JP2003080739A - Image forming apparatus and waste liquid absorption unit used therein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem wherein a waste liquid absorption body having a structure in which a plurality of absorption bodies having different densities are laminated results in a high cost and when the waste liquid absorption body is provided to a whole of the bottom section of an image forming apparatus, and the thickness of the waste liquid absorption body becomes unnecessarily great, thereby making the reduction of the size difficult. SOLUTION: This image forming apparatus is equipped with an ejection recovery means for improving an ejection condition of a liquid from a head unit 11 for ejecting a liquid to a printing medium P. The ejection recovery means comprises a waste liquid absorption unit 26 having a waste liquid absorption body that absorbs to hold a waste liquid introduced from the head unit 11 and a containing vessel 29 for containing the waste liquid absorption body. The waste liquid absorption body has a first and second absorption bodies 27, 28 which are abutted to the bottom plate section 30 of the containing vessel 29. The different kinds of waste liquids introduced from the head unit 11 are efficiently absorbed by the first and second absorption bodies 27, 28.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming an image on a print medium by using a plurality of liquid ejecting heads for ejecting a liquid, and a waste liquid absorbing unit used in the image forming apparatus.

[0002] In the present specification, "print" is not limited to the case of forming significant information such as characters and figures, but is also manifested so that it can be visually perceived by humans regardless of significance. Regardless of whether it is a material or not, it also includes forming a wide range of images, patterns, patterns, etc. on a print medium, or processing such as etching.

The "print medium" is not only a paper piece used in a general printing apparatus, but also a cloth, a plastic film, a metal plate, glass, ceramics, wood, leather, or the like which can receive a liquid. A three-dimensional solid other than a sheet-like object, such as a sphere or a cylinder, is also applicable.

Further, the "liquid" means the above "print".
It should be broadly interpreted like the definition of "," and is applied to a print medium to form an image, a pattern, a pattern, etc., or an etching process of the print medium, or an ink treatment (for example, applied to the print medium) Including those used for coagulation or insolubilization of coloring materials in ink).

[0005]

2. Description of the Related Art An image forming apparatus adopting an ink jet method is used in a printer, a copying machine, a facsimile or the like because of its low noise, low running cost, easy miniaturization and easy colorization. .

However, the image formation by the ink jet system has the following inherent problems. That is, first, since an ink droplet is ejected from the inkjet head onto a print medium such as paper or an OHP film to form an image, a sub-action is accompanied by the operation of ejecting the droplet from the ink jet head onto the print medium. If fine droplets (mist) are subsequently generated or the droplets bounce off and adhere to and accumulate near the ejection port of the inkjet head, the normal ejection of the droplets will be hindered and the direction will be unexpected. There is a possibility that the liquid droplets may be deflected or that in the worst case, the liquid droplets cannot be ejected. Such a problem tends to become more remarkable as foreign matter such as paper dust further adheres to the liquid droplets that have adhered to the vicinity of the ejection port of the inkjet head. Secondly, if liquid droplets are not ejected from the inkjet head for a long period of time, part of the liquid held in the inkjet head evaporates and its viscosity rises, or in the worst case, it solidifies. As a result, when the ejection operation is performed, the droplets may be deflected in an unexpected direction, or the droplets may not be ejected.

In order to deal with such a problem peculiar to the ink jet head system, the ejection port surface of the ink jet head is periodically wiped to remove the droplets and foreign substances adhering thereto, or the ink jet head ejects the ink. In the so-called non-printing state where no operation is performed,
The ejection port surface of the inkjet head is covered with a capping member in an airtight state to prevent evaporation of the liquid interposed in the inkjet head. In addition, even if such a capping operation is performed, if the viscosity of the liquid in the inkjet head rises or solidifies, the inside of the inkjet head is forcibly forced by the suction pump via the capping member. The liquid is sucked and the viscosity is increased or the liquid is in a semi-solidified state is discharged from the inkjet head, so that the liquid discharged from the liquid discharge head can be maintained in a good state. All of these processes are known as recovery processes.

The liquid sucked from the ink jet head by the above-mentioned suction pump, that is, the waste liquid is permeated and held in the porous waste liquid absorber such as the fiber bundle or the continuous foamed resin contained in the waste liquid container. This waste liquid absorber has the number of defective prints, the number of recovery processes, the amount of waste liquid discharged from the inkjet head by one recovery operation,
The volume is determined according to the amount of minute liquid droplets (mist) generated by the droplet discharging operation. On the other hand, when considering the image forming apparatus as a whole, it can be expected that a smaller volume of the waste liquid absorber is not restricted by the installation location and the cost is lower. However, if the volume of the waste liquid absorber is made too small with respect to the required volume, the waste liquid absorber needs to be periodically replaced, which causes maintenance complexity.

Therefore, there is a technique in which the volume of the waste liquid absorber is minimized by positively evaporating the waste liquid that is permeated and retained in the waste liquid absorber.
It is proposed in Japanese Patent No. 065.

On the other hand, when a color image is formed on a print medium such as paper by the ink jet method, ink bleeding occurs between the black ink and other color inks.
It has been pointed out that it causes deterioration in image quality. In order to solve such a problem, a technique has been proposed in which black ink and other color inks are chemically reacted with each other on a print medium to suppress the flow of ink and thereby suppress color bleeding. There is. Further, in text documents and the like, black ink containing a pigment component has been used in order to improve the quality of characters printed with black ink.

In an image forming apparatus using an ink having such characteristics, since the waste ink itself has a property of easily thickening or solidifying, its permeability to the waste liquid absorber is poor, and the waste liquid absorber as a whole is It is difficult to diffuse the waste ink. For this reason, a waste liquid absorption unit has been proposed in which a low-density absorber is placed on the bottom surface of the waste liquid container, and a high-density absorber is further stacked on it, and by guiding the waste liquid to the bottom surface of this waste liquid absorption unit. The high-viscosity or easy-to-solidify component in the ink is mainly permeated and retained in the low-density absorber, and the other low-viscosity ink components are permeated and retained in the high-density absorber.

[0012]

In an ink jet type image forming apparatus, since a waste liquid absorber having a volume capable of absorbing waste liquid until the end of its product life is incorporated and the image forming apparatus is made compact, It is common to arrange the waste liquid absorber in a two-dimensional plane over the entire bottom surface of the image forming apparatus to reduce the thickness of the waste liquid absorber. Therefore, as the size of a print medium that can be printed as a product specification is larger, the bottom area of the image forming apparatus tends to be larger. Therefore, the apparatus can be made more compact by reducing the thickness of the waste ink absorber. Becomes

However, the waste liquid absorber having a structure in which a plurality of absorbers having different densities are laminated has more parts and manufacturing costs than the absorber having a single-layer structure having a uniform density. This contributes to increasing the cost of the image forming apparatus arranged over the entire bottom surface. Further, when the waste liquid absorber having such a laminated structure is arranged on the entire bottom surface of the image forming apparatus, the volume of the low-density absorber tends to be too large with respect to the product life. Even if the low-density absorber continues to absorb and absorb the waste liquid that is easily viscous or solidifies, a part of the low-density absorber that does not absorb the high-viscosity or easily solidified waste liquid remains, resulting in a wasted space. I was sick. In other words, it is understood that arranging the waste liquid absorber having a laminated structure on the entire bottom surface of the image forming apparatus leads to making the thickness of the waste liquid absorber unnecessarily thick and hinders downsizing of the image forming apparatus. I can do it.

[0014]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ejection recovery means for improving the ejection state of liquid from a plurality of liquid ejection heads for ejecting liquid onto a print medium, respectively. An object of the present invention is to provide an image forming apparatus which has a compact and highly reliable waste liquid absorbing unit capable of efficiently permeating and holding a waste liquid, and a waste liquid absorbing unit used in this image forming apparatus.

[0015]

The first aspect of the present invention is as follows.
An image forming apparatus comprising ejection recovery means for improving the ejection state of liquid from a plurality of liquid ejection heads ejecting liquid onto a print medium, wherein the ejection recovery means is provided from each of the liquid ejection heads. The waste liquid absorber has a waste liquid absorber that permeates and holds the guided waste liquid, and a storage container that stores the waste liquid absorber. The waste liquid absorber includes first and second absorbers that are in contact with the bottom surface of the storage container. It is characterized by having.

In the present invention, in order to improve the discharge condition of the liquid from the liquid discharge head, the waste liquid introduced from the liquid discharge head by the discharge recovery means is permeated and held in the waste liquid absorber contained in the container. . In this case, the first and second absorbers that constitute the waste liquid absorber are accommodated in a planar spread so as to be in contact with the bottom surface of the accommodating container, respectively, and the waste liquid from one of the liquid discharge heads is accommodated in the first absorber. The absorbent is permeated and held by the absorber, the waste liquid from the other liquid ejection head is permeated and held by the second absorber, and different types of waste liquid are efficiently absorbed by the first and second absorbers.

In the second aspect of the present invention, the waste liquids respectively led from the plurality of liquid ejection heads are permeated in order to improve the ejection state of the liquids from the plurality of liquid ejection heads respectively ejecting the liquid onto the print medium. A waste liquid absorber to be held, and a container for containing the waste liquid absorber, wherein the waste liquid absorber has first and second absorbers respectively abutting on the bottom surface of the container. Located in the waste liquid absorption unit.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION In the image forming apparatus according to the first embodiment of the present invention, the first absorber has a higher density than the second absorber and covers the second absorber. You can In this case, the waste liquid absorber may further have an opening that extends from the upper end of the waste liquid absorber to the bottom surface of the storage container through the first and second absorbers.

A plurality of liquid ejection heads may eject different types of liquid, and these different types of liquid may have a tendency to thicken or solidify when mixed together. In this case, different types of liquid may be the treatment liquid for adjusting the printability of the ink on the ink and the print medium. Alternatively, different types of liquid may be black ink and other color inks,
In this case, the black ink or any other color ink may contain a pigment.

The first absorber may be divided into a first block that abuts on the bottom surface of the container and a second block that is placed on the second absorber. In this case, it is possible to have an opening that extends from the upper end of the second block of the first absorbent body to the bottom surface of the container through the second block and the second absorbent body. Further, it is effective to press-fit these into the container so that the first block and the second block come into contact with each other in a compressed state.

In the waste liquid absorption unit according to the second aspect of the present invention, the first absorbent body may have a higher density than the second absorbent body and cover the second absorbent body. In this case, the waste liquid absorber may further have an opening that extends from the upper end of the waste liquid absorber to the bottom surface of the storage container through the first and second absorbers.

The first absorber may be divided into a first block that abuts on the bottom surface of the container and a second block that is overlaid on the second absorber. In this case, it is possible to have an opening that extends from the upper end of the second block of the first absorbent body to the bottom surface of the container through the second block and the second absorbent body. Further, it is effective to press-fit these into the container so that the first block and the second block come into contact with each other in a compressed state.

[0023]

EXAMPLE An example in which the image forming apparatus according to the present invention is applied to a serial scan type ink jet printer will be described in detail with reference to FIGS.
The present invention is not limited to these examples, and further combinations thereof, and any changes and modifications included in the concept of the present invention described in the claims are possible, and therefore belong to the spirit of the present invention. Of course, it can be applied to other technologies.

A schematic structure of the ink jet printer according to this embodiment is shown in FIG. That is, the head unit 11 as a plurality of liquid ejection heads of the present invention capable of ejecting inks of a plurality of colors (four colors of black, cyan, magenta, and yellow in this embodiment) is different from the head unit 11. The ink tank 12 is detachably mounted on the carriage 13 together with the plurality of ink tanks 12 that are exchangeably connected. Four sets of discharge ports (not shown) arranged at predetermined intervals are opened on the discharge port surface 14 of the head unit 11, and by selectively driving the discharge energy generation units (not shown) incorporated in these head units 11. The predetermined ink is ejected from the corresponding ejection port.

In contrast to the black ink used in this embodiment, which is a pigment-based one which is highly viscous or easily solidified,
The other color inks, that is, cyan ink, magenta ink, and yellow ink, use dye-based ones so that color bleeding does not occur much even when black ink and color ink are mixed. There is.

The carriage 13 is slidably attached along a guide rod 15 extending in the left-right direction in FIG. 1, and a pair of pulleys 16, 1 arranged at both left and right ends of the guide rod 15.
It is connected to a drive belt 18 wound around 7. A scanning drive motor 19 is connected to one pulley 16, and the driving belt 18 is swung by driving the scanning drive motor 19, and the carriage 13 is guided along the guide rod 15 in accordance with the swiveling motion of the driving belt 18. 1, the scanning movement is performed in the left-right direction in FIG.

Below the guide bar 15, it extends along the guide bar 15 so as to face the ejection port surface 14 of the head unit 11, and the print medium P during the printing operation.
A platen 20 for maintaining the flatness of the plate is fixed.
The print medium P is conveyed by a print medium conveying unit (not shown) in the front-rear direction (direction perpendicular to the paper surface of FIG. 1) orthogonal to the scanning direction of the carriage 13, and when the print medium P passes through the platen 20, it is ejected from the head unit 11. A predetermined image is formed by the ejected ink. In this case, the scanning movement of the carriage 13 and the transport operation of the print medium P are alternately repeated, and a band-shaped image corresponding to the array length of the ejection ports is sequentially formed on the print medium P.

On one side of the scanning movement end of the carriage 13, an ejection recovery unit 21 which constitutes a part of the ejection recovery means of the present invention is arranged adjacent to the side of the platen 20, and the ejection recovery unit 21 is provided. Is the head unit 11
It is possible to move up and down in the direction opposite to the discharge port surface 14 (vertical direction in FIG. 1). That is, the scanning position of the head unit 11 facing the ejection recovery unit 21 becomes the home position of the head unit 11 when not printing. The ejection recovery unit 21 is provided with a pair of capping members 22 and 23 that cover the ejection port surface 14 of the head unit 11 at the rising end position. In this embodiment, one capping member 22 is a pigment-based one. The other capping member 23 that covers the ejection port group that ejects black ink
Collectively covers the three ejection port groups that eject the dye-based color ink, so that part of the ink evaporates and dries from the ejection ports of the head unit 11 during non-printing, and It is designed to prevent the intervening ink from thickening and solidifying.

These pair of capping members 22, 23
Waste ink guide pipes 24 and 25 are connected to the waste ink guide pipes 24 and 25, respectively, and suction pumps (not shown) housed in the discharge recovery unit 21 are interposed in the middle of the waste ink guide pipes 24 and 25, respectively. These suction pumps make the inside of the head unit 11 into a negative pressure state at the time of the suction recovery process of the head unit 11, so that thickened ink or the like intervenes in an ink passage (not shown) communicating with the ejection port of the head unit 11 or the like. From the capping members 22 and 23 to the waste liquid absorbing unit 26 via the waste ink guide tubes 24 and 25.

The waste liquid absorbing unit 26 in this embodiment is shown in a disassembled state in FIG. 2, and its plan view is shown in FIG. That is, the waste liquid absorption unit 26 arranged immediately below the ejection recovery unit 21 so as to face the lower ends of the waste ink guide tubes 24 and 25 is spread over almost the entire lower surface of the ink jet printer, and mainly the color inks. Low-density first absorbent body 27 that permeates and holds the waste liquid of No. 2, high-density second absorbent body 28 that permeates and holds the waste liquid of black ink, and housing that accommodates these first and second absorbent bodies 27, 28. The container 29 and the main part are configured. The rectangular dish-shaped container 29 has a flat rectangular bottom plate portion 30 that substantially corresponds to the planar projection shape of the inkjet printer, and a side wall portion 31 that surrounds the bottom plate portion 30. The second absorber 28 is in the form of a rectangular thin plate that occupies an area that is approximately half the strength of the bottom plate portion 30. The first absorbent body 27 having a dimension that spreads over the entire area of the bottom plate portion 30 includes a thick wall portion 27S occupying a region of a little less than half of the bottom plate portion 30 and a thin wall portion 27 that is overlapped with the second absorbent body 28.
R, and the thick portion 27S is lightly accommodated in the accommodation container 29 in a compressed state so that the thick portion 27S contacts the surface of the bottom plate portion 30 together with the second absorber 28.

The thin portion 27R of the first absorber 27 and the second
In the absorber 28, an opening 32 extending from just above the lower end of one waste ink guide tube 24 from which the waste liquid of black ink is discharged to the surface of the bottom plate portion 30 of the container 29, and from this opening 32 to the right side in FIG. That is, the other end side of the carriage 13 in the scanning movement direction and the guide groove 33 extending in the lower side in FIG. 3, that is, in the transport direction of the print medium P are formed. Further, the lower end of the other waste ink guide tube 25 from which the waste liquid of the color ink is discharged is in a state of facing the upper end surface of the thin portion 27R of the first absorber 27 located on the side of the opening 32. There is.

Therefore, the waste liquid of the black ink, which is easily thickened or solidified by the presence of the pigment, is dripped directly from the opening 32 to the bottom plate portion 30 of the container 29, and from there, the container 29.
It diffuses in a plane along the bottom plate portion 30 and is permeated and held by the low-density second absorber 28. On the other hand, the waste liquid of the color ink having good permeability is dropped onto the surface of the thin portion 27R of the high-density first absorbent body 27, and is permeated and held throughout the entire first absorbent body 27. During the process in which the waste liquid of the black ink containing the pigment component is permeated and held in the second absorber 28, its thickening or solidification proceeds, so that the area in which this diffuses in a plane is limited, and the second diffuser 28 is more than necessary. It should be understood that there is no point in expanding the area occupied by the two absorbers 28.
Therefore, it is not necessary to stop the occupied area of the second absorbent body 28 at a part of the bottom plate portion 30 of the storage container 29 and set the thickness thereof to be transiently thick. By interposing the above, it is possible to more efficiently separate and absorb the black ink waste liquid and the color ink waste liquid, and to reduce the laminated structure area by the first and second absorbers 27 and 28. It is also possible to plan cost reduction. In the present embodiment, the wall thickness of the second absorbent body 28 is set to half or less of the wall thickness of the thin wall portion 27R of the first absorbent body 27. However, by forming the guide groove 33 communicating with the opening 32, The waste liquid of the black ink can be surely permeated and retained in the end region of the second absorber 28 which is separated from the opening 32.

It is not necessary to form the guide groove 33 so as to open at the upper end surface of the thin portion 27R of the first absorbent body 27, and only the second absorbent body 28 or below the thin wall portion 27R of the first absorbent body 27 is formed. Similar effects can be obtained by forming a tunnel shape on the side.

In the above-described embodiments, the dye-based color ink and the pigment-based black ink that is easily thickened or solidified are used. However, a plurality of kinds of inks are mixed to easily thicken or solidify. The technology of the present invention can be applied to those having Further, in the above-mentioned embodiment, the high-density first absorbent body 27 is formed in one sheet shape, but it may be divided into two or more in accordance with the shape of the low-density second absorbent body 28. Is. A plan view of another embodiment of the waste liquid absorbing unit 26 according to the present invention is shown in FIG.
The cross-sectional shape taken along the line V-V is shown in FIG. 5, but the elements having the same functions as those in the previous embodiment will be denoted by the same reference numerals, and redundant description will be omitted. That is, the first absorbent body 27 in the present embodiment is divided into the thick portion 27S that is the first block and the thin portion 27R that is the second block. The thin portion 27R and the second absorbent body 28 have the same contour shape, and the concave and convex fitting portions 34 are formed in these divided portions to ensure a reliable contact state between the thick portion 27S and the thin portion 27R. In order to obtain, the thick portion 27S and the thin portion 27R are pressed into the storage container 29 in a compressed state,
Furthermore, so that the fitting portions 34 themselves are in a mutually compressed state,
These width dimensions W are also set appropriately.

In this embodiment, the thin wall portion 2 of the first absorber 27 is used.
Since the laminated portion including the 7R and the second absorber 28 and the thick portion 27S of the first absorber 27 can be separately formed, the manufacturing cost can be suppressed more than that in the previous embodiment.

The present invention comprises means for generating thermal energy as the energy used for ejecting the liquid (for example, an electrothermal converter or laser light), and this thermal energy causes a change in the state of the liquid. This brings about an excellent effect in the inkjet type image forming apparatus. This is because according to such a method, high density and high definition printing can be achieved.

The present invention can be effectively applied to a full line type liquid ejection head having a length corresponding to the maximum width of a print medium that can be printed by the image forming apparatus.
Such a liquid ejection head may have a configuration that fills the length by a combination of a plurality of liquid ejection heads or a configuration as one liquid ejection head integrally formed.

Even in the case of the serial scan type as in the above-described embodiment, the liquid discharge head integrally fixed to the carriage which moves by scanning and the electric power to the carriage by being exchangeably attached to the carriage. A replaceable chip-in type head cartridge that can be electrically connected and supplied with liquid from the apparatus main body, or a head cartridge in which a liquid storage head itself is provided with a tank that stores liquid is provided integrally or replaceably. In this case, the present invention is effective.

As the constitution of the image forming apparatus of the present invention, it is preferable to add a preliminary auxiliary means for making the ejection state of the liquid from the liquid ejection head proper because the effect of the present invention can be further stabilized. It is a thing. Specific examples thereof include cleaning means for the liquid ejection head, pressurizing means, preheating means for heating using an electrothermal converter, a heating element other than this, or a combination thereof, and a printing operation separately. Preliminary ejection means for ejecting may be mentioned.

Regarding the type and number of liquid ejection heads to be mounted, a plurality of types may be provided corresponding to a plurality of types of ink having different hues and densities (brightness). That is, as the print mode of the image forming apparatus, the liquid ejection head may be integrally configured or a plurality of combinations may be used, but at least one of the full-color print modes of different colors or mixed colors may be used. The present invention is extremely effective for an image forming apparatus provided with. In this case, it is also effective to eject the treatment liquid (printability improving liquid) for adjusting the printability of the ink onto the print medium from a dedicated or common liquid ejection head in accordance with the type of print medium and the print mode.

The form of the image forming apparatus according to the present invention is used as an image output terminal of information processing equipment such as a computer, a copying machine combined with a reader, a facsimile machine or a textile printing machine having a transmission / reception function. Alternatively, the print medium may be in the form of an etching device, and the print medium may be a sheet or a long paper or cloth, or a plate-like wood or leather,
In addition to stone materials, resins, glass, metals, etc., three-dimensional three-dimensional structures can be cited.

[0042]

According to the image forming apparatus of the present invention, the discharge recovery means has the waste liquid absorber that permeates and holds the waste liquid introduced from the liquid discharge head, and the storage container that stores the waste liquid absorber. Since the absorber has the first and second absorbers that respectively come into contact with the bottom surface of the container, the first absorber
And the second absorber can be accommodated in the accommodating container with a planar spread so as to contact the bottom surface of the accommodating container respectively, and the thickness of the waste liquid absorber can be minimized to make the entire image forming apparatus compact. Can be converted. In addition, the waste liquid from one liquid ejection head is permeated and held in the first absorbent body, and the waste liquid from the other liquid ejection head is permeated and held in the second absorbent body, so that different kinds of waste liquids can be stored in the first and second absorbent bodies. The second absorber can be efficiently absorbed. In particular, when a plurality of liquid ejection heads respectively eject different types of liquids and have a tendency to thicken or solidify when these different types of liquids are mixed, for example, different types of liquids may be used for ink and print media. It is effective when it is a treatment liquid for adjusting the printability of the ink, or when it is a black ink and other color inks, especially when the black ink or the other color ink contains a pigment.

According to the waste liquid absorbing unit of the present invention, the waste liquids respectively led from the plurality of liquid discharge heads are permeated in order to improve the discharge state of the liquids from the plurality of liquid discharge heads respectively discharging the liquid onto the print medium. The waste liquid absorber to be held and the container for accommodating the waste liquid absorber are provided. Since the waste liquid absorber has the first and second absorbers that respectively contact the bottom surface of the container, the first and second absorbers are provided. The absorbers can be accommodated in the accommodating container with a planar spread so that they come into contact with the bottom surface of the accommodating container respectively, and the thickness of the waste liquid absorber can be minimized to be compact.

In the image forming apparatus or the waste liquid absorbing unit of the present invention, when the first absorber has a higher density than the second absorber and covers the second absorber, an expensive first absorber is used. The use ratio of the absorber of No. 1 can be minimized.

When the waste liquid absorber further has an opening from the upper end thereof to the bottom surface of the container by penetrating the first and second absorbers, a highly viscous liquid is introduced from this opening to the bottom surface of the container. It is possible to guide and efficiently permeate and absorb the first absorber.

When the first absorbent body is divided into a first block that abuts the bottom surface of the container and a second block that overlaps the second absorbent body, the first and second blocks are It can be of simple shape.

In the case where there is further provided an opening from the upper end of the second block of the first absorbent body to the bottom surface of the container through the second block and the second absorbent body, a highly viscous liquid is opened in this opening. The first absorber can be efficiently permeated and absorbed by being guided from the portion to the bottom surface of the container.

The first block and the second block are
When these are pressed into the container so that they come into contact with each other in a compressed state, the waste liquid can be surely permeated between the first block and the second block, so that the waste liquid is removed from the first block and the second block. It can be spread over the entire second block.

[Brief description of drawings]

FIG. 1 is a sectional view taken along the line I-I in FIG. 3, showing a schematic structure of an embodiment in which an image forming apparatus according to the present invention is applied to a serial scan type inkjet printer.

FIG. 2 is an exploded perspective view showing an embodiment of the waste liquid absorbing unit according to the present invention shown in FIG.

FIG. 3 is a partially cutaway plan view of the waste liquid absorption unit shown in FIG.

FIG. 4 is a plan view showing another embodiment of the waste liquid absorbing unit according to the present invention.

5 is a sectional view taken along the line VV in FIG.

[Explanation of symbols]

11 head unit 12 ink tank 13 carriage 14 Discharge port surface 15 Guide rod 16,17 pulley 18 drive belt 19 Scan drive motor 20 Platen 21 Discharge recovery unit 22,23 Capping member 24,25 Waste ink guide tube 26 Waste liquid absorption unit 27 First absorber 27R Thin portion of the first absorber 27S Thick part of the first absorber 28 Second absorber 29 container 30 Bottom plate 31 Side wall 32 openings 33 guide groove 34 Fitting part P print media W Fitting width

Claims (16)

[Claims] 1. An image forming apparatus comprising an ejection recovery unit for improving a liquid ejection state from a plurality of liquid ejection heads for ejecting a liquid onto a print medium, wherein the ejection recovery unit comprises: A waste liquid absorber that permeates and holds the waste liquid respectively guided from the liquid ejection head, and a storage container that stores the waste liquid absorber are provided. The waste liquid absorber has a first and a first contact with a bottom surface of the storage container. An image forming apparatus having two absorbers. 2. The image forming according to claim 1, wherein the first absorber has a higher density than that of the second absorber and covers the second absorber. apparatus. 3. The waste liquid absorber further has an opening that extends from the upper end of the waste liquid absorber to the bottom surface of the container through the first and second absorbers. Image forming apparatus. 4. The plurality of liquid ejection heads respectively eject different types of liquid, and the different types of liquid have a tendency to thicken or solidify when mixed. 4. The image forming apparatus according to claim 3. 5. The image forming apparatus according to claim 4, wherein the different types of liquids are treatment liquids for adjusting the printability of the inks with respect to the ink and the print medium. 6. The image forming apparatus according to claim 4, wherein the different types of liquid are black ink and other color inks. 7. The image forming apparatus according to claim 6, wherein the black ink or any other color ink contains a pigment. 8. The first absorbent body is divided into a first block that abuts a bottom surface of the container and a second block that is stacked on the second absorbent body. The image forming apparatus according to any one of claims 1 to 7. 9. The container further comprises an opening from the upper end of the second block of the first absorbent body to the bottom surface of the container through the second block and the second absorbent body. The image forming apparatus according to claim 8, which is characterized in that. 10. The container according to claim 8, wherein the first block and the second block are press-fitted into the container so as to abut each other in a compressed state. Image forming apparatus. 11. A waste liquid absorber that permeates and holds waste liquids respectively introduced from a plurality of liquid ejection heads for improving the ejection condition of the liquids from a plurality of liquid ejection heads that eject liquids onto a print medium, respectively. A storage container for storing the waste liquid absorber, wherein the waste liquid absorber is in contact with a bottom surface of the storage container.
And a waste liquid absorption unit having a second absorber. 12. The waste liquid absorbent according to claim 11, wherein the first absorber has a higher density than the second absorber and covers the second absorber. unit. 13. The waste liquid absorber further has an opening that penetrates the first and second absorbers from the upper end thereof to reach the bottom surface of the storage container.
The waste liquid absorption unit according to 2. 14. The first absorbent body is divided into a first block that abuts a bottom surface of the storage container and a second block that is stacked on the second absorbent body. The waste liquid absorption unit according to any one of claims 11 to 13. 15. An opening is further provided from the upper end of the second block of the first absorbent body to the bottom surface of the container through the second block and the second absorbent body. The waste liquid absorption unit according to claim 14, which is characterized in that. 16. The container according to claim 14 or 15, wherein the first block and the second block are press-fitted into the container so as to come into contact with each other in a compressed state. Waste liquid absorption unit.