JP6931479B2 - A device that discharges liquid, a method of attaching multiple liquid discharge heads, and a method of manufacturing a device that discharges liquid. - Google Patents

Description

The present invention relates to a device for discharging a liquid, a method for attaching a plurality of liquid discharge heads, and a method for manufacturing a device for discharging a liquid.

Conventionally, a device for discharging a liquid having a transport member for transporting a medium and a plurality of liquid discharge heads arranged side by side in the transport direction of the medium is known.

For example, in Patent Document 1, an image is formed by ejecting ink from four line heads arranged to face the outer peripheral surface of a drum with respect to a sheet material that is wound around the outer peripheral surface of a rotating drum and is rotationally conveyed. The inkjet recording apparatus to be used is disclosed.

In this inkjet recording apparatus, both ends of each line head are fixed to a pair of pedestals, and the pair of pedestals are fixed to both side plates of the apparatus main body. Positioning of each line head (positioning with respect to the drum) in the normal direction of the drum surface and the circumferential direction of the drum is performed by positioning a pair of pedestals with respect to both side plates of the main body of the apparatus.

To position the pair of pedestals, a dummy head is attached to the pair of pedestals, and a pair of positioning pins arranged at both ends of the dummy head are fitted into a pair of positioning holes formed at both ends of the outer peripheral surface of the drum. Is done by.

Specifically, the pair of positioning pins are composed of stepped pins, and by bringing the pair of pedestals closer to the drum surface, the small diameter portion is positioned on the drum until the end surface of the large diameter portion abuts on the outer peripheral surface of the drum. Fit in. After that, the pair of pedestals are fixed to both side plates of the apparatus main body, and the dummy head and the line head are exchanged for the pair of pedestals.

However, in the method disclosed in Patent Document 1, positioning holes (positioning reference portions) provided in the drum (conveying member) are individually provided for each line head (liquid discharge head).

Therefore, the pair of pedestals that support each line head will be positioned by different positioning holes on the drum. Therefore, the relative positional relationship between the line heads depends on the position accuracy of each positioning hole formed on the drum, and if the position accuracy of the positioning hole is poor, the relative position accuracy between the line heads is poor. Become.

Therefore, in order to improve the relative position accuracy between the line heads by the method disclosed in Patent Document 1, it is necessary to improve the position accuracy of all eight positioning holes formed on the drum, and it is necessary to improve the position accuracy between the line heads. It is difficult to improve the relative position accuracy in.

In order to solve the above-mentioned problems, the present invention is a device for discharging a liquid having a transport member for transporting a medium and a plurality of liquid discharge heads arranged side by side in the transport direction of the medium. Each of the plurality of liquid discharge heads is provided with a head-side positioning portion, the transport member is provided with a transport member-side positioning portion, and the head-side positioning portion and the transport member-side positioning portion are the liquid. It is a positioning unit for determining the positional relationship between the discharge head and the transport member, and the transport member side positioning portion contacts each of the plurality of head side positioning portions by moving the transport member in the transport direction. The above-mentioned positional relationship is determined .

According to the present invention, an excellent effect that the relative position accuracy between the liquid discharge heads can be easily improved is achieved.

It is a schematic diagram which shows the schematic structure of the inkjet recording apparatus in an embodiment. It is a schematic diagram which shows the structure of the image formation part of the inkjet recording apparatus. In the first embodiment, it is explanatory drawing which shows an example of the shape of the pair of head side positioning reference holes provided in each liquid discharge head, and the pair of drum side positioning reference holes provided on a paper transport drum. It is explanatory drawing which shows the positioning process of the first liquid discharge head. It is explanatory drawing which shows the positioning process of the 2nd liquid discharge head. It is a top view of the main part when the liquid discharge head is seen from above. In the second embodiment, it is explanatory drawing which shows an example of the shape of the pair of head side positioning reference holes provided in each liquid discharge head, and the pair of drum side positioning reference holes provided on a paper transport drum. In the second embodiment, it is explanatory drawing which shows another example of the shape of the pair of head side positioning reference holes provided in each liquid discharge head, and the pair of drum side positioning reference holes provided on a paper transport drum. In the second embodiment, it is explanatory drawing which shows still another example of the shape of the pair of head side positioning reference holes provided in each liquid discharge head, and the pair of drum side positioning reference holes provided on a paper transport drum.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[Overall explanation]
FIG. 1 is a schematic diagram showing a schematic configuration of an inkjet recording apparatus according to the present embodiment.
The inkjet recording device 1 of the present embodiment is mainly composed of a paper feeding unit 100, an image forming unit 200, a drying unit 300, and a paper ejection unit 400.

In the inkjet recording apparatus 1, the image forming unit 200 forms an image with ink, which is a liquid for forming an image, on the paper P, which is a recording material which is a sheet material as a medium to be fed from the paper feeding unit 100. .. Then, after the ink adhering to the paper is dried in the drying unit 300, the paper is discharged from the paper ejection unit 400.

[Paper feed section]
The paper feed unit 100 mainly feeds the paper feed tray 110 on which a plurality of sheets P are loaded, the feeding device 120 that separates and feeds the paper sheets one by one from the paper feed tray 110, and the paper to the image forming unit 200. It is composed of a pair of resist rollers 130 to be fed.

As the feeding device 120, any feeding device such as a device using rollers and rollers and a device using air suction can be used. The paper fed from the paper feed tray 110 by the feeding device 120 is fed to the image forming unit 200 by driving the resist roller pair 130 at a predetermined timing after the tip of the paper reaches the resist roller pair 130. NS.

In the present embodiment, the paper feeding unit 100 is not limited in its configuration as long as it feeds the paper P to the image forming unit 200.

[Image forming part]
The image forming unit 200 mainly has a receiving cylinder 201 that receives the fed paper P (medium) and a cylindrical paper conveying drum 210 that carries the paper P conveyed by the receiving cylinder 201 by supporting it on the outer peripheral surface. (Conveying member), an ink ejection unit 220 that ejects ink toward the paper P conveyed by the paper conveying drum 210, and a delivery cylinder 202 that transfers the paper P conveyed by the paper conveying drum 210 to the drying unit 300. It is composed of.

The tip of the paper P transported from the paper feeding unit 100 to the image forming unit 200 is gripped by a paper gripper provided on the surface of the receiving cylinder 201, and is conveyed as the surface of the receiving cylinder 201 moves. The paper conveyed by the receiving cylinder 201 is delivered to the paper conveying drum 210 at a position facing the paper conveying drum 210.

A paper gripper is also provided on the surface of the paper transport drum 210, and the tip of the paper is gripped by the paper gripper. Further, a plurality of suction holes are dispersedly formed on the surface of the paper transport drum 210, and a suction device 211 generates a suction airflow toward the inside of the paper transport drum 210 in each suction hole.

The tip of the paper P delivered from the receiving cylinder 201 to the paper transport drum 210 is gripped by the paper gripper and is attracted to the surface of the paper transport drum 210 by the suction airflow, and the paper P is attracted to the surface of the paper transport drum 210 as the surface of the paper transport drum 210 moves. Is transported.

The ink ejection unit 220 of the present embodiment ejects four colors of ink, C (cyan), M (magenta), Y (yellow), and K (black), to form an image, and each ink is individually ejected. The liquid discharge heads 220C, 220M, 220Y, 220K of the above are provided.

The liquid discharge heads 220C, 220M, 220Y, 220K are not limited in their configuration as long as they discharge liquid, and any configuration can be adopted. If necessary, a liquid ejection head that ejects a special ink such as white, gold, or silver may be provided, or a liquid ejection head that ejects a liquid that does not form an image, such as a surface coating liquid, may be provided.

The liquid ejection heads 220C, 220M, 220Y, 220K of the ink ejection unit 220 are respectively controlled to eject by a drive signal corresponding to the image information. When the paper P conveyed by the paper transfer drum 210 passes through the area facing the ink ejection unit 220, each color ink is ejected from the liquid ejection heads 220C, 220M, 220Y, 220K, and an image corresponding to the image information is displayed. It is formed.

In the present embodiment, the image forming unit 200 is not limited in its configuration as long as it forms an image by adhering a liquid on the paper P.

[Dry part]
The drying unit 300 mainly includes a drying mechanism 301 for drying the ink adhering on the paper P in the image forming unit 200, and a conveying mechanism 302 for conveying the paper P conveyed from the image forming unit 200. Has been done.

The paper P conveyed from the image forming unit 200 is received by the conveying mechanism 302, then conveyed so as to pass through the drying mechanism 301, and is delivered to the paper ejection unit 400. When passing through the drying mechanism 301, the ink on the paper P is subjected to a drying treatment, whereby liquids such as water in the ink evaporate, the ink adheres to the paper P, and the paper P is curled. It is suppressed.

[Paper ejection section]
The paper ejection unit 400 is mainly composed of a paper ejection tray 410 on which a plurality of sheets P are loaded. The paper P conveyed from the drying unit 300 is sequentially stacked and held on the output tray 410.

In the present embodiment, the paper ejection unit 400 is not limited in its configuration as long as it ejects the paper P.

[Other functional parts]
The inkjet recording device 1 of the present embodiment is composed of a paper feeding unit 100, an image forming unit 200, a drying unit 300, and a paper ejection unit 400, but other functional units may be added as appropriate. For example, after adding a pre-processing unit that performs pre-processing of image formation between the paper feeding unit 100 and the image forming unit 200, or after performing post-processing of image formation between the drying unit 300 and the paper discharging unit 400. A processing unit can be added.

Examples of the pretreatment unit include a treatment liquid coating process for applying a treatment liquid to the paper P to react with the ink to suppress bleeding, but the content of the pretreatment is not particularly limited. ..

Further, as the post-processing unit, for example, a paper reversal transfer process for reversing the paper on which the image is formed by the image forming unit 200 and sending it to the image forming unit 200 again to form an image on both sides of the paper, or an image The process of binding a plurality of sheets of paper on which the above is formed can be mentioned, but the content of the post-processing is not particularly limited.

In the present embodiment, the device that discharges the liquid is described by using an example of an inkjet recording device, but the “device that discharges the liquid” is a liquid discharge device that discharges the liquid toward the surface to be dried of the sheet material. The head is not limited to the one provided with a head and a significant image such as a character or a figure is visualized by the discharged liquid, and for example, a pattern having no meaning in itself is also included.

The material of the sheet material is not limited, and any material such as paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics, etc., to which a liquid can adhere even temporarily may be used, for example. It may be used for film products, cloth products for clothing, building materials such as wallpaper and flooring, and leather products. In the present embodiment, a medium to which a liquid can adhere even temporarily is referred to as a "medium".

Further, the "device for discharging the liquid" can include means for feeding, transporting, and discharging paper to which the liquid can adhere, and also includes a pretreatment device, a posttreatment device, and the like.

The "liquid" may have a viscosity and surface tension that can be discharged from the head, and is not particularly limited, but has a viscosity of 30 mPa · s or less at room temperature, under normal pressure, or by heating or cooling. It is preferable to have.

More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, polymerizable compounds, resins, functionalizing materials such as surfactants, biocompatible materials such as DNA, amino acids and proteins, and calcium. , Solvents, suspensions, emulsions and the like containing edible materials such as natural pigments, etc., which can be used, for example, in inks for inkjets, surface treatment liquids and the like.

Further, the "device for discharging the liquid" includes, but is not limited to, a device in which the liquid discharge head and the sheet material move relative to each other. Specific examples include a serial type device that moves the liquid discharge head, a line type device that does not move the liquid discharge head, and the like.

The "liquid discharge head" is a functional component that discharges and ejects a liquid from a discharge hole (nozzle). As an energy generation source for discharging liquid, a piezoelectric actuator (laminated piezoelectric element and thin-film piezoelectric element), a thermal actuator using an electrothermal conversion element such as a heat generating resistor, and an electrostatic actuator composed of a vibrating plate and a counter electrode are discharged. Although energy generating means can be used, the discharge energy generating means to be used is not limited.

In this embodiment, a plurality of liquid discharge heads are arranged in the paper width direction (direction orthogonal to the transport direction) to form a long liquid discharge head (line head). Unless otherwise specified, "liquid discharge head" means "line head".

[Head positioning]
Next, a method of positioning the liquid discharge heads 220C, 220M, 220Y, 220K of the image forming unit 200 in the first embodiment with respect to the paper transport drum 210 as the transport member will be described.

FIG. 2 is a schematic view showing the configuration of the image forming unit 200.

As described above, the tip of the paper P that has been conveyed to the image forming unit 200 is gripped by the paper gripper 201a provided on the surface of the receiving cylinder 201, and is conveyed as the surface of the receiving cylinder 201 moves. Handed over to 210.

The paper P delivered to the paper transport drum 210 is supported on the surface of the paper transport drum 210 with the tip gripped by the paper gripper 201a on the paper transport drum 210, and is conveyed as the paper transport drum 210 rotates. Will be done.

Then, when the paper P conveyed by the paper transfer drum 210 passes through the region facing the ink ejection unit 220, each color ink is ejected from the liquid ejection heads 220C, 220M, 220Y, 220K, and an image corresponding to the image information is displayed. It is formed.

Each of the liquid discharge heads 220C, 220M, 220Y, 220K of the present embodiment is a line-type liquid discharge head having a length (length in the main scanning direction) over the width direction of the paper P, and each liquid with respect to the paper P. Ink is ejected from the ejection heads 220C, 220M, 220Y, 220K.

In the present embodiment, the liquid discharge heads 220C, 220M, 220Y, and 220K are individually arranged radially around the rotation axis of the paper transport drum 210. At this time, if the accuracy of the relative positional relationship between the liquid ejection heads is poor, the relative adhesion position accuracy of each color ink ejected from each liquid ejection head to the paper P deteriorates, and problems such as color misalignment occur. do.

The relative positional relationship between the liquid discharge heads referred to here is the position in the main scanning direction, the position in the sub-scanning direction, the distance from the surface of the paper transport drum 210, and the parallel to the rotation axis of the paper transport drum 210. Degree etc. are included.

In the present embodiment, the liquid discharge heads 220C, 220M, 220Y, 220K are positioned with respect to the paper transport drum 210 as follows to ensure the accuracy of the relative positions between the liquid discharge heads. ..

In the inkjet recording apparatus of the present embodiment, the paper transport drum 210 has a plurality of common positions at different positions in the main scanning direction (direction orthogonal to the transport direction of the paper transport drum 210; rotation axis direction of the paper transport drum 210). A positioning reference unit (positioning unit on the transport member side) is provided.

The plurality of common positioning reference portions in the present embodiment are two positioning reference holes formed side by side in the rotation axis direction of the paper transport drum 210 in each end region in the rotation axis direction on the outer peripheral surface of the paper transport drum 210. It is composed of a pair of drum-side positioning reference holes 212.

More specifically, as shown in FIG. 3, drum-side positioning reference holes 212 are provided in the vicinity of both ends of the paper transport drum 210 in the paper width direction.

The pair of drum-side positioning reference holes 212 have the openings of the pair of drum-side positioning reference holes 212 facing directly upward at the drum rotation position shown in FIG.

Further, each of the liquid discharge heads 220C, 220M, 220Y, and 220K is provided with a plurality of head-side positioning reference portions (head-side positioning portions) at different positions in the main scanning direction.

The plurality of head-side positioning reference portions in the present embodiment are arranged in the rotation axis direction of the paper transport drum 210 in each end region in the drum rotation axis direction on the nozzle plates of the liquid discharge heads 220C, 220M, 220Y, 220K. It is composed of a pair of head-side positioning reference holes 221C, 221M, 221Y, and 221K, which are composed of two positioning reference holes formed by.

More specifically, as shown in FIG. 3, the head-side positioning reference is located near both ends of the paper transport drum 210 in the paper width direction (near both ends of the liquid ejection heads 220C, 220M, 220Y, 220K in the longitudinal direction). Holes 221 are provided respectively.

In the present embodiment, when each of the liquid discharge heads 220C, 220M, 220Y, 220K is positioned with respect to the paper transport drum 210, the liquid discharge heads 220C, 220M, 220Y, 220K located on the upstream side in the rotation direction of the paper transport drum 210. The positioning process is carried out in order from the beginning.

The order in which the positioning steps of the liquid discharge heads 220C, 220M, 220Y, and 220K are performed is arbitrary, and is not limited to this embodiment.

Before performing the positioning step, each of the liquid discharge heads 220C, 220M, 220Y, 220K is temporarily held by the base member 290. The base member 290 has a through hole at a position corresponding to each head-side positioning reference hole 221.

In that state, first, as shown in FIG. 4, the pair of drum-side positioning reference holes 212 on the paper transport drum 210 have a predetermined rotation position (1) for carrying out the positioning step of the first liquid discharge head 220C. The paper transport drum 210 is rotated and stopped so as to be located at the rotation angle position (rotation angle position) (movement step).

After that, one end of the reference pin (rod-shaped member) 230 as the positioning reference member is passed through the drum-side positioning reference hole 212 on the paper transport drum 210, and the reference pin 230 is passed through the through hole of the base member 290. The other end is passed through the head-side positioning reference hole 221C on the liquid discharge head 220C.

As a result, the liquid discharge head 220C is positioned at a position regulated by the reference pin 230 fitted in the drum-side positioning reference hole 212 on the paper transport drum 210. As a result, the liquid discharge head 220C is positioned on the paper transport drum 210 at a position determined by the drum-side positioning reference hole 212 and the reference pin 230.

After that, the liquid discharge head 220C positioned in this way is fixed to the base member 290 that supports the liquid discharge head 220C (fixing step).

Next, as shown in FIG. 5, the pair of drum-side positioning reference holes 212 on the paper transport drum 210 have a predetermined rotation position (rotation angle) for carrying out the positioning step of the second liquid discharge head 220M. The paper transport drum 210 is rotated and stopped so as to be located at the position).

After that, similarly, one end of the reference pin 230 is passed through the drum-side positioning reference hole 212 on the paper transport drum 210, and the other end of the reference pin 230 is discharged while passing through the through hole of the base member 290. It is passed through the head-side positioning reference hole 221M on the head 220M.

As a result, the liquid discharge head 220M is positioned on the paper transport drum 210 at a position determined by the drum-side positioning reference hole 212 and the reference pin 230. After that, the liquid discharge head 220M positioned in this way is fixed to the base member 290 that supports the liquid discharge head 220M.

By performing the above steps for the third liquid discharge head 220Y and the fourth liquid discharge head 220K, the positioning of the liquid discharge heads 220C, 220M, 220Y, 220K with respect to the paper transport drum 210 is completed.

Specifically, the main scanning direction position, the sub-scanning direction position, the distance from the surface of the paper transport drum 210, and the parallelism of the paper transport drum 210 with respect to the rotation axis of each liquid discharge head 220C, 220M, 220Y, 220K are the paper. It is determined by a common drum-side positioning reference hole 212 and a reference pin 230 on the transport drum 210.

Further, FIG. 6 is a plan view of a main part when the liquid discharge head 220C is viewed from above.
In FIG. 6, the base member 290 is omitted for the sake of explanation.

In FIG. 6, the drum-side positioning reference hole 212 is located at a position corresponding to the head-side positioning reference hole 221C. At this time, for example, by inserting the reference pin 230 from above the head-side positioning reference hole 221C, the liquid discharge head 220C is positioned with reference to the drum-side positioning reference hole 212.

Then, the liquid discharge head 220C is attached (fixed) to the base member 290, the paper transport drum 210 is rotated, and the same procedure is performed for the liquid discharge head 220M.

Although the reference pin 230 is used in this embodiment, the method is not limited to this. For example, a non-contact laser measuring device or the like may be used to align the drum-side positioning reference hole 212 and the head-side positioning reference hole 221, or the head-side positioning reference hole 221 may be visually aligned. That is, at least, as shown in FIG. 6, the effect of the present invention can be obtained as long as the drum-side positioning reference hole 212 is visible through the head-side positioning reference hole 221.

That is, in the method of attaching the plurality of liquid discharge heads in the present embodiment, the drum side positioning reference hole 212 (conveying member side positioning portion) provided in the paper transport drum 210 (conveying member) for transporting the paper P (medium) is provided. , A moving step for moving the liquid discharge head 220C, 220M, 220Y, 220K to a position corresponding to the head-side positioning reference hole 221 (head-side positioning portion), and a drum-side positioning reference for the reference pin 230 (rod-shaped member). It has a fixing step of fitting the hole 212 and the head-side positioning reference hole 221 for positioning and fixing the liquid discharge heads 220C, 220M, 220Y, 220K to the apparatus main body (base member 290 in this embodiment). The moving step and the fixing step are performed on the liquid discharge heads 220C, 220M, 220Y, and 220K, respectively.

That is, the device for ejecting the liquid in the present embodiment includes a paper conveying drum 210 (conveying member) for conveying the paper P (medium) and a plurality of liquid ejection heads arranged side by side in the conveying direction of the paper P. It has 220C, 220M, 220Y, and 220K, and each liquid discharge head is provided with a head-side positioning reference hole 221 (head-side positioning portion), and the paper transport drum 210 is provided with a drum-side positioning reference hole 212. (Conveying member side positioning unit) is provided, and the drum side positioning reference hole 212 and the head side positioning reference hole 221 are positioning units for determining the positional relationship between the liquid discharge heads 220C, 220M, 220Y, 220K and the paper transport drum 210. The drum-side positioning reference hole 212 is characterized in that the paper transport drum 210 moves in the transport direction to correspond to each of the plurality of head-side positioning reference holes 221.

The "positional relationship" refers to the relative positions, intervals, postures, angles, etc. of the plurality of liquid ejection heads 220 and the paper transport drum 210. More specifically, intervals in the conveying direction of the liquid discharge head 220 to each other, the position in the sheet width direction, the parallelism of the distance between the surface of the liquid ejection head 220 and the paper conveyance drum 210, the sheet transport drum 210 of the liquid discharge head 220 Includes, but is not limited to, parallelism to the axis of rotation of. The "positioning unit for determining the positional relationship" is a mark, mark, dent, hole, groove, through hole, notch, sensor, etc. that is referred to (used) when determining at least one of the above. It may be contact type or non-contact type.

Further, "the transport member side positioning portion corresponds to the head side positioning portion" does not necessarily mean that "the transport member side positioning portion is located below the head side positioning portion". In order to determine the positional relationship between the liquid discharge head 220 and the paper transport drum 210, it is sufficient that each positioning portion can be referred to (used).

Next, the second embodiment will be described with reference to FIG.
FIG. 7 is a description showing a shape example of a pair of head-side positioning reference holes 221 provided in each liquid discharge head 220C, 220M, 220Y, 220K and a pair of drum-side positioning reference holes 212 provided on the paper transport drum 210. It is a figure.

In the present embodiment, the pair of head-side positioning reference holes 221 provided in the respective liquid discharge heads 220C, 220M, 220Y, and 220K each have a shape dimension that matches the outer diameter shape of the reference pin 230, and the reference pin 230. Is configured to fit in.

On the other hand, the pair of drum-side positioning reference holes 212 on the paper transport drum 210 have a shape and dimension that matches the outer diameter shape of the reference pin 230, and the reference pin 230 is fitted into the pair of drum-side positioning reference holes 212a. However, the other drum-side positioning reference hole 212b has a long hole shape that is long in the main scanning direction so that the reference pin 230 inserted therein can move in the main scanning direction.

As a result, even if the positions of the pair of head-side positioning reference holes 221 provided in the liquid discharge heads 220C, 220M, 220Y, and 220K vary in the main scanning direction, the drum-side positioning reference holes 212a on the paper transport drum 210 can be formed. With the drum-side positioning reference hole 212b as the main reference, the head-side positioning reference hole 221 on the liquid discharge heads 220C, 220M, 220Y, 220K is provided with respect to the drum-side positioning reference hole 212 on the paper transport drum 210. Can be positioned.

The same applies to the configuration as shown in FIG. That is, the pair of drum-side positioning reference holes 212 on the paper transport drum 210 have a shape dimension that matches the outer diameter shape of the reference pin 230, and the reference pin 230 is fitted into the pair of drum-side positioning reference holes 212. On the other hand, the pair of head-side positioning reference holes 221 provided in the respective liquid discharge heads 220C, 220M, 220Y, and 220K have one head-side positioning reference hole 221a having a shape and dimension matching the outer diameter shape of the reference pin 230. , The reference pin 230 is fitted, but the other head-side positioning reference hole 221b is long in the main scanning direction so that the reference pin 230 inserted therein can move in the main scanning direction. It has an elongated hole shape.

Even with such a configuration, even if the positions of the pair of head-side positioning reference holes 221 provided in the liquid discharge heads 220C, 220M, 220Y, 220K vary in the main scanning direction, the liquid discharge heads 220C, 220M, 220Y, With the head-side positioning reference hole 221a on 220K as the main reference and the head-side positioning reference hole 221b as the secondary reference, the head-side positioning reference hole 221 on the liquid discharge heads 220C, 220M, 220Y, 220K is placed on the paper transport drum 210. Can be positioned with respect to the drum side positioning reference hole 212.

Further, as shown in FIG. 9, the same effect can be exhibited when the notch 212c is used instead of the long hole-shaped drum side positioning reference hole 212b.

Further, in any of the embodiments, the drum-side positioning reference hole 212 may be a through hole or a non-penetrating groove (recess), and may have a shape in which a rod-shaped reference pin 230 can be inserted.

Further, in any of the embodiments, the head-side positioning reference hole 221 may be a through hole or a non-penetrating groove (recess). However, the head-side positioning reference hole 221 is preferably a through hole so that the drum-side positioning reference hole 212 of the paper transport drum 210 can be visually recognized from above the liquid discharge heads 220C, 220M, 220Y, 220K. In this case, workability is improved.

Further, in any of the embodiments, the rod-shaped reference pin 230 is not essential for positioning. For example, a measuring device using a laser light source is irradiated from the head-side positioning reference hole 221 (light passing portion) to reach the drum-side positioning reference hole 212, and the liquid ejection heads 220C, 220M, 220Y, 220K and the paper transport drum are reached. Positioning can also be performed by measuring the relative position of 210. Positioning is also possible by various other methods.

Examples of the light passing portion include through holes, glass, film, mirrors, and the like, and any method may be used as long as the structure can finally determine the positional relationship. When a mirror is used, the irradiation position of the laser light source can be freely changed.

In the present embodiment, the head-side positioning reference holes 221C, 221M, 221Y, and 221K provided in the respective liquid discharge heads 220C, 220M, 220Y, and 220K are all common drum-side positioning reference holes on the paper transport drum 210. Positioned relative to 212.

In the conventional configuration in which individual drum-side positioning reference holes are provided on the paper transport drum 210 for each of the liquid discharge heads 220C, 220M, 220Y, and 220K, the position accuracy between the drum-side positioning reference holes for each liquid discharge head is liquid. It affects the relative position accuracy between the discharge heads.

According to the present embodiment, the head-side positioning reference holes 221C, 221M, 221Y, and 221K of each liquid discharge head are all positioned with respect to the common drum-side positioning reference hole 212 on the paper transport drum 210. As in the conventional configuration, the position accuracy between the drum-side positioning reference holes for each liquid discharge head does not affect the relative position accuracy between the liquid discharge heads.

Therefore, in the present embodiment, even if the position accuracy and processing accuracy of the pair of drum-side positioning reference holes 212 provided on the paper transport drum 210 are poor, the relative position accuracy between the liquid ejection heads can be obtained. It is easy to obtain the relative adhesion position accuracy of the ink ejected from each liquid ejection head.

For example, when the direction connecting the positions of the pair of drum-side positioning reference holes 212 provided on the paper transport drum 210 deviates from the rotation axis direction of the paper transport drum 210, each liquid with respect to the rotation axis of the paper transport drum 210. Although the parallelism of the discharge heads is deviated, the relative parallelism between the liquid discharge heads does not deviate.

In this case, the ink adhesion position where each color ink ejected from each liquid ejection head adheres to the paper P may deviate from the target position, and although some image distortion may occur, each color ejected from each liquid ejection head Since the relative positions of the inks do not shift, it is possible to prevent color shift, which is more remarkable deterioration in image quality than image distortion.

The above description is an example, and the effect peculiar to each of the following aspects is exhibited.

(Aspect A)
A device for discharging a liquid having a transport member for transporting a medium and a plurality of liquid discharge heads arranged side by side in the transport direction of the medium, and the plurality of liquid discharge heads are positioned on the head side. Each unit is provided, and the transport member is provided with a transport member-side positioning portion, and the head-side positioning portion and the transport member-side positioning portion are used to determine the positional relationship between the liquid discharge head and the transport member. It is a positioning unit, and the transport member-side positioning portion is characterized in that the transport member moves in the transport direction to correspond to each of a plurality of head-side positioning portions.

According to this aspect, each liquid discharge head is positioned with respect to the transport member by positioning the head-side positioning portion provided on each liquid discharge head with respect to the transport member-side positioning portion provided on the transport member.

Therefore, as compared with the conventional case where the head-side positioning portion provided on each liquid discharge head is positioned with respect to the individual positioning portion for each liquid discharge head provided on the transport member, the head-side positioning portion is provided on the transport member. The position accuracy between the positioning portions of each liquid discharge head does not affect the relative position accuracy between the liquid discharge heads.

Moreover, since the number of the transport member-side positioning portions provided on the transport member is smaller than that in the case where the transport member is provided with individual positioning portions for each liquid discharge head as in the conventional case, the positioning portion having high positioning accuracy is provided on the transport member. Can be provided relatively easily. Therefore, it is easy to obtain the relative position accuracy between the liquid discharge heads (position accuracy with respect to the conveying member), and it is easy to obtain the relative adhesion position accuracy of the liquid discharged from each liquid discharge head.

The relative position accuracy between the liquid discharge heads (positional accuracy with respect to the transport member) as used herein means that the head-side positioning portion provided on each liquid discharge head is positioned with respect to the transport member-side positioning portion provided on the transport member. If the accuracy of the position is as long as it is, the position in the main scanning direction, the position in the sub-scanning direction, the distance from the surface of the conveying member, the parallelism to the surface of the conveying member, and the conveying direction of the conveying member are orthogonal to each other. Positional accuracy regarding parallelism with respect to the direction is included.

For example, the position in the main scanning direction between the liquid discharge heads, the distance from the surface of the transport member, and the parallelism with respect to the surface of the transport member are common positioning portions among the liquid discharge heads, which are the transport member side positioning portions provided on the transport member. High positioning accuracy can be obtained by positioning with respect to.

Further, for example, regarding the position in the sub-scanning direction between the liquid discharge heads and the parallelism with respect to the direction orthogonal to the transport direction of the transport member, the transport position of the transport member is controlled with high accuracy and is common among the liquid discharge heads. High positioning accuracy can be obtained by positioning with respect to the positioning portion on the transport member side.

As a result, when the relative adhesion position accuracy of the liquid discharged from each liquid discharge head deteriorates, the relative position accuracy between the liquid discharge heads (position accuracy with respect to the transport member) is adjusted to adjust each liquid. A device that discharges a liquid that can improve the relative adhesion position accuracy of the liquid discharged from the discharge head is realized.

(Aspect B)
In the aspect A, the transport member is a cylindrical transport drum, and the transport member-side positioning portion corresponds to each of a plurality of head-side positioning portions by rotating the transport drum. do.
According to this, in a device for discharging liquid from a plurality of liquid discharge heads to a medium supported on the surface of a drum-shaped member, it is easy to obtain relative adhesion position accuracy of the liquid discharged from each liquid discharge head. ..

(Aspect C)
In the aspect A or B, at least one of the transport member-side positioning portion and the head-side positioning portion is a long hole or notch in a direction orthogonal to the transport direction.

According to this, even if there are variations in the main scanning direction positions of the plurality of head-side positioning portions provided on each liquid discharge head, positioning can be performed with respect to the transport member-side positioning portions on the transport member.

(Aspect D)
In any of the embodiments A to C, when the head-side positioning portion is a through hole and the transport member-side positioning portion is at a position corresponding to the through hole, the rod-shaped member passes through the through hole. It is characterized in that it can be fitted to the positioning portion on the transport member side.
According to this, it is possible to improve the relative positional accuracy between the liquid discharge heads by a simple operation using the rod-shaped member.

(Aspect E)
In any of the embodiments A to C, when the head-side positioning portion is a light passing portion through which light can pass and the transport member-side positioning portion is at a position corresponding to the light passing portion, the light It is characterized in that the light can reach the positioning portion on the transport member side through the passing portion.
According to this, the liquid discharge head can be positioned by using laser light, visual inspection, or the like.

(Aspect F)
A method of attaching a plurality of liquid discharge heads for discharging liquid to a medium, in which a transport member-side positioning portion provided on the transport member for transporting the medium corresponds to a head-side positioning portion provided on the liquid discharge head. It has a moving step of moving the rod-shaped member to the position to be moved, and a fixing step of fitting the rod-shaped member to the transport member-side positioning portion and the head-side positioning portion to perform positioning and fixing the liquid discharge head to the apparatus main body. , The moving step and the fixing step are performed for each of the plurality of liquid discharge heads.

According to this aspect, each liquid discharge head is positioned with respect to the transport member by positioning the head-side positioning portion provided on each liquid discharge head with respect to the transport member-side positioning portion provided on the transport member.

Therefore, as compared with the conventional case where the head-side positioning portion provided on each liquid discharge head is positioned with respect to the individual positioning portion for each liquid discharge head provided on the transport member, the head-side positioning portion is provided on the transport member. The position accuracy between the positioning portions of each liquid discharge head does not affect the relative position accuracy between the liquid discharge heads.

Moreover, since the number of the transport member-side positioning portions provided on the transport member is smaller than that in the case where the transport member is provided with individual positioning portions for each liquid discharge head as in the conventional case, the positioning portion having high positioning accuracy is provided on the transport member. Can be provided relatively easily. Therefore, it is easy to obtain the relative position accuracy between the liquid discharge heads (position accuracy with respect to the conveying member), and it is easy to obtain the relative adhesion position accuracy of the liquid discharged from each liquid discharge head.

The relative position accuracy between the liquid discharge heads (positional accuracy with respect to the transport member) as used herein means that the head-side positioning portion provided on each liquid discharge head is positioned with respect to the transport member-side positioning portion provided on the transport member. If the accuracy of the position is as long as it is, the position in the main scanning direction, the position in the sub-scanning direction, the distance from the surface of the conveying member, the parallelism to the surface of the conveying member, and the conveying direction of the conveying member are orthogonal to each other. Positional accuracy regarding parallelism with respect to the direction is included.

For example, the position in the main scanning direction between the liquid discharge heads, the distance from the surface of the transport member, and the parallelism with respect to the surface of the transport member are common positioning portions among the liquid discharge heads, which are the transport member side positioning portions provided on the transport member. High positioning accuracy can be obtained by positioning with respect to.

Further, for example, regarding the position in the sub-scanning direction between the liquid discharge heads and the parallelism with respect to the direction orthogonal to the transport direction of the transport member, the transport position of the transport member is controlled with high accuracy and is common among the liquid discharge heads. High positioning accuracy can be obtained by positioning with respect to the positioning portion on the transport member side.

(Aspect G)
A method of attaching a plurality of liquid discharge heads for discharging liquid to a medium, in which a transport member-side positioning portion provided on the transport member for transporting the medium corresponds to a head-side positioning portion provided on the liquid discharge head. It has a moving step for moving the liquid to a position to be moved, and a fixing step for fixing the liquid discharge head to the apparatus main body by positioning the transport member side positioning portion and the head side positioning portion in association with each other using a laser. , The moving step and the fixing step are performed on each of the plurality of liquid discharge heads.
Similar to the above aspect F, it is easy to obtain the relative position accuracy between the liquid discharge heads (position accuracy with respect to the conveying member), and it is easy to obtain the relative adhesion position accuracy of the liquid discharged from each liquid discharge head.

(Aspect H)
A method for manufacturing a device for discharging a liquid is characterized in that a method for attaching a plurality of liquid discharge heads according to the aspect F or G is used.
According to this, it is easy to obtain the relative position accuracy between the liquid discharge heads (position accuracy with respect to the conveying member), and it is easy to obtain the relative adhesion position accuracy of the liquid discharged from each liquid discharge head. It is possible to manufacture a device that discharges a liquid having a high relative accuracy of the adhesion position of the liquid discharged from the head.

1 Inkjet recording device 200 Image forming unit 201 Receiving cylinder 201a Paper gripper 202 Delivery cylinder 210 Paper transport drum 210a Paper gripper 211 Suction device 212 Drum side positioning reference hole 220 Ink ejection unit 220C, 220M, 220Y, 220K Liquid ejection head 221C, 221M , 221Y, 221K Head side positioning reference hole 230 Reference pin 290 Base member

Japanese Unexamined Patent Publication No. 2010-173305

Claims (11)

A transport member that transports the medium and
A device for discharging a liquid having a plurality of liquid discharge heads arranged side by side in the transport direction of the medium.
Each of the plurality of liquid discharge heads is provided with a head-side positioning portion.
The transport member is provided with a transport member side positioning portion.
The head-side positioning unit and the transfer member-side positioning unit are positioning units for determining the positional relationship between the liquid discharge head and the transfer member.
The transport member-side positioning unit is a device for discharging a liquid, characterized in that the transport member moves in the transport direction to come into contact with each of the plurality of head-side positioning portions to determine the positional relationship. An apparatus for discharging liquid according to 請Motomeko 1,
The head-side positioning portion is a through hole.
A device for discharging a liquid, characterized in that a rod-shaped member can be fitted into the transport member side positioning portion through the through hole when the transport member side positioning portion is located at a position corresponding to the through hole. A transport member that transports the medium and
A device for discharging a liquid having a plurality of liquid discharge heads arranged side by side in the transport direction of the medium.
Each of the plurality of liquid discharge heads is provided with a head-side positioning portion.
The transport member is provided with a transport member side positioning portion.
The head-side positioning unit and the transfer member-side positioning unit are positioning units for determining the positional relationship between the liquid discharge head and the transfer member.
The transport member-side positioning unit corresponds to each of the plurality of head-side positioning portions by moving the transport member in the transport direction.
The head-side positioning portion is a through hole.
A device for discharging a liquid, characterized in that a rod-shaped member can be fitted into the transport member side positioning portion through the through hole when the transport member side positioning portion is located at a position corresponding to the through hole. In the device for discharging the liquid according to any one of claims 1 to 3.
A device for discharging a liquid, wherein at least one of the transport member-side positioning portion and the head-side positioning portion is a long hole or notch in a direction orthogonal to the transport direction. A transport member that transports the medium and
A device for discharging a liquid having a plurality of liquid discharge heads arranged side by side in the transport direction of the medium.
Each of the plurality of liquid discharge heads is provided with a head-side positioning portion.
The transport member is provided with a transport member side positioning portion.
The head-side positioning unit and the transfer member-side positioning unit are positioning units for determining the positional relationship between the liquid discharge head and the transfer member.
The transport member-side positioning unit corresponds to each of the plurality of head-side positioning portions by moving the transport member in the transport direction.
A device for discharging a liquid, wherein at least one of the transport member-side positioning portion and the head-side positioning portion is a long hole or notch in a direction orthogonal to the transport direction. In the device for discharging the liquid according to claim 5.
The head-side positioning portion is a light passing portion through which light can pass.
A device for discharging a liquid, characterized in that, when the transport member-side positioning portion is at a position corresponding to the light passing portion, the light can reach the transport member-side positioning portion through the light passing portion. A transport member that transports the medium and
A device for discharging a liquid having a plurality of liquid discharge heads arranged side by side in the transport direction of the medium.
Each of the plurality of liquid discharge heads is provided with a head-side positioning portion.
The transport member is provided with a transport member side positioning portion.
The head-side positioning unit and the transfer member-side positioning unit are positioning units for determining the positional relationship between the liquid discharge head and the transfer member.
The transport member-side positioning unit corresponds to each of the plurality of head-side positioning portions by moving the transport member in the transport direction.
The head-side positioning portion is a light passing portion through which light can pass.
A device for discharging a liquid, characterized in that, when the transport member-side positioning portion is at a position corresponding to the light passing portion, the light can reach the transport member-side positioning portion through the light passing portion. In the device for discharging the liquid according to any one of claims 1 to 7.
The transport member is a cylindrical transport drum.
The transport member-side positioning unit is a device for discharging a liquid, which corresponds to each of a plurality of head-side positioning units by rotating the transport drum. It is a method of attaching a plurality of liquid discharge heads that discharge liquid to a medium.
A moving step of moving the transport member-side positioning portion provided on the transport member for transporting the medium to a position corresponding to the head-side positioning portion provided on the liquid discharge head.
It has a fixing step of fitting the rod-shaped member to the transport member side positioning portion and the head side positioning portion to perform positioning and fixing the liquid discharge head to the apparatus main body.
A method for attaching a plurality of liquid discharge heads, wherein the moving step and the fixing step are performed on each of the plurality of liquid discharge heads. It is a method of attaching a plurality of liquid discharge heads that discharge liquid to a medium.
A moving step of moving the transport member-side positioning portion provided on the transport member for transporting the medium to a position corresponding to the head-side positioning portion provided on the liquid discharge head.
It has a fixing step of fixing the liquid discharge head to the apparatus main body by positioning the transport member side positioning portion and the head side positioning portion in association with each other using a laser.
A method for attaching a plurality of liquid discharge heads, wherein the moving step and the fixing step are performed on each of the plurality of liquid discharge heads. The method according to claim 9 or apparatus for ejecting liquid, which comprises using a plurality of mounting method of a liquid discharge head according to 10.

Images