JP2008126576A - Inkjet recorder, and recovering method for inkjet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recorder which always maintains a good ink discharge performance irrespective of kinds of ink discharged therefrom. <P>SOLUTION: Ink sticking to a vicinity of discharge port of a recording head 3 is removed through a wiping recovery treatment using a wiping member 10. On this occasion, the wiping recovery treatment is controlled according to the type of ink supplied to the recording head 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an inkjet recording apparatus that performs recording using a recording head that includes a plurality of ejection ports that eject ink, and a recovery method that recovers the ejection performance of the recording head of the inkjet recording apparatus.

  In an ink jet recording type recording apparatus that discharges ink droplets to form an image on a recording medium, a plurality of fine discharge ports and liquid passages communicating with them (hereinafter referred to as nozzles) are formed. The recording head used is used. In this ink jet recording apparatus, bubbles or dust may be mixed into the ink in the liquid path from the ejection port, or the ink may be thickened or fixed due to evaporation of the solvent contained in the ink. In this case, the ejection performance of the recording head is significantly reduced. That is, a landing error of ejected ink droplets, non-ejection of ink droplets, etc. occur in the recording head. In order to avoid such a drop in the ejection performance of the recording head, conventionally, a process of discharging the thickened ink or solidified ink generated in the nozzle and refreshing the ink in the nozzle is performed. Hereinafter, this process is referred to as a discharge recovery process.

  As one form of the means for performing the discharge recovery process, there is one provided with a cap capable of covering the discharge port forming surface of the recording head and a pump communicating with the cap. In this embodiment, the ejection port forming surface is covered with a cap, and a negative pressure is generated in the cap by a pump to forcibly suck out ink from the nozzles of the recording head. For this reason, this discharge recovery process is also referred to as a suction recovery process.

  Further, as a form of the discharge recovery process, there is a form in which the ink discharge energy generating element provided in the nozzle is driven in a state where the cap faces the discharge port forming surface. According to this, ink having increased viscosity in the cap, ink containing bubbles and dust, and the like are ejected into the cap, and the ink in the nozzle can be refreshed.

  By the ejection recovery process, the ink received by the ejection recovery device including the cap, the pump, and the waste ink tube communicating therewith is guided to the waste ink tank. This is performed by a so-called idle suction operation in which the pump is operated with the cap opened to the atmosphere.

  On the other hand, adhesion of dust such as ink and paper dust around the ejection port on the ejection port forming surface of the recording head is also a factor that deteriorates the ink ejection performance. In order to eliminate this cause of ejection failure, conventionally, a recovery process (hereinafter referred to as a wiping recovery process) of wiping the ejection port forming surface with a blade is also performed.

  Further, in such a wiping recovery process, thickened ink, dust, or the like may be fixedly deposited on the blade by the wiping operation. When ink or dust adheres to the blade, the recovery effect of the blade is significantly reduced. Therefore, a method has been proposed in which ink is ejected from the recording head onto the blade to remove thickened ink, dust, and the like accumulated on the blade (see Patent Document 1). Further, Patent Document 2 discloses a device that removes ink adhering to a blade by performing preliminary discharge while wiping the blade. Here, the preliminary discharge means discharge of ink that does not contribute to image formation and is performed for the purpose of keeping the discharge performance of the nozzles of the recording head in a good state at the start of the recording operation.

  Japanese Patent Application Laid-Open No. H10-228561 also discloses that a wet condition is maintained by applying a head cleaning liquid to a blade to improve cleaning properties.

Japanese Patent Laid-Open No. 7-164463 Japanese Patent Laid-Open No. 2-95862 Japanese Unexamined Patent Publication No. 6-79879

  However, in recording using a recording apparatus, recording may be performed by ejecting a large number of inks, such as recording in a large area, continuous recording, or recording at a high recording rate (high duty). . Further, the optimum conditions for the ejection recovery processing means differ depending on the type of ink. In this case, according to the technique described in the above-mentioned patent document, the ink tends to remain in a state where the ink is fixed or thickened on the discharge port forming surface of the recording head or the blade. For this reason, these techniques may not be able to sufficiently remove ink from the ejection port forming surface of the recording head.

That is, in the ink jet recording apparatus described in the above patent document, the recovery operation by the blade is always driven a certain number of times. For this reason, if the ink remaining on the ejection port forming surface or the blade is in a state where it is difficult to remove such as fixation and thickening, it may not be able to be sufficiently removed. In particular, since the blade to which the ink is fixed is in a state where the ink removing function is lowered, the ink cannot be sufficiently removed from the ejection port forming surface.
As described above, in the technique described in the above-mentioned patent document, the ejection performance of the recording head may not be kept good, and the ejection failure of the recording head and the deterioration of landing accuracy have not been sufficiently solved.

  The present invention has been made paying attention to the problems of the prior art described above, and an object of the present invention is to provide an ink jet recording apparatus that can always maintain good ink ejection performance regardless of the type of ink ejected.

  In order to solve the above problems, the present invention has the following configuration.

  That is, a first aspect of the present invention is an ink jet recording apparatus that performs recording using a recording head having an ejection port for ejecting ink and can change the type of ink ejected from the recording head, Wiping recovery means for removing ink adhering to the periphery of the ejection port of the recording head by wiping recovery processing using a wiping member, and wiping recovery processing of the wiping recovery means according to the type of ink supplied to the recording head And a control means for controlling related operations.

The second aspect of the present invention is a recovery method in an ink jet recording apparatus in which recording is performed using a recording head having an ejection port for ejecting ink and the type of ink ejected from the recording head can be changed. A wiping recovery step for removing ink adhering to the periphery of the ejection port of the recording head by a wiping recovery process using a wiping member;
And a control step of controlling an operation related to the wiping recovery process of the wiping recovery means according to the type of ink supplied to the recording head.

  According to the present invention, by changing the operation related to the wiping recovery process using the wiping member according to the type of ink, the ink remaining on the discharge port forming surface of the recording head is reduced regardless of the type of ink. It becomes possible. For this reason, the ink ejection performance of the recording head can always be kept in a good state, and ejection defects, landing errors, etc. of the recording head can be reduced.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a plan view showing an ink jet recording apparatus according to an embodiment of the present invention.
In FIG. 1, reference numeral 1 denotes a recording apparatus main body provided with various mechanism units including a conveyance system unit (not shown) for recording paper (recording medium). The recording apparatus main body 1 and an after-mentioned control system mounted on the recording apparatus main body 1 constitute an ink jet recording apparatus. Note that the ink jet recording apparatus in the present embodiment is a serial type ink jet recording apparatus. In this serial type recording apparatus, the recording medium is intermittently conveyed in the Y direction by the conveying system unit, and the recording head 3 is in a direction orthogonal to the Y direction (sub-scanning direction) that is the conveying direction of the recording medium. The recording operation is performed while moving in the direction (main scanning direction). Further, the recording apparatus main body 1 shown in FIG. 1 has a configuration in which the size in the X direction is increased so that recording can be performed on a relatively large recording medium (for example, A1 size).

  In FIG. 1, reference numeral 2 denotes a carriage. A plurality (six in this embodiment) of recording heads 3 and an in-tank (not shown) supplied to the recording heads 3 are detachably mounted on the carriage 2. That is, the type of ink ejected from the recording head can be changed. The carriage 2 reciprocates along with the recording head 3 along a direction (X direction) orthogonal to the recording medium conveyance direction. Specifically, the carriage 2 is supported so as to be movable along a guide shaft 4 disposed along the X direction, and is fixed to an endless belt 5 that moves substantially parallel to the guide shaft 4. The endless belt 5 reciprocates by the driving force of a carriage motor (CR motor), thereby reciprocating the carriage 2 in the X direction (main scanning direction).

  Further, as shown in the schematic diagram of FIG. 2, the recording head 3 includes a plurality of discharge ports 3a formed on the discharge port forming surface 3b and a plurality of liquid paths formed corresponding to the individual discharge ports 3a. (Not shown) and a common liquid chamber (not shown) for supplying ink to the plurality of liquid paths are formed. In each recording head 3 of the present embodiment, 1280 ejection ports 3a are arranged at a density of 1200 dpi (dots / inch) in the sub-scanning direction. In FIG. 2, I1 indicates ink discharged from the discharge port 3a, and I2 indicates ink fixed to the blade 10.

  Furthermore, an energy generating element that generates ejection energy for ejecting ink from the ejection port 3a is disposed in each liquid path of the recording head 3. In this embodiment, an electrothermal converter that heats the ink locally to cause film boiling and ejects the ink by the pressure is used as the energy generating element. However, the present invention is not limited to this, and an electromechanical conversion element can also be used. In the following description, the discharge port 3a and the liquid path are collectively referred to as a nozzle.

  The recording head mounted on the carriage 2 is supplied from a plurality of ink tanks individually storing a plurality of types of inks containing different color materials. In this embodiment, in addition to cyan, magenta, yellow, and black inks, a total of six colors of ink are accommodated, including light cyan and light magenta inks used to reduce the granularity of the image to be formed. These six ink tanks are mounted on the carriage 2. Each ink tank mounted on the carriage 2 is connected to an ink supply port of the corresponding recording head 3 to supply ink to each recording head.

  Reference numeral 7 denotes a recovery processing device for keeping the ink ejection performance from each ejection port 3a of the recording head 3 in a good state. The recovery processing device 7 is held and fixed at a predetermined position of the recording apparatus main body 1. The recovery processing device 7 includes suction recovery mechanisms 7A and 7B, a lifting mechanism (not shown) that lifts and lowers them, a wiping recovery device 9, and an ink receiving box 8.

  The suction recovery mechanisms 7A and 7B perform a suction recovery process that is a form of the recovery process. Here, the suction recovery process refers to a process of replacing ink in a nozzle with ink in a state suitable for ejection by forcibly sucking ink from a plurality of nozzles formed in the recording head. Specifically, the suction recovery mechanisms 7A and 7B cover the discharge port forming surface 3b (see FIG. 2) with a cap, and generate a negative pressure in the cap by a pump (not shown) communicating with the cap. The ink is forcibly sucked from the ejection port 3a by the negative pressure. Each of the suction recovery mechanisms 7A and 7B performs suction recovery processing on three different recording heads 3.

  Another form of recovery processing is preliminary ejection. This preliminary ejection is a process of keeping the ink in each nozzle of the recording head in a state suitable for ejection by ejecting ink that does not contribute to the recording operation to the ink receiving box 8. This preliminary discharge is performed mainly at the start or end of the recording operation. Further, it may be performed at predetermined intervals during the recording operation.

  Further, the wiping recovery device (wiping recovery means) 9 is provided at a position that can face the end position of the moving path of the recording head 3 (for example, the home position of the recording head) in the vertical direction. The wiping recovery mechanism 9 includes a wiping mechanism (wiping means) that wipes the periphery of the ejection port of the recording head, that is, the ejection port forming surface 3b, using a wiping member (blade) 10. In addition, the wiping recovery mechanism 9 includes a cleaning liquid application mechanism (liquid application unit) 14 that applies (applies) a cleaning liquid (liquid) to the blade 10. As shown in FIGS. 2 and 3, the wiping mechanism includes a wiping member (blade) 10 disposed along a surface substantially orthogonal to the discharge port forming surface 3b of the recording head 3, and a blade holder 10a for holding the wiping member. And a wiper moving mechanism that moves the nozzles in the arrangement direction of the discharge ports. The cleaning liquid application mechanism 14 will be described later.

  FIG. 4 is a block diagram showing a configuration of a control system (control means) mounted on the recording apparatus main body 1 of the ink jet recording apparatus according to this embodiment. In FIG. 3, reference numeral 100 denotes a main control unit. The main control unit 100 includes a CPU 101, a ROM 102, a RAM 103, an input / output port 104, and the like. Here, the CPU 101 executes processing operations such as calculation, control, discrimination, and setting, and the ROM 102 stores a control program to be executed by the CPU 101 and the like. The RAM 103 is used as a buffer for storing binary print data representing ink ejection / non-ejection and a work area for processing by the CPU 101.

  The input / output port 104 includes drive circuits 105, 106, 107, and 109 such as a transport motor (LF motor) 112, a carriage motor (CR motor) 113, a recording head 3, and a recovery processing device 7 in the transport unit described above. Is connected. Further, the input / output port 104 is connected with other sensors such as a head temperature sensor (head temperature detecting means) 114 for detecting the temperature of the recording head and an encoder sensor 110 fixed to the carriage 2. . The main control unit 100 is connected to a host computer 116 via an interface circuit 111.

Reference numeral 115 denotes an ink information reading unit that reads information of an ink tank mounted on the carriage 2. Each ink tank is provided with a memory chip that stores information indicating the type of ink contained therein, information indicating the remaining amount of ink, and the like. The ink information reading unit 115 reads information stored in the memory chip of the ink tank mounted on the carriage 2 and sends the information to the main control unit 10. The main control unit 10 determines the type of ink that can be ejected from the recording head based on the received information, and executes a predetermined recovery operation based on the determination result.
The carriage 2 in the present embodiment is provided with one mounting portion as a mounting portion for mounting a black ink tank. For this reason, when the black ink is changed from mat black to photo black, the mat black ink tank already mounted is removed and the photo black ink tank is mounted. At this time, whether the photo black ink tank or the matte black ink tank is mounted on the black mounting portion is determined based on the information of the memory chip provided in each tank.

  However, some carriages 2 have dedicated mounting portions for the matte black ink tank and the photo black ink tank. In this case, the ink that can be ejected from the recording head 3 is determined based on information on whether or not an ink tank is attached to each attachment portion, information on the remaining amount of ink in the attached ink tank, and the like. Further, the type of ink used by the main controller 100 is determined based on the determination result and the set recording mode. In this case, the recording mode can be selected according to the recording medium to be used (for example, a plain paper mode, a glossy paper mode, etc.) or a recording image mode (a text image mode, a photographic image mode, etc.). is there.

Next, a recording operation and blade recovery processing executed by the ink jet recording apparatus having the above configuration will be described.
First, the outline of the recording operation will be described.
When recording data is received from the host computer 116 via the interface, the recording data is developed in a buffer of the RAM 103. When a recording operation is instructed, a transport unit (not shown) operates to transport the recording medium to a position facing the recording head 3. Here, the carriage 2 moves along the guide shaft 4 in the main scanning direction (X direction). As the carriage 2 moves, ink droplets are ejected from the recording head 3 and an image for one band is recorded on the recording paper. Thereafter, the recording unit conveys the recording medium by one band in the direction orthogonal to the carriage 2 (sub-scanning direction). By repeating the above operation, a predetermined image is formed on the recording medium.

  The position of the carriage 2 is detected by counting the pulse signal output from the encoder sensor 110 as the carriage 2 moves by the main control unit 100. That is, the encoder sensor 110 outputs a pulse signal to the main control unit 100 by detecting the detection units formed at regular intervals on the encoder film 6 (see FIG. 1) arranged along the main scanning direction. The main controller 100 detects the position of the carriage 2 by counting the pulse signals. The carriage 2 is moved to the home position and other positions based on a signal from the encoder sensor 110.

Next, the wiping recovery process executed by this embodiment will be described.
When performing the wiping recovery process, first, the carriage 2 is moved, and the ink is ejected from the ejection port 3a with the ejection port forming surface 3b of the recording head 3 facing the wiping mechanism 9 as shown in FIG. Thereafter, the wiping mechanism 9 is raised by the lifting mechanism of the recovery device 7, and the blade 10 is brought into contact with the ejection port forming surface 3b of the recording head. Here, the wiping mechanism 9 moves the blade 10 in the nozzle array direction (Y direction) of the recording head 3, and dust and ink adhering to the ejection port forming surface 3 b are wiped by the blade 10 and removed. At this time, the ink adhering to the ejection port forming surface 3 b adheres to the blade 10. The wiping recovery process is performed at a predetermined timing set in advance, for example, after the suction recovery process is performed, or after a certain number of recording operations are completed.

  In the conventional wiping recovery process, the blade 10 always performs a certain number of wiping or application of cleaning liquid to the wiping and ink ejection to the blade with respect to the ejection port forming surface 3b.

  For this reason, when the amount of ink adhering to the ejection port forming surface 3b and the blade 10 is below a certain amount, the ink may be appropriately removed from the ejection port forming surface 3b. However, when the number of ink droplets ejected from the recording head is large, such as when recording an image with a high recording rate and a large area, ink and ink mist remaining on the ejection port formation surface 3b during ejection are present. Increase. For this reason, a lot of ink adheres to the discharge port forming surface 3b and the blade 10, and the ink may not be sufficiently removed from the discharge port forming surface 3b by the conventional wiping recovery. However, if the number of wipings is set assuming the maximum number of ink ejections in the recording head, that is, the maximum amount of ink adhering to the ejection port formation surface, it is possible to properly remove the ink. However, in this case, if the number of ejected inks is small, wiping more than necessary is performed, and new disadvantages such as a decrease in recording speed and significant wear on the ejection port forming surface and blade occur. .

  Further, when the discharge operation has been stopped for a long period of time, or when the temperature of the discharge port forming surface 3b is increased due to ink discharge, the ink attached to the blade 10 and the discharge port forming surface 3b is increased in viscosity. Or it will be in the state which adhered. This has been confirmed to be particularly noticeable when an ink that tends to thicken, such as matte black ink, is used. If the ink adhering to the ejection port forming surface 3b and the blade 10 is in a thickened or fixed state, the ink removal by the blade 10 becomes more difficult.

  Therefore, in this embodiment, the ink information reading unit 115 controls the increase / decrease in the number of wiping of the blade 10, the wiping operation speed, and the number of ink ejected onto the blade in accordance with the exchange of the ink type. That is, the CPU 101 of the main control unit 100 determines whether or not the ink type has been changed based on the ink replacement information output from the ink information reading unit 115.

  Here, when the viscosity of the ink to be replaced is lower than that of the ink before the replacement, the blade 10 is made to discharge the ink by a predetermined first discharge number. Thereafter, the protruding blade 10 is wiped by a predetermined first wiping number. Wiping at this time is performed at the first wiping speed. When the viscosity of the ink to be exchanged is higher than that of the ink before the exchange, the number of ejections to the blade 10 is ejected by the second ejection number larger than the first ejection number, and the blade 10 is Wiping is performed by a second wiping number that is larger than the first wiping number. That is, the amount of liquid supplied from the liquid applying means to the wiping member is increased or decreased according to the viscosity of the ink ejected from the recording head. The wiping at this time is performed at a second wiping speed that is slower than the first wiping speed. That is, the wiping operation speed performed by the wiping member is reduced in accordance with the viscosity of the ink ejected from the recording head as compared with the case of ejecting the ink having a high viscosity.

  Thus, in this embodiment, the operation related to the wiping recovery process of the wiping recovery means is controlled according to the type of ink supplied to the recording head. That is, the number of ink droplets ejected to the blade 10, the number of wipings by the blade 10, and the wiping speed are changed in two stages depending on whether or not the ink type has been replaced. For this reason, even when the ink viscosity is high and a large amount of ink adheres to the blade 10, wiping recovery can be performed in a state where the ink adhering to the blade 10 is sufficiently dissolved by discharging a large number of ink droplets. . Moreover, since the wiping by the blade 10 is performed many times and the wiping is performed slowly, the ink attached to the ejection port forming surface 3b and the blade 10 can be reliably removed. Further, when the ink viscosity is low, the wiping process is not excessively performed, and wear of the ejection port forming surface 3a of the recording head 3 and the blade 10 can be reduced.

  In the present embodiment, at least one kind of ink that is relatively hard to increase in viscosity, such as light cyan or cyan, is ejected to the blade 10. For this reason, the ink adhering to the blade 10 and the discharge port forming surface can be more easily dissolved, and the wiping process performed thereafter can be performed more reliably. In this embodiment, the cleaning liquid is applied to the blade 10 by using the scraper 15 that can contact the blade 10, thereby facilitating the dissolution of the ink adhering to the blade 10 and the discharge port forming surface in the same manner. Can do. For this reason, it becomes possible to perform the wiping process performed thereafter more reliably.

Hereinafter, the procedure of the recovery process executed in the present embodiment will be described more specifically based on the flowchart of FIG.
The flowchart of FIG. 4 shows a recovery processing procedure when ink is ejected onto the blade 10 in the above embodiment.
This procedure is an example of a recovery operation that is performed from when the ejection port forming surface 3b of the recording head 3 is covered with a cap until the recording operation is started.
First, the recovery processing device is lowered by its lifting mechanism (step 1). At this time, the blade is in a position where it can move forward and backward in the wiping direction (Y1 and Y2 directions) without contacting the ejection port forming surface 3b of the recording head 3 by the operation of the wiping mechanism.

  There is a possibility that ink having high viscosity is attached in a thickened or fixed state to a part of the blade 10 that has repeatedly been wiped by the previous recovery operation. For this reason, the carriage 2 and the blade 10 are moved to a position where a light cyan ink or cyan ink having a low viscosity can be directly ejected to the blade with respect to the thickened or adhered ink adhering to the blade 10 (step 2).

Next, the blade 10 is advanced by the wiping mechanism while discharging light cyan ink or cyan ink from the recording head 3 to the blade 10. Then, light cyan ink or cyan ink is directly ejected onto the blade 10 (steps 3, 4, and 5). Thereafter, at the same time as the blade 10 starts to move backward, light cyan ink or cyan ink is again directly discharged onto the blade 10 (steps 6, 7, and 8).
The number of ink ejected to the blade 10 is changed according to the ink type information received from the ink information reading unit 115 as described above. That is, discharge is performed with the first discharge number or the second discharge number.

  Next, the carriage 2 is returned to the home position (step 9), and the recovery processing device 7 is raised by the lifting mechanism (step 10). Here, the blade 10 is moved forward and backward to execute a wiping recovery process (step 11). The number of wipings in the wiping recovery process is also changed according to the ink type information received from the ink information reading unit 115. That is, when the viscosity of the replaced ink becomes low, for example, when the matte black is replaced with the photo black as black ink, the wiping is performed by the first wiping number. When the viscosity of the ink to be replaced becomes high, for example, when the photo black is replaced with matte black, the blade 10 is wiped by the second wiping number. Further, the wiping speed in the wiping recovery process is also changed according to the ink type information received from the ink information reading unit 115. That is, when the viscosity of the ink to be replaced becomes low, the blade is wiped at the first wiping speed. When the viscosity of the ink to be replaced becomes high, the blade 10 is wiped at the second wiping speed.

  When the wiping operation is completed, the recovery processing device 7 is lowered (step 12), the blade 10 is retracted to the original position (step 13), and the idle suction operation is performed (step 14). This empty suction operation is a process performed to guide ink received in a cap, a pump, and a waste ink tube communicating with these to a waste ink tank (not shown). This empty suction operation is performed by operating the pump with the cap open to the atmosphere. After this idle suction operation is completed, a normal recording operation is started (step 15).

  As described above, in the above embodiment, when the type of ink is changed, the level of the viscosity of the ink is determined, and the number of wiping operations, the wiping speed, and the ink ejection to the blade 10 are determined according to the determination result. The case of changing the number has been described as an example. However, depending on the use conditions or use environment of the apparatus, only the number of wiping operations, only the wiping speed, or only the number of ink ejections to the blade 10 may be changed based on the above determination result. Also in this case, improvement in recovery performance can be expected compared to the conventional case.

  In the above description, the wiping number, speed, and / or number of ink ejected onto the blade 10 are changed in two stages according to the viscosity of the ink to be replaced. However, the number of wiping, the wiping speed, and / or the number of ink discharged to the blade 10 may be changed in two or more stages or continuously according to the viscosity of the ink.

  In the above embodiment, when the ink is replaced, the level of the ink viscosity is determined. However, it is also effective to determine the physical properties other than the ink viscosity as the type of ink. That is, in the above-described embodiment, the viscosity is focused on as a characteristic of the ink that easily adheres to the blade 10 or the ejection port forming surface 3b of the recording head. However, the ink composition other than the viscosity is focused on as a characteristic that the ink is easily solidified. The wiping recovery may be controlled.

  Furthermore, it is possible to change the wiping number, speed, and / or number of ink discharged to the blade 10 in consideration of not only the ink characteristics but also the head temperature of the recording head or the number of ink discharged. It is.

Further, in the operation shown in the flowchart of FIG. 5, ink is ejected when the blade 10 moves in both forward and backward directions in steps 4 and 7. However, if the ink adhering to the blade can be dissolved only by the ink ejection operation in the movement in one direction of the blade, the movement of the blade for dissolving the adhering ink may be performed only in one direction.
Moreover, although the said embodiment described the case where the recovery processing apparatus had an raising / lowering mechanism, it is applicable also to the apparatus which does not have an raising / lowering mechanism.

  By the way, in the above-described embodiment, the case where the blade 10 ejects ink in the wiping recovery operation has been described as an example. However, the present invention is not limited to this, and the ink fixed or thickened on the blade 10 can be obtained by simply applying the cleaning liquid from the scraper 15 to the blade 10 without discharging the ink onto the blade 10. It can be removed.

This cleaning liquid application mechanism (cleaning liquid application means) 14 is configured as shown in FIG.
In FIG. 3, the cleaning liquid application mechanism 14 is provided with a wet liquid holding unit 17 that holds a cleaning liquid (also referred to as a wet liquid) applied to the blade 10. An absorber 16 made of a porous member or the like is provided below the wet liquid holding unit 17. The absorber 16 absorbs the wet liquid held in the wet liquid holding part 17 and is in an impregnated state. On the side surface of the absorber 16, a scraper 15 having an opening is provided in the reciprocating range of the blade 10. That is, the blade 10 moves from the initial position shown in FIG. 1 in the forward movement direction (Y1) direction, wipes and passes through the ejection port forming surface 3a of the recording head 3, and then further moves in the Y1 direction. The blade 10 contacts the scraper 15. At the time of this contact, the scraper 15 presses the absorber by the blade 10 to exude the wet liquid impregnated in the absorber 16, and the exuded wet liquid is applied to the blade 10. As a result, the ink fixed to the blade 10 is dissolved, and further, the blade 10 moves in the Y1 direction and comes into sliding contact with the scraper 15, whereby the dissolved ink is scraped off from the blade 10. As a result, the blade 10 is cleaned. In the present invention, the member 15 that contacts the blade 10 by the movement of the blade 10 and presses the absorber 16 or is slidably contacted by the movement of the blade 10 to adhere to the blade 10 and scrape the accumulated ink is used as a scraper. It is called.

  In this example, a solvent containing glycerin is used as the wet liquid, but this wet liquid is not limited to glycerin. For example, trihydric alcohols such as water, a mixture of glycerin and water (50:50 mixture), 2-pyrrolidine, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and the like can be used as the wet liquid.

  When the cleaning liquid is applied to the blade 10 in this way, the ink discharge operation to the blade 10 from steps 2 to 8 can be omitted, and the recovery processing time can be shortened. However, if the ink discharge operation to the blade 10 and the application of the wet liquid by the scraper and the ink scraping operation are used in combination, wiping can be performed with the cleaned blade, and more reliably from the recording head. Ink can be removed.

  When this cleaning liquid application mechanism 14 is used, it is also effective to change the contact time of the blade 10 with the scraper 15 depending on the type of ink ejected from the recording head 3. That is, when the ink ejected from the recording head is changed from a low viscosity ink to a high viscosity ink, the contact time between the blade 10 and the scraper 15 is increased. This can be realized by reducing the moving speed of the blade 10 or by controlling the scraper to stop moving for a certain period of time when the blade 10 contacts the scraper 15. Conversely, when the ink ejected from the recording head 3 is changed from a high-viscosity ink to a low-viscosity ink, the moving speed of the blade 10 is reduced in order to reduce the contact time between the blade 10 and the scraper 15. To increase.

  Next, a comparison result between the ink ejection accuracy of Example 1 and Example 2 that executes the recovery process in the above embodiment and the ink ejection accuracy of Comparative Example 1 and Comparative Example 2 that executes the conventional recovery process will be described. Comparative Example 1 is a comparative example corresponding to Example 1, and Comparative Example 2 is a comparative example corresponding to Example 2.

(Comparative Example 1)
In this comparative example, the following recovery process was performed.
A: ejection onto the blade a1; types of ejected inks • cyan ink and light cyan ink a2; number of ejections • 50 shots (constant regardless of ink type)
B: Number of wiping operations • Once (constant regardless of ink type)
C: Wiping speed 120 mm / sec (constant regardless of ink type)
D: Cleaning liquid application mechanism-None

(Example 1)
In Example 1, the following recovery process was performed.
A) Discharge onto the blade a1; Kinds of ejected inks ・ Cyan ink and light cyan ink a2; Number of inks ejected onto the blade when the ink type has a lower viscosity than before replacement ・ 50 shots (per nozzle)
a3: Number of ejections of each ink to the blade when the ink type has a higher viscosity than before replacement 100 shots (per nozzle)
B) Number of wiping b1; Number of wiping when ink type has lower viscosity than before replacement • Number of wiping before recording; 1 time • Number of wiping after recording; 1 time b2; Ink type has higher viscosity than before replacement Number of wiping times in case of wiping before recording; 1 time. Number of wiping after recording; 2 times C) Wiping speed c1; Wiping speed when ink type has lower viscosity than before replacement. Wiping speed before recording: 120 mm / Sec
-Wiping speed after recording: 120 mm / sec
c2: Number of times of wiping when the ink type has a higher viscosity than before replacement. • Wiping speed before recording; 80 mm / sec.
-Wiping speed after recording: 80 mm / sec
D) Cleaning fluid application mechanism-None

(Comparative Example 2)
In Comparative Example 2, the following recovery process was performed.
-No discharge A: Discharge onto the blade-No discharge B: Number of wipings-Once (constant regardless of ink type)
C: Wiping speed: 120 mm / sec (constant regardless of ink type)
D: Cleaning liquid application mechanism d1: Cleaning liquid Mixed liquid of glycerin and water

(Example 2)
In Example 2, the following recovery process was executed.
A) Discharge onto the blade ・ No discharge B) Number of wiping b1; Number of wiping when the ink type has a lower viscosity than before replacement ・ Number of wiping before recording; 1 time ・ Number of wiping after recording: 1 time b2; Number of wiping when ink type has higher viscosity than before replacement ・ Number of wiping before recording; 1 time ・ Number of wiping after recording; 2 times C) Wiping speed c1; When ink type has lower viscosity than before replacement Wiping speed ・ Wiping speed before recording; 120mm / sec
-Wiping speed after recording: 80 mm / sec
c2: Number of times of wiping when the ink type has a higher viscosity than before replacement. • Wiping speed before recording; 80 mm / sec.
-Wiping speed after recording: 60 mm / sec
D) Cleaning liquid application mechanism d1; Cleaning liquid Mixed liquid of glycerin and water Here, the recording conditions of Examples 1 and 2 and the comparative example were set as follows.

  1000 solid images with 20% of each color printing amount are output on a recording medium of 1030 mm × 100 mm (pass number: 6, carriage speed: 33.3 inch / sec). Among them, a specific pattern is output every 200 sheets (number of passes: 1, carriage speed: 18.4 inches / sec).

  Based on the above pattern, the deviation (Y-direction deviation amount) in the media conveyance direction between the target landing position of the ejected ink and the actual landing position is measured, and the first and second embodiments are based on the standard deviation of the measured values. We compared the difference between the landing accuracy due to and the landing accuracy according to the comparative example. The Y-direction deviation amount σ (μm) was determined by the following equation.

The measurement environment was a temperature of 25 ° C. and a humidity of 40%.
The recording head was equipped with six colors of ink of cyan, magenta, yellow, light cyan, light magenta, and matte black. The type of ink to be replaced at the timing of 200 sheets, 600 sheets, and 1000 sheets was changed from mat-type black to photo-type black having a viscosity lower than that of mat-type black. In addition, the mat black was replaced at the timing of 400 sheets and 800 sheets. A pattern recorded with black ink was used to measure the amount of deflection in the Y direction.

  Table 1 shows the result of the amount of deviation in the Y direction (μm) with respect to the number of recorded sheets in the comparative example, Example 1 and Example 2 of the present invention.

  As shown in the above results, the amount of deviation in the Y direction of Comparative Example 1 and Comparative Example 2 started to become noticeable at the 200th sheet from the start of recording, and after recording 1000 sheets, in Comparative Example 1, it was about 38 μm. In Comparative Example 2, a twist of about 35 μm occurs. This amount of deviation is a level that is recognized by the user as a white streak in an actually recorded image, and is a factor that significantly reduces the image quality.

  On the other hand, the amount of deviation in the Y direction in Examples 1 and 2 of the present invention was stably 10 μm or less from the start of recording to the 1000th sheet. This amount of deviation is a level that is not recognized by the user in an actually recorded image, and does not cause a reduction in image quality. As a result, it has been clarified that in the first and second embodiments, the ink can be appropriately removed from the ejection port forming surface 3b.

  The present invention is applicable to all devices using recording media such as paper, cloth, leather, non-woven fabric, OHP paper, and metal. Specific examples of applicable equipment include office equipment such as printers, copiers, and facsimile machines, and industrial production equipment. In addition, the present invention is particularly effective for devices that perform high-speed recording on large recording media.

1 is a plan view showing an ink jet recording apparatus according to an embodiment of the present invention. FIG. 2 is a perspective view schematically showing a recording head and a blade in an embodiment of the present invention. It is a side view which shows typically the cleaning liquid application | coating mechanism in embodiment of this invention. It is a block diagram which shows schematic structure of the control system circuit which concerns on embodiment of this invention. It is a flowchart which shows an example of the discharge recovery process performed by embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Recording device main body 2 Carriage 3 Recording head 3a Ejection port 3b Ejection port formation surface 4 Guide shaft 5 Endless belt 6 Encoder film 7 Recovery processing device 7A, 7B Suction recovery mechanism 8 Preliminary ejection ink receiving box 9 Wiping mechanism 10 Wiping member (blade) )
DESCRIPTION OF SYMBOLS 14 Cleaning application mechanism 15 Scraper 16 Absorber 17 Wet liquid holding | maintenance part 100 Main control part 101 CPU
102 ROM
103 RAM
115 Ink information reading unit 116 Host computer

Claims (14)

An inkjet recording apparatus that performs recording using a recording head having an ejection port for ejecting ink and can change the type of ink ejected from the recording head,
Wiping recovery means for removing ink adhering to the periphery of the ejection opening of the recording head by a wiping recovery process using a wiping member;
An ink jet recording apparatus comprising: control means for controlling an operation related to wiping recovery processing of the wiping recovery means in accordance with the type of ink supplied to the recording head. The wiping recovery means includes wiping means for wiping off ink adhering to the periphery of the ejection port of the recording head by a wiping operation of the wiping member, and liquid applying means for applying a liquid to the wiping member,
The inkjet recording apparatus according to claim 1, wherein the control unit controls at least one of the wiping unit and the liquid applying unit according to a type of ink ejected from the recording head.   3. The ink jet recording apparatus according to claim 1, wherein the liquid applying unit discharges ink from the recording head to the wiping member in order to dissolve ink adhering to the wiping member.   The inkjet recording apparatus according to claim 3, wherein the liquid applying unit discharges ink different from the ink fixed to the wiping member from the recording head to the wiping member.   5. The ink jet recording apparatus according to claim 3, wherein the liquid applying unit discharges at least one type of ink among a plurality of types of ink supplied to each of the plurality of recording heads to the wiping member.   The ink jet recording apparatus according to claim 1, wherein the liquid applying unit includes a cleaning liquid applying unit that applies a cleaning liquid that dissolves ink fixed to the wiping member to the wiping member. .   The cleaning liquid application means is provided so as to be able to contact the wiping member, and applies the cleaning liquid to the wiping member when in contact with the wiping member, and is slidably contacted with the wiping member. The ink jet recording apparatus according to claim 6, wherein the ink attached to the ink is scraped off.   8. The control unit according to claim 1, further comprising a control unit configured to control an operation related to a wiping recovery process of the wiping recovery unit according to a viscosity of ink ejected from the recording head. Any one of the inkjet recording apparatuses.   9. The ink jet according to claim 2, wherein the control unit increases or decreases the number of wiping operations performed by the wiping recovery unit according to the viscosity of the ink ejected from the recording head. Recording device.   10. The ink jet recording apparatus according to claim 2, wherein the control unit increases or decreases the wiping operation speed according to the viscosity of the ink ejected from the recording head.   The control means reduces the wiping operation speed performed by the wiping member according to the level of the viscosity of the ink ejected from the recording head as compared with the case of ejecting the ink having a high viscosity. An ink jet recording apparatus according to claim 2.   12. The control unit according to claim 2, wherein the control unit increases or decreases the amount of liquid supplied from the liquid application unit to the wiping member according to the level of the viscosity of the ink ejected from the recording head. An ink jet recording apparatus according to claim 1.   13. The inkjet according to claim 2, wherein the control unit causes ink to be ejected from the recording head to the wiping member in accordance with a timing at which the wiping member wipes the recording head. Recording device. A recovery method in an ink jet recording apparatus that performs recording using a recording head having an ejection port for ejecting ink and can change the type of ink ejected from the recording head,
A wiping recovery step of removing ink adhering to the periphery of the ejection opening of the recording head by a wiping recovery process using a wiping member;
And a control step of controlling an operation related to the wiping recovery process of the wiping recovery means in accordance with the type of ink supplied to the recording head.

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