Patent Publication Number: US-2022219459-A1

Title: Inkjet printing apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of U.S. patent application Ser. No. 16/835,081, filed on Mar. 30, 2020, which claims the benefit of Japanese Patent Application No. 2019-072551, filed Apr. 5, 2019, each of which are hereby incorporated by reference herein in their entireties. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to an inkjet printing apparatus. 
     Description of the Related Art 
     An inkjet printing apparatus performs printing by discharging ink. One type of inkjet printing apparatus includes a discharge head that discharges ink, and an ink storage member that stores ink to be supplied to the discharge head. Japanese Patent Application Laid-Open No. 2018-69696 discusses an inkjet printing apparatus that enables a user to refill an ink storage member with ink from an ink bottle. The ink is consumed by being discharged. 
     In an inkjet printing apparatus such as the one discussed in Japanese Patent Application Laid-Open No. 2018-69696, it is easy to increase the capacity of an ink bottle for ink refilling, and the capacity of an ink storage member to which ink is added. Therefore, as compared with an ordinary inkjet printing apparatus that uses an ink cartridge as an ink storage member, the frequency of ink refilling (replacement in the case of an ink cartridge) is reduced and thus usability is easily improved. 
     SUMMARY OF THE INVENTION 
     According to an aspect of the present invention, an inkjet printing apparatus includes a discharge head that discharges ink, and a housing that contains the discharge head, wherein the housing contains a first ink storage member and a second ink storage member that each store ink, and the ink is supplied from each of the first ink storage member and the second ink storage member to the discharge head, wherein the first ink storage member is an ink cartridge not having an ink refilling port for enabling ink refilling by opening a stopper member, and detachable from the inkjet printing apparatus, and wherein the second ink storage member has the ink refilling port. 
     Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A and 1B  are perspective views of an inkjet printing apparatus. 
         FIG. 2  is a perspective view of the inkjet printing apparatus. 
         FIGS. 3A and 3B  are diagrams illustrating a first ink storage member. 
         FIGS. 4A and 4B  are diagrams illustrating the first ink storage member, as well as second and third ink storage members. 
         FIG. 5  is a diagram illustrating the first ink storage member and the second ink storage member. 
         FIGS. 6A and 6B  are diagrams illustrating the first ink storage member and the third ink storage member. 
         FIG. 7  is a diagram illustrating the first, second, and third ink storage members, as well as a fourth ink storage member. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     According to a study made by the inventors, the inventors have found such an issue that evaporation of moisture in ink from an ink storage member of an ink-refilling type tends to progress. The ink storage member capable of being refilled with ink has an ink refilling port for ink refilling. Normally, the ink refilling port is closed with a stopper member, but evaporation of the moisture in the ink from the stopper member and the periphery thereof can progress. Further, in general, the ink storage member capable of being refilled with ink has a large capacity. Therefore, this type of ink storage member is often left unused for a long time without being refilled with ink. In such a case, the amount of evaporation of moisture from the ink storage member increases. If the evaporation of the moisture from the ink in the ink storage member thus progresses, the density (e.g., color material density) of the stored ink increases. If such ink is supplied to a discharge head and then discharged (printing is performed), the desired darkness or color tone of a printed image or character may not be achieved. 
     Therefore, the present invention is directed to an inkjet printing apparatus that can inhibit a change in darkness and color tone of a printed image or character due to evaporation of moisture in ink, even in a case where an ink storage member capable of being refilled with ink is used to improve usability. 
     An inkjet printing apparatus according to an exemplary embodiment of the present invention will be described below with reference to the drawings.  FIGS. 1A and 1B  each illustrate an example of a perspective view of the inkjet printing apparatus according to the present exemplary embodiment. As illustrated in  FIG. 1A , an inkjet printing apparatus  1  has a housing  2  and a cover member  3  provided on a top surface of the housing  2 .  FIG. 1B  is a diagram illustrating a state where the cover member  3  of the inkjet printing apparatus  1  is opened so that the inside of the housing  2  is visible. The housing  2  is substantially shaped like a rectangular parallelepiped, and includes a sheet feeding tray  4  at a rear part.  FIG. 1B  illustrates a state where the sheet feeding tray  4  is extended from the housing  2 . 
       FIG. 2  is a diagram illustrating the inside of the housing  2  of the inkjet printing apparatus  1  in  FIG. 1B , in a state where the inside of the housing  2  is viewed more easily by removing an outer wall of the housing  2 . The housing  2  includes the sheet feeding tray  4  on the rear side, as also illustrated in  FIGS. 1A and 1B . A printing medium such as a sheet of paper is to be placed on the sheet feeding tray  4 . 
     The housing  2  contains a first ink storage member  8  and a second ink storage member  9 . Further, in the example illustrated here, a third ink storage member  10  is provided inside the housing  2 . Ink is supplied from the second ink storage member  9  to the third ink storage member  10 . The first ink storage member  8  and the third ink storage member  10  are each provided with a discharge head (not illustrated in  FIG. 2 ) at a part lower in a gravitational direction. The ink is supplied from each of the first ink storage member  8  and the third ink storage member  10  to the corresponding discharge head connected thereto. The gravitational direction in the present specification is a z direction in  FIG. 2 , and refers to a gravitational direction at the time of using the inkjet printing apparatus  1 . The discharge head is provided with a discharge port for ink discharge, and an energy generating element that generates energy for the discharge. The discharge head discharges the ink from the discharge port, while reciprocally moving in a y direction in  FIG. 2 . 
     The printing medium placed on the sheet feeding tray  4  is sent by a sheet feeding roller  5  and a conveyance roller  6  in an x direction that is a frontward direction, and then supported by a platen  7  upon arriving at the platen  7 . The printing medium supported by the platen  7  is placed at a position facing the discharge head. In this state, the ink is discharged from the discharge head to the printing medium. The discharged ink lands on the printing medium, so that an image is recorded on the printing medium. 
     The ink adheres to a discharge port surface where the discharge port of the discharge head is open. Therefore, the discharge port surface can be cleaned by recovery members such as a wiper  11  and a cap  12  that are provided inside the housing  2 . 
     Next, the first ink storage member  8  will be described. The first ink storage member  8  is provided inside the housing  2 . Here, an example will be described in which the first ink storage member  8  stores color ink of cyan, magenta, and yellow colors.  FIGS. 3A and 3B  each illustrate an enlarged view of the first ink storage member  8 .  FIG. 3A  illustrates a state where a lid of the first ink storage member  8  is removed. An ink storage portion  8   a  stores the ink of cyan, an ink storage portion  8   b  stores the ink of magenta, and an ink storage portion  8   c  stores the ink of yellow. Further, the first ink storage member  8  has an electrical wiring member  13  for supplying power from outside to the discharge head. 
       FIG. 3B  is an exploded view of the first ink storage member  8 , and illustrates a state where the first ink storage member  8  is viewed from an angle different from that in  FIG. 3A . Ink absorbing members  14   a ,  14   b , and  14   c  are disposed in the ink storage portions  8   a ,  8   b , and  8   c , respectively, of the first ink storage member  8 . The ink absorbing members  14   a ,  14   b , and  14   c  are sponge-like members, and each hold the ink. Filters  15   a ,  15   b , and  15   c  are each disposed at a lower part of the corresponding one of the ink storage portions  8   a ,  8   b , and  8   c  in the gravitational direction. The discharge head  16  is provided at a lower part of the first ink storage member  8  in the gravitational direction. The discharge head  16  has the energy generating element and the discharge port, and is disposed on a support member  17 . In the example illustrated in  FIGS. 3A and 3B , the discharge head  16  has a discharge port array corresponding to the above-described three colors. The discharge head  16  of this example may also be referred to as a printing element substrate. The discharge head  16  is bonded to the first ink storage member  8  via the support member  17  to be integral with the first ink storage member  8 . The discharge head  16  is driven by the power supplied from the electrical wiring member  13 . The first ink storage member  8  is an ink cartridge not having an ink refilling port for ink refilling from the outside by a user and a stopper member for closing the ink refilling port, and detachable alone from the inkjet printing apparatus  1 . 
     Next, the second ink storage member  9  will be described. The second ink storage member  9  is provided inside the housing  2 , as with the first ink storage member  8 . However, while the first ink storage member  8  does not have an ink refilling port for enabling ink refilling and a stopper member, the second ink storage member  9  has an ink refilling port for enabling ink refilling and a stopper member.  FIGS. 4A and 4B  illustrate the second ink storage member  9  and a system for supplying the ink to the second ink storage member  9 .  FIG. 4A  illustrates the first ink storage member  8  and the third ink storage member  10 , in addition to the second ink storage member  9 .  FIG. 4B  schematically illustrates the second ink storage member  9  and the third ink storage member  10 . The second ink storage member  9  is an ink tank that has an ink refilling port  9   a  for enabling ink refilling, as described above. The ink refilling port  9   a  is closed with a stopper member  9   b . The stopper member  9   b  is formed of, for example, rubber. A user opens the ink refilling port  9   a  by opening the stopper member  9   b , and inserts an ink bottle  20  into the opened ink refilling port  9   a . The ink bottle  20  stores ink, and the ink is supplied from the ink bottle  20  to the second ink storage member  9 . The second ink storage member  9  is thus refilled with the external color ink. 
     The second ink storage member  9  is connected to the third ink storage member  10  at a connection port  19  by a tube  18 , as illustrated in  FIGS. 4A and 4B . The ink stored in the second ink storage member  9  is supplied to the third ink storage member  10  via the tube  18 . Here, a case where the second ink storage member  9  and the third ink storage member  10  each store black ink is illustrated as an example. The third ink storage member  10  is not partitioned into three rooms, and has only one room and one corresponding filter. Otherwise, basically, the third ink storage member  10  has a configuration similar to that of the above-described first ink storage member  8 . In other words, the discharge head  16  integral with the third ink storage member  10  is provided at a part lower of the third ink storage member  10  in the gravitational direction. The inside of the discharge head  16  connects to the third ink storage member  10 , and discharges the ink supplied from the third ink storage member  10 . 
     The first ink storage member  8  provided inside the housing  2  is an ink cartridge not having an ink refilling port for enabling ink refilling by opening a stopper member, and detachable from the inkjet printing apparatus  1 . In contrast, the second ink storage member  9  similarly provided inside the housing  2  is an ink storage member having an ink refilling port for enabling refilling of the second ink storage member  9  with ink. 
     The first ink storage member  8  stores, for example, color ink (ink of colors such as yellow, cyan, and magenta) that is not frequently used. The amount of consumption of such ink is small in many cases, and thus it is not necessary to provide an ink refilling port in the first ink storage member  8 . Therefore, a change in darkness and color tone of a printed image or character due to evaporation of moisture from the ink refilling port can be inhibited. In addition, because the first ink storage member  8  is an ink cartridge detachable from the inkjet printing apparatus  1 , it is also possible to inhibit progress of evaporation of moisture that occurs when the stored ink is left unused for a long time. 
     On the other hand, the second ink storage member  9  stores, for example, frequently-used black ink (ink of black color). The amount of consumption of such ink is large, and thus the ink refilling port is provided to enable ink refilling, so that usability can be improved. 
     In other words, because the inkjet printing apparatus  1  has the first ink storage member  8  and the second ink storage member  9  described above, there is provided such a configuration that refilling with a certain type of ink is enabled, while evaporation of moisture from other types of ink does not easily occur. In other words, the usability of ink refilling is improved, and a change in darkness and color tone of a printed image or character due to evaporation of moisture is inhibited, in the inkjet printing apparatus  1  as a whole. 
     The ink stored in each of the first ink storage member  8  and the second ink storage member  9  is not determined based on the use frequency alone. This will be described in detail below. 
     In the present exemplary embodiment, the first ink storage member  8  and the second ink storage member  9  are provided inside the housing  2 . For example, if the second ink storage member  9  having the ink refilling port is provided outside the housing  2 , such a configuration leads to an increase in the size of the entire inkjet printing apparatus  1 , so that usability is impaired. Moreover, if the second ink storage member  9  is provided outside the housing  2 , a distance for supplying the ink from the second ink storage member  9  to the discharge head  16  increases. The increase in the distance for supplying the ink leads to easy evaporation of moisture from the ink, and thus affects an image to be printed. 
     Desirably, the first ink storage member  8  does not have a tube or joint from the first ink storage member  8  to the discharge head  16  in order to inhibit the evaporation of moisture from the ink. The evaporation of the moisture not only affects an image to be printed, but also leads to ink clogging of the discharge head  16  due to ink adhesion. However, even if such a situation occurs, the first ink storage member  8  can be removed from the inkjet printing apparatus  1  to be individually replaced, because the first ink storage member  8  is an ink cartridge. 
     The first ink storage member  8  is an ink cartridge. Therefore, desirably, for example, the first ink storage member  8  can be removed from the inkjet printing apparatus  1 , so that printing can be performed by using only the ink stored in the second ink storage member  9  having the refilling port. In the above-described example, the second ink storage member  9  stores the black ink. In this case, if the first ink storage member  8  is removed and recording is performed without the first ink storage member  8 , the inkjet printing apparatus  1  can be used as a printing apparatus that prints a monochrome image using the black ink. In such a case, it is desirable that another member (a dummy member) different from the first ink storage member  8  be disposed in an area where the first ink storage member  8  has been disposed, in the inkjet printing apparatus  1 . 
     The member that supplies the ink to the third ink storage member  10  having the discharge head  16  via the tube  18  is described as the second ink storage member  9 , but the second ink storage member  9  is not limited to such a member. For example, it is possible to provide the second ink storage member  9  as an ink cartridge, without providing the third ink storage member  10 .  FIG. 5  is an enlarged view of the first ink storage member  8  and the second ink storage member  9  disposed inside the housing  2  of the inkjet printing apparatus  1 , as viewed from above in the gravitational direction. The first ink storage member  8  and the second ink storage member  9  are provided on a carriage  21 , and each have the discharge head  16  at a part lower in the gravitational direction. The first ink storage member  8  and the second ink storage member  9  each discharge the ink, while moving on the carriage  21  in a y direction. In this configuration, the inkjet printing apparatus  1  does not have the third ink storage member  10 , and the first ink storage member  8  and the second ink storage member  9  are both ink cartridges. However, the second ink storage member  9  has the ink refilling port (the ink refilling port  9   a ) for enabling ink refilling from the ink bottle  20  by opening the stopper member, whereas the first ink storage member  8  does not have such a port. The inkjet printing apparatus thus configured can also inhibit a change in darkness and color tone of a printed image or character due to evaporation of moisture, while improving usability. Further, in this configuration, a place to be accessed by the user in each of these storage members when the ink runs out is a place on the carriage  21 , and the respective places are adjacent to each other. Therefore, this configuration easily improves usability, and also reduces the size of the inkjet printing apparatus. However, because the second ink storage member  9  is an ink cartridge, the inkjet printing apparatus described with reference to  FIGS. 4A  and  4 B is more desirable to increase the capacity for the ink to be stored in the second ink storage member  9 . 
     Next, a position of the discharge head when the second ink storage member  9  is refilled with the ink will be described. In the state illustrated in  FIG. 2 , as described above, the discharge head is disposed at the lower part of each of the first ink storage member  8  and the third ink storage member  10  in the gravitational direction. In this state, the second ink storage member  9  and the discharge head are on the same side (the −y side), in a direction (the y direction) orthogonal to a conveyance direction for the printing medium of the inkjet printing apparatus  1 . If the second ink storage member  9  is refilled with the ink in such a state, each of the first ink storage member  8  and the third ink storage member  10  on the respective discharge heads can also be replaced when the refilling is performed. In other words, the user can easily add the ink (refilling and replacement) at a time. Such a configuration can be implemented by, for example, scanning the position of the discharge head on the carriage, when the user refills the second ink storage member  9  with the ink (e.g., when the user inputs an instruction for refilling, or opening of the stopper member is detected by the printing apparatus). Moreover, if the second ink storage member  9  and the discharge head are on the same side, it is easy for the user to can carry out the refilling when replacing each of the first ink storage member  8  and the third ink storage member  10 , i.e., the user can easily add the ink (refilling and replacement) at a time. 
     Meanwhile, the discharge head can be brought to the end portion on the +y side, in the state illustrated in  FIG. 2 . In other words, the second ink storage member  9  and the discharge head are on the opposite sides (the −y side and the +y side), in the y direction of the inkjet printing apparatus  1 . If the second ink storage member  9  is refilled with the ink in such a state, the ink does not easily attach to the discharge head, the first ink storage member  8 , and the third ink storage member  10 , when the second ink storage member  9  is refilled with the ink. Moreover, if the second ink storage member  9  and the discharge head are on the opposite sides, for example, the user can be prevented from replacing the first ink storage member  8  or the third ink storage member  10  by mistake, when refilling the second ink storage member  9  with the ink. Similarly, the user can be prevented from carrying out the ink refilling by opening the stopper member of the second ink storage member  9  by mistake, when trying to replace the first ink storage member  8  or the third ink storage member  10 . In this respect, it is desirable to make it difficult for the user to access the discharge head when the user refills the second ink storage member  9  with the ink, in both of the case where the second ink storage member  9  and the discharge head are on the same side in the y direction and the case where the second ink storage member  9  and the discharge head are on the opposite sides in the y direction. For example, it is desirable to provide such a configuration that the discharge head, the first ink storage member  8 , and the third ink storage member  10  are covered with, for example, a member of the housing, when the user refills the second ink storage member  9  with the ink. Similarly, it is desirable to provide such a configuration that the second ink storage member  9  is covered with, for example, a member of the housing, when the user replaces the first ink storage member  8  or the third ink storage member  10 . 
     Another configuration of the inkjet printing apparatus will be described.  FIG. 6A  illustrates the ink storage members on the carriage in a manner similar to  FIG. 5 . Specifically, in  FIG. 6A , the first ink storage member  8  and the third ink storage member  10  are provided on the carriage  21 . The first ink storage member  8  is an ink cartridge not having an ink refilling port and detachable from the inkjet printing apparatus  1 . The third ink storage member  10  includes four storage members  10 Y,  10 M,  10 C, and  10 Bk that store yellow ink, magenta ink, cyan ink, and black ink, respectively. The third ink storage member  10  is connected to the second ink storage member (not illustrated) within the housing  2  by the tube  18 . The second ink storage member is a storage member having an ink refilling port such as the one described with reference to  FIGS. 4A and 4B , and has four ink storage portions corresponding to the respective colors. The second ink storage member is provided with four ink refilling ports for the respective ink storage portions, and can be refilled with the ink for each color from an ink bottle. The first ink storage member  8  stores ink of color different from the above-described four colors. The discharge head  16  common to the storage members  10 Y,  10 M,  10 C, and  10 Bk is provided at a lower part of the third ink storage member  10  in the gravitational direction. The third ink storage member  10  and the discharge head  16  are not integral with each other, and the third ink storage member  10  can be removed for detachment/attachment or for replacement, independently of the discharge head  16 . The discharge head (not illustrated) is provided at the lower part of the first ink storage member  8  in the gravitational direction as well. The discharge head at the lower part of the first ink storage member  8  in the gravitational direction is integral with the first ink storage member  8  similar to the one illustrated in  FIG. 4B . 
       FIG. 6B  illustrates a configuration basically similar to that in  FIG. 6A . However, in  FIG. 6B , the discharge head at the lower part of the first ink storage member  8  in the gravitational direction and the discharge head at the part lower of the third ink storage member  10  in the gravitational direction form the common discharge head  16 . In this example, the first ink storage member  8  and the discharge head  16  are not integral with each other, and the first ink storage member  8  can also be removed for attachment/detachment independently of the discharge head  16 , as with the third ink storage member  10 . Further, the first ink storage member  8  in this example is connected to the second ink storage member (not illustrated) having a refilling port by the tube  18 , as with the third ink storage member  10 . Such a configuration makes the carriage  21  smaller than that in the configuration illustrated in  FIG. 6A , so that the size of the entire inkjet printing apparatus is easily reduced. However, because the discharge head  16  common to the ink storage members is used, it is necessary to replace the discharge head  16  collectively including portions that discharge ink of all colors, even if replacement of the discharge head  16  is necessary for only a portion that discharges ink of a certain color. 
     In the configuration in  FIG. 6A , the second ink storage member is omitted, but the second ink storage member is present on the right side in  FIG. 6A . In other words, when viewed from the second ink storage member, the third ink storage member  10  is disposed at a closer position to the second ink storage member than the first ink storage member  8 . The first ink storage member  8  is an ink cartridge, but it is necessary to provide a supply path for ink such as a tube between the second ink storage member and the third ink storage member  10 , and thus evaporation of moisture from the supply path is conceivable. Therefore, the third ink storage member  10  is provided at a closer position to the second ink storage member than the first ink storage member  8 , so that the distance from the second ink storage member to the third ink storage member  10  can be as short as possible. In other words, the amount of evaporation of moisture in the ink from the supply path can be small. 
     In the configuration illustrated in  FIG. 6B  as well, the second ink storage member is present on the right side in  FIG. 6B . As illustrated in  FIG. 6B , in a case where the first ink storage member  8  and the third ink storage member  10  are on the same discharge head  16 , it is desirable to provide the third ink storage member  10  at a closer position to the second ink storage member than the first ink storage member  8 , in terms of inhibition of the evaporation of the moisture. 
     Yet another configuration of the inkjet printing apparatus according to the present exemplary embodiment will be described.  FIG. 7  schematically illustrates each of the ink storage members. In  FIG. 7 , the carriage  21  and the ink storage members on the carriage  21  are illustrated in a manner similar to  FIG. 5 , at a center of  FIG. 7 . The third ink storage member  10  and a fourth ink storage member  22  are provided on the carriage  21 . The third ink storage member  10  includes the four storage members  10 Y,  10 M,  10 C, and  10 Bk that store yellow ink, magenta ink, cyan ink, and black ink, respectively. The discharge head at the lower part of the third ink storage member  10  in the gravitational direction and that of the fourth ink storage member  22  form the common discharge head  16 . Each of the storage members can be detached independently of the discharge head  16 . The third ink storage member  10  is connected to the second ink storage member  9  within the housing  2  by the tube  18 . The second ink storage member  9  includes four storage members  9 Y,  9 M,  9 C, and  9 Bk that store yellow ink, magenta ink, cyan ink, and black ink, respectively. In other words, the storage members  10 Y,  10 M,  10 C, and  10 Bk are connected to the storage members  9 Y,  9 M,  9 C, and  9 Bk, respectively, by the respective tubes  18 . The storage members  9 Y,  9 M,  9 C, and  9 Bk are provided with ink refilling ports  9 Ya,  9 Ma,  9 Ca, and  9 Bka, respectively, and can each be refilled with the ink from the ink bottle  20 . The ink bottle  20  also includes four types of ink bottles  20 Y,  20 M,  20 C, and  20 Bk. The fourth ink storage member  22  is connected to the first ink storage member  8  via the tube  18 . The first ink storage member  8  is also provided inside the housing  2 . The first ink storage member  8  can be detached from the inkjet printing apparatus  1 , by pulling out the first ink storage member  8  from a leading end portion  23  of the tube  18 . In other words, the first ink storage member  8  in this example is also an ink cartridge detachable from the inkjet printing apparatus  1 . Neither of the first ink storage member  8  and the fourth ink storage member  22  is provided with an ink refilling port. Therefore, evaporation of moisture from the ink can be further inhibited. According to this configuration, the first ink storage member  8  can be replaced by being detached from the inkjet printing apparatus  1 , even during discharge of the ink (printing) by the discharge head  16 . Although the fourth ink storage member  22  stores the ink that is hard to increase on the carriage  21 , the amount of this ink can be increased in the outside of the fourth ink storage member  22 , by providing the first ink storage member  8 . 
     The ink stored in the first ink storage member and the ink stored in the second ink storage member will be described. The ink stored in each of the storage members is not limited to a particular type. However, because the first ink storage member is an ink cartridge not having an ink refilling port, and the second ink storage member is a storage member having an ink refilling port, there is ink desirable as the ink to be stored, in consideration of the characteristics of each of the storage members. This will be described in detail below. 
     The ink stored in the first ink storage member is first ink, and the ink stored in the second ink storage member is second ink. The first ink storage member is an ink cartridge not having an ink refilling port, and thus evaporation of moisture does not easily progress. Therefore, it is desirable for the first ink storage member to store ink that may readily affect an image to be printed due to the evaporation of the moisture. Examples of such ink include ink having a high viscosity. In the case of an ink set including a plurality of kinds of ink, it is desirable that the first ink be ink having the highest viscosity, and the second ink be ink having a viscosity lower than that of the first ink. Ink adhesion (agglomeration of the color material) of pigment ink containing a pigment as a color material more easily progresses due to evaporation of moisture than that of dye ink containing dye as a color material, and thus easily affects an image to be printed. Therefore, it is desirable that the first ink be the pigment ink, and the second ink be the dye ink, in the case of the ink set. 
     Further, it is desirable to provide such a configuration that ink having a high sedimentation rate of a color material is stored in an ink cartridge, so that the ink cartridge can be removed for stirring or for replacement if the color material settles. At least the first ink storage member is an ink cartridge. In a case where the second ink storage member is not an ink cartridge, the first ink is ink having a high sedimentation rate of a color material, and the second ink is ink having a lower sedimentation rate of a color material than the first ink, in the ink set. Examples of the ink having the high sedimentation rate of the color material include ink using a color material having a high specific gravity, ink using a color material having a high density, and ink using a color material having a large number average particle size. In other words, it is desirable that the first ink be ink using a color material having the highest specific gravity, ink using a color material having the highest density, or ink using a color material having the largest number average particle size, in the ink set. Examples of such first ink include white ink containing titanium oxide as a color material and metallic ink containing a colloid of gold or silver as a color material. In this case, it is desirable that the second ink be black ink or color ink (cyan, magenta, and yellow ink). Further, in a case where such ink having the high sedimentation rate of the color material is used as the first ink, it is desirable to provide a stirring mechanism (e.g., a stirring plate) for stirring the ink, in the ink storage portion of the first ink storage member. 
     One type of inkjet printing apparatus adds a reactant that reacts with cyan, magenta, yellow, and black ink, before or after applying the ink to a printing medium. The reactant has the property of agglomerating a color material in the ink and can improve fixability of a printed image. The amount of consumption of such a reactant is large, and thus it is desirable to provide a refilling port in a storage member for storing the reactant. Moreover, the reactant is generally colorless, and has a less serious issue concerning evaporation. Therefore, it is desirable to store the reactant in a storage member having a refilling port (the second ink storage member), and store ordinary ink of color such as cyan, magenta, yellow, and black ink in a storage member not having a refilling port (the first ink storage member). The second ink storage member that stores the reactant may have a configuration for supplying the reactant to an application member different from the discharge head such as an application roller, instead of the discharge head. 
     While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.