Liquid cartridge

Abstract

The liquid cartridge includes: a housing; a circuit board including electrodes; and a liquid supply portion extending from the housing in the depth direction. The housing includes a top wall and first and second protrusions protruding upward from the top wall. Relative to the circuit board, the first protrusion is located at the rear, while the second protrusion is located at the front. The first protrusion is higher than the upper edge of the front end of the second protrusion. In a region between a first point on the first protrusion and a second point on the second protrusion, i.e., the upper edge of the front end of the second protrusion, in the depth direction, no part of the liquid cartridge is positioned higher than a hypothetical plane in the height direction. The hypothetical plane passes through the first and second points and extends perpendicular to the depth direction. Compared with a configuration without the second protrusion, when the dropped liquid cartridge collides with a flat surface or the floor, the change in the attitude of the housing is smaller. Therefore, it is less likely that ink splashes through the opening of the liquid supply portion.

Description

Technical Field

[0001] The present disclosure relates to a liquid cartridge including: a housing having a liquid chamber therein; and a liquid supply unit configured to supply liquid stored in the liquid chamber to the outside of the liquid chamber. Background Art

[0002] A printer is known which includes a recording head configured to eject ink supplied from an ink cartridge through nozzles (for example, see Japanese Patent Application Laid-Open No. 2019-64046). In such a printer, once the ink in the liquid cartridge runs out, a new ink cartridge is to be installed. The ink cartridge includes a housing and a light shielding plate, and an ink chamber is provided in the housing. The light shielding plate is provided at the top surface of the housing and is configured to block or attenuate light emitted in the left-right direction.

[0003] In the case where the ink cartridge drops onto a flat surface such as a floor and collides with the flat surface, the attitude of the ink cartridge may change while multiple portions of the ink cartridge successively collide with the flat surface. Such a change in the attitude of the ink cartridge may cause the ink adhering to the ink supply portion to spread and may result in contamination of the floor. Summary of the Invention

[0004] In view of the foregoing, an object of the present disclosure is to provide a liquid cartridge that is less likely to change its attitude when colliding with a flat surface.

[0005] (1)According to one aspect, the present disclosure provides a liquid cartridge including a housing, a circuit board, and a liquid supply unit. A liquid storage chamber is defined in the housing. The circuit board includes electrodes. The liquid supply unit extends from the housing in a depth direction intersecting with the direction of gravity, and the liquid supply unit has an opening facing forward in the depth direction. A liquid passage is defined in the liquid supply unit, and the liquid passage connects the liquid storage chamber to the opening, and the liquid passage is configured to allow the liquid in the liquid storage chamber to flow out of the housing through the opening. The housing includes: a top wall where the circuit board is disposed; a first protrusion protruding upward from the top wall; and a second protrusion protruding upward from the top wall. In an upright posture of the liquid cartridge, the top wall faces upward and is located above the liquid supply unit. The first protrusion is located behind the circuit board in the depth direction. The second protrusion is located in front of the circuit board in the depth direction, and the second protrusion extends in the depth direction, and the second protrusion has a front end facing forward in the depth direction. In the upright posture of the liquid cartridge, the first protrusion is positioned higher than the upper edge of the front end of the second protrusion. The front end of the second protrusion is located in front of the opening of the liquid supply unit in the depth direction. In the upright posture of the liquid cartridge, in a region between a first point on the first protrusion and a second point on the second protrusion in the depth direction, no part of the liquid cartridge is positioned higher than a hypothetical plane in a height direction opposite to the direction of gravity, the second point being the upper edge of the front end of the second protrusion, the hypothetical plane passing through each of the first point and the second point, and the hypothetical plane extending in a width direction perpendicular to the depth direction and the direction of gravity. The first protrusion and the second protrusion are located below the hypothetical plane.

[0006] In this structure, any outer surface of the liquid cartridge is located below the hypothetical plane in a region between a first point on the first protrusion and a second point (the upper edge of the front end of the second protrusion) in the depth direction. Therefore, when the liquid cartridge drops onto a flat surface such as a floor, the first protrusion first collides with the flat surface, and then the upper edge of the front end of the second protrusion collides with the flat surface or the floor. Compared with a configuration without the second protrusion, when the dropped liquid cartridge collides with the flat surface or the floor, the change in the posture of the housing is smaller. Therefore, it is less likely that ink splashes through the opening of the liquid supply unit.

[0007] (2)Preferably, in the above liquid cartridge according to aspect (1), the top wall has a front end facing forward in the depth direction, and in the upright posture of the liquid cartridge, the front end is located below the hypothetical plane.

[0008] In the case of this structure, since the front end of the top wall is located below the imaginary plane, when the liquid cartridge drops onto a flat surface or the floor, the front end of the top wall is less likely to be damaged.

[0009] (3) Preferably, in the above liquid cartridge according to aspect (1) or (2), the first protrusion has an upper surface, and the upper surface includes the first point; and the housing defines a center point of the housing in the depth direction; the upper surface of the first protrusion is located behind the center point of the housing in the depth direction; and the upper edge of the front end of the second protrusion is located in front of the center point of the housing in the depth direction.

[0010] (4) Preferably, in the above liquid cartridge according to any one of aspects (1) to (3), the top wall directly or indirectly supports the circuit board.

[0011] (5) Preferably, in the above liquid cartridge according to any one of aspects (1) to (4), the first protrusion includes a first protruding portion, a second protruding portion, and a third protruding portion. The first protruding portion extends in the depth direction, and the first protruding portion has a rear end facing backward in the depth direction. The second protruding portion extends in the depth direction, and the second protruding portion is positioned to be spaced apart from the first protruding portion in the width direction, and the second protruding portion has a rear end facing backward in the depth direction. The third protruding portion extends in the width direction, and the third protruding portion connects the rear end of the first protruding portion to the rear end of the second protruding portion. Preferably, the size of the second protrusion in the depth direction is greater than the size of the second protrusion in the gravity direction and the size of the second protrusion in the width direction.

[0012] In the case of this structure, since the size of the second protrusion in the depth direction is greater than the size of the second protrusion in the gravity direction and the width direction, even when the second protrusion contacts a flat surface such as the floor due to the liquid cartridge dropping onto the floor, the second protrusion is hardly damaged. In addition, since the first protrusion is composed of the first protruding portion and the second protruding portion connected to each other by the third protruding portion, the first protrusion has a higher impact resistance than the second protrusion.

[0013] (6) Preferably, in the above liquid cartridge according to aspect (6), the third protruding portion has a joint surface facing backward in the depth direction, and the joint surface is used to be joined to a part of the cartridge case in a state where the liquid cartridge is attached to the cartridge case.

[0014] In the case of this structure, the rear-facing surface of the first protrusion can be used to position the liquid cartridge in the cartridge housing without providing a separate engagement member on the liquid cartridge.

[0015] (7) Preferably, in the above-mentioned liquid cartridge according to any one of aspects (1) to (6), the top wall of the housing has: a first portion that extends in the depth direction; and a second portion that is inclined with respect to the depth direction so as to extend downward and forward from the first portion in the upright posture of the liquid cartridge. The first portion and the second portion define a boundary therebetween. The front end of the second protrusion is located on the second portion. The second protrusion extends across the boundary between the first portion and the second portion.

[0016] In the case of this structure, the inclined second portion is located in front of the first portion in the depth direction. Therefore, even when the liquid cartridge drops onto a flat surface such as the floor, the inclined second portion is less likely to collide with the floor. In addition, since the second protrusion is positioned to extend across the boundary between the first portion and the second portion, the boundary can be strengthened by the second protrusion.

[0017] (8) Preferably, in the above-mentioned liquid cartridge according to aspect (8), in the upright posture of the liquid cartridge, the boundary is located below the imaginary plane.

[0018] In the case of this structure, even when the liquid cartridge drops onto a flat surface such as the floor, it is possible to avoid the collision of the boundary of the top wall with the floor. Therefore, deformation of the top wall near the boundary can be suppressed.

[0019] (9) Preferably, in the above-mentioned liquid cartridge according to any one of aspects (1) to (8), in the upright posture of the liquid cartridge, the entire circuit board is located below the imaginary plane.

[0020] In the case of this structure, since the circuit board as a whole is located below the imaginary plane, the circuit board is less likely to be damaged when the liquid cartridge drops onto a flat surface or the floor.

[0021] (10) Preferably, in the above-mentioned liquid cartridge according to any one of aspects (1) to (9), the housing includes a base and a lid. The liquid storage chamber is defined in the base, and the base has an upper end that opens upward in the upright posture of the liquid cartridge. The lid is engaged with the base to cover the upper end of the base. The lid includes the top wall, and the lid directly or indirectly supports the circuit board.

[0022] (11) Preferably, in the above liquid cartridge according to aspect (10), the base includes a plurality of engaging claws for engaging with the lid; the lid further includes a peripheral wall extending downward from the periphery of the top wall, the peripheral wall being formed with a plurality of engaging holes, each engaging hole receiving a corresponding one of the engaging claws; and the front end of the second protrusion is positioned to be further forward in the depth direction than any one of the engaging holes engaged with the corresponding engaging claw.

[0023] In this structure, the front end of the second protrusion, which is prone to be applied with an external force, is positioned to be further forward in the depth direction than any one of the engaging claws. Therefore, the external force applied to the second protrusion is less likely to be transmitted to the engaging claws.

[0024] (12) Preferably, in the above liquid cartridge according to aspect (11), the second protrusion has a rear end opposite to the front end in the depth direction; and the rear end of the second protrusion is positioned to be further backward than the one engaging hole located most forward in the depth direction among the plurality of engaging holes.

[0025] In this structure, since the second protrusion extends in the depth direction to have a sufficient length to span the entire size of the engaging hole located most forward in the depth direction, the lid is further strengthened.

[0026] (13) Preferably, in the above liquid cartridge according to any one of aspects (1) to (9), the housing further includes a peripheral wall extending downward from the periphery of the top wall. The peripheral wall includes: a front wall facing forward in the depth direction; a first side wall extending from the front wall in the depth direction; and a second side wall extending from the front wall in the depth direction, and the second side wall is spaced apart from the first side wall in the width direction. Preferably, the front end of the second protrusion is positioned to be spaced apart from the front wall in the depth direction and spaced apart from each of the first side wall and the second side wall in the width direction.

[0027] In this structure, since the front end of the second protrusion is spaced apart from each of the front wall, the first side wall, and the second side wall, the external impact applied to the front wall and the first side wall and the second side wall is less likely to be transmitted to the second protrusion. Therefore, the possibility of the second protrusion being deformed due to the impact is reduced.

[0028] (14) Preferably, in the above liquid cartridge according to any one of aspects (1) to (13), the first protrusion includes: an inclined surface that is inclined with respect to the depth direction; and a horizontal surface that is connected to the inclined surface, and the horizontal surface is located behind the inclined surface in the depth direction. In the upright posture, the horizontal surface extends in the depth direction. The first point is on the boundary between the inclined surface and the horizontal surface.

[0029] (15) Preferably, in the above liquid cartridge according to any one of aspects (1) to (14), the second protrusion is plate-shaped, and the second protrusion has a front surface, a main upper surface, and a sub-upper surface. The front surface extends from the top wall, and the front surface faces forward in the depth direction. The front end of the second protrusion has the front surface. The main upper surface extends in the depth direction, and in the upright posture of the liquid cartridge, the main upper surface faces upward. The sub-upper surface extends from the main upper surface, and the sub-upper surface is inclined with respect to the depth direction such that in the upright posture of the liquid cartridge, the sub-upper surface is inclined downward and forward. The upper edge of the front end of the second protrusion is defined by the front surface and the sub-upper surface.

[0030] In this case of such a structure, since the second protrusion is a plate-like shape elongated in the depth direction (for example, in the form of a wall), it is difficult for the second protrusion to interfere with the components of the cartridge housing during attachment of the liquid cartridge to the cartridge housing.

[0031] (16) Preferably, in the above liquid cartridge according to any one of aspects (1) to (15), the electrode has a front edge that faces forward in the depth direction; and the front edge is located behind the center point of the region in the depth direction.

[0032] In this case of such a structure, since the front edge of the electrode is positioned further backward than the center point of the region in the depth direction, even when the liquid cartridge drops onto a flat surface such as a floor, a gap (clearance) can be reliably ensured vertically between the imaginary plane and the circuit board (electrical contact member). Therefore, in the case where the dropped liquid cartridge collides with the flat surface, the impact hardly causes any loss of the functions of the circuit board.

[0033] (17) Preferably, in the above liquid cartridge according to any one of aspects (1) to (16), the housing has a support portion that supports the circuit board, and the support portion is detachably attached to the housing.

[0034] (18)According to another aspect, the present disclosure provides a cartridge set constituted by a plurality of liquid cartridges according to any one of aspects (1) to (17). The plurality of liquid cartridges are configured to be accommodated in different spaces from each other in a cartridge housing, and the second protrusions of the plurality of liquid cartridges are at different positions in the width direction from each other.

[0035] In the case of such a structure, the position of the second protrusion in the width direction can vary according to the type of the liquid cartridge (e.g., the type and initial amount of ink stored in the liquid cartridge). Therefore, the user can visually confirm the position of the second protrusion to identify the type of the liquid cartridge.

[0036] (19)According to still another aspect, the present disclosure provides a liquid cartridge including a housing, a circuit board, and a liquid supply unit. A liquid storage chamber is defined in the housing. The housing includes a plurality of walls that define the outline of the liquid cartridge when viewed in a width direction intersecting with the direction of gravity. The plurality of walls include: a pair of side walls; a front wall and a rear wall; and a top wall and a bottom wall. The pair of side walls are spaced apart from each other in the width direction. The front wall and the rear wall are spaced apart from each other in a depth direction perpendicular to the width direction. The top wall and the bottom wall are spaced apart from each other in a height direction perpendicular to the width direction and the depth direction. The circuit board includes electrodes. The liquid supply unit is provided at the housing and has a liquid passage extending in the depth direction from the liquid storage chamber. The housing further includes: a first protrusion that protrudes upward from the top wall and is located behind the circuit board in the depth direction; and a second protrusion that protrudes upward from the top wall and is located in front of the circuit board in the depth direction. The second protrusion extends in the depth direction and has a front end facing forward in the depth direction. The first protrusion is positioned higher than the upper edge of the front end of the second protrusion. The front end of the second protrusion is located in front of the opening of the liquid supply unit in the depth direction. When viewed in the width direction, in the entire region between a first point on the first protrusion and a second point on the second protrusion in the depth direction, the outline of the liquid cartridge is positioned lower in the height direction than a hypothetical line, the second point is the upper edge of the front end of the second protrusion, and the hypothetical line passes through each of the first point of the first protrusion and the second point of the second protrusion. The first protrusion and the second protrusion are located below the hypothetical line.

[0037] In the case of such a structure, the same technical and operational advantages as those of the liquid cartridge according to aspect (1) can be obtained.

[0038] The features of the above aspects (2) to (17) can be appropriately combined with the liquid cartridge according to aspect (19). As a result of the combination, the resulting liquid cartridge can obtain the same technical and operational advantages as those of the liquid cartridge according to aspect (1) in combination with the features of the above aspects (2) to (17). BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The specific features and advantages of the embodiments, as well as other objects, will become apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0040] Figure 1 is a vertical sectional view schematically showing the internal structure of a printer 10 according to an embodiment of the present disclosure;

[0041] Figure 2 is a horizontal sectional view of a cartridge attachment portion 110 of the printer 10 according to the embodiment;

[0042] Figure 3 is a vertical sectional view showing a state in which an ink cartridge 30 is attached to the cartridge attachment portion 110;

[0043] Figure 4 is a rear perspective view of the ink cartridge 30;

[0044] Figure 5 is a side view of the ink cartridge 30;

[0045] Figure 6 is a side view showing a state in which the upside-down ink cartridge 30 collides with the floor 160 with the horizontal surface 154 of the protrusion 43;

[0046] Figure 7 is a side view showing a state in which the upside-down ink cartridge 30 collides with the floor 160 with the upper edge 67FU of the boundary 156 of the protrusion 43 and the front end 67F of the rib 67;

[0047] Figure 8 is a rear perspective view of the ink cartridge 30 having ribs 67 at different left and right positions; and

[0048] Figure 9 is a partial perspective view showing a structure for supporting an IC substrate 64 according to a variant of the embodiment. DETAILED DESCRIPTION

[0049] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It will be apparent to those skilled in the art that the following embodiments are merely examples of the present disclosure, and modifications and variations can be made therein without departing from the scope of the present disclosure.

[0050] In the following description, the forward direction 51 is defined as the direction in which the ink cartridge 30 is inserted into the cartridge attachment portion 110. The backward direction 52 is defined as the direction in which the ink cartridge 30 is withdrawn from the cartridge attachment portion 110.

[0051] In the following example, the ink cartridge 30 is horizontally inserted into and withdrawn from the cartridge attachment portion 110. Therefore, the description will be made assuming that the forward direction 51 and the backward direction 52 are horizontal, but the forward direction 51 and the backward direction 52 may not be horizontal. In addition, the downward direction 53 is defined as the direction perpendicular to the forward direction 51 or the backward direction 52. The upward direction 54 is defined as the direction opposite to the downward direction 53. In addition, the rightward direction 55 is defined as the direction perpendicular to the forward direction 51 and the downward direction 53. The leftward direction 56 is defined as the direction opposite to the rightward direction 55. Therefore, in the state where the ink cartridge 30 is attached to the cartridge attachment portion 110 and used together with the cartridge attachment portion 110, the downward direction 53 coincides with the direction of gravity, and the upward direction 54 is opposite to the direction of gravity. That is, in the state where the ink cartridge 30 is attached to the cartridge attachment portion 110 and used together with the cartridge attachment portion 110, the outer surface of the main bottom wall 42 of the housing 130 faces downward in the direction of gravity.

[0052] In addition, the rightward direction 55 and the leftward direction 56 are defined as the directions perpendicular to the forward direction 51 and the downward direction 53. More specifically, in the state where the ink cartridge 30 is attached to the cartridge attachment portion 110 and used together with the cartridge attachment portion 110, when the ink cartridge 30 is viewed from the rear side of the ink cartridge 30, the rightward direction 55 is the direction toward the right, and the leftward direction 56 is the direction toward the left.

[0053] Note that the state where the ink cartridge 30 is attached to the cartridge attachment portion 110 and used together with the cartridge attachment portion 110 means the state where the ink cartridge 30 has been completely inserted into the attachment position in the cartridge attachment portion 110. At the attachment position of the ink cartridge 30, the ink supply tube 102 of the cartridge attachment portion 110 is inserted into and connected to the ink supply portion 34 of the ink cartridge 30. In addition, hereinafter, the attitude of the ink cartridge 30 in the state where the ink cartridge 30 is attached to the cartridge attachment portion 110 and thus used will be referred to as the "operable attitude".

[0054] In addition, in the following description, the forward direction 51 and the backward direction 52 may be collectively referred to as the front-back direction. The upward direction 54 and the downward direction 53 may be collectively referred to as the up-down direction. The rightward direction 55 and the leftward direction 56 may be collectively referred to as the left-right direction.

[0055] In the following description, "facing forward" includes facing a direction including a forward component, and "facing backward" includes facing a direction including a backward component. In addition, "facing downward" includes facing a direction including a downward component, and "facing upward" includes facing a direction including an upward component. For example, "the front surface faces forward" means that the front surface may face the forward direction, or the front surface may face a direction inclined with respect to the forward direction.

[0056] [Overview of the printer 10]

[0057] As Figure 1 shown, the printer 10 is an image recording device configured to record an image by selectively ejecting ink droplets onto a sheet based on an inkjet recording system. For example, the printer 10 is an inkjet printer. The printer 10 includes a recording head 21, an ink supply device 100, and an ink tube 20 that connects the recording head 21 to the ink supply device 100. The ink supply device 100 includes a cartridge attachment portion 110. An ink cartridge 30 can be attached to the cartridge attachment portion 110. The cartridge attachment portion 110 has a surface formed with an opening 112. The ink cartridge 30 is inserted forward into the cartridge attachment portion 110 through the opening 112, and the ink cartridge 30 is withdrawn backward from the cartridge attachment portion 110 through the opening 112.

[0058] The ink cartridge 30 stores ink therein. For example, the ink cartridge 30 stores ink that the printer 10 can use for printing. In a state where the ink cartridge 30 has been fully attached to the cartridge attachment portion 110, the ink cartridge 30 and the recording head 21 are connected to each other through the ink tube 20. The recording head 21 includes a damping chamber 28 that temporarily stores the ink supplied through the ink tube 20. The recording head 21 is configured to eject the ink supplied from the damping chamber 28 through a plurality of nozzles 29. More specifically, a head control board provided in the recording head 21 is configured to selectively apply a driving voltage to piezoelectric elements provided corresponding to the plurality of nozzles 29. Therefore, the ink can be selectively ejected through the nozzles 29. That is, the recording head 21 is configured to consume the ink stored in the ink cartridge 30 attached to the cartridge attachment portion 110.

[0059] The printer 10 includes a sheet tray 15, a sheet feed roller 23, a pair of conveyance rollers 25, a platen 26, a pair of discharge rollers 27, and a sheet discharge tray 16. The sheet feed roller 23 is configured to convey the sheet in the sheet tray 15 toward a conveyance path 24. The sheet conveyed onto the conveyance path 24 reaches the pair of conveyance rollers 25. The pair of conveyance rollers 25 is configured to convey the reached sheet onto the platen 26. The recording head 21 is configured to selectively eject ink onto the sheet moving on the platen 26, thereby recording an image on the sheet. The sheet that has passed through the platen 26 then reaches the pair of discharge rollers 27. The pair of discharge rollers 27 is configured to discharge the reached sheet onto the sheet discharge tray 16 provided at the downstream end of the conveyance path 24.

[0060] [Ink Supply Device 100]

[0061] As Figure 1 shown, the printer 10 includes an ink supply device 100. The ink supply device 100 is configured to supply ink to the recording head 21. As described above, the ink supply device 100 includes a cartridge attachment portion 110 to which the ink cartridge 30 can be attached. Incidentally, Figure 1 a state where the attachment of the ink cartridge 30 to the cartridge attachment portion 110 is completed is depicted. In other words, inFigure 1 In this case, the ink cartridge 30 is in an attached state. The posture of the ink cartridge 30 in this state is an operable posture.

[0062] [Cartridge attachment portion 110]

[0063] As Figures 1 to 3 shown, the ink supply device 100 includes a cartridge case 101 and an ink supply tube 102. In the cartridge attachment portion 110, four ink cartridges 30 corresponding to the respective colors of cyan, magenta, yellow, and black can be accommodated. In addition, four ink supply tubes in the ink supply tube 102 are provided corresponding to these four ink cartridges 30.

[0064] [Cartridge case 101]

[0065] As Figure 2 depicted, the cartridge case 101 constitutes the housing of the cartridge attachment portion 110. The cartridge case 101 is in the shape of a box and has a top surface 57, a bottom surface, a right side surface 107, a left side surface 108, an end surface 59, and an opening 112. The top surface 57 defines a top plate that is the upper end of the internal space of the cartridge case 101. The bottom surface defines a bottom that is the lower end of the internal space of the cartridge case 101. The right side surface 107 defines the right edge of the internal space of the cartridge case 101. The left side surface 108 defines the left edge of the internal space of the cartridge case 101. The end wall 59 is connected to the top surface 57, the bottom surface, the right side surface 107, and the left side surface 108. The opening 112 is formed to face the end surface 59 in the front-rear direction in the cartridge case 101. The opening 112 can be exposed to a user interface surface, which is a surface that a user can face when using the printer 10.

[0066] The ink cartridge 30 can be inserted into the cartridge case 101 through the opening 112 and can be removed from the cartridge case 101 through the opening 112. In the bottom of the cartridge case 101, a guide groove 109 is formed. By inserting the lower end of the ink cartridge 30 into the guide groove 109, the ink cartridge 30 is guided by the guide groove 109 in the front-rear direction (the direction orthogonal to the sheet surface of Figure 2 ). The cartridge case 101 also includes three plates 104 that divide the internal space into four different spaces elongated in the up-down direction. In each of the four spaces divided by the plates 104, one ink cartridge 30 is accommodated.

[0067] [Ink supply tube 102]

[0068] As Figure 2 and Figure 3As shown, the ink supply tube 102 has a hollow cylindrical shape and is provided at the lower end of the end surface 59 of the cartridge case 101. The ink supply tube 102 is provided at a position corresponding to the ink supply portion 34 of the ink cartridge 30 attached to the cartridge attachment portion 110. The ink supply tube 102 projects rearward from the end surface 59 of the cartridge case 101 and has a rear end that opens rearward (opening 116).

[0069] In the internal space of the ink supply tube 102, a tube valve 114 and a helical spring 115 are accommodated. In the internal space of the ink supply tube 102, the tube valve 114 can move in the forward direction 51 and the backward direction 52 between an open position for opening the opening 116 and a closed position for closing the opening 116. The helical spring 115 presses the tube valve 114 in the direction for moving the tube valve 114 toward the closed position (i.e., in the backward direction 52). At the closed position, the end (rear end) of the tube valve 114 projects further in the backward direction 52 than the opening 116.

[0070] [Locking shaft 145]

[0071] As Figure 3 shown, the locking shaft 145 is provided at the cartridge case 101 and at a position near the top surface 57 and the opening 112 so as to extend in the left - right direction. The locking shaft 145 is a rod - shaped member that extends in the left - right direction. The locking shaft 145 is, for example, a columnar metal. The locking shaft 145 has two ends in the left - right direction, and these two ends are fixed to the corresponding walls that define the left and right ends of the cartridge case 101 in the left - right direction. Therefore, the locking shaft 145 does not move relative to the cartridge case 101, such as pivoting. The locking shaft 145 extends across four spaces, and four ink cartridges in the ink cartridge 30 can be respectively accommodated in these four spaces. In each of the four spaces for accommodating one ink cartridge 30, a space is provided around the locking shaft 145. Therefore, the locking shaft 145 can be accessed, for example, by the rear surface 43BF of the ink cartridge 30 that moves upward or backward.

[0072] The locking shaft 145 is used to hold the ink cartridge 30 attached to the cartridge attachment portion 110 in the attached position. By inserting the ink cartridge 30 into the cartridge attachment portion 110 and pivoting it to the operable posture, the locking shaft 145 engages with the rear surface 43BF of the rear projecting portion 43B (see Figure 4 ). In addition, the locking shaft 145 holds the ink cartridge 30 inside the cartridge attachment portion 110 against the pressing force of the helical spring 78 that pushes the ink cartridge 30 backward.

[0073] As Figure 2As shown, at the top surface 57 of the cartridge case 101, an opening 111 is formed, and one opening 111 is provided for each of the four spaces separated by the plate 104. The door 113 is exposed through a corresponding opening 111. Each door 113 has a slit 117 that opens downward and extends in the front-rear direction. Depending on the separation position of the plate 104, the left-right positions of the corresponding slits 117 of the door 113 are different from each other. The position of each slit 117 in each space is consistent with the type of ink cartridge 30 to be installed in that space in the cartridge case 101. Therefore, the rib 67 of the ink cartridge 30 (see Figure 4 ) inserted into the correct space in the cartridge case 101 where the ink cartridge 30 will be attached can pass through the slit 117 of the door 113 in that correct space. On the other hand, the rib 67 of the ink cartridge 30 inserted into the wrong space in the cartridge case 101 where the ink cartridge is not attached cannot pass through the slit 117 of the door 113 in that wrong space.

[0074] [Overall Structure of Ink Cartridge 30]

[0075] The ink cartridge 30 is a container for storing ink as a liquid. In this embodiment, four ink cartridges 30 corresponding to the respective colors of cyan, magenta, yellow, and black can be attached to the cartridge attachment portion 110. Among these four ink cartridges 30, except for the position of the rib 67 in the left-right direction, the structures of the three ink cartridges 30 corresponding to cyan, magenta, and yellow are the same as each other, as Figure 4 and Figure 8 shown. On the other hand, the ink cartridge 30 corresponding to black has a structure different from the structures of the other three ink cartridges 30 because the ink cartridge 30 for black has a larger left-right width than the left-right widths of these three ink cartridges 30. Except for this, except for the left-right position of the rib 67, the structure of the ink cartridge 30 for black is substantially the same as the structures of the other three ink cartridges 30.

[0076] Hereinafter, the structure of the ink cartridge 30 corresponding to one of the colors of cyan, magenta, and yellow will be described.

[0077] Figure 4 and Figure 5 The postures of the ink cartridge 30 depicted in and are postures in which the ink cartridge 30 can be used, i.e., operable postures. Hereinafter, Figures 4 to 5 the posture of the ink cartridge 30 shown in will also be referred to as the upright posture, and unless otherwise specified, the description will be made assuming that the ink cartridge 30 is in its upright posture. That is, the upright posture of the ink cartridge 30 is consistent with the operable posture of the ink cartridge 30 in which the ink cartridge 30 is attached to the cartridge attachment portion 110.

[0078] The ink cartridge 30 includes a lower base 130B and an outer cover 134. The outer cover 134 is assembled to the lower base 130B to form a housing 130.

[0079] The housing 130 includes a front wall (front walls 40 and 82), a rear wall (rear walls 41 and 83), a top wall 39, a bottom wall (bottom walls 42 and 48), and a pair of side walls (side walls 37, 84 and 38, 85).

[0080] The front wall of the housing 130 is the wall facing forward in the upright posture of the ink cartridge 30. The rear wall of the housing 130 is the wall facing backward in the upright posture of the ink cartridge 30. The top wall 39 of the housing 130 faces upward in the upright posture of the ink cartridge 30. The top wall 39 has a front end connected to the upper end of the front wall 82 and a rear end connected to the upper end of the rear wall 83.

[0081] In the upright posture of the ink cartridge 30, the bottom wall of the housing 130 faces downward. The bottom wall has a front end connected to the lower end of the front wall 40 and a rear end connected to the lower end of the rear wall 41. In the present embodiment, the bottom wall of the housing 130 includes a stepped wall 49. In the present embodiment, the bottom wall includes a main bottom wall 42 and a sub-bottom wall 48. In the bottom wall, the main bottom wall 42 is the wall connecting the lower end of the rear wall 41 to the lower end of the stepped wall 49. In the bottom wall, the sub-bottom wall 48 is the wall connecting the lower end of the front wall 40 to the upper end of the stepped wall 49.

[0082] In the upright posture (operable posture) of the ink cartridge 30, the direction from the rear wall of the housing 130 toward the front wall coincides with the forward direction 51, and the direction from the front wall of the housing 130 toward the rear wall coincides with the backward direction 52. Further, in the upright posture (operable posture) of the ink cartridge 30, the direction from the top wall 39 of the housing 130 toward the bottom wall coincides with the downward direction 53 (direction of gravity), and the direction from the bottom wall of the housing 130 to the top wall 39 coincides with the upward direction 54. Further, in the upright posture (operable posture) of the ink cartridge 30, the direction from the side walls 38, 85 of the housing 130 toward the side walls 37, 84 coincides with the rightward direction 55, and the direction from the side walls 37, 84 to the side walls 38, 85 of the housing 130 coincides with the leftward direction 56. Further, when the ink cartridge 30 is attached to the cartridge attachment portion 110, the outer surface of the front wall of the housing 130 faces forward; the outer surface of the rear wall of the housing 130 faces backward; the outer surface of the bottom wall of the housing 130 faces downward; and the outer surface of the top wall 39 of the housing 130 faces upward.

[0083] As Figure 4 shown, the ink cartridge 30 generally has a flat shape, and the dimensions of the flat shape in the vertical direction and the front-rear direction are respectively larger than its dimension in the left-right direction.

[0084] [Lower base 130B]

[0085] As described above, the housing 130 includes a lower base 130B and an outer cover 134.

[0086] As Figure 3 shown in the figure, the lower base 130B has a box-like shape with an upward opening. In other words, the lower base 130B has an upper end portion formed with an opening. In the present embodiment, the lower base 130B is a container made of resin. Inside the lower base 130B, a first storage chamber 32 and a second storage chamber 33 are formed.

[0087] The lower base 130B includes a front wall 40, a rear wall 41, side walls 37, 38, a main bottom wall 42, and a sub-bottom wall 48 as outer walls. The distance between the front wall 40 and the rear wall 41 is greater than the distance between the side walls 37 and 38. The front wall 40, the rear wall 41, the side walls 37, 38, the main bottom wall 42, and the sub-bottom wall 48 define the first storage chamber 32.

[0088] In the upright posture of the ink cartridge 30, the front-facing surface of the lower base 130B is the front wall 40, and the rear-facing surface of the lower base 130B is the rear wall 41. The side walls 37 and 38 respectively extend to intersect with the front wall 40 and the rear wall 41. The side walls 37 and 38 respectively connect the front wall 40, the rear wall 41, the main bottom wall 42, and the sub-bottom wall 48. In the upright posture, the side wall 37 faces right, and the side wall 38 faces left.

[0089] As Figure 4 shown in the figure, the main bottom wall 42 is inclined with respect to the front-rear direction such that its rear end is positioned higher than its front end. The front end of the main bottom wall 42 is located in front of a rear surface 43BF described later. The rear end of the main bottom wall 42 is connected to the lower end of the rear wall 41. That is, the main bottom wall 42 extends forward from the lower end of the rear wall 41. The sub-bottom wall 48 is positioned higher than the main bottom wall 42 and is located in front of the main bottom wall 42.

[0090] As Figure 3 shown in the figure, an inner cover 131 is also provided to close the opening in the upper end portion of the lower base 130B. In the present embodiment, both the inner covers 131 and 132 close the opening in the upper end portion of the lower base 130B. The space between the inner covers 131 and 132 serves as an air flow path 72 for allowing the first storage chamber 32 to open to the atmosphere. Among the two inner covers 131 and 132, the inner cover 131 is located below the inner cover 132 and defines the top plate of the first storage chamber 32. The inner cover 131 is formed with a through hole 146. Through the through hole 146, the first storage chamber 32 and the space between the two inner covers 131 and 132 (i.e., the air flow path 72) are allowed to communicate with each other. Incidentally, the through hole 146 can be opened and closed by a valve mechanism 147 provided at the inner cover 132.

[0091] As Figure 3As shown in the figure, the outer lid 134 has a box-like shape with a downward opening. The outer lid 134 is connected to the upper end portion of the lower base 130B such that the outer lid 134 covers the inner lids 131 and 132.

[0092] [Internal Structure of the Lower Base 130B]

[0093] As Figure 3 shown in the figure, the first storage chamber 32, the second storage chamber 33, the ink valve chamber 35, and the air flow path 72 are formed inside the housing 130 (lower base 130B) of the ink cartridge 30.

[0094] The lower base 130B of the housing 130 further includes a lower wall 45. The lower wall 45 is a wall extending in the front-rear direction and the left-right direction. The lower wall 45 is opposed to the inner lid 131 in the up-down direction. The first storage chamber 32 and the second storage chamber 33 are separated by the lower wall 45.

[0095] In the upright posture, the second storage chamber 33 is located below the first storage chamber 32 in the internal space of the housing 130 and is used to store ink in the second storage chamber 33. The capacity of the second storage chamber 33 for accommodating ink therein is smaller than the capacity of the first storage chamber 32 for accommodating ink therein.

[0096] The second storage chamber 33 communicates with the first storage chamber 32 through a communication port 47 formed in the lower wall 45. The communication port 47 is formed in the rear end portion and the right end portion of the lower wall 45. In addition, the second storage chamber 33 communicates with the ink valve chamber 35 through a through hole 99 formed in the partition wall 50 (see Figure 3 ).

[0097] [Air Flow Path 72]

[0098] As Figure 3 shown in the figure, the air flow path 72 is a space allowing the first storage chamber 32 to communicate with the atmosphere. The space between the two inner lids 131 and 132 communicates with the atmosphere through a through hole (not shown) formed in the higher inner lid 132 and another through hole formed in the outer lid 134. The air flow path 72 can be opened and closed by a valve mechanism 147. The valve mechanism 147 is configured to abut against a rib 118 of the cartridge housing 101 (see Figure 3 ) during the attachment of the ink cartridge 30 to the cartridge housing 101, and the rib 118 projects downward from the top surface 57 of the cartridge housing 101. Due to abutting against the rib 118, the valve mechanism 147 is pushed downward to open the air flow path 72.

[0099] [Ink Supply Unit 34]

[0100] As Figure 3 and Figure 4As shown in [Fig.], the ink supply section 34 extends forward from the housing 130, more specifically, from the stepped wall 49 of the lower base 130B. As Figure 3 shown in [Fig.], the ink supply section 34 includes a hollow cylinder 75, a seal 76, a valve 77, a helical spring 78, and a cap 79.

[0101] The cylinder 75 projects from the stepped wall 49 in the forward direction 51. The cylinder 75 has a cylindrical profile. The cylinder 75 has a front end formed with an opening. The cylinder 75 defines an internal space therein that serves as the ink valve chamber 35. The ink valve chamber 35 extends in the front-rear direction. The cylinder 75 has a front-facing end portion. The end portion of the cylinder 75 is located below and behind the front wall 40.

[0102] The seal 76 is a generally disk-shaped member. The seal 76 is made of an elastic material such as rubber or elastomer. The seal 76 is disposed at the front end of the cylinder 75 to cover the opening in the front end. The seal 76 has a central portion formed with a through hole that penetrates the seal 76 in the front-rear direction. The tubular inner peripheral surface defining the through hole provides a through hole 73 in the seal 76. The diameter of the through hole 73 is slightly smaller than the outer diameter of the ink supply tube 102.

[0103] The valve 77 and the helical spring 78 are accommodated in the ink valve chamber 35. The valve 77 is movable in the forward direction 51 and the backward direction 52 so as to be able to contact the seal 76 and separate from the seal 76. The helical spring 78 pushes the valve 77 forward. Thus, in the absence of an external force, the valve 77 closes the through hole 73 of the seal 76.

[0104] As Figure 4 shown in [Fig.], the cap 79 has a generally rectangular parallelepiped outer shape. The cap 79 is hollow. Incidentally, the cap 79 may have a shape other than a rectangular parallelepiped as long as the cap 79 is a hollow member having openings at its front end and rear end. As Figure 3 shown in [Fig.], the cap 79 has a front surface formed with an ink supply port 71. In a state where the cap 79 covers the cylinder 75 and the seal 76, the ink valve chamber 35 communicates with the outside of the ink cartridge 30 through the through hole 73 of the seal 76 and the ink supply port 71 of the cap 79.

[0105] As Figure 3 shown in [Fig.], in a state where the cap 79 covers the cylinder 75 and the seal 76, the seal 76 is fixed while being sandwiched between the cap 79 and the cylinder 75. In addition, the gaps between the seal 76 and the cylinder 75 and between the seal 76 and the cap 79 are liquid-tightly sealed.

[0106] [Outer cover 134]

[0107] As Figures 3 to 5As shown, the outer cover 134 is located on top of the lower base 130B. In other words, the outer cover 134 is positioned higher than the ink supply section 34. The outer cover 134 has a box-like shape with a downward opening. The outer cover 134 includes a top wall 39, a front wall 82, a rear wall 83, a side wall 84, and a side wall 85. The front wall 82 is connected to the front end of the top wall 39 and extends downward from the front end of the top wall 39. The rear wall 83 is connected to the rear end of the top wall 39 and extends downward from the rear end of the top wall 39. The side wall 84 extends downward from the right end of the top wall 39 to connect the front wall 82 and the rear wall 83. The side wall 85 extends downward from the left end of the top wall 39 to connect the front wall 82 and the rear wall 83.

[0108] As Figure 4 As shown, the side wall 85 is formed with three engaging holes 86. Although not shown in the figure, the side wall 84 is also formed with three engaging holes 86. In each of the side walls 84 and 85, the three engaging holes 86 are arranged to be spaced apart from each other in the front-rear direction. When viewed in the left-right direction, the three engaging holes 86 formed in the side wall 84 and the three engaging holes 86 formed in the side wall 85 are at the same front-rear positions that overlap each other.

[0109] The engaging claws 88 of the lower base 130B engage with each of the engaging holes 86. The outer cover 134 is thus coupled to the lower base 130B from above to cover the lower base 130B. Incidentally, in the present embodiment, the engaging holes 86 are formed in the outer cover 134, and the engaging claws 88 are formed at the lower base 130B. Alternatively, the engaging claws 88 may be formed at the outer cover 134, and the engaging holes 86 may be formed in the lower base 130B. In a state where the outer cover 134 is assembled to the lower base 130B, the front wall 82 and 40 constitute the front-facing outer surface of the ink cartridge 30. In addition, the rear wall 83 and 41 constitute the rear-facing outer surface of the ink cartridge 30. In addition, the side wall 84 and 37 and the side wall 85 and 38 respectively constitute the side-facing outer surfaces of the ink cartridge 30.

[0110] The top wall 39 includes a first main top wall 61, a second main top wall 62, and a sub-top wall 63. The first main top wall 61 is located rearward in the front-rear direction. The second main top wall 62 extends from the first main top wall 61 and is located in front of the first main top wall 61. The sub-top wall 63 extends from the second main top wall 62 and is located in front of the second main top wall 62. The first main top wall 61 has an upper surface that is a flat surface extending in the left-right direction and the front-rear direction. The second main top wall 62 has an upper surface that is a flat surface extending in the left-right direction and the front-rear direction, and is positioned lower than the upper surface of the first main top wall 61. The sub-top wall 63 has an upper surface that is an inclined flat surface extending in the left-right direction and sloping downward forward. Thus, the upper surface of the sub-top wall 63 is positioned lower than the upper surface of the second main top wall 62.

[0111] As shown Figure 4 and Figure 5 as shown in Figure 4 and Figure 5 , a first main top wall 61 is formed with a slot 44 extending in the front-rear direction. The slot 44 is located above a through hole 146 of the inner lid 131.

[0112] On the first main top wall 61, a protrusion 43 is formed to protrude upward. The protrusion 43 is immovable relative to the top wall 39 in the up-down direction and the front-rear direction. The protrusion 43 includes a right protrusion 43R, a left protrusion 43L, and a rear protrusion 43B. The right protrusion 43R and the left protrusion 43L are positioned to be spaced apart from each other in the left-right direction. The right protrusion 43R and the left protrusion 43L extend in the front-rear direction, respectively. The rear protrusion 43B extends in the left-right direction to connect the rear ends of the right protrusion 43R and the left protrusion 43L. The right protrusion 43R, the left protrusion 43L, and the rear protrusion 43B define the right edge, the left edge, and the rear edge of the slot 44, respectively. The rear protrusion 43B has a rear surface 43BF through which the locking shaft 145 can be accessed.

[0113] The rear surface 43BF is the rear-facing surface of the protrusion 43. The rear surface 43BF is positioned higher than the top wall 39. The rear surface 43BF extends in the up-down direction. In a state where the ink cartridge 30 is attached to the cartridge attachment portion 110, the rear surface 43BF is a surface that can face rearward and contact the locking shaft 145. Through the rear surface 43BF that faces rearward and contacts the locking shaft 145, the ink cartridge 30 can be held in the cartridge attachment portion 110 against the pushing force of the spiral spring 78.

[0114] In the protrusion 43, the right protrusion 43R and the left protrusion 43L are formed in front of the rear surface 43BF, with the slot 44 therebetween. Each of the right protrusion 43R and the left protrusion 43L has an upper surface composed of a horizontal surface 154 and an inclined surface 155. The horizontal surface 154 is connected to the rear surface 43BF. The inclined surface 155 is located in front of the horizontal surface 154. The inclined surface 155 is connected to the horizontal surface 154. The inclined surface 155 faces upward and forward. The inclined surface 155 is inclined with respect to the front-rear direction such that its front end is positioned lower than its rear end. The rear surface 43BF and the inclined surface 155 are connected to each other via the horizontal surface 154. Therefore, the boundary edge between the rear surface 43BF and the inclined surface 155 does not form a ridge shape. During the insertion of the ink cartridge 30 into the cartridge attachment portion 110, the locking shaft 145 can be smoothly guided to the rear surface 43BF by the inclined surface 155 and the horizontal surface 154 while contacting the rear surface 43BF.

[0115] On the first main top wall 61, the operation unit 90 is also provided at a position behind the rear surface 43BF. The operation unit 90 is adapted to be accessed and operated by the user. The operation unit 90 is integrally formed with the outer lid 134.

[0116] Incidentally, each of the outer surfaces of the front walls 40 and 82, the rear walls 41 and 83, the top wall 39, the main bottom wall 42, the sub-bottom wall 48, the side walls 37 and 84, and the side walls 38 and 85 does not have to be a single flat surface. That is, the outer surfaces of the front walls 40 and 82 are the surfaces that can be observed when the ink cartridge 30 in the upright posture is observed from the front toward the rear, and the outer surfaces of the front walls 40 and 82 are positioned in front of the front-rear center of the ink cartridge 30 in the upright posture. The outer surfaces of the rear walls 41 and 83 are the surfaces that can be observed when the ink cartridge 30 in the upright posture is observed from the rear toward the front, and the outer surfaces of the rear walls 41 and 83 are positioned behind the front-rear center of the ink cartridge 30 in the upright posture. The outer surface of the top wall 39 (i.e., the outer surfaces of the first main top wall 61, the second main top wall 62, and the sub-top wall 63) is the surface that can be observed when the ink cartridge 30 in the upright posture is observed from above, and the outer surface of the top wall 39 is located above the center of the ink cartridge 30 in the upright posture with respect to the vertical direction. The outer surfaces of the main bottom wall 42 and the sub-bottom wall 48 are the surfaces that can be observed when the ink cartridge 30 in the upright posture is observed from below, and the outer surfaces of the main bottom wall 42 and the sub-bottom wall 48 are positioned below the center of the ink cartridge 30 in the upright posture with respect to the vertical direction. This can also be applied to the outer surfaces of the side walls 37, 38, 84, and 85, respectively.

[0117] Incidentally, the housing 130 of the ink cartridge 30 does not have to include the lower base 130B and the outer lid 134. In addition, the chamber for storing ink does not have to be divided into the first storage chamber 32 and the second storage chamber 33. That is, the ink cartridge 30 may include a housing in which there is a storage chamber defined by the top wall 39, the front wall 40, the rear wall 41, the side walls 37, the side walls 38, the main bottom wall 42, and the sub-bottom wall 48.

[0118] As Figure 4 and Figure 5As shown, ribs 67 are formed on the upper surfaces of the second main top wall 62 and the sub-top wall 63 to project upward. The ribs 67 are immovable relative to the top wall 39 in the vertical direction and the front-rear direction. The ribs 67 extend in the front-rear direction to span the upper surfaces of the second main top wall 62 and the sub-top wall 63. The ribs 67 are located in front of the protrusion 43. The ribs 67 are located in front of the IC board 64, which will be described later. The ribs 67 have a flat plate shape, and their front-rear dimension is larger than their left-right dimension and vertical dimension. The ribs 67 have a front surface (front end 67F), a main upper surface 68, and a sub-upper surface 69. The main upper surface 68 is a flat surface that extends in the front-rear direction and the left-right direction. The sub-upper surface 69 is connected to the main upper surface 68 and is located in front of the main upper surface 68. The sub-upper surface 69 is an inclined flat surface that is inclined downward in the forward direction relative to the front-rear direction. The front-rear dimension of the main upper surface 68 is larger than the front-rear dimension of the sub-upper surface 69. The sub-upper surface 69 is positioned higher than the sub-top wall 63.

[0119] As Figure 4 and Figure 8 shown, the left-right positions of the ribs 67 on the second main top wall 62 vary according to the type of the ink cartridge 30 (such as the type and initial amount of ink stored in the ink cartridge 30). When inserted into the correct position in the cartridge attachment portion 110, the ribs 67 can pass through the slit 117 of the door 113. However, when inserted into a position where the ink cartridge 30 should not be attached (another door 113), the ribs 67 cannot pass through the slit 117 of the other door 113. In addition, the user can visually confirm the left-right positions of the ribs 67 to identify the type of the ink cartridge 30.

[0120] [IC board 64]

[0121] As Figure 4 and Figure 5 shown, the IC board 64 is provided at the upper surface of the first main top wall 61 and at a position between the ribs 67 and the protrusion 43 in the front-rear direction. In other words, the IC board 64 is directly supported on the top wall 39 of the outer cover 134. More specifically, a support portion 66 is formed on the upper surface of the first main top wall 61 to project upward from the upper surface, and the IC board 64 is fixed to the outer cover 134 by being coupled to the support portion 66. During the insertion of the ink cartridge 30 into the cartridge attachment portion 110, the IC board 64 is electrically connected to three contact members 106 (see Figure 3 ), and in the state where the ink cartridge 30 is attached to the cartridge attachment portion 110, the IC board 64 is also electrically connected to the contact members 106.

[0122] The IC board 64 includes a substrate, an IC (not shown in the figure), and three electrodes 65. The substrate supports the IC. The three electrodes 65 are formed on the substrate. The three electrodes 65 and the IC are electrically connected to each other. The three electrodes 65 extend respectively in the front-rear direction and are arranged in the left-right direction. The three electrodes 65 are disposed on the upper surface of the substrate such that the electrodes 65 are exposed to allow electrical access thereto. With this configuration, the three contact members 106 of the cartridge case 101 can be in direct contact with the upper surfaces of the three electrodes 65 respectively. The IC is an integrated circuit and stores data indicating information related to the ink cartridge 30, such as lot number, manufacturing date, and color of ink, in a readable manner. Incidentally, the substrate may be a so-called rigid substrate or may be a flexible substrate having flexibility. Further, the number of the electrodes 65 is not limited and may be four, for example.

[0123] [Position of each element in the ink cartridge 30]

[0124] Hereinafter, with reference to Figure 5 the attitude of the ink cartridge 30 shown in, the positions of the corresponding elements in the state of observing the ink cartridge 30 from the left-right direction will be described.

[0125] The horizontal surface 154, which is the upper surface of the protrusion 43, is positioned higher than the upper edge 67FU of the front end 67F of the rib 67. The front end 67F of the rib 67 is defined as the front surface that extends upward from the sub-top wall 63 and faces forward. The upper edge 67FU is the boundary between the sub-upper surface 69 and the front surface (front end 67F) that extends upward from the sub-top wall 63 and faces forward. The horizontal surface 154 of the protrusion 43 is located behind the center point C1 of the housing 130 in the front-rear direction. The protrusion 43 is located on the upper surface of the first main top wall 61. The upper edge 67FU of the front end 67F of the rib 67 is located in front of the center point C1. The front end 67F of the rib 67 is located in front of the ink supply port 71 of the ink supply section 34. The front end 67F of the rib 67 is located at the sub-top wall 63. More specifically, the front end 67F of the rib 67 is positioned to be spaced apart from the front wall 82 in the front-rear direction and from each of the side walls 84 and 85 in the left-right direction. That is, the front end 67F of the rib 67 is positioned to be away from the periphery of the top wall 39 in terms of both the front-rear direction and the left-right direction.

[0126] The front end 67F of the rib 67 is positioned further forward than any of the engagement holes 86. The rear end 67R of the rib 67 (i.e., the end opposite to the front end 67F in the front-rear direction) is further rearward than the engagement hole 86 that is the most forward in the front-rear direction among the engagement holes. The rib 67 extends across more than half of the front-rear dimension D1, which is the sum of the front-rear dimensions of the upper surfaces of the second main top wall 62 and the sub-top wall 63. In this structure, since the upper wall 39 of the outer cover 134 is strengthened by the rib 67, the upper wall 39 is difficult to deform even when an external force is applied to the upper wall 39. Therefore, deformation of the peripheral wall (side walls 84 and 85) of the outer cover 134 in a manner that increases the gap distance in the left-right direction between the side walls 84 and 85 is suppressed, and thus, the engagement between the engagement claws 88 and the engagement holes 86 is unlikely to be released.

[0127] In Figure 5 it, the imaginary plane 150 is indicated by a dashed line. The imaginary plane 150 passes through each of the first point and the second point. Here, the first point is a point on the upper surface of the protrusion 43. More specifically, in the present embodiment, the first point on the upper surface of the protrusion 43 is on the boundary 156 between the horizontal surface 154 and the inclined surface 155. In other words, in the present embodiment, the first point is the highest point on the upper surface of the protrusion 43. The second point in the present embodiment is defined as the upper edge 67FU of the front end 67F of the rib 67. The imaginary plane 150 also extends in the left-right direction. Note that the protrusion 43 and the rib 67 are located below the imaginary plane 150, which means that the imaginary plane 150 is assumed not to cross the protrusion 43 and the rib 67. Therefore, in Figure 5 the side view of the ink cartridge 30 depicted in it, the imaginary plane 150 contacts the protrusion 43 at the boundary 156, and the imaginary plane 150 contacts the rib 67 at the upper edge 67FU.

[0128] In the region between the first point (the boundary 156 of the protrusion 43) and the second point (the upper edge 67FU of the front end 67F of the rib 67) in the front-rear direction, the entire outer surface (outline) of the ink cartridge 30 is located below the imaginary plane 150. In other words, in the region between the first point (the boundary 156) and the second point (the upper edge 67FU) in the front-rear direction, no part of the ink cartridge 30 is positioned above the imaginary plane 150. Therefore, the boundary 70 between the upper surface of the second main top wall 62 and the upper surface of the sub-top wall 63 is located below the imaginary plane 150. In addition, the entire IC board 64 is located below the imaginary plane 150. In addition, the front end of the top wall 39 (i.e., the front end 63F of the sub-top wall 63) is located below the imaginary plane 150.

[0129] Here, the term "portion" of the ink cartridge 30 may be: any portion integrally formed with the housing 130; any portion detachably connected to the housing 130; or any portion belonging to the body to be attached to the housing 130 when the ink cartridge 30 is installed in and used in the printer 10.

[0130] In addition, the front edge 65F of each electrode 65 in the IC board 64 is located behind the center point C2 in the front-back direction of the region between the first point (the boundary 156 of the protrusion 43) and the second point (the upper edge 67F of the front end 67F of the rib 67), and the imaginary plane 150 passes through each of the first point and the second point. That is, the distance in the front-back direction between the center point C2 and the first point is equal to the distance in the front-back direction between the center point C2 and the second point.

[0131] The distance L1 in the front-back direction from the front edge 65F of the electrode 65 in the IC board 64 to the boundary 156 (the first point, i.e., the contact point between the protrusion 43 and the imaginary plane 150) is shorter than the distance L2 in the front-back direction from the front edge 65F of the electrode 65 on the IC board 64 to the upper edge 67FU of the front end 67F of the rib 67 (the second point, i.e., the contact point between the rib 67 and the imaginary plane 150). That is, the formula L1 < L2 is satisfied.

[0132] In addition, referring to Figure 5 , in the side view of the ink cartridge 30 in the left-right direction, the imaginary plane 150 can also be defined as an imaginary line including at least the following two points: the first point (the boundary 156 of the protrusion 43); and the second point (the upper edge 67FU of the front end 67F of the rib 67). At this time, in the entire region in the front-back direction from the front wall 40 (the foremost edge of the housing 130) to the rear wall 41 (the rearmost edge of the housing 130), the contour of the ink cartridge 30 is located below the imaginary plane 150 ( Figure 5 the dotted line in).

[0133] The distance L1 in the front-back direction from the front edge 65F of the electrode 65 in the IC board 64 to the boundary 156 of the protrusion 43 included in the imaginary line (the imaginary plane 150) is less than the distance L2 in the front-back direction from the front edge 65F of the electrode 65 in the IC board 64 to the upper edge 67FU of the rib 67 included in the imaginary line (the imaginary plane 150).

[0134] In addition, the horizontal surface 154 which is the upper surface of the protrusion 43 is positioned closer to the rearmost edge of the housing 130 than to the foremost edge of the housing 130 in the front-back direction. The sub-upper surface 69 of the rib 67 is positioned closer to the foremost edge of the housing 130 than to the rearmost edge of the housing 130 in the front-back direction.

[0135] [Technical Advantages of the Embodiment]

[0136] In the ink cartridge 30 according to the described embodiment, in the region between a first point (the boundary 156 of the protrusion 43) and a second point (the upper edge 67FU of the front end 67F of the rib 67) in the front-rear direction, no part of the ink cartridge 30 is positioned above the imaginary plane 150. That is, in the region between the first point (the boundary 156 of the protrusion 43) and the second point (the upper edge 67FU of the front end 67F of the rib 67) in the front-rear direction, the outer surface (the contour of the liquid cartridge 30) of any part of the ink cartridge 30 is located below the imaginary plane 150. Therefore, when the ink cartridge 30 falls upside down onto the floor 160, in particular, the horizontal surface 154 of the protrusion 43 first collides with the floor 160, as Figure 6 depicted. Thereafter, due to gravity or its acceleration, the ink cartridge 30 pivots clockwise in Figure 6 and then the upper edge 67FU of the front end 67F of the rib 67 collides with the floor 160, as Figure 7 shown. With this structure, compared with the configuration of the ink cartridge 30 without the rib 67, when the dropped ink cartridge 30 collides with the floor 160, the change (angular rotation) in the attitude of the housing 130 is smaller. Therefore, it is less likely that ink splashes through the ink supply port 71 of the ink supply unit 34. Incidentally, Figure 7 the state depicted in

[0137] is a state where the protrusion 43 and the rib 67 of the ink cartridge 30 are in contact with the same plane (i.e., the floor 160 or the imaginary plane 150). In this state, a gap is vertically formed between the imaginary plane 150 and the IC board 64.

[0138] In addition, in the ink cartridge 30 of the present embodiment, the front end 67F of the rib 67 is located in front of the ink supply port 71 of the ink supply unit 34 in the forward direction 51. That is, compared with a conventional cartridge in which the ink supply unit is located in front of the front end 67F of the rib 67, the front-rear dimension of the rib 67 can be made longer.

[0139] In contrast, in the ink cartridge 30 according to the present embodiment, the front end 67F of the rib 67 is located in front of the ink supply portion 34 provided at the housing 130 (lower base 130B) in which the first storage chamber 32 and the second storage chamber 33 are defined. In the case of the structure of the present embodiment, compared with the above-described conventional cartridge, when the ink cartridge 30 drops onto the floor 160, the amount of pivoting (angular rotation amount) of the ink cartridge 30 can be made smaller. Therefore, the rotational torque applied to the ink supply portion 34 at the time of collision with the floor 160 can also be made smaller, thereby reducing the risk of ink leakage through the ink supply port 71. The ink cartridge 30 according to the present embodiment can thus suppress ink leakage through the ink supply portion 34 when dropped onto the floor 160 without reducing the volume of the storage chamber in the housing 130.

[0140] In addition, the longer front-rear dimension of the rib 67 of the present embodiment can also be used to mitigate the impact transmitted to the top wall 39 when the rib 67 collides with a flat plane such as the floor 160, and can provide enhanced strength to the top wall 39 of the housing 130.

[0141] Still further, in the present embodiment, the protrusion 43 and the rib 67 project upward from the top wall 39 and are immovable in the vertical direction relative to the top wall 39. The IC board 64 is located between the protrusion 43 and the rib 67 in the front-rear direction and is lower than the imaginary plane 150 that passes through each of the first point (the boundary 156 on the upper surface of the protrusion 43) and the second point (the upper edge 67FU of the front end 67F of the rib 67), and the imaginary plane 150 extends in the left-right direction. In the case of this structure, when the ink cartridge 30 drops onto a flat plane such as the floor 160, a gap (void) can be reliably formed between the flat plane (the floor 160) and the IC board 64. Therefore, the IC board 64 can be reliably protected from the impact when the ink cartridge 30 drops onto the floor 160.

[0142] In addition, the front end 63F of the sub-top wall 63 is located below the imaginary plane 150. Therefore, the front end 63F of the sub-top wall 63 is less likely to be damaged when dropped onto the floor 160.

[0143] In addition, since the rib 67 is in the form of a wall that is elongated in the front-rear direction, it is difficult for the rib 67 to interfere with the components of the cartridge case 101 during the attachment of the ink cartridge 30 to the cartridge case 101. In addition, since the front-rear dimension of the rib 67 is larger than its vertical dimension, even when the rib 67 contacts the floor 160 due to the ink cartridge 30 dropping onto the floor 160, the rib 67 is difficult to be damaged. In addition, the protrusion 43 is composed of a right protrusion 43R and a left protrusion 43L that are connected to each other by a rear protrusion 43B. Therefore, the protrusion 43 has a higher impact resistance than the rib 67.

[0144] In addition, the front edge 65F of the electrode 65 is positioned further rearward than the center point C2. Therefore, a gap (clearance) can be reliably ensured in the vertical direction between the imaginary plane 150 and the IC board 64 (electrode 65). In the case of this structure, when the ink cartridge 30 drops and collides with a flat surface, for example, the IC board 64 abuts against the floor 160, and such an impact hardly causes any loss of function of the IC board 64.

[0145] In addition, the outer lid 134 includes a front wall 82 and side walls 84 and 85 as peripheral walls extending downward from the periphery of the top wall 39. The front end 67F of the rib 67 is positioned to be spaced apart from the front wall 82 in the front-rear direction and from each of the side walls 84 and 85 in the left-right direction. In the case of this structure, since the front end 67F of the rib 67 is spaced apart from the front wall 82 and each of the side walls 84 and 85, an external impact applied to the front wall 82 and the side walls 84, 85 is less likely to be transmitted to the rib 67. Therefore, deformation of the rib 67 due to an impact can be suppressed.

[0146] [Variant]

[0147] In the depicted embodiment, the support portion 66 is provided on the first main top wall 61 of the outer lid 134, and the first main top wall 61 directly supports the IC board 64. However, instead of the support portion 66, a separate support member can be assembled to the first main top wall 61 for supporting the IC board 64. That is, the first main top wall 61 can indirectly support the IC board 64 instead of directly supporting the IC board 64. Incidentally, a support member detachably attached to the top wall 39 for supporting the IC board 64 can constitute a "portion" of the ink cartridge 30 that is located below the imaginary plane 150 in the region between the first point and the second point in the front-rear direction (see the 18th paragraph counting forward from this paragraph). Therefore, when the ink cartridge 30 drops onto the floor 160, after the protrusion 43 abuts against the floor 160, such a detachable "portion" provided separately from the housing 130 for supporting the IC board 64 can prevent the IC board 64 from directly colliding with a flat surface such as the floor 160.

[0148] In addition, the entire IC board 64 supported by the support portion 66 does not have to be exposed to the outside. For example, as Figure 9 shown, only the portion of the IC board 64 where the electrode 65 is located can be exposed to the outside of the support portion 66, and the remaining portion of the IC board 64 can be accommodated inside the support portion 66. Here, the support portion 66 does not have to be fixed to the top wall 39, but can be a separate member detachably attached to the top wall 39 for supporting the IC board 64.

[0149] In addition, in the above-described embodiment, the front edge 65F of each electrode 65 in the IC board 64 is positioned further rearward than the front-rear center point C2 in the region between the first point (the boundary 156 of the protrusion 43) and the second point (the upper edge 67FU of the front end 67F of the rib 67) in the front-rear direction, and the imaginary plane 150 contacts each of the first point and the second point. Further preferably, the front edge of the IC board 64 may also be positioned further rearward than the center point C2.

[0150] Incidentally, in the present embodiment, both the protrusion 43 and the rib 67 project upward from the top wall 39. That is, the protrusion 43 and the rib 67 are integrally formed with the top wall 39. However, the protrusion 43 and the rib 67 (the first protrusion and the second protrusion of the present disclosure) do not have to be integral with the top wall 39 of the outer cover 134, but may be configured as members detachably connected to the top wall 39. That is, the first protrusion and the second protrusion of the present disclosure may be provided separately from the top wall 39 and vertically pass through the top wall 39 (for example, through a through hole in the top wall 39) so that the first protrusion and the second protrusion project upward relative to the top wall 39.

[0151] In addition, in the above-described ink cartridge 30, in a state where the ink cartridge 30 is attached to the cartridge case 101, the rear surface 43BF of the protrusion 43 engages with the locking shaft 145. Alternatively, the ink cartridge 30 can be held in an attached state relative to the cartridge case 101 by engaging or contacting a part of the ink cartridge 30 other than the protrusion 43 with a component of the cartridge case 101.

[0152] In addition, in the depicted embodiment, the valve mechanism 147 is located between the right protruding portion 43R and the left protruding portion 43L of the protrusion 43. However, the valve mechanism 147 and the air flow path 72 can be provided at a position away from the protrusion 43. If this is the case, the right protruding portion 43R and the left protruding portion 43L of the protrusion 43 can be used only to provide a space for receiving the rib 118 of the cartridge case 101 during attachment of the ink cartridge 30 to the cartridge case 101.

[0153] In the depicted embodiment, ink is described as an example of the liquid. However, instead of ink, a pretreatment liquid that is ejected onto the sheet before the ink during a printing operation can be stored in the liquid cartridge. Alternatively, cleaning water for cleaning the recording head 21 can be stored in the liquid cartridge. That is, the ink cartridge 30 of the present disclosure does not have to be a cartridge for storing ink, but can be a cartridge for storing a liquid to be consumed in the printer 10.

[0154] <Remarks>

[0155] In the present disclosure, the ink cartridge 30 is an example of a liquid cartridge. The housing 130 is an example of a housing. The IC board 64 is an example of a circuit board. The electrode 65 is an example of an electrode. The ink supply section 34 is an example of a liquid supply section. The ink valve chamber 35 is an example of a liquid passage. The top wall 39 is an example of a top wall. The protrusion 43 is an example of a first protrusion. The rib 67 is an example of a second protrusion. The front end 67F is an example of the front end of the second protrusion. The upper edge 67FU is an example of the upper edge of the front end of the second protrusion. The horizontal surface 154 and the inclined surface 155 of the protrusion 43 are examples of the upper surface of the first protrusion. The imaginary plane 150 is an example of an imaginary line. The rear surface 43BF is an example of a joint surface. The first main top wall 61 and the second main top wall 62 are examples of a first part of the top wall. The sub-top wall 63 is an example of a second part of the top wall. The main upper surface 68 is an example of the main upper surface of the second protrusion. The rear end 67R is an example of the rear end of the second protrusion. The sub-upper surface 69 is an example of the sub-upper surface of the second protrusion. The center point C1 is an example of the center point of the housing in the depth direction. The lower base 130B is an example of a base. The outer cover 134 is an example of a cover. The engagement hole 86 is an example of an engagement hole. The engagement claw 88 is an example of an engagement claw. The forward direction is an example of the depth direction. The rightward direction 55 and the leftward direction 56 are examples of the width direction. The downward direction 53 is an example of the direction of gravity. The upward direction 54 is an example of the height direction.

Claims

1. A liquid cartridge, comprising: a housing that defines a liquid storage chamber therein; a circuit board that includes electrodes; and a liquid supply portion that extends from the housing in a depth direction intersecting with the direction of gravity, and the liquid supply portion has an opening facing forward in the depth direction, a liquid passage is defined in the liquid supply portion, the liquid passage connects the liquid storage chamber to the opening, and the liquid passage is configured to allow the liquid in the liquid storage chamber to flow out of the housing through the opening, wherein the housing includes: a top wall, the circuit board is disposed at the top wall, in the upright posture of the liquid cartridge, the top wall faces upward and is located above the liquid supply portion; a first protrusion that protrudes upward from the top wall, and the first protrusion is located behind the circuit board in the depth direction; and a second protrusion that protrudes upward from the top wall, and the second protrusion is located in front of the circuit board in the depth direction, the second protrusion extends in the depth direction, and the second protrusion has a front end facing forward in the depth direction, wherein in the upright posture of the liquid cartridge, the first protrusion is positioned higher than the upper edge of the front end of the second protrusion; wherein the front end of the second protrusion is located in front of the opening of the liquid supply portion in the depth direction, and wherein, in the upright posture of the liquid cartridge, in a region between a first point on the first protrusion and a second point on the second protrusion in the depth direction, no part of the liquid cartridge is positioned higher than a hypothetical plane in a height direction opposite to the direction of gravity, the second point is defined as the upper edge of the front end of the second protrusion, the hypothetical plane passes through each of the first point and the second point, and the hypothetical plane extends in a width direction perpendicular to the depth direction and the direction of gravity, and the first protrusion and the second protrusion are located below the hypothetical plane.

2. The liquid cartridge according to claim 1, wherein the top wall has a front end facing forward in the depth direction, and in the upright posture of the liquid cartridge, the front end is located below the hypothetical plane.

3. The liquid cartridge according to claim 1 or 2, wherein the first protrusion has an upper surface that includes the first point, wherein the housing defines a center point of the housing in the depth direction, and the upper surface of the first protrusion is located behind the center point of the housing in the depth direction, and wherein the upper edge of the front end of the second protrusion is located in front of the center point of the housing in the depth direction.

4. The liquid cartridge according to claim 1 or 2, wherein the top wall directly or indirectly supports the circuit board.

5. The liquid cartridge according to claim 1 or 2, wherein the first protrusion comprises: A first protrusion that extends in the depth direction and has a rear end facing backward in the depth direction; A second protrusion that extends in the depth direction and is positioned to be spaced apart from the first protrusion in the width direction, the second protrusion having a rear end facing backward in the depth direction; and A third protrusion that extends in the width direction and connects the rear end of the first protrusion to the rear end of the second protrusion, and wherein the second protrusion has a dimension in the depth direction greater than its dimension in the gravity direction and its dimension in the width direction.

6. The liquid cartridge according to claim 5, wherein the third protrusion has a mating surface facing backward in the depth direction for mating with a part of the cartridge housing when the liquid cartridge is attached to the cartridge housing.

7. The liquid cartridge according to claim 1 or 2, wherein the top wall of the housing comprises: A first part that extends in the depth direction; and A second part that is inclined with respect to the depth direction to extend downward and forward from the first part in the upright attitude of the liquid cartridge, the first part and the second part defining a boundary therebetween, wherein the front end of the second protrusion is located on the second part and the second protrusion extends across the boundary between the first part and the second part.

8. The liquid cartridge according to claim 7, wherein in the upright attitude of the liquid cartridge, the boundary is located below the imaginary plane.

9. The liquid cartridge according to claim 1 or 2, wherein in the upright attitude of the liquid cartridge, the entire circuit board is located below the imaginary plane.

10. The liquid cartridge according to claim 1 or 2, wherein the housing comprises: A base in which the liquid storage chamber is defined, the base having an upper end that opens upward in the upright attitude of the liquid cartridge; and A lid that engages with the base to cover the upper end of the base, the lid including the top wall and directly or indirectly supporting the circuit board.

11. The liquid cartridge according to claim 10, wherein the base includes a plurality of engaging claws for engaging with the lid, and wherein the lid further includes a peripheral wall extending downward from the periphery of the top wall, the peripheral wall being formed with a plurality of engaging holes, each engaging hole receiving a corresponding one of the engaging claws, and wherein the front end of the second protrusion is positioned further forward in the depth direction than any of the engaging holes that engage with the corresponding engaging claws.

12. The liquid cartridge according to claim 11, wherein the second protrusion has a rear end opposite to the front end in the depth direction, and the rear end of the second protrusion is positioned further rearward than the frontmost one of the plurality of engagement holes in the depth direction.

13. The liquid cartridge according to claim 1, wherein the housing further includes a peripheral wall extending downward from the periphery of the top wall, the peripheral wall comprising: a front wall facing forward in the depth direction; a first side wall extending from the front wall in the depth direction; and a second side wall extending from the front wall in the depth direction, and the second side wall is spaced apart from the first side wall in the width direction, wherein the front end of the second protrusion is positioned to be spaced apart from the front wall in the depth direction and spaced apart from each of the first side wall and the second side wall in the width direction.

14. The liquid cartridge according to any one of claims 1, 2, and 13, wherein the first protrusion comprises: an inclined surface inclined with respect to the depth direction; and a horizontal surface connected to the inclined surface, and the horizontal surface is located behind the inclined surface in the depth direction. In the upright posture of the liquid cartridge, the horizontal surface extends in the depth direction, and wherein the first point is on the boundary between the inclined surface and the horizontal surface.

15. The liquid cartridge according to any one of claims 1, 2, and 13, wherein the second protrusion is plate-shaped, and the second protrusion has: a front surface extending from the top wall and facing forward in the depth direction, and the front end of the second protrusion has the front surface; a main upper surface extending in the depth direction, and in the upright posture of the liquid cartridge, the main upper surface faces upward; and a sub-upper surface extending from the main upper surface and inclined with respect to the depth direction. In the upright posture of the liquid cartridge, the sub-upper surface is inclined downward and forward, and wherein the upper edge of the front end of the second protrusion is defined by the front surface and the sub-upper surface.

16. The liquid cartridge according to any one of claims 1, 2, and 13, wherein the electrode has a front edge facing forward in the depth direction, and the front edge is located behind the center point of the region in the depth direction.

17. A cartridge set including a plurality of liquid cartridges according to any one of claims 1 to 16, wherein the plurality of liquid cartridges are configured to be accommodated in different spaces in a cartridge case, and the second protrusions of the plurality of liquid cartridges are at different positions in the width direction.

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