JP5686276B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an ink jet type image forming apparatus that forms an image on a recording material by adhering ink droplets ejected from an ejection port of a recording head to the recording material.

  This type of image forming apparatus is mainly known as a product such as a printer, a facsimile machine, a copying machine, a plotter, and a complex machine of these. An ink jet image forming apparatus ejects ink droplets from a recording head onto a recording material to form an image (recording, printing, printing, and printing may be used synonymously). The recording material is not limited to paper, but includes OHP or the like, which means that ink droplets constituting an image can be attached, and is also referred to as an image recording medium, a recording medium, or a recording medium. Sometimes. Inkjet image forming apparatuses include a serial type image forming apparatus that forms an image by ejecting ink droplets while the recording head moves in the main scanning direction, and ink droplets that are ejected without the recording head moving. Thus, there is a line type image forming apparatus using a line type head for forming an image.

  The “image forming apparatus” in this specification means an apparatus that forms an image by ejecting ink droplets onto a recording material such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics and the like. To do. In this “image formation”, not only an image having a meaning such as a character or a figure is applied to the recording material, but also an image having no meaning such as a pattern is applied to the recording material (simply ink droplets). To land on the recording material). The “ink” to be ejected is not limited to what is generally called ink, and is not particularly limited as long as it is liquid when ejected. Thus, for example, DNA samples, resists, pattern materials, and the like are also included. In addition, the “image” is not limited to an image provided on a plane, but includes an image provided on a three-dimensional object or an image formed by modeling the three-dimensional object itself.

  Inkjet image forming apparatuses perform an ink suction process for sucking ink from the ejection ports formed on the ejection surface of the recording head at a predetermined timing during non-operation in order to maintain the ejection performance of the recording head. is there. In this ink suction process, first, the ejection surface of the recording head is covered with a cap member to seal the inside of the cap member, and in this state, the inside of the cap member is sucked using suction means. Thereby, as a result of the ink in the recording head being sucked out from the ejection port on the ejection surface of the recording head, ink clogging can be eliminated or the recording head can be reliably filled with ink.

FIGS. 29A to 29E show ink suction processing in a general vertical discharge type image forming apparatus that discharges ink droplets onto a recording material in a state where the discharge surface of the recording head is directly below the vertical direction. It is explanatory drawing for demonstrating.
This image forming apparatus is a serial type image forming apparatus, and a maintenance unit including a cap member 1011 is disposed outside the image forming area of the recording head 1007 in the main scanning direction. When the recording head 1007 is moved to the maintenance unit as shown in FIG. 29A during the ink suction process, as shown in FIG. 29B, the ejection surface of the recording head 1007 facing downward in the vertical direction is moved. A capping operation for covering with the cap member 1011 is performed from below. Thereby, the inside of the cap member 1011 covering the discharge surface is in a sealed state. Then, when the inside of the cap member 1011 is sucked by the suction pump 1050 connected to the suction port provided in the cap member 1011, the cap member 1011 is attracted to the ejection surface of the recording head 1007 and the sealing inside the cap member is improved. At the same time, the inside of the cap member has a negative pressure, and ink suction processing is performed in which the ink in the recording head sucks out of the ejection port on the ejection surface. At this time, the sucked ink is discharged from the suction port to the suction pump 1050 side, but a part of the ink stays inside the cap member 1011 as shown in FIG. Thereafter, when the operation of the suction pump 1050 is stopped, the suction force of the cap member 1011 with respect to the ejection surface of the recording head 1007 is weakened, and the cap member 1011 can be easily separated from the recording head 1007. As shown in FIG. 29D, a decap operation is performed to separate the cap member 1011 from the recording head 1007, the inside of the cap member 1011 is opened to the atmosphere, and then the suction pump 1050 is operated again. As a result, as shown in FIG. 29E, the ink accumulated in the cap member 1011 is discharged from the suction port to the suction pump 1050 side. In the image forming apparatus of this example, since the ink suction process is performed with the ejection surface of the recording head 1007 facing directly below in the vertical direction, the cap facing the ejection surface of the recording head 1007 is shown at the time of the decap shown in FIG. The opening surface of the member 1011 is in a state of facing directly above the vertical direction. For this reason, there is almost no fear that ink accumulated inside the cap member 1011 spills outside the cap member during decap.

  On the other hand, in recent years, a horizontal ejection type image forming apparatus that ejects ink droplets onto a recording material in a state where the ejection surface of the recording head is substantially parallel to the vertical surface is known (Patent Document 1). . The horizontal discharge type image forming apparatus can realize an apparatus layout that cannot be realized by a general vertical discharge type image forming apparatus, and is expected to reduce the size and cost of the apparatus.

  However, in such a horizontal discharge type image forming apparatus, during the ink suction process, in a decap operation similar to that of the vertical discharge type image forming apparatus, ink accumulated in the cap member spills out during the decap. Hereinafter, this point will be described with reference to the drawings.

30A and 30B are explanatory diagrams for explaining the ink suction process in the horizontal discharge type image forming apparatus.
In the horizontal discharge type image forming apparatus, normally, during the ink suction process, as shown in FIG. 30A, the discharge surface of the recording head 1107 facing right in the vertical direction is covered with a cap member 1111 from the horizontal direction. Perform capping operation. Then, when a suction operation is performed by a suction pump (not shown), the cap member 1111 is attracted to the ejection surface of the recording head 1107, the sealed state inside the cap member is increased, and the inside of the cap member becomes negative pressure, and the inside of the recording head The ink is sucked out from the ejection port on the ejection surface. At this time, since the inside of the cap member 1111 is in a hermetically sealed state, ink does not leak from a contact portion between the cap member 1111 and the ejection surface of the recording head 1107. A part of the ink sucked out by such a suction operation stays in the cap member 1111 as shown in FIG. Here, as in the case of the vertical discharge type image forming apparatus, when the decap operation is performed to stop the operation of the suction pump and move the cap member 1111 away from the recording head 1107, the opening surface of the cap member 1111 becomes the vertical surface. Since they are parallel, the ink in the cap member spills out from the opening surface.

Patent Document 1 discloses a configuration in which ink in a cap member can be removed in a horizontal discharge type image forming apparatus before decap after ink suction processing.
More specifically, when the ink in the cap member is removed before the decap, the ink flows into the cap member 1111 through the ejection port of the recording head 1107 if the cap member is kept sealed, and the cap member The ink inside cannot be removed. Therefore, it is necessary to perform the suction operation after the inside of the cap member 1111 communicates with the atmosphere before decap and the inside of the cap member is opened to the atmosphere. In the image forming apparatus disclosed in Patent Document 1, the adsorbing portion of the cap member adsorbing to the ejection surface is formed of a soft material, and a notch groove (communication hole) is provided in a part of the adsorbing portion. During the ink suction process, the cap member is pressed against the ejection surface of the recording head to compress and deform the suction portion, and the notch groove formed in the suction portion is closed to ensure a sealed state inside the cap member. On the other hand, after completion of the ink suction process, the cap member is slightly retracted from the ejection surface to partially restore the compression deformation of the suction portion of the cap member, and open the notch groove formed in the suction portion. The inside of the cap member is opened to the atmosphere. In this state, by performing the suction operation again with the suction pump, the ink accumulated in the cap member can be discharged. Therefore, by performing a decap operation thereafter, it is possible to decap without spilling ink inside the cap member.

  However, even if the configuration in which the ink in the cap member is removed before the decap after the ink suction process, as in the image forming apparatus described in Patent Document 1, the ink in the cap member is completely removed. Is difficult, and the ink in the cap member may spill during decap. In addition, even if the ink in the cap member does not sag during decap, there is a possibility that it may sag due to vibration of the cap member after decap. Even if the ink in the cap member is removed before the decap after the ink suction process, the ink adheres to the opening edge of the cap member that is in contact with the ejection surface of the recording head after the decap. There is also a risk of dripping. Therefore, even if the configuration in which the ink in the cap member is removed before the decap after the ink suction process is adopted, the ink accumulated inside the cap member or the ink adhering to the opening edge of the cap member may contaminate the inside of the machine. It is difficult to avoid.

  The above-described problems are not limited to the horizontal discharge type image forming apparatus in which the discharge surface of the recording head is substantially parallel to the vertical plane, and the same applies if the discharge surface of the recording head is not parallel to the horizontal plane. Can occur.

  The present invention has been made in view of the above background, and the object of the present invention is to drop ink remaining in the cap member or ink attached to the opening edge of the cap member during or after the decap. An object of the present invention is to provide an image forming apparatus capable of suppressing contamination inside the apparatus.

In order to achieve the above-mentioned object, the invention of claim 1 includes a recording head that discharges ink droplets to a recording material from an ejection port on an ejection surface that is not parallel to a horizontal plane, and an ejection surface of the recording head. A cap member for covering, and a moving means for relatively moving the cap member and the recording head so as to switch between a covering state in which the discharge surface of the recording head is covered by the cap member and an uncovering state in which the recording head is not covered. And an ink receiving member that is disposed at a position vertically below the opening edge of the cap member that contacts the discharge surface of the recording head and has a discharge port for discharging the received ink, and the ink receiving member. possess a discharge ink passage for conveying the ink to be discharged from the discharge port member to the discharge ink container, the ink receiving member, the coating state and the non That said discharge port in the vertical direction below the location where the discharge port on the discharge surface of the recording head when switching the covering state is located is configured to be positioned and is characterized in.
According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the moving means moves the cap member relative to each other to move the cap member relative to the recording head. The member is held by the cap member.
According to a third aspect of the present invention, in the image forming apparatus of the first or second aspect, the discharge port of the ink receiving member is located directly below the opening edge of the cap member. There is .
Also, the invention of claim 4, the image forming apparatus according to any one of claims 1 to 3, the ink receiving member, characterized in that it has a surface inclined downwardly toward the discharge port It is what.
According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the ink received by the ink receiving member is sucked from a discharge port provided in the ink receiving member. Ink receiving suction means for feeding the discharged ink container to the discharged ink container through the discharged ink passage is provided.
The invention of claim 6 is the image forming apparatus according to claim 5 , further comprising a cap suction means for sucking the inside of the cap member from the suction port provided in the cap member through the ink suction passage. The ink receiving suction means and the cap suction means are provided independently.
The invention according to claim 7 is the image forming apparatus according to claim 5 , further comprising a cap suction means for sucking the inside of the cap member from the suction port provided in the cap member through the ink suction passage. A common suction means is used as the ink receiving suction means and the cap suction means.
According to an eighth aspect of the present invention, in the image forming apparatus according to the seventh aspect , the discharged ink passage shielding means for shielding the discharged ink passage, and the shielding for shielding the discharged ink passage by controlling the discharged ink passage shielding means. And a control means for switching between the open state and the open state to be opened at a predetermined discharge ink passage switching timing.
According to a ninth aspect of the present invention, there is provided a recording head that discharges ink droplets to a recording material from an ejection port on an ejection surface that is not parallel to a horizontal plane, and a cap member that covers the ejection surface of the recording head And a moving means for moving the cap member and the recording head relative to each other so as to switch between a covering state where the discharge surface of the recording head is covered by the cap member and a non-covering state where the discharge surface of the recording head is not covered. An ink receiving member disposed at a position vertically below the opening edge of the cap member that contacts the ejection surface of the recording head and having a discharge port for discharging the received ink; and discharging from the discharge port of the ink receiving member The ink receiving member receives the discharged ink passage for transporting the ink to be discharged to the discharged ink container and the discharge port provided in the ink receiving member. Ink receiving suction means for sucking the ink and sending it to the discharged ink container through the discharged ink passage, and the inside of the cap member from the suction port provided in the cap member through the ink suction passage The suction means for the cap, the discharged ink passage shielding means for shielding the discharged ink passage, the shielded state for shielding the discharged ink passage by controlling the discharged ink passage shielding means, and the opened state for opening the predetermined ink. Control means for switching at the passage switching timing, and a common suction means is used as the ink receiving suction means and the cap suction means.
According to a tenth aspect of the present invention, in the image forming apparatus according to the eighth or ninth aspect, the discharge ink passage shielded by the discharge ink passage shielding means is crushed by applying external pressure, and the internal passage is shielded. The discharge ink passage shielding means is constituted by an external pressure applying member that applies the external pressure to the tube member. The flexible tube member is restored by releasing the external pressure to open the internal passage. It is characterized by that.
An eleventh aspect of the invention is the image forming apparatus according to any one of the eighth to tenth aspects, further comprising an ink suction passage shielding means for shielding the ink suction passage, wherein the control means includes the ink suction passage. The suction passage shielding means is controlled to switch between a shielding state for shielding the ink suction passage and an open state for opening the ink passage at a predetermined ink suction passage switching timing.
According to a twelfth aspect of the present invention, in the image forming apparatus of the eleventh aspect, the ink suction passage shielded by the ink suction passage shielding means is crushed by applying external pressure, and the internal passage is shielded. The ink suction passage shielding means is constituted by an external pressure applying member that applies the external pressure to the tube member. The flexible suction member is opened by restoring the external pressure to open the internal passage. It is characterized by this.
According to a thirteenth aspect of the present invention, in the image forming apparatus of the eleventh or twelfth aspect, the control means simultaneously blocks the discharged ink passage shielding means and the ink suction passage shielding means during a predetermined shielding period. It is characterized by doing.
According to a fourteenth aspect of the present invention, in the image forming apparatus according to any one of the eleventh to thirteenth aspects, the control means is configured to shield the discharged ink passage shielding means and the ink suction passage during a predetermined opening period. The means is simultaneously opened.
The fifteenth aspect of the present invention is the image forming apparatus according to any one of the eleventh to fourteenth aspects, wherein the discharged ink passage shielding means and the ink suction passage shielding means place the same shielding member in a predetermined position. Each of the shielding states and the open state is switched by moving, and the control means switches between the respective shield states and the open state by controlling the movement of the same shielding member. It is what.

  In the present invention, even if the ink remaining in the cap member at the time of or after the decap or the ink adhering to the opening edge of the cap member drips from the cap member, the ink can be received by the ink receiving member. Inflight contamination is suppressed. In addition, the ink received by the ink receiving member is discharged from the discharge port provided in the ink receiving member, and is transported to the discharged ink container through the discharged ink passage. Therefore, it can be avoided that the ink received by the ink receiving member is solidified on the ink receiving member as it is. As a result, it is difficult for the ink dripping from the ink receiving member to overflow from the ink receiving member, and the ink dripping from the cap member can be continuously received. Can be prevented in the long term.

  As described above, according to the present invention, it is possible to suppress the ink remaining in the cap member or the ink adhering to the opening edge of the cap member from dripping down and contaminating the inside of the machine during or after the decap. It is done.

1 is a schematic configuration diagram illustrating a main part of an inkjet printer according to a first embodiment. FIG. 2 is a schematic configuration diagram when a configuration around a recording head of the inkjet printer is viewed from a discharge direction (horizontal direction) of the recording head. It is a perspective view which shows the maintenance unit of the inkjet printer. FIG. 4 is a perspective view showing a state where the maintenance unit is separated into a capping unit, an idle discharge unit and a drive unit, and a wiping unit 140. It is a perspective view of the capping part. (A) And (b) is explanatory drawing which represented typically the structure and operation | movement which perform a nozzle suction process. It is explanatory drawing when the ink receiving member provided in the capping part is seen from diagonally upward. (A)-(c) is explanatory drawing when the structure of the tube crushing part provided in the capping part is seen from the upper direction. It is the perspective view which showed the drive part 130 with the capping part. It is a perspective view which shows the structure of the back side of the capping part. It is a perspective view which shows the structure of the back side of the capping part when it sees from the angle different from FIG. It is a perspective view of the wiping part. It is a flowchart which shows the flow of the maintenance process performed using the maintenance unit. (A)-(e) is a schematic diagram for demonstrating a structure and operation | movement when the cap and slider for suction in the maintenance unit are seen from a horizontal direction. (A)-(c) is explanatory drawing which shows the structure and operation | movement of a lock lever which fixes a rack and a slider. (A)-(c) is explanatory drawing which shows the structure of the ink receiving member in the modification 1. As shown in FIG. (A) And (b) is explanatory drawing of the ink receiving member which shows the other example in the modification 1. As shown in FIG. It is explanatory drawing which shows the suction means of the maintenance unit in the modification 2. (A)-(c) is a schematic diagram for demonstrating a structure and operation | movement when the suction cap of the maintenance unit in the modification 3 is seen from a horizontal direction. (A)-(c) is explanatory drawing which represented typically the structure and operation | movement of the capping part after the nozzle suction process completion | finish after the start of a wiping process in the printer which concerns on Embodiment 2. FIG. 3 is a flowchart illustrating an outline of a flow of maintenance processing performed before printing in the printer. In the printer, the positions I, II, and I of the guided portion on the guide rail when the rack is located at the forward position (covering position), the reverse position (non-covering position = wiping operation start position), and the wiping operation end position, respectively. It is explanatory drawing which shows III. 3 is a flowchart showing an outline of a flow of maintenance processing performed during continuous printing in the printer. 3 is a flowchart illustrating an outline of a flow of maintenance processing performed after printing in the printer. (A) And (b) is explanatory drawing which shows schematic structure of the L-shaped cap in the modification 4. As shown in FIG. It is explanatory drawing which shows schematic structure of the L-shaped cap in the modification 5. FIG. (A) is a top view of the L-shaped cap in the modified example 6, (b) is a side view of the L-shaped cap, and (c) illustrates the L-shaped cap together with the recording head. FIG. (A) And (b) is explanatory drawing which represented typically the operation | movement of the capping part in the modification 7. FIG. (A)-(e) is explanatory drawing for demonstrating the ink suction process in a general vertical discharge type image forming apparatus. (A) And (b) is explanatory drawing for demonstrating the ink suction process in a horizontal discharge type image forming apparatus.

Embodiment 1
Hereinafter, an embodiment of the present invention (hereinafter, this embodiment is referred to as “embodiment 1”) will be described with reference to the accompanying drawings, taking a serial printer as an ink jet recording apparatus as an image forming apparatus as an example. .
FIG. 1 is a schematic configuration diagram illustrating a main part of the ink jet printer according to the first embodiment.
FIG. 2 is a schematic configuration diagram when the configuration around the recording head of the ink jet printer is viewed from the ejection direction (horizontal direction) of the recording head.
In this ink jet printer, the carriage 3 is slidably held via a guide bush (bearing) 3a with respect to a guide rod 61 horizontally mounted between two main body side plates 60 located on the printer side. The carriage 3 moves in the direction along the guide rod 61 (main scanning direction) with the movement of the timing belt 5 spanned between the driving pulley 6A and the driven pulley 6B connected to the main scanning motor 4. .

  In the first embodiment, two recording heads 7A and 7B (indicated by a two-dot chain line in FIG. 2) are mounted on the carriage 3. Two nozzle rows each having a large number of nozzles (ejection ports) extending in the sub-scanning direction (recording material conveyance direction) are formed on the nozzle surfaces (ejection surfaces) of the recording heads 7A and 7B. Accordingly, the carriage 3 is provided with a total of four nozzle rows, and yellow (Y), cyan (C), magenta (M), and black (Bk) ink droplets are ejected from the nozzle rows, respectively. As the recording heads 7A and 7B, piezoelectric actuators such as piezoelectric elements, thermal actuators using liquid film boiling using electrothermal transducers such as heating resistors, shape memory alloy actuators using metal phase changes due to temperature changes, An electrostatic actuator using electrostatic force or the like provided as energy generating means for discharging ink (recording liquid) can be used. The carriage 3 is equipped with a head tank for each color for supplying ink of each color to the recording heads 7A and 7B. Ink is supplied to the head tank from a main tank (ink cartridge) (not shown) via an ink supply tube. In addition to the recording heads 7A and 7B that discharge ink droplets, a recording head that discharges a fixing treatment liquid (fixing ink) that improves the fixability of the ink by reacting with ink as an image recording liquid is provided. Also good.

  The nozzles of the recording heads 7A and 7B tend to cause nozzle clogging due to drying. For this reason, when the carriage 3 is not in operation such as when the operation is stopped due to a printing error or when the power is turned off, it is necessary to cover the nozzle surface with a cap member to keep the moisture and prevent nozzle clogging due to drying. In the first embodiment, two caps 111A and 111B as cap members are provided on the maintenance unit 100 arranged outside the image forming area in the main scanning direction of the recording head. The maintenance unit 100 may be provided on at least one end side outside the image forming area in the main scanning direction.

  Further, as shown in FIG. 1, a paper feed unit for feeding paper in the paper feed cassette 10 is provided at the bottom of the printer. In the paper feeding unit, a paper stacking unit (pressure plate) 11 is provided in the paper feeding cassette 10, and a plurality of sheets (recording materials) 12 are stacked on the paper stacking unit 11. When the paper 12 is fed from the paper stacking unit 11, the paper feeding roller 13 is brought into contact with the uppermost paper 12 and is driven to rotate. A separation pad 14 made of a material having a large friction coefficient is provided at a position facing the paper feed roller 13, and this separation pad 14 is urged toward the paper feed roller 13. With such a configuration of the sheet feeding unit, the uppermost sheet 12 sent out by the sheet feeding roller 13 is fed separately from other sheets.

  Further, as shown in FIG. 1, the printer includes a transport unit for transporting the paper 12 fed by the paper feed unit to an image recording area facing the nozzle surfaces of the recording heads 7A and 7B. The transport unit includes a transport belt 21 that transports the sheet 12 by attracting the sheet 12 to the surface with an electrostatic force, a guide 15 for guiding the transport direction of the sheet 12 fed from the sheet feed unit in a substantially vertical direction, A first reflective sensor (paper presence / absence detection sensor) 200 that detects the leading edge of the paper 12, a leading edge pressing roller 25 that is urged toward the conveying belt 21 by the pressing member 24, and a sheet 12 that is attached to the pressing member 24 A second reflection type sensor (sheet presence / absence detection sensor) 201 for detecting the leading edge. Further, a charging roller 26 constituting a charging unit for charging the surface of the transport belt 21 is also provided. The charging roller 26 is disposed so as to contact the surface of the transport belt 21 and rotate following the movement of the transport belt 21.

  The conveyor belt 21 is an endless belt and is stretched between the conveyor roller 27 and the tension roller 28. The conveyance roller 27 is rotationally driven from the sub-scanning motor 31 via the timing belt 32 and the timing roller 33, thereby conveying the paper 12 carried on the surface of the conveyance belt 21 upward in the vertical direction along the sub-scanning direction. To do. Further, a guide member 29 is provided on the inner peripheral surface side of the conveying belt 21 at a location corresponding to the image forming area facing the recording heads 7A and 7B.

As shown in FIG. 2, a disk-type encoder sheet 34 in which light transmitting parts and light non-transmitting parts are alternately arranged in the circumferential direction is attached to the shaft of the transport roller 27. An encoder sensor 35 for detecting the transmission part and the non-transmission part of the mold encoder sheet 34 is provided. The disk-type encoder sheet 34 and the encoder sensor 35 constitute an encoder 36. Based on the detection result of the encoder 36 and the detection result of the second sheet presence / absence detection sensor 201, the position of the sheet 12 in the sub-scanning direction can be grasped.
Further, the carriage 3 is provided with a linear encoder sheet 42 in which light transmitting portions and light non-transmitting portions are alternately arranged in a straight line. The linear encoder sheet 42 and the light transmitting portions are non-transmitting. An encoder sensor (not shown) composed of a transmissive photosensor for detecting the part is provided. Based on the detection result of the encoder sensor, the position of the carriage 3 in the main scanning direction can be grasped.

  In addition, as shown in FIG. 1, the printer includes a paper discharge unit for discharging the paper 12 on which images are recorded by the recording heads 7A and 7B. The paper discharge unit includes a separation claw 51 for separating the paper 12 from the transport belt 21, a paper discharge roller 52 and a paper discharge roller 53, and a paper discharge tray 54 for stocking the paper 12 to be discharged. Yes.

  In the printer according to the first embodiment configured as described above, the sheets 12 are separated and fed one by one from the sheet feeding unit, and the conveyance direction of the fed sheets 12 is guided vertically upward by the guide 15. The Then, after the leading edge of the sheet is detected by the first sheet presence / absence detection sensor 200, the sheet 12 sent onto the conveying belt 21 is pressed against the conveying belt 21 by the leading edge pressing roller 25, and the leading edge of the sheet is second. The sheet is detected by the sheet presence / absence detection sensor 201 and is transported vertically upward as the transport belt 21 moves. At this time, a voltage in which a positive (positive) output and a negative (negative) output are alternately repeated, that is, an alternating voltage is applied to the charging roller 26, and the conveying belt 21 is moved in the belt moving direction (sub-scanning direction). Positive and negative charges are alternately applied in a band shape with a predetermined width. When the sheet 12 is fed onto the conveyance belt 21 charged alternately with plus and minus, the sheet 12 is attracted to the conveyance belt 21 by electrostatic force, and the sheet 12 is moved in the sub-scanning direction as the conveyance belt 21 rotates. It is conveyed to.

  When an image is recorded by the recording heads 7A and 7B, the conveyance of the paper 12 by the conveyance belt 21 is temporarily stopped, and the recording heads 7A and 7B are driven according to the image signal while moving the carriage 3 in the main scanning direction. Then, ink droplets are ejected onto the stopped paper 12, and an image for one line is recorded. Thereafter, the paper 12 is conveyed in the sub-scanning direction by a predetermined amount and paused again, and then the next line is recorded. Upon receiving a recording end signal or a signal indicating that the rear end of the paper 12 has reached a predetermined position in the sub-scanning direction, the image forming operation is completed, and the paper 12 is discharged onto the paper discharge tray 54.

  As for the relationship between the scanning direction of the carriage 3 and the image formation, there are a unidirectional recording mode in which an image is formed only during scanning in one direction and a bidirectional recording mode in which an image is formed in both scanning in both directions. It is optional to set one of the modes according to the designation from the user and the print image, or to configure only one of the modes.

Next, the configuration and operation of the maintenance unit 100 will be described.
FIG. 3 is a perspective view showing the maintenance unit 100.
FIG. 4 is a perspective view showing a state in which the maintenance unit 100 is separated into the capping unit 110, the idle discharge unit 120, the drive unit 130, and the wiping unit 140.
The maintenance unit 100 is for recovering and maintaining the ejection performance of the recording heads 7A and 7B and for keeping the nozzles of the recording head moist during non-operation. The maintenance unit 100 includes a capping unit 110 for capping the recording heads 7A and 7B, an empty discharge unit 120 for receiving wings discharged from the recording heads 7A and 7B for maintenance, a capping unit 110, an empty discharge unit 120, and a below-described unit. The driving unit 130 transmits driving force to the suction pump, and the wiping unit 140 wipes the nozzle surfaces of the recording heads 7A and 7B. The maintenance unit 100 is screwed in a state of being positioned on the main body side plate 60 on the right side in FIG. 3 and 4, the recording heads 7A and 7B on the carriage 3 are positioned so as to face the maintenance unit 100 from the front side of the sheet.

FIG. 5 is a perspective view of the capping unit 110.
The capping unit 110 has two caps 111A and 111B, and covers the nozzle surfaces of the two recording heads 7A and 7B with the caps 111A and 111B, respectively, to keep the nozzles moist. In addition, the capping unit 110 performs nozzle suction processing for sucking out ink in the recording head from the nozzles of the recording head covered with the cap 111B to eliminate ink clogging and the like, and restores the ejection performance of the recording heads 7A and 7B. Processing to maintain is also performed. Embodiment 1 The caps 111A and 111B are attached to the rack 113 so as to be slidable in the horizontal direction (the front-rear direction in the figure), and the slide movement range is limited by a guide groove 113a provided in the rack 113. Yes. The caps 111 </ b> A and 111 </ b> B are urged forward from the rack 113 by the two upper and lower compression springs 118.

  The rack 113 on which the caps 111 </ b> A and 111 </ b> B are mounted can move in the horizontal direction (the front-rear direction in FIGS. 3 to 5) in response to the driving force from the driving unit 130. As a result, when the recording heads 7A and 7B are positioned at positions facing the caps 111A and 111B mounted on the rack 113, the caps 111A and 111B are moved closer to the recording heads 7A and 7B and the recording heads 7A and 7B are moved. The nozzle surfaces can be covered, or the caps 111A and 111B can be separated from the recording heads 7A and 7B so that the nozzle surfaces of the recording heads 7A and 7B can be uncovered. In the two caps 111A and 111B, the edge portion 111a of the opening facing the nozzle surfaces of the recording heads 7A and 7B is formed of an elastically deformable member such as rubber. Thus, when the caps 111A and 111B receive the urging force of the compression spring 118 and come into contact with the nozzle surfaces of the recording heads 7A and 7B, the edges 111a of the caps 111A and 111B are elastically deformed, and the openings of the caps 111A and 111B are opened. The nozzle surfaces of the recording heads 7A and 7B are closed with high sealing performance.

FIGS. 6A and 6B are explanatory diagrams schematically showing the configuration and operation for performing the nozzle suction processing.
The cap 111B for performing the nozzle suction process is provided with a suction port on the inner bottom surface, and one end of the suction tube 114A is connected to the suction port. A suction pump 150 as a cap suction means is connected to the other end of the suction pipe 114A. As shown in FIG. 6A, when any of the recording heads 7A and 7B is located at a position facing the cap 111B mounted on the rack 113, the cap moving cam is received by the driving force from the driving unit 130. When 135 is rotated, as shown in FIG. 6B, the rack 113 moves toward the recording heads 7A and 7B, and finally the edge 111a of the cap 111B is brought into contact with the nozzle surfaces of the recording heads 7A and 7B. Abut to cover. Thereafter, the suction pump 150 is driven to perform a suction operation, whereby the suction force between the cap 111B and the nozzle surfaces of the recording heads 7A and 7B is increased, the sealing inside the cap is enhanced, and the inside of the cap becomes negative pressure. Ink in the recording head is sucked out of the nozzle. The sucked out ink is sent from the suction port of the cap 111B through the suction pipe 114A to the waste liquid tank 151 as a discharged ink container by the suction force of the suction pump 150.

  Here, in the first embodiment, if the decapping is performed as it is after such an ink suction operation, the ink spills out from the cap 111B and the inside of the machine is contaminated. Therefore, in the first embodiment, the ink receiving member 160 is disposed at a position vertically below the opening edge 111a of the cap 111B that contacts the nozzle surfaces of the recording heads 7A and 7B. The ink receiving member 160 is integrally attached to the lower portion of the cap 111B. As shown in FIG. 7, the ink receiving member 160 has a discharge port 160a for discharging the received ink on the inner bottom surface, and the inner wall of the ink receiving member 160 facilitates the flow of the received ink to the discharge port. And an inclined surface inclined downward toward the discharge port. One end of a discharge pipe 114B is connected to the discharge port 160a. A suction pump 150 as an ink receiving suction means is connected to the other end of the discharge pipe 114B. In the first embodiment, the common pipe extending from the suction pump 150 is branched into the suction pipe 114A and the discharge pipe 114B, and the cap suction means for sucking the ink in the cap 111B and the ink in the ink receiving member 160 are used. The suction pump 150 is commonly used as an ink receiving suction means for discharging. By performing the suction operation by driving the suction pump 150, the inside of the discharge pipe 114B becomes negative pressure, the ink inside the ink receiving member 160 is sucked from the discharge port, and passes through the discharge pipe 114B to the waste liquid tank 151. Sent.

  Here, in the first embodiment, since both the suction pipe 114A and the discharge pipe 114B are connected to the suction pump 150, the suction pipe 114A and the discharge pipe are discharged in a situation where one of them does not become a negative pressure state. Ink cannot be sucked from any of the tubes 114B. Therefore, in the first embodiment, a tube crushing portion 161a is provided as a shielding member shared as an ink suction passage shielding means for shielding the suction pipe 114A and a discharge ink passage shielding means for shielding the discharge pipe 114B. Then, by controlling the position of the tube crushing portion 161a, the shielding state and the open state of the suction tube 114A and the discharge tube 114B are switched. As shown in FIG. 6, the tube crushing portion 161 a is integrally held at the lower portion of the slider 161, and moves as the slider 161 moves. The slider 161 moves together with the rack 113 when fixed to the rack 113 by the lock lever 162, and moves separately from the rack 113 when the lock lever 162 is fixed to the rack 113.

8A to 8C are explanatory views when the configuration of the tube crushing portion 161a is viewed from above. In this figure, cross sections of the suction tube 114A and the discharge tube 114B are shown.
When the slider 161 is advanced toward the recording heads 7A and 7B, the tube crushing portion 161a is positioned at the position shown in FIG. At this time, the contact portion 165 of the tube crushing portion 161a moves to the left side in the drawing and presses the side surface of the discharge pipe 114B. The discharge pipe 114B has at least a portion where the contact portion 165 of the tube crushing portion 161a contacts is crushed by applying external pressure to shield the internal passage, and is restored by releasing the external pressure to restore the internal passage. It consists of a flexible tube member that opens. Therefore, when pressed by the contact portion 165 of the tube crushing portion 161a, the discharge pipe 114B is crushed and put into a shielding state as shown in FIG. At this time, since the suction tube 114A is not pressed by the tube crushing portion 161a, the suction tube 114A is in an open state.

  Further, when the slider 161 is retracted in the direction away from the recording heads 7A and 7B and the tube crushing portion 161a is positioned at the position shown in FIG. 8C, the contact portion 165 of the tube crushing portion 161a moves to the right side in the drawing. Then, the side surface of the suction tube 114A is pressed. The suction tube 114A has at least a portion where the contact portion 165 of the tube crushing portion 161a contacts is crushed by applying external pressure to shield the internal passage, and the internal passage is restored by releasing the external pressure. It consists of a flexible tube member that opens. Therefore, by being pressed by the contact portion 165 of the tube crushing portion 161a, the suction tube 114A is crushed and put into a shielding state as shown in FIG. At this time, since the discharge pipe 114B is not pressed by the tube crushing portion 161a, the discharge pipe 114B is in an open state.

  In the first embodiment, the tube crushing portion 161a is positioned at the position shown in FIG. 8B, thereby creating a state where the tube crushing portion 161a does not press either the suction pipe 114A or the discharge pipe 114B. it can. In this case, both the suction pipe 114A and the discharge pipe 114B are opened.

In the first embodiment, when the rack 113 fixed to the slider 161 by the lock lever 162 is in the retracted position, the cap 111B is moved by the biasing force of the cap compression spring 118 as shown in FIG. Is positioned there in a state of sliding to the most advanced position. At this time, the cap 111B enters an uncovered state (decap state) in which the nozzle surfaces of the recording heads 7A and 7B are not covered.
On the other hand, when the rack 113 fixed to the slider 161 by the lock lever 162 is in the forward position, as shown in FIG. 6B, the cap 111B in contact with the nozzle surfaces of the recording heads 7A and 7B is compressed by the cap. It will be in the retracted position where it is pushed into the rack 113 against the biasing force of the spring 118. Thus, when the rack 113 is in the forward position, as shown in FIG. 6B, the opening of the cap 111B is in close contact with the nozzle surface, and the inside of the cap is in a sealed state, so that the nozzle suction process can be performed. Become.

  The idle ejection unit 120 receives and collects the ink ejected from the recording head while facing the recording heads 7A and 7B during non-operation. In the first embodiment, in order to recover and maintain the ejection performance of the recording heads 7A and 7B, the recording heads 7A and 7B are opposed to the idle ejection unit 120 at a predetermined timing, and idle ejection in which ink is idlely ejected from the nozzles. Process. As shown in FIGS. 3 and 4, the idle ejection unit 120 includes an ink receiving member that receives the dripping ink in order to prevent the inside of the apparatus from being contaminated with the ink that droops from the recording head during the idle ejection process. 121 is provided.

FIG. 9 is a perspective view illustrating the driving unit 130 together with the capping unit 110.
The drive unit 130 is for transmitting a driving force necessary for processing in the capping unit 110 and the idle discharge unit 120 to these. The drive unit 130 is attached to the frame unit 112 (not shown in FIG. 9 for illustration) of the capping unit 110. The drive unit 130 includes a stepping motor 131 as a drive source, a gear train 132 for transmitting the drive force generated by the stepping motor 131, and a drive shaft 133 that is rotationally driven by the drive force transmitted by the gear train 132. I have. The stepping motor 131 is configured to be capable of forward / reverse rotation driving, and its rotation direction, rotation position, and rotation angular velocity are controlled by a control unit (not shown). One end side of the drive shaft 133 is inserted into the frame part 112 of the capping part 110.

  On the drive shaft 133, a driven gear 134 that meshes with the gear train 132 coaxially therewith, a cap moving cam 135, and an idle discharge portion moving cam 136 are provided. As shown in FIG. 10, the cap moving cam 135 is disposed at a position opposite to the pin 161b provided on the back surface of the slider 161 of the capping portion 110 (the surface opposite to the surface on which the caps 111A and 111B are provided). Is done. The cap moving cam 135 according to the first embodiment has a structure in which a substantially elliptical cam groove 135c is formed between an outer frame 135a and an inner frame 135b as shown in FIG. 11, and the cam groove 135c has a structure. It is assembled in a state where the pin 161b on the back surface of the slider 161 is inserted. By adopting such a structure, when the drive shaft 133 rotates and the rotation angle of the cap moving cam 135 changes, the pin 161b of the slider 161 moves in the cam groove of the cap moving cam 135, and the slider 161 is displaced in the horizontal direction. Therefore, by controlling the rotation angle of the cap moving cam 135 by the stepping motor 131, the caps 111A and 111B are respectively attached to the recording heads 7A and 7B in a state where the slider 161 and the rack 113 are fixed by the lock lever 162. Can be moved forward in the direction in which they are brought close to each other, or can be brought into a covering state, or the caps 111A, 111B can be moved away from each recording head 7A, 7B in a non-covering state.

  Similarly to the cap moving cam 135, the idle discharge portion moving cam 136 is also for displacing the idle discharge portion 120 in the horizontal direction. The mounting angles of the cap moving cam 135 and the idle discharge unit moving cam 136 with respect to the drive shaft 133 are shifted from each other. Specifically, when the caps 111A and 111B are positioned at the forward position and the recording heads 7A and 7B are in the covering state, the idle discharge unit 120 is positioned at the reverse position, and conversely, the idle discharge unit 120 is at the advance position. When performing the idle discharge processing of the recording heads 7A and 7B, the mounting angles of the cap moving cam 135 and the idle discharge portion moving cam 136 with respect to the drive shaft 133 so that the caps 111A and 111B are positioned in the retracted position. Is set.

  In the first embodiment, the driving force is transmitted to the driving shaft 133 when the stepping motor 131 is rotating forward, and the driving force is not transmitted to the driving shaft 133 when the stepping motor 131 is rotating backward. Has been. Such a configuration can be realized, for example, by interposing a one-way clutch in the gear train 132 of the drive unit 130. On the other hand, when the stepping motor 131 is rotating in reverse, the driving force is transmitted to the suction pump 150. The driving force transmission path to the suction pump 150 is also transmitted to the suction pump 150 when the stepping motor 131 is reversely rotated by using, for example, a one-way clutch, and is suctioned when the stepping motor 131 is forwardly rotated. The driving force is not transmitted to the pump 150. As described above, in the first embodiment, the drive source for driving the capping unit 110 and the idle discharge unit 120 and the drive source for the suction pump are shared, and the number of drive sources is reduced, thereby reducing the cost. However, separate drive sources may be used.

FIG. 12 is a perspective view of the wiping unit 140.
The wiping unit 140 performs a wiping process for removing unnecessary ink adhering to the nozzle surfaces by rubbing (wiping) the nozzle surfaces of the recording heads 7A and 7B with the wiper member 141, and thereby the recording heads 7A and 7B. Recover and maintain discharge performance. In many conventional general wiping processes, the carriage 3 is moved in the main scanning direction, and the nozzle surface of the recording head is rubbed against the stationary wiper member for wiping. However, in the first embodiment, the wiper member 141 is moved to a position facing the wiping unit 140 while the recording heads 7A and 7B are stationary, so that the wiper member rubs the nozzle surface of the recording head and wipes. To do. In the first embodiment, two nozzle rows extending in a direction (vertical direction) orthogonal to the main scanning direction are formed on the nozzle surfaces of the recording heads 7A and 7B. Since the two nozzle rows eject inks of different colors, if the ink of one nozzle row adheres to the other nozzle row, color mixing occurs and an appropriate color cannot be reproduced. In the conventional general wiping method, the recording heads 7A and 7B are moved in the main scanning direction to wipe with a stationary wiper member. Therefore, a wiper to which ink removed by wiping one nozzle row is attached. The other nozzle row is wiped by the member. Therefore, there is a high risk of problems due to color mixing. Therefore, in the first embodiment, the wiper member 141 is moved along the extending direction (vertical direction) of the two nozzle rows while the recording heads 7A and 7B are stationary at the position facing the wiping unit 140. The nozzle surface of the recording head is wiped with a wiper member. As a result, it is possible to avoid a situation where the other nozzle row is wiped at the position of the wiper member that wiped one nozzle row, and it is difficult for color mixing problems to occur.

  In the first embodiment, the wiping unit 140 is configured to be driven by receiving a driving force from a driving source different from the driving unit 130, but is driven to receive the driving force from the driving unit 130. It is also possible to configure. As the wiper member 141, a general wiper member such as a rubber blade can be used. The wiper member 141 is pressed against the nozzle surfaces of the recording heads 7A and 7B to be bent, and moves relative to the nozzle surface while rubbing the nozzle surface. At the end of wiping, the wiper member 141 is separated from the nozzle surface. However, the wiper member 141 in a bent state at the time of separation may be restored and jumped up, and ink removed from the nozzle surface may be scattered. In order to prevent the scattered ink from contaminating the inside of the apparatus, the anti-scattering plates 142 and 143 are arranged above and below the wiper member 141 in the wiping unit 140 of the first embodiment. Note that the anti-scattering plate 142 located below the wiper member 141 also functions to prevent ink removed from the nozzle surface from dripping from the wiper member 141 and contaminating the inside of the apparatus.

FIG. 13 is a flowchart showing a flow of maintenance processing performed using the maintenance unit 100.
14A to 14E are schematic diagrams for explaining the configuration and operation when the suction cap 111B and the slider 161 in the maintenance unit 100 are viewed from the horizontal direction. In FIG. 14, two cap compression springs 118 are illustrated as one spring.
FIGS. 15A to 15C are explanatory views showing the configuration and operation of the lock lever 162 that fixes the rack 113 and the slider 161.

  In the first embodiment, maintenance processing is executed at a predetermined timing such as immediately after the printer is turned on, at the end of the printing operation, or when a maintenance instruction is received from the user. In the maintenance process, first, the control unit of the printer checks whether or not the rotation position (rotation angle) of the stepping motor 131 is the home position (HP) (S1). The home position can be confirmed by, for example, providing a projection on the motor shaft of the stepping motor 131 and arranging a transmission type optical sensor so that the projection passes through a rotating orbit through which the projection passes. The timing when it is detected that is blocked is set as the home position. If the rotation position of the stepping motor 131 is not the home position (HP), the stepping motor 131 is rotated forward until it reaches the home position (S2). In this home position, the caps 111A and 111B of the capping unit 110 are positioned at the retracted position as shown in FIG. 14C, and the idle ejection unit 120 is also positioned at the retracted position.

  After setting the stepping motor 131 to the home position, the control unit controls the main scanning motor 4 to move the carriage 3 to a position where the first recording head 7A faces the suction cap 111B (first head suction position). Move in the main scanning direction (S3). Thereafter, the stepping motor 131 of the maintenance unit 100 is rotated forward to move the slider 161 and the rack 113 horizontally, and the cap 111B is advanced toward the recording head 7A (S4). At this time, as shown in FIG. 15B, the slider 161 and the rack 113 are fixed to each other by the lock lever 162. When the number of pulses (step number) of the stepping motor 131 reaches a predetermined number of pulses, the rotation of the stepping motor 131 is stopped (S5). As a result, as shown in FIG. 6B, the pin 161b on the back surface of the slider 161 is positioned at the long side portion of the cam groove 135c of the cap moving cam 135, and the rack 113 is positioned at the forward movement position. As a result, the opening of the cap 111B is brought into close contact with the nozzle surface of the recording head 7A by the urging force of the cap compression spring 118 so that the nozzle surface is covered. Accordingly, the inside of the cap 111B is in a sealed state, and the nozzle suction process can be performed.

  When the inside of the cap 111B is sealed in this manner, the control unit reverses the stepping motor 131, drives the suction pump 150 to perform a suction operation (S6), and executes an ink suction process. The position of the slider 161 at this time is arranged so that the tube crushing portion 161a is positioned at a position where the suction tube 114A is in an open state and the discharge tube 114B is in a shielded state, as shown in FIG. The Therefore, the inside of the cap 111B can be sucked through the suction pipe 114A by the suction force of the suction pump 150. As a result, ink is sucked out from the nozzles of the first recording head 7A, and the sucked ink is sent from the suction port of the cap 111B to the waste liquid tank 151 through the suction pipe 114A. When the number of pulses (step number) of the stepping motor 131 reaches a predetermined number of pulses, the rotation of the stepping motor 131 is stopped (S7).

  After waiting for a predetermined time to elapse after the ink suction process (S8), the control unit causes the stepping motor 131 to rotate forward to retract the rack 113 (S9). When the number of pulses (step number) of the stepping motor 131 reaches a predetermined number of pulses, the rotation of the stepping motor 131 is stopped (S10). Even at this time, as shown in FIG. 15A, the slider 161 and the rack 113 are fixed to each other by the lock lever 162. Therefore, as shown in FIG. 156 (a), the pin 161b on the back surface of the slider 161 is located at the intermediate portion between the long side and the short side of the cam groove 135c of the cap moving cam 135, and the rack 113 is shown in FIG. It is positioned in the retracted position and enters a decap state.

  Here, before the decap after the ink suction process, as shown in FIG. 14B, a part of the ink sucked from the nozzle remains inside the cap 111B. In the first embodiment, since the cap 111B is capped from the horizontal direction with respect to the nozzle surface parallel to the vertical surface, the cap 111B is separated from the nozzle surface when the ink is left in the cap 111B. When this is done, the ink in the cap flows out from the opening of the cap. The ink that has flowed out in this way flows down onto the ink receiving member 160 and is accommodated therein as shown in FIG. 14C. Therefore, the inside of the machine is not contaminated by the ink flowing out from the cap.

  After decaping in this manner, the control unit waits for a predetermined time to elapse (S11), and then reverses the stepping motor 131 and drives the suction pump 150 to perform the suction operation for a predetermined period (S12). At this time, as shown in FIG. 14D, the tube crushing portion 161a of the slider 161 is positioned at a position where the suction tube 114A is opened and the discharge tube 114B is shielded. Therefore, the ink remaining in the suction pipe 114 </ b> A can be sucked by the suction force of the suction pump 150 and sent to the waste liquid tank 151.

  Thereafter, when the number of pulses (step number) of the stepping motor 131 reaches the predetermined number of pulses, the rotation of the stepping motor 131 is stopped, and the control unit causes the stepping motor 131 to rotate forward to further retract the slider 161 (S13). When the number of pulses (step number) of the stepping motor 131 reaches a predetermined number of pulses, the rotation of the stepping motor 131 is stopped. As a result, the pin 161b on the back surface of the slider 161 is positioned in the short side portion of the cam groove 135c of the cap moving cam 135. Here, in the first embodiment, while the rack 113 is located at the decap position, only the slider 161 is further retracted from the decap position shown in FIG. 15B to the suction tube shielding position shown in FIG. 15C. Will move.

  More specifically, in the first embodiment, a lock release protrusion 163 for releasing the lock state of the lock lever 162 is provided on the printer main body side. Therefore, when the slider 161 is further retracted, the end of the lock lever 162 provided on the slider 161 collides with the unlocking protrusion 163 and the lock lever 162 is rotated, as shown in FIG. The locked state between the rack 113 and the slider 161 is released. As a result, only the slider 161 is further retracted while the rack 113 is in the decap position.

  As described above, when only the slider 161 is further retracted while the rack 113 is positioned at the decap position, the tube crushing portion 161a provided on the slider 161 is moved together therewith. At this time, since the suction tube 114A and the discharge tube 114B are fixed to the rack 113, the tube crushing portion 161a moves relative to the suction tube 114A and the discharge tube 114B. As a result, as shown in FIG. 14E, the suction pipe 114A is in a shielding state and the discharge pipe 114B is in an open state. Then, the control unit reverses the stepping motor 131 and drives the suction pump 150 to execute the suction operation for a predetermined period (S14). At this time, the tube crushing portion 161a of the slider 161 is positioned at a position where the suction tube 114A is in a shielding state and the discharge tube 114B is in an open state, as shown in FIG. 14 (e). Therefore, the ink stored in the ink receiving member 160 can be sucked through the discharge pipe 114B by the suction force of the suction pump 150. The ink sucked in this way is sent from the discharge port of the ink receiving member 160 to the waste liquid tank 151 through the discharge pipe 114B.

  Subsequently, the control unit controls the main scanning motor 4 to move the carriage 3 in the main scanning direction to a position where the first recording head 7A faces the wiping unit 140 (first head wiping position) (S16). . Thereafter, the wiping unit 140 is driven and controlled to move the wiper member 141 up and down to wipe the nozzle surface of the first recording head 7A (S17), and unnecessary ink on the nozzle surface is removed.

  When the maintenance process for the first recording head 7A is completed in this way, the process proceeds to the maintenance process for the second recording head 7B. First, the control unit determines that the rotation position (rotation angle) of the stepping motor 131 is the home position. It is confirmed whether it is (HP) (S18). If the rotation position of the stepping motor 131 is not the home position (HP), the stepping motor 131 is rotated forward until it reaches the home position (S19). After setting the stepping motor 131 to the home position, the control unit controls the main scanning motor 4 to move the carriage 3 to a position where the second recording head 7B faces the suction cap 111B (second head suction position). Move in the main scanning direction (S20). Thereafter, the stepping motor 131 of the maintenance unit 100 is rotated forward to move the rack 113 horizontally, and the cap 111B is moved forward toward the recording head 7B (S21). When the number of pulses (step number) of the stepping motor 131 reaches a predetermined number of pulses, the rotation of the stepping motor 131 is stopped (S22). As a result, the rack 113 is positioned at the forward position, and the cap 111B is in a sealed state shown in FIG.

  When the inside of the cap 111B is sealed in this manner, the control unit reverses the stepping motor 131, drives the suction pump 150 to perform a suction operation (S23), and executes an ink suction process. Thus, ink is sucked out from the nozzles of the second recording head 7B by the suction force of the suction pump 150, and the sucked ink is sent from the suction port of the cap 111B to the waste liquid tank 151 through the suction pipe 114A. When the number of pulses (step number) of the stepping motor 131 reaches the predetermined number of pulses, the rotation of the stepping motor 131 is stopped (S24). Thereafter, the control unit waits for a predetermined time to elapse (S25), and then causes the stepping motor 131 to rotate forward to retract the rack 113 (S26). When the number of pulses (step number) of the stepping motor 131 reaches the predetermined number of pulses, the rotation of the stepping motor 131 is stopped (S27). As a result, the rack 113 and the slider 161 are positioned at the decap position as shown in FIG. As a result, the ink remaining by the ink suction process flows out from the opening of the cap 111B, and the ink flows down onto the ink receiving member 160 and is accommodated therein as shown in FIG. 14C. Thereafter, after waiting for a predetermined time to elapse (S28), the control unit reverses the stepping motor 131 and drives the suction pump 150 to perform the suction operation for a predetermined period (S29). At this time, as shown in FIG. 14D, the tube crushing portion 161a of the slider 161 is positioned at a position where the suction tube 114A is opened and the discharge tube 114B is shielded. Therefore, the ink remaining in the suction pipe 114 </ b> A can be sucked by the suction force of the suction pump 150 and sent to the waste liquid tank 151. When the number of pulses (step number) of the stepping motor 131 reaches a predetermined number of pulses, the rotation of the stepping motor 131 is stopped.

  When the ink in the suction tube 114A is removed in this way, the control unit causes the stepping motor 131 to rotate forward to further retract the rack 113 (S30), and the number of pulses (step number) of the stepping motor 131 is the predetermined number of pulses. Is reached, the rotation of the stepping motor 131 is stopped. During this movement, the locked state of the lock lever 162 is released by the unlocking projection 163, so that only the slider 161 is further retracted while the rack 113 remains in the decap position, and the decap position shown in FIG. To the suction tube shielding position shown in FIG. Thereby, the tube crushing part 161a provided in the slider 161 moves, and as shown in FIG.14 (e), the suction pipe 114A will be in a shielding state, and the discharge pipe 114B will be in an open state. Then, the control unit reverses the stepping motor 131 and drives the suction pump 150 to execute the suction operation for a predetermined period (S31). Thus, the ink accumulated in the ink receiving member 160 is sucked through the discharge pipe 114B by the suction force of the suction pump 150 and sent to the waste liquid tank 151.

  Then, the control unit controls the main scanning motor 4 to move the carriage 3 in the main scanning direction to a position where the second recording head 7B faces the wiping unit 140 (second head wiping position) (S33). Then, the wiping unit 140 is driven and controlled to move the wiper member 141 up and down to wipe the nozzle surface of the second recording head 7B (S34), and unnecessary ink on the nozzle surface is removed.

  When the maintenance process for the two recording heads 7A and 7B is completed in this way, the control unit confirms whether or not the rotation position (rotation angle) of the stepping motor 131 is the home position (HP) (S35). If the rotation position of the stepping motor 131 is not the home position (HP), the stepping motor 131 is rotated forward until it reaches the home position (S36). Then, the control unit controls the main scanning motor 4 to move the carriage 3 in the main scanning direction to a position where the second recording head 7B faces the suction cap 111B (S37). The maintenance unit 100 according to the first embodiment is configured such that when the second recording head 7B is opposed to the suction cap 111B, the first recording head 7B is opposed to the capping cap 111A. In the first embodiment, the position where the two recording heads 7A and 7B face the caps 111A and 111B is the home position of the carriage 3.

  After the carriage 3 is positioned at the home position, the control unit rotates the stepping motor 131 to move the rack 113 horizontally, and moves the caps 111A and 111B forward toward the recording heads 7A and 7B (S38). When the number of pulses (step number) of the stepping motor 131 reaches a predetermined number of pulses, the rotation of the stepping motor 131 is stopped (S39). As a result, the rack 113 is positioned at the forward position, the nozzle surfaces of the recording heads 7A and 7B are capped by the caps 111A and 111B, and the nozzle surfaces are moisturized.

As described above, in the first embodiment, since the nozzle surfaces of the recording heads 7A and 7B are parallel to the vertical surface during the ink suction processing, the opening surface of the cap 111B that caps the nozzle surfaces is also a vertical surface, and the ink suction processing is performed. If the decapping is performed as it is, the ink remaining in the cap 111B spills out from the opening surface. However, according to the first embodiment, the ink spilled from the opening surface of the cap 111B is stored in the ink receiving member 160, and finally is discharged from the discharge port provided in the ink receiving member 160 through the discharge pipe 114B. Thus, the waste liquid tank 151 is recovered. Therefore, the ink received by the ink receiving member 160 does not solidify on the ink receiving member as it is, and the ink that drips down to the ink receiving member 160 overflows from the ink receiving member 160. Hard to do. As a result, it is possible to continue to receive ink dripping from the cap 111B, and it is possible to prevent in-machine contamination due to ink for a long period of time.
In the first embodiment, as shown in FIGS. 14C to 14E and FIGS. 15B and 15C, the ink receiving member 160 is located below the nozzle surfaces of the recording heads 7A and 7B even in the decap state. It is configured to extend to the area. Immediately after decapping after the ink suction process, ink is also deposited on the nozzle surfaces of the recording heads 7A and 7B, which moves downward along the nozzle surfaces and may fall from the lower end of the nozzle surfaces. According to the first embodiment, the ink falling from the lower end of the nozzle surface can be collected by the ink receiving member 160 as described above, so that the contamination inside the apparatus by such ink can be prevented.

  In the first embodiment, after the decap after the ink suction process, the ink in the suction tube 114A communicating with the cap 111B is removed and then the ink on the ink receiving member 160 is removed. Yes. However, the first embodiment is configured such that both the suction tube 114A and the discharge tube 114B can be opened by positioning the tube crushing portion 161a at the position shown in FIG. 7B. . Therefore, after the decap after the ink suction process, both the suction pipe 114A and the discharge pipe 114B are opened, and the suction pump is driven to simultaneously remove the ink in the suction pipe 114A and the ink on the ink receiving member 160. It is possible.

  In the first embodiment, a configuration in which both the suction tube 114A and the discharge tube 114B can be in a shielded state may be employed. In this case, the suction tube 114A and the discharge tube 114B are shielded during a period in which ink does not flow through the suction tube 114A and the discharge tube 114B (during image forming operation, idle discharge processing, wiping processing, etc.). It is possible to avoid problems such as the inside of the pipe 114A and the discharge pipe 114B being exposed to the atmosphere, the remaining ink being dried, and the ink being fixed inside the suction pipe 114A and the discharge pipe 114B. In the first embodiment, when both the suction tube 114A and the discharge tube 114B are in the shielding state, for example, the tube crushing portion 161a is horizontally moved in a direction orthogonal to the arrangement direction of the suction tube 114A and the discharge tube 114B. Configuration is conceivable.

[Modification 1]
Next, a modified example of the ink receiving member 160 in the first embodiment (hereinafter, this modified example is referred to as “modified example 1”) will be described.
16A to 16C are explanatory views showing the configuration of the ink receiving member 260 in the first modification.
In the first modification, as in the first embodiment, the ink receiving member 160 is also disposed at a position vertically below the opening edge 111a of the cap 111B that contacts the nozzle surfaces of the recording heads 7A and 7B. And is attached integrally to the lower part of the cap 111B. However, two discharge ports 260a and 260b for discharging the received ink are provided on the inner bottom surface of the ink receiving member 260 in the first modification. As shown in FIGS. 16B and 16C, each of the outlets 260a and 260b is directly below the position where each nozzle row is located on the nozzle surface of the recording heads 7A and 7B in the covered state. It is comprised so that a discharge port may be located.

Most of the ink that falls along the nozzle surfaces of the recording heads 7A and 7B is ink that falls along the nozzle rows. Therefore, according to the first modification, ink that falls down on each nozzle row during decap can directly enter the discharge ports 260a and 260b. Therefore, the ink received by the ink receiving member 260 can be efficiently discharged from the discharge ports 260a and 260b.
Moreover, in the first modification, as in the first embodiment, as shown in FIG. 16 (c), the discharge ports 260a and 260b are provided at positions below the opening edge portion 111a of the cap 111B in the vertical direction as shown in FIG. To position. The ink that flows out from the cap 111B at the time of decapping usually drops from the lower end of the opening edge 111a of the cap 111B. Therefore, according to the first modification, as in the first embodiment, the ink flowing out from the cap 111B during the decap can be directly received in the vicinity of the discharge ports 260a and 260b. Therefore, the ink received by the ink receiving member 260 can be efficiently discharged from the discharge ports 260a and 260b.

FIGS. 17A and 17B are explanatory views of an ink receiving member 260 ′ showing another example in the first modification.
In this example, since each of the discharge ports 260a and 260b is disposed at a position off from the position directly below each nozzle row, the ink that falls down on each nozzle row at the time of decap is efficiently discharged from the discharge ports 260a and 260b. Therefore, the configuration is inferior to that of the first modification. However, since the bottom surface shape of the ink receiving member 260 ′ in this example is a mountain-shaped cross section, it is easier to process than the ink receiving member 260 in Modification 1 in which the bottom surface shape is a W-shaped cross section. It is advantageous.
In this example as well, since each discharge port 260a, 260b is positioned at a position below the opening edge 111a of the cap 111B in the vertical direction in the covered state, the ink flowing out from the cap 111B at the time of decap is efficiently discharged. , 260b.

[Modification 2]
Next, a modified example of the maintenance unit 100 in the first embodiment (hereinafter, this modified example is referred to as “modified example 2”) will be described.
FIG. 18 is an explanatory view showing the suction means of the maintenance unit 100 in the second modification.
In the first embodiment, the suction pump that sucks the suction pipe 114A connected to the cap 111B and the suction pump that sucks the discharge pipe 114B connected to the ink receiving member 160 are the common suction pump 150. However, in the second modification, these are separate suction pumps 350A and 350B. As described above, the suction pipe 114A and the discharge pipe 114B are sucked by the suction pumps 350A and 350B independent from each other, so that the suction pipe 114A and the discharge pipe 114B can be sucked without switching between the shielded state and the open state. The pipe 114A and the discharge pipe 114B can be sucked at arbitrary timings, respectively. Therefore, according to the second modification, it is not necessary to provide a configuration for switching between the shielding state and the open state of the suction pipe 114A and the discharge pipe 114B. In addition, since the suction tube 114A and the discharge tube 114B can be sucked independently, the suction operation can be executed without being affected by the situation of the other tube, and the degree of freedom of the suction operation is increased.

[Modification 3]
Next, a modified example of the cap 111B in the first embodiment (hereinafter, this modified example is referred to as “modified example 3”) will be described.
FIGS. 19A to 19C are schematic diagrams for explaining the configuration and operation when the suction cap 411B in the maintenance unit 100 is viewed from the horizontal direction.
In the third modification, before the decap after the ink suction process, the inside of the cap is opened to the atmosphere, and the ink remaining in the cap is removed from the suction port, and then the decap is performed. As a configuration for that purpose, the cap 411B of Modification 3 is provided with an air opening hole 411b which is a communication hole for communicating the inside and outside of the cap on the back surface of the cap 411B. However, since the inside of the cap needs to be sealed in order to perform the nozzle suction process, the air opening hole 411b must be closed. Therefore, in the third modification, an air release valve 416 is provided as a lid member that closes the air release hole 411b. The atmosphere release valve 416 is attached to a position facing the atmosphere release hole 411b on the inner wall of the rack 413 in a state in which the atmosphere release valve 416 can slide in the horizontal direction (left and right direction in FIG. 19) with respect to the rack 413. The sliding movement range is limited by a guide groove (not shown) provided in the rack 413. The air release valve 416 is urged from the rack 413 to the left side in FIG. 19 (at the air release hole 411b side) by a compression spring 417.

  In the third modification, after the ink suction process, the control unit causes the stepping motor 131 to rotate forward to move the rack 113 backward. At this time, the cap 411B is stopped at the atmospheric release position before the decap position. The cap 411B is in contact with the nozzle surfaces of the recording heads 7A and 7B by the urging force of the cap compression spring 418 when positioned at the atmosphere release position, but the atmosphere release valve 416 is an atmosphere provided on the back surface of the cap. It will be in the state spaced apart from the open hole 411b. As a result, the atmosphere opening hole 411b is opened, and the inside of the cap 411B is opened to the atmosphere through the atmosphere opening hole 411b with the opening being closed by the nozzle surface. In this state, ink does not flow out from the opening of the cap 411B. Moreover, the air opening hole 411b is provided in the upper part of the cap, which is higher than the liquid level of the ink remaining in the cap. Therefore, even if the atmosphere opening hole 411b is opened, ink does not leak from the atmosphere opening hole 411b.

  When the cap 411B is opened to the atmosphere in this way, the control unit waits for a predetermined time to elapse, and then reverses the stepping motor 131 to drive the suction pump 150 to execute the suction operation. At this time, since the inside of the cap is open to the atmosphere through the open air hole 411b, even if the inside of the cap is sucked by the suction pump 150, the ink is not sucked out from the nozzles of the recording heads 7A and 7B. The ink inside can be collected from the suction port to the waste liquid tank 151 through the suction pipe 114A. When the number of pulses (step number) of the stepping motor 131 reaches a predetermined number of pulses, the rotation of the stepping motor 131 is stopped. When the ink in the cap 411B is removed in this way, the control unit causes the stepping motor 131 to rotate forward to further retract the rack 413. Thereby, cap 411B will be in a decap state. Subsequent control may be the same as in the case of the eleventh embodiment.

  According to the third modification, since the ink does not flow out from the cap 411B during the decap after the ink suction process, the amount of ink that should be received by the ink receiving member 460 can be reduced. Therefore, the size of the ink receiving member 460 can be reduced, and space saving can be achieved.

[Embodiment 2]
Next, another embodiment of the present invention (hereinafter, this embodiment is referred to as “embodiment 2”) will be described with reference to the accompanying drawings, taking as an example a serial printer that is an ink jet recording apparatus as an image forming apparatus. explain.
Since the printer of the second embodiment is the same as that of the first embodiment except for the configuration of the maintenance unit, the description of the common points with the first embodiment is omitted in the following description.

20A to 20C are explanatory views schematically showing the configuration and operation of the capping unit 510 from the end of the nozzle suction process to the start of the wiping process.
The capping unit 510 according to the second embodiment has two caps 511A and 511B as in the first embodiment, and one of them is used as a suction cap 511B. However, the cap 511B of the second embodiment has an ink receiving portion 560 that functions as an ink receiving member whose lower portion protrudes to the lower side of the recording heads 7A and 7B, and a vertical section thereof is as shown in FIG. It is formed in a substantially L shape. By providing the ink receiving portion 560, as with the ink receiving member of the first embodiment, even if the ink remaining in the cap 511B flows out during the decap after the ink suction process, the recording heads 7A and 7B Even if ink drops on the nozzle surface, the ink is accommodated in the ink receiving portion 560, and contamination inside the apparatus is prevented.

  The ink storage chamber formed inside the ink receiving portion 560 communicates with the inside of the main body of the L-shaped cap 511B. As shown in FIG. 20A, the L-shaped cap 511B is connected to the recording heads 7A and 7B. Is brought into contact with the outer walls of the lower surfaces of the recording heads 7A and 7B to be in a sealed state. Therefore, when the rack 513 is moved toward the recording heads 7A and 7B by the driving unit 530 and the edge of the L-shaped cap 511B comes into contact with the nozzle surfaces of the recording heads 7A and 7B to be in the covering state, the L-shaped cap The inside of the main body of 511B and the ink receiving chamber of the ink receiving portion 560 communicating with the main body are sealed, and suction is performed by the suction pump 150, so that the inside of the cap becomes negative pressure and ink in the recording head is sucked out from the nozzles. . The sucked ink is sent to the waste liquid tank 151 through the suction pipe 514 from the suction port formed at the bottom of the ink receiving portion 560 of the L-shaped cap 511B by the suction force of the suction pump 150.

  In the second embodiment, the ink remaining in the main body of the cap 511B during the ink suction process and the ink received by the ink receiver 560 during the decap pass through the suction pipe 514 from the suction port provided in the ink receiver 560. It is sent to the waste liquid tank 151. Therefore, a mechanism for switching the suction target of the suction pump 150, such as the tube crushing portion 161a and the slider 161 in the first embodiment, is unnecessary.

  After the ink suction process, the ink remains in the L-shaped cap 511B. However, the ink is subjected to the action of gravity, and the ink is stored in the ink receiving portion 560 formed in the lower portion of the L-shaped cap 511B. Fits indoors. Therefore, as shown in FIG. 20B, even when the ink is decapped while the ink remains in the L-shaped cap 511B, the ink does not spill out of the L-shaped cap 511B. Since the inside of the L-shaped cap 511B is opened to the atmosphere by decapping in this way, if suction is performed by driving the suction pump 150 in this state, the ink receiving chamber 560 has an ink containing chamber. The remaining ink can be discharged to the waste liquid tank 151 through the suction pipe 514 from the suction port formed at the bottom of the ink receiving portion 560.

  In the second embodiment, after the nozzle suction process is performed, the decapping is performed and the uncovered state shown in FIG. In the second embodiment, the wiper member 540 is fixed at an upper position of the cap 511B. For this reason, the wiper member 540 moves integrally with the movement of the cap 511B, and can perform a wiping process by rubbing the nozzle surfaces of the recording heads 7A and 7B. Thus, in the second embodiment, the capping unit 510 performs a wiping process in which the nozzle surface after the nozzle suction process is wiped by the wiper member 540, and the wiping unit 140 provided in the first embodiment is used as the capping unit. Need not be provided separately.

  In the second embodiment, when the rack 513 is moved from the forward position (covered position) to the retracted position (non-covered position) shown in FIG. 20A by the drive unit 530, the upper portion of the L-shaped cap 511B is used. The wiper member 540 attached to the wiping member is configured to be located at the wiping movement start position. Therefore, in the second embodiment, after the rack 513 is moved to the retracted position (non-covering position), the wiper member 540 is moved as it is, so that the nozzle surfaces of the recording heads 7A and 7B are moved by the wiper member 540. A wiping process for removing unnecessary ink adhering to the nozzle surface by rubbing (wiping) can be performed.

  The drive unit 530 in the second embodiment is configured such that a drive source for driving the suction pump and a drive source for driving the rack 513 are provided separately, and can be controlled independently of each other. A drive source for driving the rack 513 is composed of a stepping motor 531, and a drive gear 532 is connected to the motor shaft. The drive gear 532 meshes with a driven tooth row 533 having a large number of teeth arranged in the vertical direction on the back surface of the rack 513. As a result, the rack 513 moves up and down following the rotation of the drive gear 532 driven by the stepping motor 531. In the second embodiment, the rack 513 can be moved upward by rotating the stepping motor 531 in the forward direction, and the rack 513 can be moved downward by rotating the stepping motor 531 in the reverse direction.

  Here, in the second embodiment, the movement path of the rack 513 is regulated so that the rack 513 moves on the movement path where both the decapping operation and the wiping operation are realized only by reversing the stepping motor 531. A guide rail 534 is provided for guiding. A guided portion 513 a integrally formed with the rack 513 is fitted into the guide rail 534, and when the rack 513 is moved up and down by driving the stepping motor 531, the rack 513 is regulated by the guide rail 534. Will move.

FIG. 21 is a flowchart showing an outline of the flow of maintenance processing performed before printing. In this flowchart, the flow of the main part of the maintenance process is extracted and described.
FIG. 22 shows the position of the guided portion 513a on the guide rail 534 when the rack 513 is located at each of the forward movement position (covering position), the backward movement position (non-covering position = wiping operation start position), and the wiping operation end position. It is explanatory drawing which shows I, II, and III.
When image formation is performed after being left for a long time, there is a high possibility of nozzle missing, and maintenance processing may be performed before printing. As a procedure in this case, first, based on the rotation position (rotation angle) of the stepping motor 531, the printer control unit confirms that the rack 513 is positioned at the forward movement position (covering position) and the cap 511B is in the covering state. Confirm (S41). At this time, the guided portion 513a on the guide rail 534 is located at the capping position I shown in FIG. As for the rotation position (rotation angle) of the stepping motor 531, for example, a projection is provided on the motor shaft of the stepping motor 531, and a transmissive optical sensor is disposed so as to pass through the rotation path through which the projection passes. The timing at which the sensor detects that the optical path is blocked by the protrusion can be grasped.

  Thereafter, the control unit drives the suction pump 150 (S42), and performs an ink suction process for sucking ink from the nozzles of the recording heads 7A and 7B by setting the inside of the L-shaped cap 511B to a negative pressure. Then, the control unit stops the driving of the suction pump 150 in accordance with the end timing of the ink suction process (S43). When the ink suction process is thus completed, the stepping motor 531 is driven in reverse (S44), and the rack 513 is lowered. As a result, the guided portion 513a on the guide rail 534 moves from the capping position I shown in FIG. 22 to the decap position II. As a result, the rack 513 is positioned at the retracted position (non-covering position = wiping operation start position) as shown in FIG. 20B, the cap 511B is in the decap state, and the wiper member 540 is at the wiping operation start point. Positioned.

  Thereafter, when the stepping motor 531 continues to be driven in reverse and the rack 513 is lowered, the guided portion 513a on the guide rail 534 moves from the decap position II shown in FIG. 22 to the wiping end position III. During this movement, as shown in FIG. 20 (c), the rack 513 moves in parallel along the nozzle surfaces of the recording heads 7A and 7B, so that the wiper member 540 moves the nozzle surfaces of the recording heads 7A and 7B to the upper end side. The wiping process is performed by rubbing toward the lower end side. When the guided portion 513a moves to the lower end of the guide rail 534, that is, the wiping end position III shown in FIG. 22, the wiper member 540 moves below the lower end of the nozzle surface of the recording heads 7A and 7B. Accordingly, the wiping process is performed by the wiper member 540 over the entire area from the upper end to the lower end of the nozzle surfaces of the recording heads 7A and 7B.

  In the wiping process, when the wiper member 540 passes through the lower end of the nozzle surface of the recording heads 7A and 7B, the wiper member 540 that has been bent due to contact with the nozzle surface is restored, and the tip of the wiper member 540 jumps up. At this time, the ink adhering to the tip of the wiper member 540 flies downward in the vertical direction. In the second embodiment, since the ink receiving portion 560 is located at the destination of the ink flying, the ink flying when the wiper member 540 passes through the lower end of the nozzle surface of the recording heads 7A and 7B is the ink receiving portion. 560 is received in the ink storage chamber in 560. Therefore, the interior of the machine is not contaminated by the flying ink.

  As described above, after the wiping process is completed, the control unit performs the control of the maintenance unit 100 and the control of the recording heads 7A and 7B in parallel. In the control of the maintenance unit 100, first, the suction pump 150 is driven (S45), and the ink remaining in the ink storage chamber in the ink receiving portion 560 of the L-shaped cap 511B is passed through the suction pipe 514 to the waste liquid tank. Collect to 151. Then, the control unit stops the driving of the suction pump 150 in accordance with the end timing of the residual ink collection process (S46). Thereafter, the control unit drives the stepping motor 531 to rotate forward (S47) and raises the rack 513. As a result, the guided portion 513a on the guide rail 534 moves from the wiping end position III shown in FIG. 22 to the decap position II and stands by at that position.

  On the other hand, in the control of the recording heads 7A and 7B performed in parallel with the control of the above-described maintenance unit 100, the main scanning motor 4 is controlled to move the recording heads 7A and 7B to the position facing the idle ejection unit 120. Is moved in the main scanning direction (S48). Then, the control unit drives and controls the recording heads 7A and 7B to perform the idle ejection process for ejecting ink from the nozzles into the idle ejection unit 120 (S49).

FIG. 23 is a flowchart showing an overview of the flow of maintenance processing performed during continuous printing. In this flowchart, the flow of the main part of the maintenance process is extracted and described.
When the negative pressure of the head tank becomes too strong during continuous printing and the ink discharge load from the nozzles becomes large, maintenance processing may be performed during continuous printing. As a procedure in this case, first, based on the rotation position (rotation angle) of the stepping motor 531, the control unit of the printer has the rack 513 in the retracted position (uncovered position) and the cap 511B is in the uncovered state. This is confirmed (S51). That is, it is confirmed that the guided portion 513a on the guide rail 534 is located at the decap position II shown in FIG. Thereafter, the control unit controls the main scanning motor 4 to move the carriage 3 in the main scanning direction to a position where the recording heads 7A and 7B face the L-shaped cap 511B of the capping unit 110 (S52). When the controller drives the stepping motor 531 to rotate forward (S53) and raises the rack 513, the guided portion 513a on the guide rail 534 is moved from the decap position II shown in FIG. 22 to the capping position I. Move to. As a result, the rack 513 is positioned at the forward movement position (covering position), and the recording heads 7A and 7B are covered by the cap 511B.

  Thereafter, the control unit drives the suction pump 150 (S42), and performs an ink suction process for sucking ink from the nozzles of the recording heads 7A and 7B with a negative pressure inside the L-shaped cap 511B. Since this is the same as S42 to S49 in the flowchart shown in FIG.

FIG. 24 is a flowchart showing an outline of the flow of maintenance processing performed after printing. In this flowchart, the flow of the main part of the maintenance process is extracted and described.
After printing, capping is performed to stop the machine in order to prevent moisture from entering impurities such as dust and to prevent nozzle clogging due to ink sticking. As a procedure in this case, first, based on the rotation position (rotation angle) of the stepping motor 531, the control unit of the printer has the rack 513 in the retracted position (uncovered position) and the cap 511B is in the uncovered state. This is confirmed (S61). That is, it is confirmed that the guided portion 513a on the guide rail 534 is located at the decap position II shown in FIG. Thereafter, the control unit controls the main scanning motor 4 to move the carriage 3 in the main scanning direction to a position where each of the recording heads 7A and 7B opposes each of the caps 511A and 511B of the capping unit 110 (S62). ). When the controller drives the stepping motor 531 to rotate forward (S63) and raises the rack 513, the guided portion 513a on the guide rail 534 moves from the decap position II shown in FIG. 22 to the capping position I. Move to. As a result, the rack 513 is positioned at the forward position (covering position), and the recording heads 7A and 7B are respectively covered by the two caps 511A and 511B.

  According to the second embodiment, since the wiper member 540 is mounted on the L-shaped cap 511B, it is not necessary to secure a position for disposing the wiper member separately from the cap member in the main scanning direction. As a result, the space of the apparatus can be saved and the number of parts can be reduced. Moreover, according to the second embodiment, it is not necessary to move the carriage 3 in the main scanning direction after the decap, and it is not necessary to move the wiper member to the wiping operation start position, and the wiping operation is performed immediately after the decap. Can be implemented. Therefore, the processing time of the entire maintenance process can be shortened.

[Modification 4]
Next, a modified example of the L-shaped cap 511B in the second embodiment (hereinafter, this modified example is referred to as “modified example 4”) will be described.
FIGS. 25A and 25B are explanatory views showing a schematic configuration of an L-shaped cap 611B in the fourth modification.
In the L-shaped cap 611B in the fourth modification, an opening 611a facing the nozzle surfaces of the recording heads 7A and 7B and an edge 611a of the opening of the ink receiving portion 660 facing the lower surfaces of the recording heads 7A and 7B have a bellows shape. In this respect, it differs from that of the second embodiment. As a material of the bellows-like edge portion 611a, for example, soft silicon rubber can be used. In the fourth modification, when the L-shaped cap 611B is in contact with the nozzle surfaces of the recording heads 7A and 7B and positioned at the covering position, the bellows-like edge 611a is compressed as shown in FIG. Thus, the opening of the L-shaped cap 611B is closed with high sealing performance by the nozzle surfaces of the recording heads 7A and 7B. On the other hand, when the L-shaped cap 611B is separated from the nozzle surfaces of the recording heads 7A and 7B and is located at the uncovered position, the compressed bellows-like edge 611a is restored as shown in FIG. It becomes a state. As a result, the volume of the L-shaped cap 611B in the main body and the volume of the ink receiving portion 660 in the ink storage chamber are both larger than in the covered state.

  With the configuration as described above, according to the fourth modification, when the nozzle surfaces of the recording heads 7A and 7B are in the covered state, the sealed space in the L-shaped cap 611B is narrowed. The ink can be efficiently sucked out of the nozzle by the force. When the nozzle surfaces of the recording heads 7A and 7B are in an uncovered state, the volume of the ink storage chamber in the ink receiving portion 660 of the L-shaped cap 611B is increased, so that it remains in the L-shaped cap 611B. Ink does not spill easily.

[Modification 5]
Next, another modified example of the L-shaped cap 511B in the second embodiment (hereinafter, this modified example is referred to as “modified example 5”) will be described.
FIG. 26 is an explanatory diagram showing a schematic configuration of an L-shaped cap 711B in the fifth modification.
The L-shaped cap 711 </ b> B in Modification 5 is provided with an L-shaped absorber 719 capable of absorbing and holding ink in the space inside the main body and the ink storage chamber of the ink receiving portion 760. It differs from that of the second embodiment. In this absorber 719, as shown in FIG. 26, the vertical portion facing the nozzle surface of the recording heads 7A and 7B does not protrude outward (nozzle surface side) from the opening edge of the main body of the L-shaped cap 711B. It is configured as follows. As a result, even when the L-shaped cap 711B is in contact with the nozzle surfaces of the recording heads 7A and 7B and positioned at the covering position, the vertical portion of the absorber 719 is not in contact with the nozzle surface, and the absorber 719 is not in contact with the ink. It does not interfere with the suction process. On the other hand, the horizontal portion of the absorber 719 disposed in the ink containing chamber of the ink receiving portion 760 is configured to be positioned higher than the ink containing chamber. The horizontal absorber portion is made of a soft and highly elastic material, and is compressed and deformed when the L-shaped cap 711B is in contact with the nozzle surfaces of the recording heads 7A and 7B and positioned at the covering position. The sealing performance by the opening edge of the L-shaped cap 711B is not disturbed. The absorbent body 719 may be formed as a whole or may be configured by combining a plurality of members.

  With the configuration as described above, according to the fifth modification, the ink is absorbed while the horizontal portion of the absorber 719 swells during the decap after the ink suction process. Furthermore, the horizontal portion of the absorber 719 also absorbs ink that hangs down from the nozzle surface and collects at the lower ends of the recording heads 7A and 7B. Therefore, according to the fifth modification, not only the effect of preventing ink from spilling out of the L-shaped cap 711B but also the lower part of the recording heads 7A and 7B can be cleaned by the absorber 719. It is possible to prevent the occurrence of problems such as ink sticking to the lower portion of 7B and the sticking ink rubbing against the paper and soiling the paper.

[Modification 6]
Next, still another modified example of the L-shaped cap 511B in the second embodiment (hereinafter, this modified example is referred to as “modified example 6”) will be described.
FIG. 27 (a) is a top view of the L-shaped cap 811B in the sixth modification, FIG. 27 (b) is a side view of the L-shaped cap 811B, and FIG. FIG. 6 is a perspective view illustrating an L-shaped cap 811B together with recording heads 7A and 7B.
In the L-shaped cap 811B in the sixth modification, the width W1 of the contact end portion of the wiper member that contacts the nozzle surfaces of the recording heads 7A and 7B is wider than the width W2 of the nozzle surface, and the ink in the ink receiving portion. It is comprised so that it may become narrower than the width W3 of a storage chamber. In order to realize such a configuration, in the sixth modification, the width W1 of the contact end portion where the wiper member 840 contacts the nozzle surface is wider than the width of the end portion attached to the L-shaped cap 811B. A trapezoidal shape is used. The shape is not limited to a trapezoidal shape, and may be other shapes such as a stepped rectangular shape. In the sixth modification, since the inside of the main body of the L-shaped cap 811B and the ink storage chamber in the ink receiving portion 860 communicate with each other, the opening of the ink storage chamber is the recording head 7A in the covered state. , 7B must be configured to be blocked by the lower surface. Therefore, in the sixth modification, as shown in FIG. 27C, the shape of the bottom surface of the recording heads 7A and 7B can block the opening of the ink storage chamber.

With the configuration as described above, according to the sixth modification, even if the contact end portion of the wiper member 840 jumps up at the end of the wiping process and causes ink to fly downward, the width W1 of the contact end portion The flying ink can be received in the ink storage chamber having a wide width W3. When ink scatters in the machine, it not only stains the inside of the apparatus, but also floats inside the apparatus as ink mist and may adhere to the linear encoder sheet 42, the disk-type encoder sheet 34, etc. However, according to the sixth modification, such a problem is unlikely to occur.
Moreover, according to the sixth modification, the width W1 of the contact end portion of the wiper member 840 is formed wider than the width W2 of the nozzle surface, so that the entire nozzle surface can be wiped by the wiper member 840. In the sixth modification, the width W1 of the contact end portion of the wiper member 840 is formed wider than the width W2 of the nozzle surface, but the width W1 of the contact end portion of the wiper member 840 is the width of each recording head. The width may be narrower than the width W2 of the nozzle surface as long as the two nozzle rows formed on the nozzle surface can be wiped. In this case, the bottom surface of the recording heads 7A and 7B can use a general rectangular shape.

[Modification 7]
Next, a modified example of the movement path of the rack 913 in the second embodiment (hereinafter, this modified example is referred to as “modified example 7”) will be described.
FIGS. 28A and 28B are explanatory views schematically showing the operation of the capping unit 910 in the present modification 7. FIG.
In the seventh modification, as in the second embodiment, the movement path of the rack 913 that moves up and down by the rotation of the stepping motor 531 is regulated by the guide rail 934. The lower end of the guide rail 934 of this modification 7 is bent so that the wiper member 940 that is in contact with the nozzle surfaces of the recording heads 7A and 7B is displaced in a direction away from the nozzle surface, as shown. Accordingly, the wiper member 940 moves downward from the wiping operation start position, moves along the nozzle surface while contacting the nozzle surface in a bent state, and moves away from the nozzle surface in the vicinity of the lower end of the nozzle surface. Displaces and exits below the lower end of the nozzle surface. The displacement of the wiper member 940 in the direction away from the nozzle surface in the vicinity of the lower end of the nozzle surface in this manner reduces the amount of deflection of the wiper member 940 when the wiper member 940 passes through the lower end of the nozzle surface. As a result, when the wiper member 940 passes through the lower end of the nozzle surface, it is possible to suppress the occurrence of a problem in which ink is scattered by restoring the bending.

As described above, the ink jet printer according to the first and second embodiments (including the respective modifications) is applied to the paper 12 as the recording material from the nozzle that is the discharge port on the nozzle surface (discharge surface) that is not parallel to the horizontal plane. The recording heads 7A and 7B for discharging ink droplets, the caps 111B and 411B as cap members for covering the nozzle surfaces of the recording heads 7A and 7B, and the nozzle surfaces of the recording heads 7A and 7B by the caps 111B and 411B The image forming apparatus includes a driving unit 130 as a moving unit that relatively moves the caps 111B and 411B and the recording heads 7A and 7B so as to switch between a covering state that covers and a non-covering state that covers. The printer includes discharge ports 160a, 260a, and 260b that are disposed vertically below the opening edge 111a of the caps 111B and 411B that are in contact with the nozzle surfaces of the recording heads 7A and 7B, and discharge the received ink. As a discharged ink passage for transporting ink discharged from the ink receiving members 160, 260, 460 and the discharge ports 160a, 260a, 260b of the ink receiving members 160, 260, 460 to a waste liquid tank 151 as a discharged ink container. The discharge pipe 114B. Accordingly, even if the ink remaining in the caps 111B and 411B or the ink adhering to the opening edge portion 111a of the caps 111B and 411B drips from the caps 111B and 411B during or after the decap, the ink receiving member 160, Since it can be received at 260 and 460, in-flight contamination is suppressed. In addition, the ink received by the ink receiving members 160, 260, and 460 is discharged from the discharge ports 160a, 260a, and 260b provided in the ink receiving members 160, 260, and 460, passes through the discharge pipe 114B, and the waste liquid tank 151. It is conveyed to. Therefore, it can be avoided that the ink received by the ink receiving members 160, 260, and 460 is solidified on the ink receiving member as it is. As a result, it is difficult for the ink dripping from the ink receiving members 160, 260, and 460 to overflow from the ink receiving members 160, 260, and 460, and the ink dripping from the cap is continuously received. Therefore, it is possible to prevent in-machine contamination with ink for a long time.
In the first and second embodiments (including the modifications), the drive unit 130 moves the caps 111B and 411B to move the caps 111B and 411B relative to the recording heads 7A and 7B. In addition, since the ink receiving members 160, 260, and 460 are held by the caps 111B and 411B, even if the caps 111B and 411B are moved by the driving unit 130 after the decap, the caps 111B and 411B are moved during or after the movement. The ink that drips can also be received by the ink receiving members 160, 260, and 460.
In the first embodiment (including each modification), the discharge ports 160a, 260a, and 260b of the ink receiving members 160 and 260 are located directly below the opening edge portion 111a of the cap 111B. Ink flowing out from the cap 111B can be directly received in the vicinity of the discharge ports 160a, 260a, 260b, and the ink received by the ink receiving members 160, 260 can be efficiently discharged from the discharge ports 160a, 260a, 260b. Can do.
In the first modification, the ink receiving member 260 has a discharge port directly below the position where the discharge ports on the nozzle surfaces of the recording heads 7A and 7B are located when the covering state and the non-covering state are switched. Since 260a and 260b are positioned, most of the ink falling along the nozzle surfaces of the recording heads 7A and 7B can directly enter the discharge ports 260a and 260b. Can be efficiently discharged from the discharge ports 260a and 260b.
In the first embodiment (including each modification), the ink receiving members 160 and 260 have inclined surfaces that are inclined downward toward the discharge ports 160a, 260a, and 260b. The ink received at 260 can be efficiently discharged from the discharge ports 260a and 260b.
In the first and second embodiments (including the modifications), ink received by the ink receiving member is sucked from the discharge ports 160a, 260a, and 260b provided in the ink receiving members 160, 260, and 460. Suction pumps 150, 350A, and 350B are provided as ink receiving suction means for feeding into the waste liquid tank 151 through the discharge pipe 114B. Thereby, compared with the case where ink is transported to the waste liquid tank 151 by its own weight, the ink can be transported to the waste liquid tank 151 quickly.
In the second modification, the suction pump 350A serving as a cap suction unit that sucks the inside of the cap 111B from the suction port provided in the cap 111B via the suction pipe 114A serving as an ink suction passage, and the suction unit for receiving the ink. Since the suction pump 350B is independently provided, the suction pipe 114A and the discharge pipe 114B can be sucked at arbitrary timings without switching the shielding state and the open state of the suction pipe 114A and the discharge pipe 114B, respectively. Can do. Therefore, it is not necessary to provide a configuration for switching between the shielded state and the open state of the suction tube 114A and the discharge tube 114B. In addition, since the suction tube 114A and the discharge tube 114B can be sucked independently, the suction operation can be executed without being affected by the situation of the other tube, and the degree of freedom of the suction operation is increased.
On the other hand, in Embodiments 1 and 2 described above (including modifications other than Modification 2), the interiors of the caps 111B and 411B are introduced from the suction ports provided in the caps 111B and 411B through the suction pipe 114A. Since the suction pump 150 which is a common suction means is used as the suction means for the cap and the suction means for receiving the ink, the number of parts can be reduced, and the cost and space can be reduced.
In the first embodiment (including each modification excluding the second modification), the tube crushing portion 161a as the discharge ink passage shielding means for shielding the discharge pipe 114B and the tube crushing portion 161a are controlled. And a control unit as a control unit that switches between a shielded state that shields the discharge pipe 114B and an open state that opens the discharge pipe 114B at a predetermined discharge ink path switching timing. Even when the suction pump 150 which is a common suction means is used, it is possible to suck only the cap 111B side without sucking the ink receiving member side.
Moreover, in the said Embodiment 1 (each modification except the said modification 2 is included), as for the discharge pipe 114B shielded by the tube crushing part 161a, an internal channel | path is shielded by being crushed by applying an external pressure. The tube crushing portion 161a is constituted by an external pressure applying member that applies external pressure to the tube member. Therefore, the shielding state and the open state of the discharge pipe 114B can be switched with a simple mechanism.
Further, the first embodiment (including each modification excluding the second modification) includes a tube crushing portion 161a as an ink suction passage shielding means that shields the suction tube 114A, and the control unit is a tube. Since the crushing portion 161a is controlled to switch between the shielded state for shielding the suction pipe 114A and the opened state for opening, at a predetermined ink suction passage switching timing, the suction means for the cap and the suction means for receiving the ink are common suction means. Even when the suction pump 150 is used, it is possible to suck only the ink receiving member side without sucking the cap 111B side.
Further, in the first embodiment (including each modification excluding the second modification), the suction pipe 114A shielded by the tube crushing portion 161a is crushed by applying external pressure to shield the internal passage. The tube crushing portion 161a is constituted by an external pressure applying member that applies external pressure to the tube member. Therefore, the shielding state and the open state of the suction pipe 114A can be switched with a simple mechanism.
Moreover, in the said Embodiment 1 (each modification except the said modification 2 is included), a control part makes the discharge pipe 114B and the suction pipe 114A into a shielding state simultaneously during a predetermined shielding period. By controlling, it is possible to avoid problems such as the inside of the suction tube 114A and the discharge tube 114B coming into contact with the atmosphere, the remaining ink being dried, and the ink sticking inside the suction tube 114A and the discharge tube 114B.
In the first embodiment (including each modification excluding the second modification), the control unit controls the discharge pipe 114B and the suction pipe 114A to be simultaneously opened during a predetermined opening period. Thus, both the ink in the cap and the ink on the ink receiving member can be sucked at the same time, and the processing time can be shortened as compared with the case of sucking them at different times.
In the first embodiment (including each modification excluding the second modification), the shielding means of the discharge pipe 114B and the suction pipe 114A moves the tube crushing portion 161a, which is the same shielding member, to a predetermined position. Thus, each shielding state and opening state are switched, and the control unit switches between each shielding state and opening state by controlling the movement of the tube crushing portion 161a. Thereby, the shielding state and the open state of the discharge pipe 114B and the suction pipe 114A can be switched with a simple mechanism.

7A, 7B, 1007, 1107 Recording head 100 Maintenance unit 110, 510, 910 Capping part 111A, 111B, 411B Cap 111a Opening edge 113, 413, 513, 913 Rack 114A, 514 Suction pipe 114B Discharge pipe 120 Empty discharge part 130 , 530 Drive unit 131, 531 Stepping motor 140 Wiping unit 141, 540, 840, 940 Wiper member 150, 350A, 350B, 1050 Suction pump 151 Waste liquid tank 160, 260, 460 Ink receiving member 161 Slider 161a Tube crushing unit 162 Lock lever 163 Unlocking projection 1011, 1111 Cap 260 a, 260 b Discharge port 411 b Air release hole 416 Air release valve 511 B, 611 B, 7 1B, 811B L-shaped cap 534,934 guide rails 560,660,760,860 ink receiving 719 absorber

JP-A-10-58694

Claims (15)

A recording head that discharges ink droplets from a discharge port on a discharge surface that is not parallel to a horizontal plane to a recording material;
A cap member for covering the ejection surface of the recording head;
In an image forming apparatus having a moving means for moving the cap member and the recording head relative to each other so as to switch between a covering state in which the discharge surface of the recording head is covered by the cap member and an uncovering state in which the recording surface is not covered.
An ink receiving member disposed at a position vertically below the opening edge of the cap member that contacts the ejection surface of the recording head and having a discharge port for discharging the received ink;
Possess a discharge ink passage for conveying the ink to be discharged from the discharge port of the ink receiving member to a waste ink container,
The ink receiving member is configured such that the discharge port is positioned directly below a position where the discharge port on the discharge surface of the recording head is positioned when the covering state and the non-covering state are switched. image forming apparatus characterized by there. The image forming apparatus according to claim 1.
The moving means is configured to move the cap member relative to the recording head by moving the cap member.
The image forming apparatus, wherein the ink receiving member is held by the cap member. The image forming apparatus according to claim 1 or 2,
The image forming apparatus according to claim 1, wherein the discharge port of the ink receiving member is located directly below the opening edge of the cap member. The image forming apparatus according to any one of claims 1 to 3 ,
The image forming apparatus according to claim 1, wherein the ink receiving member has a slope inclined downward toward the discharge port. The image forming apparatus according to any one of claims 1 to 3 ,
An ink receiving suction means for sucking ink received by the ink receiving member from a discharge port provided in the ink receiving member and feeding the ink to the discharged ink container through the discharged ink passage. Forming equipment. The image forming apparatus according to claim 5 .
A cap suction means for sucking the inside of the cap member from the suction port provided in the cap member via an ink suction passage;
An image forming apparatus, wherein the ink receiving suction means and the cap suction means are provided independently. The image forming apparatus according to claim 5 .
A cap suction means for sucking the inside of the cap member from the suction port provided in the cap member via an ink suction passage;
A common suction means is used as the ink receiving suction means and the cap suction means. The image forming apparatus according to claim 7 .
A discharge ink passage shielding means for shielding the discharge ink passage;
An image forming apparatus comprising: control means for controlling the discharge ink passage shielding means to switch between a shielding state for shielding the discharge ink passage and an open state for opening the discharge ink passage at a predetermined discharge ink passage switching timing.   A recording head that discharges ink droplets from a discharge port on a discharge surface that is not parallel to a horizontal plane to a recording material;
  A cap member for covering the ejection surface of the recording head;
  In an image forming apparatus having a moving means for moving the cap member and the recording head relative to each other so as to switch between a covering state in which the discharge surface of the recording head is covered by the cap member and an uncovering state in which the recording surface is not covered.
  An ink receiving member disposed at a position vertically below the opening edge of the cap member that contacts the ejection surface of the recording head and having a discharge port for discharging the received ink;
  A discharged ink passage for conveying ink discharged from the discharge port of the ink receiving member to a discharged ink container;
  Ink receiving suction means for sucking ink received by the ink receiving member from a discharge port provided in the ink receiving member and feeding the ink to the discharged ink container through the discharged ink passage;
  A suction means for a cap for sucking the inside of the cap member from the suction port provided in the cap member via an ink suction passage;
  A discharge ink passage shielding means for shielding the discharge ink passage;
  Control means for controlling the discharged ink passage shielding means to switch between a shielded state for shielding the discharged ink passage and an opened state for opening the discharged ink passage at a predetermined discharged ink passage switching timing;
  A common suction means is used as the ink receiving suction means and the cap suction means. The image forming apparatus according to claim 8 or 9,
The discharge ink passage shielded by the discharge ink passage shielding means is a flexible tube member whose internal passage is shielded by being crushed by applying external pressure, and which is restored by releasing the external pressure and the internal passage is opened. Consists of
The image forming apparatus according to claim 1, wherein the discharge ink passage shielding means includes an external pressure applying member that applies the external pressure to the tube member. The image forming apparatus according to any one of claims 8 to 10 ,
An ink suction passage shielding means for shielding the ink suction passage;
The image forming apparatus according to claim 1, wherein the control means controls the ink suction passage shielding means to switch between a shielding state for shielding the ink suction passage and an opening state for opening the ink suction passage at a predetermined ink suction passage switching timing. The image forming apparatus according to claim 11.
The ink suction passage shielded by the ink suction passage shielding means is a flexible tube member whose internal passage is shielded by being crushed by applying external pressure, and which is restored by releasing the external pressure and the internal passage is opened. Consists of
The image forming apparatus according to claim 1, wherein the ink suction passage shielding means includes an external pressure applying member that applies the external pressure to the tube member. The image forming apparatus according to claim 11 or 12,
The image forming apparatus according to claim 1, wherein the control means simultaneously puts the discharged ink passage shielding means and the ink suction passage shielding means into a shielding state during a predetermined shielding period. The image forming apparatus according to any one of claims 11 to 13,
The image forming apparatus according to claim 1, wherein the control means simultaneously opens the discharged ink passage shielding means and the ink suction passage shielding means during a predetermined opening period. The image forming apparatus according to any one of claims 11 to 14,
The discharged ink passage shielding means and the ink suction passage shielding means are switched between a shielding state and an open state by moving the same shielding member to a predetermined position.
The image forming apparatus according to claim 1, wherein the control unit switches between the shielding state and the open state by controlling movement of the same shielding member.

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