JP2002120385A - Waste ink treatment device for multi-head printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly clean each ink jet head by a small number of pumps in a multi-head printer. SOLUTION: This waste ink treatment device comprises a plurality of head cleaning sections 31 for maintaining a good ejection condition by sucking ink from each ink jet head 7, a single suction pump 33 connected to the plurality of head cleaning sections 31 through ink conveyance tubes 32 and a waste ink tank 36 for reserving the waste ink sucked by the suction pump 33. The suction pump 33 has an equal pressure suction means 34 for sucking the waste ink from each head cleaning section 31 in an equal pressure condition. The equal pressure suction means 34 is so constituted that the diameters of the ink conveyance tubes from the head cleaning sections 31 to the suction pump 33 are the same with each other and the lengths thereof are substantially the same with each other, thereby sucking the waste ink in the equal pressure condition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-head printer having a plurality of printing units for printing on a print medium using an ink-jet head. The present invention relates to a waste ink processing apparatus that performs an appropriate cleaning operation and processes discharged waste ink.

[0002]

2. Description of the Related Art A plurality of printing units for printing on each printing paper, a paper feeding unit for feeding printing papers to the plurality of printing units, and a printing paper discharged from the plurality of printing units are conveyed. A multi-head printer that has a paper output unit that is placed on a paper output table in a stacked state, and is capable of simultaneously producing prints of the same print content or different print contents by simultaneously executing print operations by a plurality of print units. Have been proposed. When an ink jet head is used as a print head of such a multi-head printer, the ink jet head has a head cleaning unit for sucking ink for each ink jet head, and a waste ink processing for collecting waste ink discharged by each cleaning operation. Equipment must be provided.

As shown in FIG. 4, a plurality of head cleaning units 51 provided on each ink jet type head 50 are used as a waste ink processing apparatus of a multi-head printer.
A plurality of suction pumps 53 connected to the respective head cleaning units 51 via the respective ink transport tubes 52; and a plurality of waste ink tanks connected to the respective suction pumps 53 via the respective ink transport tubes 54. 55.

[0005] As shown in FIG. 5, a plurality of head cleaning sections 51 provided in each ink jet head 50 and a single head cleaning section 51 connected to each head cleaning section 51 via an ink transport tube 52. Suction pump 5
3 and a waste ink tank 55 connected to the suction pump 53 via an ink transport tube 54.

In each of the above-described configurations, the ink ejection state of each of the ink jet heads 50 is properly adjusted by, for example, ejecting ink to the plurality of ink jet heads 50 or ejecting ink by an ink suction operation of the head cleaning unit 51. The waste ink discharged by this cleaning operation is sucked by the suction pump 53 and stored in the waste ink tank 55.
In this manner, each ink jet head 50 can eject ink with a predetermined ejection force without causing clogging or the like.

[0006]

However, in the former waste ink processing apparatus, the ink suction force of each head cleaning unit 51 can be adjusted to the same value by adjusting the suction force of each suction pump 53. Suction pump 5
Since the number of ink jet heads 3 is necessary, the number of ink jet heads 50 is high, so that the cost and the space are increased, and the maintenance is complicated.

Further, in the latter waste ink processing apparatus, only one suction pump 53 is required, so that the cost and space are not increased.
Since the lengths of the ink transport tubes 52 from 1 to the suction pump 53 are different from each other, each head cleaning unit 5
1, the ink suction force differs. In this case, there is a problem that proper cleaning is not performed at the portion of the head cleaning 51 having a weak suction force, and that the ink is unnecessarily sucked too much at the portion of the head cleaning portion 51 having a too strong suction force.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems, and a waste ink treatment for a multi-head printer capable of properly cleaning each ink jet head with a small number of suction pumps. It is intended to provide a device.

[0009]

According to a first aspect of the present invention, there is provided a multi-head printer having a plurality of printing units for performing printing on a print medium using an ink-jet head, wherein ink is sucked into each of the ink-jet heads. A plurality of head cleaning units for adjusting the ejection state to appropriate values, connected to the plurality of head cleaning units via an ink transport tube, and provided with a smaller number of suction pumps than the number of the head cleaning units, and A waste ink tank for storing waste ink, wherein the suction pump is provided with a constant pressure suction means for suctioning the waste ink from each of the head cleaning units at a constant pressure.

In the waste ink processing apparatus of this multi-head printer, ink can be suctioned from all head cleaning units at equal pressure by all head cleaning units with a smaller number of suction pumps than the number of ink jet heads.

According to a second aspect of the present invention, there is provided the waste ink processing apparatus for a multi-head printer according to the first aspect, wherein the equal-pressure suction means connects the ink transport tube from each of the head cleaning units to the suction pump. It is characterized in that the suction is performed at the same diameter and the same length so that the suction is performed at an equal pressure.

In this waste ink processing apparatus for a multi-head printer, in addition to the operation of the first aspect of the present invention, the ink from each head cleaning section to the suction pump is adjusted to make the ink suction force of each head cleaning section equal. The transfer tubes having the same diameter and substantially the same length can be used.

According to a third aspect of the present invention, there is provided the waste ink processing apparatus for a multi-head printer according to the first aspect, wherein the equal-pressure suction means comprises: each of the ink transport tubes from each of the head cleaning units to the suction pump. The diameter of each of the ink transport tubes is varied according to the length of the ink transport tube, and suction is performed at an equal pressure.

In the waste ink processing apparatus of the multi-head printer, in addition to the operation of the first aspect of the present invention, in order to make the ink suction force of each head cleaning section equal pressure, the ink from each head cleaning section to the suction pump is controlled. The length of the transfer tube can be set to the shortest.

According to a fourth aspect of the present invention, there is provided the waste ink processing apparatus for a multi-head printer according to any one of the first to third aspects, wherein the number of suction pumps smaller than the number of the head cleaning units is one. It is characterized by.

In this waste ink processing apparatus for a multi-head printer, the minimum number of suction pumps is sufficient in addition to the effects of the first to third aspects of the present invention.

According to a fifth aspect of the present invention, there is provided the waste ink processing apparatus for a multi-head printer according to the first aspect, wherein the number of the waste ink tank is one.

In this waste ink processing apparatus for a multi-head printer, the minimum number of waste ink tanks is sufficient in addition to the effect of the first aspect of the present invention.

According to a sixth aspect of the present invention, there is provided a waste ink processing apparatus for a multi-head printer according to the first aspect, wherein the waste ink tank is detachable from a printing apparatus main body and has a bottle shape. And

In this waste ink processing apparatus for a multi-head printer, in addition to the function of the first aspect of the present invention, when the waste ink becomes full, the waste ink tank is removed from the printing apparatus main body to dispose the waste ink inside. Can be.

According to a seventh aspect of the present invention, there is provided the waste ink processing apparatus for a multi-head printer according to the first aspect, wherein the full ink detecting device detects that the waste ink stored in the waste ink tank is full. A sensor is provided.

In the waste ink processing device of the multi-head printer, in addition to the operation of the first aspect, it is possible to easily recognize when the ink in the waste ink tank is disposed.

According to an eighth aspect of the present invention, there is provided the waste ink processing apparatus for a multi-head printer according to the first aspect, wherein an ink absorber is accommodated in the waste ink tank.

In the waste ink processing apparatus of the multi-head printer, in addition to the function of the first aspect, even when the waste ink tank is inclined due to the inclination of the printing apparatus main body, the internal waste ink easily leaks to the outside. Absent.

[0025]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention, and is a schematic configuration diagram of a multi-head printer equipped with a waste ink processing device.

As shown in FIG. 1, the multi-head printer 1 has a printing unit 2 having six printing stages for printing on printing paper 5 as a printing medium, and the printing paper 5 is supplied to the printing unit 2 having six printing stages. The paper feed unit 3 is provided with a paper feed unit 3 for feeding paper, and a paper discharge unit 4 for transporting the print paper 5 discharged from the six-stage print unit 2 and placing the print paper 5 on a paper discharge table 6 in a stacked state.

The six printing units 2 are arranged in multiple stages in the vertical direction, and each printing unit 2 is configured to be able to execute a printing operation independently and independently. Each printing unit 2 includes an inkjet head 7 and a pair of upper and lower upstream transport rolls 8 arranged on the upstream side of transport of the inkjet head 7.
a, 8b, and a pair of upper and lower downstream transport rolls 9a, 9b disposed on the downstream side of the inkjet head 7 in the transport direction. The ink jet type head 7 is disposed at an upper position separated from the printing paper 5 by a certain distance. The printing paper 5 sandwiched between the pair of upstream transport rolls 8a and 8b and between the pair of downstream transport rolls 9a and 9b is rotated at a predetermined print transport speed by the rotation of the rolls 8a, 8b, 9a and 9b. The ink jet head 7 jets ink onto the conveyed printing paper 5 to perform printing on the printing paper 5. The ink jet head 7 is of a type that ejects ink using, for example, a piezoelectric element (piezo element).

The paper supply unit 3 is pressed against a paper supply table 11 on which the stacked print papers 5 are placed and the print paper 5 at the uppermost position placed on the paper supply table 11, A pair of paper feed rolls 12 and 13 for feeding only the print paper 5 at the position, and a guide plate 14 for changing the direction of the print paper 5 transported by the pair of paper feed rolls 12 and 13 in the vertical direction.
And a vertical paper transport mechanism 15 for transporting the printing paper 5 guided by the guide plate 14 upward, and a plurality of direction changes for guiding the printing paper 5 transported by the vertical paper transport mechanism 15 to each printing unit 2. The paper feed unit 3 having a claw 16
The printing paper 5 fed from the printing unit 5 is guided between the pair of upstream transport rolls 8a and 8b of the printing unit 2 at the corresponding stage.

The paper vertical transport mechanism 15 includes a pair of pulleys 1.
Endless belt 18 stretched between 7a and 17b
And a suction means (not shown) for sucking the belt 18 toward the paper transport path.
The belt 18 of No. 5 is moved in the direction of arrow A in FIG.

The paper discharge unit 4 is installed vertically on the paper discharge side of the plurality of printing units 2, and a paper vertical transport mechanism 20 that transports the printing paper 5 discharged from each printing unit 2 right below, A guide plate 21 disposed below the paper vertical transport mechanism 20 for changing the direction of the printing paper 5 in the horizontal direction, and a paper horizontal installed in a substantially horizontal direction for transporting the printing paper 5 whose direction has been changed by the guide plate 21 The printing apparatus includes a transport mechanism 22 and a paper discharge tray 6 disposed at a position where the printing paper 5 falls on the downstream side of the paper horizontal transport mechanism 22. Each of the paper vertical transport mechanism 20 and the paper horizontal transport mechanism 22 includes endless belts 27 and 28 stretched between a pair of pulleys 25a, 25b, 26a and 26b, and the belt 2
And suction means (not shown) for sucking the sheet conveyance path 7 and 28. The belts 27 and 28 of the paper vertical transport mechanism 20 and the paper horizontal transport mechanism 22 are moved in the directions of arrows B and C in FIG.

Next, the waste ink processing device 30 of the multi-head printer 1 will be described. As shown in FIG. 1, head cleaning units 31 are provided in the vicinity of the six-stage ink jet heads 7, respectively. Each of the head cleaning units 31 performs a suction recovery operation of recovering ink ejected by the corresponding inkjet head 7 by its own ejection force or sucking the corresponding inkjet head 7 to eject ink. The collected ink is collected, and a cleaning process such as wiping the ejection port of the corresponding inkjet head 7 is performed.

Each head cleaning unit 31 is connected to a single suction pump 33 via each ink transport tube 32, and is suctioned at a constant pressure so that the suction force of each head cleaning unit 311 by the suction pump 33 becomes equal. Means 34 are provided. The equal-pressure suction means 34 has the same diameter as the ink transport tubes 32 and has the same length from each head cleaning unit 31 to the suction pump 33 so that they have the same diameter. It is configured to suck. Specifically, the ink transport tubes 3 from each head cleaning unit 31 to the suction pump 33
2 are connected to each other like a drawing line of a so-called tournament system so as to have the same length.

The suction pump 33 has an ink transport tube 3
5, a single waste ink tank 36 is connected. The waste ink tank 36 is detachable from the printing apparatus main body 37 and is formed in a bottle shape. The waste ink tank 36 is preferably arranged at a position where the user can easily replace it.

The waste ink tank 36 includes a bottle body 36a.
And a lid 36b for closing the opening thereof. The lid 36b is provided with a vent hole 38. Further, the waste ink tank 36 is provided with a full tank detection sensor 39 for detecting that the waste ink contained inside is full. The full tank detection sensor 39 is provided by an optical sensor in the first embodiment, but may be provided by a contact type sensor, and the type of the sensor does not matter as long as the full tank can be detected. The detection output of the full tank detection sensor 39 is output to a control unit (not shown). When the full tank detection sensor 39 detects the full tank, the control unit indicates that an ink absorber 40 described later in the waste ink tank 36 is to be replaced. And take measures to make the user aware.

The bottle body 36 of the waste ink tank 36
The ink absorber 40 is accommodated in a. The ink absorber 40 is made of a high-molecular polymer that expands in volume according to the amount of ink absorbed when the ink is absorbed.
Examples of the high-molecular polymer include a cross-linked polyacrylic acid partially neutralized product, a starch acrylonitrilo copolymer, a starch acrylic acid graft copolymer, a hydrolyzate of a vinyl acetate-acrylate copolymer, and a cationic monomer cross-linked polymer. There is coalescence.

In the above configuration, the printing paper 5 on the paper feeding table 11 is sequentially conveyed by the pair of paper feeding rolls 12 and 13, and the conveyed printing paper 5 is changed in the vertical direction through the guide plate 14. It contacts the lower end position of the belt 18 of the paper vertical transport mechanism 15. Then, the printing paper 5 is moved in the vertical direction together with the belt 18 while being sucked by the belt 18, the horizontal transport direction is selectively changed by the plurality of direction changing claws 16, and the printing paper 5 is sequentially fed to the desired printing unit 2.
The printing paper 5 on which the printing process has been performed by the plurality of printing units 2 is discharged in a horizontal state toward the paper vertical transport mechanism 20, and the leading end of the discharged printing paper 5 is a belt of the paper vertical transport mechanism 20. When it comes into contact with the belt 27, it is moved downward together with the belt 27 while being sucked by the belt 27. And
When the printing paper 5 is conveyed to the lowermost position of the belt 27, the leading end of the printing paper 5 is changed in direction by the guide plate 21 and comes into contact with the belt 28 of the paper horizontal conveyance mechanism 22.
Then, the printing paper 5 is transferred to the belt 2 of the paper horizontal transport mechanism 22.
While being sucked by the belt 8, it is moved substantially horizontally with the belt 28. Then, when the printing paper 5 reaches the lowermost stream of the belt 28, the printing paper 5 is dropped onto the paper discharge table 6 from here, and is placed on the paper discharge table 6.

Next, a description will be given of a head cleaning operation performed immediately before the above-described printing operation or periodically. Each of the head cleaning units 31 is disposed at a suction position of each of the ink-jet heads 7, and a suction pump 33 is provided.
Drive. Then, each head cleaning unit 31 sucks the ink of the ink jet head 7 by the suction force, and the ink is discharged to each head cleaning unit 31. Here, since each head cleaning unit 31 sucks each ink jet head 7 at an equal pressure, each ink jet head 7 is sucked with an appropriate suction force. Then, the waste ink discharged to each head cleaning unit 31 flows into the single suction pump 33 through the ink transport tube 32, and then is stored in the waste ink tank 36 through the ink transport tube 35. The waste ink stored in the waste ink tank 36 is absorbed by the polymer, and the polymer expands in volume according to the amount of the absorbed ink.

In this waste ink processing apparatus 30, ink can be suctioned from all the ink jet heads 7 with equal pressure from each head cleaning unit 31 by a smaller number (one) of suction pumps 33 than the number of ink jet heads 7. Therefore, appropriate cleaning can be performed on each ink jet head 7 with a small number of suction pumps 33.
In the first embodiment, since the number of the suction pumps 33 is one, the minimum number of the suction pumps 33 is sufficient, and the cost, space, and maintenance are further reduced.

In the first embodiment, the equal-pressure suction means 34 is provided with the suction pump 3 from each head cleaning section 31.
Since the ink transport tubes 32 up to 3 have the same diameter and the same length, they are configured to be suctioned at the same pressure, so that the ink suction force of each head cleaning unit 31 is made equal. , Only the ink transport tube 32 is used, and the suction pump 33
Since the ink transport tube 32 having the same diameter can be used, it can be realized at very low cost. or,
By connecting the ink transport tubes 32 from each head cleaning unit 31 to the suction pump 33 as shown in a drawing line of a so-called tournament system, they have the same length. , Each head cleaning unit 31
To the suction pump 33 may be connected by one ink transport tube 32 of the same length.

In the first embodiment, since the number of the waste ink tanks 36 is one, the minimum number of the waste ink tanks 36 is sufficient, and the cost, space, and maintenance are further reduced. Further, the disposal of the waste ink stored in the waste ink tank 36 is facilitated.

In the first embodiment, the waste ink tank 36 is detachable from the printer main body 37 and has a bottle shape. Therefore, when the waste ink is full, the waste ink tank 36 is removed from the printer. Since it is possible to dispose of the waste ink inside by removing from the main body 37, the disposal work of the waste ink is easy.

In the first embodiment, the waste ink tank 36 is provided with the full tank detection sensor 39 for detecting that the contained waste ink is full. Since it is possible to easily recognize when the ink is discarded, it is possible to prevent a situation where the user forgets to discard the ink. In addition, since the full ink detection sensor 39 detects that the waste ink in the waste ink tank 36 is full, the suction recovery operation is counted more accurately than the means for predicting the fullness by counting the suction recovery operation. There is also an advantage that the full tank can be reliably detected.

In the first embodiment, since the ink absorber 40 is accommodated in the waste ink tank 36, even when the waste ink tank 36 is inclined due to the inclination of the printing apparatus main body 37, the waste ink inside the waste ink tank 36 is stored. Is not easily leaked to the outside, so that it is possible to prevent the floor and the like from being stained with waste ink as much as possible.

In the first embodiment, the lid 36b of the waste ink tank 36 is provided with the ventilation hole 38, so that the water content of the aqueous ink evaporates therefrom. The ventilation hole 38 may be perforated as in the first embodiment, or may be a mesh.

In the first embodiment, six stages (multi stages) are used.
The cleaning process is performed on all the ink jet heads 7 of the printing unit 2 at the same time. However, as in the modification shown in FIG. 2, valves 32 a are provided between the head cleaning units 31 and the suction pump 33. By opening only the valve 32a corresponding to the printing unit 2 to be used under the control of the control unit A, the inkjet head 7 to be used is
The ink can be suctioned from the head cleaning unit 31 at a constant pressure. In this case, the pump pressure of the suction pump 33 is controlled by the control unit A according to the number of printing units 2 to be used, that is, the number of valves 32a to be opened for performing the cleaning process.

FIG. 3 shows a second embodiment of the present invention, in which a multi-head printer 1 'having a waste ink processing device 41 mounted thereon.
FIG. Comparing the second embodiment and the first embodiment, only the structure of the constant pressure suction means 42 of the waste ink processing device 41 is different, and the other structures are the same. Are denoted by the same reference numerals, and the description thereof will be omitted. Only the configuration of the different equal pressure suction means 42 will be described.

As shown in FIG. 3, the equal pressure suction means 42
By changing the diameter of each of the ink transport tubes 43a to 43c according to the length of each of the ink transport tubes 43a to 43c from each head cleaning unit 31 to the suction pump 33, suction is performed at an equal pressure. The tube diameter of the ink transport tubes 43a to 43c is set thicker as the tube length is longer 43a and thinner as the tube length 43c is shorter, and is determined in detail as follows.
That is, the pump pressure required for suction may be considered as the resistance when the ink (liquid) flows through the ink transport tubes (tubes) 43a to 43c, and the resistance of the straight pipe becomes equal according to the Darcy equation described later. The tube diameter as described above.

[0049]

(Equation 1) In the second embodiment, almost the same operation as in the first embodiment is performed.
The effect is obtained.

Further, the equal pressure suction means 42 of the second embodiment is
Since the diameter of each of the ink transport tubes 43a to 43c from the head cleaning unit 31 to the suction pump 33 is varied according to the length of each of the ink transport tubes 43a to 43c, suction is performed at an equal pressure. Only the ink transport tubes 43a to 43c are used to equalize the ink suction force of the cleaning unit 31 and the length of the ink transport tubes 43a to 43c from each head cleaning unit 31 to the suction pump 33 is set to the shortest. Therefore, the cost can be reduced and the tube wiring can be realized with a simple configuration.

In the first and second embodiments, only one suction pump 33 is provided. However, only one suction pump 33 can provide an appropriate suction force due to an increase in the number of ink jet heads 7 and the like. If the number of suction pumps 33 cannot be secured, a smaller number (one or more) of suction pumps 33 than the number of inkjet heads 7 may be provided.

In the first and second embodiments, only one waste ink tank 36 is provided, but two or more waste ink tanks 36 may be provided.

According to each of the above-described embodiments, the high molecular polymer that expands in volume when absorbing waste ink is used as the ink absorber 40. An absorbent that does not change may be used. Even when a sponge or the like is used in this manner, the waste ink tank 3
Even when 6 is inclined, it is possible to prevent a situation in which waste ink inside easily leaks to the outside.

In each of the above-described embodiments, the waste ink tank 36 is detachably mounted on the printing apparatus main body 37. Therefore, by removing the waste ink tank 36, the waste ink can be discarded. Is fixed to the printer main body 37, and the ink absorber 4 in the waste ink tank 36 is fixed.
It may be configured that the waste ink is discarded by replacing 0.

In the above embodiments, the user is informed that the waste ink in the waste ink tank 36 is full by displaying it on a display panel (not shown). May be notified, for example, by voice.

In each of the above embodiments, the printing unit 2 has six stages. However, the present invention can be applied to a plurality of printing units (two or more stages) other than the above.

According to each of the above embodiments, each printing unit 2
The single inkjet printing head 7 is used to perform single-color printing.
Of course, the present invention can similarly be applied to a case where a plurality of multi-color printing can be performed.

[0058]

As described above, according to the first aspect of the present invention, ink can be suctioned from all head cleaning units at the same pressure with respect to all ink jet heads by using a suction pump smaller in number than the number of ink jet heads. It is possible to perform proper cleaning for each ink jet head with a small number of suction pumps.

According to the second aspect of the present invention, only the ink transport tubes are used to equalize the ink suction force of each head cleaning unit and the ink transport tubes from each head cleaning unit to the suction pump are the same. Because it is possible to use those having the same diameter and the same length,
It can be realized at very low cost.

According to the third aspect of the present invention, only the ink transport tube is used to equalize the ink suction force of each head cleaning section and the ink transport tube from each head cleaning section to the suction pump is provided. Since the length can be set to the shortest, the cost can be reduced and the tube wiring can be realized with a simple configuration.

According to the fourth aspect of the present invention, since the number of suction pumps smaller than the number of head cleaning units is one, the minimum number of suction pumps is sufficient, further reducing cost, space and maintenance. become.

According to the fifth aspect of the present invention, since the number of waste ink tanks is one, the minimum number of waste ink tanks is sufficient.
Furthermore, cost reduction, space saving, and maintenance saving are achieved, and the disposal of waste ink stored in the waste ink tank is facilitated.

According to the sixth aspect of the present invention, when the waste ink is full, the waste ink tank can be removed from the printing apparatus main body and the waste ink inside can be disposed of, so that the waste ink disposal operation can be easily performed. Become.

According to the seventh aspect of the invention, it is possible to easily recognize when the ink in the waste ink tank is discarded.
It is possible to prevent a situation where the user forgets to discard the ink.

According to the eighth aspect of the invention, even when the waste ink tank is inclined due to the inclination of the printing apparatus main body or the like, the waste ink inside does not easily leak to the outside, so that the floor and the like are stained with the waste ink. Can be prevented as much as possible.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of the present invention and is a schematic configuration diagram of a multi-head printer equipped with a waste ink processing device.

FIG. 2 is a schematic configuration diagram showing a modification of the first embodiment.

FIG. 3 is a schematic diagram illustrating a multi-head printer equipped with a waste ink processing device according to a second embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of a waste ink processing apparatus of a multi-head printer that can be easily considered from the related art.

FIG. 5 is a schematic configuration diagram of a waste ink processing device of a multi-head printer that can be easily considered from the related art.

[Explanation of symbols]

 1, 1 'multi-head printer 2 printing unit 3 paper feeding unit 4 paper discharging unit 5 printing paper (printing medium) 7 ink jet head 30 waste ink treatment device 31 head cleaning unit 32 ink transport tube 33 suction pump 34 constant pressure suction means 35 ink transport tube 36 waste ink tank 37 printer main body 38 vent hole 39 full tank detection sensor 40 ink absorber 41 constant pressure suction means 43a to 43c ink transport tube

Claims (8)

[Claims] 1. A multi-head printer having a plurality of printing units for performing printing on a print medium using an ink-jet type head, wherein a plurality of head cleaning units for suctioning ink to each of the ink-jet type heads to make a discharge state appropriate. Department and
A plurality of suction pumps connected to the plurality of head cleaning units via an ink transport tube, the number of suction pumps being smaller than the number of the head cleaning units, and a waste ink tank storing waste ink sucked by the suction pumps; A waste ink processing apparatus for a multi-head printer, wherein a pump is provided with a constant pressure suction means for suctioning waste ink from each of the head cleaning units at a constant pressure. 2. A waste ink processing apparatus for a multi-head printer according to claim 1, wherein said equal-pressure suction means has the same diameter as said ink transport tube from each of said head cleaning units to said suction pump, and And a suction unit for suctioning at an equal pressure by making the lengths substantially the same. 3. The waste ink processing apparatus for a multi-head printer according to claim 1, wherein said constant-pressure suction means corresponds to a length of each of said ink transport tubes from each of said head cleaning units to said suction pump. A waste ink treatment apparatus for a multi-head printer, wherein suction is performed at an equal pressure by changing the diameter of each ink transport tube. 4. The multi-head printer waste ink processing apparatus according to claim 1, wherein the number of suction pumps smaller than the number of head cleaning units is one. Waste ink treatment device for head printer. 5. The waste ink processing device for a multi-head printer according to claim 1, wherein the waste ink tank is one. 6. The multi-head printer according to claim 1, wherein the waste ink tank is detachable from a printing apparatus main body and has a bottle shape. Waste ink treatment equipment. 7. The waste ink processing device for a multi-head printer according to claim 1, further comprising: a full tank detection sensor that detects that the waste ink stored in the waste ink tank is full. A waste ink processing device for a multi-head printer. 8. The waste ink processing device for a multi-head printer according to claim 1, wherein an ink absorber is accommodated in the waste ink tank.