JP2024006951A - Discharge head and discharge device - Google Patents

Abstract

To provide a discharge head in which an air bubble exhaust property at the time of initial filling and/or maintenance is improved and discharge stability at the time of discharging is improved.SOLUTION: A discharge head includes: a plurality of nozzles that discharge a discharged matter; a plurality of pressure chambers communicating with a plurality of nozzles; a plurality of supply flow path branches communicating with two or more of the pressure chambers; a recovery flow path branches communicating with two or more of the pressure chambers; a supply flow path mainstream 156 communicating with the plurality of supply flow path branches; a recovery flow path mainstream 157 communicating with the plurality of recovery flow path branches; a first bypass flow path 253 that causes the supply flow path mainstream and the recovery flow path mainstream to communicate with each other; and first opening and closing means 257 that opens and closes the first bypass flow path. A flow rate of the discharged matter flowing in the first bypass flow path decreases as a pressure difference between an upstream side and a downstream side of the first opening and closing means is increased.SELECTED DRAWING: Figure 7

Description

The present invention relates to an ejection head and an ejection device.

For example, as a head for discharging liquid, a plurality of nozzles are arranged in a two-dimensional matrix, and liquid is supplied from the main stream of the supply channel to the pressure chamber through the tributary of the supply channel, and from the pressure chamber to the tributary of the recovery channel to the main stream of the recovery channel. There is a device that collects liquid.

Conventionally, there have been known devices that include a bypass flow path that connects a common liquid chamber and a circulating common liquid chamber without going through a pressure chamber (individual liquid chamber), and a flow rate control means that controls the flow rate of the liquid flowing through the bypass flow path. (Patent Document 1). Patent Document 1 aims to improve bubble discharge performance and ensure the effect of suppressing viscosity change due to circulation.

In addition, the liquid flows from the common supply channel through the pressure chamber to the common recovery channel, a part of the common recovery channel is disposed above the common supply channel, and a connection is made from the common supply channel to the common recovery channel. One in which a passage is provided is known (Patent Document 2). Patent Document 2 aims to improve the ability to discharge bubbles within the common supply channel.

As described above, in the prior art, a configuration having a bypass flow path has been proposed for the purpose of improving the bubble discharging property within the head. However, as in the prior art, simply providing a bypass passage having means for adjusting the flow rate of the discharged material between the common liquid chamber on the supply side and the common liquid chamber on the recovery side does not sufficiently discharge air bubbles. That was difficult. For example, there is a problem that air bubbles remain in the individual liquid chambers during initial filling or maintenance. Furthermore, during printing operations, air bubbles from the common liquid chamber or tank may flow into the individual liquid chambers, making ejection unstable.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an ejection head that improves bubble evacuation performance during initial filling and/or maintenance, and improves ejection stability during printing operations.

In order to solve the above problems, the ejection head of the present invention includes:
a plurality of nozzles for discharging a material to be discharged;
a plurality of pressure chambers each communicating with the plurality of nozzles;
a plurality of supply channel tributaries that communicate with the two or more pressure chambers;
a plurality of recovery channel tributaries that communicate with the two or more pressure chambers;
a main supply flow path leading to the plurality of supply flow path tributaries;
a main recovery channel that communicates with the plurality of recovery channel tributaries;
a first bypass channel that connects the main stream of the supply channel and the main stream of the recovery channel;
A first opening/closing means for opening and closing the first bypass flow path,
The supply flow path tributary is a flow path that supplies the material to be discharged to the two or more pressure chambers,
The recovery channel tributary is a channel that recovers the discharged material from the two or more pressure chambers,
The main supply flow path is a flow path that supplies the material to be discharged to the plurality of supply flow path tributaries,
The main recovery flow path is a flow path that recovers the discharged material from the plurality of recovery flow path tributaries,
The flow rate of the discharged material flowing through the first bypass channel is characterized in that it decreases as the pressure difference between the upstream side and the downstream side of the first opening/closing means increases.

According to the present invention, it is possible to provide an ejection head that improves bubble evacuation performance during initial filling and/or maintenance, and improves ejection stability during printing operations.

FIG. 1 is a cross-sectional explanatory diagram showing an example of an ejection head according to the present invention. FIG. 3 is an explanatory plan view illustrating the flow path arrangement configuration of the ejection head. 3 is a cross-sectional explanatory diagram taken along line AA in FIG. 2. FIG. 3 is an explanatory cross-sectional view taken along line DD in FIG. 2. FIG. FIGS. 3A and 3B are explanatory cross-sectional views showing Comparative Example 1. FIGS. (a) is a case where the pressure difference is small, and (b) is a case where the pressure difference is large. 5A and 5B are explanatory diagrams illustrating the opening and closing means of Comparative Example 1. FIG. (a) is a case where the pressure difference is small, and (b) is a case where the pressure difference is large. 2A and 2B are cross-sectional explanatory views (a) and (b) showing Example 1. FIG. (a) is a case where the pressure difference is small, and (b) is a case where the pressure difference is large. FIGS. 7A to 7C are explanatory diagrams showing an example of the first opening/closing means. (a) is a case where the pressure difference is small, (b) is a case where the pressure difference is medium, and (c) is a case where the pressure difference is large. FIG. 7 is an explanatory cross-sectional view of an ejection head according to another example of the present invention. FIG. 7 is an explanatory cross-sectional view of an ejection head according to another example of the present invention. FIG. 7 is an explanatory plan view illustrating a flow path configuration of an ejection head according to another example of the present invention. 1 is a schematic explanatory diagram of an example of a printing device as a discharge device according to the present invention. FIG. 2 is an explanatory plan view of a discharge unit of the printing apparatus. FIG. 1 is a schematic diagram showing an example of a circulating ink supply system.

Hereinafter, a discharge head and a discharge device according to the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments shown below, and may be modified within the scope of those skilled in the art, such as other embodiments, additions, modifications, deletions, etc. These are also included within the scope of the present invention as long as they exhibit the functions and effects of the present invention.

The ejection head of the present invention includes:
a plurality of nozzles for discharging a material to be discharged;
a plurality of pressure chambers each communicating with the plurality of nozzles;
a plurality of supply channel tributaries that communicate with the two or more pressure chambers;
a plurality of recovery channel tributaries that communicate with the two or more pressure chambers;
a main supply flow path leading to the plurality of supply flow path tributaries;
a main recovery channel that communicates with the plurality of recovery channel tributaries;
a first bypass channel that connects the main stream of the supply channel and the main stream of the recovery channel;
A first opening/closing means for opening and closing the first bypass flow path,
The supply flow path tributary is a flow path that supplies the material to be discharged to the two or more pressure chambers,
The recovery channel tributary is a channel that recovers the discharged material from the two or more pressure chambers,
The main supply flow path is a flow path that supplies the material to be discharged to the plurality of supply flow path tributaries,
The main recovery flow path is a flow path that recovers the discharged material from the plurality of recovery flow path tributaries,
The flow rate of the discharged material flowing through the first bypass channel is characterized in that it decreases as the pressure difference between the upstream side and the downstream side of the first opening/closing means increases.

FIG. 1 is an explanatory cross-sectional view of the ejection head according to the present embodiment, in which (a) is a cross-sectional explanatory view corresponding to the line BB in FIG. 2, and (b) is an explanatory cross-sectional view corresponding to the line CC in FIG. It is a cross-sectional explanatory view. FIG. 2 is an explanatory plan view illustrating the flow path arrangement of the ejection head, and FIG. 3 is an explanatory cross-sectional view taken along line AA in FIG. 2.

This ejection head 100 includes a nozzle plate 110, an actuator member 101, and a common flow path member 170 that also serves as a frame member. The actuator member 101 includes an individual channel member (channel plate) 120, a diaphragm member 130, a piezoelectric element 140, and a common channel member 150.

The nozzle plate 110 has a plurality of nozzles 111 that eject liquid as an object to be ejected. The plurality of nozzles 111 are arranged in a two-dimensional matrix.

The individual flow path member 120 includes a plurality of pressure chambers (individual liquid chambers) 121 each communicating with the plurality of nozzles 111, a plurality of individual supply flow paths 122 each communicating with the plurality of pressure chambers 121, and a plurality of pressure chambers 121. A plurality of individual recovery channels 123 are formed. The individual supply channel 122 includes a supply side fluid resistance section 126, and the individual recovery channel 123 includes a recovery side fluid resistance section 127.

The diaphragm member 130 forms a diaphragm 131 that is a deformable wall surface of the pressure chamber 121, and a piezoelectric element 140 is integrally provided on the diaphragm 131. Further, the diaphragm member 130 is formed with a supply side opening 132 communicating with the individual supply channel 122 and a recovery side opening 133 communicating with the individual recovery channel 123. The piezoelectric element 140 is a pressure generating means that deforms the diaphragm 131 and pressurizes the liquid in the pressure chamber 121.

The common channel member 150 is a common channel tributary member, and includes a plurality of common supply channel tributaries 152 communicating with two or more individual supply channels 122 and a plurality of common supply channel tributaries 152 communicating with two or more individual recovery channels 123. Recovery channel tributaries 153 are formed adjacent to each other alternately. The supply flow path tributary 152 is a flow path that supplies the liquid to be discharged to two or more pressure chambers 121, and the recovery flow path tributary 153 supplies the liquid to be discharged from the two or more pressure chambers 121. This is a channel for recovery.

The common flow path member 150 includes a supply port 154 that communicates with the supply side opening 132 of the individual supply flow path 122 and the supply flow path tributary 152, and a recovery port that communicates with the recovery side opening 133 of the individual recovery flow path 123 and the recovery flow path tributary 153. A mouth 155 is formed.

The common flow path member 150 also includes a portion 156a of one or more common main supply flow paths 156 that communicate with the plurality of supply flow path tributaries 152 and a plurality of recovery flow path tributaries, which are formed together with the common flow path member 170. 153, forming a part 157a of one or more common main recovery channels 157.

The common channel member 170 is a common channel main stream member, and is formed together with the common channel member 150 and includes a part 156b of the main supply channel 156 that communicates with the plurality of supply channel tributaries 152 and a plurality of recovery channel tributaries. 153 forms a part 157b of the main recovery channel 157. A portion 156b of the main flow path 156 communicates with the supply port 171, and a portion 157b of the main flow path 157 communicates with the recovery port 172.

The main supply channel 156 is a channel for supplying liquid, which is a discharged material, to the plurality of supply channel tributaries 152, and the recovery channel main stream 157 supplies liquid, which is a discharged material, from a plurality of recovery channel tributaries 153. This is a flow path for collecting.

Externally, the common flow path member 170 includes a supply side tank section 181 that supplies liquid to the main flow path 156 through a supply port 171, and a liquid is discharged from the main flow path 157 through a recovery port 172. A recovery side tank section 182 is arranged. The supply side tank section 181 is provided with a supply port 183 through which liquid is supplied from the outside. The recovery side tank section 182 is provided with a recovery port 184 for discharging liquid to the outside.

In this embodiment, a first bypass flow path 253 is provided that communicates the main flow path 156 of the supply flow path and the main flow path of the recovery flow path 157. Here, the first bypass channel 253 is preferably a channel that connects the downstream end of the main supply channel 156 and the upstream end of the main recovery channel 157. In FIG. 2, the supply port is arranged on the left side of the main stream 156 of the supply channel (that is, the upstream side of the main stream 156 of the supply channel), and on the left side of the main stream 157 of the recovery channel (that is, on the downstream side of the main stream 157 of the recovery channel). A collection port is located.

Bubbles tend to accumulate at the downstream end (most downstream) of the main supply channel 156 and the upstream end (most upstream) of the main recovery channel 157, where the pressure is weak and the flow rate is low. Therefore, by connecting the downstream end of the main supply channel 156 and the upstream end of the main recovery channel 157 by the first bypass channel 253, the bubble discharge performance can be improved.

Further, a second bypass flow path 251 is provided that communicates the supply flow path tributary 152 and the recovery flow path main flow 157. The second bypass channel 251 passes through the end (most downstream side) of the supply channel tributary 152 and the main recovery channel 157 . This prevents air bubbles from remaining at the end of the supply channel tributary 152 during filling.

Further, a third bypass flow path 252 is provided which communicates the recovery flow path tributary 153 and the supply flow path main flow 156. The third bypass channel 252 passes through the end (most upstream side) of the recovery channel tributary 153 and the main supply channel 156 . This prevents air bubbles from remaining at the end of the recovery channel tributary 153 during filling.

The first bypass flow path 253 is provided with a first opening/closing means 257 that opens and closes the first bypass flow path 253 .
The second bypass flow path 251 is provided with a second opening/closing means 255 that opens and closes the second bypass flow path 251 .
The third bypass flow path 252 is provided with a third opening/closing means 256 that opens and closes the third bypass flow path 252 .

The first opening/closing means 257, the second opening/closing means 255, and the third opening/closing means 256 all open and close the flow passages depending on the pressure difference (differential pressure), and open according to the pressure difference (depending on the size of the differential pressure). The structure is such that the amount changes. In order to achieve a structure in which the amount of opening changes in accordance with the pressure difference, for example, there is a method using a valve body, which will be described later. By changing the opening amount according to the pressure difference, the flow rate of the discharged material flowing through the bypass channel changes according to the pressure difference.

The pressure difference here is the pressure difference between the upstream side and the downstream side of the opening/closing means. The upstream side of the opening/closing means is, for example, the upstream side of the opening/closing means, and includes the vicinity of the opening/closing means. Similarly, the downstream side of the opening/closing means is, for example, the downstream side of the opening/closing means, and includes the vicinity of the opening/closing means. Further, the upstream side of the opening/closing means includes an inlet of the opening/closing means, and the downstream side of the opening/closing means includes an outlet of the opening/closing means. In this case, the pressure difference is the pressure difference between the inlet and outlet of the first opening/closing means 257, the second opening/closing means 255, and the third opening/closing means 256.

In this embodiment, the pressure difference when the first opening/closing means 257 is in the open state is also referred to as a first predetermined value. Further, the pressure difference when the second opening/closing means 255 is in the open state is also referred to as a second predetermined value, and the pressure difference when the third opening/closing means 256 is in the open state is also referred to as a third predetermined value.

FIG. 4 is an explanatory cross-sectional view corresponding to the line DD in FIG. FIG. 4 shows a first bypass flow path 253 that communicates with the main supply flow path 156 and the main flow recovery flow path 157. Further, the first bypass flow path 253 is provided with a first opening/closing means 257 that opens and closes the first bypass flow path 253 . Note that in FIG. 4, illustration of the nozzle plate 110 is omitted. Further, the pressure chambers (individual liquid chambers) 121 and the like are schematically illustrated, and are not limited to the illustrated shapes.

FIG. 5 is a diagram for explaining the configuration of Comparative Example 1, which is not included in the present invention, and is a cross-sectional explanatory diagram for explaining the line DD in FIG. FIG. 5(a) shows the case where the pressure difference is small, and FIG. 5(b) shows the case when the pressure difference is large. In the figure, arrows schematically indicate the flow of the material to be discharged.
FIG. 6 is a diagram showing a flow rate adjustment mechanism in Comparative Example 1. FIG. 6(a) shows a case where the pressure difference is small, and corresponds to the case of FIG. 5(a). FIG. 6(b) shows a case where the pressure difference is large, and corresponds to the case of FIG. 5(b).

FIG. 6 shows the valve body 273 and the regulating member 271, and when the valve body 273 contacts the regulating member 271, it is in a closed state. When the valve body 273 is not in contact with the regulating member 271, it is in an open state. The regulating member 271 may be a separate member or may be a part of the flow path.

As shown in FIGS. 5(a) and 6(a), when the pressure difference is small, the valve body 273 contacts the regulating member 271, and the first opening/closing means 257 is in a closed state. Therefore, when the pressure difference is small, the object to be discharged does not flow through the first bypass channel 253. On the other hand, as shown in FIGS. 5(b) and 6(b), when the pressure difference is large, the valve body 273 is deformed and separated from the regulating member 271, and the first opening/closing means 257 is in an open state. Therefore, the material to be discharged flows through the first bypass channel 253. Comparative Example 1 uses an adjustment mechanism that increases the flow rate of the first bypass channel 253 by increasing the pressure difference.

An example of air bubble discharge during initial filling and maintenance in Comparative Example 1 will be described.
First, the main supply channel 156 and its downstream side (that is, the branch supply channel 152 and the pressure chamber 121) are filled with the material to be discharged. Thereafter, the material to be discharged is supplied so that the pressure difference between the first opening and closing means becomes large. As a result, the first opening/closing means becomes open, and the flow rate of the first bypass channel increases. As the flow rate increases, for example, air bubbles generated or mixed in the main stream 156 of the supply channel or the branch 152 of the supply channel move to the main stream 157 of the recovery channel, and are discharged from the main stream 157 of the recovery channel to the external circulation path. be done.

Generally, during initial filling or maintenance, the supply amount of the discharged material is adjusted to increase the flow rate of the entire head, and the pressure difference between the supply port 183 and the recovery port 184 increases. Therefore, in the comparative example, the flow rate of the first bypass channel 253 becomes large during initial filling or maintenance, as shown in FIGS. 5(b) and 6(b). In this case, the material to be discharged is not sufficiently supplied to the pressure chamber 121, and the air bubbles in the pressure chamber 121 cannot be sufficiently discharged. If air bubbles remain in the pressure chamber 121, image distortion will occur.

On the other hand, during discharge, it is required to reduce the pressure difference across the meniscus. Therefore, the supply amount of the material to be discharged is adjusted, and the pressure difference between the supply port 183 and the recovery port 184 is reduced. Therefore, in Comparative Example 1, the flow rate of the first bypass channel 253 becomes small during discharge, as shown in FIGS. 5(a) and 6(a). In this case, the flow rate of the entire head becomes small, and air bubbles in the supply side tank and the main stream of the supply channel flow into the pressure chamber 121, and the air bubbles flowing into the pressure chamber 121 affect stable discharge.

As described above, in Comparative Example 1, a bypass flow path having means for adjusting the flow rate of the discharged material is provided between the common liquid chamber on the supply side and the common liquid chamber on the recovery side. Difficult to expel. For example, there is a problem in that during initial filling or maintenance, it is difficult to move the air bubbles in the individual liquid chambers, and the air bubbles remain in the individual liquid chambers. Furthermore, during discharge, air bubbles from the common liquid chamber or the tank may flow into the individual liquid chambers, making the discharge unstable.

In contrast, in this embodiment, the flow rate adjustment mechanism of the first opening/closing means 257 is devised. In this embodiment, the flow rate of the discharged material flowing through the first bypass channel 253 decreases as the pressure difference between the upstream side and the downstream side of the first opening/closing means 257 increases. In other words, the flow rate in the first bypass flow path changes depending on the pressure difference; when the pressure difference increases, the flow rate decreases, and when the pressure difference decreases, the flow rate increases. According to the present embodiment, it is possible to improve bubble evacuation performance during initial filling and maintenance, and it is possible to improve discharge stability during discharge.

FIG. 7 is a diagram for explaining an example of the present embodiment (Example 1), and is a cross-sectional explanatory diagram corresponding to the line DD in FIG. FIG. 7(a) shows a case where the pressure difference is small, and FIG. 7(b) shows a case where the pressure difference is large. In the figure, arrows schematically indicate the flow of the material to be discharged.
FIG. 8 is a diagram showing a flow rate adjustment mechanism in Example 1. FIG. 8(a) shows a case where the pressure difference is small, and corresponds to the case of FIG. 7(a). FIG. 8(b) shows a case where the pressure difference is moderate. FIG. 8(c) shows a case where the pressure difference is large, and corresponds to the case of FIG. 7(b).

FIG. 8 shows the valve body 273 and the regulating member 271, and when the valve body 273 contacts the regulating member 271, it is in a closed state. The flow rate of the first opening/closing means 257 is adjusted according to the pressure difference. When the valve body 273 is not in contact with the regulating member 271, it is in an open state. The regulating member 271 may be a separate member or may be a part of the flow path.

As shown in FIGS. 7(a) and 8(a), when the pressure difference is small, the valve body 273 is deformed and separated from the regulating member 271, and the first opening/closing means 257 is in an open state. Therefore, the material to be discharged flows through the first bypass flow path 253. In the first embodiment, the adjustment mechanism is such that the flow rate of the first bypass flow path 253 is increased by increasing the pressure difference.
On the other hand, as shown in FIGS. 7(b) and 8(c), when the pressure difference is large, the valve body 273 comes into contact with the regulating member 271, and the first opening/closing means 257 is in a closed state. Therefore, the object to be discharged does not flow through the first bypass channel 253.

Note that the case where the pressure difference is small means not only the case where there is no pressure difference but also the case where the pressure difference is smaller than a predetermined value. When the pressure difference when the first opening/closing means 257 is in the open state is defined as the first predetermined value, the case where the pressure difference is small here means the case where the pressure difference is smaller than the first predetermined value. Further, since the material to be discharged is supplied from the upstream side and collected on the downstream side, when a pressure difference occurs, the pressure on the upstream side becomes high and the pressure on the downstream side becomes low.

An example of air bubble discharge during initial filling and maintenance in Example 1 will be described.
First, the main supply channel 156 and its downstream side (that is, the branch supply channel 152 and the pressure chamber 121) are filled with the material to be discharged. Thereafter, the material to be discharged is supplied so that the pressure difference between the first opening and closing means 257 becomes large. In the first embodiment, as shown in FIGS. 7(b) and 8(c), the first opening/closing means 257 is in a closed state, and the material to be discharged does not flow through the first bypass channel 253, or the flow rate is low. becomes smaller. If the material to be discharged does not flow through the first bypass flow path 253 or the flow rate becomes small, the flow rate to the pressure chamber 121 increases and pressure can be applied to the pressure chamber 121. As a result, the bubbles in the pressure chamber 121 move to the main stream 157 of the recovery channel, and are discharged from the main stream 157 of the recovery channel to the external circulation path. Therefore, it is possible to improve the bubble evacuation performance during initial filling and maintenance.

In addition, the time of initial filling and the time of maintenance here mean the time of initial filling and/or the time of maintenance. That is, it is possible to improve the bubble discharge performance not only during initial filling but also during maintenance.

During discharge, it is necessary to reduce the pressure of the meniscus, so the pressure difference between the supply port 183 and the recovery port 184 becomes smaller. Therefore, in the first embodiment, as shown in FIGS. 7(a) and 8(a), the first opening/closing means 257 is in an open state, and the flow rate of the discharged material in the first bypass channel 253 is increased. . Thereby, the flow rate of the entire head can be increased, and filling performance is improved. Furthermore, during the printing operation, the material to be discharged can flow through the first bypass flow path 253, so that it is possible to avoid excessive flow of the material to the pressure chamber 121, and the necessary amount of the material to be discharged can be It flows into chamber 121. Therefore, air bubbles generated or mixed in the main supply flow path 156 or the supply side tank portion 181 can be suppressed from moving to the pressure chamber 121. Thereby, the ejection stability during printing operation can be improved.

Furthermore, during printing operation, the flow rate of the entire head can be increased, making it easier to control the temperature during circulation. This also leads to improvement in filling performance and discharge stability. The filling performance at this time is not limited to the pressure chamber 121, but can also improve the filling performance within the main stream of the supply channel 156 and the supply side tank section 181.

In addition, during maintenance (including initial filling), for example, increase the pressure difference between the supply side and the recovery side (for example, the pressure difference between the supply port 183 and the recovery port 184), and during discharge, increase the pressure between the supply side and the recovery side. Reduce the difference. In order to adjust the pressure difference in this way, for example, an air pump can be provided in each of the supply side tank section and the recovery side tank section that are externally attached to the discharge head, and the pressure can be controlled by the air pump.

FIG. 14 shows an example of a circulating ink supply system for explaining the air pump. However, the present invention is not limited to this. As shown in the figure, air pumps 281 and 282 are provided in the supply side tank section 181 and the recovery side tank section 182, respectively. Arrows in the figure schematically indicate an example of positive pressure and negative pressure control by the air pumps 281 and 282. By adjusting the air pumps 281 and 282, the valve 283, and the ink supply pump 284, ink can be supplied from the ink tank 285, the ink can be circulated, and the pressure difference can be adjusted.

In this embodiment, the second opening/closing means 255 and the third opening/closing means 256, like the first opening/closing means 257, reduce the flow rate of the discharged material when the pressure difference becomes large, and when the pressure difference becomes small, the flow rate of the discharged material decreases. The configuration is such that the flow rate is large. In this way, the purpose of the second opening/closing means 255 and the third opening/closing means 256 is to reduce the flow rate of the discharged material when the pressure difference increases, so that pressure can be applied to the individual channels, This is because bubbles in the flow path can be efficiently discharged.

In this embodiment, it is preferable that the second opening/closing means 255 and the third opening/closing means 256 open with a larger pressure difference than the first opening/closing means 257.
That is, the pressure difference when the first opening/closing means 257 is in the open state is the first predetermined value, the pressure difference when the second opening/closing means 255 is in the open state is the second predetermined value, and the third opening/closing means 256 is the first predetermined value. When the pressure difference when the open state is set as the third predetermined value,
It is preferable that the second predetermined value>the first predetermined value and the third predetermined value>the first predetermined value.
By satisfying such a relationship, when performing a printing operation after filling, the second opening/closing means 255 and the third opening/closing means 256 will be more difficult to open than the first opening/closing means 257, and the discharged material will flow to areas other than the nozzle section. can be suppressed. Therefore, it becomes easier to supply the material to be discharged to the pressure chamber 121 during the printing operation.

As described above, the first opening/closing means in this embodiment has a configuration in which the flow rate of the discharged material changes depending on the pressure difference, and as the pressure difference increases, the flow rate decreases. The first opening/closing means in this embodiment has a cantilever structure as shown in FIG. When the free end 273b and the regulating member 271 are in contact with each other, the regulating member 271 is in a closed state. This state is shown in FIG. 8(c).

The regulating member 271 is provided in the first bypass flow path 253, and the regulating member 271 regulates the free end 273b of the valve body 273 at a predetermined position.

When the pressure difference between the upstream side and the downstream side of the first opening/closing means is smaller than a threshold value, the free end 273b of the valve body 273 is located upstream of the position where it contacts the regulating member 271 in the direction in which the discharged material flows. . This state is shown in FIGS. 8(a) and 8(b).

As the valve body 273, for example, an elastically deformable member can be used.

In the first opening/closing means 257 in this embodiment, when there is no pressure difference or is smaller than a predetermined pressure difference, the first opening/closing means 257 is in an open state as shown in FIG. 8(a). Further, in FIG. 8(a), the valve body 273 is wide open, and the flow rate is large.

As the pressure difference increases, the valve body 273 changes as shown in FIGS. 8(a)→(b)→(c), and the first opening/closing means closes. Conversely, when the pressure difference becomes smaller, the first opening/closing means opens as shown in FIGS. 8(c)→(b)→(a).

Another way to express this configuration is as follows. That is, when the straight line connecting the fixed end 273a and the free end 273b of the valve body 273 is defined as a first straight line, and the direction in which the discharged material in the first bypass channel 253 flows is defined as a second straight line, the first straight line and the second straight line are defined as The angle with the straight line changes as the pressure difference between the upstream side and the downstream side of the first opening/closing means 257 increases, and when the pressure difference becomes larger than a threshold value, the free end 273b of the valve body 273 closes to the regulating member. The angle is such that it makes contact with 271.
By doing so, it becomes easy to configure the first opening/closing means 257 such that the flow rate decreases as the pressure difference increases.

However, in this case, the valve body 273 does not need to be a linear member, for example, a plate-shaped member, and the first straight line can be defined even if the valve body 273 is deformed into a curve. Furthermore, even if the direction in which the discharged material flows changes at the first opening/closing means as shown in FIG. 8(b), the second straight line can be defined, for example from left to right on the page. . It is only necessary to express that the valve body 273 is inclined toward the upstream side in the flow direction of the discharged material in a state where the pressure difference is small.

Next, another example (Example 2) of this embodiment will be described with reference to FIG. 9. FIG. 9 is an explanatory cross-sectional view of the ejection head according to this example, in which (a) is an explanatory cross-sectional view along the main flow of the supply flow path, and (b) is an explanatory cross-sectional view along the main flow of the recovery flow path.

The ejection head 100 of this example has a fourth bypass flow path 254 that communicates with the supply side tank section 181 and the recovery side tank section 182. The fourth bypass flow path 254 is provided with a fourth opening/closing means 258 that opens and closes the fourth bypass flow path 254 . The fourth opening/closing means 258 is also constituted by a valve body whose opening/closing and opening amount changes depending on the pressure difference.

In this example, the pressure difference at which the first opening/closing means 257 opens is set to be larger than the pressure difference at which the fourth opening/closing means 258 opens. Note that in this example as well as in the above example, the second opening/closing means and the third opening/closing means can be opened with a pressure difference greater than that of the first opening/closing means.
In this example, when the pressure difference when the first opening/closing means 257 is in the open state is taken as the first predetermined value, and the pressure difference when the fourth opening/closing means 258 is in the open state is taken as the fourth predetermined value,
First predetermined value>fourth predetermined value.
Further, in this example, the fourth opening/closing means 258 is also configured such that the flow rate of the discharged material decreases as the pressure difference increases.

In this example, when initial filling is performed, the pressure difference further increases after the first bypass flow path 253 between the main supply flow path 156 and the main flow recovery flow path 157 is opened, similar to the above example. Then, the fourth opening/closing means 258 becomes open. When the fourth opening/closing means 258 is in the open state, the supply side tank section 181 and the recovery side tank section 182 communicate via the fourth bypass channel 254.

Thereby, the liquid flows from the supply side tank section 181 to the recovery side tank section 182, and the recovery side tank section 182 is reliably filled.

Therefore, first, the inside of the pressure chamber 121 is filled with low-pressure circulation, and then the circulation pressure is gradually increased to bypass the main flow path and the tributaries of the common flow path, between the main flow path of the common flow path, and between the tank sections in this order. The flow path is opened and filling can be performed in the order of common flow channel tributary → common flow channel main flow → recovery side tank section.

Here, if the fourth bypass flow path 254 that connects the supply side tank section 181 and the recovery side tank section 182 is made a constantly open flow path, when performing initial filling, from the beginning, from the supply side tank section 181 to the recovery side tank section. The liquid will flow to 182.

Therefore, air bubbles exist in the channels such as the main supply channel 156, the branch supply channel 152, the main stream 157 of the recovery channel, the branch 153 of the recovery channel, the pressure chamber 121, the individual supply channel 122, and the individual recovery channel 123. In order to discharge the liquid, it becomes necessary to supply the liquid under high pressure.

In contrast, in this example, the second bypass flow path 251, the third bypass flow path 252, the first bypass flow path 253, and the fourth bypass flow path 254 are opened in this order, so that the inside of the pressure chamber 121 is filled with low pressure circulation. After that, by gradually increasing the circulation differential pressure, the bypass flow path opens in the following order: between the main flow of the common flow path and the tributaries of the common flow path, between the main flow of the common flow path, and between the tank section. Filling can be done in the order of main stream → tank section.

The fourth bypass flow path 254 may be provided at a position as shown in FIG. Preferably.
FIG. 10 is a diagram showing another example of the fourth bypass flow path, in which (a) is an explanatory cross-sectional view along the main flow of the supply flow path, and (b) is an explanatory cross-sectional view along the main flow of the recovery flow path.
In this way, by having the fourth bypass flow path at the top of the tank, air bubbles at the top of the tank can be removed by circulation.

Next, another example (Example 3) of this embodiment will be described with reference to FIG. 11. FIG. 11 is an explanatory plan view illustrating the flow path configuration of the ejection head according to the same embodiment.

In the ejection head 100 of this example, as in the above example, a first bypass flow path 253 is provided that communicates with the main supply flow path 156 and the main flow recovery flow path 157. The first bypass flow path 253 is provided with a first opening/closing means 257 that opens and closes the first bypass flow path 253 .

Further, unlike the above example, a fifth bypass flow path 261a on the supply side and a fifth bypass flow path 261b on the recovery side are provided, which communicate the adjacent supply flow path tributary 152 and recovery flow path tributary 153.

Therefore, for example, two fifth bypass flow paths 261a are provided which respectively communicate with two supply flow path tributaries 152 arranged on both sides with one recovery flow path tributary 153 in between. Similarly, two fifth bypass channels 261b are provided which respectively communicate with two recovery channel tributaries 153 arranged on both sides of one supply channel tributary 152.

The fifth bypass flow path 261a is on the inlet side from the main supply flow path 156 to the supply flow path tributary 152, and on the side of the main supply flow path 156 than the supply port 54 and the recovery port 55, and is connected to the supply flow path tributary 152. It communicates with a recovery channel tributary 153.

The fifth bypass channel 261b is connected to the supply channel tributary 152 on the inlet side from the recovery channel tributary 153 to the recovery channel main stream 157, and on the recovery channel main stream 157 side from the supply port 54 and the recovery port 55. It communicates with a recovery channel tributary 153.

The fifth bypass flow path 261a is provided with a fifth opening/closing means 262a that opens and closes the fifth bypass flow path 261a. Further, the fifth bypass flow path 261a is provided with a fifth opening/closing means 262b that opens and closes the fifth bypass flow path 261b.

The fifth opening/closing means 262a, 262b, like the first opening/closing means 151, etc., are both configured with valve bodies that open and close the flow passages depending on the pressure difference, and whose opening amount changes depending on the magnitude of the pressure difference. .

In this example, the fifth opening/closing means 262a, 262b can both be opened with a smaller pressure difference than the first opening/closing means 257, and the fifth bypass channels 261a, 261b have a pressure smaller than that of the first bypass channel 253. I'm trying to make a difference.

Next, liquid filling into the ejection head 100 configured as described above will be described.
When initially filling the ejection head 100 with liquid, as described above, the main supply channel 156, the tributary supply channel 152, the main recovery channel 157, the tributary recovery channel 153, the pressure chamber 121, the individual supply channel 122, It is necessary to discharge air bubbles existing in channels such as the individual recovery channel 123 to the recovery side tank section 182 and the recovery port 184.

Therefore, in this example, when filling the flow path of the ejection head 100 with liquid, first, the supply flow path is passed from the supply side tank section 181 to the supply port 171 at a pressure such that the fifth opening/closing means 262a and 262b close the pressure difference. Main stream 156 is supplied with liquid. At this time, the first opening/closing means 257 and the fifth opening/closing means 262a, 262b are both in a closed state, and the first bypass flow path 253 and the fifth bypass flow paths 261a, 261b are closed.

As a result, the liquid supplied to the main supply channel 156 passes from the supply channel tributary 152 to the individual supply channel 122, the pressure chamber 121, and the individual recovery channel 123, reaches the recovery channel tributary 153, and then reaches the recovery channel tributary 153. It flows from the tributary stream 153 to the main stream 157 of the recovery channel.

Next, when the pressure of the liquid supplied from the supply side tank part 181 to the main supply channel 156 through the supply port 171 is increased, the pressure difference between the supply channel tributary 152 and the recovery channel tributary 153 increases to a fifth predetermined value (fifth (predetermined value<first predetermined value) or more, and the fifth opening/closing means 262a, 262b are in the open state. When the fifth opening/closing means 262a, 262b are in the open state, the fifth bypass channels 261a, 261b are opened, and the supply channel tributary 152 and the recovery channel tributary 153 are connected via the fifth bypass channels 261a, 261b. It gets through.

As a result, the liquid that has entered the supply channel tributary 152 from the main supply channel 156 flows from the supply channel tributary 152 to the upstream side of the recovery channel tributary 153 via the fifth bypass channel 261a, and flows into the fifth bypass channel 261b to the downstream side of the recovery channel tributary 153.

At this time, the bubbles remaining on the downstream side of the supply channel tributary 152 are discharged to the downstream side of the recovery channel tributary 153 through the fifth bypass channel 261a. Further, the bubbles remaining on the upstream side of the recovery channel tributary 153 are sent to the upstream side of the recovery channel tributary 153 by the liquid flowing in from the fifth bypass channel 261b. This ensures that the supply channel tributary 152 and the recovery channel tributary 153 are filled with liquid.

By increasing the pressure of the liquid supplied from the supply side tank section 181 to the main supply channel 156 through the supply port 71, the pressure difference between the main supply channel 156 and the tributary recovery channel 153 becomes equal to or higher than the third predetermined value. Then, the first opening/closing means 257 becomes open. When the first opening/closing means 257 is in the open state, the first bypass flow path 253 is opened, and the main supply flow path 156 and the main flow recovery flow path 157 communicate with each other via the first bypass flow path 253.

As a result, the liquid supplied to the main supply channel 156 flows to the main recovery channel 157 via the first bypass channel 253 . At this time, bubbles remaining in the main stream 156 of the supply channel are discharged to the main stream 157 of the recovery channel, and the main stream 156 of the supply channel is reliably filled with liquid.

The air bubbles transferred to the main stream 157 of the recovery channel are sent to the recovery side tank section 182 through the recovery port 172, thereby ensuring that the main stream 157 of the recovery channel is also filled with liquid.

In addition, in this example, the above-mentioned example is also applied, and the fourth bypass flow path 254 that communicates with the supply side tank section 181 and the recovery side tank section 182, and the fourth opening/closing means for opening and closing the fourth bypass flow path 254. 258.

Next, an example of a printing device as a discharge device according to the present invention will be described with reference to FIGS. 12 and 13. FIG. 12 is a schematic explanatory diagram of the printing apparatus, and FIG. 13 is a plan explanatory diagram of a discharge unit of the printing apparatus.

The printing device 1 is a device that discharges liquid, and includes a carry-in section 10 for carrying in the sheet material P, a pre-processing section 20, a printing section 30, a drying section 40, and a carry-out section 50.

The printing apparatus 1 applies (applies) a pretreatment liquid as necessary to the sheet material P carried in (supplied) from the carry-in section 10 in a pretreatment section 20 serving as a pretreatment means, and applies (applies) a pretreatment liquid as necessary to the sheet material P carried in (supplied) from a carry-in section 10 . is applied to perform the required printing, and after drying the liquid adhering to the sheet material P in the drying section 40, the sheet material P is discharged to the carry-out section 50.

The carry-in section 10 includes a carry-in tray 11 (lower carry-in tray 11A, upper carry-in tray 11B) that accommodates a plurality of sheet materials P, and a feeding device 12 (12A) that separates sheet materials P from the carry-in tray 11 one by one and sends them out. , 12B), and supplies the sheet material P to the preprocessing section 20.

The pre-processing section 20 includes a coating section 21 that is a processing liquid applying means that applies a processing liquid having the effect of coagulating ink and preventing show-through to the printing surface of the sheet material P, for example.

The printing section 30 includes a drum 31 that is a supporting member (rotating member) that rotates while supporting the sheet material P on its circumferential surface, and a liquid discharge section 32 that discharges liquid toward the sheet material P supported on the drum 31. We are prepared.

The printing section 30 also includes a transfer cylinder 34 that receives the sheet material P fed from the preprocessing section 20 and passes the sheet material P to and from the drum 31, and a transfer cylinder 34 that receives the sheet material P conveyed by the drum 31 and dries it. It is provided with a delivery cylinder 35 for delivering to the section 40.

The leading end of the sheet material P conveyed from the pre-processing section 20 to the printing section 30 is gripped by a gripping means (sheet gripper) provided on the transfer cylinder 34, and is conveyed as the transfer cylinder 34 rotates. The sheet material P conveyed by the transfer drum 34 is delivered to the drum 31 at a position facing the drum 31.

A gripping means (sheet gripper) is also provided on the surface of the drum 31, and the leading end of the sheet material P is gripped by the gripping means (sheet gripper). A plurality of suction holes are formed in a distributed manner on the surface of the drum 31, and suction means generates a suction airflow directed inward from the required suction holes of the drum 31.

The sheet material P transferred from the transfer drum 34 to the drum 31 is gripped at the leading end by a sheet gripper, is suctioned and supported on the drum 31 by the suction airflow by the suction means, and is conveyed as the drum 31 rotates. be done.

The liquid discharge section 32 includes a discharge unit 33 (33A to 33D) which is a discharge means. For example, the ejection unit 33A emits cyan (C) liquid, the ejection unit 33B emits magenta (M) liquid, the ejection unit 33C emits yellow (Y) liquid, and the ejection unit 33D emits black (K) liquid. Discharge each. In addition, it is also possible to use a discharge unit that discharges a special liquid such as white or gold (silver).

For example, as shown in FIG. 13, the ejection unit 33 is a full-line head in which a plurality of ejection heads 100 each having a plurality of nozzles 111 arranged in a two-dimensional matrix are arranged in a staggered manner on a base member 331.

The ejection operation of each ejection unit 33 of the liquid ejection section 32 is controlled by a drive signal according to print information. When the sheet material P carried by the drum 31 passes through an area facing the liquid ejection section 32, liquids of each color are ejected from the ejection unit 33, and an image corresponding to the print information is printed.

The drying section 40 dries the liquid deposited on the sheet material P in the printing section 30. As a result, liquid components such as water in the liquid evaporate, the colorant contained in the liquid is fixed on the sheet material P, and curling of the sheet material P is suppressed.

The reversing mechanism section 60 is a mechanism that reverses the sheet material P using a switchback method when double-sided printing is performed on the sheet material P that has passed through the drying section 40, and the reversed sheet material P is transferred to the printing section 30. It is sent back to the upstream side of the transfer cylinder 34 through the conveyance path 61 .

The carry-out section 50 includes a carry-out tray 51 on which a plurality of sheet materials P are loaded. The sheet materials P conveyed from the drying section 40 via the reversing mechanism section 60 are sequentially stacked and held on the carry-out tray 51.

The material to be discharged by the above-mentioned discharge head 100 may have a viscosity and surface tension that can be discharged from the head, and is not particularly limited. It is preferable that it be less than or equal to s. More specifically, solvents such as water and organic solvents, coloring agents such as dyes and pigments, functional materials such as polymerizable compounds, resins, and surfactants, and biocompatible materials such as DNA, amino acids, proteins, and calcium. , edible materials such as natural pigments, etc., and these include, for example, inkjet inks, surface treatment liquids, constituent elements of electronic devices and light emitting devices, and formation of electronic circuit resist patterns. It can be used for purposes such as a liquid for use in liquids, a material liquid for three-dimensional modeling, etc.

Here, examples of liquids used to form three-dimensional objects (material liquid for three-dimensional printing) include hydrogel-forming materials for forming three-dimensional three-dimensional structures used in therapeutic training. It will be done.

The hydrogel-forming material contains water and a polymerizable monomer, preferably contains a mineral and an organic solvent, and further contains a polymerization initiator and other components as necessary. The polymerizable monomer is a compound having one or more unsaturated carbon-carbon bonds, and preferably a polymerizable monomer that is polymerized by active energy rays such as ultraviolet rays or electron beams.

Examples of the polymerizable monomer include monofunctional monomers and polyfunctional monomers. These may be used alone or in combination of two or more.
Examples of the polyfunctional monomer include bifunctional monomers, trifunctional monomers, and tetrafunctional or higher functional monomers.

The mineral is not particularly limited and can be selected as appropriate depending on the purpose, but since the hydrogel has water as its main component, clay minerals are preferable, and furthermore, clay minerals are preferable because they are uniformly dispersed in water at the level of primary crystals. Possible layered clay minerals are preferred, and water-swellable layered clay minerals are more preferred.

Examples of the organic solvent include water-soluble organic solvents. The water solubility of the water-soluble organic solvent means that the organic solvent can be dissolved in water in an amount of 30% by mass or more.

The water-soluble organic solvent is not particularly limited and can be appropriately selected depending on the purpose, for example, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, Alkyl alcohols having 1 to 4 carbon atoms such as tert-butyl alcohol; amides such as dimethylformamide and dimethylacetamide; ketones or ketone alcohols such as acetone, methyl ethyl ketone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; Ethylene glycol, propylene glycol, 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, diethylene glycol, triethylene glycol, 1,2,6-hexanetriol, thio Polyhydric alcohols such as glycol, hexylene glycol, and glycerin; Polyalkylene glycols such as polyethylene glycol and polypropylene glycol; Ethylene glycol monomethyl (or ethyl) ether, diethylene glycol methyl (or ethyl) ether, triethylene glycol monomethyl (or ethyl) Lower alcohol ethers of polyhydric alcohols such as ethers; alkanolamines such as monoethanolamine, diethanolamine, triethanolamine; N-methyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone Examples include. These may be used alone or in combination of two or more. Among these, polyhydric alcohol, glycerin, and propylene glycol are preferred, and glycerin and propylene glycol are more preferred, from the viewpoint of moisturizing properties.

The polymerization initiator is not particularly limited and can be appropriately selected depending on the purpose, and includes, for example, a photopolymerization initiator, a thermal polymerization initiator, and the like.
As the photopolymerization initiator, any substance that generates radicals upon irradiation with light (especially ultraviolet rays with a wavelength of 220 nm to 400 nm) can be used.

Note that when three-dimensional modeling is performed using a hydrogel-forming material, a UV irradiation mechanism is provided, and the discharged hydrogel-forming material is cured and formed by irradiating it with UV.

(Specific example of hydrogel forming material)
While stirring 120.0 parts by mass of ion-exchanged water that had been degassed under reduced pressure for 30 minutes, a composition of [Mg _5.34 Li _0.66 Si ₈ O ₂₀ (OH) ₄ ] Na ^- _0.66 as a layered clay mineral was prepared. 12.0 parts by mass of synthetic hectorite (Laponite XLG, manufactured by Rockwood) having the following were added little by little and stirred. Furthermore, 0.6 parts by mass of etidronic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) was added and stirred to prepare a dispersion.

To the resulting dispersion, 44.0 parts by mass of acryloylmorpholine (manufactured by KJ Chemicals Co., Ltd.), which had been passed through an activated alumina column to remove the polymerization inhibitor, and methylene bisacrylamide (manufactured by Tokyo Kasei Kogyo Co., Ltd.) were added as polymerizable monomers. ) 0.4 part by mass was added.
Furthermore, 20.0 parts by mass of glycerin (manufactured by Sakamoto Pharmaceutical Co., Ltd.) and 0.8 parts by mass of N,N,N',N'-tetramethylethylenediamine (manufactured by Tokyo Chemical Industry Co., Ltd.) were mixed to form a material for forming a hydrogel. I got it.

As described above, the ejection head 100 according to the present invention can also be used in an inkjet method for arbitrarily arranging cells in order to artificially form a tissue body made of cells, Cell ink) can be ejected.

The cell suspension (cell ink) contains at least cells and a cell desiccation inhibitor. Furthermore, the cell suspension (cell ink) contains a dispersion medium in which cells are dispersed, and may contain other additive materials such as a dispersant and a pH adjuster, if necessary.

There are no particular restrictions on the type of cell, and it can be selected as appropriate depending on the purpose. Taxonomically, for example, regardless of whether it is a eukaryotic cell, a prokaryotic cell, a multicellular biological cell, or a unicellular biological cell, Can be used for all cells. These may be used alone or in combination of two or more.

Examples of eukaryotic cells include animal cells, insect cells, plant cells, and fungi. These may be used alone or in combination of two or more. Among these, animal cells are preferable, and when the cells form a cell aggregate, cells adhere to each other and have cell adhesion to the extent that they cannot be isolated without physicochemical treatment. Cells are more preferred.

Cell desiccation inhibitors are substances that cover the surface of cells and have the function of suppressing cell desiccation, such as polyhydric alcohols, gel polysaccharides, and proteins selected from extracellular matrices. .

The dispersion medium is preferably a cell culture medium or buffer.
A medium is a solution that contains components necessary for the formation and maintenance of cell tissues, prevents dryness and adjusts the external environment such as osmotic pressure, and can be appropriately selected and used as long as it is known as a medium. can. If it is not necessary to keep the cells constantly immersed in the medium, the medium can be removed from the cell suspension as appropriate.
The buffer is used to adjust the pH depending on the cells and purpose, and any known buffer can be appropriately selected and used.

(Specific example of cell suspension (cell ink))
A green fluorescent dye (trade name: Cell Tracker Green, manufactured by Life Technologies) was dissolved in dimethyl sulfoxide (hereinafter referred to as "DMSO") at a concentration of 10 mmol/L (mM), and added to serum-free Dulbecco's modified Eagle's medium (Life Technologies). Technologies) to prepare a serum-free medium containing a green fluorescent dye at a concentration of 10 μmol/L (μM).

Next, 5 mL of a serum-free medium containing a green fluorescent dye was added to a dish of cultured NIH/3T3 cells (Clone 5611, JCRB Cell Bank), and placed in an incubator (KM-CC17RU2, manufactured by Panasonic Corporation, 37°C, 5% CO2 by volume). environment)) for 30 minutes.

Thereafter, the supernatant was removed using an aspirator. 5 mL of phosphate buffered saline (manufactured by Life Technologies, hereinafter also referred to as PBS(-)) was added to the dish, and the PBS(-) was removed by suction using an aspirator to wash the surface. After repeating the washing operation with PBS(-) twice, 2 mL of 0.05% by mass trypsin-0.05% by mass EDTA solution (manufactured by Life Technologies) was added to each dish.

Next, after heating in an incubator for 5 minutes to detach the cells from the dish, 10% by mass fetal bovine serum (hereinafter also referred to as "FBS") and 1% by mass antibiotic (Antibiotic-Antimycotic Mixed Stock Solution) were added. 100x), manufactured by Nacalai Tesque Co., Ltd.) was added.

Next, the cell suspension in which trypsin was inactivated was transferred to a 50 mL centrifuge tube, centrifuged (product name: H-19FM, manufactured by KOKUSAN, 1,200 rpm, 5 minutes, 5°C), and aspirated. The supernatant was removed using After removal, 2 mL of D-MEM containing 10% by mass FBS and 1% by mass antibiotic was added to the centrifuge tube, and gently pipetting was performed to disperse the cells to obtain a cell suspension.

10 μL of the cell suspension was taken out into an Eppendorf tube, and after adding 70 μL of the medium, 10 μL was taken out into another Eppendorf tube, 10 μL of 0.4% trypan blue staining solution was added, and pipetting was performed. 10 μL was taken out from the stained cell suspension and placed on a PMMA plastic slide. A cell suspension with a counted cell number was obtained by counting the number of cells using a brand name: Countess Automated Cell Counter (manufactured by Invitrogen).

PBS(-) was used as a dispersion medium. Glycerin (molecular biology grade, manufactured by Wako Pure Chemical Industries, Ltd.) as a cell drying inhibitor was dissolved in PBS (-) to a mass ratio of 0.5%, and the NIH/3T3 cell suspension was added. A cell ink was obtained by dispersing the cells in a dispersion medium at 6×10 6 cells/mL.

Aspects of the present invention are, for example, as follows.
<1> A plurality of nozzles that eject objects to be ejected;
a plurality of pressure chambers each communicating with the plurality of nozzles;
a plurality of supply channel tributaries that communicate with the two or more pressure chambers;
a plurality of recovery channel tributaries that communicate with the two or more pressure chambers;
a main supply flow path leading to the plurality of supply flow path tributaries;
a main recovery channel that communicates with the plurality of recovery channel tributaries;
a first bypass channel that connects the main stream of the supply channel and the main stream of the recovery channel;
A first opening/closing means for opening and closing the first bypass flow path,
The supply flow path tributary is a flow path that supplies the material to be discharged to the two or more pressure chambers,
The recovery channel tributary is a channel that recovers the discharged material from the two or more pressure chambers,
The main supply flow path is a flow path that supplies the material to be discharged to the plurality of supply flow path tributaries,
The main recovery flow path is a flow path that recovers the discharged material from the plurality of recovery flow path tributaries,
The ejection head is characterized in that the flow rate of the object to be ejected flowing through the first bypass passage becomes smaller as the pressure difference between the upstream side and the downstream side of the first opening/closing means becomes larger.
<2> a second bypass flow path that connects the supply flow path tributary and the recovery flow path main stream;
a third bypass flow path that connects the recovery flow path tributary and the supply flow path main stream;
a second opening/closing means for opening and closing the second bypass flow path;
A third opening/closing means for opening and closing the third bypass flow path,
The second opening/closing means opens and closes depending on the pressure difference between the upstream side and the downstream side of the second opening/closing means,
The third opening/closing means opens and closes depending on the pressure difference between the upstream side and the downstream side of the third opening/closing means,
The ejection head according to <1>, wherein the second opening/closing means and the third opening/closing means are opened with a larger pressure difference than the first opening/closing means.
<3> The ejection head according to <2>, wherein the connection portion between the second bypass flow path and the supply flow path tributary is provided at an end of the supply flow path tributary.
<4> The discharge according to <2> or <3>, wherein the connection part between the third bypass flow path and the recovery flow path tributary is provided at an end of the recovery flow path tributary. head.
<5> A supply side tank communicating with the main stream of the supply flow path;
a recovery side tank communicating with the main stream of the recovery channel;
a fourth bypass flow path passing through the supply side tank and the recovery side tank;
A fourth opening/closing means for opening and closing the fourth bypass flow path,
The fourth opening/closing means opens and closes depending on the pressure difference between the upstream side and the downstream side of the fourth opening/closing means,
The ejection head according to any one of <1> to <4>, wherein the first opening/closing means opens with a larger pressure difference than the fourth opening/closing means.
<6> The ejection head according to <5>, wherein the fourth bypass flow path is provided at the top of the supply side tank and the recovery side tank.
<7> The first opening/closing means has a cantilever structure, and has a valve body with one end as a fixed end and the other end as a free end, and the valve body is provided in the first bypass flow path. When the regulating member that regulates the free end of the valve body at a predetermined position is in contact with the free end of the valve body, the valve body is in a closed state;
When the pressure difference between the upstream side and the downstream side of the first opening/closing means is smaller than a threshold value, the free end of the valve body is located upstream of the position where it contacts the regulating member in the direction in which the discharged material flows. The ejection head according to any one of <1> to <6>, characterized in that:
<8> When the straight line connecting the fixed end and the free end of the valve body is defined as a first straight line, and the direction in which the discharged material flows in the first bypass flow path is defined as a second straight line,
The angle between the first straight line and the second straight line changes as the pressure difference between the upstream side and the downstream side of the first opening/closing means increases, and when the pressure difference becomes larger than a threshold value, the valve The ejection head according to <7>, wherein the free end of the body is at an angle that makes contact with the regulating member.
<9> An ejection device comprising the ejection head according to any one of <1> to <8>.

1 Printing device 10 Carrying-in section 20 Pre-processing section 30 Printing section 40 Drying section 50 Carrying-out section 21 Coating section 33 Discharge unit 100 Discharge head 110 Nozzle plate 111 Nozzle 120 Individual channel member 121 Pressure chamber 122 Individual supply channel 123 Individual recovery flow Channel 130 Vibration plate member 140 Piezoelectric element 150 Common channel member 152 Supply channel tributary 153 Recovery channel tributary 154 Supply port 155 Recovery port 156 Supply channel main stream 157 Recovery channel main stream 251 Second bypass channel 252 Third bypass flow Path 253 First bypass flow path 254 Fourth bypass flow path 255 Second opening/closing means 256 Third opening/closing means 257 First opening/closing means 258 Fourth opening/closing means 260 Flow rate control valve 261a, 261b Fifth bypass flow path 262a, 262b Fifth Opening/closing means 271 Regulating member 273 Valve body

Japanese Patent Application Publication No. 2017-159561 JP2019-209595A

Claims (9)

a plurality of nozzles for discharging a material to be discharged;
a plurality of pressure chambers each communicating with the plurality of nozzles;
a plurality of supply channel tributaries that communicate with the two or more pressure chambers;
a plurality of recovery channel tributaries that communicate with the two or more pressure chambers;
a main supply flow path leading to the plurality of supply flow path tributaries;
a main recovery channel that communicates with the plurality of recovery channel tributaries;
a first bypass channel that connects the main stream of the supply channel and the main stream of the recovery channel;
A first opening/closing means for opening and closing the first bypass flow path,
The supply flow path tributary is a flow path that supplies the material to be discharged to the two or more pressure chambers,
The recovery channel tributary is a channel that recovers the discharged material from the two or more pressure chambers,
The main supply flow path is a flow path that supplies the material to be discharged to the plurality of supply flow path tributaries,
The main recovery flow path is a flow path that recovers the discharged material from the plurality of recovery flow path tributaries,
The ejection head is characterized in that the flow rate of the object to be ejected flowing through the first bypass passage becomes smaller as the pressure difference between the upstream side and the downstream side of the first opening/closing means becomes larger. a second bypass flow path that connects the supply flow path tributary and the recovery flow path main stream;
a third bypass flow path that connects the recovery flow path tributary and the supply flow path main stream;
a second opening/closing means for opening and closing the second bypass flow path;
A third opening/closing means for opening and closing the third bypass flow path,
The second opening/closing means opens and closes depending on the pressure difference between the upstream side and the downstream side of the second opening/closing means,
The third opening/closing means opens and closes depending on the pressure difference between the upstream side and the downstream side of the third opening/closing means,
The ejection head according to claim 1, wherein the second opening/closing means and the third opening/closing means are opened with a larger pressure difference than the first opening/closing means. The ejection head according to claim 2, wherein a connecting portion between the second bypass flow path and the supply flow path tributary is provided at an end of the supply flow path tributary. The ejection head according to claim 2, wherein a connection portion between the third bypass flow path and the recovery flow path tributary is provided at an end of the recovery flow path tributary. a supply side tank communicating with the main stream of the supply flow path;
a recovery side tank communicating with the main stream of the recovery channel;
a fourth bypass flow path passing through the supply side tank and the recovery side tank;
A fourth opening/closing means for opening and closing the fourth bypass flow path,
The fourth opening/closing means opens and closes depending on the pressure difference between the upstream side and the downstream side of the fourth opening/closing means,
The ejection head according to claim 1, wherein the first opening/closing means is opened at a pressure difference greater than that of the fourth opening/closing means. The ejection head according to claim 5, wherein the fourth bypass flow path is provided at the top of the supply side tank and the recovery side tank. The first opening/closing means has a cantilever structure, and has a valve body with one end as a fixed end and the other end as a free end, and the free end of the valve body provided in the first bypass flow path. When the regulating member that regulates the valve at a predetermined position is in contact with the free end of the valve body, the valve body is in a closed state;
When the pressure difference between the upstream side and the downstream side of the first opening/closing means is smaller than a threshold value, the free end of the valve body is located upstream of the position where it contacts the regulating member in the direction in which the discharged material flows. The ejection head according to claim 1, characterized in that: When a straight line connecting the fixed end and the free end of the valve body is defined as a first straight line, and a direction in which the discharged material flows in the first bypass flow path is defined as a second straight line,
The angle between the first straight line and the second straight line changes as the pressure difference between the upstream side and the downstream side of the first opening/closing means increases, and when the pressure difference becomes larger than a threshold value, the valve 8. The ejection head according to claim 7, wherein the free end of the body is at an angle that makes contact with the regulating member. An ejection device comprising the ejection head according to any one of claims 1 to 8.

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