JP2002019149A - Image forming device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To allow waste ink sucked from a discharge port of an ink jet type head to flow smoothly without staying in an ink discharge path. SOLUTION: A hollow and cylindrical waste ink accumulating unit 110 is provided.
Are provided with connecting portions 110K, 110C, 110M, and 110Y for connecting suction tubes of each color. Portion where each connection section is connected to the main body of waste ink accumulation section 110 (portion flowing into waste ink accumulation section 110)
The height of the connection portion 110K for the pigment ink is located at the lowest position, and the connection portions 110C and 110C for the dye ink are located thereon.
M and 110Y are provided. With such a configuration, the dye ink comes into contact with the pigment black ink while flowing from above and pushes the pigment ink away, so that the highly viscous pigment ink can be prevented from staying in the waste ink accumulation unit 110.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet type image forming apparatus provided with a mechanism for sucking waste ink from a discharge port of a print head.

[0002]

2. Description of the Related Art One of image forming methods in an image forming apparatus such as a printer or a plotter is an ink jet method. This method is being used in a wide range of applications because of its features such as high-quality printing, easy colorization, and low noise.

An ink jet type image forming apparatus forms an image on a recording medium such as paper by continuously performing an operation of discharging ink at predetermined timing from a discharge port provided in a print head. In this case, if printing is performed continuously for a long time, ink bubbles may accumulate in the ejection openings of the head, or foreign matter may enter the ejection openings, causing clogging, etc. Cannot be performed, and the quality of the formed image may be degraded. For this reason, there is a device provided with a device (recovery device) that forcibly sucks ink from the ejection port at a predetermined timing to always restore the state of the ejection port to a state optimal for ink ejection. .

The waste ink sucked from the discharge port by the recovery device is finally sent to a waste ink tank installed in the main body of the image forming apparatus via an ink discharge path, where the waste ink is accumulated, and a certain amount is accumulated. Collectively discarded in stages.

[0005]

By the way, the waste ink sucked out from the discharge port by the recovery device sometimes stays in the ink discharge path in the middle of being sent to the waste ink tank, and does not flow to the destination. Such a phenomenon occurs more frequently as the waste ink tank cannot be installed near the recovery device due to the space of the image forming apparatus and the ink discharge path has to be lengthened. This is because the sucked waste ink thickens before reaching the waste ink tank, and therefore, the higher the viscosity of the ink, the easier it is to thicken, the easier it is to stay in the ink discharge path. Tend.

If the ink thickens and stays in the ink discharge path, the flow of the ink in the ink discharge path stagnates, which also affects the operation of the suction mechanism of the recovery device, and the recovery operation does not work well. Affects the image formed on the recording material.

SUMMARY OF THE INVENTION The present invention has been made in view of such a technical background, and an object of the present invention is to provide an ink jet type image forming apparatus having a mechanism for sucking waste ink from a discharge port of a print head. The purpose is to allow the waste ink sucked from the discharge port of the print head to flow smoothly without staying in the ink discharge path.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, an image is formed on a recording material by discharging a plurality of inks having different viscosities from respective discharge ports to the recording material. In addition, in the image forming apparatus provided with a mechanism for discharging ink from each of the discharge ports, a waste ink accumulation unit where waste ink discharged from each of the discharge ports joins, wherein waste ink is discharged from each of the discharge ports. A waste ink accumulation, wherein at least one waste ink inlet having a relatively low viscosity is provided at a position higher than the waste ink inlet having a relatively high viscosity among the plurality of inflow inlets. It has a part.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, among the respective inlets provided in the waste ink accumulating portion, the inlet for the waste ink having the highest viscosity is replaced with another. Are provided at a position lower than all waste ink inlets.

According to a third aspect of the present invention, there is provided a mechanism for discharging a plurality of inks having different viscosities from respective discharge ports to a recording material to form an image on the recording material and discharging ink from the respective discharge ports. In the image forming apparatus, a waste ink collecting unit into which the waste ink sucked from each of the discharge ports merges, and among a plurality of inflow ports into which the waste ink flows from each of the discharge ports, there is a viscosity when viewed from the outflow port. And a waste ink accumulating portion provided with at least one of the waste ink inlets having relatively low viscosity at a position farther than the waste ink inlet having a relatively high waste ink concentration.

According to a fourth aspect of the present invention, in the image forming apparatus according to the third aspect, among the respective inlets provided in the waste ink collecting section, the inlet for the waste ink having the highest viscosity is provided. It is characterized by being provided at a position closest to the outlet.

According to a fifth aspect of the present invention, there is provided a mechanism for discharging a plurality of inks having different viscosities from respective discharge ports to a recording material to form an image on the recording material, and discharging the ink from the respective discharge ports. In the image forming apparatus, the waste ink collecting unit into which the waste ink discharged from each of the discharge ports merges, wherein the viscosity is relatively high among a plurality of inlets into which the waste ink flows from each of the discharge ports. A waste ink accumulating portion having a groove for holding waste ink, which connects at least one of the waste ink inlet and the relatively low viscosity waste ink inlet; It is characterized by.

According to a sixth aspect of the present invention, there is provided a mechanism for discharging a plurality of inks having different viscosities from respective discharge ports to a recording material to form an image on the recording material, and discharging the ink from the respective discharge ports. In the image forming apparatus, the waste ink collected by the waste ink discharged from each of the discharge ports merges, and the volume of the waste ink is reduced by the amount of waste ink sucked by the single suction operation from each of the discharge ports. It is characterized by having a waste ink accumulation unit smaller than the total.

According to a seventh aspect of the present invention, there is provided a mechanism for ejecting a plurality of inks having different viscosities to the recording material from the respective ejection ports to form an image on the recording material and discharging the ink from the respective ejection ports. A waste ink collecting unit into which the waste ink discharged from each of the discharge ports merges, wherein a predetermined amount of the relatively low-viscosity waste ink among the plurality of waste inks is absorbed therein. And a waste ink accumulating unit for increasing the internal humidity by vaporizing the relatively low-viscosity waste ink held by the ink absorber.

According to an eighth aspect of the present invention, in the image forming apparatus according to the seventh aspect, the waste ink accumulating section contacts a relatively viscous waste ink among the plurality of waste inks with the ink absorber. It is characterized by not being configured.

According to a ninth aspect of the present invention, there is provided a mechanism for discharging a plurality of inks having different viscosities from respective discharge ports to a recording material to form an image on the recording material, and discharging the ink from the respective discharge ports. The waste ink discharged from each of the discharge ports has a waste ink collecting unit, and at least one of the waste inks having a relatively high viscosity flows into the waste ink collecting unit. Characterized in that waste ink having a relatively low viscosity flows in.

According to a tenth aspect of the present invention, in the image forming apparatus according to the ninth aspect, the mechanism for sucking the waste ink includes a pressing member provided around a cylindrical rotating means for each waste ink conduit. Rotating the rotating means while pressing to suck waste ink from each of the discharge ports,
By changing the position of each pressing member around the rotating means, the relatively high-viscosity waste ink temporally precedes at least one kind of the relatively low-viscosity waste ink. It is characterized by flowing into the part.

[0018] The invention described in claim 11 is the invention according to claims 1 to 1
0, wherein the relatively viscous waste ink is a pigment ink and the relatively low viscosity waste ink is a dye ink.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. First, before describing each embodiment, an overall description of the plotter 1 will be given with reference to FIGS.

FIG. 1 is a schematic perspective view of an ink-jet type plotter to which the present invention is applied. Plotter 1
The user can operate various buttons provided on the operation unit 2 to perform various settings required for image formation. The recording medium (not shown) on which an image is formed has an opening 3
Is inserted and set from the back side. The set recording material is nipped by the conveying roller 4 and a pinch roller (not shown), and an image is formed while being conveyed in the direction indicated by the arrow X.

At the bottom of the main body of the plotter 1 shown in FIG.
A waste ink tank 5 is provided. As will be described later, the plotter 1 performs a head recovery operation at a fixed timing in order to maintain good print quality. This recovery operation includes a suction operation for forcibly sucking ink from the ejection openings of the head. The waste ink generated during this suction operation is finally sent to the waste ink tank 5.

FIG. 2 shows one of the plotters 1 shown in FIG.
It is the schematic front view which showed the mode inside the main body cover. A scanning rail 8 is provided in a longitudinal direction of the main body (a direction indicated by an arrow Y), and a carriage 6 is attached to the scanning rail 8. The carriage 6 reciprocates in the Y direction on the scanning rail 8 by a motor and a belt (not shown).

The plotter 1 performs color printing using four color inks. These inks are supplied from a not-shown ink tank to corresponding heads. Here, a pigment ink is used as the black (K) ink, and a dye ink is used as each of the cyan (C), magenta (M), and yellow (Y) inks. The reason for using only black pigment ink is to enable high density printing. Further, a print head corresponding to each of these color inks is provided below the carriage 6.

In FIG. 2, the carriage 6 is located on the right side of the main body.
And a recovery device 9 for recovering the ejection port surface of the head that has performed the printing operation for a certain period to a favorable state. The recovery device 9 includes a suction mechanism for sealing the ejection port surface and sucking ink from the ejection port of the head, and a wiping blade for wiping the ejection port surface. The ink sucked from each head by the suction mechanism is mixed when passing through a waste ink accumulation unit described later, and then sent to the waste ink tank 5.

[Embodiment 1] FIG. 3 is a sectional view showing an ink suction mechanism according to Embodiment 1, and FIG. 4 is a view of a part of the suction mechanism shown in FIG. is there. This suction mechanism includes a cap 11 for sealing the ejection port of the recording head.
1, a cap holder 112 that supports the cap 111,
The suction tube 117 (117K, 117C, 1C) for each color that connects the cap 111 and the waste ink accumulation unit 110
17M, 117Y), the four pressure rollers 11 rotating while pressing each suction tube 117 against the curved wall 113.
4 (114K, 114C, 114M, 114Y), a roller holder 115 that is rotatably mounted while holding each pressure roller 114 in a rotatable manner, and a waste ink accumulating unit 1.
It is configured to include a waste ink tube 118 that connects the waste ink tank 5 to the waste ink tank 5. A period in which each pressure roller 114 presses the corresponding suction tube 117 against the wall 113 is a period during which the roller holder 115 rotates about 90 degrees.

FIGS. 5A and 5B show the waste ink accumulating unit 110. FIG. 5A is a perspective view of the same, and FIG. 5B is a plan view seen from above. As shown in FIG. 5, the main body of the waste ink accumulating unit 110 has a hollow cylindrical shape, and connection portions 110K, 110C, 110M for connecting the suction tubes 117K, 117C, 117M, and 117Y are provided on the peripheral side surface. , 110
Y is provided. An outlet 110a is provided in the lower part of the main body. The ink of each color that has passed through the suction tube 117 flows into the main body from the corresponding connection part, is mixed in the main body, and is then sent from the outlet 110 a to the waste ink tank 5 through the waste ink tube 118.

As shown in FIG. 3 to FIG.
The height of the portion where 10K, 110C, 110M, and 110Y are connected to the main body of the waste ink accumulating portion 110 (the portion where the ink flows into the main body) is the connecting portion 110K for black ink.
Is located at the bottom, and the connection 1 for cyan ink
10C is provided, and a connection portion 110M for magenta ink is further provided thereon, and a connection portion 110Y for yellow ink is provided at the highest position. FIG.
As shown in (b), the connection portion 110 for black ink
Three connection parts 110C, 110M, 110Y except K
Are arranged at regular intervals of 120 degrees around the central axis of the main body.

When performing a head recovery operation, first,
The carriage 6 returns to the home position and the recovery device 9
(See FIG. 1). The ejection openings of the heads corresponding to each color mounted on the carriage 6 are sealed by the cap 111 on the cap holder 112. In this state, the roller holder 115 rotates counterclockwise in FIG. Then, each pressure roller 114 moves from the upstream side to the downstream side of the suction tube 117 with the corresponding suction tube 117 pressed against the curved wall 113. As a result, the inside of the cap 111 becomes a negative pressure, and the ink in the discharge port of the head is sucked out along the suction tube 117 and flows toward the waste ink accumulation unit 110.

As described above, since the pigment black ink has a high viscosity and is liable to increase in viscosity, the waste ink accumulation unit 11
It is easy to stay within 0. However, as described above, since the connection portion 110K for the pigment black ink is located at the lowest position among the connection portions provided in the waste ink accumulation portion 110,
Even if the pigment black ink thickens in the waste ink accumulation unit 110, the pigment black ink does not stay at a position higher than the other connection units 110C, 110M, and 110Y. Therefore, when other dye inks flow into the waste ink accumulation unit 110 from the connection units 110C, 110M, and 110Y, they come into contact with the retained pigment black ink.

As described above, the dye ink has a low viscosity and flows smoothly without stagnation. Therefore, when the dye ink comes into contact with the pigment black ink while flowing from the upstream, there is an effect of preventing the stagnation of the pigment ink by flushing the pigment ink. . In addition, when dye ink mixes with highly viscous pigment ink, it acts to lower the overall viscosity, so when touching pigment ink that is thickened and stays, it dissolves the remaining pigment ink and makes it easier to flow. There is. Therefore, by configuring the waste ink accumulation unit 110 as described above,
As a whole, it is possible to suppress the accumulation of waste ink and make it flow smoothly.

In consideration of effective prevention of thickening and stagnation of the pigment black ink, as described later, the connection portion 110K for the pigment black ink is connected to all the other connection portions 110C, 110M, and 110Y. Is desirably provided below. However, the present invention is not limited to such a case. For example, even if only one connection portion for dye ink is provided above the connection portion for pigment ink, the technical scope of the present invention include. This is because if at least one connection portion for the dye ink is provided above the connection portion for the pigment ink, the effect that the dye ink flowing in from the connection portion flushes the pigment ink or dissolves the pigment ink to facilitate the flow. Is obtained.

Also, three connection parts 110C, 110M,
The reason why the 110Ys are arranged at equal intervals of 120 degrees around the central axis of the main body is to take into account that the dye ink easily travels along the entire inner wall of the main body. It goes without saying that it is included in the technical scope of the invention.

[Second Embodiment] FIG. 6 is a sectional view showing a peripheral portion of a waste ink accumulation section 210 in an ink suction mechanism according to a second embodiment. This suction mechanism includes a suction tube 217 (217K, 217C, 217) for each color.
M, 217Y), each suction tube 217 is a wall (not shown)
Four pressing rollers 214 (21
4K, 214C, 214M, 214Y), each pressure roller 2
It is configured to include a roller holder 215 that is rotatably mounted on itself while rotatably holding the roller 14, and a waste ink tube 218 that connects the waste ink accumulation unit 210 and the waste ink tank.

As for the cap 111, the cap holder 112, and the waste ink tank 5 described in the description of the first embodiment, similar ones can be used in the present embodiment. Further, at the time of the recovery operation, the operation of sucking out the ink in the ejection opening of the head along the suction tube 217 by using the roller holder 215 and the pressure rollers 214 is the same as in the first embodiment.

FIG. 7 shows a waste ink accumulating section 21 according to this embodiment.
0 is shown, (a) is a perspective view thereof, and (b) is a cross-sectional view in which one connecting portion is vertically cut. The shape of the waste ink accumulation unit 210 of the present embodiment is shown in FIG.
As shown in (a)), it is substantially cylindrical as a whole, and the four connecting portions 210K, 210C, and 210 are arranged in order from the left side in FIG.
M and 210Y are provided along the longitudinal direction. As shown in FIG. 6, each of the connection portions 210K, 210C, 210M, 210Y has a corresponding suction tube 217K,
7C, 217M and 217Y are connected. An outlet 210a is provided at the left end. When the waste ink collecting unit 210 is installed, as shown in FIGS. 6 and 7A, the side of the outlet 210a is low, and the side of the connection unit 210Y for dye yellow ink is high.

Here, among the suffixes attached to the reference numerals indicating the connection portions and the suction tubes, "K" is for pigment black ink, "C" is for dye cyan ink, "M" is for dye magenta ink, and "M" is for dye magenta ink. "Y" indicates the dye yellow ink is the same as in the first embodiment.

As described above, since the pigment black ink has a high viscosity and is liable to increase in viscosity, the waste ink accumulation section 21
0 and easily stays on the inner wall. However, as described above, since the connection portion 210K for the pigment black ink is provided at the lowest position among the connection portions provided in the waste ink accumulation portion 210, the pigment black ink is Even if the viscosity increases with the other connection parts 210C, 2
It does not stay at a position higher than 10M, 210Y. Therefore, other dye inks are connected to the connection parts 210C, 21C.
When they flow into the waste ink accumulation unit 210 from the OM and 210Y, they come into contact with the retained pigment black ink.

As described above, the dye ink has a low viscosity and flows smoothly without stagnating. Therefore, when the dye ink contacts the pigment black ink while flowing from the upstream, there is an effect of preventing the stagnation of the pigment ink by flushing the pigment ink. . In addition, when dye ink mixes with highly viscous pigment ink, it acts to lower the overall viscosity, so when touching pigment ink that is thickened and stays, it dissolves the remaining pigment ink and makes it easier to flow. There is. Therefore, by configuring the waste ink accumulation unit 210 as described above,
Stagnation of waste ink can be suppressed, and the entire ink can flow smoothly.

In consideration of effective prevention of thickening and stagnation of the pigment black ink, the connection portion 210K for the pigment black ink is connected to all the other connection portions 210C, 210M, and 210Y as described above. Is desirably provided at a lower position. However, the present invention is not limited to such a case. For example, even when only one connection portion for dye ink is provided at a position higher than the connection portion for pigment ink, the technology of the present invention may be used. Included in the target range.
This is because if at least one connection portion for the dye ink is provided above the connection portion for the pigment ink, the effect that the dye ink flowing in from the connection portion flushes the pigment ink or dissolves the pigment ink to facilitate the flow. Is obtained.

[Embodiment 3] FIG. 8 is a front view showing a peripheral portion of a waste ink accumulation section 310 in an ink suction mechanism according to Embodiment 3. This suction mechanism includes a suction tube 317 (317K, 317C, 317) for each color.
M, 317Y), wall each suction tube 317 (not shown)
Four pressing rollers 314 (31
4K, 314C, 314M, 314Y), each pressure roller 3
It is configured to include a roller holder 315 that is rotatably mounted on itself while holding the rotatable unit 14, and a waste ink tube 318 that connects the waste ink accumulation unit 310 and the waste ink tank 5. Of the suffixes attached to the reference numerals indicating the connection portions and the suction tubes, “K” is for pigment black ink, “C” is for dye cyan ink, “M” is for dye magenta ink, “Y” is dye yellow ink. This is the same as in the first and second embodiments.

As for the cap 111 and the cap holder 112 described in the description of the first embodiment, the same ones can be used as they are in the present embodiment. Also,
During the recovery operation, the roller holder 315 and each pressure roller 31
Use the suction tube 3 to remove the ink in the ejection port of the head using
The operation of sucking out along line 17 is the same as that of the first embodiment.

FIG. 9 shows a waste ink accumulating section 31 according to this embodiment.
0 is shown, (a) is a perspective view thereof, and (b) is an enlarged sectional view showing a state where one connecting portion 310C is cut vertically.

As shown in FIG. 9A, the shape of the waste ink accumulating portion 310 of this embodiment is an inverted triangle as a whole, the inside is hollow, and the upper portion has four connecting portions 310K,
310C, 310M and 310Y are provided. Each connecting part 310K, 310C, 310M, 310Y has a corresponding suction tube 317K, 317C, 3D.
17M and 317Y are connected. Waste ink accumulation unit 3
An outlet 310 a is provided at a lower portion of the waste ink tube 3, and the waste ink tube 3 connected to the waste ink tank 5 is provided here.
18 are connected.

As shown in FIG. 9, each of the connection portions 310K, 3K
10C, 310M and 310Y are the waste ink accumulating units 310
Are disposed linearly at the upper part of the
9 (b) between the connecting portions of the upper wall in FIG.
As shown in detail in FIG. The groove 330 has, for example, a width of 1 mm and a depth of 1.5 m.
m.

In the waste ink collecting section 310, such a groove 33 is provided.
By providing 0, the ink that has reached the lower end of the connection portion from the discharge port of the head through the inner wall of the suction tube 317 does not immediately drop, but instead, due to the capillary action of the liquid and the surface tension, the groove 330 is formed. Flows horizontally in the interior. Then, a certain amount of ink is held on the inner wall of the waste ink accumulation unit 310 along the groove 330.

As described above, the waste ink is stored in the waste ink accumulation unit 3.
When held on the upper inner wall of 10, the inks of each color mix with each other. Dye ink acts to lower the overall viscosity when mixed with highly viscous pigment ink, so when touching pigment ink that is thickened and stays, it has the effect of dissolving the staying pigment ink and making it easier to flow . When the mixed ink exceeds the amount that can be held by the groove 330 as a whole, the mixed ink starts dropping from the groove 330 and smoothly flows out of the outlet 310.
a flows out to the waste ink tube 318. Therefore, the accumulation of the waste ink in the waste ink accumulation unit 310 can be suppressed, and the waste ink can be smoothly guided to the waste ink tank 5.

In the above description, the groove 330 is formed so as to connect all the connecting portions. However, the groove 310 is formed so as to connect the connecting portion 310K for the pigment black ink to at least one of the connecting portions for the other dye ink. Then, the effect of suppressing the increase in the viscosity of the pigment black ink by mixing the two inks can be obtained. In the examples shown in FIGS. 8 and 9,
Although the connecting portion 310K for the pigment black ink is provided at the end, the connecting portion 310K may be provided at a position other than the end (the second or third position from the left). It becomes easy to mix.

Further, as shown in FIG. 10, the waste ink accumulating section 310 has a shape in which the upper portion of the main body is substantially triangular, and the connecting section 310K for the pigment black ink is located at the center, and the connecting sections for the other three dye inks are arranged. 310C, 310M, 310Y
May be provided around it, and a groove 330 may be provided between the connection portion 310K and the other connection portions 310C, 310M, 310Y. In this case, the pigment ink is more easily mixed with the dye ink, and the effect of suppressing the increase in the viscosity of the pigment black ink is enhanced.

[Fourth Embodiment] FIG. 11 is a front view showing a peripheral portion of a waste ink accumulation section 410 in an ink suction mechanism according to a fourth embodiment. The suction mechanism includes a suction tube 417 (417K, 417C, 417) for each color.
M, 417Y), each suction tube 417 is a wall (not shown)
Four pressing rollers 414 (41
4K, 414C, 414M, 414Y), each pressing roller 4
It is configured to include a roller holder 415 that is rotatably mounted on itself while holding the rotatable unit 14, and a waste ink tube 418 that connects the waste ink accumulation unit 410 and the waste ink tank. Of the suffixes attached to the reference numerals indicating the connection portions and the suction tubes, “K” is for pigment black ink, “C” is for dye cyan ink, “M” is for dye magenta ink, “Y” is dye yellow ink. This is the same as in the first to third embodiments.

As for the cap 111 and the cap holder 112 described in the description of the first embodiment, the same ones can be used as they are in the present embodiment. Also,
During the recovery operation, the roller holder 415 and each pressure roller 41
The ink in the discharge port of the head is sucked using the suction tube 4.
The operation of sucking out along line 17 is the same as that of the first embodiment.

As shown in FIG. 11, the shape of the main body of the waste ink accumulating section 410 of this embodiment is a long and thin linear shape as a whole, and the volume inside the main body is increased by a single suction operation. Is designed to be smaller than the maximum ink suction amount sucked from the discharge port of the ink jet printer. FIG.
1, four connecting portions 410K along the longitudinal direction from the left side,
410C, 410M and 410Y are provided. Each connecting part 410K, 410C, 410M, 410Y has a corresponding suction tube 417K, 417C,
17M and 417Y are connected. Waste ink accumulation unit 4
An outlet 410a is provided at the left end portion of 10, and a waste ink tube 418 connected to a waste ink tank is connected to the outlet 410a.

As described above, the volume inside the main body of the waste ink accumulation section 410 is made smaller than the suction amount of one suction operation,
In addition, by providing the connection portion 410K for the highly viscous pigment black ink closest to the outlet 410a, the pigment black ink thickens and stays in the waste ink accumulation unit 410 and stays in the waste ink accumulation unit 410 main body. Even if the flow path is blocked, another dye ink flowing from the upstream in the waste ink accumulation unit 410 comes into contact with the pigment black ink and tries to wash it away. Therefore, as a result, the waste ink does not stay in the waste ink accumulation unit 410, and is reliably sent out from the outlet 410a toward the waste ink tank.

In order to effectively remove the pigment black ink by the dye ink, it is desirable to provide the connection portion 410K for the pigment black ink closest to the outlet 410a as described above. Is at least one upstream of the connection 410K for the pigment black ink, the minimum effect can be obtained.

[Fifth Embodiment] FIG. 12 is a longitudinal sectional view showing a peripheral portion of a waste ink accumulation section 510 in an ink suction mechanism according to a fifth embodiment. As shown in FIG. 12, the shape of the waste ink accumulation unit 510 of the present embodiment is a substantially inverted triangle as a whole, and four connection units 510K, 510C, 510M, and 510Y are arranged at substantially equal intervals from the left side of FIG. Is provided. Each connection part 510K, 510C, 510
M and 510Y have corresponding suction tubes 5
17K, 517C, 517M and 517Y are connected. An outlet 510a is provided below the waste ink accumulation unit 510.
Is provided, and a waste ink tube 518 connected to the waste ink tank is connected to this.

In addition, among the suffixes attached to the reference numerals indicating the connection portions and the suction tubes, “K” is for pigment black ink, “C” is for dye cyan ink, “M” is for dye magenta ink, and “Y”. "For dye yellow ink is the same as in Embodiments 1 to 4. Further, the same caps 111 and cap holders 112 described in the description of the first embodiment can be used as they are in the present embodiment. Further, at the time of the recovery operation, the operation of sucking the ink in the ejection opening of the head along the suction tube 517 by using the roller holder and each pressure roller is also the same as that of the first embodiment.

FIG. 12 shows the inside of the waste ink accumulation unit 510.
As shown, a wall 550 is provided. Wall 550
Is the connection portion 5 for the pigment black ink provided on the leftmost side.
10K and connection part 510C for dye cyan ink on the right side
In between, it is formed so as to protrude downward from the upper portion of the inner wall. Of the inside of the waste ink accumulation unit 510,
An ink absorber 560 occupying the entire space is provided in the right space partitioned by the wall 550. As the ink absorber 560, a material that easily absorbs liquid, such as foamable urethane or polypropylene foam, is used.

The ink of each color sucked at the time of the recovery operation reaches the waste ink collecting section 510 through the corresponding suction tube 517. Of these, the dye inks other than the pigment black ink correspond to the corresponding connection portions 510C and 510C.
M and 510Y enter the waste ink accumulation unit 510 and are absorbed by the ink absorber 560. The ink absorber 560 continues to absorb ink until a certain amount of ink flows in, and after that, the ink flows down in the waste ink accumulation unit 510 and flows out from the outlet 510a to the waste ink tube 518. Therefore, after the recovery operation is performed for the first time, the state where the fixed amount of the dye ink is held in the ink absorber 560 continues.

On the other hand, the pigment black ink is
0K, enters the waste ink accumulation unit 510, flows down the inner wall of the waste ink accumulation unit 510, and finally reaches the outlet 5
10a flows out to the waste ink tube 518. At this time, when the pigment black ink comes into contact with the ink absorber 560, the pigment black ink is absorbed by the ink absorber 560 and may thicken internally. However, the provision of the wall 550 allows the pigment black ink to absorb the ink. Contact with the body 560 can be prevented.

Since the pigment ink has a high viscosity, if it is merely flowing along the inner wall of the waste ink accumulating portion 510, the viscosity increases and the flow becomes difficult, and the pigment ink may adhere to the inner wall. However, as described above, if a sufficient amount of dye ink is held in the ink absorber 560, vaporization of the low-viscosity dye ink is promoted, so that the inside of the waste ink accumulation unit 510 is kept in a high humidity state. Dripping. By increasing the humidity inside the waste ink accumulation unit 510 in this way, it is possible to suppress the increase in the viscosity of the pigment ink due to excess moisture in the waste ink accumulation unit 510. When the viscosity of the pigment ink is suppressed, the pigment ink hardly adheres to the inner wall, and as a result, the pigment ink flows smoothly in the waste ink accumulation unit 510.

When the plotter to which the suction mechanism of the present embodiment is applied is used first, or when the plotter is not used for a long period of time, the ink absorber 560 does not absorb the dye ink. In such a case, if a low-viscosity liquid such as water is absorbed in the ink absorber 560 before use, the ink is used again for the first time or after a long period of non-use. In this case, the viscosity of the pigment ink in the waste ink accumulation unit 510 can be prevented from increasing.

Sixth Embodiment FIG. 13 is a sectional view showing an ink suction mechanism according to a sixth embodiment, and FIG.
3 is a view of a part of the suction mechanism shown in FIG.

The suction mechanism of the present embodiment includes a cap 611 for sealing the discharge port of the recording head, a cap holder 612 for supporting the cap 611, and a suction tube 61 for each color for connecting the cap 611 and the waste ink accumulating section 610.
7 (617K, 617C, 617M, 617Y), four pressing rollers 614 (614K, 614C, 614C) rotating while pressing each suction tube 617 against the curved wall 613.
614M, 614Y), and includes a roller holder 615 that is rotatably mounted on itself while holding each pressure roller 614 rotatably. The period in which each pressure roller 614 presses the corresponding suction tube 617 against the wall 613 is during the rotation of the roller holder 615 by about 90 degrees.

As shown in FIG. 14, the waste ink accumulating section 610 of this embodiment has an inverted triangle as a whole, is hollow inside, and has four connecting sections 610K, 610C, 6
10M and 610Y are provided. Each connection part 610
K, 610C, 610M, and 610Y have corresponding suction tubes 617K, 617C, 617M, and 6 respectively.
17Y is connected. An outlet 610a is provided below the waste ink accumulation unit 610, and a waste ink tube 618 connected to the waste ink tank 5 is connected to the outlet 610a. However, the waste ink accumulation unit that can be used in the present embodiment is not limited to those shown in FIGS.
The waste ink accumulating unit in each of the above-described embodiments and other units may be used.

A characteristic of the suction mechanism of this embodiment is that, as shown in FIGS.
14K, 614C, 614M and 614Y are shifted by 90 degrees around the roller holder 615. The standby position of the roller holder 615 in the initial state is the pressure roller 614 for the pigment black ink.
K is in a position immediately before contacting the suction tube 617K.

When the head recovery operation is performed, the roller holder 615 rotates counterclockwise in FIG. 13 with the ejection openings of the heads of the respective colors sealed with the caps 611. Then, each pressure roller 614 moves from the upstream side to the downstream side of the suction tube 617 while pressing the corresponding suction tube 617 against the curved wall 613. As a result, the inside of the cap 611 becomes a negative pressure, and the ink in the discharge port of the head is sucked out along the suction tube 617 and flows toward the waste ink accumulation unit 610.

As described above, in the initial state, the pressure roller 61
Since 4K is located immediately before contacting the suction tube 617K, when the suction operation is started, the pigment black ink is first suctioned, and subsequently, every time the roller holder 615 rotates 90 degrees, The ink to be sucked is switched, and the dye cyan ink, the dye magenta ink, and the dye yellow ink are sucked in this order.

In this way, the pigment black ink is first sucked and flows into the waste ink accumulation section 610, and thereafter, the other dye inks sequentially flow into the waste ink accumulation section 610. The pigment black ink is highly viscous and thickens and adheres to the inner wall of the waste ink accumulation unit 610 and easily stays. However, even if the pigment ink slightly thickens, the low-viscosity dye ink flowing later increases in viscosity. Since the pigment ink is washed away, the pigment ink is collected in the waste ink accumulation unit 61.
It can be prevented from adhering and staying on the inner wall of the zero.

In the example shown in FIGS. 13 and 14,
Each pressure roller 614 is arranged around the roller holder 615 so that the pigment black ink is suctioned earlier than all the other dye inks, but at least one dye ink is suctioned after the pigment black ink. In this case, the dye ink has an effect of flushing the highly viscous pigment black ink. Further, the suction mechanism of the present embodiment may be any suction mechanism in which relatively low-viscosity ink flows into the waste ink accumulation unit 610 after relatively high-viscosity ink. , The pressure roller 614 and the roller holder 61 as described above.
5 is not limited.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, but falls within the scope of the invention described in each claim. In the above, various modifications are possible, which are also included in the technical scope of the present invention.

[0070]

As described above, according to the present invention,
Even when a highly viscous ink such as a pigment ink is used, the waste ink accumulation unit mixes a relatively low-viscosity waste ink, such as a dye ink, with a highly viscous waste ink. By using the vaporization effect of low-waste waste ink, it is possible to suppress thickening of highly viscous waste ink. As a result, it is possible to prevent waste ink from accumulating in the waste ink discharge path and to smoothly discharge waste ink. It becomes possible to flow.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a plotter using an inkjet method.

FIG. 2 is a schematic front view showing a state inside a main body cover of the plotter shown in FIG. 1;

FIG. 3 is a cross-sectional view illustrating an ink suction mechanism according to the first embodiment.

4 is a view of a part of the suction mechanism shown in FIG. 3 as viewed from the right side in FIG.

FIG. 5 illustrates a waste ink accumulation unit according to the first embodiment,
(A) is a perspective view thereof, and (b) is a plan view seen from above.

FIG. 6 is a cross-sectional view showing a peripheral portion of a waste ink accumulation section in the ink suction mechanism according to the second embodiment.

FIGS. 7A and 7B show a waste ink accumulating unit according to a second embodiment, in which FIG. 7A is a perspective view of the same, and FIG.

FIG. 8 is a front view illustrating a peripheral portion of a waste ink accumulation section in the ink suction mechanism according to the third embodiment.

9A and 9B show a waste ink accumulation unit according to a third embodiment, in which FIG. 9A is a perspective view of the same, and FIG. 9B is an enlarged cross-sectional view showing a state where one connecting portion is cut vertically. .

FIG. 10 is a perspective view illustrating a modified example of the waste ink accumulation unit according to the third embodiment.

FIG. 11 illustrates an ink suction mechanism according to a fourth embodiment.
FIG. 4 is a front view illustrating a peripheral portion of a waste ink accumulation unit.

FIG. 12 shows an ink suction mechanism according to a fifth embodiment.
FIG. 4 is a longitudinal sectional view illustrating a peripheral portion of a waste ink accumulation section.

FIG. 13 is a cross-sectional view illustrating an ink suction mechanism according to a sixth embodiment.

14 is a view of a part of the suction mechanism shown in FIG. 13 as viewed from the right side in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Plotter 2 ... Operation part 5 ... Waste ink tank 9 ... Recovery device 110, 210, 310, 410, 510, 610 ... Waste ink accumulation part 110a, 210a, 310a, 410a, 510a,
610a ... Outlets 110K, 110C, 110M, 110Y ... Connections 210K, 210C, 210M, 210Y ... Connections 310K, 310C, 310M, 310Y ... Connections 410K, 410C, 410M, 410Y ... Connections 510K, 510C, 510M, 510Y Connections 610K, 610C, 610M, 610Y Connections 111, 611 Caps 112, 612 Cap holders 113, 613 Walls 114, 214, 314, 414, 614 Pressure rollers 115, 215, 315, 415 , 615: Roller holder 116, 217, 317, 417, 517, 617: Suction tube 118, 218, 318, 418, 518, 618: Waste ink tube

Claims (11)

[Claims] 1. An image forming apparatus comprising: a mechanism for ejecting a plurality of inks having different viscosities from a discharge port to a recording material to form an image on the recording material and discharging ink from the discharge ports; A waste ink collecting unit into which the waste ink discharged from each of the discharge ports merges, wherein the flow path for the waste ink having a relatively high viscosity among a plurality of inlets into which the waste ink flows from each of the discharge ports; An image forming apparatus, comprising: a waste ink accumulating section provided with at least one waste ink inlet having a relatively low viscosity at a position higher than the inlet. 2. The inflow port for waste ink having the highest viscosity among the inflow ports provided in the waste ink accumulation section,
2. The image forming apparatus according to claim 1, wherein the image forming apparatus is provided at a position lower than all other waste ink inlets. 3. An image forming apparatus comprising: a mechanism for discharging a plurality of inks having different viscosities from a discharge port to a recording material to form an image on the recording material, and discharging the ink from the discharge ports. A waste ink accumulating unit into which the waste ink discharged from each of the discharge ports merges, wherein the waste ink having a relatively high viscosity as viewed from the flow outlet among the plurality of inlets into which the waste ink flows from each of the discharge ports. An image forming apparatus, comprising: a waste ink accumulating section provided with at least one waste ink inlet having a relatively low viscosity at a position farther than the ink inlet. 4. The inflow port for waste ink having the highest viscosity among the inflow ports provided in the waste ink accumulation section,
The image forming apparatus according to claim 3, wherein the image forming apparatus is provided at a position closest to the outlet. 5. An image forming apparatus comprising: a mechanism for ejecting a plurality of inks having different viscosities from a discharge port to a recording material to form an image on the recording material and discharging ink from the discharge ports. A waste ink collecting unit into which the waste ink discharged from each of the discharge ports merges, wherein the flow path for the waste ink having a relatively high viscosity among a plurality of inlets into which the waste ink flows from each of the discharge ports; An image forming apparatus comprising: an inlet and a waste ink accumulating portion formed with a groove for holding waste ink, which connects at least one of the waste ink inlets having relatively low viscosity. apparatus. 6. An image forming apparatus comprising: a mechanism for ejecting a plurality of inks having different viscosities from a discharge port to a recording material to form an image on the recording material and discharging the ink from the discharge ports. A waste ink accumulation unit into which the waste ink discharged from each of the discharge ports merges, wherein the volume of the waste ink is smaller than the total amount of the waste ink sucked by one suction operation from each of the discharge ports An image forming apparatus having an accumulation unit. 7. An image forming apparatus comprising: a mechanism for ejecting a plurality of inks having different viscosities from a discharge port to a recording material to form an image on the recording material and discharging the ink from the discharge ports. A waste ink accumulating unit into which the waste ink discharged from each of the discharge ports merges, wherein an ink absorbing unit that absorbs and retains a relatively small amount of relatively low-viscosity waste ink among the plurality of waste inks; An image forming apparatus, comprising: a waste ink accumulating unit that is provided with a body and increases the internal humidity by vaporizing a relatively low-viscosity waste ink held by the ink absorber. 8. The waste ink accumulating section is configured so that waste ink having a relatively high viscosity among the plurality of waste inks does not contact the ink absorber. Image forming device. 9. An image forming apparatus comprising: a mechanism for discharging a plurality of inks having different viscosities from a discharge port to a recording material to form an image on the recording material, and discharging the ink from the discharge ports. A waste ink collecting unit into which the waste ink discharged from each of the discharge ports merges, and after the relatively viscous waste ink flows into the waste ink collecting unit, at least one kind of relatively viscous An image forming apparatus wherein low waste ink flows. 10. A mechanism for sucking waste ink, wherein the rotating means is rotated while pressing a pressing member provided around a cylindrical rotating means against a conduit for each waste ink to rotate the waste ink from each discharge port. By changing the position of each pressing member around the rotating means, the relatively viscous waste ink is temporally shorter than at least one type of relatively low viscosity waste ink. The image forming apparatus according to claim 9, wherein the waste ink is caused to flow into the waste ink accumulation unit first. 11. The ink according to claim 1, wherein the waste ink having a relatively high viscosity is a pigment ink, and the waste ink having a relatively low viscosity is a dye ink. The image forming apparatus according to claim 1.