the stored liquid. May be. The detection result of such a volume sensor is influenced by the viscosity of the liquid compared to dynamic information (temporal information) such as the flow rate (m ³ / s) of the liquid and the flow velocity (m / s). Hard and accurate. In other words, even if the temperature of the liquid changes, the detection result of the volume sensor is unlikely to contain an error.

  The outflow volume acquisition unit acquires the outflow amount of the liquid flowing out from the main tank based on the detection result of the volume sensor. As described above, according to the present invention, the outflow amount is acquired based on the detection result of the volume sensor, separately from the weight in the tank. The remaining amount of liquid and the amount of liquid consumption in the main tank can be obtained with high accuracy also by this outflow amount.

  Further, the correction unit corrects the weight in the tank using the outflow amount. Therefore, the accuracy of the weight in the tank can be further increased.

  In the above-described invention, it is preferable that an output unit for outputting the weight in the tank is provided. According to this, the weight in the tank can be clearly shown to the user.

  In the above-described invention, the control unit further includes a usage amount acquisition unit that acquires a usage amount of liquid in each print job based on the weight in the tank acquired for each print job, and the output unit Preferably, the usage amount in each print job is output. According to this, the usage amount of the liquid can be clearly shown for each print job to the user. Here, the unit of “use amount of liquid” may be weight / mass or volume.

  An ink jet printing apparatus according to the present invention includes a liquid supply device according to any one of claims 1 to 8, a discharge unit that is connected to the liquid supply device and discharges the liquid supplied by the liquid supply device, And the liquid is an ink jet printing apparatus.

  [Operation / Effect] According to the ink jet printing apparatus of the present invention, since the liquid supply device described above is provided, the remaining amount of ink and the amount of ink consumed in the main tank can be obtained with high accuracy.

  The liquid supply apparatus of the present invention is provided on a main tank that stores liquid, a liquid supply line that is connected to the main tank, and stores the liquid. The liquid supply apparatus includes: a volume sensor that detects related information; and a control unit that acquires an outflow amount of the liquid flowing out from the main tank based on a detection result of the volume sensor.

[Operation / Effect] The “information related to the volume of the liquid in the reservoir” detected by the volume sensor is information based on which the volume of the liquid stored in the reservoir can be acquired. This information is spatial information (static information) related to the length (m), area (m ² ), or volume (m ³ ) of the liquid in the reservoir or the reservoir itself. The detection result of such a volume sensor is influenced by the viscosity of the liquid compared to dynamic information (temporal information) such as the flow rate (m ³ / s) of the liquid and the flow velocity (m / s). Hard and accurate.

  The control unit acquires the outflow amount of the liquid that has flowed out of the main tank based on the detection result of the volume sensor. According to this outflow amount, the remaining amount of liquid and the consumption amount of liquid in the main tank can be obtained with high accuracy.

  In the above-described invention, it is preferable that the liquid does not flow out from the storage portion when the liquid is allowed to flow into the storage portion. According to this, when acquiring the outflow amount, the control unit does not have to consider the outflow from the storage unit. Therefore, the control unit can easily acquire the outflow amount.

  In the above-described invention, the storage section can be expanded and deformed according to the volume of the stored liquid, the volume sensor detects the dimensions of the storage section, and the control section measures the dimensions of the storage section. It is preferable to acquire the outflow amount in accordance with an increase in the amount. Since the volume sensor detects the dimension of the reservoir itself, the accuracy of the detection result is not easily affected by the temperature change of the liquid. Therefore, the outflow amount can be obtained with high accuracy.

  In the above-described invention, the volume sensor includes a first dimension sensor that detects whether or not the dimension of the storage part has reached a first predetermined value, and the dimension of the storage part is greater than the first predetermined value. A second dimensional sensor that detects whether or not the second predetermined value is reached, and the control unit is configured so that the storage unit is based on a detection result of the first and second dimensional sensors. It is preferable that the supply of liquid to the storage unit is started when the value is less than the value, and the supply of liquid to the storage unit is terminated when the dimension of the storage unit reaches a second predetermined value. A volume sensor can be realized with a simple configuration including the first and second dimension sensors. Moreover, the outflow amount can be suitably acquired by linking the detection result of such a volume sensor and the supply timing of the liquid to the reservoir.

  In the above-described invention, it is preferable that an output unit for outputting the outflow amount is provided. According to this, the outflow amount can be clearly shown to the user.

  In the above-described invention, the control unit further includes a usage amount acquisition unit that acquires a usage amount of liquid in each print job based on the outflow amount acquired for each print job, and the output unit includes: The usage amount in each print job is preferably output. According to this, the usage amount of the liquid can be separately shown for each print job to the user. Here, the unit of “use amount of liquid” may be weight / mass or volume.

  An ink jet printing apparatus according to the present invention includes a liquid supply device according to any one of claims 10 to 15 and a discharge unit that is connected to the secondary side of the storage unit and discharges the liquid supplied from the storage unit. And the liquid is an ink jet printing apparatus.

  [Operation / Effect] Since the ink jet printing apparatus according to the present invention includes the liquid supply device described above, it is possible to accurately acquire the ink consumption and the ink remaining amount in the main tank.

  In addition, this specification also discloses the invention which concerns on the following liquid supply apparatuses.

  (1) In the liquid supply apparatus according to claim 7, the correction unit may detect the load sensor after replacement of the main tank, with the weight in the tank acquired when the main tank is replaced as an initial weight. A liquid supply apparatus that replaces the tank weight obtained based on the result with a value obtained by subtracting the outflow amount from the initial weight.

  According to the liquid supply apparatus described in (1) above, the correction unit can suitably correct the weight in the tank by the outflow amount. Therefore, the weight in the tank can be acquired with higher accuracy. The “outflow amount” is the outflow amount itself when the unit of the outflow amount is the same as the initial weight, and is a value obtained by converting the outflow amount into the unit of the initial weight when the unit is different.

  According to the liquid supply apparatus of the present invention, the weight in the tank of the liquid stored in the main tank is acquired based on the detection result of the load sensor. Thus, since the weight in a tank is acquired based on the load which a 2nd support part receives from a main tank, it is not influenced by the temperature change of a liquid. Therefore, according to the weight in the tank, the remaining amount of liquid and the consumption amount of liquid in the main tank can be obtained with high accuracy.

  Moreover, according to the liquid supply apparatus concerning this invention, the outflow amount which flowed out from the main tank to the storage part based on the detection result of a volume sensor is obtained. As described above, the outflow amount is acquired based on the volume of the ink in the reservoir, and thus is not easily affected by the temperature change of the liquid. Therefore, according to the outflow amount, the remaining amount of liquid and the consumption amount of liquid in the main tank can be obtained with high accuracy.

  Further, according to the ink jet printing apparatus according to the present invention, since the liquid supply device described above is provided, the remaining amount of ink and the amount of ink consumed in the main tank can be obtained with high accuracy.

1 is a schematic configuration diagram of an ink jet printing apparatus according to Embodiment 1. FIG. It is an external appearance perspective view of a main tank. It is an external perspective view of a sub tank It is a side view of a sub tank. It is a flowchart which supplies ink to a sub tank. FIG. 3 is a schematic configuration diagram of an ink jet printing apparatus according to a second embodiment. It is a figure which shows typically the flow of the ink in the principal part of a supply line. FIG. 8A is a plan view of the main part of the main tank 13, and FIG. 8B is a front view of the main part of the main tank. It is a schematic diagram of the main tank in case a liquid level is higher than the upper end of a bottom face. It is a schematic diagram of a main tank in case a liquid level is lower than the upper end of a bottom face.

1. Overall Configuration A first embodiment of the present invention will be described below with reference to the drawings. In this embodiment, a liquid supply apparatus applied to an ink jet printing apparatus will be described as an example. FIG. 1 is a schematic configuration diagram of an ink jet printing apparatus according to a first embodiment.

  The ink jet printing apparatus 1 includes an ink jet head 3. The inkjet head 3 has a plurality of nozzles (not shown) that can eject ink droplets. A printing paper 7 is disposed at a position facing the inkjet head 3. The inkjet head 3 and the printing paper 7 can be moved relative to each other by a moving mechanism (not shown). The ink jet printing apparatus 1 includes a print control unit 9 that controls the moving mechanism and controls the ejection of each nozzle of the ink jet head 3. The print control unit 9 ejects ink droplets from each nozzle while relatively moving the inkjet head 3 and the printing paper 7 based on a print job (information regarding a print command) received from the user. As a result, printing is performed on the printing paper 7. The ink jet head 3 corresponds to the ejection part in the present invention.

  The ink jet printing apparatus 1 includes a liquid supply device 11 that supplies liquid to the ink jet head 3. The liquid supply device 11 is roughly divided into a main tank 13 for storing ink and a supply line 15 for connecting the main tank 13 and the inkjet head 3 in communication. The main tank 13 functions as an ink supply source. The supply line 15 supplies ink from the main tank 13 to each inkjet head 3.

  On the supply line 15, a pump 17 and a sub tank 19 are provided. The pump 17 draws ink from the main tank 13 and sends the ink to the sub tank 19. The sub tank 19 temporarily stores ink therein. Each time the inkjet head 3 (nozzles) ejects ink droplets, the ink in the sub tank 19 is sucked and sent to the inkjet head 3. In this way, the sub tank 19 smoothly replenishes the ink jet head 3 with ink. The sub tank 19 corresponds to the storage section in the present invention.

  In addition, the liquid supply device 11 includes a load sensor 21 and a volume sensor 23. The load sensor 21 measures a load received from the main tank 13. The volume sensor 23 acquires the dimension of the sub tank 19 itself.

  Further, the liquid supply device 11 includes a supply device control unit 27 and an output unit 29. In addition to the results of the load sensor 21 and the volume sensor 23, a print job or the like is input to the supply device control unit 27. FIG. 1 illustrates an example in which a print job is input from the print control unit 9 to the supply device control unit 27.

  The supply device control unit 27 controls the pump 17 based on the detection result of the volume sensor 23. As a result, the ink amount in the sub tank 19 is maintained at an appropriate amount. The supply device control unit 27 acquires the weight of ink stored in the main tank 13 (hereinafter referred to as “tank weight”) based on the detection result of the load sensor 21. Further, the supply device control unit 27 acquires the amount of ink that has flowed out of the main tank 13 (hereinafter referred to as “flowing amount”) based on the detection result of the volume sensor 23. The supply device control unit 27 corresponds to the control unit in the present invention.

  Various commands and information are input to the output unit 29 from the supply device control unit 27. The output unit 29 outputs the above-described tank weight and the like. Examples of the output unit 29 include a display. Thereby, the user of the inkjet printing apparatus 1 can grasp | ascertain these information suitably.

  Below, it divides into the main tank 13, the sub tank 19, and the control part 27 for liquid supply apparatuses, and demonstrates in detail.

  2. Configuration related to the main tank 13

  FIG. 2 is an external perspective view of the main tank. The main tank 13 includes a soft bag 31 that stores liquid and a housing 32 that stores the soft bag 31. The flexible bag 31 is made of a flexible material that can be bent, and its shape can be easily deformed. Examples of the material of the flexible bag 31 include synthetic resins such as polyethylene. Ink is stored in the soft bag 31. The flexible bag 31 has a supply port 31a at the top thereof. The primary side of the supply line 15 is inserted into the soft bag 31 through the supply port 31a.

  The casing 32 is made of a material having a relatively high rigidity and has a strength that does not deform with the weight of ink. The material of the housing 32 is preferably a metal. The casing 32 has a substantially box shape with the upper part opened, and the flexible bag 31 can be accommodated in the casing from the upper part. The bottom surface 33 of the housing 32 is inclined. Therefore, when the flexible bag 31 is accommodated, the outer shape of the flexible bag 31 is deformed along the bottom surface 33 of the housing 32.

  Side portions 34 and 35 of the housing 32 facing each other are supported by a first support portion 37 and a second support portion 39, respectively. Hereinafter, for convenience of explanation, the side portion 34 is referred to as “one side portion 34”, and the side portion 35 opposite to the one side portion 34 is referred to as “other side portion 35”.

  The first support portion 37 is a rod-shaped object having a circular cross section, and is fixedly installed such that its axis P is parallel to the horizontal direction. The one side portion 34 of the housing 32 is provided with a plurality of connecting portions 34a in which through holes are formed. The 1st support part 37 is inserted in the through-hole of each connection part 34a. A bearing 38 is provided between the connecting portion 34 a and the first support portion 37. As a result, the first support portion 37 supports the one side portion 34 of the main tank 13 so as to be rotatable about the horizontal axis P.

  The other side portion 35 is provided with a flange portion 35a that projects in a substantially horizontal direction. The second support part 39 is a trapezoidal object having a flat upper surface. The above-described load sensor 21 is disposed on the upper surface of the second support portion 39. The flange portion 35 a is placed on the second support portion 39 via the load sensor 21. Note that the flange portion 35 a is only placed with its lower surface in contact with the load sensor 21, and is not connected to the load sensor 21 or the second support portion 39. The second support portion 39 is set so that the lower surface of the flange portion 35 a is at the same height position as the horizontal axis P of the first support portion 37. By these first and second support portions 37 and 39, the posture of the main tank 13 is kept constant.

  The load sensor 21 measures the load that the second support part 39 receives from the main tank 13. An example of the load sensor 21 is a load cell. The load sensor 21 outputs the detection result to the liquid supply device control unit 27.

3. Configuration Related to Subtank 19 FIG. 3 is an external perspective view of the subtank, and FIG. 4 is a side view of the subtank. The sub tank 19 is formed into a bag shape using a flexible sheet material. The material of the sub tank 19 is preferably a synthetic resin such as polyethylene. A supply line 15 is connected to the sub tank 19 so that ink can flow in and out.

  The sub tank 19 expands / contracts according to the volume (volume) of the stored ink. In FIG. 4, the subtank 19 in a contracted state is indicated by a solid line, and the subtank 19 in an expanded state is indicated by a dotted line. As shown in the drawing, the vertical dimension (hereinafter referred to as “height dimension”) D of the sub tank 19 varies with expansion / contraction of the sub tank 19.

  The volume sensor 23 described above includes a projecting piece 41, and a first dimension sensor 43 and a second dimension sensor 44 that can detect the projecting piece 41. The projecting piece 41 is provided at the center of the surface 19f of the sub tank 19 so as to project upward. The protruding piece 41 moves up and down in accordance with the fluctuation of the height dimension D.

  Examples of the first and second dimension sensors 43 and 44 include optical sensors. The first dimension sensor 43 includes a light emitting unit 43a and a light receiving unit 43b that are arranged to face each other with the protruding piece 41 interposed therebetween. The second dimension sensor 44 includes a light emitting unit 44a and a light receiving unit 44b that are similarly arranged.

  The first dimension sensor 43 is disposed at a position where the protruding piece 41 can be detected when the height dimension D is equal to or greater than the first predetermined value L. Further, the second dimension sensor 44 is disposed at a position where the protruding piece 41 can be detected when the height dimension D is equal to or greater than a second predetermined value H that is larger than the first predetermined value L. Thus, the first dimension sensor 43 detects whether or not the height dimension D has reached the first predetermined value L. Further, the second dimension sensor 44 detects whether or not the height dimension D has reached the second predetermined value H.

4). Configuration of Supply Device Control Unit 27 Refer to FIG. The supply device control unit 27 includes a supply line control unit 51, a first storage unit 53, a determination unit 55, an outflow amount acquisition unit 57, a correction unit 58, and a usage amount acquisition unit 59.

  The detection result of the volume sensor 23 is input to the supply line control unit 51. The supply line control unit 51 monitors the height dimension D of the sub tank 19 based on the detection result of the volume sensor 23. The supply line control unit 51 receives a print job from the print control unit 9. The supply line control unit 51 refers to the print job to determine whether printing is being performed, in other words, whether ink droplets are being ejected from the nozzles. Then, when the height dimension D of the sub-tank 19 becomes less than the first predetermined value L, the supply line control unit 51 drives the pump 17 on the condition that the ejection of ink droplets is stopped. Further, the supply line control unit 51 stops the pump 17 when the height dimension D of the sub tank 19 reaches the second predetermined value H.

  The first storage unit 53 stores in advance correspondence information indicating the relationship between the weight in the tank and the load received by the second support unit 39 from the main tank 13 (that is, the load measured by the load sensor 21). . This correspondence information is data obtained in advance by experiments or the like. The configuration of the correspondence information may be a table format or a function format.

  A detection result of the load sensor 21 is input to the determination unit 55. The determination unit 55 refers to the correspondence information stored in the first storage unit 53, and the weight in the tank associated with the detection result of the load sensor 21 (that is, the weight of the ink stored in the main tank 13). Is).

  The detection result of the volume sensor 23 is input to the outflow amount acquisition unit 57. The outflow amount acquisition unit 57 monitors the fluctuation of the height dimension D of the sub tank 19 based on the detection result of the volume sensor 23. Further, the outflow amount acquisition unit 57 receives the amount of ink flowing into the sub tank 19 when the height dimension D of the sub tank 19 increases from the first predetermined value L to the second predetermined value H (hereinafter referred to as “unit inflow appropriately”). Called “amount”) is preset. This unit inflow amount is a predetermined value obtained in advance by experiments or the like. Note that the unit of the unit inflow amount may be weight / mass or volume.

  Then, the outflow amount acquisition unit 57 multiplies the number of times the height dimension D of the sub-tank 19 increases from the first predetermined value L to the second predetermined value H by the unit inflow volume, that is, from the main tank 13. This is the amount of ink that has flowed into the sub tank 19.

  From time to time, the weight in the tank is input from the determination unit 55 and the outflow amount is input from the outflow amount acquisition unit 57 to the correction unit 58. The correction unit 58 corrects the weight in the tank based on the outflow amount. In the present embodiment, the correction unit 58 sets the tank weight acquired when the main tank 13 is replaced to “initial weight”. After the main tank 13 is replaced, a value obtained by subtracting the outflow amount from the initial weight is regarded as the tank internal weight. In other words, all the in-tank weights obtained after replacement of the main tank 13 are replaced with the difference between the initial weight and the outflow amount. Here, when the unit of the outflow amount is the same as the initial weight, the outflow amount is the outflow amount itself, and when it is different, the outflow amount is a value obtained by converting the outflow amount into a unit of the initial weight. The correction unit 58 outputs the corrected tank weight to the output unit 29.

  The usage amount acquisition unit 59 receives the corrected tank weight from the correction unit 58 and the print job. The usage amount acquisition unit 59 acquires the usage amount of ink in each print job based on the temporal transition of the weight in the tank and the timing at which the print job is executed. The usage amount acquisition unit 59 outputs the usage amount of ink in each print job to the output unit 29. Note that the unit of “amount of ink used” may be weight / mass or volume.

  The supply device control unit 27 described above includes a central processing unit (CPU) that executes various processes and operations, a RAM (Random-Access Memory) that is a work area for arithmetic processing, a fixed disk that stores various types of information, and the like. This is realized by such a storage medium.

5. Operation Next, the operation of the liquid supply apparatus 11 according to the first embodiment will be described. First, an operation for supplying ink from the main tank 13 to the sub tank 19 will be described. FIG. 5 is a flowchart for supplying ink to the sub tank.

<Step S1> Is the sub tank less than a first predetermined value?
The print control unit 9 performs printing on the print paper 7 by ejecting ink droplets from the nozzles based on the print job. The ink in the sub-tank 19 is sucked and sent to the inkjet head 3 by the amount of ejected ink droplets. By this operation, the amount of ink in the sub tank 19 gradually decreases, and the height dimension D of the sub tank 19 gradually decreases.

  Based on the detection result of the volume sensor 23, the supply line control unit 51 determines whether or not the height dimension D of the sub tank 19 is less than the first predetermined value L. If it is determined that the height dimension D of the sub tank 19 is less than the first predetermined value L, the process proceeds to step S2. Otherwise, the process of this step S1 is repeated. Accordingly, the supply line control unit 51 monitors the height dimension D of the sub tank 19.

<Step S2> Is ink droplet ejection stopped?
The supply line control unit 51 determines whether ink droplets are ejected from the nozzles based on the print job. If it is determined that ink droplet ejection has stopped, the process proceeds to step S3. Otherwise, the process of this step S2 is repeated. Thereby, the supply line control unit 51 waits until the ejection of ink droplets is stopped.

<Step S3> Drive Pump The supply line control unit 51 drives the pump 17. The pump 17 pumps the ink in the main tank 13 and sends it to the sub tank 19 side. As a result, the ink in the main tank 13 flows into the sub tank 19 through the supply line 15. At this time, since the ejection of ink droplets is stopped, the ink in the sub tank 19 does not flow out to the inkjet head 3.

<Step S4> Has the sub tank reached the second predetermined value?
The supply line control unit 51 determines whether or not the height dimension D of the sub tank 19 has reached the second predetermined value H based on the detection result of the volume sensor 23. If it is determined that the height dimension D of the sub tank 19 has reached the second predetermined value H, the process proceeds to step S5. Otherwise, the process of this step S4 is repeated. Accordingly, the supply line control unit 51 monitors the height dimension D of the sub tank 19.

<Step S5> Stop Pump The supply line control unit 51 stops the pump 17.

  Next, an operation for acquiring the weight in the tank will be briefly described. Here, the scene of exchanging the main tank 13 will be described.

  For replacement of the main tank 13, the used soft bag 31 is taken out from the housing 32 and a new soft bag 31 is accommodated in the housing 32. The load sensor 21 measures the load received by the second support part 39 and outputs it to the determination part 55. The determination unit 55 specifies the weight in the tank based on the detection result of the load sensor 21 and the correspondence information. The determination unit 55 outputs the determined in-tank weight to the correction unit 58. The correcting unit 58 uses the tank weight acquired at the time of ink replacement as the initial weight.

  After the ink in the main tank 13 is replaced, the processes in steps S1 to S5 described above are repeated, and the supply of ink to the sub tank 19 is repeated. Along with this, the remaining amount of ink in the main tank 13 gradually decreases, and the load received by the second support portion 39 also gradually decreases.

  Even in such a period after the ink replacement, the determination unit 55 determines the in-tank weight based on the detection result of the load sensor 21 and outputs the determined in-tank weight to the correction unit 58 as needed. In parallel with this, the outflow amount acquisition unit 57 acquires the outflow amount based on the detection result of the volume sensor 23 and outputs the acquired outflow amount to the correction unit 58. The correction unit 58 replaces the in-tank weight input from the determination unit 55 with the difference between the initial weight and the outflow amount. The correction unit 58 outputs the corrected tank weight to the output unit 29 and the usage amount acquisition unit 59. The usage amount acquisition unit 59 acquires the usage amount of ink in each print job based on the temporal transition of the corrected tank weight and the timing at which the print job is executed. The usage amount acquisition unit 59 outputs the usage amount of ink divided for each print job to the output unit 29. The output unit 29 displays the weight in the tank and the amount of ink used in each print job.

  Thus, according to the liquid supply device 11 and the ink jet printing apparatus 1 according to the first embodiment, the main tank 13 is supported by the first and second support portions 37 and 39, so that the main tank 13 is stabilized. Can be supported. In particular, the movable range of the main tank 13 is restricted to the range of rotational movement around the horizontal axis P by the first support portion 37. For this reason, the 2nd support part 39 can support the main tank 13 suitably, when the vertical downward load is received from the main tank 13.

  Moreover, since the load of the main tank 13 is distributed to the first and second support portions 37 and 39, it is possible to prevent the load sensor 21 from being overloaded. Further, even when an impact is applied to the load sensor 21 during ink replacement work or the like, the impact received by the load sensor 21 can be made relatively small. Therefore, the detection accuracy of the load sensor 21 can be kept good.

  Further, the load sensor 21 is provided only in the second support portion 39 and is not provided in the first support portion 37, and is single. Thus, since only one relatively expensive load sensor 21 is required, the liquid supply device 11 and the ink jet printing apparatus 1 can be configured at low cost.

  Further, since the weight of the ink does not change according to the temperature change of the ink, the accuracy of the detection result of the load sensor 21 is not affected by the temperature change of the ink. Since the weight in the tank is acquired based on the detection result of the load sensor 21 as described above, the remaining amount of ink and the ink consumption in the main tank 13 can be accurately acquired.

  Further, according to the weight in the tank, the remaining amount of ink in the main tank 13 even when the main tank 13 is replaced with the main tank 13 that does not store a predetermined initial weight of ink (a part of the ink is consumed). Can be suitably managed. Furthermore, according to the weight in the tank, the remaining amount of ink in the main tank 13 is preferably managed even when the main tank 13 is replenished (added) without replacing the main tank 13. can do.

  Further, since the main tank 13 is held in a fixed posture, the load received by the second support portion 39 changes depending on only the weight in the tank. Since the first storage unit 53 stores correspondence information indicating the correspondence between the two, the determination unit 55 can easily and accurately determine the weight in the tank.

  Further, since the flexible bag 31 is deformed along the inclined bottom surface 33 of the housing 32, it can be said that the bottom surface of the main tank 13 is substantially inclined. For this reason, even if the remaining amount of ink in the main tank 13 decreases, the supply line 15 can smoothly flow out the ink from the main tank 13. Further, the ink in the main tank 13 can be used up almost completely.

  In addition, since the main tank 13 includes the soft bag 31 for storing ink, the main tank 13 can be changed relatively easily, for example, by increasing the capacity of the ink in the main tank 13. In addition, since the main tank 13 includes the housing 32 that accommodates the flexible bag 31, the first and second support portions 37 and 39 can appropriately support the main tank 13.

  Further, the ink volume is less likely to change due to a change in ink temperature than the viscosity of the ink. Since the volume sensor 23 indirectly measures the volume of ink in the sub tank 19 by detecting the size of the sub tank 19 itself, the accuracy of the detection result of the volume sensor 23 is relatively affected by the temperature change of the ink. Hateful. Since the outflow amount is acquired based on the detection result of the volume sensor 23, the remaining amount of ink in the main tank 13 and the ink consumption amount can be acquired with high accuracy.

  Further, since the sub tank 19 is deformed according to the volume of ink stored, the volume sensor 23 can suitably acquire information related to the volume of ink in the sub tank 19.

  The detection result of the volume sensor 23 is also linked to the ink supply timing to the sub tank 19. As described above, the volume sensor 23 serves not only as the outflow amount acquisition unit 57 but also as a sensor used by the supply line control unit 51, so that the apparatus configuration can be simplified.

  Further, the supply line control unit 51 does not allow ink to flow out from the sub tank 19 when ink is flowing into the sub tank 19. Therefore, the outflow amount acquisition unit 57 can easily acquire the inflow amount without considering the outflow from the sub tank 19.

  Moreover, since the correction | amendment part 58 correct | amends the weight in a tank determined by the determination part 55 using the outflow amount acquired by the outflow amount acquisition part 57, the precision of the weight in a tank can be improved further.

  Further, since the usage amount acquisition unit 59 acquires the usage amount of ink divided for each print job, the running cost and the like of the inkjet printing apparatus 1 can be accurately managed.

  Further, since the output unit 29 displays the weight in the tank and the like, the remaining amount of ink in the main tank 13 and the ink consumption amount can be clearly shown to the user of the inkjet printing apparatus 1.

  Embodiment 2 of the present invention will be described below with reference to the drawings. In this embodiment, a liquid supply apparatus applied to an ink jet printing apparatus will be described as an example. FIG. 6 is a schematic configuration diagram of the ink jet printing apparatus according to the second embodiment. In addition, about the same structure as Example 1, detailed description is abbreviate | omitted by attaching | subjecting the same code | symbol.

1. Schematic Configuration The supply device 61 according to the second embodiment includes a supply line 63 that connects the main tank 13 and the inkjet head 3 in communication. The supply line 63 is branched into two parallel lines 63 a and 63 b between the pump 17 and the inkjet head 3. Sub tanks 71 and 81 are provided in the parallel lines 63a and 63b, respectively. Furthermore, on the parallel line 63a, on-off valves 73 and 75 are provided on the primary side and the secondary side of the sub tank 71, respectively. Similarly, on the parallel line 63b, on-off valves 83 and 85 are provided on the primary side and the secondary side of the sub tank 81, respectively. The sub tanks 71 and 81 correspond to the storage part in the present invention.

  The sub tanks 71 and 81 are provided with volume sensors 77 and 87, respectively. The volume sensors 77 and 87 are configured similarly to the volume sensor 23 described in the first embodiment.

  The supply device control unit 91 includes a supply line control unit 93, a second storage unit 95, a calculation unit 97, and an outflow amount acquisition unit 99. Since the rest is the same as that of the first embodiment, the description thereof is omitted. The supply device control unit 91 corresponds to the control unit in the present invention. Below, it divides into the supply line control part 93 and the outflow amount acquisition part 99, the 2nd memory | storage part 95, and the calculation part 97, and it demonstrates in detail, respectively.

2. Configuration of Supply Line Control Unit 93 and Outflow Amount Acquisition Unit 99 The supply line control unit 93 causes the inkjet head 3 to alternately supply ink from the sub tanks 71 and 81. That is, the sub tanks that supply ink to the inkjet head 3 are alternately switched between the sub tanks 71 and 81.

  FIGS. 7A and 7B are diagrams schematically showing the ink flow in the main part of the supply line. FIG. 7A shows a state when ink is supplied from the sub tank 71, and FIG. 7B shows a state when ink is supplied from the sub tank 81.

  In FIG. 7A, the supply line control unit 93 opens the on-off valve 75 and closes the on-off valve 85. Thereby, only the sub tank 71 can supply ink to the inkjet head 3, and the sub tank 81 cannot supply (ink cannot flow out). At this time, if the supply line control unit 93 determines that the height dimension D of the sub tank 81 is less than the first predetermined value L based on the detection result of the volume sensor 87, the supply line control unit 93 opens the on-off valve 83 and drives the pump 17. Let The on-off valve 73 is closed. Thereby, the ink sent by the pump 17 flows into the sub tank 81. FIG. 7A shows a state where ink is supplied to the sub tank 81. When it is determined that the height dimension D of the sub tank 81 has reached the second predetermined value H, the pump 17 is stopped and the on-off valve 83 is closed. Thereby, the replenishment of the ink to the sub tank 81 is ended.

  Thereafter, when the height dimension D of the sub tank 71 becomes less than the first predetermined value L, the release valve 75 is closed and the on-off valve 85 is opened. Thereby, the sub tank 81 supplies ink to the inkjet head 3 instead of the sub tank 71. Subsequently, the supply line control unit 93 opens the on-off valve 73 and drives the pump 17. As described above, the supply line control unit 93 causes the ink to flow into the sub tank 71 after preventing the ink from flowing out from the sub tank 71.

  As described above, the supply line control unit 93 performs control so that the operations shown in FIGS. 7A and 7B are repeated alternately.

  In response to the control as described above, the outflow amount acquisition unit 99 acquires the outflow amount based on the total number of times that the sub tanks 71 and 81 have been replenished with ink. In addition, it is preferable that the outflow amount acquisition unit 99 has a unit inflow amount corresponding to each of the sub tanks 71 and 81 separately. According to this, even when the deformation amount corresponding to the stored ink amount is not equal (varies) between the sub-tanks 71 and 81, the outflow amount can be obtained with high accuracy.

3. Configuration of Second Storage Unit 95 and Calculation Unit 97 The second storage unit 95 includes dimensional information regarding the shape of the main tank 13 and positional information regarding the relative positions of the main tank 13 and the first and second support units 37 and 39. Is remembered.

  A specific example is illustrated with reference to FIG. FIG. 8A is a plan view of the main part of the main tank 13, and FIG. 8B is a front view of the main part of the main tank 13. In addition, illustration of the 1st, 2nd support parts 37 and 39 grade | etc., Is abbreviate | omitted in FIG. Further, in FIGS. 8A and 8B, the width direction of the tank is clearly indicated by the x axis, the depth direction of the tank is clearly indicated by the y axis, and the height direction of the tank is clearly indicated by the z axis. These points are the same in FIGS. 9 and 10 described later.

  As shown in the figure, the main tank 13 has a substantially rectangular parallelepiped shape, but its bottom surface 13B is inclined over the width direction. The portion above the upper end j of the bottom surface 13B can be regarded as a rectangular parallelepiped.

  In the case of such a main tank 13, as shown in FIGS. 8A and 8B, the dimension information includes a width dimension (e), a length (b) half the width dimension, and a depth dimension ( i). The height difference (h1) between the lower end k of the bottom surface 13B and the upper end j of the bottom surface 13B is also included in the dimension information. Note that the dimension information is a known constant.

  The position information includes a distance (a) in the y direction between the horizontal axis P and the left side surface 13L of the main tank 13, and a distance (c) in the y direction between the horizontal axis P and the load sensor 21. The former is relative position information of the main tank 13 and the first support part 37, and the latter is relative position information of the first and second support parts 37 and 39. These position information are also known constants.

  The calculating unit 97 calculates the in-tank weight based on the dimension information and the position information stored in the second storage unit 95 and the detection result of the load sensor 21. The processing by the calculation unit 97 will be specifically described.

  Let the ink density be ρ and the gravitational acceleration be g. The weight in the tank is M, and the load measured by the load sensor 21 (hereinafter abbreviated as “load” where appropriate) is F. The liquid level height of ink (hereinafter, abbreviated as “liquid level” where appropriate) with the lower end k of the bottom as a reference (zero) is defined as h. The above-described height difference (h1) can be rephrased as the liquid level at the upper end j.

The in-tank weight M1 when the liquid level h is h1 is represented by the formula (1).
M1 = 1/2 * h1 * e * i * ρ (1)

  The symbol “*” indicates a multiplication symbol (the same applies to mathematical expressions described below).

At this time, the load F1 measured by the load sensor 21 is expressed by Expression (2).
F1 = M1 * g * (a + 2/3 * b) / c
= 1/2 * h1 * e * i * ρ * g * (a + 2/3 * b) / c (2)

  Therefore, when the load F is equal to F1, the in-tank weight M is M1. Further, when the load F is larger than F1, the liquid level h is higher than h1. When the load F is smaller than F1, the liquid level h is lower than h1. Hereinafter, the derivation of the in-tank weight M will be described separately for the case where the liquid level h is higher than h1 and the case where the liquid level h is lower than h1.

<When liquid level h is higher than h1>
Please refer to FIG. FIG. 9 is a schematic diagram of the main tank when the liquid level h is higher than h1. As shown in the figure, when the liquid level h is (h1 + h2), the in-tank weight M is expressed by the equation (3).
M = (1/2 * h1 + h2) * e * i * ρ (3)

  As shown in the figure, the center of gravity Gc of the ink in the main tank 13 is on a line segment connecting the center of gravity G1 of the ink below the upper end j and the center of gravity G2 of the ink above the upper end j. Further, the position of the center of gravity Gc is given by the area ratio of the triangle jkl and the quadrangle jlmn in FIG.

The area S1 of the triangle jkl is expressed by Expression (4).
S1 = e * h1 / 2 (4)

The area S2 of the quadrangle jlmn is expressed by Expression (5).
S2 = e * h2 (5)

A distance d1 between the center of gravity G1 and the left side surface 13L of the main tank 13 in the y direction is expressed by Expression (6).
d1 = 2/3 * b (6)

A distance dc in the y direction between the center of gravity Gc and the left side surface 13L of the main tank 13 is expressed by Expression (7).
dc = d1 + (b-d1) * S2 / (S1 + S2) (7)

The load F is expressed by Expression (8) using the tank internal weight M and the distance dc.
F = M * g * (a + dc) / c (8)

Substituting Equations (3) to (7) into Equation (8) and solving for h2, h2 is obtained as follows.
h2 = (- B ± (B 2 - 4AC) (1/2)) / (2 * A) ··· (9)
However, A, B, and C are as shown in equations (10) to (12), respectively.
A = 2 * (a + b) (10)
B = 2 * a * h1 + d1 * h1 + b * h1-2 * F * c / (e * i * ρ * g) (11)
C = 1/2 * (a + d1) * h1 ² -F * c / (e * i * ρ * g) * h1 (12)

Here, since h2 is a positive number, h2 is obtained by Expression (13).
^{h2 = (-B + (B 2} - 4AC) (1/2)) / (2 * A) ··· (13)

  By substituting h2 obtained by Expression (13) into Expression (3), the in-tank weight M is also obtained.

<When the liquid level is lower than h1>
Please refer to FIG. FIG. 10 is a schematic diagram of the main tank when the liquid level h is lower than h1. As shown in the figure, when the liquid level h is set to h3, the in-tank weight M is expressed by the equation (14).
M = 1/2 * h3 * e * h3 / h1 * i * ρ (14)

A distance dc in the y direction between the center of gravity Gc of the ink in the main tank 13 and the left side surface 13L of the main tank 13 is expressed by Expression (15).
dc = 2/3 * b * h3 / h1 (15)

The load F is expressed by Expression (16) using the tank internal weight M and the distance dc.
F = M * g * (a + dc) / c (16)

When Expression (14) and Expression (15) are substituted into Expression (16), Expression (17) is obtained.
F = λ * h3 ² * (a + 2/3 * b * h3 / h1) (17)
However, λ is as shown in equation (18).
λ = 1/2 * e / h1 * i * ρ * g / c (18)

  When a load F is given to the equations (17) and (18), h3 is obtained. Furthermore, the in-tank weight M is obtained by substituting h3 into the equation (14).

Specific numerical examples are shown below. First, each dimension information shall take the following numerical value.
Half length of width dimension: b = 0.15 [m]
Width dimension: e = 0.3 [m]
Depth dimension: i = 0.1 [m]
Height difference (liquid level at top j): h1 = 0.1 [m]

Each position information is assumed to have the following numerical values.
Distance in the y direction between the horizontal axis P and the main tank 13: a = 0.1 [m]
Distance in the y direction between the horizontal axis P and the load sensor 21: c = 0.5 [m]

The ink density ρ and the gravitational acceleration g are as follows.
Density: ρ = 1000 [kg / m ³ ]
Gravity acceleration: g = 9.8 [m / s ² ]

Under the conditions described above, the load F1 when the liquid level h is h1 is the following value.
F1 = 5.88 [N]

For example, when the load F is 34.3 [N], the liquid level h is higher than h1. In this case, h2 and tank weight M are as follows.
h2 = 0.1933 [m]
M = 7.3 [kg]

For example, when the load F is 3.920 [N], the liquid level h is lower than h1. In this case, the liquid level h3 and the tank weight M are as follows.
h3 = 0.08492 [m]
M = 1.082 [kg]

  As described above, according to the liquid supply device 61 and the inkjet printing apparatus 1 according to the second embodiment, the second storage unit 95 that stores the dimension information and the position information, the dimension information, the position information, and the detection result of the load sensor 21 are used. Since the calculation unit 97 for calculating the in-tank weight M is provided, the in-tank weight M can be suitably obtained. Further, even when the bottom surface 13B of the main tank 13 is inclined, the tank weight M can be suitably calculated by considering the center of gravity Gc of the tank weight M.

  Further, since the first and second support portions 37 and 39 support the main tank 13 at the height position, the load received by the second support portion 39 from the main tank 13 is independent of the height position of the center of gravity Gc. It is always a vertically downward load and does not include a horizontal component. For this reason, even if the position of the center of gravity Gc in the z direction is not specified, if the position of the center of gravity Gc in the y direction (specifically, the distance dc) is specified, the in-tank weight M is obtained.

  In addition, since the plurality of sub tanks 71 and 81 connected in parallel to the inkjet head 3 are provided, ink can be stably supplied to the inkjet head 3. Further, since the supply line control unit 93 alternately switches the sub tanks that supply ink to the inkjet head 3 between the sub tanks 71 and 81, it is possible to always supply ink to the inkjet head 3 by either of the sub tanks 71 and 81. it can. Therefore, the operation rate of the inkjet printing apparatus 1 can be increased.

  The present invention is not limited to the above-described embodiment, and can be modified as follows.

  (1) In each of the embodiments described above, the volume sensors 23, 77, 87 acquire the outflow amount by detecting the dimensions of the sub tanks 19, 71, 81 themselves. However, the present invention is not limited to this. For example, the volume may be changed to a volume sensor that detects the volume of the sub tank 71 itself or the volume of ink in the sub tank 71. In this case, the configuration and method of the volume sensor can be appropriately selected and changed.

  (2) In each of the above-described embodiments, the volume sensors 23, 77, 87 are targeted for detection of the sub tanks 19, 71, 81. However, the present invention is not limited to this. May be. As another storage part, an air trap tank, a buffer tank, etc. are illustrated, for example. The air trap tank is for degassing and defoaming air (dissolved gas) from the ink. The buffer tank is for temporarily storing ink.

  Here, the configuration and operation of a modification in which the air trap tank is a detection target of the volume sensor and the outflow amount is acquired based on the ink amount in the air trap tank will be specifically described.

  The air trap tank is provided on the common line 15 and between the main tank 13 and the sub tank 19. The air trap tank is provided with a liquid level sensor that detects the ink level in the air trap tank. Since the liquid level is information related to the volume of ink in the air trap tank, the liquid level sensor corresponds to the volume sensor in the present invention. On the common line 15, an air trap secondary side opening / closing valve is further provided between the air trap tank and the sub tank 19.

  When it is determined that the liquid level in the air trap tank has dropped to a relatively low predetermined value based on the liquid level sensor, the common line control unit 51 closes the air trap secondary side open / close valve to close the main tank. Ink is supplied from 13 to the air trap tank. The sub tank 19 can supply ink to the inkjet head 3 (nozzles) without any trouble even while the ink is being supplied from the main tank 13 to the air trap tank. Therefore, the supply line control unit 51 performs the above-described control regardless of whether ink droplets are being ejected from the nozzles.

  Various methods can be applied to supply ink from the main tank 13 to the air trap tank. For example, a water head difference between the main tank 13 and the air trap tank 13, pressure feeding to the air trap tank, evacuation (gas discharge) from the air trap tank, and the like are exemplified. Note that when the ink is supplied to the air trap tank, the air trap secondary side on-off valve is closed, so that the ink in the air trap tank does not flow out to the sub tank 19 side.

  Thereafter, based on the liquid level sensor, when it is determined that the liquid level of the air trap tank has risen to a relatively high predetermined value, the common line control unit 51 supplies ink from the main tank 13 to the air trap tank. Stop and open the air trap secondary valve. In order to stop supply to the air trap, an air trap primary side opening / closing valve may be further provided on the common line 15 between the main tank 13 and the air trap tank.

  The detection result of the liquid level sensor is also given to the outflow amount acquisition unit 57. The outflow amount acquisition unit 57 acquires the outflow amount based on the detection result, and outputs the acquired outflow amount to the correction unit 58.

  Even in such a modified example, when ink is supplied to the air trap tank, the ink is not allowed to flow out of the air trap tank, so that the outflow amount acquisition unit 57 can easily acquire the outflow amount. Further, since the outflow amount is acquired based on the volume of the ink in the air trap tank, it is hardly affected by the temperature change of the liquid. Therefore, according to this outflow amount, the remaining amount of ink in the main tank 13 and the ink consumption amount can be obtained with high accuracy. Furthermore, according to this modification, ink can be supplied to the air trap tank while supplying ink from the sub tank 19 to the inkjet head 3 (nozzles). Therefore, the operation rate of the printing inkjet printing apparatus 1 can be increased.

  In addition, in the modification mentioned above, although the liquid level sensor was used, it is not restricted to this. That is, any volume sensor that detects information related to the amount of ink in the air trap tank can be selected and changed as appropriate.

  Moreover, in the modification mentioned above, although the air trap tank provided between the main tank 13 and the sub tank was provided, it is not restricted to this. For example, the above-described modification can be applied even to a configuration including a buffer tank provided between the main tank 13 and the sub tank. Furthermore, it is not restricted to an air trap tank or a buffer tank, Even if it is the structure provided with another storage part, the modification mentioned above is applicable. In this case, the volume sensor according to the structure of the air trap tank, the buffer tank, and other storage units can be appropriately selected and changed.

  (3) In each of the above-described embodiments, the sub tanks 19, 71, 81 are inflated and deformed according to the volume of ink stored, but are not limited thereto. In other words, the subtank (hard case subtank) that does not expand and deform can be appropriately changed according to the volume of ink stored. In this case, the volume sensor can be appropriately changed according to the structure of the sub tank.

  (4) In the above-described embodiments, the main tank 13 whose bottom surface is inclined is illustrated, but the present invention is not limited thereto. That is, you may change into the main tank which has a flat bottom face. Moreover, in each Example mentioned above, although the bottom face of the main tank 13 inclined with the uniform gradient, it is not restricted to this. It can change suitably to the bottom face which combined the inclined surface or flat surface from which gradient differs.

  (5) In each of the above-described embodiments, the gradient of the bottom surface of the main tank is constant regardless of the weight in the tank, but is not limited thereto. For example, the main tank may be arbitrarily changed to a main tank capable of arbitrarily changing the gradient of the bottom surface or a main tank having a movable bottom surface.

  Here, even in the modification in which the gradient of the bottom surface of the main tank changes according to the weight in the tank, the weight in the tank and the load received by the second support portion 39 have a certain correspondence. That is, correspondence information between the two can be acquired in advance by experiments or the like. Therefore, even in such a modification, the tank internal weight can be suitably obtained by the first storage unit 53 and the determination unit 55 described in the first embodiment.

  Moreover, even if it is a modification in which the gradient of the bottom surface of the main tank is arbitrarily changed, the gradient of the bottom surface can be appropriately acquired by providing the gradient detection unit that detects the gradient. Here, the gradient of the bottom surface corresponds to the height difference h1 described in the second embodiment. Therefore, by providing the obtained gradient of the bottom surface to the calculation unit 97 described in the second embodiment, the calculation unit 97 can suitably calculate the in-tank weight M according to the amount of inclination of the bottom surface. Thus, even in the modification described above, the in-tank weight M can be obtained by combining the second storage unit 95 and the calculation unit 97 of the second embodiment with the gradient detection unit.

  (6) In each of the above-described embodiments, the liquid supply apparatuses 11 and 61 applied to the inkjet printing apparatus 1 are illustrated, but the present invention is not limited to this. That is, the liquid supply apparatuses 11 and 61 may be applied to various apparatuses. In each embodiment, ink is exemplified as the liquid handled by the liquid supply devices 11 and 61, but is not limited thereto. Depending on the device to which the liquid supply devices 11 and 61 are applied, the liquid to be handled can be changed as appropriate.

  (7) In each of the above-described embodiments, the main tank 13 is configured by the soft bag 31 and the housing 32, but is not limited thereto. The configuration of the main tank 13 can be selected and changed as appropriate.

  (8) In each embodiment described above, the load sensor 21 is disposed so as to be in direct contact with the main tank 13 (the flange portion 35a), but is not limited thereto. For example, a structure in which the load sensor 21 is disposed below the second support portion 39 and the second support portion 39 is placed on the load sensor 21 may be employed. Even in this modification, the load sensor can suitably measure the load that the second support part 39 receives from the main tank 13.

  (9) In each of the above-described embodiments, the first support portion 37 is single and is linked and connected to each connecting portion 34a. However, the present invention is not limited to this. For example, the first support portions may be changed to a plurality of divided first support portions, and each of the first support portions may be changed to be interlocked and connected to the single connecting portion 34a.

  (10) In each of the above-described embodiments, the correction unit 58 replaces the in-tank weight acquired after the replacement of the main tank 13 with the difference between the initial weight and the outflow amount, but is not limited thereto. For example, it is possible to select an appropriate process such as taking the average of the weight in the tank and the difference between the initial weight and the outflow amount and setting it as the corrected tank weight. Alternatively, the correction unit 58 may be omitted, and the output unit 29 may be directly output without correcting the in-tank weight acquired by the determination unit 55 / calculation unit 97. As described above, even with the in-tank weight acquired by the determination unit 55 and the calculation unit 97 after the ink replacement, the remaining amount of ink and the ink consumption in the main tank 13 can be accurately acquired.

  (11) For each of the above-described embodiments and each of the modified embodiments described in (1) to (10) above, further change the configuration as appropriate by replacing or combining the configurations with the configurations of other modified embodiments. Also good.

DESCRIPTION OF SYMBOLS 1 ... Inkjet printing apparatus 3 ... Inkjet head (discharge part)
DESCRIPTION OF SYMBOLS 11, 61 ... Liquid supply apparatus 13 ... Main tank 13B ... Bottom face of main tank 15, 63 ... Supply line 19, 71, 81 ... Sub tank (storage part)
21 ... Load sensor 23, 77, 87 ... Volume sensor 27, 91 ... Supply device control unit (control unit)
DESCRIPTION OF SYMBOLS 29 ... Output part 31 ... Soft bag 32 ... Case 37 ... 1st support part 39 ... 2nd support part 43 ... 1st dimension sensor 44 ... 2nd dimension sensor 51, 93 ... Supply line control part 53 ... 1st memory | storage part 55 ... Determination unit 57, 99 ... Outflow amount acquisition unit 58 ... Correction unit 59 ... Usage amount acquisition unit 95 ... Second storage unit 97 ... Calculation unit P ... Horizontal axis D ... Height dimension H ... First predetermined value L ... First 2 predetermined value
F… Load
M… weight in tank

Claims (17)

A liquid supply device,
A main tank for storing liquid;
A first support part connected to one side of the main tank and supporting the main tank so as to be rotatable about a horizontal axis;
A second support portion that supports the other side portion opposite to the one side portion of the main tank, and maintains the main tank in a fixed posture;
A load sensor for measuring a load received by the second support portion from the main tank;
Based on the detection result of the load sensor, a control unit for acquiring the weight in the tank of the liquid stored in the main tank;
A liquid supply apparatus comprising: The liquid supply apparatus according to claim 1,
The controller is
A first storage unit storing in advance correspondence information indicating a relationship between the weight in the tank and the load received by the second support unit;
A determination unit that determines the weight in the tank based on the correspondence information and the detection result;
A liquid supply apparatus comprising: The liquid supply apparatus according to claim 1,
The second support part supports the other side part at the same height position as the horizontal axis,
The controller is
Dimensional information relating to the shape of the main tank, and a second storage part that stores in advance position information relating to the relative positions of the main tank, the first support part, and the second support part,
Based on the dimension information, the position information, and the detection result of the load sensor, a calculation unit that calculates the weight in the tank;
A liquid supply apparatus comprising: The liquid supply apparatus according to claim 3.
The main tank has a bottom surface whose gradient can be changed,
The apparatus further includes a gradient detector that detects a gradient of the bottom surface of the main tank,
The calculation unit further calculates the weight in the tank in consideration of the detection result of the gradient detection unit. In the liquid supply apparatus in any one of Claims 1-3,
The main tank is a liquid supply apparatus having an inclined bottom surface. In the liquid supply apparatus in any one of Claims 1-5,
The main tank is
A flexible bag having a deformable shape and storing liquid;
A housing that houses the flexible bag and is supported by the first support portion and the second support portion;
A liquid supply apparatus comprising: The liquid supply apparatus according to any one of claims 1 to 6,
A storage section that is provided on a liquid supply line that is connected to the main tank, and stores liquid;
A volume sensor for detecting information related to the volume of liquid in the reservoir;
With
The controller is
Based on the detection result of the volume sensor, an outflow amount acquisition unit that acquires an outflow amount of the liquid that has flowed out of the main tank,
A correction unit for correcting the weight in the tank by the outflow amount;
A liquid supply apparatus comprising: In the liquid supply apparatus in any one of Claims 1-7,
The liquid supply apparatus provided with the output part which outputs the weight in the said tank. The liquid supply apparatus according to claim 8, wherein
The control unit further includes a usage amount acquisition unit that acquires the usage amount of the liquid in each print job based on the weight in the tank acquired for each print job.
The output unit is a liquid supply apparatus that outputs the usage amount in each print job. A liquid supply device according to claim 1 to 9,
A discharge unit that is connected to the liquid supply device and discharges the liquid supplied by the liquid supply device;
With
An ink jet printing apparatus, wherein the liquid is ink. A liquid supply device,
A main tank for storing liquid;
A storage section that is provided on a liquid supply line that is connected to the main tank, and stores liquid;
A volume sensor for detecting information related to the volume of liquid in the reservoir;
Based on the detection result of the volume sensor, a control unit for acquiring the outflow amount of the liquid that has flowed out of the main tank,
A liquid supply apparatus comprising: The liquid supply apparatus according to claim 11,
A liquid supply device that does not allow liquid to flow out of the storage section when liquid is allowed to flow into the storage section. The liquid supply device according to claim 11 or 12,
The storage part is inflatable and deformable according to the volume of liquid to be stored,
The volume sensor detects the size of the storage part,
The said control part is a liquid supply apparatus which acquires the said outflow amount according to the increase in the dimension of the said storage part. The liquid supply device according to claim 13,
The volume sensor is
A first dimension sensor for detecting whether or not the dimension of the storage part has reached a first predetermined value;
A second dimension sensor for detecting whether or not the dimension of the storage part has reached a second predetermined value larger than the first predetermined value;
With
The control unit starts supply of liquid to the storage unit when the storage unit is less than the first predetermined value based on the detection results of the first and second dimension sensors, and the size of the storage unit is A liquid supply device that terminates the supply of the liquid to the reservoir when the second predetermined value is reached. The liquid supply apparatus according to any one of claims 11 to 14,
The liquid supply apparatus provided with the output part which outputs the said outflow amount. The liquid supply apparatus according to claim 15, wherein
The control unit further includes a usage amount acquisition unit that acquires a usage amount of liquid in each print job based on the outflow amount acquired for each print job.
The output unit is a liquid supply apparatus that outputs the usage amount in each print job. A liquid supply device according to any one of claims 11 to 16,
A discharge unit that is connected to the secondary side of the storage unit and discharges the liquid supplied from the storage unit;
With
An ink jet printing apparatus, wherein the liquid is ink.

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