JP2004168002A - Inkjet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recorder in which ink and foreign substances adhered to the nozzle of an inkjet head is removed and a thickened substance of ink is not deposited on the sides of the inkjet head. <P>SOLUTION: The inkjet recorder comprises a blade provided with a water repellent section and a hydrophilic section, and a nozzle cover of the head provided with a water repellent section on the opposed surfaces and the sides thereof. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ink jet recording apparatus having a blade for removing ink and foreign matter attached to nozzles of an ink jet head and capable of obtaining a high quality image on a recording medium.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, ink jet recording systems have been used in printers, copiers, and the like because of their low noise, low running cost, easy downsizing of their apparatuses, and easy colorization.
[0003]
In an ink jet recording apparatus that prints ink droplets from a nozzle on a recording material, a negative pressure is generated in the nozzle to absorb the ink, so that ink that has a problem, such as mixing of dust or clogging due to drying of the ink, can be discharged from the nozzle. A suction recovery unit is provided for discharging or filling the nozzles with ink in the ink tank.
[0004]
The suction recovery means includes a capping means for the ink jet head, a negative pressure generating means for generating a negative pressure on the nozzle, and a wiping means for wiping around the nozzle with a blade.
[0005]
The blade is for removing ink and foreign matters attached to the nozzles of the inkjet head.
[0006]
The blade is composed of a member in which a member having elasticity and a member having absorptivity are integrally joined, and the member having elasticity in the first wiping advancing direction of the blade is made to absorb water in the second wiping advancing direction. An ink jet recording apparatus in which a member having the above is disposed is disclosed in Japanese Patent Application Laid-Open No. Hei 6-71904.
[0007]
According to the above configuration, since the second wiping is performed by the blade having the water absorbing force after the first wiping of only the blade having the elastic force, the ink that cannot be completely removed by the first wiping is absorbed by the second wiping. By removing the ink, the ink on the nozzle surface can be reliably removed.
[0008]
Japanese Patent Application Laid-Open No. Hei 10-272781 discloses a configuration of a blade that slides a nozzle of an ink jet head by a member that absorbs ink and an elastic member that does not absorb ink.
[0009]
According to the above configuration, a member that absorbs ink is disposed in front of the blade in the traveling direction, and an elastic member that does not absorb ink is disposed in the rear, and the blade bends in a direction opposite to the traveling direction. The sliding contact is at the tip of the ink absorbing member.
[0010]
JP-A-5-193151 discloses that the blade is a plate-like member having water repellency.
[0011]
Japanese Patent Application Laid-Open No. 8-001955 discloses a configuration in which ink is guided between a blade and a guide member extending to near a sliding portion of the blade.
[0012]
A nozzle cover that covers a peripheral portion of the nozzle forming member of the ink jet head and a side surface of the head; water-repellent treatment is performed on a surface of the nozzle cover facing the recording medium; and roughening treatment is performed on the side surface of the nozzle cover. Alternatively, a configuration in which an absorbing member capable of absorbing ink is provided on the side surface of the nozzle cover is disclosed in Japanese Patent Application Laid-Open No. 9-254394.
[0013]
Japanese Patent Application Laid-Open No. H11-240163 also discloses a configuration having an absorbing member in the vicinity of a contact portion of an ink jet head with a blade.
[0014]
Japanese Patent Application Laid-Open No. 2000-198211 discloses a configuration for removing a thickened substance of ink deposited on a side surface of an inkjet head.
[0015]
In the above configuration, a slit is provided in the blade, and the thickened material of the ink is removed by sliding the blade dedicated to the side surface of the inkjet head.
[0016]
[Problems to be solved by the invention]
However, in Japanese Patent Application Laid-Open Nos. Hei 6-71904, Hei 10-272781, Hei 5-193151, Hei 9-254394, and Hei 8-001955, the ink jet head is used. Although there is an effect on the performance of absorbing and removing ink on the nozzle surface, the effect is not sufficiently obtained on the performance of removing ink on the side surface of the ink jet head.
[0017]
In particular, in the case of pigment ink, the viscosity of the ink is significantly increased due to evaporation of the ink solvent, and the thickened material of the ink is deposited on the side surface of the inkjet head. In the worst case, the thickened material is re-transferred to the blade and further re-transferred to the nozzle of the ink jet head, thereby affecting printing.
[0018]
In Japanese Patent Application Laid-Open No. H11-240163, placing an ink absorbing member near the side surface of an ink jet head has a certain effect, but the ink absorbing capacity is limited, and there is no effect when a certain capacity is exceeded. turn into. Further, it is not advisable to take into account the arrangement space and cost of the ink absorbing member.
[0019]
In Japanese Patent Application Laid-Open No. 2000-198211, there is an effect on a side surface parallel to the traveling direction of the blade, but there is no effect on a side surface perpendicular to the traveling direction of the blade.
[0020]
Furthermore, a configuration in which a blade dedicated to the side surface perpendicular to the direction of travel of the blade is conceivable is considered, but this is also not advantageous from the viewpoint of arrangement space and cost.
[0021]
Therefore, an object of the present invention is to improve the prior art, with a simple configuration, to remove ink and foreign matter attached to the nozzles of the inkjet head, and not to deposit a thickened material of the ink on the side surface of the inkjet head, An object of the present invention is to provide an ink jet recording apparatus having a blade and an ink jet head for obtaining high image quality.
[0022]
[Means for Solving the Problems]
In order to achieve the above object, the following problem has been solved.
[0023]
That is, an ink jet recording apparatus according to the present invention is an ink jet recording apparatus that discharges ink from a nozzle of an ink jet head and performs printing on a recording medium. The ink jet recording apparatus slides on the nozzle and removes ink and foreign matter attached to the nozzle. A peripheral portion that comes into contact with the nozzle has water repellency, a portion that does not come into contact with the nozzle has hydrophilicity that absorbs ink, and the blade has a hydrophilic surface on which the blade comes in contact with the nozzle. The portion having the property is uneven in a direction substantially perpendicular to the nozzle surface of the inkjet head, the corner of the uneven shape is R0.2 mm or less, a distance L1 from the nozzle to the hydrophilic portion, The penetration amount L2 of the blade into the nozzle is characterized by L1>L2> 2 mm.
[0024]
A portion having a hydrophilic property on a surface side of the blade in contact with the nozzle includes a member having an absorptive property.
[0025]
The inkjet head has a nozzle cover that covers a peripheral portion and a side surface of a nozzle forming member that has formed the nozzle, and the nozzle cover that covers the peripheral portion and the side surface of the nozzle forming member has a water repellent surface and a side surface facing a recording medium. It is characterized by having.
[0026]
The ink jet head has a nozzle cover that covers a peripheral portion and a side surface of a nozzle forming member on which the nozzles are formed, and a surface of the nozzle cover that covers the peripheral portion and the side surface of the nozzle forming member, which faces a recording medium, and advances the blade. It is characterized in that two side surfaces in the direction are provided with water repellency.
[0027]
BEST MODE FOR CARRYING OUT THE INVENTION
(Embodiment 1)
1 to 9 show a first embodiment of the ink jet recording apparatus of the present invention.
[0028]
FIG. 1 is an exploded perspective view showing a configuration of a suction recovery unit having a capping unit, a negative pressure generating unit, and a valve unit.
[0029]
FIG. 2 is an exploded perspective view showing the configuration of an ink jet recording apparatus using suction recovery means.
[0030]
3 is an exploded perspective view showing the configuration of a carriage in the inkjet recording apparatus, a recording head that can be mounted on the carriage, and an ink tank.
[0031]
As shown in FIGS. 2 and 3, a recording head 8 can be mounted on the carriage 6.
[0032]
A recording head 8 and a processing liquid ink tank 9S in which a nozzle row of the processing liquid S, a nozzle row of the black ink Bk, and a nozzle row of the color ink YMC are arranged side by side from the farthest from the printing area at the home position (HP). And ink tanks 9Bk for black ink and ink tanks 9C, 9M, and 9Y for color ink.
[0033]
In this example, black, yellow, magenta, and cyan ink tanks are all independently replaceable.
[0034]
The recording head 8 has an integrated head configuration of two nozzle rows of black and color. Among them, the color nozzle row has a three-color integrated head configuration in which three nozzle rows of yellow, magenta, and cyan are vertically aligned.
[0035]
The recording head 8 is electrically connected via a connector 8022 on the carriage 6.
[0036]
The recording head 8 is an inkjet recording unit that discharges ink using thermal energy, and includes an electrothermal transducer for generating thermal energy.
[0037]
Further, the recording head 8 performs recording by discharging ink from the discharge ports by utilizing a pressure change caused by growth and shrinkage of bubbles due to film boiling caused by thermal energy applied by the electrothermal transducer.
[0038]
The recording head 8 has four ink supply ports 8030 (black 8030Bk, cyan 8030C, magenta 8030M, and black 8030Bk) for supplying ink from the ink tank 9Bk for black ink and the ink tanks 9C, 9M, and 9Y for color ink. Yellow 8030Y,), from which ink is supplied to each nozzle of the recording head through a flow path in the head.
[0039]
A guide shaft 4 and a support shaft 103 for slidably instructing the carriage 6 are provided on both side walls of the substantially U-shaped chassis 1. The driving force of the carriage 6 that reciprocates on these shafts in the main scanning direction is given from the carriage motor 104 via the driving belt 10.
[0040]
In addition, the recording medium is nipped and conveyed by the LF motor as a driving source by the conveying roller 2 and the pinch roller 3 as shown in FIG. 2, and the recording medium is conveyed onto the platen 16.
[0041]
At this time, the recording portion of the recording head 8 mounted on the carriage 6 protrudes downward from the carriage 6, and the ejection port forming surface of the recording head 8 faces the recording medium on the platen 16 in parallel to perform printing.
[0042]
A recovery system unit 15 (suction recovery means) is provided at a home position on the left side of the recording apparatus.
[0043]
The capping means corresponds to the recording head 8, and includes a cap 112 for black ink and a cap 114 for color ink from the left in the figure (capping means).
[0044]
The caps 112 and 114 are supported by cap holders 122 and 124, respectively.
[0045]
The cap holders 122 and 124 are fixed to one end of a cap lever 132 rotatably fixed to the recovery system base 130.
[0046]
The cap lever 132 is urged by a cap spring 133 provided between the cap lever 132 and the recovery system base.
[0047]
A part of the cap lever 132 is in contact with a cam surface 141 of a control cam 140 as capping control means.
[0048]
Thus, when the control cam 140 rotates, the cap lever 132 rotates in the vertical direction, and accordingly, the caps 112 and 114 move in the vertical direction to press the recording head 8.
[0049]
The control cam is rotatably fixed to the recovery system base 130, and drive is transmitted from a drive source (not shown) via a gear.
[0050]
The black ink cap 112 and the color ink cap 114 of the recovery system unit 15 communicate with the suction tubes 145 and 150 of the pump unit 119 (suction pressure generating means) via the cap holders 122 and 124, respectively.
[0051]
The pump unit 119 is used to generate a negative pressure during a suction recovery process for connecting the cap unit and the print head and sucking ink from the discharge ports of the print head when the print head fails to discharge. The pump unit 119 in the example shown here is called a tube pump.
[0052]
FIG. 4 is a plan sectional view of the pump unit 119. FIG.
[0053]
The pump unit 119 includes a suction tube 145 for color ink, a suction tube 150 for black ink, a roller holder 144 (a pressure member supporting member), a roller 147 (a pressure member), and a pressure guide for the recovery system base 130. 130A. The roller holder 144 is rotatably secured to the recovery system base 130.
[0054]
Tubes 145 and 150 are guided by roller holder 144.
[0055]
When the roller holder 144 is rotated, the suction tubes 145 and 150 are pressed into the cap by squeezing the suction tubes 145 and 150 while pressing the suction tubes 145 and 150 with the pressing guide 130A of the recovery system base 130 and the roller 147 fixed to the roller holder 144. Generate negative pressure.
[0056]
The waste liquid is sent to the waste liquid tank 401 through independent paths.
[0057]
FIG. 5A shows the cap retracted state, and FIG. 5B shows the cap state.
[0058]
When the print head is waiting at the home position for a certain period of time or more, as shown in FIG. 5B, all the caps come into contact with the print head portion to cap it, and the ink in the discharge ports of the print head evaporates. To prevent ejection failure due to thickening and sticking caused by the above. By operating the tube pump in this state, all heads can be sucked.
[0059]
Further, as shown in FIG. 5A, all the caps are retracted. By operating the pump on the tube in this state, it is possible to perform idle suction even during printing. The preliminary ejection is performed in each cap with the cap retracted. By operating the tube pump in this state, idle suction for sucking the ink in the cap accumulated by the preliminary ejection is possible.
[0060]
Returning to FIG. 1, the recovery system unit 15 is further provided with a black ink blade 1119 for wiping the nozzles of the black ink and a color ink blade 118 for wiping the nozzles of the color ink recording head.
[0061]
The black ink blade (first blade) 1119 is separately disposed on the upstream side of the black ink nozzle row in the paper transport direction, and the color ink blade (third blade) 118 is separately disposed on the upstream side of the color ink nozzle row in the paper transport direction. I have.
[0062]
Each of these blades is a blade formed of an elastic member such as rubber for wiping ink adhered to the nozzles of the recording head.
[0063]
FIG. 6 is a sectional view showing the configuration of the wiping mechanism.
[0064]
As shown in FIGS. 1 and 6, the blades 117, 118, and 1119 are mounted on a blade arm 142 which is mounted on a guide portion 130G of the recovery system base 130 so as to be movable in parallel with the recording head 8. The guide portion 130G normally controls the blade penetration amount, the contact angle, and the contact pressure with respect to the recording head 8 to be constant.
[0065]
A rack gear 142G is provided on a part of the blade arm 142, and is connected to the blade gear 1153 while being urged by a blade spring 1152. When the blades 117, 118, and 1119 are urged by the wiper spring 1152 (not tightly wound), they are not in contact with the recording head 8 (first retract position A).
[0066]
130S is a blade arm retreat position regulation of the recovery system base 130.
As the blade gear 1153 driven by the drive source rotates, the blade arm 142 moves in parallel with the recording head 8 on the recovery system base 130 (forward).
[0067]
When the blade arm 142 has moved a sufficient stroke of the nozzle row, and the blades 117, 118, and 1119 have moved further from positions where the blades 117, 118, and 1119 do not contact the recording head 8 (second retreat position B), the blade gear 1153 has partially missing teeth. 153K, the drive is released, and the blade arm returns to the blade arm first retreat position by the spring force of the blade spring 1152 (return).
[0068]
The portions 1319, 1317, and 1318 of the blade that are in sliding contact with the nozzles of the recording head have water repellency. Below the water-repellent portions 1319, 1317, and 1318 on the sliding contact surface side, concave and convex shapes 1219, 1217, and 1218 having hydrophilicity are formed in the direction facing the nozzles of the recording head.
[0069]
The ink of the nozzle removed by the blade is further absorbed below the blade by the capillary force at the corners of the uneven shape.
[0070]
Here, the corner of the concave portion is desirably 0.2 mm or less in order to obtain a sufficient capillary force.
[0071]
Further, it is desirable that the penetration amount L2 of the blade into the nozzles of the recording head and the distance L1 from the nozzles of the recording head to the irregularities 1219, 1217, and 1218 having hydrophilicity satisfy L1>L2> 2 mm. If the distance L1 is too short, it will affect the ink removability of the nozzles, and if it is too long, sufficient water absorption will not be obtained.
[0072]
The recording head 8 has a nozzle forming member 801 in which a nozzle is formed, and a nozzle cover 802 that covers a peripheral portion and a side surface of the nozzle forming member. The nozzle cover protects the nozzle forming member, and is integrally formed of a SUS material or the like. The facing surface 805 of the nozzle cover facing the recording medium and two side surfaces 803 and 804 perpendicular to the direction of travel of the blade have water repellency.
[0073]
The ink around the nozzles is removed by a blade and is brought to the side surfaces 803 and 804 of the nozzle cover 802, but is repelled by the water repellency of the side surfaces 803 and 804 and the blades 1319, 1317 and 1318, and the uneven shape having hydrophilicity of the blade is provided. Since water is absorbed by 1219, 1217, and 1218, ink does not accumulate on the side surface of the nozzle cover.
[0074]
As shown in FIGS. 1 and 7, a CR lever 160 as capping positioning means is rotatably fixed to the recovery system base 130. Since one end of the CR lever 160 is urged against the cam portion of the control cam 140 by the CR lever spring 160SP, the CR lever 160 moves up and down by rotation of the control cam.
[0075]
The CR lever 160 is controlled so as to be raised at the home position of the carriage. At this time, the engagement convex portion 161 provided on the CR lever 160 is engaged with the engagement concave portion 162 provided on the carriage or the recording head 8. The contact position between the recording head 8 and the cap during capping is determined (see FIG. 7B). During printing, the CR lever 160 is lowered so as not to hinder the movement of the carriage (see FIG. 7A).
[0076]
FIGS. 8 and 9 show drive switching means between the wiping means and the pump unit.
[0077]
The idle gears 201, 202, 205, the sun gear 203, and the switching arm 206 are rotatably fixed to the recovery system base 130. The planetary gear 204 is rotatably fixed to the switching arm 206 with the friction spring 207 urged. The bush nut 208 is press-fitted and fixed to the shaft of the switching arm 206 to prevent the planetary gear 204 from coming off.
[0078]
When driven by a drive motor (not shown) and the idle gear 205 rotates in the direction 205A, the switching arm 206 rotates in the direction 206A and the planetary gear 204 transmits the drive to the idle gear 201. The idle gear 201 transmits drive to the pump unit by a gear train (not shown).
[0079]
Conversely, by rotating the drive motor in the reverse direction, when the idle gear 205 rotates in the direction 205B, the switching arm 206 rotates in the direction 206B, and the planetary gear 204 transmits the drive to the idle gear 202. The idle gear 201 transmits drive to a control cam by a gear train (not shown), and transmits drive to a capping unit, a communication valve, a wiping unit, and a carriage positioning unit.
[0080]
The home position of the control cam 140 is determined by using an electric sensor (not shown) (for example, a photo interrupter).
[0081]
(Embodiment 2)
FIG. 10 and FIG. 12 show a second embodiment of the ink jet recording apparatus of the present invention.
[0082]
In the first embodiment, a concave / convex shape having hydrophilicity is formed below the portion having the water repellency on the side of the blade that slides in contact with the nozzle of the inkjet head. Below the portion having water repellency, groove portions 2219, 2217, and 2218 having hydrophilicity were formed in the direction facing the nozzles of the inkjet head.
[0083]
The depth of the groove is less than the thickness of the blade, and the corners of the groove are necessary to obtain capillary force.
[0084]
Also in this case, the corner of the concave portion is desirably 0.2 mm or less in order to obtain a sufficient capillary force.
[0085]
(Embodiment 3)
FIG. 11 shows a third embodiment of the ink jet recording apparatus of the present invention.
[0086]
Here, the members 3219, 3217, and 3218 having absorptivity are arranged on the hydrophilic portion on the side where the blade contacts the nozzle of the recording head.
[0087]
The member having absorptivity extends to the vicinity of the nozzle, but does not abut the nozzle.
[0088]
A blade is in contact with the nozzle, and the ink on the nozzle surface scraped by the blade is absorbed by a member having absorptivity.
[0089]
【The invention's effect】
As described above, according to the present invention, an ink jet recording apparatus that discharges ink from a nozzle of an ink jet head and prints on a recording medium is slidably contacted with the nozzle and removes ink and foreign matter adhering to the nozzle. The blade has a water-repellent portion in contact with the nozzle, a portion not in contact with the nozzle has a hydrophilic property to absorb ink, and a surface side in which the blade contacts the nozzle. The portion having hydrophilicity is uneven in a direction substantially perpendicular to the nozzle surface of the ink jet head, the corner of the uneven shape is R0.2 mm or less, and the distance L1 from the nozzle to the hydrophilic portion is And the amount of penetration L2 of the blade with respect to the nozzle is L1>L2> 2 mm, and the blade has hydrophilicity on the surface side in contact with the nozzle. A nozzle cover that covers a peripheral portion and a side surface of a nozzle forming member that has formed the nozzle of the inkjet head, the nozzle cover that covers a peripheral portion and a side surface of the nozzle forming member. Simple structure with water repellency on the surface and side surface facing the recording medium to remove ink and foreign matter adhering to the nozzles of the ink jet head, and to accumulate thickened ink on the side surface of the ink jet head An ink jet recording apparatus having a blade and an ink jet head and capable of obtaining high image quality can be provided.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing the configuration of a recovery system unit (suction recovery means) according to a first embodiment.
FIG. 2 is an exploded perspective view showing the configuration of an ink jet recording apparatus using the recovery system unit (suction recovery means) of the first embodiment.
FIG. 3 is an exploded perspective view illustrating a configuration of a carriage, a recording head mountable on the carriage, and an ink tank in the inkjet recording apparatus according to the first embodiment.
FIG. 4 is a cross-sectional plan view illustrating a configuration of a pump unit (suction negative pressure generating means) in the inkjet recording apparatus according to the first embodiment.
FIG. 5 is a diagram illustrating a suction mode in the inkjet recording apparatus according to the first embodiment.
FIG. 6 is a cross-sectional view illustrating a configuration of a wiping mechanism in the inkjet recording apparatus according to the first embodiment.
FIG. 7 is a view for explaining capping positioning means in the ink jet recording apparatus of the first embodiment.
FIG. 8 is a plan view of a drive switching mechanism in the inkjet recording apparatus according to the first embodiment.
FIG. 9 is a sectional view of a drive switching mechanism in the inkjet recording apparatus according to the first embodiment.
FIG. 10 is an exploded perspective view showing the configuration of a recovery system unit (suction recovery means) of the second embodiment.
FIG. 11 is an exploded perspective view showing a configuration of a recovery system unit (suction recovery means) according to a third embodiment.
FIG. 12 is a diagram showing a second embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Chassis 2 Transport roller 3 Pinch roller 4 Guide shaft 6 Carriage 8 Recording head 9 Ink tank 10 Belt 15 Recovery system 16 Platen 40 Main body 103 Support shaft 104 Carriage motor 112, 114 Suction cap 117, 118, 1119 Blade 119 Pump unit 122, 124 Cap holder 130 Recovery system base 131 Cap base 132 Cap lever 133 Cap lever spring 142 Blade arm 144 Roller holder 145, 150 Suction tube 147 Roller 160 CR lever 160SP CR lever spring 161 Mating convex portions 201, 202, 205 Idle gear 203 Sun gear 204 Planetary gear 206 Switching arm 207 Friction spring 208 Bush nut 401 Waste ink tank 402 Wiper spring 1152 Blade spring 1153 Blade gear

Claims (4)

An ink jet recording apparatus that prints on a recording medium by discharging ink from nozzles of an ink jet head,
Having a blade for slidingly contacting the nozzle and removing ink and foreign matter attached to the nozzle,
The blade is provided with a water-repellent peripheral portion in contact with the nozzle, the portion not in contact with the nozzle has a hydrophilic property to absorb ink,
The portion having hydrophilicity on the surface side where the blade abuts the nozzle has a concave-convex shape integrally formed in a substantially vertical direction with respect to the nozzle surface of the inkjet head,
The corners of the uneven shape are R0.2 mm or less,
An ink jet recording apparatus, wherein a distance L1 from the nozzle to the hydrophilic portion and a penetration amount L2 of the blade into the nozzle satisfy L1>L2> 2 mm. 2. The ink jet recording apparatus according to claim 1, wherein a portion having a hydrophilic property on a surface side of the blade in contact with the nozzle has a member having an absorptive property. 3. A nozzle cover that covers a peripheral portion and a side surface of a nozzle forming member that has formed the nozzle of the inkjet head,
The ink jet recording apparatus according to claim 1, wherein a water repellency is provided on a surface and a side surface of the nozzle cover that covers a peripheral portion and a side surface of the nozzle forming member, the surface facing the recording medium. A nozzle cover that covers a peripheral portion and a side surface of a nozzle forming member that has formed the nozzle of the inkjet head,
5. The ink jet recording apparatus according to claim 1, wherein a surface of the nozzle cover that covers a peripheral portion and a side surface of the nozzle forming member faces the recording medium, and two side surfaces in a traveling direction of the blade have water repellency. 6. Recording device.

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