JPH08150722A - Image forming apparatus - Google Patents

Abstract

PURPOSE: To keep the recovery function of a recovery means and the stable emission of a recording head by suppressing the formation of a precipitate caused by the drying of the ink bonded to the recovery means. CONSTITUTION: A cap 101 having an ink absorbing element 103 provided therein is attached to a holder 102. The cap 101 closes the emitting orifice surface of a recording head 11 at the time of non-recording hermetically to prevent the drying of the ink in the recording head 11. If necessary, ink is forcibly extruded to the absorbing element 103 from the recording head 11. A liquid supply port 106 to which a washing soln. is supplied and a suction port 107 sucking the air or liquid in the cap 101 are opened to the interior of the cap 101. The washing soln. is supplied from the liquid supply port 106 to be sucked from the suction port 107 to wash off the contaminant in the absorbing element 103 and the cap 101.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming an image on a recording medium, and more particularly to an image forming apparatus using an ink jet recording head for ejecting a liquid such as ink to form an image.

[0002]

2. Description of the Related Art A copying machine, printer, or the like, which is used together with a computer, a word processor, or the like, or is used alone.
An image forming apparatus such as a facsimile includes a recording head that forms an image on a recording medium such as a sheet based on an image signal. Further, the image forming apparatus is roughly classified into a serial type and a line type depending on the scanning system of the recording head. On the other hand, as the material of the recording medium, in recent years, in addition to paper which is a normal recording medium and resin thin plates such as OHP sheets, thin paper, paper with punch holes for filing, paper with perforations, etc. It has been required to use processed paper such as shaped paper or woven cloth. Also, regarding the size of the recording medium, a large size sheet is required for a sheet for advertisement and a woven cloth used for clothes and the like.

As described above, as a typical image forming apparatus capable of performing recording on various recording media, there is an image forming apparatus using an ink jet recording head for recording by ejecting ink from ejection ports. . In a serial type image forming apparatus in which an inkjet recording head is scanned in a direction intersecting a recording medium conveyance direction,
After the recording medium is set at a predetermined position, the scanning of the inkjet recording head while ejecting ink and the conveyance of the recording medium at a predetermined pitch are repeated based on the image signal, so that the image recording on the entire recording medium is performed. Done. Also,
In a full-line type image forming apparatus in which an inkjet recording head that covers the entire width of the recording medium is fixed on the recording medium conveying unit, the recording medium is conveyed at a position facing the ejection port surface where the ejection port of the inkjet recording head is formed. At this time, ink is ejected from the recording head based on the image signal and recording is performed on the entire surface of the recording medium only by conveying the recording medium.

In such an image forming apparatus using an ink jet recording head, the ink viscosity increases due to the evaporation of the water content of the ink in the ejection port, and the ink is gradually clogged, so that stable ink ejection is achieved. Therefore, recovery means is provided for maintaining stable ejection of ink. As a recovery means, there is provided a cap means for capping the ejection opening surface of the ink jet recording head during non-recording to suppress thickening of ink, or if necessary, ink is ejected separately from recording to increase viscosity. It is known that a preliminary ejection means for removing ink is provided. Further, even if the recording head is capped by the cap means, the thickening of the ink progresses at a slow rate.Therefore, the ink is pressure-fed to the recording head as necessary, and the ink is forced out into the cap means. ing. For this reason, the cap means and the preliminary ejection means are provided with absorbers that absorb the thickened ink discharged from the recording head, and the absorbers absorb the ink ejected or pushed out from the recording head.

Further, Japanese Laid-Open Patent Publication No. 6-71897 discloses an inkjet recording head for cleaning the ink adhering to the ejection port surface by jetting a cleaning liquid from the outside.

[0006]

However, in the above-mentioned conventional image forming apparatus, when the ejection port surface of the ink jet recording head is capped by the cap device material, the ink adhering to the ejection port surface adheres to the cap device. Will end up. Therefore, when a specific ink is used or left in this state for a long time, the ink attached to the cap means evaporates the moisture contained in the ink due to the change in the chemical properties of the ink over time. Along with this, the dye is deposited as a main component and further deposited. As a result, when the inkjet recording head is capped again, the deposit may adhere to the periphery of the inkjet recording head, block the inside of the ejection port, or block the opening of the cap unit. Further, the deposit itself becomes a nucleus and causes dust and dirt in the atmosphere to adhere to the cap means, and promotes the contamination of the cap means.

The same thing can be said for the absorber in the cap means and the absorber of the preliminary ejection means. That is, with the evaporation of the water content of the ink absorbed by the absorber,
The dye deposits on the absorber, and the deposit impairs the ink absorbing function. Such dirt on the recovery means deteriorates the recovery function of the inkjet recording head, and further causes dirt on the recovery means to adhere to the recording head, resulting in failure to maintain stable ejection of ink.

Further, even if the cleaning liquid is sprayed to clean the ink adhering to the ejection port surface, the recovery means is not cleaned only by cleaning the ink jet recording head. It could not be prevented, and there was a problem as described above.

Therefore, an object of the present invention is to provide an image forming apparatus that maintains the recovery function of the recovery means and stable ejection of the recording head by suppressing the formation of precipitates due to the drying of the ink adhering to the recovery means. And

[0010]

In order to achieve the above-mentioned object, an image forming apparatus of the present invention is provided with a recording head for ejecting ink from an ejection port, and the recording head is arranged outside the recording area by the recording head, and the recording is performed at the time of non-recording. An image having a cap member that seals the surface of the head on which the ejection port is formed, and an absorber that is provided inside the cap member and that absorbs the ink that is forcedly pushed out from the recording head when necessary. The forming apparatus includes a cleaning liquid supply unit that supplies a cleaning liquid into the cap member, and a suction unit that sucks and discharges the liquid in the cap member.

Further, the cap member may be provided with a communicating means for communicating the inside and the outside of the cap member. In this case, the communicating means may be arbitrarily opened and closed. The opening and closing means may be connected.

Further, a receiving portion that is formed around the cap member and receives the liquid at a position lower than a contact portion of the cap member with the recording head, and a discharging means that discharges the liquid in the receiving portion. In this case, one end is located outside the cap member in the vicinity of the contact portion of the cap member with the recording head, and the other end is in the receiving portion. A second absorbent body that absorbs the liquid and that is arranged so as to be immersed in the received liquid may be provided.

A recording head for ejecting ink from an ejection port, and a recording head disposed outside the recording area of the recording head,
In an image forming apparatus having, inside, a preliminary ejection portion provided with an absorber that absorbs ink ejected separately from recording from the recording head, if necessary, the absorber is
A cleaning liquid supply unit that is provided in a storage unit that stores a liquid, and that supplies a cleaning liquid into the storage unit, and a discharge unit that discharges the liquid stored in the storage unit may be provided, and further, The cleaning liquid supply means and the discharge means may be provided at positions facing each other with the absorber interposed therebetween.

Further, the recording head may be provided with an electrothermal converter for generating thermal energy used for ejecting ink, and in particular, it is applied by the electrothermal converter. Thermal energy
The film may be ejected from the ejection port by utilizing the film boiling generated in the ink.

[0015]

In the image forming apparatus of the present invention constructed as described above, which has the cap member inside which the absorber is provided, in the non-recording, the surface of the recording head on which the ejection port is formed is the cap member. Sealed by (capping)
This prevents the ink in the ejection port from drying. Also, if necessary, force the ink out of the recording head,
The thickened ink in the ejection port is discharged to the absorber. Due to such capping of the recording head by the cap member and forced ejection of the ink from the recording head, ink adheres to the contact portion of the cap member with the recording head and the absorber, and becomes dirty.

Here, when the cleaning liquid is supplied to the absorber by the cleaning liquid supply means in a state where the capping by the cap member is released, the cleaning liquid is absorbed in the absorber and the concentration of the ink absorbed in the absorber is diluted. Further, if the supply amount of the cleaning liquid is set to be approximately the same as the internal volume of the cap member, the concentration of the ink attached inside the cap member, including the contact portion of the cap member with the recording head, is also reduced.
Then, by sucking the liquid in the cap member to the outside by the suction means, the ink absorbed in the absorber and the ink adhering to the inside of the cap member are discharged together with the cleaning liquid, and as a result, the absorber and the cap member are removed. To be washed.

Further, by providing the cap member with a communication means for communicating the inside and the outside of the cap member,
During capping of the recording head by the cap member, the pressure in the space formed by the cap member and the recording head is kept constant, and backflow of air or liquid in the cap member to the ejection port of the recording head is prevented. Particularly, in the case where the opening / closing means for arbitrarily opening / closing the connecting means is connected to the connecting means, the opening / closing means closes the connecting means after the capping operation is completed. As a result, the surface of the recording head on which the ejection openings are formed is kept in a sealed state, and the ink inside the ejection openings is prevented from drying.

Further, by forming a receiving portion around the cap member for receiving the liquid at a position lower than the contact surface between the cap member and the recording head, the supply amount of the cleaning liquid from the cleaning liquid supply means can be changed. If the volume is larger than the internal volume, the cleaning liquid overflows from the cap member, so that the outside of the cap member is also cleaned. The cleaning liquid overflowing from the cap member is received by the receiving portion, but since the receiving portion is provided with the discharging means for discharging the liquid in the receiving portion, the liquid does not overflow from the receiving portion.

In this case, by further providing a second absorber for absorbing the liquid on the outside of the cap member, when the ink forcedly pushed out from the recording head comes off the outside of the cap member, the ink Is absorbed. Since the other end of the second absorbent body is immersed in the liquid received in the receiving section, due to the head difference generated in the second absorbent body,
The ink absorbed by the second absorber is guided to the receiving portion, and the stain on the outside of the cap member due to the ink is suppressed. Further, when the second absorbent body is heavily soiled, when the cleaning solution supplied from the cleaning solution supply means overflows from the cap member, a flow of the cleaning solution is formed due to the head difference, and the second absorbent body is cleaned.

On the other hand, in the case of the one having the preliminary discharge part in which the absorber is provided, the absorber is provided in the storage part, and the cleaning liquid is supplied to the storage part by the cleaning liquid supply means, while the cleaning liquid is supplied to the storage part. The liquid in the reservoir is discharged. As a result, the absorber in the preliminary ejection portion is cleaned, as in the case of the cap member described above.

In this case, by providing the cleaning liquid supply means and the discharge means at positions facing each other with the absorber interposed, the cleaning liquid supplied from the cleaning liquid supply means is always discharged from the discharge means through the absorber. Therefore, the cleaning of the absorber is effectively performed.

[0022]

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

(First Embodiment) FIG. 1 is a schematic perspective view of an embodiment of the image forming apparatus of the present invention, and FIG. 2 is a main sectional view of the image forming apparatus shown in FIG.

The image forming apparatus of this embodiment discharges ink downward, and the printer unit 1 for recording an image on the recording medium A and the recording medium A are intermittently moved by a predetermined amount (recording length L). It has the conveyance part 2 which conveys. The recording medium A is a cloth, which is wound and held in a roll shape on the feeding unit 3 and is conveyed by the conveying unit 2 to the printer unit 1. Also,
The recording medium A printed by the printer unit 1 has a drying unit 5
After being dried in, it is wound around the winding unit 4.

The printer unit 1 includes two scanning rails 1
a and 1b are supported in a direction perpendicular to the transport direction of the recording medium A. On these two scanning rails 1a and 1b, a carriage 10 carrying a total of 16 recording heads 11 is slidably supported, eight on the upstream side and eight on the downstream side in the transport direction of the recording medium A, respectively. And the carriage 1
0 is reciprocally scanned in the directions of arrows P1 and P2 by a drive source (not shown). Recording is performed in the range of the recording length L × width of the recording medium A by the recording head 11 by one scanning of the carriage 10, and intermittent recording is performed by each scanning, so that continuous recording is performed. Recording is sequentially performed on the medium A. The recording method is as follows. The image data is recorded by allocating 50% of the data to the recording head 11 on the upstream side and the recording head 11 on the downstream side in the conveyance direction of the recording medium A, and recording images on both sides are overlapped. It is matched. That is, 50% of the image data is recorded by the upstream recording head 11, the recording medium A is intermittently fed, and then the remaining 50% of the image data is recorded by the downstream recording head 11.

As the recording head 11, an ink jet recording type recording head for ejecting ink for recording is used. Recording medium A of each recording head 11
The eight recording heads 11 arranged on the same side with respect to the conveyance direction of the nozzles eject eight colors of ink having different hues, saturations, and lightnesses, and eight inks of different colors are stored. Ink of different colors is supplied from an ink supply device having an ink tank through a tube by a supply pump (not shown) provided for each ink tank. Ink of the same color is supplied to the downstream recording head 11 at a position corresponding to the upstream recording head 11. At the time of recording, ink is automatically supplied to the recording head by the amount of the ink ejected from the recording head 11 due to the capillary action.

The internal structure of the recording head 11 will be described with reference to FIG. The recording element head has a plurality of ejection openings 1001 formed at a predetermined pitch on an ejection opening surface 1006 facing the recording medium A. In addition, each discharge port 1
Reference numeral 001 denotes the common liquid chamber 10 via the liquid passages 1002.
It is in communication with 03. An electrode 100 is provided in each liquid path 1002.
An energy generating unit 1004 that generates energy for ejecting ink when a voltage is applied through 5 is provided. The common liquid chamber 1003 communicates with the above-described ink tank, and ink is supplied from the ink tank to the common liquid chamber 1003. The ink supplied from the ink tank to the common liquid chamber 1003 and temporarily stored therein enters the liquid passage 1002 by a capillary phenomenon, forms a meniscus at the ejection port 1001, and keeps the liquid passage 1002 filled. In this state, the energy generating means 10
When 04 is energized, ink is ejected from the ejection port 1001 by the energy generated by the energy generating means 1004.

The energy generating means 1004 irradiates an electromechanical converter such as a piezo element that generates mechanical energy for instantaneously applying ejection pressure, or an electromagnetic wave such as a laser to generate heat, and the generated heat causes ink to be generated. There is a method of ejecting ink, a method of giving thermal energy to ink by an electrothermal converter such as a heating element having a heating resistor, and ejecting ink by the thermal energy.

Among them, in the case of ejecting ink by thermal energy, since the ejection openings 1001 can be arranged at a high density, it is possible to perform high resolution recording. In particular, in the case where the electrothermal converter is used as the energy generating means 1004, the energy generating means 1004 can be manufactured by using the semiconductor manufacturing process.
Compact size is easy, and the advantages of IC technology and microfabrication technology, which have been remarkably improved in technology and reliability in the recent semiconductor field, can be fully utilized, high-density mounting is easy, and manufacturing cost is high. Can also be cheap.

Referring again to FIGS. 1 and 2, the image forming apparatus of this embodiment will be described. A recovery device 20 is provided outside the range of the reciprocating motion of the printer unit 1 in the recording operation in order to maintain good ejection characteristics of the recording head 11. The recovery device 20 includes a cap unit 100, a blade unit 200, a preliminary discharge unit 300, and a tank unit 400.
And a pump unit 500 and a discharge unit 600. These units will be described in detail below.

(1) Cap portion 100 If the ejection port surface 1006 of the recording head is left exposed in the air, the water content of the ink in the liquid passage 1002 of the recording head 11 evaporates, the viscosity increases, and the ejection is performed. Becomes unstable. The cap portion 100 is for preventing this,
It has a function of capping the ejection port surface 1006 during non-recording. In addition, when the standing time is long, the ink in the liquid path 1002 thickens due to evaporation of water even though capping is performed. Furthermore, the liquid path 10
The bubbles dissolved in the ink in 02 and in the common liquid chamber 1003 may become large and hinder stable ejection. Therefore, while the ejection port surface 1006 is capped, the supply pump in the above-described ink supply device 13 is driven to press the ink from the ink tank to the recording head 11 to force the thickened ink or bubbles from the ejection port 1001. The cap portion 100 also has a function of pushing it to the outside.

FIG. 4 is an enlarged perspective view of the cap portion of the image forming apparatus shown in FIG. The cap unit 100 is provided for the recording head 11 at the home position of the carriage 10.
Are provided facing each other, and as shown in FIG.
16 holders 10 corresponding to the position of each recording head 11
2 has a fixed support plate 111. A cap 101 as a cap member for capping the recording head 11 is provided in each holder 102. The support plate 111 is supported by two side plates 114 provided with guide rails 112 so as to be vertically movable. Each side plate 114 has a support plate 11
1, an air cylinder 113 for moving up and down 1 is attached, and by driving the air cylinder 113, the support plate 1
By moving 11 upward, the ejection port surface 1006 of each recording head 11 is capped by the cap 101. Each cap 101 is
The recording head 11 is made of a rubber-like elastic member such as fluorine, silicone, and chlorinated butyl, and is used for capping.
Improves adhesion and airtightness with.

FIG. 5 is a sectional view in the X direction (longitudinal direction of the holder 102) in the vicinity of the holder of the cap portion 20 shown in FIG. 4, and FIG. 6 is a sectional view in the Y direction (in the lateral direction of the holder 102) also in the vicinity of the holder. It is a diagram, and each is shown in a state in which the recording head 11 is capped.

As shown in FIGS. 5 and 6, the cap 1
01 is attached to the cap attachment portion 102a of the holder 102. Inside the cap 101, an absorbent body 103 made of a porous body such as urethane foam, a sintered body, and a fiber net is provided.
Is provided. The absorber 103 is attached to the holder 102 and forms a gap D with the recording head 11 during capping. The absorber 103 holds a liquid, which maintains the inside of the cap 101 at a high humidity and suppresses the evaporation of the moisture of the ink in the recording head 11, thereby minimizing the thickening of the ink. . Absorber 10
The liquid held in 3 is the ink pushed out from the ejection port 1001 by the pressure feed of the ink from the above-mentioned ink tank, and the cleaning liquid for cleaning the inside of the cap 101. In addition, the ink absorber 103 is made of the ink ejected from the ejection port 1001 when the ink is pressure-fed, and the ejection port surface 100
Ink droplets adhering to 6 are sucked from the ejection port surface 1006 and quickly moved into the cap 101.

Around the cap mounting portion 102a of the holder 102, a receiving portion 104 for receiving the liquid is formed at a position lower than the cap 101. The receiving unit 104 is
Ink, cleaning liquid, or a mixed liquid of these liquids has a constant liquid level H
1 is maintained and stored. The liquid that exceeds the liquid level H1 is
The liquid is discharged to the liquid collecting member 105 via the drain 102b provided at the end of the holder 102. The liquid collecting member 105 is
The liquid from each holder 102 is collected, and the liquid is caused to flow from the discharge pipe 105a serving as a discharge unit for discharging the liquid in the receiving unit 104 to the discharge unit 600 (see FIG. 1). The tip 102c of the drain 102b has a convex portion with an acute angle, guides the liquid flowing through the drain 102b to the liquid collecting member 105, and prevents the liquid from wrapping around the drain 102b due to the surface tension of the liquid.

Cap mounting portion 102a of holder 102
A liquid supply port 106, a suction port 107, and a communication port 108 are opened on the surface on which the absorber 103 is attached.

The liquid supply port 106 is for supplying the cleaning liquid to the inside of the cap 101, and the joint 106.
It is connected to the tank portion 400 (see FIG. 1) by a, and the cleaning liquid is supplied via the electromagnetic valve 402. That is, the liquid supply port 106 and the tank portion 400 constitute a cleaning liquid supply unit that supplies the cleaning liquid into the cap member.

The suction port 107 is for leading out the liquid inside the cap 101 to the outside, and the joint 1
07a is connected to the pump unit 500 (see FIG. 1),
The liquid in the cap 101 is sucked by the operation of the pump unit 500. That is, the suction port 107 and the pump unit 500 constitute a suction unit that sucks and discharges the liquid in the cap member.

The communication port 108 serves as a communication means for communicating the inside and the outside of the cap 101,
It is connected to the discharge part 600 (see FIG. 1) by the joint 108a. The pipe connecting the communication port 108 and the discharge part 600 is provided with an electromagnetic valve 109 as an opening / closing means for arbitrarily opening / closing the communication means. The electromagnetic valve 109 is opened when the cap 101 caps the recording head 11, and the air and liquid in the cap 101 are discharged from the discharge portion 600.
Missed by. This allows capping with capping 10.
The pressure rise in the cap 101 due to the compression of No. 1 is suppressed, and the air and the liquid in the cap 101 are prevented from flowing back to the ejection port 1001 of the recording head 11.
After the capping is completed, the electromagnetic valve 109 is closed to keep the cap 101 in a hermetically sealed state.

As described above, the connection between the liquid supply port 106 and the tank portion 400, the connection between the suction port 107 and the pump portion 500, and the connection between the communication port 108 and the discharge portion 600 are joints 106a and 107a, respectively. Since the holder 102 is replaced with the holder 108, the holder 102 can be easily replaced by disconnecting the joints 106a, 107a, and 108a when the holder 102 is replaced.

Further, as shown in FIG.
1, one end portion (upper end portion) is located near the contact portion of the cap 101 with the recording head 11, and the other end portion (lower end portion) is in a position where it is immersed in the liquid stored in the receiving portion 104. An absorber 110 that is a second absorber is provided.

Next, the operation of the capping unit 100 will be described.

At the start of recording and at every predetermined number of reciprocations during recording (usually every 50 to 100 reciprocations), ink is pressure-fed to the recording head 11 separately from recording, and the thickened ink in the recording head 11 is pushed out. . As shown in FIG. 7, the ink is fed under pressure with the recording head 11 facing the cap 101, and the two are separated from each other.
Drive the supply pump (see) to remove the thickened ink and residual bubbles inside the ejection port 1001 from the ejection port 1001.
It is discharged to 1. This also has an effect of washing out dust and the like to maintain stable discharge even if dust or the like adheres to the surface of the discharge port 1001 or dust or the like enters the discharge port 1001.

After the ink is fed under pressure, most of the ink droplets 1010 formed on the ejection port surface 1006 fall by its own weight and are absorbed by the absorber 103, but some of them are ejected together with the small ink droplets 1006. Remains attached to. Therefore, as shown in FIG. 6, the recording head 11 is once capped by the cap 101, and the ink adhered to the ejection port surface 1006 is absorbed by the absorber 103. This operation is particularly necessary when an ink having a low surface tension and a high wettability with the ejection port surface 1006 is used, and it may not be intentionally performed because the time is shortened depending on the physical properties of the ink used. The operation of the solenoid valve 109 when capping is as described above.

After the above operation, as shown in FIG. 8, the capping by the cap 101 is released, and the recording head 1
1 is moved in the direction of arrow P1 and positioned on the blade portion 200 (see FIG. 1). At the same time, in the cap 101, an operation for cleaning the absorber 103 that has absorbed the ink pushed out by the pressure feeding of the ink is performed. That is, the solenoid valve 402 (see FIG. 5) is opened, and the tank unit 4
00 (see FIG. 1) is supplied to the inside of the cap 101 from below through the liquid supply port 106. As the type of cleaning liquid, a liquid used as an ink solvent, pure water, a colorless clear ink having the same chemical composition as the used ink and containing no dye, and the like are suitable.

The supply amount of the cleaning liquid varies depending on the degree of contamination of the cap 101, and is roughly classified into the following two.

The recording head 11 is short and the ejection port 1001
Is small, the amount of ink discharged from the ejection port 1001 is small, or the surface tension of the ink used is high,
When the wettability with the cap 101 is low, the amount of the cleaning liquid to be supplied is set to the same level as the internal volume of the cap 101,
The inner wall surface of the cap 101 is washed.

On the contrary, when the recording head 11 is long and the number of ejection ports 1001 is large, and a large amount of ink is ejected from the ejection ports 1001, or the surface tension of the ink used is low, it is When the wettability of is high,
The amount of the cleaning liquid to be supplied is made equal to or larger than the internal volume of the cap 101, so that the cleaning liquid overflows from the cap 101.
The contact portion of No. 01 with the recording head 11 and the outer peripheral portion are also cleaned.

From the viewpoint of the consumption amount of the cleaning liquid, it is desirable that the amount is as small as possible, so that the large amount is used as necessary. For example, since the recording head 11 and the cap 101 are in a one-to-one correspondence, the supply amount of the cleaning liquid may be increased with respect to the recording head 11 using a specific ink.

After the cleaning liquid is supplied, the liquid in the cap 101 and the absorber 10 are pumped by the pump unit 500 (see FIG. 1).
The liquid sucked into 3 is sucked from the suction port 107,
Finally, it is discharged to the discharge section 600. By this suction, the absorber 103 is kept in an appropriate wet state.

The liquid sucked by this suction is a liquid in which the cleaning liquid supplied from the liquid supply port 106 and the ink ejected from the recording head 13 are mixed. By sucking this liquid, the ink is discharged together with the cleaning liquid. Will be discharged. That is, the dye concentration of the ink attached to the cap 101 and the ink absorbed by the absorber 103 is lowered, and as a result, the inner wall of the cap 101 and the absorber 103 are washed. Furthermore, when a large amount of cleaning liquid is supplied as described above, the ink flows out of the cap 101 together with the cleaning liquid, and the cap 1
The outer wall of 01 will also be washed. By cleaning the cap 101 and the absorber 103 in this manner,
Deposition of ink dye on the cap 101 and the absorber 103 is suppressed. Further, even if a precipitate is formed, by supplying the cleaning liquid, the precipitate is dissolved in the cleaning liquid,
It can be washed off.

Therefore, the deterioration of the recovery function due to the deposit of the deposit on the cap 101 or the absorber 103 and the attachment of the deposit to the recording head 11 due to the capping are suppressed,
Stable ejection of ink from the recording head 11 can be maintained.

On the other hand, the absorber 110 provided on the outside of the cap 101 collects the ink when the ink droplet 1010 shown in FIG. 7 falls and does not fall inside the cap 101. Absorb. Moreover, the lower end portion of the absorber 110 is immersed in the liquid in the receiving portion 104 as described above, and the head difference G generated in the absorber 110.
Then, the ink is guided to the receiving portion 104. Therefore, the deposition of the dye of the ink on the outside of the cap 101, especially near the contact portion with the recording head 11, is prevented. Further, the absorbent body 110 guides the cleaning solution together with the ink to the receiving portion 104 by the water head difference G even when the cleaning solution is supplied until it overflows from the cap 101.
10 are washed.

(2) Blade portion 200 When the ink mist generated during recording adheres to the ejection port surface 1006 and approaches the ejection port 1001, the ejection becomes unstable. In addition, the ejection port surface 1006 after the above-described ink pressure feeding is performed.
Although the ink droplets are absorbed by the absorber 103 of the cap portion 100, the ink droplets cannot be completely absorbed, which also causes unstable ejection. The blade portion 200 has a discharge port surface 1
006 is wiped (wiping) and cleaned, and the discharge port surface 10
It is intended to prevent instability of ejection due to adhesion of ink mist or the like to 06, and is located closer to the recording area than the cap portion 100.

FIG. 9 is a sectional view of the blade portion 200 shown in FIG. As shown in FIG. 9, the blade 201 is fixed to the tip of the holder 202 which is rotated in the arrow direction around the fulcrum 202a. Blade 201
Is made of a porous material similar to the absorbent body 103 of the cap portion 100, and when the holder 202 is at the position shown by the solid line in FIG.
6 is pressed. That is, the recording head 11 supports the fulcrum 20.
By rotating the holder 202 while being positioned above 2a, the ejection port surface 1006 of the recording head 11 is wiped by the blade 201.

Below the holder 202, the septic tank 203 is arranged. The septic tank 203 is for cleaning the blade 201 after wiping of the recording head 11,
The cleaning liquid appropriately supplied from the tank unit 400 (see FIG. 1) is stored inside. Excess cleaning liquid is drain 20
4 and the discharge portion 600 (see FIG. 1) via the discharge pipe 204a.
(See)). By this drain 204, the liquid level H2 of the septic tank 203 is maintained at a constant height, and after wiping, the holder 202 is rotated and the blade 201 is directed downward, so that the blade 201 is immersed in a certain amount of cleaning liquid,
To be washed.

The wiping operation is always performed after the above-described ink pressure feeding. In addition, it is performed every one round trip of the recording head 11 or every preset number of round trips. In this embodiment, one blade 201 is associated with four recording heads 11,
We are wiping. Further, the blade 201 is connected to the pump unit 500 (see FIG. 1), and the septic tank 20
The cleaning solution absorbed excessively by being immersed in the cleaning solution of No. 3 is sucked by the pump unit 500,
The proper wet state is maintained, and the recording head 11 is wiped well.

(3) Preliminary ejection section 300 When the duty of the recorded image is low, the ejection port 100
Depending on 1, the ink is hardly ejected, and the viscosity of the ink may increase due to the evaporation of the water content of the ink. In order to prevent this, in the preliminary ejection unit 300, a predetermined drive pulse is applied to the recording head 11 before the start of recording to eject ink from all ejection ports 1001 (this is called "preliminary ejection"). ). In addition, by the preliminary ejection, the ink of another color attached to the ejection port 1001 of the other recording head 11 is ejected as droplets by the wiping by the above-described blade portion 200.

FIG. 10 is a sectional view of the preliminary ejection section 300. As shown in FIG. 10, the preliminary ejection unit 300 includes an absorber 301 made of a porous material similar to the absorber 103 of the cap unit 100 for receiving ink droplets ejected from the recording head 11, and an absorber. A holder 302 that holds 301 and a cleaning nozzle 303 that is provided in the holder 302 and discharges the cleaning liquid and that supplies the cleaning liquid into the storage portion 302a are provided.

The holder 302 forms therein a storage portion 302a for holding and storing the cleaning liquid at a constant liquid level height H3, and the excess cleaning liquid is stored in the storage portion 302 by the drain 304.
It is discharged to the discharge part 600 (see FIG. 1) via the discharge pipe 304a as a discharge means for discharging the liquid stored in a. The absorber 301 is soaked in the cleaning liquid in the reservoir 302a to facilitate absorption of the ink droplet 1010 during preliminary ejection. That is, the liquid held in the absorber 301 is the ink droplets 10 ejected from the recording head 11.
10 is trapped to prevent the recording head 11 from bouncing back to prevent the mist from adhering to the recording head 11.
The cleaning nozzle 303 is connected to the tank unit 400 (see FIG. 1) and discharges the cleaning liquid supplied from the tank unit 400 into the storage unit 302a. In addition, the cleaning nozzle 303
Is disposed at a position facing the drain 304 with the absorber 301 interposed therebetween, and discharges the cleaning liquid from the cleaning nozzle 303 so that the cleaning liquid flows in one direction and is stored in the storage section 202.
The contaminated cleaning liquid in a is being washed away. As a result, the absorber 301 is washed and the dye concentration of the ink in the absorber 301 is lowered, so that the dye of the ink is prevented from depositing on the absorber 301, and the ink absorbing ability of the absorber 301 is maintained.

Preliminary ejection is performed by the same ink droplet 101 as that at the time of recording
Since the discharge is 0, the absorber 301 is
The cap 101 absorbs only about 1 / 10,000 of the ink amount received when the ink is pressure-fed at zero. Therefore, the cleaning of the absorber 301 is not normally performed during recording, but is performed at the end of recording.

(4) Tank Section 400 The tank section 400 is for supplying the cleaning liquid to the cap section 100, the blade section 200, and the preliminary discharge section 300. As shown in FIG. 2, the tank 401 for storing the cleaning liquid is located above the printer unit 1, and therefore the tank 401 is located above the cap unit 100, the blade unit 200, and the preliminary ejection unit 300. Tank 4
The solenoid valve 402 is provided in the pipe connecting 01 and the above-mentioned respective parts, and the tank 4 is opened by appropriately opening the solenoid valve 402.
An appropriate amount of the cleaning liquid stored in 01 is supplied to each part by free fall. The cleaning liquid stored in the tank 401 is manufactured by a cleaning liquid manufacturing apparatus (not shown) which is an external device, and the cleaning liquid is supplied to the tank 401 from there.

(5) Pump section 500 The pump section 500 is the absorber 103 of the cap section 100.
(See FIG. 5) and the blade 201 of the blade unit 200.
(See FIG. 9) is for sucking the excessively absorbed ink or cleaning liquid, and is arranged below the cap portion 100 and the blade portion 200. As shown in FIG. 2, the pump unit 500 includes a pump 501, and a suction pipe 50 and a discharge pipe 503 connected to the pump 501, respectively. In FIG. 2, a pump 501,
Although only one set is shown for the suction pipe 502 and the discharge pipe 503, actually two sets are provided, one for the cap part 100 and one for the blade part 200 (see FIG. 11). The suction pipe 502 connected to the pump 501 for the cap unit 100 is the suction port 107 of the cap unit 100.
(See FIG. 5). The suction pipe 502 connected to the pump 501 for the blade part 200 is connected to the blade 201 (see FIG. 9) of the blade part 200. Since each pump 501 is disposed below the cap portion 100 and the blade portion 200, the height difference facilitates the suction of ink or cleaning liquid from each portion. Then, the ink or the cleaning liquid sucked by each pump 501 is discharged to the discharge portion 600 by the discharge pipe 503.

As the type of the pump 501, the absorber 10 is used.
In order to stabilize the wetting of the blade 3 and the blade 201, a pulse-driven pump or a positive displacement metering pump that uses a diaphragm or bellows and has a constant number of rotations per hour is suitable.

(6) Discharging Portion 600 The discharging portion 600 includes the communication port 108 of the cap portion 100 (see FIG. 5), the discharging pipe 204a of the blade portion 200 (see FIG. 9), and the discharging pipe 304a of the preliminary discharge portion 300 (see FIG. 9). 10)) and the ink or cleaning liquid discharged from each discharge pipe 503 of the pump unit 500 to the outside of the image forming apparatus. As shown in FIG.
01 and a hose 602.

The liquid receiving portion 601 is a gutter-shaped member that is arranged at an inclination, and has the communication port 108 and the discharge pipes 204a and 304.
The ink or cleaning liquid discharged from the a and 503 is received. The hose 602 is connected to the lower end of the liquid receiving unit 601, and the ink or cleaning liquid received by the liquid receiving unit 601 flows into the side groove 603 via the hose 602.

Next, the recording operation of the image forming apparatus and the related operation of each part of the recovery apparatus 20 will be described with reference to FIGS. 1, 11 and 12. FIG. 11 shows FIG.
12 is a configuration diagram of the recovery device 20 for explaining the recovery operation of the image forming apparatus shown in FIG. 12, and FIG. 12 is a flowchart of the recording operation and the recovery operation of the image forming apparatus shown in FIG.

Prior to recording, first, the recording medium A is set by being wound around the feeding unit 3, the transport unit 2, and the winding unit 4, and when the setting of the recording medium A is completed, the recording operation is started (step S1). ). Before starting the recording operation, the carriage 10 is located at the home position, and each recording head 11 is capped by the cap portion 100.

When the recording operation is started, the cap portion 10
The support plate 111 of 0 is moved downward to release the capping (step S2), and the ink is fed from the ink supply device 13 (step S3). As a result, the ink is forcibly pushed out from the recording head 11, and the pushed ink is absorbed by the absorber 103 (see FIG. 5) provided in the cap 101 of the cap portion 100.

When the ink pressure feeding is completed, the carriage 1
0 is moved in the direction of arrow P1 and the recording head 11 is wiped by the blade 201 of the blade unit 200 (step S4). At this time, the solenoid valve 402 of the tank portion 400 is opened, and the tank 401 is removed from the cap portion 100.
The cleaning liquid is supplied into the cap 101. As a result, the cap 101 of the cap unit 100 and the absorbers 103 and 110 are washed. The cleaning liquid flows into the receiving portion 104 (see FIG. 5) of the holder 102 together with the ink pushed out from the recording head 11 by pressure feeding of the ink,
Further, it overflows from the receiving portion 104 and is collected by the liquid collecting member 105, passes through the discharge pipe 105a, and receives the liquid receiving portion 60 of the discharging portion 600.
Fall to 1. The excess cleaning liquid absorbed by the absorbent body 103 is sucked by the pump 501 of the pump unit 500 for the cap unit 100 via the suction pipe 502, and then falls through the discharge pipe 503 to the liquid receiving unit 601.

After the wiping is completed, the blade portion 20
The blade 501 of 0 and the cleaning liquid excessively sucked by the blade 201 by the cleaning of the blade 201 are sucked by the pump 501. This operation is completed by the next wiping.

Next, image data for one scan (during forward movement in the direction of arrow P1) is transferred from a data transfer source such as a computer or a reader to a recording control unit (not shown) of the image forming apparatus (step S1). S5). When the data is transferred, the carriage 10 is further moved in the direction of the arrow P1 and after the preliminary ejection is performed above the preliminary ejection unit 300 (step S6),
Image recording for one scan is performed (step S7). And
The recording medium A is intermittently fed by the recording unit 2 by the recording length L (step S8).

Here, it is judged whether or not the image recording is ended (step S9), and if it is ended, the carriage 10
To the home position, and the cap 100 caps the recording head 11 (step S1).
0), the recording operation ends (step S11).

When the recording head 11 is capped, the electromagnetic valve 109 of the pipe connected to the communication port 108 (see FIG. 5) of the cap portion 100 is opened, and the cap between the recording head 11 and the cap 101 formed by capping. The pressure in the space is prevented from rising due to the close contact between the two. The gas or liquid flowing into the communication port 108 by opening the electromagnetic valve 109 drops into the liquid receiving portion 601 of the discharge portion 600. When the capping operation is completed, the solenoid valve 10
9 is closed. Simultaneously with the end of the recording operation, the cleaning liquid is supplied from the tank 401 to the preliminary ejection unit 300, and the absorber 301 (see FIG. 10) of the preliminary ejection unit 300 is cleaned. The liquid overflowing from the preliminary ejection unit 300 due to the supply of the cleaning liquid to the preliminary ejection unit 300 drops to the liquid receiving unit 601 of the ejection unit 600 through the ejection pipe 304a.

On the other hand, if the image recording is continued, the image data for the backward movement in the direction of arrow P2 is transferred next (step S12), and the carriage 10 is moved in the direction of the arrow P2 to record the image for the backward movement. Perform (step S13). After the image recording in the backward movement is performed, the recording medium A is intermittently fed in the same manner as in step S8 (step S14).

Then, it is judged again whether or not the image recording is to be ended (step S15). If the image recording is to be ended, the carriage 10 is moved to the home position, and the cap portion 100 is moved.
The recording head 11 is capped by (step S
10) The recording operation is finished (step S11). If the image recording is to be continued, it is determined whether or not the ink pressure feeding according to the number of scans is necessary (step S16). If necessary, the carriage 10 is moved to a position above the cap portion 100, the ink pressure feeding in step S3 is performed, and the operations from step 4 onward are repeated. On the other hand, if unnecessary, the carriage 10
Is moved above the blade portion 200 to perform the wiping of step 4, and the operations from step 5 onward are repeated.

(Second Embodiment) An example in which the operation of the carriage after ink pressure feeding is different from that of the first embodiment will be described with reference to FIG. Since the configuration itself of the image forming apparatus is the same as that of the first embodiment, the same reference numerals as those shown in the first embodiment are attached to FIG. 13, and the description of the configuration is omitted.

After the ink is pressure-fed, even if the ink droplet 1010 formed on the ejection port surface 1006 of the recording head 11 grows, it does not drop from the ejection port surface 1006 and the ejection port surface 1006.
In some cases, a large amount of ink droplets 1010 may remain attached. This phenomenon is mainly due to the physical properties of ink (surface tension),
It depends on the physical properties (contact angle) of the interface between the ink and the ejection port surface 1006. When capping is performed in this state, the absorber 10
With 3, the ink cannot be completely absorbed. Then, the ink that cannot be completely absorbed is pushed back into the recording head 13 from the ejection port.

In order to prevent this, the carriage 10 is slightly reciprocated after ink pressure feeding to vibrate the recording head 13. As a result, the ink droplet 1010 attached to the ejection opening surface 1006 shakes and falls on the cap 101. At the same time, the pump unit 500 is driven to absorb the ink dropped from the ejection port surface 1006 by the absorber 103,
The ink absorbed by the ink is discharged to the outside by suction by the pump unit 500. After that, capping is performed as in the first embodiment. By such an operation, the large ink droplet 1010 formed on the ejection port surface 1006 can be removed. The cleaning of the cap 101 is the same as in the first embodiment.

(Third Embodiment) Here, an example in which ink is pressure fed to an initial recording head will be described with reference to FIG. Also in this embodiment, the configuration itself of the image forming apparatus is similar to that of the first embodiment, and therefore, the same reference numerals as those shown in the first embodiment are attached to FIG. 14, and the description of the configuration is omitted.

In general, a new recording head 13 is preliminarily filled with a specific liquid 1020 in order to prevent the inside of the discharge port from being dried and to prevent dust from entering and to age the ink inside the discharge port. This liquid 1020 is a clear ink,
To reduce costs, we use frequently used color inks. For this reason, when the ink runs out during recording and a new recording head 13 is to be replaced, the operation of the apparatus is interrupted and the new recording head 13 is filled with the enclosed liquid 1.
It is necessary to discharge 020 and further fill the ink used for recording before mounting it on the apparatus.

Therefore, in the present embodiment, a new recording head 13 is mounted on the carriage 10 while the liquid 1020 is enclosed.
Attach to. Then, the recording head 13 is positioned on the receiving portion 104 of the holder 102, ink is pressure-fed at this position, and the liquid 1020 is pushed out from the recording head 13 by the original ink and discharged. The reason why the ink is pressure-fed by the receiving portion 104 outside the cap 101 is that if the ink is pressure-fed by the absorber 103, the liquid 1020 pushed out from the recording head 13 adheres to the absorber 103. . As described above, since the receiving portion 104 is formed in the holder 102, the ink is pressure-fed on the receiving portion 104,
The liquid 1020 enclosed in the recording head 13 can be easily discharged. As a result, the operation interruption time of the apparatus at the time of replacing the recording head 13 can be reduced, and efficient recording can be performed.

[0083]

Since the present invention is configured as described above, it has the following effects.

In the image forming apparatus of the present invention, which has a cap member inside which an absorber is provided, a cleaning liquid supply means for supplying a cleaning liquid into the cap member and a liquid in the cap member are sucked and discharged. Since it has a suction means for cleaning the inside of the cap member and the absorber, it is possible to suppress the formation of precipitates inside the cap member and the absorber. As a result, the recovery function is deteriorated due to the accumulation of deposits, and the deposits are prevented from adhering to the recording head due to capping, so that stable ejection of ink from the recording head can be maintained.

Further, by providing the cap member with a communication means for communicating the inside and the outside of the cap member, when the recording head is capped by the cap member, the air or liquid in the cap member is discharged to the ejection port of the recording head. Backflow can be prevented. In particular, by connecting the opening / closing means for arbitrarily opening / closing the communication means to the communication means, the communication means can be closed after the capping operation is completed, and the ink in the ejection port can be prevented from drying.

Further, by forming a receiving portion around the cap member for receiving the liquid at a position lower than the contact surface between the cap member and the recording head, the cleaning liquid overflows from the cap member, and the outside of the cap member also. Can be washed. In this case, the second absorber that absorbs the liquid is further provided outside the cap member, so that the ink forcedly pushed out of the recording head absorbs the ink even if the ink comes off the outside of the cap member. be able to. Moreover, since the other end of the second absorber is immersed in the liquid received in the receiving portion, the ink absorbed in the second absorbing body is guided to the receiving portion and the ink outside the cap member is introduced. It is possible to suppress dirt caused by.

On the other hand, in the case of having the preliminary discharge part in which the absorber is provided, the absorber is provided in the storage part, and further the cleaning liquid supply means for supplying the cleaning liquid into the storage part,
Since it has the discharging means for discharging the liquid in the storage section, it is possible to wash the absorber in the preliminary discharge section and suppress the formation of precipitates on the absorber, as in the case of having the cap member described above.

In this case, by providing the cleaning liquid supply means and the discharge means at positions facing each other with the absorber interposed therebetween, a flow of the cleaning liquid from the cleaning liquid supply means to the discharge means is formed,
The absorbent body can be effectively cleaned.

In addition, by providing an electrothermal converter for generating heat energy as a means for applying ink ejection energy to the recording head, the ejection ports can be arranged at high density and high resolution image formation can be performed. It becomes possible.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of an embodiment of an image forming apparatus of the present invention.

FIG. 2 is a main sectional view of the image forming apparatus shown in FIG.

3 is a perspective view of relevant parts showing an internal structure of an element head of the recording head of the image forming apparatus shown in FIG.

FIG. 4 is an enlarged perspective view of a cap portion of the image forming apparatus shown in FIG.

5 is a cross-sectional view in the X direction near the holder of the cap portion shown in FIG.

6 is a cross-sectional view in the Y direction near the holder of the cap unit shown in FIG.

FIG. 7 is a diagram for explaining the operation of the cap portion shown in FIG. 4, showing a state during ink pressure feeding.

FIG. 8 is a diagram for explaining the operation of the cap portion shown in FIG. 4, showing a cleaning state of the cap.

9 is a cross-sectional configuration diagram of a blade portion of the image forming apparatus illustrated in FIG.

10 is a cross-sectional configuration diagram of a preliminary ejection unit of the image forming apparatus illustrated in FIG.

11 is a configuration diagram of a recovery device for explaining a recovery operation of the image forming apparatus shown in FIG.

FIG. 12 is a flowchart of a recording operation and a recovery operation of the image forming apparatus shown in FIG.

FIG. 13 is a diagram for explaining the operation of the second embodiment of the image forming apparatus of the present invention after the ink has been pressure-fed at the cap portion.

FIG. 14 is a diagram for explaining the operation of the third embodiment of the image forming apparatus of the present invention during ink pressure feeding in the cap portion.

[Explanation of symbols]

 1 Printer Part 1a, 1b Scanning Rail 1c Tube 2 Conveying Part 3 Feeding Part 4 Winding Part 5 Drying Part 10 Carriage 11 Recording Head 13 Ink Supply Device 20 Recovery Device 100 Cap Part 101 Cap 102, 202, 302 Holder 102a Cap Mounting Part 102b, 204, 304 Drain 102c Tip 103, 110, 301 Absorber 104 Receptor 105 Liquid collecting member 105a, 204a, 304a Discharge pipe 106 Liquid inlet 107 Suction port 108 Communication port 109 Electromagnetic valve 111 Support plate 112 Guide rail 113 Air Cylinder 114 Side plate 200 Blade part 201 Blade 203 Septic tank 300 Preliminary discharge part 303 Washing nozzle 400 Tank part 500 Pump part 501 Pump 502 Suction pipe 503 Discharge pipe 600 Discharge part 6 1 liquid receiving part 602 the hose 603 groove 1001 discharge port 1002 fluid path 1003 the common liquid chamber 1004 energy generating means 1005 electrodes 1006 discharge port surface A recording medium

Claims (9)

[Claims] 1. A recording head which ejects ink from an ejection port, a cap member which is disposed outside a recording region of the recording head and seals a surface of the recording head on which the ejection port is formed, when not recording, In an image forming apparatus, which is provided inside the cap member, and has an absorber that absorbs ink forcedly pushed out from the recording head, if necessary, a cleaning liquid supply unit that supplies a cleaning liquid into the cap member, An image forming apparatus comprising: a suction unit that sucks and discharges the liquid in the cap member. 2. The image forming apparatus according to claim 1, wherein the cap member is provided with a communication unit that communicates the inside and the outside of the cap member. 3. The image forming apparatus according to claim 2, wherein an opening / closing means for arbitrarily opening / closing the communication means is connected to the communication means. 4. A receiving portion, which is formed around the cap member, receives the liquid at a position lower than a contact portion of the cap member with the recording head, and a discharging means for discharging the liquid in the receiving portion. The image forming apparatus according to claim 1, 2 or 3 having. 5. The outside of the cap member has one end located near a contact portion of the cap member with the recording head, and the other end immersed in the liquid received in the receiving portion. The image forming apparatus according to claim 4, further comprising a second absorber arranged to absorb the liquid. 6. A recording head which ejects ink from an ejection port, and an absorption which is arranged outside the recording area of the recording head and absorbs ink ejected separately from recording from the recording head, if necessary. In an image forming apparatus having a pre-ejection unit provided with a body, the absorber is provided in a storage unit that stores a liquid, a cleaning liquid supply unit that supplies a cleaning liquid into the storage unit, and the storage unit is stored in the storage unit. And an ejecting means for ejecting the liquid. 7. The image forming apparatus according to claim 6, wherein the cleaning liquid supply unit and the discharge unit are provided at positions facing each other with the absorber interposed therebetween. 8. The image forming apparatus according to claim 1, wherein the recording head includes an electrothermal converter for generating thermal energy used for ejecting ink. . 9. The image forming apparatus according to claim 8, wherein the recording head ejects the ink from the ejection port by utilizing the film boiling generated in the ink by the thermal energy applied by the electrothermal converter.