JP2011101969A - Inkjet recording apparatus and recovery method of recording head in the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording apparatus which suppresses bad effects of mist while shortening recovery operation time. <P>SOLUTION: Ink receiving parts 7A1 and 7B1 are provided in the recording apparatus body 1, and preliminary discharge is performed by discharging ink from the nozzle of a recording head 3 to the ink receiving parts. When the preliminary discharge is performed, closed state is brought about by covering the perimeter of the nozzle of a recording head 3 with the ink receiving parts 7A1 and 7B1 if a recording medium exists in a recording region 8, and open state is brought about by opening the perimeter of the nozzle if a recording medium does not exist in the recording region 8. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus that performs recording using a recording head capable of ejecting ink, and a recovery method for recovering the ejection performance of the recording head to a good state.

Many ink jet recording apparatuses perform so-called preliminary ejection in which ink is periodically ejected from nozzles and the ink in the nozzles is replaced with ink suitable for ejection. Usually, preliminary ejection is performed on a preliminary ejection port provided outside the conveyance path of the recording medium, or a suction cap that serves as both the suction means and the capping means of the recording head. In the preliminary discharge to the suction cap, the ink preliminarily discharged into the cap is sucked at an appropriate timing. However, when preliminary ejection is performed, minute ink droplets are generated separately from the main ink droplets (main droplets) that reach the surface of the ink receiving portion such as the cap and the preliminary ejection port, and these droplets float in the air and become mist. It may become. It is also known that ink droplets that have reached the ink receiving part become mist by bouncing back at the ink receiving part.

  When the carriage is scanned in a state where such ink mist is generated, the mist moves in the recording apparatus due to the generation of an air flow accompanying the movement of the carriage and adheres to the recording medium, or the ejection surface of the recording head. Or may adhere to the platen and soil the recording medium. Further, when mist adheres to and solidifies on the movable part in the recording apparatus, the moving resistance of the movable part such as the carriage increases, which may hinder the recording operation.

  In order to deal with such a problem, Patent Document 1 discloses a technique for reducing floating mist in the recording apparatus by performing preliminary discharge in a state where the discharge port is covered with a cap when the number of discharges during preliminary discharge is large. Disclosed.

JP 2007-125900 A

  As described above, according to the technique disclosed in Patent Document 1, it is possible to suppress the occurrence of mist by performing preliminary discharge while the discharge port is covered with a cap. However, since it takes time to move the cap toward the recording head in order to cover the ejection port with the cap, the time required to recover the ejection state increases. In Patent Document 1, when preliminary ejection with a large number of ejections is performed, the ejection port is always covered with a cap, which causes a problem that throughput decreases.

  The present invention has been made paying attention to the above problems, and an object of the present invention is to provide a recovery method in which the recovery operation time is shortened and the harmful effects of mist are suppressed.

  In order to achieve the above object, the present invention has the following configuration.

  That is, according to the first aspect of the present invention, an image is recorded by ejecting ink from a nozzle provided in a recording head to a recording medium conveyed to a recording area defined in the recording apparatus main body. An ink jet recording apparatus capable of performing preliminary ejection for ejecting ink from the nozzles to an ink receiving part provided in a recording apparatus main body, wherein the ink receiving part covers the periphery of the nozzles and the ink It is possible to set the receiving portion to any one of an open state in which the receiving portion is separated from the periphery of the nozzle, and when the preliminary ejection is performed, the closed state is set when the recording medium exists in the recording region. And a control means for controlling the recording medium to be opened when the recording medium does not exist in the recording area.

According to a second aspect of the present invention, an image is recorded by ejecting ink from a nozzle provided in a recording head to a recording medium conveyed to a recording area defined in the recording apparatus main body. A method for recovering a recording head in an ink jet recording apparatus capable of executing preliminary discharge for discharging ink from the nozzle to an ink receiving portion provided in a main body,
When the recording medium is present in the recording area when the preliminary ejection is performed, the ink receiving portion forms the closed state covering the periphery of the nozzle, and the recording medium is not present in the recording area. Is characterized in that an open state in which the ink receiving portion is separated from the periphery of the nozzle is formed.

  In the present invention, when a recording medium is present in the recording area, preliminary ejection is performed in a closed state in which the ejection port of the recording head is covered by the ink receiving portion. It is possible to greatly reduce contamination. Further, when there is no recording medium in the recording area, the preliminary ejection is performed in the open state in which the ink receiving portion is separated from the recording head, so that it is possible to shorten the time required for the preliminary ejection. Furthermore, since there is no recording medium on the recording area at this time, it is possible to avoid the generated mist from adhering to the recording medium.

1 is a plan view schematically showing an internal configuration of an ink jet recording apparatus applicable to an embodiment of the present invention. 1 is a perspective view schematically showing a recording head applied to an embodiment of the present invention. 1 is a block diagram illustrating a schematic configuration of a control system of an ink jet recording apparatus according to an embodiment of the present invention. FIG. 5 is a diagram illustrating the number of discharges and the cap open / close state of each of a plurality of types of preliminary discharges that are performed in the ink jet recording apparatus according to the first embodiment of the present invention. It is a flowchart which shows the attraction | suction operation | movement sequence in the 1st Embodiment of this invention. It is a flowchart which shows the operation system determination sequence of the preliminary | backup suction discharge operation | movement in 1st Embodiment. It is a flowchart which shows the operation system determination sequence of the preliminary | backup suction discharge operation | movement in 2nd Embodiment.

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
FIG. 1 is a plan view showing an ink jet recording apparatus according to the first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a recording apparatus main body provided with various mechanism units including a recording medium transport system unit (not shown). 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) which is the conveying direction of the recording medium. The recording operation is performed while moving in the X 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). As the recording medium, cut paper, roll paper, or the like can be used.

  In FIG. 1, reference numeral 2 denotes a carriage 2 on which the recording head 3 is detachably mounted. 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 movably supported by 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). A recording area 8 through which the recording medium passes is defined in an area facing the recording head 3 mounted on the carriage 2. That is, the recording area 8 is a range where recording can be performed by the recording head. Accordingly, the ink ejected from the recording head 3 is landed on the recording medium transported from the recording medium preparation position (not shown) to the recording area 8 by the transport system unit, and an image is recorded. The recording apparatus main body 1 is provided with a recording medium detection sensor (not shown) that detects the presence or absence of the recording medium in the recording area 8.

  FIG. 2 is a schematic diagram of the recording head 3 mounted on the carriage 2 according to the embodiment of the present invention. In the recording head 3, as shown in the schematic diagram of FIG. 2, a plurality of discharge ports 3a formed on the discharge port forming surface 3b and a plurality of liquid passages formed corresponding to the individual discharge ports 3a (FIG. And a common liquid chamber (not shown) for supplying ink to the plurality of liquid paths. In the following description, the discharge port 3a and the liquid path are collectively referred to as a nozzle.

  Each recording head 3 of this embodiment is provided with six nozzle groups Nc, Nm, Ny, NLc, NLm, and Nb corresponding to each of the six colors of cyan, magenta, yellow, light cyan, light magenta, and black. It has been. Each nozzle group has a configuration in which 1280 ejection ports that eject ink of the same color are arranged at a density of 1200 dpi (dots / inch). The recording head 3 reciprocates along the X direction (main scanning direction) in FIG. 2 together with the carriage 2 while being mounted on the carriage 2. In the recording head 3 shown in FIG. 2, the discharge ports 3a are arranged in a staggered manner in order to increase the recording operation speed and definition. In each liquid path of the recording head 3, an energy generating element that generates ejection energy for ejecting ink from the ejection port 3a is disposed. 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.

  Ink is supplied to each ejection port group of the recording head 3 mounted on the carriage 2 from an ink tank containing ink containing a coloring material. In the present embodiment, the recording apparatus main body 3 is provided with an ink tank (not shown) that stores ink containing cyan, magenta, yellow, light cyan, light magenta, and black color materials. Each ink tank provided in the recording apparatus main body 3 is connected to a nozzle group of the corresponding recording head 3 via an ink supply port via a tube (not shown), and each ink tank is connected via this tube. Ink is supplied to each corresponding 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 outside the recording area 8 of the recording apparatus main body 1 and facing the recording head 3. The recovery processing device 7 includes suction recovery mechanisms 7A and 7B, a lifting mechanism (not shown) that lifts and lowers them, and a wiping recovery device 9.

  The suction recovery mechanisms (discharge means) 7A and 7B perform a suction recovery process which is a form of the recovery process. This suction recovery process is suitable for ejecting ink in nozzles by forcibly sucking ink from a plurality of nozzles formed on the recording head to discharge bubbles and thickened ink generated in the nozzles. This is the process of replacing the ink in a fresh state. Specifically, the suction recovery mechanisms 7A and 7B cover the ejection port forming surface 3b (see FIG. 2) with caps 7A1 and 7B1 as ink receiving portions, and a pump (negative pressure) (not shown) communicating with the cap. Generating means) generates a negative pressure in the caps 7A1 and 7B1. By this negative pressure, the ink is forcibly sucked into the caps 7A1 and 7B1 from the discharge port 3a and discharged to the outside through the pump. Further, the ink jet recording apparatus according to the present embodiment performs preliminary ejection, which is another form of the recovery process, on the caps 7A1 and 7B1 of the suction recovery mechanisms 7A and 7B. In this preliminary ejection, ink that does not contribute to image recording is ejected in order to replace the ink in the nozzle with ink in a state suitable for ejection. The suction recovery mechanism 7A performs suction recovery of the three nozzle groups Nc, Nm, and Ny shown in FIG. 2, and the suction recovery mechanism 7B performs suction recovery of the nozzle groups NLc, NLm, and Nb.

  Further, the wiping recovery device (wiping recovery means) 9 is provided so as to be opposed to 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 ejection port forming surface 3 b of the recording head using a wiping member (blade) 10, and an operating portion of the blade 10.

  FIG. 3 is a block diagram showing a schematic 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. 6, reference numeral 100 denotes a main control unit. The main control unit 100 includes a CPU 101 that executes processing as arithmetic means, control means, and discrimination means, and a ROM 102 that stores a control program to be executed by the CPU 101. The main control unit 100 further includes a buffer for storing binary print data representing ink ejection / non-ejection, a RAM 103 used as a work area for processing by the CPU 101, an input / output port 104, and the like.

  Connected to the input / output port 104 are drive circuits 105, 106, 107, 108 such as a transport motor (LF motor) 113, a carriage motor (CR motor) 114, a recording head 3, and a recovery processing device 7 in the transport unit. Has been. Further, various sensors are connected to the input / output port 104. Examples of the sensors include a head temperature sensor (head temperature detecting means) 112 that detects the temperature of the recording head, an encoder sensor 111 that is fixed to the carriage 2, and a temperature and humidity sensor that detects the temperature and humidity of the recording apparatus main body 1. 109 and the like.

  The input / output port 104 is connected to counters 116, 117, 118, and 119 that count the amount of ink ejected or discharged from the nozzles of the recording head as the number of ejected ink droplets. Here, the counter 116 is a recovery processing counter that counts the amount of ink as the number of ejected ink droplets when ink is forcibly discharged from the recording head 3 by the recovery processing device 7. The counter 117 is a preliminary ejection counter that counts preliminary ejection performed during recording before the start of recording or at the end of recording. The counter 118 is a borderless ink counter that counts ink recorded outside the recording medium area when borderless recording is performed. The counter 119 is a discharge dot counter that counts ink discharged during printing. The above configuration is mounted in the recording apparatus main body 1. The main control unit 100 is connected to a host computer 115 provided outside the recording apparatus main body 1 via an interface circuit 110.

  Next, an outline of a recording operation executed by the ink jet recording apparatus having the above configuration will be described. When recording data is received from the host computer 115 via the interface, the recording data is expanded in the 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 in accordance with binary recording data indicating ink ejection / non-ejection, and an image for one band is recorded on the recording medium. Thereafter, the recording unit conveys the recording medium by one band in the Y direction (sub-scanning direction) orthogonal to the carriage 2. 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 111 as the carriage 2 moves by the main control unit 100. That is, the encoder sensor 111 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. Movement of the carriage 2 to the home position and other positions is also performed based on a signal from the encoder sensor 111.

  Next, the preliminary discharge executed by the present embodiment will be described. There are the following two methods for preliminary ejection. One of them is a method of performing preliminary discharge toward the caps 7A1 and 7B1 in a state where the discharge port forming surface 3b of the recording head 3 and the caps 7A1 and 7B1 are separated from each other. Hereinafter, this type of preliminary discharge is referred to as cap-open preliminary discharge. As another method, the discharge port forming surface 3b of the recording head 3 and the caps 7A1 and 7B1 are brought into close contact with each other so as to cover the periphery of the discharge port 3a of the recording head 3 and to block the discharge port 3a from the outside air. There is a method of performing preliminary discharge. Hereinafter, this type of preliminary discharge is referred to as cap-closed preliminary discharge. In the following description, separating the caps 7A1 and 7B1 from the ejection port forming surface 3b of the recording head 3 is referred to as opening the cap, and the caps 7A1 and 7B1 are brought into close contact with the ejection port forming surface 3b of the recording head 3. This is called closing the cap. The operation of switching from the opened state to the closed state is also referred to as capping.

  FIG. 4 shows the number of discharges and the preliminary discharge method in various preliminary discharges performed by the ink jet recording apparatus according to the present embodiment. The types of preliminary ejection performed in the present embodiment include pre-recording preliminary ejection, pre-recording preliminary ejection, post-wiping preliminary ejection, and pre-suction preliminary ejection. Here, the pre-recording preliminary discharge is performed immediately before the cap that has been closed in order to eliminate blurring at the initial stage of recording caused by the evaporation of ink from the nozzles is opened to start the recording operation. Pre-discharge. In the pre-recording preliminary ejection, the number of ejections varies depending on the elapsed time from the previous capping to the start of pre-recording preliminary ejection. In the present embodiment, the number of ejections from 100 to 10,000 is selected per nozzle according to the elapsed time from the previous capping to the start of pre-recording preliminary ejection. In this preliminary ejection before recording, if the number of ejections selected is about 100 per nozzle, even if the caps 7A1 and 7B1 are opened, a large amount of mist does not occur, and the recording medium and the recording apparatus main body 1 The influence of mist on moving parts is small. However, since this pre-recording pre-ejection is performed every time a recording signal is input, the actual pre-recording pre-ejection is executed many times, and the influence of mist on the printing apparatus main body and the printing medium becomes large. For this reason, in the preliminary discharge before recording, the preliminary discharge (cap closed preliminary discharge) is executed with the caps 7A1 and 7B1 closed.

  Pre-discharge during recording is specified during recording or during recording interruption in order to eliminate blurring or density increase caused by evaporation of ink moisture from the nozzle during recording or during recording interruption. This is a preliminary discharge mode performed at the time interval. In the present embodiment, during recording, 16 preliminary discharges (cap open preliminary discharge) are performed toward the caps 7A1 and 7B1 spaced from the discharge port forming surface 3a of the recording head 3 before scanning of the recording head 3. Executed. Further, while recording is interrupted due to waiting for transfer of recording data from the host computer 115, the preliminary ejection is executed with the caps 7A1 and 7B1 opened at intervals of once every 3 seconds. The preliminary ejection during recording has a small influence on the recording medium and the recording apparatus main body 1 because the amount of mist generated per time is small. However, since preliminary ejection is performed during recording each time scanning is performed, the influence of mist on the recording apparatus main body 1 is not zero. Accordingly, it is preferable to perform cap closed preliminary discharge in consideration of the influence of mist. However, since the influence on the throughput is very large, the cap opening preliminary discharge is executed.

  The preliminary ejection after wiping is preliminary ejection performed after wiping the ink of each color adhering to the ejection port forming surface 3b with the wiping member 10. When the ink adhering to the discharge port forming surface 3b is wiped off by the wiping member, different color inks may be pushed into the nozzles and color mixing may occur. When the mixed color ink is discharged as it is onto the recording medium, the image quality deteriorates, so it is necessary to discharge the mixed color ink in the nozzle prior to the recording operation. For this reason, preliminary discharge after wiping is executed. In the present embodiment, 1000 cap closed preliminary discharges are executed after the wiping operation. Wiping is executed at the end of recording or after each operation. Since the preliminary discharge after wiping is executed for each wiping, the number of times that the preliminary discharge is executed during the lifetime of the printing apparatus main body is large. Therefore, the cap-closed preliminary discharge is executed in order to suppress the amount of mist generated.

  The preliminary discharge after suction is a preliminary discharge performed to prevent the mixed color ink generated on the cap by the suction recovery operation from flowing back into the nozzle to be discharged onto the recording medium. is there. In the present embodiment, the suction recovery operation is automatically performed every predetermined time or every predetermined number of ejections. It is also possible for the user to arbitrarily execute at a predetermined timing. This pre-suction preliminary discharge is executed at the end of the recording or after the scan is stopped during the recording operation.

  FIG. 5 shows a suction operation sequence in the present embodiment. In the present embodiment, when a suction operation is performed (step 1), wiping (step 3) is performed in order to reliably recreate the meniscus of the nozzle that has been broken by the suction operation, and then preliminary discharge after suction is performed. Implement (Step 5). Here, the number of preliminary ejections after suction differs depending on the ink color, and is 10,000 to 100,000. Since the caps 7A1 and 7B1 are in a closed state during the suction operation, before performing the wiping operation, the caps 7A1 and 7B1 are opened and separated from the discharge port forming surface 3b as shown in Step 2 of FIG. And avoid interference with the wiping member. In addition, after performing wiping in Step 3, a waiting time of one second is set, and after the ink wiped off by wiping is sucked into the nozzle, preliminary ejection is performed after suction. According to this, it becomes possible to discharge the mixed color ink in the nozzle more reliably.

  By the way, according to the study of the inventors of the present application, when the recording paper as a recording medium exists in the recording area 8 and the preliminary ejection after suction is performed by the cap-open preliminary ejection, the recording paper is separated from the recording paper by 30 cm. The mist adhered to the recording paper to the extent that it can be observed with the naked eye from the position. Further, when the preliminary ejection after suction was performed by the cap-open preliminary ejection in the state where the recording paper did not exist in the recording area, mist adhesion to the recording paper was not recognized in the subsequent recording operation or the like. It should be noted that the number of executions of preliminary ejection after suction during the life of the recording apparatus main body is overwhelmingly small compared to other preliminary ejections. For this reason, the influence of mist on the recording apparatus main body when the preliminary discharge after suction is executed by the cap-open preliminary discharge is small. However, when a recording sheet exists in the recording area as described above, there arises a problem that mist adheres to the recording sheet.

  Therefore, based on the above examination results, in the present embodiment, when a recording medium exists in the recording area 8 at the time of performing the suction operation, the preliminary discharge after suction is closed to prevent the mist from adhering to the recording medium. It is executed with preliminary discharge. When there is no recording medium in the recording area 8, the preliminary discharge after suction is executed by the cap-open preliminary discharge in order to shorten the recovery time. In this way, by performing cap open preliminary discharge when there is no recording medium in the recording area 8, it is possible to reduce the recovery time by 5 seconds compared to when cap closed preliminary discharge is performed. In addition, as shown in FIG. 4, the preliminary ejection after suction has a large number of ejections once, and the ink preliminarily ejected to the caps 7A1 and 7B1 exceeds the cap capacity. For this reason, in the present embodiment, when the cap open preliminary discharge is performed, the pump is operated to perform the preliminary discharge while discharging the ink in the cap to the outside, thereby preventing the ink from overflowing from the cap. . Further, when the cap closed preliminary discharge is executed, the pump is operated with the atmospheric communication valve provided in the flow path connecting the pump and the cap open, and the preliminary discharge is performed while discharging the ink in the cap to the outside.

FIG. 6 shows a preliminary ejection method determination sequence when performing post-suction preliminary ejection in the present embodiment.
When the suction operation execution command is generated, it is determined in step 10 whether or not a recording medium exists in the recording area 8. This determination is performed by the CPU 101 based on a detection signal (detection result) of a recording medium detection sensor that detects whether or not a recording medium exists in the recording area. If it is determined that there is no recording medium in the recording area, cap-closed preliminary discharge is selected as preliminary discharge after suction (step 11). If there is a recording medium, cap open preliminary discharge is selected as preliminary discharge after suction (step 12).

(Second Embodiment)
Next, a second embodiment of the present invention will be described.
In the first embodiment, the recording medium detection sensor detects whether or not the recording medium exists in the recording area 8, whereas the ink jet recording apparatus in the second embodiment. Is not provided with a recording medium detection sensor. In the first embodiment, a cut sheet having a predetermined size is used as a recording medium in advance. On the other hand, in the second embodiment, not only cut paper but also roll paper can be used as the recording medium. Further, when the recording paper is roll paper, the recording medium is cut after the recording operation is completed. It is possible to select a mode that does not disconnect. The second embodiment is different from the first embodiment in these points, and further executes a preliminary discharge method determination sequence shown in FIG. 7 described below before executing the preliminary discharge after suction. This is different from the first embodiment. However, also in the second embodiment, the configuration shown in FIGS. 1 to 3 is provided and the various preliminary ejections shown in FIG. 5 are performed, and redundant description thereof will be omitted.

Next, a preliminary ejection method determination sequence that is performed when performing preliminary ejection after suction will be described based on the flowchart of FIG.
When the suction operation execution command is generated, it is first determined based on the recording data whether or not the recording operation is being performed, that is, whether or not recording of an image to be formed is not completed (step 21). If it is determined that the recording operation is being performed, the recording medium is present in the recording area 8, and therefore the cap-closed preliminary discharge is selected as the preliminary discharge after suction to be executed. If it is determined in step 21 that the recording operation is not being performed, in step 22, whether roll paper is selected as the recording medium to be used, that is, whether roll paper is selected or cut paper is selected. Judgment is made. If it is determined that roll paper has not been selected and cut paper has been selected, there is no recording medium in the recording area 8, and therefore, pre-suction pre-ejection to be performed. Cap opening preliminary discharge is selected (step 27). In the recording operation using the cut sheet, the recording medium is not present in the recording area 8 because the recording medium is discharged from the recording area 8 to the paper discharge unit when the recording operation on the recording medium is completed.

  On the other hand, if it is determined in step 22 that roll paper is selected, it is determined whether or not a cutting mode for cutting the roll paper is set after the recording operation is completed (step 23). In this cutting mode, after the recording operation on the recording medium is completed, the recording medium is cut by a known cutting means at a position upstream of the recording area 8 in the conveyance direction of the recording medium. Accordingly, if it is determined in step 23 that the cutting mode is set, the recording medium 8 does not exist in the recording area 8, so that the cap-open preliminary discharge is selected as the preliminary discharge after suction to be executed. Is done. If it is determined in step 23 that the mode that does not cut is set, it is determined that a recording medium is present in the recording area 8, so that the cap-closed preliminary discharge is performed as the preliminary discharge after suction to be executed. Discharge is selected (step 26).

  As described above, in the second embodiment, it is possible to determine whether or not a recording medium exists in the recording area without using the recording medium detection sensor. When the recording medium is present in the recording area 8, the cap-closed preliminary discharge is executed as the preliminary discharge after suction to suppress the amount of mist generated, so that the deterioration in image quality due to the mist adhering to the recording medium is suppressed. be able to. Further, when the recording medium is not present in the recording area 8, cap opening preliminary discharge is executed as preliminary discharge after suction. For this reason, it is possible to omit the movement operation for bringing the caps 7A1 and 7B1 into contact with the ejection port forming surface 3b of the recording head 3, and the time required for preliminary ejection can be shortened, and a good throughput can be achieved. can get.

  In each of the above-described embodiments, the cap opening is performed according to whether or not a recording medium is present in the recording area 8 in the preliminary discharge after suction, in which the discharge amount per time is the largest among the various possible preliminary discharges. The case where the preliminary discharge or the cap closed preliminary discharge is selected and executed has been described as an example. However, the pre-discharge method other than the preliminary discharge after suction is selected as the preliminary discharge method in which the cap-open preliminary discharge is performed when the recording medium is present in the recording area 8 and the cap-closed preliminary discharge is performed when the recording medium is not present in the recording area 8. It is also possible to carry out the preliminary discharge. That is, the type of preliminary discharge to be selected as described above may be determined in consideration of the amount of mist generated during preliminary discharge, the degree of influence of mist on the recording medium, and the like. It is not limited to the discharge method.

  Further, in each of the above embodiments, the recovery means for maintaining the ejection performance of the recording head is exemplified as a discharging means that forcibly discharges ink from the nozzles of the recording head, which includes a suction recovery mechanism. However, as a discharge means for forcibly discharging ink from the nozzle, in addition to the suction recovery mechanism, pressure (positive pressure) is applied to the inside of the recording head to forcibly push out the ink from the nozzle of the recording head. There is also a recovery device. The present invention can also be applied to an ink jet recording apparatus using this pressure recovery apparatus.

DESCRIPTION OF SYMBOLS 1 Recording device main body 2 Carriage 3 Recording head 3a Ejection port 3b Ejection port formation surface 7 Recovery processing device 7A, 7B Suction recovery mechanism 7A1, 7B1 Cap 8 Recording area 9 Wiping recovery device 10 Wiping member 100 Main control part

Claims (7)

An image is recorded by ejecting ink from nozzles provided in the recording head onto a recording medium conveyed to a recording area defined in the recording apparatus main body, and in an ink receiving portion provided in the recording apparatus main body. An ink jet recording apparatus capable of performing preliminary ejection for ejecting ink from the nozzles,
The ink receiving portion can be set to either a closed state covering the periphery of the nozzle or an open state separating the ink receiving portion from the periphery of the nozzle;
Control means for performing the preliminary ejection so as to control the closed state when the recording medium exists in the recording area and the open state when the recording medium does not exist in the recording area. ,
An ink jet recording apparatus comprising:   2. The ink jet recording apparatus according to claim 1, wherein the control unit performs the control when performing preliminary ejection in which the number of inks ejected by one preliminary ejection exceeds a predetermined number. 3. A discharge means for forcibly discharging the ink from the recording head;
3. The ink jet recording apparatus according to claim 1, wherein the control unit performs the control at the time of preliminary discharge that is executed after the ink is discharged by the discharge unit. The discharging means comprises a suction recovery mechanism having the ink receiving portion and a negative pressure generating means connected to the ink receiving portion,
4. The ink jet recording apparatus according to claim 3, wherein the suction recovery mechanism sucks ink from the nozzles by generating a negative pressure in the ink receiving portion in the closed state.   5. The control unit according to claim 1, wherein the control unit performs the control based on a result detected by a detection unit that detects whether or not the recording medium is present in a recording area. The ink jet recording apparatus described.   When the preliminary ejection is performed during the recording operation on the recording medium, the control unit determines that the recording medium exists in the recording area, and the ink receiving portion covers the periphery of the nozzle and is closed. When the recording operation on the recording medium is completed, it is determined that there is no recording medium in the recording area, and the ink receiving portion is formed in an open state. The inkjet recording apparatus according to claim 1, wherein the control is performed on the inkjet recording apparatus. An image is recorded by ejecting ink from a nozzle provided in the recording head to a recording medium conveyed to a recording area defined in the recording apparatus main body, and for an ink receiving portion provided in the apparatus main body. A recovery method of a recording head in an ink jet recording apparatus capable of performing preliminary discharge for discharging ink from the nozzles,
When the recording medium is present in the recording area when the preliminary ejection is performed, the ink receiving portion forms the closed state covering the periphery of the nozzle, and the recording medium is not present in the recording area. And forming an open state in which the ink receiving portion is spaced apart from the periphery of the nozzle.

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