JP7593403B2 - Droplet ejection head, image forming apparatus and manufacturing method - Google Patents

Description

The present invention relates to a droplet ejection head, an image forming apparatus, and a manufacturing method.

Conventionally, in inkjet image forming devices, a configuration in which ink is circulated within an inkjet head (droplet ejection head) is known. For example, in a configuration in which ink is circulated between an inkjet head and an ink tank, ink is supplied from an ink tank to an ejection flow path (e.g., a pressure chamber) provided with a nozzle (ejection hole) and ejected from the ejection hole, and is discharged from another flow path (e.g., a discharge path) communicating with the ejection flow path and returned to the ink tank.

Patent Document 1 also discloses a configuration in which liquid is circulated using a droplet ejection head. In this configuration, ejection holes are provided in an area where the direction of the liquid flow changes in the liquid flow path.

JP 2017-65249 A

However, in the discharge flow path section, liquid flows toward other flow path sections, so depending on the area within the discharge flow path section, there are areas where the flow of liquid is poor, which become so-called dead space.

Therefore, if the discharge hole is located in this dead space, the stirring effect caused by the circulation of liquid near the discharge hole will be weakened, which could result in poor discharge at the discharge hole.

The object of the present invention is to provide a droplet ejection head, an image forming apparatus, and a manufacturing method that can prevent the weakening of the stirring effect caused by the circulation of liquid near the ejection hole, and thereby prevent ejection defects from occurring at the ejection hole.

The droplet ejection head according to the present invention comprises:
a discharge section having a discharge hole through which droplets are discharged;
a discharge flow passage portion that is provided corresponding to the discharge hole, that constitutes a flow passage area for liquid to be discharged to the discharge hole, and that serves as a pressure chamber;
Equipped with
The discharge hole is arranged in a second region other than a first region in which the flow path resistance of the liquid is maximum, among a plurality of regions divided into the flow path region of the discharge flow path section, and in the second region in which the agitation effect of the liquid is greater than that of the first region .

The image forming apparatus according to the present invention comprises:
The droplet ejection head described above;
a liquid supply unit that supplies liquid to the droplet ejection head;
Equipped with.

The manufacturing method according to the present invention comprises the steps of:
A method for manufacturing a droplet ejection head including: an ejection section having an ejection hole through which droplets are ejected; and an ejection flow path section that is provided corresponding to the ejection hole, that constitutes a flow path region for liquid to be ejected into the ejection hole, and that is a pressure chamber, comprising:
Dividing the flow path region of the discharge flow path portion into a plurality of regions;
determining a second region other than the first region in which the flow path resistance of the liquid is maximum, the second region having a higher agitation effect on the liquid than the first region ;
disposing the outlet hole in the second region;
has.

According to the present invention, it is possible to prevent the agitation effect caused by the circulation of liquid near the discharge hole from weakening, and thus to prevent discharge defects from occurring at the discharge hole.

1 is a diagram showing a schematic configuration of an image forming apparatus according to an embodiment of the present invention; 1 is a block diagram showing a main functional configuration of an image forming apparatus; FIG. 2 is a cross-sectional view of an inkjet head. FIG. 2 is a diagram showing a pressure chamber substrate. 5 is a cross-sectional view of the head chip taken along line X1-X1 in FIG. 4. 5 is a cross-sectional view of the head chip taken along line X2-X2 in FIG. 4. FIG. 2 is a diagram showing a channel spacer substrate. FIG. 2 is a diagram showing a nozzle substrate. 5A and 5B are diagrams for explaining an example of an arrangement of ejection holes in a pressure chamber. 5A and 5B are diagrams for explaining an example of an arrangement of ejection holes in a pressure chamber.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Figure 1 is a diagram showing a schematic configuration of an image forming apparatus 1 according to an embodiment of the present invention.

The image forming device 1 is an inkjet type image forming device that records an image on a recording medium P. The image forming device 1 includes a paper feed unit 10, an image forming unit 20, a paper discharge unit 30, and a control unit 40.

Under the control of the control unit 40, the image forming device 1 transports the recording medium P stored in the paper feed unit 10 to the image forming unit 20, ejects ink onto the recording medium P in the image forming unit 20 to record an image, and transports the recording medium P with the image recorded to the paper discharge unit 30.

In detail, the image forming device 1 records a color image on the recording medium P by outputting four colors, yellow (Y), magenta (M), cyan (C), and black (K), overlapping them on the recording medium P at a predetermined number of recording gradations.

As the recording medium P, various media capable of fixing the ink that has landed on the surface, such as paper such as plain paper or coated paper, fabric or sheet-like resin, can be used.

The paper feed unit 10 has a paper feed tray 11 that stores the recording medium P, and a media supply unit 12 that transports and supplies the recording medium P from the paper feed tray 11 to the image forming unit 20. The media supply unit 12 has a ring-shaped belt supported by two rollers on the inside, and transports the recording medium P from the paper feed tray 11 to the image forming unit 20 by rotating the rollers with the recording medium P placed on this belt.

The image forming unit 20 has a conveying unit 21, a transfer unit 22, a heating unit 23, a head unit 24, an irradiation unit 25, a delivery unit 27, etc.

The transport unit 21 holds the recording medium P placed on the transport surface of a cylindrical transport drum 211, and the transport drum 211 rotates and moves around a rotation axis (cylindrical axis) extending in the width direction of the recording medium P, thereby transporting the recording medium P on the transport drum 211 in the transport direction along the transport surface.

The transport drum 211 has a claw portion and an air intake portion (not shown) for holding the recording medium P on its transport surface. The recording medium P is held on the transport surface by having its edge pressed down by the claw portion and being sucked to the transport surface by the air intake portion.

The transfer unit 22 is provided at a position between the media supply section 12 of the paper feed section 10 and the transport section 21, and holds and picks up one end of the recording medium P transported from the media supply section 12 with the swing arm section 221, and transfers it to the transport section 21 via the transfer drum 222.

The heating unit 23 is provided between the position of the transfer drum 222 and the position of the head unit 24, and heats the recording medium P transported by the transport unit 21 so that the temperature of the recording medium P falls within a predetermined temperature range. The heating unit 23 has, for example, an infrared heater, and energizes the infrared heater based on a control signal supplied from the control unit 40 to cause the infrared heater to generate heat.

The head unit 24 records an image by ejecting ink onto the recording medium P from nozzle openings provided on an ink ejection surface facing the transport surface of the transport drum 211 at an appropriate timing according to the rotation of the transport drum 211 on which the recording medium P is held.

The head unit 24 has multiple inkjet heads 100 (see FIG. 3), which are arranged such that the ink (droplet) ejection surface and the transport surface of the inkjet heads 100 are spaced a predetermined distance apart. The inkjet heads 100 correspond to the "droplet ejection head" of the present invention.

In the image forming device 1 of this embodiment, four head units 24 corresponding to the four colors of ink, Y, M, C, and K, are arranged at predetermined intervals in the order of colors Y, M, C, and K from the upstream side in the transport direction of the recording medium P. In other words, each head unit 24 is configured to be capable of ejecting multiple different types of ink.

The head unit 24 is used in a fixed position when recording an image, and records an image using a single pass method by sequentially ejecting ink at predetermined intervals (transport direction intervals) to different positions in the transport direction as the recording medium P is transported.

The irradiation unit 25 is disposed across the width of the transport unit 21, and irradiates the recording medium P placed on the transport unit 21 with electromagnetic waves (e.g., ultraviolet light with a wavelength of 395 nm) to harden and fix the ink ejected onto the recording medium P. The irradiation unit 25 is disposed opposite the transport surface between the position of the head unit 24 and the position of the transfer drum 271 of the delivery unit 27 in the transport direction.

The delivery section 27 has a belt loop 272 having a circular belt supported on the inside by two rollers, and a cylindrical transfer drum 271 that transfers the recording medium P from the conveying section 21 to the belt loop 272. The recording medium P transferred from the conveying section 21 to the belt loop 272 by the transfer drum 271 is transported by the belt loop 272 and sent to the paper discharge section 30.

The paper discharge section 30 has a plate-shaped paper discharge tray 31 on which the recording medium P sent out from the image forming section 20 by the delivery section 27 is placed.

Figure 2 is a block diagram showing the main functional configuration of the image forming device 1. The image forming device 1 includes a control unit 40, a head unit drive unit 50, a transport drive unit 60, an image processing unit 70, an input/output interface 80, and an ink supply unit 90.

The control unit 40 has a CPU 41 (Central Processing Unit), a RAM 42 (Random Access Memory), a ROM 43 (Read Only Memory) and a memory unit 44, and controls the overall operation of the image forming device 1.

The CPU 41 reads out various control programs and setting data stored in the ROM 43, stores them in the RAM 42, and executes the programs to perform various calculation processes.

RAM 42 provides working memory space for CPU 41 and stores temporary data. RAM 42 may include non-volatile memory.

The ROM 43 stores various control programs and setting data executed by the CPU 41. Note that a rewritable non-volatile memory such as an EEPROM (Electrically Erasable Programmable Read Only Memory) or a flash memory may be used instead of the ROM 43.

The storage unit 44 stores print jobs input from an external device (not shown) via the input/output interface 80 and image data of images to be recorded by the print jobs. For example, a hard disk drive (HDD) is used as the storage unit 44, and a dynamic random access memory (DRAM) may also be used in combination.

The head unit drive unit 50 supplies drive signals corresponding to image data to the recording elements of the head unit 24 at appropriate timing based on the control of the control unit 40, thereby causing the nozzles of the head unit 24 to eject an amount of ink corresponding to the pixel values of the image data.

Based on the control signal supplied from the control unit 40, the transport drive unit 60 supplies a drive signal to a transport drum motor provided on the transport drum 211 to rotate the transport drum 211 at a predetermined speed and timing. Based on the control signal supplied from the control unit 40, the transport drive unit 60 also supplies a drive signal to a motor for operating the medium supply unit 12, the delivery unit 22, and the delivery unit 27 to supply the recording medium P to the transport unit 21 and discharge it from the transport unit 21.

The image processing unit 70 performs a predetermined image processing on the image data stored in the memory unit 44, and stores the obtained image data in the memory unit 44. This image processing includes a correction process that corrects the image data by applying a correction table (not shown) to the image data, as well as a color conversion process, a tone correction process, a pseudo-halftone process, and the like.

The input/output interface 80 is connected to an input/output interface of an external device (e.g., a personal computer) and mediates the transmission and reception of data between the control unit 40 and the external device. The input/output interface 80 is composed of, for example, any one of various serial interfaces, various parallel interfaces, or a combination of these.

The ink supply unit 90 has an ink tank, a supply tank, a circulation tank, a pump, etc. (not shown), and supplies ink (liquid) to the inkjet head 100 of the head unit 24. The ink supply unit 90 corresponds to the "liquid supply unit" of the present invention.

By controlling the pump, the ink supply unit 90 supplies ink from the ink tank to the inkjet head 100 via the supply tank. The ink supply unit 90 also returns ink discharged from the inkjet head 100 to the ink tank via the circulation tank. In other words, ink circulates between the ink tank of the ink supply unit 90 and the inkjet head 100.

Next, we will explain the detailed structure of each inkjet head 100 in the head unit 24. Figure 3 is a cross-sectional view of the inkjet head 100.

As described above, the head unit 24 has multiple inkjet heads 100. As shown in Figure 3, the inkjet head 100 has a head chip 101, a manifold 102, etc.

The manifold 102 stores the ink to be supplied to the head chip 101 and is provided above the head chip 101. The manifold 102 is configured to supply ink to the head chip 101 and to be able to collect ink discharged from the head chip 101.

The manifold 102 supplies ink from an ink tank (not shown) to the head chip 101 and returns ink collected from the head chip 101 to the ink tank. This allows ink to circulate between the inkjet head 100 and the ink tank.

The head chip 101 is a generally rectangular prism-shaped member that is elongated in the left-right direction, and ink is supplied to the inside from the manifold 102, and the ink is ejected onto the recording medium P. The head chip 101 is constructed by stacking a pressure chamber substrate 110, a flow path spacer substrate 120, and a nozzle substrate 130 in this order from the top.

4, 5 and 6, the pressure chamber substrate 110 is provided with pressure chambers 111, air chambers 112, ink discharge paths 113, etc. A large number of pressure chambers 111 and air chambers 112 are provided so as to be arranged alternately in the left-right direction, and are provided in, for example, four rows in the front-rear direction.

The pressure chamber 111 has a generally rectangular cross section and is formed along the vertical direction. The pressure chamber 111 is provided across the pressure chamber substrate 110 and the flow path spacer substrate 120, and penetrates the pressure chamber substrate 110 and the flow path spacer substrate 120 in the vertical direction.

A manifold 102 is provided above the pressure chamber substrate 110 to store ink supplied from an ink tank (not shown) to the inkjet head 100. The pressure chamber 111 is connected to an ink storage portion in the manifold 102, and is adapted to store ink supplied from the storage portion.

The air chamber 112 has a generally rectangular cross section that is slightly larger than the pressure chamber 111, and is formed so as to be parallel to the pressure chamber 111 in the vertical direction. Unlike the pressure chamber 111, the air chamber 112 does not communicate with the ink storage section. Therefore, ink does not flow into the air chamber 112.

The pressure chamber 111 and the air chamber 112 are separated by a partition 114 made of a piezoelectric material. A drive electrode (not shown) is provided on the partition 114, and when a voltage is applied to the drive electrode, the partition 114 between adjacent pressure chambers 111 repeatedly undergoes shear mode type displacement, thereby applying pressure to the ink in the pressure chamber 111.

The ink discharge path 113 is arranged to avoid the portion of the pressure chamber substrate 110 in which the pressure chamber 111 and the air chamber 112 are provided, and has a first ink discharge path 113A and a second ink discharge path 113B.

The first ink discharge paths 113A extend in the left-right direction, and three are provided at the front, center, and rear ends of the pressure chamber substrate 110. The portion of the underside of the pressure chamber substrate 110 that corresponds to the first ink discharge paths 113A is open. The open portion of the first ink discharge path 113A communicates with a discharge flow path 121 of the flow path spacer substrate 120, which will be described later, and forms a flow path for discharging ink from the pressure chamber 111.

The second ink discharge passage 113B extends in the vertical direction and penetrates the pressure chamber substrate 110, and is provided in communication with the first ink discharge passage 113A at the right end of the pressure chamber substrate 110.

The second ink discharge path 113B is connected to the discharge liquid chamber of the manifold 102 provided on the upper side of the pressure chamber substrate 110. The second ink discharge path 113B forms a flow path for discharging the ink discharged to the first ink discharge path 113A to the discharge liquid chamber.

7, the flow path spacer substrate 120 is provided with the pressure chamber 111 and the discharge flow path 121. The discharge flow path 121 is a flow path through which the ink stored in the pressure chamber 111 is discharged, and branches off from the pressure chamber 111 and communicates with the first ink discharge path 113A.

In addition, from the standpoint of ink discharge efficiency, it is preferable that two or more discharge flow paths 121 be provided in one pressure chamber 111.

As shown in Figure 8, the nozzle substrate 130 is provided with a plurality of ejection holes 131. The ejection holes 131 penetrate the nozzle substrate 130 in the vertical direction, and are provided at positions corresponding to the respective pressure chambers 111. The nozzle substrate 130 corresponds to the "ejection section" of the present invention.

Next, the arrangement of the ejection holes 131 in the nozzle substrate 130 will be described. Figures 9 and 10 are diagrams for explaining an example of the arrangement of the ejection holes 131 in the pressure chamber 111.

The pressure chamber 111 constitutes an ink flow path region in which ink is supplied and ejected through the ejection hole 131 while ejecting the ink through the ejection flow path 121. The pressure chamber 111 corresponds to the "ejection flow path section" of the present invention. The ejection flow path 121 corresponds to the "other flow path section" of the present invention.

In the pressure chamber 111, liquid flows toward the discharge flow path 121, so certain areas of the pressure chamber 111 become dead spaces where the flow of ink is poor. In the dead spaces, the stirring effect caused by the circulation of ink is weakened, so if the ejection hole 131 is placed in the dead space, the above-mentioned stirring effect cannot be obtained at the ejection hole 131, which may result in ejection failure at the ejection hole 131.

Therefore, in this embodiment, the ejection hole 131 is arranged in a second region other than the first region in which the ink flow resistance is maximum, among the multiple regions obtained by dividing the pressure chamber 111. Specifically, the ejection hole 131 is arranged in the second region in which the ink flow resistance is minimum, among the multiple regions.

For example, as shown in FIG. 9, assume that one exhaust flow path 121 is provided in the pressure chamber 111. The flow path resistance can be calculated based on the exhaust flow path 121. Specifically, the flow path resistance can be calculated based on the following equation (1) showing the Hagen-Poiseuille equation.

R=8πηL/(SΦ)...(1)

In formula (1), R is the flow path resistance [Pa·s/m ³ ], η is the ink viscosity [Pa·s], L is the length of the ink channel [m], S is the flow path cross-sectional area [m ² ], and Φ is the equivalent flow path cross-sectional area [m ² ].

Here, the pressure chamber 111 is divided into two regions A1 and A2. Region A1 is the region in which the exhaust flow path 121 is arranged. Region A2 is the region in which the exhaust flow path 121 is not arranged. The boundary line D1 between region A1 and region A2 is, for example, a line parallel to the vertical direction passing through the center point C of the pressure chamber 111, and is a line that does not intersect with the exhaust flow path 121.

The flow resistance of region A1 is determined by applying the dimensions of the discharge flow path 121 to formula (1), and is set to, for example, R1. The flow resistance of region A2 is determined to be infinite because the discharge flow path 121 does not exist and the flow path cross-sectional area is 0.

In this case, the region where the flow path resistance is the smallest is region A1, where the flow path resistance is R1, so the discharge hole 131 is positioned in region A1.

In addition, the number of regions into which the pressure chamber 111 is divided may be two or more. For example, as shown in FIG. 10, assume that the pressure chamber 111 is provided with four discharge flow paths 121A, 121B, 121C, and 121D.

The exhaust flow path 121A is provided at the bottom of the left side of the pressure chamber 111. The exhaust flow path 121B is provided at the left part of the bottom side of the pressure chamber 111. The exhaust flow path 121C is provided at the bottom of the right side of the pressure chamber 111. The exhaust flow path 121D is provided at the left part of the top side of the pressure chamber 111.

In this case, for example, the pressure chamber 111 is divided into four regions B1, B2, B3, and B4. The pressure chamber 111 is divided by boundaries D1 and D2 that pass through the center point C. The boundary D1 is a line parallel to the vertical direction, as in FIG. 9. The boundary D2 is a line parallel to the horizontal direction. The boundaries D1 and D2 do not intersect with each of the discharge flow paths 121A, 121B, 121C, and 121D.

Area B1 is the lower left area of the pressure chamber 111. Area B2 is the lower right area of the pressure chamber 111. Area B3 is the upper right area of the pressure chamber 111. Area B4 is the upper left area of the pressure chamber 111.

Two discharge flow paths 121A and 121B are provided in region B1. One discharge flow path 121C is provided in region B2. No discharge flow path is provided in region B3. One discharge flow path 121D is provided in region B4.

The flow path resistance of each of the discharge flow paths 121A, 121B, 121C, and 121D is the same, for example, R2. Since two discharge flow paths 121A and 121B are provided in region B1, their combined resistance is equal to two resistances connected in parallel, so 1/(1/R2 + 1/R2) = R2/2. Since one discharge flow path 121C and one discharge flow path 121D are each provided in region B2 and region B4, each flow path resistance is R2. Since no discharge flow path is provided in region B3, the flow path resistance is infinite.

In this case, the flow path resistance is smallest in region B1 where the flow path resistance is R2/2, so the discharge hole 131 is positioned in region B1.

In this way, in this embodiment, the discharge hole 131 can be positioned to avoid areas that would become dead space where flow path resistance would be high, thereby preventing the stirring effect caused by the circulation of liquid near the discharge hole 131 from weakening.

Next, a method for manufacturing the inkjet head 100 (head chip 101) according to this embodiment will be described. Note that in the following explanation, only the method for manufacturing the ejection holes 131 in the nozzle substrate 130 will be described, and the manufacturing of the other parts is similar to known methods.

First, the portion of the nozzle substrate 130 that corresponds to the pressure chamber 111 is divided into a number of regions. Here, it is desirable that each boundary between the multiple regions passes through the center point of the pressure chamber 111. In this way, it is possible to divide each region evenly.

It is also desirable that the number of divided regions is equal to or greater than the number of discharge flow paths. If the number of divided regions is small, that is, if each region is relatively wide, the range in which discharge holes 131 can be arranged is widened, and even within that region, differences in the flow of liquid are likely to occur between parts close to the discharge flow paths and parts far from the discharge flow paths. Furthermore, if discharge holes 131 are arranged in parts far from the discharge flow paths, the effect of stirring the liquid near discharge holes 131 may be weakened if that part is located near the border with a region where dead space exists.

Therefore, by increasing the number of divided regions according to the number of discharge flow paths, i.e., narrowing each region, it is possible to reduce differences in the flow of liquid within the region and position the discharge hole 131 at a position that provides the greatest liquid stirring effect.

It is also preferable that the boundaries of the regions are located at positions that do not intersect with the discharge flow path 121. This eliminates the need to decide to which region the flow path resistance based on the discharge flow path should be allocated, making it easier to calculate the flow path resistance of each region.

Next, the flow path resistance of each region in the pressure chamber 111 is calculated to determine the region with the smallest flow path resistance. Note that the method of calculating the flow path resistance is not limited to the above formula (1), and various methods may be applied. In addition, the magnitude of the flow path resistance may be determined by the number of discharge flow paths in the region.

Then, the ejection hole 131 is formed in the determined area. In this way, it is possible to easily avoid areas in the pressure chamber 111 where dead space exists.

According to the present embodiment configured as described above, the discharge hole 131 can be positioned to avoid the area where dead space exists in the pressure chamber 111. As a result, it is possible to prevent the stirring effect caused by the circulation of the liquid in the vicinity of the discharge hole 131 from being weakened, and thus it is possible to prevent discharge defects from occurring in the discharge hole 131.

In addition, since the discharge hole 131 is positioned in an area where the flow path resistance is minimum, the stirring effect due to the circulation of liquid near the discharge hole 131 can be enhanced, and thus the occurrence of discharge defects at the discharge hole 131 can be suppressed.

In addition, because the ejection hole 131 is disposed in one of the regions divided within the pressure chamber 111, i.e., in a region of a relatively wide range, the ejection hole 131 can be formed without being affected as much by manufacturing errors, compared to a configuration in which the position of the ejection hole is limited, such as a configuration in which the ejection hole is disposed at a point where the ink flow is changed. As a result, it is possible to suppress variations in the ink stirring effect near the ejection hole 131 caused by manufacturing errors.

In addition, since the position of the ejection hole 131 can be determined at the design stage based on the flow path resistance, manufacturing of the inkjet head 100 can be simplified.

In the above embodiment, the ejection hole 131 is disposed in the region where the flow path resistance is the minimum, but the present invention is not limited to this, and any region (second region) other than the region (first region) where the flow path resistance is the maximum may be used. However, from the viewpoint of the ink stirring effect near the ejection hole 131, it is preferable that the ejection hole 131 be disposed in the region where the flow path resistance is the minimum.

In addition, in the above embodiment, the boundaries of the multiple regions pass through the center point of the pressure chamber 111, but the present invention is not limited to this, and the boundaries do not have to pass through the center point of the pressure chamber. However, from the viewpoint of making each region somewhat wider to facilitate the arrangement of the ejection holes, it is preferable that the boundaries of the multiple regions pass through the center point of the pressure chamber.

In addition, in the above embodiment, the inkjet head 100 has a shear mode structure, but the present invention is not limited to this and may have other structures, such as a bend mode structure.

In addition, in the above embodiment, the pressure chamber is the ejection flow path portion, but if the inkjet head has a structure other than that of the above embodiment, the flow path portion in which the ejection hole is provided may also be the ejection flow path portion.

In addition, the above embodiments are merely examples of the realization of the present invention, and the technical scope of the present invention should not be interpreted in a limiting manner based on them. In other words, the present invention can be embodied in various forms without departing from its gist or main features. For example, the shapes, sizes, numbers and materials of each part described in the above embodiments are merely examples, and can be modified as appropriate.

REFERENCE SIGNS LIST 1 Image forming apparatus 10 Paper feed section 11 Paper feed tray 12 Medium supply section 20 Image forming section 21 Transport section 22 Delivery unit 23 Heating section 24 Head unit 25 Irradiation section 27 Delivery section 30 Paper discharge section 31 Paper discharge tray 100 Inkjet head 101 Head chip 102 Manifold 110 Pressure chamber substrate 111 Pressure chamber 112 Air chamber 113 Ink discharge channel 113A First ink discharge channel 113B Second ink discharge channel 114 Partition wall 120 Flow channel spacer substrate 121 Discharge flow channel 130 Nozzle substrate 131 Discharge hole

Claims (10)

a discharge section having a discharge hole through which droplets are discharged;
a discharge flow passage portion that is provided corresponding to the discharge hole, that constitutes a flow passage area for liquid to be discharged to the discharge hole, and that serves as a pressure chamber;
Equipped with
the discharge hole is disposed in a second region other than a first region in which the flow path resistance of the liquid is maximum, among a plurality of regions obtained by dividing the flow path region of the discharge flow path section, and in the second region in which the agitation effect of the liquid is higher than that of the first region .
Droplet ejection head. The second region is a region among the plurality of regions in which a flow path resistance of the liquid is minimum.
The droplet ejection head according to claim 1 . each boundary of the plurality of regions passes through a center point of the flow path region of the discharge flow path section;
The droplet ejection head according to claim 1 or 2. a discharge section having a discharge hole through which droplets are discharged;
a discharge flow path portion provided corresponding to the discharge hole and constituting a flow path region for liquid to be discharged into the discharge hole;
Equipped with
the discharge hole is disposed in a second region other than a first region in which a flow path resistance of the liquid is maximum, among a plurality of regions obtained by dividing the flow path region of the discharge flow path section,
each boundary of the plurality of regions passes through a center point of the flow path region of the discharge flow path section;
Droplet ejection head. a flow path region of the discharge flow path portion communicates with one or more other flow path portions other than the discharge flow path portion,
A flow path resistance of the liquid in each of the plurality of regions is a flow path resistance based on the one or more other flow path sections.
The droplet ejection head according to any one of claims 1 to 4. a discharge section having a discharge hole through which droplets are discharged;
a discharge flow path portion provided corresponding to the discharge hole and constituting a flow path region for liquid to be discharged into the discharge hole;
Equipped with
the discharge hole is disposed in a second region other than a first region in which a flow path resistance of the liquid is maximum, among a plurality of regions obtained by dividing the flow path region of the discharge flow path section,
a flow path region of the discharge flow path portion communicates with one or more other flow path portions other than the discharge flow path portion,
A flow path resistance of the liquid in each of the plurality of regions is a flow path resistance based on the one or more other flow path sections.
Droplet ejection head. The plurality of regions includes a number of regions greater than the number of the one or more other flow path portions.
7. The droplet ejection head according to claim 5 or 6. The boundaries of the plurality of regions do not intersect with the one or more other flow path portions.
The droplet ejection head according to any one of claims 5 to 7. A droplet ejection head according to any one of claims 1 to 8,
a liquid supply unit that supplies liquid to the droplet ejection head;
An image forming apparatus comprising: A method for manufacturing a droplet ejection head including: an ejection section having an ejection hole through which droplets are ejected; and an ejection flow path section that is provided corresponding to the ejection hole, that constitutes a flow path region for liquid to be ejected into the ejection hole, and that is a pressure chamber, comprising:
Dividing the flow path region of the discharge flow path portion into a plurality of regions;
determining a second region other than the first region in which the flow path resistance of the liquid is maximum, the second region having a higher agitation effect on the liquid than the first region ;
disposing the outlet hole in the second region;
The manufacturing method comprising the steps of:

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