Liquid ejecting apparatus and liquid charging method

A liquid ejecting apparatus includes a liquid ejecting head with one nozzle group for ejecting one type liquid and another nozzle group for ejecting two types of liquid, thereby ejecting multiple types of liquid from the nozzle groups. A cap forms a sealing space that is suctioned by a suction pump. Flow-passages supply the liquid from a liquid container toward the liquid ejecting head. Flow-passage pumps in the downstream side of the liquid container in the flow-passages suction the liquid from the liquid container and discharge the liquid toward the downstream side. A choke valve has a valve chamber at the downstream side of the flow-passage pump to allow the liquid to flow therein. A flexible member changes a volume of the valve chamber by flexing. A discharge hole in an inner portion of the valve chamber is opened or closed by the flexing of the flexible member.

BACKGROUND

1. Technical Field

The invention relates to a liquid ejecting apparatus and a liquid providing method.

2. Related Art

JP-A-2004-299292 discloses an initial providing manipulation for providing plural types of liquid, which are in a vapor state at the time of staring an initial use of an apparatus, into a plurality of liquid supply passages. A controller disclosed in JP-A-2004-299292 first allows some of a plurality of valve units to be in an opened state and allows all the remaining valve units to be in a closed state. Next, only the liquid supply passages corresponding to the valve units in the opened state are allowed to be precedingly charged. If the preceding charge is completed, the valve units in the opened state is allowed to be closed, and at least a portion of the remaining valve units in the closed state is allowed to be opened to charge the corresponding liquid supply passages.

In addition, JP-A-2008-126408 discloses a configuration where cap portions (first cap portion and second cap portion) are allowed to contact with a nozzle formation portion and where the cap portions are divided into a plurality of partitioned chambers so as to suction each partitioned chamber with a simple, easy configuration.

In addition, JP-A-2008-132712 discloses a configuration where a switching mechanism for changing a type of liquid is included.

However, in the configuration disclosed in JP-A-2008-132712, in the case of performing the initial providing of two types of ink in the liquid ejecting apparatus having the switching mechanism, an ink irrelevant to the two types of ink may also be unnecessarily discarded.

Therefore, a method of reducing the unnecessarily discharging ink amount by adapting the configuration of JP-A-2004-299292 or JP-A-2008-126408 to the configuration of the JP-A-2008-132712 is considered. However, in the aforementioned configuration disclosed in JP-A-2004-299292, since the valve unit is provided to each column so as to reduce the consumed ink amount at the time of initial providing, the cost is increased by the amount corresponding to this configuration. In addition, the control for driving each valve unit is complicated.

In addition, in the configuration disclosed in JP-A-2008-126408, a first cap portion and a second cap portion are provided, and a valve is provided to a tube communicating with the first cap portion, so that the cost is increased by the amount corresponding to this configuration and so that the control is also complicated.

Herein, the configuration where the initial providing of the ink may be performed in the cap having one suction chamber of which the inner portion is not partitioned is advantageous in terms of cost due to the simple configuration of the cap. However, even in the case of using such a cap, it is preferable to prevent the ink from being uselessly wasted.

SUMMARY

An advantage of some aspects of the invention is to provide a liquid ejecting apparatus having a switching mechanism and a simple and easy configuration of a cap and being capable of reducing a uselessly wasted liquid amount and a liquid providing method.

According to an aspect of the invention, there is provided a liquid ejecting apparatus including: a liquid ejecting head which is configured to have a nozzle group of ejecting one type liquid and a nozzle group of ejecting two types of liquid to be capable of ejecting plural types of the liquid from a plurality of the nozzle groups; a cap which is configured to contact with a nozzle formation plane, where the nozzle groups of the liquid ejecting head are exposed, to form one sealing space; a suction pump which is configured to suction the sealing space; a plurality of flow-passages which are configured to supply the plurality types of the liquid from a liquid container toward the liquid ejecting head; flow-passage pumps which are located at the downstream side from the liquid container in the plurality of flow-passages to be capable of suctioning the liquid from the liquid container and discharging the liquid toward the downstream side; a choke valve which is configured to have a valve chamber which is located at the downstream side from the flow-passage pump in the plurality of the flow-passages to allow the liquid to be flown therein, a flexible member which is configured to change a volume of the valve chamber by flexing, and a discharge hole which exists in an inner portion of the valve chamber to be capable of being opened or closed by the flexing of the flexible member, wherein in the case where a predetermined negative pressure or more is exerted to the valve chamber, the flexible member is allowed to close the discharge hole, so that the downstream side thereof is allowed to be in a negative pressure state; a switching mechanism which is located at the downstream side from the choke valve located to two flow-passages among the plurality of the flow-passages and which is connected to one flow-passage for supplying the liquid of the two flow-passages to the nozzle group of ejecting the two types of the liquid to allow supply of some liquid and to block supply of non-selected liquid; a controller which is configured to control operations of the liquid ejecting head, the suction pump, the switching mechanism, and the flow-passage pump, wherein the controller allows all the flow-passage pumps to be operated so as for a predetermined amount of the liquid to be in a dischargeable state, allows the cap to contact with the nozzle formation plane so as for the suction pump to be operated, and allows the switching mechanism to be operated so as for the predetermined amount at the time of providing the liquid into all the flow-passages to be equal to or more than a liquid amount required for providing the liquid into all the flow-passages and to be equal to or less than twice the liquid amount required for providing the ink to all the flow-passages.

According to the configuration, after the operation of the flow-passage pump, the controller allows the cap to contact with the nozzle formation plane so as for the suction pump to be operated. Accordingly, it is possible to provide the liquid to the flow-passage except for the flow-passage which is not selected by the switching mechanism. In addition, since the switching mechanism is driven, it is possible to provide the ink to the flow-passage which is not initially selected by the switching mechanism. At this time, since the dischargeable liquid amount by the operation of the flow-passage pump is controlled to be equal or more than the liquid amount required for providing the ink to all the flow-passages and to be less than twice the liquid amount required for providing the ink to all the flow-passages, it is possible to reduce the liquid amount which is uselessly discharged. In addition, since the initial providing of the liquid is performed by using the cap which forms one sealing space, the configuration of the cap is simplified, so that it is possible to reduce the cost. In addition, it is possible to suppress the configuration from being complicated, so that it is possible to reduce the cost.

In the liquid ejecting apparatus according to the invention, the controller allows all the flow-passage pumps to be operated so as for a predetermined amount of the liquid to be in a dischargeable sate, allows the cap to contact with the nozzle formation plane so as for the suction pump to be operated, and allows the switching mechanism to be operated so as for the predetermined amount at the time of providing the liquid into all the flow-passages to be equal to or more than a liquid amount required for providing the liquid into all the flow-passages and to be equal to or less than a liquid amount obtained by adding a liquid amount required for providing the liquid into all the flow-passages of the downstream side from the choke valve to the liquid amount required for providing the liquid into all the flow-passages.

According to the configuration, since the controller controls the dischargeable liquid amount by the operation of the flow-passage pump to be equal to or more than a liquid amount required for providing the liquid into all the flow-passages and to be equal to or less than a liquid amount obtained by adding a liquid amount required for providing the liquid into all the flow-passages of the downstream side from the choke valve to the liquid amount required for providing the liquid into all the flow-passages, it is possible to reduce the liquid amount which is uselessly discharged.

In the liquid ejecting apparatus according to the invention, the controller allows the switching mechanism to be operated so as for a first selecting operation of allowing supply from the one of the flow-passages of supplying the two types of the liquid to be performed, allows all the flow-passage pumps to be operated so as for a liquid amount required for providing the liquid into all the flow-passages to be in a dischargeable state, allows the cap to contact with the nozzle formation plane so as for the suction pump to be operated so as for first suction of the liquid from the nozzle of the liquid ejecting head to be performed, allows the switching mechanism to be operated so as for a second selecting operation of allowing supply from the other of the flow-passages of supplying the two types of the liquid to be performed, and allows the cap to contact with the nozzle formation plane so as for the suction pump to be operated again so as for second suction of the liquid from the nozzle of the liquid ejecting head to be performed.

According to the configuration, if the flow-passage pump is allowed to be operated and if the cap is allowed to contact with the nozzle formation plane so as for the suction pump to be operated, it is possible to provide the liquid into all the flow-passages except for the flow-passage which is not selected among the flow-passages for supplying the two types of the liquid. At this time, in the other flow-passage, which is not selected, the portions of the downstream side of the switching mechanism is in the state where large negative pressure is exerted by the operation of the suction pump. In addition, in all the flow-passages except for the flow-passage which is not selected, since the subsequent supply of the liquid is not performed by only allowing the flow-passage pump to perform the operation of discharging the liquid amount required for providing the liquid into all the flow-passages, the choke valve is in the closed state by the operation of the suction pump, so that the supply of the liquid is blocked.

On the other hand, in the other flow-passage which is not selected in the above case, the liquid is in the pressed state by the aforementioned operation of the flow-passage pump. After that, if the switching mechanism is allowed to be operated and if the second selecting operation of allowing the supplying of the liquid from the other flow-passage which is not selected in the above case is performed, the negative pressure is exerted to the portions of the downstream side from the switching mechanism and the liquid exists in the pressed state in the other flow-passage which is not selected, so that it is possible to provide the liquid into the other flow-passage which is not selected. In addition, in the second selecting operation, since there is no supply of the liquid from the flow-passage pump in the flow-passages except for the other flow-passage which is not selected, the choke valve is in the closed state, so that it is possible to suppress the liquid from being discharged.

Accordingly, unlike the related art, in the case where the initial providing of the two types of the ink is performed in the liquid ejecting apparatus having the switching mechanism, it is possible to prevent the ink irrelevant to the two types of the ink from being uselessly wasted.

In the liquid ejecting apparatus according to the invention, the controller, after the second suction or at the same time of the second suction, allows all the flow-passage pumps to be operated so as for the liquid of the liquid amount required for providing the liquid into all the flow-passages of the downstream side from the choke valve to be supplied through the flow-passages toward the liquid ejecting head.

According to the configuration, due to the operation of the suction pump, it is possible to remove the negative pressure exerted to the flow-passage of the downstream side from the choke valve. In other words, in the case where the aforementioned negative pressure is not removed, the exertion of the negative pressure may cause a problem in that the liquid discharged into the cap may be flown backward from the nozzle. However, after the second suction by the suction pump or at the same time of the second suction, if the flow-passage pump is allowed to be operated and if the liquid of the liquid amount required for providing the liquid into all the flow-passages of the downstream side from the choke valve is supplied, the negative pressure may be removed, so that it is possible to prevent the liquid from being flown backward from the nozzle.

In the liquid ejecting apparatus according to the invention, the liquid ejecting apparatus includes, at the downstream side from the choke valve, a pressure chamber which the liquid is flown into, a flexible member which is configured to change a volume of the pressure chamber by flexing in response to a change in an internal pressure of the pressure chamber, and a pressure adjusting valve which is configured to be opened in the case where the internal pressure of the pressure chamber is less than a predetermined pressure by the flexing of the flexible member and to be closed in the other cases, wherein the controller, after the second suction or at the same time of the second suction, allows all the flow-passage pumps to be operated so as for the liquid of the liquid amount required for providing the liquid into the pressure adjusting valve and all the flow-passages of the downstream side from the pressure adjusting valve to be supplied through the flow-passages toward the liquid ejecting head.

According to the configuration, due to the operation of the suction pump, it is possible to remove the negative pressure exerted to the pressure adjusting valve and the flow-passage of the downstream side from the pressure adjusting valve. In other words, in the case where the aforementioned negative pressure is not removed, the exertion of the negative pressure may cause a problem in that the liquid discharged into the cap may be flown backward from the nozzle. However, after the second suction by the suction pump or at the same time of the second suction, if the flow-passage pump is allowed to be operated and if the liquid of the liquid amount required for providing the liquid into the pressure adjusting valve and all the flow-passages of the downstream side from the pressure adjusting valve is supplied, the negative pressure may be removed, so that it is possible to prevent the liquid from being flown backward from the nozzle.

According to another aspect of the invention, there is provided a liquid providing method of performing initial providing of a liquid in a liquid ejecting apparatus, wherein the liquid ejecting apparatus includes: a liquid ejecting head which is configured to have a nozzle group of ejecting one type liquid and a nozzle group of ejecting two types of liquid to be capable of ejecting plural types of the liquid from a plurality of the nozzle groups; a cap which is configured to contact with a nozzle formation plane, where the nozzle groups of the liquid ejecting head are exposed, to form one sealing space; a suction pump which is configured to suction the sealing space; a plurality of flow-passages which are configured to supply the plurality types of the liquid from a liquid container toward the liquid ejecting head; a flow-passage pump which is located at the downstream side from the liquid container in the plurality of flow-passages to be capable of suctioning the liquid from the liquid container and discharging the liquid toward the downstream side; a choke valve which is configured to have a valve chamber which is located at the downstream side from the flow-passage pump in the plurality of the flow-passages to allow the liquid to be flown therein, a flexible member which is configured to change a volume of the valve chamber by flexing, and a discharge hole which exists in an inner portion of the valve chamber to be capable of being opened or closed by the flexing of the flexible member, wherein in the case where a predetermined negative pressure or more is exerted to the valve chamber, the flexible member is allowed to close the discharge hole, so that the downstream side thereof is allowed to be in a negative pressure state; a switching mechanism which is located at the downstream side from the choke valve located to two flow-passages among the plurality of the flow-passages and which is connected to one flow-passage for supplying the liquid of the two flow-passages to the nozzle group of ejecting the two types of the liquid to allow supply of some liquid and to block supply of non-selected liquid; a controller which is configured to control operations of the liquid ejecting head, the suction pump, the switching mechanism, and the flow-passage pump, the liquid providing method including: allowing the switching mechanism to be operated so as for a first selecting operation of allowing supply from the one of the flow-passages of supplying the two types of the liquid to be performed; allowing all the flow-passage pumps to be operated so as for a liquid amount required for providing the liquid into all the flow-passages to be in a dischargeable state; allowing the cap to contact with the nozzle formation plane so as for the suction pump to be operated so as for first suction of the liquid from the nozzle of the liquid ejecting head to be performed; allowing the switching mechanism to be operated so as for a second selecting operation of allowing supply from the other of the flow-passages of supplying the two types of the liquid to be performed; and allowing the cap to contact with the nozzle formation plane so as for the suction pump to be operated again so as for second suction of the liquid from the nozzle of the liquid ejecting head to be performed.

According to the configuration, if the flow-passage pump is allowed to be operated and if the cap is allowed to contact with the nozzle formation plane so as for the suction pump to be operated, it is possible to provide the liquid into all the flow-passages except for the flow-passage which is not selected among the flow-passages for supplying the two types of the liquid. At this time, in the other flow-passage, which is not selected, the portions of the downstream side of the switching mechanism is in the state where large negative pressure is exerted by the operation of the suction pump. In addition, in all the flow-passages except for the flow-passage which is not selected, since the subsequent supply of the liquid is not performed by only allowing the flow-passage pump to perform the operation of discharging the liquid amount required for providing the liquid into all the flow-passages, the choke valve is in the closed state by the operation of the suction pump, so that the supply of the liquid is blocked.

On the other hand, in the other flow-passage which is not selected in the above case, the liquid is in the pressed state by the aforementioned one-cycle operation of the flow-passage pump. After that, if the switching mechanism is allowed to be operated and if the second selecting operation of allowing the supplying of the liquid from the other flow-passage which is not selected in the above case is performed, the negative pressure is exerted to the portions of the downstream side from the switching mechanism and the liquid exists in the pressed state in the other flow-passage which is not selected, so that it is possible to provide the liquid into the other flow-passage which is not selected. In addition, in the second selecting operation, since there is no supply of the liquid from the flow-passage pump in the flow-passages except for the other flow-passage which is not selected, the choke valve is in the closed state, so that it is possible to suppress the liquid from being discharged.

Accordingly, unlike the related art, in the case where the initial providing of the two types of the ink is performed in the liquid ejecting apparatus having the switching mechanism, it is possible to prevent the ink irrelevant to the two types of the ink from being uselessly wasted.

In the liquid providing method of performing initial providing of a liquid in a liquid ejecting apparatus according to the invention, the liquid providing method includes after the second suction or at the same time of the second suction, allowing all the flow-passage pumps to be operated so as for the liquid of the liquid amount required for providing the liquid into all the flow-passages of the downstream side from the choke valve to be supplied through the flow-passages toward the liquid ejecting head.

According to the configuration, due to the operation of the suction pump, it is possible to remove the negative pressure exerted to the flow-passage of the downstream side from the choke valve. In other words, in the case where the aforementioned negative pressure is not removed, the exertion of the negative pressure may cause a problem in that the liquid discharged into the cap may be flown backward from the nozzle. However, after the second suction by the suction pump or at the same time of the second suction, if the flow-passage pump is allowed to be operated and if the liquid of the liquid amount required for providing the liquid into all the flow-passages of the downstream side from the choke valve is supplied, the negative pressure may be removed, so that it is possible to prevent the liquid from being flown backward from the nozzle.

In the liquid providing method of performing initial providing of a liquid in a liquid ejecting apparatus according to the invention, the liquid ejecting head includes: at the downstream side from the choke valve, a pressure chamber which the liquid is flown into, a flexible member which is configured to change a volume of the pressure chamber by flexing in response to a change in an internal pressure of the pressure chamber, and a pressure adjusting valve which is configured to be opened in the case where the internal pressure of the pressure chamber is less than a predetermined pressure by the flexing of the flexible member and to be closed in the other cases, wherein the liquid providing method comprises: after the second suction or at the same time of the second suction, allowing all the flow-passage pumps to be operated so as for the liquid of the liquid amount required for providing the liquid into the pressure adjusting valve and all the flow-passages of the downstream side from the pressure adjusting valve to be supplied through the flow-passages toward the liquid ejecting head.

According to the configuration, due to the operation of the suction pump, it is possible to remove the negative pressure exerted to the pressure adjusting valve and the flow-passage of the downstream side from the pressure adjusting valve. In other words, in the case where the aforementioned negative pressure is not removed, the exertion of the negative pressure may cause a problem in that the liquid discharged into the cap may be flown backward from the nozzle. However, after the second suction by the suction pump or at the same time of the second suction, if the flow-passage pump is allowed to be operated and if the liquid of the liquid amount required for providing the liquid into the pressure adjusting valve and all the flow-passages of the downstream side from the pressure adjusting valve is supplied, the negative pressure may be removed, so that it is possible to prevent the liquid from being flown backward from the nozzle.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, a printer10as a liquid ejecting apparatus according to an embodiment of the invention will be described with reference toFIGS. 1 to 9. In addition, in the description hereinafter, a lower side denotes a chassis side where the printer10is disposed, and an upper side denotes a side which is separated from the side where the printer10is disposed. In addition, a direction of movement of a carriage31is set to a main-scan direction, and a direction which is perpendicular to the main-scan direction and which a printing medium P is to be transported is set to a sub-scan direction. In addition, a side to which the printing medium P is fed is denoted by a sheet feeding side, and a side from which the printing medium P is discharged is denoted by a sheet discharging side.

Schematic Configuration of Printer

First, a schematic configuration of the printer10is described.FIG. 1is a perspective view illustrating a schematic configuration of the printer10according to an embodiment of the invention, wherein an upstream side (sheet feeding side) of sheet transporting is disposed at the front side, and a downstream side (sheet discharging side) of the sheet transporting is disposed at the rear side. In addition,FIG. 2is a schematic diagram illustrating the configuration of the printer10.

The printer10according to the embodiment includes a chassis21, a housing22, a carriage mechanism30, a sheet transporting mechanism40, an ink supply mechanism50, a cleaning mechanism60, and a controller70,

Among these components, the chassis21is a portion of which the lower surface side is in contacted with an installation surface and on which various units are mounted. In addition, the housing22indicated by a two-dot dashed line inFIG. 1is mounted on the chassis21. The housing22has the same planar shape as that of the aforementioned chassis21.

In addition, as illustrated inFIGS. 1 and 2, the carriage mechanism30includes a carriage31, a carriage shaft32on which the carriage31slidingly moves, and a print head33. In addition, the carriage mechanism30includes a carriage motor (CR motor)34, a gear pulley35which is attached to the CR motor34, a driven pulley37, and an endless belt36which is suspended between the gear pulley35and the driven pulley37. Ink (corresponding to the liquid) supplied through the later-described ink supply mechanism50is ejected from the print head33(corresponding to an ejecting head) to the printing medium P.

In addition, as illustrated inFIG. 2, the sheet transporting mechanism40includes a sheet transporting motor (PF motor)41, a feed roller43of which the driving force is transmitted from the sheet transporting motor41, and the like.

In addition, inFIG. 1, for example, a so-called off-carriage type printer10, where the ink cartridge51(corresponding to a liquid container) is mounted on the chassis21side, is illustrated. However, the printer is not limited to the off-carriage type, a so-called on-carriage type printer, where the ink cartridge is mounted on the carriage, may be used.

Herein, in the embodiment, the ink cartridge51includes an ink cartridge of storing cyan (indicated by C inFIG. 3), magenta (indicated by M inFIG. 3), yellow (indicated by Y inFIG. 3) and an ink cartridge of storing two types of black ink. The two types of black ink are, for example, a photo black (indicated by PK inFIG. 3) ink for implementing high glossiness printing on a glossy paper and a matt black (indicated by MK inFIG. 3) ink suitable for a matt paper having no glossiness.

In addition, the aforementioned print head33is provided with nozzle groups of a nozzle33a(refer toFIG. 3) for ejecting the cyan ink, a nozzle33afor ejecting the magenta ink, and a nozzle33afor ejecting the yellow ink. In addition, there is only one nozzle33afor ejecting the black ink (in other words, the nozzle is shared by the two types of black ink.), so that the black ink selected between the two types of the ink by the later-described switching mechanism58is ejected.

Ink Supply Mechanism

Next, a configuration of the ink supply mechanism50is described with reference toFIGS. 3 to 7.FIGS. 3 and 4are diagrams illustrating the entire flow of the ink supply mechanism50and the cleaning mechanism60. The ink supply mechanism50includes, as main components, an ink supply needle52, a first check valve53, a flow-passage pump54, a second check valve55, a choke valve56, a pressure adjusting valve57, a switching mechanism58, and first to seventh flow-passages59ato59g.

In addition, the first to seventh flow-passages59ato59gmay be referred to as flow-passages59if these flow-passages are not necessarily to be distinguished.

As illustrated inFIG. 3, the flow-passage pump54, the choke valve56, and the pressure adjusting valve57in the ink supply mechanism50are provided to each ink cartridge51. In addition, although not illustrated inFIG. 3, the first check valve53and the second check valve55are provided to each flow-passage pump54. However, as described later, since the switching mechanism58illustrated inFIG. 3is a device of allowing any one of the photo black ink and the matt black ink to be flown into the seventh flow-passage59gillustrated inFIG. 4, the switching mechanism58is connected to the sixth flow-passage59ffor flowing the photo black ink and connected to the sixth flow-passage59ffor flowing the matt black ink, and the other ink cartridges51are not connected to the sixth flow-passage59f.

The ink supply needle52is a portion of insertion into the an ink supply inlet51aof the ink cartridge51, and due to the insertion, the ink supply needle52and the ink supply inlet51aare connected to each other in the state that the ink may be able to be flown.

The first check valve53is a member of allowing the ink to flowing from the ink cartridge51to the downstream side but preventing the ink from returning from the flow-passage pump54to the ink cartridge51. As illustrated inFIG. 4, the first check valve53includes an internal space531formed by the housing530, a flexible valve532, and a biasing spring533. In the internal space531, a valve seat531bis disposed to a bottom portion531a, and a spring receiving portion531dis disposed to a top portion531copposite to the bottom portion531a. In the internal space531, the flexible valve532is disposed, and the flexible valve532may be flexible (deformable) so as to be detachable to the valve seat531b. Due to the existence of the flexible valve532, the internal space531is partitioned into an upstream chamber534A which communicates with the first flow-passage59asupplied with the ink from the ink cartridge51and a downstream chamber534B which communicates with the second flow-passage59bfor supplying the ink to the flow-passage pump54.

In addition, a through-hole532ais disposed at the center of the flexible valve532in the diameter direction thereof. In addition, the flexible valve532is provided with a ring-shaped protrusion532bwhich is disposed to protrude toward the valve seat531band to surround the through-hole532a. When the protrusion532bis not in contact with the valve seat531b, the ink which is flown into the upstream chamber534A passes through the through-hole532aand the downstream chamber534B to be flown into the second flow-passage59b.

In addition, a biasing force being directed toward the valve seat531bis exerted to the flexible valve532by the biasing spring533. The one end side of the biasing spring533is allowed to contact with the spring receiving portion531d, and the outer end side thereof is allowed to contact with the flexible valve532. Therefore, the biasing spring533exerts a biasing force for forcing the flexible valve532to be directed toward the valve seat531b. In addition, due to the biasing force, in the state where a negative pressure or the like is not exerted to the downstream chamber534B, the protrusion532bis allowed to contact with the valve seat531b.

In addition, a flow-passage pump54is disposed at the downstream side from the first check valve53through the second flow-passage59b. The flow-passage pump54includes an internal space541which is formed by the housing540, a diaphragm542, and a coil spring543. Due to the existence of the diaphragm542, the internal space541may be partitioned into two portions, that is, a pump chamber544A and a negative pressure chamber544B. The pump chamber544A is configured to communicate with the second flow-passage59band to communicate with the third flow-passage59c. The third flow-passage59cis a flow-passage which is located at the downstream side from the flow-passage pump54as seen in the order of the ink supply passages toward the print head33and which is configured to communicate with the second check valve55. In addition, in the internal space541, the diaphragm542is flexible (deformable) so as to be allowed to contact with the bottom portion541aof the pump chamber544A and flexible (deformable) so as to be allowed to contact with the top portion541bof the negative pressure chamber544B.

In addition, a spring receiving portion541cis disposed to the top portion541bof the negative pressure chamber544B. The one end side of the coil spring543, which exerts an external force to the pump chamber544A is allowed to contact with the spring receiving portion541c. In addition, the other end side of the coil spring543is allowed to contact with the diaphragm542. Therefore, a biasing force for allowing the diaphragm542to contact with the bottom portion541aof the pump chamber544A is exerted to the diaphragm542by the coil spring543. In addition, due to the biasing force, in the state where the later-described negative pressure is not exerted to the negative pressure chamber544B, the diaphragm542is allowed to contact with the bottom portion541aof the pump chamber544A, so that the flow of the ink being directed toward the downstream side is blocked.

Herein, an atmospheric opening valve546is connected through the air flow-passage545to the negative pressure chamber544B. In the state where a valve structure (not shown) is closed, the atmospheric opening valve546blocks an inflow of air being directed from an external portion to the negative pressure chamber544B. If the later-described depressurizing pump547is operated to be in the blocked state, a negative pressure may be exerted to the negative pressure chamber544B. Therefore, due to the function of the negative pressure, the diaphragm542may be allowed to oppose against the spring force of the coil spring543and to be separated from the bottom portion541aof the pump chamber544A. In addition, the side separated from the negative pressure chamber544B rather than the atmospheric opening valve546of the air flow-passage545is connected to the depressurizing pump547. The depressurizing pump547is a pump which is driven to exert a negative pressure to the negative pressure chamber544B. In addition, the driving of the depressurizing pump547is controlled by the controller70.

In addition, although the configuration of the second check valve55is similar to the configuration of the aforementioned first check valve53, the second check valve55is different from the first check valve53in that the through-hole is not formed in the second check valve55. In addition, in the second check valve55, the third flow-passage59cat the upstream side is configured to always communicate with the inflow chamber552A. The flexible valve553of the second check valve55is biased by the biasing member554in the valve-closing direction for closing the fourth flow-passage59d. Therefore, in the case where the pressure of the inflow chamber552A is less than a predetermined pressure as well as in the case where the inflow chamber552A is in the negative pressure state, the flexible valve553of the second check valve55is not opened, so that the backward flow of the ink to the third flow-passage59cis prevented. In addition, the ink is flown from the third flow-passage59cof the upstream side into the inner portion of the inflow chamber552A of the second check valve55, so that the pressure of the inflow chamber552A may be equal to or larger than a predetermined pressure. In this case, the flexible valve553of the second check valve55resists the pressing force of the biasing member554to be deformed in the direction of allowing the internal volume of the inflow chamber552A to increase, so that the flexible valve553is opened. Therefore, the fourth flow-passage59dof the downstream side communicates with the third flow-passage59cof the upstream side through the inner portion of the inflow chamber552A. In addition, description of the same components of the second check valve55as those of the first check valve53is omitted.

In addition, a choke valve56is disposed along the fourth flow-passage59dtoward the downstream side. As illustrated inFIG. 5, the choke valve56includes a concave portion560formed by a molding product560aand a film561(corresponding to a flexible member). The concave portion560is configured to communicate with the fourth flow-passage59d. In addition, the concave portion560is formed to be depressed more deeply than other portions except for the later-described annular convex portion563. In addition, by attaching a film561so as to cover the concave portion560, the choke valve chamber562is configured. An annular convex portion563is disposed at the center or substantially center of the choke valve chamber562(concave portion560) in the diameter direction thereof. The annular convex portion563is configured to protrude up to the same level as the portion other than the concave portion560in the molding product560a. In the annular convex portion563, a contacting portion which the film561is attached/detached to/from is disposed in the vicinity of the later-described discharge hole564. In addition, the film561is flexible (deformable) so that the film561is attached/detached to/from the annular convex portion563.

In addition, the annular convex portion563is provided with a discharge hole564which is an inlet of the fifth flow-passage59e. In other words, in the state where the film561is not in contact with the annular convex portion563, the discharge hole564is in the opened state, so that the flow of the ink toward the fifth flow-passage59eis allowed. However, if the film561is allowed to contact with the annular convex portion563due to the decrease in the internal pressure of the choke valve chamber562, the discharge hole564is in the closed state, the flow of the ink toward the fifth flow-passage59eis blocked. According to such a configuration, the function as the choke valve56may be implemented.

In addition, a pressure adjusting valve57is disposed along the fifth flow-passage59etoward the downstream side. As illustrated inFIG. 6, the pressure adjusting valve57includes an ink supply chamber571A and a pressure chamber571B which are formed by the housing570, a valve structure572, a plate-shaped member573, a film574, and a biasing spring575. The ink supply chamber571A is a portion into which the ink is flown from the fifth flow-passage59eand which is configured to communicate with the pressure chamber571B through the communicating hole576. In addition, the sealing portion572aof the valve structure572is located in the ink supply chamber571A. The sealing portion572ais provided with a protrusion572b. The protrusion572bis configured to have a ring shape of surrounding the bottom portion of the outer side from the outer circumference of the communicating hole576(the side wall of the side of the ink supply chamber571A where the communicating hole576is formed is denoted by the bottom portion571A1). Therefore, if the protrusion572bis in contact with the bottom portion571A1of the ink supply chamber571A, the periphery of the communicating hole576is closed by the protrusion572b, so that the flow of the ink toward the communicating hole576is blocked.

In addition to the aforementioned sealing portion572a, a shaft portion572cis provided to the valve structure572. As illustrated inFIG. 6, the shaft portion572cis a portion which is inserted into the communicating hole576and of which the front end portion is configured to protrude to the pressure chamber571B. The front end portion of the shaft portion572cis connected to the plate-shaped member573. In addition, the plate-shaped member573is adhered to the film574. In addition, the film574is flexed (deformed) according to the change in the pressure of the pressure chamber571B, so that a volume of the pressure chamber571B may be changed. In addition, in the pressure chamber571B, a portion facing the film574becomes a bottom portion571B1.

In addition, between the plate-shaped member573and the bottom portion571B1of the pressure chamber571B, a biasing spring575is disposed. The biasing spring575exerts a biasing force for separating the film574from the bottom portion571B1of the pressure chamber571B. In other words, in the state where a negative pressure is not exerted to the pressure chamber571B (in the state where a sufficient amount of ink exists), the film574is separated from the bottom portion571B1by the biasing force exerted from the biasing spring575. Due to the separating operation, the valve structure572is moved to the film574, and the protrusion572bis allowed to contact with the periphery of the communicating hole576in the bottom portion571A1, so that the periphery of the communicating hole576is closed. Therefore, the flow of the ink toward the communicating hole576is blocked. On the contrary, due to the ink ejection of the print head33, if the ink is consummated, the amount of the ink of the inner portion of the pressure chamber571B is decreased, so that the film574is flexed toward the ink supply chamber571A by the corresponding amount. At this time, as the pressure difference between the internal pressure of the pressure chamber571B and the atmospheric pressure is increased so that the biasing force of the biasing spring575may be able to be opposed, the film574and the valve structure572are moved toward the right side inFIG. 6, so that the protrusion572bis separated from the bottom portion571A1. Accordingly, the ink is supplied from the ink supply chamber571A to the pressure chamber571B through the communicating hole576. If a predetermined amount of the ink is supplied, the film574is moved to the side so as to be separated from the bottom portion571B1.

In addition, as directing toward the downstream along the sixth flow-passage59fof flowing two types of black ink, a switching mechanism58is disposed as illustrated inFIG. 7. The switching mechanism58may switch the ink ejected from the nozzle33aof the print head33between the photo black ink and the matt black ink according to whether the printing medium P is, for example, a glossy paper or, for example, matt paper.

As illustrated inFIG. 7, the switching mechanism58includes a main body581, a film582, a sealing member583, a shaft member584, a first arm585A and a second arm585B, and a plate cam587. The main body581is provided with a pair of recessed fitting portions581A (581A1and581A2). Each of the pair of the recessed fitting portions581A is configured to communicate with the corresponding sixth flow-passage59f.

Herein the one recessed fitting portion581A1is configured to communicate with the sixth flow-passage59ffor supplying, for example, the photo black ink. In addition, the other recessed fitting portion581A2is configured to communicate with the sixth flow-passage59ffor supplying the matt black ink. In addition, a ring-shaped valve seat581cwhich further protrudes in comparison with other portions of the bottom portion581bis disposed to the bottom portion581bof the recessed fitting portion581A, and the insertion hole588is formed at the center of the valve seat581c. Although the sealing member583is inserted into the recessed fitting portion581A, in the state where the sealing member583is separated from the valve seat581c, the flow of the ink from the recessed fitting portion581A to the insertion hole588is allowed. On the contrary, in the state where the sealing member583is allowed to contact with the valve seat581c, the flow of the ink from the recessed fitting portion581A to the insertion hole588is blocked.

In addition, the sealing member583is attached to the film582which liquid-tightly covers the recessed fitting portion581A. Therefore, the ink is flown into the recessed fitting portion581A, the film582is flexed in such a direction that the sealing member583is separated from the valve seat581cby the flexing.

The aforementioned insertion hole588is connected to the seventh flow-passage59g, so that the ink may be supplied through the seventh flow-passage59gto the print head33. In addition, the shaft member584is inserted into the insertion hole588. The length of the shaft member584is slightly larger than the length of the insertion hole588. Therefore, in the state where the one sealing member583is inserted so as to contact with the valve seat581c, the other sealing member583is separated from the valve seat581cby the shaft member584. In addition, although two end portions of the shaft member584become enlarged diameter portions584aof which the diameter is larger than other portions, the diameter of each of the enlarged diameter portions584ahas a size corresponding to an inner diameter of the insertion hole588. However, since a portion of the enlarged diameter portion584ain the principal direction is notched (not shown), the flow of the ink to the insertion hole588is allowed due to the existence of the cut portion.

In addition, as illustrated inFIG. 7, the first arm585A and the second arm585B are disposed to intersect each other, and the pin586which passes through the two arms is disposed at the intersecting portion. Therefore, the first arm585A and the second arm585B may be rotated by the pin586. Between the first arm585A and the second arm585B, the one end side near to the recessed fitting portion581A becomes the pressing portion585cfor pressing the sealing member583.

In addition, between the first arm585A and the second arm585B, the other end side being separated from the recessed fitting portion581A becomes the cam contacting portion585dwhich is allowed to contact with the plate cam587. The plate cam587is installed so that the distance from the rotation shaft587ato the cam plane587bis changed. Therefore, a pressing area587C and a separating area587D exist therein. In other words, the pressing area587C is an area where the cam plane587bis nearest to the rotation shaft587awhich is the center of rotation and a portion where, when the sealing member583is pressed by the pressing portion585c, the cam contacting portion585dis allowed to contact with the cam plane587b. In addition, the separating area587D is an area where the cam plane587bis farthest from the rotation shaft587awhich is the center of rotation and a portion where, when the pressing portion585cis separated from the sealing member583, the cam contacting portion585dis allowed to contact with the cam plane587b.

In addition, the spring members589are provided between the cam contacting portion585dfrom the pin586in the first arm585A and the pressing portion585cfrom the pin586in the second arm585B and between the pressing portion585cfrom the pin586in the first arm585A and the cam contacting portion585dfrom the pin586in the second arm585B. The spring members589exert a biasing force to each other in such a direction that the installation portions are separated from each other. Therefore, the cam contacting portion585dof the first arm585A and the cam contacting portion585dof the second arm585B are allowed to simultaneously contact with the plate cam587.

If the plate cam587is rotated by a motor (not shown) driven by the above switching mechanism58, the one of the pressing portion585cof the first arm585A and the pressing portion585cof the second arm585B presses the sealing member583, so that the sealing member583is allowed to contact with the valve seat581cof the one recessed fitting portion581A. Therefore, the flow of the ink to the insertion hole588is blocked. At the same time, the other of the pressing portion585cof the first arm585A and the pressing portion585cof the second arm585B is separated from the sealing member583. Therefore, if the flow of the ink into the other recessed fitting portion581A causes the flexing of the film582, the sealing member583is not allowed to contact with the valve seat581c. Accordingly, the ink is allowed to flow through the insertion hole588toward the seventh flow-passage59g. In addition, the seventh flow-passage59gis configured to communicate with the nozzle33aof the print head33.

Cleaning Mechanism

Subsequently, the cleaning mechanism60is described. The chassis21is provided with the cleaning mechanism60as illustrated inFIGS. 1,3, and4. The cleaning mechanism60includes a cap61, an ink discharge tube62, a waste tank63, and a suction pump64.

Among these components, the cap61is a portion which seals the nozzle formation plane (not shown) where the nozzle33aas the nozzle group of the print head33to form one sealing space. Therefore, the cap61may be lifted up and down by a lifting mechanism (not shown). In addition, the one end side of the ink discharge tube62is connected to the cap61, and the other end side thereof is connected to the waste tank63. In addition, the waste tank63is a portion which stores the ink discharged from the nozzle33aof the print head33to the cap61. In addition, the suction pump64is connected to an intermediate portion of the ink discharge tube62. Therefore, if the suction pump64is operated, the ink may be discharged from the nozzle33atoward the waste tank63.

Controller

As illustrated inFIG. 2, the printer10is provided with a controller70. The controller70includes an interface71and a CPU, a memory, an ASIC (Application Specific Integrated Circuit), a bus, a timer, and the like which are not shown. In addition, the controller70is input with signals from various sensors, and the controller70controls driving of a CR motor34, a PF motor41, a pump motor (not shown) of a depressurizing pump547, a pump motor (not shown) of a suction pump64, a print head33, and the like based on the signals from the sensors or irrespective of the sensors. In addition, programs and data used for controlling the driving are stored in a memory.

Operations at Time of Initially Providing Ink in Print Head

Subsequently, operations at the time of initially providing the ink in the print head33in the printer10having the aforementioned configuration are described with reference toFIGS. 8A and 8BandFIGS. 9A to 9C.

First Initial Providing

1. Operations of Depressurizing pump547(Generation of Negative Pressure)

If the initial providing operation is selected in the controller70, the controller70performs a selecting operation so that any one black ink is supplied to the nozzle33a(first selecting operation). In other words, the controller70drives the switching mechanism58to allow the plate cam587to be rotated due to operation of a motor (not shown), so that the pressing portion585cof the one side is separated from the sealing member583and so that the pressing portion585cof the other side presses the sealing member583. Accordingly, in the recessed fitting portion581A for supplying the black ink of the one side, the sealing member583is separated from the valve seat581c, so that the black ink of the one side is supplied. However, in the recessed fitting portion581A for supplying the black ink of the other side, the sealing member583is allowed to contact with the valve seat581c, so that the black ink of the other side is blocked not to be supplied.

After the selection is performed, the controller70allows the depressurizing pump547to be operated. At this time, the atmospheric opening valve546is in the closed state. Accordingly, the pressure of the negative pressure chamber544B becomes a negative pressure by the depressurizing pump547, the diaphragm542is flexed from the state where it is allowed to contact with the bottom portion541aof the pump chamber544A as illustrated inFIG. 4to the state where it is allowed to contact with the top portion541bof the negative pressure chamber544B as illustrated inFIG. 8B.

At this time, the flexible valve553of the second check valve55is in the state of closing the fourth flow-passage59ddue to the function of the negative pressure, so that no negative pressure is exerted to the flow-passages of the downstream side therefrom. On the other hand, the pump chamber544A is also in the negative pressure state, so that the negative pressure is exerted to the first check valve53through the second flow-passage59b. At this time, the downstream chamber534B of the first check valve53is in a negative pressure state, so that the flexible valve532is flexed so as to oppose the biasing force of the biasing spring533due to the negative pressure. Therefore, the protrusion532bis separated from the valve seat531b, so that the negative pressure is exerted to the ink cartridge51through the upstream chamber534A and the first flow-passage59a. Accordingly, the ink stored in the ink cartridge51is flown into the upstream chamber534A through the first flow-passage59a. In addition, if the ink is flown into the upstream chamber534A, the flexible valve532maintains the state where the flexible valve532is pressed up to the downstream chamber534B. The ink is flown into the downstream chamber534B through the through-hole532a. Sequentially, the ink is flown from the downstream chamber534B through the second flow-passage59binto the pump chamber544A. In addition, the ink is also inserted into the third flow-passage59c.

In addition, the flow of the ink into the pump chamber544A and the third flow-passage59care performed with respect to all the ink cartridges51. In other words, both of the photo black ink and the matt black ink are flown into the pump chamber544A and the third flow-passage59c, respectively. In addition, the behavior of the ink being directed toward the downstream side at this time is illustrated inFIG. 9A.

2. Operations of Suction Pump

As described above, by the control of the controller70, in the state where the diaphragm542is in contact with the top portion541bof the negative pressure chamber544B, subsequently, the suction pump64is allowed to be operated (first suction). As a result, with respect to the pressure adjusting valve57, the pressure chamber571B is in a negative pressure state, so that the film574is flexed toward the ink supply chamber571A due to the negative pressure. Accordingly, since the valve structure572is inserted into the ink supply chamber571A by opposing the spring force of the biasing spring575, the protrusion572bis separated from the bottom portion571A1, so that the ink supply chamber571A is allowed to communicate with the pressure chamber571B through the communicating hole576. Therefore, a negative pressure is also exerted to the ink supply chamber571A, and the negative pressure is exerted to the choke valve chamber562of the choke valve56through the fifth flow-passage59eand the discharge hole564.

In addition, the choke valve chamber562is in a negative pressure state, so that the film561is flexed toward the bottom portion of the concave portion560. Due to the flexing operation, the film561is in contact with the annular convex portion563. As a result, the periphery of the discharge hole564is closed by the film561, and due to the operation of an additional suction pump64, the film561is allowed to be strongly pressed to the annular convex portion563by large pressure. On the other hand, the portions (the fifth flow-passage59e, the pressure adjusting valve57, and the sixth flow-passage59for the like) of the downstream side from the discharge hole564are in large negative pressure state due to the operation of the suction pump64. In addition, the reaching points of the ink at this time are illustrated inFIG. 9A.

Subsequently, by the control of the controller70, the depressurizing pump547is stopped to be operated, and the atmospheric opening valve546is operated to be in an opened state. As a result, as illustrated inFIG. 8A, in the flow-passage pump54, the negative pressure state of the negative pressure chamber544B is removed, and the diaphragm542is pressed by the coil spring543. Accordingly, the ink is flown into the inflow chamber552A, and thus, the pressure of the inflow chamber552A becomes equal to or more than a predetermined pressure, so that the flexible valve553is opened. Therefore, the ink is flown through the third flow-passage59c, the second check valve55, and the fourth flow-passage59dinto the choke valve chamber562of the choke valve56.

In the choke valve56, a pressing force is exerted to the film561due to the inflow of the ink. If the pressing force overcomes a suction force (a force generated by a negative pressure) between the annular convex portion563and the film561, the film561is separated from the annular convex portion563. As a result, due to the function of the negative pressure, the ink together with air bubbles is flown into the print head33at one time and discharged from the nozzle33ainto the cap61. Accordingly, in the portions into which the ink is discharged from the nozzle33a, the initial providing by which the portions ranging from the ink cartridge51to the nozzle33aare filled with the ink is completed.

After such ink is discharged into the cap61, by continuing the operation of the suction pump64or in the state where the operation of the suction pump64is stopped but the remaining negative pressure is exerted, the negative pressure is exerted to the choke valve chamber562of the choke valve56again, so that the film561is pressed to the annular convex portion563by large pressure (the choke valve56is closed). In addition, by continuing the operation of the suction pump64, the portions (the fifth flow-passage59e, the pressure adjusting valve57, the sixth flow-passage59f, and the like) of the downstream side from the discharge hole564are in a negative pressure state. In addition, in the portions into which the ink is discharged from the nozzle33a, the discharging of the ink from the nozzle33adoes not occur, but the state where the portions between the ink cartridge51to the nozzle33aare filled with the ink is sustained. In other words, the initial providing of the one black ink, the cyan ink, and the magenta ink, and the yellow ink is completed.

On the other hand, in the side where the pressing portion585cis pressed into the sealing member583by the switching mechanism58, no negative pressure is exerted to the pressure adjusting valve57and the choke valve56. Therefore, the diaphragm542is pressed by the coil spring543, and only the pressing force is exerted to the third flow-passage59c, the first check valve53, the fourth flow-passage59d, the choke valve chamber562of the choke valve56and the pressure adjusting valve57. In addition, although the ink is flown into the pressure chamber571B of the pressure adjusting valve57in a predetermined pressed state, since the pressing portion585cis pressed into the sealing member583as described above, the initial providing of the other black ink is not yet completed.

Second Initial Providing

4. Operations of Switching Mechanism58

In the aforementioned state, by the control of the controller70, the switching mechanism58is allowed to be operated (second selecting operation), and the plate cam587is allowed to rotate by the operation of a motor (not shown). Hereinbefore, in the side (referred to as the other side) where the pressing portion585cis pressed into the sealing member583, the sealed state is removed, and in the different side (referred to as the one side), the sealing member583is pressed by the pressing portion585c.

After that, the suction pump64is allowed to be operated (second suction). In addition, in the case where a sufficient negative pressure remains, the suction pump64may not be operated. Herein, in the recessed fitting portion581A for supplying the black ink to the other side in the switching mechanism58, since the sealing member583is separated from the valve seat581c, the negative pressure, which is exerted to the downstream side from the insertion hole588and the seventh flow-passage59g, is exerted to the upstream side thereof. On the other hand, as described above, the ink is flown into the upstream side from the sealing member583in a predetermined pressed state. Therefore, as described above, if the sealing member583is separated from the valve seat581c, the other side of the black ink together with air bubbles is flown into the print head33at one time and discharged from the nozzle33ainto the cap61. Accordingly, the initial providing of the other side of the black ink is completed. In other words, the state illustrated inFIG. 9Cis obtained.

5. Other Operations

In addition to the aforementioned operations, after the operations of (4), while continuing the operation of the suction pump64or in the state where the operation of the suction pump64is stopped but the remaining negative pressure is exerted, the flow-passage pump54is allowed to be operated, so that the ink may be supplied t the print head33. Herein, an amount of the ink supplied by the operation is necessarily smaller than the providing ink amount in the first initial providing. In this case, this is because the discharging ink amount at one cycle including the first initial providing and the second initial providing is less than twice the ink amount required for providing the ink to all the flow-passages, so that the discharging ink amount is decreased in comparison with the related art.

In addition, the ink amount supplied by the operation may be used as the ink amount for providing the portions to which large negative pressure is exerted by continuing the operation of the suction pump64(or the ink amount for removing the negative pressure of the portions to which large negative pressure is exerted).

More specifically, the ink amount for providing all the flow-passages of the downstream side from the discharge hole564of the choke valve56, to which the negative pressure is exerted, may be used. In addition, by taking into consideration that the change in the volume of the fifth flow-passage59ecaused by the exertion of the negative pressure is very small, the ink amount for providing all the flow-passages of the downstream side from the pressure chamber571B and the pressure chamber571B of the pressure adjusting valve57may be used.

In this case, by continuing the operation of the suction pump64, the ink may be flown into the portions, to which large negative pressure is exerted, or into the portions, where the operation of the suction pump64is stopped but the remaining negative pressure is exerted, so that the negative pressure of the portions, which the large negative pressure is exerted to, may be removed. Therefore, it is possible to prevent the ink discharged into the cap61from being suctioned from the nozzle33a.

Effects

According to the printer10having the aforementioned configuration, after one cycle of the operation of the flow-passage pump54, the controller70allows the cap61to contact with the nozzle formation plane, where the nozzle33ais exposed, and allows the suction pump64to be operated. Accordingly, the ink may be provided into the flow-passage59from the upstream side to the downstream side in the flow-passages except for the flow-passage59which is not selected by the switching mechanism58. In addition, since the switching mechanism58is driven, the ink may be provided into the flow-passage59which is not initially selected by the switching mechanism58. At this time, since the ink amount discharged by the contraction of the pump chamber544A is controlled to be less than twice the ink amount required for providing the ink into all the portions from the upstream side to the downstream side of the flow-passage59, it is possible to reduce the ink amount that is uselessly discharged.

In addition, since the initial providing of the ink is performed by using the cap61which forms one sealing space, the configuration of the cap61is simplified, so that it is possible to reduce the cost. In addition, in the ink supply mechanism50, the configuration is prevented from being complicated, so that it is possible to reduce the cost.

In addition, a pressure adjusting valve57is disposed at the upstream side from the switching mechanism58and at the downstream side from the flow-passage pump54in the flow-passage59. The pressure adjusting valve57has a pressure chamber571B into which the ink flown and is configured to be opened in the case where an internal pressure of the pressure chamber571B is less than a predetermined pressure due to a decrease in the ink amount and to be closed in the other cases.

Therefore, in the case where the print head33dose not consume the ink, it is possible to prevent an excessive ink amount from being supplied from the pressure chamber571B to the print head33, so that it is possible to optimize the ejection of the ink from the print head33.

In addition, in the embodiment, if the flow-passage pump54is allowed to be operated at one cycle and if the cap61is allowed to contact with the nozzle formation plane so as for the suction pump64to be operated, it is possible to provide the ink into all the flow-passages59except for the flow-passage59, which is not selected by the switching mechanism58, among the flow-passages59for supplying two types of black ink. At this time, the other flow-passage59, which is not selected, is in the state where a large negative pressure is exerted to the downstream side from the switching mechanism58by the operation of the suction pump64. In addition, in all the flow-passages59except for the flow-passage59, which is not selected, since the subsequent supply of the ink is not performed by only the one cycle operation of the flow-passage pump54, the choke valve56is in the closed state by the operation of the suction pump64, so that the supply of the ink is blocked. In the other flow-passage59, which is not selected, the ink is in the pressed state by the one cycle operation of the flow-passage pump54. After that, if the switching mechanism58is allowed to be operated and the operation of allowing the supply of the ink from the other flow-passage59, which is not selected, is performed, the negative pressure is exerted to the downstream side from the switching mechanism58, and the ink is in the pressed state in the other flow-passage59, which is not selected, so that it is possible to provide the ink into the other flow-passage59, which is not selected.

In addition, since the ink is not supplied from the flow-passage pump54from the upstream side to the downstream side in the flow-passages except for 59, which is not initially selected, and since the choke valve56is still in the closed state, it is possible to suppress the ink from being discharged.

Accordingly, unlike the related art, in the case where the initial providing of the two types of ink is performed in the printer10having the switching mechanism58, it is possible to prevent the ink irrelevant to the two types of the ink from being uselessly wasted.

In addition, in the aforementioned embodiment of the invention, after providing the ink into the other flow-passage59, which is not initially selected (or after performing the second suction of the suction pump64) or together with the providing (or together with performing the second suction of the suction pump64), the controller70allows the flow-passage pump54to be operated so as for a predetermined ink amount to be supplied through flow-passage59to the print head33.

Therefore, due to the operation of the suction pump64, it is possible to remove the negative pressure exerted to the flow-passage59of the downstream side from the choke valve56. In other words, in the case where the aforementioned negative pressure is not removed, the exertion of the negative pressure may cause a problem in that the ink discharged into the cap61may be flown backwards from the nozzle33a. However, after providing the ink into the other flow-passage59, which is not initially selected (or after performing the second suction of the suction pump64) or together with the providing (or together with performing the second suction of the suction pump64), if the flow-passage pump54is allowed to be operated so as for a predetermined ink amount to be supplied, the negative pressure may be removed, so that it is possible to prevent the ink from being flown backward from the nozzle33a.

In addition, in the case where the ink is flown into from the nozzle33adue to the backward flow, since the ink in the cap61is flown thereto, the mixture of the ink of the colors is flown thereto, so that an image quality of the printing result on the printing medium P deteriorates. However, as described above, the negative pressure is removed by the supply of a predetermined ink amount, so that it is possible to maintain the image quality of the printing result on the printing medium P in a good state.

Modified Example

Hereinbefore, the embodiment of the invention is described. However, various modifications may be available for the invention. Hereinafter, the modifications will be described.

In the aforementioned embodiments, the ink supply mechanism50is a flow-passage pump which may control a discharging ink amount. The ink supply mechanism50is a flow-passage pump54, so-called a diaphragm pump, which is configured to have a diaphragm542capable of flexing a pump chamber544A which suctions the ink at the time of expansion in an internal volume due to an externally applied force and discharges the ink at the time of contraction in the internal volume due to an externally applied force. However, besides the diaphragm pump, any pump which is controlled to suction the ink from the ink cartridge51and to discharge a predetermined ink amount may be used as the flow-passage pump54.

For example, a reciprocating movement pump such as a piston pump and a plunger pump and a rotary pump such as a tube pump, a gear pump, a vane pump, and a screw pump may be used. In the case of the reciprocating movement pump, similarly to the diaphragm pump, if the dischargeable ink amount per one cycle (one reciprocating movement) is acquired, the controller may control a predetermined ink amount to be discharged by operating the pump at one cycle or at a plurality of cycles. In addition, in the case of the rotary pump, if the dischargeable ink amount per one rotation is acquired, the controller may control a predetermined ink amount to be discharged by operating the pump at the necessary number of rotations.

In the aforementioned embodiments, the ink supply mechanism50includes a first check valve53, a second check valve55, and a pressure adjusting valve57. However, the ink supply mechanism50may has a configuration where at least one of the above components is not provided. This is because the ink supply mechanism50having the configuration where at least one of the first check valve53, the second check valve55, and the pressure adjusting valve57is not provided may also achieve the invention.

In addition, in the aforementioned embodiments, the first check valve53, the second check valve55, the choke valve56, and the pressure adjusting valve57may also have different configurations. For example, instead of the configuration having a film (diaphragm), these valves may employ various types of valves such as a swing type valve, a wafer chucky type valve, a lift type valve, or a foot valve.

In addition, in the aforementioned embodiments, the ink cartridge51is configured to individually store cyan ink, magenta ink, yellow ink, photo black ink, and matt black ink. However, the ink cartridge51is not limited to storing such inks, but for example, at least one of light cyan, light magenta, gray, light gray, green, orange, and the like may be stored. In addition, in the aforementioned embodiments, the inks of which the supplying is switched by the switching mechanism58are the photo black ink and the matt black ink. However, the inks of which the supplying is switched by the switching mechanism58are not limited to the photo black ink and the matt black ink. For example, the gray ink and the light gray ink or the light magenta ink and the vivid light magenta ink are configured to be switched.

In addition, in the aforementioned embodiments, the depressurizing pump547is driven; after that, the suction pump64is driven; and after that, the atmospheric opening valve546is driven. However, before the operation of the depressurizing pump547, the suction pump64may be operated.

In addition, in the aforementioned embodiments, as “(5) Other Operations”, by continuing the operations of the suction pump64or in the state where the operation of the suction pump64is stopped but the remaining negative pressure is exerted, the flow-passage pump54is allowed to be operated so as for the ink to be supplied to the print head33, so that the negative pressure of the portions, which the large negative pressure is exerted to, is removed. Therefore, it is possible to prevent the ink discharged into the cap61from being suctioned from the nozzle33a. However, in the case where, although a negative pressure is exerted, the flexing portion is small, so that the volume of the flow-passage is not almost changed, the controller70allows the print head33to be driven instead of the operation of the suction pump64, the ink amount which is flown into the nozzle33adue to the negative pressure or an ink amount equal to or more than the ink amount may be ejected. In this case, although the mixture of the ink of the colors is flown into the nozzle33a, the mixed ink is dischargeable from the nozzle33a, it is possible to maintain the image quality of the printing result on the printing medium P in a good state.

In addition, in the aforementioned embodiments, the discharging ink amount per one cycle including the first initial providing and the second initial providing is configured to be less than twice the ink amount required for providing the ink to all the flow-passages. Herein, in the case of performing the aforementioned operations of (1) to (4), although the discharging ink amount is more than one or more times the ink amount required for providing the ink to all the flow-passages, the increased portion is obtained by adding the portion which is flown into the cap61due the influence of the negative pressure at the time of operation of the suction pump64. However, this added portion is a very small amount and is greatly smaller than twice the ink amount required for providing the ink to all the flow-passages.

In addition, in the case of performing the aforementioned operation of (5), by taking into consideration that the portions which the negative pressure is exerted to is the downstream side from the choke valve56, the discharging ink amount is obtained by adding the ink amount for providing the portions, which large negative pressure is exerted to, by continuing the operation of the suction pump64or the ink amount for removing the negative pressure of the portions, which large negative pressure is exerted to, to once the ink amount required for providing the ink to all the flow-passages, so that the discharging ink amount is greatly smaller than twice the ink amount required for providing the ink to all the flow-passages.

The ink amount discharged by the above operation may be the ink amount for providing all the flow-passages of the downstream side from the discharge hole564of the choke valve56, which the negative pressure is exerted. In addition, by taking into consideration that the change in the volume of the fifth flow-passage59eby the exertion of the negative pressure is very small, the ink amount discharged by the above operation may be the ink amount for providing all the flow-passages of the downstream side from the pressure chamber571B and the pressure chamber571B of the pressure adjusting valve57.

In addition, although the ink amount which is flown into the cap61due to the influence of the negative pressure by continuing the operation of the suction pump64may be added, since the ink amount is very small, the discharging ink amount is greatly smaller than twice the discharging ink amount of the related art.

In addition, in the aforementioned embodiments, the controller70may be implemented in a software manner or has a configuration implemented in a circuit manner.

In addition, the printer10is not limited to an inkjet type printer10, but for example, a gel jet type printer may be used. In addition, besides the printer, a multifunctional apparatus including a scanner machine, a facsimile machine, a copying machine, or the like may be employed as a printer according to the invention.

In addition, in a concept of the printer10According to the aforementioned embodiments, there may be included a fluid ejecting apparatus which ejects a liquid (including a liquid itself, a liquid state material where particles of a functional material are dispersed or mixed into a liquid, or a material having fluidity such as gel) other than ink. As an example, there are a liquid state material ejecting apparatus for ejecting a liquid which contains dispersed or dissolved materials such as electrode materials or colorant materials (materials for pixels) used for manufacturing a liquid crystal display, an EL (Electroluminescence) display, and a surface emission display or the like, a fluid ejecting apparatus for ejecting bio-organic materials used for manufacturing a bio chip, a fluid ejecting apparatus for ejecting a liquid which is a sample used as a precision pipette, or the like.

In addition, in a concept of the printer10According to the invention, there may be included a fluid ejecting apparatus for ejecting a lubricant into a precision machine such as a watch or a camera by using a pinpoint, a fluid ejecting apparatus for ejecting a transparent resin solution such as a UV cured resin on a substrate in order to form semispherical micro-lenses (optical lenses) used for an optical communication device or the like, a fluid ejecting apparatus for ejecting an etchant such as an acidic solution or an alkali solution in order to etch a substrate or the like, a fluid state material ejecting apparatus for ejecting a fluid state material such as gel (for example, physical gel), or the like.

The entire disclosure of Japanese Patent Application No. 2009-222103, filed Sep. 28, 2009 and 2010-156586, filed Jul. 9, 2010 are expressly incorporated by reference herein.