JP2007055256A - Inkjet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize driving of a conveyance means for conveying ink in a tube coupling an ink tank with a recording head by an embodiment depending on a dimensional value of the tube in an inkjet recorder. <P>SOLUTION: While a bubble is conveyed from a first detection position to a second detection position in an ink supply tube 11, a conveyance amount of a mixture of an ink and a bubble (conveyance amount of the ink) conveyed through the ink supply tube 11 is determined. A pump 12 is controlled to be driven according to the determined conveyance amount of the ink. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In the ink jet recording apparatus, the present invention relates to the dimensions corresponding to the tube connecting the ink tank and the recording head (for example, the tube diameter, length, tube volume, tube flow resistance (pressure loss)). The present invention relates to a technique for transferring at least one of ink and bubbles existing in the tube in a mode corresponding to the dimension corresponding value of the tube, regardless of variations.

  2. Description of the Related Art Conventionally, an ink jet recording apparatus including a tube supply type ink supply system is known. That is, this type of ink jet recording apparatus includes a recording head that performs recording on a recording medium by ejecting ink from ejection nozzles, a carriage that includes a sub tank that stores ink supplied to the recording head, and ink that is supplied to the sub tank. And a main tank for storing the water. This ink jet recording apparatus is configured to supply ink from a main tank to a sub tank via a tube when the ink in the sub tank decreases.

However, in the ink jet recording apparatus including the above-described tube supply type ink supply system, the viscosity of the ink accumulated in the ejection nozzles and the tubes of the recording head gradually increases. Thus, among such ink jet recording apparatuses, there is an ink jet recording apparatus that periodically performs a purging operation in order to discharge ink accumulated in the ejection nozzles and tubes of the recording head (for example, Patent Documents). 1).
Japanese Patent Laying-Open No. 2005-22167 (6th and 7th pages, FIG. 1)

  However, the ink jet recording apparatus as described above has the following problems. That is, the above-described tubes have variations in their dimension-corresponding values (for example, the inner diameter dimension, the length dimension, the inner volume of the tube, and the flow path resistance (pressure loss) in the tube) at the time of manufacture.

  For this reason, for example, in order to reliably prevent thickened ink or bubble-containing ink from remaining in the tube, although the tube internal volume may be smaller than the designed tube internal volume, It is conceivable that a larger amount of ink or bubble-containing ink than the designed tube inner volume is discarded outside the tube at the time of initial introduction (when the ink jet recording apparatus is first turned on).

  Further, for example, the diameter of the tube (the diameter in the tube) may be larger than the designed value. In this case, compared with the case where the diameter of the tube is a designed value, the flow resistance of the tube (in other words, the flow resistance (pressure loss) when the ink flows in the tube) becomes lower. However, during the purge operation to recover the discharge capacity of the injection nozzle, in order to reliably recover the discharge capacity of the injection nozzle, it is more appropriate than the flow resistance of the tube when the tube diameter is a design value. It is conceivable that ink is ejected from the ejection nozzle at a purge pressure assuming a case where the flow path resistance is high. Accordingly, in this case as well, an amount of ink exceeding the amount actually required is ejected (discarded).

  The present invention has been made in view of such problems, and an object of the present invention is to drive a transfer means for transferring ink existing in a tube connecting an ink tank and a recording head in an ink jet recording apparatus. An object of the present invention is to provide a technique that realizes a mode corresponding to a dimension corresponding value of a tube.

  An ink jet recording apparatus according to a first aspect made to solve the above-described problem includes a recording head, a main tank, a tube, a transfer unit, a transfer amount determination unit, and a drive unit.

  Here, the recording head has a sub tank for storing ink and an ejection nozzle, and selectively ejects ink in the sub tank from the ejection nozzle to record an image on a recording medium. The main tank stores ink supplied into the sub tank. The tube connects the sub tank and the main tank. The transfer means transfers ink existing in the tube. The transfer amount determining means determines at least one transfer amount of the mixture of ink and bubbles transferred through the tube while the bubbles move from the first detection position to the second detection position in the tube. The drive means performs drive control of the transfer means based on the transfer amount determined at least once by the transfer amount determination means.

  The transfer amount determined by the transfer amount determining means corresponds to the volume (size corresponding value) between two detection positions in the tube. Therefore, in the present invention, the drive means performs drive control of the transfer means corresponding to the dimension corresponding value of the tube.

  Therefore, according to the present invention, for example, in order to prevent the thickened ink or bubble-containing ink from remaining in the tube as much as the drive control of the transfer means corresponding to the dimension corresponding value of the tube is realized. Thus, it is possible to reduce the amount of wasted ink that is discarded outside the tube at the time of initial introduction or the like, and the amount of wasted ink that is ejected from the ejection nozzle to recover the ejection capability of the ejection nozzle.

  According to the ink jet recording apparatus of the present invention, the amount of ink ejected from the ejection nozzle is measured at least once while the bubble moves from the first detection position to the second detection position in the tube. Discharge amount measurement means may be provided.

  In this case, the transfer amount determination means moves the tube while the bubble moves from the first detection position to the second detection position in the tube based on the ink amount measured at least once by the discharge amount measurement means. It is conceivable to determine the transfer amount of the mixture of ink and air bubbles transferred through the at least one time.

If comprised in this way, the determination of the said transfer amount will be correctly performed only the part for which the determination of the transfer amount by a transfer amount determination means is performed based on the ink amount discharged from an ejection nozzle.
According to the ink jet recording apparatus of the present invention, as described in claim 3, the mixture of ink and bubbles transferred through the tube while the bubbles move from the first detection position to the second detection position in the tube. There may be provided an initial amount storage means for storing an initial transfer amount that is a transfer amount and is preset based on the initial dimensions of the tube.

  Here, the initial transfer amount is an initial value of the transfer amount described above. As a specific example of the initial transfer amount, for example, a first detection position in the tube that is assumed from a dimension corresponding value in the design of the tube or a dimension corresponding value measured when the ink jet recording apparatus is manufactured. The amount of transfer of the mixture of ink and bubbles transferred through the tube while the bubbles move from the first to the second detection position can be considered.

  In the case of claim 3, before the actual transfer amount is determined by the transfer amount determination means, the transfer amount determination means transfers the initial transfer amount stored in the initial amount storage means by the transfer amount determination means. The driving means determines the amount and controls the driving of the transferring means based on the initial transfer amount.

  In this way, the drive means can be used in the tube before the actual determination of the transfer amount of the mixture of ink and bubbles transferred through the tube while the bubble moves between the two detection positions. It becomes possible to perform drive control of the transfer means corresponding to the dimension corresponding value.

  According to a fourth aspect of the present invention, the ink jet recording apparatus may further include a corresponding value determining unit that determines a dimension corresponding value of the tube based on the transfer amount determined at least once by the transfer amount determining unit. . In this case, the driving unit may perform driving control of the transfer unit based on at least one dimension corresponding value determined by the corresponding value determining unit.

In this way, drive control of the transfer means corresponding to the dimension corresponding value of the tube is suitably realized.
Moreover, in the aspect described in claim 4, the aspect described in claim 5 may be adopted. In other words, the ink jet recording apparatus according to claim 5 further includes an initial value storage means for storing an initial dimension corresponding value set in advance based on the initial dimension of the tube.

  Here, the initial dimension correspondence value is an initial value of the above-described dimension correspondence value. As a specific example of the initial dimension correspondence value, for example, a design dimension correspondence value or the inkjet recording apparatus is manufactured. Measured dimension values can be considered.

  Further, in claim 5, before the corresponding dimension determining unit actually determines the dimension corresponding value at least once, the corresponding value determining unit determines the initial dimension corresponding value stored in the initial value storing unit as the corresponding value determining unit. The driving unit controls the driving of the transfer unit based on the initial dimension corresponding value.

  According to this configuration, the driving means can transfer the transfer means corresponding to the dimension corresponding value of the tube even before the dimension corresponding value of the tube is actually determined based on the transfer amount determined by the transfer amount determining means. It becomes possible to perform drive control.

  In the present invention, as described in claim 6, the transfer amount determining means may repeatedly determine the transfer amount. In this case, the inkjet recording apparatus of the present invention includes a transfer amount storage unit that stores a plurality of transfer amounts repeatedly determined by the transfer amount determination unit, and an average value of at least two transfer amounts stored by the transfer amount storage unit. Average value determining means for determining In this case, it is conceivable that the drive means performs drive control of the transfer means based on the average value determined by the average value determination means.

  In the case of the sixth aspect, each of the plurality of transfer amounts determined by the transfer amount determining means corresponds to the volume of the tube (corresponding to the dimension). There is a high possibility that such an average value of the transfer amount corresponds more accurately to the actual dimension corresponding value of the tube than the individual transfer amount determined by the transfer amount determining means.

  Therefore, in this case, the transfer means corresponding to the actual dimension corresponding value of the tube more accurately than the case where the drive control of the transfer means is performed only based on the individual transfer amounts determined by the transfer amount determination means. The possibility of realizing drive control is increased.

  In the aspect described in claim 6, the aspect described in claim 7 may be adopted. That is, in the ink jet recording apparatus according to claim 7, as a transfer amount of a mixture of ink and bubbles transferred through the tube while the bubbles move from the first detection position to the second detection position in the tube. And an initial amount storage means for storing a preset initial transfer amount based on the initial dimension of the tube.

  In the case of claim 7, the average value determining means stores the transfer amount storage means when the transfer amount storage means stores one or more transfer quantities but is less than two or more predetermined numbers. An average value of at least one transfer amount and the initial transfer amount stored in the initial amount storage means is determined. Further, the drive means performs drive control of the transfer means based on the average value.

  In this way, the actual dimensions of the tube can be obtained even before determining the number of transfers of the mixture of ink and bubbles transferred through the tube while the bubble moves between the two detection positions. The possibility of realizing the drive control of the transfer means corresponding to the corresponding value relatively accurately is increased.

  In the aspect described in claim 6 or claim 7, the aspect described in claim 8 may be adopted. That is, in the ink jet recording apparatus according to the eighth aspect, an average value storage unit that stores the average value determined by the average value determination unit, a latest transfer amount is determined by the transfer amount determination unit, and the transfer amount storage unit A deviation judging means for judging whether or not a deviation between the latest transferred quantity and the average value stored in the average value storing means is a value outside a predetermined range when the latest transferred quantity is stored; .

  Here, in claim 8, when the deviation determining means determines that the deviation is outside the predetermined range, the average value determining means is the latest transfer amount stored in the transfer amount storage means. And the average value storage means stores the determined average value as an update value of the average value stored so far by the average value storage means.

  Further, in claim 8, when the deviation determining means determines that the deviation is not outside the predetermined range, the average value determining means is the average stored in the average value storing means until now. The value is determined as the average value used when the drive means controls the transfer means.

  In this case, the average value used when controlling the transfer means is changed only when the deviation between the latest transfer amount determined by the transfer amount determination means and the average value stored by the average value storage means is relatively large. Therefore, the control process executed by the drive unit is simplified as compared with the case where the average value is changed each time the latest transfer amount is determined by the transfer amount determination unit.

  In the present invention, as described in claim 9, the transfer amount determining means may repeatedly determine the transfer amount. In this case, the ink jet recording apparatus of the present invention is determined by the corresponding value determining means and the corresponding value determining means for determining the dimension corresponding value of the tube based on each of the plurality of transfer amounts repeatedly determined by the transfer amount determining means. Corresponding value storage means for storing the plurality of dimension correspondence values and an average value determination means for determining an average value of at least two dimension correspondence values stored by the correspondence value storage means may be provided. In this case, it is conceivable that the drive means performs drive control of the transfer means based on the average value determined by the average value determination means.

  In the case of claim 9, the average value determined by the average value determining means, which is the average of the tube dimension corresponding values, is the actual dimension of the tube rather than the respective tube dimension corresponding values determined by the corresponding value determining means. There is a high possibility that the corresponding value corresponds accurately.

  Therefore, in this case, the actual dimension correspondence value of the tube can be handled more accurately than when the drive means is controlled based only on the respective dimension correspondence values of the tube determined by the correspondence value determining means. The possibility of realizing the drive control of the transfer means is increased.

  In the aspect described in claim 9, the aspect described in claim 10 may be adopted. That is, the ink jet recording apparatus according to a tenth aspect includes an initial value storage unit that stores a preset initial dimension corresponding value based on the initial dimension of the tube.

  In the case of claim 10, when the average value determining means stores the number of dimension correspondence values stored in the correspondence value storage means but is less than two or more predetermined numbers, the correspondence value storage means An average value of at least one dimension correspondence value stored and the initial dimension correspondence value stored by the initial value storage means is determined. Further, the drive means performs drive control of the transfer means based on the average value.

  In this way, based on a large number of transfer amounts determined by the transfer amount determining means, even before the actual number of tube dimensional correspondence values is actually determined, it is compared with the actual dimensional correspondence values of the tubes. There is a high possibility that the drive control of the transfer means corresponding to the accuracy will be realized.

  In the aspect described in claim 9 or 10, the aspect described in claim 11 may be adopted. That is, in the ink jet recording apparatus according to claim 11, the average value storage means for storing the average value determined by the average value determination means, and the latest dimension corresponding value is determined by the corresponding value determination means, and the corresponding value storage means Is a deviation for determining whether a deviation between the latest dimension correspondence value and the average value stored by the average value storage means is a value outside a predetermined range when the latest dimension correspondence value is stored. Determination means.

  Here, in claim 11, when the deviation determining means determines that the deviation is a value outside the predetermined range, the average value determining means is the latest dimension correspondence stored in the corresponding value storage means. The average value of at least two dimension-corresponding values including the value is determined, and the average value storage means stores the determined average value as an update value of the average value stored up to now by the average value storage means. .

  Further, in claim 11, when the deviation determining means determines that the deviation is not a value outside the predetermined range, the average value determining means is the average stored in the average value storing means until now. The value is determined as the average value used when the drive means controls the transfer means.

  In this case, the average value used when controlling the transfer means only when the deviation between the latest dimension correspondence value determined by the corresponding value determination means and the average value stored by the average value storage means is relatively large. The control process executed by the driving unit is simplified by the amount of change compared to the case where the average value is changed each time the latest dimension corresponding value is determined by the corresponding value determining unit.

  According to the twelfth aspect of the present invention, the drive means determines at least the waste transfer amount of the mixture of ink and bubbles existing in the tube based on the transfer amount determined at least once by the transfer amount determination means. At the same time, the drive means may be controlled so that the waste transfer amount of the mixture is discarded from the tube.

  Further, according to the present invention, in the present invention, the driving means determines at least the waste transfer amount of the mixture of ink and bubbles existing in the tube based on the average value determined by the average value determining means. Further, the drive control of the transfer means may be performed so that the waste transfer amount of the mixture is discarded from the tube.

  According to the fourteenth aspect of the present invention, in the present invention, the driving means determines at least a waste transfer amount of the mixture of ink and bubbles existing in the tube based on the dimension corresponding value determined by the corresponding value determining means. At the same time, the drive means may be controlled so that the waste transfer amount of the mixture is discarded from the tube.

In these cases, at least the amount of wasted ink discarded from the inside of the tube can be reduced by the amount determined so that the “discarded transfer amount” corresponds to the dimension corresponding value of the tube.
In the present invention, the dimension-corresponding value is calculated from the inner diameter of the portion from the first detection position to the second detection position of the tube (hereinafter also simply referred to as “tube inner diameter”) and the first detection position of the tube. One of the flow path resistance (pressure loss) (hereinafter also simply referred to as “tube flow path resistance”) when the ink flows in the portion up to the second detection position may be used.

  In this case, as described in claim 15 dependent on claim 4 or claim 5, the driving means is for recovering the discharge capability of the injection nozzle based on the dimension corresponding value determined by the corresponding value determining means. While determining the pressure which should be applied to the ink which exists in a tube, you may perform drive control of the transfer means corresponding to this pressure.

  Further, in this case, as described in claim 16 depending on any one of claims 9 to 11, the driving means is configured to discharge the ejection nozzle based on the average value determined by the average value determining means. The pressure to be applied to the ink existing in the tube for recovery may be determined and drive control of the transfer means corresponding to the pressure may be performed.

As described above, the transfer amount determined by the transfer amount determination means corresponds to the volume between the two detection positions in the tube.
Here, for example, from the length dimension of the portion from the first detection position to the second detection position in the tube (hereinafter also simply referred to as “tube length”), or from the first detection position on the inner wall surface of the tube. Let us assume a situation in which the surface roughness (hereinafter also simply referred to as “tube roughness”) of the portion up to the second detection position can be assumed to be the same predetermined value regardless of the difference in tubes.

  In this case, the tube inner diameter can be determined as the dimension corresponding value based on the transfer amount determined by the transfer amount determining means. If the tube inner diameter, tube length, and tube roughness are clear, the tube flow resistance can also be determined as the dimension-corresponding value.

  And, for example, when the pressure to be applied to the portion of the injection nozzle is set as a specified value during the purge operation for recovering the discharge capacity of the injection nozzle, based on the specified value and the tube flow path resistance, It is possible to determine the pressure to be applied to the ink present in the tube.

  Therefore, in the case of the fifteenth and sixteenth aspects, the “pressure to be applied to the ink existing in the tube for recovering the discharge capability of the ejection nozzle” is a value corresponding to the dimension of the tube (“tube inner diameter” or “tube flow path resistance”). )), It is possible to reduce the amount of wasted ink ejected from the ejection nozzle in order to recover the ejection capability of the ejection nozzle.

  The ink jet recording apparatus according to the present invention is the ink jet recording apparatus according to the seventeenth aspect, wherein the mixture of ink and bubbles transferred through the tube before the bubbles move from the first detection position to the second detection position in the tube. There may be provided a judging means for judging whether or not the amount of the transport has reached or exceeded a predetermined amount.

  In this case, before the bubble moves from the first detection position to the second detection position in the tube by the determination means, the transfer amount of the mixture transferred through the tube is equal to or more than the predetermined amount. When it is determined that the transfer amount is determined, the transfer amount determination unit excludes the transfer amount that is equal to or greater than the predetermined amount from the transfer amount determined by the transfer amount determination unit.

  In this way, if the bubble in the tube detected at the first detection position is not a bubble that moves inside the tube due to, for example, ink being transferred to the outside of the tube, Based on the movement of “the air bubbles in the tube detected at the first detection position”, it is possible to prevent the transfer amount determining means from determining the transfer amount.

  In the ink jet recording apparatus of the present invention, as described in claim 18, the first detection position is set near the end of the tube on the main tank side, while the second detection position is set on the sub tank in the tube. It may be set near the end of the side.

  In this way, the drive control of the transfer means corresponding to the overall dimension value of the tube is realized by the amount that the distance between the first detection position and the second detection position is close to the actual length of the tube. It becomes easy to be done.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[Description of Overall Configuration of Inkjet Recording Apparatus 1]
FIG. 1 is an external perspective view of an ink jet recording apparatus 1 suitable for applying the present invention. FIG. 2 is a cross-sectional view of the inkjet recording apparatus 1.

  The ink jet recording apparatus 1 is a so-called multi function device (MFD) having a printer function, a copy function, a scanner function, a facsimile function, and the like, and has a sheet-like form such as paper or plastic film as a recording medium. Paper is used. The inkjet recording apparatus 1 can perform monochrome image recording in the facsimile function, and can perform color and monochrome image recording in the printer function and the copy function.

  As shown in FIG. 1 and FIG. 2, the inkjet recording apparatus 1 has a scanner 2 provided on the upper part of a case 1a, and the recording (image) on the recording paper 40 in the various functions described above at the lower part (upper part in the case 1a). A recording unit 7 is provided for performing (formation).

  As shown in FIG. 2, a paper feeding device 30 is provided in the lower part of the case 1a. Further, a box-shaped metal frame 5 is disposed behind the case 1 a and above the paper feeding device 30. The frame 5 has a substantially rectangular parallelepiped shape that is long in the left-right direction, and is fixed inside the case 1a.

  A recording unit 7 is disposed in the upper part of the frame 5. The recording unit 7 includes a carriage 4a mounted with a recording head 4 for performing printer image recording, and can move back and forth (main scanning direction) and other mechanisms. In the recording unit 7, the carriage 4 a is controlled by a control device 110 (not shown in FIG. 2, see FIG. 6) composed of a CPU or the like, so that the recording head 4 is also scanned by reciprocating left and right. The recording head 4 records an image on a recording paper 40 that is stopped below the recording head 4 by ejecting ink from the ejection nozzles 14a (not shown in FIG. 2; see FIG. 3A) during this scanning. .

  A maintenance unit (not shown) is mounted at a position corresponding to the standby position of the carriage 4a in the recording unit 7. In the maintenance unit portion, a wiping operation for wiping the nozzle surface of the recording head 4 with a blade, a purge operation for forcibly removing dust, air, and solidified ink from the ejection nozzle 14a, a flushing operation, etc. Various maintenance operations are performed.

  In front of the case 1a are four ink cartridges 13 (not shown in FIG. 2; see FIG. 3) each containing ink of four colors (black, cyan, magenta, yellow) for recording a full-color image. It is stored. These ink cartridges 13 are configured to be detachable, and when the ink is replenished, the ink cartridges 13 are replaced. The ink cartridge 13 corresponds to a main tank.

  The ink accommodated in each ink cartridge 13 is configured to be supplied to the recording head 4 through four ink supply tubes 11 that connect each ink cartridge 13 and the recording head 4. These ink supply tubes 11 are supported so as to be able to follow the reciprocating motion of the carriage 4a.

  Further, a conveyance path 5 a for guiding the recording paper 40 from the rear of the paper feeding device 30 to the recording unit 7 is formed behind the frame 5. The recording unit 7 includes a conveyance roller 7a at a position adjacent to the exit of the conveyance path 5a, and a discharge roller 7b at a position where the recording paper 40 on which an image is recorded is discharged. The transport roller 7a rotates in response to the rotational driving force of a paper transport motor 123 (not shown in FIG. 2, see FIG. 6).

  The paper feeding device 30 includes a paper feeding cassette 3 that is inserted and set from the opening 1b of the case 1a. The sheet cassette 3 is provided with a sheet storage unit 3a for storing the stacked recording sheets 40. When the sheet supply cassette 3 is inserted into the case 1a, the recording sheet 40 in the sheet storage unit 3a is stored in the case 1a. It is arranged in the back.

  Then, the recording paper 40 stacked on the uppermost layer of the paper storage unit 3a is sent to the recording unit 7 through the conveyance path 5a as the paper feed roller 8 rotates. The paper feed roller 8 is rotatably held at the tip of a long arm 10 that is pivotally supported by the drive shaft 9, and the drive shaft 9 is not shown in FIG. 6), the rotation is transmitted and the rotation is transmitted.

  An operation panel 6 including various operation buttons and a liquid crystal panel is provided on the upper front surface of the inkjet recording apparatus 1. The operation panel 6 allows the user to select each mode such as the printer mode, copy mode, scanner mode, and facsimile mode in the inkjet recording apparatus 1, set various setting items in various modes, and need a facsimile number and the like. Items can be entered and the operating status and communication history can be confirmed. Further, by operation of the operation panel 6 by the user, it is possible to perform relatively high-pressure ink ejection through the ejection nozzle 14a (purging operation) in order to recover the ejection capacity of the ejection nozzle 14a.

[Description of ink supply mechanism]
3A and 3B are explanatory views showing a schematic configuration of the ink supply mechanism of the ink jet recording apparatus 1. FIG. 3A is a diagram schematically showing a side cross section of the ink supply mechanism, and FIG. FIG.

  The ink supply mechanism includes four recording heads 4 (FIG. 3) corresponding to magenta (M), cyan (C), yellow (Y), and black (K) inks provided on the carriage 4a of the recording unit 7. This is a mechanism for supplying ink from the corresponding ink cartridge 13 to (b). As shown in FIG. 3A, the sub-tank 14 provided in the recording head 4 corresponding to each color ink and the ink cartridge 13 for each color ink are in the middle of the ink supply tube 11 and the ink supply tube 11. It communicates with the pump 12 provided in the. That is, an ink supply tube 11 and a pump 12 are provided corresponding to each of the four recording heads 4. In this embodiment, each pump 12 is provided in the vicinity of the end of each ink supply tube 11 on the ink cartridge 13 side. The pump 12 corresponds to a transfer unit.

  In the vicinity of the sub tank 14 side of the pump 12 in the ink supply tube 11 (first detection position), a bubble detection device 11a capable of detecting bubbles in the ink supply tube 11 is installed. Further, a bubble detector 11b capable of detecting bubbles in the ink supply tube 11 is installed in the vicinity of the sub tank 14 (second detection position) in the ink supply tube 11. From the viewpoint of more accurately grasping the internal volume of the ink supply tube 11, the first detection position is preferably closer to the pump 12 (in other words, the ink cartridge 13), and the second detection position is preferably the sub tank 14. The closer it is to the better. The bubble detection device 11a and the bubble detection device 11b are electrically connected to a control device 110 described later. In addition, as a structure of the bubble detection apparatus 11a and the bubble detection apparatus 11b, the structure (optical detection apparatus) which detects the presence or absence of a bubble by detecting the state which light permeate | transmits the ink supply tube 11 with a photo sensor, or ink A configuration (electric resistance detection device) that continuously detects the electrical resistance value of the supply tube 11 and detects the presence or absence of bubbles based on a change in the resistance value is conceivable. However, since these structures are all in accordance with known techniques, detailed description thereof is omitted here.

  The recording head 4 includes a sub-tank 14 for storing ink ejected from the ejection nozzles 14a provided on the lower nozzle surface, and a valve unit 15 for opening or closing the sub-tank 14 to the atmosphere. The sub tank 14 and the valve unit 15 communicate with each other via a gas permeable membrane 15d which is a selectively permeable membrane that allows air to pass but does not allow ink to pass. Thus, when the valve unit is opened to the atmosphere, only air flows between the sub tank 14 and the valve unit 15, and ink does not leak from the sub tank 14 to the valve unit 15.

  The valve unit 15 includes an upper large-diameter portion 15f and a small-diameter vent hole 15e provided in the lower portion. A valve 15b, in which a large-diameter valve body and a small-diameter rod are integrally formed, is accommodated in the large-diameter portion 15f so as to be movable up and down. Further, a packing 15c which is an O-ring for sealing is interposed between the lower end surface side of the valve body of the valve 15b and the upper end surface side of the vent hole 15e. The valve 15b is always pressed downward by a spring 15a such as a coil spring provided in the large diameter portion 15f. In this state, the packing 15c is pressed by the valve body of the valve 15b and the lower end surface of the large diameter portion 15f, and the valve is closed. At this time, the rod of the valve 15b extends to the vicinity of the lower end opening of the vent hole 15e. On the other hand, when the release rod 16 provided at the standby position of the recording head 4 rises and presses the rod of the valve 15b upward against the urging force of the spring 15a, the valve body of the valve 15b is separated from the packing 15c. Then, the valve is opened, that is, the atmosphere is released.

  The pump 12 is provided in the middle of the ink supply tube 11. The pump 12 supplies ink from the ink cartridge 13 to the sub tank 14 of the recording head 4 (hereinafter referred to as ink supply direction), and returns the ink from the sub tank 14 to the ink cartridge 13 (hereinafter referred to as ink retracting direction). This pump is capable of feeding ink in both directions.

4A and 4B are diagrams showing a specific example of the pump 12, in which FIG. 4A shows a schematic configuration of the screw pump 12a, and FIG. 4B shows a schematic configuration of the vane pump 12d.
In the screw pump 12a, as shown in FIG. 4A, the screw rotor 12c is rotated in contact with the casing 12b so that the ink is between the screw thread of the screw rotor 12c and the inner wall of the casing 12b. It fills the gap that can be made and is sent in the axial direction to function as a pump. On the other hand, as shown in FIG. 4B, the vane pump 12d has a configuration in which plate-like blades (vanes) 12g freely enter and exit in the radial direction of the rotor 12f through grooves provided radially in the rotor 12f. Have As the rotor 12f rotates, the vane 12g extends outward in the radial direction of the rotor 12f by centrifugal force, the tip of the vane 12g contacts the inner peripheral surface of the casing 12e, and slides as the rotor 12f rotates. Due to the rotation of the rotor 12f, the size of the chamber surrounded by the vane 12g, the rotor 12f and the casing 12e expands and contracts to act as a pump. In the ink jet recording apparatus 1 of the present embodiment, either the screw pump 12a or the vane pump 12d may be used as the ink liquid feeding pump 12.

  FIG. 5 is a diagram showing a schematic configuration of the pump drive switching mechanism 17. The pump drive switching mechanism 17 is for selectively driving each pump 12 corresponding to each color ink of K, Y, C, and M.

  As shown in FIG. 5A, the pump drive switching mechanism 17 includes a drive switching gear 18 and a pump drive motor for switching connection of driving force to the pumps 12 for ink of K, Y, C, and M colors. 23 (not shown in FIG. 5; see FIG. 6), the pump drive shaft 19 is rotated, the gear support member 20 is rotatably supported around the pump drive shaft 19, and is passed through the pump drive shaft 19. Drive shaft gear 21a, an intermediate gear 21b supported by one end of the gear support member 20 and engaged with the drive shaft gear 21a, a pump side gear 21c for driving the pump 12, and the like. A series of configurations including the gear support member 20, the drive shaft gear 21a, the intermediate gear 21b, and the pump side gear 21c are provided for each pump 12 corresponding to each color ink. Each gear support member 20 is always urged in the direction in which the intermediate gear 21b is engaged with the pump-side gear 21c.

  The drive switching gear 18 is configured to rotate by the operation of a drive switching motor 22 (not shown in FIG. 5; see FIG. 6) such as a stepping motor. The drive switching gear 18 is formed with strip-shaped teeth 18a that engage with the other ends of the respective gear support members 20 provided below when rotating in a radial direction at 90 ° intervals in four directions. Furthermore, the tooth 18a in each direction is provided with a notch so as not to engage with the gear support member 20 corresponding to each tooth 18a on a one-to-one basis at a different position. In other words, by rotating the drive switching gear 18 by a predetermined amount (90 °), the pump to be driven is selected one by one by the action of each tooth 18a provided on the drive switching gear 18 and its notch portion. It is configured to be able to.

  Specifically, as shown in FIG. 5B, when the notch portion of the tooth 18a is on the lower side, the gear support member 20 corresponding to the notch portion moves the intermediate gear 21b to the pump side gear 21c. The intermediate gear 21b is engaged with the pump side gear 21c. Accordingly, the drive shaft gear 21a, the intermediate gear 21b, and the pump side gear 21c are engaged with each other. At this time, the rotation of the pump drive shaft 19 that is rotated by receiving the drive of the pump drive motor 23 is transmitted to the pump side gear 21c via the drive shaft gear 21a and the intermediate gear 21b that are passed through the pump drive shaft 19. The pump 12 is driven by the rotation of the pump side gear 21c.

  On the other hand, as shown in FIG. 5 (c) (this figure shows a state in which the drive switching gear 18 is rotated by 90 ° counterclockwise from the state shown in FIG. 5 (b)), the teeth 18a are moved downward. When engaged with the other end of the rotating gear support member 20, the gear supporting member 20 rotates around the pump drive shaft 19 against the urging force (clockwise direction in FIG. 5C). The engagement between the intermediate gear 21b and the pump-side gear 21c that are pivotally supported on one end side of the gear support member 20 is released. At this time, the rotation of the pump drive shaft 19 is not transmitted to the pump side gear 21c, and the pump 12 is not driven.

  In the pump drive switching mechanism 17, each pump 12 is driven in both forward and reverse directions by switching the rotational direction of the pump drive motor 23, that is, the ink is supplied in both directions of the ink supply direction and the ink withdrawal direction. It is possible to send.

[Electrical Configuration of Inkjet Recording Apparatus 1]
Here, the electrical configuration of the inkjet recording apparatus 1 will be described with reference to the block diagram of FIG.

As shown in FIG. 6, the inkjet recording apparatus 1 includes a control device 110 having a CPU 111, a ROM 112, a RAM 113, and an EEPROM 114.
The control device 110 conveys the recording paper 40, various sensor groups 116 including well-known media sensors and registration sensors that can detect the presence or absence of the recording paper 40, the leading edge, the trailing edge, and the edge in the width direction. It is electrically connected to a paper transport encoder 117 that detects the amount (position), the operation panel 6, a carriage feed encoder 118, and the like.

  Further, the control device 110 further includes a paper feed motor drive circuit 120a for driving the paper feed motor 122, a transport motor drive circuit 120b for driving the paper transport motor 123, and a carriage motor drive for driving the carriage motor 124. A circuit 120c, a printhead drive circuit 120d for driving the printhead 4 (ink ejection), a drive switching motor drive circuit 120e for driving the drive switch motor 22, and a pump drive motor for driving the pump drive motor 23 The drive circuit 120f and the release rod drive circuit 120g for driving the release rod drive unit 24 are electrically connected to each other.

  Then, the CPU 111 controls each of the drive circuits 120a to 120g according to various programs stored in the ROM 112 and the EEPROM 114, so that each drive target is driven and controlled. As described above, the paper feed roller 8 is driven by the rotation of the paper feed motor 122, and the transport roller 7 a is driven by the rotation of the paper transport motor 123.

The control device 110 is electrically connected to the bubble detection devices 11 a and 11 b of the ink supply tubes 11.
Further, the RAM 113 of the control device 110 stores an initial dimension corresponding value that is an initial value of the dimension corresponding value for each ink supply tube 11.

  Here, the dimension-corresponding value is a value obtained from the dimension of the ink supply tube 11 (specifically, the dimension of the portion from the first detection position to the second detection position in the ink supply tube 11). For example, the inner diameter, length, internal volume, and internal flow path resistance (pressure loss) of the ink supply tube 11 correspond to the dimension correspondence values.

  Various types of dimension correspondence values can be adopted as described above. In the present embodiment, the case where each of the following two types of values (1) and (2) is a dimension-corresponding value will be described below.

(1) Inner diameter of each ink supply tube 11 from the first detection position to the second detection position (hereinafter simply referred to as “inner diameter of each ink supply tube 11”, “inner diameter of ink supply tube 11”, or “ Also referred to as Dimensional Value 1 ”.)
(2) Channel resistance (pressure loss) when ink flows in the portion from the first detection position to the second detection position in each ink supply tube 11 (hereinafter simply referred to as “flow of each ink supply tube 11” Also referred to as “path resistance”, “flow path resistance of ink supply tube 11”, or “dimension corresponding value 2”.)
The initial dimension correspondence value is an initial value of the dimension correspondence value. As a specific example of the initial dimension correspondence value, for example, a design dimension correspondence value or a dimension correspondence value actually measured when the inkjet recording apparatus 1 is manufactured can be considered.

  In the present embodiment, the design value of “inner diameter of each ink supply tube 11” and the design value of “flow path resistance of each ink supply tube 11” are stored in the RAM 113 as initial dimension correspondence values. The case will be described below. Hereinafter, the initial dimension corresponding value regarding “inner diameter of each ink supply tube 11” is also referred to as “initial dimension corresponding value 1”, and the initial dimension corresponding value regarding “channel resistance of each ink supply tube 11” is “initial dimension corresponding value 2”. "

The RAM 113 stores a table in which “the inner diameter of each ink supply tube 11” is associated with the pump liquid feeding amount (see FIG. 9).
Here, the pump liquid feed amount is at least in each ink supply tube 11 (in the present embodiment, each of the ink supply tubes 11 to be discarded at the time of initial introduction and at a time point at which a predetermined time has elapsed from the time of initial introduction. This is the amount of waste transported by the pump 12 of a mixture of ink and bubbles existing in the ink supply tube 11 and in the recording head 4 (sub tank 14) connected to each ink supply tube 11. Such disposal suitably prevents the thickened ink from remaining in each ink supply tube 11. Note that “at the time of initial introduction” is when the user first turns on the power of the inkjet recording apparatus 1.

The RAM 113 also stores a table in which “flow path resistance of each ink supply tube 11” is associated with pump liquid feeding pressure (see FIG. 10).
Here, the pump liquid supply pressure refers to a purge operation for recovering the discharge capability of the ejection nozzles 14a of the recording head 4 to which each ink supply tube 11 is connected according to the operation of the operation panel 6 by the user. In addition, the pressure that the pump 12 should apply to the ink (specifically, the mixture of ink and bubbles) existing in the ink supply tube 11.

  The RAM 113 of the control device 110 is used to store the measured ink discharge amount. The ink discharge amount is measured by performing a counting process (S320 to S340 and S370 to S380 (FIG. 8) described later) each time ink is discharged from each nozzle.

  In the count process, the count value stored in the RAM 113 is incremented by a predetermined value (for example, 1) each time a predetermined amount of ink is ejected. The count value increased at a time is changed depending on the size of the ejected ink droplet.

  For example, when a relatively small ink droplet is ejected once, the count value is increased by 1, while when a relatively large ink droplet is ejected once, the count value is increased by 3. Executed.

  In the count process, for example, even when a purge operation (discharge capacity recovery process) for recovering the discharge capacity of the ejection nozzle 14a is performed by an operation by the user of the operation panel 6, the count value is set to a predetermined value (for example, 50) Increase processing is executed.

  The RAM 113 also stores an ink discharge amount per count value (hereinafter also simply referred to as “unit discharge amount”). The unit discharge amount is the same as the count value when the count is stopped (described later in S340 (FIG. 8)) while the bubbles move from the first detection position to the second detection position in each ink supply tube 11. It is used to convert the amount of ink ejected from each ejection nozzle 14a corresponding to the tube 11 (hereinafter also simply referred to as “ink transfer amount”).

  Here, the “ink transfer amount” is, in other words, transferred through each ink supply tube 11 while bubbles move from the first detection position to the second detection position in each ink supply tube 11. This is the amount of transfer of the mixture of ink and bubbles.

  Further, the control device 110 performs “ink replacement processing” for replacing the ink in each ink supply tube 11 and the recording head 4 (sub tank 14) connected to each ink supply tube 11, and rank data regarding each ink supply tube 11. The “tube rank detection process” (details will be described later) is executed.

  Note that the control device 110 (in particular, the RAM 113 and the CPU 111) corresponds to an initial value storage unit, a corresponding value storage unit, and an average value storage unit. The control device 110 (in particular, the CPU 111 and the RAM 113) corresponds to the transfer amount determining means and the discharge amount measuring means together with the bubble detection devices 11a and 11b. The control device 110 (in particular, the CPU 111) corresponds to a corresponding value determining unit, an average value determining unit, a deviation determining unit, and a determining unit. The control device 110 (in particular, the CPU 111) corresponds to a drive unit together with the drive switching motor drive circuit 120e, the drive switching motor 22, the pump drive motor drive circuit 120f, and the pump drive motor 23.

[Description of ink replacement process]
Hereinafter, the ink replacement process executed by the control device 110 will be described with reference to the flowchart of FIG. FIG. 7 is a flowchart showing a procedure of ink replacement processing executed in the control device 110.

  This ink replacement process is a process of replacing the ink in the ink supply tube 11 and the recording head 4 in order to suitably prevent the thickened ink from remaining in each ink supply tube 11. It is executed repeatedly when the power is turned on.

  First, it is determined at the time of initial introduction or whether a predetermined time has elapsed since the ink replacement operation, which is a subroutine of this processing, was executed last time (S210). The predetermined time referred to here is preferably set to about 20 to 30 days in consideration of the thickening of the ink in the ink supply tube 11 and the recording head 4. In the present embodiment, the predetermined time is set to 20 days. If it is determined that it is not at the time of initial introduction or that a predetermined time has not elapsed (S210: N), this processing is terminated as it is. On the other hand, when it is determined at the time of initial introduction or when a predetermined time has elapsed (S210: Y), an ink replacement operation as a subroutine is executed (S220). Then, the time when the ink replacement operation is executed is stored in the RAM 113 or the like (S230), and this process is terminated.

  Next, the ink replacement operation (S220), which is a subroutine, will be described. First, rank data (pump liquid feed amount (see FIG. 9)) corresponding to each ink supply tube 11 is called from the RAM 113 (S222), and each pump 12 is operated based on the called rank data (S224). That is, in the process of S340 to S360 described later (FIG. 8), the pump liquid feeding amount determined based on the inner diameter of each ink supply tube 11 (specifically, a mixture of ink and bubbles) is discharged. Each pump 12 is operated. Then return. Note that rank data (pump liquid feed amount) is stored in the RAM 113 in tube rank detection processing described later.

[Description of tube rank detection process]
Hereinafter, the tube rank detection process executed by the control device 110 will be described with reference to the flowchart of FIG. 8, FIG. 9, and FIG. FIG. 8 is a flowchart showing the procedure of tube rank detection processing executed in the control device 110 for each ink supply tube 11. FIG. 9 is an explanatory diagram showing a correspondence setting rank table in which the inner diameter of the ink supply tube 11 is associated with the pump liquid feeding amount. FIG. 10 is an explanatory diagram showing a correspondence setting rank table in which the flow path resistance of the ink supply tube 11 is associated with the pump liquid feeding pressure.

  In this tube rank detection process, the inner diameter of each ink supply tube 11 is detected to detect two types of rank data (pump liquid feed amount (see FIG. 9) and pump liquid feed pressure (FIG. 10) corresponding to each ink supply tube 11. This process is repeatedly executed when the power of the inkjet recording apparatus 1 is turned on. The tube rank detection process is executed for each ink supply tube 11 provided corresponding to each of the four recording heads 4 described above.

  First, based on the output signal from the bubble detection device 11a, it is determined whether or not a bubble is detected at the first detection position (S310). If it is determined that no bubbles are detected at the first detection position (S310: N), this process is terminated. On the other hand, when it is determined that bubbles are detected at the first detection position (S310: Y), the count value used for the count process is reset and the count process is started (S320).

  Subsequently, based on the output signal from the bubble detection device 11b, it is determined whether or not the bubble is detected at the second detection position (S330). If it is determined that no bubbles are detected at the second detection position (S330: N), it is determined whether the count value obtained by measuring the ink ejection amount is the MAX value (S370). If the count value is not the MAX value, the process returns to S330 (S370: N), and if the count value is the MAX value, the count process is stopped and the process returns to S310 (S370: Y, S380)). Here, the MAX value refers to the maximum value of the count value that should be counted in the counting process until the bubble reaches the second detection position from the first detection position. In other words, even if this MAX value is counted, if bubbles are not detected at the second detection position, the bubbles consume ink (in other words, ink transfer to the outside of the ink supply tube 11 accompanying ink ejection). As a result, the counting process is stopped assuming that the bubbles are not moving in the ink supply tube 11.

On the other hand, when it is determined that bubbles are detected at the second detection position (S330: Y), the counting process is stopped (S340).
In S340, the ink transfer amount is determined based on the count value at the time of the stop and the unit discharge amount stored in the RAM 113. Then, the inner diameter of the ink supply tube 11 and the flow path resistance of the ink supply tube 11 are determined from the ink transfer amount, and both are stored in the RAM 113.

  The ink transfer amount determined here is also referred to as a volume in a portion between the first detection position and the second detection position in the ink supply tube 11 (hereinafter simply referred to as “volume of the ink supply tube 11”). )).

  In the present embodiment, the length of the portion from the first detection position to the second detection position in the ink supply tube 11 (hereinafter, also simply referred to as “the length of the ink supply tube 11”), ink, and the like. The surface roughness (hereinafter also simply referred to as “tube roughness”) of the portion from the first detection position to the second detection position on the inner wall surface of the supply tube 11 is related to the difference between the ink supply tubes 11. It is assumed that the same value is set in advance.

  Therefore, in S340, the inner diameter of the ink supply tube 11 can be determined from the ink transfer amount corresponding to the volume of the ink supply tube 11. In S340, the flow path resistance of the ink supply tube 11 can also be determined from the inner diameter of the ink supply tube 11.

  Next, in S350, a deviation between the inner diameter of the ink supply tube 11 determined in S340 and the currently held value (hereinafter also simply referred to as “held value 1”) regarding the inner diameter of the ink supply tube 11 is determined in advance. Judge whether the value is out of range.

In the present embodiment, the possessed value 1 is a value stored in advance in the RAM 113, and the following three modes are assumed as specific modes.
(1) Value corresponding to initial dimension 1 (in this embodiment, “design value of“ inner diameter of ink supply tube 11 ”)
The initial dimension correspondence value 1 is used as the retained value 1 when the first tube rank detection process is executed after the initial introduction.

(2) At least one dimension-corresponding value 1 (in this embodiment, at least one “inner diameter of the ink supply tube 11” value determined and stored by executing the process of S340 at least once) and an initial value Average value with dimension-corresponding value 1 When tube rank detection processing is executed for the second and subsequent times, the number of dimension-corresponding values 1 stored in RAM 113 is one or more, but two or more predetermined values. When the number is less than three (for example, three), the average value of the dimension corresponding value 1 and the initial dimension corresponding value 1 is used as the retained value 1.

(3) Average value of dimension correspondence value 1 that is equal to or more than a predetermined number (for example, three) determined and stored by repeatedly executing the process of S340 The number of dimension correspondence values 1 stored in the RAM 113 is relatively large. In such a case, for example, the average value of the predetermined number of dimension correspondence values 1 determined and stored in the recent plural times (for example, three times) of S340 is used as the retained value 1.

  In S350, the deviation between the flow path resistance of the ink supply tube 11 determined in S340 and the current held value (hereinafter, also simply referred to as “held value 2”) regarding the flow path resistance of the ink supply tube 11 is obtained. It is also determined whether or not is a value outside the predetermined range.

In the present embodiment, the possessed value 2 is a value stored in advance in the RAM 113, and the following three modes are assumed as specific modes.
(1) Initial dimension correspondence value 2 (in this embodiment, “design value of“ flow path resistance of ink supply tube 11 ”)
The initial dimension correspondence value 2 is used as the retained value 2 when the first tube rank detection process is executed after the initial introduction.

(2) At least one dimension-corresponding value 2 (in this embodiment, at least one “flow resistance of the ink supply tube 11” value determined and stored by executing the process of S340 at least once) and The average value with the initial dimension correspondence value 2 When the tube rank detection process for the second and subsequent times is executed, the number of dimension correspondence values 2 stored in the RAM 113 is one or more, but two or more in advance. When the number is less than a predetermined number (for example, three), the average value of the dimension corresponding value 2 and the initial dimension corresponding value 2 is used as the retained value 2.

(3) Average value of dimension correspondence values 2 that is equal to or greater than a predetermined number (for example, three) determined and stored by repeatedly executing the process of S340 The number of dimension correspondence values 2 stored in the RAM 113 is relatively large. In this case, for example, the average value of the predetermined number of dimension correspondence values 2 determined and stored in the process of S340 at a plurality of recent times (for example, three times) is used as the retained value 2.

  In the process of S350, if it is determined that at least one of the following conditions (1) and (2) is satisfied, an affirmative determination is made (S350: Y), and the process proceeds to S360. If it is determined that the condition is not satisfied, a negative determination is made (S350: N), and this processing is terminated as it is.

Condition (1) The deviation between the inner diameter of the ink supply tube 11 determined in S340 and the retained value 1 is outside a predetermined range.
Condition (2) The deviation between the flow path resistance of the ink supply tube 11 determined in S340 and the retained value 2 is outside a predetermined range.

In subsequent S360, the following processing is performed.
Specifically, when it is determined in S350 that the condition (1) is satisfied, one of the following processes (A) and (B) is executed.

  (A) An average value of at least one dimension corresponding value 1 including the dimension corresponding value 1 stored in the RAM 113 in S340 of this process and the initial dimension corresponding value 1 is determined, and the average value is used as an update value of the possessed value 1 Store in the RAM 113.

  In the process (A), the total number of dimension correspondence values 1 stored in the RAM 113 including the dimension correspondence value 1 stored in the RAM 113 in S340 of this process is less than a predetermined number (for example, three). If executed.

  (B) The average value of a plurality of dimension correspondence values 1 stored in the RAM 113 in the recent plural times (for example, three times) of the processing of S340, including the dimension correspondence value 1 stored in the RAM 113 in S340 of this process. The average value is determined and stored in the RAM 113 as an update value of the holding value 1.

The process (B) is executed when the total number of dimension correspondence values 1 stored in the RAM 113 is equal to or greater than a predetermined number (for example, 3).
In S360, based on the table (see FIG. 9) stored in the RAM 113 from the held value 1 (inner diameter of the ink supply tube 11) updated in any one of the processes (A) and (B). Determine the pump fluid delivery. Specifically, the pump liquid feed amount is determined so that the following calculation formula (1) is established between the retained value 1 (inner diameter of the ink supply tube 11) and the pump liquid feed amount.

An ^ 2 × 3.14 (circumference ratio) / Qn = constant (1)
An is the inner diameter of the ink supply tube 11, and Qn is the pump liquid feed amount (n is an integer of 1 or more).

In S360, the pump liquid feed determined as described above is stored in the RAM 113 as rank data used in the process of S224.
In S360, if it is determined in S350 that the condition (2) is satisfied, one of the following processes (C) and (D) is executed.

  (C) An average value of at least one dimension corresponding value 2 including the dimension corresponding value 2 stored in the RAM 113 in S340 of this process and the initial dimension corresponding value 2 is determined, and the average value is used as an update value of the possessed value 2 Store in the RAM 113.

  In the process (C), the total number of dimension correspondence values 2 stored in the RAM 113 including the dimension correspondence value 2 stored in the RAM 113 in S340 of this process is less than a predetermined number (for example, three). If executed.

  (D) The average value of the plurality of dimension correspondence values 2 stored in the RAM 113 in the recent plural times (for example, three times) of S340 processing, including the dimension correspondence value 2 stored in the RAM 113 in S340 of this process. The average value is determined and stored in the RAM 113 as an update value of the possessed value 2.

The process (D) is executed when the total number of dimension correspondence values 2 stored in the RAM 113 is equal to or greater than a predetermined number (for example, 3).
In S360, a table stored in the RAM 113 (see FIG. 10) from the holding value 2 (flow path resistance of the ink supply tube 11) updated in any one of the processes (C) and (D). Based on the above, the pump liquid feed pressure is determined. Specifically, the pump liquid feeding pressure is determined so that the following calculation formula (2) is established between the retained value 2 (flow path resistance of the ink supply tube 11) and the pump liquid feeding pressure.

Hn / Pn = constant (2)
Note that Hn is a flow path resistance of the ink supply tube 11, and Pn is a pump liquid feeding pressure (n is an integer of 1 or more).

  In S360, the pump fluid feed pressure determined as described above is stored in the RAM 113 as rank data. This rank data is used as data indicating the pressure to be applied to the pump 12 during the discharge capacity recovery process to be executed in the future. That is, the pump 12 is controlled by the control device 110 so that the pump liquid supply pressure is obtained during the discharge capacity recovery process.

[effect]
(1) As described above, according to the ink jet recording apparatus 1 of the above-described embodiment, each ink supply tube 11 is based on the ink amount (ink transfer amount) ejected while the bubble moves between the two detection positions. Dimension corresponding values 1 and 2 are determined. Then, based on the dimension correspondence values 1 and 2, the pump liquid feed amount at the time of the ink replacement process and the pump liquid feed pressure at the time of the discharge ability recovery process are determined.

  In the above-described embodiment, the amount of wasted ink ejected from the ejection nozzle 14a during the ink replacement process and the ejection performance recovery process, as much as the drive control of the pump 12 based on the dimension correspondence values 1 and 2 is realized. Can be reduced.

  (2) Further, according to the ink jet recording apparatus 1 of the above embodiment, the first detection position is set in the vicinity of the sub tank 14 side of the pump 12 in the ink supply tube 11, and the second detection position is set. The ink supply tube 11 is set near the sub tank 14.

  As a result, the distance between the first detection position and the second detection position is close to the actual length of the ink supply tube 11. Therefore, in the present embodiment, drive control of the pump 12 corresponding to the dimension corresponding values 1 and 2 of the entire ink supply tube 11 is easily realized.

  (3) In the above embodiment, when there are more than a predetermined number of dimension correspondence values 1 and 2 stored in the RAM 113, the average value of each of the plurality of dimension correspondence values 1 and 2 (after the update) Based on the held values 1, 2), drive control of the pump 12 is executed.

  Therefore, compared with the case where the drive control of the pump 12 is executed based on only one detection value relating to the dimension correspondence value 1 or only one detection value relating to the dimension correspondence value 2, the actual in each ink supply tube 11 is determined. There is a high possibility that the drive control of the pump 12 corresponding to the dimension corresponding values 1 and 2 can be accurately realized.

  (4) In the above embodiment, when the number of dimension correspondence values 1 and 2 stored in the RAM 113 is not sufficient, the drive control of the pump 12 is executed based on the initial dimension correspondence values 1 and 2. .

  Accordingly, even when the number of dimension correspondence values 1 and 2 stored in the RAM 113 is not sufficient, the drive control of the pump 12 corresponding to the actual dimension correspondence values 1 and 2 of each ink supply tube 11 relatively accurately. The possibility of realization increases.

  (5) Further, in the above embodiment, when the count value counted in the count process reaches the MAX value, the ink transfer amount is not determined based on the count value that has reached the MAX value. That is, the ink transfer amount based on the count value that has reached the MAX value is excluded from the ink transfer amount determined in S340.

  Therefore, in the processing in the present embodiment, the bubbles in the ink supply tube 11 detected at the first detection position move in the ink supply tube 11 as the ink is transferred out of the ink supply tube 11, for example. This is suitable when the bubbles are not generated. That is, it is possible to prevent the ink transfer amount from being erroneously determined based on the movement of the “bubbles in the ink supply tube 11 detected at the first detection position”.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, It is possible to implement in the following various aspects. In the following description, in the description of the modified example of the above embodiment, only points different from the above embodiment will be described, and description of similar points will be omitted.

[Modification 1] Modifications of Dimension Corresponding Values 1 and 2 The dimension corresponding value 1 may be the volume of the ink supply tube 11. Each dimension-corresponding value 1 may be the length of the ink supply tube 11. However, the length of the ink supply tube 11 can be set to the dimension corresponding value 1 in a case where it can be assumed that the inner diameter of the ink supply tube 11 is constant regardless of the difference of the ink supply tubes.

Even in these cases, the initial dimension correspondence value 1 is set as the initial value of the dimension correspondence value 1.
In the above embodiment, the flow path resistance of the ink supply tube 11 is set as the dimension-corresponding value 2, but the inner diameter of the ink supply tube 11 may be set as the dimension-corresponding value 2. In this case as well, the initial dimension correspondence value 2 may be set as the initial value of the dimension correspondence value 2.

  Even in this case, when it is assumed that the length of the ink supply tube 11 and the tube roughness are the same predetermined value regardless of the difference in the ink supply tube 11, the pump liquid is determined from the inner diameter of the ink supply tube 11. The pressure can be determined.

In this case, the table of FIG. 10 stored in the RAM 113 is replaced with a table in which the inner diameter of each ink supply tube 11 is associated with the pump liquid supply pressure.
[Modification 2] Modification concerning the method for determining the pump liquid feed amount The pump liquid feed amount may be determined directly based on the ink transfer amount determined in S340.

  Specifically, in this case, first, the ink determined in advance based on the initial dimensions of each ink supply tube 11 (designed dimensions or dimensions obtained from actual measurement at the time of manufacturing the inkjet recording apparatus 1). An initial value (initial transfer amount) of the transfer amount is stored in the RAM 113.

Further, the table of FIG. 9 stored in the RAM 113 is replaced with a table in which the ink transfer amount by each ink supply tube 11 and the pump liquid supply amount are associated with each other.
In step S <b> 340, the ink transfer amount is stored in the RAM 113 instead of the inner diameter of the ink supply tube 11.

  In subsequent S350, whether the deviation between the ink transfer amount determined and recorded in S340 and the current held value related to the ink transfer amount (hereinafter also simply referred to as “held value 3”) is a value outside the predetermined range. Judge whether or not.

In this embodiment, the retained value 3 is a value stored in advance in the RAM 113, and the following three modes are assumed as specific modes.
(A) Initial transfer amount The initial transfer amount is used as the retained value 3 when the first tube rank detection process is executed after the initial introduction.

(B) Average value of at least one ink transfer amount (in this embodiment, at least one ink transfer amount determined and stored by executing the process of S340 at least once) and the initial transfer amount 2 When tube rank detection processing after the first time is executed and the number of ink transfer amounts stored in the RAM 113 is one or more, but less than two or more predetermined numbers (for example, three) The average value of the ink transfer amount and the initial transfer amount is used as the retained value 3.

(C) An average value of the ink transfer amounts of a predetermined number (for example, three) or more determined and stored by repeatedly executing the process of S340.
When the number of ink transfer amounts stored in the RAM 113 is relatively large, for example, a predetermined number of ink transfers determined and stored in the recent plural times (for example, three times) of S340. The average value of the quantity is used as the retained value 3.

  If it is determined in S350 that the deviation between the ink transfer amount determined in S340 and the retained value 3 is outside the predetermined range, the following (A) and (B) are performed in S360. One of the processes is executed.

  (A) An average value of at least one ink transfer amount including the ink transfer amount stored in the RAM 113 in S340 of this process and the initial transfer amount is determined, and the average value is stored in the RAM 113 as an update value of the held value 3. .

  The process (A) is performed when the total number of ink transfer amounts stored in the RAM 113 including the ink transfer amount stored in the RAM 113 in S340 of this process is less than a predetermined number (for example, 3). Executed.

  (B) An average value of a plurality of ink transfer amounts stored in the RAM 113 in the recent multiple times (for example, three times) of S340 processing including the ink transfer amount stored in the RAM 113 in S340 of the present process is determined. The average value is stored in the RAM 113 as an update value of the retained value 3.

The process (B) is executed when the total number of ink transfer amounts stored in the RAM 113 is equal to or greater than a predetermined number (for example, 3).
In S360, the ink transfer amount by each ink supply tube 11 stored in the RAM 113 from the held value 3 (ink transfer amount) updated in any one of the processes (A) and (B) described above. Then, the pump liquid feed amount is determined based on the table in which the pump liquid feed amount is associated. Specifically, the pump liquid feed amount is determined so that the following calculation formula (3) is established between the retained value 3 (ink transfer amount) and the pump liquid feed amount.

In / Qn = constant (3)
Here, In is an ink transfer amount, and Qn is a pump liquid transfer amount (n is an integer of 1 or more).
In S360, the pump liquid feed determined as described above is stored in the RAM 113 as rank data used in the process of S224.

  In the second modification, the “ink transfer amount determined in S340” may be replaced with the count value itself obtained in S340 when the count process is stopped, as corresponding to the ink transfer amount. Further, the initial transfer amount may be replaced with an initial value of “a count value when the count process is stopped” corresponding to the initial transfer amount.

  In the case of the second modification, the control device 110 (in particular, the RAM 113 and the CPU 111) corresponds to an initial value storage unit, an initial amount storage unit, a corresponding value storage unit, a transfer amount storage unit, and an average value storage unit. The control device 110 (in particular, the CPU 111 and the RAM 113) corresponds to the transfer amount determining means and the discharge amount measuring means together with the bubble detection devices 11a and 11b. The control device 110 (in particular, the CPU 111) corresponds to a corresponding value determining unit, an average value determining unit, a deviation determining unit, and a determining unit. The control device 110 (in particular, the CPU 111) corresponds to a drive unit together with the drive switching motor drive circuit 120e, the drive switching motor 22, the pump drive motor drive circuit 120f, and the pump drive motor 23.

[Modification 3] Modification Regarding Rank Data Determination without Average Value Determination In the above embodiment, when there are more than a predetermined number of dimension correspondence values 1 and 2 stored in the RAM 113, there are a plurality of dimensions. Based on the average values of the corresponding values 1 and 2 (retained values 1 and 2 after the update), the pump liquid feed amount and the pump liquid feed pressure were determined.

  However, the process of S350 is omitted, and in S360, the pump liquid feed amount and the pump liquid feed pressure are directly determined from each of the one dimension corresponding value 1 and one dimension corresponding value 2 determined in S340. May be.

  In the second modification, when there are more than a predetermined number of ink transfer amounts stored in the RAM 113, the pump liquid is based on the average value (updated retained value 3) of a plurality of ink transfer amounts. We decided the amount to send.

  However, in the second modified example, the process of S350 may be omitted, and in S360, the pump liquid feed amount may be determined directly from the single ink transfer amount determined in S340.

1 is an external perspective view of an inkjet recording apparatus 1 suitable for applying the present invention. 2 is a cross-sectional view of the inkjet recording apparatus 1. FIG. 2A and 2B are explanatory views showing a schematic configuration of an ink supply mechanism of the ink jet recording apparatus 1, wherein FIG. 2A is a diagram schematically showing a side cross section of the ink supply mechanism, and FIG. FIG. It is a figure which shows the specific example of the pump 12, (a) is a figure which shows schematic structure of the screw pump 12a, (b) is a figure which shows schematic structure of the vane pump 12d. FIG. 3 is a diagram showing a schematic configuration of a pump drive switching mechanism 17. 2 is a block diagram showing an electrical configuration of the inkjet recording apparatus 1. FIG. It is a flowchart which shows the procedure of an ink replacement process. It is a flowchart which shows the procedure of a tube rank detection process. It is explanatory drawing which shows a corresponding | compatible setting rank table | surface. It is explanatory drawing which shows a corresponding | compatible setting rank table | surface.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Inkjet recording device, 2 ... Scanner, 3 ... Paper feed cassette, 4 ... Recording head, 6 ... Operation panel, 7 ... Recording part, 11 ... Ink supply tube, 11a, 11b ... Bubble detection device, 12 ... Pump, 12a ... Screw pump, 12b ... Casing, 12c ... Screw rotor, 12d ... Vane pump, 12e ... Casing, 12f ... Rotor, 12g ... Blade (vane) 13 ... Ink cartridge, 14 ... Sub tank, 14a ... Injection nozzle, 15 ... Valve Unit: 15a ... Spring, 15b ... Valve, 15c ... Packing, 15d ... Gas permeable membrane, 15e ... Vent, 15f ... Large diameter part, 16 ... Release rod, 17 ... Pump drive switching mechanism, 18 ... Drive switching gear, 18a ... Teeth, 19 ... Pump drive shaft, 20 ... Gear support member, 21a ... Drive shaft gear, 21b ... Intermediate gear, 21c Pump gear, 22 ... drive switching motor, 23 ... pump drive motor, 110 ... control device, 120e ... drive switching motor drive circuit, 120f ... pump drive motor drive circuit

Claims (18)

A recording head for recording an image on a recording medium by selectively ejecting ink in the subtank from the ejection nozzle, and a subtank for storing ink and an ejection nozzle;
A main tank for storing ink supplied into the sub tank;
A tube connecting the sub tank and the main tank;
Transfer means for transferring ink present in the tube;
A transfer amount determination means for determining a transfer amount of a mixture of ink and bubbles transferred through the tube while the bubbles move from a first detection position to a second detection position in the tube;
Drive means for controlling drive of the transfer means based on the transfer amount determined at least once by the transfer amount determination means;
An ink jet recording apparatus comprising: The inkjet recording apparatus according to claim 1, wherein
A discharge amount measuring means for measuring the amount of ink discharged from the ejection nozzle at least once while bubbles move from a first detection position to a second detection position in the tube;
The transfer amount determination means is configured to pass through the tube while bubbles move from the first detection position to the second detection position in the tube based on the ink amount measured at least once by the discharge amount measurement means. An ink jet recording apparatus, wherein a transfer amount of a mixture of ink and bubbles to be transferred is determined at least once. The inkjet recording apparatus according to claim 1 or 2,
A transfer amount of a mixture of ink and bubbles transferred through the tube while the bubbles move from the first detection position to the second detection position in the tube, based on an initial dimension of the tube in advance. An initial amount storage means for storing the set initial transfer amount;
Before the transfer amount is actually determined by the transfer amount determination means, the transfer amount determination means determines the initial transfer amount stored in the initial amount storage means by the transfer amount determination means. Determined as the transfer amount,
The ink jet recording apparatus, wherein the driving unit performs driving control of the transfer unit based on the initial transfer amount. The inkjet recording apparatus according to claim 1 or 2,
Corresponding value determining means for determining at least one dimension corresponding value of the tube based on the transferring amount determined at least once by the transferring amount determining means,
The ink jet recording apparatus, wherein the driving unit controls the driving of the transfer unit based on at least one dimension corresponding value determined by the corresponding value determining unit. The inkjet recording apparatus according to claim 4, wherein
An initial value storage means for storing a preset initial dimension corresponding value based on the initial dimension of the tube;
Before the dimension correspondence value is actually determined at least once by the correspondence value determination means, the correspondence value determination means uses the initial dimension correspondence value stored in the initial value storage means as the correspondence value determination means. Determined as the dimension-corresponding value determined by
The ink jet recording apparatus, wherein the driving unit controls driving of the transfer unit based on the initial dimension correspondence value. The inkjet recording apparatus according to claim 1 or 2,
The transfer amount determination means repeatedly determines the transfer amount,
The ink jet recording apparatus
Transfer amount storage means for storing a plurality of transfer amounts repeatedly determined by the transfer amount determination means;
Average value determination means for determining an average value of at least two transfer amounts stored by the transfer amount storage means;
With
The ink jet recording apparatus, wherein the driving unit performs driving control of the transfer unit based on the average value determined by the average value determining unit. The inkjet recording apparatus according to claim 6, wherein
A transfer amount of a mixture of ink and bubbles transferred through the tube while the bubbles move from the first detection position to the second detection position in the tube is set in advance based on the initial dimensions of the tube. Initial amount storage means for storing the initial transfer amount,
The average value determining means includes
When the number of transfer amounts stored by the transfer amount storage means is one or more but less than two or more predetermined numbers, at least one transfer amount stored by the transfer amount storage means and Determining an average value of the initial transfer amount stored by the initial amount storage means;
The ink jet recording apparatus, wherein the driving unit controls driving of the transfer unit based on the average value. In the ink jet recording apparatus according to claim 6 or 7,
Average value storage means for storing the average value determined by the average value determination means;
When the latest transfer amount is determined by the transfer amount determination means, and when the transfer amount storage means stores the latest transfer amount, the latest transfer amount and the average value storage means store the Deviation judging means for judging whether or not the deviation between the average value is a value outside a predetermined range;
With
When the deviation determining means determines that the deviation is outside the predetermined range,
The average value determining means determines an average value of at least two transfer amounts including the latest transfer amount stored in the transfer amount storage means, and the average value storage means determines the determined average value. Is stored as an update value of the average value that the average value storage means has stored so far,
When the deviation determining means determines that the deviation is not outside the predetermined range,
The average value determining means determines the average value stored in the average value storage means so far as the average value used when the drive means controls the transfer means. apparatus. The inkjet recording apparatus according to claim 1 or 2,
The transfer amount determination means repeatedly determines the transfer amount,
The ink jet recording apparatus
Corresponding value determining means for determining a dimension corresponding value of the tube based on each of the plurality of the transport amounts repeatedly determined by the transport amount determining means;
Correspondence value storage means for storing a plurality of dimension correspondence values determined by the correspondence value determination means;
Average value determining means for determining an average value of at least two dimension corresponding values stored by the corresponding value storage means;
With
The ink jet recording apparatus, wherein the driving unit performs driving control of the transfer unit based on the average value determined by the average value determining unit. The inkjet recording apparatus according to claim 9, wherein
An initial value storage means for storing a preset initial dimension corresponding value based on the initial dimension of the tube;
The average value determining means includes
When the number of the dimension correspondence values stored in the correspondence value storage means is one or more but less than two or more predetermined numbers, at least one of the dimension correspondences stored in the correspondence value storage means Determining an average value of the value and the initial dimension corresponding value stored in the initial value storage means;
The ink jet recording apparatus, wherein the driving unit controls driving of the transfer unit based on the average value. In the ink jet recording apparatus according to claim 9 or 10,
Average value storage means for storing the average value determined by the average value determination means;
When the latest dimension correspondence value is determined by the correspondence value determination means, and the correspondence value storage means stores the latest dimension correspondence value, the latest dimension correspondence value and the average value storage means Deviation judging means for judging whether or not the deviation between the average value to be stored is a value outside a predetermined range;
With
When the deviation determining means determines that the deviation is outside the predetermined range,
The average value determining means determines an average value of at least two dimension corresponding values including the latest dimension corresponding value stored in the corresponding value storing means, and the average value storing means determines the determined value. While storing the average value as an update value of the average value that the average value storage means has stored so far,
When the deviation determining means determines that the deviation is not outside the predetermined range,
The average value determining means determines the average value stored in the average value storage means so far as the average value used when the drive means controls the transfer means. apparatus. In the ink jet recording apparatus according to any one of claims 1 to 3,
The driving means determines at least a waste transfer amount of a mixture of ink and bubbles existing in the tube based on the transfer amount determined at least once by the transfer amount determination means, and An ink jet recording apparatus, wherein drive control of the transfer means is performed so that the mixture is discarded from the tube. The inkjet recording apparatus according to any one of claims 6 to 11,
The driving means determines at least a waste transfer amount of a mixture of ink and bubbles present in the tube based on the average value determined by the average value determination means, and the waste transfer amount of the mixture is determined as the waste transfer amount. An ink jet recording apparatus that controls driving of the transfer means so as to be discarded from within the tube. In the ink jet recording apparatus according to claim 4 or 5,
The driving means determines at least a waste transfer amount of a mixture of ink and bubbles existing in the tube based on the dimension correspondence value determined by the corresponding value determination means, and the waste transfer amount of the mixture is determined. An ink jet recording apparatus that controls driving of the transfer means so as to be discarded from the inside of the tube. In the ink jet recording apparatus according to claim 4 or 5,
The dimension-corresponding value is that the ink flows in the inner diameter of the portion from the first detection position to the second detection position in the tube and in the portion from the first detection position to the second detection position in the tube. One of the flow path resistance
The driving means determines the pressure to be applied to the ink existing in the tube for recovering the discharge capability of the ejection nozzle based on the dimension corresponding value determined by the corresponding value determining means, and corresponds to the pressure. An ink jet recording apparatus that performs drive control of the transfer means. The inkjet recording apparatus according to any one of claims 9 to 11,
The dimension-corresponding value is that the ink flows in the inner diameter of the portion from the first detection position to the second detection position in the tube and in the portion from the first detection position to the second detection position in the tube. One of the flow path resistance
The driving means determines the pressure to be applied to the ink existing in the tube for recovering the discharge capability of the ejection nozzle based on the average value determined by the average value determining means, and corresponds to the pressure. An ink jet recording apparatus that controls driving of the transfer means. The inkjet recording apparatus according to any one of claims 1 to 16,
Before the bubble moves from the first detection position to the second detection position in the tube, has the transfer amount of the mixture of ink and bubbles transferred through the tube reached a predetermined amount or more? A determination means for determining whether or not,
Before the bubble moves from the first detection position to the second detection position in the tube by the determination means, the transfer amount of the mixture transferred through the tube is equal to or more than the predetermined amount. When it is determined that
The ink-jet recording apparatus, wherein the transfer amount determining means excludes a transfer amount that is equal to or greater than the predetermined amount from the transfer amount determined by the transfer amount determining means. In the ink jet recording apparatus according to any one of claims 1 to 17,
The first detection position is set near the end of the tube on the main tank side, and the second detection position is set near the end of the tube on the sub tank side. An ink jet recording apparatus.