JP2001322296A - Ink jet recording device - Google Patents

Abstract

(57) [Problem] To provide an ink jet recording apparatus capable of sealing ink mist generated during a flushing operation and ensuring the reliability of the operation. SOLUTION: In a state where a nozzle forming surface of a recording head 5 is sealed by a capping unit 6, a driving signal irrelevant to printing is given to the recording head to execute a flushing operation for causing ink droplets to be ejected idle. It is configured as follows. Thereby, the ink mist generated by the flushing operation can be effectively sealed.
Therefore, it is possible to solve the problem that the mechanism of the recording apparatus is contaminated by the floating ink mist, thereby hindering the normal operation of the recording apparatus, and the inkjet recording apparatus that can ensure the operation reliability for a long time. Can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus having a recording head for ejecting ink droplets corresponding to print data, and more particularly to a driving signal for the recording head which has no relation to printing. The present invention relates to an ink jet recording apparatus capable of preventing the occurrence of ink mist due to the flushing operation when performing a flushing operation for giving an empty ink droplet.

[0002]

2. Description of the Related Art In general, an ink jet recording apparatus is provided with an ink jet recording head which receives supply of ink from an ink cartridge, and paper feeding means for moving recording paper relatively to the recording head. Recording is performed by ejecting ink droplets on recording paper based on print data while moving in the scanning direction. Since the ink jet recording head described above performs printing by discharging ink pressurized in the pressure generating chamber from the nozzle openings as ink droplets onto recording paper, the ink viscosity increases due to evaporation of the solvent from the nozzle openings and In addition, there is a problem that the nozzle openings are clogged due to solidification of ink, adhesion of dust, and mixing of air bubbles, resulting in poor printing.

For this purpose, this type of ink jet recording apparatus is provided with capping means for sealing the nozzle forming surface of the recording head during non-printing. This capping means not only functions as a lid for preventing ink from drying at the nozzle openings in the print head, but also seals the nozzle forming surface by the capping means when the nozzle openings are clogged, and sucks the ink. The apparatus also has a function of recovering ink droplet ejection capability for sucking and discharging ink from the nozzle openings by negative pressure from the pump to eliminate clogging of the nozzle openings.

The forcible suction / discharge processing of ink for eliminating clogging of the recording head is called a cleaning operation.
This is executed when the user recognizes a printing failure and operates a cleaning switch, for example, and applies a negative pressure by a suction pump to suck and discharge ink from the recording head into the capping means, and then forms the ink using, for example, a rubber material. An operation of wiping the nozzle forming surface is performed by the wiping member.

The recording head also has a function of applying a drive signal unrelated to printing to eject ink droplets. This function is called a flushing operation, and the nozzle of the head is wiped by the wiping member. In order to recover irregular meniscus generated near the opening, and to prevent clogging due to thickening of ink at the nozzle opening where ink droplets are not discharged during printing operation, it is performed at regular intervals. It is configured.

[0006]

In the flushing operation described above, the carriage is generally transferred to a home position, and ink droplets are ejected idly into capping means arranged at the home position. In this case, the ink droplets are controlled to be ejected to the ink absorbing material disposed in the internal space of the capping unit, but a predetermined amount is set between the opening edge of the capping unit and the nozzle forming surface of the recording head. In this state, the ink droplets are idle-discharged at a distance of.

Therefore, depending on the type of ink, the ink droplet ejected from the nozzle opening of the recording head flies directly to the ink absorbing material in the capping means and is not absorbed, but receives air resistance or the like during the flying. At the moment when the ink droplets separate into smaller ink droplets or collide with the surface of the ink absorbing material, a phenomenon that smaller ink droplets, that is, ink mist is generated due to the rebound action has occurred.

When the ink mist is generated as described above, since the ink mist floats in the apparatus, it adheres to, for example, a guide rod for transferring the carriage and contaminates the same, making it difficult to transfer the carriage. There is a problem that the normal operation of the recording apparatus is impaired by contaminating other mechanisms.

An object of the present invention is to solve the technical problem as described above, and to effectively suppress the situation where the ink mist floats due to the flushing operation, and to solve the above-described problem caused by the ink mist. An object of the present invention is to provide an ink jet recording apparatus capable of preventing occurrence of a failure in the recording apparatus.

[0010]

In order to achieve the above-mentioned object, an ink jet recording apparatus according to the present invention comprises: an ink jet recording head for discharging ink droplets corresponding to print data; A capping means for sealing a nozzle forming surface of the head and sucking and discharging ink from the recording head by receiving a negative pressure from a suction pump. In a state in which the nozzle forming surface is sealed, a driving signal irrelevant to printing is given to the recording head to execute a flushing operation for causing ink droplets to be ejected idle.

In this case, preferably, the capping means is formed of a cap member formed of a soft material forming an internal space with the nozzle forming surface, and a hard material holding the cap member. And a sheet-shaped ink absorbing member disposed at the inner bottom of the cap member formed of a soft material.

In a preferred embodiment,
The cap holder is made of a hard synthetic resin, and a columnar rib member rising up at the inner bottom portion of the cap member is integrally formed in advance, and the ink absorbing material is inserted through the rib member and arranged at the inner bottom portion. Is held on the inner bottom by deforming the top of the rib member by heat staking.

Preferably, the ink absorbing member is formed of a single sheet member, and the nozzle forming surface of the recording head in a state where the nozzle forming surface of the recording head is sealed by capping means, and the surface of the ink absorbing member. Are formed such that a gap is formed between them.

According to the ink jet recording apparatus having the above configuration, a drive signal irrelevant to printing is given to the recording head in a state where the nozzle forming surface of the recording head is sealed by the capping means, and the ink droplet is supplied. To perform a flushing operation to discharge
The ink droplets which are ejected by the flushing operation are ejected into the closed space between the nozzle forming surface of the recording head and the capping means.

[0015] Therefore, even if the ink droplets ejected by the flushing operation are changed to ink mist, the ink droplets are sealed in the closed space between the nozzle forming surface and the capping means. Problem can be solved. Most of the ink mist generated in the closed space is absorbed by the ink absorbing material disposed at the inner bottom of the capping means. The amount of floating ink mist can be significantly reduced.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ink jet recording apparatus according to the present invention will be described based on an embodiment shown in the drawings. FIGS. 1 to 3 mainly show the configuration of capping means in an ink jet recording apparatus to which the present invention is applied. FIG. 1 shows a state viewed from the top of the apparatus, and FIGS. 2 and 3 show states viewed from the side, showing a non-capping state and a capping state, respectively.

Reference numeral 1 shown in FIGS. 2 and 3 denotes a carriage. The carriage 1 is configured to be guided by a guide rod 2 and to move in parallel in the longitudinal direction of the paper guide plate 3. . The carriage 1 is connected to a part of a timing belt that is reciprocated by a carriage motor, which will be described later, and is configured to reciprocate along the guide rod 2.

A recording head 5 is mounted on the carriage 1 so as to face the recording paper 4 disposed on the upper surface of the paper guide plate 3. It is configured so that printing can be performed by ejecting ink droplets onto the recording paper 4 on the paper guide plate 3 based on the bitmap data corresponding to the data.

The capping means 6 capable of sealing the nozzle forming surface of the recording head 5 is arranged in a non-printing area (home position) at the end of the recording apparatus. It has a cap member 7 of a size that can be sealed in a sealed space, a function of sealing the nozzle forming surface of the recording head 5 during non-printing to prevent drying of the ink at the nozzle openings, and a suction pump (not shown) during the cleaning operation. And a function for forcibly discharging ink from the recording head 5 by receiving the negative pressure.

Further, the capping means 6 seals the nozzle forming surface of the recording head 5 when the flushing operation for giving a driving signal unrelated to printing to the recording head and causing the ink droplets to be ejected idly is performed. It also has a function as an ink receiver for receiving the ink droplets which are stopped during the flushing operation.

As shown in FIG. 1, an ink discharge port 7a is formed in the inner bottom of the cap member 7 arranged in the capping means 6, and the ink discharge port 7a is provided in a tube pump constituting a suction pump. One end of the tube is connected. Thereby, at the time of non-printing, the nozzle forming surface of the recording head 5 is sealed by the cap member 7,
When a cleaning command is received, negative pressure from the suction pump is applied to the internal space of the capping means, and ink can be forcibly discharged from the recording head 5.

Also, on the inner bottom of the cap member 7,
As will be described later in detail, a sheet-shaped ink absorbing material 8 is accommodated, and the ink sucked and discharged by the cleaning operation can be held thereby. Further, the ink absorbing sheet 8 functions so as to be able to capture and absorb ink droplets ejected from the recording head by a flushing operation.

The cap member 7 is formed integrally with a rectangular cap holder 9 as will be described in detail later.
The flat plate-shaped spring receiving portions 9a are respectively formed in the horizontal direction. The cap holder 9 is mounted on a slider 10 constituting a lifting mechanism, and a pair of compression springs 11 interposed between the slider 10 and a spring receiving portion 9a.
And is attached in a state of being biased toward the recording head 5 side.

An engaging portion 9b is formed at the center of one end of the cap holder 9 and at both sides of the other end, and these three engaging portions 9b are formed on the slider 10 respectively. When the cap holder 9 is locked at three points by the locking member 10a, the movement of the cap holder 9 in the upward direction, that is, toward the recording head 5, is restricted.
Mounted on top.

A pair of long holes 12 are formed on the lower bottom of the slider 10 on the left and right in a substantially horizontal direction, and each of the long holes 12 is rotatably attached to the frame 13. A pair of horizontal shafts 15 arranged on the free end side of the link arm 14 are accommodated so as to be movable. As a result, the slider 10 is linked with the link.
It is possible to stand up with an arc-shaped locus with respect to the frame 13 through the frame 14.

Guide pieces 10b are formed on both sides of the non-printing area side end of the slider 10, and the pair of guide pieces 10b are formed with a pair of guide grooves 16 formed in the frame 13. It is configured to be supported by. The guide groove 16 has a low portion 16a formed at one end, a horizontal high portion 16b formed at the other end,
Further, it is constituted by an inclined portion 16c connecting these, and these three regions are formed to communicate with each other.

Further, as shown in FIG. 1, one end of a tension spring 17 having one end fixed to the frame 13 is fixed to one guide piece 10b.
By the action of 7, the slider 10 is urged so as to be positioned in the print area direction and in the direction away from the recording head 5, that is, in the present embodiment, downward.

Then, as shown in FIG. 2, when the carriage 1 moves just above the capping means 6, the carriage 1
The engaging body 1a disposed on the slider 10 comes into contact with an engaging portion 10c formed to stand upright on the slider 10 so as to resist the tensile force of the spring 17 as shown in FIG.
Rises via the link arm 14, whereby the cap member 7 integrally formed with the cap holder 9 is
The nozzle forming surface of the recording head 5 disposed on the carriage 1 can be sealed.

When the carriage 1 moves to the printing area, the contact of the engaging body 1a on the carriage 1 with the engaging portion 10c arranged on the slider 10 is released, and the slider 10 pulls the spring 17. The state shown in FIG. 2 is restored by the force, whereby the sealing of the nozzle forming surface of the recording head 5 by the cap member 7 is released.

On the other hand, as shown in FIG. 1 or FIG.
A holding member 20 provided with, for example, a rubber wiping member 21 for wiping the nozzle forming surface of the recording head 5 mounted on the carriage 1 with the movement of the carriage 1 is arranged. The holding member 20 is configured to be moved in the horizontal direction so that the wiping member 21 can enter or retract with respect to the wiping position on the moving path of the recording head 5.

Therefore, at the time of cleaning operation, the wiping member 21 of the recording head 5 removes dust, paper dust, and the like adhering to the nozzle forming surface before the ink is sucked, and sucks the ink. Later, the ink adhering to the nozzle forming surface is wiped.

In this case, in the embodiment, the movement of the holding member 20 for holding the wiping member 21 and the pump for sucking the internal space of the capping means to a negative pressure are performed by the recording paper 4 on the paper guide plate 3. The driving force of a paper feed motor (not shown) for transporting the paper is used. Then, the wiping member 21 is configured to advance on the movement locus of the recording head with the driving of the suction pump.

In the above configuration, when the carriage 1 moves to the home position by driving the carriage motor, as shown in FIG. 2, the engaging body 1a arranged on the carriage 1 is changed to the engaging portion 10c formed on the slider 10. Abut. Then, as the carriage 1 still moves in the same direction, the slider 10 stands up through the link arm 14 while resisting the tensile force of the spring 17 as shown in FIG. On the other hand, the guide piece 10b formed on the slider 10
From the low portion 16a of the guide groove 16 to the inclined portion 16
c further moves to a higher level portion 16b, whereby the cap member 7 integrally formed with the cap holder 9 is moved.
Seals the recording head 5 arranged on the carriage 1.

In this manner, when the sealing of the nozzle forming surface by the cap member 7 is completed, the cap member 7 is disconnected from the atmosphere and becomes airtight, thereby suppressing the evaporation of ink from the nozzle openings. Thus, the recording head acts to prevent clogging. Further, by performing the flushing operation in this state, the ink droplets ejected idle from the recording head can be captured by the sheet-shaped ink absorbing material 8 disposed on the inner bottom of the cap member 7. Further, by driving the suction pump in this state, a negative pressure can be applied to the internal space of the cap member 7, and ink can be discharged from the nozzle openings of the recording head.

When the carriage 1 is moved toward the printing area by driving the carriage motor, the engaging member 1a disposed on the carriage 1 is separated from the engaging portion 10c formed on the slider 10. Therefore, the slider 10 is moved through the arm 14 by the tensile force of the spring 17, and the guide piece 10b formed on the slider 10 is moved to the lower part 16a.
The slider 10 moves down by moving to the side a. Thereby, the sealing state of the recording head 5 by the cap member 7 is released.

FIG. 4 is a plan view showing the form of the cap holder 9 and the cap member 7 constituting the above-mentioned capping means. FIGS. 5 and 6 are cross-sectional views as viewed from the line AA in FIG. 4 in the direction of the arrow, and further show a state where the sheet-shaped ink absorbing material is housed and arranged at the inner bottom of the cap member 7. Is shown. 4 to FIG. 6, the already described FIG. 1 to FIG.
The parts corresponding to the respective parts in are denoted by the same reference numerals.

First, as shown in FIG. 4, the cap holder 9 is formed of a hard synthetic resin into a substantially square shape and has an upper part opened, and the opening end face 9c is A pair of spring receiving portions 9a formed in a horizontal state
Is formed substantially flush with the upper surface of the. The opening end face 9 c is formed in an annular shape along the outer periphery of the cap holder 9. A cylindrical rib member 9g is formed integrally from the inner bottom portion of the cap holder 9 so as to rise upward, and the rib member 9g allows a sheet-like ink absorbing material to be formed as described later. It is configured so that it can be held at the bottom.

On the other hand, as shown in FIGS. 5 and 6, a cap member 7 made of a soft material, for example, an elastomer is integrally formed on the cap holder 9 by, for example, a two-color molding method. Is molded.
The upper end edge of the cap member 7 is formed to have a substantially triangular cross section, and is formed so as to protrude upward from the opening end face 9 c of the cap holder 9. With this configuration, the upper edge of the cap member 7 forms a seal portion with respect to the nozzle forming surface of the recording head, and the degree of adhesion at the seal portion is improved so that the sealed state of the internal space in the capping means can be maintained well. It has been done.

As shown in FIG. 5, a sheet-shaped ink absorbing material 8 is accommodated in the inner bottom of the cap member 7 formed of an elastomer. In this case, the ink absorbing member 8 has a cylindrical rib member 9g.
A through hole is formed in advance at a position corresponding to, and the rib member 9g passes through the through hole formed in the ink absorbing material 8 and is stored in the inner bottom. Then, a heat chip (not shown) is pressed against the top of the rib member 9g from the direction indicated by the arrow B in FIG. As a result, a synthetic resin rib member 9g integrally formed with the cap holder 9 is formed.
Is melted and, as shown in FIG. 6, the top is crushed by heat staking to act to hold the ink absorbing material 8 at the inner bottom.

With this configuration, when the nozzle forming surface of the recording head 5 is sealed by the capping means, the space between the nozzle forming surface of the recording head 5 and the surface of the ink absorbing material 8 is shown in FIG. Thus, a predetermined gap h is formed. In this embodiment, the size of the gap h is formed to be about 3 mm.

FIG. 7 shows an example of a control circuit for executing a flushing operation or the like using the capping means having the above-described configuration. In FIG. 7, the parts corresponding to the parts already described are denoted by the same reference numerals, and the description thereof will be omitted. As shown in FIG. 7, a black ink cartridge 31 and a color ink cartridge 32 are detachably mounted on the carriage 1, and each ink is supplied to the recording head 5 from these cartridges. Have been. The carriage 1 receives the driving force of the carriage motor 33 and acts to reciprocate in the main scanning direction.

The discharge side of a tube pump 34 serving as a suction pump capable of sucking the internal space of the capping means 6 to a negative pressure is located at a waste liquid absorbing material 36 housed in a waste liquid tank 35. With this configuration, the ink waste liquid discharged into the capping means 6 by the cleaning operation and the flushing operation is removed by the waste liquid absorbing material 36.
It is configured so that it can be disposed of.

Reference numeral 40 shown in FIG. 7 indicates a host computer. The host computer 40 has a printer driver 41 mounted thereon. Then, on the utility of the printer driver 41, a known paper size, selection of monochrome / color printing, selection of a recording mode, data such as fonts, a print command, and the like are input by the input device 42.

The print data is sent from the printer driver 41 to the print control means 43 mounted on the recording device in response to the input of the print command in the input device 42. The print control unit 43 generates dot pattern data (bitmap data) based on the print data transferred from the host computer 41, and generates a drive signal by the head drive unit 44 based on the data. It has a function of ejecting ink droplets from the recording head 5.

The head drive unit 44 receives a flushing command signal from the flushing control unit 45 and outputs a drive signal for a flushing operation to the recording head 5 in addition to a drive signal based on print data. It is also configured to be able to perform idle discharge of unrelated ink droplets. Reference numeral 46 denotes cleaning control means. The cleaning control means 46 has a function of receiving a control signal from the cleaning command detection means 47, controlling the pump driving means 48, and driving the suction pump 33.

Reference numeral 49 denotes a cleaning command switch disposed on an operation panel or the like of the apparatus. When the user recognizes a printing failure state, for example, operates the switch by operating the cleaning command switch. The cleaning control unit 46 is operated to perform a manual cleaning operation.

On the other hand, a control signal is also sent from the print control means 43 to the carriage motor control means 50, whereby the carriage motor 3
3 is driven. Further, a control signal is also sent from the printing control means 43 to the paper feeding means 51, whereby the recording paper 4 placed on the paper guide member 3 is moved in the scanning direction of the recording head 7. Is controlled so as to be transported in the sub-scanning direction orthogonal to.

When the flushing operation is performed by the flushing control means, the printing control means 4
3 sends a control signal to the carriage motor control means 50. Based on this, the carriage 1 is moved to the home position, and as shown in FIG.
Is sealed by capping means 6. FIG. 6 shows a partially enlarged sectional view in this case.
In this state, the flushing control means 45 operates to eject ink droplets from the nozzle openings of the recording head 5. In addition,
When flushing is performed, the nozzle forming surface of the recording head 5 is
In this case, the tube constituting the tube pump connected to the capping means 6 is in a state of being connected to the atmosphere (normally open), so that the nozzle forming surface is sealed. The ink droplets can be ejected idly into the stopped capping means without any trouble.

In this case, a predetermined gap h (3 mm in the embodiment) is formed between the nozzle forming surface of the recording head 5 and the surface of the ink absorbing material 8 as shown in FIG. Therefore, it is possible to reduce the degree to which the ink droplets ejected from the recording head 5 rebound on the surface of the ink absorbing material 8 and return to the nozzle openings of the recording head 5 to cause color mixture. Further, the degree of occurrence of obstacles such as destruction of the meniscus formed at the nozzle opening due to the rebound of ink droplets can be significantly reduced.

In the flushing operation, since the nozzle forming surface of the recording head 5 is sealed by the capping means 6 as described above, even if ink mist is generated in the space, the mist is generated. Most of them do not leak, and most of them fall to the surface of the ink absorbing material 8 and are captured. Thus, when the capping unit 6 is unsealed from the recording head 5, the amount of ink mist floating outside can be reduced significantly.

[0051]

As is apparent from the above description, according to the ink jet recording apparatus of the present invention, when the nozzle forming surface of the recording head is sealed by the capping means, the printing is not related to the recording head. Since the flushing operation for causing the ink droplets to be ejected in an idle manner is performed by giving a drive signal without any noise, the sunk mist generated by the flushing operation can be effectively sealed. Therefore, it is possible to solve the problem that the mechanism of the recording apparatus is contaminated by the floating ink mist, thereby hindering the normal operation of the recording apparatus, and the inkjet recording apparatus that can ensure the operation reliability for a long time. Can be provided.

[Brief description of the drawings]

FIG. 1 is a plan view mainly showing a configuration of capping means in an ink jet recording apparatus to which the present invention is applied.

FIG. 2 is a side view showing the configuration of the capping means shown in FIG.

FIG. 3 is a side view illustrating a state in which the recording head is capped by the capping unit illustrated in FIG. 1;

FIG. 4 is a plan view showing a configuration in which a cap member is formed on a cap holder constituting the capping means.

FIG. 5 is a cross-sectional view showing a state in which an ink absorbing material is accommodated when viewed in a direction indicated by an arrow from line AA in FIG.

6 is a cross-sectional view showing a configuration in which the ink absorbing material is further held by heat staking in the state shown in FIG. 5;

FIG. 7 is a block diagram showing a configuration of a control circuit mounted on the recording apparatus according to the present invention and for executing a flushing operation and the like.

[Explanation of symbols]

 Reference Signs List 1 carriage 2 guide rod 3 paper guide plate 4 recording paper 5 recording head 6 capping means 7 cap member 7a ink discharge port 8 ink absorbing material 9 cap holder 9g rib member 21 wiping member 31 black ink cartridge 32 color ink cartridge 33 carriage motor 34 Suction pump 40 Host computer 41 Printer driver 42 Input device 43 Printing control means 44 Head driving means 45 Flushing control means 46 Cleaning control means 48 Pump driving means 50 Carriage motor control means 51 Paper feed means

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 2C056 EA14 EA16 EC11 EC23 EC24 EC34 EC54 EC57 FA10 HA56 JA04 JA08 JA10 JA13 JA17 JB04 JC08 JC13 JC20 JC23

Claims (4)

[Claims] An ink jet recording head for ejecting ink droplets corresponding to print data; a nozzle forming surface of the recording head being sealed; An ink jet recording apparatus comprising: a capping unit that sucks and discharges ink; and a drive signal that is not related to printing with respect to the recording head in a state where the nozzle forming surface of the recording head is sealed by the capping unit. And an ink jet recording apparatus configured to execute a flushing operation for causing ink droplets to be ejected by idle. A cap member formed of a soft material forming an internal space between the cap member and the nozzle forming surface; and a cap holder formed of a hard material holding the cap member. 2. The ink jet recording apparatus according to claim 1, further comprising: a sheet-shaped ink absorbing member disposed at an inner bottom of the cap member formed of a soft material. 3. The cap holder is made of a hard synthetic resin, and a columnar rib member rising on an inner bottom portion of the cap member is integrally formed in advance, and is inserted into the rib member and arranged on the inner bottom portion. 3. The ink jet recording apparatus according to claim 2, wherein the ink absorbing material is held on the inner bottom by deforming the top of the rib member by heat staking. 4. A method according to claim 1, wherein the ink absorbing member is formed of one sheet member, and the nozzle forming surface of the recording head and the surface of the ink absorbing member in a state where the nozzle forming surface of the recording head is sealed by capping means. 4. The ink jet recording apparatus according to claim 1, wherein a gap is formed between the ink jet recording apparatuses.