JP4200366B2 - Inkjet recording device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an ink jet recording apparatus, and more particularly to a high speed ink jet printer capable of recording a high-quality image with high reliability.
[0002]
[Prior art]
A line scanning ink jet printer has been proposed as a high speed ink jet printer that performs high speed printing on continuous recording paper. In this apparatus, long ink jet recording heads in which nozzle holes for ejecting ink droplets are arranged in a line are arranged in the width direction of continuous recording paper so as to face the paper surface to the full width, and ink droplets ejected from the nozzle holes. Is selectively controlled according to the recording signal. At the same time, the main scanning is performed by moving the continuous recording sheet at a high speed in the longitudinal direction. With this main scanning and landing control of ink droplets on the recording paper, recording dot formation on the scanning line is controlled to obtain a recorded image on the recording paper.
[0003]
As this line scanning type ink jet printer, many devices that use a continuous ink jet type recording head as a recording head and devices that use an on-demand ink jet type recording head have been proposed. Of these, on-demand inkjet line scan inkjet printers are not as fast as continuous inkjet printers, but are superior in high-definition recording performance and simple ink systems. Suitable for providing high-definition high-speed printers.
[0004]
The recording head for this on-demand ink jet line scanning ink jet printer applies pressure to the ink in the ink chamber having the nozzle hole as an opening by applying a driving voltage to a driving element such as a piezoelectric element or a heating element. In this line recording head, a number of nozzles configured to eject ink droplets are arranged in a row (see, for example, Patent Document 1).
[0005]
On the other hand, the present inventors installed a charge deflection electrode along the nozzle row of the line type recording head, deflected the ejected ink droplet, and a plurality of inks ejected from adjacent nozzles at each pixel position on the recording paper. Proposed a particle deflection type on-demand inkjet printer that allows multiple drops to be placed, prevents recording defects due to nozzle failure, dramatically improves recording reliability, and improves recording irregularities. (For example, refer to Patent Document 2).
[0006]
In addition, as a method for fundamentally dealing with the problem of insulation failure due to ink wetting of the charge deflection electrode, a gradient electric field generation type deflection electrode that applies a deflection electric field to ink droplets along each nozzle row has been proposed (for example, a patent) Reference 3).
[0007]
Further, in order to ensure the ejection reliability of the ink droplets, the ink droplets that have been preliminarily ejected are subjected to U-turn flight control with the gradient electric field, and the gradient electric field generation type deflection electrode also serves as a preliminary ejection ink receiving function. A deflection U-turn preliminary ejection device that collects ink droplets has been proposed (see, for example, Patent Document 4).
[0008]
As described above, this tilted electric field generating deflection electrode greatly improves the problem of insulation failure due to ink wetting, but the deflection electric field is disturbed when ink aggregates or paper dust adheres to the electrode and becomes dirty, Deflection operation failure may occur. In addition, when the electrode also serves as a preliminary ejection ink receiving function, it may hinder the ink collection.
[0009]
As a conventional technique for solving such problems, the present inventors have proposed a cleaning device that draws dirt by bringing a suction port on which a negative pressure acts on a dirty portion of the electrode (see, for example, Patent Document 5). .
[0010]
[Patent Document 1]
JP 2001-47622
[Patent Document 2]
International Publication No. 01/47713 Pamphlet
[Patent Document 3]
JP 2002-273890 A
[Patent Document 4]
International Publication No. 02/083425 Pamphlet
[Patent Document 5]
JP 2003-39710 A
[0011]
[Problems to be solved by the invention]
However, the conventional method of combining the gradient electric field generating type deflection electrode and the cleaning device has the following problems.
(1) It takes a lot of time to clean the electrodes due to ink agglomerates, paper dust, etc., which reduces the recording throughput.
(2) If the dirt cannot be removed by cleaning, a defective deflection operation or a poor ink recovery will occur, reducing the recording reliability.
(3) If the dirt is firmly attached, it must be rubbed or cleaned with a cleaning solution.
[0012]
In view of the above, an object of the present invention is to provide a high-speed ink jet printer capable of simply recording a nozzle hole and performing a capping function and recording a high-quality image with high reliability.
[0013]
[Means for Solving the Problems]
In order to solve the above-described problems, an ink jet recording apparatus according to the present invention includes an electrode installed in the vicinity where ink ejected from a nozzle hole is separated as ink particles, and a back electrode provided on the back surface of the recording paper. Equipped with In the ink jet recording apparatus for changing the ejected ink particles to an arbitrary position by forming an inclined deflection electric field that imparts a deflection force to the ink particles in a direction perpendicular to the ejection direction of the ink particles, On the orifice surface where a plurality of arranged nozzle hole rows are formed, So that the nozzle hole is exposed A resinous porous sheet having end face portions arranged along the nozzle hole row Moveable The resin porous sheet is impregnated with ink to form an electrode.
[0014]
According to a second aspect of the present invention, in the configuration of the first aspect, the resin porous sheet also serves as an ink receiver for landing ink droplets unnecessary for recording.
[0015]
According to a third aspect of the present invention, there is provided the inkjet recording apparatus according to the first or second aspect, further comprising: a supply unit that supplies the resin porous sheet; and a winding unit that collects the used resin porous sheet. The resin porous sheet can be exchanged by moving the resin porous sheet.
[0016]
According to a fourth aspect of the present invention, in the configuration of the third aspect, when the resin porous sheet is moved, the nozzle surface is slid by the resin porous sheet to clean the vicinity of the nozzle holes. Features.
[0017]
6. The ink jet recording apparatus according to claim 5, wherein an end surface portion of the resin porous sheet is formed of the resin porous sheet. So that the nozzle row is exposed above It is one side of the formed window part.
[0018]
According to a sixth aspect of the present invention, in the configuration of the fifth aspect, the nozzle hole array is closed by a non-window portion of the resin porous sheet, and the nozzle holes are capped.
[0019]
In order to solve the above-described problems, an ink jet recording apparatus according to the present invention includes an electrode installed in the vicinity where ink ejected from a nozzle hole is separated as ink particles, and a back electrode provided on the back surface of the recording paper. Equipped with In the ink jet recording apparatus for deflecting the ejected ink particles to an arbitrary position by forming an inclined deflection electric field that applies a deflection force to the ink particles in a direction perpendicular to the ejection direction of the ink particles, On the orifice surface where a plurality of arranged nozzle hole rows are formed, So that the nozzle hole is exposed Resin porous sheet configured to arrange an end face portion along the nozzle hole row To move Install and impregnate the resin porous sheet with ink to make electrodes , Except for the electrode equivalent part, coated with a metal thin film It is characterized by that.
[0020]
In order to solve the above-described problems, an ink jet recording apparatus according to the present invention includes an electrode installed in the vicinity where ink ejected from a nozzle hole is separated as ink particles, and a back electrode provided on the back surface of the recording paper. Equipped with In the ink jet recording apparatus for deflecting the ejected ink particles to an arbitrary position by forming an inclined deflection electric field that applies a deflection force to the ink particles in a direction perpendicular to the ejection direction of the ink particles, On the orifice surface where a plurality of arranged nozzle hole rows are formed, So that the nozzle hole is exposed Along the nozzle hole row And attach the metal base plate so that it overlaps the metal base. A resin porous sheet is laminated, and the resin porous sheet is impregnated with ink to form an electrode.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an example of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view and a control block diagram showing a schematic configuration of a deflection-type on-demand line type ink jet printer provided with a deflection electrode of the present invention. FIG. 2 is an enlarged perspective view from the nozzle hole side of the recording head unit 10.
[0022]
The line type recording head provided with the deflection electrode according to this example includes a line recording head main body 1 in which a plurality of recording head units 10 are mounted on a head mounter 20. On the other hand, a resin porous sheet 211 is provided on the recording paper side surface of the nozzle hole array 121 of the line recording head main body 1. As will be described later, the resin porous sheet 211 is placed in close contact with a predetermined position of the orifice plate 11 of the recording head body 10. The resin porous sheet 211 is provided with an array of windows 22 through which ink droplets can pass so that at least ink droplets ejected from each nozzle hole array 121 can land on the recording paper. . Further, the resin porous sheet 211 is a continuous sheet in which the window portions 22 are repeatedly formed in an array shape, and is wound around a porous sheet roll supply unit 212 installed in the vicinity of the recording head main body 1. ing. The porous resin roll sheet 211 drawn out from the porous sheet roll supply unit 212 has a drive motor 214 as a drive source and a porous sheet roll take-up unit installed on the opposite side via the recording head body 1. It is wound up at 213.
[0023]
The resin porous sheet 211 has a function as the deflection electrode 21. That is, at least one side of the window portion 22 formed in the resin porous sheet 211 is impregnated with ink to improve the conductivity of the resin porous sheet 211 to serve as an electrode.
[0024]
The line-type recording head main body 1 in which the deflection electrode 21 composed of the resin porous sheet 211 is brought into close contact with the surface of the orifice plate 11 is installed facing the recording paper 60. A paper back electrode 30 is disposed on the back surface of the recording paper 60, and a charge deflection control signal generation circuit 40 for supplying a charge deflection signal to the paper back electrode 30 is connected thereto. On the other hand, each recording head unit 10 is supplied with an ejection signal from the ink droplet ejection control signal generating device 50.
[0025]
The ink particle ejection control signal creation device 50 is a recording signal creation circuit 51 that creates a recording control signal based on the timing from the timing signal generation circuit 52 according to the recording signal input data, and a recording head that receives this control signal. A drive pulse generation circuit 53 that generates a drive pulse signal for driving the drive element of each nozzle of the module 10 and a driver circuit 54 that amplifies the drive pulse signal to power suitable for driving the drive pulse signal are provided. Based on the recording signal input data and the information signal from the recording signal generation circuit 51, the ejection state of the recording dot forming ink particles from each nozzle hole 12 of each recording head module 10 is monitored, and no recording dot is formed. When this state continues, a preliminary ejection signal generation circuit 56 for ejecting preliminary ejection ink particles is provided.
[0026]
The charge deflection control signal generation circuit 40 is a charge deflection signal generation circuit 41 that generates a predetermined charge deflection signal based on the timing from the timing signal generation circuit 52 and the control signal from the recording signal generation circuit 51. The back electrode driver circuit 42 amplifies the signal to a predetermined voltage.
[0027]
The paper back electrode 30 is a flat plate formed of a conductive member such as metal, and is opposed to the orifice plate 11 of each recording head unit 10 and is installed in parallel with the orifice surface at a position about 1.5 mm away from the orifice surface. The The charge deflection signal from the charge deflection control signal generation circuit 40 is applied to the paper back electrode 30.
[0028]
With such a configuration, in the line printer having the deflection electrode according to the present invention, the ink droplet ejected from the nozzle hole 12 of the recording head unit 10 according to the recording signal input data is charged and deflected and moved in the direction of the arrow A. The desired recording composed of the recording dots 70 can be performed by landing on the recording paper 60 to be recorded. Further, the ink droplets preliminarily ejected from the nozzle hole 12 are deflected by charging, fly U-turns, land on the electrode 21 of the porous sheet 211, and are collected.
[0029]
The recording head unit 10 is an on-demand inkjet type linear recording head unit, and is composed of n nozzles. As shown in FIG. 2, each nozzle has n nozzle holes 12 arranged in a row at a predetermined pitch in an orifice plate 11 made of a conductive member such as metal. Although not shown, each nozzle includes an ink pressurizing chamber having the nozzle hole 12 as an open end, an ink inflow hole that guides ink to the ink pressurizing chamber, and a manifold that supplies ink to the ink inflow hole. Yes. The ink pressurizing chamber is provided with a driving element such as a piezoelectric element or a heating element that changes the volume of the ink pressurizing chamber according to a recording signal. Each nozzle has the same structure. A drive signal from the ink particle ejection control signal generating device 50 is supplied to the drive element of each nozzle, and ink particles are ejected from each nozzle hole 12 in accordance with the recording signal. For example, if the nozzle hole has a diameter of about 30 μm, about 10 ng of ink particles are ejected toward the recording paper at 5 m / s.
[0030]
As described above, the resin porous sheet 211 is provided with a plurality of window portions 22, which serve as the deflection electrodes 21 that generate a gradient electric field. For example, in the case of a resin porous sheet 211 having a thickness of about 0.5 mm, the window portion 22 may have a rectangular shape that has a width of about 2 mm that allows ink droplets to pass through and that exposes all nozzle hole arrays 121. Further, one side of the window portion 22 is separated from the nozzle row 121 by about 300 μm and is installed in close contact with the surface of the orifice plate 11. That is, as shown in FIG. 2, it is preferable that the end surface portion 2111 is disposed along the nozzle hole row 121 and the resin porous sheet 211 is installed, and is closely attached to the surface of the orifice plate 11.
[0031]
As a material for the resin porous sheet, for example, a sintered body of ultra-high molecular weight polyethylene can be used, and pores having a pore diameter of several μm to several tens of μm are formed at a ratio of several tens of percent, and the surface roughness is several μm. Those processed to the following extent can be used. As a specific material, for example, “Sunmap” manufactured by Nitto Denko Corporation can be used.
[0032]
In addition, the suction hole portion of the purge suction pipe 33 that communicates with a pump or the like (not shown) that generates a negative pressure at the initial stage of the start of the recording operation or at the time of cleaning the nozzle hole 12, etc. And, it slides along the nozzle hole row 121 from the surface of the resin porous sheet 211 in the vicinity thereof. As a result, the electrode 21 of the resin porous sheet 211 is impregnated with the ink drawn from the nozzle hole 12. When the resin porous sheet 211 is impregnated in this way, the electrode 21 is grounded through the metal orifice plate 11 because the ink is conductive even if the resin porous sheet 211 is an insulator. It is a potential.
[0033]
In addition, the electrode 21 is fixed to the surface of the orifice plate 11 by connecting the suction path 112 having the suction holes 111 of the orifice plate 11 provided in all the recording head units 10 to a negative pressure generating source such as a pump. Thus, the resin porous sheet 211 is sucked. Furthermore, since the resin porous sheet 211 is wetted by the ink, the resin porous sheet 211 may be in close contact with the orifice plate 21, and sufficient strength can be secured. The suction hole 111 is preliminarily ejected from the nozzle hole 12, and the ink collected in the resin porous sheet 211 after flying U-turns does not exceed the saturated absorption amount of the resin porous sheet 211 as appropriate. The ink is sucked and collected.
[0034]
Subsequently, the operation of the recording head for an ink jet printer provided with the deflection electrode of the present invention will be described in more detail with reference to FIGS. FIG. 3 is a partial cross-sectional view showing a state in which the recording unit including the recording head unit 10 is cut perpendicularly to the recording paper at the section XX ′ in FIG.
[0035]
As described above with reference to FIGS. 1 and 2, the electrode 21 of the resin porous sheet 211 is at the ground potential through the metal orifice plate 11. Since the charge signal voltage from the charge deflection control signal generation circuit 40 is applied to the paper back electrode 30, an electric field is formed between the electrode 21 and the paper back electrode 30.
[0036]
FIG. 4 shows an equipotential surface 80 between the orifice plate 11 having the electrode 21 of the resin porous sheet 211 and the paper back electrode 30 in the configuration of FIG. As can be seen from this figure, the flight trajectory of the ink droplets ejected from the nozzle holes when the electric field does not act, that is, the non-deflected ink droplet flight trajectory 90, the direction of the electric field is tilted in the vicinity of the electrode 21, and the tilt An electric field 85 is formed. Therefore, if the ink droplet 14 ejected from the nozzle hole is charged by the charge deflection control signal generation circuit 40 by applying the drive pulse from the ink droplet ejection control signal generating device 50 to the drive element of each nozzle, the charging is performed. The ink droplet 14 is deflected by the gradient electric field 85 in a direction perpendicular to the non-deflecting ink droplet flight trajectory 90, that is, a direction perpendicular to the ink ejection direction. For example, when the charge polarity of the ink droplet is positive (the ink droplet has a negative charge), the electric field component 85αx in the direction perpendicular to the non-deflected ink droplet flight trajectory 90 of the gradient electric field 85α at the point α The recording ink droplet 141 is deflected following the ink droplet flight trajectory 91 (positively charged deflection ink droplet flight trajectory) shown in FIG. On the other hand, when the charged polarity of the ink droplet is negative (the ink droplet has a positive charge), the ink droplet 141 for recording is traced along the ink droplet flight trajectory 92 (negatively charged deflection ink droplet flight trajectory) shown in FIG. Is deflected.
[0037]
Further, the ink droplet weight and ejection speed of the preliminary ejection ink droplet 142 are set to be smaller than those of the recording ink droplet 141 and are ejected to be negatively charged. Thus, the preliminary ejection ink droplet 142 is largely deflected in the direction of the electrode 21 of the resin porous sheet 211 by the electrostatic force action due to the direction component perpendicular to the ink ejection direction of the gradient electric field, and the ink of the gradient electric field is Due to the action of the ejection direction component, it receives a force that is decelerated and returned in the opposite direction to the recording paper 60. As a result, the preliminary ejection ink droplet 142 takes the preliminary ejection ink droplet U-turn flight trajectory 93 shown in FIG. 3 and lands on the resin porous sheet 211. The landed ink immediately soaks into the resin porous sheet 211, and the soaked ink is sucked and collected from the suction hole 111 with a negative pressure.
[0038]
If the charge voltage value of the charge deflection signal for the preliminary ejection ink droplet is made higher than the charge voltage value of the charge deflection signal for the recording dot forming ink droplet, the charge amount of the preliminary ejection ink droplet is increased. The preliminary ejection ink droplets are more likely to make a U-turn, and the weight and ejection speed of the preliminary ejection ink droplets 142 can be set to the same amount without distinction from the recording ink droplets 141. As described above, since the increase in the ink viscosity in the vicinity of the nozzle hole can be suppressed even for the nozzle that has been resting for a while due to the preliminary ejection and the U-turn collection of the ink droplet, the recording dot is formed again. Even so, the recording ink droplets are also generated normally and stably, and the recording dots can be formed at the proper desired positions.
[0039]
The ink droplets that are landed on the electrode 21 of the resin porous sheet 211 are not limited to the preliminary ejection ink droplets for suppressing the increase in the ink viscosity at the nozzle holes. When it is necessary to eject ink droplets that are unnecessary for forming the recording dots, the ink droplets may be landed on the electrode 21 of the porous resin sheet 211 by performing U-turn flight control.
[0040]
As can be seen from the above description of the operation, the gradient electric field 85 is disturbed when foreign matter such as ink aggregates or paper dust adheres to the electrode 21 of the resin porous sheet 211. Such disturbance of the gradient electric field causes the landing points of the recording ink droplet 141 and the preliminary ejection ink droplet to be out of order, resulting in recording disturbance and poor recovery of the preliminary ejection ink droplet. Conventionally, in order to avoid such a problem, cleaning has been carried out carefully to remove foreign substances. Therefore, it has been difficult to reduce the effective recording speed or to ensure sufficient recording reliability and quality. On the other hand, in the configuration of the present invention, the resin porous sheet 211 is moved in the direction B (see FIG. 1) and periodically replaced with a new resin porous sheet 211. Since the porous sheet is made of resin and contains ink, the sheet can be exchanged smoothly without damaging the nozzle holes 12 and the orifice plate 11 and with little friction. Therefore, according to the present invention, the electrode 21 can be replaced before it becomes very dirty, and the cleaning time can be shortened, so that the substantial recording speed is not lowered. Further, the quality and reliability of recording can be maintained in a good state. Furthermore, the electrode 21 can be configured very simply.
[0041]
FIG. 12 is a diagram for explaining the operation when the wipe cleaning operation of the orifice 11 and the capping operation of the nozzle hole 121 are performed in the configuration of FIG. 1, and the line recording head main body 1 side is viewed from the surface of the recording paper 30. FIG.
[0042]
FIG. 12A shows the positional relationship among the recording head unit 10, the nozzle hole array 121, the resin porous sheet 211, and the window portion 22 in the recording operation state. After completion of the recording operation in this state, the resin porous sheet 211 is moved in the direction indicated by the arrow B in the same manner as in the electrode replacement, and is moved to the position shown in FIG. In this moving process, the nozzle hole 12 and the orifice plate 11 are moved while being rubbed with the surface of the resin porous sheet 211. As a result, foreign matter such as dust adhering to the nozzle hole 12 or paper dust or ink aggregates can be wiped off with the resin porous sheet 211. It is also possible to improve the cleaning effect by changing the moving speed of the resin porous sheet 211 or adding a process of moving the moving direction in the direction opposite to the arrow B.
[0043]
Further, at the time of non-printing, the state shown in FIG. 12B, that is, the state in which the nozzle hole 12 is closed with the surface of the resin porous sheet 211 is made. FIG. 13 is a partial sectional view in the vicinity of the nozzle hole 12 in the XX ′ section at this time. In this state, the vicinity of the nozzle hole 12 is closed with a resin porous sheet 211 containing ink. For this reason, there is no clogging of the nozzle hole due to drying of the nozzle hole 12, and a capping operation can be performed satisfactorily. At the time of capping, if the ink oozes out from the nozzle hole to the resin porous sheet 211, the ink supply path to the recording head unit 10 may be blocked. When resuming printing, the resin porous sheet 211 is moved in the direction B to the position shown in FIG. 12C, and a new window 22 is installed on the recording head unit 10. If the electrode window 22 used for the previous recording is still usable, the resin porous sheet 211 can be moved in the direction opposite to the arrow B, and returned to the position shown in FIG. It is.
[0044]
FIG. 5 is a diagram for explaining a second example of the present invention, and is a perspective view showing only the configuration above the recording paper 60 of FIG. The difference between this example and the example shown in FIG. 1 is that the resin porous sheet end surface portion 2111 of the window portion 22 of the resin porous sheet 211 is provided with fine positioning means for positioning with respect to the nozzle row.
[0045]
As the configuration of the positioning fine adjustment means, the position detection means for detecting the position of the nozzle hole row 121 with respect to the resin porous sheet end surface portion 2111 of the window 22 and the nozzle hole based on the information from this position detection means A moving means for finely adjusting the position of the resin porous sheet end surface portion 2111 with respect to the row 121 is provided. Here, the position detecting means for detecting the position of the nozzle hole row 121 with respect to the resin porous sheet end surface portion 2111 is an electrode position marker 221 formed on both sides of the porous sheet end surface portion 2111 of the resin porous sheet 211, An electrode position marker reading light emitting element 222 for reading the electrode position marker 221 and an electrode position marker reading light receiving element 223 are provided. Further, means for finely adjusting the position of the resin porous sheet end surface portion 2111 with respect to the nozzle hole row 121 are four places on both sides of the surface of the resin porous sheet 211 facing the line recording head main body 1. And a porous sheet position fine movement roller 216 installed on the surface, and a porous sheet position fine movement motor 215 for driving the roller.
[0046]
The operation of this configuration is as follows. After the position of the resin porous sheet end surface portion 2111 of the window portion 22 with respect to the line recording head main body is substantially aligned by driving the porous sheet moving motor 214, the electrode position marker 221 is moved to the electrode position marker reading light emitting element 222. While reading by the electrode position marker reading light receiving element 223, the porous sheet position fine movement motor 215 is driven to adjust the movement and tension of the porous sheet. Thereby, the position of the nozzle hole row 21 with respect to the porous sheet end surface portion 2111 of the window portion 22 can be installed with accuracy so that the predetermined positional relationship described above is obtained. In particular, even when the material of the resin porous sheet 211 is a stretchable material, the fine adjustment rollers at the four corners are independently driven and controlled, and the tension applied to the resin porous sheet 211 is adjusted. By adjusting the expansion and contraction of the seat 211, a desired installation accuracy can be ensured.
[0047]
6 and 7 are diagrams for explaining a third example of the present invention. FIG. 6 is a plan view of the recording paper 30 as viewed from the line recording head main body 1 side, and FIG. 7 is a partial sectional view of the vicinity of the nozzle hole 12 in the XX ′ section of FIG. The difference between this example and the example shown in FIG. 1 is that a thin metal plate 218 made of stainless steel or the like is bonded to the surface of the resin porous sheet 211, and the electrode 21 on the resin porous sheet end surface portion 2111 side of the window portion 22 Only the corresponding part is exposed, and only the porous resin sheet 211 is formed.
[0048]
According to this example, the deflection electrode operation and the ink recovery operation according to the present invention described in the example of FIG. 1 can be performed, and the metal thin plate 218 is attached to a portion other than the portion corresponding to the electrode 21 of the resin porous sheet 211. Therefore, the resin porous sheet 211 is reinforced, and the dimensional change due to the tension and temperature change can be reduced, so that the setting accuracy of the resin porous sheet end surface portion 2111 with respect to the nozzle hole 12 can be improved. Is possible.
[0049]
In addition, even when the resin porous sheet shown in FIGS. 6 and 7 and the metal thin plate described above are bonded, the wiping operation and the capping operation described in FIGS. 12 and 13 can be performed. It is. In this configuration, since the resin porous sheet 211 is reinforced by the metal thin plate 218, the resin porous sheet 211 can be strongly pressed against the orifice plate surface, or the moving speed and acceleration can be increased. it can. Furthermore, as shown in FIGS. 14 and 15, it is possible to improve the sealing property even when capping.
[0050]
8 and 9 are diagrams for explaining a fourth example of the present invention. FIG. 8 is a plan view of the recording paper 30 as seen from the line recording head main body 1 side, and FIG. 9 is a partial sectional view of the vicinity of the nozzle hole 12 in the XX ′ section of FIG. In this example, the orifice plate 11 is in contact with a metal base plate 217 made of stainless steel or the like, and the porous resin sheet 2114 is superimposed on the metal base plate 217 made of stainless steel or the like. It has become. The metal base plate 217 is attached in close contact with the orifice plate 11, and only the resin porous sheet 2114 moves in the B direction and is replaced. The gradient electric field 85 is formed by the metal base window end surface portion 2113 of the window portion 22 and the resin porous sheet end surface portion 2112. The preliminary ejection ink droplets land on the resin porous sheet 2114 in the vicinity of the end face 2112 and pass through the suction path 114 passing through the metal base plate 217, and further through the suction path 112 of the inkjet head. It is sucked and collected by a negative pressure generated by a negative pressure generating source (not shown). According to this example, even if the resin porous sheet end surface portion 2111 slightly deviates in the direction opposite to B with respect to the metal base window end surface portion 2113, the thickness of the resin porous sheet 2114 is set to be thinner than the metal base. Therefore, the fluctuation of the gradient electric field 85 can be reduced. Therefore, it is possible to improve the deflection accuracy compared to the example of FIG.
[0051]
FIG. 10 is a perspective view of the vicinity of the recording head unit for explaining a fifth example of the present invention. In this example, the electrode window 22 formed in the metal base plate 217 and the resin porous sheet 311 is independently attached to each recording head unit 10 here, and the resin porous sheet 311 is replaced by the recording head. The point is that it is done for each unit 10. A metal base 317 is overlapped and fixed on the resin porous sheet 311. The positioning accuracy of the resin porous sheet end surface portion 3111 and the metal base window end surface portion 3113 with respect to the nozzle array 121 is determined by the positioning pin holes 23 formed in the orifice plate 11, the metal base 317, and the resin porous sheet 311. And is secured by positioning pins 24. According to this example, the cost of consumables when exchanging the porous resin sheet can be reduced compared to the case of a sheet roll porous resin sheet. It is suitable for a printer with a low rate. In this example, one recording head unit 10 is configured to correspond to one of the resin porous sheets provided with only one window 22, but 2 to 10 recordings are possible. If a resin porous sheet having a required number of window portions 22 provided for the head unit 10 is produced, it can be expanded to a plurality.
[0052]
FIG. 11 is a perspective view of the vicinity of the recording head unit for explaining a sixth example of the present invention. This example is a modification of the fifth example, and the difference is that the electrode 41 is not formed as one side of the window, but the electrode / ink receiving plate 219 is arranged along the nozzle row 121. It is in. The electrode / ink receiving plate 219 includes a metal base window end surface portion 4113 that abuts the orifice plate 11 and a resin porous sheet end surface portion 4111, which form a gradient electric field. The accuracy of the arrangement of the resin porous sheet end face portion 4111 and the metal base window end face portion 4113 with respect to the nozzle row 121 is determined by the positioning of the metal base window end face portion to the positioning pin 24 mounted in the positioning pin hole 23 formed in the orifice plate. It is ensured by abutting 4113 or a resin porous sheet end face portion 4111. Since the deflection electrode of this example is simple, it can be provided at low cost.
[0053]
FIG. 16 is a plan view showing another example of the configuration of the resin porous sheet. A non-porous sheet portion 5112 having no porous portion is provided on both sides of a region where the window portion 22 corresponding to the number of the recording head units 10 of the resin porous sheet 511 is formed. Thereby, even when the spread of the ink soaked into the porous sheet is large, the spread can be stopped, and the unused portion of the resin porous sheet 511 can be protected. A wipe cleaning window portion 25 is formed on the surface of the resin porous sheet 511 that contacts the orifice plate 11. The window portions are formed with a narrower width interval than the window portion 22. Thereby, the effect of rubbing the orifice plate 11 is strengthened, and the effect of cleaning the surface of the orifice plate 11 can be improved.
[0054]
As described above, in each example of the present invention, the material of the porous sheet has been described as a resin. However, any material having the same ink absorptivity, hardness, strength, and workability as the resin can be applied to the present invention. Is possible. In addition, in a porous sheet made of a hard material such as a ceramic porous sheet, sliding the nozzle surface with the porous sheet may damage the nozzle surface. Although not suitable for the embodiment according to the present invention that slides and cleans the vicinity of the nozzle hole, the example of the present invention in which a porous sheet is impregnated with ink to form an electrode, the nozzle hole row is blocked, and the nozzle hole is capped. It is applicable to the embodiments of the present invention. In the case of carrying out the present invention using a porous sheet made of such a hard material, it is possible to avoid damage to the nozzle surface by moving it away from the nozzle surface when moving the porous sheet.
[0055]
【The invention's effect】
According to the present invention, when the electrode is very dirty, it can be easily replaced with a new electrode, and the cleaning time can be shortened, so that the substantial recording speed is not lowered, and the recording quality and reliability are good. Can be maintained. Also, the electrode can be configured very simply. Furthermore, since the nozzle hole cleaning function and the capping function can be realized simply, a high-speed inkjet printer capable of recording a high-quality image with high reliability can be provided.
[Brief description of the drawings]
FIG. 1 is a perspective view and a control block diagram showing a schematic configuration of a deflection-type on-demand line-type ink jet printer provided with a deflection electrode of the present invention.
FIG. 2 is an enlarged perspective view from the nozzle hole side of the recording head unit.
FIG. 3 is a partial cross-sectional view showing a state in which a recording unit including a recording head unit is cut perpendicularly to a recording sheet along a section XX ′ in FIG.
4 is an explanatory diagram showing an equipotential surface of the recording head unit of FIG. 3. FIG.
FIG. 5 is a perspective view showing only the configuration above the recording paper 60 of a deflection-type on-demand type line inkjet printer as a second example of the present invention.
FIG. 6 is a plan view of the line recording head body side as viewed from the surface of a recording sheet according to a third example of the present invention.
7 is a partial cross-sectional view of the vicinity of a nozzle hole in the XX ′ cross section of FIG. 6;
FIG. 8 is a plan view of the line recording head main body side as viewed from the surface of a recording paper 30 according to a fourth example of the present invention.
9 is a partial cross-sectional view of the vicinity of a nozzle hole 12 in the XX ′ cross section of FIG. 8;
FIG. 10 is a perspective view of the vicinity of a recording head unit for explaining a fifth example of the invention.
FIG. 11 is a perspective view of the vicinity of a recording head unit for explaining a sixth example of the invention.
FIG. 12 is an operation explanatory diagram when performing a wipe cleaning operation and a capping operation.
13 is a cross-sectional view taken along the line XX ′ in FIG.
14 is an explanatory diagram showing a capping state in the configuration of FIG. 6. FIG.
15 is a cross-sectional view taken along the line XX ′ in FIG. 14 (b).
FIG. 16 is a plan view showing another example of the structure of the resin porous sheet.
[Explanation of symbols]
1 Line recording head
10 Recording head unit
11 Orifice plate
111 Suction hole
112 Suction channel
114 Metal base plate suction path
12 Nozzle holes
121 Nozzle hole array
13 Orifice plate pin hole
14 Ink drops
141 Ink drops for recording
142 Preliminary ink drops
20 Head mounter
21 electrodes
211 Resin porous sheet
2111 End face of porous resin sheet
2112 Non-porous sheet
2113 Metal base window edge
212 Porous sheet roll supply unit
213 Porous sheet roll take-up part
214 Porous sheet moving motor
215 Porous sheet position fine movement motor
216 Porous sheet position fine movement roll
217 metal base plate
218 sheet metal
219 Deflection electrode and ink receiving plate
22 Window
221 Electrode window position marker
222 Light emitting element for electrode position marker reading
223 Photodetector for electrode position marker reading
23 Electrode window positioning pin hole
24 Electrode window positioning pin
25 Wipe cleaning window
27 Ink receiving absorber
30 Paper back electrode
33 Purge suction tube
40 Charge deflection control signal generation circuit
41 Charge deflection signal generation circuit
42 Rear electrode driver circuit
43 Pre-discharge signal generation circuit
50 Ink droplet ejection control signal generator
51 Recording signal creation circuit
52 Timing signal generator
53 Drive pulse generation circuit
54 Driver circuit
56 Pre-discharge signal generation circuit
60 Recording paper
70 recording dots
80 equipotential surface
85 Gradient electric field
90 Unpolarized ink droplet flight trajectory
91 Positively charged deflected ink droplet flight trajectory
92 Negatively charged deflection ink droplet flight trajectory
93 Preliminary ejection ink droplet U-turn flight trajectory
A Recording paper feed direction
B porous sheet moving direction
C Purge suction pipe moving direction
D Purge negative pressure suction direction
E Ink collection and porous sheet suction direction

Claims (8)

An electrode disposed near the ink ejected from the nozzle hole is separated as ink particles, comprising a back electrode provided on the back of the recording paper, the deflection in the ink particles in the ejection direction perpendicular to the direction of the ink particles In an inkjet recording apparatus that forms an inclined deflection electric field that gives force and changes the ejected ink particles to an arbitrary position.
A resin porous sheet having end face portions arranged along the nozzle hole row is movably installed on the orifice surface where the nozzle hole row in which a plurality of nozzle holes are arranged is formed, so that the nozzle holes are exposed. An ink jet recording apparatus, wherein the porous resin sheet is impregnated with ink to form an electrode. The inkjet recording apparatus according to claim 1, wherein
The ink jet recording apparatus, wherein the resin porous sheet also serves as an ink receiver for landing ink droplets unnecessary for recording. The inkjet recording apparatus according to claim 1 or 2,
A supply unit that supplies the resin porous sheet and a winding unit that collects the used resin porous sheet are provided, and the resin porous sheet can be replaced by moving the resin porous sheet. Inkjet recording apparatus. The inkjet recording apparatus according to claim 3.
An ink jet recording apparatus, wherein when moving the resin porous sheet, the nozzle surface is slid by the resin porous sheet to clean the vicinity of the nozzle hole. The inkjet recording apparatus according to claim 1 or 2,
An end face portion of the resin porous sheet is one side of a window portion formed on the resin porous sheet so that the nozzle row is exposed . The inkjet recording apparatus according to claim 5.
An ink jet recording apparatus, wherein a nozzle hole row is closed by a non-window portion of the resin porous sheet and the nozzle holes are capped. An electrode disposed near the ink ejected from the nozzle hole is separated as ink particles, comprising a back electrode provided on the back of the recording paper, the deflection in the ink particles in the ejection direction perpendicular to the direction of the ink particles In an ink jet recording apparatus that deflects ejected ink particles to an arbitrary position by forming an inclined deflection electric field that gives force,
The nozzle holes are arrayed been nozzle hole rows on the orifice surface formed, wherein the nozzle hole porous resin sheet configured to arrange the end face along the columns so that the nozzle hole is exposed was installed movably, an ink jet recording apparatus said porous resin sheet ink impregnated in the electrode and without, except the electrode corresponding portion, characterized in that coated with metal thin film. An electrode disposed near the ink ejected from the nozzle hole is separated as ink particles, comprising a back electrode provided on the back of the recording paper, the deflection in the ink particles in the ejection direction perpendicular to the direction of the ink particles In an ink jet recording apparatus that deflects ejected ink particles to an arbitrary position by forming an inclined deflection electric field that gives force,
A metal base plate is mounted along the nozzle hole row so as to expose the nozzle hole on the orifice surface where the nozzle hole row in which a plurality of nozzle holes are arranged is formed , and overlaps the metal base. An ink jet recording apparatus comprising: a resin porous sheet laminated; and the resin porous sheet is impregnated with ink to form an electrode.

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