Image recording apparatus

Abstract

To provide an image recording device that can achieve a residual quantity determination which is hardly influenced by bubble of liquid in a storage part.SOLUTION: A controller 130 of a complex machine 10 obtains an elapsed time T after previous printing, in response of receiving a printing command; determines whether liquid level is below a predetermined position on the basis of a signal that is output by a liquid level sensor 95 before a carriage 40 moves, under the condition that the elapsed time T exceeds a threshold Th_t; determines whether the liquid level is below the predetermined position on the basis of a first count value corresponding to decreases of ink 99, under the condition that the elapsed time T does not exceed the threshold Th_t; and executes a notification indicating that residual quantities of the ink 99 in an operation part 17 are small, under the condition that the liquid level is determined to be below the predetermined position.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to an image recording apparatus having a head that discharges a liquid supplied from a storage unit.

Background Art

[0002] A so-called on-carriage type image recording apparatus in which a head and an ink cartridge are mounted on a carriage is known. The remaining amount of ink stored in the ink cartridge is determined based on a signal output from an optical sensor that receives reflected light of light emitted toward the ink cartridge (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the ink cartridge moves together with the carriage, the ink in the ink cartridge may foam. In the ink cartridge, when ink bubbles adhere to the portion irradiated with light for remaining amount detection, light reflection similar to the state where the ink is full may occur even though the ink does not actually fill up to that portion. When the remaining amount of ink is determined based on the signal of the optical sensor that has received this reflected light, a determination result different from the actual remaining amount of ink may be obtained.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a means for realizing a remaining amount determination that is hardly affected by foaming of the liquid in the storage unit.

Means for Solving the Problems

[0006] (1) The image recording apparatus according to the present invention includes a carriage movable in a first direction, a head mounted on the carriage and having a plurality of nozzles for discharging liquid, a storage unit mounted on the carriage for supplying the stored liquid to the head, a sensor for detecting the liquid level of the liquid stored in the storage unit, a transport mechanism for transporting a recording medium in a second direction intersecting the first direction, a notification unit, a memory for storing a threshold value, and a controller. The controller counts a first count value corresponding to the decrease amount of the liquid stored in the storage unit, including the liquid amount discharged from the plurality of nozzles, and stores it in the memory. In response to receiving a command, the controller moves the carriage in the first direction, obtains the elapsed time since the end of the previous movement of the carriage in response to receiving a command, and determines whether the liquid level of the liquid stored in the storage unit is below a predetermined position based on the signal output by the sensor before moving the carriage, on the condition that the obtained elapsed time exceeds the threshold value. On the condition that the obtained elapsed time does not exceed the threshold value, it determines whether the liquid level of the liquid stored in the storage unit is below a predetermined position based on the first count value stored in the memory. On the condition that it is determined that the liquid level of the liquid stored in the storage unit is below a predetermined position, the notification unit executes a notification indicating that the remaining amount of the liquid is low.

[0007] In the image recording apparatus, when the elapsed time has passed the threshold value, the controller determines the liquid level of the liquid stored in the storage unit based on the signal output by the sensor before moving the carriage. Thereby, it is possible to realize the determination of the liquid level by the output of the sensor in a state where there is no foaming of the liquid in the storage unit. When the elapsed time has not passed the threshold value, the controller determines the liquid level of the liquid stored in the storage unit based on the first count value. Thereby, it is possible to realize the determination of the liquid level without depending on the output of the sensor in a state where foaming of the liquid occurs in the storage unit.

[0008] (2) Preferably, the memory stores a plurality of threshold values with different values, and the controller causes the memory to store the amount of movement of the carriage by the command, and selects one threshold value from the plurality of threshold values based on the amount of movement of the immediately preceding carriage.

[0009] According to this configuration, the larger the amount of movement of the carriage, the more likely it is that foaming occurs in the storage unit, so a threshold value corresponding to the time required for the foaming to disappear in the storage unit can be selected.

[0010] (3) Preferably, the memory stores a plurality of threshold values with different values, and the controller acquires liquid information indicating the type of the liquid stored in the storage unit, and selects one threshold value from the plurality of threshold values based on the acquired liquid information.

[0011] According to this configuration, since the likelihood of foaming in the storage unit varies depending on the type of the liquid, a threshold value corresponding to the time required for the foaming to disappear in the storage unit can be selected.

[0012] (4) Preferably, the memory stores the value of a determination flag and an empty threshold value, and the controller updates the determination flag from a first value to a second value in response to determining that the liquid level of the liquid stored in the storage unit is below a predetermined position, and, on the condition that the determination flag is the second value, counts a second count value corresponding to the amount of decrease of the liquid stored in the storage unit, including the amount of liquid discharged from the plurality of nozzles, without determining whether the liquid level of the liquid stored in the storage unit is below the predetermined position, and stores the second count value in the memory, and does not execute the discharge of the liquid from the plurality of nozzles on the condition that the second count value has reached the empty threshold value.

[0013] According to this configuration, the entry of air from the storage unit into the nozzles is suppressed.

[0014] (5) Preferably, the controller causes the notification unit to notify an error on the condition that the second count value reaches the empty threshold value.

[0015] According to this configuration, based on the error notification, the user can recognize that the discharge of the liquid from the nozzle has stopped.

[0016] (6) Preferably, in response to receiving the command, the controller performs image recording in which the carriage moves in the first direction and discharges liquid from the plurality of nozzles as the movement of the carriage in the first direction, obtains the elapsed time since the previous image recording ended as the elapsed time since the previous movement of the carriage ended in response to receiving the command, and determines whether the liquid level of the liquid stored in the storage unit is below a predetermined position based on the signal output by the sensor before starting the image recording as the timing before moving the carriage on the condition that the obtained elapsed time exceeds the threshold value.

[0017] (7) Preferably, on the condition that the obtained elapsed time exceeds the threshold value, the controller determines whether the liquid level of the liquid stored in the storage unit is below a predetermined position based on the signal output by the sensor before discharging the liquid from the plurality of nozzles for image recording as the timing before starting the image recording.

Advantages of the Invention

[0018] According to the present invention, it is possible to realize a remaining amount determination that is less affected by the foaming of the liquid in the storage unit.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, embodiments of the present invention will be described. It should be noted that the embodiments described below are merely examples of the present invention, and it goes without saying that the embodiments of the present invention can be appropriately changed without departing from the gist of the present invention. In the following description, the progression from the starting point to the ending point of an arrow is expressed as the direction, and the movement back and forth on the line connecting the starting point and the ending point of the arrow is expressed as the orientation. In the following description, the vertical direction 7 is defined based on the state in which the multifunction machine 10 is installed for use (the state in FIG. 1), the front-rear direction 8 is defined with the surface provided with the opening 13 as the front surface 23, and the left-right direction 9 is defined when viewing the multifunction machine 10 from the front. The vertical direction 7, the front-rear direction 8, and the left-right direction 9 are orthogonal to each other.

[0021] [Overall Structure of Multifunction Machine 10] As shown in FIG. 1, the multifunction machine 10 (an example of an image recording apparatus) has a housing 14 having a substantially rectangular parallelepiped shape. A printer unit 11 is provided at the lower part of the housing 14. The multifunction machine 10 has various functions such as a facsimile function and a print function. As a print function, the multifunction machine 10 has a function of recording an image on one side of a sheet of paper 12 (see FIG. 2, an example of a recording medium) by an inkjet method. Note that the multifunction machine 10 may record images on both sides of the sheet of paper 12. An operation unit 17 (an example of a notification unit) is provided at the upper part of the housing 14. The operation unit 17 is composed of buttons operated for instructions for image recording and various settings, a liquid crystal display on which various information is displayed, and the like. In the present embodiment, the operation unit 17 is composed of a touch panel having the functions of both buttons and a liquid crystal display.

[0022] As shown in FIG. 2, the printer unit 11 includes a feed tray 20, a feed unit 16, an outer guide member 18, an inner guide member 19, a pair of conveyance rollers 59, a pair of discharge rollers 44, a platen 42, a recording unit 24, an encoder 35 (see FIG. 6), a rotary encoder 75 (see FIG. 6), a controller 130 (see FIG. 6), and a memory 140 (see FIG. 6). These are arranged inside the housing 14. Inside the housing 14, various state sensors (not shown) that detect the state of the multifunction machine 10 and output a signal according to the detection result are arranged.

[0023] [Paper Feed Tray 20] As shown in FIG. 1, an opening 13 is formed in the front surface 23 of the printer unit 11. The paper feed tray 20 can be inserted into and removed from the housing 14 through the opening 13 by moving in the front-rear direction 8. The paper feed tray 20 is movable between a paper feed position (the position shown in FIGS. 1 and 2) attached to the housing 14 and a non-paper feed position withdrawn from the housing 14. The paper feed tray 20 moves to the paper feed position by being inserted rearward into the housing 14, and moves to the non-paper feed position by being pulled forward from the housing 14.

[0024] The paper feed tray 20 is a box-shaped member with an open top for accommodating the paper 12. As shown in FIG. 2, the paper 12 is supported on the bottom plate 22 of the paper feed tray 20 in a stacked state. A discharge tray 21 is disposed above the front portion of the paper feed tray 20. The paper 12 that has been image-recorded and discharged by the recording unit 24 is supported on the upper surface of the discharge tray 21. When the paper feed tray 20 is in the paper feed position, the paper 12 supported by the paper feed tray 20 can be fed to the conveyance path 65.

[0025] [Paper Feed Unit 16] As shown in FIG. 2, the paper feed unit 16 is disposed below the recording unit 24 and above the bottom plate 22 of the paper feed tray 20. The paper feed unit 16 includes a paper feed roller 25, a paper feed arm 26, a drive transmission mechanism 27, and a shaft 28. The paper feed roller 25 is rotatably supported at the tip of the paper feed arm 26. The paper feed arm 26 pivots in the direction of arrow 29 about a shaft 28 provided at the base end. Thereby, the paper feed roller 25 can contact and separate from the paper feed tray 20 or the paper 12 supported by the paper feed tray 20.

[0026] The paper feed roller 25 rotates by having the driving force of a paper feed motor 102 (see FIG. 6) transmitted thereto by a drive transmission mechanism 27 in which a plurality of gears are meshed. As a result, among the sheets of paper 12 supported on the bottom plate 22 of the paper feed tray 20 at the paper feed position, the uppermost sheet of paper 12 in contact with the paper feed roller 25 is fed to the conveyance path 65. Note that the drive transmission mechanism 27 is not limited to a form in which a plurality of gears are meshed, and may be, for example, a belt stretched between a shaft 28 and the shaft of the paper feed roller 25.

[0027] [Conveyance path 65] As shown in FIG. 2, the conveyance path 65 extends from the rear end portion of the paper feed tray 20. The conveyance path 65 includes a curved portion 33 and a straight portion 34. The curved portion 33 extends so as to make a U-turn from the rear to the front while heading upward. The straight portion 34 extends generally along the front-rear direction 8.

[0028] The curved portion 33 is formed by an outer guide member 18 and an inner guide member 19 that face each other with a predetermined interval therebetween. The outer guide member 18 and the inner guide member 19 extend in the left-right direction 9. The straight portion 34 is formed by the recording unit 24 and the platen 42 that face each other with a predetermined interval therebetween at the position where the recording unit 24 is disposed.

[0029] The sheet of paper 12 supported on the paper feed tray 20 is conveyed through the curved portion 33 by the paper feed roller 25 and reaches the pair of conveyance rollers 59. The sheet of paper 12 sandwiched by the pair of conveyance rollers 59 is conveyed forward toward the recording unit 24 through the straight portion 34. The sheet of paper 12 that has reached directly below the recording unit 24 is image-recorded by the recording unit 24. The sheet of paper 12 on which the image has been recorded is conveyed forward through the straight portion 34 and discharged to the discharge tray 21. As described above, the sheet of paper 12 is conveyed along the conveyance direction 15 indicated by the dashed-dotted arrow in FIG. 2.

[0030] [Pair of conveyance rollers 59 and pair of discharge rollers 44] As shown in FIG. 2, a pair of conveyance rollers 59 is disposed in the straight portion 34. A pair of discharge rollers 44 is disposed downstream of the pair of conveyance rollers 59 in the conveyance direction 15 in the straight portion 34.

[0031] The conveying roller pair 59 includes a conveying roller 60 and a pinch roller 61 disposed facing the conveying roller 60 below the conveying roller 60. The pinch roller 61 is pressed against the conveying roller 60 by an elastic member (not shown) such as a coil spring. The conveying roller pair 59 can sandwich the sheet 12.

[0032] The discharging roller pair 44 includes a discharging roller 62 and a boosting roller 63 disposed facing the discharging roller 62 above the discharging roller 62. The boosting roller 63 is pressed toward the discharging roller 62 by an elastic member (not shown) such as a coil spring. The discharging roller pair 44 can sandwich the sheet 12.

[0033] The conveying roller 60 and the discharging roller 62 are rotated by applying a driving force from a conveying motor 101 (see FIG. 6). When the conveying roller 60 rotates with the sheet 12 sandwiched between the conveying roller pair 59, the sheet 12 is conveyed in the conveying direction 15 by the conveying roller pair 59 and conveyed onto the platen 42. When the discharging roller 62 rotates with the sheet 12 sandwiched between the discharging roller pair 44, the sheet 12 is conveyed in the conveying direction 15 by the discharging roller pair 44 and discharged onto the discharge tray 21. Note that a common motor may be used as the conveying motor 101 and the feeding motor 102. In this case, the driving transmission path from the common motor to each roller is configured to be switchable.

[0034] In the present embodiment, the conveying motor 101, the conveying roller pair 59, and the discharging roller pair 44 constitute a conveying mechanism that conveys the sheet 12 in a direction (an example of the second direction) intersecting the left - right direction 9 (an example of the first direction). Note that what conveys the sheet 12 is not limited to the roller pairs as described above. For example, a conveying belt may be disposed instead of the conveying roller pair 59 and the discharging roller pair 44.

[0035] [Platen 42] As shown in FIG. 2, the platen 42 is disposed in the straight portion 34 of the conveyance path 65. The platen 42 faces the recording unit 24 in the vertical direction 7. The platen 42 supports the sheet 12 conveyed through the conveyance path 65 from below. The sheet 12 conveyed through the conveyance path 65 passes through the media passage area 36 (see FIG. 3) between the right end and the left end of the platen 42 in the left-right direction 9.

[0036] [Recording unit 24] As shown in FIG. 2, the recording unit 24 is disposed facing the platen 42 above the platen 42. The recording unit 24 includes a carriage 40, a head 38, and a storage unit 80.

[0037] The carriage 40 is movably supported along the left-right direction 9 orthogonal to the conveyance direction 15 by two guide rails 56 and 57 spaced apart in the front-rear direction 8. The carriage 40 is movable in the left-right direction 9 from a position to the right of the media passage area 36 to a position to the left of the media passage area 36. Note that the moving direction of the carriage 40 is not limited to the left-right direction 9 and may be any direction intersecting the conveyance direction 15.

[0038] The guide rail 56 is disposed upstream of the head 38 in the conveyance direction 15. The guide rail 57 is disposed downstream of the head 38 in the conveyance direction 15. The guide rails 56 and 57 are supported by a pair of side frames (not shown) disposed outside the straight portion 34 of the conveyance path 65 in the left-right direction 9. The carriage 40 moves by being imparted with a driving force from a carriage driving motor 103 (see FIG. 6).

[0039] An encoder 35 (see FIG. 6) is disposed on the guide rail 56 or the guide rail 57. The encoder 35 includes an encoder strip extending in the left - right direction 9, and an optical sensor provided at a position on the carriage 40 facing the encoder strip. The encoder strip is marked with a pattern in which light - transmitting portions for transmitting light and light - blocking portions for blocking light are alternately arranged at equal pitches in the left - right direction 9. By detecting the light - transmitting portions and the blocking portions with the optical sensor, a pulse signal is detected. The pulse signal is a signal corresponding to the position of the carriage 40 in the left - right direction 9. The pulse signal is output to a controller 130 (see FIG. 6).

[0040] The head 38 is supported by the carriage 40. The lower surface 68 of the head 38 is exposed downward and faces the platen 42. The head 38 includes a plurality of nozzles 39, an ink flow path 37, and a piezoelectric element 45 (see FIG. 6).

[0041] The plurality of nozzles 39 are opened on the lower surface 68 of the head 38. The ink flow path 37 connects the storage portion 80 and the plurality of nozzles 39. The piezoelectric element 45 discharges ink droplets downward from the nozzles 39 by deforming a part of the ink flow path 37. The piezoelectric element 45 operates by being supplied with power by the controller 130. Thus, the head 38 is mounted on the carriage 40 and has a plurality of nozzles 39 for discharging ink (an example of a liquid).

[0042] The storage portion 80 is supported by the carriage 40 in a state of being installed on the carriage 40. The storage portion 80 has an internal space 81. Ink 99 is stored in the internal space 81. In the present embodiment, the recording unit 24 includes one storage portion 80. Black ink 99 is stored in this one storage portion 80. Note that the color of the ink 99 stored in the storage portion 80 is not limited to black.

[0043] The storage portion 80 is located above the head 38. In this embodiment, all of the storage portion 80 is located above the head 38. However, a part of the storage portion 80 may be located above the head 38, and the portion other than the said part of the storage portion 80 may be located at a height below the head 38. The internal space 81 of the storage portion 80 communicates with a plurality of nozzles 39 via the ink flow path 37. Thereby, the ink 99 is supplied from the internal space 81 to the nozzles 39. Thus, the storage portion 80 is mounted on the carriage 40 and supplies the stored ink 99 to the head 38.

[0044] An injection port 83 for injecting the ink 99 into the internal space 81 is provided in the upper wall 82 of the storage portion 80. The injection port 83 penetrates the upper wall 82 in the thickness direction and communicates the internal space 81 with the outside of the storage portion 80. A protruding wall 84 is provided around the injection port 83 on the upper surface of the upper wall 82 (see FIG. 3). When the lid 85 is fitted to the protruding wall 84, the injection port 83 is closed. When the lid 85 is removed from the protruding wall 84, the injection port 83 is exposed to the outside. In this state, a bottle (not shown) is inserted into the injection port 83, and the ink is injected from the bottle into the internal space 81 through the injection port 83. Note that the injection port 83 may be provided on other than the upper wall 82 as long as it is at a position communicating the upper part of the internal space 81 with the outside.

[0045] [Rotating member 90] As shown in FIGS. 3 to 5, a rotating member 90 is disposed in the internal space 81 of the storage portion 80. The rotating member 90 includes a float 91, a shaft 92, an arm 93, and a detected portion 94. The float 91 is located at the lower part of the rotating member 90. The float 91 is formed of a material having a specific gravity smaller than that of the ink stored in the storage portion 80. The shaft 92 protrudes along the front-rear direction 8 from the front surface and the rear surface of the float 91. The shaft 92 is inserted into holes (not shown) formed in the front wall 88 (see FIG. 2) and the rear wall 89 (see FIG. 2) of the storage portion 80. Thereby, the rotating member 90 is rotatably supported about the shaft 92.

[0046] The arm 93 protrudes substantially upward from the float 91. The detected portion 94 is formed at the tip of the arm 93. The detected portion 94 is configured in a plate shape extending in the vertical direction 7 and the horizontal direction 9. The detected portion 94 is formed of a material that blocks the light output from the light emitting portion of the liquid level sensor 95 described later.

[0047] Figures 3 to 5 show the rotating member 90 when the liquid level of the ink 99 is at or below a predetermined position (hereinafter referred to as the near empty position) in the vertical direction 7. When the liquid level of the ink 99 is above the near empty position in the vertical direction 7, the rotating member 90 is positioned at a position where the arm 93 is substantially upright by the buoyant force acting on the float 91 (not shown). On the other hand, when the ink 99 stored in the storage portion 80 is consumed and the liquid level of the ink 99 drops, and the liquid level of the ink 99 reaches the near empty position in the vertical direction 7, the rotating member 90 rotates about the shaft 92 following the liquid level, and the arm 93 is positioned at a position inclined from the vertical direction 7 (see Figures 3 to 5).

[0048] [Liquid level sensor 95] The liquid level sensor 95 (an example of a sensor) detects a change in the state of the rotating member 90. The liquid level sensor 95 includes a light emitting portion and a light receiving portion, and is provided outside the storage portion 80. For example, the light emitting portion is provided on the front wall 88 (see Figure 2) of the storage portion 80, and the light receiving portion is provided on the rear wall 89 (see Figure 2) of the storage portion. The positions of the light emitting portion and the light receiving portion in the vertical direction 7 and the horizontal direction 9 are the same as the positions of the detected portion 94 in the vertical direction 7 and the horizontal direction when the arm 93 is substantially upright, respectively. In other words, when the arm 93 is substantially upright (that is, when the liquid level of the ink 99 is above the near empty position in the vertical direction 7), the detected portion 94 of the rotating member 90 is interposed between the light emitting portion and the light receiving portion of the liquid level sensor 95.

[0049] The liquid level sensor 95 outputs signals of different levels according to whether the light output from the light emitting part is received by the light receiving part. For example, when the light output from the light emitting part cannot be received by the light receiving part of the liquid level sensor 95 (that is, the received light intensity is less than a predetermined intensity), the liquid level sensor 95 outputs a low-level signal (referring to "a signal whose signal level is less than the threshold level") to the controller 130. On the other hand, when the light output from the light emitting part can be received by the light receiving part of the liquid level sensor 95 (that is, the received light intensity is greater than or equal to a predetermined intensity), the liquid level sensor 95 outputs a high-level signal (referring to "a signal whose signal level is greater than or equal to the threshold level") to the controller 130.

[0050] When the arm 93 is substantially upright, the detected part 94 is interposed between the light emitting part and the light receiving part of the liquid level sensor 95. Therefore, when the liquid level of the ink 99 is above the near-empty position in the vertical direction 7, the light output from the light emitting part cannot be received by the light receiving part, so the liquid level sensor 95 outputs a low-level signal to the controller 130. At this time, the liquid level sensor 95 is off.

[0051] On the other hand, when the arm 93 is tilted from the vertical direction 7, the detected part 94 is at a position retracted from between the light emitting part and the light receiving part of the liquid level sensor 95 (see FIGS. 3 to 5). Therefore, when the liquid level of the ink 99 is below the near-empty position in the vertical direction 7, the light output from the light emitting part can be received by the light receiving part, so the liquid level sensor 95 outputs a high-level signal to the controller 130. At this time, the liquid level sensor 95 is on.

[0052] [Cap 70] As shown in FIGS. 3 to 5, a cap 70 is provided outside the platen 42 in the left-right direction 9 (on the right side of the platen 42 in this embodiment). That is, the cap 70 is located outside the medium passage area 36 in the left-right direction 9. When the carriage 40 is at a standby position to the right of the medium passage area 36 (the positions shown in FIGS. 3 and 4), the cap 70 is located below the carriage 40 and faces the carriage 40 (specifically, the nozzles 39 of the head 38).

[0053] The cap 70 is a box-shaped member with an open top. The cap 70 is made of an elastic material such as rubber. The cap 70 is supported by the frame 46 via a known movable mechanism 71, and can move up and down by the movable mechanism 71 to which a driving force is applied from a cap driving motor 104 (see FIG. 6). The frame 46 is located to the right of the platen 42 and is a plate-shaped member extending in the front-rear direction 8 and the left-right direction 9. The movable mechanism 71 is, for example, a mechanism using a ball screw or a mechanism using a cam. The cap 70 can move up and down between the covering position shown in FIG. 3 and the separated position shown in FIG. 4. As shown in FIG. 3, the upper end of the cap 70 at the covering position is pressed against the lower surface 68 of the head 38 from below. Thereby, the cap 70 is in a state of covering a plurality of nozzles 39 opened in the lower surface 68 from below. The separated position is a position lower than the covering position. The cap 70 at the separated position is separated from the lower surface 68 of the head 38.

[0054] A through hole 72 is provided in the bottom surface 70A of the cap 70. One end of a tube 73 is connected to the through hole 72. The other end of the tube 73 is connected to a waste ink tank (not shown) via a pump (not shown). The tube 73 is a flexible resin tube. When the cap 70 is in the covering position and covers the nozzles 39, when the pump is driven, the ink and foreign matter in the nozzles 39 are sucked and discharged to the cap 70. The cap 70 receives the ink and foreign matter. The ink and foreign matter received by the cap 70 are sucked into the tube 73 and discharged to the waste ink tank through the tube 73.

[0055] By performing the above operation with the internal space 81 of the storage unit 80 in a sealed state, a suction purge can be performed to discharge ink and foreign matter from the plurality of nozzles 39. Further, when the ink supply path connected to the storage unit 80 has an air release port (not shown), with the air release port in an open state and the cap 70 covering the air release port, an exhaust purge can be performed to exhaust unnecessary air present in the ink supply path by driving the pump. In the exhaust purge, in addition to air, ink and foreign matter are also discharged from the air release port.

[0056] [Rotary encoder 75] The rotary encoder 75 shown in FIG. 6 includes an encoder disk provided on the shaft of the conveyance motor 101 (see FIG. 6) and rotating together with the conveyance motor 101, and an optical sensor. A pattern in which a transmission portion through which light is transmitted and a non-transmission portion through which light is not transmitted are alternately arranged at equal pitches in the circumferential direction is formed on the encoder disk. When the encoder disk rotates, a pulse signal is generated each time the transmission portion and the non-transmission portion are detected by the optical sensor. The generated pulse signal is output to the controller 130 (see FIG. 6). The controller 130 calculates the rotation amount of the conveyance motor 101 based on the pulse signal. Note that the rotary encoder 75 may be provided on, for example, the feeding motor 102 or the conveyance roller 60 other than the conveyance motor 101.

[0057] [Controller 130 and memory 140] Hereinafter, with reference to FIG. 6, the configurations of the controller 130 and the memory 140 will be described. The controller 130 controls the overall operation of the multifunction machine 10. The controller 130 includes a CPU 131 and an ASIC 135. The memory 140 includes a ROM 132, a RAM 133, and an EEPROM 134. The CPU 131, the ASIC 135, the ROM 132, the RAM 133, and the EEPROM 134 are connected by an internal bus 137.

[0058] The ROM 132 stores programs and the like for the CPU 131 to control various operations. The RAM 133 is a storage area for temporarily recording data, signals, etc. used when the CPU 131 executes the above programs, or is used as a work area for data processing. The EEPROM 134 stores settings, flags, etc. that should be retained even after the power is turned off. The EEPROM 134 stores a threshold value related to the elapsed time since the previous printing, a first count value, a table storing a plurality of threshold values related to the first count value, a second count value, a threshold value related to the second count value, a near-empty flag, and a print stop flag, etc. (details will be described later). The threshold value related to the elapsed time since the previous printing, the table storing a plurality of threshold values related to the first count value, and the threshold value related to the second count value may be stored in the ROM 132.

[0059] The ASIC 135 has a conveyance motor 101, a feeding motor 102, a carriage drive motor 103, and a cap drive motor 104 connected thereto. The ASIC 135 incorporates drive circuits for controlling each motor. The CPU 131 outputs drive signals for rotating each motor to the drive circuits corresponding to the respective motors. The drive circuits output drive currents corresponding to the drive signals acquired from the CPU 131 to the corresponding motors. Thereby, the corresponding motors rotate. That is, the controller 130 controls the feeding motor 102 to feed the paper 12 to the feeding unit 16. Further, the controller 130 controls the conveyance motor 101 to convey the paper 12 to the conveyance roller pair 59 and the discharge roller pair 44. Further, the controller 130 controls the carriage drive motor 103 to move the carriage 40. Further, the controller 130 controls the cap drive motor 104 to move the cap 70 in the vertical direction 7.

[0060] In addition, an optical sensor of the rotary encoder 75 is connected to the ASIC 135. The controller 130 calculates the rotation amount of the conveyance motor 101 based on the electrical signal received from the optical sensor of the rotary encoder 75. Also, an encoder 35 is connected to the ASIC 135. The controller 130 recognizes the position of the carriage 40 and the presence or absence of movement based on the pulse signal received from the encoder 35.

[0061] Also, a piezoelectric element 45 is connected to the ASIC 135. The piezoelectric element 45 operates by being powered by the controller 130 via a drive circuit (not shown). The controller 130 controls the power supply to the piezoelectric element 45 to selectively eject ink droplets from a plurality of nozzles 39. Also, a state sensor such as a liquid level sensor 95 is connected to the ASIC 135. The controller 130 performs the following image recording control, abnormality processing, etc. based on the signal received from the state sensor.

[0062] Also, an operation unit 17 is connected to the ASIC 135. The ASIC 135 receives a signal indicating that a button has been pressed from the operation unit 17. The ASIC 135 outputs display data indicating the content to be displayed on the display for the operation unit 17.

[0063] When recording an image on the paper 12, the controller 130 alternately executes a conveyance process and a printing process. The conveyance process is a process of conveying the paper 12 by a predetermined line feed amount by the conveyance roller pair 59 and the discharge roller pair 44. The controller 130 causes the conveyance roller pair 59 and the discharge roller pair 44 to execute the conveyance process by controlling the conveyance motor 101. The printing process is a process of controlling the power supply to the piezoelectric element 45 while moving the carriage 40 along the left - right direction 9 to eject ink droplets from the nozzles 39 to the head 38. During the printing process, the carriage 40 is located in the medium passage area 36 and faces the platen 42.

[0064] The controller 130 stops the paper 12 for a certain period between the current conveyance process and the next conveyance process. Then, the printing process is executed while the paper 12 is stopped. That is, in the printing process, the controller 130 executes one pass of discharging ink droplets from the nozzles 39 while moving the carriage 40 rightward or leftward. Thereby, image recording for one pass is executed on the paper 12. The controller 130 can perform image recording on the entire image-recordable area of the paper 12 by alternately and repeatedly executing the conveyance process and the printing process. That is, the controller 130 causes an image to be recorded on one sheet of paper 12 in a plurality of passes.

[0065] Note that the controller 130 is not limited to the above, and various processes may be performed only by the CPU 131, only by the ASIC 135, or by the CPU 131 and the ASIC 135 cooperating with each other. Also, the controller 130 may be configured such that one CPU 131 performs processing alone, or a plurality of CPU 131s perform processing in a shared manner. Further, the controller 130 may be configured such that one ASIC 135 performs processing alone, or a plurality of ASIC 135s perform processing in a shared manner.

[0066] [Image Recording Control by Controller 130] Hereinafter, the image recording control by the controller 130 will be described with reference to the flowchart shown in FIG. 7. Hereinafter, when the remaining amount of ink is small, it is referred to as near empty (denoted as NE in the drawing), and when there is no remaining amount of ink, it is referred to as empty. However, having no remaining amount of ink does not mean that the remaining amount of ink is exactly zero, but means that the remaining amount of ink is so small that normal printing cannot be performed.

[0067] In the image recording control shown in FIG. 7, the elapsed time since the previous printing, the first count value, the second count value, the near-empty flag, and the print stop flag are used. The controller 130 counts the first count value and the second count value and stores them in the memory 140. The first count value is reset to the initial value when the ink 99 is at the maximum amount (or when the user determines that the ink 99 has reached the maximum amount), and then counts up or down, and is a count value corresponding to the amount of decrease in the ink 99 stored in the storage unit 80. The second count value is reset to the initial value when it is determined that the ink 99 has become near-empty, and then counts up or down, and is a count value corresponding to the amount of decrease in the ink 99 stored in the storage unit 80.

[0068] The first count value and the second count value include the liquid volume of the ink discharged from the plurality of nozzles 39. The first count value and the second count value also include the liquid volume of the ink discharged from sources other than the plurality of nozzles 39. For example, the first count value and the second count value include the liquid volume of the ink discharged from the air release port when the exhaust purge is performed. When image recording is performed on one sheet of paper 12, the controller 130 obtains the amount of ink discharged from the plurality of nozzles 39 based on the print data, and adds the obtained amount to the first count value (and also to the second count value if necessary). When performing various maintenance operations, the controller 130 adds the amount of decrease in the ink 99 when each maintenance operation is performed to the first count value (and also to the second count value if necessary).

[0069] The near-empty flag (an example of a determination flag) is a flag that is OFF when the position in the vertical direction 7 of the liquid level of the ink 99 stored in the storage unit 80 is above the near-empty position, and is ON when the position in the vertical direction 7 of the liquid level of the ink 99 is at or below the near-empty position. The OFF state of the near-empty flag is an example of the first value of the determination flag. The ON state of the near-empty flag is an example of the second value of the determination flag. The print stop flag is a flag that is ON when printing (discharge of the ink 99 from a plurality of nozzles 39) is not executed, and is OFF when printing is executed. The print stop flag is ON when the ink 99 is empty, and is OFF when the ink 99 is not empty.

[0070] When image recording control is not being executed, the recording unit 24 and the cap 70 are in the state shown in FIG. 3. That is, the carriage 40 is located at the standby position, and the cap 70 is located at the covering position. When the controller 130 receives a print command (an example of a command), it performs the image recording control shown in FIG. 7. The print command is sent from the operation unit 17 (see FIG. 1) of the multifunction machine 10 or an external device connected to the multifunction machine 10 to the controller 130. The print command includes a command to start image recording control, information regarding the size of the paper 12, and print data to be image-recorded on the paper 12.

[0071] In the image recording control shown in FIG. 7, the controller 130 first determines whether the near-empty flag is ON (S110). Note that the near-empty flag is set to ON in S220 described later and is set to OFF in S270 described later. On the condition that the near-empty flag is ON in S110 (S110: ON), the controller 130 proceeds to S210.

[0072] On the condition that the near-empty flag is off in S110 (S110: OFF), the controller 130 acquires the elapsed time T since the previous printing (S120). To acquire the elapsed time T, the controller 130 has a clock, stores the end time of the previous printing obtained using the clock in the memory 140, and acquires the difference between the end time stored in the memory 140 and the execution time of S120 obtained using the clock as the elapsed time T. Alternatively, the controller 130 has a timer, starts the timer when printing ends, and in S120, acquires the time measured by the timer as the elapsed time T. Alternatively, the controller 130 communicates with an external device having a clock, stores the end time of the previous printing obtained using the external device's clock in the memory 140, and acquires the difference between the end time stored in the memory 140 and the execution time of S120 obtained using the external device's clock as the elapsed time T. The elapsed time T since the previous printing is an example of the elapsed time since the movement of the immediately preceding carriage 40 ended. Next, the controller 130 reads the threshold value Th_t related to the elapsed time T from the memory 140 (S130).

[0073] As shown in FIG. 8, the memory 140 stores a plurality of threshold values with different values. The threshold values are stored in, for example, the ROM 132 or the EEPROM 134. In the example shown in FIG. 8(A), the memory 140 stores a table storing (n + 1) threshold values Th_t0, Th_t1, etc. with different values according to the movement amount of the carriage 40. When the movement amount of the carriage 40 is large, foaming is likely to occur in the internal space 81 of the storage unit 80, and the generated bubbles tend to remain for a long time. On the other hand, when the movement amount of the carriage 40 is small, foaming is less likely to occur in the internal space 81 of the storage unit 80, and the generated bubbles tend to disappear in a short time. Therefore, the memory 140 stores threshold values that are larger as the movement amount of the carriage 40 is larger and smaller as the movement amount of the carriage 40 is smaller.

[0074] In this case, when the carriage 40 is moved in response to receiving a command (e.g., a printing command) by the controller 130, the controller 130 obtains the amount of movement of the carriage 40 and stores the obtained amount of movement in the memory 140. In S130, the controller 130 refers to the table shown in FIG. 8(A) based on the amount of movement of the carriage 40 immediately before, and selects one threshold value from a plurality of threshold values stored in the memory 140. The controller 130 uses the selected threshold value as the threshold value Th_t regarding the elapsed time T.

[0075] In the example shown in FIG. 8(B), the memory 140 stores a plurality of threshold values with different values according to the amount of movement of the carriage 40 and the type of the ink 99. In this example, the types of the ink 99 are type A, type B, and type C. The memory 140 stores a table storing (n + 1) threshold values Th_tA0, Th_tA1, etc. used when the type of the ink 99 is type A, (n + 1) threshold values Th_tB0, Th_tB1, etc. used when the type of the ink 99 is type B, and (n + 1) threshold values Th_tC0, Th_tC1, etc. used when the type of the ink 99 is type C. For example, when the viscosity of the ink is low, foaming is likely to occur in the internal space 81 of the storage unit 80, and the generated bubbles tend to remain for a long time. On the other hand, when the viscosity of the ink is high, foaming is unlikely to occur in the internal space 81 of the storage unit 80, and the generated bubbles tend to disappear in a short time. Therefore, the memory 140 stores threshold values that are larger as the viscosity of the ink is lower and smaller as the viscosity of the ink is higher.

[0076] In this case, the controller 130 stores the moving amount of the carriage 40 in the memory 140 in the same manner as described above, and acquires ink information (an example of liquid information) indicating the type of the ink 99 stored in the storage unit 80. The controller 130 acquires, for example, the ink information input using the operation unit 17. In S130, the controller 130 refers to the table shown in FIG. 8(B) based on the moving amount of the immediately preceding carriage 40 and the acquired ink information, and selects one threshold value from the plurality of threshold values stored in the memory 140. The controller 130 uses the selected threshold value as the threshold value Th_t regarding the elapsed time T.

[0077] Note that the memory 140 may store a plurality of threshold values having different values according to the type of the ink 99. In this case, the controller 130 acquires the ink information indicating the type of the ink 99 stored in the storage unit 80, and in S130, based on the acquired ink information, selects one threshold value from the plurality of threshold values stored in the memory 140, and may use the selected threshold value as the threshold value Th_t regarding the elapsed time T.

[0078] Next, the controller 130 determines whether or not the elapsed time T acquired in S120 exceeds the threshold value Th_t read in S130 (S140). On the condition that the elapsed time T exceeds the threshold value Th_t in S140 (S140: Yes), the controller 130 determines whether the liquid level sensor 95 is on (S150). In S150, the carriage 40 is still in a stopped state. The controller 130 proceeds to S310 on the condition that the liquid level sensor 95 is on (S150: ON). At this time, the ink 99 is near empty. The controller 130 proceeds to S210 on the condition that the liquid level sensor 95 is off (S150: OFF). At this time, the ink 99 is not near empty.

[0079] On the condition that the elapsed time T has not exceeded the threshold Th_t in S140 (S140: No), the controller 130 determines whether the first count value is greater than or equal to the threshold Th_c1 for the first count value (S160). The threshold Th_c1 is a threshold used to determine whether the ink 99 is near empty using the first count value. The controller 130 proceeds to S310 on the condition that the first count value is greater than or equal to the threshold Th_c1 (S160: Yes). At this time, the ink 99 is near empty. The controller 130 proceeds to S210 on the condition that the first count value is less than the threshold Th_c1 (S160: No). At this time, the ink 99 is not near empty.

[0080] Note that S150 is an example of a process of determining whether the liquid level of the ink 99 stored in the storage unit 80 is below a predetermined position based on the output signal of the liquid level sensor 95 before moving the carriage 40, which is executed on the condition that the acquired elapsed time T exceeds the threshold Th_t. S160 is an example of a process of determining whether the liquid level of the ink 99 stored in the storage unit 80 is below a predetermined position based on the first count value stored in the memory 140, which is executed on the condition that the acquired elapsed time T does not exceed the threshold Th_t.

[0081] When the liquid level sensor 95 is on in S150, or when the first count value is greater than or equal to the threshold Th_c1 in S160, the controller 130 notifies that the ink 99 is near empty (S210). In S210, the controller 130 executes a notification indicating that the remaining amount of ink is low at the operation unit 17. The controller 130 displays, for example, characters or symbols indicating that the remaining amount of ink is low on the operation unit 17.

[0082] Note that in S210, the controller 130 may perform notification indicating that the remaining amount of ink is low using elements other than the operation unit 17. For example, the controller 130 may perform notification indicating that the remaining amount of ink is low by turning on or flashing a lamp (not shown) provided outside the operation unit 17. S210 is an example of a process of performing notification indicating that the remaining amount of ink 99 in the operation unit 17 is low on the condition that it is determined that the liquid level of the ink 99 stored in the storage unit 80 is below a predetermined position.

[0083] Next, the controller 130 turns on the near empty flag and resets the second count value to the initial value (S220). The initial value of the second count value is, for example, 0. S220 is an example of a process of updating the determination flag from the first value to the second value, which is executed in response to determining that the liquid level of the ink 99 stored in the storage unit 80 is below a predetermined position.

[0084] Next, the controller 130 determines whether the second count value is equal to or greater than a threshold Th_c2 (an example of an empty threshold) related to the second count value (S230). Note that S230 is an example of a process of determining whether the second count value has reached the empty threshold. S230 is executed not only immediately after S220 but also after it is determined in S110 that the near empty flag is on. The controller 130 proceeds to S240 on the condition that the second count value is equal to or greater than the threshold Th_c2 (S230: Yes). At this time, the ink 99 is empty. The controller 130 proceeds to S210 on the condition that the second count value is less than the threshold Th_c2 (S230: No). At this time, the ink 99 is near empty.

[0085] On the condition that the second count value in S230 is equal to or greater than the threshold Th_c2, the controller 130 notifies that the ink 99 is empty (S240). In S240, the controller 130 executes a notification indicating that there is no remaining ink amount at the operation unit 17. The controller 130 displays, for example, characters or symbols indicating that there is no remaining ink amount on the operation unit 17.

[0086] Note that in S240, the controller 130 may execute a notification indicating that there is no remaining ink amount by using elements other than the operation unit 17. For example, the controller 130 may execute a notification indicating that there is no remaining ink amount by turning on or flashing a lamp (not shown) provided outside the operation unit 17.

[0087] Next, the controller 130 turns on the print stop flag (S250). While the print stop flag is on, the controller 130 does not execute the discharge of the ink 99. In S250, the controller 130 controls the carriage drive motor 103 to move the carriage 40 to the ink replenishment position. Note that the ink replenishment position may be the same as the standby position or different from the standby position. While the carriage 40 is at the ink replenishment position, the ink is replenished (S260). In S260, the lid 85 is removed from the protruding wall 84, and the ink 99 is injected into the internal space 81 from a bottle (not shown) through the injection port 83. The ink 99 is injected up to the maximum amount.

[0088] In S260, the controller 130 performs a process of confirming to the user that the ink 99 has been injected up to the maximum amount. For example, the controller 130 displays a message (e.g., "INK FULL?") for confirming that the ink has been injected up to the maximum amount on the operation unit 17, and when it is confirmed that a predetermined button has been pressed, S260 ends and the process proceeds to S270.

[0089] Next, the controller 130 turns off the near-empty flag and resets the first count value to its initial value (S270). The initial value of the first count value is, for example, 0. Next, the controller 130 proceeds to S310.

[0090] When the liquid level sensor 95 is off in S150, when the first count value is less than the threshold Th_c1 in S160, when the second count value is less than the threshold Th_c2 in S230, and immediately after S270, the controller 130 turns off the print stop flag (S310).

[0091] Next, the controller 130 performs flushing of the nozzles 39 and feeding of the paper 12 (S320). The flushing of the nozzles 39 is performed by the controller 130 controlling the piezoelectric element 45 after controlling the carriage drive motor 103 to move the carriage 40 to the standby position. The feeding of the paper 12 is performed by the controller 130 controlling the feed motor 102. The flushing of the nozzles 39 and the feeding of the paper 12 are executed in parallel.

[0092] When flushing is performed, ink 99 is discharged from the plurality of nozzles 39. The controller 130 adds the amount of ink 99 discharged from the plurality of nozzles 39 at this time to the first count value (and also to the second count value if necessary). Note that the amount of ink 99 discharged from the plurality of nozzles 39 when flushing is performed is determined in advance regardless of the print data.

[0093] Next, the controller 130 performs printing (image recording) on one sheet of paper 12 (S330). In S330, the controller 130 records an image in all image-recordable areas of the paper 12 by alternately repeating conveyance processing and printing processing. The controller 130 calculates the amount of ink discharged from the nozzles 39 when recording an image on one sheet of paper 12 based on the print data. The controller 130 adds the calculated amount of ink to the first count value (and also to the second count value if necessary).

[0094] Next, the controller 130 discharges the sheet 12 (S340). In S340, the controller 130 causes the transport roller pair 59 and the discharge roller pair 44 to transport the sheet 12 in the transport direction 15 and discharge it to the discharge tray 21.

[0095] Next, the controller 130 determines whether printing has ended (S350). In S350, the controller 130 determines whether all the image data included in the print command has been recorded on the sheet 12.

[0096] On the condition that it is determined in S350 that printing has not ended (S350: No), the controller 130 feeds the sheet 12 (S360). The process of S360 is the same as the feeding in S320. Thereafter, the controller 130 proceeds to S330. Note that the subsequent feeding of the sheet 12 may be executed in parallel with the discharge of the preceding sheet 12 (S340).

[0097] On the condition that it is determined in S350 that printing has ended (S350: Yes), the controller 130 moves the carriage 40 to the standby position (S370). With the above, the controller 130 ends the image recording control.

[0098] In S320, S330, and S370, the controller 130 moves the carriage 40 in the left - right direction 9. In S120, as a process of obtaining the elapsed time since the end of the previous movement of the carriage 40, the controller 130 obtains the elapsed time T since the previous printing. The movement of the carriage 40 and the acquisition of the elapsed time T are performed in response to receiving a print command.

[0099] Further, on the condition that the near-empty flag is on (S110: ON), the controller 130 does not execute the determination (S150 and S160) as to whether the liquid level of the ink 99 stored in the storage unit 80 is below the near-empty position, and counts the second count value and stores it in the memory 140 in S320, S330, and S370.

[0100] In the multifunction machine 10, the movement of the carriage 40 in the left-right direction 9 includes executing image recording in which ink is ejected from a plurality of nozzles 39 while moving the carriage 40 in the left-right direction 9. In addition to this, the movement of the carriage 40 in the left-right direction 9 includes executing various maintenance operations. In the image recording control shown in FIG. 7, the timing before moving the carriage 40 is before starting image recording and also before ejecting ink from a plurality of nozzles 39 for image recording.

[0101] The controller 130 also moves the carriage 40 in the left-right direction 9 when receiving a command other than a print command. In order to keep the plurality of nozzles 39 of the head 38 in a preferable state, the controller 130 performs maintenance operations such as flushing, wiping, suction purge, and exhaust purge. The controller 130 performs a maintenance operation when receiving a corresponding command. When a maintenance operation is performed, the ink 99 stored in the storage unit 80 is discharged from the plurality of nozzles 39 of the head 38 or elements other than the nozzles 39. Each time a maintenance operation is performed, the controller 130 adds the amount of ink discharged from the plurality of nozzles 39 of the head 38 or elements other than the nozzles 39 to the first count value (and also to the second count value if necessary).

[0102] [Advantages of the Embodiment] According to this embodiment, when the elapsed time T has passed the threshold Th_t, the controller 130 determines the liquid level of the ink 99 stored in the storage unit 80 based on the signal output by the liquid level sensor 95 before moving the carriage 40. Thereby, it is possible to determine the liquid level based on the output of the liquid level sensor 95 in a state where foaming of the ink does not occur in the storage unit 80.

[0103] When the elapsed time T has not passed the threshold Th_t, the controller 130 determines the liquid level of the ink 99 stored in the storage unit 80 based on the first count value. Thereby, it is possible to determine the liquid level without depending on the output of the liquid level sensor 95 in a state where foaming of the ink 99 occurs in the storage unit 80.

[0104] Further, when the controller 130 selects one threshold from a plurality of thresholds regarding the elapsed time T based on the movement amount of the carriage 40, the larger the movement amount of the carriage 40, the more likely foaming occurs in the storage unit 80. Therefore, a threshold corresponding to the time required for the foaming to disappear in the storage unit 80 can be selected.

[0105] Further, when the controller 130 selects one threshold from a plurality of thresholds regarding the elapsed time T based on the ink information, the likelihood of foaming in the storage unit 80 varies depending on the type of the ink 99. Therefore, a threshold corresponding to the time required for the foaming to disappear in the storage unit 80 can be selected.

[0106] Further, according to this embodiment, the controller 130 does not execute the discharge of the ink 99 from the plurality of nozzles 39 on the condition that the second count value has reached the threshold Th_c2. Therefore, the entry of air from the storage unit 80 into the nozzles 39 is suppressed.

[0107] Further, according to this embodiment, the controller 130 executes error notification on the operation unit 17 on the condition that the second count value has reached the threshold Th_c2. Therefore, based on the error notification, the user can recognize that the discharge of the ink 99 from the nozzles 39 has been stopped.

[0108] [Modification Example] In the above embodiment, the liquid level of the ink 99 stored in the storage unit 80 is detected using the rotating member 90 provided with the float 91 and the liquid level sensor 95. However, as shown in FIG. 9, the liquid level of the ink 99 stored in the storage unit 80 may be detected using the prism 96 and the liquid level sensor 95. In the example shown in FIG. 9, the prism 96 is provided in the internal space 81 of the storage unit 80. The liquid level sensor 95 includes a light emitting unit 95A and a light receiving unit 95B.

[0109] When the height of the liquid level of the ink 99 stored in the storage unit 80 is above the near empty position in the vertical direction 7, the light emitted from the light emitting unit 95A propagates along the arrow 97 shown in FIG. 9, is reflected twice by the prism 96, and enters the light receiving unit 95B. When the height of the liquid level of the ink 99 stored in the storage unit 80 is below the near empty position in the vertical direction 7, the amount of light reflected by the prism 96 decreases, and the amount of light entering the light receiving unit 95B decreases. Therefore, the liquid level of the ink 99 stored in the storage unit 80 can be detected using the prism 96 and the liquid level sensor 95.

[0110] In the above embodiment, only one storage unit 80 was provided, but a plurality of storage units 80 may be provided. For example, as shown in FIG. 10, the recording unit 24 may include four storage units 80C, 80M, 80Y, and 80B. Cyan ink is stored in the storage unit 80C. Magenta ink is stored in the storage unit 80M. Yellow ink is stored in the storage unit 80Y. Black ink is stored in the storage unit 80B. The storage units 80C, 80M, 80Y, and 80B are arranged side by side in the front-rear direction 8. Note that the storage units 80C, 80M, 80Y, and 80B may be arranged side by side in a direction other than the front-rear direction 8, for example, the left-right direction 9. Also, the arrangement order of the storage units 80C, 80M, 80Y, and 80B is not limited to the order shown in FIG. 10. Also, the sizes of the respective storage units 80C, 80M, 80Y, and 80B may be the same or different.

[0111] In the above-described embodiment, the storage unit 80 is installed on the carriage 40, and the ink is replenished by injecting ink from the injection port 83. However, the storage unit 80 is not limited to such a configuration. For example, the storage unit 80 may be a cartridge that is detachable from the carriage 40. In this case, when the ink stored in the cartridge runs low or runs out, it is replaced with a new cartridge.

[0112] In the above-described embodiment, the multifunction machine 10 is not provided with a valve unit that communicates the portion filled with air (hereinafter referred to as the gas layer) in the internal space 81 of the storage unit 80 with the outside. However, the multifunction machine 10 may include a gas flow path that communicates the gas layer of the storage unit 80 with the outside through an air release port that opens to the outside, and a valve unit that opens or closes the air release port or the gas flow path.

Explanation of Reference Numerals

[0113] 10... Multifunction machine (image recording apparatus) 12... Paper (recording medium) 17... Operation unit (notification unit) 38... Head 39... Nozzle 40... Carriage 80... Storage unit 95... Liquid level sensor (sensor) 99... Ink (liquid) 130... Controller 140... Memory

Claims

1. A carriage movable in a first direction, A head mounted on the carriage and having a plurality of nozzles for discharging liquid, A storage unit mounted on the carriage for supplying the stored liquid to the head, A sensor for detecting the liquid level of the liquid stored in the storage unit, A transport mechanism for transporting a recording medium in a second direction intersecting the first direction, An informing unit, A memory storing a plurality of threshold values with different values, A controller, and is provided with, The controller, Counts a first count value corresponding to the decrease amount of the liquid stored in the storage unit, including the liquid amount discharged from the plurality of nozzles, and stores it in the memory, Moves the carriage in the first direction in response to receiving a command, Acquires the elapsed time since the previous movement of the carriage ended in response to receiving a command, Stores the movement amount of the carriage by the command in the memory, Selects one threshold value from the plurality of threshold values based on the previous movement amount of the carriage, On the condition that the acquired elapsed time exceeds the selected threshold value, determines whether the liquid level of the liquid stored in the storage unit is below a predetermined position based on the signal output by the sensor before moving the carriage, On the condition that the acquired elapsed time does not exceed the selected threshold value, determines whether the liquid level of the liquid stored in the storage unit is below a predetermined position based on the first count value stored in the memory, An image recording apparatus that executes an alarm indicating that the remaining amount of liquid is low in the alarm unit on the condition that it is determined that the liquid level of the liquid stored in the storage unit is below a predetermined position.

2. The controller, Acquires liquid information indicating the type of liquid stored in the storage unit, The image recording apparatus according to claim 1, wherein the one threshold value is selected from the plurality of threshold values based on the previous movement amount of the carriage and the acquired liquid information.

3. The memory stores the value of a determination flag and an empty threshold value, The controller, Updates the determination flag from a first value to a second value in response to determining that the liquid level of the liquid stored in the storage unit is below a predetermined position, On the condition that the determination flag is the second value, without determining whether the liquid level of the liquid stored in the storage unit is below a predetermined position, a second count value corresponding to the decrease amount of the liquid stored in the storage unit, including the liquid amount discharged from the plurality of nozzles, is counted and stored in the memory. The image recording apparatus according to claim 1 or 2, wherein the discharge of the liquid from the plurality of nozzles is not executed on the condition that the second count value reaches the empty threshold value.

4. The image recording apparatus according to claim 3, wherein the controller executes error notification in the notification unit on the condition that the second count value reaches the empty threshold value.

5. The controller In response to receiving the command, as the movement of the carriage in the first direction, image recording is executed in which the carriage moves in the first direction and liquid is discharged from the plurality of nozzles. In response to receiving the command, as the elapsed time since the end of the previous movement of the carriage, the elapsed time since the end of the previous image recording is acquired. The image recording apparatus according to any one of claims 1 to 4, wherein on the condition that the acquired elapsed time exceeds the selected threshold value, as the timing before moving the carriage, it is determined whether the liquid level of the liquid stored in the storage unit is below a predetermined position based on the signal output by the sensor before starting the image recording.

6. The controller The image recording apparatus according to claim 5, wherein on the condition that the acquired elapsed time exceeds the selected threshold value, as the timing before starting the image recording, it is determined whether the liquid level of the liquid stored in the storage unit is below a predetermined position based on the signal output by the sensor before discharging the liquid from the plurality of nozzles for the image recording.

Images