Inkjet printer and printing head capping method

An inkjet printer has a printing head having a nozzle surface on which a plurality of nozzles are located that spray a plurality of kinds of ink and a cap that covers the nozzle surface of the printing head. This cap includes a ring-shaped seal lip that is constructed so that the tip end thereof comes in contact with the nozzle surface to perform capping and a partitioning lip that partitions the area inside the seal lip into areas for nozzle groups that correspond to the kinds of ink. The tip end of either seal lip or partitioning lip is shaped so that it is compressed more easily than that of the other.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Nonprovisional application claims priority under 35 U.S.C. §119(a) on Patent Applications No. 2005-375127 filed in Japan on Dec. 27, 2005, and No. 2006-134217 filed in Japan on May 12, 2006, the entire contents of which are hereby incorporated by reference.

BACKGROUND

This invention relates to an inkjet printer and a capping method for covering the nozzle surface of the printing head thereof, and more particularly, to an inkjet printer, which comprises a cap that is capable of maintaining an airtight seal even with a small cap load, and to the capping method for capping the printing head.

In the past, various shapes of caps to be used for capping the printing head of an inkjet printer have been proposed. For example, there is a cap having a protruding ring-shaped seal lip that is formed along the perimeter, and a partitioning lip that divides the inside of the ring-shaped seal lip corresponding to the nozzle groups (see Japanese Patent Application Laid Open No. 2001-80087).

However, when the cap load when covering the nozzle surface with the cap is large, various adverse effects may occur such as deformation of the precisely processed printing portion, for example deformation of the nozzle surface, head holder or the like, and so a small cap load is desired.

SUMMARY

However, in a cap having a partitioning lip inside a ring-shaped seal lip, as in the case of the cap described above, the total length of the lips that actually comes in contact with the nozzle surface when capping becomes long, so the cap load that acts on the nozzle surface becomes large. Furthermore, in the case of an inkjet printer for A3 sized paper, the number of nozzles is increased in order to increase the printing speed, and the nozzle surface of the printing head is formed to be large, so the size of the cap is also increased. Therefore, the total length of the lips that are formed in the cap also becomes long, and thus the cap load that acts on the nozzle surface increases. However, when the cap load is decreased so that the load that presses the cap against the printing head is weakened, there is a problem in that the load on the nozzle surface and head holder is reduced, so the seal between the nozzle surface and the tip ends of the lips is insufficient, and thus the seal made by the cap when capping the printing head decreases. Moreover, by increasing the rigidity of the printing head so that it can withstand the increasing cap load, the weight of the printing head increases, and thus disadvantages occur in that a motor having a large torque must be used for moving the carriage on which the printing head is mounted, design becomes complicated, and the amount of space required for the motor increases.

An object of the present invention is to provide an inkjet printer and printing-head capping method capable of maintaining the cap seal even when the cap load is small, and does not apply a large load on the nozzle surface, head holder, etc.

A first aspect is an inkjet printer, comprising: a printing head having a nozzle surface on which a plurality of nozzles are located that spray a plurality of kinds of ink; and a cap that covers the nozzle surface of the printing head; wherein the cap comprises a ring-shaped seal lip that is constructed so that the tip end thereof comes in contact with the nozzle surface to perform capping; and a partitioning lip that partitions the area inside the seal lip into areas for nozzle groups that correspond to the kinds of ink; and wherein the tip end of either the seal lip or partitioning lip is shaped so that it is compressed more easily than that of the other.

With this inkjet printer, the tip end of either the ring-shaped seal lip or the partitioning lip is deformed easily, and as a result, it becomes easy to absorb the load, so it is possible to reduce the cap load while maintaining a good seal in the cap. And it is possible to perform capping without applying a large load on the nozzle surface, head holder or the like.

A second aspect is an inkjet printer, comprising: a printing head having a nozzle surface on which a plurality of nozzles are located that spray a plurality of kinds of ink; and a cap that covers the nozzle surface of the printing head; wherein the cap comprises: a ring-shaped seal lip that is constructed so that the tip end thereof comes in contact with the nozzle surface to perform capping; and a partitioning lip that partitions the area inside the seal lip into areas for nozzle groups that correspond to the kinds of ink; and wherein the tip end of the seal lip protrudes more than the tip end of the partitioning lip.

With this inkjet printer, it is possible to cap the printing head by bringing just the tip end of the ring-shaped seal lip in contact with the nozzle surface, so it is possible to make the cap load small when storing the nozzles. Therefore, the nozzle surface and head holder are not damaged due to deformation or the like even when the nozzles are stored for a long time.

A third aspect is an inkjet printer, comprising: a printing head having a nozzle surface on which a plurality of nozzles are located that spray a plurality of kinds of ink; and a cap that covers the nozzle surface of the printing head; wherein the cap comprises: a ring-shaped seal lip that is constructed so that the tip end thereof comes in contact with the nozzle surface and cover all of the plurality of nozzles; and a partitioning lip that is located inside the seal lip, and that can separate nozzle groups that spray specified kinds of ink, and cover the nozzle groups; and wherein the cross-sectional shapes of the seal lip and the partitioning lip differ so that the loads that the nozzle surface receives from the seal lip and partitioning lip differ when capped.

With this inkjet printer, by changing the cross-sectional shapes of the seal lip and partitioning lip, for example, by changing the height and width, it is possible to change the contact load on the nozzle surface when capped. With this difference in contact load, it is possible to reduce the cap load when covering the printing head with the cap. Therefore, it is possible to reduce the load on the printing head when capped, and this is particularly effective when storing the nozzles when not printing, and when the printing head is capped for a long period of time such as when not using the printer. The partitioning lip may be located at plural positions.

A fourth aspect is a capping method for capping a printing head in which a cap covers a nozzle surface of a printing head on which a plurality of nozzles that spray a plurality of kinds of ink are located, comprising the steps of: moving the printing head to the position where the cap is located so that the printing head faces the cap; moving the cap toward the printing head; stopping movement of the cap when the tip end of a ring-shaped seal lip, which is formed in the cap, and the tip end of a partitioning lip, which partitions the inside of the seal lip for each kind of ink, come in contact with the nozzle surface when sucking ink from inside of the nozzles, and stopping the movement of the cap in a state where the tip end of the seal lip comes in contact with the nozzle surface, and the tip end of the partitioning lip does not come in contact with the nozzle surface, when storing the nozzles when not printing; and maintaining the cap in this stopped position.

With this method of capping a printing head, in addition to being able to perform purging for each kind of ink, the load acting on the nozzle surface when the nozzles are stored when not printing is mainly just from the ring-shaped seal lip, so when storing the nozzles, it is possible to cap the printing head with a small cap load. Therefore, when the nozzles are stored, the cap load becomes small and the load on the nozzle surface and head holder is reduced, so capping is possible in which damage to the nozzle surface and head holder due to deformation does not occur.

A fifth aspect is a capping method for capping a printing head when not printing in which a cap covers a nozzle surface of a printing head on which a plurality of nozzles that spray a plurality of kinds of ink are located, comprising the steps of: bringing the tip end of a ring-shaped partitioning lip that is located in the cap in contact with the nozzle surface, and covering a nozzle group that sprays an ink that becomes thicker more easily than other ink that is sprayed from the other nozzle groups with the partitioning lip; and bringing the tip end of a ring-shaped seal lip that is located around the partitioning lip in contact with the nozzle surface and covering all of the plurality of nozzles with the seal lip.

With this method of capping a printing head, the tip end of the partitioning lip comes in closer contact with the nozzle surface than the tip end of the seal lip, and the inside of the partitioning lip is covered by both the partitioning lip and seal lip, so it is possible to increase the seal inside the partitioning lip. Therefore, by covering a nozzle group that sprays ink that thickens easily and has low resistance to drying with the partitioning lip having a good seal, it is possible to perform capping in which the contact load between the seal lip and the nozzle surface is suppressed, so it is possible to reduce the cap load, and it is possible to reduce the load on the printing head when capped. This is particularly effective when storing the nozzles when not printing, and when the printing head is capped for a long period of time such as when not using the printer.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The preferred embodiments of the present invention will be described based on the drawings. The embodiments described below are just examples and needless to say it is possible to change the embodiments within a range that does not change the scope of the invention.

FIG. 1is a perspective drawing of a thin-type multi-function peripheral100for A3-sized paper that, in addition to the function of the inkjet printer1of the present invention, has copy, scanning and facsimile functions. At the bottom of this multi-function peripheral100there is a paper-supply tray101that can be pulled out from the front, and the top cover of this paper-supply tray101is a paper-output tray102that receives the output paper. This multi-function peripheral100is a type of multi-function peripheral that supplies paper and outputs paper from the front. Also, at the top of the multi-function peripheral100there is a document-reading apparatus103that is used when making copies, reading images, or sending a facsimile, and on the underneath side thereof there is an inkjet printer1.

On the top surface of the document-reading apparatus103there is a document-platen cover103athat holds a document in place that has been set on the document platen, and an operation panel103b. This document-reading apparatus103can be opened or closed with respect to the bottom section of the multi-function peripheral100, which makes it possible to replace the ink cartridges of the inkjet printer1.FIG. 2is a simplified drawing showing the inside of the inkjet printer1.

InFIG. 2,2is a printing-head unit that includes a printing head that sprays ink to print on the paper. Also,3indicates color ink cartridges for the colors black, magenta, cyan and yellow, where3bis the ink cartridge for black,3mis the ink cartridge for magenta,3cis the ink cartridge for cyan and3yis the ink cartridge for yellow.

The printing-head unit2is fastened to a carriage5. This carriage5is flat in the width direction of a main case6, and is installed to two parallel guide shafts7a,7bon the front and back front and back direction) so that it can freely move back and forth, and the carriage5is driven by a continuous timing belt8that is placed so that the lengthwise direction of the guide shafts7a,7band rotational direction of the timing belt8are parallel. The timing belt8is driven by a drive motor9that is located on the end of the main case6, and it can be driven in either the forward or reverse direction. This timing belt8drives the carriage5, which moves the printing-head unit2that is attached to the carriage5to the right or left along the guide shafts7a,7b.

As shown in the bottom view ofFIG. 3and the cross-sectional view ofFIG. 4, in the printing-head unit2that is fastened to the carriage5, there is a printing head11that is located on the bottom section of a box-shaped head holder10, and there is a buffer tank12and an exhaust means13located on the top side of the printing head11. The bottom surface of the head holder10is open, and the underneath surface of the printing head11is exposed.

The underneath surface of the printing head11is a nozzle surface11a, and nozzle groups that spray each color of ink, or in other words, black ink, yellow ink, cyan ink and magenta ink, are located on the nozzle surface11a. Each nozzle group is arranged so that a plurality of nozzles are arranged in the direction orthogonal to the direction of movement of the printing-head unit2. The two rows of nozzle group14bfor black ink are located in the center, and the nozzle groups for color ink are arranged symmetrically on both sides of it on the left and right, and arranged in order starting from the nearest to the nozzle group14bfor black ink as, the nozzle group14yfor yellow, the nozzle group14cfor cyan and the nozzle group14mfor magenta.

On the other hand, on the bottom section of the main case6, on one end in the width direction, there is a maintenance unit15so that the guide shafts7a,7bare positioned between the projected image that is projected downward. On the side of this maintenance unit15there is a wiper16that wipes and cleans the nozzle surface11aof the printing head11. On the end opposite from the maintenance unit15there is an ink-receiving unit17, and it is such that it can collect ink that is sprayed from the nozzle during flashing (seeFIG. 2).

Next, the maintenance unit15will be explained with reference toFIG. 4. The maintenance unit15comprises a cap18made of an elastic material for covering the nozzle surface11aof the printing head11, and an exhaust cap19for sucking out air bubbles that have accumulated in the exhaust means13. These caps18,19can be selectively raised or lowered by a common raising/lowering means20, and they are connected to one suction pump21by way of one switching valve22. On the exhaust cap19there is a release rod19a, which protrudes upward and is able to push up a valve rod13aof the exhaust means13to open the exhaust means13, and a suction port19b, which sucks air bubbles from the opened exhaust means13. This suction port19band switching valve22are connected by a suction tube23.

On the other hand, the cap10that covers the nozzle surface11aof the printing head11is formed into a long rectangular shape that is long in the direction of placement of the nozzles as seen from the top (seeFIG. 3). As shown inFIG. 5AandFIG. 5B, on this cap18there is a protruding ring shaped seal lip18athat is formed along the edge. Also, on the inside of the ring-shaped seal lip18athere is a protruding ring-shaped partitioning lip18bthat is formed in a rectangular shape that is long in the same direction as the lengthwise direction of the cap18and it surrounds the center section of the inner surface of the cap18.

On the inner surface of the cap18, there is a chamber18dformed on the inside of the partitioning lip18bthat corresponds with the two-row nozzle group14bthat sprays black ink. On both sides of the chamber18d, there are chambers18c,18ethat are formed between the inside surface of the ring-shaped seal lip18aand the outside surface of the ring shaped partitioning lip18b, so that they correspond with the nozzle groups14y,14m,14cfor color ink that are located on both sides of the nozzle group14b. There is a gap formed between the inside surface of the ring-shaped seal lip18aand the outside surface of the ring-shaped partitioning lip18b, so the chambers18cand18eare connected together. Also, on the ends of each of the chambers18cto18ethere are suction ports18fto18hthat connect to one end section of the suction tube24whose other end is connected to the switching valve22.

The seal lip18ais higher than the partitioning lip18b, and the tip end of the seal lip18aprotrudes out further than the tip end of the partitioning lip18b. The tip-end section18kof the partitioning lip18bis formed so that the thickness becomes gradually thinner toward the tip end, and it has a triangular cross-sectional shape with a rounded tip end. Also, the tip end section18jof the seal lip18ais formed so that it is nearly the same thickness from the base to the tip end, and similarly the tip end is rounded. Also, by making the thickness of the tip end section18jof the seal lip18athin, it is more easily compressed than the tip end section18kof the partitioning lip18a. The height of the tip end section18jis set so that it is greater than the height difference between the ring shaped seal lip18aand partitioning lip18b.

This cap18covers the nozzle surface11aof the printing head11, performs purging to suck out the ink from the nozzles on the nozzle surface11a, and stores the nozzles when not printing. When performing purging, the switching valve22switches to the position where the cap18and suction pump21are connected through to each other, and a vacuum is created inside the cap18by the suction pump21. Also, when storing the nozzles, the switching valve22or suction pump21is stopped at a position so that the suction ports18fto18hof the cap18are not connected through to the outside, and when the cap18is in contact with the nozzle surface11a, a sealed space is formed inside the cap18. Especially, when storing the nozzles, only the tip end of the seal lip18aneeds to come in contact with the nozzle surface11a, and since the tip end section18jof the seal lip18ais compressed and deformed easily, it is possible to perform capping with a good seal and small cap load.

The suction ports18fto18hare formed in all of the chambers18cto18einside the cap18, however, since the chamber18cand chamber18eare connected through to each other, it is possible to form a suction port in just one. Also, the partitioning lip18bis ring-shaped, however, it is also possible to connect the portions of the ring-shaped seal lip18bfacing each other.

Next, the method for capping the printing head11with the cap18will be explained with reference toFIGS. 6 to 8. InFIGS. 6 to 8, a cut out part of the cap18is shown.

FIG. 6shows the portion of the raising/lowering means20of the cap18in more detail. InFIG. 6,25is a support platform that supports the cap18from the underneath side and that raising and lowering the cap18, and26is a slider cam that can move back-and-forth in the same direction as the direction of movement of the printing-head unit2, and by this back-and-forth movement is capable of raising or lowering the support platform25. The cap18is located on the top surface of the support platform25, and on the bottom surface of the support platform25is a pair of cylindrical-shaped follower cylinders25athat protrude downward so that they are lined up with the direction of movement of the slider cam26. A pair of follower pins25bare located at opposite locations on the outer surfaces of the follower cylinders25aand protrude in the radial direction of the follower cylinders25a.

On the other hand, the slider cam26comprises a pair of guide pieces26athat are parallel with the direction of movement of the printing-head unit2, and guide holes26bthat guide the follower pins25bof the support platform25are formed in the guide pieces26awith one for each follower cylinder25a. The guide holes26bhave three horizontal sections in the top section, middle section and bottom section of the guide pieces26athat are shifted in one direction of the back-and-forth direction of the slider cam26, and have two inclined sections between the ends of each of the adjacent horizontal sections that connect the horizontal sections into one continuous hole, so that they can switch the position of the support platform25among three levels, a top level, middle level and bottom level. The guide holes26bthat are formed in this way are symmetrically located in the pair of guide pieces26a. These pairs of guide holes26bare such that the pair of follower pins25bof the follower cylinders25acan be inserted in them. The support platform25is constantly being pushed upward by springs (not shown in the figure), and the follower cylinders25aare restricted by guide members (not shown in the figure) so that they can only move in the up/down direction.

When not performing capping, this raising/lowering means20moves the slider cam26to a position where the cap18is lowered, or in other words, to a position where the follower pins25bof the support platform25are held in the bottom horizontal section of the guide holes26a(seeFIG. 6).

Also, as shown inFIG. 6, when performing purging, the timing belt8is driven with the cap18in the lowered state, and moves the carriage5toward the top of the maintenance unit15so that the cap18faces the nozzle surface11aof the printing head11. After that, by sliding the slider cam26, the follower pins25bthat are inserted into the guide holes26bare moved to the top horizontal section of the guide holes26b. By doing that, the support platform25is raised and the tip end of the seal lip18aand the tip end of the partitioning lip18bof the cap18come in close contact with the nozzle surface11a(seeFIG. 7A). In this way, the printing head11is capped and purging is performed.

When purging by the chambers18cto18eof the cap18, the nozzle surface11aof the printing head11is separated according to type of ink that is sucked from the nozzles, or in other words, the group of nozzles14bthat spray black ink, and the groups of nozzles14y,14mand14cthat spray color ink are separated and sealed respectively. Therefore, it is possible to separately suck out the black ink and color ink. In this case, when either the black ink or the color ink is pigment ink, and the other is dye ink, the nozzles may become plugged up if both kinds of ink were allowed to mix and accumulate together inside the cap18, however, by sucking out the ink separately as described above, it is possible to avoid plugging up the nozzles.

Moreover, as shown inFIG. 7B, the tip end section18jof the seal lip18ais compressed and deformed, and the load that acts on the nozzle surface11afrom the seal lip18ais absorbed by this deformation of the tip end section18j. As a result, the cap load that acts on the nozzle surface11ais reduced, and the load on the nozzle surface11aand head holder10that accompanies this capping is reduced.

Nest, capping when storing the nozzles of the nozzle surface11awhen not printing will be explained. The capping method up to the point of performing purging by facing the cap18toward the nozzle surface11aof the printing head11is the same and so is omitted.

After facing the cap18toward the nozzle surface11aof the printing head11, the slider cam26is moved, which moves the follower pins25bfrom the bottom horizontal section to the middle horizontal section of the guide holes26a, and the slider cam26is stopped. When doing that, the cap18is raised, and as shown inFIGS. 8A and 8B, only the tip end of the seal lip18acomes in contact with the nozzle surface11a. On the other hand, the tip end of the partitioning hip18bis separated from the nozzle surface11a. When doing this, it is also possible to have the tip end of the partitioning lip18bcome in light contact with the nozzle surface11aso that no load is applied to the nozzle surface11a.

Therefore, since there is no load from the partitioning lip18bon the nozzle surface11a, the cap load is decreased. Also, the tip end section18jof the seal lip18ais easily deformed, which keeps the load acting on the nozzle surface11alow, so there is a capped state with no load being applied to the nozzle surface11aand head holder10.

As described above, the entire length of the ring-shaped seal lip18ais longer than that of the partitioning lip18b, and as a result the seal lip18aapplies a larger load on the nozzle surface11athan the partitioning lip18b, so by forming the tip end of the seal lip18aso that it is easily compressed, it is possible to reduce the capping load when performing capping. Therefore, since it is possible to further reduce the cap load during capping, it is possible to perform capping that will not damage the nozzle surface11aor head holder10due to deformation or the like.

Also, the shape of the tip end of the seal lip18ais formed so that the thickness is thin and easily compressed, and the tip end section18jof the seal lip18acan be made using simple construction so that it is easily deformable. Therefore, the shape of the cap18is not complex and can be easily manufactured, and as a result, parts can be easily procured.

Moreover, the partitioning lip18bis located inside the ring-shaped seal lip18ain a ring shape, and a gap is formed between the partitioning lip18band seal lip18a, the portion inside the ring-shaped seal lip18aand outside the partitioning lip18bis connected, so ink that is received in the portion outside the partitioning lip18bcan be discharged out of the cap18from a suction port in one location. Therefore, together with being possible to reduce the number of suction ports that are formed in the cap18and simplify the construction of the cap18, it is possible to omit a discharge means such as a tube for discharging the ink that is received in the cap18, which makes it possible to simplify the internal construction of the printer.

As shown inFIG. 9B, when a depressions11bthat corresponds to the tip end section18jof the seal lip18ais formed in the nozzle surface11a, it is possible to reduce the amount of compression (deformation) of the tip end section18jwhen the seal lip18ais brought into contact with the nozzle surface11a. As a result, the load from the seal lip18aacting on the nozzle surface11ais reduced, and thus it is possible to reduce the cap load when purging. In addition, it is possible to reduce the load on the lips. Also, when performing capping by bringing both the seal lip18aand the partitioning lip18bin contact with the nozzle surface11a, the load acting on the nozzle surface11afrom the seal lip18ais reduced, so it is possible to suppress the cap load. Moreover, together with being able to increase the life of the tip end of seal lip18a, it is possible to perform purging with no load on the nozzle surface11aand head holder10.

Besides the shape of the cap18of the embodiment described above, the following shapes could also be used. The cap18shown inFIG. 10Ais a cap in which the height of the seal lip18aand the partitioning lip18bis the same, and the cap18shown inFIG. 10Bis a cap in which the shape of the tip end of the seal lip18aand that of the partitioning lip18bhave been switched with each other.

In these caps18, the tip end section18jof the seal lip18aor the tip end section18kof the partitioning lip18bis easily compressed, so capping is possible with a small cap load and without losing any seal. Particularly, as shown inFIG. 10A, the entire length of the seal lip18ais longer than that of the partitioning lip18band as a result the seal lip18aapplies a larger load on the nozzle surface11athan the partitioning lip18b, so by forming the tip end of the seal lip18aso that it is compressed easily, it becomes possible to perform capping with even a smaller cap load.

Furthermore, another variation of a cap is shown inFIGS. 11A and 11B. This cap30is a cap that can be used for the purging process and for storing the nozzles when not printing, and it is made using elastic material that is formed into a square shape as shown in the top view ofFIG. 11A. Also, a seal lip31is formed on the top surface of the cap30so that it is protrudently ring-shaped along the outer perimeter of the cap30, and on the inside of the seal lip31there is a protruding ring-shaped partitioning lip32(seeFIG. 11B). The partitioning lip32is formed in a long rectangular shape that is long in the direction of arrangement of the nozzle groups that are located on the nozzle surface of the printing head.

The seal lip31is of a size such that it is capable of covering all of a plurality of nozzle groups on the nozzle surface of the printing head, and the partitioning lip32is of a size such that it is capable of covering a nozzle group that sprays a specified ink. Also, the seal lip31and partitioning lip32are formed so that the tip end of the partitioning lip32protrudes out more than the tip end of the seal lip31. The tip end sections of the lips31,32are formed so that the inside and outside surfaces are inclined and so that they have a triangular cross section. Also, the thickness at the bottom section of the partitioning lip32becomes thin, forming a neck section33.

Moreover, an ink-discharge port34is formed in the cap30so that it penetrates from top to bottom of the cap30and is located within the partitioning lip32at a position near one side in the lengthwise direction. Similar ink-discharge ports35,36are on both sides of the partitioning lip32between the partitioning lip32and seal lip31, and are located so that they are inline horizontally with the ink-discharge port34.

The capping method that uses this cap30to cap the printing head will be explained usingFIGS. 12A and 12B. The printing head40and cap30are brought close to each other from a state in which the cap30faces the nozzle surface41of the printing head40, and first the tip end of the partitioning lip32comes into contact6with the nozzle surface41(seeFIG. 12A).

By doing this, only a nozzle group (not shown in the figure) that is located on the nozzle surface41and that sprays a specified ink is covered by the partitioning lip32. The cap30is then brought even closer to the printing head40so that the tip end of the seal lip31comes in contact with the nozzle surface41, and the seal lip31covers all of the nozzle groups on the nozzle surface41(seeFIG. 12B).

When the printing head40is capped in this way, inside of the partitioning lips32, the tip end of the partitioning lip32comes in closer contact with the nozzle surface41than the tip end of the seal lip31, and the inside is covered from the outside by both the partitioning lip32and seal lip31, so when capped, the seal inside the partitioning lip32is very high, and the ink of the nozzle group that is covered by the partitioning lip32is kept in a moist state, so it becomes difficult for ink to become thick due to dryness.

For example, by assuming that the black ink inFIG. 3dries more easily and becomes thick more easily than the other ink, the two-row nozzle group14bthat sprays black ink is covered by the partitioning lip32, and all of the nozzle groups14b,14y,14mand14con the nozzle surface are covered by the seal lip31. By covering ink that becomes thick more easily and has lower resistance to drying than other ink that is sprayed from the nozzle groups by the partitioning lip32in this way, capping becomes possible in which the contact load between the seal lip31and nozzle surface41is suppressed, and together with being able to reduce the cap load when covering the printing head40with the cap30, it is possible to reduce the load on the capped printing head40.

Also, since the rigidity is lowered by forming the neck section33on the partitioning lip32, it is possible to reduce the contact load between the partitioning lip32and the nozzle surface41, and in doing so it is possible to reduce cap load and further reduce the load on the capped printing head40. Therefore, particularly; it is possible to effectively store the nozzles when not printing and the printing head is capped for a long period of time without applying a load on the printing head40or carriage (not shown in the figure) on which the printing head40is mounted.

By covering the nozzle surface41with the cap30and performing purging, the ink that is discharged inside the partitioning lip32, and the ink that is discharged between the partitioning lip32and seal lip31, can be discharged separately to the outside of the cap30through the ink-discharge ports34,35,36and collected. The ink-discharge ports34,35are formed at two locations between the partitioning lip32and seal lip31, however, it is possible to discharge the ink through an ink-discharge port that is located at only one location, and to collect the ink.

With the cap30of the variation described above, only one ring-shaped partitioning lip32is located on the inside of the seal lip31, however, the invention is not limited to this, and it is possible to have two or more. Also, in the variation described above, the cross-sectional shape of the seal lip31and partitioning lip32is changed by having a difference in height, however, beside this it is also possible to change the width, or to make one a forked shape.