Liquid ejection apparatus in which notification on remaining amount of liquid in liquid chamber is suitably performed based on calculated first and second volumes

A liquid ejection apparatus includes: a cartridge including a first storage chamber storing liquid; a tank including a second storage chamber storing liquid; at least one nozzle; a detecting portion detecting whether a level of the liquid in the second storage chamber becomes equal to a prescribed position; a notifying portion; and a controller configured to perform: when the level of the liquid in the second storage chamber becomes equal to the prescribed position, calculating first and second volumes; and when the second volume is greater than the first volume, notify that the level of the liquid in the second storage chamber becomes equal to the prescribed position. The first volume is an amount of the liquid in the first storage chamber above the level of the second storage chamber at a time when the level of the liquid in the second storage chamber becomes equal to the prescribed position.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority from Japanese Patent Application No. 2018-067949 filed Mar. 30, 2018. The entire content of the priority application is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a liquid ejection apparatus in which liquid flows from a cartridge to a tank due to hydraulic head difference.

BACKGROUND

For example, Japanese Patent Application Publication No. 2008-238792 discloses a system in which liquid is supplied from a cartridge to a tank due to hydraulic head pressure, and then supplied from the tank to a head (consuming portion) configured to consume liquid. In the system disclosed in Japanese Patent Application Publication No. 2008-238792, a sensor configured to detect displacement of a sensor arm provided in the cartridge is used to determine a remaining amount of the liquid in the cartridge.

In the meantime, in another system in which liquid is supplied to a tank due to hydraulic head pressure, in order to detect a remaining amount of liquid in the cartridge, a remaining amount of the liquid in the corresponding tank is detected using a sensor rather than directly detecting the remaining amount of the liquid in the cartridge by providing a sensor arm in the cartridge.

SUMMARY

In the latter system described above, when a sensor detects that the remaining amount of the liquid in the tank decreases, the system notifies a user based on the detection that the remaining amount of the liquid in the cartridge is lowered to a prescribed amount, for example, no ink that can be supplied to the tank is remaining in the cartridge. However, in such system, the level of the liquid stored in the tank may temporarily differ from the level of the liquid stored in the cartridge. Thereafter, the level of the liquid in the tank becomes the same as that of the liquid in the cartridge. That is, a certain period of time is required until the level of the liquid stored in the cartridge and the level of the liquid stored in the tank becomes the same as each other.

In such a case, before the certain period of time has elapsed, i.e., in a state where the level of the liquid in the tank differs from the level of the liquid in the cartridge, the sensor may detect that the remaining amount of the liquid in the tank has lowered. In other words, the sensor detects that the remaining amount of the liquid in the tank has decreased even when a sufficient amount of the liquid is remaining in the cartridge, or the liquid remaining in the cartridge is to be supplied to the tank due to hydraulic head difference. Accordingly, the system notifies the user, based on the detection result obtained by the sensor, that no ink that can be supplied to the tank is remaining in the cartridge. As a result, the system erroneously notifies the user that the remaining amount of the ink has lowered based on the inappropriate detection result.

In view of the foregoing, it is an object of the disclosure to provide a liquid ejection apparatus capable of decreasing a probability of erroneous notification that the remaining amount of ink has decreased.

In order to attain the above and other objects, according to one aspect, the disclosure provides a liquid ejection apparatus including: a cartridge; a tank to which the cartridge is connectable; at least one nozzle; a detecting portion; a memory; a notifying portion; and a controller. The cartridge includes: a first storage chamber configured to store liquid therein; and a first air communicating portion allowing the first storage chamber to communicate with an atmosphere. The tank includes: a second storage chamber configured to store the liquid therein; an inlet port through which the liquid stored in the first storage chamber of the cartridge connected to the tank is introduced into the second storage chamber; an outlet port through which the liquid stored in the second storage chamber flows out; and a second air communicating portion allowing the second storage chamber to communicate with the atmosphere. The at least one nozzle is configured to eject the liquid flowing out from the second storage chamber through the outlet port. The detecting portion is configured to detect whether a level of the liquid stored in the second storage chamber becomes equal to or lower than a prescribed position. The memory stores therein a first liquid amount and a second liquid amount. The first liquid amount is an amount of the liquid stored in the first storage chamber. The second liquid amount is an amount of the liquid stored in the second storage chamber. The controller is configured to perform: in response to receiving a command to consume the liquid, (a) controlling the at least one nozzle to eject the liquid at a speed; (b) determining, while performing the (a) controlling, whether the detecting portion detects that the level of the liquid stored in the second storage chamber becomes equal to or lower than the prescribed position; in response to the (b) determining determining that the detecting portion detects that the level of the liquid stored in the second storage chamber becomes equal to or lower than the prescribed position, (c) calculating a first volume and a second volume, the first volume being an amount of the liquid stored in the first storage chamber above the level of the second storage chamber at a time when the detecting portion detects that the level of the liquid stored in the second storage chamber becomes equal to or lower than the prescribed position, the first volume being calculated based on the first liquid amount, the second liquid amount, and a third volume, the third volume being an amount of the liquid ejected by the at least one nozzle since start of the (a) controlling until the detecting portion detects that the level of the liquid stored in the second storage chamber becomes equal to or lower than the prescribed position, the second volume being an amount of the liquid ejected by the at least one nozzle since the detecting portion detects that the level of the liquid stored in the second storage chamber becomes equal to or lower than the prescribed position until completion of the (a) controlling; (d) determining whether the second volume is greater than the first volume; and in response to the (d) determining determining that the second volume is greater than the first volume, (e) controlling the notifying portion to notify that the level of the liquid stored in the second storage chamber becomes equal to or lower than the prescribed position.

According to another aspect, the disclosure provides a liquid ejection apparatus including: a cartridge; a tank to which the cartridge is connectable; at least one nozzle; a detecting portion; a memory; a notifying portion; and a controller. The cartridge includes: a first storage chamber configured to store liquid therein; and a first air communicating portion allowing the first storage chamber to communicate with an atmosphere. The tank includes: a second storage chamber configured to store the liquid therein; an inlet port through which the liquid stored in the first storage chamber of the cartridge connected to the tank is introduced into the second storage chamber; an outlet port through which the liquid stored in the second storage chamber flows out; and a second air communicating portion allowing the second storage chamber to communicate with the atmosphere. The at least one nozzle is configured to eject the liquid flowing out from the second storage chamber through the outlet port. The detecting portion is configured to detect whether a level of the liquid stored in the first storage chamber becomes equal to or lower than a prescribed position. The memory stores therein a first liquid amount and a second liquid amount. The first liquid amount is an amount of the liquid stored in the first storage chamber. The second liquid amount is an amount of the liquid stored in the second storage chamber. The controller is configured to perform: in response to receiving a command to consume the liquid, (a) controlling the at least one nozzle to eject the liquid at a speed; (b) determining, while performing the (a) controlling, whether the detecting portion detects that the level of the liquid stored in the first storage chamber becomes equal to or lower than the prescribed position; in response to the (b) determining determining that the detecting portion detects that the level of the liquid stored in the first storage chamber becomes equal to or lower than the prescribed position, (c) calculating a first volume and a second volume, the first volume being an amount of the liquid stored in the second storage chamber above the level of the first storage chamber at a time when the detecting portion detects that the level of the liquid stored in the first storage chamber becomes equal to or lower than the prescribed position, the first volume being calculated based on the first liquid amount, the second liquid amount, and a third volume, the third volume being an amount of the liquid ejected by the at least one nozzle since start of the (a) controlling until the detecting portion detects that the level of the liquid stored in the first storage chamber becomes equal to or lower than the prescribed position, the second volume being an amount of the liquid ejected by the at least one nozzle since the detecting portion detects that the level of the liquid stored in the first storage chamber becomes equal to or lower than the prescribed position until completion of the (a) controlling; (d) determining whether the second volume is greater than the first volume; and in response to the (d) determining determining that the second volume is greater than the first volume, (e) controlling the notifying portion to notify that the level of the liquid stored in the first storage chamber becomes equal to or lower than the prescribed position.

DETAILED DESCRIPTION

First Embodiment

Hereinafter, a multifunction peripheral10as an example of a liquid ejection apparatus according to a first embodiment of the present disclosure will be described with reference toFIGS. 1 through 10B. It would be apparent that the embodiment(s) described below is merely an example of the disclosure and may be modified in many ways without departing from the scope of the disclosure.

In the following description, up, down, front, rear, left, and right directions related to the multifunction peripheral10will be referred to assuming that the multifunction peripheral10is disposed on a horizontal plane so as to be operable, as illustrated inFIG. 1A. Note that this posture of the multifunction peripheral10illustrated inFIG. 1Awill also be referred to as an “operable posture”. Specifically, an up-down direction7of the multifunction peripheral10is defined based on the operable posture of the multifunction peripheral10. A front-rear direction8is defined assuming that a surface of the multifunction peripheral10formed with an opening13is a front surface of the multifunction peripheral10in the operable posture. A left-right direction9is defined based on an assumption that the multifunction peripheral10in the operable posture is viewed from its front surface.

In the present embodiment, in the operable posture of the multifunction peripheral10, the up-down direction7is parallel to a vertical direction, and the front-rear direction8and the left-right direction9are parallel to a horizontal direction. Further, the front-rear direction8and the left-right direction9are orthogonal to each other.

<Overall Configuration of Multifunction Peripheral10>

As illustrated inFIGS. 1A and 1B, the multifunction peripheral10has a lower portion in which a printer portion11is provided. The printer portion11is configured to record an image on a sheet of paper12(seeFIG. 2) based on an inkjet recording method. The multifunction peripheral10may have various functions such as a facsimile function, a scanning function, and a copying function. The printer portion11includes a casing14having a substantially rectangular parallelepiped shape.

The casing14has a front surface14A on which a display20(an example of a notifying portion) and an operating portion28are provided. The display20is a liquid crystal display or an organic electroluminescence (EL) display, for example. The display20has a display surface configured to display various kinds of information thereon. The operating portion28is configured to output an operation signal in accordance with a user's operation to a controller130that controls various operations on the multifunction peripheral10. The operating portion28may include push buttons, for example. Alternatively, if the display20has a touch sensor function, this display20having the touch sensor function may serve as the operating portion28.

As illustrated inFIG. 2, within the casing14, a feed tray15, a discharge tray16, a feed roller23, a conveying roller pair25, a discharge roller pair27, a recording portion24, and a platen26are disposed.

As illustrated inFIGS. 1A and 1B, the front surface14A is formed with the opening13at a generally center portion thereof in the left-right direction9. The feed tray15is inserted into and extracted from the casing14through the opening13in the front-rear direction8. The feed tray15is configured to support the sheets12in a stacked state.

The discharge tray16is disposed above the feed tray15. The discharge tray16is configured to support the sheets12discharged by the discharge roller pair27from the portion between the recording portion24and the platen26. The feed roller23is configured to be driven by a motor (not illustrated) so as to feed each of the sheets12supported in the feed tray15onto a conveying path17.

As illustrated inFIG. 2, the conveying path17is a space defined by a guide member18, a guide member19, the recording portion24, the platen26, and the like. The guide member18and the guide member19are disposed inside the printer portion11and face each other with a predetermined gap therebetween. The recording portion24and the platen26are also disposed inside the printer portion11and face each other with a predetermined gap therebetween.

The conveying path17extends rearward from a rear end portion of the feed tray15, and then, makes a U-turn frontward while extending upward, passes through a portion facing the recording portion24, and reaches the discharge tray16. A conveying direction in which each of the sheets12is conveyed in the conveying path17is indicated by a dashed-dotted arrow inFIG. 2.

The conveying roller pair25is disposed in the conveying path17. The conveying roller pair25includes a conveying roller25A and a pinch roller25B arranged to oppose each other. The conveying roller25A is configured to be driven by a motor (not illustrated). The pinch roller25B is configured to be rotated following rotation of the conveying roller25A. As the conveying roller25A and the pinch roller25B make forward rotation in response to forward rotation of the motor (not illustrated), each of the sheets12is nipped between the conveying roller25A and the pinch roller25B and is conveyed in the conveying direction.

The discharge roller pair27is disposed downstream of the conveying roller pair25in the conveying direction in the conveying path17. The discharge roller pair27includes a discharge roller27A and a spur roller27B arranged to oppose each other. The discharge roller27A is configured to be driven by a motor (not illustrated). The spur roller27B is configured to be rotated following rotation of the discharge roller27A. As the discharge roller27A and the spur roller27B make forward rotation in response to forward rotation of the motor (not illustrated), each of the sheets12is nipped between the discharge roller27A and the spur roller27B and is conveyed in the conveying direction.

As illustrated inFIG. 2, the recording portion24and the platen26are disposed at a position between the conveying roller pair25and the discharge roller pair27in the conveying direction. More specifically, the recording portion24and the platen26are positioned downstream of the conveying roller pair25, and positioned upstream of the discharge roller pair27in the conveying direction. The recording portion24and the platen26are arranged to oppose each other in the up-down direction7.

The recording portion24includes a carriage22and a recording head21mounted on the carriage22. The carriage22is configured to reciprocate in the left-right direction9by a driving force transmitted from a motor (not illustrated). A plurality of nozzles29are provided at a lower surface of the recording head21. That is, the recording portion24includes at least one nozzle29. The recording portion24is configured to eject ink droplets through the nozzles29by driving vibrating elements such as piezoelectric elements.

Ink tubes (not illustrated) and a flexible flat cable (not illustrated) are connected to the carriage22. The ink tubes connect a cartridge receiving portion110(described later, seeFIG. 3) and the recording head21. More specifically, each of the ink tubes is configured to supply ink stored in corresponding ink cartridge30attached to the cartridge receiving portion110to the recording head21.

In the present embodiment, four ink cartridges30are attachable to the cartridge receiving portion110. Accordingly, four ink tubes are provided in one-to-one correspondence with the four ink cartridges30so that ink of four colors (black, magenta, cyan, and yellow) stored in the respective four ink cartridges30can flow through the corresponding ink tubes. These ink tubes are bundled and connected to the carriage22. The flexible flat cable electrically connects the recording head21to the controller130(seeFIG. 8).

While the controller130controls the conveying roller pair25to temporarily stop conveyance of the sheet12in a state where a portion of the sheet12faces the recording head21, the controller130also controls the carriage22to move in the left-right direction9and the recording head21to eject the ink droplets through the nozzles29. Accordingly, a part of an image is recorded onto the portion of the sheet12that faces the recording head21(hereinafter referred to as “one pass”). Subsequently, the controller130controls the conveying roller pair25to convey the sheet12such that another portion of the sheet12to which another part of the image is to be recorded faces the recording head21. By alternately repeating the processes described above, an image is fully recorded onto the sheet12.

As illustrated inFIG. 1B, the front surface14A is formed with an opening85at a right end portion thereof. The casing14includes a cover87pivotally movable between a closed position (a position illustrated inFIG. 1A) closing the opening85and an open position (a position illustrated inFIG. 1B) exposing the opening85. The cover87is supported to the casing14near the lower edge thereof so as to be pivotally movable about a pivot axis extending in the left-right direction9. An accommodating space86is formed to the rear of the opening85in the casing14and is in communication with the opening85. The cartridge receiving portion110is disposed within the accommodating space86.

As illustrated inFIGS. 3 and 4, the cartridge receiving portion110includes a cartridge case101, contacts52, rods125, a locking portion129, tanks103, and liquid-level sensors55. As described above, four ink cartridges30corresponding to the colors of cyan, magenta, yellow, and black can be accommodated in the cartridge receiving portion110. Four contacts52, one rod125, one tank103, and one liquid-level sensor55are provided for each of the four ink cartridges30.

Note that the number of the ink cartridges30that can be accommodated in the cartridge receiving portion110is not limited to four. InFIG. 3, one of the four ink cartridges30is attached at a left end of the cartridge receiving portion110.

The cartridge case101constitutes a casing of the cartridge receiving portion110. The cartridge case101has a box shape formed with an interior space for accommodating four ink cartridges30. The cartridge case101has a rear wall in the front-rear direction8, and an opening112formed at a position opposing the rear wall in the front-rear direction8. The opening112exposes the interior space of the cartridge case101to an outside. Further, in the open position of the cover87, the opening112is exposed to the outside of the multifunction peripheral10through the opening85of the casing14.

Each of the four ink cartridges30is inserted rearward and extracted frontward relative to the cartridge receiving portion110through both the opening85of the casing14and the opening112of the cartridge receiving portion110. The cartridge case101includes a lower wall117formed with four guide grooves109spaced apart from one another in the left-right direction9. A lower end portion of each of the ink cartridges30is inserted into the corresponding guide groove109, and therefore the ink cartridge30can be guided in the front-rear direction8.

The cartridge case101further includes three plates104for partitioning the interior space of the cartridge case101into four spaces adjacent to each other in the left-right direction9. Each of the four spaces partitioned by the three plates104is configured to accommodate the corresponding one of the four ink cartridges storing ink of different colors.

The contacts52are provided at a top wall of the cartridge case101. Each of the contacts52protrudes downward from the top wall toward the interior space of the cartridge case101. In a state where the ink cartridge30is attached to the cartridge case101, each of the four contacts52is positioned at position in contact with a corresponding one of four electrodes152(seeFIGS. 5 and 6; described later) of the ink cartridges30. Each of the contacts52has electrical conductivity and is resiliently deformable in the up-down direction7. Each of the contacts52is electrically connected to the controller130(seeFIG. 8).

As illustrated inFIG. 4, each of the rods125protrudes frontward from the rear wall of the cartridge case101. Each of the rods125is provided at the rear wall of the cartridge case101at a position upward relative to a corresponding one of joints107(described later). In a state where the ink cartridge30is attached to the cartridge receiving portion110, the rod125is inserted into an air valve chamber36(described later) of the ink cartridge30through an air communication opening96(described later).

As illustrated inFIGS. 3 and 4, the locking portion129extends in the left-right direction9at a position adjacent to the top wall of the cartridge case101and adjacent to the opening112. The locking portion129is a bar-like member extending in the left-right direction9. The locking portion129has a columnar shape and made of metal, for example. The locking portion129has a left end fixed to a left end wall of the cartridge case101and a right end fixed to a right end wall of the cartridge case101. The locking portion129extends in the left-right direction9over the four spaces of the cartridge case101in which the four ink cartridges30are respectively accommodatable.

The locking portion129is configured to retain each of the ink cartridges30attached to the cartridge receiving portion110at an attached position illustrated inFIG. 7. The ink cartridges30are respectively configured to be engaged with the locking portion129in a state where the ink cartridges30are attached to the cartridge receiving portion110. As a result, the locking portion129retains each ink cartridge30in the cartridge receiving portion110at the attached position against urging forces of coil springs78,98(described later) that push the ink cartridge30frontward.

As illustrated inFIG. 4, the tanks103are positioned rearward of the cartridge case101. Of walls constituting each of the tanks103, a rear wall143has a portion serves as a prism55A (described later) of the liquid-level sensor55. At least this portion of the rear wall143among the walls constituting each of the tank103has a translucency to allow a light emitted from a light-emitting portion55B of the liquid-level sensor55to pass therethrough.

Each of the tanks103has a box-like shape defining therein a storage chamber121(an example of a second storage chamber). Each of the storage chambers121is in communication with the corresponding one of the ink tubes through an outlet port128. The outlet port128is formed at a position adjacent to a bottom wall of the tank103defining a lower end of the storage chamber121. The outlet port128is positioned downward of the joint107. With this configuration, ink stored in the storage chamber121flows out through the outlet port128into the ink tube, and is supplied to the recording head through the ink tube.

Each of the tanks103also includes a front wall142formed with a communication port146and a through-hole126. Each of the communication port146and the through-hole126penetrates the front wall142in the front-rear direction8. The front wall142is formed with an opening constituting a front end of the communication port146. The opening of the communication port146is closed with a semipermeable membrane147restricting ink from passing therethrough but allowing air to pass therethrough. Through the communication port146and the semipermeable membrane147, the storage chamber121is in communication with an atmosphere. The communication port146and the semipermeable membrane147is an example of a second air communicating portion. Note that the semipermeable membrane147may not be provided on the communication port146.

As illustrated inFIGS. 3 and 4, each of the joints107includes an ink needle102and a guide portion105. The ink needle102has a hollow tubular shape and made of resin. The ink needle102protrudes frontward from the tank103. The ink needle102has a protruding end formed with an opening116. The ink needle102defines therein an internal space in communication with the storage chamber121through the through-hole126. Further, the ink needle102is disposed at a position corresponding to an ink supply portion34(seeFIG. 7) of the ink cartridge30attached to the cartridge receiving portion110. The through-hole126is an example of an inlet port.

The guide portion105is a hollow cylindrical shape provided to surround the ink needle102. The guide portion105protrudes frontward from the rear wall of the cartridge case101and has a protruding end formed with an opening. The ink needle102is disposed at a diametrical center of the guide portion105. When the ink cartridge30is attached to the cartridge receiving portion110, the ink supply portion34is inserted into an interior of the guide portion105.

A valve114and a coil spring115are accommodated in the internal space of the ink needle102. The valve114is movable in the front-rear direction8between a closed position (seeFIG. 4) closing the opening116and an open position (seeFIG. 7) opening the opening116. The coil spring115urges the valve114toward the closed position, i.e., frontward. In a state where the valve114is in the closed position, a front end of the valve114protrudes further frontward relative to the opening116.

Each of the liquid-level sensors55(an example of a detecting portion) includes the prism55A, the light-emitting portion55B, and a light-receiving portion (not illustrated). Each of the liquid-level sensor55is configured to detect, using the prism55A, whether the level of the ink remaining in the storage chamber121is equal to or lower than a prescribed position P1. The prism55A provides an optical reflectivity that varies depending on whether the ink remaining in the storage chamber121is in contact with the prism55A.

In the present embodiment, the prescribed position P1 is a position the same as a center of the internal space of the ink needle102in the up-down direction7. However, the prescribed position P1 may be a position other than the position described above. For example, the prescribed position P1 may be positioned downward relative to the ink needle102but positioned upward relative to the outlet port128.

In the rear wall143defining the storage chamber121, a portion adjacent to the prescribed position P1 constitutes the prism55A. The light-emitting portion55B and the light-receiving portion are positioned rearward of the prism55A so as to oppose the prism55A. The light-emitting portion55B is configured to emit light toward the prism55A, and the light-receiving portion is configured to receive the light emitted from the light-emitting portion55B and reflected by the prism55A. The light-receiving portion is configured to output a signal based on intensity of the received light to the controller130.

When the level of the ink stored in the storage chamber121is higher than the prescribed position P1, the ink is in contact with the prism55A on an optical path of light emitted from the light-emitting portion55B. In this case, the light emitted from the light-emitting portion55B to the prism55A passes through the prism55A and enters the storage chamber121, whereby the light emitted from the light-emitting portion55B does not reach the light-receiving portion. As a result, the light-receiving portion outputs a low-level signal to the controller130.

On the other hand, when the level of the ink stored in the storage chamber121is equal to or lower than the prescribed position P1, the ink is not in contact with the prism55A on the optical path of light emitted from the light-emitting portion55B. In the latter case, light emitted from the light-emitting portion55B to the prism55A is reflected by the prism55A and the light is allowed to reach the light-receiving portion. At this time, the light-receiving portion outputs a high-level signal to the controller130.

Note that another well-known configuration may be employed as the liquid-level sensor55. For example, an arm provided with a detected portion may be provided in the storage chamber121. In this case, the arm is pivotally moved when the level of the ink in the storage chamber121is below the prescribed position P1 to displace the detected portion. As the optical sensor detects the displacement of the detected portion of the arm, whether the level of the ink is below the prescribed position P1 can be determined.

Alternatively, electrodes having bar-like shape may be used as the liquid-level sensors55. In this case, the two electrodes are mounted on a circuit board (not illustrated) and disposed in the storage chamber121. One of the two electrodes has a lower end positioned slightly upward relative to the prescribed position P1, while the remaining one of the two electrode has a lower end positioned downward relative to the prescribed position P1. Depending on whether current flows between the two electrodes through the ink stored in the storage chamber121, whether the level of the ink stored in the storage chamber121becomes equal or lower than the prescribed position P1 can be detected.

Each of the ink cartridges30(an example of a cartridge) is a container configured to store ink (an example of liquid) therein. As illustrated inFIGS. 5 and 6, the ink cartridge30includes a cartridge casing31, the ink supply portion34, a projecting portion43, and an operation portion90. The cartridge casing31has a flattened shape so that a dimension of the cartridge casing31in the left-right direction9is small, and a dimension of the cartridge casing31in the up-down direction7and a dimension of the cartridge casing31in the front-rear direction8are greater than the dimension of the cartridge casing31in the left-right direction9.

The ink cartridges30storing ink of colors different from one another may have outer shapes the same as one another, or may have outer shapes different from one another. The cartridge casing31is defined by a rear wall40, a front wall41, an upper wall39, a lower wall42, a right side wall37, and a left side wall38.

The rear wall40is constituted by a first rear wall40A, a second rear wall40B, and a third rear wall40C. The first rear wall40A is positioned frontward and upward relative to the second rear wall40B. The second rear wall40B is positioned rearward and upward relative to the third rear wall40C. Further, the third rear wall40C is positioned frontward and downward relative to the first rear wall40A. The air communication opening96is formed at the first rear wall40A. The ink supply portion34is provided at the third rear wall40C.

The projecting portion43and the operation portion90is provided on the upper wall39. The projecting portion43protrudes upward from an outer surface of the upper wall39and extends in the front-rear direction8. The projecting portion43has a lock surface62facing frontward. The lock surface62is positioned upward relative to the upper wall39. In a state where the ink cartridge30is attached to the cartridge receiving portion110, the lock surface62is in contact with the locking portion129of the cartridge receiving portion110. Contact of the lock surface62with the locking portion129allows the ink cartridge30to be retained at the attached position against the urging force of the coil springs78,98.

On the upper wall39, the operation portion90is positioned frontward relative to the lock surface62. The operation portion90has an operation surface92. When the operation surface92is pressed downward by the user in a state where the ink cartridge30is attached to the cartridge receiving portion110, the ink cartridge30is pivotally moved, and the lock surface62is moved downward relative to the locking portion129. As a result, the ink cartridge30can be removed from the cartridge receiving portion110.

As illustrated inFIG. 6, a storage chamber32, an ink valve chamber35, and the air valve chamber36are formed in an internal space of the cartridge casing31. The storage chamber32and the ink valve chamber35are configured to store ink therein. The storage chamber32and the ink valve chamber35is an example of a first storage chamber. The storage chamber32is in communication with an outside of the cartridge casing31through the air valve chamber36to open to the atmosphere.

The cartridge casing31has a partition wall44for partitioning the internal space of the cartridge casing31. The storage chamber32and the air valve chamber36are partitioned by the partition wall44to be arranged adjacent to each other in the up-down direction7. The storage chamber32and the air valve chamber36are in communication with each other via a through-hole46formed on the partition wall44. The storage chamber32and the ink valve chamber35are in communication with each other via a through-hole99.

The air valve chamber36serves as an air flow passage and is provided at a position upward relative to the storage chamber32. A labyrinth passage or a semipermeable membrane (not illustrated) may be provided at the air valve chamber36. A valve97and the coil spring98are accommodated within the air valve chamber36. The valve97is movable between a closed position (seeFIG. 6) closing the air communication opening96and an open position (seeFIG. 7) opening the air communication opening96. The coil spring98urges the valve97toward the closed position, i.e., rearward. The air valve chamber36and the valve97is an example of a first air communicating portion.

During process of attachment of the ink cartridges30to the cartridge receiving portion110, the rod125of the cartridge receiving portion110(seeFIG. 7) enters the air valve chamber36through the air communication opening96. As the rod125enters the air valve chamber36, the rod125moves the valve97in the closed position frontward against the urging force of the coil spring98. As the valve97is moved to the open position, the storage chamber32is in communication with the atmosphere through the air valve chamber36and the air communication opening96.

Note that a configuration for opening the air communication opening96may be different from the configuration in the present embodiment. For example, the air communication opening96may be sealed with a film, and the rod125may break through the film to allow the air communication opening96to open.

The ink supply portion34protrudes rearward from the third rear wall40C. The ink supply portion34has a hollow cylindrical shape. The ink supply portion34has an internal space serving as the ink valve chamber35. The ink supply portion34has a protruding end open to outside of the ink cartridge30. The second rear wall40B is positioned further rearward relative to the protruding end of the ink supply portion34. Within the ink valve chamber35, a seal member76, a valve77, and the coil spring78are accommodated.

The seal member76has a disc-like shape formed with a through-hole in a diametrical center of the seal member76. This through-hole penetrating the seal member76in the front-rear direction8functions as an ink supply port71. The ink supply port71has an inner diameter slightly smaller than an outer diameter of the ink needle102. The valve77is movable in the front-rear direction8between a closed position (seeFIG. 6) and an open position (see FIG.7) within the ink valve chamber35. In the closed position, the valve77is in abutment with the seal member76to close the ink supply port71, while in the open position, the valve77is separated from the seal member76to open the ink supply port71. The coil spring78urges the valve77in a direction toward the closed position, i.e., rearward. In a state where the valve77is at the open position, the ink stored in the ink valve chamber35flows out through the ink supply port71. On the other hand, in a state where the valve77is at the closed position, the ink is restricted from flowing out through the ink supply port71.

In the process of attaching the ink cartridge30to the cartridge receiving portion110, the ink supply port71of the ink cartridge30is connected to the ink needle102(seeFIG. 7) of the tank103. Specifically, the ink needle102is inserted into the ink valve chamber35through the ink supply port71. At this time, an outer peripheral surface of the ink needle102provides liquid-tight contact with an inner peripheral surface of the seal member76defining the ink supply port71while elastically deforming the seal member76. As the ink cartridge30is further inserted into the cartridge receiving portion110, the ink needle102moves the valve77toward the open position against the urging force of the coil spring78. The valve77causes the valve114protruding through the opening116of the ink needle102to move to the open position against the urging force of the coil spring115, thereby opening the opening116.

As a result, as illustrated inFIG. 7, the ink supply port71and the opening116are open, whereby ink is allowed to flow from the ink valve chamber35of the ink supply portion34to the internal space of the ink needle102. Accordingly, the ink stored in the storage chamber32and the ink valve chamber35can be supplied into the storage chamber121of the tank103due to hydraulic head difference. More specifically, the ink stored in the storage chamber32and the ink valve chamber35flows out through the ink supply port71, passes through the internal space of the ink needle102of the joint107connected to the ink supply portion34, and flows into the storage chamber121of the tank103through the through-hole126.

As illustrated inFIGS. 5 and 6, the ink cartridge30further includes a circuit board151positioned rearward of the projecting portion43on the outer surface of the upper wall39. The electrodes152are formed on the circuit board151. Further, the circuit board151includes a memory153(seeFIG. 8). The electrodes152are electrically connected to the memory153of the circuit board151. On an upper surface of the circuit board151, the electrodes152are exposed to an outside so as to be electrically connectable to the contacts52of the cartridge receiving portion110.

In a state where the ink cartridge30is attached to the cartridge receiving portion110, each of the electrodes152is electrically connected to the corresponding one of the contacts52. The controller130can read information from the memory153of the circuit board151and can write information into the memory153of the circuit board151through the contacts52and the electrodes152.

The memory153of the circuit board151stores therein: viscosity of the liquid ρ; an ink amount Vc (an example of a first liquid amount); a length Hc; a resistance Rc; and a function Fc.

The viscosity of the liquid ρdenotes viscosity of the ink stored in the ink cartridge30.

The ink amount Vc denotes an amount of the ink stored in the storage chamber32and the ink valve chamber35of the ink cartridge30.

The length Hc denotes a height of the level of the ink stored in the storage chamber32and the ink valve chamber35of the ink cartridges30relative to a reference position. In other words, the length Hc denotes a length in the up-down direction7between the reference position and the level of the ink stored in the storage chamber32and the ink valve chamber35of the ink cartridge30.

Here, the reference position denotes a position in the up-down direction7set in common for both the ink cartridge30and the tank103in a state where the ink cartridge30is attached to the cartridge receiving portion110. In the present embodiment, the reference position is a position the same as an imaginary line passing through the center of the internal space of the ink needle102and extending in the horizontal direction (more specifically, the front-rear direction8). That is, the prescribed position P1 serves as the reference position in the present embodiment.

The resistance Rc denotes a resistance imposed upon the air passing through the air valve chamber36.

The function Fc is information indicative of a correspondence relationship between the ink amount Vc and the length Hc. The length Hc is calculated using an expression (1) indicated below. The function Fc is preset information and uses the ink amount Vc and the length Hc as variables. The information indicative of the correspondence relationship between the ink amount Vc and the length Hc may take a format of a data table including information other than the function Fc, such as a plurality of sets of the corresponding ink amount Vc and the corresponding length Hc.
Hc=Fc(Vc)  (1)

The memory153of the circuit board151has a storage area including, for example, a first area and a second area. The first area and the second area are memory areas different from each other. Information stored in the first area is not rewritable by the controller130, while information stored in the second area is rewritable by the controller130. The first area stores therein the viscosity of the liquid ρ, the passage resistance Rc, and the function Fc. The second area stores therein the ink amount Vc and the length Hc.

The controller130is configured to control overall operations of the multifunction peripheral10. As illustrated inFIG. 8, the controller130includes a central processing unit (CPU)131, a read-only memory (ROM)132, a random-access memory (RAM)133, an electrically erasable programmable ROM (EEPROM)134, and an application-specific integrated circuit (ASIC)135. The ROM132stores programs and the like with which the CPU131controls various operations in the multifunction peripheral10. The RAM133is used as a storage area for temporarily storing data, signals, and the like used when the CPU131executes the programs. The RAM133is also used as a working area in which data processing is performed. The EEPROM134stores settings information that need be preserved after the multifunction peripheral10is turned off. The ROM132, the RAM133, the EEPROM134and the memory153of the circuit board151is an example of a memory.

The ASIC135operates the feed roller23, the conveying roller25A, the discharge roller27A, and the recording head21. The controller130causes the ASIC135to drive the motors (not illustrated) to rotate the feed roller23, the conveying roller25A, and the discharge roller27A. Further, the controller130controls the ASIC135to output drive signals to the vibrating elements of the recording head21, thereby causing the recording head21to eject ink through the nozzles29. The ASIC135is capable of outputting a plurality of kinds of drive signals in accordance with required amount of ink to be ejected through the nozzles29. The display20is connected to the ASIC135.

Further, the contacts52and the liquid-level sensors55are electrically connected to the ASIC135. The controller130provides communication with the memory153of each ink cartridge30attached to the cartridge case101through the corresponding contacts52. The controller130determines whether the level of the ink stored in each of the storage chambers121is equal to or lower than the prescribed position P1 using the corresponding one of the liquid-level sensors55.

The EEPROM134stores therein various kinds of information relating to the four ink cartridges30to be respectively attached to the cartridge case101, i.e., information relating to the tanks103to be respectively in communication with the corresponding ink cartridges30. The various kinds of information includes, for example, the ink amount Vc, an ink amount Vs (an example of a second liquid amount), the length Hc, a length Hs, the resistance Rc, a resistance Rs, a resistance Rn, the function Fc, a function Fs, and a threshold amount Vth. The resistance Rs, the resistance Rn and the function Fs may be stored in the ROM132instead of the EEPROM134.

The ink amount Vc, the length Hc, the resistance Rc, and the function Fc are information to be read by the controller130from the memory153of each ink cartridge30through the corresponding contacts52in a state where the ink cartridges30are attached to the cartridge receiving portion110.

The ink amount Vs denotes an amount of the ink stored in the storage chamber121of the tank103.

The length Hs denotes a height of the level of the ink stored in the storage chamber121of the tank103relative to the reference position described above In other words, the length Hs denotes a length in the up-down direction7between the reference position and the level of the ink stored in the storage chamber121of the tank103.

The resistance Rs denotes a resistance imposed upon the air passing through the communication port146and the semipermeable membrane147.

The resistance Rn denotes a resistance imposed upon the ink passing through the ink valve chamber35and the internal space of the ink needle102in communication with each other. In other words, the resistance Rn denotes a resistance imposed upon the ink flowing from the storage chamber32into the storage chamber121.

The function Fs is information indicative of a correspondence relationship between the ink amount Vs and the length Hs. The length Hs is calculated using an expression (2) indicated below. The function Fs is a preset function and uses the ink amount Vs and the length Hs as variables. The information indicative of the correspondence relationship between the ink amount Vs and the length Hs may take a format of a data table including information other than the function Fs, such as a plurality of sets of the corresponding ink amount Vs and the corresponding length Hs.
Hs=Fs(Vs)  (2)

The threshold amount Vth is a value regarding an ink amount preset for preventing air from passing through the outlet port128of the tank103. In the present embodiment, the threshold amount Vth is set to a value corresponding to an amount of the ink capable of being stored in a space defined between the prescribed position P1 and an upper end of the outlet port128in the storage chamber121of the tank103. InFIG. 10B, the threshold amount Vth corresponds to an amount of the ink indicated by a hatching area in the storage chamber121.

<Print Control Process Performed by Controller130>

The controller130executes a print control process to control the printer portion11configured as described above. In the print control process, the printer portion11is controlled so as to feed each of the sheets12and an image is recorded on each sheet12. Hereinafter, the print control process will be described with reference to the flowchart inFIG. 9A. Note that, in an initial state when the print control process is performed, it is assumed that the level of the ink stored in the storage chamber32of the ink cartridge30and the level of the ink stored in the storage chamber121of the tank103are the same as each other, i.e., the same as a position P2 that is above the liquid-level sensor55, as illustrated inFIG. 10A.

In the print control process according to the present embodiment, the controller130determines whether a print command (an example of a command to consume liquid) has been inputted to the controller130. The controller130waits until a print command is inputted (S10: NO). When a print command is inputted into the controller130from the operating portion28(seeFIG. 1) of the multifunction peripheral10or an external device connected to the multifunction peripheral10(S10: YES), in S20the controller130controls the feed roller23to starts feeding the sheet12supported by the feed tray15to the conveying path17.

The print command includes various information such as print data for image to be recorded onto each of the sheets12, the size of the sheets12on which the image is to be printed, margins of the sheets12on which the image is to be printed, and the number of sheets12on which the image is to be printed.

The controller130executes a printing process to print an image onto each of the sheets12(an example of a consuming process) based on the inputted print command. In the present embodiment, the process performed in a case where information included in the print command indicates that an image is to be printed onto a plurality of the sheets12and the printing process is executed based on the print command will be described.

In S30the controller130controls the conveying roller pair25to start conveyance of one sheet12. More specifically, the controller130controls the conveying roller pair25to convey the sheet12in the conveying direction so that the sheet12reaches a print starting position at which the sheet12faces the recording portion24. When the sheet12is at the print starting position, a downstream end in the conveying direction of a print region (i.e., a region of the sheet12on which an image is printed based on image data) of each sheet12faces some nozzles29arranged at positions most downstream in the conveying direction among the plurality of nozzles29.

Then, in S40the controller130performs a printing process onto the conveyed sheet12. Specifically, the controller130controls the conveying roller pair25and the recording portion24to alternately and repeatedly perform conveyance of the sheet12by the conveying roller pair25and ejection of ink droplets through the nozzles29by the recording portion24while moving the carriage22. During execution of the printing process, the ink stored in the storage chambers121of the tanks103and the ink stored in the storage chambers32of the ink cartridges30are supplied to the recording head21.

While the printing process onto the sheet12is performed, the controller130refers to a signal outputted from each of the liquid-level sensors55to the controller130. In other words, during execution of the printing process in S40, in S50the controller130determines whether the liquid-level sensor55outputs a high-level signal. When the signal outputted from the liquid-level sensor55to the controller130is a low-level signal (S50: NO), the controller130determines that the level of the ink stored in the corresponding storage chamber121is higher than the prescribed position P1. In this case, the controller130continues to control the recording portion24and the conveying roller pair25to execute the printing process until the printing process onto the sheet12has been completed (S60: NO).

When the controller130determines that the printing process onto the sheet12has been completed (S60: YES), in S70the controller130updates the ink amount Vc, the ink amount Vs, the length Hc, and the length Hs stored in the EEPROM134.

Hereinafter, updating of the ink amount Vc, the ink amount Vs, the length Hc, and the length Hs will be described in detail. At a timing before the controller130executes the process in S70, the controller130calculates ink ejection amounts Qh, Qs, and Qc (described later).

The ink ejection amount Qh denotes an ink amount which the controller130commanded the recording head21to eject for forming an image onto one sheet12. The controller130calculates the ink ejection amount Qh on a basis of the print data included in the print command. As an example, by referring to the print data, the controller130calculates, for each dot included in a print region of the sheet12, the number of types of ink droplets to be ejected in the printing process, and the number of times of ejection of ink droplets for each type. For example, ink droplets of one type are to be ejected when the target dot should be color of black, while ink droplets of one to three types are to be ejected when the target dot should be color other than black. Further, as a density of color for the target dot is increased, the number of times the ink droplets are ejected are also increased.

The controller130calculates a value for each of four types of ink droplets by multiplying the number of times the ink droplets are to be ejected onto each dot in the printing region of the sheet12. That is, the controller130calculates the ink ejection amount Qh for each of the four tanks103, i.e., each of four colors. Note that the ink ejection amount Qh for only one of the four tanks103will be described.

As shown in an expression (3) indicated below, the ink ejection amount Qh is the total of the ink ejection amount Qs and the ink ejection amount Qc. The ink ejection amount Qs denotes an amount of the ink to be supplied from the storage chamber121of the tank103to the recording head21in the printing process executed for the sheet12, and the ink ejection amount Qc denotes an amount of the ink to be supplied from the storage chamber32of the ink cartridge30to the recording head21in the printing process executed for the sheet12. The ink ejection amounts Qs and Qc are calculated using an expression (4) and an expression (5) indicated below, respectively, based on the resistances Rs, Rc, and Rn.
Qh=Qs+Qc(3)
Qs=Qh·((Rn+Rc)/(Rs+Rn+Rc))  (4)
Qc=Qh·(Rs/(Rs+Rn+Rc))  (5)

In the present embodiment, the values of the resistances Rs, Rc, and Rn are preset such that an inequation Rn+Rc>Rs is satisfied. Accordingly, in the printing process for forming an image onto the sheet12, the ink ejection amount Qs becomes greater than the ink ejection amount Qc.

In S70, based on the ink ejection amounts Qh, Qs, and Qc calculated in advance, the controller130updates a value of ink amount Vs stored in the EEPROM134to a value obtained by subtracting the ink ejection amount Qs from the ink amount Vs stored in the EEPROM134before the updating in S70(a value obtained by Vs−Qs). The controller130further updates a value of the ink amount Vc stored in the EEPROM134to a value obtained by subtracting the ink ejection amount Qc from the ink amount Vc stored in the EEPROM134before the updating in S70(a value obtained by Vc−Qc). The controller130further updates a value of the length Hs stored in the EEPROM134to a value calculated based on the updated ink amount Vs and the expression (2) described above. The controller130further updates a value of the length Hc stored in the EEPROM134to a value calculated based on the updated ink amount Vc and the expression (1) described above.

Each time the printing process for one sheet12has been completed, the controller130updates the values of the ink amount Vc, the ink amount Vs, the length Hc, and the length Hs in the present embodiment.

Then, in S80the controller130controls the discharge roller pair27to convey the sheet12in the conveying direction and to discharge the sheet12onto the discharge tray16.

Next, in S90the controller130determines whether the all of the print data included in the print command received in S10has been printed onto the sheets12. That is, in S90the controller130determines whether the sheet12that has been printed in the latest printing process is the final page.

When the sheet12that has been printed in the latest printing process is not the final page (S90: NO), the controller130returns to the process in S20, and controls the feed roller23to feed the subsequent sheet12that serves as the next page and supported by the feed tray15to the conveying path17. Then, the controller130executes the processes in S30to S80, i.e., performs a printing process for the subsequent sheet12.

On the other hand, when the sheet12that has been printed in the latest printing process is the final page (S90: YES), the controller130ends the series of processes.

Various processes, such as feeding of the subsequent sheet12serving as the next page by the feed roller23(S20), updating of the ink amount Vc, the ink amount Vs, the length Hc, and the length Hs (S70), discharge of the sheet12serving as the present page (i.e., the sheet12printed in the current printing process) (S80), and determination of whether the present page is the final page (S90) may be executed in parallel.

When the signal outputted from at least one of the liquid-level sensors55is changed from a low-level signal to a high-level signal (S50: YES), the controller130determines that the level of the ink stored in the corresponding storage chamber121has lowered to the prescribed position P1. In this case, the controller130executes the processes in S100to S160which will be described below in detail.

In S100the controller130first calculates a first volume V1 and a second volume V2.

The calculation method of the first volume V1 will be described in detail. The first volume V1 denotes an amount of the ink stored in the storage chamber32in a region above the level of the ink stored in the storage chamber121at a timing when the liquid-level sensor55detects that the level of the ink stored in the storage chamber121becomes equal to or lower than the prescribed position P1 (i.e., when the signal outputted from the liquid-level sensor55to the controller130is changed from a low-level to a high-level).

As described above, the ink ejection amount Qs becomes greater than the ink ejection amount Qc during a printing process. Accordingly, at a timing when the liquid-level sensor55detects that the ink of the level stored in the storage chamber121is equal to or lower than the prescribed position P1, the level of the ink stored in the storage chamber121is lower than the level of the ink stored in the storage chamber32. At this time, of the ink stored in the storage chamber32, an amount of the ink above the level of the ink stored in the storage chamber121is the first volume V1. The first volume V1 is an example of a first volume.

FIG. 10Billustrates the level of the ink in the storage chamber32of the ink cartridge30and the level of the ink in the storage chamber121of the tank103at a timing when the liquid-level sensor55detects lowering of the level of the ink in the storage chamber121. The first volume V1 corresponds to an ink amount indicated by a hatching area in the storage chamber32inFIG. 10B.

The controller130calculates the first volume V1 based on an expression (6) and an expression (7) indicated below. The expression (6) is an example of the claimed expression (1), and the expression (7) is an example of the claimed expression (2).
V1=V3−t1·V4  (6)
V4=(ρ·g·(Hc−Hs))/(Rc+Rs+Rn)  (7)

In the expression (6), a third volume V3 denotes an amount of the ink consumed by the recording head21since the printing process has started in response to receipt of the print command until the liquid-level sensor55detects that the level of the ink in the storage chamber121becomes to the prescribed position P1. In other words, the third volume V3 denotes an amount of the ink that has been supplied from the storage chamber121of the tank103and the storage chamber32of the ink cartridge30to the recording head21since the printing process has started in response to receipt of the print command until the liquid-level sensor55detects that the level of the ink in the storage chamber121becomes to the prescribed position P1.

For example, when a print command that commands to execute printing processes for ten sheets12is inputted to the controller130and when the liquid-level sensor55detects that the level of the ink in the storage chamber121lowers to the prescribed position P1 while the printing process for the eighth sheet12is executed, the third volume V3 denotes an amount of the ink supplied from the storage chamber32and the storage chamber121to the recording head21since the printing process for the first sheet12has started until the liquid-level sensor55detects that the level of the ink in the storage chamber121becomes equal to or lower than the prescribed position P1 while the printing process for the eighth sheet12is being executed. Similar to the ink ejection amount Qh described above, the third volume V3 is calculated based on print data included in a print command. Note that the third volume V3 may be calculated based on an amount of the ink ejected through the nozzles29of the recording head21during the printing processes.

Further, in the expression (6), a period of time t1 denotes a period of time (second(s)) that has elapsed since the printing process for the first sheet12has started until the liquid-level sensor55detects that the level of the ink in the storage chamber121becomes to the prescribed position P1. A fourth volume V4 denotes an amount of the ink supplied per unit time (second(s)) from the storage chamber32of the ink cartridge30to the storage chamber121of the tank103. The fourth volume V4 is calculated using the expression (7). In the expression (7), g denotes gravitational acceleration.

As described above, the ink ejection amounts Qs and Qc are set such that the ink ejection amount Qs becomes greater than the ink ejection amount Qc. Accordingly, as the ink is supplied from the storage chamber32of the ink cartridge30and the storage chamber121of the tank103to the recording head21, the level of the ink stored in the storage chamber121is lowered to a position below the level of the ink stored in the storage chamber32. Thereafter, however, the ink in the storage chamber32flows into the storage chamber121due to hydraulic head difference, and therefore the level of the ink stored in the storage chamber121and the level of the ink stored in the storage chamber32in the up-down direction7become identical to each other.

A value of t1·V4 in the expression (6) is indicative of an amount of the ink flowing due to hydraulic head difference from the storage chamber32to the storage chamber121since the printing process for the first sheet12has started in response to input of the print command until the liquid-level sensor55detects that the level of the ink in the storage chamber121becomes to the prescribed position P1.

The expression (7) includes the lengths Hc and Hs respectively calculated based on the ink amounts Vc and Vs. The third volume V3 denotes an amount of the consumed ink as described above. That is, in S100the controller130calculates the first volume V1 based on the ink amounts Vc and Vs and an amount of the ink consumed in the printing process for the sheets12calculated on a basis of a print command.

Next, calculation method by the controller130of the second volume V2 will be described in detail. The second volume V2 denotes an amount of the ink consumed by the recording head21since the liquid-level sensor55has performed the detection until the printing process has been completed (S90: YES) during the printing process performed in response to the print command inputted to the controller130in S10. In other words, the second volume V2 denotes an amount of the ink supplied from both the storage chamber121of the tank103and the storage chamber32of the ink cartridge30to the recording head21since the liquid-level sensor55detects that the level of the ink in the storage chamber121has lowered to the prescribed position P1 until completion of the printing process in the printing process in accordance with the print command.

For example, when a print command to execute printing processes for ten sheets12is inputted to the controller130, and when the liquid-level sensor55detects that the ink in the storage chamber121becomes equal to or lower than the prescribed position P1 while the printing process for the eighth sheet12is executed, the second volume V2 denotes an amount of the ink supplied from the storage chamber32and the storage chamber121to the recording head21since the liquid-level sensor55detects that the level of the ink in the storage chamber121becomes to the prescribed position P1 while the printing process for the eighth sheet12is executed until the printing process for the tenth sheet12has been completed. Similar to the ink ejection amount Qh described above, the second volume V2 is calculated based on print data included in a print command. The second volume V2 is an example of a second volume.

Subsequent to the process in S100, in S110the controller130determines whether the second volume V2 calculated in S100is equal to or greater than the threshold amount Vth. When the second volume V2 is smaller than the threshold amount Vth (S110: NO), in S120the controller130continues to perform the printing process for the sheet12.

On the other hand, when the second volume V2 is equal to or greater than the threshold amount Vth (S110: YES), in S130the controller130determines whether a prescribed period of time T has elapsed. When the prescribed period of time T has not yet elapsed (S130: NO), the controller130waits until the prescribed period of time T has elapsed. When the controller130determines that the prescribed period of time T has elapsed (S130: YES), the controller130advances to the process in S120, i.e., continues to perform the printing process for the sheet12.

The prescribed period of time T is a preset period of time enough to allow the ink stored in the storage chamber32above the level of the ink in the storage chamber121to flow into the storage chamber121due to the hydraulic head difference so that the ink in the storage chamber32and the level of the ink in the storage chamber121to become equal to each other.

In S140the controller130determines whether or not the printing process for the sheet12continued in S120has been completed. When the printing process for the sheet12has not yet been completed (S140: NO), the controller130returns to S120and controls the recording portion24to continue the printing process for the sheet12. When the controller130determines that the printing process for the sheet12has been completed (S140: YES), subsequently in S150the controller130determines whether the second volume V2 calculated in S100is greater than the first volume V1.

When the second volume V2 is greater than the first volume V1, i.e., an amount of the ink consumed by the recording head21after the liquid-level sensor55detects reduction of the ink in the storage chamber121is greater than the first volume V1 (S150: YES), the controller130notifies the user that the ink stored in the storage chamber32of the ink cartridge30can be no longer supplied to the storage chamber121of the tank103.

As an example of the notification method, in S160the controller130controls the display20to perform notification. Specifically, the controller130controls the display20to display thereon a message indicating that the remaining amount of ink in the storage chamber32has been decreased and the ink cannot be supplied to the storage chamber121. However, the component or method other than the display20may be employed as an example of a notifying portion that performs notification. For example, a speaker, a light emitting diode (LED) lamp, or a combination thereof can be employed. Alternatively, a communication interface including a communication IC may be used as the notifying portion. In this case, the controller130controls the communication interface to issue a notification to external devices such as a personal computer (PC), a tablet device and the like. Accordingly, the communication interface can perform the notification through the external devices. After executing the process in S120, the controller130executes the processes in S70and subsequent thereto.

Note that the controller130may perform notification in S160to notify the user of the circumstances other than the circumstance described above. For example, in a case where the liquid-level sensor55is provided such that the prescribed position P1 is higher than the ink needle102, the controller130may notify the user that the time for replacement of the ink cartridge30with a new ink cartridge30is approaching.

On the other hand, when the second volume V2 calculated in S100is equal to or smaller than the first volume V1 (S150: NO), the controller130does not perform the notification in S160described above and proceeds to the processes in S70and subsequent thereto.

Operational and Technical Advantages in First Embodiment

At a timing when the liquid-level sensor55detects that the level of the ink stored in the storage chamber121of tank103becomes equal to the prescribed position P1, there is a possibility that the level of the ink stored in the storage chamber32of the ink cartridge30is higher than the prescribed position P1. In the above case, if the controller130controls the display20to notify the user that the ink is no longer supplied from the storage chamber32to the storage chamber121based on the detection result by the liquid-level sensor55, the performed notification is an erroneous notification.

According to the present embodiment, the controller130does not control the display20to perform the notification at a timing when the liquid-level sensor55detects that the level of the ink in the storage chamber121has lowered to the prescribed position P1 (S50: YES). Instead, after the detection by the liquid-level sensor55, on the condition that the controller130determines that the ink stored in the storage chamber32in a region above the prescribed position P1 has been consumed (S150: YES), in S160the controller130controls the display20to perform the notification, thereby enabling decrease of a possibility that such an erroneous notification described above is performed.

In the expression (6) indicated above, an amount of the ink supplied from the storage chamber32of the ink cartridge30to the storage chamber121of the tank103in the printing process for the sheet12is taken into consideration. Accordingly, precision of the first volume V1 calculated in S100can be increased.

When the second volume V2 is equal to or greater than the threshold amount Vth, there is a possibility that the level of the ink stored in the storage chamber121of the tank103becomes lower than the upper end of the outlet port128during the execution of the printing process. In this case, the air may flow out through the outlet port128.

According to the present embodiment, when the second volume V2 is equal to or greater than the threshold amount Vth (S110: YES), the controller130controls the recording portion24to stop the printing process for the sheet12for the prescribed period of time T (S130: NO). During this prescribed period of time T, hydraulic head difference between the storage chamber32and the storage chamber121causes the ink in the storage chamber32to be supplied to the storage chamber121, thereby retaining the level of the ink in the storage chamber121at a position above the upper end of the outlet port128. Accordingly, this configuration allows decrease of a possibility that the air flows out of the storage chamber121through the outlet port128.

Modifications

In the first embodiment described above, when the second volume V2 is equal to or greater than the threshold amount Vth (S110: YES), in S120the controller130stops the printing process for the prescribed period of time T, and then controls the recording portion24to resume the printing process after the prescribed period of time T has elapsed (S130: YES). However, instead of stopping the printing process until the prescribed period of time T has elapsed in S130, or in addition to stopping the printing process until the prescribed period of time T has elapsed in S130, the controller130may perform a printing process for the sheet12in S120at a speed slower than usual.

For example, during execution of the printing process for the sheet12, the following methods may be employed: extending, longer than usual, a period of time since the conveying roller pair25stops conveyance of the sheet12until the carriage22starts moving; extending, longer than usual, a period of time since the carriage22stops moving until the conveying roller pair25resumes conveyance of the sheet12; and controlling the conveying roller pair25to convey the sheet12at a speed slower than usual. With the above methods, the printing process for the sheet12in S120can be executed at a speed slower than in usual.

When the second volume V2 is equal to or greater than the threshold amount Vth, the level of the ink stored in the storage chamber121of the tank103may become lower than the upper end of the outlet port128. In this case, it is likely that the air flows out through the outlet port128.

According to the above modification, when the second volume V2 is equal to or greater than the threshold amount Vth, the controller130decelerates a speed for executing a printing process for the sheet12. While the speed for executing the printing process is decelerated, an amount of the ink to be consumed per unit time becomes reduced. Meanwhile, the ink is supplied from the storage chamber32of the ink cartridge30to the storage chamber121of the tank103due to hydraulic head difference. Accordingly, a possibility that the air from flowing out through the outlet port128can be reduced.

In the first embodiment described above, when the second volume V2 is greater than the first volume V1 (S150: YES), in S160the controller130controls the display20to notify the user that the ink stored in the storage chamber32of the ink cartridge30can be no longer supplied to the storage chamber121of the tank103. However, the controller130may control the display20and the like to perform the notification when a prescribed condition other than the condition described above is satisfied.

For example, the controller130may perform the processes illustrated in the flowchart ofFIG. 9B. In, the flowchart inFIG. 9B, the controller130executes the process in S250instead of the process in S150inFIG. 9A. When the printing process for the sheet12has been completed (S140: YES), in S250the controller130determines whether the second volume V2 is greater than an amount of the ink obtained by adding a prescribed amount α to the first volume V1. Then, when the second volume V2 is greater than the amount of the ink obtained by adding the prescribed amount a to the first volume V1 (S250: YES), in S160the controller130controls the display20to perform the notification described above. The prescribed amount a is preset to, for example, an amount equivalent to ¼ (one-fourth) of the first volume V1. The prescribed amount a may be stored in the memory153of the circuit board151of the ink cartridge30or the RAM133of the controller130of the multifunction peripheral10, for example.

As described above, since the second volume V2 is calculated and determined by the controller130, the calculated second volume V2 may have a margin of error compared to an amount of the ink actually consumed by the recording portion24. According to the modification described above, the display20performs the notification provided that the second volume V2 becomes greater than a total amount of the first volume V1 and the prescribed amount α. With the above configuration, even when the second volume V2 differs from an amount of the ink actually consumed by the recording portion24, a possibility that the display20performs the erroneous notification can be decreased.

In the first embodiment described above, the controller130calculates the first volume V1 based on the expression (6) and the expression (7). However, the first volume V1 may be calculated based on expressions other than the expression (6) and the expression (7).

For example, the controller130may calculate the first volume V1 by subtracting an ink amount Vp1 from the ink amount Vc stored in the EEPROM at a timing when the liquid-level sensor55performs the detection. The ink amount Vp1 denotes an amount of the ink stored in the storage chamber121when the level of the ink in the storage chamber121is at the prescribed position P1. The ink amount Vp1 is a preset amount of ink and stored in the ROM132or the EEPROM134.

In the embodiment described above, the controller130controls the display20to perform the notification after completion of the printing process for the sheet12(S140: YES) and before the sheet12is discharged onto the discharge tray16(S80). However, the notification may be performed at a timing different from the timing described above. For example, the notification may be performed after the sheet12has been discharged.

Alternatively, the controller130may perform the notification provided that a prescribed amount of ink is consumed after the controller130determines that the second volume V2 is greater than the first volume V1. In this case, it is likely that the controller130perform the notification when executing a printing process onto a sheet12to be printed after the sheet12that has been printed at a time when the second volume V2 is determined to be greater than the first volume V1. Note that the above prescribed amount denotes an amount to be compared with an amount obtained by cumulatively adding the ink ejection amount Qh described above, and is set to an amount equivalent to the threshold amount Vth described above, for example.

In the embodiment described above, the third volume V3 indicated in the expression (6) denotes an amount of the ink consumed by the recording head21since a printing process has started in response to input of a print command to the controller130in S10until the liquid-level sensor55detects that the level of the ink in the storage chamber121becomes equal to or lower than the prescribed position P1. Further, the period of time t1 in the expression (6) denotes a period of time that has elapsed since the printing process described above has started until the liquid-level sensor55performs the detection described above. The second volume V2 denotes an amount of the ink the recording head21has consumed since the liquid-level sensor55performs the notification until the printing process in accordance with the print command has been completed.

However, the third volume V3, the period of time t1, and the second volume V2 are not limited to the amounts and the period of time employed in the embodiment described above. For example, the third volume V3 may be an amount of ink consumed by the recording head21since a printing process to one sheet12has started until the liquid-level sensor55has performed the detection during execution of the printing process onto the one sheet12. The period of time t1 may be a period of time that has elapsed since a printing process to one sheet12has started until the liquid-level sensor55has performed the detection during execution of the printing process onto the one sheet12.

Further, the second volume V2 may be an amount of the ink consumed by the recording head21since the liquid-level sensor55has performed the detection during execution of a printing process onto one sheet12until the printing process for the one sheet12has been completed. That is, the first volume V1 and the second volume V2 those are calculated based on the third volume V3 and the period of time t1 may be amounts to be calculated per each of the sheets12.

Further, in the embodiment described above, the controller130updates the ink amount Vc, the ink amount Vs, the length Hc, and the length Hs in S70each time a printing process onto one sheet12has been completed, i.e., per each of the sheets12. However, the updating of the above values may be performed at a timing different from that in the above embodiment. For example, the controller130may update the above values per one pass, or each time a print command is inputted to the controller130. In the latter case, when a print command that instructs to execute printing processes for ten sheets12has been inputted to the controller130, the controller130updates the values after the printing process for the tenth sheet12has been completed.

In the embodiment described above, ink serves as an example of liquid. However, the present disclosure may also be embodied, for example, as a device with a roller for applying a pretreatment liquid onto a recording sheet prior to ink during a printing process. In this device, the pretreatment liquid may serve as the liquid.

Second Embodiment

Next, a second embodiment of the present disclosure will be described with reference toFIGS. 11 through 12B, wherein like parts and components are designated with the same reference numerals as shown in the first embodiment to avoid duplicating description. A multifunction peripheral10according to the second embodiment includes an ink cartridge230as another example of the cartridge and a tank203.

In the first embodiment described above, the resistance values Rs, Rc, and Rn are set such that these values satisfy the inequality Rn+Rc>Rs. Further, each of the liquid-level sensors55is configured to detect whether the level of the ink stored in the storage chamber121of the corresponding tank103becomes equal to or lower than the prescribed position P1. However, in the second embodiment, the resistance values Rs, Rc, and Rn are set to satisfy an inequality Rn+Rc<Rs, and each of the liquid-level sensor is configured to detect whether the level of the ink stored in the storage chamber32of the corresponding ink cartridge230becomes equal to or lower than a prescribed position P3.

Each of the ink cartridges230according to the second embodiment includes a liquid-level sensor255including a prism255A, a light-emitting portion255B, and a light-receiving portion (not illustrated). The liquid-level sensor255is another example of the detecting portion. Of a front wall241of the ink cartridge230that defines the storage chamber32, a portion adjacent to the prescribed position P3 serves as the prism255A, as illustrated inFIGS. 12A and 12B. The light-emitting portion255B and the light-receiving portion are disposed to the front of the prism255A and face the prism255A. With this configuration, the liquid-level sensor255can detect whether the level of the ink stored in the storage chamber32of the ink cartridges230becomes equal to or lower than the prescribed position P3.

FIG. 11is a flowchart illustrating steps in a printing control process executed by a controller130according to the second embodiment. The flowchart inFIG. 11is generally identical to the flowchart inFIG. 9Aused in the first embodiment. Accordingly, in the description as to the flowchart inFIG. 11, processes that differ from the processes in the flowchart inFIG. 9Awill be described, while omitting description as to the processes the same as those in the flowchart inFIG. 9A.

In the following description, in an initial state when the controller130executes the printing control process, the level of the ink stored in the storage chamber32of the ink cartridge230and the level of the ink stored in the storage chamber121of the tank203are assumed to be aligned with each other at a position P4 that is higher than the liquid-level sensor255, as illustrated inFIG. 12A.

In the flowchart inFIG. 11, the processes in S100and S150of the flowchart inFIG. 9Aare replaced with processes in S300and S310, respectively. Further, in the flowchart inFIG. 11, the processes in S110and S130of the flowchart inFIG. 9Aare not executed.

In S300, the controller130calculates a fifth volume V5 and a sixth volume V6.

Calculation method of the fifth volume V5 by the controller130will be described in detail. As described above, the resistance values Rs, Rc and Rn are set to satisfy the inequality Rn+Rc<Rs in the second embodiment. Accordingly, different from the first embodiment described above, the ink ejection amount Qc becomes greater than the ink ejection amount Qs. That is, at a time when the liquid-level sensor255detects that the level of the ink stored in the storage chamber32has lowered to the prescribed position P3, the level of the ink stored in the storage chamber32is lower than the level of the ink stored in the storage chamber121. At this time, an amount of the ink stored in the storage chamber121at a region above the level of the ink stored in the storage chamber32is the fifth volume V5. The fifth volume V5 is another example of the first volume.

FIG. 12Billustrates the level of the ink stored in the storage chamber32of the ink cartridge230and the level of the ink stored in the storage chamber121of the tank203at the time when the liquid-level sensor255detects that the level of the ink in the storage chamber32becomes equal to or lower than the prescribed position P3. The fifth volume V5 in the second embodiment corresponds to an ink amount indicated by a hatching area inFIG. 12B. Similar to the first volume V1 in the first embodiment described above, the fifth volume V5 can be calculated based on the expression (6) and the expression (7).

The sixth volume V6 is similar to the second volume V2 in the first embodiment. The sixth volume V6 is calculated in a similar manner to the second volume V2. The sixth volume V6 is another example of the second volume.

Note that the ink amounts and the ink ejection amounts other than the fifth volume V5 and the sixth volume V6 in the second embodiment can be calculated in a manner the same as the first embodiment described above.

In S310, the controller130compares the fifth volume V5 with the sixth volume V6 calculated in S300and determines whether the sixth volume V6 is greater than the fifth volume V5. When the sixth volume V6 is greater than the fifth volume V5, i.e., when an amount of the ink consumed by the recording head21since the liquid-level sensor255detects that the level of the ink in the storage chamber32has lowered to the prescribed position P3 until the printing process to all of the sheets12in response to the inputted print command has been completed is greater than the fifth volume V5 (S310: YES), in S160the controller130controls the display20to notify the user that the ink stored in the storage chamber32of the ink cartridge30can be no longer supplied to the storage chamber121of the tank103, for example. Thereafter, the controller130executes the processes in S70and subsequent thereto as in the first embodiment.

On the other hand, when the sixth volume V6 calculated in S300is equal to or smaller the fifth volume V5 (S310: NO), the controller130proceeds to the process S70and the processes subsequent thereto without controlling the display20to perform the notification in S160.

The modifications to the first embodiment can be also applied to the second embodiment.

When the level of the ink stored in the storage chamber32of the ink cartridge230has lowered to the prescribed position P3, there is a possibility that the level of the ink stored in the storage chamber121of the tank203is higher than the prescribed position P3. In a case where the controller130controls the display20to notify the user that the ink cannot be supplied from the storage chamber32to the storage chamber121based on the detection result by the liquid-level sensor255despite that the level of the ink stored in the storage chamber121is higher than the prescribed position P3, the performed notification is an erroneous notification.

This is because, after the liquid-level sensor255detects that the level of the ink stored in the storage chamber32becomes equal to or lower than the prescribed position P3, the ink stored in the storage chamber121of the tank203flows back to the storage chamber32of the ink cartridge230due to hydraulic head difference between the storage chamber121and the storage chamber32, thereby allowing the level of the ink in the storage chamber32to become higher than the prescribed position P3.

According to the second embodiment, the controller130does not cause the display20to perform the notification when the controller130determines through the liquid-level sensor255that the level of the ink in the storage chamber32becomes equal to or lower than the prescribed position P3. Instead, the controller130causes the display20to perform the notification on the condition that the ink stored in the storage chamber121above the prescribed position P3 has been consumed after the determination. Accordingly, this configuration can prevent erroneous notification described above.

While the description has been made in detail with reference to the embodiment(s) thereof, it would be apparent to those skilled in the art that many modifications and variations may be made therein without departing from the spirit of the disclosure.