Waste liquid collecting method, liquid injecting apparatus and cartridge set

A printer includes a recording head and a maintenance mechanism for sucking an ink in the recording head. A plurality of cartridges to be attached to the printer includes a first housing portion for storing an ink to be supplied to the recording head and a second housing portion for storing a waste ink discharged from the maintenance mechanism. In a first one of the cartridges, the flow path resistance of a cartridge side flow path from a waste ink introducing portion to an air communicating hole for discharging air in a waste ink reservoir portion to an outside through the waste ink reservoir portion is lower than the flow path resistance of each of the cartridge side flow paths of the other cartridges (FIG. 14).

BACKGROUND OF THE INVENTION

The present invention relates to a waste liquid collecting method, a liquid injecting apparatus and a cartridge set.

An ink jet type recording apparatus (hereinafter referred to as a printer) has been known as a liquid injecting apparatus for discharging a liquid from a liquid injecting head to a target. A maintenance mechanism is usually provided on a non-printing region in the printer. The maintenance mechanism carries out suction cleaning for sucking a thickened ink and air bubbles from a nozzle in order to prevent the nozzle clogging of a recording head to be a liquid injecting head.

A waste ink sucked from the recording head by the maintenance mechanism is fed to a waste ink tank provided in the printer. Alternatively, the waste ink is fed to an ink cartridge including an ink reservoir portion accommodating an unused ink and a waste ink reservoir portion in some cases (for example, see JP-A-2003-118144). In these cases, the waste ink reservoir portion can also be exchanged simultaneously with the exchange of the cartridge. Therefore, it is possible to produce an advantage that a waste liquid accommodating space can be more reduced than the case in which the waste ink tank is provided in the apparatus.

In the ink cartridge described in the JP-A-2003-118144, however, also in a state in which the waste ink is not sufficiently collected, the arrangement posture of the ink cartridge is changed so that the waste ink comes in contact with an air permeable film in some cases. In general, the air permeability of the air permeable film is not reduced even if the waste ink sticks thereto several times. In the case in which the waste ink often sticks and the sticking waste ink is then dried, however, there is a possibility that the air permeability might be reduced. When the air permeability of the air permeable film is reduced, air sucked from the nozzle opening of the recording head together with the waste ink cannot be discharged from a hole. As a result, a waste ink introducing chamber is filled with the air so that the waste ink cannot be collected any more irrespective of the insufficient collection of the waste ink, and the breakdown of the waste ink introducing chamber, the leakage of the waste ink and the damage of the maintenance mechanism might be caused by a rise in a pressure.

In consideration of the problems, it is an object of the invention to provide a liquid housing and a liquid injecting apparatus which can prevent a waste liquid from leaking out depending on an arrangement posture and can maintain an air permeability. In each cartridge described in the JP-A-2003-118144, the volume of a waste liquid reservoir portion is set to be equal irrespective of a difference in an exchange time depending on a difference between the amounts of consumption of various inks. Accordingly, there is a possibility that a cartridge having an early exchange time might be exchanged in a state in which the waste ink filling rate of the waste ink reservoir portion is low. To the contrary, a cartridge having a late exchange time is attached for a long period. For this reason, the waste ink tends to be collected in a large amount. In order to prevent the leakage of the waste ink, therefore, the capacity of the waste ink reservoir portion is set corresponding to the amount of the waste ink collected by the cartridge having the late exchange time. For this reason, the waste ink reservoir portion and the cartridge tend to be large-sized.

The invention has been made in consideration of the problems and has an object to provide a waste liquid collecting method, a liquid injecting apparatus and a cartridge (liquid housing) set which can reduce the size of the apparatus or the cartridge.

Moreover, it is an object of the invention to provide a waste liquid collecting method, a liquid injecting apparatus and a cartridge (liquid housing) set which can efficiently store a waste liquid in a plurality of liquid housings.

SUMMARY OF THE INVENTION

The invention provides a liquid housing comprising a liquid housing chamber accommodating a liquid to be supplied to a liquid injecting head and a waste liquid housing chamber accommodating an absorber for accommodating a waste liquid, wherein an air communicating hole for communicating with outside air is provided in the waste liquid housing chamber and the air communicating hole is sealed with an air permeable film.

According to the invention, the air communicating hole provided in the waste liquid housing chamber is sealed with the air permeable film. Therefore, the waste liquid can be prevented from leaking out of the air communicating hole. Moreover, the film sealing the air communicating hole is the air permeable film. When the waste liquid is introduced into the waste liquid housing chamber, therefore, a gas comes out of the air permeable film. Consequently, the waste liquid is smoothly introduced into the waste liquid housing chamber. Furthermore, the absorber accommodated in the waste liquid housing chamber absorbs and holds the waste liquid. Even if the posture of the liquid housing is changed, therefore, the waste liquid sticks to the air permeable film irrespective of a small amount of the waste liquid accommodated in the waste liquid housing chamber, and the air permeable film can be prevented from being unused, for example.

In the liquid housing according to the invention, the air permeable film is a liquid repellent air permeable film.

According to the invention, since the air permeable film is the liquid repellent air permeable film and repels the waste liquid because of the liquid repellency, the waste liquid sticks thereto with difficulty. Accordingly, the waste liquid can be prevented from sticking to the liquid repellent air permeable film to cause clogging, resulting in a deterioration in the air permeability.

In the liquid housing according to the invention, the liquid housing chamber accommodates a liquid in an accommodating state in a liquid housing bag.

According to the invention, the liquid in the accommodating state in the liquid housing bag is accommodated in the liquid housing chamber. For this reason, the liquid can be accommodated in a state in which a degree of deaeration is higher as compared with the case in which the liquid is not accommodated in the liquid housing bag but is directly accommodated in the liquid housing chamber, for example.

The liquid housing according to the invention comprises a vessel body and a cover member for blocking the vessel body, and the waste liquid housing chamber is divided by blocking the opening portion of the vessel body or the cover member with a film member.

According to the invention, the waste liquid housing chamber can easily be formed. Therefore, the waste liquid housing chamber can be formed at a low cost.

In the liquid housing according to the invention, the air communicating hole is formed on the cover member.

According to the invention, the air communicating hole is formed on the cover member. Therefore, air in the waste liquid housing chamber can easily be discharged to the outside of the liquid housing.

In the liquid housing according to the invention the air communicating hole is formed on the film member.

According to the invention, the air communicating hole is formed on the film member. Also when using a cover member having no air communicating hole formed thereon, for example, it is possible to discharge the air in the waste liquid housing chamber to the outside by means of the film member. Therefore, the waste liquid can be smoothly introduced into the waste liquid housing chamber.

The liquid housing according to the invention comprises a waste liquid introducing portion having a liquid flow path connected to the waste liquid housing chamber and causing the outer portion of the waste liquid housing chamber to communicate with the inner portion of the waste liquid housing chamber, and the waste liquid introducing portion is provided with a seal member capable of inserting a hollow needle for introducing a waste liquid into the waste liquid housing chamber.

According to the invention, the waste liquid introducing portion is provided with a seal member capable of inserting a hollow needle for introducing a waste liquid into the waste liquid housing chamber. Therefore, the sealing property of the waste liquid introducing portion and the hollow needle can be enhanced so that their connection can be carried out reliably.

In the liquid housing according to the invention, a valve mechanism for preventing a waste liquid from flowing out of the waste liquid introducing portion without the hollow needle inserted is provided on the inside of the waste liquid introducing portion.

According to the invention, a valve mechanism for preventing a waste liquid from flowing out of the waste liquid introducing portion without the hollow needle inserted is provided on the inside of the waste liquid introducing portion. When the hollow needle is not inserted into the waste liquid introducing portion, therefore, it is possible to prevent the waste liquid from leaking out of the waste liquid introducing portion.

A liquid injecting apparatus according to the invention comprises the liquid housing described above, and a liquid injecting head having a plurality of nozzles for discharging a liquid, a liquid supply tube connected to the liquid housing chamber, and a waste liquid tube connected to the waste liquid housing chamber, and the liquid is supplied from the liquid housing chamber to the liquid injecting head through the liquid supply tube, and furthermore, the liquid sucked from the liquid injecting head is discharged to the waste liquid housing chamber through the waste liquid tube.

According to the invention, it is possible to prevent the waste liquid from leaking out depending on the arrangement posture of the liquid injecting apparatus.

A liquid injecting apparatus according to the invention comprises a plurality of liquid housings described above, and a liquid injecting head having a plurality of nozzles for discharging a liquid, a plurality of liquid supply tubes connected to the liquid housing chambers, and a plurality of waste liquid tubes connected to the waste liquid housing chambers, and the liquid is supplied from the liquid housing chambers to the liquid injecting head through the liquid supply tubes respectively, and furthermore, the liquid sucked from the liquid injecting head is discharged to the waste liquid housing chambers through the waste liquid tubes.

According to the invention, the liquid is supplied from the liquid housing chambers to the recording head through the liquid supply tubes, and furthermore, the liquid sucked from the recording head is discharged to the waste liquid housing chambers through the waste liquid tubes. Therefore, the amount of the waste liquid which can be collected can be more increased as compared with the case in which the waste liquid housing chamber is provided in any of the liquid housings, for example. Furthermore, the waste liquid is collected into the waste liquid housing chamber in order from the lowest flow path resistance of the waste liquid tube connected to the waste liquid housing chamber, for example. As a result, the liquid injecting apparatus does not need to control the collection of the waste liquid in any of the liquid housings. Consequently, it is possible to reduce a time required for a liquid injection processing.

The invention provides a method of collecting a waste liquid in a liquid injecting apparatus comprising a liquid injecting head for discharging a liquid and a maintenance mechanism for sucking the liquid in the liquid injecting head, wherein there are provided a waste liquid reservoir portion for storing a waste liquid discharged from the maintenance mechanism in a plurality of cartridges for storing a liquid to be supplied to the liquid injecting head, an introducing portion for introducing the waste liquid into the waste liquid reservoir portion, and an open hole for discharging a gas in the waste liquid reservoir portion to an outside, and the flow path resistance of a cartridge side flow path from the introducing portion provided in any of the cartridges which has a large amount of consumption of the liquid to the open hole through the waste liquid reservoir portion is reduced and the amount of the waste liquid introduced in the waste liquid reservoir portion is set to be larger than that of the cartridge.

Consequently, the cartridge is provided with a cartridge side flow path constituted by the introducing portion, the waste liquid reservoir portion and the open hole. Moreover, the cartridge side flow path provided on the cartridge having a large amount of consumption of the liquid is formed in such a manner that a flow path resistance thereof is lower than that of each of the other cartridges.

Accordingly, the waste liquid discharged from the maintenance mechanism is easily introduced into the cartridge on the cartridge side flow path which has a low flow path resistance. As a result, the waste liquid filling rate of the cartridge is increased. More specifically, a waste liquid reservoir portion having a high waste liquid filling rate can be exchanged simultaneously with the exchange of a cartridge having a large amount of consumption of a liquid and an early exchange time. In other words, the waste liquid can be often discarded in a comparatively large amount. Therefore, the amount of the waste liquid to be stored in the waste liquid reservoir portion of each of the cartridges is lessened so that the capacity of the waste liquid reservoir portion can be reduced. Thus, the size of the cartridge can be reduced. Moreover, it is possible to vary the waste liquid filling rate of the cartridge with a simple structure without providing a control valve for controlling the flow of the waste liquid. Furthermore, the resistance of the flow path provided in the cartridge is varied. Consequently, it is possible to vary the waste liquid fling rate of each of the cartridges without changing the structure and layout of each member on the liquid injecting apparatus side.

The invention provides a liquid injecting apparatus comprising a liquid injecting head for discharging a liquid and a maintenance mechanism for sucking the liquid in the liquid injecting head, wherein a plurality of cartridges for storing a liquid to be supplied to the liquid injecting head includes a waste liquid reservoir portion for storing a waste liquid discharged from the maintenance mechanism respectively, and furthermore, flow path resistances of cartridge side flow paths from an introducing portion for introducing the waste liquid to an open hole for discharging a gas in the waste liquid reservoir portion to an outside through the waste liquid reservoir portion are different from each other.

Consequently, the cartridge side flow path constituted by the introducing portion, the waste liquid reservoir portion and the open hole is provided in the cartridge mounted on the liquid ejecting apparatus. Moreover, the cartridge side flow paths are formed in such a manner that the flow path resistances are different from each other. Accordingly, the waste liquid is easily introduced from the maintenance mechanism into the cartridge having a low flow path resistance of the cartridge side flow path so that the waste liquid filling rate can be increased. Therefore, when the flow path resistance of the cartridge side flow path of the cartridge having a large amount of consumption of the liquid and an early exchange time is reduced, for example, the waste liquid reservoir portion having a high waste liquid filling rate can be exchanged simultaneously with the exchange of the cartridge. In other words, the waste liquid can be often discarded in a comparatively large amount. Even if the capacity of each waste liquid reservoir portion is reduced, therefore, the waste liquid can be collected without a leakage. Accordingly, the sizes of the waste liquid reservoir portion and the cartridge can be reduced. Moreover, it is possible to vary the waste liquid filling rate of the cartridge with a simple structure without providing a control valve for controlling the flow of the waste liquid. Furthermore, the resistance of the flow path provided in the cartridge is varied. Consequently, it is possible to vary the waste liquid filling rate of each of the cartridges without changing the structure and layout of each member on the liquid ejecting apparatus side.

In the liquid injecting apparatus, the flow path sectional areas or flow path lengths of at least a part of the cartridge side flow paths provided in the cartridges are caused to be different from each other so that the flow path resistances of the cartridge side flow paths are caused to be different from each other.

Consequently, the flow path sectional areas or flow path lengths of at least a part of the cartridge side flow paths are different from each other so that the flow path resistances of the cartridge side flow paths are different from each other. More specifically, when the flow path sectional area is large or the flow path length is small, the flow path resistance is low. For this reason, it is possible to easily change the flow path resistances of the cartridge side flow paths by setting the cartridges to have almost the same structures.

In the liquid injecting apparatus, the flow path sectional areas or the flow path lengths from the introducing portions to the waste liquid reservoir portions in the cartridge side flow paths are different from each other.

Consequently, the flow path sectional areas or the flow path lengths from the waste liquid introducing ports to the waste liquid reservoir portions in the cartridge side flow paths are different from each other so that the flow path resistances are different from each other. Therefore, the structure of the flow path through which the waste liquid passes is varied depending on the cartridge. Consequently, it is possible to vary the flow path resistance reliably.

In the liquid injecting apparatus, the air permeabilities of the air permeable films provided in the cartridges to block the open holes are caused to be different from each other so that the flow path resistances of the cartridge side flow paths are caused to be different from each other.

Consequently, the flow-path resistance of each cartridge side flow path is varied by changing an air permeable amount (air permeability) per unit time of the air permeable film. Therefore, it is possible to easily vary the flow path resistance without changing the size or structure of the cartridge.

In the liquid injecting apparatus, the air permeable areas of the air permeable films are caused to be different from each other.

Consequently, the air permeable areas of the air permeable films are caused to be different from each other. Thus, the air permeabilities of the air permeable films are caused to be different from each other. More specifically, in the case in which the air permeable area of the air permeable film is large, a contact area with a gas in the waste liquid reservoir portion is increased. Therefore, the air permeability is great and the flow path resistance of the cartridge side flow path is low. Thus, it is possible to easily vary the flow path resistance without changing the size or structure of the cartridge.

In the liquid injecting apparatus, the thicknesses of the air permeable films are caused to be different from each other.

Consequently, the thicknesses of the air permeable films are caused to be different from each other. Thus, the air permeabilities of the air permeable films are caused to be different from each other. More specifically, in the case in which the thickness of the air permeable film is small, the air permeability is great and the flow path resistance of the cartridge side flow path is low. Thus, it is possible to easily vary the flow path resistance without changing the size or structure of the cartridge.

In the liquid injecting apparatus, the materials of the air permeable films are caused to be different from each other. Thus, the air permeabilities of the air permeable films are caused to be different from each other.

Consequently, the materials of the air permeable films are caused to be different from each other so that the air permeabilities of the air permeable films are different from each other. More specifically, in the case in which the air permeable film is formed by a material having a great air permeability, the flow path resistance of the cartridge side flow path is low. Therefore, it is possible to easily vary the flow path resistance without changing the size or structure of the cartridge.

In the liquid injecting apparatus, an exhaust flow path communicating with the waste liquid reservoir portion is provided in case of the cartridge and a plurality of air communicating portions which can be opened to the air in use is formed in the middle of the exhaust flow path. The air communicating portions are provided in such a manner that flow path lengths or flow path sectional areas from the waste reservoir portions to the air communicating portions are different from each other.

Consequently, the exhaust flow path communicating with the waste liquid reservoir portion is provided in case of the cartridge. Moreover, a plurality of air communicating portions which can be opened to the air in use is provided in the middle of the exhaust flow path. Furthermore, the air communicating portions are provided in such a manner that flow path lengths or flow path sectional areas from the waste liquid reservoir portions are different from each other. More specifically, in the case in which the air communicating portion which is comparatively close to the waste liquid reservoir portion is opened to the air, the flow path length from the waste liquid reservoir portion to the air communicating portion is reduced. Consequently, the flow path resistance is decreased. In the case in which the air communicating portion which is comparatively distant from the waste liquid reservoir portion is opened to the air, moreover, the flow path length from the waste liquid reservoir portion to the air communicating portion is increased. Consequently, the flow path resistance is increased. For this reason, in the case in which the exchange time of the cartridge is varied depending on the situation of use or the individual difference of an apparatus, for example, the flow path resistance of the cartridge can be changed properly.

The invention provides a cartridge set comprising a plurality of cartridges including a liquid reservoir portion for accommodating a liquid and a waste liquid reservoir portion for accommodating a waste liquid, wherein flow path resistances of cartridge side flow paths reaching open holes for discharging a gas in the waste liquid reservoir portion to an outside from introducing portions formed on the cartridges through the waste liquid reservoir portions are set to be different from each other depending on the amount of consumption of the liquid in each of the cartridges.

Consequently, each cartridge having the liquid reservoir portion and the waste liquid reservoir portion has the flow path resistance of the cartridge side flow path varied depending on the amount of consumption of the liquid. For this reason, the waste liquid can easily be introduced into the cartridge having a low flow path resistance so that the waste liquid filling rate of the cartridge can be increased. More specifically, it is possible to exchange the waste liquid reservoir portion having a high waste liquid filing rate simultaneously with the exchange of the cartridge having a large amount of consumption of a liquid and an early exchange time. In other words, the waste liquid can be often discarded in a comparatively large amount. Therefore, the amount of the waste liquid to be stored in the waste liquid reservoir portion of each of the cartridges is lessened so that the capacity of the waste liquid reservoir portion can be decreased. Consequently, the size of the cartridge can be reduced.

The present disclosure relates to the subject matter contained in Japanese patent application No. 2004-074982 (filed on Mar. 16, 2004) and 2004-217611 filed on Jul. 26, 2004), each of which is expressly incorporated herein by reference in its entirety.

DESCRIPTION OF THE PREFERRED EMBODIMENT

First Embodiment

A first embodiment carrying out the invention will be described below with reference toFIGS. 1 to 6.

FIG. 1is a conceptual view showing a printer according to the embodiment.

As shown inFIG. 1, a printer1to be a liquid injecting apparatus comprises a cover2, and a cartridge holder3is formed in the lower part of the cover2. An ink cartridge C to be a liquid housing is removably provided in the cartridge holder3. The ink cartridge C can accommodate an ink to be a liquid, and furthermore, can store a waste ink to be a waste liquid, details of which will be described below.

The printer1comprises a guide member9, and the guide member9is provided over a pair of frames in the cover2. A carriage6is inserted in and supported on the guide member9movably in the axial direction of the guide member9. The carriage6is connected to a carriage motor (not shown) through a timing belt (not shown) and is reciprocated along the guide member9by the driving operation of the carriage motor.

A recording head10to be a liquid injecting head is provided on the lower surface of the carriage6, and furthermore, a subtank11is mounted on the carriage6. The subtank11is provided with a differential pressure regulating valve mechanism disclosed in EP1016533 and EP1398156. The subtank11is connected to the ink cartridge C through an ink supply tube7to be a liquid supply tube.

Moreover, the subtank11is connected to the recording head10and temporarily stores an ink supplied from the ink cartridge C, and supplies the ink to the recording head10with a pressure regulated. The recording head10includes, in a lower surface thereof, a nozzle which is not shown, and discharges, from the nozzle, the ink supplied from the subtank11by the driving operation of a piezoelectric unit which is not shown. At the same time that the ink is discharged from the nozzle, the carriage6is reciprocated with respect to a recording medium (not shown) to be a target so that printing can be carried out over the recording medium.

On the other hand, a maintenance mechanism15is provided in a non-printing region (a home position) placed on the right side of the cartridge holder3over the moving path of the carriage6. As shown inFIG. 1, the maintenance mechanism15includes a cap16taking the shape of an almost square frame, and a sucking pump19. While the sucking pump19is constituted by a tube pump in the example, another structure may be employed. The cap16can be moved vertically by well-known up-down means which is not shown. When the cap16is lifted, it abuts on the recording head10, thereby sealing the nozzle of the recording head10. Moreover, the cap16has a bottom portion to which a sheet-shaped sponge (not shown) is fastened. The sponge is opposed to the nozzle of the recording head10at a predetermined interval in the state in which the cap16abuts on the recording head10, thereby receiving the ink discharged from the nozzle of the recording head10. Furthermore, a discharge port is formed on the center of the cap16to penetrate through a bottom surface thereof.

A discharge flow path18formed by a waste liquid tube (a waste ink tube) has one of ends which is connected to the discharge port of the cap16and the other end which is connected to the ink cartridge C. The sucking pump19formed by a tube pump presses the waste ink tube18in a state in which the nozzle of the recording head10is sealed with the cap16, thereby reducing a pressure in the cap16to suck the ink from the recording head10and to discharge the ink to the ink cartridge C.

Next, description will be given to the ink cartridge C.

As shown inFIG. 2, the ink cartridge C takes the shape of an almost rectangular parallelepiped. As shown inFIG. 3, the ink cartridge C includes an upper cover33to be a cover member, an air permeable or liquid repellent air permeable film47, a waste ink absorber48to be an absorbing member, a film49to be a film member, an ink pack30to be a liquid housing bag, and a lower cover25to be a vessel body. The upper cover33has a rectangular plate-shaped portion34and an internal frame portion35erected at a right angle like a frame from the plate-shaped portion34in an inside position from the peripheral edge of the plate-shaped portion34. The internal frame portion35has four side surfaces, that is, a first side surface (a front wall portion)35a, a second side surface (a left wall portion)35b, a third side surface (a right wall portion)35c, and a fourth side surface (a back wall portion)35d.

As shown inFIG. 4, a through hole36for causing the inside and outside of the first side surface35ato communicate with each other is provided in the vicinity of a first corner portion35acformed by the first side surface35aand the third side surface35cin the internal frame portion35. Moreover, a cylindrical waste liquid introducing portion37is protruded from the outside surface of the first side surface35ato surround the through hole36.

As shown inFIG. 5, a communicating hole38to be a liquid flow path is formed to penetrate through the waste liquid introducing portion37. The communicating hole38communicates with the through hole36. The communicating hole38is provided with a plurality of communicating grooves38bon an inner peripheral surface38a. The inner peripheral surface38ais formed with a section taking an almost circular shape. The inner peripheral surface38ais concaved to provide the communicating groove38b. Herein, the communicating groove38bis formed in two places of the inner peripheral surface38a.

Moreover, a valve mechanism V is provided in the waste liquid introducing portion87. The valve mechanism V includes a valve member39and a seal member (a valve seat)40. The outside diameter of the valve member39is almost equal to the inside diameter of the inner peripheral surface38a, and the inner peripheral surface38ais provided slidably in the axial direction.

The seal member40is formed by a flexible material such as elastomer and is provided almost cylindrically. An insertion hole40apenetrating through the center of the seal member40has an inside diameter on the valve member39side at which a waste liquid needle (not shown) to be a hollow needle provided in the waste ink tube18is close fitted, and is formed to be expanded and opened toward an introducing side (an outside). A valve seat portion44is protruded from a base end face40bof the seal member40in order to surround the opening of the insertion hole40a. The valve member39is seated on the valve seat portion44so that the insertion hole40aof the seal member40is closed by the valve member39. The waste liquid needle is formed to be hollow and the waste ink is caused to flow out through the hole.

Furthermore, the valve mechanism V includes a coiled spring41for energizing the valve member39. The coiled spring41is supported and fixed into the communicating hole38in order to energize the valve member39toward the seal member40side. In the case in which a force is not applied from an outside, the coiled spring41is energized to press the valve member89in contact with the valve seat portion44of the seal member40as shown inFIG. 5. When the waste liquid needle is inserted into the valve member39through the insertion hole40aof the seal member40, the valve member39is moved in such a direction as to separate from the seal member40against the energizing force of the coiled spring41. At this time, the tip of the waste liquid needle is inserted in a sealing state with the seal member40. When the valve member39is separated from the seal member40, moreover, the hole of the waste liquid needle, the communicating hole38on an opposite side with the valve member39interposed therebetween and the communicating groove38bare connected to each other. When the waste ink of the waste liquid needle is introduced into the waste liquid introducing portion87, accordingly, the waste ink is led through the communicating groove38bto the communicating hole88on the coiled spring41side with the valve member39interposed therebetween and flows from the hole of the waste liquid needle into the internal frame portion35.

As shown inFIG. 4, furthermore, the upper cover33includes an almost L-shaped dividing portion42on the inside of the internal frame portion35in parallel with the first side surface35aand the second side surface35b. The height of the dividing portion42is equal to that of the internal frame portion35. Accordingly, a flow path44is formed by a division between the dividing portion42and the first side surface35aand second side surface35b. Moreover, a waste ink reservoir portion45taking the shape of an almost rectangular parallelepiped is formed by a division between the dividing portion42and the third side surface35cand fourth side surface35d.

The dividing portion42has an end42abonded in a close position to the first corner portion35acfrom the position of the through hole36with respect to the first side surface35a. Moreover, the other end42bof the dividing portion42is positioned so as not to come in contact with the internal frame portion35in a second corner portion35bdformed by the second side surface35band the fourth side surface35d. Accordingly, the flow path44communicates with the through hole36in the vicinity of the first corner portion35ac, and furthermore, communicates with the waste ink reservoir portion45in the vicinity of the second corner portion35bdopposed to the first corner portion35ac. As a result, when the waste ink flows into the internal frame portion35via the through hole36, it is moved in the flow path44along the first side surface35aand the second side surface35band flows into the waste ink reservoir portion45in the second corner portion35bd.

Furthermore, an air communicating hole46is formed to penetrate through the upper cover33in a position opposed to the through hole36with the dividing portion42of the waste ink reservoir portion45interposed therebetween. Consequently, air sucked from the recording head10together with the waste ink and discharged to the waste ink reservoir portion45can be discharged to an outside. Moreover, the air communicating hole46is positioned in the most distant place from the second corner portion35bdin the waste ink reservoir portion45.

The square film47is stuck to the air communicating hole46from the inside of the upper cover33as shown inFIG. 3. In the example, the film47has a liquid repellency and an air permeability. Although the liquid repellent air permeable film47prevents the waste ink from passing therethrough, accordingly, the air sucked from the recording head10together with the waste ink can be discharged to the outside of the ink cartridge C. In addition, the film47has a liquid repellency, and therefore, the waste ink is repelled and thus sticks thereto with difficulty.

The waste ink absorber48is formed by a porous material, and takes the shape of an almost rectangular parallelepiped and has such a thickness and width as to be exactly fitted in the waste ink reservoir portion45of the upper cover33as shown inFIG. 3. The waste ink absorber48is formed to have such a length as not to overlap with the film47. As shown inFIG. 4, the waste ink absorber48is accommodated in the waste ink reservoir portion45.

As shown inFIG. 3, the film49takes a rectangular shape and is formed by a double film such as polystyrene and nylon in the case in which the upper cover33is polystyrene, for example. The film49has a peripheral edge portion welded thermally to the internal frame portion35so that the inside of the internal frame portion35is sealed. The film49is also welded thermally to the dividing portion42. As shown inFIG. 6, accordingly, the opening of a groove-shaped space between the internal frame portion35and the dividing portion42is sealed with the film49so that the flow path44is formed. Moreover, the waste ink reservoir portion45has the opening sealed with the film49in a state in which the waste ink absorbent48is accommodated so that a waste ink reservoir chamber S2to be a waste liquid housing chamber is formed.

As shown inFIG. 3, the ink pack30includes an ink bag31and an ink outlet32. The ink bag31is formed by a flexible material and is constituted by an aluminum laminate film having a structure in which an outside is interposed by a nylon film and an inside is interposed by a polyethylene film in order to enhance a gas barrier property, for example. The ink bag31is formed by superposing two aluminum laminate films taking an almost rectangular shape and bonding their peripheries by a method of thermal welding, and accommodates a deaerated ink therein.

The ink outlet32includes a cylinder portion formed of plastic constituted by the same material as the inner film of the ink bag31, for example. The cylinder portion is attached to a part of the bonding portion of the two aluminum laminate films of the ink bag31by the method of thermal welding, and is fixed in such a manner that the ink in the ink bag31can be led to an outside. Moreover, the ink outlet32includes a valve mechanism (not shown) therein. The valve mechanism has the same structure as the valve mechanism V provided in the waste liquid introducing portion37.

The lower cover25is box-shaped in which an upper side taking the shape of an almost rectangular parallelepiped is opened, and has such a size that the internal frame portion35of the upper cover33can be inserted therein. A side surface (front wall portion)25ais provided with a lead-out portion26and a lead-in portion27. The lead-out portion26and the lead-in portion27are formed as a first protrusion and a second protrusion which are outward protruded from the font wall portion25a. The first and second protrusions have lower parts taking the shape of a circular arc, respectively.

The ink outlet32of the ink pack30can be fitted in the lead-out portion26, and the ink pack30is accommodated in the lower cover25by fitting the ink outlet32in the lead-out portion26. Moreover, a hole28is formed to penetrate through the lead-out portion26in an opposed position to the ink outlet32of the ink pack30.

Moreover, the waste liquid introducing portion37of the upper cover33can be fitted in the lead-in portion27and the waste liquid introducing portion37of the upper cover33is fitted in the lead in portion27so that the opening of the lower cover25is sealed. Moreover, a hole29is formed to penetrate through the lead-in portion27in an opposed position to the waste liquid introducing portion37of the upper cover33.

When the ink cartridge C is assembled as shown inFIGS. 3 and 6, accordingly, the ink pack30is first accommodated in the lower cover25. Then, the film47is stuck to the air communicating hole46to accommodate the waste ink absorber48in the upper cover33, thereby sealing an opening to be the opening portion of the upper cover33with the film49. The upper cover33is inserted into the lower cover25, thereby sealing the opening of the lower cover25. The opening of the lower cover26is sealed with the upper cover33so that an ink housing chamber S1to be a liquid housing chamber is formed. Therefore, the ink pack30is accommodated in the ink housing chamber S1. The lower cover25is provided with an air communicating hole or an air communicating path (not shown) which serves to cause the ink housing chamber S1to communicate with the air.

The ink supply tube7is connected through the hole28to the ink pack30of the ink cartridge C. In detail, the ink supply tube7includes a hollow ink supply needle (not shown) on an end thereof, and the ink supply needle opens the valve mechanism provided in the ink outlet32of the ink pack30so that the ink pack30and the ink supply tube7are connected to each other.

Moreover, the waste liquid introducing portion37of the ink cartridge C is connected to the waste ink tube (discharge flow path)18through the hole29. In detail, the hollow waste liquid needle (not shown) provided on the end of the waste ink tube18opens the valve mechanism V provided in the waste liquid introducing portion37to communicate with the flow path44. Consequently, the waste ink absorber48and the waste ink tube18are connected to each other.

Next, description will be given to the function of the printer1constituted as described above.

It is assumed that the printer1is carried or brought down so that the posture of the ink cartridge C is changed. At this time, even if the waste ink is sucked into the waste ink reservoir chamber S2through the flow path44, the waste ink is absorbed and held by the waste ink absorber48in which the upper cover33is fitted. Therefore, the waste ink does not flow into the space of the waste ink reservoir chamber S2, that is, the space facing the air communicating hole46. Accordingly, the waste ink can be prevented from flowing into the space to adhere to the film47stuck to the air communicating hole46until the waste ink absorber48is sufficiently filled with the waste ink.

Moreover, the air communicating hole46is positioned in the most distant place from the second corner portion35bdin the upper cover83. Also when the waste ink is sucked from the flow path44and is absorbed and held in the waste ink absorber48, consequently, the waste ink is not soaked out to the vicinity of the film47before the waste ink is absorbed and held in a maximum amount in which the waste ink absorber48can be absorbed and held. Accordingly, the waste ink sticks to the film47with difficulty.

Furthermore, the air communicating hole46is sealed with the liquid repellent air permeable film47. Even if the waste ink absorber48absorbs and holds the waste ink in a maximum amount which can be absorbed and held. Even if the waste ink is soaked out of the waste ink absorber48, the waste ink can be prevented from leaking out of the ink cartridge C through the air communicating hole46. In addition, the liquid repellent air permeable film47repels the waste ink so that the waste ink sticks thereto with difficulty. As a result, it is possible to prevent a liquid repellent air permeable film F from being clogged with the waste ink, resulting in a deterioration in the air permeability.

According to the embodiment, it is possible to obtain the following advantages.

(1) In the embodiment, the air communicating hole46is provided in the distant place from the second corner portion35bdof the upper cover33of the ink cartridge C, that is, the opposed place to the through hole36with the end42aof the dividing portion42interposed therebetween, and the film47is stuck to the air communicating hole46. The waste ink absorber48is fitted in the upper cover33. As a result, when the printer1is carried or brought down so that the posture of the ink cartridge C is changed, the waste ink is absorbed and held by the waste ink absorber48even if the waste ink is sucked from the flow path44. When the waste ink is not sufficiently collected into the waste ink reservoir chamber S2, accordingly, it can be prevented from reaching the film47stuck to the air communicating hole46to deteriorate the air permeability of the film47.

(2) In the embodiment, the air communicating hole46is positioned in the most distant place from the second corner portion35bdin the upper cover33. Also when the waste ink is sucked from the flow path44by a change in the posture of the ink cartridge C and is absorbed and held in the waste ink absorber48, consequently, the waste ink is not soaked out to the vicinity of the film47until the waste ink is absorbed and held in the maximum amount in which the waste ink can be absorbed and held by the waste ink absorber48. Accordingly, the waste ink can be prevented from reaching the film47to deteriorate the air permeability of the film47.

(3) In the embodiment, the air communicating hole46is provided in the opposed place to the second corner portion35bdof the upper cover33of the ink cartridge C, that is, the opposed peace to the through hole36with the end42aof the dividing portion42interposed therebetween, and the liquid repellent air permeable film47is stuck to the air communicating hole46. As a result, the waste ink absorber48absorbs and holds the waste ink in a maximum amount which can be absorbed and held, and the waste ink can be prevented from leaking out of the air communicating hole46even if it is soaked out of the waste ink absorber48. When the waste ink is introduced into the waste ink reservoir chamber S2, moreover, the air comes out of the liquid repellent air permeable film47. Therefore, the waste ink is smoothly introduced into the waste ink reservoir chamber S2. In addition, the liquid repellent air permeable film47repels the waste ink, and therefore, the waste ink sticks thereto with difficulty. Consequently, the liquid repellent air permeable film47can be prevented from being clogged with the waste ink to deteriorate the air permeability.

Second Embodiment

Next, a second embodiment carrying out the invention will be described with reference toFIG. 7. One of features according to the embodiment is that a plurality of ink cartridges C described in the first embodiment is connected. In the following embodiment, the same portions as those in the first embodiment have the same reference numerals and detailed description thereof will be omitted.

FIG. 7is a conceptual view showing a waste liquid collecting system in which a plurality of ink cartridges is connected.

In the embodiment, the waste liquid collecting system comprises ink cartridges C1, C2, C3, C4, C5and C6corresponding to six ink colors (black, cyan, magenta, yellow, light cyan and light magenta), for example. Moreover, the waste liquid collecting system comprises a maintenance mechanism15. In the case in which the description is to be given without the distinction of these ink cartridges C1to C6from each other, they will be hereinafter referred to as a cartridge C in the same manner as in the first embodiment.

The ink cartridges C1, C2, C3, C4, C5and C6are provided in this order from a close side to a sucking pump19, for example. Waste liquid introducing portions37of the respective ink cartridges C1to C6are connected to each other through a waste ink tube (a discharge flow path)18, and furthermore, are connected to the pump19through the waste ink tube18. More specifically, the six ink cartridges C1to C6are connected to the pump19in parallel.

In the waste ink tubes18connected to the ink cartridges C1to C6, moreover, flow path sectional areas are equal to each other and only path lengths from the pump19are different from each other. Air communicating holes46of the ink cartridges C1to C6are not connected to each other but communicate with the outside air independent of each other. Moreover, ink outlets32of the ink cartridges C1to C6are connected to each other but are connected to ink supply tubes7corresponding thereto. An air permeable film47, preferably, a liquid repellent air permeable film47is stuck to each of the air communicating holes46of the ink cartridges CL to C6.

Next, description will be given to the function of the waste liquid collecting system thus constituted.

When the maintenance mechanism15of a printer1first carries out a cleaning operation, an ink sucked into the pump19is discharged to the waste liquid introducing portion37of the ink cartridge C1which is the closest to the pump19and has the smallest flow path length of the waste ink tube18, that is, the lowest flow path resistance of the waste ink tube18through the waste ink tube18. It is assumed that the cleaning is carried out many times and the waste ink is absorbed and held in a maximum amount which can be absorbed and held by a waste ink absorber48provided in the ink cartridge C1.

When the ink cartridge C1which is the closest to the pump19is filled with a waste ink, the waste ink discharged from the maintenance mechanism15is discharged to the waste liquid introducing portion37of the ink cartridge C2having the second smallest flow path length and flow path resistance of the waste ink tube18to the ink cartridge C1. The waste ink is discharged to the ink cartridge C2as described above until the waste ink absorber48of the ink cartridge C2is filled with the waste ink.

Similarly, the waste ink discharged from the maintenance mechanism15is discharged to the ink cartridge C3having the second smallest flow path length and flow path resistance of the waste ink tube18to the ink cartridge C2. Thus, the waste ink is collected in order of the ink cartridges C4, C5and C6.

Consequently, it is possible to more increase the amount of the waste ink which can be collected as compared with the case in which a waste ink reservoir chamber S2is provided in only one of the ink cartridges C1to C6corresponding to the inks having the six colors, for example. Moreover, the waste ink is collected into each of the ink cartridges C in ascending order from the flow path resistance of the waste ink tube18connected to the ink cartridge C. Therefore, the printer1does not need to carry out a control for collecting the waste ink by the waste ink reservoir chamber S2of the ink cartridge C accommodating an ink having any color. Accordingly, it is possible to reduce a time required for the print processing of the printer1.

By more reducing the flow path resistance of the waste ink tube18connected to the ink cartridge C having a higher exchange frequency, moreover, it is possible to collect the waste ink into the ink cartridge C having a higher exchange frequency with more priority. Accordingly, it is possible to efficiently collect the waste ink even if the volume of the waste ink reservoir chamber S2of each of the ink cartridges C is decreased.

According to the embodiment, it is possible to obtain the following advantages in addition to the advantages of the first embodiment.

(1) In the embodiment, the six ink cartridges C1to C6are connected to the pump19through the waste ink tube18in parallel. For example, therefore, it is possible to more increase the amount of the waste ink which can be collected as compared with the case in which the waste ink reservoir chamber S2is provided in one of the ink cartridges C.

(2) In the embodiment, the six ink cartridges C1to C6are connected to the pump19through the waste ink tube18in parallel. Therefore, the waste ink is collected into each of the ink cartridges C1to C6in ascending order of the flow path resistance of the waste ink tube18connected to the ink cartridges C1to C6. As a result, the printer1does not need to carry out a control for collecting the waste ink into the ink cartridges C1to C6accommodating the inks having the respective colors. Accordingly, it is possible to reduce a time required for the print processing of the printer1.

(3) By more reducing the flow path resistance of the waste ink tube18connected To the ink cartridge C having a higher exchange frequency, it is possible to collect the waste ink into the ink cartridge C having a higher exchange frequency with more priority. Accordingly, it is possible to efficiently collect the waste ink even if the volume of the waste ink reservoir chamber S2of each of the ink cartridges C is decreased.

Third Embodiment

A third embodiment carrying out the invention will be described below with reference toFIGS. 8 to 16.FIG. 8is a perspective view showing a printer1to be a liquid injecting apparatus,FIG. 9is a perspective view showing the main part of the printer1,FIG. 10is a typical view for explaining the cleaning operation of the printer1, andFIG. 11is an explanatory view showing the flow of an ink to be a liquid and a waste ink to be a waste liquid for a cartridge C. The same portions as those in the first and second embodiments have the same reference numerals and detailed description thereof will be omitted. One of features according to the embodiment is that a flow path resistance to the waste liquid in at least one of the ink cartridges C attached to the printer1is set to be lower than a flow path resistance for the waste liquid in another ink cartridge.

As shown inFIG. 8, the printer1comprises a cartridge holder3on the upper surface of a cover2. First to fourth cartridges C1to C4are removably attached to the cartridge holder3, respectively. The first to fourth cartridges C1to C4are arranged in the cartridge holder3in a line in order. An elongated connecting portion5is provided adjacently to the cartridge holder3. When the first to fourth cartridges C1to C4are attached to the cartridge holder3, they are connected to a coupling part (not shown) in the connecting portion5.

As shown in a broken line in the first cartridge C1on a right end inFIG. 8, moreover, the first to fourth cartridges C1to C4have a first housing portion S1to be a liquid reservoir portion for accommodating various inks therein. The first cartridge C1accommodates a black ink in the first housing portion S1and the second to fourth cartridges C2to C4accommodate various color inks of cyan, magenta and yellow therein, respectively.

Moreover, the first to fourth cartridges C1to C4include a second housing portion S2capable of accommodating a liquid as shown in a broken line above the first housing portion S1in inner parts thereof A waste ink discharged in the cleaning to be carried out for preventing a printing failure by the printer1is accommodated in the second housing portion S2. In the case in which description is to be given without the distinction of the first to fourth cartridges C1to C4from each other, they will be simply referred to as the cartridge C. Moreover, the first to fourth cartridges C1to C4constitute a cartridge set.

As shown inFIGS. 10 and 11, each supply flow path4for causing each cartridge C to communicate with a carriage6is connected to the cartridge C. The supply flow path4is constituted by a flow path (not shown) which is formed in the connecting portion5and a supply tube7(seeFIG. 9) coupled to the connecting portion5. The supply tube7has one of ends which is connected to the connecting portion5and the other end which is coupled to the carriage6side, and includes four supply flow paths4.

As shown inFIG. 9, the carriage6is inserted in and supported on a guide member9provided across a pair of frames8in the cover2. The carriage6is driven and coupled to a carriage motor (not shown) through a timing belt and is reciprocated in a fast scan direction (an X-axis direction) along the guide member9by the driving operation of the carriage motor.

A recording head10to be a liquid injecting head is provided on the lower surface of the carriage6. The recording head10includes a piezoelectric unit (not shown) and each nozzle N (seeFIG. 3). Moreover, four subtanks11are mounted on the carriage6as shown inFIG. 9and an ink supplied from each cartridge C through the supply flow path4(the connecting portion5and the supply tube1) is temporarily stored in each of the subtanks11. Each of the subtanks11supplies an ink to the recording head10corresponding to the amount of the ink discharged from the recording head10. Accordingly, printing is carried out by alternately repeating an operation for discharging an ink droplet to a paper P (seeFIG. 8) while moving the recording head10in the fast scan direction and an operation for delivering the paper P in a slow scan direction (a Y-axis direction) by means of a paper feeding mechanism which is not shown. In the printer1, moreover, it is assumed to previously know, according to statistics, that the black ink has the largest amount of consumption of an ink (a liquid). For this reason, an exchange time for the first cartridge C1is the earliest.

Moreover, a maintenance mechanism15is provided in the home position of the carriage6shown inFIG. 9in a non-printing region to be a moving path for the carriage6on the outside of a delivery path for the paper P. The maintenance mechanism15includes, in a case15a, a cap16taking the shape of a square frame shown inFIG. 10. The cap16is reciprocated in a vertical direction by an up-down mechanism (not shown) between an acting position abutting on the lower surface of the recording head10shown inFIG. 10and an evacuating position separated from the recording head10. Moreover, a discharge port17is formed to penetrate through the bottom wall of the cap16and a discharge flow path18such as a tube is connected to the discharge port17. The discharge flow path18connects the cap16to the connecting portion5and a sucking pump19is provided in the middle thereof.

In suction cleaning, the cap16is disposed in the acting position and the sucking pump19is driven with the lower surface of the recording head10sealed. Consequently, air and an ink are sucked and discharged from the discharge flow path18and the cap16, and a negative pressure is accumulated in the cap16. By the action of the negative pressure, a thickened ink, dust and air bubbles are discharged from the nozzle N of the recording head10and the lower surface thereof into the cap16.

The ink discharged into the cap16is transmitted by pressure through the sucking pump19to a waste ink flow path20communicating with the discharge flow path18. The waste ink flow path20is formed in the connecting portion5as shown inFIG. 10. Moreover, the waste ink flow path20is formed to branch in the direction of each cartridge C in the middle as shown inFIG. 11. By this structure, the waste ink flowing into the waste ink flow path20is distributed and stored in the second housing portion S2of each cartridge C. Referring to each flow path length from an inlet20aof the waste ink flow path20to the inlet of each cartridge C, moreover, flow path lengths d1 and d2 communicating with the first and second cartridges C1and C2are equal to the path length and flow path lengths d3 and d4 communicating with the third and fourth cartridges C3and C4are greater than the path length (that is, d1=d2<d3<d4).

Next, each cartridge C will be described which reference toFIGS. 12 to 15.FIG. 12is a perspective view showing the cartridge C,FIG. 13is an exploded perspective view showing the cartridge C,FIG. 14is a bottom view showing the upper cover of the cartridge C, andFIG. 15is a cross sectional view showing the cartridge C. The ink cartridge C shown inFIGS. 12 to 15is almost identical to the ink cartridge C shown inFIGS. 2 to 6. Accordingly, description will be given to the ink cartridge C again with reference toFIGS. 12 to 15, and the description related to the ink cartridge C shown inFIGS. 2 to 6can also be applied properly to the description of the ink cartridge C shown inFIGS. 12 to 15.

As shown inFIG. 12, the cartridge C includes a case CS taking the shape of an almost rectangular parallelepiped and the case CS has a lower cover25. The lower cover25is formed to take the shape of a box with an upper side opened. A front wall portion25aof the lower cover25is provided with a lead-out portion26and a lead-in portion27which have holes28and29on almost centers thereof in order to penetrate through the front wall portion25a. Moreover, the lead-in portion27is provided above the lead-out portion26in the front wall portion25a.

An ink pack80shown inFIG. 13is accommodated in the lower cover25. The ink pack30includes an ink bag31and an outlet32. The ink bag31is formed by a film constituted by a flexible material. The outlet32has such a structure that one of ends is protruded from the ink bag31and the other end is inserted and fixed into the ink bag31, and an ink in the ink bag31is led out. When the ink pack30is to be accommodated in the lower cover25, the outlet32is engaged from the inside of the lead-out portion26in such a manner that an ink needle (not shown) can be inserted into the outlet32through the hole28of the lead-out portion26.

An upper cover33constituting a case is fixed to the lower cover25accommodating the ink pack30therein. The upper cover33includes a rectangular plate-shaped portion34and an internal frame portion35erected like a frame at the lower surface of the plate-shaped portion34as shown inFIG. 13. The internal frame portion35has a front wall portion35a, a left wall portion35b, a right wall portion35cand a back wall portion35d.

As shown inFIG. 14, a through hole36for causing the inside and outside of the front wall portion35ato communicate with each other is formed in the position of the front wall portion35awhich is close to the right wall portion35c. The through hole36is formed in a waste ink introducing portion37to be a lead-in portion which is provided to be continuously linked to the front wall portion35aof the internal frame portion35. The waste ink introducing portion37is provided with a valve mechanism including a valve member39, a valve seat40, and an energizing spring41for energizing the valve member39toward the valve seat40. A waste liquid needle N2(seeFIG. 11) provided on the tip of the connecting portion5is inserted into the inserting port of the waste ink introducing portion37. When the waste liquid needle N2is inserted, the valve member39is separated from the valve seat40against the energizing force of the energizing spring41. Consequently, the inside and outside of the internal frame portion35are caused to communicate with each other via the through hole36.

As shown inFIGS. 13 and 14, moreover, an almost L-shaped dividing portion42is erected on the inside of the internal frame portion35in the plate-shaped portion34. The dividing portion42is provided in almost parallel with the front wall portion35aand the left wall portion35D, and a rear end thereof is formed to be expanded and opened with the back wall portion35d. Moreover, the front end of the dividing portion42is formed to be continuously linked with the front wall portion35ato surround the through hole36. As a result, the inner part of the internal frame portion35is divided into a flow path44and a waste ink reservoir portion45to be a waste liquid reservoir portion through the dividing portion42. The flow path44is formed like a groove between the dividing portion42and the front wall portion35aand left wall portion35b, and is bent at the front and left corner portion of the upper cover33with the through hole36side to be a starting end and is extended along the left wall portion35b. Moreover, the waste ink reservoir portion45is a space provided between the dividing portion42and the right wall portion85cand back wall portion35d, and the flow path44and the waste ink reservoir portion45are caused to communicate with each other through an enlarging and opening portion44abetween the dividing portion42and the back wall portion85d.

As shown inFIG. 13, moreover, an air communicating hole46to be an open hole is formed to penetrate through the plate-shaped portion34in a position corresponding to the front and right corner portion of the waste ink reservoir portion45. The air communicating hole46is blocked by sticking a rectangular air permeable film47to the lower surface of the plate-shaped portion34as shown inFIG. 14. In the example, the film47may have only an air permeability but it is preferable that the film47should have both the air permeability and a liquid repellency. As shown in a broken line ofFIG. 14, moreover, only an edge47aof the air permeable film47is stuck to the plate-shaped portion34and a clearance is provided between the air permeable film47and the plate-shaped portion34. As described above, moreover, the air permeable film47has at least the air permeability. For this reason, the air permeable film47causes air (a gas) in the waste ink reservoir portion45to pass therethrough, while it does not cause a liquid such as an ink to pass therethrough. As described in the first embodiment, furthermore, in the case in which the air permeable film47has the liquid repellency, it repels the ink so that the ink sticks thereto with difficulty.

An absorber48shown inFIG. 13is provided in the waste ink reservoir portion45sticking the air permeable film47thereto. The absorber48is cut to have such a length as not to overlap with the air permeable film47. A film49shown inFIG. 13which is formed to have such a shape as to seal the opening of the internal frame portion35is stuck to the lower surface of the internal frame portion35of the upper cover33provided with the absorber48. When the inside of the internal frame portion35is sealed with the film49as shown inFIG. 15, the waste ink reservoir portion45and the flow path44are closed. Consequently, a cartridge side flow path R constituted by the flow path44, the waste ink reservoir portion45and the air communicating hole46is formed so that a second housing portion S2is provided in the upper cover33. Moreover, the air communicating hole46constitutes an exhaust flow path R1.

When the waste ink is introduced from the waste ink introducing portion37, it is sent to the waste ink reservoir portion45through the flow path44and is absorbed in the absorber48. Moreover, air contained in the waste ink passes through the air permeable film47and is pushed out of the air communicating hole46.

When the upper cover33is fixed to the lower cover25, the waste ink introducing portion37is maintained to be fitted in the inside surface of the lead-in portion27of the lower cover25. As a result, the waste liquid needle N2can be inserted into the waste ink introducing portion37through the hole29of the lead-in portion27. Moreover, the first housing portion S1is provided between the inside surface of the lower cover25and the film49of the upper cover33, and the ink pack30is accommodated in the first housing portion S1.

On the other hand, the flow path44of the cartridge C is formed in such a manner that a flow path resistance thereof is varied depending on the cartridge C. More specifically, the first cartridge C1for accommodating a black ink is formed in such a manner that a flow path sectional area A1of the flow path44is the largest and flow path sectional areas A2to A4of the second to fourth cartridges C2to C4are smaller than the flow path sectional area A1of the first cartridge C1(A1>A2=A3=A4).

In detail, the dividing portion42of the first cartridge C1is provided in such a manner that a width between the front wall portion35aand the left wall portion35bis set to be a width W1as shown inFIG. 14. More specifically, the width of the flow path44of the first cartridge C1is equal to the width W1. As shown inFIG. 16, the flow path44of each of the second to fourth cartridges C2to C4is formed to have a width W2which is smaller than the width W1. Moreover, the lengths of the flow paths of the first cartridge C1and the second to fourth cartridges C2to C4are equal to each other and the capacities of the waste ink reservoir portions45are equal to each other.

For this reason, referring to the first cartridge C1and the second to fourth cartridges C2to C4, only the widths W1and W2of the flow paths44are different from each other (that is, W1>W2), and other structures are the same. Accordingly, the flow path resistance of the flow path44of the first cartridge C1for accommodating the black ink (the cartridge side flow path R) is the lowest and the flow path resistances of the flow paths44of the second to fourth cartridges C2to C4(the cartridge side flow path R) are equal to each other.

Next, description will be given to a waste ink collecting procedure for the printer1. The printer1carries out suction cleaning by means of the maintenance mechanism15in a predetermined timing. In the suction cleaning, the sucking pump19is driven with the cap16sealing the lower surface of the recording head10as described above. Consequently, the ink and the air are discharged from the nozzle N of the recording head10into the cap16so that the ink thus discharged is transmitted to the waste ink flow path20provided in the connecting portion5through the sucking pump19.

The waste ink flowing from the inlet20aof the waste ink flow path20is distributed to the waste ink reservoir portion45of each cartridge C based on the flow path resistance of the cartridge side flow path R of the cartridge C. At this time, although the flow path lengths from the inlet20aof the waste ink flow path20to the waste ink reservoir portions46of the first and second cartridges C1and C2are equal to each other, the waste ink is introduced into the first cartridge C1with priority to the second cartridge C2In the third and fourth cartridges C3and C4, the waste ink is stored in a smaller amount than that in each of the first and second cartridges C1and C2based on the flow path length from the inlet20ato the inlet of the waste ink introducing portion37and the flow path resistance of the flow path44.

When the cleaning is carried out plural times, the filling rate of the waste ink in the waste ink reservoir portion45of the first cartridge C1is higher than that of the waste ink reservoir portion45of each of the second to fourth cartridges C2to C4. As described above, moreover, the amount of consumption of an ink in the first cartridge C1is large so that an exchange time comes early. Accordingly, the waste ink reservoir portion45having a high filling rate is exchanged comparatively early with the exchange of the first cartridge C1. In other words, the waste ink can be often discarded in a comparatively large amount. Even if the capacity of each cartridge C is comparatively small, therefore, the waste ink can be stored without a leakage. The waste ink filling rate (waste liquid filling rate) implies a rate of the volume of the waste ink reservoir portion45occupied by the waste ink.

Also in the case in which the first cartridge C1having an early exchange time is unavoidably provided in a distant position from the inlet20aof the waste ink flow path20on the layout of the printer1(the position of the fourth cartridge C4inFIG. 11), moreover, the waste ink filling rate of the first cartridge C1is increased by setting the flow path resistance of the flow path44in the first cartridge C1to be lower than that of each of the other ink cartridges C.

According to the third embodiment, it is possible to obtain the following advantages.

(1) In the first embodiment, each cartridge C includes the first housing portion S1for storing an unused ink and the second housing portion S2for storing the waste ink Each cartridge C is provided with the cartridge side flow path R, and the cartridge side flow path R is constituted by the waste in reservoir portion45, the flow path44communicating with the waste ink reservoir portion45from the waste ink introducing portion37, and the air communicating hole46. Furthermore, the flow path resistance of the cartridge side flow path R of the first cartridge C1having an early exchange time is set to be lower than the flow path resistances of the second to fourth cartridges C2to C4. For this reason, when the waste ink is fed out of the maintenance mechanism15, the waste ink can easily be transmitted to the first cartridge C1. Therefore, it is possible to increase the waste ink filling rate of the first cartridge C1. More specifically, the waste ink can be often discarded in a comparatively large amount. Even if the capacity of the waste ink reservoir portion45of each cartridge C is small, therefore, the waste ink can be collected without a leakage. Accordingly, it is possible to reduce the sizes of the waste ink reservoir portion45and the cartridge C. Moreover, it is possible to control the filling rate of the waste ink of each cartridge C with a simple structure without providing a valve. Furthermore, the resistances of the flow paths provided in the cartridges C are caused to be different from each other. Therefore, it is possible to cause the waste ink filling rates of the cartridges C to be different from each other without changing the structures of the supply flow path4, the discharge flow path18and the waste ink flow path20which are provided on the printer1side and the layout of the cartridges C.

(2) In the third embodiment, the internal frame portion35and the dividing portion42are erected on the upper cover33of the cartridge C. The flow path sectional area of the flow path44for the waste ink which is constituted by the internal frame portion35and the dividing portion42is varied by a change in the position of the dividing portion42. In other words, the flow path sectional area A1(the width W1) of the flow path44of the first cartridge C1is increased and the flow path sectional areas A2to A4(the width W2) of the second to fourth cartridges C2to C4are set to be smaller than the flow path sectional area A1. Therefore, it is possible to cause the flow path resistances of the flow paths44to be different from each other by setting the structure of each cartridge C to be identical in places other than the position of the dividing portion42.

Fourth Embodiment

Next, a fourth embodiment carrying out the invention will be described with reference toFIGS. 17 and 18. In a structure according to the fourth embodiment, the cartridge C according to the third embodiment is simply changed. Therefore, the detailed description of the same portions will be omitted.

In the embodiment, as shown inFIG. 17, a dividing portion42of a first cartridge C1is constituted, and a first dividing portion42aprovided in parallel with a front wall portion35ais formed in such a manner that a length thereof is set to be L1. Moreover, a second dividing portion42bwhich similarly constitutes the dividing portion42is provided in parallel with a left wall portion35band has a length set to be L2. By this structure, a flow path44for causing a waste ink introducing portion37to communicate with a waste ink reservoir portion45has a flow path length La which is almost equal to a length obtained by adding the length L1of the first dividing portion42ato the length L2of the second dividing portion42b(that is, La=L1+L2).

As shown inFIG. 18, moreover, the first dividing portion42aconstituting the dividing portion42of each of second to fourth cartridges C2to C4has a length which is equal to the length of the first dividing portion42aof the first cartridge C1(the length L1). Moreover, the second dividing portion42bformed in parallel with the left wall portion35bis provided to have a length L3in such a manner that it is longer than the second dividing portion42bof the first cartridge C1(that is, L3>L2). For this reason, an expanding and opening portion44aprovided in each of the second to fourth cartridges C2to C4is smaller than the expanding and opening portion44aof the first cartridge C1. Therefore, the flow path44for each of the second to fourth cartridges C2to C4has a flow path length Lb which is greater than the flow path length La of the first cartridge C1(that is, Lb>La).

In the first to fourth cartridges C1to C4, structures other than the dividing portions42are identical. For this reason, the flow path resistance of the flow path44of the first cartridge C1is smaller than that of the flow path44of each of the second to fourth cartridges C2to C4. Accordingly, the waste ink filling rate of the first cartridge C1is higher than that in each of the other cartridges C.

According to the fourth embodiment, therefore, it is possible to obtain the following advantages in addition to the advantages described in (1) of the third embodiment.

(3) In the fourth embodiment, an internal frame portion35and the dividing portion42are erected on an upper cover33of the cartridge C. By a change in the length of the dividing portion42through the cartridge C, the flow path length of the flow path44constituted by the internal frame portion35and the dividing portion42is varied. In other words, the flow path length La of the first cartridge C1is reduced and the flow path length Lb of each of the second to fourth cartridges C2to C4is set to be greater than the flow path length La. Therefore, it is possible to set the structure of each cartridge C to be identical in a place other than the position of the dividing portion42, thereby causing the flow path resistances of the flow paths44to be different from each other.

Fifth Embodiment

Next, a fifth embodiment carrying out the invention will be described with reference toFIG. 19. In a structure according to the fifth embodiment, the cartridge C according to the third embodiment is simply changed. Therefore, the detailed description of the same portions will be omitted.

As shown inFIG. 19, in a first cartridge C1, an air permeable film47for blocking an air communicating hole46has a length from the inside surface of a right wall portion35cto a dividing portion42. Moreover, the air permeable film47has only an edge47astuck to a plate-shaped portion84as described above. Accordingly, air in a waste ink reservoir portion45passes through a portion other than the edge47aof the air permeable film47and flows into a portion between the air permeable film47and the plate-shaped portion34, and is discharged from the air communicating hole46. The air passes through the portion of the air permeable film47other than the edge47aand an air permeable area M1is obtained.

The air permeable film47in each of second to fourth cartridges C2to C4has such a length as not to reach the dividing portion42on the left wall portion35bside from the inside surface of the right wall portion35cof the upper cover33and the air permeable area is set to be an air permeable area M2which is smaller than the air permeable area M1of the air permeable film47of the first cartridge C1(that is, M2<M1) as shown inFIG. 18. More specifically, a space provided between the air permeable film47of the first cartridge C1and the plate-shaped portion34is large and air can be caused to pass in a comparatively large amount. Therefore, the air permeability of the air permeable film47of the first cartridge C1is higher than that of the air permeable film47of each of the other cartridges C. The air permeability indicates the air permeable amount of a gas per unit time in which the air permeable film47transmits the air on the same conditions such as a constant pressure and a constant temperature.

Accordingly, the first cartridge C1easily discharges the air in the waste ink reservoir portion45. Therefore, the flow path resistance of a cartridge side flow path R is lower than that in each of the other cartridges C. For this reason, the first cartridge C1has a higher waste ink filling rate than that of each of the other cartridges C.

According to the fifth embodiment, therefore, it is possible to obtain the following advantages in addition to the advantages described in (1) of the third embodiment.

(4) In the fifth embodiment, the size of the air permeable film47for blocking the air communicating hole46is varied depending on each of the cartridges C. In other words, the air permeable area M1of the air permeable film47provided in the first cartridge C1is set to be large and the air-permeable area M2of the air permeable film47provided in each of the second to fourth cartridges C2to C4is set to be smaller than the air permeable area M1. Therefore, it is possible to easily vary the flow path resistance of the cartridge side flow path R by only setting the structures of the cartridges C to be almost identical to each other and changing the size of the air permeable film47.

Sixth Embodiment

Next, a sixth embodiment carrying out the invention will be described with reference toFIG. 20. In a structure according to the sixth embodiment, the cartridge C according to the third embodiment is simply changed. Therefore, the detailed description of the same portions will be omitted.

As shown inFIG. 20, a cartridge C according to the embodiment comprises a communicating groove50on the upper surface of an upper cover33constituting a case in addition to the structure according to the first embodiment. The communicating groove50is formed in such a manner that an upper surface side is opened, and is extended to meander over the upper surface of the upper cover33from an air communicating hole46. In the upper cover33, moreover, first to third concave portions51to53to be open holes and air communicating portions are provided in the middle or end of the communicating groove50. The first concave portion51is provided in the middle of the communicating groove50and is formed in a position in which a flow path length r1from the air communicating hole46is the smallest. The second concave portion52is provided in the middle of the communicating groove50and is formed in such a manner that a flow path length r2from the air communicating hole46is greater than the flow path length r1of the first concave portion51. The third concave portion53is provided on the termination of the communicating groove50and is formed in a position in which a flow path length r3from the air communicating hole46is the greatest (that is, r1<r2<r3).

A sealing film54is stuck to the upper surface of the upper cover33so that the air communicating hole46, the communicating groove50and the first to third concave portions51to53are sealed therewith. Accordingly, the air discharged from the air communicating hole46is not discharged to an outside until a hole is formed on the sealing film54to form an open hole communicating with the air communicating hole46. Moreover, the air communicating hole46, the communicating groove60and the first to third concave portions51to53constitute an exhaust flow path R1.

When the cartridge C is to be mounted on a printer1, an open hole is formed on the sealing film54to be used. For example, in case of the cartridge C having an early exchange time, an open hole is formed on a portion of the sealing film54which is placed just above the air communicating hole46. In case of the cartridge having a late exchange time, the open hole is formed just above the third concave portion53. In other words, the open hole is formed in a position corresponding to any of the air communicating hole46and the first to third concave portions51to53in the sealing film54to vary the flow path resistance of the exhaust flow path R1(a cartridge side flow path R) of each cartridge C depending on the exchange time of the cartridge C.

In the case in which a waste ink is introduced into the cartridge C, air contained in the waste ink passes through the air communicating hole46via an air permeable film47(seeFIG. 14). For example, in the case in which the open hole is provided in the position of the third concave portion53, the air discharged from the air communicating hole46passes through the communicating groove50and is discharged from the open hole to the outside.

According to the six embodiment; therefore, it is possible to obtain the following advantages in addition to the advantages described in (1) of the third embodiment.

(5) In the sixth embodiment, the communicating groove50communicating with the air communicating hole46is formed on the upper cover33and the first to third concave portions51to53are formed in the middle of the communicating groove50. Moreover, the air communicating hole46, the communicating groove50and the first to third concave portions51to53are sealed by sticking the sealing film54. In use of the cartridge C, the open hole is formed in the position of the air communicating hole46or any of the first to third concave portions51to53corresponding to the exchange time of the cartridge C. Accordingly, it is possible to vary the length of the exhaust flow path R1reaching the open hole from the air communicating hole46by changing the position of the open hole. When the first to third concave portions51to53are previously provided, moreover, a suitable position for forming the open hole is known. Therefore, the flow path resistance can easily be varied. Also in the case in which an ink having a large amount of consumption is varied depending on the type or use situation of the printer1, furthermore, it is possible to properly change the cartridge C having a high waste ink filling rate.

(6) In the sixth embodiment, the cartridges C for accommodating various inks are set to have the same structures and the open hole is formed in use. Consequently, the flow path resistance of the cartridge side flow path R of each cartridge C is varied. Accordingly, it is not necessary to set the structures of the cartridges C to be different from each other. Thus, it is possible to decrease the number of components.

Seventh Embodiment

Next, a seventh embodiment carrying out the invention win be described with reference toFIG. 14. In a structure according to the seventh embodiment, the cartridge C according to the third embodiment is simply changed. Therefore, the detailed description of the same portions will be omitted.

A cartridge C according to the embodiment is formed in such a manner that the thickness or material of an air permeable film47is varied depending on the cartridge C. For example, the air permeable film47of each of second to fourth cartridges C2to C4is formed more thickly as compared with the air permeable film47of a first cartridge C1. For this reason, the air permeability of the air permeable film47of each of the second to fourth cartridges C2to C4is smaller than that of the air permeable film47of the first cartridge C1.

Alternatively, the material of the air permeable film47of the first cartridge C1is different from that of the air permeable film47of each of the second to fourth cartridges C2to C4. For example, in the case in which the air permeable film47is formed by a porous material, the number of fine holes of the air permeable film47of the first cartridge C1is increased or the fine holes are enlarged, resulting in an increase in the air permeability of the air permeable film47itself. Thus, the air permeabilities of the air permeable films47provided in the middle of a cartridge side flow path R are different from each other. Consequently, the flow path resistance of the cartridge side flow path R of the first cartridge C1is lower than that of each of the second to fourth cartridges C2to C4.

According to the seventh embodiment, therefore, it is possible to obtain the following advantages in addition to the advantages described in (1) of the third embodiment.

(7) in the seventh embodiment, the thickness or material of the air permeable film47for blocking an air communicating hole46is varied depending on the cartridge C. In other words, the thickness or material of the air permeable film47provided in the first cartridge C1is changed in such a manner that the air permeability of the air permeable film47is increased. Therefore, it is possible to easily vary the flow path resistance of the cartridge side flow path R by only setting the structures of the cartridges C to be almost identical to each other and changing the thickness or material of the air permeable film47.

The embodiments may be changed in the following manner.While the waste ink collecting system has the ink cartridges C connected in parallel in the second to seventh embodiments, they may be connected in series. At this time, the waste liquid lead-out portion for leading out the waste ink to the upper cover33is provided, and the waste liquid lead-out portions and the waste liquid lead-in portions37in the adjacent ink cartridges C are connected to each other through the waste ink tube18. When the waste ink is discharged to the ink cartridge C collecting the waste ink in a maximum amount, it is discharged to the adjacent ink cartridges C through the waste liquid lead-out portion, the waste ink tube18and the waste liquid lead-in portion37.While the flow path sectional areas are equal to each other and only the flow pass lengths from the pump19are different from each other in the waste ink tubes18connected to the ink cartridges C1and C2in the second embodiment, the flow path sectional areas may be different from each other or the flow path lengths may be equal to each other. Similarly, the flow path sectional areas or the flow path lengths in the waste ink tubes18may be different from each other in the third to seventh embodiments.While the air communicating hole46is provided on the upper cover83in each of the embodiments, it may be provided on the film49. In this case, the film47may be stuck to the upper cover33side or the lower cover35side of the film49.While the waste ink absorber48is formed to take such a size as not to come in contact with the film47in each of the embodiments, the size may be set to be exactly fitted in the internal frame portion35and the waste ink absorber48may come in contact with the film47While the waste ink absorber48is not attached to the flow path44in each of the embodiments, it may be fitted in the flow path44.

Each of the embodiments may be changed in the following manner.While one, four or six cartridge(s) C is/are mounted on the printer1in each of the embodiments, the number of the ink cartridges1may be two or more other than them.In each of the second to seventh embodiments, the waste ink reservoir portions45of the cartridges C may be formed in such a manner that their capacities are different from each other. For example, in the case in which the amount of consumption of a black ink is the largest and the capacity of the waste ink reservoir portion45of the cartridge C for the black ink is larger than that of each of the other waste ink reservoir portions45, the flow path resistance of the cartridge side flow path R may be changed in such a manner that a waste ink filling rate has a predetermined value or more at the exchange time of the cartridge C for the black ink.In each of the third to seventh embodiments, the flow path resistance of the first cartridge C1for accommodating the black ink is set to be the lowest and the flow path resistance of each of the second to fourth cartridges C2to C4is set to be high. In addition, the flow path resistance of the cartridge C other than the first cartridge C1may be set to be the lowest. Moreover, the flow path resistances of the cartridges C may be set to be the lowest. Furthermore, the cartridges C may be formed in such a manner that all of the flow path resistances are different from each other. In brief, it is preferable to reduce the flow path resistance of any of the cartridges C which has a large amount of consumption of an ink (an early exchange time).While the waste ink flow path20is provided in the connecting portion5in the third to seventh embodiments, this structure is not restricted but a tube may be provided.The position of each of the cartridges C in the second to seventh embodiments is not restricted to the arrangement order shown inFIGS. 7 and 11.In each of the embodiments, the flow path44does not need to be provided like an L shape. For example, the flow path44may be formed like a straight line in which an almost U shape and a bent portion are not provided.In the third to seventh embodiments, the flow path resistance of the flow path44may be varied by a change in the shape of the internal frame portion35or that of the dividing portion42. For example, the flow path44of the first cartridge C1may be formed like a straight line and the flow paths44of the other cartridges C may be formed to be bent. Alternatively, the flow path sectional area of the flow path44may be continuously decreased gradually toward a downstream or a member for disturbing the flow of a fluid may be provided in the middle of the flow path44to increase the flow path resistance.In the sixth embodiment, the flow path resistance of the cartridge side flow path R may be varied by a change in the flow path sectional area of the exhaust flow path R1from the air communicating hole46to the open hole. Moreover, a plurality of communicating grooves50may be provided. In this case, the communicating grooves50are formed to communicate with the air communicating hole46of the upper cover83. The communicating grooves50are formed in such a manner that lengths and sectional areas are different from each other. In use of the cartridge C, the open hole corresponding to any of the communicating grooves50is formed to open the communicating groove60to the air. Thus, it is possible to cause the flow path resistances of the cartridge side flow paths R of the cartridges C to be different from each other depending on the flow path resistance of the communicating groove50which is opened to the air.While the printer1for discharging an ink has been described as the liquid injecting apparatus in each of the embodiments, other liquid injecting apparatuses may be employed. For example, it is also possible to employ a printing apparatus including a fax and a copier, a liquid injecting apparatus for injecting a liquid such as an electrode material or a coloring agent to be used for manufacturing a liquid crystal display, an EL display and a surface emitting display, a liquid injecting apparatus for injecting a bioorganism to be used for manufacturing a biochip, and a sample injecting apparatus to be a precision pipette. Moreover, a liquid is not restricted to an ink but an application to other liquids may be carried out.