JP2009214416A - Inkjet recorder and method for performing idling ejection for inkjet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recorder capable of preventing mist from being suspended in air by performing suction at an effective portion at an effective timing by using an exhaust unit such as an existing cooling fan so as to keep the number of components to the minimum, and a method for performing idling ejection for inkjet. <P>SOLUTION: An air suction duct 23 of the air exhaust unit comprises a mist suction hole 24 that is disposed at an idling ejection position and sucks mist of ink ejected for idling, a heat exhausting suction hole 22 for sucking heat in the recorder, and an air flow control valve 21 enabling either one of the mist suction hole 24 and the heat exhausting suction hole 22 to suck the air by means of an operation of a switching lever 20. A carriage 1 acts on the switching lever 20 of the air flow control valve 21 by an operation of moving a recording head to the air ejecting position so as to operate the lever, thereby enabling the mist suction hole 23 to suck the sir. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus and an ink jet idle discharge method.

  In an ink jet printer (ink jet recording apparatus), when an ink droplet is ejected, an unintended extremely small ink droplet may be ejected, and the ink droplet floats in the air. This ink droplet is called a mist, and the mist adheres to each part in the machine. If the mist adheres to a sensor part or the like, it may cause a malfunction of the printer. Of particular concern is contamination on encoder sensors for main / sub-scan control.

  As a method for preventing such a malfunction caused by mist, there are already known techniques for avoiding adhesion to a sensor unit by airflow design and suction removal technology using a pump.

  For example, in Patent Document 1, for the purpose of preventing in-machine contamination due to ink, the position, moving speed, and moving direction of a carriage on which a recording unit is mounted is detected, and according to the result, the air volume does not affect the recording unit. An apparatus capable of generating maximum output by a fan and efficiently collecting mist is disclosed.

  In Patent Document 2, for the purpose of preventing in-machine contamination due to ink, a suction port is provided at the lower part of the ink receiving sponge during borderless printing to suck mist, and the suction port is a suction in the cap used during head maintenance. An apparatus is disclosed that is used in common with a conventional pump and performs intake by switching a valve at a timing when head maintenance is not performed.

  However, the conventional airflow control methods require the installation of a dedicated fan, and there are problems that suction cannot be performed at an effective site or timing.

JP 2006-341571 A JP 2006-205666 A

  The present invention has been made in view of the above-mentioned problems in the prior art, and by using an exhaust unit such as an existing cooling fan, the number of parts is minimized and suction is performed at an effective part and timing. An object of the present invention is to provide an ink jet recording apparatus and an ink jet idle discharge method that suppress the floating of mist.

The present invention provided to solve the above problems is as follows.
[1] A recording head (recording heads 9a and 9b) having a nozzle array (nozzle arrays 10y, 10m, 10c, and 10k) in which a plurality of nozzles that eject ink are arranged in at least one direction (sub-scanning direction) is mounted. A carriage (carriage 1), conveying means (main scanning motor 3, pulley 4) for scanning the carriage in a direction (main scanning direction) orthogonal to the sub-scanning direction, and a predetermined position (empty ejection position) in the main scanning direction An empty discharge tank (empty discharge tank 11) that receives ink discharged from the recording head that has moved to the inside, an intake duct having an intake port inside the apparatus, and an exhaust device (cooling fan 12) connected to the intake duct. In the ink jet recording apparatus (FIG. 1), the air intake duct is disposed at the idle ejection position and the idle ejection ink is mixed. A mist intake port (mist inlet port 24) for intake of the strike, an exhaust heat intake port (exhaust heat intake port 22) for intake of heat inside the apparatus, and the mist intake port by operating a switching lever (switching lever 20). And an airflow control valve (airflow control valve 21) that enables intake of either the exhaust heat intake port, and the carriage moves to the switching lever of the airflow control valve by scanning to move the recording head to the idle discharge position. An ink jet recording apparatus (FIGS. 2 and 3), wherein the lever is operated to operate the lever so that the mist inlet can be sucked.
[2] The inkjet recording apparatus according to [1] (FIG. 4), wherein the mist intake port is disposed inside the empty discharge tank.
[3] The upper cover of the empty discharge tank is provided with a plurality of openings (openings 31a and 31b) through which empty discharged ink can pass, and recording on the opening closest to the mist intake port. 2. The ink jet recording apparatus according to [2], wherein idle ejection is performed only from the head (FIG. 5).
[4] When performing idle ejection from a plurality of recording heads, the target recording heads are sequentially moved one by one on the slit closest to the mist intake port by scanning a carriage to perform idle ejection. The ink jet recording apparatus according to [3] (FIG. 5).
[5] A recording head (recording head 9a, 9b) having a nozzle array (nozzle arrays 10y, 10m, 10c, 10k) in which a plurality of nozzles for ejecting ink are arranged in at least one direction (sub-scanning direction) is mounted. A carriage (carriage 1), conveying means (main scanning motor 3, pulley 4) for scanning the carriage in a direction (main scanning direction) orthogonal to the sub-scanning direction, and a predetermined position (empty ejection position) in the main scanning direction An empty discharge tank (empty discharge tank 11) that receives ink discharged from the recording head that has been moved to the position, and a mist intake port (mist intake port 24) that intakes the mist of the ink discharged at the empty discharge position. ) And an exhaust heat intake port (exhaust heat intake port 22) for taking in heat inside the device, and an exhaust device (cooling fan) connected to the intake duct. And an exhaust unit including an air flow control valve (air flow control valve 21) that allows intake of either the mist intake port or the exhaust heat intake port by operating a switching lever (switching lever 20). An ink jet idle discharge method in a recording apparatus (FIGS. 1 and 2), wherein a carriage is operated on a switching lever of the air flow control valve by scanning to move the recording head to an idle discharge position, and the mist is operated. An ink-jet idle discharge method (FIG. 3), wherein after the intake port is made capable of intake, idle discharge is performed from the recording head.
[6] The above-mentioned [5], wherein the mist intake port is disposed inside the empty discharge tank, and performs the idle discharge from the recording head while sucking in from the empty discharge tank. Inkjet empty discharge method (FIG. 4).
[7] The upper cover of the empty discharge tank is provided with a plurality of openings (openings 31a and 31b) through which the ink discharged empty can pass, and recording on the opening closest to the mist intake port. The ink jet idle discharge method according to [6], wherein the idle discharge is performed only from the head (FIG. 5).
[8] Only the recording head on the opening closest to the mist intake port is ejected idle, and then another recording head is moved to the opening closest to the mist intake port by scanning the carriage to perform idle ejection. The inkjet idle discharge method according to [7] (FIG. 5), wherein the inkjet recording apparatus performs the idle discharge sequentially from a plurality of recording heads.

  According to the present invention, the increase in parts can be minimized, and suction can be performed at an effective portion / timing to effectively suppress mist floating. In addition to this, it is possible to expect an effect that the carriage stop time after idle ejection can be reduced to increase the throughput. In other words, by sharing the exhaust device (fan) for generating negative pressure in the intake duct with the existing exhaust device (cooling fan), the increase in the number of parts can be suppressed, and for the idle discharge operation with a large amount of mist generated. The mist can be sucked effectively by adjusting the intake location and the intake time. Conventionally, when the carriage moves after empty discharge, the mist floating in the empty discharge tank is wound up and fluttered in the machine, so the carriage stop time was set after empty discharge. Can contribute to the improvement of throughput.

Hereinafter, a conventional inkjet recording apparatus will be described.
FIG. 1 is a diagram for explaining the basic structure and printing mechanism of a conventional ink jet recording apparatus.
The carriage 1 is held by a guide lot 2 and is scanned in the main scanning direction by driving the main scanning motor 3 through a pulley 4 passed between the carriage 1 and the main scanning motor 3. For example, yellow (Y), cyan (C), magenta (M), and black (K) recording heads 9a and 9b for ejecting ink droplets of each color are mounted on the carriage 1. Each color ink can be ejected independently from the nozzle rows 10y, 10m, 10c, and 10k in which a plurality of ink ejection nozzles are arranged in at least one direction (sub-scanning direction) for each color. The recording head 9a has nozzle rows 10y and 10m, and the recording head 9b has nozzle rows 10c and 10k.

  The position information of the carriage 1 is obtained by reading a pattern recorded at equal intervals on the encoder sheet 5 fixed to the apparatus housing while the encoder sensor 6 fixed to the carriage 1 moves and adding / subtracting the count. Obtainable.

  At the time of image formation, the encoder sensor 6 moves (scans) the carriage 1 in the main scanning direction while obtaining the position information of the carriage 1, and ejects ink droplets onto the recording medium at necessary positions. At this time, by performing the ink ejection operation once while moving the carriage 1 in the main scanning direction, an image can be formed on a band having the same width as the length of the nozzle row, and image formation for one band can be performed. When completed, the sub-scanning motor 7 is driven to move the recording medium in the sub-scanning direction, and the image forming operation for one band is repeated to form an image at an arbitrary location on the recording medium. .

  In addition, there are many heat sources such as a drive signal generation circuit for an ink ejection actuator and a motor in the inkjet recording apparatus during printing. For this reason, the cooling fan 12 is installed as needed for the management of the temperature of various devices and the temperature inside the apparatus. For example, an exhaust unit including an intake duct (not shown) having an intake port inside the apparatus and an exhaust device (cooling fan 12) connected to the intake duct is provided.

  By the way, the ink on the nozzle surface of the recording head is not ejected, and after a certain period of time has elapsed, the viscosity of the ink increases and the ejection characteristics deteriorate or ejection becomes impossible. For this reason, when the time has elapsed since the previous printing job, the maintenance mechanism 8 performs the nozzle surface maintenance by performing idle ejection for discarding thickened ink or wiping with a blade, etc. Maintain discharge characteristics.

  Further, depending on the chart to be printed even during printing, a nozzle that does not discharge ink droplets for a long time may be generated, and the ink discharge characteristics of such a nozzle will deteriorate. For this reason, in order to recover the ink ejection characteristics even during printing, the carriage 1 is scanned and moved onto the empty ejection tank 11 to perform printing hollow ejection in which a predetermined amount of ink droplets are ejected from all nozzles of the recording head. There is.

  When ejecting ink droplets, there may be a case where a very small ink droplet that is not the target is generated due to the division of the droplet or the reaction of the liquid surface after ejection. These are called mist because they float in the air without landing on the opposing surface of the nozzle. Mist may always occur when ink droplets are ejected. However, in the idle ejection operation in which all nozzles are ejected for a certain period of time, the amount of mist generated tends to increase. Mist floating in the air drifts in the aircraft and adheres to each part to contaminate the aircraft. If such mist adheres to various sensors, the sensor cannot perform normal detection and causes a malfunction of the machine. In particular, due to the arrangement, it easily adheres to the encoder sheet 5 and the encoder sensor 6, and malfunction of carriage scanning tends to be a problem.

The inventors have intensively studied to solve such a problem and have come up with the present invention.
Hereinafter, the ink jet recording apparatus and the ink jet idle ejection method according to the present invention will be described.
FIG. 2 shows a configuration of a main part in which the present invention is applied to the ink jet recording apparatus of FIG.
The ink jet recording apparatus according to the present invention includes an ink jet recording apparatus shown in FIG. 1, that is, a plurality of nozzle rows 10y, 10m, 10c, and 10k in which a plurality of nozzles that eject ink are arranged in at least one direction (sub-scanning direction). A carriage on which the recording head is mounted, 1, conveying means (main scanning motor 3, pulley 4) for scanning the carriage 1 in a direction (main scanning direction) orthogonal to the sub-scanning direction, and a predetermined position in the main scanning direction ( An empty discharge tank 11 for receiving ink discharged from the recording head moved to an empty discharge position), an intake duct having an intake port inside the apparatus, and an exhaust device (cooling fan 12) connected to the intake duct. In the inkjet recording apparatus including the exhaust unit, the intake duct 23 is disposed at the idle discharge position and is idled. The mist intake port 24 that sucks in the mist of the exhaust, the exhaust heat intake port 22 that sucks in the heat inside the device, and the switching lever 20 can be operated to intake either the mist intake port 24 or the exhaust heat intake port 22. And an airflow control valve 21.

  Specifically, among the intake ports of the intake duct 23, the exhaust heat intake port 22 is provided to perform intake near the main scanning motor 3, and the mist intake port 24 is positioned near the upper surface of the receiver (upper lid) of the empty discharge tank 11. It is provided for intake, and the opening on the side opposite to the intake port of the intake duct 23 is joined to the cooling fan 12. In addition, an air flow control valve 21 that serves as a switching valve for exhaust heat intake / mist suction is provided inside the intake duct 23, and either the exhaust heat intake port 22 or the mist intake port 24 is activated by the operation of the valve. The structure allows selection of whether to generate negative pressure. Further, the switching lever 20 is pushed by the casing of the carriage 1 when the carriage 1 moves onto the empty discharge tank 11, and the switching lever 20 connected to the airflow control valve 21 is operated, and the valve of the airflow control valve 21 is operated. Switching is performed so that a negative pressure is generated at the mist inlet 24.

FIG. 3 shows a state where the airflow control valve 21 is switched during the idle discharge operation of the recording head.
When the switching lever 20 is pushed by the carriage 1, the switching lever 20 rotates around the fulcrum 20 a (rotates in the clockwise direction in the figure) and at the opposite side of the force point of the switching lever 20 from which the carriage 1 pushes. The air flow control valve 21 connected to the end rotates and closes the exhaust heat intake port 22, and the path of the intake duct 23 is switched to generate a negative pressure at the mist intake port 24. Thereafter, an idle ejection operation is performed from the recording head, and the mist generated at that time is sucked from the mist intake port 24. Further, a filter is installed in the cooling fan 12 or the intake duct 23, and after removing mist with the filter, only clean air is discharged outside the apparatus. Accordingly, it is possible to prevent mist from adhering to the encoder sheet 5, the encoder sensor 6, and the like, and to prevent a carriage scanning malfunction.

  In the ejection operation to the empty ejection tank 11 performed during printing, the carriage 1 returns to the printing position on the recording medium immediately after the completion of ejection, thereby minimizing a decrease in throughput. However, since the mist generated during the idle discharge drifts in the apparatus for a certain period of time depending on the size of the droplets and the state of the airflow, if the carriage 1 starts moving immediately after the idle discharge, an airflow is generated and the empty discharge tank 11 is generated. There was a case where the mist drifting in the air flew up inside the aircraft. Therefore, in the conventional ink jet recording apparatus, the carriage 1 is stopped for a certain period of time after the end of the discharge, and control for waiting for a relatively large drop of mist to fall is performed, thereby reducing the amount of mist rising. On the other hand, since the mist is sucked in the ink jet recording apparatus of the present invention, the mist does not rise due to the carriage movement, and the pause time of the carriage 1 can be reduced, so that the throughput can be improved.

  After the idle ejection operation, the carriage 1 moves to the printing position on the recording medium, and the carriage 1 moves away from the switching lever 20, so that the switching lever 20 rotates in the reverse direction around the fulcrum 20a as compared with the idle ejection operation. While rotating in the counterclockwise direction in the figure, the airflow control valve 21 connected to the end (action point) opposite to the end (power point) pressed by the carriage 1 of the switching lever 20 rotates and moves. Thus, the exhaust path connected to the mist intake port 24 is closed, and the path of the intake duct 23 is switched to generate a negative pressure at the exhaust heat intake port 22 (FIG. 2). Therefore, during the printing operation, the internal heat generated from the main scanning motor 3 and others is sucked and discharged outside the apparatus.

Here, the mist intake port is preferably disposed inside the empty discharge tank 11.
FIG. 4 shows a configuration in which the mist intake port is disposed inside the empty discharge tank 11.
A mist suction port 30 of the intake duct 23 is connected to the empty discharge tank 11, and a slit-like shape is provided in the upper lid of the empty discharge tank 11 so as to allow ink discharged in an empty manner to pass through the recording heads 9 a and 9 b. The vicinity of the upper surface of the empty discharge tank 11 is sucked from the openings 31a and 31b. For example, when the mist intake port 24 is arranged at a position on the upper lid of the empty discharge tank 11 as shown in FIG. 2, the ink droplet discharged from the recording head until the drop trajectory reaches the empty discharge tank 11. Therefore, the airflow generated by the suction of the mist intake port 24 is bent, and there is a possibility of landing on the upper cover surface of the empty discharge tank 11 without falling to the openings 31a and 31b of the empty discharge tank 11. In this case, the landed ink droplets accumulate and cause troubles such as staining the nozzle surface of the recording head. On the other hand, if the air is sucked from the mist intake port 30 arranged inside the empty discharge tank 11 as shown in FIG. 4, the air is sucked from the openings 31a and 31b. 11 can be landed.

  In the configuration of FIG. 4, it is preferable to perform idle ejection only from the recording head on the opening closest to the mist inlet 30. Further, when performing idle ejection from a plurality of recording heads, it is preferable to perform idle ejection by sequentially moving the target recording heads one by one over the opening closest to the mist inlet 30 by scanning the carriage 1. .

A method of controlling the idle discharge operation will be described with reference to FIG. Here, the figure which looked at the empty discharge tank 11 from the inkjet recording device front is shown.
The carriage 1 is held by a guide rod 2 and scanned in the longitudinal direction (left and right in the figure) of the guide rod 2, performs a printing operation on the recording medium on the recording medium conveyance unit 42, and is empty on the empty discharge tank 11. Discharge.

  During the idle discharge operation, the idle discharge is normally performed in a state where the recording heads 9 a and 9 b are directly above the openings 31 a and 31 b of the idle discharge tank 11. However, the cooling fan 12 generates a negative pressure from the mist intake port 30. When performing suction, the opening 31b near the mist inlet 30 in the empty discharge tank 11 can suck mist with a stronger suction than the opening 31a far from the mist inlet 30. Therefore, as shown in FIG. 5, when performing the idle discharge to the empty discharge tank 11 having a plurality of openings 31a and 31b, a recording head with insufficient mist suction is generated due to the difference in suction force between the openings 31a and 31b. (In the case of FIG. 5, the recording head 9a).

  Therefore, in the present invention, the idle ejection is performed only on the opening 31b having a strong suction force. When the position of the carriage 1 is in the state shown in FIG. 5, only the recording head 9b is ejected and the idle ejection from the recording head 9a is performed. Is performed in a state where the carriage 1 is moved to the right in the drawing and the recording head 9a is disposed on the opening 31b. Since the carriage 1 is stopped or the speed is limited at the moment of idle ejection of each recording head, it takes a little time to return to the printing operation rather than idle ejection simultaneously for all recording heads. More effective mist suction can be performed to prevent the mist from floating in the machine.

  Although the present invention has been described with the embodiments shown in the drawings, the present invention is not limited to the embodiments shown in the drawings, and other embodiments, additions, modifications, deletions, etc. Can be changed within the range that can be conceived, and any embodiment is included in the scope of the present invention as long as the effects and advantages of the present invention are exhibited.

It is the schematic which shows the structure of the conventional inkjet recording device. 1 is a schematic diagram illustrating a main configuration of an ink jet recording apparatus according to the present invention. It is the schematic which shows the state by which the airflow control valve was switched in the inkjet recording device of FIG. It is the schematic which shows another principal part structure of the inkjet recording device which concerns on this invention. FIG. 5 is an explanatory diagram of a method for controlling the idle ejection operation in the inkjet recording apparatus of FIG. 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Carriage 2 Guide rod 3 Main scanning motor 4 Pulley 5 Encoder sheet 6 Sender sensor 7 Sub scanning motor 8 Maintenance mechanism 9a, 9b Recording head 10y, 10m, 10c, 10k Nozzle row 11 Empty discharge tank 12 Cooling fan 20 Switching lever 20a Support point 21 Airflow control valve 22 Exhaust heat intake port 23 Intake duct 24, 30 Mist intake port 31a, 31b Opening 42 Recording medium transport unit

Claims (8)

A carriage on which a recording head having a nozzle array in which a plurality of nozzles that eject ink are arranged in at least one direction (sub-scanning direction) is mounted, and the carriage is scanned in a direction (main scanning direction) perpendicular to the sub-scanning direction. Conveying means, an empty discharge tank that receives ink discharged from the recording head moved to a predetermined position (empty discharge position) in the main scanning direction, an intake duct having an intake port inside the apparatus, and the intake duct In an inkjet recording apparatus comprising an exhaust unit comprising an exhaust device
The intake duct includes a mist intake port that is disposed at the idle discharge position and sucks in the mist of the ink that has been ejected, an exhaust heat intake port that intakes heat inside the apparatus, and a mist intake port that is operated by operating a switching lever. And an airflow control valve that enables intake of any of the exhaust heat intake ports,
An ink jet recording apparatus, wherein a carriage acts on a switching lever of the airflow control valve to perform a lever operation by scanning to move the recording head to an idle discharge position, thereby allowing the mist intake port to be inhaled.   The inkjet recording apparatus according to claim 1, wherein the mist intake port is disposed inside the empty discharge tank. The upper lid of the empty discharge tank is provided with a plurality of openings through which empty discharged ink can pass.
3. The ink jet recording apparatus according to claim 2, wherein idle ejection is performed only from the recording head on the opening closest to the mist inlet. When performing idle ejection from multiple recording heads,
4. The ink jet recording apparatus according to claim 3, wherein the target recording head is sequentially moved one by one on the slit closest to the mist intake port by scanning a carriage to perform idle ejection. A carriage on which a recording head having a nozzle row in which a plurality of nozzles that eject ink are arranged in at least one direction (sub-scanning direction) is mounted;
Conveying means for scanning the carriage in a direction (main scanning direction) perpendicular to the sub-scanning direction;
An empty discharge tank for receiving ink discharged idle from the recording head moved to a predetermined position (empty discharge position) in the main scanning direction;
An air intake duct having a mist intake port that is disposed at the idle discharge position and sucks the mist of the ink that is ejected idle and an exhaust heat intake port that sucks heat inside the apparatus, an exhaust device connected to the intake duct, and a switching lever An inkjet discharge method in an inkjet recording apparatus, comprising: an exhaust unit comprising an airflow control valve that enables intake of either the mist intake port or the exhaust heat intake port by lever operation;
The carriage is operated by operating the switching lever of the airflow control valve by scanning to move the recording head to the idle discharge position, the lever is operated, and after the mist intake port can be sucked, idle discharge is performed from the recording head. An inkjet empty discharge method characterized by the above. The mist inlet is disposed inside the empty discharge tank,
6. The inkjet idle discharge method according to claim 5, wherein the idle discharge from the recording head is performed while suctioning from the inside of the empty discharge tank. The upper lid of the empty discharge tank is provided with a plurality of openings through which empty discharged ink can pass.
The ink jet idle discharge method according to claim 6, wherein the idle discharge is performed only from the recording head on the opening closest to the mist inlet.   Performing the idle ejection of only the recording head on the opening closest to the mist intake port, and then performing the idle ejection by moving another recording head over the opening closest to the mist intake port by scanning the carriage. 8. The ink jet idle ejection method according to claim 7, wherein the inkjet idle ejection is performed sequentially and the idle ejection is performed from a plurality of recording heads.

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