JP2009113377A - Ink-jet recording device and its restoring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress drop of the picture quality of a recorded image by shortening the time required to make preliminary discharge even in case recording is conducted with a minor-dot ink discharged. <P>SOLUTION: Judgement is made for which preliminary discharge is to be conducted, the first preliminary discharge performed in a position set off from a recording medium about the scanning direction of a recording head or the second preliminary discharge performed on the recording medium so that the ink discharged from a discharge hole does not reach the recording medium. According to the result of the judgement, the recording head is controlled so that the preliminary discharge is performed by either the first or the second preliminary discharge at each predetermined timing. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inkjet recording apparatus such as a printer, a copying machine, and a facsimile apparatus that records an image on a recording medium such as paper or a plastic sheet, and a recovery method thereof.

  At present, inkjet recording apparatuses form a high-quality recorded image by ejecting small dot ink, and have become widespread in fields such as copying and faxing by shortening the recording time.

  In an ink jet recording apparatus, if ink is not ejected for a predetermined time or more, the ink is fixed in the vicinity of the ejection port due to evaporation of moisture or the like in the ink, and ink ejection becomes unstable. For this reason, for the purpose of stabilizing the ejection of ink that contributes to recording, preliminary ejection, which is ejection of ink that does not contribute to recording, has been performed at regular time intervals. Since ink ejected by this preliminary ejection does not contribute to recording, a method of performing preliminary ejection by moving a carriage on which a recording head is mounted to a position outside the recording area is well known.

Further, in a large-sized ink jet recording apparatus such as a plotter, since it takes time to move the carriage to a position outside the recording area, the recording time may not be shortened if the carriage is moved each time preliminary ejection is performed. Therefore, a control method (for example, Patent Document 1) that detects image data on the recording medium and performs preliminary ejection based on the result, or performs preliminary ejection of ink on the recording medium at a constant timing regardless of the recording image. A control method (for example, Patent Document 2) is known.
JP 2006-1051 A JP 2006-76247 A

  In recent years, the ink-jet recording apparatus has been further reduced in size in order to form a higher-quality recorded image. Along with this, the recording medium must be filled with ink with small dots, and the time required for recording becomes long. The time required for this recording includes not only the time for actually ejecting ink to the recording medium for recording, but also the time for preliminary ejection for stabilizing the ink ejection during recording. As the dot size decreases, the time interval for preliminary ejection performed to stabilize ink ejection during recording becomes shorter. This increases the time required for recording.

  Furthermore, generally, while recording data is not input to the ink jet recording apparatus, the ejection port is capped to prevent moisture evaporation from the ejection port. Further time required for preliminary discharge is required. For this reason, the time required for recording is further increased.

  On the other hand, if preliminary ejection is performed on the recording medium in order to shorten the time required for preliminary ejection, recording that is originally unnecessary is performed on the recording medium, so that the quality of the recorded image may be reduced.

  Accordingly, the present invention is to solve the above-described problems, and is an inkjet recording method that reduces the time required for preliminary ejection even when performing recording by ejecting small dot ink, and suppresses degradation in the image quality of the recorded image. It is an object of the present invention to provide an apparatus and a recovery method thereof.

The present invention for solving the above problems is an ink jet recording apparatus that records an image on a recording medium by scanning a recording head that discharges ink from an ejection port in a direction orthogonal to the conveyance direction of the recording medium,
A first preliminary ejection that is performed at a position deviating from the recording medium with respect to the scanning direction at the same ejection speed as the ejection speed of the ink ejected when recording is performed, and the ink ejected from the ejection port is the recording Whether the preliminary ejection to be performed is performed as a second preliminary ejection to be performed on the recording medium at an ejection speed slower than the ejection speed of the ink ejected when performing the recording so as not to reach the medium. Determination means for determining according to at least one of the position of the head and the scanning direction;
Control means for controlling the recording head to perform preliminary ejection by either the first preliminary ejection or the second preliminary ejection at each predetermined timing according to a judgment result of the judgment means;
It is characterized by having.

Another embodiment of the present invention for solving the above-described problem is a recovery of an ink jet recording apparatus that records an image on a recording medium by scanning a recording head that ejects ink from an ejection port in a direction orthogonal to the conveyance direction of the recording medium. A method,
A first preliminary ejection that is performed at a position deviating from the recording medium with respect to the scanning direction at the same ejection speed as the ejection speed of the ink ejected when recording is performed, and the ink ejected from the ejection port is the recording Whether the preliminary ejection to be performed is performed as a second preliminary ejection to be performed on the recording medium at an ejection speed slower than the ejection speed of the ink ejected when performing the recording so as not to reach the medium. A determination step of determining according to at least one of the position of the head and the scanning direction;
A control step of controlling the recording head to perform preliminary ejection by either the first preliminary ejection or the second preliminary ejection at each predetermined timing according to the judgment result in the judgment step;
It is characterized by having.

  According to the present invention, even when recording is performed by ejecting small dot ink, it is possible to reduce the time required for preliminary ejection and to suppress the degradation of the image quality of the recorded image.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  In this specification, “recording” (hereinafter also referred to as “printing”) is not only for forming significant information such as characters and figures, but also for images on a wide range of recording media, regardless of significance. A case where a pattern, a pattern, or the like is formed or a medium is processed is also expressed. It does not matter whether it has been made obvious so that humans can perceive it visually.

  “Recording medium” refers not only to paper used in general recording apparatuses but also widely to cloth, plastic film, metal plate, glass, ceramics, wood, leather, and the like that can accept ink. Shall.

  The term “ink” should be broadly interpreted in the same way as the definition of “recording”. When applied to a recording medium, the “ink” forms an image, a pattern, a pattern, or the like, or processes the recording medium. It represents a liquid that can be subjected to the treatment. Examples of the ink treatment include solidification or insolubilization of the colorant in the ink applied to the recording medium.

Example 1
FIG. 1 is an external perspective view showing a state where a cover of an ink jet recording apparatus that can suitably carry out the present invention is removed. The carriage 1 is supported by a guide shaft 2 and a guide rail (not shown) so as to reciprocate against the LF roller 5 and the platen held in the chassis. The recording head 7 is mounted on the carriage 1 and reciprocates along the guide shaft 2 by a carriage motor 8 transmitted via a belt 9.

  At the time of recording, the carriage 1 moves from a stop state at a constant speed after being accelerated. In this state, the recording head 7 is driven according to the recording data sent to the ink jet recording apparatus, and ink is ejected onto the recording medium conveyed by the LF roller 5. After one scan of the recording head 7 is completed, the carriage 1 is decelerated and stopped, and the recording medium is transported in the transport direction perpendicular to the scanning direction of the recording head 7 by the amount recorded by one scanning. The Recording on one recording medium is performed by alternately repeating scanning of the recording head 7 and conveyance of the recording medium.

  A pump base 30 is provided at the home position of the carriage 1 for maintenance of the recording head 7. When recording is not performed for a long time such as when the power is turned off, the carriage 1 returns to the position of the pump base 30 and covers the discharge surface with a cap. By doing so, the evaporation of the moisture of the ink is prevented, and the ejection performance of the recording head 7 is maintained by performing recovery operations such as wiping and suction as necessary.

  FIG. 2 is a partial perspective view showing a schematic configuration of a carriage drive mechanism.

  The guide shaft 2 is fixed to the chassis and serves as a guide when the carriage 1 reciprocates. The belt 9 wound on the left and right sides of the ink jet recording apparatus is connected to a carriage motor 8 fixed to the chassis and fixed to the carriage 1. The rotation of the carriage motor 8 is converted into a reciprocating motion to move the carriage 1. Have a role to let you. The encoder scale 40 is marked with a constant pitch and is held on the chassis with a predetermined tension.

  For example, 300 LPI (Line Per Inch), that is, marks provided at intervals of 25.4 mm / 300 = 84.6 μm are detected by the encoder sensor 45 fixed to the carriage 1 on the encoder scale 40. By doing so, the position of the carriage 1 can be obtained accurately. As an encoder system, an optical system or a magnetic system is used.

  The position information of the carriage 1 is compared with set values corresponding to the start position and the end position of recording that determine the recording position of the ejection port array provided in the recording head 7. Ink ejection is started from the ejection port array at a point where the recording start position coincides with the position information of the carriage 1, and ink ejection is terminated at a point where the recording end position coincides with the position information. . Further, when the carriage 1 is scanned, the moving speed of the carriage 1 can be calculated from the time interval of continuous detection of marks provided on the linear encoder scale 40.

  FIG. 3 is a block diagram showing a control configuration of an ink jet recording apparatus that can suitably carry out the present invention.

  In the figure, reference numeral 301 denotes a CPU (central processing unit) that controls the entire inkjet recording apparatus. Various instruction signals are input via the ASIC 305 from various switches (SW) such as the carriage encoder sensor 312 and the paper detection sensor 313 and the power SW 309 and the cover open SW 311 provided on the operation panel according to the control program in the ROM 303. Further, the recording command transmitted from the host device is input to the I / F controller 320 via the interface (I / F) 321. Based on the instruction signal and the recording command, rotation control of the carriage motor 8, the paper feed motor 318, and the paper feed motor 319 is performed via the motor drivers 314 to 316. Further, based on the instruction signal and the recording command, recording data is transferred to the recording head 7 via the ASIC 305, and recording control corresponding to the recording command is performed.

  Reference numeral 302 denotes a RAM, development data for recording, a reception buffer for temporarily storing received data (recording command and recording data) from the host device, and a work memory for storing necessary information such as recording speed Used as a work area for the CPU 301.

  A ROM 303 is a recording control program executed by the CPU 301 for transferring recording data to the recording head to perform recording, a program for controlling carriage and paper feed, a printer emulation program, a recording font, and the like. Storing.

  Reference numeral 305 denotes an ASIC (composite control unit) that has the recording head 7 and the power LED 307 to be turned on, off, and blinking, the power SW 309 and the cover open SW 311 are detected, and the paper detection sensor 313 is detected.

  Reference numerals 314 to 316 denote motor drivers that drive and control each motor. Reference numerals 317 to 319 denote motors connected to the motor driver, which are driven and controlled by the motor driver according to instructions from the CPU 301. A DC servo motor is used as the carriage motor 8 to perform servo control, and a stepping motor that can be easily controlled by the CPU 301 is used as the paper feed motor 318 and the paper feed motor 319.

  An I / F controller 320 is connected to a host device such as a computer via the I / F 321 and receives a recording command and recording data transmitted from the host device. The I / F 321 is a bidirectional I / F that transmits error information of the inkjet recording apparatus, and various I / Fs such as a Centro I / F and a USB I / F are used.

  330 is a non-volatile, writable EEPROM for storing registration adjustment values, the number of printed sheets, the number of ejected ink dots, the number of ink tank replacements, the number of replacements of the recording head, the number of executions of the cleaning operation, and the like. . The written contents are retained even when the power is turned off.

  FIG. 4 is a graph showing changes in ejection speed with respect to pulse width, with a voltage applied to the heater being constant (20 v) in a recording head capable of ejecting 2 ng of ink.

  In the case where the applied voltage is constant, ink is ejected from the nozzle when a certain pulse width is reached, and the ink ejection speed increases as the pulse width increases, but when the pulse width exceeds a certain value, the ejection speed becomes constant. In general, at the time of actual recording, a voltage having a pulse width in a region where the discharge speed is constant, such as a region 42 (pulse width: 1.0 μsec or more and 2.0 μsec or less) in FIG. The recording head is driven and controlled to keep the speed constant. The recording head is similarly driven and controlled during preliminary ejection.

  When a voltage having a pulse width in region 41 (pulse width: 0.6 μsec or more and 0.7 μsec or less) in FIG. 4 is applied and ink ejection is observed, the ejection speed is 6.0 m / sec or more and 9.0 m / sec or less. . When a voltage having a pulse width in a region 42 (pulse width: 1.0 μsec or more and 2.0 μsec or less) in FIG. 4 was applied to observe ink discharge, the discharge speed was about 13.0 m / sec.

  FIG. 5 shows a recording head capable of ejecting 2 ng of ink, ejecting ink at different ejection speeds, and taking three levels of distances from the ejection port to the recording medium of 0.5 mm, 1.0 mm, and 2.0 mm. It is a figure which shows the result of having investigated whether the ink reached | attained the medium. In FIG. 5, when ink reaches, it is indicated by ◯, and when it does not reach, it is indicated by ×.

  From the results of FIG. 5, it was found that when the ejection speed of 2 ng of ink is 5.0 m / sec or less, the ink does not reach the recording medium 0.5 mm away from the ejection port. Further, it was found that when the ejection speed of 2 ng ink was 6.0 m / sec or more and 9.0 m / sec or less, the ink did not reach the recording medium 1.0 mm away from the ejection opening.

  From the results of FIGS. 4 and 5, when a voltage having a pulse width in the region 42 of FIG. 4 is applied, the ink droplet reaches the recording medium when the distance from the ejection port to the recording medium is 2.0 mm. On the other hand, when a voltage having a pulse width in the region 41 in FIG. 4 is applied, the ink droplet does not reach the recording medium when the distance from the ejection port to the recording medium is 2.0 mm.

  In addition, when a voltage having a pulse width of the region 41 in FIG. 4 is applied, the ink does not reach the recording medium separated by 2.0 mm, but 2 ng of ink is ejected and does not affect the next ejected ink. It could be confirmed. For this reason, it was found that ink sticking can be eliminated by applying a voltage having a pulse width in the region 41 of FIG. 4 and discharging the ink thickened by moisture evaporation near the discharge port.

  However, when a voltage having a pulse width in the region 41 in FIG. 4 is applied, ink droplets that do not reach the recording medium 2.0 mm away become mist, float in the ink jet recording apparatus main body, and cause contamination of the ink jet recording apparatus main body. I also knew it could be.

  Therefore, in this embodiment, the first preliminary ejection that ejects the same amount of ink at the time of recording at the same ejection speed and the same amount of ink as at the time of recording are ejected at a slow ejection speed that does not reach the recording medium. The second preliminary discharge is set. The first preliminary ejection is performed by moving the recording head to a place outside the recording area. The second preliminary ejection is performed on the recording medium, but the ejected ink droplet does not reach the recording medium. The first preliminary ejection and the second preliminary ejection are switched in consideration of shortening the recording time and contamination of the ink jet recording apparatus main body. Thus, it was possible to perform recording on a recording medium by stable ink ejection while shortening the recording time.

  The recording head used in this embodiment will be described below.

  FIG. 6 is a schematic diagram of a recording head capable of recording using inks of three colors of cyan (C), magenta (M), and yellow (Y) in this embodiment. M and 66 indicate the arrangement of the discharge ports for discharging Y ink.

  As shown in FIG. 6, the ejection ports for ejecting the respective inks all have the same circumference and are about 10 μm. Further, the recording head can eject 2 ng of ink from all the ejection ports.

  FIG. 7 is a schematic diagram showing the scanning range of the recording head, the conveyance area of the recording medium, and the cap position in the ink jet recording apparatus main body. Reference numeral 71 denotes a recording medium conveyance area, and recording is performed on the recording medium by the recording head reciprocating the scanning range indicated by 72 while ejecting ink. Conventionally, the preliminary ejection operation is generally performed at the cap position 73 that is the home position. However, in the present embodiment, only the first preliminary ejection that ejects ink at the ejection speed reaching the recording medium is performed. Perform at cap position 73.

  Further, recording in the direction from the cap position 73 to the recording medium conveyance area 71 with reference to the cap position 73 is referred to as forward recording, and recording in the direction from the recording medium conveyance area 71 to the cap position 73 is referred to as backward recording. .

  FIG. 8 shows respective pulse widths in the first preliminary discharge and the second preliminary discharge. When performing preliminary ejection, it is determined which preliminary ejection is performed, and the pulse width is selected to control the drive of the recording head. In this embodiment, the distance from the discharge port to the surface of the recording medium is set to 1.5 mm.

  FIG. 9 shows whether the first preliminary ejection or the second preliminary ejection is performed when the recording head shown in FIG. 6 and the ink jet recording apparatus shown in FIG. 7 are used. It is a flowchart to implement.

  When it is time to perform preliminary ejection in step S110, it is determined in step S120 whether the inkjet recording apparatus has received recording data. If it is determined in step S120 that print data has not been received, the ink jet printing apparatus is on standby, and the print head is located at the cap position 73 in FIG. For this reason, if it is determined in step S120 that print data has not been received, the first preliminary ejection is selected in step S130, and the first preliminary ejection is performed in step S140.

  On the other hand, if it is determined in step S120 that the recording data is received, it is determined in step S150 whether or not the outbound recording is being performed.

  If it is determined in step S150 that the return pass recording is being performed, the recording head has moved toward the cap position 73, so that after the recording is performed to the end of the recording medium, preliminary ejection is performed at the cap position 73. It can be judged that it is possible. Therefore, the first preliminary discharge is selected in step S160, and the first preliminary discharge is performed in step S170.

  If it is determined in step S150 that the forward recording is being performed, the recording head has moved away from the cap position 73. In this case, the second preliminary discharge is selected in step S180, and the second preliminary discharge is performed in step S190. When the preliminary ejection timing is reached during forward recording, in order to perform preliminary ejection at the cap position 73, an extra scan to return to the cap position 73 is performed once or until the recording head is reversed, and then the cap position 73 is reached. You have to do either of returning. Once the extra scanning to return to the cap position 73 is performed, the recording time becomes longer, wait until the recording head is reversed, and then return to the cap position 73 to increase the time to perform preliminary ejection, and recording in an unstable ejection state. Will do. Therefore, in this case, the second preliminary discharge is performed.

  When pre-ejection was performed only at the cap position when recording an A4 size photo image, it took about 180 seconds to complete the recording. However, when pre-ejection was performed as shown in the flowchart of FIG. 9, recording was completed in about 160 sec. . That is, the recording time can be shortened by about 20 seconds.

  Further, when all the preliminary ejections are performed by the second preliminary ejection, contamination in the ink jet recording apparatus due to mist proceeds rapidly. However, when all preliminary discharges are performed in the second preliminary discharge and an A4 size photo image is recorded, contamination when about 4000 to 4500 sheets are recorded is contaminated when predischarge is performed as shown in the flowchart of FIG. This is equivalent to contamination when 6000 sheets are recorded.

  As described above, by performing preliminary ejection as shown in the flowchart of FIG. 9, it is possible to realize an ink jet recording apparatus that balances between shortening the recording time and suppressing contamination in the ink jet recording apparatus.

  Further, as a method of determining which preliminary ejection is performed, it is detected whether the recording head is in a capping state at the capping position by a cap that protects the recording head, and which of the first preliminary ejection and the second preliminary ejection is performed. You may decide whether to implement. This is because when the recording head is in the capping state at the capping position, the recording time required when recording a small number of sheets is significantly shortened by reducing the first preliminary ejection and increasing the second preliminary ejection. For example, when one sheet is recorded by performing only the first preliminary ejection as the preliminary ejection, a recording time of 6.5 sec is required, and only one second preliminary ejection is performed as the preliminary ejection. In that case, it was 3 seconds. As described above, when recording is performed from the capping state, the recording time can be greatly shortened by performing only the second preliminary ejection as the preliminary ejection.

(Example 2)
The present embodiment is an example of an ink jet recording apparatus equipped with a recording head capable of ejecting the same color ink with different ejection amounts.

  FIG. 10 is a schematic diagram of a recording head capable of recording using three colors of CMY inks, and shows the arrangement of ejection openings for ejecting 104 C, 105 M, and 106 Y ink.

  As shown in FIG. 10, the discharge port arrays on the left side and the right side of each color have different peripheral diameters. The peripheral diameter of the discharge port on the left side of each color is about 10 μm, and 2 ng of ink can be discharged. On the other hand, the peripheral diameter of the right discharge port of each color is about 15 μm, and 5 ng of ink can be discharged. As described above, the recording head used in this example has a recording element capable of ejecting a relatively small amount of ink and a recording element capable of ejecting a large amount of ink. A recording head capable of ejecting ink.

  FIG. 11 is a graph showing the change in discharge speed with respect to the pulse width at a discharge port capable of discharging 5 ng of ink, with the voltage applied to the heater being constant (20 v).

  When the applied voltage is constant, ink is ejected from the nozzle when a certain pulse width is reached as in the case of the ejection port capable of ejecting 2 ng of ink shown in FIG. From there, the ink ejection speed increases as the pulse width increases, but when the pulse width exceeds a certain value, the ejection speed becomes constant.

  When ink discharge was observed by applying a voltage having a pulse width in the region 111 (pulse width: 0.7 μsec or more and 0.8 μsec or less) in FIG. 11, the discharge speed was 9.0 m / sec or more and 14.5 m / sec or less. . When a voltage having a pulse width in the region 112 (pulse width: 1.0 μsec or more and 2.0 μsec or less) in FIG. 11 was applied and ink discharge was observed, the discharge speed was about 17.0 m / sec.

  FIG. 12 shows a recording head capable of discharging 2 ng and 5 ng, changing the discharge speed to discharge ink, and taking three levels of distances from the discharge port to the recording medium: 0.5 mm, 1.0 mm and 2.0 mm. It is a figure which shows the result of having investigated whether the ink reached | attained the medium. In FIG. 10, when the ink has reached, it is indicated by ◯, and when it has not reached, it is indicated by ×.

  From the results of FIG. 12, it was found that when the ejection speed of 2 ng of ink was 5.0 m / sec or less, the ink did not reach the recording medium 0.5 mm away from the ejection port. Further, it was found that when the ejection speed of 2 ng ink was 6.0 m / sec or more and 9.0 m / sec or less, the ink did not reach the recording medium 1.0 mm away from the ejection opening. It was found that when the ejection speed of 5 ng ink was 9.0 m / sec or more, the ink reached the recording medium 2.0 mm away from the ink ejection opening.

  4, 5, 11, and 12, when a voltage having a pulse width in the region 42 in FIG. 4 or the region 112 in FIG. 11 is applied, when the distance from the ejection port to the recording medium is 2.0 mm. The ink droplet reaches the recording medium. On the other hand, when a voltage having a pulse width of the region 41 in FIG. 4 is applied only to the 2 ng ejection port, the ink droplet does not reach the recording medium when the distance from the ejection port to the recording medium is 2.0 mm.

  Therefore, in the present embodiment, in the recording head capable of ejecting inks having different ejection amounts for the same color, only the first preliminary ejection and the second ejection are performed for the ejection port arrays having relatively small ejection amounts as in the first embodiment. Set pre-discharge. Thus, in an ink jet recording apparatus provided with a recording head capable of ejecting different amounts of ink for the same color, recording on a recording medium can be performed by stable ink ejection while shortening the recording time.

  FIG. 13 shows the pulse width of the preliminary discharge of the 5 ng discharge port and the pulse width of each of the first preliminary discharge and the second preliminary discharge of the 2 ng discharge port. When performing preliminary ejection from the 2 ng ejection port, it is determined which preliminary ejection is to be performed, and the pulse width is selected to control the drive of the recording head. In this embodiment, the distance from the discharge port to the surface of the recording medium is set to 1.5 mm.

  FIG. 14 shows that when the recording head shown in FIG. 10 and the ink jet recording apparatus shown in FIG. 7 are used, only the first preliminary discharge or the second preliminary discharge is performed only for the preliminary discharge from the 2 ng discharge port. It is a flowchart which judges whether to perform and performs preliminary discharge. Detailed description of the same steps as those in the flowchart of FIG. 9 is omitted.

  First, in step S10, the ink jet recording apparatus receives recording data. In step S20, it is determined whether or not recording is performed only with ink droplets ejected from the ejection port that ejects a relatively small amount of ink from the recording mode received by the inkjet recording apparatus. If it is determined in step S20 that recording is not performed by only the ink droplets ejected from the ejection port that ejects a relatively small amount of ink, the process proceeds to step S130. Steps S130 and S140 are the same as those in the flowchart of FIG. 9, but after performing the first preliminary ejection in step S140, the process returns to step S10. On the other hand, if it is determined in step S20 that recording is performed only with ink droplets ejected from the ejection port that ejects a relatively small amount of ink, the process proceeds to step S150. Steps S150 to S190 are the same as those in the flowchart of FIG.

  When recording an A4-sized photo image with only ink droplets discharged from a discharge port that discharges a relatively small amount of ink, it takes about 360 seconds to complete recording when preliminary discharge is performed only at the cap position. On the other hand, when preliminary ejection was performed as in the flowchart of FIG. 14, recording was completed in about 320 seconds. That is, the recording time can be shortened by about 40 seconds.

  As described above, in this embodiment, in an ink jet recording apparatus equipped with a recording head capable of ejecting the same color ink with different ejection amounts, only ink droplets ejected from ejection ports that eject a relatively small amount of ink are used. When recorded, the recording time can be shortened.

(Example 3)
The present embodiment is an example of an ink jet recording apparatus that combines an airflow generation unit such as a fan for collecting ink droplets floating as mist.

  FIG. 15 shows the ink jet recording apparatus of the present embodiment, and a suction type fan 154 is installed on the opposite side of the cap position 73 across the recording medium conveyance area 71.

  In this ink jet recording apparatus, ink droplets ejected by the second preliminary ejection that does not reach the recording medium because the ink ejection speed is slow can be collected almost entirely by the effect of the airflow generation unit such as a fan. For this reason, even if the frequency of the second preliminary ejection is increased, contamination by ink mist in the ink jet recording apparatus hardly occurs.

  FIG. 16 shows whether the first preliminary ejection or the second preliminary ejection is performed when the recording head shown in FIG. 6 and the ink jet recording apparatus shown in FIG. 15 are used. It is a flowchart in the present Example to implement. The frequency of performing the second preliminary ejection that does not reach the recording medium because the ink ejection speed is low is higher than the flowchart shown in FIG. Detailed description of the same steps as those in the flowchart of FIG. 9 is omitted.

  Steps S110 and S120 are the same as those in the flowchart of FIG. However, if it is determined in step S120 that recording data has not been received, the process proceeds to step S160. If it is determined that recording data has been received, the process proceeds to step S180. Steps S160 to S190 are the same as those in the flowchart of FIG.

  In the present embodiment, when it is determined that the recording data is received, the second preliminary ejection is performed regardless of whether the forward recording or the backward recording is being performed. This is because almost all ink droplets ejected by the second preliminary ejection that does not reach the recording medium can be collected by the fan 154 because the ink ejection speed is slow.

When pre-ejection was performed only at the cap position when recording an A4 size photo image, it took about 180 seconds to complete the recording. However, when pre-ejection was performed as shown in the flowchart of FIG. 16, the recording was completed in about 140 sec. . That is, the recording time can be shortened by about 40 seconds. Further, in this embodiment, the contamination when about 4000 to 4500 sheets are recorded when all preliminary ejections are performed by the second preliminary ejection using a recording apparatus not equipped with a fan to record A4 size photo images. Contamination when recording about 10,000 to 15,000 sheets became equivalent.
As described above, in this embodiment, it is possible to further shorten the recording time and to suppress contamination due to mist in the ink jet recording apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an external perspective view showing a state where a cover of an ink jet recording apparatus that can suitably carry out the present invention is removed. It is a fragmentary perspective view which shows schematic structure of the drive mechanism of a carriage. 1 is a block diagram illustrating a control configuration of an ink jet recording apparatus that can suitably implement the present invention. It is the graph which showed the discharge speed change with respect to the pulse width. It is a figure which shows the result of having investigated whether the ink reached | attained the recording medium. It is a schematic diagram of a recording head. FIG. 3 is a schematic diagram illustrating a scanning range of a recording head, a recording medium conveyance region, and a cap position in an ink jet recording apparatus main body. This is the pulse width at the time of preliminary ejection. It is a flowchart which judges which of 1st preliminary discharge and 2nd preliminary discharge is implemented, and implements preliminary discharge. It is a schematic diagram of a recording head. It is the graph which showed the discharge speed change with respect to the pulse width. It is a figure which shows the result of having investigated whether the ink reached | attained the recording medium. This is the pulse width at the time of preliminary ejection. It is a flowchart which judges which of 1st preliminary discharge and 2nd preliminary discharge is implemented, and implements preliminary discharge. FIG. 3 is a schematic diagram illustrating a scanning range of a recording head, a recording medium conveyance region, and a cap position in an ink jet recording apparatus main body. It is a flowchart which judges which of 1st preliminary discharge and 2nd preliminary discharge is implemented, and implements preliminary discharge.

Explanation of symbols

7 Recording head 301 CPU
305 ASIC

Claims (8)

An ink jet recording apparatus that records an image on a recording medium by scanning a recording head that discharges ink from an ejection port in a direction orthogonal to the conveyance direction of the recording medium,
A first preliminary ejection that is performed at a position deviating from the recording medium with respect to the scanning direction at the same ejection speed as the ejection speed of the ink ejected when recording is performed, and the ink ejected from the ejection port is the recording Whether the preliminary ejection to be performed is performed as a second preliminary ejection to be performed on the recording medium at an ejection speed slower than the ejection speed of the ink ejected when performing the recording so as not to reach the medium. Determination means for determining according to at least one of the position of the head and the scanning direction;
Control means for controlling the recording head to perform preliminary ejection by either the first preliminary ejection or the second preliminary ejection at each predetermined timing in accordance with the judgment result of the judgment means;
An ink jet recording apparatus comprising: The first preliminary ejection is performed by applying a voltage having a pulse width applied when recording is performed on a recording element provided corresponding to the ejection port;
2. The ink jet recording apparatus according to claim 1, wherein the second preliminary ejection is performed by applying a voltage having a pulse width shorter than a pulse width applied when recording is performed to the recording element. .   The determination means determines whether or not the ink jet recording apparatus receives recording data at each of the timings, and determines that the first preliminary ejection is performed when it is determined that the recording data is not received. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus is provided.   When the determination means determines that the recording data is received, the home moves when the recording head is scanning in a direction toward a home position provided at a position off the recording medium at the timing. It is determined to perform the first preliminary discharge at a position, and when the recording head is scanning in a direction away from the home position at the timing, it is determined to perform the second preliminary discharge. The ink jet recording apparatus according to claim 3. A cap for protecting the recording head at a position removed from the recording medium;
The determination means determines whether or not the recording head is capped by the cap at each of the timings, and when determining that the recording head is capped by the cap, performs the first preliminary ejection in the cap. The inkjet recording apparatus according to claim 1, wherein the inkjet recording apparatus is determined as follows.   The inkjet recording apparatus according to claim 1, further comprising a collecting unit that collects the ink droplets ejected by the second preliminary ejection. The recording head has an ejection port that ejects a relatively large ink droplet and an ejection port that ejects a relatively small ink droplet,
The control means controls the discharge port for discharging relatively large ink droplets to perform the first preliminary discharge at each of the timings, and the discharge port for discharging relatively small ink droplets. The inkjet according to any one of claims 1 to 6, wherein control is performed so that the first preliminary discharge or the second preliminary discharge is performed according to a determination result of the determination unit at each of the timings. Recording device. A recovery method for an ink jet recording apparatus that records an image on a recording medium by scanning a recording head that discharges ink from an ejection port in a direction perpendicular to the conveyance direction of the recording medium,
A first preliminary ejection that is performed at a position deviating from the recording medium with respect to the scanning direction at the same ejection speed as the ejection speed of the ink ejected when recording is performed, and the ink ejected from the ejection port is the recording The pre-discharge, which is the second pre-discharge to be performed on the recording medium at a discharge speed slower than the discharge speed of the ink discharged when performing the recording so as not to reach the medium. A determination step of determining according to at least one of the position of the head and the scanning direction;
A control step of controlling the recording head to perform preliminary ejection by either the first preliminary ejection or the second preliminary ejection at each predetermined timing according to the judgment result in the judgment step;
A recovery method comprising:

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