JP7494616B2 - HEAD UNIT AND DEVICE FOR EJECTING LIQUID - Google Patents

Description

The present invention relates to a head unit and a device for ejecting liquid.

As image forming devices such as printers, facsimiles, copiers, plotters, and combination machines thereof, devices that eject liquid using a recording head consisting of a liquid ejection head (droplet ejection head) that ejects ink droplets, such as inkjet recording devices, are known.

In a line-type head unit (head array) in which a plurality of heads are arranged in one line, the position of each head needs to be determined with high accuracy.
Because the positioning process is complicated, there is a demand for a head unit that can align multiple heads efficiently and with high precision using a simple configuration.

In response to this, Patent Document 1 proposes a head unit in which a head is held by a first plate member, the first plate member is held by a second plate member, the first plate member is rotatable relative to the second plate member in a direction perpendicular to the nozzle surface of the head and about the Z axis passing through the center position of a specific nozzle of the head, and the second plate member is movable relative to the array base member in the X axis direction, which is the nozzle arrangement direction, parallel to the nozzle surface of the head, and the first plate member and the second plate member are in contact via an arc-shaped contact portion centered on the center position of a specific nozzle.

However, the head unit configuration of Patent Document 1 has a problem in that the number of parts is extremely large.
On the other hand, it is possible to eliminate the adjustment mechanism altogether by improving the precision of each individual component, but this would make it difficult to reduce the labor and costs involved in component design, and would also increase the labor required to adjust the head position, making it more complicated.

However, when the head is set into the holder, the reference surface on the holder side is brought into contact with the reference surface on the head side while being set, so that the reference surface can be worn down by friction, and there is a risk that the position of the head will shift each time it is set.
In response to this, it is possible to provide a release mechanism that releases the pressure on the reference surface when the head is set, but this would result in an increase in the number of parts and an increase in the size of the member that includes the holding portion.

The present invention aims to provide a head unit that can reduce the number of components without increasing the size, reduce the labor hours for component design and head position adjustment, and reduce costs, and ensure head position accuracy even when the head is repeatedly attached and detached.

In order to solve the above problems, the head unit of the present invention is a head unit comprising a head that ejects droplets and a holding portion that holds the head, wherein the holding portion comprises an engagement portion that engages the head and a pressing means that presses the head toward the engagement portion, wherein the engagement portion has a holding portion side reference surface that abuts against a head side reference surface of the head to regulate the position of the head, and a convex portion that protrudes toward the head side beyond the holding portion side reference surface, wherein the engagement portion has a plurality of the convex portions, and the holding portion side reference surface is positioned between the plurality of the convex portions in a direction perpendicular to the mounting direction of the head and the pressing direction of the pressing means .

The present invention provides a head unit that can reduce the number of components without increasing size, reduce the labor required for component design and head position adjustment, and reduce costs, while ensuring head position accuracy even when the head is repeatedly attached and detached.

FIG. 1 is a schematic explanatory diagram of a printing apparatus as an example of an apparatus that ejects liquid. FIG. 2 is a plan view illustrating an example of a head unit. FIG. 2 is a schematic perspective view of a head unit with one head attached. FIG. 2 is a schematic plan view of a head unit with one head attached. FIG. 4 is an enlarged view of the head portion of FIG. 3 . FIG. 2 is a side view of the head unit with one head attached. FIG. 2 is a side view including a reference surface of the head. FIG. 4 is an explanatory diagram showing a reference surface of a head. 5A and 5B are a schematic perspective view and a side view showing an example of an engagement portion of a holding portion. 10A to 10C are side views illustrating a process of mounting the head on a holder. 11 is a schematic perspective view showing an example of an engagement portion of the holding portion. FIG. 11A to 11C are side views illustrating a part of the process of mounting the head on the holder. 10A to 10C are side views illustrating a process of mounting the head on the holder. 13 is a side view illustrating an inclined portion of the engagement portion of the holding portion. FIG. 11 is a schematic perspective view showing an example of an engagement portion of the holding portion. FIG.

The head unit and liquid ejection device according to the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the embodiments shown below, and can be modified within the scope of what a person skilled in the art can imagine, including other embodiments, additions, modifications, deletions, etc., and any aspect is within the scope of the present invention as long as it achieves the functions and effects of the present invention.

[Liquid ejection device]
First, an example of a liquid ejecting device including a head unit according to the present invention will be described with reference to FIGS. 1 and 2. FIG.
FIG. 1 is a schematic explanatory diagram of a device for discharging liquid, and FIG. 2 is a plan explanatory diagram of an example of a head unit of the device.

The printing device 500, which is one embodiment of a device for ejecting liquid, includes an input means 501 for inputting a continuous body 510, a guide and conveyance means 503 for guiding and conveying the continuous body 510, such as continuous paper or sheet material, inputted from the input means 501, to a printing means 505, a printing means 505 for ejecting liquid onto the continuous body 510 to perform printing to form an image, a drying means 507 for drying the continuous body 510, and an ejection means 509 for ejecting the continuous body 510.

The continuous body 510 is sent out from the original winding roller 511 of the carrying-in means 501, guided and transported by the rollers of the carrying-in means 501, the guide and transport means 503, the drying means 507, and the carrying-out means 509, and then wound up by the winding roller 591 of the carrying-out means 509.

This continuous body 510 is transported on the transport guide member 559 in the printing means 505, facing the head unit 550 and the head unit 555, an image is formed by the liquid ejected from the head unit 550, and post-processing is performed with the processing liquid ejected from the head unit 555.

Here, the head unit 550 according to the present invention has, for example, full-line head arrays 551A, 551B, 551C, and 551D (hereinafter, when no distinction is made between colors, they will be referred to as "head array 551") arranged for four colors from the upstream side in the transport direction.

Each head array 551 is a liquid ejection means, and ejects black K, cyan C, magenta M, and yellow Y liquid onto the transported continuum 510. Note that the types and number of colors are not limited to these.

The head array 551 constituting the head unit 550 is, for example, a staggered arrangement of heads (liquid ejection heads) 2 on the holding portion 1, but is not limited to this.

[Head unit]
One embodiment of a head unit 550 according to the present invention is shown in Fig. 3 to Fig. 6. Fig. 3 is a schematic perspective view of a state in which one head 2 is attached to a holding portion 1, Fig. 4 is a schematic plan view thereof, and Fig. 6 is a side view (cross-sectional view) thereof. Fig. 5 is an enlarged view of the head portion of Fig. 4.
7 shows a side view of the head 2 mounted on the holder 1, and FIG. 8 shows a partially enlarged view of the head-side reference surface.
9 shows an embodiment of the engagement portion 11 provided in the holding portion 1. Fig. 9(A) is a perspective view of the engagement portion 11, and Fig. 9(B) is a side view seen from a direction perpendicular to the mounting direction D1 of the head 2 and the pressing direction D2 of the pressing means 12.

The head unit of this embodiment is a head unit 550 comprising a head 2 that ejects droplets and a holding portion 1 that holds the head 2, and the holding portion 1 comprises an engagement portion 11 that engages the head 2 and a pressing means 12 that presses the head 2 towards the engagement portion 11, and the engagement portion 11 has a holding portion side reference surface 13 that abuts against a head side reference surface 20 of the head 2 to regulate the position of the head 2, and a convex portion 14 that protrudes toward the head 2 side beyond the holding portion side reference surface 13.
Furthermore, the head unit 550 of this embodiment may be configured in such a way that a plurality of heads 2 and a plurality of holders 1 are provided.

It is preferable that a plurality of engaging portions 11 and pressing means are provided in the recess 10 of the holding portion 1 that holds the head 2 .
For example, as shown in FIG. 5, a preferred embodiment has three pressing means 12 corresponding to three engagement portions 11 for one recess 10. In the embodiment shown in FIG.
The pressing means 12 presses the head 2 in a direction perpendicular to the mounting direction of the head 2 .
The pressing means 12 is not particularly limited as long as it can bias the head 2, and examples thereof include a spring.

(First embodiment)
FIG. 10 shows the process of mounting the head 2 to the holder 1 in the head unit of the first embodiment.
FIG. 10 is a side view seen from a direction perpendicular to the mounting direction D1 of the head 2 and the pressing direction D2 of the pressing means 12. FIG.
FIG. 10A shows the state immediately before the head 2 is attached to the holder of the holder 1. FIG.
10B and 10C show the state in which the head side reference surface 20 (sliding portion 21) and the convex portion 14 are in contact with each other in the process of engaging the head 2 with the engaging portion 11 of the holding portion 1 in this order.
10D shows a state in which the head 2 is hooked onto and engaged with the engagement portion 11 (a state in which the head 2 is attached to the holding portion of the holding portion 1). In this state, the holding portion side reference surface 13 and the head side reference surface 20 are in contact with each other.

As shown in Figures 10(B) and 10(C), when the head 2 is set in the holder 1, it is set while the convex portion 14 and the head side reference surface 20 are in contact with each other. In addition, the head 2 is pressed toward the engagement portion 11 of the holder 1 by the pressing means 12, so that the sliding portion 21 of the head side reference surface 20 is scraped off by rubbing against the convex portion 14 every time the head is set.

However, in the head unit of this embodiment, even if the rubbing portion 21 of the head side reference surface 20 of the head 2 shown in FIG. 8 is worn away by rubbing against the convex portion 14 of the engagement portion 11 shown in FIG. 9, the non-rubbing portion 22 of the head side reference surface 20 of the head 2 shown in FIG. 8 does not come into contact with the convex portion 14 and remains without being worn away. Therefore, position adjustment is achieved by the abutment of the undamaged non-rubbing portion 22 of the head side reference surface 20 with the retaining portion side reference surface 13.

As shown in FIG. 9, it is preferable that the retainer side reference surface 13 of the engagement portion 11 is longer in the mounting direction D1 of the head 2 than the protrusion 14. This allows for reliable contact with the head side reference surface 20, allowing the position of the head 2 to be adjusted with high precision.

Also, as shown in Figure 9, it is preferable that the engagement portion 11 has a plurality of convex portions 14, and the holding portion side reference surface 13 is positioned between the plurality of convex portions 14 in a direction perpendicular to the mounting direction of the head 2 and the pressing direction of the pressing means 12.
With this configuration, the holder-side reference surface 13 can be reliably protected from damage.

Furthermore, as shown in Figure 9 (B), the convex portion 14 of the engagement portion 11 has an inclined portion 14 that inclines from the top end surface 15 that protrudes most toward the head 2 toward the holding portion side reference surface 13, and it is preferable that the holding portion side reference surface 13 is located closer to the top end surface 15 than the base 14c of the inclined portion when viewed from a direction perpendicular to the mounting direction D1 of the head 2 and the pressing direction D2 of the pressing means 12.
With this configuration, the movement of the contact position from the convex portion 14 of the head side reference surface 20 to the holder side reference surface can be realized smoothly and reliably.

With the above-mentioned configuration, even if the head 2 is repeatedly detached from the holder 1 during maintenance or replacement of the head 2, the non-sliding portion 22 of the head-side reference surface 20 is not damaged.
The holding part 1 is not replaced throughout the life of the main body of the device that ejects the liquid, and the convex part 14 is rubbed repeatedly each time the head 2 is attached or detached, but the holding part side reference surface 13, which is involved in adjusting the position, is not rubbed against the head 2 and is not damaged.

The head unit 550 of this embodiment can prevent damage without providing a release mechanism or the like for releasing the pressure contact between the holder side reference surface 13 and the head side reference surface 20 when the head 2 is set.
Furthermore, the head unit 550 of this embodiment reduces the number of components without increasing the size, reducing the labor required for component design and the labor required for adjusting the position of the head 2, as well as the cost, and can ensure the positional accuracy of the head 2 even if the head 2 is repeatedly attached and detached.

Second Embodiment
FIG. 11 is a perspective view of an engagement portion 11 provided on a holding portion 1 of a head unit according to this embodiment.
As shown in FIG. 11, the holder side reference surface 13 is preferably provided longer than the protrusion 14 in the mounting direction of the head 2, but does not have to be formed over the entire length of the head 2 in the mounting direction.

Figure 12 shows a state in which the holding portion side reference surface 13 is formed over the entire length of the head 2 in the mounting direction, and the head side reference surface 20 (sliding portion 21) and the convex portion 14 abut in the process of engaging the head 2 with the engagement portion 11 of the holding portion 1.
In this case, as shown in FIG. 12, a part of the head 2 (the lower end portion enclosed by the dashed circle in the figure) may tilt and come into contact with the holder-side reference surface 13 .

In contrast, in this embodiment, the holder side reference surface 13 is provided only in an area that does not come into contact with the tilted head 2, thereby preventing damage to the holder side reference surface 13.

FIG. 13 shows the process of mounting the head 2 to the holder 1 in the head unit of this embodiment, and is a side view seen from a direction perpendicular to the mounting direction of the head 2 and the pressing direction of the pressing means 12.
As shown in Fig. 13(A), the head 2 is attached without contacting the holder-side reference surface 13. Fig. 13(B) shows the state in which the head 2 is attached to the holder 1, and the head 2 is hooked and engaged with the engagement portion 11. In this state, the holder-side reference surface 13 and the head-side reference surface 20 (non-sliding portion 22) come into contact with each other.

Third Embodiment
FIG. 14 shows a side view of the engagement portion 11 provided on the holder 1 of the head unit according to this embodiment.
As shown in Figure 14, the convex portion 14 of the engagement portion 11 has a first inclined portion 14a that inclines from the top end surface 15 that protrudes most toward the head 2 toward the holding portion side reference surface 13, and a second inclined portion 14b that inclines symmetrically relative to the first inclined portion 14a and the top end surface 15 when viewed from a direction perpendicular to the mounting direction D1 of the head 2 and the pressing direction D2 of the pressing means 17, and the inclination angle θ1 of the first inclined portion 14a is different from the inclination angle θ2 of the second inclined portion 14b.

Specifically, it is preferable that the inclination angle θ1 of the first inclined portion 14a is larger than the inclination angle θ2 of the second inclined portion 14b.
When the head 2 is set in the holder 1, the first inclined portion 14a has a gentle inclination, so that the head 2 easily climbs over the top end surface 15.
On the other hand, since the second inclined portion 14b has a steep inclination, immediately after the head 2 overcomes the top end surface 15, the head 2 receives pressure from the pressing means 17 and the head side reference surface 20 is pressed against the holding part side reference surface 13, thereby avoiding unnecessary contact and friction between the head side reference surface 20 and the holding part side reference surface 13 during the mounting process.

(Fourth embodiment)
FIG. 15 is a perspective view of an engagement portion 11 provided on a holder 1 of a head unit according to this embodiment.
As described above, from the standpoint of ensuring the protection of the holding portion side reference surface 13, it is preferable that the engagement portion 11 has a plurality of convex portions 14 and that the holding portion side reference surface 13 is arranged between the plurality of convex portions 14 in a direction perpendicular to the mounting direction of the head 2 and the pressing direction of the pressing means 12; however, from the standpoint of miniaturization of parts, design labor, and cost, it is also possible to have only one convex portion 14, as shown in Figure 15.

The head 2 included in the head unit 550 according to the present invention ejects liquid from a plurality of nozzles.
The liquid to be ejected may have any viscosity and surface tension that allows it to be ejected from the head, and is not particularly limited, but is preferably one whose viscosity is 30 mPa·s or less at room temperature and pressure, or by heating or cooling. More specifically, the liquid may be a solution, suspension, emulsion, etc., containing a solvent such as water or an organic solvent, a colorant such as a dye or pigment, a functionalizing material such as a polymerizable compound, a resin, or a surfactant, a biocompatible material such as DNA, an amino acid, a protein, or calcium, an edible material such as a natural dye, etc., and these can be used for applications such as inkjet ink, surface treatment liquid, a liquid for forming a component of an electronic element or a light-emitting element, an electronic circuit resist pattern, a material liquid for three-dimensional modeling, etc.

Sources of energy for ejecting liquid include piezoelectric actuators (laminated piezoelectric elements and thin-film piezoelectric elements), thermal actuators that use electrothermal conversion elements such as heating resistors, and electrostatic actuators that consist of a vibration plate and an opposing electrode.

In addition, "devices that eject liquid" include not only devices that can eject liquid onto objects to which the liquid can adhere, but also devices that eject liquid into air or liquid.

This "liquid ejecting device" can also include means for feeding, transporting, and discharging items onto which liquid can be attached, as well as pre-processing devices and post-processing devices.
For example, examples of "devices that eject liquid" include image forming devices that eject ink to form an image on paper, and three-dimensional modeling devices (three-dimensional modeling devices) that eject modeling liquid onto a powder layer formed in a layer of powder in order to create a three-dimensional object (a three-dimensional model).

In addition, a "liquid ejecting device" is not limited to devices that use ejected liquid to visualize meaningful images such as letters and figures. For example, it also includes devices that form patterns that have no meaning in themselves, and devices that create three-dimensional images.

The above phrase "something to which liquid can adhere" refers to something to which liquid can adhere at least temporarily, and to which the liquid adheres and sticks, or adheres and penetrates. Specific examples include media such as paper, recording paper, film, and cloth, electronic circuit boards, electronic components such as piezoelectric elements, powder layers, organ models, and test cells, and unless otherwise specified, includes all things to which liquid can adhere.

The above-mentioned "materials to which liquid can adhere" include paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics, and other materials to which liquid can adhere even temporarily.

In addition, the "liquid ejection device" may be a device in which a liquid ejection head and an object to which liquid can be attached move relatively, but is not limited to this. Specific examples include a serial type device in which the liquid ejection head moves, and a line type device in which the liquid ejection head does not move.

Other examples of "liquid ejecting devices" include treatment liquid application devices that eject treatment liquid onto paper to apply the treatment liquid to the surface of the paper for purposes such as modifying the surface of the paper, and spray granulation devices that spray a composition liquid in which raw materials are dispersed through a nozzle to granulate the raw material into fine particles.

In this application, the terms image formation, recording, printing, copying, printing, modeling, etc. are all synonymous.

REFERENCE SIGNS LIST 1: Holding portion 2: Head 10: Recess 11: Engagement portion 12: Pressing means 13: Holding portion side reference surface 14: Protrusion 15: Top end surface 20: Head side reference surface 21: Sliding portion 22: Non-sliding portion 550: Head unit

JP 2014-14972 A

Claims (8)

A head unit including a head that ejects droplets and a holder that holds the head,
the holding portion includes an engagement portion that engages the head, and a pressing means that presses the head toward the engagement portion,
the engaging portion has a holder-side reference surface that abuts against a head-side reference surface of the head to regulate a position of the head, and a protrusion that protrudes toward the head side beyond the holder-side reference surface,
The engaging portion has a plurality of the protruding portions,
The head unit according to claim 1, wherein the holding portion side reference surface is disposed between a plurality of the protrusions in a direction perpendicular to the mounting direction of the head and the pressing direction of the pressing means . A head unit including a head that ejects droplets and a holder that holds the head,
the holding portion includes an engagement portion that engages the head, and a pressing means that presses the head toward the engagement portion,
the engaging portion has a holder-side reference surface that abuts against a head-side reference surface of the head to regulate a position of the head, and a protrusion that protrudes toward the head side beyond the holder-side reference surface,
the protrusion of the engagement portion has an inclined portion inclined from a top end surface that protrudes most toward the head side toward the holder side reference surface,
A head unit characterized in that the holding portion side reference surface is located closer to the top end surface than the base of the inclined portion when viewed from a direction perpendicular to the mounting direction of the head and the pressing direction of the pressing means . 3. The head unit according to claim 1, wherein the retaining portion side reference surface is provided longer than the protrusion in a mounting direction of the head. 4. The head unit according to claim 1, wherein the pressing means presses the head in a direction perpendicular to a head mounting direction. The engaging portion has a plurality of the protruding portions,
3. The head unit according to claim 2 , wherein the holder side reference surface is disposed between a plurality of the protrusions in a direction perpendicular to the mounting direction of the head and the pressing direction of the pressing means. the protrusion of the engagement portion has a first inclined portion inclined from a top end surface that protrudes most toward the head side toward the holding portion side reference surface, and a second inclined portion inclined symmetrically with respect to the first inclined portion and the top end surface when viewed from a direction perpendicular to the mounting direction of the head and the pressing direction of the pressing means,
6. The head unit according to claim 1, wherein an inclination angle of the first inclined portion is different from an inclination angle of the second inclined portion. A head unit according to any one of claims 1 to 6, characterized in that it comprises a plurality of the heads and the holding parts. A liquid ejection device comprising a head unit according to any one of claims 1 to 7.

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