JP2002273913A - Ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet printer capable of preventing a wasteful ink suction from occurring at the time of maintenance services extended to an ink head, without increasing the number of ink sucking pumps. SOLUTION: The inner space of a cap 21 airtightly attached to an ink head unit 12 during using of no printer, is partitioned into a suction space 21a for a color ink and a suction space 21b for a black ink and the inks of these spaces 21a and 21b are discretely sucked. A tube pump 22 maintains an oppression roller which oppresses a color ink tube 24 and an oppression roller which oppresses a black ink tube 25 respectively in such a manner that the oppression rollers freely move between a tube oppression position and a non-tube oppression position. These rollers are selectively transferred to the tube oppression position and the non-tube oppression position by the shift of the oppression rollers in a rotor rotating direction following the rotation of the rotor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer, and more particularly, to an ink jet printer having a function of performing maintenance of an ink head by sucking ink remaining in an ink discharge nozzle of an ink head. .

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 21, ink heads 81c, 81m, 81y and 8 of four colors C (cyan), M (magenta), Y (yellow) and K (black) are used.
A guide shaft 84 extending in the main scanning direction with an ink cartridge 83 having an ink head unit 81 made of 1k and an ink tank 82 containing inks of four colors.
While moving along each of the ink heads 81c, 81c.
A color image is printed on a recording sheet by selectively ejecting inks of different colors from m, 81y, and 81k and attaching the ink to a recording sheet conveyed in a sub-scanning direction (a direction orthogonal to the main scanning direction). A known color inkjet printer is known.

When this type of color ink jet printer is not used (during non-recording operation), the ink head unit 81 of the ink cartridge 83 is sealed to protect the ink heads 81c, 81m, 81y and 81k, In order to prevent clogging of the ink ejection nozzle due to drying of the ink, contact with the atmosphere is blocked by the cap 85. That is, when not in use, the ink cartridge 83 is located at the home position at one end of the movable range thereof, and the cap 85 facing the ink head unit 81 at this home position is moved from the retracted position (the position shown). The cap 85 comes into close contact with the ink head unit 81 by moving to the contact position. Therefore, the cap 85 is configured to be movable in the direction of arrow A in the figure.

Further, ink heads 81c, 81m, 81
When the performance of the ink discharge nozzles of y and 81k is clogged or bubbles are mixed in the ink discharge nozzles and the performance is reduced, a tube pump (suction pump) 86 connected to the cap 85 To recover the performance by sucking out the ink in the ink discharge nozzle. Cap 85 is C,
All ink heads 81c, 81m, 81 of M, Y, K
The ink suction force acts on y and 81k at the same time. The ink sucked by the tube pump 86 is collected in the waste ink unit 87.

FIGS. 22A and 22B show the structure of a tube pump 86 in a conventional ink jet printer. The tube pump 86 is provided with a roller holder (rotor) 92 which is rotatably supported by a plurality of tube pressing rollers 91.
Is housed in a substantially cylindrical guide wall 93 forming a part of the pump case 94. The roller holder 92 is rotationally driven in the direction of arrow A in the figure by a motor 95 disposed above the roller holder 92. Tube compression roller 91 and guide wall 9
The ink suction tube 96 is provided between the guide wall 9 and the ink suction tube 96.
3 are arranged along the circumferential direction.

[0006] The tube pump 86 is provided between the tube pressing roller 91 and the guide wall 93.
The ink suction tube 9 is rotated by rotating the roller holder 92 in the direction of the arrow A while pressing (pressing) the ink suction tube 9.
A negative pressure is generated on the suction side 6 to suck ink, and the sucked ink is sent to the discharge side.

[0007]

In a color ink jet printer, a dye ink is generally used for C, M, and Y color inks, and a pigment ink is generally used for black (K) ink. Since black ink, which is an ink, has higher viscosity, it takes a lot of time to suck ink.

However, in the above conventional configuration, C,
All ink heads 81c, 81m, 81 of M, Y, K
Since the ink suction is performed simultaneously for y and 81k, if the required ink suction time is set for the black ink, more ink than necessary for the color ink is sucked and discarded. Problem.

In order to eliminate such a problem,
It is conceivable to separate the maintenance mechanism by ink suction for color ink and black ink, but in this case, multiple pumps for sucking ink are required,
There is a problem that the size of the device is increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is possible to separately suction color ink and black ink without increasing the number of ink suction pumps. Accordingly, an object of the present invention is to provide an ink jet printer capable of preventing useless ink suction during maintenance of an ink head.

[0011]

The present invention has the following configuration to achieve the above object. A first gist of the present invention is to selectively eject ink of different colors from each ink ejection head of the ink head unit while moving an ink head unit having a plurality of ink ejection heads along a recording sheet. In an ink jet printer that prints at least a color image on the recording paper by attaching to the recording paper, a cap that detachably adheres to the ink head unit so as to cover the ink ejection head of the ink head unit, A suction pump for sucking ink from the ink ejection head in a state where the cap is in close contact with the ink head unit, wherein the cap has a suction space for each of color ink and black ink; In the suction space, for each suction drawn out from the suction part of the suction pump Cube is provided, the suction operation of the one-direction color ink tube by the rotation of the suction pump, by rotation in the opposite direction in the ink jet printer so as to implement the suction operation of the black ink tube.

According to the first aspect of the present invention, the internal space of the cap that is in close contact with the ink head unit when the printer is not in use is divided into a color ink suction space and a black ink suction space. For each suction space, each separate suction tube drawn out from the suction part of the suction pump is connected, and the suction operation by the suction tube connected to the color ink suction space and the black ink suction space are performed. Since the suction operation by the connected suction tube is performed separately, the color ink and the black ink can be separately suctioned without increasing the number of pumps for sucking the ink. It is possible to prevent unnecessary ink suction during head maintenance.

A second gist of the present invention is that the suction pump is provided between a rotor which rotates while holding a tube pressing means on an outer peripheral portion and a substantially cylindrical guide wall surrounding the rotor.
The suction tube for the color ink is inserted,
The invention is characterized in that a drive source for rotating the rotor in forward and reverse directions is provided to press the color ink and black ink tubes between the tube pressing means and the guide wall. In the ink jet printer.

According to a second aspect of the present invention, the color ink and the black ink tube are pressed between the tube pressing means and the guide wall by rotating the rotor, so that suction is performed with a simple structure. Operation can be realized.

According to a third aspect of the present invention, the compression means includes:
A color compression roller that presses against the color ink tube, and a black compression roller that presses against the black ink tube, wherein the color compression roller is attached to the rotor by rotating one of the rotors A compression position for pressing the color ink tube and a non-compression position where no compression is performed by rotation in the opposite direction are provided so as to be movable, and the black compression roller is attached to the rotor by rotating one of the rotors. The inkjet printer according to the second aspect, wherein the inkjet printer is provided so as to be movable between a non-compression position in which the black ink tube is not compressed and a compression position in which the black ink tube is compressed by rotation in the reverse direction.

According to a third aspect of the present invention, a color pressure roller for pressing a color suction tube and a black pressure roller for pressing a black suction tube are pressed against a suction tube. The rotor is movably held between the compression position and the non-compression position where no compression is performed, and with the rotation of the rotor, the color compression roller and the black compression roller are displaced in a substantially rotational direction of the rotor, Suction pump is realized with a simple configuration by selectively moving one compression roller to the compression position so that the suction operation by the color suction tube and the black suction tube can be performed separately. it can.

According to a fourth aspect of the present invention, in the rotor, a first holder for holding the color compression roller and a second holder for holding the black compression roller are arranged side by side in the direction of the rotor rotation axis. A bearing portion is formed in each of the holder portions to support the compression roller so as to be movable between the compression position and the non-compression position.
In the ink jet printer.

According to the fourth aspect of the present invention, the first holder portion and the second holder portion are arranged on the rotor in the axial direction of the rotor, and each bearing portion is provided. And the movement between the non-compression position can be easily realized.

According to a fifth aspect of the present invention, a driving source for applying a rotational driving force to the rotor can be driven to rotate forward and backward, and the bearing portion is formed substantially along the rotational direction of the rotor. Is a groove or a hole that is displaced in the radial direction of the rotor more than the other roller support portion, and a roller support portion radially outside the bearing portion forms the compression position, and the diameter of the bearing portion is The roller support portion on the inner side in the direction forms the non-compression position, and the first bearing portion of the first holder portion and the second bearing portion of the second holder portion define the non-compression position and the non-compression position in the rotor rotation direction. The ink jet printer according to the fourth aspect, wherein the positional relationship is formed in reverse.

According to a fifth aspect of the present invention, in the first bearing portion of the first holder portion and the second bearing portion of the second holder portion, the compression position and the non-compression position in the rotor rotation direction are provided. Is simply formed by changing the rotation direction of the rotor, one of the color compression roller and the black compression roller is selectively placed in the compression position, and the other is not compressed. Position. Therefore, by switching the direction of the rotation drive between forward and reverse,
The suction of the black ink and the suction of the color ink can be performed separately, and the suction pump can be realized with a simpler configuration.

According to a sixth aspect of the present invention, at least one of the suction tube for the black ink and the suction tube for the color ink is connected to a path from the cap to the waste ink storage section when the printer is not used. The ink jet printer according to any one of the first to fifth aspects, further comprising a tube pressing mechanism that closes by pressing during the process.

According to the sixth aspect of the present invention, at least one of the suction tube for black ink and the suction tube for color ink is connected to the path from the cap to the waste ink storage section when the printer is not used. By having a tube pressing mechanism that closes by pressing in the middle of the process, the space inside the cap is shut off from the outside air, and drying of the ink remaining at the ink discharge nozzles of the ink head can be prevented.

According to a seventh aspect of the present invention, a driving source for applying a rotational driving force to the rotor can be driven to rotate forward and backward, and one of the first holder and the second holder is driven by the drive. A driving-side holder that receives a rotational driving force from a source; and a driven-side holder that receives a driving force from the driving-side holder via a driving transmission mechanism, wherein the driving transmission mechanism moves from the driving-side holder to the driven-side holder. First transmitting the forward rotation driving force
, A second state in which the reverse drive force is transmitted from the drive-side holder to the driven-side holder, and a third state in which only the drive-side holder is driven to rotate forward or reverse, and the suction operation is completed. The ink jet printer according to the gist of the present invention is characterized in that the compression rollers of the subsequent first holder portion and the second holder portion are released from the compression position.

According to the seventh aspect of the present invention, the suction of the color ink and the black ink can be separately performed by one motor (drive source), and the inks having different times required for the ink suction can be appropriately separated. The suction can be performed in the suction time, so that unnecessary ink suction during maintenance of the ink head can be prevented, and the size of the apparatus can be avoided without increasing the number of pumps. Further, after the suction is completed, the pressing state of the pressing roller of the driving-side holder can be released by the third state of the driving force transmission mechanism while the non-pressing state of the pressing roller of the driven-side holder is maintained. Thus, in the tube pump that enables suction to only one of the tubes by switching the rotation direction of the rotor, the pressed state of all the compression rollers can be simultaneously released. When the pressure rises, the ink leaks from between the head and the cap, so that backflow to the ink head side can be prevented, and deformation of the tube due to long-term pressure on a certain portion of the tube can be prevented.

According to an eighth aspect of the present invention, the bearing portion comprises:
A roller support portion formed substantially along the rotor rotation direction, wherein one of the roller support portions is a groove or a hole that is displaced in the radial direction of the rotor more than the other roller support portion, and is a roller support portion radially outside the bearing portion. Forms the compression position, a roller support portion radially inward of the bearing portion forms the non-compression position, and a first bearing portion of the first holder portion and the second bearing portion.
The ink jet printer according to the seventh aspect, wherein in the second bearing portion of the holder portion, the positional relationship between the compression position and the non-compression position in the rotation direction of the rotor is reversed.

According to an eighth aspect of the present invention, the positional relationship between the compressed position and the non-compressed position in the rotor rotation direction of the first bearing portion and the second bearing portion is reversed (subject to the radial direction of the rotor). Forming the first holder portion and the second holder portion.
The compression roller of the holder can be moved between the compression position and the non-compression position at a small angle.

A ninth aspect of the present invention resides in that the driving force transmission mechanism is formed on a concentric circle centered on a rotation axis on the opposing surfaces of the driving side holder and the driven side holder. The first or second contact member is configured when the first contact member contacts the second contact member from the upstream side in the forward or reverse rotation direction. An ink jet printer according to the seventh aspect, wherein the printer takes a state, and takes a third state when the first and second contact members are not in a contact state. With such a configuration, the driving force transmission mechanism is realized with a simple configuration.

A tenth aspect of the present invention is characterized in that the first contact member and the second contact member require approximately one rotation to switch from the first state to the second state. An ink jet printer according to the ninth aspect. With such a configuration, a margin in the third state can be widened.

An eleventh aspect of the present invention is characterized in that at least one of the first contact member and the second contact member has a contact interval with the other contact member of less than one rotation. The ink jet printer described in the summary 9 above. With such a configuration, the switching from the first state to the second state can be quickly performed.

According to a twelfth aspect of the present invention, when performing suction processing of both color ink and black ink, the suction operation of the ink corresponding to the driven side holder is performed first. In the described ink jet printer. With this configuration, the pressure release process after the end of the suction process is simplified.

According to a thirteenth aspect of the present invention, the bearing is characterized in that the bearing has a curved portion between the compression position and the non-compression position, which is radially outward from the compression position. In the described ink jet printer.

According to a thirteenth aspect of the present invention, by having a curved portion radially outward from the compression position, the compression roller at the compression position is not compressed by the elasticity of the suction tube when the roller is pressed. It can be prevented from being returned to the position.

According to a fourteenth aspect of the present invention, the bearing portion is a groove or a hole for movably supporting a support shaft of a compression roller between the compression position and the non-compression position. The ink jet printer according to the fourth aspect, further comprising an elastic portion that applies a predetermined elastic force to a support shaft of the compression roller when the compression roller is moved to the non-compression position.

According to the fourteenth aspect of the present invention, a predetermined elastic force is applied to the support shaft of the compression roller when the elastic portion moves from the compression position to the non-compression position. It is possible to prevent a certain compression roller from being returned to the non-compression position due to the elasticity of the suction tube.

According to a fifteenth aspect of the present invention, the elastic portion includes:
The gist (14) is characterized in that the gist (14) has a pressing side having a narrower groove or hole of the bearing portion than the supporting shaft of the compression roller, and a supporting portion for swingably supporting the pressing side. In inkjet printers. With such a configuration, the elastic portion can be easily configured.

A sixteenth aspect of the present invention is that the color compression roller and the black compression roller are provided with a tube and a projection for pressing at least two places in the circumferential direction of the roller at each compression position. An ink jet printer according to a third aspect of the invention.

According to a sixteenth aspect of the present invention, at the pressing position, at least two rollers arranged in the circumferential direction of the roller are provided.
Since the projection at the location presses the roller, it is stable in the circumferential direction of the roller, and can be prevented from returning to the non-compression position due to the elasticity of the suction tube.

According to a seventeenth aspect of the present invention, a plurality of compression rollers are held in the first holder portion and the second holder portion, respectively, and two or more compression rollers are simultaneously mounted on one suction tube. An ink jet printer according to the second aspect, characterized in that the ink jet printer is pressed.

According to a seventeenth aspect of the present invention, a plurality of compression rollers are respectively held by the first holder portion and the second holder portion, and two or more compression rollers are simultaneously pressed against one suction tube. With this configuration, the ink in the suction tube is moved to the discharge side in a state where the ink is sealed between the two rollers, and the suction force can be reliably generated.

An eighteenth aspect of the present invention resides in that the first holder and the second holder each hold three or more compression rollers, and are equally spaced in the rotation direction of the first holder and the second holder. The inkjet printer according to the fifth aspect, wherein the ink jet printer is disposed.

According to an eighteenth aspect of the present invention, three compression rollers are held by the first holder portion and the second holder portion,
Since these are held at equal intervals in the rotation direction of the rotor, ink suction can be performed most efficiently with a small number of components.

A nineteenth aspect of the present invention is characterized in that the suction time for black ink is made longer than the suction time for color ink, or the suction force for black ink is made stronger than the suction force for color ink. An ink jet printer according to the first aspect of the invention.

According to the nineteenth aspect of the present invention, the suction time of black ink is made longer than the suction time of color ink, or the suction force of black ink is made stronger than the suction force of color ink. Thus, the maintenance of the ink head can be performed while minimizing the amount of wasted ink.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an external perspective view of an ink jet printer to which the present invention is applied, and FIG.
FIG. 2 is a schematic configuration diagram of a printing mechanism of the inkjet printer shown in FIG.

An ink jet printer (hereinafter, also simply referred to as a printer) 1 according to this embodiment includes a supply tray 2.
And a paper discharge tray 3 on the same side (front side) of the printer main body 1a. The recording paper P is placed on the paper feed tray 2 with one or a plurality of papers stacked with the recording surface side down, and when a printing request is given to the printer 1 from a higher-level device such as a personal computer. The pickup roller 4 operates to feed the recording paper P into the printer main body 1a one by one.

In the printer main body 1a, there is provided a paper feeding mechanism 8 comprising a large-diameter paper feed roller 6 and a plurality of small-diameter pressure contact rollers 7a to 7c provided in pressure contact with the peripheral surface thereof. The recording paper P fed by the pickup roller 4 is guided upward through the rear part of the printer main body 1a by the paper feed roller 6 of the paper feed mechanism 8 and the pressing rollers 7a to 7c, and is turned to the front side. To the printing unit 9.

The printing unit 9 includes an ink cartridge 10 held by an ink carriage (not shown), a guide shaft 11 for guiding the ink carriage in the main scanning direction (a direction perpendicular to the paper surface), and reciprocating the ink carriage in the main scanning direction. And a drive belt (not shown) for movement. The ink cartridge 10 includes an ink head unit 12 including four color ink heads 12c, 12m, 12y, and 12k of C, M, Y, and K, and an ink tank 13 containing four color inks. The ink cartridge 10 is held with the ink head unit 12 facing downward.

Below the ink cartridge 10, that is, at a position facing the ink head unit 12, a platen 14 is provided along the moving direction of the ink carriage, that is, the main scanning direction. The recording paper P fed from the paper feed tray 2 is sent onto the platen 14 by the paper feeding mechanism 8.

When the recording paper P is sent onto the platen 14, the ink carriage is moved along the guide shaft 11, and the ink heads 12c and 12m of the ink cartridge 10 are moved according to the image information requested to be printed. ,
A recording operation is performed in which inks of different colors are selectively ejected from 12y and 12k and adhere to the recording paper P. While the recording operation by the ink ejection is being performed, the conveyance of the recording paper P is stopped, and each time the recording operation for one line is completed, the ink heads 12c, 12m, 12y, 12
The recording paper P corresponding to the plurality of ink ejection nozzles of k is fed (conveyed in the sub-scanning direction). By repeating the printing operation and the feeding operation for one line in this manner, an image corresponding to the image information requested to be printed is recorded on the recording paper P. Recording paper P on which an image is recorded
Is dried by the drying device 15 and then discharged by the discharge rollers 16.
And is discharged onto the paper discharge tray 3 to be provided to the user.

While the above-described recording operation by ink ejection is repeated, impurities such as dust are mixed into the ink heads 12c, 12m, 12y, and 12k, the ink composition changes due to heat generation during ink ejection, and the ink ejection nozzles due to ink drying. Clogging, and air bubbles are mixed in the ink discharge nozzle. In order to remove such impurities and the like, a maintenance mechanism for cleaning the ink heads 12c, 12m, 12y, and 12k is arranged at a predetermined position (home position) outside the printing range.

FIG. 3 shows the printing unit 9 and the maintenance mechanism 20 in the ink jet printer 1 according to this embodiment.
The schematic configuration of is shown.

The maintenance mechanism 20 includes the ink head 1
A cap 21 that detachably adheres to the ink head unit 12 so as to collectively cover all the ink discharge nozzles 2c, 12m, 12y, and 12k, and a direction in which the cap 21 is attached to and detached from the ink head unit 12 (arrow A in the figure).
Direction) and a cap 21 that is in close contact with the ink head unit 12 by applying a suction force for sucking out the ink remaining in the ink ejection nozzles of the ink heads 12c, 12m, 12y, and 12k. It has a tube pump (suction pump) 23 for generating the ink in the internal space, and a waste ink unit 23 for collecting and storing the sucked ink.

When not in use (during non-printing operation), the maintenance mechanism 20 seals the ink head unit 12 of the ink cartridge 10 with the cap 21 to protect the ink heads 12c, 12m, 12y, and 12k.
Prevents clogging of ink ejection nozzles due to drying of ink. That is, when not in use, the ink cartridge 10
Is located at the home position at one end of the movable range, and at this home position, the cap 21 facing the ink head unit 12 is moved from the retracted position (the position shown) to the contact position.
The cap 21 comes into close contact with the ink head unit 12.

The ink heads 12c, 12m, 12
If the performance of the ink discharge nozzles of y and 12k deteriorates due to clogging of the ink discharge nozzles or mixing of bubbles into the ink discharge nozzles, a tube pump (suction pump) 22 connected to the cap 21 To recover the performance by sucking out the ink in the ink discharge nozzle.

The above configuration is almost the same as that of the conventional printer, but the printer 1 according to the present embodiment
1 is divided into a suction space 21a for color ink and a suction space 21b for black ink, and separate suction tubes 24 extending from the suction part of the tube pump 22 are provided for each of the suction spaces 21a and 21b. , 25 are connected to each other so that suction of color ink and suction of black ink can be performed separately. That is, the tube pump 22
Is a suction tube connected to the color ink suction space 21a (hereinafter, referred to as a color ink tube).
The suction operation by the suction tube 24 and the suction operation by the suction tube 25 (hereinafter, referred to as the black ink tube) 25 connected to the black ink suction space 21b can be performed separately.

FIG. 4 shows a configuration example of the tube pump 22 in this embodiment, FIG. 5 shows a configuration example of the tube pump 22 when sucking black ink, and FIG. 6 shows the configuration of the tube pump 22 when sucking color ink. 2 shows a configuration example. The tube pump 22 accommodates a rotor 27 that rotates in the horizontal direction while holding a plurality of tube compression rollers (tube compression means) 26 on an outer peripheral portion, in a substantially cylindrical guide wall 29 that forms a part of a pump case 28. Then, between the tube pressing roller 26 and the guide wall 29, the color ink tube 24 and the black ink tube 25 are vertically separated from each other and are arranged along the circumferential direction of the guide wall 29 (FIG. 7). In this example, the color ink tube 24 is disposed below the black ink tube 25.

The rotor 27 is provided with the color ink tube 2.
4 compression rollers 26C for pressing (pressing) 4
And the three black compression rollers 2 for pressing the black ink tube 25.
6B (see FIG. 4B). The two holder portions 27C and 27B are arranged in parallel with each other in the direction of the rotation axis of the rotor 27 (the vertical direction in FIG. 4B).

The color pressure roller 26C is held by the first holder portion 27C so as to be movable between a pressure position where the color ink tube 24 is pressed and a non-pressure position where the color ink tube 24 is not pressed. The black pressing roller 26B is held by the second holder 27B so as to be movable between a pressing position where the black ink tube 25 is pressed and a non-pressing position where the black ink tube 25 is not pressed.

The first holder portion 27C comprises a pair of upper and lower circular flange-shaped holding plates 31a and 31b integrally formed on the lower portion of the rotor shaft 27a. 2nd holder part 27B
Consists of a pair of upper and lower circular flange-shaped holding plates 32a and 32b integrally formed on the upper portion of the rotor shaft 27a.

The holding plates 31a, 31 of the first holder 27C
4B, there is a through hole serving as a guide part for enabling each color compression roller 26C to be movable between a compression position and a non-compression position, as shown in a chain line in FIG. Bearing portions 33C are formed at three places near the peripheral edge. Specifically, the bearing 33C is formed by a shaft 26A formed on a concentric shaft of each color compression roller 26C.
The color compression roller 26C moves between the compression position and the non-compression position by penetrating into, engaging with, and slidable into the 3C.

The holding plates 32a, 32 of the second holder 27B
4B, as shown by the solid line in FIG. 4A and FIG. 5, a through hole serving as a guide portion for movably supporting each color compression roller 26B between a compression position and a non-compression position. Bearing portions 33B formed of holes are formed at three places near the peripheral edge. Specifically, the shaft 33A formed on the concentric shaft of each color compression roller 26B penetrates into and engages with the bearing 33B, so that the color compression roller 26C is slidable. Move between a compression position and a non-compression position. Note that the bearing portions 33C and 33B may be any guide portion that allows the shaft 26A to slide freely, and may be configured by a guide groove.

The bearing 33C of the first holder 27C is
The end 34a formed along the substantially circumferential direction (substantially rotational direction) of the rotor 27 and serving as one roller support is closer to the outer periphery of the rotor 27 than the end 34b serving as the other roller support (rotational axis of the rotor). (In the radial direction with respect to the outer periphery in the radial direction), the compression roller 26 is supported when the color compression roller 26C is supported by the one end 34a.
C is located at the compression position, and when the other end 34b of the bearing portion 33C supports the color compression roller 26C, the roller 26C is formed at the non-compression position (FIG. 4, FIG. 4). 6).

The bearing 33B of the second holder 27B is also
One end 34a is formed along a substantially circumferential direction of the rotor 27, and one end 34a is a substantially arc-shaped hole located on the outer peripheral side of the rotor 27 with respect to the other end 34b.
When the black compression roller 26B is supported by the above, the compression roller 26B is positioned at the compression position, and when the black compression roller 26B is supported by the other end 34b of the bearing portion 33B, the roller 26B is disengaged. It is formed so as to be located at the compression position (FIGS. 4 and 5).

That is, the pressing rollers 26B and 26C
The compression position (34a) and the non-compression position (34b) are moved by the displacement of the rotor 27 in the substantially circumferential direction (substantially the rotation direction) and the displacement in the radial direction.

As shown in FIG. 4A, the bearing 33C of the first holder 27C and the bearing 33B of the second holder 27B are connected to each other at one end when viewed from the axial direction of the rotor 27. The portions 34a are overlapped with each other, and the other ends 34b are formed so as to have a line symmetrical positional relationship with the radius of the rotor 27. That is, the one end 34a and the other end 34b are arranged so that the positional relationship between the one end 34a and the other end 34b is reversed with respect to the rotation direction of the rotor 27.
When the rotor 27 is rotated forward, the black compression roller 26B
Moves to the compression position (34a) and the color compression roller 26C moves to the non-compression position (34b). When the rotor 27 is rotated in the reverse direction, the color compression roller 26C moves to the compression position and the black compression roller 26B moves. Are formed to move to the non-compression position.

The one ends 34a of the bearings 33C and 33B are arranged at regular intervals in the rotation direction of the rotor 27. Thus, when the rotor 27 is rotated forward, 3
The two black compression rollers 26B move to the compression position and rotate 120 ° in the rotational direction with respect to the rotation center of the rotor 27.
They are arranged at regular intervals. When the rotor 27 is rotated in the reverse direction, the three color compression rollers 26C move to the compression position and are arranged at equal intervals of 120 ° in the rotation direction with respect to the rotation center of the rotor 27.

Then, two of the three rollers moved to the pressing position move simultaneously with the rotation of the roller holder 27 while simultaneously pressing one of the suction tubes, so that the ink in the suction tube is removed by the two rollers. It is moved to the discharge side in a state where it is sealed between them to generate a suction force. Compression roller 26 held by each holder 27C, 27B
Although the number of C and 26B may be four or more,
As shown in this example, three compression rollers are arranged at equal intervals in the rotation direction of the rotor 27, and two of the rollers simultaneously press one suction tube, so that ink suction can be performed most efficiently with a small number of parts. Can do well.

As shown in FIG. 4B, a disc-shaped gear 36 is fixed to the upper end of the rotating shaft (pump shaft) 35 of the rotor 27. The gear 36 meshes with a gear 37 fixed to a drive shaft of a motor 38 that can be driven forward and reverse.
The rotation driving force of the motor 38 is transmitted to the rotation shaft 35 via both the gears 36 and 37. That is, the rotor 27 can be rotated forward or backward by switching the rotational drive direction of the motor 38 between forward and reverse.

When the motor 38 is driven in the forward rotation, only the black compression roller 26B moves to the compression position (FIG. 5), and when the motor 38 is driven in the reverse rotation, the color compression roller 26B is moved.
Only C moves to the compression position (FIG. 6). In other words, by switching the drive of the motor 38 in the forward and reverse directions, the suction of the black ink and the suction of the color ink can be performed separately.

With the above configuration, the maintenance mechanism 20 selectively generates a suction force only in one of the color ink tubes 24 and the black ink tube 25 by switching the driving of the motor 38. Thus, the suction of the low-viscosity color ink composed of the dye ink and the highly viscous black ink composed of the pigment ink can be separately performed. Therefore, the color ink suction time and the black ink suction time are set optimally,
Maintenance of the ink heads 12c, 12m, 12y, and 12k can be performed while minimizing the amount of ink wasted by suction. That is, in the related art, since ink suction is performed simultaneously for all the ink heads of C, M, Y, and K, if the ink suction time required for the black ink is set, more color ink than necessary is sucked. According to the present invention, such inconvenience can be prevented by setting the black ink suction time longer than the color ink suction time.

Further, since the suction of the color ink and the suction of the black ink can be respectively performed optimally without using a plurality of tube pumps, there is no problem that the maintenance mechanism and the printer are enlarged.

However, since the suction of black ink and the suction of color ink are switched by changing the direction of rotation of the motor, the suction of the black ink tube 25 and the color ink tube 24 in the tube pump 22 is performed. The directions are opposite to each other. For this reason, it is necessary to cross one of the tubes outside the pump case 28. In the example of FIG.
4 crosses. This allows both tubes 2
The suction and discharge directions of 4, 25 are aligned.

Further, in the above configuration, since both of the color ink tube 24 and the black ink tube 25 cannot be simultaneously pressed by the tube pressing roller 26 to be in the closed state, the cap unit is attached to the ink head unit 12 when not in use. Even if the nozzle 21 is in close contact, the ink heads 12c, 12m, 12y or 12k come into contact with the outside air through one of the tubes, and it is not possible to effectively prevent the ink remaining in the ink discharge nozzle from drying. The outlets of both tubes 24 and 25 are both waste ink unit 2
3, the waste ink unit 23 needs to exhaust the intake air from the tube pump 22 and has no airtightness. Therefore, in the above configuration, the inside of the cap 21 passes through the waste ink unit 23 and one of the tubes. Becomes in communication with the outside.

In order to prevent such a problem, the printer 1 of the present invention is provided with, for example, a tube holding mechanism 39 as shown in FIG. That is, the tube holding lever 41 is attached to the cabinet 40 of the printer 1.
When the printer 1 is not in use, the tube holding lever 41 is operated, and at least the tube pump 22
The space inside the cap 21 is shut off from the outside air by pressing the suction tube which is in the open state (non-pressed state). As a method of operating the tube holding lever 41 when the printer 1 is not used,
For example, the tube holding lever 4 is biased by a biasing means such as a spring.
1 is always urged in the direction of non-compression state,
A method of moving (rotating in the illustrated example) in the direction of the pressing state by using a driving means such as a solenoid when the device is not used is considered. The place where the tube is held down by the tube holding mechanism 39 may be on the way from the cap 21 to the waste ink unit 23, but it is desirable that the place between the cap 21 and the tube pump 22 is as close as possible to the cap 21. This is because the hermetically sealed space at the time of holding down the tube is reduced, and the effect of preventing ink drying can be increased.

The present invention is not limited to the above embodiment. For example, when the maintenance of the ink heads 12c, 12m, 12y, and 12k is performed by suctioning the ink, the suction time of the black ink is changed to the time of the color ink. Instead of making the suction time longer than the suction time, the suction force for the black ink may be made stronger than the suction force for the color ink. In this case, gears 36 and 37 for transmitting a driving force from a motor 38 as a driving source to a rotating shaft 35 of the rotor 27
For example, the rotation speed of the pump at the time of sucking the black ink may be increased by switching the power transmission system. Further, the suction time of the black ink may be longer than the suction time of the color ink, and the suction force of the black ink may be longer than the suction force of the color ink. As a specific example, it is conceivable that the rotational speed of the rotor is made faster for black than for color, or the diameter of the roller for black is made larger than that for color.

Further, in the configuration example of the rotor 27 shown in FIGS. 4 to 6, the first holder portion 27C and the second holder portion 27B constituting the rotor 27 are respectively formed by separate holding plates. The holding plate 31a on the upper side of the first holder 27C and the holding plate 32b on the lower side of the second holder 27B are formed of a common member, for example, as shown in FIG. 9, thereby simplifying the structure of the rotor 27. The size can be reduced. In this case, the bearing portions 33C and 33B formed on the common holding plate 42 are formed by substantially arc-shaped grooves. However, the configurations of FIGS. 4 to 6 can easily attach the compression rollers 26C and 26B to the rotor 27.

In the above embodiment, the tube pump 22
When is not driven, the compression rollers 26C and 26B stopped in the state 34a in which the suction tubes 25 and 24 are compressed may be pushed back to the non-compression position side 34b by the restoring force of the suction tube, and the compression state 34a may be released. It is preferable that both tubes are pressed and closed by the tube pressing mechanism 39.

(Second Embodiment) Next, a configuration for preventing the compression roller at the compression position from returning to the non-compression position due to the elasticity of the suction tube during pump suction will be described with reference to FIG.
This will be described with reference to 0 to 13. The same components as those described above are denoted by the same reference numerals, and description thereof will be omitted. The feature of this embodiment is that the shape of each end 34a, which is the compression position of the bearing 33C of the first holder 27C and the bearing 33B of the second holder 27B, is improved. I will explain mainly.

FIG. 10 shows an end portion 34a which is a pressing position of the bearing portion 33C of the first holder portion 27C of the second embodiment.
′, And the end portion 34a is inserted into the bearing portion 33C.
And a curved portion 34c which is located radially outward of the rotor 27 from the end 34b to prevent the roller from returning from the end 34a 'to the end 34b due to tube elasticity when the roller is pressed. To provide.

The bearing 33C of the present embodiment has an end 34
b, a gentle hole is formed so that the distance from the central axis O in the longitudinal direction of the rotor 27 gradually increases from the curved portion 34c to the rotor 2 from the curved portion 34c to the end 34a '.
7, a hole which gradually approaches the central axis O in the longitudinal direction is formed. That is, assuming that the distances between the central axis O and the end portions 34b, the curved portions 34c, and the end portions 34a '(distances between the side surface on the central axis O side and the central axis O) are r1, r2, and r3, respectively, r2>
r3> r1.

As described above, the curved portion 34c is attached to the bearing portion 33C.
By providing a recess (step) in the radial direction (the direction of the central axis O) in the trajectory of the shaft 26A with respect to the end 34a ', the elastic force that the compression roller 26C receives from the tube at the end 34a' and the curved portion 34c Is curved portion 34c from end portion 34a
Is larger than the elastic force difference from the tube based on the difference between the two positions 34a 'and 34c.
As long as 6C is not received substantially in the direction of the end 34b, the pressing roller 2
6C extends beyond the bent portion 34c from the end 34a 'to the end 34b.
Do not move to In the present embodiment, the bent portion 34c and the end 34a 'are provided adjacent to each other.

The difference between the two positions 34a 'and 34c (step: the difference in the distance between the side surface on the side of the central axis O and the central axis O (r2-r
3)) requires a radial distance that allows the compression roller to move to the non-compression position 34b when the pump rotation is reversed. In the present embodiment, the axis A2 of the pressing roller
6 has a diameter of 3 mm, and is positioned at both positions 34a 'and 3a.
The step (r2-r3) of 4c is set in the range of 0.2 mm to 0.3 mm, and the amount of drop can prevent the roller from returning due to the elasticity of the tube. Note that the bearing 33B has the same configuration and is provided with the end 34a 'and the curved portion 34c, and the description is omitted. FIG. 11A shows the position of each roller when the pump rotates forward, and FIG. 11B shows the position of each roller when the pump rotates reversely.

FIG. 12 shows that the tube 33 is provided with a curved portion 34c (step) in the bearing portion 33B of the second holder portion 27B, and further, the roller orbital shape has a braking function against the return of the compression roller 26B. The configuration for preventing the roller from returning due to elasticity is shown.

The return-prevention brake section is moved to the non-compression position (34).
b) and a substantially curved portion 34 substantially parallel to the circumference of the bearing portion 33B (compression roller movement trajectory) from the compression position (34a ').
c, a notch S for providing an opening S1 in the substantially curved portion 34c from the non-compression position 34b, and the bearing 33
The width W of B is smaller than the diameter R of the shaft A26 of the compression roller 26B. By providing the opening S1 in the cut portion S, the side surface of the bearing portion 33B on the cut portion S side can swing about the non-compression position 34b (opposite to the opening S1), and as a result, the width W of the bearing portion 33B. Are variable with elastic force.

The position where the cutout S and the opening S1 are provided may be any configuration as long as the width W of the bearing 33B has an elastic force. The cutout S is provided on the shaft core side or both sides of the bearing 33B. The opening S1 may also be in the non-compression position (34).
It may be provided at any position from b) to the compression position (34a ').

With the above configuration, even if the compression roller 26B at the compression position (34a ') receives a force in the direction of the non-compression position (34b) due to the tube elasticity, the curved portion 34c (step).
And the width W of the bearing portion 33B is smaller than the diameter R of the shaft A26 of the compression roller 26B while having elasticity, so that the compression roller 26B can be prevented from returning. Of course, at the time of the reverse rotation of the tube pump, the return brake pressure is set such that the return from the compression roller compression position (34a ') to the non-compression position (34b) is possible. The bearing 33C of the first holder 27C may have the same configuration.

The width W of the bearing portion 33B of the present embodiment is equal to the width W in FIG.
When the diameter of the pressure roller shaft A26 is 3.0 mm, the groove width W is set to 3.15 mm. In the present embodiment, the groove width W in the return prevention brake portion is 3. Omm
2.85mm to 2.70m in smaller, narrow places
The groove width is m. By making the groove width W smaller than the diameter of the pressure roller shaft A26, the return of the compression roller 26B can be prevented.

FIG. 13 shows a configuration in which the outer shape of the compression roller is knurled to prevent the compression roller from slipping from the compression position and returning to the non-compression position during pressurization due to tube elasticity. In the present embodiment, a knurled shape is provided in which the depression D is continuously provided on the outer peripheral surface of the compression roller 26B which is a compression portion with the tube. Hollow D
Are provided continuously in the circumferential direction and the axial direction of the outer peripheral surface, respectively.

According to this configuration, since the outer peripheral surface of the compression roller 26B and the tube come into contact with each other at two or more locations, the compression roller 26B hardly rotates even when it receives the elastic force from the tube, and returns to the non-compression position. Is preventing that.

Although the configuration in which the curved portion 34c (step) is provided in the bearing portion 33B as shown in FIGS. 12 and 13 has been described, the configuration in which only the return preventing brake portion and the knurled compression roller are provided without providing the curved portion 34c. However, it is possible to prevent the compression roller from sliding from the compression position and returning to the non-compression position during pressurization. The degree of slip prevention can be adjusted by changing the groove width W of the bearing portion and the knurl shape of the outer periphery of the compression roller in the return prevention brake portion.

(Third Embodiment) However, in the configuration of the tube pump, the following problems may occur. That is, in the tube pump of FIG.
Either forward rotation or reverse rotation of the motor sucks black ink or color ink. Then, when the suction operation is completed and the rotation of the motor is stopped, in the tube that has been performing ink suction until then, the pressing roller is stopped in a state where the tube is pressed against the tube, and at least a part of the tube in the tube pump is It will be closed.

At this time, on the ink head side at the maintenance position, in order to prevent the ink head from drying, the ink head is on standby with the cap in close contact with the ink head.
Therefore, in this standby state, the tube between the cap and the tube pump is in a sealed state.

During this standby state, if the atmospheric pressure decreases in the external environment, the pressure increases relatively in the sealed portion of the tube, and the ink increases and the residual ink in the tube flows back to the cap side. There is a problem that ink leakage occurs. Here, in the tube pump in the state of FIG. 5, by rotating the motor 38 in the reverse direction, the pressing state of the pressing roller 26B of the black tube 25, which is in the pressing state at that time, is released to prevent the ink leakage. However, as shown in FIG. 6, on the contrary, the color tube 24 is brought into the pressed state, and as a result, it is impossible to release the pressed state in both the black tube and the color tube.

Thus, in the third embodiment, the black ink and the color ink can be separately suctioned by using one motor that can be driven forward and backward, and both the black ink and the color ink can be sucked. A configuration for preventing the ink leakage in the tubes 24 and 25 due to a decrease in the external atmospheric pressure will be described below.

The schematic structure of the maintenance mechanism in the ink jet printer according to the third embodiment will be described with reference to FIGS. The same components as those described above are denoted by the same reference numerals and description thereof will be omitted. The driving force transmission mechanism 50 provided between the black holder and the color holder, which is a feature of the present embodiment, will be mainly described. explain.

In the above embodiment, the color pressure roller 2
The first holder 27C holding 6C and the second holder 27B holding three black compression rollers 26B for pressing the black ink tube 25 can be rotated synchronously via a rotor shaft 27a.

On the other hand, as shown in FIG. 14 (b), the tube pump of the present embodiment comprises a first holder 27C holding a color compression roller 26C and a second holder 27B holding a black compression roller 26B. Is provided on the concentric axis, but the first holder portion 27C and the second holder 27B do not always rotate in synchronization with each other, but only one of the holders can rotate.

More specifically, the first holder portion 27C and the second holder 27B are formed of different members, and the driving force transmission mechanism 50
, The rotational driving force is transmitted between the holders. In the present embodiment, the driving force from the motor 38 can be transmitted from the second holder 27B to the first holder 27C via the driving force transmission mechanism 50.

The driving force transmission mechanism 50 is provided on a first engagement shaft portion 52 (FIG. 15) provided on the lower surface of the second holder 27B for black and on an upper surface of the first holder portion 27C for the collar. And a second engaging shaft portion 54 (FIG. 16). Then, only when the first engagement shaft 52 and the second engagement shaft 54 are in contact with each other in a predetermined state, the second holder 27B for black is moved to the first holder 27C for collar. The rotational driving force is transmitted.

FIG. 15 shows the configuration of the second holder 27B which is arranged on the upper side of the tube pump and rotates by receiving the driving force from the motor 38. The second holder 27B includes holding plates 32a and 32 for holding a compression roller (not shown).
b, a rotary shaft 35 having a gear portion for receiving a driving force from the motor 38, and an engagement shaft portion 52 disposed on the lower surface side of the holding plate 32b.

The engaging shaft portion 52 has an annular cylindrical body 52a provided on the same axis as the rotary shaft 35, and a predetermined thickness extending in the radial direction and the longitudinal direction on the outer peripheral surface of the cylindrical body 52a. Of the cylindrical body 52 is fixedly provided.
The inside of a is a support shaft 29 rising from the bottom surface of the guide wall 29.
a (FIG. 14B) is a through hole 52c.

FIG. 16 shows the configuration of a driven-side first holder 27C which is arranged on the lower side of the tube pump and rotates by receiving a driving force from the second holder 27B. The first holder 27C includes holding plates 31a and 31b for holding a compression roller (not shown), and a holding plate 31.
a, which has an engagement shaft portion 54 formed on the upper surface side for stably supporting the driving side holder and transmitting the driving force from the second holder portion 27B.

The engagement shaft portion 54 has an annular member 54a and a driven contact member 54b extending in the center axis direction on the inner peripheral surface of the annular member 54a.

FIG. 17 shows that the engagement shaft 52 is
4 shows a state in which the cylindrical member 52a is engaged via the concentric shaft 29a, and the tubular member 52a is housed in the annular member 54a, and the drive contact member 52b and the driven contact member 54b can be pressed in the rotational direction. Is formed. Therefore, the driving force from the second holder 27B on the driving side to the first holder portion 27C on the driven side is transmitted when the driving contact member 52b and the driven contact member 54b are in the contact state. Note that FIG.
Indicates a reverse rotation drive (or a stop state immediately after the reverse rotation drive). At this time, the drive contact member 52b is in contact with the driven contact member 54b from the downstream side in the clockwise direction. (Second contact state).

On the other hand, at the time of the forward rotation drive (or at the time of the stop state immediately after the forward rotation drive), the drive contact member 52b comes into contact with the driven contact member 54b from the upstream side in the clockwise direction. (First contact state). That is, when the driving contact member 52 and the driven contact member 54 are in the first contact state, the driving force transmission mechanism 50
Is the first holder portion 27 on the driven side from the second holder portion 27B.
A clockwise forward rotation driving force can be transmitted to C.

When the driving contact member 52b and the driven contact member 54b are in the second contact state,
The driving force transmission mechanism 50 is configured to move the first holder
A counterclockwise reverse driving force can be transmitted to the holder 27C.

Next, an operation for releasing the pressing state of the compression roller against the black and color suction tubes when the pump is stopped in the driving force transmission mechanism 50 having the above configuration will be described. FIG. 18A shows an operation during black suction (black prime operation) by forward rotation of the motor 38. At this time, the driving force transmission mechanism 50 is in the first contact state, for black. Is in the pressed state, and the color pressing roller 26C is in the non-pressed state.

Here, when the driving of the motor is stopped, the black compression roller 26B stops in the pressed state, and there is a possibility that ink may leak from the cap on the black ink head side. Must be released. Therefore, as shown in FIG. 18 (b), the motor is reversed from the normal rotation drive to the reverse rotation drive, and only the second holder 27B for black is driven to rotate in the reverse direction, so that the black compression roller 26B is driven.
Is released. And the black compression roller 26B
In a state in which both the color pressing roller 26C and the color pressing roller 26C are in the non-pressing state, the standby state is established.

That is, when the motor is reversed from the forward rotation drive to the reverse rotation drive, the second holder 27B for black, which is the drive side holder, directly receives the driving force from the motor and rotates, but is the driven side holder. First holder 27C for color
Is a period until the contact state of the driving force transmission mechanism 50 is switched from the first contact state to the second contact state (in the configuration of FIG. 18A, the rotation angle is about 360 degrees). The driving force is not transmitted, and the non-pressing state of the pressing rollers 26B and 26C can be maintained.

In the above-described reversal drive, the rotation angle is α degrees (FIG. 15B) which is the angle of formation of the bearing portion of the compression roller in the holder in order to reliably release the pressed state of the black compression roller 26B. (FIG. 17) The above angle (the angle from the compression position (34, 34a ') to the non-compression position (34b)) is required. Therefore, in FIG.
By performing the inversion drive of α degrees or more and 360 degrees or less, the compression state of the black compression roller 26B can be released while the non-compression state of the color compression roller 26C is maintained.

Next, FIG. 19A shows an operation (color prime operation) at the time of color suction by the reverse rotation driving of the motor. At this time, the driving force transmission mechanism 50 is in the second contact state. In this state, the black compression roller 26B is in a non-compression state, and the color compression roller 26C is in a compression state.

Here, when the driving of the motor is stopped, the pressure roller 26C for color stops in the pressed state, and there is a possibility of ink leakage from the cap on the color ink head side. Need to be released from pressure. For this reason, as shown in FIG. 19B, the motor is reversed from the reverse rotation drive to the normal rotation drive, and the color compression roller 26C is released from the compression state by driving the color holder 27C to rotate forward.

At this time, since the driving force must be transmitted via the black holder 27B in order to drive the color holder 27C in the normal rotation, the driving force transmitting mechanism 50 is in the second contact state. Requires about 360 degrees of rotation to switch from to the first contact state. Further, after switching to the first contact state, an angle of α degrees or more (FIG. 17) is required to reliably release the compression state of the color compression roller 26 </ b> C. The rotation angle is 360 + α
More than necessary.

In the reversing drive shown in FIG. 19B, the black compression roller 26B is switched to the compression state without maintaining the non-compression state by simultaneously rotating the black holder 27B in the normal rotation. Therefore, as shown in FIG. 19C, the motor is again reversed from the normal rotation drive to the reverse rotation drive, and only the black holder 27B is reversely driven to release the compression state of the black compression roller 26B. . The black compression roller 26B and the color compression roller 26C are in a non-compression state, and are in a standby state.

The driving in FIG. 19C is the same operation as the driving in FIG. 18B. That is, in FIG. 19C, by performing the inversion drive of α degrees or more and 360 degrees or less, the compression state of the black compression roller 26B is released while the non-compression state of the color compression roller 26C is maintained. be able to.

In the driving force transmission mechanism 50 described above, since one driving contact member 52b and one driven contact member 54b are provided, switching between the first contact state and the second contact state is performed. In this case, it is necessary to rotate the drive-side holder 27B about one turn, and the time lag at the time of switching the drive direction increases, but as shown in FIGS. 20 (a) and 20 (b), the drive contact member 52b or the driven contact member If at least one of the 54b is provided, two or more rotation angles required for switching the contact state can be reduced, and the time lag at the time of driving direction switching can be reduced (FIG. 20A,
In the configuration of (b), the rotation angle required for switching the contact state is β degrees).

As shown in FIG. 20C, one of the drive contact member 52b and the driven contact member 54b may be formed as a groove. However, in the configurations of FIGS. 20A to 20C, although the time lag at the time of switching the driving direction can be reduced, the margin of the rotation angle for releasing the pressure of the compression roller is smaller than that of the configuration of FIG. In addition, the accuracy of the rotation angle control of the motor is required. That is, FIG.
In the configurations of 0 (a) to (c), the reversal drive angle for releasing the pressure of the compression roller needs to be α degrees or more and β degrees or less.

In the suction operation by the tube pump, the black ink and the color ink can be suctioned separately. For example, when the black ink head is clogged, etc. Alternatively, the user may be able to perform an operation input so that only the black ink is sucked in the head cleaning.

However, in the normal head maintenance operation automatically performed by the printer, both the black ink and the color ink are suctioned. In this case, the ink corresponding to the driven side holder is suctioned first. It is preferable that the suction of the ink corresponding to the drive side holder is performed later. This simplifies the compression release processing of the compression roller after the suction is completed (the compression release processing can be performed by the processing of FIG. 18 instead of the processing of FIG. 19).

With the above configuration, by releasing the pressing state of the pressing roller against the suction tube, it is possible to prevent ink leakage due to a decrease in the external air pressure. At the same time, it is possible to prevent the tube from being deformed or deteriorated due to the long-term pressing force acting on the suction tube during standby.

[0120]

As described above, according to the ink jet printer of the present invention, when the printer is not in use, the internal space of the cap that is in close contact with the ink head unit is divided into a suction space for color ink and a suction space for black ink. In order to separately perform the suction operation by the suction tube connected to the suction space for the color ink and the suction operation by the suction tube connected to the suction space for the black ink, the ink is sucked. The suction of the color ink and the black ink can be performed separately without increasing the number of pumps for the ink supply, thereby preventing unnecessary ink suction during maintenance of the ink head.

Further, the first holder portion and the second holder portion are arranged on the rotor in the direction of the rotation axis of the rotor, and each bearing portion is provided, so that the movement of each compression roller between the compression position and the non-compression position can be easily performed. Can be realized.

Further, in the first bearing portion of the first holder portion and the second bearing portion of the second holder portion, the positional relationship between the compression position and the non-compression position in the rotor rotation direction is reversed. Therefore, by simply changing the rotation direction of the rotor, one of the color compression roller and the black compression roller can be selectively positioned at the compression position, and the other can be positioned at the non-compression position. Therefore, by switching the direction of the rotational drive between the normal and reverse directions, the suction of the black ink and the suction of the color ink can be performed separately, and the suction pump can be realized with a simpler configuration.

Further, the color pressure roller for pressing the color suction tube and the black pressure roller for pressing the black suction tube are provided with a pressure position for pressing the suction tube and a non-pressure position for not pressing the suction tube. Between the color compression roller and the black compression roller when the suction pump is in operation. Since the suction operation by the black suction tube can be performed separately, the suction pump can be realized with a simple configuration.

Further, by using a motor capable of driving forward and reverse rotation as the drive source of the rotor and switching the direction of rotation of the motor between forward and reverse, it is possible to separately perform suction of black ink and suction of color ink. With such a configuration, the suction pump can be realized with a simpler configuration.

Further, at least one of the suction tube for black ink and the suction tube for color ink is pressed and closed in the middle of the path from the cap to the waste ink storing portion when the printer is not used. By having the pressing mechanism, the space in the cap is shut off from the outside air, and the drying of the ink remaining in the ink discharge nozzles of the ink head can be prevented.

Further, the first state, the second state, and the third state are made possible in the drive transmission mechanism, and after suction is completed, the driven-side holder is driven by the third state of the drive force transmission mechanism. The compression state of the compression roller of the drive-side holder can be released while the non-compression state of the compression roller is maintained. Thereby, the compression state of all the compression rollers can be simultaneously released in the tube pump that enables suction to only one of the tubes by switching the rotation direction of the rotor,
If the external pressure drops due to the pressure difference from the outside of the tube, the pressure inside the tube rises and ink leaks out from between the head and cap, preventing backflow to the ink head side and prolonged pressure on a certain part of the tube. Can prevent the tube from being deformed.

Further, the first holder and the second bearing are formed so that the positional relationship between the compression position and the non-compression position in the rotor rotation direction is reversed (symmetrical with respect to the radial direction of the rotor), so that the first holder is formed. It is possible to move the compression roller of the portion and the second holder portion between the compression position and the non-compression position at a small angle.

The driving force transmitting mechanism includes a first and a second contact member formed on a concentric circle centered on a rotation axis on the opposing surfaces of the driving side holder and the driven side holder. The first or second state when the first contact member contacts the second contact member from the upstream side in the forward or reverse rotation direction. By taking the third state when the second contact member is not in the contact state, the driving force transmission mechanism is realized with a simple configuration.

Further, the first contact member and the second contact member are configured to require substantially one rotation for switching from the first state to the second state. The margin can be widened.

Further, at least one of the first contact member and the second contact member has a contact interval with the other contact member of less than one rotation, so that the second contact member is moved from the first state to the second contact member. Switching to the state can be performed quickly.

In the case of performing the suction process for both the color ink and the black ink, by performing the suction operation of the ink corresponding to the driven side holder first, the pressure release process after the suction process is completed is simplified.

The bearing portion has a curved portion radially outward from the compression position between the compression position and the non-compression position, so that when the roller is pressed, the compression roller at the compression position is not compressed by the elasticity of the suction tube. It can be prevented from being returned to the position.

The bearing portion is a groove or a hole for supporting the support shaft of the compression roller movably between the compression position and the non-compression position. When the compression roller moves from the compression position to the non-compression position, the bearing portion is The support shaft has an elastic portion that applies a predetermined elastic force.When the elastic portion applies a predetermined elastic force to the support shaft of the compression roller when moving from the compression position to the non-compression position, the elastic force is applied when the roller is pressed. Further, it is possible to prevent the compression roller at the compression position from returning to the non-compression position due to the elasticity of the suction tube.

The elastic portion has a pressing side surface having a groove or hole of the bearing portion narrower than the supporting shaft of the compression roller, and a supporting portion for swingably supporting the pressing side surface. The elastic part can be easily configured.

The compression roller for color and the compression roller for black are
At each compression position, a protrusion that presses at least two places with the tube is provided in the circumferential direction of the roller, so that at the compression position, at least two protrusions arranged in the circumferential direction of the roller press the roller. Therefore, the roller is stable in the circumferential direction and can be prevented from returning to the non-compression position due to the elasticity of the suction tube.

A plurality of compression rollers are respectively held by the first holder portion and the second holder portion, and two or more compression rollers are simultaneously pressed against one suction tube, thereby providing a suction tube. The ink in the tube is moved to the discharge side in a state where the ink is sealed between the two rollers, so that a suction force can be reliably generated.

In addition, since three compression rollers are held by the first holder part and the second holder part, and these are held at equal intervals in the rotation direction of the rotor, the most efficient suction of ink can be achieved with a small number of parts. Can do well.

Further, by making the suction time of the black ink longer than the suction time of the color ink or making the suction force for the black ink stronger than the suction force for the color ink, the amount of ink wasted by the suction is minimized. It is possible to carry out maintenance of the ink head while keeping it to a minimum.

[Brief description of the drawings]

FIG. 1 is an external perspective view of an inkjet printer according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram operatively describing a printing mechanism of the ink jet printer shown in FIG.

FIG. 3 is a schematic configuration diagram operatively describing a printing unit and a maintenance mechanism in the inkjet printer according to the embodiment of the present invention.

FIG. 4A is a front view of a tube pump in the inkjet printer according to the embodiment of the present invention, and FIG. 4B is a longitudinal sectional view of the tube pump.

FIG. 5A is a front view of the tube pump according to the embodiment of the present invention when black ink is sucked, and FIG. 5B is a longitudinal sectional view of the tube pump.

FIG. 6A is a front view of the tube pump according to the embodiment of the present invention when the color ink is sucked, and FIG. 6B.
FIG. 2 is a vertical sectional view of the tube pump.

FIG. 7 is a perspective view showing an arrangement relationship between a guide wall 29 and a tube.

FIG. 8 is an explanatory diagram of a tube holding mechanism in the ink jet printer according to the embodiment of the present invention.

FIG. 9 is a longitudinal sectional view of another tube pump in the ink jet printer according to the embodiment of the present invention.

FIG. 10 is a front view of a first holder 27C according to a second embodiment of the present invention.

FIG. 11A is a front view of the first and second holder portions when the rotor according to the second embodiment of the present invention is rotated forward, and FIG. 11B is a front view of the first and second holder portions when the rotor is rotated reversely. FIG.

FIG. 12 shows a second holder 2 according to another embodiment of the present invention.
It is a front view of 7B.

FIG. 13 shows a second holder 2 according to another embodiment of the present invention.
It is a front view of 7B.

FIG. 14A is a front view of a tube pump in an ink jet printer according to a third embodiment of the present invention, and FIG. 14B is a longitudinal sectional view of the tube pump.

FIG. 15A is a side view of a second holder 27B according to a third embodiment of the present invention, and FIG. 15B is a front view of the second holder 27B.

16A is a side view of a first holder 27C according to a third embodiment of the present invention, and FIG. 16B is a front view of the first holder 27C.

FIG. 17 is an explanatory diagram of a contact state between a driving contact member 52b and a driven contact member 54b of a driving force transmission mechanism 50 according to a third embodiment of the present invention.

FIG. 18 is an explanatory diagram illustrating a transition from a first contact state (a) to a third contact state (b) of the driving force transmission mechanism 50 according to the third embodiment of the present invention.

FIG. 19 is an explanatory diagram illustrating a transition from a first contact state (a) to a third contact state (b) of a driving force transmission mechanism 50 according to a third embodiment of the present invention.

FIG. 20 shows another driving contact member 52b and a driven contact member 54b of the driving force transmission mechanism 50 according to the third embodiment of the present invention.
It is explanatory drawing of the contact state.

FIG. 21 is a schematic configuration diagram operatively describing a printing unit and a maintenance mechanism in a conventional inkjet printer.

FIG. 22A is a front view of a tube pump in a conventional inkjet printer, and FIG.
(B) is a longitudinal sectional view of the tube pump.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inkjet printer 9 Printing part 10 Ink cartridge 12c, 12m, 12y, 12k Ink head 12 Ink head unit 13 Ink tank 20 Maintenance mechanism 21 Cap 22 Tube pump (suction pump) 23 Waste ink unit 21a Suction space for color ink 21b Black Suction space for ink 24 Suction tube (tube for color ink) 25 Suction tube (tube for black ink) 26 Tube compression roller (tube compression means) 26C Color compression roller 26B Black compression roller 27 Rotor 27C First holder Part 27B Second holder part 27a Rotor shaft 29 Guide wall 31a, 31b Holding plate 32a, 32b Holding plate 33C Bearing part (substantially circular hole) 33B Bearing part (substantially circular hole) 34a, 3 4a 'One end 34b The other end 34c Bent portion 38 Motor (drive source) 39 Tube holding mechanism 41 Tube holding lever S Notch S1 Opening D Dent 50 Driving force transmission mechanism 52, 54 Engagement shaft 52B Contact member 54b Followed contact member

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masanobu Exit 22-22, Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Koichi Irihara 22-22, Nagaike-cho, Abeno-ku, Osaka-shi, Osaka F-term (for reference) in JAP Corporation 2C056 EA14 EA25 EA27 EC24 JC08 JC20

Claims (20)

[Claims] An ink head unit having a plurality of ink ejection heads is moved along a recording sheet, and ink of a different color is selectively ejected from each ink ejection head of the ink head unit. An ink jet printer that prints at least a color image on the recording paper by adhering to the recording paper, wherein a cap that detachably adheres to the ink head unit so as to cover the ink ejection head of the ink head unit, A suction pump for sucking ink from the ink ejection head in a state of being in close contact with the head unit, wherein the cap has suction spaces separately for color ink and black ink, and each suction space has , Each suction tube pulled out from the suction part of the suction pump An ink-jet printer wherein a suction operation of a color ink tube is realized by rotation of a suction pump in one direction, and a suction operation of a black ink tube is realized by rotation in a reverse direction. 2. The suction pump for a color ink and a black ink for suction between a rotor which rotates while holding a tube pressing means on an outer peripheral portion and a substantially cylindrical guide wall surrounding the rotor. For driving the rotor in the normal and reverse directions to press the color ink and black ink tubes between the tube pressing means and the guide wall. The ink jet printer according to claim 1, wherein: 3. The compression unit includes a color compression roller that compresses the color ink tube, and a black compression roller that compresses the black ink tube. The black compression roller is provided so as to be movable between a compression position in which the color ink tube is compressed by one rotation of the rotor and a non-compression position in which no compression is performed by rotation in the opposite direction. And a movable position between a non-compression position in which the black ink tube is not compressed by one rotation of the rotor and a compression position in which the black ink tube is compressed by rotation in the opposite direction.
An inkjet printer according to item 1. 4. The rotor has a first holder section for holding the color compression roller and a second holder section for holding the black compression roller, which are arranged side by side in the rotor rotation axis direction. 4. The ink jet printer according to claim 3, wherein a bearing portion is formed to movably support the compression roller between the compression position and the non-compression position. 5. A drive source for applying a rotational driving force to the rotor is capable of forward and reverse rotational drive, and the bearing is formed substantially along a rotor rotational direction,
And one of the roller support portions is a groove or a hole that is displaced in the radial direction of the rotor more than the other roller support portion, and the roller support portion radially outside the bearing portion forms the compression position, and A roller support portion radially inward of the portion forms the non-compression position; and a first bearing portion of the first holder portion and a second bearing portion of the second holder portion, wherein the compression position in the rotor rotation direction is provided. The ink jet printer according to claim 4, wherein the positional relationship between the non-compression position and the non-compression position is reversed. 6. A suction tube for black ink and at least one of suction tubes for color ink,
The ink jet printer according to any one of claims 1 to 5, further comprising: a tube pressing mechanism that presses and closes in the middle of a path from the cap to the waste ink storing unit when the printer is not used. 7. A drive source for applying a rotational drive force to the rotor is capable of forward and reverse rotational drive, and one of the first holder portion and the second holder portion receives a rotational drive force from the drive source. A driving-side holder, the other being a driven-side holder that receives a driving force from the driving-side holder via a driving-transmission mechanism, wherein the driving-transmission mechanism transmits a forward rotation driving force from the driving-side holder to the driven-side holder; And a third state in which only the drive-side holder is driven to rotate forward or backward by a first state, a second state in which a reverse drive force is transmitted from the drive-side holder to the driven-side holder, and a suction state. 5. The ink jet printer according to claim 4, wherein the pressing rollers of the first holder portion and the second holder portion after the operation is released from the pressing position. 8. The bearing portion is formed substantially along the direction of rotation of the rotor, and is a groove or a hole in which one roller supporting portion is displaced in the radial direction of the rotor more than the other roller supporting portion, A roller support portion radially outside the bearing portion forms the compression position, a roller support portion radially inside the bearing portion forms the non-compression position, and a first bearing portion of the first holder portion. 8. The ink jet printer according to claim 7, wherein a positional relationship between the compression position and the non-compression position in the rotor rotation direction is formed in the second bearing portion of the second holder portion in reverse. 9. The driving force transmission mechanism includes first and second abutments formed on concentric circles about a rotation axis on respective opposing surfaces of the driving-side holder and the driven-side holder. The first or second state when the first contact member contacts the second contact member from the upstream side in the forward or reverse rotation direction. The ink jet printer according to claim 7, wherein the third state is set when the second contact member is not in the contact state. 10. The switch according to claim 1, wherein the first contact member and the second contact member are substantially one at a time of switching from the first state to the second state.
The inkjet printer according to claim 9, wherein the inkjet printer requires rotation. 11. The apparatus according to claim 9, wherein at least one of the first contact member and the second contact member has a contact interval with the other contact member of less than one rotation. Inkjet printer. 12. The ink jet printer according to claim 7, wherein when performing suction processing of both the color ink and the black ink, the suction operation of the ink corresponding to the driven side holder is performed first. 13. The ink jet printer according to claim 5, wherein the bearing has a curved portion between the compression position and the non-compression position, which is radially outward from the compression position. 14. The bearing portion is a groove or a hole that movably supports a support shaft of a compression roller between the compression position and the non-compression position. When the bearing portion moves from the compression position to the non-compression position, 5. The ink jet printer according to claim 4, further comprising an elastic portion for applying a predetermined elastic force to a support shaft of the compression roller. 15. The elastic portion includes: a pressing side having a narrower groove or hole of the bearing portion than a supporting shaft of a compression roller; and a supporting portion for supporting the pressing side so as to swing. The inkjet printer according to claim 14, further comprising: 16. The color compression roller and the black compression roller each have a tube and a projection for pressing at at least two places in a circumferential direction of the roller at each compression position. The ink-jet printer as described. 17. A plurality of compression rollers are respectively held by the first holder portion and the second holder portion, and two or more compression rollers are simultaneously pressed against one suction tube. The inkjet printer according to claim 2. 18. The apparatus according to claim 18, wherein the first holder and the second holder each hold three or more compression rollers and are arranged at equal intervals in the rotation direction of the first holder and the second holder. The ink jet printer according to claim 5, wherein: 19. The ink jet printer according to claim 1, wherein a suction time for black ink is set longer than a suction time for color ink. 20. The ink jet printer according to claim 1, wherein a suction force for black ink is made stronger than a suction force for color ink.