JP6980991B2 - Liquid discharge head, liquid discharge unit, device that discharges liquid - Google Patents

Description

The present invention relates to a liquid discharge head, a liquid discharge unit, and a device for discharging a liquid.

In the liquid discharge head (droplet discharge head) that discharges liquid, in order to improve the efficiency when pressurizing the liquid in the individual liquid chambers, the common liquid chamber or the fluid resistance part from the liquid introduction part leading to the common liquid chamber. The liquid is supplied to the individual liquid chambers via the above.

Conventionally, a flow path plate forming a narrow fluid resistance part and a flow path wider than the fluid resistance part such as an individual liquid chamber on the downstream side of the fluid resistance part, a common liquid chamber on the upstream side, or a liquid introduction part. As a (fluid member), a stack of a plurality of plate-shaped members is known (Patent Document 1).

Further, a groove serving as a fluid resistance portion is formed in the nozzle plate, and the entire partition wall portion between the individual liquid chamber and the common liquid chamber formed in the flow path plate is made to face the groove serving as the fluid resistance portion, and the partition wall portion is formed. It is known that the width (length) defines the length of the fluid resistance portion (Patent Document 2).

Japanese Unexamined Patent Publication No. 10-138474 Japanese Unexamined Patent Publication No. 9-239978

By the way, when a plurality of plate-shaped members are laminated to form a flow path and a fluid resistance portion, when a groove portion or a through hole to be a fluid resistance portion is formed in the plate-shaped member, the direction of liquid flow (fluid resistance portion). Dimensional variation occurs at both ends of the).

Therefore, there is a problem that the length of the fluid resistance portion in the longitudinal direction varies and the fluid resistance (fluid resistance value) varies.

The present invention has been made in view of the above problems, and an object of the present invention is to reduce variations in fluid resistance.

In order to solve the above problems, the liquid discharge head according to the present invention is
A flow path having a width in the in-plane direction orthogonal to the direction of the liquid flow is formed in at least one of the fluid resistance portion and the downstream side and the upstream side of the fluid resistance portion. Equipped with a flow board
The flow path plate includes at least a stacked first plate-shaped member and a second plate-shaped member.
The first plate-shaped member is a through hole or groove including a wide portion that is a part of the flow path and a narrow portion that is connected to the wide portion and serves as a fluid resistance portion. Have,
The second plate-shaped member has a through hole or a groove portion that becomes a part of the flow path together with a wide portion of the through hole of the first plate-shaped member.
On the upstream side of the fluid resistance portion, the through hole or groove portion of the second plate-shaped member faces the narrow portion of the through hole of the first plate-shaped member.
On the downstream side of the fluid resistance portion, the through hole or groove portion of the second plate-shaped member is configured not to face the narrow portion of the through hole of the first plate-shaped member.

According to the present invention, the variation in fluid resistance can be reduced.

It is sectional drawing in the direction orthogonal to the nozzle arrangement direction (liquid chamber longitudinal direction) along the line AA of FIG. 3 of the liquid discharge head which concerns on 1st Embodiment of this invention. It is sectional drawing in the nozzle arrangement direction (liquid chamber short side direction) along the line BB of FIG. 1 of the head. It is a plane explanatory view of the main part of the head. It is a plane explanatory view seen from the plate-shaped member 2B side in the state which the plate-shaped members 2B and 2C constituting the flow path plate of the head are laminated. It is a plane explanatory view seen from the plate-shaped member 2B side in the state which the plate-shaped members 2A and 2B constituting the flow path board are laminated. It is an enlarged plane explanatory view of the flow path part including the fluid resistance part of the head. It is an enlarged plane explanatory view of the flow path part including the fluid resistance part in the liquid discharge head which concerns on 2nd Embodiment of this invention. It is sectional drawing explanatory drawing in the nozzle arrangement direction (liquid chamber short side direction) similar to FIG. 1 of the head. It is an enlarged plane explanatory view of the flow path part including the fluid resistance part in the liquid discharge head which concerns on 3rd Embodiment of this invention. It is sectional drawing explanatory drawing in the nozzle arrangement direction (liquid chamber short side direction) similar to FIG. 1 of the head. It is an external perspective explanatory view of the liquid discharge head which concerns on 4th Embodiment of this invention. It is sectional drawing which follows the liquid chamber longitudinal direction of the head. It is a plane explanatory view of the circulation flow path part of the head. It is a plane explanatory view of the main part of an example of the apparatus which discharges a liquid which concerns on this invention. It is explanatory drawing of the main part side surface of the apparatus. It is a plane explanatory view of the main part of another example of the liquid discharge unit which concerns on this invention. It is a front explanatory view of still another example of the liquid discharge unit which concerns on this invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The liquid discharge head according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a cross-sectional explanatory view of the head in a direction orthogonal to the nozzle arrangement direction (liquid chamber longitudinal direction) along the line AA of FIG. 3, and FIG. 2 is a nozzle arrangement direction (liquid) along the line BB of FIG. A cross-sectional explanatory view (in the direction from the short side of the chamber), FIG. 3 is a plan explanatory view with the plate-shaped member 2B of the head as the uppermost surface.

In this liquid discharge head, a nozzle plate 1, a flow path plate 2, and a diaphragm member 3 made of a thin film member as a wall surface member are laminated and joined. A piezoelectric actuator 11 that displaces the diaphragm member 3 and a frame member 20 as a common liquid chamber member are provided.

The flow path plate 2 forms an individual liquid chamber 6, a fluid resistance portion 7, and a liquid introduction portion 8 through which a plurality of nozzles 4 for discharging liquid pass.

Then, the liquid is introduced from the common liquid chamber 10 of the frame member 20 into the liquid introduction portion 8 through the opening 9 formed in the diaphragm member 3, and the liquid is introduced from the liquid introduction portion 8 through the fluid resistance portion 7 into the individual liquid chamber 6. Will be supplied. A filter may be provided in the opening 9.

Here, the nozzle plate 1 forms a nozzle hole to be a nozzle 4 by press working on a SUS substrate which is a nozzle base material. A liquid-repellent film is provided on the discharge side surface of the nozzle plate 1.

The flow path plate 2 is composed of a plurality of plate-shaped members 2A, 2B, and 2C stacked in the thickness direction (here, three plates).

The diaphragm member 3 forms the wall surface of the individual liquid chamber 6 of the flow path plate 2 and has a two-layer structure of a first layer 3A and a second layer 3B (one layer or three or more layers may be used). Then, a deformable vibration region (diaphragm) 30 is formed in a portion corresponding to the individual liquid chamber 6 in the first layer 3A on the flow path plate 2 side.

The diaphragm member 3 is formed of a nickel (Ni) metal plate, and is manufactured by an electroforming method (electroforming). Not limited to this, other metal members and resin-metal multi-layer members can be used.

A piezoelectric actuator 11 including an electromechanical conversion element as a driving means (actuator means, pressure generating means) for deforming the vibrating region 30 of the diaphragm member 3 on the side opposite to the individual liquid chamber 6 of the diaphragm member 3. Is placed.

The piezoelectric actuator 11 has a laminated piezoelectric member 12 bonded on the base member 13 with an adhesive, and the piezoelectric member 12 is grooved by half-cut dicing to form a required number of columnar piezoelectric elements (piezoelectric columns) 12A. 12B is formed in a comb-teeth shape at predetermined intervals.

The piezoelectric elements 12A and 12B of the piezoelectric member 12 are the same, but are a piezoelectric element 12A that is driven by giving a drive waveform and a piezoelectric element 12B that is used as a mere column without giving a drive waveform.

Then, the piezoelectric element 12A is joined to the convex portion 30a, which is an island-shaped thick portion formed in the vibration region 30 of the diaphragm member 3. Further, the piezoelectric element 12B is joined to the convex portion 30b which is a thick portion of the diaphragm member 3.

The piezoelectric member 12 is formed by alternately laminating a piezoelectric layer and an internal electrode, and the internal electrodes are each drawn out to the end face to provide an external electrode, and it is possible to give a drive signal to the external electrode of the piezoelectric element 12A. An FPC 15 as a flexible wiring member having flexibility is connected.

The frame member 20 is formed by injection molding with, for example, an epoxy resin or polyphenylene sulfide which is a thermoplastic resin, and a common liquid chamber 10 in which a liquid is supplied from a head tank or a liquid cartridge via a supply port 19 is formed. ing.

In this liquid discharge head, for example, by lowering the voltage applied to the piezoelectric element 12A from the reference potential, the piezoelectric element 12A contracts, the vibration region 30 of the vibrating plate member 3 is pulled out of the plane, and the volume of the individual liquid chamber 6 is reached. As the liquid expands, the liquid flows into the individual liquid chamber 6.

After that, the voltage applied to the piezoelectric element 12A is increased to extend the piezoelectric element 12A in the stacking direction, the vibration region 30 of the diaphragm member 3 is deformed in the nozzle 4 direction, and the volume of the individual liquid chamber 6 is contracted. As a result, the liquid in the individual liquid chamber 6 is pressurized, and the liquid is discharged (sprayed) from the nozzle 4.

Then, by returning the voltage applied to the piezoelectric element 12A to the reference potential, the vibration region 30 of the vibrating plate member 3 is restored to the initial position, the individual liquid chamber 6 expands, and a negative pressure is generated. The liquid is filled from the liquid chamber 10 into the individual liquid chamber 6. Therefore, after the vibration of the meniscus surface of the nozzle 4 is attenuated and stabilized, the operation for the next ejection is started.

The driving method of this head is not limited to the above example (pull-pushing), and pulling or pushing may be performed depending on the driving waveform.

Next, the details of the flow path plate in this embodiment will be described with reference to FIGS. 4 to 6. FIG. 4 is a plan explanatory view of the plate-shaped members 2B and 2C constituting the same flow path plate as viewed from the plate-shaped member 2B side in a stacked state, and FIG. 5 shows the plate-shaped members 2A and 2B constituting the same flow path plate. It is a plane explanatory view seen from the plate-shaped member 2A side in a stacked state. FIG. 6 is an enlarged plan explanatory view of the flow path portion including the fluid resistance portion.

The flow path plate 2 is a flow path having a width wider than that of the fluid resistance portion 7 in the in-plane direction orthogonal to the direction of the liquid flow in the fluid resistance portion 7 and the downstream side and the upstream side of the fluid resistance portion 7. A certain individual liquid chamber 6 and a liquid introduction portion 8 are formed respectively.

That is, as shown in FIG. 6, the width of the fluid resistance portion 7 in the plate-shaped member 2B is W1, the width of the individual liquid chamber 6 is W2, and the width of the liquid introduction portion 8 is W3 (W3 = W2 may be used). At that time, there is a relationship of W1 <W2 and W1 <W3. However, as will be described later, the plate-shaped member 2C forming a part of the individual liquid chamber 6 and the liquid introduction portion 8, and the plate-shaped member 2A forming a part of the individual liquid chamber 6 and the liquid introduction portion 8 are individual liquids. The width of the portion corresponding to the chamber 6 and the liquid introduction portion 8 is slightly narrower than the widths W2 and W3.

As described above, the flow path plate 2 is configured by laminating three plate-shaped members 2A, 2B, and 2C from the nozzle plate 1 side. In the present embodiment, the plate-shaped member 2B is the "first plate-shaped member", and the plate-shaped members 2A and 2C are both "second plate-shaped members".

The plate-shaped member 2B, which is the first plate-shaped member, has a wide portion 121a having a wide width W2, a wide portion 121b having a wide width W3, and a narrow portion 121c having a narrow width W1 connected to the wide portions 121a and 121b. It has a through hole 121 including.

The wide portion 121a of the through hole 121 of the plate-shaped member 2B becomes a part of the individual liquid chamber 6 which is a flow path on the downstream side of the fluid resistance portion 7, and the wide portion 121b of the through hole 121 is on the upstream side of the fluid resistance portion 7. It becomes a part of the liquid introduction section 8 which is the flow path of the above.

The narrow portion 121c of the through hole 121 of the plate-shaped member 2B is connected to the wide portions 121a and 121b to form the fluid resistance portion 7. The narrow portion 121c of the plate-shaped member 2B has a linear region having a length L0 (a region having a constant width) 127 which is constant at the width W1.

The plate-shaped member 2C, which is the second plate-shaped member, has a through hole 122 and a through hole 123.

The through hole 122 of the plate-shaped member 2C becomes a part of the individual liquid chamber 6 which is a flow path together with the wide portion 121a of the through hole 121 of the plate-shaped member 2B, and the through hole 123 is the wide portion of the through hole 121 of the plate-shaped member 2B. Together with the portion 121b, it becomes a part of the liquid introduction portion 8 which is a flow path. Between the through hole 122 and the through hole 123, there is a partition wall portion 125 having a length L1 (L1 ≦ L0) in the fluid resistance portion 7 in the flow direction of the liquid.

The plate-shaped member 2A, which is the second plate-shaped member, has a through hole 124 which is a part of the individual liquid chamber 6 which is a flow path together with the wide portion 121a of the through hole 121 of the plate-shaped member 2B.

In FIGS. 4 to 6, the widths of the through holes 122 and 123 of the plate-shaped member 2C and the through holes 124 of the plate-shaped member 2A are the widths W2 of the wide portions 121a and 121b of the through holes 121 of the plate-shaped member 2B. Although shown in an example narrower than W3, the width may be the same as the widths W2 and W3, or may be wider than the widths W2 and W3.

Further, the end portions where the narrow portion 121c of the through hole 121 of the plate-shaped member 2B is connected to the wide portions 121a and 121b are the outlet portion 7a and the inlet portion 7b of the fluid resistance portion 7. The wall surfaces of the corner portions 121d and 121e at the end portions have a curved surface shape (R shape) in the in-plane direction. The corner portions 121d and 121e of the end portion may have an inclined shape instead of the curved surface shape.

Here, the through hole 122 of the plate-shaped member 2C is formed in the corner portion 121d of the outlet portion 7a of the fluid resistance portion 7, which is an end portion connected to the wide portion 121a of the narrow portion 121c of the through hole 121 of the plate-shaped member 2B. Facing each other. Further, the through hole 123 of the plate-shaped member 2C faces the corner portion 121e of the inlet portion 7b of the fluid resistance portion 7, which is an end portion connected to the wide portion 121b of the narrow portion 121c of the through hole 121 of the plate-shaped member 2B. is doing.

At this time, the upstream end 122a of the through hole 122 of the plate-shaped member 2C in the direction of the liquid flow faces the region 127 where the width of the narrow portion 121c of the through hole 121 of the plate-shaped member 2B is constant. .. Similarly, the downstream end 123a of the through hole 123 of the plate-shaped member 2C in the direction of the liquid flow faces the region 127 where the width of the narrow portion 121c of the through hole 121 of the plate-shaped member 2B is constant. ..

Therefore, in this case, the entire partition wall portion 125 between the through hole 122 and the through hole 123 of the plate-shaped member 2C faces the region 127 where the width of the narrow portion 121c of the through hole 121 of the plate-shaped member 2B is constant. Will be placed.

At this time, the position of the upstream end 124a of the through hole 124 of the plate-shaped member 2A is the same as the position of the upstream end 122a of the through hole 122 of the plate-shaped member 2C, or is located on the downstream side.

With this configuration, the fluid resistance of the fluid resistance portion 7 can be defined by the length L1 of the partition wall portion 125 between the through hole 122 and the through hole 123 of the plate-shaped member 2C. Variations in fluid resistance are reduced.

In this case, since the length of the narrow portion 121c to be the fluid resistance portion 7 is defined by the end portion 122a of the through hole 122 forming the individual liquid chamber 6, the length and the end shape of the narrow portion 121c vary. Even if there is, there is no variation in fluid resistance.

Next, the present embodiment will be described more specifically.

SUS material is used for the plate-shaped members 2A to 2C constituting the flow path plate 2, and through holes 121 to 124 are formed by etching.

When a through hole is formed by etching, the corner portion is easily corroded. Therefore, the corner portions 121d and 121e having a curved surface shape (R shape) of R5 to 100 μm are formed at the outlet portion 7a and the inlet portion 7b of the fluid resistance portion 7. It is formed.

By forming the inlet portion 7b and the outlet portion 7a of the fluid resistance portion 7 in a curved shape in this way, the uniformity of the flow velocity in the vicinity of the inlet and the outlet of the fluid resistance portion 7 is improved, and the liquid is less likely to stay. The retention of bubbles can be suppressed. As a result, stable discharge can be performed.

In addition, since the flatness of the plate-shaped members after processing is higher in the etching process than in the press process, the stacking accuracy between the plate-shaped members is high when a plurality of plate-shaped members are stacked to form a flow path. , The dimensional accuracy of the flow path can be improved, and the variation in the discharge speed and the discharge amount can be reduced.

Further, regarding the positional relationship between the through holes 122 and 123 of the plate-shaped member 2C and the narrow portion 121c of the through holes 121 of the plate-shaped member 2B, as shown in FIG. 6, one ends 122a and 123a of the through holes 122 and 123 Is arranged so as not to face the corners 121d and 121e of the through hole 121 of the plate-shaped member 2B.

In this case, if the lengths L2 and L3 in FIG. 6, which are the amount of overlap between the through holes 122 and 123 and the narrow portion 121c, become large, the head becomes larger, so the lengths L2 and L3 are set to 200 μm or less.

Here, the relationship between the fluid resistance R and the length L1 can be expressed by the following equation (L1 is defined as l in the following equation). The length of the fluid resistance portion is obtained by setting the liquid viscosity, the thickness of the flow path plate, and the target fluid resistance value.

However, R: fluid resistance [Pa · s / m ³ ], Cj: shape resistance (standardized fluid resistance in a fluid having a viscosity 1), μ: liquid viscosity [Pa · s], a: plate-shaped member 2B. Narrow portion 121c (fluid resistance portion 7) width / 2 [m], b: thickness of plate-shaped member 2B (thickness of fluid resistance portion 7) / 2 [m], l: narrow portion of plate-shaped member 2B It is the length (length of the fluid resistance portion) [m] of the region where the two through holes 122 and 123 of the plate-shaped member 2C in 121c do not face each other.

Therefore, the length l can be obtained by substituting R, a, b, and μ into the above equation. For example, the viscosity of the liquid used is 0.004 to 0.008 Pa · s, the thickness of the plate-shaped members 2A, 2B and 2C is 30 to 50 μm, and the width of the narrow portion 121c which is the fluid resistance portion 7 of the plate-shaped member 2B. When is 30 to 100 μm, the length (length of the partition wall portion 125) L1 of the narrow portion 121c of the plate-shaped member 2B in which the two through holes 122 and 123 of the plate-shaped member 2C do not face each other is as follows. The fluid resistance calculated by the formula is set to 30 to 9000 μm so as to be ^{5 to 50 × 10 12} [Pa · s / m ^3].

Further, as can be seen from FIG. 6, it is also possible to calculate L2 and L3 by subtracting L1 from the total length of the flow path resistance portion 7.

The smaller the ratio of the cross-sectional area of the region 127 where the width of the fluid resistance portion 7 is constant to the cross-sectional area of the outlet portion 7a and the inlet portion 7b of the fluid resistance portion 7 (the cross-sectional area of the cross section orthogonal to the flow of the liquid). The fluid resistance depends on the cross-sectional area and length of the region 127 in which the width of the fluid resistance portion 7 is constant.

In the present embodiment, the two through holes 122 and 123 of the plate-shaped member 2C are opposed to the outlet portion 7a of the fluid resistance portion 7 of the plate-shaped member 2B and the corner portions 121d and 121e of the inlet portion 7b, so that the fluid resistance is formed. The ratio of the cross-sectional area of the region 127 having a constant width of the fluid resistance portion 7 to the cross-sectional area in the vicinity of the outlet portion 7a and the inlet portion 7b of the portion 7 becomes small.

As a result, the fluid resistance depends on the cross-sectional area and length of the region 127 in which the width of the fluid resistance portion 7 is constant, and the corner portions 121d and 121e of the outlet portion 7a and the inlet portion 7b of the fluid resistance portion 7 have a rounded shape. It will not be affected by variations.

Since the cross-sectional area and length of the region 127 having a constant width of the fluid resistance portion 7 have high dimensional accuracy, the variation in the fluid resistance can be reduced and the variation in the discharge characteristics can be reduced.

Further, in the present embodiment, the widths of the two through holes 122 and 123 of the plate-shaped member 2C are larger than the width of the narrow portion 121c of the plate-shaped member 2B.

In this case, the ratio of the cross-sectional area of the region 127 having a constant width of the fluid resistance portion 7 to the cross-sectional area of the outlet portion 7a and the inlet portion 7b of the fluid resistance portion 7 becomes smaller, so that the fluid resistance becomes more fluid resistance. The width of the portion 7 depends on the cross-sectional area and the length of the constant region 127.

As a result, the fluid resistance is less affected by the variation in the radius shape of the outlet portion 7a of the fluid resistance portion 7, the corner portions 121d, and 121e of the inlet portion 7b, and the variation in the fluid resistance can be further reduced.

Next, the liquid discharge head according to the second embodiment of the present invention will be described with reference to FIGS. 7 and 8. FIG. 7 is a plan explanatory view of a flow path portion including a fluid resistance portion in the same embodiment, and FIG. 8 is a cross-sectional explanatory view in a direction orthogonal to the nozzle arrangement direction (liquid chamber longitudinal direction) similar to FIG.

In the present embodiment, only one end 123a of one of the two through holes 122 and 123 of the plate-shaped member 2C (here, the through hole 123) is opposed to the region 127 where the width of the narrow portion 121c is constant. It is arranged.

In this case, the variation in fluid resistance is larger than that in the above-described configuration, but the width of the narrow portion 121c is constant in each of the two through holes 122 and 123 of the plate-shaped member 2C, 122a and 123a. The variation in fluid resistance can be reduced as compared with the case where it does not face 127.

Further, in the present embodiment, one end 124a of the through hole 124 of the plate-shaped member 2A and one end 122a of the through hole 122 of the plate-shaped member 2C (that is, one end on the individual liquid chamber 6 side) are formed in the narrow portion 121c. It does not face a region 127 with a constant width. As compared with the first embodiment, since the corner portion 121d does not protrude from the wall surface in the individual liquid chamber 6, the reflection of the vibration of the liquid in the individual liquid chamber 6 is suppressed.

Next, the liquid discharge head according to the third embodiment of the present invention will be described with reference to FIGS. 9 and 10. FIG. 9 is a plan explanatory view of a flow path portion including a fluid resistance portion in the same embodiment, and FIG. 10 is a cross-sectional explanatory view in a direction orthogonal to the nozzle arrangement direction (liquid chamber longitudinal direction) similar to FIG.

In the present embodiment, one end 124a of the through hole 124 of the plate-shaped member 2A is opposed to a region 127 having a constant width of the narrow portion 121c, and one end 123a of the through hole 123 of the plate-shaped member 2C is the width of the narrow portion 121c. Is opposed to a certain area 127.

Also in this case, similarly to the first embodiment, the fluid resistance can be defined by using the inside of the region 127 where the width of the fluid resistance portion 7 (narrow portion 121c) is constant, and the variation of the fluid resistance can be varied. Can be reduced.

Further, in the present embodiment, one end 122a of the through hole 122 of the plate-shaped member 2C does not face the region 127 where the width of the narrow portion 121c is constant. Therefore, as compared with the first embodiment, one end 122a where air bubbles are likely to accumulate can be brought closer to the nozzle hole 4 side, and in addition to the above-mentioned effect, the air bubble discharge property at the time of head cleaning is also improved.

Further, by moving one end 122a away from the fluid resistance portion 7, the stagnation point is kept away from the vicinity of the fluid resistance portion 7, and there is also an effect of reducing the turbulence of the flow in the vicinity of the fluid resistance portion 7.

Next, the liquid discharge head according to the fourth embodiment of the present invention will be described with reference to FIGS. 11 to 13. 11 is an external perspective explanatory view of the liquid discharge head, FIG. 12 is a cross-sectional explanatory view along the longitudinal direction of the liquid chamber, and FIG. 13 is a plan view of the circulation flow path portion. The parts corresponding to the first embodiment are designated by the same reference numerals, and the description thereof will be omitted or simplified.

In this liquid discharge head, a nozzle plate 1, a flow path plate 2, and a diaphragm member 3 as a wall surface member are laminated and joined. A piezoelectric actuator 11 that displaces the diaphragm 3, a frame member 20 as a common liquid chamber member, and a cover 21 are provided.

Then, as shown in FIG. 12, the flow path plate 2 has a circulation flow path that passes through the nozzle plate 1 side, the nozzle passage 5 passing through the nozzle 4 and the individual liquid chamber 6, and the circulation flow path side fluid resistance portion 42. 43 is formed. The circulation flow path 43 leads to the circulation common liquid chamber 45 formed in the frame member 20 through the passage 44 formed in the direction perpendicular to the plane.

As shown in FIG. 11, the frame member 20 is provided with a supply port 23 leading to the common liquid chamber 10 and a circulation port (discharge port) 46 leading to the circulation common liquid chamber 45, respectively.

Here, the flow path plate 2 is composed of five stacked plate-shaped members 2D, 2E, 2F, 2B, and 2C from the nozzle plate 1 side. In the present embodiment, the plate-shaped members 2B and 2D are "first plate-shaped members", and the plate-shaped members 2C and 2E are "second plate-shaped members".

As shown in FIG. 13A, the plate-shaped member 2D has a narrow portion 141c that becomes a fluid resistance portion 42, a wide portion 141b that becomes a part of a nozzle passage 5 on the upstream side of the fluid resistance portion 42, and a fluid. It has a through hole 141 having a wide portion 141a that is a part of the circulation flow path 43 on the downstream side of the resistance portion 42.

As shown in FIG. 13B, the plate-shaped member 2E includes a through hole 142 that becomes a part of the nozzle passage 5 together with a wide portion 141b of the through hole 141 of the plate-shaped member 2D, and a through hole of the plate-shaped member 2D. It has a through hole 143 that becomes a part of the circulation flow path 43 together with the wide portion 141a of 141.

Then, as in the first embodiment, the partition wall portion 145 between the through hole 142 and the through hole 143 of the plate-shaped member 2E is opposed to the narrow portion 141c of the through hole 141 of the plate-shaped member 2D. ..

In this case, as in the first embodiment, the through hole 142 of the plate-shaped member 2E is a fluid resistance portion 42 which is an end portion where the narrow portion 141c of the through hole 141 of the plate-shaped member 2D is connected to the wide portion 141a. Facing the exit part of. Further, the through hole 143 of the plate-shaped member 2E faces the inlet portion of the fluid resistance portion 42, which is an end portion where the narrow portion 141c of the through hole 141 of the plate-shaped member 2D is connected to the wide portion 141b.

In this case, one end of the through holes 142 and 143 of the plate-shaped member 2E in the direction of liquid flow faces a region where the width of the narrow portion 141c of the through holes 141 of the plate-shaped member 2D is constant. Therefore, the entire partition wall portion 145 faces the region where the width of the narrow portion 141c is constant.

Thereby, the fluid resistance of the fluid resistance portion 42 can be defined by the length of the partition wall portion 145, and the variation in the fluid resistance can be reduced, which is the same as described in the first embodiment.

As in the second embodiment, the width of the narrow portion 141c of the through hole 141 of the plate-shaped member 2D is such that one end of the through hole 142 or 143 of the plate-shaped member 2E in the liquid flow direction is one end. It can also be configured to face a certain area.

Further, the configuration of the fluid resistance unit 7 that supplies the liquid to the individual liquid chamber 6 side is the same as that of the first embodiment. However, unlike the plate-shaped member 2A of the first embodiment, the plate-shaped member 2F is not provided with a through hole forming a flow path on the downstream side and the upstream side of the fluid resistance portion 7.

In each of the above embodiments, the flow path on the upstream side of the fluid resistance portion on the side of supplying the liquid to the individual liquid chamber is described as an example of the liquid introduction portion leading to the common liquid chamber, but the common liquid chamber is described. It can also be. In this case, a fluid resistance portion is formed on the flow path plate, and the common liquid chamber is formed on a common liquid chamber member different from the flow path plate, that is, the width is wider than the fluid resistance portion only on the downstream side of the fluid resistance portion. It is also possible to form a flow path.

Further, in each of the above embodiments, the example of having the fluid resistance portion and the through hole serving as the flow path is described, but when the surface of the plate-shaped member in the thickness direction may be closed, the fluid resistance portion, The present invention can be similarly applied as a configuration in which a groove serving as a flow path is provided.

Next, an example of the device for discharging the liquid according to the present invention will be described with reference to FIGS. 14 and 15. FIG. 14 is an explanatory plan view of a main part of the device, and FIG. 15 is an explanatory view of a side surface of the main part of the device.

This device is a serial type device, and the carriage 403 is reciprocated in the main scanning direction by the main scanning moving mechanism 493. The main scanning movement mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408, and the like. The guide member 401 is bridged over the left and right side plates 491A and 491B to movably hold the carriage 403. Then, the carriage 403 is reciprocated in the main scanning direction by the main scanning motor 405 via the timing belt 408 bridged between the drive pulley 406 and the driven pulley 407.

The carriage 403 is equipped with a liquid discharge unit 440 in which the liquid discharge head 404 and the head tank 441 according to the present invention are integrated. The liquid discharge head 404 of the liquid discharge unit 440 discharges, for example, liquids of each color of yellow (Y), cyan (C), magenta (M), and black (K). Further, the liquid discharge head 404 is mounted by arranging a nozzle row composed of a plurality of nozzles in a sub-scanning direction orthogonal to the main scanning direction and facing the discharge direction downward.

The liquid stored in the liquid cartridge 450 is supplied to the head tank 441 by the supply mechanism 494 for supplying the liquid stored outside the liquid discharge head 404 to the liquid discharge head 404.

The supply mechanism 494 includes a cartridge holder 451 which is a filling part for mounting the liquid cartridge 450, a tube 456, a liquid feeding unit 452 including a liquid feeding pump, and the like. The liquid cartridge 450 is detachably attached to the cartridge holder 451. Liquid is delivered from the liquid cartridge 450 to the head tank 441 by the liquid feeding unit 452 via the tube 456.

This device includes a transport mechanism 495 for transporting the paper 410. The transport mechanism 495 includes a transport belt 412, which is a transport means, and a sub-scanning motor 416 for driving the transport belt 412.

The transport belt 412 attracts the paper 410 and transports it at a position facing the liquid discharge head 404. The transport belt 412 is an endless belt, and is hung between the transport roller 413 and the tension roller 414. Adsorption can be performed by electrostatic adsorption, air suction, or the like.

Then, the transport belt 412 orbits in the sub-scanning direction by rotationally driving the transport roller 413 via the timing belt 417 and the timing pulley 418 by the sub-scanning motor 416.

Further, on one side of the carriage 403 in the main scanning direction, a maintenance / recovery mechanism 420 for maintaining / recovering the liquid discharge head 404 is arranged on the side of the transport belt 412.

The maintenance / recovery mechanism 420 includes, for example, a cap member 421 that caps the nozzle surface (the surface on which the nozzle is formed) of the liquid discharge head 404, a wiper member 422 that wipes the nozzle surface, and the like.

The main scanning movement mechanism 493, the supply mechanism 494, the maintenance / recovery mechanism 420, and the transport mechanism 495 are attached to a housing including the side plates 491A and 491B and the back plate 491C.

In this apparatus configured in this way, the paper 410 is fed onto the transport belt 412 and sucked, and the paper 410 is conveyed in the sub-scanning direction by the circumferential movement of the conveyor belt 412.

Therefore, by driving the liquid ejection head 404 in response to the image signal while moving the carriage 403 in the main scanning direction, the liquid is ejected onto the stopped paper 410 to form an image.

As described above, since this device includes the liquid discharge head according to the present invention, it is possible to stably form a high-quality image.

Next, another example of the liquid discharge unit according to the present invention will be described with reference to FIG. FIG. 16 is an explanatory plan view of a main part of the unit.

This liquid discharge unit includes a housing portion composed of side plates 491A, 491B and a back plate 491C, a main scanning movement mechanism 493, a carriage 403, and a liquid among the members constituting the device for discharging the liquid. It is composed of a discharge head 404.

It should be noted that a liquid discharge unit may be configured in which at least one of the above-mentioned maintenance / recovery mechanism 420 and the supply mechanism 494 is further attached to, for example, the side plate 491B of the liquid discharge unit.

Next, still another example of the liquid discharge unit according to the present invention will be described with reference to FIG. FIG. 17 is a front explanatory view of the unit.

This liquid discharge unit includes a liquid discharge head 404 to which the flow path component 444 is attached, and a tube 456 connected to the flow path component 444.

The flow path component 444 is arranged inside the cover 442. A head tank 441 may be included instead of the flow path component 444. Further, a connector 443 that electrically connects to the liquid discharge head 404 is provided on the upper part of the flow path component 444.

In the present application, the "device for discharging a liquid" is a device provided with a liquid discharge head or a liquid discharge unit and driving the liquid discharge head to discharge the liquid. The device for discharging a liquid includes not only a device capable of discharging a liquid to a device to which the liquid can adhere, but also a device for discharging the liquid into the air or into the liquid.

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

For example, as a "device that ejects a liquid", an image forming device that is a device that ejects ink to form an image on paper, and a three-dimensional object (three-dimensional object) are formed in layers in order to form a three-dimensional object. There is a three-dimensional modeling device (three-dimensional modeling device) that discharges the modeling liquid into the powder layer.

Further, the "device for discharging a liquid" is not limited to a device in which a significant image such as characters and figures is visualized by the discharged liquid. For example, those that form patterns that have no meaning in themselves and those that form a three-dimensional image are also included.

The above-mentioned "thing to which a liquid can adhere" means a material to which a liquid can adhere at least temporarily, such as a material to which the liquid adheres and adheres, and a material to which the liquid adheres and permeates. Specific examples include paper, recording paper, recording paper, film, recorded media such as cloth, electronic substrates, electronic components such as piezoelectric elements, powder layers (powder layers), organ models, and media such as inspection cells. Yes, and includes everything to which the liquid adheres, unless otherwise specified.

The material of the above-mentioned "material to which a liquid can adhere" may be paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics or the like as long as the liquid can adhere even temporarily.

The "liquid" also includes inks, treatment liquids, DNA samples, resists, pattern materials, binders, modeling liquids, or solutions and dispersions containing amino acids, proteins, and calcium.

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

In addition, as a "device for ejecting liquid", a treatment liquid coating device for ejecting a treatment liquid to the paper in order to apply the treatment liquid to the surface of the paper for the purpose of modifying the surface of the paper, raw materials. There is an injection granulation device that granulates fine particles of raw materials by injecting a composition liquid dispersed in a solution through a nozzle.

The "liquid discharge unit" is a liquid discharge head integrated with functional parts and a mechanism, and is a collection of parts related to liquid discharge. For example, the "liquid discharge unit" includes a head tank, a carriage, a supply mechanism, a maintenance / recovery mechanism, a main scanning movement mechanism in which at least one of the configurations is combined with a liquid discharge head, and the like.

Here, the term "integration" means, for example, a liquid discharge head and a functional component, a mechanism in which the mechanism is fixed to each other by fastening, bonding, engagement, etc., or one in which one is movably held with respect to the other. include. Further, the liquid discharge head, the functional component, and the mechanism may be configured to be detachable from each other.

For example, as a liquid discharge unit, there is a liquid discharge head and a head tank integrated, such as the liquid discharge unit 440 shown in FIG. In some cases, the liquid discharge head and the head tank are integrated by being connected to each other by a tube or the like. Here, a unit including a filter can be added between the head tank of these liquid discharge units and the liquid discharge head.

Further, as a liquid discharge unit, there is a unit in which a liquid discharge head and a carriage are integrated.

Further, there is a liquid discharge unit in which the liquid discharge head and the scanning movement mechanism are integrated by holding the liquid discharge head movably by a guide member constituting a part of the scanning movement mechanism. Further, as shown in FIG. 16, there is a liquid discharge unit in which a liquid discharge head, a carriage, and a main scanning movement mechanism are integrated.

Further, as a liquid discharge unit, there is a carriage to which a liquid discharge head is attached, in which a cap member which is a part of the maintenance / recovery mechanism is fixed, and the liquid discharge head, the carriage, and the maintenance / recovery mechanism are integrated. ..

Further, as a liquid discharge unit, as shown in FIG. 17, a tube is connected to a head tank or a liquid discharge head to which a flow path component is attached, and the liquid discharge head and a supply mechanism are integrated. ..

The main scanning movement mechanism shall include a single guide member. Further, the supply mechanism includes a single tube and a single loading unit.

Further, the pressure generating means used for the "liquid discharge head" is not limited. For example, in addition to the piezoelectric actuator as described in the above embodiment, a thermal actuator using an electric heat conversion element such as a heat generating resistor, an electrostatic actuator composed of a diaphragm and a counter electrode, or the like may be used.

Further, in the terms of the present application, image formation, recording, printing, printing, printing, modeling, etc. are all synonymous.

1 Nozzle plate 2 Flow plate 2A, 2C, 2E Plate-shaped member (second plate-shaped member)
2B, 2D plate-shaped member (first plate-shaped member)
3 Vibrating plate member 4 Nozzle 5 Nozzle passage 6 Individual liquid chamber 7 Fluid resistance part 8 Liquid introduction part 10 Common liquid chamber 12 Hydraulic member 20 Frame member 42 Fluid resistance part 43 Circulation flow path 45 Circulation common liquid chamber 121-124 Through hole 125 Bulk partition 121a, 121b Wide part 121c Narrow part 141-143 Through hole 141a, 121b Wide part 141c Narrow part 403 Carriage 404 Liquid discharge head 440 Liquid discharge unit

Claims (9)

A flow path having a width in the in-plane direction orthogonal to the direction of the liquid flow is formed in at least one of the fluid resistance portion and the downstream side and the upstream side of the fluid resistance portion. Equipped with a flow board
The flow path plate includes at least a stacked first plate-shaped member and a second plate-shaped member.
The first plate-shaped member is a through hole or groove including a wide portion that is a part of the flow path and a narrow portion that is connected to the wide portion and serves as a fluid resistance portion. Have,
The second plate-shaped member has a through hole or a groove portion that becomes a part of the flow path together with a wide portion of the through hole of the first plate-shaped member.
On the upstream side of the fluid resistance portion, the through hole or groove portion of the second plate-shaped member faces the narrow portion of the through hole of the first plate-shaped member.
A liquid discharge head characterized in that, on the downstream side of the fluid resistance portion, the through hole or groove portion of the second plate-shaped member does not face the narrow portion of the through hole of the first plate-shaped member. .. The liquid discharge head according to claim 1, wherein the narrow portion of the through hole or the groove portion of the first plate-shaped member has a region where the width is constant. Wall surface of the through hole or the width end portions that connected to the wide portion of the narrow portion of the groove of the first plate member, characterized in that it has a curved shape or slope shape in plane direction The liquid discharge head according to claim 1 or 2. The through hole or groove portion of the first plate-shaped member has the wide portion on the upstream side and the downstream side of the narrow portion, respectively.
The narrow portion of the through hole or the groove portion of the first plate-shaped member has a region where the width is constant.
The second plate-shaped member has two through-holes or grooves that pass through the two wide portions of the first plate-shaped member and become a part of the flow path.
The entire partition wall portion between the two through holes or grooves of the second plate-shaped member faces the region where the width of the through holes or grooves of the first plate-shaped member is constant. The liquid discharge head according to claim 1. The flow path on the downstream side of the fluid resistance portion is an individual liquid chamber through which a nozzle for discharging liquid passes.
Claims 1 to 4 are characterized in that the flow path on the upstream side of the fluid resistance portion is a common liquid chamber for supplying a liquid to the individual liquid chambers or a liquid introduction portion for introducing the liquid from the common liquid chamber. The liquid discharge head according to any one of. The flow path on the upstream side of the fluid resistance portion is a nozzle passage through which the nozzle for discharging the liquid and the individual liquid chamber through which the nozzle communicates pass.
The liquid discharge head according to any one of claims 1 to 4, wherein the flow path on the downstream side of the fluid resistance portion is the circulation flow path of the liquid. A liquid discharge unit comprising the liquid discharge head according to any one of claims 1 to 6. A head tank that stores the liquid to be supplied to the liquid discharge head, a carriage on which the liquid discharge head is mounted, a supply mechanism that supplies the liquid to the liquid discharge head, a maintenance / recovery mechanism that maintains and recovers the liquid discharge head, and the liquid. The liquid discharge unit according to claim 7, wherein at least one of the main scanning moving mechanisms for moving the discharge head in the main scanning direction is integrated with the liquid discharge head. A device for discharging a liquid, comprising the liquid discharge head according to any one of claims 1 to 6 or the liquid discharge unit according to claim 7 or 8.

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