JP2003170612A - Ink-jet printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make an apparatus compact in its entirety by cutting back a space whereto an ejection recovery mechanism of a printing head withdraws at the time of a printing. <P>SOLUTION: At the time of an ejection recovery process in a non-printing state, a platen belt 21 is rotated via rollers 22, 22 so as to move an opening part 21a of the platen belt 21 to a position facing the nozzle surfaces of printing heads 11, 12, 13, 14. Caps 31, 32, 33, 34 of a printing head recovery part 30 are brought into close contact with the nozzle surfaces of the printing heads 11, 12, 13, 14 via the opening part 21a so as to be in a capping state. The ink in the nozzles is sucked and discharged via holes in the caps 31, 32, 33, 34 for cleaning the nozzle surfaces. Moreover, drying of the nozzles can be prevented, and the nozzle surfaces can be protected in the case they are maintained in a non-printing state over a long term. <P>COPYRIGHT: (C)2003,JPO

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 that prints by ejecting ink from a print head section toward a recording medium.

[0002]

2. Description of the Related Art Generally, an ink jet printer ejects ink, as disclosed in Japanese Patent Application Laid-Open No. 9-57988, for example, a recording medium carrying section (paper carrying section) for carrying a recording medium such as paper. The print head unit (printing unit) is provided with a print head recovery unit (capping unit) for performing head maintenance (ejection recovery processing) for preventing defective ink ejection due to dirt or clogging of the head surface. . The print head unit has a plurality of ejection nozzles arranged on the surface facing the recording medium conveyance unit, and can be moved up and down with respect to the recording medium conveyance unit by a drive mechanism composed of a feed screw and a motor. The unit can be horizontally moved to a position facing the print head unit by a drive mechanism including a timing belt and a motor.

At the time of printing, the paper is placed on the conveyor belt, and the paper and the nozzle surface of the print head are opposed to each other with a slight gap therebetween, and are conveyed from the upstream side to the downstream side, and the printing is performed therebetween. ing. At this time, the print head recovery unit has moved to a retracted position that does not face the print head, and shifts from the printing state to the ejection recovery state through the following operations.

(1) The print head unit moves upward to form a space with the recording medium conveying unit.

(2) The print head recovery unit moves horizontally to a position facing the print head unit.

(3) The print head unit moves downward and comes into close contact with the print head recovery unit to perform an ejection recovery operation such as cleaning.

[0007]

However, in the prior art, the print head recovery section is arranged at a position retracted from the print head during printing, and is moved horizontally during the ejection recovery operation to face the print head nozzle surface. Placed in. That is, it is necessary to provide a space for arranging the print head recovery unit at a retracted position during printing, which is an obstacle to downsizing the entire apparatus.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an ink jet printer capable of reducing the space required for the ejection recovery mechanism of the print head to retract during printing and making the entire apparatus compact. I am trying.

[0009]

In order to achieve the above-mentioned object, an ink jet printer according to a first aspect of the present invention is a nozzle in which a conveying section for conveying a recording medium and a nozzle for ejecting ink to the recording medium are formed. A print head unit having a surface, a platen unit having a belt, a part of which is located on the back side of a recording medium that receives ink ejected from the nozzles, and a nozzle face of the print head unit via the belt of the platen unit And a print head recovery unit disposed opposite to the platen unit, and an opening in a part of the belt of the platen unit, during the ejection recovery process of the nozzle surface,
The print head recovery unit seals the nozzle surface through an opening of the belt.

An ink jet printer according to a second aspect is the ink jet printer according to the first aspect,
The opening of the belt moves to a position facing the nozzle surface and the print head recovery unit, the print head recovery unit moves upward, and the nozzle surface is sealed via the opening of the belt. A feature is that a discharge recovery process is performed.

An ink jet printer according to a third aspect is the ink jet printer according to the first aspect,
The opening portion of the belt moves to a position facing the nozzle surface and the print head recovery portion, the print head portion moves downward, and the nozzle surface is sealed and ejected through the opening portion of the belt. It is characterized by performing a recovery process.

An ink jet printer according to a fourth aspect is the ink jet printer according to the first aspect,
The recording medium has a detection means for detecting the meandering of the recording medium, and when the meandering of the recording medium is detected, the belt moves in a direction orthogonal to the conveying direction of the recording medium, thereby causing the recording medium to meander. Is suppressed.

That is, in the ink jet printer according to the first aspect, the belt of the platen portion is arranged at a position facing the nozzle surface of the print head portion, and the opening portion is provided in a part of this belt. Then, when the ejection is recovered, the belt of the platen part is rotated to move the opening to a position facing the nozzle surface of the print head part, and the print head part and the print head part are opposed to each other through this opening part. Since the discharge recovery process such as cleaning of the nozzle surface is performed in close contact with the print head recovery unit, the space for retracting the print head recovery unit at the time of printing is unnecessary, and the entire apparatus can be made compact.

At this time, in the ink jet printer according to the second aspect, when the belt of the platen portion is rotated and the opening is moved to a position facing the nozzle surface of the print head portion, the print head recovery portion is moved upward. Since it moves and comes into close contact with the nozzle surface of the print head section through the opening, the print head recovery section can perform ejection recovery processing by moving by one belt thickness, and the print head recovery section can move. It is possible to minimize the amount and make the entire apparatus compact.

Further, in the ink jet printer according to the third aspect, when the belt of the platen portion is rotated and the opening portion is moved to a position facing the nozzle surface of the print head portion, the print head portion is moved downward. Since the print head recovery unit comes into close contact with the print head recovery unit through the opening, the discharge recovery process can be performed by moving the print head recovery unit by one belt thickness. It is possible to make the entire device compact by minimizing the above.

Further, in the ink jet printer according to the fourth aspect, the belt of the platen portion is utilized not only at the time of ejection recovery but also at the time of printing, and when the recording medium meanders with respect to the nozzle area of the print head, the recording is performed. The position of the medium in the width direction is detected and the belt of the platen part is rotated in the direction orthogonal to the conveying direction of the recording medium. Therefore, the retracting space of the print head recovery part at the time of printing is reduced and the entire apparatus is made compact. It is possible to suppress the meandering of the recording medium and to print at the correct position while making efforts.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 relate to a first embodiment of the present invention. FIG. 1 is a perspective view of an essential part of an inkjet printer, and FIG. 2 is a perspective view showing a state of a platen belt during a discharge recovery operation.

As shown in FIG. 1, an ink jet printer 1 according to the present embodiment is provided with a print medium carrying section 5 for carrying a print medium 2 such as paper and a print provided with a plurality of print heads having nozzle rows for ejecting ink droplets. The head portion 10, the platen portion 20 having the platen belt 21 arranged at a position facing the nozzle surface of the print head, and the platen portion 21 are arranged inside the platen belt 21, and the head surface is contaminated or clogged by a cleaning process or a capping process The print head recovery unit 30 is provided for performing head maintenance (ejection recovery processing) for preventing ink ejection failure due to the above.

The recording medium conveying section 5 is provided with a sheet feeding roller 6 for conveying the recording medium supplied from a sheet feeding roll or the like (not shown), and a sheet discharging roller 7 for discharging the recording medium 2. In addition, the print head unit 10 is C
(Cyan), M (Magenta), Y (Yellow), K (Black) four-color print heads 11, 12, 13, 1
4 is provided. Each print head 11,1
The bottom surfaces of the heads 2, 13 and 14 are nozzle surfaces on which nozzles for ejecting ink are formed.

The platen section 20 includes a print head 11,
The platen belt 21 is arranged to face the nozzle surfaces of the nozzles 12, 13 and 14, and a pair of rollers 22 around which the platen belt 21 is bridged. The rollers 22 and 22 are rotated by a drive motor (not shown). By doing
The platen belt 21 moves in a direction orthogonal to the recording medium conveyance direction. In addition, the platen belt 21 is configured to be bridged by a pair of rollers 22 and 22.
It is also possible to have a structure in which one or more rollers are bridged over more than one roller and serve as tension rollers.

In addition, a part of the platen belt 21 has an opening 21 for exposing the nozzle surfaces of the print heads 11, 12, 13, 14 to the print head recovery section 30 side.
a is provided. The opening 21a is set at a position (a position below the print head recovery unit 30 in FIG. 1) apart from the nozzle surface of the print head unit 10 during the printing operation, and the roller 22 is used for the ejection recovery process. , 22 rotate and the platen belt 21 moves, the openings 21a move to positions facing the nozzle surfaces of the print heads 11, 12, 13, 14 as shown in FIG.

The print head recovery unit 30 has four color print heads 11, 12, 1 inside the platen belt 21.
Four caps 31, 32, 33, 34 are provided at positions facing the nozzle surfaces of 3, 14. Cap 31,
32, 33, and 34 are openings 31a on the upper surface,
The structure is such that it can be brought into close contact with the nozzle surface via 32a, 33a, 34a, and is connected to a suction pump (not shown) via a tube (not shown).

At least one of the print head unit 10 and the print head recovery unit 30 is configured to be vertically movable by, for example, a gear mechanism or a link mechanism connected to the roller 22. When the opening 21a of the platen belt 21 is moved to a position facing the nozzle surface of the print head portion by the rotation of the roller 22, the print head portion 10 and the print head recovery portion 30 operate so as to be in close contact with each other, and the nozzle The surface can be sealed.

In the ink jet printer 1 having the above structure, during the printing operation, the recording medium 2 is conveyed through the paper feed roller 6, and the print heads 11, 12, 13, 14 are placed on the platen belt 21 of the platen section 20. The sheet is conveyed by the sheet feeding roller 6 and the sheet discharging roller 7 while being supported so as to maintain an appropriate distance from the nozzle surface of the sheet. At the same time, ink is ejected from the nozzle rows of the print heads 11, 12, 13, 14 and the ejected ink is received by the recording medium 2 to print characters, images and the like.

On the other hand, during the ejection recovery process in the non-printing state, the roller 2 driven by a drive motor (not shown).
The platen belt 21 rotates via 2, 22, and as shown in FIG. 2, the opening 21a of the platen belt 21 moves to a position facing the nozzle surface of the print heads 11, 12, 13, 14. Then, the caps 31, 32, 33, 34 of the print head recovery unit 30 are connected to the print heads 11, 12, through the opening 21a of the platen belt 21.
The cap surfaces are in close contact with the nozzle surfaces 13 and 14 and seal the nozzle surfaces.

In this capping state, the suction pump is operated and the caps 31, 32, 33, and
The air inside the cap 34 is sucked, and the inside of the cap is in a negative pressure state. As a result, the ink is forcibly sucked from the nozzles, and the ejection recovery operation is performed in which the ejection failure of the nozzles is recovered and the deposits on the nozzle surface are removed. Further, in this capping state, when the inkjet printer 1 is kept in the non-printing state for a long period of time, the nozzle rows are prevented from being dried and the nozzle surfaces are protected.

As described above, in the ink jet printer 1 of the present embodiment, the space for retracting the print head recovery unit 30 at the time of printing is unnecessary, and the entire apparatus can be made compact.

Next, a second embodiment of the present invention will be described. 3 and 4 relate to the second embodiment of the present invention. FIG. 3 is an explanatory diagram showing the configuration around the print head recovery unit, and FIG. 4 is an explanatory diagram showing the state during the ejection recovery operation.

In the second embodiment, the print head recovery unit is moved up and down by a drive motor. As shown in FIG. 3, the print head recovery unit 30A of this embodiment has a slider mechanism 35 including a rack and a pinion. It is connected to the drive motor 36 through. The other basic configuration is the same as that of the first embodiment described above, the print head recovery unit 30A is connected to the suction pump 38 through the tube 37, and the drive motor 39 is connected to the roller 22 that drives the platen belt 21. It is lined up.

With such a configuration, during printing operation, as shown in FIG.
As shown in FIG. 5, the recording medium 2 is supported and conveyed on the platen belt 21 so as to maintain an appropriate distance from the nozzle surface of the print head unit 10, and ink is ejected from the nozzle row of the print head unit 10 to print characters and letters. Images etc. are printed.

Further, as shown in FIG. 4, when the ejection is recovered, the platen belt 21 is rotated by the drive motor 39 and the opening 21a is moved to a position facing the nozzle surface of the print head unit 10. Next, the drive motor 36 moves the print head recovery unit 30A upward, and the print head recovery unit 30A is capped in close contact with the nozzle surface of the print head unit 10 via the opening 21a of the platen belt 21. The head capping causes the ink to pass through the tube 37 and the suction pump 38.
The suction recovery operation of the nozzle surface is performed.
Further, it is possible to protect the nozzle surface by preventing subsequent drying of the nozzle row.

In the second embodiment, as in the first embodiment, not only the entire apparatus can be made compact, but also the print head recovery unit 30 moves by the thickness of the platen belt 21 by one sheet, and the ejection is performed. The recovery process can be performed, the movable amount of the print head recovery unit 30 can be minimized with a simple structure, and the responsiveness of the ejection recovery operation can be improved.

Next, a third embodiment of the present invention will be described. 5 and 6 relate to a third embodiment of the present invention, and FIG. 5 is an explanatory diagram showing a configuration around a print head unit,
FIG. 6 is an explanatory diagram showing a state during the discharge recovery operation.

In the third mode, the print head unit is moved up and down by a drive motor. As shown in FIG. 5, the print head unit 10A in the third mode is provided with a slider mechanism 35A including a rack and a pinion. Are connected to the drive motor 40. The other basic configuration is the same as that of the first embodiment described above, and the print head recovery unit 30
Is connected to a suction pump 38 via a tube 37, and a drive motor 39 is connected to the roller 22 that drives the platen belt 21.

With such a configuration, during the printing operation, as shown in FIG.
As shown in FIG. 5, the recording medium 2 is supported and conveyed on the platen belt 21 so as to maintain an appropriate distance from the nozzle surface of the print head unit 10, and ink is ejected from the nozzle row of the print head unit 10 to form a character. Images etc. are printed.

Further, as shown in FIG. 6, during ejection recovery, the platen belt 21 is rotated by the drive motor 39 so that the opening 21a moves to a position facing the nozzle surface of the print head unit 10. Next, the drive motor 40 moves the print head unit 10 downward, and the print head recovery unit 30 passes through the opening 21 a of the platen belt 21.
Comes into close contact with the nozzle surface of the print head unit 10 and is sucked by the suction pump 38 through the tube 37,
The nozzle surface of the print head unit 10A can be cleaned.

In the third embodiment, in contrast to the above-described respective embodiments, the ejection recovery process can be performed only by moving the print head unit 10 by the thickness of the platen belt 21, so that the print head recovery unit 30 is fixed. Therefore, the installation space can be minimized, and the entire apparatus can be made more compact.

Next, a fourth embodiment of the present invention will be described. 7 and 8 relate to the fourth embodiment of the present invention, FIG. 7 is an explanatory diagram showing the detection of meandering of a recording medium, and FIG. 8 is a block diagram showing the configuration of a control system.

In the fourth embodiment, the platen belt 21 is rotated to prevent the recording medium 2 from meandering in the printing operation in each of the above-described embodiments. Below, the configuration of the second embodiment will be taken as an example. Although described below, it is needless to say that it may be applied to the first form and the third form.

As shown in FIG. 7, in the fourth embodiment, in addition to the structure of the second embodiment, one sensor 41 for detecting the meandering of the recording medium 2 is provided on each side of the recording medium 2 in the width direction. It has a different configuration. As shown in FIG. 8, the signal from the sensor 41 is input to the control unit 42, and the platen belt 2 is transmitted from the control unit 42 via the drive circuit 43.
The drive motor 39 of No. 1 is controlled.

The control section 42 has two sensors 41 when the recording medium 2 is conveyed on the platen belt 21.
The meandering amount of the recording medium 2 is calculated from the output signal of the drive signal, and the drive motor 39 is controlled via the drive circuit 43 in the direction of suppressing the meandering amount based on the calculation result. As a result, the platen belt 21 is rotated in the direction in which the meandering of the recording medium 2 is suppressed, and the meandering of the recording medium 2 is suppressed. The sensor 41
Is preferably an analog output that can detect the level of the meandering amount, but may be a digital output that detects the upper limit value of the meandering amount of the recording medium 2.

In the fourth embodiment, even if the recording medium 2 meanders with respect to the nozzle area of the print head unit 10, the sensor 41 detects the position of the recording medium 2 in the width direction and the platen belt 21 is moved. Since the recording medium 2 is rotated in the direction orthogonal to the conveying direction, the retracting space of the print head recovery unit 30 at the time of printing is reduced and the entire apparatus is made compact, and meandering of the recording medium 2 is suppressed to be correct. It can be printed in position.

9 and 10 show a modification of the fourth embodiment, and FIG. 9 is a perspective view showing the structure of the platen belt, FIG.
FIG. 10 is an enlarged view of part A of FIG. 9.

As described above, when the platen belt is rotated in the width direction of the recording medium to suppress the meandering, it is desirable that the surface of the platen belt has different characteristics in the conveying direction and the width direction. That is, in the case of the conveyance direction, the recording medium is conveyed by passing through the platen belt by the paper feed roller and the paper discharge roller. Therefore, the surface of the platen belt should have good slippage and high conveyance efficiency. good. On the other hand, in the case of the width direction, since the recording medium moves in the width direction as the platen belt rotates, it is preferable that the surface of the platen bell is less likely to slip.

Therefore, in the platen belt 21 'of the modified example shown in FIGS. 9 and 10, the surface thereof has a mountain-shaped projection cross section in the width direction, and the ridges have the same height along the conveyance direction. A plurality of mountain-shaped portions 21b that continuously form a shape are provided. As a result, the recording medium 2 can be efficiently slid in the conveying direction and can be efficiently conveyed. On the other hand, in the width direction, the tips of the mountain-shaped protrusions act so as to be caught by the recording medium 2. Since it becomes less slippery, the recording medium 2 moves with the rotation of the platen belt 21 ′, and the meandering of the recording medium 2 can be suppressed more effectively.

11 and 12 show another modification of the fourth embodiment. FIG. 11 is a top view of the main parts of the ink jet printer, and FIG. 12 is a side view of FIG.

The distance between the platen belt and the paper feed roller and the distance between the platen belt and the paper discharge roller may be short for reasons such as downsizing of the entire apparatus. In such a case, if the platen belt is rotated in the width direction of the recording medium to suppress the meandering, only a part of the recording medium is moved in the width direction in a short distance, which causes the recording medium to twist. It is thought that there is an adverse effect such as the force being applied and the effect of suppressing the meandering being reduced. If the distance between the platen belt and the paper feed roller and the platen belt and the paper discharge roller is long enough,
Since the force that twists the recording medium is sufficiently small, there is almost no adverse effect, but in order to satisfy the demand for compactness, it is necessary to consider the case where these distances are short.

Therefore, in another modification shown in FIGS. 11 and 12, the paper feed roller 6, the paper discharge roller 7, and the paper feed roll 6 are used.
The drive motor 4 is provided at the respective shaft ends of A and the discharge roll 7A via a gear mechanism 44 for moving in the width direction.
5 in series. Then, when the platen belt 21 is rotated to suppress the meandering of the recording medium 2 in the width direction, the drive motor 45 is rotated in accordance with the rotation of the platen belt 21, and the paper feed roller 6 and the paper discharge roller 7 are rotated. The paper feed roll 6A and the paper discharge roll 7A are moved in the width direction. As a result, the recording medium 2 is rotated in accordance with the rotation of the platen belt 21.
Since the whole is moved in the width direction, no force is applied to the recording medium 2 and it is possible to prevent the meandering suppression effect from being lowered.

[0049]

As described above, according to the present invention, it is not necessary to provide a space for arranging the print head recovery unit at a position retracted at the time of printing, and the entire apparatus can be made compact. Become.

[Brief description of drawings]

FIG. 1 is a perspective view of an essential part of an inkjet printer according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a state during a discharge recovery operation of the same.

FIG. 3 is an explanatory diagram related to a second embodiment of the present invention and showing a configuration around a print head recovery unit.

FIG. 4 is an explanatory diagram showing a state during a discharge recovery operation of the above.

FIG. 5 is an explanatory diagram related to a third embodiment of the present invention and showing a configuration around a print head unit.

FIG. 6 is an explanatory diagram showing a state during a discharge recovery operation of the same as above.

FIG. 7 is an explanatory view related to the fourth embodiment of the invention and showing detection of meandering of a recording medium.

FIG. 8 is a block diagram showing the configuration of the control system of the above.

FIG. 9 is a perspective view showing a configuration of a platen belt according to a modification of the fourth embodiment.

FIG. 10 is an enlarged view of part A of FIG.

FIG. 11 is a top view of essential parts of an inkjet printer according to another modification of the fourth embodiment.

FIG. 12 is a side view of the same as FIG.

[Explanation of symbols]

1 inkjet printer 2 recording media 5 Recording medium transport unit 10 Print head part 20 Platen part 21 Platen Belt 21a opening 30 Print head recovery unit 41 sensor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B65H 5/02 B41J 3/04 102N (72) Inventor Toshihiro Kitahara 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (72) Inventor Hiroshi Hashi 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (72) Inventor Takumi Sugaya 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. F term (reference) 2C056 EA23 EB12 EB36 EC12 EC35 FA02 FA13 HA29 JA06 JA13 JC06 KD10 2C058 AB02 AC07 AC12 AD01 AF31 DA13 3F049 AA03 BA01 BB11 LA07 LB03

Claims (4)

[Claims] 1. A transport unit for transporting a recording medium, a print head unit having a nozzle surface having nozzles for ejecting ink to the recording medium, and a recording medium for receiving ink ejected from the nozzles. A platen portion having a belt, a part of which is located on the back surface side, and a printhead recovery portion arranged to face the nozzle surface of the printhead portion via the belt of the platen portion, An ink jet printer having an opening in a part of the belt, wherein the print head recovery unit seals the nozzle surface through the opening of the belt during the ejection recovery process of the nozzle surface. . 2. The opening portion of the belt moves to a position facing the nozzle surface and the print head recovery portion, the print head recovery portion moves upward, and the nozzle is opened through the opening portion of the belt. The ink jet printer according to claim 1, wherein the surface is hermetically sealed and a discharge recovery process is performed. 3. The nozzle surface moves to a position where the opening portion of the belt faces the nozzle surface and the print head recovery portion, the print head portion moves downward, and the nozzle surface passes through the opening portion of the belt. The ink jet printer according to claim 1, wherein the ink jet printer is sealed and a discharge recovery process is performed. 4. A detection means for detecting the meandering of the recording medium, wherein when the meandering of the recording medium is detected, the belt moves in a direction orthogonal to a conveying direction of the recording medium, The inkjet printer according to claim 1, wherein meandering of the recording medium is suppressed.