JP5656105B2 - 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 thereof. 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.

17A to 17E 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 211 is disposed outside the image forming area of the recording head 207 in the main scanning direction. When the recording head 207 is moved to the maintenance unit as shown in FIG. 17A during the ink suction process, as shown in FIG. 17B, the ejection surface of the recording head 207 facing downward in the vertical direction is changed. A capping operation for covering with the cap member 211 is performed from below. Thereby, the inside of the cap member 211 covering the discharge surface is in a sealed state. Then, when the inside of the cap member 211 is sucked by the suction pump 250 connected to the suction port provided in the cap member 211, the cap member 211 is attracted to the ejection surface of the recording head 207, 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 out ink is discharged from the suction port to the suction pump 250 side, but a part of the ink stays inside the cap member 211 as shown in FIG. Thereafter, when the operation of the suction pump 250 is stopped, the suction force of the cap member 211 with respect to the ejection surface of the recording head 207 is weakened, and the cap member 211 can be easily separated from the recording head 207. As shown in FIG. 17D, a decap operation for separating the cap member 211 from the recording head 207 is performed to release the inside of the cap member 211 to the atmosphere, and then the suction pump 250 is operated again. As a result, as shown in FIG. 17E, the ink accumulated in the cap member 211 is discharged from the suction port to the suction pump 250 side. In the image forming apparatus of the present example, the ink suction process is performed with the ejection surface of the recording head 207 facing down in the vertical direction. Therefore, the cap facing the ejection surface of the recording head 207 is shown in FIG. The opening surface of the member 211 is in a state of facing directly above the vertical direction. For this reason, there is almost no concern that ink accumulated inside the cap member 211 will spill 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.

18A and 18B are explanatory diagrams for explaining the ink suction process in the horizontal discharge type image forming apparatus.
In a horizontal discharge type image forming apparatus, normally, during ink suction processing, as shown in FIG. 18A, the discharge surface of the recording head 307 facing right in the vertical direction is covered with a cap member 311 from the horizontal direction. Perform capping operation. When a suction operation is performed by a suction pump (not shown), the cap member 311 is attracted to the discharge surface of the recording head 307, 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 311 is in a hermetically sealed state, ink does not leak from a contact portion between the cap member 311 and the ejection surface of the recording head 307. A part of the ink sucked out by such a suction operation remains in the cap member 311 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 311 away from the recording head 307, the opening surface of the cap member 311 becomes the vertical surface. Since they are parallel, the ink in the cap member spills out from the opening surface. Therefore, in such a horizontal discharge type image forming apparatus, it is necessary to remove ink in the cap member before decap.

  When the ink in the cap member is removed before the decap, the ink flows into the cap member 311 through the ejection port of the recording head 307 and the ink in the cap member is removed if the inside of the cap member is kept sealed. It is not possible. Therefore, it is necessary to perform the suction operation after the inside of the cap member 311 is communicated with the atmosphere before decap and the inside of the cap member is opened to the atmosphere. The image forming apparatus disclosed in Patent Document 1 discloses a configuration that allows the inside of a cap member to be opened to the atmosphere before decap. In this configuration, the adsorbing portion of the cap member adsorbing to the discharge 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, in the configuration described in Patent Document 1, a notch groove (communication hole) is formed in the adsorbing portion of the cap member adsorbing to the discharge surface, and the adsorbing portion is compressed and deformed to close the notch groove. The inside of the cap member is sealed. In such a configuration in which the notch groove is closed by compressive deformation, the sealing performance between the ejection surface of the recording head and the cap member is low, and the inside of the cap member can be stably and reliably sealed during ink suction processing. difficult. Therefore, there is a problem that it is difficult to realize a stable ink suction process. In particular, when the material of the suction portion is further deteriorated due to continued use, it becomes difficult to appropriately compress and deform and it becomes difficult to close the notch groove, and it becomes more difficult to realize a stable ink suction process.

  The above problems are not limited to the horizontal ejection type image forming apparatus, and may occur in the same manner as long as the image forming apparatus has a configuration in which it is effective to remove ink in the cap member before decap. . Therefore, for example, in the image forming apparatus having a configuration in which the ink in the cap member may spill out when the decap operation is performed with the ink remaining in the cap member, the same problem may occur. Even in a vertical ejection type image forming apparatus, there is a possibility that ink in the cap member may spill out during decap due to vibration, etc. In order to prevent this, the ink in the cap member before decap Similar problems may arise when adopting a configuration in which is removed.

  The present invention has been made in view of the above problems, and an object of the present invention is to seal the inside of a cap member during ink suction processing in a configuration in which the ink in the cap member can be removed before decap. An image forming apparatus with improved performance is provided.

To achieve the above object, the invention according to claim 1, in a state where the ejection surface is substantially parallel to the vertical plane, the recording which ejects ink droplets from the discharge ports on the discharge surface to the recording medium and the head, in a state in which substantially parallel the discharge surface with respect to a vertical plane, and the cap member for covering the ejection face of the recording head, and a covering state of covering the ejection surface of the recording head by the cap member a first moving means for the uncoated and uncoated state and the cap member to switch and the recording head are relatively moved, a suction means for sucking the inside of the cap member from the suction port provided in the cap member , in order to communicate the inside and the outside of the cap member above Symbol covering state, a communication hole provided in the portion which becomes vertical upper portion of the cap member, and the lid member for closing the communication hole, the Lid member A second moving means to further relative movement between the open state and the off switched so lid member and the cap member for opening the closed state and the communicating hole for closing the communication hole, the first moving means, the second and control means for controlling the moving means and the suction means, said control means controls said first moving means and the discharge surface of the recording head to the coating state, and controlling said second moving means and by sucking the sealing operation for establishing a sealed state in which the communicating hole in the closed state, the inside of the O Ri said cap member above Symbol suction means the closed state, the sealing sucking ink from said discharge port a suction operation, after execution of the closed suction operation, the discharge surface of the recording head while the above coating state, the communication hole by controlling the second moving means covering the open state to the open state Establishment That cover opening operation and, by sucking the inside of the O Ri said cap member to said suction means in the covering open, the cap for sucking and discharging the in-click accumulated inside of the cap member to the outside of the cap member an ink sucking operation, and is characterized in that by controlling the first moving means to perform the, and uncoated operation to the uncovered discharge side of the recording head.
According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, a cap holding member that holds the cap member in a state in which the cap member and the recording head are movable in a contacting / separating direction. A biasing means for biasing the cap member from the cap holding member toward the recording head along the contact / separation direction, and a movement for relatively moving the cap holding member and the recording head along the contact / separation direction And the lid member is positioned on the cap holding member and is connected to the communication hole of the cap member in conjunction with the relative movement of the cap holding member and the recording head by the moving mechanism. It is arranged at a position approaching and moving away from Te, the use of the movement mechanism as the first moving means and the second moving means, in the closed operation, the upper Symbol moving mechanism by the cap holding member and the upper Establishing the sealed state by relatively moving direction toward the recording head from each other, in the coating opening movement, after execution of the closed suction operation, and the cap holding member and said recording head by said moving mechanism the are relatively moved away from each other, the discharge surface of the recording head with a cap member which is urged by the urging means while the above coating state, is separated the lid member from the communicating hole above in the open state, to establish the coating open, in the uncoated operation, by relatively moving in a direction to further separate the said cap holding member and said recording head by said moving mechanism, the recording of the cap member the so spaced from the head discharge surface of the recording head is characterized in the to Turkey in the uncoated state.
According to a third aspect of the present invention, in the image forming apparatus according to the second aspect, the communication hole is open to a side portion of the cap member positioned in a lateral direction with respect to the contact / separation direction, and the lid member Is arranged at a position to slide relative to the side portion of the cap member in conjunction with the relative movement of the cap holding member and the recording head by the moving mechanism.
According to a fourth aspect of the present invention, in the image forming apparatus of the second aspect, the communication hole is open to a back surface portion of the cap member with respect to the recording head, and the lid member is formed in the communication hole. The taper is tapered toward the cap member, and is disposed at a position facing the communication hole of the cap member .

  In this image forming apparatus, a lid member for closing the communication hole provided in the cap member is provided, the communication hole is closed by this lid member, the communication hole is closed, and the lid member is closing the communication hole By retracting, the communication hole can be opened. With such a configuration, the inside of the cap member during the ink suction process is more sealed than the conventional configuration in which the communication hole is closed by compression deformation and the communication hole is opened by restoring compression deformation. Can be secured.

  According to the present invention, it is possible to obtain an excellent effect that it is possible to remove the ink in the cap member before the decap, while ensuring high sealing performance inside the cap member during the ink suction process.

It is a schematic block diagram which shows the principal part of the inkjet printer which concerns on 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 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)-(c) is a schematic diagram for demonstrating a structure and operation | movement when the cap for suction in the maintenance unit is seen from a horizontal direction. (A)-(c) is explanatory drawing which shows the relationship between the rotation angle (rotation position) of the cam for cam movement, and the state of a capping part. (A)-(c) is explanatory drawing which shows the air release structure of the cap in the modification 1. FIG. It is explanatory drawing which shows the air release structure of the cap in the modification 2. It is explanatory drawing which shows the air release structure of the cap in the modification 3. (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.

Hereinafter, embodiments of the present invention 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 showing a main part of an ink jet printer according to the present 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 present 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 present 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 of the present embodiment configured as described above, the paper 12 is separated and fed one by one from the paper feeding unit, and the conveyance direction of the fed paper 12 is guided upward in the vertical direction by the guide 15. . 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. The caps 111 </ b> A and 111 </ b> B 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 113 a provided in the rack 113. 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 back side opposite to the opening, and one end of the suction tube 114 is connected to the suction port. A suction pump 150 as a suction means is connected to the other end of the suction pipe 114. 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 114 to the waste liquid tank 151 by the suction force of the suction pump 150.

  In this embodiment, as will be described later, the inside of the cap is communicated with the outside while the nozzle surface of the recording heads 7A and 7B is covered with the cap 111B, and the inside of the cap is opened to the atmosphere. For this reason, the cap 111B of this embodiment is provided with an air release hole 111b, which is a communication hole for communicating the inside and outside of the cap, on the back surface of the cap 111B. However, in order to perform the nozzle suction process described above, the inside of the cap needs to be hermetically sealed, so the air opening hole 111b must be closed. Therefore, in this embodiment, the air release valve 116 as a lid member that closes the air release hole 111b is provided. The atmosphere release valve 116 is attached to a position facing the atmosphere release hole 111b on the inner wall of the rack 113 in a state in which the atmosphere release valve 116 is slidable in the horizontal direction (left and right direction in FIG. 6). The slide movement range is limited by a guide groove (not shown) provided in the rack 113. The atmosphere release valve 116 is urged from the rack 113 to the right side (atmosphere release hole 111b side) in FIG.

In this embodiment, when the rack 113 is in the retracted position, the cap 111B is slid to the most advanced position with respect to the rack 113 by the biasing force of the cap compression spring 118, as shown in FIG. Positioned there. In addition, the air release valve 116 is also positioned there while being slid to the most advanced position with respect to the rack 113 by the biasing force of the air release compression spring 117. At this time, as shown in FIG. 6A, the air release valve 116 is in a state of being separated from the air release hole 111b provided in the cap 111B located at the most advanced position.
On the other hand, when the rack 113 is in the forward position, as shown in FIG. 6B, the cap 111B abutting against the nozzle surfaces of the recording heads 7A and 7B resists the urging force of the cap compression spring 118. 113 is located in the retracted position pushed inward. When the cap 111B is located at the retracted position with respect to the rack 113, the atmosphere release valve 116 contacts the back surface of the cap compression spring 118, and inward of the rack 113 against the urging force of the atmosphere release compression spring 117. Pushed in. Therefore, 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 air release hole 111b provided in the back surface of the cap is the air release valve 116. Therefore, the cap is hermetically sealed. As a result, the nozzle suction process is enabled.

  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 present embodiment, in order to recover and maintain the ejection performance of the recording heads 7A and 7B, at a predetermined timing, each recording head 7A and 7B is opposed to the idle ejection unit 120, and the idle ejection process for idly ejecting ink from the nozzles. I do. 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. 7 is a perspective view showing 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 of the capping unit 110 (not shown in FIG. 7 for explanation). 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. 8, the cap moving cam 135 is disposed at a position opposite to the pin 115 provided on the back surface of the rack 113 of the capping unit 110 (the surface opposite to the surface on which the caps 111A and 111B are provided). Is done. The cap moving cam 135 of this 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. 9, and a rack is formed in the cam groove 135c. It is assembled in a state where the pin 115 on the back surface of 113 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 115 of the rack 113 moves in the cam groove of the cap moving cam 135 and the rack moves. 113 is displaced in the horizontal direction. Accordingly, by controlling the rotation angle of the cap moving cam 135 by the stepping motor 131, the caps 111A and 111B are moved forward in the direction of approaching the recording heads 7A and 7B to be in the covering state, or the recording heads 7A , 7B, the caps 111A, 111B can be retracted in the direction of separating them to be uncovered.

  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 present 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. ing. 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 present 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. 10 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 this 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 for wiping. . In the present 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 present embodiment, by moving the wiper member 141 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 present 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 to be driven by receiving 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 this 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. 11 is a flowchart showing a flow of maintenance processing performed using the maintenance unit 100.
12A to 12C are schematic views for explaining the configuration and operation when the suction cap 111B in the maintenance unit 100 is viewed from the horizontal direction. In FIG. 12, two cap compression springs 118 are illustrated as one spring.
FIGS. 13A to 13C are explanatory diagrams showing the relationship between the rotation angle (rotation position) of the cap moving cam 135 and the state of the capping unit 110. FIG.

  In this embodiment, the maintenance process 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. 12C, and the idle ejection unit 120 is similarly 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 rack 113 horizontally, and the cap 111B is advanced toward the recording head 7A (S4). 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. 13A, the pin 115 on the back surface of the rack 113 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, and the nozzle surface is covered, and the air opening hole 111b provided on the back surface of the cap 111 is open to the atmosphere. The air release valve 116 urged by the compression spring 117 is closed. 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. Thus, ink is sucked out from the nozzles of the first recording head 7A 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 114. 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).

  Here, when the suction operation is stopped, a part of the ink sucked from the nozzle remains in the cap 111B. In this embodiment, since the cap 111B is capped from the horizontal direction with respect to the nozzle surface parallel to the vertical surface, if the ink is left in the cap 111B, the cap 111B is separated from the nozzle surface. The ink in the cap flows out from the opening of the cap and the inside of the machine is contaminated with ink. Therefore, in the present embodiment, the following processing operation is executed.

  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). As a result, as shown in FIG. 13B, the pin 115 on the back surface of the rack 113 is positioned 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 Positioned at the atmospheric release position (between the forward position and the backward position) shown in FIG. When the rack 113 is located at the atmospheric release position, the cap 111B is in contact with the nozzle surface of the recording head 7A by the urging force of the cap compression spring 118, but the atmospheric release valve 116 is provided on the back surface of the cap. It will be in the state spaced apart from the air release hole 111b. As a result, the atmosphere opening hole 111b is opened, and the inside of the cap 111B is opened to the atmosphere through the atmosphere opening hole 111b with the opening being blocked by the nozzle surface. In this state, ink does not flow out from the opening of the cap 111B. Moreover, the air opening hole 111b 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 111b is opened, ink does not leak from the atmosphere opening hole 111b.

  When the cap 111B is opened to the atmosphere in this way, the control unit waits for a predetermined time to elapse (S11), and then reverses the stepping motor 131 to drive the suction pump 150 to execute the suction operation (S12). . At this time, since the inside of the cap is open to the atmosphere through the air opening hole 111b, even if the inside of the cap is sucked by the suction pump 150, ink is not sucked out from the nozzles of the recording head 7A, and the inside of the cap. Ink can be collected from the suction port through the suction pipe 114 to the waste liquid tank 151. 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 (S13).

  After the ink in the cap 111B is removed in this way, the control unit causes the stepping motor 131 to rotate forward to further retract the rack 113 (S14), and the number of pulses (step number) of the stepping motor 131 becomes the predetermined number of pulses. When it reaches, the rotation of the stepping motor 131 is stopped (S15). As a result, as shown in FIG. 13C, the pin 115 on the back surface of the rack 113 is positioned in the short side portion of the cam groove 135c of the cap moving cam 135, and the rack 113 is shown in FIG. Positioned in the retracted position shown. As the rack 113 moves back to the retracted position, the cap 111B follows the movement of the rack 113 and is separated from the nozzle surface of the recording head 7A and is decapded.

  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 movement 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. Accordingly, 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 114. 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 is positioned at the atmospheric release position (between the forward position and the backward position) shown in FIG. As a result, the atmosphere opening hole 111b is opened, and the inside of the cap 111B is opened to the atmosphere through the atmosphere opening hole 111b with the opening being blocked by the nozzle surface. Then, 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 (S29). At this time, since the inside of the cap is opened to the atmosphere through the atmosphere opening hole 111b, 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 head 7B. Ink can be collected from the suction port through the suction pipe 114 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 (S30).

  When the ink in the cap 111B is removed in this way, the control unit causes the stepping motor 131 to rotate forward to further retract the rack 113 (S31), and the number of pulses (step number) of the stepping motor 131 becomes the predetermined number of pulses. When it reaches, the rotation of the stepping motor 131 is stopped (S32). As a result, the rack 113 is positioned at the retracted position shown in FIG. 12C, and the cap 111B is decapped. 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 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 of the present embodiment is configured such that when the second recording head 7B faces the suction cap 111B, the first recording head 7B faces the capping cap 111A. In the present embodiment, the positions where the two recording heads 7A and 7B face the caps 111A and 111B are the home positions 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 present embodiment, since the nozzle surfaces of the recording heads 7A and 7B are parallel to the vertical surface during the ink suction process, the opening surface of the cap 111B for capping the nozzle surface also becomes a vertical surface, and after the ink suction process. When the decapping is performed as it is, the ink remaining in the cap 111B spills out from the opening surface. However, according to the present embodiment, after the ink suction process and before the decap, the inside of the cap 111B is opened to the atmosphere, and the ink remaining in the cap 111B can be discharged by the suction pump 150. Therefore, since the ink in the cap 111B is discharged before the decap, it is possible to prevent the ink from spilling from the opening of the cap 111B that has been blocked by the nozzle surface during the decap.
Moreover, in the present embodiment, as an arrangement for releasing the atmosphere before decap, an atmosphere release valve 116 is provided as a lid member for closing the atmosphere release hole 111b that is a communication hole provided in the cap 111B. The open air valve 111b is closed by closing the open air hole 111b with the open valve 116, and the open air hole 111b is opened by retracting the open air valve 116 closing the open air hole 111b. Adopted. By adopting such a configuration, the inside of the cap at the time of ink suction processing is made more than the conventional configuration in which the communication hole is closed by compression deformation and the communication hole is opened by restoring compression deformation. High sealing performance can be ensured, and ink suction processing can be performed stably and reliably.

[Modification 1]
Next, a modified example of the configuration for releasing the cap 111B in the above embodiment to the atmosphere (hereinafter, this modified example will be referred to as “modified example 1”) will be described.
14 (a) to 14 (c) are explanatory views showing the air release configuration of the cap 111B in the first modification. In FIG. 14, two cap compression springs 118 are illustrated as one spring.
In the first modification, the atmosphere opening hole 111b, which is a communication hole that communicates the inside and outside of the cap, is a side portion of the cap 111B that is located laterally with respect to the direction in which the rack 113 moves horizontally (the left-right direction in FIG. 14). In the first modification, an opening is formed on the upper surface of the cap 111B. The air release valve 116 as a lid member that closes the air release hole 111b slides on the top surface of the cap 111B in conjunction with the relative movement of the rack 113 and the recording heads 7A and 7B. It is attached to the inner wall.

In the first modification, when the rack 113 is in the forward position, as shown in FIG. 14A, the cap 111B that is in contact with the nozzle surfaces of the recording heads 7A and 7B is biased by the compression spring 118 for the cap. It will be located in the retreat position pushed against the rack 113 inside. When the cap 111B is positioned at the retracted position with respect to the rack 113, the atmosphere release valve 116 is positioned at a position to close the atmosphere release hole 111b provided on the upper surface of the cap 111B, as shown in FIG. . As a result, the atmosphere opening hole 111b of the cap 111B is closed by the atmosphere opening valve 116, so that the inside of the cap is sealed.
On the other hand, when the rack 113 is in the atmospheric release position, as shown in FIG. 14B, the cap 111B is still in contact with the nozzle surfaces of the recording heads 7A and 7B by the urging force of the cap compression spring 118. It has become. At this time, as shown in FIG. 14B, the air release valve 116 is positioned at an open position that does not block the air release hole 111b provided on the upper surface of the cap 111B.
On the other hand, when the rack 113 is in the retracted position, as shown in FIG. 14C, the cap 111B is separated from the nozzle surfaces of the recording heads 7A and 7B. At this time, as shown in FIG. 14B, the air release valve 116 is maintained in an open position that does not block the air release hole 111b of the cap 111B.

  According to the first modification, the air opening hole 111b can be provided in the side portion of the cap 111B positioned in the lateral direction with respect to the direction in which the rack 113 moves horizontally (the left-right direction in FIG. 14). Thereby, in the direction in which the rack 113 moves horizontally (the left-right direction in FIG. 14), it is not necessary to arrange the air release valve 116 in the space between the inner wall of the rack 113 and the back surface of the cap 111B. Thus, the maintenance unit 100 can be downsized.

[Modification 2]
Next, another modified example of the configuration for releasing the cap 111B in the above embodiment to the atmosphere (hereinafter, this modified example is referred to as “modified example 2”) will be described.
FIG. 15 is an explanatory diagram showing an air release configuration of the cap 111B in the second modification. In FIG. 15, two cap compression springs 118 are shown as one spring.
In the second modification, the atmosphere opening hole 111b, which is a communication hole that communicates the inside and outside of the cap, is open on the back surface of the cap 111B, as in the case of the above embodiment, but the atmosphere opening valve as a lid member that closes the cap 111B. The shape of 116 is different from that of the above embodiment. Specifically, the shape of the atmosphere release valve 116 of the second modification is a shape that tapers toward the atmosphere release hole 111b, specifically, a conical shape.

  According to the second modification, since the shape of the atmosphere release valve 116 is a tapered shape (conical shape) toward the atmosphere release hole 111b, the component release accuracy and the assembly accuracy are low. Even if the accuracy of the relative position with respect to the opening hole 111b is somewhat worse, if the tip of the atmosphere opening valve 116 can be positioned at a position facing the atmosphere opening hole 111b, the atmosphere opening valve 116 is interlocked with the horizontal movement of the rack 113. Can be inserted into and removed from the atmosphere opening hole 111b. Therefore, component accuracy, assembly accuracy, etc. can be relaxed.

[Modification 3]
Next, still another modified example of the configuration for opening the cap 111B in the above embodiment to the atmosphere (hereinafter, this modified example will be referred to as “modified example 3”) will be described.
FIG. 16 is an explanatory diagram showing an air release configuration of the cap 111B in the third modification.
In the third modification, the atmosphere opening hole 111b, which is a communication hole for communicating the inside and outside of the cap, is obtained by cutting the sides of the back surface and the top surface of the cap 111B in a wedge shape as shown in FIG. The shape is tapered toward the opening side of the cap 111B that contacts the nozzle surfaces of 7A and 7B. On the other hand, the shape of the air release valve 116 serving as a lid member for closing this is a shape tapered toward the air release hole 111b, specifically, a triangular pyramid shape, and the air release valve 116 is fitted into the air release hole 111b. Thus, the atmosphere opening hole 111b is configured to be tightly closed by the atmosphere opening valve 116.

  According to the third modification, since the shape of the atmosphere release valve 116 is a tapered shape (triangular pyramid shape) toward the atmosphere release hole 111b, the accuracy of parts, assembly accuracy, and the like are low. Even if the accuracy of the relative position with respect to the atmosphere opening hole 111b is somewhat poor, the atmosphere opening valve 116 can be inserted into and removed from the atmosphere opening hole 111b in conjunction with the horizontal movement of the rack 113. Therefore, component accuracy, assembly accuracy, etc. can be relaxed.

As described above, the ink jet printer according to the present embodiment (including each modification) is a recording head that ejects ink droplets from the nozzles (ejection ports) on the nozzle surface that is the ejection surface with respect to the paper 12 that is the recording material. 7A, 7B, a cap 111B as a cap member for covering the nozzle surfaces of the recording heads 7A, 7B, and a covering state in which the nozzle surfaces of the recording heads 7A, 7B are covered by the cap 111B and an uncovering state in which the nozzle surfaces are not covered. A driving unit 130 as a first moving unit that relatively moves the cap 111B and the recording heads 7A and 7B so as to switch, and a suction pump as a suction unit that sucks the inside of the cap 111B from a suction port provided in the cap 111B. 150, and a suction pump in a state where the inside of the cap 111B is hermetically sealed by the drive unit 130. The ink vacuuming process sucking the ink from the nozzles by performing the suction operation by 150 is an image forming apparatus that performs a predetermined timing. In this printer, the cap 111B is provided with an air release hole 111b as a communication hole for communicating the inside and the outside of the cap 111B in a covered state. In addition, this printer is divided into an atmosphere release valve 116 as a lid member for closing the atmosphere release hole 111b, a closed state in which the atmosphere release hole 111b is closed by the atmosphere release valve 116, and an open state in which the atmosphere release hole 111b is opened. In order to replace the air release valve 116 and the cap 111B, the driving unit 130 serving as a second moving unit, and when performing ink suction processing, the driving unit 130 covers the nozzle surfaces of the recording heads 7A and 7B. In addition, after the suction operation by the suction pump 150 is performed in a sealed state in which the atmosphere opening hole 111b is closed by the drive unit 130, the drive unit 130 performs the atmosphere while the nozzle surfaces of the recording heads 7A and 7B are covered. The opening 111b is opened and the suction pump 150 performs the suction operation again to collect the cap 111B. Ink liquid sucked to the outside of the cap 111B, then, and a control section as a control means for controlling the recording head 7A, the nozzle surface of 7B uncoated state by the drive unit 130. With such a configuration, after the ink suction process and before the decap, the inside of the cap 111B can be opened to the atmosphere, and the ink remaining in the cap 111B can be discharged by the suction pump 150. Therefore, it is possible to prevent the ink from spilling from the opening of the cap 111B that has been blocked by the nozzle surface during the decap. In addition, as a configuration for opening the atmosphere before decapping, the configuration that switches between the closed state and the open state of the air release hole 111b with the air release valve 116 is adopted, so that the communication hole is closed by compression deformation and the compression is performed. Compared to the conventional configuration in which the communication hole is opened by restoring the deformation, it is possible to ensure a high sealing performance inside the cap during the ink suction process, and to perform the ink suction process stably and reliably. it can.
In addition, the ink jet printer according to the present embodiment (including each modification) holds the cap 111B in a state in which the cap 111B can move in the contacting / separating direction (advancing / retreating direction) in which the recording head 7A, 7B is contacted / separated. A rack 113 as a cap holding member, a cap compression spring 118 as urging means for urging the cap 111B from the rack 113 toward the recording heads 7A and 7B along the advancing / retreating direction, and the rack 113 along the advancing / retreating direction And a drive unit 130 having a cap moving cam 135 as a moving mechanism for moving the recording heads 7A and 7B relative to each other. The atmosphere release valve 116 is located on the rack 113 and has a cap moving cam 135. In conjunction with the relative movement between the rack 113 and the recording heads 7A and 7B by the air, the air opening hole 111b of the cap 111B is moved. The drive unit 130 as the moving mechanism is used as the first moving unit and the second moving unit described above, and the control unit uses the rack 113 by the driving unit 130 when performing the ink suction process. And the recording heads 7A and 7B are moved relative to each other in a direction close to each other to establish a sealed state of the cap 111B, and the suction operation by the suction pump 150 is performed. 7B is moved relative to each other in a direction away from each other, and the air release valve 116 is connected to the air release hole 111b while the nozzle surface of the recording heads 7A and 7B is covered with the cap 111B biased by the cap compression spring 118. And the air release hole 111b is opened, and the suction operation by the suction pump 150 is executed again. Then, the ink accumulated inside the cap 111B is sucked out of the cap 111B, and the drive unit 130 moves the rack 113 and the recording heads 7A and 7B in a further separated direction, thereby moving the cap 111B to the recording heads 7A and 7B. The nozzle surfaces of the recording heads 7A and 7B are controlled so as to be separated from each other. Thereby, the cap 111B and the recording heads 7A and 7B can be relatively moved by the single moving mechanism, and the atmosphere release valve 116 and the cap 111B can be relatively moved.
Further, in the first modification, the air release hole 111b opens to the side portion of the cap 111B (the upper surface of the cap in the first modification example) positioned in the lateral direction with respect to the advancing and retreating direction. The drive unit 130 is disposed at a position that slides with respect to the upper surface of the cap 111B in conjunction with the relative movement between the rack 113 and the recording heads 7A and 7B. This eliminates the need to place the air release valve 116 in the space between the inner wall of the rack 113 and the back surface of the cap 111B in the forward / backward direction of the rack 113, so that the space is reduced and the maintenance unit 100 is downsized. it can.
Further, in Modification 2 and Modification 3, the atmosphere opening hole 111b opens to the back surface of the cap 111B with respect to the recording heads 7A and 7B, and the atmosphere opening valve 116 faces the atmosphere opening hole 111b. It has a tapered shape and is disposed at a position facing the atmosphere opening hole 111b of the cap 111B. Thus, even if the accuracy of the relative position between the atmosphere release valve 116 and the atmosphere release hole 111b is somewhat poor, the atmosphere release valve 116 can be inserted into and removed from the atmosphere release hole 111b in conjunction with the forward and backward movement of the rack 113. Therefore, component accuracy, assembly accuracy, etc. can be relaxed.
In the above-described embodiment (including each modification), the nozzle surfaces of the recording heads 7A and 7B are configured to face directions other than directly below the vertical direction in the covered state. Therefore, the opening surface of the cap 111B that covers the nozzle surface faces in a direction other than directly above the vertical direction. As a result, if the decapping is performed as it is after the ink suction process, the ink remaining in the cap 111B is likely to spill from the opening surface of the cap 111B. In the above embodiment (including each modification), even with such a configuration, the ink remaining in the cap 111B can be removed before the decap, so that the opening surface of the cap 111B during decap. Ink can be prevented from spilling out.
Moreover, in the said embodiment (each modification is included), since the air release hole 111b is provided in the location used as the upper direction of the cap 111B at the time of a covering state, the air release hole 111b is the cap 111B. Compared to the case where the air opening hole 111b is provided at a lower portion in the vertical direction, the atmosphere opening hole 111b is less likely to be blocked by the ink in the cap. As a result, the inside of the cap can be released to the atmosphere more stably.
In addition, the ink jet printer according to the above-described embodiment (including each modification) ejects ink droplets onto the paper 12 in a state where the nozzle surfaces of the recording heads 7A and 7B are substantially parallel to the vertical surface. The so-called horizontal discharge type image forming apparatus configured as described above is configured such that the nozzle surfaces of the recording heads 7A and 7B are parallel to the vertical surface even in the covered state. In the horizontal discharge type image forming apparatus, the configuration of the cap 111B is not required during decap without requiring a configuration such as changing the posture of the recording head so that the nozzle surface is in parallel with the horizontal plane during ink suction processing. It is possible to prevent ink from spilling from the opening surface.

  In the above description, the horizontal discharge type image forming apparatus has been described as an example. However, the present invention is an image forming apparatus having a configuration in which it is effective to remove ink in the cap member before decap. If so, it is not limited to this. Therefore, even in the case of a vertical ejection type image forming apparatus, if there is a possibility that ink in the cap member may spill out during decap due to vibrations, the present invention is applied to prevent this. May be.

3 Carriage 4 Main scanning motor 7A, 7B, 207, 307 Recording head 100 Maintenance unit 110 Capping part 111A, 111B Cap 111b Atmospheric release hole 112 Frame part 113 Rack 114 Suction tube 115 Pin 116 Atmospheric release valve 117 Atmospheric release compression spring 118 Cap compression spring 120 Empty discharge portion 130 Drive portion 131 Stepping motor 132 Gear train 133 Drive shaft 134 Driven gear 135 Cap moving cam 136 Empty discharge portion moving cam 140 Wiping portion 141 Wiper member 150, 250 Suction pump 151 Waste liquid tank 211,311 Cap member

JP-A-10-58694

Claims (4)

In a state where the ejection surface is substantially parallel to the vertical plane, and a recording head for ejecting ink droplets from the discharge ports on the discharge surface to the recording medium,
A cap member for covering the discharge surface of the recording head in a state where the discharge surface is substantially parallel to the vertical surface ;
A first moving means for relatively moving the said cap member and said recording head to switch and the uncovered uncoated and coated state for covering the ejection face of the recording head by the cap member,
A suction means for sucking the inside of the cap member from the suction port provided in the cap member,
For communicating the inside and the outside of the cap member above Symbol covering state, a communication hole provided in the portion which becomes vertical upper portion of the cap member,
A lid member for closing the communication hole,
A second moving means for relatively moving the lid member and the cap member to switch and the open state to open the closed state and the communicating hole for closing the communication hole by the lid member,
Control means for controlling the first moving means, the second moving means, and the suction means;
The control means includes
And controls on the Symbol first moving means and the discharge surface of the recording head in the covering state and a closed operation and establishing a closed state in which the communication hole and controls the second moving means to the closed state ,
By sucking the inside of the cap member Ri by the upper Symbol suction means the closed state, the sealing suction operation sucking the ink from said discharge port,
After execution of the closed suction operation, covering the opening to establish a coating open to the discharge surface of the recording head while the above coating state, the communication hole by controlling the second moving means in the open Operation and
By sucking the inside of the O Ri said cap member to said suction means in the covering open, the ink sucking operation inside the cap to suck discharged to the outside of the cap member in-click accumulated inside of the cap member,
Image forming apparatus and executes a a non-coating operation to the uncovered discharge side of the first controls the moving means in the recording head. The image forming apparatus according to claim 1.
A cap holding member that holds the cap member in a state of being movable in an approaching / separating direction for bringing the cap member and the recording head into contact with each other; and
Biasing means for biasing the cap member from the cap holding member toward the recording head along the contact / separation direction;
A moving mechanism for relatively moving the cap holding member and the recording head along the contact / separation direction;
The lid member is a position on the cap holding member, and is a position where the cap member contacts and separates from the communication hole of the cap member in conjunction with the relative movement of the cap holding member and the recording head by the moving mechanism. Are located in
Using the moving mechanism as the first moving means and the second moving means,
In the sealed operation, to establish the closed state by relatively moving the upper Symbol moving mechanism in a direction close to each other and the cap holding member and the recording head,
In the coating opening movement, after execution of the closed suction operation, it is relatively moved in the direction of away from each other and the cap holding member and said recording head by said moving mechanism, and is biased by the biasing means while the discharge surface of the recording head was the coating state with the cap member, the cap member is separated from said communicating hole in the above open state to establish the coating open,
Above the uncoated operation, by relatively moving in a direction to further separate the said cap holding member and said recording head by said moving mechanism, said a said cap member is separated from the recording head discharge surface of the recording head an image forming apparatus comprising the to Turkey the uncoated state. The image forming apparatus according to claim 2.
The communication hole opens in a side portion of the cap member located in a direction transverse to the contact / separation direction,
The lid member is disposed at a position that slides relative to the side portion of the cap member in conjunction with relative movement between the cap holding member and the recording head by the moving mechanism. Forming equipment. The image forming apparatus according to claim 2.
The communication hole opens on the back surface of the cap member with respect to the recording head,
The image forming apparatus according to claim 1, wherein the lid member has a tapered shape toward the communication hole and is disposed at a position facing the communication hole of the cap member.

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