BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of an ink container in First Embodiment of the present invention.
FIG. 2A is a perspective view of an outer appearance of the ink container in First Embodiment of the present invention, and FIG. 2B is an exploded view of the ink container in First Embodiment of the present invention.
FIG. 3A is a sectional view of a press-contact member provided to the ink container shown in FIG. 1, and FIG. 3B is a top view of the press-contact member provided to the ink container shown in FIG. 1.
FIG. 4 is a sectional view of a major portion for illustrating connection between the ink container shown in FIG. 1 and a small flow rate recording head.
FIGS. 5A to 5C are sectional views for illustrating pigment settling at an inner portion of the press-contact member provided to the ink container shown in FIG. 4, wherein FIG. 5A shows a state after a stirring operation, FIG. 5B shows a state after a suction refreshing operation, and FIG. 5C shows a state after the ink container is subjected to the suction refreshing operation and then is left standing.
FIG. 6A is an area distribution view of a contact surface between the press-contact member and a filter, and FIG. 6B is an area distribution view at a contact surface between a press-contact member and a filter in the case where a non-contact area between the press-contact member and the filter is larger than that between the press-contact member and the filter shown in FIG. 6A.
FIG. 7A is a sectional view of a major portion for illustrating connection between the ink container shown in FIG. 1 and a large flow rate recording head, and FIG. 7B is an area distribution view at a contact surface between the press-contact member of the ink container shown in FIG. 7A and a filter.
FIG. 8A is a sectional view of a major portion for illustrating connection between the ink container shown in FIG. 1 and a medium flow rate recording head, and FIG. 8B is an area distribution view at a contact surface between the press-contact member of the ink container shown in FIG. 8A and a filter.
FIG. 9A is a sectional view of a major portion for illustrating connection between a conventional ink container and a small flow rate recording head, FIG. 9B is a sectional view for illustrating pigment settling at an inner portion of a press-contact member of the conventional ink container after a suction refreshing operation, and FIG. 9C is a sectional view for illustrating pigment settling at an inner portion of the press-contact member of the conventional ink container after the conventional ink container is subjected to the suction refreshing operation and then is left standing.
FIGS. 10A to 10C are to views each showing a press-contact member used in an embodiment of the present invention.
FIG. 11 is a perspective view showing an ink jet recording apparatus in an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinbelow, embodiments of the present invention will be described in detail with reference to the drawings.
First Embodiment
FIG. 1 is a sectional view of an ink container according to this embodiment of the present invention, and FIGS. 2A and 2B are perspective views of the ink container of this embodiment. FIG. 1 shows a sectional view taken along A-A line shown in FIG. 2A.
An ink container T00 is a container for containing or accommodating ink T05 and has a casing thereof constituted by a container body T01 and a cap member T02 as shown in FIG. 2A. At a bottom surface of the ink container T00 with respect to a gravitational direction, an ink supply portion T03 for supplying the ink T05 to a recording head is provided.
Inside the ink container T00, as shown in FIG. 1, an ink reservoir chamber T04 for containing the ink T05 is provided. The ink reservoir chamber T04 has an inner constitution as shown in FIG. 2B. Referring to FIG. 2B, the ink container T00 is constituted by the container body T01 and a cap member T16. At an inner wall surface of the container, a coil spring T12 is provided and presses a flexible sheet member T11 to expand the ink reservoir chamber T04, thus generating negative pressure for holding the ink. Further, inside the ink reservoir chamber T04, a stirring member (mechanism) 13 for uniformizing a concentration when a concentration gradient is caused by settling of a settling component of the ink T05 in the ink reservoir chamber T04 is provided. The stirring member T13 is supported by a supporting member T14 provided inside the container and swung by movement of a carriage to which the ink container T00 is mounted, thus performing a stirring operation of the ink in the container. In this embodiment, the stirring member T3 has a plate-like shape but the shape thereof is not limited to the plate-like shape.
At the bottom surface of the ink reservoir chamber T04 with respect to the gravitational direction, the ink supply portion T03 is provided and constitutes a flow passage which communicates with the recording head by contact with a supply passage leading to the recording head. The ink supply portion T03 is provided with a meniscus-forming member T07 and a press-contact member T06 as shown in FIG. 1. The inside of the ink reservoir chamber T04 is kept at negative pressure. In this state, the meniscus-forming member T07 functions as a member for forming a meniscus by the ink T05 so as not to suck air bubbles from the outside of the container into the inside of the ink reservoir chamber. More specifically, a member such that it can generate a meniscus-holding pressure larger than a maximum of the negative pressure generated in the ink reservoir chamber is selected. The press-contact member T06 is constituted by a material having flexibility to some extent so as to absorb positional deviation with respect to a contact direction when the press-contact member T06 is connected to an ink supply port leading to the recording head, and the press-contact member T06 is a member having a capillary force so that it can form a flow passage of the ink T05 during the connection. In this embodiment, the press-contact member T06 is, e.g., constituted by a resinous fiber assembly. An opening of the ink supply portion T03 has a relatively large opening (planar) area capable of meeting an increase in ink flow rate as described later.
FIGS. 3A and 3B are schematic views for illustrating a shape of the press-contact member T06, wherein FIG. 3A is a side view with respect to a longitudinal direction and FIG. 3B is a bottom view. Referring to these figures, reference symbols SA1 to SA3 represent ink conducting areas or regions in which the ink is movable in the press-contact member from the ink container toward the recording head in an ink supplying direction. Reference symbols SB1 and SB2 are non-conducting areas or regions in which the ink from the conducting area (e.g., SA1 or SA3) cannot enter the non-conducting area (e.g., SB1 or SB2). In FIG. 3B< a reference symbol SF represents a size and position of a filter H01 provided to an ink introducing portion H02 of the recording head to which the ink container is mounted. More specifically, the reference symbols SF represents a size and position of an area of the filter H01 of the recording head contacting the press-contact member in the ink supply passage leading to the recording head.
The ink conducting areas SA1 to SA3 are, as described above, areas constituting a flow passage for moving the ink T05 toward the recording head side when the ink container is connected to the recording head. Further, the ink conducting areas SA1 to SA3 have, as particularly shown in FIG. 3B, boundaries therebetween constituted by the ink non-conducting areas SB1 and SB2 in which the ink cannot be moved.
The ink non-conducting areas SB1 and SB2 are formed by sandwiching a flat plate-like press-contact member T06 between processing hones and heat-fusing the press-contact member while compressing the press-contact member, followed by cooling for solidification. That is, of areas constituting the press-contact member, the ink non-conducting area is an area by which an area in which the ink is movable in the ink supply direction toward the recording head is separated. As means for fusing the press-contact member, in this embodiment, an impulse heater capable of rapid heating and rapid cooling is used. However, the fusing means is not limited to the impulse heater but may also employ fusing by frictional heat such as ultrasonic wave. The heat-fusing by the processing hones may be performed only in one direction with respect to the press-contact member and is only required to prevent movement of the ink between the ink conducting areas. The shape of the ink non-conducting area is only required to continuously extend in a direction intersecting a flow direction (indicated by arrows) of the ink from an end of the press-contact member toward the ink supply port as shown in FIG. 3B, and the press-contact member accepts any width and shape.
The ink non-conducting areas SB1 and SB2, as shown in FIG. 3B, define the ink conducting area SA2 contacting the filter SF of the recording head-side supply passage so as to have a proper planar area. Herein, the proper planar area means a planar area in which all the ink held in an area (the ink conducting area SA2 in this embodiment) for leading the ink through the filter of the recording head can be removed.
FIG. 4 is a schematic view showing a mounting state when the ink container of this embodiment is mounted to a printer employing a recording head providing a relatively small ink flow rate and is an enlarged sectional view of a connecting portion as seen in a side direction.
As shown in FIG. 4, the ink container T00 is connected to a recording head H00 so that the ink supply portion T03 communicates with an ink introducing portion H02 located at an upper portion of the recording head H00 with respect to a gradational direction (downward direction) for the ink reservoir chamber T04. The ink introducing portion H02 is formed at an end portion of the ink flow passage H03 and provided with the filter H01. The ink introducing portion H02 and the ink flow passage H03 constitute an ink supply passage with respect to the recording head. The ink communication between the ink container T00 and the recording head H00 is performed by contact of the bottom of the press-contact member T06 with the filter H01 of the recording head H00.
In the case shown in FIG. 4, the filter H01 has a small planar area, so that the filter H01 contacts only the ink conducting area SA2. As a result, only the ink conducting area SA2 constitutes a flow passage capable of supplying the ink to the recording head H00. That is, the ink held at the press-contact member end portion is constituted so as not to enter the recording head side by the ink non-conducting areas SB1 and SB2. The ink T05 held in the ink conducting areas SA1 and SA3 which do not contact the filter H01 is constituted so as not to enter the ink flow passage H03 through the filter H01.
Next, action of the above constituted ink container of this embodiment will be described.
FIGS. 5A to 5C show the ink container of this embodiment and are sectional views for illustrating behavior of ink increased in concentration by settling particles during settling of pigment particles. Further, FIGS. 9A to 9C are sectional views for illustrating ink behavior in a conventional ink container provided with a press-contact member. In the following, the action of the ink container of this embodiment will be described while comparing the ink behavior of the ink container of this embodiment with the ink behavior of the conventional ink container.
FIG. 5A and FIG. 9A each shows a state after a stirring operation of an associated ink container in a printer of this embodiment. The stirring operation performs stirring of the ink by swing of the stirring member T13 shown in FIG. 2B provided in the ink container during scanning of the carriage for the printer (recording apparatus). FIG. 9A shows a settling state of ink pigment particles in the conventional ink container. In this state, the ink T05 in the ink container has a uniform concentration as indicated by broken lines. When the ink container T00 in which the settling of the pigment component results in an advance stage is moved by the carriage to stir the ink T05 in the ink container, the concentration of the ink is uniformized. However, the ink held in the press-contact member T06 indicated by crossed oblique lines is not affected by the stirring, so that the concentration of the ink is not uniformized. For this reason, as shown in FIGS. 5A and 9A, pigment-settled ink T08 still remains in the press-contact member T06.
FIGS. 5B and FIG. 9B each illustrates a settling state of the ink in the ink container immediately after a suction operation is performed by the printer. In the case of the ink container of this embodiment, as shown in FIG. 5B, the settling ink T08 in the ink conducting area SA2 with which the filter H01 is brought into contact is removed by the suction operation. As a result, the concentration-uniformized ink T05 present in the ink container T04 indicated by the broken lines in FIG. 5B is introduced into the ink conducting area SA2 of the press-contact member T06 after the suction operation is completed (indicated by dotted portion in FIG. 5B). In other ink conducting areas SA1 and SA3 with which the filter H01 is not brought into contact, the settling ink T08 still remains without being removed (indicated by the crossed oblique lines in FIG. 5B).
On the other hand, in the conventional ink container provided with the (conventional) press-contact member, as shown in FIG. 9B, the settling ink T08 is removed in an area in which flow of ink in a direction indicated by an arrow B is caused by the suction operation. As a result, into the area (indicated by dotted portion of FIG. 9B), the concentration-uniformized ink T05 in the ink reservoir chamber T04 flows. However, into areas constituting both end portions of the press-contact member T06, the ink T05 does not flow, so that the high concentration ink still remains in the areas (indicated by the crossed oblique lines in FIG. 9B) of the press-contact member T06.
FIGS. 5C and 9C each illustrates a settling state of the ink in the ink container when the ink container is left standing for several hours from the state shown in FIG. 5B or FIG. 9B. That is, FIGS. 5C and 9C each illustrates a settling state of the ink in the ink container after the ink container is subjected to the suction operation and then is left standing for several hours.
As shown in FIG. 9C, in the conventional ink container provided with the press-contact member, the settling ink T08 which has not been removed by the suction operation gradually diffuse in directions indicated by arrows C1 and C2 when the ink container is left standing for several hours after the suction operation. As a result, the ink containing the settled pigment particles is supplied to the recording head H00 through the ink flow passage H03 and ejected from the recording head H00 to adversely affect a recording quality, thus causing (image) density non-uniformity or the like in some cases.
On the other hand, in the ink container T00 of this embodiment, the settling state of the ink is shown in FIG. 5C. More specifically, the settling ink T08 remaining in the ink conducting areas SA1 and SA3 is blocked from flowing into the recording head H00 by the ink non-conducting areas SB1 and SB2. As a result, the ink having a non-uniform colorant concentration such as a high colorant concentration is caused to remain in the ink conducting areas SA1 and SA3. Therefore, it is possible to prevent supply of the high concentration ink to the recording head H00.
As described above, in order to obviate the influence of the ink having the non-uniform colorant concentration on a recording quality, it is desirable that the ink conducting area SA2 contacting the filter H01 has a size capable of removal of all the ink held in the ink conducting area SA2 by the suction operation. This is because the high concentration ink can be removed by the suction operation even when the high concentration ink remains in the ink conducting area SA2. With reference to FIGS. 6A, 6B, 7A and 7B, an experimental embodiment for determining optimum positions of the ink non-conducting areas SB1 and SB2 defining the size of the ink conducting area SA2 will be described.
FIGS. 6A and 6B are bottom views of a press-contact member T06 subjected to the experimental embodiment. FIG. 6A shows a press-contact member in which an ink conducting area SA2 is designed so that a planar areal ratio between a contact area SF with the filter H01 and a non-contact area SH with the filter H01 is set to satisfy SF:SH=1:1.3. FIG. 6B shows a press-contact member in which an ink conducting area SA2 is designed so that a planar areal ratio between the contact area SF and the non-contact area SH is set to satisfy SF:SH=1:2.
Each of the above designed two types of the press-contact members T06 is incorporated into an ink container T00 filled with ink corresponding to high concentration ink in which pigment particles are placed in an advanced settling state. Each of the resultant ink containers is mounted to a printer to which a recording head H00 provided with the filter H01 having the contact area SF is also mounted, and is subjected to stirring and a suction operation.
Prints obtained by recording immediately after the stirring and the suction operation (“after stirring”) and prints obtained by recording after the ink container was subjected to the stirring and the suction operation and was then left standing for 3.5 hours at 60° C. (“after standing”) were prepared. Each of the thus prepared prints was compared with a print obtained by recording with fresh ink having a uniform pigment concentration to evaluate a state of (image) density non-uniformity. More specifically, images obtained by the recording were compared at each of density levels from 0 to 32 to determine a color difference ΔE at a predetermined point. The color difference ΔE means a difference in color between two colors in a color space and can be obtained as a numerical value on the basis of a calorimetric system such as Munsell calorimetric system, L*a*b* calorimetric system, L*C*h* calorimetric system, Hunter Lab calorimetric system, or XYZ calorimetric system. When the difference in color (ΔE) between two colors obtained from the calorimetric system is smaller, a better image is obtained. When the color difference (ΔE) is larger, a resultant image is worsened by eye observation. In this experimental embodiment, when ΔE exceeds 6, the image is judged as a no-good image.
The evaluation results are shown in Table 1.
TABLE 1
|
|
Press-contact member
After stirring
After standing
|
|
SF:SH = 1:1.3
Excellent
Excellent
|
SF:SH = 1:2
Excellent
Good or Fair
|
|
As a result of the experimental embodiment described above, it is confirmed that a lowering in recording quality in terms of density non-uniformity is not caused at a certain areal ratio or less. In the ink container of this embodiment, as shown in Table 1, it has been confirmed that it is possible to effect good recording when the planar area ratio between the non-contact area SH of the filter H01 with the ink conducting area SA2 and the contact area SF of the filter H01 with the ink conducting area SA2 is SF:SH=1:1.3 or less. The above experimental results vary depending on differences in setting factors such as a suction performance of a printer in terms of the used ink, so that the SF:SH ratio may appropriately be changed depending on the factors.
FIGS. 7A and 7B are schematic views for illustrating a connection state in the case where the ink container of this embodiment is used in a connection state with a recording head providing an expected maximum flow rate. That is, these figures show the case where the ink container of this embodiment is connected to a recording head providing an ink supply amount larger than that provided by the recording head shown in FIG. 4 and then is used. FIG. 7A is an enlarged sectional view of a connecting portion, and FIG. 7B is a schematic view showing area distribution at a contact surface between the press-contact member and a filter of the recording head when the ink container is connected to the recording head.
As shown in FIG. 7A, the filter H01 of the recording head H00 contacts each of the ink conducting areas SA1 to SA3 of the press-contact member T06 while being in non-contact with the ink non-conducting areas SB1 and SB2. In this case, area distribution of the press-contact member T06 is shown in FIG. 7B.
The contact area SF of the filter H01 is separated by the ink non-conducting areas SB1 and SB2. More specifically, contact areas SF1, SF2 and SF3 are located in the ink conducting areas SA1, SA2 and SA3, respectively. In this case, non-contact areas SH1, SH2 and SH3 are located adjacent to the contact areas SF1, SF2 and SF3, respectively. By applying the above described experimental results to this case, sizes of the press-contact member T06 and the filter H01 and determined so that planar areal ratios, for the ink conducting areas SA1 to SA3, between contact areas SFn (n=1, 2 and 3) and non-contact areas SHn (n=1, 2 and 3) satisfy SFn:SHn=1:1.3 or less. As a result, even when the recording head contacting the press-contact member is changed, it is possible to ensure commonalty of the ink container of this embodiment with respect to the recording heads before and after the change. Incidentally, the filter H01 has portions corresponding to the ink non-conducting areas SB1 and SB2 of the press-contact member. These portions are ineffective areas, so that it is necessary to design the filter H01 in consideration of these ineffective portions.
FIGS. 8A and 8B are schematic views showing a press-contact member contacting a recording head providing a medium flow rate between the expected maximum flow rate provided by the recording head (FIGS. 7A and 7B) and the small flow rate given by the recording head (FIG. 4). That is, these figures show a connection state in the case where the ink container of this embodiment is connected to the recording head. FIG. 8A is an enlarged sectional view of a connecting portion, and FIG. 8B is a schematic view showing area distribution at a contact surface between the press-contact member and a filter of the recording head when the ink container is connected to the recording head.
As shown in FIG. 8A, the filter H01 of the recording head H00 contacts each of the ink conducting areas SA2 and SA3 of the press-contact member T06 while being in non-contact with the ink non-conducting area SB2. In this case, area distribution of the press-contact member T06 is shown in FIG. 8B.
The contact area SF of the filter H01 is separated by the ink non-conducting area SB2. More specifically, contact areas SF2 and SF3 are located in the ink conducting areas SA2 and SA3, respectively. In this case, non-contact areas SH2 and SH3 are located adjacent to the contact areas SF2 and SF3, respectively. By applying the above described experimental results to this case, sizes of the press-contact member T06 and the filter H01 and determined so that planar areal ratios, for the ink conducting areas SA2 and SA3, between contact areas SFn (n=2 and 3) and non-contact areas SHn (n=2 and 3) satisfy SFn:SHn=1:1.3 or less. As a result, even when the recording head contacting the press-contact member is changed, it is possible to ensure commonality of the ink container of this embodiment with respect to the recording heads before and after the change. Incidentally, the filter H01 has portion corresponding to the ink non-conducting area SB2 of the press-contact member. This portion is an ineffective area, so that it is necessary to design the filter H01 in consideration of this ineffective portion similarly as in the above case described with reference to FIGS. 7A and 7B.
Other Embodiments
In First Embodiment described above, the shape of the ink non-conducting areas SBn is a linear shape in order to minimize the ineffective area of the filter H01 when the large (maximum) flow rate-recording head is connected to the press-contact member. However, in the present invention, the shape of the ink non-conducting areas is not limited to the linear shape.
For example, the shape may be an elongated looped shape such that an ink non-conducting area SB1 is closed as shown in FIG. 10A. Further, the ink non-conducting areas may also be arc-shaped ink non-conducting areas SB1 and SB2 as shown in FIG. 10B.
The number of the ink non-conducting areas SBn is 2 in First Embodiment in order to realize commonality of the ink container with respect to the above described three types of the recording heads but is not limited to 2 in the present invention. As shown in FIG. 10C, the number of the ink non-conducting areas is increased, whereby it is possible to ensure commonality of the ink container with respect to more types of recording heads.
In First Embodiment the ink container is used for containing the pigment ink but the ink used in the present invention is not limited to the pigment ink. Even in the case of an ink container containing ink using a dye as a colorant, e.g., viscosity-increased ink can adversely affects a recording result. More specifically, as described with reference to FIGS. 9A to 9C, all the dye ink in the press-contact member cannot be removed by suction in some cases. For example, the dye ink remaining in the press-contact member is increased in viscosity and thereafter flows into the recording head side, so that density non-uniformity can occur in a recording image. Thus, the use of the press-contact member to which the present invention is applied is preferable also in an ink container for containing ink in general in addition to the pigment ink.
FIG. 11 is a schematic view for illustrating a constitutional embodiment of an ink jet recording apparatus capable of employing the above described ink container and recording head.
Referring to FIG. 11, the ink jet recording apparatus of this embodiment is constituted by an apparatus main assembly, a sheet-feeding portion, a sheet discharge tray, etc. The apparatus main assembly is, as shown in FIG. 11, constituted by a chassis M3019, a recording operation mechanism, and the like. The recording operation mechanism includes a carriage M4001 which is reciprocable in a main scanning direction indicated by a double-pointed arrow A. To the carriage M4001, an ink container containing ink and an ink jet recording head capable of ejecting the ink supplied from the ink container through a plurality of ink ejection outlets are mounted. The ink container is constituted separably from the recording head and can be replaced with a new ink container when an amount of the ink contained in the ink container becomes small. The recording head is capable of ejecting the ink by using, e.g., an electrothermal transducer (heater) or a piezoelectric element. In the case of using the electrothermal transducer, ink is caused to generate bubbles by heat generation of the electrothermal transducer, so that it is possible to eject the ink through the ink ejection outlets by utilizing bubble generation energy. A recording sheet (recording medium) fed from the sheet-feeding portion is conveyed in a sub-scanning direction indicated by an arrow B.
When an image is recorded on the recording sheet, a recording operation and a conveying operation are repeated. In the recording operation, the recording head ejects the ink from the ink ejection outlets while moving together with the carriage M4001 and the ink container in the main scanning direction. In the conveying operation, the recording sheet is conveyed in a predetermined amount in the sub-scanning direction. By repeating the recording operation and the conveying operation, an image is successively recorded on the recording sheet.
At one end portion of a movement path of the carriage M4001, a refreshing unit is provided and performs operations of wiping, preliminary ejection, and suction. By these operations, it is possible to maintain an ejection performance of the recording head in good condition. A suction amount by the suction operation is, as described above, designed so that all the ink held in the ink conducting area can be removed depending on a planar area of the ink conducting area in the press-contact member T06.
As described above, the ink container according to the present invention includes the press-contact member at the ink supply portion and is constituted so that the ink container can be used in common with respect to recording heads different in flow rate. By realizing commonality of the press-contact member, it is possible to cut out the need of development of an ink container for each development of a new recording head in terms of an ink flow rate (supply amount). Thus, it is possible to reduce development cost and investment in plant and equipment. As a result, it is possible to reduce production cost of the ink container, so that an inexpensive ink can be provided.
While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth and this application is intended to cover such modifications or changes as may come within the purpose of the improvements or the scope of the following claims.
This application claims priority from Japanese Patent Application No. 246045/2006 filed Sep. 11, 2006, which is hereby incorporated by reference.
Patent Application
20080062231
