JP2000238292A - Waste ink recovery unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a decision surely whether a waste ink recovery unit is filled with recovered ink or not by providing an ink absorber with a part for finally absorbing waste ink, a second part for absorbing waste ink earlier the final part, and a transparent window for observing the final part and the second part. SOLUTION: When a waste ink recovery unit 40 is fixed to the body of a plotter, waste ink is absorbed through a tube 86 to a body side absorber 80 thence to the first part 62 of an ink absorber 60. When the first part 62 is substantially filled with ink, the second part 64 begins to absorb ink. When the second part 64 is substantially filled with ink, the final part 66 begins to absorb ink. Each part 62, 64, 66 is discolored upon absorbing waste ink. Consequently, the timing for replacing the waste ink recovery unit 40 (or the ink absorber 60) can be determined surely and accurately by observing the ink absorber 60 through a transparent window 54.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste ink collecting apparatus for collecting waste ink discharged or sucked from nozzles of a print head.

[0002]

2. Description of the Related Art As one of output devices of computers and workstations, there is known an ink jet type image forming apparatus which forms an image on a recording medium such as recording paper by discharging ink. The inkjet type image forming apparatus includes, for example, a print head in which nozzles for discharging ink are formed, a carriage mounted with the print head and reciprocating in a predetermined direction, and a direction orthogonal to the predetermined direction (recording medium conveyance). And a recording medium transport device that transports the recording paper in the direction (i.e., direction).

When an image is formed on a recording sheet, the recording sheet being conveyed by the recording medium conveying device is temporarily stopped, and the carriage is reciprocated in the above-mentioned predetermined direction to generate an image signal carrying image information. Discharging ink from the nozzle based on the
An image for one band is formed on a portion of the recording paper which is located in an image forming area facing an outlet (ink ejection port) of a nozzle. Thereafter, the paper is conveyed by the width of one band and stopped, and ink is ejected from the nozzles based on the image signal while the carriage is reciprocated again in the above-described predetermined direction. Then, an image is formed in a newly located portion. By repeating such an operation, an image is formed on the recording paper.

In an image forming apparatus using ink, such as the above-mentioned ink jet type image forming apparatus, when an image is continuously formed (printed), the ink discharge state of nozzles changes, and the image quality may be degraded. There is. The reason why the state of ink ejection from the nozzles changes is that bubbles are generated in the nozzles or foreign substances are mixed therein. Therefore, in order to remove bubbles, foreign matter, and the like in the nozzle, a recovery device that forcibly sucks (or discharges) ink from the nozzle and recovers an ink discharge state to an initial state is used.

This recovery device is used by judging the ink discharge state during printing, or is used at predetermined time intervals of printing. In the recovery device, the outlet of the nozzle formed in the print head is covered with a cap made of rubber or the like (capping), and a negative pressure is externally generated to suck ink from the nozzle to clean the inside of the nozzle. As a result, the ink is sucked from the nozzle, and the ink ejection state is restored to the initial normal ejection state.

Ink (waste ink) sucked by the recovery device
Is collected in the waste ink collecting device. Some of the waste ink recovery devices include an ink absorber that absorbs waste ink therein. For example, for a small printer,
The amount of waste ink discharged from one print head is not so large. Therefore, if a waste ink collecting device of an appropriate size is incorporated in the printer main body, it is possible to prevent ink from overflowing from the waste ink collecting device.

However, in recent years, miniaturization of an image forming apparatus such as a printer and extension of life of the image forming apparatus have been attempted. In this case, since the waste ink collecting device is also downsized, the ink absorber cannot absorb the waste ink during image formation, and the waste ink collecting device becomes full of waste ink.
Also, in the case of a large printer or plotter, the amount of waste ink is very large, and several liters of waste ink may be generated. In such a case as well, the ink absorber cannot absorb the waste ink during image formation, and the waste ink recovery device becomes full of waste ink. Therefore, in such a case, the ink absorber is replaced before the waste ink collecting device is full with the waste ink.

[0008]

However, it is difficult to determine whether or not the waste ink collecting device is full of waste ink. For example, it is determined whether or not the waste ink collecting device is full by using a sensor or the like. However, there is a risk that the sensor may make an erroneous detection, and it is difficult to reliably determine whether the waste ink collecting device is full of waste ink. In addition, before the waste ink collecting device becomes full with the waste ink, it is necessary to replace the ink absorber that has almost completely absorbed the waste ink with a new one.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a waste ink collecting apparatus capable of reliably determining whether or not the collected waste ink is full.

[0010]

According to a first aspect of the present invention, there is provided a waste ink collecting apparatus for ejecting ink from said nozzles while reciprocating a print head having nozzles for ejecting ink in a predetermined direction. (1) In the ink-jet image forming apparatus for forming an image on a recording medium, a waste ink recovery device including therein an ink absorber for absorbing waste ink discharged or sucked from the nozzle is provided. The body has a last part that absorbs waste ink last and a second part that absorbs waste ink before the last part, and (2) observes the last part and the second part. And a transparent window.

Here, (3) in the ink absorber, the second portion may have a stronger suction force for sucking waste ink than the final portion.

(4) The second portion may change color before the final portion changes color.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a waste ink collecting apparatus according to the present invention will be described with reference to the drawings.

Referring to FIG. 1, a plotter (an example of an ink jet type image forming apparatus according to the present invention) incorporating a waste ink collecting apparatus of the present invention will be described.

FIG. 1 is a perspective view schematically showing a plotter in which a waste ink collecting device of the present invention is incorporated.

The plotter 10 has a platen 14 on which the recording paper 12 conveyed in the direction of arrow A is placed. Above the platen 14, two guide shafts 16 are extended in parallel with the platen 14. A carriage 18 that freely reciprocates in directions indicated by arrows B and C (a direction orthogonal to the direction of arrow A) by a motor (not illustrated) and a belt (not illustrated) is provided on the guide shaft 16 by a slide bearing (not illustrated). Attached via).

The carriage 18 is provided with a print head 20 having ink discharge ports (nozzle outlets, not shown) for discharging ink. An image forming area 22 in which an image is formed is located in front of the ink ejection port. Ink is ejected from the ink ejection port to a portion of the recording paper 12 located in the image forming area 22 to form an image.

At a position on one side of the movable range of the carriage 18 away from the image forming area 22, ink is forcibly sucked from the nozzles to clean the ink supply paths and nozzles formed in the print head 20. A recovery device 30 is provided for setting the ink discharge state of the print head 20 to the initial discharge state. A waste ink collecting device is arranged below the recovery device 30.

In forming an image on the recording paper 12,
The recording paper 12 is placed on the platen 14, and the recording paper 12 is transported by a transport roller 24 having a part of the outer peripheral surface exposed from an opening (not shown) formed in the platen 14 and both ends of the recording paper 12. The sheet is nipped by a pinch roller 26 pressed from above, and is transported by rotating a transport roller 24 by a motor (not shown). The carriage 18 is reciprocated in the directions of arrows B and C above the recording paper 12, and ink is ejected from the nozzles based on an image signal carrying image information transmitted from the control device 28 to the print head 20. Out of 12,
An image is formed on a portion located in the image forming area 22. During the image forming operation, when it becomes necessary to suck ink from the nozzles to clean the nozzles, the carriage 18 is moved above the recovery device 30.

A first embodiment of the waste ink collecting apparatus will be described with reference to FIGS. 2 and 3.

FIG. 2 is a cutaway perspective view showing a part of the waste ink collecting device, and FIG. 3 is a sectional view taken along line DD of FIG.

The waste ink collecting device 40 includes a plotter 10
(Refer to FIG. 1) It is detachably incorporated in the main body, and is replaced before being filled with waste ink. This waste ink collecting device 40
Has a rectangular parallelepiped waste ink tank 50 and an ink absorber 60 housed inside the waste ink tank 50.
The waste ink tank 50 includes an upper lid 5 made of a mesh member.
2 is provided. Further, a side wall in front of the waste ink tank 50 (on the left side of the paper surface of FIG. 3) is formed of a transparent window 54 through which the inside of the waste ink tank 50 can be viewed. A portion of the transparent window 54 where a second portion described later can be observed corresponds to the second transparent window according to the present invention.

The ink absorber 60 includes a first portion 62 that absorbs waste ink first, a second portion 64 that absorbs waste ink after the first portion 62 cannot absorb waste ink,
And it is divided into three parts, a final part 66 that absorbs waste ink last. A partition plate 68 for partitioning from the first portion 62 is formed behind the second portion 64 and the final portion 66 (on the right side of the paper surface of FIG. 3). Also, among the three parts 62, 64, 66, the first part 62 is
The suction force for sucking up the waste ink is the strongest, and the second portion 64
Is the next strongest, and the final portion 66 is the weakest. Therefore, waste ink is absorbed by the second portion 64 from below (from the direction of arrow E). The three parts 62, 64,
The wicking force of 66 is in the range of 5 cm to 14 cm.

The material of the ink absorber 60 includes a nonwoven fabric based on rayon, a polypropylene fiber, and a polyolefin hydrophilic porous plastic. In order to make the ink absorber 60 absorb the waste ink step by step,
The ink absorbing body 60 is manufactured by combining the above materials, and the suction force for sucking waste ink can be changed. Further, even if the same material is used, the above-described suction force can be changed by changing the thickness. For example, in the case of an ink absorber made of a rayon base material, the suction force differs by about 30% between a thickness of 3 mm and a thickness of 5 mm.

The three parts 62, 64, 66 described above are:
Color changes by absorbing waste ink. Therefore, by observing the ink absorber 60 from the transparent window 54, the final portion 66
Is visually discolored, it can be determined that the waste ink recovery device 40 is almost full of waste ink. If the final portion 66 is not discolored but most of the second portion 64 is discolored, the final portion 66
Soon, the waste ink will be absorbed and the waste ink collecting device 40
Can be expected to be full with waste ink. If neither the second portion 64 nor the final portion 66 has changed color, it can be determined that the waste ink can still be absorbed.

An opening 70 is formed behind the waste ink tank 50 (on the right side of the paper surface of FIG. 3, opposite to the transparent window 54). In the opening 70, the ink absorber 6
The first part 62 of the zero is exposed. The body-side absorber 80 comes into contact with the exposed portion when the waste ink recovery device 40 is mounted on the body. The main body-side absorber 80 includes a spring-like member 8 fixed to a fixing plate 82 of the main body with screws 82a.
4 is held. Tube 8 is used for main body side absorbent body 80
6 is connected, and the waste ink is absorbed by the main body side absorber 80 through the tube 86.

When the waste ink collecting device 40 is mounted on the main body of the plotter 10, the first portion 6 of the ink absorber 60
The waste ink recovery device 40 is locked by the lock member 90 in order to sufficiently bring the body 2 and the main body side absorber 80 into close contact with each other.
The lock member 90 is provided with the arrow F,
It is a bar-shaped member having a hook portion 94 that rotates in the F ′ direction and a spring hook portion 96 that is located on the opposite side of the rotation shaft 92 from the hook portion 94. One end of a coil spring 98 is hooked on the spring hook 96, and the other end of the coil spring 98 is hooked on the main body of the plotter 10. For this reason, the handle 94 is urged by the coil spring 98 to rotate in the direction of arrow F.

A protrusion 94 a is formed on the upper surface of the handle 94, and the protrusion 94 a contacts the protrusion 50 a formed on the bottom wall of the waste ink tank 50. On the bottom wall of the waste ink tank 50 opposite to the convex portion 50a, a convex portion 50b is provided.
Are formed, and the projection 50b is locked to the main body claw 88.

When the waste ink collecting device 40 is mounted on the main body of the plotter 10, the waste ink is absorbed by the main body-side absorber 80 through the tube 86, and is further absorbed by the ink absorber 60.
Is absorbed by the first portion 62 of the When the first portion 62 is substantially full of waste ink, the second portion 64 begins to absorb waste ink. When the second portion 64 is substantially full of waste ink, the final portion 66 begins to absorb waste ink. As described above, each of the portions 62, 64, and 66 changes color when the waste ink is absorbed. Therefore, by observing the ink absorber 60 through the transparent window 54, the waste ink recovery device 40 (or the ink absorber 60) can be used. The replacement time can be reliably and accurately determined.

A second embodiment of the waste ink collecting apparatus will be described with reference to FIGS.

FIG. 4 is a perspective view showing a second embodiment of the waste ink collecting device, and FIG. 5 is a sectional view taken along line GG of FIG.

The waste ink collecting device 100 includes a plotter 10
(Refer to FIG. 1) It is detachably incorporated in the main body, and is replaced before being filled with waste ink. This waste ink recovery device 10
0 has a rectangular parallelepiped waste ink tank 110 and an ink absorber 120 housed inside the waste ink tank 110. The waste ink tank 110 has three transparent windows 112.
a, 112b and 112c are provided. The transparent window 112b corresponds to the second transparent window according to the present invention.

The ink absorber 120 includes a first portion 122 that first absorbs waste ink, a second portion 124 that absorbs waste ink after the first portion 122 cannot absorb waste ink, and a first portion 122 that absorbs waste ink. Last part 12 to be absorbed last
6 is divided into three parts. The first portion 122 and the second portion 124 are separated by a partition plate 130 except for a contact portion 128 where they are in contact with each other. Similarly, the second portion and the final portion 126 are separated by a partition plate 134 except for a contact portion 132 where they are in contact with each other. Also, three parts 122, 124, 1
Among the 26, the first portion 122 has the highest suction force for sucking waste ink, the second portion 124 has the next highest suction force, and the final portion 126 has the lowest suction force. Therefore, the waste ink absorbed by the first portion 122 is absorbed by the second portion through the contact portion 128. Further, the waste ink absorbed by the second portion 124 passes through the contact portion 132 and is absorbed by the final portion 126. The three parts 122, 124, 126
Has a suction force in the range of 5 cm to 14 cm.

Examples of the material of the ink absorber 120 include a nonwoven fabric based on rayon, a polypropylene fiber, and a polyolefin-based hydrophilic porous plastic. In order to make the ink absorber 120 absorb the waste ink step by step, the ink absorbing body 120 is manufactured by combining the above materials, and the suction force for sucking up the waste ink can be changed. Further, even if the same material is used, the above-described suction force can be changed by changing the thickness. For example, in the case of an ink absorber made of a rayon base material, the suction force differs by about 30% between a thickness of 3 mm and a thickness of 5 mm.

The above three parts 122, 124, 12
No. 6 changes color by absorbing waste ink. Therefore, when the final portion 126 of the ink absorber 120 is observed from the transparent window 112c and it is visually observed that most of the final portion 126 is discolored, the waste ink recovery device 100 is almost full of waste ink. Can be determined to be. Also,
If the final portion 126 is not discolored but most of the second portion 124 is discolored, it can be predicted that the final portion 126 will soon absorb waste ink and the waste ink recovery device 100 will be full of waste ink. . If neither the second part 124 nor the final part 126 is discolored, it can be determined that the waste ink can still be absorbed.

An opening 11 is provided below the waste ink tank 110.
The main body-side absorber 140 is inserted into the opening 113 and comes into contact with the first portion 122. The main body side absorber 140 is held by a prismatic holding member 142 and connected to a tube 144 through which waste ink flows. The holding member 142 is fixed to the main body 150 of the plotter 10 (see FIG. 1) by a pair of guide bars 146.
Each of the pair of guide rods 146 has a compression coil spring 14.
8 is fitted and urges the holding member 142 toward the waste ink collecting device 100. As a result, when the waste ink collecting device 100 is mounted on the main body 150, the main body side absorber 140 and the first portion 122 of the ink absorber 120 are surely in contact with each other.

When the waste ink collecting device 100 is mounted on the main body 150 of the plotter 10, the waste ink is removed from the tube 144.
Is absorbed by the main body side absorber 140 and further absorbed by the first portion 122 of the ink absorber 120. When the first portion 122 is substantially full of waste ink, the second portion 124
Begins to absorb waste ink. When this second portion 124 is substantially full of waste ink, the final portion 126 begins to absorb waste ink. As described above, each portion 122, 124,
Reference numeral 126 denotes a color change when waste ink is absorbed, so that the ink absorbing material 12 is moved through the transparent windows 112a, 112b, and 112c.
By observing 0, it is possible to reliably and accurately determine when to replace the waste ink recovery device 100 (or the ink absorber 120).

[0038]

As described above, in the waste ink collecting apparatus of the present invention, when the ink is absorbed in the final portion of the ink absorber, it can be determined that the ink absorber is almost full. Therefore, by observing the final portion from the transparent window, it is possible to visually determine whether or not the waste ink collecting device is full with the collected waste ink. In addition, since the final portion is discolored by absorbing ink, if the final portion is discolored, it can be determined that the ink absorber is almost full. As described above, it is possible to determine whether or not the ink absorber is full with the ink based on whether or not the final portion has changed color. Therefore, whether or not the collected waste ink is full can be easily and reliably visually determined. In addition, since the second transparent window for observing the second portion absorbing the waste ink before the final portion is provided, it is visually confirmed from the second transparent window whether the second portion has absorbed the waste ink. it can. This second part absorbs waste ink before the last part absorbs waste ink, so when the second part is absorbing waste ink, the last part will soon absorb waste ink and become full. It can be predicted that Therefore, it is possible to prevent the waste ink from overflowing from the waste ink collecting device. Further, since the second portion is discolored by absorbing the ink, when the second portion is discolored, it can be expected that the final portion will soon absorb the waste ink and become full. In this manner, it can be predicted that the final portion will soon absorb the waste ink and become full, depending on whether or not the second portion has discolored. Therefore, it is possible to easily and reliably prevent a situation where the waste ink overflows from the waste ink recovery device. Can be prevented.
Further, a new ink absorber for replacement can be prepared.

In the case where the second portion has a higher suction force for sucking up waste ink than the final portion, the ink absorber has the second portion and the second portion which are weaker in the suction force. Since the two parts are distinguished, a relatively simple configuration is sufficient.

In the case where the second portion is discolored before the final portion is discolored, the discoloration of the second portion may cause the ink absorber to be soon filled with waste ink. Therefore, a new ink absorber for replacement can be prepared with a margin.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a plotter in which a waste ink collecting device of the present invention is incorporated.

FIG. 2 is a cutaway perspective view of a first embodiment of the waste ink collecting device.

FIG. 3 is a sectional view taken along line DD of FIG. 2;

FIG. 4 is a perspective view showing a second embodiment of the waste ink collecting device.

FIG. 5 is a sectional view taken along line GG of FIG. 4;

[Explanation of symbols]

 10 Plotter 40, 100 Waste ink recovery device 60, 120 Ink absorber 64, 124 Second part 66, 126 Final part 54, 112a, 112b, 112c Transparent window

Claims (3)

[Claims] 1. An ink jet type image forming apparatus which forms an image on a recording medium by discharging ink from said nozzle while reciprocating a print head having a nozzle for discharging ink in a predetermined direction. Alternatively, in the waste ink collecting device provided with an ink absorber in which the sucked waste ink is absorbed, the ink absorber includes a final portion that absorbs waste ink lastly, and a waste ink that is earlier than the final portion. A waste ink collecting device, comprising: a second portion that absorbs light; and a transparent window that observes the final portion and the second portion. 2. The waste ink collection according to claim 1, wherein the ink absorber has a stronger suction force for sucking up waste ink in the second portion than in the final portion. apparatus. 3. The waste ink recovery device according to claim 1, wherein the second portion changes color before the final portion changes color.